LASER EQUIPMENT FOR DEVELOPMENT

The first laser (LASER stands for Light Amplification by Stimulated Emissionof Radiation: light amplification using induced (stimulated) radiation) was recently designed and tested for cosmetic purposes (in rubies) only 55 years agoIn 1960. Since then, laser cosmetology has been one of the most sought after areas of aesthetic medicine.

Laser devices have been used with great success to remove epilation, rejuvenation, lifting, blood vessels, age spots, scars, stretch marks, post-acne, tumors, tattoos, vitiligo, psoriasis, pimples, pimples.

Today's review of laser equipment is highly specialized: we introduce readers in detail to skin rejuvenation tools.

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 electric discharge, a flashlight, an arc lamp, another laser, a chemical reaction, and so on. , which activate the working medium with their energy.

Working fluidis ​​the main determinant of the generated wavelength as well as other laser properties (monochrome, coherence, narrow focus). There are hundreds or even thousands of different work surfaces on which a laser can be built. However, the following working media are most commonly used: liquid (consisting of an organic solvent such as methanol, ethanol or ethylene glycol in which chemical dyes are dissolved), gases (gas mixtures such as carbon dioxide, argon, krypton or mixtures such as helium) neonlasers; these lasers are most often pumped by electrical discharges), solids (e. g. , crystals and glass; the solid is usually activated by the addition of small amounts of chromium, neodymium, erbium, or titanium ions); semiconductors.

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

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

Optical resonator, the simplest form of which is located around two parallel mirrors, the working body of the laser. Forced radiation from the working medium is reflected between the mirrors and returned to the working medium, accumulating energy. The wave can be reflected many times before it comes out. More complex lasers use four or more mirrors, which also form an optical resonator but have a more complex structure.

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

Additional devices can be installed in the laser system to achieve various effects, such as rotating mirrors, modulators, filters and absorbers. Their use allows you to change the parameters of the laser radiation, such as wavelength, pulse duration, and so on.

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 milliseconds, nano-, picoseconds.
5. Wavelength measured in micrometers (μm) and nanometers (nm).

Laser radiation acting on the living organism is exposed to the phenomena of reflection, absorption and scattering. 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 a well-defined absorption spectrum. The ability of a particular chromophore to absorb light of different wavelengths at different intensities is determined by the absorption spectrum. The unit of ability of a chromophore to absorb laser light is the absorption coefficient.

The absorption spectra of different chromophores are radically 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 designed chromophore.

Therefore, there is no single universal wavelength, i. e. a laser for all indications (assignments). So the hair removal laser cannot rejuvenate the skin and vice versa. Of course, it is often the case that laser instructions indicate multiple purposes, but in reality there will only be one problem with effectively solving such equipment.

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

METHOD OF GENERATION OF LASER RADIATION

There arepulsed and cw lasersthat generate radiation. Depending on the pumping mode, continuous and pulsed laser radiation may occur. Pulsed light is generated as a wave beam that is interrupted for a specified period of time. Other lasers generate continuous light, and a special device breaks this light into short pieces. As a general rule, continuous-generated radiation lasers have, in addition to physiotherapy lasers, the properties of unwanted heat generation 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 radiating power of medical (especially cosmetic) lasers varies widely, depending on the purpose of the application. For continuously pumping lasers, the power can vary between 0, 01 and 100 W. Pulsed lasers are characterized by pulse power and pulse duration. The power of pulsating lasers is several orders of magnitude higher. Thus, a neodymium laser generates a pulse of energy E = 75 J with a duration of t = 3x10-12 s. Pulse power: P = E / t = 2. 5x1013 W (for comparison: the power of the hydropower plant is about 109 W).

In cosmetology practice, including skin rejuvenation procedures, laser radiation is used using both low power (low intensity laser radiation, LILI) and high (high intensity laser radiation, VILI).

Low Intensity Laser Radiation (LLLT)

The activity of LLLT is the activation of cell membrane enzymes and the stabilization of lipids. LLLT is known to stimulate cell division and development. The effect occurs at a fine, atomic-molecular level, where energy is absorbed by laser radiation at a certain frequency (usually in the red and infrared range). Such energy uptake leads to a sharp increase in the intracellular concentration of Ca2 +, i. e. activation of ATP accumulation and release, restoration of cell membranes, increase of intracellular metabolism and activation of cell proliferation due to regeneration processes. Old cells are intensively replaced with new ones, and the biorhythm of this process is restored. The therapy uses low intensity lasers (with an intensity of 0. 1 to 10 W / cm2). The maximum wavelength of therapeutic lasers is 1300 nm. Diode lasers are especially used for skin rejuvenation procedures:

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

Therapeutic laser treatments are painless and comfortable for the patient due to their low intensity. In some cases, you may feel a slight warmth. There is no rehabilitation period, however, a procedure and supportive procedures are needed to achieve any pronounced effect (improving skin elasticity and firmness, microrelief, hydration, and skin lift).

The basic set of therapeutic lasers includes a device that is combined with a control panel (sometimes in the form of a touch screen) and a handpiece emitter. The kit may include multiple radiators (such as a large work surface for working on the body and a small area for working on the face) as well as fixings for various procedures. Therapeutic lasers are small in size, have low energy consumption, and are able to install the working medium directly into the handpiece without the use of a light guide device to emit radiation.

High Intensity Laser Radiation (Round)

High-intensity laser radiation (2500 J / cm2) allows significant energy to be concentrated in a small volume, causing local thermal heating, rapid evaporation, and hydrodynamic explosion in a biological environment. VILI is widely used in cosmetics, one of which is skin rejuvenation.

Skin rejuvenation with high-intensity laser radiation is a modern way to increase, remove and / or reduce wrinkles and improve skin quality. For high-intensity laser rejuvenation, devices are used whose radiation is well absorbed by water (since 77 percent of the skin is water). The purpose of using such lasers is to rapidly increase the temperature in the absorption range of the laser pulse by immediately evaporating the tissue.

Among high-intensity laser devices for skin rejuvenation, professionals usually distinguish between two main tools:non-ablativeandablative methods.

Ablation - evaporation of surface tissues by laser exposure.

Laser ablative devicesAThey are extremely effective in combating age-related skin changes: the breakdown of collagen and elastin - structural proteins in the skin that provide firmness and elasticity. Traumatic laser treatments are used to trigger regenerative processes. Moreover, it should be noted that the stronger the injury, the stronger the rejuvenating effect, however, of course, the longer the rehabilitation period and the higher the risk of side effects.

Therefore, the main trends in the development of modern skin rejuvenation lasers are the search for a compromise, the attempt to find a way to minimize skin trauma while getting a strong response to the regenerative response.

Modern ablative tools include:

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

The term "fraction" should be clarified immediately.

A fractional laser differs from a conventional laser in that the laser beam is forcibly divided into a plurality of microsignals ("fractions"). This can be done in hardware in several ways:

1. using microlenses placed in the handpiece (a large number of beams touch the skin at once);
2. in scanner mode, where a laser beam perforates the skin one after the other;
3. with roller mounting, which is controlled by laser pulses and allows the procedure to be performed in motion.

This leads to the fact that in a given area of ​​the skin, the laser effect will not be complete but zonal: it is not the entire surface of the skin but thousands of micro-forces that will remain intact, between which intact tissue will remain. Fractional lasers are less traumatic: during tissue processing, they do not cover the entire surface of the skin, but 3 to 70 percent, depending on the laser settings, while triggering a recovery mechanism throughout the area.

In fact, with the advent of fractional lasers, a new era in laser cosmetology has begun: laser procedures are less painful, safer ("more delicate"), and the post-procedure rehabilitation period has been significantly reduced (from two days to a week). At the same time, clinical efficacy did not decrease but, on the contrary, increased.

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

There are a number of fractionated carbon dioxide devices on the market that have adjustable flux density and pulse duration. This allows the temperature and depth of heating of the dermis to be selected. Thanks to new technologies, the total recovery time after the procedure has been reduced to one week. Companies - Distributors of modern carbon lasers have started to advertise their procedures as “weekend” rejuvenation procedures, as the “acute” rehabilitation period (intensive edema and erythema) during fractional laser photothermolysis takes place over two days off and can be sick on Mondays. to work.

The erbium laser has a wavelength of 2. 94 microns and a much higher absorption coefficient than the carbon dioxide laser. Erbium laser radiation penetrates to a depth of about 1 micron, causing the thin layer of the epidermis to evaporate rapidly, 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 upper layer of the epidermis evaporates without a trace. This laser is excellent for rejuvenating scars, smoothing scars, removing pigmentation.

Nowadays, erbium lasers are actively used when working with the most sensitive areas: neck and décolletage, paraorbital and periorbital areas. With this laser, individual points can be processed multiple times, while the doctor is able to monitor the entire "grinding" process. Erbium lasers are actively used intraoperatively by plastic surgeons. Erbium lasers are also preferred if the patient is not ready for long-term rehabilitation.

non-ablative high intensity lasersdo not operate on 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, a laser with a large depth of penetration into the tissue is usually chosen. In this category, theneodymium (Nd: YAG) laser(neodymium-doped yttrium aluminum garnet crystal) with a wavelength of 1064 nm, corresponding to the near-infrared spectrum, is primarily used for rejuvenation.

Radiation from such a laser can penetrate the dermis to a depth of 5 mm. For skin rejuvenation, this laser is usually used in the range of millisecond and nanosecond pulses, which allows the stimulation of collagen synthesis (in almost all cases) without damaging the surrounding tissues, i. e. in a non-ablative mode. But if you focus in a small space, it can also be used for ablation.

In modern cosmetology, the neodymium laser is used primarily to remove unwanted blood vessels such as spider veins, but also for photorejuvenation. The technique even has a separate name -non-ablative dermal transformation. In this case, the object of influence is hemoglobin. The purpose of the action is to stimulate the growth of collagen. The heat is generated where the laser radiation is best absorbed, such as in the upper papillary layer, and spreads to nearby tissues. The result is a predictable inflammatory response that alters skin collagen synthesis 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 initiates the formation of young fibroblasts.

I would like to mention in particular the latest developments in skin rejuvenation laser technologies - the advent of picosecond lasers.

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

The picosecond laser generates pulses, the duration of which is measured in seconds in trillion seconds. Such short pulses do not have time to cause thermal damage to the tissues, but so much energy is concentrated in them that their target immediately disintegrates into microparticles, forming vacuoles. This principle of exposure is called photomechanical exposure. The formation of vacuoles in the skin layer triggers a reaction that initiates the synthesis of new collagen.

The world’s leading laser physicians, in independent reports on fractionated picosecond technology, claim that these lasers provide a similar effect to traditional ablative fractionated 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 spend time on anesthesia before the procedure, and the process itself takes up to thirty minutes due to the very high heart rate. "

Skin rejuvenation lasers can be divided into profile lasers and complex multifunctional laser systems ("combiners").Every piece of equipment has its pros and cons, fans and opponents. Many beauticians see several benefits in the so-called laser combine.

“The modular platform allows the beautician to gradually expand his skills by purchasing 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 recalled that such modular systems allow the physician to have all types of lasers to solve certain problems and not use a laser for both hair removal and rejuvenation because the selective principle means that each wavelength will do one thing. tennijó, and all other indications are secondary. Therefore, modular devices were made with attachments so that the clinic did not purchase 5-6 separate devices but had a modular platform with different laser fixings, and this is always cheaper and more rational in terms of patient load than six separate lasers that occupy each location, andit is loaded with patients for up to two to three days a week. "

Some people think that the multifunctional device is not suitable for large clinics where doctors work “on the fly”.

"Multifunction machines have one major drawback: the failure of such a combine means the breakdown of all functions at once, and the combine is not always a good choice for situations where there are multiple professionals in the cabin" in different offices ". "

In any case, the choice depends on the customer and depends on many factors: the size and profile of the company, the number and specialization of doctors, the funding.

“Discussing the pros and cons of the two versions is like arguing about the pros and cons of a camera smartphone over a DSLR. If you want to take photos, make phone calls and surf the internet at the same time, the choice is obvious. But if you’re a professional photographer, the capabilities of a phone camera will hardly be enough for you. "

In order to make the right choice for your laser rejuvenation machine, experts suggest that you focus on the following very important aspects:

1. Distributors should be asked for the results of clinical trials of the model.
2. Talk to professionals from different salons and clinics who work on the equipment you are interested in and find out their feedback.
3. As a general rule, serious companies will provide customers with the opportunity for salon professionals to test the device so employees and administration will be able to assess the efficiency and benefits 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. Please note that some models have a limited lifetime for manipulations, which incurs additional costs. Therefore, you should ask the supplier to submit a document confirming the guaranteed number of pulses and not be guided by the words of the manager selling the device.
6. Be sure to check with your dealer to see what consumables the device has (in addition to manipulations), how often to buy it, how much it costs, and whether it’s always in stock.
7. Find out how, under what conditions, and in what time frame the device is serviced after warranty.
8. Find out who and how professionals are trained to work on this tool, how many professionals can be trained at the time of purchase, under what conditions, will the training be repeated if the salon professionals change and under what conditions.

In summary, we would like to remind you that the use of laser techniques for rejuvenation in beauty salons and clinics requires a medical license and professionals who are entitled to provide services using devices in this class - doctors who have undergone special training in ""Laser medicine" under the standard program of additional professional training for doctors.