Patent ID: 6993372
Filing Date: 2006-01-31
Classification: A61B

Abstract:
1. A method for use in non-invasive optical measurements in a patient's body, 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, the creation of the artificial blood kinetics comprising applying primary over-systolic pressure to achieve a state of temporary blood flow cessation in the medium at the measurement location, the primary over-systolic pressure being applied either to a certain location upstream of the measurement location with respect to a normal blood flow direction in the medium or to the vicinity of the measurement location; (b) altering said condition of artificial blood kinetics at the measurement location over a predetermined time interval within said certain time period so as to modulate an optical response by changing scattering properties of blood, said altering of the condition of artificial blood kinetics including applying a perturbation to the medium by at least one secondary pressure pulse of a predetermined value over said predetermined time interval; and (c) applying optical measurements to the measurement location by illuminating the measurement location with incident light beams of at least two different wavelengths in a range where the light radiation is sensitive to scattering properties of blood, detecting light responses of the medium, and generating measured data indicative of time evolutions of the light responses of the medium for said at least two different wavelengths, respectively, over at least a part of said predetermined time interval.