Our soft tissues swell and shrink throughout the day, so a wearable that fits in the morning may not do so in the afternoon. A new adaptive lining for the sockets of prosthetic limbs was designed with this important fact very much in mind.
Known as "Roliner," the material is being developed by British biomedical startup Unhindr, which is in turn an Imperial College London spinoff company. Here's how the technology works…
Utilized to pad the inside of the sockets on third-party artificial arms or legs, Roliner is composed mainly of soft silicone rubber with small air channels running through it. A compact onboard battery-powered pump can inflate or deflate those channels on demand, changing the shape, volume and stiffness of the padding.
When the augmented prosthesis is first being used, the wearer uses an app to manually activate the pump throughout the day, tightening, loosening or shifting the fit in real time as needed. This may be required in response to soft tissue changes brought about by variables such as activity level, time of day, or ambient temperature.
By the time this "training period" is over, an AI-based algorithm has learned how the fit tends to be altered over the course of a typical day. This newfound knowledge allows the Roliner channels to be inflated or deflated automatically, as a preemptive means of avoiding discomfort, lowered performance, or even the formation of pressure sores.
Of course, the fit can still also be manually adjusted as needed.
It is hoped that the Roliner system will be available for use in the UK by the end of this year, perhaps joining a similar system being developed at the Korea Institute of Machinery and Materials. The technology could also find use in applications other than prosthetics, such as wearable exoskeletons, downhill ski boots, or even spacesuits.
"Ultimately, no matter how sophisticated the [prosthetic] limb itself is, if it cannot connect closely and comfortably with the human body, it becomes unwearable," says Imperial College London's Dr. Firat Guder. "Up until now, researchers have tried and failed to solve this problem by trying to improve the limbs and sockets themselves. But we took a different approach by developing a dynamically adaptive interface for the liners used between the body and the rigid prosthetic socket."
A paper on the research was recently published in the journal Nature Communications.
Sources: Imperial College London, Unhindr
