Development of a 2-DoFs actuated wrist for enhancing the dexterity of myoelectric hands

Developing a prosthetic system that emulates the complexity of the human upper limb is a formidable challenge. Unfortunately, abandonment rates for such devices remain high, primarily due to the limited intuitiveness of control and poor dexterity. Specifically, inadequate wrist mobility, i.e., the absence of actively controllable flexion-extension and pronation-supination degrees of freedom, often results in subpar dexterity in upper limb prostheses. This work introduces an anthropomorphic wrist prosthesis featuring active flexion-extension and pronation-supination capabilities, integrated with the poly-articulated Hannes hand. The central focus of this study is to compare the functionality of this prosthetic system with the natural wrist movement of healthy participants, demonstrating that the biomechanical range of motion falls within that of the mechatronic system. The overarching goal is to improve the performance of trans-radial prostheses by enhancing their dexterity and overall functionality. Our preliminary findings from healthy subjects demonstrate that the incorporation of a 2 Degrees-of-Freedom active biomimetic wrist into the prosthesis can approximate human-like capabilities in upper limb prostheses. Moreover, the resulting development confirm its enhanced dexterity when operated by amputees. These results provide valuable insights into the potential applications of this technology for amputees, offering a basis for future investigations.