Derby the dog is different from most of his peers. He was born with no front paws and small, deformed front legs. His mobility was very compromised until he came into the foster care of Tara Anderson, an employee at 3D design and printing company 3D Systems.
We first met Derby in late 2014 when he got a set of 3D-printed prosthetics. He now has a brand new pair of front legs featuring a more advanced design.
Derby's initial artificial legs were purposefully designed to keep him close to the ground in front. "Derby's first pair of prosthetics was not only a concept test for the feasibility of the overall design, it also started the process of acclimating Derby to a new elevation," 3D Systems noted in a December 29 update on Derby's progress.
Derby's first prosthetics had a rounded designed. 3D Systems attempted to simply create a larger version of the originals to raise the pooch up to a normal height, but the result was too ungainly for Derby to use comfortably.
Anderson went back to the drawing board to create a completely new design for Derby's legs. "As we grew the design taller and taller, the structural needs changed," she said in a video update. The winning result is a modified figure-8 pattern that has a central junction that flexes slightly like a modified knee.
A Selective Laser Sintering 3D printer brought the prosthetics from concept into reality. The printer uses a laser to harden and bond together tiny grains of plastic. The same printing technology was used to create lightweight 3D-printed midsoles for New Balance shoes, so it has helped advance both human and canine locomotion. Derby took to the new design immediately and is now walking and running with a straight back at a normal dog height. "He's sitting like a real dog sits," his adoptive owner Sherry Portanova said.