WO2016132340A1

WO2016132340A1 - Flexible treatment catheter

Info

Publication number: WO2016132340A1
Application number: PCT/IB2016/050944
Authority: WO
Inventors: David Prutchi; Gary L. Boseck; Nathan Hampson WHITE; Alan Derek FORTUNATE; Joshua K. Goetz; Darrell Drysen
Original assignee: Renal Dynamics Ltd.
Priority date: 2015-02-22
Filing date: 2016-02-22
Publication date: 2016-08-25

Abstract

There is provided a treatment device for intraluminal insertion and treatment, comprising: rigid struts arranged approximately in parallel to each other, each end of each rigid strut connected to a leg comprising of at least one flexible element; at least one contact element adapted for contacting an inner wall of a body lumen, each of the rigid struts coupled to one or more of the contact elements; wherein the treatment device is adapted for radial expansion within the body lumen, wherein during the radial expansion the rigid struts are designed to be positioned along the circumference of the body lumen; wherein each flexible member is adapted to independently radially urge each corresponding rigid strut in at least one movement, to position at least one contact element associated with the rigid strut into contact with an inner wall of the body lumen during the expanded state.

Description

FLEXIBLE TREATMENT CATHETER

FIELD AND BACKGROUND OF THE PRESENT INVENTION

The present invention, in some embodiments thereof, relates to an intra-luminal treatment device and, more particularly, but not exclusively, to an intravascular treatment catheter performing a treatment by contact with an inner wall of a body lumen.

Target tissues located within body lumens, such as blood vessels, may be accessed for treatment in a minimally invasive manner, for example, by threading a catheter percutaneously, through the vascular system, to reach the target tissue.

Ablation using RF energy has been found to be particularly effective for performing certain treatment procedures, for example, for performing renal denervation.

International Patent Application Publication No. WO2014/118733 discloses "An ablation device and/or method of ablation may include placing one or more ablation electrodes in contact with a target tissue in a lumen. An electrical insulator may be positioned between the electrode and a lumen fluid and an electrical signal (for example a radio frequency signal) may be conveyed between the electrodes to heat and/or ablate the target tissue. Ablation may be bipolar and/or an in lumen disperse electrode may be supplied for unipolar ablation. Ablation progress may be sensed and ablation may be adjusted to produce a desired level and/or geometry of ablation."

International Patent Application Publication No. WO2014/118734 discloses "An ablation device and/or method of ablation may include placing one or more ablation electrodes in contact with a target tissue in a lumen. An electrical insulator may be positioned between the electrode and a lumen fluid and an electrical signal (for example a radio frequency signal) may be conveyed between the electrodes to heat and/or ablate the target tissue. Ablation may be bipolar and/or an in lumen dispersive electrode may be supplied for unipolar ablation. Ablation progress may be sensed and ablation may be adjusted to produce a desired level and/or geometry and/or distribution of ablation."

SUMMARY OF THE PRESENT INVENTION

An aspect of some embodiments of the present invention relates to an intraluminal treatment device having a plurality of sets of flexible element(s), each set independently positions a rigid strut associated with a set of contact element(s), to contact the contact elements with an inner wall of the lumen.

According to an aspect of some embodiments of the present invention there is provided a treatment device for intraluminal insertion and treatment, comprising: a plurality of rigid struts arranged approximately in parallel to each other, each end of each rigid strut connected to a leg comprising of at least one flexible element; at least one contact element adapted for contacting an inner wall of a body lumen, each of the plurality of rigid struts coupled to one or more of the at least one contact element; wherein the treatment device is adapted for radial expansion within the body lumen, from a first contracted state, to a second expanded state, wherein during the radial expansion the rigid struts are designed to be positioned along the circumference of the body lumen with a long axis of each strut positioned along the length of the lumen; wherein each flexible member is adapted to independently radially urge each corresponding rigid strut in at least one movement, to position at least one contact element associated with the rigid strut into contact with an inner wall of the body lumen during the second expanded state.

Optionally, the treatment device is expanded to the second expanded state to form an asymmetrical cross sectional shape according to the asymmetrical cross sectional shape of the inner wall of the body lumen, and each of the coupled flexible members independently positions each rigid strut and associated at least one contact element to contact the asymmetrical cross sectional shape of the inner wall.

Optionally, the treatment device is expanded to the second expanded state to form a non-uniform cross section along a length of the body lumen according to the nonuniform cross section of the length of the inner wall of the body lumen, and each of the coupled flexible members independently positions each rigid strut and associated at least one contact element to contact the non-uniform cross section along the length of the inner wall.

Optionally, the flexible members are made from an elastic material and are biased to yield when contacting the inner wall during expansion of the treatment device to avoid contact of a sharp corner formed by a flexible member- strut joint with the inner wall. Optionally, the at least one contact element is a radio frequency (RF) ablation electrode adapted for ablation of a target tissue when energy is applied to the RF electrode contacting the inner wall of the body lumen.

Optionally, the treatment device further comprises a plurality of electrical conductive wires, each of the at least one contact elements coupled to at least one of the plurality of electrical conductive wires, each electrical conductive wire arranged along the inner surface of the rigid strut and the inner surface of the leg coupled to the rigid strut.

Optionally, the flexible members are made out of an elastic material, the flexible members are arranged relative to each rigid strut and biased to apply the radial urge to the respective strut to maintain constant contact between each of the at least one contact element and the inner wall during expansion and contraction of the body lumen.

Optionally, each leg independently provides six degrees of freedom of movement to each strut.

Optionally, the flexible members are biased to urge each respective strut towards the inner wall with a force selected for gentle contact between each contact element and the inner wall.

Optionally, the treatment device further comprises a radially expanding tubular insulation member sized and shaped to fit inside the body lumen when the treatment device is in the second expanded state, at least one of the legs overlapping the insulation member, the insulation member arranged to allow the overlapping leg to position the corresponding at least one contact element.

Optionally, the treatment device is sized for deployment in a renal artery.

Optionally, the flexible members are arranged to independently position each rigid strut parallel to the long axis when contacting the inner wall.

Optionally, each leg includes a first flexible member coupled to the rigid strut at one end of the first flexible member, the first flexible member is coupled to another rigid strut at a second end thereof, the proximal or distal ends of the another rigid strut arranged to couple together approximately in the center of the expanded treatment device. Optionally, each another rigid strut is coupled to a second flexible member at an opposite end thereof, wherein the ends of each second flexible member are arranged to couple together approximately in the center. Optionally, a distally located center includes a distal hole sized for accepting a pull-wire inserted there through, the treatment device being collapsible by retraction of the pull-wire in a proximal direction, and a proximally located center is arranged to connect to a distal end of a catheter.

Optionally, a vascular catheter adapted for intravascular insertion and tissue treatment, including the treatment device disposed at a distal end portion thereof.

According to an aspect of some embodiments of the present invention there is provided a treatment system comprising: an intravascular catheter, including a treatment device at a distal end portion thereof, the treatment device comprising: a plurality of rigid struts arranged approximately in parallel to each other, each end of each rigid strut connected to a leg comprising of at least one flexible element; at least one contact element adapted for contacting an inner wall of a body lumen, each of the plurality of rigid struts coupled to one or more of the at least one contact elements; wherein the treatment device is adapted for radial expansion within the body lumen, from a first contracted state, to a second expanded state, wherein during the radial expansion the rigid struts are designed to be positioned along the circumference of the body lumen with a long axis of each strut positioned along the length of the lumen; wherein each flexible member is adapted to independently radially urge each corresponding rigid strut in at least one movement, to position at least one contact element associated with the rigid strut into contact with an inner wall of the body lumen during the second expanded state; and a controller adapted to activate the at least one contact element during contact with the inner wall of the blood vessel to treat target tissue within the blood vessel.

Optionally, the at least one contact elements are radiofrequency (RF) ablation electrodes, and the controller is adapted to activate the RF ablation electrodes to deliver at least one of unipolar and bipolar energy to the inner wall.

According to an aspect of some embodiments of the present invention there is provided a method of operation of a treatment device to treat a target tissue in a body lumen, comprising: independently radially urging in six degrees of motion, each set of at least one contact elements of a treatment device to contact with an inner wall of a blood vessel, the set of contact elements positioned around a circumference of the inner wall of the blood vessel having at least one of a non-uniform cross section and an irregular non- circular cross section, the contact element position within the lumen selected for treatment of a target tissue by selective activation of subsets of the at least one contact element.

Optionally, the at least one contact elements are radiofrequency (RF) ablation electrodes.

Optionally, each contact element is maintained in contact with the inner wall during expansion and contraction of the blood vessel.

Optionally, independently radially urging comprising yielding the position of the contact element when a sharp joint of the treatment device contacts the inner wall.

Unless otherwise defined, all technical and/or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present invention, exemplary methods and/or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

Some embodiments of the present invention are herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of embodiments of the present invention. In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the present invention may be practiced.

In the drawings:

FIG. 1 is a schematic diagram of a treatment device, optionally an ablation device, in accordance with some embodiments of the present invention;

FIG. 2 is a schematic diagram of a treatment system (optionally an ablation system) including the treatment device, in accordance with some embodiments of the present invention;

FIG. 3 is a schematic depicting additional optional features of the treatment device of FIG. 1, in accordance with some embodiments of the present invention; FIG. 4 is a schematic of the treatment device deployed within a body lumen, in accordance with some embodiments of the present invention;

FIG. 5 is a schematic diagram depicting freedom of motion of parts of the treatment device, in accordance with some embodiments of the present invention;

FIG. 6 is a schematic diagram depicting yielding of parts of the treatment device to prevent or reduce damage to the inner vessel wall, in accordance with some embodiments of the present invention;

FIG. 7 is a schematic diagram depicting deployment of the treatment device within a body lumen having a non-circular cross sectional shape, in accordance with some embodiments of the present invention;

FIG. 8 is a schematic diagram depicting deployment of the treatment device within a body lumen having a non-uniform cross sectional shape extending across a length of the lumen, in accordance with some embodiments of the present invention;

FIG. 9 is a schematic diagram depicting the treatment device adjusting to expansion and/or contraction of the body lumen; and

FIG. 10 is a flowchart of a method of operation of the treatment device and/or method of treatment using the treatment device, in accordance with some embodiments of the present invention. DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE PRESENT INVENTION

An aspect of some embodiments of the present invention relates to an intra- luminal treatment device having a flexible support that includes an elongated rigid strut, with each end of the elongated rigid strut connected to a leg comprising of flexible element(s). Optionally, the elongated rigid struts are arranged approximately parallel to each other. When the treatment device is radially expanded within a body lumen, the elongated rigid struts are designed to be positioned along the circumference of the inner wall of the body lumen, with the long axis of each rigid strut positioned along the length of the vessel. The flexibility of the flexible member-strut joint of each flexible support radially urges each strut towards the inner wall. The rigidity of the struts helps assure that contact elements coupled to the respective strut are positioned parallel to the length of the lumen and/or that the contact elements touch the inner wall. Each flexible support may be urged independently, in different movement directions (i.e., different translations distances and/or different degrees of rotation). The independent motion of each flexible support may allow the contact elements to be adjusted as needed for contact within the local region of the inner wall, such as when the inner wall is non-circular and/or the length of the vessel is non-uniform. In this manner, the flexible elements may increase the total number of contact elements of the treatment device that contact the inner wall of the non-circular and/or non-uniform lumen, in comparison, for example, with treatment devices that do not have the flexible elements.

Optionally, the treatment device is an ablation device. As used herein, the terms treatment device and ablation device are sometimes interchangeable. The contact elements may be designed for diagnostic or active treatment. Examples of contact elements designed for treatment include: radiofrequency (RF) electrodes and treatment ultrasound transducers. Examples of contact elements designed for diagnostics and/or monitoring include: electrogram sensing electrodes, temperature sensors and imaging ultrasound transducers. It is noted that the contact elements may be all of a single type, or there may be multiple different types. Optionally, the contact elements are RF ablation electrodes. As used herein, the terms contact elements and RF ablation electrodes are sometimes interchangeable.

Optionally, the flexible elements are designed to yield when pressed against the inner wall. The yielding adjusts the shape of the flexible elements, avoiding the formation of sharp corners formed at the flexible member- strut joint that would otherwise apply high pressure to the inner wall. In this manner, the flexible elements may avoid damage to the inner wall from sharp corners.

Before explaining at least one embodiment of the present invention in detail, it is to be understood that the present invention is not necessarily limited in its application to the details of construction and the arrangement of the components and/or methods set forth in the following description and/or illustrated in the drawings and/or the Examples. The present invention is capable of other embodiments or of being practiced or carried out in various ways. Referring now to the drawings, FIG. 1 is a simplified schematic illustrating an ablation device 100 having multiple flexible supports 103, each flexible support 103 including a leg 101 at each end of an elongated rigid strut 106. Each leg 101 may include one or more flexible elements 102 that independently position each set of one or more contact elements 104 coupled to each elongated rigid strut 106 against an inner wall of a body lumen, in accordance with some embodiments of the present invention.

Ablation device 100 is an example of a treatment device.

Ablation device 100 may include multiple elongated rigid struts 106, for example, four, six, eight, or other smaller, intermediate or larger numbers. Struts 106 and/or device 100 may be arranged to expand into a shape, for example, a tent and/or an umbrella and/or an expandable basket and/or a malecot. The rigid struts 106 may be designed to maintain their shape, optionally throughout the treatment cycle (i.e., expansion of the device, treatment, and compression for retraction of the device). Rigid struts 106 may not bend, and may not compress or elongate. Rigid struts 106 may be made out of a metal, for example, nickel-titanium, and stainless steel, or out of another material, such as plastic. The rigid struts which maintain their shape allow the associated legs to radially urge each respective rigid strut without reducing the rigidity along the struts. The rigidity of the strut may assure that the struts are located parallel (or approximately parallel) to each other and along the length of the lumen, and that the contact elements touch the inner wall of the lumen.

Optionally, each rigid strut 106 is coupled to a leg including at least one flexible member at each end. Optionally, when rigid struts 106 are arranged in a proximal-distal direction (e.g., parallel to the long axis of the lumen), each rigid strut 106 is coupled to a distally positioned flexible member and a proximally positioned flexible member. Rigid struts 106 may be elongated bars (e.g., round or flat) arranged parallel to the long axis of the body lumen. The flat design of struts 106, including for example, flat contact elements 104, help provide good contact with the inner vessel wall. Struts 106 may be arranged parallel to each other when ablation device 100 is expanded, and are arranged in an approximate circle to contact the circumference of the inner wall. The flexible members independently adjust the position of their respective strut 106 to contact the inner wall when the shape of the lumen is non-uniform (i.e., along the long axis) and/or non-circular (i.e., in cross section). The flexible members associated with respective struts 106 may provide different position changes to different struts 106, to allow each strut 106 to contact the inner wall.

Each rigid strut 106 is coupled to one or more contact elements 104, for example, one, two, three or four, or more. Examples of coupling methods include welded, glued, or crimped to the strut. It is noted that there may be some struts 106 without contact elements 104 or that each strut 106 includes different numbers of contact elements 104. Each contact element 104 is designed for contacting the inner wall of the body lumen in order to function, or in order to improve function and/or results. The contact elements 104 may all be of a single type, or include multiple different types. Contact elements 104 may be designed for diagnostic or active treatment. Examples of contact elements 104 designed for treatment include: radiofrequency (RF) electrodes and treatment ultrasound transducers. Examples of contact elements 104 designed for diagnostics and/or monitoring include: electrogram sensing electrodes, temperature sensors and imaging ultrasound transducers.

Ablation device 100 may be designed to be radially expanded from a contracted state, to an expanded state, and optionally compressed back to the contracted state. The state changes allow minimally invasive delivery of device 100 (e.g., percutaneously through the vasculature), expansion for treatment, and retraction for removal from the body. In the expanded state, flexible members 102 may independently position each respective rigid strut 106, urging the coupled contact elements 104 against the inner wall of the body lumen.

Optionally, device 100 is made from an elastic and/or memory material, for example, nickel-titanium.

Flexible members 102 may be made from a material having elastic and/or memory (e.g., nickel-titanium). Flexible members 102 may be designed in different shapes and/or having different dimensions to provide desired flexibility, for example, one or multiple snaking shapes (e.g., 'S\ 'W, 'Ζ', 'M', or other shapes), and/or smaller cross sectional areas than the rigid struts.

Optionally, flexible members 102 are biased to radially urge each respective strut 106 towards the inner wall with a force selected for gentle contact between each contact element 104 and the inner wall. The urging force is selected to be gentle enough to provide adequate contact for performing the treatment (and/or diagnostic) procedure using the respective contact element 104. The urging force is selected to be gentle enough to prevent or reduce damage to the inner wall, such as damage to the endothelium. The urging force, optionally in combination with the expansion force, is selected to prevent or reduce expansion in the diameter of the inner vessel wall, such as being insufficient to expand stenotic lesions.

Flexible members 102 may be located at the distal end of struts 106, at the proximal end of struts 106, or at both distal and proximal ends of struts 106.

Flexible members 102 may be designed to provide flexibility of the ablation device in the compressed state. Flexible members 102 may bend and/or yield during navigation of a torturous path, for example, as a narrow angle for example when entering the renal artery from the aorta, or when traversing other vessels or lumens to reach other treatment sites, for example, traversing the bronchial tree to reach a treatment site in the lungs.

Device 100 may be fabricated in its entirety, for example, laser cut from a tube, such as a tube of nickel titanium, or a tube of stainless steel. Alternatively, different components of device 100 are separately fabricated and assembled. Other manufacturing methods include, for example, electrical discharge machining, electrochemical machining and etching, drilling, and cutting.

It is noted that in some cases, the flexible members may not succeed in adequately positioning every contact element 104 against the inner wall, for example, in highly tortuous vessels. In such cases, a controller may selectively activate the subset of contact elements 104 that are in contact with the inner wall. Adequacy of contact may be measured by the controller, for example, by measuring impedance (e.g., between the contact element and the body lumen or between two contact elements).

Reference is now made to FIG. 2, which is a schematic diagram of an ablation system 200 including ablation device 100 and/or device 300, in accordance with some embodiments of the present invention.

System 200 includes a catheter 202, optionally an intravascular catheter, for delivery of device 100. Catheter 202 may be designed to couple to ablation device 100 at the distal end portion of catheter 202. Ablation device 100 may be coupled to catheter 202, for example, crimped or screwed on. In this manner, device 100 may be connected to catheter 202 before the procedure. Alternatively, catheter 202 is designed as a single piece, with device 100 at the distal end thereof, and may be sold as a single unit.

Different sized ablation devices 100 (and/or different sized catheters 202) may be available, and/or different devices 100 designed for different body lumens may be available. Optionally, ablation device 100 is sized for insertion into, and treatment of the renal artery, for example, to perform renal denervation. Renal denervation, is a minimally invasive, endovascular catheter based procedure using radiofrequency ablation aimed at treating resistant hypertension. Radiofrequency pulses may be applied to the inner wall of the renal arteries to ablate renal nerves. Renal denervation may cause reduction of renal sympathetic afferent and/or efferent activity, which may have physiological effects such as reducing blood pressure. During the procedure, a steerable catheter with a radio frequency (RF) energy electrode tip (e.g., as shown with reference to FIG. 2) may deliver RF energy to a renal artery via standard femoral artery access. A series of ablations may be delivered along each renal artery.

Devices 100 may be available for different treatment and/or diagnostic sessions.

Optionally, device 100 is available to perform renal denervation, including RF electrodes and optionally temperature sensors. Alternatively, device 100 or device 300 may be designed for insertion into other lumens and/or blood vessels, for example, the hepatic artery, the esophagus, the trachea. Device 100 may be designed for ablation of other tissues, for example, other nerves, or tumors (cancerous and/or benign).

Optionally, system 200 includes a controller 204 programmed to control and/or activate the contact elements. Optionally, controller 204 is programmed to activate RF electrodes on device 100 when the electrodes contacting the inner wall of the blood vessel (e.g., renal artery) to treat target tissue within the blood vessel. Optionally, controller 204 controls activation of the RF electrodes according to temperature measurements of temperature sensors (e.g., a thermocouple) on device 100.

Optionally, controller 204 is programmed to apply a method of catheter ablation using bipolar and/or unipolar ablation, e.g., to achieve a desired lesion geometry. For example, bipolar ablation between a first and a second ablation RF electrode may be used to convey an electrical signal through a target tissue to produce a lesion. Ablation may progress more quickly at the location of the first electrode than at the location of the second electrode. Bipolar ablation may optionally be paused and unipolar ablation may be initiated between the second ablation electrode and a dispersive electrode (e.g., reference electrode 408) to increase progress of ablation in the vicinity of the second electrode. A balance of unipolar and/or bipolar ablation may be used to adjust a geometry of a lesion. For example, bipolar ablation may be used to achieve spreading of a lesion along a tissue surface. For example, unipolar ablation may be used to deepen a lesion.

In some cases it may be desired to ablate tissue in a given area to an effective level (for example effective ablation may occur for heating to a temperature of between 60° and 70° C for a time between 20 and 180 sec). Tissue and/or contact with electrodes may be heterogeneous. Tissue may heat and/or ablate unevenly. Overheating and/or over-ablating tissue may have serious consequences (for example heating to over 90° C and/or over-ablating may cause blood coagulation and/or blood clots and/or damage to arteries and/or internal bleeding etc.). Controller 204 may monitor and/or control ablation within parts of the lesion to produce more even ablation. For example, a desired level of ablation may be reached in multiple regions of a lesion without over ablating any region.

Reference is now made to FIG. 3, which is a schematic of an ablation device 300, depicting additional optional features of ablation device 100 of FIG. 1, in accordance with some embodiments of the present invention. Optionally, the contact elements are RF electrodes 304, with optional temperature sensors integrated therein, or the temperate sensors as additional contact elements.

Ablation device 300 is an example of a treatment device.

Device 300 includes legs 302 coupled to elongated struts 306 at one or both ends thereof, as described herein. Optionally, each leg 302 includes a flexible member 302A coupled to an end of strut 306, and another smaller rigid strut 302B. Optionally, each smaller rigid strut 302B is connected to another flexible member 302C. The flexible members 302C may converge in the center, as described below. Alternatively, flexible members 302C are absent, and smaller rigid strut 302B converge in the center. The design of legs 302 may allow for fine adjustments of the position of strut 306, as each of flexible members 302A and 302C may independently provide freedom of movement, may independently radially urge strut 306 into position, and/or may cooperate together to provide the freedom of movement. It is noted that other designs of legs are possible, including different numbers and/or arrangements of flexible members, such as to achieve desired urging forces, desired elasticity, and/or desired translation and/or rotational limits in movement.

Legs 302 of struts 306 are arranged at the distal and/or proximal ends of device 300, to couple together approximately in the center of a cross section of the device 300, for example, legs 302 taper from the outer circumference to the center. Optionally, the distal center of device 300 includes a distal hole 308 sized for accepting a pull-wire (and/or guidewire) inserted therethrough. The ablation device may be re-collapsed by proximally pulling the pull-wire. Optionally, the proximal center of device 300 is connected to a distal end portion of a catheter 310.

Device 300 may include electrical conductive wires 312 connecting each RF electrode 304 with an RF energy source and/or RF controller (optionally located outside the body of the patient, for example, controller 204). Optionally, the RF controller includes the RF energy source. Wires 312 may be positioned along the inner surface of the respective rigid strut 306 and the inner surface of the respective leg 302 connected to the rigid strut 306. Wires 312 may run along inside catheter 310. Struts 306 may be shaped to confine wire 312, for example, as a semi-circle (or arc portion), or have elevations along the outer edges to help retain wires 312 in position.

Optionally, device 300 includes a radially expanding tubular insulation member 314. Insulation member 314 may be designed to prevent or reduce RF ablation energy from being shunted through flowing blood, improving delivery of the RF energy to the target tissue within the luminal wall. Insulation member 314 is sized and shaped to fit inside the body lumen when ablation device 300 is in the expanded state. Optionally, insulation member 314 is positioned to overlap one or more legs 302. Insulation member 314 may be arranged to allow the overlapping leg 302 to position the corresponding strut 306 and related contact element(s) 304 as described herein. Insulation member 314 may be designed and/or positioned to not hinder the movement of leg 302, for example, by being elastic and/or including slack. Additional details of insulation member 314 are described, for example, in International Patent Application Publication Nos. WO2014/118733 and/or WO2014/118734.

It is noted that as used herein, the terms flexible member and leg are sometimes interchangeable. Reference is now made to FIG. 4, which is a schematic of ablation device 300 (or ablation device 100) deployed within a body lumen 402, in accordance with some embodiments of the present invention. Optionally, body lumen 402 is a blood vessel, optionally an artery, optionally one of the renal arteries (left or right). Device 300 is positioned using antegrade navigation of positioning catheter 310, such that blood flowing in the direction of arrows 406 flows over the proximal portion of catheter 310 towards device 300. The insulation member may be designed to provide insulation based on the antegrade blood flow direction. It is noted that device 300 may be positioned using a retrograde approach, positioned such that blood flows in the opposite direction, which may require a different design for the insulation member according to the direction of blood flow.

Flexible members 302A and 302C may independently position each strut and related RF electrode(s) 304 towards an inner wall 404 of blood vessel 402.

Each ablation electrode 304 may be made, for example, of between 80% and 95% Platinum and/or between 20% and 5% Iridium. The ablation electrodes may range for example between 0.5 and 4 millimeters (mm) long and/or have an electrically active area for example of between 0.1 and 1 mm and/or have a diameter ranging from 0.01 to 0.05 inch (0.25 to 1.27 mm). The electrically active area of the ablation electrodes may be in contact with a target tissue. The distance between ablation electrodes may range for example between 0.5 and 3 mm or more.

It is noted that catheter 310 may include a unipolar reference electrode 408 located proximally in reference to device 300, when device 300 is performing ablation therapy.

Reference electrode 408 may have a length ranging, for example, between 4 to 20 mm and/or have a diameter ranging between 2 and 5 French (between 0.67 and 1.67 mm). The reference electrode may have an electrically active area ranging, for example, 20 to 50 times or more than the electrically active area and/or surface of contact of the ablation electrodes. For example the electrically active area of the reference electrode may range between 50 to 150 mm 2 (e.g., between 50 to 100 mm 2 , between 100 to 150 mm 2 , or between 75 to 120 mm 2 ). Optionally the electrically active surface of the reference electrode may be in electrical contact with a fluid in a lumen of a patient. The reference electrode may be coated with a material such as porous titanium nitride (TiN) or iridium oxide (IrOx). The coating may increase microscopic surface area of the reference electrode in electrical contact with lumen fluid.

Reference is now made to FIG. 5, which is a schematic diagram depicting freedom of motion of parts of ablation device 300 and/or device 100, in accordance with some embodiments of the present invention. Line 550 depicts a long axis of the ablation device, which may be defined by a guidewire.

The flexible members and/or legs may independently provide multiple degrees of freedom of motion to separately move each strut and associated contact elements, as described herein. One, several, or all of the following motions may be provided by the flexible members to each strut, represented by respective arrows: up and/or down translation 502, left and/or right translation 504, forward and/or backwards translation (may also be referred to as distal and/or proximal) 506, forward and/or backwards tilt (may also be referred to as pitch) 508, swivel left and/or right (may also be referred to as yaw) 510, and left and/or right pivot (may also be referred to as roll) 512.

The flexible members may be designed to allow translation movement (i.e., 502,

504, and/or 506) of about 0-5 millimeters (mm), or about 1-3 mm, or about 0-2 mm, or other smaller, intermediate or larger ranges. The flexible members may be allows to allow rotational movement (i.e., 508, 510, and/or 512) or about 0-60 degrees, or about 15-45 degrees, or about 0-30 degrees, or other smaller, intermediate or larger ranges.

Reference is now made to FIG. 6, which is a schematic diagram depicting yielding of parts of an ablation device 600 (e.g., device 300 and/or 100) to avoid damage to an inner vessel wall 620, in accordance with some embodiments of the present invention. Optionally, flexible members 602 are made from an elastic material and/or biased to yield when contacting the inner wall.

As shown, device 600 expands unevenly and/or along an axis congruent to the long axis of the lumen. Similarly, device 600 may expand (evenly or unevenly, parallel or congruent) within a non-circular and/or non-uniform lumen.

A potential high pressure region 622, which may be formed by a bend in the joint between strut 606 and flexible member 602, or by a bend in flexible member 602 itself, contacts inner vessel wall 620. Flexible member 602 yields, changing position and/or shape, to increase the contact area of and/or move high pressure region 622. Flexible member 622 may yield in a direction 624 away from inner vessel wall 620. Alternatively or additionally, flexible member 622 may adjust shape and/or position, up tilting 626 strut 606, which increases the surface area and/or reduces the sharp bend of region 622. In this manner, the yielding prevents or reduces damage to inner vessel wall 620.

Reference is now made to FIG. 7, which is a schematic diagram depicting deployment of an ablation device 700 (e.g., device 100 and/or 300) within a body lumen 720 having a non-uniform cross sectional shape extending across a portion of a length of the lumen, in accordance with some embodiments of the present invention. Device 700 within lumen 720 is shown from a side view.

As shown, the flexible members independently urge and/or position each strut 706 and related contact elements 704 against the inner wall of lumen 720. Where lumen 720 is narrower, flexible members 702A take on a '<' type shape, having a narrower angle between flexible members of respective struts. Where lumen 720 is wider, flexible members 702B are almost in a straight line, having a large angle.

Reference is now made to FIG. 8, which is a schematic diagram depicting deployment of an ablation device 800 (e.g., device 100 and/or 300) within a body lumen 820 having a non-circular cross sectional shape, such as defined by a bulge 822, in accordance with some embodiments of the present invention. Bulge 822 may be, for example, an atherosclerotic plaque, a tumor, and/or scar tissue.

Ablation device 800 expands to form an asymmetrical cross sectional shape according to the asymmetrical cross sectional shape of the inner wall of body lumen 820. Each strut and associated contact element are independently urged and/or positioned into contact with the inner wall by associated flexible members. For example, as depicted, flexible member 802A expands a shorter distance than another flexible member 802B, to urge associated strut 806A and related contact element 804A against bulge 822. Flexible member 802B expands a longer distance than flexible member 802A, to urge associated strut 806B and related contact element 804B against the inner wall.

Reference is now made to FIG. 9, which is a schematic diagram depicting an ablation device 900 (e.g., device 300 and/or 100) adjusting to expansion and/or contraction of a body lumen 920, such as a blood vessel, optionally an artery such as the renal artery. Diagram 922A depicts the contracted state of the lumen 920, for example, as occurring during the normal cardiac cycle, due to a spasm occurring during treatment of the vessel wall, and/or due to administration of a vasoconstrictive drug. Diagram 922B depicts the expanded state of lumen 920, for example, as occurring due to the normal cardiac cycle, relaxation after the spasm, and/or due to administration of a vasodilative drug. It is noted that the expanded or contracted state may be the normal state of the lumen, or the normal state being in between the expanded and contracted states.

Flexible members 902 may adjust their position and/or shape during changes between the contracted and expanded states, maintaining constant contact between each contact element 904 of associated struts 906, and the inner wall of lumen 920 during expansion and contraction of the body lumen. As shown, during contraction 922A, flexible members 902 of different struts form a narrow angle in relation to each other. The angle increases during the expansion state 922B.

Reference is now made to FIG. 10, which is a flowchart of a method of treatment using the ablation device (e.g., device 100 or 300), which includes a method of operation of the ablation device, in accordance with some embodiments of the present invention. The method may be used for performing intravascular ablation of target tissue, optionally using unipolar and/or bipolar RF energy application, for example, as described with reference to International Patent Application Publication Nos. WO2014/118733 and/or WO2014/118734.

At 1002, an appropriate ablation device may be selected, for example, according to the size of the target vessel, according to delivery method (e.g., via catheter), and/or according to the treatment (e.g., using RF electrodes for ablation).

At 1004, the ablation device may be delivered to the target lumen, for example, using a catheter (e.g., catheter 202), through femoral artery or vein access, and delivered via blood vessels.

At 1006, the ablation device may be expanded within the target blood vessel.

Optionally, the ablation device self-expands upon release from the catheter and/or retraction of an outer sheath. The device may expand into a shape, for example, a tent and/or an umbrella and/or an expandable basket and/or a malecot.

At 1008, each set of electrodes associated with each strut may be automatically independently settled in contact with the inner wall of the target blood vessel by associated flexible members, as described herein. The independent radial urging of each strut and associated contact element(s) into contact with the radial wall is performed automatically by the device itself, without necessarily requiring operator control and/or intervention.

The electrodes may be positioned around the inner circumference of the blood vessel. The blood vessel may have a non-uniform cross section and/or an irregular non- circular cross section, as described herein.

The flexible members may yield to prevent or reduce damage to the inner wall, such as during deployment, as described herein.

The contact of the electrodes with the target tissue may be tested. For example, the impedance may be measured between different electrodes (e.g., one ablation electrode and a dispersive electrode for unipolar RF ablation) and/or the temperature may be tested at the ablation electrode while applying current. If the contact is not good, for example, the impendence is high, then the ablation electrode may be repositioned, for example by re-inserting the catheter and/or moving and/or re-positioning and/or retracting and re-expanding the ablation device.

Optionally, at 1010, each electrode may be maintained in contact with the inner wall during expansion and contraction of the blood vessel, as described herein.

At 1012, one or more electrodes (e.g., subsets of electrodes that are in contact with the inner wall) may be activated to ablate the tissue. Other treatments may be possible (e.g., denervation, electrical or mechanical stimulation). Sensors in contact with the inner wall may be used to monitor the treatment, for example, temperature sensors.

At 1014, the ablation device may be re-contracted, for example, by retraction into the sheath. The ablation device is removed from the body of the patient.

The elasticity of the flexible members may be further designed to allow struts of the ablation device to be easily collapsed back together again, such as upon retraction back into the outer sheath.

It is expected that during the life of a patent maturing from this application many relevant ablation devices and electrodes will be developed and the scope of the terms ablation device and electrodes are intended to include all such new technologies a priori.

As used herein the term "about" refers to ± 10 %.

The terms "comprises", "comprising", "includes", "including", "having" and their conjugates mean "including but not limited to".

The term "consisting of means "including and limited to". The term "consisting essentially of" means that the composition, method or structure may include additional ingredients, steps and/or parts, but only if the additional ingredients, steps and/or parts do not materially alter the basic and novel characteristics of the claimed composition, method or structure.

As used herein, the singular form "a", "an" and "the" include plural references unless the context clearly dictates otherwise. For example, the term "a compound" or "at least one compound" may include a plurality of compounds, including mixtures thereof. Throughout this application, various embodiments of this present invention may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the present invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

Whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range. The phrases "ranging/ranges between" a first indicate number and a second indicate number and "ranging/ranges from" a first indicate number "to" a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numerals therebetween.

As used herein the term "method" refers to manners, means, techniques and procedures for accomplishing a given task including, but not limited to, those manners, means, techniques and procedures either known to, or readily developed from known manners, means, techniques and procedures by practitioners of the chemical, pharmacological, biological, biochemical and medical arts.

As used herein, the term "treating" includes abrogating, substantially inhibiting, slowing or reversing the progression of a condition, substantially ameliorating clinical or aesthetical symptoms of a condition or substantially preventing the appearance of clinical or aesthetical symptoms of a condition. It is appreciated that certain features of the present invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the present invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as suitable in any other described embodiment of the present invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.

Although the present invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.

All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting.

Claims

WHAT IS CLAIMED IS:

1. A treatment device for intraluminal insertion and treatment, comprising: a plurality of rigid struts arranged approximately in parallel to each other, each end of each rigid strut connected to a leg comprising of at least one flexible element;

at least one contact element adapted for contacting an inner wall of a body lumen, each of the plurality of rigid struts coupled to one or more of the at least one contact element;

wherein the treatment device is adapted for radial expansion within the body lumen, from a first contracted state, to a second expanded state, wherein during the radial expansion the rigid struts are designed to be positioned along the circumference of the body lumen with a long axis of each strut positioned along the length of the lumen;

wherein each flexible member is adapted to independently radially urge each corresponding rigid strut in at least one movement, to position at least one contact element associated with the rigid strut into contact with an inner wall of the body lumen during the second expanded state.

2. The treatment device of claim 1, wherein the treatment device is expanded to the second expanded state to form an asymmetrical cross sectional shape according to the asymmetrical cross sectional shape of the inner wall of the body lumen, and each of the coupled flexible members independently positions each rigid strut and associated at least one contact element to contact the asymmetrical cross sectional shape of the inner wall.

3. The treatment device of claim 1, wherein the treatment device is expanded to the second expanded state to form a non-uniform cross section along a length of the body lumen according to the non-uniform cross section of the length of the inner wall of the body lumen, and each of the coupled flexible members independently positions each rigid strut and associated at least one contact element to contact the nonuniform cross section along the length of the inner wall.

4. The treatment device of claim 1, wherein the flexible members are made from an elastic material and are biased to yield when contacting the inner wall during expansion of the treatment device to avoid contact of a sharp corner formed by a flexible member-strut joint with the inner wall.

5. The treatment device of claim 1, wherein the at least one contact element is a radio frequency (RF) ablation electrode adapted for ablation of a target tissue when energy is applied to the RF electrode contacting the inner wall of the body lumen.

6. The treatment device of claim 1, further comprising a plurality of electrical conductive wires, each of the at least one contact elements coupled to at least one of the plurality of electrical conductive wires, each electrical conductive wire arranged along the inner surface of the rigid strut and the inner surface of the leg coupled to the rigid strut.

7. The treatment device of claim 1, wherein the flexible members are made out of an elastic material, the flexible members are arranged relative to each rigid strut and biased to apply the radial urge to the respective strut to maintain constant contact between each of the at least one contact element and the inner wall during expansion and contraction of the body lumen.

8. The treatment device of claim 1, wherein each leg independently provides six degrees of freedom of movement to each strut.

9. The treatment device of claim 1, wherein the flexible members are biased to urge each respective strut towards the inner wall with a force selected for gentle contact between each contact element and the inner wall.

10. The treatment device of claim 1, further including a radially expanding tubular insulation member sized and shaped to fit inside the body lumen when the treatment device is in the second expanded state, at least one of the legs overlapping the insulation member, the insulation member arranged to allow the overlapping leg to position the corresponding at least one contact element.

11. The treatment device of claim 1, wherein the treatment device is sized for deployment in a renal artery.

12. The treatment device of claim 1, wherein the flexible members are arranged to independently position each rigid strut parallel to the long axis when contacting the inner wall.

13. The treatment device of claim 1, wherein each leg includes a first flexible member coupled to the rigid strut at one end of the first flexible member, the first flexible member is coupled to another rigid strut at a second end thereof, the proximal or distal ends of the another rigid strut arranged to couple together approximately in the center of the expanded treatment device.

14. The treatment device of claim 13, wherein each another rigid strut is coupled to a second flexible member at an opposite end thereof, wherein the ends of each second flexible member are arranged to couple together approximately in the center.

15. The treatment device of claim 14, wherein a distally located center includes a distal hole sized for accepting a pull- wire inserted there through, the treatment device being collapsible by retraction of the pull-wire in a proximal direction, and a proximally located center is arranged to connect to a distal end of a catheter.

16. A vascular catheter adapted for intravascular insertion and tissue treatment, including the treatment device of claim 1 disposed at a distal end portion thereof.

17. A treatment system comprising: an intravascular catheter, including a treatment device at a distal end portion thereof,

the treatment device comprising:

a plurality of rigid struts arranged approximately in parallel to each other, each end of each rigid strut connected to a leg comprising of at least one flexible element;

at least one contact element adapted for contacting an inner wall of a body lumen, each of the plurality of rigid struts coupled to one or more of the at least one contact elements;

wherein each flexible member is adapted to independently radially urge each corresponding rigid strut in at least one movement, to position at least one contact element associated with the rigid strut into contact with an inner wall of the body lumen during the second expanded state; and

a controller adapted to activate the at least one contact element during contact with the inner wall of the blood vessel to treat target tissue within the blood vessel.

18. The system of claim 17, wherein the at least one contact elements are radiofrequency (RF) ablation electrodes, and the controller is adapted to activate the RF ablation electrodes to deliver at least one of unipolar and bipolar energy to the inner wall.

19. A method of operation of a treatment device to treat a target tissue in a body lumen, comprising:

independently radially urging in six degrees of motion, each set of at least one contact elements of a treatment device to contact with an inner wall of a blood vessel, the set of contact elements positioned around a circumference of the inner wall of the blood vessel having at least one of a non-uniform cross section and an irregular non- circular cross section, the contact element position within the lumen selected for treatment of a target tissue by selective activation of subsets of the at least one contact element.

20. The method of claim 19, wherein the at least one contact elements are radiofrequency (RF) ablation electrodes.

21. The method of claim 19, wherein each contact element is maintained in contact with the inner wall during expansion and contraction of the blood vessel.

22. The method of claim 19, wherein independently radially urging comprising yielding the position of the contact element when a sharp joint of the treatment device contacts the inner wall.