2021/12/24

Theory of medical hair removal

Reading Time: <1 minuteRecently, I have been receiving more and more requests to supervise hair removal sites and check the medical suitability of articles.There seem to be very few medical institutions where doctors fully understand the theory of hair removal and perform hair removal themselves.It seems that nurses are in charge of hair removal treatments in almost all medical institutions, but it is questionable whether the nurses read and understand hair removal theory and apply it clinically.When removing hair, the target is the melanin pigment in the hair.Oxygenated hemoglobin is the color of blood, the color of red blood cells in the capillaries within the dermis.The shorter the wavelength of the laser light, the easier it is to absorb the melanin and raise the temperature of the melanin, the better, but in reality, for example, if the wavelength is 400 nm, it will just be absorbed by the melanin in the epidermis and the light will not reach the dermal papilla and bulge area. It just causes epidermal burns.Also, if you are trying to destroy melanin without burning the blood vessels, you might think that a wavelength of 694nm (ruby laser) would be better, but in reality, the shorter the wavelength, the more the light is scattered, and with ruby's 15nm, only a small amount of light reaches the dermis. 750%.For this reason, the wavelength suitable for medical hair removal lasers to destroy melanin in hair and hair roots is approximately 790 to 755nm, so 515nm alexandrite light is suitable for medical hair removal lasers.In beauty salons, hair removal is performed using IPL light that contains various wavelengths starting from 1200 nm.This is because only doctors are allowed to handle lasers under the Medical Practitioners Act.For hair removal, IPL is used in beauty salons, so the wavelength is limited (IPL with a wavelength of 1-2 nm was used for medical hair removal) *Factors that affect the hair removal effect 10: Wavelength 30: Pulse width XNUMX: Fluence XNUMX: Number of irradiations XNUMX: Number of hair removal *Client side situation XNUMX: Thickness of hair to be removed XNUMX: Color of hair to be removed XNUMX: Density of hair XNUMX: Area of ​​hair removal XNUMX: Skin color Take these into consideration when hair removal is performed. We will implement it.Theoretically, the spectrum of IPL has been almost completed, and the only way to develop a hair removal device is to increase the fluence by combining it with high frequency or increasing the cooling power, unless there is a problem in terms of medical law and pharmaceutical equipment law.It is important that heat is firmly transmitted to the bulge area and dermal papilla to cause tissue destruction, and IPL, unlike laser, has the disadvantage that there is a lot of diffusion and it is difficult to transmit energy only to shallow areas.If the fluence is increased unnecessarily, epidermal burns are likely to occur, so care must be taken when removing hair for tanned clients or clients with dark skin. Unlike a laser, IPL is a pulsed light that is incoherent, has multiple wavelengths, and has scattering characteristics. Generally, it uses a xenon lamp as a light source and uses a wavelength of XNUMX to XNUMX nm, with the short wavelength region cut off with a filter. Masu.Depending on the application, one or two additional filters are added to limit the wavelength band used for actual treatment.The energy intensity is not uniform and has a peak on the short wavelength side of the oscillation wavelength band. IPL treatment irradiates the skin surface with pulsed light that oscillates in milliseconds through a sapphire irradiation filter.The spot size is often large rectangular, about XNUMX x XNUMX mm, making it possible to treat a wide area in a short time. IPL has different oscillation wavelength bands, settable pulse widths (ex. several milliseconds to tens of milliseconds), pulse division method (ex. single, double, triple), uniformity of output within pulses, and skin irradiation surface for each device. There are large differences in settings and performance, including the presence or absence of a cooling device and its method.            

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