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Research On Non-contact Heart Rate Monitoring Technology Based On Adaptive Decomposition And Weighted Reconstruction

Posted on:2024-02-13Degree:MasterType:Thesis
Country:ChinaCandidate:R S SuFull Text:PDF
GTID:2530307058981949Subject:Engineering
Abstract/Summary:PDF Full Text Request
Heart rate has been widely used in the medical field as one of the main indicators to evaluate the health status of the human body.Traditional heart rate monitoring methods usually require the use of contact sensors,but this method cannot monitor heart rate for a long time and may be limited in some special cases.With the development of information technology,non-contact heart rate monitoring technology has gradually become popular in people’s daily life.Among them,radarbased heart rate monitoring technology has become one of the indispensable technologies in this field because of its advantages such as reliability and no privacy issues.However,stable and accurate heart rate monitoring remains a challenge due to the prevalence of respiratory harmonic interference in real scenarios.Based on frequency modulated continuous wave radar,this study proposes a new systematic method for heartbeat signal decomposition,reconstruction and heart rate estimation to suppress the interference of respiratory harmonics and other noises on heart rate monitoring,and verifies the feasibility and superiority of the method through experiments.In this paper,a set of signal processing algorithm process based on millimeter wave frequency modulated continuous wave radar is proposed,which can extract the subject’s heart rate accurately.First,the Fourier transform of the received radar intermediate frequency signal is performed to obtain the distance between the subject and the radar,and then the phase of the intermediate frequency signal at this distance is extracted to obtain the displacement signal of the subject’s thoracic wall initially,and then the noise reduction of the thoracic wall displacement signal is performed by the mean denoising method.Then,the second harmonic of the heartbeat was reconstructed by using the adaptive decomposition algorithm based on the KL(Kullback-Leible)divergence to decompose the displacement signal into a set of modal components,and then selecting the modal components within the second harmonic range of the heartbeat and weighting them according to their respective sample entropy.Finally,the heart rate is estimated and obtained using the ESPRIT(Estimation of Signal Parameters using Rotational Invariance Techniques)algorithm.In this paper,data acquisition was carried out by designing experimental scenarios and radar parameters,and the proposed algorithm flow was programmed and implemented and data analyzed.The experimental results show that the proposed algorithm effectively removes the higher harmonics of the respiratory signal and other noises,and achieves a high accuracy heart rate measurement.The accuracy and error of the proposed algorithm are evaluated by experimental comparison with the contact reference sensor and the signal processing and frequency estimation algorithms in previous work,i.e.,compared to previous work the accuracy of the proposed method in this paper is improved by about 10% and the error is reduced by about 5%,which has the advantage of higher accuracy and stability compared to the current advanced methods.In summary,this study proposes a novel systematic method for heartbeat signal decomposition,reconstruction and heart rate estimation based on millimeter wave frequency modulated continuous wave radar,and verifies its feasibility and superiority in experiments.The method has high accuracy and practicality,which can provide strong support for future research and application in the field of heart rate monitoring.
Keywords/Search Tags:Heart rate monitoring, FM continuous wave, Millimeter-wave radar, Non-Contact Vital Signs Monitoring
PDF Full Text Request
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