Basic information
Femtosecond laser
Femtosecond laser surgery
Essence: The laser runs in pulse form.
Purpose: High-density information storage and recording.
Features: Very high precision.
brief Introduction of the content
Femtosecond laser essence
Femtosecond laser is a kind of laser that runs in pulse form, and its duration is very short, only a few femtoseconds. One femtosecond is 10 to the fifth power of10, which is11000 trillion seconds, which is several thousand times shorter than the shortest pulse obtained by electronic method. This is the first characteristic of femtosecond laser. The second characteristic of femtosecond laser is that the instantaneous power is very high, reaching tens of billions of watts, which is 100 times more than the total power generated in the world at present. The third feature of femtosecond laser is that it can focus in a space smaller than the diameter of a hair, so the intensity of electromagnetic field is several times higher than the force of nucleus on surrounding electrons.
Femtosecond laser application
What is the use of femtosecond laser? As we all know, matter is composed of molecules and atoms, but they are not static, they are all moving rapidly, which is a very important basic attribute of microscopic matter. With the appearance of femtosecond laser, it is the first time for human beings to observe this ultrafast motion process at the level of atoms and electrons. Based on these scientific discoveries, femtosecond laser has been widely used in physics, biology, chemical control reaction, optical communication and other fields. It is particularly worth mentioning that femtosecond laser has its unique advantages and irreplaceable role in early diagnosis of lesions, medical imaging and biological detection, surgical treatment and ultra-small satellite manufacturing.
Under the action of high-intensity femtosecond laser, there will be a very strange phenomenon in matter: gaseous, liquid and solid matter will become plasma in an instant. This plasma can radiate lasers with various wavelengths. The collision of high-power femtosecond laser with electron beam can produce hard X-ray femtosecond laser, β-ray laser and electron-positron pair.
High-power femtosecond laser has a good development prospect in the fields of medicine, micro-machining, high-density information storage and recording. High-power femtosecond laser can also penetrate the atmosphere, thus creating discharge channels, realizing artificial lightning and avoiding catastrophic damage caused by natural lightning strikes such as airplanes, rockets and power plants. Femtosecond laser can accelerate electrons very effectively, and the scale of the accelerator can be compressed by thousands of times. The interaction between high-power femtosecond laser and matter can generate enough neutrons to realize the rapid ignition of laser-controlled nuclear fusion. Thus opening up a brand-new road for mankind to realize a new generation of energy.
Characteristics of femtosecond laser
1, femtosecond laser is the shortest pulse we can get under experimental conditions at present, with an accuracy of 5 microns;
2. Femtosecond laser has very high instantaneous power, which can reach tens of billions of watts, hundreds of times more than the total power generated in the world at present;
3. Matter will produce very strange phenomena under the action of femtosecond laser. Gaseous substances, liquid substances and solid substances will instantly become plasma;
4. Femtosecond laser has the characteristics of accurate targeted focusing and positioning, which can focus on the ultra-fine space area much smaller than the diameter of hair;
5. Femtosecond laser surgery has no thermal effect and shock wave, and there will be no tissue damage in the whole optical path.
Advantages of treating myopia
1, greatly reducing the risk of surgery.
Greatly reduce the risk of surgery. In the traditional lamellar knife surgery, if the negative pressure ring is loosened during the rotation of the blade, the corneal flap will be completely failed, and the operation will not be performed until three months later, which will bring great psychological pressure to both patients and doctors. However, if a similar accident occurs in femtosecond laser surgery, the doctor only needs to put on the negative pressure ring again and replenish the laser immediately without interrupting the operation. Because femtosecond laser only produces some water and bubbles to push away corneal tissue when making corneal flap, there is no damage to the tissue, and multiple operations can be performed in the same affected area, and the safety is greatly improved. At the same time, it is worth noting that excessive negative pressure is harmful to the fundus, and the negative pressure of the lamellar knife is low, while the lowest negative pressure among femtosecond lasers is the Ziemer LDV femtosecond laser.
2, embedded corneal flap, more accurate reset.
Embedded corneal flap, more accurate reduction. The lamellar knife is cut horizontally, and the eyeball surface is a sphere, so the corneal flap section is a "cup cover", which is not well fixed with the eyeball matrix. The corneal flap made by femtosecond laser is embedded with the eyeball matrix in the form of "underground manhole cover", which is easy to reset and tightly bite, and will not be dislocated, and there will be no complications such as broken flap and button flap. At the same time, its laser light source also avoids the residual metal fragments that may be caused by the use of laminating knives.
3. Avoid iatrogenic infection
Avoiding iatrogenic infection In order to reduce the cost of LASIK surgery, many small laser ophthalmology institutions do not strictly implement the principle of "one person, one tablet" and reuse disposable surgical blades, which greatly increases the medical risks such as cross-infection. "Femtosecond laser" made human beings get rid of the lamellar knife for the first time in corneal surgery, and the situation of cross-infection in surgery became history.
4. The postoperative visual quality is more perfect.
Better visual quality after surgery "Femtosecond laser" can accurately open the molecular chain of eye tissue, make a more uniform and perfect corneal flap, effectively avoid the iatrogenic aberration that may be caused by the manufacture of lamellar knife flap, avoid glare and blur in foggy days, rainy days, driving at night and other visual conditions, so that myopia can obtain perfect visual quality.
5, the accuracy is improved by a hundredfold.
The accuracy of "all-laser" surgery is improved 100 times. The accuracy of "femtosecond laser" is more than 100 times of that of lamellar knife, which is beyond the reach of lamellar knife and is safer for any patient.
6, the scope of correction is wider.
It is not affected by corneal curvature and has a wider correction range. Previously affected by corneal thickness. Nearly 10% of patients can't receive traditional laser surgery such as LASIK because of their deep myopia and thin cornea. Femtosecond laser surgery is not affected by corneal curvature, which is a great blessing for myopia patients with thin cornea and large variation of corneal curvature. With the strength of the hospital, there is no problem in doing this operation.