We’ve been up to a lot here at The BETH Project. Thanks in part to the support of the IDEAS Global Challenge and MIT Public Service Center, we’ve been busy prototyping, testing and talking to patients and prosthetists.
The BETH Project team first came together at a MIT H@cking Medicine conference in early 2012, gathering around Asa’s proposal to leverage desktop 3D printing technology to respond to the need of low cost prosthesis in developing countries. Early on we identified that the challenges in providing prosthetic could not be simply solved by reducing existing device cost to increase availability. We began to investigate how the system of care was limiting affordable healthcare and mobility solutions for the global population.
A central problem to addressing the developing world was the lack of trained prosthetists, which essentially creates a bottleneck to meeting the demand for prosthetic care. Even today’s most advanced sockets are made using a half-century old iterative artisanal process that can take weeks and requires expensive specialized machinery. The limited labor force in combination with the overhead costs results in care facility consolidation making it even more challenging for patient with limited mobility to access the care they need. The World Health Organization estimates there is a shortage of 40,000 prosthetists in the world today and at the current rate it will take 50 years to train another 17,000. This insight led us to design our solution from the ground up instead of trying to attach our ideas onto the existing fabrication and care paradigm.
As with many personal medical devices, understanding the challenges requires getting up close and personal with the problem. Unless you are close to a loved one who wears a prosthesis or you work in the industry, you would not be aware of the daily routines and maintenance that comes with using an artificial limb. After speaking with amputees who have worn prostheses from anywhere from a few months to sixty years, the one concern that came up over and over again was comfort. The difference between comfortable and uncomfortable is quite subtle and a common means to adjust for greater comfort is to grind the hard socket as shown in the image below.
The socket is the core component to a comfortable fitting prosthesis because forms a crucial interface between an amputee’s residual limb and his or her prosthesis. Structurally sockets are unique in that they are required to carry heavy loads and function as an extension of our skeletal structure, but at the same time provide a comfortable interface where contact is made with an amputee’s soft muscle and skin tissue. Our goal of providing a comfortable fit with a simple fitting process led us to explore socket material alternatives. Conventionally, this is the rigid composite receptacle that is attached to the top of lower-limb prostheses. Unlike the rest of the prosthetic limb, which is generally a standardization part, the socket must be custom fabricated for each individual then painstakingly fitted, adjusted and replaced over time. Ill-fitting sockets are common because of the natural volume changes in our bodies which leads to and uncomfortable fit and if not adjusted, sores that can lead to infections that ultimately compromise amputee health and mobility.
The BETH Project is focused on addressing these challenges with an adjustable socket design that provides the ability to accommodate natural volume changes and reduce pressure on sensitive areas to promote faster healing of sores while extending the usability of a prosthetic limb. Our chosen material provides the opportunity to tap the benefits of mass manufacturing rather than local fabrication, thus lowering costs for all care providers and creating a consistent quality standard for sockets. In places where trained personal and facilities are a premium we hope to relieve care providers from the complexities of socket fabrication, and in some cases providing the opportunity for physical therapists who have transferable skills to fit and provide rehabilitative care to amputees.