Original plaster cast of the hand, which has been painted to improve the scanning process
Hollie was born with Amniotic Band Syndrome (ABS), a condition that occurs when a fetus becomes entangled in the fibrous amniotic hands in the womb, thereby restricting blood flow and affecting the baby’s development. In Hollie’s case, it affected the development of her right arm, and she was born with no hand or wrist to speak of.
Designer Christopher Chappell was interested in creating a prosthetic that would work for Hollie. This was not the first project that Chappell had undertaken that involved the creation of prosthetic hands. He had previous experience with Robohand, having contributed some elements that are still utilized in the current prosthetics they produce.
Chappell quickly realized, however, that Hollie did not have enough of a palm in order to be able to operate the prosthetic as it was currently produced. He began an involved process of creation and experimentation to develop one that would work for her. He decided to make an effort to create the prosthetic using SLS printed nylon instead of the more commonly utilized fused filament printers. Building on the inherent flexibility of SLS printed nylon would allow him to integrate hinges all while creating parts that were both lighter and stronger.
While working for a 3D printing studio it was hard to find the time to undertake all of the necessary steps in the iterative process. Meanwhile, Hollie continued to grow, rendering previous measurements, and prints useless, and, of course, none of this was free.
“I spent months developing each iteration whilst scraping together the hours to work on it and the money to eventually order the parts to be printed. In February I started to work as a freelance designer full-time. this meant I was rich in time but…I had even less money to spend on the prototypes.”
Chappell estimates that each printed iteration cost between $750 and $1500 to print. As a freelancer myself, I can tell you it’s no small feet to scrape that kind of money together. So, given the worthy nature of his development, he turned to crowdfunding to get help to continue the development and production of his prostheses, not only for Hollie, but also in an effort to release as an open source design for anyone interested in creating and/or modifying the prosthetic.
“I haven’t seen anyone else try to create a prosthetic based on a scan of the users complete arm. I’m trying out different printing methods which should ultimately make manufacturing a lot easier and more reliable for these hands. I’m trying to make it as simple as possible for anyone to do this.”
Chappell has plans to release a full ‘how to’ guide once he has ironed out all the steps, but in the meantime, he is asking for just over $3,000, via a Gofundme.com campaign, in order to work through the next several iterations of the hand. In the event that donations surpass his goal, Chappell plans on experimenting with the incorporation of myoelectric elements such as motors and EMG for further control.
As you can see by the images above these prostheses are incredibly detailed and accurate, and look much more like actual human hands than other prostheses we have covered in the past. What do you think? Let us know in the SLS Printed Prosthetic Hand forum thread on 3DPB.com. Check out the video below of version 4 of the hand being tested out:
