US 2005/0033129 A1 · Method, apparatus and system for removing motion artifacts from measurements of bodily parameters

Abstract

A method for removing motion artifacts from devices for sensing bodily parameters and apparatus and system for effecting same. The method includes analyzing segments of measured data representing bodily parameters and possibly noise from motion artifacts. Each segment of measured data may correspond to a single light signal transmitted and detected after transmission or reflection through bodily tissue. Each data segment is frequency analyzed to determine up to three candidate peaks for further analysis. Each of the up to three candidate frequencies may be filtered and various parameters associated with each of the up to three candidate frequencies are calculated. The best frequency, if one exists, is determined by arbitrating the candidate frequencies using the calculated parameters according to predefined criteria. If a best frequency is found, a pulse rate and SPO2 may be output. If a best frequency is not found, other, conventional techniques for calculating pulse rate and SpO2 may be used. The above method may be applied to red and infrared pulse oximetry signals prior to calculating pulse rate and/or pulsatile blood oxygen concentration. Apparatus and systems disclosed are configured to perform methods disclosed according to the invention.

Claims36

Dependent claims

A method of removing motion artifacts, comprising:

transforming a plurality of electrical signals representative of a plurality of attenuated light signals into frequency domain data;
identifying a plurality of candidate peaks from the frequency domain data;
eliminating candidate peaks from the plurality of candidate peaks such that no two of the plurality of candidate peaks comprise harmonics of one another;
filtering each of the plurality of candidate peaks;
developing selection parameters associated with each of the plurality of candidate peaks;
and
selecting a best frequency from at least some of the plurality of candidate peaks by employing at least some of the selection parameters.

4 more elements

A pulse oximeter including an input device, an output device, and a motion artifact analyzer, wherein the motion artifact analyzer comprises:

a processor for processing at least one computer program;
and
a memory operably coupled to the processor and storing the at least one computer program, the at least one computer program including instructions for implementing a method of removing motion artifacts, the method comprising:
acquiring a segment of red data by transforming an electrical signal representative of an attenuated red light signal;
acquiring a segment of infrared data by transforming an electrical signal representative of an attenuated infrared light signal;
transforming the segment of red data and the segment of infrared data into red frequency domain data and infrared frequency domain data, respectively;
identifying a plurality of candidate peaks from the red frequency domain data and the infrared frequency domain data;
eliminating harmonic frequencies from the plurality of candidate peaks such that no two of the plurality of candidate peaks comprise harmonics of one another;
filtering each of the plurality of candidate peaks;
developing selection parameters associated with each of the plurality of candidate peaks;
selecting a best frequency from at least some of the plurality of candidate peaks by employing at least some of the selection parameters;
and
repeating the above acts for a new segment of red data and a new segment of infrared data.

10 more elements

Dependencies are inferred from the claim text.

Method, apparatus and system for removing motion artifacts from measurements of bodily parameters

Life of this patent

Method, apparatus and system for removing motion artifacts from measurements of bodily parameters

Life of this patent

Abstract

Claims36