Optical system for treatment of vascular lesions

Abstract

An improved optical system for treatment of disorders of the skin, especially vascular lesions, such as Port Wine Stains. The system irradiates the skin with radiation at a predetermined wavelength and cools the skin during a predetermined time interval in coordination with delivery of the radiation. The absorption of the radiation by the skin and the change in temperature of the skin is monitored by the system and the operation of the radiation delivery system is controlled to optimize treatment of the vascular lesion. The source of irradiation is an arc lamp and the cooling system delivers a cooling gas to a lens in contact with the skin. The cooling gas can be carbon dioxide, freon, or any other appropriate gas. The lens used has a high heat conductivity and may be formed of sapphire.

Description

FIELD OF THE INVENTIONThe present invention relates to an optical system for treatment of disorders of the skin, especially vascular lesions, such as Port Wine Stains.BACKGROUNDPortWine Stains (PWS) are congenital disorders of the skin in which vascular malformations produce red-colored isolated lesions occurring most commonly on the face, trunk and neck. The lesion is basically an area of localized enlarged and ectatic blood vessels in the upper dermis. PWS tends to progress from a pale pink and flat lesions in childhood to nodular and dark red-purple lesions in adulthood. Its unpleasant cosmetic appearance causes psychological stress and makes the patient seek medical help. The goal of PWS treatment is to restore the normal color of the skin by selectively destroying the enlarged blood vessels while keeping the rest of the cutaneous structures intact.The prior art method of choice for treatment of PWS is photocoagulation of the enlarged blood vessels. Ideally, absorption of the la...

AI Technical Summary

Problems solved by technology

Its unpleasant cosmetic appearance causes psychological stress and makes the patient seek medical help.

Melanin, therefore, has been a potential barrier for the incident laser light causing hearing of the epidermis and reducing the amount of light which reaches the underlying blood vessels.

Higher energy doses per treatment may produce unwanted epidermal or dermal damage.

A pulsed dye laser system is expensive for an average Dermatologist with a limited purchasing power.

However, in the treatment of vascular lesions the coherence of the laser beam is not a critical consideration as long as a light source with proper powers at the right wavelengths can be focused onto the skin with spot sizes in the range of 3-5 mm in diameter (similar to the spot sizes reported in such applications).

Consequently, most Dermatologists can not justify the high cost of purchasing a laser based systems for this application.

Another cost consideration is the patients who may not be able to afford the high costs of such treatments.

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