Model DDIS- 1
Description:
The Model DDIS- 1 is an instrument for the separation of either a single
neural spike trains from a multiunit recording containing more than one
neural element utilizing two point discrimination or two different class
spike trains from a single multiunit recording. The Model DDIS-l produces
two windows in time as well as amplitude. The windows can be adjusted in
height, above or below baseline and anywhere in time up to 5 msec after
a trigger point for window A and up to 5 msec from window A for window
B. The trigger point is set by a continuously adjustable level control
for either positive or negative slope detection. The signal and all window
levels are multiplexed so that only one channel of the oscilloscope is
necessary. Multiplexing eliminates adjusting the oscilloscope levels for
drift; also, no z axis intensification is required. The DDIS-1 has an analog
delay circuit with Xl and X2 delay capability built into it making this
unit the complete spike recognition system. The initial trigger threshold
may be set while viewing the raw data inputted to the unit. The signal
is then passed through the Xl analog delay before going to the multiplexed
output circuitry so that one can view the entire waveform when setting
up the discrimination parameters. An additional X2 delay is provided at
the "DELAY OUT" output so that an acceptance pulse can trigger an additional
oscilloscope which will still view the entire waveform giving visual confirmation
of the discriminated spike. A" SELECT AC" switch is provided to multiplex
any of the acceptance pulse outputs as a low amplitude negative spike on
the trigger output line with the positive TTL trigger pulse for quickly
triggering the CRT from either the trigger pulse or acceptance pulse by
adjusting the scope trigger level. Acceptance pulse is not changed. The
Model DDIS-l is of modular construction and slides easily into the Model
RP-l rack mount power supply module cage system.
| Input Resistance | 10 kilohms |
| Input Coupling | AC |
| Input Dynamic Range | 6 Volts peak to peak |
| Delay and Multiplexed Output Resistance | 100 ohms |
| All Other Outputs | TTL compatible |
| Signal Polarity | Same as input |
| Gain | Unity |
| Bandwidth | 20 Hz to 20 kHz (3 db down) |
| Window Widths | Short 20 microseconds, Long 70 microseconds |
| Window Delay | 0.05 msec to 5 msec for window A, O~5 msec from window A for window B (continuously adjustable) |
| Window Height | Continuously adjustable |
| Trigger Threshold Level | Internal plus or minus along signal waveform or an external TTL pulse |
| Output Trigger Pulse | TTL UL - 10 microsecond width with low level negative spike at selectable acceptance time |
| Output Acceptance Pulses | TTL comparable .2 millisecond width (internally adjustable) |
| Power Requirements | 15 volt + 15 volt supplied by Model RP-1 Power Supply |
| Size | 5.6"Wx5.25"H x 7.25"D |
| Weight | 11/2 lbs. |
