Design And Implementation Of MSP430 Microcontroller-based Portable Oximeter

With the continuous progress of today's society and the continuous improvement of the people's living standards,people's awareness of medical care has become increasingly high.People need simple,easy-to-operate and portable medical equipment for health self-monitoring.Oxygen saturation is an important physiological index in daily self-management of health,which plays a very important role in clinical medical rescue work.At present,there are many portable oxyhemograph products in the medical equipment market,but they are high power consumption,high price and large volume,which are not easy to carry.High cost performance,low power consumption and portable oxyhemograph have become the research direction of the design of portable oxyhemograph.This dissertation describes the overall design and implementation of a portable oxygen meter based on MSP430 single-chip microcomputer.The main contents of the work are as follows:The preprocessor integrated chip AFE4400 of TI is adopted in the design.The chip with a simple peripheral circuit can complete pulse control,secondary gain amplification,filtering and other functions,optimize the real-time signal transmission and acquisition of oxygen system,avoid the use of discrete components circuit noise interference and poor signal processing effect of blood oxygen shortcomings.Using MSP430 as the microprocessor,a portable oximeter measurement scheme is designed.The hardware circuit is designed to complete the following modules: AFE4400 circuit module,power management module,oximeter probe module,micro-processing system,OLED display module and Bluetooth module.In the aspect of low power consumption,the power consumption of AFE4400 chip is less than 1 mA,which is lower than the traditional discrete circuit and prolongs the battery life.The software design of microprocessor includes main control program,SPI communication program between AFE4400 and MSP430,acquisition and processing of pulse and blood oxygen data,display program,etc.In the part of data processing and analysis,the calculating method of pulse and oxygen saturation is given,the moving average filter and the eight-point average moving filter are introduced,and the suitable algorithm of the system is established.HC-08 Bluetooth wireless transmission module is used to complete the design of mobile phone APP based on Android platform.It has three functions: real-time data display of pulse and blood oxygen,data background statistics and statistical results to give health advice and provides a shortcut of emergency telephone and SMS.The system uses integrated chips and low power microprocessors.After three modifications,the prototype is completed and the expected goal is achieved.The whole system has the advantages of low cost,small volume and convenient portability,and has a very good application prospect.