| This is a demonstration of a 12 year old boy who has been using a rigid prosthetic limb as the solution for a rare birth defect where his right thigh is shorter than his left thigh. As shown in the video the rigid prosthetic prevents the boy from a full range of motion. He cannot bend down very well and his right hip and leg moves significantly more than his left leg in normal motion. The original prosthetic is hidden under jeans in the video.
As a Purdue University senior design project, five Purdue students designed and fabricated a new prosthetic limb that mimics that of normal human anatomy. The mechanism is driven entirely by the boy's movement. This mechanism is a four bar mechanism which gives the boy a new "knee" pivot point so that he can squat like never before and ride a bike for the first time in his life.
It is composed of many custom fabricated parts. We created molds for precise carbon fiber shapes and we even had custom bearing mounts layered directly into the carbon fiber to hold the alignment of our pivot point measurements. Custom aluminum connecting links were machined and connected either by layering them into carbon fiber or with custom hardened and ground shafts with roller bearings.
Typical prosthetic limbs that are made for young children last a maximum of two years. A very active child's prosthetic may last even shorted than that. The mechanism is has been designed to account for some growth in the child's shin.
This design was entered into the Purdue mechanical engineering senior design competition against 23 other projects. We won first prize in the competition. See the article below to learn about the first place Mallott Innovation Award/
https://engineering.purdue.edu/ME/HomepageFeatures/LimbprosthesiswinsMalottInnovationAward
The next link is a article in the Journal and Courier regarding the project as well.
http://www.jconline.com/article/20090501/NEWS0501/905010344/1001/NEWS |