The Implementation And Realization Of The Pulse Wave Signal Generator Base On FPGA

In recent years, cardiovascular diseases have endangered human health seriously. It is helpful to identify patients with cardiovascular diseases if the physiological and pathological conditions of the cardiovascular system are detected beforehand. The disease incidence will be reduced greatly if effective preventions and appropriate measures are taken. Pulse wave is the basic human physiological signal which contains physiology and pathology information of the cardiovascular system. Health condition will be acquired in time by detecting the pulse wave. In order to evaluate the functions and parameters of the pulse wave equipments, it is important to obtain accurate pulse wave corresponding to different kinds of physiological conditions. However, at the developing stage of the equipment for acquiring pulse wave, it is usually not convenient to get specific signal to debug and evaluate the developing system, so a signal generator which can produce accurate pulse wave is need to this problem in clinical application.A pulse wave generator is designed in this thesis using two methods. Gaussian function is used because its shape is similar with pulse wave. The pulse waves are cut into several parts according to the feature points. After selecting appropriate parameters, each part is fitted and then they are synthesized to a whole period pulse wave. Blood vessels elasticity chamber model is also used in this paper to generate pulse waves. The third-order differential equation is established by the equivalent circuit. The numerical solution of the differential equations, that is, the output pulse wave, can be obtained using the fourth-order Runge-Kutta method. Meanwhile, some functional models are also added:adding three kinds of noises (50 Hz frequency noise, random noise, and Gaussian White Noise), setting SNR, and adding baseline drift. The period of the output pulse wave can also be changed.Field programmable gate array is used in this thesis as hardware development platform. Power buck module, ADS module, LCD interface module and other peripheral circuit are designed. The function models such as pulse wave generation algorithm, acquisition of touch screen coordinate and adding noises are completed under the development flow of SOPC. When users input in the key parameters through LCD and touch screen, the corresponding pulse wave will be displayed on LCD and, also, pulse waveform can be accessed from analog output channel.The pulse waves designed in this thesis overcome the shortcomings such as requiring large capacity RAM memory, limitation of the output wave types and low degree of the simulation. It plays a significant role and has a god practical value not only in practical teach but also the application of the performance verification for diagnostic instruments in clinic.