Artificial limbs work better now than they ever did before, but they still don't quite function in the same way as a natural limb. They're usually attached to stumps by means of a socket, but since no stump is exactly the same shape and size, it can be a challenge to create a socket that fits just right.
Thousands of amputees are familiar with pain, discomfort, blisters, sores and even scarring. All this can be blamed on sockets that don't fit right, resulting in pressure and rubbing. What makes this problem really tough to solve is the fact that even a single individual's stump can change. This is particularly true for growing children and adolescents, but a person's stump can even change from one day to the next, influenced by environmental and health factors.
Is it even possible to create an artificial-limb socket that fits just right, then? Can amputees be free of the pain and discomfort that comes with ill-fitting sockets, something that may even prevent them from wearing the artificial limb they depend on?
Dr Liudi Jiang, from the University of Southampton, came up with an innovative solution.
She said: "Socket fit is the single biggest factor determining whether prosthesis will be successful for a patient. If we had a simple way to accurately measure the load at the socket-stump interface and determine the best possible fit for that limb, it would completely transform the socket fit experience for amputees."
The Artificial Limb Of The Future
Dr Jiang, leading a multidisciplinary team at the University of Southampton, says that the answer comes in the form of a "second skin" — a sensor that can detect downward pressure and rubbing. Such a sensor could be immensely helpful, because many amputees have decreased sensation at the amputation site. Still, the pressure builds up over time, and rubbing leads to blisters and injuries. Despite the decreased ability to sense these problems immediately, they will lead to discomfort and pain in the end.
Amputees wear synthetic liners on their stumps to provide a certain degree of cushioning, just like one would wear socks (at least partially) to make shoes fit more comfortably. A small band with a sensor could give feedback regarding pressure and rubbing. This sensor could warn the amputee and their healthcare providers that the artificial limb's socket needs a better fit. This information could mean that the wearer's next socket would be much more comfortable.
A smart socket that adjusts to the needs of the wearer automatically, on an ongoing basis? That would certainly transform the lives of many amputees completely, and the good news doesn't stop there either. The BBC reports that the new technology could be available to British residents using the NHS very soon, within three years.
The sensor has more potential applications as well. Wheelchair users, people on extended bed rest, and diabetics using insoles could all benefit from this technology.