时间相干电场的外周神经无损刺激

外周神经电刺激可用于运动康复和慢性神经痛治疗,但目前具有空间选择性的无损刺激仍是一个有待解决的问题。提出一种基于时间相干(TI)电场的外周神经选择性无损电刺激方法,对大鼠坐骨神经进行实验,在其大腿腹侧与背侧皮肤上以平行于神经的方向布置刺激电极,通过相干电场扫描,将TI刺激峰值定位到神经上进行选择性刺激。结果表明,该方法可以在预先不知道神经确切位置的情况下通过扫描得出将刺激电场作用到神经的最佳电参数,从而实现对神经的选择性无损刺激,而且在刺激作用点不变的前提下实现刺激强度的控制。在此基础上研究TI电场对大鼠坐骨神经的刺激阈值I_T,测量固定频差Δf=0.5 Hz(n=12),改变频率f=1～6 kHz与固定f=5 kHz(n=11),改变频差Δf=0.5～10 Hz下的I_T,并将其和等幅kHz电场(n=7)的I_T进行比较。结果表明,等幅kHz电场的I_T显著高于TI电场(P<0.05),而且不同频率f下的I_T也有显著性差异(P<0.05),而不同频差Δf下的I_T却没有显著性差异(P>0.05),说明TI电流对大鼠坐骨神经的I_T受f影响而不受Δf影响,且刺激阈值I_T与频率f成正比关系。

Peripheral Nerve Noninvasive Stimulation via Temporally Interfering Electric Fields

Peripheral nerve electrical stimulation can be used for sports rehabilitation and chronic neuralgia treatment, but the current spatially selective non-invasive stimulation remains a problem to be solved. A non-invasive peripheral nerve electrical stimulation method that features a certain level of selectivity was developed based on the temporally interfering (TI) electric field. The rat sciatic nerve was tested and the stimulating electrodes were arranged in the direction parallel to the nerve on the ventral and dorsal skin of the thigh. The TI stimulation peak was localized to the nerve for selective stimulation by the scan of interfering electric field. The results showed that optimal electrical parameters, through which the electrical field was delivered to the nerve, could be acquired by scanning without knowing the exact location of the nerve in advance. Thus, selective non-invasive stimulation of nerves could be achieved and the control of the intensity of stimulation could be realized under the premise of keeping the stimulation focus fixed. On this basis, the stimulation threshold I_T of TI electric field on rat sciatic nerve was explored and I_T of different conditions were measured as well, including fixing frequency difference Δf=0.5 Hz (n=12), changing the frequency f=1～6 kHz and fixed f=5 kHz (n=11), changing the frequency difference Δf=0.5～10 Hz, at the same time, compared with that of equal amplitude kHz electric field (n=7). The results demonstrated that the I_T of the equal-amplitude kHz electric field is significantly higher than that of the TI electric field (P<0.05), and there is a significant difference in the I_T at different frequencies f(P<0.05), while no remarkable difference in the I_T of different Δf(P<0.05), which was different between two frequencies, was observed, indicating that the stimulation threshold of TI electric field on rat sciatic nerve was affected by frather than Δf, and the stimulation threshold I_T was proportional to the frequency f.