Patent Application
20240180615
The present invention relates generally to medical devices, and in particular medical probes with electrodes, and further relates to, but not exclusively, medical probes suitable for use to induce irreversible electroporation (IRE) of cardiac tissues.
Cardiac arrhythmias, such as atrial fibrillation (AF), occur when regions of cardiac tissue abnormally conduct electric signals to adjacent tissue. This disrupts the normal cardiac cycle and causes asynchronous rhythm. Certain procedures exist for treating arrhythmia, including surgically disrupting the origin of the signals causing the arrhythmia and disrupting the conducting pathway for such signals. By selectively ablating cardiac tissue by application of energy via a catheter, it is sometimes possible to cease or modify the propagation of unwanted electrical signals from one portion of the heart to another.
Many current ablation approaches in the art utilize radiofrequency (RF) electrical energy to heat tissue. RF ablation can have certain risks related to thermal heating which can lead to tissue charring, burning, steam pop, phrenic nerve palsy, pulmonary vein stenosis, and esophageal fistula.
Cryoablation is an alternative approach to RF ablation that generally reduces thermal risks associated with RF ablation. Maneuvering cryoablation devices and selectively applying cryoablation, however, is generally more challenging compared to RF ablation; therefore, cryoablation is not viable in certain anatomical geometries which may be reached by electrical ablation devices.
Some ablation approaches use irreversible electroporation (IRE) to ablate cardiac tissue using nonthermal ablation methods. IRE delivers short pulses of high voltage to tissues and generates an unrecoverable permeabilization of cell membranes. Delivery of IRE energy to tissues using multi-electrode probes was previously proposed in the patent literature.
Examples of systems and devices configured for IRE ablation are disclosed in U.S. Patent Pub. No. 2021/0169550A1, 2021/0169567A1, 2021/0169568A1, 2021/0161592A1, 2021/0196372A1, 2021/0177503A1, and 2021/0186604A1, each of which are incorporated herein by reference and attached in the Appendix included in priority application No. 63/386,278.
Regions of cardiac tissue can be mapped by a catheter to identify the abnormal electrical signals. The same or different medical probe can be used to perform ablation. Some example probes include a number of spines with electrodes positioned thereon. The electrodes are generally attached to the spines and secured in place by soldering, welding, or using an adhesive. Due to the small size of the spines and the electrodes, however, soldering, welding, or adhering the electrodes to the spines can be a difficult task, increasing the manufacturing time and cost and the chances that the electrode fails due to an improper bond, misalignment, or strain on the spine. What is needed, therefore, are systems and methods of attaching an electrode to a spine of a basket assembly without the need for soldering, welding, or using adhesive.
There is provided, in accordance with an embodiment of the present invention, an electrode for a medical probe, including an electrode body configured to deliver electrical energy to biological tissues, and one or more legs attached to the electrode body and configured to bend at least partially around or into a spine of a basket catheter so as to be attached thereto. The one or more legs can extend from an edge of the electrode body and can be configured to be bent such that the electrode is crimped to the spine.
The electrode body can further include a proximal end having a first thickness and a distal end having a second thickness, the second thickness being greater than the first thickness. The electrode body can taper from the first thickness to the second thickness between the proximal end and the distal end. The first thickness and the second thickness can each be measured in a height direction of the electrode body. The first thickness and the second thickness can also each be measured in a width direction of the electrode body.
The electrode body can further include an undulating outer surface. The undulating outer surface can be configured to permit the electrode body to bend.
The electrode can be configured to deliver electrical pulses having a peak voltage of at least 900 volts (V).
The disclosed technology includes an electrode for a medical probe, the electrode including an electrode body configured to deliver electrical energy to biological tissues. In some examples, the electrode body can define a lumen therethrough configured to receive a spine of a basket catheter and/or an electrical wire. The electrode body can include a proximal end having a first thickness and a distal end having a second thickness, the second thickness being greater than the first thickness. The disclosed technology can include one or more legs attached to the electrode body and configured to bend at least partially around or into a spine of a basket catheter so as to be attached thereto. The electrode body can be tapered from the first thickness to the second thickness between the proximal end and the distal end. The first thickness and the second thickness can each be measured in a height direction of the electrode body. The first thickness and the second thickness can each be measured in a width direction of the electrode body.
The electrode body can further include an undulating outer surface. The undulating outer surface can be configured to permit the electrode body to bend. The one or more legs can include two or more legs attached to the electrode body and configured to bend at least partially around the spine of a basket catheter so as to be attached thereto. The one or more legs can extend from an edge of the electrode body and can be configured to be bent such that the electrode is crimped to the spine. The electrode can be configured to deliver electrical pulses having a peak voltage of at least 900 volts (V).
The disclosed technology can include an electrode for a medical probe. The electrode can include an electrode body configured to deliver electrical energy, the electrode body including an undulating outer surface configured to permit the electrode body to bend. The electrode body can comprise a spiral wound wire. The electrode body can be coated with a flexible material filling in recesses in the undulating outer surface. The electrode can include one or more windows cut into the flexible material exposing the electrode body.
The electrode can further include one or more legs attached to the electrode body and configured to bend at least partially around a spine of a basket catheter, the one or more legs can be configured to attach the electrode body to the spine. The one or more legs can extend from an edge of the electrode body and can be configured to be bent such that the electrode is crimped to the spine.
The electrode body can further include a proximal end having a first thickness and a distal end having a second thickness, the second thickness being greater than the first thickness. The electrode body can taper from the first thickness to the second thickness between the proximal end and the distal end. The first thickness and the second thickness can each be measured in a height direction of the electrode body. The first thickness and the second thickness can alternatively each be measured in a width direction of the electrode body. The electrode can be configured to deliver electrical pulses having a peak voltage of at least 900 volts (V).
The disclosed technology can include a medical probe. The medical probe can include an insertion tube having a proximal end and a distal end and extending along a longitudinal axis, and an expandable basket assembly coupled to the distal end of the insertion tube. The expandable basket assembly can include a plurality of spines extending along the longitudinal axis and configured to bow radially outward from the longitudinal axis when the expandable basket assembly is transitioned from a collapsed form to an expanded form. The expandable basket assembly can include a plurality of electrodes. Each electrode of the plurality of electrodes can be attached to a spine of the plurality of spines and include an electrode body configured to deliver electrical energy. Each electrode can include one or more legs attached to the electrode body and configured to bend at least partially around the spine of the plurality of spine to attach the electrode body to the spine. The one or more legs can extend from an edge of the electrode body and be configured to be bent such that the electrode is crimped to the spine.
In the medical probe, the electrode body can further include a proximal end having a first thickness and a distal end having a second thickness, the second thickness being greater than the first thickness. The electrode body can taper from the first thickness to the second thickness between the proximal end and the distal end. The first thickness and the second thickness can each be measured in a height direction of the electrode body. The first thickness and the second thickness can each be measured in a width direction of the electrode body. The electrode body further include an undulating outer surface. The undulating outer surface can be configured to permit the electrode body to bend. The electrode can be configured to deliver electrical pulses having a peak voltage of at least 900 volts (V).
Each spine of the plurality of spines can include a material selected from a group including of nitinol, cobalt chromium, stainless steel, titanium.
The disclosed technology can further include a medical probe including an insertion tube having a proximal end and a distal end and extending along a longitudinal axis, and an expandable basket assembly coupled to the distal end of the insertion tube. The expandable basket assembly can include a plurality of spines extending along the longitudinal axis and configured to bow radially outward from the longitudinal axis when the expandable basket assembly is transitioned from a collapsed form to an expanded form. The medical probe can further include a plurality of electrodes. Each electrode of the plurality of electrodes can be attached to a spine of the plurality of spines and include an electrode body configured to deliver electrical energy.
The electrode body can include a proximal end having a first thickness and a distal end having a second thickness, the second thickness being greater than the first thickness. The electrode body can taper from the first thickness to the second thickness between the proximal end and the distal end. The first thickness and the second thickness can each be measured in a height direction of the electrode body. The first thickness and the second thickness can each be measured in a width direction of the electrode body. The electrode body can further include an undulating outer surface. The undulating outer surface can be configured to permit the electrode body to bend. The electrode body can further include one or more legs attached to the electrode body and configured to bend at least partially around a spine of a basket catheter to attach the electrode body to the spine. The one or more legs can extend from an edge of the electrode body and can be configured to be bent such that the electrode is crimped to the spine. The electrode can be configured to deliver electrical pulses having a peak voltage of at least 900 volts (V). Each spine of the plurality of spines can include a material selected from a group including of nitinol, cobalt chromium, stainless steel, titanium.
The disclosed technology can further include a medical probe including an insertion tube having a proximal end and a distal end and extending along a longitudinal axis, and an expandable basket assembly coupled to the distal end of the insertion tube. The expandable basket assembly can include a plurality of spines extending along the longitudinal axis and configured to bow radially outward from the longitudinal axis when the expandable basket assembly is transitioned from a collapsed form to an expanded form. The expandable basket assembly can include a plurality of electrodes. Each electrode of the plurality of electrodes can be attached to a spine of the plurality of spines and include an electrode body configured to deliver electrical energy. The electrode body can include an undulating outer surface configured to permit the electrode body to bend. The electrode body can include a spiral wound wire. The body can be coated with a flexible material filling in recesses in the undulating outer surface. The electrode can further include one or more windows cut into the flexible material exposing the electrode body. The medical probe can further include one or more legs attached to the electrode body and configured to bend at least partially around a spine of a basket catheter. The one or more legs can be configured to attach the electrode body to the spine. The one or more legs can extend from an edge of the electrode body and can be configured to be bent such that the electrode is crimped to the spine.
The electrode body can further include a proximal end having a first thickness and a distal end having a second thickness, the second thickness being greater than the first thickness. The electrode body can taper from the first thickness to the second thickness between the proximal end and the distal end. The first thickness and the second thickness can each be measured in a height direction of the electrode body. The first thickness and the second thickness can alternatively each be measured in a width direction of the electrode body. The electrode can be configured to deliver electrical pulses having a peak voltage of at least 900 volts (V). Each spine of the plurality of spines can include a material selected from a group comprising of nitinol, cobalt chromium, stainless steel, titanium.
The disclosed technology can further include a method of attaching an electrode to a spine of a basket catheter. The method can include placing an electrode body against a spine with one or more legs attached to the electrode body extending beyond the spine and crimping the one or more legs around the spine to secure the electrode to the spine. The one or more legs can extend from an edge of the electrode body and can be configured to be bent such that the electrode is crimped to the spine.
The electrode body can further include a proximal end having a first thickness and a distal end having a second thickness, the second thickness being greater than the first thickness. The electrode body can taper from the first thickness to the second thickness between the proximal end and the distal end. The first thickness and the second thickness can each be measured in a height direction of the electrode body. Alternatively, the first thickness and the second thickness can each be measured in a width direction of the electrode body.
The electrode body can further include an undulating outer surface. The undulating outer surface can be configured to permit the electrode body to bend. The electrode can be configured to deliver electrical pulses having a peak voltage of at least 900 volts (V). The spine can include a material selected from a group including of nitinol, cobalt chromium, stainless steel, titanium. Alternatively, or in addition, the spine can include a polymer. The electrode can include a ring type electrode, a bulging-type electrode, or a rectangular electrode. The electrodes can be configured to deliver electrical pulses for irreversible electroporation, the pulses having a peak voltage of at least 900 volts (V).
The following detailed description should be read with reference to the drawings, in which like elements in different drawings are identically numbered. 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, not by way of limitation, the principles of the invention. This description will clearly enable one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what is presently believed to be the best mode of carrying out the invention.
As used herein, the terms “about” or “approximately” for any numerical values or ranges indicate a suitable dimensional tolerance that allows the part or collection of components to function for its intended purpose as described herein. More specifically, “about” or “approximately” may refer to the range of values ±20% of the recited value, e.g. “about 90%” may refer to the range of values from 71% to 110%. In addition, as used herein, the terms “patient,” “host,” “user,” and “subject” refer to any human or animal subject and are not intended to limit the systems or methods to human use, although use of the subject invention in a human patient represents a preferred embodiment. As well, the term “proximal” indicates a location closer to the operator or physician whereas “distal” indicates a location further away to the operator or physician.
As discussed herein, vasculature of a “patient,” “host,” “user,” and “subject” can be vasculature of a human or any animal. It should be appreciated that an animal can be a variety of any applicable type, including, but not limited thereto, mammal, veterinarian animal, livestock animal or pet type animal, etc. As an example, the animal can be a laboratory animal specifically selected to have certain characteristics similar to a human (e.g., rat, dog, pig, monkey, or the like). It should be appreciated that the subject can be any applicable human patient, for example.
As discussed herein, “operator” can include a doctor, surgeon, technician, scientist, or any other individual or delivery instrumentation associated with delivery of a multi-electrode catheter for the treatment of drug refractory atrial fibrillation to a subject.
As discussed herein, the term “ablate” or “ablation”, as it relates to the devices and corresponding systems of this disclosure, refers to components and structural features configured to reduce or prevent the generation of erratic cardiac signals in the cells by utilizing non-thermal energy, such as irreversible electroporation (IRE), referred throughout this disclosure interchangeably as pulsed electric field (PEF) and pulsed field ablation (PFA). Ablating or ablation as it relates to the devices and corresponding systems of this disclosure is used throughout this disclosure in reference to non-thermal ablation of cardiac tissue for certain 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 to achieve various forms of bodily tissue ablation as understood by a person skilled in the relevant art.
As discussed herein, the terms “bipolar” and “unipolar” when used to refer to ablation schemes describe ablation schemes which differ with respect to electrical current path and electric field distribution. “Bipolar” refers to ablation scheme utilizing a current path between two electrodes that are both positioned at a treatment site; current density and electric flux density is typically approximately equal at each of the two electrodes. “Unipolar” refers to ablation scheme utilizing a current path between two electrodes where one electrode having a high current density and high electric flux density is positioned at a treatment site, and a second electrode having comparatively lower current density and lower electric flux density is positioned remotely from the treatment site.
As discussed herein, the terms “biphasic pulse” and “monophasic pulse” refer to respective electrical signals. “Biphasic pulse” refers to an electrical signal having a positive-voltage phase pulse (referred to herein as “positive phase”) and a negative-voltage phase pulse (referred to herein as “negative phase”). “Monophasic pulse” refers to an electrical signal having only a positive or only a negative phase. Preferably, a system providing the biphasic pulse is configured to prevent application of a direct current voltage (DC) to a patient. For instance, the average voltage of the biphasic pulse can be zero volts with respect to ground or other common reference voltage. Additionally, or alternatively, the system can include a capacitor or other protective component. Where voltage amplitude of the biphasic and/or monophasic pulse is described herein, it is understood that the expressed voltage amplitude is an absolute value of the approximate peak amplitude of each of the positive-voltage phase and/or the negative-voltage phase. Each phase of the biphasic and monophasic pulse preferably has a square shape having an essentially constant voltage amplitude during a majority of the phase duration. 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 the phase of the biphasic pulse.
As discussed herein, the terms “tubular” and “tube” are to be construed broadly and are not limited to a structure that is a right cylinder or strictly circumferential in cross-section or of a uniform cross-section throughout its length. For example, the tubular structures are generally illustrated as a substantially right cylindrical structure. However, the tubular structures may have a tapered or curved outer surface without departing from the scope of the present disclosure.
The term “temperature rating”, as used herein, 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 crumbling) of the component.
The present disclosure is related to systems, method or uses and devices for IRE ablation of cardiac tissue to treat cardiac arrhythmias. Ablative energies are typically provided to cardiac tissue by a tip portion of a catheter which can deliver ablative energy alongside the tissue to be ablated. Some example catheters include three-dimensional structures at the tip portion and are configured to administer ablative energy from various electrodes positioned on the three-dimensional structures. Ablative procedures incorporating such example catheters can be visualized using fluoroscopy.
Ablation of cardiac tissue using application of a thermal technique, such as radio frequency (RF) energy and cryoablation, to correct a malfunctioning heart is a well-known procedure. Typically, to successfully ablate using a thermal technique, cardiac electropotentials need to be measured at various locations of the myocardium. In addition, temperature measurements during ablation provide data enabling the efficacy of the ablation. Typically, for an ablation procedure using a thermal technique, the electropotentials and the temperatures are measured before, during, and after the actual ablation. RF approaches can have risks that can lead to tissue charring, burning, steam pop, phrenic nerve palsy, pulmonary vein stenosis, and esophageal fistula. Cryoablation is an alternative approach to RF ablation that can reduce some thermal risks associated with RF ablation. However maneuvering cryoablation devices and selectively applying cryoablation is generally more challenging compared to RF ablation; therefore, cryoablation is not viable in certain anatomical geometries which may be reached by electrical ablation devices.
The present disclosure can include electrodes configured for RF ablation, cryoablation, and/or irreversible electroporation (IRE). IRE can be referred to throughout this disclosure interchangeably as pulsed electric field (PEF) ablation and pulsed field ablation (PFA). IRE as discussed in this disclosure is a non-thermal cell death technology that can be used for ablation of atrial arrhythmias. To ablate using IRE/PEF, biphasic voltage pulses are applied to disrupt cellular structures of myocardium. The biphasic pulses are non-sinusoidal and can be tuned to target cells based on electrophysiology of the cells. In contrast, to ablate using RF, a sinusoidal voltage waveform is applied to produce heat at the treatment area, indiscriminately heating all cells in the treatment area. IRE therefore has the capability to spare adjacent heat sensitive structures or tissues which would be of benefit in the reduction of possible complications known with ablation or isolation modalities. Additionally, or alternatively, monophasic pulses can be utilized.
Electroporation can be induced by applying a pulsed electric field across biological cells to cause reversable (temporary) or irreversible (permanent) creation of pores in the cell membrane. The cells have a transmembrane electrostatic potential that is increased above a resting potential upon application of the pulsed electric field. While the transmembrane electrostatic potential remains below a threshold potential, the electroporation is reversable, meaning the pores can close when the applied pulse electric field is removed, and the cells can self-repair and survive. If the transmembrane electrostatic potential increases beyond the threshold potential, the electroporation is irreversible, and the cells become permanently permeable. As a result, the cells die due to a loss of homeostasis and typically die by apoptosis. Generally, cells of differing types have differing threshold potential. For instance, heart cells have a threshold potential of approximately 500 V/cm, whereas for bone it is 3000 V/cm. These differences in threshold potential allow IRE to selectively target tissue based on threshold potential.
The solution of this disclosure includes systems and methods for applying electrical signals from catheter electrodes positioned in the vicinity of myocardial tissue to generate a generate ablative energy to ablate the myocardial tissue. In some examples, the systems and methods can be effective to ablate targeted tissue by inducing irreversible electroporation. In some examples, the systems and methods can be effective to induce reversible electroporation as part of a diagnostic procedure. Reversible electroporation occurs when the electricity applied with the electrodes is below the electric field threshold of the target tissue allowing cells to repair. Reversible electroporation does not kill the cells but allows a physician to see the effect of reversible electroporation on electrical activation signals in the vicinity of the target location. Example systems and methods for reversible electroporation is disclosed in U.S. Patent Publication 2021/0162210, the entirety of which is incorporated herein by reference and attached in the Appendix included in priority application No. 63/386,278.
The pulsed electric field, and its effectiveness to induce reversible and/or irreversible electroporation, can be affected by physical parameters of the system and biphasic pulse parameters of the electrical signal. Physical parameters can include electrode contact area, electrode spacing, electrode geometry, 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, pulse interphase delay, inter-pulse delay, total application time, delivered energy, etc. In some examples, 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 of ablation including IRE are presented in U.S. Patent Publications 2021/0169550A1, 2021/0169567A1, 2021/0169568A1, 2021/0161592A1, 2021/0196372A1, 2021/0177503A1, and 2021/0186604A1, the entireties of each of which are incorporated herein by reference and attached in the Appendix included in priority application No. 63/386,278.
Reference is made to
Catheter 14 is an exemplary catheter that includes one and preferably multiple electrodes 26 optionally distributed over a plurality of spines 22 at basket catheter 28 and configured to sense the IEGM signals. Catheter 14 may additionally include a position sensor 29 embedded in or near basket catheter 28 for tracking position and orientation of basket catheter 28. Optionally and preferably, position sensor 29 is a magnetic based position sensor including three magnetic coils for sensing three-dimensional (3D) position and orientation.
Magnetic based position sensor 29 may be operated together with a location pad 25 including a plurality of magnetic coils 32 configured to generate magnetic fields in a predefined working volume. Real time position of basket catheter 28 of catheter 14 may be tracked based on magnetic fields generated with location pad 25 and sensed by magnetic based position sensor 29. Details of the magnetic based position sensing technology are described in U.S. Pat. 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; 6,892,091, each of which are incorporated herein by reference and attached in the Appendix included in priority application No. 63/386,278
System 10 includes one or more electrode patches 38 positioned for skin contact on patient 23 to establish location reference for location pad 25 as well as impedance-based tracking of electrodes 26. For impedance-based tracking, electrical current is directed toward electrodes 26 and sensed at electrode skin patches 38 so that the location of each electrode can be triangulated via the electrode patches 38. Details of the impedance-based location tracking technology are described in U.S. Pat. Nos. 7,536,218; 7,756,576; 7,848,787; 7,869,865; and 8,456,182, each of which are incorporated herein by reference and attached in the Appendix included in priority application No. 63/386,278.
A recorder 11 displays electrograms 21 captured with body surface ECG electrodes 18 and intracardiac electrograms (IEGM) captured with electrodes 26 of catheter 14. Recorder 11 may include pacing capability for pacing the heart rhythm and/or may be electrically connected to a standalone pacer.
System 10 may include an ablation energy generator 50 that is adapted to conduct ablative energy to one or more of electrodes at a distal tip of a catheter configured for ablating.
Energy produced by ablation energy generator 50 may include, but is not limited to, radiofrequency (RF) energy or pulsed-field ablation (PFA) energy, including monopolar or bipolar high-voltage DC pulses as may be used to effect irreversible electroporation (IRE), or combinations thereof.
Patient interface unit (PIU) 30 is an interface configured to establish electrical communication between catheters, electrophysiological equipment, power supply and a workstation 55 for controlling operation of system 10. Electrophysiological equipment of system 10 may include for example, multiple catheters, location pad 25, body surface ECG electrodes 18, electrode patches 38, ablation energy generator 50, and recorder 11. Optionally and preferably, PIU 30 additionally includes processing capability for implementing real-time computations of location of the catheters and for performing ECG calculations.
Workstation 55 includes memory, processor unit with memory or storage with appropriate operating software loaded therein, and user interface capability. Workstation 55 may provide multiple functions, optionally including (1) modeling the endocardial anatomy in three-dimensions (3D) and rendering the model or anatomical map 20 for display on a display device 27, (2) displaying on display device 27 activation sequences (or other data) compiled from recorded electrograms 21 in representative visual indicia or imagery superimposed on the rendered anatomical map 20, (3) displaying real-time location and orientation of multiple catheters within the heart chamber, and (5) displaying on display device 27 sites of interest such as places where ablation energy has been applied. One commercial product embodying elements of the system 10 is available as the CARTO™ 3 System, available from Biosense Webster, Inc., 31A Technology Drive, Irvine, CA 92618.
As shown in
As will be appreciated by one skilled in the art with the benefit of this disclosure, the basket assembly 28 shown in
The spines 22 can be formed from a single sheet of planar material to form a generally star shape. In other words, the spines 22 can be formed from the single sheet of planar material such that the spines 22 converge toward a central intersection. The intersection can be a solid piece of material or include one or more apertures.
As will be appreciated, the spine 22 can be electrically isolated from the electrode 26 to prevent arcing from the electrode 26 to the spine 22. For example, insulative jackets can be positioned between the spine 22 and the electrode 26, but one of skill in the art will appreciate that other insulative coverings are contemplated. For example, an insulative coating can be applied to the spine 22, the electrodes 26, or both. The insulative jackets can be made from a biocompatible, electrically insulative material such as polyamide-polyether (Pebax) copolymers, polyethylene terephthalate (PET), urethanes, polyimide, parylene, silicone, etc. In some examples, insulative material can include biocompatible polymers including, without limitation, polyetheretherketone (PEEK), polyglycolic acid (PGA), poly(lactic-co-glycolic acid) copolymer (PLGA), polycaprolactive (PCL), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly-L-lactide, polydioxanone, polycarbonates, and polyanhydrides with the ratio of certain polymers being selected to control the degree of inflammatory response. Insulative jackets 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, zinc oxide, and the like.
In embodiments described herein, electrodes 26 can be configured to deliver ablation energy (RF and/or IRE) to tissue in heart 12. In addition to using electrodes 26 to deliver ablation energy, the electrodes can also be used to determine the location of medical probe 39 and/or to measure a physiological property such as local surface electrical potentials at respective locations on tissue in heart 12. The electrodes 26 can be biased such that a greater portion of the electrode 26 faces outwardly from the medical probe 39 such that the electrodes 26 deliver a greater amount of electrical energy outwardly away from the medical probe 39 (i.e., toward the heart 12 tissue) than inwardly toward the medical probe 39.
Examples of materials ideally suited for forming electrodes 26 include gold, platinum, and palladium (and their respective alloys). These materials also have 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 electrodes to the back side of the electrodes (i.e., the portions of the electrodes on the inner sides of the spines), and then to the blood pool in heart 12.
As shown in
In some examples, the legs 342 can be crimped into the spine 22 to further secure the electrode 326 to the spine 22. For example, the legs 342 can be pointed so as to allow them to dig into the spine 22 for added security. Each of the legs 342 can taper from an end attached to the electrode body 340 to a pointed end opposite the electrode body 340. In other examples, a first leg 342 can overlap with a second leg 342 around the spine 22 to engage the second leg 342. The first leg 342 can be positioned opposite the second leg 342 on the electrode body 340. To illustrate further, the legs 342 can include tongue-and-groove type unions, or any other suitable union type, that do not allow the legs 342 to disengage from one another once engaged.
The electrode 326 can include as few as one and up to twelve legs 342. If the electrode 326 includes only a single leg 342, the single leg 342 can be configured to extend from a first side all the way to a second side of the electrode body 340 when bent around the spine 22. As another example, the number of legs 342 can include four legs 342 and the legs 342 can be dispersed evenly on opposite sides of the electrode body 340. In other examples, the number of legs 342 can be different on either side of the electrode body 340 so as to allow the legs 342 to not overlap when crimped around or into the spine 22. Generally, fewer (for example two or fewer) legs 342 allow for the spine 22 to flex more freely when secured to the spine 22 as compared to a greater number of legs 342 (for example four or more) which allow the spine 22 to flex less.
The electrode body 340 can in some examples be rounded so as to reduce drag and/or snagging on tissue or devices. This can for example, facilitate easier retraction of the medical probe 39 into the tube 31.
The undulating outer surface 446 can be configured to permit the electrode body 440 to bend. The electrode 426 can include an electrode body 440 configured to conduct electrical energy for ablation and/or mapping of electrical signals in tissue of a body part. For example, the electrode 426 can be configured to ablation or mapping of cardiac tissue. The undulating outer surface 446 can permit the electrode body 440 to bend by having a plurality of depressions and ridges along an outer surface such that the electrode is better able to bend. In other words, the undulating outer surface 446 can have a sinusoidal or semi-sinusoidal profile when viewed from a side of the electrode 426. Although only a single side (outwardly-facing side when assembled in the basket assembly 28) of the electrode 426 is shown as having an undulating outer surface 446, one of skill in the art will appreciate that two or more sides of the electrode 426 can have an undulating outer surface 446.
The electrode 426 can have a flexible material coating 450 that can serve to prevent blood from clotting in the depressions formed in the undulating outer surface 446 of the electrode body 440. The flexible material coating 450 can be a polymer material or other suitable material that can bend with the electrode 426 when it is bent while also being biocompatible for insertion into a body. The flexible material coating 450 can be added to the electrode body 426 by spraying, dipping, printing, wrapping, or any other suitable manufacturing method depending on the particular application.
To ensure the electrode 426 is capable of conducting electrical energy between tissue in a body, the electrode 426 can include one or more window 444 formed into the flexible material coating 450. The windows 444 can be sized to allow sufficient contact between the electrode 426 and tissue. The windows 444 can be formed by laser cutting, chemically etching, mechanically cutting, or otherwise removing the flexible material coating 450 at selected locations along the electrode 426. For example, the windows 444 can be formed into the flexible material coating 450 at locations between recesses formed in the undulating outer surface 446. In this way, the flexible material coating 450 can fill in the recesses of the undulating outer surface 446 to prevent blood clots in those locations.
Similar to the electrode 326, the electrode 426 can further include one or more legs 442 attached to the electrode body 440 and configured to bend at least partially around a spine 22 of a basket catheter 28 to attach the electrode body 340 to the spine 22. The one or more legs 442 can extend from an edge of the electrode body 340 and can be configured to be bent such that the electrode is crimped to the spine 22. By attaching the legs 442 to the electrode body 440 where the thicker portions of the undulating outer surface 446 are present, the electrode body 340 can still be permitted to bend as previously described. In other words, the legs 442 can be aligned with ridges of the undulating outer surface 446 rather than depressions of the undulating outer surface 446. In other examples, the legs 442 can be aligned with depressions of the undulating outer surface 446 to permit the electrode 426 to have more flexibility.
In some examples such as that of
In some examples, the electrode 626 can be oriented with the proximal end 648 being smaller than the distal end 650 so as to facilitate easier retraction of the medical probe 39 into the tube 31. The angle at which the electrode 626 tapers from the proximal end 648 to the distal end 650 can be varied to ensure the electrode 626 is able to retract easily into the tube 31 while also having sufficient surface area for mapping and/or ablation of tissue.
Although not shown, it will be appreciated that the electrode 626 can further include an undulating outer surface 446 as described previously herein. In other words, the various examples of electrodes described herein include features that can be incorporated into an electrode to meet a particular design consideration. For example, the electrode may have legs 642, and/or an undulating outer surface 446, and/or a tapering body (e.g., electrode 626) as desired for a particular application.
The electrodes described in relation to method 700 can be configured to deliver electrical pulses having a peak voltage of at least 900 volts (V). The spine can include a material selected from a group including of nitinol, cobalt chromium, stainless steel, titanium. Alternatively, or in addition, the spine can include a polymer. The electrode can include a ring type electrode, a bulging type electrode, or a rectangular electrode. The electrodes can be configured to deliver electrical pulses for irreversible electroporation, the pulses having a peak voltage of at least 900 volts (V).
The electrode can be configured to deliver electrical pulses having a peak voltage of at least 900 volts (V). The electrode can be configured to deliver electrical pulses having a peak voltage of at least 900 volts (V).
As will be appreciated, the method 700 just described can be varied in accordance with the various elements and implementations described herein. That is, methods in accordance with the disclosed technology can include all or some of the steps described above and/or can include additional steps not expressly disclosed above. Further, methods in accordance with the disclosed technology can include some, but not all, of a particular step described above. Further still, various methods described herein can be combined in full or in part. That is, methods in accordance with the disclosed technology can include at least some elements or steps of a first method and at least some elements or steps of a second method.
The disclosed technology described herein can be further understood according to the following clauses:
The embodiments described above are cited by way of example, and the present invention is not limited by what has been particularly shown and described hereinabove. Rather, the scope of the invention includes both combinations and sub combinations of the various features described hereinabove, as well as variations and modifications thereof which would occur to persons skilled in the art upon reading the foregoing description and which are not disclosed in the prior art.
This application claims the benefit of priority under 35 U.S.C. § 119 to prior filed U.S. Provisional Patent Application No. 63/386,278, filed Dec. 6, 2022, the entire contents of which is hereby incorporated by reference as if set forth in full herein.
| Number | Date | Country | |
|---|---|---|---|
| 63386278 | Dec 2022 | US |
