After speaking with my mentors it was finally time to assembly the brace. I used a type off moldable plastic that was flexible enough to be bent but strong enough to provide stability of the knee. I decided to adapt a sort of "V" design on the side to hold the knee stabilizing piece, that was also connected to the hinge, in place. That was connected to an adjustable band around the calf where the lower part of the sleeve would sit. A piece of plastic was then attached to the other side of the hinge extending upward and attached the adjustable thigh band. Below are photos of the finished project! If this brace design was made with carbon fiber it would be extremely sturdy and could possible be used in the sports industry world. This simply acts as a prototype
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When cutting the hinge pieces the laser cutter cut them smaller than originally planned making it virtually impossible to create a hinge. I had to go back to the drawing board and reassess the angles of the knee to make sure when I recut the circles the angle restriction stayed the same. Below is a picture of the hinge pieces before the modifications. As you can see the top set of pieces was just too small from a functionality standpoint. The bottom pieces were much easier to work with and assembly overall. I did end of stick to my original design of the drawing and drilled holes through the Delrin plastic and inserted a pin for the plastic to rotate on. I am very pleased with the end result even if it caused a few setbacks.The under sleeve is something unique to the brace model. It will be a wrap model which I will refer to as the "Cradle strap" or "Hammock strap" as it will hold the knee cap in place as to not let shift. This combined with the inability to hyperextend the knee when pivoting and or running will protect the ACL. Because the pelvis of women is larger due to the fact their bodies are meant to bear children, the downward angle of the thigh bones in women is sharper forcing the knees to bend toward the midline of the body putting extra stress on the ACL. To counter act this effect of women biology the sleeve will pull the knee cap away from the midline of the body toward the exterior of the body, which will be held there by the plastic "cage" component of the brace, this will place less strain on the ACL (see more male and female differences on the anatomy page). Below is a picture of the preliminary sleeve model before the velcro is sewn.To start I used a compass to find the center points of the two circles and used a 0.1 cm drill bit to drill a hole through the center of the circles. This hole is for the pin to go through to allow the plastic appendage that will be the brace support to rotate as needed. Below is a picture of the wooden brace hinge model and might consider adding a silicon gasket to provide less friction.the black appendage rotates on the pin and extends for a zero angle (straight knee) to a 135 degree angle (fully bent)As I spoke with my advisors it seemed that the correct decision instead of using the 3D printer was to cut the hinge elements using the laser cutter in the Graw Innovation Center. I learned how to use Inkscape to create an exact pdf model of what I would like to cut. We decided to cut the components out of wood first as to not waste any plastic materials. Below is a picture of the information that was sent to the laser cutter. These designs are subject to change as they are just a starting point for the final plastic hinge model. The circles are three inch diameter and will be placed on either side of the knee. The wedge piece will be adhered to the circles and will be the stopping point of the hinge so the knee will not be subject to hyper-extension. The shapes must be sent to the laser cutter using red lines or else it will not be allowed to read the shapes.The hardest part of the brace model has been designing the hinge to allow movement. This is a preliminary sketch of the elements of the hinge that I will 3D print
Hi Team ACL Fans, Emma here!
Today, my partners and I worked together to create a papier-mâché mold of Regan's knee in order to begin our hands-on work creating the knee brace. We used strips of news paper and home-made glue material in order to create the papier-mâché, and then wrapped it around Regan's knee to dry. We also took a look at different knee braces in order to see how the hinges worked, as well as to feel the different materials and figure out what we liked. Over the course of my time at Severn I have taken a variety of computer science classes. These classes have sparked an interest in me for computer programming and coding. When we chose this idea for our project and discussed routes on how to produce a brace one of the first things that popped into my mind was 3D printing. Many braces are made out of carbon fiber rather than plastic which is posing a difficult challenge. Carbon fiber is unique due to the lightness and durability of the material. Plastic is a cheaper and heavier version which can also be printed. To familiarize myself with 3D printer mechanics I have downloaded CAD software. CAD software is designed to specifically create 3D computerized models that can be sent to the printers to print. I have also researched different materials suited for 3D printing. The standard printing material for 3D models is PLA and is commonly used in everyday scenarios. However for protection purposes I have decided to go with the second most common 3D printer material which is PLA. It requires a higher temperature degree to melt and is known to be more durable and when printed correctly lighter than the PLA alternative.
Research has been moving along quite nicely however it is challenging to understand what parts of the knee need to be support more to prevent a tear or re-tear. There really is no way to tell, without CT and MRI scans if the knee is in danger of being damaged. The question I am beginning to ask if what kind of brace I should create. The three classifications of braces are rehabilitative, functional, and prophylactic (see attached PDF for more information on these three models as well as pictures explaining the positive attributes of each. As I have begun to research more and more about what kind of braces do what I have found that this expands so much further than just the original ACL tear. ACL tears can cause CI injuries (combined instabilities) which has given me the idea to create a prophylactic/ pre injury brace that targets the CI female athletes who have instabilities due to a previous knee Injury that could have caused an increased risk in a CI re injury of both ligaments.
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