Guardian Needle, MUSC Health clinicians' safer neuromonitoring needle design, debuts in OR

January 11, 2021
two people in operating room garb stand over a patient's legs
Neurosurgeon Bruce Frankel, left, looks at how the Guardian Needle is secured to the patient while neurophysiologist Jessica Barley, co-inventor, attaches another. Photo by Sarah Pack

A new product conceived of by MUSC Health clinicians, developed by ZIAN engineers and now manufactured and sold by Rhythmlink, a South Carolina medical device company, will make the operating room a safer place for health care team members.

MUSC Health used the Guardian Needle for the first time during an operation on Dec. 16. For co-inventor Jessica Barley, Ph.D., it was a moment nearly a decade in the making.

Barley is a neurophysiologist. She assists in vascular, cardiac, orthopedic, urological and neurosurgeries, monitoring the patient’s neural functioning to provide real-time information as the surgeon makes decisions about how to conduct a high-risk surgical procedure while avoiding permanent neural damage.

numerous squiggly lines in different sectors of a screen show all the neural systems being monitored 
The electrodes inserted into patients produce these signals, which allows Barley to monitor the patient's neural structures and pathways during surgery. Photo by Jessica Barley

To do this, she places as many as 40 tiny, super-sharp needle electrodes into the patient, each of which is attached to a long wire that connects to the monitoring machine.

Intraoperative neuromonitoring provides valuable information to safeguard the patient’s neurological functions, but it’s not without risk to the team in the operating room. Traditional needles are held in place by tape, and they can pop out of position and stick team members as they maneuver themselves or the patient during surgery.

Barley said that in addition to herself, she’s seen surgeons, nurses, anesthesiologists, patient care techs, X-ray techs and members of her own team get stuck. When people get stuck, they have to report the incident and go to Employee Health Services, and they can spend months waiting to see if a bloodborne disease develops. Operating room nurse Phyllis O’neal, R.N., for instance, remembers one case where she learned after she’d been stuck that the patient had Hepatitis C, a bloodborne disease that can cause cirrhosis and liver cancer.

But it was one case in particular that got Barley thinking about the design of the needles she uses. She was monitoring a little girl during surgery when her instrumentation showed the child was in trouble. Barley alerted the surgical team to the patient’s distress, and shortly thereafter the child’s vital signs plummeted. As the care team members rushed forward to begin chest compressions, Barley tried to race ahead of them to remove all of her needles before anyone got hurt.

“For me, that was such a terrible experience,” she said. She figured that someone, somewhere, must be working to improve the design of the neuromonitoring needles. But no one was, as far as she could tell. So Barley and neurologist Jonathan Edwards, M.D., chief of the Integrated Center of Clinical Excellence in Neurosciences, began working together to come up with a solution.

Their idea was a needle that would protrude only when inserted into the patient and that would automatically return into a protective cover when removed, regardless of whether removal was accidental or purposeful.

a closeup shot of the needle protruding from its protective sheath 
Barley demonstrates how the needle protrudes only when she pops it out of its protective sheath, which comes with its own adhesive. Until now, the practice has been to use bare needles that can become dislodged and stick team members during surgery. Photo by Sarah Pack

They connected with the Zucker Institute for Applied Neurosciences, or ZIAN, a medical technology accelerator embedded in MUSC.

In addition to being able to quickly raise and deploy hundreds of thousands of dollars of research and development funding, ZIAN has the engineering, intellectual property and business expertise to help clinicians’ ideas become reality, said Mark Semler, CEO of ZIAN.

The ZIAN team could spend the time developing prototypes of the Guardian Needle, figuring out which adhesive would work best and which material had the best spring rate, while also handling the intellectual property aspects and, ultimately, finding a partner to commercialize the resulting product. In a nice bit of state synchronicity, the best industry partner turned out to be just up the road in Columbia.

“We make medical devices that help connect patients to machines to either record or elicit physiologic information from the patient to help caregivers figure out what’s going on,” said Shawn Regan, CEO and co-founder of Rhythmlink International. The company’s products focus on monitoring of the brain, spinal cord and the nerves that branch out from the spinal cord.

Regan himself has experience with getting stuck in the operating room. Earlier in his career, he performed intraoperative neuromonitoring, so he’s familiar with the aggravating aftermath of being stuck — the requisite paperwork and ensuing anxiety. In one case, Regan had to go the emergency room and take several prophylactic drugs after he was stuck and the patient turned out to have several bloodborne diseases.

“Thankfully everything was fine, but it wasn’t fun,” he said.

His company had already started looking into ways to improve the neuromonitoring needles when it began talks with ZIAN and decided the Guardian Needle design was the way to go.

“It made sense,” Regan said. “This is the group we want to work with. They’ve got this really great idea, they’ve got a nice design, they have a good patent. And it turns out, they happen to be an hour and a half down the road from us, which was a wonderful coincidence and made it really nice and really easy for us to work with them.”

Rhythmlink was also Barley’s top choice for an industry partner. She was impressed from the beginning with the quality of their products and the integrity they demonstrated in every meeting.

ZIAN and Rhythmlink signed an agreement in 2017. Over the next few years, the two groups worked on design enhancements and regulatory approval. The U.S. Food and Drug Administration approved the Guardian Needle in May, and Rhythmlink began production in the fall.

In December, Barley finally got to use the product that was her brainchild. During the surgery, neurosurgeon Bruce Frankel, M.D., successfully removed an almost 7-centimeter tumor from a 70-year-old man’s spine. He was then able to reconstruct the patient’s spine using screws, rods and a cage inserted in front of the spinal cord.

a woman leans over a patient's legs. on the wall behind her is a large screen with an X-ray visible 
Barley prepares the patient. Behind her, the screen shows the tumor that must be removed. Photo by Sarah Pack

“This delicate work cannot be done safely without neuromonitoring. To have the confidence of an excellent monitoring team, using and developing cutting edge technology here at MUSC, is a source of pride for me. This technology not only allows for superb patient safety, but now an improved security for the entire team including operating room staff,” Frankel said.

In notes she wrote up for a joint appearance with Regan at a SCBIO virtual conference in September, Barley reflected on the long journey from idea to reality.

“Time is a tricky thing, in that in some ways it drags and in others it flies,” she wrote. “There were many times I felt frustrated and discouraged that the process was not moving faster (patience is no virtue of mine). But then I think of all the people that have spent their lifetimes not seeing their ideas come to life, and I am in awe of how quickly this did for me, and I am incredibly grateful.”