Electrode with retention mechanism for use with a medical probe

Abstract

To provide an electrode for a medical probe.SOLUTION: The disclosed subject matter includes an electrode comprising a body extending along a longitudinal axis from a proximal end to a distal end. The body defines a tissue-facing surface, a lumen extending along a longitudinal axis through the body from a proximal end to a distal end, and one or more recesses extending through the body transverse to the longitudinal axis of the body. The one or more recesses are disposed between the tissue-facing surface and the lumen and define a first portion extending into the body at a first depth and a second portion extending from the first portion into the body at a second depth. The first portion includes a first gap distance and the second portion includes a second gap distance. The second gap distance can be greater than the first gap distance.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates generally to medical devices, and more particularly to medical probes having electrodes, and further, but not exclusively, to medical probes suitable for mapping and ablation of cardiac tissue. [Background technology]

[0002] Cardiac arrhythmias, such as atrial fibrillation (AF), occur when an area of ​​cardiac tissue abnormally conducts electrical signals to adjacent tissue. This disrupts the normal cardiac cycle and causes asynchronous rhythms. Certain procedures exist to treat arrhythmias, including surgically destroying the source of the signals that cause the arrhythmia and disrupting the conduction pathways of such signals. By selectively ablating cardiac tissue with the application of energy via a catheter, it is sometimes possible to stop or redirect the propagation of unwanted electrical signals from one part of the heart to another.

[0003] Regions of cardiac tissue can be mapped by a medical probe to identify abnormal electrical signals. Ablation can be performed using the same or a different medical probe. Some exemplary probes include multiple spines with electrodes positioned thereon. The electrodes are generally attached to the spines, which are configured to bend radially outward when deployed from a sheath. The electrodes are then brought into contact with tissue for tissue mapping or ablation. Summary of the Invention [Problem to be solved by the invention]

[0004] Some exemplary catheters include multiple spines with electrodes disposed thereon. The electrodes are typically attached to the spines and secured in place by soldering, welding, or using adhesives. However, due to the small size of the electrodes, soldering or welding the electrodes to the spines can be difficult. Furthermore, adhesives generally do not adhere to metallic materials as well as solder or welding materials. If the adhesive does not sufficiently adhere to the electrode or if the adhesive delaminates from the electrode, the electrode may become loose on the spine and slide out of place along the spine. However, attaching the electrodes to the spines using adhesives is often an easier and more cost-effective process. Therefore, what is needed is a system and method for attaching electrodes to the spines of a basket assembly using an adhesive that ensures sufficient bonding to the electrode and spine. These and other problems can be addressed by the technology disclosed herein. [Means for solving the problem]

[0005] According to the disclosed technology, an electrode for a medical probe is provided. The electrode includes a body extending from a proximal end to a distal end along a longitudinal axis. The body defines a tissue-facing surface, a lumen extending through the body along the longitudinal axis from the proximal end to the distal end, and one or more recesses extending through the body transversely to the longitudinal axis of the body. The one or more recesses are disposed between the tissue-facing surface and the lumen and define a first portion extending into the body at a first depth and a second portion extending from the first portion into the body at a second depth. The first portion includes a first gap distance, and the second portion includes a second gap distance. The second gap distance can be greater than the first gap distance.

[0006] The disclosed technology further includes a medical probe including a tubular shaft having a proximal end and a distal end, the tubular shaft extending along a longitudinal axis of the tubular shaft. The medical probe further includes an expandable basket assembly coupled to the distal end of the tubular shaft. The expandable basket assembly can include a plurality of spines coupled to the tubular shaft and configured to bend radially outward from the longitudinal axis of the tubular shaft, and a plurality of electrodes disposed on the plurality of spines. Each electrode of the plurality of electrodes can include a body extending along the longitudinal axis of the body from its proximal end to its distal end. The body can define a tissue-facing surface, an internal lumen extending through the body from the proximal end to the distal end, and one or more recesses disposed transverse to the longitudinal axis of the body between the tissue-facing surface and the internal lumen. The one or more recesses can define a first portion extending a first depth into the body and a second portion extending a second depth from the first portion into the body. The first portion can include a first gap distance and the second portion can include a second gap distance. The second gap distance can be greater than the first gap distance.

[0007] The disclosed technology further includes a method of manufacturing an electrode for a medical probe. The method may include forming a lumen through a body of the electrode, the lumen extending from a proximal end to a distal end along a longitudinal axis, and forming one or more recesses extending along the body transverse to the longitudinal axis. The one or more recesses may define a first portion extending to a first depth within the body and a second portion extending from the first portion to a second depth within the body. The first portion may include a first gap distance, and the second portion may include a second gap distance. The second gap distance may be greater than the first gap distance. [Brief explanation of the drawings]

[0008] The present disclosure will be more fully understood from the following detailed description of the embodiments thereof, when read in conjunction with the drawings. [Figure 1]1 is a schematic, pictorial illustration of a medical system including a medical probe having a distal end with electrodes, in accordance with the techniques of the present disclosure; [Figure 2] 1 is a schematic, pictorial illustration of a basket catheter with electrodes in accordance with the techniques of the present disclosure. [Figure 3] FIG. 1 is a perspective view of an electrode in accordance with the techniques of the present disclosure. [Figure 4A] FIG. 1 is a side view of an electrode in accordance with the techniques of the present disclosure. [Figure 4B] FIG. 4B is a detailed view of the electrode of FIG. 4A in accordance with the techniques of the present disclosure. [Figure 5] FIG. 1 is an end view of an electrode in accordance with the techniques of the present disclosure. [Figure 6] FIG. 6 is a cross-sectional view of the electrode of FIG. 5 taken along line AA in accordance with the techniques of the present disclosure. [Figure 7] 1 is a flowchart of a method for manufacturing a medical probe in accordance with the techniques of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] The electrodes described herein provide a solution for ensuring that electrodes are adequately secured in place on a spine when an adhesive is used to secure the electrode in place. The electrode includes a recess in the body of the electrode, which is formed to receive the adhesive but prevent the adhesive from being removed from the recess once the adhesive has hardened. The recess may include, for example, a first portion extending into the body of the electrode and a second portion extending from the first portion and having a gap distance greater than that of the first portion. In this way, the adhesive can enter the recess when in liquid form but is prevented from being removed from the recess when in hardened solid form, thereby securing the electrode in place on the spine.

[0010] The following detailed description should be read with reference to the drawings, in which like elements in different drawings are numbered the same. 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, but not by way of limitation, the principles of the invention. This description will clearly enable any person skilled in the art to make and use the invention and sets forth several embodiments, adaptations, variations, alternatives, and uses of the invention, including what is currently contemplated to be the best mode for carrying out the invention.

[0011] As used herein, the term "approximately" or "about" in connection with any numerical value or range indicates a suitable dimensional tolerance that enables a portion or collection of components to function for the intended purpose described herein. More specifically, "about" or "nearly" can refer to a range of values ​​of ±20% of the recited value, while, for example, "about 90%" can refer to a range of values ​​of 70% to 110%.

[0012] Additionally, as used herein, the terms "patient," "host," "user," and "subject" refer to any human or animal subject, and while use of the invention in human patients represents a preferred embodiment, it is not intended to limit the systems or methods to human use. Similarly, the term "proximal" refers to a location closer to the operator or physician, and "distal" refers to a location further from the operator or physician.

[0013] As discussed herein, the vascular system of a "patient," "host," "user," and "subject" may be that of a human or any animal. It should be understood that the animal may be of any of a variety of applicable types, including, but not limited to, mammals, veterinary animals, livestock animals, or companion animals. As an 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 understood that the subject may be, for example, any applicable human patient.

[0014] As discussed herein, a "physician" may include a doctor, surgeon, technician, scientist, operator, or any other individual or delivery equipment involved in delivering a multi-electrode catheter for the treatment of drug-refractory atrial fibrillation to a subject.

[0015] As discussed herein, the term "ablate" or "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 irregular cardiac signals within cells by utilizing non-thermal energy, such as irreversible electroporation (IRE), which is interchangeably referred to as pulsed electric field (PEF) and pulsed field ablation (PFA) throughout this disclosure. When referring to the devices and corresponding systems of the present disclosure, ablation or ablation is used throughout this disclosure to refer to non-thermal ablation of cardiac tissue for specific conditions, including, but not limited to, arrhythmias, atrial flutter ablation, pulmonary vein isolation, supraventricular tachycardia ablation, and ventricular tachycardia ablation. The term "ablate" or "ablation" also includes known methods, devices, and systems for achieving various forms of body tissue ablation, as will be understood by those skilled in the art.

[0016] The medical probes described herein may include electrodes configured to map electrophysiological signals propagating through tissue and / or deliver ablative energy to tissue. For example, the electrodes may be configured to deliver ablative energy to tissue using techniques such as bipolar or monopolar ablation using biphasic or monophasic signals, as well as thermal ablation techniques. As discussed herein, the terms "bipolar" and "monopolar," when used to refer to ablation schemes, describe different ablation schemes with respect to current paths and electric field distributions. "Bipolar" refers to an ablation scheme that utilizes a current path between two electrodes, both positioned at the treatment site. The current density and electric flux density are typically approximately equal at each of the two electrodes. "Monopolar" refers to an ablation scheme that utilizes a current path between two electrodes, where one electrode with a high current density and high electric flux density is positioned at the treatment site and a second electrode with a relatively low current density and lower electric flux density is positioned remotely from the treatment site.

[0017] As discussed herein, the terms "biphasic pulse" and "monophasic pulse" refer to the respective electrical signals. A "biphasic pulse" refers to an electrical signal having 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"). A "monophasic pulse" refers to an electrical signal having only a positive phase or only a negative phase. Preferably, a system providing a biphasic pulse is configured to prevent the application of direct current (DC) to the patient. For example, the average voltage of a 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. When voltage amplitudes of biphasic and / or monophasic pulses are described herein, it is understood that the expressed voltage amplitude is the absolute value of the approximate peak amplitude of each of the positive and / or negative voltage phases. Each phase of a biphasic and monophasic pulse preferably has a square shape with an essentially constant voltage amplitude during the majority of the phase duration. The phases of the biphasic pulse are separated in time by an interphase delay. The interphase delay duration is preferably less than or approximately equal to the duration of a phase of the biphasic pulse. The interphase delay duration is more preferably about 25% of the duration of a phase of the biphasic pulse.

[0018] As discussed herein, the terms "tubular" and "tube" are intended to be broadly interpreted and are not limited to right cylindrical structures, or structures that are strictly circular in cross section, or structures that are uniform in cross section throughout their length. For example, a tubular structure is generally illustrated as a substantially right cylindrical structure. However, a tubular structure may have a tapered or curved outer surface without departing from the scope of the present disclosure.

[0019] The present disclosure relates to systems, methods, or uses, and devices that can be used for IRE ablation of cardiac tissue to treat cardiac arrhythmias. Ablation energy is typically delivered to cardiac tissue by electrodes in the end effector of a catheter that can deliver the ablation energy along the tissue to be ablated. Some exemplary catheters include a three-dimensional structure at their tip portion and are configured to administer the ablation energy from various electrodes positioned on the three-dimensional structure. Ablation procedures incorporating such exemplary catheters can be visualized using X-ray fluoroscopy.

[0020] Ablation of cardiac tissue using radiofrequency (RF) energy and thermal techniques, such as cryoablation, to improve cardiac function is a well-known procedure. Successful ablation using thermal techniques typically requires measuring cardiac potentials at various locations in the myocardium. Additionally, temperature measurements during ablation provide data that enables assessment of ablation effectiveness. Typically, ablation procedures using thermal techniques involve measuring electrode potentials and temperatures before, during, and after the actual ablation. RF approaches can pose risks that can lead to tissue charring, burning, steam popping, phrenic nerve paralysis, pulmonary vein stenosis, and esophageal fistulas. Cryoablation is an alternative approach to RF ablation that can reduce some of the thermal risks associated with RF ablation. However, operating a cryoablation device and selectively applying cryoablation are generally more difficult than RF ablation. Therefore, cryoablation is not feasible in certain anatomical shapes that can be reached by electrical ablation devices.

[0021] The present disclosure may include electrodes configured for RF ablation, cryoablation, and / or irreversible electroporation (IRE). IRE may be referred to interchangeably throughout this disclosure as pulsed electric field (PEF) ablation and pulsed field ablation (PFA). IRE, as discussed in this disclosure, is a non-thermal cell death technique that can be used to ablate atrial arrhythmias. To ablate using IRE / PEF, biphasic voltage pulses are applied to destroy myocardial cellular structures. The biphasic pulses are non-sinusoidal waveforms that can be tailored 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 in the treatment area, indiscriminately heating all cells within the treatment area. Therefore, IRE has the ability to spare adjacent heat-sensitive structures or tissues, which may be beneficial in reducing potential complications known with ablation or isolation modalities. Additionally or alternatively, monophasic pulses may be utilized.

[0022] Electroporation can be induced by applying a pulsed electric field to biological cells to cause the reversible (temporary) or irreversible (permanent) creation of pores in the cell membrane. Cells have a transmembrane electrostatic potential that increases above their resting potential upon application of the pulsed electric field. While the transmembrane electrostatic potential remains below a threshold potential, electroporation is reversible, meaning that the pores can close when the applied pulsed electric field is removed, allowing the cell to self-repair and survive. If the transmembrane electrostatic potential increases above the threshold potential, electroporation is irreversible and the cell becomes permanently permeable. As a result, the cell dies due to loss of homeostasis, typically by apoptosis. Generally, different types of cells have different threshold potentials. For example, cardiac cells have a threshold potential of approximately 500 V / cm, while bone has a threshold potential of 3000 V / cm. These differences in threshold potential allow IRE to selectively target tissues based on their threshold potential.

[0023] The solutions of the present disclosure include systems and methods for applying electrical signals from catheter electrodes positioned near myocardial tissue to generate ablation energy for ablating the myocardial tissue. In some examples, the systems and methods may be effective for ablating target tissue by inducing irreversible electroporation. In some examples, the systems and methods may be effective for inducing reversible electroporation as part of a diagnostic procedure. Reversible electroporation occurs when electricity applied at the electrodes falls below the electric field threshold of the target tissue, allowing cells to repair. Reversible electroporation does not kill cells but allows a physician to see the effect of reversible electroporation on the electrical activation signal near the target location. Exemplary systems and methods for reversible electroporation are disclosed in U.S. Patent Application Publication No. 2021 / 0162210, which is incorporated herein by reference in its entirety.

[0024] The pulsed electric field and its effectiveness in inducing reversible and / or irreversible electroporation can be affected by the physical parameters of the system and the biphasic pulse parameters of the electrical signal. Physical parameters can include electrode contact area, electrode spacing, electrode shape, etc. Examples presented herein generally include physical parameters adapted to effectively induce reversible and / or irreversible electroporation. Biphasic pulse parameters of the electrical signal can include voltage amplitude, pulse duration, interpulse delay, interpulse delay, total application time, delivered energy, etc. In some examples, the parameters of the electrical signal can be adjusted to induce both reversible and irreversible electroporation given the same physical parameters. Examples of various systems and methods for ablation, including IRE, are provided in U.S. Patent Application Publication Nos. 2021 / 0169550(A1), 2021 / 0169567(A1), 2021 / 0169568(A1), 2021 / 0161592(A1), 2021 / 0196372(A1), 2021 / 0177503(A1), and 2021 / 0186604(A1), the entire contents of each of which are incorporated herein by reference.

[0025] Reference is made to FIG. 1 , which illustrates an exemplary catheter-based electrophysiology mapping and ablation system 10. The system 10 includes multiple catheters that are percutaneously inserted by a physician 24 through the vascular system of a patient 23 and into a chamber or vasculature of a heart 12. Typically, a delivery sheath catheter is inserted into the left or right atrium near a desired location in the heart 12. Multiple catheters may then be inserted into the delivery sheath catheter to reach the desired location. The multiple catheters may include catheters dedicated to sensing intracardiac electrogram (IEGM) signals, catheters dedicated to ablation, and / or catheters dedicated to both sensing and ablation. An exemplary catheter 14 configured for sensing and ablation is illustrated herein. The physician 24 brings a distal tip 28 of the catheter 14 (which may be referred to herein as a basket catheter, basket assembly, expandable basket assembly, and / or end effector) into contact with the heart wall to sense a target site in the heart 12.

[0026] Catheter 14 is an exemplary catheter that includes one, and preferably multiple, electrodes 100, optionally distributed across multiple spines 22 at distal tip 28, and configured to sense IEGM signals and / or deliver ablation energy to tissue. Catheter 14 may additionally include a position sensor 29 embedded in or near distal tip 28 for tracking the position and orientation of distal tip 28. Optionally and preferably, position sensor 29 is a magnetic-based position sensor that includes three magnetic coils for sensing three-dimensional (3D) position and orientation.

[0027] The magnetic-based position sensor 29 may operate in conjunction with a location pad 25 that includes a plurality of magnetic coils 32 configured to generate a magnetic field within a predetermined working volume. The real-time position of the distal tip 28 of the catheter 14 may be tracked based on the magnetic fields generated using the location pad 25 and sensed by the magnetic-based position sensor 29. Details of magnetic-based position sensing technology are described in U.S. Patent Nos. 5,391,199, 5,443,489, 5,558,091, 6,172,499, 6,239,724, 6,332,089, 6,484,118, 6,618,612, 6,690,963, 6,788,967, and 6,892,091, each of which is incorporated herein by reference in its entirety.

[0028] The system 10 includes one or more electrode patches 38 positioned for skin contact on the patient 23 to establish a position reference for the location pads 25 and impedance-based tracking of the electrodes 100. For impedance-based tracking, current is directed to the electrodes 100 and sensed at the electrode skin patches 38, allowing the location of each electrode to be triangulated via the electrode patches 38. Details of impedance-based position tracking techniques are described in U.S. Patent Nos. 7,536,218, 7,756,576, 7,848,787, 7,869,865, and 8,456,182, each of which is incorporated by reference herein in its entirety.

[0029] Recorder 11 displays electrograms 21 captured by body surface ECG electrodes 18 and intracardiac electrograms (IEGMs) captured by electrodes 100 on catheter 14. Recorder 11 may include pacing capability for pacing the cardiac rhythm and / or may be electrically connected to a stand-alone pacer.

[0030] System 10 may include an ablation energy generator 50 adapted to deliver ablation energy to one or more electrodes at the distal tip of a catheter configured for ablation. The energy generated by ablation energy generator 50 may include, but is not limited to, radiofrequency (RF) energy, or pulsed-field ablation (PFA) energy, including unipolar or bipolar high-voltage DC pulses, such as may be used to perform irreversible electroporation (IRE), or a combination thereof.

[0031] The patient interface unit (PIU) 30 is an interface configured to establish electrical communication between the catheters, the electrophysiology equipment, a power source, and a workstation 55 that controls the operation of the system 10. The electrophysiology equipment of the system 10 may include, for example, multiple catheters, location pads 25, body surface ECG electrodes 18, electrode patches 38, an ablation energy generator 50, and a recorder 11. Optionally and preferably, the PIU 30 additionally includes processing capabilities for implementing real-time calculations of catheter position and performing ECG calculations.

[0032] The workstation 55 includes a processor unit having memory, memory or storage loaded with appropriate operating software, and user interface functionality. The workstation 55 may optionally provide multiple functions, including: (1) modeling the endocardial anatomical structure in three dimensions (3D) and rendering the model or anatomical map 20 for display on the display device 27; (2) displaying activation sequences (or other data) compiled from recorded electrograms 21 in a representative visual representation or image superimposed on the rendered anatomical map 20 on the display device 27; (3) displaying the real-time position and orientation of multiple catheters within the cardiac chambers; and (4) displaying areas of interest, such as where ablation energy is being applied, on the display device 27. One commercially available product embodying elements of the system 10 is available as the CARTO™ 3 system, commercially available from Biosense Webster, Inc., 31 Technology Drive, Suite 200, Irvine, CA 92618, USA.

[0033] 2 is a schematic drawing illustrating a perspective view of a basket catheter 28 with spines 22 and electrodes 100 in an expanded configuration, such as by being advanced from a sheath (not shown). As shown in FIG. 2, the basket catheter 28 can include a plurality of spines 22 that can bend radially outward from the longitudinal axis 86 when in the expanded configuration. The spines 22 can be formed from a biocompatible elastic material, such as nitinol, such that the spines 22 are naturally biased to expand outward into the expanded configuration.

[0034] Each spine 22 can include one or more electrodes 100 attached thereto. The electrodes 100 can be configured such that the electrodes 100 can be disposed on the spines 22 in alignment with adjacent spines 22 or such that the electrodes 100 on adjacent spines 22 are not aligned with each other. The electrodes 100 can be configured such that when retracted into the sheath, the electrodes can be folded together in a tight configuration. The electrodes 100 described herein can be configured for mapping electrophysiological signals through tissue and / or ablation of tissue.

[0035] The spine 22 may have an oval (e.g., circular) or rectangular (which may appear flat) cross-section and may include a flexible, elastic material (e.g., a shape memory alloy such as nickel-titanium, also known as nitinol, or other materials such as cobalt chromium, stainless steel, titanium, or even polymeric materials) forming the spine 22. Similarly, the techniques of the present disclosure may be applicable to a basket catheter 28 formed from a single spine 22 or multiple spines 22, each attached to both ends.

[0036] The spine 22 can be formed from a single sheet of planar material. In some embodiments, the spine 22 can be formed from a single sheet of planar material such that the spine 22 converges toward a central intersection. In other embodiments, the spine 22 can be formed separately and then attached at both ends as shown and just described.

[0037] As will be appreciated, the spine 22 may be electrically insulated from the electrode 100 to prevent arcing from the electrode 100 to the spine 22. For example, an insulating jacket (not shown) may be disposed between the spine 22 and the electrode 100, although one skilled in the art will appreciate that other insulating coatings are contemplated. For example, an insulating coating may be applied to the spine 22, the electrode 100, or both. The insulating jacket may be made from a biocompatible, electrically insulating material such as polyamide-polyether (Pebax) copolymer, polyethylene terephthalate (PET), urethane, polyimide, parylene, silicone, or the like. In some examples, the insulating material may comprise a biocompatible polymer, including, but not limited to, polyetheretherketone (PEEK), polyglycolic acid (PGA), poly(lactic-co-glycolic acid) copolymer (PLGA), polycaprolactone (PCL), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly-L-lactide, polydioxanone, polycarbonate, and polyanhydride, with the ratio of specific polymers selected to control the degree of inflammatory response. The insulating jacket may also include one or more additives or fillers, such as, for example, polytetrafluoroethylene (PTFE), boron nitride, silicon nitride, silicon carbide, aluminum oxide, aluminum nitride, or zinc oxide.

[0038] 3 is a perspective view of an electrode 100 in accordance with the technology of the present disclosure. The electrode 100 may include a body 102 extending from a proximal end 106 to a distal end 106 along a longitudinal axis 104. The electrode 100 may be formed in a variety of shapes, sizes, and configurations depending on the particular application. As shown, the electrode 100 may define a lumen 110 extending through the body 102 along the longitudinal axis 104. The lumen 110 may be configured to receive the spine 22 of the basket catheter 28 such that the electrode 100 may slide along and be secured to the spine 22.

[0039] The electrode 100 may include an inward-facing surface 112 and a tissue-facing surface 114. For example, the electrode 100 may be configured such that, when the electrode 100 is attached to the spine 22, the inward-facing surface 112 may be the surface of the electrode 100 that faces inward into a central portion of the basket assembly 28, and the tissue-facing surface 114 may be the surface of the electrode 100 that faces outward from the basket assembly 28. As a result, the tissue-facing surface 114 is configured to contact tissue when deployed within the patient 23. To help ensure that the basket assembly 28 is atraumatic, the electrode 100 may include rounded edges 116 (atraumatic edges) on at least the surfaces likely to contact tissue. The rounded edges 116 may be formed by, for example, tumbling, sanding, filing, deburring, sandblasting, or other methods of rounding the edges of the electrode 100, as described in more detail herein.

[0040] All or a portion of the electrode 100 can comprise an electrically conductive material. For example, all of the electrode 100 can be made entirely of gold, silver, platinum, palladium, or stainless steel (and their respective alloys). Alternatively, only a portion of the electrode 100 (e.g., the tissue-facing surface 114) can be made from the above materials. These materials also have high thermal conductivity, allowing minimal heat generated on the tissue (i.e., due to the ablation energy delivered to the tissue) to be conducted through the electrode 100 to the back side of the electrode 100 (i.e., the inward-facing surface 112) and then to the blood pool within the heart 12. The electrode can be configured to deliver electrical pulses having a peak voltage of at least 900 volts (V).

[0041] The electrode 100 may include one or more end recesses 118, one positioned near the proximal end 106 and one positioned near the distal end 108. The end recesses 118 may be positioned along the longitudinal axis 104 and aligned with the lumen 110 extending through the body 102. The end recesses 118 may be configured to receive at least a portion of the adhesive 200 (described in more detail in connection with FIG. 6 ) positioned on the electrode 100 and spine 22. The end recesses 118 may help provide more surface area for the adhesive to adhere to the electrode 100. The end recesses 118 may help prevent the electrode 100 from rotating about the longitudinal axis 104 and may help ensure that the tissue-facing surface 114 is accurately positioned to contact tissue. In other words, end recess 118 may be configured to receive at least a portion of adhesive 200 and partially interlock with adhesive 200 to act as a mechanical lock that prevents electrode 100 from rotating about longitudinal axis 104. Additionally or alternatively, end recess 118 may also be configured to receive one or more wires so that the wires can be glued or welded in place.

[0042] The electrode 100 may further include one or more recesses 120 positioned at the proximal end 106 and the distal end 108 at locations on the electrode 100 that are at least partially between the tissue-facing surface 114 and the lumen 110. Figure 4A is a side view of the electrode 100, and Figure 4B is a detailed view of the electrode 100 of Figure 4A, in accordance with the disclosed technology. As shown, the recesses 120 may include a first gap distance 122 proximate an outer portion of the recess 120 and a second gap distance 124 at an inner portion of the recess 120. The second gap distance 124 may be greater than the first gap distance 122. That is, a first portion of the recess 120 can extend into the body 102 of the electrode 100 a first depth having a first gap distance 122, and a second portion of the recess 120 can extend from an end of the first portion into the body 102 a second depth having a second gap distance 124 that is greater than the first gap distance 122. In this manner, the recess 120 can be configured to receive the adhesive 200 while it is in a fluid (or semi-fluid) state and then prevent the adhesive 200 from being removed from the recess 120 once it hardens. That is, once the adhesive 200 becomes a solid material, the adhesive 200 in the second portion having the second gap distance 124 cannot be pulled back through the first portion having the smaller first gap distance 122. That is, the adhesive 200 can form a bayonet connection with the electrode 100 through the recess 120, helping to ensure that the electrode 100 is secured to the spine 22.

[0043] Figure 5 is an end view of electrode 100 in accordance with the disclosed technology, and Figure 6 is a cross-sectional view of electrode 100 of Figure 5 along line AA. As shown in Figure 5, electrode 100 can include rounded contours to further assist electrode 100 in forming an atraumatic shape. In some embodiments, tissue-facing surface 114 can have a smaller surface area than inward-facing surface 112, while in other embodiments, tissue-facing surface 114 can have a larger or equal surface area compared to inward-facing surface 112.

[0044] As shown more clearly in FIG. 6 , adhesive 200 may be at least partially disposed on electrode 100 and spine 22 to secure electrode 100 to spine 22. Recess 120 may be configured to receive at least a portion of adhesive 200, thereby preventing adhesive 200 from peeling off electrode 100. As shown, adhesive 200 may extend around the top, bottom, and sides (not visible in FIG. 6 ) of spine 22 and electrode 100 to help secure electrode 100 to spine 22. In this manner, adhesive 200 may be at least partially disposed within recess 120 and end recess 118.

[0045] The adhesive 200 may be a non-conductive material that can initially be in a liquid or non-solid form and then hardened to a solid or semi-solid form, thereby securing the electrode 100 to the spine 22. In this manner, the adhesive 200 may be flowed into the recess 120 when placed and then hardened, thereby preventing the adhesive 200 from peeling off or otherwise becoming unattached to the electrode 100. The adhesive 200 may be a polymeric material or other biocompatible adhesive, and may be an air-curing adhesive, a light-curing adhesive, a heat-curing adhesive (including a heat-curing silicone adhesive), an ultraviolet (UV)-curing adhesive, a cyanoacrylate adhesive, an acrylic, an epoxy, polymethyl methacrylate (PMMA), fibrin, a polyurethane adhesive, a reflow polymer (such as polyurethane, polyetheretherketone (PEEK), or polyethylene terephthalate (PET)), or other suitable type of adhesive.

[0046] 7 is a flowchart of a method 700 of manufacturing a medical probe in accordance with the techniques of this disclosure. Method 700 can include forming (702) a lumen through a body of an electrode from a proximal end to a distal end of the electrode. Method 700 can include forming (704) a first recess in the proximal end of the electrode and forming (706) a second recess in the distal end of the electrode. The first and second recesses can include first and second portions in accordance with recess 120, which is described in more detail herein.

[0047] The method 700 may further include tumbling the electrode (708) to form an atraumatic edge along the body of the electrode and then inserting a spine through the lumen of the electrode (710). The method 700 may include disposing (712) a non-conductive material (e.g., an adhesive as described more fully herein) at least partially over the spine and at least partially over the electrode. The non-conductive material may extend into the first recess and the second recess, as described more fully herein. In this manner, the electrode 100 may be secured to the spine and prevented from sliding along the length of the spine.

[0048] The techniques of the present disclosure described herein can be further understood in accordance with the following clauses.

[0049] Clause 1: An electrode for a medical probe, the electrode comprising: a body extending along a longitudinal axis from a proximal end to a distal end, the body defining a tissue-facing surface, an inner lumen extending through the body along the longitudinal axis from the proximal end to the distal end, and one or more recesses extending through the body transversely to the longitudinal axis of the body and disposed between the tissue-facing surface and the inner lumen, the one or more recesses defining a first portion extending into the body to a first depth and including a first gap distance, and a second portion extending from the first portion into the body to a second depth, the second portion comprising a second gap distance greater than the first gap distance.

[0050] Clause 2: The electrode described in clause 1, wherein the lumen is configured to receive a spine of a medical probe.

[0051] Clause 3: An electrode described in any one of clauses 1 or 2, wherein the one or more recesses are configured to receive a non-conductive material at least partially disposed on the spine and the electrode.

[0052] Clause 4: An electrode described in any one of clauses 1 to 3, wherein the body further defines an inward-facing surface, and wherein the one or more recesses are positioned closer to the tissue-facing surface than the inward-facing surface.

[0053] Clause 5: An electrode as described in Clause 4, wherein the one or more recesses include a first recess disposed nearest the distal end of the body and a second recess disposed nearest the proximal end of the body.

[0054] Clause 6: An electrode described in any one of clauses 1 to 5, wherein the body further defines one or more atraumatic edges.

[0055] Clause 7: An electrode described in any one of clauses 1 to 6, wherein the tissue-facing surface is configured to deliver ablation energy to tissue.

[0056] Clause 8: A medical probe as described in clause 7, wherein the tissue-facing surface is configured to deliver an electrical pulse for irreversible electroporation, the pulse having a peak voltage of at least 900 volts (V).

[0057] Clause 9: A medical probe, the medical probe comprising: a tubular shaft including a proximal end and a distal end, the tubular shaft extending along a longitudinal axis of the tubular shaft; and an expandable basket assembly coupled to the distal end of the tubular shaft, the expandable basket assembly comprising: a plurality of spines coupled to the tubular shaft and configured to bend radially outward from the longitudinal axis of the tubular shaft; and a plurality of electrodes attached to the plurality of spines, each electrode of the plurality of electrodes being a body. a body extending along a longitudinal axis of the body from a proximal end to a distal end thereof and defining a tissue-facing surface, an internal lumen extending through the body from the proximal end to the distal end, and one or more recesses disposed transverse to the longitudinal axis of the body between the tissue-facing surface and the internal lumen, wherein the one or more recesses define a first portion extending into the body to a first depth and including a first gap distance, and a second portion extending from the first portion into the body to a second depth, the second portion comprising a second gap distance greater than the first gap distance.

[0058] Clause 10: The medical probe of clause 9, wherein the lumen is configured to receive each spine of the plurality of spines.

[0059] Clause 11: A medical probe described in either clause 9 or clause 10, wherein one or more recesses are configured to receive an electrode and a non-conductive material at least partially disposed on each of the plurality of spines to secure the electrode to each of the spines.

[0060] Clause 12: A medical probe described in any one of clauses 9 to 11, wherein the body of each electrode of the plurality of electrodes further defines an inward-facing surface, and wherein one or more recesses are positioned closer to the tissue-facing surface than the inward-facing surface.

[0061] Clause 13: A medical probe as described in Clause 12, wherein the inward-facing surface is configured to face an inner portion of the expandable basket assembly when the multiple electrodes are arranged on the multiple spines.

[0062] Clause 14: A medical probe as described in Clause 13, wherein the tissue-facing surface faces outward from the inner portion of the expandable basket assembly and is configured to contact tissue.

[0063] Clause 15: A medical probe described in any one of clauses 9 to 14, wherein the one or more recesses include a first recess disposed closest to the distal end of the body and a second recess disposed closest to the proximal end of the body.

[0064] Clause 16: A medical probe described in any one of clauses 9 to 15, wherein the body of each electrode of the plurality of electrodes further defines one or more atraumatic edges.

[0065] Clause 17: A medical probe described in any one of clauses 9 to 16, wherein each electrode of the plurality of electrodes is configured to deliver ablation energy to tissue.

[0066] Clause 18: A medical probe described in any one of clauses 9 to 17, wherein the plurality of electrodes are configured to deliver electrical pulses for irreversible electroporation, the pulses having a peak voltage of at least 900 volts (V).

[0067] Clause 19: A method of manufacturing an electrode for a medical probe, the method including: forming a lumen through a body of the electrode extending from a proximal end to a distal end along a longitudinal axis; and forming one or more recesses extending along the body transversely to the longitudinal axis, the one or more recesses defining a first portion extending a first depth into the body and including a first gap distance, and a second portion extending a second depth from the first portion into the body, the second portion having a second gap distance greater than the first gap distance.

[0068] Clause 20: The method of clause 19, further comprising tumbling the electrode to form an atraumatic edge.

[0069] The above-described 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 subcombinations of the various features previously described herein, as well as variations and modifications thereof not disclosed in the prior art that will occur to those skilled in the art upon reading the foregoing description.

[0070] [Embodiment] (1) An electrode for a medical probe, the electrode comprising: a body extending along a longitudinal axis from a proximal end to a distal end, said body comprising: a tissue-facing surface; a lumen extending through the body along the longitudinal axis from the proximal end to the distal end; one or more recesses extending through the body transversely to the longitudinal axis of the body and disposed between the tissue-facing surface and the lumen, a first portion extending into the body to a first depth and including a first gap distance; and a second portion extending from the first portion into the body at a second depth, the second portion comprising a second gap distance greater than the first gap distance; one or more recesses defining The electrode comprises a body defining a (2) The electrode described in embodiment 1, wherein the inner lumen is configured to receive a spine of the medical probe. (3) The electrode of embodiment 2, wherein the one or more recesses are configured to receive a non-conductive material at least partially disposed on the spine and the electrode. (4) An electrode as described in embodiment 1, wherein the body further defines an inward-facing surface, and the one or more recesses are positioned closer to the tissue-facing surface than the inward-facing surface. (5) The electrode of embodiment 4, wherein the one or more recesses include a first recess disposed nearest the distal end of the body and a second recess disposed nearest the proximal end of the body.

[0071] (6) An electrode as described in embodiment 1, wherein the body further defines one or more atraumatic edges. (7) An electrode as described in embodiment 1, wherein the tissue-facing surface is configured to deliver ablation energy to tissue. (8) A medical probe as described in embodiment 7, wherein the tissue-facing surface is configured to deliver an electrical pulse for irreversible electroporation, the pulse having a peak voltage of at least 900 volts (V). (9) 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 tubular shaft; an expandable basket assembly coupled to the distal end of the tubular shaft, the expandable basket assembly comprising: a plurality of spines coupled to the tubular shaft and configured to bend radially outward from the longitudinal axis of the tubular shaft; and a plurality of electrodes disposed on the plurality of spines, each electrode of the plurality of electrodes comprising: a body extending along a longitudinal axis of the body from a proximal end to a distal end thereof and defining a tissue-facing surface, a lumen extending through the body from the proximal end to the distal end, and one or more recesses disposed transverse to the longitudinal axis of the body between the tissue-facing surface and the lumen, the one or more recesses comprising: a first portion extending into the body to a first depth and including a first gap distance; and a second portion extending from the first portion into the body at a second depth, the second portion comprising a second gap distance greater than the first gap distance; Medical probes. (10) A medical probe according to embodiment 9, wherein the lumen is configured to receive each of the plurality of spines.

[0072] (11) A medical probe as described in embodiment 9, wherein the one or more recesses are configured to receive a non-conductive material at least partially disposed on the electrode and each of the spines to secure the electrode to each of the plurality of spines. (12) A medical probe as described in embodiment 9, wherein the body of each electrode of the plurality of electrodes further defines an inward-facing surface, and the one or more recesses are positioned closer to the tissue-facing surface than the inward-facing surface. (13) The medical probe according to claim 12, wherein the inward surface is configured to face an inner portion of the expandable basket assembly when the plurality of electrodes are disposed on the plurality of spines. (14) The medical probe according to embodiment 13, wherein the tissue-facing surface faces outward from the inner portion of the expandable basket assembly and is configured to contact tissue. (15) A medical probe as described in embodiment 9, wherein the one or more recesses include a first recess disposed closest to the distal end of the body and a second recess disposed closest to the proximal end of the body.

[0073] (16) A medical probe according to embodiment 9, wherein the body of each electrode of the plurality of electrodes further defines one or more atraumatic edges. (17) A medical probe as described in embodiment 9, wherein each electrode of the plurality of electrodes is configured to deliver ablation energy to tissue. (18) The medical probe of embodiment 9, wherein the plurality of electrodes are configured to deliver an electrical pulse for irreversible electroporation, the pulse having a peak voltage of at least 900 volts (V). (19) A method of manufacturing an electrode for a medical probe, said method comprising: forming a lumen through the body of the electrode and extending along a longitudinal axis from the proximal end to the distal end; and forming one or more recesses extending along the body transversely to the longitudinal axis, the one or more recesses comprising: a first portion extending into the body to a first depth and including a first gap distance; and a second portion extending from the first portion into the body at a second depth, the second portion comprising a second gap distance greater than the first gap distance; method. (20) The method of embodiment 19, further comprising tumbling the electrode to form an atraumatic edge.

Claims

1. 1. An electrode for a medical probe, said electrode comprising: a body extending along a longitudinal axis from a proximal end to a distal end, said body comprising: a tissue-facing surface; and a lumen extending through the body along the longitudinal axis from the proximal end to the distal end; one or more recesses extending through the body transversely to the longitudinal axis of the body and disposed between the tissue-facing surface and the lumen, a first portion extending into the body to a first depth and including a first gap distance; and a second portion extending from the first portion into the body at a second depth, the second portion comprising a second gap distance greater than the first gap distance; one or more recesses defining The electrode comprises a body defining a

2. The electrode of claim 1 , wherein the lumen is configured to receive a spine of the medical probe.

3. The electrode of claim 2 , wherein the one or more recesses are configured to receive a non-conductive material at least partially disposed over the spine and the electrode.

4. The electrode of claim 1 , wherein the body further defines an inwardly facing surface, and the one or more recesses are positioned closer to the tissue-facing surface than to the inwardly facing surface.

5. 5. The electrode of claim 4, wherein the one or more recesses include a first recess disposed proximate the distal end of the body and a second recess disposed proximate the proximal end of the body.

6. The electrode of claim 1 , wherein the body further defines one or more atraumatic edges.

7. The electrode of claim 1 , wherein the tissue-facing surface is configured to deliver ablation energy to tissue.

8. 8. The medical probe of claim 7, wherein the tissue-facing surface is configured to deliver an electrical pulse for irreversible electroporation, the pulse having a peak voltage of at least 900 volts (V).

9. A medical probe, the medical probe comprising: a tubular shaft including a proximal end and a distal end, the tubular shaft extending along a longitudinal axis of the tubular shaft; an expandable basket assembly coupled to the distal end of the tubular shaft, the expandable basket assembly comprising: a plurality of spines coupled to the tubular shaft and configured to bend radially outward from the longitudinal axis of the tubular shaft; and a plurality of electrodes disposed on the plurality of spines, each electrode of the plurality of electrodes comprising: a body extending along a longitudinal axis of the body from a proximal end to a distal end thereof and defining a tissue-facing surface, a lumen extending through the body from the proximal end to the distal end, and one or more recesses disposed transverse to the longitudinal axis of the body between the tissue-facing surface and the lumen, the one or more recesses comprising: a first portion extending into the body to a first depth and including a first gap distance; and a second portion extending from the first portion into the body at a second depth, the second portion comprising a second gap distance greater than the first gap distance; Medical probes.

10. The medical probe of claim 9 , wherein the lumen is configured to receive each spine of the plurality of spines.

11. 10. The medical probe of claim 9, wherein the one or more recesses are configured to receive a non-conductive material at least partially disposed on the electrode and the respective spine to secure the electrode to the respective spine of the plurality of spines.

12. 10. The medical probe of claim 9, wherein the body of each electrode of the plurality of electrodes further defines an inward-facing surface, and the one or more recesses are positioned closer to the tissue-facing surface than the inward-facing surface.

13. The medical probe of claim 12 , wherein the inwardly facing surface is configured to face an interior portion of the expandable basket assembly when the plurality of electrodes are disposed on the plurality of spines.

14. The medical probe of claim 13 , wherein the tissue-facing surface faces outward from the inner portion of the expandable basket assembly and is configured to contact tissue.

15. 10. The medical probe of claim 9, wherein the one or more recesses include a first recess disposed proximate the distal end of the body and a second recess disposed proximate the proximal end of the body.

16. The medical probe of claim 9 , wherein the body of each electrode of the plurality of electrodes further defines one or more atraumatic edges.

17. The medical probe of claim 9 , wherein each electrode of the plurality of electrodes is configured to deliver ablation energy to tissue.

18. 10. The medical probe of claim 9, wherein the plurality of electrodes are configured to deliver electrical pulses for irreversible electroporation, the pulses having a peak voltage of at least 900 volts (V).

19. 1. A method of manufacturing an electrode for a medical probe, the method comprising: forming a lumen through the body of the electrode and extending along a longitudinal axis from the proximal end to the distal end; and forming one or more recesses extending along the body transversely to the longitudinal axis, the one or more recesses comprising: a first portion extending into the body to a first depth and including a first gap distance; and a second portion extending from the first portion into the body at a second depth, the second portion comprising a second gap distance greater than the first gap distance; method.

20. 20. The method of claim 19, further comprising tumbling the electrode to form an atraumatic edge.

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