Intense pulsed light therapy instrument, English name (intense pulsed light), IPL or pulsed intense light.
Working principle: Intensive pulsed light (IPL) is a non-laser light source. It uses a xenon lamp light source. It is an incoherent light composed of multiple pulse sequences. It has the characteristics of wide frequency range and high energy density. It is filtered by coating Light with a shorter wavelength has a spectrum in the wavelength range of 560nm to 1200nm. Using the principle of selective light and heat to achieve the auxiliary treatment effect of improving skin appearance and reducing hair.
Mechanism of action: Similar to the principle of laser action, the theoretical basis of intense pulsed light therapy is also the principle of selective photothermal action. The difference is that the intense pulsed light is a broad spectrum, which can cover multiple target chromophores, such as melanin, oxyhemoglobin, water and other absorption.
(1) Pigmented hyperplastic lesions
The melanin in the skin as the target tissue absorbs the entire visible light spectrum, and the absorption rate gradually decreases with the increase of the light wave wavelength. Generally speaking, below 800nm, melanin has strong absorption of the spectrum, while the absorption of melanin in the near infrared spectrum gradually decreases. According to the different pulse width, the absorbed light energy will have different changes in the characteristics of tissue effect. For ordinary pigment particles, the thermal relaxation time is usually tens to hundreds of nanoseconds. If the pulse width of the applied light wave is narrow, the tissue effect is mainly manifested as a photomechanical reaction, that is, the so-called "microburst" occurs, and selective light occurs. Cracking effect; if the pulse width is wider, but basically matches the thermal relaxation time, a "selective photothermal effect" occurs; if the pulse width is significantly longer than the thermal relaxation time of the pigment particles, a non-selective thermal effect will be generated. At the same time, the pigment and surrounding tissues will simultaneously produce thermal coagulation and necrosis. The energy control is appropriate. The three effects can produce the destruction, decomposition, and removal of the chromophore, but the damage to the surrounding tissue of the chromophore and the use conditions of the intense pulsed light are different. The current strong pulsed light equipment mostly belongs to the third case.When treating pigmented lesions, melanin can choose to absorb the strong pulsed light spectrum to produce selective light absorption, but the pulse width of the strong pulsed light is usually wider, according to the pigment The size of the particles and the relationship between the pulse width and the thermal relaxation time of the particles mostly produce non-selective thermal coagulation. The coagulated tissue is eliminated by phagocytes.
(2) Polychalacia and hirsutism
Hair has a growth cycle, which can be roughly divided into incubation period, growth phase, and recession phase. Growth phase hair has a complete structure such as hair follicle and hair growth. Yellow human hair follicles contain pigments, mostly black. In the incubation period and recession period, most of the hair does not have a hair follicle structure. To eliminate excess hair, is to use the characteristics of this hair anatomy, using a strong pulsed light with a fixed penetration depth and a wavelength that has good absorption capacity in melanin, so that the light bulbs and hair shafts irradiated by light absorb a lot of light Energy, heat is generated by energy conversion, and is transferred to the end of the hair ball through the protein in the hair, so that the entire hair is heated, and the protein and the cell have coagulative necrosis. Eventually, the necrosis of the growing cell causes the entire hair to fall off.