Patent ID: 7239901
Filing Date: 2007-07-03
Classification: A61B

Abstract:
1. A spectrophotometric instrument; comprising: a source of measurement light signals having measurement light wavelengths; a probe having: reference signal optics coupled to the measurement light signal between the measurement light signal source and the tissue-engaging surface, for transmitting a reference light signal portion of the measurement light signal; a detector for generating electrical signals representative of the measurement light signals and the reference light signals; an optical path for coupling the measurement light signal from the receive fibers and the reference light signal portion from the reference signal optics to the detector; an optical path control for selectively allowing and preventing the reference light signal portion to the detector, whereby the detector can output a reference light sample value when the reference light signal portion is coupled to the detector, and the detector can output a measurement light sample value when the measurement light signal portion is coupled to the detector; and a processor for determining corrected measurement sample signals at each measurement light wavelength as a function of a no light signal, a current measurement signal plus a no light signal and a no light signal plus a current measurement signal plus a current reference signal.