Robotics Tools Augment Neurorehabilitation Market

by James Cavuoto, editor

Advances in robotics technology are offering new opportunities for vendors of neurorehabilitation systems to enhance their product offerings. Robotic systems have been used in products such as the Lokomat, which helps physical therapists at 250 institutions worldwide deliver treadmill-based therapies to individuals with neurological disorders such as spinal cord injury.

In robot-assisted walking therapy, in use at institutions such as the Rehabilitation Institute of Chicago, an individual is suspended in a harness over a treadmill and the frame of the robot, attached by straps to the outside of the legs, moves the legs in a natural walking pattern. A computer controls the pace of walking and measures the body's response to the movement. It is believed that the repetitive walking pattern helps the brain and spinal cord work together to re-route signals that were interrupted by injury or illness.

At the World Congress for Neurorehabilitation held in Vienna, Austria earlier this month, Hocoma AG advertised a new version of its robotic device called LokomatNanos. Planned for release in July of this year, the new system offers more functionality for gait therapies in a more compact design.

While much of the early application of robotics in neurorehabilitation has been in lower limb function, several research institutions and commercial firms are looking to upper-extremity therapies. Hocoma plans to introduce its ArmeoPower device in 2011, which includes a robotic exoskeleton.

Researchers at the University of Genoa in Italy are developing a robotic system called “Braccio di Ferro” (iron arm) to help stroke patients learn to use their arms again. Writing in the Journal of NeuroEngineering and Rehabilitation , Elena Vergaro and colleagues report on a pilot trial of robot in 10 patients.

“Our preliminary results from this small group of patients suggest that the scheme is robust and promotes a statistically significant improvement in performance,” Vergaro said. “Future large-scale controlled clinical trials should confirm that robot-assisted physiotherapy can allow functional achievements in activities of daily life.”

The robot assists patients as they attempt to guide its “hand” in a figure-eight motion above a desk, pulling in the correct direction and resisting incorrect movements to a minutely controlled degree. This interactive assistance allows for alternating levels of help, encouraging patients to re-learn how to use their arms. Vergaro said.

“Stroke survivors perform arm movements in abnormal ways, for example by elevating the shoulder in order to lift the arm, or leaning forward with the torso instead of extending the elbow. Use of such incorrect patterns may limit their ability to achieve higher levels of movement ability, and may lead to repetitive use injuries. By demonstrating the correct movements, a robot can help the motor system of the subject learn to replicate the desired trajectory by experience.”

H.I. Krebs, a researcher at MIT's department of mechanical engineering, is also working on robotics for stroke rehabilitation. The university's MIT-Manus device was one of the first robotic systems used for upper-extremity neurorehabilitation. While other therapists have used robotics as an assistive technology for the disabled, Krebs' approach is to use robots and computers to support and enhance clinicians' productivity as they facilitate a disabled individual's functional recovery.

Krebs and his colleague Neville Hogan have cofounded a neurorehabilitation company called Interactive Motion Technologies in Watertown, MA. The company's InMotion family of products are robotic systems used in upper-extremity rehabilitation for individuals with stroke, cerebral palsy, and other neurological conditions. There are versions for shoulder, wrist, and hand functions. The company also offers an Ankle robot called Anklebot for lower-extremity applications.