A team of researchers at the University of Southampton and Ecole Polytechnique Fédérale De Lausanne (EPFL), a research institute, has developed technology that enables amputees to feel wetness through a prosthesis, via a sensor that fits on a prosthetic hand and is connected to a stimulator that touches the wearer’s residual limb.
The invention could improve the dexterity of prosthetic hands and enhance the sensory experience and acceptance of prosthetic limbs for their users.
Davide Filingeri, PhD, associate professor in thermal physiology and director of ThermoSenseLab at the University of Southampton, is behind the wetness-sensing aspect of the work. “A lot of work in this field has concentrated on techniques that help restore motor control,” he said. “But motor control is very difficult without sensation. In the last ten years, the field of work has tried to restore that sensory feedback.”
Working with a clinical partner in Italy, researchers at EPFL, led by Solaiman Shokur, PhD, Maria Ploumitsakou, PhD, and Jonathan Muheim, developed a sensor that detects temperature through a prosthetic device.
“Through previous work we’ve done at ThermoSenseLab, we know that the way we sense wetness is very much linked to how we sense temperature; we have a specific set of thermal cues that sense wetness,” Filingeri said.
The developments could have significant physical and psychological benefits for prosthetics wearers. “We think this is likely to have implications for amputees’ manual dexterity through the prosthetic limb,” Filingeri said. “For example, the level of wetness influences how hard you grab something, if a glass is wet it might be slippery. It also expands the range of natural sensations amputees can experience and it enhances the embodiment and acceptance of the prosthetic limb, amputees can feel more like the prosthetic belongs to their body.”
Ploumitsakou, first author on the study, added, “Understanding the human wetness perception with the aim of restoring it in prosthetics users has been a fascinating challenge. Wetness perception is a step towards enriching the way that amputee patients feel and interact with the world.”
The research team is now seeking to prove these implications of their work through determining whether heat and wetness sensing does indeed increase the sense of body ownership for prosthetics wearers.
Editor’s note: This story was adapted from materials provided by the University of Southampton.
