Patent ID: 6873865
Filing Date: 2005-03-29
Classification: A61B

Abstract:
1. Apparatus for determining a desired biologic constituent concentration of the blood of a patient when the blood is flowing in a pulsatile fashion in a body part of the patient so as to be subjectable to transcutaneous examination in the body part, the body part defining a blood conduit, the comprising: (a) a blood conduit receiver for receiving the blood conduit with the blood flowing therein; (b) radiation-directing means for directing radiation into the flowing blood within the blood conduit, the radiation-directing means being situated within the blood conduit receiver, the radiation defining a directed radiation comprising a first quantity of radiation at a chosen radiation wavelength that, when directed into the flowing blood within the blood conduit, has: (c) radiation-detecting means for detecting the portion of the directed radiation that passes through both the blood conduit and the flowing blood therein, the radiation-detecting means being situated within the blood conduit receiver, the detected portion of the directed radiation comprising a second quantity of radiation at the chosen radiation wavelength; (d) energy-detecting means for detecting energy from the flowing blood within the blood conduit and for measuring the time rate of change of blood volume, the energy-detecting means being situated within the blood conduit receiver, the energy defining a transduced energy comprising a quantity of energy which when detected from the flowing blood within the blood conduit, has a value that varies with the normalized change of the pulsatile blood; and (e) operating means for operating exclusively on the second quantity of the radiation and the transduced energy to determine the desired biologic constituent concentration.