Remote ECG Signal Data Acquisition And Preprocessing

With the advent of the intelligent age,data sharing,Internet of Things technology has covered all aspects of our lives,telemedicine has also begun to rise,especially for cardiovascular diseases,which have sudden characteristics,and the development of portable ECG monitoring equipment is carried out in a timely manner.Monitoring has become an urgent need for people.This paper studies and improves the signal preprocessing method and designs a remote ECG signal data acquisition system,which provides a basis for remote heart disease diagnosis and is of great significance to the realization of smart medical care.The paper first proposed a wavelet threshold denoising algorithm(Remove frequency domain aliasing,RFDA)to eliminate frequency aliasing.This method uses Stein unbiased risk estimation to adaptively estimate the threshold and determine the risk value corresponding to the high-frequency detail component;Aiming at the problem of frequency aliasing caused by the orthogonal mirror filter does not have ideal cut-off frequency characteristics in the wavelet MALLAT decomposition algorithm,the paper uses Fourier transform and inverse Fourier transform to remove high-frequency detail components due to frequency mixing.The overlap produces low-frequency components.Because the interference frequency is reduced,the determined threshold is more suitable for the actual situation.Finally,the simulation verifies the effectiveness of the method.In practical application,on the basis of detailed analysis of the domestic and international ECG signal acquisition methods and the physiological characteristics of the ECG signal,the overall design scheme and structural framework of the ECG acquisition system are given.The system has a four-layer structure,namely the perception layer,application layer,network layer and platform layer;through the perception layer,variable-lead ECG data collection is realized,and the application layer is used for uploading,downloading,and playing user data and ECG data As well as preprocessing,the network layer realizes the data communication of the Internet,and the platform layer is the server of the ECG data,which completes the storage of the ECG signal and provides the basis for the expert consultation.In the perception layer,a real-time acquisition system for variable-lead ECG signals based on ADS1293 is designed.The system is divided into an upper computer part and a lower computer part.The lower computer part uses STM32 as the core to control the signal acquisition of different leads.The peripheral circuit includes three biochips ADS1293,communication circuit design,power circuit design,buttons,etc.STM32 and ADS1293 use the SPI protocol to communicate;under the μC/OS-II embedded operating system,the initialization of various functions including ADS1293 is completed,and the ECG data converted and processed by three ADS1293 s are sequentially read through the SPI protocol.The ECG data to be processed is transformed into usable ECG data,and the ECG data is transmitted to other devices for display and storage.The upper computer part uses Yangchuang Technology’s ES80N-L industrial panel computer to display the ECG data transmitted from the lower computer.The interface is designed under the PC-side LINUX environment QT development framework,cross-compiled into an executable file and then transplanted to the tablet computer.In the application layer,an ECG data client for human-computer interaction is developed to provide interactive services such as registration,login,upload and download of ECG data,playback,and denoising.At the network layer,the reliability of the data needs to be guaranteed when the client and server networks transmit ECG files.In the platform layer,a server for storing personal information,ECG data and preprocessing of ECG data is developed.Two databases are selected and used in the server: My SQL database and Redis database,among which My SQL database is used for storage Personal information and ECG data,and Redis database as a supplement to My SQL database solves the problems of repeated logins and long network connections.In view of the high concurrency problem caused by a large number of client network connections,the server uses a combination of I/O multiplexing epoll technology and thread pool technology to solve it.