Research And Implementation Of Non-contact ECG Measurement Technology

With the improved quality of life, people pay more attention to personal health. Heart disease has been highly concerned by the public. Currently, electrocardiogram(ECG) measurement mainly use wet electrode, which is not suitable for long-term monitoring. Non-contact electrode can be a good solution to address this problem. The non-contact electrodes use the coupling capacitor between the electrode and skin to detect ECG signal. Compared with conventional electrodes, its portability and extensive applicability has greatly improved, it is very important to home medical care.For the realization of non-contact ECG measuring instrument, we mainly carried out the following work:(1) Designed the non-contact electrode based on the analysis of the non-contact ECG measurement theory. This dissertation introduced a four-layer printed circuit board as non-contact active electrode. Unlike conventional wet electrodes, the non-contact electrodes use four ECG cable to connect the electrodes and ECG conditioning circuit.(2) Designed the signal condition circuit based on the non-contact electrode with appropriate design of lead wire interface, the differential amplifier, and filtering and analog-to-digital conversion circuit. At the same time, we adjust the signal level and optimize the circuit to adapt single-supply applications for portable devices.(3) Developed the appropriate algorithms for processing the ECG data sampled in the front-end. ECG data contains many characteristics to diagnosis heart disease. According to the MIT standard ECG processing algorithm, we developed an ECG parameters extraction algorithm, which can be employed on the mobile platform.(4) Completed the development of a portable ECG monitor based on non-contact electrode, in which the improvement of the hardware design and the transplantation of the ECG data processing algorithm into the android platform were implemented.Finally, through actual test, the test results of conventional wet electrodes and the non-contact electrode were compared and analyzed, which verify the accuracy of our designed non-contact ECG acquisition system. This system can effectively extract the heart electrical parameters and monitor the human ECG data in real time mode.