Automatic Control Laboratory, ETH Zurich, 8092 Zurich, Switzerland.
IEEE Trans Neural Syst Rehabil Eng. 2010 Jun;18(3):255-62. doi: 10.1109/TNSRE.2009.2039807. Epub 2010 Jan 12.
Transcutaneous electrical stimulation (TES) is a technique to artificially activate motor nerves and muscles. It can be used for rehabilitation or the restoration of lost motor functions, e.g., in subjects with brain or spinal cord lesions. Apart from selectively activating motor nerves and muscles, TES activates sensory fibers and pain receptors, producing discomfort and pain. Clinicians try to minimize discomfort by optimizing stimulation parameters, electrode location, and electrode size. There are some studies that found optimal electrode sizes for certain stimulation sites (e.g., gastrocnemius), however the underlying effects why certain electrode sizes are preferred by patients is not well understood. We used a TES model consisting of a finite element (FE) model and a nerve model to assess the influence of different electrode sizes on the selectivity and the perceived comfort for various anatomies. Motor thresholds calculated using the TES model were compared with motor thresholds that were obtained from measurements performed on the forearm of ten human volunteers. Results of the TES model indicate that small electrodes (0.8 x 0.8 cm(2)) are more comfortable for thin fat layers (0.25 cm) and superficial nerves (0.1 cm) and larger electrodes (4.1 x 4.1 cm(2)) are more comfortable for thicker fat layers (2 cm) and deeper nerves (1.1 cm) at a constant recruitment.
经皮电刺激（TES）是一种人工激活运动神经和肌肉的技术。它可用于康复或恢复失去的运动功能，例如，在大脑或脊髓损伤的患者中。除了选择性地激活运动神经和肌肉外，TES 还会激活感觉纤维和疼痛感受器，从而产生不适和疼痛。临床医生试图通过优化刺激参数、电极位置和电极尺寸来最小化不适感。有一些研究发现了特定刺激部位（例如，腓肠肌）的最佳电极尺寸，但是，为什么某些电极尺寸受到患者的青睐的根本原因尚不清楚。我们使用了一个由有限元（FE）模型和神经模型组成的 TES 模型，以评估不同电极尺寸对各种解剖结构的选择性和感知舒适度的影响。使用 TES 模型计算的运动阈值与在十名人类志愿者前臂上进行测量获得的运动阈值进行了比较。TES 模型的结果表明，对于较薄的脂肪层（0.25cm）和较浅的神经（0.1cm），小电极（0.8 x 0.8cm²）更舒适，而对于较厚的脂肪层（2cm）和较深的神经（1.1cm），大电极（4.1 x 4.1cm²）在保持募集的情况下更舒适。
