Arm for Luke
Photo from Luke's visit in the beginning of April. He got to try on the team's first functional prototype and use it to shake his Dad's hand.
About the Project
The team is excited to work with Luke, a sixteen year old boy who’s learning how to drive. Luke experienced amniotic banding and, as a result, his right arm didn’t grow past his bicep. Currently he has trouble shifting gears while driving because he needs to reach his left arm across his body. Our team is creating a prosthetic that will allow him to drive more safely.
The arm uses one DC motor attached to a pulley that controls a whipple tree mechanism, which is a type of force distributor, to close his four fingers apart from the thumb with an activation button on the palm and a release button on the forearm.
On our recent design, we wanted the thumb to be controlled by the motor as well, but now we are designing a stationary thumb with torsion hinges at the joints because if the motor controlled thumb can only close to one position, we figured it would be better to have the freedom to move the two thumb joints with his other hand and grasp different sized objects. The arm's wrist and elbow also use torsion hinges as joints, while suponation and pronation movement are controlled by a bearing lock.
The team isolated the wiring so Luke won’t have to interface with any part of the circuit besides the battery to turn the arm on and off. The socket team got a mold of Luke's residual limb on his recent visit and made the first version of the socket modeled We are using a BOA closure system so that lacing can be tightened around the body of the pin-lock prosthetic.
About the Team Lead: Emily Hubbard
I'm a second year from Madison, WI majoring in Mechanical Engineering with an interest in biomechanics. I joined QL+ my first year because I heard about the real, hands-on opportunities offered by the club, outside of the classroom. The engineering design process excites me and I decided to become more involved with QL+. I’m currently the Webmaster, but I also assist with Quarterly Design Projects. I love the various aspects of QL+ that allow students to learn skills which can be applied to projects during their time at Cal Poly and in future professional settings.
The team with Luke and the arm prototype in front of the QL+ lab.