In reality, the brain-computer interface is connected to your brain at one end, extracting your ideas from the dense and complex neuronal electrical signals, and connected to external devices such as computers or machinery at the other end, directly bypassing your body to turn ideas into control signals and further execute commands. It does not need to rely on the peripheral nerves and muscle systems of your limbs to directly establish direct information exchange between the brain center and external devices. Musk released a monkey for experiment in 2021. The monkey typed a line of words "I want to eat snacks" on the computer through mind operation. This is supported by brain-computer interface technology. The cochlear implant that helps the disabled to obtain sound is the most successful and most popular technology for brain-computer interface so far. Its principle is to convert sound signals into electrical signals and transmit them directly to the brain, which can help a large number of deaf people regain the ability to sound and communicate. Characters in movies such as Avatar or Iron Man all use brain-computer interface technology to flexibly operate limbs, which is not yet possible. In recent years, after years of development by scientific research teams at home and abroad, brain-computer interfaces have made a lot of progress. At present, they are divided into three major technical paths: invasive, semi-invasive and non-invasive. Among them, the invasive method has the highest risk factor.

Neuralink adopts an invasive solution, which requires a craniotomy to implant a chip in the human cortex. After the chip reads and analyzes your brain waves, it transmits these signals. According to the Neuralink official website, the implant "N1" is the size of 5 coins stacked together, and its structure includes: biocompatible shell, battery, chip and electronic devices, and 64 wires. The built-in micro-battery of "N1" is equipped with a pocket-sized inductive charger that supports external wireless charging. In addition, there are 1024 electrodes distributed on the 64 threads of N1, which can record neural activity and are extremely flexible. It is worth mentioning that in the Neuralink plan, the implantation operation is not performed by a human doctor, but by the robot "R1". During the implantation process, a piece of the patient's skull was removed and replaced by a brain-computer interface. After the implant is complete, the brain-computer interface device will read and analyze brain activity and transmit the information wirelessly to a nearby laptop or tablet.

In early 2022, the FDA rejected the company's clinical application based on safety and other factors. The FDA is concerned that the tiny wires carrying the electrodes of the device may migrate to other areas of the brain; the FDA also raised questions about whether the device can be removed without damaging brain tissue, and whether the device may overheat and damage brain tissue. A series of safety issues. Previously, BrainGate, a company that does invasive brain-computer interfaces, had encountered a situation where the electrodes were scrapped in the brain. The reason is that the electrodes were entangled by glial cells. Therefore, the FDA's consideration of safety is a realistic problem that everyone has to face.

Today, Neuralink has successfully obtained human clinical approval and completed the first patient implant, which may mean that more evidence has been obtained in terms of safety and other aspects. Of course, it may also be that Musk has compromised. Previously, the FDA believed that a slower phased trial would be more suitable for Neuralin, that is, fewer subjects were implanted initially, and more tests were conducted a few months later. Musk was dissatisfied with this suggestion because it might delay the progress of the FDA's final approval. But now, the ALS patient recruitment plan released on Neuralink's official website shows that Neuralink hopes that the subjects will be over 22 years old and meet the requirements of limited limb function, no improvement for more than one year, and at least one relative or friend around to provide care. The entire trial lasts for 6 years, including 18 months of basic research.

And Neuralink said that 11 surgeries will be performed in 2024, 27 in 2025, and 79 in 2026, and by 2030, this number will grow to 22,000. This is also in line with the FDA's slower, phased recommendations. Neuralink's first brain-computer interface product is called Telepathy, and Musk also wrote down his thoughts on the product's prospects: "(Future humans) only need to think to control mobile phones or computers, and control almost any device through them. Imagine if Hawking could communicate faster than a fast typist or auctioneer, this is our goal. ”
Compared to the so-called turning humans into cyborgs, this goal is obviously much more practical and has taken a key step.

Musk is a controversial figure, and every innovation of his will trigger heated discussions. Some people worship him as the savior of the technology industry, while others criticize him as a reckless dreamer. But it is undeniable that his vision and execution have pushed the boundaries of technology many times. As John Donohue, a brain-computer interface expert at Brown University in the United States, said, "Musk has done a lot of preliminary work based on the research of many scientists, including the work our team has been doing since the early 21st century. "Since 1969, scientists have been working hard to advance the experiments of external connection of the nervous system and explore the mysteries of the human brain. The brain-computer interface creates a connection path for information exchange between the human brain and external devices. What can this bring us? The scene depends on imagination. At least in the medical field, it has many exciting uses. Many human diseases are caused by the inability of the brain to connect to the nerves around the body, such as epilepsy and Parkinson's disease, and quadriplegia after spinal cord nerve injury. Based on brain-computer interfaces, these diseases are expected to be improved.

Current drugs and surgical technologies lack sufficient therapeutic effects for patients with central nervous system damage caused by stroke, ALS, etc. Patients are in a state of dysfunction such as paralysis for a long time and have poor quality of life. The technology of brain-computer interface breaks through the scope of traditional body tissue repair and uses human-machine The method has achieved functional replacement, which is of revolutionary significance, and has also made breakthroughs in some cases. At the opening ceremony of the 2014 Brazil World Cup, a young man with high paraplegia, wearing a mechanical aid, used the brain-computer interface to kick the first ball, showing the world the most intuitive clinical value of the brain-computer interface-providing auxiliary tools for movement disorders. Companies including Neuralink are proving this. Domestic research on brain-computer interfaces is also in full swing. In 2020, a team from Zhejiang University enabled a quadriplegic to accurately control external robotic arms and hands, and to accurately complete basic movements such as eating and shaking hands. In addition to advances in sports-assisted therapy, brain-computer interface technology in the field of language recovery has also shined.

In June 2023, Huashan Hospital Affiliated to Fudan University took the lead in releasing a patent for Chinese The neural network model of Chinese language can decode the lexical tones and basic syllables of Chinese from the intracranial recordings respectively and combine them to generate speech. Through brain-computer interface technology, patients with tonal language pronunciation disorders or aphasia can directly express their "voices of the heart". It can be said that the starting point of the application of brain-computer interface is medicine. The use of brain-computer interface technology to obtain and analyze the information of the above-mentioned brain functional areas can open a new era of treatment for many patients. Although brain-computer interface still has a long way to go from clinical to final market launch, and many problems such as the safety, stability, and reliability of equipment and surgery (invasive) need to be solved, many people with stroke paralysis and Parkinson's disease need brain-computer interface technology to restore their functions. The demand for the application of brain-computer interface in medical treatment is urgent and broad. According to McKinsey's estimates, between 2030 and 2040, the global medical use of brain-computer interface will reach 400 million units. The potential market size of medical applications is expected to reach 40 billion to 145 billion US dollars, of which the potential size of serious medical applications is 15 billion to 85 billion US dollars, and the potential size of consumer medical applications is 25 billion to 60 billion US dollars.

At present, the exploration of consumer medical care is also hot. For example, a Canadian brain-computer interface company has launched a brain wave detection headband to help users improve meditation effects through real-time audio feedback. In China, there are also products such as brain-controlled sleep aids, brain-controlled mice, and meditation brain state monitoring to improve insomnia and depression. For example, Airdream, a miniaturized EEG monitoring device released by Rouling Technology, not only monitors sleep quality through EEG signals, but also carries a home sleep EEG management system to assist users in decompressing, relaxing, and quickly entering a sleep state; Hangzhou Huiche Technology launched an EEG smart eye mask.

In general, brain-computer interface devices can only act on the cerebral cortex at present, which can simplify many issues involved in in-depth research. The cerebral cortex mainly processes many direct signals, such as sensory information, hearing, and vision directly from motor intentions.
In theory, this can solve many problems such as blindness, paralysis, and hearing, and only requires the device to be correctly connected to the cerebral cortex. According to Musk, Neuralink has now entered the brain about 3 to 4 mm deep. These electrodes sense from multiple levels within the cortex. There are deeper brain systems below the cerebral cortex, such as the hypothalamus. These deeper brain systems are the goal of achieving information interaction. It can also treat depression, addiction, anxiety and more diseases.
This requires a lot of scientific research input and output, and there is still a long way to go.

If the ultimate goal of AI is to achieve the ultimate in inorganic life intelligence, then what brain-computer interfaces do is to break the information boundary between organic life intelligence and inorganic intelligence and achieve fusion. Regarding brain-computer interfaces, countless people have given application scenarios, such as exchanging opinions and controlling emotions. In the short term, it is too overestimated, and in the long term, it is too underestimated.

Musk once said that he wanted to restore the sight of the blind and restore the mobility of the disabled, and even talked about the integration of humans and artificial intelligence. This also made brain-computer interfaces widely popular. But in fact, "let the blind see, let the paralyzed move, and let the deaf hear again" is an old saying that has been circulating for 25 years. And countless scientists are working towards this ultimate goal. The current problem is that restoring sensory input (such as vision) involves electrical stimulation in the brain, which is completely different from just recording single-cell neural activity. At present, there is no evidence that current neural implant devices can create sensory systems in any way. In other words, as an emerging research field, brain-computer interface technology is still in its early stages of development, involving computer science, neuroscience, psychological cognitive science, biomedical engineering, mathematics, signal processing, clinical medicine, automatic control and other fields, and there are still a lot of problems to be solved.

For example, how to deal with a large number of complex neurons. Brain-computer interfaces can come in many different types and are used to provide a variety of functions. But all scientists studying brain-computer interfaces are working hard to solve these two problems: How to output the right information from the brain? How to input the right information into the brain? These two things happen naturally in your brain all the time. As you read this sentence, your eyes are making a series of specific horizontal movements. This is the brain neurons outputting information to a machine (your eyes), and the machine receives commands and responds. Inputting and outputting information is the job of brain neurons. What brain-computer interfaces need to do is to intervene in this process. This doesn't sound difficult. However, the volume of the entire cerebral cortex is about 500,000 cubic millimeters, and there are about 20 billion neuronal cell bodies in this space. Each cubic millimeter of cortex contains an average of about 40,000 neurons. But neuronal cell bodies are only a small part of the structure of neurons. In addition, there are glial cells and blood vessels in the brain that are about the same number as neurons. The total length of capillaries in each cubic millimeter of cortex can reach one meter.

If the technical engineers of brain-computer interfaces want to capture or feedback brain signals extremely accurately, they need to capture the signals emitted by specific neuronal cell bodies in this cubic millimeter area, or stimulate certain specific cell bodies to emit the signals required by engineers. The difficulty can be seen from this. Compared with non-invasive, invasive brain-computer interfaces can better receive neuronal signals, but cables are required to transmit large amounts of data. In addition, the greater difficulty in engineering also includes cost control, whether it can be commercialized by reducing costs through reasonable processes and processes. For example, Moore's Law on brain-computer interfaces. According to statistics, with the current brain-computer interface technology doubling the number of neurons that can be recorded simultaneously in an average of 7.4 years, it will take until 2100 to record 1 million neurons at the same time, and it will take until 2225 to record all neurons in the human brain.

Therefore, how brain-computer interfaces solve the bandwidth problem has become a key point for academic research and industrial breakthroughs. Donohue said that regarding the huge amount of data, the solution proposed by Neuralink is more practical than imagined. Instead of pursuing full-bandwidth, high-speed information acquisition methods, Neuralink uses Bluetooth. The amount of information that can be obtained in this way is small. Due to bandwidth limitations, the amount of information taken out of the brain in this way cannot separate the activity of each neuron. But it is effective, and this method is enough to achieve the goal of controlling computers with neural activity.
In addition, how to improve the accuracy of signal recognition and how to improve signal processing methods to make them systematic and universal are also problems that need to be solved.

Of course, these technical problems are being overcome one by one by scientists and engineers. A technology needs to go a long way from its initial invention to terminal application. It is not only a technical issue, but also involves the participation of humanistic ethics and philosophy. After all, humanities without science are ignorant, and science without humanities is dangerous. When a person's brain consciousness can be accurately read, it means that the rich privacy data in the brain may be leaked or stolen. With the development of brain-computer interface technology, in the future, it will undoubtedly be necessary to provide sufficiently secure measures to protect the privacy of users' data. "For me, the brain is a safe place for freedom of thought, fantasy and dissent. Without any protection, we are close to crossing the last privacy boundary." Nita Farahani, professor of neuroethics at Duke University in the United States, said.

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