About the Project
The Open Prosthetics Project is producing useful innovations in the field of prosthetics and giving the designs away for free. By substituting public good for profits we believe that we can generate far more societal benefit than if we commercialized and sold our ideas. This project is an open source collaboration between users, designers and funders with the goal of making our creations freely available for anyone to use and build upon.
We post progress reports to keep you up to date on what we’re doing. You can also find out why we are giving our ideas away and why Tackle Design is doing this.
Below are some recent progress reports:
New Project; Radio Appearance · 15 August 06 by Jonathan Kuniholm
We had a revalation about the origin of the rubber bands used for body-powered prostheses, and have started a new project to document potential alternatives. The initial results look promising, and we’ll post more detail than you’re probably interested in as it becomes available.
On Monday, Chuck and Jon from Tackle and Robert, who is working on two projects on OPP for his son Michael, taped an interview with Dick Gordon for his show The Story , which will air this Thursday, August 17th on WUNC, our local NPR station, at 1 pm and 8 pm. We enjoyed talking with Dick, and are looking forward to sharing the project with more people. If you missed the show, and want to hear it, contact us.
Engineering World Health Collaboration · 14 July 06 by Chuck Messer
Another open source medical project that we are ramping up in partnership with Engineering World Health has received some attention. We are assisting the winning team of the EWH Cures Competition with some pro bono design work to prepare their product for higher volume manufacturing. I was invited to help judge the competition where we selected a team to receive $100,000 in funding to start a not-for-profit business to make and distribute low-cost lights that treat jaundice.
The device, which will cast blue light onto the skin of infants, helps turn bilirubin, a harmful chemical that is not handled well by the liver, into a more harmless one that can be safely processed by the body. Tackle Design is working with the contest winners to take the design to final implementation and will host a small-scale manufacturing effort with volunteer labor to produce some of the devices to distribute to the developing world. Please contact us to find find out more about the project or how you can participate.
Prosthetic Fishing Rod · 9 June 06 by Jesse Crossen
Robert Haag has started another interesting project for his son Michael: a prosthetic fishing rod. The idea is to attach the rod as a terminal device on Michael’s prosthetic arm in place of the usual gripper. Pretty much anything can be made into a body-powered terminal device by attaching 1/2-20 male threads to it, although it’s a little harder to make it do something when you pull the cable.
The first stage of the project is to modify the rod so it can be attached as a terminal device. Below are the parts and the resulting device:
And here’s a video of Michael practicing his cast:
The following supplies were used:
- Shakespeare telescoping rod (Spider-Man model)
- Knurled plate with 1/2-20 and M12×1.5 threads
- PVC foam washer
The rod’s handle is trimmed about an inch from the base, then the inside is built up with hot glue and the knurled plate is super-glued into that. The joint is then sprayed with red Plasti-Dip to hide the imperfections. The washer keeps the rod from rotating when it’s screwed into the wrist. The next step is make the cable push the release button for smoother casting. Stay tuned for more detailed instructions on how to make your own prosthetic fishing rod.
Pediatric Trainer · 7 April 06 by Jesse Crossen
A few weeks ago, Robert Haag contacted us with a very interesting idea. His two year old son wears a body-powered gripper, and they’re trying to teach him to use it. It’s a pretty complex skill because depending on where the gripper is positioned, different combinations of shrugging motions are required to open and close it. It’s not easy for adults to learn, so imagine teaching a distractible young child to do it. Here’s a video of a training session with Rob’s son Michael:
In the video, you can see the adults giving him positive feedback when he does the right thing. This is essential to learning; the quantity, quality, and promptness of feedback directly affect the development of a skill. Rob’s idea is to build a small device that would measure the tension in the cable and make friendly sounds to tell Michael that the gripper is opening and closing. Now, instead of just being in short sessions, the feedback would be instantaneous and constant, hopefully helping him learn faster and better.
Rob had already done some work, but was stuck on a few engineering problems, so we engaged Jack Walker, a design engineer who volunteered his skills to the Open Prosthetics Project. They’re working out the details and keeping us informed. You can follow developments on the pediatric trainer project page. If you want to volunteer or offer suggestions, please contact us and we’ll put you in the loop.
Metal Trautman Hook · 31 March 06 by Jesse Crossen
We sent the Trautman Hook design off to ProMetal and the printed metal parts arrived yesterday. Today, we got finishing tools (screws, drill bits, a tap, and a die) from McMaster-Carr and put the device together. Here are some pictures of the parts when we got them:
As you can see in the closeup, the printed surface is a bit grainy, but not unattractive, and vibratory tumbling would help it look smoother. After a little drilling and threading, it went together without a hitch. Here’s the assembled device:
The action is smooth and the backlock is tight, the only issue is that the grippers don’t line up perfectly, probably due to the fingers warping a little during heat treatment. The total error is about 0.050 inches.
The next step is to test it with a body-powered harness, then we’ll try to break it to see where it needs to be stronger. Also, we’re already planning on making a few revisions that would make the device more durable. The cost of this prototype was $500 (ProMetal’s minimum order) plus about $50 for finishing tools. Thanks to Kenneth Heide, CPO for funding it.
Rapid Manufacturing · 13 March 06 by Jesse Crossen
We’ve been doing a lot of research into rapid manufacturing (RM) lately. It’s a way of building complex shapes from layers of material, and it will be how many things are made in the future. What’s most interesting about this technology for prosthetics is not the “rapid” part, it’s the fact that you can make things in very small quantities at a reasonable cost. In the prosthetics industry, this means that very small groups of users, like extreme skateboarders missing one foot, can have products made just for them at a reasonable cost. RM also makes it cheap to introduce new products, like we’re doing with the Trautman Hook. Through our consulting business, Tackle Design, we’re also exploring new applications of RM technology to prosthetics in response to a public announcement from the NIH.
Prosthetic Patents · 9 March 06 by Jesse Crossen
Another Tackle Design project, the All Patents Initiative is building tools to make the entire US patent database searchable and accessible. This will help researchers study the history of innovation and give the public access to an important part of their national heritage. The searchable data for patents before 1900 just came in from processing at HP Labs, so we did a simple search for “artificial limb”. It turned up 81 patents from 1852 to 1898, mostly for leg and foot designs. Many of these were probably developed for veterans of the Civil War. The old illustrations are beautiful, and they might contain some ideas that are still useful today. For instance, note the similarities between an 1891 patent (US Patent 450,476) and an image from this 1998 research paper:
We will continue to search old prosthetic patents for “new” ideas. Here are some more great images from the collection:
