JP2002528191A - Hair removal method by percutaneous use of laser light - Google Patents

Abstract

(57) [Summary] An epilation method used mainly for cosmetic purposes involves the percutaneous use of laser light having a wavelength that targets the keratin component of hair, thereby removing the surrounding skin or tissue. Hair follicles are peripherally damaged by photopyrolysis without damage, and this first method utilizes a second wavelength of light generated by the same source used to generate the first wavelength of light. It may be supplemented by the use of an internal hair removal method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[Background of the Invention] FIELD OF THE INVENTION The present invention relates generally to a method of permanently removing hair using laser light. More specifically, the present invention relates to the transdermal use of laser light to target the keratin component of hair, thereby peripheralizing hair by photothermal degradation without damaging the surrounding skin or tissue Related to. 2. Description of the Prior Art Currently available laser hair removal methods are inherently intrafollicular (intrafollicula).
It may be classified as either r) or transcutaneous. The intrafollicular method transmits laser light to the pores through a small probe tip. The wavelengths of light utilized are those wavelengths that are readily absorbed by either hair melanin or hemoglobin in the blood vessels surrounding papillary projections. The absorption of this light energy is
Heat is generated, resulting in damage to the hair shaft and photocoagulation of the tissue surrounding the papillae, which later makes the hair peripheral. Since the light energy used in this method is absorbed by either blood or melanin in the skin, it requires the use of a very narrow beam to target each hair and prevent damage to surrounding tissue. I do. This is a meticulous and time-consuming process that must be administered by a skilled technician. When targeting melanin, this method loses its effectiveness when used on patients with light hair or dark skin. In addition, some methods in this category require that a needle-like probe tip be inserted into the pore, a painful procedure that must be repeated for each hair. is there.

[0002] Currently available transcutaneous laser hair removal methods utilize a substance that is massaged into the skin to penetrate the capillaries. After washing the substance from the surface of the skin, light of a wavelength that passes through the skin but is absorbed by the substance is directed to the treated area. The absorption of energy by the substance applied to the capillaries photocoagulates the tissue surrounding the papillae and makes the hair peripheral. This method allows treatment of a considerable area of the skin, but requires an inconvenient and time-consuming application of the light absorbing material.
In addition, care must be taken to completely remove material from the skin surface prior to laser treatment to avoid damage to the skin.

There is a need for new methods that provide faster, more convenient, less painless permanent hair removal without damaging the patient's skin due to the disadvantages associated with each of the hair removal methods used today.

SUMMARY OF THE INVENTION The present invention relates to a permanent hair removal method used primarily for cosmetic purposes. This method involves the transcutaneous use of laser light having a wavelength of 880-930 nanometers, where the light is directed to the area of the skin where hair loss is desired. Light of this wavelength is transmitted through the skin with minimal absorption by blood, blood components, and melanin. However, this wavelength is easily absorbed by the protein keratin, a major component of all-color hair. The absorption of light energy by keratin generates heat, which damages the hair shaft and hair root, photocoagulates the blood vessels and tissues surrounding the papillae, and consequently makes the hair peripheral and regrows. Prevent.

In a preferred embodiment, the method comprises a second harmonic generation or a 3-mixing plus second harmonic generation from the same laser source that primarily produces the first 880-930 nanometer wavelength. (3-mixing plus second harmonic generati
on) also includes the use of a second wavelength of laser light generated by known means. This second wavelength of light, which is in the range of 440-465 nanometers, is easily absorbed by blood components and melanin, respectively. Transmitting a second wavelength of light to the pores in a manner described in the prior art to treat a small percentage of hairs having papillae on the thickness of the epidermis beyond the effective range of the first wavelength of light. Hair follicle probes are used for this. In this way, a single laser light source can be used to treat all types of hair in the most painless, most efficient, cost effective and as convenient way as possible.

There are several problems associated with hair removal methods in the prior art. Some of these methods are painful for the patient. Other methods have efficacy that varies depending on the color of the patient's skin and hair. Many methods must be performed by skilled technicians to reduce the risk to the patient. All of these methods involve expensive, elaborate and time-consuming processing. Furthermore, all methods have a considerable risk of damaging the skin if not performed correctly.

The present invention is 1) fast and convenient, 2) less painful, 3) effective for all types of hair, 4) reduced risk of damage to the skin, and 5) low cost ,
An object of the present invention is to provide a hair removal method using a low maintenance and low power consumption laser light source. Further objects and advantages of the invention will become apparent in view of the drawings and description.

[Description of Preferred Embodiment] Description FIG. 1 is a diagram showing a preferred embodiment of the present invention. As shown, a laser beam 18 is emitted from a probe tip 19 of a fiber optic cable (not shown). The other end of the fiber optic cable is connected to a laser light source (not shown). The size and shape of the light beam may be varied to meet the requirements of all individual applications. FIG. 1 shows the structure of the hair 9 and the surrounding upper and lower skin layers known as epidermis 16 and dermis 17, respectively. Hair 9 has a hair shaft 10 and a hair root 11 shown shaved near the surface of the skin. Hair follicle 13 is a follicle that surrounds hair shaft 10, hair root 11, and adjacent sebaceous gland 15. At the lower end of the hair follicle 13 there is a papillary projection 12, and the papillary projection is further reduced by a blood vessel 14 to the hair root 1.
Nourish one. In order to prevent regrowth of the hair 9, the papillae 12 and the blood vessels 14 must be sufficiently damaged to prevent continuous nourishment of the hair root 11.

FIG. 2 shows the relatively high absorption of light in the 880-930 nanometer wavelength range by the protein keratin. FIG. 2 also shows the relatively low absorption of light in the same range by hemoglobin and melanin present in the tissue surrounding the hair. These absorptive characteristics of keratin, hemoglobin and melanin are attributed to the transdermal use of light of a selected wavelength to target keratin in the hair shaft, and then to the papillae without damaging surrounding tissues. It allows the projections to be peripheral.

The preferred embodiment of the present invention primarily utilizes laser light 18 in the range of 880-930 nanometers. As shown in FIG. 2, light of this wavelength passes through the dermis 17 and epidermis 16 with minimal absorption by blood, blood components, and melanin. However, this wavelength is easily absorbed by the protein keratin, a major component of all color hair. The absorption of light energy by keratin is due to hair shaft 10 and hair root 1
1. Generates heat that damages 1. This heat can photocoagulate the blood vessels 14 that nourish the papillae 12, resulting in the hair 9 becoming peripheral and increasing the likelihood of permanent hair loss.

[0011] The power level and duration of the laser pulse directed onto the skin must be carefully selected to optimize the heat transfer from the hair shaft and root to the papillae. By way of example, a 0.1 second pulse from a laser transmitting a power level of about 6 milliwatts per hair to the hair root will transfer enough energy to the hair shaft and hair root to severely damage the papillae and cause permanent hair loss Result in a high likelihood.
The use of shorter, higher energy laser pulses allows the hair to evaporate quickly,
The result is subsurface epilation with a reduced possibility of permanent hair periphery. Pulses of less than 0.0001 seconds in duration with sufficient energy to damage the hair are very explosive, i.e. photoacoustic, absorptive, and hypo- or hyper-pigmentation ). Conversely, pulses longer than 0.2 seconds can scar scars surrounding tissue.

[0012] While very effective for hair with papillae at epidermal thicknesses less than 1.0 centimeter, laser scattering and absorption can reduce the small percentage of hair that exceeds this limit. It does not make the transdermal method so effective. For efficient hair removal of these hairs, a preferred embodiment of the present invention has an intrafollicular application of laser light 18 having a second wavelength as shown in FIG. This second wavelength is the first 880
It is generated from the same laser source producing the -930 nanometer wavelength by known means such as second harmonic generation or 3-mixing plus second harmonic generation. In the method described in the prior art, the hair follicle probe 20 has a second wavelength in the hair 9 with papillae 12 at the epidermis thickness beyond the coverage of the hair follicle 13 and the percutaneous method. Is used to directly transmit the laser light 18. This second wavelength of light, which is in the 440-465 nanometer range, is easily absorbed by either melanin in the hair 9 or hemoglobin in the blood vessels 14 surrounding the papillae 12, resulting in hair shaft 10 The wound, the tissue surrounding the papillae is photocoagulated, and the hair is later made peripheral. In this way, a laser light source is used to treat all types of hair in a single, inexpensive, less painful, most efficient, cost effective and as convenient as possible Can be done.

The above description includes specificities belonging to laser light wavelength, pulse duration, and power level, but these specificities are illustrative of one preferred embodiment of the present invention rather than limiting the scope of the present invention. Should be interpreted as Changes in the first and second laser wavelength, pulse duration, and power level are possible without significantly reducing the effectiveness of the method. The present invention contemplates all changes in these and all other laser parameters that achieve equivalent results.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a region of the skin showing the structure of the hair and skin and the transcutaneous application of laser light.

FIG. 2 is a graph showing absorption spectra of hemoglobin, melanin, and keratin in the visible and near-infrared ranges.

FIG. 3 is a cross-sectional view of a region of the skin showing the structure of the hair and skin and the intrafollicular application of laser light.

[Explanation of symbols]

 Reference Signs List 9 hair 10 hair shaft 11 hair root 12 papillary projection 13 hair follicle 14 blood vessel 15 sebaceous gland 16 epidermis 17 dermis 18 laser beam 19 probe tip of fiber optic cable 20 probe of hair follicle

[Procedural Amendment] Submission of translation of Article 34 Amendment of the Patent Cooperation Treaty

[Submission date] September 27, 2000 (2000.9.27)

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[Description of Preferred Embodiment] Description FIG. 1 is a diagram showing a preferred embodiment of the present invention. As shown, the laser beam 18 is emitted from the probe tip 19 of the full § Iba optic cable 21. The other end of the fiber optic cable is connected to the LES Za source 22. The size and shape of the light beam may be varied to meet the requirements of all individual applications. FIG. 1 shows the structure of the hair 9 and the surrounding upper and lower skin layers known as epidermis 16 and dermis 17, respectively. Hair 9 has a hair shaft 10 and a hair root 11 shown shaved near the surface of the skin. Hair follicle 13 is a follicle that surrounds hair shaft 10, hair root 11, and adjacent sebaceous gland 15. At the lower end of the hair follicle 13 there is a papillae 12 which feeds the hair root 11 further by the blood vessels 14. In order to prevent regrowth of the hair 9, the papillae 12 and the blood vessels 14 must be sufficiently damaged to prevent continuous nourishment of the hair root 11.

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FIG.

──────────────────────────────────────────────────続 き Continuation of front page (81) Designated country EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE ), OA (BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE, LS, MW, SD, SZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, CA, CH, CN, CU, CZ, DE, DK, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IS, JP, KE, KG , KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, UA, UG, UZ, VN, YU, ZWF terms (reference) 4C026 AA03 FF02 FF22 HH02 HH12 4C082 RA01 RE02 RE22 RL02 RL12

Claims (5)

[Claims] A method for permanently removing hair from the skin using a laser beam having a wavelength that is substantially absorbed by the keratin component of the hair through the skin with minimal absorption, wherein the laser beam photocoagulates the hair. A method of directing on the surface of the skin for a time sufficient to cause 2. The method of claim 1, wherein said wavelength of said laser light is 880-930 nanometers. 3. The second wavelength of the laser light is from the same laser light source that mainly produces the 880-930 nanometer wavelength, from a second harmonic generation or a 3-mixing plus type second light source. 3. The method of claim 2 wherein said second light source is generated by known means such as harmonic generation, and b) said second light source is directed to said hair by intrafollicular means. 4. The method of claim 3, wherein said second wavelength is 440-465 nanometers. 5. The method of claim 1, wherein said duration of said pulse of said laser light is selected to optimize heat conducted to said papillae of said hair.