The following works were performed during the Fellowship:
(1) Two musculoskeletal models were developed and adopted to simulate three activities: one model was developed based on Rajagopal model, which was used to simulate walking and running activities; the other one was based on Delp model, which was used to simulate an inversion-inducing dropping activity. A python code was developed to run the two musculoskeletal models and simulation of the three activities automatically;
(2) The design variables for the AFO were determined. Based on the variables, a representation of AFO was created in the musculoskeletal model. An advanced gradient descent (GD) optimization algorithm was developed and integrated with the python code developed in Objective (1). The GD algorithm was then adopted to optimize the design variables of AFO;
(3) Collaborating with a postdoctoral researcher and a PhD student, the proposed AFO was 3D printed and assembled;
(4) The musculoskeletal model was used to test the perform of the AFO in terms of protecting the ankle from injury in high-risk scenarios through inversion-inducing dropping activity simulation.
The main results:
(1) The project developed a simulation-based medical device development platform, for the first time integrating an advanced musculoskeletal simulation model, an advanced GD optimization method and a state-of-the-art 3D printing technology, with aim of developing a novel AFO. This platform will provide a leap forward in the design, optimization, development and manufacturing of cost-effective, highly personalised and functional tailored orthoses.
(2) The project designed and developed a novel AFO that could feature unprecedented combinations of properties and functionality by controlling geometry, material composition and structure through 3D printing. Unlike previous soft or semi-rigid AFOs, the novel AFO demonstrated a tailored nonlinearity, which exhibits very low stiffness at natural movements of the ankle but significantly increased stiffness when the ankle is over inversed or extended. In this way the AFO will allow natural movements but impede excessive movements that lead to (re)injury.
Exploitation:
The simulation platform developed in the project will provide a research pipeline of how to develop a musculoskeletal model and apply the model to simulate the function of lower limb orthoses and prosthetics, which will be beneficial to the biomedical and biomechanical simulation communities, as well as orthoses and prosthetics industries;
The integration of a musculoskeletal simulation model and 3D printing technology will provide a state-of-the-art technology to produce cost-effective, highly personalized and function tailored orthoses and prosthetics, which will benefit the orthoses and prosthetic manufacturers and industries.
Dissemination:
(1) The results of the project will published in a top journal – Nature Biomedical Engineering;
(2) The developed simulation-based design, optimization and development platform for the medical device was presented in the University of Leeds and DePuy company in the UK;
(3) The developed musculoskeletal modelling and simulation were presented to the researchers and publics at “IfM Festival of Teaching, Research and Practice” in the University of Cambridge.
