Cartee's Left Arm Case Study

This arm was designed particularly for Cartee’s left arm. Cartee’s has no elbow on her left arm. She has one degree of freedom at her wrist joint and at her finger joint. Her wrist is very small and she has two short conjoined fingers extending off of it that curve towards the right. Her forearm extending from her wrist is curved towards the left. Because of her very limited range of motion, this design relies fundamentally on electronics to be actuated. The prosthetic hand that this arm design is based off of is the InMoov hand which can be voice activated. The following will describe the mechanical design, the electronics, and the software of this arm. The forearm shield, the components in the hand, and the bicep box will all be 3D printed …show more content…
This will allow the patient to rest her arm more comfortably inside, as the shield fits exactly to her arm. The shield has dimensions 30cm x 8cm and it does not wrap around her entire forearm. It covers only the top half of her arm. The inside of the shield will be lined with polyethylene closed cell foam padding for extra comfort. We choose to use this foam for its good adhesive characteristics. It is also commonly used inside of prosthetics for padding. The shield is attached to her arm with four Velcro straps. There are slots cut from the arm along both sides of the bottom side of the shield. Two on each side for the Velcro strap, which means there are four cuts for each Velcro strap in total. These cuts are meant to stabilize the straps so that their movement is minimized. Minimizing movement will help prevent them from coming undone. We may consider using neoprene instead of Velcro as it is more secure than Velcro. In addition, as the hand and the motor placement could make the design more top heavy, we are considering adding a shoulder sling so that the prosthetic can have more support when picking up objects. This will also provide more comfort for the patient since the force at pressure points are more