Salon laser hair removal machine is an instrument that uses the principle of selective thermodynamics to select the appropriate power, energy density and light spot to treat excess hair according to the different characteristics of the patient.
Laser hair removal methods can be divided into 3 categories:
1. Laser non-selective damage hair removal method, such as CO2 laser hair removal is time-consuming and easy to form scars;
2. Photodynamic therapy, such as oral or topical use of α-aminocaproyl propionic acid followed by laser irradiation, this method seems feasible in theory, but it has very few clinical applications;
3. Selective photothermal effect hair removal, namely professional ipl hair removal machine and shr hair removal machine.
The principle of modern salon laser hair removal machine is based on the principle of "selective photopyrolysis" proposed by American doctors Aderson and Parrish in 1983: a certain wavelength of laser light penetrates the epidermis, enters the dermis, and is selectively covered by hair and The melanin particles in the hair follicle are absorbed, and the professional ipl hair removal machine produces a photothermal effect. The heat energy in the hair is conducted to the surroundings, completely destroying the "hair roots" such as hair follicles and stem cells, resulting in permanent hair removal. The normal tissue around the hair follicle does not contain melanin particles, so it does not absorb this laser, so the impact is small and generally does not cause paralysis.
Laser and light source of Salon laser hair removal machine
When Ipl machines for salons use the principle of "selective photopyrolysis" to perform laser hair removal, the laser wavelength and pulse width should ensure that the laser hits the hair follicles without damaging adjacent tissues. Clinical studies have shown that the longer the wavelength, the deeper the penetration, the smaller the scattering, but the poorer the absorption of melanin, so the energy must be enhanced, but the epidermis should not be damaged; the pulse width is smaller than the TRT (thermal relaxation of the hair follicle) Time) is effective, and TRT larger than the epidermis is safe; the larger the spot size, the deeper the penetration; at the same time, active skin cooling should be used to protect the epidermis and relieve pain. When the wavelength is less than 600nm, the laser is mainly absorbed by hemoglobin and protein, and when the wavelength is greater than 1100nm, the laser is mainly absorbed by the moisture in the body tissues. When the wavelength of professional ipl hair removal machine is in the range of 600nm~1100nm, the light is transparent. Therefore, people usually choose lasers with a wavelength in the range of 600nm~1100nm for hair removal. The laser and strong pulse light source used for hair removal mainly include long pulse laser (694nm), long pulse alexandrite laser (755nm), semiconductor laser (800nm), long pulse Nd:YAG laser (1064nm), strong pulse incoherent broadband Light source (590~1200nm), etc.
1. Long pulse laser
The 694nm laser is strongly absorbed by melanin. This kind of laser has 15%~20% energy to penetrate the entire dermis, and the hair with melanin in the dermis and deep layers can absorb the energy of the laser, causing the hair follicles to overheat and be damaged. The normal tissue around the hair follicle has a very low light absorption rate of 694nm. When the pulse width is constant, the selective photothermal damage to the hair follicle can be achieved without damaging the surrounding normal tissue.
2. Long pulse alexandrite laser
The 755nm alexandrite laser is very similar to the laser, except that it has a slightly stronger penetrability and a lower melanin absorption rate because it has a slightly longer wavelength.
3. Semiconductor laser
The penetration depth of the semiconductor laser system in the skin tissue is deeper, more than 5mm, and the range of action can reach the deep dermis and subcutaneous fat tissue. It can effectively penetrate the epidermis to reach the hair follicle tissue of the dermis, thereby destroying hair in any part and depth of the human body. The epidermis absorbs very little laser energy, so it does not produce pigmentation.
4. Long pulse Nd: YAG laser hair removal machine
The long-pulse Nd: YAG laser hair removal machine has a wavelength of 1064nm and can penetrate 5~7mm. Due to the low affinity of melanin for the 1064nm laser, exogenous color bases (such as carbon smears) are often used for treatment. The laser spot scans the entire treatment area until the visible carbon particles are removed. The disadvantage is that sometimes the carbon particles cannot reach the hair bulb and affect the treatment effect. For example, sweat glands and sebaceous glands are easily damaged if they are contaminated with carbon particles, and the clinical effect is not ideal. Recently, it has been clinically reported to use a long pulse width laser with a wavelength of 1064nm to remove hair without using carbon smear before surgery. Because epidermal melanosomes are very sensitive to short pulse width (<1ms) lasers, and long pulse width (≤200ms) lasers, high-energy lasers can be used to effectively heat the inner and outer hair root sheaths and hair growth areas without affecting Epidermal melanosomes, so it can be safely used for the treatment of black skin.
5. shr laser hair removal machine- strong pulsed light
Shr laser hair removal machine is not a laser light source, but a non-continuous, multi-wavelength combination light source. Its wavelength is between 550 and 1200 nm and can penetrate 1.3 mm. The treatment parameters can be adjusted according to skin color or hair color. . Theoretically speaking, the broad-spectrum wavelength light source system increases the absorption of light by non-target targets, and therefore also increases the adverse reactions.
Features of Ipl laser hair removal machine
1. Long pulse laser: The wavelength is 694m, which is the shortest wavelength among clinical hair removal lasers (it is not commonly used at present). The wavelength is short and the penetration depth is limited. It is suitable for patients with light skin and dark hair, but it has limited effect on the deeper parts of the hair follicle. With strong melanin selective absorption performance, energy is not only absorbed by the melanin in the hair follicles, but also by the melanin in the epidermis, which is easy to cause epidermal damage.
2. Long-pulse alexandrite laser: wavelength 755nm, penetration depth is deeper than laser, it is a common hair removal laser in clinic, with good therapeutic effect, relatively few and short-lived adverse reactions, erythema reaction, skin pigmentation, folliculitis, etc. , It is mainly seen in patients with darker skin or not applied cold compresses to the treated area after the hair removal operation.
3. Semiconductor laser: The wavelength is 800nm, which is one of the ideal laser hair removal systems with the most clinical applications. The penetration depth is deeper than the laser and emerald laser, and the hair follicle melanin absorbs photons at 800 nm relatively strongly, which can effectively destroy the hair follicle. Compared with red and alexandrite lasers, epidermal melanin absorbs less energy from the semiconductor 800nm laser and has relatively few adverse reactions. Semiconductor laser has low cost, high reliability and small size.
4. Long pulse laser: The wavelength is 1064nm, the penetration is deeper, so it is especially suitable for patients with darker skin. The absorption of melanin at this wavelength is reduced, the hair follicles cannot be completely destroyed, and the hair will continue to grow. At the same time, the melanocytes of the hair follicles are destroyed, and the melanin production is reduced, causing the part of the hair that grows to become white. Therefore, high energy is needed to destroy the hair follicles during treatment. .
5. High-intensity pulsed light: The high-intensity pulsed light of shr hair removal machine is not a laser light source, but a non-continuous, multiple-wavelength combination light source with a wavelength of 550-1200m. Its cooling system is good, and the skin trauma probability Low, side effects are also small. It takes multiple treatments to achieve the hair removal effect, and the hair removal effect is slightly inferior to that of laser.
Salon laser hair removal machine factors that affect the effect of hair removal
1. The choice of laser type (ie wavelength) of ipl hair removal machine: When choosing what wavelength of hair removal laser, two factors need to be considered, one is the penetration depth of the laser; the other is the selectivity of target absorption. Because the hair bulb is deeper, it is decided to use a laser light source with longer wavelength and deeper penetration for treatment. If the laser cannot penetrate or penetrate shallowly and cannot reach the hair growth area, it will be difficult to see the effect. Generally, the penetration depth of the laser increases with the increase of the wavelength. Studies have shown that the ideal wavelength for damaging hair follicles is about 700nm. Another way to increase the penetration depth of the laser is to increase the light spot, which can reduce the loss of the laser in the tissue and make the laser penetrate deeper in the skin. In addition, the size of the spot also affects the speed of treatment.
2. Determination of Salon laser hair removal machine parameters: Laser hair removal is affected by various parameters such as its wavelength, spot, pulse width and energy, but the ideal value of each parameter is not yet known. According to the principle of selective photothermal action, while ensuring the selective absorption of melanin by light waves, its wavelength should be as long as possible. Theoretically, by lengthening the laser pulse width to make it close to the thermal relaxation time of the hair follicle, the therapeutic effect can be improved. Because the longer the pulse width, the less likely it is that the tiny structures in the epidermis, such as melanosomes, will be damaged, and the relatively large structures, such as the melanosomes in the hair follicle, will be more susceptible to damage. It is generally believed that the ideal hair removal laser pulse width should be between the thermal relaxation time of the epidermis (3-10ms) and the thermal relaxation time of the hair follicle (40-100ms).
The technical operation of the Salon laser hair removal machine seems very simple, but the experience of the operator affects the treatment effect. Although the operation of each laser hair removal machine will be different, it should generally include the following steps:
1. Investigate the medical history, check the recipient, analyze the skin type, and check the hair condition.
2. Turn on the power to warm up the machine.
3. Preparation of the treatment area: hair should be shaved before treatment, because the visible hair will damage the epidermis due to high heat caused by laser burning, and can also cause irreversible damage to the laser guide head and cause unpleasant odors, but machinery cannot be used. Epilation or wax depilation. In addition, the local area should be cleaned to remove grease and dirt.
4. Set the treatment parameters and conduct trial treatments.
5. Get the best parameters and complete the entire treatment.
6. Check the response after treatment, and explain relevant precautions
Precautions for use of Salon laser hair removal machine
1. During the treatment, both the physician and the recipient should wear laser protective glasses to prevent the eyes from being damaged by the laser.
2. The light spots should not overlap too much. Repeated irradiation will aggravate skin damage, and if the distance is too wide, the treatment effect will be affected.
3. When semiconductor laser hair removal, such as using cooling hand tools or hair removal under strong pulsed light, apply a certain pressure to the hand tools during the treatment, which can keep the hand tools in good contact with the skin, and can also drive away local blood and reduce Oxyhemoglobin absorbs laser energy.