Hand prosthesis with thumb adjustment mechanism

thingiverse

As part of the diploma thesis, a mechanical hand prosthesis was designed with a mechanism for changing the thumb's position while allowing the finger to be bent using 3D printing technology. The proposed modification of the hand prosthesis is intended to enable the setting of the thumb position, thus improving the grip manoeuvre in low-cost prostheses. The project was developed using Autodesk Inventor Professional 2017 and was based on the Cyborg Beast design, available at https://www.thingiverse.com/thing:261462. The proposed concept of the denture design includes a ratchet mechanism, which allows to change the position of the thumb in 5 variants. The aluminium tube, which is a mandrel with an axial opening, should pass through the main element of movement. A hole has been drilled at the connection between the pipe and the main element of movement, through which the thumb pulling line will be routed to the bent position. The mandrel was fixed to the main movement element using cyano-acrylic glue. Then the line was led through the prepared holes in the main movement element and the closer and further sticks, respectively. Two fragments were cut out of the mid-handle design, after deduction of which it is easier to assemble the main movement element together with a mandrel with an axial opening.