CN116965911A

CN116965911A - System and device for improving irrigation flow during cardiac surgery

Info

Publication number: CN116965911A
Application number: CN202310477365.2A
Authority: CN
Inventors: K·M·奥卡斯基; A·巴; T·阮; K·达塔
Original assignee: Biosense Webster Israel Ltd
Current assignee: Biosense Webster Israel Ltd
Priority date: 2022-04-28
Filing date: 2023-04-28
Publication date: 2023-10-31

Abstract

The disclosed technology includes a spine retention hub for a basket-type catheter. The ridge retention hub may comprise a cylindrical member comprising a plurality of first flushing openings; a first portion at a distal end of the ridge retention hub and having a first diameter; a second portion adjacent to the first portion and having a curved section with a first radius of curvature in a longitudinal direction; and a third portion proximate the second portion at a proximal end of the ridge retention hub and having a third diameter approximately three times the first diameter, the third portion further comprising a plurality of relief grooves and a plurality of brackets. Each bracket may be disposed at a proximal end of the spine retention hub, overlap a portion of a respective relief groove, and may be configured with the respective relief groove to receive and retain the respective spine section.

Description

System and device for improving irrigation flow during cardiac surgery

Technical Field

The present invention relates generally to medical devices, and in particular to catheters with electrodes and ridge retention hubs with irrigation openings, and further but not exclusively to catheters suitable for inducing irreversible electroporation (IRE) of cardiac tissue.

Background

Arrhythmia, such as Atrial Fibrillation (AF), may occur when areas of heart tissue abnormally conduct electrical signals to adjacent tissue. This can disrupt the normal cardiac cycle and lead to arrhythmia. Certain protocols are used to treat cardiac arrhythmias, including surgically disturbing the source of the signals responsible for the arrhythmia and disturbing the conduction pathways for such signals. By selectively ablating cardiac tissue by applying energy through the catheter, it is sometimes possible to stop or alter the propagation of unwanted electrical signals from one portion of the heart to another.

Many current ablation methods in the art tend to utilize Radio Frequency (RF) electrical energy to heat tissue. RF ablation may have certain drawbacks such as an increased risk of thermal cell damage, which may lead to charring of tissue, burns, steam pops, phrenic nerve paralysis, pulmonary vein stenosis, and esophageal fistulae. Cryoablation is an alternative to RF ablation, which generally reduces the thermal risk associated with RF ablation. However, manipulating a cryoablation device and selectively applying cryoablation is generally more challenging than RF ablation; thus, cryoablation is not feasible in certain anatomical geometries that may be reached by an electrical ablation device.

Some ablation methods use irreversible electroporation (IRE) to ablate cardiac tissue using non-thermal ablation methods. IRE delivers short pulses of high pressure to the tissue and produces unrecoverable cell membrane permeabilization. The use of multi-electrode catheters to deliver IRE energy to tissue has previously been proposed in the patent literature. Examples of systems and devices configured for IRE ablation are disclosed in U.S. patent publication Nos. 2021/0169550A1, 2021/0169567A1, 2021/0169568A1, 2021/0161592A1, 2021/0196372A1, 2021/0177503A1 and 2021/0186604A1, each of which is incorporated herein by reference and attached in the appendix of the parent application 63/336,127.

Areas of cardiac tissue may be mapped by the catheter to identify abnormal electrical signals. Ablation may be performed using the same or different catheters. Some example catheters include a plurality of ridges on which electrodes are disposed. The electrodes are typically attached to the ridges and secured in place by brazing, welding, or using an adhesive. Further, the plurality of linear ridges are typically assembled together by attaching both ends of the linear ridges to a tubular shaft (e.g., a push tube) to form a ballbasket.

However, due to the smaller size of the ridges and electrodes, adhering the electrodes to the ridges, and then forming the ball basket from multiple linear ridges can be a difficult task, increasing manufacturing time and cost, and increasing the chance of failure of the electrodes due to improper bonding or misalignment. In addition, these cardiac procedures generate heat at the electrodes, which can cause the patient to be injured. Accordingly, what is needed are systems and devices for an improved spine retention hub with improved flushing capabilities to effectively dissipate heat from basket catheters and medical probes having spine retention hubs and basket assemblies that generally help reduce the time required to manufacture basket assemblies and alternate catheter geometries.

Disclosure of Invention

According to one embodiment of the present invention, a spine retention hub for a basket-type catheter that may include a cylindrical member is provided. The cylindrical member may include a first portion having a first diameter at a distal end of the spine retention hub; a second portion proximate the first portion and having a curved section with a first radius of curvature in the longitudinal direction, wherein the first radius of curvature is approximately half the first diameter. The cylindrical member may also include a third portion proximate the second portion at the proximal end of the ridge retention hub and having a third diameter approximately three times the first diameter. The third portion of the cylindrical member may include a plurality of relief grooves and a plurality of brackets. Each bracket may be disposed at the proximal end of the ridge retention hub and overlap a portion of a corresponding relief groove of the plurality of relief grooves. Additionally, each bracket may be configured with a respective relief groove to receive and retain a respective ridge section. The cylindrical member may further comprise a plurality of first irrigation openings, each first irrigation opening being proximate the distal end of the ridge retention hub.

The plurality of first flushing openings can include six openings, which can be aligned with the plurality of relief grooves.

Each of the plurality of first openings may comprise about 0.05mm ² To about 0.6mm ² Is provided for the flow area of the flow path.

The ridge retention hub may further include at least one electrode disposed on the first portion.

The at least one electrode may comprise a cylindrical electrode.

The at least one electrode may include a cylindrical shape truncated at both ends.

The plurality of brackets may be circumferentially spaced apart to define a plurality of gaps along the third portion of the cylindrical member. The plurality of brackets may be configured to receive and retain one or more wires.

The second portion of the cylindrical member may include a second diameter that transitions around the curved section in the longitudinal direction from the first diameter to a third diameter.

The curved section may include a concave section proximate the first portion and a convex section proximate the third portion.

Each of the brackets may comprise a curved bracket.

Each bracket may overlap a proximal end of a respective relief groove.

Each bracket may be raised above the outer surface of the ridge-retaining hub.

Each bracket may comprise a first cutout extending in the longitudinal and radial directions of the ridge retaining hub.

Each bracket may comprise a second cutout extending in the longitudinal and radial directions of the ridge holding hub and dividing each bracket into two sections.

The third portion of the cylindrical member may include a plurality of elongated lumens configured to receive one or more wires.

The second portion of the cylindrical member may include a radially extending ring and may have a plurality of third cutouts configured to receive one or more wires.

The plurality of third cuts may be generally aligned with the plurality of elongated cavities in the longitudinal direction.

According to an embodiment of the present invention, a medical probe is provided. The medical probe may include a ridge retention hub including a cylindrical member. The cylindrical member may include a first portion having a first diameter at a distal end of the spine retention hub; a second portion proximate the first portion and having a curved section with a first radius of curvature in the longitudinal direction, wherein the first radius of curvature is approximately half the first diameter. The cylindrical member may also include a third portion proximate the second portion at the proximal end of the ridge retention hub and having a third diameter approximately three times the first diameter. The third portion of the cylindrical member may include a plurality of relief grooves and a plurality of brackets. Each bracket may be disposed at the proximal end of the ridge retention hub and overlap a portion of a corresponding relief groove of the plurality of relief grooves. Additionally, each bracket may be configured with a respective relief groove to receive and retain a respective ridge section. The cylindrical member may further comprise a plurality of first irrigation openings, each first irrigation opening being proximate the distal end of the ridge retention hub. The medical probe may also include a flexible insertion tube, which may have a proximal end and a distal end. The flexible insertion tube may extend along a longitudinal axis. The medical probe may also include an expandable basket assembly proximate the distal end of the flexible insertion tube. The expandable basket assembly may include a single unitary structure that may include a plurality of spine segments. The spine sections may converge at a central spine intersection, which may have one or more cuts that may be configured to allow the spine sections to bend. Each ridge section may have a respective end connected to the distal end of the flexible insertion tube with a respective bracket and a respective relief groove. The central spine intersection may be positioned on a longitudinal axis at a distal end of the expandable basket assembly. The medical probe may include one or more electrodes coupled to each of the ridge sections. Each electrode may define a lumen therethrough such that the ridge section extends through the lumen of each of the one or more electrodes.

The plurality of ridge segments may extend from the central ridge intersection in an equiangular pattern such that the respective angles between respectively adjacent ridge segments are about equal.

The expandable basket assembly may include four to ten of the plurality of spine sections.

The expandable basket assembly may include six of the plurality of spine sections.

The expandable basket assembly may be approximately spherical.

The expandable basket assembly may be approximately oblate spheroid-shaped.

Each lumen may be disposed offset relative to the longitudinal axis of each electrode.

The expandable basket assembly may include at least one discrete cutout located proximate the intersection of the central spine.

The one or more cuts may include a centrally symmetric pattern.

The one or more cuts may comprise an equiangular pattern.

One or more cuts may extend along at least a portion of each ridge section.

Each electrode may include a wire relief adjacent the lumen to allow one or more wires to extend adjacent the lumen.

The lumens may be symmetrically disposed about the longitudinal axis of the electrode.

One or more electrodes may be configured to deliver an electrical pulse for irreversible electroporation having a peak voltage of at least 900 volts (V).

The medical probe may further include a plurality of wires, each wire electrically connected to a respective electrode of the one or more electrodes.

The plurality of ridge segments may comprise nitinol.

The plurality of ridge segments may comprise metal strands.

The medical probe may also include at least one electrode disposed on the first portion.

The at least one electrode may comprise a cylindrical electrode.

The plurality of brackets may be circumferentially spaced apart, which may define a plurality of gaps along the third portion of the cylindrical member. These gaps may be configured to receive and retain one or more wires.

The first flush opening may be disposed on the second portion.

The second portion of the cylindrical member may have a second diameter that transitions from the first diameter to a third diameter around the curved section.

Each of the brackets may comprise a curved bracket.

Each bracket may overlap a proximal end of a respective relief groove.

Each bracket may be raised above the outer surface of the ridge-retaining hub.

The second portion of the cylindrical member may include a ring extending radially and having a plurality of third cutouts configured to receive one or more wires.

The plurality of third cuts may be aligned with the plurality of elongated cavities in the longitudinal direction.

According to an embodiment of the present invention, a medical probe is provided. The medical probe may include a ridge retention hub including a cylindrical member. The cylindrical member may include a first portion having a first diameter at a distal end of the spine retention hub; a second portion proximate the first portion and having a curved section with a first radius of curvature in the longitudinal direction, wherein the first radius of curvature is approximately half the first diameter. The cylindrical member may also include a third portion proximate the second portion at the proximal end of the ridge retention hub and having a third diameter approximately three times the first diameter. The third portion of the cylindrical member may include a plurality of relief grooves and a plurality of brackets. Each bracket may be disposed at the proximal end of the ridge retention hub and overlap a portion of a corresponding relief groove of the plurality of relief grooves. Additionally, each bracket may be configured with a respective relief groove to receive and retain a respective ridge section. The cylindrical member may further comprise a plurality of first irrigation openings, each first irrigation opening being proximate the distal end of the ridge retention hub. The medical probe may also include a flexible insertion tube, which may have a proximal end and a distal end. The flexible insertion tube may extend along a longitudinal axis. The medical probe may also include an expandable basket assembly proximate the distal end of the flexible insertion tube.

The expandable basket assembly may include a single unitary structure that may include a plurality of spine segments. The spine sections may converge at a central spine intersection, which may have one or more cuts that may be configured to allow the spine sections to bend. Each ridge section may have a respective end connected to the distal end of the flexible insertion tube with a respective bracket and a respective relief groove. The central spine intersection may be positioned on a longitudinal axis at a distal end of the expandable basket assembly. The medical probe may include one or more electrodes coupled to each of the ridge sections. Each electrode may define a lumen therethrough such that the ridge section extends through the lumen of each of the one or more electrodes.

Drawings

FIG. 1 is a schematic illustration of a medical system including a medical probe having a distal end including a basket assembly with electrodes and a spine retention hub according to an embodiment of the present invention;

FIG. 2A is a schematic illustration showing a perspective view of a medical probe in an expanded form according to an embodiment of the invention;

FIG. 2B is a schematic illustration showing a side view of a medical probe in a collapsed form according to an embodiment of the invention;

FIG. 2C is a schematic illustration showing an exploded side view of a medical probe according to an embodiment of the present invention;

FIG. 3 is a schematic illustration showing a cross-sectional profile of a basket assembly and a ridge retaining hub of a given medical device according to an embodiment of the present invention; and is also provided with

Fig. 4A, 4B, 4C, 4D, 4E and 4F are schematic illustrations showing providing a profile of a ridge-retaining hub according to an embodiment of the present invention.

Detailed Description

The following detailed description should be read with reference to the drawings, in which like elements in different drawings are numbered identically. The drawings, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the invention. The detailed description illustrates by way of example, and not by way of limitation, the principles of the invention. This description will clearly enable one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what is presently believed to be the best mode of carrying out the invention.

As used herein, the term "about" or "approximately" for any numerical value or range indicates a suitable dimensional tolerance that allows a collection of parts or components to achieve the intended purpose thereof as described herein. More specifically, "about" or "approximately" may refer to a range of values of ±10% of the recited values, for example "about 90%" may refer to a range of values from 81% to 99%.

As used herein, the terms "patient," "subject," "user," and "subject" refer to any human or animal subject, and are not intended to limit the system or method to human use, but use of the subject invention in a human patient represents a preferred embodiment. Furthermore, the vasculature of a "patient," "subject," "user," and "subject" may be that of a human or any animal. It should be understood that the animal may be of any suitable type including, but not limited to, a mammal, a veterinary animal, a livestock animal or a companion animal, and the like. For example, the animal may be a laboratory animal (e.g., rat, dog, pig, monkey, etc.) specifically selected to have certain characteristics similar to humans. It should be appreciated that the subject may be, for example, any suitable human patient. Likewise, the term "proximal" refers to a location closer to an operator or physician, while "distal" refers to a location further from the operator or physician.

As discussed herein, an "operator" may include a doctor, surgeon, technician, scientist, or any other individual or delivery meter device associated with delivering a multi-electrode catheter for treating drug refractory atrial fibrillation to a subject.

As discussed herein, the term "ablation" when referring to the devices and corresponding systems of the present disclosure refers to components and structural features configured to reduce or prevent the generation of unstable cardiac signals in cells by utilizing non-thermal energy, such as irreversible electroporation (IRE), interchangeably referred to in the present disclosure as Pulsed Electric Field (PEF) and Pulsed Field Ablation (PFA). "ablation" as used throughout the present disclosure, when referring to the devices and corresponding systems of the present disclosure, refers to non-thermal ablation of cardiac tissue for certain conditions, including, but not limited to, arrhythmia, atrial flutter ablation, pulmonary vein isolation, supraventricular tachycardia ablation, and ventricular tachycardia ablation. The term "ablation" also includes known methods, devices and systems that implement various forms of body tissue ablation as understood by those skilled in the relevant art.

As discussed herein, the terms "bipolar" and "monopolar" when used in reference to an ablation scheme describe an ablation scheme that differs in terms of current path and electric field distribution. "bipolar" refers to an ablation protocol that utilizes a current path between two electrodes, both of which are positioned at a treatment site; the current density and the current flux density at each of the two electrodes are typically approximately equal. "monopolar" refers to an ablation procedure utilizing a current path between two electrodes, where one electrode having a high current density and a high electrical flux density is positioned at the treatment site and a second electrode having a relatively lower current density and a lower electrical flux density is positioned away from the treatment site.

As discussed herein, the terms "biphasic pulse" and "monophasic pulse" refer to the corresponding electrical signals. A "biphasic pulse" refers to an electrical signal having a positive voltage phase pulse (referred to herein as the "positive phase") and a negative voltage phase pulse (referred to herein as the "negative phase"). "monophasic pulse" refers to an electrical signal having only a positive phase or only a negative phase. Preferably, the system providing biphasic pulses is configured to prevent the application of a direct current voltage (DC) to the patient. For example, the average voltage of the biphasic pulse may be zero volts relative to ground or other common reference voltage. Additionally or alternatively, the system may include a capacitor or other protective component. Voltage amplitudes of biphasic and/or monophasic pulses are described herein, it being understood that the expressed voltage amplitudes are absolute values of the approximate peak amplitudes of each of the positive voltage phase and/or the negative voltage phase. Each phase of the biphasic pulse and the monophasic pulse preferably has a square shape with a substantially constant voltage amplitude during a substantial portion of the phase duration. The phases of the biphasic pulse are separated in time by an inter-phase delay. The inter-phase delay duration is preferably less than or approximately equal to the duration of the phase of the biphasic pulse. The inter-phase delay duration is more preferably about 25% of the duration of the phase of the biphasic pulse.

As discussed herein, the terms "tubular" and "tube" are to be understood in a broad sense and are not limited to structures that are right circular cylinders or that are entirely circumferential in cross-section or have a uniform cross-section throughout their length. For example, the tubular structure is generally shown as a substantially right circular cylinder structure. However, the tubular structure may have a tapered or curved outer surface without departing from the scope of the present disclosure.

As used herein, the term "temperature rating" is defined as the maximum continuous temperature that a component can withstand during its lifetime without causing thermal damage such as melting or thermal degradation (e.g., charring and chipping) of the component.

The present disclosure relates to systems, methods, or uses and devices utilizing an end effector having electrodes attached to ridges. The exemplary systems, methods, and devices of the present invention may be particularly useful for IRE ablation of cardiac tissue to treat cardiac arrhythmias. Ablation energy is typically provided to the heart tissue by an end portion of the catheter that can deliver ablation energy along the tissue to be ablated. Some example catheters include a three-dimensional structure at the tip portion and are configured to apply ablation energy from various electrodes positioned on the three-dimensional structure. Fluoroscopy may be used to visualize the ablation procedure in combination with such exemplary catheters.

Cardiac tissue ablation using thermal techniques such as Radio Frequency (RF) energy and cryoablation to correct for a malfunctioning heart is a well-known procedure. Typically, for successful ablation using thermal techniques, the cardiac electrode potentials need to be measured at various locations in the myocardium. Furthermore, temperature measurements during ablation provide data that enables ablation efficacy. Typically, for ablation protocols using thermal ablation, electrode potential and temperature are measured before, during, and after the actual ablation.

RF methods may have risks that may lead to charring of tissue, burns, steam bursts, phrenic nerve paralysis, pulmonary vein stenosis, and esophageal fistulae. Cryoablation is an alternative to RF ablation, which may reduce some of the thermal risks associated with RF ablation. However, manipulating a cryoablation device and selectively applying cryoablation is generally more challenging than RF ablation; thus, cryoablation is not feasible in certain anatomical geometries that may be reached by an electrical ablation device.

IRE as discussed in this disclosure is a non-thermal cell death technique that may be used for atrial arrhythmia ablation. To ablate using IRE/PEF, biphasic voltage pulses are applied to disrupt the cellular structure of the myocardium. The biphasic pulse is non-sinusoidal and can be tuned to target cells based on the electrophysiology of the cells. In contrast, to ablate using RF, a sinusoidal voltage waveform is applied to generate heat at the treatment region, heating all cells indiscriminately in the treatment region. Thus, IRE has the ability to avoid adjacent heat sensitive structures or tissue, which would be beneficial in reducing the possible complications known to be affected by ablation or separation modalities. In addition or alternatively, monophasic pulses may be used.

Electroporation can be induced by applying a pulsed electric field across the biological cells to cause reversible (temporary) or irreversible (permanent) creation of pores in the cell membrane. Upon application of a pulsed electric field, the cell has a transmembrane electrostatic potential that rises above the static potential. Electroporation is reversible when the transmembrane electrostatic potential remains below the threshold potential, meaning that the pores can close when the applied pulsed electric field is removed and the cells can repair and survive themselves. If the transmembrane electrostatic potential rises above the threshold potential, electroporation is irreversible and the cell becomes permanently permeable. Thus, cells die due to a loss of homeostasis and usually die by apoptosis. Typically, different types of cells have different threshold potentials. For example, cardiac cells have a threshold potential of about 500V/cm, whereas for bone, the threshold potential is 3000V/cm. These differences in threshold potential allow IRE to selectively target tissue based on the threshold potential.

The solutions of the present disclosure include systems and methods for applying electrical signals from catheter electrodes positioned near myocardial tissue, preferably by applying a pulsed electric field effective to induce electroporation in myocardial tissue. The systems and methods can effectively ablate targeted tissue by inducing irreversible electroporation. In some examples, the systems and methods are effective to induce reversible electroporation as part of a diagnostic procedure. Reversible electroporation occurs when the electricity applied with the electrodes is below the electric field threshold of the target tissue that allows cell repair. Reversible electroporation does not kill cells, but allows the physician to view the effect of reversible electroporation on the electrical activation signal near the target site. Exemplary systems and methods for reversible electroporation are disclosed in U.S. patent publication 2021/0162210, the entire contents of which are incorporated herein by reference and attached to the appendix of the parent application 63/336,127.

The pulsed electric field and its effectiveness in inducing reversible and/or irreversible electroporation may be affected by the physical parameters of the system and the biphasic pulse parameters of the electrical signal. Physical parameters may include electrode contact area, electrode spacing, electrode geometry, and the like. Examples presented herein generally include physical parameters suitable for effectively inducing reversible and/or irreversible electroporation. Biphasic pulse parameters of an electrical signal may include voltage amplitude, pulse duration, pulse-to-pulse delay, inter-pulse delay, total applied time, delivered energy, and the like. In some examples, parameters of the electrical signal may be adjusted to induce both reversible and irreversible electroporation given the same physical parameters. Examples of various ablation systems and methods including IRE are provided in U.S. patent publications 2021/0169550A1, 2021/0169567A1, 2021/0169568A1, 2021/0161592A1, 2021/0196372A1, 2021/0177503A1 and 2021/0186604A1, the entire contents of each of these patent publications being incorporated herein by reference and attached in the appendix of the parent application 63/336,127.

To deliver Pulsed Field Ablation (PFA) in an IRE (irreversible electroporation) procedure, the surface area of the electrode in contact with the tissue being ablated should be sufficiently large. As described below, the medical probe includes a tubular shaft having a proximal end and a distal end, and a basket assembly located at the distal end of the tubular shaft. The basket assembly includes a single unitary structure. The unitary structure may include a plurality of linear ridges formed from a sheet of flat material and one or more electrodes coupled to each of the ridges. The plurality of linear ridges may converge at a central ridge intersection having one or more cuts. The cutouts may allow each of the ridges to flex such that the ridges form an approximately spherical or spheroid basket assembly.

Additionally, the ridge-retaining hub may be configured to receive and retain a plurality of ridges and include a plurality of irrigation openings configured to align irrigation fluid (e.g., saline solution) to one or more electrodes found on a basket assembly of a medical probe and/or an ablation site of a patient in an efficient manner to rapidly dissipate heat from the electrodes and/or ablation site during an ablation procedure, thereby minimizing injury to the patient.

Fig. 1 is a schematic illustration of a medical system 20 including a medical probe 22 and a console 24 according to an embodiment of the present invention. Medical system 20 may be based on, for example, a system produced by Biosense Webster inc (31Technology Drive,Suite 200,Irvine,CA 92618USA)The system. In the embodiments described below, the medical probe 22 may be used for diagnostic or therapeutic treatment, such as for performing an ablation procedure in the heart 26 of the patient 28. Alternatively, the medical probe 22 may be used for other therapeutic and/or diagnostic purposes in the heart or other body organs, mutatis mutandis.

The medical probe 22 includes a flexible insertion tube 30 and a handle 32 coupled to the proximal end of the tubular shaft. During a medical procedure, a medical professional 34 may insert the probe 22 through the vascular system of the patient 28 such that the distal end 36 of the medical probe enters a body cavity, such as a chamber of the heart 26. Upon entry of distal end 36 into the chamber of heart 26, medical professional 34 may deploy basket assembly 38 adjacent distal end 36 of medical probe 22. The basket assembly 38 may include a plurality of electrodes 40 attached to a plurality of ridges 214, as described below with reference to fig. 2A and 2B. To begin performing a medical procedure, such as irreversible electroporation (IRE) ablation, the medical professional 34 can manipulate the handle 32 to position the distal end 36 such that the electrode 40 engages the cardiac tissue at the desired location or locations. Upon positioning distal end 36 such that electrode 40 engages heart tissue, medical professional 34 can activate medical probe 22 such that electrode 40 delivers an electrical pulse to perform IRE ablation.

The medical probe 22 may include an introducer sheath including the flexible insertion tube 30 and the handle 32 and a treatment catheter including the basket assembly 38, the electrode 40, and the tubular shaft 84 (see fig. 2A, 2B, and 2C). The treatment catheter is translated through the introducer sheath such that basket assembly 38 is positioned within heart 26. The distal end 36 of the medical probe 22 corresponds to the distal end of the introducer sheath when the basket assembly 38 is received within the flexible insertion tube 30, and the distal end 36 of the medical probe 22 corresponds to the distal end of the basket assembly 38 when the basket assembly 38 extends from the distal end of the introducer sheath. Alternatively, the medical probe 22 may be configured to include a second handle on the treatment catheter and other features as would be understood by one of ordinary skill in the relevant art.

In the configuration shown in fig. 1, the console 24 is connected by a cable 42 to a body surface electrode that typically includes an adhesive skin patch 44 attached to the patient 28. The console 24 includes a processor 46 that, in conjunction with a tracking module 48, determines the position coordinates of the distal end 36 within the heart 26. The position coordinates may be determined based on electromagnetic position sensor output signals provided from the distal portion of the catheter when the generated magnetic field is present. Additionally or alternatively, the location coordinates may be based on impedance and/or current measured between the adhesive skin patch 44 and the electrode 40 attached to the basket assembly 38. In addition to functioning as a position sensor during a medical procedure, the electrode 40 may perform other tasks, such as ablating tissue in the heart.

As described above, the processor 46 may be coupled with the tracking module 48 to determine the location coordinates of the distal end 36 within the heart 26 based on the impedance and/or current measured between the adhesive skin patch 44 and the electrode 40. Such determination is typically after a calibration procedure has been performed that correlates the impedance or current with the known position of the distal end. While the embodiments presented herein describe electrodes 40 that are preferably configured to deliver IRE ablation energy to tissue in heart 26, it is considered to be within the spirit and scope of the present invention to configure electrodes 40 to deliver any other type of ablation energy to tissue in any body cavity. Furthermore, while described in the context of electrodes 40 configured to deliver IRE ablation energy to tissue in heart 26, those skilled in the art will appreciate that the disclosed techniques may be applicable to electrodes used to map and/or determine various characteristics of an organ or other portion of the body of patient 28.

The processor 46 may include real-time noise reduction circuitry 50, typically configured as a Field Programmable Gate Array (FPGA), and analog-to-digital (a/D) signal conversion integrated circuitry 52. The processor may be programmed to execute one or more algorithms and use the characteristics of circuitry 50 and 52 and the modules to enable the medical professional 34 to perform an IRE ablation procedure.

The console 24 also includes an input/output (I/O) communication interface 54 that enables the console 24 to communicate signals from and/or to the electrode 40 and the adhesive skin patch 44. In the configuration shown in fig. 1, console 24 also includes IRE ablation module 56 and switching module 58.

IRE ablation module 56 is configured to generate IRE pulses having peak power in the range of tens of kilowatts. In some examples, electrode 40 is configured to deliver an electrical pulse having a peak voltage of at least 900 volts (V). Medical system 20 performs IRE ablation by delivering IRE pulses to electrodes 40. Preferably, medical system 20 delivers biphasic pulses between electrodes 40 on the ridges. Additionally or alternatively, medical system 20 delivers monophasic pulses between at least one of electrodes 40 and the skin patch.

To dissipate heat and improve the efficiency of the ablation process, the system 20 supplies irrigation fluid (e.g., saline solution) to the distal end 36 and to the electrode 40 via a channel (not shown) in the tubular shaft 84 (see fig. 2A-2C) and via the irrigation opening 98 of the ridge relief groove 90 (see fig. 2C, 3, and 4A-4D). Additionally or alternatively, irrigation fluid may be supplied through the flexible insertion tube 30 to the irrigation openings 98 of the ridge retention hub 90. The console 24 includes a flushing module 60 to monitor and control flushing parameters such as pressure and temperature of the flushing fluid.

Based on the signals received from the electrode 40 and/or the adhesive skin patch 44, the processor 46 may generate an electroanatomical map 62 showing the position of the distal end 36 within the patient. During a procedure, the processor 46 may present the map 62 to the medical professional 34 on the display 64 and store data representing the electroanatomical map in the memory 66. Memory 66 may include any suitable volatile memory and/or nonvolatile memory, such as random access memory or a hard disk drive.

In some embodiments, medical professional 34 can manipulate map 62 using one or more input devices 68. In alternative embodiments, display 64 may include a touch screen that may be configured to accept input from medical professional 34 in addition to presenting map 62.

Fig. 2A is a schematic illustration showing a perspective view of a medical probe 22 having a basket assembly 38 in an expanded form when unconstrained, such as by being pushed out of an insertion tube lumen 80 at the distal end 36 of the insertion tube 30. The medical probe 22 shown in fig. 2A lacks the introducer sheath shown in fig. 1. Fig. 2B shows the basket assembly in collapsed form within the insertion tube 30 of the introducer sheath. In the expanded form (fig. 2A), the ridges 214 curve radially outward, while in the collapsed form (fig. 2B), the ridges are generally disposed along the longitudinal axis 86 of the insertion tube 30.

As shown in fig. 2A, basket assembly 38 includes a plurality of flexible ridges 214 formed at and connected at the ends of tubular shaft 84. During a medical procedure, the medical professional 34 may deploy the basket assembly 38 by extending the tubular shaft 84 from the insertion tube 30, causing the basket assembly 38 to exit the insertion tube 30 and transition to the expanded form. The ridges 214 may have an oval (e.g., circular) or rectangular (which may appear flat) cross-section and comprise a flexible, resilient material (e.g., a shape memory alloy such as nickel titanium, also known as nitinol) forming struts, as will be described in more detail herein.

As shown in fig. 2A, a plurality of flexible linear ridges 214 converge at a central ridge intersection 211. In some examples, the central spine intersection 211 may include one or more cutouts 212 that allow the spine 214 to flex when the respective attachment end 216 of each spine is connected to the spine retention hub 90, as described in more detail below.

In the embodiments described herein, one or more electrodes 40 positioned on ridges 214 of basket assembly 38 may be configured to deliver ablation energy (RF and/or IRE) to tissue in heart 26. Additionally or alternatively, the electrodes may also be used to determine the position of basket assembly 38 and/or measure physiological characteristics, such as local surface potentials at corresponding locations on tissue in heart 26. The electrodes 40 may be biased such that a greater portion of one or more electrodes 40 face outward from the basket assembly 38 such that one or more electrodes 40 deliver a greater amount of electrical energy outward away from the basket assembly 38 (i.e., toward the heart 26 tissue) than inward.

Examples of materials that are ideally suited for forming electrode 40 include gold, platinum, and palladium (and their corresponding alloys). These materials also have a high thermal conductivity that allows the minimal heat generated on the tissue (i.e., by the ablation energy delivered to the tissue) to be conducted through the electrode to the back of the electrode (i.e., the portion of the electrode on the inside of the ridge) and then to the blood pool in heart 26.

Basket assembly 38 has a distal end 39. The medical probe 22 may include a ridge retention hub 90 extending longitudinally from the distal end of the tubular shaft 84 toward the distal end 39 of the basket assembly 38. As described above, the console 24 includes a flush module 60 that delivers flush fluid to the basket assembly 38 through the tubular shaft 84.

Turning to fig. 2C and 3, the basket assembly 38 includes a single unitary structure that includes a plurality of linear ridges 214 formed from a planar sheet of material 210 or tubular material. A ridge retaining hub 90 (described more in fig. 4A-4D) may be inserted into the tubular shaft 84 and attached to the tubular shaft 84. The ridge retention hub 90 may include a cylindrical member 94 including a plurality of relief grooves 96, a plurality of flushing openings 98, and at least one ridge retention hub electrode 99, or some combination thereof. The ridge retaining hub electrode 99 may comprise a cylindrical shape (see, e.g., fig. 4A, 4E, and 4F) that may or may not be truncated at two opposite ends (see, e.g., fig. 4B, 4C, and 4D). Relief grooves 96 may be provided on the outer surface of the cylindrical member 94 and/or the third portion 103 (described below with reference to fig. 4B, 4C, and 4D) and configured to allow a portion of each ridge 214 (such as each ridge attachment end 216) to fit into the respective relief groove 96. The attachment end 216 may be a generally linear end of the spine 214. The attachment end 216 may be configured to extend outwardly from the spine retention hub 90 such that the basket assembly 38 is positioned outwardly from the spine retention hub 90 and, thus, the tubular shaft 84. In this manner, the ridges 214 may be configured to position the basket assembly 38 away from the distal end of the tubular shaft 84 and away from the distal end of the insertion tube 30 when the basket assembly is deployed.

As described above, the console 24 includes an irrigation module 60 that delivers irrigation fluid to the distal end 36. The plurality of irrigation openings 98 may be angled to spray or otherwise disperse irrigation fluid to tissue in a given electrode 40 or heart 26. Since the electrode 40 does not include irrigation openings that deliver irrigation fluid, the configuration described above enables heat transfer from the tissue to the portion of the electrode on the inside of the ridge 214 (i.e., during an ablation procedure), and the electrode 40 may be cooled by aligning the irrigation fluid with the portion of the electrode 40 on the inside of the ridge 214 via the irrigation openings 98. The spine retention hub electrode 99 disposed at the distal end of the retention hub 90 may be used in combination with the electrode 40 on the spine 214 or, alternatively, may be used independently of the electrode 40 for reference mapping or ablation.

Fig. 4A, 4B, 4C, 4D, 4E, and 4F illustrate various ridge-retaining hubs 90 according to embodiments of the invention. Fig. 4A shows a ridge retaining hub 90 that may include a cylindrical member 94. The cylindrical member 94 can include a first portion 101 having a first diameter 108 at the distal end 104a of the ridge retention hub 90.

The cylindrical member 94 may also have a second portion 102 adjacent the first portion 101 having a curved section with a first radius of curvature 110 in the longitudinal direction. The first radius of curvature 110 may be approximately half of the first diameter 108. The second portion 102 may also have a second diameter that transitions in the longitudinal direction from the first diameter 108 to the third diameter 112 of the third portion 103 around the curved section of the second portion 102. The curved section of the second portion 102 may include a concave section proximate the first portion 101 and a convex section proximate the third portion 103. The second portion 102 may include a ring extending radially and having a plurality of third cutouts 106c configured to receive one or more wires (not shown). The plurality of third cutouts 106c may be aligned with the plurality of elongated cavities 105 in the longitudinal direction. In some embodiments (see, e.g., fig. 4F), the ridge-retaining hub may include an elongated cavity 105 extending from the proximal end 104b to the distal end 104a through the first, second, and third portions 101, 102, 103 of the ridge-retaining hub 90.

The cylindrical member 94 can also include a third portion 103 adjacent the second portion 102 at the proximal end 104b of the ridge retaining hub 90. The third portion 103 may have a third diameter 112 that is approximately three times the first diameter 108. The third portion 103 may include a plurality of relief grooves 96, a plurality of elongated cavities 105 configured to receive one or more wires, and a plurality of brackets 95. Each bracket 95 may be disposed at the proximal end 104b of the ridge retaining hub 90, and each bracket 95 may overlap a portion of a respective relief groove 96 of the plurality of relief grooves 96. In some embodiments (see, e.g., fig. 4E and 4F), each of the plurality of relief grooves 06 may include a stepped wall connecting an upper surface of the third portion 103 with a hole bottom of the relief groove 96.

Each bracket 95 may be configured with a respective relief groove 96 to receive and retain a respective ridge section 214 and may be curved in a circumferential direction about the third portion 103. Each bracket 95 may overlap the proximal end of the respective relief groove 96 and its relief groove opening 114. The plurality of brackets 95 may be circumferentially spaced apart to define a plurality of gaps 97 (see fig. 4A) along a third portion of the cylindrical member 94, the plurality of gaps configured to receive and retain one or more wires (not shown). Each bracket 95 may be raised above the outer surface of the ridge retaining hub 90 (see, e.g., fig. 4A-4E). In some cases, each bracket 95 may include a first cutout 106a (see, e.g., fig. 4B-4E) extending in the longitudinal and radial directions of the ridge-retaining hub 90 and/or a second cutout (see, e.g., fig. 4C-4E) extending in the longitudinal and radial directions and dividing each bracket 95 into two sections.

The cylindrical member 94 can also include a plurality of flushing openings 98. Each irrigation opening may be proximate to the distal end 104a of the ridge retention hub 90. Further, the cylindrical member 94 may include a plurality of relief groove openings 114, each of which may be proximate the proximal end 104b of the ridge retaining hub 90. The plurality of flushing openings 98 may include six openings 98 aligned with the plurality of relief grooves 96. Each opening 98 may comprise about 0.05mm ² To 0.6mm ² (e.g., about 0.24 mm) ² ) Is provided for the flow area of the flow path. As described above, the plurality of irrigation openings 98 are configured to align an irrigation fluid (e.g., saline solution) to one or more electrodes 40 found on the basket assembly 38. The at least one irrigation opening 98 may also be configured to align (or selectively align) irrigation fluid to an ablation site of the patient. In some embodiments, (e.g., fig. 4E), the flush opening is adjacent to a recess 121 configured to further assist in aligning the flush fluid.

The above embodiments are cited by way of example, and the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and sub-combinations of the various features described hereinabove as well as variations and modifications thereof which would occur to persons skilled in the art upon reading the foregoing description and which are not disclosed in the prior art.

Claims

1. A spine retention hub for a basketball-type catheter comprising:

a cylindrical member, the cylindrical member comprising:

a first portion at a distal end of the ridge retention hub and having a first diameter; a second portion proximate the first portion and having a curved section with a first radius of curvature in a longitudinal direction, the first radius of curvature being about half the first diameter; and

a third portion proximate the second portion at a proximal end of the ridge-retaining hub and having a third diameter approximately three times the first diameter, the third portion comprising:

a plurality of relief grooves;

a plurality of brackets, each bracket disposed at the proximal end of the ridge-retaining hub, each bracket overlapping a portion of a respective one of the plurality of relief grooves, each bracket, together with the respective relief groove, configured to receive and retain a respective ridge section; and

a plurality of first irrigation openings, each first irrigation opening being proximate the distal end of the ridge-retaining hub.

2. The ridge-retaining hub of claim 1, wherein the plurality of first flushing openings comprises six openings aligned with the plurality of relief grooves.

3. The spine retention hub of claim 1 wherein each opening of the plurality of first openings comprises about 0.05mm ² To about 0.6mm ² Is provided for the flow area of the flow path.

4. The spine retention hub of claim 1 further comprising at least one electrode disposed on the first portion.

5. The spine retention hub of claim 4 wherein the at least one electrode comprises a cylindrical electrode.

6. The ridge-retaining hub of claim 4 wherein the at least one electrode comprises a cylindrical shape that is truncated at both ends.

7. The spine retention hub of claim 1 wherein the plurality of brackets are circumferentially spaced apart to define a plurality of gaps along the third portion of the cylindrical member, the plurality of gaps configured to receive and retain one or more wires.

8. The ridge-retaining hub of claim 1 wherein the second portion of the cylindrical member has a second diameter that transitions in a longitudinal direction around the curved section from the first diameter to the third diameter.

9. The ridge-retaining hub of claim 8, wherein the curved section includes a concave section proximate the first portion and a convex section proximate the third portion.

10. The ridge-retaining hub of claim 9, wherein each bracket comprises a curved bracket and overlaps a proximal end of a respective relief groove.

11. The spine retention hub of claim 10 wherein each brace is raised above an outer surface of the spine retention hub.

12. The spine retention hub of claim 11 wherein each bracket comprises a first cutout extending in the longitudinal and radial directions of the spine retention hub.

13. The spine retention hub of claim 12 wherein each scaffold comprises a second cutout extending in the longitudinal and radial directions of the spine retention hub and dividing each scaffold into two sections.

14. The spine retaining hub of claim 13, wherein:

the third portion of the cylindrical member includes a plurality of elongated cavities configured to receive one or more wires, and

the second portion of the cylindrical member includes a ring extending radially and having a plurality of third cutouts configured to receive the one or more wires.

15. The spine retention hub of claim 14 wherein the third plurality of cutouts are generally aligned with the plurality of elongated cavities in the longitudinal direction.

16. A medical probe, comprising:

a spine retention hub, the spine retention hub comprising:

a cylindrical member, the cylindrical member comprising:

a plurality of relief grooves;

A plurality of first irrigation openings, each first irrigation opening being proximate the distal end of the ridge-retaining hub;

a flexible insertion tube having a proximal end and a distal end, the flexible insertion tube extending along a longitudinal axis;

an expandable basket assembly proximate the distal end of the flexible insertion tube, the expandable basket assembly comprising:

a single unitary structure comprising the plurality of spine sections converging at a central spine intersection having one or more cutouts configured to allow the spine sections to bend, each spine section having a respective end connected to the distal end of the flexible insertion tube with a respective bracket and the respective relief groove, the central spine intersection being positioned on the longitudinal axis at the distal end of the expandable basket assembly; and

one or more electrodes coupled to each of the ridge segments, each electrode defining a lumen therethrough such that a ridge segment extends through the lumen of each of the one or more electrodes.

17. The medical probe of claim 16, wherein each of the plurality of first irrigation openings comprises about 0.05mm ² To about 0.6mm ² Is provided for the flow area of the flow path.

18. The medical probe of claim 16, wherein the plurality of ridge segments extend from the central ridge intersection in an equiangular pattern such that the respective angles between respectively adjacent ridge segments are about equal.

19. A medical probe, comprising:

a spine retention hub, the spine retention hub comprising:

a cylindrical member, the cylindrical member comprising:

a first portion at a distal end of the ridge retention hub and having a first diameter;

a second portion adjacent to the first portion and having a curved section in a longitudinal direction; and

a third portion proximate the second portion at a proximal end of the ridge-retaining hub and having a third diameter different from the first diameter, the third portion comprising:

a plurality of relief grooves;

a plurality of brackets, each bracket disposed at the proximal end of the ridge-retaining hub, each bracket overlapping a portion of a respective one of the plurality of relief grooves, each bracket, together with the respective relief groove, configured to receive and retain a respective ridge section of a plurality of ridge sections;

A plurality of first irrigation openings, each first irrigation opening disposed proximate the distal end of the ridge retention hub;

a flexible insertion tube having a proximal end and a distal end, the flexible insertion tube extending along a longitudinal axis; and

an expandable basket assembly proximate the distal end of the flexible insertion tube.

20. The medical probe of claim 19, wherein the expandable basket assembly comprises:

a single unitary structure comprising the plurality of spine sections converging at a central spine intersection having one or more cutouts allowing the spine sections to bend, each spine section having a respective end connected to the distal end of the flexible insertion tube with a respective bending bracket and the respective relief groove, the central spine intersection being positioned on the longitudinal axis at the distal end of the expandable basket assembly; and