Please introduce yourself. What is your background?
My name is Thijs Smit. Growing up in Rotterdam, The Netherlands, sailing was (and still is) a big passion of mine. I studied mechanical engineering at the Delft University of Technology. During my masters I was specializing in computational mechanics and structural optimization and got in touch with programming finite element software and topology optimization. I had the opportunity to join the Bertoldi group for several months during my graduation project which lighted my enthusiasm for research. After graduation I got an opportunity to work in the Dutch high-tech industry where I worked for about 2 years. At that point I decided to change focus and start a PhD in Biomechanics at the ETH Zurich. This turned out to be a good decision as I could now apply my skills in computational engineering and optimization on biomechanical problems and try to improve orthopaedic treatments and ultimately patient lives.
You have received the SSBE award. Please briefly describe the project.
My PhD project was about optimizing the design of spinal fusion implants using topology optimization. I could use my skills from the computational mechanics field and apply it on a biomechanical problem: mechanical failure of bone adjacent to the orthopaedic implant. I saw that patient-specific implants have many advantages but the patient-specific implants as we know them today are only patient-specific in terms of geometry. However, CT scans carry structural information about the quality of the patient’s bone as well. I developed a topology optimization algorithm that can use this patient-specific structural information to improve the implant design. This led to so called anatomically and mechanically conforming patient-specific implants. I applied and tested the algorithm on spinal fusion cages with good results. The optimized cages promise to reduce the risk of fracture (subsidence) of adjacent bone structures significantly.
In-silico medical device testing study compares the risk of subsidence of three implants using a patient-specific computer model. This visualizes the influence of the implant on the adjacent bone structures under loading. The coloured element in the bone domains show overloaded elements that are at risk of fracturing. (figure from: Smit T, Aage N, Haschtmann D, Ferguson SJ and Helgason B (2024) In silico medical device testing of anatomically and mechanically conforming patient-specific spinal fusion cages designed by full-scale topology optimisation. Front. Bioeng. Biotechnol. 12:1347961)
What does the SSBE award mean to you?
The SSBE award recognises the importance of our research. Also, it gave me another opportunity to present my research and get feedback. And finally, it is an honour to receive the award.
Is this project still active? What are the goals?
The project is very active because of our activities to commercialize patient-specific optimized implants. These activities are partly related to business development. For this part we recently got support from Venture Kick and is mainly focused on getting feedback from surgeons and on investigating the reimbursement situation in the potential markets. The other part, the technical development, is focused on all the technical challenges that come from bringing an orthopaedic implant to the market.
Did the award have an impact on your career?
I think the award is a quality stamp of the PhD and the invention that was the product of it. So, it will help gaining credibility.
What kind of work are you currently doing? How is it related to your PhD studies?
As discussed above, I am working on translating the invention that was the result of the PhD project. Furthermore, I have my own company, where I am offering engineering services to the mechanical engineering and medical device industry.
What is special about your current work?
I choose to follow the entrepreneurial path and that comes with its own set of challenges. I enjoy it and I am learning a lot. Also, this gives me the flexibility to work on the development of the patient-specific optimized implant project when needed.
Where do you see yourself in five years?
In 5 years, I would like to have made big steps in the development of the implant project. For example, have our spinal fusion implant approved for in-human implantation.
Is there something that you would like to convey to the SSBE members?
Thank you to the SSBE members for providing the opportunity to students and researchers to present their work. I think that the people attending the SSBE conference were very friendly and motivating. Furthermore, the interdisciplinary nature of the SSBE is, I think, of added value. It is great to have such a Biomedical engineering society in Switzerland!