A method is provided for monitoring the status of a medical device implanted in a patient. The method includes the steps of implanting in a patient a medical device which comprises (i) a substrate in which two or more reservoirs are located, with each covered by a reservoir cap, (ii) a drug or sensor located in the reservoir, (iii) a power source and actuation electronics for disintegrating or permeabilizing the reservoir cap, and (iv) a telemetry system; and then using said telemetry system to wirelessly transmit to a remote controller data about the condition of the power source and/or data about which reservoirs have been or have yet to be activated to release the drug therefrom or to expose the sensor therein.