System and method for monitoring respiratory rate and oxygen saturation

Inventors

Lange, Daniel H.

Assignees

Chronisense Medical Ltd

Abstract

A method and system for monitoring respiratory rate of a patient is provided. An example system includes a wearable device configured to be disposed around a wrist of the patient. The wearable device may include a gyroscope to measure a gyroscope signal indicative of a motion of the patient. The system may further include a processor communicatively coupled to the gyroscope. The processor can be configured to perform a spectral analysis of the gyroscope signal to obtain a spectrum in a pre-determined range. The pre-determined range may cover a normal respiratory rate range. The processor can be further configured to determine a position of a peak in the spectrum to obtain a value for the respiratory rate. The processor can be further configured to provide, based on the value of the respiratory rate, a message regarding a health status of the patient.

Core Innovation

The invention relates to an at-home wrist-worn system configured to monitor a patient’s respiratory rate and oxygen saturation. A wearable device is disposed around a wrist of the patient and includes a gyroscope providing a gyroscope signal indicative of a motion of the patient. The processor performs spectral analysis of the gyroscope signal to obtain a spectrum in a pre-determined range covering a normal respiratory rate range and determines a position of a peak in the spectrum to obtain a value for the respiratory rate.

The wearable device further includes a first optical sensor configured to measure, at a palmar surface of the wrist, a first red wavelength photoplethysmography (PPG) signal and a first infrared wavelength PPG signal. A second optical sensor measures, at a dorsal surface of the wrist, a second red wavelength PPG signal and a second infrared wavelength PPG signal. The processor determines a first ratio and a second ratio for obtaining oxygen saturation, determines a third ratio based on the first ratio and the second ratio, and determines a value of the oxygen saturation based on the third ratio.

The system provides, based on the value of the respiratory rate, a message regarding a health status of the patient, and also provides, based on the value of the oxygen saturation, a further message regarding the health status of the patient. The documented processing concepts include using averaged periodograms for spectral analysis and using a weighted fusion of the two ratios, where the third ratio is computed as R=αRa+(1−α)Rb and the weight α is determined as a function of signal quality metrics such as SNR/perfusion index.

Claims Coverage

The provided excerpt contains three independent claims (system, method, and non-transitory computer-readable storage medium). Across the independent claims, the main inventive features are the wrist-worn gyroscope spectral analysis for respiratory-rate peak detection in a pre-determined normal range, the use of red/infrared PPG at both palmar and dorsal wrist locations to derive oxygen-saturation ratios, and the generation of health-status messages based on respiratory rate and oxygen saturation.

Across the independent claims, the coverage centers on wrist-worn gyroscope spectral analysis to estimate respiratory rate by peak position within a normal respiratory-rate range, oxygen saturation estimation using red/infrared PPG measurements at palmar and dorsal wrist surfaces via first and second ratios combined into a third ratio, and generation of health-status messages based on both the respiratory rate value and the oxygen-saturation value.

Stated Advantages

Documented Applications

No documented applications found