2018 Volume 24 Pages 115-123
This study deals with an above-knee prosthesis that allows amputees the ability to ascend and descend stairs with no external energy supply. Our previous study certified that our hydraulic system, which is propelled by antagonistic actions of the knee and ankle joints, enables an individual to ascend and descend stairs as well as walk on flat surfaces. However, the device requires an operations manual of the flow control valve (FCV) of the hydraulic system prior to ascending stairs in order to interlock the knee joint and the ankle joint. Moreover, it has obstacles which deteriorate the walking gait, such as being unable to reproduce a double knee action. This paper discusses a solution for these difficulties as well as subsequent developments to provide amputee a walking gait which is liken to a normal one. We combined a new flow control valve (FCV) into the hydraulic system which is automatically driven while the individual is walking. The walking experiments certified that the new mechanism provides a double knee action that normally appears in healthier persons’ walking gaits, and it also provides a smooth transition from level walking to ascending stairs. However, instabilities were discovered when descending stairs.
