Patent ID: 6385471
Filing Date: 2002-05-07
Classification: A61B

Abstract:
A method for determining oxygen saturation of hemoglobin in arterial blood using signals received from a probe, which signals are indicative of the light absorption of arterial blood, which has pulsatile and non-pulsatile components, at each of a respective one of two light wavelengths, said method comprising the steps of:producing, in response to said signals received from said probe, a series of sets of data values, each of said sets including first and second data values, which are indicative of the light absorption of arterial blood at a respective one of said two light wavelengths; storing a plurality of said sets of first and second data values; computing a ratio of an effective optical extinction coefficient of said pulsatile component of said arterial blood at a first one of said two light wavelengths to an effective optical extinction coefficient of said pulsatile component of said arterial blood at a second one of said two light wavelengths, said ratio being determined by regression analysis of n data points, each data point corresponding with one of said stored plurality of sets of data values, wherein n is a positive integer greater than 2; and determining oxygen saturation of said hemoglobin using said ratio.