Research On Dynamic Pulse Rate Data Acquisition And Pulse Signal Processing System

Cardiovascular diseases are the major factor that harms the human health.As the rapid progress in people's living condition and the greying of Chinese population,the morbidity and mortality of cardiovascular diseases increase gradually,people need a non-invasive method to examine their health status.The pulse signal is a kind of non-linear,non-stationary as well as weak signal,which contains abundant human physiological and pathological information,plays a significant role in making early diagnosis and treatments for cardiovascular diseases.The pulse rate is detected in static states now.If can record in long-term continuously,it will reflects changes in blood vessel systems of human body.The work in this paper is mainly about the design and realization of dynamic pulse rate data and pulse signal processing.To begin with,the acquisition system of pulse rate data and pulse signal is designed by MCU of AVR ATmega16.Both the cost and the quality are also considered. The hardware device can acquire and store data,and communicate with PC using USB interface.The virtual pulse signal processing system is designed in PC based on vitual instrument software LabVIEW,includes the management of patient information,the acquisition of data,the process of signal,the communication of data,which adopts the approach of Multi-panel and the idea of modular design.Secondly,the SNR of pulse signal is lower than others.In order to avoid the wrong identification from the characteristics of pulse signal,to remove the EMG interference, powerline interference and baseline-drift existing in the course of collecting pulse signal data were proved importantly.Based on Donoho's method of wavelet transformation (WT),an improved wavelet denoising method with adaptive thresholding is given,which has both advantages of hard-thresholding and soft-thresholding.The simulation experiment indicates that the proposed method is better than traditional wavelet thresholding denoising methods.Finally,the pulse signals of students and patients of crdiovascular diseases are analyzed.The energy of every scale is extracted based on WT.Aiming at the characteristics of pulse signal frequency band,the algorithm of feature extraction is improved.The experiment datum indicate that the range of features can distinguish pulse signals of patients from limited samples,which presents a good recognition accuracy. Because wavelet packet transform(WPT) can provide an arbitrary time-frequency decomposition for the signals,which is a more refined method of signal processing. Further,application in feature extracting of pulse signal based on WPT is put forward,it can identify the signal of patient which is recognised incorrectly by WT.