Method and apparatus for dermatological treatment and fractional skin resurfacing

Abstract

A system and method for performing fractional resurfacing of a target area of skin using electromagnetic radiation are provided. An electromagnetic radiation is generated by an electromagnetic radiation source. The electromagnetic radiation is caused to be applied to a particular portion of a target area of skin. The electromagnetic radiation can be impeded from affecting another portion of the target area of the skin by a mask. Alternatively, the electromagnetic radiation may be applied to portions of the target area of the skin, other than the particular portion.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] The present application claims priority from U.S. Provisional Patent Application Ser. No. 60 / 458,770 filed Mar. 27, 2003, the entire disclosure of which is incorporated herein by reference.BACKGROUND OF THE INVENTION [0002] 1. Field Of The Invention [0003] The present invention relates to methods and apparatus that use electromagnetic radiation for dermatological treatment and, more particularly to a method and apparatus that use optical radiation to ablate or damage a target area of skin surface for dermatological treatment, which skin surface includes the epidermis and parts of the dermis as the objective or side effect of the desired treatment. [0004] 2. Background Art [0005] There is an increasing demand for repair of or improvement to skin defects, which can be induced by aging, sun exposure, dermatological diseases, traumatic effects, and the like. Many treatments which use electromagnetic radiation have been used to improve skin ...

AI Technical Summary

Benefits of technology

[0017] It is therefore one of the objects of the present invention to provide an apparatus and method that combines safe and effective treatment for an improvement of dermatological disorders with minimum side effects. Another object of the present invention is to provide an apparatus and method that cause thermal skin damage to only a fraction of a target area of skin.

Problems solved by technology

Many treatments which use electromagnetic radiation have been used to improve skin defects by inducing a thermal injury to the skin, which results in a complex wound healing response of the skin.

However, patients may experience major drawbacks after each LSR treatment, including edema, oozing, and burning discomfort during first fourteen (14) days after treatment.

These major drawbacks can be unacceptable for many patients.

A further problem with LSR procedures is that the procedures are relatively painful and therefore generally require an application of a significant amount of analgesia.

Any LSR treatment results in thermal skin damage to the treatment area of the skin surface, including the epidermis and / or the dermis.

LSR treatment with pulsed CO2 lasers is particularly aggressive, causing thermal skin damage to the epidermis and at least to the superficial dermis.

Following LSR treatment using CO2 lasers, a high incidence of complications can occur, including persistent erythema, hyperpigmentation, hypopigmentation, scarring, and infection (e.g., infection with Herpes simplex virus).

Using the Er:YAG laser results in a thinner zone of thermal injury within the residual tissue of the target area of the skin.

However, LSR that uses the Er:YAG laser produces side effects similar to those made by LSR that uses the CO2 laser within the first days after treatment.

A limitation of LSR using CO2 or Er:YAG lasers is that ablative laser resurfacing generally can not be performed on the patients with dark complexions.

The removal of pigmented epidermis tissue can cause severe cosmetic disfigurement to patients with a dark complexion, which may last from several weeks up to years, which is considered by most patients and physicians to be unacceptable.

Another limitation of LSR is that ablative resurfacing in areas other than the face generally have a greater risk of scarring.

LSR procedures in areas other than the face result in an increased incidence of an unacceptable scar formation because the recovery from skin injury within these areas is not very effective.

This type of wound healing can result in a decrease of photoaging related structural damage.

Avoiding epidermal damage in NCR techniques decreases the severity and duration of treatment related side effects.

While it has been demonstrated that these techniques can assist in avoiding epidermal damage, one of the major drawbacks of these techniques is their limited efficacies.

Even after multiple treatments, the clinical improvement is often far below the patient's expectations.

In addition, clinical improvement is usually several months delayed after a series of treatment procedures.

Another limitation of NCR procedures relates to the breadth of acceptable treatment parameters for safe and effective treatment of dermatological disorders.

The NCR procedures generally rely on an optimum coordination of laser energy and cooling parameters, which can result in an unwanted temperature profile within the skin leading to either no therapeutic effect or scar formation due to the overheating of a relatively large volume of the tissue.

Yet another problem of non-ablative procedures relates to the sparing of the epidermis.

A further problem of both ablative and nonablative resurfacing is that the role of keratinocytes in the wound healing response is not capitalized upon.

Another major problem with all LSR and NCR techniques now used is the appearance of visible spots and / or edges after treatment due to inflammation, pigmentation, or texture changes, corresponding to the sites of treatment.

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