While-you-nosh brain imaging
The simpler headband device allows ease in monitoring for cognitive research, other applications. Drexel is a leader in the technology.
It's a scene that might be repeated dozens of times on Drexel University's campus today: A student, sitting at a table, eating pizza.
But Annie Feng is different. The sophomore nibbles on a mini pizza while wearing a headband designed to measure her brain activity. And unlike many brain-imaging machines, this device can be used at a table.
By monitoring the brains of people during meals, researchers hope to learn about the cognitive aspects of eating, and why some people stop at a single slice while others devour the pie.
This portable device has sparked the interest of researchers worldwide.
At Drexel, doctors are running tests to see if the base technology, called Functional Near-Infrared Spectroscopy (fNIR), can enhance the way they work, from studying appetite and dispensing anesthesia to training surgeons and treating patients with amyotrophic lateral sclerosis.
Drexel and its partners have spun off a firm, fNIR Devices L.L.C., which has sold about 140 of the devices in the last five years. All are for research only since the devices are not yet FDA approved for cognitive imaging.
And while other schools have fNIR brain-imaging programs, the Drexel bioengineering team is considered the global authority on deploying fNIR in the field, said Kurtulus Izzetoglu, an assistant professor who's been a part of the team since 2001.
"Anybody who wants to work in the field, first they come to us," he said. "From Israel, to Spain, Italy, Turkey, China. They all have our technology right now and, believe me, they all use it in different applications."
Dylan Schmorrow, a retired Navy captain who's now the chief scientist of an artificial-intelligence firm, echoed that appraisal.
"They've really been world leaders," said Schmorrow, who, as a program manager at the Defense Advanced Research Projects Agency from 2000 to 2005, was key in securing funds to develop fNIR's military applications.
"Their depth and breadth of knowledge of the use of fNIR is, I think, unparalleled. The Drexel team has a legacy."
The fNIR brain-imaging method is not new. In the late 1980s, Britton Chance at the University of Pennsylvania discovered a window into the brain.
He found that by shining a specific type of light onto a person's forehead, he could measure changes in oxygen levels across the prefrontal cortex, an area involved in complex functions such as decision-making, attention, and memory.
It was an important discovery because the brain uses oxygen to help power cognition. By measuring oxygen use across the prefrontal cortex, one could watch that part of the brain at work.
Chance, who died in 2010, made a device, but it was crude and bulky. And he had problems processing the signal, isolating actual brain feedback from that caused by stray light or a deep breath.
He thought the technology might be put to great medical use, but it needed to be refined.
About 15 years ago, Drexel engineers got involved.
Fueled by more than $5 million from the Defense Department, Drexel engineers honed the technology for years, making the device safer, smaller, and more accurate, and developing software for better signal-processing.
Today, the wireless model resembles a smartphone with tiny sensors for the forehead. It's portable, can be operated by a researcher after a bit of training, and sells for $30,000.
It's a sharp contrast to the fMRI machine, which can read the larger brain - not just the prefrontal cortex - but weighs tons, needs a trained technician to run, and can cost more than $1 million.
Those factors - cost and size - are why brain-watchers across the globe are using fNIR in the field.
It's being used to enhance drug-dosing for schizophrenics at a Chinese hospital, assist language-learning in an Israeli classroom, and improve traumatic brain injury care in Italy and Spain.
In Philadelphia, Dr. Michael Green, a physician who chairs Drexel's anesthesiology department, thinks fNIR could reduce a problem in his field that, while rare, has dire consequences: inadvertent awareness by the patient during surgery.
It happens when the anesthesia fails to fully sedate the patient, who then becomes partly aware of his surroundings. "It's a catastrophic event to a patient when it happens," he said. "It's a really big deal."
Green thinks that the fNIR device could measure how deeply anesthetized a patient is and warn doctors when the patient is at risk of becoming aware.
"When the brain is asleep, it consumes very little oxygen, so when the brain is starting to come to a more awake state, it will start to consume more," he said. If the device can help identify a patient's risk, "then the value of it is immeasurable."
He has collected data on about 25 patients under general anesthesia and hopes to double that within a few months.
And it just so happens that the surgeon operating on some of those patients, Lucian Panait, is set to begin his own fNIR study. He plans to strap the device to 24 medical students to gather brain data while they use a virtual-reality simulator for surgery training.
He said readings from a student's prefrontal cortex could show if the student is processing the training or is cognitively exhausted, determinations now made by exams and a master surgeon. That data on a larger scale could help medical schools design better surgery training, he said.
And hospitals could use fNIR to assess if a surgeon's brain is at risk of being overworked, especially on days when many operations are scheduled.
"The opportunities are huge. Not only that you'll be able to report on a particular individual . . . but maybe we'll also be able to look at individual surgeons and know how much endurance they have left," Panait said.
That vision of augmenting traditional assessments with objective, brain-based ones is already being pursued by Terry Heiman-Patterson, a Drexel neurologist who is using fNIR to monitor cognitive decline in ALS patients.
ALS progressively weakens the muscles and causes paralysis; it also lowers cognitive ability in about half of patients, she said.
It's key to monitor that decline since patients with less cognitive ability tend to have a harder time following care plans, she said.
Doctors now measure cognitive decline in ALS patients with written and verbal exams, but those tests, are "not as sensitive as actually looking at the metabolism of the brain, which is what fNIR does." And after the patient loses the ability to move, "you could never administer the classic tests."
With Drexel's fNIR device, she said, brain imaging can be done in an ALS clinic.
Those are just some of the uses. There are plans to use fNIR imaging in airplane cockpits to protect fighter pilots from lack of oxygen.
Banu Onaral, who's orchestrating Drexel's fNIR research, foresees a "day when your child has the iPad or whatever they have at that moment, and naturally puts [on] the tennis band and does his homework while he's wearing this thing."
And his parents and teachers can look at his brain images and say, 'Hey, my son is learning! I can see he learned how to spell.' "