High-speed Data Acquisition And Research On Signal Extraction Algorithm Of Delicate Evoked Potential Monitor

The Evoked Potential signal is the neural activity on the epidermis resulting from the visual, auditory or somatosensory stimulus to a person. The amplitude of the signal is very low, of only0.1-20uV. Therefore the EP is easy to be submerged in the other EEG signals or electromagnetic interference. The evoked potential instrument widely used in clinical detection.The precision Evoked Potential instrument in this article use detecting technology of the weak signal and synchronous acquisition technology of real-time and high-speed data, and converts the enlarged physiological signal to digital signal, then the digital signal will be transmitted to the FPGA&ARM controller, which sends the information to PC via USB2.0mode.The data processing module is mainly implemented by the FPGA controller. The module of the modular designed of the top-down system according to pipeline design, integration and maintenance for the system; the cache module data, the parallel data stream ping-pong operation using two DCFIFO, greatly improve the throughput of data. Asynchronous FPGA and ARM host controller clock domain communication, the combination of the three methods using synchronous detection, asynchronous FIFO cache, half step dislocated synchronization method, removed the Metastable state between Asynchronous clock domains in the high-speed synchronous system in the main control system suppressing under the control by high-speed clock.Data processing system to collect evoked potential signal through the analog filter is simple, which contains various kinds of interference signal, such as EEG (EEG), ECG interference, frequency interference, the characteristic signals are extracted using digital signal processing technology. Based on the superposed average noise reduction algorithm and adaptive interference cancellation technology (3A Technology) analysis, proposed the Adaptive algorithm by arc tangent correction based on IIR filter for feature extraction of signal signal single visual, auditory evoked potential, and with the traditional averaging method are compared, for single extraction of evoked potential signal the algorithm to do the actual discussion. Analysis of test results available, three methods of synchronization method proposed in this paper combines. Effective remove on the metastable state of the high in the system; the proposed Adaptive algorithm by arc tangent correction based on IIR filter can be single extraction of Evoked Potential signal, the system can be used for clinical detection of evoked potentials.