Study On Non-contact Measuring Method Of Human Heart Rate And Pulse Wave Based On Bio-speckle

Bio-speckle measurement technology is a new and developing optical measure-ment technology with full field,non-contact,high precision,easy operation,and low cost.With the development of optoelectronic technology and digital image processing technology in recent years,bio-speckle measurement technology has been paid wide attention and applied to various fields such as medical diagnosis,living detection,health monitoring and disaster relief.The non-contact measurement of human heart rate and pulse wave based on dynamic bio-speckle has the characteristics of non-contact,high precision,and simple equipment,which compensates for the shortcomings of direct contact with skin in traditional medical measurement technologies.The non-contact measurement of human heart rate and pulse wave based on dynamic biological speckles has great significance in human health monitoring and medical treatment.In this dissertation,the non-contact measurement of human heart rate and pulse wave using dynamic bio-speckles has been explored and studied.We combined the experiment basic principle analysis,the collection and processing of speckle images and the experimental measurement results analysis and verification.Through the experimental measurement,the average heart rate and the instantaneous heart rate information of the measured human body has been obtained,and the pulse waveform of the measured human body has been reconstructed.The feasibility,accuracy,reliability,and robustness of non-contact bio-speckle measurement of human heart rate and pulse wave were verified in many aspects.The main work of this paper is summarized as follows:(1)The development history of human heart rate measurement in the traditional medicine and the development status of non-contact heart rate measurement technology were introduced in detail.We also summarized the development of modern optical measurement technology and its application in heart rate and pulse wave measurement.(2)A detailed analysis of laser speckle generation principle,laser speckle classification and mathematical description were performed.The horizontal and vertical size of speckle particles were estimated.The formation mechanism of bio-speckle and several image processing algorithms for bio-speckle image processing were introduced.(3)The basic principle of laser speckle non-contact measurement of human heart rate and pulse wave were explained.The results of image processing algorithms such as gray value method,centroid method,digital speckle correlation method and other methods on dynamic bio-speckle image processing were compared and analyzed,and we finally chose the digital speckle correlation algorithm for follow-up experimental bio-speckle video data processing.(4)Non-contact bio-speckle measurement of average heart rate and pulse wave was performed.Firstly the basic principles and experimental procedures of the experiment were analyzed.In the collection of digital speckle images we mainly introduced how to improve the quality of dynamic bio-speckle image.Digital speckle correlation algo-rithm was used in the processing of speckle video.Fourier analysis was performed on the correlation coefficient signal between two adjacent frames of speckle video to extract the average heart rate and pulse wave from the spectrogram.The accuracy,reliability,and robustness of non-contact bio-speckle measurements were verified by comparison with the results of blood oxygen probe measurement.(5)Bio-speckle non-contact measurement of the human body's instantaneous heart rate was performed.In the processing of digital speckle image data,a time-domain auto-correlation algorithm was proposed for the original cross-correlation signal.Through the analysis of the peak point position of the autocorrelation coefficient curve we can calculate the instantaneous heart rate changes.The accuracy,reliability and robustness of the speckle measurement were verified by experimental measurements under various conditions.Finally,the measurement errors that may exist in the experiment were analyzed and the methods to avoid or reduce the measurement error were given.