Flexible catheter cryosurgical system

• US 6,035,657 A
• Filed: 04/07/1999
• Issued: 03/14/2000
• Est. Priority Date: 10/12/1995
• Status: Expired due to Term

• Current Assignee: Coopersurgical Incorporated (The Cooper Cos., Inc.)
• Original Assignee: CryoGen, Inc. (Endo International PLC), U.S. Department of Commerce (Government of the United States of America)
• Inventors: Marquardt, Eric, Radebaugh, Ray, Dobak, John D. III
• Primary Examiner(s): CAPOSSELA, RONALD C
• Application Number:
  US09/287,669
• Time in Patent Office: 342 Days
• Field of Search: 165/164, 165/80.4, 165/81, 62/51.2, 62/50.7, 62/293, 606/21
• US Class Current: 62/293
• CPC Class Codes: A61B 18/02 by cooling, e.g. cryogenic techniques devices for cooling specific reflex points of the body within cell-life limits A61H39/06
• CPC Class Codes: A61B 2018/0212 using an instrument inserted into a body lumen, e.g. catheter
• CPC Class Codes: A61B 2018/0275 using porous elements
• CPC Class Codes: A61B 2018/0281 using a tortuous path, e.g. formed by fins or ribs
• CPC Class Codes: C09K 2205/12 Hydrocarbons
• CPC Class Codes: C09K 2205/122 Halogenated hydrocarbons
• CPC Class Codes: C09K 2205/13 Inert gases
• CPC Class Codes: C09K 2205/132 containing nitrogen
• CPC Class Codes: C09K 5/045 containing only fluorine as halogen
• CPC Class Codes: F25B 2309/003 characterised by construction or composition of the regenerator
• CPC Class Codes: F25B 2309/021 with a cryosurgical probe tip having a specific construction
• CPC Class Codes: F25B 2309/022 characterised by the expansion element
• CPC Class Codes: F25B 2309/023 with two stage expansion
• CPC Class Codes: F25B 2400/12 Inflammable refrigerants
• CPC Class Codes: F25B 9/006 the refrigerant containing more than one component F25B9/004 takes precedence
• CPC Class Codes: F25B 9/02 using Joule-Thompson effect; using vortex effect
• CPC Class Codes: F28D 7/12 the surrounding tube being closed at one end, e.g. return type F28D7/14 takes precedence
• CPC Class Codes: F28F 13/06 by affecting the pattern of flow of the heat-exchange media F28F13/003 takes precedence; static flow control means in header boxes F28F9/026
• CPC Class Codes: F28F 21/082 from steel or ferrous alloys
• CPC Class Codes: F28F 21/085 from copper or copper alloys
• CPC Class Codes: F28F 2260/02 : having microchannels

Abstract

A microminiature laminated heat exchanger for use in a cryogenic probe, and a method of manufacture. The heat exchanger has high and low pressure flow patterns etched into oxygen free copper sheets, with the flow patterns being tortuous paths promoting turbulent flow. The sheets containing the flow patterns are bonded into a laminated assembly in the shape of a cylinder, with a high pressure inlet and a low pressure outlet in a first end, and a high pressure outlet and a low pressure inlet in a second end. The high pressure flow path lies alongside the low pressure flow path, with flow in the two paths being in opposite directions, to accomplish counterflow heat exchange.

Claims

1. A miniature cryosurgical system, comprising:

a compressor for pressurizing a gas mixture;

a flexible, dual lumen, coaxial catheter, said catheter comprising;

a hollow elongated inner supply tube, said supply tube having a proximal end connected in fluid flow communication with an outlet of said compressor;

a hollow elongated outer return tube, said return tube having a proximal end connected in fluid flow communication with an inlet of said compressor;

a heat exchanger mounted in fluid flow communication with said compressor and said catheter, said heat exchanger comprising;

a high pressure passageway, said high pressure passageway having an inlet port connected in fluid flow communication with said outlet of said compressor, said high pressure passageway having a distal outlet port;

a low pressure passageway, said low pressure passageway lying substantially alongside said high pressure passageway, said low pressure passageway having a distal inlet port, said low pressure passageway having an outlet port connected in fluid flow communication with said inlet of said compressor; and

a substantially annular insulating jacket integrally formed within said heat exchanger by formation of substantially annular channels positioned radially outwardly from said high pressure passageway and said low pressure passageway, said annular insulating jacket being evacuated;

wherein the direction of flow from said inlet port to said outlet port of said high pressure passageway is substantially opposite to the direction of flow from said inlet port to said outlet port of said low pressure passageway;

an expansion element mounted within said distal end of said return tube, an inlet of said expansion element being connected in fluid flow communication with said distal outlet port of said high pressure passageway of said heat exchanger, an outlet of said expansion element being connected in fluid flow communication with said at least one distal inlet port of said low pressure passageway of said heat exchanger; and

a heat transfer body mounted to said distal end of said return tube adjacent said expansion element, said heat transfer body having an inner surface exposed to said outlet of said expansion element and an outer surface exposed to ambient, for transferring heat from said outer surface of said heat transfer body to said inner surface of said heat transfer body.

2. A miniature cryosurgical system, comprising:

a compressor for pressurizing a gas mixture;

a flexible, dual lumen, coaxial catheter, said catheter comprising;

a hollow elongated inner supply tube, said supply tube having a proximal end connected to an outlet of said compressor;

a hollow elongated outer return tube, said return tube having a proximal end connected to an inlet of said compressor;

a heat exchanger mounted within a distal end of said return tube, said heat exchanger comprising;

a laminated assembly of a plurality of plates of heat conductive material;

a high pressure passageway through said laminated assembly, said high pressure passageway having an inlet port connected to a distal end of said supply tube, said high pressure passageway having a distal outlet port;

a low pressure passageway through said laminated assembly, said low pressure passageway lying substantially alongside said high pressure passageway, said low pressure passageway having a distal inlet port, said low pressure passageway having an outlet port in fluid flow communication with said return tube; and

a substantially annular insulating jacket integrally formed within said heat exchanger by formation of substantially annular channels through said plates, said substantially annular channels being positioned radially outwardly from said high pressure passageway and said low pressure passageway, said annular insulating jacket being evacuated;

wherein the direction of flow from said inlet port to said outlet port of said high pressure passageway is substantially opposite to the direction of flow from said inlet port to said outlet port of said low pressure passageway; and

wherein each said passageway is arranged to create a tortuous flow path, to ensure turbulent flow of cryogenic gas therethrough;

an expansion element mounted within said distal end of said return tube, an inlet of said expansion element being connected to said distal outlet port of said high pressure passageway of said heat exchanger, an outlet of said expansion element being in fluid flow communication with said at least one distal inlet port of said low pressure passageway; and

a heat transfer body mounted to said distal end of said return tube adjacent said expansion element, said heat transfer body having an inner surface exposed to said outlet of said expansion element and an outer surface exposed to ambient, for transferring heat from said outer surface of said heat transfer body to said inner surface of said heat transfer body.

3. A miniature cryosurgical system, comprising:

a compressor for pressurizing a gas mixture;

a flexible, dual lumen, coaxial catheter, said catheter comprising;

a hollow elongated inner supply tube, said supply tube having a proximal end connected to an outlet of said compressor;

a hollow elongated outer return tube, said return tube having a proximal end connected to an inlet of said compressor;

a heat exchanger mounted within a distal end of said return tube, said heat exchanger comprising;

a plurality of plates of heat conductive material laminated in a stack along a longitudinal axis to form an elongate laminated assembly;

a high pressure passageway through said laminated assembly, said high pressure passageway comprising a first plurality of holes through each said plate, said high pressure passageway having an inlet port connected to a distal end of said supply tube, said high pressure passageway having a distal outlet port;

a low pressure passageway through said laminated assembly, said low pressure passageway lying substantially alongside said high pressure passageway, said low pressure passageway comprising a second plurality of holes through each said plate, said low pressure passageway having a distal inlet port, said low pressure passageway having an outlet port in fluid flow communication with said return tube; and

a plurality of spacers laminated alternatingly between said plates to form a high pressure flow chamber and a low pressure flow chamber between each pair of adjacent said plates, wherein each said spacer includes a partition dividing said high pressure flow chamber from said low pressure flow chamber;

wherein the direction of flow from said inlet port to said outlet port of said high pressure passageway is substantially opposite to the direction of flow from said inlet port to said outlet port of said low pressure passageway; and

wherein each said passageway is arranged to create a tortuous flow path, to ensure turbulent flow of cryogenic gas therethrough;

an expansion element mounted within said distal end of said return tube, an inlet of said expansion element being connected to said distal outlet port of said high pressure passageway of said heat exchanger, an outlet of said expansion element being in fluid flow communication with said at least one distal inlet port of said low pressure passageway; and

a heat transfer body mounted to said distal end of said return tube adjacent said expansion element, said heat transfer body having an inner surface exposed to said outlet of said expansion element and an outer surface exposed to ambient, for transferring heat from said outer surface of said heat transfer body to said inner surface of said heat transfer body;

wherein said partitions on said spacers are located to transversely offset adjacent said high pressure flow chambers from each other, and to transversely offset adjacent said low pressure flow chambers from each other, to direct substantial portions of each said passageway substantially transverse to said longitudinal axis of said heat exchanger.

4. A miniature cryosurgical system, comprising:

a compressor for pressurizing a gas mixture;

a flexible, dual lumen, coaxial catheter, said catheter comprising;

a hollow elongated inner supply tube, said supply tube having a proximal end connected to an outlet of said compressor;

a hollow elongated outer return tube, said return tube having a proximal end connected to an inlet of said compressor;

a heat exchanger mounted within a distal end of said return tube, said heat exchanger comprising;

an axially stacked assembly of laminated flat plates and flat spacers, said plates being alternated with said spacers;

a first plurality of holes formed through said plates, forming a passageway for turbulent flow of high pressure cryogenic gas, each said high pressure hole being transversely offset from a corresponding high pressure hole in each adjacent said plate;

a second plurality of holes formed through said plates, forming a passageway for turbulent flow of low pressure cryogenic gas, each said low pressure hole being transversely offset from a corresponding low pressure hole in each adjacent said plate;

a substantially annular channel formed through each said plate and each said spacer to integrally form a substantially annular insulating jacket within said laminated assembly, said substantially annular channel being positioned radially outwardly from said high pressure and low pressure holes, said annular insulating jacket being evacuated;

a plurality of spacers laminated to a first end of said stacked assembly, to create a manifold for connection of high pressure and low pressure gas lines to said heat exchanger; and

an end plate laminated to a second end of said stacked assembly, said end plate having an orifice therethrough in flow communication with said high pressure holes;

wherein the direction of flow from said inlet port to said outlet port of said high pressure passageway is substantially opposite to the direction of flow from said inlet port to said outlet port of said low pressure passageway; and

a heat transfer body mounted to said distal end of said return tube adjacent said end plate, said heat transfer body having an inner surface exposed to said outlet of said orifice and an outer surface exposed to ambient, for transferring heat from said outer surface of said heat transfer body to said inner surface of said heat transfer body.