Medical device and method for estimating time between voltage levels of a power source

A method comprising:

• sensing a physiological signal;
• delivering a therapy based on at least the sensed physiological signal;
• storing a power capacity difference between a first voltage of a power source and a second voltage of the power source;
• measuring a voltage of the power source;
• determining that the measured voltage of the power source has reached the first voltage;
• determining an elapsed time since the measured voltage reached the first voltage;
• determining a current drain required from the power source for at least sensing the physiological signal;
• determining an estimated power source longevity based on the current drain and the power capacity difference;
• adjusting the estimated power source longevity by the elapsed time;
• generating an output based on the adjusted estimated power source longevity;
• and
• storing data corresponding to the adjusted estimated power source longevity in response to the generated output.

A non-transitory computer readable medium storing a power capacity difference between a first voltage of a power source and a second voltage of the power source and storing a set of instructions that, when executed by control circuitry of a medical device system, cause the medical device system to:

• sense a physiological signal;
• deliver a therapy based on at least the sensed physiological signal;
• measure a voltage of the power source;
• determine that the measured voltage of the power source has reached the first voltage;
• determine an elapsed time since the measured voltage reached the first voltage;
• determine a current drain required from the power source for at least sensing the physiological signal;
• determine an estimated power source longevity based on the current drain and the power capacity difference;
• adjust the estimated power source longevity by the elapsed time;
• generate an output based on the adjusted estimated power source longevity;
• and
• store data corresponding to the adjusted estimated power source longevity in response to the generated output.