Simulation Based Design of a Pediatric-Sized Hydraulic Ankle-Foot Orthosis

Cerebral palsy can cause gait impairments in children that require the prescription of passive ankle-foot orthoses. This project aims to develop a pediatric-sized hydraulic active ankle-foot orthosis with computer-controlled stiffness. The orthosis will allow a clinician to investigate a range of AFO stiffnesses while collecting gait performance metrics to determine the optimal stiffness value for the AFO prescription. The ankle-foot orthosis uses hydraulic technology to generate the large required torques in a light, compact package. The preliminary design uses additive manufacturing to further reduce the weight of the manifolds on the medial and lateral sides of the ankle. The simulation prototype of the design illustrated that the orthosis should be capable of generating 91 Nm of ankle torque and a maximum angular velocity of 483 °/sec. The device will be a valuable resource in the clinic, saving time and resources in the AFO prescription process while improving the healthcare of the patient.