The Research And Design Of Continuous Blood Pressure Measurement Bracelet Based On PPG Signal

With wearable devices becoming popular,the implementation of blood pressure measurement on wearable devices has become a hot research topic in recent years.And blood pressure devices show a tendency towards more exquisite outline,more intelligent operation and continuous measurement.A continuous blood pressure bracelet based on Photoplethysmogram(PPG)signal is researched and designed in this thesis.PPG signal is collected on the skin and blood pressure is estimated by PPG signal detection algorithm.Due to great application prospect of the blood pressure function in wearable devices,an open access configuration of Bluetooth Low Energy(BLE)has been researched and an open connection between blood pressure bracelet and smart phone has be implemented.An application(App)on Android platform working with blood pressure bracelet is developed.The App can connect with blood pressure bracelet and implement open data interaction.Specific work contents are as follows:1.On the basis of deeply study in blood pressure measurement algorithm based on PPG signal,a continuous blood pressure measurement algorithm is proposed.Test results prove that the algorithm is in preferable consistency with the electronic sphygmomanometer,and the error of systolic blood pressure and diastolic blood pressure is 0.79?4.79 mmHg and 0.73?3.47 mmHg respectively,which satisfied the requirement of Association for the Advancement of Medical Instrumentation that standard deviation is not greater than 8 mmHg.2.Selecting pulse sensor MAX30102 as the solution of PPG signal acquisition module and designing the application interface circuit after multiple technical surveying.Selecting PSoC 4 BLE based on Programmable System on Chip(PSoC)as the solution of micrococntroller and Bluetooth.Implementing the core function of blood pressure bracelet by the programming of hardware drivers,PPG data reading and processing,and Bluetooth function.3.On the basis of deeply study in principle and composition of BLE technology,data frame and data structure was configured in Generic Access Profile and Generic Attribute Profile in the BLE protocol stack.Given the open configuration of BLE and an open connection between blood pressure bracelet and smart phone has be implemented.4.Blood pressure App is programmed under the Android mobile operating system to implement the devices scanning,connection,service discovery,real-time data reporting and displaying.The App provides the platform of device access and data exchange for blood pressure bracelet to enhance the user experience.