Cardiovascular Hemodynamics Monitor System Based On Impedance Inspection

The noninvasive cardiovascular hemodynamics monitor system is still in the period of discovery. The popular monitor system nowadays is based on impedance inspection. These systems that put forward and developed by Nyboer J. and Kubicek G. M. are based on Ohm Law and Three Component Cell Model. The computing formula of the system I designed is Kubicek Formula. In my subject, I designed a data sampling and cardiovascular hemodynamics analysis system based on impedance inspection. I validate it by some experiments. In this article, we first jump in the research results in recent years of the related subjects and then describe the mathematics model, to find out the key of my job: analyzing the real-time cardiovascular hemodynamics parameter. In this part, the emphasis is physiology and physics elements. I introduce the system's structure after that. The hardware of this system is XL-200 two leads impedance cardiograph instrument. One constant current supply is used in this instrument in mode of time-sharing. Two leads are switched by analog switch fleetly. The advantage of this method is to avoid the interference of signals. I use Visual C++.NET designed software system. I analyze the requirement of my subject, contrast diversified arithmetic of ECG analysis, and then select one of them that are suitable for my subject. On the basis of ECG analysis arithmetic I developed an impedance signal analysis method. The software system is developed by Visual C++.NET. The figure output APIs use the Microsoft GDI+ APIs and the serial communication part use the Microsoft MSComm Control. The system's stability and fluency are assured by these two techniques. The program is structured by obeying the waterfall model. The program is modularized for future update and maintenance. I also use multi-thread technique to deal with the I/O synchronization problem. The highlight of this system is that it implements the function of real-time analysis,long-term monitor and data storage of cardiovascular hemodynamics. And it can reproduce the analysis process. I have designed the interface for database of hospital cases. There is no such a mature analysis arithmetic in impedance inspection field. The arithmetic I used is an elementary explore in impedance inspection apply. And I still not found the similar arithmetic in others articles. The experiments on different ages validate this arithmetic's reliability.