Patent ID: 6397092
Filing Date: 2002-05-28
Classification: A61B

Abstract:
A pulse oximeter, comprising:a first source for emitting light having a first spectral content; a second source for emitting light having a second spectral content different than said first spectral content; a drive system for pulsing each of said first and second sources such that said first and second sources output first and second optical signals, respectively, each of said first and second optical signals including a series of high output periods separated by low output periods, said drive system thereby defining a modulation waveform; a detector for receiving said first and second optical signals and providing a detector signal representative of said received first and second optical signals; and a digital sampler, operatively associated with said detector, for providing multiple digital values based on said detector signal corresponding to a single cycle state, said single cycle state being one of a single high output period and a single low output period of one of said first and second sources; and a processor for using said multiple digital values in performing processing steps related to determining an oxygen saturation related value, said processing steps including processing said multiple digital values to obtain modulation waveform information relating to a shape of said modulation waveform, said shape including a profile of a portion of said detector signal corresponding to said single cycle state, and using said modulation waveform information in determining said oxygen saturation related value.