The Design Of Wrist ECG,SPO₂ And Cuffless Blood Pressure Monitoring System

In recent ten years,as the economy develops rapidly,the environment that human relies on has become more and more terrible.Chronic diseases have been found on teenagers.At the same time,people care much more about their health with the development of economy and living status.The fast-changing science makes it possible that it can be widely used in health care fields,which makes largely contribution to improve people's health standard.However,the phenomenon of aging of population highlights the lack of public medical resources.Traditional health care of hospital is far from satisfaction.As a result,those physiological parameters monitoring devices that can be suitable for community,family and individual have attracted extensive attention of researchers.As we know,ECG and blood oxygen are important physical signs of human,so we designed a system in this paper to measure ECG,blood oxygen and blood pressure.First,the thesis briefly describes the history about oxygen saturation measurement and blood pressure measurement using pulse wave conduction time.At the same time,the paper also describes their physiological significance.Then,the theory of oxygen saturation measurement and blood pressure measurement that using pulse wave conduction time are elaborated.Second,the thesis introduces the hardware and signal processing parts.The hardware part mainly includes ECG collection and blood oxygen gathering unit.The system use dry electrode on the wrist to collect ECG whiles the stander leads I are made up of the right finger and left wrist.ECG signal is amplified by pre-amplification circuit and processed by filter circuit.Finally,the AD converter of microcontroller converts analog signals to digital signals.Blood oxygen part is formed by blood oxygen probe and signal processing circuit.The flashing sequential of blood oxygen probes are controlled by MSP430F149 microcontroller.The weak current is caught by photoelectric sensor,then the current is disposed by I/N switching circuit,background light removal circuit and filtering circuit and transformed by AD converter.Data gathered by microcontroller will be imported to upper computer,which is filtered and feature extracted by MATLAB.Finally,the empirical coefficient of blood oxygen measurement and blood pressure measurement systems are confirmed by experiments.With the accomplishment of system calibration,using our own system and commercial products take actual measurement.Eventually the comparison and error analysis of measurement result verify the system's accuracy and reliability.