Implementation of advanced design and additive manufacturing techniques for the development of medically relevant devices

Abstract

The application of Computer-aided Design (CAD), Engineering (CAE), and Manufacturing (CAM) has brought many benefits to a wide range of sectors. For the healthcare sector, it has enabled the development of complex and enhanced devices which offers promising solutions to current problems. The main applications can be seen in the planning, training, and designing stages. By conducting the design and validation stages in the digital world, prediction of the device manufacturing and performance can be accurately obtained, thus producing the optimized version with engineered properties. Furthermore, novel behavior, geometries, and materials can be achieved, which was not possible by conventional means. In this work, the application of the Design for Additive Manufacturing (DfAM) technique is highlighted for surgical training and planning, as well as load-bearing implant design. The development of smart laparoscopic surgery training devices is presented. The inclusion of force and motion sensors into custom-made 3D-printed parts fitted to common laparoscopic surgical tools enables the objective training and classification of users based on their performance quality. Furthermore, the use of force sensors in varying stiffness sensors is presented as a base for the application of biomimetic models which offer digital information about their elasticity, which could be translated to tissue properties. The second study case presents the different approached for the development of stiffness-matched devices. Novel more-elastic materials, engineered porosity, and planning of implant location can be employed to tailor the mechanical behavior of load-bearing devices. We present the effect of unit cell rotation for tailoring the mechanical properties of strut-based porosity. Also, the application of engineering porosity in addition to Nickel-Titanium alloys is studied as a promising case for stress-shielding effect reduction. Finally, it assessed the effect of changing the location of personalized fixation on the mechanical behavior of bone reconstruction before and after healing. Results show that these three factors play a crucial role in reducing the stress concentration on the implant, hence, enlarging its life-span.