Patent ID: 6671528
Filing Date: 2003-12-30
Classification: A61B

Abstract:
An apparatus for determining a desired biologic constituent concentration of the blood of a patient, the blood 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 apparatus comprising:a fixture for holding the body part containing the blood conduit; an optical array having a plurality of spaced emitters and a detector positioned within the fixture and adapted to make contact with the body part with each emitter being located a different distance from the detector, the emitters each emitting a directed radiation that passes through both the blood conduit and the blood flowing therein, and the detector detecting the radiation from each emitter after the radiation has passed through the blood conduit and the blood flowing therein; a volume altering device positioned within the fixture for altering the blood flow within the body part; an energy transducer positioned within the fixture for detecting energy from the flowing blood within the blood conduit, the energy transducer for measuring the time rate of change of the blood volume, 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 which varies with the normalized blood changes of the pulsatile blood; and a calculator operating on the detected energy from the plurality of emitters and the transduced energy to determine the desired biologic constituent.