Project- 3D Printed Prostheses

Hello all,

I am a graduate student currently enrolled in a clinical program for orthotics and prosthetics. I am currently pursuing a project which attempts to address the potential opportunities, obstacles, and shortfalls of 3D printing and how it relates to prosthetics, but specifically in the context of low-income countries. I was a Peace Corps volunteer for 2 years and it was during this time that I became not only interested in development work, but also with prosthetics. Anyhow, I believe that though 3D printing is still very much in its infancy, given time and funding, the opportunities for stronger and more functional prostheses will grow. I also understand that it is not so simple as handing someone in a developing country a 3D printer and expecting them to be able to sustainably print and assemble prostheses. It is my aim to capture the breadth of questions and issues which must be addressed on the overall project level, the technical level, and the clinical level and compile them into a manual, of sorts. That being said, there is very little empirical information out there about 3D printing applications outside of labs and even less regarding 3D printed prostheses. My hope is to get as much feedback from the 3D printing community, you guys, to help address issues which any prospective project might run into when trying to utilize this growing technology abroad. Below is a basic list of areas which I will be addressing. If you have any information/opinion on any of the areas your help and time would be greatly appreciated.

Overall Considerations/Preclusions
1. Access to Electricity
2. Motivation (production, research, training) (helping one or many) (include this in the intro)
3. Access to Computers and Internet
4. Technological Knowledge
5. Access to Patients
6. Supply Chain Access

2. Printer Type Considerations
1.1. Climate Influences (fan/enclosure, heated bed)
1.2. Print Capacity
1.3. Accuracy and Consistency (Part-machine vs. part-user)
1.4. Electricity
1.5. Print Speed
1.6. Pre-Assembled or Kit
1.7. Electricity
1.8. Language Influences (Tech. Support)
1.9. Cost (Filament as well)
1.10. Filament Type
1.11. Replacement Ability
1.12. Software Considerations (User interface, training time, troubleshooting)
1.13. Modification Ability (Upgrades etc.)
1.14. Opensource Community Support (Openness)
1.15. Heated Bed
1.16. Leveling and Vibration


3. Filament Considerations
a. Climate Influences (shrinkage, destruction of filament, life of product)
b. Cost (Part Cost)
c. Diameter (Interchangeability and Variety)
d. Strength
e. Precision
f. Recycle-ability (Close-loop System?)
g. Extrusion Heat
h. Grade
i. Printer Limitations (heated bed. Relate this back to printer considerations)
j. Climate and Storage
k. Finishing
l. Health
m. Spool vs. Coil
n. Quality of Supplier (Potential Issues from bad ones?)

4. Prosthetic Considerations
1. Do no Harm
2. Mechanics vs. Biomechanics
3. User Acceptance
4. Skin Irritations
5. Strength of Plastic

There's a lot out there already. Dig around YouTube, etc.

[www.youtube.com]
[www.youtube.com]

For proof of concept (prototype) 3d printing is a cheap and ideal system, you can experiment with designs without limitation other than built size. For final product you would still required standard manufacturing systems as 3d printed objects will lack the strength and durability required unless you utilizes really expensive printers that will defeat the purpose of use in 3rd. World countries.

Edited 1 time(s). Last edit at 10/10/2014 11:21AM by ggherbaz.

Quote
yoni.diamond
1. Access to Electricity
2. Motivation (production, research, training) (helping one or many) (include this in the intro)
3. Access to Computers and Internet
4. Technological Knowledge

1. Most printers work with 12 V, so a car battery would be fine. Most controllers should also be tolerant to up to 25 V, even with voltage changes during the print, so raw solar cells should work fine. Can be as low as 60 watts without heated bed.

3. No Internet needed. Computer mostly for creating/processing 3D files. Can be an old/slow one if you're patient.

4. About as much as one needs for bicycle repair is needed. Single push button is possible, but fits only to toys. And those cheap RepRap-like designs you currently see everywhere aren't exactly maintenance-free.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Sorry, but it doesn't come out of my mind an African kid running on a gravel road with a printed prosthetic leg. With current reprap printers it wouldn't last a day, and it can hurt more than helps. It is a noble idea, but not yet fisable. This type of elements are more suitable for high end commercial printers capable of printing metals or standard injection molding.

Now, just to clarify something, I think the future of 3d printing is in bio-printing so instead of printing a prosthetic arm or leg or fingers, you would be able to print new bones muscle tissue and skin tissue and surgically reconstruct any missing limb or organ.
But that will always required trained personnel and qualified technicians.

Have you looked at? [enablingthefuture.org]
They build lots of prosthetics for kids (and some adults) and cover a lot of the questions asked. I'm working on one for someone right now.

As for the printers, these ones are just using PLA, but some are using Nylon for certain parts. For the one I'm doing, the finders and joints will likely be Nylon for durability. As mentioned, most printers run off 12v, ours certainly do and you could use the new generation of Windows tablets, or small laptops to edit any files while powered off 12v adapters or 12v to usb adapters. They are doing this in Afganistan and Sudan, to the tune of hundreds of prosthetics a week (partly thanks to Microsoft, Intel and Makerbot).


Unlike Ggherbaz, I do think I could do a leg with our XL that would last much more than a day. Designed right, it could last quite a while and need only minor repairs on occasion.

However, we need to be a bit realistic here. You aren't going to be running with it, Reprap printed prosthetic leg, at least for the time being. Look at the Olympians with them, they use high tech carbon fiber for weight and springiness and they probably cost millions of dollars, they don't even look like a leg. While we can do okay against $100k prosthetics, you can't honestly compare a $40 Reprap prosthetic to a bleeding edge, million dollar prosthetic using composites, developed in a lab by dozens of scientists. It's only been recent that even the high end ones could really run. However, it's better than nothing.

Given the option of a wheelchair or printing a leg that forces me to walk slow, I'm printing a leg.

There really aren't any voltage issues. Solar panels have used inverters for years now to output 120vac or 220vac to connect to grid directly. So there is little point in accepting the limitations of 12vdc.

It is not my intention to start a debate her, but let me clarify my point. I worked in a hospital back in my country of origin and saw many kids with missing limbs, a kid likes to play and enjoy life without limitations. Explaining a kid what he can an cannot with a plastic printed prosthetic it's impossible, once they know they can walk they will run and play football (soccer). A wooden prosthetic will last longer, will resist abuse and will cost a lot less than a printed one, I helped carved ones and even reinforced them with fiberglass and metal inserts, for each knowledgeable person to print a limb on a 3d printer there is thousands of experienced carpenter. Still with all this been said a willing manufacturer can produce 100 prosthetic by the time you are finishing on on a reprap printer.

Regards.

I come from a 3rd. World country and I know how bright the future of 3d printing can be, a printed prosthetic may help some, I agree, but it not the real solution for the problem at the present time.

Quote
garyhlucas
So there is little point in accepting the limitations of 12vdc.

There is no limitation when using 12 V. In fact, using 110/230 V AC is a limitation, because you need a power supply, converting this back to 12 V.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Quote
ggherbaz
It is not my intention to start a debate her, but let me clarify my point. I worked in a hospital back in my country of origin and saw many kids with missing limbs, a kid likes to play and enjoy life without limitations. Explaining a kid what he can an cannot with a plastic printed prosthetic it's impossible, once they know they can walk they will run and play football (soccer). A wooden prosthetic will last longer, will resist abuse and will cost a lot less than a printed one, I helped carved ones and even reinforced them with fiberglass and metal inserts, for each knowledgeable person to print a limb on a 3d printer there is thousands of experienced carpenter. Still with all this been said a willing manufacturer can produce 100 prosthetic by the time you are finishing on on a reprap printer.

Regards.

Nothing says you cannot combine wood, fiberglass and 3d printing or other materials.
My thoughts were some nice heim joints.

I truly understand people's desire to help themselves and/or others who are missing limbs; that is why I am studying prosthetics and orthotics. I think that this issue is much more complex than people have made it out to be thus far and that is why I am trying to capture the technical/mechanical elements of this issue from 3Ders. There are not only significant current limitations for 3D printed prostheses, but its also not quite clear that its even the best option for many prostheses. Most amputees have lower limb loss which requires a device which can safely and reliably be worn, absorbing huge amounts of force. We cant just strap something on someone's leg and tell them to walk slowly in case it breaks. If we want to help people then we should ask the right questions and go about it in the right way. There are already many traditional prosthetic manufacturing methods in developing countries which produce stronger and affordable prostheses. Most of the current 3D printed prostheses are for unilateral trans-carpal amputees, it seems mostly like children, who have wrist flexion. This is a very small population of people, often born that way, and most users who have such amputation levels prefer using their residual limb over a cumbersome and often inefficient tool. All that being said, 3D printing is growing by leaps and bounds, and its only a matter of time before more prostheses are designed, filament materials become stronger, printers cheaper, etc. That is why I am looking for relatively objective information/opinions about the criteria listed above.