Development of surrogate spinal cords for the evaluation of electrode arrays used in intraspinal implants.
Development of surrogate spinal cords for the evaluation of electrode arrays used in intraspinal implants.
复制标题
DOI：
10.1109/tbme.2013.2241061
复制
发表时间：
2013-06
期刊：
影响因子：
--
通讯作者：
Elias AL
中科院分区：
文献类型：
--
作者：
Cheng C;Kmech J;Mushahwar VK;Elias AL
我们报告了替代脊髓的发展，以评估脊柱内植入物的电极阵列的机械适用性。对替代脐带缆的候选材料（包括硅橡胶弹性体和明胶水凝胶）的机械和界面性能进行了测试。使用动态力学分析的弹性模量的特点，并与文献中的实际人类脊髓的值进行比较。在静态条件下，测量将替代绳固定到指定深度所需的力，以获得数值。重要的是，除了通常考虑的机械性能之外，为了量化表面性能，通过以受控速率将针从每个帘线中拉出来测量界面摩擦力。然后将测得的力与从大鼠脊髓中获得的力进行比较。甲醛交联明胶，12重量%的水，被确定为最合适的材料的替代脊髓的建设。为了证明替代脊髓在评估各种电极阵列的行为中的效用，脊髓植入了两种类型的脊柱内电极阵列（一种由单独的微丝制成，另一种由与固体基底锚定的微丝制成），并且评估了脊髓在伸长下的变形。结果表明，替代模型模拟的力学和界面特性的脊髓，并能够在体外筛选的脊柱内植入物。
We report the development of a surrogate spinal cord for evaluating the mechanical suitability of electrode arrays for intraspinal implants. The mechanical and interfacial properties of candidate materials (including silicone elastomers and gelatin hydrogels) for the surrogate cord were tested. The elastic modulus was characterized using dynamic mechanical analysis, and compared with values of actual human spinal cords from the literature. Forces required to indent the surrogate cords to specified depths were measured to obtain values under static conditions. Importantly, to quantify surface properties in addition to mechanical properties normally considered, interfacial frictional forces were measured by pulling a needle out of each cord at a controlled rate. The measured forces were then compared to those obtained from rat spinal cords. Formaldehyde-crosslinked gelatin, 12 wt% in water, was identified as the most suitable material for the construction of surrogate spinal cords. To demonstrate the utility of surrogate spinal cords in evaluating the behavior of various electrode arrays, cords were implanted with two types of intraspinal electrode arrays (one made of individual microwires and another of microwires anchored with a solid base), and cord deformation under elongation was evaluated. The results demonstrate that the surrogate model simulates the mechanical and interfacial properties of the spinal cord, and enables in vitro screening of intraspinal implants.