Cryogenic biological apparatus

Claim 2

A cryogenic system for use in cryobiological applications including, a source of high-pressure gas, a probe including a nozzle for ejecting a stream of cryogenic fluid against tissue to be frozen, and cooling means including a cryogenic heat exchanger having a Joule Thompson expansion orifice intermediate said gas source and said nozzle for cooling said gas to a cryogenic temperature before ejection from said nozzle as said stream of cryogenic fluid.

Claim 3

A cryogenic system for use in cryobiological applications including, a source of high-pressure gas, a probe including a nozzle for ejecting a stream of cryogenic fluid against tissue to be frozen, cooling means intermediate said gas source and said nozzle for cooling at least a portion of said gas to a cryogenic temperature before ejection thereof from said nozzle as said stream of cryogenic fluid, said cooling means including means for dividing said high-pressure gas into first and second streams, means for cooling said first stream, means for cooling said second stream in heat exchange with said first stream, means for venting said first stream after warming said first stream in heat exchange with said second stream, and means connecting said second stream to said nozzle for ejection therefrom as said stream of cryogenic fluid.

Claim 4

A cryogenic system for use in cryobiological applications including, a source of high-pressure gas, a probe including a nozzle for ejecting a stream of cryogenic fluid against tissue to be frozen, cooling means intermediate said gas source and said nozzle for cooling at least a portion of said gas to a cryogenic temperature before ejection thereof from said nozzle as said stream of cryogenic fluid, said cooling means including means for dividing said high-pressure gas into first and second streams, means for cooling said first stream, means for cooling said second stream in heat exchange with said first stream, means for venting said first stream after warming said first stream in heat exchange with said second stream, and means connecting said second stream to said nozzle for ejection therefrom as said stream of cryogenic fluid.

Claim 5

The system as claimed in claim 2 wherein said means for cooling said first stream comprises a first heat exchanger and a Joule Thompson expansion orifice, and said means for cooling said second stream comprises a second heat exchanger connected to said nozzle.

Claim 6

The system as claimed in claim 3 wherein said first and second heat exchangers comprise wound tubular coils in heat exchange relationship with each other, and at least one of said coils is composed of finned tubing.

Claim 7

A cryobiological probe for use in generating and directing a cryogenic fluid against tissue comprising: a. a hollow, elongated casing forming a handle having forward and rearward portions, b. a gas supply tube extending into said rearward portion, c. means within said casing and connected to said supply tube for dividing said gas into first and second streams, d. means within said casing forming a first heat exchanger and a Joule Thompson orifice for cooling said first stream, e. means within said casing forming a second heat exchanger for cooling said second stream in heat exchange with said first cooled stream whereby said first stream is warmed and said second stream is cooled to form a cryogenic fluid, f. a nozzle located in the forward portion of said casing and connected to said second heat exchanger for ejecting said second stream as a jet of cryogenic fluid, and g. means for exhausting said warmed first stream from said probe after heat exchange with said second stream.

Claim 8

A cryobiological probe for use in generating and directing a cryogenic fluid against tissue comprising: a. a hollow, elongated casing forming a handle having forward and rearward portions, b. a gas supply tube extending into said rearward portion, c. means within said casing and connected to said supply tube for dividing said gas into first and second streams, d. means within said casing forming a first heat exchanger and a Joule Thompson orifice for cooling said first stream, e. means within said casing forming a second heat exchanger for cooling said second stream in heat exchange with said first cooled stream whereby said first stream is warmed and said second stream is cooled to form a cryogenic fluid, f. a nozzle located in the forward portion of said casing and connected to said second heat exchanger for ejecting said second stream as a jet of cryogenic fluid, and g. means for exhausting said warmed first stream from said probe after heat exchange with said second stream.

Claim 9

The cryobiological probe as claimed in claim 5 including means forming a liquid chamber for collecting cryogenic liquid produced by said Joule Thompson orifice, and means for passing said second stream in heat exchange relationship with said cryogenic liquid so as to at least partially liquefy the gas in said second stream.

Claim 10

The cryobiological probe as claimed in claim 6 wherein said first heat exchanger comprises finned tubing helically wound about a first mandrel, and a sleeve surrounding said finned tubing forming said liquid chamber.

Claim 13

The method as claimed in claim 8 wherein step (d) includes cooling said first stream to its liquefaction temperature so as to form a cryogenic liquid, and step (e) includes cooling said second stream to its liquefaction temperature so as to liquefy substantially all of said second stream to form a jet of cryogenic liquid as it is ejected from said nozzle.