Patent ID: 8090432
Filing Date: 2012-01-03
Classification: A61B,A61N

Abstract:
1. A medical device for sensing cardiac events, comprising: a plurality of electrodes sensing cardiac signals utilized to identify a cardiac event; a plurality of light sources capable of emitting light at a plurality of wavelengths; a detector to detect the emitted light; and a processor configured to determine a plurality of light measurements in response to the emitted light detected by the detector, to determine an isobestic blood volume index in response to determined light measurements of the plurality of light measurements from a first light source of the plurality of light sources emitting light at an isobestic wavelength, to determine an oxygen index in response to a difference between a light measurement of the plurality of light measurements from a light source of the plurality of light sources emitting light at a non-isobestic wavelength and a product of the determined isobestic blood volume index and a correction factor determined for the non-isobestic wavelength, and to verify the identifying of the cardiac event in response to the determined isobestic blood volume index and the determined oxygen index.