3D interactive environment for the design of medical devices

Abstract

The effectiveness of custom-made prostheses or orthoses heavily depends on the experience and skills of the personnel involved in their production. For complex devices, such as lower limb prosthesis, a conventional manual approach affects the process at the point that the result is frequently not acceptable at the first trial. The paper presents a computer-aided environment, named socket modelling assistant 2 (i.e., SMA 2 ), to interactively design the socket of lower limb prosthesis by implementing a set of design rules extrapolated from the traditional development process. The new computer-aided environment has been implemented embracing a low-cost philosophy and using open source libraries to provide a solution affordable also by small orthopaedic laboratories. The system permits to modify and interact with the 3D model of residual limb to create the socket geometric model ready to be manufactured by means of additive manufacturing. SMA 2 embeds medical knowledge related to the device functioning, the conventional process and the way orthopaedic technicians work so that it can be much more reliable and repeatable compared to the conventional process, but still enough similar to it to be accepted by the involved personnel. In the paper, the new 3D design procedure is described in detail, from the acquisition of patient's data to preliminary and customized modelling, and new geometric tools to perform context-related operations are shown. A case study is used to clarify the way the system works and to provide an example of the outcome.

Pioneering low-cost 3D-printed transtibial prosthetics to serve a rural population in Sierra Leone – an observational cohort study

“…However, previous research showed that the quality of these prosthetic sockets was at the lower end of the acceptance level [16À18,46]. Because the positive mold is adjusted manually in the process of PTB sockets, the socket shape is highly dependent on the experience and skills of the prosthetist, with the consequence that quality assurance cannot be given [15][16][17][18].…”

“…However, there are no standards for testing the prosthetic socket, because this part is custom made. Nevertheless, multiple studies have used these guidelines for testing FDM-printed prosthetic sockets, making this testing method a logical choice to test the prothesis [18,24,53,54]. In recent years, potentially suitable FDM print materials became available with increased layer-on-layer adhesion.…”

Usability of free software used for visualization and measurement of digital orthodontic models

“…This scan generates a digital file that needs specific software for visualization and that, for the most part, can be exported in STL (Standard Triangle Language) format. However, these programs generate significant costs for orthodontists (Camardella and Vilella 2015;Burhardt et al 2016;Colombo et al 2018). On the other hand, there are free software available on the Internet that allow the visualization of digital orthodontic models since they are provided in STL format.…”

Analysis of Pressure Distribution in Transfemoral Prosthetic Socket for Prefabrication Evaluation via the Finite Element Method

“…Portnoy et al [8] also reported that using a subject-specific real-time analysis of the internal tissue loads in the residuum is a practical tool for evaluating the internal stress inside the residuum in a clinical setting or outdoors. From another aspect, Colombo et al [9] managed to develop a computer-aided environment, namely, a socket-modeling assistant (SMA), combining knowledge from prostheses and a 3D model simulation to create a prosthesis socket. Such research has resulted in the creation of a prosthesis socket using the additive manufacturing (AM) technique, although a compatibility analysis of the created socket has yet to be carried out.…”