CN116965906A

CN116965906A - Basket catheter with clover structure to provide predetermined lateral stiffness and axial strain

Info

Publication number: CN116965906A
Application number: CN202310477352.5A
Authority: CN
Inventors: J·T·凯斯; K·J·埃雷拉; C·T·比克勒; A·帕帕约阿努; J·G·利希特; K·M·奥卡斯基
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
Also published as: CN220655660U

Abstract

The present application proposes a medical probe comprising an expandable basket assembly coupled to a distal end of a tubular shaft. The basket assembly includes a clover cutout structure at a distal end thereof and a ridge extending proximally from the clover structure and coupled to the tubular shaft. The clover structure includes a sinusoidal member extending from one ridge to an adjacent ridge in a direction about the longitudinal axis. The sinusoidal member may be sized to provide a lateral stiffness of the expandable basket assembly within a predetermined range and a maximum peak stress during retraction of the expandable basket assembly into the intermediate conduit such that the maximum peak stress is less than a predetermined threshold.

Description

Basket catheter with clover structure to provide predetermined lateral stiffness and axial strain

Cross Reference to Related Applications

The present application claims the priority of prior filed U.S. provisional patent application No. 63/336,023 filed on 4 months 28 of 2022 (attorney docket No. 253757.000242BIO6675USPSP1), U.S. provisional patent application No. 63/336,094 filed on 4 months 28 of 2022 (attorney docket No. 253757.000137BIO6693USPSP1), U.S. provisional patent application No. 63/477,404 filed on 12 months 28 of 2022 (attorney docket No. 253757.000261BIO6744USPSP1), and U.S. provisional patent application No. 63/477,819 filed on 12 months 29 of 2022 (attorney docket No. 237575.000331BIO6794USPSP1), each of which is incorporated by reference in its entirety as if fully set forth herein.

Technical Field

The present invention relates generally to medical devices, and in particular to catheters having substantially oval or trapezoidal electrodes, 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 some rare drawbacks due to the skill of the operator, 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 may reduce some of the thermal risks associated with RF ablation, but may cause tissue damage due to the very low temperature nature of such devices. 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 publications 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 priority provisional patent application U.S. Pat. No. 63/477,404.

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. Accordingly, what is needed are devices and methods of forming improved basket assemblies that generally can help reduce the time required to manufacture basket assemblies, alternative catheter geometries, and alternative electrode shapes and sizes.

Disclosure of Invention

The present invention proposes a medical probe comprising an expandable basket assembly coupled to a distal end of a tubular shaft. The basket assembly includes a clover cutout structure at a distal end thereof and a ridge extending proximally from the clover structure and coupled to the tubular shaft. The clover structure includes a sinusoidal member extending from one ridge to an adjacent ridge in a direction about the longitudinal axis. The sinusoidal member may be sized to provide a lateral stiffness of the expandable basket assembly within a predetermined range and a maximum peak stress during retraction of the expandable basket assembly into the intermediate conduit such that the maximum peak stress is less than a predetermined threshold.

An exemplary medical probe may include a tubular shaft and an expandable basket assembly. The tubular shaft may have a proximal end and a distal end and may extend along a longitudinal axis of the medical probe. An expandable basket assembly may be coupled to the distal end of the tubular shaft. The basket assembly may include a plurality of ridges extending along the longitudinal axis from a proximal central proximal ridge portion to a distal ridge portion. The distal spine portion may define a clover structure. The clover structure may be radially disposed about the longitudinal axis. The clover structure may define a central cutout having a central area disposed about the longitudinal axis. The clover structure may comprise a sinusoidal member extending from one ridge to an adjacent ridge in a direction about the longitudinal axis. The sinusoidal member may meander around the first virtual circle, the second virtual circle, and the third virtual circle. The first virtual circle has a first radius. The first virtual circle may have its center positioned at a first distance from the longitudinal axis. The second virtual circle has a second radius. The second virtual circle positions its center at a second distance from the longitudinal axis that is less than the first distance. The third virtual circle has a third radius approximately equal to the first radius. The third virtual circle has its center positioned at a third distance from the longitudinal axis that is approximately equal to the first distance. The clover structure may define a height measured from a point on the perimeter of the second virtual circle to a neck directly distant from the longitudinal axis relative to the second virtual circle and located between adjacent first and second virtual circles. The first radius, the second radius, the third radius, and the height may be configured to provide a lateral stiffness of the expandable basket assembly within a predetermined range.

The first radius, the second radius, the third radius, and the height are configured to provide a maximum peak stress during retraction of the expandable basket assembly into the intermediate conduit such that the maximum peak stress is less than a predetermined threshold.

The first radius may be measured as about 33% of the height. The second radius may be measured as about 39% of the height. The third radius may be measured as about 33% of the height. The minimum width of the sinusoidal member may be measured as about 25% of the height.

The first radius may be measured as between 31% and 35% of the height. The second radius may be measured as between 37% and 41% of the height. The third radius may be measured as between 31% and 35% of the height. The minimum width of the sinusoidal member may be measured as between 23% and 27% of the height.

The central area may have an area of about 0.8 square millimeters. The fourth virtual circle surrounding the sinusoidal member may have an area of about 14 times the central area. Each of the first virtual circle and the third virtual circle may be positioned at a first distance from the central axis, while the second virtual circle is positioned at a second distance that is approximately 1/2 of the first distance.

The sinusoidal member may be tangential to the central circle.

The expandable basket assembly may include a coating covering the sinusoidal member and a central cutout surrounded by the sinusoidal member.

The expandable basket assembly may include a coating covering a majority of the sinusoidal member and include an opening at the longitudinal axis.

The cross-sectional shape of each electrode may have a substantially oval or trapezoidal shape.

Each of the ridges may include at least one retaining member extending generally transverse to the ridge.

The medical probe may also include a plurality of electrodes. Each of the plurality of electrodes may include a body defining a hollow portion extending through the body of the electrode such that the ridge is insertable into the hollow portion and retained by the at least one retaining member.

The at least one retaining member may comprise an arcuate member. The at least one retaining member may comprise two arcuate members disposed in opposite directions and transverse to the longer length of each ridge.

The at least one retaining member may include a first set of retaining members and a second set of retaining members spaced apart along the spine. The first set may include two arcuate members disposed in opposite directions and transverse to the longer length of each ridge. The second set may include two arcuate members disposed in opposite directions and transverse to the longer length of each ridge such that each electrode is captured between the first and second sets of retaining members.

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

The medical probe further includes a plurality of electrically insulating sheaths each disposed between a respective one of the plurality of ridges and a respective electrode, thereby electrically isolating the respective electrode from the respective ridge.

The sinusoidal member may include an inner arc surrounding the second virtual circle such that the inner arc is positioned entirely less than the second distance from the longitudinal axis. The sinusoidal member may have an outer portion surrounding the first virtual circle and surrounding the second virtual circle such that the outer portion is positioned entirely greater than the second distance from the longitudinal axis. A majority of the outer portion of the sinusoidal member may be covered by a respective one of the electrically insulating jackets.

At least a portion of the inner arc of the sinusoidal member may be exposed to the environment.

The distal portion of each of the plurality of electrically insulative sheaths may taper outwardly and inwardly following the curvature of the outer portion of the sinusoidal member. The distal portion of each of the plurality of electrically insulating sheaths may abut the distal portion of an adjacent insulating sheath.

The medical probe may further include two electrodes for each of the plurality of ridges, the two electrodes coupled to the respective ridges.

The medical probe may further include a wire disposed within a respective sheath of the plurality of electrically insulating sheaths, wherein the wire is electrically connected to the respective electrode.

The plurality of ridges may comprise a material selected from the group consisting of nitinol, cobalt chromium, stainless steel, titanium, and combinations thereof.

Each electrode may comprise a material selected from the group consisting of stainless steel, cobalt chromium, gold, platinum, palladium, and alloys or combinations thereof.

The medical probe may also include a plurality of electrodes configured to deliver an electrical pulse for irreversible electroporation, the pulse including a peak voltage of at least 900 volts (V).

The plurality of ridges may be configured to form an approximately spherical basket assembly when in the expanded form.

The plurality of ridges may be configured to form an approximately oblate spheroid basket assembly when in the expanded form.

The medical probe may further include an irrigation port disposed in the proximal portion of the basket to deliver irrigation fluid to the plurality of electrodes.

The central cutout may approximate a central circle having a central area, and wherein the clover structure is disposed within a fourth circle having its center on the longitudinal axis such that a portion of the clover proximate the central circle is spaced along the longitudinal axis relative to a portion of the clover proximate the fourth circle, thereby defining a concave clover structure.

The clover structure is concave, with the center of the clover structure extending toward the proximal central spine portion of the basket to approximate a concave surface disposed about the longitudinal axis.

The reference electrode may be disposed near the distal end of the tubular shaft.

The spine retention hub may be coupled to the distal end of the tubular shaft to connect the spine to the retention hub.

A cylindrical protrusion may be provided to position the reference electrode on the protrusion.

The ridge retention hub may include an outlet port to allow fluid delivered to the distal end tubular shaft to exit the outlet port into the volume surrounded by the basket ridge.

An exemplary method may include the following steps performed in various orders and with intervening steps as understood by those of skill in the relevant arts. The method may include cutting a tubular frame including a plurality of ridges extending along a longitudinal axis from a proximal ridge portion to a distal ridge portion, the distal ridge portion defining a clover structure disposed radially about the longitudinal axis, the tubular frame configured to move from a tubular shape to an expansion basket shape. In the expansion basket shape, the plurality of ridges are curved away from the longitudinal axis, the clover structure defines a central cutout having a central area disposed about the axis, and the clover structure includes a sinusoidal member extending from one ridge to an adjacent ridge in a direction about the longitudinal axis. In the expansion basket shape, the sinusoidal member meanders around the first virtual circle, the second virtual circle, and the third virtual circle. The first virtual circle has a first radius and a center positioned a first distance from the longitudinal axis. The second virtual circle has a second radius and a center positioned a second distance from the longitudinal axis. The second distance may be less than the first distance. The third virtual circle has a third radius that may be approximately equal to the first radius. The third virtual circle positions the center thereof at a third distance from the longitudinal axis, which may be approximately equal to the first distance from the longitudinal axis. In the expansion basket shape, the clover structure may also define a height measured from a point on the perimeter of the second virtual circle to a neck that is directly distant from the longitudinal axis relative to the second virtual circle and between adjacent first and second virtual circles. The first radius, the second radius, the third radius, and the height are configured to provide a lateral stiffness of the expandable basket assembly within a predetermined range. The method may further include forming a basket assembly for the medical probe such that the tubular frame provides structural support for the basket assembly and such that the first radius, the second radius, the third radius, and the height are configured to provide lateral stiffness of the expandable basket assembly within a predetermined range.

The method may further include aligning the plurality of ridges with a plurality of electrodes, each electrode having a lumen extending through a body of the electrode. The method may further include inserting each of the plurality of ridges into a lumen of an electrode of the plurality of electrodes. The method may further include retaining the plurality of electrodes on the plurality of ridges. Maintaining the plurality of electrodes on the plurality of ridges may include maintaining an electrode of the plurality of electrodes by at least one biasing member.

The at least one biasing member may include a biasing member disposed outside of the lumen of the electrode. Additionally or alternatively, the at least one biasing member may include a biasing member disposed within a lumen of the electrode.

The method may further include positioning a spine of the expandable basket assembly through a lumen of an electrically insulating sheath of the plurality of electrically insulating sheaths. The method may further include positioning the wire through a lumen of the electrically insulating sheath. The method may further include positioning an electrode of the plurality of electrodes over the electrically insulating sheath. The method may further include electrically connecting the wire to the electrode through an aperture in the electrically insulating sheath.

The method may further include covering a majority of the sinusoidal member with a plurality of electrically insulating sheaths. The distal portion of each of the plurality of electrically insulating sheaths abuts the distal portion of an adjacent insulating sheath.

The method may further include covering a majority of the outer portion of the sinusoidal member with a plurality of electrically insulating sheaths such that the outer portion of the sinusoidal member meanders around the first virtual circle and around the second virtual circle, and such that the outer portion is positioned entirely greater than the second distance from the longitudinal axis. The inner arc of the sinusoidal member may remain exposed to the environment such that the inner arc meanders around the second virtual circle and such that the inner arc is positioned entirely less than the second distance from the longitudinal axis. The distal portion of each of the plurality of electrically insulative sheaths may taper outwardly and inwardly following the curvature of the outer portion of the sinusoidal member.

Each respective ridge of the plurality of ridges may include a first electrode and a second electrode thereon. The method may further include aligning each respective ridge of the plurality of ridges with the first electrode and the second electrode. The method may further include inserting each respective ridge of the plurality of ridges into the lumen of the first electrode and the lumen of the second electrode. The method may further include fitting an end of each respective ridge of the plurality of ridges to a tubular shaft sized to traverse the vasculature.

The method may further include offsetting the electrode along the longitudinal axis between adjacent ridges.

The electrode body lumen is configured to receive a wire of a medical probe.

The wire may be insulated from the ridge.

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 according to an embodiment of the present invention;

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

FIG. 2B is a cross-sectional view orthogonal to the longitudinal axis to show the cross-sectional plane of the electrode and the internal components of the spine assembly;

FIG. 2C is a perspective view of electrodes mounted on an insulating sheath with wires extending along the ridges to connect to each electrode;

FIG. 3A shows the medical probe of FIG. 2A with only the underlying ridge structure and one electrode disposed on the ridge;

FIG. 3B shows a ridge structure formed from a tube blank;

FIG. 4A shows an end planar view of the distal end of the basket ridge structure of FIG. 3A as if the entire basket ridge were captured flat between two flat glass plates for viewing by a viewer positioned on the longitudinal axis;

FIG. 4B shows an end view of the spine structure of FIG. 4A with a design naming clover structure disposed near the distal end of the spine structure of FIG. 3A;

FIG. 5A shows a side view of the basket ridge structure of FIG. 3A to illustrate the concave surface of a clover structure that may be approximated by a virtual sphere;

FIG. 5B is a close-up of the illustration shown in FIG. 5A to show the concavity of the distal central portion of basket assembly 38;

fig. 6A and 6B show close-up views showing electrodes;

FIG. 7A shows a perspective view of a distal end of a medical probe in an expanded form and including a coated distal end according to an embodiment of the invention;

FIG. 7B shows a ridge structure formed from a tube blank and including a coated distal end;

FIG. 7C shows a perspective view of a distal end of a medical probe in an expanded form and including a coated distal end having a central opening, according to an embodiment of the invention;

FIG. 8A shows a perspective view of a medical probe including a closely spaced electrode pair and a sheath extending over a portion of a distal clover structure;

FIG. 8B shows a distal end view of the medical probe shown in FIG. 8A;

FIG. 8C shows a side view of two adjacent ridges of the medical probe shown in FIG. 8A in a collapsed form for delivery;

FIG. 9 shows a perspective view of a medical probe subjected to lateral forces and resulting lateral displacement;

FIG. 10 illustrates selected dimensions of a clover structure tailored to achieve the desired mechanical properties of the spine basket structure;

FIGS. 11A, 11B and 11C illustrate distal end views of the clover configuration of varying dimensions shown in FIG. 10;

FIG. 12 shows an exploded view of a medical probe; and is also provided with

FIGS. 13A and 13B illustrate a contact force sensor assembly and a ridge retention hub of a medical probe;

FIG. 14A is a schematic illustration showing a top perspective view of a flush hub in accordance with the disclosed technology;

FIG. 14B is a schematic illustration showing a bottom perspective view of a flush hub in accordance with the disclosed technology;

FIG. 15A is a schematic illustration showing a side view of a flushing hub in accordance with the disclosed technology;

FIG. 15B is a schematic illustration showing a top view of a flush hub in accordance with the disclosed technology;

FIG. 15C is a schematic illustration showing a bottom view of a flush hub in accordance with the disclosed technology;

FIG. 16 is a schematic illustration showing a cross-sectional view of a flush hub in accordance with the disclosed technology; and is also provided with

FIG. 17 is a schematic illustration showing the flow of fluid through a flushing hub according to an embodiment of the invention;

FIG. 18A is a schematic illustration showing a perspective view of another exemplary medical probe in which an electrode is in an expanded form in accordance with another example of the disclosed technology; and is also provided with

Fig. 18B is a schematic illustration showing a perspective view of the medical probe of fig. 8A showing ridges in accordance with the disclosed technology.

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 from the recited value of ±20%, for example "about 90%" may refer to a range of values from 72% to 108%.

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 this disclosure, when referring to the devices and corresponding systems of this disclosure, refers to non-thermal ablation of cardiac tissue for certain conditions, including, but not limited to, arrhythmia, atrial fibrillation ablation, 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 or more electrodes, both of which are positioned at a treatment site; the current density and the electric flux density at each of the electrodes are typically approximately equal. "monopolar" refers to an ablation procedure utilizing a current path between two or more electrodes, wherein a first electrode or combination of electrodes is subjected to a high current density and a high electrical flux density and positioned at a treatment site, and a second electrode or series of electrodes is subjected to a relatively lower current density and a lower electrical flux density and 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 comprising a positive voltage phase pulse (referred to herein as a "positive phase") and a negative voltage phase pulse (referred to herein as a "negative phase"). "monophasic pulse" refers to an electrical signal that includes only a positive or 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 that includes a substantially constant voltage amplitude during most of the phase's 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 that includes an electrode attached to a spine. 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. Ablation procedures incorporating such exemplary catheters may be visualized using fluoroscopy, ultrasound, and/or 3D mapping systems utilizing magnetic and/or impedance-based navigation.

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 from a loss of homeostasis, typically from programmed cell death or apoptosis, which is believed to leave less scar tissue than other modes of ablation. 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 voltage 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 in the appendix of priority provisional patent application U.S.63/477,404.

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 priority provisional patent application U.S.63/477,404.

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 or tube blank 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 comprising 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. It is noted that the cuts (in the various configurations described and illustrated in this specification) allow the basket to be compressed into a smaller form factor when undeployed (or being retracted into the delivery sheath) without buckling or plastic deformation.

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 in the heart or other body organ, mutatis mutandisOther therapeutic and/or diagnostic purposes.

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 to distal end 39 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 the description of fig. 2A, 2B, 2C, 3A, and 3B. 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 (disposed on extension structure 38) 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). The treatment catheter is advanced 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 tube 30) corresponds to the proximal portion of the basket assembly 38 when the basket assembly 38 extends from the distal end of the introducer sheath (fig. 2A). 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 being used to record ECG signals or as a position sensor during a medical procedure, the electrodes 40 may perform other tasks, such as ablating tissue in the heart.

As described above, in conjunction with the tracking module 48, the processor 46 may determine the position coordinates of the distal end 36 of the tube 30 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 that include peak power in the range of tens of kilowatts. In some examples, electrode 40 is configured to deliver an electrical pulse comprising 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 at least one skin patch.

To prevent blood clotting, the system 20 supplies an irrigation fluid (e.g., a physiological saline solution) to the distal end 36 of the tube 30 and the proximal region of the basket assembly 38. Note that the irrigation fluid may be supplied through the flexible insertion tube 30. The console 24 includes a flushing module 60 to monitor and control flushing parameters such as pressure and temperature of the flushing fluid. It is noted that while the exemplary embodiment of the medical probe is preferably for IRE or PFA, it is also within the scope of the present invention to use the medical probe alone for RF ablation only (monopolar mode or bipolar mode with external ground electrode), or sequentially (some electrodes in IRE mode and other electrodes in RF mode) or simultaneously (electrode set in IRE mode and other electrodes in RF mode) in combination with IRE ablation and RF ablation.

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 an illustration of a perspective view of a medical probe 22 including a basket assembly 38 in an expanded form when unconstrained, such as by being pushed out of an insertion lumen at the distal end 36 of the insertion tube 30. The probe 22 may include a contact force sensor 400 to determine the contact force of the ridges against the heart tissue. Details of the contact force sensor are shown and described in U.S. patent application publication No. US2021/0077180A1 published at month 18 of 2021, which is incorporated herein by reference.

It should be noted that the medical probe 22 shown in fig. 2A lacks the introducer sheath shown in fig. 1. In the expanded form of fig. 2A, the ridges 214 curve radially outward, while in the collapsed form (not shown), the ridges 214 are generally disposed along the longitudinal axis 86 of the insertion tube 30. In fig. 2A, a plurality of electrically insulating sheaths 217 are provided such that each sheath can be disposed between a respective ridge 214 of the plurality of ridges and a respective electrode 40 of the plurality of electrodes, thereby electrically isolating the plurality of electrodes from the plurality of ridges.

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 shape (e.g., circular) or rectangular shape, which may appear as a flat cross-section, and include a flexible, resilient material (e.g., a shape memory alloy such as nickel titanium, also known as nitinol) that forms struts, as will be described in more detail herein. As shown in fig. 2A, 2B and 3A, basket assembly 38 has a proximal portion 36 and 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. 3A, a plurality of flexible linear ridges 214 converge at a central ridge intersection 211, which is also disposed on a longitudinal axis 86 defined by the ridges 214. 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.

As shown herein, electrodes 40 positioned on ridges 114 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, rather 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, which 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.

Referring to fig. 3A, basket assembly 38 of medical probe 22 is shown without insulating sleeve 217 or without wiring associated with electrode 40 disposed within sleeve 217 to illustrate novel underlying basket structure 38. The basket 38 comprises a single unitary structure including a plurality of ridges 214 formed from a cylindrical tube blank (fig. 3B) and treated to cause the ridges 214 to be biased radially outwardly. The material for the ridges 214 may be selected from the group consisting of nitinol, cobalt chromium, stainless steel, titanium, and combinations thereof.

Referring to fig. 2A, a ridge retention hub 90 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 a hub end 99, which allow flushing fluid to flow out into the volume defined by the basket ridge. Relief grooves 96 may be provided on an outer surface of the cylindrical member 94 and configured to allow a portion of each ridge 214, such as each ridge attachment end 216, to fit into a corresponding relief groove 96 of the retention hub 90 (also referred to as a connector contacting the force sensor 400). 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 38 is deployed. The reference electrode 95 may be disposed on the tab 94 or on the hub end surface 99. It should be noted that the hub 90 may actually serve a variety of functions: (1) holding the spine leg proximally; (2) Allowing hub 90 (and basket assembly 22) to be connected to distal tube 84; (3) Acting as a fluid diverter for irrigation fluid delivered through distal tube 84; and (4) providing a reference electrode 95.

Referring to fig. 2B, a cross-sectional view of basket assembly 38 is shown cut away to show ridge 214 disposed within sheath 217, with wire 41 extending along ridge 214 and through sheath 217 to connect with electrode 40 via connection point (e.g., pad) 43.

Fig. 2C shows a perspective view of the opaque sheath 217 from which it can be seen that the wires 41 extend through the sheath 217 to the respective connection points 43 of the electrodes 40. It should be noted that the connection point 43 need not be disposed within the lumen 70 of the electrode 40, but may be external to the lumen 70 so long as the connection point does not interfere with tissue contact of the electrode 40.

Referring to fig. 6A and 6B, in a preferred embodiment, the electrode 40 is about 2mm to about 3mm long, about 1.5mm to about 2.5mm wide, and about 0.8mm to about 1.5mm high. Lumen 70 may have a negative surface area of about 0.4 square millimeters to about 0.7 square millimeters. Lumen 70 is not placed at the geometric center, but is offset lower such that center 86 of lumen 70 is more toward planar bottom surface 76. This arrangement ensures that the top surfaces 78 and 80 of the electrodes 40 are more above the lumen 70 than below the lumen 70.

Referring to fig. 3A, the electrode 40 may be generally positioned in place relative to the spine 214 by a retaining member 220 integrally formed with the spine 214. As shown in fig. 3A, each of the ridges 214 may include at least one retaining member 220 extending generally transverse to the ridge 214. To allow the ridges 214 to be inserted through the lumen 70 (fig. 6A) extending through the electrode 40, each ridge 214 may be bisected by the central ridge member 222 such that an empty space 224 is provided to allow the retaining member 220 to flex inwardly toward the central ridge member 222. The shape of the retaining member 220 may be any shape that serves to allow the member 220 to be compressed for insertion into the lumen 70 of the electrode 40 and to prevent movement of the electrode 40 relative to the retaining member 220 once released. In one embodiment, at least one retaining member 220 is shaped in an arcuate configuration with the center of such an arch extending away from the periphery of the ridge 214. In a preferred embodiment, the at least one retaining member 222 of each electrode 40 may include two arcuate members 220 disposed in opposite directions and transverse to the longer length 214L of each ridge 214.

In the configuration shown in fig. 3A, the at least one retaining member may have a first set of retaining members 220a, 220b and a second set of retaining members 220c, 220d of the retaining members 220 spaced apart along the spine. The first set of retaining members includes two arcuate members 220a, 220b disposed in opposite directions and transverse to the longer length 214L of each ridge 214 and the second set of retaining members includes two arcuate members 220c, 220d disposed in opposite directions and transverse to the longer length 214L of each ridge 214 such that each electrode 40 is captured between the first set of retaining members 220a, 220b and the second set of retaining members 220c and 220d.

Fig. 3B shows a ridge structure 38a formed from a tube blank. Also within the scope of the present invention, the ridge structure 38a is formed from a flat sheet stock, cut, and heat treated to obtain the spherical basket shape shown herein. The ridge structure 38a shown in fig. 3B may be longitudinally compressed and the ridges 214 may radially expand to form the basket-shaped ridge structure shown in fig. 3A of the basket assembly 38 shown in fig. 2A.

Fig. 4A and 4B illustrate the distal portion 39 (fig. 2A), wherein the distal portion 39 of the basket assembly 38 of the medical probe 22 can be considered flattened between two flat glass sheets. In this viewing configuration, it can be seen that in fig. 4A, distal portion 39 defines a clover-like structure 300, and thus structure 300 will be referred to hereinafter as a "clover". As previously described, the basket 38 in fig. 4A and 4B has a plurality of ridges 214 extending along the longitudinal axis 86 from the proximal central proximal ridge portion 36 to the distal ridge portion 39.

In fig. 4A, the distal spine portion 39 defines a clover configuration 300 (fig. 4A) disposed radially about the longitudinal axis 86. Each clover cutout 212 is aligned along radial axes A, B, C, D, E and F extending orthogonally to axis 86 such that the plurality of ridges 214 extend from the proximal central ridge portion 36 in an equiangular pattern such that the respective angles between the respectively adjacent ridges are about equal. Although the preferred embodiment includes six ridges, it is within the scope of the invention to have any number of ridges from four to twelve.

Notably, the clover structure 300 also defines a central cutout C0 having a negative or empty area A0 disposed about the longitudinal axis 86. In particular, clover structure 300 may be depicted by the following structure: the sinusoidal clover member 300 extends in a certain direction (e.g., counter-clockwise or clockwise) about the longitudinal axis 86 from one ridge 214 to an adjacent ridge 214. This characteristic of sinusoidal structure 300 can be seen in fig. 4B, where, for example, ridges 214 are positioned on radial axis a. Starting from this ridge 214 on axis a, the sinusoidal clover member 300 is configured such that the member meanders around a portion of the cutout 212, as indicated by the dashed line 302, which has a negative or open first area A1, which can be approximated by a circle R1. As used herein, the term "open area" means that there is no solid structure present to define empty spaces. This first open area A1 is approximately 20% of the central area A0. For convenience, the first open area A1 may be approximated by a first virtual circle R1 that positions its center at a first distance L1 from the longitudinal axis 86. Continuing in fig. 4B, sinusoidal clover member 300 meanders in a counter-clockwise direction from axis a about second open area A2 to axis F toward adjacent ridges 214 positioned on axis F. For convenience, the second open area A2 may also be approximated by a second virtual circle R2 having a second open area A2 of about 90% of the first open area A1. It should be noted that the second virtual circle may have its center of radius R2 positioned at a second distance L2 from the longitudinal axis 86 that is less than the first distance L1. Continuing toward axis F in fig. 4B, sinusoidal clover member 300 meanders along dashed line 302 around a third open area A3, which is approximated for convenience by a third virtual circle having a radius R3. The third virtual circle has its center of radius R3 positioned at a third distance L3 from longitudinal axis 86 that is greater than L2 and approximately equal to first distance L1. Once the sinusoidal clover member 300 passes through the axis F, the structural naming is repeated again, wherein the other side of the axis F closer to the axis E has another first open area A1, on which side the sinusoidal clover member 300 meanders towards the next ridge 214 positioned on the axis E, as indicated by the dashed line 302.

In FIG. 4B, the width T0 of the ridge 214 may be 0.25mm to 1mm, while the sinusoidal member 302 has a maximum width T1 of about 1/2 of the width of T0 and a minimum width T2 of about 1/3 of the ridge width T0. The width T3 near the ridge axis (A, B, C, D, E or F) is about the same as the maximum width T1. The central area A0 approximated by the radius R0 is about 0.8 square millimeters and the fourth virtual circle C4 may have an area that is about 14 times the central area A0. Each of the first and third virtual circles R1, R3 is positioned at a first distance L1 of about 1.5mm from the central axis 86, while the second virtual circle R2 is positioned at a distance L2 of about 1/2 of the first distance L1.

Preferably, the plurality of ridges 214 may be made of a material selected from the group consisting of nitinol, cobalt chromium, stainless steel, titanium, and combinations or alloys thereof. Each electrode 40 may be made of a material selected from the group consisting of stainless steel, cobalt chromium, gold, platinum, palladium, and alloys or combinations thereof.

The inventors have designed the clover structure 300 to allow the basket assembly 38 to compress from about 12mm maximum diameter of the basket to fit within an 8-12 french sheath without deforming or causing permanent plastic deformation of the ridges 214 at any portion of the basket assembly 38. In an alternative embodiment, if the number of ridges increases, the sheath may be increased in size to a maximum of 14.5 french to accommodate additional ridges. With the benefit of this design, the inventors have been able to compress the basket into the sheath and then expand to fully expand at least 40 times without any signs of physical deformation.

Referring back to fig. 4A, it should be noted that the sinusoidal clover member 300 is configured such that a portion of the clover member 300 is tangential to the central circle C0 near a position between any two radial axes where two adjacent ridges 214 are located. For example, where the ridge 214 on the radius axis a is adjacent the ridge 214 on the axis B, the sinusoidal clover member 300 is tangent to the open circle C0 at a location that bisects the two radial axes a and B by the line Q1 angle connected to the central axis 86. This tangential nature of the sinusoidal clover member 300 about the open area A0 is repeated for any two adjacent ridges 214 (e.g., ridges 214 on axis B and ridges 214 on axis C, and so on) for all bisected axes Q1, Q2, Q3, Q4, Q5, Q6. Bisecting axes Q1, Q2, Q3, Q4 correspond to peaks of sinusoidal clover member 300 and radial axis A, B, C, D, E, F corresponds to valleys of the sinusoidal clover member, with peaks of the sinusoidal members closer to central axis 86 and Gu Gengyuan from central axis 86.

Another notable feature of basket structure 38 is the concave surface 305 of distal central portion 211 (fig. 3A), which can be seen with reference to fig. 5A and 5B. In fig. 5A, it can be seen that the clover structure 300 is curved such that its open center 211 is contiguous with the plane defined by the central circle C0 and is spaced apart by a gap G relative to the plane defined by the fourth virtual circle C4 surrounding the clover structure 300. The concave surface is indicated by the virtual circle 88 and the dashed line 305, representing the compound curvature generated by the clover structure 300 about the central axis 86.

Fig. 6A shows an end front view of an electrode 40 according to an embodiment of the invention, and fig. 6B shows the same electrode in a top-down perspective view of the electrode 40. Each electrode 40 is made of a biocompatible, electrically conductive material, such as stainless steel, cobalt chromium, platinum, palladium, iridium, or gold, as well as alloys or combinations of such metals. Each end of the electrode 40 (one shown in fig. 6A) has a generally flat planar surface 82 surrounding the lumen 70 and a curved outer surface 80 surrounding the planar surface 82. The electrode 40 has a tissue-facing surface with a generally planar top surface 78 and a curved outer periphery 80 surrounding the generally planar top surface 78. Lumen 70 (i.e., a hollow through-hole) extends therethrough along longitudinal axis 86. In addition to contacting the outer surface of tissue, each given electrode 40 has an inner surface 76 defined by its lumen 70, through which lumen 70 the ridges 214 may be inserted and positioned. Wires or electrical traces 41 (fig. 2C, sized to deliver a current pulse of at least 10 amps) can be connected to connection points on the electrodes (outer or inner surfaces). Preferably, wire 41 is electrically connected to connection point 43 on inner surface 76 of lumen 70. The cross-section of the electrode may be oval, trapezoidal or substantially oval or trapezoidal in shape, as shown in fig. 6A and 6B.

Fig. 7A is a perspective view of another exemplary basket assembly 38b in an expanded form and including a medical probe coated distal end 39. The distal end 39 includes an atraumatic coating 45 configured to reduce the likelihood of tissue damage due to pressure of the distal end 39 of the basket assembly 38b against tissue. The coating 45 covers the sinusoidal member 300 and covers the central incision A0 surrounded by the sinusoidal member 300. As will be appreciated by those skilled in the art, the coating 45 may be applied to alternative configurations of the basket assembly 38b to reduce the likelihood of tissue damage due to pressure of the distal end 39 of the basket assembly 38b against tissue. The coating 45 may be particularly suitable for basket assembly structures having an open distal end. The coating 45 may also be particularly suitable for basket assembly structures having struts or structures with edges positioned at the distal end of the basket assembly. In addition, the coating 45 serves to electrically isolate some or all of the ridges 214, which allows the electrode 40 to be placed more distally than would otherwise be the case, as the electrode needs to be spaced from the exposed conductive surface to avoid arcing.

Fig. 7B shows a ridge structure formed from a tube blank and including a coating 45 at the distal end. The coating 45 preferably comprises a polymeric material. The coating 45 may be applied to the basket assembly 38b by immersing the distal end 39 in a liquid polymer and curing the polymer to form a flexible film. The distal end 39 may be immersed when the basket assembly is in the expanded form as shown in fig. 7A, when the basket assembly collapses to a tubular shape similar to that shown in fig. 7B, or in a partially expanded state between the states shown in fig. 7A and 7B. When the coating 45 is cured to assume its final shape, the distal end 39 may expand to an expanded form as shown in fig. 7A.

Fig. 7C shows a perspective view of the distal end 39 of another exemplary basket assembly 38C in an expanded form and including a coating 45a having a central opening 47. The central opening 47 may allow the basket assembly 38c to collapse more easily than the coating 45 shown in fig. 7A and 7B.

Fig. 8A shows a perspective view of a medical probe 22 having an exemplary basket assembly 38d that includes ridges 214 (each ridge including closely spaced pairs of electrodes 40a, 40 b) and a sheath 217a extending over a proximal portion 306 (fig. 10) of clover 300. The electrodes of each electrode pair 40a, 40b have an edge-to-edge spacing S1 between the electrodes of the electrode pair. The electrode pairs 40a, 40b are positioned in an alternating pattern with electrode pairs 40a positioned more distally on every other ridge 214 and electrode pairs 40b positioned more proximally on every other ridge 214. Basket assembly 38b defines an equator E1 perpendicular to longitudinal axis 86 where the circumference of the basket shape is greatest. The proximal electrode pair 40b is entirely proximal to the equator E1. The equator E1 crosses the proximal electrode of each of the distal electrode pairs 40 a.

Fig. 8B shows a distal end view of the basket assembly 38d shown in fig. 8A. The inner arc 304 of the clover 300 is exposed, while the outer portion 306 (fig. 10) of the clover 300 is covered by the sheath 217a to provide the atraumatic distal end 39 of the basket assembly 38 d. In fig. 10, the inner arc 304 and the covered outer portion 306 of the clover 300 are indicated. A second length L2 from the longitudinal axis L-L to the center of the second virtual circle A2 (fig. 4B) defines a boundary between the inner arc 304 and the outer portion 306 of the clover 300. A majority of each outer portion 306 (fig. 10) is covered by a respective sheath 217a. A majority of the inner arc 304 is exposed to the environment. The distal portion of each sheath 217a tapers outwardly and inwardly following the curvature of the respective proximal portion 306 (fig. 10) of the clover 300 covered by the sheath 271 a. When the basket assembly is inflated, the distal portions of each sheath 217a abut each other at the distal end 39 of the basket assembly 38 d. The distal end of the sheath 271a can be heat set closed and/or heat fused. Additionally or alternatively, a small amount of a polymeric adhesive or epoxy may be applied to the distal end of each sheath 217a to seal the sheath 217a to the ridge 214.

Fig. 8C shows a side view of two adjacent ridges 214 of the basket assembly 38d shown in fig. 8A in a collapsed form for delivery. For simplicity of illustration, only two ridges 214 are shown. Each ridge 214 has a length L4 measured from the distal end of shaft 84 to the distal end of clover 300 (at the apex of distal arc 304). The equator E1 is positioned approximately at the midpoint of the length L4 of the ridge 214. The electrode pairs 40a, 40b are positioned such that the electrode pairs 40a, 40b on adjacent ridges 214 do not overlap along the length L4 of the ridges 214. When basket assembly 38d collapses for delivery, the electrodes of distal electrode pair 40a are fully distal to the electrodes of proximal electrode pair 40 b.

Fig. 9 shows a perspective view of a medical probe 22 subjected to a lateral force F1 and a resulting lateral displacement D1. The amount of lateral displacement D1 for a given force F1 defines the lateral stiffness of the basket 38. The smaller the displacement D1, the greater the stiffness. The desired lateral stiffness may be determined based on qualitative feedback from the physician or other user of the medical probe 22.

Fig. 10 illustrates selected dimensions of a clover structure 300 that may be tailored to achieve the desired mechanical characteristics of basket assembly 38. The radius R1 of the first open area A1, the radius R2 of the second open area A2, the radius R3 of the third open area A3, and the minimum width T2 of the sinusoidal member 302 may each be adjusted to achieve desired mechanical properties. These dimensions are also shown in fig. 4B. In addition, the height H1 may be adjusted to achieve desired mechanical properties. The height H1 is measured from the innermost point of the second open area A2 to the neck 218, which is directly radially outward from the second open area A2 away from the longitudinal axis L-L. The neck 218 is positioned where adjacent proximal portions 306 of the clover structure 300 are closest to each other. The minimum width T2 may be positioned near the perimeter of sinusoidal member 302.

Three radii R1, R2, R3, height H1, and width T2 may be given acceptable ranges based on geometry. The acceptable range may be determined based on manufacturability (e.g., ability to cut from a tube or sheet), overall size of the clover structure 300, and the like. The thickness of the tube or sheet may be given an acceptable range based on the geometry and desired mechanical properties. The desired curvature indicated by the virtual circle 88 in fig. 5A and/or the complex curve 305 in fig. 5B may also be considered. If the ridges are cut from a tube or sheet, a virtual circle 88 may be obtained.

The mechanical properties considered may include lateral stiffness as shown in fig. 9 and peak stresses observed during retraction of basket assembly 38 into the sheath or intermediate catheter. The range of acceptable lateral stiffness may be predetermined (e.g., based on qualitative physician feedback), and the maximum peak strain during retraction of basket assembly 38 may be predetermined to ensure that the basket assembly does not plastically deform. The first radius R1, the second radius R2, the third radius R3, and the height H1 may be configured to provide a lateral stiffness of the expandable basket assembly within a predetermined range. The first radius R1, the second radius R2, the third radius R3, and the height H1 may be configured to provide a maximum peak strain during retraction of the expandable basket assembly into the intermediate conduit such that the maximum peak stress is less than a predetermined threshold. The maximum peak stress may be determined based on peak von mises stress during sheath insertion or retraction. Several acceptable combinations of dimensional variables (R1, R2, R3, H1, T2) shown in fig. 10 may be identified as resulting in basket assembly 38 having a lateral stiffness and peak stress within an acceptable range during retraction. Alternatively or in addition, any combination of any suitable dimensions shown in fig. 4B and/or 10 may be varied to result in basket assemblies having a lateral stiffness and/or maximum peak stress within an acceptable range during retraction. Other mechanical properties or geometric considerations may be further considered when selecting dimensional variations of the basket assembly.

In one embodiment, the first radius R1 and the third radius R3 are each measured about 0.008 inches; the second radius R2 is measured to be about 0.0095 inches; height H1 is measured as about 0.0244 inches; and a width T2 measured about 0.006 inches. In one embodiment, the first radius R1 and the third radius R3 are each measured at about 33% of the height H1, the second radius R2 is measured at about 39% of the height, and the width T2 is measured at about 25% of the height H1. The width T2 is the minimum width of the sinusoidal member. The thickness of the tube or sheet from which the ridges 214 and clover structure 300 are cut may have a thickness of about 0.004 inches, such that the resulting ridges 214 and clover structure 300 have a thickness of about 0.004 inches.

Fig. 11A, 11B and 11C illustrate distal end views of exemplary clover structures 300a, 300B, 300C in which the three radii R1, R2, R3, height H1 and width T2 illustrated in fig. 10 vary. In these examples, the radius R1 of the first open area is set equal to the radius R3 of the third open area. The three structures 300a, 300b, 300c present a possible clover design suitable for the medical probe 22, wherein a range of lateral stiffness and a range of peak stresses are observed during retraction of the basket assembly 38 into the sheath or intermediate catheter.

Fig. 12 shows an exploded view of the medical probe 22. The spine 214 may be attached to the spine retention hub 90 to form the basket assembly 38. A ridge retaining sleeve 93 may be provided on the ridge retaining hub 90 to help secure the ridge 214 in place. The contact force sensor assembly 400 may be coupled to the ridge retention hub 90. The contact force sensor assembly 400 may be disposed in the contact force sensor assembly sleeve 91. The contact force sensor assembly sleeve 91 can be coupled to a proximal coupler 97, which can be coupled to the tubular shaft 84. When fully assembled, basket assembly 38 may be attached to tubular shaft 84 by the components just described to enable medical professional 34 to insert medical probe 22 into heart 26 of patient 28.

The ridge retention hub 90 may include a cylindrical member 94 including a plurality of relief slots 96, a plurality of flushing openings 98, and at least one ridge retention hub electrode 99 (shown in fig. 2), or some combination thereof. The relief slots 96 may be provided on an outer surface of the cylindrical member 94 and configured to allow a portion of each ridge 214 (such as each ridge attachment end 216) to fit into the corresponding relief slot 96 of the retention hub 90.

Fig. 13A shows a ridge retaining hub 90. The relief slot 96 may include an undercut 96a extending along the longitudinal axis to allow insertion of the ridge attachment end 216. The relief slot 96 may be provided with a tab 96b that engages with a complementary recess on the ridge retaining end 216 to prevent twisting of the ridge attachment end 216 of each ridge 214 relative to the retaining hub 90. This configuration of the attachment end 216 allows the plurality of ridges 214 at the proximal portion of the basket 38 to function as a single structural member with the retention hub 90. The ridge retention hub 90 may also serve as a coupler to contact the force sensor assembly 400. The attachment end 216 (fig. 12) 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 38 is deployed.

Fig. 13B is an illustration of the contact force sensor assembly 400 disconnected from the hub 90. As shown, the contact force sensor assembly 400 may include a proximal end 402 and a distal end 403. The distal end 403 is inserted into the cylindrical member 94 of the retention hub 90. The proximal end 402 may house one or more magnetic field sensors and the distal end may house a magnetic field generator coil. The magnetic field generator coil may be configured to generate a magnetic field, and the one or more magnetic field sensors may be configured to detect the presence and magnitude of the magnetic field.

The contact force sensor assembly 400 can include a female connector 406 and the ridge retention hub 90 can include a male connector 408. However, it is understood that while a contact force sensor assembly 400 having a female connector 406 and a ridge retention hub 90 having a male connector 408 are shown and described for convenience, these two components may be switched back and forth without departing from the scope of the present disclosure. In other words, the contact force sensor assembly 400 may include a male connector 408, while the ridge retention hub 90 may include a female connector 406, depending on the particular configuration. It will be appreciated that the contact force sensor assembly 400 may include a plurality of female connectors 406, while the ridge retention hub 90 may include a plurality of male connectors 408. Alternatively, the contact force sensor assembly 400 may include both female and male connectors 406, 408, while the ridge retention hub may include complementary female and male connectors 406, 408.

Female connector 406 and male connector 408 may form a bayonet mount configuration, wherein male connector 408 may interlock with the female connector to couple contact force sensor assembly 400 to ridge retention hub 90. In other words, the female connector 406 may include a slot forming a generally "L" shape and the male connector 408 may include a protrusion forming a generally complementary "L" shape. In other words, the female connector 406 may include a slot having a first slot portion extending generally longitudinally from the distal end 403 of the contact force sensor assembly 400 into the contact force sensor assembly 400 and a second slot portion extending generally transversely from an end of the first slot portion. Similarly, the male connector 408 may include a protrusion having a first protruding portion extending generally longitudinally away from the ridge retention hub 90 and a second protruding portion extending generally transversely from an end of the first protruding portion.

The irrigation hub 90 may include a cylindrical member 94 extending along the longitudinal axis 86. The cylindrical member 94 can have a first outer diameter 410 at a proximal end 412 of the cylindrical member 94. The cylindrical member 94 can have a recess extending inwardly along the longitudinal axis 86 to form an inner portion 111. The distal end 108 has a second outer diameter 420 that is smaller than the first outer diameter 410.

The contact force sensor assembly 400 can further include a deflection portion 404 disposed between the proximal end 402 and the distal end 403. The deflection portion 404 may be configured to deflect when a force is applied to the contact force sensor assembly 400. In other words, the deflecting portion 404 may be configured to allow the proximal end 402 and distal end 403 of the contact force sensor assembly 400 to move closer together when a force is applied to the contact force sensor assembly 400. In one example, the deflection portion 404 may include a coil spring formed into the body of the contact force sensor assembly 400. For example, a helical cut may be formed in the body of the contact force sensor assembly 400 to form a helical spring. In this way, the body of the contact force sensor assembly 400 itself may form a spring without requiring additional components. In other examples, a spring may be assembled between the proximal end 402 and the distal end 403 to form the contact force sensor assembly 400. The contact force sensor assembly 400 may be disposed inside the tube 84 (fig. 2) and proximal with respect to the basket assembly 38 (fig. 12) and as close as possible to the basket assembly 38 such that contact with heart tissue via the ridges 214 may be transferred to the contact force sensor assembly 400.

It will be appreciated that the magnetic field sensor housed in the proximal end 402 may detect a change in the magnitude of the magnetic field force generated by the magnetic field generator coil housed in the distal end 403 as the proximal end 402 moves closer to the distal end 403 when a force is applied to the contact force sensor assembly 400. Since the spring constant K of the deflection portion 404 may be predetermined and the distance between the magnetic field generator coil and the magnetic field sensor may be detected, the force applied to the medical probe 22 may be determined (e.g., by using hooke's law, or the equation f=d×k). Further, the contact force sensor assembly 400 may receive electrical signals from and provide electrical signals to the console 24 to process the received signals and determine the force (e.g., acrylic) applied to the basket assembly 38.

Fig. 14A is a schematic illustration showing a top perspective view of a flush hub 90 in accordance with the disclosed technology, and fig. 14B is a schematic illustration showing a bottom perspective view of a flush hub 90 in accordance with the disclosed technology. The irrigation hub 90 may additionally or alternatively be configured to retain a proximal spine end (similar to the spine retention hub 90 shown in fig. 2A). The irrigation hub 90 may be configured to deliver fluid to the electrode 40 of the medical probe 22. As shown in fig. 14A, the irrigation hub 90 may include a cylindrical member 94 including a proximal end 103a and a distal end 103b. As shown, the proximal end 103a may have an outer diameter that is greater than the outer diameter of the distal end 103b.

The irrigation hub 90 may include a plurality of irrigation openings 98, which may be configured to allow fluid to flow therethrough and to help direct fluid outwardly from the irrigation hub 90. The irrigation openings 98 may be radially dispersed about the distal end 103b and generally transverse to the longitudinal axis 86. The rinse openings 98 may each form a hole having an inlet region 105a that is smaller than an outlet region 105b so as to allow the fluid to disperse outwardly when the fluid is directed outwardly from the rinse openings 98. In other words, as fluid flows through the irrigation hub 90 and out of the irrigation openings 98, the inlet region 105a through which fluid first flows will be smaller than the outlet region 105b through which fluid flows just prior to exiting the irrigation hub 90. In this manner, the irrigation hub 90 may help direct or channel irrigation fluid outwardly toward the electrode 40 or at least from the irrigation hub 90.

The flush hub 90 may also include a plurality of relief grooves 96 that may be configured to receive and help retain the ridges 22. As shown in fig. 2A, the ridges 214 may each include a ridge attachment end 216 that may be configured to be at least partially inserted into the relief groove 96 such that the ridges 214 may be secured in place when assembled with the irrigation hub 90.

The irrigation hub 90 may also include a sensor mount 108, which may be disposed at the distal end 103b of the cylindrical member 94. The sensor mount 108 may be configured to receive and support a sensor 608 (fig. 16) of the medical probe 22. In some examples, the sensor 608 may be a reference electrode configured to detect far-field signals, such as when the electrode 40 is used to map electrical signals dispersed through tissue, which may be used to process and filter signals detected by the electrode 40. In other examples, the sensor may be or include one or more magnetic position sensors that may be used to detect magnetic fields output by one or more magnetic field generators to determine the position and/or orientation of the basket catheter 22.

As shown in fig. 14B, the proximal end 103a of the cylindrical member 94 may include a recess extending inwardly along the longitudinal axis 86 and forming an inner portion 111. The irrigation hub 90 may also include an irrigation coupling 110, which may be configured to receive or otherwise connect to an irrigation supply tube 200 (as shown in fig. 17). The cylindrical member 94 can also include a flush inlet chamber 112, which can be disposed distally of the flush coupling 110 and proximally of the inner portion 111. The flush inlet chamber 112 may be configured to receive fluid from the flush supply tube 200. The irrigation supply tube 200 may fluidly separate the fluid from the inner portion 111, the combination sensor 608, the tubular shaft 84, and other components of the medical probe. In other words, fluid may be delivered to the flush inlet chamber 112 via the flush supply tube 200 without the fluid coming into contact with other internal components of the medical probe. The flush inlet chamber 112 may be sized to receive a sufficient amount of fluid from the flush supply tube 200 such that the flow of fluid is generally unobstructed. In some examples, the flush inlet chamber 112 may have an inner diameter equal to the inner diameter of the flush supply tube 200. The flush inlet chamber 112 may be fluidly connected to the plurality of flush openings 98 such that fluid may flow through the flush inlet chamber 112 and be directed out of the plurality of flush openings 98. The irrigation opening 98 may be disposed from a distal portion of the irrigation inlet chamber 112 generally transverse to the longitudinal axis 86.

The irrigation hub 90 may also include a plurality of attachment mechanisms 116, which may be configured to attach the irrigation hub 90 to the combination sensor 608 and/or the tubular shaft 84. The attachment mechanism 116 may be, for example, but not limited to, a bayonet mount, a snap connector, a threaded fitting, or other suitable type of attachment mechanism 116 for a particular application.

Fig. 15A-15C illustrate various views of the irrigation hub 90. In particular, fig. 15A shows a side view of a rinsing hub 90 according to the disclosed technology, fig. 15B shows a top view of the rinsing hub according to the disclosed technology, and fig. 15C shows a bottom view of the rinsing hub according to the disclosed technology. Each of the reference numbers shown in fig. 15A-15C corresponds to various components and/or features described herein.

Fig. 16 shows a cross-sectional view of a flush hub 90 in accordance with the disclosed technology. As shown in fig. 16, the irrigation hub 90 may include a shunt 120 disposed at a distal end of the irrigation inlet chamber 112 and extending inwardly into the irrigation inlet chamber 112. By extending inwardly into the flush inlet chamber 112, the flow splitter 120 can block fluid flow and redirect fluid flow out of the flush opening in a direction generally transverse to the longitudinal axis 86 or at an angle to the longitudinal axis 86. In some examples, the shunt 120 may be a tapered member having an outer surface extending away from the longitudinal axis 86 at an angle θ. The angle θ may be a predetermined angle sufficient to redirect fluid received from the irrigation supply tube 200 out of the plurality of irrigation openings 98 such that the fluid is directed generally transverse to the longitudinal axis 86. In some examples, the angle θ may direct fluid toward the electrode 40. As non-limiting examples, the angle θ may be about 15 °, 20 °, 25 °, 30 °, 35 °, 40 °, 45 °, 60 °, 75 °, 85 °, or any other suitable angle for a particular application. Although described as a tapered member, the flow splitter may include other shapes having generally flat sides, generally curved sides, or other configurations in which fluid may be directed outwardly by the flow splitter 120 through the plurality of irrigation openings 98.

As will be appreciated, the flush opening 98 may extend outwardly from the flush inlet chamber 112 through the flush hub 90. As previously described, the rinse opening 98 may include an inlet region 105a that is smaller than an outlet region 105 b. The inlet region 105a may be proximate to the flush inlet chamber 112 and the outlet region 105b may be disposed at a distance away from the flush inlet chamber 112. The surface 122 of the rinse opening 98 may extend between the inlet zone 105a and the outlet zone 105 b. The surface 122 may be configured such that the surface is disposed at an angle θ or substantially similar to the angle θ such that the fluid may be directed outwardly through the irrigation opening 98 without generating significant turbulence.

Fig. 16 also shows a sensor 608 attached to the sensor mount 108. As described above, the sensor may be a magnetic position sensor, a reference electrode, or any other sensor for a particular configuration. Although the sensor 608 is shown disposed about or through the sensor mount 108, the sensor 608 may also be disposed at a more distal end of the sensor mount 108. In other examples, the sensor mount 108 may be configured to receive and support a plurality of sensors (e.g., a first sensor disposed about the sensor mount 108 and a second sensor disposed at a distal end of the sensor mount 108).

Fig. 17 shows a flow path 230 of fluid through the irrigation hub 90 according to an embodiment of the present invention. As shown in fig. 17, the irrigation fluid may have a flow path 230 extending through the irrigation supply tube 200 and be redirected outwardly by the irrigation hub 90. In some examples, the irrigation hub 90 may redirect fluid generally transverse to the longitudinal axis 86. In other examples, the irrigation hub 90 may redirect fluid at other angles as described herein to achieve a desired cooling effect at the electrode.

Fig. 18A and 18B illustrate another example basket catheter 728 having a basket assembly 738 with a plurality of electrodes 40a, 40B disposed on the spine 714 and a hub 90 that may function similarly to the hub 90 illustrated elsewhere herein. As shown in fig. 18A, the electrodes 40a, 40b may be disposed on adjacent ridges 714 in alternating groupings of distal electrodes 40a and proximal electrodes 40 b. For example, and as shown in fig. 18A and 18B, two electrodes 40a, 40B may be disposed adjacent to each other on a spine 714, with no additional electrodes 40a, 40B disposed on the same spine 714. On a first ridge 714, two electrodes 40b may be disposed together near the proximal end of the ridge 714, while on a second adjacent ridge 714, two electrodes 40a may be disposed together near the distal end of the adjacent ridge 714. In this way, the electrodes 40a, 40b may be offset around the circumference of the basket catheter 728, enabling the basket assembly 738 to better collapse when retracted into the sheath. When basket assembly 738 collapses, distal electrode 40a is fully positioned in the distal direction of proximal electrode 40b with a gap between proximal electrode 40b and distal electrode 40a along longitudinal axis 86.

With the configuration of the electrodes 40a, 40B disposed on the spine 714 as shown in fig. 18A and 18B, the system 10 (fig. 1) may be configured to output bipolar high voltage DC pulses, such as may be used to effect irreversible electroporation (IRE) between two adjacent electrodes 40a, 40B on a given spine 714, electrically connect the two adjacent electrodes 40a, 40B on a given spine 714 and output bipolar high voltage DC pulses between one or more electrodes 40a, 40B on another spine 714 of the basket assembly 738, and/or output unipolar high voltage DC pulses between one or more electrodes 40a, 40B and one or more electrode patches 44 (fig. 1) disposed on the skin of the patient 28. The two electrodes 40a, 40b on a given ridge 714 may include an insulating material 727 disposed between the two electrodes 40a, 40b, thereby electrically isolating the two electrodes 40a, 40b of the electrode pair from each other.

The spine 714 may be covered with an insulative bushing or sheath 717, which may be disposed between the electrodes 40a, 40b and the frame of the spine 714. The insulating bushing 717 can electrically isolate the electrodes 40a, 40b from the frame of the spine 714 to prevent arcing or shorting to the frame of the spine 714. An insulation bushing 717 may extend from the hub 90 to the distal end 39 of the basket assembly 738.

Fig. 18B is an illustration of basket assembly 738 with insulating sleeve 717, a pair of distal electrodes 40a and a pair of proximal electrodes 40B, and other ridge elements removed for purposes of illustration, such that the frame of basket assembly 738 is visible. The ridges 714 extend from the hub 90 and are joined together by the clover structure 300 near the distal end 39 of the basket assembly 738. The clover structure 300 may be configured similar to the clover structure or variations thereof disclosed in more detail elsewhere herein. The insulating bushing 717 may include a flared end 717a (fig. 18A) extending over a majority of the clover structure 300 (fig. 18B) and may provide an atraumatic distal surface at the distal end 39 of the basket assembly 738. In this manner, the insulating bushing or sheath 717 may prevent the frame of the basket assembly 738 from damaging tissue.

As shown in fig. 18B, the spine 714 may also include electrode-holding regions 760a, 760B configured to prevent the electrodes 40a, 40B from sliding proximally or distally along the spine 714. Adjacent ridges 714 may have ridge retaining regions 760a, 760b that alternate between proximal and distal positions along the ridge 714. That is, a first spine 714 may have an electrode-holding region 760b disposed near the proximal end of the spine 714, and an adjacent spine 714 may have an electrode-holding region 760a disposed near the distal end of the spine 714.

Each electrode-holding region 760a, 760b may include one or more cutouts 764 that may allow the ridges 714 to flex or contract inwardly. The plurality of ridges 714 includes a first ridge having a distal electrode holding region 760a and a second ridge having a proximal electrode holding region 760 b. The first ridge 714 has a single cross-section that extends from the proximal portion of the first ridge to approximately the midpoint of the first ridge and thereafter splits into at least two discrete cross-sections (above the electrode-holding region 760 a) that reach the distal ridge portion of the first ridge (at the clover structure 300). The second ridge 714 has at least two discrete cross-sections that extend from a proximal portion of the second ridge (above the electrode-holding region 760 b) to approximately the midpoint of the second ridge, and thereafter combine into a single cross-section that extends to a distal ridge portion of the second ridge.

Each electrode-retaining region 760a, 760b may also include one or more retaining members 762a-c that protrude outward and may be configured to prevent the electrodes 40a, 40b from sliding proximally or distally along the ridge 714. During manufacture, the proximal end of the frame of basket assembly 738 is inserted into the lumen of electrodes 40a, 40b, and electrodes 40a, 40b are slid distally along ridges 714 to their respective final positions. Cutouts 764 allow electrodes 40a, 40b to slide over retaining members 762 a-c. Due to the one or more cutouts 764 in the spine 714, the retaining members 762a-c may be configured to move inwardly as the spine 714 contracts inwardly to allow the electrodes 40a, 40b to slide over the retaining members 762 a-c. Once the electrodes 40a, 40b slide past the retaining member 762, the retaining member 762 may resiliently flex back to its previous position, thereby preventing the electrodes 40a, 40b from sliding proximally or distally along the ridge 714.

The proximal electrode holding area 760b includes a proximal holding member 762c and a distal holding member 762b. The proximal electrode holding region 760b need not be configured to allow the proximal electrode 40b to pass over the distal holding member 762b. Once distal electrodes 40a are in their respective final positions, distal electrode holding region 760a utilizes clover structure 300 to prevent distal movement of distal electrodes 40 a.

While basket conduit 728 is shown with two electrodes 40a, 40b disposed proximate to each other on a given spine 714 and with alternating groupings of electrodes 40a, 40b on adjacent spines 714, the disclosed techniques may include other configurations of electrodes and spines that are not shown. For example, the disclosed techniques may include groupings of three or more electrodes and/or groupings of multiple electrodes disposed on the ridges, and may also include different numbers of ridges. Accordingly, the disclosed techniques are not limited to the particular configuration of electrodes and ridges shown and described herein.

The following clauses list non-limiting embodiments of the present disclosure:

clause 1. A medical probe comprising: an expandable basket assembly configured to be coupled to a distal end of a tubular shaft, the basket assembly comprising: a plurality of ridges extending along a longitudinal axis from a proximal central proximal ridge portion to a distal ridge portion, the distal ridge portion defining a clover structure disposed radially about the longitudinal axis, the clover structure defining a central cutout disposed about the longitudinal axis having a central area, the clover structure comprising a sinusoidal member extending from one ridge to an adjacent ridge in a direction about the longitudinal axis, the sinusoidal member serpentine about: (a) a first virtual circle having a first radius that positions a center thereof at a first distance from the longitudinal axis, (b) a second virtual circle having a second radius that positions a center thereof at a second distance from the longitudinal axis that is less than the first distance, and (c) a third virtual circle having a third radius that is approximately equal to the first radius, the third virtual circle having a center positioned at a third distance from the longitudinal axis that is approximately equal to the first distance, the clover structure further defining a height measured from a point on a periphery of the second virtual circle to a neck that is directly away from the longitudinal axis relative to the second virtual circle and between adjacent first and second virtual circles, the first, second, third and height being configured to provide the transverse inflatable stiffness of the assembly within a predetermined range.

Clause 2. The medical probe of clause 1, the first radius, the second radius, the third radius, and the height being configured to provide a maximum peak stress during retraction of the expandable basket assembly into the intermediate catheter such that the maximum peak stress is less than a predetermined threshold.

Clause 3 the medical probe of clause 1 or 2, wherein the first radius is measured as about 33% of the height, wherein the second radius is measured as about 39% of the height, wherein the third radius is measured as about 33% of the height, and wherein the second radius is measured as about 25% of the height.

Clause 4 the medical probe of any of clauses 1-3, wherein the first radius is measured between 31% and 35% of the height, wherein the second radius is measured between 37% and 41% of the height, wherein the third radius is measured between 31% and 35% of the height, and wherein the second radius is measured between 23% and 27% of the height.

Clause 5 the medical probe of any of clauses 1-4, wherein the central area comprises an area of about 0.8 square millimeters, a fourth virtual circle surrounding the sinusoidal member comprises an area of about 14 times the central area, and each of the first virtual circle and the third virtual circle is positioned at a first distance from the central axis, and the second virtual circle is positioned at a second distance of about 1/2 of the first distance.

Clause 6. The medical probe of clause 5, wherein the sinusoidal member is tangential to the central circle.

Clause 7 the medical probe of any of clauses 1-6, wherein the expandable basket assembly includes a coating covering the sinusoidal member and a central cutout surrounded by the sinusoidal member.

The medical probe of any of clauses 1-6, wherein the expandable basket assembly comprises a coating covering a majority of the sinusoidal member and includes an opening at the longitudinal axis.

Clause 9 the medical probe of any of clauses 1-8, wherein the cross-sectional shape of each electrode comprises a substantially oval or trapezoidal shape.

The medical probe of any one of clauses 1-9, wherein each of the ridges comprises at least one retaining member extending generally transverse to the ridge.

Clause 11 the medical probe of clause 10, further comprising: a plurality of electrodes, wherein each of the plurality of electrodes comprises a body defining a hollow portion extending through the body of the electrode such that a ridge can be inserted into the hollow portion and retained by the at least one retaining member.

Clause 12 the medical probe of clause 10 or 11, wherein the at least one retaining member comprises an arcuate member.

Clause 13 the medical probe of any of clauses 10-12, wherein the at least one retaining member comprises two arcuate members disposed in opposite directions and transverse to the longer length of each ridge.

The medical probe of any of clauses 10-13, wherein the at least one retaining member comprises a first set of retaining members and a second set of retaining members spaced apart along the spine, the first set of retaining members comprising two arcuate members disposed in opposite directions and transverse to the longer length of each spine and the second set of retaining members comprising two arcuate members disposed in opposite directions and transverse to the longer length of each spine such that each electrode is captured between the first set of retaining members and the second set of retaining members.

The medical probe of any of clauses 1-14, wherein the plurality of ridges extend from the proximal central ridge portion in an equiangular pattern such that the respective angles between respectively adjacent ridges are about equal.

The medical probe of any one of clauses 1-15, further comprising a plurality of electrically insulating sheaths, each disposed between a respective ridge of the plurality of ridges and a respective electrode, thereby electrically isolating the respective electrode from the respective ridge.

The medical probe of clause 17, wherein the sinusoidal member comprises an inner arc about the second virtual circle such that the inner arc is positioned entirely less than the second distance from the longitudinal axis, wherein the sinusoidal member comprises an outer portion about the first virtual circle and about the second virtual circle such that the outer portion is positioned entirely more than the second distance from the longitudinal axis, and wherein a majority of the outer portion of the sinusoidal member is covered by a respective one of the electrically insulating sheaths.

Clause 18 the medical probe of clause 17, wherein at least a portion of the inner arc of the sinusoidal member is exposed to the environment.

Clause 19 the medical probe of clause 17 or 18, wherein the distal portion of each of the plurality of electrically insulating sheaths tapers outwardly and inwardly following the curvature of the outer portion of the sinusoidal member.

The medical probe of any one of clauses 17-19, the distal portion of each of the plurality of electrically insulating sheaths abutting the distal portion of an adjacent insulating sheath.

The medical probe of any one of clauses 16-20, further comprising: two electrodes coupled to respective ridges, the two electrodes for each of the plurality of ridges.

Clause 22 the medical probe of any of clauses 16-21, further comprising: wires disposed within respective ones of the plurality of electrically insulating jackets, wherein the wires are electrically connected to the respective electrodes.

Clause 23 the medical probe of any of clauses 1-22, wherein the plurality of ridges comprise a material selected from the group consisting of nitinol, cobalt chromium, stainless steel, titanium, and combinations thereof.

The medical probe of any of clauses 11-23, wherein each electrode comprises a material selected from the group consisting of stainless steel, cobalt chromium, gold, platinum, palladium, and alloys or combinations thereof.

Clause 25 the medical probe of any of clauses 1-24, further comprising: a plurality of electrodes configured to deliver an electrical pulse for irreversible electroporation, the pulse comprising a peak voltage of at least 900 volts (V).

The medical probe of any of clauses 1-25, wherein the plurality of ridges are configured to form an approximately spherical basket assembly when in the expanded form.

The medical probe of any of clauses 1-25, wherein the plurality of ridges are configured to form an approximately oblate basket assembly when in the expanded form.

The medical probe of any one of clauses 1-27, further comprising an irrigation port disposed in the proximal portion of the basket to deliver irrigation fluid to the plurality of electrodes.

The medical probe of any of clauses 1-28, wherein the central cutout approximates a central circle having a central area, and wherein the clover structure is disposed within a fourth circle centered on the longitudinal axis such that a portion of the clover adjacent to the central circle is spaced apart along the longitudinal axis relative to a portion of the clover adjacent to the fourth circle, thereby defining a concave clover structure.

The medical probe of any of clauses 1-29, wherein the clover structure is concave, wherein a center of the clover structure extends toward the proximal central spine portion of the basket to approximate a concave surface disposed about the longitudinal axis.

The medical probe of any one of clauses 1-30, wherein a reference electrode is disposed near the distal end of the tubular shaft.

The medical probe of any one of clauses 1-31, wherein a ridge-retaining hub is coupled to the distal end of the tubular shaft to connect the ridge to the retaining hub.

Clause 33 the medical probe of any of clauses 1-32, wherein a cylindrical protrusion is provided to position the reference electrode on the protrusion.

The medical probe of any of clauses 1-33, wherein the ridge-retaining hub includes an outlet port to allow fluid delivered to the distal end tubular shaft to exit the outlet port into the volume surrounded by the basket ridge.

Clause 35. A method of constructing a medical probe, the method comprising: cutting a tubular frame comprising a plurality of ridges extending along a longitudinal axis from a proximal ridge portion to a distal ridge portion, the distal ridge portion defining a clover structure disposed radially about the longitudinal axis, the tubular frame configured to move from a tubular shape to an expansion basket shape, wherein: the plurality of ridges being curved away from the longitudinal axis, the clover structure defining a central cutout having a central area disposed about the longitudinal axis, the clover structure including a sinusoidal member extending from one ridge to an adjacent ridge in a direction about the longitudinal axis, the sinusoidal member meandering around: (a) a first virtual circle having a first radius, the first virtual circle having its center positioned at a first distance from the longitudinal axis, (b) a second virtual circle having a second radius, the second virtual circle having its center positioned at a second distance from the longitudinal axis that is less than the first distance, and (c) a third virtual circle having a third radius approximately equal to the first radius, the third virtual circle having its center positioned at a third distance from the longitudinal axis that is approximately equal to the first distance, the clover structure further defining a height measured from a point on the perimeter of the second virtual circle to a neck that is directly away from the longitudinal axis relative to the second virtual circle and between adjacent first and second virtual circles; and forming a basket assembly for the medical probe such that the tubular frame provides structural support for the basket assembly and such that the first radius, the second radius, the third radius, and the height are configured to provide lateral stiffness of the expandable basket assembly within a predetermined range.

Clause 36 the method of clause 35, the first radius, the second radius, the third radius, and the height are configured to provide a maximum peak stress during retraction of the expandable basket assembly into the intermediate conduit such that the maximum peak stress is less than a predetermined threshold.

Clause 37 the method of clause 35 or 36, wherein the first radius is measured as about 33% of the height, wherein the second radius is measured as about 39% of the height, wherein the third radius is measured as about 33% of the height, and wherein the second radius is measured as about 25% of the height.

The method of any of clauses 35 to 37, wherein the first radius is measured between 31% and 35% of the height, wherein the second radius is measured between 37% and 41% of the height, wherein the third radius is measured between 31% and 35% of the height, and wherein the second radius is measured between 23% and 27% of the height.

Clause 39 the method of any of clauses 35 to 38, further comprising: aligning the plurality of ridges with a plurality of electrodes, each electrode having a lumen extending through the body of the electrode; each ridge of the plurality of ridges is inserted into the lumen of an electrode of the plurality of electrodes. And holding the plurality of electrodes on the plurality of ridges.

The method of clause 40, wherein holding the plurality of electrodes on the plurality of ridges comprises holding an electrode of the plurality of electrodes by at least one biasing member.

Clause 41 the method of clause 40, wherein the at least one biasing member is disposed outside the lumen of the electrode.

Clause 42 the method of clause 40 or 41, wherein the at least one biasing member is disposed within the lumen of the electrode.

The method of any one of clauses 35 to 42, further comprising: positioning the ridges of the expandable basket assembly through lumens of electrically insulating sheaths of the plurality of electrically insulating sheaths; positioning a wire through the lumen of the electrically insulating sheath; positioning an electrode of the plurality of electrodes over the electrically insulating sheath; and electrically connecting the wire to the electrode through an aperture in the electrically insulating sheath.

Clause 44 the method of clause 43, further comprising: a majority of the sinusoidal members are covered by the plurality of electrically insulating sheaths.

Clause 45 the method of clause 44, the distal portion of each of the plurality of electrically insulating sheaths abutting the distal portion of an adjacent insulating sheath.

Clause 46 the method of clause 44 or 45, further comprising: the method further includes covering a majority of an outer portion of the sinusoidal member with the plurality of electrically insulating sheaths such that the outer portion of the sinusoidal member meanders around the first virtual circle and around the second virtual circle, and such that the outer portion is positioned entirely greater than the second distance from the longitudinal axis.

The method of clause 47, wherein the inner arc of the sinusoidal member remains exposed to the environment such that the inner arc meanders around the second virtual circle and such that the inner arc is positioned entirely less than the second distance from the longitudinal axis.

The method of clause 46 or 47, wherein the distal portion of each of the plurality of electrically insulating sheaths tapers outwardly and inwardly following the curvature of the outer portion of the sinusoidal member.

The method of any one of clauses 35 to 48, wherein each respective ridge of the plurality of ridges comprises a first electrode and a second electrode thereon, the method further comprising: aligning each respective ridge of the plurality of ridges with the first electrode and the second electrode; inserting each respective ridge of the plurality of ridges into the lumen of the first electrode and the lumen of the second electrode; and fitting an end of each respective ridge of the plurality of ridges to the tubular shaft sized to traverse vasculature.

Clause 50 the method of any of clauses 39 to 49, further comprising offsetting the electrodes between adjacent ridges along the longitudinal axis.

The method of any of clauses 39-50, wherein the electrode body lumen is configured to receive the wire of the medical probe.

The method of any of clauses 39 to 51, wherein the wire is insulated from the ridge.

Clause 53 the medical probe of clause 16, further comprising: two electrodes coupled to respective ridges, the two electrodes for each ridge of the plurality of ridges, the plurality of ridges including a first ridge and a second ridge, the first ridge having a single cross-section extending from a proximal portion of the first ridge to approximately a midpoint and thereafter dividing into at least two discrete cross-sections reaching the distal portion of the first ridge, and the second ridge having at least two discrete cross-sections extending from a proximal portion of the second ridge to approximately a midpoint and thereafter combining into a single cross-section extending to the distal portion of the second ridge.

Clause 54 the medical probe of clause 1, further comprising: a flushing hub coupled to the tubular shaft, the flushing hub including a cylindrical member extending along a longitudinal axis, the cylindrical member including: a proximal end having a first outer diameter and a recess extending inwardly along the longitudinal axis forming an inner portion; a distal end having a second outer diameter that is smaller than the first outer diameter; a flush inlet chamber disposed adjacent the interior portion and configured to receive fluid from a flush supply; a plurality of irrigation openings disposed from a distal portion of the irrigation inlet chamber generally transverse to the longitudinal axis; and a shunt extending into the distal portion of the irrigation inlet chamber to block fluid flow and redirect fluid flow out of the plurality of irrigation openings in a direction generally transverse to the longitudinal axis.

Clause 55, the medical probe of clause 1, wherein the clover structure is concave, wherein a center of the clover structure extends toward the proximal central ridge portion of the basket to approximate a concave surface disposed about the longitudinal axis, further comprising: a contact force sensor assembly disposed at the distal end of the tubular shaft and configured to detect a force applied to the medical probe, the contact force sensor assembly comprising: a first bayonet mount portion comprising a component of the contact force assembly; a spine retention hub including a plurality of slots to receive respective spine members of the expandable basket assembly; and a second bayonet mount portion configured to couple the ridge retention hub to the contact force sensor assembly by interlocking with the first bayonet mount portion.

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 and illustrated above, 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 medical probe, comprising:

an expandable basket assembly configured to be coupled to a distal end of a tubular shaft, the basket assembly comprising:

a plurality of ridges extending along a longitudinal axis from a proximal central proximal ridge portion to a distal ridge portion, the distal ridge portion defining a clover structure disposed radially about the longitudinal axis, the clover structure defining a central cutout disposed about the longitudinal axis having a central area, the clover structure comprising a sinusoidal member extending from one ridge to an adjacent ridge in a direction about the longitudinal axis, the sinusoidal member serpentine about:

(a) A first virtual circle having a first radius, the first virtual circle having its center positioned at a first distance from the longitudinal axis,

(b) A second virtual circle having a second radius, the second virtual circle having its center positioned at a second distance from the longitudinal axis that is less than the first distance, and

(c) A third virtual circle having a third radius approximately equal to the first radius, the third virtual circle having its center positioned at a third distance from the longitudinal axis approximately equal to the first distance,

the clover structure further defines a height measured from a point on the perimeter of the second virtual circle to a neck, the neck being directly distant from the longitudinal axis relative to the second virtual circle and located between adjacent first and second virtual circles,

the first radius, the second radius, the third radius, and the height are configured to provide a lateral stiffness of the expandable basket assembly within a predetermined range.

2. The medical probe of claim 1, the first radius, the second radius, the third radius, and the height being configured to provide a maximum peak stress during retraction of the expandable basket assembly into an intermediate catheter such that the maximum peak stress is less than a predetermined threshold.

3. The medical probe according to claim 1,

Wherein the first radius is measured to be about 33% of the height,

wherein the second radius measures about 39% of the height,

wherein the third radius measures about 33% of the height, and

wherein the minimum width of the sinusoidal member is measured to be about 25% of the height.

4. The medical probe according to claim 1,

wherein the first radius is measured between 31% and 35% of the height,

wherein the second radius is measured between 37% and 41% of the height,

wherein the third radius is measured to be between 31% and 35% of the height, and

wherein the minimum width of the sinusoidal member is measured between 23% and 27% of the height.

5. The medical probe of claim 1, wherein the central area comprises an area of approximately 0.8 square millimeters, a fourth virtual circle surrounding the sinusoidal member comprises an area approximately 14 times the central area, and each of the first virtual circle and the third virtual circle is positioned at a first distance from the longitudinal axis, and the second virtual circle is positioned at a second distance that is approximately 1/2 of the first distance.

6. The medical probe of claim 5, wherein the sinusoidal member is tangential to a central circle of the central area.

7. The medical probe of claim 1, wherein each of the ridges includes at least one retaining member extending generally transverse to the ridge.

8. The medical probe of claim 7, further comprising:

a plurality of the electrodes are arranged on the substrate,

wherein each electrode of the plurality of electrodes comprises a body defining a hollow portion extending through the body of the electrode such that a ridge can be inserted into the hollow portion and retained by the at least one retaining member.

9. The medical probe of claim 7, wherein the at least one retaining member comprises an arcuate member.

10. The medical probe of claim 7, wherein the at least one retaining member comprises two arcuate members disposed in opposite directions and transverse to the longer length of each ridge.

11. The medical probe of claim 7, wherein the at least one retaining member comprises a first set of retaining members and a second set of retaining members spaced apart along the ridges, the first set of retaining members comprising two arcuate members disposed in opposite directions and transverse to the longer length of each ridge and the second set of retaining members comprising two arcuate members disposed in opposite directions and transverse to the longer length of each ridge such that each electrode is captured between the first set of retaining members and the second set of retaining members.

12. The medical probe of claim 1, further comprising a plurality of electrically insulating sheaths, each disposed between a respective ridge of the plurality of ridges and a respective electrode, thereby electrically isolating the respective electrode from the respective ridge.

13. The medical probe according to claim 12,

wherein the sinusoidal member comprises an inner arc surrounding the second virtual circle such that the inner arc is positioned entirely less than the second distance from the longitudinal axis,

wherein the sinusoidal member comprises an outer portion surrounding the first virtual circle and surrounding the second virtual circle such that the outer portion is positioned entirely at a distance from the longitudinal axis greater than the second distance, and

wherein a majority of the outer portion of the sinusoidal member is covered by a respective one of the electrically insulating jackets.

14. The medical probe of claim 13, wherein a distal portion of each of the respective electrically insulative sheaths tapers outwardly and inwardly following a curvature of the outer portion of the sinusoidal member.

15. The medical probe of claim 13, a distal portion of each respective one of the electrically insulating sheaths abutting the distal portion of an adjacent insulating sheath.

16. The medical probe of claim 12, further comprising:

two electrodes coupled to respective ridges, the two electrodes for each of the plurality of ridges, the plurality of ridges including a first ridge and a second ridge, the first ridge having a single cross-section extending from a proximal portion of the first ridge to approximately a midpoint of the first ridge and thereafter dividing into at least two discrete cross-sections reaching the distal ridge portion of the first ridge, and the second ridge having at least two discrete cross-sections extending from a proximal portion of the second ridge to approximately a midpoint of the second ridge and thereafter combining into a single cross-section extending to the distal ridge portion of the second ridge.

17. The medical probe of claim 12, further comprising:

wires disposed within respective ones of the plurality of electrically insulating jackets,

wherein the wires are electrically connected to the respective electrodes.

18. The medical probe of claim 1, further comprising:

a flushing hub coupled to the tubular shaft, the flushing hub including a cylindrical member extending along a longitudinal axis, the cylindrical member including:

A proximal end having a first outer diameter and a recess extending inwardly along the longitudinal axis forming an inner portion;

a distal end having a second outer diameter that is smaller than the first outer diameter;

a flush inlet chamber disposed adjacent the interior portion and configured to receive fluid from a flush supply;

a plurality of irrigation openings disposed from a distal portion of the irrigation inlet chamber generally transverse to the longitudinal axis; and

a shunt extending into the distal portion of the irrigation inlet chamber to block fluid flow and redirect fluid flow out of the plurality of irrigation openings in a direction generally transverse to the longitudinal axis.

19. The medical probe of claim 1, wherein the plurality of ridges are configured to form an approximately spherical basket assembly when in an expanded form.

20. The medical probe of claim 1, further comprising:

a contact force sensor assembly disposed at the distal end of the tubular shaft and configured to detect a force applied to the medical probe, the contact force sensor assembly comprising:

A first bayonet mount portion comprising a component of the contact force sensor assembly;

a spine retention hub including a plurality of slots to receive respective spine members of the expandable basket assembly; and

a second bayonet mount portion configured to couple the ridge retention hub to the contact force sensor assembly by interlocking with the first bayonet mount portion.