GB1243248A - Cryosurgical appliance - Google Patents

Abstract

1,243,248. Cryosurgical appliances. LINDE A.G. 8 Nov., 1968 [10 Nov., 1967], No.53162/ 68. Heading A5R. A cryosurgical appliance for freezing and removing undesirable body tissue comprises a handle 12, Fig. 2, to which is fixed an intermediate member 13 carrying a liquid nitrogen container 14 of about 300 cn<SP>3</SP> capacity and a tubular probe 16 having a thermally insulated shank and a thermally conductive nose 30, Fig. 3, in which coolant passing from the container 14 through flow controlling means is evaporated to cool the nose by a controlled heater adjacent the nose, the gas so formed being fed back through the probe and handle into a discharge hose connected to a union 20 on the handle. The discharge hose is connected through an electromagnetic valve to a suction pump. The appliance also has a viewing and illuminating system comprising a fibre optical light guide 18, a member 18a which connects the guide 18 optically to a further light guide and thence to a cold light source (E), and a removable optical viewing system 17. The probe 16 consists of three coaxial thin-walled tubes made of, for example, stainless steel. In the tube 28 the liquid coolant flows to an evaporator 29, which may consist of a thermally conductive wire coil, which establishes good thermal contact between the evaporating coolant and the probe nose 30 surrounding the evaporator. The nose 30 may be unscrewed from the probe and replaced by other noses having a shape appropriate to a particular operation. The gas produced in the nose escapes through the space 31a between the innermost tube 28 and the central tube 31. The space 32a between the central tube 31 and the outermost tube 32 is evacuated. A heater coil 33 can be used to heat up the nose to release it from frozen tissue and is operable by a switch 36. The probe nose can be given a shape such that it has a piercing portion which is visible through the viewing system 17, Fig. 2, the invisible parts of the nose being rounded off. The probe carries a finger rest 22 having a cone 22a onto which a device (21), Fig. 2 (not shown) may be connected for treatment of tissues frozen by the probe. The finger rest 22 and treatment device (21) are axially movable relative to the probe 16, selected relative positions being fixed by a control 24. A switch 35, when closed, opens the electromagnetic valve between the gas discharge hose and the suction pump so that gas may escape from the system and coolant may flow to the probe from the container 14 which is pressurised. The handle also carries a heating element switched on by switch 35, to heat the outflowing gas to about room temperature so that the gas discharge hose remains flexible. The container 14 has an evacuatable jacket and a pressure tight cover 15 carrying a regulating and safety valve 27 and a thermoelectric device 26 to indicate when the container needs refilling. The appliance may be connected to an automatic replenishment device (50), Fig 5 (not shown).