Volume 9, Number 1 • January/February 2001

NASA Robotics Could Help Spinal Cord Patients

NASA engineers and neurophysiologists from the University of California, Los Angeles (UCLA), are creating a robot-like device that could help rehabilitate thousands of Americans each year with spinal cord injuries.

"We are developing a prototype robotic stepper device that, when testing is complete, will become the basis of a rehabilitation approach that can potentially help some people now wheelchair-bound take their first steps," said Jim Weiss, program manager for collaborative neural repair at NASA Jet Propulsion Laboratory (JPL), Pasadena, California. "This system can do the work of three therapists and help monitor patient progress in a controlled manner."

The device, still in the developmental phase, will look like a standard treadmill with robotic arms attached to the front. The treadmill will be used in conjunction with a suspension harness used to variably support the patient’s weight while walking on the moving treadmill. The arms attach to the patient’s legs and ankles using mechanisms resembling knee braces that guide the legs properly on the moving treadmill.

The robotic stepper device is one of several projects in the Neural Repair Program supported by the UCLA Brain Research Institute and JPL. UCLA neurologists now believe that by using the robotic stepper device as a rehabilitation approach, many patients functionally confined to wheelchairs currently may be able to learn to walk again, and those with limited movement could improve their level of functional walking. Researchers emphasize the robotic stepper is still under development and is not yet ready for use in rehabilitation. However, the device could be part of clinical trials at UCLA by 2004.

"We see tremendous potential for rehabilitation that uses this form of therapy," said Dr. Reggie Edgerton, Professor in the Departments of Physiological Science and Neurobiology at UCLA. "Some rehabilitation centers around the world are starting programs that will allow therapists to train individuals afflicted with spinal injuries, stroke and perhaps other neuromotor disorders to improve their mobility and stepping capacity," Edgerton said. "This robotic device could help therapists in those rehabilitation efforts."

Current rehabilitation therapies are labor-intensive, requiring up to four therapists per patient. Unlike therapists, who can only estimate and observe a patient’s progress, the robotic device takes precise force, torque, acceleration and resistance measurements of the patient’s movement, assessing each step the patient takes on the moving treadmill. These precise measurements would help therapists monitor the day-to-day progress of their patients and provide valuable information on the effectiveness of the therapy. These measurements will be analyzed every millisecond by a model-based control system to assist the therapist in controlling the therapy.

JPL robotic engineers have worked alongside UCLA neurophysiologists and therapists to develop the device, which has highly sensitive sensors that collect up to 20 different data readings per leg while the patient is walking on the moving treadmill. The device, connected to a computer, displays the information on a screen for therapist monitoring and assessment of the patient’s progress.

According to Weiss, the same device could also be useful in helping to maintain normal astronaut movements in differing microgravity situations, and then help retrain them to walk normally prior to their return to Earth after prolonged periods in space, such as extended missions on the International Space Station.

JPL and UCLA are actively pursuing efforts to commercialize the robotic system. JPL technically supported UCLA in filing a patent application in August.

"Many technologies developed at NASA for space exploration have tremendous medical applications. We can provide practical solutions based on our engineering experience," said Dr. Antal Bejczy, senior research scientist and lead engineer on the robotic stepper device at JPL.

For more information, contact Jim Weiss at (626/354-5420) James.R.Weiss@jpl.nasa.gov Please mention you read about it in Innovation.