Apparatus and method for dynamic cooling of biological tissues for thermal mediated surgery

US6171301A · kind A · utility

Assignee

• The Regents of the University of California · US

Inventors

• J. Stuart Nelson · Laguna Niguel, US
• Thomas E. Milner · Austin, US
• Lars O. Svaasand · Trondheim, NO

Key dates

• Filing date: Nov 3, 1997
• Grant date: Jan 9, 2001
• Expiry date: Nov 3, 2017

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61N2005/0644
• WIPO field: Medical technology
• WIPO sector: Instruments

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.