Neuromodulation catheter having stimulation and ablation electrodes

Abstract

A neuromodulation catheter includes an elongate body, a plurality of ablation electrodes along the elongate body, a plurality of stimulation electrodes along the elongate body, and filter circuitry electrically coupled to the plurality of ablation electrodes and the plurality of stimulation electrodes. The filter circuitry may be configured to receive an electrical signal including a stimulation signal and an ablation signal. The stimulation signal includes a first frequency or frequency range and the ablation signal includes a second frequency or frequency range that is greater than the first frequency or frequency range. The filter circuitry is further configured to filter the stimulation signal from the electrical signal and deliver the stimulation signal to the plurality of stimulation electrodes. The filter circuitry is further configured to filter the ablation signal from the electrical signal and deliver the ablation signal to the plurality of ablation electrodes.

Description

NEUROMODULATION CATHETER HAVING STIMULATION AND ABLATIONELECTRODES

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 624,570, filed January 24, 2024, the entire content of which is incorporated herein by reference.TECHNICAL FIELD

[0002] The present disclosure generally relates to neuromodulation.BACKGROUND

[0003] A denervation procedure may include ablating target nerves, for example, by delivering ablative energy to a target site via a catheter. For example, renal denervation may include ablating renal nerves.SUMMARY

[0004] In general, the present disclosure describes neuromodulation catheters including stimulation and ablation electrodes.

[0005] Nerve electrical stimulation may be used to monitor and guide a denervation procedure. For example, a physiological response to electrical stimulation may indicate whether further denervation is required, or if sufficient denervation has been achieved to attenuate neural traffic. Thus, the effect of electrical stimulation can be compared before and after a denervation session to determine whether further denervation (e.g., ablation) is needed. However, conducting electrical stimulation before and after denervation in different sessions can extend overall procedural complexity and time, and increase the number of steps required for the procedure. For example, different devices or systems may be needed for delivering electrical stimulation and ablation, or devices or systems may require a relatively high number of parts, complex wiring, or present other complexities.

[0006] In some examples, devices, systems, and techniques according to the present disclosure deliver ablative energy and stimulation using a combined apparatus. For example, an example neuromodulation catheter may include stimulation and ablation electrodes controlled by different components of an electrical signal. In some examples, wiring is relatively simpler compared to a catheter in which stimulation and ablation electrodes receiveelectrical signals from different wires or based on different electrical signals. Further, denervation and electrical stimulation may be combined in a single session, for example, by modifying the denervation profile.

[0007] In some examples, an example catheter includes a neuromodulation catheter including an elongate body, a plurality of ablation electrodes along the elongate body, a plurality of stimulation electrodes along the elongate body, and filter circuitry electrically coupled to the plurality of ablation electrodes and the plurality of stimulation electrodes. The filter circuitry may be configured to receive an electrical signal including a stimulation signal and an ablation signal. The stimulation signal includes a first frequency or frequency range and the ablation signal includes a second frequency or frequency range that is greater than the first frequency or frequency range. The filter circuitry is further configured to filter the stimulation signal from the electrical signal and deliver the stimulation signal to the plurality of stimulation electrodes. The filter circuitry is further configured to filter the ablation signal from the electrical signal and deliver the ablation signal to the plurality of ablation electrodes.

[0008] In some examples, an example system includes the neuromodulation catheter and a controller. The controller may be configured to generate the electrical signal comprising the ablation signal to be delivered by the plurality of ablation electrodes and the stimulation signal to be delivered by the plurality of stimulation electrodes.

[0009] In some examples, an example technique includes sending, by processing circuitry, the electrical signal to the neuromodulation catheter. The technique may further include filtering, by the filter block, the electrical signal into the ablation signal and the stimulation signal. The technique may further include delivering, by the plurality of ablation electrodes, the ablation signal to a target site. The technique may further include delivering, by the plurality of stimulation electrodes, the stimulation signal to the target site.

[0010] Further disclosed herein is a neuromodulation catheter that includes an elongate body, a plurality of ablation electrodes along the elongate body, a plurality of stimulation electrodes along the elongate body, and filter circuitry electrically coupled to the plurality of ablation electrodes and the plurality of stimulation electrodes, wherein the filter circuitry may be configured to receive an electrical signal including a stimulation signal and an ablation signal, wherein the stimulation signal includes a first frequency or frequency range and the ablation signal includes a second frequency or frequency range that is greater than the first frequency or frequency range, wherein the filter circuitry is further configured to filter the stimulation signal from the electrical signal and deliver the stimulation signal to the pluralityof stimulation electrodes, and wherein the filter circuitry is further configured to filter the ablation signal from the electrical signal and deliver the ablation signal to the plurality of ablation electrodes.

[0011] The details of one or more examples of the techniques of this disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the techniques will be apparent from the description and drawings, and from the claims.BRIEF DESCRIPTION OF DRAWINGS

[0012] FIG. 1 A is a diagram illustrating an example system including a catheter configured to deliver neuromodulation therapy, a computing device, and a controller.

[0013] FIG. IB is a diagram illustrating a magnified partial view of the catheter of FIG.1 A including filter circuitry.

[0014] FIG. 1C is a diagram illustrating a cross-sectional view along plane A- A of the catheter of FIG. IB.

[0015] FIG. 2A is a diagram illustrating a side view of an example catheter configured to deliver neuromodulation therapy, the catheter including filter circuitry including a plurality of filter blocks.

[0016] FIG. 2B is a diagram illustrating a magnified partial view of the catheter of FIG. 2A including two neuromodulation blocks.

[0017] FIG. 3 is a timing diagram illustrating comparing two example schemes for delivering ablation and stimulation for neuromodulation.

[0018] FIG. 4 is a timing diagram illustrating comparing an example scheme for delivering ablation and stimulation for neuromodulation including separate ablation and stimulation sessions.

[0019] FIG. 5 is a timing diagram illustrating comparing an example scheme for delivering ablation and stimulation for neuromodulation including combining ablation and stimulation sessions.

[0020] FIG. 6 is a block diagram illustrating an example configuration of the computing device of FIG. 1.

[0021] FIG. 7 is a flow diagram illustrating an example technique for neuromodulation.

[0022] FIG. 8 illustrates an example technique for accessing a renal artery and modulating renal nerves with a neuromodulation catheter in accordance with some examples of the present disclosure.

[0023] FIG. 9 is a conceptual illustration of an example sympathetic nervous system (SNS) illustrating how the brain communicated with the body via the SNS.

[0024] FIG. 10 is an enlarged anatomic view of nerves innervating a left kidney to form the renal plexus surrounding the left renal artery.

[0025] FIG. 11 is an anatomic view of a human body depicting neural efferent and afferent communication between the brain and kidneys.

[0026] FIG. 12 is a conceptual view of a human body depicting neural efferent and afferent communication between the brain and kidneys.

[0027] FIG. 13 is an anatomic view of the arterial vasculature of a human.

[0028] FIG. 14 is an anatomic view of the venous vasculature of a human.DETAILED DESCRIPTION

[0029] The present disclosure describes neuromodulation catheters including stimulation and ablation electrodes.

[0030] As used herein, the terms “distal” and “proximal” define a position or direction with respect to the treating clinician or clinician’s control device (e.g., a handle assembly). “Distal” or “distally” can refer to a position distant from or in a direction away from the clinician or clinician’s control device. “Proximal” and “proximally” can refer to a position near or in a direction towards the clinician or clinician’s control device.

[0031] Separate sessions of denervation, followed by electrical stimulation to monitor the progress or effect of denervation, may require relatively longer overall therapy times. In some example techniques according to the present disclosure, denervation and electrical stimulation are combined in a single session. For example, a denervation profile is modified to accommodate electrical stimulation within an initial overall denervation session. For example, an ablation waveform may be split into two shorter waveforms, and a stimulation waveform may be introduced between the shorter ablation waveforms, compared to a relatively longer ablation waveform. Further, a period of post-ablation impedance measurement may be shortened to accommodate an additional post-ablation stimulation.

[0032] However, alternating ablation and stimulation may lead to electrode polarization on the electrodes that are used to deliver both ablation and stimulation. In accordance with examples described in this disclosure, to control and reduce electrode polarization, in some examples, a neuromodulation catheter may include spaced-apart ablation and stimulation electrodes. Compared to delivering ablation and stimulation via the same electrodes, usingdifferent electrodes for delivering ablation and stimulation may reduce polarization. An ablation signal (for example, a radio-frequency ablation signal) typically has a relatively higher frequency, while an electrical stimulation signal typically has a relatively lower frequency that the ablation signal. In some examples, the ablation signal includes an alternating current (AC) component (e.g, in a range from 100 kHz to 1 MHz), while the electrical stimulation signal includes a direct current (DC) component, or a component have a relatively low frequency (e.g., in a range from 0 to 100 Hz, or from 0 to 200 Hz). The ablation signal is configured to cause denervation (e.g., ablation of nerves) to attenuate nerve activity. The stimulation signal is not configured to cause denervation, but is configured to stimulate nerves. In response to the stimulation signal, a target site may generate nerve activity, unless the target site is substantially or completely denervated.

[0033] The electrodes may include ablation electrodes and stimulation electrodes positioned along the catheter. In some examples, pairs of electrodes positioned along the catheter may each include an ablation electrode and a stimulation electrode. The catheter may further include filter circuitry configured to separate an ablation signal and a stimulation signal from a single electrical signal, and deliver the ablation signal and the stimulation signal components to the ablation and stimulation electrodes respectively. The stimulation signal may include a first frequency or frequency range and the ablation signal may include a second frequency or frequency range that is greater than the first frequency or frequency range. For example, the ablation signal may include a relatively higher frequency signal (an AC signal), while the stimulation signal may include a relatively lower frequency signal or a DC signal. The stimulation signal may include any suitable waveform, for example, a square wave, or a sine wave. The filter circuitry may include one or more filter blocks configured to separate the ablation signal and the stimulation signal from the single electrical signal, and deliver the ablation signal to ablation electrodes, and the stimulation signal to stimulation electrode. Using such filtering may reduce the complexity of wiring, for example, by allowing the same wire to carry a combined electrical signal including the ablation signal and the stimulation signal, instead of using separate wiring or electrical paths along the catheter to carry and deliver the ablation signal and the stimulation signal separately to ablation electrodes and stimulation electrodes respectively.

[0034] In some examples, the filter circuitry may be mounted to a flexible board. In some examples, the filter circuitry includes a plurality of capacitors. The flexible board may be curved or wrapped about an elongate body (e.g. a shaft), a lumen, a tubing, or a jacket of thecatheter. The flexible board may be positioned at a proximal portion of the catheter, spaced from the electrodes. Alternatively, individual flexible boards may be positioned adjacent respective electrodes along the shaft. Using flexible boards may promote compactness of the neuromodulation catheter, for example, by allowing at least partially wrapping or conformance to a geometry of an elongate body or other components of the catheter.

[0035] FIG. 1 A is a diagram illustrating an example system including a catheter 12 configured to deliver neuromodulation therapy, a computing device 14, and a controller 16. Catheter 12 is also referred to as neuromodulation catheter 12. Computing device 14 may be configured to send a control signal to controller 16 or otherwise control the operation of one or both of catheter 12 or controller 16. In some examples, the control signal sent by computing device 14 to controller 16 is configured to cause controller 16 to, based on the control signal received from computing device 14, generate an electrical signal. Controller 16 may generate the electrical signal sent to catheter 12 to cause catheter 12 to deliver neuromodulation therapy. For example, the neuromodulation therapy may include renal neuromodulation, hepatic neuromodulation, or any other neuromodulation therapy.

[0036] In general, the devices, systems, and techniques described herein may be used to perform neuromodulation and stimulation from within any suitable anatomical lumen that has nerves adjacent to the anatomical lumen. Example anatomical lumens include the celiac trunk and its branches (including the common hepatic artery and its branches (including the gastroduodenal artery and its branches, the right gastric artery and its branches, and the proper hepatic artery and its branches), the left gastric artery and its branches, and the splenic artery and its branches), the superior mesenteric artery and its branches, the gonadal artery and its branches, the inferior mesenteric artery and its branches, and the like. Further, although the disclosure primarily describes neuromodulation from within one or more arteries, the devices, systems, and techniques of the disclosure also may be applied to neuromodulation from within one or more veins, such as a renal vein and its branches, a hepatic vein and its branches, an intercostal vein and its branches, or the like.

[0037] In some implementations, the devices, systems, and techniques described herein may be used to perform neuromodulation and stimulation from within two or more anatomical lumens, e.g., in the renal arteries and the common hepatic artery, or any other combination of two or more anatomical lumens, either simultaneously or sequentially. In addition, the systems, devices, and methods described herein may be useful in conjunction withneuromodulation within a body lumen other than a vessel, for extravascular neuromodulation and / or for use in conjunction with therapies other than neuromodulation.

[0038] Catheter 12 includes a handle 20 and an elongate body 22 attached to handle 20. That is, handle 20 is positioned at a proximal portion of elongate body 22. Elongate body 22 may have any suitable outer diameter, and the diameter can be constant along the length of elongate body 22 or may vary along the length of elongate body 22. In some examples, elongate body 22 may be 2, 3, 4, 5, 6, or 7 French or another suitable size. Elongate body 22 extends along a central longitudinal axis L, and includes a distal portion 22A and a proximal portion 22B. Distal portion 22A includes an expandable portion 24. Expandable portion 24 is configured to transform from a relatively low-profile configuration (shown in FIG. 1 A) to a radially expanded deployed configuration (not shown in FIG. 1 A), such as a spiral or helical configuration, or an expanded balloon configuration.

[0039] Catheter 12 includes a plurality of ablation electrodes 26, for example, disposed along elongate body 24. In the example shown in FIG. 1 A, the plurality of ablation electrodes 22 is disposed on expandable portion 24 of elongate body 22. Ablation electrodes 26 are configured to deliver therapy to tissue of a patient, for example, to modulate a target nerve of the patient.

[0040] Catheter 12 further includes a plurality of stimulation electrodes 28 along the elongate body. The plurality of stimulation electrodes 28 may be used to deliver stimulation to a target site, for example, before or after delivering denervation therapy. In some examples, the neural response to the stimulation, or the differences in neural responses to the stimulation before and after denervation may be indicative of effectiveness of denervation. Thus, a clinician may alternate delivery of stimulation with one or more sessions of delivery of denervation therapy, to gauge the progress and effectiveness of the denervation therapy. For example, at least one physiological parameter (for example, a blood pressure, a flow rate, or constriction in vasculature) may be measured and compared before and after delivering a stimulation signal, and a change in a magnitude of the at least one physiological parameter may indicate attenuation of neural traffic associated with the nerve. For example, low change or an absence of change in the physiological parameter may indicate that the nerve is ablated and that no further ablation is necessary. Likewise, a change in the physiological parameter greater than a predetermined threshold may indicate that further ablation is required.

[0041] The plurality of ablation electrodes 26 and the plurality of stimulation electrodes 28 may be each positioned along distal portion 22A, for example, along expandable portion 24.

[0042] Catheter 12 may thus deliver denervation therapy via the plurality of ablation electrodes 26, and computing device 14 or controller 16 may monitor denervation by delivering stimulation via the plurality of stimulation electrodes 28. One or both of ablation electrodes 26 and stimulation electrodes 28 may include ring electrodes surrounding at least a portion of elongate body 22. Ablation electrodes 26 and stimulation electrodes 28 may be identical, similar, or different in composition or geometry. For example, ablation electrodes 26 may be similar to each other, or differ from each other. Stimulation electrodes 28 may be similar to each other, or differ from each other. One or more of ablation electrodes 26 may be similar to differ from one or more of stimulation electrodes 28. The plurality of ablation electrodes 26 may be interleaved with the plurality of stimulation electrodes 28, as shown in FIG. 1 A. In some examples, for interleaving, each ablation electrode of the plurality of ablation electrodes 26 is distal to a respective stimulation electrode of the plurality of stimulation electrodes 28, as shown in FIG. 1 A. In other examples, for interleaving, each ablation electrode of the plurality of ablation electrodes 26 is proximal to a respective stimulation electrode of the plurality of stimulation electrodes 28.

[0043] Each ablation electrode of the plurality of ablation electrodes 26 may have a same ablation electrode length along longitudinal axis L of elongate body 22. Each stimulation electrode of the plurality of stimulation electrodes 28 may have a same stimulation electrode length along longitudinal axis L. In some examples, the stimulation electrode length is less than the ablation electrode length along longitudinal axis L.

[0044] In some examples, ablation electrodes 26 include gold. For example, gold may promote thermal dissipation and reduce thermal buildup in course of ablation. In some examples, stimulation electrodes 28 include iridium oxide. For example, iridium oxide may have a high electrical conductivity.

[0045] Catheter 12 may be connected to controller 16 (e.g., a therapy delivery device). Controller 16 may include control circuitry and therapy source (for example, an electrical signal generator, or the like; not shown in FIG. 1 A) via at least one electrical conductor and / or at least one lumen defined by handle 20 and elongate body 22. Although FIG. 1 A illustrates catheter 12 as having four units in each of the plurality of ablation electrodes 26 and the plurality of stimulation electrodes 28, other example catheters may include one, two, three,five, or more respective units of ablation electrodes 26 or stimulation electrodes 28. In some examples, each respective ablation electrode of plurality of ablation electrodes 26 is associated with a respective stimulation electrode of the plurality of stimulation electrodes 28.

[0046] Each ablation electrode of the plurality of ablation electrodes 26 may be coupled to a respective thermocouple. For example, controller 16 may sense a respective temperature of each ablation electrode via the respective thermocouple. In some examples, controller 16 may terminate ablation therapy in response to a temperature sensed by a thermocouple, for example, to avoid excessive heating of catheter 12 or neighboring tissue.

[0047] Distal portion 22A of elongate body 22 is configured to be advanced within an anatomical lumen of a human patient to locate plurality of ablation electrodes 26 at a target tissue site within or otherwise proximate to the anatomical lumen. For example, elongate body 22 may be configured to position distal portion 22A within a blood vessel, a ureter, a urethra, a duct, an airway, or another naturally occurring lumen within the human body. The examples described herein focus on the anatomical lumen being a blood vessel, such as a renal vessel, but it will be understood that similar techniques may be used with other anatomical lumens.

[0048] Catheter 12 can be configured for delivery to a target tissue site within vasculature of a patient via a guide member, which can include, for example, one or more of a guidewire or an outer sheath. In certain examples, intravascular delivery of distal portion 22A includes percutaneously inserting a guidewire (not shown in FIG. 1 A) into a vessel of a patient and moving elongate body 22 (for example, at least expandable portion 24) along the guidewire until expandable portion 24 reaches a target tissue site (for example, a renal artery). For example, distal portion 22A of elongate body 22 may define a lumen configured to receive a guidewire for delivery of expandable portion 24 to a target tissue site using over-the-wire (OTW) or rapid exchange (RX) techniques. In other examples, catheter 12 can be a steerable or non-steerable device configured for use without a guidewire. In still other examples, catheter 12 can be configured for delivery via an inner lumen of a guide member, for example, a guide catheter, an outer sheath (not shown in FIG. 1 A), or other guide device.

[0049] A distal end of elongate body 22 defines distal tip 30. Distal tip 30 is configured to facilitate navigation of distal portion 22A within the vasculature of the patient to a blood vessel. In some examples, distal tip 30 may be atraumatic, for example, to resist or avoid puncturing a vessel of a blood vessel during navigation of distal portion 22A within the blood vessel.

[0050] In the example illustrated in FIG. 1 A, catheter 12 is in a relatively low-profile delivery configuration, in which distal portion 22A defines a relatively smaller radial extent (a relatively low-profile, such as a relatively linear configuration) relative to an expanded (also referred to as a radially expanded and / or deployed) configuration in which expandable portion 24 of distal portion 22A defines a relatively larger radial extent. In some examples, the radial extent is measured in a direction orthogonal to central longitudinal axis L. Distal portion 22A may be delivered through vasculature of the patient to the target tissue site in the low-profile configuration. In some examples, expandable portion 24 is configured to self-expand within a blood vessel of a patient, e.g., via a shape-memory element (e.g., a shape memory tube or a hollow helical strand) of elongate body 22. In some examples, expandable portion extends along a straight line aligned with longitudinal axis L in the relatively low-profile configuration shown in FIG. 1 A. Expandable portion 24 may be constrained or restrained in the low-profile configuration by a guide member. The clinician may retract the guide member proximally relative to expandable portion 24 to unconstrain expandable portion 24 and cause or allow expandable portion 24 to transform from the low-profile configuration to an expanded configuration. Thus, expandable portion 24 may be configured to radially expand away from the straight line to the expanded configuration.

[0051] In some examples, in an expanded configuration, expandable portion 24 defines a loop, a helix, or a spiral shape, or a basket, or a stent-like configuration. In the expanded configuration, expandable portion 24 is configured to position one or more electrodes of plurality of ablation electrodes 26 near a vessel wall, for example, in apposition with the vessel wall.

[0052] In some examples, expandable portion 24 may be expanded or may self-expand as a result of proximal retraction of a guide member from distal portion 22A. The clinician may retract the guide member to a location along distal portion 22A proximal to expandable portion 24 to cause or allow expandable portion 24 to expand. In the expanded configuration, expandable portion 24 may place at least one electrode at a first location relative to the vessel wall, for example, corresponding to a first rotational location. A clinician may control a therapy delivery device to deliver, provide, or facilitate neuromodulation therapy at the target tissue site, for example, through the vessel wall at the target tissue site to target tissue adjacent to the blood vessel. The neuromodulation therapy may include, but is not limited to, radiofrequency (RF) energy, or the like.

[0053] The clinician may rotate handle 20, or otherwise proximal portion 22B, to apply a torque to distal portion 22A and cause expandable portion 24 to rotate about central longitudinal axis L from the first rotational location to a second rotational location. For example, the application of torque from handle 20 or proximal portion 22B to expandable portion 24 may cause expandable portion 24 to rotate about longitudinal axis L, for example, in a same direction as the torque. The clinician may control system 10 to deliver ablation therapy or stimulation at the second rotational location, or after further successive rotational locations of expandable portion 24.

[0054] Catheter 12 further includes filter circuitry 32 electrically coupled to the plurality of ablation electrodes 26 and the plurality of stimulation electrodes 28. Filter circuitry 32 may include a single filter block, as shown in FIG. 1 A, or a plurality of filter blocks, as described with reference to FIGS. 2 A and 2B.

[0055] FIG. IB is a diagram illustrating a magnified partial view of catheter 12 of FIG. 1 A including filter circuitry 32. Filter circuitry 32 is configured to receive an electrical signal, for example, from controller 16. Filter circuitry 32 may be further configured to filter an ablation signal from the electrical signal and deliver the ablation signal to the plurality of ablation electrodes 26. Filter circuitry 32 may be further configured to filter a stimulation signal from the electrical signal and deliver the stimulation signal to the plurality of stimulation electrodes 28. The stimulation signal may include a first frequency or frequency range and the ablation signal may include a second frequency or frequency range that is greater than the first frequency or frequency range. In some examples, the first frequency is zero, and the stimulation signal is a direct current (DC) component of the electrical signal. The second frequency may be non-zero, and the ablation signal may be an alternating current (AC) component of the electrical signal. Thus, the ablation signal may include a relatively higher frequency signal (an AC signal), while the stimulation signal may include a relatively lower frequency signal or a DC signal.

[0056] Filter circuitry 32 may be coupled to a signal wire 34, which may be configured to send the electrical signal from controller 16 to catheter 12. Thus, filter circuitry 32 may be used to separate appropriate signals (the ablation signal and the stimulation signal) from the electrical signal sent along single signal wire 34. In some examples, filter circuitry 32 is configured to filter a first signal having a first frequency (e.g., in a range from 0 Hz to 200 Hz) or a DC signal as the stimulation signal. Filter circuitry 32 may be further configured to filter a second signal having a second frequency higher than the first frequency (e.g., in arange from 100 kHz to 1 MHz) as the ablation signal. However, filter circuitry 32 may be configured to filter any signal including a first predetermined frequency band as the stimulation signal and any another signal including a second predetermined frequency band (for example, a relatively higher frequency band compared to the first frequency) as the ablation signal. In some examples, the stimulation signal includes a DC signal, or an AC signal having a relatively low frequency (e.g., in a range of from 0 to 100 Hz, or from 0 to 200 Hz).

[0057] Filter circuitry 32 may be positioned along distal portion 22A, as shown in FIGS. 1 A and IB. For example, filter circuitry 32 may be positioned adjacent to plurality of ablation electrodes 26 and the plurality of stimulation electrodes 28. In other examples, filter circuitry 32 is positioned along the proximal portion 22B. For example, filter circuitry 32 may be spaced from plurality of ablation electrodes 26 and the plurality of stimulation electrodes 28. In other examples, filter circuitry 32 may be spaced from elongate body 22, for example, being positioned along handle 20, or spaced from catheter 12. For example, filter circuitry 32 may be coupled between controller 16 and catheter 12, or be positioned in controller 16.

[0058] Filter circuitry 32 may include circuitry including at least one capacitor. In some examples, the circuitry includes at least one resistor-capacitor (RC) circuit. In some examples, filter circuitry 32 is coupled to at least one ablation electrode of plurality of ablation electrodes 26 by an ablation signal wire 36. For example, filter circuitry 32 may include an ablation filter circuitry 33A configured to separate an ablation signal from an electrical signal received by filter circuitry 32 and deliver the ablation signal to the at least one ablation electrode of plurality of ablation electrodes 26 by ablation signal wire 36. In some examples, filter circuitry is coupled to at least one stimulation electrode of plurality of stimulation electrodes 28 by a stimulation signal wire 38. For example, filter circuitry 32 may include a stimulation filter circuitry 33B configured to separate a stimulation signal from the electrical signal received by filter circuitry 32 and deliver the stimulation signal to the at least one ablation electrode of plurality of ablation electrodes 26 by stimulation signal wire 38. In some examples, the at least one ablation electrode coupled to ablation signal wire 36 is coupled, in turn, to other ablation electrodes, by a series or parallel connection. Likewise, the at least one stimulation electrode coupled to stimulation signal wire 38 may be coupled, in turn, to other stimulation electrodes, by a series or parallel connection. Thus, filter circuitry 32 need not be directly connected to each electrode of plurality of ablation electrodes 26 or ofplurality of stimulation electrodes 28, thus reducing wiring complexity compared to an arrangement in which each electrode is individually coupled by respective a signaling wire to controller 16. However, in other examples, filter circuitry 32 may be coupled to more than one ablation electrode, or to more than one stimulation electrode. Ablation signal wire 36 may be coupled to at least one capacitor having a relatively low capacitance of filter circuitry 32, for example, configured to block a DC component from the electrical signal to generate the ablation signal. In some examples, ablation filter circuitry 33A may include the at least one capacitor having a relatively low capacitance. For example, the at least one capacitor in ablation filter circuitry 33 A may block a stimulation signal, such that when the stimulation signal is delivered through signal wire 34, the stimulation signal is only transmitted through stimulation signal wire 38, and blocked from ablation signal wire 36. In some examples, the at least one capacitor is not configured to block an ablation signal, and when the ablation signal is delivered through signal wire 34, the ablation signal may be transmitted through both ablation signal wire 36 and stimulation signal wire 38. Stimulation signal wire 38 may be coupled to at least one capacitor having a relatively high capacitance of filter circuitry 32, for example, configured to block an AC component from the electrical signal to generate the stimulation signal. In some examples, stimulation filter circuitry 33B may include the at least one capacitor having the relatively high capacitance. In some examples, a DC bias may be applied to the ablation electrodes 26. For example, controller 16 may include a DC source configured to apply the DC bias to ablation electrodes 26. In some examples, stimulation filter circuitry 33B may include at least one inductor. For example, the at least one inductor may be configured to block an ablation signal from stimulation signal wire 38, such that when the ablation signal is delivered through signal wire 34, the ablation signal is transmitted substantially only through ablation signal wire 36. The at least one inductor may have a relatively low inductance. Filter circuitry 32 may include one or both of ablation filter circuitry 33A or stimulation filter circuitry 33B, or may exclude ablation filter circuitry 33A and stimulation filter circuitry 33B.

[0059] Filter circuitry 32 may be proximal to the plurality of ablation electrodes 26 and to the plurality of stimulation electrodes 28, as shown in FIGS. 1 A and IB. In some examples, filter circuitry 32, at least one ablation electrode, and at least one stimulation electrode may be secured within a single housing.

[0060] In some examples, filter circuitry 32 is formed on or secured to a flexible board 44, as described with reference to FIG. 1C. FIG. 1C is a diagram illustrating a cross-sectionalview along plane A-A of catheter 12 of FIG. IB. For example, flexible board 44 may be wrapped about elongate body 22, wrapped about a jacket 46, or embedded about a lumen 48 defined by the elongate body. In some examples, flexible board 44 may occupy an interstitial region between two layers of catheter 12. In other examples, flexible board 44 may be embedded within a matrix of a layer. In some examples, flexible board 44 comprises a polymeric substrate, for example, a silicone, or a polyimide. In some examples, flexible board 44 is substantially translucent or transparent. Wiring or conductive pathways, or electrical components of filter circuitry 32, may be embedded or defined within flexible board 44. For example, one or more of a capacitor, a resistor, an inductor, or a conductive trace may be embedded within a matrix of flexible board 44. Embedding one or more components within flexible board 44 may facilitate electrically isolating the components from a surrounding environment, or from each other.

[0061] In some examples, filter circuitry 32 includes a single filter block, for example, as shown in FIG. 1. In other examples, a catheter may include filtration circuitry including a plurality of filter blocks.

[0062] FIG. 2A is a diagram illustrating a side view of an example catheter 112 configured to deliver neuromodulation therapy, catheter 112 including a plurality of filter blocks 32. Catheter 112 is substantially similar to catheter 12 described with reference to FIGS. 1 A to 1C, but differing in that filter circuitry of catheter 112 includes a plurality of neuromodulation blocks 132. Each neuromodulation block of plurality of neuromodulation blocks 132 includes a respective ablation electrode 26, a respective stimulation electrode 28, and a respective filter block 32. Further, in catheter 112, a respective stimulation electrode 28 in each neuromodulation block 132 is distal to a respective ablation electrode 26 (opposite the arrangement shown in FIG. 1 A with reference to catheter 12).

[0063] FIG. 2B is a diagram illustrating a magnified partial view of catheter 112 of FIG. 2A including two neuromodulation blocks 132. As seen in FIG. 2B, a single signal wire 34 may be coupled to each filter block 32 in neuromodulation blocks 132, and each filter block 32 in turn may be coupled to a respective ablation electrode 26 and stimulation electrode 28 within a respective neuromodulation block 132. Thus, wiring complexity is reduced compared to an arrangement in which a single filter block is coupled to each ablation electrode 26 and stimulation electrode 28.

[0064] Thus, a plurality of filter blocks may include filter block 32. As seen in FIGS. 2 A and 2B, the plurality of filter blocks 32 may be interleaved with the plurality of ablationelectrodes 26 and the plurality of stimulation electrodes 28. In some examples, each filter block of the plurality of filter blocks 32 is positioned adjacent a respective ablation electrode of the plurality of ablation electrodes 26 or a respective stimulation electrode of the plurality of stimulation electrodes 28. Each filter block of the plurality of filter blocks 32 may be proximal to a respective ablation electrode of the plurality of ablation electrodes 26 and to a respective stimulation electrode of the plurality of stimulation electrodes 28. In some examples, each filter block of the plurality of filter blocks 32 is electrically coupled to a single signal wire 34 (also referred to as a control cable) extending along the elongate body to receive an electrical signal from a controller.

[0065] Turning back to FIG. 1 A, controller 16 may be configured to generate an electrical signal comprising the ablation signal configured to be delivered by the plurality of ablation electrodes 26 and the stimulation signal configured to be delivered by the plurality of stimulation electrodes 28. For example, controller 16 may include a generator 40 configured to generate the ablation signal and a stimulator 42 configured to generate the stimulation signal. Depending on the frequency components of the ablation signal or the stimulation signal, generator 40 or stimulator 42 may include one or both of an AC generator or a DC generator. In some examples, stimulator 42 includes circuitry configured to rectify an AC signal to generate a DC signal. For example, stimulator 42 may generate the stimulation signal including solely the DC signal. In other examples, one or both of the ablation signal or the stimulation signal may include an AC signal and a DC signal, but differ in the frequency band of the AC signal, or the amplitude of the DC signal. For example, the ablation signal may have a significantly higher frequency than the stimulation signal.

[0066] System 10, and / or catheters 12 or 112 may be used to deliver ablation and stimulation for neuromodulation according to any appropriate scheme.

[0067] FIG. 3 is a timing diagram illustrating comparing two example schemes for delivering ablation and stimulation for neuromodulation. In the upper scheme shown in FIG. 3, a first stimulation session (i.e., “Stimulate” in upper scheme of FIG. 3), a first ablation session (i.e., “Ablate” in upper scheme of FIG. 3), and a second stimulation session (i.e., “Confirm” in upper scheme of FIG. 3) each have a relatively long session period, leading to overall increased therapy session time, as further described with reference to FIG. 4. In the lower scheme, stimulation and ablation are more closely interleaved in time, with relatively shorter durations, leading to an overall reduced therapy session time, as further described with reference to FIG. 5.

[0068] FIG. 4 is a timing diagram illustrating comparing an example scheme for delivering ablation and stimulation for neuromodulation including separate ablation and stimulation sessions. In the scheme shown in FIG. 4, the ablation waveform is delivered in a single, relatively long session (e.g., 88 ms), followed by a relatively long impedance measurement session (e.g., 12 ms).

[0069] FIG. 5 is a timing diagram illustrating comparing an example scheme for delivering ablation and stimulation for neuromodulation including combining ablation and stimulation sessions. The scheme of FIG. 5 is achieved by modifying the scheme of FIG. 4 to split the ablation waveform into two shorter waveforms (“Ablation waveform A” and “Ablation waveform B” having shorter durations of time than the “Ablation waveform” of FIG. 4), and introduce a relatively short time of stimulation (“Stim”) between the split ablation waveforms A and B. Further, the impedance measurement is shortened in time (“Impedance meas ”), and a second stimulation is delivered after the shortened impedance measurement (“Stim”).

[0070] To reduce or prevent potential polarization effects arising from the modified scheme of FIG. 5, catheter 12 or catheter 112 may be used to deliver ablation and stimulation via different electrodes, while still having an acceptable complexity of wiring and electrical signals.

[0071] Thus, controller 16 may control catheter 12 or catheter 112 to deliver a neuromodulation therapy including interleaved ablation and stimulation of relatively shorter periods. In some examples, computing device 14 controls controller 16 to deliver ablation and stimulation via catheter 12 or catheter 112. For example, computing device 14 may be configured to generate and send a control signal to controller 16, and controller 16 may be configured to generate, based on the control signal, an electrical signal sent to catheter 12.

[0072] FIG. 6 is a block diagram illustrating an example configuration of computing device 14 of FIG. 1. In some examples, controller 16 may include computing device 14, or include one or more components described with reference to computing device 14, or otherwise perform functions described with reference to computing device 14. Computing device 14 may include a workstation, a tablet computer, a laptop computer, or a desktop computer.

[0073] As shown in the example of FIG. 6, computing device 14 includes processing circuitry 170, storage device 172, communication circuitry 174, and a user interface 176. While computing device 14 may be a stand-alone device as shown in FIG. 6, in otherexamples, computing device 14 may be any component or system that includes processing circuitry or other suitable computing environment for executing software instructions and, for example, need not necessarily include one or more elements shown in FIG. 6 (e.g., in some examples components such as storage device 172 may not be co-located or in the same housing or structure as other components).

[0074] Processing circuitry 170, in some examples, is configured to implement functionality and / or process instructions for execution within at least one computing device 14. For example, processing circuitry 170 may be capable of processing instructions, including at least one application 180, stored in storage device 172. Examples of processing circuitry 170, as well as other processors, processing circuitry, controllers, control circuitry, and the like, described herein, may include any combination of integrated circuitry, discrete logic circuitry, analog circuitry, such as one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), or field-programmable gate arrays (FPGAs). In some examples, processing circuitry 170 includes multiple components, such as any combination of one or more microprocessors, one or more DSPs, one or more ASICs, or one or more FPGAs, as well as other discrete or integrated logic circuitry, and / or analog circuitry.

[0075] Storage device 172 (which can also be referred to as a memory) may be configured to store information within computing device 14, including at least one application 180 and data 190. Storage device 172, in some examples, is a computer-readable storage medium. In some examples, storage device 172 includes a temporary memory or a volatile memory. Storage device 172, in one example, is used by at least one application 180 running on computing device 14 to temporarily store information during program execution. Storage device 172, in some examples, also includes one or more memories configured for long-term storage of information, e.g., including non-volatile storage elements. Examples of such nonvolatile storage elements include any volatile, non-volatile, magnetic, optical, or electrical media, such as a random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically-erasable programmable ROM (EEPROM), flash memory, or any other digital media.

[0076] Computing device 14 utilizes communication circuitry 174 to communicate with other devices, such as catheter 12, controller 16, other computing devices, and system 10 of FIG. 1. Communication circuitry 174 may include a network interface card, such as an Ethernet card, an optical transceiver, a radio frequency transceiver, or any other type of devicethat can send and receive information. Other examples of such network interfaces may include 3G, 4G, 5G, and WiFi radios.

[0077] Computing device 14 may include a user interface 176. User interface 176 may be configured to provide output to a user using tactile, audio, or video stimuli and receive input from a user through tactile, audio, or video feedback. User interface 176 may include, as examples, a presence-sensitive display, a mouse, a keyboard, a voice responsive system, video camera, microphone, or any other type of device for detecting a command from a user, a sound card, a video graphics adapter card, or any other type of device for converting a signal into an appropriate form understandable to humans or machines, a speaker, a display device, such as, but not limited to, cathode ray tube (CRT) monitor, a liquid crystal display (LCD), or any other type of device that can generate intelligible output to a user. In some examples, a presence-sensitive display includes a touch-sensitive screen.

[0078] At least one application 180 executable by processing circuitry 170 of computing device 14 may include a stimulation interface application 182 and a monitoring system 184 that may utilize physiological data or other data obtained during neuromodulation to monitor the progress of neuromodulation and effects of ablation. At least one application 180 further may include an ablation interface application 186 that controls delivery of ablation via controller 16 and / or catheter 12 or catheter 112.

[0079] Execution of stimulation interface 182 and ablation interface 186 by processing circuitry 170 configures computing device 14 to interface with system 10 or controller 16 (or catheter 12 or catheter 112). For example, stimulation interface 82 configures computing device 14 to communicate with controller 16 via communication circuitry 184. Processing circuitry 170 may receive a signal from a physiological sensor indicative of a physiological parameter, and store the physiological data 192 in storage device 172. Stimulation interface 182 and / or ablation interface 186 also configures user interface 176 for a user to interact with controller 16 (or catheter 12 or catheter 112). One or more of stimulation interface 182, monitoring system 184, or ablation interface 186 may cause processing circuity 170 and computing device 14 to perform any of the techniques described herein related to neuromodulation by system 10.

[0080] FIG. 7 is a flow diagram illustrating an example technique for neuromodulation. The example technique of FIG. 7 is described with reference to processing circuitry 170 of computing device 14 and system 10 of FIGS. 1 A to 1C. However, the example techniquemay be implemented by any suitable computing device, controller, or system alone or in combination with processing circuitry 170.

[0081] The technique may include sending, by processing circuitry 170, an electrical signal to neuromodulation catheter 12 or 112 (200). For example, processing circuitry 170 may cause controller 16 to generate the electrical signal including an ablation signal and a stimulation signal, and to send the electrical signal to neuromodulation catheter 12 or 112. The technique may further include filtering, by filter circuitry 32, the electrical signal into the ablation signal and the stimulation signal (202). The technique may further include delivering, by the plurality of ablation electrodes 26, a first ablation signal based on the AC component to a target site (204). The technique may further include delivering, by the plurality of stimulation electrodes 28, a first electrical stimulation signal based on the DC component to the target site (206). In some examples, the first electrical stimulation signal is delivered after the first ablation signal.

[0082] In some examples, the technique further includes delivering, by the plurality of ablation electrodes 26, after the first electrical stimulation signal, a second ablation signal to the target site (208). In some examples, the technique further includes measuring, by processing circuitry 170, impedance after the second ablation signal (210).

[0083] In some examples, the technique further includes delivering, by the plurality of stimulation electrodes 28, a second electrical stimulation signal after measuring impedance (212). The technique may further include comparing, by processing circuitry 170, a physiological parameter after the first electrical stimulation signal and the electrical second stimulation signal. Processing circuitry 170 may initiate, continue, or terminate ablation in response to the comparison. For example, processing circuitry 170 may cause controller 16 to initiate, continue, or terminate ablation in response to the comparison. For example, if the comparison indicates that neural traffic is attenuated, or that the target site has been sufficiently ablated or denervated, processing circuitry 170 may cause controller 16 to terminate ablation. However, if the comparison indicates that neural traffic is not attenuated, or that the target site has not been sufficiently ablated or denervated, processing circuitry 170 may cause controller 16 to initiate or continue ablation.

[0084] Thus, example systems and techniques according to the present disclosure may be used to deliver, monitor, or control neuromodulation therapy.

[0085] FIG. 8 illustrates an example technique for accessing a renal artery and modulating renal nerves with a neuromodulation catheter. While FIG. 8 illustrates the use of catheter 12for renal neuromodulation, catheter 12 may be used for other therapies and treatments within another blood vessel or other hollow anatomical body within the human body. Catheter 12 is configured to delivery energy (e.g., RF energy, ultrasound energy, electrical stimulation energy, or the like) to one or more target tissue sites within a renal vessel. Catheter 12 provides access to the renal plexus (RP) through an intravascular path (P), such as a percutaneous access site in the femoral (illustrated), brachial, radial, or axillary artery to the target tissue sites within a respective renal artery (RA). By manipulating proximal portion 22B or elongate body 22 from outside the intravascular path (P), a clinician may advance distal portion 22A of elongate body 22 through the sometimes-tortuous intravascular path (P) and remotely manipulate distal portion 22A (FIG. 1 A) of elongate body 22. Distal portion 22A may be remotely manipulated by the clinician using handle 20.

[0086] In the example illustrated in FIG. 8, distal portion 22A is delivered intravascularly to the treatment site using an inner member 123 in an over-the-wire (OTW) technique. Inner member 123 may be internal to catheter 12 (e.g., a guide wire, inner catheter, or the like) or external to catheter 12 (e.g., an outer sheath or the like). In some examples, inner member 123 is a navigation wire. Catheter 12 may define a passageway for receiving inner member 23 for delivery of catheter 12 using either an OTW or an RX technique. At the treatment site, inner member 123 can be at least partially withdrawn or removed relative to catheter 12 and distal portion 22A can transform into an expanded configuration (for example, a helical configuration, a spiral configuration, or the like) for delivering ultrasound energy. In other examples, elongate body 22 may be self-steerable such that therapy may be delivered to the target tissue site without the aid of inner member 123.

[0087] Renal modulation is the partial or complete incapacitation or other effective disruption of nerves of the kidneys (e.g., nerves terminating in the kidneys or in structures closely associated with the kidneys). In particular, renal neuromodulation can include inhibiting, reducing, or blocking neural communication along neural fibers (e.g., efferent or afferent neural fibers) of the kidneys. Such incapacitation can be long-term (e.g., permanent or for a period of months, years, or decades) or short-term (e.g., for periods of minutes, hours, days, or weeks). Renal neuromodulation is expected to contribute to the systemic reduction of sympathetic tone or drive or benefit at least some specific organs or other bodily structures innervated by sympathetic nerves. Accordingly, renal neuromodulation is expected to be useful in treating clinical conditions associated with central sympathetic overstimulation. For example, renal neuromodulation is expected to efficaciously treat hypertension, heart failure,acute myocardial infarction, metabolic syndrome, insulin resistance, diabetes, left ventricular hypertrophy, chronic and end state renal disease, inappropriate fluid retention in heart failure, cardio-renal syndrome, polycystic kidney disease, polycystic ovary syndrome, osteoporosis, erectile dysfunction, and sudden death, among other conditions.

[0088] Renal neuromodulation can be electrically induced or induced in another suitable manner through the delivery of energy (RF energy, ultrasound energy, microwave energy, or the like). The target tissue site can be within or otherwise proximate to a renal lumen (e.g., a renal artery, a ureter, a renal pelvis, a major renal calyx, a minor renal calyx, or another suitable structure), and the target tissue site can include tissue at least proximate to a wall of the renal lumen. For example, with regard to a renal artery, a treatment procedure can include modulating nerves in the renal plexus, which lay intimately within or adjacent to the adventitia of the renal artery. The following discussion provides further details regarding patient anatomy and physiology as it may relate to renal denervation therapy. This section is intended to supplement and expand upon the previous discussion regarding the relevant anatomy and physiology, and to provide additional context regarding the disclosed technology and the therapeutic benefits associated with renal denervation. For example, several properties of the renal vasculature may inform the design of the target tissue devices and associated methods for achieving renal neuromodulation via intravascular access and impose specific design requirements for such devices. Specific design requirements may include accessing the renal artery, positioning distal portion 22A within the renal artery, delivering the therapy to targeted tissue, or effectively modulating the renal nerves with the therapy delivery device.

[0089] As noted previously, the sympathetic nervous system (SNS) is a branch of the autonomic nervous system along with the enteric nervous system and parasympathetic nervous system. It is always active at a basal level (called sympathetic tone) and becomes more active during times of stress. Like other parts of the nervous system, the sympathetic nervous system operated through a series of interconnected neurons. Sympathetic neurons are frequently considered part of the peripheral nervous system (PNS), although many lie within the central nervous system (CNS). Sympathetic neurons of the spinal cord (which is part of the CNS) communicate with peripheral sympathetic neurons via a series of sympathetic ganglia. Within the ganglia, spinal cord sympathetic neurons are therefore called presynaptic (or preganglionic) neurons, while peripheral sympathetic neurons are called postsynaptic (or postganglionic neurons).

[0090] At synapses within the sympathetic ganglia, preganglionic sympathetic neurons release acetylcholine, a chemical messenger that binds and activates nicotinic acetylcholine receptors on postganglionic neurons. In response to this stimulus, postganglionic neurons principally release noradrenaline (norepinephrine). Prolonged activation may elicit the release of adrenaline from the adrenal medulla.

[0091] Once released, norepinephrine and epinephrine bind adrenergic receptors on peripheral tissues. Binding to adrenergic receptors causes a neuronal and hormonal response. The physiologic manifestations include pupil dilation, increased heart rate, occasional vomiting, and increased blood pressure. Increased sweating is also seen due to binding of cholinergic receptors of the sweat glands.

[0092] The sympathetic nervous system is responsible for up- and down-regulating many homeostatic mechanisms in living organisms. Fibers from the SNS innervate tissues in almost every organ system, providing at least some regulatory function to physiological features as diverse as pupil diameter, gut motility, and urinary output. This response is also known as sympatho-adrenal response of the body, as the preganglionic sympathetic fibers that end in the adrenal medulla (but also all other sympathetic fibers) secrete acetylcholine, which activates the secretion of adrenaline (epinephrine) and to a lesser extent noradrenaline (norepinephrine). Therefore, this response that acts primarily on the cardiovascular system is mediated directly via impulses transmitted through the sympathetic nervous system and indirectly via catecholamines secreted from the adrenal medulla.

[0093] FIG. 9 is a conceptual illustration of an example sympathetic nervous system (SNS) illustrating how the brain communicated with the body via the SNS. As shown in FIG.9, the SNS provides a network of nerves that allows the brain to communicate with the body. Sympathetic nerves originate inside the vertebral column, e.g., toward the middle of the spinal cord in the intermediolateral cell column (or lateral horn), beginning at the first thoracic segment of the spinal cord and are thought to extend to the second or third lumbar segments. Because SNS cells begin in the thoracic and lumbar regions of the spinal cord, the SNS is said to have a thoracolumbar outflow. Axons of sympathetic nerves leave the spinal cord through the anterior rootlet / root. The axons pass near the spinal (sensory) ganglion, where the axons enter the anterior rami of the spinal nerves. However, unlike somatic innervation, the axons separate out through white rami connectors which connect to either the paravertebral (which lie near the vertebral column) or prevertebral (which lie near the aortic bifurcation) ganglia extending alongside the spinal column.

[0094] To reach the target organs and glands, the axons should travel long distances in the body, and, to accomplish this, many axons relay their message to a second cell through synaptic transmission. The ends of the axons link across a space, the synapse, to the dendrites of the second cell. The first cell (the presynaptic cell) sends a neurotransmitter across the synaptic cleft where it activates the second cell (the postsynaptic cell). The message is then carried to the final destination.

[0095] In the SNS and other component of the peripheral nervous system, these synapses are made at sites called ganglia, discussed above. The cell that sends its fiber to the ganglion is called a preganglionic cell, while the cell whose fiber leaves the ganglion is called a postganglionic cell. As mentioned previously, the preganglionic cell of the SNS is located between the first thoracic (Tl) segment and third lumbar (L3) segments of the spinal cord. Postganglionic cells have their cell bodies in the ganglia and send their axons to target organs or glands.

[0096] The ganglia include not just the sympathetic trunks but also the cervical ganglia(superior, middle, and inferior), which send sympathetic nerve fibers to the head and thorax organs, and the celiac and mesenteric ganglia, which send sympathetic fibers to the gut.

[0097] FIG. 10 is an enlarged anatomic view of nerves innervating a left kidney to form the renal plexus surrounding the left renal artery. As FIG. 10 shows, the kidney is innervated by the renal plexus (RP), which is intimately associated with the renal artery. The renal plexus (RP) is an autonomic plexus that surrounds the renal artery and is embedded within the adventitia of the renal artery. The renal plexus (RP) extends along the renal artery and is embedded within the adventitia of the renal artery. Fibers contributing to the renal plexus (RP) arise from the celiac ganglion, the superior mesenteric ganglion, the aorticorenal ganglion and the aortic plexus. The renal plexus (RP), also referred to as the renal nerve, is predominantly comprised of sympathetic components. There is no (or at least very minimal) parasympathetic innervation of the kidney.

[0098] Preganglionic neuronal cell bodies are located in the intermediolateral cell column of the spinal cord. Preganglionic axons pass through the paravertebral ganglia to become the lesser splanchnic nerve, the least splanchnic nerve, the first lumbar splanchnic nerve, the second lumbar splanchnic nerve, and travel to the celiac ganglion, the superior mesenteric ganglion, and the aorticorenal ganglion. Postganglionic neuronal cell bodies exit the celiac ganglion, the superior mesenteric ganglion, and the aorticorenal ganglion to the renal plexus (RP) and are distributed to the renal vasculature.

[0099] Messages travel through the SNS in a bi-directional flow. Efferent messages may trigger changes in different parts of the body simultaneously. For example, the sympathetic nervous system may accelerate heart rate, widen bronchial passages, decrease motility (movement) of the large intestine, constrict blood vessels, increase peristalsis in the esophagus, cause pupil dilation, piloerection (goose bumps) and perspiration (sweating), or raise blood pressure. Afferent messages carry signals from various organs and sensory receptors in the body to other organs and, particularly, the brain.

[0100] Hypertension, heart failure, and chronic kidney disease are a few of the many disease states that result from chronic activation of the SNS, especially the renal sympathetic nervous system. Chronic activation of the SNS is a maladaptive response that drives the progression of theses disease states. Pharmaceutical management of the renin-angiotensin- aldosterone system (RAAS) has been a longstanding, but somewhat ineffective, approach for reducing over-activity of the SNS.

[0101] As mentioned above, the renal sympathetic nervous system has been identified as a major contributor to the complex pathophysiology of hypertension, states of volume overload (such as heart failure) and progressive renal disease, both experimentally and in humans. Studies employing radiotracer dilution methodology to measure overflow of norepinephrine from the kidneys to plasma revealed increased renal norepinephrine (NE) spillover rates in patients with essential hypertension, particularly so in young hypertensive subjects, which in concert with increased NE spillover from the heart, is consistent with the hemodynamic profile typically seen in early hypertension and characterized by an increased heart rate, cardiac output, and renovascular resistance. It is now known that essential hypertension is commonly neurogenic, often accompanied by pronounced sympathetic nervous system overactivity.

[0102] Activation of cardiorenal sympathetic nerve activity is even more pronounced in heart failure, as demonstrated by an exaggerated increase of NE overflow from the heart and the kidneys to plasma in this patient group. In line with this notion is the recent demonstration of a strong negative predictive value of renal sympathetic activation on allcause mortality and heart transplantation in patients with congestive heart failure, which is independent of overall sympathetic activity, glomerular filtration late, and left ventricular ejection fraction. These findings support the notion that treatment regimens that are designed to reduce renal sympathetic stimulation have the potential to improve survival in patients with heart failure.

[0103] Both chronic and end state renal disease in some patients are characterized by heightened sympathetic nervous activation. In patients with end state renal disease, plasma levels of norepinephrine above the media have been demonstrated to be predictive for both all-cause death and death from cardiovascular disease. This can also be true for patients suffering from diabetic or contrast nephropathy. There is compelling evidence suggesting that sensory afferent signals originating from the diseased kidneys are major contributors to initiating and sustaining elevated central sympathetic outflow in this patient group; this facilitates the occurrence of the well-known adverse consequences of chronic sympathetic over activity, such as hypertension, left ventricular hypertrophy, ventricular arrhythmias, sudden cardiac death, insulin resistance, diabetes, and metabolic syndrome.

[0104] Sympathetic nerves to the kidneys terminate in the blood vessels, the juxtaglomerular apparatus, and the renal tubules. Stimulation of the renal sympathetic nerves cause increased renin release, increased sodium (Na+) reabsorption, and a reduction of renal blood flow. These components of the neural regulation of renal function are considerably stimulated in disease states characterized by heightened sympathetic tone and clearly contribute to the rise in blood pressure in hypertensive patients. The reduction of renal blood flow and glomerular filtration rate as a result of renal sympathetic efferent stimulation may be a cornerstone of the loss of renal function in cardio-renal syndrome, which is renal dysfunction as a progressive complication of chronic heart failure, with a clinical course that typically fluctuates with the patient’s clinical status and treatment. Pharmacologic strategies to thwart the consequences of renal efferent sympathetic stimulation include centrally acting sympatholytic drugs, beta blockers (intended to reduce renin release), angiotensin converting enzyme inhibitors and receptor blockers (intended to block the action of angiotensin II and aldosterone activation consequent to renin release), and diuretics (intended to counter the renal sympathetic mediated sodium and water retention). However, the current pharmacologic strategies can have significant limitations including limited efficacy, compliance issues, side effects, and others.

[0105] The kidneys communicate with integral structures in the central nervous system via renal sensory afferent nerves. Several forms of “renal injury” may induce activation of sensory afferent signals. For example, renal ischemia, reduction in stroke volume or renal blood flow, or an abundance of adenosine enzyme may trigger activation of afferent neural communication.

[0106] FIG. 11 is an anatomic view of a human body depicting neural efferent and afferent communication between the brain and kidneys. FIG. 12 is a conceptual view of a human body depicting neural efferent and afferent communication between the brain and kidneys. As shown in FIGS. 11 and 12, the afferent communication might be from kidney to the brain or might be from one kidney to the other kidney (via the central nervous system). These afferent signals are centrally integrated and may result in increased sympathetic outflow. This sympathetic drive is directed towards the kidneys, thereby activating the RAAS and inducing increased renin secretion, sodium retention, volume retention, and vasoconstriction. Central sympathetic over activity also impacts other organs and bodily structures innervated by sympathetic nerves such as the heart and the peripheral vasculature, resulting in the described adverse effects of sympathetic activation, several aspects of which also contribute to the rise in blood pressure.

[0107] The physiology therefore suggests that (i) modulation of tissue with efferent sympathetic nerves will reduce inappropriate renin release, salt retention, and reduction of renal blood flow, and that (ii) modulation of tissue with afferent sensory nerves will reduce the systemic contribution to hypertension and other disease states associated with increased central sympathetic tone through its direct effect on the posterior hypothalamus as well as the contralateral kidney. In addition to the central hypotensive effects of afferent renal denervation, a desirable reduction of central sympathetic outflow to various other sympathetically innervated organs such as the heart and the vasculature is anticipated.

[0108] As provided above, renal denervation is likely to be valuable in the treatment of several clinical conditions characterized by increased overall and particularly renal sympathetic activity such as hypertension, metabolic syndrome, insulin resistance, diabetes, left ventricular hypertrophy, chronic end state renal disease, inappropriate fluid retention in heart failure, cardio-renal syndrome and sudden death. Since the reduction of afferent neural signals contributing to the systemic reduction of sympathetic tone / drive, renal denervation might also be useful in treating other conditions associate with systemic sympathetic hyperactivity. Accordingly, renal denervation may also benefit other organs and bodily structures innervated by sympathetic nerves, including those identified in FIG. 12. For example, as previously discussed, a reduction in central sympathetic drive may reduce the insulin resistance that afflicts people with metabolic syndrome and Type II diabetics. Additionally, patients with osteoporosis may also be sympathetically activated and might also benefit from the down regulation of sympathetic drive that accompanies renal denervation.

[0109] In accordance with the present technology neuromodulation of a left or right renal plexus (RP), which is intimately associated with a left or right renal artery, may be achieved through intravascular access. FIG. 13 is an anatomic view of the arterial vasculature of a human. As FIG. 13 shows, blood moved by contractions of the heart is conveyed from the left ventricle of the heart by the aorta. The aorta descends through the thorax and branches into the left and right renal arteries. Below the renal arteries, the aorta bifurcates at the left and right iliac arteries. The left and right iliac arteries descend, respectively, through the left and right legs and join the left and right femoral arteries.

[0110] FIG. 14 is an anatomic view of the venous vasculature of a human. As FIG. 14 shows, the blood collects in veins and returns to the heart, through the femoral veins into the iliac veins and into the inferior vena cava. The inferior vena cava branches into the left and right renal veins. Above the renal veins, the inferior vena cava ascends to convey blood into the right atrium of the heart. From the right atrium, the blood is pumped through the right ventricle into the lungs, where it is oxygenated. From the lungs, the oxygenated blood is conveyed into the left atrium. From the left atrium, the oxygenated blood is conveyed by the left ventricle back to the aorta.[OHl] The femoral artery may be accessed and cannulated at the base on the femoral triangle just inferior to the midpoint of the inguinal ligament. A catheter may be inserted percutaneously into the femoral artery through this access site, passed through the iliac artery and aorta, and placed into either the left or right renal artery. This comprises an intravascular path that offers minimally invasive access to a respective renal artery or other renal blood vessels.

[0112] The wrist, upper arm, and shoulder region provide other locations for introduction of catheters into the arterial system. For example, catheterization of either the radial, brachial, or axillary artery may be utilized in select cases. Catheters (e.g., catheter 12) introduced via these access points may be passed through the subclavian artery on the left side (or via the subclavian and brachiocephalic arteries on the right side), through the aortic arch, down the descending aorta and into the renal arteries using standard angiographic techniques. Other access sites can also be used to access the arterial system.

[0113] Since neuromodulation of a left or right renal plexus (RP) may be achieved in accordance with the present technology through intravascular access, properties and characteristics of the renal vasculature may impose constraints upon or inform the design of apparatus, systems, and methods for achieving such renal neuromodulation. Some of theseproperties and characteristics may vary across the patient population or within a specific patient across time, as well as in response to disease states, such as hypertension, chronic kidney disease, vascular disease, end-stage renal disease, insulin resistance, diabetes, metabolic syndrome, and the like. These properties and characteristics, as explained herein, may have bearing on the efficacy of the procedure and the specific design of the intravascular device. Properties of interest may include, for example, material / mechanical, spatial, fluid dynamic / hemodynamic or thermodynamic properties.

[0114] As discussed previously, a catheter may be advanced percutaneously into either the left or right renal artery via a minimally invasive intravascular path. However, minimally invasive renal arterial access may be challenging, for example, because as compared to some other arteries that are routinely accessed using catheters, the renal arteries are often extremely tortuous, may be of relatively small diameter, or may be of relatively short length.Furthermore, renal arterial atherosclerosis is common in many patients, particularly those with cardiovascular disease. Renal arterial anatomy also may vary significantly from patient to patient, which further complicates minimally invasive access. Significant inter-patient variation may be seen, for example, in relative tortuosity, diameter, length, or atherosclerotic plaque burden, as well as in the take-off angle at which a renal artery branches from the aorta. Further, some patients include multiple left renal arteries or right renal arteries. Apparatus, systems, and methods for achieving renal neuromodulation via intravascular access should account for these and other aspects of renal arterial anatomy and its variation across the patient population when minimally invasively accessing a renal artery.

[0115] In addition to complicating renal arterial access, specifics of the renal anatomy also complicate establishment of stable contact between neuromodulatory apparatus and a luminal surface or wall of a renal artery. For example, navigation can be impeded by the tight space within a renal artery, as well as tortuosity of the artery. Furthermore, establishing consistent contact is complicated by patient movement, respiration, or the cardiac cycle because these factors may cause significant movement of the renal artery relative to the aorta, and the cardiac cycle may transiently distend the renal artery (i.e., cause the wall of the artery to pulse).

[0116] The neuromodulation system may also be configured to allow for adjustable positioning and repositioning of distal portion 22A (FIG. 1 A) within the renal artery since location of treatment may also impact clinical efficacy. Additionally, variable positioning and repositioning of the neuromodulatory apparatus may prove to be useful in circumstanceswhere the renal artery is particularly tortuous or where there are proximal branch vessels off the renal artery main vessel, making treatment in certain locations challenging.

[0117] As noted above, an apparatus positioned within a renal artery may be configured so that distal portion 22A of catheter 12 may intimately contact the vessel wall or extend at least partially through the vessel wall. Renal artery vessel diameter, DRA, typically is in a range of about 2-10 mm, with most of the patient population having a DRA of about 4 mm to about 8 mm and an average of about 6 mm. Renal artery vessel length, LRA, between its ostium at the aorta / renal artery juncture and its distal branchings, generally is in a range of about 5-70 mm, and a significant portion of the patient population is in a range of about 20-50 mm. Since the target renal plexus is embedded within the adventitia of the renal artery, the composite Intima-Media Thickness, IMT, (i.e., the radial outward distance from the artery's luminal surface to the adventitia containing target neural structures) also is notable and generally is in a range of about 0.5-2.5 mm, with an average of about 1.5 mm. Although a certain depth of treatment is important to reach the target neural fibers, the treatment should not be too deep (e.g., > 10 mm from inner wall of the artery) to avoid non-target tissue and anatomical structures such as anatomical structures of the digestive system of psoas muscle.

[0118] An additional property of the renal artery that may be of interest is the degree of renal motion relative to the aorta induced by respiration or blood flow pulsatility. A patient’s kidney, which is located at the distal end of the renal artery, may move as much as 10 centimeters cranially with respiratory excursion. This may impart significant motion to the renal artery connecting the aorta and the kidney, thereby requiring from the neuromodulatory apparatus a unique balance of stiffness and flexibility to maintain contact between the energy delivery element and the vessel wall during cycles of respiration. Furthermore, the take-off angle between the renal artery and aorta may vary significantly between patients, and also may vary dynamically within a patient, e.g., due to kidney motion. The take-off angle generally may be in a range of about 30°-135°.

[0119] Certain aspects of the present disclosure described in the context of particular examples may be combined or eliminated in other examples. Further, while advantages associated with certain examples have been described in the context of those examples, other examples may also exhibit such advantages, and not all examples need necessarily exhibit such advantages to fall within the scope of the present disclosure. Accordingly, the present disclosure and associated technology can encompass other examples not expressly shown or described herein.

[0120] Moreover, unless the word “or” is expressly limited to mean only a single term exclusive from the other items in reference to a list of two or more items, then the use of “or” in such a list is to be interpreted as including (a) any single item in list, (b) all of the items in the list, or (c) any combination of the items in the list. Additionally, the term “comprising” is used throughout to mean including at least the recited feature(s) such that any greater number of the same feature and / or additional types of other features are not precluded.

[0121] It should be understood that various aspects disclosed herein may be combined in different combinations than the combinations specifically presented in the description and accompanying drawings. It should also be understood that, depending on the example, certain acts or events of any of the processes or methods described herein may be performed in a different sequence, may be added, merged, or left out altogether (e.g., all described acts or events may not be necessary to carry out the techniques). In addition, while certain aspects of this disclosure are described as being performed by a single module, unit, or circuit for purposes of clarity, it should be understood that the techniques of this disclosure may be performed by a combination of units, modules, or circuitry associated with, for example, a medical device.

[0122] In one or more examples, the described techniques may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored as one or more instructions or code on a computer-readable medium and executed by a hardware-based processing unit. Computer-readable media may include non-transitory computer-readable media, which corresponds to a tangible medium such as data storage media (e.g., RAM, ROM, EEPROM, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer).

[0123] Instructions may be executed by one or more processors that include processing circuitry, such as one or more digital signal processors (DSPs), general purpose microprocessors, application specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuitry. Accordingly, the term “processor” or “processing circuitry” as used herein may refer to any of the foregoing structure or any other physical structure suitable for implementation of the described techniques. Also, the techniques could be fully implemented in one or more circuits or logic elements.

[0124] The above detailed descriptions of examples of the technology are not intended to be exhaustive or to limit the technology to the precise form disclosed above. Although specific examples of the technology are described above for illustrative purposes, various equivalent modifications are possible within the scope of the technology, as those skilled in the relevant art will recognize. For example, while steps are presented in a given order, alternative examples may perform steps in a different order. The various examples described herein may also be combined to provide further examples. All references cited herein are incorporated by reference as if fully set forth herein.

[0125] Clause 1 : A neuromodulation catheter including: an elongate body; a plurality of ablation electrodes along the elongate body; a plurality of stimulation electrodes along the elongate body; and filter circuitry electrically coupled to the plurality of ablation electrodes and the plurality of stimulation electrodes, where the filter circuitry is configured to: receive an electrical signal including a stimulation signal and an ablation signal, the stimulation signal including a first frequency or frequency range and the ablation signal having a second frequency that is greater than the first frequency or frequency range; filter the stimulation signal from the electrical signal and deliver the stimulation signal to the plurality of stimulation electrodes, and filter the ablation signal from the electrical signal and deliver the ablation signal to the plurality of ablation electrodes.

[0126] Clause 2: The neuromodulation catheter of clause 1, where the first frequency is zero, and the stimulation signal is a direct current (DC) component of the electrical signal.

[0127] Clause 3 : The neuromodulation catheter of any of clauses 1 and 2, where the second frequency is non-zero, and the ablation signal is an alternating current (AC) component of the electrical signal.

[0128] Clause 4: The neuromodulation catheter of any of clauses 1 to 3, where the filter circuitry includes at least one capacitor or at least one inductor.

[0129] Clause 5: The neuromodulation catheter of clause 4, where the filter circuitry includes at least one resistor-capacitor (RC) circuit.

[0130] Clause 6: The neuromodulation catheter of any of clauses 1 to 5, where the plurality of ablation electrodes is interleaved with the plurality of stimulation electrodes along the elongate body.

[0131] Clause 7: The neuromodulation catheter of clause 6, where each ablation electrode of the plurality of ablation electrodes is distal to a respective stimulation electrode of the plurality of stimulation electrodes.

[0132] Clause 8: The neuromodulation catheter of clause 6, where each ablation electrode of the plurality of ablation electrodes is proximal to a respective stimulation electrode of the plurality of stimulation electrodes.

[0133] Clause 9: The neuromodulation catheter of any of clauses 1 to 8, where each ablation electrode of the plurality of ablation electrodes has a same ablation electrode length along a longitudinal axis of the elongate body, and where each stimulation electrode of the plurality of stimulation electrodes has a same stimulation electrode length along the longitudinal axis of the elongate body.

[0134] Clause 10: The neuromodulation catheter of clause 9, where the stimulation electrode length is less than the ablation electrode length.

[0135] Clause 11 : The neuromodulation catheter of any of clauses 1 to 10, where the filter circuitry is proximal to the plurality of ablation electrodes and to the plurality of stimulation electrodes relative to the elongate body.

[0136] Clause 12: The neuromodulation catheter of any of clauses 1 to 11, where the elongate body includes a proximal elongate body portion and a distal elongate body portion, and where the plurality of ablation electrodes and the plurality of stimulation electrodes are each positioned along the distal elongate body portion.

[0137] Clause 13: The neuromodulation catheter of clause 12, where the filter circuitry is positioned along the distal elongate body portion.

[0138] Clause 14: The neuromodulation catheter of clause 12, where the filter circuitry is positioned along the proximal elongate body portion.

[0139] Clause 15: The neuromodulation catheter of any of clauses 1 to 14, where the filter circuitry is formed on a flexible board.

[0140] Clause 16: The neuromodulation catheter of clause 15, where the flexible board is wrapped about the elongate body, wrapped about a jacket, or embedded about a lumen defined by the elongate body.

[0141] Clause 17: The neuromodulation catheter of any of clauses 1 to 16, where the filter circuitry includes a filter block along the elongate body.

[0142] Clause 18: The neuromodulation catheter of any of clauses 1 to 16, where the filter circuitry includes a plurality of filter blocks along the elongate body.

[0143] Clause 19: The neuromodulation catheter of clause 18, where the plurality of filter blocks is interleaved with the plurality of ablation electrodes and the plurality of stimulation electrodes.

[0144] Clause 20: The neuromodulation catheter of clauses 18 or 19, where each filter block of the plurality of filter blocks is positioned adjacent a respective ablation electrode of the plurality of ablation electrodes or a respective stimulation electrode of the plurality of stimulation electrodes.

[0145] Clause 21 : The neuromodulation catheter of any of clauses 18 to 20, where each filter block of the plurality of filter blocks is proximal to a respective ablation electrode of the plurality of ablation electrodes and to a respective stimulation electrode of the plurality of stimulation electrodes.

[0146] Clause 22: The neuromodulation catheter of any of clauses 18 to 21, where each filter block of the plurality of filter blocks is electrically coupled to a single signal cable extending along the elongate body to receive the electrical signal from a controller.

[0147] Clause 23 : The neuromodulation catheter of any of clauses 1 to 22, where the first frequency is in a range of from 0 Hz to 200 Hz.

[0148] Clause 24: The neuromodulation catheter of any of clauses 1 to 23, where the second frequency is in a range of from 100 kHz to 1 MHz.

[0149] Clause 25: The neuromodulation catheter of any of clauses 1 to 24, each ablation electrode of the plurality of ablation electrodes is coupled to a respective thermocouple.

[0150] Clause 26: A neuromodulation system including: the neuromodulation catheter of any of clauses 1 to 25; and a controller configured to generate the electrical signal including the ablation signal to be delivered by the plurality of ablation electrodes and the stimulation signal to be delivered by the plurality of stimulation electrodes.

[0151] Clause 27: The neuromodulation system of clause 26, where the controller includes a generator configured to generate the ablation signal and a stimulator configured to generate the stimulation signal.

[0152] Clause 28: The neuromodulation system of clauses 26 or 27, further including a computing device configured to control the controller to deliver neuromodulation therapy via the neuromodulation catheter.

[0153] Clause 29: A method for neuromodulation, the method including: sending, by processing circuitry, the electrical signal to the neuromodulation catheter of any of clauses 1 to 28; filtering, by the filter circuitry, the electrical signal into the ablation signal and the stimulation signal; delivering, by the plurality of ablation electrodes, the ablation signal to a target site; and delivering, by the plurality of stimulation electrodes, the stimulation signal to the target site.

[0154] Clause 30: The method of clause 29, where the stimulation signal is delivered to the target site after the ablation signal.

[0155] Clause 31 : The method of clause 30, where the ablation signal is a first ablation signal, the method further including, delivering, by the plurality of ablation electrodes, after the stimulation signal, a second ablation signal to the target site.

[0156] Clause 32: The method of clause 31, further including measuring, by the processing circuitry, impedance after the second ablation signal.

[0157] Clause 33: The method of clause 32, where the stimulation signal is a first stimulation signal, further including delivering, by the plurality of stimulation electrodes, a second electrical stimulation signal after measuring the impedance.

[0158] Clause 34: The method of clause 33, further including: comparing, by the processing circuitry, a physiological parameter after the first stimulation signal and the second stimulation signal; and continuing or terminating, by the processing circuitry, ablation in response to the comparison.

[0159] From the foregoing, it will be appreciated that specific examples of the present disclosure have been described herein for purposes of illustration, but that various modifications may be made without deviating from the present disclosure.

[0160] Various examples have been described. These and other examples are within the scope of the following claims. Further disclosed herein is the subject-matter of the following clauses:1. A neuromodulation catheter comprising: an elongate body; a plurality of ablation electrodes along the elongate body; a plurality of stimulation electrodes along the elongate body; and filter circuitry electrically coupled to the plurality of ablation electrodes and the plurality of stimulation electrodes, wherein the filter circuitry is configured to: receive an electrical signal comprising a stimulation signal and an ablation signal, the stimulation signal including a first frequency or frequency range and the ablation signal having a second frequency that is greater than the first frequency or frequency range; filter the stimulation signal from the electrical signal and deliver the stimulation signal to the plurality of stimulation electrodes, andfilter the ablation signal from the electrical signal and deliver the ablation signal to the plurality of ablation electrodes.2. The neuromodulation catheter of clause 1, wherein the first frequency is zero, and the stimulation signal is a direct current (DC) component of the electrical signal.3. The neuromodulation catheter of any of clauses 1 and 2, wherein the second frequency is non-zero, and the ablation signal is an alternating current (AC) component of the electrical signal.4. The neuromodulation catheter of any of clauses 1 to 3, wherein the filter circuitry comprises at least one capacitor or at least one inductor.5. The neuromodulation catheter of any of clauses 1 to 4, wherein the plurality of ablation electrodes is interleaved with the plurality of stimulation electrodes along the elongate body.6. The neuromodulation catheter of any of clauses 1 to 5, wherein each ablation electrode of the plurality of ablation electrodes has a same ablation electrode length along a longitudinal axis of the elongate body, and wherein each stimulation electrode of the plurality of stimulation electrodes has a same stimulation electrode length along the longitudinal axis of the elongate body.7. The neuromodulation catheter of any of clauses 1 to 6, wherein the filter circuitry is proximal to the plurality of ablation electrodes and to the plurality of stimulation electrodes relative to the elongate body.8. The neuromodulation catheter of any of clauses 1 to 7, wherein the elongate body comprises a proximal elongate body portion and a distal elongate body portion, and wherein the plurality of ablation electrodes and the plurality of stimulation electrodes are each positioned along the distal elongate body portion.9. The neuromodulation catheter of any of clauses 1 to 8, wherein the filter circuitry is formed on a flexible board.10. The neuromodulation catheter of any of clauses 1 to 9, wherein the filter circuitry comprises a plurality of filter blocks along the elongate body.11. The neuromodulation catheter of clause 10, wherein the plurality of filter blocks is interleaved with the plurality of ablation electrodes and the plurality of stimulation electrodes.12. The neuromodulation catheter of clauses 10 or 11, wherein each filter block of the plurality of filter blocks is positioned adjacent a respective ablation electrode of the plurality of ablation electrodes or a respective stimulation electrode of the plurality of stimulation electrodes.13. The neuromodulation catheter of any of clauses 10 to 12, wherein each filter block of the plurality of filter blocks is electrically coupled to a single signal cable extending along the elongate body to receive the electrical signal from a controller.14. The neuromodulation catheter of any of clauses 1 to 13, wherein the first frequency is in a range of from 0 Hz to 200 Hz, and wherein the second frequency is in a range of from 100 kHz to 1 MHz.15. A neuromodulation system comprising: the neuromodulation catheter of any of clauses 1 to 14; and a controller configured to generate the electrical signal comprising the ablation signal to be delivered by the plurality of ablation electrodes and the stimulation signal to be delivered by the plurality of stimulation electrodes, wherein the controller comprises a generator configured to generate the ablation signal and a stimulator configured to generate the stimulation signal.

Claims

CLAIMS1. A neuromodulation catheter comprising: an elongate body; a plurality of ablation electrodes along the elongate body; a plurality of stimulation electrodes along the elongate body; and filter circuitry electrically coupled to the plurality of ablation electrodes and the plurality of stimulation electrodes, wherein the filter circuitry is configured to: receive an electrical signal comprising a stimulation signal and an ablation signal, the stimulation signal including a first frequency or frequency range and the ablation signal having a second frequency that is greater than the first frequency or frequency range; filter the stimulation signal from the electrical signal and deliver the stimulation signal to the plurality of stimulation electrodes, and filter the ablation signal from the electrical signal and deliver the ablation signal to the plurality of ablation electrodes.

2. The neuromodulation catheter of claim 1, wherein the first frequency is zero, and the stimulation signal is a direct current (DC) component of the electrical signal.

3. The neuromodulation catheter of any of claims 1 and 2, wherein the second frequency is non-zero, and the ablation signal is an alternating current (AC) component of the electrical signal.

4. The neuromodulation catheter of any of claims 1 to 3, wherein the filter circuitry comprises at least one capacitor or at least one inductor.

5. The neuromodulation catheter of any of claims 1 to 4, wherein the plurality of ablation electrodes is interleaved with the plurality of stimulation electrodes along the elongate body.

6. The neuromodulation catheter of any of claims 1 to 5, wherein each ablation electrode of the plurality of ablation electrodes has a same ablation electrode length along a longitudinalaxis of the elongate body, and wherein each stimulation electrode of the plurality of stimulation electrodes has a same stimulation electrode length along the longitudinal axis of the elongate body.

7. The neuromodulation catheter of any of claims 1 to 6, wherein the filter circuitry is proximal to the plurality of ablation electrodes and to the plurality of stimulation electrodes relative to the elongate body.

8. The neuromodulation catheter of any of claims 1 to 7, wherein the elongate body comprises a proximal elongate body portion and a distal elongate body portion, and wherein the plurality of ablation electrodes and the plurality of stimulation electrodes are each positioned along the distal elongate body portion.

9. The neuromodulation catheter of any of claims 1 to 8, wherein the filter circuitry is formed on a flexible board.

10. The neuromodulation catheter of any of claims 1 to 9, wherein the filter circuitry comprises a plurality of filter blocks along the elongate body.

11. The neuromodulation catheter of claim 10, wherein the plurality of filter blocks is interleaved with the plurality of ablation electrodes and the plurality of stimulation electrodes.

12. The neuromodulation catheter of claims 10 or 11, wherein each filter block of the plurality of filter blocks is positioned adjacent a respective ablation electrode of the plurality of ablation electrodes or a respective stimulation electrode of the plurality of stimulation electrodes.

13. The neuromodulation catheter of any of claims 10 to 12, wherein each filter block of the plurality of filter blocks is electrically coupled to a single signal cable extending along the elongate body to receive the electrical signal from a controller.

14. The neuromodulation catheter of any of claims 1 to 13, wherein the first frequency is in a range of from 0 Hz to 200 Hz, and wherein the second frequency is in a range of from 100 kHz to 1 MHz.

15. A neuromodulation system comprising: the neuromodulation catheter of any of claims 1 to 14; and a controller configured to generate the electrical signal comprising the ablation signal to be delivered by the plurality of ablation electrodes and the stimulation signal to be delivered by the plurality of stimulation electrodes, wherein the controller comprises a generator configured to generate the ablation signal and a stimulator configured to generate the stimulation signal.

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