Description of Proposed project

Create a design useful in developing countries for amputations below and above elbow.

Design a systems approach to upper limb prosthetics, that will better meet the need of arm amputations in the developing word. This will be a modular design that can be manufactured as parts. The final assembly and fitting can be done from a standard set of pre-made parts in a single visit with the recipient.

The design will focus on the largest population need, lower arm and mid upper arm recipients.

I have been traveling to places that have a need and, once there, we do a clinic that measures, defines a type of appropriate device and takes personal data for future delivery. We go back at some later date with newly built devices and fit them as possible. Local volunteers work to advertise the clinics, help with locale and organization logistics as well as hands-on measuring, data acquisition, etc. Unfortunately, there are many points within this system that can, and do, fail. It functions but is very inefficient. Often, it doesn’t truly address the client’s desires as to appearance, function, etc. ~ Dean Rock

Expected results/impact

The result will be a new OpenSource design for the community.

Modular

The prosthetics will be delivered to the field as components. The components are sized and assembled with the recipient.

Probably four primary components:

• Hand
• Wrist and socket for transradial recipients
• Wrist and lower arm for transhumeral recipients
• Elbow and socket for transhumeral patients

Standard Sizes

Each of these four components will be standardized to three sizes: child, small adult (a.k.a. woman), and large adult (a. k.a. male). These three sizes will fit most. The socket is very adjustable in the field. These major components will simply screw together. What these three sizes are may vary from region to region. So, the design will be scalable to any size. Maybe some region will have four standard sizes.

Easy to Manufacture

The design will be printable on most hobby 3D printers with a minimal set of not printed parts. The design will also be manufacturable by larger runs using an injection moulding process. This allows batches of 1 to 10 to be done by 3D printers, and larger batches of 10 to 1,000 to be done by injection moulding (likely using an SLA printed mould). Assembly of each of the components is done as part of manufacturing. But attaching the 3 major components is done with the recipient.

Easy to Fit

The socket is mostly soft, and cuttable by normal scissors. Fitting involves cutting excess off the soft parts of the socket, and attaching the correct size components together.

Easy to Supply

Because the system is module and a few sizes fits most. There is no back and forth between the first meeting, manufacturing , then fitting. The location or clinic is kept supplied with a regular stock of ready made components. When a recipient if found the components are sized and fitted immediately.

Balance Natural Look and Function

Because of the other limitations of this design, natural look will take a higher priority than function. In many places of the world social stigma to limb differences is very high. So, a natural look is very important. This means the design will be manual with no electronic parts.

Completely Open Source Design

The resultant design will be completely Open Source. Anyone will be able to use/modify/improve the design.

Design Inspirations

There are several designs out there that are close to meeting this need. I will be drawing heavily from these existing successful design ideas.

Skip Meetze’s Gripper Hand and Dean Rock’s module arm

This will likely be the basis for my design. The hand is functional and can be made to look very natural. This thumb is passive requiring another hand to open. I think the final design will have a passive or elbow action to open option. The design is already OpenSource.

"Give Hope - Give a Hand" - The LN-4 Prosthetic Hand

I generally like this socket design. It is simply a series of stiffeners wrapped with velcro. I think the socket can be improved to have a flexible interior wrap. This should allow it to look more natural and require only one strap at the top. I don’t thinking this design is OpenSource. But I will be using general ideas only.

LimbForge

This group has similar design goals. I do not think the design is not open source. I like the natural look. It is all 3D printed. On the downside, I think each one is custom fitted and made for each recipient.

Martin Bionics Socket-less Socket

This is a beautiful professionally made design. I do not think our arm will be this awesomely functional, but ours will be a lot cheaper and easily made and delivered around the world. It does show the inspiration of a very adjustable open socket with a natural looking arm and hand.

Create O&P, Create Prosthetics

Also, a wonderful professional design by Jeff Erenstone. I will take any input from Jeff he is willing to give.

Estimate of work effort

I think this will take me about 130 hours to get a first draft of the design. The Beta testing and feedback time is volunteer dependent so is more vague. I assume the same 130 hours again.

Estimated timeline for completion of the effort

I am assuming I can dedicate about 1/4 of my time on this project so It should take 3 or 4 months to the initial design. After that it will be released to a group of testers, and feedback incorporated into the design. That feedback and update loop can take 3 to 4 more months.

Names of individuals responsible

Jacquin Buchanan will be doing most of the design work. With test and evaluation done by others. I would hope to get feedback/input from Dean Rock, Ed Choi and others who have worked in this area before.

Amount of Funding

I will be seeking $12,500 for this project. I plan to use a GoFundMe campaign to raise the money. 10% of this would go to Enable Fund as the Fiscal Sponsor. Another 10% would go to fund raising channels. The remainder would go to Jacquin Buchanan to pay for time and materials.
I am seeking funding for this so I can get more done, faster. The Kwawu 2.0 took over a year in my spare time. I have three or four more design proposals I'd like to do after this one.

Background with e-NABLE

Jacquin Buchanan designed the Lionel arm with Jeff Erenstone, the Kwawu, and Kwawu 2.0 Arms for e-Nable.