Robotic suits called exoskeletons are devices that humans can wear to improve physical abilities. The newest application of these wearable robotics is improving the lives of people who suffer from movement disabilities.
These exoskeletons are examples of biomechatronics, which is the application of machinery and electronics to living participants. Northern Arizona University’s Biomechatronics Lab has developed exoskeletons for participants with cerebral palsy. Cerebral palsy can refer to a group of movement disorders that stem from abnormal brain development. It impairs the ability to use muscles, which makes everyday tasks, such as walking, difficult.
Zachary Lerner, the head of the research, is aiming to rehabilitate participants. His goal is to use exoskeletons to train the operator’s ability to walk. Walking establishes favorable movement patterns, meaning the participant develops muscle memory and gets accustomed to which nerves are working while in motion.
This training could improve participants’ ability to walk even when they are not wearing the exoskeletons, which would be a permanent improvement to their quality of life. The participants are mostly children.
“We are blessed with great participants. Interacting with them is the most enjoyable part of my job,” Lerner said.
Cerebral palsy varies in severity from one participant to another, so Lerner and his team create customized exoskeletons for each person. The team takes measurements such as height, weight, foot size, and circumference and length of legs. They manufacture and adjust each part of the exoskeleton to fit the participant’s body perfectly. The exoskeleton only attaches to the lower body, but it must be light and easy to move in. To minimize weight, the materials are mostly aluminum and carbon fiber.
Once the exoskeleton is complete, testing begins.
“One of the largest challenges the team faces is determining how much assistance the exoskeleton should give each participant,” Lerner said.
The purpose of rehabilitation robotics is to improve the body’s ability to move without aid, so the exoskeletons should help the participant without dominating their motion. Ideal movement means the operator can move comfortably and easily. The team controls how much the suit helps the participant, but they also use software that learns from the movement patterns of the operator. The software analyzes what muscles are working and determines how to best support each participant.
Early this year, the team published a milestone of their research. They developed a wireless, battery-powered exoskeleton and proved that it reduces workload on the operator. Participants used less energy while receiving assistance from the exoskeleton, making it easier to walk. This development shows that wearable robotics are a viable option for improving daily life.
The team has many goals for their future projects. One of the lab’s goals is for its participants to be able to walk between classes without assistance. The team emphasized that they want to help the children live normal lives.
“Playing sports or increasing recess activities is definitely within the realm of possibility,” Lerner said. Improving day-to-day activities and quality of life is a more immediate goal.
The benefits of rehabilitation robotics extend beyond children with cerebral palsy. Future research could assist anyone with a movement disorder. For example, Parkinson’s disease is notorious for causing shaking hands, but it impacts many aspects of life.
“Standing balance is one of the main challenges of Parkinson’s,” Lerner said. Exoskeletons could stabilize an operator, making it possible to stand or walk without issues.
Lerner also mentioned spina bifida, which is a condition where a baby’s spinal cord does not develop properly in the womb. In some cases, spinal fluid or nerves form outside of the vertebrae. Spina bifida can impair walking ability due to nerve damage, like Parkinson’s. As with cerebral palsy, rehabilitation robotics could build muscle memory to help operators walk. Exoskeletons could also help people with injured spinal columns by reducing workload on the back.
One of the Biomechatronics Lab’s other future goals is to create exoskeletons that extend to participants’ upper halves and extremities. The current designs assist the legs, but exoskeletons could stabilize the torso, which would improve balance. Robotics could also help operators establish movement patterns in the arms, which could improve other everyday activities, such as eating, drinking or reaching for objects.