LESION PREDICTING FLEX TIP

The instant disclosure relates generally to a wire electrode (309) disposed on a medical device (301). A catheter assembly can comprise a catheter body (321), a tip electrode (303), and a wire electrode (309). The tip electrode (303) can be coupled to a distal end of the catheter body (321).

BACKGROUND

The instant disclosure relates generally to a tip electrode for delivering and receiving energy and delivering irrigant to the tip electrode and catheter tip assemblies incorporating such a tip electrode.

b. Background Art

Electrophysiology catheters are used in a variety of diagnostic, therapeutic, and/or mapping and ablative procedures to diagnose and/or correct conditions such as atrial arrhythmias, including for example, ectopic atrial tachycardia, atrial fibrillation, and atrial flutter. Arrhythmias can create a variety of conditions including irregular heart rates, loss of synchronous atrioventricular contractions and stasis of blood flow in a chamber of a heart which can lead to a variety of symptomatic and asymptomatic ailments and even death.

Typically, a catheter is deployed and manipulated through a patient's vasculature to the intended site, for example, a site within a patient's heart or a chamber or vein thereof. The catheter carries one or more electrodes that can be used for cardiac mapping or diagnosis, ablation and/or other therapy delivery modes, or both, for example. Once at the intended site, treatment can include, for example, radio frequency (RF) ablation, cryoablation, laser ablation, chemical ablation, high-intensity focused ultrasound-based ablation, microwave ablation, and/or other ablation treatments. The catheter imparts ablative energy to cardiac tissue to create one or more lesions in the cardiac tissue and oftentimes a contiguous or linear and transmural lesion. This lesion disrupts undesirable cardiac activation pathways and thereby limits, corrals, or prevents errant conduction signals that can form the basis for arrhythmias.

To position a catheter within the body at a desired site, some type of navigation must be used, such as using mechanical steering features incorporated into the catheter (or an introducer sheath). In some examples, medical personnel may manually manipulate and/or operate the catheter using the mechanical steering features.

In order to facilitate the advancement of catheters through a patient's vasculature, the simultaneous application of torque at the proximal end of the catheter and the ability to selectively deflect the distal tip of the catheter in a desired direction can permit medical personnel to adjust the direction of advancement of the distal end of the catheter and to position the distal portion of the catheter during an electrophysiological procedure. The proximal end of the catheter can be manipulated to guide the catheter through a patient's vasculature. The distal tip can be deflected by a pull wire attached at the distal end of the catheter that extends to a control handle that controls the application of tension on the pull wire.

A medical procedure in which an electrophysiology catheter is used includes a first diagnostic catheter deployed through a patient's vasculature to a patient's heart or a chamber or vein thereof. An electrophysiology catheter that carries one or more electrodes can be used for cardiac mapping or diagnosis, ablation and/or other therapy delivery modes, or both. Once at the intended site, treatment can include radio frequency (RF) ablation, cryoablation, laser ablation, chemical ablation, high-intensity focused ultrasound-based ablation, microwave ablation, etc. An electrophysiology catheter imparts ablative energy to cardiac tissue to create one or more lesions in the cardiac tissue and oftentimes a contiguous or linear and transmural lesion. This lesion disrupts undesirable cardiac activation pathways and thereby limits, corrals, or prevents stray errant conduction signals that can form the basis for arrhythmias.

Because RF ablation can generate significant heat, which if not controlled can result in excessive tissue damages, such as steam pop, tissue charring, and the like, it can be desirable to monitor the temperature of ablation electrode assemblies. It can also be desirable to include a mechanism to irrigate the ablation electrode assemblies and/or targeted areas in a patient's body with biocompatible fluids, such as saline solution. The use of irrigated ablation electrode assemblies can also prevent the formation of soft thrombus and/or blood coagulation, as well as enable deeper and/or greater volume lesions as compared to conventional, non-irrigated catheters at identical power settings.

The foregoing discussion is intended only to illustrate the present field and should not be taken as a disavowal of claim scope.

BRIEF SUMMARY

In one embodiment, a catheter tip electrode can comprise a flexible electrode structure configured to flex upon application of an external force, a distal end portion adjacent the flexible electrode structure and defining a distal end, and a wire electrode.

In another embodiment, a catheter assembly can comprise a catheter body, a tip electrode, and a wire electrode. The tip electrode can be coupled to a distal end of the catheter body.

In yet another embodiment, a catheter tip electrode can comprise a flexible electrode structure configured to flex upon application of an external force, a distal end portion adjacent the flexible electrode structure and defining a distal end, a first wire electrode, and a second wire electrode.

DETAILED DESCRIPTION OF THE DISCLOSURE

It will be appreciated that the terms “proximal” and “distal” may be used throughout the specification with reference to a clinician manipulating one end of an instrument used to treat a patient. The term “proximal” refers to the portion of the instrument closest to the clinician and the term “distal” refers to the portion located furthest from the clinician. It will be further appreciated that for conciseness and clarity, spatial terms such as “vertical,” “horizontal,” “up,” and “down” may be used herein with respect to the illustrated embodiments. However, medical instruments may be used in many orientations and positions, and these terms are not intended to be limiting and absolute.

FIG. 1generally illustrates a deflectable electrophysiology catheter10that comprises a deflectable catheter shaft section12in accordance with an embodiment. Deflectable catheter shaft section12comprises an elongated body having a distal end14and a proximal end16. In its most general form, catheter10further comprises a tip assembly18located at the distal end14of the deflectable catheter shaft section12, a proximal catheter shaft section20located at the proximal end16of the deflectable catheter shaft section12, and a handle assembly22. Catheter10may be used in any number of diagnostic and therapeutic applications, such as the recording of electrograms in the heart, the performance of a cardiac ablation procedure, and other similar applications/procedures. Accordingly, one of ordinary skill in the art will recognize and appreciate that the inventive deflectable catheter shaft section and method of manufacturing the same can be used in any number of diagnostic and therapeutic applications.

Still referring toFIG. 1, deflectable catheter shaft section12is disposed between the tip assembly18and the proximal catheter shaft section20. The length and diameter of the deflectable catheter shaft section12can vary according to the application. Generally, the length of the deflectable catheter shaft section12can range from about 2 inches (50.8 mm) to about 6 inches (152.4 mm) and the diameter of the deflectable catheter shaft section12can range from about 5 French to about 12 French. The diameter of the deflectable catheter shaft section12can be about 7 French in accordance with some embodiments. Although these particular dimensions are mentioned in particular, the dimensions of the deflectable catheter shaft section12can vary in accordance with various applications of the deflectable catheter shaft section12. The deflectable catheter shaft section12can be configured for deflection independent of the proximal catheter shaft section20.

Tip assembly18comprises a tip electrode56having a distal end50and a proximal end52. Tip electrode56may be configured for various functions and may include, without limitation, an active outer surface that is configured for exposure to blood and/or tissue. The tip electrode56may be affixed to distal end14of the deflectable catheter shaft section12in a number of ways. For instance, the tip electrode56may be bonded to an inner radial surface of the deflectable catheter shaft section12using an epoxy material. As used herein, the term “radial surface” means a surface at a radial distance from a central axis or a surface developing uniformly around a central axis (for example, but without limitation, an arcuate surface, an annular surface, or a cylindrical surface). The tip electrode56of the tip assembly18may have a recess (not shown) formed therein that is sufficiently sized and configured to receive a wire (not shown) that is connected to the tip electrode56. One end of the wire is connected to the tip electrode56and the other end is connected to, for example, monitoring or recording or ablation devices, such as a radiofrequency (RF) generator. The wire is typically a pre-coated wire that is insulated from other components in the tip assembly18. The tip electrode56of the tip assembly18may further include a recess (not shown) formed therein that is configured to receive a thermocouple (not shown). The thermocouple may be configured to measure the temperature of the tip electrode56, targeted tissue, and/or the interface therebetween and provide feedback to the monitoring or recording or ablation devices described hereinabove. The tip electrode56may further include a fluid lumen configured as a passageway for irrigation fluid.

Proximal catheter shaft section20can also include one or more lumens (not shown). Generally, proximal catheter shaft section20can include a single lumen. Proximal catheter shaft section20can also be constructed of a series of polymer layer(s) and braid structure(s). In particular, one or more wires wound to form a cylindrical braid structure can substantially surround the one or more lumens of proximal catheter shaft section20. In addition, a polymeric material, such as polyurethane, nylon, or various types of plastic materials such as polyether block amides offered under the trademark PEBAX®, or any other suitable material, can also substantially surround the one or more lumens of proximal catheter shaft section20. Regardless of the material used, the material must have capability to be displaced or to shrink when subjected to a process, such as for example, a heating process that is performed. The mechanical properties of the proximal catheter shaft section20can also be varied by varying the properties of the cylindrical braid structure(s) and the polymeric material (e.g., dimension of the cylindrical braid structure and/or durometers of the polymers). Additionally, the mechanical properties of the proximal catheter shaft section20can be varied along the length of the proximal catheter shaft section20in accordance with some embodiments of the disclosure or can be substantially constant along the entire length of the proximal catheter shaft section20in accordance with other embodiments of the disclosure.

The handle assembly22is coupled to the proximal catheter shaft section20at its proximal end (disposed within handle assembly22and not shown). The handle assembly22is operative to, among other things, effect movement (i.e., deflection) of the deflectable catheter shaft section12. The handle assembly22includes a distal end94and a proximal end96.

The catheter10may include any number of other elements such as, for example and without limitation, thermocouples, thermistor temperature sensors, etc. for monitoring the temperature of targeted tissue and controlling the temperature.

FIG. 2generally illustrates another embodiment of a deflectable electrophysiological catheter210. The embodiment of the catheter depicted inFIG. 2comprises a handle assembly where a push/pull action is performed to deflect the deflectable catheter shaft section212. The deflectable catheter shaft section212comprises an elongated body having a distal end214and a proximal end216. The deflectable electrophysiological catheter210further comprises a tip assembly218located at the distal end of the deflectable catheter shaft section214, a proximal catheter shaft section220, and a handle assembly222.

Deflectable catheter shaft section212is disposed between the tip assembly218and the proximal catheter shaft section220. The length and diameter of the deflectable catheter shaft section212can vary according to the application. Generally, the length of the deflectable catheter shaft section212can range from about 2 inches (50.8 mm) to about 6 inches (152.4 mm) and the diameter of the deflectable catheter shaft section212can range from about 5 French to about 12 French. The diameter of the deflectable catheter shaft section212can be about 7 French in accordance with some embodiments. Although these particular dimensions are mentioned in particular, the dimensions of the deflectable catheter shaft section212can vary in accordance with various applications of the deflectable catheter shaft section212. The deflectable catheter shaft section212can be configured for deflection independent of the proximal catheter shaft section220.

Tip assembly218comprises a tip electrode256having a distal end250and a proximal end252. Tip electrode256may be configured for various functions and may include, without limitation, an active outer surface that is configured for exposure to blood and/or tissue. The tip electrode256may be affixed to distal end214of the deflectable catheter shaft section212in a number of ways. For instance, the tip electrode256may be bonded to an inner radial surface of the deflectable catheter shaft section212using an epoxy material. As used herein, the term “radial surface” means a surface at a radial distance from a central axis or a surface developing uniformly around a central axis (for example, but without limitation, an arcuate surface, an annular surface, or a cylindrical surface). The tip electrode256of the tip assembly218may have a recess (not shown) formed therein that is sufficiently sized and configured to receive a wire (not shown) that is connected to the tip electrode256. One end of the wire is connected to the tip electrode256and the other end is connected to, for example, monitoring or recording or ablation devices, such as a radiofrequency (RF) generator. The wire is typically a pre-coated wire that is insulated from other components in the tip assembly218. The tip electrode56of the tip assembly218may further include a recess (not shown) formed therein that is configured to receive a thermocouple (not shown). The thermocouple may be configured to measure the temperature of the tip electrode256, targeted tissue, and/or the interface therebetween and provide feedback to the monitoring or recording or ablation devices described hereinabove. The tip electrode56may further include a fluid lumen configured as a passageway for irrigation fluid.

FIGS. 3 and 4depict a deflectable catheter shaft section12′ similar to the deflectable catheter shaft section12shown to good advantage in, for example,FIGS. 1, and 2. As shown inFIGS. 3 and 4, the catheter shaft may include the deflectable catheter shaft section12′, an intermediate catheter shaft section164, and a proximal catheter shaft section (not shown inFIGS. 3 and 4, but the proximal catheter shaft section, if present, would abut the right longitudinal end, as oriented inFIGS. 3 and 4, of the intermediate catheter shaft section164). In this embodiment, two shaft couplers are used, including a proximal shaft coupler60pfor coupling the proximal catheter shaft section to the intermediate catheter shaft section164, and a distal shaft coupler60D for coupling the intermediate catheter shaft section164to the deflectable catheter shaft section12′.

In at least one embodiment, the proximal catheter shaft section may comprise a portion of the handle assembly, e.g., the proximal catheter shaft section may comprise a pocket (not shown) sized and configured to receive a proximal shaft coupler60pand formed in the distal end94of handle assembly22seen inFIG. 1. In an alternative embodiment, it is possible, depending upon which handle assembly22is selected, that the handle assembly may connect to the proximal end168of the intermediate catheter section164, or to the proximal end166of the proximal shaft coupler60p. In these latter configurations, the intermediate catheter shaft section164would be analogous to the proximal catheter section shown in, for example,FIG. 1.

Referring more particularly toFIG. 4, additional details will be described.FIG. 4is a cross-sectional view taken along line4-4ofFIG. 3. Starting from the right side ofFIG. 4and moving leftward, a proximal end166of the proximal shaft coupler60pmay be seen extending proximally beyond the proximal end168of the intermediate catheter shaft section. It is also possible to see that the intermediate catheter shaft section164may include a first shaft material170(e.g., PEBAX) and a second shaft material172(e.g., PEBAX or braided mesh). A first pull wire40may be seen extending along the upper portion of the proximal shaft coupler60p, and a second pull42wire may be seen extending adjacent a lower portion of the proximal shaft coupler60p. The portion of these pull wires40,42extending from the proximal end166of the proximal shaft coupler60pback to the handle assembly22(see, for example,FIG. 1) may have compression coils surrounding them. Additionally, there may be compression coils (not shown) extending between a distal end174of the proximal shaft coupler60pand a proximal end176of the distal shaft coupler60D. These compression coils would be under compression (e.g., they may be compressed 0.070 in.) to help mitigate against undesirable deformation of the intermediate catheter shaft section164extending between the proximal and distal shaft couplers. In the embodiment shown, the compression coils do not extend through the proximal shaft coupler, but they could in an alternative embodiment.

Moving further leftward inFIG. 4, the distal shaft coupler60D, which is depicted as joining the intermediate catheter shaft section164(which, as discussed above, may extend to the handle assembly22) to the deflectable catheter shaft section12′ that extends from the distal shaft coupler to the tip assembly18′. As shown inFIG. 4, when the first pull wire40exits the distal end178of the distal shaft coupler60D, it enters a liner182(e.g., a thin-walled PTFE tube). The second pull wire42, upon exiting the distal end178of the distal shaft coupler60D, extends through a bendable stiffening member (e.g., a ‘coil pack’ or a ‘spring pack’ or an ‘uncompacted spring pack’ or a ‘deflection facilitator’)184, the proximal end of which is visible inFIG. 4.

Distal to the pull ring48′ in the configuration depicted inFIGS. 3 and 4are a plurality of ring electrodes54followed distally by a tip assembly18′, including, for example, a flexible tip electrode from a Therapy™ Cool Flex™ ablation catheter manufactured by St. Jude Medical, Inc. of St. Paul, Minn. Additional details regarding a flexible electrode tip may be found in, for example, U.S. Pat. No. 8,187,267 B2 and United States patent application publication no. US 2010/0152731 A1, each of which is hereby incorporated by reference as though fully set forth herein. The tip assembly18′, as depicted inFIG. 4, also includes a barbed connector185that locks into a complementary pocket187, thereby facilitating delivery of irrigant to a ported fluid distribution tube189.FIG. 5is an end view of the tip assembly18′ (looking in the direction of the arrows on line5-5ofFIG. 4) and illustrates a plurality of irrigation ports190through the distal surface of the tip.

In various embodiments, a catheter may comprise a flexible tip assembly, which may be positioned and/or constructed similar to tip assemblies18and/or18′ described above. However, impedance values, measured with a flex tip can vary drastically and can be measured through the tip and a reference electrode located on a patient's skin. The distance between these two points and variation induced by cardiac motion and respiration can induce error into the measured values. These issues can induce errors into lesion prediction algorithms. Further, bi-pole tissue measurement between a tip electrode and a ring electrode or other adjacent electrode pairs can produce error or can lack fidelity due to relatively large gaps between the surfaces of the electrodes and the requirement of maintaining electrode tissue contact during data acquisition. As a result, ensuring that both electrodes are in contact with tissue might prove difficult and/or be inconsistent. One solution to this problem is to add a fine or small gauge electrode to the surface of an electrode or adjacent to an electrode. By adding an electrode of this type, the distance between the electrodes can be limited to the insulation thickness or distance and this can eliminate variations with measuring between the patient reference patch. Further, by decreasing the distance between the electrodes, determinations regarding lesion formation could be more quickly obtained than when using larger electrodes or those with farther space between. Further discussion of a flexible tip electrode can be found in U.S. application Ser. No. 14/969,272, filed 15 Dec. 2015, titled FLEXIBLE ELECTRODE TIP WITH HALO IRRIGATION which is hereby incorporated by reference in its entirety as though fully set forth herein.

FIG. 6illustrates a side view of a catheter301. The catheter301comprises a catheter shaft305and a tip electrode303. The catheter shaft305can comprise a catheter body321. The catheter body321can comprise a catheter body distal end317and can be disposed proximal of the tip electrode303. The catheter body distal end317can be coupled to the tip electrode303. The catheter body321can be constructed of a series of polymer layer(s) and braid structure(s). In particular, one or more wires wound to form a cylindrical braid structure can substantially surround the one or more lumens of proximal catheter shaft section20. In addition, the catheter body321can comprise a polymeric material, such as polyurethane, nylon, or various types of plastic materials such as polyether block amides offered under the trademark PEBAX®, or any other suitable material. The tip electrode303can comprise an electrode wall319, at least one slot315, an electrode cap311, and a wire electrode309. The wire electrode309can comprise a wire307and an insulation313. The insulation313can electrically isolate the wire307from rest of the tip electrode303. In one embodiment, the insulation can comprise a polyimide. In other embodiments, the insulation can comprise other materials with insulative properties. In some embodiments, the material will be electrically and/or thermally insulative and biocompatible. The insulative material can comprise a layer that is less than half a thousandth of an inch in thickness. In other embodiments, the layer of insulative material can be greater than or lesser than this thickness depending on the applications that the wire electrode is designed to be used. Generally, higher voltage applications of the wire electrode require greater thicknesses of insulation. In one embodiment, the insulative material layer can comprise a thickness of one ten thousandth of an inch. In other embodiments, the layer of insulative material can comprise a thickness of two thousandths of an inch. In yet other embodiments, the thickness of the insulative material or other material can comprise ranges between these or above or below depending on the properties of the insulative material and the desired applications and procedures that will use the wire electrode.

In the illustrated embodiment, the wire electrode309can be disposed between the electrode wall319and the electrode cap311. In other embodiments, as seen throughout the application, the wire electrode can be disposed proximal the at least one slot or in other portions of the electrodes as would be understood by one of ordinary skill in the art. The wire electrode309can be disposed within a tip electrode trough or tip electrode depression as described below. While the wire electrode is depicted on a flexible tip electrode, the wire electrode can be disposed on a non-flexible tip electrode, on ring electrodes, on a body of a catheter, and any other location that would be known to one of ordinary skill in the art. Further, more than one wire electrode can be present on a tip electrode, ring electrode, and/or catheter body. In some embodiments, each of the tip electrode, ring electrodes, and catheter body can comprise a plurality of wire electrodes. In other embodiments, a plurality of wire electrodes can be disposed on any one or multiple of the tip electrode, ring electrode, and catheter body. The wire electrode can comprise a bio-compatible wire. In one embodiment, the wire of the wire electrode can comprise one or more of a platinum alloy, a platinum-iridium alloy, a nickel alloy, and gold. In one embodiment, the wire of the wire electrode can comprise the same material as the surrounding tip electrode, ring electrode, or other nearby or surrounding electrode. However, in other embodiments, the wire of the wire electrode does not have to comprise the same material as the electrode tip, ring electrode, or other material present on or within the catheter.

The wire electrode can be used to predict lesion formation. The wire electrode can be used or configured to determine or sense an impedance of tissue that is contacting the wire electrode. Changes in the impedance can be used to determine contact with a tissue. Further, spectral scans can be performed to determine tissue depth.

FIG. 7illustrates an isometric side view of a tip assembly351. The tip assembly351comprises an electrode stem355and a tip electrode353. The electrode stem355comprises an anchor point379, a stem lumen373, a stem wire lumen365, and a stem outer wall381. The stem outer wall381can define an outer diameter of the electrode stem355. Further, the stem outer wall381can be configured to be placed within a distal end of a catheter body and can be secured and/or coupled to the distal end of the catheter body. The anchor point379can comprise a depression within the stem outer wall381. The anchor point379can be sized and shaped to contain an anchor for the tip assembly351and can extend from a proximal end of the electrode stem355to a more distal portion. In one embodiment, the anchor point can extend from a proximal end of the electrode stem to a distal portion of the electrode stem. In another embodiment, the anchor point can extend from a proximal end of the electrode stem to a middle portion of the electrode stem. In another embodiment, the anchor point can comprise a first anchor point and electrode stem can comprise a second anchor point. The stem lumen373can comprise a lumen wall375. The lumen wall375can define the stem lumen373. In the illustrated embodiment, the lumen wall375can define a stem major lumen371and a stem minor lumen377within the stem lumen373. The stem lumen373can extend from a proximal end of the electrode stem355to a distal end of the stem lumen373. In the illustrated embodiment, the stem lumen can comprise a figure-eight shape. In the illustrated embodiment, the stem major lumen371and the stem minor lumen377can be coupled or conjoined. Further, in the illustrated embodiment the stem minor lumen377can comprise a smaller diameter than the stem major lumen371. In other embodiments, the stem minor lumen can comprise a diameter that is the same or similar size to the stem major lumen. Further, in other embodiments, the stem minor lumen and stem major lumen can be separate and not conjoined. The stem wire lumen365can comprise a wire lumen wall367. The wire lumen wall367can define the stem wire lumen365. The stem wire lumen365can extend from a proximal end of the electrode stem355to a distal end of the stem lumen373. The tip electrode353can comprise an electrode cap357, a wire electrode387, an electrode wall383, and at least one slot385. The wire electrode387can comprise a wire391, an insulation393, and a wire electrode end389. The insulation393can surround a portion of the wire391as described throughout this application and can be used to electrically insulate the wire from the rest of the tip electrode. The wire electrode end can comprise an end portion of the wire electrode. The wire electrode can pass from an inner portion of the tip electrode and be disposed within a channel or depression within an outer surface of the tip electrode. The wire electrode can be disposed within the channel or depression as it wraps around an outer circumference of the tip electrode. When the distal end or distal portion of the wire electrode meets with the portion of the wire electrode that exits the interior portion of the tip electrode, the distal end or portion of the wire electrode can be laser welded to secure the distal end or portion in place. In another embodiment, the distal end of the wire electrode can be laser welded to a more proximal portion of the wire electrode. In this embodiment, the wire electrode can then be laser welded to the tip electrode. In yet another embodiment, the wire electrode can be laser welded to a ring electrode. In yet another embodiment, a distal portion of the wire electrode can be secured within an inner portion of the tip electrode or catheter body. In other embodiments, other methods can be used to secure the wire electrode and/or the distal end or end portion of the wire electrode to the tip electrode. In one embodiment, a glue or other adhesive can be used to secure the wire electrode to the tip electrode. In yet another embodiment, the wire electrode can be swaged to secure the electrode. In some embodiments, when the wire electrode is initially secured to the tip electrode or catheter body, the insulation of the wire electrode can completely or mostly surround the wire of the wire electrode. In some embodiments, the wire can comprise a circular cross-section. The insulation and wire that protrudes above an outer surface of the tip electrode or catheter body can then be removed so that a flat outer surface is created between an outer surface of the electrode, wire electrode insulation and wire electrode wire. By removing the portion of the wire electrode that protrudes above the height of neighboring surfaces a smooth outer surface can be created while keeping a layer of insulation between the wire electrode and any adjacent surfaces. In one embodiment, the portion of the wire electrode protruding beyond an outer surface of an adjacent electrode can be ground to product the exposed electrode surface. Grinding the electrode to expose the electrode surface can have the advantage of ensuring virgin metal as adhesive or other products can cause issues with signal acquisition if disposed on a surface of the wire electrode. In yet another embodiment, the wire electrode be sized and shaped to fit within the channel and not require additional processing of the height of the electrode to create the wire electrode described herein. In some embodiments, a thermal sensor can be placed adjacent and/or underneath the wire electrode to determine local temperatures.

The wire electrode can be advantageous as it allows for an inexpensive way to add an additional electrode adjacent and/or within other electrodes. Further, the wire electrode can alleviate concerns regarding orientation of the device as in some embodiments the wire electrode surrounds an outer circumference of the tip electrode and/or catheter shaft. Additionally, the wire electrode can allow for a “ring2” to be close to the lesion itself. In one embodiment, as illustrated herein, the wire electrode can be disposed adjacent the tip of the tip electrode. In another embodiment, the wire electrode can be disposed around 0.6 mm from distal end of the tip electrode. Further, the wire electrode can be used to acquire improved data for bipolar measurements from the medical device.

FIG. 8depicts a side view of one embodiment of an electrode cap401. The electrode cap401can comprise a cap outer surface423, a center irrigation port407, at least one outer irrigation port411, a wire electrode lumen415, a proximal end409, and a wire electrode405. The wire electrode405can comprise a wire419, an insulation417, and a wire electrode conductor413. The wire electrode conductor413can be coupled to the wire419. In one embodiment, the wire electrode conductor413can be contiguous with the wire419and they can comprise a single structure. Further, a portion of the wire electrode conductor413can be disposed within the wire electrode lumen415. The insulation417can electrically insulate the wire419from the cap outer surface423and from the proximal end409. In the illustrated embodiment, the wire electrode405is disposed within the electrode cap401. The center irrigation port407and the at least one outer irrigation port411can comprise through-holes to allow for irrigant to pass from the proximal end409of the electrode cap to the distal end of the electrode cap401. Further, the center irrigation port407and the at least one outer irrigation port411can be configured to allow for irrigant to pass from an inner portion of the tip electrode to an area outside and distal of the electrode cap and the tip electrode. The proximal end409of the electrode cap401can be shaped to couple to a distal end of an electrode wall.

FIG. 9illustrates a side view of one embodiment of a partial tip electrode451. The partial tip electrode451can comprise a distal end457, a sidewall469, an inner wall455, at least one slot467, and a wire electrode453. The wire electrode453can comprise a wire461, an insulation459, and a wire electrode conductor463. The wire electrode453can be disposed distal of the sidewall469. In the illustrated embodiment, the wire electrode453can be coupled to the inner wall455. The inner wall455can comprise an opening465. The wire electrode conductor463can pass through the opening465of the inner wall455to couple to the wire electrode453. The insulation459can surround an interior facing portion of the wire461as described throughout the application. In the illustrated embodiment, the sidewall469, the inner wall455, and the wire electrode453can comprise a circular cross-section. Further, in the illustrated embodiment, an outer diameter of the wire electrode453can be the same as an outer diameter of the sidewall469. In other embodiments, the outer diameter of the wire electrode453can be the less than the outer diameter of the sidewall469. In yet other embodiments, the outer diameter of the wire electrode453can be the greater than the outer diameter of the sidewall469.

FIG. 10illustrates a side view of one embodiment of an electrode cap501. The electrode cap501can comprise a cap outer surface503, a channel515, a cap opening511, and a proximal end513. The channel515can be defined by a channel proximal wall509, a channel inner wall507, and a channel distal wall505. The channel515can be sized and shaped to contain a wire electrode as described herein. The cap opening511can allow for a wire electrode conductor to pass from an inner portion of the electrode cap and couple to a wire electrode. In the illustrated embodiment, the channel inner wall507can be coupled to the channel distal wall505and the channel proximal wall509. The channel inner wall507can comprise a flared portion where the channel inner wall507couples to the channel proximal wall509and to the channel distal wall505.

FIG. 11illustrates a partial side view of a distal portion of a tip electrode551The tip electrode551can comprise an electrode cap553, a sidewall563, at least one slot531, and a wire electrode555. The wire electrode555can comprise a wire557and an insulation559. In the illustrated embodiment, the wire electrode555can be disposed around an outer circumference of the sidewall563. The wire electrode555can further be disposed at a distal end of the sidewall563and adjacent to the electrode cap553. The insulation559can cover an interior portion of the wire557. The insulation559can electrically insulate the wire557from the sidewall563and the electrode cap553.

FIG. 12illustrates a partial side view of a tip electrode601. The tip electrode601can be coupled to a catheter body621. The tip electrode601can comprise an electrode cap603, a sidewall619, at least one slot611, a first wire electrode605, and a second wire electrode613. The first wire electrode605can comprise a first wire607and a first insulation609. The second wire electrode613can comprise a second wire615and a second insulation617. In the illustrated embodiment, the first wire electrode605can be disposed around an outer circumference of the sidewall619. The first wire electrode605can further be disposed at a distal end of the sidewall619and adjacent to the electrode cap603. The first insulation609can cover an interior portion of the first wire607. The first insulation609can electrically insulate the first wire607from the sidewall619and the electrode cap603The second wire electrode613can be disposed around an outer circumference of the sidewall619. The second wire electrode613can further be disposed at a proximal end of the sidewall619and adjacent to the catheter body621. The second insulation617can cover an interior portion of the second wire615. The second insulation617can electrically insulate the second wire615from the sidewall619. In one embodiment, the second wire electrode613can be disposed next to the catheter body621. In another embodiment, a proximal portion of the sidewall can be positioned between the second wire electrode and the catheter body. In yet another embodiment, at least a portion of the at least one slot can be positioned proximal of the second wire electrode.

FIG. 13depicts a partial side view of a catheter651. The catheter651can comprise a catheter shaft655and a tip electrode653. The tip electrode653can comprise a sidewall657, at least one slot665, and a first wire electrode661. The first wire electrode661can comprise a first wire663and a first insulation659. The catheter shaft655can comprise a shaft body677, a first ring electrode667, a second ring electrode675, and a second wire electrode669. The second wire electrode669can comprise a second wire673and a second insulation671. In the illustrated embodiment, the first ring electrode667can be disposed adjacent a proximal end of the tip electrode653. A portion of the shaft body677can be disposed between the first ring electrode667and the tip electrode653This portion of the shaft body677can electrically insulate the first ring electrode667from the tip electrode653. In the illustrated embodiment, the second wire electrode669can be disposed on an exterior portion of the shaft body proximal of the first ring electrode667. In one embodiment, the second wire electrode can be evenly spaced between the first ring electrode and the second ring electrode. In another embodiment, the second wire electrode can be spaced adjacent the first ring electrode and spaced farther from the second ring electrode. In yet another embodiment, the second wire electrode can be placed adjacent the second ring electrode and spaced farther from the first ring electrode. In yet another embodiment, the second wire electrode can be disposed proximal of the second ring electrode. In the illustrated embodiment, the second ring electrode can be disposed proximal of the first ring electrode and the second wire electrode. The second ring electrode can be electrically insulated from the second wire electrode.

FIG. 14depicts a partial side view of a catheter. The catheter can comprise a catheter shaft703and a tip electrode701. The tip electrode701can comprise a sidewall705and at least one slot707. The catheter shaft703can comprise a shaft body719, a first ring electrode717, a second ring electrode715and a first wire electrode709. The first wire electrode709can comprise a first wire713and a first insulation711. In the illustrated embodiment, the first wire electrode709can be disposed within the first ring electrode717. In one embodiment, the first wire electrode can be disposed around the entire outer circumference of the first ring electrode. In another embodiment, the first wire electrode can be disposed around a portion of the outer circumference of the first ring electrode. In yet another embodiment, the first wire electrode can be a longitudinally extending electrode. In this embodiment, a proximal end of the first wire electrode can be disposed in a proximal portion of the first ring electrode. A distal portion of the longitudinally extending first wire electrode can be disposed in a proximal portion of the first ring electrode. In yet another embodiment, the first wire electrode can comprise a longitudinal electrode that passes through the first ring electrode. In this embodiment, a proximal end of the first wire electrode can be disposed proximal a proximal end of a proximal end of the first ring electrode. A distal portion of the longitudinally extending first wire electrode can be disposed distal of a distal end of the first ring electrode. In yet another embodiment, the catheter can further comprise a second wire electrode. The second wire electrode can be disposed on one of the tip electrode, the catheter body, the first ring electrode, and/or the second ring electrode. In another embodiment, the catheter can comprise a plurality of wire electrodes. In one embodiment, a plurality of wire electrodes can be disposed on a single or multiple ring electrodes. In one embodiment, a plurality of longitudinally extending wire electrodes can be disposed on a ring electrode.

FIG. 15depicts a side view of another embodiment of a wire electrode753. The wire electrode753can be disposed on a catheter shaft751. The catheter shaft751can comprise a shaft body755and a wire electrode753. In the illustrated embodiment, the wire electrode753can comprise a wire757and an insulation (not shown). The wire can wrap around an exterior surface of the shaft body multiple times. In one embodiment, the wire electrode can form a coil around an outer surface of the shaft body. In one embodiment, a single loop of the wire of the wire electrode can be in contact with other loops of the wire that are located proximal or distal of the single loop of wire along the shaft body. In another embodiment, a single loop of the wire of the wire electrode can be spaced from other loops of the wire electrode that are located proximal or distal of the single loop of wire along the shaft body. The wire electrode depicted inFIG. 15can be wound around the shaft body a single time, two times, three times, or more. The number of tunings of the wire electrode and the spacing between the loops of the wire electrode can vary depending on the design of the catheter. The longitudinal length of the wire electrode, the number of loops in the electrode, and the spacing between adjacent loops of the electrode can be changed depending on the desired flexibility of the catheter shaft, the energy being delivered or received to the wire electrode, or for other circumstances as would be known to one of ordinary skill in the art. Further, in some embodiments, the wire electrode can comprise a wire that is free of insulation in a portion of the electrode that is wrapped around the catheter shaft. In this embodiment, an interior portion of the wire electrode can comprise an insulation that can electrically and/or thermally insulate an interior portion of the wire electrode from other components within the shaft body. In one embodiment, an portion of the wire electrode within the shaft body can comprise a wire conductor, as described throughout this application.

FIG. 16depicts a close-up cross-sectional view of a catheter shaft775. The catheter shaft775can comprise a shaft body791and a wire electrode777. The wire electrode777can comprise a wire781, an insulation785, and a wire conductor787. The shaft body791can comprise a proximal wall783and a distal wall779. The proximal wall783and the distal wall779can define a through hole789. In one embodiment, the through hole can comprise a circular cut-out bounded by the shaft body. In other embodiments, the through hole can comprise other shaped voids within the shaft body. The through hole789can be defined in a size and shape to allow the wire electrode777and the insulation785to pass from an interior portion of the catheter shaft795to an exterior portion of the catheter shaft795. In one embodiment, after passing from an interior portion of the catheter shaft795, the wire electrode777can be disposed within a groove within the shaft body791as described throughout the application. After being coupled to the groove or channel as described herein, the wire electrode can be ground or otherwise processed to reduce the wire electrode to a height of the surrounding surface. In the illustrated embodiment, the wire conductor787can be coupled to the wire781. The wire conductor787can be used and/or configured to deliver electrical signals to and/or from the wire781of the wire electrode777to a system or connector external of the catheter shaft775. In one embodiment, the wire conductor can comprise an insulation to insulate any signals being transferred by the wire conductor from outside interference or from interfering with other components within the catheter shaft. In one embodiment, the wire conductor can comprise the same material as the wire. In other embodiments, the wire conductor can comprise the same material as the wire, but can comprise a different shape. In yet another embodiment, the wire conductor can comprise a different material than the wire and can be the same or different shape than the wire. In some embodiments, the wire conductor can be integral to the wire. In yet other embodiments, the wire conductor can be coupled to the wire through a conductive glue, bonded, welded, soldered, fused, or otherwise secured.

FIGS. 17A and 17Bdepict a side view and an end view of one embodiment of a tip electrode801. The tip electrode801can comprise a distal end807, a tip surface803, and a plurality of wire electrodes805. The plurality of wire electrodes805can each run longitudinally from a proximal portion of the tip electrode801to a distal portion of the tip electrode801. In one embodiment, each of the plurality of wire electrodes805can be evenly spaced from each of the other wire electrodes around an outer circumference of the tip electrode801. In one embodiment, each of the plurality of wire electrodes can individually receive or deliver energy, independent of any neighboring wire electrodes. In another embodiment, energy can be delivered or received from a subset or all of the plurality of wire electrodes as a group. In the illustrated embodiment, each of the plurality of wire electrodes terminates prior to a distal end of the tip electrode. In one embodiment, one or more of the plurality of wire electrodes can terminate at the distal tip. In another embodiment, at least one of the plurality of wire electrodes can extend pass the distal end of the tip electrode and extend to the opposite side of the tip electrode.

FIG. 18depicts a side view of a tip electrode851contacting a tissue853. The tip electrode851can comprise a tip surface857and a wire electrode855. The wire electrode855can comprise a helical pattern around the tip electrode851. The tissue853can comprise a plurality of lesions859. The plurality of lesions859can be created when the tip electrode851contacts the tissue853and energy is delivered by the wire electrode855. In one embodiment, the wire electrode can comprise a plurality of wire electrodes. In one embodiment, an individual wire electrode can comprise one turn on the tip electrode. The tip electrode can comprise multiple wire electrodes separated from each other. In this embodiment, energy can be passed between two wire electrodes. When energy is passed between two of the wire electrodes on the tip electrode, lesion formation within the tissue can be controlled. In another embodiment, energy can be delivered by one or more of the wire electrodes and received by the tip surface of the tip electrode. In another embodiment, energy can be delivered by the tip surface of the tip electrode and received by one or more of the wire electrodes. As the wire electrode is electrically insulated from the tip surface, the energy delivered passes through the tissue before being received by a separate component of the tip electrode or external device.

FIG. 19depicts a side view of a tip electrode901. The tip electrode901comprises a tip surface909, a first axial wire electrode903, a second axial wire electrode905, a third axial wire electrode907, a longitudinal wire electrode913, and a slanted wire electrode911. As shown in the illustrated embodiment, a tip electrode according to the disclosure can comprise multiple wire electrodes of differing lengths and orientations. Further, different wire electrodes can overlap one another and be electrically insulated from the other wire electrodes and the tip surface. While the illustrated embodiment depicts a set of electrodes, various orientations, lengths, and wire sizes can be incorporated into a single tip electrode using the wire electrodes described throughout this application.

FIG. 20depicts an isometric side view of one embodiment of a wire electrode961. The wire electrode961can comprise a wire965and an insulation963. In the illustrated embodiment, the wire electrode can comprise a circular cross section. The wire electrode can be used in a variety of uses as described throughout this application. Further, a proximal portion of the wire electrode can comprise a wire electrode conductor as described herein.

FIG. 21depicts an isometric side view of another embodiment of a wire electrode951. The wire electrode951can comprise a wire955and an insulation953. In the illustrated embodiment, the wire electrode can comprise a rectangular cross section. In this embodiment, a first set of opposing sides can be longer than a second set of opposing sides. The wire electrode can be used in a variety of uses as described throughout this application. Further, a proximal portion of the wire electrode can comprise a wire electrode conductor as described herein.

FIG. 22depicts a close-up, cross-sectional view of an electrode1001. The electrode1001comprises an electrode outer surface1005, a channel1007, and a wire electrode1003. The wire electrode1003can comprise a wire1009and an insulation1011. The channel1007can comprise a depression within the electrode outer surface1005. The channel1007can be sized and shaped to fit a portion of the wire electrode1003within the channel1007. In the illustrated embodiment, the channel1007can comprise a hemi-spherical shape. The insulation1011of the wire electrode1003can electrically isolate the wire1009from the electrode outer surface1005.

FIG. 23depicts a close-up, cross-sectional view of an electrode1051. The electrode1051comprises an electrode outer surface1055, a channel1057, and a wire electrode1053. The wire electrode1053can comprise a wire1059and an insulation1061. The channel1057can comprise a depression within the electrode outer surface1055. The channel1057can be sized and shaped to fit a portion of the wire electrode1053within the channel1057. In the illustrated embodiment, the channel1057can comprise a rectangular shape. The insulation1061of the wire electrode1053can electrically isolate the wire1059from the electrode outer surface1055.

While a hemi-spherical and rectangular shape of a channel are illustrated inFIGS. 22 and 23, other shapes can be provided for placement of a wire electrode. Further, other portions of a catheter can comprise channels for containing a wire electrode. In various embodiments, the tip electrode, ring electrodes, catheter shaft, or other portions of a catheter can comprise channels for wire electrodes. In one embodiment, the channel can be created by drilling, sanding, or otherwise removing material from a surface of an electrode to create a channel. In another embodiment, a channel can be created when the tip is initially formed. In this instance a mold or other device can be used to form the channel. In one embodiment, when the wire electrode is disposed within a catheter shaft, the channel can be micro-molded by the wire electrode. In yet other embodiments, the channel can be formed through reflowing a catheter shaft after placement of the wire electrode. In one embodiment, the wire can be ground or otherwise processed to bring the height of the wire electrode to the level of the surrounding catheter shaft.