Pulse Wave Information Detection And Analysis Method Research

Pulse signal is a common biomedical signal, the characteristics of the pulse wave signal reflects the status information of human cardiovascular physiology. Pulse signal detection and analysis are concerned in the medical zone, accurate and effective pulse wave signal detection and analysis of the human cardiovascular system health monitoring and disease diagnosis has important clinical significance. In this paper, we carried out contact and non-contact pulse wave information detection and analysis method research .In the contact detection and analysis, we have designed a novel contacting pulse signal detection system using embedded microprocessor control technology. The main functional units of the system have been developed which consist of signal conditioning module,MCU module,PC data acquisition module and data display and analysis module. This system can be applied to acquire the pulse signals of the human dynamically and real-time display the signals, and implement data storage, playback and data analysis.We detected and calculated the time domain and frequency domain of the pulse wave. In the non-contact detection and analysis method, we also have designed a pulse wave information detection and analysis system based on infrared sequence image, propose a novel method to detect and calculate blood vessel elasticity based on infrared sequence images. We have applicated the detection and analysis system getting the infrared sequence images of the radial artery, and establish a sequence image processing algorithms. We use the image processing algorithm to extract time series signal in the sequence images reflecting the pulse wave characteristics. We define a kind of blood vessel elasticity parameter. We complete calculation for the blood vessel elasticity on the base of the time series signal. The pulse wave detection system uses non-contact manner detecting pulse wave information, can obtain pulse wave characteristics in the natural physiological state. It also provides a novel method for the detection and analysis of blood vessel elasticity, have good value in clinical application, especially provide a more comprehensive diagnostic information for Chinese medicine pulse diagnosis.The research work in this paper can be summed up as follows: (1) Choose an integrated sensor based on PVDF piezoelectricity membrane to gather the pulse signal. In order to implement the collection of the pulse signal, we design an analog modulation circuit of pulse signal. Plus the A/D switching, RS-232 serial communication between the MCU and the PC base on single chip microcomputer. The PC is used as upper computer, We exploit a system of receiving and displaying of pulse signal by LabVIEW.(2) Using multi-scale and multi-resolution feature of wavelet transform, the pulse signal is decomposed as multi-scale,so the effective signals and noise signals at different time scales show different frequency characteristics, which reveals the difference between them. Then the corresponding rules ale constructed depending on these differences to realize threshold filtering process for the wavelet coefficients of signal which contain noise.(3) The FFT algorithm is analyzed and the FFT algorithm is applied to processing of pulse signal, converting the pulse signal from time domain to frequency domain. The frequency spectrum and features of pulse signal are obtained.(4) Study on power spectrum estimation of pulse signal is done and the features of the power spectrum are extracted by using the self-correlation method.(5) Construct a non-contact pulse wave information detection analysis system on the base of infrared sequences image, achieve the dynamic acquisition of infrared image at the radial artery.(6) Establish a sequence image processing algorithm, extract the time series signal which reflect the characteristics of pulse wave in the sequence image on the base of time course.(7) The time course characteristic of infrared sequence image reflects the changed characteristics of blood vessel volume at the radial artery. Define a parameter of blood vessel elasticity. The calculation of blood vessel elasticity parameter is completed based on the characteristic of blood volume change. In this paper, contact and non-contact method can achieve human pulse wave detection and numerical analysis effectively, pulse wave characteristics are extracted in the physiological condition. We also provide a novel method of vascular elasticity detection and analysis. The research method provides effective technical means of the new detection, evaluation and calculation for clinical pulse wave diagnosis.