Towards truly bio-integrative mobility assistance

外骨骼装置的使用和发展正在迅速增加。这些设备用于辅助日常活动，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条件和需求方面仍然存在许多问题。其中一个主要问题来自于硬设备与人体软组织之间的界面。据Cherry等人（2016）估计，高达50%用于移动外骨骼的电力是通过压缩软组织吸收的。这可能是常见的深层组织损伤的原因，最终可能导致溃疡（Highsmith et al., 2011）。毫无疑问，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尚未被很好理解的身体-设备接口，最终目标是根除与之相关的问题。如果这项研究证明是成功的，无数人将从中受益，从帮助老年人进行日常活动，到接受康复治疗的脊髓患者，到提高截肢者的独立性，以及减少所需的随访预约次数。此外，将把重点放在降低费用上，以期使第三世界国家的病人能够获得治疗。人体-设备接口的研究将集中在两个关键应用上：截肢者下肢假肢插孔；和2。老年人软性可穿戴下肢辅助装置。不适导致不愿使用这些辅助装置，导致患者高度依赖他人，无法自由活动。其他问题，如残肢体积波动和水肿，将需要患者参加多次随访预约，以改变假体窝或可穿戴设备的贴合度（Sanders和Fatone， 2015）。我的研究将集中在发展智能下肢接口之间的人体组织和机器材料，将适应病人的不断波动的条件，并将减轻深层组织损伤。这可以实现，例如，仅在需要的时候和地方支持残肢。或者，可以创建完全柔软的假体插座和辅助装置，完全消除硬装置到软组织的接口。为了实现这一目标，需要量化和绘制整个步态周期中深层组织内的波动和体积波动。需要进行一项研究，以确定哪种方法能提供最准确的表示。考虑的方法将包括临床测量，如超声（可能是3D和光谱）和弥散张量成像（DTI）和可穿戴测量，如压力和音频。一旦确定了这些元素，有限元（FE）建模就可以用来帮助可视化组织应力和应变的发生，为设计自适应衬垫、新插座或生物界面设备提供一个良好的起点，包括材料、传感器和驱动选择。一旦原型被创造出来，它就需要在实验对象身上进行测试。这可以通过使用Motek Caren系统（Buis, University of Strathclyde）来完成，允许对步态进行准确分析，特别注意步态的对称性。潜在的长期舒适效益需要通过更长的试验期来确定，但初步评估将在实验心理学专家（Kent, UoB）和用户研究专家（Turton， UWE）的指导下进行正式的定性评估。最后，需要解决新设备的美学问题，因为这将最终决定患者使用它的可能性，从而从中受益。

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.