Understanding the brain
Patients with simulation implants could someday customize the charge that hits their body.
“Electrical stimulation is a pulse of electricity,” said Tay Netoff, biomedical engineering professor who directs the University of Minnesota Center for Neuroengineering. “When we deliver it, we can change the amplitude or the voltage, the width of the pulse, and the frequency.”
“If we just select those three parameters, there are millions of possible settings.”
Netoff and his team have been building a sophisticated model to narrow those settings for individuals, by capturing data on how the brain responds to stimulation across ailments.
“What we’ve done in the past is pick a setting and fix the pulse and frequency, and then when the neuromodulation device gets used for, say, Parkinson’s or epilepsy, we have one setting we hope works for most people,” he said.
“But we’re now starting to move into the era of being able to record brain activity and seeing how that individual brain responds to the stimulation.”
So instead of one-size-fits-all, neuromodulation of the future for pain, movement disorders, and neurological disorders is giving way to a Netflixlike system—one that can offer recommendations and enhance user experience, Netoff said.
“We want to tune it not only to make it personalized,” he said, “but personalized for what a patient wants. With spinal cord injury, for example, this could be bladder function for one person or leg movement for another.”
Scroll down for more neuromodulation experts—or read how researchers are using origami to treat aneurysms."
With M Physicians Interventional Psychiatry Clinic, Professor Tay Netoff identifies neuromodulation settings for patients with treatmentresistant depression.
Netoff joins a Hennepin County Medical Center spinal cord implant study, where all 20 paralyzed patients see benefits; one moves her legs after 23 years. Read the BME department web story.
UMN neurosurgeons are using Netoff’s algorithms in a five-year, $2.2 million National Institutes of Health study to optimize deep brain stimulation for epilepsy. Read the UMN news story.
Netoff is part of the E-STAND study using epidural spinal cord stimulation to restore function in those with complete spinal cord injury and paraplegia. Read the research abstract on Experts @ UMN.
TWO PROFESSORS PAVE UNPRECEDENTED PATHS IN MAGNETIC STIMULATION
Professor Jian-Ping “JP” Wang, the Robert F. Hartmann Chair in Electrical and Computer Engineering, is developing nanomagnetic materials and quantum spintronic devices for both precision and personalized medicine. MagPatch is one example. Under Wang’s guidance, Renata Saha (EE Ph.D.’23; now DuPont scientist) led the construction of microcoils that can emit a magnetic charge on individual neurons. The impact is promising for vagus nerve stimulation.
Emad Ebbini, professor of electrical and computer engineering, is a leader in transcranial focused ultrasound (tFUS). His team has developed a dual-mode technology to treat atherosclerosis—one that combines ultrasonic sound waves to form an image and guided thermal therapy to stimulate the nerves. Minnesota startup International Cardio Corporation licensed his technology in 2011. Ebbini continues to refine tFUS for other tissue deformities.
By Joel Hoekstra
Origami, for many people, evokes images of folded paper art like cranes or sharply angled boats. For University of Minnesota engineering Professor Richard James, however, origami is a world of mathematical calculations that can be applied to design problems in fields ranging from architecture to aerospace to medical devices.
“The classic application of origami design is in space structures,” said James, a McKnight professor in aerospace engineering and mechanics. “You have structures, like solar cells, that you want to deploy into space. You have to fit them inside a rocket so they take up the least amount of space. One solution? You fold them.”
James recently taught a graduate course on origami engineering and has published several papers on the topic. But it’s his research into a subfield known as curved origami, which can produce undulating and even spherical forms, that has attracted attention from around the world.
In 2022, Eckhard Quandt, vice president for research at Kiel University in Germany, approached James about using curved origami to design stents used to treat brain aneurysms.
Aneurysms are tiny bubbles or bulges that develop in people’s brains as they age, appearing in areas where artery walls are weak or thin. When an aneurysm bursts, it may result in a stroke or brain damage. To reduce the risk of a rupture, surgeons often install a small mesh tube, known as a stent, that reinforces the artery walls. But installing a stent, via the carotid artery, is tricky.
Usually crimped so it’s small enough to fit through a catheter, the device must expand and position itself correctly once it reaches the desired location. What’s more, stent design is often patient specific—the shape and size of the device must be tailored to address the nature of the aneurysm.
James, whose research focus is phase-change materials, collaborated closely with aerospace engineering and mechanics graduate student Huan Liu to address Quandt’s request. Together, the pair produced a design for an origamiinspired implant made of thin-film shape memory alloy.
In compressed form, the tiny structure can be forced through a catheter and into position; however, once lodged in place, reacting to body heat, the stent unfolds and resumes its original form. What’s more, curved origami engineering allows for considerable variation in stent design, resulting in devices that match patient needs.
Quandt is currently building several prototypes from James’ and Liu’s design.
The pair have experimented with curved origami applications in other fields, too. Liu, who recently accepted the prestigious Drinkward Postdoctoral Fellowship at the California Institute of Technology, has leveraged her knowledge of curved origami to design high-performance vertical-axis wind turbines, long seen as a failed technology.
Last year, she and James applied for a patent on the design and launched a company, WhirrlEnergy, to further the endeavor.
The potential benefits of mingling origami engineering seem to be endless, James said. But even when it’s applied to research, origami remains beautiful and fascinating.
“It’s truly a mixture of math, science, and art,” James said.