| 摘要 |
PCT No. PCT/SE97/01239 Sec. 371 Date Feb. 12, 1999 Sec. 102(e) Date Feb. 12, 1999 PCT Filed Jul. 4, 1997 PCT Pub. No. WO98/06454 PCT Pub. Date Feb. 19, 1998A pacemaker has control circuits contained in an enclosure and a lead containing an electrical conductor connected to an electrode for delivering electrical stimulation pulses to a heart. The stretching of a wall in the ventricle, corresponding to adequate filling of the ventricle in the heart, is determined in order to identify a time of emitting the stimulation pulses. This stretching is measured indirectly by measurement of pressure in the ventricle using a pressure sensor disposed near the lead in the ventricle. The signal from the sensor is supplied via the lead to circuitry in the enclosure, wherein the signal is amplified and is supplied to an edge detector, which detects an increasing or positive edge of the signal. The edge detector compares the incoming signal with a threshold value, and when the pressure indicated by the signal increases so as to exceed the threshold value, the edge detector supplies a signal to the control circuit which, in turn, triggers the emission of a stimulation pulse from a pulse generator, with or without a delay. The aforementioned stretching can also be measured using a strain gauge or a distance sensor attached to the ventricle wall.
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