Abstract: A medical system including an implantable battery operated therapy device and an external communication device configured for wireless communication in a manner to minimize energy consumption in the implanted device. The medical device is configured to wake periodically from a sleep state to look for a message preamble from the communication device. The preamble is formatted to include control information, e.g., information indicating the time of receipt of the forthcoming message.

Abstract: A medical system comprising an implantable medical device and an external controller. The medical device includes a therapy administration subsystem, a telemetry subsystem, and a control subsystem which includes a microprocessor operable in response to data and/or code provided via said telemetry subsystem for producing an output signal for controlling said therapy administration subsystem. The controller includes a user input means and a telemetry subsystem responsive to said user input means for communicating data and/or code to said medical device telemetry subsystem. The medical device control subsystem includes program means for causing said microprocessor to separately execute at least two software processes to respectively produce separate therapy control output components. Combinatorial logic means responds to the separate output components to produce the output signal for controlling the therapy administration subsystem.