Design Of Wireless Acquisition System Of Emg And Inertial Information

With the development and application of electromyography(EMG) signal in Rehabilitation engineering and Sports Science fields, the real-time recording of EMG Data during motion is a research focus that tends to portability and diversification. the synchronous acquisition of EMG data and inertial information can be useful to applied and practical values in functional evaluation and sports monitoring. In this paper, a wireless and portable system for synchronously acquiring EMG data and inertial information was established and designed. The system can realize the real-time signal process in hardware circuit, acquire external sensor information by extended interfaces and communicate with multi-platform based on wireless network and so on. The specific work of this paper is as follows:Firstly, the generated mechanism, general basic characteristics and detected principle detection mechanism of EMG signal acquisition were described. The widely applied acquisition equipments for EMG data were introduced and compared from both points of benefits and limitations comparative advantages and limitations of the current mainstream EMG acquisition equipment. The integrated scheme was proposed to synchronously record the EMG data and inertial information. In this scheme, the design principle of EMG acquisition module, inertial sensor module and wireless transmission module and the procedure of the system were elaborated in this section.Secondly, the hardware unit of the wireless system for EMG and inertial information acquisition was designed. Considering the complex interference sources during motion and the requirement for preprocessing, the conditioning Circuit for the EMG data acquisition was designed from four parts including preamplifier circuit, filter circuit, voltage superimposition circuit and power circuit; The detection circuit for nine-axis inertial information was established from both drive circuit and communication protocol of the inertial chip. After that, the conditioning Circuit and detection circuit were integrated into the hardware.Thirdly, the software unit of the system was also designed. The main functions of hardware cell were realized based on the task scheduling of hardware processor, AD-DMA acquisition and serial communication protocol; The wireless network was designed from the aspects of Wi Fi network topology, data transmission protocol and network parameter setting; concurrently, Multi-platform interface was designed on the basis of the data processing in PC and data interface on Android platform.Lastly, the wireless EMG information acquisition system was used into the upper limb flexion or extension experiment, during which two-channel EMG data and nine-axis inertial information were recorded. The features of the intermuscular coherence, motion direction and motion range were extracted to analyze the functional coupling between in channels and the motion coordination. These analysis can be useful to make evaluation on motion ability of upper limb.