Pivoting Thumb Module for Prosthetic Hand V1.2

youmagine

Updated to version 1.2, the newest Thumb Module boasts only 2 printed parts: the Body and the Pivot. A spring has been added to the ball detent and a peg made from 3mm filament holds the pivot in place on the Body. The new thumb module is narrower than its predecessor and does not interfere with thumb flexing. Positions stops are now printed in, eliminating the need for use of a 3Doodler. The Pivoting Thumb Module is an experimental accessory designed for the Raptor Hand. Examples of two-handed tasks include putting toothpaste on a toothbrush, opening a jar or cutting something with a knife or scissors. Several designs for prosthetic hands have been developed by the volunteer e-NABLE community for individuals missing fingers but possessing a partial palm and working wrist. The current e-NABLE hands utilize wrist flexion to provide functioning of the prosthetic fingers, making two-handed tasks easier for users. However, other two-handed tasks benefit from a second orientation of the thumb. The Pivoting Thumb Module was designed for the "No Thumb" Palm of the Raptor Hand and STL files can be downloaded here: https://www.youmagine.com/designs/the-raptor-hand-by-e-nable#!design-documents. The adaptive tensioner was derived from a concept by Steve Wood (http://www.thingiverse.com/thing:392970), while the value of a pivoting thumb was originally explained to me by David Dietz. The development took place at the e-NABLE Lab at Rochester Institute of Technology. Background: The user's residual palm fits into a mitten within the prosthetic's palm, and a "gauntlet" straps onto the user's forearm. Strings serving as tendons are attached to the gauntlet and pull the fingers and thumb of the prosthetic into a grasping position when the wrist is flexed. Elastics open the grip when the wrist is returned to an extended position. Most e-NABLE hand designs have the thumb oriented for two of the three basic thumb positions: Opposition, Tripod, or Pinch Position. In the Opposition Position, the thumb opposes the palm in a powerful grip and is good for tasks like holding a jar while the lid is being removed or replaced. The Pivoting Thumb Module allows users to conveniently switch between these positions. Example task: Suppose a child wanted to make peanut butter crackers for a snack. The prosthetic hand can hold the box while removing crackers from it, then shift to the Pinch Position to hold the knife and scoop peanut butter from the jar. The Pivoting Thumb Module provides an accessory for standard Raptor hands using the thumbless palm (left and right are mirror images). STL files for the Pivoting Thumb Module can be scaled on the e-NABLE "Handomatic" scaling tool, ensuring a perfect fit with the Raptor hand.