3D Printing and Artificial Limbs

What is 3D Printing?

3D Printing, by definition, is an additive manufacturing process that creates a physical object from a digital design. There are different 3D printing technologies and materials you can print with, but all are based on the same principle: a digital model is turned into a solid three-dimensional physical object by adding material layer by layer.

History of 3D Printing

Although 3D printing is commonly thought of as a new ‘futuristic’ concept, it has actually been around for more than 30 years. Chuck Hull invented the first 3D printing process called ‘stereolithography’ in 1983. In a patent, he defined stereolithography as ‘a method and apparatus for making solid objects by successively “printing” thin layers of the ultraviolet curable material one on top of the other’. This patent only focuses on ‘printing’ with a light curable liquid, but after Hull founded the company ‘3D Systems’, he soon realized his technique was not limited to only liquids, expanding the definition to ‘any material capable of solidification or capable of altering its physical state’. With this, he built the foundation of what we now know today as additive manufacturing (AM) – or 3D printing.

How does 3D printing work today?

Every 3D print starts as a digital 3D design file – like a blueprint – for a physical object.  This design file is sliced into thin layers, which is then sent to the 3D printer. From here on the printing process varies by technology, starting from desktop printers that melt a plastic material and lay it down onto a print platform to large industrial machines that use a laser to selectively melt metal powder at high temperatures. The printing can take hours to complete depending on the size, and the printed objects are often post-processed to reach the desired finish.  Printers can use different types of materials such as plastics, sandstone, metals, etc

What does 3D printing mean for you and me?

I had the great opportunity to visit a local library with Black Girl’s Magazine’s contributors to attend a 3D Printing session.  The session was fun and very informative.  I am the type of person that learns by doing things so to be able to sit and use the design program and create 3D images and objects was a learning experience.  At first I wanted to print a prosthetic hand but based on the program we were using the options were limited.  When I spoke to the facilitator, Sarah, she explained that a prosthetic limb would require many pieces and additional materials like wires, for example.  To print a prosthetic hand at the library would take a lot of time and be costly for me.  So, depending on what you want to print some libraries will offer a free print and then after that you would have to pay based on the size and /or weight of your project.

How is a 3D printed arm different from my Myoelectric Prosthetic?

Generally it takes weeks to create a socket, using traditional methods. This process means wrapping an amputated limb with a plaster mold in order to create a “negative cast.” This would then be filled with plaster to create a “positive cast” that can be used as a copy of the limb. A mold for the prosthesis is then created using this cast, and many adjustments are required before a final product is available.  I normally have to go in for one or two appointments for adjustments and fittings before my actual prosthesis is ready for me to take home.  Now with 3D printing, it can be done in a matter of hours. The thing that I like about 3D printing is that is makes artificial limbs available to more people all over the world in less time and the cost is lower.  The downside is that the look of the limb is not as “real” so it looks very different from an actual limb and depending on what you need the limb for it may not be as durable.

The more traditional limb, specifically a myoelectric limb that I use has more function as I can control the open/close of the hand by flexing and releasing muscles in my upper arm.  It is definitely more expensive (a myoelectric limb can cost between $18,000-$22,000) for a child.  The other benefit of the traditional prosthetic is that they have a variety of flesh tone colours to match someone’s skin tone.  If you want to show more personality you can choose to have designs on your device; like the ones I have on my recreational limb that I use for dance, bike riding, and other activities with various interchangeable attachments. 

Having an artificial limb is not only important for functional use but also to help create weight that can allow for muscle development and balance.  Creating devices that people from different communities can receive can help them to be healthy overall and give their sound limb some support so they aren’t overused.  I believe that 3D printing is a great option for creating prosthetic limbs for amputees but it may not be for everyone.  I think that each person has their unique needs and their device should fit their lifestyle and activities if possible. 

Sources:

Krassenstein, Eddie. University of Toronto Brings 3D Printed Prosthetic Legs to Children in Uganda, https://3dprint.com/44123/3d-printed-prosthetics-uganda/

Phil for Humanity.  The Pros and Cons of 3D Printing, www.philforhumanity.com/3D_Printing.html

What is 3D Printing?  The definitive guide, https://www.3dhubs.com/what-is-3d-printing