Aymara — indigenous people of South America — use their weaving skills to create occluder devices invented by a team of pediatric cardiologists from La Paz, Bolivia. The devices are used for the treatment of large congenital heart defects in children. Each device is woven of a single nitinol strand without connections, which makes it more durable. Structural memory of nitinol allows the device to regain its shape after collapsing inside the catheter that delivers it to the defect site.