Subject-specific vibrotactile feedback for improving balance in older adults

描述(申请人提供)：衰老有助于姿势控制的改变，老年人比年轻人更不稳定，更容易摔倒。许多经历跌倒的老年人往往有损害平衡的感觉缺陷，如前庭功能障碍。因此，开发一种能够提供有关平衡的额外感觉信息的平衡假体对有跌倒风险的老年人具有明显的临床意义。感觉替代平衡假体的目的是增加可用于平衡的感觉信息，以补偿自然感觉功能的丧失或减弱。振动-触觉反馈已被证明在减少站立时对平衡扰动的低频身体摇摆(低于约0.5赫兹)是有效的。然而，目前的设备往往会导致高频身体摇摆的不受欢迎的增加，这可以说与提高稳定性的目标背道而驰，特别是在老年人中，他们更容易摔倒，而且在更高频率下的摇摆已经比年轻人更大。此外，与其他感官假体(如助听器)不同，当前的振动-触觉平衡假体在很大程度上采用了“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，需要针对特定对象的设计来提高在更广泛的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，我们的目标是利用工程系统识别方法，实现并测试一种新的特定于受试者的振动触觉反馈(VTF)设计，该设计将减少老年人在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，应该会降低跌倒的风险，这一直与高频摇摆有关。这项拟议的研究是评估开发用户定制的VTF假体的可行性的必要的第一步，以实现特定的减少老年人站立时的身体摇摆和增加稳定性。在这项研究中获得的知识将有助于促进VTF在更复杂的姿势控制任务中的使用。

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.