Design And Implementation Of ECG System Based On XSCALE PXA270

The electrocardiogram represents reaction of the heart in the process of electrical activity. It has important reference value for the basic function of the heart and its pathological study.The thesis is to achieve an electrocardiogram instrument with many characteristic, such as high-performance, well portable and handy extensibility. The instrument also provides a user-friendly interface, so it is easy to be operated.The paper introduces the design and implementation of ECG based on Intel XScale PXA270 processor and Windows CE 5.0 OS. We utilize PXA270 in this system, which is an embedded CPU belonged to the series of XScale and support for special wireless SpeedStep dynamic power management technology of Intel. The technology make PXA270 maximize to reduce power consumption of the whole system with high performance of CPU, and extends the life of the portable products. In addition, the device can support touch-screen operation, which is a unique of this system. The system uses an external chip of UCB1400 to expand the functions of a touch screen, which makes the system not only user-friendly, but also be operated conveniencely.This article focuses on the design and implementation of handling and display modules.The thesis is separated into four parts to describe the feature of our ECG system.Firstly, beginning with the feature of the embedded system, the thesis gives a detailed analysis to today's mainstream embedded ARM processors and then compares several popular embedded operating systems.Secondly, through the analysis of our design goals and performance requirements of the system hardware platform, the system determines the CPU selection and framework structure of hardware. The system hardware structure uses the realization of a separate framework, which is consist of the core CPU module and the backplanes which is used to realize a variety of peripherals.Then the paper gives the feature of PXA27x microprocessor, and takes microprocessor PXA270 as the core unit to discuss the design and plate-making of external circuit.Thirdly, the thesis discusses the architecture of Windows CE 5.0 and gives its features and development methods of software. The paper introduces the operating system development platform of Platform Builder 5.0. Then the paper introduces the general development process of operating system and transplants the Windows CE 5.0 OS for the ECG system.Finally, the thesis introduces the software development of ECG Design of the whole system utilizes a multi-thread mechanism. The paper mainly discusses around the realization process of multithreading and gives detailed analysis of thread synchronization. Then the article introduces the communication process between the acquisition module and processing and display module. In the end, the paper introduces the drawing method of ECG waveform and grid.At the end of the paper, we show the test result of the ECG system.