**: People's **Overseas Edition.
Professor Zhao Guoguang's team performed the first wireless minimally invasive brain-computer interface implantation surgery. The pictures in this article are provided by Xuanwu Hospital of Capital Medical University.
Wireless minimally invasive implantation of the brain-computer interface neo system and its in vivo machine.
Lao Yang successfully achieved brain control and grasping through wireless minimally invasive brain-computer interface.
Lao Yang held the water cup firmly with his right hand wearing pneumatic gloves, picked it up, drank the water, and then put the water cup down. This action that ordinary people are accustomed to is a "miracle" in Lao Yang - Lao Yang was quadriplegic due to a car accident and has been bedridden for 14 years!
What made Lao Yang go from paralysis to "drinking water with his mind" was brain-computer connection.
On January 29, the team of Professor Zhao Guoguang of Xuanwu Hospital of Capital Medical University and the team of Professor Hong Bo of Tsinghua University School of Medicine announced that the world's first implantable epidural electrode brain-computer interface assisted ** quadriplegic patients with cervical spinal cord injury have made a breakthrough in their behavioral ability. The patient in this case is none other than Lao Yang, who underwent brain-computer interface surgery in October last year.
Almost at the same time, the American company Neuralink carried out the first human transplant of a brain-computer interface device. On February 20, local time, the company's founder Elon Musk announced the latest breakthrough: the first patient implanted with the company's brain-computer interface device has been able to directly control the computer mouse through the brain.
Far across the ocean, scientists in China and the United States have achieved this seemingly sci-fi technological breakthrough almost simultaneously. In addition to Musk's brain-computer technology news swiping, what are the characteristics of the Chinese version of brain-computer connection? How does it work? With these questions, our reporter interviewed Professor Zhao Guoguang's team in Xuanwu Hospital.
How did Lao Yang's right hand move.
The so-called brain-computer interface is usually to capture the electrical activity inside the brain through the device, and then create a direct communication path, so that the signal connects the brain with the computer, and realizes the "mind control computer".
It does sound sci-fi, and we slowly disassemble it. Technically, to get the right hand of Lao Yang, a quadriplegic patient, to move, it takes three steps.
The first step, where is the processor placed to capture the EEG signals? This is to find a foothold for the brain-computer interface processor.
On October 24, 2023, Professor Zhao Guoguang's team and Professor Hong Bo's team from Tsinghua University School of Medicine jointly completed the first clinical implantation trial of wireless minimally invasive implantable brain-computer interface neo (neuralelectronicopportunity).
Specifically, a brain-computer interface processor the size of two coins was implanted into Lao Yang's skull through the operation of a neurosurgeon to successfully collect intracranial nerve signals in the sensorimotor brain region.
The two processors each have 4 contact points, for a total of 8 contact points, which are placed on the brain motor area that governs Lao Yang's right hand. Zhao Guoguang, president of Xuanwu Hospital, explained, "How to find this area? Before the surgery, we used an MRI of brain function – whether it was when Yang's right hand was moving passively or when he wanted to move, the MRI would show the activation area of the brain, which allowed us to find it. ”
It's not easy. "We don't open the dura mater that wraps around the brain, but we have to precisely place each point of contact in the sensory and motor areas, which requires extremely precise navigation. Because you can't see the ** of the brain, even if you see the sulcus of the brain, it is difficult to identify. Zhao Guoguang said.
He made an analogy: "It's like when we walk into a football stadium and there are 30,000 or 40,000 spectators shouting cheers at the same time, and we have to detect what two people in row 80 of the South Stand are saying." Moreover, there are thousands of brain cells, and the difficulty can be imagined. ”
In the second step, the area is determined, how to bury the device in the brain? This is where the right technology is chosen.
It's not enough to find the activation area, how to implant a brain-computer interface processor? Different from Neuralink's "telepathy" technology, the Chinese team has achieved two major breakthroughs in wireless minimally invasive technology
On the one hand, by implanting the brain-computer interface NEO, the internal machine is buried in the skull, and the electrodes are covered on the epidural to ensure the quality of intracranial signals without damaging the nerve tissue. On the other hand, it uses near-field wireless power and signal transmission, and the internal machine implanted in the skull does not require batteries.
We design to avoid complications. If the cerebral effusion leaks, the device will be soaked for a long time, and the chance of infection is very high, so we did not break through the dura, but 'worked' on the epidural. In other words, under the device is a water bladder that encloses important brain tissue, and instead of piercing the water bladder, we collect brain signals on the surface of the meninges, so that the brain tissue is not damaged. Zhao Guoguang said.
In our system, charging the 'brain computer' and signal acquisition are wireless, the so-called 'inside should be outside'. This allows the patient to adapt to the device more quickly, satisfying the recorded sampling rate and ensuring a long-term energy supply. Zhao Guoguang said.
The third step is to bury the processor and capture the signal, and the next problem is how to "decode" the brain signal into computer language.
Ten days after the successful operation, Lao Yang was discharged from the hospital and went home. When used at home, the external computer needs to supply power to the internal machine through the scalp, receive nerve signals in the brain, and then transmit it to the computer or mobile phone, and finally realize brain-computer interface communication.
We have encountered countless millisecond-level electrical signals, just like the book of heaven, and we don't know what it represents without analyzing it. So, decoding is very important. Zhao Guoguang said, "What code is it solved?" The code that the computer can understand is 0 and 1. After decoding, it can be converted into various life scenarios, such as pneumatic gloves that control grasping objects, control electric wheelchairs, and turn on and off televisions, all of which can be controlled by mind. ”
After 3 months of home** training, Lao Yang has been able to drive pneumatic gloves through brain electrical activity, realize brain control functions such as drinking water independently, and the grasping accuracy rate is more than 90% - this is the scene at the beginning of this article. The patient's functional score for spinal cord injury (ASIA) and sensory evoked potential measurement also improved.
Brain-computer interfaces will benefit more patients.
We are especially grateful to Lao Yang, who was the first to eat crabs, reflecting the exuberant vitality and strong desire to restore health. Zhao Guoguang said, "Through brain-computer connection, Lao Yang can make significant improvements within 3 months, which is exciting for patients, patients' families, medical staff, engineering and technical personnel and equipment manufacturers, and inspires us to explore more unknown areas more actively." ”
In the future, the application scenarios of brain-computer interface are very wide. By recording and interpreting brain signals, the direct communication between the brain and the computer can not only help patients with ALS, spinal cord injury, epilepsy and other brain diseases, but also is expected to realize brain-computer fusion intelligence and expand the ability of human brain information processing, which has a wide range of application prospects.
Taking epilepsy** as an example, Zhao Guoguang's team received a 15-year-old girl. She suffered from epilepsy for 12 years, with violent convulsions in her right hand and spasms throughout her legs, more than 700 seizures a month. According to Zhao Guoguang, by putting the corresponding device and electrodes into the patient's brain, the number of seizures was reduced to 480 in the first month after surgery, 57 in the second month, and the seizures stopped in the fifth month.
When the girl came for a follow-up, the condition of the whole person had improved due to the elimination of the disease, and the medical staff almost did not recognize her. "Being able to help patients relieve their pain and return to normal life is our greatest happiness as doctors. Zhao Guoguang said.
In fact, it has been 50 years since the concept of brain-computer interface was proposed. In recent years, related research has become a popular track for R&D in various countries. Zhao Guoguang said that on this track, China is currently in the first group, and the development is very fast, "We are looking forward to the originality from 0 to 1, and we also need a leap from 1 to 100; Through the analysis of data from 1 to 1000, it can promote the development of original technology. Every track, every stage, we must continue to exert force. ”
In Zhao Guoguang's view, the activity of a normal person is like a brain functional area singing solo, and after the function is impaired, the voice of the solo singer disappears. "The emergence of brain-computer interfaces is to hope that the people around them will sing in chorus, instead of soloists, and continue to play the music. ”
In order to complete this healthy chorus, the Chinese technical team will continue to explore. (Xiong Jian, Zhao Jingfan).
People** Overseas Edition (2024-02-23 Edition 09).