| 摘要 |
The invention relates to a frequency-variable pacemaker having a control device (10 to 15) for adapting the stimulation frequency. The pacemaker has a temperature sensor (4) by means of which the temperature of the venous blood in the heart (5) is measured. In order to permit a rapid response of the pacemaker to strains on the pacemaker wearer, an additional sensor, for example a motion sensor (13), is arranged which supplies a criterion for the loading of the pacemaker. This criterion is specified by a threshold value in accordance with which the heart rate is raised discontinuously to a discontinuous characteristic (step function response characteristic) (K3). Otherwise, the heart rate is controlled with the aid of characteristics which apply an assignment of the heart rate to the central venous blood temperature, specifically a rest characteristic (K2) which corresponds to a state of rest of the pacemaker and with the aid of load characteristics (K1) which proceed from a respective working point on the base characteristic (K2) and have a significantly higher gradient with respect to heart rate relative to temperature. The selection of the appropriate characteristics (K1, K2 or K3) is made by evaluating the pulses of the additional sensor (13). <IMAGE>
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