According to the China Academy of Information and Communications Technology, noninvasive systems — such as wearable EEG headsets — currently account for more than 80 percent of China's BCI market. Because they require no surgery, companies are already monetizing these devices, rolling out products ranging from neuro-feedback headbands for gamers and students, to advanced sleep-monitoring systems.

　　Yet, beneath the soaring valuations, sobering technical and ethical hurdles remain.

　　For implantable devices, the human body's immune system is a formidable opponent. Over time, the body forms scar tissue around implanted electrodes, which can degrade signal quality.

　　Data scarcity is another major bottleneck. Unlike generative AI models that are trained on billions of readily available internet texts, BCI algorithms require highly sensitive neural data, which is exceedingly difficult and expensive to collect.

　　Then there is the issue of cognitive privacy. Recognizing the profound ethical implications of "reading minds", China's Ministry of Science and Technology issued the country's first national ethical guidelines for BCI research in February 2024, ensuring the technology remains "tech for good" and prioritizing patient autonomy.

　　"The approval of the first product is just the beginning," noted Hong of Tsinghua University. Scientists are still grappling with deep biological mysteries, such as how these interfaces interact with the brain's natural plasticity, and whether they can actually help heal the nervous system rather than just act as a high-tech crutch.

　　For now, medical rehabilitation will be the industry's most viable cash cow. But the ultimate ceiling of the BCI market remains unknown.