| 摘要 |
A method of determining recommended replacement time, RRT, of a battery of an implantable medical device comprises the steps of measuring the battery's internal impedance, comparing the measured impedane with a predetermined limit value and determining RRT from the result of this comparison. The limit value is hanged in response to hanges of operating conditions affecting the current consumption of the medical device. A circuit for determining RRT of an implantable heart stimulator having a battery includes an impedane measurement means (12) for measuring the internal impedance of the stimulation battery (6), a comparator means (14) for comparing the measured internal impedance with a predetermined limit value, and a determining means (16, 23) for determining RRT from the result of this comparison. A limit value hanging means (15) is provided to automatically change the limit value of the comparator means in response to changes of operating conditions affecting the current consumption of the heart stimulator. |
