Apparatus is disclosed for stabilizing the value of a parameter of the output pulses of a tissue stimulator, such as the magnitude of the current or the charge delivered in each output pulse to excite the cell membranes of the tissue to be stimulated. The apparatus measures the value of this parameter...http://www.google.com.au/patents/US5222494?utm_source=gb-gplus-sharePatent US5222494 - Implantable tissue stimulator output stabilization system
