'I’ve always been a sci-fi nerd, and the concept of highly advanced prosthetic limbs played a large role in the media I consumed growing up. Being able to replace a limb with a mechanical contraption is an interesting and exciting prospect. And although we’re far from reaching that milestone, I’d like to contribute to us getting closer to that goal. Not only this, but in my mind prosthesis research is the perfect crossover between engineering and medicine. These are the two occupation areas that interest me most.'

An afterthought in prosthetics?

Sam is working on a hybrid prosthesis concept that combines the traditional body-powered terminal device with a wrist unit controlled through the activation of a user’s muscles. Many researchers are focusing efforts on anthropomorphic hands that try to replicate the natural human hand's 27 degrees of freedom. But other fundamental parts of the arm's anatomy are being neglected - namely, the wrist.

'The wrist plays an essential part in object manipulation and the performance of many daily tasks. Yet, in upper-limb prosthetic research, it's typically relegated to an afterthought. The same problem exists in industry, where there are few active rotational wrist units, and more or less no flexion/extension wrist units. This significantly reduces the capacity to perform complex object manipulation tasks for people with an upper limb absence. The wrist unit I'm developing will perform both flexion/extension and pronation/supination within a compact space. It will also be compatible with both myoelectric and body-powered prostheses.

'When I finish my PhD, I aim to have a complete prototype that performs better than any controls we put it against. Not only do I hope it performs better, but also for participants to enjoy using it more than the control as well. Only with both factors can we make a convincing case for this concept to be more widely adopted by the upper-limb amputee community.

'I hope the results will provoke a more adventurous approach to prosthetics research where people aren't afraid to integrate different design principles. Namely, combining both body-powered and myoelectric prosthetic classes to work together. Also, I simply hope that it makes the lives of amputees who use the device better, even in a small way.'

Results in action

During their degree, Sam has worked with quadruple amputee, Alex Lewis and the FLOAT Foundation (for the love of assistive technology). Alex's 'Pig to Pig' land and sea challenge in 2023 included rowing from Falmouth to Dover. The opportunity has had a lasting effect on Sam and shaped their PhD experience.

'We designed a set of rowing arms for Alex to row the 350 miles along the English coast. The arms we designed weren't particularly remarkable. But what was remarkable was this first taste of designing a prosthesis and having it used in such an incredible way. We trialled it, we made notes, and we modified it to better fit Alex and his needs. This is exactly the kind of process I joined the PhD to be a part of.

'Alex has been a constant source of motivation since my last year of undergraduate studies. He regularly tours the UK to take part in research studies that aid protheses development. As such I’ve had the pleasure of meeting him many times. Every time, he has offered a whole new perspective on the current project and informed its development in a positive way that would be impossible without his unique insight.

'Both Alex and my supervisory team have been my key teachers and inspirations during my PhD so far. I’m very lucky to have found myself with a supervisory team that covers a broad range of expertise and people who are all very eager to help out wherever they can.'

Discovery is the motive

Before joining the University of Bath for a PhD, Sam studied Design Engineering at Imperial College London. Deciding whether to continue with higher education or go into employment can be a difficult decision. For Sam, the motivation to make a change in the future of prosthetics made the choice more straightforward.

'While industry may pay more, it doesn’t offer the potential to explore and experiment in the way that academia does. I enjoy the scientific process, and I want to contribute even in some small way to the shared knowledge that pushes my field further. Not only this, but prosthetics is a niche yet established field where the old guard of prosthesis care fails to innovate and listen to what those with limb-absence want. Also, and this is solely my opinion, the cost of these products that many people rely on is exploitative. I want to push knowledge and innovate in an area where discovery is the motive, not the profit margin.

'One of the most satisfying parts of my PhD is interacting with the people I'm trying to help. With a project as human-focused as mine, you have to engage with and listen to people. Talking with amputees about how significantly their lives improved following an amputation, usually due to underlying health conditions, and seeing the new lease of life that the right prosthesis can give is very motivating.

'I'm still undecided about what I want to do after my PhD. If I identify an area of prosthetics I'd like to investigate further, I'll continue research within academia. If not, I'd be very interested in joining one of the newer prosthetics companies like Open Bionics or Koaala. They are really tackling some of the most fundamental problems within the industry.'