School of Electrical and Electronic Engineering, University of Adelaide, Adelaide, Australia.
School of Science, Western Sydney University, Penrith, New South Wales, Australia.
Bioelectromagnetics. 2023 Oct-Dec;44(7-8):181-191. doi: 10.1002/bem.22486. Epub 2023 Nov 1.
Electric-field stimulation of neuronal activity can be used to improve the speed of regeneration for severed and damaged nerves. Most techniques, however, require invasive electronic circuitry which can be uncomfortable for the patient and can damage surrounding tissue. A recently suggested technique uses a graft-antenna-a metal ring wrapped around the damaged nerve-powered by an external magnetic stimulation device. This technique requires no electrodes and internal circuitry with leads across the skin boundary or internal power, since all power is provided wirelessly. This paper examines the microscopic basic mechanisms that allow the magnetic stimulation device to cause neural activation via the graft-antenna. A computational model of the system was created and used to find that under magnetic stimulation, diverging electric fields appear at the metal ring's edges. If the magnetic stimulation is sufficient, the gradients of these fields can trigger neural activation in the nerve. In-vivo measurements were also performed on rat sciatic nerves to support the modeling finding that direct contact between the antenna and the nerve ensures neural activation given sufficient magnetic stimulation. Simulations also showed that the presence of a thin gap between the graft-antenna and the nerve does not preclude neural activation but does reduce its efficacy.
电场刺激神经元活动可用于加快切断和受损神经的再生速度。然而，大多数技术都需要侵入式电子电路，这可能会让患者感到不适，并损坏周围组织。最近提出的一种技术使用了一种移植天线——一个包裹在受损神经上的金属环，由外部磁刺激设备供电。该技术不需要电极和内部电路，也不需要跨越皮肤边界或内部供电的引线，因为所有的电力都是通过无线方式提供的。本文研究了允许磁刺激设备通过移植天线引起神经激活的微观基本机制。创建了一个系统的计算模型，并发现，在磁刺激下，金属环边缘会出现发散电场。如果磁刺激足够，这些场的梯度可以在神经中触发神经激活。还对大鼠坐骨神经进行了体内测量，以支持建模结果，即天线与神经的直接接触确保了在有足够磁刺激的情况下进行神经激活。模拟还表明，移植天线和神经之间存在薄的间隙不会排除神经激活，但会降低其效果。
