In the hospital, the mention of surgery always causes panic among patients and their families. This is no wonder, because traditional surgical operations involving knife and scissors inevitably involve bleeding. In order to ensure the smooth progress of the operation, nurses always prepare a lot of hemostatic instruments, absorbent cotton, gauze and other things, which adds to the tense atmosphere in the operating room.

Nowadays, laser scalpels have been used in many surgical operations, which has changed people’s belief that bleeding is necessary during surgery.

The so-called laser knife is a new type of medical instrument that uses laser beams to perform operations such as excision, coagulation, hemostasis, and vaporization of human tissues. It radiates a laser beam with a wavelength that is easily absorbed by human tissue through a laser. During the absorption process by human tissue, it converts light energy into heat energy to destroy diseased tissue and achieve the purpose of treatment.

Each part of the human body absorbs laser light to different degrees, and lasers of different wavelengths and powers have different effects on certain parts of the human body. Therefore, using lasers with different oscillation frequencies to obtain lasers with different wavelengths and making various laser knives can selectively have different effects on human tissues and achieve different treatment purposes. Currently, the following types of laser scalpels are commonly used:

Carbon dioxide laser scalpel This laser can radiate a laser beam with a wavelength of 10.6 microns. Laser light of this wavelength is almost entirely absorbed by water in human tissue. After the laser is absorbed by the surface of the tissue, the light energy is quickly converted into heat energy, causing the water in the surface tissue to boil and evaporate. Along with the wisps of white smoke, the diseased tissue is dehydrated, vaporized, and solidified. Therefore, there will be no bleeding when using this laser knife to remove diseased tissue. Carbon dioxide laser radiation penetrates the tissue only 0.5 to 1 mm deep, forming a narrow thermal burn zone on the side of the incision. Therefore, as a "light knife", it can be used in many aspects of surgery.

The radiation wavelength of this laser is 1.064 microns. Water in human tissue has a relatively weak ability to absorb this wavelength. Using it as a scalpel to remove tissue is slightly less effective than a carbon dioxide laser. However, the laser beam of this wavelength has strong penetrating ability and can penetrate deeply into the tissue to coagulate the proteins in it to achieve the purpose of treating diseases. Another aspect that is different from the carbon dioxide laser beam is that it can be transmitted smoothly through optical fibers, using endoscopic technology to heat and stop bleeding in hard-to-reach parts of the human body (such as the chest cavity, abdominal cavity, etc.).

The radiation wavelength of the argon ion laser scalpel is 0.488 to 0.515 microns. It can hardly be absorbed by the water in human tissue, but it can be absorbed by the hemoglobin in the blood, causing the The blood is thus coagulated and therefore has a good hemostatic effect.

Combined laser scalpels In recent years, some "combined laser scalpels" have appeared. For example, the so-called "combined laser surgical device" synthesized from a neodymium-doped yttrium aluminum garnet laser and a carbon dioxide laser, is that the two lasers work coaxially and act on human tissues through reflectors and focusing. This method can be used for blood-rich organs (such as liver and spleen). Its characteristic is that it stops bleeding and coagulates while cutting at the same time, so there is very little bleeding and the time is quick.

The infrared laser radiated by carbon dioxide lasers and yttrium aluminum garnet lasers is often invisible, which makes operations that require high precision such as removal of internal organs difficult. In order to solve this problem, in the early domestic laser surgical instruments, a helium-neon laser that emits a bright red visible light laser beam was installed side by side with the carbon dioxide laser. The two lasers work synchronously, and the optical system guides the two laser beams on the coaxial optical path, so that the surgery can be performed according to the instructions of a bright red beam. In order to reduce costs, reduce volume, and save energy, laser diodes are commonly used as guide beams in recently imported carbon dioxide laser surgical instruments. The effect is similar to that of helium-neon lasers, which is worthy of reference for Chinese technicians.

At present, there are several joints equipped with optical reflectors in the optical path of the carbon dioxide laser scalpel, so as to have a greater degree of freedom. However, if there are too many such joints, it will cause operational difficulties. inconvenient. Therefore, special optical fiber materials have been developed in order to introduce flexible optical fibers into carbon dioxide laser blades to replace bulky optical connectors. Such as KRS-5, TIBr and other crystal fibers, etc. In the yttrium aluminum garnet laser knife, quartz optical fiber can be used as a flexible light guide path to guide the laser into the body in conjunction with the endoscope.

Diode laser scalpel As we all know, lasers using semiconductor diodes generally have relatively low power and can only be used in communications, audio, monitoring and other fields. Products directly used for cutting are extremely rare. However, the Diomed diode surgical system launched in the UK breaks this traditional concept. It is said to be the world's first such laser used in surgery. It has a wavelength of 805 nanometers, can use single-mode optical fiber, and outputs a power of 30 to 35 watts. It can be used in any contact or non-contact surgical procedure. There are three reasons for its strong market competitiveness. First, it uses diode lasers, which reduces investment costs; second, compared with other lasers, diode laser systems have a long life and are maintenance-free. Third, the entire system is compact in structure, small in size, easy to carry, and can be moved at will in clinical applications.