Lertmanorat Zeng, Montague Fred W, Durand Dominique M
Department of Electrical Engineering, Mahidol University, Salaya 73170, Thailand.
IEEE Trans Neural Syst Rehabil Eng. 2009 Apr;17(2):176-82. doi: 10.1109/TNSRE.2008.2009307.
One of the goals of peripheral nerve cuff electrode development is the design of an electrode capable of selectively activating a specific population of axons in a common nerve trunk. Several designs such as the round spiral electrode or the flat interface nerve electrode (FINE) have shown such ability. However, multiple contact electrodes require many leads, making the implantation difficult and potentially damaging to the nerve. Taking advantage of the flat geometry of the FINE, multiplexers were embedded within the cuff electrode to reduce the number of leads needed to control 32 channels. The circuit was implemented on a polyimide film using off-the-shelf electronic components. The electronic module was surface-mounted directly onto the electrode's flat substrate. Two circuit designs were designed, built, and tested: 1) a single supply design with only two wires but limited to cathodic-first pulse and 2) a dual-supply design requiring three lead wires but an arbitrary stimulation waveform. The electrode design includes 32 contacts in a 1 mm x 8 mm opening. The contact size is 300 microm x 400 microm with access resistance less than 1 k ohm. This electrode is not intended for long-term use, but developed as a feasibility study for future development using low-water-absorption materials such as liquid crystal polymer and an application specific integrated circuit.
外周神经袖套电极开发的目标之一是设计一种能够选择性激活共同神经干中特定轴突群的电极。几种设计，如圆形螺旋电极或平面界面神经电极（FINE）已展现出这种能力。然而，多触点电极需要许多导线，这使得植入困难且可能对神经造成损伤。利用FINE的扁平几何形状，复用器被嵌入袖套电极内，以减少控制32个通道所需的导线数量。该电路使用现成的电子元件在聚酰亚胺薄膜上实现。电子模块直接表面安装在电极的扁平基板上。设计、构建并测试了两种电路设计：1）单电源设计，仅需两根导线，但仅限于阴极优先脉冲；2）双电源设计，需要三根导线，但可产生任意刺激波形。电极设计在1毫米×8毫米的开口中有32个触点。触点尺寸为300微米×400微米，接入电阻小于1千欧。这种电极并非用于长期使用，而是作为使用低吸水性材料（如液晶聚合物）和专用集成电路进行未来开发的可行性研究而开发的。
