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ORTHOTICS, PROSTHETICS, AND ASSISTIVE TECHNOLOGY IN COCHABAMBA, BOLIVIA

Robin W. McCall, BSME Northwestern University, Evanston, Illinois

ABSTRACT

Assistive technology in Cochabamba, Bolivia is provided by private workshops and volunteers. The workshop of Carlos Guaman specializes in prosthetics and orthotics, but wheelchairs, crutches, and other devices are fabricated on request. Materials are difficult to acquire, components are custom fabricated, and most tools are made from scrap materials. Creativity and hard work leads to the creation of functional and durable devices.

BACKGROUND

Carlos Guaman of Cochabamba, Bolivia has been trained in many areas of assistive technology through courses and experience in South America, Europe, and the United States. His educational background is in mechanical engineering and technology. The author, a mechanical engineering graduate student with experience in rehabilitation engineering, spent a month working in the workshop and in the Centro de Rehabilitacion Cochabamba (CERECO).

OBJECTIVE

The goal of the project was to learn about the methods of assistive technology service provision in Cochabamba, Bolivia.

METHOD

The first phase of the project involved observing and working with the physical therapists (PTs) at CERECO. The PTs were educated in two year programs similar to the physical therapy assistant programs found in the US Most of their equipment was donated by various humanitarian organizations. The majority of their patients were children with contractures, Down's Syndrome, cerebral palsy, and undiagnosed physical and mental disabilities. Most of the patients were able to walk with little or no assistance. Those that could not were carried. Wheelchairs were very rare, the majority of which were imported from the US and Europe and not very practical for the Bolivian terrain. A typical therapy session included applying hot pads to the affected area, stretching, at CERECO and strengthening exercises with ankle or wrist weights, a weight machine, and a stationary bicycle. Most patients had therapy a few times a week, while some came every day. After working with some of the patients for several days, it was suggested that some could be assisted by splints and orthoses. Splints were made from splinting materials donated to CERECO. Hook and loop fastener for securing the splints was cut off of other equipment and sewn or glued to the splints. Fabricating orthoses was a much longer process. One patient's knees hyperextended when

Fabricating knee orthoses was a much longer process.  One patient's knees hyperextended when he walked. In order to improve his gait, knee orthoses were designed to prevent the hyperextension. Tracings and measurements were taken of the patient's legs. Materials used in the orthoses came from items donated for the project and items in the workshop. Many of the parts were taken from used orthoses. The components that were not ready-made were fabricated from local materials, such as the leg bands that were made from aluminum automotive trim. As with the hand splints, much of the hook and loop fastener material was taken from other devices. The straps were made from several different locally produced fabrics. The original design, with metal leg bands, proved to be difficult to align, so the bands were replaced with polypropylene. In the process of realigning the orthoses for the new bands, some of the parts broke due to fatigue. Replacements could not be found so only one orthosis was completed.

Ankle foot orthoses (AFOs) were requested for patients with disabilities including spina bifida, spasticity, and contractures. The process of making AFOs was similar to methods used in the United States, with modifications due to tools and materials. The patients' legs were cast to get a model for fabrication. Since no electric cast cutter was available, the cast was removed by cutting it with a knife made from a saw blade. A positive model was made by filling the cast with plaster. The positive model was finished using various tools, including files, screens, and hand-made scraping tools. Polypropylene was not available so it was decided to laminate the AFOs using polyester resin. Latex condoms were placed over the plaster model as a separating media. For some projects, a compound of melted polyvinyl acetate (PVA) bags is used instead of condoms. Layers of stockinet, fiberglass, and various types of string were used as a strengthening matrix for the lamination. In order to apply a vacuum, the model had to be contained within a PVA bag. In the United States, PVA bags are used only once and thrown away. Due to the difficulty in acquiring the material in Bolivia, the bags were reused several times and when they become unable to maintain a vacuum, they were melted and used as a separating medium. A vacuum machine that was donated to the workshop was used to achieve a vacuum. Prior to the donation, a vacuum was achieved by attaching a hose to the vacuum system of a car. The polyester resin was mixed and colored with paint. It was poured into the PVA bag through a funnel made from a plastic bottle. Once the resin was hard the AFO was cut from the plaster with a hand saw and knife. A heat gun was used to heat and soften the laminate which was then cut with a knife. Once removed from the plaster, the edges of the AFO were finished with a donated router tool and hook and loop fastener was attached with glue.

Prostheses were made using many of the same tools and materials. The most difficult aspect of making prostheses was the componentry. Exoskeletal designs were preferred because they required fewer of the difficult to acquire prosthetic components, such as pylons.

Sockets were laminated on plaster models of residual limbs. Thigh and shank portions were carved from balsa wood. If a section needed additional strength, blades from a hand saw were affixed to the wood. The workshop had one exoskeletal knee that had been donated. Whenever a knee was needed, the donated model was taken to the local foundry and a copy was made. A locking mechanism for the knee was made from local materials. The workshop had a few foreign-made SACH feet, but frequently feet were made from wood, leather, and tire rubber. Suspension systems were made from leather and other fabrics, sewn on a hand powered sewing machine. Few upper extremity prostheses were made. Most terminal devices were made from local materials. One trans-humeral prosthesis was made from components donated specifically for a patient. Other forms of assistive technology were made on request. Crutches were made from scrap metal and wood. Fabrics, plastics, and metals were used for wrist, knee, and neck braces. Special projects included a special leg orthosis to provide ischial weight bearing for a slow healing leg fracture. A few wheelchairs were made by the workshop, on request. The fabrication process involved the use of many different facilities. For example, welding was done at a friend's workshop and the surface finish of parts was applied at an automobile factory. Due to the large amount of time and travel involved, the workshop has not gone into full-time wheelchair production.

RESULTS

At the end of the project, two hand-wrist splints, one ankle-foot sleeping splint, one knee orthosis, and five ankle-foot orthoses were completed. All devices were given to the patients free of charge. Over 150 pounds of prosthetic and orthotic devices were donated to the workshop.

DISCUSSION

The work of rehabilitation providers in Cochabamba, Bolivia is an amazing study of caring and ingenuity. With very few materials and little compensation, physical therapists and assistive technology providers are able to aid many people. Educated in the most up to date methods of rehabilitation, they overcome the lack of equipment by creative use of appropriate technology.

ACKNOWLEDGMENTS

The author wishes to thank the North Carolina/Cochabamba, Bolivia chapter of Partners of the Americas for organizing this project, Heinzerling Developmental Center, Hanger Orthopedics, and Capital Prosthetics and Orthotics, all of Columbus, Ohio for their donations of supplies, and the Centro de Rehabilitacion Cochabamba and the Carlos Guaman family for being wonderful hosts.

Robin W. McCall Mechanical Engineering Technological Institute 2145 Sheridan RD Evanston, IL 60208-3111 (847)329-1651 r-mccall@nwu.edu