Stella Gabbiadini

Design Procedure and Rules to Configure Lower Limb Prosthesis

Modular lower limb prosthesis is composed by custom-fit parts, such as the socket containing the residual limb, and standard components available on market, such as knee or foot. For both custom and standard parts the support offered by existing design tools is not efficient or integrated enough and, as a result, most prosthetists do not use computer-aided tools and still rely only on their personal expertise. This paper presents an approach to design and configure complete lower limb prosthesis for transfemoral and transtibial amputees, using patient’s digital data (e.g., residual limb model acquired by MRI) and specification sheets of components. The ultimate goal is to realise a virtual laboratory where the technicians can design lower limb prosthesis guided step by step by the system. We have identified key patient’s characteristics guiding the prosthetist during the four main steps of the production process: acquiring patient’s data, socket modelling, standard components selection and prosthesis assembly and check. The developed innovative framework integrates different tools to guide the technicians during each design task providing specific knowledge and rules. Thus, it allows a quicker and easier definition of the virtual prosthesis, on which virtual test could be performed (e.g., pressure distribution on residual limb, gait evaluation) in order to be able to realize the definitive prosthesis at the first attempt. The results have been evaluated and validated with the technical staff of a certified orthopaedic laboratory.Copyright

Virtual Configuration of Lower Limb Prosthesis

This paper presents a new design framework to configure lower limb prostheses, both transfemoral and transtibial, where the key elements are the patient digital avatar and the domain knowledge. The technician is supported during the design process by the knowledge acquired from analysis of the traditional process and represented in the framework. The last one integrates virtual prototyping tools and knowledge management techniques. A specific software tool, named Socket Modelling Assistant, has been developed to design the socket, the custom-fit component of the prosthesis. A commercial CAD system is used to model the standard components (e.g., knee, foot and tubes) and to create the final assembly. Patient avatar and his/her data (e.g., anthropometric and physiological parameters) are the backbone of the whole product design process. They guide both the selection of standard components and the modelling of the socket digital model.Copyright

Knowledge Management and Customised 3D Modelling to Improve Prosthesis Design

This paper presents a new approach to design lower limb prosthesis focusing the attention on geometrical model issues. The new design approach has been developed within national and international research projects and, at present, “ad hoc” tools to carry out specific tasks are under development. Within this context, an important role is played by product and process knowledge and by specific CAD tools to design the most critical component, the socket. The paper discusses acquisition and formalisation of the knowledge related to the prosthesis design, with particular attention to the socket, and presents main features of a CAD tool specifically intended for this highly customised component.Copyright

Socket modelling assistant for prosthesis design

In this paper, we propose a knowledge-based approach to design lower limb prostheses; in particular, we focus on the 3D modelling of the socket, the most critical component. First, the architecture of a dedicated design framework is described, detailing features of the main design steps. Then, the paper discusses the acquisition and formalisation of the knowledge related both to the prosthesis manufacturing process and to the considered component. Finally, we present the computer-aided module, named socket modelling assistant-SMA, we specifically developed to design the socket. It is a virtual laboratory where the socket virtual prototype is generated directly on the digital model of patient’s residual limb. It guides and supports the designer during each step in an automatic and/or semi-automatic way applying design rules and procedures. The modelling steps and available interactive tools that emulate orthopaedic technician’s operations are described. Results of the experimentation phase are described. A...