The U.S. National Institutes of Health (NIH) wants better ways to treat disease with electrical stimulation, and last week announced the recipients of more than US $20 million in funding for the field. The awards aim to improve maps of the peripheral nervous system—the body’s electrical wiring—and generate sophisticated systems that can hack into its codes.
The funding is part of a $248 million, seven-year program that the NIH Common Fund announced in 2014. Last week’s awards mark the start of the core of that program. Up to $39 million in additional awards will be announced next year. The agency will begin accepting applications for those awards by early 2017, says NIH’s Gene Civillico, who heads up the funding program, called SPARC, or Stimulating Peripheral Activity to Relieve Conditions.
Researchers have for decades been electrically stimulating the brain, the spinal cord and peripheral nerves in an attempt to alleviate ailments such as Parkinson’s disease, epilepsy, pain, and paralysis. The technique can work as well or better than drugs, leading some to dub the field “electroceuticals.” Several companies sell such devices with approval from the U.S. Food and Drug Administration (FDA).
The tools on the market are surprisingly simplistic. In most systems, a pulse generator blindly sends electrical impulses along a lead to electrodes that are placed on a nerve. With enough intensity, the stimulation causes neurons to fire. Those induced impulses, called action potentials, are just like the ones produced naturally by the body. The signals travel along neural networks in different temporal patterns, communicating with the body and influencing chemical and biological processes.
The problem with current devices is that they shoot electrical impulses broadly at nerves in patterns that don’t begin to mimic the body’s natural code. It’s miraculous that the body responds at all to these crude signal patterns. And often the devices activate entire nerves, rather a subset of particular fiber groups, wasting battery power and creating side effects.
That leaves a lot of room for improvement—an exciting prospect for engineers. Many more diseases could be treated with electrical stimulation if the devices were designed more elegantly, say leaders in the field. New designs for electrodes and other tools must better interface with the body and activate nerves that are currently out of reach. And such tools must selectively activate key fibers within the nerve that perform specific functions, these leaders say.
To do that, we need a better understanding of the anatomy of neural circuits—where they are and what they do. We also need to know the precise signal patterns neural circuits use to communicate with organs. In other words, if we want to hack the system, we need maps and codes.
Those are the kinds of breakthroughs NIH Common Fund intends to stimulate with the awards. “We’re seeing a fair bit of clinical success, but with fairly primitive understanding of what the stimulation is actually doing,” says Civillico.
The awards focus on treating conditions such as heart disease, asthma and gastrointestinal disorders. The program’s leaders want researchers to focus on peripheral nerves—those that connect the brain and spinal cord with the rest of the body—because of their potential direct effects on organ systems and their accessibility. (The brain is far more complex, and harder to map.)
The NIH distributed the $20 million among twenty-seven research teams. The majority went to projects that aim to develop functional and anatomical maps of neural circuits. But some research groups were able to secure cash for technology projects. We’ve picked a few of those to highlight:
- An optical probe to stimulate groups of fibers within the vagus nerve that innervate the pancreas. ($434,887) The team, led by Richard Weir at the University of Colorado in Denver, aims to develop a compact multiphoton microscope that can both read and control neuronal activity.
- Microelectrode arrays that record and map the electrical signals that control the heart as it beats and moves. ($313,980) The cardiac-neural mapping devices will consist of two-dimensional and three-dimensional arrays containing hundreds of high definition electrode contacts on a thin-film grid. The project is headed up by Jeffrey Ardell at the University of California Los Angeles.
- A wireless implantable system-on-a-chip to monitor the neural signals that control stomach contractions. ($328,909) The device could be implanted laparoscopically or endoscopically through the stomach, and will be tested first in pigs. The proposal comes from Aydin Farajidavar at the New York Institute of Technology.
- A suite of soft, permanently implantable microscale devices that can modulate the nerves of the bladder. ($363,188) The team is led by Robert Gereau at Washington University and John Rogers at University of Illinois at Urbana-Champaign (known for his soft electronic materials).
- Ultrasound technology that can record neural activity noninvasively in the body. ($274,592) The project aims to improve the resolution of ultrasound technology and tailor it to real-time recording of neural activity. Headed up by Mark Okusa at the University of Virginia.
- A nanowire that can be threaded into the carotid sinus nerve to study hypertension. ($285,600) The device will record and possibly stimulate activity of the carotid sinus nerve in rats. It can absorb collagen, allowing for long-term implantation. The team, led by Dominique Durand at Case Western Reserve University, plans to test the hypothesis that the cortid sinus nerve’s activity increases with the development of hypertension.
- New uses for existing devices. Three teams were awarded funding to repurpose commercial devices made by Nuviant Medical, Boston Scientific and CVRx. Brendan Canning’s team at Johns Hopkins University will study the use of Nuviant’s Synapse device, previously used for deep brain stimulation, for treatment of asthma ($541,305). Jiande Chen’s team from Johns Hopkins will work with a Boston Scientific spinal stimulation device, approved for chronic pain, to address gastroparesis, a disorder that affects the movement of food and is common in diabetes ($623,732). Jieyun None Yin at Transtimulation Research, Inc will take CVRx’s carotid baroreceptor stimulation device for heart failure and see what it can do for diabetes ($474,125).