Brain Implants  

A new DARPA program has been established with the goal of developing an implantable neural interface able to provide unprecedented signal resolution and data-transfer bandwidth between the human brain and the digital world.

DARPA has set up a new program aiming to develop an implantable brain interface with unprecedented signal resolution and data-transfer bandwidth between the human brain and the digital world. The interface would serve as a translator, converting between the electrochemical language used by neurons in the brain and the ones and zeros that constitute the language of information technology.

The goal is to achieve this communications link in a biocompatible device no larger than one cubic centimeter in size, roughly the volume of two nickels stacked back to back.

The program, Neural Engineering System Design (NESD), stands to dramatically enhance research capabilities in neurotechnology and provide a foundation for new therapies.

"Today’s best brain-computer interface systems are like two supercomputers trying to talk to each other using an old 300-baud modem. Imagine what will become possible when we upgrade our tools to really open the channel between the human brain and modern electronics."

“Today’s best brain-computer interface systems are like two supercomputers trying to talk to each other using an old 300-baud modem,” said Phillip Alvelda, the NESD program manager. “Imagine what will become possible when we upgrade our tools to really open the channel between the human brain and modern electronics.” Alvelda is featured in a recent video below.

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Among the NESD's potential applications are devices that could compensate for deficits in sight or hearing by feeding digital auditory or visual information into the brain at a resolution and experiential quality far higher than is possible with current technology.

Neural interfaces currently approved for human use squeeze a tremendous amount of information through just 100 channels, with each channel aggregating signals from tens of thousands of neurons at a time. The result is noisy and imprecise. In contrast, the NESD program aims to develop systems that can communicate clearly and individually with any of up to one million neurons in a given region of the brain.

Achieving the program’s ambitious goals and ensuring that the envisioned devices will have the potential to be practical outside of a research setting will require integrated breakthroughs across numerous disciplines including neuroscience, synthetic biology, low-power electronics, photonics, medical device packaging and manufacturing, systems engineering, and clinical testing.

In addition to the program’s hardware challenges, NESD researchers will be required to develop advanced mathematical and neuro-computation techniques to first transcode high-definition sensory information between electronic and cortical neuron representations and then compress and represent those data with minimal loss of fidelity and functionality.

SOURCE  DARPA

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 Brain Implants  

Researchers at Case Western Reserve University and University of Kansas Medical Center have restored behavior using a neural prosthesis in a brain-injured rat. This study provides strong evidence that brain-machine interfaces can be used to bridge damaged neural pathways functionally and promote recovery after brain injury.

R esearchers from Case Western Reserve University and University of Kansas Medical Center have restored behavior—in this case, the ability to reach through a narrow opening and grasp food—using a neural prosthesis in a rat model of brain injury.

The team's ultimate goal is to develop a device that rapidly and substantially improves function after brain injury in humans. There is no such commercial treatment for the 1.5 million Americans, including soldiers in Afghanistan and Iraq, who suffer traumatic brain injuries (TBI), or the nearly 800,000 stroke victims who suffer weakness or paralysis in the United States, annually.

The prosthesis, called a brain-machine-brain interface, is a closed-loop microelectronic system that records signals from one part of the brain, processes them in real time, and then bridges the injury by stimulating a second part of the brain that had lost connectivity.

Their work is published online this week in the science journal Proceedings of the National Academy of Sciences (PNAS).

“If you use the device to couple activity from one part of the brain to another, is it possible to induce recovery from TBI? That’s the core of this investigation,” said Pedram Mohseni, professor of electrical engineering and computer science at Case Western Reserve, who built the brain prosthesis.

Related articles Researchers Rewire Paralyzed Monkey To Control Arm Directly From The Brain  Miguel Nicolelis Explains Brain-to-Brain Interfaces  Prosthetics Becoming More Advanced With Control and Direct Sensory Feedback

“We found that, yes, it is possible to use a closed-loop neural prosthesis to facilitate repair of a brain injury,” he said.

The researchers tested the prosthesis in a rat model of brain injury in the laboratory of Randolph J. Nudo, professor of molecular and integrative physiology at the University of Kansas. Nudo mapped the rat’s brain and developed the model in which anterior and posterior parts of the brain that control the rat’s forelimbs are disconnected.

Atop each animal’s head, the brain-machine-brain interface is a microchip on a circuit board smaller than a quarter connected to microelectrodes implanted in the two brain regions.

The device amplifies signals, which are called neural action potentials and produced by the neurons in the anterior of the brain. An algorithm separates these signals, recorded as brain spike activity, from noise and other artifacts. With each spike detected, the microchip sends a pulse of electric current to stimulate neurons in the posterior part of the brain, artificially connecting the two brain regions.

Two weeks after the prosthesis had been implanted and run continuously, the rat models using the full closed-loop system had recovered nearly all function lost due to injury, successfully retrieving a food pellet close to 70 percent of the time, or as well as normal, uninjured rats. Rat models that received random stimuli from the device retrieved less than half the pellets and those that received no stimuli retrieved about a quarter of them.

“A question still to be answered is must the implant be left in place for life?” Mohseni said. “Or can it be removed after two months or six months, if and when new connections have been formed in the brain?”

Brain studies have shown that, during periods of growth, neurons that regularly communicate with each other develop and solidify connections.

Mohseni and Nudo said they need more systematic studies to determine what happens in the brain that leads to restoration of function. They also want to determine if there is an optimal time window after injury in which they must implant the device in order to restore function.

“This technology could have direct clinical application for restoring neural communication in the brain, and thus, for restoring function,” Nudo explained to KurzweilAI in an email interview. “Initial clinical targets will include focal stroke or traumatic brain injury (TBI) for motor impairments.

Presumably if functions can be restored with such a neural prosthetic, in the future functionality may also be augmented with an implant.

SOURCE  Case Western Reserve University

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Disabilities such as epilepsy, depression, obsessive-compulsive disorder, and even Parkinson’s disease are being treated with neuroimplants. Other scientists are working to substitute hearing for sight in blind people, and still others want to solve blindness entirely by implanting cameras in the brain.

In the embedded Techwise Conversation podcast below, Steve Cherry talks with neurosurgeon and hacker Dr. Richard Bucholz about the recent developments in brain-computer interfaces. 

Dr. Bucholz has the K. R. Smith Endowed Chair in Neurosurgery at the St. Louis University School of Medicine. In 2004, he won a Missouri Inventor of the Year award for using computer technology to make surgical procedures more effective and accurate. He is also a leading participant in the Human Connectome Project, a $30 million National Institutes of Health initiative to map the human brain. 

spectrum.ieee.org/podcast/at-work/innovation/fixing-the-brain-with-computers

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