China’s tech drive to control machines using brain signals

(By Caixin journalists Xu Luyi and Kelly Wang)

In 2023, a 55-year-old man surnamed Yang became the first person in China to undergo semi-invasive brain-computer interface (BCI) surgery, an emerging technology that allows him to control devices using his brain signals. Afterwards, Yang, who is paralysed, was able to use his thoughts to direct a robotic arm that can grip and move items.

The concept of BCI was first proposed over half a century ago by American professor Jacques Vidal, who envisioned direct brain-machine communication through the analysis of the brain’s electric activity.

Vidal’s vision has since become a clinical reality. The technology has been used to treat patients with consciousness disorders, language disabilities, and paralysed individuals.

In 2023, the value of the global BCI market reached US$2.35 billion and is expected to exceed US$10 billion by 2033, growing at a pace of more than 16% annually, according to a May report from Precedence Research.

In recent years, BCI research has advanced rapidly in China, with its clinical applications in certain areas standing at the cutting edge globally.

As China is increasingly emphasising scientific and technological development as key to its economy’s long-term growth, BCI has been identified as a promising field. In February, the Ministry of Science and Technology issued ethical guidelines for BCI research while the Ministry of Industry and Information Technology released a plan in July that outlined plans to create standards for the use of BCI technologies.

BCI devices can be roughly sorted into three categories, depending on how they access the brain’s electrical signals — non-invasive, invasive and interventional.

The non-invasive approach in which electrodes are attached to the scalp currently dominates the BCI market, accounting for 85.94% of the market revenue in 2023, according to a recent report released by consulting firm Grand View Research.

However, while this approach is less risky, it is generally less effective at reading signals from the brain, which can be distorted as they pass through the skull.

“An invasive BCI is like watching the game from the front row VIP section, while a non-invasive one is like standing outside the stadium just hearing the sounds,” said Xu Minpeng, vice dean of the Academy of Medical Engineering and Translational Medicine at Tianjin University.

Xu, named one of the “Innovators under 35” by the MIT Technology Review in 2022, has led several breakthroughs in BCI development. In 2018, he developed a novel technique for detecting electroencephalogram (EEG) signals — which are produced by electrical activity in the brain — as small as 0.5 microvolts. This breakthrough in detecting weaker EEG signals allows further insight into how the brain works and enables more tasks to be completed by BCI devices.

In 2023, Xu’s team at Tianjin University released a high-speed BCI system able to respond to up to 216 commands, securing multiple invention patents in China and the US. Earlier this year, they released the open-source software platform Meta BCI, providing pre-built tools, algorithm libraries and signal processing modules.

To let users watch the game “from the front row”, more intrusive BCI methods implant electrodes directly onto their brain.

In 1969, Eberhard Fetz, a neuroscientist at the University of Washington, used tungsten microelectrodes to penetrate the cerebral cortex of monkeys and record neuronal activity.

China’s first venture into the clinical application of invasive BCI came in 2020, when a team at Zhejiang University implanted electrodes into a paralysed man, allowing him to feed himself using a robotic arm.

Earlier this year, a team at the Chinese Institute for Brain Research in Beijing revealed it had implanted a device into a monkey’s brain, which could control a two-dimensional cursor. The team is preparing for human trials involving patients with motor disorders.

Trials of invasive BCI technology involving human subjects are still “in the early stages”, a neurosurgeon noted, emphasising the complexity of neurosurgery and the long-term risks associated with implanting objects directly into the brain.

Scholars have expressed safety concerns over the brain’s sensitivity to infections and its limited capacity for self-repair. Even minor injuries can lead to cognitive, sensory or motor issues, they told Caixin.

Neuralink, a BCI company founded by Elon Musk, disclosed in 2022 that some of the monkeys used to test its invasive BCI prototypes had been euthanised. The Physicians Committee for Responsible Medicine claimed that the monkeys suffered from swelling in the brain, chronic infections, paralysis and seizures after the implantation, in a letter submitted to the US Securities and Exchange Commission in 2023.

Musk denied reports that the monkeys died because of their Neuralink implants, claiming the tests were done on “terminal” primates in a post on X.

After adjustments were made to improve precision and reduce risks, Neuralink received approval for human trials in May 2023 and implanted the first device into a human in January this year. Following a brief period of success, only about 15% of the electrodes continued to function normally, as the cerebral cortex can shift over time and cause difficulty for signal collection.

Despite the risks, the invasive BCI segment is expected to witness “lucrative growth” by 2030, the Grand View Research report said, noting the technology’s ability to help paralysed individuals through brain-controlled robotic limbs and restore vision by connecting the brain to an external camera.

Progress is also being made on the semi-invasive track, in which electrodes are placed on the membranes between the skull and the cerebral cortex. Proponents of this technology argue it gathers the brain’s signals more precisely than non-invasive devices while being less risky than fully invasive devices.

Yang, who was paralysed after a spinal cord injury 15 years ago, had a semi-invasive device implanted in October 2023 by a team led by Professor Hong Bo at Tsinghua University’s biomedical engineering department.

Yang has since undergone hundreds of rehabilitation sessions and is able to grip and move a bottle using a robotic arm by imagining moving his hand. He also regained some of his sensory feelings at the beginning of the year, with the back of his hand able to sense temperature.

Hong explained that this suggests that his nervous system has been restored to some extent, likely due to Yang’s brain adapting to the device.

A second patient who received the same semi-invasive BCI surgery successfully completed a test at high altitude during an August flight.

The only team advancing alongside Hong’s team globally is a research group from the Swiss Federal Institute of Technology Lausanne. In May 2023, the team stated they designed a device connecting the brain and spinal cord, enabling a paralysed man to stand and walk. However, the device was removed from the patient after five months due to infection concerns.

As an alternative to invasive methods, some scientists have explored so-called “interventional” devices, in which electrodes are attached to the brain’s blood vessel walls through a catheter that is inserted through the jugular vein. A signal receiver is placed near the patient’s clavicle, without having to open the skull.

This kind of device is safer to both insert and remove compared with both invasive and non-invasive devices implanted inside the skull, but can also capture clearer and stronger neural signals compared to non-invasive devices.

In China, a team led by Professor Duan Feng from Nankai University’s College of Artificial Intelligence conducted the country’s first interventional BCI experiment on an animal, a sheep, in June 2022, before performing another test on a monkey less than a year later.

The monkey was able to control a mechanical arm with its mind through the technology. To date, no health issues such as infections or bleeding have been observed in the monkey, a lab member told Caixin, adding that the brainwave signals collected remain clear. Duan said the team is working towards clinical trials in humans.

Synchron, a US-based BCI company, received clinical trial approval for its interventional project in Australia in 2021. Preliminary clinical results showed good signal stability after device implantation, allowing a patient to control digital devices with their mind. During a 12-month follow-up period of the first human trial, no serious adverse events related to the device were reported.

This article was first published in Chinese by Caixin Global as “In Depth: China’s Drive to Develop the Tech to Move Machines With Thoughts Alone”. Caixin Global is one of the most respected sources for macroeconomic, financial and business news and information about China.

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