Brace Yourself
How might we increase access to affordable, easy to repair prosthetic devices for third world country users?
Skills Used
Project Overview
The Brace Yourself team conducted research on foot prosthetics of single transtibial amputees. For our project, we chose Vietnamese rice farmers as our primary stakeholder. These rice farmers are living in a third world country where access to materials to make a prosthetic device, as well as the expertise needed to maintain the device, is hard to come by. After conducting interviews with single transtibial amputees, conducting research on anthropometric factors, and developing prototypes, we were able to develop a prosthetic foot made out of materials in third world countries with an increased range of ankle motion.
Leading Research Finding
In 2010, there were over 100,000 amputees in Vietnam and a 3-4% annual increase is expecteddue to the number of unexploded landmines present in the country.
User Research and Conceptualization
To develop an understanding of the lives of amputees and prosthetic wearers, we interviewed 8 individuals on their experiences. The journey map to the right highlights the users experience in being properly fitted for the device, as well the process for periodically adjusting the foot. The foot prosthetic connects to a transtibial leg prosthetic with a socket joint that connects to the residual limb. For an experienced user, the process takes around ten to twenty-five seconds.
Iterative Brainstorming
Our team took on an aggressive approach in our initial conceptualization phase. We each took 40 minutes to develop 10 sketches, as well as rapidly prototype 3 of these ideas. Seen to the left was my rapid prototype which was used to show my idea of having a ball-like ankle to increase the amount of rotation a user can achieve.
Having determined the design inputs our device needs, such as being lightweight, flexible, and affordable, we were able to assess these initial ideas for the criteria we need and hone in on the best prototyping solution.
My Contributions & Final Prototyping
In heading into our final prototype, I was responsible for conducting strength testing on various shapes of base plates for the foot. I measured applied force to failure and found the shape of wood that failed at the highest force. I also experimented with bending and kerfing the wood, which was found to not reduce the strength of the wood. Additionally, I developed the final SolidWorks model and assembly as seen below. The rendering modeled our device using appropriate materials and also had FEA Distributed Stress Testing completed on the used materials.
The final physical prototype was coated in a protective coating called Shellac, which is native to southeast Asia. The parts would need replacing every couple of months, but the simple design would allow anyone, regardless of education level, to be able to replace parts as needed. The device is able to withstand about 700 N of force, which is equal to the entire weight of a 170 lb person, so it could support the average Vietnamese man. The design also features a silicone bumper around the ankle to provide rebound for easier movement as well as to protect the components.
