Abstract: An improvement in a method for providing localized cooling of tissue when thermally mediated by electromagnetic radiation including directing at least one spurt of a heat transferring substance onto a selected location on the tissue, and preventing ignition of the heat transferring substance by heating from the electromagnetic radiation. Preferably liquid carbon dioxide under pressure is supplied as the heat transferring substance, and adiabatically expanded to provide a solid carbon dioxide spray onto the selected location.

Abstract: A method and apparatus for performing a laser treatment of a patient includes applying a positive pressure impulse on a predetermined target site on the patient with sufficient positive pressure arising from the momentum flux of sprayed material incident on the target site to momentarily lessen pain sensation during irradiation during or proximate in time to irradiation of the target site. The predetermined target site is cooled by applying a predetermined amount of coolant or cryogen onto the target site. The target site is radiated with energy to produce heat in tissue at the target site while leaving a superficial part of the target site substantially undamaged due to dynamic cooling of the superficial part of the target site by the coolant. Mediation of the pain sensation arising from the radiation is at least partially masked or lessened by the positive pressure impulse and/or by the temperature of the coolant.

Abstract: The invention is a technique for dynamic measurements of the heat transfer coefficient to the outer layer of the skin surface using a high thermal conductivity metal in an insulating block as the standardized target. The coefficient is dependent on the specific design of the cryogen valve and nozzle, and values up to 11 500 W/m2K values were measured for a 100 ms long spurts. The values for longer spurts are dependent on air humidity, as ice/snow formation then tends to form a thermally insulating layer. The average value of the heat transfer coefficient for a 200 ms long spurt was determined to 8000 W/m2K for conditions of normal room humidity and temperature. The technique enables an improved prediction of the temperature profile and cooling efficiency during therapy, and may thereby contribute to an improved therapeutic outcome.

Abstract: The invention is a technique for dynamic measurements of the heat transfer coefficient to the outer layer of the skin surface using a high thermal conductivity metal in an insulating block as the standardized target. The coefficient is dependent on the specific design of the cryogen valve and nozzle, and values up to 11 500 W/m2K values were measured for a 100 ms long spurts. The values for longer spurts are dependent on air humidity, as ice/snow formation then tends to form a thermally insulating layer. The average value of the heat transfer coefficient for a 200 ms long spurt was determined to 8000 W/m2K for conditions of normal room humidity and temperature. The technique enables an improved prediction of the temperature profile and cooling efficiency during therapy, and may thereby contribute to an improved therapeutic outcome.

Abstract: Dynamically cooling the epidermis of a port wine stain patient undergoing laser therapy permits maximization of the thermal damage to the port wine stain while at the same time minimizing nonspecific injury to the normal overlying epidermis. A cryogenic spurt is applied to the skin surface for a predetermined short period of time in the order of tens of milliseconds so that the cooling remains localized in epidermis while leaving the temperature of deeper port wine stain vessels substantially unchanged. The result is that epidermal denaturation and necrosis which normally occurs in uncooled laser irradiated skin sites does not occur and that clinically significant blanching of the port wine stains at the dynamically cooled sites establishes that selective laser photothermolysis of the port wine stain blood vessels is achieved. In addition, dynamic epidermal cooling reduces patient discomfort normally associated with flashlamp-pumped pulsed dye laser therapy.

Abstract: Dynamically cooling the epidermis of a port wine stain patient undergoing laser therapy permits maximization of the thermal damage to the port wine stain while at the same time minimizing nonspecific injury to the normal overlying epidermis. A cryogenic spurt is applied to the skin surface for a predetermined short period of time in the order of tens of milliseconds so that the cooling remains localized in epidermis while leaving the temperature of deeper port wine stain vessels substantially unchanged. The result is that epidermal denaturation and necrosis which normally occurs in uncooled laser irradiated skin sites does not occur and that clinically significant blanching of the port wine stains at the dynamically cooled sites establishes that selective laser photothermolysis of the port wine stain blood vessels is achieved. In addition, dynamic epidermal cooling reduces patient discomfort normally associated with flashlamp-pumped pulsed dye laser therapy.

Abstract: An improved device for delivery of photoenergy from a light source, such as a laser, into a uterine cavity for photodynamic therapy is comprised of a plurality of optic fibers, which are bundled together and inserted into the uterine cavity by means of a uterine cannula. The cannula is positioned within the uterine cavity at a preferred location and then withdrawn thereby allowing the plurality of optic fibers to splay or diverge one from the other within the cavity. Different portions of the distal tip of the optic fiber is provided with a light diffusing tip, the remainder being provided with a nondiffusing tip portion. The fiber optic shape, as well as the segment which is permitted to actively diffuse light through the tip, is selected in order to provide a more uniform exposure intensity of the photo energy or at least sufficient radiation directed to each segment of the uterine walls.