The Design And Realization Of A Multi-function 18-lead ECG Simulator

ECG (electrocardiogram) simulator is an important testing equipment to detect ECG testing equipment for functionality and accuracy of ECG parameters. It can determine whether ECG testing equipment reaches the design requirements and the agreement standards. ECG testing equipment contains ECG machines and ECG monitors. According to the relevant design standards and market demands of ECG testing equipment, this paper designed an 18-lead ECG simulator which can output ECG signal, respiratory signal, polarization voltage and PACE signal in the same time.Firstly, this paper describes the ECG detection summarily and explains the role of ECG testing equipment. After the background and status of ECG testing is introduced, analysis of the important role the ECG simulator playing in testing ECG detection equipment is presented. The current development of ECG simulation is given. Then the article explains the basic theory of ECG, including the definition and characteristics of ECG and the definition and formula of ECG lead. In order to meet the design requirements of the simulator, the paper makes a detailed classification for the requirements and proposes feasible design options. ECG testing equipment is directly applied to the human body, so the design using split design. The ground accessed to electricity is separated from the ground directly contacted with the body. The two ground planes are called field and floating respectively. In order to remain divided into two parts in the test process, the simulator also uses split design. The hardware circuit is divided into four modules, including the power supply circuit design, field test circuit design and floating side of the circuit design. Because the ECG, respiration signal, polarization voltage and PACE signal is the key of the simulator design, these four generating circuit are divided into a single module to make detailed analysis. Software design of the system introduces the main design of the system and four major program modules including D/A conversion process, ECG simulation program, the respiratory signal simulation program and PACE signal simulation program, and a brief introduction of the data transmission software module is made. Finally, conclusions and future improvements are carried out.In the current domestic market, most of the ECG simulator only output 12 leads and not able to simultaneously output other human physiological signals. The multifunction ECG simulator designed in this paper totally has 16 output channels and can output 18-lead ECG. The superimposed signals in ECG analog, including respiratory signal, polarization voltage and PACE signals, make the ECG detecting environment closer to the human body. In addition, the STM32F103 used as core MCU provides a powerful computing and control capacity for the simulator. This ECG simulator is sufficient to meet the requirements of current ECG testing equipment and the design level is at the forefront of similar products.