Research And Implementation Of Non-Contact Cardiopulmonary Signal Monitoring System Based On Optical Fiber Sensing

Cardiopulmonary signals are an extremely important part of vital signs,and the implementation of at-home monitoring of cardiopulmonary signals can help provide early warning of related cardiovascular and respiratory diseases.With the accelerating aging of our population,China has become the country with the largest elderly population in the world.At the same time,modern society has brought enormous pressure on young people’s lives,and the number of young people in a sub healthy state is gradually increasing.These people need a convenient and accurate means to monitor their own health status at home so that they can detect health abnormalities in advance and receive timely treatment.Based on this background,this paper has been commissioned by an enterprise to study a fiber optic sensing system for cardiopulmonary signal monitoring.In order to meet the needs of home-based cardiopulmonary signal monitoring with convenient operation and high accuracy,monitoring equipment is required to collect and analyze cardiopulmonary signals in a safe,non-sensing,and comfortable scenario.In this paper,the non-contact cardiopulmonary signal sensing is realized by an optical fiber sensor based on the principle of single-mode fiber macrobending loss,and the hardware circuit for signal conditioning and acquisition is designed according to the characteristics of the sensing signal,the cardiopulmonary signal processing algorithm is studied,the data display host computer is designed,and a fiber-optic transmissionbased signal is constructed.Cardiopulmonary signal monitoring system with sensor technology.The main research contents are as follows:(1)Research on cardiopulmonary signal sensing method based on optical fiber macrobend.Analyze the basic principles of single-mode fiber structure and optical conduction characteristics,study the macrobending loss sensing principle of singlemode fiber,and design a fiber-optic macrobend sensing pad for cardiopulmonary signal sensing;Cardiopulmonary signal sensing principles and signal characteristics;Build a cardiorespiratory signal dataset for signal processing.(2)Cardiopulmonary signal processing algorithm research.Research the cardiopulmonary signal preprocessing algorithm,analyze the characteristics of the cardiopulmonary signal,and design a method for judging sensing states such as in-bed,out-of-bed,and body motion;research on the cardiopulmonary signal noise reduction algorithm;In order to solve problems such as missing frequency of cardiac cycle,an improved envelope decomposition and multi-modal fusion algorithm based on variational modal decomposition is designed to extract the heartbeat cycle and respiratory cycle;an adaptive threshold peak-finding algorithm is designed to identify the peak value of the heartbeat signal and the respiratory signal.,complete the monitoring of the two vital signs of heart rate and breathing rate.(3)Realization of cardiopulmonary signal monitoring system and system performance test and analysis.Complete the hardware design and embedded software development of the cardiopulmonary signal system,realize the digitization of the cardiopulmonary signal collected by the optical fiber macrobend sensing pad,and design the host computer program for data display based on MATLAB to realize the construction of the cardiopulmonary signal monitoring system;design the cardiopulmonary signal monitoring system Experiments such as functional test,heart rate monitoring performance test,respiratory rate monitoring performance test,and overnight sleep monitoring test verify the accuracy and effectiveness of the cardiopulmonary signaling system studied in this paper.The test results show that the average error of monitoring the heart rate of this system is 0.56±0.41 bpm,and the average error of monitoring the respiratory rate is 0.47±0.48 bpm.