基于2^n伪随机复合频率信号的神经肌肉电刺激系统设计

目的：每一块肌肉都是由众多肌纤维组成，每一组肌纤维的固有频率不同，在对肌肉进行电刺激时，使用单一频率的电刺激不能满足同时对多组肌纤维进行刺激，不能达到最有效的电刺激作用，因此我们设计了一种基于伪随机信号的复合频率电刺激仪，能在一个刺激周期内实现多个频率的电刺激。方法：设计了一个以STC12C5410AD单片机为核心控制芯片的伪随机信号神经肌肉电刺激仪系统，采用串口实现上下位机的通讯，通过软件编程，上位机发送主频数、主频频率、间歇时间和刺激时间各项参数指令，由单片机控制输出两路伪随机脉冲信号，并通过逆变电路实现伪随机信号的输出，在逆变电路中加入电流监测电阻，实时监测输出信号的电流大小，将其控制在人体安全电流10mA以下，保证了用户的使用安全。结果：研制出的电刺激仪能产生1kHz以下多种主频信号的复合，根据主频数和主频频率的不同输出不同的复合频率信号，同时对输出电流的检测，验证了信号的安全性。结论：本文将伪随机复合频率信号运用于肌肉电刺激仪中，取代传统的单一频率电刺激仪，实现了技术上和理论上的创新，具有较高的临床实验和科研价值。

Design of Electrical Stimulation System Based on 2^n Sequence Pseudo-random Signal

Objective： A muscle is composed by a large number of muscle fibers, each fiber has its natural frequency, when stimulating on muscles, single frequency electrical stimulation can＇t meet the natural frequency of all the muscle fibers at the same time, so it can＇t be the most effective electrical stimulation .In this case, we design a electrical stimulation system based on sequence pseudo-random signal, which can stimulate with multiple frequency within a stimulation cycle. Methods： De signed a sequence pseudo-random signal electrical system with monolithic controller STCI2C5410AD as the controlling cen ter, using the serial port to realize serial communication, epigenous machine transmits the number of frequencies, frequency, in terval time and stimulation time by sottware programming. MCU control outputs two pseudo-random pulse signals, and then outputs the pseudo-random signal by inverting circuit. The current monitoring ;resistance in the inverter circuit can always moni- tor the current size of the output signal, which helps to control the current under the body safety current of 10mA, to ensure the safety of users. Results： The developed electrical stimulation can achieve the compositing of signal frequencies less than 1 kHz, output different kinds of pseudo-random signals according to different frequency and number, and have verified the safety of the signal by detecting the output current. Conclusions： The pseudo-random signal used in electrical muscle stimulation sys tem, which replaces the traditional single frequency electrical stimulation system, has achieved a technological and theoretical innovation, with a high clinical trials and scientific value.