Basket catheter with balloon

Abstract

The invention is entitled "Basket Catheter with Balloon". In one embodiment, a catheter apparatus is configured to be inserted into a body portion of a living subject and comprises: an elongate deflectable member including a distal end; an expandable basket assembly disposed at the distal end and including a plurality of struts and a plurality of electrodes disposed on the struts; an irrigation channel disposed in the elongate deflectable member; and an inflatable balloon disposed in the expandable basket assembly and including a plurality of irrigation holes in fluid connection with the irrigation channel.

Description

Technical Field

[0001] This invention relates to medical devices, and specifically, but not exclusively, to catheters. Background Technology

[0002] Numerous medical procedures involve placing probes, such as catheters, inside a patient's body. Position sensing systems have been developed to track these probes. Magnetic position sensing is one method known in the art. In magnetic position sensing, a magnetic field generator is typically placed at a known location outside the patient's body. A magnetic field sensor within the distal end of the probe generates electrical signals in response to these magnetic fields; these signals are processed to determine the coordinate position of the distal end of the probe. These methods and systems are described in U.S. Patents 5,391,199, 6,690,963, 6,484,118, 6,239,724, 6,618,612, and 6,332,089, in PCT International Patent Publication WO 1996 / 005768, and in U.S. Patent Application Publications 2002 / 006455, 2003 / 0120150, and 2004 / 0068178. Impedance- or current-based systems can also be used to track position.

[0003] Treatment of arrhythmias is a medical procedure in which these types of probes or catheters have proven extremely useful. Arrhythmias, and specifically atrial fibrillation, have always been a common and dangerous medical condition, especially in the elderly.

[0004] The diagnosis and treatment of cardiac arrhythmias involve mapping the electrical properties of cardiac tissue, particularly the endocardium, and selectively ablating cardiac tissue by applying energy. Such ablation can stop or alter unwanted electrical signals propagating from one part of the heart to another. Ablation methods disrupt unwanted electrical pathways by creating a non-conductive ablation focus. Various forms of energy delivery for creating ablation focuses have been disclosed, including the use of microwaves, lasers, and more commonly, radiofrequency energy to create conduction blocks along the cardiac tissue walls. In a two-step procedure (mapping followed by ablation), electrical activity at various points within the heart is typically sensed and measured by advancing a catheter containing one or more electrical sensors into the heart and acquiring data at multiple points. This data is then used to select the target endocardial region for ablation.

[0005] Electrode catheters have been widely used in medical practice for many years. They are used to stimulate and map electrical activity in the heart, as well as to ablate sites of abnormal electrical activity. In use, the electrode catheter is inserted into a major vein or artery, such as the femoral vein, and then guided to the cardiac chamber of interest. A typical ablation procedure involves inserting a catheter with one or more electrodes at its distal end into the cardiac chamber. A reference electrode can be provided, typically by adhering it to the patient's skin, or a second catheter positioned in or near the heart can be used to provide a reference electrode. RF (radio frequency) current is applied between the catheter electrodes of the ablation catheter and an unrelated electrode (which may be one of the catheter electrodes), and the current flows through the medium between these electrodes (i.e., blood and tissue). The current distribution can depend on the amount of contact between the electrode surface and the tissue compared to blood, which has a higher conductivity than tissue. Heating of the tissue occurs due to its resistance. The tissue is sufficiently heated to destroy cells in the cardiac tissue, resulting in the formation of a non-conductive ablation focus within the cardiac tissue. In some applications, irreversible electroporation can be performed to ablate the tissue.

[0006] U.S. Patent Publication 2019 / 0117301 by Steinke et al. describes a catheter and catheter system for treating a patient's blood vessels, comprising an elongated, flexible catheter body with a radially expandable structure. As the structure expands, multiple electrodes or other electrosurgical energy delivery surfaces can radially engage the material to be treated. A material detector near the distal end of the catheter body measures the circumferential material distribution, and a power source selectively excites the electrodes to treat the body lumen eccentrically.

[0007] U.S. Patent 9,757,180 to Gelfand et al. describes systems, devices, and methods for treating patients with sympathetic-mediated diseases that are at least partially associated with enhanced peripheral chemoreceptors or intensified sympathetic activation. These treatments involve ablation of one or more peripheral chemoreceptors or associated afferent nerves to reduce or eliminate afferent nerve signals from the peripheral chemoreceptors.

[0008] U.S. Patent 9,474,486 to Eliason et al. describes an electrophysiological electrode conduit comprising an elongated deformable shaft having a proximal end and a distal end, and a basket-shaped electrode assembly coupled to the distal end of the shaft. The basket-shaped electrode assembly has a proximal end and a distal end and is configured to present a compressed state and an expanded state. The electrode assembly also includes one or more tubular ribs and a plurality of conductors having a plurality of electrodes disposed thereon. Each of the plurality of conductors extends through the tubular rib from a corresponding electrode of the plurality of electrodes to the proximal end of the basket-shaped electrode assembly. The tubular rib is configured to present a non-planar (e.g., twisted or spiral) shape in the expanded state.

[0009] U.S. Patent 9,060,756 to Bencini et al. describes a method for ablating body tissue, the method comprising: (a) positioning an inflatable balloon portion of a cryotherapy balloon catheter at a treatment site within a patient and inflating the inflatable balloon portion; (b) electrically characterizing the body tissue at the treatment site using electrodes disposed on an expandable surface of the inflatable balloon portion; (c) ablating the body tissue by supplying a cryotherapy agent to the inflatable balloon portion to cool the body tissue to a treatment temperature; (d) using electrodes to determine whether the ablation induced a desired electrical change in the body tissue; and (e) repeating (c) and (d) when it is determined that the ablation did not induce a desired electrical change.

[0010] U.S. Patent 10,362,952 to Basu et al. describes a catheter for diagnosing and ablating tissue, the catheter having a stable spinal electrode assembly. The stable spinal electrode assembly has at least two ridges fixed to the catheter body at their proximal ends and at least one tether fixed between distal positions of the proximal ends of adjacent ridges. The ridges have a collapsed arrangement and an expanded arrangement, in which the ridges are arranged generally along the longitudinal axis of the catheter body, and in the expanded arrangement, at least a portion of each ridge is radially outwardly bent from the longitudinal axis, and at least one tether applies tension to adjacent ridges. Summary of the Invention

[0011] According to embodiments of this disclosure, a catheter device is provided, configured for insertion into a body portion of a living subject, and includes: an elongated deflectable element including a distal end; an expandable basket assembly disposed at the distal end and including a plurality of ribs and a plurality of electrodes disposed on the ribs; a flushing channel disposed in the elongated deflectable element; and an inflatable balloon disposed in the expandable basket assembly and including a plurality of flushing orifices in fluid communication with the flushing channel.

[0012] In addition, according to the embodiments of this disclosure, the reinforcing bars are arranged circumferentially around the inflatable balloon.

[0013] Furthermore, according to an embodiment of this disclosure, the inflatable balloon is configured to be fully inflated such that there is a gap of at least one millimeter between the fully inflated balloon and at least 30 percent of the inner surface area of ​​the rib facing the inflatable balloon.

[0014] In addition, according to the embodiments of this disclosure, each rib in the ribs includes an inner surface and an outer surface, and the electrode is disposed on the inner surface and outer surface of the corresponding rib in the ribs.

[0015] Furthermore, according to embodiments of this disclosure, the inflatable balloon and the expandable basket assembly include a distal end, and the device further includes a support element connected to the distal end of the inflatable balloon and the distal end of the expandable basket assembly, and configured to maintain a gap of at least one millimeter between the fully inflated balloon and at least 30 percent of the inner surface region of the inflatable balloon facing the ribs facing the inflatable balloon.

[0016] In addition, according to the embodiments of this disclosure, the corresponding reinforcing bars in the reinforcing bars contain nitinol.

[0017] Furthermore, according to the embodiments of this disclosure, the electrodes in the corresponding ribs contain nitinol.

[0018] Furthermore, according to embodiments of this disclosure, the corresponding ribs in the ribs include corresponding polymer flexible circuits.

[0019] Furthermore, according to embodiments of this disclosure, at least 90 percent of the electrodes are disposed in the region of the expandable basket assembly, and at least 90 percent of the flushing holes of the inflatable balloon are disposed on the proximal or distal side of the region.

[0020] Additionally, according to embodiments of this disclosure, the electrodes are disposed in the region of the expandable basket assembly, and the flushing port of the inflatable balloon is disposed on the proximal or distal side of the region.

[0021] According to another embodiment of this disclosure, a catheter device is also provided, configured for insertion into a body portion of a living subject, and comprising: an elongated deflectable element including a distal end; an expandable basket assembly disposed at the distal end and including a plurality of ribs and a plurality of electrodes disposed on the ribs; and an inflatable balloon disposed in the expandable basket assembly and configured to be fully inflated such that a gap of at least one millimeter exists between the fully inflated balloon and at least 30 percent of the inner surface region of the ribs facing the inflatable balloon.

[0022] Furthermore, according to the embodiments disclosed herein, the reinforcing bars are arranged circumferentially around the inflatable balloon.

[0023] In addition, according to the embodiments of this disclosure, each rib in the ribs includes an inner surface and an outer surface, and the electrode is disposed on the inner surface and outer surface of the corresponding rib in the ribs.

[0024] Furthermore, according to embodiments of this disclosure, the inflatable balloon and the expandable basket assembly include a distal end, and the device further includes a support element connected to the distal end of the inflatable balloon and the distal end of the expandable basket assembly, and configured to maintain a gap of at least one millimeter between the fully inflated balloon and at least 30 percent of the inner surface region of the inflatable balloon facing the ribs facing the inflatable balloon.

[0025] In addition, according to the embodiments of this disclosure, the corresponding reinforcing bars in the reinforcing bars contain nitinol.

[0026] Furthermore, according to the embodiments of this disclosure, the electrodes in the corresponding ribs contain nitinol.

[0027] Furthermore, according to embodiments of this disclosure, the corresponding ribs in the ribs include corresponding polymer flexible circuits.

[0028] According to another embodiment of this disclosure, a medical system is provided, comprising a catheter and an ablation power generator configured to be connected to the catheter and to apply electrical signals to at least one electrode in the electrodes to ablate tissue of a body part, the catheter being configured to be inserted into a body part of a living subject, and comprising: an elongated deflectable element including a distal end; an expandable basket assembly disposed at the distal end and including a plurality of ribs and a plurality of electrodes disposed on the ribs; and an inflatable balloon disposed in the expandable basket assembly.

[0029] Furthermore, according to embodiments of this disclosure, the catheter includes a flushing channel disposed in an elongated deflectable element, and wherein the inflatable balloon includes a plurality of flushing holes that are fluidly connected to the flushing channel.

[0030] Additionally, according to embodiments of this disclosure, the inflatable balloon is configured to be fully inflated such that there is a gap of at least one millimeter between the fully inflated balloon and at least 30 percent of the inner surface area of ​​the rib facing the inflatable balloon.

[0031] Furthermore, according to the embodiments of this disclosure, each rib in the ribs includes an inner surface and an outer surface, and the electrode is disposed on the inner surface and outer surface of the corresponding rib in the ribs.

[0032] In addition, according to embodiments of this disclosure, at least 90 percent of the electrodes are disposed in the region of the expandable basket assembly, and at least 90 percent of the flushing holes of the inflatable balloon are disposed on the proximal or distal side of the region.

[0033] Furthermore, according to embodiments of this disclosure, the electrodes are disposed in the region of the expandable basket assembly, and the flushing port of the inflatable balloon is disposed on the proximal or distal side of the region.

[0034] In addition, according to embodiments of this disclosure, the ablation power generator is configured to apply an electrical signal between electrodes to perform irreversible electroporation on tissues of a body part. Attached Figure Description

[0035] The invention will be understood from the following detailed description taken in conjunction with the accompanying drawings, wherein:

[0036] Figure 1 A schematic diagram of a medical system constructed and operated according to an embodiment of the present invention;

[0037] Figure 2 A schematic diagram of a catheter constructed and operated according to an embodiment of the present invention;

[0038] Figure 3A for Figure 2 A sectional view of the conduit along line A:A;

[0039] Figure 3B for Figure 2 A cross-sectional view of an alternative embodiment of the device shown, wherein the balloon is not attached to the distal end of the basket-like member;

[0040] Figure 4 for Figure 3A A more detailed cross-sectional view of the conduit within box A;

[0041] Figure 5 for Figure 3A A more detailed cross-sectional view of the conduit within box B; and

[0042] Figure 6 A cross-sectional view of a catheter constructed and operated according to an alternative embodiment of the present invention. Detailed Implementation

[0043] Overview

[0044] Flushing is typically used with catheters to provide cooling during medical procedures such as radiofrequency (RF) ablation. One solution for providing flushing in basket catheters is to have a flushing channel pass through the catheter, terminating in the middle of the basket. Flushing fluid can then be pumped through the flushing channel to the distal end of the channel, where it exits and provides cooling and local blood dilution to the tissue in the area of ​​the basket. However, flushing is not well-directed, and while it may be sufficient for electroporation that does not generate significant heat, it is often insufficient to reduce the heat generated during RF ablation. Another problem with basket catheters is that the basket needs to be collapsed or semi-collapsed during insertion into the body and then deployed in its expanded form within the body cavity. The need to enable the basket to collapse and expand adds another challenge to providing effective flushing, as the flushing channel can interfere with the expansion and collapse of the basket. Another problem with basket catheters (whether used for ablation or diagnostics) is that blood clots have been found to form and remain in the basket during use.

[0045] Embodiments of the present invention address the aforementioned problems by providing a conduit having an expandable basket assembly comprising electrodes thereon, wherein an inflatable balloon is mounted within the expandable basket assembly. Upon deployment, the balloon inflates within the expanded basket assembly and serves to displace blood from the interior of the basket assembly to prevent the formation of blood clots within the basket assembly. Additionally, the balloon may include flushing ports through which flushing fluid is pumped to cool the electrodes during use. The balloon allows for strategic placement of the flushing ports relative to the electrodes to enhance cooling during use.

[0046] In some embodiments, a fully inflated balloon contacts the inner surface of an expanded basket assembly. When there is no gap or a very small gap between the fully inflated balloon and the inner surface of the expanded basket assembly, blood is prevented from entering the interior of the basket assembly, thereby preventing blood clots. In other embodiments, a gap exists between the fully inflated balloon and the inner surface of the expanded basket assembly. When a gap exists, the electrodes can be flushed more effectively (depending on flushing and electrode configuration), and the inner surface of the basket assembly can include electrodes, thereby increasing the electrode surface area available for ablation.

[0047] In some embodiments, the catheter includes an elongated deflectable element and an expandable basket assembly disposed at the distal end of the deflectable element. The basket assembly includes ribs and electrodes placed on the ribs. The catheter includes an inflatable balloon disposed within the expandable basket assembly, wherein the ribs are circumferentially arranged around the inflatable balloon.

[0048] In some embodiments, at least some of the ribs comprise nitinol. In some embodiments, the electrodes in the respective ribs comprise nitinol. For example, the nitinol ribs are selectively covered with an insulating cover to expose the electrodes, or the nitinol ribs are covered with windows in the cover to expose the electrodes. In other embodiments, the ribs comprise corresponding polymer flexible circuits. The flexible circuits can be supported using nitinol supports extending along at least a given length of each rib.

[0049] In some embodiments, the catheter includes a flushing channel disposed within an elongated deflectable element, and the inflatable balloon includes a flushing orifice in fluid communication with the flushing channel. In some embodiments, the electrodes are disposed in a region of an expandable basket assembly, and the flushing orifice of the inflatable balloon (when the balloon is fully inflated) is located more proximal to or more distal to the electrode region (when the basket assembly is fully expanded).

[0050] In some embodiments, the catheter includes a flushing channel disposed within an elongated deflectable element, and the inflatable balloon includes flushing orifices that are in fluid communication with the flushing channel. In some embodiments, at least 90 percent of the electrodes are disposed in the region of the expandable basket assembly, and at least 90 percent of the flushing orifices of the inflatable balloon (when the balloon is fully inflated) are disposed proximal to or distal to the electrode region (when the basket assembly is fully expanded).

[0051] In other embodiments, the inflatable balloon does not include a flushing port. In those embodiments, flushing may optionally be performed using other methods.

[0052] In some embodiments, the inflatable balloon is configured to be fully inflated such that a gap of at least one millimeter exists between the fully inflated balloon and at least a portion (e.g., at least 30 percent) of the inner surface region of the ribs (of the fully expanded basket assembly) facing the inflatable balloon. The balloon may optionally include a flushing port. In some embodiments, a support element is connected to the distal end of the inflatable balloon and the distal end of the expandable basket assembly, and maintains the gap between the fully inflated balloon and the ribs of the fully expanded basket assembly. In some embodiments, while maintaining the gap, electrodes may be disposed on the inner and outer surfaces of each rib, thereby increasing the electrode surface area for ablation. Electrodes on the inner surface may be integrated with or connected to electrodes on the outer surface. In some embodiments, the fully inflated balloon contacts the ribs.

[0053] The system may include an ablation power generator connected to a catheter and applying electrical signals to one or more electrodes to ablate tissue in a body part. In some embodiments, the ablation power generator applies electrical signals between the electrodes to perform irreversible electroporation on the tissue in the body part.

[0054] System Description

[0055] Now for reference Figure 1 This is a schematic diagram of a medical system 20 constructed and operated according to an embodiment of the present invention. System 20 includes a catheter 40 configured for insertion into a body portion of a living subject (e.g., patient 28). Physician 30 navigates the catheter 40 (e.g., a basket catheter manufactured by Biosense Webster, Inc., Irvine, California, USA) to a target location in the heart 26 of patient 28 by manipulating an elongation-deflectable element 22 of the catheter 40 and / or deflecting it from a sheath 23 using a manipulator 32 located near the proximal end of the catheter 40. In the illustrated embodiment, physician 30 uses the catheter 40 to perform electroanatomical mapping of the cardiac chambers and ablation of cardiac tissue.

[0056] The catheter 40 includes an expandable basket assembly 35 that is inserted through the sheath 23 in a folded configuration and only returns to its intended functional shape after the catheter 40 has been withdrawn from the sheath 23. By confining the basket assembly 35 in the folded configuration, the sheath 23 also serves to minimize vascular trauma en route to its target location.

[0057] The catheter 40 includes multiple electrodes 48 for sensing electrical activity and / or applying ablation power to ablate tissue in body parts. The catheter 40 may incorporate a magnetic sensor at the distal edge of the deflectable element 22 (i.e., at the proximal edge of the basket assembly 35). Figure 1 (Not shown in the image). Typically, although not required, but only by way of example, the magnetic sensor may be a triaxial sensor (TAS), a biaxial sensor (DAS), or a SAS, based on, for example, size considerations. A second magnetic sensor (not shown) may be included at any suitable location on assembly 35. The second magnetic sensor may be a TAS, DAS, or SAS, based on, for example, size considerations, only by way of example. The magnetic sensor and electrode 48 disposed on assembly 35 are connected to various drive circuits in console 24 via wires passing through deflectable element 22.

[0058] In some embodiments, system 20 includes a magnetic sensing subsystem to estimate the ellipticity of the basket assembly 35 of catheter 40 and its elongation / retraction state within the heart chambers of heart 26 by estimating the elongation of the basket assembly 35 from the distance between magnetic sensors. Patient 28 is placed in a magnetic field generated by a pad containing one or more magnetic field generator coils 42, driven by unit 43. The magnetic field generated by coils 42 transmits an alternating magnetic field to the area where the body part is located. The transmitted alternating magnetic field generates a signal in the magnetic sensors indicating position and / or orientation. The generated signal is transmitted to console 24 and becomes a corresponding electrical input to processing circuitry 41.

[0059] Position and / or orientation sensing methods using external magnetic fields and magnetic sensors are implemented in various medical applications, such as those produced by Biosense-Webster. The system is implemented and described in detail in U.S. Patents 5,391,199, 6,690,963, 6,484,118, 6,239,724, 6,618,612 and 6,332,089, PCT Patent Publication WO96 / 05768 and U.S. Patent Application Publications 2002 / 0065455A1, 2003 / 0120150A1 and 2004 / 0068178A1.

[0060] Processing circuitry 41 (typically part of a general-purpose computer) is further connected via suitable front-end and interface circuitry 44 to receive signals from body surface electrodes 49. Processing circuitry 41 is connected to body surface electrodes 49 via wires that pass through cable 39 and extend to the chest of patient 28.

[0061] In one embodiment, the processing circuit 41 presents a representation 31 of at least a portion of the catheter 40 and the calibrated body portion to the display 27 in response to the calculated position coordinates of the catheter 40.

[0062] The processing circuit 41 is typically programmed with software to perform the functions described herein. This software may be downloaded electronically to a computer via a network, or alternatively or additionally set and / or stored on a non-transitory tangible medium (such as magnetic storage, optical storage, or electronic storage).

[0063] The medical system 20 may also include an ablation power generator 69 (such as an RF signal generator) configured to be connected to the catheter 40 and to apply an electrical signal to the electrode 48. The medical system 20 may also include: a flushing reservoir 71 configured to store flushing fluid; and a pump 73 configured to be connected to the flushing reservoir 71 and the catheter 40 and to pump flushing fluid from the flushing reservoir 71 through the flushing tubing of the catheter 40, as referenced. Figure 2 Figure 3 and Figure 5 More details to follow.

[0064] Figure 1 The exemplary examples shown are chosen solely for the sake of conceptual clarity. For the sake of simplicity and clarity, Figure 1 Only elements relevant to the technology disclosed in this invention are shown. System 20 typically includes additional modules and elements that are not directly related to the disclosed technology, and therefore these additional modules and elements are derived from... Figure 1The corresponding descriptions are intentionally omitted. The elements of system 20 and the methods described herein can be further applied, for example, to control the ablation of tissues of the heart 26.

[0065] See now Figure 2 This is a schematic diagram of a catheter 40 constructed and operated according to an embodiment of the present invention.

[0066] The catheter 40 is configured to be inserted into a body part of a living subject (e.g., the heart 26). Figure 1 The deflectable element 22 of the catheter 40 has a distal end 33. The deflectable element 22 may be made of any suitable material, such as polyurethane or polyether block amide. Assembly 35 is disposed distal to the deflectable element 22 and may be connected to the deflectable element 22 via a proximal coupling member 50 at the distal end 33. The proximal coupling member 50 typically comprises a hollow tube and may be formed of any suitable material, such as, but not limited to, polycarbonate with or without glass filler, polyether ether ketone (PEEK) with or without glass filler, polyimide, polyamide, or polyether imide (PEI) with or without glass filler. The coupling member 50 may be formed as an integral part of the deflectable element 22, as part of the basket assembly 35, or as a separate element connected to both the deflectable element 22 and the basket assembly 35. As used herein, the term “distal” means the reference part is further away from the operator, while “proximal” means the reference part is closer to the operator of the catheter.

[0067] Component 35 may include multiple ribs 55 (only one is labeled for simplicity), such as flexible strips having electrodes 48 (some are labeled for simplicity) disposed on the ribs 55. Figure 2 In one embodiment, each rib 55 includes a single electrode 48. The assembly 35 may include any suitable number of electrodes 48, with each rib 55 having multiple electrodes 48.

[0068] In some embodiments, at least some of the ribs 55 comprise nitinol. In some embodiments, the electrodes 48 of the respective ribs 55 comprise nitinol. In other embodiments, the respective ribs 55 comprise a corresponding polymer flexible circuit. The flexible circuit can be supported using a nitinol support extending at least a certain length along each rib 55.

[0069] exist Figure 2In one embodiment, each rib 55 is formed of nitinol, selectively covered with insulating material in its distal and proximal regions 57 (some are marked for simplicity), leaving the central region 59 (some are marked for simplicity) of the rib 55 as an electroactive region for, for example, performing mapping and / or performing ablation or electroporation. The structure of component 35 can vary. For example, rib 55 (or other ribs) may comprise a flexible printed circuit board (PCB) or a shape memory alloy of any suitable shape.

[0070] In some implementations, the relaxed state of the basket assembly 35 is an extended deployment configuration. The basket assembly 35 is configured such that when the conduit 40 is in the sheath 23 ( Figure 1 The expandable basket assembly 35 collapses into a collapsed form when retracted and is configured to expand into an extended deployment form when the conduit 40 is removed from the sheath 23. The relaxed shape of the basket assembly 35 can be set by forming ribs 55 from any suitable elastic material such as nitinol or PEI. In other embodiments, the relaxed state of the expandable basket assembly 35 is a collapsed form, and the expandable basket assembly 35 is expanded by retracting a traction element (e.g., a traction wire) disposed along the length of the elongated deflectable element 22 and connected to the distal end of the expandable basket assembly 35.

[0071] The catheter 40 includes an inflatable balloon 65 disposed within an expandable basket assembly 35. Ribs 55 are generally arranged circumferentially around the inflatable balloon 65. Figure 2 In the illustrated embodiment, the inflatable balloon 65 is fully inflated such that it contacts the ribs 55 of the fully expanded expandable basket assembly 35 (90% or more along the length of each rib 55). (See reference...) Figure 6 In other embodiments described in more detail, there is a gap of at least 1 mm between the fully inflated balloon 65 and at least 30% of the inner surface area of ​​the ribs 55 of the fully extended expandable basket assembly 35.

[0072] In some embodiments, the catheter 40 includes a flushing channel 67 disposed within the elongated deflectable element 22. Figure 3A and 5 (As shown). In Figure 2 The illustrated embodiment shows an inflatable balloon 65 including a plurality of flushing holes 75. The flushing holes 75 are fluidly connected to a flushing channel 67. Figure 3A ).

[0073] In some embodiments, flushing holes 75 are located in one or more regions of the inflatable balloon 65. In other embodiments, flushing holes 75 are located on the inflatable balloon 65. In some embodiments, flushing holes 75 are primarily located in regions of the inflatable balloon 65 not close to the electrodes 48. In some embodiments, electrodes 48 are located in a given region of the expandable basket assembly 35, and when the inflatable balloon 65 and the expandable basket assembly 35 are fully extended, the flushing holes 75 of the inflatable balloon 65 are located more proximal to or more distal to the given region (relative to a plane perpendicular to the axis of the non-deflecting conduit 40). In some embodiments, at least ninety percent of the electrodes 48 are located in a given region of the expandable basket assembly 35, and when the inflatable balloon 65 and the expandable basket assembly 35 are fully extended, at least ninety percent of the flushing holes 75 of the inflatable balloon 65 are located more proximal to or more distal to the given region (relative to a plane perpendicular to the axis of the non-deflecting conduit 40).

[0074] In other embodiments, the inflatable balloon 65 does not include a flushing port. In these embodiments, flushing may optionally be performed using any suitable method.

[0075] Ablation power generator 69 ( Figure 1 The ablation power generator 69 is configured to connect to the catheter 40 and apply electrical signals to at least one of the electrodes 48 (e.g., between two or more electrodes 48, or between one or more electrodes 48 and a proximal electrode 77 disposed at the distal end of the elongated deflectable element 22, or with a reference electrode) to ablate tissue of a body part (e.g., the heart 26). In some embodiments, the ablation power generator 69 is configured to apply electrical signals between one or more electrodes 48 to perform irreversible electroperforation of the tissue of the body part. The inflatable balloon 65 helps prevent electrical signals from being primarily conducted through the center of the expandable basket assembly 35, instead enhancing the conduction of electrical signals through the tissue of the body part.

[0076] The inflatable balloon 65 may comprise a biocompatible material such as polyurethane, polyether block amide, silicone, nylon, or polyester. Typically, the balloon will have a wall thickness of 0.0005” to 0.005”. The flushing holes 75 may have any suitable diameter, for example, in the range of about 0.01 mm to 0.125 mm, such as 0.075 mm. The inflatable balloon 65 may include any suitable number of discrete holes 75, for example, 1 to 200, such as 50. In some embodiments, the flushing holes 75 may comprise laser- or mechanically drilled holes.

[0077] Pump 73 ( Figure 1 ) is configured to deliver flushing fluid from flushing reservoir 71 ( Figure 1 ) via flushing channel 67 ( Figure 3AThe fluid is pumped into the inflatable balloon 65 and through the flushing port 75. The flushing fluid is used to inflate the inflatable balloon 65. In embodiments where the inflatable balloon 65 does not include a flushing port, the inflatable balloon 65 can be inflated with any suitable fluid such as saline or gas.

[0078] Now for reference Figure 3A , it is Figure 2 A sectional view of the conduit 40 along line A:A. Figure 3A (Inside box A) shows the distal ends (only two are labeled for simplicity) of the inflatable balloon 65 and the rib 55, which are folded over and connected to the distal connector 85. In some embodiments, the distal connector is a tube (e.g., a polymer tube) or a strip (e.g., a polymer strip). Reference Figure 4 The distal connector 85 is described in more detail.

[0079] In some embodiments, the rib 55 and / or the inflatable balloon 65 can be connected to the distal connector 85 without folding over, such that when the basket assembly 35 collapses, the rib 55 approaches a flat formation along its length.

[0080] Figure 3A (Inside box B) is shown the proximal end of rib 55 connecting to the inner surface of proximal coupling member 50. The proximal end of inflatable balloon 65 connects to proximal connector 79 (e.g., polymer insert), which is secured to proximal coupling member 50. Reference Figure 5 The proximal connector 79 is described in more detail. Figure 3A Also shown is a flushing channel 67 (which extends through a slot 83 in the deflectable element 22, the proximal coupling member 50 and the proximal connector 79) and a position sensor 81 (e.g., a magnetic position sensor).

[0081] exist Figure 3B The diagram shows an alternative catheter tip actuator 40' having a balloon 65' arranged such that the distal balloon portion 65a is not fixed or coupled to the distal catheter connector 85. That is, the balloon 65' has a free distal balloon portion 65a (i.e., not connected to the distal connector 85), wherein the proximal balloon portion 65b is coupled to the proximal connector 50, such that the balloon 65' freely conforms to the inner boundary of the catheter ridge 55. Figure 3B In what ways does the 65' balloon in the middle compare with... Figure 3A The balloon in the middle is different from that in the 65.

[0082] Now for reference Figure 4 , it is Figure 3AA more detailed cross-sectional view of the conduit 40 inside frame A. Rib 55 is secured to distal connector 85. The distal end of inflatable balloon 65 is secured between rib 55 and distal retaining ring 87. An adhesive or epoxy layer 89 is disposed between distal retaining ring 87 and distal connector 85, thereby securing rib 55 and inflatable balloon 65 in place. In some embodiments, inflatable balloon 65 and rib 55 may be secured between distal connector 85 and distal retaining ring 87 using pressure fitting and / or any suitable adhesive. Distal connector 85 and proximal retaining ring 87 may be formed of any suitable material, such as, but not limited to, polycarbonate with or without glass filler, PEEK with or without glass filler, or PEI with or without glass filler. Distal connector 85 also serves as a insert to plug the distal end of inflatable balloon 65.

[0083] Now for reference Figure 5 , it is Figure 3A or Figure 3B A more detailed sectional view of the conduit 40 inside frame B.

[0084] Figure 5 A proximal connector 79 and a slot 83 are shown. Slot 83 allows a flushing channel 67-3 and wires (e.g., for connection to one or more electrodes and / or sensors) to traverse the proximal connector 79. A flushing channel 67-2 connects to flushing channel 67-3, the latter being narrower to fit within slot 83. An inflatable balloon 65 is attached to the proximal connector 79 using, for example, adhesive. The inflatable balloon 65 can be attached to the proximal connector 79 using any suitable connection method.

[0085] The proximal end of the rib 55 is secured between the proximal connecting member 50, the position sensor 81, and the flushing channel 67-2. The rib 55 can be secured to the proximal connecting member 50 using pressure fitting and / or any suitable adhesive. The flushing channel 67-2 is connected to the flushing channel 67-1 disposed in the elongated deflectable element 22.

[0086] The proximal connector 79 may be formed of any suitable material, such as, but not limited to, polycarbonate with or without glass filler, PEEK with or without glass filler, or PEI with or without glass filler.

[0087] See now Figure 6 This is a cross-sectional view of a catheter 100 constructed and operated according to an alternative embodiment of the present invention. The catheter 100 differs from the following: Figures 1 to 5 The catheter 40 is basically the same.

[0088] The catheter 100 includes an inflatable balloon 102 configured to be fully inflated such that a gap 104 of at least one millimeter exists between the fully inflated balloon 102 and at least a portion (e.g., at least 30 percent) of the inner surface region of the rib 55 facing the inflatable balloon 102. The “inner surface” is defined as the surface of the rib 55 facing the inflatable balloon 102.

[0089] In some embodiments, the inflatable balloon 102 includes a flushing port (not shown). In other embodiments, the inflatable balloon 102 does not include a flushing port.

[0090] In some embodiments, the catheter 100 includes support elements, such as a distal connector 85 (and / or a proximal connector 79) connected to the distal end of the inflatable balloon 102 and the distal end of the expandable basket assembly 35, which are configured to maintain a gap 104 of at least one millimeter between the fully inflated balloon 102 and the inner surface region of the rib 55 facing at least a portion (e.g., at least 30 percent) of the inflatable balloon 102.

[0091] In some embodiments, electrodes 48 are disposed on the inner and outer surfaces of a corresponding rib in rib 55. The use of the inner and outer surfaces of electrodes 48 provides a larger surface area for ablation. One of the electrodes 48 disposed on the inner surface of one of the ribs 55 may be electrically connected to a corresponding electrode 48 on the outer surface of that rib 55. In some embodiments, a single electrode may extend from the inner surface to the outer surface (e.g., when the rib 55 is formed of a conductor such as nitinol).

[0092] As used herein, the term “about” or “approximately” for any numerical value or range indicates appropriate dimensional tolerances that allow a collection of parts or components to achieve the intended purpose as described herein. More specifically, “about” or “approximately” may refer to a range of values ​​±20% of the listed values; for example, “about 90%” may refer to a range of values ​​from 72% to 108%.

[0093] For clarity, the various features of the invention described in the context of individual embodiments may also be provided in combination in a single embodiment. Conversely, for brevity, the various features of the invention described in the context of individual embodiments may also be provided individually or in any suitable sub-combination.

[0094] The above embodiments are cited by way of example, and the invention is not limited to the specific examples shown and described above. Rather, the scope of the invention includes combinations and sub-combinations of the various features described above, as well as variations and modifications thereof, which will occur to those skilled in the art upon reading the above description and are not disclosed in the prior art.

Claims

1. A catheter device configured for insertion into a body portion of a living subject, and comprising: An elongated deflectable element, the elongated deflectable element including a distal end; An expandable basket assembly is disposed at the distal end and includes a plurality of ribs and a plurality of electrodes disposed on the ribs; A flushing channel is disposed in the elongated deflectable element; and An inflatable balloon is disposed in the expandable basket assembly and includes a plurality of flushing holes fluidly connected to the flushing channel, wherein at least 90 percent of the electrodes are disposed in a region of the expandable basket assembly, and at least 90 percent of the flushing holes of the inflatable balloon are disposed on the proximal or distal side of the region.

2. A catheter device configured for insertion into a body portion of a living subject, the device comprising: An elongated deflectable element, the elongated deflectable element including a distal end extending along a longitudinal axis; An expandable basket assembly is configured near the distal end and includes a plurality of ribs extending from the distal end of the deflectable element to a distal ridge connector and a plurality of electrodes disposed on the ribs; A flushing channel is disposed in the elongated deflectable element; and An inflatable balloon, disposed within the expandable basket assembly, the inflatable balloon including a proximal balloon portion coupled to the distal end and a detachable distal balloon portion near the distal ridge connector, the inflatable balloon including a plurality of flushing holes fluidly connected to the flushing channel, wherein at least 90 percent of the electrodes are disposed in a region of the expandable basket assembly, and at least 90 percent of the flushing holes of the inflatable balloon are disposed proximal or distal to the region.

3. The device according to claim 1 or 2, wherein the ribs are arranged circumferentially around the inflatable balloon.

4. The device according to claim 1 or 2, wherein the inflatable balloon is configured to be fully inflated such that there is a gap of at least one millimeter between the fully inflated balloon and at least 30 percent of the inner surface region of the rib facing the inflatable balloon.

5. The device according to claim 4, wherein each of the ribs comprises an inner surface and an outer surface, and the electrode is disposed on the inner surface and the outer surface of the respective rib.

6. The device of claim 4, wherein the inflatable balloon and the expandable basket assembly include distal ends, the device further comprising a support element connected to the distal ends of the inflatable balloon and the distal ends of the expandable basket assembly, the support element being configured to maintain a gap of at least one millimeter between the fully inflated balloon and at least 30 percent of the inner surface region of the rib facing the inflatable balloon.

7. The device of claim 1, wherein the respective ribs in the ribs comprise nitinol.

8. The device of claim 7, wherein the electrode of the respective rib comprises nitinol.

9. The device according to claim 1, wherein each of the ribs comprises a corresponding polymer flexible circuit.

10. The device of claim 1, wherein the electrode is disposed in a region of the expandable basket assembly, and the flushing port of the inflatable balloon is disposed on a more proximal or more distal side of the region.

11. A catheter device configured for insertion into a body portion of a living subject, and comprising: An elongated deflectable element, the elongated deflectable element including a distal end; An expandable basket assembly is disposed at the distal end and includes a plurality of ribs and a plurality of electrodes disposed on the ribs; A flushing channel is disposed in the elongated deflectable element; and An inflatable balloon is disposed within the expandable basket assembly and configured to be fully inflated such that a gap of at least one millimeter exists between the fully inflated balloon and at least 30 percent of the inner surface region of the ribs facing the inflatable balloon, wherein the ribs are circumferentially arranged around the inflatable balloon, the inflatable balloon including a plurality of flushing holes fluidly connected to the flushing channels, wherein at least 90 percent of the electrodes are disposed in the region of the expandable basket assembly, and at least 90 percent of the flushing holes of the inflatable balloon are disposed on the proximal or distal side of the region.

12. The device of claim 11, wherein each of the ribs comprises an inner surface and an outer surface, and the electrode is disposed on the inner surface and the outer surface of the respective rib.

13. The device of claim 11, wherein the inflatable balloon and the expandable basket assembly include distal ends, the device further comprising a support element connected to the distal ends of the inflatable balloon and the distal ends of the expandable basket assembly, the support element being configured to maintain a gap of at least one millimeter between the fully inflated balloon and at least 30 percent of the inner surface region of the rib facing the inflatable balloon.

14. The device of claim 11, wherein the respective ribs in the ribs comprise nitinol.

15. The device of claim 14, wherein the electrode of the respective rib comprises nitinol.

16. The device of claim 11, wherein each of the ribs comprises a corresponding polymer flexible circuit.

17. A medical system, the medical system comprising: A catheter configured for insertion into a body part of a living subject, and comprising: An elongated deflectable element, the elongated deflectable element including a distal end; An expandable basket assembly is disposed at the distal end and includes a plurality of ribs and a plurality of electrodes disposed on the ribs; A flushing channel is disposed in the elongated deflectable element; and An inflatable balloon, disposed within the expandable basket assembly, the inflatable balloon including a plurality of flushing holes fluidly connected to the flushing channel, wherein at least 90 percent of the electrodes are disposed in a region of the expandable basket assembly, and at least 90 percent of the flushing holes of the inflatable balloon are disposed proximal to or distal to the region; and An ablation power generator configured to be connected to the catheter and to apply an electrical signal to at least one of the electrodes to ablate tissue in the body part.

18. The system of claim 17, wherein the inflatable balloon is configured to be fully inflated such that there is a gap of at least one millimeter between the fully inflated balloon and at least 30 percent of the inner surface region of the rib facing the inflatable balloon.

19. The system of claim 17, wherein each of the ribs includes an inner surface and an outer surface, and the electrode is disposed on the inner surface and the outer surface of the respective rib.

20. The system of claim 17, wherein the electrode is disposed in a region of the expandable basket assembly, and the flushing port of the inflatable balloon is disposed on a more proximal or more distal side of the region.

21. The system of claim 17, wherein the ablation power generator is configured to apply an electrical signal between the electrodes to perform irreversible electroporation on the tissue of the body part.

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