The first laser (LASER is short for EnglishLight Amplificationby Stimulated Emissionof Radiation: amplifies light using induced radiation (stimulated))for the purposecosmetology (in ruby) was recently designed and tested, just 55 years ago, in 1960. Since then, laser cosmetology has been one of the most in demand areas in cosmetic medicine.
Laser devices are very successfully used to depilate, rejuvenate, lift muscles, remove blood vessels, age spots, scars, stretch marks, post acne, cancer, tattoos, toTreatment of vitiligo, psoriasis, acne (acne), ingrown nails.
Today's laser equipment review is highly specialized: we'll familiarize ourselves with skin rejuvenation devices in detail.
The laser is composed of three main elements:
- energy source
- (or "pump" mechanism);
- work body (active environment);
- mirror system (optical resonator).
Energy sourcecan be electric discharge, flash, arc lamp, other lasers, chemical reaction, etc. v. , activating their energetic work environment.
Working liquidis the main determinant of the wavelength produced, as well as other laser properties (monochrome, coherent, narrow focus). There are hundreds or even thousands of different bodies working on that basis that can generate lasers. However, the following working media are most commonly used: liquids (including organic solvents, for example, methanol, ethanol or ethylene glycol, in which chemical dyes are dissolved), gases (mixtures)mixes of gases, for example, carbon dioxide, argon, krypton or mixtures such as neon helilaser; these lasers are usually pumped with electric discharge), solids (such as crystals and glass; solid materials are usually activated byhow small amounts of chromium, neodymium, erbium or titanium ions are added); Semiconductors.
So according to the type of working environment (active environment), the laser is divided into:
- liquid (on inorganic or organic dyes);
- metal vapor laser;
- solid (crystal, glass);
- semiconductor (or diode).
Optical resonator, their simplest form, are two parallel mirrors, placed around the working medium of the laser. The forced radiation of the working environment is reflected between the mirrors and returned to the working environment, accumulating energy. Waves may be reflected several times before being emitted. 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 the manufacture and installation of these mirrors is one of the most important conditions for the quality of the laser system.
In addition, additional devices can be attached to the laser system to obtain various effects, such as rotating mirrors, modulators, filters and absorbers. Their use allows to alter parameters of laser radiation, eg, wavelength, pulse duration, etc. v.
LASER DEVICE SPECIFICATION
Laser energy specification:
- Power, measured in watts (W).
- Energy, measured in joules (J).
- Energy density (J / cm2).
- Pulse duration, measured in milliseconds, nano-, and pico seconds.
- Wavelength, measured in micrometres (μm) and nanometer (nm).
Laser radiation, affecting living organisms, causes reflection, absorption and 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 pigment cells, which are biological structures with well-defined absorption spectra. The ability of a specific color carrier to absorb light of different wavelengths with different intensities is determined by the absorption spectrum. The unit for measuring the ability of a group to absorb laser light is the absorbance coefficient.
The absorption spectrum of different pigment cells is completely different. Therefore, it is important that the wavelength of the laser radiation coincides with the wavelength at the peak of the absorbance capacity of the intended color carrier to be illuminated.
Hence, there is no one common wavelength, ie one laser, for all indications (appointment). Therefore, the laser for hair removal cannot rejuvenate the skin, and vice versa. Of course, quite often happens some of the purposes indicated in laser guidance, but in reality there will only be one problem to effectively deal with that device.
The penetration depth of the laser radiation is inversely proportional to the absorption coefficient and is therefore dependent on the wavelength. For different pigment cells of the skin (water, melanin, hemoglobin, oxyhemoglobin), the depth of penetration is also different. For example, in the visible region (0, 38-0, 74 micron, or 380-740 nm), the penetration depth will be 3-7 mm, in the infrared region (0, 76-1, 5 microns) - from 0. 5 to 15 mm, and in the ultraviolet (0, 3-0, 5 micron), the laser radiation is strongly absorbed by the epidermis and thus penetrates the tissues to a shallow depth, from0. 2 to 0. 1 mm.
LASER CREATION METHOD
Yespulsed lasers and cw lasersthat generate radiation. Depending on the injection method, continuous and pulsed laser radiation may be obtained. The pulsed light is generated as a wave beam that is interrupted for a defined period of time. Other lasers produce continuous light, and a special device divides the light into short segments. As a rule, lasers that generate constant radiation, in addition to physiotherapy lasers, have the properties of undesirable heat release at the site of contact, which can lead to scar alterations and damage to surrounding tissues. contact.
The radiated power of medical lasers (especially aesthetic) varies within the wide range, as determined by the purpose of their application. For lasers with continuous pump, the power can vary from 0. 1 to 100 W. Pulse lasers are characterized by pulse power and pulse duration. The power of the pulsed laser is several steps higher. Therefore, a neodymium laser produces a pulse of energy E = 75 J, the duration of the pulse is t = 3x10-12 s. Pulse power: P = E / t = 2. 5x1013 W (for comparison: the capacity of the hydroelectric station is approximately 109 W).
In cosmetology practice, including skin rejuvenation procedures, laser radiation is used both with low power values (low intensity laser radiation, LLLT) and high (intense laser radiationhigh, LILI).
LOW LASER RANGE (LLLT)
The activity of LLLT is to activate cell membrane enzymes and stabilize lipids. It is known that LLLT stimulates cell division and growth. The effect occurs on a subtle, atom-molecular level, where energy is absorbed under the influence of laser radiation of a certain frequency (usually the red and infrared bands). Such energy absorption leads to a sharp increase in intracellular Ca2 + concentration, i. e. there is an activation of ATP accumulation and release, cell membrane restoration, intracellular metabolism and increased processesregeneration by activating cell proliferation (division). Old cells are forcefully replaced by new ones, and the circadian rhythm of this process is restored. The therapy uses a low-intensity laser (with intensity 0, 1-10 W / cm2). The maximum wavelength for laser therapy is 1300 nm. In particular, diode lasers are used for skin rejuvenation treatments:
- emitters with wavelengths of 890 nm and 915 nm (laser rejuvenation);
- low intensity laser with wavelengths from 785 to 890 nm (biological and intermediate lasers - introducing active ingredients into the skin by LLLT).
Laser therapy is painless and comfortable for the patient due to its low intensity. In some cases, you may feel warmth. However, with no recovery time, to get any noticeable effect (improve skin elasticity and firmness, microrelief, moisturize and lift skin), it is necessary to take a course of application andsupporting materials.
The basic laser treatment set consists of a device combined with a control panel (sometimes in the form of a touchscreen) and a handheld emitter. The kit may include several emitters (for example, with a large work surface area for work on the body and with a small area for work on the face), as well as attachments fordifferent submission. Laser treatment is small in size, low power consumption and the ability to install the working environment directly into the handle without using a light guide tool to emit radiation.
HIGH INTENSITY LASER RANGE (WHEEL)
High intensity laser radiation (2500 J / cm2) allows significant energy concentration in a small volume, causing local heat, rapid evaporation and hydrodynamic explosions in biological environments. In cosmetology, VILI is widely used, one of which is skin rejuvenation.
Skin rejuvenation with intense laser radiation is a modern method for lifting, removing and / or reducing the depth of wrinkles, improving the quality of the skin. For high-intensity laser rejuvenation, such devices are used, the radiation is well absorbed by the water (since the skin is 77% water). The purpose of using such lasers is to rapidly raise the temperature in the laser pulse absorption zone with instantaneous tissue evaporation.
Among the many types of high-intensity laser devices for skin rejuvenation, specialists generally distinguish two main types: fornon-dissectableand ablation.
Cut - volatilize surface tissue by laser irradiation.
Laser cutting equipmentis extremely effective in the fight against age-related changes in the skin: degradation of collagen and elastin - the structural proteins that the skin providesfirmness and elasticity for the skin. Injury laser treatment is applied to trigger the innovation. Furthermore, it should be noted that the stronger the injury, the stronger the rejuvenating effect, but at the same time, the longer the recovery time and the higher the risk of side effects.
That is why the main trends in the development of modern lasers for skin rejuvenation are seeking compromise, trying to find ways to minimize skin injuries, but at the same time get reactive. strong recovery.
Modern extraction devices include:
- fractional CO2 laser (carbon dioxide laser);
- fractional erbium YAG laser (solid state yttrium-aluminum-garnet crystal laser with erbium ions).
The term "faction" needs to be clarified immediately.
Fractional lasers differ from conventional lasers in that the laser beam is forcibly divided into a set of microscopic ("fraction") rays. This can be done in hardware in a number of ways:
- with the help of micro lenses installed in the handle (a large number of rays falling on the skin at once);
- in scanner mode, when a sequence of laser beams fragrance the skin;
- with roller attachment, controlled by laser pulse and allows the process to be performed in motion.
This leads to the fact that the laser effect on a particular skin area becomes not total, but regional: not the entire skin surface exposed to the effect, but thousands of microscopic regionsits tissue, among which the unaffected tissue remains. Fractional lasers are less traumatic: at the time of tissue treatment, they do not cover the entire skin surface but from 3 to 70%, depending on the laser setting, while also activating a full recovery mechanism. area.
In fact, thanks to the advent of fractional lasers, a new era of laser aesthetics has begun: laser procedures become less painful, safer ("delicate"), at timesrecovery time after the procedures was significantly reduced (from two days to a week). At the same time, the clinical effect does not decrease, but on the contrary, increases.
Modern carbon dioxide lasersoperate on the principle offractional photovoltaic, which involves the formation of coagulation microparticles in the form of columns perpendicular to the surface. skin surface. The term "photoothermal" here means tissue damage under the action of temperature, arising during the transfer of laser energy to the tissue (optical - light, heat - heating, lysis -destroy). Carbon dioxide lasers have a radiation wavelength of 10. 6 microns. When performing the fractional rejuvenation procedure, this laser removes the actual skin microscopes at the full depth of the epidermis (up to 20 microns), while the heat lesion extends to the dermis. 150 microns or more, causing collagen coagulation. This leads to the desired effect (reduction of denatured collagen fibers, skin smoothing).
There are a number of fractional carbon dioxide devices on the market today with adjustable flux density and pulse duration. This allows you to choose the temperature and the heating depth of the dermis. Thanks to the new technology, the time for complete recovery from the procedure has been reduced to one week. Modern carbon dioxide laser companies - distributors begin to promote processes implemented with their help such as "weekend" rejuvenation processes, since when conducting laser fractional photothermal activities, The "acute" recovery phase (edema and erythema) will pass on two days off and on Monday the patient is likely to go to work.
Erbium laser has a wavelength of 2. 94 microns and a much higher absorption coefficient than carbon dioxide laser. Erbium laser radiation penetrates a depth of about 1 micron, rapidly evaporates a thin epidermis layer with almost no damage to surrounding tissue.
“The Erbium laser (Er: YAG) is a typical annihilation laser. The ablation effect is so pronounced that the upper layer of the epidermis evaporates immediately without leaving any traces behind. This laser is very suitable for resurfacing, scarring, pigmentation removal. "
Today erbium lasers are actively used when working with the most sensitive areas: the neck and scalp, the eye around the eyes and around the eyes. With this laser, each point can be processed many times, and the doctor has the ability to control the entire "grinding" process. It is the erbium laser that is actively used by cosmetic surgeons in surgery. In addition, the erbium laser is preferred when the patient is not ready for long-term rehabilitation.
Non-dissociation High Intensity Laserdoes not work on the principle of evaporation but rather on the principle of heating water and coagulating with new collagen formation in the affected areas of the skin.
To perform the non-ablation method, as a rule, a laser with a large penetration of tissue is selected. In this category, for rejuvenation, theneodymium (Nd: YAG) laser(a yttrium-aluminum-garnet crystal doped with neodymium), has a wavelength of 1064 nm, which corresponds to a near infrared spectrum. , is used primarily.
Such laser radiation can penetrate the dermis to a depth of 5 mm. For the purpose of skin rejuvenation, this laser is often used in the millisecond and nanosecond pulse bands, which helps stimulate collagen synthesis (in most cases) without damaging surrounding tissues, i. e. non-ripping mode. But when focusing on a small spot, it can also be used to cut out.
In modern aesthetics, neodymium lasers are mainly used to remove unwanted vessels, such as spider veins, but also to rejuvenate with light. This technique even has a proper name -non-dissectable skin regeneration. In this case, hemoglobin is the target. The purpose of action is to stimulate collagen proliferation. Heat is generated where the laser radiation is most absorbed, such as the papillary layer, and spread to neighboring tissues. As a result, the inflammatory response is predictable, causing changes in the collagen synthesis in the skin and the skin renewal effect. Hence, due to partial coagulation of the microchip layer and partial denaturation of the collagen structure, the laser activates the formation of young fibroblasts.
I would particularly like to note the latest developments in the field of skin rejuvenation laser technology - 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, only appeared in 2014 and received FDA approval. The working principle of picosecond lasers goes beyond the theory of selective photoothermal resolution, since they affect tissue not through heating (pyrolysis), but through instant saturation oftargets with energy ”.
Pico-second lasers generate pulses, their duration measured in billionths of a second. Such short pulses do not have time to cause thermal damage to tissues, but so much energy is concentrated on them causing their targets to be immediately decomposed into microspheres, forming vacuoles. This exposure principle is called the mechanical exposure. In response to the formation of vacuoles in the dermis, a reaction begins to trigger new collagen synthesis.
The world's leading experts in laser medicine, providing independent reports on fractional-second picosec technology, confirm that these lasers are as effective as fractional cut-off lasers. system, absolutely painless to the patient. But the most important argument in support of this technology for a modern urban dweller is the extremely short recovery process, which takes three to twenty-four hours. It should also be noted that there is no need for anesthesia before the procedure, and the procedure itself, due to its very high pulse repetition rate, takes no more than thirty minutes. "
Skin rejuvenation lasers can be divided into configurable lasers and complex ("combined") multifunctional laser systems.Every type of device has its pros and cons, fans and competitors. Many cosmetologists see more benefits in so-called laser harvest machines.
“The modular platform makes it possible to gradually expand the beautician's capabilities by purchasing other attachments. Each injector has its own type of generator, and it is always cheaper to buy one than to buy a separate device. It should be remembered that such modular systems allow the physician to have all types of lasers to solve specific problems, and not to use a single laser for both hair removal and rejuvenation, because rawSelective switches imply that each wavelength will do one thing. well, and all other indications are secondary. Consequently, modular units with attachments are made so that the clinic does not buy 5-6 separate units but has a modular platform with different laser accessories, and this is always cheaper in terms ofmore money and more reasonable in patient population than six separate lasers, each occupying space and having the most patients two or three days a week. "
Some people think that this multifunction device is not suitable for large clinics where doctors do "live" work.
"Multi-function machines have one important drawback: the failure of such an association would mean crashing all functions at once and a combination is not always an option. Good choice for situations where there are a number of specialists in the cabin "on duty" 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 quantity and the doctor's expertise, the budget, ultimately.
“The debate over the pros and cons of both versions is like the debate over the advantages of a smartphone with a camera over a DSLR. If you want to take pictures, make phone calls and surf the Internet at the same time then the choice is obvious. But if you are a professional photographer, then the capabilities of the phone camera will be difficult to satisfy enough for you.
In order to choose the right laser rejuvenation machine, experts recommend focusing on the following very important aspects:
- The clinical trial results of this model should be requested from a distributor.
- You should speak with professionals from different salons and clinics working on the equipment of interest, to find out their feedback.
- As a rule, companies seriously offer customers the opportunity to inspect equipment by salon specialists, so that staff and management can evaluate the effectiveness and advantages of the equipment. be provided.
- All laser equipment must have a registration certificate from the Ministry of Health and a declaration of compliance with State Standards.
- Please note that the duration of the operations on some models is limited, which means an additional fee. Therefore, you should ask your supplier to confirm the guaranteed pulse count, not verbal instructions from the person selling the device.
- Be sure to check with your distributor what consumables (apart from operations) are included in the equipment, how often they should be purchased, how much they cost, and if they are always in stock.
- Find out how your device's post-warranty maintenance will occur, under what conditions, and for what timeframe.
- Find out who and how are training professionals to work on this device, how many professionals can be trained when purchasing, under what conditions, whether the training is repeatable, if the staff of specialists in your salon changes and what conditions.
To summarize, we reiterate that the use of laser technology for rejuvenation requires licensed salons and clinics and specialist physicians to provide services. equipment of this class - the physician has received special training under the "Professional Complementary Training Standard Program for Laser Physicians".