Research On A Multi-physiological Signal Monitoring System Using The Ballistocardiogram Technology

Heart physiological signals such as heart rate and blood pressure are important for the diagnosis of some diseases.At present,the most common cardiac tests include ECG,UCG and blood pressure measurement.Ballistocardiogram signal is a mechanical vibration signal resulting from heart cycle activity and can be transported to all parts of the body by blood flow.At present,the statistical properties of ballistocardiogram signal have been used to diagnose coronary heart disease and ventricular premature beats.In this thesis,we proposed a multi-physiological signal monitoring system using ballistocardiogram technology.The designed system realized continuous,real-time and non-direct contact monitoring of heart rate,blood pressure and other physiological signals.Among various blood pressure measurement methods,sound auscultation method and wave method are most commonly used in which a arm cuff is indispensable and people must keep still during the measurement.Especially,sound auscultation method needs to be operated by medical staff and is not suitable for real-time daily blood pressure monitoring.None of the above methods can achieve non-direct contact and continuous measurement,and only continuous,real-time heart rate and blood pressure signals can provide accurate data for the diagnosis and treatment of related diseases.Therefore,designing a portable,reliable and non-direct contact multi-physiological signal monitoring system has great research significance.In the thesis,we first introduced the principle and characteristics of the ballistocardiogram signal,then designed the corresponding hardware circuits to get the signal.A high-sensitive piezoelectric film sensor was embedded in a bed or chair and the ballistocardiogram signal was converted to electrical signal while a tester sat or lay on it.The real-time display and heart rate extraction of ballistocardiogram signal were realized by using S3C2440 core processor and Linux operating system.Finally we developed a continuous blood pressure measurement program,in which the dual-channel signal transmission time measurement method was used to realize a non-contact continuous blood pressure measurement through a fitting function..The designed monitoring system can be applied for non-direct contact continuous blood pressure measurement,heart rate extraction and the collection of ballistocardiogram signal.The non-direct contact continuous blood pressure measurement using the ballistocardiogram signal has not been reported to the best of our knowledge.This monitoring system is particularly suitable for continuous blood pressure and heart rate monitoring of long-term bedridden persons as well as people in wheelchairs.It can also be used for the routing detection of physiological signals for common people and has a strong practical value and a wide range of application prospects.