The Modeling and Development of 3D Printable Orthopedic Prosthetics
This project was worked on alongside a former student of Monmouth College: Max Balagna '19. The goal of this research project was to utilize the 3D printing ability students have here on campus, and create a working prototype prosthetic that someone could possibly use one day.
Background Information
The concept of using 3D printing to make every-day objects has become increasingly popular. The development of popular items and even expensive items can be at anyone's expense with just an SD card. Nowadays, people have developed methods in which we can print houses from sand 3D printers and we can even print weapons. The possibilities of using 3D printing are endless. When it comes to the medical field, 3D printing has just started to become popular. Replacement therapies for functional prosthetics are a revolution. Websites such as enablingthefuture.org provide coding and development for printable prosthetics and are open to the public. This publicly funded page takes requests from the public and uses a 3D printer to print specialty items. More specifically, they focus on the development of specialized prosthetics. Not only do the workers have the ability to print the prosthetics, but they also have coding for the individual pieces so the public can print them if desired.
Methodology
Monmouth College has three Prusa i3 3D printers that utilize F.D.M. printing, or fused deposition modeling. These printers use heat in order to print thermoplastic material. The filament is fed from a large coil through a moving heated printer extruder head, and is deposited on the building work. The print head is moved via computer control to define the printed shape inputted from the code. STL files were downloaded from a website called Thingaverse. The STL files are then converted into G-code for a software called Slic3r can break the STL files down and my partner and I could manipulate specific designs or print settings for the prosthetic. Once the manipulations have been made, the STL is converted into G-code for the printer to print the desired object.
SLA Printing
In order to obtain a more accurate print, Monmouth College was able to acquire an SLA printer. SLA stands for stereolithographic apparatus. This type of printer provides the ability to make incredibly small and accurate prints due to the material it uses for the prints, and the method by which it creates the 3D object. SLA printers link monomers together via a photochemical process. The print is developed with a liquid resin and is cured/set with a laser and continues on layer by layer as the print continues to be formed. This printer does not use the Gcode that the F.D.M. printer uses. Rather, it uses its own software to translate the computer code into a print. This software was called PreForm. This software is specific to SLA printing in the fact that it can fit with orientation, and can tell whether the print will be a success. This software was much more user-friendly than the F.D.M. printing software. Therefor, it was much easier to customize the print to specific guidelines.
Results
Max and I decided we would develop a prosthetic with which a person would be enabled to hold a trumpet. So who would be looking for this very specific prosthetic? The answer to this question is someone who is missing their entire hand, and is looking to play the trumpet. The trumpet holder was printed using F.D.M. printing. Our second prosthetic we worked to develop was the RIT arm. This prosthetic would be used by someone who had an amputation below their elbow. Their forearm would fit into the forearm cup and velcro straps would secure the user's bicep into the prosthetic. This prosthetic utilized strings and elastic in order for the user to bend their arm at the elbow joint, and the hand would close. In order to print these very specific pathways for the strings and elastic, Max and I made use of the SLA printer. The finished prosthetic had strings that ran from the fingers to tensioners located under the user's tricep. These are used to close the hand around objects that are looking to be picked up. There was elastic pieces that were used to snap the fingers back into the open position.
