Irrigated electrophysiology balloon catheter

Abstract

To provide an electrophysiology catheter.SOLUTION: An electrophysiology catheter includes a balloon that may be expanded with an irrigation liquid, and that can have the irrigation liquid removed more quickly therefrom than other catheter balloons having a similar volume and without damaging electrical componentry disposed on the balloon. The catheter includes a shaft assembly comprising a shaft-assembly lumen, a choke lumen, and ports that connect the shaft-assembly lumen to an interior of the balloon. A guide wire may be disposed in the choke lumen to divert irrigation liquid into the balloon via the ports, which expands the balloon. Upon removal of the guide wire from the choke lumen, irrigation liquid can exit the balloon through the ports and then exit the catheter via its distal tip.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims priority under 35 U.S.C. § 119 to U.S. Provisional Patent Application No. 63 / 612,709, filed on December 20, 2023. This application also relates to the subject matter described in U.S. Patent Application No. 15 / 360,966, filed on November 23, 2016, and later issued as U.S. Patent No. 10,660,700. The entire contents of these applications are hereby incorporated by reference in their entirety.

[0002] (Field of the Invention) The subject matter disclosed herein relates to ablation systems, particularly ablation systems that include a catheter capable of ablating cardiac tissue.

Background Art

[0003] Ablation of cardiac tissue can be used in the treatment of cardiac arrhythmias. Ablation energy can be provided to cardiac tissue by structures such as electrodes disposed on the distal portion of a catheter. Some catheters have their electrodes disposed or incorporated into a three - dimensional structure, such as a wire basket and a balloon.

Summary of the Invention

Means for Solving the Problems

[0004] The electrophysiology catheter includes a balloon that can be inflated with an irrigation fluid and can remove the irrigation fluid from the balloon more quickly and without damaging electrical components disposed on the balloon than other catheter balloons having a similar volume. The electrophysiology catheter includes a shaft assembly having a plurality of tubular components, each of the plurality of tubular components having a respective wall, and the respective walls together defining an interior of the shaft assembly including a shaft assembly lumen. A first tubular component of the plurality of tubular components includes a first shaft having a first shaft wall forming a first wall of the respective walls, a proximal portion of the first shaft, a distal portion of the first shaft, and a lumen of the first shaft extending through the first shaft and forming a first portion of the interior of the shaft assembly. A second tubular component of the plurality of tubular components includes a second shaft having a second shaft wall forming a second wall of the respective walls, a proximal portion of the second shaft, a distal portion of the second shaft, and a lumen of the second shaft extending through the second shaft and forming a second portion of the interior of the shaft assembly. The second shaft is connected to the first shaft such that the distal portion of the first shaft is disposed distal to the distal portion of the second shaft and the proximal portion of the first shaft. A third tubular component of the plurality of tubular components includes a tip having a tip wall forming a third wall of the respective walls, a proximal portion of the tip, a distal portion of the tip, and a tip lumen extending through the tip and forming a third portion of the interior of the shaft assembly. The tip is connected to the first shaft such that the distal portion of the tip is disposed distal to the distal portion of the first shaft and the proximal portion of the tip.

[0005] The choke region is disposed within the shaft assembly lumen. The choke region has a choke lumen, and the choke lumen has a choke width that is smaller than a portion of the width of the shaft assembly lumen located proximal to the choke lumen. The balloon defines an internal volume, is connected to the shaft assembly, with the proximal portion of the balloon connected to the distal portion of a second shaft and the distal portion of the balloon connected to the distal portion of a first shaft.

[0006] The ports are located inside the balloon, are disposed through respective walls, and define a proximal passage between the interior of the shaft assembly and the internal volume of the balloon. The ports may be disposed through the wall of the first shaft, and the lumen of the first shaft defines at least a portion of the choke lumen. Alternatively or additionally, the ports may also be disposed through the tip wall, and a portion of the tip lumen defines at least a portion of the choke lumen.

[0007] Another catheter, such as a guide wire or a mapping catheter providing a guide wire function, may be disposed through the shaft assembly lumen. The guide wire or other catheter has a width equal to or approximately equal to the width of the choke lumen. When the guide wire is disposed within the choke lumen, the perfusion fluid supplied into the shaft assembly from a perfusion pump fills the balloon and pressurizes the balloon into an expanded configuration. When the guide wire is not disposed within the choke lumen, the perfusion fluid contained within the balloon returns into the shaft assembly lumen via at least one of the ports and can then exit out through the tip of the electrophysiology catheter. Thus, by the operation of pulling the electrophysiology catheter into the guide catheter lumen of the guide catheter, the guide catheter compresses the balloon and squeezes the liquid contained therein into the shaft assembly and out of the tip of the electrophysiology catheter.

Brief Description of the Drawings

[0008] This specification concludes with claims that particularly point out and distinctly claim the subject matter described herein, which subject matter will be better understood from the following description of certain embodiments taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements.

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[0009] The following detailed description should be read with reference to the drawings, and like elements in different drawings are numbered the same. The drawings are not necessarily to scale, depict selected embodiments, and are not intended to limit the scope of the invention. The detailed description is illustrative, not limiting, and is intended to illustrate the principles of the invention by way of example. This description enables those skilled in the art to make and use the invention and describes some embodiments, adaptations, variations, alternatives, and uses of the invention, including what is currently considered to be the best mode of carrying out the invention.

[0010] As used herein, the terms "about" or "substantially" with respect to any numerical value or numerical range indicate a preferred dimensional tolerance that enables a part or collection of parts to function for its intended purpose as described herein. More specifically, "about" or "substantially" may refer to a range of values within ±10% of the recited value; for example, "about 90%" may refer to a range of values from 81% to 99%. Further, as used herein, the terms "patient," "host," "user," and "subject" refer to any human or animal subject, and while use of the invention in human patients represents a preferred embodiment, the system or method is not intended to be limited to use in humans.

[0011] Description of the System Figure 1 is a schematic diagram of an invasive medical procedure using device 12. This procedure is performed by medical professional 14, and by way of example, the procedure in the following description is assumed to include ablation of a portion of the myocardium 16 of the heart of human patient 18. However, it is understood that the embodiments disclosed herein are not applicable only to this particular procedure and may substantially include any procedure on biological tissue or non-biological material.

[0012] To perform the ablation, medical professional 14 inserts probe or guide catheter 20 into sheath 21 pre-positioned in the lumen of the patient. Sheath 21 is positioned such that the distal end of guide catheter 20 enters the patient's heart. Diagnostic / therapeutic or electrophysiology catheter 24, which will be described in more detail below with reference to FIG. 2, is deployed through the lumen of guide catheter 20 and is adapted to exit from the distal end of guide catheter 20.

[0013] As shown in FIG. 1, device 12 is controlled by system processor 22 within the device's operation console 24, which is also schematically indicated by reference numeral 15. Console 24 includes control unit 26 and screen 28 that can be used by medical professional 14 to communicate with the processor. Thus, screen 28 may comprise a touch screen and control unit 26 may comprise, for example, a mouse or trackball. During the procedure, processor 22 typically tracks the position and orientation of the distal end of guide catheter 20 using any method known in the art. For example, processor 22 can use a magnetic tracking method, and magnetic transmitters 25X, 25Y, and 25Z external to patient 18 generate signals within a coil positioned at the distal end of guide catheter 20. The CARTO® system (available from Biosense Webster, Inc. (Irvine, California)) uses such a tracking method.

[0014] The software for the processor 22 can be downloaded to the processor in electronic form via a network, for example. Alternatively or additionally, the software may be provided on a non-transitory tangible medium such as an optical, magnetic, or electronic storage medium. Tracking of the distal end of the guide catheter 20 can be displayed on the three-dimensional display 30 of the patient 18's heart on the screen 28. However, it may be displayed two-dimensionally, for example, by fluoroscopy or MRI.

[0015] To operate the device 12, the processor 22 communicates with a memory 32 having a number of modules used by the processor to operate the device. Thus, the memory 32 includes a temperature module 34, an ablation module 36, and an infusion module 38. The infusion module 38 can be connected to a pump, thereby enabling the processor to control the pump and thus to control the flow rate of the infusion fluid provided to the catheter. The memory 32 typically includes other modules such as a force module for measuring the force on the distal end of the guide catheter 20, a tracking module for operating the tracking method used by the processor 22, an electrocardiograph (ECG) module, etc. For simplicity, such other modules are not shown in FIG. 1. The modules can include hardware elements and software elements.

[0016] FIG. 2 is a schematic perspective view of an electrophysiology catheter 24 with the balloon 40 in an expanded configuration. The catheter 24 may include a handle 39, such as a knob 42 and a control unit 44, which can be used to assist in the operation and positioning of the balloon 40. A tube 46 extends proximally from the handle 39, through which a perfusion fluid, such as saline, can be pumped. Another catheter or a guide wire 48, such as a mapping catheter, can also be inserted through the electrophysiology catheter 24 via the tube 46 or alternatively through another tube 50 (FIG. 8A). If a single tube 46 extends proximally from the handle 39, the tube 46 may branch into two legs 46A and 46B, and this branch may be provided by a Y connector 52. In this case, one of the legs 46A and 46B may be connected to a perfusion pump, and the guide wire 48 is disposed through the other leg.

[0017] As schematically shown in FIGS. 3 - 5, when the electrophysiology catheter 24 is used to ablate the fenestration 11 in a lumen, such as the pulmonary vein 13, the balloon 40 is supported on a shaft assembly 54. The shaft assembly is tubular, and thus, its various components are also tubular. As shown, the shaft assembly 54 includes at least a first or inner shaft 56 having a distal portion 58 and a proximal portion 60 of the first shaft, and a second or outer shaft 62 having a distal portion 64 and a proximal portion of the second shaft. The shaft assembly 54 may further include a tip 68 having a proximal tip portion 70 and a distal tip portion 72. The shaft assembly 54 may also include a proximal collar 74, a distal collar 76, and a connector 78 having a connector distal portion 84 and a connector proximal portion 86.

[0018] The first shaft 56 and the second shaft 62 are connected to each other, either directly or indirectly. For example, an indirect connection between the first shaft 56 and the second shaft 62 may be achieved by directly connecting the proximal portion 60 of the first shaft to the connector distal portion 84 and directly connecting the distal portion 64 of the second shaft to the connector proximal portion 86. These direct connections may be made using at least one of an adhesive and welding.

[0019] Similarly, the balloon 40 may be connected, either directly or indirectly, to the distal portion 64 of the second shaft at its proximal end 80 and to the distal portion 60 of the first shaft at its distal end 82. For example, an indirect connection may be achieved by connecting the balloon proximal end 80 to the distal portion 64 of the second shaft via a connector 78, such as by using one or more of an adhesive, welding, or a proximal collar 74 that compresses the balloon proximal portion 80 onto the connector 78. Similarly, the balloon distal portion 82 may be connected to the distal portion 58 of the first shaft via a tip 68, such as by using one or more of an adhesive, welding, or a distal collar 76 that compresses the distal end 82 onto the tip 68.

[0020] The balloon 40 of the electrophysiology catheter 24 has an outer wall, surface, or membrane 88 of a biocompatible material formed from a plastic such as, for example, polyethylene terephthalate (PET), polyurethane, or PEBAX®. The shaft assembly 54 defines the longitudinal axis 90 of the catheter 40. The balloon 40 is deployed in a folded configuration through the lumen 92 of the guide catheter 20 and can be expanded by pressurizing it with a perfusion fluid after it exits the distal end, as will be described in detail later. In the case of the balloon 40 intended to be deployed for use in the ostium 11 of the pulmonary vein, the balloon, when expanded, has an elliptical shape, for example, a spherical shape. The balloon 40 may have a diameter of from about 25 millimeters to about 35 millimeters, for example, about 30 millimeters. The membrane 88 of the balloon 40 may be formed with perfusion holes or perfusion ports 94 through which fluid (e.g., saline) can exit from the inside of the balloon 40 to the outside of the balloon to cool the tissue ablation site at the ostium.

[0021] The membrane 88 supports and carries a combined electrode and temperature sensing member, each constructed as a multilayer flexible circuit electrode assembly 96. The "flexible circuit electrode assembly" 96 can have many different geometric configurations. In the illustrated embodiment, the flexible circuit electrode assembly 96 has a plurality of radial substrates or strips 98 on which electrodes 99 are disposed. In the embodiment reflected in the figure, there is one electrode 99 disposed on each of the substrates 98. Thus, for example, if the balloon 40 includes 10 substrates, it also includes 10 electrodes. The substrates 98 are uniformly distributed around the balloon 40. Each substrate has a wider proximal portion from which it tapers gradually towards a narrower distal portion. Further, each substrate extends between the balloon proximal end 80 and the balloon distal end 82.

[0022] Fluid Management After balloon 40 is positioned inside the heart adjacent to or within the ostium 11 of the pulmonary vein, the perfusion pump is activated via perfusion module 36 to provide a perfusion fluid, such as saline, through electrophysiology catheter 24 from tube 46 into the internal volume 41 of balloon 40. The pump can provide a first flow rate or a lower flow rate of the perfusion fluid and a second flow rate or a higher flow rate. The lower flow rate can be, for example, about 0 mL / min to about 10 mL / min, about 2 mL / min to about 5 mL / min, such as about 3.5 mL / min. The higher flow rate is more than the lower flow rate and can be, for example, about 10 mL / min to 50 mL / min, about 25 mL / min to about 35 mL / min, such as about 30 mL / min. Initially, the lower flow rate is provided while the balloon remains in its folded configuration. Increasing the flow rate to the higher flow rate causes pressure to accumulate within the internal volume 41 of balloon 40, and balloon 40 expands to assume the spherical shape shown. After the balloon expands from its folded configuration to its expanded spherical configuration, the perfusion fluid can exit out of the opening 94 as either droplets or a jet, as shown in FIG. 4.

[0023] Once ablation at a particular location is complete, balloon 40 is moved to another location in the heart or removed from the heart. Both of these operations typically require reducing the flow rate of the perfusion fluid to a lower rate, folding balloon 40, and pulling it into guide catheter 20. However, to fold balloon 40 and pull it into the guide catheter, it is necessary to drain a sufficient amount of perfusion fluid from balloon internal volume 41 to avoid damaging balloon 40 or its electrical components. Typically, perfusion fluid is drained from internal volume 41 by slowly pulling balloon 40 into guide catheter 20 so that the tip of the guide catheter presses against membrane 88, squeezing the balloon and forcing the perfusion fluid out of internal volume 41 through opening 94. Applicants have determined that when the lower flow rate is about 5 mL / min, the inflated balloon has a diameter of about 30 mm, and the balloon design includes openings 94 of sufficient size and number to produce a jet of perfusion fluid exiting through opening 94 when the perfusion fluid is being pumped at a higher flow rate of about 25 mL / min to about 35 mL / min, it takes about 30 seconds to drain the perfusion fluid from the internal volume by pressing balloon 40 against the tip of guide catheter 20 and simultaneously pulling balloon 40 into guide catheter 20, and attempting to drain the perfusion fluid more quickly by pulling balloon 40 more rapidly into guide catheter 20 may damage balloon 40 and its electrical components. Since balloon 40 may need to be pulled into the guide catheter about 5 to about 15 times, for example 10 times, during a given procedure, Applicants have identified that reducing the time it takes to drain the perfusion fluid from internal volume 41 and pull balloon 40 into the guide catheter is a good opportunity to improve the design and use of electrophysiology catheter 24. Accordingly, Applicants have conducted research and development efforts in accordance with this opportunity and present the following exemplary solutions embodied in shaft assembly 54.

[0024] Figures 6A-6C, 7A-7C, and 8 show center plane cross-sections of the shaft assembly 54 as shown in FIG. 5 and are diagrams for detailing small and internal features of the shaft assembly. The cutting plane is parallel to the plane of the paper including FIG. 5 and includes the axis 90 as shown by the cutting plane X-X. In Figures 6A-6C, 7A-7C, and 8, the guide catheter 20, collar 74, and collar 76 are hidden, but the balloon 40 is shown in a truncated form with its distal portion 82 and its proximal portion 80 remaining visible. Starting with Figures 6A-6C, the shaft assembly 54 includes a plurality of tubular components connected to each other, namely, a first shaft 56, a second shaft 62, a tip 68, and a connector 78. Since these components are tubular, each has an outer wall and a lumen. As shown, the first shaft 56 includes a first shaft wall 55 that defines an interior 56i of the first shaft with a lumen 57 of the first shaft, the second shaft 62 includes a second shaft wall 61 that defines an interior 62i of the second shaft with a lumen 63 of the second shaft, and the tip 68 includes a tip wall 67 that defines a tip interior 68i and a tip lumen 69. The interior of the first shaft, the interior of the second shaft, and the tip interior together form respective portions of the interior of the shaft assembly through which the shaft assembly lumen 59 passes. In other words, the first shaft wall 55, the second shaft wall 61, and the tip wall 67 define the interior of the shaft assembly 54, and the lumen 57 of the first shaft, the lumen 63 of the second shaft, and the tip lumen 69 constitute the shaft assembly lumen 59 within the interior of the shaft assembly 54. As seen in FIG. 6B, the guide wire 48 can pass completely through the shaft assembly lumen 59. Further, the first shaft 56 may be disposed entirely inside the balloon 40.

[0025] The connection between the first shaft 56 and the second shaft 62 is made such that the distal portion 58 of the first shaft is disposed distal to the distal portion 64 of the second shaft and the proximal portion 60 of the first shaft. A connector 78 may be used to facilitate this connection, and the connection is made by inserting the proximal portion 60 of the first shaft inside the distal portion of the connector 78 and inserting the distal portion 64 of the second shaft into the proximal portion of the connector 78 and securing them therein, for example, using glue or epoxy. In this way, the first shaft 56 and the second shaft 62 are indirectly connected to each other via their direct connection to the connector 78. Additionally, the balloon proximal portion 80 is connected to the distal portion of the connector 78, for example, directly connected by a collar 74.

[0026] Similarly, the connection between the first shaft 56 and the tip 68 is made such that the tip distal portion 70 is disposed distal to the distal portion 58 of the first shaft and the tip proximal portion 72. The distal portion 58 of the first shaft is disposed within the tip proximal portion 72 and secured directly therein, for example, with glue or epoxy. Additionally, the balloon distal portion 82 is connected to the tip 68, for example, directly connected by a collar 76.

[0027] Various ports are also disposed through the components of the shaft assembly 54. As shown in FIGS. 6A-6C, at least one port 102 is disposed through the wall 55 of the first shaft and into the interior of the balloon 40, and two examples thereof are illustrated. Thus, the port 102 provides a passage between the lumen 57 of the first shaft and the interior 41 of the balloon. Further, at least one port 104 is disposed through the wall 61 of the second shaft, and a connector port 106 is disposed through the connector 78 and aligned with the port 104. The ports 104 and 106 are disposed within the balloon 40, and together they provide a passage between the lumen 63 of the second shaft and the interior 41 of the balloon. Thus, the ports 102, 104, and 106 provide a passage for the irrigation fluid to pass between the interior volume 41 of the balloon 40 and the shaft assembly lumen 59. The port 102 so oriented may be referred to as a distal port, and the port 104, or the ports 104 and 106, may be referred to as proximal ports.

[0028] The shaft assembly lumen 59 also includes a choke region 108. As shown in FIGS. 6A-6C, the choke region 108 is located at the distal portion 58 of the first shaft. The choke region 108 has a choke lumen 110, and the choke lumen 110 has a choke width W1 that is smaller than a partial width W2 of the shaft assembly lumen 59 located proximal to the choke region 108. Thus, as shown in FIGS. 6A-6C, the choke lumen 110 includes a portion of the lumen 57 of the first shaft, and that portion has a width smaller than the remaining portion of the lumen 57 of the first shaft. The guide wire 48 should have a width W3 that is equal to or slightly smaller than the width W1, such that the guide wire 48 can easily pass through the choke lumen 110. W1 may be from about 0.90 mm to about 1.25 mm, for example, about 1.0 mm. W2 may be from 1.0 mm to about 1.75 mm, for example, about 1.25 mm, and should be greater than W1. W3 may be from about 0.85 mm to about 0.95 mm, for example 0.91 mm, and should be less than or equal to W1.

[0029] As shown in FIGS. 6A and 6C, when the guide wire 48 is not disposed within the choke lumen 110, the perfusion fluid flows through the shaft assembly lumen 59, through at least one of the ports 102 and 104, and into the volume 41, and may also exit out of the distal end 68 through the choke lumen 110. Since the perfusion fluid can flow out of the distal end 68, the perfusion fluid cannot maintain the internal pressure within the balloon 40 suitable for ablation procedures using the electrode 99, or generate a jet of perfusion fluid through the opening 94, even when pumped at a higher (or lower) flow rate. However, when the guide wire 48 is disposed within the choke lumen 110, the perfusion fluid cannot pass through the choke lumen 110 or is substantially restricted from passing through it. Thus, when the guide wire 48 is disposed within the choke lumen 110, the perfusion fluid being pumped at a higher flow rate can maintain the internal pressure within the balloon suitable for ablation procedures using the electrode 99 and can also generate a jet of perfusion fluid through the opening 94.

[0030] This configuration of the shaft assembly 54 thus enables shortening of the duration required to fold the balloon 40 from its expanded configuration and draw it into the guide catheter 20. That is, while the guide wire 48 is disposed within the choke lumen 110, by providing the perfusion fluid at a higher flow rate, after the balloon 40 has been pressurized into its expanded / spherical configuration, the flow rate can be decreased to a lower flow rate, and the guide wire 48 can be displaced in the proximal direction, for example to the position shown in FIG. 6C. From there, by drawing the balloon 40 into the guide catheter 20, the balloon 40 is contracted towards its folded configuration, which squeezes the perfusion fluid within the internal volume 41 from the port 102 and restricts or prevents any perfusion fluid being pumped at a lower flow rate from entering the internal volume 41 through the ports 102 and 104. Instead, the perfusion fluid flows through the choke lumen 110 and exits out of the distal end 68.

[0031] Referring to FIGS. 7A - 7C, another configuration of the shaft assembly 54 is illustrated. This configuration is similar to the configuration described with respect to FIGS. 6A - 6C, except for the following: 1) The choke region 108 and the choke lumen 110 are provided at the distal end portion 68. 2) The distal end portion 68 includes a distal port 112 disposed proximal to the proximal of the choke region 108 (two are illustrated) and within the balloon 40. Thus, in this configuration, at least one of the ports 102 and 104 functions as a proximal port that is proximal to the choke region 108 and the distal port 112, which means that the distal port 112 can also be referred to as the distal port. Similarly, since the choke region 108 is provided at the distal distal portion 70, the choke lumen 110 constitutes at least a part of the distal lumen 69. Further, the proximal proximal portion 72 is directly connected to the distal portion of the first shaft, for example, with glue or epoxy.

[0032] Referring to FIG. 8, another configuration of the shaft assembly 54 is illustrated. This configuration is similar to the configuration described with respect to FIGS. 6A - 6C, except that in FIG. 8, in addition to the lumen 63 of the second shaft, a second lumen 65 of the second shaft is provided. The second lumen 65 of the second shaft provides a passage for the guide wire 48 and is not connected to a perfusion pump for receiving perfusate. Thus, as seen in FIG. 8A, the two tubes 46 and 50 extend in the proximal direction from the handle 39. The tube 46 is still connected to the lumen 63 of the first and second shafts and remains connectable to the perfusion fluid pump, while the tube 50 is connected to the lumen 65 of the second shaft.

[0033] The foregoing description relates to a design in which the choke width W1 of the choke lumen 110 is selected based on the width of the guide wire 48. However, the guide wire 48 typically has a uniform or nominally uniform cross-section along its length. However, a catheter, particularly a mapping catheter, may have a non-uniform cross-section with a greater width along at least one longitudinal portion than another longitudinal portion. To facilitate the use of a non-uniform device, such as a non-uniform catheter or a non-uniform guide wire, advanced through the catheter 24, a seal that can adapt to the movement of the non-uniform device and that can maintain a seal against portions of the non-uniform device having different widths even when the non-uniform device is being moved relative to the seal may be incorporated at the tip.

[0034] For example, referring to FIGS. 9A-9D, the tip portion 168 may include a seal 170. The seal 170 may be disposed within the choke lumen 111 that forms part of the tip lumen 169 as shown. For example, the tip portion 168 may include a cavity 176 within which the seal 170 is disposed and attached to the tip portion 168, for example, by adhering it therein with an adhesive. As shown, the seal 170 includes a wiper seal, i.e., a tubular seal having a constriction 172 disposed within a lumen 173 that defines a bore 174 having a bore width W. The non-uniform device 148 includes at least one minimum width portion 178 and one maximum width portion 180 and can be advanced, disposed, and retracted through the seal bore 174. At least the constriction 172 should be positioned distally relative to the tip port 112, which is the most distal port of the catheter, although the entire seal 170 may be positioned distally relative to the tip port 112. Of course, if the proximal portion of the seal 170 extends proximally of the tip port 112, the seal 170 should include a port that is aligned with the distal tip port 112 such that fluid can pass between the internal volume 41 of the balloon 24 and the shaft assembly lumen 59.

[0035] The contact between the seal 170 and the non-uniform device 148 can be maintained while the non-uniform device is moved through the bore 174 of the constriction 172. Thus, as long as the non-uniform device 148 and the constriction 172 are in contact with each other, the seal between the seal 170 and the non-uniform device 148 is maintained. However, since the subject matter presented herein is aimed at enabling the user to fold the balloon 40 more quickly, a complete seal is not necessary as long as the fluid flow through the bore 174 is sufficiently restricted while the non-uniform device 148 is disposed therein, for the purposes of expansion and generation of a jet of perfusion fluid to achieve a desired pressure inside the balloon 40. Thus, the width W4 of the bore 174 may be equal to or slightly larger than the minimum width of the non-uniform device 148, i.e., the width of the minimum width portion 178 of the non-uniform device 148. Suitable exemplary dimensions include, for a non-uniform device 148 having a minimum width, i.e., a range of the same dimensions of the width of the minimum width portion 178, e.g., from about 0.38 mm to about 0.95 mm, e.g., about 0.60 mm, a width of the bore 174 from about 0.38 mm to about 0.95 mm, e.g., about 0.60 mm. The constriction 172 should be adaptable and bendable to allow a portion of the non-uniform device 148 having a width greater than the minimum width of the bore 174 (which can include the entire non-uniform device including the minimum width portion 178) to pass through the bore 174 of the constriction 172. Thus, the seal 170 should be made of a material including an elastomer (e.g., medical grade silicone or urethane) having a Shore A durometer hardness of about 25 to about 40.

[0036] Shaft assembly 54 may include other port configurations that allow the balloon 40 to be pressurized while the guide wire 48 is disposed through the choke lumen 110, and then, particularly while the guide wire 48 is not disposed within the choke lumen 110, the liquid contained within the balloon 40 can easily or quickly flow out of the balloon 40 into the shaft assembly lumen 59 and from the tip 68 in response to compressing the balloon 40 relative to the tip of the guide catheter 20 while retracting the balloon 40 into the lumen 92 of the guide catheter 20. For example, at 112, any number of ports 102, 104 may be provided, and in some configurations, only one or two of these ports may be sufficient to achieve the design goals. Conversely, in some cases, additional ports may need to be provided. Any design decisions regarding the number and placement of ports should be determined based at least on the perfusion flow rate used, the diameter of the ports, the size of the balloon, and the speed at which the balloon 40 should be folded. For example, the diameter of any of the ports 102, 104, and 112 may be about 0.4 mm to 0.8 mm, such as 0.6 mm.

[0037] By the embodiments illustrated and described herein, the applicant has devised a method and variations thereof for using an electrophysiology catheter (e.g., catheter 24) having a balloon (e.g., balloon 40) disposed at a distal portion. In this method and variations, the perfusion fluid within the balloon can be quickly discharged from the balloon so that the balloon can be quickly retracted into the guide catheter without damaging either the balloon or any electrical components of the balloon. This method is illustrated as method 200 in the flowchart of FIG. 10.

[0038] Method 200 begins with step 202 which includes placing the distal portion of the guiding catheter near the target position within the human heart. In step 204, the distal portion of the electrophysiology catheter with balloon 40 is extended out of the guiding catheter with the balloon in its folded configuration. In step 206, perfusion is initiated by operating a perfusion pump using a perfusion module. If the perfusion pump is operated before the electrophysiology catheter is extended out of the guiding catheter, the pump should be set to a lower flow rate. However, after the balloon is disposed outside the guiding catheter, the perfusion pump is set to a higher flow rate.

[0039] In step 208, the balloon is expanded to its expanded elliptical configuration. Thus, to explain these variations in the case where the pump is operated to pump at a lower flow rate while the balloon is disposed within the guiding catheter, step 208 further includes step 208a of checking that the pump is set to provide the perfusion fluid at a higher flow rate and, if not, setting it so. Next, in step 208b, a guide wire or a part of a non-uniform device (e.g., a mapping catheter) is disposed within the choke lumen. This blocks or restricts the flow of the perfusion fluid from the tip of the catheter shaft assembly. Thus, all or most of the perfusion fluid entering the shaft assembly lumen must enter the internal volume of the balloon through the ports of the shaft assembly. This pressurizes the balloon to an expanded elliptical configuration, resulting in a jet of perfusion fluid exiting from the opening of the balloon.

[0040] In step 210, ablation treatment can be provided to heart tissue by operating the electrode using an ablation module. In step 212, the perfusion pump is set to pump the perfusion fluid at a lower flow rate. In step 214, which begins about 0 seconds to about 5 seconds after step 212 is completed, the guide wire is withdrawn distally such that no portion of the guide wire remains within the choke lumen.

[0041] In step 216, the electrophysiology catheter is retracted into the guide catheter such that the tip of the guide catheter compresses the balloon, and thus, a portion of the perfusion fluid inside the balloon is caused to flow back into the shaft assembly lumen through at least the most distal port of the shaft assembly, i.e., either port 104 as shown in FIGS. 6A - 6C or port 112 as shown in FIGS. 7A - 7C. The perfusion fluid can also flow back into the shaft assembly lumen through any other port, depending, for example, on the flow rate used and the size of the port. Thus, due to the continuous compression of the balloon caused by retracting the balloon into the guide catheter, the perfusion fluid inside the balloon ultimately flows out of the shaft assembly through the catheter tip. Eventually, the entire balloon is retracted into the guide catheter, at which point the balloon has also returned to its folded configuration. For a balloon having an expanded spherical configuration with a diameter of about 25 mm to about 35 mm, step 216 can be completed in less than about 15 seconds (e.g., about 5 seconds to about 15 seconds) after step 214 is completed without damaging the balloon or its electrical components. In step 218, the medical professional determines whether to provide additional ablation treatment from the balloon. If so, some or all of the aforementioned steps starting from step 204 are repeated. If not, in step 220, the method ends by removing the electrophysiology catheter and the guide catheter from the patient's heart.

[0042] Any of the examples or embodiments described in this specification can include various other features in addition to or instead of those described above. The teachings, expressions, embodiments, examples, etc. described in this specification should not be considered in isolation from each other. Various suitable ways of combining the teachings of this specification should be apparent to those skilled in the art in view of the teachings of this specification.

[0043] Exemplary embodiments of the subject matter included in this specification have been illustrated and described, but further adaptations of the methods and systems described in this specification can be achieved by appropriate modifications without departing from the scope of the claims. Further, if the above methods and steps indicate specific events occurring in a particular order, the specific steps need not be performed in the order described, and the steps are intended to be performed in any order as long as the embodiments can function for their intended purposes. Accordingly, this patent is intended to encompass variations within the scope of the spirit of this disclosure or equivalent to the invention found in the claims as long as such variations exist. Some such modifications should be apparent to those skilled in the art. For example, the above examples, embodiments, geometric shapes, materials, dimensions, ratios, steps, etc. are illustrative. Accordingly, the claims should not be limited to the specific details of the structures and operations described in the specification and drawings.

[0044] 〔Embodiment〕 (1) An electrophysiology catheter, A shaft assembly, A plurality of tubular components each having a wall, the respective walls collectively defining an interior of the shaft assembly that includes a shaft assembly lumen, the plurality of tubular components; A first tubular component among the plurality of tubular components, comprising a first shaft, the first shaft including a wall of the first shaft that forms a first wall among the respective walls, a proximal portion of the first shaft, a distal portion of the first shaft, and a lumen of the first shaft that extends through the first shaft and forms a first portion of the interior of the shaft assembly, the first tubular component; A second tubular component among the plurality of tubular components, comprising a second shaft, the second shaft including a wall of the second shaft that forms a second wall among the respective walls, a proximal portion of the second shaft, a distal portion of the second shaft, and a lumen of the second shaft that extends through the second shaft and forms a second portion of the interior of the shaft assembly, the second shaft being connected to the first shaft such that the distal portion of the first shaft is disposed distal to the distal portion of the second shaft and the proximal portion of the first shaft, the second tubular component; A choke region disposed within the shaft assembly lumen and including a choke lumen, the choke lumen having a choke width that is smaller than a width of a portion of the shaft assembly lumen located proximal to the choke lumen, the choke region; A shaft assembly comprising; A balloon defining an internal volume and connected to the shaft assembly, a proximal portion of the balloon being connected to the distal portion of the second shaft and a distal portion of the balloon being connected to the distal portion of the first shaft, the balloon; A proximal port located inside the balloon and disposed through one of the respective walls, the proximal port defining a proximal passage between the interior of the shaft assembly and the internal volume of the balloon, and A distal port located inside the balloon and disposed through one of the respective walls or another of the respective walls, the distal port defining a proximal passage between the interior of the shaft assembly and the interior volume of the balloon, an electrophysiology catheter comprising the distal port. (2) The width of the portion of the shaft assembly lumen disposed proximal to the choke lumen is from about 1.0 mm to about 1.75 mm, the electrophysiology catheter according to embodiment 1. (3) A third tubular component of the plurality of tubular components comprises a tip, the tip including a tip wall forming a third wall of the respective walls, a proximal tip portion, a distal tip portion, and a tip lumen extending through the tip and forming a third portion of the interior of the shaft assembly, the tip being connected to the first shaft such that the distal tip portion is disposed distal to the distal portion of the first shaft and the proximal tip portion. The electrophysiology catheter according to embodiment 1. (4) The proximal tip portion is directly connected to the distal portion of the first shaft, the electrophysiology catheter according to embodiment 3. (5) The distal port is disposed through the wall of the first shaft, the electrophysiology catheter according to embodiment 3.

[0045] (6) The lumen of the first shaft defines at least a portion of the choke lumen, the electrophysiology catheter according to embodiment 5. (7) The distal port is disposed through the tip wall, the electrophysiology catheter according to embodiment 5. (8) The tip lumen defines at least a portion of the choke lumen, the electrophysiology catheter according to embodiment 3. (9) A method of using the electrophysiology catheter according to embodiment 1, Actuating a perfusion pump; Flowing liquid from the perfusion pump while a portion of a guide wire is disposed within the choke lumen; Expanding the balloon using the liquid such that the balloon has an elliptical configuration; After the operation of expanding the balloon, displacing the guide wire in the proximal direction such that a portion of the guide wire is not disposed within the choke lumen; After the operation of displacing the guide wire in the proximal direction, retracting the electrophysiology catheter into the guide catheter lumen of the guide catheter; A method comprising. (10) The operation of retracting the electrophysiology catheter into the guide catheter lumen includes compressing the balloon against the distal end of the guide catheter such that at least a portion of the liquid within the balloon is pushed into the distal port and extruded from the distal tip portion, the method according to embodiment 9.

[0046] (11) The operation of flowing the liquid into the internal volume of the balloon includes pumping the liquid at a volumetric flow rate of about 10 mL / min to about 50 mL / min, the method according to embodiment 10. (12) Further comprising reducing the flow rate to a lower flow rate before the operation of retracting the electrophysiology catheter into the guide catheter lumen, the method according to embodiment 11. (13) The operation of retracting the electrophysiology catheter into the guide catheter lumen is started within about 0 seconds to about 5 seconds after the operation of reducing the volumetric flow rate, the method according to embodiment 12. (14) The elliptical configuration of the balloon is spherical and has a diameter of about 25 mm to about 35 mm, and the operation of completely disposing the balloon within the guide catheter lumen is completed in less than about 15 seconds after the operation of reducing the volumetric flow rate, the method according to embodiment 12. (15) An electrophysiology catheter, A shaft assembly, A plurality of tubular components each having a wall, wherein the respective walls collectively define the interior of the shaft assembly including a shaft assembly lumen, the plurality of tubular components; A first tubular component of the plurality of tubular components, comprising a first shaft, the first shaft comprising a wall of the first shaft that forms a first wall of the respective walls, a proximal portion of the first shaft, a distal portion of the first shaft, and a lumen of the first shaft that extends through the first shaft and forms a first portion of the interior of the shaft assembly, the first tubular component; A second tubular component of the plurality of tubular components, comprising a second shaft, the second shaft comprising a wall of the second shaft that forms a second wall of the respective walls, a proximal portion of the second shaft, a distal portion of the second shaft, and a lumen of the second shaft that extends through the second shaft and forms a second portion of the interior of the shaft assembly, the second shaft being connected to the first shaft such that the distal portion of the first shaft is disposed distal to the distal portion of the second shaft and the proximal portion of the first shaft, the second tubular component; A choke region disposed within the shaft assembly lumen, comprising a choke lumen having a choke width and a seal disposed within the choke lumen, the choke region; A shaft assembly comprising; A balloon defining an internal volume connected to the shaft assembly, the proximal portion of the balloon being connected to the distal portion of the second shaft and the distal portion of the balloon being connected to the distal portion of the first shaft, the balloon; A proximal port located inside the balloon and disposed through one of the respective walls, the proximal port defining a proximal passage between the interior of the shaft assembly and the internal volume of the balloon, and A distal port located inside the balloon and disposed through one of the respective walls or another of the respective walls, the distal port defining a proximal passage between the interior of the shaft assembly and the interior volume of the balloon. An electrophysiology catheter comprising.

[0047] (16) The electrophysiology catheter according to embodiment 15, wherein the seal has a tubular form and includes a seal lumen. (17) The electrophysiology catheter according to embodiment 16, wherein the width of the portion of the shaft assembly lumen disposed proximal to the choke lumen is from about 1.0 mm to about 1.75 mm. (18) The electrophysiology catheter according to embodiment 16, wherein a constriction within the seal lumen defines a bore. (19) The electrophysiology catheter according to embodiment 18, wherein the constriction is disposed distal to the distal port. (20) The electrophysiology catheter according to embodiment 18, wherein the width of the bore is from about 0.38 mm to about 0.95 mm.

[0048] (21) The electrophysiology catheter according to embodiment 15, wherein the seal includes an elastomer having a Shore A durometer hardness of about 25 to about 40. (22) The electrophysiology catheter according to embodiment 15, wherein the seal includes a wiper seal. (23) The electrophysiology catheter according to embodiment 22, wherein the distal port is disposed through the tip wall. (24) A third tubular component of the plurality of tubular components has a tip, the tip including a tip wall forming a third wall of the respective walls, a proximal tip portion, a distal tip portion, and a tip lumen extending through the tip and forming a third portion of the interior of the shaft assembly, the tip being connected to the first shaft such that the distal tip portion is disposed distal to the distal portion of the first shaft and the proximal tip portion. The electrophysiology catheter according to embodiment 15. (25) The electrophysiology catheter according to embodiment 23, wherein the choke lumen includes at least a part of the tip lumen, and the seal is disposed on a part of the choke lumen including at least the part of the tip lumen.

Claims

1. 1. An electrophysiology catheter comprising:

1. A shaft assembly comprising: a plurality of tubular components having respective walls, the respective walls collectively defining an interior of the shaft assembly including a shaft assembly lumen; a first tubular component of the plurality of tubular components comprising a first shaft, the first shaft including a first shaft wall forming a first one of the respective walls, a first shaft proximal portion, a first shaft distal portion, and a first shaft lumen extending through the first shaft and forming the interior first portion of the shaft assembly; a second tubular component of the plurality of tubular components comprising a second shaft, the second shaft including a second shaft wall forming a second one of the respective walls, a proximal portion of a second shaft, a distal portion of a second shaft, and a second shaft lumen extending through the second shaft and forming a second portion of the interior of the shaft assembly, the second shaft being connected to the first shaft such that a distal portion of the first shaft is disposed distal to the distal portion of the second shaft and the proximal portion of the first shaft; a choke region disposed within the shaft assembly lumen, the choke region including a choke lumen, the choke lumen having a choke width that is less than a width of a portion of the shaft assembly lumen proximal to the choke lumen; a shaft assembly comprising: a balloon defining an interior volume connected to the shaft assembly, a proximal portion of the balloon connected to a distal portion of the second shaft and a distal portion of the balloon connected to a distal portion of the first shaft; a proximal port located inside the balloon and disposed through one of the respective walls, the proximal port defining a proximal passageway between the interior of the shaft assembly and the interior volume of the balloon; and a distal port located inside the balloon and disposed through the one of the respective walls or another of the respective walls, the distal port defining a proximal passageway between the interior of the shaft assembly and the interior volume of the balloon.

2. The electrophysiology catheter of claim 1 , wherein the width of the portion of the shaft assembly lumen located proximally to the choke lumen is between about 1.0 mm and about 1.75 mm.

3. 2. The electrophysiology catheter of claim 1, wherein a third tubular component of the plurality of tubular components comprises a tip including a tip wall forming a third one of the respective walls, a tip proximal portion, a tip distal portion, and a tip lumen extending through the tip forming a third portion of the interior of the shaft assembly, the tip being connected to the first shaft such that the tip distal portion is disposed distal to the distal portion of the first shaft and the tip proximal portion.

4. The electrophysiology catheter of claim 3 , wherein the tip proximal section is directly connected to the first shaft distal section.

5. The electrophysiology catheter of claim 3 , wherein the distal port is disposed through a wall of the first shaft.

6. The electrophysiology catheter of claim 5 , wherein the first shaft lumen defines at least a portion of the choke lumen.

7. The electrophysiology catheter of claim 5 , wherein the distal port is disposed through the tip wall.

8. The electrophysiology catheter of claim 3 , wherein the tip lumen defines at least a portion of the choke lumen.

9. 1. An electrophysiology catheter comprising:

1. A shaft assembly comprising: a plurality of tubular components having respective walls, the respective walls collectively defining an interior of the shaft assembly including a shaft assembly lumen; a first tubular component of the plurality of tubular components comprising a first shaft, the first shaft including a first shaft wall forming a first one of the respective walls, a first shaft proximal portion, a first shaft distal portion, and a first shaft lumen extending through the first shaft and forming the interior first portion of the shaft assembly; a second tubular component of the plurality of tubular components comprising a second shaft, the second shaft including a second shaft wall forming a second one of the respective walls, a proximal portion of a second shaft, a distal portion of a second shaft, and a second shaft lumen extending through the second shaft and forming a second portion of the interior of the shaft assembly, the second shaft being connected to the first shaft such that a distal portion of the first shaft is disposed distal to the distal portion of the second shaft and the proximal portion of the first shaft; a choke region disposed within the shaft assembly lumen, the choke region including a choke lumen having a choke width and a seal disposed within the choke lumen; a shaft assembly comprising: a balloon defining an interior volume connected to the shaft assembly, a proximal portion of the balloon connected to a distal portion of the second shaft and a distal portion of the balloon connected to a distal portion of the first shaft; a proximal port located inside the balloon and disposed through one of the respective walls, the proximal port defining a proximal passageway between the interior of the shaft assembly and the interior volume of the balloon; and a distal port located inside the balloon and disposed through the one of the respective walls or another of the respective walls, the distal port defining a proximal passageway between the interior of the shaft assembly and the interior volume of the balloon; An electrophysiology catheter comprising:

10. The electrophysiology catheter of claim 9 , wherein the seal has a tubular configuration and includes a seal lumen.

11. The electrophysiology catheter of claim 10, wherein a width of the portion of the shaft assembly lumen located proximally to the choke lumen is between about 1.0 mm and about 1.75 mm.

12. The electrophysiology catheter of claim 10 , wherein a constriction in the seal lumen defines a bore.

13. The electrophysiology catheter of claim 12 , wherein the constriction is disposed distal to the distal port.

14. The electrophysiology catheter of claim 12, wherein the bore width is from about 0.38 mm to about 0.95 mm.

15. The electrophysiology catheter of claim 9 , wherein the seal comprises an elastomer having a durometer of about 25 to about 40 Shore A.

16. The electrophysiology catheter of claim 9 , wherein the seal comprises a wiper seal.

17. The electrophysiology catheter of claim 16 , wherein the distal port is disposed through the tip wall.

18. 10. The electrophysiology catheter of claim 9, wherein a third tubular component of the plurality of tubular components comprises a tip, the tip including a tip wall forming a third one of the respective walls, a tip proximal portion, a tip distal portion, and a tip lumen extending through the tip forming a third portion of the interior of the shaft assembly, the tip connected to the first shaft such that the tip distal portion is disposed distal to the distal portion of the first shaft and the tip proximal portion.

19. 18. The electrophysiology catheter of claim 17, wherein the choke lumen includes at least a portion of the tip lumen, and the seal is disposed in a portion of the choke lumen that includes at least the portion of the tip lumen.

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