The last few weeks (I know it’s been a little longer than normal since my last post) have seen the start of new challenges, as well as continuing with the old. It seems like a long time coming, but I’ve finally started my PhD. If you asked me ten years ago whether I had thought about becoming a doctoral candidate I would have thought you were joking. Ten years ago I was building up for the interview process for becoming an Army Officer – (then called) the Regular Commissions Board (RCB). At that point, assuming I passed, I had my career mapped out at least until December 2016. I was fortunate enough to be offered a place on the Army’s Undergraduate Army Placement (UGAP) scheme which meant I joined the Army for a full year and this formed the third out of four years of my Bachelor’s degree. In my head I would do this work placement, finish my studies, take a few months out, rejoin the Army and serve for 8 full years. So far, so good! I passed my RCB in August 2005 and moved onto the UGAP just a few weeks later.
Life as an amputee can be difficult – memories of what you used to be able to do are all around and experienced on a daily basis. The current prosthetics available, using microprocessors and motors and bluetooth and carbon fibre, are far better than anything we’ve had before and allow amputees to carry out elements of daily life without hindrance. However, there is a long way to go before they even come close to biological limbs. I’ve picked out four of the technologies currently under development that I find most exciting to, hopefully, give an insight into where the prosthetics industry and amputee treatment are heading.
1. 3D Printing
3D printing is all the rage these days. At the Detroit Motor Show in January, a company called Local Motors unveiled their latest model of fully functioning 3D printed car and was featured on the BBC. The Open Hand Project is a crowd-funded start up project that utilised 3D printing to create a functioning robotic hand for use by arm amputees. Whilst not offering function above and beyond what is already on the market, the technologies involved allow a price tag around 100 times cheaper than some of the more advanced available options. What’s so exciting about 3D printing within prosthetics is the cost factor. Expensive manufacturing processes can be avoided as well as centralised production – designs can be emailed and produced locally, drastically reducing the logistical burden. Spare parts are equally accessible. The open-source nature of the Open Hand Project allows for customisations and modifications depending on user requirements. Components aren’t the only part of prosthetics that can benefit from 3D printing processes. This article from The Manufacturer talks about the University of Southampton’s research into 3D shape measurements and patient specific biomechanical analysis. Whilst this research is intended for rehabilitation analysis, it carries exciting implications for creating a patient specific, medically appropriate 3D printed socket. The Media Lab at MIT are also developing sockets that are not only easier to fabricate, but beneficial to the long term comfort and performance of the prosthetic limb. The VIPr socket uses 3D stump measurement and subsequent biomechanical analysis to create a ‘smart socket’ that allows both stiff and pliable areas of the socket depending on required contact pressure according to the user’s internal stump structure. Engineers on the Innovation and Design Engineering course at the Royal College of Art and the Imperial College, London, have used bone structure algorithms in conjunction with novel materials selection and 3D printing to create the Endura socket, designed with a high strength to weight ratio for maximum comfort and performance for high level athletes.
The flexibility and affordability of manufacture allow for customised designs to be easily produced without shipping, tooling and labour costs. 3D measurement techniques will lead to medically appropriate 3D printed sockets and innovations in 3D carbon fibre printing offer the high strength and durability required for the loads experienced during walking or running. These technologies will drastically reduce the time, cost and labour burden for prosthetic components. These reductions will allow the more amputees access to higher technology components as the cost is reduced and much shorter lead times for the fitting and delivery of sockets which will lead to a marked improvement in quality of life.
The scope of possibilities for 3D printing are already making steps into the medical world and go beyond the manufacture of traditional prosthetic components. Patient Specific Implants (PSIs) are already used in orthopaedic implants such as knee replacements and resurfacing. A CT scan is conducted and the 3D data is sent to the product manufacturer and a CAD code is created to machine a one-off PSI. As can be imagined, this often has large cost implications and a much longer product lead time compared to off-the-shelf products. Advances in printing using techniques grouped under the umbrella term ‘Additive Manufacturing‘ have allowed for the creation of products constructed from metal or ceramic powders. These techniques, used in the medical field, have received a large amount of press when a 3D printed jaw was manufactured from titanium powder and implanted into an 83 year old woman’s face in the Netherlands in 2011.
A very similar technique has recently been used in Israel to recreate the lower half of a patient’s face after he was injured in a rocket attack in Syria last year. The technology goes beyond jaws and bones. Ears, kidneys, blood vessels and skin grafts have all also been 3D printed, conveniently described in this short article from Popular Science. This ability to manufacture ‘replacement’ body parts is going to increase in quality and capacity, expanding the potential for stump lengthening and joint and limb recreation, described in more detail in the Limb Regeneration section.
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