ARGUS SCIENCE ETVision Wearable 180 Hz binocular Eye Tracking System Instruction Manual
- June 10, 2024
- ARGUS SCIENCE
Table of Contents
ARGUS SCIENCE ETVision Wearable 180 Hz binocular Eye Tracking System
Eye Tracker Systems Manual ETPhone for use with ETVision
MANUAL VERSION 1.1 November 2022
techsupport@argusscience.com Web site: www.argusscience.com
ETPhone with ETVision Manual
Table of Contents
- GENERAL DESCRIPTIONINSTALLATION
- ETPHONE OPERATION
Product General Description
ETPhone is an iPhone app that can assist in the use of the Argus Science ETVision eyetracker. It can be used simply to display the AutoCalibration target used by ETVision, but can also be used to substitute for functions normally performed by the ETVision PC when it is not convenient for the PC to be in WiFi range. In addition to simply displaying the ETVision AutoCalibration target, the ETPhone app can:
- Establish WiFi communication between ETPhone and the ETVision Controller
- Monitor ETVision cameras and performance
Product Installation
- Search for ETPhone on the iPhone App Store.
- Touch the download icon to download and install the app.
ETPhone Operation
Display Auto Calibration Target
Open the ETPhone App and touch the calibration target icon. A full size calibration target image will fill the iPhone screen as shown on the right image below. Touch the center of large target to return to the home screen.
ETPhone home screen (no Wi-Fi connection)
Full screen Auto Calibration target
Establish WiFi communication between ETPhone and the ETVision Controller
To establish WiFi communication between ETPhone and the ETVision Controller, follow these steps:
- Ensure that your iPhone and the ETVision Controller are connected to the same WiFi network.
- Open the ETPhone app.
- Tap the WiFi connection button.
- Follow the on-screen instructions to establish a connection.
Monitor ETVision cameras and performance
To monitor ETVision cameras and performance, follow these steps:
- Open the ETPhone app.
- Hold the phone horizontally to display the features.
- The Eye image displays show the same feature recognition overlays for the pupil, corneal reflections, and eyelid positions as the standard ETVision PC display.
- The slider under the left eye image controls eye camera gain for both eyes (default = 10), and the slider under the right eye image controls the quality ratio for both eye cameras (default = 70).
- The slider under the scene camera image controls image quality (default = 70).
- If the eye features are being successfully recognized, the scene image will show a superimposed point-of-gaze cursor.
- The Microphone Gain slider can be used to adjust the volume of audio that will be picked up by the head gear microphone and recorded on either SD card recordings or phone recordings.
General Description
ETPhone is an iPhone app that can assist in the use of the Argus Science
ETVision eyetracker. It can be used simply to display the AutoCalibration
target used by ETVision, but can also be used to substitute for functions
normally performed by the ETVision PC when it is not convenient for the PC to
be in WiFi range.
In addition to simply displaying the ETVision AutoCalibration target, the
ETPhone app can:
- Establish a WiFi connection to the ETVision Controller.
- Display eye and scene camera images with superimposed eye feature recognition overlays and a superimposed point-of-gaze cursor.
- Start and stop SD card recording by the ETVision Controller.
- Perform Auto Calibration and record 30 Hz digital data, as well as scene camera video files to iPhone memory.
If using ETVision in an environment where it is not convenient to bring the
ETVision PC, ETPhone can be used to verify that head mounted cameras are
properly aimed, that eye features will be properly recognized, and that a
subject auto calibration will be successful before starting SD card recording
on the Controller. It can also be used to adjust the camera gain and
compression ratio, and subject head phone and microphone volumes, if
necessary. The video data recorded on the SD card can later be played back
through the ETVision PC to produce 180 Hz eye tracking data (see ETVision
manual, section 7.8.3).
Alternately, if only 30 Hz data is required (rather than 180 Hz data) and
recording period will be reasonably short, data can be recorded directly on
the iPhone by the ETPhone app.
The ETPhone app will run on iPhone 8 or above with IOS 16.0 or above.
Installation
Search for “ETPhone” on the iPhone App Store.
Touch the download icon to download and install the app.
ETPhone Operation
Display Auto Calibration Target
Open the ETPhone App and touch the calibration target icon. A full size
calibration target image will fill the iPhone screen as shown on the right
image below. Touch the center of large target to return to the home screen.
ETPhone home screen (no Wi-Fi connection) 
Full screen Auto Calibration target 
Establish WiFi communication between ETPhone and the ETVision Controller
- Close the ETPhone app if already opened.
- Be sure that the ETVision controller is connected to the head mounted optics, and that it is powered on (green power light if controller is connected to a power outlet; blue power light if running on battery power).
- Be sure no other device is connected to ETVision controller (the controller will only connect to one device at a time).
- Go to iPhone “Settings > Wi-Fi”. If the phone is within Wi-Fi range of the ETVision Controller, the Networks list should include the ETVision serial number listed on the Controller back panel label. Touch this item to connect. If asked for a password, use the password listed on the Controller back panel label. A check mark will appear next to the network name to indicate a successful connection.
- Close “Settings” and open the ETPhone app. An ETVision interface screen should appear showing the eye and scene images from the head mounted cameras.
Holding the Phone horizontally produces the display shown below. This display
can be scrolled to expose the additional items shown at the bottom of the
vertical display. 
Monitor ETVision cameras and performance
The Eye image displays show the same feature recognition overlays for the
pupil, corneal reflections, and eyelid positions as the standard ETVision PC
display. These are explained in section 7.8 of the ETVision manual. The slider
under the left eye image controls eye camera gain for both eyes (default =
10), and the slider under the right eye image controls the quality ratio for
both eye cameras (default = 70).
The slider under the scene camera image controls image quality (default = 70).
If the eye features are being successfully recognized, the scene image will
show a superimposed point-of-gaze cursor. On ETPhone, the point of gaze cursor
is always a green circle as shown on the sample images. Unlike the cursor on
the ETVision PC application, it is not configurable.
The Microphone Gain slider can be used to adjust the volume of audio that will
be picked up by the head gear microphone and recorded on either SD card
recordings or phone recordings.
Auto Calibrate
To perform a subject Auto Calibration, touch the target icon at the top of the
ETPhone screen to produce the full screen target display. Hold the target
still at about an arms length in front of the subject (or have the subject
hold it themselves), and ask the subject to fixate the center of the target.
When ETPhone detects that calibration has been successful (target recognized
in scene camera image, and eye position stable for about a second) the full
screen target will disappear and the standard display will reappear. Touching
the center of the full screen target will cause the standard screen to return
even if the calibration criteria have not been met.
Calibration results will be reflected in 30 Hz recordings saved on the iPhone,
but will not be saved by SD card recordings.
In the case of SD card recordings, only the raw video information is saved.
The calibration must be done during the off-line process when the SD
recordings are played back through the ETVision PC application. Nevertheless,
if recording to an SD card, it is recommended that an ETPhone Auto Calibration
be done after SD card recording begins. This section of video data can then be
used to do an Auto Calibration (or manual single point calibration) during
off- line SD card file playback.
Auto Calibration is the only subject calibration procedure available on
ETPhone. Manual and multi point calibration procedures available on the
ETVision PC application are not supported by ETPhone. Assuming appropriate
video data was collected (periods where the subject was know to be fixating
target points) these options will still be available during SD card file
playback using the ETVision PC application.
Set “Profile” name
Files recorded either by the controller on an SD card or directly on the
iPhone will have a file name consisting of the “Profile” name followed by a
date and time code corresponding to the controller clock value when recording
begins. To set the “Profile” name type the desired file name in the “Profile”
name field on the ETPhone app, and touch the profile symbol to the right of
the name field to set the profile name.
Control SD card recording
To control SD card recording with ETPhone, first establish a Wi-Fi connection
as previously described. If an SD card is detected by the ETVision Controller
the SD card record button on ETPhone will be active. If this button is “grayed
out” ensure that an SD card is correctly inserted in the ETVision Controller.
The SD card record button should then appear active.
Start recording by touching the SD card record button. An SD card file, with a
name consisting of the profile name followed by a date and time code, will
start recording, and the SD card record button will change to a pause symbol.
The iPhone record button will be disabled, and turn gray. It is not possible
to simultaneously record both to an SD card and directly to the phone.
As mentioned in the previous section, it is recommended that an ETPhone Auto
Calibration be done after SD card recording begins. This section of video data
can then be used to do an Auto Calibration (or manual single point
calibration) during off- line SD card file playback.
To stop recording to the SD, touch the pause symbol. The button will revert to
showing the record symbol (and the phone record symbol will once again become
active). To record another file to the SD card, touch the SD card record
button again. A new file will begin recording. Each file recorded will be
named with the current profile name and a time code corresponding to the
Controller clock value when recording started. After each recording starts, it
is recommended that the subject fixate the Auto Calibration target, as
previously described, to provide a period of video data that can be used for
Calibration during SD card file playback.
To process recorded SD card files and create eye-tracking data, follow
instruction in section 7.8.3 of the ETVision manual.
Record eyetracking data files on the iPhone
A fixed digital data set along with the scene camera video can be recorded 30
times per second directly on an iPhone running ETPhone. Note: Rather than
recording directly to the iPhone, we normally recommend recording to the SD
card for subsequent processing or directly to a PC since these options produce
data with the most robust feature recognition and highest update rate (180
Hz).
If the subject is not already calibrated, perform a subject Auto Calibration
as previously described in section 3.4.
To start recording 30 Hz data to the iPhone, touch the phone record button.
The record symbol will change to a pause symbol. Even if there is an SD card
in the controller, the SD card record button will become inactive and will
turn gray when recording to the phone begins (it is not possible to
simultaneously record both to an SD card and directly to the phone). Stop
recording by touching the pause button on ETPhone.
A digital data file and a scene camera video file will be recorded, both at
30Hz. Both files will have a file name consisting of the Profile name followed
by a date and time code. The data file will have a “csv” extension, and the
video file will have a “mov” extension. The data file format will be the csv
file format described in the ETVision manual, but with 30 samples per second
rather than 180 samples per second.
The size of the digital data file will usually be just over 8 KB/sec. The size
of the video file will depend on scene camera “quality” value and video
content, but will usually be about 0.8 MB/sec.
The data items recorded on the digital data file are listed below.
Time
Status
overtime_count
mark_value
CU_video_field_num
left_pupil_pos
right_pupil_pos
left_pupil_diam
right_pupil_diam
left_pupil_height
right_pupil_height
left_ellipse_angle
right_ellipse_angle
left_eyelid_upper_vert
right_eyelid_upper_vert
left_eyelid_lower_vert
right_eyelid_lower_vert
left_cr_pos
right_cr_pos
left_cr_diam
right_cr_diam
left_cr2_pos
right_cr2_pos
left_cr2_diam
right_cr2_diam
horz_gaze_coord
vert_gaze_coord
vergence_angle
verg_gaze_coord
left_eye_location
right_eye_location
left_gaze_dir
right_gaze_dir
An explanation of each data item can be found in Appendix C of the ETVision
manual.
To view files recorded by ETPhone, open the “Files” app on the iPhone. Under
“Browse”, select “On my iPhone”, then select the “ETPhone” folder to see the
list of recorded ETVision files. Swipe a file name to the left and touch the
“trash” icon to delete the file. Touch the file name to view the file; and
then touch the “send” icon to send files to other devices via email, air drop,
etc. (Note that some files might be too large to send via email). Alternately,
connect the iPhone to a PC and use the PC iTunes app to transfer files.
Files recorded by ETPhone can be processed by ETAnalysis in the usual fashion,
but of course need to be first transferred to a PC running ETAnalysis. Because
of the low temporal resolution (30 Hz update rate), data recorded on ETPhone
is usually not appropriate for the saccade analysis available on ETAnalysis.