Rehabilitation engineers create methods and technologies to help patients regain cognitive and/or motor function. Some of these patients might have cerebral palsy or Parkinson’s disease, have suffered a stroke or head trauma or be recovering from a spine injury. Since much of the work in this area is focused on neurological conditions and physical function, solutions rely heavily on neural, biomechanical and biorobotic engineers.
Our nervous system requires repetitive practice so that we can anticipate and plan ahead for specific types of movement, much like a pilot flying a plane or Michael Jordan making a free throw. In lay terms, this is referred to as “muscle memory” (although muscles do not actually contain the memory!). In patients with brain injuries, however, muscles experience a type of temporary—and in some cases permanent—amnesia. Their neurocircuits are damaged and so the communication must be rerouted and the function relearned. Researchers at Harvard’s Spaulding Rehabilitation Hospital are exploring how to use interactive technology to retrain the nervous system.
By interfacing with virtual interactive environments designed to accommodate sensory learning and motor response, patients can make more progress than through traditional therapy alone. Interactive therapy presents the patient with a familiar environment that has, in some way, been distorted in order to facilitate learning.
The Armeo®Spring robotic exoskeleton—developed at the University of California, Irvine and marketed by Hocoma-is being used by researchers at Spaulding to improve arm movement in stroke survivors, even several years post-stroke. The patient’s arm sits in the exoskeleton, providing gravity support that encourages greater mobility. Range of motion can be both controlled and monitored as a patient interacts with various video games designed to promote rehabilitation. The same robot is used with additional age-appropriate gaming software to aid therapy in children with cerebral palsy.
Understanding and Leveraging Neural Plasticity
The ability of the nervous system to change―known as neural plasticity―can actually be visualized in muscle and brain cells. Different cells change in different ways. Some respond well to mistakes, some to repetition, some to visualization and some die off if they are not used.
Our survival instincts make us cautious in the face of anything new. At the same time we are wired to be intrigued by new environments and experiences. This fascination and hesitation with new things slows the learning process. So researchers are exploring ways to bypass the instinct to be cautious.
At the University of Illinois at Chicago and the Robotics Lab of the Rehabilitation Institute of Chicago, researchers are looking at how the brain acquires, organizes and executes motor functions; especially how the brain comes to understand the physical and statistical properties of our environment. These researchers are exploring how the brain adapts to permanent changes in body mechanics in the hope that they will be able to facilitate rehabilitation in patients with motor deficits.