Hand-prostheses from the 3D printer?
Missing limbs can affect the quality of life. Prostheses are useful, however are also expensive and difficult to handle. At the University of Hiroshima in Japan has now been in the 3D printing process, a lightweight hand prosthesis is developed that responds so well to movement intentions, with your "Scissors-Stone-Papier" can play.
How this prosthesis works, explains study author Professor Toshio Tsuji: "The Patient thinks only of the movement of the Hand, and then the robot will move automatically. The robot is like a part of his body." The wearer of the prosthesis represents, therefore, a movement of the hand, for example, a fist for "Stein", and a Computer combines previously learned movements of all five fingers, to this movement. Electrodes of the prosthesis to measure electrical signals from nerves through the skin. The signals are then sent to the Computer that requires only five milliseconds, in order to decide which movement he has to perform. Finally, he sends electrical signals to the motors in the Hand.
The learning machine was trained, the movements of each of the five fingers are detected, and then combines different Patterns to be about a water bottle, or to control the force required to shake hands.
Were tested the prostheses from the 3D printer, to seven people, including an amputee, had worn for 17 years with a prosthesis. The accuracy of the prosthetic hand movements that were measured in the study for simple single movements, was above 95 percent, for particularly complex movements at a level of 93 percent.
The prosthetic hand was, however, also disadvantages: In case of long use, it can be a burden, since the carrier must constantly focus on the hand position, which leads to muscle fatigue.