Research in prosthetic hands has seen some pretty major advances in recent years. These advances are evidenced by two new studies that demonstrate developments in technology that allow the robotic hands to return fine motor movement and the sense of touch back to the patient.

In one of the studies a Swedish man, whose arm had been amputated above the elbow a decade ago, was given an arm that attached to his bone, nerves and muscles. By securing the prosthetic to his bone with a titanium rod and attaching electrodes to help his muscles and nerves communicate signals between brain and prosthetic hand he was able to effortlessly move the hand.

This added a new range of precision in his movements and he has been able to use his hand for a wide range of activities. Performing work related tasks, tying his daughter’s shoes and handling eggs are all successfully executed based on communication between the man’s brain and prosthetic hand.

The second study followed two men had electrodes implanted around their nerves and experiments were conducted to determine if the electrodes created any sense of touch. After several tests and alterations to algorithms, the men were able to experience a significant amount of sensation in their prosthetic hands. One man reported feeling 19 different points on his hand while another reported 16.

The sensations were refined enough that the men were able to differentiate between textures and locations of stimulus when presented with two simultaneous objects. They could identify objects based on touching them, such as cotton balls, running water and sandpaper.

Both men reported sustained experiences of sensation when previous studies has seen those sensations fade, sometimes in as little as a few weeks. Even more, the study reports that both men were able to perform tasks that require fine motor skills thanks to their ability to feel the object they held. For example, they were able to remove the stem from a cherry without crushing the fruit.

As an unpredicted bonus, both men reported significant decreases in the amount of phantom pain they felt were their limbs had formerly been.

Researchers from this study point out that the important thing for the participants is the ability to feel the world they are interacting with. Co-author of the study, Dustin Tyler said of one of the men, “he just wants to feel his wife hold his hand.”