Patent ID: 7904168

Claim:
An implantable medical device (IMD) comprising: a physiological sensor providing an analog output; a sense amplifier operatively coupled to the sensor and providing an analog waveform indicative of the sensor output; a memory; an analog to digital converter (ADC) configured to receive the analog waveform and sample the waveform into digitized data; a predictive encoding module operatively coupled with the ADC to generate an encoded waveform data point for each of an equivalent data point from a subset of the digitized data; an entropy encoding module operatively coupled with the predictive encoding module and configured to replace an encoded waveform data point with a codeword for that data point responsive to a predetermined condition being met, wherein the codeword is stored into the memory responsive to when the predetermined condition being met and the encoded waveform data point is stored into the memory responsive to when the predetermined condition not being met; and a transceiver operatively coupled to the memory and configured to transmit the stored encoded waveform data points and codewords.