The Hannes hand prosthesis replicates the key biological properties of the human hand.

Replacing the human hand with artificial devices of equal capability and effectiveness is a long-standing challenge. Even the most advanced hand prostheses, which have several active degrees of freedom controlled by the electrical signals of the stump's residual muscles, do not achieve the complexity, dexterity, and adaptability of the human hand. Thus, prosthesis abandonment rate remains high due to poor embodiment. Here, we report a prosthetic hand called Hannes that incorporates key biomimetic properties that make this prosthesis uniquely similar to a human hand. By means of an holistic design approach and through extensive codevelopment work involving researchers, patients, orthopaedists, and industrial designers, our proposed device simultaneously achieves accurate anthropomorphism, biomimetic performance, and human-like grasping behavior that outperform what is required in the execution of activities of daily living (ADLs). To evaluate the effectiveness and usability of Hannes, pilot trials on amputees were performed. Tests and questionnaires were used before and after a period of about 2 weeks, in which amputees could autonomously use Hannes domestically to perform ADLs. Last, experiments were conducted to validate Hannes's high performance and the human likeness of its grasping behavior. Although Hannes's speed is still lower than that achieved by the human hand, our experiments showed improved performance compared with existing research or commercial devices.

Design and testing of an under-actuated surface EMG-driven hand exoskeleton.

Stroke and other neurological pathologies are an increasing cause of hand impairment, involving expensive rehabilitative therapies. In this scenario, robotics applied to hand rehabilitation and assistance appears particularly promising in order to lower therapy costs and boost its efficacy. This work shows a recently conceived hand exoskeleton, from the design and realization to its preliminary evaluation. A control strategy based on surface electromyography (sEMG) signals is integrated: preliminary tests performed on healthy subjects show the validity of this choice. The testing protocol, applied on healthy subjects, demonstrated the robustness of the whole system, both in terms of mimicking a physiological distribution of finger forces across subjects, and of realizing an effective control strategy based on the user's intention.