If you plan to produce a $50 below-knee prosthesis for a developing country like Indonesia, where would you start? Is it even possible, considering that a below-knee prosthesis in the Western world costs $4,000? Waag Society’s Fab Lab Amsterdam in the Netherlands and the House of Natural Fiber, a media and art laboratory in Yogyakarta, Indonesia are working on a collaborative project aimed at finding answers to these questions.

Alex Schaub, Deanna Herst, Tommy ‘Imot’ Surya, Irene ‘Ira’ Agrivina

The House of Natural Fiber (HONF) has initiated a number of projects in the surrounding area, ranging from arts and design to education and public services. In line with its consistent focus on interactivity between people and environments, HONF selects and structures its projects based on the needs of local communities.  SOCIAL DESIGN One of these projects includes research on production and fabrication processes in relation to such fields as robotics, open source, and scientists (e.g. microbiologists). One of the partner organizations that benefit from the support provided by HONF is Yakkum, a rehabilitation centre for disabled people. HONF has been collaborating with Yakkum for almost 9 years, working as a non-official mediator and facilitator through workshops in the field of arts and empowerment. The collaboration with Yakkum confronted HONF with its biggest challenge in the context of fabrication processes. Yakkum produces prosthetics and orthotics for people with physical disabilities, particularly in Yogyakarta and other urban areas in Indonesia. However, these medical aids are expensive to produce, and take far too much time; one prosthesis is finished every two weeks. The situation is particularly problematic since there are many patients who urgently need prostheses, and most of them come from poor families. The aim of the $50 prosthesis project was to enable Yakkum to provide prostheses for two people a day using Fab Lab technology.

The first step in this collaborative process took place in May 2009, when Fab Lab Amsterdam invited HONF to an introductory prosthetics workshop for an initial exchange of experiences between users and designers.  CO-CREATION The workshop covered methods, techniques and materials and included expert input from Hugh Herr, director of the Biomechatronics Research Group at MIT, and Marcel Conradi, director of the De Hoogstraat Rehabilitation Centre in Utrecht. End-user evaluation was provided by Appie Rietveld, initiator of Korter maar Krachtig, ¹ a Dutch support and advocacy group for people dealing with limb loss.

A second prosthetics workshop in January 2010 aimed to define design parameters for adjustability, to devise inexpensive, efficient methods for production, and to explore the use of local materials – using local bamboo instead of aluminium reduces production costs considerably.  TREND: SCARCITY OF RESOURCES Some very useful insights emerged, such as the discovery that the patent of the ‘pyramid adapter’, a crucial part of the prosthesis, is expired, which allowed the collaborating partners to re-engineer it.
The next step was to test a first bamboo prototype and to make it adjustable. Most prosthesis users currently depend on orthopaedists for every minor adjustment of their prostheses, but that could theoretically be avoided. Many users do not realize that they already have a lot of first-hand knowledge about their own prosthesis, since they wear them 24/7; they are the experts on their own prosthetics use. Children generally need to have their prosthetic legs recalibrated by a doctor every six months. In Indonesia, this costs a lot of time and money. An adjustable leg would enable end users to adjust their prosthetic legs themselves by feeling and experiencing the fit, measuring the prosthesis and adapting it.

Walking on different surfaces also requires adaptation of the leg. The roll-off curve of a foot changes drastically when walking on different surfaces. The majority of prostheses on the market are designed for just one standard surface. An adjustable prosthesis would enable users to manage aspects like the roll-off curve, the angle of the foot or the height of the prosthesis themselves. In Indonesia, prosthesis alignment is mainly done manually. To facilitate the process, the collaboration team started to develop tools, such as a cheap alignment laser device and a portable 3D scanner. As DIY  DIY kits, these tools could improve accuracy while remaining affordable and accessible. Besides using digital fabrication resources, the team embraced open innovation principles, drawing knowledge from the expert users in Yakkum, the designers from HONF and Fab Lab Amsterdam, academic advisors such as Professor Bert Otten (Center for Human Movement Sciences, NeuroMechanics, University of Groningen) and specialized manufacturers like Kamer Orthopedie in Amsterdam. Input from all the parties will be used in the process of developing and designing the adjustable leg. The concrete results of the $50 prosthesis project so far also include key design insights. For instance, adjustability allows end users to take a crucial step toward independence, and the visual design of the prosthesis is important to end users. In addition, knowledge transfer during production is important for empowerment and self-reliance. In terms of production, the team gathered knowledge  KNOWLEDGE on how to user thermoforming to produce quality limb sockets quickly.

The next steps will address specific, tangible end-user needs and preferences. What do users need in order to adjust the prosthesis effectively? How would they like the design to look and feel? The aim is to develop a process or method for design based on the parameters defined in consultation with ‘expert users’: adjustability, open innovation and digital fabrication. To this end, a Fab Lab will be set up in Yogyakarta with a special Prosthetics section. The collaborative team working on the $50 prosthesis project will not stop there. In the future, they plan to research options for using intelligent materials to enhance the experience and effectiveness for the end user. Another goal is to explore the use of embodied cognition. Professor Bert Otten expects the process of prosthetic design to be guided by the team’s increased insight into the development of embodied cognition in amputees as they learn to walk with the leg prosthesis. Their improved sense of dynamic balance can be observed best from the way they move and how they intuitively adjust the prosthesis. No technical insight or expertise should be needed to adjust the prosthesis optimally, as long as the design is based on embodied cognition.

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