Patent ID: 7623922

Claim:
A cardiac rhythm management (CRM) system, comprising: an implantable medical device including: a CRM module; and an implant telemetry module; and an external system; a programming module; and an external telemetry module, wherein the implant telemetry module and the external telemetry module each include a telemetry circuit including: an antenna; a transceiver coupled to the antenna, the transceiver including plurality of channels each representing a predetermined frequency band for data transmission between the implantable medical device and the external system; and a telemetry controller coupled to the transceiver, the telemetry controller configured to control a channel hopping including selecting an active channel from the plurality of channels on an approximately periodic basis, to control the data transmission using the active channel during a synchronous scan mode during which the channel hopping in the external system and the channel hopping in the implantable medical device are controlled to be synchronous, to start an asynchronous scan mode in response to an interruption of the data transmission resulting from using a plurality of active channels of the plurality of channels to transmit a data frame without success during the synchronous scan mode, and to restore the synchronization of the channel hopping in the external system and the channel hopping in the implantable medical device during the asynchronous scan mode.