| 摘要 |
<p>EXTERNALLY-RESET TACHYCARDIA CONTROL PACER There is disclosed an improved pacer for controlling tachycardia. By placing a magnet over the patient's chest in the vicinity of a conventional prior art heart pacer, a reed switch may be closed to cause the pacer to generate pulses at a continuous rate which reflects the battery potential. But this technique cannot be used in a tachycardia control pacer because it is not designed to generate continuous pulses. In the tachycardia control pacer of the invention, placing a magnet over the patient's chest results in the generation of two pulses, the time separation between which is an indication of the battery potential. Application of the magnet in this way also holds the device off, after the two pulses are generated, so that if the device is causing him discomfort the patient can temporarily disable it until the physician can program it off. The illustrative tachycardia control pacer generates two pulses during each cycle of operation at times which are "scanned" from cycle to cycle. Successful time parameters are retained so that any scanning which follows tachycardia confirmation begins with the values which were successful in terminating the previous tachycardia episode. Application of a magnet to the patient's chest, or programming of the device, resets the two time intervals to the values programmed by the physician. The next scanning begins with the programmed time values. In this way the physician, after inducing tachycardia, can verify the programmed time parameters rapidly by observing the patient's ECG waveform, without having to wait several minutes until scanning from the previously retained successful values would otherwise progress to the programmed values.</p> |
