A method for the generation of complex vibrotactile stimuli.
A method is described utilizing computer-generated sine wave data and purpose-built hardware to generate a complex vibrotactile stimulus. Two sine waves of different frequency were summed to produce a complex waveform with two temporal components, a high frequency component and a low frequency beat component. The computer-generated data points for each of the two component sine waves were downloaded to two banks of static memory in a dual synchronous arbitrary function generator. The data points in memory were fed to two 12-bit digital-to-analogue converters which sent the two analogue sine wave signals to a summing amplifier where the two sine waves were added. This method provides a complex waveform that can be gated on and off, has a fixed frequency ratio of the component sine waves and no phase drift between the component waves. Addition of the separate sine waves in a summing amplifier allows for easy alteration of the amplitude ratio of the sine waves. The output of the summing amplifier is sent to a feedback controlled mechanical stimulator, thereby allowing the stimulus to be presented to the skin of human subjects and experimental animals.
School of Physiology and Pharmacology, University of New South Wales, Sydney, Australia.
J W
JW
Morley
E N
EN
Crawford
D G
DG
Ferrington
J S
JS
Archer
A B
AB
Turman
M J
MJ
Rowe
D003201:Computers; D006801:Humans; D010812:Physical Stimulation / Q000295:instrumentation / Q000379:methods*; D014110:Touch / Q000502:physiology*; D014732:Vibration