Several wavelengths of laser energy have been used for hair removal, from visible light to near-infrared radiation. These lasers are usually defined by the lasing medium used to create the wavelength (measured in nanometers (nm)):
* Argon: 488 or 514.5 nm (no longer used for hair removal)
* Ruby: 694 nm (no longer used for hair removal; not safe on most skin types as it frequently produces side effects such as pigmentary changes (lightening or darkening of the skin) or worse for patients of all but white skin.[citation needed]
* Alexandrite: 755 nm (most effective, but safest on light skin)
* Pulsed diode array: 810 nm (for light to medium type skin)
* Nd:YAG: 1064 nm (for darker skin; Yag is capable of treating all six skin colors. However, there is not sufficient evidence that this laser can produce effective long-term hair removal)
Pulsewidth is an important consideration. It has been observed in some published studies that longer pulse widths may be safer for darker skin. However, shorter wavelengths may be more effective in removing hair.
Spot size, or the width of the laser beam, affects treatment. Theoretically, the width of the ideal beam is about four times as wide as the target is deep. Hair removal lasers have a round spot about the size of your finger (8-18 mm). Larger spot sizes help make treatments faster and more effective.
Fluence or energy level is another important consideration. Fluence is measured in joules per square centimeter (J/cm²). It's important to get treated at high enough settings to cause permanent damage to the hair follicles.
Repetition rate is believed to have a cumulative effect, based on the concept of thermal relaxation time. Shooting two or three pulses at the same target with a specific delay between pulses can cause a slight improvement in the heating of an area. This may increase the "kill rate" for each treatment slightly.
Epidermal cooling has been determined to allow higher fluences and reduce pain and side effects, especially in darker skin. Four types of cooling have been developed:
* Clear gel: usually chilled
* Contact cooling: through a window cooled by circulating water or internal cryogen.
* Cryogen spray: immediately before/after the laser pulse
* Air cooling: forced cold air at -34 degrees C (Zimmer Cryo 5 unit)
Multiple treatments, usually 6-8, but as much as 12 depnding on the type of hair you have and skin color have been shown in numerous studies to provide long-term reduction of hair. Current parameters suggest a series of treatments spaced at 4-6 weeks apart for most areas, although the timing of treatments has still not been standardized.
Sunday, September 21, 2008
Saturday, September 20, 2008
Electrolysis
Electrology is the practice of electrical depilation to permanently remove human hair. The actual process of removing the hair is referred to as electrolysis. The practitioner slides a hair-thin metal probe into each hair follicle. Proper insertion does not puncture the skin. Electricity is delivered to the follicle through the probe, which causes localized damage to the areas that generate hairs, either through the formation of caustic lye (galvanic method), overheating (thermolysis method), or both (blend method).
Three methods or "modalities" are used in electrology. Galvanic, Thermolysis, and Blend all have their own merits, and one method is not better than another. The success depends on the skill of the electrologist, the type of hair being removed, the condition of the skin and the pain threshold of the client. All three methods, when properly performed, can be thorough at destroying the hair matrix cells, and leaving follicles incapable of regrowing hair.
Galvanic
This modality is named after Luigi Galvani and uses a person's body as an electrolytic cell. Galvanic electrolysis was first reported in the medical literature by ophthalmologist Charles Michel in 1875 to remove ingrown eyelashes in patients with trichiasis. [1] A galvanic epilator is essentially a positive ground power supply that delivers 0-3 milliamperes through the body. The follicular probe is the cathode of an electrolytic cell. Sodium hydroxide formed at the cathode by the process of chemical electrolysis kills the hair matrix cells. Modern galvanic epilators automatically adjust the voltage to maintain constant current.
Thermolysis
Another method is known as thermolysis, RF, shortwave or diathermy. Thermolysis was developed in the 1920s and first reported in medical literature by Henri Bordier. [2] A thermolytic epilator is essentially a radio transmitter, usually with an output of about 0-8 watts at a frequency of 13.56 MHz. RF energy emanates from the probe tip to tissue within about a millimeter. Thermolysis works by heating the hair matrix cells to about 48°C (118.4° Degree Fahrenheit), causing electrocoagulation.
Blend
Galvanic and thermolysis are often combined in a method known as blend, developed by Arthur Hinkel in 1948, which uses both RF and direct current, combining many of the advantages of galvanic and thermolysis. [3] All three of these methods use a metal probe 50 to 150 µm (0.002 to 0.006 inches) in diameter which is inserted into the hair follicle to the depth of the dermal papilla or hair matrix, which is the site of formation of hair from highly mitotic and keratinized cells.
Three methods or "modalities" are used in electrology. Galvanic, Thermolysis, and Blend all have their own merits, and one method is not better than another. The success depends on the skill of the electrologist, the type of hair being removed, the condition of the skin and the pain threshold of the client. All three methods, when properly performed, can be thorough at destroying the hair matrix cells, and leaving follicles incapable of regrowing hair.
Galvanic
This modality is named after Luigi Galvani and uses a person's body as an electrolytic cell. Galvanic electrolysis was first reported in the medical literature by ophthalmologist Charles Michel in 1875 to remove ingrown eyelashes in patients with trichiasis. [1] A galvanic epilator is essentially a positive ground power supply that delivers 0-3 milliamperes through the body. The follicular probe is the cathode of an electrolytic cell. Sodium hydroxide formed at the cathode by the process of chemical electrolysis kills the hair matrix cells. Modern galvanic epilators automatically adjust the voltage to maintain constant current.
Thermolysis
Another method is known as thermolysis, RF, shortwave or diathermy. Thermolysis was developed in the 1920s and first reported in medical literature by Henri Bordier. [2] A thermolytic epilator is essentially a radio transmitter, usually with an output of about 0-8 watts at a frequency of 13.56 MHz. RF energy emanates from the probe tip to tissue within about a millimeter. Thermolysis works by heating the hair matrix cells to about 48°C (118.4° Degree Fahrenheit), causing electrocoagulation.
Blend
Galvanic and thermolysis are often combined in a method known as blend, developed by Arthur Hinkel in 1948, which uses both RF and direct current, combining many of the advantages of galvanic and thermolysis. [3] All three of these methods use a metal probe 50 to 150 µm (0.002 to 0.006 inches) in diameter which is inserted into the hair follicle to the depth of the dermal papilla or hair matrix, which is the site of formation of hair from highly mitotic and keratinized cells.
Sugaring
Sugaring is a method of hair removal that has been in use for thousands of years This ancient art goes back to 1900 BC when a hairless and smooth body was considered the standard of youth, beauty and innocence for women in Egypt. Today, this art has been revived because of new styles, sports and trends where smooth hairless skin is desired.[citation needed]
Two main methods exist. The Strip Method, uses a paper or fabric strip to remove the sugar (and hairs). This is very similar to waxing. The Hand Method, does not use any paper or fabric strips to remove the sugar, rather a flicking action is used by the therapist to remove the sugar and hairs.
Sugaring can be less painful because it only sticks to the hair (wax will also attach to the skin.) Nevertheless, as with other hair removal methods, there is some risk of skin irritation, sensitivity, or reaction. Though the process can leave a sticky mess, sugar is soluble in water and therefore sugaring involves a relatively easy cleanup with warm water.
Two main methods exist. The Strip Method, uses a paper or fabric strip to remove the sugar (and hairs). This is very similar to waxing. The Hand Method, does not use any paper or fabric strips to remove the sugar, rather a flicking action is used by the therapist to remove the sugar and hairs.
Sugaring can be less painful because it only sticks to the hair (wax will also attach to the skin.) Nevertheless, as with other hair removal methods, there is some risk of skin irritation, sensitivity, or reaction. Though the process can leave a sticky mess, sugar is soluble in water and therefore sugaring involves a relatively easy cleanup with warm water.
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