CUSTOMISATION OF COSMETIC COVERS FOR ARTIFICIAL LIMBS

该提案将数字制造和异质泡沫的学术专长(斯特拉斯克莱德大学设计、制造和工程管理系)与假肢从业者(斯特拉斯克莱德大学、国家假肢和矫形学中心)和非学术合作伙伴、制造商(布拉奇福德有限公司)结合在一起。和服务用户(PACE康复，一家中小企业)，研究彻底改变假肢功能和外观的可行性。目前，软质聚氨酯泡沫塑料是一种广泛使用的肢体假体部件。在一个非常劳动密集型的过程中，宇宙可能会从板材加工成半成品，然后进一步成型以满足患者的要求。为了增强假体的美观外观，通常会添加普通的覆盖长袜。截肢者用双重功能美容覆盖他们的金属矫形肢体(即假肢、手臂等)：它保护昂贵的设备，从理论上讲，它为患者的矫形假体提供了更好的美学外观。现实是，化妆套性能不佳，吸尘，不防水或防火，阻碍关节的正常功能(S)，视觉整理差，阻碍患者的心理恢复和接受他们的新情况和外观。尽管广泛使用，泡沫美容既不像人体四肢变形，也不能经受反复弯曲，它的外观与人类皮肤相去甚远。这些问题的根源在于所用泡沫的标准化性质；由于整个材料的孔径均匀且均匀，因此硬度也将保持不变，因此它将以一种不自然的方式弯曲。最终，高应力区域将失效，泡沫将撕裂关节(尤其是膝盖)。泡沫塑料的机械性能由其泡孔结构决定；因此，与大开口浇注相比，具有较厚壁厚的小泡孔可以产生更坚固、更坚硬的材料。传统的制造方法是用均匀的泡沫块制造宇宙，从而产生具有统一机械性能的物体。然而，众所周知，细胞结构的变化可以产生令人印象深刻的力量和灵活性的组合。到目前为止，还不存在能够动态改变发泡材料的泡孔结构的大规模生产的制造方法。因此，美容中的特征的受控变化以适应患者的运动和需求是不可用的。这项建议旨在实现功能分级泡沫的大规模定制，以便它们可以安装到矫形肢体上，并复制现有(健康)肢体的运动。利用最近报道的该领域以前从未使用过的先进制造技术(例如，泡沫材料行为的计算建模和模拟、快速成型技术、超声波辐射等)，以及材料性能扫描和测量方面的尖端技术，我们的目标是为最终用户(包括专业义肢医生和患者)提供一种影响骨科应用的泡沫宇宙的形状、外观、功能和行为的方法。该提案设想了一个为期两年的工作计划，在此期间，商业合作伙伴将帮助患者进行满意度访谈，将直接输入到要求规范中，并帮助评估结果。我们对该项目成果的意图是为我们的合作伙伴在生产过程中应用和实施成果铺平道路，使他们能够推进工作，并利用该项目的成果将为相关行业、康复服务、护理人员(即矫形外科医生)、国民健康服务，以及最重要的是患者带来的好处。

This proposal combines academic expertise in digital manufacturing and heterogeneous foams (University of Strathclyde, Department of Design, Manufacture and Engineering Management) with prosthetics practitioners (University of Strathclyde, National Centre for Prosthetics and Orthotics) and non-academic partners, manufacturers (Blatchford Ltd.) and service users (PACE Rehabilitation, an SME), to investigate the feasibility of revolutionising the functionality and appearance of prosthetic cosmoses. Currently, flexible polyurethane foam cosmoses are a widely used component of prostheses for limbs. In a very labour intensive process, cosmoses may be machined from slab stock to a semi finished form and then shaped further to match patient requirements. An ordinary covering stocking is often added to enhance the cosmetic appearance of the prosthesis. Amputees cover their metal orthopaedic limb (i.e. artificial leg, arm, etc) with a two-fold function cosmesis: it protects the expensive equipment and, in theory, it provides a better aesthetic appearance to the patient's orthopaedic prosthesis. The reality is that cosmetic covers underperform the artificial limb, attract dirt, are non-water proof or fire resistant, impede the normal functioning of joint(s) and have a poor visual finishing which hinders the patient's psychological recovery and acceptance of their new condition and appearance.Although widely used, the foam cosmesis neither deforms like human limbs nor withstands repeated flexure, and its appearance is far from resembling human skin. These problems have their root in the standardized nature of the foam used; with a homogeneous and uniform pore size throughout the material, the stiffness will also be constant and consequently it will bend in an 'unnatural' way. Ultimately the highly stressed areas will fail, and the foam will tear at the joints (especially on the knee). The mechanical properties of foams are determined by their cellular structure; so small cells with thicker walls create stronger, stiffer materials than large open pours. Traditional manufacturing methods have fabricated cosmoses from blocks of homogeneous foam resulting in objects that have uniform mechanical properties. However it is also well known that variation in cellular structure can produce impressive combinations of strength and flexibility. To date, no manufacturing process for mass production has existed capable of dynamically varying the cellular structure of foamed material. Consequently, a controlled variation of features in the cosmesis to suit patient's movements and needs is not available. This proposal seeks to enable the mass customization of functionally graded foams, so they can be fitted to orthopaedic limbs and replicate the movement of the existing (healthy) limb. Using recently reported advanced manufacturing techniques never used before in this field, (e.g. computational modelling and simulation of foamed materials' behaviour, rapid prototyping technologies, ultrasonic irradiation, etc), as well as cutting-edge technology in scanning and measurement of materials properties, we aim to provide end-users (both practitioner prosthetists and patients) with a method of influencing shape, appearance, function and behaviour of foam cosmoses for orthopaedic applications.This proposal envisages a 2 year work program during which the commercial partners will help with patient satisfaction interviews, will input directly into the specification of requirements, and assist with the assessment of results. Our intention with the outcomes of this project is to pave the way for our partners to apply the results and implement them in the production process, allowing them to take the work forward and exploit the benefits that the project's output will provide to the relevant industry, rehabilitation services, carers (i.e. orthotists), the National Health Service and, most importantly, the patient.