LASER EQUIPMENT FOR REJUVENATION

Laser skin rejuvenation

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

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

Today's review of laser equipment is highly specialized: we will introduce readers in detail to the 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 electric discharge, a flash lamp, an arc lamp, another laser, a chemical reaction, etc. , which activate the means of work with their 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 the basis of which a laser can be built. However, the following working media are most often used: liquid (consisting of an organic solvent, for example, methanol, ethanol or ethylene glycol, in which chemical dyes are dissolved), gas (a mixture of gases, for example: carbon dioxide, argon, krypton or mixtures such as neon heliolaser; these lasers are most often pumped by electrical discharges), solids (such as crystals and glass; solid materials are usually activated by the addition of small amounts of chromium, neodymium, erbium ionsor titanium); semiconductors.

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

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

Optical resonator, whose simplest form is two parallel mirrors, is located around the working body of the laser. The forced radiation from the working medium is reflected between the mirrors and back into the working medium, accumulating energy. The wave can be reflected many times before it goes out. In more complex lasers, four or more mirrors are used, which also form an optical resonator, but of 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.

Additionally, additional devices can be mounted 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 laser radiation, for example, wavelength, pulse duration, etc.

TECHNICAL PARAMETERS OF THE 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).

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

The absorption spectra of various chromophores differ radically. 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 that is expected to be exposed.

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

The depth of penetration 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) - from0. 5 to 1. 5 mm, and in the ultraviolet region (0. 3-0. 5 microns), laser radiation is strongly absorbed by the epidermis and thus penetrates the tissues to a small depth, from 0. 2 to 0, 4 mm.

METHOD OF GENERATION OF LASER RADIATION

There arepulsed and cw lasersthat generate radiation. Depending on the pumping method, continuous and pulsed generation of laser radiation can be achieved. Pulsed light is generated as wave beams that are interrupted for a specified period of time. Other lasers generate continuous light and a special device divides this light into short segments. As a rule, continuous generated radiation lasers, in addition to physiotherapy lasers, have the property of releasing unwanted heat 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, cosmetic) varies within wide limits, determined by the purposes of their application. For continuously pumped lasers, the power can range from 0. 01 to 100 W. Pulsed lasers are characterized by the power and pulse duration. The power of pulsed lasers is several orders of magnitude higher. Therefore, a neodymium laser generates a pulse with an energy of E = 75 J, the duration of which is t = 3x10-12 s. Impulsive power: P = E / t = 2. 5x1013 W (for comparison: the power of the hydroelectric plant is about 109 W).

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

LOW INTENSITY LASER RADIATION (LLLT)

The action of LLLT is to activate cell membrane enzymes and stabilize lipids. LLLT is known to stimulate cell division and development. The effect occurs at a subtle, atomic-molecular level, where energy is absorbed under the influence of laser radiation of a certain frequency (usually in the red and infrared ranges). Such energy absorption leads to a sharp 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 dueactivation of cell proliferation (division). The 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, 1-10 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 a wavelength of 785 to 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, to achieve a pronounced effect (improvement in skin elasticity and firmness, micro-relief, hydration and skin lifting), a course of supportive procedures and procedures is required.

The basic set of therapeutic lasers comprises a combined device with a control panel (sometimes in the form of a touchscreen display) and a handpiece-emitter. The kit may include several emitters (for example, with a large work surface for working on the body and with a small area for working on the face), as well as attachments for various procedures. Therapeutic lasers have small dimensions, low energy consumption and the possibility of installing the working medium directly in the handpiece, without using a light guide tool to deliver the radiation.

HIGH INTENSITY LASER RADIATION (ROTATE)

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

Skin rejuvenation using high intensity laser radiation is a modern method to lift, remove and / or reduce the depth of wrinkles and improve skin quality. For high-intensity laser rejuvenation, those devices are used, the radiation of which is well absorbed by water (since the skin is made up of 77% water). The purpose of using such lasers is a rapid increase in temperature in the absorption region of a laser pulse with instant evaporation of the tissue.

Among the variety of high-intensity laser equipment for skin rejuvenation, specialists usually distinguish two main types of devices: fornon-ablativeandablative method.

Ablation - evaporation of surface tissues by laser exposure.

Devices for laser ablationare extremely effective in the fight against age-related skin changes: the degradation of collagen and elastin, the structural proteins of the skin that give it firmness and elasticity. Traumatic laser treatments are used 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 skin rejuvenation lasers are the search for a compromise, the attempt to find a way to minimize trauma to the skin, but at the same time achieve a powerful response to aregenerative response.

Modern ablative devices include:

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

We need to clarify the term "faction" right away.

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

  1. with the help of microlenses installed in the handpiece (a large number of rays fall on the skin at the same time);
  2. in scanner mode, when a laser beam sequentially pierces the skin;
  3. with roller attachment, which is controlled by laser pulses and allows you to perform the procedure on the go.

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, but thousands of its micro-areas, among which tissue remainsnot interested. 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, activating the recovery mechanism throughout the area.

In fact, thanks to the advent of fractional lasers, a new era of laser cosmetology has begun: laser procedures have become less painful, safer ("delicate"), the rehabilitation period after the procedures has been significantly reduced (from two days to a week). At the same time, the clinical efficacy did not decrease, but, on the contrary, increased.

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

Numerous fractional carbon dioxide devices with adjustable flux density and pulse duration are available on the market today. This allows you to select the temperature and depth of heating of the dermis. Thanks to new technologies, the time for a full post-procedural recovery has been reduced to one week. Companies - distributors of modern carbon dioxide lasers have begun to advertise the procedures performed with their help as "weekend" rejuvenation procedures, since during fractional laser photothermolysis, the "acute" rehabilitation period (intense edema and erythema) takes placein 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 erbium laser radiation 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 upper layer of the epidermis instantly evaporates without leaving traces. This laser is suitable for resurfacing, smoothing scars, 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 possibility to control the entire "grinding" process. It is the erbium lasers that are actively used during surgery by plastic surgeons. Additionally, erbium lasers are preferred when the patient is not ready for long-term rehabilitation.

Non-ablative high-intensity lasersdo not work on the principle of evaporation, but on the principle of heating water 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 large depth of penetration into the tissue is chosen. In this category, theneodymium laser (Nd: YAG)(neodymium-doped yttrium-aluminum-garnet crystal) is mainly used for rejuvenation, which has a wavelength of 1064 nm, which corresponds to the near infrared spectrum.

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

In modern cosmetology, the neodymium laser is mainly used to remove unwanted vessels, such as spider veins, but also for photorejuvenation. The technique also has a separate name:non-ablative dermal reshaping. 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 the laser radiation is most absorbed, such as the upper papillary layer, and spreads to neighboring tissues. The consequence is a predictable inflammatory response that causes changes in dermal collagen synthesis with a concomitant skin renewal effect. Therefore, 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 particularly like to highlight 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 principle of operation of picosecond lasers goes beyond the theory of selective photothermolysis, since they act on the tissue not through heating (thermolysis), but through the instantaneous supersaturation of the target with energy ”.

The picosecond laser generates pulses, the duration of which is measured in trillionths of a second. Such short pulses don't have 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 exposure principle 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 experts in laser medicine, who provide independent reports on fractional picosecond technologies, claim that these lasers provide an effect comparable to traditional ablative fractional lasers, absolutely painless for the patient. But the most important argument for this technology for a modern metropolitan resident is the very short rehabilitation, which takes three to twenty-four hours. It should also be noted that it is not necessary to spend time on anesthesia before the procedure and the process itself, due to the very high pulse repetition rate, takes no more than thirty minutes. "

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

“The modular platform allows you to gradually expand the capabilities of the beautician by purchasing additional attachments. 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 kinds of lasers to solve specific problems and not to use a laser for both hair removal and rejuvenation, because the selective principle implies that each wavelength will do a good thing, andall other indications are secondary. Therefore, modular devices with attachments were made so that the clinic did not buy 5-6 separate devices, but had a modular platform with several laser attachments, and this is always cheaper in terms of money and more rational in terms of load. of the patient compared to six separate lasers, each of which occupies space and is loaded with patients at most two or three days per week ".

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

"Multifunctional machines have an important disadvantage: a failure of such a combine will result in the failure of all functions at once, and a combine is not always a good choice for a situation where there are several specialists in the cabin"in operation" in several 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 doctors, the financing, in the end.

“The debate on the advantages and disadvantages of both versions is like arguing about the advantages of a smartphone with a camera over a DSLR. If you want to take photos, call and surf the Internet at the same time, the choice is obvious. But if you are a professional photographer, the phone's camera capabilities 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. Clinical trial results of this model should be obtained from distributors.
  2. You should talk to specialists from different salons and clinics working on the equipment of interest, find out their feedback.
  3. As a rule, serious companies offer customers the opportunity to test the device by salon specialists, so that employees and administration can evaluate the effectiveness and benefits of the equipment offered.
  4. All laser devices must have a registration certificate from the Ministry of Health and a declaration of conformity to the state standard.
  5. Please note that the term of use of the handpieces in some models is limited, this implies additional costs. Therefore, it is necessary to ask the supplier to provide a document confirming the guaranteed number of pulses and not to be guided by the words of the manager who sells the device.
  6. Be sure to check with your distributor what consumables the device has (in addition to the handpieces), how often they will need to be purchased, how much they cost and whether they are always available.
  7. Find out how post-warranty maintenance of your device will take place, under what conditions and over what time frame.
  8. Find out who and how training specialists have to work on this device, how many specialists can be trained at the time of purchase, under what conditions, whether the training will be repeated, whether the staff of specialists in your salon changes and in whichconditions.

In conclusion, we remind you that the use of laser techniques for rejuvenation requires that beauty salons and clinics have a medical license and specialists who have the right to provide services using equipment of this class - doctors who have followedspecial training under the "Standard additional vocational training program for laser medicine".