Research On ECG Signal Acquisition System Design And Encryption Algorithm Based On WBAN Chip

In recent years,with the solution of the digital problem of medical information and the development of body area network communication technology,the demand for remote diagnosis,smart medical treatment,mobile clinical,community smart pension and so on appears.The key to meet these demands is how to carry out reliable encrypted data transmission.The communication of body area network is different from the existing wireless communication protocols such as Bluetooth and Zig Bee in wireless sensor network.Although this concept was put forward very early,it did not get rapid development until IEEE 802.15.6 protocol came out.According to the characteristics of biomedical data,the protocol increases the function of communication network optimization,and reduces the crosstalk between various communication protocols when the biological signal is transmitted on the human body surface,so it is a short-distance communication protocol suitable for the body local area network.This thesis designs a wearable wireless ECG signal acquisition system.The system can switch the working and standby state of the system in real time through the connection of PMOS switch circuit and ASIC baseband chip of WBAN,thus reducing the power consumption of the whole system.The system uses the baseband chip of the body area network to make the signal transmission of the whole communication network meet the IEEE 802.15.6 protocol,and the data sending and receiving task can be completed by the RF chip at the back end.During ECG signal acquisition,noise such as baseline drift and power frequency interference will seriously affect the recognition and location of subsequent QRS wave groups.In order to improve the stability of the output ECG signal of the whole system,morphological filtering algorithm and notch filter are added into the terminal design of the system.Finally,according to the structural characteristics of the physical layer of the WBAN,an encryption method based on the protocol data of the physical layer to extract random numbers and eigenvalues of ECG signals to generate XOR keys is studied,and a secure transmission scheme of WBAN signals is designed according to this method.The main research contents include ECG filtering,QRS recognition and location,and encryption key generation and dynamic update with ECG eigenvalue.This scheme starts from the inherent physical layer specification characteristics of IEEE 802.15.6 protocol,combines the characteristic values of the body data,jointly constructs the signal network security transmission mechanism,and transfers the algorithm of filtering and positioning which have great computing power in the system to the upper computer to process,which is beneficial to improve the battery life working ability of the acquisition device and realize the low-power design.