A rate-responsive pacemaker which includes a conventional programmable pulse generator, a physiological sensor, and a processor is disclosed which generates heart stimulation pulses on demand, or as otherwise programmed, as controlled by a rate control signal which is derived from the physiological sensor....http://www.google.de/patents/US4940052?utm_source=gb-gplus-sharePatent US4940052 - Microprocessor controlled rate-responsive pacemaker having automatic rate response threshold adjustment
