Service manual

Revision 2/18/05 3 - 45
Hardware Description
Stimulus Pulse Generators
Neurodiagnostic systems require a Stimulus Pulse
Generator block to trigger the auditory, visual and
electrical stimulators, and to coordinate stimulus
delivery with data collection and processing.
In VIASYS systems, the stimulus generator block
generally shares space on a circuit board with other
VIASYS-unique circuits. These are most often
input/output related circuits that include trigger in/out,
the control panel interface, foot switch interface, LED
goggles interface, ganzfeld interface and reflex hammer
interface.
Endeavor CR and VikingQuest Base
Units
The stimulus pulse generator block and I/O interface for
the Endeavor CR and the Viking Quest are integrated
into the base unit’s main circuit board.
Viking Select SC-1 Stimulus Controller
The stimulus generator block and I/O interface circuits
for the VikingSelect reside in the SC-1 Stimulus
Controller module. The SC-1 receives instructions from
the host computer via a FireWire interface and
communicates with the AS-1, IES-2 and IES-16
stimulator modules via AES serial (Audio Engineering
Society standard serial transmission format).
The SC-1 performs the same functions that were
performed by the D-Stim I/O board in the original
VikingSelect and Endeavor.
The input/output connections on the SC-1 are:
• EMG speaker
• Trigger 1 out
• Trigger 2 out
• Ganzfeld
• Reflex Hammer
• Trigger in
• LED Goggles
• Power
• AES communication
• FireWire
• Footswitch
• Control Panel
Electrical
Stimulator
Auditory
Stimulator
Stimulus
Pulse
Generator
Analog to Digital
Converter
(Digitizer)
Signal
Conditioning
LFF, HFF,
NCH, SNS
Signal
Conditioning
LFF, HFF,
NCH, SNS
MARK
CAL
STIM
Pattern Reversal
Visual Stimulator
Amp
Amp
Electrodes
to Patient
Printer
Input Select Switches
SIGNAL A/B SELECT ADJUST
Generic Evoked Potential Instrument