Patent ID: 6587704
Filing Date: 2003-07-01
Classification: A61B

Abstract:
A non-invasive method of optical measurements for determining at least one desired biochemical parameter of patient's blood, the method comprising the steps of:(a) providing reference data indicative of the at least one desired blood parameter as a function of at least two measurable parameters, wherein one of said at least two measurable parameters is derived from scattering spectral features of a patient's blood perfused fleshy medium and another of said at least two measurable parameters is indicative of artificial kinetics of optical characteristics of the patient's blood perfused fleshy medium; (b) creating a condition of artificial kinetics and maintaining this condition for a certain time tC, the condition of artificial kinetics being created by causing blood flow modulations imposed from upstream of a measurement location with respect to a normal blood flow direction in the medium and substantially not affecting a blood volume at the measurement location, said blood flow modulations resulting in dynamical changes of light response at the measurement location to incident light; (c) applying optical measurements to the measurement location during a predetermined time period t including said certain time tC by illuminating the measurement location with incident light beams of different wavelengths in a red-NIR range, detecting the light responses T of the medium, and generating measured data in a form of time evolutions of the light responses T(t) of the medium at said measurement location for said different wavelengths, respectively, during said predetermined time period t; (d) analyzing the measured data for determining calculated values of said at least two measurable parameters; and (e) utilizing the calculated values and said reference data for determining a resulting value of the at least one desired blood parameter.