| 摘要 |
A cardiac pacemaker is disclosed having means for automatically adjusting the rate of operation to correspond to physiological changes. Circuitry is provided for detecting the presence or absence of an evoked T wave following a delivered stimulus pulse, and for measuring the time interval between the stimulus pulse and the following T wave. The escape interval of the pacemaker pulse generator is varied in accordance with the detected stimulus - T interval and in the same direction, so as to vary the pacing rate in accordance with variations in such interval. Since this interval in turn corresponds to physiological changes, the pacemaker is adapted to automatically follow the patient's physiological changes. When an evoked T wave is absent following a delivered stimulus pulse the pacer stimulus generator is adjusted for delivery of a pacing signal of greater energy. Circuitry is also provided for lowering the pacing energy level in response to external signals, whereby threshold testing may be achieved. |
