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What comes naturally to most people—to think and then do—is
difficult for stroke patients who have lost the full use of their limbs. New
research by Rice University, the University of Houston (UH), and TIRR Memorial
Hermann aims to help victims recover that ability to the fullest extent
possible with a $1.17 million grant from the National Institutes of Health
(NIH) and the President’s National Robotics Initiative (NRI).
The multidisciplinary team hopes
to develop and validate a noninvasive brain-machine interface (BMI) to a
robotic orthotic device that is expected to innovate upper-limb rehabilitation.
The new neurotechnology will interpret brain waves that let a stroke patient
willingly operate an exoskeleton that wraps around the arm from the fingertips
to the elbow.
Rice is developing the exoskeleton and UH the electroencephalograph-based (EEG) neural interface. The
combined device will be validated by UTHealth physicians at TIRR Memorial
Hermann with as many as 40 volunteer patients in the final two years of the
four-year R01 award, the oldest research
grant offered by NIH. The grant, funded through the National
Institute of Neurological Disorders and Stroke, is one of only a few projects
selected by the NRI, a collaborative partnership by the NIH, National Science
Foundation, NASA, and the Department of Agriculture to encourage the
development of the next generation of robots that will work closely with
humans.
Repetitive motion has proven effective at retraining motor
nerve pathways damaged by a stroke, but patients must be motivated to do the
work, says principal investigator Marcia O’Malley, an associate professor of
mechanical engineering and materials science at Rice and director of Rice’s Mechatronics
and Haptic Interfaces Lab.
“With a lot of robotics, if you want to engage the patient,
the robot has to know what the patient is doing,” O’Malley says. “If the
patient tries to move, the robot has to anticipate that and help. But without
sophisticated sensing, the patient has to physically move—or initiate some
movement.”
The team led by José Luis Contreras-Vidal,
director of UH’s Laboratory for Noninvasive
Brain-Machine Interface Systems and a professor of electrical and computer
engineering, was the first to successfully reconstruct 3D hand and
walking movements from brain signals recorded in a noninvasive way using an EEG
brain cap. The technology allows users to control, with their thoughts, robotic
legs, and below-elbow amputees to control neuroprosthetic limbs. The new
project will be one of the first to design a BMI system for stroke survivors.
Initially, EEG devices will translate brain waves from
healthy subjects into control outputs to operate the MAHI-EXO II robot, and
then from stroke survivors who have some ability to initiate movements, to
prompt the robot into action. That will allow the team to refine the EEG-robot
interface before moving to a clinical population of stroke patients with no
residual upper-limb function.
When set into motion, the intelligent exoskeleton will use
thoughts to trigger repetitive motions and retrain the brain’s motor networks. An
earlier version of the MAHI-EXO II developed by O’Malley, already in validation
trials to rehabilitate spinal-cord-injury patients at the UTHealth Motor
Recovery Lab at TIRR Memorial Hermann, incorporates sophisticated feedback that
allows the patient to work as hard as possible while gently assisting—and
sometimes resisting—movement to build strength and accuracy.
“The capability to harness a
user’s intent through the EEG neural interface to control robots makes it
possible to fully engage the patient during rehabilitation,” Contreras-Vidal
says. “Putting the patient directly in the ‘loop’ is expected to accelerate
motor learning and improve motor performance. The EEG technology will also
provide valuable real-time assessments of plasticity in brain networks due to
the robot intervention—critical information for reverse engineering of the
brain.”
The three institutions bring
unique perspectives to the project, O’Malley said. Rice’s robotic devices and
UH’s neural interfaces will make it possible for TIRR Memorial Hermann, led by
Gerard Francisco, director of the UTHealth Motor Recovery Lab, to facilitate
translational research to fast-track engineering findings into clinical
practice.
“This is truly an outstanding
opportunity to demonstrate how various technological advances can potentially
boost traditional rehabilitation therapies,” says Francisco, chief medical
officer of TIRR Memorial Hermann and professor and chairman of physical
medicine and rehabilitation at UTHealth. “What makes this initiative even more
exciting is that the NRI recognized the value of our collaborative effort by
awarding this grant to multiple principal investigators. This project will be
among the first to investigate the benefits of combined therapeutic
interventions to help stroke survivors.”
Source: Rice University
