Working backward, a brain-computer interface returns a sense of touch after complete spinal cord injury

Leti’s space quantum sensor.
Years of data showed that imperceptible nerve signals still reached the motor cortex, and could be amplified through the brain-computer interface to provide conscious touch perceptions. (Pixabay)

Researchers at Battelle and Ohio State University have developed a brain-computer interface that not only allows a paralyzed person to move their hand but also to regain a sense of touch.

Battelle has been collaborating with the university’s Wexner Medical Center on this project for years; the company’s NeuroLife program aims to build neural bypass technology that can reconnect the brain with muscles previously cut off by a severe spinal cord injury or other nerve damage.

One study participant, Ian Burkhart, has lived with paralysis in his hands and feet for the past decade. In 2014, the university’s surgeons implanted a microchip about 4 millimeters square within the area of his brain governing voluntary movement. The chip transmits data to a computer and arm cuff lined with electrodes that stimulate and help move specific muscles.

At the time, the researchers didn’t know the system could work in reverse, in a way, according to Patrick Ganzer, principal research scientist at Battelle. “Furthermore, Ian has a very severe [spinal cord injury] that should essentially block hand touch signals from even reaching the brain,” Ganzer added.

But an analysis of years of data from the project revealed that small, imperceptible nerve signals still reached Burkhart’s motor cortex. Researchers showed these weak signals of touch could be picked up in the brain, rerouted and amplified through the computer interface to a wearable haptic system.

“It has been amazing to see the possibilities of sensory information coming from a device that was originally created to only allow me to control my hand in a one-way direction,” said Burkhart, whose dexterity has improved since regaining simple touch sensations.

The teams’ findings were published in the journal Cell, which showed that the brain-computer interface could measure the intensity of the hand’s grip and transform it into conscious perception in real-time—allowing Burkhart to pick up and move objects using the right amount of pressure.