Patent ID: 7020506

Claim:
A non-invasive method for use in determining at least one desired characteristic of blood of a patient, the method comprising: (a) creating a condition of artificial blood kinetics at a measurement location in a patient's blood perfused fleshy medium and maintaining this condition for a certain time period; (b) applying an external electromagnetic field to the measurement location; (c) detecting a time response of the medium from at least a portion of the measurement location to said external electromagnetic field, the response including at least one of an acoustic response to illuminating incident light having a wavelength in a range where the scattering properties of blood are sensitive to light radiation or an impedance of the portion of the medium; (d) generating measured data indicative of time evolutions of the response of the medium over at least a part of said certain time period; (e) analyzing said measured data for determining at least one characteristic parameter derived from said time response of the medium, the characteristic parameter including at least one of an actual value of the time response at a certain moment, during said certain time period, chosen when the response attains its near asymptotic magnitude; and a parametric slope defined as a ratio between a first function depending on a time response of the medium corresponding to a first frequency of the external electromagnetic field or a second function depending on the time response of the medium corresponding to a second frequency; (f) providing predetermined reference data sensitive to patient individuality and indicative of the desired blood characteristic obtained by other independent method as a function of said at least one characteristic parameter; and (g) utilizing the determined characteristic parameter derived from said time response of the medium and said predetermined reference data for obtaining a value of the desired blood characteristic.