Simple Limb

 

Simple Limb Initiative

I am founder and director of the Simple Limb Initiative, an open-source collaboration resource for designing, developing, and producing low cost prosthetics for amputees around the world.

 

Building prosthetics that are affordable, durable, and manufacturable and repairable locally is a major challenge in many developing parts of the world. Prosthetics sourced from developed countries such as US or Europe are far too expensive. And even prosthetics sourced from other developing countries can end up being too costly. For example, the pioneering Jaipur Foot, developed by BMVSS organization in India, is inexpensive and works well – in India. But its design and materials are less ideal in other locations, and if shipped from India its cost becomes prohibitive.

I’m currently partnered with Mahavir-Kmina, located in Colombia, which is the country 2nd-most affected by landmines, after Afghanistan. Mahavir-Kmina are the only clinical site in the Americas to offer the Jaipur Foot, knee, and lower leg prosthetic components. (The lower leg components are fabricated on site, while the foot and knee are imported from BMVSS.) Together we are seeking ways to create prosthetics that are more viable and cost-appropriate for Colombia. Current testing is being done on a new knee and a new foot design, that both come in at a manufactured cost of under $40.

Outcomes

  • Open source resource of tested designs for lower-limb prosthetics
  • Production cost of under $40
  • Designs suited for local manufacture and maintenance

Students: Juniper Smith, Travis Ng, Daren Law

Students: Neil Rotroff, Kevin Somarriba, Kai Yang

Students: Will Tenney, Daren Law, Claudine Zafra

Students: Fred Miller, Phillip Priolo, Grant Snyder

The engineers and prosthetists at Mahavir-Kmina have developed, in collaboration with a professor at the Escuela de Ingeniera de Antioquia in Medellin, Colombia, a new measuring and fitting process that allows amputees to gain a more natural gait when they are fitted with their new prosthetic. This new process requires the development of new socket design, new knee design, new foot design, and new connector and component design – all at lower costs than the BMVSS products. Our current work revolves around developing low cost design solutions for the foot, knee and socket that incorporate 3D printing technologies for mold-making and for parts design and fabrication. The goal of the project in the near term is to design modular parts that can be upgraded as a child grows into adulthood, at a low cost and using a regional production/distribution process.

I direct the research in the US, and my industrial design students at San Jose State University participate by designing, building and testing prototypes.

Students: Vincent Bjorge, Amaranta Hernandez, Gouichi Tanaka

Students: Juniper Smith, Travis Ng, Daren Law

Mahavir-Kmina Knee & Foot Testing

Simple Limb Initiative worked with three SJSU students to further develop the Amputeam knee, and the Stance Foot. These fully functional prototypes are currently undergoing testing and another round of development.

The 3D printed metal prototype is being tested for functional integration with the user’s gait, while more derivative designs are being developed that can be manufactured using traditional CNC methods. This will cut the cost of the product significantly. The goal is to have one knee design with two to three different cost options.

Knee joint students: Neil Rotroff, Kevin Somarriba, Kai Yang.
tance Foot students: Anthony Ta, Brendan Ngo, Darren Manuel

This video shows the extensive development and testing process the team went through for the Stance foot: