Catheter with staggered electrode ridge assembly

Abstract

The present invention discloses an electrophysiology catheter having a distal electrode assembly having a covered ridge carrying a plurality of microelectrodes. The positions of the microelectrodes on each ridge are staggered relative to the microelectrodes on adjacent ridges to minimize the risk of electrodes on adjacent ridges touching each other during use of the catheter. The staggered electrode configuration provides a larger effective contact surface for the distal electrode assembly because the effective concentric electrode array is increased or at least doubled.

Description

Technical Field

[0001] The present invention relates to an electrophysiology catheter, and in particular, to a cardiac electrophysiology catheter having an electrode configuration that provides more accurate and independent sensing of graded signals. Background Art

[0002] Electrode catheters have been common in medical practice for many years. They are used to stimulate and map electrical activity in the heart, as well as to ablate sites of abnormal electrical activity.

[0003] When used, the electrode catheter is inserted into a major vein or artery (e.g., the femoral artery) and then introduced into the chamber of the heart of interest. Once the catheter is positioned in the heart, the location of abnormal electrical activity in the heart is located.

[0004] One localization technique involves an electrophysiological mapping procedure, whereby electrical signals emanating from conductive intracardiac tissue are systematically monitored and a map is formed from these signals. By analyzing the map, the physician can identify interfering electrical pathways. The conventional method for mapping electrical signals from conductive cardiac tissue is to introduce an electrophysiological catheter (electrode catheter) percutaneously, which has mapping electrodes mounted on its distal end. The catheter is manipulated to place these electrodes in contact with the endocardium. By monitoring the electrical signals at the endocardium, the site of abnormal conductive tissue causing the arrhythmia can be pinpointed.

[0005] For sensing via catheter-mounted ring electrodes, leads transmitting signals from the ring electrodes are electrically connected to a suitable connector in the distal end of the catheter control handle, which is electrically connected to an ECG monitoring system and / or a suitable 3D electrophysiological (EP) mapping system, such as CARTO, CARTO XP, or CARTO 3 available from Biosense Webster, Inc. (Irwindale, California).

[0006] Relative to far-field signals, smaller and more closely spaced electrode pairs allow for more accurate detection of near-field potentials, which may be very important when attempting to treat a specific area of ​​the heart. For example, the near-field pulmonary vein potential is a very small signal, while the atrium, which is located very close to the pulmonary vein, provides a much larger signal. Therefore, even when the catheter is placed in the pulmonary vein region, it may be difficult for an electrophysiologist to determine whether the signal is a small near potential (from the pulmonary vein) or a larger, more distant potential (from the atrium). Smaller and closely spaced bipolars allow physicians to more accurately remove far-field signals and obtain more accurate readings of electrical activity in local tissues. Therefore, by having smaller and closely spaced electrodes, it is possible to accurately target the position of myocardial tissue with pulmonary vein potentials, and therefore allow clinicians to deliver treatment to specific tissues. In addition, smaller and closely spaced electrodes allow physicians to determine the precise anatomical position of the heart gate by electrical signals.

[0007] Increasing electrode density (e.g., by increasing the number of electrodes carried on a catheter) also improves detection accuracy. However, the more electrodes carried on a catheter, and particularly the higher the electrode density, the greater the risk of electrode contact and short circuiting. In addition, it is always desirable to improve electrode tissue contact with highly flexible electrode assembly structures that can reliably make contact, but in a manner that enables the electrode-carrying structure to operate in a controllable and predictable manner without puncturing or damaging the tissue. As the materials used to construct these structures become more flexible and sophisticated, the risk of deformation, particularly elongation, of smaller annular electrodes and their supporting structures during catheter assembly increases. In addition, as electrode assembly structures become more sophisticated, the risk of component separation, kinking, and entanglement increases.

[0008] It has also been observed that signal acquisition by the electrodes is adversely affected when the electrodes touch or come into contact with each other. During mapping, contact and collision may occur when the operator manipulates the distal electrode assembly of the catheter, especially when the operator "sweeps" the assembly along the tissue surface. Contact and collision between electrodes may produce artifacts that adversely affect the quality of the ECG signal and map generation.

[0009] Therefore, there is a need for an electrophysiology catheter with closely spaced microelectrodes to achieve a high electrode density. There is also a need for an electrophysiology catheter with electrode-carrying structures that are finely constructed to provide the desired flexibility, but whose movement is predictable when in tissue contact. There is also a need for an electrophysiology catheter that minimizes the risk of electrode touching and shorting. Summary of the invention

[0010] The present invention relates to an electrophysiology catheter having a distal electrode assembly that carries very small and closely spaced microelectrodes on a plurality of dispersed ridges that can be flexibly extended over a tissue surface area so as to detect signals at multiple locations simultaneously and simultaneously minimize the detection of unwanted noise (including far-field signals). The distal electrode assembly is configured to conform to different anatomical structures of tissue in the atrial chamber of the heart. The ridges have curved sections or curved sections with straight sections so as to have a wide range of adaptability to different tissue surfaces while providing mechanical advantages in different sections to improve flexibility and rigidity, thereby facilitating better contact with the tissue. Each ridge has a generally tapered configuration from its proximal end to its distal end for providing a stronger, more rigid proximal base and a more flexible distal end so as to improve flexibility characteristics while minimizing the risk of ridge touching or tangling.

[0011] In some embodiments, an electrophysiology catheter has an elongated body and a distal electrode assembly having a proximal shaft, a plurality of spines emanating from the proximal shaft, and a plurality of non-conductive spine covers, each spine cover surrounding a respective spine, each spine cover having a plurality of tensile members embedded in a sidewall of the cover.

[0012] In some embodiments, the tensile member extends in a longitudinal direction.

[0013] In some embodiments, the tensile member has a portion that extends in the longitudinal direction.

[0014] In some embodiments, the tensile member comprises a wire.

[0015] In some embodiments, the tensile member comprises fibers.

[0016] In some embodiments, an electrophysiology catheter has an elongated body and a distal electrode assembly. The distal electrode assembly has a proximal rod and a plurality of ridges, each ridge having an enlarged distal portion having a through hole. The distal electrode assembly also has a plurality of non-conductive ridge covers, each ridge cover surrounding a corresponding ridge. The distal electrode assembly also has a cap cover encapsulating the enlarged distal portion, the cap cover having a portion extending through the through hole.

[0017] In some embodiments, an electrophysiology catheter has an elongated body and a distal electrode assembly. The distal electrode assembly has a proximal shaft and a plurality of ridges of at least eight, each ridge having a first segment and a linear segment, the first segment having a first preformed curvature defined by a first radius. The distal electrode assembly also has a plurality of non-conductive ridge covers and a plurality of microelectrodes, wherein each ridge has at least one microelectrode thereon.

[0018] In some embodiments, each spine includes a second segment having a second preformed curvature defined by a second radius different from the first radius, the second segment having the second preformed curvature being located distal to the first segment having the first preformed curvature.

[0019] In some embodiments, the first radius is smaller than the second radius.

[0020] In some embodiments, the second pre-form curvature is opposite to the first pre-form curvature.

[0021] In some embodiments, the second segment having the second preformed curvature is located distal to the first segment having the first preformed curvature.

[0022] In some embodiments, in some embodiments, the linear segment is located between a first segment having a first pre-formed curvature and a second segment having a second pre-formed curvature.

[0023] In some embodiments, the second segment having the linear segment is located distal to the second segment having the second preformed curvature.

[0024] In some embodiments, each covered ridge has an outer circumference of less than 3 French.

[0025] In some embodiments, the outer circumference is about 2.6 French.

[0026] In some embodiments, an electrophysiology catheter has an elongated body and a distal electrode assembly. The distal electrode assembly has a proximal portion and a plurality of ridges, each ridge having a linear taper with a wider proximal end and a narrower distal end. The distal electrode assembly also has a plurality of non-conductive ridge covers, each non-conductive ridge cover surrounding a corresponding ridge.

[0027] In some embodiments, the linear taper is continuous.

[0028] In some embodiments, the linear taper is discontinuous.

[0029] In some embodiments, the discontinuous linear taper includes a concave portion having a width that is less than a width of the more proximal stem and a width of the more distal portion.

[0030] In some embodiments, the spine has a hinge along a lateral edge configured for in-plane deflection of the spine.

[0031] In some embodiments, the electrophysiology catheter has an elongated body and a distal electrode assembly. The distal electrode assembly has a proximal rod, a plurality of ridges of at least eight, each ridge having a linear taper with a wider proximal end and a narrower distal end. The distal electrode assembly also has a plurality of non-conductive ridge covers, each of which surrounds a corresponding ridge. The distal electrode assembly also has a plurality of microelectrodes, the plurality being at least about 48, each microelectrode having a length of about 480 μm.

[0032] In some embodiments, the microelectrodes on each ridge are separated by a distance ranging between about 1 mm and 3 mm as measured between the leading edges of the microelectrodes.

[0033] In some embodiments, the distance is about 2 mm.

[0034] In some embodiments, the microelectrodes on each ridge are arranged as bipolar pairs, wherein the leading edges of the microelectrodes within a pair are separated by a first distance in a range between approximately 1 mm and 3 mm, and wherein the leading edges of the leading microelectrodes between multiple pairs are separated by a second distance in a range between 1 mm and 6 mm.

[0035] In some embodiments, the first distance is about 2 mm and the second distance is about 6 mm.

[0036] In some embodiments, the plurality of microelectrodes is equal to about 64.

[0037] In some embodiments, the plurality of microelectrodes equals approximately 72 microelectrodes.

[0038] In some embodiments, the first ring electrode is carried on a proximal shaft of the distal electrode assembly and the second ring electrode and the third ring electrode are carried on a distal portion of the elongated body.

[0039] In some embodiments, the electrophysiology catheter has an elongated body and a distal electrode assembly. The distal electrode assembly has a proximal rod that defines a circumference around a longitudinal axis. The distal electrode assembly also has a plurality of ridges emanating from the proximal rod and diverging at its distal end, the plurality of ridges alternating between a first ridge and a second ridge around the circumference of the rod. The distal electrode assembly also has a plurality of non-conductive ridge covers and a plurality of microelectrodes, each ridge cover surrounding a corresponding ridge, the plurality of microelectrodes having a staggered configuration about a first ridge and a second ridge, wherein the most proximal microelectrode on each first ridge is positioned at a greater distance from the proximal rod, and the most proximal electrode on each second ridge is positioned at a lesser distance from the proximal rod.

[0040] The staggered electrode configuration provides a larger effective contact surface for the distal electrode assembly because the effective concentric electrode array is increased or at least doubled.

[0041] In some embodiments, the distal electrode assembly includes at least four first ridges and four second ridges, and each ridge carries eight microelectrodes.

[0042] In some embodiments, each microelectrode has a length of about 480 μm.

[0043] In some embodiments, the microelectrodes on each ridge are separated by a distance ranging between about 1 mm and 3 mm as measured between the leading edges of the microelectrodes.

[0044] In some embodiments, the distance is about 2 mm.

[0045] In some embodiments, the microelectrodes on each ridge are arranged as bipolar pairs, wherein the leading edges of the microelectrodes within a pair are separated by a first distance in a range between approximately 1 mm and 3 mm, and wherein the leading edges of the leading microelectrodes between multiple pairs are separated by a second distance in a range between 1 mm and 6 mm.

[0046] In some embodiments, the first distance is about 2 mm and the second distance is about 6 mm.

[0047] In some embodiments, the electrophysiology catheter has an elongated body and a distal electrode assembly. The distal electrode assembly has a support structure having a proximal rod having a side wall having an inner surface defining a lumen, the side wall having an opening. The support structure also has a plurality of ridges emanating from the proximal rod and diverging at its distal end, and a plurality of non-conductive covers, each of which surrounds a corresponding ridge. The distal electrode assembly also has a plurality of microelectrodes on each ridge, and a housing insert received in the lumen of the rod, the housing insert having an outer surface, with a gap retained between the outer surface and the inner surface of the rod. The adhesive fills the gap between the inner surface of the proximal rod and the outer surface of the housing insert, and the adhesive has a portion that passes through the opening in the side wall of the proximal rod.

[0048] In some embodiments, the housing insert has a lumen having an elongated kidney bean-shaped configuration in cross-section.

[0049] In some embodiments, the housing insert has a lumen having a C-shaped configuration in cross-section.

[0050] In some embodiments, the opening in the proximal rod provides visual access to the lumen of the rod for inspection of components extending therethrough during assembly. In addition, an adhesive that fills the void is injected or otherwise applied through the opening. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] These and other features and advantages of the present invention will be better understood by referring to the following detailed description when considered in conjunction with the accompanying drawings. It should be understood that selected structures and features are not shown in certain drawings in order to provide a better view of the remaining structures and features.

[0052] Figure 1 is a perspective view of a catheter of the present invention according to one embodiment.

[0053] Figure 2 for Figure 1 An end cross-sectional view of a catheter body of a catheter.

[0054] Figure 3 for Figure 1 End cross-sectional view of the deflection segment of a catheter.

[0055] Figure 4 is a perspective view of a one-piece support member according to one embodiment.

[0056] Figure 5A is a side view of a one-piece support member according to one embodiment.

[0057] Figure 5B for Figure 5A Detailed view of the integrated support member.

[0058] Figure 5C Intercepted along CC Figure 5A End cross-sectional view of an integral support member.

[0059] Figure 5D for Figure 5A Detailed view of the enlarged distal portion of the ridge.

[0060] Figure 5E for Figure 5A Detailed view of a cross-sectional view of the end of a ridge.

[0061] Fig. 6A is a side view of a one-piece support member according to one embodiment.

[0062] Figure 6B for Fig. 6A Detailed view of the integrated support member.

[0063] Figure 6C for Figure 6B Detailed view of the distal portion of the ridge.

[0064] Fig.6D for Fig. 6A Detailed view of the enlarged distal portion of the ridge.

[0065] Fig. 6E It was intercepted along line EE Figure 6B End cross-sectional view of an integral support member.

[0066] Fig. 6F yes Figure 6B Detailed view of an end cross-sectional view of the proximal portion of the spine.

[0067] Figure 6G yes Figure 6B Detailed view of an end cross-sectional view of the distal portion of the spine.

[0068] Fig. 7A is a side view of a one-piece support member according to one embodiment.

[0069] Figure 7B for Fig. 7A A side view of a one-piece support member in contact with tissue.

[0070] Fig. 8A is a side view of a one-piece support member according to another embodiment.

[0071] Figure 8B for Fig. 8A A side view of a one-piece support member in contact with tissue.

[0072] Fig.9A is a side view of a one-piece support member according to another embodiment.

[0073] Fig. 9B for Fig.9A A side view of a one-piece support member in contact with tissue.

[0074] Fig.10 is a side view of a unitary support member according to one embodiment, which is illustrated to show various parameters.

[0075] Fig.11A is a top plan view of a spine having a hinge structure according to one embodiment.

[0076] Fig. 11B is a top plan view of a spine having a hinge structure according to another embodiment.

[0077] Fig. 12A is a side view of a covered ridge according to one embodiment.

[0078] Fig. 12B is a side view of a covered ridge according to another embodiment.

[0079] Fig.13 is a front view of a distal electrode assembly according to one embodiment.

[0080] Fig.14A is a side cross-sectional view of a junction between a deflection segment and a distal electrode assembly according to one embodiment.

[0081] Fig. 14B for Fig.14A End cross-sectional view of the housing insert.

[0082] Fig.15A is a side cross-sectional view of a junction between a deflection segment and a distal electrode assembly according to another embodiment.

[0083] Fig. 15B for Fig.15A End cross-sectional view of the housing insert.

[0084] Fig.16 is a side perspective view of a covered spine with a reinforced tensile member according to one embodiment.

[0085] Fig.17 is a detailed side cross-sectional view of a portion of a joint having a reinforced tensile member according to one embodiment.

[0086] Fig.18 is an end cross-sectional view of a shell insert having a reinforcing tensile member therethrough according to one embodiment.

[0087] Fig.19 is an end cross-sectional view of a deflection segment having a reinforced tensile member therethrough according to one embodiment.

[0088] Fig. 20 is an end cross-sectional view of a catheter body having a reinforcing tensile member extending therethrough according to one embodiment.

[0089] Fig.21 Schematic diagram of a heart and placement of a catheter of the present invention for tissue contact according to various embodiments.

[0090] Fig. 22 is a schematic diagram of a distal electrode assembly in contact with tissue in a pulmonary vein according to one embodiment.

[0091] Fig.23 is a schematic diagram of a distal electrode assembly in contact with tissue of a side wall of a heart according to one embodiment.

[0092] Fig.24 is a schematic diagram of a distal electrode assembly in contact with tissue of the inferior wall or apex of the heart according to one embodiment.

[0093] Fig.25 Taken along line AA Fig.15A An end cross-sectional view of the distal end of the distal electrode assembly.

[0094] Fig.26 is a schematic diagram of the concentricity of a distal electrode assembly according to one embodiment.

[0095] Fig. 27 is a schematic diagram of the concentricity of a distal electrode assembly according to another embodiment. DETAILED DESCRIPTION

[0096] See also Figure 1 In some embodiments of the present invention, the catheter 10 includes a catheter body 12, an intermediate deflection section 14, a distal electrode assembly 15, and a control handle 16 located proximal to the catheter body 12. The distal electrode assembly 15 includes a plurality of spines 17, each supporting a plurality of microelectrodes 18.

[0097] In some embodiments, the catheter body 12 comprises an elongated tubular structure having a single axial lumen or central lumen 19, such as Figure 2 As shown. The catheter body 12 is flexible, i.e., bendable, but substantially incompressible along its length. The catheter body 12 may have any suitable configuration and may be made of any suitable material. A currently preferred configuration includes an outer wall 20 made of polyurethane or PEBAX. The outer wall 20 includes an embedded braided mesh made of high-strength steel, stainless steel, etc. to increase the torsional rigidity of the catheter body 12 so that when the control handle 16 is rotated, the deflection segment 14 of the catheter 10 rotates in a corresponding manner.

[0098] The outer diameter of the catheter body 12 is not a critical factor. Likewise, the thickness of the outer wall 20 is not a critical factor, but is thin enough so that the central lumen 19 can accommodate components, including, for example, one or more pull wires, electrode leads, irrigation tubes, and any other wires and / or cables. In some embodiments, the inner surface of the outer wall 20 is lined with a rigid tube 21, which can be made of any suitable material (such as polyimide or nylon). The rigid tube 21, together with the braided outer wall 20, provides improved torsional stability while minimizing the wall thickness of the catheter, thereby maximizing the diameter of the central lumen 19. As will be appreciated by those skilled in the art, the catheter body construction can be modified as needed. For example, the rigid tube can be removed.

[0099] In some embodiments, the intermediate deflection segment comprises a shorter segment of the tube 30, such as Figure 3 As shown, the shorter segment has multiple lumens 31. In some embodiments, the tube 30 is made of a suitable biocompatible material that is more flexible than the catheter body 12. Suitable materials for the tube 19 are braided polyurethane, i.e., polyurethane with an embedded mesh of braided high-strength steel, stainless steel, etc. The outer diameter of the deflection segment 14 is similar to the outer diameter of the catheter body 12. The number and size of the lumens are not critical factors and can vary depending on the specific application.

[0100] Various components extend through the catheter 10. In some embodiments, these components include a lead wire 22 for the distal electrode assembly 15, one or more puller wires 23A and 23B for deflecting the deflection segment 14, an electromagnetic position sensor 26 (see FIG. 1 ) housed at or near the distal end of the deflection segment 14, and a guide wire 23A and 23B for deflecting the deflection segment 14. Fig.14A and Fig.15A ) cable 24. In some embodiments, the catheter includes an irrigation tube 27 for delivering fluid to the distal end of the deflection segment 14. These components pass through the central lumen 19 of the catheter body 12, such as Figure 2 shown.

[0101] In the deflection section 14, different components pass through different lumens 31 of the tube 30, such as Figure 3 In some embodiments, the lead 22 passes through one or more lumens 31A, the first puller wire 23A passes through the lumen 31B, the cable 24 passes through the lumen 31C, the second puller wire 23B passes through the lumen 31D, and the irrigation tube 27 passes through the lumen 31E. Lumen 31B and lumen 31D are diametrically opposed to each other to provide bidirectional deflection of the intermediate deflection segment 14. Additional components can pass through additional lumens or share lumens with other aforementioned components as needed.

[0102] Distal to the deflection segment 14 is a distal electrode assembly 15, which includes Figure 4 The one-piece support member 40 shown. In some embodiments, the one-piece support member 40 includes a superelastic material with shape memory, that is, a superelastic material that can temporarily straighten or bend from its original shape when a force is applied, and can substantially return to its original shape when there is no force or the force is removed. One material suitable for the support member is a nickel / titanium alloy. Such alloys typically include about 55% nickel and 45% titanium, but may also include about 54% to about 57% nickel, with the remainder being titanium. The nickel / titanium alloy is nitinol, which has excellent shape memory as well as ductility, strength, corrosion resistance, resistivity, and temperature stability.

[0103] In some embodiments, the member 40 is constructed and formed from an elongated hollow cylindrical member that has, for example, portions cut (e.g., by laser cutting) or otherwise removed to form an elongated body of a proximal portion or stem 42 and a spine 17 that emanates longitudinally from the stem and spans outwardly from the stem. The stem 42 defines a lumen 43 therethrough for receiving a distal end portion 30D of the multi-lumen tube 30 of the deflection segment 14 (see Fig.14A ), as well as various components as further discussed below, which are housed in the rod 42 or extend through the tubular cavity 43.

[0104] Each ridge 17 of the member 40 has an enlarged distal portion 46, and each ridge has a wider proximal end and a narrower distal end. Figure 5A , Figure 5B , Figure 5C , Figure 5D and Figure 5E As shown, the spine is linearly tapered to achieve an "out-of-plane" flexibility that varies along its length (see Figure 5E In some embodiments, one or more ridges 17 have a proximal portion 17P having a uniform width W1, a distal portion 17D1 having a continuous linear taper defined by a taper line T1 (see FIG. Figure 5B ), and a more distal portion 17D2 having a uniform width W2 that is less than W1. The distal portion 17D1 has a continuously increasing flexibility so that when the distal portion 46 comes into contact with tissue, the ridges can adopt a predetermined form or curvature. The resulting ridges with a relatively more rigid proximal portion and a relatively more flexible distal portion help prevent the ridges from crossing and overlapping each other during use.

[0105] In some embodiments, one or more ridges 17 have a discontinuous linear taper between end 41 and end 46, such as Fig. 6A , Figure 6B , Figure 6C , Fig.6D , Fig. 6E , Fig. 6F and Figure 6G The discontinuous linear taper includes one or more narrower portions or concave portions 50 strategically positioned along the spine to interrupt the otherwise continuous linear taper defined by the taper T2 between the stem 42 and the enlarged distal portion 46. Each concave portion 50 has a width W (see Figure 6C ), the width W being less than the width WD of the more distal portion and also less than the width WP of the more proximal portion, wherein the width WD < the width WP. Thus, each concave portion 50 advantageously allows that region of the spine to have a different flexibility than the immediately adjacent (distal and proximal) portions 51 of the spine, and provides a degree of independent flexibility between the portions separated by the concave portions 50 (see Figure 6B ). Thus, when distal portion 46 comes into contact with tissue, the ridges are permitted to exhibit significantly greater flexibility, and therefore a tighter or sharper curvature, in the region of recessed portion 50 relative to ridged portion 51 .

[0106] In some embodiments, each ridge (between the distal end of the stem 42 and the distal end of the ridge) has a length in the range of between about 1.0 cm and 2.5 cm, or between about 1.50 cm and 2.0 cm, and a width in the range of between about 0.009 inches and 0.02 inches. In some embodiments, the recessed portion 50 has a length in the range of between about 10% and 20% of the length of the ridge, and a width W in the range of between about 50% and 80% of the proximal width, measured from the distal end of the stem 42, with the proximal leading edge of the recessed portion located at about 55% to 65% of the length of the ridge.

[0107] To further facilitate microelectrode contact with tissue along the entire length of the ridge, each ridge 17 has a pre-formed configuration or curvature, which is achieved by, for example, heating and molding the fixture. One or more ridges 17 have at least two different pre-formed curvatures C1 and C2, such as Fig. 7A As shown, the segment S1 with the preformed curvature C1 is defined by a radius R1, and the segment S2 with the preformed curvature C2 is defined by a radius R2, wherein the radius R1<R2 and the curvatures C1 and C2 are generally in opposite directions to each other, so that the spine of the integral support member 40 has a generally forward-facing concave surface similar to an open umbrella. Figure 7B As shown (only two spines are shown for clarity), when the distal ends of the spines come into contact with the exemplary surface SF, the preformed spines transform from their neutral configuration N (shown in phantom) to their adaptive or temporarily "deformed" configuration A, which may include a "crouched" profile with undulating regions that may better conform to the heart tissue (compared to their neutral configuration). Advantageously, the unitary support member 40 maintains its generally forward-facing concave configuration without turning inside out upon tissue contact (like an umbrella flipping upward in a strong wind).

[0108] In some embodiments, one or more ridges 17 have at least a curved section and a linear section. In some embodiments, one or more ridges have at least two different preformed curvatures along their length. For example, Fig. 8A As shown, one or more spines 17 have a first section SA, a second section SB and a third section SC, wherein the first section SA has a preformed curvature CA defined by a radius RA, the second section SB has a preformed curvature CB defined by a radius RB, and the third section SC is linear, wherein the radius RA < the radius RB. Figure 8BAs shown (only two ridges are shown for clarity), when the distal ends of the ridges come into contact with the exemplary surface SF, the preformed ridges transform from their neutral configuration N to their adaptive or temporarily "deformed" configuration A, which configuration A may include deeper concavities with convex areas that may be better adapted to cardiac tissue (compared to their neutral configuration).

[0109] As another example, Fig.9A As shown, one or more ridges 17D have a first segment SJ, a second segment SK, and a third segment SL, wherein the first segment SJ has a preformed curvature CJ defined by a radius RJ, the second segment SK is linear, and the third segment SL has a preformed curvature CL defined by a radius RL, wherein the radius RJ < the radius RL. Fig. 9B As shown (only two spines are shown for clarity), when the distal ends of the spines come into contact with the exemplary surface SF, the preformed spines transform from their neutral configuration N to their adaptive or temporarily "deformed" configuration A, which configuration A may include a lower profile (compared to their neutral configuration) that may be better suited to flatter areas of cardiac tissue.

[0110] refer to Fig.10 In some embodiments, the integral support member 40 and its spine 17 may be defined by a number of parameters, including, for example, the following parameters:

[0111] a = height of the second curvature, ranging between approximately 0.00 inches and 0.050 inches

[0112] b = distal length of the second curvature, ranging between approximately 0.302 inches and 0.694 inches

[0113] c = proximal length of the second curvature, ranging between approximately 0.00 inches and 0.302 inches

[0114] d = distance between the first curvature and the second curvature, ranging between about 0.00 inches and 0.170 inches

[0115] e = first radius of curvature, ranging between approximately 0.075 inches and 0.100 inches

[0116] f = length of the segment with uniform width, approximately 0.100 inches

[0117] g = concave depth, ranging between approximately 0.123 inches and 0.590 inches

[0118] Notably, in some embodiments of the unitary support member 40, the proximal (or first) preformed curvature is opposite to the distal (or second) preformed curvature, such that the spine 17 of the distal electrode assembly 15 can maintain its generally concave surface and remain facing forward without inverting upon tissue contact, while the highly flexible spine allows the assembly to have flexibility or "stretchability", which prevents the distal tip of the spine from piercing or otherwise causing damage to the tissue upon contact with the tissue and when the distal electrode assembly is pressed against the tissue surface to ensure contact with the tissue by each of the ridges 17. In addition, in some embodiments, the concave portion 50 can span between the proximal preformed curvature and the distal preformed curvature, such that each of the three portions of the spine (the proximal portion, the concave portion, and the distal portion) can behave differently in response to tissue contact and the associated pressure applied by the operator user of the catheter and have a degree of independence in flexibility relative to each other.

[0119] It should be understood that the aforementioned figures show exaggerated deformation and curvature of the ridges for ease of discussion and explanation, while actual deformation and curvature may be much more subtle and less acute.

[0120] In some embodiments, one or more spines 17 are also configured with hinges 90 for in-plane (side-to-side) deflection. Fig.11A and Fig. 11B As shown, the spine 17 can have a plurality of notches or grooves along opposing lateral edges, including an expandable groove 80 (e.g., in the form of a slit 81 and a circular opening 82) along one edge 85a and a compressible groove 83 (e.g., in the form of a slot 84 and a circular opening 82) along an opposing edge 85b, thereby forming a hinge 90 for more in-plane deflection along these edges. Fig.11A and Fig. 11B In the embodiment of the present invention, the edge 85b towards the ridge 17 has a unidirectional deflection. However, it should be understood that in the case where the compressible groove 83 is formed along both the edge 85a and the edge 85b, the ridge 17 has a bidirectional deflection towards either edge 85a or 85b. Suitable hinges are described in U.S. Patent No. 7,276,062, the entire contents of which are incorporated herein by reference.

[0121] like Fig. 12A and Fig. 12BAs shown, each spine 17 of the distal electrode assembly 15 is surrounded along its length by a non-conductive spine cover or tube 28. In some embodiments, the non-conductive spine cover 28 comprises a very soft and highly flexible biocompatible plastic, such as PEBAX or PELLATHANE, and the spine cover 28 is mounted on the spine and its length extends together with the spine between the shaft 42 and the enlarged distal portion 46. Suitable materials of construction for the spine cover 28 are soft and flexible enough so as not to generally interfere with the flexibility of the spine 17.

[0122] In some embodiments, each covered ridge 17 has a diameter D along its length of less than 3 French, preferably less than 2.7 French in diameter, and more preferably 2 French in diameter (eg, between about 0.025 and 0.035 inches in diameter).

[0123] Each spine 17 includes an atraumatic distal cover or cap 45 encapsulating an enlarged distal portion 46 (see Fig. 12A ). In some embodiments, the cover 45 includes a biocompatible adhesive or sealant, such as polyurethane, having a bulbous configuration to minimize damage to tissue when contacting or applying pressure against tissue. The construction of the cover 45 includes a bridge portion 63 of adhesive or sealant that passes through the through hole 47 in the enlarged distal portion 46 and advantageously forms a mechanical lock that secures the cover 45 to the distal portion 46 and minimizes the risk of the cover 45 separating from the enlarged distal portion 46.

[0124] Each ridge 17 carries a plurality of microelectrodes 18. The number and arrangement of the microelectrodes can vary depending on the intended use. In some embodiments, "plurality" is in the range between about 48 and 72, but it should be understood that "plurality" can be larger or smaller. In some embodiments, each microelectrode has a length L of less than 800 μm (e.g., in the range between about 600 μm and 300 μm, and, for example, measured to be about 480 μm, 460 μm, or about 450 μm). In some embodiments, the distal electrode assembly 15 has a length L greater than about 7.1 / cm 2 (For example, between about 7.2 / cm 2 and 12.6 / cm 2 In some embodiments, the distal electrode assembly 15 has an area coverage of greater than about 2.5 microelectrodes / cm 2 (e.g., between about 4 microelectrodes / cm 2 With 7 microelectrodes / cm 2 The microelectrode density is in the range between .

[0125] In some embodiments, the distal electrode assembly 15 has eight ridges, each ridge is about 1.5 cm in length and carries eight microelectrodes, for a total of 48 microelectrodes, the microelectrode of each ridge having a length of about 460 μm, wherein the assembly 15 has a density of about 7.1 / cm 2 The area coverage is about 7 microelectrodes / cm 2 The microelectrode density.

[0126] In some embodiments, the distal electrode assembly 15 has eight ridges, each ridge is about 2.0 cm in length and carries six microelectrodes, for a total of 48 microelectrodes, the microelectrode of each ridge having a length of about 460 μm, wherein the assembly 15 has a density of about 12.6 / cm 2 The area coverage is about 4 microelectrodes / cm 2 The microelectrode density.

[0127] The microelectrodes 18 on the ridge 17 can be arranged as a monopole or bipole with a variety of spacings between them, where the spacing is measured as the spacing between the respective leading edges of adjacent microelectrodes or microelectrode pairs. As a monopole, the microelectrodes 18 can be separated by a distance S1 ranging between about 1 mm and 3 mm, with reference to Fig. 12A As bipolar, adjacent pairs of microelectrodes 18 may be separated by a distance S2 ranging between 1 mm and 6 mm, referring to Fig. 12B .

[0128] In some embodiments, reference Fig. 12B , the six microelectrodes are arranged into three bipolar pairs, the spacing S1 between the proximal edges of the bipolar pairs is 2.0 mm, and the spacing S2 between the proximal edges of adjacent bipolar pairs is 6.0 mm, which three bipolar pairs can generally be referred to as a "2-6-2" configuration. Another configuration called a "2-5-2-5-2" configuration has three bipolar pairs, wherein the spacing S1 between the proximal edges of the bipolar pairs is 2.0 mm, and the spacing S2 between the proximal edges of adjacent bipolar pairs is 5.0 mm.

[0129] In some embodiments, reference Fig. 12A , six microelectrodes are arranged as a monopole, wherein the spacing S1 between the proximal edges of adjacent monopoles is 2.0 mm, which can be referred to as a "2-2-2-2-2" configuration. In some embodiments, the spacing S1 is about 3.0 mm, and is therefore referred to as a "3-3-3-3-3" configuration.

[0130] In some embodiments, the proximal-most microelectrode 18P of each ridge is carried at a different location on the ridge than the proximal-most microelectrode 18P of an adjacent ridge. Fig.13As shown, although the spacing between the microelectrodes on any one ridge may be uniform throughout the distal electrode assembly, the microelectrodes along any one ridge are staggered (or offset) relative to the microelectrodes along adjacent ridges. For example, for ridges 17A, 17C, 17E, and 17G, the distance D1 between the proximal-most microelectrode 18P and the end of the rod 42 is greater than the distance D2 between the proximal-most electrode 18P and the end of the rod 42 for ridges 17B, 17D, 17G, and 17G. This staggered configuration minimizes the risk of microelectrodes on adjacent ridges touching and shorting, particularly when the operator is sweeping the distal electrode assembly against tissue. In addition, this staggered configuration provides a larger effective contact surface for the distal electrode assembly 15 because the effective concentric electrode array is doubled (see Fig.13 ). refer to Fig.13 , Fig.26 and Fig. 27 , the staggering can take on different configurations depending on factors including the distance or spacing between adjacent electrodes on any one ridge. In some embodiments, each ridge can take on a unique staggered configuration ( Fig. 27 In some embodiments, one or more ridges may exhibit the same staggered configuration, as long as the ridges are not adjacent to each other and are separated by at least one or more ridges having a different staggered configuration (see, e.g. Fig.26 In this regard, the spacing between adjacent electrodes along any one ridge may be non-uniform, as long as the spacing between adjacent electrodes along adjacent ridges is different and the electrodes of adjacent ridges are located at different concentricities. The staggered configuration also includes a configuration in which the concentric traces of the electrodes of any one ridge around the longitudinal axis of the assembly 15 are different from the concentric traces of the electrodes of any adjacent ridge.

[0131] The construction of the interface between the distal electrode assembly and the distal portion of the deflection segment 14 and the components of the assembly are described in U.S. Patent Nos. 7,089,045, 7,155,270, 7,228,164, and 7,302,285, the entire disclosures of which are incorporated herein by reference. Fig.14A As shown, the rod 42 of the integral support member 40 receives the narrowed distal end 30D of the multi-lumen tube 30 of the deflection segment 14. A non-conductive sleeve 68 circumferentially surrounds the rod 42, the non-conductive sleeve being coextensive with the rod between the proximal and distal ends of the rod. The distal end 68D of the sleeve 68 extends over the proximal end 28P of the non-conductive spine tube 28 to help secure the tube 28 to the spine 17.

[0132] Proximal to the distal end 30D is a housing insert 60 that is also received and positioned in the lumen 43 of the rod 42 of the integral support member 40. The length of the housing insert 60 in the longitudinal direction is shorter than the length of the rod 42 so that the housing insert does not protrude beyond the distal end of the rod 42. The housing insert 60 is constructed to have one or more lumens. One lumen 71 can have a non-circular cross-section, for example, roughly similar to the cross-section of a "C" or an elongated kidney bean, and the other lumen 72 can have a circular cross-section, such as Fig. 14B As shown, the lumens can be nested within each other to maximize the size of the lumens and increase space efficiency within the housing insert 60. Components passing through more lumens 71 are not constrained to any one position or orientation and therefore have greater freedom of movement and less risk of breakage, especially when sections of the catheter are twisted and components are twisted.

[0133] In some embodiments, the electromagnetic position sensor 26 (at the distal end of the cable 24) is received in the lumen 72. Other components including, for example, the irrigation tube 27 and the leads 22 for the microelectrodes 18 on the distal electrode assembly 15 (as well as the leads 25 for any ring electrodes 67, 69 and 70 proximal to the spine 17) pass through the lumen 71. In this regard, the housing insert 60 provides multiple functions, including aligning and positioning the various components within the rod 42 of the integral support member 40; providing spacing for and separation between these various components, and acting as a mechanical lock that strengthens the joint between the distal end of the deflection segment 14 and the distal electrode assembly 15. In the latter case, during assembly and use of the catheter, the joint may be subjected to a variety of forces that may twist or pull the joint. For example, the torsional force may clamp the irrigation tube 27 to prevent flow, or cause the leads 22 and 25 to break. To this end, the engagement portion is advantageously assembled with the housing insert 60 in a configuration to form a mechanical lock, as explained below.

[0134] The housing insert 60 can be selectively constructed to have an outer diameter that is a predetermined amount less than the inner circumference of the lumen 43 of the rod 42. This creates a perceptible void in the lumen 43 that is filled with a suitable adhesive 61, such as polyurethane, to securely attach the housing insert 60 to the interior of the lumen 43 and to the distal end of the multi-lumen tube 30 so as to minimize (if not prevent) relative movement between the insert 60 and the rod 42. The housing insert 60 protects the components it surrounds, including the electromagnetic position sensor 26 (and its attachment to the cable 24), the irrigation tube 27, and the leads 22 and 25, and provides a larger and more rigid structure to which the rod 42 is attached. To this end, the housing insert 60 can even have a non-circular / polygonal outer cross-section and / or a textured surface to improve the attachment between the housing insert 60 and the adhesive 61.

[0135] To facilitate application of adhesive into the void, the rod 42 is formed with an opening 65 in its sidewall at a location that allows visual and mechanical access to the shell insert 60 after it has been inserted into the lumen 43 of the rod 42. During assembly of the joint, visual inspection of the lumen 43 and the components therein is provided through the opening 65. Although any adhesive applied to the outer surface of the shell insert 60 prior to insertion into the lumen 43 may be ejected from the rod 42 during insertion, additional adhesive may be advantageously applied through the opening 65 into the lumen 43 to fill the void and thereby securely attach the shell insert 60 to the distal portion of the rod 42 and the multi-lumen tube 30. The combination of the shell insert 60 and its spatial accommodation lumen 71 provides a more integrated and less vulnerable joint between the distal electrode assembly 15 and the deflection segment 14.

[0136] In some embodiments, the catheter 10 includes an irrigation tube 27 having a distal end 27D that is generally coextensive with the distal end of the stem 42 of the integral support member 40. Thus, an irrigation fluid (e.g., saline) is delivered to the distal electrode assembly 15 from a remote fluid source that is delivered via the Luer interface 100 ( Figure 1 ) through the irrigation tube 27 extending through the control handle 16, the central lumen 19 of the catheter body 12 ( Figure 2 ) and the lumen 31E of the tube 30 of the deflection segment 14 ( Figure 3 ) provides irrigation fluid, in which case the irrigation fluid exits the distal end of the irrigation tube 27 at the distal end of the rod 42 of the integral support member 40, as shown in FIG. Fig.15A and Fig.25 A suitable adhesive (such as polyurethane) is placed around the distal end of the irrigation tube 27 to block and seal the lumen 43. In some embodiments, the catheter is not irrigated, and the distal end of the stem 42 of the integral support member 40 is integrally sealed with an adhesive or sealant 90 (such as polyurethane), as shown. Fig.14A shown.

[0137] Fig.16 An embodiment is shown in which the non-conductive spine tube 28 includes a reinforced tensile member 53. As will be appreciated by one of ordinary skill in the art, the microelectrodes 18 are mounted on the spine cover or tube 28 with an elongated tubular mandrel (not shown) positioned within the lumen of the spine cover 28 to support the microelectrodes 18 as they are rotationally swaged onto the spine cover 28. The microelectrodes 18 can have a circular cross-section, including a circular or elliptical configuration. In order to prevent or at least minimize undesirable deformation of the microelectrodes 18 and spine cover 28 during swaging, including elongation in the longitudinal direction, the spine cover 28 on which the microelectrodes are carried and swaged includes a reinforced tensile member 53, such as Fig.16 As shown. A tensile member 53 (e.g., a wire or fiber (used interchangeably herein)) is embedded (e.g., during extrusion of the tensile member) in the sidewall 54 of the tube. The tensile member 53 can be embedded in the non-conductive cover extrusion in a uniaxial or woven pattern, extending in the longitudinal direction or at least having a portion extending in the longitudinal direction. Thus, the tensile member is used to resist undesirable elongation in the longitudinal direction of the particularly soft and flexible spine cover 28 and microelectrode 18. Examples of suitable tensile members include VECTRAN, DACRON, KEVLAR or other materials with low elongation properties. A plurality of reinforced tensile members is not a critical factor. In some embodiments, "plurality" can be in a range between two and six arranged in a radially equivalued configuration. In the illustrated embodiment, the spine cover 28 includes four tensile members at 0 degrees, 90 degrees, 180 degrees, and 270 degrees around the sidewall 54.

[0138] In some embodiments, the distal end of tensile member 53 is anchored in bulbous cover 45 that encapsulates the enlarged distal portion of ridge 17 and / or ring 99D (eg, Fig.16 ) can be compressed or clamped on the spine cover 28 and the spine 17. In some embodiments, the proximal end of the tensile member 53 is coextensive with the proximal end of the spine cover 28 and can also be anchored by the ring 99P (see Fig.14A and Fig.15A ).

[0139] In some embodiments, tensile member 53 has a much greater length. Fig.17 , Fig.18 , Fig.19 and Fig. 20 , the tensile member 53 extends through the opening 44 formed in the rod 42 of the integral support member 40 and into the lumen 43 of the rod 42. The tensile member 53 then extends through the lumen 71 of the housing insert 60, the lumen 31F of the tube 30 of the deflection segment 14, and the central lumen 19 of the catheter body 12, and extends into the control handle 16. The proximal end of the tensile member 53 is configured to be manipulated by the operator to deflect the ridges 17 of the distal electrode assembly 15 so that they can be used individually as "fingers". In this regard, the tensile members can be formed in the sidewall of the tube 28 in a manner that allows longitudinal movement relative to the tube 28, so that any one or more of the tensile members can be pulled proximally to bend or deflect the corresponding ridges toward the side along which those tensile members extend. Thus, the operator is able to manipulate one or more ridges for individual deflection as needed or desired, including when the distal electrode assembly is in contact with an uneven tissue surface, in which case one or more ridges need to be adjusted to better make tissue contact.

[0140] refer to Fig.21 , Fig. 22 , Fig.23 and Fig.24 , showing the catheter 10 of the present invention being used in all four chambers of the heart (i.e., left and right atria, left and right ventricles), wherein the spines of the distal electrode assembly 15 easily adapt and conform to various contours and surfaces of cardiac tissue anatomy (including, for example, inside the pulmonary veins, and on the posterior wall of the right atrium, the anterior, inferior and / or lateral walls of the left and right ventricles, and the apex). Regardless of the anatomical structure of the surface, the pre-shaped configuration of the spines advantageously promotes contact between the microelectrodes carried on the spines and the tissue.

[0141] In some embodiments, the catheter 10 has a plurality of ring electrodes proximal to the distal electrode assembly 15. In addition to the ring electrodes 67, Figure 1 As shown, the catheter also carries another ring electrode 69 more proximal than the ring electrode 67, and another ring electrode 70 more proximal than the ring electrode 69. Leads 25 are provided for these ring electrodes. In some embodiments, the ring electrode 69 is located near the distal end 30D of the multi-lumen tube 30 of the deflection section 14, and the ring electrode 70 is separated from the ring electrode 69 by a distance S in the range between about 1 mm and 3 mm. The corresponding leads 25 are connected to the ring electrode 67 via openings 75 formed in the rod 42 of the integral support member 40 and in the sleeve 68. The corresponding leads 25 for the ring electrodes 69 and 70 are connected to passage openings (not shown) formed in these side walls of the tube 30 of the deflection segment 14.

[0142] Each portion of the puller wires 23A and 23B extending through the catheter body 12 is circumferentially surrounded by corresponding compression coils 101A and 101B, as understood in the art. Each portion of the puller wires 23A and 23B extending through the multi-lumen tube 30 of the deflection section is circumferentially surrounded by a sheath that protects the puller wires so that the puller wires do not cut into the tube when deflected. As understood in the art, the distal ends of the puller wires can be anchored in the sidewall of the tube 30 at or near the distal end of the tube 30. As understood in the art, the proximal ends of the puller wires are anchored in the control handle 16 for actuation by the operator of the catheter.

[0143] The foregoing description has been presented with reference to the presently preferred embodiments of the invention. Those skilled in the art to which the invention pertains will appreciate that changes and modifications may be made to the structures described without intentionally departing from the principles, spirit and scope of the invention. Any feature or structure disclosed in one embodiment may be incorporated as needed or appropriate to replace or supplement other features of any other embodiment. As will be appreciated by those of ordinary skill in the art, the drawings are not necessarily drawn to scale. Therefore, the above-described specific embodiments should not be interpreted as being suitable only for the precise structures described and shown in the drawings, but rather should be interpreted as being consistent with and supporting the following claims, which have a full and fair scope of the invention.

Claims

1. An electrophysiological catheter, comprising: Slender body; A distal electrode assembly, the distal electrode assembly comprising: a proximal rod defining a circumference about the longitudinal axis; and a plurality of ridges emanating from the proximal stem and diverging at a distal end thereof, the plurality of ridges alternating between first ridges and second ridges around the circumference of the proximal stem; a plurality of non-conductive ridge covers, each ridge cover surrounding a respective ridge; and A plurality of microelectrodes having a staggered configuration between the first ridge and the second ridge, wherein the most proximal microelectrode on each first ridge is positioned at a greater distance from the proximal rod and the most proximal electrode on each second ridge is positioned at a lesser distance from the proximal rod.

2. The catheter of claim 1, wherein the distal electrode assembly comprises at least four first ridges and four second ridges, and each ridge carries six microelectrodes.

3. The catheter of claim 1, wherein the microelectrodes on the first ridge have a first separation distance from each other, and the microelectrodes on the second ridge have a second separation distance, wherein the first separation distance is approximately the same as the second separation distance.

4. The catheter of claim 1, wherein the microelectrodes on the first ridge have a first separation distance from each other, and the microelectrodes on the second ridge have a second separation distance, wherein the first separation distance is different from the second separation distance.

5. The catheter of claim 1, wherein the microelectrode is configured as a monopolar.

6. The catheter of claim 1, wherein the microelectrode is configured as a bipolar.

7. An electrophysiological catheter, comprising: Slender body; A distal electrode assembly, the distal electrode assembly comprising a support body, the support body having: proximal rod; A plurality of ridges span outwardly from the proximal shaft, each ridge carrying a plurality of microelectrodes, each electrode defining a concentricity, wherein the concentricity of the microelectrodes on one ridge is different than the concentricity of the microelectrodes on an adjacent ridge.

8. An electrophysiological catheter as claimed in claim 7, wherein the plurality of microelectrodes carried on each spine are identical.

9. An electrophysiological catheter as claimed in claim 7, wherein the plurality of microelectrodes carried on adjacent ridges are different.

10. The EP catheter of claim 7, wherein the plurality of ridges is eight.

11. The electrophysiology catheter of claim 7, wherein the plurality of microelectrodes on each ridge is six.

12. The EP catheter of claim 7, wherein the plurality of ridges ranges between six and eight.

13. The EP catheter of claim 7, wherein the plurality of microelectrodes ranges between six and eight.

14. The catheter of claim 7, wherein the microelectrodes on each ridge are separated by a distance ranging between 1 mm and 3 mm as measured between leading edges of the microelectrodes.

15. The catheter of claim 14, wherein the distance is 2 mm.

16. A catheter according to claim 7, wherein the microelectrodes on each ridge are arranged as bipolar pairs, wherein the leading edges of the microelectrodes within a pair are separated by a first distance in the range between 1 mm and 3 mm, and wherein the leading edges of the leading microelectrodes between multiple pairs are separated by a second distance in the range between 1 mm and 6 mm.

17. The catheter of claim 16, wherein the first distance is 2 mm and the second distance is 6 mm.

18. The catheter of claim 7, wherein the plurality of microelectrodes is equal to 64.

19. The catheter of claim 7, wherein the plurality of microelectrodes is equal to 72.

20. The catheter of claim 7, further comprising: a first annular electrode carried on the proximal rod of the distal electrode assembly; and A second annular electrode and a third annular electrode are carried on a distal portion of the elongated body.

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