Research And Development Of TMS Motion Evoked Potential Detection Technology Based On Bluetooth Transmission

TMS MEP is a non-invasive neurophysiological technique for the diagnosis and monitoring of neurological activity and function.It can be used to study the integrity of the corticospinal tract and the excitability of motor cortical and anterior horn motor neurons,and has important clinical implications for research in sports and rehabilitation medicine.This study presents the design of a Bluetooth-based MEP detection system that capitalizes on the characteristics of TMS MEP.The system comprises two main components: the TMS MEP conditioning module and the real-time acquisition module.The TMS MEP conditioning module consists of a pre-amplification circuit,a leg-driving circuit,a filtering circuit,a secondstage amplification circuit,a level-lifting circuit,and a power supply circuit.This module exhibits favorable attributes such as linear gain,high common-mode rejection ratio,high input impedance,and low noise.The TMS MEP conditioning module captures the MEP from the target area,amplifies,filters,and levels TMS MEP up to produce analog signals compliant with the requirements of the internal analog-to-digital converter of the STM32 microcontroller.The real-time acquisition module of the TMS MEP system employs the STM32 microcontroller as both a controller and an analog-to-digital converter to convert the analog TMS MEP into digital signals.These signals are then transmitted to a host computer via Bluetooth for display on a user interface.The interface provides basic functionalities such as real-time waveform display,data visualization,and waveform storage.It is characterized by its user-friendly operation and simple yet concise design.Finally,the performance of the designed TMS MEP detection system was tested.The performance of the TMS MEP conditioning module was evaluated in terms of gain linearity,bandwidth,common-mode rejection ratio,differential input impedance,and input noise.Additionally,the data transmission rate,sampling rate,and measurement accuracy of the system were examined.The results demonstrate that the designed circuit exhibits excellent gain linearity,with a bandwidth ranging from 11 Hz to 1300 Hz.The common-mode rejection ratio was measured to be 111.47 d B,the input impedance was found to be 7.664 MΩ,and the input noise was recorded at 0.78 μV.These results indicate that the designed circuit possesses good gain linearity,enabling the detection of subtle TMS MEP.The sampling rate,data transmission rate,and measurement accuracy of the TMS MEP detection system were also assessed.The sampling rate of the designed system was determined to be 9965(±235)samples per second,the data transmission rate exceeded 60 k bytes/s,and the measurement accuracy of the system ranged from-3.9% to +2.8%.The test environment was set up to perform TMS MEP detection.Single-pulse transcranial magnetic stimulation was applied to the primary motor cortex,and the TMS MEP detection system designed in this study successfully recorded TMS MEP waveforms on the dorsal side of the first interosseous muscle in the hand,thus demonstrating the feasibility of the system.