By: Cam Ruffle-Deignan
Everyday thousands of people around the world sustain injuries that require a cast or brace to stabilize their fracture/ sprain and promote healing. Traditionally these casts were made of fiberglass, which is fairly light weight, but can be very abrasive and called for a set of thick padding to protect the skin. Additionally Fiberglass casts are particularly troublesome when it comes to getting wet because any moisture trapped inside the padding can create chaffing for patients which can develop into bacterial infections. Recently through breakthroughs in 3-D printing applications groups of people have been coming together and creating designs for lightweight and cheap casts made from printed PLA material.
Additive manufacturing by 3D printing and the medical field seem to be two highly compatible areas that could benefit each other. Sprains and fractures are injuries that are treated differently from person to person and incident to incident and CAD programs that allow for the scaling of printed parts can be implemented to tailor a brace to any individual.
Here at UVM we printed a simple cast from one of our MakerBot printers that was worn by an employee with a sprained wrist. This cast was designed to be printed as a two dimensional net, that would then be heated using hot water to be contoured to the “patients” arm. This process may sound overly involved but was in fact simple to do and required water that was almost boiling and a container big enough to submerge the 7×7 print. First the part was submerged for a few seconds until it became highly malleable. Then it was quickly taken out and pressed on the wrist with pressure on all sides to lock in the desired shape. In the picture below this particular brace used Velcro straps to be secured onto the wrist. There are other processes being explored that involve using a 3-D scanner to record exact dimensions of a patient’s body so that cast can simply be snapped into place over their limb. The later process is desired if the area of injury is highly sensitive and cannot take any loads applied to it.
This is a small example of how new advances in additive manufacturing can help solve everyday problems experienced by people of all different walks of life. 3D printing has been a technology in progress for the past thirty years and plaster casts have been used for far longer than that