Pacemakers for the Nervous System
ENG alum’s device restores function in neurologically impaired
Warren Grill was given a challenge in 2002. His soon-to-be business partner, Geoff Thrope, asked the Duke University Addy Professor of Biomedical Engineering: “You know, Warren, you’re doing a great job of being an academic biomedical engineer and publishing papers that end up in journals on a shelf. But is that sufficient?”
Since then, Grill (ENG’89) has risen to the challenge, translating fundamental research to several technologies with significant clinical impact. He and Thrope cofounded medical device start-up NDI Medical, LLC, a technology incubator that partners with academic researchers and supports in-house scientists and engineers in developing high-growth companies focused on innovative neurostimulation technologies. In recognition of his many innovations, Grill was named Neurotech Business Report Neurotechnology Researcher of the Year in 2003, and in 2007 received the College of Engineering Distinguished Alumni Award for Service to the Profession.
Upgrading the nervous system
Grill specializes in what he calls “pacemakers for the nervous system,” electronic neural prostheses that stimulate the neurological system—as a cardiac pacemaker stimulates the heart—to restore function in individuals with disease or injury. His research is distinguished by a strong emphasis on translation from computer models and preclinical studies to clinical feasibility studies with human subjects, and in some cases, commercial products.
One of Grill’s trailblazing technologies is an implantable device that uses electrical stimulation to control bladder function, both continence and emptying.
“Our research focus is on the restoration of bladder function in persons with spinal cord injuries,” he says, “but we determined that we could also use our approach to continence control to treat persons with overactive bladders.” He and Thrope initially formed NDI Medical with that in mind and developed a device to treat the condition. In 2008, they sold it to the health care giant Medtronic.
Grill is also exploring deep brain stimulation devices, “brain pacemakers” that are used to treat movement disorders such as Parkinson’s disease. He is studying ways to improve the efficiency and selectivity of deep brain stimulation, to maximize clinical effectiveness and minimize side effects—and ultimately expand the number of patients who could benefit from treatment.
“Although the technology has been used in about 80,000 people worldwide, we don’t know how it works,” Grill says. “Our objective is to understand the mechanisms and use that knowledge to improve the therapy.”
Engineering clinical solutions
Grill’s interest in the nervous system was initially piqued by his biomedical engineering senior project in the ENG Auditory Neurophysiology Laboratory of Herbert Voigt. “I gave him the opportunity to do his senior project in my lab and he did a fabulous job—he won the Senior Project of the Year Award,” says Voigt, an ENG biomedical engineering professor. “Warren was a star.”
That project—quantifying the electrical properties of nerve cells in a sea slug—effectively launched Grill’s career. “I wanted to exploit the understanding of neurophysiology to restore function,” he recalls. “The excitement I felt in doing this work sparked my interest in this career.”
At BU, Grill also developed communication skills he’s found valuable. He learned how to write convincingly in a U.S. history course, and the basics of giving professional presentations from Kenneth R. Lutchen, ENG dean and former head of the biomedical engineering senior project program.
“He impressed upon us the importance of preparation and practice,” says Grill. “I still follow that model today.”
He earned master’s and doctoral degrees in biomedical engineering at Case Western Reserve University and was on its research and primary faculty until 2004, when he joined the Duke faculty.
In 2009 two independent companies were spun off from NDI: Checkpoint Surgical, which produces an FDA-approved device that allows surgeons to identify and protect nerves in the surgical field so they’re not damaged during operations, and SPR Therapeutics, which has developed a novel approach to treating chronic pain that’s now being clinically tested.
“The excitement and satisfaction come from the translation of research to the clinic,” Grill says, “of seeing these things happen in humans.”
He attributes much of his success in translating biomedical engineering concepts into complicated methods and devices to keeping things simple. “Even though we use complex technologies to interact with complex physical systems,” he says, “I strive to break those down into elementary units so that I can understand them.”
Mark Dwortzan can be reached at firstname.lastname@example.org.
A version of this article originally appeared in the spring 2011 issue of Engineer.1 Comments