SKIN BIOMECHANICS AND MECHANORECEPTOR RESPONSE

该项目的主要目标仍然是调查 灵长类指尖生物力学与生物力学的关系 皮肤机械感受器在触觉感觉中的反应。在 在过去的五年中，计算方法在 灵长类指尖理想化模型的力学分析 有助于更深入地理解接触的机理 在皮肤和不同形状的物体之间， 通过皮肤的机械信号，并将它们传递到 皮肤机械感受器产生的神经冲动。这样做的具体目的是 建议(L)逐步完善模型，使之接近 近似灵长类动物的几何和材料特性 指垫，(2)扩展按下或按下的刺激种类 在模型上描边以包括更多形状、柔和对象和 微结构，以及(3)进行一系列生物力学实验 在体内条件下使用各种技术，包括使用 视频显微镜、核磁共振成像(MRI)和计算机- 受控机械刺激器。型号的顺序将是 通过将他们的预测与适当的 生物力学和神经生理学实验的数据。 这些调查的起点是三维 已经使用经验模型开发的齐次模型 猴和人指尖外部几何形状的测量 使用视频显微镜系统。线性化和线性化的必备软件 均质与非均质的非线性有限元分析 模型，以及各种计算机平台的使用 (包括麻省理工学院的超级计算机)进行大量计算 都经过了测试和验证。模型改进的主要阶段 包含基于MRI的逼真内部几何图形的合并 非均匀模型，指垫的粘弹性行为基于 将视频显微镜与几何学和机械学相结合的实验 基于精细生物力学实验的乳头脊行为 用高精度的刺激器。这些实验旨在帮助 该模型的开发，并与以前获得的 生物力学和神经生理学数据，将严格用于 验证指垫和转换机构的模型。长 这样一种对起源和发展的定量理解的任期效益 触觉信息的机制将包括良好的发展 辅助康复的触觉敏感度评价试验 手感障碍者与触觉交流的设计 为视障和聋人提供助听器。

The primary goal of this project continues to be the investigation of the relationship between the biomechanics of the primate fingertip and responses of cutaneous mechanoreceptors during tactile sensing. In the past five years, the application of computational methods to the mechanistic analysis of idealized models of the primate fingertip has contributed to a deeper understanding of the mechanics of contact between the skin and objects of differing shapes, the transmission of the mechanical signals through the skin, and their transduction into neural impulses by cutaneous mechanoreceptors. The specific aims of this proposal are (l) to gradually refine the models so that they closely approximate the geometrical and material properties of the primate fingerpad, (2) to expand the variety of stimuli that are pressed or stroked on the models to include more shapes, soft objects and microtextures, and (3) to perform a series of biomechanical experiments under in vivo conditions using a variety of techniques including the use of videomicroscopy, Magnetic Resonance Imaging (MRI) and computer- controlled mechanical stimulators. The sequence of models will be verified at each stage by comparing their predictions with appropriate data from biomechanical and neurophysiological experiments. Starting points for these investigations are the three dimensional homogeneous models that have already been developed using empirical measurements of the external geometry of monkey and human fingertips using a videomicroscopy system. The necessary software for linear and nonlinear finite element analyses of homogeneous and nonhomogeneous models, as well as the usage of the various computer platforms (including the MIT supercomputer) for the large number of computations have been tested and verified. The major stages of model refinement consist of incorporation of realistic internal geometry based on MRI for nonhomogeneous models, viscoelastic behavior of the fingerpad based on experiments using videomicroscopy, together with geometry and mechanical behavior of papillary ridges based on fine biomechanical experiments with a high precision stimulator. The experiments are designed to help the model development, and together with the previously obtained biomechanical and neurophysiological data, will serve to rigorously verify the models of the fingerpads and transduction mechanisms. Long term benefits of such a quantitative understanding of the origins and mechanisms of tactile information would include the development of good tests for the evaluation of tactile sensibility to aid in rehabilitation of hand-impaired individuals and the design of tactile communication aids for visually impaired and deaf individuals.