Abstract: To insulate the supply lines to an operating tip of a cryogenic surgical instrument, a coaxial assembly of tubes is provided, the inner one being connected to a supply of cryogenic liquid, such as liquid nitrogen; the space between the outer wall of the inner tube and the next tube forming a return line for evaporated cryogenic liquid which is vented to the atmosphere; and the space between the outermost one of the coaxial tubes and the intermediate tube containing a gas such as normal butane, introduced at atmospheric pressure and which has high heat-insulating properties, and which solidifies, or sublimates, to avoid a vacuum and make possible construction of the supply lines as plastic, preferably polyamide tubes, retaining flexibility in use.

Abstract: Viable fluids such as blood components are rapidly frozen in plastic or the like pouches for transportation and/or storage by placing a flat pouch slack filled with fluid between two substantially planar parallel restraining surfaces such as metal plates of greater perimeter than the flattened slack filled pouch which are rigid enough to prevent sagging of the pouch when it is vertically disposed and flexible enough to accommodate expansion of the pouch flat sides during the freezing operation. The restraining surfaces are retained against separation by retaining means applied against at least a portion of the outer surfaces of each pouch restraining means and the entire assembly is immersed in a cryogenic medium to rapidly freeze the fluid.

Abstract: A small, self-contained, disposable cryosurgical probe has a pencil-like housing with a refrigerant-containing cartridge in the housing and a hollow tip projecting from the housing. A small diameter capillary tube has one end in the housing opposite the cartridge and its other end extending into the tip with the intervening length of the tube formed into a multi-turn coil. The refrigerant is conducted from the cartridge through the tube to the probe tip and the temperature of the refrigerant is stabilized so as to maintain a substantially uniform mass flow rate of refrigerant through the tube to the tip.

Abstract: A portable refrigerating unit has a condenser coil which may be inserted directly into the drying chamber of a freeze drying apparatus. A flexible tube is utilized to convey refrigerant to and from the condenser coil. The flexible tube and the condenser coil are connected through a closure member, which provides a vacuum tight seal for the drying chamber of the freeze drying apparatus. The closure member may be removed from the condenser coil, so that various closure sizes may be utilized and so that the condenser coil may be utilized as an immersible refrigerating device.