New prosthetic hand design will allow heat sensation

In an article on ScienceNews.org, Simon Makin writes about how researchers in Italy and Switzerland have made strides in prosthetic technology by developing a device called “MiniTouch” that allows individuals with amputations to sense temperature with a prosthetic hand. In a recent study, the device was attached to the prosthetic hand of a 57-year-old man named Fabrizio, who has an above-the-wrist amputation. During tests, Fabrizio demonstrated an impressive ability to accurately identify cold, cool, and hot liquids, distinguish between plastic, glass, and copper, and sort steel blocks by temperature with around 75 percent accuracy.

The device, which currently employs a single sensor at the end of the index finger, enhances the user’s ability to perceive and interact with their environment. It not only allows for temperature detection but also improves the individual’s accuracy in discerning whether they are touching an artificial or human arm. Fabrizio’s accuracy increased from 60 percent with the device turned off to 80 percent with it on, showcasing the potential of MiniTouch in providing a more natural sensory experience for prosthetic users.

This development is part of ongoing efforts to restore a sense of touch to prosthetic limbs, an area that has seen significant progress over the past decade. While advancements have been made in tactile feedback, the ability to detect temperature has lagged behind. The researchers behind MiniTouch addressed this gap by mapping Fabrizio’s phantom temperature sensations to corresponding spots on his arm, allowing the prosthetic hand to relay temperature signals through a controller unit.

While the current device utilizes a single sensor, the research team plans to expand its capabilities by incorporating additional sensor-stimulator pairs to create more temperature-sensitive locations on the prosthetic hand. Additionally, they aim to develop a prosthesis that combines both temperature and touch sensation, bringing the artificial limb closer to replicating the capabilities of a biological one.

Despite these promising developments, challenges remain, including the need for further testing in larger participant groups and real-world settings to ensure the device’s effectiveness under various conditions. The researchers acknowledge the importance of addressing potential issues related to high air temperatures or humidity. Once these challenges are overcome, the technology could significantly improve the functionality and acceptance of prosthetic limbs.

Fabrizio, the participant in the study, expressed enthusiasm about the potential applications of the technology in his daily life, particularly in activities like cooking. As MiniTouch continues to evolve, it holds the promise of providing prosthetic users with a more nuanced and comprehensive sensory experience, enhancing their ability to engage with the world around them.