Catheter with a dual balloon structure for creating and applying an ablation zone to tissue

Abstract

The ablation catheter and system include a coaxial catheter shaft having an inner lumen for delivering an ablative agent and an outer lumen for circulating a coolant around the catheter. Inductive heating is used to heat the compartment and vaporize the fluid therein by winding a coil around the ferromagnetic compartment and supplying an alternating current to the coil. A magnetic field is formed in the area surrounding the compartment, which induces an electric current in the compartment, heating the compartment and vaporizing the fluid therein. A positioning element helps to keep the device in place relative to the target tissue and also prevents the ablative agent from reaching normal tissue.

Description

[0001] This application is a divisional application of application number 201780044101.0, application date May 19, 2017, and invention name “Ablation catheter with integrated cooling”.

[0002] Cross-references

[0003] This application claims priority to U.S. Provisional Patent Application No. 62 / 425,144, filed on November 22, 2016, entitled “Methods and Systems for Ablation,” and U.S. Provisional Patent Application No. 62 / 338,871, filed on May 19, 2016, entitled “Cooled Coaxial Ablation Catheter.”

[0004] This application is also a continuation-in-part of U.S. patent application No. 15 / 144,768, filed on May 2, 2016, entitled “Induction-Based Micro-Volume Heating System,” which is a continuation-in-part of U.S. patent application No. 14 / 594,444, filed on January 12, 2015, entitled “Method and Apparatus for Tissue Ablation,” and published on February 7, 2017 as U.S. Patent No. 9,561,068, which is a continuation-in-part of U.S. patent application No. 14 / 158,687, filed on January 17, 2014, with the same title and published on February 7, 2017 as U.S. Patent No. 9,561,067, which in turn relies on U.S. Provisional Patent Application No. 61 / 753,831, filed on January 17, 2013, with the same title.

[0005] U.S. patent application 14 / 158,687 is also a continuation-in-part of U.S. patent application 13 / 486,980, entitled “Method and Apparatus for Tissue Ablation,” filed on June 1, 2012 and published on February 7, 2017 as U.S. Patent 9,561,066, which in turn relies on U.S. Provisional Patent Application 61 / 493,344 of the same title filed on June 3, 2011.

[0006] U.S. Patent Application No. 13 / 486,980 is also a continuation-in-part of U.S. Patent Application No. 12 / 573,939, filed on October 6, 2009, entitled “Method and Apparatus for Tissue Ablation,” which in turn relies on U.S. Provisional Patent Application No. 61 / 102,885, filed on October 6, 2008, of the same title.

[0007] All of the above applications are incorporated herein by reference in their entirety. Technical Field

[0008] The present invention relates to devices configured to generate and deliver vapor for ablation therapy. More particularly, the present application relates to systems and methods including cooling catheters and vapor generation for ablation therapy of specific organ systems. Background Art

[0009] Ablation, as used herein, involves the removal or destruction of body tissue via the introduction of a destructive agent such as radiofrequency energy, laser energy, ultrasound energy, cryogens, or steam. Ablation is often used to eliminate diseased or unwanted tissue, such as, but not limited to, cysts, polyps, tumors, hemorrhoids, and other similar lesions.

[0010] Steam-based ablation systems, such as those disclosed in U.S. Pat. Nos. 9,615,875, 9,433,457, 9,376,497, 9,561,068, 9,561,067, and 9,561,066, disclose ablation systems. The system controllably delivers steam toward target tissue through one or more lumens. One problem is that all such steam-based ablation systems may overheat or burn healthy tissue. Steam passing through a channel in a body cavity heats the surface of the channel and may cause the outer surface of the medical instrument (rather than the end of the operating instrument itself) to become overheated. As a result, the physician may accidentally burn healthy tissue when the outer portion of the device (rather than the distal operating end of the instrument) accidentally contacts healthy tissue. U.S. Pat. Nos. 9,561,068, 9,561,067, and 9,561,066 are therefore incorporated herein by reference.

[0011] Furthermore, it is often desirable to quickly cool the treatment area after applying steam or some other ablative agent. However, current systems rely primarily on a natural cooling process, which prolongs treatment time. Alternatively, current medical methods flush the area with fluid, but require the use of a separate medical tool, thereby complicating the process and also prolonging treatment time.

[0012] It is therefore desirable to have a steam-based ablation device that has safety mechanisms integrated into the device itself that prevent unwanted burning during use. It is further desirable to provide a way to enhance the natural cooling process to thereby reduce treatment time. Finally, it is desirable to provide an easy-to-implement cooling mechanism that does not rely on a separate medical tool to deliver fluid to cool the treatment area. Summary of the invention

[0013] The present specification discloses a catheter suitable for ablating cardiac tissue, comprising: a first axis having a first cavity and an outer surface extending from a proximal end of the catheter to a first point positioned before a distal end of the catheter; a second axis having a second cavity extending from the proximal end of the catheter to a second point at or before the distal end of the catheter, wherein the second axis is positioned in the first axis; a balloon positioned between the first point and the second point; and a channel extending through the first axis, wherein the channel is connected to the balloon fluid.

[0014] Optionally, the catheter further comprises a plurality of sensors positioned at the distal end of the catheter, wherein the plurality of sensors are adapted to generate signals representative of cardiac tissue associated with the arrhythmia. Optionally, the second point is positioned between the balloon and the plurality of sensors.

[0015] Optionally, after the outer surface of the first shaft terminates at the first point, the second shaft and the passage extend beyond the first point.

[0016] The present specification also discloses an ablation system suitable for ablating cardiac tissue, comprising: a steam generating system suitable for generating steam; a catheter comprising: a first axis having a first cavity extending from a proximal end of the catheter to a first point positioned before a distal end of the catheter; a second axis having a second cavity extending from the proximal end of the catheter to a second point at or before the distal end of the catheter, wherein the second axis is positioned in the first axis; a balloon positioned between the first point and the second point; and a channel extending through the first axis, wherein the channel is fluidically connected to the balloon and to the steam generating system; and a controller in data communication with the steam generating system, wherein the controller is suitable for controlling the amount of steam entering the channel.

[0017] Optionally, the controller is further adapted to control at least one of an amount of pressure in the bladder and an amount of air exiting the bladder and passing through the passageway.

[0018] Optionally, the ablation system further comprises a plurality of sensors positioned at the distal end of the catheter, wherein the plurality of sensors are adapted to generate signals representative of cardiac tissue associated with the arrhythmia.

[0019] Optionally, the controller is adapted to cause an amount of air delivered from the air source through the passage to fill the bladder to a first pressure. Optionally, the controller is adapted to cause an amount of steam to be delivered from the steam generating system through the passage to fill the bladder to a second pressure, wherein the second pressure is different from the first pressure. Optionally, the controller is adapted to cause an amount of air to be removed from the bladder to maintain the second pressure within 25% of the first pressure.

[0020] Optionally, the ablation system further comprises a water reservoir, wherein the controller is further adapted to control the amount of water from the water reservoir and passing through the first axis. Optionally, the controller is further adapted to control the amount of water from the water reservoir and passing through the second axis.

[0021] The present specification also discloses a method for ablating cardiac tissue, comprising: positioning the distal end of a catheter proximate to cardiac tissue, wherein the catheter comprises: an outer shaft having a first cavity extending from the proximal end of the catheter to a first point positioned before the distal end of the catheter; an inner shaft having a second cavity extending from the proximal end of the catheter to a second point at or before the distal end of the catheter, wherein the inner shaft is positioned in the outer shaft; a balloon positioned between the first point and the second point; and a steam channel extending through the first shaft, wherein the steam channel is fluidically connected to the balloon and to a steam generating system; and activating a controller to fill the balloon to a first pressure; and activating the controller to allow steam to enter the steam channel from the steam generating system and into the balloon.

[0022] Optionally, the method further comprises determining a region of cardiac tissue associated with the arrhythmia using a plurality of sensors positioned at the distal end of the catheter.

[0023] Optionally, activating the controller to cause steam to enter the steam passage from the steam generating system further comprises activating the controller to cause the bladder to fill to a second pressure, wherein the second pressure is different from the first pressure. Optionally, the method further comprises, using the controller, causing a certain amount of air to be removed from the bladder to maintain the second pressure within 25% of the first pressure.

[0024] Optionally, the method further comprises applying the bladder containing steam to the cardiac tissue. Optionally, activating a controller to cause water to enter at least one of the outer shaft and the inner shaft from a water source. Optionally, the method further comprises activating a controller to cause water to enter the outer shaft and the inner shaft from a water source.

[0025] Optionally, the method further comprises, using a controller, regulating the amount of steam entering the bladder from the steam generating system via the steam passage to maintain the second pressure within 25% of the first pressure.

[0026] The above and other embodiments of the present invention are described in more detail with reference to the accompanying drawings and in detail as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] These and other features and advantages of the present invention will be better understood with reference to the detailed description taken in conjunction with the accompanying drawings, in which:

[0028] Figure 1A An ablation device according to an embodiment of the present specification is shown;

[0029] Figure 1B Another embodiment of a catheter is shown for use in Figure 1A ablation devices;

[0030] Figure 2A A longitudinal cross section of an ablation device is shown with ports distributed thereon;

[0031] Figure 2B shows a cross section of a port on an ablation device according to an embodiment of the present specification;

[0032] Figure 2C shows a cross section of a port on an ablation device according to another embodiment of the present specification;

[0033] Figure 2D A catheter of an ablation device according to an embodiment of the present specification is shown;

[0034] Figure 2E A catheter of an ablation device according to another embodiment of the present specification is shown;

[0035] Figure 2F A catheter of an ablation device according to another embodiment of the present specification is shown;

[0036] Figure 2G is a flow chart according to one embodiment of the present specification, which lists the steps involved in a hollow tissue or organ ablation process using an ablation device;

[0037] Figure 2H An ablation device in the form of a catheter extending from a conventional snare handle according to an embodiment of the present specification is shown;

[0038] Fig.2I A cross-section of an ablation device in the form of a catheter extending from a conventional handle, with a pre-attached cable, is shown according to another embodiment of the present description.

[0039] Figure 2J An ablation device in the form of a catheter extending from a conventional esophageal probe is shown according to an embodiment of the present description.

[0040] Figure 3 is a flow chart detailing the steps involved in one embodiment of a method of tissue ablation;

[0041] Figure 4A A multi-lumen ablation catheter according to an embodiment is shown;

[0042] Figure 4B The use of the embodiment according to this specification is shown Figure 4A The basic process steps of ablation catheter;

[0043] Figure 5A is a first diagram showing a process of ablating tissue according to an embodiment;

[0044] Figure 5B is a second diagram showing a process of ablating tissue according to another embodiment;

[0045] Figure 5C It shows the Figure 5A and 5B A flowchart of the multiple steps involved in the ablation procedure;

[0046] Fig. 6A is a flow chart showing a method for ablating body tissue according to one embodiment of the present specification;

[0047] Figure 6B is a flow chart showing a method for ablating body tissue according to another embodiment of the present specification,

[0048] Figure 6C is a flow chart showing a method for ablating body tissue according to yet another embodiment of the present specification.

[0049] Fig. 7A is a schematic diagram of a water cooling conduit according to an embodiment of the present specification;

[0050] Figure 7B yes Fig. 7A A cross-sectional view of a water-cooling guide tube shaft;

[0051] Fig. 8A A first ablation catheter according to an embodiment of the present specification is shown;

[0052] Figure 8B yes Fig. 8A a cross-sectional view of the shaft or elongated body of the catheter;

[0053] Fig.9A A second ablation catheter according to an embodiment of the present specification is shown;

[0054] Fig. 9B yes Fig.9A a cross-sectional view of the shaft or elongated body of the catheter;

[0055] Fig. 10A A third ablation catheter according to an embodiment of the present specification is shown;

[0056] Fig. 10B yes Fig. 10A a cross-sectional view of the shaft or elongated body of the catheter;

[0057] Fig.11 An ablation catheter according to an embodiment of the present specification is shown;

[0058] Fig.12 shows a connection between a syringe and a catheter according to an embodiment of the present specification;

[0059] Fig.13A is a schematic diagram of a connector and a heating compartment of a catheter according to another embodiment of the present specification;

[0060] Fig. 13B Shows Fig.13A A coil and a ferromagnetic core positioned in a heating compartment as shown in;

[0061] Fig. 13C yes Fig.13A Assembly view of the connection parts and the heating compartment;

[0062] Fig.13D yes Fig.13A A cross-sectional view of the connection piece and the heating compartment;

[0063] Fig.14A is a schematic diagram of a connector and a heating compartment of a catheter according to another embodiment of the present specification;

[0064] Fig. 14B is a schematic diagram of a connector and a heating compartment of a catheter according to another embodiment of the present specification;

[0065] Fig.15A The use of inductive heating to heat the compartment is shown;

[0066] Fig. 15B is a flow chart listing the steps for heating a compartment using induction heating;

[0067] Fig.16A An embodiment of a coil is shown, which is used for inductive heating of the vapor ablation system of the present specification;

[0068] Fig. 16B An embodiment of a catheter handle is shown, which is used for inductive heating of the steam ablation system of the present specification;

[0069] Fig. 16C shows a disassembled coil component and heating compartment of an induction heating system according to one embodiment of the present specification;

[0070] Fig.16D An assembled induction heating system is shown, comprising Fig. 16C The coil assembly and the heating compartment;

[0071] Fig.16E A first conventional endoscope handle is shown for use with the induction heating system of the present specification;

[0072] Fig.16F A second conventional endoscope handle is shown for use with the induction heating system of the present specification;

[0073] Figure 16G shows a disassembled coil component and heating compartment of an induction heating system for use with an endoscope according to one embodiment of the present specification;

[0074] Fig.16H An assembled induction heating system is shown for use with Figure 16G for use with an endoscope comprising a coil assembly and a heating compartment;

[0075] Fig.16I shows a disassembled coil component and heating compartment of an induction heating system for use with an endoscope according to one embodiment of the present specification;

[0076] Fig.16J shows the use of Fig.16I An assembled induction heating system for use with a coil assembly and an endoscope having a heating compartment;

[0077] Figure 16K An inductive heating system including a handle configured to be attached to a conventional endoscope handle according to one embodiment of the present specification is shown;

[0078] Figure 16L is a cross-sectional view of an induction heating system according to one embodiment of the present specification, the system including a handle and having a wheel mechanism for moving a coil assembly relative to a heating compartment;

[0079] Figure 16M An inductive heating system according to one embodiment of the present specification is shown, comprising a heating compartment in a first position relative to a coil assembly;

[0080] Fig.16N Shows Figure 16M an induction heating system, the heating compartment being in a second position relative to the coil assembly;

[0081] Fig.16O An induction heating system according to one embodiment of the present specification is shown, comprising a first handle component in a first position relative to a second handle component;

[0082] Figure 16P Shows Fig.16O The induction heating system of the present invention, the first handle member is in a second position relative to the second handle member;

[0083] Figure 16Q shows a Luer lock mechanism at the distal end of the handle of an induction heating system according to one embodiment of the present specification;

[0084] Figure 16R shows a spring loaded connection in a first position at a distal end of a handle of an induction heating system according to one embodiment of the present specification;

[0085] Figure 16S Shown in the second position Figure 16R Spring loaded connector;

[0086] Figure 16T A closed loop steam delivery system for use with an endoscope according to one embodiment of the present specification is shown;

[0087] Figure 16U It shows the use Figure 16T A flow chart of the steps involved in one embodiment of a method of providing vapor ablation therapy with a vapor delivery system;

[0088] Figure 16V A closed-loop steam delivery system for use with an endoscope according to another embodiment of the present specification is shown;

[0089] Figure 16W It shows the use Figure 16V A flow chart of the steps involved in one embodiment of a method of providing vapor ablation therapy with a vapor delivery system;

[0090] Figure 16X A closed-loop steam delivery system for use with an endoscope according to yet another embodiment of the present specification is shown;

[0091] Figure 16Y It shows the use Figure 16X A flow chart of the steps involved in one embodiment of a method of providing vapor ablation therapy with a vapor delivery system;

[0092] Fig.17A An exemplary handle mechanism including an RF coil for use with an ablation catheter is shown according to one embodiment;

[0093] Fig. 17B An embodiment of the invention is shown attached to an endoscope. Fig.17A The handle mechanism;

[0094] Fig. 17C Another embodiment of a handle mechanism including an RF coil for use with an ablation catheter is shown;

[0095] Fig.17D An embodiment of the invention is shown attached to an endoscope. Fig. 17CThe handle mechanism;

[0096] Fig.17E Another embodiment of a handle mechanism for use with an ablation catheter is shown;

[0097] Fig.17F shows a close up view of a fastener for securing a handle to an endoscope according to one embodiment;

[0098] Figure 17G shows another close-up view of a fastener for securing a handle to an endoscope according to one embodiment;

[0099] Fig.17H An embodiment of the invention is shown attached to an endoscope. Fig.17E The handle mechanism;

[0100] Fig.18A is a schematic diagram of a steam ablation system using inductive heating according to one embodiment of the present specification;

[0101] Fig.18B shows the behavior of various gases when heated to high temperatures compared to the ideal gas law;

[0102] Fig.19A is a schematic vertical cross-sectional view of an inductive heating compartment according to one embodiment of the present specification;

[0103] Fig.19B is a further detailed display of the various components of the compartment Fig.16A Schematic diagram of an inductive heating compartment;

[0104] Fig.19C yes Fig.19A A horizontal cross-sectional view of an induction heating compartment;

[0105] Fig. 20A A cardiac ablation catheter according to one embodiment of the present specification is shown;

[0106] Fig. 20B Shown by Fig. 20A cardiac ablation performed with a cardiac ablation catheter;

[0107] Fig. 20C It shows the use Fig. 20A A flowchart of the steps involved in one embodiment of a method of using a catheter to ablate cardiac tissue;

[0108] Fig.20D A cardiac ablation catheter according to another embodiment of the present specification is shown;

[0109] Fig.20E A depiction capsule is shown, which has Fig.20D Delineation of the catheter electrodes;

[0110] Fig.20F Shows Fig.20D A cross-sectional view of an intermediate shaft portion of a catheter;

[0111] Figure 20G Shows Fig.20D a cross-sectional view of a distal end portion of a catheter;

[0112] Fig. 20H It shows the use Fig.20D A flowchart of the steps involved in one embodiment of a method of using a catheter to ablate cardiac tissue;

[0113] Fig.20I A cardiac ablation catheter according to another embodiment of the present specification is shown;

[0114] Fig. 20J yes Fig.20I A cross-sectional view of an intermediate shaft portion of a catheter;

[0115] Figure 20K Shown by Fig.20I cardiac ablation performed with a cardiac ablation catheter;

[0116] Figure 20L It shows the use Fig.20I A flowchart of the steps involved in one embodiment of a method of using a catheter to ablate cardiac tissue;

[0117] Fig.21 A steam ablation catheter is shown introduced into the left atrium of a heart via a transseptal approach according to one embodiment of the present specification;

[0118] Fig.22A A cardiac ablation catheter having a first distal attachment is shown according to an embodiment;

[0119] Fig. 22B A cardiac ablation catheter having a second distal attachment is shown according to one embodiment;

[0120] Fig. 22C A cardiac ablation catheter having a third distal attachment is shown according to an embodiment;

[0121] Fig.23 An embodiment of a cardiac ablation catheter according to an embodiment of the present specification is shown, which passes through the left atrium of the heart and enters the pulmonary vein;

[0122] Fig.24 is a flow chart of the steps involved in one embodiment of a cardiac ablation method;

[0123] Fig.25AA side cross-sectional view of one embodiment of a cardiac ablation catheter is shown, wherein the distal attachment includes an inner balloon positioned within an outer balloon;

[0124] Fig.25B According to an embodiment Fig.25A channels in the ducts;

[0125] Fig.25C shows a flow mechanism for a catheter through an inner and outer balloon according to one embodiment;

[0126] Fig.26A Shown are side cross-sectional and perspective views of an inner bladder when the bladder is in an unexpanded state according to one embodiment.

[0127] Fig.26B shows a side cross-sectional view and a perspective view of an inner bladder when the bladder is in an expanded state according to one embodiment;

[0128] Fig. 27 shows a side cross-sectional view and a perspective view of an outer bladder according to one embodiment;

[0129] Fig.28 shows a side view, a side cross-sectional view, and a perspective view of a pressure-resistant Luer lock positioned at the proximal end of a catheter according to one embodiment of the present specification;

[0130] Fig.29A shows endometrial ablation performed in a female uterus using an ablation device according to an embodiment of the present specification;

[0131] Fig.29B is a schematic diagram of a coaxial catheter used in endometrial tissue ablation according to one embodiment of the present specification;

[0132] Fig.29C is a flow chart listing steps involved in a procedure for ablating endometrial tissue using a coaxial ablation catheter according to one embodiment of the present specification;

[0133] Fig.29D is a schematic diagram of a bifurcated coaxial catheter used in endometrial tissue ablation according to one embodiment of the present specification;

[0134] Fig.29E is a flowchart according to an embodiment of the present specification, which lists the use of Fig.29D The method steps include using an ablation catheter to ablate endometrial tissue;

[0135] Fig.29F is a schematic diagram of a bifurcated coaxial catheter with an expandable element for use in endometrial tissue ablation according to one embodiment of the present specification;

[0136] Figure 29GIt is inserted into the patient's uterine cavity for ablation of endometrial tissue. Fig.29F Schematic diagram of the catheter;

[0137] Fig.29H is a flowchart according to an embodiment of the present specification, which lists the use of Fig.20F The method steps include using an ablation catheter to ablate endometrial tissue;

[0138] Fig.29I is a schematic diagram of a bifurcated coaxial catheter used in endometrial tissue ablation according to another embodiment of the present specification;

[0139] Fig.29J is a schematic diagram of a bifurcated coaxial catheter used in endometrial tissue ablation according to yet another embodiment of the present specification;

[0140] Figure 29K is a schematic diagram of a water-cooled catheter used in endometrial tissue ablation according to one embodiment of the present specification;

[0141] Figure 29L is a schematic diagram of a water-cooled catheter for endometrial tissue ablation and positioned in a patient's uterus according to another embodiment of the present specification;

[0142] Fig.29M is a schematic diagram of a water-cooled catheter used in cervical ablation according to one embodiment of the present specification;

[0143] Fig.29N It is located in the patient's cervix. Fig.29M Schematic diagram of the catheter;

[0144] Fig.29O is used Fig.29M A flow chart of the steps involved in performing cervical ablation with a catheter;

[0145] Fig. 30A A flow chart showing a method for ablation of endometrial tissue according to one embodiment of the present specification is shown;

[0146] Fig. 30B A flow chart showing a method for ablation of uterine fibroids according to one embodiment of the present specification is shown;

[0147] Fig.31A is a schematic diagram of a water cooling conduit according to another embodiment of the present specification;

[0148] Fig.31B yes Fig.31A A cross-sectional view of the end of a water-cooling pipe;

[0149] Fig.32AA schematic diagram showing prostate ablation performed on an enlarged prostate in a male urinary system by using a device according to an embodiment of the present specification;

[0150] Fig.32B is a schematic diagram of transurethral prostate ablation performed on an enlarged prostate in a male urinary system using an ablation device according to one embodiment of the present specification;

[0151] Fig.32C is a schematic diagram of transurethral prostate ablation performed on an enlarged prostate in a male urinary system using an ablation device according to another embodiment of the present specification;

[0152] Fig.32D is a flow chart according to one embodiment of the present specification, which lists the steps involved in a transurethral ablation of an enlarged prostate using an ablation catheter;

[0153] Fig.32E is a schematic diagram of transrectal prostate ablation performed on an enlarged prostate in the male urinary system using an ablation device according to one embodiment of the present specification;

[0154] Fig.32F is a schematic diagram of transrectal prostate ablation performed on an enlarged prostate in a male urinary system using a coaxial ablation device with a positioning element according to another embodiment of the present specification;

[0155] Figure 32G yes Fig.32E and 32F A close-up schematic diagram of a catheter and a distal end of a needle tip of an ablation device;

[0156] Fig.32H is a flow chart according to one embodiment of the present specification, which lists the steps involved in a transrectal ablation of an enlarged prostate using an ablation catheter;

[0157] Fig.33A is a schematic diagram of an ablation catheter according to an embodiment of the present specification;

[0158] Fig.33B yes Fig.33A A cross-sectional view of the distal end of an ablation catheter;

[0159] Fig.33C According to the use of the embodiment Fig.33A Schematic diagram of transurethral prostate ablation performed with an ablation catheter;

[0160] Fig.33D is a flow chart of the steps involved in a transurethral ablation procedure for an enlarged prostate according to one embodiment;

[0161] Fig.34Ais a schematic diagram of an ablation catheter according to another embodiment of the present specification;

[0162] Fig.34B yes Fig.34A A cross-sectional view of the distal end of an ablation catheter;

[0163] Fig.34C According to the use of the embodiment Fig.34A Schematic diagram of transurethral prostate ablation performed with an ablation catheter;

[0164] Fig.34D is a flow chart of the steps involved in a transurethral enlarged prostate ablation procedure according to one embodiment.

[0165] Fig.35A is a schematic diagram of one embodiment of a positioning element of an ablation catheter, showing a plurality of thermally conductive elements attached thereto;

[0166] Fig.35B is a schematic diagram of one embodiment of a positioning element of an ablation catheter, showing a plurality of hollow thermally conductive elements attached thereto;

[0167] Fig.36 is a flow chart showing one embodiment of a method of ablating tissue using a needle catheter device;

[0168] Fig.37 is a flow chart showing a method for ablating submucosal tissue using a needle catheter device according to one embodiment of the present specification;

[0169] Fig.38 is a schematic diagram of a deformable needle according to an embodiment of the present specification;

[0170] Fig.39 is a schematic diagram of performing transurethral prostate ablation using an ablation device according to one embodiment of the present specification;

[0171] Fig.40A is a schematic diagram of one embodiment of a positioning element of an ablation catheter with a needle attached to the catheter body;

[0172] Fig.40B is a schematic diagram of another embodiment of a positioning element for an ablation catheter;

[0173] Fig.40C shows a cross section of a distal tip of a catheter according to an embodiment of the present specification;

[0174] Fig.41 One embodiment of a handle mechanism is shown that can be used to deploy and retrieve an ablation needle with variable insertion depths;

[0175] Fig.42Ais a flow chart showing a method for ablation of prostate tissue according to one embodiment of the present specification;

[0176] Fig.42B is a flow chart showing a prostate tissue ablation method according to another embodiment of the present specification;

[0177] Fig.43A is the International Prostate Symptom Score (IPSS) questionnaire; and

[0178] Fig.43B It is the Benign Prostatic Hypertrophy Impact Index Questionnaire (BPHIIQ). DETAILED DESCRIPTION

[0179] In various embodiments, the ablation devices and catheters described herein are used in association with any one or more heating systems described in U.S. patent application Ser. No. 14 / 594,444, entitled “Method and Apparatus for Tissue Ablation,” filed on January 12, 2015 and published on February 7, 2017 as U.S. Patent No. 9,561,068, which is incorporated herein by reference in its entirety.

[0180] "Treat," "treat," and variations thereof, refers to any means of reducing the extent, frequency, or severity of one or more symptoms or signs associated with a condition.

[0181] "Duration" and its variations refer to the time course of treatment as prescribed, i.e., from start to finish, whether or not treatment ends because the condition is resolved or treatment is suspended for any reason. Within the duration of treatment, multiple treatment sessions may be prescribed, during which one or more prescribed stimuli are applied to the subject.

[0182] A "period of time" is the time over which a "dose" of stimulation is applied to a subject as part of a prescribed treatment plan.

[0183] The term "and / or" means one or all of the listed elements or any two or more of the listed elements.

[0184] In the specification and claims of this application, each word "includes", "comprising" and "having" and its various forms are not intended to limit the components to the list associated with the word. The term "includes" and its variations do not have a limiting meaning when appearing in the specification and claims.

[0185] Unless otherwise stated, "a," "an," "the," "one or more," and "at least one" are used interchangeably and mean one or more than one.

[0186] The term "controller" refers to an integrated hardware and software system defined by multiple processing elements, such as integrated circuits, application specific integrated circuits, and / or field programmable arrays, which are in data communication with storage elements (such as random access memory or read-only memory), wherein one or more processing elements are configured to execute program instructions stored in one or more storage elements.

[0187] The term "steam generating system" refers to any or all heaters or inductors described herein that are based on generating steam from water.

[0188] Because any method disclosed herein includes discrete steps, the steps may be performed in any practicable order, and any combination of two or more steps may be performed simultaneously where appropriate.

[0189] As described herein, the numerical range defined by the endpoints includes all values ​​that fall within the range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.). Unless otherwise specified. Otherwise, all numerical values ​​used in this specification and claims to represent components, molecular weights, etc. should be understood to be modified by the term "about" in all cases. Thus, unless otherwise described to the contrary, the numerical parameters described in this specification and claims are approximate values, which can be changed according to the desired performance to be achieved in this specification. At least, and not to limit the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be understood in view of the number of important data described and by rounding.

[0190] Although the numerical ranges and parameters setting forth the broad scope of the specification are approximations, the numerical values ​​set forth in the specific examples should be understood as precisely as possible. However, all numerical values ​​are inherently within the range resulting from the standard deviation found in their respective testing measurements.

[0191] The device and method of the present specification can be used to make the controlled centralized or peripheral ablation of the target tissue to change the depth in a way that can be completely restored by epidermal replantation. In addition, steam can be used to treat / ablate benign and malignant tissue growth, causing destruction, liquefaction and absorption of the ablated tissue. The dosage and mode of treatment can be adjusted based on the tissue type and the required ablation depth. The ablation device can be used not only for arrhythmias, Barrett's esophagus and esophageal atypical hyperplasia, flat colon polyps, gastrointestinal bleeding lesions, endometrial resection, and lung ablation, but also for the treatment of any mucosal, submucosal or peripheral lesions, such as inflammatory lesions, tumors, polyps, and vascular lesions. The ablation device can also be used for the treatment of centralized or peripheral mucosal and submucosal lesions of any hollow organ or hollow body passage in the body. The hollow organ can be one of the gastrointestinal tract, pancreatic bile duct, urogenital tract, respiratory tract or vascular structures (such as blood vessels). The ablation device can be placed in the form of endoscopy, radiation, surgery or direct imaging. In various embodiments, a wireless endoscope or a single fiber endoscope may be incorporated as part of the device. In another embodiment, magnetic or stereotactic navigation may be used to navigate the catheter to the desired location. Radiopaque or acoustically transparent materials may be incorporated into the catheter body for radiolocalization. Iron or ferromagnetic materials may be incorporated into the catheter to facilitate magnetic navigation.

[0192] An ablative agent, such as steam, heated gas, or cryogen (such as but not limited to liquid nitrogen), is inexpensive and easy to use, and is directed to the tissue via an injection port, maintained at a fixed and constant distance for ablation. This allows the ablative agent to be evenly distributed over the target tissue. The flow of the ablative agent is controlled by a microprocessor according to a predetermined method based on the characteristics of the tissue to be ablated, the desired ablation depth, and the distance of the port from the tissue. The microprocessor can use temperature, pressure, or other sensor data to control the flow of the ablative agent. In addition, one or more suction ports are configured to aspirate the ablative agent from the vicinity of the target tissue. The target site can be treated by continuous injection of the ablative agent or by a cycle of injection and removal of the ablative agent (as determined and controlled by the microprocessor).

[0193] It should be understood that the devices and embodiments described herein are implemented in conjunction with a controller including a microprocessor that executes control instructions. The controller can be in the form of any computing device, including a desktop computer, a laptop computer, and a mobile device, and can communicate control signals to the ablation device in a wired or wireless form.

[0194] The present invention relates to multiple embodiments. The following content is provided to enable those skilled in the art to implement the present invention. The language used in this specification should not be understood as a general negation of any specific embodiment or to limit the claims beyond the terms used herein. The general principles defined herein can be applied to other embodiments and applications without departing from the spirit and scope of the present invention. In addition, the terms and expressions used are for the purpose of describing exemplary embodiments and should not be considered as limiting. Thus, the present invention should be consistent with the widest range of many replacement examples, modifications, and equivalent examples consistent with the principles and features. For the purpose of clarity, the details of the technical materials known in the technical field related to the present invention do not need to be described in detail so as not to unnecessarily affect the present invention.

[0195] It should be noted that any feature or component described in connection with a specific embodiment may be used and implemented in any other embodiment, unless expressly described otherwise.

[0196] Figure 1A An ablation device according to an embodiment of the present specification is shown. The ablation device includes a catheter 10 having a distally centered or positioned attachment, which is a fillable balloon 11. The catheter 10 is made of or covered with an insulating material to prevent ablative energy from escaping from the catheter body. The ablation device includes one or more injection ports 12 for injecting an ablative agent, and one or more suction ports 13 for removing the ablative agent. In one embodiment, the injection port 12 and the suction port 13 are the same. In one embodiment, the injection port 12 can guide the ablative agent at different angles. The ablative agent is stored in a reservoir 14 connected to the catheter 10. The delivery of the ablative agent is controlled by a microprocessor 15, and the initialization of the treatment is controlled by a treating physician using an input device (e.g., a foot pedal 16). In other embodiments, the input device can be a voice recognition system (which responds to commands such as "start", "more", "less", etc.), a mouse, a switch, a foot pad, or any other input device known to those skilled in the art. In one embodiment, microprocessor 15 converts a signal from an input device (e.g., pressure placed on a foot pedal or a voice command providing "more" or "less" ablative agent) into a control signal for determining the dispensing of more or less ablative agent. Optional sensor 17 monitors changes in or near the ablated tissue to direct the flow of ablative agent. In one embodiment, optional sensor 17 also includes a temperature sensor. Optional infrared, electromagnetic, acoustic, or radio frequency energy transmitters and sensors 18 measure the size of the hollow organ.

[0197] In one embodiment, a user interface including microprocessor 15 allows the physician to define devices, organs and conditions, which in turn form default settings for temperature, circulation, volume (sound) and standard RF settings. In one embodiment, these default settings can be further modified by the physician. The user interface also includes standard displays of all key variables and warnings for values ​​exceeding or falling below certain levels.

[0198] The ablation device also includes safety mechanisms to protect the user from burns while operating the catheter, including thermal insulation, and optionally, cooling air puffs, cooling water flushes, and warnings / sounds to indicate the start and stop of treatment.

[0199] In one embodiment, the fillable balloon has a diameter of 1 mm to 10 cm. In one embodiment, the fillable balloon is separated from the port by a distance of 1 mm to 10 cm. In one embodiment, the size of the port opening is 1 μm to 1 cm. It should be understood that the fillable balloon is used to fix the device and is therefore configured not to contact the ablation area. The fillable balloon can be of any shape that contacts the hollow organ at 3 or more points. It should be understood by those skilled in the art that using triangulation, the distance of the catheter from the lesion can be calculated. Alternatively, an infrared, electromagnetic, acoustic or radio frequency energy transmitter and sensor 18 can measure the size of the hollow organ. Infrared, electromagnetic, acoustic or radio frequency energy is emitted from the transmitter 18 and reflected back from the tissue to the detector in the transmitter 18. The reflected data can be used to determine the size of the hollow cavity. It should be understood that the transmitter and sensor 18 can be incorporated into a single transceiver that can transmit energy and detect reflected energy.

[0200] Figure 1B Another embodiment of a catheter 110 is shown for use in Figure 1A The catheter 110 includes an inlet port 119 and an insufflation port 120 at its proximal end. The ablative agent is introduced into the catheter 110 via the inlet port 119 and delivered to the target area through at least one delivery port 112 at the distal end of the catheter 110. Air is introduced at the insufflation port 120 to fill at least one positioning element 111 at the distal end of the catheter. In one embodiment, the at least one positioning element 111 is a balloon.

[0201] Figure 2A A longitudinal cross section of an ablation device is shown, illustrating the distribution of injection ports. Figure 2B FIG. 1 shows a cross section of the distribution of injection ports on an ablation device according to an embodiment of the present specification. The longitudinal and cross-sectional views of the catheter 10 are shown in FIG. Figure 2A and 2BAs shown, one arrangement of injection ports 12 is shown to produce a uniform distribution of ablative agent 21 to provide a circumferential ablation zone in hollow organ 20 . Figure 2C FIG. 4 shows a cross section of the injection port distribution on an ablation device according to another embodiment of the present specification. Figure 2C The arrangement of the injection ports 12 shown produces a focused distribution of the ablative agent 21 and a focused ablation zone in the hollow organ 20 .

[0202] For all embodiments described herein, it should be understood that the size of the ports, the number of ports, and the distance between the ports are determined by the required ablation dose, the pressure that the hollow organ can withstand, the size of the hollow organ measured by the distance of the surface from the port, the length of the tissue to be ablated (which is basically the surface area to be ablated), the characteristics of the tissue to be ablated, and the required ablation depth. In one embodiment, there is at least one port opening having a diameter of 1 μm to 1 cm. In another embodiment, there are two or more port openings having a diameter of 1 μm to 1 cm and are equally spaced around the periphery of the device. In some embodiments, the port optionally has a valve for controlling the release of the ablative agent. In various embodiments, the valve is regulated by pressure, temperature, or both.

[0203] Figure 2D Another embodiment of an ablation device is shown. A steam ablation catheter comprises an insulating catheter 21 having one or more positioning attachments 22 of known length 23. The steam ablation catheter has one or more steam injection ports 25. The length of the steam ablation catheter 21 having the injection port 25 is determined by the length or area of ​​the tissue to be ablated. Steam 29 is delivered through the steam injection port 25. The catheter 21 is preferably positioned at the center of the positioning attachment 22, and the injection ports 25 are arranged circumferentially for circumferential ablation and delivery of steam. In another embodiment, the catheter 21 may be positioned toward the periphery of the positioning attachment 22 and the injection ports 25 may be arranged non-circumferentially, preferably in a straight line on one side, for concentrated ablation and delivery of steam. The positioning attachment 22 is one of a fillable balloon, a wire mesh disc with or without an insulating film covering the disc, a conical attachment, an annular attachment, or any attachment designed to match a desired hollow body organ or hollow body passage, as described in detail below. Optional infrared, electromagnetic, acoustic, or radio frequency energy transmitters and sensors 28 are incorporated to measure the dimensions of the hollow organ.

[0204] The steam ablation catheter may also include an optional coaxial sheet 27 that constrains the positioning attachment 22 in a manner comparable to a metal coronary stent. In one embodiment, the sheet is made of a memory metal or memory material having an extruded straight form and a non-extruded form in the shape of the positioning attachment. Alternatively, the channel of the endoscope can perform the function of constraining the positioning attachment 22, for example by acting as a constraining sheath. An optional sensor 26 is arranged on the catheter to measure changes related to steam delivery or ablation. The sensor is one of a temperature, pressure, light or chemical sensor.

[0205] Optionally, one or more infrared, electromagnetic, acoustic or radio frequency energy transmitters and sensors 28 can measure the size of the hollow organ. Infrared, electromagnetic, acoustic or radio frequency energy is emitted from the transmitter 28 and reflected back from the tissue to the detector in the transmitter 28. The reflected data can be used to determine the size of the hollow cavity. Measurements are performed at one or more points to obtain an accurate estimate of the size of the hollow organ. The data can also be used to form a topographical representation of the hollow organ. Additional data from diagnostic tests can be used to verify or add to the data from the above measurements.

[0206] Figure 2E FIG. 2 shows a catheter 21 of an ablation device according to another embodiment of the present specification. The catheter 21 is similar to the catheter 21 of FIG. Figure 2D The catheter, however Figure 2E The catheter 21 further includes at least one port 19 for delivering a conductive medium 31. In one embodiment, the conductive medium 31 is sprayed into the hollow tissue or organ prior to introducing the ablative agent 29. Once the tissue has been filled to an appropriate level with the conductive medium 31, the ablative agent 29 is then delivered into the tissue filled with the conductive medium 31. The conductive medium 31 is used to evenly distribute the ablative agent 29, achieving more consistent and effective ablation of the target tissue.

[0207] Figure 2F FIG. 2 shows a catheter 21 of an ablation device according to another embodiment of the present specification. The catheter 21 is similar to the catheter 21 of FIG. Figure 2E As stated, however Figure 2F The catheter 21 further comprises at least one port 30 for aspiration of the natural contents of the hollow tissue or organ. In one embodiment, the natural contents of the hollow tissue or organ are removed before the conductive medium 31 or the ablative agent 29 is introduced.

[0208] In another embodiment, if Figure 2E As shown, where the catheter includes at least one port 25 for delivering an ablative agent and at least one other port 19 for delivering a conductive medium, the ablative agent delivery port 25 can be used to remove the natural contents of the hollow tissue or organ via suction. In another embodiment, as Figure 2EAs shown, the catheter includes at least one port 25 for delivering an ablative agent and at least one other port 19 for delivering a conductive medium, and the conductive medium delivery port 19 can be used to remove the natural contents of the hollow tissue or organ via suction. In another embodiment, as Figure 2D As shown, a conductive medium may be delivered and the native contents of the hollow tissue or organ may be removed via suction using ablative agent delivery port 25. In various embodiments, after ablation of the target tissue(s), the remaining hollow tissue or organ contents are removed via suction using one or more ports as described above.

[0209] In various embodiments, for Figure 2A –2F catheter, the ablative agent can be steam, liquid nitrogen, or any other suitable ablative agent.

[0210] Figure 2G 2 is a flow chart according to one embodiment of the present specification, which lists the steps involved in the process of ablation of a hollow tissue or organ using an ablation device. In step 202, an endoscope is inserted into a patient. In step 204, an ablation device including a catheter according to one embodiment of the present specification is advanced through the working channel of the endoscope and reaches the target tissue. In step 206, the distal end or tip of the catheter is inserted into the target hollow tissue or organ. Subsequently, in step 208, suction is applied at the proximal end of the catheter to remove the natural contents of the hollow tissue or organ. In step 210, a conductive medium is then injected into the hollow tissue or organ via at least one port on the distal end of the catheter. In step 212, an ablative agent is delivered to the conductive medium for ablating the target tissue. In step 214, the residual tissue contents (including the conductive medium and the ablative agent) are removed via suction using the catheter. In another embodiment, step 214 is optional, and the residual hollow tissue or organ contents are reabsorbed by the body. In another embodiment, removal of the natural contents of the hollow tissue or organ at step 208 is optional, and the process proceeds directly from accessing the target tissue through the catheter at step 206 to ejecting the conductive medium at step 210. Alternatively, in some embodiments, the natural contents of the hollow organ may be used as the conductive medium.

[0211] Figure 2HAn ablation device 220 in the form of a catheter 221 extending from a conventional handle 222 is shown in accordance with an embodiment of the present specification. The catheter 221 is of the type described above and extends from and is attached to the handle 222. In one embodiment, the catheter 221 is thermally insulated to protect the user from being burned by hot steam that heats the catheter. In one embodiment, the catheter includes a material that ensures that the external temperature of the catheter remains below 60°C during use. The handle 222 includes a pressure-resistant port at the point of attachment to the catheter 221. The handle 222 also includes a flow channel through which steam is directed to the catheter 221.

[0212] In one embodiment, the snare handle 222 includes a single attachment port 223 for connection of steam flow and RF feed. In another embodiment (not shown), the snare handle includes two separate attachment ports for connection of steam flow and RF feed. The attachment port 223 is connected to the steam supply cable interface via a pressure-resistant connector. In one embodiment, the connector is a luer lock type. In one embodiment, the catheter 221 is a dual lumen catheter. The first lumen is used to deliver steam to the ablation site. In one embodiment, the steam is released through a small port 224 located near the distal end of the catheter 221. The distal end of the catheter 221 is designed so that it can penetrate tissue to deliver steam to the desired depth and position in the target tissue. In one embodiment, the distal end of the catheter 221 is a pointed cone. The second lumen houses an electrode for RF ablation. In one embodiment, the delivery of steam or RF waves is achieved by using a microprocessor. In another embodiment, the user can release steam or subject the target tissue to RF waves by using an actuator (not shown) of the handle 222. In one embodiment, the catheter has varying or different insulation along its length. In one embodiment, ablation device 220 includes a mechanism where the amount of steam to be delivered is determined using a snare for grasping the tissue to be ablated and sizing the tissue within the snare.

[0213] Fig.2I A cross section of an ablation device 227 in the form of a catheter 231 extending from a conventional handle 232 is shown with a pre-attached cable 235 according to another embodiment of the present specification. The cable 235 is directly attached to the vapor delivery system, eliminating an interface between the system and the ablation device and thereby reducing the possibility of system failure due to disconnection. In this embodiment, the handle 232 includes a separate accessory port (not shown) for RF or electrical feed.

[0214] Figure 2JAn ablation device 229 in the form of a catheter 241 extending from a conventional esophageal probe 226 is shown according to an embodiment of the present specification. In one embodiment, the catheter 241 is thermally insulated and receives steam from a flow channel contained in the probe 226. The catheter 241 includes a plurality of small ports 244 for delivering steam to the target tissue. The delivery of steam is controlled by a microprocessor. In one embodiment, the catheter 241 also includes two fillable balloons 228, one balloon at its distal end beyond the last steam port 244, and one balloon at its proximal end, near the location where the catheter 241 is attached to the probe 226. All steam ports are positioned between the two balloons. Once the device 229 is inserted into the esophagus, the balloons 228 are filled to keep the catheter 241 positioned in the desired treatment area and contain steam in the area. In one embodiment, the balloons must be separated from the ablation area by a distance greater than 0 mm, preferably 1 mm, and ideally 1 cm. In one embodiment, the diameter of each balloon when filled is in the range of 10 to 100 mm, preferably 15-40 mm, but it should be understood by those skilled in the art that the exact size depends on the size of the patient's esophagus.

[0215] In one embodiment, the catheter 241 attached to the esophageal probe 226 is a dual lumen catheter. The first lumen is used to deliver steam to the ablation site as described above. The second lumen houses the electrodes for RF ablation.

[0216] In various embodiments, the ablation therapy provided by the steam ablation system of the present specification is used to achieve the following common therapeutic endpoints: maintaining the tissue temperature at 45°C to 100°C for a period of time greater than 1 second; maintaining the tissue temperature at 100°C or less to allow coagulation of intracellular proteins without causing carbonization of intracellular sugars; applying a pressure to the tissue to be ablated that is equal to or less than 125% of the pre-treatment pressure of the tissue; and applying a pressure to the tissue to be ablated that is less than the patient's mean arterial pressure so as not to impede perfusion of the tissue.

[0217] Figure 3Detailed description is a flow chart of the steps involved in one embodiment of a method for tissue ablation. In a first step 301, a body cavity, cavity or space in which the tissue to be ablated is located is partially or completely closed or sealed. This closure or sealing can be achieved by passing a catheter (e.g., in the case of ablation in the patient's uterus) or by a balloon (e.g., when ablation is performed in the patient's digestive tract). In the next step 302, steam is delivered to heat the cavity, which in turn causes the air in the cavity to expand. The expanded air serves to increase the pressure in the cavity and exert a positive pressure on the cavity wall. This in turn causes the body cavity to expand. In the next step 303, a portion of the hot air in the body cavity is allowed to escape outside the cavity. Next, in step 304, the delivery of steam is stopped and the air in the cavity is allowed to cool. This causes the air in the cavity to contract and reduce the pressure in the cavity. This in turn allows the cavity around the catheter or balloon to contract and collapse, thereby increasing the level of closure or sealing and forming a seal. When the body cavity is sealed around the inserted catheter or balloon, it does not allow the expelled air to re-enter the cavity. This creates a negative pressure in the cavity and the negative pressure is applied to the cavity wall. The negative pressure can in turn increase blood flow to the cavity wall, cooling the cavity wall. In addition, allowing the heated air to escape from the cavity can allow the pressure on the cavity wall to be released during the cessation of ablative flow between ablation cycles, thereby allowing capillary blood flow and cooling the ablation area.

[0218] Figure 4A A multi-lumen ablation catheter 400 according to an embodiment of the present specification is shown. The catheter 400 includes an elongated body 405 having a proximal end and a distal end. The catheter 400 includes at least one positioning element near its distal end. In various embodiments, the positioning element is a balloon. In some embodiments, the catheter includes more than one positioning element.

[0219] exist Figure 4A In the illustrated embodiment, the catheter 400 includes two positioning balloons 410, 412 near its distal end, and a plurality of injection ports 415 are located on the body 405 between the two balloons 410, 412. A fluid delivery port 427 and an aspiration port 432 are located at the distal end of the body 405. The body 405 includes a first lumen 420 in fluid communication with the plurality of injection ports 415, a second lumen 425 in fluid communication with the fluid delivery port 427, and a third lumen 430 in fluid communication with the aspiration port 432. The first, second, and third lumens 420, 425, 430 are passed along the length of the body 405 through a handle 435 at the proximal end and to the distal end. An ablative agent 421 is introduced into the first lumen 420 at the ablative agent input port 401 at the proximal end of the catheter 400 and exits through the injection port 415 for ablation. In one embodiment, the ablative agent 421 is vapor.

[0220] Fluid 426 is introduced into the second lumen 425 at the fluid input port 402 at the proximal end of the catheter 400 and exits through the fluid delivery port 427. In one embodiment, the fluid 426 is a coolant. In one embodiment, the coolant is water and is in the temperature range of 0°C to 60°C. A pump is used to apply negative pressure to the third lumen 430 at the suction input port 403 at the proximal end of the catheter 400 so that the fluid delivered from the fluid delivery port 427 and the injection port 415, respectively, is suctioned via the suction port 432. In various embodiments, the fluid delivery port 427 and the suction port 432 can be located at various positions along the length of the catheter 400, away from the positioning balloon 412 or close to the positioning balloon 410.

[0221] Figure 4B The use of the embodiment according to this specification is shown Figure 4A The basic process steps of the ablation catheter 400 are now shown. Figure 4A and 4B At step 462, the body 405 of the ablation catheter 400 is inserted into the organ to be ablated. For example, to perform ablation in a patient's Barrett's esophagus, the catheter is inserted into the Barrett's esophagus via the patient's esophagus.

[0222] At step 464, the positioning elements or capsules 410, 412 are deployed so that the plurality of injection ports 415 are proximal to the tissue to be ablated, while the fluid delivery port 427 and the suction port 432 are positioned at a location remote from the ablation area. Thereafter, at step 466, an ablative agent (e.g., vapor) is delivered to the target tissue to be ablated via the injection port 415 through the first lumen, while at the same time, the fluid is delivered to the target tissue to be ablated via the fluid delivery port 427 through the second lumen at a location remote from the ablated tissue, such that the delivery of the fluid does not significantly interfere with the delivery of the ablative agent. According to some embodiments, the fluid is delivered at a temperature of 0 to 60°C. Also, at the same time, the delivered fluid is aspirated from a location remote from the ablated tissue through the suction port 432 and the third lumen 430, such that the aspiration of the fluid does not cause the aspiration of the delivered ablative agent. According to an alternative embodiment, at step 468, the fluid is alternately delivered and aspirated through the fluid delivery port 427 and the second lumen 425, respectively. In another embodiment, at step 469, the fluid is allowed to passively exit through the suction port 432.

[0223] Figure 5A is a first diagram showing a process of ablating tissue according to an embodiment. Figure 5AAs shown, an ablative agent (e.g., steam) is delivered to the target tissue over a first time period 570, whereby the temperature of the target tissue is raised to a first temperature 576. The temperature of the target tissue is maintained at the first temperature 576 over the first time period 570. After the first time period 570 is completed, the delivery of steam is turned off and the target tissue temperature is allowed to cool to a base temperature 575. After a second time period 572, steam continues to be delivered to the target tissue and the cycle of the ablation process is repeated. Figure 5B FIG. 4 is a second diagram showing a process of ablating tissue according to another embodiment. Figure 5B As shown, an ablative agent (e.g., steam) is delivered to the target tissue and passes through a third time period 580, whereby the temperature of the target tissue is raised to a second temperature 586. The temperature of the target tissue is maintained at the second temperature 586 and passes through the third time period 580. After the third time period 580 is completed, the delivery of steam is turned off and the target tissue temperature is allowed to cool to a base temperature 585. After the fourth time period 582, steam continues to be delivered to the target tissue and the cycle of the ablation process is repeated. In various embodiments, the first and second time periods 570, 572 may be equal or unequal. Similarly, in various embodiments, the third and fourth time periods 580, 582 may be equal or unequal. In other embodiments, the first and third time periods 570 and 580 are not equal, and the second and fourth time periods 572 and 582 are also not equal.

[0224] In various embodiments, the first and fourth time periods 570, 580 are 1 to 180 seconds, and the second and fourth time periods 572, 582 are 1 to 1800 seconds. Also, in various embodiments, the base temperatures 575, 585 are 37 to 45°C, and the first and second temperatures 576, 586 are 60 to 100°C.

[0225] Figure 5C It shows the Figure 5A and 5B Flowchart of multiple steps related to an ablation procedure of the present invention. At step 592, the ablation catheter is inserted into the organ so that the steam delivery port is positioned proximate to the target tissue for ablation. At step 594, steam is delivered to the target tissue and a heating period of 1 to 180 seconds is passed, whereby the target tissue temperature is increased in the range of 60 to 100° C. At step 596, the steam delivery is turned off and a cooling period of 1 to 1800 seconds is passed, whereby the target tissue temperature is reduced to the range of 37 to 45° C. After the cooling period is completed, steps 592 and 594 are repeated.

[0226] Fig. 6A FIG. 1 is a flow chart showing a method for ablating body tissue according to one embodiment of the present specification. Fig. 6A, a first step 631 includes inserting an ablation catheter into a body cavity such that the catheter's steam delivery port is positioned proximate to the target tissue. Next, at step 632, steam is delivered for a period of 1-180 seconds. Thereafter, at step 633, steam delivery is turned off for a period of 1-1800 seconds. At step 634, steam is then delivered again for a second period of 1-180 seconds.

[0227] Figure 6B FIG. 2 is a flow chart showing a method for ablating body tissue according to another embodiment of the present specification. Figure 6B , a first step 641 includes inserting an ablation catheter into a body cavity such that a steam delivery port of the catheter is positioned proximate to the target tissue. Next, at step 642, steam is delivered for a period of time sufficient to raise the temperature of the target tissue to a temperature in the range of 60°C to 100°C. Thereafter, at step 643, steam delivery is turned off for a period of time sufficient to allow the target tissue to cool to a temperature in the range of 37°C to 45°C. At step 644, steam is then delivered again for a second period of time sufficient to raise the temperature of the target tissue to a temperature in the range of 60°C to 100°C.

[0228] Figure 6C FIG. 1 is a flow chart showing a method for ablating body tissue according to another embodiment of the present specification. Figure 6C , a first step 651 comprises inserting an ablation catheter having a plurality of lumens into a body cavity, wherein the catheter comprises at least one steam delivery port in fluid communication with a first lumen of the plurality of catheter lumens, such that the at least one delivery port is positioned proximate to the tissue to be ablated. In step 652, steam is delivered to the tissue to be ablated through the first lumen and the at least one steam delivery port, while simultaneously a fluid in a temperature range of 0 to 60° C. is delivered through a second lumen of the plurality of lumens and through a cooling fluid delivery port of the catheter to a location remote from the tissue being ablated. Optionally, in step 653, fluid is simultaneously aspirated from a location remote from the tissue being ablated through a fluid aspiration port of the catheter and a third lumen of the plurality of lumens. Further, optionally, as shown in step 654, fluid is alternately delivered and aspirated through the cooling fluid delivery port and the second lumen.

[0229] Fig. 7A is a view of a water cooling conduit 700 according to an embodiment of the present specification, and Figure 7B yes Fig. 7A715. The catheter 700 includes an elongated body 705 having a proximal end and a distal end. The distal end includes a plurality of injection ports 715 for delivering an ablative agent 716 (e.g., steam for tissue ablation). A sheath 710 including cooling channels extends along the body 705 of the catheter 700. In some embodiments, the sheath 710 extends along the catheter body 705 to a point distal to or proximal to the port 715. In these embodiments, the sheath 710 is positioned so that it does not cover the port 715, allowing the ablative agent 716 to exit the catheter 700 through the port 715, as shown. Figure 7B As shown. In other embodiments, the sheath extends along the catheter body to a point near the port. During use, water 720 from a water source 722 circulates through the sheath 710 to cool the catheter 700. The water 710 for cooling is then supplied to the compartment 721, where it is heated and converted into steam 716 to be transported through the elongated body 705 and through the injection port 715. The steam 716 for ablation and the water 720 for cooling are supplied to the catheter 700 at the proximal end of the catheter 700. Arrow 723 shows the path of the water 710 passing through the sheath and entering the compartment 721. Arrow 724 shows the path of the steam 716 passing through the elongated body 705 and leaving the injection port 715.

[0230] Fig. 8A An ablation catheter 805 according to an embodiment of the present specification is shown. Figure 8B 805. The elongated body or shaft 807 has a distal end, a proximal end, and includes an outer lumen 809 and a coaxial inner lumen 811. According to one aspect, a coolant 813 (such as, but not limited to, air, water, or saline) passes from the proximal end of the body or shaft 807 and enters the outer lumen 809 and is discharged through the distal end of the body or shaft 807. Similarly, steam 815 passes from the proximal end of the body or shaft 807 and enters the inner lumen 811 to flow out of the distal end of the body or shaft 807, while the body or shaft 807 remains cooled by the circulating coolant 813.

[0231] Fig. 9A An ablation catheter 905 according to an embodiment of the present specification is shown. Fig. 9B905. The elongated body or shaft 907 has a distal end, a proximal end, and includes first and second outer lumens 909a, 909b and a coaxial inner lumen 911. According to one aspect, a coolant 913 (such as, but not limited to, air, water, or saline) passes from the proximal end of the body or shaft 907 and enters the first outer lumen 909a, and after having circulated through the body or shaft 907, is discharged through the second outer lumen 909b also at the proximal end of the body or shaft 907. Steam 915 passes from the proximal end of the body or shaft 907 and enters the inner lumen 911 to flow out of the distal end of the body or shaft 907, while the body or shaft 907 remains cooled by the circulating coolant 913. In some embodiments, where the coolant 913 is air, the air can be released or discharged through a handle attached at the proximal end of the body or shaft 907, thereby cooling the handle. In some embodiments, where the coolant 913 is water, water enters the shaft 907 through the first outer lumen 909a and is supplied through the second outer lumen 909b to a heating compartment enclosed in a handle attached to the body or proximal end of the shaft 907. The water supplied to the heating compartment is converted into steam 915, which then enters the inner lumen 911.

[0232] Fig. 10A According to the ablation catheter 1005 of the embodiment of this specification, Fig. 10B 1 is a cross-sectional view of an elongated body or shaft 1007 of a catheter 1005. The elongated body or shaft 1007 has a distal end, a proximal end, and includes first and second outer lumens 1009a, 1009b and a coaxial inner lumen 1011. At least one balloon 1025 is attached to the distal end of the body or shaft 1007 and is in fluid communication with the first and second outer lumens 1009a, 1009b. In some embodiments, the elongated body or shaft 1007 optionally includes one or more additional outer lumens 1027 ( Fig. 10B) to serve as ancillary passages for various sensors. According to one aspect, coolant 1013 (preferably air) passes from the proximal end of the body or shaft 1007 and enters the first outer chamber 1009a and is discharged through the second outer chamber 1009b, which is also at the proximal end of the body or shaft 1007, after the bladder 1025 has been filled to the desired pressure while maintaining the air circulation flow in the body or shaft 1007 to maintain the temperature of the shaft below 60°C (and preferably below 40°C). The desired pressure in the bladder 1025 is maintained by a pressure valve (or e-valve controlled by a microcontroller) located at the proximal end of the second outer chamber 1009b, where the pressure valve maintains the air flow and opens when the desired pressure reaches the rated value. Similarly, steam 1015 passes from the proximal end of body or shaft 1007 and enters lumen 1011 to flow out from the distal end of body or shaft 1007, while body or shaft 1007 remains cooled by circulating coolant 1013. It should be understood that in some embodiments, lumen 1011 is in fluid communication with another freely movable bladder positioned in bladder 1025.

[0233] Thus, according to one aspect, a coolant (e.g., water) is circulated in the outer cavity of the elongated body and then supplied to the heating compartment for conversion into steam, as described with reference to Fig. 9A , 9B According to another aspect, a coolant (e.g., air) is circulated back and forth in the bladder through the outer cavity of the elongated body to cool the elongated body or shaft, as shown in reference Fig. 10A , 10B described.

[0234] See now Figure 8B , 9B 10B, according to one aspect of the present specification, the inner layer 830, 930, 1030 of the catheter shaft 807, 907, 1007 is thicker than the outer layer 832, 932, 1032 to prevent heating losses or minimize energy transfer from the inside to the outside of the catheter. This is different from the prior art cooling shaft catheter, which aims to maximize the transfer of cold temperature from the inside of the catheter to the outside of the catheter.

[0235] Fig.11 An ablation catheter 1120 is shown according to one embodiment of the present specification. The catheter 1120 includes an elongated body 1121 having a proximal end and a distal end. In one embodiment, the catheter body 1121 includes an inner lumen 1122, a first outer lumen 1123a, and a second outer lumen 1123b. The inner lumen 1122 is separated from the outer lumens 1123a, 1123b by a semi-permeable thermal wall 1124, which allows a portion of the thermal energy to pass from the inner lumen 1122 to the outer lumens 1123a, 1123b. The catheter also includes at least one positioning element or balloon at its distal end. Fig.11In the illustrated embodiment, the catheter 1120 includes two positioning balloons 1125, 1126 at its distal end, between which a plurality of delivery ports 1127 are located on the catheter body 1121. The delivery ports 1127 are in fluid communication with the lumen 1122. An ablative agent 1128 is introduced into the lumen 1122 at the proximal end of the catheter 1120 and exits through the delivery ports 1127 and enters an organ (e.g., esophagus) for ablation. In one embodiment, the ablative agent 1128 is steam. A coolant (e.g., air 1129) is introduced into the first outer lumen 1123a at the proximal end of the catheter 1120, and travels through the filling port 1130a and enters the balloons 1125, 1126 so that the balloons 1125, 1126 are filled, and thereafter exits the balloons 1125, 1126 via the exit port 1130b and enters the second outer lumen 1123b, and finally exits at the proximal end of the catheter, allowing the air 1129 to circulate through the length of the catheter 1120 and through one or more of the balloons 1125, 1126.

[0236] Fig.12 1 shows a connection between a syringe 1220 and a catheter 1210 according to one embodiment. Fig.12 As shown, the proximal end of the catheter 1210 is configured to receive the distal end of the connecting component 1215 so as to form a fluid seal when the distal end of the connecting component 1215 is inserted into the proximal end of the catheter 1210. The syringe 1220 is coupled to the proximal end of the connecting component 1215 to supply water to the catheter 1210 through the connecting component 1215 coupled to the catheter 1210. In various embodiments, a wireless radio frequency identification component 1225 is included at the proximal end of the catheter 1210 to communicate a successful fluid connection between the catheter 1210 and the syringe 1220.

[0237] Fig.13A A connection for coupling a heating compartment to a water source (eg, a syringe pump) is shown according to another embodiment. Fig. 13B The heating coil and ferromagnetic core in the heating compartment are shown. Fig.13A and 13B, the proximal end of the heating compartment 1310 is configured to receive the distal end of the connecting component 1315. The distal end of the connecting component 1315 includes an O-ring 1316 to form a tight fluid seal when the distal end of the connecting component 1315 is inserted into the proximal end of the heating compartment 1310. The connecting component 1315 has an inlet 1320 at its proximal end, which is connected to a syringe pump, such as for supplying water. The heating compartment 1310 includes a coil 1340 wound around a ferromagnetic core 1345. A wire 1330 is attached to the coil 1340 for providing wireless radio frequency (RF) energy to the coil 1340. A wire 1335 is attached to a generator to supply electrical energy. According to one embodiment, when the distal end of the connecting member 1315 is inserted into the proximal end of the heating compartment 1310, the electrical contact 1332 of the wire 1330 is coupled to the electrical contact 1337 of the wire 1335, thereby forming an electrical connection. Fig. 13C A perspective assembly view of the heating compartment 1310 is shown in fluid connection with the connection member 1315. In various embodiments, the fluid connection is configured to withstand a fluid pressure of 5 to 500 psi.

[0238] Fig.13D A cross-sectional view of a heating compartment 1310 is shown, which includes a channel for passing water formed between a non-thermoplastic material and a ferromagnetic core 1345. A coil 1340 is wound around the ferromagnetic core 1345. The heating compartment 1310 includes an outlet 1350 at its distal end for delivering steam and an inlet 1355 at its proximal end for receiving water. Also shown is a conductor ( Fig.13A 1330) and the electrical contact portion 1332 corresponding to the wire ( Fig.13A When the distal end of the connection member 1315 is inserted into the proximal end of the heating compartment 1310 to form a fluid connection and an electrical connection, the connection of the electrical contacts 1332 and 1337 realizes the electrical connection between the coil 1340 and the generator and provides a fail-safe protection, because an incomplete fluid connection will cause a problem of no electrical connection and inability to start induction heating.

[0239] Fig.14A and 14BA spring loaded mechanism 1405 is shown on the heating compartment 1410. The proximal end of the heating compartment 1410 is configured to receive the distal end of the connecting component 1415. The distal end of the connecting component 1415 includes an O-ring 1416 to form a fluid seal when the distal end of the connecting component 1415 is inserted into the proximal end of the heating compartment 1410. The spring loaded mechanism 1405, when pressed, allows the distal end of the connecting component 1415 to be easily inserted into the proximal end of the heating compartment 1410 to form a fluid connection. When released, the spring loaded mechanism 1405 further secures the fluid connection. Fig.14A In the embodiment, the proximal end of the connecting component 1415 includes a syringe pump 1420 to supply water. Fig. 14B A water inlet port 1430 is shown at the proximal end of the connecting member 1415 for supplying water.

[0240] In various embodiments, the connector described herein comprises thermoplastics including ABS, acetal, nylon (polyamide) and polyetheretherketone (PEEK), and fluoropolymers including polyvinylidene fluoride (PVDF). In various embodiments, the O-ring comprises fluorocarbon (FKM) or silicone.

[0241] Fig.15A The use of induction heating to heat compartment 1505 is shown. When alternating current 1502 passes through coil 1507 in compartment 1505, coil 1507 forms a magnetic field 1509. The magnetic flux lines of magnetic field 1509 cut through the air around coil 1507. When compartment 1505 includes ferrous material (such as iron, stainless steel, or copper), due to the presence of alternating current 1502 and magnetic field 1509 having magnetic flux lines 1510, currents referred to as eddy currents 1515 are induced in compartment 1505. Eddy currents 1515 cause compartment 1505 to be locally heated. When compartment 1505 is filled with a fluid (such as water), heat is transferred from the compartment to the fluid inside, achieving the described fluid vaporization. Fig.15A In the illustrated embodiment, coil 1507 is wound four turns around compartment 1505 and is spaced a distance from compartment 1505 to aid in visualization. Fig.15AThe design of the compartment and coil in the embodiment only shows one possible embodiment and is not restrictive. It should be understood by those skilled in the art that many different design configurations for the compartment and coil are also possible. In various embodiments, the coil includes at least one turn around the compartment and is wound around the compartment so that the coil is in physical contact with the compartment. In other embodiments, the coil includes at least one turn around the compartment and is wound around the compartment so that the coil is spaced a certain distance from the compartment, and an air layer or other insulating material is located between the coil and the compartment. In various embodiments, the multi-turn coils are arranged closely together so that they are in contact with each other. In other embodiments, the multi-turn coils are arranged to have a certain distance between each other. In one embodiment, the multi-turn coils extend along the entire length of the compartment. In various embodiments, the multi-turn coils extend beyond the length of the compartment. In other embodiments, the multi-turn coils extend along a portion of the length of the compartment (which is less than the total length of the compartment).

[0242] Fig. 15B 15 is a flow chart that lists the steps of heating a compartment using induction heating. In step 1552, a metal coil is placed in relation to a compartment that includes a ferromagnetic material so that the coil surrounds the compartment. Subsequently, in step 1554, the compartment is filled with fluid via a proximal inlet on the compartment. In step 1556, an alternating current is provided to the coil to form a magnetic field in the region surrounding the compartment. The magnetic field induces an electric current (eddy current) flow in the ferromagnetic material, which heats the compartment. Heat is transferred to the fluid in the compartment and causes the fluid to evaporate. The evaporated fluid leaves the compartment via a distal outlet.

[0243] Fig.16AAn embodiment of a coil 1670 is shown for inductive heating of a vapor ablation system of the present specification. A cross section of the coil 1670 is cut out to aid viewing. The coil 1670 is positioned around a catheter fluid heating compartment 1651. The alternating current 1602 passing through the coil 1670 forms a magnetic field that induces eddy currents 1615 to flow in the compartment 1670, as described above. The flow of the eddy currents 1615 achieves heating of the catheter fluid heating compartment 1651. The heated compartment heats the fluid therein, converting it into vapor, which enters the catheter 1650 for use in an ablation procedure. The catheter 1650 includes at least one delivery port 1652 at its distal end for delivering vapor. Optionally, the catheter 1650 includes at least one positioning element 1653 near its distal end. In one embodiment, at least one positioning element 1653 is an inflatable capsule. The coil 1670 itself does not heat, making it safe to touch. A luer fitting connection 1649 is disposed at the proximal end of the catheter fluid heating compartment 1651 for connecting a tube supplying sterile water. In one embodiment, a one-way valve (not shown) is included at the proximal end of the catheter fluid heating compartment 1651, away from the luer fitting 1649, to prevent steam from traveling toward the water source. In one embodiment, an insulating material (not shown) is positioned between the coil 1670 and the heating compartment 1651. In another embodiment, the compartment 1651 is suspended in the center of the coil 1670 with no physical contact between the two. In this embodiment, the air in the middle serves as the insulating material. The design of the compartment is optimized to increase its surface area to maximize contact and heat transfer, which in turn enables more efficient steam generation. In one embodiment, the coil 1670 is constructed as a 'clamshell' style design, similar to Fig.16A A heat exchange unit 1660 is shown and can be opened and closed around the heating compartment 1651.

[0244] Fig. 16BOne embodiment of a catheter handle 1672 is shown for inductive heating of the vapor ablation system of the present specification. The handle 1672 is insulated and incorporates an inductive coil. In one embodiment, the handle 1672 includes an insulated tip 1673 at its distal end that engages the endoscope channel after the catheter is inserted into the endoscope. The catheter 1650 is connected to a heating compartment 1651, which in turn is connected to a pump via an insulating connector 1674. In one embodiment, the length and diameter of the heating compartment 1651 of the handle 1672 is less than the length and diameter of the inductive coil, whereby the heating compartment 1651 can slide in a coaxial manner in the handle 1672 while maintaining a constant position in the magnetic field generated by the inductive coil. The operator can manipulate the catheter 1650 by grasping on the insulating connector 1674 and moving it in and out of the handle 1672, which in turn moves the catheter tip in and out of the distal end of the endoscope. In this design, the heated portion of the catheter 1650 is within the channel of the endoscope and within the insulated handle 1672, thereby not contacting the operator at any time during operation. An optional sensor 1675 on the insulated tip 1673 can sense when the catheter is not engaged with the endoscope and temporarily deactivate the catheter's heating function to prevent accidental activation and thermal injury to the operator. Fig. 16B , the conduit 1650 and the heating compartment 1651 are the heated components of the system, while the handle 1672, the insulated end 1673, and the insulating connector 1674 are the cooling components and are therefore safe for the user to touch. The conduit 1650 includes at least one delivery port 1652 at its distal end for delivering steam. Optionally, the conduit 1650 includes at least one positioning element 1653 near its distal end. In one embodiment, at least one positioning element 1653 is a fillable capsule.

[0245] Fig. 16CA disassembled coil component 1611 and a heating compartment 1612 of an inductive heating system 1610 according to one embodiment of the present specification are shown. In some embodiments, the coil component 1611 includes an outer shell or bobbin 1609 around which the electromagnetic coil 1617 is wound. In other embodiments, the coil component 1611 includes only the coil 1617. In some embodiments, the coil 1617 includes solid copper wire. In other embodiments, the coil 1617 includes copper tubing to allow cooling water to pass through the tubing. In various embodiments, due to the rigidity of the wire or tubing, the copper wire or copper tubing can be mechanically self-supporting (no bobbin is required) and has very little winding. In some embodiments, the copper wire or copper tubing has 10 turns of winding, with space between each turn of winding, so that insulation can be omitted. In another other embodiment, the coil 1617 includes a multi-stranded stranded wire (litz wire: Litz wire), which has hundreds of individual strands of wire insulated from each other to deal with the skin effect and allow low-loss high-frequency operation. In some embodiments, each conductor is an AWG46 stranded wire. In some embodiments, where the coil 1617 comprises a plurality of strands of twisted wire, a bobbin 1609 is required to support and allow the coil 1617 to be wound around it. A wire 1619 is attached to the coil 1617 for providing radio frequency (RF) energy to the coil 1617. In some embodiments, the wire 1619 providing an electrical connection to the inductive heating system 1610 is coupled to a fluid connection that supplies fluid to the steam delivery system. The electrical connection is coupled to the fluid connection while providing a mechanically stable fluid connection and a connection of the RF coil to the wire from the generator to complete the circuit. This connection serves as a failsafe when an incomplete fluid connection causes no electrical connection and the inductive heating cannot be turned on. The coil assembly 1611 has an elongated shape having a proximal end and a distal end, and further includes an opening 1613 at its proximal end configured to receive a heating compartment 1612. The heating compartment 1612 includes an internal conductive or ferromagnetic core 1614 and includes an inlet 1618 at its proximal end for connecting to a fluid source and an outlet 1616 at its distal end for delivering the generated steam. A space 1655 exists between the core 1614 and the walls of the heating compartment 1612 where heating energy from the core 1614 is transferred to the fluid in the compartment 1612 to convert the fluid into steam.

[0246] Fig.16D An assembled induction heating system 1610 is shown, comprising Fig. 16CThe coil component 1611 and the heating compartment 1612 are shown in FIG. The heating compartment 1612 has been inserted through the opening 1613 and can move longitudinally in the coil component 1611. The RF energy supplied to the coil 1617 through the wire 1619 is converted into a magnetic field around the coil 1617, which induces the formation of heating energy in the core 1614 through eddy current loss and hysteresis loss. The fluid supplied at the input port 1618 is converted into steam by the heating energy in the space 1655 in the heating compartment 1612 and leaves through the outlet 1616.

[0247] In some embodiments, see also Fig. 16C and 16D , the induction heating system 1610 further includes a mechanism for retaining the heating compartment 1612 within the coil assembly 1611 once assembled, while still allowing some coaxial movement of the heating compartment 1612 within the coil assembly. In some embodiments, see Fig. 16C , the first stop mechanism 1658 includes a portion of the coil 1617 that has been positioned in a plane defined by the opening 1613. The first stop mechanism 1658 acts as a mechanical stopper so that the heating compartment 1612 can slide from the proximal end into the coil component 1611 and then abut the stop mechanism 1658 at the distal end, preventing further movement in the distal direction. In other embodiments, the second stop mechanism 1659 is disposed on the proximal end of the winding drum 1609. In various embodiments, the second stop mechanism includes a Luer lock or other connector. In some embodiments, the second stop mechanism 1659 is similar to Figure 16R and 16SThe spring-loaded connector shown. A portion of the second stop mechanism 1659 extends into the opening 1613. In order to insert the heating compartment 1612 into the coil component 1611, the second stop mechanism 1659 is depressed so that the extension is retracted and a complete opening 1613 is provided. While the second stop mechanism 1659 is depressed, the heating compartment 1612 slides into the coil component 1611 through the opening 1613 at the proximal end of the coil component 1611. Once the heating compartment 1612 has been fully inserted, the second stop mechanism 1659 is released and the extension extends into the opening 1613 again, acting as a stop for the heating compartment 1612 in the proximal direction. In some embodiments, the inductive heating system 1610 includes a first stop mechanism 1658 and a second stop mechanism 1659, wherein the distance between the first stop mechanism 1658 and the second stop mechanism 1659 is greater than the length of the heating compartment 1612 to allow some coaxial movement of the heating compartment 1612 in the coil component 1611. In other embodiments, the inductive heating system 1610 includes only the first stop mechanism 1658. In other embodiments, the inductive heating system 1610 includes only the second stop mechanism 1659. In various embodiments, the heating compartment 1612 can coaxially move in the coil component 1611 through a distance equal to at least 5% of the length of the coil 1617. In various embodiments, the coil component 1611 and the heating compartment 1612 can be moved coaxially in the handle (e.g., Fig. 16B The heating compartment 1612 and the coil component 1611 are coaxially moved in the handle 1672) through a distance equal to at least 5% of the length of the handle. In some embodiments, one or both of the heating compartment 1612 and the coil component 1611 are disposable. In some embodiments, the heating induction system 1610 further includes a sensor 1671, which is configured to sense parameters of the system 1610 and inform the user that it is safe to disconnect the heating compartment 1612 from the coil component 1611. For example, in one embodiment, the sensor 1671 is a temperature sensor that senses the temperature of the heating induction system 1610 and signals the user when the system temperature has been sufficiently reduced so that the heating compartment 1612 is safe to touch without risk of burns and can be removed from the coil component 1611. In various embodiments, other heating compartment and coil component embodiments described below include reference Fig. 16C and 16D The first stop mechanism, the second stop mechanism and the sensor. In some embodiments, Fig. 16C and 16D The heating compartment and coil are similar to those of the reference Figure 16K to 16M Those described.

[0248] Fig.16E and 16FA first conventional endoscope handle 1640 and a second conventional endoscope handle 1644 are shown, respectively, for use with the inductive heating system of the present specification. The endoscope handles 1640, 1644 include, among other controls, air / water buttons 1641, 1646 for providing air or fluid to a body cavity, suction buttons 1642, 1647 for applying suction to the body cavity, and biopsy or working channels 1643, 1648 for inserting working tools and removing body tissue. In various embodiments of the present specification, the inductive heating system (e.g., reference Figures 16G to 16S described) are connected to the biopsy or working channels 1643, 1648 to provide steam to the body cavity.

[0249] Figure 16G A disassembled coil component 1621 and a heating compartment of an inductive heating system 1620 for use with an endoscope according to one embodiment of the present specification are shown. In some embodiments, the coil component 1621 includes an outer housing having an electromagnetic coil 1627. In other embodiments, the coil component 1621 includes only the coil 1627. A wire 1629 is attached to the coil 1627 for providing radio frequency (RF) energy to the coil 1627. The coil component 1621 has an elongated shape with a proximal end and a distal end and further includes an opening 1623 at its proximal end (which is configured to receive the heating compartment 1622) and a connector 1625 at its distal end (which is configured to attach to the working channel port of the endoscope). The heating compartment 1622 includes an internal conductive or ferromagnetic core 1624 and includes an inlet 1628 at its proximal end for connecting to a fluid source and a conduit 1626 at its distal end for conveying the generated steam. A space 1645 exists between the core 1624 and the walls of the heating compartment 1622 where heating energy from the core 1624 is transferred to the fluid in the compartment 1622 to convert the fluid into steam.

[0250] Fig.16H An assembled induction heating system 1620 is shown for use with Figure 16GThe invention relates to an endoscope including a coil component 1621 and a heating compartment 1622. The heating compartment 1622 has been inserted through the opening 1623 and can move longitudinally in the coil component 1621. The catheter 1626 has passed through the connector 1625 and is configured to extend along the length of the working channel of the endoscope. The movement of the heating compartment 1622 relative to the coil component 1621 allows the catheter 1626 to be positioned in the body cavity. The RF energy supplied to the coil 1627 by the wire 1629 is converted into a magnetic field around the coil 1627, which induces the formation of heating energy in the core 1624 through eddy current losses and hysteresis losses. The fluid supplied at the input port 1628 is converted into steam by the heating energy in the space 1645 in the heating compartment 1622 and leaves via the catheter 1626.

[0251] Fig.16I A disassembled coil component 1631 and a heating compartment 1632 of an inductive heating system 1630 for use with an endoscope according to one embodiment of the present specification are shown. In some embodiments, the coil component 1631 includes an outer housing having an electromagnetic coil 1637. In other embodiments, the coil component 1631 includes only the coil 1637. A wire 1639 is attached to the coil 1637 for providing radio frequency (RF) energy to the coil 1637. The coil component 1621 has an elongated shape with a proximal end and a rounded distal end and further includes an opening 1633 at its proximal end (which is configured to receive the heating compartment 1632) and a connector 1635 at its distal end (which is configured to attach to a working channel port of an endoscope). The heating compartment 1632 includes an internal conductive or ferromagnetic core 1634 and includes an inlet 1638 at its proximal end for connecting to a fluid source and a conduit 1636 at its distal end for conveying the generated steam. The distal end of the heating compartment 1632 is rounded to fit in the rounded distal end of the coil component 1631. A space 1677 exists between the core 1634 and the wall of the heating compartment 1632, wherein the heating energy from the core 1634 is transmitted to the fluid in the compartment 1632 to convert the fluid into steam. The heating compartment 1632 further includes a gripper 1676 for manipulating the compartment 1632 and allowing the compartment 1632 and the core 1634 to move relative to the coil component 1631.

[0252] Fig.16J shows the use of Fig.16IAssembled inductive heating system 1630 for use with an endoscope having a coil component 1631 and a heating compartment 1632. The heating compartment 1632 has been inserted through opening 1633 and can move longitudinally in the coil component 1631. The catheter 1636 has passed through the connector 1635 and is configured to extend along the length of the working channel of the endoscope. The movement of the heating compartment 1632 relative to the coil component 1631 via the manipulation of the gripper 1676 allows the catheter 1636 to be positioned in the body cavity. The RF energy supplied to the coil 1637 via the wire 1639 is converted into a magnetic field around the coil 1637, which induces the formation of heating energy in the core 1634 through eddy current losses and hysteresis losses. The fluid supplied at the input port 1638 is converted into steam by the heating energy in the space 1677 in the heating compartment 1632 and leaves via the catheter 1636.

[0253] Figure 16K An inductive heating system 1680 is shown including a handle 1686 configured to be attached to a conventional endoscope handle, according to one embodiment of the present specification. The handle 1686 of the inductive heating system includes at least one clamp 1681 for securing the inductive heating system 1680 to the endoscope handle.

[0254] In one embodiment, the inductive heating system includes two clamps 1681, one at the proximal end and one at the distal end of the handle 1686. The coil assembly 1684 is embedded in the handle 1686 and can be moved longitudinally about the heating compartment (not shown) by the manipulation of the wheel mechanism 1683 on the handle 1686. In one embodiment, a spring-loaded connector 1682 at the distal end of the handle 1686 attaches the inductive heating system 1680 to the working channel port of the endoscope handle. A catheter 1685 extends from the distal end of the heating compartment and is configured to pass through the working channel of the endoscope. An inlet 1687 extends from the proximal end of the heating compartment for connection to a fluid source.

[0255] Figure 16Lis a cross-sectional view of an inductive heating system 1690 according to one embodiment of the present specification, the system including a handle 1696 and having a wheel mechanism 1693 for moving a coil assembly 1694 relative to a heating compartment 1698. The coil assembly 1694 is embedded in the handle 1696 and can be moved longitudinally relative to the heating compartment 1698 and the core 1699 by manipulating the wheel mechanism 1693 on the handle 1696. A connector 1692 at the distal end of the coil assembly 1694 attaches the inductive heating system 1690 to a working channel port of an endoscope handle. In various embodiments, the connector 1692 is a Luer lock connector or a spring loaded connector. A catheter 1695 extends from the distal end of the heating compartment 1698, passes through the connector 1692, and is configured to extend through the working channel of the endoscope. An inlet 1697 extends from the proximal end of the heating compartment 1698 for connection to a fluid source. In some embodiments, the handle 1696 includes at least one mechanism, similar to Figure 16K A clamp 1681 is provided for attaching the induction heating system 1690 to the endoscope handle.

[0256] Figure 16M An inductive heating system 1600 according to one embodiment of the present specification is shown, which includes a heating compartment 1604 in a first position relative to a coil component 1603. In the first position, the heating compartment 1604 is located at a distal position relative to the coil component 1603. The inductive heating system 1600 includes a handle 1606 for manipulating the heating compartment 1604 relative to the coil component 1603. A connector 1608 is positioned at the distal end of the coil component 1603 for attaching the inductive heating system 1600 to the working channel port of the endoscope. The heating compartment 1604 includes an inlet 1607 at its proximal end (which is used to provide fluid to the heating compartment 1604) and a catheter 1605 at its distal end (which is configured to extend through the working channel of the endoscope). Fig.16N Shows Figure 16M In the induction heating system 1600 of FIG. 1 , the heating compartment 1604 is in a second position relative to the coil component 1603. In the second position, the heating compartment 1604 has been moved proximally relative to the coil component 1603 via manipulation of the handle 1606. Since the coil component 1603 is attached to the endoscope handle via the connector 1608, the position of the coil component 1603 remains fixed. The movement of the heating compartment 1604 enables similar movement of the attached catheter 1605 and fine-tuning of the positioning of the distal end of the catheter 1605 in the body cavity.

[0257] Fig.16OAn inductive heating system 1660 is shown according to one embodiment of the present specification, which includes a first handle member 1665 in a first position relative to a second handle member 1666. In one embodiment, the first handle member 1665 has an elongated body with a proximal end and a distal end and includes a heating compartment therein. In one embodiment, the second handle member 1666 has an elongated body with a proximal end and a distal end and includes a coil therein. The second handle member 1666 can be telescopic in and out of the distal end of the first handle member 1665. An inlet 1661 is included at the proximal end of the first handle member 1665 for providing fluid to the heating compartment. A connector 1668 is included at the distal end of the second handle member 1666 for attaching the inductive heating system 1660 to a working channel port of an endoscope handle. A catheter 1662 extends through the second handle member 1666 and is in fluid communication with the heating compartment in the first handle member 1665. In Fig.16O In the first position shown, the first handle member 1665 is positioned proximally relative to the second handle member 1666. The second handle member 1666 includes a plurality of markings 1663 along its body. In one embodiment, the markings 1663 are numbers. The first handle member 1665 includes a window 1664 near its distal end that aligns with one of the markings when the first handle member 1665 is longitudinally moved relative to the second handle member 1666. The markings 1663 in the window 1664 represent the length of the catheter 1662 that extends beyond the distal end of the working channel of the endoscope and into the patient's body cavity. Figure 16P Shows Fig.16O In the induction heating system 1660, the first handle member 1665 is in a second position relative to the second handle member 1666. The marking 1667 in the window 1664 informs the operator that the first handle member 1665 is in its most distal position relative to the second handle member 1666 and the catheter 1662 is fully extended in the patient's body cavity.

[0258] Figure 16Q A Luer lock mechanism 1669 is shown at the distal end of the handle of an inductive heating system 1660 according to one embodiment of the present specification. A catheter 1662 extends through the Luer lock mechanism 1669 and is configured to extend through the working channel of an endoscope. The Luer lock mechanism 1669 is configured to attach to a corresponding connector at the working channel port of the endoscope handle.

[0259] Figure 16R A spring loaded connector 1656 is shown at the distal end of the handle of an inductive heating system 1654 and in a first position according to one embodiment of the present specification. In the first position, the spring loaded connector 1656 is locked and secured to the working channel port of the endoscope handle. A catheter 1657 extends through the distal end of the inductive heating system handle. Figure 16SShown in the second position Figure 16R A spring loaded connector 1656 is provided, wherein the connector 1656 is depressed and opened for connection to a working channel port of an endoscope handle.

[0260] Figure 16T A closed loop steam delivery system 1600t for use with an endoscope is shown in accordance with one embodiment of the present specification. A closed loop conduit 1601t, a heating compartment 1602t, and a fluid channel 1603t (from a fluid source 1606t) are provided. In various embodiments, the fluid channel 1603t comprises a solid tube or housing and serves as a handle to be grasped and manipulated by a physician. The conduit 1601t is configured to be inserted into a working channel of an endoscope, such as Fig.16E The working channel 1643 of the catheter 1601t. The heating compartment 1602t is positioned in an inductive coil support structure 1604t, which is in turn attached to a drive circuit via a wire 1605t to provide power to the coil and generate inductive heating. Fluid is provided from a fluid source 1606t through a fluid channel 1603t and enters the heating compartment 1602t, where the fluid is converted into steam by the inductive heating provided by the inductive coil support structure 1604t. The steam travels through the catheter 1601t and is delivered to the target tissue via one or more openings 1607t at the distal end of the catheter 1601t. In some embodiments, the catheter 1601t further includes one or more positioning elements, such as a fillable balloon, for positioning the catheter 1601t in a body cavity. The inductive coil support structure 1604t moves with the heating compartment 1602t. The physician grasps the fluid channel 1603t, which also serves as, and moves the catheter 1601t as needed via an endoscope. Using the closed loop system 1600t to deliver steam for ablation therapy involves simply inserting the catheter 1601t into the endoscope and moving it back and forth.

[0261] Figure 16U It shows the use Figure 16T Flowchart of the steps involved in one embodiment of a method for providing steam ablation therapy with a steam delivery system of the invention. In step 1602u, a catheter of a closed-loop steam delivery system is inserted into a working channel of an endoscope. In step 1604u, the inductive coil support structure is then connected to a drive circuit via a wire. In step 1606u, the drive circuit provides current to the coil to achieve inductive heating of the heating compartment. In step 1608u, a fluid is supplied from a fluid source and passes through a fluid channel to the heating compartment, where the fluid is converted to steam. In step 1610u, the physician grasps the fluid channel and moves the closed-loop system in the endoscope channel or moves the entire endoscope to position the distal end of the catheter proximate to the target tissue for steam ablation.

[0262] Figure 16VA closed loop steam delivery system 1600v for use with an endoscope is shown in accordance with another embodiment of the present specification. A closed loop conduit 1601v, a heating compartment 1602v, and a fluid channel 1603v (from a fluid source 1606v) are provided. In various embodiments, the fluid channel 1603v comprises a solid tube or housing and acts as a handle to be grasped and manipulated by the physician. In this embodiment, the heating compartment 1602v is too large to be moved back and forth without support. Therefore, the system 1600v includes an endoscope handle attachment 1608v, similar to Figure 16K The handle 1686 is shown. The catheter 1601v is configured to be inserted into the working channel of an endoscope, such as Fig.16E The handle portion of the working channel 1643, heating compartment 1602v and fluid channel 1603v is positioned in the endoscope handle attachment 1608v. Figure 16V In the illustrated embodiment, the endoscope handle attachment 1608v has a built-in inductive coil. The built-in coil is in turn attached to a drive circuit via a wire 1605v to power the coil and generate inductive heating. Fluid is provided from a fluid source 1606v through a fluid channel 1603v and enters a heating compartment 1602v, where the fluid is converted into steam by inductive heating provided by the built-in coil of the endoscope handle attachment 1608v. The steam travels through the catheter 1601v and is delivered to the target tissue via one or more openings 1607v at the distal end of the catheter 1601v. In some embodiments, the catheter 1601v further includes one or more positioning elements, such as an inflatable balloon, for positioning the catheter 1601v in a body cavity. The endoscope handle attachment 1608v moves with the heating compartment 1602v. The physician flips a switch on the endoscope handle attachment, which manipulates the fluid channel 1602v, which also serves as a handle, and moves the catheter 1601v as needed via the endoscope. In this embodiment, a closed loop system 1600v inserted into an endoscope moves back and forth and a heating compartment 1602v is held in a field created by a stationary inductive coil in an endoscope handle attachment 1608v.

[0263] Figure 16W It shows the use Figure 16VFlowchart of the steps involved in one embodiment of a method for providing steam ablation therapy with a steam delivery system. In step 1602w, the catheter of the closed-loop steam delivery system is inserted into the working channel of the endoscope. In step 1604w, the endoscope handle attachment (containing a built-in coil) is then connected to the drive circuit via a wire. In step 1606w, the drive circuit provides current to the coil to achieve inductive heating of the heating compartment. In step 1608w, fluid is supplied from a fluid source and reaches the heating compartment through the fluid channel, where the fluid is converted into steam. In step 1610w, the physician flips a switch on the endoscope handle attachment, which moves the catheter in the endoscope channel or moves the entire endoscope to position the distal end of the catheter close to the target tissue for steam ablation.

[0264] Figure 16X A closed loop steam delivery system 1600x for use with an endoscope is shown in accordance with yet another embodiment of the present specification. A closed loop conduit 1601x, a heating compartment 1602x, and a fluid channel 1603x (from a fluid source 1606x) are provided. In various embodiments, the fluid channel 1603x comprises a solid tube or housing and serves as a handle to be grasped and manipulated by the physician. In this embodiment, the heating compartment 1602x is too large to be moved back and forth without support. Therefore, the system 1600x includes an endoscope handle attachment 1608x, similar to Figure 16K The handle 1686 is shown. The catheter 1601x is configured to be inserted into the working channel of an endoscope, such as Fig.16E The handle portion of the working channel 1643, heating compartment 1602x and fluid channel 1603x is positioned in the endoscope handle attachment 1608x. Figure 16XIn the illustrated embodiment, the inductive coil 1609x is attached to and wrapped around the heating compartment 1602x and is not included as part of the endoscope handle attachment 1608x. The inductive coil 1609x is in turn attached to a drive circuit via a wire 1605x to power the coil and generate inductive heating. Fluid is provided from a fluid source 1606x through a fluid channel 1603x and enters the heating compartment 1602x, where the fluid is converted into steam by the inductive heating provided by the inductive coil 1609x. The steam travels through the catheter 1601x and is delivered to the target tissue via one or more openings 1607x at the distal end of the catheter 1601x. In some embodiments, the catheter 1601x further includes one or more positioning elements, such as a fillable sac, for positioning the catheter 1601x in a body cavity. The endoscope handle attachment 1608x moves with the heating compartment 1602x, however, the heating compartment 1602x and the inductive coil 1609x move together because they are physically attached to each other. The physician flips a switch on the endoscope handle attachment, which manipulates the fluid channel 1602x, which also serves as a handle, and moves the catheter 1601x as needed through the endoscope. In this embodiment, the closed loop system 1600x inserted into the endoscope moves back and forth, and the heating compartment 1602x and the attached inductive coil 1609x move together relative to the endoscope handle attachment 1608x.

[0265] Figure 16Y It shows the use Figure 16X Flowchart of the steps involved in one embodiment of a method for providing steam ablation therapy with a steam delivery system of the invention. In step 1602y, a catheter of a closed-loop steam delivery system is inserted into a working channel of an endoscope. In step 1604y, an inductive coil attached to a heating compartment is then connected to a drive circuit via a wire. In step 1606y, the drive circuit provides current to the coil to achieve inductive heating of the heating compartment. In step 1608y, a fluid is supplied from a fluid source and reaches the heating compartment through a fluid channel, where the fluid is converted into steam. In step 1610y, the physician flips a switch on an endoscope handle attachment, which moves the catheter in the endoscope channel or moves the entire endoscope to position the distal end of the catheter close to the target tissue for steam ablation.

[0266] According to some aspects, the present specification provides a handle mechanism that can be used in conjunction with an endoscope to manipulate the ablation catheter disclosed in various embodiments. Fig.17A An exemplary display of handle 1780 is provided. Fig.17A, the handle 1780 includes a port 1781 for receiving and holding an ablation catheter. The handle 1780 further includes a clamp 1782 for securing to an endoscope (not shown). The handle also includes a clamp 1783 for securing or attaching a cable 1785. The cable is used to power an RF coil 1784, which is located in a compartment or port 1786 in the handle 1780. In one embodiment, the RF coil is located in a port on the handle that communicates with the port 1781 that receives the ablation catheter.

[0267] When alternating current is supplied to the RF coil 1784 via a cable, the RF coil, which comprises a metal coil wound around a ferromagnetic core, forms a magnetic field. In one embodiment, the compartment 1786 comprises an iron-containing material (e.g., iron, stainless steel, or copper). Due to the presence of alternating current and the magnetic field, this causes currents called eddy currents to flow in the compartment, as previously described in the specification. The eddy currents cause compartment 1786 to be locally heated. When compartment 1786 is filled with a fluid (e.g., water), heat is transferred from the compartment to the fluid inside, causing the fluid to vaporize. The vapor is supplied to the catheter through port 1781 for ablation. It should be noted that Fig.17A The compartment and coil configuration display only show a feasible embodiment and are not restrictive. Those skilled in the art will appreciate that many different design configurations for compartments and coils are also possible. In one embodiment, for example, the RF coil heats the fluid in the heating compartment of the catheter inserted into the handle so that the fluid is converted to steam, for ablation. In this case, the heating compartment is used as a part for the catheter assembly.

[0268] Fig. 17B Provides attachment to endoscope 1787 Fig.17A The handle mechanism 1780 is shown. Fig. 17B , the RF coil 1784 of the handle is positioned in a port on the handle. In one embodiment, once the handle is clamped to the endoscope, the RF coil is positioned over and communicates with another port on the endoscope, which is configured to receive an ablation catheter.

[0269] In one embodiment, handle 1780 is disposable. In another embodiment, handle 1780 is reusable.

[0270] Fig. 17C An alternative embodiment of a handle mechanism is shown in which the handle 1780 also includes a support member 1788 that connects the catheter port 1781 to the proximal portion 1789 of the handle. This provides additional support for the port and catheter once the catheter has been inserted. The support member 1788 is also shown in FIG. Fig.17D , where handle 1780 is shown attached to endoscope 1787.

[0271] Fig.17EAnother illustration of the handle mechanism 1790 is provided. Fig.17E In one embodiment, the handle includes a fastener 1791, such as a clamp or bracket, for securing the handle to the endoscope. In one embodiment, the fastener 1791 can be clamped around the endoscope to attach the handle to the endoscope. In one embodiment, the clamp 1791 is attached to the handle unit via a hinge 1792. The hinge mechanism allows the clamp or fastener to be easily opened, such as Fig.17F As shown, and can also be easily closed, such as Figure 17G shown.

[0272] Fig.17H A handle 1790 is shown attached to an endoscope 1793 via a clamp 1791. Fig.17H In one embodiment, the handle is equipped with a catheter 1794 for passing an ablative fluid through. Prior to clamping the handle to the endoscope, the catheter 1794 is inserted into the biopsy port 1795 of the endoscope, from which the catheter is advanced through the working channel of the endoscope until it exits the distal end of the endoscope. The fluid enters a heating compartment 1796 where it is heated and converted to steam, passes through the catheter 1794 and passes as steam through the distal end of the catheter at the distal end of the endoscope to ablate the desired tissue. Details of the heating compartment 1796 are described in Fig.17A The handle is also equipped with a knob 1797 for maneuvering the ablation catheter 1794 into and out of the endoscope without requiring the operator to physically contact the catheter shaft.

[0273] Fig.18Ais a schematic diagram of a steam ablation system 1800 using inductive heating according to one embodiment of the present specification. The steam ablation system 1800 includes a fluid circuit, which includes a water reservoir 1802, a heating compartment 1804, and a catheter 1810 connected by adjacent fluid channels. In various embodiments, the adjacent fluid channels connecting the components of the fluid circuit include a flexible tubing with an inner lumen. In various embodiments, one or more components of the fluid circuit are disposable, so that separated components are discarded or replaced after a single use, or the entire fluid circuit is discarded after a single use. In one embodiment, before use, a portion of the fluid channel positioned between the water reservoir 1802 and the heating compartment 1804 is blocked by a barrier, thereby preventing water from passively flowing from the water reservoir 1802 to the heating compartment 1804. In one embodiment, a one-way valve or fracture diaphragm 1807 is positioned in the adjacent fluid passage between the water reservoir 1802 and the heating compartment 1804 to prevent water from entering the heating compartment 1804 until force is applied to the water to direct it into the heating compartment 1804. During operation, as water is acted upon by a pump or drive mechanism, the barrier, one-way valve, or fracture diaphragm 1807 opens due to an increase in water pressure, allowing water to flow from the water reservoir 1802 to the heating compartment 1804.

[0274] Water travels from reservoir 1802 into heating compartment 1804, where it is converted into steam. The final steam travels into catheter 1810 and flows out of its distal end as an ablative agent. The only path for water and steam to travel is from reservoir 1802 through heating compartment 1804 and out of the distal end of catheter 1810. In various embodiments, no other input, port, or opening receives fluid from an external source into the fluid circuit. In various embodiments, no other output, port, or opening receives or discharges fluid outside the fluid circuit. In various embodiments, water reservoir 1802 comprises a flexible bag, a syringe, or any three-dimensional enclosure configured to contain a predetermined volume of water.

[0275] The heating compartment 1804 is configured to be positioned in the inductive coil 1805. In various embodiments, the heating compartment can be cylindrical, cubic, or any other shape. In some embodiments, the inductive coil 1805 includes an inductive compartment 1801 having a cylindrical space and a cavity 1803 therein, around which a plurality of coils are positioned, the cavity being configured to receive the heating compartment 1804. In other embodiments, the inductive coil 1805 includes only the coil itself, which is wound around the heating compartment 1804. The inductive coil 1805 includes a plurality of coils for receiving an electric current and generating a magnetic field, which causes inductive heating of the ferromagnetic portion of the heating compartment 1804. In various embodiments, the frequency of the current provided to the inductive coil is 100 Hz-200 kHz, more preferably 1 kHz-100 kHz, more preferably 10 kHz-50 kHz, and most preferably 25 kHz-35 kHz. In various embodiments, the heating compartment 1804 is thermally insulated to prevent heat loss from the compartment and / or to prevent thermal injury to an operator.

[0276] Water is directed from the reservoir 1802 to the heating compartment 1804 via a force applied by a pump, motor or other mechanism. In various embodiments, water is directed to the heating compartment 1804 by a pump driven by a motor, as described further below. In other embodiments, the water reservoir 1802 is elevated relative to the heating compartment 1804 and water from the reservoir 1802 is supplied to the heating compartment 1804 by gravity. In other embodiments, the mechanism for delivering water from the reservoir 1802 to the heating compartment 1804 includes a bladder tank. In one embodiment, the bladder tank includes a diaphragm separating two compartments in one box. The first compartment contains compressed air and the second compartment contains water. The compressed air pushes on the diaphragm, forcing the water to leave the second compartment and enter the heating compartment. In another embodiment, the mechanism for delivering water from the reservoir 1802 to the heating compartment 1804 includes an occluded water tank. The closed water tank functions similarly to a toothpaste tube, where a portion of the closed water tank can be compressed and squeezed to force water out of the tank and into the heating compartment.

[0277] In various embodiments, the fluid from the water reservoir 1802 is pumped into the heating compartment 1804 with an accurate dosage. In one embodiment, the water reservoir 1802 is configured to contain 200 ml of water. An accurate and controllable volumetric metering pump (dosing pump) delivers an accurate amount of water to the inductive heating compartment 1804 on demand for vaporization. Inductive heating is preferred because it allows the heating of elements in the sterile catheter without including sterile facilities and requiring no complicated electrical lead connections. In addition, the catheter itself can be disposable and therefore manufactured at low cost. In one embodiment, the heating compartment includes 1804 metal cores and is vertically installed. In one embodiment, the metal is steel. Water is introduced at the bottom of the heating compartment 1804 at the entrance of its proximal end. Further as described below, in one embodiment, the metal core is a smooth rod having an outer diameter slightly smaller than the inner diameter of the tube coaxially positioned above the core. An inductive coil 1805 is wound around the tube of the heating compartment 1804. The core and tube comprise a heating compartment 1804. Water introduced into the heating compartment 1804 passes through the space between the core and the tube. Thus, all the water is forced into close proximity to the core, contacts the metal surface, evaporates and completely leaves the compartment as steam, provided sufficient heating power is provided for a given flow rate. The steam formed in the heating compartment 1804 leaves via an outlet at its distal end.

[0278] The generated steam is delivered to a Luer lock connector 1808 connected to an input port of a catheter 1810. The catheter 1810 is designed so that all parts that come into direct contact with the steam can withstand temperatures in excess of 100° C., preventing melting and subsequent leakage or blockage. The catheter 1810 includes one or more openings at its distal end for delivering steam 1814 to the target tissue. In various embodiments, the catheter 1810 includes one or more positioning attachments 1816 near its distal end. In one embodiment, the positioning attachment 1816 includes an inflatable balloon and the catheter 1810 further includes an injection port 1818 at its proximal end. An air pump 1820 connected to the injection port 1818 is used to fill the balloon. In various embodiments, the positioning attachment or balloon 1816 is filled with air by the air pump 1820, and the air then expands once steam is generated by the system 1800. In some embodiments, one or more capsules 1816 are first filled to the positioning volume by air pump 1820, and then further expanded to the closed volume when heated air is delivered by steam, establishing a seal without perforation. In one embodiment, the closed space is less than 120% of the positioning space. In various embodiments, one or more capsules 1816 include silicone. Silicone is thermally insulating, so the heat generated by ablation in the area near the outside of capsule 1816 will not be passively transmitted and expand the air in capsule 1816. Therefore, in some embodiments, the air used for filling must be actively heated from within the catheter and enter the capsule 1816 to achieve the desired heating expansion. In various embodiments, the catheter 1810 has a coaxial design so that the heating energy from the steam is transmitted to the air used for filling because both the air and the steam travel along the catheter 1810. The coaxial design of the catheter 1810 allows the heat loss along the catheter to be captured and transmitted to the air in the capsule 1816 to produce a seal that can be suitable for treatment. In other embodiments, the conduit 1810 includes a coaxial lumen for heating the air, or the bladder 1816 includes a conductive metal on the interior for conducting heat from the steam in the conduit to the air in the bladder 1816.

[0279] When air is heated from 37°C (body temperature) to 100°C, the air will expand by approximately 20%. Therefore, in one embodiment, the one or more bladders 1816 are filled to approximately 75% using air pump 1820, allowing the remaining volume expansion to be achieved by heat transfer from the steam. Because the steam is not directed into the bladder 1816, the pressure in the bladder 1816 is not significantly changed. The air used to fill the one or more bladders 1816 behaves like an ideal gas at temperatures below 400°C, such as Fig.18B As shown, it basically follows the ideal gas law:

[0280] PV=nRT

[0281] Where P is the absolute pressure of the gas, V is the volume of the gas, n is the amount of gas, R is the ideal gas constant, and T is the absolute temperature of the gas in Kelvin (°C + 273). Fig.18B , air behaves less like an ideal gas as it is heated above about 400° C., wherein at temperatures above 400° C., the density curves of ammonia 1815, nitrogen 1817, and helium 1819 become non-linear. In various embodiments, the air used to fill the balloon is defined by at least three different temperatures: a starting temperature (T start ); ideal temperature (T ideal ); and, maximum temperature (T max ). In various embodiments, T start Equal to 25℃ (room temperature), T ideal Less than or equal to 75°C, and T max =125°C. In various embodiments, the volume expansion of the capsule is at T max Lower relative to T start The volume under is 2% to 40%, and at T ideal Lower relative to T start The volume under the pressure is 1% to 20% of it. In various embodiments, the system has a maximum continuous operation time of less than or equal to 5 minutes, and an ideal continuous operation time of less than or equal to 2 minutes. In various embodiments, the bladder is configured to have a maximum diameter change or expansion of less than or equal to 5 mm, and an ideal diameter change or expansion of less than or equal to 3 mm. At substantially fixed pressure, different temperatures provide a volume ratio equal to the temperature ratio. Therefore, in an embodiment with the above operating parameters, the air is changed from 25°C (T start )Heat to 125℃(T max ) provides a temperature increase of 100K (398K / 298K), which translates into a volume expansion of less than or equal to 33%. In an embodiment with the above operating parameters, air is heated from 25°C (T start )Heat to 75℃(T ideal ) provides a temperature increase of 50K (348K / 298K), which translates to a volume expansion of less than or equal to 17%. In various embodiments, the bladder has a first diameter or positioning diameter when inflated by the action of the air pump, and has a second diameter or closed diameter when the pumped air is heated by steam generated by the system, as listed in Table 1 below:

[0282] Table 1

[0283] Positioning diameter Closed diameter Volume change percentage 18mm 21mm 36％ 20mm 23mm 32％ 22mm 25mm 29％

[0284] Referring to Table 1, a bladder having a positioning diameter of 18 mm expands to a closed diameter of 21 mm when the filling air is heated by nearby steam, an increase of 36%. A bladder having a positioning diameter of 20 mm expands to a closed diameter of 23 mm when the filling air is heated by nearby steam, an increase of 32%. A bladder having a positioning diameter of 22 mm expands to a closed diameter of 25 mm when the filling air is heated by nearby steam, an increase of 29%.

[0285] In another embodiment, further volume expansion of the bladder is undesirable and the volume of the bladder is held constant by monitoring the pressure in the bladder and allowing a portion of the inflated air to escape the bladder to keep the pressure, and therefore the volume, constant.

[0286] Fig.19A is a vertical cross-sectional view of an inductively heated compartment 1901 according to one embodiment of the present specification, and Fig.19B yes Fig.19A Figure 1 shows an inductively heated compartment of FIG. 1 , which shows the components of the compartment in further detail. See also Fig.19A and 19B , the heating compartment 1901 includes a ferromagnetic core 1903 contained in a non-ferromagnetic shell or thermoplastic container 1905. The thermoplastic container 1905 includes an inlet 1906 at its proximal end and an outlet 1908 at its distal end. An inductor 1909 is wound around the thermoplastic container 1905. A first portion of a non-thermoplastic insulating portion 1910 is positioned in the thermoplastic container 1905 and between the ferromagnetic core 1903 and the wall of the thermoplastic container 1905. A second portion of a non-thermoplastic insulating portion 1911 is positioned between the inductor 1909 and the wall of the thermoplastic container 1905.

[0287] In some embodiments, thermoplastic container 1905 has a length of 2.75 inches to 3.75 inches, an inner diameter of 7 / 32 inches to 11 / 32 inches, and an outer diameter of 3 / 8 inches to 0.5 inches. In some embodiments, ferromagnetic core 1903 has a length of 1.5 inches to 2.5 inches and a diameter of 3 / 16 inches to 5 / 16 inches.

[0288] In various embodiments, the thermoplastic container 1905 includes PEEK, ABS, acetal, polyamide, or polyvinylidene fluoride (PVDF). In some embodiments, the non-thermoplastic insulating portion 1910 of the first portion includes a rolled film of mica to form a stand-off in the distal and proximal ends of the thermoplastic container 1905 to prevent the ferromagnetic core 1903 from contacting the PEEK. The periphery of the mica roll also extends along the length in the thermoplastic container 1905 to prevent the ferromagnetic core from contacting the PEEK wall. A pair of central openings 1912, 1914 are positioned in the proximal and distal ends of the mica roll to allow water to flow into the space between the mica roll and the ferromagnetic core 1903.

[0289] In some embodiments, the ferromagnetic core 1903 is a single piece and includes grooves 1998 around its periphery. The grooves 1998 are configured to allow water or steam to flow along the core 1903. In one embodiment, the ferromagnetic core 1903 includes grooves or recesses 1915 formed in its proximal and distal ends, forming channels for water or steam to flow between the core 1903 and the surrounding insulation 1910. In another embodiment, the proximal and distal ends of the ferromagnetic core are flat and the insulation 1910 includes grooves or recesses formed into its surfaces that contact the proximal and distal ends of the ferromagnetic core to form channels for water and steam to flow.

[0290] Fig.19C yes Fig.19A Horizontal cross-sectional view of an inductive heating compartment 1901 of FIG. The inductive heating compartment 1901 includes a ferromagnetic core 1903 surrounded by a first portion of non-thermostyrenic insulating portion 1910, which is surrounded by a thermostyrenic container 1905, which is in turn surrounded by a second portion of non-thermostyrenic insulating portion 1911. An inductive coil 1909 is wound around the second portion of non-thermostyrenic insulating portion 1911. In one embodiment, the ferromagnetic core 1903 is shaped such that a plurality of channels 1999 are formed along its outer surface to allow water or steam to flow between the ferromagnetic core 1903 and the first portion of non-thermostyrenic insulating portion 1910 in a proximal to distal direction.

[0291] Cardiac Ablation

[0292] Fig. 20A A cardiac ablation catheter 2042 according to one embodiment of the present specification is shown. Fig. 20B pass Fig. 20AThe invention relates to a cardiac ablation procedure performed by a cardiac ablation catheter 2042. The cardiac ablation catheter 2042 can be used to ablate tissue of the heart to treat cardiac arrhythmias, such as atrial fibrillation. The catheter 2042 includes an elongated inner shaft 2043 covered by an outer shaft 2044. The inner shaft 2043 includes an inflatable balloon 2045 near its distal end. The inflatable balloon is in fluid communication with an air / steam channel 2034 or with a first pump 2033, which extends from the balloon 2045 through the inner shaft 2043 and reaches an air source, which is in data communication with and controlled by the controller 2030. The air source 2033 draws air from the external environment through an optional filter 2038 to fill the inflatable balloon 2045. In one embodiment, the air source or first pump 2033 is reversibly configured to allow air to be pumped into the balloon 2045 or outside the balloon 2045 as needed according to instructions sent through the controller 2030. A mapping member 2046, which may be a radial extension, a catheter or any substrate including a plurality of sensors, detectors or electrodes, is attached to the distal end of the inner shaft 2043 away from the capsule 2045. The mapping member 2046 maps the area of ​​cardiac tissue causing the arrhythmia. The distal end of the outer shaft 2044 terminates at a distance close to the capsule 2045 so that a portion of the inner shaft 2043 between the capsule 2045 and the outer shaft 2044 is exposed. Water 2047 may be pumped from the sterile water reservoir 2031 via the second pump 2032 through the first water chamber 2035 in the outer shaft 2044, where the water exits near the capsule 2045 for cooling the space near the capsule 2045. Water 2037 may also be pumped from the sterile water reservoir 2031 via the second pump 2032 through the second water chamber 2036 in the inner shaft 2043, where the water exits at a location away from the bladder 2045 and near the delineation member 2046 for cooling the space away from the bladder 2045. The first water chamber 2035 extends in the outer shaft 2044 from the second pump 2032 to the distal end of the outer shaft 2044. The second water chamber 2036 extends in the inner shaft 2043 from the second pump 2032 to the distal end of the inner shaft 2043. The controller 2030 is in data communication with and controls the second pump 2032, where the second pump 2032 is configured to allow water 2047, 2037 from the sterile water reservoir 2031 to enter the first water chamber 2035 and / or the second water chamber 2036 of the outer shaft 2044 and the inner shaft 2043, respectively. The capsule 2045 includes an ablation or heat zone 2048 near its equator and a first cold zone in its top hemisphere 2049 which is cooled by water 2037 pumped by the inner shaft 2043 and a second cold zone in its bottom hemisphere 2050 which is cooled by water 2047 pumped by the outer shaft 2044.The temperature of the ablation or hot region 2048 is typically 60-100°C and the temperature of the cold regions 2049, 2050 is typically 35-60°C, with the temperature of the cold regions 2049, 2050 decreasing as the cold regions 2049, 2050 extend away from the hot regions 2048. The equator hot regions 2048 are kept heated by the steam used to heat the interior of the bladder 2045 and are far enough away from the water 2037, 2047 pumped through the inner shaft 2043 and the outer shaft 2044 that they do not get cold. See. Fig. 20B , the balloon 2045 of the catheter 2042 has been positioned in the heart 2051, near the pulmonary vein 2052. Heat supplied to the balloon 2045 by steam is transferred from the hot region 2048 to the target cardiac tissue 2053 to ablate the tissue 2053 and treat the arrhythmia. Hot region 2048 The hot region 2048 is defined by the portion of the balloon in contact with the target cardiac tissue 2053, where the water used for cooling does not contact the balloon surface, while the cold regions 2049, 2050 are defined by the portion of the balloon not in contact with the target cardiac tissue 2053, allowing water to contact and cool the balloon surface. In some embodiments, the two temperature regions can also be defined by constructing the balloon with two different materials having different thermal conductivities.

[0293] Fig. 20C It shows the use Fig. 20A Flowchart of the steps involved in one embodiment of a method for ablating cardiac tissue using a catheter of a ventricular ablation apparatus. In step 2054, a mapping catheter is used to map a region of the heart prone to arrhythmia. In step 2055, the balloon is filled with air to a first pressure (P1) so that the balloon contacts the target arrhythmic tissue. In step 2056, water is injected to cool the catheter and optionally the top and bottom hemispheres of the balloon. In some embodiments, blood helps cool the top and bottom hemispheres of the balloon. In step 2057, steam is injected into the balloon to heat the interior of the balloon while removing air from the balloon to maintain a second pressure (P2) equal to P1 + / - 25%. The amount of steam delivered to the balloon can also be modulated (without removing air) to maintain the second pressure (P2) equal to P1 + / - 25%. In step 2058, a hot area on the balloon is formed by the injected steam, wherein the hot area contacts the cardiac tissue to achieve ablation.

[0294] Fig.20DA cardiac ablation catheter 2060 according to another embodiment of the present specification is shown. The catheter 2060 includes an elongated body 2061, a proximal end, and a distal end, and an air / water chamber 2062 and a steam chamber 2063 are supplied through a port at its proximal end. The air / water chamber 2062 is in fluid communication with a delineation balloon 2064 attached to the distal end of the catheter 2060. The delineation balloon 2064 includes a plurality of delineation electrodes 2066 in or attached to the outer surface of its wall. The delineation electrodes 2066 delineate the cardiac tissue area causing the arrhythmia. The steam chamber 2063 is in fluid communication with an ablation balloon 2065 attached to the distal end of the catheter 2060 and positioned in the delineation balloon 2064. Once the two balloons 2064, 2065 are filled, the length of the delineation balloon 2064 is greater than the length of the ablation balloon 2065, and the diameter of the ablation balloon 2065 is close to the diameter of the delineation balloon 2064. During use, the delineating balloon 2064 is filled with water or air and the ablation balloon 2066 is filled with steam so that the ablation balloon 2065 contacts the delineating balloon 2064 and the delineating balloon 2064 contacts the target cardiac tissue near the equator of the two balloons 2064, 2065. This forms a hot area or ablation area 2067 near the equator of the delineating balloon 2064. A cold area 2071 is located on the delineating balloon 2064 where the filled ablation balloon 2065 does not contact the filled delineating balloon 2064. Heat is transferred from the ablation balloon 2065 through the delineating balloon 2064 and into the cardiac tissue to ablate the tissue and treat the arrhythmia.

[0295] Fig.20E A depiction capsule 2064 is shown having Fig.20D The catheter 2060 depicts electrode 2066 . Fig.20F Shows Fig.20D 2060. The catheter 2060 includes a divided outer wall 2068, which includes an air / water cavity 2062 and a wire 2069 for delineating electrodes. The catheter 2060 also includes a steam cavity 2063 and, in one embodiment, a guidewire lumen 2070. Figure 20G Shows Fig.20D 2060. The catheter 2060 includes a plurality of delineation electrodes 2066 disposed in the outer wall, or in one embodiment, disposed in the wall of the delineation balloon, the steam chamber 2063, and the guidewire chamber 2070.

[0296] Fig. 20H It shows the use Fig.20DFlowchart of the steps involved in one embodiment of a method for ablating cardiac tissue using a catheter of a cardiac arrhythmia. In step 2072, a delineation balloon is filled to a first pressure (P1). In step 2073, an arrhythmia region is delineated using the delineation balloon. In step 2074, the ablation balloon is steam filled to a second pressure (P2) greater than P1 with or without air to contact the delineation balloon. In step 2075, a hot region is formed on the surface of the delineation balloon, wherein the ablation balloon contacts the delineation balloon, and wherein the delineation balloon contacts cardiac tissue to ablate the cardiac tissue, while a cold region exists at a location where the ablation balloon does not contact the delineation balloon. In step 2076, electrical activity is monitored during and after the ablation process to record complete ablation focused on the arrhythmia. Optionally, in step 2077, the delineation electrodes monitor the impedance and tissue temperature of the tissue to guide the ablation. Optionally, in step 2078, pacing is performed away from the balloon to check whether sufficient ablation has been performed.

[0297] Fig.20I A cardiac ablation catheter 2080 according to another embodiment of the present specification is shown. Fig. 20J Shows Fig.20I A cross-sectional view of a middle portion of the elongated body 2081 of the catheter 2080, and Figure 20K Shows that being Fig.20I A cardiac ablation procedure is performed using a cardiac ablation catheter 2080. Also see Figures 20I to 20K , the catheter 2080 includes an elongated body 2081, a proximal end, and a distal end, and an air / water chamber 2082 and a steam chamber 2083 are supplied through a port at its proximal end. The air / water chamber 2082 is in fluid communication with a delineation balloon 2084 attached to the distal end of the catheter 2080. The air / water chamber 2082 optionally includes multiple sub-channels or chambers (along the length of the elongated body 2081) to allow air / water to enter and exit the chamber 2082 at the proximal end of the catheter 2080. The delineation balloon 2084 includes a plurality of delineation electrodes 2086 in or attached to the outer surface of its wall. The delineation electrodes 2086 delineate multiple areas of cardiac tissue causing arrhythmias. The steam chamber 2083 is in fluid communication with an ablation balloon 2085 attached to the distal end of the catheter 2080, which is located in the delineation balloon 2084 and is freely movable coaxially therein to be positioned in a plurality of positions along the longitudinal axis 2088. According to an exemplary embodiment, the catheter 2080 shows the ablation balloon 2085 moving along the longitudinal axis 2088 from a first position 2089a to a second position 2089b.

[0298] Once both balloons 2084, 2085 are filled, the length of the delineation balloon 2084 (along the longitudinal axis 2088) is greater than the length of the ablation balloon 2085 (along the longitudinal axis 2088) and the diameter of the ablation balloon 2085 is close to the diameter of the delineation balloon 2084. During use, the delineation balloon 2084 is filled with water or air and the ablation balloon 2085 is filled with steam and placed in a first position 2089a (in the delineation balloon 2084) so ​​that the ablation balloon 2085 contacts the delineation balloon 2084 and the delineation balloon 2084 contacts the target cardiac tissue near the first position 2089a in the heart 2001 near the pulmonary vein 2002. This forms a hot area or ablation area 2087a near the first position 2089a. Heat is transferred from the ablation balloon 2085 through the delineation balloon 2084 and into the cardiac tissue to ablate the tissue at the first position 2089a. The ablation capsule 2085 is then moved to a second position 2089b (in the delineation capsule 2084) so ​​that the ablation capsule contacts the delineation capsule 2084 and the delineation capsule 2084 contacts the target cardiac tissue near the second position 2089b in the pulmonary vein 2002. This forms a hot region or ablation region 2087b near the second position 2089b. Heat is transferred from the ablation capsule 2085 through the delineation capsule 2084 and into the cardiac tissue to ablate the tissue at the second position 2089b. A cold region 2090 is located on the delineation capsule 2084 where the filled ablation capsule 2085 does not contact the filled delineation capsule 2084. It should be understood that the delineation capsule 2084 and the ablation capsule 2085 may need to be filled differently at the first and second positions 2089a, 2089b in order to conform to the space in the pulmonary vein 2002 (associated with the first and second positions 2089a, 2089b).

[0299] According to one aspect, the delineation balloon 2084 is more flexible (compared to the ablation balloon 2085) and can be free-form or can be adapted to conform to anatomy (e.g., the lumen of the pulmonary vein 2002) in order to form sufficient contact for electrical contact between the electrode 2086 and the cardiac tissue. The ablation balloon 2085 is more stable and is used to apply stable contact at its axial contact points with the target tissue (e.g., points corresponding to the first and second locations 2089a, 2089b) for ideal delivery of thermal energy to the target cardiac tissue.

[0300] Figure 20L It shows the use Fig.20IFlowchart of steps involved in one embodiment of a method for ablating cardiac tissue using a catheter of a catheter. In step 2010, a delineation balloon is filled with air to a first pressure (P1). In step 2011, first and second locations corresponding to first and second arrhythmia regions are delineated using the delineation balloon. In step 2012, the ablation balloon is filled with steam to a second pressure (P2) greater than or equal to P1 to contact the delineation balloon at the first location. According to one embodiment, the air circulating into the delineation balloon is maintained at a temperature less than 60°C while maintaining the pressure in the delineation balloon at 0.1×P1 to 10×P2. In step 2013, a hot region is formed on the surface of the delineation balloon at the first location, wherein the ablation balloon contacts the delineation balloon, and wherein the ablation balloon contacts the delineation balloon, and wherein the delineation balloon contacts the first cardiac tissue to ablate the first cardiac tissue, while a cold region exists at a location where the ablation balloon does not contact the delineation balloon. In step 2014, electrical activity is monitored during and after the ablation process to record complete ablation focused on the first arrhythmia. Optionally, at step 2015, the delineation electrode monitors the impedance and tissue temperature of the tissue to guide ablation. Once ablation at the first location is complete, at step 2016, the ablation capsule is moved to form a hot area on the surface of the delineation capsule at a second location, wherein the ablation capsule has been moved to contact the delineation capsule, and wherein the delineation capsule contacts the second cardiac tissue, to ablate the second cardiac tissue. Steps 2014 and 2015 are repeated for the ablation process at the second location. It should be understood that in various embodiments, the ablation capsule may be moved to multiple locations and thereby form multiple hot areas on the surface of the delineation capsule to ablate cardiac tissue corresponding to the multiple locations.

[0301] Fig.21 A steam ablation catheter 2101 is shown introduced into the left atrium of a heart 2102 via a transseptal approach according to one embodiment of the present specification. In one embodiment, a flexible tipped guidewire (not shown) is introduced through the lumen of the steam ablation catheter 2101 and guided into the target pulmonary vein. A 20-40 mm steam ablation balloon is located at the end of the guidewire, which is then filled in the chamber of the left atrium and guided over the guidewire to the target pulmonary vein sinus. A depiction catheter 2103 is also introduced into this location to guide ablation.

[0302] Fig.22AA cardiac ablation catheter 2201 according to an embodiment of the present specification is shown. The catheter includes a handle 2204. The catheter 2201 includes an elongated body 2202, a proximal end, and a distal end having an air, water or saline chamber 2209 and a steam chamber 2206 supplied through a port at its proximal end. In some embodiments, air / water or preferably saline 2207 circulates in the saline chamber 2209 while steam 2208 is injected into the chamber 2206 to cool the body 2202. The distal end of the body 2202 has a distal attachment, such as a retractable needle 2205, which is in fluid communication with the steam chamber 2206. The retractable needle 2205 has at least one opening or injection port at its distal end for allowing steam 2208 to be discharged therefrom to ablate target cardiac tissue while the body 2202 is cooled by the saline 2207 circulating in the saline chamber 2209. In various embodiments, the catheter 2201 includes: a plurality of sensors at the distal end of the catheter 2201, such as electrical sensors, to monitor electrical activity during and after the ablation process and to measure tissue impedance to record complete ablation of the target cardiac tissue; a pressure sensor for measuring the pressure in the steam chamber 2206 and shutting off steam delivery when a predetermined critical pressure is reached; and a temperature sensor for monitoring tissue temperature to guide ablation.

[0303] It should be understood that the shape and size of the distal appendages vary in various embodiments to accommodate the specific anatomical features to be treated by ablation. Fig. 22B Another embodiment of a cardiac ablation catheter 2215 is shown in which the distal attachment is a retractable disc 2216 covered with an insulating film and attached to the distal end of the elongated body 2202. The catheter includes a handle 2204. During use, steam 2208 is delivered to the disc 2216 through the steam chamber 2206, while saline 2207 is circulated through the saline chamber 2209 to keep the outer surfaces of the elongated body 2202 and the disc 2216 cool. The steam 2208 is emitted from at least one injection port or opening at the distal surface of the retractable disc 2216 to ablate the target tissue. In various embodiments, the catheter 2215 includes: a plurality of sensors at the distal end of the catheter 2215, such as electrical sensors, to monitor electrical activity during and after the ablation process and to measure tissue impedance to record complete ablation of the target cardiac tissue; a pressure sensor for measuring the pressure in the steam chamber 2206 and shutting off steam delivery when a predetermined critical pressure is reached; and a temperature sensor for monitoring tissue temperature to guide ablation.

[0304] Fig. 22CYet another embodiment of a cardiac ablation catheter 2220 is shown, wherein at the distal end of the catheter 2220, the distal attachment includes an inner balloon 2222 in an outer balloon 2224. The catheter includes a handle 2204. The outer balloon 2224 is in fluid communication with a saline chamber 2209, and the inner balloon 2222 is in fluid communication with a steam chamber 2206. During use, the outer balloon 2224 is filled with saline 2207 (or alternatively, filled with air / water) such that the outer balloon 2224 contacts an ablation area including target tissue to be ablated. Steam 2208 enters the inner balloon 2222 to fill the inner balloon 2222 to contact the outer balloon 2224 near the ablation area. In various embodiments, the contact area between the inner balloon 2222 and the outer balloon 2224 is 5% to 95% and is located at the distal end or tip of the outer balloon 2224. In some embodiments, the inner balloon 2222 can move in the outer balloon 2224 and thus contact the outer balloon 2224 at different circumferential regions. A hot zone is formed at the contact region between the inner balloon 2222 and the outer balloon 2224 so that the heat energy from the inner balloon 2222 passes through the outer balloon 2224 to the ablation region near the distal end or tip of the outer balloon 2224. Some portions of the elongated body 2202 and the outer balloon 2224 (excluding the hot zone) are kept cool due to the circulating saline 2207. In various embodiments, the catheter 2220 includes: a plurality of sensors at the distal end of the catheter 2220, such as electrical sensors, to measure tissue impedance for delineating the target tissue, and to monitor electrical activity during and after the ablation process to record the complete ablation of the target tissue; a pressure sensor for measuring the pressure in the steam chamber 2206 and shutting off the steam delivery when a predetermined critical pressure is reached; and a temperature sensor for monitoring the temperature of the tissue to guide the ablation. It should be noted that in various embodiments, saline 2207 enters the saline lumen 2209 at the proximal end of the catheter and exits the proximal end of the catheter after circulating through the outer balloon 2224.

[0305] Fig.23 An embodiment of a cardiac ablation catheter 2301 is shown, according to an embodiment of the present specification, passing through the left atrium 2302 of the heart and into the pulmonary vein 2303. In one embodiment, the catheter is enclosed in a steerable outer sheath 2304. At the distal end of the catheter is an outer balloon 2305 through which air circulates. Within the outer balloon is an inner balloon, which is filled with water vapor. It should be understood that the ablation area 2309 includes the tissue-sac interface. The catheter 2307 is depicted coupled to the balloon by the end 2308.

[0306] In various embodiments, ablation therapy provided by the steam ablation system of the present specification is provided to achieve the following therapeutic features for cardiac ablation: maintaining tissue temperature at 100°C or less; ablating cardiac tissue without damaging esophageal tissue; at least 10% of patients regain normal sinus rhythm for at least 1 week; at least 10% of patients maintain normal sinus rhythm for at least 1 week; a reduction of at least 5% in the number of atrial arrhythmia attacks relative to the number of atrial arrhythmia attacks before treatment; a reduction of at least 5% in the number of supraventricular arrhythmia attacks relative to the number of supraventricular arrhythmia attacks prior to treatment; a reduction of at least 5% in the number of ventricular arrhythmia attacks relative to the number of ventricular arrhythmia attacks prior to treatment; and an increase in esophageal temperature of less than 8°C at any time during or after treatment, or an esophageal temperature of less than 45°C at any time during or after treatment.

[0307] Fig.24 is a flow chart of the steps involved in one embodiment of a cardiac ablation method. The ablation device used is similar to that of reference Fig.23 In step 2401, a 10-40 mm steam ablation balloon is introduced into the left atrium via a transseptal approach. Next, in step 2402, a flexible tipped guidewire is introduced through the lumen of the steam ablation catheter and guided to the target pulmonary vein. In step 2403, the balloon is filled in the lumen of the left atrium and guided over the guidewire to the sinus of the target pulmonary vein. Next, in step 2404, steam at 95 to 105°C is pumped into the inner balloon and converted to water when it contacts the balloon surface due to the temperature change of the balloon / tissue / blood interface. This conversion of steam to water is an exothermic reaction that transfers heat to the tissue, causing the balloon / tissue interface to become very hot, for example, 60 to 100°C. The very hot temperature at the balloon / tissue interface forms irreversible damage to the pulmonary vein tissue, thereby ablating the tissue. In step 2405, air is circulated through the outer balloon, separating the outer balloon from the inner balloon except at the desired inner balloon tissue interface, without contacting the remaining surface of the inner balloon with surrounding tissue or blood.

[0308] Fig.25A A side cross-sectional view of one embodiment of a cardiac ablation catheter 2502 is shown, wherein the distal attachment includes an inner balloon 2504 located within an outer balloon 2503 at the distal end of the catheter 2502. A cooling fluid is circulated through the outer balloon 2503, while the inner balloon 2504 is filled with steam or water vapor. In one embodiment, the outer balloon 2503 is made of a harder material, such as PET, while the inner balloon 2504 is made of a more flexible material, such as latex.

[0309] At the proximal end 2502b of the catheter 2502 is a handle 2507 having a channel or cavity 2508 extending therethrough for carrying steam and cooling water. During operation, water vapor at a temperature of about 100-120°C is input from the Luer connector 2510 and delivered to the inner balloon 2504 via the catheter 2502. This allows the inner balloon 2504 to fill and contact the outer balloon 2503 near the ablation area. A hot zone 2509 is formed at the contact area between the inner balloon 2504 and the outer balloon 2503 so that heat energy from the inner balloon 2504 passes through the outer balloon 2503 to the ablation area. Portions of the elongated body and the outer balloon 2503 (excluding the hot zone 2509) are kept cool by the circulating water. As described above, a channel is provided in the catheter 2502 for carrying cooling fluid and steam. The cooling water enters the catheter 2502 from the tube 2511 at the proximal end of the catheter and circulates through the outer balloon 2503 before exiting from another tube 2512 at the proximal end of the catheter. A Luer connector 2513 is provided so that the cooling fluid is supplied from and exits from the tubes 2511 and 2512, respectively. In one embodiment, the Luer connector 2510 at the water vapor inlet is a pressure-resistant Luer lock. In one embodiment, the cooling fluid is water. In another embodiment, the cooling fluid is air.

[0310] In one embodiment, the length of the catheter 2502 between its distal end 2502a and the proximal end 2502b is about 1800 mm, with a margin of ±500 mm. In one embodiment, the outer balloon 2502 is substantially cylindrical with tapered ends, and the inner balloon 2504 is substantially spherical. In one embodiment, the total length of the outer balloon 2503 between its two ends is about 83 mm, while the length of the cylindrical portion is about 60 mm, with a margin of ±25 mm, and its width is about 24 mm, with a margin of ±15 mm. In one embodiment, the diameter of the inner balloon 2504 is about 25 mm, with a margin of ±15 mm.

[0311] Fig.25B A detailed inside view of a catheter 2502 having various lumens is shown. Fig.25B , the central lumen 2501 is used to bring steam into the inner capsule 2504. The first outer lumen 2514 is used to bring cooling water from the tube 2511 to the outer capsule 2503, and the second outer lumen 2515 of the catheter is used to bring cooling water back from the outer capsule and pass through the tube 2512. All lumens are enclosed in another tube or handle 2505 for reinforcement.

[0312] In one embodiment, the channel or lumen of the catheter 2502 is as Fig.25B The shown is designed with openings at appropriate locations to ensure proper flow of fluid - steam into the inner bladder and to ensure cooling water flows in and out of the outer bladder. Fig.25CThe flow mechanism for catheter 2502 is shown through inner balloon 2504 and outer balloon 2503. Fig.25C , cross-sectional views of the catheter lumen at locations 2520, 2530, and 2540 are shown as 2521, 2531, and 2541. Details of the cross-sectional views can be seen at 2522, 2532, and 2542. As shown at 2522, there is an opening 2522a in the tube to allow cooling water to enter the channel from the outer balloon. The cooling water is carried away by the lumen ( Fig.25B As shown in 2542, there is an opening 2542a in the tube to allow cooling water leaving the channel to enter. The cooling water passes through the tube 2511 (as shown in Fig.25B ) is supplied and brought into the outer capsule by the channel. At 2532, two openings 2532a and 2532b can be seen in the channel, and steam is supplied from the central cavity 2532c to the inner capsule through the openings.

[0313] Fig.26A The inner bag (eg, Fig.25A , 25B and 25C 2504) side section 2601 and perspective view 2602. See Fig.26A In one embodiment, the balloon 2603 in its unexpanded form has a generally cylindrical shape and tapers at both ends 2604 and 2605. The ends extend into tubular structures 2606 and 2607, which help keep the catheter in place as it passes through the balloon. Fig.25A 2609 is about 5.6 mm wide at the widest portion of the balloon 2609, with a margin of ±2.5 mm.

[0314] Fig.26B The inner capsule (eg, Fig.25A , 25B and 25C 2504) side cross-sectional view 2611 and perspective view 2612. See Fig.26B In one embodiment, the balloon 2613 in its expanded form has the shape of a narrow elongated spheroid. Tubular structures 2616 and 2617 extend from opposite sides of the balloon, which help to keep the catheter in place as it passes through the balloon. Fig.25AIn one embodiment, the total length of the balloon in the expanded state (including tubular segments 2616, 2617) is about 28 mm, with a margin of ±15 mm, and the length of each tubular segment is about 4.8 mm, with a margin of ±2.0 mm. In one embodiment, when the balloon 2613 is in the expanded state, the inner diameter of each tubular segment is about 2.9 mm, and the outer diameter is 3.3 mm, with a margin of ±2.0 mm. In one embodiment, when the balloon is filled, the length of the main axis 2619 of the narrow elongated spheroid-shaped balloon is about 23.8 mm, with a margin of ±15 mm.

[0315] Fig. 27 A side cross-sectional view 2701 and a perspective view 2702 of the outer balloon in an expanded state are shown (eg, Fig.25A , 25B and 2503 of 25C). See Fig. 27 In one embodiment, the balloon 2703 has a generally cylindrical shape with two tapered ends 2704 and 2705. The ends extend into tubular structures 2706 and 2707, which help keep the catheter in place as it passes through the outer balloon. Fig.25A In one embodiment, the total length of the bladder including the tubular structures 2706, 2707 is about 113 ± 35 mm, while the length of the cylindrical portion 2709 is about 60 ± 25 mm. The length of each tubular segment 2706, 2707 is about 15 mm, with a margin of ± 15 mm, while the length of the tapered portion 2708 is 12 mm on each side, with a margin of ± 10 mm. In one embodiment, the diameter of each tubular segment is about 3 mm. The width of the cylindrical portion of the bladder 2709 is about 24 mm, with a margin of ± 15 mm, and the thickness of the bladder material is about 0.10 mm.

[0316] Fig.28 A pressure-resistant Luer lock 2800 (eg, Fig.25A 2510) of the side view 2801, the side cross-sectional view 2802 and the perspective view 2803. Fig.28 In one embodiment, the Luer lock 2803 includes a central grip 2804 for operating the lock 2803, a male connector 2803 at its distal end 2809, and a female connector 2806 at its proximal end 2810. The male connector 2803 includes a tapered end 2808 and is configured to be securely attached to the Fig.25AThe proximal end of the handle 2507 in the conduit is formed to form a Luer lock for steam entry in the catheter. The female connector 2806 includes an opening 2811 for receiving a tube of a steam source and a groove 2807 for fixing the steam source tube. The grip 2804 is used to operate the lock 2800 when the lock is attached to the steam source. In one embodiment, the total length of the lock 2800 is about 21.9mm. At the female connector 2806, the outer diameter is about 7.5mm, and the inner diameter is about 4.2mm. In one embodiment, the width of the female connector 2806 is about 4mm. In one embodiment, a groove 2807 is etched on the female connector 2806, which has a uniform width of about 0.6mm. The diameter of the male connector 2803 is about 4mm before it becomes conical, and the diameter is reduced to 3.3mm at the distal end 2809. In one embodiment, the lock 2800 has a standard taper of 6%.

[0317] In one embodiment, the grip 2804 of the Luer lock 2800 has a width of approximately 7 mm and a diameter of approximately 11 mm.

[0318] Endometrial ablation

[0319] Fig.29AEndometrial ablation performed in a female uterus using an ablation device according to an embodiment of the present specification is shown. A cross section of a female reproductive tract including a vagina 2970, a cervix 2971, a uterus 2972, an endometrium 2973, a fallopian tube 2974, an ovary 2975, and a uterine fundus 2976 is shown. A catheter 2977 of the ablation device is inserted into the uterus 2972 ​​through the cervix 2971 at the cervical os. In one embodiment, the catheter 2977 has two positioning elements, a conical positioning element 2978 and a disc-shaped positioning element 2979. The positioning element 2978 is conical and has an insulating film covering the conical positioning element 2978. The conical element 2978 positions the catheter 2977 in the center of the cervix 2971 and the insulating film prevents heat or ablative agents from escaping the cervix 2971 through the cervical os 2971o. A second disc-shaped positioning element 2979 is deployed near the fundus 2976 to position the catheter 2977 in the middle of the cavity. The ablative agent 2978a passes through the injection port 2977a for uniform delivery of the ablative agent 2977a into the uterine cavity. The predetermined length 'l' of the ablation segment of the catheter and the diameter 'd' of the positioning element 2979 allow for estimation of the cavity size and for calculation of the thermal energy required to ablate the endometrial lining. In one embodiment, the positioning elements 2978, 2979 are also used to move endometrial tissue away from the injection port 2977a on the catheter 2977 to allow delivery of the ablative agent. An optional temperature sensor 2907 deployed near the endometrial surface is used to control the delivery of the ablative agent 2978a. An optional morphological depiction device using multiple infrared, electromagnetic, acoustic or radio frequency energy transmitters and sensors can be used to define the size and shape of the cavity in a patient with an irregular or deformed uterine cavity due to some conditions (e.g., uterine fibroids). Additionally, data from diagnostic testing may be used to determine the size, shape, or other characteristics of the uterine cavity.

[0320] In one embodiment, the ablative agent is a vapor that contracts when cooled. The vapor turns to water, which has a smaller volume than a cryogen, which will expand, or than a hot fluid used in hydrothermal ablation, where the volume of the hot fluid remains constant. In the case of cryogens and hot fluids, increased energy delivery is associated with an increased volume of the ablative agent, which in turn requires a mechanism for removing the agent, otherwise the medical provider will face complications, such as perforation. However, vapor turns to water when cooled, which occupies much less space; therefore, increased energy delivery is not associated with an increase in the remaining volume of the ablative agent, thereby eliminating the need for continued removal. This further reduces the risk of thermal energy leaking through the fallopian tubes 2974 or the cervix 2971, thereby reducing any risk of thermal damage to adjacent healthy tissue.

[0321] In one embodiment, the positioning attachment must be separated from the ablation zone by a distance greater than 0.1 mm (preferably 1 mm and more preferably 1 cm). In another embodiment, the positioning attachment can be in the ablation zone as long as it does not cover a large amount of surface area. For endometrial ablation, it is not necessary to ablate 100% of the tissue to achieve the desired treatment effect.

[0322] In one embodiment, the preferred distal positioning attachment is a bare screen that is positioned proximal to the mid-body region. In one embodiment, the preferred proximal positioning device is a covered screen that is pulled into the cervix to center the device and seal off the cervix. One or more such positioning devices can help compensate for variations in anatomical structures in the uterus. The proximal positioning device is preferably oval, with a major axis of 0.1 mm to 10 cm (preferably 1 cm to 5 cm) and a minor axis of 0.1 mm to 5 cm (preferably 0.5 cm to 1 cm). The distal positioning device is preferably circular, with a diameter of 0.1 mm to 10 cm, preferably 1 cm to 5 cm.

[0323] In another embodiment, the catheter is a coaxial catheter comprising an outer catheter and an inner catheter, wherein upon insertion, the distal end of the outer catheter engages the cervix and stops at the cervix, while the inner catheter extends into the uterus until its distal end contacts the fundus of the uterus. The length of the inner catheter that has entered the uterus is then used to measure the depth of the uterine cavity and determine the ablative dose to be used. The ablative agent is then delivered to the uterine cavity via at least one port on the inner catheter. In one embodiment, the intracavitary pressure in the uterus is maintained below 100 mm Hg during treatment. In one embodiment, the coaxial catheter further comprises a pressure sensor to measure the intracavitary pressure. In one embodiment, the coaxial catheter further comprises a temperature sensor to measure the intracavitary temperature. In one embodiment, the ablative agent is steam and the steam is released from the catheter at a pressure of less than 100 mm Hg. In one embodiment, steam at a temperature of 90 to 100° C. is delivered.

[0324] Fig.29B2 is a schematic diagram of a coaxial catheter 2920 for use in ablation of endometrial tissue according to one embodiment of the present specification. The coaxial catheter 2920 includes an inner catheter 2921 and an outer catheter 2922. In one embodiment, the inner catheter 2921 has one or more ports 2923 for delivering an ablative agent 2924. In one embodiment, the ablative agent is steam. In one embodiment, the outer catheter 2922 has a plurality of fins 2925 to engage the cervix to prevent steam from escaping from the uterus and entering the vagina. In one embodiment, the fins include silicone. In one embodiment, the outer catheter 2922 includes a Luer lock 2926 to prevent steam from escaping between the inner catheter 2921 and the outer catheter 2922. In one embodiment, the inner catheter 2921 includes a measurement mark 2927 to measure the depth of insertion of the inner catheter 2921 beyond the end of the outer catheter 2922. Optionally, in various embodiments, one or more sensors 2928 are incorporated into the inner catheter 2921 to measure intracavitary pressure or temperature.

[0325] Fig.29C is a flow chart according to one embodiment of the present specification, which lists the steps involved in performing an endometrial tissue ablation procedure using a coaxial ablation catheter. In step 2902, the coaxial catheter is inserted into the patient's vagina and advanced to the cervix. Subsequently, in step 2904, the coaxial catheter is advanced so that the fins of the outer catheter engage the cervix, effectively stopping the advancement of the outer catheter at that point. In step 2906, the inner catheter is then advanced until the distal end of the inner catheter contacts the fundus of the uterus. In step 2908, the insertion depth is then measured using the measurement markings on the inner catheter, thereby determining the amount of ablative agent to be used in the procedure. In step 2910, the Luer lock is tightened to prevent any escape of steam between the two catheters. In step 2912, steam is then delivered through the lumen of the inner catheter and into the uterus via the delivery port on the inner catheter to ablate the endometrial tissue.

[0326] Fig.29D2 is a schematic diagram of a bifurcated coaxial catheter 2930 for use in ablation of endometrial tissue according to one embodiment of the present specification. The catheter 2930 includes a first elongated shaft 2932 having a proximal end, a distal end, and a first lumen therein. The first lumen is split at the distal end to form a coaxial shaft 2933. The distal end of the first shaft 2932 also includes a first positioning element or cervical plug 2934, which seals the patient's cervix. The catheter 2930 bifurcates as it extends distally from the cervical plug 2934 to form a second catheter shaft 2935 and a third catheter shaft 2936. The second and third catheter shafts 2935, 2936 each include a proximal end, a distal end, and a shaft body having one or more vapor delivery ports 2937. The second and third catheter shafts 2935, 2936 include second and third lumens, respectively, for delivering an ablative agent. The distal ends of the second and third catheter shafts 2935, 2936 include second and third positioning elements or tubal plugs 2938, 2939, respectively, which are designed to engage the patient's fallopian tubes during the ablation treatment process and prevent the escape of ablative energy. The tubal plugs 2938, 2939 are also used to position the second and third axes 2935, 2936, respectively, in the intramural portion or isthmus of the patient's fallopian tubes. The second and third catheter shafts 2935, 2936 can extend independently coaxially and the length of each axis 2935, 2936 is used to determine the size of the patient's endometrial cavity. The ablative agent 2940 travels through the first catheter shaft 2932, through the second and third catheter shafts 2935, 2936, and leaves the vapor delivery port 2937 and enters the endometrial cavity to ablate endometrial tissue.

[0327] Fig.29E is a flowchart according to an embodiment of the present specification, which lists the use of Fig.29D Method steps for ablating endometrial tissue using an ablation catheter. In step 2943, a coaxial catheter is inserted into the patient's uterus and the cervix engages a cervical plug. In step 2944, the catheter is then advanced until each tubal plug is proximate to the ostium of the fallopian tube. In step 2945, each fallopian tube is then engaged with a tubal plug and the size of the endometrial cavity is measured. The measurement is made based on the length of each catheter shaft that has been advanced. In step 2946, the measured size is used to calculate the ablation dose required to perform the ablation. In step 2947, the calculated dose of ablative agent is then delivered through the catheter shaft and into the endometrial cavity to achieve the desired endometrial ablation.

[0328] Fig.29F is a schematic diagram of a bifurcated coaxial catheter 2950 having expandable elements 2951, 2953 for use in ablation of endometrial tissue according to one embodiment of the present specification. Fig.29D The catheter 2930, Fig.29FThe catheter 2950 shown includes a first elongated concentric shaft 2952 having a proximal end, a distal end, and a first lumen therein. The first lumen is split in the distal end to form the concentric shaft 2949. The distal end of the first shaft 2952 also includes a first positioning element or cervical plug 2954, which seals the patient's cervix. The catheter 2950 bifurcates as it extends distally from the cervical plug 2954 to form a second catheter shaft 2955 and a third catheter shaft 2956. The second and third catheter shafts 2955, 2956 each include a proximal end, a distal end, and a catheter shaft body having one or more steam delivery ports 2957. The second and third catheter shafts 2955, 2956 include second and third lumens, respectively, for delivering an ablative agent. The distal ends of the second and third catheter shafts 2955, 2956 include second and third positioning elements or tubal plugs 2958, 2959, respectively, which are designed to engage the patient's fallopian tubes during the ablation treatment process and prevent the escape of ablative energy. The tubal plugs 2958, 2959 are also used to position the second and third shafts 2955, 2956, respectively, in the intramural portion or isthmus of the patient's fallopian tubes. The second and third catheter shafts 2955, 2956 can extend independently and coaxially and the length of each catheter shaft 2955, 2956 is used to determine the size of the patient's endometrial cavity.

[0329] The catheter 2950 further includes a first expandable member or balloon 2951 and a second expandable member or balloon 2953 having a coaxial balloon structure. In one embodiment, the first balloon 2951 is a compliant balloon structure and the second balloon 2953 is a non-compliant balloon structure that is shaped to approximate the shape, size or volume of the uterine cavity. In another embodiment, the second balloon 2953 is partially compliant. In another embodiment, in another embodiment, the two balloons 2951, 2953 are substantially identical. The balloons 2951, 2953 are attached to the second and third catheter shafts 2955, 2956 along the inner surface of each shaft 2955, 2956. The first balloon or inner balloon 2951 is positioned in the second balloon or outer balloon 2953. The inner balloon 2951 is designed to be filled with air and the first volume of the inner balloon 2951 is used to measure the size of the patient's endometrial cavity. Ablative agent 2961 is introduced into catheter 2950 at the proximal end of the catheter and travels through first catheter shaft 2952 and into second and third catheter shafts 2955, 2956. Second and third catheter shafts 2955, 2956 are designed to release ablative energy 2962 through delivery port 2957 and into space 2960 between two balloons 2951, 2953. Some ablative energy 2963 is transmitted to the air in inner balloon 2951, causing its volume to expand from the first volume to the second volume, achieving further expansion of the inner balloon 2951 to further seal the patient's endometrial cavity for ideal steam delivery. In one embodiment, the second volume is less than 125% of the first volume. The expansion also forces the tubal plugs 2958, 2959 to further engage the fallopian tube ostium. A portion of the ablative agent or ablative energy 2964 diffuses out of the heat-permeable outer balloon 2953 and into the endometrial cavity, ablating endometrial tissue. In various embodiments, heating of the air in the balloon occurs through the wall of the inner balloon or through the length of the catheter or both. In one embodiment, the catheter 2950 includes an optional fourth catheter shaft 2965 extending from the first catheter shaft 2952 in the inner balloon 2951 and between the second and third catheter shafts 2955, 2956. Heat energy from the fourth catheter shaft 2965 is used to further expand the inner balloon 2951 and aid in ablation.

[0330] In one embodiment, the volume of the inner balloon 2951 is used to control the pressure applied to the uterine wall by the outer balloon 2953. The pressure in the inner balloon 2951 is monitored and air is added or removed from the inner balloon 2951 to achieve the desired therapeutic pressure in the outer balloon 2953.

[0331] Figure 29G According to one embodiment of the present specification, the endometrial tissue 2967 is ablated by inserting the endometrial cavity 2966 into the patient's uterine cavity 2966 for ablation. Fig.29FSchematic diagram of a catheter 2950. The catheter 2950 has been inserted with a first shaft 2952 extending through a patient's cervix 2968 such that a second shaft 2955 is positioned along a first side of the patient's uterine cavity 2966 and a third shaft 2956 is positioned along a second side opposite to the first side. This positioning deploys an inner capsule 2951 and an outer capsule 2953 between the second and third shafts 2955, 2956. In the illustrated embodiment, the catheter 2950 includes an optional fourth shaft 2965 to further expand the inner capsule 2951 and assist in ablation of endometrial tissue 2967 through thermal energy. In one embodiment, the inner capsule 2951 is optional and the outer capsule 2953 performs the function of sizing and delivering the ablative agent. In one embodiment, the outer capsule includes a thermosensitive hole 2969 that is closed at room temperature and opens at a temperature higher than body temperature. In one embodiment, the hole includes a shape memory alloy (SMA). In one embodiment, the SMA is nitinol. In one embodiment, the SMA has an austenite finish (Af) temperature, or the temperature at which the transformation from martensite to austenite is completed upon heating (the alloy undergoes a shape change to become an open pore 2969), greater than 37° C. In other embodiments, the SMA has an Af temperature greater than 50° C. but less than 100° C.

[0332] Fig.29H is a flowchart according to an embodiment of the present specification, which lists the use of Fig.29F Method steps for ablating endometrial tissue using an ablation catheter. In step 2980, a coaxial catheter is inserted into the patient's uterus and the cervix engages a cervical plug. In step 2981, the catheter is then advanced until each tubal plug is proximal to the tubal ostium. In step 2982, each fallopian tube is then engaged with a tubal plug, which also deploys a coaxial balloon in the endometrial cavity and measures the size of the endometrial cavity. The measurement is based on the length of each catheter shaft that has been advanced and the first volume required to expand the balloon to a predetermined pressure. In step 2983, the balloon is filled to the predetermined pressure and the volume of the endometrial cavity is calculated using the first volume of the balloon at the pressure. In step 2984, the ablation dose required to perform the ablation is calculated using the measured size. In step 2985, the calculated dose of ablative agent is then delivered through the catheter shaft and into the space between the coaxial balloons. Some ablative energy is delivered to the inner balloon to expand the inner balloon to a second volume, which further expands the endometrial cavity and optionally pushes the tubal plug further into the tubal ostium to prevent thermal energy from escaping. Another portion of ablative energy is delivered to the diathermy outer balloon to achieve desired endometrial ablation.

[0333] In another embodiment, a steam ablation device for ablation of endometrial tissue includes a catheter designed to be inserted through the cervical os and into the endometrial cavity, wherein the catheter is connected to a steam generator for generating steam and includes at least one port positioned in the endometrial cavity to deliver steam into the endometrial cavity. The steam is delivered through the port and causes the air in the endometrial cavity to heat and expand to maintain the endometrial cavity pressure below 200 mm Hg and ideally below 50 mm Hg. In one embodiment, an optional pressure sensor measures the pressure and maintains the intracavitary pressure at a desired therapeutic level, wherein the endometrial cavity is preferably expanded to allow for even distribution of ablation energy without the risk of ablation energy leaking significantly outside the endometrial cavity and damaging adjacent normal tissue.

[0334] Fig.29I is a schematic diagram of a bifurcated coaxial catheter 2970 for use in ablation of endometrial tissue according to another embodiment of the present specification. Forming a seal at the cervix is ​​undesirable because it forms a closed cavity, causing a pressure increase when steam is delivered to the uterus. This increases the temperature of the air in the uterus, causing thermal expansion and further increasing the pressure in the cavity. This pressure increase can force the steam or hot air to escape out of the fallopian tubes, causing thermal damage to the abdominal viscera. This requires continuous measurement of the intracavitary pressure and active removal of the ablative agent to prevent thermal energy from leaking out of the cavity. See Fig.29I , catheter 2970 includes a coaxial handle 2971, a first positioning element 2972, a first bifurcated catheter arm 2935i with a second positioning element 2938i at its distal end, a second bifurcated catheter arm 2936i with a third positioning element 2939i at its distal end, and a plurality of injection ports 2937i along each bifurcated catheter arm 2935i, 2936i. Catheter 2970 also includes a vent 2976, which extends through the coaxial handle 2971 and through the first positioning element 2972, so that the cavity of the patient's uterus is communicated with the patient's external fluid when the first positioning element 2972 ​​is positioned against the cervix. This prevents the formation of a tight seal when catheter 2970 is inserted into the cervix. Because the cervix is ​​usually in a closed position, the insertion of any device will disadvantageously form an undesirable seal. The vent allows heated air or additional steam 2940i to be discharged when it expands with the delivery of steam and the pressure in the cavity increases. In some embodiments, the vent includes a valve for one-way air flow.

[0335] Fig.29J2 is a schematic diagram of a bifurcated coaxial catheter 2973 for use in ablation of endometrial tissue according to yet another embodiment of the present specification. The catheter 2973 includes a coaxial handle 2974, a first positioning element 2975, a first bifurcated catheter arm 2935j having a second positioning element 2938j at its distal end, a second bifurcated catheter arm 2936j having a third positioning element 2939j at its distal end, and a plurality of injection ports 2937j along each bifurcated catheter arm 2935j, 2936j. The catheter 2973 also includes two vents 2991, 2992 that extend through the coaxial handle 2974 and through the first positioning element 2975 so that the cavity of the patient's uterus is in fluid communication with the patient's body when the first positioning element 2975 is positioned against the cervix. This prevents the formation of a tight seal when the catheter 2973 is inserted into the cervix. The vents 2991, 2992 allow heated air or additional steam 2940j to escape as it expands with the delivery of steam and the pressure in the cavity increases. In some embodiments, the vents 2991, 2992 include valves for one-way air flow.

[0336] Figure 29K 2 is a schematic diagram of a water-cooled catheter 2900k for use in endometrial tissue ablation according to one embodiment of the present specification. The catheter 2900k includes an elongated body 2901k having a proximal end and a distal end. The distal end includes a plurality of ports 2905k for delivering steam 2907k for tissue ablation. A sheath 2902k extends along the body 2901k of the catheter 2900k to a point near the port 2905k. During use, water 2903k circulates through the sheath 2902k to cool the catheter 2900k. Steam 2907k for ablation and water 2903k for cooling are supplied to the catheter 2900k at the proximal end of the catheter.

[0337] Figure 29L2 is a schematic diagram of a water-cooled catheter 29001 for ablation of endometrial tissue and positioned in a patient's uterus 29071 according to another embodiment of the present specification. The catheter 29001 includes an elongated body 29011, a proximal end, a distal end, and a sheath 29021 covering the proximal portion of the body 29011. The sheath 29021 extends from and is in fluid communication with a cervical cup 29041. The catheter 29001 further includes a plurality of ports 29061 at its distal end, which are configured to deliver ablative steam 29081 to the uterus 29071. Steam 29081 is supplied to the proximal end of the catheter 29001. The port 29061 is positioned on the catheter body 29011 away from the sheath 29021. The cervical cup 29041 is configured to cover the cervix 29091 and the distal end of the sheath 29021 extends into the cervical canal 29101. Water 29031 is circulated through the sheath 29021 and cervical cup 29041 to cool the cervical canal 29101 and / or cervix 29091, while steam 29081 is delivered through the steam delivery port 29061 to ablate the endometrial lining 29111.

[0338] In various embodiments, the ablation therapy provided by the steam ablation system of the present specification achieves the following therapeutic features for uterine ablation: maintaining tissue temperature at 100°C or less; increasing the patient's hemoglobin by at least 5% or at least 1 gm% relative to pre-treatment hemoglobin; reducing menstrual blood flow by at least 5% relative to pre-treatment menstrual blood flow, as measured by menstrual pad weight; ablating endometrial tissue in the range of 10% to 99%; reducing the duration of menstruation by at least 5% relative to pre-treatment menstruation; reducing the amenorrhea rate by at least 10% relative to the pre-treatment amenorrhea rate; and patient-reported satisfaction with the uterine ablation procedure greater than 25%.

[0339] Fig.29M is a water-cooled catheter 2900m used in cervical ablation according to one embodiment of the present specification, Fig.29N is located in the patient's cervix 2909n Fig.29M Schematic diagram of the duct 2900m. See also Fig.29M and 29N, the catheter 2900m includes an elongated body 2901m, a proximal end, a distal end, and a water-cooled tip 2902m at its distal end. A cervical cup 2914m is attached to the catheter body 2901m and includes a plurality of ports 2906m in fluid communication with the proximal end of the catheter 2900m. Steam 2908m is provided at the proximal end of the catheter 2900m and is delivered to the cervix 2909n via the ports 2906m. In one embodiment, the steam 2908m ablates a lesion area 2912n at the cervix 2909n. The water-cooled tip 2902m of the catheter 2900m cools the cervical canal 2910n during ablation.

[0340] Fig.29O is used Fig.29M FIG2900 is a flow chart of the steps involved in performing cervical ablation with a catheter of FIG2901. At step 2902o, the distal tip of the catheter is inserted into the cervical canal until the cervical cup of the catheter surrounds the cervix. At step 2904o, water is circulated through the water cooling tip to cool the cervical canal. At step 2906o, steam is passed through a steam delivery port in the cervical cup to ablate the cervix.

[0341] In various embodiments, ablation therapy provided by the steam ablation system of the present specification is provided to achieve the following therapeutic features for cervical ablation: maintaining tissue temperature at 100°C or less; ablating the cervical mucosa without significantly damaging the cervical canal; ablating at least 50% of the surface area of ​​the target abnormal cervical mucosa so that upon recovery, the abnormal cervical mucosa is replaced by normal cervical mucosa; eliminating 25% more abnormal cervical mucosa compared to colposcopic intervention; and ablating more than 25% of the abnormal cervical mucosa and less than 25% of the total length of the cervical canal.

[0342] Fig. 30A FIG. 2 shows a flow chart of a method for ablating endometrial tissue according to an embodiment of the present specification. Fig. 30A, a first step 3001 includes inserting a catheter of an ablation device through the cervix and into the uterus of a patient, wherein the catheter includes a hollow shaft (through which an ablative agent can travel), at least one first positioning element, at least one second positioning element positioned distal to the at least one first positioning element, and at least one injection port for delivering the ablative agent. In one embodiment, the ablation device includes a controller including a microprocessor for controlling the delivery of the ablative agent. The catheter is passed through the cervix so that the first positioning element is positioned in the cervix and the second positioning element is positioned in the uterine cavity. In one embodiment, the second positioning element is positioned proximate to the fundus of the uterus. In step 3002, the two positioning elements are deployed so that the first positioning element contacts the cervix, the second positioning element contacts a portion of the uterine cavity, and the catheter and the injection port are positioned in the uterine cavity of the patient. Finally, in step 3005, the ablative agent is delivered through the injection port to ablate endometrial tissue.

[0343] Optionally, a sensor is used to measure at least one dimension of the uterine cavity at step 3003 and the measurement is used to determine, at step 3004, an ablation dose to be delivered.

[0344] Fig. 30B is a flow chart showing a method for ablating uterine fibroids. Fig. 30B , a first step 3011 includes inserting a hysteroscope through the cervix and into the patient's uterus. Next, in step 3012, a catheter of an ablation device is passed through the hysteroscope, wherein the catheter includes a hollow shaft (through which an ablative agent can travel), a puncture tip at its distal end, at least one positioning element, and a plurality of needles, the plurality of needles being on the distal end of the catheter and configured to deliver an ablative agent to the uterine fibroid. In one embodiment, the ablation device includes a controller, the controller including a microprocessor for controlling the delivery of the ablative agent. The catheter is passed through the hysteroscope so that the puncture tip of the catheter punctures the uterine fibroid. In the next step 3013, at least one positioning element is deployed to position the catheter in the uterine fibroid so that the plurality of needles on the distal end of the catheter are positioned in the uterine fibroid. Finally, in step 3014, an ablative agent is delivered through the needle to ablate the fibroid.

[0345] prostate

[0346] Fig.31A is a schematic diagram of a water cooling pipe 3100 according to another embodiment of the present specification. Fig.31B is a cross section of the distal end of the catheter 3100. Now see Fig.31A and 31B, the catheter 3100 includes an elongated body 3105 having a proximal end and a distal end. The distal end includes a positioning element 3125, such as an inflatable balloon. A plurality of openings 3115 are located near the distal end for allowing a plurality of associated thermally conductive electrical elements 3116 (e.g., needles) to extend through the plurality of openings 3115 (extending from the catheter 3100 at an angle, wherein the angle ranges from 30 to 90 degrees) and be deployed or retracted. According to one aspect, the plurality of retractable needles 3116 are hollow and include at least one opening to allow ablative agents, such as steam 3117, to be delivered through the needles 3116 when the needles 3116 extend through the plurality of openings 3115 and are deployed. The sheath 3110 extends along the body 3105 of the catheter 3100 (which includes the plurality of openings 3115) to the distal end. The plurality of openings 3115 extend from the body 3105 and through the sheath 3110, such that the plurality of needles 3116 extend beyond the sheath 3110 when deployed. During use, a cooling fluid such as water or air 3120 is circulated through the sheath 3110 to cool the catheter 3100. Steam 3117 for ablation and cooling fluid 3120 for cooling are supplied to the catheter 3100 at the proximal end of the catheter.

[0347] It should be noted that an alternative embodiment may include two positioning elements or balloons - one at the distal end and another proximal to the opening 3115, such that the opening 3115 is located between the two balloons.

[0348] Fig.32A According to an embodiment of the present specification, a method of using a catheter (e.g. Fig.31A FIG. 3 shows a prostate ablation performed on an enlarged prostate in the male urinary system by a catheter 3100 (with two positioning elements). A cross section of a male urogenital tract with an enlarged prostate 3201, a bladder 3202, and a urethra 3203 is shown. The urethra 3203 is squeezed by the enlarged prostate 3201. An ablation catheter 3205 passes through a cystoscope 3204 positioned in the urethra 3203 away from the obstructed portion. The positioning element 3206 is deployed to position the center of the catheter in the urethra 3203 and one or more insulating needles 3207 pass through and penetrate the prostate 3201. A vapor ablative agent 3208 passes through the insulating needle 3207, thereby ablating the diseased prostate tissue and achieving prostate shrinkage.

[0349] The size of the enlarged prostate can be calculated by using the difference between the extra-prostatic and intra-prostatic urethra. Standard values ​​can be used as a baseline. Additional ports for injecting cooling fluid into the urethra can be provided to prevent damage to the urethra when ablative energy is delivered to the prostate for ablation, thereby preventing complications such as stricture formation.

[0350] In one embodiment, the positioning attachment must be separated from the ablation area by a distance greater than 0.1 mm (preferably 1 mm to 5 mm and no greater than 2 cm). In another embodiment, the positioning attachment can be deployed in the bladder and pulled back into the urethral opening / bladder neck, thereby securing the catheter. In one embodiment, the positioning device is 0.1 mm to 10 cm in diameter.

[0351] Fig.32B A method of using an ablation device (e.g. Fig.31A Schematic diagram of transurethral prostate ablation performed on an enlarged prostate 3201 in the male urinary system using a catheter 3100 - having a positioning element. Fig.32B Also shown is a bladder 3202 and a prostatic urethra 3203. An ablation catheter 3223 having a handle 3220 and a positioning element 3228 is inserted into the urethra 3203 and advanced into the bladder 3202. The positioning element 3228 is filled and pulled to the junction of the bladder and the urethra, thereby positioning the needle 3207 to be a predetermined distance from the junction. Using a pusher 3230, the needle 3207 is then pushed out of the catheter 3223 through the urethra and into the prostate to reach 3201 at an angle of 30 to 90 degrees. Steam is controlled by port 3238, which travels through the axis of the catheter 3223 and leaves the opening 3237 in the needle 3207 and enters the prostatic tissue, thereby ablating the prostatic tissue. In one embodiment, the needle 3207 is thermally insulated. Optional port 3239 allows a cooling fluid with a temperature of <37°C to enter through opening 3240 to cool the prostatic urethra. An optional temperature sensor 3241 may be installed to detect the temperature of the prostatic urethra and adjust steam delivery.

[0352] Fig.32C FIG. 1 is a schematic diagram of transurethral prostate ablation performed on an enlarged prostate 3201 in the male urinary system using an ablation device according to another embodiment of the present specification. Fig.32CAlso shown is a bladder 3202 and a prostatic urethra 3203. An ablation catheter 3223 having a handle 3220 and a positioning element 3248 is inserted into the urethra 3203 and advanced into the bladder 3202. The positioning element 3248 is a compressible disc that expands in the bladder 3202 and is pulled to the junction of the bladder and the urethra, thereby positioning the needle 3207 at a predetermined distance from the junction. Using a pusher 3230, the needle 3207 is then pushed out of the catheter 3223 through the urethra and into the prostate to reach 3201 at an angle of 30 to 90 degrees. Steam is controlled by port 3238, which travels through the shaft of the catheter 3223 and exits through the opening 3237 in the needle 3207 and enters the prostatic tissue, thereby ablating the prostatic tissue. In one embodiment, the needle 3207 is thermally insulated. An optional port 3239 allows a cooling fluid with a temperature of <37°C to enter through the opening 3240 to cool the prostatic urethra. An optional temperature sensor 3241 may be installed to detect the temperature of the prostatic urethra and adjust steam delivery.

[0353] Fig.32D is a flow chart according to one embodiment of the present specification, which lists the steps involved in performing transurethral ablation of an enlarged prostate using an ablation catheter. In step 3212, the ablation catheter (e.g. Fig.31A The catheter 3100 of the embodiment of the present invention is inserted into the urethra and advanced until its distal end is in the bladder. In step 3214, a positioning element is then deployed on the distal end of the catheter, and the proximal end of the catheter is pulled so that the positioning element abuts the junction of the bladder and the urethra, thereby positioning the catheter shaft in the urethra. In step 3216, a pusher at the proximal end of the catheter is actuated to deploy a needle from the catheter shaft, through the urethra and into the prostate tissue. In step 3218, an ablative agent is delivered through the needle and into the prostate to ablate the target prostate tissue.

[0354] Fig.32E is a schematic diagram of transrectal prostate ablation performed on an enlarged prostate in the male urinary system using an ablation device according to one embodiment of the present specification. Fig.32E Also shown are a bladder 3202 and a prostatic urethra 3203. The ablation device includes a catheter 3223 having a needle tip 3224. An endoscope 3222 is inserted into the rectum 3221 for visualization of the enlarged prostate 3201. In various embodiments, the endoscope 3222 is an ultrasound endoscope or a transrectal ultrasound device so that the endoscope can be visualized using X-ray technology. A catheter 3223 having a needle tip 3224 is passed through a working channel of the endoscope and the needle tip 3224 is passed through the rectum into the prostate 3201. A close-up view of the distal end of the catheter 3223 and the needle tip 3204 is shown in FIG. Figure 32GThe ablative agent is then delivered through the needle tip 3224 and into the prostate tissue for ablation. In one embodiment, the catheter 3223 and the needle tip 3224 include insulating materials. In various embodiments, the needle tip 3224 is an ultrasound biopsy needle or an ultrasound transparent needle, which can be observed using radioactive techniques for accurate positioning in the prostate tissue. In one embodiment, an optional catheter (not shown) can be placed in the urethra to deliver a fluid to cool the prostatic urethra 3203. In one embodiment, the insertion fluid has a temperature of less than 37°C.

[0355] Fig.32F FIG. 4 is a schematic diagram of transrectal prostate ablation performed on an enlarged prostate in the male urinary system using a coaxial ablation device with a positioning element according to another embodiment of the present specification. Fig.32F Also shown are a bladder 3202 and a prostatic urethra 3203. The ablation device includes a coaxial catheter 3223 having an inner catheter and an outer catheter, the inner catheter having a needle tip 3224 and the outer catheter having a positioning element 3228. An endoscope 3222 is inserted into the rectum 3221 for visualization of the enlarged prostate 3201. In various embodiments, the endoscope 3222 is an ultrasound endoscope or a transrectal ultrasound device so that the endoscope can be visualized using X-ray technology. The coaxial catheter 3223 having the needle tip 3224 and the positioning element 3228 is passed through a working channel of the endoscope so that the positioning element 3228 abuts the rectal wall and the inner catheter is advanced through the rectum, thereby positioning the needle tip 3224 at a predetermined depth in the prostate 3201. A close-up view of the distal end of the catheter 3223 and the needle tip 3204 is shown in FIG. Figure 32G In one embodiment, the positioning element is a compressible disc having a first squeezed pre-use configuration and a second expanded deployed configuration once it is delivered beyond the distal end of the endoscope 3222. The ablative agent is then delivered through the needle tip 3224 and into the prostate tissue for ablation. In one embodiment, the coaxial catheter 3223, the needle tip 3224, and the positioning element 3228 comprise an insulating material. In various embodiments, the needle tip 3224 is an ultrasonic biopsy needle or an ultrasound-transmitting needle that can be observed using radioactive techniques for accurate positioning in the prostate tissue. In one embodiment, an optional catheter (not shown) may be placed in the urethra to deliver a fluid to cool the prostatic urethra 3203. In one embodiment, the insertion fluid has a temperature of less than 37°C.

[0356] Fig.32H3246, a radioactive method is used to guide the needle into the target prostate tissue. In step 3248, an ablative agent is delivered through the needle into the prostate to ablate the target prostate tissue.

[0357] Fig.33A An ablation catheter 3300 according to an embodiment of the present specification is shown. Fig.33B is a cross section of the distal end of the catheter 3300. Fig.33A and 33B , the catheter 3300 includes an elongated body 3305 having a proximal end and a distal end. A plurality of openings 3315 and an inflatable balloon 3325 are positioned proximal to the distal end. The plurality of openings 3315 allow a plurality of associated thermally conductive elements 3316 (e.g., needles) to be extended (extended at an angle from the catheter 3300, wherein the angle ranges from 30 to 90 degrees) or retracted through the plurality of openings 3315. According to one aspect, the plurality of retractable needles 3316 are hollow and include at least one opening to allow an ablative agent, such as steam 3317, to be delivered through the needles when the needles 3316 are extended and deployed through the plurality of openings 3315. The plurality of openings 3315 extend from the body 3305 and through the balloon 3325, such that the plurality of needles 3316 extend beyond the balloon 3325 when deployed.

[0358] The heating compartment 3310 is located at the proximal end of the catheter 3300. The heating compartment 3310 includes a metal coil wound around. The compartment 3310 is filled with water via a water inlet port 3311 at the proximal end of the compartment 3310. Alternating current is provided to the coil, forming a magnetic field, which induces an electric current in the ferromagnetic core, thereby heating the compartment 3310 and causing the water therein to evaporate. Finally, steam 3317 leaves the needle 3316 to ablate the target tissue. The capsule is filled by adding a refrigerant to the capsule 3325, which is supplied to the capsule 3325 through a coolant port 3312 at the proximal end of the compartment 3310. During use, the capsule 3325 is filled with coolant, and the steam generated in the compartment 3310 is transported through multiple needles 3316. Because the needles 3316 penetrate the target tissue during use, the steam 3317 transported by the puncturing needles 3316 causes tissue ablation deep in the target tissue. In some embodiments, the coolant filled balloon 3325 contacts the surface of the non-target tissue and maintains the ambient temperature of the non-target tissue surface at a desired level, such as below 60° C. This allows the steam 3317 to ablate deeper target tissue without ablating the non-target tissue at the periphery.

[0359] Fig.33C According to the use of the embodiments of this specification Fig.33A Schematic diagram of ablation catheter 3300 performing prostate ablation on an enlarged prostate in the male urinary system. Fig.33C The prostate 3330 and the prostatic urethra 3332 are shown in FIG. Fig.33A and 33C , an ablation catheter 3300 having a heating compartment 3310 and a fillable cooling capsule 3325 is inserted into the patient's urethra and advanced into the prostatic urethra 3332 so that a plurality of openings 3315 are positioned close to the tissue to be ablated. The cooling capsule 3325 is filled with a coolant supplied from a coolant port 3312 so that the filled cooling capsule 3325 is adjacent to the surface of the prostatic urethra near the prostatic tissue to be ablated. Using a pusher, a needle 3316 is then pushed out of the catheter 3300 at an angle (in various embodiments, ranging from 30 to 90 degrees) and enters the prostate 3330. Water (through the water inlet port 3311) is injected into the compartment 3310, where it is converted into steam 3317. Steam 3317 travels through the body 3305 of the catheter and leaves the opening in the needle 3316 and enters the prostatic tissue, thereby ablating the prostatic tissue. In one embodiment, the needle 3316 is thermally insulated. In some embodiments, the coolant-filled filled balloon 3325 maintains the ambient temperature on the surface of the prostatic urethra tissue at a desired level, for example, below 60° C. This allows the steam 3317 to ablate deeper prostatic tissue without ablating the prostatic urethra tissue at the surface. An optional temperature sensor may be installed to detect the temperature of the prostatic urethra and adjust the steam delivery.

[0360] Fig.33D is a flowchart according to an embodiment of the present specification, which lists the use of Fig.33A The ablation catheter 3300 is used to perform transurethral ablation of an enlarged prostate. Fig.33A and 33DAt step 3340, the ablation catheter 3300 is inserted into the urethra and advanced until the plurality of openings 3315 are positioned proximal to the prostate tissue to be ablated in the prostatic urethra. At step 3342, the cooling capsule 3325 is filled with coolant supplied from the coolant port 3312 to fix the catheter 3300 in the prostatic urethra and maintain the ambient temperature on the surface of the tissue to be ablated. At step 3344, a pusher is then used to push the needle 3316 from the catheter 3300 through the prostatic urethra at an angle (30 to 90 degrees in various embodiments) and into the prostate to a desired depth. Steam is delivered from the opening of the needle 3316 to the prostate tissue at the desired depth, thereby ablating the prostate tissue without ablating the surface of the prostatic urethra. An optional temperature sensor is used to monitor the temperature of the surface of the prostatic urethra and control or adjust the coolant flow to keep the surface temperature of the prostatic urethra below, for example, 60°C.

[0361] Fig.34A An ablation catheter 3400 according to an embodiment of the present specification is shown. Fig.34B is a cross section of the distal end of the catheter 3400. Fig.34A and 34B , the catheter 3400 includes an elongated body 3405 having a proximal end and a distal end. A first plurality of openings 3415, a second plurality of openings 3418, and a silicone or Teflon septum 3425 covering the first and second plurality of openings are positioned proximal to the distal end. The first plurality of openings 3415 allow a plurality of associated thermally conductive elements 3416 (e.g., needles) to be extended (extended at an angle from the catheter 3400, wherein the angle ranges from 30 to 90 degrees) or retracted through the plurality of openings 3415. The second plurality of openings 3418 allow coolant 3419 supplied via a coolant port 3412 at the proximal end of the catheter 3400 to be delivered to the ablation area. According to one aspect, the plurality of retractable needles 3416 are hollow and include at least one opening to allow an ablative agent, such as steam 3417, to be delivered through the needles 3416 as the needles are extended and deployed through the first plurality of openings 3415. A plurality of openings 3415 extend from the body 3405 and through the balloon 3425 such that the plurality of needles 3416, when deployed, extend beyond the septum 3425. The needles 3416 penetrate the septum 3425 when deployed such that the septum 3425 insulates the needles 3416 as they are deployed and penetrate into target tissue.

[0362] The heating compartment 3410 is located at the proximal end of the catheter 3400. The heating compartment 3410 includes a metal coil wound around. The compartment 3410 is filled with water via a water inlet port 3411 at the proximal end of the compartment 3410. Alternating current is provided to the coil, forming a magnetic field that induces an electric current in the ferromagnetic core, thereby heating the compartment 3410 and evaporating the water therein. Finally, steam 3417 leaves the needle 3416 to ablate the target tissue. A coolant port 3412 at the proximal end of the compartment 3410 supplies coolant 3419 for transport through a second plurality of openings 3418 and into the prostatic urethra. During use, the coolant 3419 is transported to the ablation area through the coolant opening 3418, and the steam 3417 generated in the compartment 3410 is transported through a plurality of needles 3416.

[0363] Because the needle 3416 penetrates the target tissue during use, the steam 3417 delivered by the puncturing needle 3416 causes ablation of tissue located deep in the target tissue. The coolant 3419 directly contacts the surface of the non-target urethral tissue and maintains the ambient temperature on the surface of the non-target tissue at a desired level, for example, below 60° C. in some embodiments, preventing or reducing clinically significant thermal damage to the non-target tissue. This allows the steam 3417 to ablate deeper prostate tissue without ablating urethral tissue at the surrounding surface. In addition, the diaphragm 3425 insulates the puncture needle 3416 and prevents the coolant 3419 from significantly cooling the needle 3416.

[0364] Fig.34C According to the use of the embodiments of this specification Fig.34A Schematic diagram of ablation catheter 3400 performing prostate ablation on an enlarged prostate in the male urinary system. Fig.34C The prostate 3430 and the prostatic urethra 3432 are shown in FIG. Fig.34A and 34C , an ablation catheter 3400 having a heating compartment 3410 and an inflatable cooling bladder 3425 is inserted into the patient's urethra and advanced into the prostatic urethra 3432 so as to position the first plurality of openings 3415 and the second plurality of openings 3418 proximal to the tissue to be ablated. Coolant 3419 is delivered through the second plurality of openings 3418 to the prostatic urethra 3432. Using a pusher, a needle 3416 is then pushed out of the catheter 3400 at an angle (in various embodiments, ranging from 30 to 90 degrees) and into the prostate 3430. The pushed out needle 3416 also passes through the insulating diaphragm 3425 covering the opening 3415.

[0365] Water (through water inlet port 3411) is injected into compartment 3410, where it is converted into steam 3417. Steam 3417 travels through the body 3405 of the catheter and leaves the opening in needle 3416 and enters the prostate tissue, thereby ablating the prostate tissue. Needle 3416 is insulated by septum 3421, and needle 3416 passes through septum 3425. The coolant-filled sac 3425 and the coolant 3419 delivered to the prostate urethra 3432 via the second plurality of openings 3418 maintain the ambient temperature on the surface of the prostate tissue at a desired level, for example, below 60°C in some embodiments. This allows steam 3417 to ablate deeper prostate tissue without ablating the prostate urethra tissue at the surface. An optional temperature sensor can be installed to detect the temperature of the prostate urethra and adjust the delivery of steam 3417 and / or coolant 3419.

[0366] Fig.34D is a flowchart according to an embodiment of the present specification, which lists the use of Fig.34A The ablation catheter 3400 is used to perform transurethral ablation of an enlarged prostate. Fig.34A and 34D At step 3440, the ablation catheter 3400 is inserted into the urethra and advanced until the first plurality of openings 3415 are positioned proximal to the prostate tissue to be ablated in the prostatic urethra. At step 3442, the cooling capsule 3425 is filled with coolant supplied from the coolant port 3412 to fix the catheter 3400 in the prostatic urethra and maintain the ambient temperature on the surface of the prostatic tissue to be ablated. At step 3444, using a pusher, the needle 3416 is pushed out of the catheter 3400 at an angle (in the range of 30 to 90 degrees in various embodiments) and penetrates the insulating septum 3421, through the prostatic urethra and into the prostate, directly to the desired depth. Steam 3417 is delivered from the opening in the needle 3416 to the prostate tissue to the desired depth, thereby ablating the prostate tissue without ablating the surface of the prostate tissue. At step 3446, the coolant 3419 is injected into the prostatic urethra via the second plurality of openings 3418 to maintain the ambient temperature on the surface of the prostatic tissue to be ablated. The diaphragm 3421 thermally insulates the puncture needle 3416 injected into the prostatic urethra from the coolant 3419. An optional temperature sensor is used to monitor the temperature of the prostate tissue surface and control or adjust the flow of the coolant to maintain the temperature of the prostate tissue surface below a specific temperature, which in some embodiments is 60°C.

[0367] See also Fig.33A and 34A According to some embodiments, a pump (e.g., a syringe pump) is used to control the flow of water to the heating compartments 3310, 3410.

[0368] In various embodiments, the catheter of the present specification further comprises at least one thermally conductive element attached to the positioning element. The at least one thermally conductive element is configured to physically contact the target tissue and in some embodiments penetrate the target tissue and enhance thermal energy delivery into the target tissue for ablation. Fig.35A is a schematic diagram of one embodiment of a positioning element 3571 of an ablation catheter 3570 showing a plurality of thermally conductive elements 3572 attached thereto. In various embodiments, the positioning element 3571 is an inflatable balloon. The positioning element or balloon 3571 is filled to a first volume to allow the thermally conductive element 3572 to contact the target tissue. The ablative agent is then delivered to the target tissue through the catheter 3570 and discharged through at least one delivery port at the distal end of the catheter 3570. Thermal energy from the ablative agent is transferred from the lumen of the catheter 3570 to the air in the balloon 3571, further expanding the volume of the balloon 3571 and pushing the thermally conductive element 3572 further into the target tissue. Thermal energy from the air in the balloon 3571 is transferred to the thermally conductive element 3572 and released into the target tissue for ablation. In various embodiments, the thermally conductive element 3572 comprises a solid or hollow metal spike or needle. In various embodiments, the balloon 3571 comprises a thermally insulating material such that ablative heat energy is primarily transmitted from the thermally conductive element 3572 to the target tissue.

[0369] Fig.35Bis a schematic diagram of one embodiment of a positioning element 3571 of an ablation catheter 3570 showing a plurality of hollow heat-conducting elements 3573 attached thereto. In one embodiment, each hollow heat-conducting element 3573 includes a valve 3583 at the entrance of the cavity from the positioning element 3571 to the hollow heat-conducting element 3573. In various embodiments, the positioning element 3571 is an inflatable balloon. The positioning element or balloon 3571 is filled to a first volume to allow the heat-conducting element 3572 to contact the target tissue. The ablative agent is then delivered to the target tissue through the catheter 3570 and discharged through at least one delivery port at the distal end of the catheter 3570. Heat energy from the ablative agent is transferred from the cavity of the catheter 3570 to the air in the balloon 3571, further expanding the volume of the balloon 3571 and pushing the heat-conducting element 3573 further into the target tissue. Heat energy from the air in the balloon 3571 is transferred to the heat-conducting element 3573 and released into the target tissue for ablation. In various embodiments, the thermally conductive element 3573 comprises a hollow metal spike or needle. The thermally conductive element 3573 comprises at least one opening at its distal end that is in fluid communication with a lumen of the thermally conductive element 3573, which in turn is in fluid communication with the interior of the bladder 3571. As shown in the cross-section of the catheter 3570, the steam follows a first path 3584 to pass from the interior of the bladder 3571 through the thermally conductive element 3573 and out of the target tissue. In one embodiment, each thermally conductive element 3573 comprises a valve 3583 positioned at its junction with the bladder 3571 to control the flow of steam into each hollow thermally conductive element 3573. In one embodiment, the steam also follows a second path 3585 into the interior of the bladder 3571 to transfer thermal energy and assist in the expansion 3571 of the bladder. In another embodiment, a flexible tube 3586 connects the lumen of each thermally conductive element 3573 with the lumen of the catheter 3570, bypassing the interior of the bladder 3571. In one embodiment, the tube 3586 comprises silicone. In this embodiment, steam may travel only via the first path 3584 and air 3587 is used to inflate the balloon 3571. In various embodiments, the balloon 3571 comprises a thermally insulating material such that ablative heat energy is primarily transmitted into the target tissue from the thermally conductive elements 3573. In various embodiments, the thermally conductive elements 3573 have shape memory properties such that they change from a shape that is generally parallel to the catheter 3570 at temperatures below the patient's body temperature to a shape that is generally perpendicular to the catheter 3570 at temperatures above the patient's body temperature.

[0370] Fig.36 is a flow chart showing one embodiment of a method of ablating tissue using a needle catheter device as described above. The device includes an insulated catheter having a hollow shaft and a retractable needle through which an ablative agent can travel, at least one injection port on the needle for delivering the ablative agent, at least one positioning element on the distal end of the catheter, and a controller including a microprocessor for controlling the delivery of the ablative agent. See Fig.36 In a first step 3601, a catheter is inserted such that a positioning element is positioned proximate to the tissue to be ablated. The next step 3602 involves extending a needle through the catheter such that an injection port is positioned proximate to the tissue. Finally, in step 3603, an ablative agent is delivered through the injection port to ablate the tissue. In another embodiment, the device does not include a positioning element and the method does not include the step of positioning a positioning element proximate to the tissue to be ablated.

[0371] In one embodiment, Fig.35A and 35B The needle catheter device is also used for steam ablation of submucosal tissue.

[0372] Fig.37 is a flow chart showing a method for ablating submucosal tissue using a needle catheter device similar to that described above. Fig.37 In a first step 3701, an endoscope is inserted into a body cavity with its distal end proximal to the tissue to be ablated. Next, in step 3702, the submucosal space is punctured using a steam delivery needle that is advanced through a catheter through a working channel of the endoscope. Next, in step 3703, steam is delivered to the submucosal space to primarily ablate the submucosal layer and / or mucosa without irreversibly or significantly ablating the deeper muscularis or serosa. In one embodiment, in step 3704, the mucosa is optionally excised with a snare or needle cutter for tissue assessment.

[0373] In another embodiment, the present specification discloses a deformable needle for ablating prostate tissue. Fig.38 is an example display of a deformation pin. Fig.38 , needle 3801a is made of a flexible material, such as nitinol, and has a curvature of -30° to 120°. In one embodiment, when heat is applied to needle 3801a, its curvature increases, as shown in 3801b. In one embodiment, the needle curvature increases in the range of -30° to 120° for a temperature increase in the range of 25°C to 75°C. According to one aspect, needle 3801a is hollow and includes at least one opening to allow delivery of an ablative agent, such as steam, through the needle.

[0374] Fig.39 FIG. 1 is a schematic diagram of performing transurethral prostate ablation on an enlarged prostate 3901 in the male urinary system using an ablation device (which utilizes a deformable needle) according to one embodiment of the present specification. Fig.39Also shown in the figure is a bladder 3902 and a prostatic urethra 3903. An ablation catheter 3923 having a handle 3920 and a positioning element 3928 is inserted into the urethra 3903 and advanced into the bladder 3902. In one embodiment, the positioning element 3928 is filled and pulled to the junction of the bladder and the urethra, thereby positioning the positioning needle 3907a a predetermined distance from the junction. Using a pusher (not shown) coupled to the handle 3920, the needle 3907a is then pushed out of the catheter 3923 through the urethra 3903 and into the prostate 3901 at an angle of 10 to 45 degrees. Steam is injected through a port (not shown), which travels through the shaft of the catheter 3923 and exits from the opening 3937 in the needle 3907a and enters the prostatic tissue, thereby ablating the prostatic tissue. According to one embodiment, as the steam is delivered, the steam delivery can heat the needle and the shape of the needle changes from being generally straight to being curved in 3907b. Upon cessation of vapor delivery, the needle returns to its original straight shape, which allows for easy withdrawal into the catheter.The mechanical shape change of the needle allows for more efficient distribution of ablation energy in the prostate tissue.

[0375] Fig.40A 4070 is a schematic diagram of an embodiment of a positioning element 4001 of an ablation catheter 4070, with a needle 4073 attached to the catheter body. In various embodiments, the positioning element 4001 is a fillable balloon. The positioning element or balloon 4001 is filled to a first volume, thereby positioning the needle 4073 at a predetermined distance from the bladder neck 4050 and allowing them to contact the target tissue. In one embodiment, an ablative agent (e.g., steam) is delivered to the target tissue through the catheter 4070. The steam exits from an opening (not shown) in the needle 4073 and enters the prostate tissue along the axis 4071 of the catheter, thereby ablating the prostate tissue. In one embodiment, the balloon 4001 can be expanded to different sizes. This feature is used in one embodiment to gradually or continuously fill the balloon 4001 to different sizes, thereby positioning the needle at various fixed distances 4051, 4052 from the bladder neck 4050, allowing different areas of the prostate tissue to be treated. In one embodiment, the predetermined distance at which the balloon is located can be used to place the needle in the range of 1mm to 50mm from the bladder neck.

[0376] exist Fig.40B In another embodiment shown, multiple fillable capsules 4011, 4012, 4013 are used as positioning elements. These capsules can be used to position the needle 4083 at various fixed distances 4061, 4062 from the bladder neck 4060, allowing different areas of prostate tissue to be treated. It should be noted that any one of the multiple capsules can be filled, depending on the tissue area to be ablated. The capsule can also be ablated in a continuous manner to allow extensive coverage of the target tissue. In one embodiment, the number of capsules is one to five.

[0377] Fig.40C A cross section of the distal end of a catheter 4091 according to an embodiment of the present specification is shown. In one embodiment, for prostate tissue ablation, the catheter used has an inner diameter (ID) of about 4 mm and an outer diameter (OD) of about 6 mm. A plurality of thermally conductive elements 4090 (e.g., needles) extend from the catheter 4091 at an angle, wherein the angle is 30 to 90 degrees. In one embodiment, the needles can be retracted into the catheter after ablation.

[0378] In one embodiment, the balloon is filled prior to ablation. In another embodiment, an ablative agent (e.g., steam) also transfers heat energy and helps expand the balloon. That is, the heat energy from the ablative agent is transferred from the catheter lumen to the air in the balloon, further expanding the space of the balloon and pushing the needle further into the target tissue. In yet another embodiment, the balloon is filled by adding a refrigerant to the balloon, and the coolant is supplied to the balloon through a coolant port at the proximal end of the catheter. During use, the balloon is filled with coolant and steam is delivered through multiple needles. Because the needles penetrate the target tissue during use, the steam delivered by the puncturing needles causes tissue located deep in the target tissue to be ablated. In some embodiments, the coolant-filled balloon contacts the surface of the target tissue and maintains the ambient temperature of the target tissue surface at a desired level, for example, below 60°C. This allows the steam to ablate deeper tissue without ablating tissue at the surface.

[0379] Fig.41 One embodiment of a handle mechanism 4100 is shown that can be used to deploy and retrieve a needle with variable insertion depths when ablating prostate tissue. Fig.41In one embodiment, the handle 4100 is shaped like a hand-held gun or pistol, which allows it to be easily operated by a physician for treating prostate tissue. The end 4101 of the handle is equipped with a channel into which an ablation catheter 4102 can be inserted for entering the patient's urethra. The ablation needle is connected to the catheter, as described in the above embodiment, and is used to deliver steam to the target tissue. On the top of the handle 4100, a mark 4103 is set, which indicates the depth of needle insertion. The mark can be set by printing, etching, drawing, engraving or by using any other means known in the art suitable for this purpose. In one embodiment, the ablation needle can be inserted or retracted in fixed distance increments - for example 5mm, and the mark is therefore set to reflect the increment accordingly. A button 4105 is set on the mark, which advances or retracts one mark each time the catheter and needle advance or retract a preset distance. In one embodiment, a trigger 4104 is set on the handle mechanism, which can be pressed to allow the needle to advance a preset distance increment. In one embodiment, once the needle has been advanced to a maximum distance by repeatedly pressing the trigger, as indicated by the labeled button 4105, further pressing the trigger will cause the needle to be retracted, one distance increment at a time. It should be noted that in the above embodiments, the catheter is also equipped with a positioning element, such as a balloon, which does not allow the catheter and needle to be advanced beyond a fixed distance in the urethra.

[0380] In one embodiment, a knob or button 4106 is provided, which can be turned or pressed to control the direction of movement of the catheter and the needle. That is, the knob 4106 can be used to determine whether the catheter and the needle move forward (advance) or backward (retract) each time the trigger 4104 is pressed.

[0381] In one embodiment, the handle mechanism 4100 also includes a heating compartment 4110, which is used to generate steam for supply to the conduit 4102. The heating compartment 4110 includes a metal coil 4112 wound around a ferromagnetic core. The compartment is filled with water via a water inlet port 4111 located at the proximal end of the handle mechanism 4100. In one embodiment, sterile water is supplied to the handle from a water source for conversion to steam. The handle is also equipped with an electrical connection 4108 to supply current to the coil 4112 from a current generator. Alternating current is provided to the coil 4112, thereby forming a magnetic field that induces current in the ferromagnetic core. This causes heating in the compartment 4110 and causes the water therein to evaporate. The final steam generated in the compartment 4110 is delivered to ablate the target tissue by a needle placed in an appropriate position.

[0382] In one embodiment, a start / stop button 4107 is also provided on the handle 4100 to start or stop the ablation treatment as needed.

[0383] Fig.42A FIG. 1 is a flow chart showing a method for ablation of prostate tissue according to an embodiment of the present specification. Fig.42A , a first step 4201 includes heating the urethra of a patient with a catheter of an ablation device, wherein the catheter includes a hollow shaft (through which an ablative agent can travel), at least one first positioning element, at least one second positioning element positioned away from the at least one first positioning element, at least one input port for receiving an ablative agent, and a plurality of needles positioned on the catheter between the first and second positioning elements and configured to deliver the ablative agent to prostate tissue. In one embodiment, the ablation device includes a controller including a microprocessor for controlling the delivery of the ablative agent. The catheter is passed through the urethra such that the first positioning element is positioned proximal to the prostate tissue to be ablated and the second positioning element is positioned away from the prostate tissue to be ablated. Next, in step 4202, the positioning elements are deployed such that they contact the urethra and the catheter is positioned in the urethra, proximal to the prostate tissue to be ablated. In the next step 4203, a plurality of needles are passed through the urethra into the prostate tissue to be ablated. Finally, in step 4204, the ablative agent is delivered through the needles to ablate the prostate tissue. Optionally, at step 4205, sensors are used to measure parameters of the prostate and the measurements are used to increase or decrease the flow rate of ablative agent being delivered at step 4206. Optionally, in an embodiment, a cystoscope is first inserted into the patient's urethra and a catheter is inserted through the cystoscope.

[0384] Fig.42B FIG. 4 is a flow chart showing a prostate tissue ablation method according to another embodiment of the present specification. Fig.42B , a first step 4211 includes passing a catheter into the patient's urethra, wherein the catheter includes a hollow shaft (through which an ablative agent can travel), at least one first positioning element, at least one second positioning element positioned away from the at least one first positioning element, at least one input port for receiving an ablative agent, and a plurality of needles positioned on the catheter between the first and second positioning elements and configured to deliver the ablative agent to the prostate tissue. In one embodiment, the ablation device includes a controller including a microprocessor for controlling the delivery of the ablative agent. The catheter is passed through the urethra such that the first positioning element is positioned proximate to the prostate tissue to be ablated and the second positioning element is positioned in the patient's bladder. Next, in step 4212, the second positioning element is deployed and the catheter is pulled back such that the second positioning element abuts the urethral opening at the neck of the bladder. In step 4213, the first positioning element is deployed such that the catheter is positioned in the urethra proximate to the prostate tissue to be ablated. In the next step 4214, a plurality of needles are passed through the urethra into the prostate tissue to be ablated. Finally, in step 4215, the ablative agent is delivered through the needles to ablate the prostate tissue. Optionally, in an embodiment, the cystoscope is first inserted into the patient's urethra and the catheter is inserted through the cystoscope. In various embodiments, the order of deployment of the positioning elements can be reversed. In other embodiments, only one of the two positioning elements can be deployed to perform treatment.

[0385] In various embodiments, ablation therapy provided by the steam ablation system of the present specification is performed to achieve the following treatment features for prostate ablation: maintaining tissue temperature at 100°C or less; improving the patient's urine flow by at least 5% relative to pre-treatment urine flow; reducing the prostate volume by at least 5% relative to pre-treatment prostate volume; ablating prostate tissue without ablating surrounding urethral tissue; improving the International Prostate Symptom Score (IPSS) by at least 5% relative to pre-treatment IPSS, wherein Fig.43A The IPSS questionnaire shown includes a series of questions about the patient's urinary habits, and a numerical score for each question 4381; relative to the pre-treatment Benign Prostatic Hypertrophy Impact Index Questionnaire (BPHIIQ) score, improve the BPHIIQ score by at least 10%, where Fig.43B The BPHIIQ shown includes a series of questions 4385 regarding the patient's urinary problems, along with a numerical score 4386 for each question; and patient-reported satisfaction with the ablation procedure greater than 25%.

[0386] The above examples are merely demonstrations of many applications of the system of the present invention. Although only a few embodiments of the present invention are described herein, it should be understood that the present invention can be implemented in many other specific forms without departing from the spirit or scope of the present invention. Therefore, the examples and embodiments of the present invention are considered to be exemplary rather than restrictive, and the present invention can be changed within the scope of the appended claims.

Claims

1. A catheter suitable for ablating body tissue, comprising: an outer capsule having an outer surface defining an interior space; an inner bladder configured to expand within the interior space of the outer bladder; a first lumen within the catheter and in fluid communication with the interior space of the inner balloon, wherein the first lumen is configured to direct an ablative agent to the interior space of the inner balloon, and wherein the ablative agent is defined by a first temperature; and A second lumen is within the catheter and is fluidly connected to the interior space of the outer balloon, wherein the second lumen is configured to guide the fluid to the interior space of the outer balloon, and wherein the fluid is defined by a second temperature lower than the first temperature, wherein when the fluid causes the interior space of the outer balloon to expand and the ablative agent causes the interior space of the inner balloon to expand, an ablation zone is created at the contact area between the outer balloon and the inner balloon, so that the ablation zone is at a temperature sufficient to ablate body tissue, while portions of the outer balloon other than the ablation zone remain at a temperature lower than the ablation zone.

2. A catheter suitable for ablating body tissue according to claim 1, wherein the ablative agent comprises at least one of water vapor or steam.

3. A catheter suitable for ablating body tissue according to claim 1, wherein: The fluid includes at least one of water or air.

4. A catheter suitable for ablating body tissue according to claim 1, wherein the inner balloon comprises a first material, the outer balloon comprises a second material, and wherein the first material is more flexible than the second material.

5. A catheter suitable for ablating body tissue according to claim 4, wherein: The first material is latex and the second material is PET.

6. A catheter suitable for ablating body tissue according to claim 1, further comprising a first opening or inlet located at the proximal end of the catheter and configured to direct the fluid to the second lumen.

7. A catheter suitable for ablating body tissue according to claim 1, further comprising a second opening or inlet located at the proximal end of the catheter and configured to direct the fluid out of the catheter.

8. A catheter suitable for ablating body tissue according to claim 1, wherein: When the fluid expands the interior space of the outer balloon, the outer balloon has a primarily cylindrical shape.

9. A catheter suitable for ablating body tissue according to claim 1, wherein: When the inner space of the outer balloon is expanded, the outer balloon has a tapered shape at its proximal end and has a tapered shape at its distal end.

10. A catheter suitable for ablating body tissue according to claim 9, wherein: When the inner space of the outer bag is expanded, the length of the central cylindrical part of the outer bag is 60 mm + 25 mm, the length of the tapered portion at the proximal end is 12 mm + 10 mm, and the length of the tapered portion at the distal end is 12 mm + 10 mm.

11. A catheter suitable for ablating body tissue according to claim 1, wherein: When the inner space of the outer bag is expanded, the width of the central cylindrical part of the outer bag is 24 mm + 15 mm.

12. The catheter suitable for ablating body tissue according to claim 1, characterized in that The inner balloon is spherical when filled with ablative agent.

13. The catheter suitable for ablating body tissue according to claim 1, characterized in that The inner balloon also includes structures at its proximal and distal ends to properly position the inner balloon within the catheter.

14. The catheter suitable for ablating body tissue according to claim 1, further comprising: a first opening located at a first position in the catheter and configured to allow fluid to flow from the second lumen into the outer balloon; and At least one second opening is located at a second position in the catheter and is configured to allow saline to flow through the first lumen to the inner balloon, wherein the first and second positions are different.

15. The catheter suitable for ablating body tissue according to claim 1, characterized in that The shape of the ablation area is determined by the shape of the inner balloon when inflated and the shape of the outer balloon when inflated.

16. The catheter suitable for ablating body tissue according to claim 1, characterized in that The size of the ablation zone is determined by the shape of the inner balloon when expanded and the shape of the outer balloon when expanded.

17. A catheter adapted for ablating body tissue according to claim 1, further comprising a delineation member distal to the outer balloon, wherein the delineation member comprises a plurality of electrodes configured to record cardiac pacing.

18. The catheter suitable for ablating body tissue according to claim 1, characterized in that The inner balloon is movable within the outer balloon and along the length of the outer balloon along the longitudinal axis of the catheter.

19. The catheter suitable for ablating body tissue according to claim 1 further comprises a plurality of delineation electrodes located within or attached to the outer surface of the outer balloon, wherein the plurality of delineation electrodes are configured to record cardiac signals to delineate areas of cardiac tissue causing arrhythmias.

20. A catheter adapted for ablating body tissue according to claim 1, further comprising at least one temperature sensor configured to monitor temperature.

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