Jens, who has been blind for decades, has seen the light again. Recently, he had an operation, and the cost was as high as 165438+5000 dollars (about 980,000 yuan). The surgeon drilled a hole in his skull and placed a series of electrodes on the surface of his brain. These electrodes are connected with a miniature TV camera and a computer, which gives Jens some preliminary visual functions.
After the operation, Jens showed his restored vision in new york, although it was only partial, including crossing the room without any auxiliary equipment, finding the door and driving around the parking lot for a while, avoiding the garbage bin and all kinds of obstacles he encountered.
Scientists struggled for 20 years, created an artificial vision for the blind, and finally found the north at the beginning of 2 1 century. Jens is one of the few people in the world who accept the newly developed treatment to restore the visual function of the blind. Scientists say that the number of blind people receiving this kind of treatment will not increase rapidly. However, the success of Jensen's operation means a major breakthrough in medicine and science, which brings hope to other blind people in the world.
This new breakthrough in the field of science and technology has brought impetus for further research to various research institutions around the world. They are scrambling to invest manpower and material resources for the same goal, that is, to bypass the damaged components of the visual system and restore their vision. Some research institutions are developing artificial retinas, some are using electrodes to stimulate the nervous system of the eyes, and some are still trying to directly stimulate the brain. However, research belongs to research, and these ideas are rarely verified in humans.
"We are still in a very early stage, and we still have a lot of work to do ... such as making artificial vision develop to make it easy to see moving objects," said Dr. William Hitders of the National Institutes of Health. ""technical problems cannot be underestimated. "Although the equipment used by Jens is being introduced to other users, experts predict that it will take at least ten years for this equipment to be widely used.
According to a recent report, more than/kloc-0 million Americans over 40 years old are blind, and another 2.4 million Americans are seriously damaged by retinopathy caused by diabetes, common senile retinopathy, cataract or glaucoma.
It is predicted that this number will double in the United States in the next 30 years due to the aging population. According to the data of China Population Information Center, at present, the elderly population in China has reached 1.36 billion, accounting for about 10% of the total population. It is estimated that by 2050, the elderly population in China will reach 438 million. New drugs and other treatments can help these patients delay blindness, but once patients become blind, doctors are traditionally hopeless.
These three laboratories are pioneers in the academic field in the research of helping the blind to see again.
Microelectrode group
One of them is the Doheny Retinal Research Institute of the University of California, which has developed a microelectrode device that can be implanted in the eye to replace the damaged retina. This array is connected by ultra-fine wires buried under the skin and a radio receiver implanted behind the ear.
The visual signal from the camera is processed by a microcomputer connected to the belt and then transmitted to the receiver. This retinal array stimulates the optic nerve and then sends information to the brain. This signal is a recognized optical illusion and bright spot in the medical field. If the stimulus is appropriate, the bright spot can draw a picture in the brain. In the brain, it is similar to seeing the electronic scoreboard of the stadium in sports competitions. The recorded score consists of a series of light bulbs.
The Doheny Institute of Retinology found that the preliminary results were satisfactory. Scientists have found that the brain can identify many bright spots. Doheny Lab then used this instrument on 17 blind people. When they only use four electrodes, patients can tell whether an object is in front of them, moving from left to right or vice versa. When they use the 4*4*** 16 electrode group, patients can see the shape of the object and describe the flowing liquid, and they can also pour one cup into another. If blind people want to read, scientists estimate that they need 1 000 electrodes.
In February this year, scientists implanted a set of 4 * 4 * * 16 electrodes into a patient's head permanently, which was much better than short-term implantation. The brain often actively learns how to interpret visual signals. They plan to do two more cases this year. The equipment is produced by Second Vision Company in Valencia, and the second generation version of the equipment is developed by San Diego National Laboratory.
If these three operations are successful, the Food and Drug Administration has approved the Doheny Retinal Research Institute to perform another seven operations. But it takes a long time to complete this test. The equipment mentioned above is listed as a three-pole equipment by the US Food and Drug Administration, that is, high-risk equipment, because this equipment will accompany the patient for life. Finally, Dr. Huang from the Doheny Retinal Research Institute said that they wanted to minimize the equipment and finally make it suitable for implantation in the eyeball. The Massachusetts Eye and Ear Clinic in Boston and the Catholic University in Lowyn, Belgium are developing similar technologies.
Miniature artificial retina
Dr Zhou Allen of the University of Illinois Chicago Medical Center has developed an artificial retina that can be completely implanted in human body, but how this device works is still controversial. Dr. Zhou developed a chip with a diameter of two microns, which is smaller than a needle. In other words, the diameter of this chip is only half the thickness of a piece of paper.
This chip contains about 5000 small solar cells, and each small solar cell is attached to the microelectrode behind the chip. The idea is that light shining on the chip will activate the electrodes and stimulate the optic nerve behind the retina. Many critics, such as scientist Hitdex, think that solar cells can't generate enough current to activate nerves. Anyway, Dr. Zhou has implanted this device in six patients. "All patients' visual function has improved, sometimes by a large margin," said Dr. Zhou. For example, a patient has never seen light before, but now she can see the person standing in front of her.
Dr. Zhou also admitted that the implanted artificial retina may not achieve the function designed by the designer. Retinal cells are completely separated from the implanted artificial retina, which means that surgery may trigger the growth of some substances or the action of a chemical substance in the eye, which will lead to the regeneration of retinal cells. Some blind patients have seriously damaged the visual nerve. For them, simple artificial retina implantation will not play much role. For them, more active and aggressive treatment methods must be adopted.
Skull implantation
William D'Aubert, an electrical engineer at D'Aubert College in new york, USA, has been developing such a device for thirty years. He developed a miniature device, including 64 electrodes, implanted on the surface of the pituitary gland in the occipital lobe of the skull. This device is directly connected to an electronic socket through the skull and skin. Outside the skull, the device is similar to retinal stimulation device, which uses TV camera and microcomputer to process visual signals.
D'Aubert's team has implanted the device into the skulls of eight patients from six countries. A patient was blind in one eye from birth and the other eye at the age of 45. Another 77-year-old patient who underwent surgery lost his eyes in World War II. Insurance companies help some patients pay all or part of the operation expenses, but most people have to pay 1 15000 dollars for the operation expenses. Due to the strict restrictions on brain implantation of medical devices in the United States, all operations were performed in Lisbon Medical College, Portugal. Electrodes are implanted on both sides of the brain.
Successful surgical results show that some patients can not only see objects, but also see colors. Initially, the device was designed to observe moving objects, not to help blind people read, but Dr. D'Aubert said that further research and experiments will enable patients to watch TV and read words on computer screens. However, the disadvantage of this device is that the electrodes implanted in the brain need high voltage to stimulate some parts of the brain, which may cause seizures in some cases.
"The devices we need to develop are very small, and the brain is required to have no obvious rejection of these devices," said Dr. Norman of the National Institutes of Health. "This is a challenging problem, but if the research is successful, then this technology can not only help the blind, but also help patients with deafness or spinal cord injury." He said.
It will take some time for the further progress of this research, but every step will be the representative of the gospel of patients with physical disabilities in the world.
There is still some way to go in all these areas, but the progress is encouraging. In the long run, many researchers believe that implanting electrodes deep in the brain will provide the best results, but other options may provide benefits for blind people who can't wait there for a long time.
"I believe that the literacy system for the blind, the crutches for finding the way and the dogs that can lead the way will become antiques one day," D'Aubert said. "At the end of this century, they will be replaced by new technologies, just as airplanes replace steamboats."