Research On Key Technology Of A New Wireless Detection Method For ECG Signal

In recent years, along with the rapid rhythm of people’s life, cardiovascular disease gradually becomes one of the major diseases threatening human life and health. The onset of cardiovascular disease is usually unpredictable and once the disease occurred accompanying a high risk of death. The monitoring of ECG signal, which plays a very important role in cardiovascular medical diagnosis, has attracted more and more attention. Therefore, designing a long-term, accurate and real-time portable ECG monitor and applying to the early stage of cardiovascular disease curing has a great significant in decreasing cardiac disease mortality and morbidity rates.ECG detection is one of the focuses on developing a portable ECG monitors. In the thesis, for a short detection time, the electrode stimulation on human skin and human activities are restricted by electrode wires of traditional ECG detection devices, a new ECG signal wireless detection method is presented based on non-contact ECG measurement, electronic skin, and wireless signal transmission technology. In the method, a thin skin-like membrane is developed using sensitive skin technology to combine the non-contact electrode and a sensor integrated circuit. The thin skin-like membrane naturally is pasted on human skin. Then, the ECG signal is detected by the sensor circuit is wirelessly transmitted to the readout circuit through the coupling coil which detects the receiving ECG signal by a phase detection method.In the thesis, the ECG signal wireless detection method has been studied. Firstly, the passive wireless sensor circuit uses two identical varactor diodes in series forms to realize the suppression of common mode signal and the amplification of differential mode signal. Secondly, the planar spiral inductor coil parameters of the sensor and readout circuit and the coupling performance between the sensor coil and read coil are simulated and researched by Ansoft HFSS: The planar spiral inductor model is built, and the sensor coil parameters are determined based on the optimization criteria and the influence of the parameters of the inductor coil on inductor performance by simulation; The mutual inductance model of planar spiral inductor coil is built, and the read coil parameters and the working range of the sensor coil and the read coil are determined based on the influence of the geometric parameters of read coil, the vertical distance between the coils, lateral distance and angular misalignment on coupling performance of the sensor and read coil by simulation. Finally, the readout circuit uses a phase detection method to detect ECG signal by simulation and the design of each module of the circuit is completed.