An implantable medical device system including an optical sensor monitors for the presence of overgrowth on the sensor by sensing light scattered by a measurement volume, the sensed light corresponding to a first wavelength, and deriving an overgrowth metric in response to the sensed light. The overgrowth...http://www.google.ca/patents/US8170636?utm_source=gb-gplus-sharePatent US8170636 - Optical sensor confidence algorithm
