Biomedical Engineering Reference
In-Depth Information
Enclosure
for bR array
and circuitry
Function generator
4 channel oscilloscope
Tunable laser
Beam
expander
Acousto-
optic deflector
FIGURE 17.23
Experimental setup for motion detection measurement. An acousto-optic deflector is used to sweep the laser
beam across the bR array so that the light spot velocity can be estimated by the motion detection circuitry.
0.5 V threshold
(a)
0.5 V threshold
(b)
(c)
(d)
200 ms delay
(e)
200 ms delay
(f)
(g)
Time
FIGURE 17.24
Waveforms corresponding to the different motion detection stages for two neighboring pixels as a light spot
moves from left to right: (a, b) are the measured amplifier outputs for each pixel; (c, d) are the 5-V output signals
generated by the voltage comparators, which are triggered at a 0.5-V threshold. (e, f) Represent the sample delay
that is applied to the input signals. The delay overlap between the two channels is integrated to produce the out-
put (g).
