Design A Health Headset System To Monitor Hrart Rate And Blood Oxygen Based On BLE

As important indicators of human health parameters,real-time monitoring dynamic changes of heart rate and blood oxygen saturation can provide a scientific guarantee of the diseases prevention.In this thesis,the developed detecting system can real-time measure data of individual heart rate and blood oxygen saturation,meanwhile it can save the results to database by Internet which is convenient to query historical data.According to the design requirements of this subject,the red light with a wavelength of 660 nm and the infrared light of 905 nm are selected as the light source,and the auricle is selected as the signal acquisition site.The signal front-end processing part adopts AFE4403 chip to convert the analog signal into digital signal;The main control chip adopts NRF51822 to calculate the data,and the results are sent to the mobile terminal via Bluetooth and uploaded to the database;In this paper,the methods of preprocessing collected pulse wave and calculation methods of heart rate and oxygen saturation are discussed in detail.Firstly,multiple Weighted moving average filtering and moving difference methods are adopted to filter out the noise.Secondly,the time domain extraction feature point is used to filter the maximum value in multiple times.And the frequency domain extraction feature points are processed by sliding difference method to analytical calculation.Finally,combined algorithm of time domain and frequency domain methods is used to calculate the heart rate and blood oxygen results,and the abnormal situation is processed in the calculation process.The design of the whole intelligent monitoring system includes two parts: the slave computer design and the host computer design.The slave computer design completes the headphone hardware system design and software system design.The host computer completes the data display of mobile terminal and platform structures of service counter,database connection and Flask application development.Finally,comparing the heart rate and blood oxygen value measured by the earphone monitoring system and CONTEC pulse oximetry,the error is within the allowable range.