METHOD AND APPARATUS FOR DETERMINING CEREBRAL OXYGEN SATURATION

摘要

A new and improved method and apparatus for determining cerebral oxygenation are disclosed. In one basic aspect, a small portion of an input photon burst from a laser(12) is injected into the head. The photon detection fiber optic (44, 144) collects the photons and sends them to the shuttered detector (22, 24). With the shuttered detector (22, 24), the time-based photon quantity determinations of the wavelength-specific light may be significantly improved, and simplified, by determining the quantity of returning photons in at least one set of two different but closely spaced points in time following the instant of injection, and then taking the ratio of the determinations in each set, to thereby cancel and remove several important sources of error.