Research On Non-invasive Monitoring System Of Oxygen Saturation Of Blood And Its Key Technology

These years, Our country has stepped into the senile society, the pulmonary heart disease has become one of the focus of medical departments. Pulmonary heart disease often cause the lung to be oxygen-deficient, which will induce respiratory distress and in worce instances cause the patient to be dead. Because the symptom of oxygen-deficient is drastic fall of the oxygen saturation of blood,It is very important to monitor the oxygen saturation of blood in the process of prevention and cure of pulmonary heart disease.In this subject,we carried through a lot of experiment researches in order to find a solution to the continuous monitoring of oxygen saturation of blood in community.On the research of hardware system:1.In order to eliminate background light and the inherent noise of system, We Applied the modulated light;2.In order to make the baseline of signal to be steady,We developed the auto-baseline regulation circuit on the basis of MSP430 MCU; 3.We applied the adjustable integrating amplifier to make the photoelectric plethysmography signal to be amplified uniformly; On the research of software system:1.We applied self-study method in differentiation of the characteristic points of photoelectric plethysmography signal; 2.We applied the self-study threshold filtering to eliminate the motion artifact;3.We applied difference and wavelet transform in detection of the characteristic points of photoelectric plethysmography signal and transplanting the arithmetic to MSP430 MCU on the basis of instruction set and hardware multiplier;Finally,we developed an prototype of non-invasive monitoring system of oxygen saturation of blood aiming at medical monitor in community andselected 30 volunteers to carry out clinical experiment.In the process of clinical experiment,the prorotype worked stabily and met the prospective request.The technology innovation of this subject:1.On the hardware system,we adopted the PWM tenology integrating the peripheral module of MSP430 MCU to fulfil the auto-baseline regulation, which eliminate the volume of the prototype. 2.On the software system,we adopted the self-study method in differentiation of the characteristic points of photoelectric plethys-mography signal, which increased the individual adaptability effectively.