摘要 |
A method and apparatus for monitoring and obtaining actual bio-electrical characteristics of a subject, such as EEG, or determinants of the psycho-electro-physiological state of the subject, under predetermined conditions of evoked response stimuli, and by interaction with a computer, apply cutaneous electrical stimulation to the subject, using a signal generator to modify current amplitude and frequency in a direction to achieve bio-electrical characteristics in the subject related to the actual bio-electrical characteristics monitored. The signal generator may have an output of several frequencies simultaneously, and uses a sinusoidal waveform output, with battery power passed through a transformer to power a transconductance amplifier to obtain constant current output despite resistance changes in the line with the subject, and with the transformer not placed in the signal path of the sinusoidal waveform. |