METHOD FOR COOLING LOCAL AREA OF BIOLOGICAL TISSUE Russian patent published in 1994 - IPC

FIELD: medicine. SUBSTANCE: method comprises the steps of delivering low-temperature gas flow through insulated pipe with a nozzle at its end onto local area of biological tissue, ensuring minimum possible temperature of gas flow at the point of its contact with tissue by selecting delivery conditions and nozzle-to-tissue distance. As temperature on the tissue surface drops to cryoscopic level, destruction of tissue is prevented by suspending the delivery of gas flow. Heat of ambient atmosphere raises the temperature of tissue surface while temperature field in the depth of tissue stays practically unchanged. Cooling is resumed and continued until temperature on the surface of tissue approaches cryoscopic level. Said process is repeated many times. Pulsating supply of gas flow rules out supercooling of tissue surface while providing required cooling in deep tissue structures. Gas flow described above may be quasistatic with low flow velocities thus ensuring low coefficients of heat transfer from the surface of tissue. EFFECT: deep cooling of local surface of tissue without its destructive injuries. 2 cl