The Venture Development Center and Physical Therapy Department at the University of Delaware (UD) have received $50,000 in seed money from the Pennsylvania Pediatric Medical Device Consortium to further develop a motorized ankle-foot orthosis (AFO) called the DE-AFO. The DE-AFO, designed by Ahad Behboodi, PhD, and his team, uses electro-active polymer as artificial muscles to assist ankle motion in children with cerebral palsy (CP). The soft muscle-like smart material contracts in response to electric current. The team also received a $200,000 grant last year from University City Science Center, Philadelphia, PA, to work on the device.
Made from off-the-shelf elastic materials, these artificial muscles closely mimic the function of the body’s skeletal muscle and can help children with CP who struggle to complete a range of motion (ROM) under their own power. The device is lightweight, compact, comfortable, and noiseless, reducing the size of the orthosis needed while increasing the wearer’s degree of freedom in movement. Computer software operates the artificial muscle.
Traditional AFOs keep the ankle and foot stable but don’t allow for movement, which can cause muscles to weaken and atrophy from disuse. The UD team’s device potentially can minimize this atrophy because it will allow muscles to go through an ROM. For example, if a child needs help lifting her toes for her foot to clear the ground as she walks, the device can assist the front calf muscles to lift up the ankle.
The researchers said they can imagine the brace being used as an exercise device, too, where the artificial muscle might resist against the child’s movements to strengthen or stretch muscles or increase ROM. Further, in the future they may add functional electrical stimulation technology to also trigger muscles, when needed. This would improve the timing and power of the artificial muscle’s activation, thereby strengthening the user’s muscles and improving walking coordination.