Relative phase estimation of harmonic frequency component of a plethysmographic waveform
First Claim
1. A method for use in a pulse oximetry system, comprising the steps of:
- obtaining an input signal representative of an optical signal potentially including physiological information based on interaction with a patient;
analyzing said input signal to identify first information related to a first portion of said signal corresponding to a first potential waveform feature of said input signal and second information related to a second portion of said signal corresponding to a second potential waveform feature of said input signal;
using said first information and said second information to determine a phase-related value; and
using said phase-related value to determine a quality of said input signal in relation to one of desired information content and artifact content.
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Accused Products
Abstract
Detector signals in a pulse oximeter are analyzed to determine a quality of the signals in relation to desired information content or artifact content. The analysis involves performing a transform on a signal to obtain frequency related information and analyzing the frequency related information to obtain a value independent of a shape and waveform of a spectrum of the time-based signal. The analysis involves consideration of the relative phase of the fundamental and harmonic components of a signal. Signals including desired physiological information can be distinguished from artifact affected signals. Based on this analysis, signals can be validated or an appropriate processing algorithm can be selected.
71 Citations
18 Claims
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1. A method for use in a pulse oximetry system, comprising the steps of:
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obtaining an input signal representative of an optical signal potentially including physiological information based on interaction with a patient;
analyzing said input signal to identify first information related to a first portion of said signal corresponding to a first potential waveform feature of said input signal and second information related to a second portion of said signal corresponding to a second potential waveform feature of said input signal;
using said first information and said second information to determine a phase-related value; and
using said phase-related value to determine a quality of said input signal in relation to one of desired information content and artifact content. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for use in a pulse oximetry system, comprising the steps of:
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obtaining a time-based signal representative of an optical signal potentially including physiological information based on interaction with a patient;
first performing a transform on said time-based signal to obtain first phase information for a first component of said time-based signal and second phase information corresponding to a second component of said time-based signal; and
using said first and second phase information to determine a quality of said time-based signal in relation to one of physiological information content and artifact content. - View Dependent Claims (10, 11, 12, 13)
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14. A pulse oximetry apparatus, comprising:
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an input port for obtaining a time-based signal representative of an optical signal potentially including physiological information based on interaction with a patient; and
a processor for performing a transform on a time-based signal to obtain first phase related information corresponding to a first component of said time-based signal and second phase related information corresponding to a second component of said time-based signal, and for using said first and second phase related information to determine a quality of said time-based signal in relation to one of physiological information content and artifact content. - View Dependent Claims (15, 16, 17, 18)
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Specification