RETeval Complete Option
RET
eval
Device User Manual 50
On-off long: w/w 250/40 cd
Stimulus luminance
(0.33, 0.33 white)
Background luminance
(0.33, 0.33 white)
White extended stimulus,
white background
250 cd/m²,
144.9 ms on time @ 3.5 Hz
White extended stimulus,
white background
250 cd/m²,
144.9 ms on time @ 3.5 Hz
On-off short: w/w 250/40 cd
Stimulus luminance
(0.33, 0.33 white)
Background luminance
(0.33, 0.33 white)
White extended stimulus,
white background
250 cd/m²,
144.9 ms on time @ 3.5 Hz
White extended stimulus,
white background
250 cd/m²,
144.9 ms on time @ 3.5 Hz
Two additional protocols (a short and long test duration) are provided that use a colored
stimulus. The stimulus is a 560 cd/m
2
red light with a 160 cd/m
2
green background. The on and
off times are both about 209.4 ms. This protocol matches closely to Audo et al. (2008), with the
green background suppressing the rod response. The short protocol uses 100 averages (taking
42 seconds) and the long protocol uses 200 averages (taking 84 seconds).
On-off long: r/g 560/160 cd
Stimulus luminance
(red LED, 621 nm)
Background luminance
(green LED, 530 nm)
Red extended stimulus,
green background
560 cd/m²,
209.4 ms on time @ 2.4 Hz
Red extended stimulus,
green background
560 cd/m²,
209.4 ms on time @ 2.4 Hz
On-off short: r/g 560/160 cd
Stimulus luminance
(red LED, 621 nm)
Background luminance
(green LED, 530 nm)
Red extended stimulus,
green background
560 cd/m²,
209.4 ms on time @ 2.4 Hz
Red extended stimulus,
green background
560 cd/m²,
209.4 ms on time @ 2.4 Hz
To generate the stimuli, the RET
eval
device uses a PWM stimulus near 1 kHz.
The analysis uses the same processing as the ISCEV protocols, with the following exceptions: The
0-phase high pass filter is set to 4 Hz to reduce electrode drift over the extended response
duration. A 0–phase 300 Hz low pass filter is used instead of the wavelet denoising. The 0 time
point in the response is when the stimulus is turned on.
To Next Page
Loading...
