术中神经监测系统设计与实现

Design and implementation of intraoperative nerve monitoring system

在传统甲状腺手术中,临床医生凭借肉眼识别,很难有效判定喉返神经位置,容易导致喉返神经损伤,而喉返神经损伤会导致患者无法正常说话甚至危及生命。使用术中神经监测技术,有效识别神经信号,避免术中损伤神经,本文详细介绍术中神经监测系统的设计与实现方法。该系统主要由主控模块、电流刺激模块以及神经信号采集模块组成,主控模块采用了ARM+FPGA双核架构,实现了电流刺激模块输出脉冲电流以及信号采集模块中的A/D转化功能,同时对采集模块采集的数据进行处理;电流刺激模块以高精度D/A转化芯片为核心设计电流源电路,用来调控电流脉冲的强度和脉宽;采集模块以高精度A/D模数转化芯片为核心适配低噪放大电路,实现神经信号的采集功能。使用本系统进行小猪喉返神经模拟临床人体监测实验以及在医院进行临床实验验证,证明本系统能够有效激发喉返神经信号并识别到神经信号,满足临床医生需求。

In traditional thyroid surgery,it is difficult for clinicians to effectively determine the position of the recurrent laryngeal nerve by visual recognition.It is prone to recurrent laryngeal nerve injury,which lead to patients unable to speak normally and even endanger lives.Intraoperative nerve monitoring(IONM)techniques is useful for effectively identifying nerve signals and thus avoiding intraoperative nerve injury.This paper introduces the design and implementation of IONM in detail.The system consists of main control module,current stimulation module and EMG acquisition module.The main control module adopts ARM+FPGA dual-core architecture to realize the current stimulation module and signal acquisition module.At the same time,the data collected by the acquisition module is processed.The current stimulation module uses high-precision D/A conversion chip as the core to design the current source circuit,which is used to control the intensity and pulse width;The acquisition module adopts high-precision A/D analog conversion chip as the core and adapts low noise amplifier circuit to realize the acquisition of neural EMG signal.The recurrent laryngeal nerve experiment and clinical experiment were carried out in this system respectively.It is proved that this system has ability effectively to stimulate recurrent laryngeal nerve signal and recognize nerve EMG signal,which meets the needs of clinicians.