Through a massive joint effort between Harvard, USC, MIT, BioSensics and Carnegie Mellon’s Yong-Lea Park, patients suffering from neuromuscular disorders like multiple sclerosis, cerebral palsy or stroke may have hope for redeveloping lower leg and ankle muscle control lost due to their conditions.
Traditionally, rehabilitative prosthetics have been built around rigid exoskeletons that fully support a patient’s limb but are short on flexibility. In Park’s new design greater flexibility is achieved by eschewing yesteryear’s rigid exoskeleton; however, this comes at the expense of limited control.
To make up for this loss, Park’s new design employs a series of long, tubular pneumatic artificial muscles (PAMs), lightweight flexible sensors and advanced control software to regain the most important properties of a ridged exoskeleton.
When connected to the human body, the flexible robotic prosthetic uses a foot bed to anchor the system. With a human limb in place, the foot bed is connected to the thigh by means of long tubular PAMs that run up the side and back of the patient’s leg.
To control the constriction of the PAMs, “hyper-elastic strain sensors” generate and send signals to the prosthetics control system as they flex and contort into new shapes. With its lightning quick reaction the new prosthetic can actuate a patient’s limb immediately, simulating natural movement. Through the use of advanced controls the new prosthetic could theoretically help patients retrain their neuro-muscular systems – giving them the ability to conquer maladies like drop foot and equinius.
Currently, Park’s device is still early in its development and requires more work to make it wearable. Once that hurdle is crossed the new device could begin testing with patients who require lower leg and ankle rehabilitation.
Only time will tell if the new, bio-inspired prosthetic will help patients in the future, but what is certain is that robotics is quickly becoming an essential tool for augmenting human ability.
Image and Video Courtesy of Carnegie Mellon Robotics Institute