The Research Of Prototype For Physiological Parameters Monitor System

With the development of the healthy concept of human society, the variation of illness, the arrival of the old-age society and the change of medical pattern, the medical treatment pattern based on hospital will necessarily return into the pattern based on prevention and centered on community medical treatment, family and individual health care. Due to the change of the medical treatment pattern, it is a necessary trend of the miniaturization, intellectualization, individuation and network of the medical instruments. Development of the communication technology, microelectronics technology, biological material technology and the global information highway plan, highly developed digital mobile communication and international network have brought unprecedented opportunities for global information communication, resource sharing and cooperation. Mobile medical service marks the beginning of an electronic health care system from the traditional desktop platforms to wireless mobile medical telemedicine platform. As a result, users can be free from the restrictions of time and placeto monitor physiological conditions at any time without prejudice to the daily work and life, to achieve the purpose of early detection of diseases, early diagnosis and early treatment. This change is a great challenge but also a very good opportunity to the person who study on and design the medical equipments. The development of a stable and reliable monitoring system of physiological parameters of the mobile medical system is a basic platform to accelerate the change of the medical treatment pattern and the development of community health.Based on the above background, our group aims at developing a set of physiological parameters monitor system. The main system includes equipments, network communications technology and the diagnosis system. Our group takes on the research on the monitoring equipment system of physiological parameters. Unlike the traditional physical parameters diagnosis and monitoring equipment used in hospitals, mobile wireless networks can be used to monitor physiological parameters of families and individuals, mainly under the non-professional operation. Therefore, they must possess the following characteristics: the accuracy and stability of the physiological parameter measurement, simple operation, the safety and nondestructive measurement, low-cost design and so on. Our design issues base on the above characteristics to design physiological parameters measurement module, and the upper support software.The system mainly includes temperature module, blood pressure andpulse module, ECG module, the upper support monitoring system software, wireless monitoring network:1. Temperature measurement module: In the design of this module, the accuracy of measured is regarded as the main target and NTC thermal resistance is used as a temperature sensor to measure temperature. The least square method is used as the thermal resistance correction. Mercury thermometer is used for comparison calibration in medical experiments. The accuracy of temperature measurement module can reach at±0.1℃.2. Blood pressure and pulse measurement module: Special pressure sensors are used to realize AC and DC signal process on hardware circuit, cascade amplification, filtering, keep of peak value and pulse electrical level rolling-over, and so on. Software algorithm is based on the rate coefficients to measure systolic, diastolic and mean pressures. Mercury and electronic sphygmomanometer are used for comparison calibration in medical experiments. The accuracy of blood pressure measurement can reach at±5mmHg, pulse measurement at±5%.3. ECG measurement module: In the design of this module, the safety and adaptability are regarded as the important technology index. According to the ECG characteristics and noise interference, the input buffer isolation, preamplifier, the right leg drive, shield-driven, host enlargement and three filter circuit are realized in software and hardware design. The 16 order FIR filter designed in software filters out all the 50Hz interference andtheir second harmonics effectively and develops one kind of self-adaptive removed off setting algorithm to solve the problem of ECG baseline drift. The module makes use of the flat electrode to realize the standard bipolar limb leads (I ,II ,III).4. The upper support monitoring system software: Based on the research of customization and application of embedded Windows CE.net operating system, using Embedded Visual C + +, the upper support software of the monitoring system is exploited to realize multi-thread serial data communications between the module and the centre element, control of the order queue, mobile equipment storage, waveform display, the upper data transmission for communications platform and so on.Through system testing, the physiological parameters monitor system prototype is accuracy, good stability and self-adaptability, which achieves the expected objective of the basic design.