Redox

Today's safer brain implant

Mar 15, 2017

Star Wars fans around the world should be happy to know we're making progress towards mind control, aka The Force (not exactly in the way the movie portrays, but by harnessing the brain’s complex neuron web to restore vision in the blind, movement in the paralyzed, and steadiness in the elderly).

Luckily, Brain-machine interfaces are advancing at a rate faster than Disney can bring us new Star Wars movies. Just five years ago, electrodes were the only implant technology available for this kind of repair.

The problem with these electrodes were that they were the size of a stamp. As Dr. Shelley Fried explains, “it was like using a bazooka to shoot ants”. They could stimulate the neuron they intended to, but at the cost of stimulating hundreds of others, leading to unwanted side-effects.

These electrodes also didn’t fare well in biological environments. For one, the electricity often left scar tissue in the brain. Since scar tissue doesn’t conduct electricity, this brain tissue became useless. Secondly, chemicals in the brain didn’t react so well with the electrodes and would erode tissue over time.

But these issues didn’t stop a team from Harvard and Palo Alto Research Center from iterating on the concept—they created a new kind of implant that is safer, more precise, and uses magnetic fields to stimulate the neurons.

They’re called microcoils and they're made up of thinner-than-a-strand-of-hair copper coils configured in such a way that they create a strong magnetic field, when electricity passes through.

Because of their size, microcoils have a much finer activation control of specific neurons, and because of their magnetism, microcoils can penetrate scar tissue, making them ideal for long-term use. They also are wrapped in a biocompatible silicon sheath, which prevents the microcoils from eroding in the brain.

Microcoils and magnetism could be the future of brain-machine interface

Using magnets to tweak brain activity sounds bizarre, but scientists have long harnessed magnetic fields to treat severe depression and anxiety through a method known as Transcranial Magnetic Stimulation.

The only limitation, just like electrodes, has always been the lack of precision.

However, with the smaller targeted areas microcoils can stimulate, researchers are excited at the possibilities.

What problems could they solve?

Initially, researchers believe they can restore vision to the blind.

After a successful trial run with mice, they have made plans to work with primates. They believe that with these microcoils, there will be no need for prosthetic eyes—if they can get the right results in the visual cortex, essentially, they can recreate what someone is "seeing" through activity waves in the brain.

Basically, a sensor would take in the light from someone’s surroundings, which would be translated into activity the visual cortex could understand. This would produce a surrounding the person could see in their head.

They're hoping to launch human trials by 2018. Should that go well, they believe this could be used in regions of the brain to help those with Parkinson’s disease or depression, and augment neural prostheses such as cochlear implants. Microcoils could even prove effective outside the brain, perhaps to stimulate the millions of neurons in the gut to help irritable bowel syndrome or obesity.

Microcoils may not be the most effective neural implant in ten years, but they are opening up a lot of opportunities for reasearchers to better understand how we can overcome the divide between functional brains with nonfunctional bodies.

Often times, healthcare gets a bad rap for being a boring industry, but then I learn of amazing innovations like microcoils and other digital health innovations nobody knows of, and I realize that healthcare is more innovative than anything Google, Apple, or Uber are doing right now.