Researchers deploy an array of microscopic coils to create a magnetic field and stimulate individual neurons. The magnetic field can induce an electrical field in any nearby neurons, the identical effect created by an electrode but way more precise. They used an array of eight coils, which combined can induce electric fields using much less current per coil, and employed soft magnetic materials, which boost the magnetic strength of the coils. The researchers constructed a prototype of their coil array, called MagPatch, and encapsulated it inside a biocompatible coating.
Neural stimulation is a medical technique used to treat many illnesses affecting the nervous system. It involves applying energy to neurons to encourage them to grow and make connections with their neighbors. Treatments for epilepsy can often include neural stimulation, and similar treatments exist for Parkinson’s disease, chronic pain, and a few psychiatric illnesses.
Within the Journal of Vacuum Science & Technology A, by AIP Publishing, researchers from the University of Minnesota deployed an array of microscopic coils — microcoils — to create a magnetic field and stimulate individual neurons.
Existing devices are effective, but lack the crucial precision needed for some applications, akin to cochlear implants or vagus nerve stimulators.
“There are several neurostimulation devices available on the market — some are already FDA-approved for patient trials, some are pending approval,” said creator Renata Saha. “But each of them has one caveat — they stimulate a big population of neurons, including neighboring cells that should not purported to be stimulated. The medical device industry is searching for a tool or technique that may stimulate neurons at a single-cell resolution.”
As an alternative of using an electrode, Saha and her team turned to magnetic coils of wire. Over two centuries ago, physicist Michael Faraday described how electric current running through a coil of wire can create a magnetic field. This magnetic field can then induce an electrical field in any nearby neurons — the identical effect created by an electrode but way more precise. Nonetheless, this method comes with a significant downside.
“To attain the specified threshold of electrical field able to stimulating neurons, the quantity of current these microcoils must drive is amazingly high,” said Saha. “It is sort of thrice the quantity of current that should drive an electrode to attain the identical threshold.”
To resolve this problem, the team made two improvements. First, reasonably than a single microcoil, they used an array of eight coils, which combined can induce electric fields using much less current per coil. The authors made further improvement to those microcoil arrays by employing soft magnetic materials, which boost the magnetic strength of the coils.
“Adding these soft magnetic materials on the core of the microcoils increases the electrical field without the necessity to increase the present through the microcoils,” said Saha.
The researchers constructed a prototype of their coil array, called MagPatch, and encapsulated it inside a biocompatible coating. They then tested it with human neuroblastoma cells to show its effectiveness. The cells were affected by the magnetic fields without being harmed by the coating, suggesting the potential to make use of this device in clinical settings.
The authors plan to proceed developing and testing the MagPatch device to make sure its safety and utility. They hope it helps to enhance the following generation of cochlear implants.
