Adjustable orthoses are a means for people with lower limb disability to tune their orthosis for different terrains and activities, for example hiking up a mountain, participating in a long-distance running event, or cooking in the kitchen. We are conducting a project to automatically or semi-automatically adjust a dynamic ankle foot orthosis to meet user's needs and optimize performance.
AUTO ADJUSTABLE DYNAMIC ANKLE-FOOT ORTHOSIS
Many active people with a lower limb disability use a dynamic ankle foot orthosis (DAFO). A DAFO is intended to provide enhanced energy performance over a traditional AFO. A DAFO uses a flexible posterior element (strut) to store energy during early stance phase and release that energy during push-off. The IDEO DAFO developed by the Department of Defense has had a major impact improving the quality of life of injured Service members. Some uses though find that they need two DAFOs - one for high activity use, which has a stiff strut, and one for community ambulation, which has a less stiff strut. The purpose of this research is to create a DAFO that allows variable stiffness. Stiffness is adjusted in two modes: (1) via a phone app, and (2) automatically according biomechanical data from sensors embedded in the orthosis. The project involves a mechanical design phase to create an instrumented motor-driven adjustable stiffness strut, a clinical study phase to identify relationships between the sensed variables and strut mechanical settings, and a testing phase to evaluate performance on people with a limb disability.
Project History
The motor-driven adjustable stiffness strut has been developed and undergone gait simulator and humans subject testing. Clinical studies on able-bodied participants identified relationships between the sensed variables and the strut mechanical settings. We are currently tuning the design to enhance the consistency in manufacturing and conducting additional gait simulations. A next step will be testing on people with a lower-limb disability.