Duct construction to eliminate static electricity and noise

Abstract

The present invention relates to a device comprising a catheter having a flexible outer sheath and a flexible irrigation tube. The flexible outer sheath defines a first lumen. The flexible irrigation tube is positioned within the first lumen and comprises an inner layer and an outer coating. The inner layer is formed of a synthetic polymer compound and has a uniform cross-section and a hollow interior defining a second lumen. The outer coating is disposed around the inner layer. The outer coating is formed of a polymer compound and comprises a first isomer and a second isomer. The first isomer is configured to carry a positive charge, and the second isomer is configured to carry a negative charge.

Description

Background Art

[0001] Arrhythmias, such as atrial fibrillation, occur when an area of ​​cardiac tissue conducts electrical signals abnormally. Procedures for treating arrhythmias include surgically interrupting the conduction pathways for such signals. By applying energy (e.g., radiofrequency (RF) energy) to selectively ablate cardiac tissue, it is possible to stop or alter the propagation of unwanted electrical signals from one part of the heart to another. The ablation process can provide a block to the unwanted electrical pathway by forming an electrically insulating lesion or scar tissue that effectively blocks the communication of abnormal electrical signals across tissue.

[0002] In some procedures, a catheter with one or more RF electrodes may be used to provide ablation within the cardiovascular system. The catheter may be inserted into a major vein or artery (e.g., the femoral artery) and then advanced to position the electrode within the heart or in a cardiovascular structure adjacent to the heart (e.g., the pulmonary vein). One or more electrodes may be placed in contact with cardiac tissue or other vascular tissue and then activated with RF energy, thereby ablating the contacted tissue. In some cases, the electrodes may be bipolar. In some other cases, a monopolar electrode may be used in conjunction with a ground pad or other reference electrode in contact with the patient. Irrigation may be used to absorb heat from the ablation component of the ablation catheter; and to prevent the formation of blood clots near the ablation site.

[0003] Examples of ablation catheters are described in the following: U.S. Publication 2013 / 0030426, published on January 31, 2013, entitled “Integrated Ablation System using Catheter with Multiple Irrigation Lumens,” the disclosure of which is incorporated herein by reference in its entirety; U.S. Publication 2017 / 0312022, published on November 2, 2017, entitled “Irrigated Balloon Catheter with Flexible Circuit Electrode Assembly,” the disclosure of which is incorporated herein by reference in its entirety; U.S. Publication 2018 / 0071017, published on March 15, 2018, entitled “Ablation Catheter with a Flexible Printed Circuit Board,” the disclosure of which is incorporated herein by reference in its entirety; and U.S. Publication 2018 / 0071017, published on March 1, 2018, entitled “Catheterwith Bipole Electrode Spacer and Related and U.S. Patent No. 9,801,585, entitled “Electrocardiogram Noise Reduction,” published on October 31, 2017, the disclosure of which is incorporated herein by reference in its entirety.

[0004] Some catheter ablation procedures may be performed after using electrophysiological (EP) mapping to identify tissue areas that should be targeted for ablation. Such EP mapping may include the use of sensing electrodes on a catheter (e.g., the same catheter used to perform the ablation or a dedicated mapping catheter). Such sensing electrodes can monitor electrical signals emanating from conductive endocardial tissue to precisely locate the location of abnormal conductive tissue sites that cause arrhythmias. An example of an EP mapping system is described in U.S. Patent No. 5,738,096, entitled "Cardiac Electromechanics," issued on April 14, 1998, the disclosure of which is incorporated herein by reference in its entirety. Examples of EP mapping catheters are described in the following documents: U.S. Patent 9,907,480, entitled “Catheter Spine Assembly with Closely-Spaced Bipole Microelectrodes,” published on March 6, 2018, the disclosure of which is incorporated herein by reference in its entirety; U.S. Patent 10,130,422, entitled “Catheter with Soft Distal Tip for Mapping and Ablating Tubular Region,” published on November 20, 2018, the disclosure of which is incorporated herein by reference in its entirety; and U.S. Publication 2018 / 0056038, entitled “Catheter with Bipole Electrode Spacer and Related Methods,” published on March 1, 2018, the disclosure of which is incorporated herein by reference in its entirety.

[0005] When using an ablation catheter, it may be desirable to ensure that one or more electrodes of the ablation catheter are in sufficient contact with the target tissue. For example, it may be desirable to ensure that the one or more electrodes are in contact with the target tissue with sufficient force to effectively apply RF ablation energy to the tissue; but without applying a degree of force that may tend to undesirably damage the tissue. To this end, it may be desirable to include one or more force sensors or pressure sensors for detecting sufficient contact between the one or more electrodes of the ablation catheter and the target tissue.

[0006] In addition to using force sensing or EP mapping, some catheter ablation procedures may also be performed using an image-guided surgery (IGS) system. An IGS system may enable a physician to visually track the position of a catheter within a patient relative to an image of the patient's anatomy in real time. Some systems may provide a combination of EP mapping and IGS functionality, including the 100-gauge 1000 system from Biosense Webster, Inc., Irvine, California. Examples of catheters configured for use with the IGS system are disclosed in U.S. Patent No. 9,480,416, entitled “Signal Transmission Using Catheter Braid Wires,” issued on November 1, 2016, the disclosure of which is incorporated herein by reference in its entirety, and various other references cited herein.

[0007] While several catheter systems and methods have been made and used, it is believed that no one prior to the inventors has made or used the invention described, shown, and claimed herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The following drawings and detailed description are intended to be illustrative only and are not intended to limit the scope of the invention as contemplated by the inventors.

[0009] Figure 1 A schematic diagram showing a medical procedure for inserting a catheter of a catheter assembly into a patient;

[0010] Figure 2 Shows Figure 1 A perspective view of a distal portion of a catheter of , with additional components shown in schematic form;

[0011] Figure 3 Shows Figure 1 a perspective view of a distal portion of a catheter of wherein the outer sheath is omitted to show the internal components;

[0012] Figure 4 Shows Figure 1 an exploded perspective view of a distal portion of a catheter;

[0013] Figure 5 shows a longitudinal cross-sectional view of a prior art irrigation tube in use and having an exemplary initial static charge buildup adjacent a irrigation pump roller, wherein the irrigation tube includes a single layer of material that collects the static charge buildup;

[0014] Figure 6 Shows that it can be Figure 1 A longitudinal cross-sectional view of a first example of an irrigation tube for use with a variation of a catheter of the invention, wherein the first embodiment of the irrigation tube comprises a plurality of material layers;

[0015] Figure 7 Shown along Figure 6 The center line 7-7 is intercepted Figure 6 A cross-sectional view of a flushing pipe;

[0016] Fig. 8A Shows Figure 6a longitudinal cross-sectional view of a flush tube of FIG. 1 in use and having an exemplary initial static charge accumulation adjacent a flush pump roller, wherein the flush tube comprises a plurality of material layers;

[0017] Figure 8B Shows Fig. 8A A flushing pipe showing the buildup of static charge absorbed by multiple layers of material;

[0018] Fig. 9 Shows that it can be Figure 1 A longitudinal cross-sectional view of a second example of an irrigation tube for use with a variation of a catheter of the invention, wherein the second embodiment of the irrigation tube comprises a plurality of material layers; and

[0019] Fig.10 Shown along Fig. 9 The center line 10-10 is intercepted Fig. 9 Cross-section of the flushing pipe. DETAILED DESCRIPTION

[0020] The following description of certain examples of the present invention should not be used to limit the scope of the present invention. The accompanying drawings (not necessarily drawn to scale) illustrate selected embodiments and are not intended to limit the scope of the present invention. The detailed description illustrates the principle of the present invention by way of example and not in a limiting manner. According to the following description shown by way of example, other examples, features, aspects, embodiments and advantages of the present invention will be apparent to those skilled in the art, and a best mode is contemplated for implementing the present invention. As will be appreciated, the present invention can have other different or equivalent aspects, all of which do not depart from the present invention. Therefore, the drawings and description should be considered to be illustrative and not restrictive in nature.

[0021] Any one or more of the teachings, expressions, patterns, examples, etc. described herein may be combined with any one or more of the other teachings, expressions, patterns, examples, etc. described herein. Therefore, the following teachings, expressions, patterns, examples, etc. should not be considered separate from each other. Various suitable ways in which the teachings herein can be combined will be apparent to those skilled in the art with reference to the teachings herein. Such modifications and variations are intended to be included within the scope of the claims.

[0022] As used herein, the term "about" or "approximately" for any numerical value or range indicates a suitable dimensional tolerance that allows a collection of parts or elements to achieve its intended purpose as described herein. More specifically, "about" or "approximately" may refer to a range of ±20% of the value of the recited value, for example, "about 90%" may refer to a range of values ​​from 71% to 99%. In addition, as used herein, the terms "patient," "host," "user," and "subject" refer to any human or animal subject, and are not intended to limit systems or methods to human use, but the use of the subject invention in human patients represents a preferred embodiment.

[0023] I. Overview of Exemplary Ablation Catheter Systems

[0024] Figure 1 An exemplary medical procedure and associated components of a cardiac ablation catheter system that can be used to provide a cardiac ablation procedure as mentioned above are shown. Specifically, Figure 1 A physician (PH) is shown holding the handle (110) of the catheter assembly (100), wherein the catheter (120) of the catheter assembly (100) (in Figures 2 to 4 Shown but not in Figure 1 An end effector (140) of a catheter assembly (100) is disposed within a patient (PA) to ablate tissue in or near a heart (H) of the patient (PA). The catheter assembly (100) includes a handle (110), a catheter (120) extending distally from the handle (110), an end effector (140) located at a distal end of the catheter (120), and a user input feature (190) located on the handle.

[0025] As will be described in more detail below, the end effector (140) includes various components configured to deliver RF energy to a target tissue site, provide EP mapping functionality, track external forces applied to the end effector (140), track the position of the end effector (140), and disperse irrigation fluid. As will be described in more detail below, the user input feature (190) is configured to move the end effector (140) and the distal portion of the catheter (120) away from a central longitudinal axis (LL) defined by the proximal portion of the catheter (120) ( Figures 3 to 5 )deflection.

[0026] like Figure 2As shown, the catheter (120) includes an elongated flexible sheath (122), wherein an end effector (140) is disposed at the distal end of the sheath (122). The end effector (140) and the various components contained in the sheath (122) will be described in more detail below. The catheter assembly (100) is coupled to the guidance and drive system (10) via a cable (30). The catheter assembly (100) is also coupled to a fluid source (42) via a fluid conduit (40). A set of field generators (20) are positioned below the patient (PA) and are coupled to the guidance and drive system (10) via another cable (22). The field generators (20) are only optional.

[0027] The guide and drive system (10) of the present example includes a console (12) and a display (18), such as a digital display. The console (12) includes a first driver module (14) and a second driver module (16). The first driver module (14) is coupled to the catheter assembly (100) via a cable (30). In some variations, the first driver module (14) can be operated to receive EP mapping signals obtained via a microelectrode (138) of an end effector (140), as described in more detail below. The console (12) includes a processor (not shown) that processes such EP mapping signals to provide EP mapping as known in the art.

[0028] The first driver module (14) of the present example can also be operated to provide RF power (as will be described in more detail below) to the distal end member (142) of the end effector (140), thereby ablating tissue. The second driver module (16) is coupled to the field generator (20) via a cable (22). The second driver module (16) can be operated to activate the field generator (20) to generate an alternating magnetic field around the heart (H) of the patient (PA). For example, the field generator (20) may include a coil that generates an alternating magnetic field in a predetermined working volume that accommodates the heart (H).

[0029] The first driver module (14) can also be operated to receive a position indication signal from a navigation sensor assembly (150) in the end effector (140). In this type of formula, the processor of the console (12) can also be operated to process the position indication signal from the navigation sensor assembly (150) to determine the position of the end effector (140) in the patient (PA). As will be described in more detail below, the navigation sensor assembly (150) includes a pair of coils on a corresponding panel (151) that can be operated to generate a signal indicating the position and orientation of the end effector (140) in the patient (PA). The coil is configured to generate an electrical signal in response to the presence of an alternating electromagnetic field generated by the field generator (20). Other components and technologies that can be used to generate real-time position data associated with the end effector (140) may include wireless triangulation, acoustic tracking, optical tracking, inertial tracking, etc. Alternatively, the end effector (140) may not have a navigation sensor assembly (150).

[0030] The display (18) is coupled to the processor of the console (12) and is operable to present an image of the patient's anatomical structure. Such images may be based on a set of images obtained before or during surgery (e.g., CT or MRI scans, 3D mapping maps, etc.). The view of the patient's anatomical structure provided by the display (18) may also be dynamically changed based on a signal from the navigation sensor assembly (150) of the end effector (140). For example, when the end effector (140) of the catheter (120) moves within the patient (PA), the corresponding position data from the navigation sensor assembly (150) may cause the processor of the console (12) to update the patient's anatomical structure view in real time in the display (18) to depict the area of ​​the patient's anatomical structure around the end effector (140) as the end effector (140) moves within the patient (PA). In addition, the processor of the console (12) may drive the display (18) to display the location of abnormal conductive tissue sites detected via electrophysiological (EP) mapping using the end effector (140) or detected in other ways (e.g., using a dedicated EP mapping catheter, etc.). The processor of the console (12) may also drive the display (18) to superimpose the current position of the end effector (140) on the image of the patient's anatomy, such as by superimposing an illuminated dot, crosshairs, a graphical representation of the end effector (140), or some other form of visual indication.

[0031] The fluid source (42) of the present example comprises a bag containing saline or some other suitable flushing fluid. The conduit (40) comprises a flexible tube that is also coupled to a pump (44) that is operable to selectively drive fluid from the fluid source (42) to the catheter assembly (100). As described in more detail below, such flushing fluid may be discharged through an opening (158) of the distal tip member (142) of the end effector (140). Such flushing may be provided in any suitable manner that will be apparent to one skilled in the art in view of the teachings herein.

[0032] II. Exemplary End Effectors of Catheter Assemblies

[0033] Figures 2 to 4 Exemplary components of the end effector (140) and other components of the distal portion of the catheter (120) are shown in more detail. The end effector (140) includes a distal end member (142), a distal end base (144), a distal circuit disk (146), a strain gauge assembly (148), a navigation sensor assembly (150), a distal spacer stack (152), and a pair of proximal spacers (154). The distal end member (142), the distal end base (144), the distal circuit disk (146), the strain gauge assembly (148), the navigation sensor assembly (150), the distal spacer stack (152), and the proximal spacer (154) are coaxially aligned with each other and stacked longitudinally so that these components (144-154) define a stacked circuit. A pair of push-pull cables (160, 170) and an irrigation tube (180) extend along the length of the catheter (120) to reach the end effector (140). Each of the aforementioned components will be described in greater detail below.A flexible sheath (122) surrounds all of the aforementioned components except for the distal tip member (142).

[0034] like Figure 3 to Figure 4 As shown, the distal end member (142) of this example is conductive and includes a cylindrical body (156) having a dome-shaped end. A plurality of openings (158) are formed through the cylindrical body (156) and communicate with the hollow interior of the distal end member (142). Therefore, the opening (158) allows the irrigation fluid to be transmitted from the interior of the distal end member (142) through the cylindrical body (156). The cylindrical body (156) and the dome end can also be operated to apply RF power to the tissue, thereby ablating the tissue. Such RF power can be transmitted from the first driver module (14) to the most proximal spacer (154) via the cable (30). The distal end member (142) may also include one or more thermocouples configured to provide temperature sensing capabilities.

[0035] like Figure 3 to Figure 4As shown, the distal end member (142) of the present example further includes one or more EP mapping microelectrodes (138) mounted to the cylindrical body (156). The EP mapping microelectrodes (138) are configured to pick up electrical potentials from tissue in contact with the EP mapping microelectrodes (138). According to the teachings of various references cited herein, the first driver module (14) can process the EP mapping signals and provide corresponding feedback to the physician (PH) indicating the location of abnormal electrical activity.

[0036] The strain gauge assembly (148) is positioned proximal to the distal circuit disk (146) and is configured to sense external forces impacting the distal tip member (142). When the distal tip (142) encounters external forces (e.g., when the distal tip (142) is pressed against tissue), those external forces are transmitted from the distal tip (142) to the distal tip base (144), to the distal circuit disk (146), and to the strain gauge assembly (148), so that the strain gauges can generate appropriate signals corresponding to the magnitude and direction of the external forces.

[0037] The navigation sensor assembly (150) can generate a signal that is substantially accurate in indicating the position and orientation of the end effector (140) in three-dimensional space. The signal from the navigation sensor assembly (150) can be transmitted through a through hole or other structure in a layer located proximal to the strain navigation sensor assembly (150), and finally reaches the first driver module (14) of the console (12) via the cable (30).

[0038] As mentioned above and Figure 1 to Figure 2 As shown in , the cable (30) couples the catheter assembly (100) to the drive system (10). Figure 4 As shown, wire (32) of cable (30) extends along the length of catheter (120) to reach the most proximal proximal septum (154).

[0039] As also described above, the catheter assembly (100) is configured to enable irrigation fluid to be delivered from the fluid source (42) to the catheter (120) via the fluid conduit (40), thereby providing for discharge of the irrigation fluid through the opening (158) of the distal tip member (142). In this example, the fluid path for the irrigation fluid includes an irrigation tube (180) that is disposed at Figure 3 to Figure 4 . The proximal end of the irrigation tube (180) is coupled to the fluid conduit (40) (e.g., at the handle (110) of the catheter assembly (100)). The irrigation tube (180) extends along the length of the catheter (120) to reach the end effector (140). In some versions, the irrigation fluid can be transmitted from the distal end of the irrigation tube (180) through the central passage formed by the aligned above-mentioned central holes, and finally reach the interior of the distal tip member (142) via the hole (158) of the distal tip base (144).

[0040] As mentioned above and as Figures 2 to 4 As shown, the catheter (100) of this example further includes a pair of push-pull cables (160, 170). The push-pull cables (160, 170) enable the physician (PH) to selectively deflect the end effector (140) laterally away from the longitudinal axis (LL), thereby enabling the physician (PH) to actively manipulate the end effector (140) within the patient (PA). Various mechanisms that can be used to drive the push-pull cables (160, 170) in a simultaneous longitudinally opposed manner will be apparent to those skilled in the art in view of the teachings herein.

[0041] III. Exemplary Catheter Configurations for Eliminating Static and Noise

[0042] As described above, the distal tip (142) of the end effector (140) defines a plurality of openings (158) configured to allow irrigation fluid to be transmitted from the interior of the distal tip member (142) to the exterior. Also as described above, the end effector (140) is configured to be disposed within or near the heart (H) of the patient (PA) to ablate tissue. Thus, during an exemplary use, the pump (44) may drive irrigation fluid from the fluid source (42) through the catheter (40) and the irrigation tube (180) and into the interior of the distal tip member (142), so that the irrigation fluid from the fluid source (42) may flow out of the plurality of openings (158) and into or near the heart (H) of the patient (PA). As described above, the irrigation fluid may be used during an exemplary use of the catheter assembly (100) to sufficiently cool the end effector (140) or surrounding tissue in response to activating the end effector (140) with RF energy.

[0043] One type of pump (44) that can be used is a peristaltic pump. In a peristaltic pump, the irrigation fluid can be contained within a flexible tube such as a catheter (40) (e.g., Figure 1 ), the tube is assembled in a semicircular pump housing commonly referred to as a "track". The catheter (40) is pressed against the track by a rotor having two or more rollers attached to its outer circumference. As the rotor turns, the compressed portion of the catheter (40) is blocked or clamped closed between the rollers and the track, forcing the pumped fluid to move through the catheter (40). When the catheter (40) reopens to its natural shape after the rollers of the pump (44) pass, a vacuum is created, thereby drawing the fluid into the pump (44). The advancing rollers then push the fluid toward the pump outlet. For some medical procedures, the catheter (40) may be built into a disposable tube set that can be discarded after each procedure, thereby minimizing cleaning validation.

[0044] In some catheter systems, the irrigation tubing contacts moving parts of the system, such as pumps (e.g. Figure 1 The roller of the pump (44) shown in FIG. 1 is connected to the flushing pipe (eg Figure 1 Static electricity buildup and discharge may occur on the catheter (40) shown in FIG. In some cases, the buildup and discharge of static electricity can generate noise in the RF system at repetitive harmonics consistent with the flow rate of the irrigation pump. This static-based noise can adversely affect the flow of EP mapping electrodes (e.g., Figure 2 and Figure 3 In addition, or in the alternative, such electrostatically based noise may adversely affect the readings of one or more sensors (e.g., Figure 3 and Figure 4 In addition, or in the alternative, such static-based noise may adversely affect the signals generated by the ablation electrodes (e.g., Figures 2 to 4 The cylindrical body (156) shown in FIG. 1 is used to deliver ablative RF energy.

[0045] Figure 5 A longitudinal cross-sectional view of a prior art irrigation tube (500) is shown, the irrigation tube being in use and positioned adjacent to a pump roller (502) of a peristaltic pump configured to drive fluid through the irrigation tube (500). The irrigation tube (500) includes a single material layer (504), such as a flexible polymer layer. An exemplary initial static charge accumulation (506) adjacent to the irrigation pump roller (502) is also shown, wherein the single material layer (504) collects static charge accumulation (506) over time. In this prior art configuration, static charge (506) may accumulate on the irrigation tube (500) each time the irrigation pump roller (502) contacts the irrigation tube (500) due to a triboelectric effect. The static charge (506) may cause a spike in electrical noise driven by the frequency at which the pump roller (502) contacts the irrigation tube (500), which noise may be determined by oppositely charged particles (508) provided by the irrigation flow through the irrigation tube (500).

[0046] To minimize the accumulation and discharge of static electricity, and to reduce any electrical noise caused by static electricity, one or more polymer coatings may be applied to the irrigation tube. Figure 6 to Figure 7 An example of a medical irrigation tube (600) is shown, which can be used with Figure 1The invention can be used in conjunction with variations of the catheter assembly (100) of the present invention. For example, the irrigation tube (600) can be used in place of the catheter (40) and can be similarly coupled to a pump (e.g., pump (44)) to deliver irrigation fluid from a fluid source (e.g., fluid source (42)) to the patient (PA). The irrigation tube (600) of this example includes multiple layers of flexible material, including a base or inner layer (602) and a coating (604). Optionally, the irrigation tube (600) can include an additional wear-resistant layer (606) that can coat a portion or all of the irrigation tube (600); and can be applied to cover the coating (604).

[0047] In some versions, inner layer (602) is formed from a flexible synthetic plastic polymer such as polyvinyl chloride (PVC). Inner layer (602) may, for example, be extruded or otherwise manufactured to form a hollow cylindrical tube defining a central longitudinal axis (608). Hollow interior portion (610) may be used as a lumen or flushing channel to convey fluid, such as between a fluid source (42) and a patient (PA).

[0048] The outer coating (604) is formed of a conductive polymer composed of one or more isomers, such as poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS). PEDOT:PSS is a polymer mixture of two ionomers. One component in the mixture is composed of sodium polystyrene sulfonate (i.e., sulfonated polystyrene). A portion of the sulfonyl groups are deprotonated and carry a negative charge. The other component, poly(3,4-ethylenedioxythiophene), is a conjugated polymer and carries a positive charge and is based on polythiophene. PEDOT:PSS can be made highly conductive or highly resistive, optically transparent (e.g., about 65% to about 90%), and slightly elastic.

[0049] Wear layer (606) may be formed, for example, of polyurethane, polyolefin, or another polymer having similar properties. Wear layer (606) may coat a portion of irrigation tube (600), such as a portion adjacent to peristaltic pump roller (502) or any other area that may experience greater wear during use.

[0050] Fig. 8A Shows Figure 6 to Figure 7 6 is a longitudinal cross-sectional view of an irrigation tube (600) in use and positioned adjacent to a pump roller (612) of a peristaltic pump configured to drive fluid through the irrigation tube (600). The irrigation tube (600) includes two layers of material: an inner layer (602) and an outer coating (604). Although not shown, the irrigation tube (600) may optionally include a wear-resistant layer, such as the wear-resistant layer (606) described above.

[0051] Fig. 8AAlso shown in FIG. 6 is an exemplary initial static charge accumulation (614) adjacent to the irrigation pump roller (612), wherein the outer coating (604) receives the static charge accumulation (614) when the pump roller (612) contacts the irrigation tube (600). In this exemplary configuration, static charge (614) can accumulate on the irrigation tube (600) each time the irrigation pump roller (612) contacts the irrigation tube (600) due to the triboelectric effect. However, as Figure 8B As shown, the high resistance formulation of PEDOT:PSS of the outer coating (604) can be used as a dissipation tool to prevent the free electrons from the pump roller (612) from being localized in one area, such as Fig. 8A As shown in Figure 6. Since the outer coating (604) is still slightly conductive and not as insulating as the inner layer (602), the electrons will not remain stationary but will move as Figure 8B As shown in the dissipation. Since this is a dissipative method, thereby preventing the accumulation of electrons instead of causing them to flow elsewhere, the irrigation tube (600) may not require electrical grounding. Therefore, the outer coating (604) can be minimal. The conductivity of the outer coating (604) (such as provided by PEDOT:PSS) allows static charges (614) to have a flow path, while the transparency of the combination of the inner layer (602) and the outer coating (604) allows bubbles to be detected within the tube. In addition, the elasticity of the combination of the inner layer (602) and the outer coating (604) gives the irrigation tube (600) the ability to bend and strain.

[0052] IV. Exemplary Semiconductive Intermediate Layer on Irrigation Tubing for Reducing Pump-Generated ECG Noise

[0053] As mentioned above, for therapeutic and diagnostic devices, electrical noise can be problematic under certain environmental conditions. For example, in some catheter systems, since the irrigation tubing contacts moving parts of the system, such as pumps (e.g. Figure 1 The roller of the pump (44) shown in FIG. 1 is connected to the flushing pipe (eg Figure 1 Static electricity accumulation and discharge may occur on the catheter (40) shown in FIG. In some cases, the accumulation and discharge of static electricity can generate noise in the RF system at repetitive harmonics consistent with the flow rate of the irrigation pump. This static electricity-related noise can adversely affect the flow from the EP mapping electrodes (e.g., Figure 2 and Figure 3 In addition, or in the alternative, such static-related noise may adversely affect the readings of one or more sensors (e.g., Figure 3 and Figure 4 In addition, or in the alternative, such static-related noise may adversely affect the signal generated by the ablation electrode (e.g., Figures 2 to 4 The cylindrical body (156) shown in FIG. 1 is used to deliver ablative RF energy.

[0054] Figures 9 and 10 Another example of a medical irrigation tube (900) is shown, which can be used with Figure 1 The invention can be used in conjunction with variations of the catheter assembly (100) of the present invention. For example, the irrigation tube (900) can be used in place of the fluid conduit (40) and can be similarly coupled to a pump (e.g., pump (44)) to deliver irrigation fluid from a fluid source (e.g., fluid source (42)) to a patient (PA). The irrigation tube (900) of this example includes multiple layers of flexible material, including a base or inner layer (902), an intermediate layer (904), and an outer coating (906). In some versions, the entire inner layer (902) and the outer coating surface (906) can be formed as an electrical insulator and each is electrically isolated from the outside of the irrigation tube (900). In some versions, the inner layer (902) and the outer coating (906) can include one or more insulating layers containing significantly different materials. The inner layer (902) can, for example, be extruded or otherwise manufactured to form a hollow cylindrical tube defining a central longitudinal axis (908). Hollow interior portion (910) may be used as a lumen or irrigation channel to transfer fluid, such as between a fluid source (42) and a patient (PA).

[0055] Although the inner layer (902) and the outer coating (906) may comprise materials having insulating properties, the semi-conductive surface may form the entire middle layer (904) of the irrigation tube, or may extend only the section of the irrigation tube (900) where the pump roller (502) contacts the irrigation tube (900). By using a semi-conductive material for the middle layer (904), such as a material having a resistance in the range of about 100 kΩ to about 1 MΩ, the charge on the outer coating surface (906) of the irrigation tube (900) may be electrically grounded, and the risk of electric shock may be minimized. However, in some versions, a conductive middle layer (904) may be used if the inner layer (902) and the outer layer (906) of the irrigation tube (900) have sufficient electrical insulation. In other versions, the conductive or semi-conductive middle layer (904) may be connected to a ground cable.

[0056] In other versions, irrigation tube (900) may comprise three layers of different materials throughout the length of irrigation tube (900). For example, one or more of the semiconductive layers may comprise a coating or braid; or may be coextruded onto inner layer (902). In addition to being semiconductive, the semiconductive layers may also have antistatic properties. In this embodiment, the conductive layers may be electrically connected to a ground cable for additional noise reduction.

[0057] V. Exemplary Combinations

[0058] The following examples relate to various non-exhaustive ways in which the teachings herein may be combined or applied. It should be understood that the following examples are not intended to limit the coverage of any claims that may be provided at any time in this patent application or in the subsequent submissions of this patent application. It is not intended to make a disclaimer. The following examples are provided only for illustrative purposes. It is expected that the various teachings herein may be arranged and applied in a variety of other ways. It is also contemplated that some variations may omit certain features mentioned in the following examples. Therefore, any of the aspects or features mentioned below should not be considered decisive, unless otherwise, for example, by the inventor or the successor of the inventor concerned clearly indicates so at a later date. If any claim proposed in this patent application or in the subsequent submissions related to this patent application includes additional features other than those mentioned below, these additional features should not be assumed to be added for any reason related to patentability.

[0059] Example 1

[0060] A device comprising a catheter, the catheter comprising: (a) a flexible outer sheath, the flexible outer sheath defining a first lumen; and (b) a flexible irrigation tube, the flexible irrigation tube being positioned within the first lumen and comprising: (i) an inner layer, the inner layer being formed of a synthetic polymer compound, the inner layer having a uniform cross-section and a hollow interior, the hollow interior defining a second lumen, and (ii) an outer coating, the outer coating being disposed around the inner layer, the outer coating being formed of a polymer compound including a first isomer configured to carry a positive charge and a second isomer configured to carry a negative charge; the second lumen being configured to transport a fluid.

[0061] Example 2

[0062] In accordance with the device of Example 1, the combined inner layer and outer coating of the flexible irrigation tube are configured to be at least partially light transmissive such that the fluid is visible through the combined inner layer and outer coating.

[0063] Example 3

[0064] According to the device of any one or more of embodiments 1-2, the synthetic polymer compound of the inner layer includes polyvinyl chloride (PVC).

[0065] Example 4

[0066] In the apparatus of any one or more of Embodiments 1-3, the outer coating of the flexible irrigation tube comprises a conductive polymer.

[0067] Example 5

[0068] According to one or more of the devices of embodiments 1-4, the first isomer of the polymer compound of the outer coating is poly(3,4-ethylenedioxythiophene).

[0069] Example 6

[0070]

[00136] According to the device of any one or more of embodiments 1-5, the second isomer of the polymer compound of the outer coating is poly(styrene sulfonate).

[0071] Example 7

[0072] According to any one or more of embodiments 1-6, the outer coating comprises poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate).

[0073] Example 8

[0074] According to the device of any one or more of embodiments 1-7, the outer coating has an optical transmittance of about 65% to about 90%.

[0075] Example 9

[0076] According to the device of any one or more of embodiments 1-8, the outer coating is at least partially elastic.

[0077] Example 10

[0078] According to the device described in any one or more of Examples 1-9, the device also includes a peristaltic pump having two or more pump rollers, and the flexible irrigation tube is configured to be connected to the peristaltic pump and deformed by each of the two or more pump rollers.

[0079] Embodiment 11

[0080] In accordance with the apparatus of Example 10, the outer coating of the flexible irrigation tube is configured as a path for free electrons to move from the peristaltic pump to a grounding element.

[0081] Example 12

[0082] According to the apparatus of any one or more of embodiments 1-11, the flexible irrigation tube further comprises a wear-resistant coating disposed around a portion of the outer coating, the wear-resistant coating being formed of a polymer.

[0083] Embodiment 13

[0084] According to the device of embodiment 12, the wear-resistant coating is formed of polyurethane.

[0085] Embodiment 14

[0086] According to the device of embodiment 12, the wear-resistant coating is formed of polyolefin.

[0087] Embodiment 15

[0088] In accordance with the apparatus of any one or more of Examples 1-14, the catheter further comprises an end effector positioned at a distal end of the catheter, the end effector comprising one or more radio frequency electrodes configured to ablate tissue.

[0089] Example 16

[0090] In accordance with the device of Example 15, the end effector of the catheter further comprises at least one mapping electrode configured to receive an electrical potential from tissue.

[0091] Embodiment 17

[0092] In accordance with the apparatus of any one or more of Examples 15-16, the end effector of the catheter further comprises a plurality of openings configured to discharge the fluid delivered through the second lumen.

[0093] Embodiment 18

[0094] A medical tube comprising: (a) an inner layer formed of a synthetic polymer compound, the inner layer having a uniform cross-section and a hollow interior, the hollow interior defining an inner lumen; (b) an outer coating disposed around the inner layer, the outer coating formed of a polymer compound including: (i) a first isomer configured to carry a positive charge and (ii) a second isomer configured to carry a negative charge; the inner lumen is configured to transport a fluid; and the combined inner layer and outer coating are configured to be transparent so that the fluid can be seen through the combined inner layer and outer coating.

[0095] Embodiment 19

[0096] The medical tube according to Embodiment 18, wherein the outer coating is poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate).

[0097] Embodiment 20

[0098]

[00136] According to any one or more of embodiments 18-19, the outer coating has an optical transmittance of about 65% to about 90%.

[0099] Embodiment 21

[0100] According to any one or more of Examples 18-20, the medical tube further comprises a wear-resistant coating disposed around a portion of the outer coating, the wear-resistant coating being formed of a polymer.

[0101] Embodiment 22

[0102] According to the medical tube of Example 21, the wear-resistant coating is formed of polyurethane.

[0103] Embodiment 23

[0104] According to the medical tube of Example 21, the wear-resistant coating is formed of polyolefin.

[0105] Embodiment 24

[0106] A method of manufacturing a medical tube, the method comprising: (a) extruding an inner tube layer from a synthetic polymer compound, the inner tube layer having a uniform cross-section and a hollow interior, the hollow interior defining an inner cavity configured to transport a fluid; (b) providing an outer coating to surround the entire inner tube layer, the outer coating being formed from a polymeric compound including a first isomer configured to carry a positive charge and a second isomer configured to carry a negative charge, the combined inner and outer coatings being configured to be light transmissive so that the fluid can be at least partially seen through the combined inner and outer coatings; and (c) providing an abrasion-resistant coating to surround a portion of the outer coating, the abrasion-resistant coating being formed from a polymer.

[0107] Embodiment 25

[0108] The method of embodiment 24 wherein the synthetic polymer compound consists of polyvinyl chloride.

[0109] Embodiment 26

[0110] The medical tube according to any one or more of embodiments 24-25, wherein the outer coating is composed of poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate).

[0111] Embodiment 27

[0112] According to any one or more of the methods described in Examples 24-26, the wear-resistant coating is composed of one of polyurethane or polyolefin.

[0113] Embodiment 28

[0114] A device comprising a catheter, the catheter comprising: (a) an inner tube, the inner tube being composed of a first flexible material, the inner tube having an inner surface defining an inner cavity configured to transport a fluid, the first flexible material being non-conductive; (b) an intermediate layer, the intermediate layer being disposed around the inner tube, the intermediate layer being composed of a second flexible material, the second flexible material being conductive; and (c) an outer layer, the outer layer being disposed around the intermediate layer, the outer layer being composed of a third flexible material, the third flexible material being non-conductive.

[0115] Embodiment 29

[0116] According to the device of claim 28, the second flexible material of the intermediate layer has a resistance of about 100 kΩ to about 1 MΩ.

[0117] Embodiment 30

[0118] According to the device of any one or more of embodiments 28-29, the second flexible material of the intermediate layer is semiconductive.

[0119] Embodiment 31

[0120] According to the device described in any one or more of Examples 28-30, the device also includes a peristaltic pump having two or more pump rollers, and the catheter is configured to be connected to the peristaltic pump and can be deformed by each of the two or more pump rollers.

[0121] Embodiment 32

[0122] In accordance with the apparatus of any one or more of Examples 28-31, the catheter further comprises an end effector positioned at a distal end of the catheter, the end effector comprising one or more radio frequency electrodes configured to ablate tissue.

[0123] Embodiment 33

[0124] In accordance with the device of Example 32, the end effector of the catheter further comprises at least one mapping electrode configured to receive an electrical potential from the tissue.

[0125] Embodiment 34

[0126] In accordance with the apparatus of any one or more of Examples 32-33, the end effector of the catheter further comprises a plurality of openings configured to discharge fluid from the lumen.

[0127] VI. Miscellaneous

[0128] Any of the instruments described herein can be cleaned and sterilized before and / or after the procedure. In one sterilization technique, the device is placed in a closed and sealed container such as a plastic bag or a TYVEK bag. The container and device can then be placed in a radiation field that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons. The radiation can kill bacteria on the device and in the container. The sterilized device can then be stored in a sterile container for later use. The device can also be sterilized using any other technique known in the art, including but not limited to beta or gamma radiation, ethylene oxide, hydrogen peroxide, peracetic acid, and vapor phase sterilization (with or without gas plasma or steam).

[0129] It should be understood that any examples described herein may also include various other features in addition to or in place of those described above. By way of example only, any examples described herein may also include one or more of the various features disclosed in any of the various references incorporated herein by reference.

[0130] It should be understood that any one or more of the teachings, expressions, embodiments, examples, etc. described herein may be combined with any one or more of the other teachings, expressions, embodiments, examples, etc. described herein. Therefore, the above teachings, expressions, embodiments, examples, etc. should not be considered isolated from each other. With reference to the teachings herein, various suitable ways in which the teachings herein can be combined will be apparent to those skilled in the art. Such modifications and variations are intended to be included within the scope of the claims.

[0131] It should be understood that any patent, patent publication, or other public material, whether in whole or in part, allegedly incorporated herein by reference is incorporated herein only to the extent that the incorporated material does not conflict with existing definitions, statements, or other public materials described in the present disclosure. Therefore, and to the extent necessary, the disclosure explicitly listed herein supersedes any conflicting material incorporated herein by reference. Any material or portion thereof allegedly incorporated herein but conflicting with existing definitions, statements, or other public materials listed herein will be incorporated only to the extent that there is no conflict between the incorporated material and the existing public materials.

[0132] While various versions of the invention have been shown and described, further improvements to the methods and systems described herein may be achieved by appropriate modifications by those skilled in the art without departing from the scope of the invention. Several such possible modifications have been mentioned, and other modifications will be apparent to those skilled in the art. For example, the examples, versions, geometries, materials, dimensions, ratios, steps, etc. discussed above are exemplary and not required. Therefore, the scope of the invention should be considered in light of the following claims and should be understood not to be limited to the details of the structure and operation shown and described in the specification and drawings.

Claims

1. A catheter, comprising: an elongated catheter body having at least one lumen extending therethrough; an end effector at a distal end of the elongated catheter body, the end effector comprising one or more openings; a flexible irrigation tube extending through the at least one lumen of the catheter body and having a distal end in fluid communication with the end effector and a proximal end extending beyond the proximal end of the catheter body and in communication with an irrigation fluid source, the irrigation tube comprising concentric inner and outer coatings; The inner layer comprises a synthetic polymer compound and has a uniform cross-section and a hollow interior configured to deliver the irrigation fluid from the irrigation fluid source to the end effector and out through the one or more openings, and The outer coating includes a polymer compound including a first isomer configured to carry a positive charge and a second isomer configured to carry a negative charge; The end effector of the catheter includes a dome-shaped tip electrode including a plurality of openings configured to exhaust the irrigation fluid received in the dome-shaped tip electrode from the irrigation tube.

2. The catheter of claim 1, the combined inner layer and outer coating of the flexible irrigation tube being configured to be at least partially light transmissive such that the fluid is visible through the combined inner layer and outer coating.

3. The catheter of claim 1, the synthetic polymer compound of the inner layer comprising polyvinyl chloride (PVC).

4. The catheter of claim 1, the outer coating of the flexible irrigation tube comprising a conductive polymer.

5. The catheter of claim 1, the first isomer of the polymer compound of the outer coating being poly(3,4-ethylenedioxythiophene).

6. The catheter of claim 1, the second isomer of the polymer compound of the outer coating being poly(styrene sulfonate).

7. The catheter of claim 1, the outer coating comprising poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate).

8. The catheter of claim 1, the outer coating having an optical transmittance of 65% to 90%.

9. The catheter of claim 1, the outer coating being at least partially elastic.

10. The catheter of claim 1, the apparatus comprising the catheter further comprising a peristaltic pump having two or more pump rollers, the flexible irrigation tube being configured to be coupled to the peristaltic pump and to be deformed by each of the two or more pump rollers.

11. The catheter of claim 10, the outer coating of the flexible irrigation tube being configured as a path for free electrons to move from the peristaltic pump to a ground element.

12. The catheter of claim 1, the flexible irrigation tube further comprising a wear-resistant coating disposed around a portion of the outer coating, the wear-resistant coating being formed of a polymer.

13. The catheter according to claim 12, wherein the wear-resistant coating is formed of polyurethane or polyolefin.

14. The catheter of claim 1, further comprising an end effector positioned at a distal end of the catheter, the end effector comprising one or more electrodes configured to ablate tissue or receive an electrical potential from tissue.

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