Minimax filtering for pulse oximetry
First Claim
1. A method of filtering a pulse oximetry signal, comprising:
- inputting the pulse oximetry signal into filtering algorithms, wherein the filtering algorithms comprise pre-programmed weighting matrices that depend on one or more of a characteristic of a sensor, a patient measurement site, or a type of physiological data to be collected, and wherein the filtering algorithms comprise H∞
filter algorithms adapted to filter the pulse oximetry signal.
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Abstract
Methods and systems are provided for filtering a pulse oximetry signal without making assumptions on the noise statistics of the signal. A pulse oximeter may receive an energy signal proportional to an amount of light detected at the sensor. The energy signal may be converted and digitally processed to estimate physiological data. The pulse oximeter may include a processor configured to execute H∞ filtering algorithms to estimate physiological data without requiring the variances and/or distributions of measurement and process noise in the signal. In one or more embodiments, the pulse oximeter may also be configured to execute other filtering algorithms which update H∞ filtering algorithms based on the pulse oximetry signal.
77 Citations
19 Claims
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1. A method of filtering a pulse oximetry signal, comprising:
- inputting the pulse oximetry signal into filtering algorithms, wherein the filtering algorithms comprise pre-programmed weighting matrices that depend on one or more of a characteristic of a sensor, a patient measurement site, or a type of physiological data to be collected, and wherein the filtering algorithms comprise H∞
filter algorithms adapted to filter the pulse oximetry signal. - View Dependent Claims (2, 3, 4, 5)
- inputting the pulse oximetry signal into filtering algorithms, wherein the filtering algorithms comprise pre-programmed weighting matrices that depend on one or more of a characteristic of a sensor, a patient measurement site, or a type of physiological data to be collected, and wherein the filtering algorithms comprise H∞
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6. A pulse oximetry system comprising:
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a sensor configured to transmit light into and receive light from tissue, and further configured to output an analog signal based on the received light; an analog-to-digital converter configured to digitize the analog signal; and a digital filter configured to filter the digitized signal with H∞
filtering algorithms, wherein the filtering algorithms comprise pre-programmed weighting matrices that depend on one or more of a sensor characteristic, a patient measurement site, or a type of physiological data to be collected. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14)
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15. A pulse oximetry monitor comprising:
a processor configured to determine whether a pulse oximetry system has a stationary zero-mean noise distribution, to access one or more stored filtering algorithms, to select an H∞
filtering algorithm from the one or more stored filtering algorithms when the pulse oximetry system is determined not to have a stationary zero-mean noise distribution, and to execute the H∞
filtering algorithm on a pulse oximetry signal to minimize a maximum error in the pulse oximetry signal.- View Dependent Claims (16, 17, 18, 19)
Specification