Detection Method Of Human Respiration And Heartbeat Signal Based On UWB Radar System

At present,with the continuous development of radar technology,radar application fields are becoming more and more widely.The detection method of human respiration and heartbeat signal based on UWB radar system is in a certain area,separated by certain media(such as walls,clothing,etc.),and The technology to detect and extract the human body's respiration and heartbeat signals without touching the measured target.This technology has the advantages of remote monitoring,strong penetration,strong anti-interference ability,high precision,and non-contact.It has a wide range of applications in medical testing,rescue search,through-wall testing,modern warfare and daily family monitoring.However,the non-contact human respiration and heartbeat detection radar system still has some problems that need to be solved.For example,because the UWB radar system will be interfered by the noise of the external environment,and the strength of the human respiration and heartbeat signal is weak,it will cause the signal received by the radar.The randomness is strong,which increases the difficulty of extracting the respiratory and heartbeat signals from the echo signals with low signal-to-noise ratio;select the appropriate algorithm to process the echo signals in real time so as to detect the vital signs information of the measured object in real time and long-term.In order to accurately collect the respiratory and heartbeat signals of the measured object,it is very important to denoise the echo signal and extract the respiratory and heartbeat information.This article will focus on the research on the extraction of respiratory and heartbeat information from the target echo signal.This article mainly starts with the construction of a complete UWB radar hardware system and the extraction algorithm of respiration and heartbeat signals.According to the actual situation and combined with the above problems,related research is carried out.The specific work is as follows:The working principle of the UWB radar hardware system is analyzed in detail,and the corresponding parameters of the radar system are calculated,the circuit diagram and PCB are designed,and the appropriate antenna,main control chip(signal processing chip),signal generation module,and power are selected.Amplifiers,power dividers,analog-to-digital conversion chips and other related components.A complete UWB radar hardware system for respiratory and heartbeat detection has been established.Aiming at the problem of low signal-to-noise ratio of target echo signals,a signal-echo de-skew receiving model is established,and a method of mean filtering is proposed,and the signal-to-noise ratio is improved through coherent accumulation.Then use MATLAB to verify the effectiveness of the method.For non-contact respiration and heartbeat detection,the human body's fretting energy caused by respiration is far greater than the human body's fretting energy caused by heartbeat.Because the radar echo signal is the result of the combined action of respiration and heartbeat,the respiration signal and heartbeat The signals will overlap in the frequency spectrum.This paper uses weighted sparse reconstruction and OMP algorithm to decompose the echo signal.And the effectiveness of the method is verified by MATLAB.Finally,through actual experiments,let the radar system collect the respiration and heartbeat signals of normal people,and use the above-mentioned algorithm to process the echo signals,so that better respiration and heartbeat signals can be obtained.In order to ensure the accuracy and objectivity of the experiment,multiple experiments were carried out in the follow-up,and the frequency error of the experimental results was all within the error range.