Captain Hook made prosthetic hands famous, but his was not capable of movement and had limited functionality. Today, low-cost movable prosthetic hands are fabricated quickly and inexpensively using 3D printing technology. And we now have powered prosthetic hands, but these can be difficult to use and require extensive training.
A team from Hiroshima University and other Japanese organizations have been working on a system that will allow amputees to control a powered prosthetic hand in a more intuitive way. The system relies on sensors on the subject’s arm to sense the intent to move certain muscles, relying on electromyogram (EMG) signals. The subject then trains the system to perform specific single motions. What sets this process apart from many others is that it then applies the single motion information to multiple muscle actions. Based on “muscle synergy” information, the system is able to predict the intended motions.
As a result, test subjects were able to execute single motion tasks with a high degree of accuracy, but were also able to execute multiple motion tasks without any additional learning. The tests included healthy subjects as well as one upper-limb amputee.
These experiments are just one more data point in our rapid progress towards getting human bodies and mechanical devices to work together seamlessly. They point the way to a future where amputees can pursue normal daily activities without impaired physical abilities.