Project: Anschutz (112 OPM sensors)
Subject: AG
Subject ID: AS24
Date: December 14, 2021
Paradigm: Visual Evoked

Visual Paradigm
Template: VisFIdEF
Quadrant checkerboards one quadrant at a time
Focus on little red dot in the center
Trigger signal comes from Photodiode attached to the back of the screen
ISI: 0.5 sec
5 minutes per quadrant

Triggers
Channel 00:00        HPI tigger
Channel 01:00        Photodiode
Channel 05:00        Sensor localization trigger

Sensor positions
If a location is 00 for x, y, and z, it is a bad channel

Coregistration
Before and after measurement day
HPI coils 1-5, one measurement per file 
43 Hz sine wave
100  Ohm resistor
10 sec measured at two amplitudes: 0.05 V and 0.5V

Two Polhemus files:
Polhemus head shape measurement outside the helmet and inside the helmet
Five point Polhemus file has fiducially, HPI coils, and 5 points on the OPM helmet
	LPA, RPA, Nasion are the fiducials
	Cz, Inion are the coil positions taped to the eyebrow/temple region
	Coil1=LPA coil
	Coil2=RPA coil
	Coil3=Nasion coil
	Coil4=Cz coil around left eyebrow
	Coil5=Inion around right eyebrow
	OPM1-5 are the following reference points on the helmet
	OPM1=Point 1
	OPM2=Point 4
	OPM3=Point 2
	OPM4=Point 3
	OPM5=Point 5
The coordinates in the sensor frame are:

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