Abstract: Methods of applying laser light to the skin, and apparatus therefor, include methods for removing hair, for bleaching hair, for transdermal drug delivery, for sensing a body function, for skin tightening, and for imaging subsurface structures are described. The hair removal methods and the hair bleaching methods include infiltrating a transparent fluid with an index of refraction greater than that of skin tissue into hair ducts to help transmit the laser light down the hair ducts. The transdermal drug delivery and body function sensing methods include exfoliating layers of the stratum corneum from a section of skin with laser light. A transdermal drug delivery patch can be placed over the exfoliated skin section, or an electrical sensor can be placed over the exfoliated skin section.

Abstract: A device for inhibiting growth of unwanted hair. A light-absorbing contaminant applied to the surface of a section of skin so that some of the contaminant infiltrates hair ducts is placed in spaced apart relationship to an illumination source that provides light absorbed by the contaminant. When the light penetrates the section of skin and is absorbed by the contaminant in the hair ducts, the follicles and/or skin tissue surrounding the follicles is heated so as to inhibit hair growth.

Abstract: A device and process for the permanent removal of unwanted human hair. Hair on a section of skin is contaminated with a substance having high absorption of a frequency band of light. The skin is illuminated with light at this frequency band at sufficient intensity and duration to kill the follicles or the skin tissue feeding the hair. One embodiment to produce death of the follicles or the skin tissues feeding the hair is by photochemical reaction.

Abstract: Methods of applying laser light to the skin, and apparatus therefor, include methods for removing hair, for synchronizing hair growth, for stimulating hair growth, for treating Herpes virus, for reducing sweat and body odor, for in situ formation of a chromophore in hair ducts, for reducing light loss at the skin surface, for grafting of hair stem cells, and for removing keloid or hypertrophic scars. The hair removal methods include controlling the proportions of photomechanical and photothermal damage by selection of laser parameters, chromophore particle size and/or pulse duration, with optional dynamic skin cooling. Additional hair removal methods include infiltrating a photoactivated drug into hair ducts and exposing the skin to sunlight or administering an anti-proliferative agent into hair ducts, for example, by encapsulating the anti-proliferative agent in a slow release vehicle.

Abstract: The present invention provides a very simple easily administered skin treatment process for (1) the removal of superficial epidermal skin cells in the human skin (2) the reduction or removal of unwanted hair and (3) the mitigation of skin conditions such as acne and seborrhea. A contaminant having a high absorption at at least one wavelength of light is topically applied to a section of the surface of the skin. A preferred contaminant is a mixture of 20% by weight of one micron graphite particles in mineral oil. Graphite is a very strong absorber of 1.06 micron light produced by the Nd:YAG laser. Portions of the contaminant are forced to infiltrate into spaces between the superficial epidermal cells, into hair ducts in the skin and into and/or adjacent to sebaceous glands. The skin section is illuminated with short laser pulses at the matching wavelength, so as to impact sufficient energy to the contaminant to cause explosion in the contaminant.

Abstract: A process for the permanent destruction of unwanted human hair. Hair duct in a section of skin in which the unwanted hair is growing is contaminated with a contaminant having a very large number of small particles having a high absorption at at least one frequency band of light. The skin section is then illuminated with a series of short pulses of light at the frequency band of high absorption, the first of the short pulses having sufficient energy to cause a large number of the particles to explode into two or more fragments so as to spread said contaminant in the hair ducts and subsequent pulses having sufficient energy to cause a large number of the fragments to further explode into additional fragments to further spread the contaminant in the hair duct. The explosions and energy is transferred to and from the particles and fragments causing damage to skin tissue surrounding said hair ducts so as to cause death to the hairs growing in the ducts.

Abstract: A device and process for the permanent removal of unwanted human hair. Hair on a section of skin is contaminated with a substance having high absorption of a frequency band of light. The skin is illuminated with light at this frequency band at sufficient intensity and duration to kill the follicles or the skin tissue feeding the hair. Specific embodiments to produce death of the follicles or the skin tissues feeding the hair by heating and by photochemical reaction.

Abstract: The present invention provides a very simple easily administered skin treatment process for (1) the removal of superficial epidermal skin cells in the human skin (2) the reduction or removal of unwanted hair and (3) the mitigation of skin conditions such as acne and seborrhea. A contaminant having a high absorption at at least one wavelength of light is topically applied to a section of the surface of the skin. A preferred contaminant is a mixture of 20% by weight of one micron graphite particles in mineral oil. Graphite is a very strong absorber of 1.06 micron light produced by the Nd:YAG laser. Portions of the contaminant are forced to infiltrate into spaces between the superficial epidermal cells, into hair ducts in the skin and into and/or adjacent to sebaceous glands. The skin section is illuminated with short laser pulses at the matching wavelength, so as to impact sufficient energy to the contaminant to cause explosion in the contaminant.

Abstract: A process for the long term or permanent prevention of growth of unwanted hair. The upper portions of hair ducts (i.e. portions near the skin surface) in a section of skin are infiltrated with a contaminant having a high absorption at at least one frequency band of light. The skin is then illuminated using a process having at least two distinct phases. In a "mechanical" phase the skin section is illuminated (e.g., by a laser) with at least one short pulse of light sufficient to cause tiny explosions in the contaminant forcing portions of the contaminant more deeply into the hair ducts. During a "thermal" phase the skin section is then illuminated so as to heat the contaminant substantially without further explosion or vaporization of the contaminant. The hot contaminant heats portions of the skin tissue immediately surrounding the contaminant to a temperature high enough and for a long enough period of time to devitalize the tissue.

Abstract: The present invention provides a process for the destruction of unwanted human hair. Hair ducts in a section of skin in which the unwanted hair are growing is contaminated with a contaminant having a high absorption at at least one frequency band of light. The skin section is then illuminated with light at the frequency band of high absorption so as to impact sufficient energy to the contaminant so as to cause death to the hairs growing in the ducts. In a preferred embodiment the contaminant is a mixture of 1 micron graphite particles in mineral oil and each section is illuminated with about 5 laser pulses at 1.06 micron wavelength produced by a Nd:YAG laser, each pulse having an energy density of about 3 Joules/cm.sup.2 and a pulse width of about 10 nanoseconds. In another preferred embodiment the hairs in the section of skin being treated are pulled out prior to application of the contaminant so as to provide more space for the contaminant in the hair duct.

Abstract: The present invention provides a process for laser assisted drug delivery through the skin. A drug and a explosive absorber of light energy are applied topically to the skin. The treated area of the skin is illuminated with very short pulses of light which is preferentially absorbed by the absorber causing a very large number of tiny explosions. The tiny explosion forces portions of the drug to penetrate into the skin. A preferred embodiment utilizes small graphite particles and an Nd:YAG short pulse laser.