In this paper the literature on the myoelectric signal is collected and reviewed for purposes of determining the electronic characteristics from which the optimum specifications for an amplifier used in a myoelectric control system are determined.
An average figure of 5,000 ohms at 10 cycles per second is given as the output impedance of tissue. Accepting a 1 per cent signal loss, the input impedance of the amplifier should be at least 500,000 ohms.
By integrating curves from the literature, it is fourid that the signal energy band is from 25 to 300 cycles per second as determined by the maximum signal/noise ratio in conjuction with a 1 per cent signal loss. The pass band of the amplifier should then be 25 to 300 cycles per second.
Various other electronic problems of myoelectric control are discussed such as type of amplifier, electrodes, alternating current noise pickup, signal variation, and tissue noise.