A total system approach to optimising the skin-socket interface

下肢假肢已经被证明是一种非常成功的干预手段，为先天性肢体缺陷或截肢的人提供了行动能力。为了达到足够的功能，下肢义肢需要残肢皮肤具有极强的弹性。在使用过程中，所有载荷都通过插座-蒙皮界面传递，这意味着蒙皮通过剪切应力承受显著的载荷。这些增加的对皮肤的需求可能导致各种各样的伤害。事实上，超过40%的截肢者患有残肢皮肤病，多达22%的使用者在第一年就停止使用假肢。开创性的生物工程研究表明，由界面压力和剪切力引起的组织变形引起的皮肤损伤由两个主要机制引起：(1)直接细胞变形，即组织内部产生的机械条件导致细胞膜完整性丧失b[3]；(2)长期组织变形，导致血液和淋巴管闭塞，分别导致携带氧气的血细胞运输受损，废物和毒素积累[4,5]。皮肤-插座界面形成了一个生物力学系统，在这个系统中，相互作用强烈地依赖于系统的所有组成部分，即：插座材料及其表面光光度，通过界面传递的载荷，皮肤的特征和插座中当地的小气候。大多数关于残肢-窝接口的研究，包括本项目中PI和co - i的研究，通常只关注系统的一个组成部分（Masen：假体-皮肤接口；Higgins：体外皮肤反应；Worsley：体内皮肤反应）。在这个研究项目中，我们建议使用一种系统方法来优化皮肤-插座接口，这种方法不仅仅关注接口的一个组件，而是考虑所有相关组件。这种结合的方法将告诉我们参数之间的关键依赖关系，并使我们能够提供优化这个复杂界面设计所需的知识。

Lower limb prosthetics have proven to be an extremely successful intervention, providing mobility to people with congenital limb deficiencies or who have suffered amputation. To achieve adequate function, a lower limb prosthetic requires extreme resilience from the skin on the limb stump. During use, all loads are transferred through the socket-skin interface, meaning the skin is subjected to significant loading through shear stresses. These increased demands on the skin may result in a variety of injuries. Indeed, over 40% of amputees suffer from dermatoses on the stump [1] and up to 22% of users discontinue the use of their prosthetic in the first year [2]. Seminal Bioengineering research has shown that skin damage from tissue deformations resulting from interface pressures and shear forces is initiated by two primary mechanisms: (i)direct cell deformation where the internal mechanical conditions generated within the tissues lead to a loss of cell membrane integrity [3], and (ii) prolonged tissue deformation which results in occlusion of blood and lymphatic vessels leading to compromised transport of oxygen-carrying blood cells and accumulation of waste products and toxins, respectively [4, 5]. The skin-socket interface forms a biomechanical system in which the interaction strongly depends on all components of the system namely: the socket material and its surface finish, the loads that are transmitted through the interface, the characteristics of the skin and the local micro-climate in the socket. Most research into the stump-socket interface, including that of the PI and Co-Is in this project, typically focuses only on one component of the system (Masen: prosthesis-skin interface; Higgins: skin response in vitro; Worsley: skin response in-vivo). In this research project, we propose to optimise the skin-socket interface using a system approach that does not simply focus on only one of the components of the interface, but instead considers all relevant components. This combined approach will inform us of the critical dependencies between parameters and enable us to deliver the knowledge required to optimise design of this complex interface.