Cryoballoon with Directed Gas Control

Abstract

Embodiments of the present invention provide a medical probe that includes an insertion tube, an inflatable balloon, an injection tube, and an orientation control tube. The insertion tube includes a distal end configured to be inserted into a body cavity and includes a lumen that is open through the distal end. The inflatable balloon is deployable through the lumen into the body cavity. The injection tube extends from the lumen into the balloon and includes a plurality of holes that are radially distributed around the injection tube and lead into the balloon and are configured to deliver a refrigerant from the injection tube into the balloon. The orientation control tube surrounds the injection tube and is rotatable about the injection tube and includes a semi-tubular section configured to cover one or more of the holes to block the refrigerant from exiting through one or more of the holes.

Description

Technical Field

[0001] The present invention generally relates to invasive probes, and more particularly to invasive probes configured to perform cryoablation. Background Art

[0002] Cryoablation is a medical procedure that uses extremely cold temperatures to destroy tissue. Cryoablation can be performed on cardiac tissue to restore normal heart rhythm by disabling the cardiac cells that produce irregular heartbeats. During this minimally invasive procedure, a thin flexible tube called a balloon catheter is used to locate and freeze the cardiac tissue that triggers the irregular heartbeat.

[0003] U.S. Patent Application 2012 / 0165803 to Bencini et al. describes a method for electrophysiological mapping and cryoablation using a balloon catheter. The method includes delivering a coolant into a balloon located at the distal end of the catheter. In one embodiment, the coolant delivery lumen is coupled to a coil that wraps around a shaft housed within the balloon, and the coolant is delivered via a plurality of holes in the coil. In another embodiment, the coolant can be delivered into the balloon via a hole located at the end of the coolant delivery lumen.

[0004] U.S. Patent 5,147,355 to Friedman et al. describes a cryoablation catheter and method for performing cryoablation. The cryoablation catheter is configured to regulate a cryogenic fluid to provide reversible cooling. Additionally, the catheter can sense electrical activity during the performance of cryoablation.

[0005] U.S. Patent Application 2010 / 0179526 to Lawrence describes a medical system that includes a cryoablation balloon catheter. The catheter includes a coolant delivery tube and a guide tube located inside the balloon, the coolant delivery tube extending along the guide tube and having a coiled distal end that wraps around the guide tube. The coiled distal end includes a plurality of injection holes configured to deliver the coolant into the balloon.

[0006] U.S. Patent Application 2014 / 0142666 to Phelan et al. describes a cryotherapy device (e.g., a catheter). The device includes a shaft surrounded by an inflatable body (e.g., a balloon) having a plurality of lumens. Each of the lumens can be fluidically independent of one another and is configured to receive different types of fluids and / or fluids having different temperatures.

[0007] The above description provides a general overview of the relevant art in the field and should not be construed as admitting that any of the information it contains constitutes prior art against the present patent application.

[0008] Documents incorporated by reference into this patent application are considered an integral part of this application, except that any terms defined in such incorporated documents that conflict with the definitions expressly or implicitly set forth in this specification shall be considered only in accordance with the definitions in this specification. Summary of the Invention

[0009] According to an embodiment of the present invention, there is provided a medical probe, the medical probe comprising: an insertion tube having a distal end configured to be inserted into a body cavity and containing a lumen open through the distal end; and an inflatable balloon deployable through the lumen into the body cavity. The medical probe includes an injection tube extending from the lumen into the balloon and including a plurality of holes radially distributed around the injection tube and leading into the balloon, and configured to deliver a refrigerant from the injection tube into the balloon. The medical probe further includes an orientation control tube surrounding the injection tube and capable of rotating around the injection tube, and including a semi-tubular section configured to cover one or more of the holes, thereby blocking the refrigerant from exiting through the one or more of the holes.

[0010] In some embodiments, the medical probe further includes a processor and a handle coupled to the insertion tube and having controls, wherein the processor is configured to regulate the delivery of the refrigerant to the injection tube in response to a signal received from the controls. In additional embodiments, the medical probe further includes a processor and a handle coupled to the insertion tube and having controls, wherein the processor is configured to regulate the extension of the orientation control tube over the holes in response to a signal received from the controls. In one embodiment, the handle includes a visual indicator, and wherein the processor is configured to present the degree of extension of the orientation control tube over the holes on the visual indicator.

[0011] In additional embodiments, the medical probe further includes a processor and a handle coupled to the insertion tube and having controls, wherein the processor is configured to regulate the rotation of the orientation control tube relative to the anatomical structure in response to a signal received from the controls. In supplementary embodiments, the medical probe further includes a handle having controls that regulate the rotation of the orientation control tube around the injection tube. In one embodiment, the handle includes a visual indicator, and wherein the processor is configured to present the angle of rotation of the orientation control around the injection tube on the visual indicator.

[0012] In some embodiments, the semi-tubular section includes a plurality of sections having different blocking angles, each of the sections being configured to cover a different corresponding number of holes. In additional embodiments, the semi-tubular section includes markers visible under fluoroscopy. In additional embodiments, the orientation control tube includes a position sensor that sends a signal indicating the position of the semi-tubular section relative to the injection tube.

[0013] In supplementary embodiments, the semi-tubular section has an arcuate cross-section. In one embodiment, the orientation control tube includes a position sensor that sends a signal indicating the orientation of the semi-tubular section relative to the anatomy of the body cavity. In another embodiment, the orientation control tube blocks the refrigerant from exiting by redirecting the refrigerant.

[0014] In an embodiment of the present invention, a method for manufacturing a medical probe is also provided, the method comprising: providing an insertion tube having a distal end configured for insertion into a body cavity and containing a lumen open through the distal end; providing an inflatable balloon capable of being deployed into the body cavity through the lumen; providing an injection tube extending from the lumen into the balloon and including a plurality of holes radially distributed around the injection tube and leading into the balloon and configured for delivering a refrigerant from the injection tube into the balloon; and providing an orientation control tube surrounding the injection tube and capable of rotating around the injection tube and including a semi-tubular section configured to cover one or more of the holes, thereby blocking the refrigerant from exiting through the one or more of the holes.

[0015] In an embodiment of the present invention, a method is also provided, the method comprising: inserting a distal end of a medical probe into a body cavity of a patient, the medical probe comprising: an insertion tube having a distal end configured to be inserted into the body cavity and containing a lumen open through the distal end; an inflatable balloon capable of being deployed into the body cavity through the lumen; an injection tube extending from the lumen into the balloon and including a plurality of holes radially distributed around the injection tube and leading into the balloon, and configured to deliver a refrigerant from the injection tube into the balloon; and an orientation control tube surrounding the injection tube and capable of rotating around the injection tube and advancing over the injection tube, and including a semi-tubular section configured to cover one or more of the holes, thereby blocking the refrigerant from exiting through the one or more of the holes. The method further comprises: selecting an area of tissue to be ablated in a region distal to the medical probe in the body cavity; pressing a distal face of the balloon against the selected area of the tissue; rotating the orientation control tube such that the semi-tubular section covers one or more of the holes facing away from the selected area of the tissue; and delivering the refrigerant to the injection tube to cryoablate the selected area of the tissue.

[0016] In an embodiment of the present invention, a medical probe is also provided, the medical probe comprising: a tubular member extending from a proximal end to a distal end along a longitudinal axis; at least one inflatable membrane coupled to the tubular member between the proximal end and the distal end; an injection tube disposed within the at least one inflatable membrane, the injection tube having a plurality of holes angled around the injection tube to allow fluid to flow out of the plurality of holes into the at least one inflatable membrane; and a control tube disposed between the injection tube and the tubular member, the control tube having a plurality of arcuate sections disposed along the length of the control tube, wherein each arcuate section defines less than a full circumference of the control tube such that some of the holes of the injection tube are exposed to the inflatable membrane depending on the orientation of the control tube relative to the injection tube.

[0017] In some embodiments, the injection tube includes a fixed member relative to a rotatable and translatable control tube. In additional embodiments, the injection tube is capable of rotating and translating relative to the fixed control tube. In further embodiments, at least one radiopaque marker is disposed on at least one of the injection tube and the control tube to allow identification of the orientation of the injection tube relative to the control tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] This disclosure is described by way of example only with reference to the accompanying drawings, wherein:

[0019] Figure 1 is a schematic illustration of a medical system configured to perform cryoablation using a balloon catheter according to an embodiment of the present invention;

[0020] Figure 2 is a schematic longitudinal sectional view of a distal end of a balloon catheter including a blocking assembly according to an embodiment of the present invention;

[0021] Figure 3 is a schematic longitudinal view of a blocking element according to a first embodiment of the present invention;

[0022] Figure 4 is a schematic longitudinal view of a blocking element according to a second embodiment of the present invention;

[0023] Figure 5 shows a schematic latitudinal sectional view of a section of a blocking element according to a second embodiment of the present invention;

[0024] Figure 6 is a flowchart schematically showing a method of performing cryoablation on endocardial tissue in the heart using a balloon catheter; and

[0025] Figure 7 is a schematic detail view of a distal end of a balloon located in a chamber of the heart according to an embodiment of the present invention. DETAILED DESCRIPTION

[0026] Overview

[0027] Embodiments of the present invention describe a system and method for performing cryoablation of cardiac tissue. As described below, the system includes a medical probe that includes an insertion tube, an inflatable balloon, an injection tube, and an orientation control tube. The insertion tube has a distal end configured for insertion into a body cavity and includes a lumen that is open through the distal end, and the inflatable balloon can be deployed into the body cavity through the lumen. The insertion tube extends from the lumen into the balloon and includes a plurality of holes that are radially distributed around the insertion tube and lead into the balloon and are configured to deliver a refrigerant from the injection tube into the balloon. The orientation control tube surrounds the second tube and is rotatable about the second tube and includes a semi-tubular section configured to cover one or more of the holes so as to block or redirect the refrigerant from one or more of the holes.

[0028] By rotating the orientation control tube, a medical professional using the system implementing an embodiment of the present invention can direct refrigerant to a section of the balloon, thereby preferentially performing cryoablation on the cardiac tissue in contact with that section of the balloon. For example, when performing cryoablation on the ostium of the pulmonary vein entry, it may be preferable to direct more refrigerant to the anterior wall of the vein, which is significantly thicker than the posterior wall of the vein, thereby protecting the esophageal tissue just outside the anterior wall (i.e., not being damaged by the refrigerant).

[0029] System Description

[0030] Figure 1 FIG. is a schematic illustration of a medical system 20 including a medical probe 22 (e.g., an intracardiac catheter) and a console 24 according to an embodiment of the present invention. The system 20 can be based on, for example, a system manufactured by Biosense Webster Inc. (33 Technology Drive, Irvine, CA 92618 USA). system. In the embodiments described below, it is assumed that the probe 22 is used for diagnostic or therapeutic procedures, such as performing ablation of cardiac tissue in the heart 28. Alternatively, with necessary modifications, the probe 22 can be used for other therapeutic and / or diagnostic purposes in the heart or other body organs.

[0031] The probe 22 includes an insertion tube 30 and a handle 32 coupled to the proximal end of the insertion tube. By manipulating the handle 32, a medical professional 34 can insert the probe 22 into the body cavity of a patient 36. For example, the medical professional 34 can insert the probe 22 through the vascular system of the patient 36 such that the distal end 26 of the probe 22 enters the chamber of the heart 28 and engages the endocardial tissue at the desired one or more locations.

[0032] In some embodiments, the medical professional 34 can use a fluoroscopy unit 38 to visualize the distal end 26 within the heart 28. The fluoroscopy unit 38 includes an X-ray source 40 positioned above the patient 36 that transmits X-rays through the patient. A flat panel detector 42 positioned below the patient 36 includes a scintillator layer 44 that converts the X-rays passing through the patient 36 into light, and a sensor layer 46 that converts the light into an electrical signal. The sensor layer 46 typically includes a two-dimensional array of photodiodes, where each photodiode generates an electrical signal proportional to the light detected by that photodiode.

[0033] The console 24 includes a processor 48 that converts electrical signals from the fluoroscopy unit 38 into an image 50, and the processor presents the image on a display 52 as information regarding a procedure. By way of example, assume that the display 52 includes a cathode ray tube (CRT) display or a flat panel display, such as a liquid crystal display (LCD), a light emitting diode (LED) display, or a plasma display. However, other display devices may also be used to implement embodiments of the present invention. In some embodiments, the display 52 may include a touch screen that may be configured to receive input from the medical professional 34 in addition to presenting the image 50.

[0034] In addition or alternatively, the medical system 20 may use magnetic orientation sensing to determine orientation coordinates that indicate the position and orientation of the distal end 26 in a coordinate system 54 that includes an X-axis 56, a Y-axis 58, and a Z-axis 60. To implement magnetic-based orientation sensing, the console 24 includes drive circuitry 62 for driving a field generator 64 to generate a magnetic field within the patient 36. Typically, the field generator 64 includes three orthogonally oriented coils that are disposed below the volume at known positions outside the patient 36. The distal end 26 includes a magnetic field sensor 66 (also referred to herein as a position sensor or an orientation sensor) that generates a signal in response to the magnetic field.

[0035] Although Figure 1 the illustrated medical system uses magnetic-based sensing to measure the position of the distal end 26, other orientation tracking techniques (e.g., impedance-based sensors) may also be used. Magnetic orientation tracking techniques are described, for example, in U.S. Pat. Nos. 5,391,199, 5,443,489, 6,788,967, 6,690,963, 5,558,091, 6,172,499, 6,177,792, which are hereby incorporated by reference as if set forth in full in this application and appended hereto. Impedance-based position tracking techniques are described, for example, in U.S. Pat. Nos. 5,983,126, 6,456,864, and 5,944,022, which are hereby incorporated by reference as if set forth in full in this patent application and appended hereto. The methods of orientation sensing described above are implemented in the CARTO TM system and are described in detail in the patents cited above.

[0036] The console 24 may further include an input / output (I / O) communication interface 68 that enables the console to communicate signals from the magnetic field sensor 66 and the fluoroscopy unit 38 and / or to communicate the signals to the magnetic field sensor and the fluoroscopy unit. Based on the signals received from the magnetic field sensor 66 and the fluoroscopy unit 38, the processor 48 may generate an image 50 including a mapping diagram that shows the orientation of the distal end 26 within the patient's body. During the procedure, the processor 48 may present the mapping diagram to the medical professional 34 on the display 52 and store the data representing the mapping diagram in the memory 70. The memory 70 may include any suitable volatile and / or non-volatile memory, such as random access memory or a hard disk drive.

[0037] The console 24 may further include an inflation module 72 and a cryoablation module 74. As described below in reference to Figure 2 the description, the distal end 26 includes an inflatable balloon that is configured to deliver cryoablation energy to tissue in the heart 28. In some embodiments, the inflation module 72 may deliver a refrigerant (described in more detail below) via the aperture 106 into the balloon 90 to inflate the balloon.

[0038] The cryoablation module 74 is configured to monitor and control ablation parameters by regulating the delivery of the refrigerant to the balloon at the distal end 26. Examples of refrigerants include, but are not limited to, liquid N 2 O, Freon, argon, CO 2 gas, and near-critical N 2 . In some embodiments, the medical professional 34 may use one or more input devices 80 to manipulate the image 50 and control the parameters of the inflation module 72 and the cryoablation module 74.

[0039] The processor 48 may include a real-time noise reduction circuit 76 that is typically configured as a field programmable gate array (FPGA), followed by an analog-to-digital (A / D) electrocardiogram (ECG) signal conversion integrated circuit 78. The processor may pass the signal from the A / D ECG circuit 78 to another processor and / or may be programmed to execute one or more algorithms disclosed herein, each of the one or more algorithms including the steps described below. The processor uses the circuit 76 and the circuit 78, as well as the features of the modules described in more detail below, to execute the one or more algorithms.

[0040] Figure 2Schematic longitudinal sectional view of the distal end 26 according to an embodiment of the present invention. The distal end 26 includes a balloon 90 (also referred to herein as an inflatable membrane), which can be deployed through the lumen 122 at the distal end 124 of the insertion tube 30. The balloon 90 includes a proximal end 92 attached to an outer tubular shaft 94. The distal end 96 is attached to an inner tubular shaft 98, which is received within the outer tubular shaft. The shafts 94 and 98 may also be referred to herein as tubular members 94 and tubular members 98.

[0041] Both the shaft 94 and the shaft 98 are configured to extend from the lumen 122 at the distal end of the insertion tube 30. In Figure 2 the example shown, the balloon 90 is shown in an inflated state and is typically formed of a biocompatible material such as polyethylene terephthalate (PET), polyurethane, nylon, or silicone. For safety reasons, the distal end 26 may include a second balloon (not shown), which surrounds the balloon 90 and is generally used to ensure that balloon rupture does not result in gas leakage into the patient. The balloon 90 is generally non-compliant, and the medical professional 34 can control the diameter of the balloon (i.e., when inflated) by extending or retracting the inner tubular shaft 98.

[0042] The distal end 26 also includes an injection tube 100, the proximal end of which is coupled to the cryoablation module 74 and the distal end of which is coupled to an injection coil 102. The injection tube 100 is disposed along the inner shaft 98, and the injection coil 102 is wound around the inner shaft at the distal end 96. The injection coil 102 includes a plurality of outward-facing holes 106 such that the holes are radially (i.e., angularly) distributed around the inner shaft 98 and lead into the balloon 90. The holes 106 are configured to deliver a refrigerant from the injection tube 100 to the interior of the balloon 90. In some embodiments, the refrigerant may include those refrigerants mentioned above and / or a pressurized liquid coolant that changes state to a gas when discharged from the holes 106. In the embodiments described herein, the injection tube 100 and the injection coil 102 may be collectively referred to as the injection tube 100.

[0043] The distal end 26 also includes an orientation control tube 104, which is received within the outer shaft 94, surrounds the inner shaft 98, and is rotatable about the inner shaft. In one embodiment, the injection tube 100 is fixed relative to the rotatable and translatable control tube 104. In an alternative embodiment, the injection tube 100 may be rotatable and translatable relative to the fixed control tube 104. In another embodiment, both the injection tube 100 and the control tube 104 may be movable relative to each other.

[0044] In an embodiment of the present invention, the directional control tube 104 includes a portion 108 along the length of the tube that lacks a predetermined arcuate wall portion of the control tube to allow the inner surface of the control tube 104 to be exposed. For simplicity, this portion 108 will be referred to as the semi-tubular section 108 (also referred to herein as the blocking element 108), which is configured to cover one or more holes 106, thereby blocking or redirecting refrigerant from exiting through one or more of the holes.

[0045] In addition to rotating about the inner shaft 98, the directional control tube 104 is also configured to move longitudinally (i.e., forward and backward) along the inner shaft, as indicated by the bidirectional arrow 110. In other words, the directional control tube 104 can be advanced over the injection tube 100 and the injection coil 102. The medical professional 34 can use the rocker switch control 114 on the handle 32 to control the longitudinal movement of the directional control tube 104, and can use the rotatable knob control 116 on the handle to control the rotation of the directional control tube.

[0046] In some embodiments, the processor 48 can determine the orientation (i.e., position and orientation) of the blocking element 108 in the coordinate system 54, and in response to the determined orientation, the processor can control the rotation of the directional control tube 104 about the injection tube 100 via an integrated motor (not shown) in the handle 32. In additional embodiments, the processor 48 can control the rotation of the directional control tube 104 about the injection tube 100 using the integrated motor in response to a signal received from the control 116. In additional embodiments, the processor 48 can control the extension and retraction of the directional control tube 104 in response to a signal from the control 114.

[0047] In some embodiments, the handle 32 may further include a visual indicator 118 (e.g., one or more LEDs or a small LED display), which the processor 48 can manipulate to indicate the rotational angle and / or extension of the blocking element 108 within the balloon 90. In addition or alternatively, the processor 48 can present rotation and extension information on the display 52. In Figure 2 In the configuration shown, the handle 32 further includes an ablation control button 112, which the medical professional can press to control the refrigerant delivered from the cryoablation module 74 into the injection tube 100.

[0048] In some embodiments, the processor 48 may use signals from the magnetic field sensor 66 to determine the position and / or orientation of the blocking element 108 (i.e., relative to the injection tube 100 and / or the injection coil 102). The magnetic field sensor 66 may be in the form of a uniaxial sensor, as used in co-owned U.S. Patent 6,484,118, which is incorporated herein by reference as if set forth in full and appended hereto. In embodiments in which the medical system 20 uses impedance-based orientation tracking (where the position sensor 66 includes electrodes), the orientation control tube 104 may include additional electrodes, and the processor 48 may use signals from these electrodes to determine the orientation of the blocking element 108. In another embodiment, a hybrid magnetic and impedance orientation sensing system may be used to sense the position of any component of the distal portion of the balloon 90, injection tube 100, control tube 104, or catheter 26 relative to the patient's anatomy. Such hybrid magnetic-impedance orientation sensing is shown and described in co-owned U.S. Patent 7,536,218, which is incorporated herein by reference as if set forth in full and appended hereto.

[0049] In addition or alternatively, the blocking element 108 may include one or more markers 120 (e.g., squares) that are opaque to fluoroscopy for detection by the fluoroscopy unit 38 such that the processor 48 may indicate its orientation on the display 52. In operation, the medical professional 34 may use the position of the marker 120 to determine the position of the orientation control tube 104 relative to the injection coil 102 and the orientation of the blocking element relative to the patient 36's anatomy.

[0050] In embodiments having a single marker 120 located on the blocking element 108, the marker may include any shape that is not bilaterally symmetric. In Figure 2 the example shown, the marker 120 is in the shape of the letter "L", and the medical professional 34 may determine the orientation (i.e., relative orientation) of the blocking element 108 based on the blocking element presented on the display 52. In this example, if the display 52 presents the marker 120 as an "L" shape, the blocking element is located in front of the injection coil 102. Similarly, if the display 52 presents the marker 120 as a backward "L" shape, the blocking element is located behind the injection coil 102.

[0051] In embodiments having more than one marker 120, a first marker 120 may be disposed on the barrier element 108 and a second marker 120 may be disposed on the injection tube 100 such that a healthcare professional 34 can determine the orientation of the barrier element based on the markers presented on the display 52. In some embodiments, the radiopaque marker on the barrier element 108 may have a different shape than the marker 120 on the injection tube 100 to allow identification of the relative orientation of the injection tube 100 and the control tube 104 via the two markers.

[0052] Figure 3 Schematic longitudinal view of the barrier element 108 according to a first embodiment of the present invention. In Figure 3 the configuration shown, the barrier element 108 includes a single section having a common angle 130.

[0053] Figure 4 Schematic longitudinal view of the barrier element 108 according to a second embodiment of the present invention. In Figure 4 the configuration shown, the barrier element 108 includes a first section 140 having a first blocking angle 146, a second section 142 having a second blocking angle 148 greater than the first angle, and a third section 144 having a third blocking angle 150 greater than the second angle. In this second embodiment, the healthcare professional 34 can control the injection angle of the refrigerant into the balloon 90 by extending and retracting the barrier element 108. The angle 150 in section 144 can block from 20 degrees to 60 degrees, the angle 148 in section 142 can block from 60 degrees to 120 degrees, and the angle 146 can block from 90 degrees to 180 degrees.

[0054] When the section 140 extends over the injection coil 102, the first section covers a first number of holes 106 and the holes can deliver the refrigerant to the balloon at a first injection angle. When the section 142 extends over the injection coil 102, the second section covers a second number (less than the first number) of holes 106 and the holes can deliver the refrigerant to the balloon at a second injection angle greater than the first injection angle. When the section 144 extends over the injection coil 102, the third section covers a third number (less than the second number) of holes 106 and the holes can deliver the refrigerant to the balloon at a third injection angle greater than the second injection angle.

[0055] Although Figure 4The configuration of the barrier element 108 shown has three sections 140, 144, and 148, but barrier elements including any number of sections are considered to be within the spirit and scope of the present invention. For example, a greater number of sections can be used to allow those skilled in the art to have more choices in the selection of the blocking angle. In addition or alternatively, although the control tube 104 is described as being translatable and rotatable relative to the injection tube 100 as a reference datum, configuring the injection tube 100 to be rotatable and translatable relative to the control tube 104 as a reference datum is also within the scope of the present invention.

[0056] Figure 5 A schematic latitudinal cross-sectional view of sections 140, 142, and 144 extending over a portion of the injection coil 102 according to an embodiment of the present invention is shown. As shown, the first section 140 covers three holes 106 when extending over a portion of the injection coil 102, the second section 142 covers two holes 106 when extending over a portion of the injection coil 102, and the third section 144 covers a single hole 106 when extending over a portion of the injection coil 102.

[0057] As Figure 5 shown, each of the sections 140, 142, and 144 of the semi-tubular element 108 has a corresponding different arcuate cross-section. Similarly, Figure 3 the single section of the semi-tubular element 108 shown has an arcuate cross-section.

[0058] Figure 6 A flowchart schematically showing a method for performing a cryoablation procedure on tissue in the heart 28 according to an embodiment of the present invention, and Figure 7 a schematic detail view of the distal end 26 located in the chamber 180 of the heart according to an embodiment of the present invention. As Figure 7 shown, the chamber 180 is connected to the pulmonary vein 184 through a corresponding orifice 182.

[0059] In the identification step 160, the medical professional 34 identifies the section of the endocardial tissue for cryoablation. In Figure 7 the example shown, the identified endocardial tissue includes a given orifice 182 connected to a given pulmonary vein 184.

[0060] In the selection step 162, the medical professional 34 selects the area 190 of the identified tissue to deliver a higher level of cryoablation energy. In Figure 7In the example shown, the selected region may include the anterior wall of a given pulmonary vein. The posterior wall of the given pulmonary vein is thinner than the anterior wall and is closer to the esophagus 188. Thus, delivering a lesser amount of cryoablation energy to the posterior wall of the given pulmonary vein can protect the tissue in the esophagus that may be damaged by the cryoablation effect of the refrigerant in the inflatable membrane. In an alternative embodiment, the processor 48 may perform the selection step 162.

[0061] In the insertion step 164, the healthcare professional 34 manipulates the handle 32 to insert the distal end 26 of the probe 22 into the heart chamber 180, and in the inflation step 166, the healthcare professional may inflate the balloon 90. To inflate the balloon 90, the healthcare professional may use the inflation module 72 to control the inflation pressure of the balloon 90 in response to the size of the selected tissue.

[0062] In the rendering step 168, when the handle 32 is manipulated to maneuver the medical probe, the processor 48 renders an image 50 on the display 52 that includes the current position of the balloon 90. In some embodiments, the processor 48 may generate and render the image 50 based on signals received from the fluoroscopy unit 38. Additionally or alternatively, the processor 48 may generate and render the image 50 based on signals received from the magnetic field sensor 66.

[0063] In the positioning step 170, the healthcare professional 34 manipulates the handle 32 to position the balloon 90 such that the balloon is pressed against the identified ostium, and in the first cryoablation step 172, in response to the healthcare professional pressing the ablation button 112, the processor 48 may command the cryoablation module 74 to deliver the refrigerant to the injection coil 102, which in turn delivers the refrigerant to cryoablate the identified ostium tissue. During step 172 (i.e., at the start of the cryoablation procedure), the blocking element 108 may be retracted and thus located proximal to the injection coil 102, such that all of the holes in the injection coil can deliver the refrigerant in an angularly symmetric manner to the balloon, thereby delivering cryoablation energy to any ostium tissue in contact with the balloon.

[0064] In the deployment step 174, the healthcare professional manipulates the controls 114 and 116 such that the blocking element 108 extends over the injection coil 102 and the holes facing the selected region are exposed (i.e., not covered by the blocking element). Finally, in the second cryoablation step 176, in response to the healthcare professional pressing the ablation button 112, the cryoablation module 74 delivers the refrigerant to the injection coil 102. The coil 102 delivers the refrigerant to deliver additional cryoablation energy to the selected region 190, and the method ends.

[0065] As Figure 7As shown, when the blocking element 108 extends over the injection coil 102, the blocking element covers one or more holes 106 that face away from the selected region 190. Thus, the blocking element 108 blocks or redirects any coolant delivered to the holes 106 covered by the blocking element, and these holes can direct the delivery of refrigerant to the selected region 190, as indicated by arrow 186. In Figure 7 Figure 192 includes a top view of the heart 28, and the orientation of the blocking element 108 directs the refrigerant away from the esophagus 188, as indicated by arrow 186.

[0066] It should be understood that the above embodiments are cited by way of example, and the present invention is not limited to what is specifically shown and described above. On the contrary, the scope of the present invention includes combinations and sub - combinations of the various features described above, as well as their variations and modifications, which would occur to those skilled in the art upon reading the above description and which are not disclosed in the prior art.

Claims

1. A medical probe, comprising: an insertion tube having a distal end configured to be inserted into a body cavity and including a lumen open through the distal end; an inflatable balloon that can be deployed through the lumen into the body cavity; an injection tube extending from the lumen into the balloon and including a plurality of holes radially distributed around the injection tube and leading into the balloon, and configured to deliver a refrigerant from the injection tube into the balloon; and an orientation control tube surrounding the injection tube and capable of rotating around the injection tube and longitudinally moving along the injection tube, and including a semi-tubular section configured to cover one or more of the holes, thereby blocking the refrigerant from leaving through the one or more of the holes; wherein the semi-tubular section includes a plurality of sections having different blocking angles, each of the sections being configured to cover a different corresponding number of holes.

2. The medical probe according to claim 1, further comprising a processor and a handle coupled to the insertion tube and having controls, wherein the processor is configured to regulate the delivery of the refrigerant to the injection tube in response to a signal received from the controls.

3. The medical probe according to claim 1, comprising a processor and a handle coupled to the insertion tube and having controls, wherein the processor is configured to regulate the extension of the orientation control tube over the holes in response to a signal received from the controls.

4. The medical probe according to claim 3, wherein the handle includes a visual indicator, and wherein the processor is configured to present on the visual indicator the degree of extension of the orientation control tube over the holes.

5. The medical probe according to claim 1, comprising a processor and a handle coupled to the insertion tube and having controls, wherein the processor is configured to regulate the rotation of the orientation control tube relative to the anatomy of the body cavity in response to a signal received from the controls.

6. The medical probe according to claim 1, comprising a processor and a handle including controls that regulate the rotation of the orientation control tube around the injection tube.

7. The medical probe according to claim 6, wherein the handle includes a visual indicator, and wherein the processor is configured to present on the visual indicator the angle of rotation of the orientation control tube around the injection tube.

8. The medical probe according to claim 1, wherein the semi-tubular section includes markers visible under fluoroscopy.

9. The medical probe according to claim 1, wherein the orientation control tube includes a position sensor that sends a signal indicating the position of the semi-tubular section relative to the injection tube.

10. The medical probe according to claim 1, wherein the semi-tubular section has an arcuate cross-section.

11. The medical probe according to claim 1, wherein the orientation control tube includes a position sensor that sends a signal indicating the orientation of the semi-tubular section relative to the anatomy of the body cavity.

12. The medical probe according to any one of the preceding claims, wherein blocking the refrigerant from leaving includes redirecting the refrigerant.

13. A method for manufacturing a medical probe, comprising: providing an insertion tube having a distal end configured for insertion into a body cavity and including a lumen that is open through the distal end; providing an inflatable balloon that can be deployed into the body cavity through the lumen; providing an injection tube that extends from the lumen into the balloon and includes a plurality of holes that are radially distributed around the injection tube and lead into the balloon and are configured to deliver refrigerant from the injection tube into the balloon; and providing an orientation control tube that surrounds the injection tube and is capable of rotating around the injection tube and moving longitudinally along the injection tube, and includes a semi-tubular section that is configured to cover one or more of the holes, thereby blocking the refrigerant from leaving through the one or more of the holes; wherein the semi-tubular section includes a plurality of sections having different blocking angles, and each of the sections is configured to cover a different corresponding number of holes.

14. The method according to claim 13, including providing a processor and a handle that is coupled to the insertion tube and has controls, and the processor adjusts the delivery of the refrigerant to the injection tube in response to signals received from the controls.

15. The method according to claim 13, including providing a processor and a handle that is coupled to the insertion tube and has controls, and the processor adjusts the extension of the orientation control tube over the holes in response to signals received from the controls.

16. The method according to claim 13, including providing a processor and a handle that is coupled to the insertion tube and has controls, and the processor adjusts the rotation of the orientation control tube relative to the anatomy of the body cavity in response to signals received from the controls.

17. The method according to claim 15, including providing a visual indicator on the handle, and the processor presents the degree of extension of the orientation control tube over the holes on the visual indicator.

18. The method according to claim 13, including providing a processor and a handle that includes controls that adjust the rotation of the orientation control tube around the injection tube.

19. The method according to claim 18, including providing a visual indicator on the handle, and the processor presents the angle of rotation of the orientation control tube around the injection tube on the visual indicator.

20. The method according to claim 13, wherein the semi-tubular section includes markers that are visible under fluoroscopy.

21. The method according to claim 13, wherein the orientation control tube includes a position sensor that sends a signal indicating the position of the semi-tubular section relative to the injection tube.

22. The method according to claim 13, wherein the orientation control tube includes a position sensor that sends a signal indicating the orientation of the semi-tubular section relative to the anatomical structure of the body cavity.

23. The method according to any one of claims 13-22, wherein blocking the refrigerant from leaving includes redirecting the refrigerant.

24. A medical probe, comprising: a tubular member extending from a proximal end to a distal end along a longitudinal axis; at least one inflatable membrane coupled to the tubular member between the proximal end and the distal end; an injection tube disposed within the at least one inflatable membrane, the injection tube having a plurality of holes angularly disposed around the injection tube to allow fluid to flow out of the plurality of holes into the at least one inflatable membrane; and a control tube disposed between the injection tube and the tubular member and capable of rotating around and longitudinally moving along the injection tube, the control tube having a plurality of arcuate sections disposed along the length of the control tube, wherein each arcuate section defines less than a complete circumference of the control tube such that some of the holes in the injection tube are exposed to the inflatable membrane depending on the orientation of the control tube relative to the injection tube.

25. The medical probe according to claim 24, wherein the injection tube includes a fixed member relative to the rotatable and translatable control tube.

26. The medical probe according to any one of claims 24-25, wherein at least one radiopaque marker is provided on at least one of the injection tube and the control tube to allow identification of the orientation of the injection tube relative to the control tube.

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