Towards truly bio-integrative mobility assistance

外骨骼装置的使用和开发正在迅速增加。这些设备用于协助日常活动，帮助康复或提高能力。虽然在小目标群体中实现这些目标的成功率很高（Young和Ferris，2016），但在解决更广泛人群的一系列条件和需求方面仍然存在许多问题。主要问题之一源于硬装置与人体软组织之间的界面。据Cherry等人（2016）估计，用于移动外骨骼的高达50%的功率被软组织的压缩吸收。这可能是常见的深层纯粹组织损伤的原因，其可能最终导致溃疡（Highsmith等人，2011年）。毫不奇怪，这些问题限制了这些辅助设备的使用，从而限制了它们的成功率。我的博士学位将专注于这个身体-设备界面，这是尚未被很好地理解，最终目的是根除与之相关的问题，如果这项研究证明是成功的，无数的人可以受益，从帮助老年人在日常活动中，脊髓患者接受康复，以提高截肢者的独立性和减少后续预约的数量。此外，将把重点放在降低成本上，以使第三世界国家的病人能够获得服务。身体-设备接口的研究将集中在两个关键应用：1。截肢者的下肢假肢接受腔;以及2.柔软可穿戴的老年人下肢辅助装置。不适导致患者不愿使用这些辅助设备，导致患者高度依赖他人，无法自由走动。其他问题，如残端体积波动和水肿，将需要患者参加多次随访预约，以改变假肢接受腔或可穿戴设备的适配性（Sanders和Fatone，2015）。我的研究将集中在人类组织和机器材料之间的智能下肢接口的开发上，这些接口将适应患者不断波动的条件，并将减轻深度纯粹的组织损伤。例如，这可以通过仅在需要时和需要处支撑残肢来实现。或者，可以制造完全柔软的假肢接受腔和辅助装置，完全消除硬装置与软组织之间的界面。为了实现这一点，需要在整个步态周期中量化和绘制深层组织内的剪切和体积波动。需要研究哪种方法能够提供最准确的表示。考虑的方法将包括临床测量，如超声（可能是3D和光谱）和扩散张量成像（DTI）以及可穿戴测量，如压力和音频。一旦确定了这些元素，就可以使用有限元（FE）建模来帮助可视化发生的组织应力和应变，为设计自适应内衬、新插座或生物界面器械（包括材料、传感器和驱动选择）提供良好的起点。一旦创建了原型，就需要在受试者身上进行测试。这可以通过使用Motek Caren系统（Buis，University of Strathclyde）来完成，其允许步态的准确分析，特别注意步态对称性。潜在的长期舒适性益处需要通过更长的试验期来确定，但将在实验心理学（肯特，UoB）和用户研究（Turton，UWE）专家的指导下，使用正式的定性评价进行初步评价。最后，需要解决新设备的美观问题，因为这将最终决定患者使用它并从中受益的可能性。

The use and development of exoskeletal devices are rapidly increasing. These devices are used in order to assist in every-day activities, aid in rehabilitation, or increase abilities. Although success rates are high in achieving these goals in small targeted groups (Young and Ferris, 2016), many problems still exist in addressing the range of conditions and needs in the wider population. One of the main problems originates from the interface between the hard device and the soft tissue of the human body. It is estimated by Cherry et al. (2016) that up to 50% of the power supplied to move the exoskeleton is absorbed by compression of the soft tissue. This could be the cause of the common deep sheer tissue injury which could ultimately lead to ulcerations (Highsmith et al., 2011). It is no surprise that these problems limit the use of these assistive devices and therefore their success rates. My PhD will focus on this body-device interface which is not yet well understood, with the ultimate aim of eradicating the problems associated with it. If this research proves successful, countless number of people could benefit, from assisting the elderly in everyday activities, to spinal cord patients undergoing rehabilitation, to increasing independence in amputees and reducing the number of follow up appointments required. In addition, an emphasis will be put on cost reduction in an attempt to allow accessibility to patients in third world countries. Study of the body-device interface will focus on two key applications: 1. lower limb prosthetic sockets for amputees; and 2. soft wearable lower limb assist devices for the elderly. Discomfort leads to the reluctance of using these assistive devices, causing patients to become highly dependent on others, unable to move around freely. Additional problems such as fluctuations in residual stump volume and oedema will require the patient to attend multiple follow-up appointments in order to alter the fit of the prosthetic socket or wearable device (Sanders and Fatone, 2015). My research will focus on the development of intelligent lower limb interfaces between human tissue and machine materials that would adapt to the patients' ever fluctuating conditions and that would alleviate the deep sheer tissue injury. This can be achieved, for example, by supporting the residual limb only when and where required. Alternatively, totally soft prosthetic sockets and assist devices may be created, eliminating the hard-device-to-soft-tissue interface altogether.In order to achieve this, sheer within the deep tissue and volume fluctuations need to be quantified and mapped throughout the gait cycle. A study would need to be conducted as to which method would provide the most accurate representation. Methods considered will include in-clinic measurements such as ultrasound (potentially 3D and spectrography) and Diffusion Tensor Imaging (DTI) and wearable measurements such as pressure and audio-frequency. Once these elements have been determined, Finite Element (FE) modelling could be used to help visualise the tissue stresses and strains occurring, providing a good starting point for designing an adaptive liner, new socket or bio-interface device, including material, sensor and actuation selection. Once a prototype has been created, it would need to be tested on subjects. This could be done with the use of a Motek Caren system (Buis, University of Strathclyde), allowing accurate analysis of gait, paying particular attention to gait symmetry. The potential longer term comfort benefits would need to be determined with a longer trial period, but initial evaluation will be conducted using formal qualitative evaluations with guidance from experts in experimental psychology (Kent, UoB) and user studies (Turton, UWE). Finally, the aesthetics of the new device would need to be addressed, as this will ultimately determine the patients' likelihood of utilising it and thus benefitting from it.