Researchers at Case Western Reserve University and the Louis Stokes Cleveland Department of Veterans Affairs Medical Center (Cleveland VA) will conduct a clinical trial to compare standard prosthetic arms and hands to the sensory-enabled neural-controlled prostheses developed at the university since 2015.
The US Department of Defense Congressionally Directed Medical Research Program awarded $9.9 million for the trial, which will begin early next year by recruiting 12 people with upper-limb amputations.
“People with upper-limb-loss deserve to have better technologies that can improve their lives,” said Emily Graczyk, PhD, who is leading the research. Graczyk is an assistant professor of biomedical engineering in the Case School of Engineering and School of Medicine and an investigator at the Cleveland VA.
The implanted Somatosensory Electrical Neurostimulation and Sensing system (iSens) uses electrodes implanted in the arm that detect muscle movement to control the hand and stimulate nerves, sending touch sensation from the fingertips of the prosthesis to the brain. An implanted neural control device communicates between the electrodes and prosthesis through Bluetooth.
“The significant funding allows us to complete this clinical trial that wouldn’t necessarily get venture capital investment at this stage,” said Dustin Tyler, PhD, the Arthur S. Holden Professor of biomedical engineering and the study’s coinvestigator. “This grant will allow us to remove one big barrier to translation.” Tyler is also director of Case Western Reserve’s Human Fusions Institute, dedicated to expanding human capabilities through advanced, human-connected, ethically driven technology.
The university initially received an eight-year, $14 million grant through 2023 from the Defense Advanced Research Projects Agency for the neuroprosthetics research. Tyler and Graczyk developed the technology and stimulation techniques that allowed sensory signals to be relayed from the prosthetic hand through neural implants in the subject’s arm.
The four-year study will involve three parts over about 18 months:
- A three-month initial testing phase will document how the participants use their current prostheses. Next, each study participant will have electrodes and electronic modules implanted in their arm in an outpatient surgery. The research team will set up each participant’s neuroprosthetic system over three to six months of laboratory visits. A controller will be built to allow the participant to intuitively control the prosthesis with his or her muscle signals, and the nerve stimulation will be calibrated so the sense of touch can be relayed from sensors on the prosthetic hand to the user’s brain.
- Participants will then either be sent home with the prosthesis they were already using or the touch-enabled, multifunctional research iSens prosthesis. Participants will complete surveys about how much they used the prosthesis and for what types of tasks and how they felt about using it. They will return to the lab for monthly testing to demonstrate how they use the prosthesis. Then those who first used their normal prosthesis will get the research arm and vice versa.
- In the third phase, the participants will be randomized again into groups that use the iSens prosthesis with only touch sensation enabled or with only the advanced motor control enabled, then switch testing devices.
“We expect our neuroprosthesis to make life better for people with amputation,” said Graczyk, “but we don’t know if the biggest factor will be improved sensation or improved control, or both.”
Linda Resnik, PhD, a professor of health services, policy, and practice at Brown University will be collaborating on the clinical trial.
For information about participating in the clinical trial, contact study coordinator Jessica Jarvela at jrw20@case.edu.
Editor’s note: This story was adapted from materials provided by Case Western Reserve University.
