January 5, 2018

ASU engineers developing a wireless approach to modulate nerve functions using sound waves and injectable electronics

A wounded soldier is whisked off a battlefield. To stop him from hemorrhaging, a medic injects him with a tiny capsule packed with electronics, then waves a wand over him. The bleeding ceases.

This is bioelectronic medicine, and it’s the future.

Arizona State University engineers Jit Muthuswamy and Bruce Towe are working on the cutting edge of it, developing a wireless approach to modulate nerve functions using sound waves and injectable electronics.

The research is funded by a grant from Defense Advanced Research Projects Agency of the U.S. Department of Defense. The military is interested in it both for battlefield applications as well as long-term rehab. The grant started in December.

Targeting a certain nerve very precisely with sound, light or electricity can modulate bleeding or inflammation. Ultrasound, for example, can go deep into tissue. Nerves can be stimulated with electricity via wires, but wires create a lot of problems: tugging and pulling and instability.

Putting a device inside a body and then powering it up from outside eliminates those issues.

“You do the stimulation and you take the power out — in this case sound waves — and the device stays there and doesn’t do anything to the body,” said Muthuswamy, an associate professor in the School of Biological and Health Systems Engineering in the Ira A. Fulton Schools of Engineering. “That’s the idea: it’s passive, wireless and injectable. Therefore it eliminates many of the major issues we currently have — if it’s successful. We want to get this on the nerve and then shoot a sound wave at it, and then the device converts the sound wave into electricity that can modulate the nerve function. That’s the idea.”

A variety of diseases and conditions — like diabetes, arthritis and hemorrhaging — are related to inflammation.

“They could potentially be controlled or modulated by a vagal nerve stimulation,” Muthuswamy said. “The (vagus) nerve is all over the body. You can even tap it in your ear, to change brain states, for instance. There are a whole bunch of disease states that could potentially fall within this umbrella of electronic medicine.”

The general idea is that instead of designing new drugs, it’s designing therapy based on careful administration of electricity, or modulating electrical functions of neurons in targeted places that lead to treating organs.

Muthuswamy, with collaborator Bruce Towe, now is working on how to target specific nerves.

“How much sound, electricity or light do you want to give to a specific nerve in a targeted way?” he said. “Where do you want to give it, how much do you want to give it and when do you want to give it?”

Axons are the long threadlike parts of a nerve cell that conduct impulses from the cell body to other cells. They transmit information to different neurons, muscles and glands. Thousands of axons run through different nerves.

“We don’t know what functions they correspond to,” Muthuswamy said. “All of that stuff is not very well understood.”

What should be monitored and how should it be monitored are two big questions to be answered.

“Even if I know what I should be monitoring ... I need to be able to read that and know how much energy I should put to the nerve,” he said. “The effects have already been demonstrated in some crude ways, but to make this a reliable long-term technology that can target precise axons would be the next logical thing to go. We now have a potential technology that can address this problem.”

 

Top photo courtesy of Pixabay

Scott Seckel

Reporter , ASU Now

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