Patent ID: 8611975

Claim:
Apparatus for non-invasive measurement of a substance within a body, the apparatus comprising: a detector for sensing radiation emitted or remitted from a body; optics configured to focus the radiation on a sensitive area of the detector; a baffle attached to and in thermal contact with the detector, the baffle being disposed to at least partially surround a detector sensitive area and configured to minimize the incidence of stray radiation on the detector sensitive area, wherein an interior surface of the baffle opposite the detector has a high reflectivity and low emissivity, the interior surface of the baffle being formed to minimize the incidence of radiation reflection or multi-reflection on the detector sensitive area, and wherein the interior surface of the baffle constitutes a portion of a sphere surrounding the detector, a portion of the baffle above and opposite the sensitive area of the detector having an opening allowing the radiation to reach the sensitive area of the detector.