The first laser (LASER is Englishstimulated radiation for optical amplification: the use of induced (stimulated) radiation for optical amplification) abbreviationis the most recent design andThe test (ruby) was 55 years ago, in 1960. Since then, laser cosmetology has been one of the most needed fields in aesthetic medicine.
Laser equipment is very successfully used for hair removal, skin rejuvenation, lifting, removal of blood vessels, age spots, scars, stretch marks, post-acne, vegetation, tattoos, for the treatment of vitiligo, psoriasis, acne (acne), nail growthBig.
Today’s review of laser equipment is very professional: we will familiarize readers with the detailed information of skin rejuvenation equipment.
The laser is composed of three main elements:
- Energy (or "pump" mechanism);
- Work organization (activity environment);
- Mirror system (optical resonator).
EnergyIt can be electric discharge, flash lamp, arc lamp, other laser, chemical reaction, etc. They use energy to activate the working medium.
working fluidis the main determinant of the generation wavelength and other laser characteristics (monochromatic, coherent, narrow focus). There are hundreds of different working bodies, and lasers can be built on this basis. However, the following working media are most commonly used: liquids (consisting of organic solvents with chemical dyes, such as methanol, ethanol or ethylene glycol), gases (gas mixtures, such as carbon dioxide, argon, k gas or helium mixtures)) Neon lasers; these lasers are usually pumped by discharge; solids (such as crystals and glass); solid materials are usually activated by adding small amounts of chromium, neodymium, ium or titanium ions); semiconductors.
Therefore, according to the type of working medium (active medium), the laser is divided into:
- Liquid (on inorganic or organic dyes);
- Metal vapor laser;
- Solid (crystal, glass);
- Semiconductor (or diode).
optical resonatoris two parallel mirrors located around the working body of the laser. The forced radiation of the working medium is reflected between the mirrors and returned to the working medium, thereby accumulating energy. This wave can be reflected many times before it is emitted. In more complex lasers, four or more mirrors are used, which also form optical resonators, but the design is more complicated.
The manufacturing and installation quality of these mirrors is one of the most important conditions for the quality of laser systems.
Also in the laser system, other equipment can be installed to obtain various effects, such as rotating mirrors, modulators, filters and absorbers. Their use allows to change the parameters of laser radiation, such as wavelength, pulse duration, etc.
Technical parameters of laser equipment
Laser energy parameters:
- Power, in watts (W).
- Energy, in Joule (J).
- Energy density (J/cm2).
- Pulse duration, in milliseconds, nanoseconds, and picoseconds.
- Wavelength, in units of micrometers (μm) and nanometers (nm).
The laser radiation acting on the biological body will be reflected, absorbed and scattered. The extent of these processes depends on the condition of the skin: moisture, pigmentation, blood circulation, swelling of the skin and underlying tissues.
Many lasers target specific chromophores, which are biological structures with well-defined absorption spectra. The ability of the chromophore to absorb light of different wavelengths with different intensities is determined by the absorption spectrum. The unit of measure for the ability of a chromophore to absorb laser light is the absorption coefficient.
The absorption spectra of different chromophores are completely different. Therefore, it is important that the wavelength of the laser radiation coincides with the wavelength at the peak of the absorption capacity of the chromophore planned to be exposed.
Therefore, for all indications (appointments), there is no universal wavelength, that is, a laser. Therefore, the laser used for hair removal cannot rejuvenate the skin, and vice versa. Of course, several purposes are often pointed out in the laser manual, but in fact there is only one problem that can effectively solve this equipment.
The penetration depth of laser radiation is inversely proportional to the absorption coefficient and therefore depends on the wavelength. For different chromophores of the skin (water, melanin, hemoglobin, oxygenated hemoglobin), the penetration depth is also different. For example, in the visible light region (0. 38-0. 74 microns or 380-740 nm), the penetration depth is 3-7 mm, and in the infrared region (0. 76-1. 5 microns) -0. 5 to 1The thickness is 5 mm. In the ultraviolet region (0. 3-0. 5 microns), laser radiation is strongly absorbed by the epidermis, so the depth of penetration into the tissue varies from 0. 2 to 0. 4 mm.
Method of producing laser radiation
There arepulsed and continuous lasersthat produce radiation. According to the pumping method, continuous and pulsed laser radiation can be obtained. Pulsed light is generated as a light beam that is interrupted within a certain period of time. Other lasers produce continuous light, and there is a special device that divides the light into short segments. Generally, in addition to physical therapy lasers, lasers that continuously generate radiation also have the characteristics of unwanted heat release at the exposed site, which may cause scar changes and damage to the tissue surrounding the exposed site.
The radiation power of medical (especially cosmetic) lasers varies in a wide range, depending on its application purpose. For lasers with continuous pumping, the power can vary from 0. 01 to 100 W. Pulsed lasers are characterized by pulse power and pulse duration. The power of a pulsed laser is several orders of magnitude higher. Therefore, the pulse energy generated by the neodymium laser is E = 75 J, and the duration is t = 3x10-12 s. Pulse power: P = E / t = 2. 5x1013 W (for comparison: the power of a hydroelectric power station is about 109 W).
In cosmetic practice, including the use of low power (low intensity laser radiation, LLLT) and high power (high intensity laser radiation, LILI) laser radiation during skin rejuvenation surgery.
Low Intensity Laser Radiation (LLLT)
The role of LLLT is to activate cell membrane enzymes and stabilize lipids. It is known that LILI stimulates cell division and development. This effect occurs at the level of subtle atoms and molecules, where energy is absorbed under the influence of a certain frequency of laser radiation (usually in the red and infrared range). This energy absorption leads to a sharp increase in intracellular Ca2+ concentration, that is, the accumulation and release of ATP are activated due to cell proliferation (division), the restoration of cell membranes, the increase in intracellular metabolism and the increase in regeneration processes. The old cells are replaced by new cells in large numbers, and the biological rhythm of this process is restored. This therapy uses a low-intensity laser (intensity of 0. 1-10 W/cm2). The maximum wavelength of the treatment laser is 1300 nm. In particular, diode lasers are used in skin repair procedures:
- emitters with wavelengths of 890 nm and 915 nm (laser revival);
- Low-intensity laser with wavelength from 785 to 890 nm (laser bioregeneration and laser mesoscopic therapy-the active ingredient is delivered to the skin through LLLT)
Due to the low intensity of the treatment laser, it is painless and comfortable for patients. In some cases, you may feel a little warm. However, there is no recovery period, and in order to obtain any noticeable results (improving skin elasticity and firmness, micro-relief, moisturizing and lifting the skin), a series of procedures and support procedures are required.
The basic treatment laser includes a device combined with a control panel (sometimes in the form of a touch screen) and a handheld transmitter. The kit may include multiple transmitters (for example, a larger work surface area for human work and a smaller work area for facial work), as well as accessories for various procedures. The laser treatment instrument is small in size, low in power consumption, and can directly install the working medium in the mobile phone without using light guide tools to transmit radiation.
High intensity laser radiation (wheel)
High-intensity laser radiation (2500 J/cm2) allows a large amount of energy to be concentrated in a small volume, which can lead to local heating, rapid evaporation and hydrodynamic explosion in the biological environment. In terms of beauty, VILI is widely used, one of which is skin rejuvenation.
The use of high-intensity laser radiation to rejuvenate the skin is a modern method that can eliminate, eliminate wrinkle depth and/or reduce wrinkle depth, and improve skin quality. For high-intensity laser rejuvenation, use devices whose radiation is fully absorbed by water (because the moisture in the skin is 77%). The purpose of using this laser is to rapidly increase the temperature in the area where the laser pulse is absorbed as the tissue evaporates instantaneously.
Among various high-intensity laser skin rejuvenation equipment, experts are used to distinguish two main types of equipment: fornon-ablationandablative methods.
Ablation-the evaporation of superficial tissue by laser exposure.
Laser ablation equipmentis very effective in combating age-related skin changes: the degradation of collagen and elastin-the structural protein of the skin, which gives the skin firmness and elasticity. Apply traumatic laser treatment to trigger the renewal process. In addition, it should be noted that the stronger the injury, the stronger the rejuvenation effect, but at the same time the longer the recovery period, the higher the risk of side effects.
This is why the main trend of modern lasers for skin rejuvenation is to seek a compromise, trying to find a way to reduce skin damage, but at the same time it can produce a strong response to the regeneration response.
Modern ablation equipment includes:
- Fractional CO2 laser (carbon dioxide laser);
- Fractional Y YAG laser (solid-state yttrium aluminum garnet crystal laser with ion).
It is necessary to clarify the term "faction" immediately.
Fractional lasers are different from conventional lasers in that the laser beam is forced to split into a group of microbeams ("fractional"). This can be implemented in hardware in several ways:
- With the help of the microlens installed in the handpiece (a large number of beams are irradiated on the skin at the same time);
- In the scanner mode, when a laser beam penetrates the skin sequentially;
- With roller attachment, controlled by laser pulse, can be operated in motion.
This leads to the fact that the laser action on specific areas of the skin becomes incomplete, but regional: not the entire surface of the skin is exposed, but thousands of micro-regions are exposed, withoutThe affected organization remains in it. Local lasers are less traumatic: during tissue processing, they do not cover the entire skin surface, but cover 3% to 70% (depending on the laser settings), while triggering the recovery mechanism of the entire area.
In fact, due to the emergence of fractional lasers, a new era of laser beauty has begun: laser surgery has become less painful and safer ("delicate"), and the recovery time after surgery has been greatly reduced (from two days toA week). At the same time, the clinical effect has not decreased, on the contrary, it has improved.
Modern carbon dioxide lasersoperate according to the principle ofFractional Photopyrolysis, which includes the formation of cylindrical condensation microdomains perpendicular to the skin surface. The term "photopyrolysis" here refers to the destruction of tissue under the influence of temperature, which is caused in the process of transferring laser energy to the tissue (light-light, heat-heating, cracking-destruction). The radiation wavelength of the carbon dioxide laser is 10. 6 microns. When performing a partial rejuvenation procedure, the laser actually removes microscopic areas of the skin over the entire depth of the epidermis (maximum 20 microns), while the thermally damaged area extends into the dermis for 150 microns or more, causing collagen to coagulate. This will produce the desired effect (reduce degeneration of collagen fibers and make the skin smooth).
There are many fractional CO2 devices on the market today, their flux density and pulse duration are adjustable. This allows you to choose the temperature and heating depth of the leather. With the help of new technology, the recovery time after the complete process has been reduced to one week. The company-the distributor of modern carbon dioxide lasers began to promote the procedures carried out with its help to rejuvenate the "weekend", because the "acute" recovery period (severe edema and erythema) during partial laser photothermal decomposition will be two days laterTake a break and go to work on MondayThe
laser has a wavelength of 2. 94 microns, and its absorption coefficient is much higher than that of carbon dioxide lasers. The laser radiation penetrates to a depth of approximately 1 micron, causing rapid vaporization of the thin layer of the epidermis, with little damage to surrounding tissues.
"The rb laser (Er: YAG) is a typical ablation laser. The ablation effect is very obvious, and the upper layer of the epidermis evaporates immediately without any traces. This laser is very suitable for resurfacing, smoothing scars, and removing pigmentComposure. "
Nowadays, when laser is actively used when working in the most sensitive areas (neck and abdominal cavity, paraorbital and periorbital areas). With this laser, each spot can be processed multiple times, and the doctor can control the entire process of "grinding". Plastic surgeons actively use is laser during surgery. Similarly, when the patient is not preparing for a long-term recovery, laser is the first choice.
Non-ablative high-intensity lasersdo not work on the principle of evaporation, but on the principle of heating water and condensing and forming new collagen in the affected area.
In order to implement non-ablation methods, lasers with a large penetration depth into the tissue are usually selected. In this category, for rejuvenation, aneodymium (Nd: YAG) laser(neodymium-doped yttrium aluminum garnet crystal) with a wavelength of 1064 nm is mainly used, which corresponds to the near-infrared spectrum.
The radiation of this laser can penetrate the dermis to a depth of 5 mm. In order to rejuvenate the skin, the laser is usually used in the millisecond and nanosecond pulse range, which can stimulate the synthesis of collagen (in almost all cases) without damaging the surrounding tissues, that is, in a non-ablation mode. But when focusing on a small place, it can also be used for ablation.
In modern cosmetology, neodymium laser is mainly used to remove excess blood vessels (such as spider webs), and it can also be used for photorejuvenation. The technology even has a separate name-non-ablation skin remodeling. In this case, the object affected is hemoglobin. The purpose of this effect is to stimulate the growth of collagen. The heat is generated where the laser radiation is most absorbed (for example, the upper nipple layer) and spreads to nearby tissues. The result is a predictable inflammatory response that causes changes in dermal collagen synthesis, accompanied by skin renewal. Therefore, the laser triggers the formation of young fibroblasts due to partial coagulation of the microvascular bed and partial degeneration of the collagen structure.
I would like to point out in particular that the latest development of laser technology in skin regeneration-the emergence of picosecond laser.
"In 2015, the central theme of all major international laser medicine conferences was the use of picosecond lasers for rejuvenation. This is a new and promising technology that only appeared in 2014 and won the FDAApproved. The working principle of picosecond lasers goes beyond the theory of selective photopyrolysis because they affect tissues not by heating (thermal decomposition) but by instantaneously oversaturating the target with energy.
The picosecond laser generates pulses, the duration of which is in units of trillionths of a second. Such short pulses have no time to cause thermal damage to the tissues, but so much energy is concentrated in the tissues that their targets immediately decompose into particles and form vacuoles. This exposure principle is called photomechanical exposure. In response to the formation of vacuoles in the dermis, the reaction begins, triggering the synthesis of new collagen.
The world's leading experts in laser medicine have provided an independent report on fractional picosecond technology, claiming that the effects of these lasers are comparable to traditional ablation fractional lasers, and there is absolutely no pain for patients. However, for modern urban residents, the most important argument in favor of this technology is the ultra-short recovery time, which requires three to twenty-four hours. It should also be noted that there is no need to spend time for anesthesia before the operation, and because the pulse repetition rate is very high, the procedure itself does not exceed thirty minutes. ”
Skin rejuvenation lasers can be divided into contour lasers and complex multi-function laser systems ("combinations").Each type of device has its advantages and disadvantages, fans and opponents. Many beauticians see more benefits in so-called laser harvesters.
"The modular platform can gradually expand the functions of the beautician by purchasing other accessories. Each nozzle has its own transmitter type, and it is always cheaper to buy a nozzle than to buy a separate device. It should be remembered that, This modular system enables doctors to use all types of lasers to solve specific problems, instead of using one laser for hair removal and skin rejuvenation at the same time, because the principle of selection means that each wavelength can do one thing well, all othersThe signs are secondary. Therefore, a modular device with attachments was made so that the clinic would not buy 5-6 individual devices, but instead had a modular platform with different laser attachments, and sixCompared with individual lasers, this is always cheaper in terms of money and more reasonable in terms of patient burden, because each laser takes up the most space and can fill up patients up to two or three days a week. "
Some people think that multifunctional devices are not suitable for large clinics where doctors work "on the fly".
"Multifunctional machines have an important shortcoming: the failure of this type of combine will mean that all functions are destroyed immediately, and when there are several experts in the cabin working in different offices, the combine is notAlways a good choice. "
In any case, the right to choose depends on the purchaser, and it depends on many factors: the size of the company, personal information, the number and specialization of doctors, and the funding.
"The argument about the advantages and disadvantages of these two versions is like an argument that smartphones with cameras are better than DSLRs. If you want to take pictures, make calls and surf the Internet at the same time, the choice is obvious. However, if you are a professional photographer, the functions of the mobile phone camera will not meet your needs. "
In order to choose the correct laser rejuvenation machine, experts recommend focusing on the following very important aspects:
- It is necessary to request the clinical trial results of the model from the distributor.
- You should talk to experts in different salons and clinics using the equipment of interest to understand their feedback.
- Generally, serious companies will provide customers with the opportunity to test the equipment by salon experts, so employees and managers will be able to evaluate the effectiveness and advantages of the equipment provided.
- All laser equipment must have a registration certificate from the Ministry of Health and a Gosstandart conformity statement.
- You should be aware of the fact that in some models, the use of the pistol is limited, which means an additional charge. Therefore, you should ask the supplier to provide a document confirming the guaranteed number of pulses, instead of following the words of the manager who sold the equipment.
- Make sure to check with the distributor what consumables the equipment (except the pistol) has, how often it must be purchased, how much it costs, and whether it is always in stock.
- Learn how to perform post-warranty maintenance of the equipment under what conditions and within what time frame.
- Find out the personnel and methods of training the experts on the equipment, how many experts can be trained after purchase, under what conditions, whether the training will be repeated, whether the salon experts are replaced, and under what conditions.
Finally, we would like to remind you that the use of laser technology for rejuvenation requires specialists in beauty salons and clinics with medical licenses and the right to use such equipment to provide services-special training under the "Extra Professional Education Standards for Doctors Program"Doctor Laser Medicine".