Non-contact Measuring Method Of Pulse Wave Information Based On Conventional Video And Dynamic Laser Speckle

Non-contact optical measurement method of pulse wave information is a long distance measuring human body health information and identifying characteristics of living life technology,developing on the optical and computer technology of optical image inspection?laser speckle?interferometry et al.Non-contact measurement method of pulse wave,because of its advantages of no invasion,no contact with human skin directly,no expensive equipment et al,has a broad application prospect in the professional medical,personal health,living recognition,disaster assistance,technical investigation et al.This paper mainly researches the non-contact pulse wave information measuring method and extraction algorithm based on the analysis of the optical video and laser speckle video and the measured pulse wave parameters,which provides a new train of thought and perception approach for the non-contact measurement and perception of pulse wave parameters.Measured and extracted parameters of pulse wave include pulse wave frequency(heart rate)?pulse wave propagation delay and pulse wave form,.Comparing the pulse wave parameters,measured under different environment and body state,and theoretical data,it has confirmed the feasibility,accuracy and reliability of the measuring methods of pulse wave information based on optical video and laser speckle video.The main contents of this thesis are as follows:(1)The medical value and practical significance of pulse wave parameter measurement were system elaborated.The basic medical theory of pulse wave were introduced in detail through the basic concept of pulse wave,the forming principle and the pulse form,then the feature points of pulse form and line directions were system elaborated;PhotoPlethysmoGraphy,typical noninvasive measurement of pulse wave signal,was analyzed and the contact and non-contact method and basic principle of pulse wave frequency were analyzed.(2)The principle analysis and algorithm research of non-contact,automatic and intelligent human pulse wave frequency measurement were done.Pulse wave frequency of human body were fast measured accurately through analyzing the faint change information of face skin images collected by ordinary camera.It was put forward that the skin area is extracted automatically by the face detection algorithm and then weaken the complex background image;the skin area and background image were isolated by the algorithm of OTSU,then original target pixel information were extracted;Using image algorithm of corrosion and expansion to consolidate and ensure the accuracy of the skin area under testing,it has achieved fully automated and high robustness pulse wave frequency measurements that all the progress without artificial operation and face need not remain motionless.(3)The study and algorithm research of non-contact pulse wave delay measurement based on conventional video micro change were done.It was put forward that phase difference information of different human body skin were obtained by frequency domain analysis method,and then the phase difference caused by the pulse wave propagation to different parts of skin was transformed to the time delay.It has achieved the extraction of pulse wave propagation delay based on the analysis of the micro change video.And this method has measured the time delay of the pulse wave of different skin parts were analyzed under different environments and different states of human body.Analyzing the change trend of pulse wave delay data under different conditions and it was compared with the medical theory analysis.The results show that the method of measuring pulse wave delay gets its feasibility and accuracy.(4)The study and algorithm research of non-contact pulse form measurement based on conventional video micro change were done.Based on the micro change analysis of conventional video and the technology of video processing algorithm,video pixel differences between each frame image were obtained accurately through analyzing the video micro change caused by different wavelengths light absorption degree of hemoglobin in the blood vessel.And then a type of curve graphic which very similar to normal pulse wave was obtained by smoothing.The results have verified the accuracy and reliability of the measured pulse form.(5)The preliminary experiment research of pulse wave frequency based on dynamic change of laser speckle were done.Laser incident to the human bare skin,then dynamic laser speckle was generated.Speckle pattern was shoot continuously by the CCD camera at a certain frame rate.Pulse wave frequency was obtained through analyzing the brightness changes of per frame speckle image by MATLAB.The brightness level?morphological changes?intensity distribution and other special rules contain the biological activity information.Pulse wave frequency could be extracted through analyzing the data change rules of dynamic laser speckle.The results have verified the feasibility of pulse wave frequency measurement method based on dynamic laser speckle.