Design And Implementation Of Seismocardiogram Insusceptibility Detection And Real-time Display System

As the most important human circulatory system organs, the importance of heart is self-evident. Currently, the most common clinical test method is ECG testing, but the use of electrodes is not suit the long-term and real-time detection.The paper designs a non-feeling detection system based on BCG signal, measures the mechanical movement of the heart with the pressure sensors which are closely connected with the objects, and displays the BCG signal and related parameters on home or portable embedded display device.The system consists of signal acquisition module, signal transmission module and the graphics display module. Among them, the signal acquisition module includes the sensor circuit, amplification circuits and filter circuits. The sensor circuit captures the BCG signal through the four pressure sensors composed of full-bridge circuit and amplify the signal through the amplifier. In order to filter out high frequency components and frequency interference, the module uses a low-pass filter circuit and the notch filter circuits. Signal transmission module sends the analog signal from the signal acquisition module’s output through the serial. Here the master chip is Microchip’s PIC18F2420and complete the signal conversion and transmission using its built-in multi-channel10-bit AD and serial. Graphics display module displays the signal processed by hardware through embedded graphics library and adds the software filtering effect. This module uses the graphics library GTK+which has been widely used in embedded device as the depended library. After the needs analysis, system design, detailed design, coding, testing and so on, the paper completes the design and display of the GUI.Through experiments and testing, the system achieves BCG acquisition in the embedded devices, weak signal amplification, hardware filtering, analog-digital conversion, serial transmission, software filtering, real-time display and friendly interface features, reaches the desired functionality. As the GUI development based on GTK+can easily achieve cross-platform portability, supports more embedded devices, so this paper provides design ideas for home or portable embedded monitoring devices’ research and development and confirms its feasibility.