Department of Mechanical Engineering, National Cheng Kung University, 1 Ta-Hsueh Road, Tainan 701, Taiwan, ROC.
J Biomech. 2010 Apr 19;43(6):1118-24. doi: 10.1016/j.jbiomech.2009.12.002. Epub 2010 Jan 12.
Biomechanical properties of nerves were investigated using the quasi-linear viscoelastic model. An improved parameter estimation technique based on fast convolution was developed and tested in sciatic nerves of normal and diabetic rats. In situ dynamic compression response of sciatic nerves was obtained by a modified custom-designed compression system. Six normal and five diabetic neuropathic Wistar rats were used. The model derived from the high strain rate (0.1 s(-1)) data could predict the responses of lower strain rates (0.05 and 0.01 s(-1)) satisfactorily. The computation time was cut down 49.0% by using the newly developed technique without increasing the root-mean-square error. The percentage of stress relaxation of the diabetic and normal rats, calculated directly from the experimental data, was not significantly different (51.03+/-1.96% vs. 55.97+/-5.89%, respectively; p=0.247). After model fitting, compared with the QLV parameters of normal nerves, the smaller parameter C for diabetic nerves (0.27+/-0.06 vs. 0.20+/-0.02, p < 0.05) indicated that diabetic nerves had a smaller amplitude of viscous response (stress relaxation). The larger parameter tau(2) of diabetic nerves (199+/-153 s vs. 519+/-337 s, p<0.05) implied that diabetic nerves needed a longer relaxation period to reach equilibrium.
采用准线性粘弹性模型研究了神经的生物力学特性。开发并测试了一种基于快速卷积的改进参数估计技术，用于正常和糖尿病大鼠的坐骨神经。通过改良的定制压缩系统获得坐骨神经的原位动态压缩响应。使用了 6 只正常和 5 只糖尿病神经病变的 Wistar 大鼠。从高应变率（0.1 s(-1))数据得出的模型可以很好地预测较低应变率（0.05 和 0.01 s(-1))的响应。通过使用新开发的技术，计算时间减少了 49.0%，而均方根误差没有增加。直接从实验数据计算得出的糖尿病和正常大鼠的应力松弛百分比没有显著差异（分别为 51.03+/-1.96%和 55.97+/-5.89%；p=0.247）。经过模型拟合，与正常神经的 QLV 参数相比，糖尿病神经的较小参数 C（0.27+/-0.06 对 0.20+/-0.02，p < 0.05）表明糖尿病神经的粘性响应（应力松弛）幅度较小。糖尿病神经的较大参数 tau(2)（199+/-153 s 对 519+/-337 s，p<0.05）表明糖尿病神经需要更长的松弛时间才能达到平衡。
