Net Station Acquisition - Center for Brain, Biology and Behavior

Net Station Acquisition - Center for Brain, Biology and Behavior
Net Station Acquisition Technical Manual
Electrical Geodesics, Inc.
Net Station
Acquisition
Technical Manual
Electrical Geodesics, Inc.
Riverfront Research Park
1600 Millrace Drive, Suite 307
Eugene, OR 97403
info@egi.com
www.egi.com
Net Station
Acquisition
Technical Manual
S-MAN-200-ACQR-001
September 30, 2003
Electrical Geodesics makes no warranty or representation, either express or implied, with
respect to this manual, its quality, accuracy, merchantability, or fitness for a particular
purpose. In no event will Electrical Geodesics be liable for direct, indirect, special, incidental,
or consequential damages resulting from any defect or inaccuracy in this manual, even if
advised of the possibility of such damage.
Copyright 2003 by Electrical Geodesics, Inc; copyright 2001, as individual chapters in the
EGI System 200 Technical Manual, by Electrical Geodesics, Inc.
All rights reserved.
CONTENTS
List of Figures ix
List of Tables xv
Preface xvii
About This Manual . . . xviii
Troubleshooting, Support, and Repair . . . xx
chapter 1
Acquisition Overview 21
Intended Use . . . 21
Net Station Acquisition Overview . . . 21
chapter 2
Introducing Net Station 27
Learning to Use Net Station . . . 28
Net Station Distribution . . . 28
Net Station Under OS X . . . 29
Mac Desktop Items . . . 30
Root Directory . . . 30
Net Station Folder . . . 31
Documents Folder . . . 33
Workbench and Devices . . . 35
Acquisition Setup . . . 37
Workbench Off and On . . . 38
Recording On and Off . . . 38
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Contents
chapter 3
The Workbench 39
Menus and Acquisition Status . . . 39
Devices in General . . . 41
Device Buttons . . . 43
Device Panels . . . 43
Devices Palette . . . 44
Placing and Connecting Devices . . . 45
Core Devices . . . 46
Device Panels . . . 49
Info Panels . . . 49
Control Panels . . . 50
Display Panels . . . 72
Menus . . . 83
Default Acquisition Setups . . . 94
Creating New Acquisition Setups . . . 100
chapter 4
Dense Waveform Display 105
Introduction . . . 105
chapter 5
Sessions and Session Templates 115
Net Station Session . . . 115
Session Template Components . . . 117
How to Create a Session Template . . . 119
How to Use A Session Template . . . 123
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Contents
Appendix A
Updating EGI Licenses 129
Tips on Updating EGI Licenses . . . 130
Opening the Updater Application . . . 131
Generating the Update File . . . 132
Applying an Updated File . . . 133
Questions . . . 134
Appendix B
Software Technical Support 135
Appendix C
Panels 137
Appendix D
Montages 139
Glossary 151
Index 161
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Contents
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LIST OF FIGURES
chapter 1
chapter 2
Acquisition Overview
1-1
Core components 21
1-2
Subject wearing an example sensor array 22
1-3
Net Station Acquisition functional block diagram 23
1-4
Sensor array, interface cable, amplifier 23
1-5
Amplifier–to-DAC connection diagram 24
1-6
Net Station displays and records EEG waveforms 24
1-7
Onscreen waveforms are composed of pixels 25
1-8
Net Station data files 26
Introducing Net Station
2-1
Desktop and Dock icons of the Distribution 30
2-2
Root directory structure of data-acquisition hard drive 30
2-3
Inside the Net Station folder 31
2-4
Contents of Net Station User Data folder 33
2-5
Example of deploying a control panel 36
2-6
The Workbench 36
2-7
Workbench devices 37
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List of Figures
chapter 3
x
The Workbench
3-1
Menus and Acquisition status panel 39
3-2
Acquisition status panel with Workbench on 40
3-3
Dense Waveform Display device with parts labeled 42
3-4
Devices palette 44
3-5
Cabling two devices together 46
3-6
Three core devices in a Workbench configuration 47
3-7
Example Dense Waveform Display 48
3-8
Info panel 49
3-9
Digital Filter Controls 50
3-10
Effect of toggling the Lowpass button 51
3-11
Appearance of buttons when filter is on 51
3-12
Recording of IIR-filtered data is inadvisable 52
3-13
Montage controls panel (Workbench on) 53
3-14
Waveform Recorder Controls (Workbench off) 54
3-15
Waveform Recorder Controls detail (Session) 54
3-16
Click the Record button 55
3-17
Session Info and Close Session buttons 56
3-18
Expanded Waveform Recorder Controls panel 57
3-19
Using the Timed Record feature 58
3-20
Net Amps USB Control panels (Panels menu) 58
3-21
Net Amps Controls (default settings) 59
3-22
Calibration progress bars 60
3-23
Advanced Net Amps Controls panel (default settings) 62
3-24
DIN port pin numbers map to bits 63
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List of Figures
3-25
Connect STIM to deliver digital input data to downstream device 63
3-26
Digital Input Controls panel, with Source tabpanel selected 65
3-27
Tracks and Events tabpanels 66
3-28
Advanced Event Setup 67
3-29
Channel 1 after being selected 67
3-30
Event Identifiers subpanel 68
3-31
Editing code and label of a channel 68
3-32
After you have clicked OK, the code and label are set 68
3-33
Anatomy of DIN event 69
3-34
Keys and counters 69
3-35
Edge vs. pulse 70
3-36
Track pop-up menu 71
3-37
Presets subpanel 71
3-38
Example Setup Inputs panel 71
3-39
Digital inputs display 72
3-40
Example Dense Waveform Display panel 73
3-41
Generic Net Amps display panel 74
3-42
History area and insets of the Gains display panel 76
3-43
Noise measurement in a low-noise environment 77
3-44
Noise Distribution histogram 78
3-45
Noise panel insets 78
3-46
Noise panel in a noisier environment 79
3-47
Example Impedance display panel 80
3-48
Example Impedance Measurement window 81
3-49
Impedance Measurement window controls 82
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List of Figures
xii
3-50
Experimental Control Status showing Timeout pop-up menu 83
3-51
Workbench menu bar 84
3-52
Session menu bar 84
3-53
Dense Waveform Display menu bar 84
3-54
File menu 85
3-55
New window showing correspondence to sidebar 85
3-56
Edit menu 86
3-57
Acq menu 87
3-58
Panels menu 88
3-59
Example of reversibly iconizing a panel 88
3-60
Record menu, Workbench, and Session variants 89
3-61
New Recording window 90
3-62
Clicking Record initiates Workbench recording 90
3-63
Big controls and small controls 90
3-64
Display menu 91
3-65
Amplitude menu 92
3-66
Time menu (default settings) 92
3-67
Events menu 93
3-68
Help menu 93
3-69
Device configuration of Primitive Acquisition Setup 94
3-70
Primitive Acquisition Setup 95
3-71
Workbench configuration of Typical Acquisition Setup 96
3-72
Panel deployment of Typical Acquisition Setup 97
3-73
Workbench configuration of Experimental Control Setup 98
3-74
Panel Deployment of Experimental Control Setup 99
3-75
Default Save dialog for saving Acquisition Setups 100
3-76
Recording but not displaying digital inputs 100
3-77
Correct connection of filter device, no events 101
3-78
Example of a cable loop (invalid configuration) 102
3-79
A correct dual-DWD configuration with mark events 102
3-80
Reconfiguring for a simpler configuration 103
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List of Figures
chapter 4
chapter 5
Dense Waveform Display
4-1
Invoking the Dense Waveform Display 105
4-2
Example Dense Waveform Display 106
4-3
Pop-up menus 107
4-4
Pause line 108
4-5
Scale control strip 109
4-6
Time control strip 110
4-7
Events control strip 110
4-8
Tracks area with Events control strip 111
4-9
Waveform Options control strip 113
4-10
Numbered channel tile label example 114
Sessions and Session Templates
5-1
Flowchart for initiating a session 116
5-2
Anatomy of a Session Template 117
5-3
Embedding an Acquisition Setup in a Session Template 118
5-4
Create New Session Template window 120
5-5
Insert Fields window 121
5-6
Create New Field window with Field Type pop-up menu 122
5-7
Example of a completed Session Template 122
5-8
Select Session Template window with Experimental Control Template
selected 123
5-9
Enter Session Information window included with the default templates 124
5-10
Autonaming for default Typical Session Template 125
5-11
Rename Session window 125
5-12
Session information has been entered 126
5-13
During amplifier calibration 126
5-14
Click the Measure Net Impedance buttons 127
5-15
Impedance Measurement window (EGI’s 256-channel Net) 127
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List of Figures
Appendix A
Appendix D
xiv
Updating EGI Licenses
1-1
Overview of the license-updating process 129
1-2
HASP-updating tips 130
1-3
Open the HASP Updater application 131
1-4
Create the HASP Update file, compress it, and email it to EGI 132
1-5
Apply the Updated file from EGI to the corresponding HASP 133
Montages
4-1
10-20 (256-channel Net) 140
4-2
10-20 (128-channel Net) 141
4-3
10-20 (64-channel Net) 141
4-4
Double Banana (256-channel Net) 142
4-5
Double Banana (128-channel Net) 142
4-6
Double Banana (64-channel Net) 143
4-7
Eyes (256-channel Net) 143
4-8
Eyes (126-channel Net) 144
4-9
Eyes (64-channel Net) 144
4-10
Left Mastoid Reference (256-channel Net) 145
4-11
Left Mastoid Reference (128-channel Net) 145
4-12
Left Mastoid Reference (64-channel Net) 146
4-13
Linked Mastoid Reference (256-channel Net) 146
4-14
Linked Mastoid Reference (128-channel Net) 147
4-15
Linked Mastoid Reference (64-channel Net) 147
4-16
Right Mastoid Reference (256-channel Net) 148
4-17
Right Mastoid Reference (128-channel Net) 148
4-18
Right Mastoid Reference (64-channel Net) 149
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LIST OF TABLES
chapter 3
chapter 4
The Workbench
3-1
Workbench rules
3-2
Device class descriptions
3-3
Panel references
3-4
Time modes
3-5
Default channels to tracks assignments
43
57
70
Mark events
111
Panels
C-1
Appendix D
41
Dense Waveform Display
4-1
Appendix C
40
Panel icon reference
137
Montages
D-1
256-channel montages
139
D-2
128-channel montages
139
D-3
64-channel montages
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List of Tables
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PREFACE
Station from Electrical Geodesics, Inc. (EGI) is a complete software package for
N etworking
with electroencephalographic (EEG) and event-related potential (ERP)
data. With Net Station, you can
• acquire EEG, in conjunction with EGI’s Net Amps and dense-array
Geodesic Sensor Nets (GSNs)
The Net Station icon
• perform various operations on your data, primarily for basic ERP derivation
and analysis
• view and navigate EEG and ERP data
The following publications, and other technical documentation, are available as
PDF files at www.egi.com/documentation.html:
• The Net Station Acquisition is the component of Net Station for acquiring EEG,
in conjunction with EGI’s Net Amps and sensor arrays. This manual, the Net
Station Acquisition Technical Manual, provides comprehensive descriptions of
Acquisition features and functions.
• The Net Station Viewer is the component of Net Station for viewing and
navigating EEG and ERP data. The Net Station Viewer Technical Manual
provides comprehensive descriptions of all Viewer features and functions.
• The Net Station Waveform Tools is the component of Net Station for performing
various operations on EEG data, primarily for basic ERP derivation and
analysis. The Net Station Waveform Tools Technical Manual provides
comprehensive descriptions of all Waveform Tools features and functions.
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Preface
• The Net Station Viewer and Waveform Tools Tutorial instructs you in the use
of Net Station Viewer and Waveform Tools by guiding you through the analysis
of a sample data set. It is not intended to be a comprehensive guide to these
components, but it is a good place to start when learning about the software.
• The Net Station File Formats Technical Manual documents the objects
contained in a native Net Station file, the formats of the export files, and other
files associated with Net Station.
These publications contain a good deal of background information on the EEG and
ERP field. However, they are not intended to represent a complete primer in this field.
To get the most out of these books, you should have some background in EEG and
ERP methods.
These manuals assume you are familiar with the Macintosh computer, the platform
for Net Station software.
About This Manual
Features
This manual is supplied as a PDF file and in printed form. The hard-copy version has
been printed from the PDF so the content of both will match. The hard-copy manual
contains grayscale images; the PDF contains color and grayscale images.
Manual Organization
This manual features a table of contents, list of figures, list of tables, and index, which
in the PDF are all hyperlinked to the topics they reference in the manual.
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Preface
The chapters fall into two main categories:
• Introduction: Chapter 1, "Acquisition Overview,” and Chapter 2, "Introducing
Net Station,” provide overview of the acquisition process and the Net Station
application organization.
• Tools: Chapter 3, "The Workbench”; Chapter 4, "Dense Waveform Display”; and
Chapter 5, "Sessions and Session Templates,” describe the three major
Acquisition tools in detail.
A number of appendixes are also include:
•
•
•
•
Appendix A, "Updating EGI Licenses”
Appendix B, "Software Technical Support”
Appendix C, "Panels”
Appendix D, "Montages”
Typography
In general, a minimal amount of special fonts are used in this manual—italics for
definitions or newly introduced terms, and boldface italics for important concepts.
Additional Information
Two different methods are used to convey additional information: notes and cautions.
Note: This indicates information that is helpful in understanding Net Station operations.
Caution!: This denotes important information that, if unheeded, could hinder use
of Net Station.
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Preface
Troubleshooting, Support, and Repair
• For online updates to this book, check EGI’s
Documentation page at www.egi.com/
documentation.html.
• To update your Net Station license, see Appendix A,
"Updating EGI Licenses.”
• For Net Station EEG and ERP software support, see
Appendix B, "Software Technical Support.”
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Net Station Acquisition Technical Manual
The EGI Documentation
page at www.egi.com/
documentation.html
S-MAN-200-ACQR-001 • September 30, 2003
chapter 1
CHAPTER
1
ACQUISITION
OVERVIEW
Net Station Acquisition software is designed for the acquisition of denseE GI’s
array EEG data. This manual, the Net Station Acquisition Technical Manual,
describes the components of Net Station Acquisition and its use.
Intended Use
Net Station is intended for use in clinical and research settings, by trained technicians,
for collecting and analyzing EEG data from adults, children, and infants.
Net Station Acquisition Overview
Your system equipment can be set up in various ways. However, all configurations
share a common set of core components (Figure 1-1), including at least one sensor
array, one amplifier, and a data-acquisition computer (DAC) running EGI’s
Net Station software.
Sensor array
Amplifier
Data-acquisition computer
Net Station is installed and runs
on this computer.
Figure 1-1. Core components
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1: Acquisition Overview
Sensor Array
During EEG recordings, subjects wear a sensor array.
A subject wearing a 64-channel adult-sized EGI
Geodesic Sensor Net is shown as an example in
Figure 1-2.
Amplifier
A sensor array is connected to an amplifier. The
amplifier filters and measures the EEG signals that are
picked up by the sensor array and samples them at
millisecond intervals.
Figure 1-2. Subject wearing
an example sensor array
The digitized samples are transferred to the DAC in real
time.
DAC and Net Station
Packets of data containing digitized EEG samples are sent from the amplifier to the
DAC so that the Net Station software can collect them for display and storage to disk.
In Net Station, you can display EEG data in a variety of ways and record them to
permanent computer files.
Net Station resides on the DAC, where it is capable of continuously collecting densearray EEG data from the amplifier.
Caution!: Verify that the sleep mode for the hard drive is “off.” Otherwise,
Net Station will freeze when the hard drive “falls asleep.” Also, if your DAC is
connected to a network, verify that Appletalk is “on.” Otherwise, Net Station may
freeze.
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1: Acquisition Overview
A functional diagram is shown in Figure 1-3.
Monitor
Sensor array
Amplifier
Data acquisition
computer running
Net Station
Mouse
Keyboard
Figure 1-3. Net Station Acquisition functional block diagram
Basic Operation
Physically, the sensor array connects to the amplifier via an interface cable. This is
shown in Figure 1-4. The cable allows the subject to be positioned conveniently near
the amplifier.
Figure 1-4. Sensor array, interface cable, amplifier
The array’s sensors pick up changes in voltage originating at the surface of the
subject’s head (the EEG), along with a certain amount of electrical noise originating in
the room environment. Electrical signals from all the sensors of the array are received
simultaneously by the amplifier where they are amplified, filtered, sampled, and
digitized. As quickly as the samples are acquired, they are packaged and sent to the
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1: Acquisition Overview
DAC along the Universal Serial Bus (USB) cable that connects the amplifier and the
DAC (Figure 1-5).
Data-acquisition
computer running
Net Station
Amplifier
Bidirectional USB cable
Figure 1-5. Amplifier–to-DAC connection diagram
Note: During acquisition, Net Station 4.0 presents a “disk-full” warning at 200 Mb and
stops recording at 100 Mb. This limit was chosen because OS X, on which version 4.0 is
based, does not allow you to use up the hard drive. It reserves about 250 Mb on disk.
Display and Recording of EEG
The data of each sensor are segregated into their own channels. As the samples stream
into the DAC over the USB cable, Net Station gathers, organizes, and displays each
channel’s EEG data in the manner of a traditional chart recorder (Figure 1-6).
When you instruct Net Station to record the data to a file, the chart recorder display
continues without interruption while the data are being written to disk.
Dense Waveform Display
Displaying
on monitor
Net Station
Recording
to disk
DAC hard drive
Figure 1-6. Net Station displays and records EEG waveforms
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1: Acquisition Overview
Note: If you receive a message indicating that the USB driver is not installed, try
reinstalling Net Station and restarting the computer.
Display Method
In contrast to a physical chart recorder that uses electromechanical pens to draw
waveforms on a piece of moving paper, Net Station “draws” tiny dots on the
computer screen called pixels (picture elements; Figure 1-7).
Greatly magnified view of
an onscreen waveform
showing it is made of
rectangular dots (pixels).
Figure 1-7. Onscreen waveforms are composed of pixels
You can achieve fine control of the display of EEG waveforms using the time and
amplitude controls of Net Station’s scrollable Dense Waveform Display (DWD),
shown in miniature in Figure 1-6. See Chapter 4, "Dense Waveform Display,” for
details.
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1: Acquisition Overview
Recording Method
The voltage samples pass as data packets from the amplifier to Net Station via the
bidirectional USB cable that connects the amplifier to the DAC. Net Station records
the data to disk in the form of either Recording or Session files (Figure 1-8).
Session file
Amplifier
EEG data
Net Station
— or —
Recording file
Figure 1-8. Net Station data files
Note: Because the USB cable is bidirectional, Net Station can send queries and commands
to the amplifier as well as receive data from it.
High Density and Resolution
Net Station handles heavy workloads easily. Net Station’s buffers can handle as many
as 1,000 samples per second from your sensor array. You can observe the waveforms
of each channel in groups limited only by the size of the computer monitor, even as
the data are written to disk.
Data Protection
Net Station writes EEG and events to the DAC hard drive. To maximize the protection
of these data after they are collected, the DAC must feature an optical drive (e.g.,
DVD-RAM or DVD-R) that accepts high-capacity removable media. You can, and
should, copy your data files from the acquisition hard drive to removable optical
disks. An optical recording has a life span of decades and is immune to magnetic
fields. This procedure ensures that the data cannot be lost because of hard-drive
problems, and it greatly expands the data storage capacity of the System, as well.
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chapter 2
CHAPTER
2
INTRODUCING
NET STATION
of Net Station Acquisition perform EEG data acquisition, monitor and
U sers
control the amplifier, and store subject information and technician markup events
in data files (Session or Recording) using Net Station software. This software resides
on the hard drive of the data-acquisition computer and communicates with the
amplifier via the USB cable that connects the amplifier and the DAC (see Figure 1-5 on
page 24).
Optionally, via Net Station, the Acquisition system can register and record external
digital input (DIN) events and experimental control interface (ECI) events
simultaneously with the EEG (see “Digital Input Controls” on page 62 and
“Experimental Control Status Panel” on page 83 for details).
This chapter, with few exceptions, assumes that you are familiar with the Mac OS and
its basic operation. If you need help using the mouse, choosing from menus, or
working in the Finder or with Mac OS control panels, please consult the User’s Guide
that came with your Macintosh computer, or the online Apple Guide from the Help
menu.
Note: Before using Net Station Acquisition to acquire subject EEG, study and understand
this sequence: Chapter 2, "Introducing Net Station”; Chapter 3, "The Workbench”;
Chapter 4, "Dense Waveform Display”; and Chapter 5, "Sessions and Session
Templates.”
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2: Introducing Net Station
Learning to Use Net Station
This chapter provides introductory material that is essential and/or helpful for
understanding and realizing the full capabilities of the software and lays the
foundation for Chapter 3, Chapter 4, and finally Chapter 5.
Contents of This Chapter
This chapter covers how to launch Net Station and then describes the Net Station
Distribution (i.e., the files and folders that are installed on the DAC). You should
study the Distribution to become familiar with the names and locations of the
example files that are part of the Net Station distribution, and the default files and
folders that form a vital part of the Acquisition system’s functionality. The chapter
finishes by introducing the Workbench, Acquisition Setups, and Workbench devices.
Net Station Distribution
As a part of the Net Station installation process, a number of files are placed on the
hard drive of the system DAC. Collectively, these files are called the Net Station
Distribution.
Note: This chapter uses the terms directory and folder interchangeably and assumes
basic familiarity with Mac OS configured as a single user.
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2: Introducing Net Station
Net Station Under OS X
Net Station operates slightly differently under Macintosh OS X than it did under the
previous operating system. Notable differences include the Documents folder, font
smoothing, and highlight colors.
Documents Folder
It is important to understand that OS X has a distinct Documents folder for each user.
This folder is located in the user's home directory under OS X. This documents folder
(~/Documents [the tilde denotes the current user's home directory]) is entirely
separate from the OS 9 documents folder (/Documents) located at the root level of the
hard drive.
Net Station 3.0 used the OS 9 documents folder to store the Net Station User Data
folder. Net Station 4.0 and later use the OS X documents folder to store the Net Station
User Data folders. These are not the same location, and so Net Station 3.0 and Net
Station 4.0 do not share tool specifications or settings. In addition, separate user
accounts under OS X also do not share specifications or settings.
This has the potential for creating confusion for someone who is new to OS X, or who
has been running Net Station 3.0 and is now running Net Station 4.0 or later on the
same machine. If you are missing specifications, tools, or recordings, check which
documents folder you are accessing.
Font Smoothing
For Net Station controls and text labels to be clearly readable under OS X, make sure
that System Preferences > General > “Turn off text smoothing” is set to “for font sizes
8 and smaller.” If this is set to 9, 10, or 12, Net Station labels may be difficult to read.
Highlight Colors
The default OS X highlight color may be too light for easily readable displays in
Net Station 4.0. If this is true, choose System Preferences > General to select a darker
highlight color. The Other option enables you to choose a custom, bright color.
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2: Introducing Net Station
Mac Desktop Items
The hard drive where Net Station is
installed is named “Data Acquisition.” Its
icon (Figure 2-1) is situated in the top-right
corner of the desktop. The Net Station icon
is located on the Dock in Macintosh OS X.
Clicking on the icon launches Net Station.
Figure 2-1. Desktop and
Dock icons of the Distribution
Caution!: Files and folders that are part of the Distribution should not be moved,
renamed, or deleted. Doing so could adversely affect the operation of Net Station.
For the same reason, the directory structure of the Distribution should not be
altered except where indicated in the text of this chapter.
Root Directory
Double-clicking the data-acquisition hard drive will open a window that shows its
root directory structure (Figure 2-2).
Figure 2-2. Root directory structure of data-acquisition hard drive
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2: Introducing Net Station
The exact contents of the root may include more files and folders than those shown in
the figure, but the essential ones are shown. The important folders to notice are
Applications and Documents. These two folders contain parts of the Distribution and
are also essential components of the Mac OS installation. You can add or delete your
own folders and files at any time.
Net Station Folder
Inside the Applications folder is the Net Station folder.
As shown in Figure 2-3, the Net Station folder encloses the Net Station application
program package.
Figure 2-3. Inside the Net Station folder
Also in the Net Station folder is the Extras folder.
Caution!: Do not move, rename, or delete the Net Station folder or its contents.
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2: Introducing Net Station
Net Station Application Program Package
The Net Station icon is actually a package (i.e., a folder disguised as an application
icon). Do not move, rename, or delete items from the package file or Net Station may
exhibit unexpected behavior, possibly including data corruption.
Caution!: Do not move, rename, or delete any item that is enclosed in the
Net Station Application Program Package.
Extras Folder
Auxiliary applications are distributed with Net Station in the Extras folder. You can
move such applications out of the Extras folder without adversely affecting
Net Station. The Net Station File Exporter, described in the next paragraph, is one
such auxiliary application.
Net Station File Exporter
The Net Station File Exporter is a droplet application. You can launch the Net Station
File Exporter only by dragging files onto its icon. If a Net Station Recording or Session
file is dragged onto it, the data of the file will be exported as a simple-binary data file.
See the Read Me documentation file supplied with the File Exporter in the Extras
folder to learn about the simple-binary format. (The Net Station File Formats Technical
Manual also describes the File Exporter.)
Command key
Another function of the File Exporter is to extract diagnostic and calibration
information from an EEG data file. Dragging a Net Station Recording or Session file
onto the Exporter while holding down the Command key causes the gains, zeros,
impedances, and history stored in the file to be written to separate text files. These
output files have the extensions.GAIN, ZERO, .IMP, and .HIST.
For information on how channel gains and zeros are measured, and the formula for
converting channel A/D values to microvolts, see “Calibration” in Chapter 2,
“Net Amps 200,” in the EGI System Technical Manual.
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2: Introducing Net Station
Documents Folder
The Documents folder is a default component of Mac OS.
During Net Station installation, a Net Station User Data folder is installed in the
Documents folder. The Net Station User Data folder and its contents are part of the
Net Station Distribution and are described in this section. Do not move, rename, or
delete any of the four folders (Figure 2-4) nested in the Net Station User Data folder.
Figure 2-4. Contents of Net Station User Data folder
(See “Net Station Under OS X” on page 29 for the different document folders used in
OS 9 and OS X.)
Acquisition Setups Folder
The Acquisition Setups folder stores Acquisition Setups. When you save new, editable
Acquisition Setups, Net Station routes them to this folder by default. Directly after
installation of Net Station, the Acquisition Setups folder is empty.
Note: Session Templates require an embedded Acquisition Setup (see“The Embedded
Acquisition Setup” on page 117). When you create a new Session Template, Net Station
looks for available Acquisition Setups in the Acquisition Setups folder.
Sessions Folder
The Sessions folder is the destination for saved Net Station Session files. Such files are
native Net Station EEG data files that are initiated when you pick a Session Template
and use it to acquire new EEG data (see Chapter 5, "Sessions and Session Templates”).
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2: Introducing Net Station
Support Folder
The Support folder (see Figure 2-4) holds the Resource Database, an automatically
generated file that stores user information needed by Net Station. The Resource
Database contains:
•
•
•
•
•
•
•
•
event descriptors
event sets
filter descriptors (advanced filter interface)
keyboard mapping
montages
topographic map compositions
people (global unique identifiers)
fields
Over time, Net Station adds and removes information from the Resource Database. If
the Resource Database is moved, renamed, or deleted, Net Station creates a new one
and place it in the Support folder, but as a consequence the information in the old
Resource Database is no longer be available to Net Station.
You should regularly back up your Resource Database, saving the Resource Database
backup files as a protection against the database being deleted inadvertently.
Templates Folder
Like the Acquisition Setups folder, the Templates folder is for your convenience.
When you create custom Session Templates, Net Station puts them in this folder
automatically as soon as they are saved.
Net Station looks for Session Templates in this folder when you initiate a new session.
It lists the names of any templates it finds, along with the names of its default,
preconfigured, Session Templates. You choose from the list (see Figure 5-1 on
page 116). The names of Net Station’s default Session Templates are Primitive
Session Template, Typical Session Template, and Experimental Control Template.
When creating a new Session Template, choose a name that does not match one of the
names of the default templates, to prevent duplicate names appearing in the list of
Session Templates.
Caution!: Do not move, rename, or delete this directory or Net Station will not be
able to find user-created templates.
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2: Introducing Net Station
Workbench and Devices
Net Station’s Workbench is a facility for designing and saving data-acquisition
configurations. You preserve Workbench configurations by saving them to computer
files called Acquisition Setups. You can initiate EEG data collection directly from the
Workbench or from a saved Acquisition Setup.
Typically, Net Station users will choose a Session Template for performing data
acquisition. An Acquisition Setup is embedded in each Session Template (Chapter 5,
“Sessions and Session Templates”).
For your convenience, the Distribution includes three preconfigured Session
Templates for data acquisition. If these preconfigured templates match your needs, it
may not be necessary to use the Workbench at all. Still, the following sections should
be studied and understood as background for the next two chapters, which cover a
number of topics related to data acquisition using Net Station.
Workbench Fundamentals
In an electronics laboratory, hardware often consists of modular devices on a
workbench, interconnected with cables. Such devices have their own controls,
displays, and functionality. When a new device becomes available, it is added to the
workbench collection with minimal consequence to the other devices.
Net Station’s Workbench (Figure 2-5) emulates a real-world, physical workbench
where devices can be placed (Figure 2-6) and connected together (Figure 2-7). On the
computer screen, the workbench surface is represented by a grid of rectangles called
cells. You can place a single device into each cell and connect the devices using virtual
cables.
Devices
Chapter 3, “The Workbench,”covers each device in detail. In general, however, the
following rules apply to Workbench configurations:
• Each device has a particular function (Figure 2-6).
• Each device except the Net Amps USB device has both input (left side of the
device) and output jacks.
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Figure 2-5. The Workbench
• You cable together devices by creating connections (cables) from the output
jack of one device to the input jacks of other devices.
• EEG and digital input data from the amplifier are made available to the
Workbench via the Net Amps USB device.
Net Station’s Workbench interface extends
the metaphor of a real-world workbench by
providing access to display and control
panels that are linked to the functions of the
devices.
For example, after connecting the Digital
Filter device in an appropriate way
(Figure 3-77 on page 101), click the Control
Panel button on the Digital Filter device to
deploy its control panel (Figure 2-7). Then
use the control panel to set filter parameters
and turn the filter on and off.
Figure 2-7. Example of
deploying a control panel
You can start with simple configurations
and add more devices to create more
complicated setups.
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2: Introducing Net Station
Data source, plus:
amplifier control,
calibration, analog
filtering, and
digital inputs
Montage visualization
Data display
Signal filtering (digital)
Data recorder
Experimental Control Interface
Figure 2-6. Workbench devices
Acquisition Setup
An Acquisition Setup stores a Workbench configuration including device placements
and connectivities, display and control panel settings, and window positions and
sizes.
Acquisition Setup files are editable documents. Adding and removing devices is one
aspect of editing an Acquisition Setup. Another is modifying the positions and
settings of display and control panels. You can create custom Acquisition Setups, each
with its own particular device layout and configuration.
If you modify the Workbench configuration of an Acquisition Setup, Net Station asks
you if you want to save the changes when the Setup file is closed. However, if you
modify only window positions or panel settings, then Net Station autosaves them
without asking when the Setup file is closed.
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2: Introducing Net Station
Acquiring Data
Opening a saved Acquisition Setup automatically launches Net Station and loads the
Workbench configuration the setup contains. If the setup is valid, turning the
Workbench “on” initiates EEG data acquisition.
For example Acquisition Setups, see “Default Acquisition Setups” on page 94, which
includes coverage of the three default Acquisition Setups included with the
Distribution:
• Primitive Acquisition Setup
• Typical Acquisition Setup
• Experimental Control Setup
Another way to collect data is by using a Session Template, which contains an
embedded Acquisition Setup (see Chapter 5, “Sessions and Session Templates”).
Workbench Off and On
Once the Workbench contains a source device, you can
switch on the Workbench and data will stream from the
source device into connected downstream devices. When
the Workbench is “off,” it is in a dormant state in terms of
its ability to bring a data stream into Net Station, but
devices can be added or removed. You cannot add or
remove devices or modify connections when the
Workbench is “on.”
Look for the Workbench
Off and On buttons in
the upper-right corner
of the Workbench
window.
Recording On and Off
With a Waveform Recorder connected downstream of a
source device, as in Figure 2-7, and the Workbench on,
clicking the Record button on the control panel of the
Waveform Recorder device initiates recording to disk.
Note: When the Workbench is off, the Record button is dimmed
(disabled).
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Stop and Record
buttons are located on
the Waveform Recorder
device control panel.
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chapter 3
CHAPTER
3
THE WORKBENCH
Menus and Acquisition Status
open the Workbench, launch Net Station and click the Acq Setup button on the
T osidebar.
Above the Workbench is the Net Station menu bar associated with the
Workbench, and attached to the lower margin of the menu bar is the yellow
Acquisition status panel (Figure 3-1).
When the Workbench is empty, as it is below, the
Off and On buttons are dimmed.
The Workbench is
a grid of cells.
Placing one or more devices on the Workbench activates its Off and On buttons.
As soon as the On button is clicked, the Acquisition status panel begins to display
elapsing time.
Acquisition
status panel
Figure 3-1. Menus and Acquisition status panel
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Note: Deploying the Dense Waveform Display (Chapter 4) causes additional menus to
appear on the menu bar (see “Dense Waveform Display Menu Bar” on page 84).
Each menu command is explained in “Menus” on page 83. For now, notice that the
right side of the Acquisition status panel contains two buttons for turning the
Workbench on and off. You can also turn the Workbench on or off by using the Acq
menu (see “Acq” on page 87).
The behavior of the Workbench depends on its on or off status, as explained in
Table 3-1.
Table 3-1. Workbench rules
Workbench devices function only when the Workbench is on.
Data recordings can be made only with the Workbench on.
Devices can be added, removed, or configured only when the Workbench is off.
The Record menu is not available when the Workbench is off (see Figure 3-1).
On the left side of the Acquisition status panel is the elapsed time display, showing
the time that has passed since the Workbench was last turned on, in
hours:minutes:seconds (Figure 3-2).
Figure 3-2. Acquisition status panel with Workbench on
Note: When using a Session Template to conduct EEG and event data acquisition, the Off
and On buttons that accompany the Workbench are replaced by the Session Info and
Close Session buttons. The elapsed time display is the same. See Chapter 5, "Sessions and
Session Templates,” for details.
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Devices in General
Net Station provides six Workbench devices for configuring acquisition.
Each device belongs to one of six classes, described in Table 3-2.
Table 3-2. Device class descriptions
Device class
Provides...
Display
Windows and controls for viewing waveform and event data and for
entering events.
Filter
Controls for choosing and setting parameters for digital waveform
filters.
Mixer
Windows and controls for mixing multiple channels into a single
channel.
Recorder
Controls for starting, stopping, and pausing recording.
Source
Controls for choosing the manner in which EEG and digital input event
data are acquired.
Stimulus/Response
Controls for configuring how stimulus presentation and subject
responses are handled.
On the face of the device icon, the device’s class is shown along with the device’s
name and version number. Using the Dense Waveform Display device as an example,
Figure 3-3 demonstrates that:
• A device has an input and output side.
• A device’s class is indicated by a class icon unique to the class, and the device
itself carries an icon that is unique to the device.
• A device has buttons on its face for deploying various info, display, and control
panels.
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Cables and Jacks
Devices have from zero to four input and output jacks. Inputs are located on the left,
outputs on the right (Figure 3-3). When you configure devices on the Workbench, you
drag from the output jack of one device to the input of another and thus create a
connecting cable (see “Placing and Connecting Devices” on page 45).
Class icon
Class name
Device name and version
Input side
Output side
Device icon
Info panel button
Display panel button
Figure 3-3. Dense Waveform Display device with parts labeled
Jacks are labeled and color-coded to match the four types of cables. The four jack
types are:
• EEG: Waveform I/O; colored yellow. The yellow cable carries waveform data
and all the necessary information to display such data, including sampling rate,
montage, filter, gain, scale, and source device calibration information.
• MARK: Event marking I/O; colored green. The green cable carries information
about user-generated events (e.g., technician markups that are made in the
Dense Waveform Display; see Chapter 4).
• PAT: Auto Pattern I/O; colored red. The red cable carries computer-generated
events (e.g., pattern recognition results).
• STIM: Stimuli I/O; colored blue. The blue cable carries events that originate at
the Net Amps DIN port and those sent to Net Station by an experimental
control computer (e.g., with E-Prime).
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Device Buttons
Info panel button: All devices have an information panel button identified by a
question mark. Clicking this button opens a panel that contains basic information
about the device. See “Info Panels” on page 49.
Control panel button: Labeled with a pointing hand, the control panel button deploys
floating, device-specific windows that feature a variety of control elements.
Display panel button: The “eye” indicates a button that deploys device-specific
windows containing a variety of data display elements. Some display panels have
buttons for initiating measurements, such as the Net Amps USB Device Display
Panels (page 73).
Device Panels
Net Station devices are described in Table 3-3. Table C-1 on page 137 provides a list of
the iconized versions of the panels and a page reference pointing to where each panel
is described in the text.
Table 3-3. Panel references
Device
Dense Waveform Display
EEG waveform viewer with controls for altering
the rate, scale, and appearance of dense array
EEG. Input device for technician markup events.
Digital Filter
Dense Waveform Display Info
Dense Waveform Display
Digital Filter Info
IIR filter with user-customizable settings. Use
only for visualization of data, not recording.
Bipolar Montage Editor
Digital Filter Controls
Bipolar Montage Editor Info
Channel-grouping, mixing, and rereferencing
tool. Rearranges how channels are displayed.
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Panels
Montage Controls
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3: The Workbench
Table 3-3. Panel references (Continued)
Device
Panels
Waveform Recorder
Waveform Recorder Info
Writes EEG and event data to a Session or
Recording file.
Net Amps USB
Waveform Recorder Controls
Net Amps USB Control Panels:
The control and data interface to the amplifiers.
When the Workbench is “on,” it conveys live
data and events to devices connected to it.
Net Amps Controls, Advanced Net Amps Controls,
Digital Input Controls, Amp Diagnostics
Net Amps USB Display Panels:
Gains, Zeros, Noise, Impedance
Experimental Control Interface
Experimental Control Interface Info
Transports stimulus and user response events
from the ECC to other Workbench devices.
Experimental Control Status
Devices Palette
Devices can be placed on the
Workbench via the Devices palette
(Figure 3-4) or from the Acq menu
(“Acq” on page 87). "Placing and
Connecting Devices" on page 45
describes how to access the Devices
palette and drag devices from the
palette to the Workbench. For now,
note that on the palette, the icon on
the left is the class icon. The device
icon is next to it, followed by the
device name. Beneath the name is
the device class name. The devices
on the palette are always sorted by
class name, the same sort order used
for Table 3-3.
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Figure 3-4. Devices palette
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Placing and Connecting Devices
You place devices on the Workbench and link them together with cables to create a
Workbench configuration. Devices can be moved onto the Workbench only when the
Workbench is off. Cables convey data from one device to another.
Create cables by using the mouse to drag from one jack (either input or output) to
another (Figure 3-5). Inputs connect to outputs, and vice versa. The Workbench
interface automatically rejects connections that are disallowed. If a connection is
allowed, it is valid.
Note: Not every possible Workbench configuration will produce your expected result; if
you experience difficulties with a Workbench configuration, contact EGI Technical
Support (Appendix B, "Software Technical Support”).
More than one output cable can be attached to a device so that the device’s data can
stream into more than one device simultaneously. Also, some devices accept multiple
input cables.
How to Place Devices on the Workbench
Launch Net Station and choose Acq Setup from the sidebar. The Workbench,
Acquisition status panel, and the Workbench menu bar appear (Figure 3-1).
The Workbench is a grid of rectangles. Each rectangle is called a cell. You can place a
single device into each cell.
Drag a Net Amps USB device from the Devices palette to a Workbench cell. The result
should resemble frame 1 in Figure 3-5.
Use the Acq menu to place a Dense Waveform Display device into the cell that adjoins
the Net Amps USB cell on the right. Do this by first single-clicking the cell to the right
of the one that holds the Net Amps USB device, which causes the cell to be
highlighted. Choose Dense Waveform Display from the Acq menu (see frame 2 of
Figure 3-5).
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3: The Workbench
How to Cable Together Two Devices
Connect the EEG output jack of the Net Amps USB device to the EEG input jack of the
Dense Waveform Display by placing the cursor over the output jack of the Net Amps
USB device (frame 3 of Figure 3-5), then dragging to the right until the cursor is over
the input jack of the Dense Waveform Display device. Release the mouse button to
complete the connection (frame 4 of Figure 3-5).
1.
2.
3.
4.
Figure 3-5. Cabling two devices together
When two or more devices must be cabled to the same output jack, you must drag
from the downstream device to the upstream device, or you will not be able to make
the one-to-many connection.
Core Devices
Workbench configurations need a source, display, and recorder device, hence the
following Net Station devices are termed, respectively, core devices:
• Net Amps USB
• Dense Waveform Display
• Waveform Recorder
A basic Workbench configuration consisting of only the three core devices is shown in
Figure 3-6. This is actually the configuration used in the default Primitive Acquisition
Setup (for details, see page 94).
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3: The Workbench
Source
Display
Recorder
Figure 3-6. Three core devices in a Workbench configuration
Net Amps USB Device Basics
The Net Amps USB device provides software control of the amplifier. Data being
collected by the real-world amplifier are brought into Net Station via the output jacks
of the Net Amps USB device.
The “USB” in the name of the device refers to the fact that the data being collected by
the amplifier are conveyed via a USB cable to the DAC where Net Station is running.
EEG Data Source
If the System is collecting EEG, other Workbench devices acquire access to the EEG
when their input EEG jacks are hooked up to the output jack of the Net Amps USB
device.
Digital Inputs Source
The digital inputs connector (DIN port) on the back panel of the amplifier is a parallel
port for bringing in external digital input (DIN) events into your recording. Setting up
digital inputs is accomplished through the Net Amps USB device Digital Inputs
Controls panel. Its STIM output jack is a source for DIN events when the amplifier is
configured for receiving digital inputs.
Amplifier Calibration, Impedance, and Noise
Assuming the physical components of the System are connected and switched on, the
amplifiers are calibrated using the Net Amps Controls panel of the Net Amps USB
device (Figure 3-21). Such calibrations can be automated using an appropriate Session
Template (see “Automatic Amplifier Calibration” on page 126). Likewise, sensor
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3: The Workbench
impedances (“Impedance Display Panel” on page 79) and noise (“Noise Display
Panel” on page 76) can be measured and stored in a retrievable way.
Analog Signal Filtering
Analog signal filtering (hardware filtering) settings are made using two panels:
• Net Amps Controls panel (lowpass filter only)
• Advanced Net Amps USB Controls panel (highpass and lowpass)
See “Net Amps Controls” on page 58, and “Advanced Net Amps Controls” on
page 62.
Control and Display Panels
Net Amps USB device control panels are described beginning on page 58. Net Amps
USB device display panels are described beginning on page 73.
Dense Waveform Display Device Basics
The Dense Waveform Display device (Figure 3-7) is used for viewing EEG waveforms
and event tracks. In addition, it is an input interface for technician markup events that
can be entered and recorded along with the EEG in the Dense Waveform Display
“mark” event track.
EEG and DINs are correctly set up for display by the Workbench configuration shown
in Figure 3-6. The EEG and STIM cables are both connected from the source device to
the DWD. For details on the Dense Waveform Display, see Chapter 4.
Figure 3-7. Example Dense Waveform Display
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Waveform Recorder Device Basics
Recording EEG to disk is accomplished by cabling EEG data on the Workbench to the
Waveform Recorder device. The Workbench configuration in Figure 3-6 shows that
the EEG data cable coming out of the Net Amps USB device does not need to connect
directly to the input of the Waveform Recorder. The data can “pass through” another
device on their way to the recorder. In this case, they pass through the DWD.
In the Workbench configuration shown in Figure 3-6, DIN events are conveyed to the
recorder by connecting the STIM output of the source device to the DWD and hooking
the STIM output of the DWD to the recorder’s STIM input. DIN events will be
recorded along with the EEG. No time delay is introduced by the DWD device being
connected between the source and recorder devices.
The Dense Waveform Display device provides an interface for entering technician
mark events into a recording. For these events to be registered in a recording, the
mark input of the Waveform Recorder device is connected to the mark output of the
Dense Waveform Display (as in Figure 3-6).
Device Panels
In most cases, device panels are deployable via device buttons (see “Device Buttons”
on page 43) and optionally by menu commands that Net Station installs in the Panels
menu (see “Panels” on page 88), depending on which devices are part of the active
Acquisition Setup. An exception is the Net Amps USB device. Some of the control and
display panels for this device are available only from the Panels menu.
Info Panels
Associated with each device is a Device Info
panel (Figure 3-8). This panel contains general
information about the device, including version
number.
Figure 3-8. Info panel
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Control Panels
The following sections cover the control panels associated with each device.
Digital Filter Controls
The Digital Filter controls panel is available from the Digital Filter device’s Control
Panel button or from the Panels menu (Figure 3-9). But see page 52 for a caution
against placing this Filter device in a configuration that would result in digitally
filtered data being recorded.
Figure 3-9. Digital Filter Controls
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Control Panel Description and Usage
You customize a Digital Filter device’s effect by choosing to activate one, two, or all
three of the available filter effects:
• lowpass
• highpass
• notch
Activate lowpass digital filtering by toggling the
Lowpass button to its “on” position (Figure 3-10) and
clicking one of the available presets below the button.
The selected preset is highlighted. The Highpass and
Notch toggle buttons work exactly the same way.
The presets of a given list are mutually exclusive choices,
but the Lowpass, Highpass, and Notch buttons can be set
in any combination.
Lowpass effect off
Lowpass effect on
Figure 3-10. Effect of
toggling the Lowpass button
When a Digital Filter device’s input is connected to an
EEG cable carrying EEG, the output jack of the Digital
Filter device produces filtered EEG according to the
Figure 3-11. Appearance
activated preset effects—but only if the Digital Filter
of buttons when filter is on
device has been turned on. In the top-left portion of the
control panel are two buttons you use to turn the Digital
Filter device off and on. These buttons indicate by their appearance (Figure 3-11) the
current state of the device. When it is on, the filter produces an effect that is a
combination of your selections (see example in the following "Filter Types" section).
When the Digital Filter device is off, data pass through it unchanged.
Filter Types
Lowpass filters pass low frequencies and attenuate high frequencies.
Highpass filters pass high frequencies and attenuate low frequencies.
Notch filters are set to attenuate a single frequency, for example, 50 Hz or 60 Hz, with
sharply limited attenuation of frequencies above and below the target frequency.
Bandpass and bandstop filters are shorthand ways to describe a combination of
lowpass and highpass filters. Bandpass filters attenuate frequencies on either side of a
band, allowing the band to pass unattenuated. Bandstop filters attenuate frequencies
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3: The Workbench
above a certain frequency and below a higher frequency, so that only frequencies not
in the band are allowed to pass unattenuated. A notch filter is a kind of bandstop
filter, one with a particularly sharp profile.
For example, you can choose a 1–100 Hz bandpass filter by picking a 100 Hz lowpass
filter and a 1 Hz highpass filter. Next to the On button a label will appear, describing
the filter that has been built.
Clicking the close button of the control panel or choosing Close Window from the File
menu causes the control panel to disappear, but the filter is still active as long as the
Workbench is on and the panel was closed with its On button selected.
Multiple Digital Filter devices can be used in a Workbench setup, each with its own
parameters.
IIR Filtering
Net Station offers IIR filtering
using the Digital Filter device. IIR
filtering is rapid, but an IIR filter
lacks linear phase response (the
amount a filter shifts each
frequency component in time).
Figure 3-12. Recording of IIR-filtered data is inadvisable
Linear phase response is necessary to obtain a filtered signal with no distortion. The
inherent distortion of IIR filtering disqualifies it for use in transforming data, but it is
adequate for data visualization. IIR filtering is very useful, for example, for observing
real-time waveforms with the 60 Hz environmental noise filtered out.
Net Station presents a Caution message whenever you cable together a Workbench
configuration that has a recorder device downstream of the Digital Filter device
(Figure 3-12). You are free to click the OK button in the Caution dialog and accept the
configuration, but see the Caution message below.
Caution!: Connecting an active Digital Filter ahead of and in series with the
Waveform Recorder device results in filtration of the data being recorded. IIR
filters are not appropriate for this purpose. Do not connect a Digital Filter device
in such a way that the data are acted upon by the filter before they are recorded.
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Montage Controls
The term montage refers to a specific
way of defining sensor data
visualization.
The Montage controls panel (Figure 313) is deployed by clicking the Control
Panel button of the Bipolar Montage
Editor device. When the Workbench is
off, the montage list is not displayed
in the panel. When the Workbench is Figure 3-13. Montage controls panel (Workbench on)
on, single or multiple montages will
be listed.
Net Station includes preconfigured montages for Systems using the Geodesic Sensor
Nets. The ones that match the channel count of the Net being used will appear in the
list if a Net is connected to the system. If a Net is not connected, only default channelcount montages are listed.
Rereferencing the signals of all the sensors of an EGI Net to a reference consisting of
the mean signal of all the sensors is called average referencing. An average reference
montage appropriate to the connected Net’s sensor density is included in the montage
list.
You can choose other available default montages from the list. Clicking the “eye” icon
to the left of any montage label in the Montage controls panel moves the “eye” icon to
the selected montage, and the EEG channels being displayed in the Dense Waveform
Display (Chapter 4) will immediately reflect the newly selected montage.
Note: Applying a montage does not alter the data being recorded; it only modifies the way
the data are displayed onscreen.
Sensor maps showing the architecture of the default listed montages for EGI’s 64-,
128-, and 256-channel Nets are given in Appendix D, "Montages,” which includes a
table indicating the referencing scheme for each montage.
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Waveform Recorder Controls
Introduction
The job of the Waveform Recorder device is to take the data coming in to its inputs
and write them to Net Station Recording and Session files (see “Recording Modes” on
page 55).
With the Workbench, you take control of recording via the Waveform Recorder
Controls panel (Figure 3-14), which features tape-recorder–style Stop and Record
buttons. You toggle between two sizes of the control panel using its “anchor” button.
The minimized or “small controls” version of the control panel is not movable and
anchors to the bottom of the screen. The “large controls” version can be repositioned
anywhere on the screen by dragging.
Button for
toggling between
minimized and
full-sized versions
of the Waveform
Recorder Controls
panel.
Figure 3-14. Waveform Recorder Controls (Workbench off)
When recording a Session file using a Session Template, the Waveform Recorder
Controls panel is identical to its Workbench version except for the New and Close
buttons being replaced by a Session Info button (Figure 3-15). The anchor and other
buttons work the same way.
Session Info button
Figure 3-15. Waveform Recorder Controls detail (Session)
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Recording Modes
Net Station writes two EEG data file types:
• Net Station Recording (not to exceed 2 GB)
• Net Station Session (not to exceed 2 GB)
Net Station Recording File
You create Net Station Recording files by using the
Workbench environment. As soon as you click the Record
button of the Waveform Recorder Controls panel, Net Station
starts writing a file. The elapsed time area of the panel
changes from yellow to red and the elapsed time counter
begins (Figure 3-16).
Clicking the Stop button suspends recording but does not
close the Recording file. Clicking the Record button after Stop
reinitiates recording to the same file, appending additional
data to it.
When you click the Close button on the control panel, the
Recording file closes and cannot be overwritten or appended
to. You can initiate a new Recording file by clicking Record.
Toggling Record and Close creates successive recording files
that are autonamed in the series, “Recording 1,” “Recording
2,” and so forth. The default destination of these files is the
Sessions folder (see page 33 for details).
Figure 3-16. Click the
Record button
Clicking the New button invokes the appearance of a file-naming and destination
window. Typing a file name overrides the default autonaming scheme.
Recording files can contain multiple epochs of EEG. As noted earlier, the Stop button
halts recording without closing the file. Clicking the Record button appends data to
the file until you click the Stop button again. In this way, the resulting Recording file
will contain a sequence of multiple epochs delineated by epoch boundaries.
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Net Station Session File
You use a Session Template to initiate Session files. When a new session is initiated,
the Waveform Recorder Controls panel becomes available on the Panels menu after
you click the Begin Session button in the New Session panel.
Record and Stop buttons work the same way in a
session as they do when you are using the
Workbench (see earlier) and allow you to create
multiepoch files.
Figure 3-17. Session Info and
Close Session buttons
Close the Session file by clicking the Close Session
button (Figure 3-17), which occupies the right side of
the Acquisition status panel when a session is under way.
During a session, the Close Session button performs the same function as the Close
button on the Waveform Recorder Controls panel when you are using the Workbench.
For an example Session, see Chapter 5, “Sessions and Session Templates.”
Time Indicator and Disk Monitor
Figure 3-18 shows how the Waveform Recorder Controls panel might appear during
Workbench recording. The two disclosure triangles independently toggle the
deployment of the Time Indicator and Disk Monitor subpanels.
The Time Indicator subpanel works just like the Elapsed Time area. During recording
and at pauses during recording, it reports the passage of time using a chosen time
mode (see the next section, "Time-Mode Buttons").
The Disk Monitor shows how much space or recording time is left on the disk to
which the recording is being made.
Note: It is safe to toggle the radio buttons of the Disk Monitor subpanel during recording.
This has no effect on the data being recorded.
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Time-Mode Buttons
With its two time-mode buttons (see Figure 3-18), the Waveform Recorder Controls
panel allows you to monitor elapsed time in more than one format simultaneously.
Net Station’s time modes are shown in Table 3-4. You can select Absolute, Relative, or
Epoch mode by toggling a time-mode button. Toggling the time-mode buttons is
permitted during recording and does not affect the data being recorded.
Recording Time mode is not one of the options; it is available only in the Dense
Waveform Display (page 109).
Name of Recording file
currently being written
Elapsed time area
Time-mode button
Timed Record button and box
Time Indicator subpanel
Disk Monitor subpanel
Figure 3-18. Expanded Waveform Recorder Controls panel
The time-mode buttons do not acquire a “pushed-in” appearance, but the symbol
displayed on the face of such buttons always reports the time mode that is in effect.
Table 3-4. Time modes
Symbol
Time mode
Absolute (Clock)
Time reckoning scheme
980105/18:39:11
date (yymmdd)/hour:minute:second
Relative (Workbench)
00:03:22
hour:minute:second
Epoch
[3]00:08:23
[epoch number]hour:minute:second
Recording
00:05:59
hour:minute:second
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Timed Record
The button and field labeled “Timed Record button and box” in Figure 3-18 provide a
means for stopping a recording after a set period of time, with the default time equal
to 20 seconds. This feature is useful when a series of epochs needs to be generated,
each with exactly the same duration.
Timed Record
mode is ready but
not set.
Timed Record
mode is set and
box is editable.
Figure 3-19. Using the Timed Record feature
When the Timed Record button is initially pushed in, the box displays the default set
time of 20 seconds, and the box becomes editable (Figure 3-19). Editing is performed
by selecting each digit individually and typing over it to create a new set time, which
will persist until edited again.
Whenever the Timed Record box is displaying a set time, clicking the Record button
on the Waveform Recorder Controls panel causes timed recording to begin. As soon
as recording begins, the Timed Record box becomes a countdown display, ticking off
the seconds until the new epoch is finished being recorded. The box then reverts back
to displaying the duration that was last set.
Net Amps Controls
Unlike other Net Station devices, the
Net Amps USB device has multiple control
panels.
When the Net Amps USB device is a part of
Figure 3-20. Net Amps USB Control
a Workbench configuration, the Panels
panels (Panels menu)
menu displays its four control panels as
shown in Figure 3-20. Chief among these panels is the Net Amps Controls panel,
which gives access to and control over the Net Amps sampling rate, lowpass
hardware filter, multifunctional amplifier calibration sequence, and impedance
measurement interface.
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Each of the four Net Amps Controls panels is described later in this chapter, starting
with the components that make up the panel (Figure 3-21).
Notification area
Sampling Rate buttons
Lowpass Hardware Filter slider
Amplifier calibration and sensor
impedance measurement
Figure 3-21. Net Amps Controls (default settings)
Notification Area
The notification area delivers information about the status of Net Station’s USB
connection to the Net Amps. For example, if Net Station detects that an amplifier is
not connected, it displays the following message against a red background:
.
Sampling Rate Settings
Net Station defaults to collecting EEG at 250 samples per second, but you can click a
Sampling Rate button to change this, even during recording. However, changing
sampling rates during recording can complicate subsequent data analysis.
When recording begins, the initial sampling rate setting is stored in the Sampling Rate
track of the Recording or Session file. Any subsequent sampling rate changes that you
may make during recording are also registered in the Sampling Rate track with the
time of their occurrence.
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Lowpass Hardware Filtering Settings
Net Amps electronics perform lowpass analog filtering before digitization. Controls
for setting the lowpass cut-off frequency are on both the Net Amps Controls panel
and Advanced Net Amps Controls panel (see page 58).
The default cut-off frequency is close to the Nyquist frequency, subject to the setting
of the Auto Set to Nyquist checkbox on the Advanced Net Amps Controls panel.
Note: See “Antialiasing and Lowpass Filtering” in Chapter 2, “Net Amps 200,” in the
EGI System Technical Manual, if you are considering setting the lowpass cutoff below
the Nyquist frequency, which generally is not recommended.
Amplifier Calibration
Clicking the Calibrate Amplifier button initiates an amplifier zero and gain
measurement. See “Calibration” in Chapter 2, “Net Amps 200,” in the EGI System
Technical Manual for complete coverage of this topic, including:
• amplifier calibration process
• gains and zeros
You will see the Measuring Zeros progress bar (Figure 3-22) after clicking the
Calibrate Amplifier button. Zeros calibration is performed first, followed by gains
calibration. You can cancel both gains and zeros calibration by clicking the Cancel
button on the Measuring Zeros progress bar at any time while zeros are being
measured. Once the Measuring Gains progress bar appears, you can cancel only the
gains measurement.
Figure 3-22. Calibration progress bars
Net Station stores gains and zeros measurement sets in Amplifier History files that are
sequestered in the Net Station Package file. To review past measurements of gains
and zeros, use the Gains display panel and Zeros display panel (see coverage
beginning on page 75).
Net Station checks for out-of-range values for gains and zeros and issues a message if
any channel exhibits an out-of-range value. A channel gain is in-bounds if it is
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between 50% and 150% of its nominal value. A channel zero is specified to be inbounds if it is between –100 µV and +100 µV. If an out-of-range condition occurs,
follow the instructions presented by the Net Station message.
Note: The Gains display panel and Zeros display panel (page 75) also present buttons for
initiating gains and zeros measurements, and when used in tandem they duplicate the
functionality of the Calibrate Amplifier button. The Calibrate Amplifier button always
performs zeros calibration first, then gains calibration. When using the display panels to
initiate calibration, the order of these measurements is unimportant.
Sensor Impedance Measurements
A sensor array must be plugged into the System for impedances to be measured.
Attempting to measure impedances without an array connected, or disconnecting an
array during an impedance measurement, will generate an error message.
Net Station begins to measure the contact impedance at each sensor location when
you click the Measure Net Impedance button on the Net Amps Controls panel. You
can also initiate sensor impedance measurement by clicking the Measure button on
the Impedance display panel (see “Impedance Display Panel” on page 79). In both
cases, the result is the same: the Impedance Measurement window (Figure 3-48)
opens and a sensor impedance measurement begins (for details see page 81).
A progress bar at the bottom of the Impedance Measurement window is active during
the time this window is frontmost on the screen. Net Station performs a scanning
operation and reports on it via the progress bar. As soon as Net Station has scanned all
the sensors of the array, it updates the window with the latest impedance values,
showing them as a list and refreshing the color-coding of the sensor layout.
Net Station repeats this cycle until you click the Close or Save & Close button.
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Advanced Net Amps Controls
You deploy the Advanced Net Amps Controls
panel (Figure 3-23) by choosing it from the
Panels menu.
A choice of Bessel or elliptical (the default)
lowpass hardware filtering and an Auto Set to
Nyquist checkbox are provided in the upper
Figure 3-23. Advanced Net Amps
Controls panel (default settings)
subpanel. See “Antialiasing and Lowpass
Filtering” in Chapter 2, “Net Amps 200,” in
the EGI System Technical Manual for a discussion of filter types.
Highpass Hardware Filtering
The lower subpanel of the Advanced Net Amps Controls panel is where you can
choose the cut-off frequency for the Net Amps highpass filter, with a 0.1 Hz cutoff
being the default. Before changing the default, you should study and understand the
rationale and theory behind highpass hardware filtering in “Highpass Filtering” in
Chapter 2, “Net Amps 200,” in the EGI System Technical Manual.
Digital Input Controls
Choosing Digital Input Controls from the Panels menu invokes a control panel to
configure how external digital input events are captured by Net Station via the
Net Amps.
Background for Using Digital Input Controls
Every Net Amps amplifier has a nine-pin (DB-9) connector (the DIN port) on its rear
panel for connection of external devices such as the response pad or external circuitry
(see “Digital Input Controls” on page 62). Net Station monitors this DIN port for
external events. The Dense Waveform Display shows real-time DIN events in its
tracks area in synch with EEG acquisition.
You can monitor as many as four external signals simultaneously through pins 1–4 of
the DB-9 connector. When digital input events are being monitored and recorded
along with EEG, they are synchronized with the EEG, with millisecond accuracy.
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You may not need or want Net Station to monitor pins 1–4 of the DB-9 connector. This
capability is configurable using the Digital Inputs Controls panel (see page 64).
Mapping Pin Numbers to Net Station Digital Input Events
Because you can toggle a total of four pins on the DB-9 connector independently, a
maximum of 24 = 16 event states are possible. Each event state corresponds to a digital
input channel.
Net Station maps the DIN port into the four bits corresponding to a binary number
(Figure 3-24) such that each combination of events corresponds to a number between
0 and 15. Hence, the digital input channels recognized by Net Station can be
numbered from 1 to 14, with the remaining event state (no events on any pins) being
undesignated as a channel because it is the absence of any digital input.
BITS =
4
3
2
1
GND
Figure 3-24. DIN port pin numbers map to bits
Acquisition Setup Connections
The STIM jack of the Net Amps USB device is a
spigot for digital input events that are captured
at the DIN port by the physical Net Amps 200
(Figure 3-25).
DIN events will not be recorded unless a STIM
cable is connected in a manner that allows flow
from the Net Amps USB device to the
Waveform Recorder. The events will not be
visible in the Event track of the Dense
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Digital
input
events
Figure 3-25. Connect STIM to deliver
digital input data to downstream device
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3: The Workbench
Waveform Display unless the STIM cable is connected so that DIN events can flow
into the Dense Waveform Display device STIM input jack.
Physical Connections
Two sections of the EGI System Technical Manual provide details on connecting
external signals to the DIN port of the Net Amps:
• “DIN Port” in Chapter 2, “Net Amps 200”
• “Response Pad” in Chapter 9, “System 200 Accessories”
Verify that the Workbench is “off” before attaching devices (e.g., AV tester) to the DIN
port, otherwise you may receive an error message.
Digital Input Controls Panel
After you connect a response pad or similar device to the DIN port, you must invoke
the Digital Input Controls panel in Net Station and make settings that are appropriate
to the input device and how the events are going to be displayed and recorded.
The basic appearance of the panel is shown in Figure 3-26, which indicates how
clicking the disclosure triangle either reveals or hides the tabpanel where you make
your settings.
Note: The controls of the Digital Input Controls panel are dimmed and unavailable when
the Workbench is on. To use the controls, first turn the Workbench off.
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Source Tabpanel
Use the Source tabpanel to choose the mechanism
for capturing external events (Figure 3-26). The
EGI Response Pad is the default.
If no external devices are linked to the DB-9
connector, Net Station ignores the settings of the
Digital Input Controls panel, unless you have
chosen to designate the keyboard for digital
input.
Set the EGI Response Pad button when an EGI
response pad is linked to the Digital Inputs
connector on the back of the Net Amps.
Figure 3-26. Digital Input Controls
panel, with Source tabpanel selected
Set the TTL button when a custom-designed circuit for generating external events has
been linked to the Net Amps digital inputs connector. Such a circuit must be able to
put TTL-level signals on the DIN port pins. The external circuitry should hold a DIN
port pin at ground when not generating events. To generate an event, the circuitry
should put a positive TTL-level voltage on the pin momentarily or for a period of
time. Such events will be recognized by Net Station appropriately if TTL has been set
in the Source tabpanel.
Set the Keyboard button for demonstration purposes only. DIN events will be
generated when keyboard buttons are pressed, but without millisecond accuracy.
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Tracks Tabpanel
Net Station provides a maximum of eight tracks for registering and recording digital
input events. The Tracks tabpanel shown in Figure 3-27 exhibits Net Station’s default
naming scheme for the tracks (DIN 1–DIN 8). You can edit the text boxes next to the
track numbers to rename the tracks. After an Acquisition Setup is saved, your track
names will persist in the Net Station interface and in the recorded files.
Events Tabpanel
Use the Events tabpanel (Figure 3-27) to set up which digital input channels should be
monitored by Net Station.
Figure 3-27. Tracks and Events tabpanels
The controls on this panel consist of preset buttons and the Advanced Event Setup
button.
Eight pins on the DB-9 digital inputs connector can receive external events, but not all
the pins may need to be monitored. For example, a single response pad has only four
keys that are linked to pins 1–4 of the connector. The Events tabpanel permits you to
configure the monitoring of digital inputs in a way that is appropriate for your work.
With the response pad, this would most likely be the 4 Channels preset.
Notice in Figure 3-27 that the bottom of the tabpanel contains the words “1 Active
Event.” This is a visual feedback feature for users, indicating which of the digital
input configurations is in effect.
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Advanced Event Setup
The Advanced Event Setup button opens the Advanced Event Setup panel. An
example setup is presented in Figure 3-28. Digital inputs are configured for recording
events occurring on any combination of four DB-9 pins. The total number of possible
pin combinations is 42 = 16. (The Advanced Event Setup shows 15 channels, with the
16th corresponding to “no events.”)
Figure 3-28. Advanced Event Setup
Each digital event channel has a label number with a graphical representation of its
binary code next to it. The binary code corresponds to events occurring on the pins of
the DB-9 connector.
Clicking a channel selects and highlights it. Select noncontiguous channels by clicking
on them while pressing the Command key. Select multiple contiguous channels by
dragging across them.
Figure 3-29. Channel 1 after being selected
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Selecting a channel (Figure 3-29) activates the subpanels to the right of the channel
display area.
The Event Identifiers subpanel contains a code and/or
label that will then be associated with the selected
channel(s). Figure 3-30 shows the Event Identifiers
subpanel with the default values displayed. Note that the
Enabled checkbox is selected by default. This means that
Net Station will look for events on the selected channel.
Toggling the Enabled box off causes the channel to be
ignored by Net Station.
Figure 3-30. Event
Identifiers subpanel
Figure 3-31 shows an example of how text entered in the Event Identifiers subpanel
propagates to the selected channel in the channel list. But only after the OK button has
been clicked do the user’s code and label become associated with the selected channel
(Figure 3-32).
Figure 3-31. Editing code and label of a channel
Figure 3-32. After you have clicked OK, the code and label are set
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DIN Event Structure
A DIN event always has an
associated Event Identifier Code
and Label. The Code must have a
value, but the Label can be blank.
Net Station puts the default value,
“DIN” in the Code area, but
leaves the Label area blank.
All DIN events also have a key list
(Figure 3-33), which may be
empty or contain from one to
three key-value pairs:
DIN Event
Identifier
Key list
Code
*Key code
Label
*Global key code
*Channel key code
* optional
Figure 3-33. Anatomy of DIN event
• KeyCode : Value
• Global Key Code : Value
• Channel Key Code : Value
The key list of a DIN event has all three by default, shown by the boxes associated
with the key-list items being checked (Figure 3-34).
Event Keys
The default key code is “CHAN” (Figure 3-34),
but you can rename it, if desired. The default
value for the key code is the DIN channel
number, but it too may be changed (in the Key
Value subpanel).
Event Counters
Figure 3-34. Keys and counters
Net Station counts DIN events as they are
received at the DIN port. The Global Key Code item of the key list holds a count of all
DIN events that have been received. The Channel Key Code item holds a count of all
DIN events of the channel to which the DIN belongs.
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Input Matching
The lower-right corner of the Advanced Event Setup
panel contains the Input Matching and Track controls.
Figure 3-35. Edge vs. pulse
Selecting the Edge button causes Net Station to register a single event when it detects
a switch has changed its state from open to closed or closed to open, or when the TTL
state of the pin has changed from positive to zero or zero to positive volts. When the
electrical condition of the pin returns to its prior state, Net Station becomes ready
once again to register a single event when and if the pin changes state again. In other
words, when Edge is selected, Net Station registers the occurrence but not the
duration of digital input events.
Selecting Pulse means that Net Station registers an event when it detects a change of
state, and keeps registering events until the pin changes state. In this way, both the
occurrence and the duration (number of samples that are acquired while the pin was
in its change of state) are registered by Net Station.
The Input Matching default is Edge. You can mix and match if you wish, setting some
channels to Edge and others to Pulse.
Assigning Digital Inputs to Net Station Event Tracks
DIN events are recorded into one or more tracks. In the Dense Waveform Display,
events can be viewed in the Tracks area and matched to the EEG waveforms that were
occurring at the times the events were recorded (see “Tracks Area” on page 111).
Note: Net Station’s eight event tracks for recording DINs have default names, DIN 1 to
DIN 8 (Figure 3-36). As described in “Tracks Tabpanel” on page 66, you can rename the
event tracks Net Station uses to register digital input events. The following section
assumes that the event tracks have not been renamed.
A channel’s events are assigned by default to a particular event track (Table 3-5).
Table 3-5. Default channels to tracks assignments
Preset
70
Default event track(s)
Single Channel
DIN 1
4 Channels
DIN 1–DIN 4
8 Channels
DIN 1–DIN 8
15 Channels
all DIN 1
255 Channels
all DIN 1
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Especially in the case of the 15- and 255-channel
presets, you may find it useful to reassign channels
to event tracks that differ from the defaults. After
you select a channel in the Advanced Event Setup
panel, the Track assignment pop-up menu
Figure 3-36. Track pop-up menu
(Figure 3-36) is deployed and an event track
selected. The channel display area updates to show the new assignment, but you must
click the OK button for the setting to be made. If you plan to make a number of
reassignments, it is best to enter all or groups of them at one time before clicking the
OK button because the button closes the Advanced Event Setup panel.
Presets Subpanel
The lowermost portion of the Advanced Event Setup panel contains the Presets
subpanel (Figure 3-37), with selections that match the choices on the Tracks tabpanel.
Figure 3-37. Presets subpanel
The Presets subpanel provides a convenient
way to set Edge vs. Pulse, Code, and Event
Keys for a given preset, or to reset all
channels of a preset to the default settings.
The Setup Inputs panel that appears when you
click the 8 Channels Presets button is shown in
Figure 3-38.
Figure 3-38. Example Setup Inputs panel
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Using Digital Inputs
When digital inputs are enabled and the
Digital Input Controls panel is onscreen, the
top part of the panel becomes a display device
that registers events as they occur (see
Figure 3-39). The event channels are indicated
visually, with hexadecimal labels, and with
corresponding decimal labels at the same time.
Even as the digital input events are displayed
in this manner, the Dense Waveform Display is
registering the DINs in its Tracks area, as
explained in Chapter 4, "Dense Waveform
Display.”
Figure 3-39. Digital inputs display
Amp Diagnostics
The Amp Diagnostics panel is for the use of EGI technicians and is not covered in this
manual. To make changes to this panel, contact EGI Technical Support (Appendix B,
"Software Technical Support”).
Display Panels
The following sections cover the display panels associated with each device.
Dense Waveform Display
The DWD (Figure 3-40) is invoked via the display panel button on the Dense
Waveform Display device. You can also toggle it into view using the Panels menu.
When the DWD is deployed, the menu bar will present additional menus, shown on
page 84 and described in “Menus” on page 83.
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The DWD is covered in detail in Chapter 4, "Dense Waveform Display.
Figure 3-40. Example Dense Waveform Display panel
Net Amps USB Device Display Panels
Gains, zeros, noise, and impedance diagnostic measurements are made in response to
user requests. Each type of measurement has a corresponding Net Amps USB display
panel:
•
•
•
•
Gains
Zeros
Noise
Impedance
Note: The Impedance Display panel is associated with an Impedance Measurement panel
that displays a sensor layout. The other three display panels have no such associated
sensor layout panel.
After obtaining one of these diagnostic measurements, Net Station stores the results
and displays the channel-by-channel values in the display panel. Each of the
diagnostic panels has the same user-customizable architecture, as described in the
following sections of this chapter.
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Deployment
The Display button on the Net Amps USB device controls the simultaneous
deployment of both the Zeros Display panel and the Gains Display panel. To deploy
the Noise and Impedance Display panels, use the corresponding menu commands
(see “Panels” on page 88).
Each display panel can be iconized to save screen space by using the Iconize
command from the Panels menu, or via the keyboard shortcut, z-\. Note, however,
that palettes have priority to any window they float over with respect to the Iconize
command. To iconize a display panel, it may be necessary to first iconize any palettes,
then iconize the display panel. You can return the palettes to normal size by doubleclicking their icons.
Organization and Function of Display Panels
Each of the four panels has a similar layout, as shown in Figure 3-41.
1
2
3
7
4
5
6
Figure 3-41. Generic Net Amps display panel
The following are brief descriptions of the numbered items from Figure 3-41.
1. Insets area. Presents plots of the current measurement set.
2. Measure button. In each of the four display panels, clicking this button tells
Net Station to initiate a new set of measurements, obtaining a new measurement for
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each channel. When you use this button to initiate an impedance measurement, the
Impedance Measurement window is displayed.
3. History area. Displays a list, by date, of all measurement sets. Each element in the
list constitutes an entry that Net Station has stored in an Amplifier History file.
Selecting an entry from the list triggers all displays in the panel to update, showing
the measurements for that History entry.
4. Channel list. In this list, the values of a selected measurement set are shown as
channel number/value pairs, sorted by channel number. Selecting a channel or group
of channels in the list causes the graphic plots to display that selection.
5. Display buttons. The left button activates a graphical display of the selected
measurement, the right button a spreadsheet-style display. When both buttons are
pushed in, the main area splits to present both the graphical and spreadsheet-style
displays.
6. Statistics area. Displays the mean, median, and variance of the selected
measurement. This area is blank when there are no measurements to select or when
none are selected.
7. Main area. Responds to the settings of the display buttons (5).
Gains and Zeros Display Panels
The gains and zeros panels provide access to measurement sets performed during Net
Amps calibrations.
You can perform a gains or zeros measurement at any time, but are advised to do so
without a Net connected to the System. If the Calibrate Amplifier checkbox in the
Create New Session Template window is selected when a Session Template is saved,
both measurements will be made automatically whenever a new Session is initiated.
For the Gains display panel, the example in Figure 3-42 shows a History area that
contains two entries, with the lower entry selected. Selecting the top entry would
cause all the plots in the Gains display panel to update, showing the measurement set
data for the newly selected History entry. In this example panel, the Insets area
contains three user-selectable plots. Whichever plot is currently selected will be
repeated at higher resolution in the main area of the panel.
The Zeros display panel works the same way.
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History area with
measurement set selected
Figure 3-42. History area and insets of the Gains display panel
Noise Display Panel
Noise is any component of a signal that does not contain useful information.
Net Station gives users a view of how amplifier noise is affecting the signals that
Net Station is acquiring, on a channel-by-channel basis, and allows storing of
previously acquired noise profiles.
When Net Station conducts a channel-by-channel noise measurement, the Net Amps
front-panel Hypertronics receptacle is internally disconnected from the Net Amps
circuitry. This means that the noise being measured does not include components that
may be picked up by the interface cable or the sensor array.
Noise that is part of an EEG signal has a number of sources. Some noise originates in
the electronics of the amplifier. Problematic noise originates from the environment in
which the Net Amps is operating and contaminates the EEG signals by being
acquired along with the EEG. The Noise panel provides a window into the noise
levels and noise characteristics of a given environment.
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Note: When the Net noise test is run from the Noise display panel, the lowpass hardware
filter cut-off frequency is automatically set to 400 Hz. (The waveforms may display an
increase in noise in the DWD during the test because of the higher throughput of noise in
the frequencies that are typically attenuated during data acquisition.) After the test, the
filter returns to its previous setting.
In a relatively low-noise environment, the Noise panel would look similar to the one
shown in Figure 3-43. The plot in the main area of the panel shows graphically the
microvolt RMS noise values for each channel, and the table view shows the same
information. Although the amount of noise on each channel is not uniform, all
microvolt RMS noise values are within the green portion of the chart. As the vertical
scale of the chart indicates, this means that all channels have noise values below
1.0 µV RMS. The exact noise values are shown in the table next to the plot.
Figure 3-43. Noise measurement in a low-noise environment
Clicking the Noise Distribution inset (Figure 3-44) fills the chart display with an
enlarged view of the Noise Distribution histogram and presents the same information
in an adjoining table (Figure 3-45).
As you move the cursor over the bars of the histogram, the bar under the cursor
changes color and the precise noise value it is associated with appears at the top of the
bar. The Noise vs. Time inset plot operates similarly.
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Noise Distribution inset
Figure 3-44. Noise panel insets
Figure 3-45. Noise Distribution histogram
In a noisier environment, the Noise display panel would look more like the one
shown in Figure 3-46. Taking note of the vertical scaling of the chart, which ranges
from 0 to 4.0 µV RMS, you see that the channel noise is mostly at levels above the
amplifier specification of 1.0 µV RMS but still below 4.0 µV RMS. This is indicative of
noise being picked up from the environment, combined with intrinsic amplifier noise.
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As the Noise Distribution histogram in Figure 3-46 reveals, the levels of noise
affecting the channels can display modality. This information can be useful in
troubleshooting.
Figure 3-46. Noise panel in a noisier environment
Impedance Display Panel
Sensor impedance measurement sets are displayed and graphed in the Impedance
display panel. You can initiate a new impedance measurement from this display panel
by clicking the Measure button (see example panel shown in Figure 3-47). (The other
way to initiate impedance measuring is by using the button on the Net Amps
Controls panel [see Figure 3-21 on page 59].)
Initiating a new impedance measurement opens the Impedance Measurement
window, described in detail in the next section.
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Figure 3-47. Example Impedance display panel
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Impedance Measurement Window
When the Impedance Measurement window (Figure 3-48) opens, Net Station initiates
a measurement of the contact impedance of each sensor. After performing a complete
set of measurements, Net Station updates the impedance values displayed in a list on
the right side of the window. The process repeats until the window is closed.
The Impedance Measurement window’s layout matches the sensor array being used.
In the display, red sensors are ones that have measured impedance values exceeding
the Threshold setting, and green sensors are ones at or below the Threshold setting
(see the next paragraph, “Impedance Measurement Window Controls”).
Progress bar
Figure 3-48. Example Impedance Measurement window
Impedance Measurement Window Controls
The All, Over, and Under buttons (Figure 3-49) and the user-editable Threshold text
box work in the following way:
• With the All setting, the list of impedance values displayed includes all the
sensors of the Net.
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• With the Over setting, the only sensor impedances displayed are those that
exceed the Threshold.
• With the Under setting, only those values under the Threshold are listed.
Orientation buttons
Figure 3-49. Impedance Measurement window controls
Next to the Threshold box is a checkbox that controls the speed and method of the
impedance measurement. With the checkbox unselected, Net Station measures
impedances one at a time. This method is most precise, but very slow. With the
checkbox selected, Net Station measures impedances for several channels at once,
speeding up the measurement process but sacrificing accuracy by reporting
impedances slightly
(10–15%) too high.
The pair of orientation buttons (Figure 3-49) changes the orientation of the sensor
layout.
The Show Labels checkbox hides or displays channel names.
To halt the impedance measurement process, use either the Close or Save & Close
buttons. Save & Close appends the most recent complete scan to the impedance
measurement sets in the History area of the Impedance Display panel (see page 79).
Impedance Measurement Method
Under Net Station supervision, the Net Amps drives certain sensors with a precision
20 Hz, 400 µV peak-to-peak sine wave signal. This level of voltage is above the level
of EEG but still results in extremely small current flows across the scalp.
Net Station measures the voltage at an undriven, passive sensor and calculates the
contact impedance.
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Experimental Control Status Panel
When the Experimental Control device is part of a Workbench configuration, saved
Acquisition Setup, or Session Template, the Experimental Control Status panel
(Figure 3-50) is available from the Panels menu (see “Panels” on page 88). For an
example Acquisition Setup containing an ECI device, see "Default Experimental
Control Setup" on page 98.
See Chapter 5, “Experimental Control,” in the EGI System Technical Manual for
detailed coverage of this panel.
Figure 3-50. Experimental Control Status showing Timeout pop-up menu
Menus
The menus presented on the Net Station menu bar are subject to change, depending
on what part of the application is being used.
Workbench Menu Bar
The menus connected with Workbench operations (Figure 3-51) are displayed only
when the Workbench is being used. The Record menu is available only when the
Workbench is on and disappears when the Workbench is off.
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The Acq menu is available only when the Workbench is being used but is displayed
whether the Workbench is on or off.
When Workbench is on
Figure 3-51. Workbench menu bar
Session Menu Bar
The Session menu bar is shown in Figure 3-52. The Record menu is always available
during a Session because initiating a Session automatically turns the Workbench on.
Figure 3-52. Session menu bar
Dense Waveform Display Menu Bar
When the Dense Waveform Display is the frontmost window onscreen, the menu bar
includes associated menus (Figure 3-53).
Workbench menu bar when DWD is frontmost window
Session menu bar when DWD is frontmost window
Figure 3-53. Dense Waveform Display menu bar
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File
The commands available in the File menu depend upon what part of Net Station is
being used, as shown in Figure 3-54.
Sidebar
Workbench
Ongoing session
Figure 3-54. File menu
• New: opens the New window with a list of choices for creating a new document
(Figure 3-55).
° Acquisition Setup causes a blank Workbench to appear.
° Session Template opens the Create New Session Template window.
° Session presents a list of existing templates for initiating a session.
Figure 3-55. New window showing correspondence to sidebar
• Open: opens an open file dialog. Note that if an Acquisition Setup is already
open, the open file dialog will not display Setup files.
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• Close/Close Window: closes either the current Acquisition Setup, with
autosaving, or the frontmost Dense Waveform Display window if one or more
DWDs are deployed.
This command and its corresponding default keyboard shortcut, z-W, have no
effect on palettes, which must be closed by clicking their close buttons.
• Save Acquisition Setup: saves the current Acquisition Setup. If the current setup
has not been saved previously, a dialog prompts for a name and location. This
command is not available when a session is under way.
• Save Acquisition Setup As: saves a copy of the current Acquisition Setup
document.
• Page Setup: not available in this version of Net Station.
• Print: not available in this version of Net Station.
• Quit: exits Net Station, closing sessions or recordings if they are under way and
closing Acquisition Setups if they are open.
Edit
The Edit menu operates on selected (highlighted) text or
alphanumeric fields. Some commands also operate on a
Workbench cell. When a field has not been selected, the
command operates on the field where the cursor has been
placed.
• Undo: not available.
• Cut: removes the selection and puts a copy of it on the
Clipboard.
Figure 3-56.E
dit menu
• Copy: copies to the Clipboard the contents of a
selection.
• Paste: pastes the contents of the Clipboard to a selected field.
• Clear: irreversibly deletes the contents of a selected field or Workbench cell.
• Select All: selects (highlights) all the text in any field where the cursor is placed
or where a partial or full selection of text is active.
• Unselect All: not available.
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Acq
This menu is called Acq after data acquisition. It is available only when the
Workbench is being used. The devices it presents match those of the Devices palette
(see “Devices Palette” on page 44).
• Turn On/Off Workbench: activates/deactivates the Workbench devices. You can
also turn the Workbench on or off by using the buttons on the right side of the
Acquisition Status panel just below the menu bar (Figure 3-1).
You can change a Workbench configuration only when the Workbench is off.
Device names are bold when a
Workbench cell has been selected.
Device names are dimmed when no
Workbench cells are selected.
Figure 3-57. Acq menu
• Hide Device Palette/Show Device Palette: toggles visibility of the Devices palette.
• Devices: selecting a device places it in the currently selected Workbench cell.
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Panels
The Panels menu provides access to the control
and display panels associated with devices that
belong to the current Workbench configuration
(when using the Workbench) or that are part of an
active Session Template. Info panels are included
in the list when Show Info Panels is checked.
When the Workbench is empty, only the Sort by
Name, Sort by Kind, Sort by Device, and Show
Info Panels commands are available.
Opening and Closing Panels
Device buttons
Open a panel by selecting it from the list. Close it
by clicking its close button. Panels are also
available through the device buttons on the
device itself.
This part of the menu
presents info, display, and
control panels that belong to
the current Workbench
configuration or Session
Template.
Clicking a panel name on
the extended menu deploys
the corresponding info,
display, or control panel.
Figure 3-58. Panels menu
• Iconize: any panel can be reversibly minimized to icon form by choosing Iconize
from the Panels menu. Double-clicking a minimized panel restores it to full
size. Iconizing control panels makes them readily available while reducing the
amount of screen space that they occupy (Figure 3-59). A reference to all the
panel icons is given in Appendix C, "Panels.
Double-click
panel to return it
to full size
Iconize
Full-sized panel
Iconized panel
Figure 3-59. Example of reversibly iconizing a panel
• Sort by Name, Kind, or Device: alters the order of the Device panels listed under
the Panels menu. The current sort order is indicated with a check mark.
• Show Info Panels: toggles the visibility of device info panels on the menu. Info
panels are also available via the device info panel buttons.
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Record
The Record menu does not appear in the menu bar unless a Waveform Recorder
Device is a part of the Workbench configuration and the Workbench is on.
(Workbench)
The New and Close buttons are functionally
equivalent to the New Recording and Close
Recording commands on the Workbench
Record menu.
(Session)
Figure 3-60. Record menu, Workbench, and Session variants
When you use a Session Template to initiate a new session, the Record menu is always
present but does not contain the New Recording and Close Recording commands.
This is because the Session Template automatically handles the naming and closing of
the file.
Each Record menu command is described below.
• New Recording: deploys the New Recording window (Figure 3-61) to create and
name a new Recording file.
• New Recording does not initiate recording; it only creates and names the file.
Use Record (Figure 3-62) to start recording.
• Close Recording: terminates recording and closes the Recording file.
• Record: starts recording. Functionally equivalent to the Record button (see
Figure 3-63).
• Stop: stops recording. Functionally equivalent to the Stop button (Figure 3-63).
• Show Big/Small Controls: toggles between normal-sized and small Waveform
Recorder Controls panel. Functionally equivalent to the anchor button
(Figure 3-14).
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Figure 3-61. New Recording window
Click Record
to initiate recording.
Figure 3-62. Clicking Record initiates Workbench recording
Big controls
Small controls
Figure 3-63. Big controls and small controls
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Display
The Display menu is used to manage multiple
DWD panels (Figure 3-64). It becomes available
when at least one Dense Waveform Display
(see Chapter 4) is deployed on the Workbench or
in a session.
Figure 3-64. Display menu
Multiple Dense Waveform Display Devices
The Workbench allows multiple DWD devices, each of which can have up to four
DWD windows.
• New Window: opens a new window for the frontmost DWD, up to four
windows per Workbench device.
• Tile, Arrange, Stack: rearranges the windows of the frontmost DWD in the
indicated arrangement.
• Reset All: causes the sweep lines of the frontmost DWD to reset to the leftmost
position.
Time
The DWD’s Time menu duplicates the functionality of the Time pop-up menu (see
“Scale Control Strip” on page 108) and controls the rate at which Net Station displays
EEG waveforms.
Time menu settings persist in Acquisition Setups. Opening an Acquisition Setup
restores the last setting used in that setup. Opening a Session Template restores the
settings of its embedded Acquisition Setup (see “The Embedded Acquisition Setup”
on page 117).
You can modify Time menu settings at any time, even during recording. The settings
apply only to the way the data are displayed; changes to the Time menu do not affect
the data recorded to disk.
Figure 3-65 displays the Time menu:
• Display Options: deploys the Time Display Options window.
• Actual Size (1/1): sets the waveform display to 1 sample/pixel.
• mm/sec and in/sec: sets units based upon screen distance.
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Figure 3-65. Time menu (default settings)
• ms/pixel and samples/pixel: sets units based upon screen pixels (see “Display
Method” on page 25).
• (preset values): configures time scale to common presets.
• Other: allows entry of custom values for time scale.
Amplitude
The DWD’s Amplitude menu commands
duplicate those of the Amplitude pop-up menu
(see “Scale Control Strip” on page 108).
Amplitude settings control the amount of vertical
displacement each waveform occupies in the
waveform display area of the Dense Waveform
Display.
Like the Time menu, the Amplitude menu
settings persist in Acquisition Setups. Opening
an Acquisition Setup restores the last setting used
in that setup. Opening a Session Template
restores the settings of its embedded Acquisition
Setup (see “The Embedded Acquisition Setup”
on page 117).
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This is a
shortened
version of
the menu.
The values
continue,
in varying
increments,
to 200.
Figure 3-66. Amplitude menu
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You can modify Amplitude menu settings at any time, even during recording. The
settings apply only to the way the data are displayed; settings made with the
Amplitude menu do not affect the data recorded to disk.
Figure 3-66 displays the Amplitude menu:
•
•
•
•
•
Actual Size (1:1): sets display to 1 µV/pixel.
µV/mm and µV/cm and µV/inch: sets units based upon screen distance.
µV/pixel: sets units based upon screen pixels (“Display Method” on page 25).
(preset values): configures amplitude scale to common presets.
Other: entry of custom values for amplitude scale.
Events
Using Net Station’s Dense Waveform Display (see
Chapter 4), EEG technicians and experimenters
can enter “mark” events into an EEG recording.
The events are called “mark” events after the
practice of manually marking the paper chart
recording to indicate the locations of significant
occurrences in the EEG.
The Events menu is one way to enter mark events
into a recording. It displays preset events and their
Figure 3-67. Events menu
corresponding keyboard shortcuts. While a
recording is in process, choosing one of the presets from the menu causes the preset
event to be entered into the marks event track of the recording.
The buttons on the Events control strip of the Dense Waveform Display perform the
same function.
The display of mark events in the Dense Waveform Display and the use of the Events
control strip are covered on page 110.
Help
• About Balloon Help: explains how to use
Balloon Help.
Figure 3-68. Help menu
• Show Balloons: activates Macintosh help
balloons to provide general window
information.
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Default Acquisition Setups
An Acquisition Setup is a means for saving a particular Workbench configuration
along with its device control and display panel settings (see “Acquisition Setup” on
page 37). You can create your own Acquisition Setups (see page 100) for data
acquisition using the Workbench and for embedding Session Templates. Net Station
provides three default Acquisition Setups:
• Primitive Acquisition Setup
• Typical Acquisition Setup
• Experimental Control Setup
Note: The default setups, unlike the user-created ones, can be used only for embedding
Session Templates (page 103), not for acquisition using the Workbench. Unlike usercreated setups, they are not double-clickable files and Net Station does not show a
pictorial representation of their Workbench configurations. However, they can be studied
by referring to the sections that follow. The names of the default setups are displayed in
the Select Session Template window (see Figure 5-1 on page 116) and in the Create New
Session Template window (see Figure 5-4 on page 120).
Workbench configurations and panel deployment schemes are described in the
following sections for each of the default setups.
Default Primitive Acquisition Setup
Primitive Acquisition Setup: Workbench Configuration
The Primitive Acquisition Setup uses a Workbench configuration consisting of the
Net Amps USB, Dense Waveform Display, and Waveform Recorder (WFR) connected
in series as shown in Figure 3-69. For details on these devices, see “Core Devices” on
page 46.
Figure 3-69. Device configuration of Primitive Acquisition Setup
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In this setup, the EEG cables pass through the DWD and are connected to the WFR
(Figure 3-70). Recorder and Display could be transposed with no change in the way
the EEG data are recorded, but this transposition would mean that user markups
made in the Display device would not propagate to the recording because the Display
would be downstream of the Recorder device.
Note: If user mark events are going to be part of a recording, always be sure that in the
Workbench configuration there is a MARK cable connecting the output of the Display
device to the input of the Recorder device.
Figure 3-70. Primitive Acquisition Setup
Primitive Acquisition Setup: Panel Deployment
When the Primitive Acquisition Setup was saved, the positions of panels were
preserved. The Dense Waveform Display was not deployed when the Acquisition
Setup was saved, so when the setup is opened, the DWD does not appear
automatically. You can select it from the Panels menu or via the Display button on its
corresponding Workbench device.
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Default Typical Acquisition Setup
Typical Acquisition Setup: Workbench Configuration
In the Typical Acquisition Setup, a Digital Filter (DF) and Bipolar Montage Editor
(BME) have been included in the Workbench configuration. EEG data are connected
both directly to the WFR and to the DF (Figure 3-71).
Digitally filtered data
Data flowing into the
Recorder have not
been digitally filtered.
Figure 3-71. Workbench configuration of Typical Acquisition Setup
This arrangement ensures that the data that enter the Recorder will not be modified
by digital filtering, yet filtered data can be visualized using the DWD.
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Panel Deployment of Typical Acquisition Setup
When the Typical Acquisition Setup (Figure 3-72) was saved, its control panels were
moved to the right side of the window, to allow the waveforms in the Dense
Waveform Display panel to be observed. The BME and DF control panels were
iconized and moved to the lower-left corner; they can be accessed by double-clicking
their respective icons.
Waveform display area of Dense
Waveform Display (see Chapter 4 for
details)
Figure 3-72. Panel deployment of Typical Acquisition Setup
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Default Experimental Control Setup
Experimental Control Setup: Workbench Configuration
The default Experimental Control Setup is identical to the Typical Acquisition Setup,
save for the addition of the Experimental Control Interface device and its connection
via the STIM cable.
Figure 3-73. Workbench configuration of Experimental Control Setup
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Experimental Control Setup: Panel Deployment
The panel deployment scheme for the Experimental Control Setup is the same as that
of the Typical Acquisition Setup, except for the inclusion of an iconized Experimental
Control Status Panel. You can access it by double-clicking its icon in the lower-left
corner of the screen, or by choosing it from the Panels menu.
Figure 3-74. Panel Deployment of Experimental Control Setup
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Creating New Acquisition Setups
You can create your own Acquisition Setup files by opening the Workbench,
configuring devices, making panel settings, and then saving their creation to disk.
The editable files that result from this process are saved by Net Station to the
Acquisition Setups folder by default (see “Acquisition Setups Folder” on page 33).
The destination folder can be overridden in the Save dialog—clicking the Destination
button (Figure 3-75) provides a file navigation window.
Destination
button
Figure 3-75. Default Save dialog for saving Acquisition Setups
Constructing an Acquisition Setup involves placing and connecting devices on the
Workbench (see “Placing and Connecting Devices” on page 45), deciding which
panels to deploy, then saving the setup as an Acquisition Setup file (see “File” on
page 85).
The examples in this section demonstrate features of Workbench configurations that
you should be aware of if you choose to design your own Acquisition Setups.
Figure 3-76 shows a Workbench configuration that is identical to the default Primitive
Acquisition Setup, but in which the STIM cable has been reconfigured to bypass the
Display device. There is no particular reason to do this except to illustrate a point: In
this setup, any digital input events captured by the Net Amps USB device will be
recorded by the WFR, but will not be displayed in the DWD. In this situation, the
digital input tracks in the DWD would remain blank even though the events would
be written to the data file.
Figure 3-76. Recording but not displaying digital inputs
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Note: PAT and STIM connections have been omitted from the following dual DWD
configurations for the purpose of illustration.
The next example configuration demonstrates one way to properly connect the Digital
Filter device. As discussed in “Digital Filter Controls” on page 50, the IIR filter of the
real-time Digital Filter device is not appropriate for transforming data, only for
visualizing it. It follows that it is not correct to connect a Digital Filter ahead of the
Recorder device. In the configuration of Figure 3-77, the Filter device is not connected
in series with the Recorder.
Also demonstrated in Figure 3-77 is the way that more than one Display device can
occupy the same configuration. Clicking the Display buttons on both devices results
in two Dense Waveform Displays opening, one for each device. Users can resize and
position the two display windows next to each other onscreen, then manipulate the
Digital Filter controls. In so doing, the effect of the IIR filter will be immediately
observed in DWD[1] and can be compared with the unfiltered data viewable in
DWD[2].
Figure 3-77. Correct connection of filter device, no events
It might be imagined that user mark events could be implemented in this
configuration by connecting the MARK jack on the output side of DWD[2] to the
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MARK jack on the input side of the WFR (Figure 3-78), but this is an invalid
configuration.
Figure 3-78. Example of a cable loop (invalid configuration)
It is invalid because it contains a cable loop. The same device cannot both receive
input from a device and send output to the same device, which is exactly what the
DWD[2] device is doing. It is receiving input from the WFR device and also
attempting to send mark events to the WFR device.
A different way to bring user mark events into the recording is implemented with the
configuration shown in Figure 3-79. It does not violate the looping rule and it works.
Figure 3-79. A correct dual-DWD configuration with mark events
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A simpler way to implement this functionality is shown in Figure 3-80, where the
positions of DWD[2] and the WFR have been transposed.
Figure 3-80. Reconfiguring for a simpler configuration
Session Templates Use Acquisition Setups
As shown in Figure 5-3 on page 118, Acquisition Setups are embedded in Session
Templates. In particular, the default setups—Primitive Acquisition Setup, Typical
Acquisition Setup, and Experimental Control Setup—are always available for
embedding in a new Session Template. User-created setups will also be available, so
long as they are saved to the appropriate location and contain the required devices.
Note: Workbench configurations that do not contain a Source device, or lack either the
DWD device or Waveform Recorder device can be saved in Acquisition Setup files, just
like any other configuration. However, Net Station will not display such files in the Create
New Session Template window. Such setups cannot be embedded in a Session Template
because Net Station regards them as fundamentally incomplete.
Because creating a Session Template does not involve the Workbench, it is not covered
in this chapter. See Chapter 5 for coverage of Session Templates and how Acquisition
Setups are a part of every Session Template. See page 117 for an example of how to
embed an Acquisition Setup in a Session Template. See page 119 for how to create a
Session Template and how to use it to acquire data.
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3: The Workbench
Final Note
With an Acquisition Setup, screen locations of the control and display panels and their
iconization states are remembered by Net Station. A reopened Acquisition Setup file
will contain devices and device panels in the state they were in when the file was
closed.
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chapter 4
CHAPTER
4
DENSE WAVEFORM
DISPLAY
Introduction
Dense Waveform Display (Figure 4-1) provides a way to view real-time EEG
T hewaveforms
and events. In addition, the DWD is an input interface for technician
markup events that can be entered and recorded along with the EEG.
See Figure 4-2 for the structure of the DWD. See the sections following the figure and
its numbered list for a part-by-part treatment of DWD functionality.
When using the Workbench, click the
Display button on the DWD device to
make the DWD appear.
When conducting a session, choose the
DWD from the Panels menu.
Figure 4-1. Invoking the Dense Waveform Display
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4: Dense Waveform Display
*16
*15
Close button
1
2
3
4
14
13
5
6
7
12
Waveform area
8
11
9
10
Figure 4-2. Example Dense Waveform Display
The following are labels for the numbered items in Figure 4-2.
1. Upper control strip
2. Scale control strip
3. Time control strip
4. Events control strip
5. Tracks area
6. Waveform Options control strip
7. Sweep line
8. Channel tiles
9. *Montage Controls panel (iconized)
10. *Waveform Recorder controls (iconized)
11. Size box (resize the DWD by dragging)
12. Scroll bar
13. Pause button
14. Reset button
15. *Advanced Net Amps Controls (collapsed)
16. *Net Amps Controls (collapsed)
The asterisked items (*) indicate panels that are not part of the DWD. When deployed, the
panels float above the display. They are shown here to illustrate this behavior.
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Menus and Acquisition Status Panel
When the DWD is frontmost, menus that are specific to its functions are available in
Net Station’s menu bar. For coverage of these DWD-specific menus, see “Dense
Waveform Display Menu Bar” on page 84.
The DWD also includes pop-up menus (Figure 4-3).
This type of menu occurs on the Scale control strip
(see page 108). To open a pop-up menu, position the
cursor over it and press the mouse button.
Figure 4-3. Pop-up menus
The Acquisition status panel is always present just below the main menus (see
page 128 for coverage of the Acquisition status panel when using a Session Template;
see page 39 for the Acquisition status panel when doing Workbench recording).
Upper Control Strip
Various functional areas of the DWD can be either hidden or displayed using the
Scale, Time, and Events buttons on the left side of the upper control strip. Toggling
these buttons has no effect on the settings of their corresponding functional areas,
only on visibility. Figure 4-2 shows the Scale control strip, Time control strip, Events
control strip, and Tracks area in their visible states. The corresponding buttons on the
upper control strip have a “pushed-in” appearance to indicate that visibility is set for
all of them.
Note: The Events button toggles the visibility of both the Events control strip and the
Tracks area.
Pause and Reset Buttons
On the right side of the upper control strip are the Pause and Reset buttons. Toggle the
Pause button to halt the sweep line (page 113)—momentarily freezing the scene in the
waveform area—or to restart the sweep line from a paused state. The Pause button
works with recording on or off. Elapsing time on the Acquisition status panel
continues to update during a pause.
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The Pause button does not halt recording or prevent the
entry of technician mark events; it only freezes the real-time
display of waveforms.
After you resume the display of waveforms, a pause line
(Figure 4-4) will be visible in the DWD in the position where
the pause took place. It indicates a discontinuity in the
displayed data.
Figure 4-4. Pause line
Technician mark events can be entered during the paused state and will become a
part of the data file if recording is on. Such events will not be placed in the recording
at the point of the pause, but rather at the time in the recording when you clicked the
mark event button.
Note: Mark events entered during a pause do not show up in the marks track during realtime display. However, they are entered in the recording. Also, the size box and scroll bar
cannot be used during a pause without erasing the Waveform area. Data and events being
recorded are not affected, and normal sweeping is restored when the Pause button is
toggled off.
Click the Reset button to cause the sweep line to relocate to the leftmost part of the
waveform display area and recommence sweeping from that position.
Buttons affect only the display window to which they belong. To reset all multiple
DWD sweep lines in a single operation, use the Reset All command from the Display
menu (see page 91).
Scale Control Strip
The Scale control strip (Figure 4-5) contains controls for customizing the way that
waveforms appear in the DWD waveform area. (The controls provided by the Scale
control strip are also available via menus [see “Time” on page 91 and “Amplitude” on
page 92].)
To display the Scale control strip, click the Scale button on the upper control strip.
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1
2
3
4
5
6
7
Figure 4-5. Scale control strip
The following are brief descriptions of the numbered items from Figure 4-5.
1. Time Scale 1:1 button. Sets the waveform display to 1 sample per pixel on the
horizontal (X) axis of the screen.
2. Time Scale Decrease/Increase buttons. Change the time scale (left button decreases,
right button increases) incrementally.
3. Time Scale pop-up menus. Set the value and units for the horizontal axis.
4. Amplitude Scale 1:1 button. Sets the waveform display to 1 µV/pixel on the
vertical (Y) axis of the screen.
5. Amplitude Scale Decrease/Increase buttons. Resize the waveform amplitudes (left
button decreases, right button increases) incrementally.
6. Amplitude Scale pop-up menus. Set the value and units for the vertical axis.
7. Polarity buttons. Toggle between displaying the waveforms with positive up or
positive down. Data being recorded are unaffected.
Whatever settings are in effect apply to all waveforms of the DWD.
Time Control Strip
The Time control strip (Figure 4-6) features a time-mode button that opens the Time
Display Options panel. Setting the time display options is covered in “Time” on page
91, which includes a picture (Figure 3-65) of the Time Display Options panel.
The Time Menu Display Options command from the Time menu duplicates the
functionality of the time-mode button.
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Elapsed time (in one of four time modes; see Table 3-4 on page 57) is displayed in the
box to the right of the time-mode button.
The time-mode button
opens the Time Display
Options panel
Elapsed time
Time ruler
Figure 4-6. Time control strip
Time Ruler
The sweep line (Figure 4-2, label 7) passes through the time ruler portion of the Time
control strip in synch with its passage through the waveform area, indicating the time
of the current sample.
Events Control Strip
The left side of the Events control strip (Figure 4-7) features three toggle buttons for
hiding or displaying their corresponding tracks: Marks, Calibration, and DIN/ECI
(see “Tracks Area” on page 111).
Marks
Calibration
DIN/ECI
Figure 4-7. Events control strip
The rest of this control strip contains a series of buttons for adding user mark events
to a recording. Clicking a button causes a corresponding user mark event to be added
to the file at that point in the recording. The mark event is displayed in the Tracks area
in the form of a flag bearing the name of the mark event.
Note: The default Acquisition Setups use Workbench configurations that are designed to
capture user mark events to the recording and to the DWD, but it is possible to construct
Workbench configurations where mark events will not be recorded or not displayed, or
both. Refer to the examples in “Default Acquisition Setups” on page 94.
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Tracks Area
The sweep line passes through the Tracks area (Figure 4-8) in synch with its passage
through the waveform area and time ruler. Each track is labeled according to the type
of event it can store and display. For example, if you are using a Session Template that
automatically performs calibration, you will see calibration events registering in the
Calibration track when the session begins.
Figure 4-8. Tracks area with Events control strip
By using the Digital Inputs Controls panel (see page 62), you can specify up to eight
DIN tracks and customize the DIN track labels. The Net Station default is to have all
DIN events record to the track labeled DIN1 (Figure 4-8). A DIN event registering in
the track has the form of a miniature flag(
).
ECI events display in the ECI track when experimental control is being used. When
you click a button in the Events control strip, a new mark event appears in the form of
a flag in the Marks track, and a corresponding event appears in the recording. For an
example, see the rightmost portion of the Tracks area in Figure 4-2, where a
“Comment” flag is visible in the Marks track. In this instance, the user clicked the
“comm” button to produce the Comment event.
The button labels are abbreviations for various phenomena that you will encounter
while recording EEG. The abbreviations are decoded in Table 4-1.
Table 4-1. Mark events
Button label
Mark event type
eyeb
eyeblink artifact
eyem
eye movement artifact
badc
bad channel
bads
bad segment
comm
comment
moto
motion artifact
emg
electromuscular artifact
noise
noise artifact
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The Events menu duplicates the functionality of the buttons and adds a special Insert
Comment command that deploys a Comment text window. You can type a comment
into this window; when you click the Insert button in the window, a Comment event
will be registered into the Marks track at the then-current position of the sweep line.
Note: Net Station registers and records events in real time with millisecond accuracy, and
their placement in the tracks vis-a-vis the time ruler is precise. But the moment the event
flag appears in a track of the DWD may not always precisely match the moment the event
was generated in real time. This imprecision applies only to the real-time display of the
event flags, not to the recording of the events and their position with respect to the time
ruler in the DWD.
Waveform Options Control Strip
The Waveform Options control strip is always deployed.
This control strip (Figure 4-9) carries buttons for changing channel spacing and
toggling the waveform area grid on and off. You can also change the channel spacing
by dragging the boundary of a channel tile (see page 114).
Note: The rightmost of the three Channel Resize buttons will not be available if the
channels in the current montage are so numerous that all of them cannot fit in the
window.
The “eye” icon is the Channel Visibility label indicating the column of visibility
buttons on the channel tiles (see page 113).
Also displayed in the Waveform Options control strip are
• the current hardware filters in effect, with their cut-off frequencies
• the name of the current montage
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Note: If an ellipsis (...) appears in the filter or montage notifications, it means that there is
not enough room to display a complete notification. Moving the cursor over the
notification causes the complete text to be momentarily displayed.
Channel Resize
buttons
Channel Visibility label
Grid toggle button
Figure 4-9. Waveform Options control strip
Sweep Line
The red line moving from left to right in the waveform area of the DWD window is
the sweep line. It traverses the time ruler (page 110) and Tracks area (page 111) in
synch with its traversal of the waveform area, and it indicates the current time, event,
and sample.
Sweep Line Interruption
Under some circumstances, the sweep line pauses momentarily while data are being
written to disk, then resumes sweeping. This interruption in sweeping is not a cause
for concern.
Channel Tiles
The channel tiles are always visible on the left side of the DWD. Each channel tile is
labeled with a channel name and carries a signal originating from one of the densearray sensors of the Geodesic Sensor Net. Different sensor layouts have different
numbering/naming schemes and Nets are available with differing densities, so the
tile labels may differ from the example.
Visibility button
Clicking the Visibility button on a channel tile toggles between hiding and displaying
the waveform of that channel.
Clicking a channel tile outside the Channel Visibility button causes the waveform of
that channel to be displayed in red. Use this to differentiate overlapping waveforms.
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Figure 4-10. Numbered channel tile label example
Toggle a selected channel tile to return the waveform to its default color. Multiple
channel tiles can be toggled to display their waveforms in red.
Resizing Channel Tiles
You can resize channel tiles to their minimum and maximum heights by using the
Channel Resize buttons (see “Waveform Options Control Strip” on page 112). You can
set channel tiles to heights intermediate between maximum and minimum by
dragging. Bring the cursor over the boundary of any of the channel tiles and the
cursor changes into the resize cursor. Dragging the resized cursor causes all the
channel tiles to resize.
Size Box
Use the window size box to change, by dragging, the size of the entire DWD window.
Waveform Area
EEG waveforms are displayed in the waveform area. Use the controls on the Scale
control strip (page 108) to customize how the waveforms are displayed. Use the scroll
bar on the right side of the DWD to browse the waveform area when the window is so
small, or the channel spacing so large, that not all the channels will fit in the window.
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chapter 5
CHAPTER
5
SESSIONS AND
SESSION TEMPLATES
Net Station Session
A
Net Station session is an EEG data-acquisition procedure that requires the use of
a Session Template. The result of such a session is a Session file containing a
recording of dense-array EEG along with (optionally) user mark events and external
digital input events that occurred simultaneously with the EEG. In addition, the
Session file can store along with the EEG and events a wide range of metadata such as
subject name and subject traits.
Session Templates contain embedded Acquisition Setups and may also contain
editable metadata fields. Depending on how the Session Template was configured, a
session can include automatic amplifier calibration and impedance measurements,
and automated naming of the output Session file. The idea is to make the EEG data
acquisition process as streamlined, repeatable, and automatic as possible.
Net Station comes with a number of default Session Templates based on the default
Acquisition Setups described in “Default Acquisition Setups” on page 94.
Once created, a Session Template cannot be edited. You can conduct repeated data
acquisition sessions that always have the same parameters, by using a Session
Template.
The flowchart in Figure 5-1 shows the basic process of starting a new session using a
Session Template. For details, see “How to Use A Session Template” on page 123.
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Metadata fields
The new session begins, governed by the definitions and protocols contained
in the Session Template, e.g., the embedded Acquisition Setup.
Figure 5-1. Flowchart for initiating a session
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Session Template Components
A Session Template has some required and some optional components (see Figure 5-2,
“Anatomy of a Session Template”).
Session Template components
Required
Template name
Embedded Acquisition Setup
Output file naming and destination definition
Optional
Session database definition (metadata fields)
Amplifier calibration protocol
Sensor impedance measurement protocol
Figure 5-2. Anatomy of a Session Template
Name
The Session Template name is simply the file name in the Finder and can be altered
later.
The Embedded Acquisition Setup
When a Session Template is created (see “How to Create a Session Template” on page
119), a particular Acquisition Setup is copied into it. This process is called embedding
the Acquisition Setup. The original Acquisition Setup is not altered by this process
and remains an editable document. But the copy that becomes part of the Session
Template is no longer editable (Figure 5-3).
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Saved
Acquisition
Setup
Embedding the Acquisition Setup in a
new Session Template
Copy of saved
Acquisition
Setup
Session
Template
Saving...
Copy of saved
Acquisition
Setup
Session
Template
Figure 5-3. Embedding an Acquisition Setup in a Session Template
Output File Naming and Destination Definition
Session files generated during a session must be named and placed in a destination
folder. When the Session Template is created, automatic naming and destination
conventions are specified. The file name and destination are governed by the
specification of the template, although you can override the specification later during
the initiation of the session.
Metadata Fields
A Session Template may optionally include metadata fields. The default Session
Templates include a built-in set of metadata fields. You can create your own templates
with preexisting metadata fields or create and incorporate new fields. The fields and
the metadata they contain become part of the Session file when it is saved.
Information can be entered into fields during a session, but the presence or absence of
fields cannot be changed.
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Other Session Template Options
Two additional options are available when defining a Session Template. When either
of these options is chosen, Net Station automatically performs the specified
operations during startup of the session:
• amplifier calibration (gains and zeros measurement)
• sensor impedance measurement
After Net Station completes the operations, if any were specified, the session is then
governed by the embedded Acquisition Setup and your interaction with it.
Note: Sensor impedance measurements can be collected only with a Net attached to the
System.
On sidebar,
start here
How to Create a Session Template
To begin, launch Net Station and click the Session Template button on the sidebar.
This opens the Create New Session Template window (Figure 5-4).
The Create New Session Template window is divided into five areas. Refer to the
figure as you read the next sections, to go over a step-by-step description of how to
create a template.
1 Choose a template name. The Save Session Template button will not activate if
the field is empty.
2 Click the name of the Acquisition Setup to be embedded (copied) into the
Session Template.
3 Choose which operations to perform at the start of the session:
° Calibrate Amplifier: measures the gains and zeros for each of the individual
amplifier channels. For the most accurate measure of amplifier
characteristics, you should not connect the GSN during these measurements,
because it can interfere with calibration.
° Check Impedance: initiates measurement of impedance at each sensor. To
check for sensors that might be in poor contact with the subject’s scalp, apply
the Net to the subject before initiating the impedance check.
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5: Sessions and Session Templates
4
1
2
3
5
Figure 5-4. Create New Session Template window
4 Select the metadata fields to include with each session. This area is initially
blank and can remain so if you do not want to include metadata fields in a
session. Whatever fields are added here will appear at the start of the session,
prompting you to input metadata.
Click the Insert button to deploy the Insert Fields window (Figure 5-5).
Choosing fields in the Insert Fields window and clicking Insert will add them
to the Session Template. See Figure 5-12 for an example session that contains
metadata fields.
5 Select session-naming and destination options. The text box beneath the
Destination pop-up menu shows the resulting name and destination.
After completing these steps, click the Save Session Template button. See Figure 5-7
on page 122 for an example of a completed Session Template.
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Insert Fields Window
Add metadata fields to a Session Template by selecting a field in the Insert Fields
window (Figure 5-5) and clicking the Insert button at the bottom of the window. The
standard fields are not editable, but you can create custom fields that can be edited.
Figure 5-5. Insert Fields window
To add a custom field, click the New Field button. This produces the Create New Field
window (Figure 5-6), with a text box for entering the field name. Specify the field type
using the Field Type pop-up menu (Figure 5-6), which defaults to Alphanumeric.
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Figure 5-6. Create New Field window with Field Type pop-up menu
Figure 5-7. Example of a completed Session Template
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Start here
How to Use A Session Template
To begin a session, click the Session button in the Net Station sidebar. The Select
Session Template window opens, offering a choice of Session Templates (Figure 5-8).
Any user-created templates located in the Templates folder (see page 34 for
information about this folder) will be listed, in addition to the default templates.
The default templates will always appear first in the list, sorted alphabetically. User
templates in the Templates folder will be listed next. User templates can have the
same names as the default templates, but this is not a wise way to name your custom
templates.
Figure 5-8. Select Session Template window with Experimental Control Template selected
There are three ways to choose one of the available Session Templates from the Select
Session Template window:
• Double-click a Session Template list item
• Single-click a Session Template list item, then click the Select button
• Single-click a Session Template list item, then press the Return key on the
keyboard
All three ways have the same result—opening the Enter Session Information window
(see “Session Information,” the next section).
Note: You can double-click user-created templates directly in the Finder to begin a session,
whether Net Station has already been launched or not. If Net Station is inactive when you
double-click a Session Template, Net Station will automatically launch and the Session
Information window will open. Using this method of initiating a session bypasses the
Select Session Template window.
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Session Information
After you pick a Session Template, the Enter Session Information window appears,
displaying in its Session Information subpanel the metadata fields and buttons that
were specified when the template was originally created. You can enter session
information at this point, or do so later in the session. Whatever metadata are entered
will automatically become a permanent part of the Session file after it has been saved.
Figure 5-9 shows the Enter Session Information window defined in the default
templates.
Figure 5-9. Enter Session Information window included with the default templates
Identify Subject Subpanel
Subject identifiers do not store metadata; they are simply labels. If subject identifiers
have been created in previous sessions, they will appear in the Identify Subject
subpanel of the Enter Session Information window. Net Station stores previously
created subject identifiers in its Resource Database (see “Support Folder” on page 34).
New subject identifiers are created by typing into the box to the left of the list.
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Session File Naming and Destination Scheme
When you create a new Session Template, you can choose from two autonaming
schemes (for details, see page 120). In the case of the default Typical Session Template,
the option was set to automatically name the Session file using the subject name and
current date and time.
Figure 5-10. Autonaming for default Typical Session Template
The lower part of the Enter Session Information window (Figure 5-10) displays the
name that will be applied automatically to the Session file when you close the session
and save the file. This particular scheme constructs the session name by appending a
date and time code to the user-chosen subject identifier (or the default, if there are no
others). The date-time code is of the form: yyyymmdd hour.minute.
Note that you can click the Begin Session button at any time during this part of the
setup for a session, but once you click the Begin Session button, you cannot change
the file name and destination folder. The Session file can always be renamed and
moved using the Finder after the session.
You can override the Template’s built-in naming scheme, destination setting, or both
using the Rename Session window, described in the following paragraphs.
If you click the Rename Session button
in the Enter Session Information
window, a window is displayed for
overriding the default session name
(Figure 5-11). You can navigate to a
destination folder as well as enter a new
name for the session. With the
navigation feature, you can override the
Session Template’s destination scheme,
which is also defined when the Template
is saved.
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Figure 5-11. Rename Session window
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5: Sessions and Session Templates
Click the New button in the Rename Session window to save the new name and
destination and return to the Enter Session Information window, or click the Cancel
button to accept the built-in naming scheme. Once you click the New button, the
destination that was displayed in the window becomes the new destination,
overriding the Session Template’s built-in specification.
If you have renamed the session, the new name will appear in the lower part of the
Enter Session Information window.
An example default Enter Session Information window with Experiment Name and
Experimenter Name fields filled out is shown in Figure 5-12.
Figure 5-12. Session information has been entered
Automatic Amplifier Calibration
With the default Typical Session Template,
automatic amplifier calibration is performed. The
gains and zeros progress bars come up in tandem
(Figure 5-13).
Note: For the most accurate measurement of amplifier
gains and zeros during calibration, do not connect a
sensor array.
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Figure 5-13. During
amplifier calibration
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When the measurement of gains and zeros is finished, the progress bars disappear
from the screen.
Impedance Measurement
If you create a Session Template with the
Check Impedance checkbox selected
(see page 119), impedance measurement is
automatically performed when you
initiate the session. If not, you must
manually initiate impedance measurement
(Figure 5-14).
Before a sensor impedance measurement
begins, connect a sensor array to the
System and apply it to the subject.
Figure 5-14. Click the Measure Net
Impedance buttons
If an impedance measurement is initiated without a sensor array connected,
Net Station issues an error. Otherwise, the Impedance Measurement window appears,
displaying a sensor layout that matches the layout of the attached sensor array (see
Figure 5-15).
Figure 5-15. Impedance Measurement window (EGI’s 256-channel Net)
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Adjust sensors so that impedances are acceptable, then click the Save & Close button
to save the current measurement set (see “Impedance Measurement Window” on
page 81).
Recording EEG
Click the Record button on the Waveform Recorder Controls panel and note that the
Acquisition status panel displays an indicator that recording is in progress.
Click the Stop button to end the epoch of EEG being recorded. Click Record again to
begin a new epoch.
Closing the Session
Clicking the Close Session button ends the recording and closes the Session file,
naming and placing the file in a directory per the Session Template specification (or
the user override, if any).
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appendix A
APPENDIX
HASP key
A
UPDATING
EGI LICENSES
EGI protects its software from unauthorized use by encoding licensing data in HASP
keys. If you have purchased a complete EGI EEG System, the HASP key is attached to
the system cart handle. If you have purchased only the Net Station software, the key is
included in the software installation package.
A HASP key is a small hardware device (sometimes called a dongle) that you plug into
a computer’s USB port. The information in the HASP key tells Net Station whether
you are allowed to use the software.
All authorized Net Station users have a HASP key. To update your EGI license, do not
send EGI the actual hardware key. Instead, you will need to generate a computer file
from the HASP key and email the file to EGI, which will update the licensing
information in the file and email it back to you. Use the edited HASP file to update
your software. (See Figure A-1.)
Figure A-2 lists some points to keep in mind before you begin the HASP key–updating
process. Step-by-step instructions for updating EGI licenses follow the tips.
1
Generate an
Update file from
your HASP key.
Success!
2
Compress the file
and email it
to EGI.
3
EGI will update
the file and email
it to you.
4
Uncompress the
Updated file and
use it to update
your HASP key.
Figure A-1. Overview of the license-updating process
Net Station Acquisition Technical Manual
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129
A: Updating EGI Licenses
Tips on Updating EGI Licenses
File compression. Before emailing
your Update file to EGI, compress the
file using a software program such as
NutCase Binhex or StuffIt (with the
Binhex option on) to safeguard against
file corruption during the email
process.
Unique HASPs. Updated HASP files
are unique to their individual HASP
keys. The HASP key that created the
Update file must be plugged in when
the Updated file from EGI is applied to
update the license. Note: You may
have multiple HASP keys with the
same name, followed by a number.
The number of the HASP key must
match the number of the Update file
when updating.
HASP names. To determine which
HASP key is which, launch Net Station.
The name of the HASP key is in the
bottom-left of the Net Station start-up
screen. Quit Net Station, launch the
Updater application, and apply the
corresponding HASP file.
File organization. Avoid duplicate
Update files. After emailing your
Update file to EGI, delete it from your
computer. Likewise, after applying the
Updated file from EGI to your HASP
key, delete the file.
Figure A-2. HASP-updating tips
130
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A: Updating EGI Licenses
Opening the Updater Application
1 Quit Net Station, if necessary.
2 Insert the HASP key into the USB port at the side of your keyboard or at the back
of your computer. A light should illuminate within the key.
3 On your hard drive,
open the Applications
folder.
4 Open the Net Station install
folder in the Applications folder.
5 Open the Extras folder and
double-click on the NS
Remote HASP Updater icon to
launch the application and
open the Updater dialog.
Figure A-3. Open the HASP Updater application
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A: Updating EGI Licenses
Generating the Update File
1 Make sure that the
Create Update File tab is
frontmost in the Updater
dialog.
2 Click the HASP
file button.
3 The Update dialog will automatically close, and an Update
file will appear on your Desktop with the filename “NS –
xxxx,” where xxxx is the license holder’s name. If you have
more than one HASP, the number of the HASP will be
appended (e.g., NS - Ling Chan, NS - Ling Chan 1).
4 Compress the file using a software program such as NutCase Binhex
(www.blackdiamond.co.za/bdfreex.html) or StuffIt, with the Binhex option
on (www.stuffit.com/mac/standard). This will ensure that your file is not
corrupted in transit. Note that this operation must be performed on a
Macintosh computer, not a PC.
5 Email the compressed file to
support@egi.com and include in the email
message your name, the license holder’s
name (if you are not the licensee), your
organization, and a
description of what
must be updated.
For best results, email
the file from the Macintosh computer that
generated it. Or, you can copy the file to a
Mac HFS-formatted removable drive, transfer
it to another Mac, and email it. Do not email it
from a PC.
6 Delete the HASP
Update file and any
previous compressed
copies from your
Desktop.
7 EGI will modify the file, updating
your license, and email it back to you,
typically within two to three days.
Figure A-4. Create the HASP Update file, compress it, and email it to EGI
132
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A: Updating EGI Licenses
Applying an Updated File
1 Save to the Desktop the Updated file from EGI, uncompressing it if needed.
2 Quit Net Station, if necessary.
3 Insert the corresponding HASP key into the USB port at the side of your
keyboard or at the back of your computer. A light should illuminate within the key.
4 Open the Net Station install folder in the Applications folder on your hard drive.
5 Double-click on the NS Remote HASP Updater icon, which will open the
Updater dialog.
6 Make sure that the
Update HASP tab is
frontmost in the Updater
dialog.
7 Drag the Updated file
into the Update box.
8 A dialog will appear, with
a message indicating a
successful update.
9 Delete the Updated
file and any compressed
copies from your
Desktop.
Figure A-5. Apply the Updated file from EGI to the corresponding HASP
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A: Updating EGI Licenses
Questions
Contact EGI at support@egi.com with any questions regarding this document and the
issues discussed.
134
Net Station Acquisition Technical Manual
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appendix B
APPENDIX
B
SOFTWARE
TECHNICAL SUPPORT
Before Contacting EGI
Please check the Contents on page v and
the Index on page 161 for coverage of
your issue or question. You can also
perform an electronic search using Find
or Search in the PDF version of this
manual posted on the Documents page
of the EGI website (www.egi.com/
documentation.html).
In addition, the Support page of the EGI
website (www.egi.com/support.html)
may have the information you need.
Contacting EGI
EGI Support
web page
www.egi.com/
support.html
Email support
support@egi.com
Sales
information
info@egi.com
Telephone
+541-687-7962
Fax
+541-687-7963
Address
Electrical Geodesics, Inc.
1600 Millrace Drive
Suite 307
If you need more help, EGI recommends
the following:
Eugene, OR 97403
USA
• Try to isolate the problem. Is your
problem well defined and repeatable?
• Document the problem. Carefully
record and organize the details gleaned
from the above step and report the
problem to EGI.
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135
B: Software Technical Support
136
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appendix C
APPENDIX
C
PANELS
Info, display, and control panels associated with Net Station devices can be
individually iconized using the Iconize command of the Panels menu or its equivalent
keyboard shortcut, z-/. In a session or the Workbench, the icons will appear to hover
over the Dense Waveform Display, and you can move them onscreen by dragging.
Double-clicking icons reinflates their panels to full size. Table C-1 shows the
appearance of the Panel icons and provides page references where the corresponding
panels are described.
Table C-1. Panel icon reference
Panel icon
Dense
Waveform
Display
Digital Filter
Bipolar
Montage Editor
Net Station Acquisition Technical Manual
Panel name
Reference
Dense Waveform Display Info
Page 49
Dense Waveform Display
Chapter 4, starting on
page 105
Digital Filter Info
Page 49
Digital Filter Controls
Starting on page 50
Bipolar Montage Editor Info
Page 49
Montage Controls
Starting on page 53
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C: Panels
Table C-1. Panel icon reference
Panel icon
Waveform
Recorder
Net Amps USB
Panels
Experimental
Control
Interface
138
Panel name
Reference
Waveform Recorder Info
Page 49
Waveform Recorder Controls
Starting on page 54
Net Amps USB Info
Page 49
Net Amps Controls
Starting on page 58
Advanced Net Amps Controls
Page 62
Digital Input Controls
Starting on page 62
Amp Diagnostics
Page 72
Zeros
Starting on page 75
Gains
Starting on page 75
Noise
Starting on page 76
Impedance
Starting on page 79
Experimental Control Interface
page 83
Experimental Control Status
Chapter 6 of the
EGI System
Technical Manual
Net Station Acquisition Technical Manual
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appendix D
APPENDIX
D
MONTAGES
The following tables list the Net Station default montages, their referencing schemes,
and page locations for sensor map views. A montage affects the display of EEG
waveforms, not the way they are recorded. In a number of cases, the sensor maps
indicate which sensors’ data are displayed in the DWD, and which are not, for a given
montage. For how to apply a montage during data acquisition, see the “Montage
Controls” section in Chapter 3.
Table D-1. 256-channel montages
Montage
Referencing scheme
Figure on page
GSN 256 Adult 2.0
vertex
n/a
Average Reference
average of all sensors
n/a
10-20
average of all sensors
Figure H-1, page 140
Double Banana
bipolar
Figure H-4, page 142
Eyes
vertex
Figure H-7, page 143
Left Mastoid Reference
sensor 93
Figure H-10, page 145
Linked Mastoid Reference
sensors 93 and 191
Figure H-13, page 146
Right Mastoid Reference
sensor 191
Figure H-16, page 148
Table D-2. 128-channel montages
Montage
Referencing scheme
Figure on page
GSN 128 Adult 1.0
vertex
n/a
Average Reference
average of all sensors
n/a
10-20
average of all sensors
Figure H-2, page 141
Double Banana
bipolar
Figure H-5, page 142
Eyes
vertex
Figure H-8, page 144
Left Mastoid Reference
sensor 57
Figure H-11, page 145
Linked Mastoid Reference
sensors 57 & 101
Figure H-14, page 147
Right Mastoid Reference
sensor 101
Figure H-17, page 148
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139
D: Montages
Table D-3. 64-channel montages
Montage
Referencing scheme
Figure on page
GSN 64 Adult 2.0
vertex
n/a
Average Reference
average of all sensors
n/a
10-20
average of all sensors
Figure H-3, page 141
Double Banana
bipolar
Figure H-6, page 143
Eyes
vertex
Figure H-9, page 144
Left Mastoid Reference
sensor 26
Figure H-12, page 146
Linked Mastoid Reference
sensors 26 and 51
Figure H-15, page 147
Right Mastoid Reference
sensor 51
Figure H-18, page 149
Figure D-1. 10-20 (256-channel Net)
140
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D: Montages
Figure D-2. 10-20 (128-channel Net)
Figure D-3. 10-20 (64-channel Net)
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D: Montages
Figure D-4. Double Banana (256-channel Net)
Figure D-5. Double Banana (128-channel Net)
142
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D: Montages
Figure D-6. Double Banana (64-channel Net)
Figure D-7. Eyes (256-channel Net)
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D: Montages
Figure D-8. Eyes (126-channel Net)
Figure D-9. Eyes (64-channel Net)
144
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D: Montages
Figure D-10. Left Mastoid Reference (256-channel Net)
Figure D-11. Left Mastoid Reference (128-channel Net)
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D: Montages
Figure D-12. Left Mastoid Reference (64-channel Net)
Figure D-13. Linked Mastoid Reference (256-channel Net)
146
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D: Montages
Figure D-14. Linked Mastoid Reference (128-channel Net)
Figure D-15. Linked Mastoid Reference (64-channel Net)
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D: Montages
Figure D-16. Right Mastoid Reference (256-channel Net)
Figure D-17. Right Mastoid Reference (128-channel Net)
148
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D: Montages
Figure D-18. Right Mastoid Reference (64-channel Net)
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D: Montages
150
Net Station Acquisition Technical Manual
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GLOSSARY
A
A/D units The digital values reported
by the Net Amps amplifier after
sampling and conversion of analog
signals.
Absolute Time Standard time as
reckoned by the local clock. Also called
Clock Time.
Acquisition Setup file A saved
Workbench configuration that preserves
the control and display settings that
were in effect at the time the file was
saved. A setup can be multipurpose or
specialized for specific acquisition
needs, depending on the devices
included.
aliasing Distortion of the EEG signal,
which occurs when the signal is
digitized at a rate less than half the
highest frequency present. See Nyquist
frequency.
amp/amperage A measure of the
amount of current, or number of
electrons, moving across a point.
antialiasing Filtering a signal prior to
digitization so that high-frequency
Net Station Acquisition Technical Manual
components do not appear as false
lower-frequency components. See
aliasing.
artifact An inaccurate observation,
effect, or result, especially one resulting
from the technology used in scientific
investigation or from experimental
error.
attenuate To reduce the amplitude of
an action or signal. The opposite of
amplification.
autonaming A procedure used by
Net Station to supply a file name
automatically when the user has not
specified one.
autosaving A process by which data
are automatically saved to disk without
requiring any action by the user.
B
bandpass filter A tuned circuit
designed to pass a band of frequencies
between a lower cut-off frequency (f1)
and a higher cut-off frequency (f2).
Frequencies above and below the pass
band are heavily attenuated.
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151
Glossary
bandstop filter A tuned circuit
designed to stop frequencies between a
lower cut-off frequency (f1) and a higher
cut-off frequency (f2) of the amplifier
while passing all other frequencies.
Bessel filter An IIR filter that produces
the most linear phase response of all IIR
filters, with no consideration of the
frequency magnitude response. Bessel
filters tend to have maximally constant
group delay.
C
calibration signal A signal generated
internally in the Net Amps for the
purpose of measuring gains and
impedances. This signal is a 20 Hz,
400 µV peak-to-peak sine wave.
channel Each sensor of the Geodesic
Sensor Net is cabled into the Net Amps
amplifier where its signal is converted
into a stream of digital values. Each of
these streams is the data of a channel.
Net Station handles channel data by
storing them in tracks, which can be
recorded onto a computer disk as a file,
along with event tracks containing
events. In a hardware context, a channel
is one of the instrumentation amplifiers
inside the Net Amps. Channel is also the
name of one of the unique combinations
of bits constituting a digital input (DIN).
See DIN.
channel gains Each amplifier channel
of the Net Amps has a particular gain,
similar to that of the other channels but
not identical. To calibrate the amplifiers
for gain, the output of each channel is
152
electronically measured while an
identical calibration signal is applied to
each. Recorded and stored by
Net Station as A/D units, these
measurements—the channel gains—
provide a means for calculating a
channel-specific scaling factor. The
scaling factor, in turn, enables Net
Station to accurately convert A/D units
to microvolt data. See also channel zeros.
channel zeros Each amplifier channel of
the Net Amps has a particular response
to a potential of zero volts applied to its
inputs. To calibrate the amplifiers for
zeros, the output of each channel is
electronically measured while zero volts
are applied to its inputs. Recorded and
stored by Net Station as A/D units,
these measurements—the channel
zeros—provide a means for calculating
channel-specific offset factors. The offset
factors, in turn, enable Net Station to
acquire microvolt data without
inaccuracies from channel-by-channel
variations in zero response. See also
channel gains.
Clock Time Synonymous with Absolute
Time in the terminology of Net Station.
CMR See common mode rejection.
common An electrical point that
functions in much the same way that an
earth ground does, but is separated from
earth ground by an isolation barrier
(typically thousands of volts of
isolation) in the interest of safety.
common mode rejection A measure of
the attenuation of noise induced in the
signal or reference lines relative to
Net Station Acquisition Technical Manual
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Glossary
common. The ratio is typically
expressed in decibels.
conductivity A measure of the
tendency of a material to transmit
electrons; the reciprocal of impedance.
filtering can be in the form of a software
routine operating on data stored in
computer memory or can be
implemented with dedicated digital
hardware.
digital input See DIN.
cutoff frequency Frequency at which
the power gain of an amplifier falls
below 50% of maximum.
D
DAC data-acquisition computer.
dB See decibel.
decibel A logarithmic measure of the
ratio between two values. For electrical
signals, the measure is –20 log10(A0/A1).
A ratio of 1/1000, for example,
corresponds to –60 dB.
dense (sensor) array Any (sensor)
system that supports sufficient number
of sensors to spatially sample a
phenomenon adequately. For EEG
recording, this generally means 64
channels or more.
deploy A term referring to when an
interface panel that is initially not visible
on the screen is brought into view by
using a button or menu command.
device See Net Station device.
digital filter A computational process,
or algorithm, transforming a discrete
sequence of numbers (the input) into
another discrete sequence of numbers
(the output) having a modified
frequency domain spectrum. Digital
Net Station Acquisition Technical Manual
digitization The process of putting
data into digital form.
DIN A Net Amps digital input, or an
event caused by a state change on one or
more of the eight digital inputs on the
back panel of the Net Amps 200
amplifier.
drift The change in a signal’s offset
over time, or the amount by which a
signal’s offset changes with time.
DWD Dense Waveform Display.
E
ECI See Experimental Control Interface.
EEG electroencephalography. The
science of graphically recording the
electrical activity of the brain as
recorded by an electroencephalograph.
electrostatic discharge The transfer of
an electrostatic charge between bodies at
different electrostatic potentials
(voltages), caused by direct contact or
induced by an electrostatic field.
elliptical filter An IIR filter that
produces the sharpest rolloff for a given
number of filter taps. Elliptical filters
have the poorest phase linearity of the
most common IIR filter design
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153
Glossary
functions. The ripple in the passband
and stopband are equal with elliptic
filters.
epoch When the Net Station
Workbench is turned on and records
EEG data, then is turned off, the EEG
that has been recorded corresponds to a
single epoch. Each time this occurs, a
new epoch is generated. More generally,
an epoch is any stretch of uninterrupted
EEG or time.
Epoch Time One of the four time modes
used by Net Station. Epoch Time is set to
zero at the beginning of every recording
epoch, and epochs are numbered
starting with 1. See Clock Time,
Recording Time, and Relative Time.
ERP See event-related potential.
ESD See electrostatic discharge.
event A marker indicating a point of
interest in an EEG recording.
event-related potential An EEG
waveform elicited by a stimulus such as
an auditory or visual event.
event track In Net Station, an event
track is a container for events.
Net Station displays event tracks and
their constituent events in its waveform
viewer in the form of “flags.”
Experimental Control Interface Built
into Net Station is a protocol for
experimental control technology that
uses the Experimental Control Interface
device along with a messaging system.
154
F
filter length Refers to the number of
impulse response coefficients used to
approximate the corresponding FIR
filter.
filter order Refers to the order of the
highest-order term in the polynomial
used to approximate the corresponding
IIR filter.
Finder On Macintosh computers, the
Finder is the program that keeps track of
files and folders and displays the
desktop (the working area on the screen
with disk icons, a Trash icon, and so on).
FIR filter finite impulse response filter.
An FIR filter calculates current output
solely from the current and previous
input values. defines a class of digital
filters that has only zeros on the z-plane.
The key implications of this are that FIR
filters are always stable and have linear
phase responses (as long as the filter's
coefficients are symmetrical). For a
given filter order, FIR filters have a
much more gradual transition region
rolloff than digital IIR filters.
G
gain The amount by which a signal is
amplified. A gain of 100 increases signal
amplitude by 100 times.
Geodesic Sensor Net Electrical
Geodesics’ dense sensor array.
Net Station Acquisition Technical Manual
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Glossary
H
Hertz Cycles per second. Something
that occurs with a frequency of 10 Hertz
happens 10 times each second.
Abbreviated Hz.
highpass filter A tuned circuit designed
to pass all frequencies above a
designated cut-off frequency.
Frequencies below the cut-off frequency
are rejected or attenuated.
histogram A bar graph of a frequency
distribution in which the widths of the
bars are proportional to the classes into
which the variable has been divided and
the heights of the bars are proportional
to the class frequencies.
I
IMR See isolation mode rejection.
interface cable The cable connecting
the Geodesic Sensor Net to the
Net Amps. The interface cable
connectors are Hypertronics connectors.
This cable is also known as the Geodesic
Sensor Net Interface Cable.
isolated common See common.
isolation mode rejection A measure of
the attenuation of ambient electrical
noise common to all electrodes and
common in relation to mains supply
ground.
J
iconize In graphical user interface
terms, a way to maximize screen space
by reversibly causing a window to
shrink down to a token that is much
smaller than the window.
IIR filter infinite impulse response
filter. A class of digital filters that may
have both zeros and poles on the zplane. As such, IIR filters are not
guaranteed to be stable and almost
always have nonlinear phase responses.
For a given filter order (number of IIR
feedback taps), IIR filters have a much
steeper transition region rolloff than FIR
filters.
impedance The alternating current
equivalent of resistance, impedance is
the measurement of the resistance to the
Net Station Acquisition Technical Manual
flow of electricity for a particular
substance. Electrode/scalp impedances
affect waveform susceptibility to
environmental noise.
jack Socket or connector into which a
plug may be inserted.
L
lowpass filter A tuned circuit designed
to pass all frequencies below a
designated cut-off frequency.
M
magnitude response The amount a filter
attenuates the amplitude of each
frequency component.
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155
Glossary
metadata Data about data. Examples
include the name of the subject of an
EEG data-acquisition session, the date of
the session, the number of epochs. See
metadata field for how Net Station keeps
track of the metadata associated with an
EEG Session file.
metadata field The metadata connected
with a Net Station file, also called the
Session information, are stored in
components called fields. A field has a
label that identifies what kind of data it
holds.
montage One of several methods of
combining, selecting, or arranging data
from multiple sensor locations, or the
result of defining one of such methods.
On a given montage, a combined
waveform is a derivative of the
waveforms at the sensors chosen to be
combined. A selection of sensors results
in the display of a subset of all the
sensors originally used to make a
recording.
MRI Magnetic Resonance Imaging uses
computer imaging of atomic response to
radio waves in a magnetic field to
generate imagery of tissue.
N
Net Amps Electrical Geodesics’ densearray amplifier.
156
file. Each device can perform a task or a
closely related set of tasks. Acquisition
Setups are built from devices assembled
and connected together on the
Workbench.
noise Unwanted electromagnetic
radiation within an electrical or
mechanical system.
notch filter A filter which blocks a
narrow band of frequencies and passes
all frequencies above and below the
band.
Nyquist frequency The maximum
frequency able to be characterized for a
given sampling rate. The Nyquist
frequency is typically taken to be 2/5 of
the sampling rate, for engineering
purposes. See also antialiasing.
O
offset With reference to waveforms,
offset is a DC deviation or the amount of
DC deviation from zero.
P
packetization The process of bundling
information into data structures that can
be sent from one hardware device to
another.
Net Station Electrical Geodesics’ dataacquisition software.
passband For a filter, refers to the range
of frequencies the filter will not
attenuate.
Net Station device A software module
used in a Workbench configuration that
can be saved as an Acquisition Setup
passband gain For a filter, refers to the
amount of a signal that is retained in the
Net Station Acquisition Technical Manual
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Glossary
passband. For example, a passband gain
of 0.1 dB would result in approximately
98.86% of the signal being retained. A
passband gain of 1 dB would result in
approximately 89.13% of the signal
being retained.
pixel A single picture element. A pixel
is a point in 2D with a single color value.
The number of pixels visible on a
monitor is controlled by the monitor’s
resolution setting.
plug Movable connector that is
normally connected into a socket or jack.
port A site for passing data in and out
of a computer.
R
Recording Time One of four time
modes used by Net Station. Time
relative to the beginning of a Net Station
Session. See Clock Time, Epoch Time, and
Relative Time.
reference An electrical point that is
treated as zero for purposes of
amplifying electrical signals. The
Geodesic Sensor Net has a reference
electrode located at the vertex.
refresh rate The frequency, expressed in
Hertz, with which each pixel on a
particular monitor is updated with new
information.
Relative Time One of the four
Net Station time modes. Relative Time is
the amount of time since the Workbench
was turned on. With a session, the time
Net Station Acquisition Technical Manual
since the session began. See Clock Time,
Epoch Time, and Recording Time.
rolloff A term used to describe the
steepness, or slope, of the filter response
in the transition region from the
passband to the stopband.
S
sample When a continuous signal is
measured by examining it at discrete
moments in time, each measurement
corresponds to a sample.
sampling rate The number of times per
second that data are temporally
sampled.
scaling factor To convert an A/D unit
into its corresponding µV value, a
channel-specific scaling factor is applied
in the following manner: sample value
in µV = (A/D Unit – channel zero) x
(cal signal amplitude) / channel gain.
scaling factor In Net Station, a linear
factor used to change the vertical or
horizontal appearance of a waveform to
facilitate its study.
segment A discrete portion of EEG,
especially as a product of segmentation.
sensor A device that picks up a signal
being generated by something in the real
world.
sensor layout Descriptive information
for a particular quantity and
arrangement of sensors. Includes 2D
and/or 3D coordinates specifying the
locations of sensors, labels (names) of
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157
Glossary
sensors, and connectivity. Such
information is stored in a sensor layout
file.
session In Net Station, an EEG
recording requiring the use of a Session
Template.
toggle Each time a button is clicked, it
changes the state of what it is controlling
to one of two possible states and is said
to toggle between the states.
track A container used to hold and
separate data types (for example, EEG
and events).
session information See metadata.
signal A detectable, measurable
quantity that can be expected to display
periodicity or other forms of variation in
time.
transition band Refers to the frequency
range in which a filter is transitioning
from retaining the signal to attenuating
it. Typically measured in Hertz. For
example, we might refer to a transition
band from 10–11 Hz.
spatial sampling The process of
sampling a 3D space at regular locations
in a given instant of time. Compare with
temporal sampling.
U
stopband Refers to the frequency range
in which a signal is to be attenuated.
stopband gain For a filter, refers to the
amount of the signal that is attenuated
in the stopband. For example, a
stopband gain of 40 dB would result in
99% of the signal being attenuated. A
stopband gain of 20 dB would result in
90% of the signal being attenuated.
T
temporal sampling The process of
sampling a given location at regular
intervals in time. Compare with spatial
sampling.
time base The fundamental unit of
Net Station time; everything occurs in
multiples of this unit. Net Station uses a
millisecond time base.
158
USB Universal Serial Bus.
V
vertex The point on an EEG subject’s
scalp that is closest to the top of the
head. In the International 10-20 system,
Cz is the vertex electrode. In the Adult
128 GSN, electrode #129 is the vertex.
The point on the scalp or skull located
midway between the nasion and inion
and centered between the periauricular
points. Also the name of the Geodesic
Sensor Net sensor that corresponds to
this location and that contains the
reference electrode.
volt/voltage A measure of electrical
force, or the tendency for electrons to
move from one location to another.
Voltages are measured with respect to a
reference.
Net Station Acquisition Technical Manual
S-MAN-200-ACQR-001 • September 30, 2003
Glossary
W
waveform Any graphical
representation of a signal.
WFR Waveform Recorder device.
Workbench The Net Station equivalent
of an electronics laboratory. On the
Workbench, modular device are
connected by data cables into
Workbench configurations of differing
functionality. See Acquisition Setup file.
Workbench Time Synonym for Relative
Time when using the Workbench.
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Glossary
160
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INDEX
A
amplifier, role in data collection
Absolute Time
Acq menu
Amplitude menu
57
acquiring data with
embedded
Auto Set to Nyquist checkbox
38
average referencing
100
22
60
53
117
Acquisition Setups folder
B
33
Acquisition Setups, defaults
94
Experimental Control Setup
(configuration)
98
(panel deployment)
95
Advanced Event Setup panel
Calibration track
amplifier calibration
72
47, 60
Amplifier History files
60
60
110
Channel Key Code
67
60, 62
113
channel spacing, changing of
channel tiles
60
69
Channel Resize buttons
112, 114
113
resizing of
126
43, 137
channel gain, in-bounds values
66
Advanced Net Amps Controls panel
Amp Diagnostics panel
125
Calibrate Amplifier button
97
39
Advanced Event Setup button
51
C
96
Typical (panel deployment)
Acquisition status panel
bandstop filters
94
Primitive (panel deployment)
Typical (configuration)
51
Bipolar Montage Editor panel
99
Primitive (configuration)
bandpass filters
Begin Session button
Experimental Control Setup
automatic
48
Appletalk, turn on for Net Station
Acquisition Setups
creating new
92
analog signal filtering
87
22
114
Channel Visibility label
112, 113
channel zero, in-bounds values
Control panel button
control panels
core components
50
21
Create New Field window
Net Station Acquisition Technical Manual
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61
43
121
161
Index
Disk full message
D
Disk Monitor subpanel
data packets
26
Display menu
data protection
26
DB-9 connector
22
Documents folder
channel tiles
105
E
107
113
Events control strip
Edge button, registering changes in
110
occurrence
105
mark events
111
107
Reset button
107
EEG jack
108
Epoch Time
109
111
Visibility button
event keys
113
114
Dense Waveform Display device
112
48
Dense Waveform Display menu bar
Dense Waveform Display panel
digital event channel
67
Digital Filter controls
50
72
69
66
110
93
66
62, 64
Extras folder
66
44, 138
83
32
70
F
Field Type pop-up menu
121
File Exporter application
32
diagnostic and calibration information
how to launch
62
attaching devices
64
DIN tracks, naming of
66
DIN/ECI track
Events menu
64
DIN events, eight tracks
DIN port
107
Events control strip
Experimental Control Status
43, 137
assigning to event tracks
DIN event structure
Events button
70
set up DIN channels
digital inputs
using
42
event tracks, defaults
Experimental Control Interface panel
Digital Input Controls panel
turn Workbench off
68
69
Event marking jack
Events tabpanel
44
Digital Filter panel
84
43, 72, 137
49
Devices palette
69
69
Event Label
Waveform Options control strip
device panels
69
Event Identifiers subpanel
107
123, 124
57
event counters
Event Identifier Code
upper control strip
134
68
Enter Session Information window
110
waveform area
42
Enabled box
113
Time control strip
24
EGI licenses, questions regarding
Scale control strip
Tracks area
86
EEG, display and recording of
Pause button
sweep line
70
Edit menu
107
time ruler
74
33
62
Acquisition Status panel
menus
43
display panels, organization and function of
22
Dense Waveform Display
invoking
25
Display panel button
role in data collection
with Net Station
56
91
display of EEG
data-acquisition computer
162
24
File menu
32
32
85
110
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Index
Channel Key Code
G
event counters
Gains display panel
75
event keys
generating epochs of same duration
Global Key Code
58
Grid toggle button
69
69
Global Key Code
69
Key Code
113
69
69
Keyboard button
H
69
65
L
hard drive, turn sleep off
Highpass button
22
Lowpass button
51
highpass filters
lowpass filters
51
highpass hardware filtering
51
lowpass hardware filter settings
60
automatic cut-off frequency
77
62
I
51
M
iconize, of a display panel
74, 88
Mac desktop items
Identify Subject subpanel
124
mapping pin numbers to DIN
IIR filtering
52
mark events
111
110
Impedance Display panel
79
Marks track
impedance measurement
127
Measure button
impedance measurement method
82
60
61, 81, 127
Measuring Zeros progress bar
60
81
81
81
Over button
82
Threshold box
82
82
Under button
montage
10-20 (128 channels)
141
Double Banana (128 channels)
142
Double Banana (256 channels)
142
effect on data
43
52
49
Eyes (128 channels)
144
144
Eyes with 256 channels
70
Insert Comment command
121
143
53
Eyes (64 channels)
Input Matching controls
Insert Fields window
140
141
Double Banana (64 channels)
82
infinite impulse response filtering
info panels
115, 118
10-20 (64 channels)
82
Show Labels checkbox
Info panel button
metadata
10-20 (256 channels)
orientation buttons
61
Measuring Gains progress bar
Impedance Measurement window controls
All button
61, 79
61
green sensors (within Threshold)
red sensors (exceed Threshold)
63
Measure Net Impedance button
Impedance Measurement progress bar
Impedance Measurement window
30
143
Left Mastoid Reference (128 channels)
112
Left Mastoid Reference (256 channels)
Left Mastoid Reference (64 channels)
145
145
146
Linked Mastoid Reference
(128 channels)
K
Key Code
key list
147
Linked Mastoid Reference
69
(256 channels)
146
69
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Index
Montage controls
Linked Mastoid Reference
(64 channels)
53
how to deploy
147
Right Mastoid Reference (128 channels)
Right Mastoid Reference (256 channels)
Right Mastoid Reference (64 channels)
53
148
montage, brief definition of
148
montages
defaults
149
53
139
referencing schemes
139
N
Net Amps Controls
58
Net Amps USB display panels
Net Amps USB panel
Net Amps USB panels
Net noise test
73
44
138
77
Net Station
Disk Monitor
56
EEG data file types
folder files
55
31
Recording files
55
root directory
Session file
30
56
Time Indicator
56
Workbench and devices, introduction to
35
Net Station Acquisition
basic operation
23
functional diagram
intended use
overview
23
21
21
Net Station Application Program Package
files
Net Station Distribution
files
32
32
28
30
Net Station File Exporter
32
diagnostic and calibration information
how to launch
Net Station folder
32
32
31
Net Station recording
elapsed time counter
new
55
55
starting
stopping
55
55
Net Station Recording maximum file size
164
Net Station Acquisition Technical Manual
55
S-MAN-200-ACQR-001 • September 30, 2003
Index
Net Station session
starting
Reset button
115
Resource Database
56
stopping
Net Station User Data folder
33
121
Sampling Rate button
47
Scale button
Noise display panel
76
Select Session Template window
78
sensor array, role in data collection
how to bypass
appearance in low noise
Noise vs. Time inset plot
Notch button
77
77
Session file
P
Session menu bar
84
Session Template
115
119
automatic amplifier calibration
126
Close Session button
88
components
42
123
128
117
embedded Acquisition Setup
pause
entering mark events
Pause button
how to create
108
pause line, discontinuity of data
25
Presents subpanel
108
123
Identify Subject subpanel
124
impedance measurement
127
Insert Fields window
71
Pulse button, registering changes in
occurrence and duration
70
117
119
how to use
107
56
124
amplifier calibration (optional)
choosing existing one
137
pattern recognition jack
pixels
56
Session Information subpanel
60
22
47
Session files, with multiple epochs
51
Panels menu
123
sensor impedance
51
Nyquist frequency
Panel icons
108
77
Noise panel
appearance in high noise
59
107
Scale control strip
Noise Distribution histogram
notch filters
65
55
S
33
New Field button
noise
34
Response Pad button
56
Net Station Session maximum file size
files
107
metadata fields
121
118
output name and destination
recording EEG
118, 125
128
sensor impedance measurement
R
(optional)
Record menu
session information
89
defaults
38
recording EEG
26
Recording files
55
Recording Time
Sessions folder
55
57
71
114
Source tabpanel
Rename Session window
Net Station Acquisition Technical Manual
103
33
Setup Inputs panel
size box
57
Reset All command
34
relationship with Acquisition Setups
with multiple epochs
Relative Time
124
Session Templates
Recording
on and off
119
125
108
capturing external events
stimuli jack
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65
42
165
Index
Support folder
Waveform Recorder panel
34
Resource Database
sweep line
Workbench
34
Acquisition Setup connections
107, 113
interruption of
44, 138
113
Templates
103
Acquisition status panel
T
39
Advanced Event Setup panel
Templates folder
files
34
Amp Diagnostics panel
amplifier calibration
107
Time control strip
109
Time Indicator subpanel
time ruler
cells
56
core devices
58
58
timed recording
starting
time-mode buttons
57
TTL button
default Experimental Control Setup
98
default Primitive Acquisition Setup
94
Dense Waveform Display device
71
Dense Waveform Display panel
70
111
Tracks tabpanel
100
96
Dense Waveform Display core device
Track assignment pop-up menu
Tracks area
46
default Typical Acquisition Setup
58
Track controls
63
50
creating Acquisition Setups
Timed Record field
editing
35
control panels
110
43
60
configuration for DINs
91
Timed Record button
60
calibration progress bars
109
62
72
Bipolar Montage Editor device
Time Display Options panel
Time menu
67
Advanced Net Amps Controls panel
34
Time button
66
device buttons
43
device panels
43, 49
devices
65
U
110
46
45
Digital Filter controls
Digital Filter device
50
43
Digital Input Controls panel
digital inputs display
V
43, 48
72
44
devices, placing
user mark events, adding to recording
46
35
Devices palette
devices, connecting
62
72
digital inputs, assigning to event tracks
Visibility button
113
DIN event structure
DIN port
70
69
47
display panels, organization and
W
function of
waveform area
Edge button
114
waveform area grid, toggling on and off
Waveform Options control strip
112
Waveform Recorder Controls panel
small and large versions
Waveform Recorder device
166
63
Acquisition Setups, used by Session
54
49
112
74
70
Event Identifiers subpanel
Events tabpanel
68
66
Experimental Control Interface
Experimental Control Status panel
fundamentals
Net Station Acquisition Technical Manual
44
83
35
S-MAN-200-ACQR-001 • September 30, 2003
Index
Gains display panel
Workbench devices
75
highpass hardware filtering
how to open
connecting
62
Impedance Display panel
41
EEG jack
79
impedance measurement method
Filter
82
Impedance Measurement window
42
41
MARK jack
81
inadvisable configuration (filtering before
Mixer
recording)
52
overview
49
PAT jack
info panels
Input Matching and Track controls
Keyboard button
45
41
41
42
Stimulus/Response
Workbench menu bar
Net Amps USB device
47
Noise display panel
41
83
46
Net Amps USB display panels
Z
73
76
Zeros display panel
Noise Distribution histogram
75
77
59
38, 40
pin numbers, mapping to DIN events
Presets subpanel
Pulse button
63
71
70
Response Pad button
65
Sampling Rate button
59
sensor impedance measurements
Source tabpanel
58
time-mode buttons
57
Track assignment pop-up menu
Tracks tabpanel
61
65
Timed Record button
TTL button
STIM jack
61
53
Net Amps USB core device
on and off
Source
60
44
notification area
41
42
Recorder
Measure Net Impedance button
Montage controls
42
41
placing
70
65
lowpass hardware filtering settings
Net Amps USB
45
Display
39
71
66
65
Waveform Recorder controls
54
Waveform Recorder core device
Waveform Recorder device
Zeros display panel
Net Station Acquisition Technical Manual
44, 49
75
Workbench cables and jacks
Workbench configuration
46
42
45
S-MAN-200-ACQR-001 • September 30, 2003
167
Index
168
Net Station Acquisition Technical Manual
S-MAN-200-ACQR-001 • September 30, 2003
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