China has achieved a series of milestones in the field of brain-computer interface technology this year, notably in the clinical translation of invasive techniques, bringing new hope to patients with neurological disorders.

These developments signify that China is among the forerunners of this cutting-edge field, scientists said.

BCI technology is considered a revolutionary approach to addressing neurological function deficits. It works by decoding electrical signals in the brain and simulating the transmission of instructions, bypassing or bridging damaged neural pathways, according to the Institute of Automation at the Chinese Academy of Sciences.

"This technology is expected to be widely applied to severe motor or communication dysfunctions caused by conditions like ALS, paraplegia and spinal cord injuries, helping patients regain some level of daily functionality," said Cao Shenghao, a doctoral student at the institute.

For patients who have undergone amputations but still retain normal brain function, BCIs can transmit brain-generated motion commands to external devices such as computer cursors or robotic arms.

For those with spinal cord injuries, the technology aims to establish "information bridges" above and below the nerve breakpoints to restore command transmission.

Last month, a research team from Nankai University in Tianjin led the world's first interventional BCI trial to assist with the restoration of motor function in patients' affected limbs. It enabled a patient who had been paralyzed on the left side for six months due to a stroke to regain the capabilities of movement and take medication after the procedure.

Significant breakthroughs have also been made in interventions for speech disabilities. A project led by the Beijing Institute for Brain Research achieved the first clinical application of a wireless implanted Chinese language BCI system in the country.

In the trial, a patient who lost the ability to speak because of ALS was able to successfully express complete sentences like "I want a drink of water" and "I want to take a walk with my family" by having their brain signals decoded into language intentions.

Last month, the Center for Excellence in Brain Science and Intelligence Technology at the CAS announced that a man who lost all four limbs due to a high-voltage electricity accident had demonstrated proficiency in controlling chess pieces and racing games with his thoughts alone, just 2 to 3 weeks after a BCI device was implanted in March.

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His operational speed was close to that of normal people using a computer touch pad. This achievement made China only the second country in the world to successfully enter the clinical trial phase with invasive BCIs.

BCI technology pathways are diverse, comprising invasive, semi-invasive and noninvasive types. "Among them, invasive BCIs, which involve implanting electrodes directly into the cerebral cortex, can capture higher resolution and more stable neural signals," Cao said.

"They hold significant potential in neurorehabilitation but also face surgical risks and ethical challenges, representing the highest technical difficulty and regulatory requirements," he said.

Obtaining high-quality signals requires deep brain access, but the surgery itself can cause damage, he said.

"The goal of scientists in this field is to minimize such damage, and the most direct method is to reduce the size of the implantation window."

Cui Yue, an associate researcher at the Institute of Automation at the CAS, said rigid electrodes cannot accommodate the slight movements of brain tissue during physiological activities and can easily cause nerve drag and damage. In contrast, flexible electrodes, which are made of soft, adaptive materials, can move naturally with brain tissue, reducing damage and scarring, making them more suitable for long-term stable implantation.

Cui's team has reduced the implantation damage to 300 microns and replaced traditional rigid electrodes with flexible electrodes.

However, the extreme softness of flexible electrodes brings implantation challenges. To address this, the Institute of Automation has developed the "CyberSense" flexible micro-electrode implantation robot, pioneering a "sewing machine-style" automatic implantation technology.

"Just like threading a needle, we thread the flexible electrode wire into a fine needle and use the needle tip to precisely deliver the electrode to the designated brain area, then withdraw the needle, leaving only the electrode in place," Cui said.

The efficiency of reading brain signals is critical, directly impacting the accuracy and complexity of BCI tools.

Doctoral student Cao said that many factors affect the reading efficiency, including electrode materials and the number of collection channels.

These are key areas of focus for BCI scientists. Increasing the number of signal collection channels within the same volume of implant devices allows for more complete brain activity information to be restored, laying the foundation for subsequent functional implementation, Cao said.

"Breakthroughs in artificial intelligence technology have contributed greatly to the current development of BCIs," he said. "Even when dealing with the same segment of brain signals, AI now enables us to decode richer neural information than before."

BCIs not only serve clinical medical purposes but also have the potential to expand into everyday life applications in the future, according to Cao, such as providing sleep regulation, emotional monitoring and attention enhancement.

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"The current development stage of BCIs is still in its infancy, like a child just learning to walk, but it holds tremendous potential for breakthrough development in the future," he said.

Liu Zixuan contributed to this story.