Apparatus and method to discriminate between telemetry downlink signals and noise in an implanted device

An implantable medical device (IMD) comprising:

• a telemetry processing circuit;
• a configuration control circuit coupled to the telemetry processing circuit and adapted to manage configuration parameters that define operation of the IMD;
• and
• a receiver circuit adapted to discriminate between noise and a data signal in received radio frequency (RF) signals, communicate the data signal to the telemetry processing circuit and attenuate noise,
• wherein the receiver circuit is further adapted to operate in a relatively low power mode when not receiving RF signals and operate in a relatively higher power mode when receiving RF signals, and the telemetry processing circuit is further adapted to operate in a relatively low power mode when not receiving the data signal and operate in a relatively higher power mode when receiving the data signal.

A receiver circuit for an implantable medical device (IMD) adapted to discriminate between noise and a radio frequency signal received from an external IMD programmer, the receiver circuit comprising:

• a converter circuit adapted to generate a digital signal from a received radio frequency signal;
• counter circuit coupled to the converter circuit and adapted to count a number of edges of the digital signal occurring within a first selected time period;
• and
• a decoder circuit coupled to the counter circuit adapted compare the number of edges counted with a valid range, the decoder circuit further adapted to decode the digital signal and transmit a decoded signal to a telemetry processor of the IMD responsive to comparison of the number of counted edges with the valid range.

A receiver circuit for an implantable medical device (IMD) adapted to discriminate between noise and a radio frequency signal received from an external IMD programmer, the receiver circuit comprising:

• a converter circuit adapted to generate a digital signal from a received radio frequency signal;
• a plurality of counter circuits coupled to the converter circuit and adapted to count respective numbers of edges of the digital signal occurring within equal time periods that are offset one from another by a selected interval;
• a plurality of decoder circuits respectively coupled to the counter circuits and adapted to compare the respective numbers of edges counted with a valid range, each decoder circuit further adapted to generate, responsive to the number of edges counted, output signals indicating whether the digital signal contains valid data and data from the digital signal;
• and
• a data encoder coupled to the plurality of decoder circuits, the data encoder adapted to determine whether the digital signal contains valid data responsive to the output signals from the plurality of decoder circuits and output a data signal if data is present and the data being ignored by the receiver circuit if found not be valid.

A method of operating an implantable medical device (IMD), in response to a radio frequency (RF) signal, the method comprising:

• operating the IMD in a first power mode while not receiving the RF signal, the first power mode being a relatively low power mode;
• operating the IMD in a second power mode responsive to receiving the RF signal, the second power mode being relatively higher than the first power mode;
• and
• operating the IMD in a third power mode responsive an average frequency of the RF signal over at least one selected time period being within a predetermined range, the third power mode being relatively higher than the second power mode.