A participant in the BrainGate clinical trial uses wireless transmitters that replace the cables normally used to transmit signals from sensors inside the brain. Credit: Braingate.org

Brain-computer interfaces (BCIs) are an emerging assistive technology, enabling people with paralysis to type on computer screens or manipulate robotic prostheses just by thinking about moving their own bodies.In an important step toward a fully implantable intracortical brain-computer interface system, BrainGate researchers demonstrated the first human use of a wireless transmitter capable of delivering high-bandwidth neural signals.

For years, investigational BCIs used in clinical trials have required cables to connect the sensing array in the brain to computers that decode the signals and use them to drive external devices.

The system is able to transmit brain signals at “single-neuron resolution and in full broadband fidelity”, say researchers at Brown University in the US.

A clinical trial of the BrainGate technology involved a small transmitter that connects to a person’s brain motor cortex.

Trial participants with paralysis used the system to control a tablet computer, the journal IEEE Transactions on Biomedical Engineering reports.

The participants were able to achieve similar typing speeds and point-and-click accuracy as they could with wired systems.

John Simeral, an assistant professor of engineering at Brown University: “We’ve demonstrated that this wireless system is functionally equivalent to the wired systems that have been the gold standard.

“The signals are recorded and transmitted with appropriately similar fidelity, which means we can use the same decoding algorithms we used with wired equipment.

“The only difference is that people no longer need to be physically tethered to our equipment, which opens up new possibilities in terms of how the system can be used.”

It marks the latest advance in the rapidly growing field of neural interface technologies, which has attracted the likes of Elon Musk and Facebook.

Mr Musk has recently revealed that his Neuralink startup has already tested a wireless chip on a monkey’s brain that allows it to play video games.

The two participants of the latest trial – aged 35 and 63 – are paralysed through spinal cord injuries. They were able to use the wireless system continuously for up to 24 hours while at home, rather than in a laboratory.

The relative ease of use meant trained carers were able to established the wireless connections, meaning the study could continue while the pandemic ruled out visits to the participants’ homes.

Leigh Hochberg, an engineering professor at Brown University and leader of the BrainGate clinical trial, says: “With this system, we’re able to look at brain activity, at home, over long periods in a way that was nearly impossible before.

“This will help us to design decoding algorithms that provide for the seamless, intuitive, reliable restoration of communication and mobility for people with paralysis.”