CN116999148A

CN116999148A - Basket catheter with force sensor having bayonet mount

Info

Publication number: CN116999148A
Application number: CN202210979774.8A
Authority: CN
Inventors: C·T·比克勒; A·帕帕约阿努; J·T·凯斯
Original assignee: Biosense Webster Israel Ltd
Current assignee: Biosense Webster Israel Ltd
Priority date: 2022-04-28
Filing date: 2022-08-16
Publication date: 2023-11-07
Also published as: CN220588342U

Abstract

The disclosed technology includes a medical probe that includes a tubular shaft, a contact force sensor assembly, a ridge retention hub, and an expandable basket assembly. The contact force sensor may include a first bayonet mount portion and the ridge-retaining hub may include a second bayonet mount portion to couple the ridge-retaining hub to the contact force sensor by interlocking with the first bayonet mount portion. The expandable basket assembly may include a plurality of ridges and at least one electrode coupled to each of the plurality of ridges. Each ridge of the plurality of ridges may be configured to flex radially outward from the longitudinal axis when the expandable basket assembly transitions from the collapsed to the expanded form.

Description

Basket catheter with force sensor having bayonet mount

Technical Field

The present invention relates generally to medical devices, and in particular to catheters having 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 2021/0161592A1, 2021/0169550A1, 2021/0169567A1, 2021/0169568A1, 2021/0177503A1, 2021/0186604A1 and 2021/0196372A1, each of which is incorporated herein by reference and in the appendix hereof.

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 dimensions of the spine and electrode, adhering the electrode to the spine and then forming a ball basket from multiple linear ridges can be a difficult task, increasing manufacturing time and cost and increasing the chance of failure of the electrode 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 disclosed technology may include a medical probe having a tubular shaft, a contact force sensor assembly, a ridge retention hub, and an expandable basket assembly. The tubular shaft may include a proximal end and a distal end and extend along a longitudinal axis of the medical probe. The contact force sensor assembly may be 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 may include a first bayonet mount portion.

The ridge retention hub may be coupled to the contact force sensor assembly. The ridge-retaining hub may include a second bayonet mount portion that may be configured to couple the ridge-retaining hub to the contact force sensor assembly by interlocking with the first bayonet mount portion.

The expandable basket assembly may be coupled to the spine retention hub. The expandable basket assembly may include a plurality of ridges and at least one electrode coupled to each of the plurality of ridges. Each ridge of the plurality of ridges may extend along the longitudinal axis and be configured to flex radially outward from the longitudinal axis when the expandable basket assembly transitions from the collapsed to the expanded form.

The first bayonet mount may include a slot formed into the contact force sensor and the second bayonet mount may include a protrusion extending from the ridge retention hub. The slot may be configured to receive the protrusion. The slot and the protrusion may each be generally L-shaped. The slot may include a first slot portion that may extend generally longitudinally into the contact force sensor assembly from a distal end of the contact force sensor assembly and a second slot portion that may extend generally transversely from an end of the first slot portion. The projection may include a first projection portion extending generally longitudinally away from the ridge-retaining hub and a second projection portion extending generally transversely from an end of the first projection portion.

The first bayonet mount may include at least two slots formed into the contact force sensor and the second bayonet mount may include at least two protrusions extending from the ridge retention hub. The at least two slots may be configured to receive the at least two protrusions.

The first bayonet mount may include a protrusion extending from the contact force sensor assembly and the second bayonet mount may include a slot formed into the ridge retention hub. The slot may be configured to receive the protrusion. The slot may have a generally L-shaped recess and the protrusion may be a generally L-shaped member.

The protrusion may include a first protruding portion extending generally longitudinally from the contact force sensor assembly and a second protruding portion extending generally transversely from an end of the first protruding portion. The slot may be a first slot portion extending generally longitudinally from a proximal end of the ridge retention hub and a second slot portion extending generally transversely from an end of the first slot portion. The first bayonet mount may include at least two protrusions extending from the contact force sensor and the second bayonet mount may include at least two slots formed into the ridge retention hub. The at least two slots may be configured to receive the at least two protrusions.

The contact force sensor may include: a body having a generally cylindrical shape; a coil configured to generate a magnetic field; a sensor configured to detect the magnetic field generated by the coil; and a deflection portion configured to allow the body to deflect when a force is applied to the contact force sensor. The deflecting portion may comprise a coil spring. The coil spring may be formed into the body of the contact force sensor by forming a helical cutout in the body of the contact force sensor.

The coil may be disposed at a proximal end of the contact force sensor assembly and the sensor may be disposed at a distal end of the contact force sensor assembly.

The ridge retention hub may include a jet port configured to direct fluid to the at least one electrode.

Each of the plurality of ridges may include at least one retaining member extending generally transverse to the ridge. The at least one electrode may include a body defining a hollow portion extending through the body of the electrode. The body may be configured to receive each of the plurality of ridges. The electrode may be held by the at least one holding member. The at least one retaining member may comprise an arcuate member. In other examples, the at least one retaining member may include two arcuate members disposed in opposite directions and transverse to the longer length of each ridge.

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

The medical probe may include an electrically insulating sheath disposed between each of the plurality of ridges and the at least one electrode, thereby electrically isolating the at least one electrode from each of the plurality of ridges. The medical probe may include a wire disposed within the insulating sheath. The wire may be electrically connected to the at least one electrode.

Each of the plurality of ridges may comprise a material selected from the group consisting of nitinol, cobalt chromium, stainless steel, titanium, and combinations thereof. Each of the plurality of ridges may be configured to form an approximately spherical or oblate spherical basket assembly when in the expanded form.

The at least one electrode may comprise a material selected from the group consisting of stainless steel, cobalt chromium, gold, platinum, palladium, and alloys thereof. The at least one electrode may be configured to deliver an electrical pulse for irreversible electroporation. The pulse may include a peak voltage of at least 900 volts (V).

Additional features, functions, and applications of the disclosed technology are discussed in more detail herein.

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 in accordance with an example of the disclosed technology;

FIG. 2 is a perspective view of a medical probe in an expanded form according to an example of the disclosed technology;

FIG. 3A illustrates the medical probe of FIG. 2 with only the underlying ridge structure and one electrode disposed on the ridge, in accordance with an example of the disclosed technology;

FIG. 3B illustrates a ridge structure formed from a tube blank in accordance with an example of the disclosed technology;

FIG. 4 illustrates an exploded view of the medical probe of FIG. 2 in accordance with an example of the disclosed technology;

FIG. 5A illustrates a perspective view of a contact force sensor assembly and a ridge retention hub of a medical probe according to an example of the disclosed technology;

FIGS. 5B and 5C illustrate exploded views of a contact force sensor assembly and a ridge retention hub of a medical probe according to examples of the disclosed technology;

FIG. 6A illustrates a cross-sectional view of a contact force sensor assembly and a ridge retention hub of a medical probe according to an example of the disclosed technology;

FIG. 6B illustrates an exploded cross-sectional view of a spine retention hub of a medical probe and a contact force sensor assembly in accordance with an example of the disclosed technology; and is also provided with

Fig. 7A-7C illustrate cross-sectional and detail views of a ridge-retaining hub of a contact force sensor assembly and a medical probe to illustrate how the contact force sensor assembly and the ridge-retaining hub are coupled together, in accordance with examples of 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 examples 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 written description will clearly enable one skilled in the art to make and use the invention, and describes several examples, 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 components or elements to achieve the intended purpose thereof as described herein. More specifically, "about" or "approximately" may refer to a range of values of ±20% of the recited values, for example "about 90%" may refer to a range of values of 71% to 110%.

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

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

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

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

As discussed herein, the terms "biphasic pulse" and "monophasic pulse" refer to the corresponding electrical signals. A "biphasic pulse" refers to an electrical signal 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. Fluoroscopy may be used to visualize the ablation procedure in combination with such exemplary catheters.

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

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

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

Electroporation can be induced by applying a pulsed electric field across the biological cells to cause reversible (temporary) or irreversible (permanent) creation of pores in the cell membrane. Upon application of a pulsed electric field, the cell has a transmembrane electrostatic potential that rises above the static potential. Electroporation is reversible when the transmembrane electrostatic potential remains below the threshold potential, meaning that the pores can close when the applied pulsed electric field is removed and the cells can repair and survive themselves. If the transmembrane electrostatic potential rises above the threshold potential, electroporation is irreversible and the cell becomes permanently permeable. Thus, cells die 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 in the appendix hereof.

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 2021/0161592A1, 2021/0169550A1, 2021/0169567A1, 2021/0169568A1, 2021/0177503A1, 2021/0186604A1 and 2021/0196372A1, each of which is incorporated herein by reference in its entirety.

To deliver Pulsed Field Ablation (PFA) in an IRE (irreversible electroporation) procedure, the surface area of the electrode in contact with the tissue being ablated should be sufficiently large. As described below, the medical probe includes a tubular shaft having a proximal end and a distal end, and a basket assembly located at the distal end of the tubular shaft. The basket assembly includes a single unitary structure. The unitary structure may include a plurality of linear ridges formed from a sheet of flat material and one or more electrodes coupled to each of the ridges. The plurality of linear ridges may converge at a central ridge intersection comprising one or more cuts. The cutouts may allow each of the ridges to flex such that the ridges form an approximately spherical or oblate 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 not deployed (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 example of the 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 examples 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 method comprisesThe medical probe 22 may be used for other therapeutic and/or diagnostic purposes in the heart or other body organs, mutatis mutandis.

The medical probe 22 includes a flexible insertion tube 30 and a handle 32 coupled to the proximal end of the tubular shaft. During a medical procedure, a medical professional 34 may insert the probe 22 through the vascular system of the patient 28 such that the distal end 36 of the medical probe 22 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. 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 39 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 basket assembly 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. 2-4). The treatment catheter is translated through the introducer sheath such that basket assembly 38 is positioned within heart 26. The distal end 36 of the medical probe 22 corresponds to the distal end of the introducer sheath when the basket assembly 38 is received within the flexible insertion tube 30, and the distal end 36 (of the tube 30) corresponds to the proximal portion of the basket assembly 38 (fig. 2) when the basket assembly 38 extends from the distal end of the introducer sheath. Alternatively, the medical probe 22 may be configured to include a second handle on the treatment catheter and other features as would be understood by one of ordinary skill in the relevant art.

In the configuration shown in fig. 1, the console 24 is connected by a cable 42 to a body surface electrode that typically includes an adhesive skin patch 44 attached to the patient 28. The console 24 includes a processor 46 that, in conjunction with a tracking module 48, determines the position coordinates of the distal end 36 within the heart 26. The position coordinates may be determined based on electromagnetic position sensor output signals provided from the distal portion of the catheter when the generated magnetic field is present. Additionally or alternatively, the location coordinates may be based on impedance and/or current measured between the adhesive skin patch 44 and the electrode 40 attached to the basket assembly 38. In addition to 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 examples 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 the 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 examples, medical professional 34 may manipulate map 62 using one or more input devices 68. In alternative examples, 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. 2 is an illustration showing a prototype 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 80 at the distal end 36 of the insertion tube 30. The probe 22 may include a contact force sensor assembly 400 to determine the contact force of the ridges against the heart tissue. It should be noted that the medical probe 22 shown in fig. 2 lacks the introducer sheath shown in fig. 1. In the expanded form of fig. 2, the ridges 214 curve radially outwardly, while in the collapsed form, not shown, the ridges are generally disposed along the longitudinal axis 86 of the insertion tube 30. For simplicity, only a single ridge 214 is labeled with a reference numeral, but those skilled in the art will appreciate that basket assembly 38 may include one or more ridges 214, as shown in fig. 2. Similarly, only the electrodes 40 and the insulating sleeve 217 on a single ridge 214 are labeled with reference numerals, but those skilled in the art will appreciate that the basket assembly 38 may include one or more electrodes 40 and one or more insulating sleeves, depending on the particular configuration. A plurality of electrically insulating sleeves 217 may be provided such that each sheath may be disposed between a respective one of the plurality of ridges 214 and a respective one of the plurality of electrodes 40, thereby electrically isolating the plurality of electrodes 40 from the plurality of ridges 214.

As shown in fig. 2, basket assembly 38 includes a plurality of flexible ridges 214 formed at and connected at the ends of tubular shaft 84. During a medical procedure, the medical professional 34 may deploy the basket assembly 38 by extending the tubular shaft 84 from the insertion tube 30, causing the basket assembly 38 to exit the insertion tube 30 and transition to the expanded form. The ridges 214 may have an oval (e.g., circular) or rectangular cross-section, 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. 2 and 3, basket assembly 38 has a proximal portion with 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 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 may comprise a single unitary structure comprising a plurality of ridges 214 formed from a cylindrical tube blank (as shown in fig. 3B) and treated to cause the ridges 214 to be biased radially outwardly. The material for the ridges may be selected from the group consisting of nitinol, cobalt chromium, stainless steel, titanium, and combinations thereof.

Fig. 4 illustrates an exploded view of the medical probe of fig. 2 in accordance with an example of the disclosed technology. As shown in fig. 4, a ridge retention hub 90 may be inserted into the tubular shaft 84 and attached to a contact force sensor assembly 400. 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. The relief slot 96 is provided with an undercut 96a (fig. 5A) extending along the longitudinal axis to allow insertion of a ridge attachment end 216 (which may have a hole, as shown in fig. 3A). The relief slot 96 may be provided with a tab 96b (fig. 5C) that engages with a complementary recess 218 on the ridge retaining end 216 (fig. 3A) to prevent any 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, as described in more detail herein. 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 electrode 40 may be generally positioned in place relative to the spine 214 by a retaining member 220 integrally formed with the spine 214. In fig. 3A, it can be seen that each of the ridges 214 can 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 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 once released. In one example, the at least one retaining member 220 is shaped in an arcuate configuration with a center of such an arcuate extending away from the periphery of the ridge 214. In a preferred embodiment, the at least one retaining member 220 of each electrode 40 may comprise two arcuate members 220 disposed in opposite directions and oriented 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 38 formed from a tube blank. Also within the scope of the present invention, basket assembly 38 is formed from flat sheet stock, cut, and heat treated to achieve the spherical basket shape shown herein.

Fig. 4 illustrates an exploded view of the medical probe 22 of fig. 2 in accordance with an example of the disclosed technology. Moving from top to bottom in fig. 4, the assembly of the medical probe 22 will now be briefly described. As shown in fig. 4, and as previously described, 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 to help secure the ridge 214 in place. As will be described in greater detail herein, the contact force sensor assembly 400 may be coupled to the spine retention hub 90. The medical probe 22 may also include a contact force sensor assembly 400, which may be disposed in a contact force sensor assembly sleeve 95. The contact force sensor assembly sleeve 95 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.

Turning now to fig. 5A-6B, the contact force sensor assembly 400 and the ridge retention hub 90 of the medical probe 22 will now be further described. Examples of contact force sensor assemblies are disclosed in U.S. patent 8,357,152 and 10,688,278 and U.S. patent publication 2021/0187254A1, each of which is incorporated by reference herein and in the appendix hereof. Fig. 5A shows a perspective view of the contact force sensor assembly 400 and the ridge-retaining hub 90 of the medical probe 22 coupled together, while fig. 5B and 5C show exploded views of the contact force sensor assembly 400 and the ridge-retaining hub 90. Further, fig. 6A and 6B show cross-sectional views of the contact force sensor assembly 400 and the ridge retention hub 90.

As shown, the contact force sensor assembly 400 may include a proximal end 402 and a distal end 403. The proximal end 402 may house a magnetic field generator coil 410 and the distal end 403 may house a magnetic field sensor 412. It is to be appreciated that the magnetic field generator coil 410 may be configured to generate a magnetic field, while the magnetic field sensor 412 may be configured to detect the presence and magnitude of the magnetic field.

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, as shown in fig. 5A-6B. 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 and proximal with respect to the basket assembly 38 and as close as possible to the basket assembly 38 such that contact with heart tissue by the ridges 214 may be transferred to the contact force sensor assembly 400.

It will be appreciated that the magnetic field sensor 412 may detect a change in the magnitude of the magnetic field force generated by the magnetic field generator coil 410 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 deflection portion 404 may be predetermined and the distance between magnetic field generator coil 410 and magnetic field sensor 412 may be detected, the force applied to medical probe 22 may be determined (e.g., by using hooke's law, or formula 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.

As shown in fig. 5A-6B, the contact force sensor assembly 400 can include a female connector 406, while 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.

When the male connector 408 is inserted into the female connector 406, the "L" shapes of the female connector 406 and the male connector 408 may interlock, thus causing the contact force sensor assembly 400 to be coupled to the ridge retention hub 90. In some examples, when female connector 406 and the "L" portion of male connector 408 are aligned, male connector 408 may be caused to spring forward into female connector 406. In this manner, the male connector 408 must be pushed to remove the male connector 408 from the female connector 406 (rather than merely torsionally contacting the force sensor assembly 400 and/or the spring retention hub 90).

Turning now to fig. 7A-7C, the contact force sensor assembly 400 may be coupled to the spine retention hub 90 by: aligning the female connector 406 with the male connector 408 (as shown in fig. 7A); inserting the male connector 408 into the female connector 406 (as shown in fig. 7B); the torsion contact force sensor assembly 400 and/or the ridge retention hub 90 then causes the female connector 406 and the male connector 408 to interlock. In this manner, the contact force sensor assembly 400 may be coupled to the spine retention hub 90 and prevent the contact force sensor assembly 400 from being dislodged from the spine retention hub 90 as the medical probe 22 is pulled through the flexible insertion tube 30.

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:

a tubular shaft including a proximal end and a distal end, the tubular shaft extending along a longitudinal axis of the medical probe;

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 having a first bayonet mount portion;

a spine retention hub including a plurality of slots to receive respective spine members, the spine retention hub coupled to the contact force sensor assembly, the spine retention hub having a second bayonet mount portion configured to couple the spine retention hub to the contact force sensor assembly by interlocking with the first bayonet mount portion; and

an expandable basket assembly coupled to the spine retention hub, the expandable basket assembly including a plurality of spines disposed in a respective plurality of slots of the spine retention hub and at least one electrode coupled to each spine of the plurality of spines, the plurality of spines extending along the longitudinal axis and configured to flex radially outward from the longitudinal axis when the expandable basket assembly transitions from a collapsed to an expanded form.

2. The medical probe of claim 1, wherein the first bayonet mount includes a slot formed into the contact force sensor, and

wherein the second bayonet mount comprises a protrusion extending from the ridge retention hub, the slot configured to receive the protrusion.

3. The medical probe of claim 2, wherein the slot comprises a generally L-shaped recess, and

wherein the protrusion comprises a generally L-shaped member.

4. The medical probe of claim 2 or 3, wherein the slot includes a first slot portion extending generally longitudinally into the contact force sensor assembly from a distal end of the contact force sensor assembly and a second slot portion extending generally transversely from an end of the first slot portion; and is also provided with

Wherein the projection includes a first projection portion extending generally longitudinally away from the ridge retention hub and a second projection portion extending generally transversely from an end of the first projection portion.

5. The medical probe of any of claims 2-4, wherein the first bayonet mount includes at least two slots formed into the contact force sensor, and

Wherein the second bayonet mount comprises at least two protrusions extending from the ridge-retaining hub, the at least two slots configured to receive the at least two protrusions.

6. The medical probe of claim 1, wherein the first bayonet mount comprises a protrusion extending from the contact force sensor assembly, and

wherein the second bayonet mount comprises a slot formed into the ridge retention hub, the slot configured to receive the protrusion.

7. The medical probe of claim 6, wherein the slot comprises a generally L-shaped recess, and

wherein the protrusion comprises a generally L-shaped member.

8. The medical probe of claim 6 or 7, wherein the protrusion comprises a first protrusion portion extending generally longitudinally from the contact force sensor assembly and a second protrusion portion extending generally transversely from an end of the first protrusion portion; and is also provided with

Wherein the slot includes a first slot portion extending generally longitudinally from a proximal end of the ridge retention hub and a second slot portion extending generally transversely from an end of the first slot portion.

9. The medical probe of any of claims 6 to 8, wherein the first bayonet mount comprises at least two protrusions extending from the contact force sensor, and

Wherein the second bayonet mount comprises at least two slots formed into the ridge-retaining hub, the at least two slots configured to receive the at least two protrusions.

10. The medical probe of any one of claims 1 to 9, wherein the contact force sensor assembly comprises:

a body having a generally cylindrical shape;

a coil configured to generate a magnetic field;

a sensor configured to detect the magnetic field generated by the coil; and

a deflection portion configured to allow deflection of the body when a force is applied to the contact force sensor assembly.

11. The medical probe of claim 10, wherein the deflection portion comprises a coil spring.

12. The medical probe of claim 11, wherein the coil spring is formed in the body of the contact force sensor by forming a helical cut in the body of the contact force sensor.

13. The medical probe of any one of claims 10 to 12, wherein the coil is disposed at a proximal end of the contact force sensor assembly and the sensor is disposed at a distal end of the contact force sensor assembly.

14. The medical probe of any one of claims 1 to 13, wherein the ridge-retaining hub includes a jet port configured to direct fluid to the at least one electrode.

15. The medical probe of any one of claims 1 to 14, wherein each of the plurality of ridges includes at least one retaining member extending generally transverse to the ridge.

16. The medical probe of claim 15, wherein the at least one electrode includes a body defining a hollow portion extending through the body of the electrode, the body configured to receive each of the plurality of ridges, the electrode being retained by the at least one retaining member.

17. The medical probe of claim 15 or 16, wherein the at least one retaining member comprises an arcuate member.

18. The medical probe of any of claims 15 to 17, wherein the at least one retaining member comprises two arcuate members disposed in opposite directions and transverse to the longer length of each ridge.

19. The medical probe of any of claims 15 to 18, wherein the at least one electrode comprises a first electrode and a second electrode; and is also provided with

Wherein the at least one retaining member comprises a first set of retaining members and a second set of retaining members spaced apart along each of the plurality of 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 the first electrode is captured between the first set of retaining members and the second electrode is captured between the second set of retaining members.

20. The medical probe of any one of claims 1 to 19, further comprising an electrically insulating sheath disposed between each of the plurality of ridges and the at least one electrode, thereby electrically isolating the at least one electrode from each of the plurality of ridges.

21. The medical probe of claim 20, further comprising a wire disposed within the insulating sheath.

22. The medical probe of claim 21, wherein the wire is electrically connected to the at least one electrode.

23. The medical probe of any of claims 1-22, wherein each ridge of the plurality of ridges comprises a material selected from the group consisting of nitinol, cobalt chromium, stainless steel, titanium, and combinations thereof.

24. The medical probe according to any one of claims 1 to 23, wherein at least one electrode comprises a material selected from stainless steel, cobalt chromium, gold, platinum, palladium, and alloys thereof.

25. The medical probe of any one of claims 1 to 24, wherein the at least one electrode is configured to deliver an electrical pulse for irreversible electroporation, the pulse comprising a peak voltage of at least 900 volts (V).

26. The medical probe of any of claims 1 to 25, wherein each ridge of the plurality of ridges is configured to form an approximately spherical basket assembly when in the expanded form.

27. The medical probe of any of claims 1 to 26, wherein each ridge of the plurality of ridges is configured to form an approximately oblate basket assembly when in the expanded form.