Designed A New Type Of Pulse Wave Detection System Based On Usb2.0 Interface

Pulse wave of human body contains a number of important physiological and pathological information, in particular with the human cardiovascular system-related information, so it is an important physiological indicator of biomedical detection. The pulse wave becomes a focus of medical research not only in China but also in other countries. Therefore, the measurement of pulse wave is a very important research direction in clinical medicine. The high-quality signal of pulse wave and effective signal processing methods play a decisive role in the analysis and calculation of the parameters disease-related.Based on the study of pulse wave with its generation and dissemination, a novel pulse wave detection system using USB2.0 interface was developed, and the system was tested. Major work is described as follows:(1) According to the structure of radial artery in the body and theories of the Pulse Diagnosis of Chinese medicine, a new type of pulse wave sensor is designed. A transducer is designed by PVDF (polyvinylidene fluoride), a new piezoelectric material. With a front charge amplifier, the sensor can be used to detect the pulse wave accurately.(2) The circuit of signal conditioning for pulse wave is designed and developed including the multi-level amplifiers and the filters. In addition, the chip of AT89S52 working as a microcontroller is choosed for data acquisition system and the CH375 , a chip which supportting the USB2.0 interface standard is choosed. At last, the firmware of the MCU (Micro Controller Unit) is completed for data acquisition and data communication with the computer.(3) With Visual C++6.0 software as a development platform, the pulse wave detection and analysis system is designed and developed, which can be used to receive the pulse wave data for analysing and describing waveform, to preserve data, and to register the patients information for saving and querying.(4) In the MCU and computer system, digital filtering algorithms are used to filter the pulse wave signal. Using the MATLAB software,FIR digital filter is designed to reduce the noise interference and to improve the signal to noise ratio. A lot of small size, light weight and portability package of chips are used in the detection system. The pulse wave measurement system can be used to provide a reference for doctors because of its real-time measurement and its dynamic analysis.