Natural Variation in Skin Thickness Argues for Mechanical Stimulus Control by Force Instead of Displacement.
Natural Variation in Skin Thickness Argues for Mechanical Stimulus Control by Force Instead of Displacement.
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皮肤厚度的自然变化支持通过力而不是位移来控制机械刺激。
DOI：
10.1109/whc.2013.6548484
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Gerling,GregoryJ
中科院分区：
文献类型：
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作者：
Wang,Yuxiang;Marshall,KaraL;Baba,Yoshichika;Lumpkin,EllenA;Gerling,GregoryJ
对触摸刺激的神经反应受到皮肤特性以及刺激传递的影响。在这里，我们比较了由位移和力控制的刺激，并分析了随着皮肤厚度和弹性的变化，缓慢适应的 I 型传入神经对放电率的影响。使用单轴压缩测试来测量小鼠后肢皮肤（n = 5）的机械性能，从而获得一系列皮肤厚度测量值（211.6-530.6 μm）以及超粘弹性性能（平均变异系数= 0.27）。使用奥格登应变能函数将值集成到轴对称有限元模型中。这计算了表面载荷到触觉末端器官位置的传播，其中最大压缩应力及其速率被采样并线性回归到发射速率。对于观察到的皮肤厚度范围，在斜坡和保持刺激的力和位移控制下预测发射响应。在刺激的斜坡阶段，位移下的预测放电率的方差高于力控制下的（22.2 与 4.9 Hz），刺激的持续阶段也有类似的趋势（4.6 与 1.3 Hz）。鉴于样本之间的皮肤厚度差异很大，人类皮肤的厚度可能比小鼠皮肤的差异更大，因此预计使用力控制可以减少神经生理学和心理物理学反应的实验差异。
The neural response to touch stimuli is influenced by skin properties as well as the delivery of stimuli. Here, we compare stimuli controlled by displacement and force, and analyze the impact on firing rates of slowly adapting type I afferents as skin thickness and elasticity change. Uniaxial compression tests were used to measure the mechanical properties of mouse hind limb skin (n=5), resulting in a range of skin thickness measurements (211.6-530.6 μm) and hyper- and visco-elastic properties (average coefficient of variation=0.27). Values were integrated to an axisymmetric finite element model using an Ogden strain energy function. This calculated the propagation of surface loads to tactile end-organ locations, where maximum compressive stress and its rate were sampled and linearly regressed to firing rate. For the observed range of skin thickness, firing response was predicted under both force and displacement control of a ramp-and-hold stimulus. Over the ramp phase of stimulation, the variance in predicted firing rate was higher under displacement than under force control (22.2 versus 4.9 Hz) with a similar trend in the sustained phase of stimulation (4.6 versus 1.3 Hz). Given that skin thickness varies significantly between specimens, for human skin perhaps even more so than for mice, the use of force control is predicted to decrease experimental variance in neurophysiological and psychophysical responses.