Bio-feedback appts. showing mental state - has skin electrodes changing frequency of multivibrator as skin resistance varies

摘要

Changes in skin resistance are indicated optically or acoustically in biofeedback appts. for showing the state of mind of the user. Skin electrodes are connected via a high-resistance potential divider to a d.c. amplifier containing a Darlington pair. The amplifier output is coupled via an opto-coupler to a multi-vibrator which is the signal source for a loud-speaker. Changes in resistance of the photoresistor produce a change in oscillation frequency of the multi-vibrator. The display may alternatively be a line of photodiodes.