November 22, 2016
Tom Merrill’s mind is focused on everyone else’s brains.
The National Institutes of Health recently awarded Merrill – more accurately, Dr. Thomas Merrill – a $682,000, 18-month grant toward his work to improve the outcomes of people who suffer a stroke.
Merrill, an associate professor of mechanical engineering and biomedical engineering in the Henry M. Rowan College of Engineering at Rowan University, has spent the last 11 years developing a catheter that potentially can cool brain tissue 10 times more quickly than competitive technology.
In a crisis, that’s critical. Quicker cooling, Merrill said, will help save vital organ tissue and help reduce the number of deaths due to strokes.
“Stroke is the leading cause of serious long-term disability in the U.S. Billions of dollars are at stake. We think we have an idea that can improve patient outcomes and reduce this cost,” he said.
Merrill, who conducts his research and his business, FocalCool, LLC, out of a lab in the South Jersey Technology Park at Rowan University in Mantua Township, is striving to develop a catheter that will cool tissue right where the damage is. Existing products cool the entire body and can take as long as 45 minutes to cool damaged tissue.
The engineer has earned more than $2.6 million from the National Institutes of Health; The National Heart, Lung and Blood Institute; and other funders since he co-founded the research company in 2004 with financial assistance from Dr. Jay Yadav, former CEO of CardioMems, Inc. of Atlanta and a pioneer in cardiac stents. In the early days, Merrill worked with his engineer wife, Denise, to design prototypes of the catheter in the basement of their then-home outside of Princeton.
Today, he and a small staff are in the pre-clinical stages of the project, and they are working with leading medical device makers Stryker Neurovascular, Fremont, California, and Medtronic Neurovascular, Dublin.
“We need industry input at the start so that we create the right product for the marketplace and improve our chances of eventually licensing the technology after we’ve demonstrated its effectiveness,” the inventor said.
Merrill and his associates are expanding on work they previously did on a device called the “CoolGuide Catheter.” At this stage, Merrill and his team – which includes Rowan Engineering alumni and students – are refining the device to work with stent retrievers, which are threaded through blood vessels to reach and pull out clots in the brain.
Essentially today’s technologies deploy a “removable stent” that pushes into the clot and grabs on to it physically and then pulls the clot and stent downwards away from the blockage area and into a catheter for complete removal and restoration of blood flow.
Doctors currently use a three-part system to remove clots: a large guide catheter, a micro catheter and a clot-removal (known as a thrombectomy-removal) device.
The large guide catheter goes inside the carotid artery. The micro catheter goes further into the vascular system deep into the brain. The thrombectomy-removal device, which enters through the first two catheters, does the actual work, similar to a stent pulling the clot out. Afterwards, physicians introduce warm blood into the brain.
Fresh warm blood, however, is not the best answer after a stroke, Merrill noted. It may cause reperfusion injury. When cells lose blood flow, he explained, they are programmed to die. When blood flow is reintroduced into the tissue, it is possible to re-energize the cells and to push them towards death, sometimes contributing to as much as half of the brain injury attributed to strokes.
Merrill’s goal is to have his catheters serve as a type of delivery system for the removable stents, augmenting the existing devices’ work with therapeutic hypothermia, cooling tissue and limiting damage as the stent engages and retrieves the clot and afterwards. His CoolGuide catheter would replace the standard large guide catheter.