Study On Detection And Real-Time Processing Equipment For Ballistocardiogram

As is known to all,heart is the motivation of all human activities and the health of the heart plays an important role in normal activities of the human body.In recent years,the heart disease has become a threat to the health of human life.ECG is often used in clinical applications to monitor the cardiac function.However,this method needs to the direct contact between electrodes and human skin,which is not suitable for long time used in the monitoring of cardiac function.So it is necessary to design a real-time monitoring device for human cardiac function in the daily life to make the real-time,accurate assessment and make the users know the condition of his cardiac function in a timely manner which has high important research values and broad application prospects.BCG signal is caused by the pump activity of the heart,which causes the body weakly mechanical synchronous vibration,and it contains a lot of important information and details related to heart activity,what is more,BCG signal can realize non-contact and no feeling,which is very suitable for long time monitoring of the daily life for the activity of the heart.This paper designed a monitoring and analysis system for BCG signal based on architecture Cortex-M3.It mainly includes two parts:heart monitoring device and cardiac vibration signal monitoring and analysis platform on PC.In this paper,the mainly work includes:firstly,the hardware circuits of the heart vibration monitoring device includes analog circuits and digital circuits,and of them analog circuits includes preamplifier circuit,filter circuit and the main amplification circuit,while digital circuits selected STM32F101C6T6 as the main control chip,of which minimum system circuits and the Bluetooth communication circuits and so on were designed and implemented.In the process of ADC signal conversion,by using the on-chip and low cost 12 bits ADC the analog circuit was turned to the digital circuit.Secondly,based on the STM32 main controller,a heart vibration signal preprocessing algorithm was designed,including smoothing and 50 Hz frequency filtering algorithm.Then put the cardiac function data to PC software algorithm for further processing via Bluetooth module.Finally,under the environment of Microsoft Visual Studio 2010,the BCG signal monitoring and analysis platform was designed.At the same time,the filtering algorithm of EEMD(ensemble empirical mode decomposition,EEMD)was used in BCG digital signal processing for the first time.What is more,the experimental test results show that the algorithm in the BCG signal processing is not only stable and reliable,but also with a good performance.