Systems and methods for determining respiration information from a physiological signal using amplitude demodulation

摘要

A patient monitoring system may receive a physiological signal such as a photoplethysmograph (PPG) signal. The PPG signal may include a pulsatile component that functions as a carrier signal and an amplitude modulation component that represents respiration information. The patient monitoring system may move the amplitude modulation component to a baseline component of the PPG signal. Respiration information may be calculated based on the amplitude modulation component.

主权项

1. A method for determining respiration rate for a patient, the method comprising:
receiving a photoplethysmograph (PPG) signal from a pulse oximetry sensor that is configured to photoelectrically sense absorption of light in tissue of the patient, wherein the PPG signal includes an amplitude modulation component caused at least in part by respiration; processing, using a processor, the PPG signal to move the amplitude modulation component into a baseline component of the PPG signal to generate a processed PPG signal, wherein the processing of the PPG signal comprises:
identifying a frequency and phase associated with a pulsatile component of the PPG signal;generating a matched signal based on the identified frequency and phase; andmixing the PPG signal with the matched signal; and analyzing, using the processor, the processed PPG signal to determine the respiration rate of the patient based on the amplitude modulation component.