Inside the operating room: Doctors test a revolutionary brain-computer implant

Keefer was undergoing brain surgery to relieve symptoms of Parkinson’s disease—but since his skull would be open for around four hours anyway, he had also agreed to have an experimental device called a brain-computer interface temporarily implanted.

The unit, developed by Precision Neuroscience, sat on the surface of Keefer’s brain for 25 minutes, reading his mind. During that time, he performed a series of exercises with his hands while engineers matched his brain signals to his movements.

The goal is to train a device that will give paralyzed patients the ability to operate a computer with their thoughts.

Precision is one of several companies vying to commercialize brain-computer interfaces, or BCIs. On Wednesday, Elon Musk’s Neuralink introduced the first person implanted with its interface. In a nine-minute presentation streamed on X, Noland Arbaugh, a 29-year-old quadriplegic, used his thoughts to play a game of chess.

Physical movement originates with electrical signals in the brain that are passed through the spinal cord or brain stem, but when someone is paralyzed, the signals hit a dead end. BCIs provide a digital bypass, capturing the signals at the source and relaying the commands to a computer.

The need is massive, according to Dr. Benjamin Rapoport, chief science officer and co-founder of Precision. There are 400,000 severely impaired patients today, he said, and 30,000 or so new patients each year. BCIs could help them win back a measure of independence.

“In order to be a citizen of the world in 2024, to communicate with loved ones, to make a living, the ability to work with a digital system is indispensable," said Rapoport, who was also a co-founder of Neuralink. “To operate a word processor is totally transformative."

The patient

Keefer, 71, had readily consented to participate in the experiment and allow a Wall Street Journal team to observe. He was aware of the time and expense involved in any effort to advance medicine, and his own journey had been long.

Seventeen years earlier, he had walked into a neurosurgeon’s office to see about a twitch in his arm. The diagnosis was swift, and devastating: You have Parkinson’s disease, the surgeon said.

“I was shocked," recalled Keefer, who was then chief financial officer of DuPont.

Mild symptoms—like Keefer’s tremor—appear first. Over time, shaking, stiffness, rigidness and freezing set in. The ability to control movement, or to move at all, diminishes. At the end, many patients struggle to swallow. A leading cause of death is aspiration pneumonia, an infection that occurs when food or beverages are breathed in instead of being swallowed.

Faced with that bleak outlook, Keefer made a decision: “I could go home, sit down by the TV and retire from life because of depression, or I could pick myself up and go do something worthwhile," he said.

Since then, Keefer has donated his time and a small fortune to Parkinson’s causes, serving on the boards of multiple Parkinson’s organizations and at one time chairing the Michael J. Fox Foundation.

The experiment

On the day of his surgery, Keefer arrived at Pennsylvania Hospital in Philadelphia at around 8 a.m. to prep for surgery. Under doctor’s orders, he hadn’t taken his Parkinson’s medication that morning, and his right arm was rocking continuously, as if he were rattling a doorknob that wouldn’t open.

In pre-op, engineers outfitted him with a pair of closefitting black and blue gloves equipped with sensors—like the kind Hollywood uses for motion-capture animation.

“It’s just like a golf glove," Keefer said, waving and smiling.

To calibrate the sensors, the team directed him to make a fist, rotate it, open and close his fingers, drum his fingers midair, stroke his palm with his thumb, hold up a flattened hand and make a peace sign.

At around noon, he was wheeled into the operating room, where his neurosurgeon, Dr. Iahn Cajigas, peeled back a bit of scalp and drilled a dime-size hole into each side of his skull. The portals would later allow Cajigas to treat Keefer’s Parkinson’s with deep brain stimulation.

But first, the surgeon slipped the brain-computer interface onto the surface of Keefer’s brain.

Keefer, who had been lightly sedated, was awakened, and the study began. On cue, he performed three of the gestures that had been calibrated earlier: Rock. Paper. Scissors.

Images of the gestures appeared in random order on a computer screen that had been placed in front of him. As he matched each one using his left hand, the word “SUCCESS" flashed across the screen in large green letters.

Then Keefer was instructed to imagine making the gestures as they appeared on the screen, without moving his gloved hand.

Nearby, a pair of computers displayed and recorded his brain signals. The thoughts appeared as a swirling wash of colors on a grid of dots—a visual representation of the electrodes that were picking up Keefer’s brain activity in real time.

“That’s the product," Rapoport said. “This is the purpose. To confirm that we can know what the brain is trying to say when there is a thought with no movement."

The device

The BCI temporarily implanted on Keefer’s brain was Precision Neuroscience’s Layer 7 Cortical Interface.

The floppy implant is roughly 5 inches long, a half-inch wide and thinner than a human hair. Its exterior, a flexible yellow polymer, conforms to the brain’s surface and envelopes 1,024 electrodes on one end and a connector on the other.

The device’s name is a wink at the six layers of the brain that work together to coordinate sensory inputs with motor outputs, translating, for example, visual and audio information into movement. The intention is for Precision’s interface to act as a synthetic seventh layer.

In the future, when the BCI is implanted during a dedicated surgery, its electrodes will be placed on the surface of the brain through an incision just large enough to accommodate the array. Its connector will attach to a package of computer chips about the size of 2 1/2 silver dollars stacked atop one another. The package will rest between the scalp and skull, with a wire running under the skin and down the neck, to an antenna and battery embedded in the chest.

The unit’s computer chips will connect wirelessly to an artificial-intelligence app that will translate brain signals picked up by the electrodes into computer code, which would move a mouse, type words or perform other digital tasks.

“To me, that’s incredible," Rapoport said. “It’s almost science fiction."

The innovator

Rapoport—a neurosurgeon and electrical engineer—is the innovator behind the Layer 7 interface.

A graduate of Harvard and MIT, Rapoport specializes in minimally invasive brain surgery, performing two or three operations a week, often to remove benign brain tumors, at Mount Sinai Hospital in New York.

“You can’t do this without Ben," said Michael Mager, co-founder and chief executive officer of Precision. “He has spent his professional life preparing to pioneer brain-computer interface technology."

The idea to start a company emerged in 2015, but Rapoport set aside his initial plan when Musk recruited him to work for Neuralink.

Rapoport spent around two years at Neuralink, leaving after it became apparent that he had different ideas about BCI design: While Precision’s electrodes lie on the surface of the brain, Neuralink’s are threaded into the brain’s tissues.

Rapoport believes even minimal damage to brain tissue is unnecessary to obtain high-resolution data, and a distinguishing feature of Precision’s device is that it can be implanted and removed without harming the tissue.

Neuralink didn’t respond to emailed requests seeking comment.

Precision and Neuralink are among five companies vying to move BCIs out of the laboratory and into the commercial market. The other competitors are Blackrock Neurotech, Paradromics and Synchron.

Rapoport believes the market will accommodate more than one company, and as evidence he pointed to Abbott Laboratories, Boston Scientific and Medtronic, which each manufacture deep-brain-stimulation systems and pacemakers, among other products.

“There’s room for two or three winners," Rapoport said.

The business plan

While Precision and Neuralink share a goal—to create a marketable brain-computer interface—the companies have charted different courses.

Neuralink was founded in 2016 and has raised more than $687 million in funding, according to data provider PitchBook. Last May, Musk announced that the company had received Food and Drug Administration clearance for a human clinical trial. And in January, Musk tweeted that Neuralink had implanted its first device in a human, just over seven years after the company was formed.

Precision was founded in 2021 and is rolling its device out in stages, a business decision that has allowed it to implant more devices in a shorter period—albeit none permanently. Since April, the company has implanted its device temporarily in 11 patients during clinical studies that don’t require FDA approval.

These studies—like the one Keefer participated in—must be conducted during other brain surgeries under local agreements with participating hospitals. Though temporary, they have allowed Precision to test its system and begin amassing high-resolution neural data.

Next, the company aims to implant a wired version of its BCI in patients for up to 30 days with clearance from the FDA. This first-generation device would function as a high-resolution brain-mapping tool to guide neurosurgeons during surgery.

Similar, though less-sophisticated, tools already exist, paving the way for what is known as a 510(k) clearance for new medical devices that resemble existing products. The company expects to apply for the clearance this summer and, if approved, plans to market its 30-day implant as soon as next year.

Rolling out a temporary, wired version of the BCI in the near term would allow Precision to generate revenue while it pursues its permanent device, Mager said. “We also can start making a positive clinical impact," the CEO said. In addition, the company would be developing relationships with hospitals, administrators, surgeons and nursing staff.

So far, Precision has joined with Rockefeller Neuroscience Institute at West Virginia University, Perelman School of Medicine at the University of Pennsylvania, and Icahn School of Medicine at Mount Sinai.

By 2028, the company hopes to receive premarket approval from the FDA to implant its permanent wireless device in patients with paralysis.

To be financially feasible, Mager said Precision is counting on hefty reimbursements from public and private health insurance.

“We believe paralysis is a multibillion-dollar market in the U.S.," Mager said. “It’s premised on healthy reimbursement, and when I say healthy, I mean six-figure reimbursement is going to be required to create a sustainable industry."

That might be optimistic, according to Brigit Kyei-Baffour, a healthcare consultant with Avalere, who specializes in commercializing medical devices and digital products.

“In terms of reimbursement, the market hasn’t gotten there yet," Kyei-Baffour said, “but I wouldn’t say the door is closed."

Coverage, pricing and reimbursement, she said, will likely be influenced by clinical and economic evidence of the product’s efficacy, safety and potential to improve health outcomes.

After the surgery

When Precision’s study was completed part way through Keefer’s brain surgery, Rapoport applauded Cajigas, the neurosurgeon, and passed through the operating room thanking individual members of the surgical team.

When he got to Precision’s engineers, he paused to congratulate them: “Good work, guys."

As the gang that had assembled for the BCI experiment exited the OR, Cajigas continued Keefer’s Parkinson’s procedure, this time permanently implanting deep-brain-stimulation electrodes that will ease his symptoms with controlled impulses.

A few days later, Keefer said, “Everything’s fine."

He might never benefit personally from Precision’s technology, but for him that wasn’t the point.

“We don’t want to wait years for these things," Keefer said. “We’d rather wait months. If I can be part of speeding that up and getting the information out sooner so that people can benefit, why not do it?"