Development of Transradial Prosthetic Hand

Introduction

This project aimed to design a low-cost, body-powered prosthetic for individuals with below-the-elbow amputations. The prosthetic was developed to be lightweight, anthropomorphic, and highly functional, enabling users to perform various daily tasks efficiently.

Methods

• Design and modeling — Created an anthropomorphic hand design using 3D modeling tools, incorporating a Whipple tree mechanism to allow selective control of individual fingers with a single actuation.
• Prototyping — Used 3D printing to fabricate components, including the custom socket for a precise, comfortable fit, and assembled the prosthetic with lightweight materials to ensure affordability and usability.
• Mechanism development — Integrated an elastic and cable system for quick, responsive grip transitions, and designed the wrist to allow rotation, enhancing versatility.
• Functional testing — Evaluated grip types (precision and power grips) and thumb movements (abduction, adduction, flexion, extension, and opposable motion), and tested the prosthetic's ability to handle objects with adequate grip and friction using lined fingertips and flexible palm materials.

Results

• Affordability — Maintained a production cost below $50.
• Lightweight — The final design achieved a weight of 140 grams for the end gripper.
• Anthropomorphic Design — The prosthetic closely resembles a human hand in geometry and shape, offering a natural aesthetic.
• Enhanced Functionality — Flexion and extension are enabled, with the selective Whipple tree mechanism allowing control of specific fingers with a single actuation. The thumb performs abduction, adduction, flexion, extension, and opposable motion, mimicking natural functionality, and the rotatable wrist adds versatility. The custom socket is 3D-printed for a precise, comfortable fit.
• Quick Moving Ability — The prosthetic uses a responsive elastic and cable system, ensuring fast transitions between open and closed grips.
• Adequate Grip and Friction — Lined fingertips and flexible material on the palm provide better grip and object handling.