On May 26, Beijing time, Neuralink, a brain-computer interface company co-founded by Elon Musk, announced a significant development: the company has been approved by the US Food and Drug Administration (FDA). That means they can start doing clinical trials in humans.
Previously, Neuralink had tried implanting brain-computer interface chips in the brains of mice, pigs and monkeys, and yes, after punching holes. To hit people's heads, they must go through layers of review by scientists.
The FDA does this, mainly evaluating food, drugs, medical devices and other products:
Safety: Products must prove harmless to humans or risk controllable in a series of laboratory tests and clinical trials.
Effectiveness: The product must be able to perform its claimed function and be supported by scientific evidence.
Balance of risk and benefit: The potential benefits of a product must outweigh its potential risks.
Previously, according to Reuters, the FDA pointed out that Neuralink wants to do clinical trials in humans, and must focus on solving these problems: will the device's lithium battery and implant wires move in the brain? How challenging is it to safely remove a device without damaging brain tissue?
For now, Neuralink said on Twitter that it has not yet begun recruiting patients for clinical trials, and more news will be announced soon.
Image source: Screenshot of Neuralink press conference, edited after editing
In this article, we will discuss:
What is a brain-computer interface?
What has Neuralink experienced since its inception in 2016?
What is the difference between Neuralink's high-performance brain-computer interface technology and traditional solutions?
What is the significance of the FDA's approval?
What is a brain-computer interface?
The brain's processing of information relies on the transmission of electrical signals between neurons. So, if something can read or write this electrical signal, the brain can interact directly with the machine! This is the brain-computer interface that we're going to talk about next.
Brain-computer interfaces are not a distant technology, and have long been used in daily life. It is divided into two types: invasive and non-invasive.
Among them, non-invasive brain-computer interfaces, small devices like hats, are common in departments such as neurological or motor rehabilitation in hospitals.
Non-invasive brain-computer interfaces are common in hospitals丨Wikipedia
It detects brain signals through wearable devices. But because the signal travels through the skull, the recorded brain signal resolution is not high.
Neuralink uses an invasive protocol that implants flexible electrodes directly into the cerebral cortex. In general, the deeper and closer to the brain tissue itself, the clearer and more accurate the EEG signal becomes.
But invasive solutions, after all, implant foreign objects into the brain, which can easily cause an immune response, and the human body may create scar tissue between electrodes and nerve tissue, resulting in a decline in signal transmission or even disappearance. Therefore, the results of this human test are indeed worth looking forward to.
For this moment, Neuralink has been working for seven years
In 2016, Musk and several other co-founders founded Neuralink.
In July 2019, Neuralink unveiled a prototype of its project, in which they built a "hole punch" that uses a laser to make tiny holes in the skull, and a "sewing machine" that implants a "thread" that is only a quarter of the thickness of a human hair. These lines are called electrical levels and can collect multichannel neural information.
They also showed experiments on animals, with a mouse holding a USB-C port about the size of its head, telling people that brain-computer interfaces are at least no longer crazy.
In August 2020, the company made the brain-computer interface chip N1, which is only the size of a coin. This time, the device was implanted on the surface of the brain of a live pig, successfully showing the brain activity of the pig. The top of the pig's head is smooth and smooth, and the brain-computer interface device is still in the form of wireless connection, with wireless signal transmission and wireless charging functions. The N1 is highly compact, integrated.
In April 2021, Neuralink's experimental monkeys converted brain waves into computer instructions and played a game of "mind ping-pong." The Neuralink device effectively reads the brain's information about movement control to control the movement of the ping-pong ball on the screen.
This means that the device has effectively completed specific tasks on animals, ready for future human-based brain-computer interface experiments.
In December 2022, Musk showed a monkey that can "mind type" — it typed two complete sentences. While the monkeys simply followed human cues and converted brain signals into cursor movements to pick the right sentences, rather than actually learning to spell human language, the demonstration confirmed that Neuralink's brain-computer interface went a step further in its usefulness.
It was also at this press conference that Musk announced that their device will be implanted in the human brain within six months, and has submitted all the documents required to the FDA to begin human trials. Now it seems that Musk is quite punctual.
Why is this FDA approval significant?
This is a major breakthrough in high-performance brain-computer technology for clinical applications.
Previously approved traditional implantable brain-computer interfaces, using a rigid electrode called a "Utah array," may cause rejection of foreign bodies inside the brain. It must be mentioned that this technology can only collect and transmit the neural information of 96 electrode channels.
For the Utah array, if more channels of neural information are needed, more electrodes need to be placed inside the brain, which is often undesirable.
The Neuralink device uses flexible electrodes to effectively reduce the brain's rejection response, and has 1024 channels of electrodes, which can collect very high-quality neural information.
In order to achieve a variety of complex brain-computer interface tasks, high-quality neural information is a prerequisite.
Neuralink has also developed a robot that can perform brain-computer interface surgery and safely remove devices without damaging brain tissue as much as possible. In this way, people can upgrade and iterate on the product they have in mind.
What is the social significance?
Let the blind "restore" their vision and let the paralyzed "move", Musk believes that this is the earliest application and help that Neuralink can carry out for humans.
Neuralink says that even people who are congenitally blind have "the visual part of the cerebral cortex still there."
The first generation of Neuralink technology used 1,024 channels of electrodes, but the company also demonstrated a next-generation model with more than 16,000 channels. According to Neuralink, placing a device on each side of the blind cerebral cortex, the blind person can see an image showing 32,000 "points of light". In other words, blind people can see more detailed, more "high-fidelity" images.
Image credit: Unsplash
In addition, using mind typing, establishing direct access between the brain and the computer (or mobile phone), helps quadriplegic people gain a kind of "digital freedom". But Neuralink isn't resting on its laurels. They also expressed confidence in restoring motor function to people with spinal cord injuries.
When an able-bodied person touches an object, sensation travels along the spinal cord into the brain, but in people with spinal cord injuries, this pathway is switched, and Neuralink hopes to implant electrodes into the spinal cord to stimulate neurons in the spinal cord and restore their ability to convey motor information, which in turn causes the muscles to contract.
Neuralink shows a pig with implants in its spinal cord. The principle is to intercept the brain's motor instructions and divert them to the legs to achieve the target action. Similarly, sensory signals from the limbs can be sent back to the brain so that the brain knows what's going on and simulates body movements.
At present, there are three that have entered the stage of human clinical trials
At present, there are three international implantable brain-computer interface companies that have entered the human clinical trial stage, namely Neuralink, Onward and Synchron.
The technical routes of these three companies are also different.
Neuralink belongs to the "cortical piercing" route.
Onward focuses on restoring post-traumatic neurological function, such as using brain-computer interfaces to restore the ability to walk after a spinal cord injury. It uses an electrode called electrocorticography (ECoG), which is placed on the surface of the cerebral cortex to collect nerve signals. Onward takes the "cortical surface" route, and there are also micro-spiritual medical treatments in China who take this route.
Weiling Medical is the only work and team in China that does high-density flexible electrode implantable brain-computer interface on the surface of the cortex, and is expected to complete the clinical testing and verification of the electrode array by the end of this year.
The Synchron technique is minimally invasive, using a vascular stent-like electrode placed inside a blood vessel vessel in the brain to pick up nerve signals near the blood vessel. It belongs to the "vascular interventional type".
Image credit: Unsplash
It is worth mentioning that Synchron has been approved by the FDA in 2021, began trials, and announced the first implantation of a brain-computer interface in the United States in July 2022.
The technique used by Synchron is to place electrodes close to the inside of blood vessels in the brain, which can only collect a fairly limited number of neural signals due to technical limitations. As a result, the system can currently only perform very rudimentary and simple tasks. Moreover, subjects learn new tasks through the system, which requires a lot of training time.
If we compare the brain to a 1-kilometer road, we have only walked 5 centimeters
At present, the application direction of brain-computer interfaces is to replace damaged organs, such as:
Paralyzed patients use EEG to control the robotic arm to take objects, that is, to process the output of brain information;
Or without passing through the limbs and facial features, directly through the brain to transmit and receive information to the machine, that is, processing the input and output of brain information.
Brain-computer interfaces may also be able to match brain nerves and machinery, or replace consciousness between living organisms, but this is still in the very distant future.
To achieve the ultimate brain-computer interface, it is necessary to make every neuron in the brain "seamlessly connected" with the outside world, which means that humans need to clearly understand the characteristics of each neuron.
But at present, human understanding of the brain is still stuck in the cortical division that controls movement and controls visual hearing, which is very superficial.
A brain scientist once compared all that is known about the brain to a kilometer-long road, and we currently travel less than five centimeters.
How far brain-computer interfaces can go depends on basic research in brain science.
By Jayden, Ruiyue, Shen Zhihan, ChatGPT
Edit: BIU
Unless otherwise specified, the source is Neuralink