LASER EQUIPMENT FOR REJUVENATION

The first laser (LASER is an abbreviation of EnglishLight amplification by stimulated radiation emission: light amplification using induced (stimulated) radiation)for cosmetic purposes (ruby) wasdesigned and tested recently, just 55 years ago, in 1960. Since then, laser cosmetology has been one of the most demanded areas of aesthetic medicine.

Laser devices are used with great success for hair removal, rejuvenation, lifting, removal of blood vessels, age spots, scars, stretch marks, post-acne, neoplasms, tattoos, for the treatment of vitiligo, psoriasis, acne (acne), ingrown nails.

Today's analysis of laser equipment is highly specialized: we will familiarize readers in detail with devices for skin rejuvenation.

LASER DEVICE

The laser consists of three main elements:

• energy source (or "pumping" mechanism);
• working body (active environment);
• mirror system (optical resonator).

The energy sourcecan be an electrical discharge, a flash lamp, an arc lamp, another laser, a chemical reaction, etc. , which activates the work environment with its energy.

The working fluidis ​​the main determinant of the generated wavelength, as well as other properties of the laser (monochrome, coherence, narrow focus). There are hundreds or even thousands of different working bodies on which a laser can be built. However, the following working media are used most often: liquid (consists of an organic solvent, for example, methanol, ethanol or ethylene glycol, in which chemical dyes are dissolved), gases (a mixture of gases, for example)example: carbon dioxide, argon, krypton or mixtures such as neon heliolasers; these lasers are most often pumped by electrical discharges), solids (such as crystals and glass; solid materials are generally activated by adding small amounts of chromium ions, neodymium, erbium or titanium); semiconductors.

Therefore, according to the type of working medium (active medium), lasers are divided into:

gas
• ;
• liquid (in inorganic or organic dyes);
• metal vapor lasers;
• solid (crystals, glass);
• semiconductor (or diode).

Optical resonator, whose simplest form is two parallel mirrors, is located around the laser working medium. The forced radiation from the work environment is reflected between the mirrors and back to the work environment, accumulating energy. The wave can be reflected many times before leaving. In more complex lasers, four or more mirrors are used, which also form an optical resonator, but with a more complex design.

The quality of manufacture and installation of these mirrors is one of the most important conditions for the quality of a laser system.

In addition, additional devices can be fitted to the laser system to obtain various effects, such as rotating mirrors, modulators, filters and absorbers. Its use allows changing the parameters of laser radiation, for example, wavelength, pulse duration, etc.

TECHNICAL PARAMETERS OF LASER EQUIPMENT

Laser energy parameters:

1. Power, measured in watts (W).
2. Energy, measured in joules (J).
3. Energy density (J / cm2).
4. Pulse duration, measured in milli-, nano-, picoseconds.
5. Wavelength, measured in micrometers (μm) and nanometers (nm).

Laser radiation, acting on a living organism, is subject to the phenomena of reflection, absorption, scattering. The degree 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 a well-defined absorption spectrum. The ability of a chromophore to absorb light of different wavelengths at different intensities is determined by the absorption spectrum. The unit of measurement for a chromophore's ability to absorb laser light is the absorption coefficient.

The absorption spectra of different chromophores differ radically. Therefore, it is important that the wavelength of the laser radiation matches the wavelength at the peak of the absorption capacity of the chromophore that is planned to be exposed.

Therefore, there is no universal wavelength, that is, a laser, for all indications (queries). Therefore, a laser for hair removal cannot rejuvenate the skin and vice versa. Of course, it often happens that several purposes are indicated in the laser instructions, but in fact there will only be one problem to effectively resolve such equipment.

The penetration depth of the laser radiation is inversely proportional to the absorption coefficient and, consequently, depends on the wavelength. For different skin chromophores (water, melanin, hemoglobin, oxyhemoglobin), the depth of penetration is also different. For example, in the visible region (0, 38-0, 74 microns, or 380-740 nm), the depth of penetration will be 3-7 mm, in the infrared region (0, 76-1, 5 microns) -from 0, 5 to 1. 5 mm, and in the ultraviolet region (0, 3-0, 5 microns), laser radiation is strongly absorbed by the epidermis and, therefore, penetrates the tissues at a shallow depth, from 0, 2 to0. 4 mm.

METHOD OF GENERATING LASER RADIATION

There arepulsed and cw lasersgenerating radiation. Depending on the pumping method, continuous and pulsed generation of laser radiation can be achieved. Pulsed light is generated as beams of waves that are interrupted for a specified period of time. Other lasers generate continuous light and a special device divides that light into short segments. As a rule, lasers of continuous radiation generated, in addition to physiotherapy lasers, have the property of unwanted heat release at the site of exposure, which can lead to scar changes and damage to the tissues surrounding the site of exposure.

LASER POWER LEVEL

The radiation power of medical lasers (in particular, cosmetics) varies within wide limits, determined by the purpose of their application. 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 pulsed lasers is several orders of magnitude greater. Thus, a neodymium laser generates a pulse with energy of E = 75 J, whose duration is t = 3x10-12 s. Pulse power: P = E / t = 2, 5x1013 W (for comparison: the power of the hydroelectric plant is approximately 109 W).

In cosmetology practice, including for skin rejuvenation procedures, laser radiation is used with both a low power (low intensity laser radiation, LLLT) and high value (high intensity laser radiation, LILI).

LOW INTENSITY LASER RADIATION (LLLT)

The action of LLLT is to activate enzymes in cell membranes and stabilize lipids. LLLT is known to stimulate cell division and development. The effect occurs at the subtle, atomic-molecular level, where energy is absorbed under the influence of laser radiation of a certain frequency (usually in the red and infrared bands). Such energy absorption leads to a marked increase in the intracellular concentration of Ca2 +, that is, there is an activation of the accumulation and release of ATP, the restoration of cell membranes, an increase in intracellular metabolism and an increase in regenerative processes due to the activation ofcell proliferation (division). Old cells are intensely replaced by new ones and the biorhythm of this process is restored. The therapy uses low-intensity lasers (with an intensity of 0. 1–10 W / cm2). The maximum wavelength for therapeutic lasers is 1300 nm. In particular, diode lasers are used for skin rejuvenation procedures:

• emitters with wavelengths of 890 nm and 915 nm (laser rejuvenation);
• low intensity laser with wavelength from 785 to 890 nm (biorevitalization and laser mesotherapy - delivery of active ingredients to the skin by means of LLLT).

Treatments with therapeutic lasers are painless and comfortable for the patient due to their low intensity. In some cases, you may experience mild heat. There is no rehabilitation period, however, to obtain any pronounced effect (improvement of the skin's elasticity and firmness, micro-relief, hydration and lifting of the skin), a course of support procedures and procedures is necessary.

The basic set of therapeutic lasers includes a device combined with a control panel (sometimes in the form of a touch screen) and a handpiece emitter. The kit can include multiple emitters (for example, with a large work surface for working on the body and a small area for working on the face), as well as accessories for various procedures. Therapeutic lasers have small dimensions, low energy consumption and the ability to install the working medium directly on the handpiece, without using a light guide tool to provide radiation.

HIGH INTENSITY LASER RADIATION (WHEEL)

High intensity laser radiation (2500 J / cm2) allows you to concentrate significant energy in a small volume, which causes local thermal heating, rapid evaporation and hydrodynamic explosion in a biological environment. In cosmetology, VILI has the widest application, one of which is skin rejuvenation.

Skin rejuvenation with high intensity laser radiation is a modern method of lifting, removing and / or reducing the depth of wrinkles, improving the quality of the skin. For high-intensity laser rejuvenation, devices are used whose radiation is well absorbed by water (since the skin contains 77% water). The purpose of using such lasers is to rapidly increase the temperature in the absorption region of a laser pulse with instantaneous tissue evaporation.

Among the variety of high-intensity laser equipment for skin rejuvenation, specialists generally distinguish two main types of devices: for thenon-ablativemethod andablativemethod.

Ablation - evaporation of surface tissues through laser exposure.

Laser ablative devicesare extremely effective in combating skin changes related to aging: the breakdown of collagen and elastin - structural proteins in the skin that give it firmness and elasticity. Traumatic laser treatments are applied to trigger renewal processes. In addition, it should be noted that the stronger the injury, the more powerful the rejuvenating effect, but at the same time, of course, the longer the rehabilitation period and the greater the risk of side effects.

That is why the main trends in the development of modern lasers for skin rejuvenation are the search for a compromise, an attempt to find a way to minimize trauma to the skin, but at the same time obtain a powerful response to aregenerative response.

Modern ablative devices include:

• fractional CO2 lasers (carbon dioxide lasers);
• fractional YAG erbium lasers (solid state yttrium-aluminum-garnet crystal laser with erbium ions).

The term "factional" should be clarified immediately.

A fractional laser differs from a conventional laser because the laser beam is forcibly divided into a set of micro-beams ("fractions"). This can be implemented in hardware in several ways:

1. with the help of microlenses installed on the handpiece (large number of beams simultaneously reach the skin);
2. in scanner mode, when a laser beam pierces the skin sequentially;
3. with roller, which is controlled by laser pulses and allows the procedure to be performed in motion.

This leads to the fact that the effect of the laser on a particular area of ​​the skin becomes not total, but zonal: not the entire surface of the skin is exposed to the effect, but thousands of its micro areas, among which remains the tissuenot affected. Fractional lasers are less traumatic: at the time of tissue processing, they do not cover the entire surface of the skin, but from 3 to 70 percent, depending on the laser settings, while triggering the recovery mechanism throughout the area.

In fact, thanks to the advent of fractional lasers, a new era of laser cosmetology has started: laser procedures have become less painful, safer ("delicate"), the rehabilitation period after procedures has significantly decreased (two days to a week). At the same time, clinical efficacy has not decreased, but has instead increased.

Modern carbon dioxide lasersoperate on the principle offractional photothermolysis, which consists of the formation of coagulation microzones in the form of columns perpendicular to the skin surface. The term "photothermolysis" here means destruction of tissue under the influence of temperature, which arose in the process of transferring energy from laser radiation to tissue (photo - light, thermal heating, lysis - destruction). The carbon dioxide laser has a radiation wavelength of 10. 6 microns. When performing the fractional rejuvenation procedure, this laser removes microzones from the skin practically the entire depth of the epidermis (up to 20 microns), while the thermal damage zone extends in the dermis by 150 microns or more, causing the collagen to clot. This leads to the desired effect (reduction of denatured collagen fibers, smoothing of the skin).

There are several fractional carbon dioxide devices on the market today with adjustable flow density and pulse duration. This allows you to select the temperature and depth of heating of the dermis. Thanks to new technologies, the time for a complete post-procedure recovery has been reduced to one week. Companies - distributors of modern carbon dioxide lasers started to announce the procedures carried out with their help as "weekend" rejuvenation procedures, since during fractional laser photothermolysis, the "acute" rehabilitation period (edema and erythema)intense) occurs on two days off and on Monday the patient can go to work.

The Erbium laser has a wavelength of 2. 94 microns and a much higher absorption coefficient than a carbon dioxide laser. The radiation from the Erbium laser penetrates to a depth of about 1 micron, causing rapid vaporization of a thin layer of the epidermis, with virtually no damage to the surrounding tissues.

“The Erbium laser (Er: YAG) is a typical ablative laser. The ablation effect is so pronounced that the top layer of the epidermis evaporates instantly without a trace. This laser is suitable for covering the surface, smoothing scars and removing pigmentation. "

Today, erbium lasers are actively used when working with the most sensitive areas: neck and décolleté, paraorbital and periorbital areas. With this laser, each point can be processed several times, while the doctor has the ability to control the entire "rectification" process. These are erbium lasers that are actively used intraoperatively by plastic surgeons. In addition, erbium lasers are preferred when the patient is not ready for long-term rehabilitation.

High intensity non-ablative lasersdo not work on the principle of evaporation, but on the principle of water heating and coagulation with the formation of new collagen in the affected areas.

To implement the non-ablative method, as a rule, a laser with a great depth of penetration into the tissue is chosen. In this category, for rejuvenation, theneodymium laser (Nd: YAG)(yttrium-aluminum-garnet crystal doped with neodymium), with a wavelength of 1064 nm, which corresponds to the near infrared spectrum, is used mainly.

The radiation from this laser can penetrate the dermis to a depth of 5 mm. For the purpose of skin rejuvenation, this laser is usually used in the pulse range of milliseconds and nanoseconds, which allows to stimulate collagen synthesis (in almost all cases) without damaging the surrounding tissues, that is, in a non-ablative way. But by focusing on a small spot, it can also be used for ablation.

In modern cosmetology, the neodymium laser is used mainly to remove unwanted vessels, such as spider veins, but also for photorejuvenation. The technique still has a separate name -non-ablative dermal remodeling. In this case, the object of influence is hemoglobin. The purpose of the action is to stimulate the growth of collagen. Heat is generated where laser radiation is most absorbed, such as the upper papillary layer, and spreads to nearby tissues. The consequence is a predictable inflammatory response that causes changes in the synthesis of dermal collagen with a concomitant effect of skin renewal. Thus, due to the partial coagulation of the microvascular bed and the partial denaturation of the collagen structure, the laser triggers the formation of young fibroblasts.

I would especially like to look at the latest developments in the field of laser technologies for skin rejuvenation - the emergence of picosecond lasers.

“In 2015, the central theme of all major international conferences on laser medicine was the use of picosecond lasers for rejuvenation. This is a completely new and promising technology that only appeared in 2014 and received FDA approval. The working principle of picosecond lasers goes beyond the theory of selective photothermolysis, as they affect the tissue not by heating (thermolysis), but by instantaneous supersaturation of the target with energy ”.

The picosecond laser generates pulses, the duration of which is measured in trillionths of a second. These short pulses have no time to inflict thermal damage on tissues, but so much energy is concentrated in them that their target instantly disintegrates into microparticles, forming vacuoles. This principle of exposure is called photomechanical exposure. In response to the formation of vacuoles in the dermal layer, a reaction begins that triggers the synthesis of new collagen.

The world's leading specialists in laser medicine, providing independent reports on fractional picosecond technology, claim that these lasers provide an effect comparable to traditional ablative fractional lasers, absolutely painless for the patient. But the most important argument in favor of this technology for a modern metropolitan resident is ultrashort rehabilitation, which takes three to twenty-four hours. It should also be noted that there is no need to waste time on anesthesia before the procedure, and the process itself, due to the very high pulse repetition rate, does not take more than thirty minutes. "

Lasers for skin rejuvenation can be divided into profile lasers and complex multifunctional laser systems ("combinations").Each type of equipment has its pros and cons, fans and opponents. Many cosmetologists see more benefits in the so-called laser harvester.

“The modular platform allows you to gradually expand the capabilities of the beautician with the purchase of other accessories. Each nozzle has its own type of emitter, and buying a nozzle is always cheaper than buying a separate device. It should be remembered that such modular systems allow the doctor to have all types of lasers to solve specific problems, and not to use a single laser for hair removal and rejuvenation, because the selective principle implies that each wavelength will do one thing. good, and all other indications are secondary. Therefore, modular devices with attachments were made so that the clinic would not buy 5-6 separate devices, but had a modular platform with different laser accessories, and this is always cheaper in terms of money and more rational in terms of chargingpatient than six separate lasers, each of which takes up space and is crowded with patients at most two or three days a week. "

Some people think that the multifunctional device is not suitable for large clinics where doctors work "in real time".

"Multifunctional machines have an important disadvantage: breaking such a combine will mean breaking all functions at once, and a combine is not always a good choice for a situation where there areseveral specialists in the cab "in operation" in different offices. "

In any case, the choice is up to the buyer and depends on many factors: the size of the company, the profile, the number and specialization of the doctors, the financing, in short.

“The debate about the advantages and disadvantages of both versions is like discussing the advantages of a smartphone with a camera over a DSLR. If you want to take pictures, connect and browse the Internet at the same time, the choice is obvious. But if you are a professional photographer, the possibilities of the camera phone will hardly be enough for you. "

To make the right choice of laser rejuvenation machine, experts recommend focusing on the following very important aspects:

1. It is necessary to request the results of clinical trials of this model from distributors.
2. You should talk to specialists from different salons and clinics that work with the equipment you are interested in, to know your feedback.
3. As a rule, serious companies offer customers the opportunity to test the device by salon specialists, so that employees and management can assess the effectiveness and advantages of the equipment offered.
4. All laser devices must have a registration certificate from the Ministry of Health and a Gosstandart declaration of conformity.
5. It should be noted that the period of use of the handles on some models is limited, which implies additional costs. Therefore, you should ask the supplier for a document that proves the guaranteed number of pulses, and not be guided by the words of the manager who sells the device.
6. Be sure to check with the distributor what consumables the device has (in addition to the handles), how often they should be purchased, how much they cost and whether they are always in stock.
7. Find out what the post-warranty maintenance of the device will be like, under what conditions and for what period.
8. Find out who is training specialists to work on this device, how many specialists can be trained at the time of purchase, under what conditions the training will be repeated if the specialist team in your salon changes and under what conditions.

In conclusion, we remind you that the use of laser techniques for rejuvenation requires that beauty salons and clinics have medical licenses and specialists entitled to provide services with equipment of this class - doctors who have received special training in the "Standard Education Programadditional professional for medical laser medicine ".