Methods and systems for determining signal quality of a physiological signal
AssigneeCovidien LP
InventorsPaul Stanley Addison, James Nicholas Watson
Life of this patent
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Abstract
A physiological monitoring system may use photonic signals at one or more wavelengths to determine physiological parameters. The system may monitor a photoplethysmograph (PPG) signal, which may include a periodic component, and an aperiodic component. An attractor may be generated based on a first segment of the PPG signal and a second segment of the PPG signal shifted in time relative to the first segment by a time delay. The system may analyze points of the attractor that correspond to a curve, analyze the distribution of the attractor about a curve, or both, to determine a signal quality metric indicative of cycle to cycle variation in the PPG signal.
Claims22
A method for determining signal quality of a physiological signal, the method comprising:
- receiving a photoplethysmograph signal;
- specifying, using processing equipment, a first segment of the photoplethysmograph signal, wherein the first segment comprises a first plurality of sample values;
- specifying, using the processing equipment, a second segment of the photoplethysmograph signal based on a time delay relative to the first segment, wherein the second segment comprises a second plurality of sample values;
- associating, using the processing equipment, each sample value of the first segment with a corresponding sample value of the second segment to generate a plurality of associated value pairs;
- identifying, using the processing equipment, a subset of associated value pairs of the plurality of associated value pairs, wherein when the plurality of associated value pairs are considered in two-dimensional space, the subset of associated value pairs substantially correspond to a curve;
- and
- determining, using the processing equipment, a signal quality metric based on the subset of associated value pairs.
A method for determining signal quality of a physiological signal, the method comprising:
- receiving a photoplethysmograph signal;
- specifying, using processing equipment, a first segment of the photoplethysmograph signal, wherein the first segment comprises a first plurality of sample values;
- specifying, using the processing equipment, a second segment of the photoplethysmograph signal based on a time delay relative to the first segment, wherein the second segment comprises a second plurality of sample values;
- associating, using the processing equipment, each sample value of the first segment with a corresponding sample value of the second segment to generate a plurality of associated value pairs;
- determining, using the processing equipment, one or more metrics, wherein the one or more metrics are indicative of how the plurality of associated value pairs, when considered in two-dimensional space, are distributed about a curve;
- and
- determining, using the processing equipment, a signal quality metric based on the one or more metrics.
A system for determining signal quality of a physiological signal, the system comprising:
- processing equipment configured to:
- receive a photoplethysmograph signal;
- specify a first segment of the photoplethysmograph signal, wherein the first segment comprises a first plurality of sample values;
- specify a second segment of the photoplethysmograph signal based on a time delay relative to the first segment, wherein the second segment comprises a second plurality of sample values;
- associate each sample value of the first segment with a corresponding sample value of the second segment to generate a plurality of associated value pairs;
- identify a subset of associated value pairs of the plurality of associated value pairs, wherein when the plurality of associated value pairs are considered in two-dimensional space, the subset of associated value pairs substantially correspond to a curve;
- and
- determine a signal quality metric based on the subset of associated value pairs.
A system for determining signal quality of a physiological signal, the system comprising:
- processing equipment configured to:
- receive a photoplethysmograph signal;
- specify a first segment of the photoplethysmograph signal, wherein the first segment comprises a first plurality of sample values;
- specify a second segment of the photoplethysmograph signal based on a time delay relative to the first segment, wherein the second segment comprises a second plurality of sample values;
- associate each sample value of the first segment with a corresponding sample value of the second segment to generate a plurality of associated value pairs;
- determine one or more metrics, wherein the one or more metrics are indicative of how the plurality of associated value pairs, when considered in two-dimensional space, are distributed about a curve;
- and
- determine a signal quality metric based on the one or more metrics.
Dependencies are inferred from the claim text.