It’s hard to forget Derby, the incorrigible Little-Husky-That-Could that we outfitted with 3D printed prosthetics last December. With flagless determination, Derby was all tail wags and enthusiasm over his first set of prosthetics, which we designed to help him overcome the debilitating impact of his congenitally malformed front paws. In case you missed his story, get the full impact of his amazing transformation with this video

As many noted when Derby’s story initially came out, the first version of his prosthetics kept him fairly low to the ground. This was a very intentional choice. 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. We wanted to give Derby the opportunity to gradually and comfortably adjust to a vertical status quo. Had we skipped this intermediary step and immediately addressed his height in isolation of his ambulatory abilities, his story would have evolved differently. His struggles would have outweighed his successes.

Once we were confident that Derby had adapted to his initial lift, it was time for phase two of our project. Because our first circular “blade” design was so successful, our initial thought was simply to scale the original. What we had not accounted for in this second iteration, however, was that while we managed to elevate Derby to the appropriate height, the results of the scaled design were too ungainly for easy movement. Rather than walk, play and run as he had previously, Derby simply shook his paws, trying to dislodge the oversized impediments we had given him.  

Réalisant que la tâche à accomplir n'était pas aussi simple que le peaufinage d'un succès précédent, il est revenu à la case départ pour créer une conception nouvelle. Notre objectif était de conserver une courbe adaptative identique à celle du point de contact de la prothèse avec le sol, afin que Derby puisse se tourner et jouer comme auparavant, tout en essayant également de réaliser une structure semblable à un genou afin de fournir la valeur de souplesse appropriée à la nouvelle hauteur. Notre réévaluation relative à la structure appelait également à un examen de choix de notre matériau, ce qui nous a conduit à choisir du Nylon en raison du compromis parfait entre la stabilité et la flexibilité. Afin de transformer ces concepts en prothèses fonctionnelles dans la vie réelle, nous avons alors envoyé nos conceptions vers l'une de nos imprimantes 3D de frittage sélectif par laser, qui a créé des pièces légères tout en étant durables (au cas où cela vous aurait échappé, il s'agit de la même technologie que New Balance utilise pour créer sa nouvelle ligne de chaussures de course à pied hautes performances, avec une semelle intermédiaire imprimée en  3D). Avant la fin de la journée, nous avons pu tenir notre nouvelle conception dans les mains et étions prêts à la tester.

“I can’t imagine tackling this case without 3D printing,” said Tara Anderson, 3D Systems’ project lead for Derby’s prosthetics. “The key to our ability to help Derby was being able to quickly and fluidly move from design to verification to end-use part, and back to design without losing any momentum. We were able to adapt our design to suit Derby’s evolving needs in real-time.”

When we strapped Derby into this new version, we knew we had a winner. Now up to his natural height, Derby took off at a trot, testing out his new legs with his fluffy tail wagging and pink tongue lolling. Derby’s owner, Sherry Portanova, says Derby has adapted beautifully, now sitting and walking like any other dog. “This past year has been amazing for us and for Derby,” she says. “We can’t wait to see what the future holds.”

Although 3D printing has helped Derby achieve a normal dog’s stature, we know he is anything but.

Watch Derby take his new prosthetics for a spin in the video below.