Last year, I had a discussion with a client about his prosthesis. He has a transfemoral amputation. In his opinion, the prosthesis we provided did not represent state-of-the-art technology. “This is a rather crude replacement; it does not work intuitively,” he said. He added, “I recently saw a video of a robot doing a backflip on the Internet. If this is possible, my prosthesis can’t be state of the art.” In fact, he got a modern prosthesis with an ischial containment socket, a latest-generation microprocessor-controlled knee, and a carbon-fiber foot.
This conversation made me think a lot. In my last contribution, I talked about the drastic changes in the P&O field and the advancement of new technologies. Sure, there has been a lot of progress in our domain, but has this been in accordance with the pace of developments in other technologies? First and foremost, one could refer to information technologies, including smartphones, which are progressing at a drastically higher pace in comparison to P&O. The rapid advances in electronics and the discussion with the young client were somehow discouraging for me, as I feel electronics companies have the knowledge and manpower available to design such modern devices. I do wish P&O manufacturers and research entities would have the same resources available. However, this view may be too pessimistic, and I do take comfort from the fact that many components that are now widespread in consumer electronics, for example, accelerometers and gyroscopes, are now more easily available than ever before. So, in the long run, new technologies will find their way to P&O. This is already happening as the newer generations of microprocessor-controlled prosthetic and orthotic devices incorporate such components to improve function. Further, one has to remember that our requirements differ from those of consumer electronics. In P&O, reliability and durability of devices and the robustness of algorithms play a superior role, as a person with a lower-limb amputation will not accept that his or her prosthesis will randomly shut down and fail once a week. On the other hand, such a flaw might be acceptable in a smartphone that, except for this weakness, fulfills all your requirements.
Absolutely, we want to be innovative and use state-of-the-art electronics in our devices, but we also need to have different requirements in mind. We need to sustain and replace function in a person with a disability. The computing and sensing performance of devices will not be the determining factors for function in an assistive device. So first and foremost, we need algorithms that will interpret the data of modern sensors to achieve this task. Constant research is needed to utilize new technologies, and the Journal of Prosthetics and Orthotics is one of the platforms to make such research available to the public.
In the end, there might be some similarities to your smartphone, as it is only as powerful as the apps or algorithms that run on it.
Daniel W. W. Heitzmann, Dipl. Ing. (FH)
JPO Editorial Board Member
Heidelberg University Hospital
Department of Orthopaedics and Trauma Surgery
Motion Analysis Lab
Prosthetics and Orthotics Department
email: [email protected]