Kai Scott - Kyaro Assistive Tech

Founded in 2018 by Colman Thadey Ndetembea, Sudi Muli, and Eamon O'Brien, Kyaro Assistive Tech is a pioneering NGO dedicated to transforming lives through innovative assistive devices. Based in Tanzania, Kyaro designs, manufactures, and distributes affordable, high-quality assistive technology tailored to the unique needs of individuals with disabilities across East Africa. Our mission is to enhance mobility, independence, and overall quality of life for our users, enabling them to participate fully in their communities.

During my three-month volunteer stint as a mechanical engineer with Kyaro Assistive Tech I had the opportunity to engage in a diverse range of activities that went beyond the technical aspects of wheelchair design and manufacturing. My time in Tanzania was both professionally enriching and personally rewarding, as I not only contributed to the creation of assistive devices but also immersed myself in the local culture and community.

In addition to designing and building wheelchairs, I participated in the delivery of these devices across various regions of Tanzania, ensuring they reached those in need. I was actively involved in assessing new patients, understanding their specific requirements, and customizing solutions to meet their needs effectively.

Moreover, I had the privilege of attending a press conference, where I represented Kyaro and shared our mission and impact with a broader audience. This experience highlighted the importance of advocacy and public awareness in driving social change.

After two months of design, prototyping, and fabricating, we developed a redesigned wheelchair. The primary goal of this redesign was to reduce manufacturing time, incorporate improved engineering practices, and add features to provide additional comfort and safety to the user.

The new features include a removable table with adjustable height, individually adjustable footrest positioning, and a headrest that allows for adjustment of angle, height, and position.

The brakes feature a linkage system that allows for secure wheel locking to improve safety.

The new tubular frame uses less material and provides more rigidity through validated through FEA simulation. All of the joints are now tube-notched and MIG welded ensuring the best engineering practice is used. Previously, the chairs were fabricated through angle grinding and stick welding, resulting in the need for extensive body filler to cover the joints. With this new design, significantly less manufacturing time results from the removal of the body filler process.

Before fabrication, my new frame design was validated with FEA in Inventor. Here, I applied over-estimated loads to the wheelchair to ensure minimal deflection.

A properly designed assistive device tends to be unique to the user. One of the critical focus points of this redesign is the rear wheel placement adjustment. "Active" users prefer to have the rear wheels towards the front of the frame. Alternatively, the "safety" position is further towards the rear. This new frame had to allow for different placements of the rear axle so the "Christmas tree" was designed. It is the rear axle assembly seen in blue to the right. It allows for front-to-rear movement of the rear axle while keeping the force vertical in its strongest orientation.

Reducing cost and manufacturing time while maintaining a high-quality standard was a focus. One of the redesigned components were the brakes. Here, I reduced the manufacturing time by roughly 50% while improving the fastening method. Furthermore, this design uses 66% less material than the original.

The first project I did for Kyaro was a ladder. The "assistive devices delivered" number count was placed high on the wall and could not be safely changed. To familiarize myself with Inventor, I modeled the ladder in using the frame tool and validated the material choice and size with FEA. With the extensive amount of tube notching required to make this ladder, we developed a practice to improve accuracy and increase tool life.