Thawing of cryosurgical apparatus
AssigneeSpembly Cryosurgery Limited
InventorBrian Kevin Roderick Clarke
Life of this patent
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Abstract
Apparatus is described for feeding a cryosurgical device by passing a liquid cryogen (e.g. liquid nitrogen) through the device to produce cooling by vaporization, and to enable thawing of the device by passing a heated inert thaw gas (e.g. nitrogen gas) through the device when the liquid cryogen is turned off. The thaw gas is passed through the device in the same direction of flow as the liquid cryogen. The apparatus can supply a plurality of cryosurgical devices, and provide independent control of cryogen and thaw for each probe. Novel valve arrangements are also disclosed for controlling the supply of liquid cryogen and the supply of the thaw gas.
Claims19
Cryosurgical apparatus comprising:
- a cryosurgical device having a tip region and a liquid cryogen pathway transporting liquid cryogen through the tip region to cool the tip region by vaporization of the cryogen, the pathway including an inlet and an outlet;
- a liquid cryogen, supply coupled to said liquid cryogen pathway inlet for selectively supplying the liquid cryogen through the inlet in order to produce said cooling at said tip region;
- an inert gas supply coupled to said liquid cryogen pathway inlet for selectively supplying an inert thaw gas after said supply of cryogen has been stopped at the end of surgery, to thaw the cryosurgical device;
- an exhaust line coupled to said outlet of the pathway of said cryosurgical device.
Apparatus according to claim 11 wherein said liquid cryogen supply comprises a supply of liquid nitrogen.
Apparatus for supplying liquid cryogen and heated thaw gas cryosurgical device of a type having a tip region and a pathway for transporting liquid cryogen through the tip region to cool the tip region by vaporization of the cryogen, the pathway having an inlet and an outlet, wherein said apparatus comprises:
- a first conduit for coupling to said liquid cryogen pathway inlet of the cryosurgical device;
- a second conduit for coupling to said liquid cryogen pathway outlet of the cryosurgical device;
- a cryogen delivery control valve;
- a liquid cryogen supply coupled to said first conduit, to selectively supplying liquid cryogen to the cryosurgical device under the control of said cryogen delivery control valve;
- a thaw gas delivery control valve;
- an inert gas supply coupled to said first conduit, to selectively supply under the control of said gas delivery control valve a thaw gas to thaw the cryosurgical device after the supply of cryogen has been stopped at the end of surgery, whereby said apparatus is operable to supply said liquid cryogen and thereafter said thaw gas through said first conduit.
Cryosurgical apparatus comprising:
- first cryosurgical device having a first tip region and a first liquid cryogen pathway for transporting liquid cryogen through the tip region to cool the tip region by vaporization of the cryogen, the pathway including a first inlet and a first outlet;
- a second cryosurgical device having a second tip region and a second cryogen pathway for transporting liquid cryogen through the tip region to cool the tip region by vaporization of the cryogen, the pathway including a second inlet and a second outlet;
- a liquid cryogen supply system;
- a first cryogen delivery valve for controlling the supply of liquid cryogen to the first cryosurgical device;
- a second cryogen delivery valve for controlling the supply of liquid cryogen to the second cryosurgical device;
- an inert gas supply for supplying thaw gas;
- a first thaw gas delivery valve coupled between said inert gas supply and said first liquid cryogen pathway inlet of said first cryosurgical device for controlling the supply of thaw gas to thaw the first cryosurgical device after the first cryogen delivery valve has been turned off;
- and
- a second thaw gas delivery valve coupled between said inert gas supply and said second liquid cryogen-pathway inlet of said second cryosurgical device for controlling the supply of thaw gas to thaw the second cryosurgical device after the second cryogen delivery valve has been turned off.
Dependencies are inferred from the claim text.