Patent Application
20230149069
Cardiac arrhythmia, such as atrial fibrillation, occurs when regions of cardiac tissue abnormally conduct electric signals to adjacent tissue, thereby disrupting the normal cardiac cycle and causing asynchronous rhythm. Sources of undesired signals can be located in tissue of an atria or a ventricle. Unwanted signals are conducted elsewhere through heart tissue where they can initiate or continue arrhythmia.
Procedures for treating arrhythmia include surgically disrupting the origin of the signals causing the arrhythmia, as well as disrupting the conducting pathway for such signals. More recently, it has been found that by mapping the electrical properties of the endocardium and the heart volume, and selectively ablating cardiac tissue by application of energy, it is possible to cease or modify the propagation of unwanted electrical signals from one portion of the heart to another. The ablation process destroys the unwanted electrical pathways by formation of non-conducting lesions.
In this two-step procedure, which includes mapping followed by ablation, electrical activity at points in the heart is typically sensed and measured by advancing a catheter containing one or more electrical sensors into the heart and acquiring data at multiple points. These data are then utilized to select the target areas at which ablation is to be performed.
For greater mapping resolution, it is desirable for a mapping catheter to provide high-density signal maps through the use of several electrodes sensing electrical activity of tissue in an area on the order of a square centimeter. For mapping within an atria or a ventricle (for example, an apex of a ventricle), it is desirable for a catheter to collect larger amounts of data signals within shorter time spans. It is also desirable for such a catheter to be adaptable to different tissue surfaces, for example, flat, curved, irregular or nonplanar surface tissue and be collapsible for atraumatic advancement and withdrawal through a patient’s vasculature. It is also desirable to produce a catheter having increased electrode density and improved maneuverability within the heart of a patient. Accordingly, it may be advantageous to provide a shortened length end effector that is more maneuverable within a heart of a patient and has a higher density of electrodes. It may also be advantageous to provide a shortened length end effector that may include equidistantly spaced bipoles by bypassing every other electrode along a linear direction.
Various embodiments described herein allow high density mapping and/or ablation of tissue surface in the heart, including an atria or a ventricle, by virtue of a catheter for electrophysiology applications. The catheter may include a tubular member and an end effector. The tubular member may include a proximal portion and a distal portion defining a longitudinal axis. The tubular member may be configured to be manipulated at the proximal portion to position the distal portion into a heart of a patient. The distal portion may include a cross-section disposed about the longitudinal axis which intersects a first and second orthogonal plane that extend along the longitudinal axis. The cross section of the distal portion may include a first opening intersecting the first orthogonal plane and the second orthogonal plane and extending along the longitudinal axis, and six apertures disposed circumferentially about the first opening. Each of the six apertures may be configured to receive a spine. The end effector may be coupled to the distal portion. The end effector may include a first, second, and third loop members. Each of the loop members may include two spines and a connector that connects the two spines. The first, second, and third loop members may be configured such that each connector of the first, second, and third loop members may overlap at a distal vertex. The end effector may be configured to be delivered through vasculature in a collapsed configuration and expand in the heart to a deployed configuration such that in the deployed configuration the loop members are approximately planar.
In another embodiment, an end effector for use with a for electrophysiology applications is disclosed. The end effector may have a distal end and a proximal end. The distal end may be configured to be delivered through vasculature in a collapsed configuration and expand in the heart to a deployed configuration. The end effector may include a plurality of electrodes disposed on a plurality of equidistantly spaced spine members parallel to a longitudinal axis. The plurality of electrodes may be arranged in a grid. The plurality of equidistantly spaced spine members may form columns of the grid such that within each respective column, the plurality of electrodes may be spaced from an immediately adjacent electrode by a first gap length. The plurality of electrodes may form rows of the grid across the plurality of spine members, such that within each respective row, the plurality of electrodes may be spaced from an immediately adjacent electrode by a second gap length that measures approximately twice the first gap length.
In another embodiment, a method of use of a catheter for high density mapping and/or ablation of tissue surface in the heart is disclosed. The example method can include one or more of the following steps presented in no particular order. The method may include moving a distal portion of an elongated shaft of an end effector extending distally from the distal portion through a catheter into a heart. The elongated shaft may define a longitudinal axis and the end effector may include a plurality of electrodes disposed on a plurality of equidistantly spaced spine members parallel to the longitudinal axis. The plurality of electrodes may be arranged in a grid, and the plurality of electrodes may form rows of the grid. The method may include moving the end effector from a distal end of the catheter by manipulation of a proximal portion of the elongated shaft. The method may include contacting the plurality of electrodes carried by the end effector to heart tissue by manipulation of the proximal portion of the elongated shaft. The method may include activating one or more first electrode bipoles disposed on at least one spine member. The one or more first electrode bipoles may include two electrodes having at least a third electrode positioned between the two electrodes. The method may include receiving, while the plurality of electrodes are in contact with the heart tissue, electrical potentials from the one or more first electrode bipoles.
According to some embodiments, the method may further include deflecting the end effector at an angle relative to the longitudinal axis to contact the one or more first electrode bipoles and one or more second electrode bipoles to the heart tissue, activating one or more second electrode bipoles disposed orthogonally to the longitudinal axis along a respective row of the grid, and receiving, while the plurality of electrodes are in contact with the cardiovascular tissue, electrical potentials from the cardiovascular tissue via the one or more second electrode bipoles.
In any of the embodiments described earlier, the following features can be combined in various permutations with the embodiments as well as with each other. The two spines of each loop members may extend along the longitudinal axis, and each of the spines may include a plurality of electrodes that have at least a first electrode, a second electrode, and a third electrode disposed thereon. Each electrode may be spaced from an immediately adjacent electrode on a respective spine member by a first gap length. The first electrode of a respective spine member and the third electrode of a respective spine member may form a first bipole. Each respective electrode of a first spine may be spaced from a corresponding electrode of a second spine by a second gap length that measures approximately twice the first gap length. Each electrode of the first spine may form second bipoles with the corresponding electrode of the second spine. The two spines of the first loop member may be attached to non-adjacent apertures of the cross-section of the distal portion. The two spines of the second loop member may be attached to immediately adjacent apertures, and the two spines of the third loop members may be attached to non-adjacent apertures of the cross-section such that the first loop member and the third loop member do not intersect the second loop member. The first loop member and the third loop member may be considered outer loops and the second loop member may be considered an inner loop such that the outer loops intersect one another along the longitudinal axis and do not intersect the inner loop along the longitudinal axis. Four apertures may be disposed on one side of the second orthogonal plane with three apertures disposed on a first side of the first orthogonal plane, and three apertures disposed on a second side of the first orthogonal plane. The second loop member may be positioned on one side of the second orthogonal plane. The first loop member may lie on a first plane, the second loop member may lie on a second plane, and the third loop member may lie on a third plane, the first, second, and third planes intersecting each other. Each spine may be configured such that in the deployed configuration each spine is approximately parallel to each other such that the plurality of electrodes are positioned to define an electrode grid. Each respective electrode of the first spine may be linearly spaced along the first spine member and form respective overlapping electrode pairs. The first gap length may be between immediately adjacent electrodes measured from a center of each of the immediately adjacent electrodes. Each spine may include a plurality of spine segments each having a length equal to the first gap length less a length of a respective electrode. Each spine member may include eight electrodes. Each of the electrodes may have an electrode length measuring from approximately 100 microns to approximately 750 microns. The first gap length may include a length selected from approximately 1 millimeter, approximately 1.2 millimeters, and approximately 2.4 millimeters. The plurality of electrodes may be configured to receive electrical potentials from the heart when the end effector is in the deployed configuration. The plurality of electrodes may be configured to ablate heart tissue when the end effector is in the deployed configuration.
The following description of certain examples of the invention should not be used to limit the scope of the present invention. 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. Other examples, features, aspects, embodiments, and advantages of the invention will become apparent to those skilled in the pertinent art from the following description, which is by way of illustration, one of the best modes contemplated for carrying out the invention. As will be realized, the invention is capable of other different or equivalent aspects, all without departing from the invention. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not restrictive.
Any one or more of the teachings, expressions, versions, examples, etc. described herein may be combined with any one or more of the other teachings, expressions, versions, examples, etc. that are described herein. The following-described teachings, expressions, versions, examples, etc. should therefore not be viewed in isolation relative to each other. Various suitable ways in which the teachings herein may be combined will be readily apparent to those skilled in the pertinent art in view of the teachings herein. Such modifications and variations are intended to be included within the scope of the claims.
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 ±10% of the recited value, e.g. “about 90%” may refer to the range of values from 81% to 99%.
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 used 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 structure or system is generally illustrated as a substantially right cylindrical structure. However, the tubular system may have a tapered or curved outer surface without departing from the scope of the present invention.
The elongated shaft 9 has a proximal portion 12 in the shape of an elongated catheter body, an intermediate deflection section 14, and distal portion 14A. The deflection control handle 16 is attached to the proximal end of the catheter body 12. The distal portion 14A of the shaft is coupled to the end effector 100 via a connector tubing 46. The elongated shaft 9 forms a tubular catheter body sized and otherwise configured to traverse vasculature. The end effector 100 has a plurality of loop members 1, 2, 3 that overlap at a common distal vertex 5 and are joined at the distal vertex 5 with a mechanical linkage 50, as shown in
When the device is unconstrained and aligned, the proximal portion 12, intermediate section 14, distal portion 14A, and end effector 100 are generally aligned along a longitudinal axis L-L, as shown in
The useful length of the elongated shaft 9, i.e., that portion of the apparatus 10 that can be inserted into the body excluding the end effector, can vary as desired. Preferably the useful length ranges from about 110 cm to about 120 cm. The length of the intermediate section 14 is a relatively smaller portion of the useful length, and preferably ranges from about 3.5 cm to about 10 cm, more preferably from about 5 cm to about 6.5 cm.
Catheter body proximal portion 12 can be attached to the intermediate section 14 as shown and described in
As shown in
As shown in
The end effector 100 can be collapsed (compressed toward the longitudinal axis L-L) to fit within a guiding sheath or catheter (not illustrated). The shaft 9 can be pushed distally to move the end effector 100 distally through the guiding sheath. The end effector 100 can be moved to exit a distal end of the guiding sheath via manipulation of the shaft 9 and/or control handle 16. An example of a suitable guiding sheath for this purpose is the Preface Braided Guiding Sheath, commercially available from Biosense Webster, Inc. (Irvine, California, USA).
The end effector 100 has first, second and third loop members 1, 2, and 3. Each loop member 1, 2, 3 has two spines 1A, 1B, 2A, 2B, 3A, 3B and a connector 1C, 2C, 3C that connects the two spines of the respective loop member 1, 2, 3. Spines 1A, 1B of a first loop member 1 are connected by a first connector 1C; spines 2A, 2B of a second loop member 2 are connected by a second connector 2C; and spines 3A, 3B of a third loop member 3 are connected by a third connector 3C.
For each loop member 1, 2, 3 the spines 1A, 1B, 2A, 2B, 3A, 3B in the respective pair of spines can be substantially parallel to each other along a majority of their respective lengths when the end effector 100 is expanded in an unconstrained configuration as illustrated in
Each spine 1A, 1B, 2A, 2B, 3A or 3B can have a length ranging between about 5 and 50 mm, preferably about 10 and 35 mm, and more preferably about 28 mm. The parallel portions of each spine 1A, 1B, 2A, 2B, 3A, 3B can be spaced apart from each other by a distance ranging between about 1 mm and 20 mm, preferably between 2 mm and 10 mm, and more preferably about 4 mm. Each spine 1A, 1A, 1B, 2A, 2B, 3A, 3B preferably carries at least eight electrodes per spine member. The end effector preferably includes six spines as illustrated. With eight electrodes on six spines, the end effector 100 includes forty-eight electrodes.
A distal electrode 38D and a proximal electrode 38P are positioned near the distal portion 14A of the shaft 9. The electrodes 38D and 38P can be configured to cooperate (e.g. by masking of a portion of one electrode and masking a different portion on the other electrode) to define a referential electrode (an electrode that does not contact tissues). One or more impedance sensing electrodes 38R can be configured to allow for location sensing via impedance location sensing technique, as described in U.S. Pat. Nos. 5,944,022; 5,983,126; and 6,445,864, which are incorporated by reference and attached to the Appendix of priority application U.S. 63/279,747.
With this arrangement of apertures 202, 204, 206, 208, 210 and 212, loop members 1, 2 and 3 are arrayed in a non-coplanar unconstrained arrangement, shown in the sectional view of
As illustrated in
Proximal segments 1D, 2D, 3D, 1E, 2E, 3E of the loop members 1, 2, 3 can be bent such that at least a portion of each of the proximal segments curves away from the surface S.
When the majority of each spine 1A, 2A, 3A, 1B, 2B, 3B is pressed to the surface S, at least some of the electrodes 37 on each spine can be in contact with the surface S. In some examples, every electrode 37 on each spine can be in contact with the surface S.
When the majority of each spine 1A, 2A, 3A, 1B, 2B, 3B is pressed to the surface S, the majority of each respective length of each loop member can become contiguous to the surface S, where the respective length of each loop member includes the length of the respective loop member’s spines 1A, 2A, 3A, 1B, 2B, 3B, connectors 1C, 2C, 3C, and proximal segments 1D, 2D, 3D, 1E, 2E, 3E (distal to the connector tubing 46).
Additionally, or alternatively, the electrodes 37 need not completely circumscribe the respective loop 1, 2, 3; in which case the electrodes 37 can have a rectangular shape that is rectilinear or arced having a width W such that the electrode area Ae is a produce of the electrode length L and width W, the width being the arc length when the rectangular shape is arced. In examples where the electrode pair configurations are in shapes other than rectilinear, rectangular, or cylindrical, a conversion factor CF may be used to determine the appropriate gap distance between the electrodes based on the known area of either one of the pair of electrodes. The conversion factor CF may range from about 2 to 0.1 in the inverse of the same root dimensional unit as the planar area of an electrode. In one example, where the planar area of one electrode is about 0.08 squared-mm, the smallest gap distance Lg1 along the longitudinal axis extending through both electrodes can be determined by applying the conversion factor CF (in the inverse of the same root dimensional unit of the area or mm) to arrive at a gap distance Lg1 of about 100 microns. In another example where the area of one electrode is 0.24 squared-mm, the conversion factor CF (in the inverse of the same root dimensional unit or mm-1) can be 1.25 mm-1 or less, giving the range of the smallest gap distance Lg1 from about 300 microns to about 24 microns. Regardless of the shape of the electrodes, a preferred conversion factor CF is about 0.8 (in the inverse of the same root dimensional unit for the electrode area).
The guidance and drive system 110 can include a console 112 and a display 118. The console 112 can include a first driver module 114 and a second driver module 116. The first driver module 114 can be coupled with the apparatus via a cable 130. In some variations, the first driver module 114 is operable to receive EP mapping signals obtained via electrodes 37 of end effector 100. The console 112 can include a processor (not shown) that processes such EP mapping signals and thereby provides EP mapping. In addition, or in the alternative, the first driver module 114 may be operable to provide RF power to the electrodes 37 of end effector 100 to thereby ablate tissue. In some versions, the first driver module 114 is also operable to receive position indicative signals from a position sensor in end effector 100. In such versions, the processor of console 112 is also operable to process the position indicative signals from the position sensor to thereby determine the position of the end effector 100 within the patient PA.
The guidance and drive system 110 can further include non-transitory computer readable medium with instructions thereon to cause the drive system 110 to perform functionality described herein and/or as are known related to use of similar equipment. In some examples, the non-transitory computer readable memory can be in communication with the first driver module 114 (e.g. by virtue of being in communication with a processor of the first driver module 114 and/or the processor of the console 112). The non-transitory computer readable medium can include instructions thereon that when executed by the first driver module 114 cause the first driver module 114 to receive EP mapping signals from the spine electrodes 37 and a reference signal from one of distal electrode 38D, proximal electrode 38P, or a combinations of both.
The second driver module 116 is coupled with field generators 120 via a cable 122. The second driver module 116 is operable to activate field generators 120 to generate an alternating magnetic field around the heart H of the patient PA. For instance, the field generators 120 may include coils that generate alternating magnetic fields in a predetermined working volume that contains the heart H.
Some versions of the apparatus 10 include a position sense near or within the end effector 100 that is operable to generate signals that are indicative of the position and orientation of end effector 100 within the patient PA. Each position sensor may include a wire coil or a plurality of wire coils (e.g., three orthogonal coils) that are configured to generate electrical signals in response to the presence of an alternating electromagnetic field generated by field generators 120. Other components and techniques that may be used to generate real-time position data associated with end effector 100 may include wireless triangulation, acoustic tracking, optical tracking, inertial tracking, and the like. By way of example only, position sensing may be provided in accordance with at least some of the teachings of U.S. Pat. No. 9,480,416, which is incorporated herein by reference and attached to the Appendix of priority application U.S. 63/279,747. Alternatively, apparatus 10 may lack a position sensor near the end effector 100.
The display 118 is coupled with the processor of console 112 and is operable to render images of patient anatomy. Such images may be based on a set of preoperatively or intraoperatively obtained images (e.g., a CT or MRI scan, 3-D map, etc.). The views of patient anatomy provided through the display 118 may also change dynamically based on signals from the position sensor near the end effector 100.
The processor of the console 112 may also drive the display 118 to superimpose the current location of end effector 100 on the images of the patient’s anatomy, such as by superimposing an illuminated dot, a crosshair, a graphical representation of end effector 100, or some other form of visual indication.
The fluid source 142 can include a bag containing saline or some other suitable irrigation fluid. The conduit 140 can include a flexible tube that is further coupled with a pump 144, which is operable to selectively drive fluid from the fluid source 142 to the irrigation tube 15 of the apparatus 10. In some variations, such as including a reference electrode 38D and/or 38P as configured in
In step 910, the method may include moving the end effector from a distal end of the catheter via manipulation of a proximal portion of the elongated shaft (e.g., control handle 16, as shown in
In optional step 925, the method may include activating a first electrode bipole disposed on a first spine member and a second electrode bipole (e.g., lateral bipole 37B) disposed orthogonally to the longitudinal axis along a respective row of the grid.
In step 930, the method may include receiving, while the plurality of electrodes are in contact with the heart tissue, electrical potentials via the one or more first electrode bipoles (e.g., longitudinal bipoles 37A). In optional step 935 the method may include receiving, while the plurality of electrodes are in contact with the heart tissue, electrical potentials via the one or more second electrode bipoles (e.g., lateral bipoles 37B).
The descriptions contained herein are examples of embodiments of the invention and are not intended in any way to limit the scope of the invention. As described herein, the invention contemplates many variations and modifications of system components, including alternative combinations of components illustrated in separate figures, alternative materials, alternative component geometries, and alternative component placement. Modifications and variations apparent to those having skilled in the pertinent art according to the teachings of this disclosure are intended to be within the scope of the claims which follow.
This application claims the benefit of priority to prior filed U.S. Provisional Pat. Application No. 63/279,747 filed on Nov. 16, 2021, which is hereby incorporated by reference as if set forth in full herein.
| Number | Date | Country | |
|---|---|---|---|
| 63279747 | Nov 2021 | US |
