Subject-specific vibrotactile feedback for improving balance in older adults

描述（由申请人提供）：年龄增长导致姿势控制的改变，老年人比年轻人更不稳定，更容易跌倒。许多经历过跌倒的老年人经常有感觉缺陷，损害平衡，如前庭功能障碍。因此，开发一种平衡假体，可以提供额外的平衡感官信息，对有跌倒风险的老年人具有明显的临床重要性。感觉替代平衡假肢旨在增加可用于平衡的感觉信息，以补偿失去或减少的自然感觉功能。振动触觉反馈已被证明是有效的减少低频身体摇摆（低于0.5赫兹），以响应平衡扰动而站立。然而，目前的器械往往会导致不受欢迎的高频身体摇摆的增加，这可以说是与提高稳定性的目标背道而驰，特别是对于老年人，他们更容易摔倒，并且已经比年轻人更频繁地摇摆。此外，与其他感官假肢（如助听器）不同，助听器是根据用户进行微调的，目前的振动触觉平衡假肢主要采用“一刀切”的方法，因为它们对所有受试者使用相同的设置（即参数值）。我们的分析表明，这种方法有助于增加高频身体摇摆，并且需要针对特定主题的设计来提高在更宽频率范围内的稳定性，特别是在高频时不增加摇摆。在这项研究中，我们的目标是使用工程系统识别方法，并测试一种新的受试者特异性振动触觉反馈（VTF）设计，该设计将减少老年人站立时因平衡扰动而产生的高频姿势摇摆。减少老年人的高频摇摆将使他们的摇摆看起来更像年轻人的自然摇摆，并且应该减少跌倒的风险，这与高频摇摆有关。拟议的研究是评估开发用户定制VTF假体的可行性的必要的第一步，以实现特定的减少身体摇摆和增加老年人站立时的稳定性。在这项研究中所获得的知识应该有助于推进VTF在更复杂的姿势控制任务中的应用。

DESCRIPTION (provided by applicant): Aging contributes to changes in postural control, and older adults are less stable and more prone to falls than young adults. Many older people who experience a fall often have sensory deficits that impair balance, such as vestibular dysfunction. Accordingly, the development of a balance prosthesis that can provide additional sensory information about balance has clear clinical importance for older persons at risk for falls. Sensory substitution balance prostheses aim to augment sensory information available for balance in order to compensate for lost or diminished natural sensory function. Vibro-tactile feedback has been shown to be effective at reducing low frequency body sway (below about 0.5 Hz) in response to balance perturbations while standing. However, current devices tend to cause an undesirable increase in high frequency body sway, which is arguably counter to the aim of improving stability, especially in older adults, who are more prone to falls, and already sway more than young adults at higher frequencies. In addition, unlike other sensory prostheses such as hearing aids, which are fine-tuned to the user, current vibro-tactile balance prostheses largely employ a "one size fits all" approach, in that they use the same settings (i.e. parameter values) for all subjects. Our analysis has shown that this approach contributes to increased high frequency body sway, and that a subject-specific design is required to improve stability over a broader range of frequencies and, especially, to not increase sway at high frequencies. In this research, we aim to implement, using engineering system identification methods, and test a novel subject-specific vibrotactile feedback (VTF) design that will reduce high frequency postural sway of older adults in response to balance perturbations while standing. Reducing high frequency sway in older adults will cause their sway to look more like the natural sway of young adults, and should reduce fall risk, which has been associated with high frequency sway. The proposed research is a necessary first step to assess the feasibility of developing a user-customized VTF prosthesis, to achieve specific reductions in body sway and increased stability in older adults while standing. The knowledge to be gained in this study should be useful for advancing the use of VTF for more complex postural control tasks.