基于USB2.0接口的新型脉搏波检测系统设计

【作者】 于贺辉；

【导师】 庞小峰；

【作者基本信息】 电子科技大学 ， 生物物理学， 2008， 硕士

【摘要】 人体脉搏波包含了许多重要的生理和病理信息,尤其是与人体心血管系统相关的信息,所以它是生物医学检测中的一个重要的生理指标。中外医学对脉搏的研究都很重视。因此,对脉搏波的准确、快速而方便地检测,成为临床医学中的一个非常重要的研究方向。而高质量脉搏信号的获取和有效的脉搏信号处理方法对与疾病相关的参数的计算分析起着决定性的作用。本文在研究脉搏波的产生和传播的机理的基础上,开发了一套基于USB2.0通信接口的新型脉搏波检测系统,并对系统进行了测试。主要工作内容如下:(1)根据人体桡动脉的结构和中医脉诊理论,设计了一套新型三触点脉搏波传感器。该传感器采用压电原理,选用新型压电薄膜材料PVDF(聚偏二氟乙烯)设计了换能器,并结合了前端电荷放大器,用于对脉搏波的准确检测。(2)设计并开发了用于脉搏波信号调理的多级放大和滤波电路,以及以AT89S52单片机为核心的数据采集电路和以支持USB2.0接口标准的CH375芯片为核心的USB接口电路,并完成了单片机固件程序的编写,用于前端数据采集和后端的数据通信。(3)以Visual C++6.0软件为平台,设计并开发了脉搏波检测与分析系统应用软件,用于对脉搏波数据的读取、分析、波形描述和保存,以及病员信息登记、保存、查询。(4)分别在单片机和计算机里运用数字滤波算法对脉搏波信号进行滤波处理。用MATLAB软件设计了FIR数字滤波器,对读取的数据进行滤波处理,有效降低了噪声干扰,提高了信噪比。本检测系统外围电路采用大量贴片封装的芯片,体积小、重量轻、便于携带。通过USB口进行供电,不需要外接电源,并可以进行脉搏波的动态实时测量,是一种极具发展潜力的新型脉搏测量系统。更多还原

【Abstract】 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.更多还原