How Thoughts Could Someday Control Electronic Prosthetics

For many years, Stanford researchers have been working towards an advance in technology that could one day help people with paralysis regain use of their limbs, and allow amputees to use their thoughts to control the wireless prostheses and to interact with computers.

The brain-computer interface is a device that is implanted beneath the skull on the surface of a patients brain (the cerebral cortex).  This implant allows the connection between the human nervous system and an electronic device that permits the patient to regain some control of their limbs, for instance, helping restore motor control to a person with a spinal cord injury.

 

The wireless brain-computer interface transmitter enables patients to control electronic devices with their thoughts. This is where the device would be positioned. Image Credit: Mindzilla

 

In the past, this technology could only be used by patients with the help of several lab assistants and techs that would operate various cables connecting bulky signal processors directly to a single port in the patient’s skull. The cumbersome and anchored nature of the technology made it completely impractical, and borderline inconceivable to ever become useful to patients outside of a lab setting.

Current devices record extensive amounts of neural activity, then transmit these brain signals through wires to a computer. But when researchers tried to use the same procedure for wireless brain-computer interfaces, it took so much power to transmit the data that the devices would overheat which would be far too dangerous for the patient.

A team led by electrical engineers and neuroscientists Krishna Shenoy, PhD, and Boris Murmann, PhD, and neurosurgeon and neuroscientist Jamie Henderson, MD, have shown that it’s possible to create a wireless device that transmits accurate neural signals. These wireless devices would look more natural than the wired models and would give patients a freer range of motion.

This new interface completely removes the tethered nature of the technology, by processing data inside a device roughly the size of a gas cap. A processor is located inside the device to amplify the spikes emitted by neutrons.

To test their idea, researchers collected neuronal data from three nonhuman primates and one human participant in a clinical trial.

 

In bypassing the injury and restoring communication between the brain and the relevant part of the spinal cord, the scientists successfully treated two rhesus monkeys each with one leg paralysed by a partial spinal cord lesion. Image Credit: Google

 

As the participants performed the movement tasks given, for instance, positioning a cursor on a computer screen , researchers took measurements. The findings validated their hypnosis that a wireless interface could accurately control an individual’s movement by recording a subset of action-specific brain signals.

The next step is to build an implant based on this new technology and proceed through a series of tests to achieve the ultimate goal.

Thumbnail Credit: https://www.technologyreview.com/2015/01/14/169635/a-brain-computer-interface-that-works-wirelessly/