Design, Implementation and Evaluation of a Variable Stiffness Transradial Hand Prosthesis
This work addresses the need for customizable and functional prosthetics for amputees, representing an incremental improvement in prosthetic technology through novel actuation and control methods.
The researchers tackled the challenge of creating an affordable and adaptable hand prosthesis by developing a variable stiffness transradial hand prosthesis that uses antagonistic tendons and nonlinear springs for compliance control, resulting in a low-cost, lightweight design with high dexterity for grasping various objects.
We present the design, implementation, and experimental evaluation of a low-cost, customizable, easy-to-use transradial hand prosthesis capable of adapting its compliance. Variable stiffness actuation (VSA) of the prosthesis is based on antagonistically arranged tendons coupled to nonlinear springs driven through a Bowden cable-based power transmission. Bowden cable-based antagonistic VSA can, not only regulate the stiffness and the position of the prosthetic hand, but also enables a light-weight and low-cost design, by opportunistic placement of motors, batteries and controllers on any convenient location on the human body, while nonlinear springs are conveniently integrated inside the forearm. The transradial hand prosthesis also features tendon driven underactuated compliant fingers that allow natural adaption of the hand shape to wrap around a wide variety of object geometries, while the modulation of the stiffness of their drive tendons enables the prosthesis to perform various tasks with high dexterity. The compliant fingers of the prosthesis add inherent robustness and flexibility, even under impacts. The control of the variable stiffness transradial hand prosthesis is achieved by an sEMG based natural human-machine interface.