A Nonlinear Dynamical Technique for Improving the Function of the Human Postural Control System

人类的直立姿势是由一个复杂的控制系统调节的，该系统涉及许多不同的感觉模式，包括体感系统。这个项目的目标是开发一种生物工程技术，可以用来增强人类受试者的脚和脚踝的体感，从而提高人类姿势控制系统的性能。最近，人们对随机共振（SR）产生了相当大的兴趣，随机共振是一种现象，其中非线性系统对亚阈值输入信号的响应通过存在特定水平的噪声来优化。sr型动力学已在神经元模型、大鼠皮肤感觉神经元、人类肌肉纺锤体和人类触觉系统中得到证实。这些研究表明，人为地将噪声引入感官系统以提高其检测亚阈值信号的能力是可能的。然而，迄今为止，sr型动力学的生物工程应用仍然有限。该项目将致力于开发一种基于噪声的生物工程技术，以改善人体姿势控制系统的功能。具体来说，在这个项目中，将开发一种非侵入性系统，用于将电子噪声应用于人类受试者的脚和脚踝。该系统将由部分由导电材料制成的短袜电极组成。该系统将用于对25名健康的年轻受试者进行的一系列心理物理实验。这些实验将被设计用来测试人类受试者的背屈/跖屈检测阈值随着电噪声的增加而改变的假设。此外，还将对这25名受试者进行一系列静立实验。这些实验将被设计来验证一个假设，即噪音引起的背屈/跖屈检测阈值的变化会改变姿势控制系统的静立动态。这个项目可能会导致一种非侵入性的、基于噪音的技术的发展，这种技术可以用来增强人类的体感，从而改善人类姿势控制系统的性能。这项工作可能对躯体感觉阈值升高的个体，如老年人和周围神经病变患者具有重要的影响。这种体感系统的变化可能使人容易跌倒。因此，该项目的结果最终将有助于减少跌倒的频率、成本和发病率。

9908034CollinsUpright stance in humans is regulated by a complex control system that involves a number of different sensory modalities, including the somatosensory system. The goal of this project is to develop a bioengineering technique that can be used to enhance somatosensation in the feet and ankles of human subjects and thereby improve the performance of the human postural control system. Recently, there has been considerable interest in stochastic resonance (SR) which is a phenomenon wherein the response of a nonlinear system to a subthreshold input signal is optimized by the presence of a particular level of noise. SR-type dynamics have been demonstrated in neuronal models, rat cutaneous sensory neurons, human muscle spindles and the human touch-sensation system. These studies indicate that it is possible to introduce noise artificially into a sensory system in order to improve its ability to detect subthreshold signals. To date, however, bioengineering applications of SR-type dynamics have been limited. This project will be directed towards developing a noise-based bioengineering technique for improving the function of the human postural control system. Specifically, in this project, a non-invasive system for applying electrical noise to the feet and ankles of human subjects will be developed. This system will consist, in part of sock electrodes, which are made of conductive material. This system will be used in a series of psychophysical experiments that will be conducted on 25 healthy young subjects. These experiments will be designed to test the hypothesis that dorsiflexion/plantarflexion detection thresholds in human subjects are changed with the addition of electrical noise. A series of quiet-standing experiments will also be conducted on the 25 subjects. These experiments will be designed to test the hypothesis that noise-induced changes to dorsiflexion/plantarflexion detection thresholds alter the quiet-standing dynamics of the postural control system. This project could lead to the development of a non-invasive, noise-based technique that could be used to enhance somatosensation in humans and thereby improve the performance of the human postural control system. This work could have important ramifications for individuals with elevated somatosensory thresholds, such as older adults and patients with peripheral neuropathies. Such changes to the somatosensory system may predispose individuals to falls. Accordingly, the results of this project could eventually serve to reduce the frequency, cost, and morbidity of falling.