Arnstein T, Buis A
Department of Biomedical Engineering, Faculty of Engineering, University of Strathclyde, Glasgow, Scotland.
Can Prosthet Orthot J. 2024 Jan 17;6(1):42196. doi: 10.33137/cpoj.v6i1.42196. eCollection 2023.
Residual limb discomfort and injury is a common experience for people living with lower limb amputation. Frequently, inadequate load distribution between the prosthetic device and the residual limb is the root cause of this issue. To advance our understanding of prosthetic interface fit, tools are needed to evaluate the mechanical interaction at the prosthetic interface, allowing interface designs to be evaluated and optimised.
Present a methodology report designed to facilitate comprehension of the mechanical interaction between the prosthetic interface and the residual limb. As a pilot study, this methodology is used to compare a hands-on and hands-off interface for a single transtibial prosthesis user using secondary Magnetic Resonance Imaging (MRI) data.
MRI data of the residual limb while wearing a prosthetic interface is segmented into a hard tissue and a skin surface model. These models are exported as stereolithography (STL) files. Two methods are used to analyse the interface designs. Firstly, CloudCompare software is used to compute the nearest vertex on the skin surface for every vertex on the compiled internal bony surface for both interface types. Secondly, CloudCompare software is used to compare registered skin surfaces of the residual limb while wearing the hands-on and hands-off interfaces.
The maximum and minimum nearest distances between the internal bony surface and skin surface were similar between interface types. However, the distribution of nearest distances was different. When comparing the skin surface while wearing both interfaces, where the fit is more compressive can be visualized. For the dataset used in this study, the classic features of a hands-on Patella Tendon Bearing interface and hands-off pressure cast interface could be identified.
The methodology presented in this report may give researchers a further tool to better understand how interface designs affect the soft tissues of the residual limb.
残肢不适与损伤是下肢截肢者的常见经历。通常，假肢装置与残肢之间的负荷分配不当是该问题的根本原因。为了加深我们对假肢界面适配性的理解，需要工具来评估假肢界面处的机械相互作用，以便对界面设计进行评估和优化。
给出一份方法学报告，旨在促进对假肢界面与残肢之间机械相互作用的理解。作为一项试点研究，该方法用于使用二次磁共振成像（MRI）数据，比较单一经胫假肢使用者的亲身体验型和非亲身体验型界面。
佩戴假肢界面时残肢的MRI数据被分割为硬组织和皮肤表面模型。这些模型以立体光刻（STL）文件形式导出。使用两种方法分析界面设计。首先，使用CloudCompare软件为两种界面类型的已编译内部骨表面上的每个顶点计算皮肤表面上最近的顶点。其次，使用CloudCompare软件比较佩戴亲身体验型和非亲身体验型界面时残肢的配准皮肤表面。
两种界面类型之间，内部骨表面与皮肤表面之间的最大和最小最近距离相似。然而，最近距离的分布不同。比较佩戴两种界面时的皮肤表面，可以直观显示出适配更具压迫性的位置。对于本研究中使用的数据集，可以识别出亲身体验型髌腱承重界面和非亲身体验型压力铸造界面的典型特征。
本报告中提出的方法可能为研究人员提供进一步的工具，以更好地理解界面设计如何影响残肢的软组织。
