DSP-based multi-function EASI-second lead Holter system (1).

<P> Cardiovascular medicine today the highest morbidity and mortality one of the diseases, according to statistics, more than 1 700 people a year die of heart disease. .In modern medicine, the ECG ECG (Electrocardiograph) ECG to diagnose an important basis for the disease. .Conventional analysis of electrocardiograms, only a short time the patient ECG information on the static and dynamic ECG Holter is a long time to reflect information in the clinical diagnosis has an important role. .1961 Norman J. Holter Holter recorder was first put into clinical use, so often the record of heart disease known as Holter equipment Holter. .</ P> <P> traditional microcontroller based ECG Holter to achieve the display, transmission and simple alarm contracting disease, but the operation speed is limited by the microcontroller, be difficult to detect accurate but expensive method to achieve relatively high .line analysis of ECG data. .This article is TMS320VC5509A TI's core processing system, with a high common mode rejection ratio of the EASI-second lead ECG acquisition programs to achieve a real-time detection, wireless transmission and 24-hour ECG Holter recording function versatility .system. .The real-time monitoring system can Dr. Fang Bian patient ECG information to respond to sudden illness, it will be a new generation of "digital medical community / hospital" important in telemedicine development. .</ P> <P> 1 EASI-second lead system </ P> <P> EASI lead system is the second commonly used in clinical diagnostic ECG system. .EASI ECG is a derivative of the twelve-lead ECG, the biggest advantage is that you can produce 5 ECG electrode bipolar lead three-way data, and derived very similar to the standard twelve lead ECG data. .The lead system consists of five electrodes E (5th intercostal sternum lower level), A (Zuoye middle level position E), I (the right middle axillary line level position E), S (sternal manubrium) and RL (right- .leg drive electrode, the general placement Youfu) composition [1]. .Electrodes affixed to put the location shown in Figure 1. .</ P> <P align=center> </ P> <P> EASI-second lead system can mathematical formula: Ld = a (AI) + b (ES) + c (AS), obtained by second transformation .lead ECG information. .Where AI, ES, AS bipolar leads for the three-way data can reflect the cardiac vector, respectively, in the coronal, sagittal and frontal plane ECG changes, a, b, c is obtained through large sample studies .Exact correlation coefficient [2]. .After a large number of clinical studies have proven that through the EASI-second lead ECG system, the amount of information obtained is very close to the standard twelve-lead ECG [3]. .</ P> <P> 2 Hardware Design </ P> <P> 2.1 system solutions </ P> <P> system block diagram of the design shown in Figure 2. .</ P> <P align=center> </ P> <P> Holter system is composed of the EASI-second lead ECG acquisition circuit, TMS320VC5509A, external mass storage (such as the SD memory card), liquid crystal display module, Zigbee .modules and power management components. .Electrode from the body surface ECG signal to obtain biological, low-pass filtered access to the two band-pass amplifier amplification and A / D conversion, A / D converted data can be stored directly in addition to offline analysis in external MicroSD card ., also run by the second derivative by the TMS320VC5509A wavelet transform algorithm for real-time detection of the ECG or by ECG Zigbee transmission will be transmitted to a remote monitoring center for real-time monitoring. .</ P> <P>.