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US 5,946,920 AGranted
Method and apparatus for supplying liquid cryogen
AssigneeSpembly Cryosurgery Limited
InventorBrian K. R. Clarke
Life of this patent
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AssigneeSpembly Cryosurgery Limited
InventorBrian K. R. Clarke
Estimating the term…
A method and apparatus are described for controlling the rate of supply of a liquid cryogen, for example, for cryosurgical use. The flow rate of the liquid cryogen is controlled by controlling variably the pressure propellant gas acting directly or indirectly on the liquid cryogen. A means for controlling the propellant gas pressure may comprise a source of pressurised propellant gas, and control valve means coupled between the source and the liquid cryogen reservoir chamber for controlling the pressure supplied to the reservoir chamber. A plurality of reservoir chambers may be driven by a common pressure source. When the pressure source is a pressure raising system, the cryogen reservoir chambers may be contained within the vessel of the pressure raising system. A feedback control arrangement is also described for controlling the cryogen flow rate in response to a measured characteristic associated with, or affected by, the cryogen flow rate. For example, in cryosurgery, the measured characteristic may be temperature as measured by a temperature probe.
Apparatus for supplying liquid cryogen, wherein the flow rate of the liquid cryogen is controlled by controlling variably the pressure of propellant gas acting directly or indirectly on the liquid cryogen.
Apparatus for supplying a liquid cryogen to cryosurgical apparatus, the apparatus comprising means for supplying the liquid cryogen to the cryosurgical apparatus and pressure controlling means whereby the rate of flow of the cryogen to the cryosurgical apparatus can be varied, the pressure controlling means comprising means for providing a supply of gas in communication with the liquid cryogen, and means for varying the pressure of said gas, whereby to vary the rate of flow liquid cryogen to the cryosurgical apparatus.
Cryosurgical apparatus comprising:
A method of controlling the rate of supply of liquid cryogen for a cryogen supply, the method comprising controlling variably the pressure of propellant gas acting directly or indirectly on the liquid cryogen, to control the flow rate.
A method of controlling the rate of supply of liquid cryogen to cryosurgical apparatus, in which the flow of the liquid is effected by the pressure of a gas acting directly or indirectly on the liquid, the method comprising controlling the pressure of the gas whereby to control the rate of flow of the liquid.
A method of controlling the supply of liquid cryogen to a cryosurgical device, the method comprising:
Dependencies are inferred from the claim text.