Patent ID: 7881802

Claim:
An implantable device comprising: at least two telemetry circuits including a first telemetry circuit and a second telemetry circuit, each telemetry circuit configured to wirelessly communicate with an external device; and a controller coupled to each telemetry circuit, the controller configured to, after a communication session is established: operate a selected one of the first or second telemetry circuits in a synchronous state in which the telemetry circuit recurrently transmits data synchronized with a received synchronization signal associated with the selected telemetry circuit until the selected telemetry circuit detects loss of the synchronization signal; and operate the first and second telemetry circuits in an out-of-synchronization state, upon detection of the loss of the synchronization signal and before the communication session terminates, in which the implantable device monitors for both a synchronization signal associated with the first telemetry circuit and a synchronization signal associated with the second telemetry circuit and in which receipt of the synchronization signal associated with the first telemetry circuit causes the first telemetry circuit to transition to the synchronous state and in which receipt of the synchronization signal associated with the second telemetry circuit causes the second telemetry circuit to transition to the synchronous state, wherein the first telemetry circuit and second telemetry circuit are configured to recurrently transition to the out-of-synchronization state upon detecting loss of the associated synchronization signal before termination of the communication session.