Funded by the IST programme, the Cyberhand technology allows sensory feedback from the hand to reach the brain, and instructions to come from the brain to control the hand, at least in part.
The achievements of the project so far: The Cyberhand prototype has 16 Degrees of Freedom which is possible by the work of six tiny motors. Each of the fully sensitised five fingers has one motor dedicated to its joint flexing for autonomous control. It features the opposable thumb, so the device can perform different grasping actions.
Taking inspiration from the real hand, where a muscle pulls a tendon inside a synovial sheath, Cyberhand's finger cables run through a Teflon sheath pulled by a motor. So the proximal, medial and distal phalanges are all driven by the same tendon. It means the prosthesis has a self-adaptive grasp. "This is a fundamental feature of the Cyberhand prosthesis because only a limited number of control signals are available for user’s voluntary control," says project manager, Dr Lucia Beccai. Because of the self adaptive grasp less user effort is required to control the hand during daylong use.
The Cyberhand prototype integrates the two types of human senses. One senses where parts of the body are relative to other parts, whether our fingers are open or closed, for example. The other relates to taste, touch, sound, hearing and sight that tell us about the external world. CYBERHAND includes sensors for tension, force, joint angle, end stroke and contact in the final prototype.
This prototype uses Longitudinal IntraFascicular Electrodes (LIFEs) to connect the hand to the nervous system. In addition to traditional wire LIFEs a new type of electrode has been developed to improve performance and make them less invasive in humans: the Thin Film LIFE (tfLIFE).
MEDICA.de; Source: IST Results