Pulse oximeter with improved accuracy and response time

Claim 1

A pulse oximeter for measuring and displaying average oxygen saturation levels present in pulsating blood flow in a living person, comprising: light directing means for directing light having a first wavelength and light having a second wavelength, towards a tissue sample carrying a pulsating blood flow; light detection means for detecting the light of said first and second wavelengths, after passage through said tissue sample, and for generating, in response thereto, a first analog electrical signal related to said first wavelength, and a second analog electrical signal related to said second wavelength; signal conversion means for converting said first and second analog electrical signals, into first and second digital signals, respectively; computer processing means for processing said first and second digital signals so as to compute, for each pulsation in said pulsating blood flow, (i) an oxygen saturation level data element, and (ii) an associated data element containing pulse time interval data and/or artefact data; storage means for storing said oxygen saturation level data elements and said associated data elements computed over a predetermined period of time; data element validation means for selectively validating certain of said oxygen saturation level data elements using said associated data elements, so as to produce validated oxygen saturation level data elements for use in computing average oxygen saturation levels for visual display; and data element averaging means for averaging a selected number of said validated oxygen saturation level data elements so as to produce data representative of an average oxygen saturation level; and display means for visually displaying said average oxygen saturation levels for use in monitoring said living person.