A Respiration Rate Monitoring Method Based on Photoplethysmography

Abstract

The invention discloses a method for monitoring respiration rate based on photoplethysmography, which is characterized in that it includes the following steps: firstly collect the photoplethysmogram digital signal of blood volume change in the skin surface microvascular bed of the measured part, and the signal is unfiltered Process the original photoplethysmogram signal containing respiratory information and with a sampling frequency of 500Hz and above; then preprocess the collected photoplethysmogram using mathematical morphology methods; then use the feature point positioning method to detect the volume of the preprocessed signal The peak point and valley point of each beat of the pulse wave; calculate the time interval variable of each beat and the difference variable between the intensity of the peak point and the valley point of each beat; finally perform breathing beat detection on the obtained time interval variable and amplitude variable , to calculate the respiration rate.

Description

technical field [0001] The invention relates to a digital signal processing method, in particular to a method for monitoring respiration rate based on photoelectric volumetric wave with high sampling rate. Background technique [0002] Photoplethysmography (Photoplethysmograph, PPG) is a non-invasive detection method that uses photoelectric conversion technology to measure blood volume changes in microvascular beds on the skin surface. Photoplethysmography based on this method has been widely used in the monitoring of blood oxygen saturation and heart rate. Due to the interaction and influence between different systems of the human body, respiratory movement will also cause changes in the peripheral circulation, so the photoplethysmographic signal can be used to realize respiratory monitoring. Compared with existing respiratory monitoring methods, such as thoracic impedance and mouth-nasal airflow, the respiratory monitoring based on photoplethysmographic technology is more...

AI Technical Summary

Problems solved by technology

Relatively speaking, the temperature drift of extremely low frequency is easier to eliminate, but the influence of the Meyer wave component that is very close to the respiratory frequency or even overlaps with each other on the respiratory wave cannot be ignored, especially when the frequencies of the two waveforms overlap, the filtering method It is difficult to extract two different waveforms in the same frequency band separately

Although the Chinese patent ZL03808327.2 points out the corresponding phase change characteristics of respiratory waves and Meyer waves, under the condition that two different waveforms are clearly obtained, it can be judged as respiratory waves or Meyer waves by the phase relationship, but this invention does not No clear technical solution is proposed on how to separate the two waveforms with frequency aliasing

On the other hand, when studying breath detection, it is considered that the breath information is only included in the baseline components below 0.5Hz extracted by filtering, and the breath research is limited to the baseline components

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