摘要 |
<p>There is provided an implantable device with two or more output stages for delivering concurrent output pulses to two or more sites within a patient's body. Each output circuit has a common architecture, including a switchable generator 41,51 which has a plurality of storage capacitors and switches for arranging the capacitors either to be charged by the battery 62, or to discharge a stimulus pulse. A programmable regulator 43,53 is provided for further regulation of the output voltage; and a multiplexer connects the output to the desired electrodes placed at the patient site. For concurrent dual pulse-dual site stimulation, a pair of active rectifier switches are connected between the negative terminal of each output stage and the battery positive terminal, whereby at the time of concurrent pulse delivery, the output stage having the greatest voltage developed thereacross has its negative terminal connected to the battery plus terminal, while the other output stage is disconnected from the battery so that it floats. This arrangement reduces crosstalk current while ensuring continued positive biasing of the semi-conductor switches in each output stage. <IMAGE></p> |