Ablation catheter with pressure sensor for treating varicose veins

Abstract

A catheter for use in treating aneurysms may include a handle, an elongate shaft connected to the handle, and a heating element disposed near the distal end of the shaft. In some embodiments, the heating element may include a plurality of pressure sensors that are circumferentially offset from each other, and each pressure sensor is configured to generate an output signal indicative of the pressure applied to each pressure sensor by the surface of the target blood vessel.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to medical devices, systems, and methods for providing therapeutic thermal treatments, and more particularly, to medical devices, systems, and methods for providing therapeutic thermal treatments for venous disease. [Background technology]

[0002] Therapeutic heat treatments can be used to treat a wide variety of medical conditions, such as tumors, fungal growths, etc. Heat treatments can be used in conjunction with other treatment modalities or as the sole treatment modality to treat medical conditions. Because heat treatments provide localized heating, they do not cause cumulative toxicity, in contrast to other treatment modalities, such as drug-based treatments.

[0003] One exemplary clinical application of therapeutic thermal treatment is the treatment of chronic venous disease, such as varicose veins, which may become enlarged and / or tortuous due to one or more pathological conditions. The application of sufficient thermal energy via an intravascular device can treat varicose veins by shrinking or occluding the targeted veins.

[0004] There is a continuing need for improved devices and methods for providing focused, controlled thermal energy for the thermal treatment of chronic venous conditions, such as varicose veins, while minimizing or eliminating effects on surrounding healthy tissue. Summary of the Invention

[0005] In Example 1, a device for treating varicose veins includes an elongate catheter. The elongate catheter may include an elongate shaft having a proximal end and a distal end defining a longitudinal axis, a heating element disposed near the distal end of the elongate shaft, and a plurality of pressure sensors disposed longitudinally spaced apart from one another along the shaft. The shaft may be sized and configured so that the distal end can be inserted into a target blood vessel. The heating element may include a coil member having a plurality of first windings wound in a first direction around the shaft, with a plurality of openings in the plurality of first windings defined along the length of the heating element. Each of the plurality of pressure sensors may be disposed on the shaft within a respective one of the plurality of openings in the plurality of first windings, with adjacent pressure sensors being circumferentially offset from one another, and each pressure sensor configured to generate an output signal indicative of pressure exerted on each pressure sensor by the surface of the target blood vessel.

[0006] In Example 2, the device of Example 1, wherein the coil member further includes a plurality of second windings wound around the shaft in a second direction different from the first direction, at least some of the plurality of second windings intersecting the plurality of first windings at a plurality of spaced apart locations along the length of the heating element, and at least some of the plurality of openings being defined between the plurality of first windings and the plurality of second windings.

[0007] In Example 3, in the device of either Example 1 or 2, the plurality of pressure sensors includes three pressure sensors, and two adjacent pressure sensors of the plurality of pressure sensors are circumferentially offset from each other by an offset degree associated with N.

[0008] In Example 4, in the device of Example 1, the plurality of pressure sensors includes a first pressure sensor pair and a second sensor pair, the first pressure sensor pair including a first pressure sensor and a second pressure sensor adjacent to the first pressure sensor, the second pressure sensor being circumferentially offset by a first offset angle relative to the first pressure sensor, and the second sensor pair including a third pressure sensor and a fourth pressure sensor adjacent to the third pressure sensor, the fourth pressure sensor being circumferentially offset by a second offset angle relative to the third pressure sensor, the second offset angle being equal to the first offset angle.

[0009] In Example 5, in the device of Example 1, the first plurality of windings and the second plurality of windings are arranged to define a plurality of coil segments, adjacent coil segments being longitudinally spaced from one another and defining one or more segment gaps between each adjacent coil segment along the length of the shaft, and the device further includes a temperature sensor disposed in one of the one or more segment gaps, and at least one pressure sensor of the plurality of pressure sensors is disposed in an opening in the coil segment.

[0010] In Example 6, in the device of Example 1, the plurality of pressure sensors includes six pressure sensors. In Example 7, in the device of Example 6, two adjacent pressure sensors of the plurality of pressure sensors are circumferentially offset by 60 degrees from each other.

[0011] In Example 8, in the device of Example 6, two adjacent pressure sensors of the plurality of pressure sensors are circumferentially offset by 120 degrees from each other. In Example 9, in the device of any of Examples 1 to 8, the plurality of pressure sensors includes at least one selected from the group consisting of a piezoelectric pressure sensor, a capacitive pressure sensor, an inductive pressure sensor, a strain gauge pressure sensor, and a potentiometric pressure sensor.

[0012] In Example 10, in the device of any of Examples 1-8, the heating element is controlled to deliver ablation energy when an output signal indicative of pressure generated by one of the plurality of pressure sensors is greater than a predetermined threshold.

[0013] In Example 11, a device for treating varicose veins includes an energy generator configured to generate an electrical signal, a controller operably connected to the energy generator and controlling the generation of the electrical signal, and an elongate catheter connected to the energy generator, the elongate catheter including an elongate shaft having a proximal end and a distal end defining a longitudinal axis, the distal end sized and configured for insertion into a target blood vessel, a heating element disposed near the distal end of the elongate shaft, and a plurality of pressure sensors disposed longitudinally spaced from one another along the shaft. The heating element may include a first coil member having a first plurality of windings wound about a shaft, wherein one or more first openings in the first plurality of windings are defined along a length of the first coil member, and a second coil member having a second plurality of windings wound about the shaft, wherein one or more second openings in the second plurality of windings are defined along a length of the second coil member. Each pressure sensor of the plurality of pressure sensors is disposed on the shaft within a respective one of the first openings in the first plurality of windings or the second openings in the second plurality of windings, wherein at least two adjacent pressure sensors are circumferentially offset from one another, and each pressure sensor is configured to generate an output signal indicative of pressure applied to the respective pressure sensor by the surface of the target blood vessel. In some embodiments, the first and second coil members are each operably connected to an energy generator and configured to generate thermal energy when an electrical signal generated by the energy generator is delivered to the first and second coil members.

[0014] In Example 12, in the device of Example 11, the heating element further includes a third coil member having a third plurality of windings wound around the shaft, one or more third openings in the third plurality of windings defined along a length of the third coil member, and one or more of the plurality of pressure sensors disposed on the shaft within one or more of the third openings.

[0015] In Example 13, in the device of Example 11, the controller is configured to adjust the current generated by the energy generator based on an output signal generated by each pressure sensor of the plurality of pressure sensors indicative of a pressure applied to each pressure sensor.

[0016] In Example 14, in the device of any of Examples 11-13, the controller is configured to control the current generated by the energy generator to be selectively delivered to one or both of the first and second coil members.

[0017] In Example 15, the device of any of Examples 11-14 further includes a temperature sensor disposed on the shaft within one of the first opening or the second opening, the temperature sensor being longitudinally spaced along the shaft from one of the plurality of pressure sensors.

[0018] While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a schematic diagram of an exemplary ablation device for treating chronic venous disease, e.g., varicose veins, in accordance with an embodiment of the present disclosure. [Figure 2A]1 is a schematic diagram of an exemplary ablation catheter including a connector for treating chronic venous disease, e.g., varicose veins, in accordance with an embodiment of the present disclosure. [Figure 2B] 2B is a schematic cross-sectional view of a connector of the exemplary ablation catheter of FIG. 2A in accordance with an embodiment of the present disclosure. [Figure 3A] FIG. 1 is a schematic front view of a distal end portion of an ablation catheter, in accordance with an embodiment of the present disclosure. [Figure 3B] 1 is a schematic, partially enlarged view of a distal end portion of an ablation catheter, according to an embodiment of the present disclosure. [Figure 3C] 1 is a schematic partial cross-sectional view of a distal end portion of an ablation catheter according to an embodiment of the present disclosure. [Figure 4] 1 is a schematic diagram of a distal end portion of an ablation catheter in accordance with an embodiment of the present disclosure. [Figure 5] 1 is a schematic diagram of a distal end portion of an ablation catheter in accordance with an embodiment of the present disclosure. [Figure 6] 1 is a schematic diagram of a distal end portion of an ablation catheter in accordance with an embodiment of the present disclosure. [Figure 7] 1 is a schematic diagram of a distal end portion of an ablation catheter in accordance with an embodiment of the present disclosure. [Figure 8A] FIG. 1 is a schematic front view of a distal end portion of an ablation catheter, in accordance with an embodiment of the present disclosure. [Figure 8B] 1 is a schematic partial cross-sectional view of a distal end portion of an ablation catheter according to an embodiment of the present disclosure. [Figure 8C] 1 is a schematic projection view of a distal end portion of an ablation catheter according to an embodiment of the present disclosure. [Figure 9] 1 is a schematic diagram of a distal end portion of an ablation catheter in accordance with an embodiment of the present disclosure. [Figure 10] 1 is a schematic diagram of a distal end portion of an ablation catheter in accordance with an embodiment of the present disclosure. [Figure 11A]1 is a schematic illustration of a portion of an ablation catheter for use within a target vessel of a patient for the treatment of varicose veins, in accordance with an embodiment of the present disclosure. [Figure 11B] 1 is a schematic illustration of a portion of an ablation catheter for use within a target vessel of a patient for the treatment of varicose veins, in accordance with an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0020] While the invention is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the invention to the specific embodiments described. On the contrary, the invention is intended to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims.

[0021] The following detailed description is exemplary in nature and is not intended to limit the scope, applicability, or configuration of the present invention in any way. Rather, the following description provides some practical illustrations for implementing exemplary embodiments of the present invention. Examples of configurations, materials, and / or dimensions are provided for selected elements. Those skilled in the art will recognize that there are various suitable alternatives to many of the described examples.

[0022] Therapeutic heat treatments can be used to treat a wide variety of medical conditions, including chronic venous diseases such as varicose veins, which may be enlarged and / or tortuous due to one or more pathological conditions. The application of sufficient thermal energy via an intravascular device can treat varicose veins by shrinking or occluding the targeted vein.

[0023] An exemplary catheter for use in treating varicose veins may include a handle, an elongate shaft connected to the handle, and a heating element disposed near the distal end of the shaft. In some embodiments, the heating element may include a coil that receives an electrical current (e.g., alternating current, direct current) provided by an energy generator to generate and deliver thermal ablation energy. In certain embodiments, the heating element may include a coil that receives an electrical signal (e.g., high-frequency alternating current) generated by an energy generator to generate and deliver radiofrequency ablation energy.

[0024] As described above, there is a continuing need for improved devices and methods for providing focused, controlled thermal energy for thermally treating chronic venous conditions, such as varicose veins, while minimizing or eliminating impact on surrounding healthy tissue. For example, physicians must ensure that the shaft containing the heating element fits within the vein and makes good contact with the target treatment site within the vein. Insufficient contact between the vein wall and the heating element can result in reduced efficiency and prolonged treatment time in treating the condition, or ineffective treatment results. Therefore, by measuring the pressure locally within the target blood vessel in real time, physicians can better determine treatment conditions (e.g., temperature, time, etc.) for better treatment results and efficiency.

[0025] Some embodiments of the present disclosure describe a catheter having an elongate shaft having proximal and distal ends defining a longitudinal axis and a heating element disposed near the distal end of the shaft. In some embodiments, the heating element may include a coil member having a plurality of first windings wound in a first direction around the shaft, with a plurality of openings in the plurality of first windings defined along the length of the heating element. In exemplary embodiments, the catheter may further include a plurality of pressure sensors disposed longitudinally spaced from one another along the shaft, each of the pressure sensors disposed on the shaft within a respective one of the plurality of openings in the plurality of first windings, adjacent pressure sensors being circumferentially offset from one another, and each pressure sensor configured to generate an output signal indicative of pressure exerted by the surface of a target blood vessel on each pressure sensor.

[0026] 1 is a schematic diagram of an exemplary ablation device 100 for treating chronic venous disease, e.g., varicose veins, in accordance with an embodiment of the present disclosure. The ablation device 100 includes an ablation catheter 102 including a handle 104, an elongate shaft 106 having a proximal end 108 and a distal end portion 110 terminating at a distal end 112, and a heating element 114 disposed near the distal end 112 of the elongate shaft 106. The shaft 106 is sized and configured so that the distal end 112 can be inserted into a target blood vessel. The heating element 114 is configured to deliver ablation energy (e.g., radiofrequency energy, thermal energy) to the wall of the target blood vessel.

[0027] The device 100 may include an energy generator 116 electrically coupled to the handle 104 via a connector 118 and configured to generate energy by providing an electrical signal (e.g., an electric current, a high-frequency alternating current). A controller 120 is operably connected to the energy generator 116 and controls the generation of the electrical signal. The controller 120 may be implemented using firmware, integrated circuits, and / or software modules that interact with or are combined together. For example, the controller 120 may include a memory 122 that stores computer-readable instructions / code 124 for execution by a processor 126 (e.g., a microprocessor) to perform aspects of the method embodiments described herein.

[0028] In certain embodiments, the heating element 114 employs structural features and / or components to improve the clinical performance of the ablation catheter 102 and enhance manufacturability. In some embodiments, the heating element 114 may include two or more coils with windings wound in different directions around the shaft 106, where the two or more coils cross each other at multiple locations along the shaft 106, for example, resulting in a larger diameter of the heating element 114. In certain embodiments, the two or more coils may be fabricated from individual conductor wires, and the controller 120 is configured to adjust the power of the treatment by selectively supplying current and / or specific currents (e.g., different currents) generated by the energy generator 116 to the two or more conductor wires. In some embodiments, the heating element 114 includes multiple coil segments, where one or more coil segments are configured to be individually controlled and / or addressed. In certain embodiments, the one or more coil segments include two or more coils with windings wound in one or more directions. In some embodiments, one or more coil segments include two or more coils that cross each other at one or more locations.

[0029] In some embodiments, controller 120 may be configured to communicate with various components of device 100 and to generate a graphical user interface (GUI) that is displayed via display 128. Controller 120 may include any type of computing device suitable for implementing embodiments of the present disclosure. Examples of computing devices include workstations, servers, laptops, portable devices, desktops, tablet computers, handheld devices, special-purpose computing devices such as general-purpose graphics processing units (GPGPUs), and general-purpose computing devices, all of which are contemplated within the scope of FIG. 1 with reference to the various components of device 100.

[0030] In some embodiments, controller 120 includes buses that directly and / or indirectly couple devices such as a processor, memory, input / output (I / O) ports, I / O components, and power supplies. Any number of additional components, different components, and / or combinations of components may also be included in a computing device. Bus refers to one or more buses (e.g., an address bus, a data bus, or a combination thereof). Similarly, in some embodiments, a computing device may include multiple processors, multiple memory components, multiple I / O ports, multiple I / O components, and / or multiple power supplies. Additionally, any number of these components, or combinations thereof, may be distributed and / or replicated across multiple computing devices.

[0031] In some embodiments, memory 122 includes computer-readable media in the form of volatile and / or non-volatile memory, transient and / or non-transitory storage media, and may be removable, non-removable, or a combination thereof. Examples of media include random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory, optical or holographic media, magnetic cassettes, magnetic tape, magnetic disk storage devices or other magnetic storage devices, data transmission, and / or any other medium that can be used to store information and that can be accessed by a computing device, such as, for example, quantum state memory, and / or the like. In some embodiments, memory 122 stores computer-executable instructions that cause a processor (e.g., controller 120) to implement aspects of embodiments of the system components described herein and / or perform aspects of embodiments of the methods and procedures described herein.

[0032] The computer-executable instructions 124 may include, for example, computer code, machine-usable instructions, program components, etc., executable by, for example, one or more processors associated with a computing device. The program components may be programmed using any number of different programming environments, including various languages, development kits, frameworks, and / or the like. Some or all of the functionality contemplated herein may also or alternatively be implemented in hardware and / or firmware.

[0033] In some embodiments, memory 122 may include a data repository implemented using any one of the configurations described below. The data repository may include random access memory, flat files, XML files, and / or one or more database management systems (DBMS) running on one or more database servers or data centers. The database management system may be a relational (RDBMS), hierarchical (HDBMS), multidimensional (MDBMS), object-oriented (ODBMS or OODBMS), or object-relational (ORDBMS) database management system, etc. The data repository may be, for example, a single relational database. In some cases, the data repository may include multiple databases that can exchange and aggregate data through a data integration process or software application. In exemplary embodiments, at least a portion of the data repository may be hosted in a cloud data center. In some cases, the data repository may be hosted on a single computer, server, storage device, cloud server, or the like. In some other cases, the data repository may be hosted on a series of networked computers, servers, or devices. In some cases, the data repository may be hosted on tiered data storage devices, including local, regional, and central.

[0034] Various components of device 100 may communicate or be coupled to communication interfaces, such as, for example, wired or wireless interfaces. Communication interfaces include, but are not limited to, wired or wireless short-range and long-range communication interfaces. Wired interfaces may be cables, umbilicals, and the like. Short-range communication interfaces may be interfaces that comply with known communication standards, such as, for example, a local area network (LAN), Bluetooth® standard, IEEE 702 standard (e.g., IEEE 702.11), ZigBee® or similar specifications (e.g., based on the IEEE 702.15.4 standard), or other public or proprietary wireless protocols. Long-range communication interfaces may be, for example, a wide area network (WAN), a cellular network interface, a satellite communication interface, or the like. Communication interfaces may be within a private computer network, such as an intranet, or over a public computer network, such as the Internet.

[0035] Figure 2A is a schematic illustration of an exemplary ablation catheter 200 including a connector 218 (similar to connector 118 as shown in Figure 1) for treating chronic venous disease, e.g., varicose veins. Figure 2B is a schematic cross-sectional view of connector 218 of exemplary ablation catheter 200 along section line 2B-2B of Figure 2A, in accordance with an embodiment of the present disclosure.

[0036] As shown, the ablation catheter 200 includes a handle 204, an elongate shaft 206 having a proximal end 208 and a distal end portion 210 terminating in a distal end 212, and a heating element 214 disposed near the distal end 212 of the elongate shaft 206. The shaft 206 is sized and configured so that the distal end 212 can be inserted into a target blood vessel. The heating element 214 is configured to deliver ablation energy (e.g., radiofrequency energy, thermal energy) to the wall of the target blood vessel.

[0037] In some embodiments, connector 218 includes pins 242 (e.g., including pins 242a and 242b) and pins 244 (e.g., including pins 244a and 244b) of different sizes. Pin 242 is relatively smaller than pin 244 and is configured to transmit an electrical signal (e.g., an electrical signal generated by energy generator 116 of FIG. 1 ). Exemplary electrical signals may include a thermocouple signal or a pressure signal. Pin 244 is relatively larger than pin 242 and may be configured to pass an electrical current from an energy generator (e.g., energy generator 116 of FIG. 1 ) to generate heat in heating element 214. One of pins 244 may be used as a pin connected to ground (i.e., a ground pin). In some embodiments where the heating element includes multiple heating segments (e.g., coil segments), the ground pin may be used as a common ground pin by the multiple heating segments.

[0038] 3A-3C include a schematic front view, a partial enlarged view, and a partial cross-sectional view, respectively, of an example distal end portion 300 of an ablation catheter, according to an embodiment of the present disclosure. In some embodiments, the distal end portion 300 of an ablation catheter (e.g., ablation catheter 102 of FIG. 1 , ablation catheter 200 of FIG. 2A ) includes a portion of an elongate shaft 302 terminating in a distal end 304, also referred to as the distal end portion of the shaft 302, and a heating element 306 disposed near the distal end 304 of the elongate shaft 302. The shaft 302 is sized and configured so that the distal end 304 can be inserted into a target blood vessel.

[0039] The heating element 306 includes a first heating coil 308 having a plurality of first windings 310 wound in a first direction 312 (indicated by the arrow about reference point A) and a second heating coil 314 having a plurality of second windings 316 wound in a second direction 318 (indicated by the arrow about reference point A). As shown, the first direction 312 is different from the second direction 318, and the second windings 316 intersect with the first windings 310 at a plurality of spaced apart locations along the length (L) of the distal end portion 300 of the shaft 302. In some embodiments, the length (L) can be from about 2 cm to about 10 cm. In some embodiments, the length (L) can be from about 3 cm to about 8 cm. In an exemplary embodiment, the length (L) can be from about 5 cm to about 7 cm. The windings 310 and 316 may be wound around the shaft 302 using a winding machine to achieve tighter and smoother heating coils 308 and 314 around the shaft 302 .

[0040] FIG. 3B is a partial enlarged view of an example of a distal tip portion 300 of an ablation catheter, indicated by circle 3B in FIG. 3A. As shown, coil 308 can include conductor wire 320, and coil 314 can include conductor wire 322. In some embodiments, conductor wires 320 and 322 can be the same wire. In certain embodiments, conductor wires 320 and 322 can be different wires. Conductor wires 320 and 322 can be single-filar (as shown) or multi-filar (not shown). In embodiments, conductor wires 320 and 322 each have an insulating cover, electrically insulating conductor wire 320 from conductor wire 322 during use of the catheter. In an exemplary embodiment, the insulating cover can be polyurethane or polyimide. In some embodiments, conductor wires 320 and 322 can each comprise a single-filar wire that is symmetrically folded and wound around elongate shaft 302.

[0041] In some cases, the pitch between wires 320 and 322 (i.e., the distance between the midpoints of two adjacent wires) may be the same. In some cases, the pitch between wires 320 and 322 may be different. In some embodiments, wires 320 and 322 may be wound in the same direction (i.e., both clockwise or both counterclockwise). In some embodiments, wires 320 and 322 may be wound in opposite directions.

[0042] FIG. 3C is a partial cross-sectional view of an example of a distal end portion 300 of an ablation catheter, as indicated by arrow 3C in FIG. 3A. Due to the intersection between coils 308 and 314, the diameter of heating element 306 increases from d1 to d2, as shown in FIG. 3C. The difference between d1 and d2 is equal to or greater than the thickness of second heating coil 314. In some embodiments, the resulting diameter of heating element 306 can be from about 1 mm to about 4 mm. In exemplary embodiments, the resulting diameter of heating element 306 can be from about 2 mm to about 3 mm. In some embodiments, coils 308 and 314 are operably connected to an energy generator (e.g., energy generator 116 of FIG. 1) and configured to generate thermal energy in response to receiving an electrical signal (e.g., high-frequency current) from the energy generator.

[0043] In some embodiments, as shown in Figures 3A-3C, conductor wires 320 and 322 can be single-filar. In some embodiments, conductor wires 320 and 322 can be multi-filar (not shown). In an exemplary embodiment, conductor wire 320 can include one filer that is symmetrically folded and wound around elongate shaft 302, and conductor wire 322 can include one filer that is symmetrically folded and wound around elongate shaft 302. The number of filers in conductor wires 320 and 322 can be the same or different, and can be adjusted by including more or fewer filers in first heating coil 308 and / or second heating coil 314, depending on the desired diameter for a particular treatment site.

[0044] The crossover design allows for any desired diameter of the heating element 306 to be achieved by simply adjusting the number of fillers in each of the conductor wires. This allows for ease of manufacturing by eliminating the need to create different sized shafts (e.g., the elongated shaft 302 of FIGS. 3A-3B). Because veins can be tortuous due to chronic venous disease, it can be difficult for an operator to insert the distal end portion 300 of the ablation catheter into the target vein. If the catheter is too stiff, it can become increasingly difficult to position the heating element 306 on the distal end portion 300 at a specific treatment site. Increasing the flexibility of the catheter makes it easier for the distal end portion 300 to pass through tortuous veins and reach the target treatment site, and it can also shorten the procedure time. Additionally, the crossover design allows for an increase in the diameter of the catheter without increasing the diameter of the flexible elongated shaft 302.

[0045] Additionally, the conductor wires 320, 322 may be electrically isolated from one another and each controlled by a controller (e.g., controller 120 of FIG. 1) to generate heat individually or simultaneously. Thus, the physician and / or controller may have the flexibility to adjust the amount of heat used in the treatment depending on the patient's needs and the progress of the treatment.

[0046] In some embodiments, conductor wires 320 and 322 are electrically connected in series and receive the same current from an energy generator (e.g., energy generator 116 in FIG. 1 ) therethrough. In some embodiments, conductor wires 320 and 322 are electrically isolated from each other and each is individually addressable by an energy generator (e.g., energy generator 116 in FIG. 1 ). When wires 320 and 322 are electrically isolated from each other, a controller (e.g., controller 120 in FIG. 1 ) can be configured to selectively supply the current generated by the energy generator to one or both of the first and second conductor wires.

[0047] In some embodiments, the heating element 306 includes multiple coil segments spaced longitudinally from one another along the length of the distal end portion, each coil segment including a portion of a first heating coil and a portion of a second heating coil. In some embodiments, the heating coils 308 and 314 are resistive heating coils.

[0048] In some embodiments, the electrical signal generated by the energy generator (e.g., energy generator 116 of FIG. 1 ) can be a high-frequency alternating current, and the heating coils 308 and 314 are configured to deliver high-frequency ablation energy to the target tissue. In certain embodiments, one or more ground pads are used in conjunction with the heating coils 308 and 314 to deliver high-frequency ablation energy to the target blood vessel. In some embodiments, the heating coils 308 and 314 are configured to form a bipolar electrode to deliver high-frequency ablation energy to the target tissue or blood vessel. For example, the heating coils 308 and 314 include two or more coil segments, two of which form an electrode pair.

[0049] In some embodiments, an opening 326 may be formed along the length of the heating element 306, and the temperature sensor 328 may be disposed in the opening 326. Based on the temperature measured by the temperature sensor 328 or a signal indicative of the temperature, a controller (e.g., controller 120 of FIG. 1 ) may be configured to adjust the current to each of the conductor wires 320, 322 or selectively supply current to one or both of the conductor wires 320, 322. In some examples, if the measured temperature is too high, the controller may decrease the current generated by the energy generator. In certain examples, if the measured temperature is too high, the controller may supply the current generated by the energy generator to only one of the conductor wires 320, 322. In some examples, if the measured temperature is too low, the controller may increase the current generated by the energy generator. In certain examples, if the measured temperature is too low, the controller may supply the current generated by the energy generator to both of the conductor wires 320, 322.

[0050] 4 is a schematic diagram of a distal end portion of the ablation catheter of FIG. 1 in accordance with an embodiment of the present disclosure. As shown, distal end portion 400 includes a portion of an elongate shaft 402 terminating in a distal end 404 and a heating element 406 disposed near the distal end 404 of elongate shaft 402. Shaft 402 is sized and configured so that distal end 404 can be inserted into a target blood vessel.

[0051] The heating element 406 includes a first heating coil 408 having a plurality of first windings 410 wound in one direction 412 (indicated by the arrow around reference point A) and a second heating coil 414 having a plurality of second windings 416 wound in that direction 412 around the shaft 402 and in the same radial direction as the first heating coil 408. In some embodiments, the coils 408 and 414 are operably connected to an energy generator (e.g., energy generator 116 of FIG. 1 ) and configured to generate thermal energy when an electrical current supplied by the energy generator is delivered to the coils 408 and 414. In some embodiments, the coils 408 and 414 are electrically isolated from each other and individually addressable by the energy generator.

[0052] In some embodiments, each of the coils 408 and 414 can include a single-filar conductor wire. In some embodiments, each of the coils 408 and 414 can include a multi-filar conductor wire. In certain embodiments, the first and second heating coils 408, 414 can include a single-filar wire that is symmetrically folded and wound around the elongate shaft 402. In some embodiments, a controller (e.g., controller 120 of FIG. 1 ) can be configured to selectively supply electrical current generated by the energy generator to one or both of the first and second conductor wires.

[0053] In some embodiments, an opening 426 may be formed along the length of the heating element 406, and the temperature sensor 428 may be disposed in the opening 426. Based on the temperature measured by the temperature sensor 428 or a signal indicative of the temperature, a controller (e.g., controller 120 of FIG. 1 ) may be configured to adjust the respective currents to the conductor wires of the coils 408 and 414, or selectively supply current to one or both of the conductor wires of the coils 408 and 414. In some examples, if the measured temperature is too high, the controller may decrease the current generated by the energy generator. In certain examples, if the measured temperature is too high, the controller may supply the current generated by the energy generator to only one of the conductor wires of the coils 408 and 414. In some examples, if the measured temperature is too low, the controller may increase the current generated by the energy generator. In certain examples, if the measured temperature is too low, the controller may deliver the current generated by the energy generator to both of the conductor wires of the coils 408 and 414.

[0054] In some embodiments, the first and second heating coils 408 and 414 are resistive heating coils. In some embodiments, the electrical signal generated by the energy generator (e.g., energy generator 116 of FIG. 1) can be a high-frequency alternating current, and the first and second heating coils 408 and 414 are configured to deliver high-frequency ablation energy to the target tissue.

[0055] 5 is a schematic diagram of a distal tip section 500 of an ablation catheter, in accordance with an embodiment of the present disclosure. As shown, the distal tip section 500 includes a portion of an elongate shaft 502 terminating in a distal end 504, and a heating element 506 disposed near the distal end 504 of the elongate shaft 502. The shaft 502 is sized and configured so that the distal end 504 can be inserted into a target blood vessel.

[0056] As shown, the heating element 506 may include one or more coils 508a-d, each having multiple windings 510a-d wound around the shaft 502. Each of the multiple windings 510 defines a coil segment (e.g., 512a-d) and one or more segment gaps 514a-c between each adjacent coil segment 512a-d. The windings 510 may be wound around the shaft 502 using a winding machine to achieve a tighter and smoother coil 508 around the shaft 502. Using a winding machine may also help ensure the position of each coil segment (e.g., 512a-d).

[0057] The segmented design creates one or more segment gaps 514a-c, increasing the flexibility of the ablation catheter (e.g., ablation catheter 102 of FIG. 1 , ablation catheter 200 of FIG. 2A ) and minimizing potential undesired damage to the vessel wall during the procedure. Each of the coil segments 512a-d can be the same length. In some embodiments, the coil segments 512a-d can be wound by the same wire. In some embodiments, the coil segments 512a-d can be wound by different, separate wires. In some embodiments, when the coil segments 512a-d are wound by different wires, some or all of the coil segments 512a-d can be individually addressable by an energy generator (e.g., energy generator 116 of FIG. 1 ) and / or controllable by a controller (e.g., controller 120 of FIG. 1 ). For example, the coil segment 512a can be supplied with an ablation current, while the coil segment 512b is not supplied with an ablation current. By making some or all of the coil segments 512a-d individually addressable and controllable, electrical current can be selectively applied to each of the coil segments 512a-d to create electrical paths of different lengths and selectively vary the effective length of the thermal treatment.

[0058] In some embodiments, the coils 508a-d are operably connected to an energy generator (e.g., energy generator 116 of FIG. 1 ) and configured to generate thermal energy when current supplied by the energy generator is delivered to the coils 508a-d. In some embodiments, the coils 508a-d are individually addressable by the energy generator. In some embodiments, each of the coils 508a-d may include single-filar conductor wire. In some embodiments, each of the coils 508a-d may include multi-filar conductor wire. In some embodiments, a controller (e.g., controller 120 of FIG. 1 ) may be configured to selectively supply current generated by the energy generator to one or more of the conductor wires of the coils 508a-d.

[0059] In some embodiments, as shown, the plurality of windings 510a-d forming each of the coil segments 512a-d may include an opening 516a-d within each of the coil segments 512a-d. In certain embodiments, one or more temperature sensors (e.g., temperature sensors 328 or 428 in FIGS. 3A-B and 4) may be disposed in the openings 516a-d.

[0060] In some embodiments, the coils 508a-d are resistive heating coils. In some embodiments, the electrical signal generated by the energy generator (e.g., energy generator 116 of FIG. 1) can be a high-frequency alternating current, and the coils 508a-d are configured to deliver high-frequency ablation energy to the target tissue.

[0061] FIG. 6 is a schematic diagram of a distal end portion 600 of an ablation catheter, according to an embodiment of the present disclosure. As shown, the distal tip section 600 includes a portion of an elongate shaft 602 terminating in a distal end 604, and a heating element 606 disposed near the distal end 604 of the elongate shaft 602. The shaft 602 is sized and configured so that the distal end 604 can be inserted into a target blood vessel.

[0062] As shown, the heating element 606 can include one or more coils 608a-c, each having multiple windings 610a-c wound around the shaft 602. Each of the multiple windings 610 defines a coil segment 612a-c and one or more segment gaps 614a-b between adjacent coil segments 612a-d. The segmented design creates the one or more segment gaps 614a-b. In certain embodiments, the shaft 602 includes a flexible material, and the one or more segment gaps 614a-b enhance the flexibility of the heating element 606 and distal end portion 600 of the ablation catheter, for example, to minimize potential undesirable damage to the vessel wall during the procedure. Each of the coil segments 612a-c can be of different lengths. For example, the coil segment 612a has a length that is different from the length of the coil segment 612b. As an example, coil segment 612b has a length that is different from the length of coil segment 612c.

[0063] In some embodiments, the plurality of windings may form 2 to 8 coil segments, each of which may be about 1 cm to about 5 cm long. In some embodiments, the plurality of windings may form 3 to 6 coil segments, each of which may be about 1 cm to about 3 cm long. In an exemplary embodiment, for example, as shown in FIG. 5, the coil segments may be the same length, with the plurality of windings 510a-d including four coil segments 512a-d, each of which may be about 1.4 cm to about 2.3 cm long. In an exemplary embodiment, for example, as shown in FIG. 6, the coil segments may be different lengths, with the plurality of windings 610a-c including three coil segments 612a-c, each of which may be about 1 cm to about 4 cm long.

[0064] In some embodiments, the coils 608a-c are operably connected to an energy generator (e.g., energy generator 116 of FIG. 1 ) and configured to generate thermal energy when current supplied by the energy generator is delivered to the coils 608a-c. In some embodiments, the coils 608a-c are individually addressable by the energy generator. In some embodiments, each of the coils 608a-c may include single-filar conductor wire. In some embodiments, each of the coils 608a-c may include multi-filar conductor wire. In some embodiments, a controller (e.g., controller 120 of FIG. 1 ) may be configured to selectively supply current generated by the energy generator to one or more of the conductor wires of the coils 608a-c.

[0065] In some embodiments, as shown, the plurality of windings 610a-c forming each of the coil segments 612a-c can include openings 616a-c within each of the coil segments 612a-c. In some embodiments, one or more temperature sensors (e.g., temperature sensors 328 or 428 in FIGS. 3A-3B and 4) can be disposed in the openings 616a-c. In certain embodiments, the coils 608a-c are resistive heating coils. In some embodiments, the electrical signal generated by the energy generator (e.g., energy generator 116 in FIG. 1) can be a high-frequency alternating current, and the coils 608a-c are configured to deliver high-frequency ablation energy to the target tissue.

[0066] FIG. 7 is a schematic diagram of a distal end portion of an ablation catheter according to an embodiment of the present disclosure. As shown, the distal end portion 700 includes a portion of an elongate shaft 702 terminating in a distal end 704 and a heating element 706 disposed near the distal end 704 of the elongate shaft 702. The shaft 702 is sized and configured so that the distal end 704 can be inserted into a target blood vessel. In some examples, the distal end 704 has a diameter between 2 millimeters and 3 millimeters. In particular examples, the distal end 704 has a diameter between 1 millimeter and 5 millimeters. The heating element 706 can include one or more coil segments 712a-c. In certain embodiments, within certain diameter ranges, the distal end 704 and / or the heating element 706 are configured to be inserted into a blood vessel for ablation.

[0067] In some embodiments, the heating element 706 includes a first heating coil 708 having a plurality of first windings 710 wound in a first direction and a second heating coil 714 having a plurality of second windings 716 wound in a second direction. In some embodiments, the first direction can be different from the second direction, and the second windings 716 intersect with the first winding 710 within the length of each of the coils 712a-c. Due to the intersection between the coils 708 and 714, the diameter of each of the coil segments 712a-c of the heating element 706 increases from d1 to d2, as shown in FIG. 3B . The difference between d1 and d2 is equal to or greater than the thickness of the second heating coil 714.

[0068] In some embodiments, coils 708 and 714 are operably connected to an energy generator (e.g., energy generator 116 of FIG. 1) and configured to generate thermal energy in response to receiving an electrical signal (e.g., an electrical current) from the energy generator. In some embodiments, coils 708 are individually addressable by the energy generator.

[0069] In some embodiments, one or more of the coil segments 712 (e.g., coil segment 712c) may include an opening 718c therein. In some embodiments, one or more temperature sensors (e.g., temperature sensor 328 or 428 of FIGS. 3A-3B and 4) may be disposed in the opening 718c. In certain embodiments, the coils 712a-c are resistive heating coils. In some embodiments, the electrical signal generated by the energy generator (e.g., energy generator 116 of FIG. 1) may be a high-frequency alternating current, and the coils 712a-c are configured to deliver high-frequency ablation energy to the target tissue.

[0070] In some embodiments, the first and second plurality of windings 710, 716 are arranged to define a plurality of coil segments 712a-c, where adjacent coil segments (e.g., 712a-b or 712b-c) are longitudinally spaced apart from one another to define one or more segment gaps 720 between each adjacent coil segment along the length of the shaft 702. In particular embodiments, the heating element 706 is configured as a plurality of coil segments 712a-c longitudinally spaced apart from one another along the length of the heating element 706, where each coil segment 712a-c includes a portion of the first heating coil 708 and a portion of the second heating coil 714.

[0071] 8A-8C are schematic front, partial cross-sectional, and projected views, respectively, of a distal end portion of an ablation catheter, according to an embodiment of the present disclosure. As shown, distal end portion 800 includes a portion of an elongate shaft 802 terminating in a distal end 804, and a heating element 806 disposed near distal end 804 of elongate shaft 802. Shaft 802 is sized and configured such that distal end 804 can be inserted into a target blood vessel.

[0072] The heating element 806 includes a coil member 808 including a plurality of windings 810 wound around the shaft 802, with a plurality of openings 812a-d defined in the plurality of windings 810 along the length of the heating element 806. In some embodiments, the coil member 808 is operably connected to an energy generator (e.g., energy generator 116 of FIG. 1 ) and configured to generate thermal energy when an electrical current supplied by the energy generator is delivered to the coil member 808.

[0073] In some embodiments, the plurality of pressure sensors 814a-d are longitudinally spaced apart from one another along the shaft, each of the pressure sensors 814a-d being disposed on the shaft within a respective one of the openings 812a-d in the plurality of first windings, adjacent pressure sensors 814a-d being circumferentially offset from one another, and each pressure sensor 814a-d being configured to generate an output signal indicative of the pressure exerted by the surface of the target vessel on each pressure sensor 814a-d. In certain embodiments, two adjacent pressure sensors have a circumferential angular offset between one another. In some examples, adjacent pressure sensors 814a and 814b include an offset angle 815a, adjacent pressure sensors 814b and 814c include an offset angle 815b, adjacent pressure sensors 814c and 814d include an offset angle 815c, and adjacent pressure sensors 814d and 814a include an offset angle 815d.

[0074] In some embodiments, the coil member 808 further includes a plurality of second windings (not shown) wound around the shaft 802 in a second direction different from the first direction, with at least some of the plurality of second windings intersecting the plurality of first windings 810 at multiple spaced locations along the length of the heating element 806. In some embodiments, at least some of the openings 812a-d are defined between the plurality of first windings 810 and the plurality of second windings. In particular embodiments, the pressure sensors are circumferentially distributed along the shaft with equal offset angles (e.g., angles 815a-d) between two adjacent pressure sensors. For example, although not shown, in some embodiments, the plurality of pressure sensors includes three pressure sensors, with each of two adjacent pressure sensors of the three pressure sensors being circumferentially offset by 120 degrees from one another.

[0075] 8A-8C, the plurality of pressure sensors includes four pressure sensors 814a-d, where each two adjacent pressure sensors of the four pressure sensors 814a-d are circumferentially offset by 90 degrees from each other. Although not shown, in some embodiments, the plurality of pressure sensors includes six pressure sensors, where each two adjacent pressure sensors of the six pressure sensors are circumferentially offset by 60 degrees from each other. In some embodiments, the plurality of pressure sensors includes six pressure sensors, where each two adjacent pressure sensors of the six pressure sensors are circumferentially offset by 120 degrees from each other.

[0076] In some embodiments, the heating element 806 may further include a temperature sensor (not shown) disposed on the shaft 802. In some embodiments, the plurality of pressure sensors includes at least one selected from the group consisting of a piezoelectric pressure sensor, a capacitive pressure sensor (i.e., a sensor that measures a change in electrode impedance when the electrode contacts the venous wall), an inductive pressure sensor, a strain gauge pressure sensor, a fiber optic pressure sensor, and a potentiometric pressure sensor. As will be appreciated by one skilled in the art, any type of sensor that can indicate contact pressure between a sensor (e.g., sensors 814a-d) and the venous wall may be used herein.

[0077] During treatment, the heating element 806 is controlled to deliver ablation energy when an output signal indicative of pressure generated by one pressure sensor of the plurality of pressure sensors is greater than a predetermined threshold. In some embodiments, the heating element 806 is controlled to deliver ablation energy when an output signal indicative of pressure generated by two pressure sensors of the plurality of pressure sensors is greater than a predetermined threshold. In some embodiments, the heating element 806 is controlled to deliver ablation energy when an output signal indicative of pressure generated by two adjacent pressure sensors of the plurality of pressure sensors is greater than a predetermined threshold. In some embodiments, the heating element 806 is controlled to deliver ablation energy when an output signal indicative of pressure generated by all pressure sensors of the plurality of pressure sensors is greater than a predetermined threshold. The pressure sensors (e.g., 814a-d) are configured to monitor the pressure of the heating element 806 along the elongate shaft 802 during treatment so that an operator or a controller (e.g., controller 120 in FIG. 1 ) can estimate the degree of sealing of the vein wall (i.e., the degree of venous constriction) during treatment, more accurately determine the course of treatment, and adjust the treatment plan accordingly.

[0078] FIG. 9 is a schematic diagram of a distal end portion of an ablation catheter, in accordance with an embodiment of the present disclosure. As shown, the distal tip section 900 includes a portion of an elongate shaft 902 terminating in a distal end 904, and a heating element 906 disposed near the distal end 904 of the elongate shaft 902. The shaft 902 is sized and configured so that the distal end 904 can be inserted into a target blood vessel.

[0079] As shown, the heating element 906 may include one or more coils 908a-d, each having multiple windings 910a-d wound around the shaft 902. Each of the multiple windings 910 defines a coil segment 912a-d and one or more segment gaps 914a-c between adjacent coil segments 912a-d. The segmented design creates one or more segment gaps 914a-c, which increases the flexibility of the distal end portion 900 of the ablation catheter and minimizes potential undesirable damage to the vessel wall during the procedure. Each of the coil segments 912a-d may be the same length. In certain embodiments, some or all of the coil segments 912a-d are individually addressable and / or controllable. For example, coil segment 912a may be supplied with ablation current, while coil segment 912b is not.

[0080] In some embodiments, the coils 908a-d are operably connected to an energy generator (e.g., energy generator 116 of FIG. 1) and configured to generate thermal energy when an electrical current supplied by the energy generator is delivered to the coils 908a-d. In some embodiments, the coils 908a-d are individually addressable by the energy generator.

[0081] In some embodiments, each of the coils 908a-d may include a single-filar conductor wire. In some embodiments, each of the coils 908a-d may include a multi-filar conductor wire. In some embodiments, a controller (e.g., controller 120 of FIG. 1) may be configured to selectively supply the current generated by the energy generator to one or more of the conductor wires of the coils 908a-d.

[0082] In some embodiments, as shown, the plurality of windings 910a-d forming each of the coil segments 912a-d may include an opening 916a-d within each of the coil segments 912a-d. In certain embodiments, one or more temperature sensors (e.g., temperature sensors 328 or 428 in FIGS. 3A-3B and 4) may be disposed in the openings 916a-d.

[0083] In some embodiments, the coils 908a-d are resistive heating coils. In some embodiments, the electrical signal generated by the energy generator (e.g., energy generator 116 of FIG. 1) can be a high frequency alternating current, and the coils 908a-d are configured to deliver high frequency ablation energy to the target tissue or vessel.

[0084] In some embodiments, the heating element 906 may include multiple sets of coil segments 912a-d with corresponding multiple sets of pressure sensors 918a-d (pressure sensor 918d is not shown in FIG. 9 ), where a set of pressure sensors (e.g., a set of three pressure sensors, a set of four pressure sensors) spans the entire circumference of a set of coil segments (e.g., a set of three coil segments). In some examples, the sum of the offset angles between adjacent pressure sensors in a set of pressure sensors (e.g., four offset angles of 90 degrees each, a set of offset angles (90, 120, 90, 60)) equals 360 degrees. In some examples, the first set of pressure sensors and the second set of pressure sensors have the same adjacent offset angle pattern. In some examples, a set of coil segments is activated (e.g., current(s) is supplied) when an output signal indicative of pressure generated by at least one pressure sensor in the set of pressure sensors is greater than a predetermined threshold. In some examples, a set of coil segments is deactivated (e.g., no current or currents are supplied) if none of the output signals indicative of pressure generated by the set of pressure sensors is greater than a predetermined threshold.

[0085] In an exemplary embodiment, at least one pressure sensor of the plurality of pressure sensors 918a-d is disposed in an opening (e.g., opening 916a, 916b, 916c, or 916d) in a coil segment (e.g., coil segment 912a, 912b, 912c, or 912d). In some embodiments, the heating element may further include a temperature sensor (e.g., temperature sensor 328 or 428 of FIGS. 3A-B and 4) disposed in one of the segment gaps 914a-c. The temperature sensor may be longitudinally spaced from one of the plurality of pressure sensors 918a-d and circumferentially offset from one of the plurality of pressure sensors 918a-d.

[0086] FIG. 10 is a schematic diagram of a distal end portion of an ablation catheter according to an embodiment of the present disclosure. As shown, the distal tip portion 1000 includes a portion of an elongate shaft 1002 terminating in a distal end 1004, and a heating element 1006 disposed near the distal end 1004 of the elongate shaft 1002. The shaft 1002 is sized and configured so that the distal end 1004 can be inserted into a target blood vessel.

[0087] As shown, the heating element 1006 may include one or more coils 1008a-c, each having multiple windings 1010a-c wound around the shaft 1002. Each of the multiple windings 1010 defines a coil segment 1012a-c and one or more segment gaps 1014a-b between adjacent coil segments 1012a-c. The segmented design creates the one or more segment gaps 1014a-b. In certain embodiments, the shaft 1002 includes a flexible material, and the one or more segment gaps 1014a-b enhance the flexibility of the heating element 1006 and distal end portion 1000 of the ablation catheter, for example, to minimize potential undesirable damage to the vessel wall during a procedure. Each of the coil segments 1012a-c may be of different lengths. For example, the coil segment 1012a has a length that is different from the length of the coil segment 1012b. As an example, coil segment 1012b has a length that is different from the length of coil segment 1012c.

[0088] In some embodiments, the coils 1008a-c are operably connected to an energy generator (e.g., energy generator 116 of FIG. 1 ) and configured to generate thermal energy when current supplied by the energy generator is delivered to the coils 1008a-c. In some embodiments, the coils 1008a-c are individually addressable by the energy generator. In some embodiments, each of the coils 1008a-c may include single-filar conductor wire. In some embodiments, each of the coils 1008a-c may include multi-filar conductor wire. In some embodiments, a controller (e.g., controller 120 of FIG. 1 ) may be configured to selectively supply current generated by the energy generator to one or more of the conductor wires of the coils 1008a-c.

[0089] In some embodiments, as shown, the plurality of windings 1010a-c forming each of the coil segments 1012a-c can include openings 1016a-c within each of the coil segments 1012a-c. In certain embodiments, the coils 1008a-c are resistive heating coils. In some embodiments, the electrical signal generated by the energy generator (e.g., energy generator 116 of FIG. 1) can be a high-frequency alternating current, and the coils 1008a-c are configured to deliver high-frequency ablation energy to the target tissue or vessel.

[0090] In certain embodiments, the heating element 1006 may include multiple sets of coil segments 1012a-c with corresponding multiple sets of pressure sensors 1018a-c, where a set of pressure sensors (e.g., a set of three pressure sensors) is fully circumferentially covered by a set of coil segments (e.g., a set of three coil segments). In some examples, the sum of the offset angles between adjacent pressure sensors in a set of pressure sensors (e.g., three offset angles of 120 degrees each, a set of offset angles of (180, 120, 60)) equals 360 degrees. In some examples, a set of coil segments is activated (e.g., current(s) is / are supplied) when an output signal indicative of pressure generated by at least one pressure sensor in the set of pressure sensors is greater than a predetermined threshold. In some examples, a set of coil segments is deactivated (e.g., current(s) is / are not supplied) when none of the output signals indicative of pressure generated by the set of pressure sensors is greater than a predetermined threshold.

[0091] In an exemplary embodiment, at least one pressure sensor of the plurality of pressure sensors 1018a-c is disposed in an opening (e.g., opening 1016a, 1016b, or 1016c) in a coil segment (e.g., coil segment 1012a, 1012b, or 1012c). In some embodiments, the heating element 1006 may further include a temperature sensor (e.g., temperature sensor 328 or 428 of FIGS. 3A-3B and 4) disposed in one of the segment gaps 1014a-b. The temperature sensor may be longitudinally spaced from one of the plurality of pressure sensors 1018a-c and circumferentially offset from one of the plurality of pressure sensors 1018a-c. In some embodiments, one or more temperature sensors (e.g., temperature sensor 328 or 428 of FIGS. 3A-3B and 4) may be disposed in the openings 1016a-c.

[0092] In some embodiments (e.g., as shown in FIG. 7 ), a heating element (e.g., heating element 114 of FIG. 1 ) may include first and second plurality of windings arranged to define multiple coil segments, with at least some of the second plurality of windings intersecting the first windings along the length of the heating element, and adjacent coil segments spaced longitudinally from one another to define one or more segment gaps between each adjacent coil segment along the length of the shaft. In exemplary embodiments, one or more openings are formed in one or more of the multiple coil segments, and at least one pressure sensor of the multiple pressure sensors is disposed in the opening within the coil segment. In some embodiments, the heating element may further include a temperature sensor disposed in one of the one or more segment gaps. The temperature sensor may be longitudinally spaced from one of the multiple pressure sensors and circumferentially offset from one of the multiple pressure sensors.

[0093] 11A-11B are schematic illustrations of a portion of an ablation catheter for use within a target vessel of a patient for the treatment of varicose veins, according to an embodiment of the present disclosure. In some embodiments, during an intravenous thermal ablation procedure, an introducer sheath may be placed into a patient's target vein using ultrasound guidance and standard vascular techniques. An ablation catheter (e.g., ablation catheter 102 in FIG. 1 ) may then be inserted through the introducer sheath into the target vein. In some circumstances, under ultrasound guidance, an infiltration anesthetic solution or saline may be injected into the target vein segment to act as a heat sink to protect the tissue from thermal damage and to improve thermal conductivity between the wall of the target vein and the ablation catheter.

[0094] As shown in Figure 11A, a distal end portion 1100 of an ablation catheter (e.g., ablation catheter 102 of Figure 1) is positioned within a target blood vessel 1102a. The ablation catheter may be introduced and positioned through an introducer sheath using ultrasound guidance. As will be appreciated by those skilled in the art, any standard vascular technique may be used here to introduce and position the distal end portion 1100 of the ablation catheter within the target vein segment. The distal end portion 1100 may include a heating element 1106 having heating coils 1108 and 1114.

[0095] In some embodiments, during treatment, an electric current can be applied to the heating coils 1108 and 1114 by a generator (e.g., energy generator 116 of FIG. 1 ). The generator can include a radiofrequency generator that generates a radiofrequency electric current to heat the heating coils 1108 and 1114. In some implementations, the ablation catheter can include a temperature sensor disposed along the length of the catheter shaft, and power supply to the coils can be automatically adjusted by a controller (e.g., controller 120 of FIG. 1 ) based on the temperature or a signal indicative of the temperature measured by the temperature sensor. In some embodiments, power supply to the heating coils 1108 and 1114 can heat the heating coils 1108 and 1114 to about 80° C. to about 140° C. to treat varicose veins. In some embodiments, power supply to the heating coils 1108 and 1114 can heat the heating coils 1108 and 1114 to about 100° C. to about 130° C. to treat varicose veins. In some embodiments, powering the heating coils 1108 and 1114 can heat the heating coils 1108 and 1114 to approximately 120° C. to treat varicose veins.

[0096] The segment of the target vessel 1102a being treated adjacent to the heating coils 1108 and 1114 will close (e.g., contract, reduce in diameter) as the coils are heated, as shown as 1102b in FIG. 11B. External pressure can be applied as needed during treatment. After a particular section has been treated (i.e., a section of the vein has closed), the catheter can be moved toward the venous access, as shown by arrow 1116, and this process can be repeated until the entire vein is closed. The catheter and introducer sheath can then be removed after treatment has been performed. In some use cases, the diameter of the heating element 1106 is smaller than the diameter of the vessel 1102a, allowing the heating element 1106 to be moved closer to the vessel wall during treatment.

[0097] In some embodiments, a device for treating varicose veins may include an energy generator configured to generate an electric current, a controller operably connected to the energy generator and controlling the generation of the electric current, and a catheter connected to the energy generator. The catheter may include a handle, an elongate shaft connected to the handle having a proximal end and a distal end portion terminating at a distal end, the elongate shaft being sized and configured so that the distal end can be inserted into a target blood vessel, and a heating element disposed near the distal end of the elongate shaft, the heating element including a first heating coil having a plurality of first windings wound in a first direction around the shaft and a second heating coil having a plurality of second windings wound in the first direction around the shaft in the same radial direction as the first heating coil, the first and second heating coils each operably connected to the energy generator and configured to generate thermal energy when an electric current supplied by the energy generator is delivered to the first and second heating coils, the first and second heating coils being electrically isolated from each other and individually addressable by the energy generator. In some embodiments, the first and second heating coils can each comprise a single-filar conductor wire. In some embodiments, the first and second heating coils can each comprise a multi-filar conductor wire. In some embodiments, the first and second heating coils can be resistive heating coils, the electrical signal is a high frequency alternating current, and the first and second heating coils are configured to deliver high frequency ablation energy to the target tissue.

[0098] As used herein, the terms "about" and "approximately" may be used interchangeably with respect to measurements (e.g., dimensions, characteristics, attributes, components, etc.) and ranges thereof, particularly with respect to tangible (e.g., products, inventory, etc.) and / or intangible (e.g., data, electronic representations of currency, accounts, information, proportions of things (e.g., percentages, fractions), calculations, data models, dynamic system models, algorithms, parameters, etc.) measurements. The terms "about" and "approximately" include the stated measurement and measurements that are reasonably close to the stated measurement, including slight variations that are understood and readily discernible by a person of ordinary skill in the relevant art as resulting from measurement error, variations in the calibration of measuring or manufacturing equipment, human error in reading and / or setting measurements, adjustments to optimize performance or structural parameters taking into account other measurements (e.g., measurements relative to other objects), specific implementation scenarios, human, computing device, or machine manipulation, setting, imprecise adjustment and / or manipulation of measurements, system tolerances, control loops, machine learning, predictable variations (e.g., statistically negligible variations, chaotic variations, system and / or model instability, etc.), preferences, and / or the like.

[0099] Although an example method may be represented by one or more drawings (e.g., flow diagrams, communication flows, etc.), the drawings should not be construed as implying a requirement for the various steps disclosed herein, or a particular order among the steps. However, certain embodiments may require certain steps and / or a particular order among certain steps (e.g., the performance of some steps may depend on the results of previous steps), as may be explicitly described herein and / or understood from the nature of the steps themselves. Furthermore, a "set," "subset," or "group" of items (e.g., inputs, algorithms, data values, etc.) may include one or more items, and similarly, a subset or subgroup of items may include one or more items. "Plurality" means two or more.

[0100] Various modifications and additions can be made to the described exemplary embodiments without departing from the scope of the present invention. For example, while the above-described embodiments refer to particular features, the scope of the present invention also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of the present invention is intended to embrace all such alternatives, modifications, and variations that fall within the scope of the claims, together with all equivalents thereof.

Claims

1. 1. A device for treating varicose veins, comprising: a long catheter, the long catheter comprising: an elongate shaft having a proximal end and a distal end defining a longitudinal axis, the distal end sized and configured for insertion into a target vessel; a heating element disposed near the distal end of the elongate shaft, the heating element comprising a coil member having a plurality of first windings wound in a first direction around the shaft, the plurality of first windings defining a plurality of openings along a length of the heating element; a plurality of pressure sensors arranged longitudinally spaced apart from one another along the shaft, each of the plurality of pressure sensors being positioned on the shaft within a respective one of the plurality of openings in the plurality of first windings, adjacent pressure sensors being circumferentially offset from one another, and each pressure sensor being configured to generate an output signal indicative of the pressure exerted on each pressure sensor by the surface of the target blood vessel.

2. 2. The device of claim 1, wherein the coil member further comprises a plurality of second windings wound around the shaft in a second direction different from the first direction, at least some of the plurality of second windings intersecting the plurality of first windings at a plurality of spaced apart locations along the length of the heating element, and at least some of the plurality of openings being defined between the plurality of first windings and the plurality of second windings.

3. 2. The device of claim 1, wherein the plurality of pressure sensors includes N pressure sensors, and two adjacent pressure sensors of the plurality of pressure sensors are circumferentially offset from each other by an offset degree associated with N.

4. 2. The device of claim 1, wherein the plurality of pressure sensors includes a first pair of pressure sensors and a second pair of sensors, the first pair of pressure sensors including a first pressure sensor and a second pressure sensor adjacent to the first pressure sensor, the second pressure sensor being circumferentially offset by a first offset angle relative to the first pressure sensor, and the second pair of sensors including a third pressure sensor and a fourth pressure sensor adjacent to the third pressure sensor, the fourth pressure sensor being circumferentially offset by a second offset angle relative to the third pressure sensor, the second offset angle being equal to the first offset angle.

5. 2. The device of claim 1, wherein the plurality of first windings and the plurality of second windings are arranged to define a plurality of coil segments, adjacent coil segments being longitudinally spaced from one another to define one or more segment gaps between each adjacent coil segment along the length of the shaft, and the device further comprises a temperature sensor, the temperature sensor being disposed in one of the one or more segment gaps, and at least one pressure sensor of the plurality of pressure sensors being disposed in an opening in a coil segment.

6. The device of claim 1 , wherein the plurality of pressure sensors includes six pressure sensors.

7. The device of claim 6 , wherein two adjacent pressure sensors of the plurality of pressure sensors are circumferentially offset by 60 degrees from each other.

8. The device of claim 6 , wherein two adjacent pressure sensors of the plurality of pressure sensors are circumferentially offset by 120 degrees from each other.

9. 9. The device of claim 1, wherein the plurality of pressure sensors includes at least one selected from the group consisting of a piezoelectric pressure sensor, a capacitive pressure sensor, an inductive pressure sensor, a strain gauge pressure sensor, and a potentiometric pressure sensor.

10. 9. The device of claim 1, wherein the heating element is controlled to deliver ablation energy when an output signal indicative of pressure generated by one of the plurality of pressure sensors is greater than a predetermined threshold.

11. 1. A device for treating varicose veins, comprising: an energy generator configured to generate an electrical signal; a controller operatively connected to the energy generator and controlling generation of the electrical signal; an elongated catheter connected to the energy generator, the elongated catheter comprising: an elongate shaft having a proximal end and a distal end defining a longitudinal axis, the distal end sized and configured for insertion into a target vessel; a heating element disposed near the distal end of the elongate shaft, a first coil member comprising a first plurality of windings wound about the shaft, wherein one or more first openings in the first plurality of windings are defined along a length of the first coil member; the heating element including a second coil member having a second plurality of windings wound about the shaft, wherein one or more second openings in the second plurality of windings are defined along a length of the second coil member; a plurality of pressure sensors disposed longitudinally spaced apart from one another along the shaft, each pressure sensor of the plurality of pressure sensors disposed on the shaft within a respective opening of the first opening of the first plurality of windings or the second opening of the second plurality of windings, at least two adjacent pressure sensors being circumferentially offset from one another, each pressure sensor configured to generate an output signal indicative of pressure exerted by a surface of a target blood vessel on each pressure sensor; the first and second coil members are each operably connected to the energy generator and configured to generate thermal energy when the electrical signal generated by the energy generator is delivered to the first and second coil members.

12. 12. The device of claim 11, wherein the heating element further includes a third coil member having a third plurality of windings wound around the shaft, wherein one or more third openings in the third plurality of windings are defined along a length of the third coil member, and wherein one or more of the plurality of pressure sensors are disposed on the shaft within one or more of the third openings.

13. 12. The device of claim 11, wherein the controller is configured to adjust the current generated by the energy generator based on the output signal generated by each pressure sensor of the plurality of pressure sensors indicative of the pressure applied to each pressure sensor.

14. 14. The device of claim 11, wherein the controller is configured to control the current generated by the energy generator to be selectively delivered to one or both of the first coil member and the second coil member.

15. 14. The device of claim 11, further comprising a temperature sensor disposed on the shaft within one of the first opening or the second opening, the temperature sensor being longitudinally spaced along the shaft from one of the plurality of pressure sensors.

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