Patent ID: 7630078
Filing Date: 2009-12-08
Classification: A61B,A61N

Abstract:
1. A method for compensating for changes in intensity of light transmitted by a light source of an implantable system that includes an implantable housing including a window through which light can pass; a light source, within the housing, that transmits light, wherein a portion of the light exits the housing through the window; and a measurement light detector, within the housing, to detect light scattered back into the housing through the window, and to produce a measurement signal that is indicative of the intensity of the light detected by the measurement light detector; the method comprising: (a) providing a calibration light detector within the housing to detect a portion of the light that has not exited the housing, and to produce a calibration signal indicative of the intensity of the light detected by the calibration light detector, which is indicative of the intensity of the light transmitted by the light source; (b) producing calibration measurements based on the calibration signal; (c) using the calibration measurements to perform calibrations that compensate for changes in the intensity of light transmitted by the light source; and (d) between consecutive calibration measurements, predicting a metric indicative of a change in the intensity of the light since a most recent calibration measurement, and using the predicted metric to perform a calibration that compensates for predicted depletion in the intensity of light transmitted by the light source.