Versatile three-channel stimulation controller for restoration of bladder function in paraplegia.

This compact Ni-Cd powered stimulation controller has been designed to operate, by means of appropriate transmitters, a three-channel RF coupled implant for paraplegic bladder control. A wide range of stimulation options may be selected by the use of control lines to CMOS analogue gates. Transdermal transmitters (Hartley oscillators) are driven by power amplifiers of virtually zero quiescent current. Overload protection circuitry which takes account of the pulsatile nature of the output, allows confident use of smaller power transistors than would be required for standard current limit or fold-back protection.