Study On Electronic Analytical Apparatus Of Heart Sound Based On Capacitive Sensor

Heart sounds auscultation is an important way of examination of heart diseases. But auscultation is often restricted by the subjective judge, resulting in blocking the development of heart sounds diagnosis at a certain extent. So, improving the diagnosis level, is the urgent need to resolve the important medical issues.Heart sounds, result mainly from the interaction of three events: the contraction and relaxation of the atria and ventricles, blood flow, and valve movements. Heart sounds signals identification and classification are of great significance for the diagnosis of cardiovascular diseases, the effects of diagnosis and treatment of heart diseases depend on them. An Electronic Analytical Apparatus of Heart Sounds, which based on pure capacitive sensor supplied phantom power, was presented in this paper. The apparatus is not only able to capture and display the heart sounds signals and electrocardiogram synchronously but also replay the chart and the sound of heart sounds signals. Moreover, it cann't able to manage the personal information of the sufferers but also save, review and analyse the previous heart sounds, monitor the critical patients timely and used as the clinical teaching for schools. The most important issue, a kind of special sensor which based on phantom power was made, the sensor is small and used easily without any trauma to people, it is a kind of special sensor only used for capturing heart sounds.The main works in this paper are listed as follows:①Study on the basic knowledge of heart sounds, including the principle of production, transmission principle, the heart sounds signals characteristics and the traditional phonocardiogram.②Combine with the unique human voices - heart sounds, study on the acoustic and transmitted characteristics.③Design the hardware circuit of the Apparatus of the analytical Apparatus of Heart Sounds. Including the analog, digital circuits and power supply circuit. In order to improve the anti-jamming capability and increase the clinical valuable heart sounds signals.④Study on electric-audio sensor, including electret, dynamic and pure capacitive microphone. Have done clinical trials, summed up the merits of their performances in the clinical applications. ⑤A heart sound sensor, the pure capacitive microphone which based on phantom power supplied and have high sensitivity, wide frequency response and low cost, was made in this paper.⑥Debug the whole system, including the hardware and the software, it can able to capture and display the heart sounds signals and electrocardiogram synchronously, able to replay the chart and the sound of heart sounds signals, able to save, review and analyse the previous heart sounds.⑦Clinical data extraction, classification and analysis.