The imagination of brain-computer interfaces in science fiction movies is coming to life.
More than 10 years ago, "Avatar" showed a scene in which a human warrior who entered a sleep pod could read consciousness through computer technology, transfer it to the clone's body, and use the latter to act. Many people have seen the charm of brain-computer interfaces. Nowadays, the technology of "inductive dialogue" between the human brain and the machine brain has come to people.
A few days ago, the Chinese scientific research team announced the success of the world's first clinical trial of wireless minimally invasive brain-computer interface: the team of Professor Hong Bo of Tsinghua University School of Medicine designed and developed the wireless minimally invasive implanted brain-computer interface NEO technology; Zhao Guoguang, President of Xuanwu Hospital of Capital Medical University, and Shan Yongzhi, Chief Physician, cooperated with Tsinghua University to conduct the first clinical implantation trial on October 24, 2023. After the operation, a patient with quadriplegia for 14 years was trained in home brain-computer interface** and realized brain control actions such as drinking water independently.
Brain-computer interfaces enable direct communication between the brain and the computer by recording and interpreting brain signals. "There is still a long way to go before true 'mind reading' can be achieved. Let's say it's a 100-page book of unknowns, and we're just turning the first page at the moment. Hong Bo said.
The picture shows the team of Zhao Guoguang, President of Xuanwu Hospital, performing the first implant operation. (*From Tsinghua University School of Medicine).
A different brain-computer interface scheme from Musk.
On January 29, Elon Musk, CEO of Tesla Inc. and CEO of SpaceX, announced that the brain-computer interface was "successfully operated", which also attracted attention at home and abroad.
Musk wrote on the social platform: "Yesterday (January 28), the first human patient underwent implant surgery from the company 'Neural Connection' and is currently recovering well. Preliminary results show that neuronal spike detection is promising. Musk named the first product "telepathy", when the brain is implanted with a device, it can control "almost all devices" such as mobile phones and computers with just the mind. "Imagine that Stephen Hawking might be able to communicate faster than a typist or auctioneer. That's what we're aiming for. Musk said.
The Musk team is a very respectable team. The technical routes for the development of brain-computer interfaces by the two teams are different. Hong Bo said.
According to him, the wireless minimally invasive implanted brain-computer interface NEO technology adopted by the Tsinghua team is to place electrodes on the epidural of the brain, which will not damage the nerve tissue, and complete the input and output of signals through the coupling of the internal and external machines. Musk's team uses a fully invasive brain-computer interface.
The signals of the brain can be divided into three levels from the inside to the outside: nerve cell discharge, intracranial EEG, and extrascalp brain waves collected by borrowing EEG caps. Hong Bo made an analogy: suppose there are 10 people sitting in a room, each person represents a nerve cell, and the information to receive nerve cells can be obtained through a "microphone", and the product of Musk's team is equivalent to placing a microphone in front of everyone, and the "radio" effect is good, but there are problems such as large "footprint" and high energy consumption; In the brainwave scheme of the scalp that is collected by borrowing an EEG cap, the microphone is placed outside the door, so the received signal will be very blurry and disturbed by a lot of noise.
Our solution is to place the electrodes outside the meninges, which is somewhere in between, which is equivalent to placing a microphone in the door to get information. Hong Bo said.
In Xuanwu Hospital, President Zhao Guoguang showed several major brain-computer interface products on the market to the reporter of China Youth Daily and China Youth Network. Among them, "scalp EEG" is a non-implantable brain-computer interface, which has the clinical advantage of being non-invasive, but the sensitivity and anatomical spatial localization are weak. "Intracranial cortical electrodes" are electrodes placed on the surface of the brain under the skull and are often used in the cerebral cortex of patients with epilepsy; The "Utah electrode array" inserts electrodes deep into the brain, which is mainly used for language and motor damage, but the disadvantage is that patients need to train in the hospital for a long time and cannot return to their families in a short time.
Compared with the main solutions on the market, Zhao Guoguang said that the wireless minimally invasive implanted brain-computer interface neo used by the current team not only meets the technical sensitivity in implantation, but also does not cause damage to brain tissue, and can also be placed for a long time, and the amplitude, bandwidth and frequency of the collected signals can meet the current clinical needs.
On the operating table, the doctor only needs to perform minimally invasive surgery such as "inserting electrodes in the skull", and the basic equipment for the human brain to "talk" with the computer can be completed.
Hong Bo made a vivid analogy: if the brain is compared to a boiled egg, after peeling off the shell, there is a white protective film, which is equivalent to the dura mater of the brain, which can protect the brain environment from external interference and cells from damage. The electrodes are placed on the dura mater and the 329 parts are placed in a titanium shell the size of a coin. Two coin-sized brain-computer interfaces were implanted into the skulls of high paraplegic patients to collect nerve signals in sensorimotor brain regions and decode hand grasping actions.
The semi-invasive solution is placed outside the brain hole, and there is no damage to brain cells, and there is no risk of infection, immune rejection, etc. Hong Bo introduced that in comparison, the fully invasive brain-computer interface used by Musk's team needs to be connected to the data plug for disinfection operation every time it is used after it is connected to the cerebral cortex. In order to avoid the risk of infection, such clinical trials currently require patients to be permanently placed in the hospital** and observed.
Technically speaking, different paths can achieve the goal of brain-computer interface, but the application scenarios and advantages and disadvantages are different, and there is no high or low. Hong Bo said.
The picture shows the wireless minimally invasive implanted brain-computer interface neo system and its in vivo (synthetic**) from Tsinghua University School of Medicine).
A 14-year-old paralyzed person who has achieved self-drinking water.
We are not challenging ordinary diseases, but some diseases for which humanity currently has no solution. Zhao Guoguang said that in order to install brain-computer interfaces on people, the difficulty lies in being able to collect signals, and to let the signals "decode" language, movement, and consciousness. "It's the challenge of impossible," he said. ”
To some extent, Lao Yang, a 54-year-old quadriplegic patient, was the first person to "successfully eat crabs".
For 14 years, Lao Yang was paralyzed by a car accident that caused him to lose his motor ability and his hands were completely paralyzed.
The experts evaluated Lao Yang's ** and diagnosis, and after seeking the consent of the family and Lao Yang, a new technology of "brain-computer dialogue" was launched. With the support of new technology, Yang hopes to regain the ability of his right hand and complete actions such as drinking water, eating, and even writing. Zhao Guoguang said that the strong desire of patients to restore health supports the best training of patients and also promotes the clinical trials of the medical team.
A pneumatic glove was put on Lao Yang's hand, and it was learned from the electrodes in the sensorimotor area on the right side of the brain that Lao Yang wanted to move his right hand. After the computer "read" Lao Yang's thoughts, the decoding was completed, and the instructions were conveyed to the pneumatic gloves, assisting Lao Yang to bend the fingers of his right hand in coordination and grab the mineral water bottle. The decoding algorithm uses explainable machine learning techniques and is completed by Hongbo's team.
In this "silent" brain-computer dialogue, Lao Yang's skull is embedded with an internal machine, and the electrodes are covered on the epidural. The external computer supplies power to the internal computer through the scalp, and receives the nerve signals in the brain, transmits them to the computer or mobile phone, and realizes brain-computer interface communication with the help of decoding algorithms.
In practice, Hong Bo and Zhao Guoguang's team first used functional magnetic resonance imaging technology to complete the localization of the motor sensory brain area, accurately capture the signal of the brain activation area when the right hand wants to exercise, and then accurately design the contact point of the electrode implantation according to the captured position. Under normal circumstances, the "headquarters" of the human brain can directly mobilize the "companies" of the body, but for patients with spinal cord injury, "the road in the middle is blocked, and the 'headquarters' shouts the slogan, and we must use technology to open the blocked part and connect the signal".
Zhao Guoguang explained that from animal experiments to clinical practice, it is necessary to ensure that the system can collect signals, and the signals are "beautiful, sensitive, and interference-free", so as to be able to efficiently receive and convey the instructions of the human brain.
According to Hong Bo, in order to ensure the privacy of the "brain-computer dialogue", the team has set up an authentication chip in the power management, which must be paired with the in vitro machine in vivo in order to start the signal acquisition system in the human body and protect the privacy and security of patients. The skull-implanted machine does not require a battery, and the patient can use it for life, and can be discharged home after 10 days of surgery.
In this "brain-computer conversation", the computer can do instant sensing. Hong Bo explained that after testing, it takes 250 milliseconds or less, and the computer will quickly "read" the patient's thoughts and determine whether to grasp, hold or release to achieve accurate interpretation. When "talking" to a computer, the human brain does not need to rely on powerful thoughts or repetitive thoughts to convey information.
Nowadays, drinking orange juice and tea independently is already a very easy thing for Lao Yang. For 14 years, Hong said, patients were unable to drink and eat on their own, "which is a qualitative change for him."
After 3 months of home brain-computer interface** training, Lao Yang can drive pneumatic gloves through EEG activity, and the grasp and decoding accuracy is more than 90%.
Hong Bo led the team to carry out animal experiments for 3 years. After installing the motor and the internal machine on the pig's body, after more than 1,000 days of testing, it was verified that the instrument would not cause damage to the nerve tissue below the pig's meninges, and it could also stably collect the nerve signals transmitted in the pig's brain. It wasn't until the clinical trial of the wireless minimally invasive brain-computer interface was filed with the Shanghai Municipal Medical Products Administration and passed the ethics review at Xuanwu Hospital in May 2023 that they began small-scale clinical trials on humans.
In the Clinical Translational Research Center of Brain-like Intelligence of the China International Institute of Neuroscience in Xuanwu Hospital, an evaluation area, a daily training area, and a brain-computer interface training area for patients with spinal cord injury have been set up. Wang Changming, associate professor of Xuanwu Hospital, said that when patients complete the assessment, they should receive full-module training in the research center, and even after returning to their families, the medical team will follow up regularly to further promote patients.
On December 19, 2023, the second patient with spinal cord injury has been successfully implanted under the operation of Professor Jia Wang's team at Beijing Tiantan Hospital, and the signal reception is normal. The 36-year-old patient with a spinal spine injury can use his "mind" to drive the movement of the computer's cursor in the "brain-computer dialogue", realize the action of the red ball hitting the blue ball on the screen, and perform human and computer "telepathy".
To complete such a technological breakthrough, it cannot be done in 10 years. Hong Bo mentioned that this technology is not in a hurry, and it is not in a hurry. "Because it's not a game product, it's not an information product, it's an implanted medical device, and patient safety comes first. He said.
The picture shows students from Yanshan University demonstrating the "brain-computer fusion intelligent auxiliary manipulator system" to grab drinking water bottles in the BCI brain-controlled robot competition area. (*From China News Service).
Turn to the first page of the brain-computer interface.
In 2005, Ray Kurzweil wrote in the book "The Singularity is Approaching"** that with the geometric acceleration of nanotechnology and biotechnology, human intelligence will be greatly improved in the next 20 years, and the future of mankind will be fundamentally reshaped. This brain-bending genius proposed the concept of the "singularity", arguing that future technological changes will tear apart the structure of human history and overcome the limits of biological evolution.
Bringing humanity to digital immortality is a bold and crazy dream, and the technological exploration has not stopped.
In 2020, Zhejiang University cooperated with the Department of Neurosurgery of the Second Affiliated Hospital of Zhejiang University School of Medicine to complete the first clinical study of implantable brain-computer interface in China. The patient uses the signals of the motor cortex of the brain to accurately control the movement of the external robotic arm and the manipulator in three-dimensional space, and realize actions such as shaking hands, holding drinks, and playing mahjong.
In 2023, compared with invasive and non-invasive technical solutions, the team from Nankai University will take the lead in realizing an interventional brain-computer interface brain-controlled robotic arm in the monkey brain, providing a new direction for the diagnosis and treatment of stroke, ALS, depression and other diseases in the future.
In August 2023, the Ministry of Industry and Information Technology and other four departments issued the "Implementation Plan for the New Industry Standardization Pilot Project (2023-2035)", which mentioned that it is necessary to carry out research on the roadmap for the standardization of brain-computer interfaces. Accelerate the development of basic common standards such as brain-computer interface terminology and reference architecture. Carry out research on input and output interface standards such as brain information reading and writing, data format, transmission, storage, representation and preprocessing standards, and brain information encoding and decoding algorithm standards. Carry out pre-research on manufacturing, medical health, education, entertainment and other industry applications and safety ethics standards.
The era of brain-computer interfaces is coming.
Incredible goals will give scientists a never-ending motivation. Hong Bo believes that there is still a lot of work to be done to understand the working mechanism of the human brain and realize the high-bandwidth dialogue between the human brain and the machine brain.
The high throughput and heat generation of brain-computer interfaces are a major technical hurdle to overcome. Hong Bo explained that at present, our minimally invasive brain-computer interface can only achieve simple hand movements. However, in order to obtain more information about advanced cognitive activities in the future, the number of channels will inevitably increase, so overcoming the heat problem and dealing with the balance between safety and stability is a challenge for engineers.
Lao Yang's right hand can hold a water bottle" brought Zhao Guoguang a new thinking that if you "decode" the movement of Lao Yang's right hand in Chinese, it can be interpreted as "grasping", "holding", "holding", "pinching", "holding", etc., while decoding in English can only be interpreted as "hold". He hopes that in future explorations, new technologies can more accurately adapt to the Chinese context and identify and output instructions in patients' brains more quickly.
The Research Report on the Development and Application of Brain-Computer Connectivity (2023) recently released by the China Academy of Information and Communications Technology and the Brain-Computer Interface Industry Alliance pointed out that the current main application direction of brain-computer connectivity is in the medical field, and this technology can bring new solutions for the diagnosis and treatment of neurological diseases such as epilepsy, Parkinson's, depression, ADHD, paraplegia, and stroke.
In the future, in order to break through the limits of human diagnosis and treatment of some diseases, brain-computer interfaces will also face challenges such as large-scale clinical trials.
In the next step, we hope to help patients use brain signals to direct the switch on and off of smart devices at home, such as mobile phones, wheelchairs, electric curtains and other equipment, so as to provide more possibilities for the connection between people and things. Hong Bo said.
Before the Spring Festival in the Year of the Dragon, Hong Bo helped the second patient to read the book software in the tablet. He has an expectation: he hopes to help patients realize their desire to flip through e-books after the Spring Festival.
The phased breakthrough of brain-computer interface is not an end, but a new beginning. Hong Bo said. (End) (Original title: The era of brain-computer interface is coming).
Author: Yang Jie, Yin Xining.
*: China Youth Daily.