Patent Application
20150105772
The invention generally pertains to percutaneous and intravascular devices for nerve modulation and/or ablation.
Certain treatments involve, and in some cases require, the temporary or permanent interruption or modification of select nerve function. One example treatment is renal nerve ablation, which can be used to treat conditions related to congestive heart failure. The kidneys produce a sympathetic response to congestive heart failure, which, among other effects, increases the undesired retention of water and/or sodium. Ablating some of the nerves running to the kidneys may reduce or eliminate this sympathetic function, which may provide a corresponding reduction in the associated undesired symptoms.
Many body tissues, such as nerves, including renal nerves, brain tissue, cardiac tissue and the tissue of other body organs, are in close proximity to blood vessels and/or other body cavities. This proximity enables the tissues to be accessed percutaneously or intravascularly through walls of the blood vessels. In some instances, it may be desirable to ablate perivascular nerves using a radio frequency (RF) electrode. In other instances, the perivascular nerves may be ablated by other techniques, including procedures that apply thermal, ultrasonic, laser, microwave, and/or other related energy sources to the vessel wall.
It may be beneficial to provide apparatuses and methods including, but not limited to, renal nerve modulation systems as well as methods of use and manufacture thereof, that provide reliable multi-point ablation.
The present disclosure is directed to an intravascular nerve modulation system for performing nerve ablation.
Accordingly, one illustrative embodiment includes an intravascular nerve modulation device including an elongate shaft having a proximal end region and a distal end region. An expandable basket having a proximal end region and a distal end region may be affixed to the elongate shaft adjacent to the distal end region of the elongate shaft. The basket may further include an insulating coating disposed over a least a portion of the expandable basket. One or more electrically conductive regions may be disposed along a portion of the distal end region of the expandable basket.
Another illustrative embodiment includes an elongate shaft having a proximal end region and a distal end region. A self-expanding basket including a plurality of interconnected struts forming a network of cells and having a proximal end region and a distal end region, may be affixed to the elongate shaft adjacent to the distal end region of the elongate shaft. The basket may further include an insulating coating disposed over a least a portion of the basket. One or more electrically conductive regions may be disposed along a portion of the distal end region of the basket.
Another illustrative embodiment includes a method for manufacturing a medical device. The method may include coating an expandable basket formed of a conductive material with an insulating material. Selective portions of the insulating material may be removed to define electrically conductive regions.
The above summary of some embodiments is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The Figures, and Detailed Description, which follow, more particularly exemplify these embodiments.
The invention may be more completely understood in consideration of the following detailed description of various embodiments in connection with the accompanying drawings, in which:
While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit aspects of the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.
The following description should be read with reference to the drawings, wherein like reference numerals indicate like elements throughout the several views. The drawings, which are not necessarily to scale, are not intended to limit the scope of the claimed invention. The detailed description and drawings illustrate exemplary embodiments of the claimed invention.
All numbers used or otherwise included herein should be considered to be modified by the term “about.” The disclosure or recitation of numerical ranges by endpoints includes all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).
As used in this specification and the appended claims, the singular indefinite articles “a,” “an,” and the definite article “the,” should be considered to include or otherwise cover both single and plural referents, unless the content clearly dictates otherwise. In other words, these articles are applicable to one or more referents. As used in this specification and the appended claims, the term “or” should be considered to mean “and/or,” unless the content clearly dictates otherwise.
References in the specification to “an embodiment,” “some embodiments,” “other embodiments,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Further, if a particular feature, structure, or characteristic is described in connection with an embodiment, then it would be within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments, whether or not explicitly described, unless clearly stated to the contrary.
Certain treatments require the temporary or permanent interruption or modification of select nerve function. One example treatment is renal nerve ablation, which is sometimes used to treat conditions related to hypertension, congestive heart failure, diabetes, or other conditions impacted by high blood pressure or salt retention. The kidneys produce a sympathetic response to congestive heart failure, which, among other effects, increases the undesired retention of water and/or sodium. Ablating some of the nerves running to the kidneys may reduce or eliminate this sympathetic function, which may provide a corresponding reduction in the associated undesired symptoms.
Many of the devices and methods are disclosed herein in the context of renal nerve modulation through a blood vessel wall. However, devices and methods of other embodiments may be used in other contexts, such as applications other than where nerve modulation and/or ablation are desired. It is contemplated that the devices and methods may be used in other treatment locations and/or applications where nerve modulation and/or other tissue modulation including heating, activation, blocking, disrupting, or ablation are desired, such as, but not limited to: blood vessels, urinary vessels, or in other tissues via trocar and cannula access. For example, the devices and methods described herein can be applied to hyperplastic tissue ablation, cardiac ablation, pulmonary vein isolation, tumor ablation, benign prostatic hyperplasia therapy, nerve excitation or blocking or ablation, modulation of muscle activity, hyperthermia or other warming of tissues, etc. The disclosed methods and apparatus can be applied to any relevant medical procedure, involving both human and non-human subjects. The term modulation refers to ablation and other techniques that may alter the function of affected nerves and other tissue. In some embodiments, a single ablation device may be used to sequentially or simultaneously perform multiple ablations, if desired.
In the following disclosure, the terms energy delivery regions, electrically conductive regions, electrode, and electrodes may be considered to be equivalent to elements capable of ablating adjacent tissue. The disclosure of “adjacent tissue” is intended to cover any tissue located sufficiently proximate the electrode(s) for ablation, and the locations and distances involved are intended to vary depending on application and/or other factors.
The power and control unit 18 may include monitoring elements to monitor parameters, such as power, temperature, voltage, pulse size, impedance and/or shape, and/or other suitable parameters. The power and control unit 18 may also include, or otherwise be used with, sensors mounted along the renal nerve modulation device, as well as suitable controls for performing the desired procedure. In some embodiments, the control unit 18 may control a radio frequency (RF) electrode. The electrode may be configured to operate at a frequency of approximately 460 kHz. However, any desired frequency in the RF range may be used, for example, from 450-500 kHz. In addition, other types of ablation devices may be used as desired including, but not limited to, devices that involve resistance heating, ultrasound, microwave, and laser technologies. The power and control unit 18 may supply different forms of power to these devices.
The device 100 may include an elongate catheter shaft 106 having a proximal end (not shown) and a distal end region 108. The elongate shaft 106 may extend proximally from the distal end region 108 to the proximal end configured to remain outside of a patient's body. Although not shown, the proximal end of the elongate shaft 106 may include a hub attached thereto for connecting other treatment devices or providing a port for facilitating other treatments. It is contemplated that the stiffness of the elongate shaft 106 may be modified to form the modulation device 100 for use in various vessel diameters and various locations within the vascular tree.
In some instances, the elongate shaft 106 may have an elongate tubular structure and may include one or more lumens extending therethrough. In some embodiments, the elongate shaft 106 may include one or more guidewire or auxiliary lumens. In some instances, the elongate shaft 106 may include a separate lumen(s) (not shown) for infusion of fluids, such as saline or dye for visualization or for other purposes such as the introduction of a medical device, and so forth. The fluid may facilitate cooling of the modulation device 100 during the ablation procedure, in addition to the cooling of a body lumen. Further, the lumens may be configured in any way known in the art. For example, the lumen(s) may extend along the entire length of the elongate shaft 106 such as in an over-the-wire catheter or may extend only along a distal portion of the elongate shaft 106 such as in a single operator exchange (SOE) catheter. These examples are not intended to be limiting, but rather examples of some possible configurations. While not explicitly shown, the modulation device 100 may further include temperature sensors/wire, an infusion lumen, radiopaque marker bands, fixed guidewire tip, a guidewire lumen, and/or other components to facilitate the use and advancement of the device 100 within the vasculature.
Further, the elongate shaft 106 may have a relatively long, thin, flexible tubular configuration. In some instances, the elongate shaft 106 may have a generally circular cross-section, however, other suitable configurations such as, but not limited to, rectangular, oval, irregular, or the like may also be contemplated. In addition, the elongate shaft 106 may have a cross-sectional configuration adapted to be received in a desired vessel, such as a renal artery. For instance, the elongate shaft 106 may be sized and configured to accommodate passage through an intravascular path, which leads from a percutaneous access site in, for example, the femoral, brachial, or radial artery, to a targeted treatment site, for example, within a renal artery.
The modulation device 100 may further include an expandable basket 110 having a proximal end region 112, a distal end region 114, and an optional bridge segment 124 disposed therebetween. In some instances, in the expanded state, the bridge segment 124 may span between a collapsed proximal end region 112 and the expanded distal end region 114. It is contemplated that the bridge segment 124 have a different pattern or structure than the proximal end region 112 and/or distal end region, as will be discussed in more detail below. In the expanded configuration (shown in
In some embodiments, the expandable basket 110 may be laser cut from a generally tubular member to form a desired pattern. While the expandable basket 110 is illustrated as having an open cell, generally stent-like, structure it is contemplated that the basket 110 may be formed to have any of a number of different configurations. In some embodiments, the expandable basket 110 may be formed from a plurality of interconnected circumferentially extending struts 116. The struts 116 may have an undulating or serpentine shape, although this is not required. The struts 116 may be connected by one or more connectors 117. It is contemplated that the struts 116 in combination with the connectors 117 may form a cellular configuration with each cell having any shape desired, such as, but not limited to: circular, square, oval, rectangular, polygonal, etc. In some instances, the basket 110 may be formed from a number of generally longitudinally extending tines or may be formed from one or more filaments that may be woven, braided, knotted, etc. These are just examples. It is further contemplated that while the basket 110 is illustrated as including four struts 116 in the distal end region 114, the expandable basket 110 may include any number of struts 116 desired, such as, but not limited to, one, two, three, four, or more. It is further contemplated that the struts 116 may be spaced along the length of the basket 110 from the proximal end region 112 to the distal end region 114 as desired.
It is contemplated that the expandable basket 110 can be made from a number of different materials such as, but not limited to, metals, metal alloys, shape memory alloys and/or polymers, as desired, enabling the basket 110 to be expanded into shape when positioned within the body. For example, the expandable basket 110 can be formed from alloys such as, but not limited to, nitinol or Elgiloy®. Depending on the material selected for construction, the basket 110 may be self-expanding or may require an actuation mechanism, as will be discussed in more detail below. In some embodiments, fibers may be used to make the expandable basket 110, which may be cored fibers, for example, having an outer shell made of nitinol and a platinum core. It is further contemplated that the expandable basket 110 may be formed from or partially from polymers including, but not limited to, polyether ether ketone (PEEK), nylon, polyethylene terephthalate (PET), polyimides, polyether block amides, etc. In some embodiments, the expandable basket 110 may further include radiopaque markers, bands or coatings.
The proximal end region 112 of the basket 110 may be secured to or adjacent to the distal end region 108 of the elongate shaft 106. As noted above, in some instances, the basket 110 may be self-expanding. It is contemplated that a self-expanding basket 110 may be maintained in a compressed (or collapsed) state when an external force is placed on the basket 110. The basket 110 may then expand when the external force is released. In such an instance, the basket 110 may be formed in the expanded state (as shown in
In other embodiments, the device 100 may include an actuation mechanism, for example, a pull wire (not explicitly shown), which may be employed to manipulate or actuate the expandable basket 110 between the collapsed and expanded configurations. In an embodiment, the pull wire may be attached to the proximal end region 112 of the basket 110 such that a push-pull actuation of the pull wire may manipulate the expandable basket 110, thus actuating the expandable basket 110 between the collapsed and expanded configurations.
In some embodiments, the expandable basket 110 may be formed from a conductive material covered with an insulating or semi-insulating coating 118. The expandable basket 110 may be coated with insulating material using any number of coating techniques, such as, but not limited to, dip coating, spray coating, etc. In some instances, the expandable basket 110 may be coated with parylene or other insulating material. In other instances, the coating 118 may be formed of semi-insulating materials, such as but not limited to a porous polymer or a ceramic. It is further contemplated that the coating 118 may be a very thin polymer or coating.
It is contemplated that the coating 118 may be removed from, or not applied to, one or more locations on the expandable basket 110 to form one or more electrically conductive regions 120 configured to deliver RF energy to the target region around the vessel wall 102. The one or more electrically conductive regions 120 may function as one or more electrodes for delivering RF energy to a desired treatment area, although this is not required. In some instances, the one or more electrically conductive regions 120 may be discrete elements or electrodes affixed to the basket 110.
In the expanded configuration, one or more electrically conductive regions 120 may contact the vessel wall 102. For example,
Referring again to
One or more electrical conductors (not explicitly shown) may connect the expandable basket 110 to a power and control unit which provides RF energy to the expandable basket 110. In some instances, RF energy may be supplied to the entire basket 110, but is only emitted from the electrically conductive regions 120. In other instances, RF energy may be supplied to the electrically conductive regions 120 via conductive traces (not explicitly shown) disposed in or on the basket 110. The conductive traces may connect the electrically conductive regions 120 to a power and control unit. It is contemplated that the electrically conductive regions 120 may function as multiple electrodes connected in parallel to deliver RF energy to the desired treatment region. For example, a single-channel control unit may provide power to the electrically conductive regions 120 simultaneously. This may allow for multi-point ablation while reducing procedure time compared to performing sequential ablation of discrete spots. It is further contemplated that simultaneous ablation of multiple treatment locations may also avoid or reduce overlapping treatment areas or widely separated treatment areas. In some instances, overlapping treatment areas may cause locally severe damage to the vessel or other adjacent tissue. Widely separated treatment areas may leave untreated nerves, making the therapy less effective. In some instances, providing the electrically conductive regions 120 on an inner surface of the expandable basket 110 may also reduce damage to peripheral tissues while providing consistent positioning of the conductive regions 120.
It is contemplated that the electrically conductive regions 120 may be formed about the expandable basket 110 in any manner desired to provide the desired ablation pattern.
As shown in
It is contemplated that various basket 110 geometries may be utilized. For example, the basket 110 can include more or fewer interconnecting struts 116, connectors 117, etc. In some instances, the basket geometry can be chosen to obtain greater or lesser flexibility. Baskets with more rows or rings can be used to spread out the heated areas along a longer length, at the expense of requiring a longer landing zone in the artery and having a longer stiff section, especially during introduction and positioning. It is further contemplated that various patterns of insulated and non-insulated areas can be utilized to achieve the desired geometry of ablation. For example, the depth, volume, and temperature required for the treatment of a target tissue zone may affect the electrode (electrically conductive region) configuration that is required. The size and positioning of electrically conductive regions 120 can be chosen to produce a more evenly heated zone, for example, such as by using a greater electrode area of non-wall-contact electrode(s) and a lesser area of wall contact electrode(s). Alternatively, an uneven or asymmetric heating zone can be obtained if desired.
The electrically conductive regions 120 can be positioned so that they are reliably positioned as desired in the lumen 104 when the distal end region 114 of the basket 110 expands. The configuration of the electrically conductive regions or electrodes 120 may be chosen to obtain the desired heating of a volume of tissue. Wall-contact electrodes 120 may provide more concentrated heating of nearby tissues, and non-wall-contact electrodes 120 provide less concentrated heating of deeper tissues. Electrically conductive regions 120 can be arranged in single or multiple contiguous areas, contiguous strips, circumferential rings, helical lines, or discrete spots, positioned closer or farther from each other and with various surface areas along the inside and/or outside of the basket 110 to shape the heated zone as needed. Repeated patterns or combinations of arrangements can be used. Greater heating can be provided towards one end, or toward the middle, or along one side, compared to other areas, for example.
As shown in
As shown in
As shown in
As shown in
As shown in
As shown in
As shown in
In some embodiments, the struts 916 may have a generally serpentine shape including relatively straight portions 930 and curved portions 932 joining adjacent straight portions 930. The curved portions, or hinges, 932 may have a smaller cross-sectional area than the straight portions 930. The radial expansion force of the basket may relate generally to strut width. In some configurations, the hinge 932 structure can beneficially reduce the radial expansion force since the basket 910 only needs to hold the electrically conductive regions 920 in apposition with the vessel wall and not provide a stenting expansion force to the vessel. The smaller hinges 932 may thus result in a lower expansion force of the basket 910. It is further contemplated that a wider or larger straight portion 930 may provide sufficient surface area to the electrically conductive regions 920 to reduce thermal tissue damage and/or fouling of the electrically conductive region.
In some instances, the elongate shaft 1002 may have an elongate tubular structure and may include one or more lumens 1010 extending therethrough. In some embodiments, the elongate shaft 1002 may include one or more guidewire or auxiliary lumens. In some instances, the elongate shaft 1002 may include a separate lumen(s) (not shown) for infusion of fluids, such as saline or dye for visualization or for other purposes such as the introduction of a medical device, and so forth. The fluid may facilitate cooling of the modulation system 1000 during the ablation procedure, in addition to the cooling of a body lumen. Further, the lumens may be configured in any way known in the art. For example, the lumen(s) may extend along the entire length of the elongate shaft 1002 such as in an over-the-wire catheter or may extend only along a distal portion of the elongate shaft 1002 such as in a single operator exchange (SOE) catheter. These examples are not intended to be limiting, but rather examples of some possible configurations. While not explicitly shown, the modulation system 1000 may further include temperature sensors/wire, an infusion lumen, radiopaque marker bands, fixed guidewire tip, a guidewire lumen, and/or other components to facilitate the use and advancement of the system 1000 within the vasculature.
Further, the elongate shaft 1002 may have a relatively long, thin, flexible tubular configuration. In some instances, the elongate shaft 1002 may have a generally circular cross-section, however, other suitable configurations such as, but not limited to, rectangular, oval, irregular, or the like may also be contemplated. In addition, the elongate shaft 1002 may have a cross-sectional configuration adapted to be received in a desired vessel, such as a renal artery. For instance, elongate shaft 1002 may be sized and configured to accommodate passage through an intravascular path, which leads from a percutaneous access site in, for example, the femoral, brachial, or radial artery, to a targeted treatment site, for example, within a renal artery.
The modulation system 1000 may include a delivery sheath 1006 and/or a guide catheter 1008 for facilitating advancement of the system 1000 through the vasculature. In some embodiments, the system 1000 may further include a support tube and/or guidewire 1012. The support/guidewire tube 1012 may include one or more radiopaque marker bands 1014 to facilitate placement of the system 1000. The support/guidewire tube 1012 may further include an atraumatic tip 1016.
The modulation system 1000 may further include an expandable basket 1018 having a proximal end region 1020, a distal end region 1022, and an optional bridge segment 1024 disposed therebetween. In some instances, in the expanded state, the bridge segment 1024 may span between a collapsed proximal end region 1020 and the expanded distal end region 1022. It is contemplated that the bridge segment 1024 may have a different pattern or structure than the proximal end region 1020 or distal end region 1022. For example, the bridge segment may include any number of generally longitudinally extending struts 1034 while the proximal end region 1020 and the distal end region 1022 may include any number of circumferentially extending struts. This is just an example. In the expanded configuration (shown in
In some embodiments, the expandable basket 1018 may be laser cut from a generally tubular member to form a desired pattern. While the expandable basket 1018 is illustrated as having an open cell, generally stent-like, structure it is contemplated that the basket 1018 may be formed to have any of a number of different configurations. In some embodiments, the expandable basket 1018 may be formed from a plurality of interconnected circumferentially extending struts 1026. The struts 1026 may be connected by one or more connectors 1028. It is contemplated that the struts 1026 in combination with the connectors 1028 may form a cellular configuration with each cell having any shape desired, such as, but not limited to: circular, square, oval, rectangular, polygonal, etc. In some instances, the basket 1018 may be formed from a number of generally longitudinally extending tines or may be formed from one or more filaments that may be woven, braided, knotted, etc. These are just examples. It is further contemplated that while basket 1018 is illustrated as including three struts 1026 in the distal end region 1022, the expandable basket 1018 may include any number of struts 1026 desired, such as, but not limited to, one, two, three, four, or more. It is further contemplated that the struts 1026 may be spaced from the proximal end region 1020 to the distal end region 1022 as desired.
It is contemplated that the expandable basket 1018 can be made from a number of different materials such as, but not limited to, metals, metal alloys, shape memory alloys and/or polymers, as desired, enabling the basket 1018 to be expanded into shape when positioned within the body. For example, the expandable basket 1018 can be formed from alloys such as, but not limited to, nitinol or Elgiloy®. Depending on the material selected for construction, the basket 1018 may be self-expanding or may require an actuation mechanism as will be discussed in more detail below. In some embodiments, fibers may be used to make the expandable basket 1018, which may be cored fibers, for example, having an outer shell made of nitinol and a platinum core. It is further contemplated that the expandable basket 1018 may be formed from or partially from polymers including, but not limited to, polyether ether ketone (PEEK), nylon, polyethylene terephthalate (PET), polyimides, polyether block amides, etc. In some embodiments, the expandable basket 1018 may further include radiopaque markers, bands or coatings.
The proximal end region 1020 of the basket 1018 may be secured to or adjacent to the distal end region 1004 of the elongate shaft 1002. As noted above, in some instances, the basket 1018 may be self-expanding. It is contemplated that a self-expanding basket 1018 may be maintained in a compressed (or collapsed state) when an external force is placed on the basket 1018. The basket 1018 may then expand when the external force is released. In such an instance, the basket 1018 may be formed in the expanded state (as shown in
In other embodiments, the system 1000 may include an actuation mechanism, for example, a pull wire (not explicitly shown), which may be employed to manipulate or actuate the expandable basket 1018 between the collapsed and expanded configurations. In an embodiment, the pull wire may be attached to the proximal end region 1020 of the basket 1018 such that a push-pull actuation of the pull wire may manipulate the expandable basket 1018, thus actuating the expandable basket 1018 between the collapsed and expanded configurations.
In some embodiments, the expandable basket 1018 may be formed from a conductive material covered with an insulating or semi-insulating coating 1030. The expandable basket 1018 may be coated with insulating material using any number of coating techniques, such as, but not limited to, dip coating, spray coating, etc. In some instances, the expandable basket 1018 may be coated with parylene or other insulating material. In some instances, the coating 1130 may be formed of semi-insulating materials, such as, but not limited to a porous polymer or a ceramic. It is further contemplated that the coating 1030 may be a very thin polymer or coating.
It is contemplated that the coating 1030 may be removed from or not applied to one or more locations on the expandable basket 1018 to form one or more electrode pads or electrically conductive regions 1032 configured to deliver RF energy to a target region. In some instances, the one or more electrically conductive regions 1032 may be discrete elements or electrodes affixed to the basket 1018. The one or more electrically conductive regions 1032 may function as one or more electrodes for delivering RF energy to a desired treatment area. In the expanded configuration, one or more electrically conductive regions 1032 may contact a vessel wall. For example, the coating 1030 may be absent from an outer surface of the expandable basket 1018 to form an electrically conductive region 1032 positioned to contact a vessel wall. However, it is contemplated that the coating 1030 can be removed from as many sides of the basket 1018 (inner, outer, side surfaces, etc.) as desired to provide the desired ablation energy. It is further contemplated that the coating 1030 may be absent on any single side (or combination of sides) desired. For example, in some instances, the coating 1030 may be present on a portion of the basket 1018 contacting the vessel wall but absent on any one of the sides not in contact with the wall such that the energy delivery region 1032 does not contact the vessel wall directly. In some instances, the insulating material 1030 may be absent from an inner surface of the expandable basket 1018. It is contemplated that strut 1026 may have a generally square cross-sectional shape, however the cross-section of the struts 1026 may be any shape desired. In some instances, such as, but not limited to, when a non-conductive basket 1018 is utilized, the electrically conductive regions 1032 may be separately formed of an electrically conductive material and attached to the basket 1018.
In some embodiments, the electrically conductive regions 1032 may be enlarged pad regions relative to other portions of the basket 1018. In some instances, a small electrode surface area may result in higher temperatures at the electrode which may cause increased vessel wall injury, blood damage, and/or fouling of the electrode surface. It is contemplated that the electrically conductive regions 1032 may be round, oblong, square, rectangular, polygonal, or other shape as desired. In some embodiments, the enlarged electrically conductive regions 1032 may be positioned between the circumferential struts 1026. In other embodiments, the electrically conductive regions 1032 may be formed from or on a portion of the circumferential struts 1026. It is contemplated that the size, position, and/or spacing of the electrically conductive regions 1032 may affect the power required to ablate the target tissue as well as the geometry of the heated zone. For example, fewer electrodes, greater spacing, and/or smaller electrodes may require greater power. It is contemplated that the electrically conductive regions 1032 may be formed or positioned about the expandable basket 1018 in any manner desired to provide the desired ablation pattern. As shown in
The modulation system 1000 may be advanced through the vasculature to a desired treatment region, such as the renal artery. The modulation system 1000 may be advanced with the expandable basket 1018 in a collapsed position. For example, the delivery sheath 1006 may be disposed over the basket 1018 to maintain the basket 1018 in a collapsed position. When the expandable basket 1018 is positioned adjacent to the target treatment region, the delivery sheath 1006 may be retracted to allow at least a portion of the expandable basket 1018 to contact the vessel wall. As discussed above, pull wires, or other actuation mechanisms can be used in place of or in combination with the delivery sheath 1006 to facilitate delivery of the system 1000. It is contemplated that the expandable basket 1018 may be formed such that it is sufficient to obtain contact with the vessel wall, but not strong enough to significantly expand the vessel. In some embodiments, a guide catheter 1008 or vascular access catheter may be used in combination with the delivery sheath 1006 to facilitate advancement of the system 1000. When the expandable basket 1018 is in the expanded configuration, the proximal end region 1020 may remain in a generally collapsed or low-profile configuration. In the expanded configuration, the outer surface of the expandable basket 1018, sometimes including electrically conductive regions 1032, may come into gentle contact with the vessel wall.
One or more electrical conductors (not explicitly shown) may connect the expandable basket 1018 to a power and control unit which provides RF energy to the expandable basket 1018. In some instances, RF energy may be supplied to the entire basket 1018, but is only emitted from the electrically conductive regions 1032. In other instances, RF energy may be supplied to the electrically conductive regions 1032 via conductive traces (not explicitly shown) disposed in or on the basket 1018. The conductive traces may connect the electrically conductive regions 1032 to a power and control unit. It is contemplated that the electrically conductive regions 1032 may function as multiple electrodes connected in parallel to deliver RF energy to the desired treatment region. For example, a single-channel control unit may provide power to the electrically conductive regions 1032 simultaneously. This may allow for multi-point ablation while reducing procedure time compared to performing sequential ablation of discrete spots. It is further contemplated that simultaneous ablation of multiple treatment locations may also avoid or reduce overlapping treatment areas or widely separated treatment areas. In some instances, overlapping treatment areas may cause locally severe damage to the vessel or other adjacent tissue. Widely separated treatment areas may leave untreated nerves, making the therapy less effective. In some instances, providing the electrically conductive regions 1032 on an inner surface of the expandable basket 1018 may also reduce damage to peripheral tissues while providing consistent positioning of the conductive regions 1032, but may also cause increased blood heating.
As shown in
It is contemplated that various basket 1118 geometries may be utilized. For example, the basket 1118 can include more or fewer interconnecting struts 1126, connectors 1128, etc. In some instances, the basket geometry can be chosen to obtain greater or lesser flexibility. Baskets with more rows or rings of struts 1126 can be used to spread out the heated areas more, at the expense of requiring a longer landing zone in the artery, and having a longer stiff section, especially during introduction and positioning. It is further contemplated that various patterns of insulated and non-insulated areas can be utilized to achieve the desired geometry of ablation. For example, the depth, volume, and temperature required for the treatment of a target tissue zone may affect the electrode (electrically conductive region) configuration that is required. The size and positioning of electrically conductive regions 1132 can be chosen to produce a more even heated zone, for example, such as by using a greater electrode area of non-wall-contact electrode(s) and a lesser area of wall contact electrode(s). Alternatively, an uneven or asymmetric heating zone can be obtained if desired.
The electrically conductive regions 1132 can be arranged so that they are reliably positioned as desired in the vessel when the distal end region 1122 of the basket 1118 expands. The configuration of the electrically conductive regions or electrodes 1132 may be chosen to obtain the desired heating of a volume of tissue. Wall-contact electrodes 1132 may provide more concentrated heating of nearby tissues, and non-wall-contact electrodes 1132 may provide less concentrated heating of deeper tissues. Electrically conductive regions 1132 can be arranged in in single or multiple contiguous areas, contiguous strips, circumferential rings, helical lines, or discrete spots, positioned closer or farther from each other and with various surface areas along the inside and/or outside of the basket 1118 to shape the heated zone as needed. Repeated patterns or combinations of arrangements can be used. Greater heating can be provided towards one end, or toward the middle, or along one side, compared to other areas, for example.
As shown in
As shown in
As shown in
It is contemplated that the outer surface of the basket 1518 (e.g. the surface capable of contacting a vessel wall) may be entirely coated with insulation 1530 while the electrically conductive regions 1532 are formed on an inner surface of the basket 1518. This may position the electrically conductive regions 1532 a short distance from the vessel wall when the basket 1518 is deployed. However, this is not required. It is contemplated that the electrically conductive regions may be positioned on any surface of the basket 1518 desired. In some embodiments, the electrically conductive regions 1532 may include one or more fenestrations or openings 1538. It is contemplated that openings 1538 take any shape desired such as, but not limited, longitudinal slots, holes, or apertures. In some instances, openings 1538 in the enlarged electrically conductive regions 1532 may provide additional access for electrical current to flow from the electrically conductive regions 1532 to the target tissue. This may provide more consistent off-wall heating by providing more uniform current path lengths from the electrically conductive regions 1532 to the vessel wall. It is contemplated that in the absence of openings 1538, current flowing from large electrically conductive regions or electrodes in an off-wall configuration may be less consistent due to the longer path from the center of the electrode than from the edges, which may lead to uneven heating. In some embodiments, the openings 1538 may also facilitate cooling of the vessel wall tissue at the electrically conductive regions 1532 by allowing heat transfer to the flowing blood.
As shown in
It is contemplated that various basket 1518 geometries may be utilized. For example, the basket 1518 can include more or fewer interconnecting struts 1526, connectors 1528, etc. In some instances, the basket geometry can be chosen to obtain greater or lesser flexibility. Baskets with more rows or rings of struts 1526 can be used to spread out the heated areas more, at the expense of requiring a longer landing zone in the artery, and having a longer stiff section, especially during introduction and positioning. It is further contemplated that various patterns of insulated and non-insulated areas can be utilized to achieve the desired geometry of ablation. For example, the depth, volume, and temperature required for the treatment of a target tissue zone may affect the electrode (electrically conductive region) configuration that is required. The size and positioning of electrically conductive regions 1532 can be chosen to produce a more even heated zone, for example, such as by using a greater electrode area of non-wall-contact electrode(s) and a lesser area of wall contact electrode(s). Alternatively, an uneven or asymmetric heating zone can be obtained if desired.
The electrically conductive regions 1532 can be arranged so that they are reliably positioned as desired in the vessel when the distal end region 1522 of the basket 1518 expands. The configuration of the electrically conductive regions or electrodes 1532 may be chosen to obtain the desired heating of a volume of tissue. Wall-contact electrodes 1532 may provide more concentrated heating of nearby tissues and non-wall-contact electrodes 1532 may provide less concentrated heating of deeper tissues. Electrically conductive regions 1532 can be arranged in single or multiple contiguous areas, contiguous strips, circumferential rings, helical lines, or discrete spots, positioned closer or farther from each other and with various surface areas along the inside and/or outside of the basket 1518 to shape the heated zone as needed. Repeated patterns or combinations of arrangements can be used. Greater heating can be provided towards one end, or toward the middle, or along one side, compared to other areas, for example. Openings 1538 in the electrically conductive regions 1532 may also be arranged as desired to provide the desired treatment geometry.
It is contemplated that the outer surface of the basket 1618 (e.g. the surface capable of contacting a vessel wall) may be entirely coated with insulation 1630 while the electrically conductive regions 1632 are formed on an inner surface of the basket 1618. This may position the electrically conductive regions 1632 a short distance from the vessel wall when the basket 1618 is deployed. However, this is not required. It is contemplated that the electrically conductive regions may be positioned on any surface of the basket 1618 desired. In some embodiments, the electrically conductive regions 1632 may include one or more fenestrations or openings 1638. It is contemplated that openings 1638 take any shape desired such as, but not limited, longitudinal slots, holes, or apertures. In some instances, openings 1638 in the enlarged electrically conductive regions 1632 may provide additional access for electrical current to flow from the electrically conductive regions 1632 to the target tissue.
As shown in
It is contemplated that the outer surface of the basket 1718 (e.g. the surface capable of contacting a vessel wall) may be entirely coated with insulation 1730 while the electrically conductive regions 1732 are formed on an inner surface of the basket 1718. This may position the electrically conductive regions 1732 a short distance from the vessel wall when the basket 1718 is deployed. However, this is not required. It is contemplated that the electrically conductive regions may be positioned on any surface of the basket 1718 desired. In some embodiments, the electrically conductive regions 1732 may include one or more holes or openings 1738 disposed generally in the center of the circular ring. However, it is contemplated that openings 1738 take any shape desired such as, but not limited, longitudinal slots, or other geometric configurations. In some instances, openings 1738 in the enlarged electrically conductive regions 1732 may provide additional access for electrical current to flow from the electrically conductive regions 1732 to the target tissue.
As shown in
It is contemplated that the outer surface of the basket 1818 (e.g. the surface capable of contacting a vessel wall) may be entirely coated with insulation 1830 while the electrically conductive regions 1832 are formed on an inner surface of the basket 1818. This may position the electrically conductive regions 1832 a short distance from the vessel wall when the basket 1818 is deployed. However, this is not required. It is contemplated that the electrically conductive regions may be positioned on any surface of the basket 1818 desired. In some embodiments, the electrically conductive regions 1832 may include one or more fenestrations or openings 1838 disposed generally in the center of the oblong electrically conductive regions 1832. However, it is contemplated that openings 1838 take any shape desired such as, but not limited, longitudinal slots, holes, or other geometric configurations. In some instances, openings 1838 in the enlarged electrically conductive regions 1832 may provide additional access for electrical current to flow from the electrically conductive regions 1832 to the target tissue.
As shown in
It is contemplated that the outer surface of the basket 1918 (e.g. the surface capable of contacting a vessel wall) may be entirely coated with insulation 1930 while the electrically conductive regions 1932 may be formed on an inner surface of the basket 1918. This may position the electrically conductive regions 1932 a short distance from the vessel wall when the basket 1918 is deployed. The electrically conductive regions 1932 may be separated from the vessel wall by a distance that depends on the thickness of the insulation 1930 on the outside of the basket 1918 as well as the thickness and/or width of the insulating edge 1940. This separation distance may affect the current density in the adjacent wall and deeper tissues. The width of insulating edge 1940 may be chosen to be narrower if more concentrated, shallow heating is desired or wider if deeper heating that spares the artery wall is desired. Some electrically conductive regions 1932 can have a wider insulating edge 1940, while others have a narrower insulating edge 1940, to deliver more RF energy and more heating to some areas than to others. However, it is contemplated that the electrically conductive regions 1932 may be positioned on any surface of the basket 1918 desired. For example, electrically conductive regions 1932 may be positioned on an outer surface of the basket 1918. The perimeter of insulation 1940 may maintain the electrically conductive regions 1932 a short distance from the vessel wall. It is contemplated that the insulating edge 1940 may be uniform or can vary in width to preferentially heat some tissue regions more than others. For example, the width of the insulating edge 1940 can vary along the perimeter of a single electrically conductive region 1932 or it can vary between individual electrically conductive regions 1932 or a combination thereof.
As shown in
It is contemplated that various basket 1918 geometries may be utilized. For example, the basket 1918 can include more or fewer interconnecting struts 1926, connectors 1928, etc. In some instances, the basket geometry can be chosen to obtain greater or lesser flexibility. Baskets with more rows or rings of struts 1926 can be used to spread out the heated areas more, at the expense of requiring a longer landing zone in the artery, and having a longer stiff section, especially during introduction and positioning. It is further contemplated that various patterns of insulated and non-insulated areas can be utilized to achieve the desired geometry of ablation. For example, the depth, volume, and temperature required for the treatment of a target tissue zone may affect the electrode (electrically conductive region) configuration that is required. The size and positioning of electrically conductive regions 1932 can be chosen to produce a more even heated zone, for example, such as by using a greater electrode area of non-wall-contact electrode(s) and a lesser area of wall contact electrode(s). Alternatively, an uneven or asymmetric heating zone can be obtained if desired.
The electrically conductive regions 1932 can be arranged so that they are reliably positioned as desired in the vessel when the distal end region 1922 of the basket 1918 expands. The configuration of the electrically conductive regions or electrodes 1932 may be chosen to obtain the desired heating of a volume of tissue. In some instances, the enlarged surface area of the electrically conductive regions 1932 relative to the other portions of the basket 1918 may provide room for insulation areas 1940 while still leaving sufficient electrode area. Wall-contact electrodes 1932 may provide more concentrated heating of nearby tissues and non-wall-contact electrodes 1932 may provide less concentrated heating of deeper tissues. Electrically conductive regions 1932 can be arranged in single or multiple contiguous areas, contiguous strips, circumferential rings, helical lines, or discrete spots, positioned closer or farther from each other and with various surface areas along the inside and/or outside of the basket 1918 to shape the heated zone as needed. Repeated patterns or combinations of arrangements can be used. Greater heating can be provided towards one end, or toward the middle, or along one side, compared to other areas, for example. The edge insulation 1940 thickness and/or width can be varied in combination with varying the number, size, and/or geometry (including fenestrations) of the electrically conductive regions 1932 to obtain the desired heating pattern.
It is contemplated that the outer surface of the basket 2018 (e.g. the surface capable of contacting a vessel wall) may be entirely coated with insulation 2030 while the electrically conductive regions 2032 are formed on an inner surface of the basket 2018. This may position the electrically conductive regions 2032 a short distance from the vessel wall when the basket 2018 is deployed. The electrically conductive regions 2032 may be separated from the vessel wall by a distance that depends on the thickness of the insulation 2030 on the outside of the basket 2018 as well as the thickness or width of the insulating edge 2040. This separation distance may affect the current density in the adjacent wall and deeper tissues. The width of the insulating edge 2040 may be chosen to be narrower if more concentrated, shallow heating is desired or wider if deeper heating that spares the artery wall is desired. However, it is contemplated that the electrically conductive regions may be positioned on any surface of the basket 2018 desired.
As shown in
It is contemplated that the outer surface of the basket 2118 (e.g. the surface capable of contacting a vessel wall) may be entirely coated with insulation 2130 while the electrically conductive regions 2132 are formed on an inner surface of the basket 2118. This may position the electrically conductive regions 2132 a short distance from the vessel wall when the basket 2118 is deployed. The electrically conductive regions 2132 may be separated from the vessel wall by a distance that depends on the thickness of the insulation 2130 on the outside of the basket 2118 as well as the thickness or width of the insulating edge 2140. This separation distance may affect the current density in the adjacent wall and deeper tissues. The width of the insulating edge 2140 may be chosen to be narrower if more concentrated, shallow heating is desired or wider if deeper heating that spares the artery wall is desired. However, it is contemplated that the electrically conductive regions may be positioned on any surface of the basket 2118 desired.
As shown in
It is contemplated that the outer surface of the basket 2218 (e.g. the surface capable of contacting a vessel wall) may be entirely coated with insulation 2230 while the electrically conductive regions 2232 are formed on an inner surface of the basket 2218. This may position the electrically conductive regions 2232 a short distance from the vessel wall when the basket 2218 is deployed. The electrically conductive regions 2232 may be separated from the vessel wall by a distance that depends on the thickness of the insulation 2230 on the outside of the basket 2218 as well as the thickness or width of the insulating edge 2240, 2242. This separation distance may affect the current density in the adjacent wall and deeper tissues. The width of the insulating edge 2240, 2242 may be chosen to be narrower if more concentrated, shallow heating is desired or wider if deeper heating that spares the artery wall is desired. In some embodiments, some electrically conductive regions 2232 may have a first wider insulating edge 2240 while other electrically conductive regions 2232 may have a second narrower insulating edge 2242. It is contemplated that the wider edge insulation 2240 may be present on certain struts 2226 while the narrower edge insulation 2242 may be present on other struts 2226. However, the pattern, or lack of pattern, of the width of the edge insulation 2240, 2242 may be selected to achieve the desired heating pattern. It is further contemplated that the electrically conductive regions may be positioned on any surface of the basket 2218 desired.
As shown in
In some instances, the basket 910 may be formed from a metal, or other conductive material. However, it is contemplated that the basket 2310 may be formed of a non-conductive material. In such an instance, one or more conductive traces (not explicitly shown may be provided within or on a surface of the basket 2310 to conduct RF energy to the electrically conductive regions. It is further contemplated that when a non-conductive basket 2310 is utilized electrically conductive regions may be provided as discrete electrically conductive elements affixed to a surface of the basket 2310.
In some embodiments, the expandable basket 2310 may be cut from a generally tubular member to form a basket 2310 having the desired frame 2311 geometry. It is contemplated that the tubular member may be cut using chemical, laser, electron discharge machining (EDM), or other known technologies. It is contemplated that a various heat treatment approaches can be used with particular metals to impart temper, flexibility, self-expansion, self-collapsing, or shape memory attributes using known technologies.
Once the frame 2311 has been formed, the basket 2310 may be coated, entirely or partially, by a coating 2318 such as, but not limited to parylene, fluoropolymers, porous polymers, ceramics, etc., as shown in
Regardless of whether a masking material has been used or not, once the coating 2318 has been applied, the coating 2318 may be selectively removed from the basket 2310 either at the masked location or an unmasked location. The coating 2318 may be scored 2322 as shown in
Devices 100, 1000 or any of the baskets disclosed herein may be made from a metal, metal alloy, polymer (some examples of which are disclosed below), a metal-polymer composite, ceramics, combinations thereof, and the like, or other suitable material. Some examples of suitable metals and metal alloys include stainless steel, such as 304V, 304L, and 316LV stainless steel; mild steel; nickel-titanium alloy such as linear-elastic and/or super-elastic nitinol; other nickel alloys such as nickel-chromium-molybdenum alloys (e.g., UNS: N06625 such as INCONEL® 625, UNS: N06022 such as HASTELLOY® C-22®, UNS: N10276 such as HASTELLOY® C276®, other HASTELLOY® alloys, and the like), nickel-copper alloys (e.g., UNS: N04400 such as MONEL® 400, NICKELVAC® 400, NICORROS® 400, and the like), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035 such as MP35-N® and the like), nickel-molybdenum alloys (e.g., UNS: N10665 such as HASTELLOY® ALLOY B2®), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten or tungsten alloys, and the like; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS: R30003 such as ELGILOY®, PHYNOX®, and the like); platinum enriched stainless steel; titanium; combinations thereof; and the like; or any other suitable material.
As alluded to herein, within the family of commercially available nickel-titanium or nitinol alloys, is a category designated “linear elastic” or “non-super-elastic” which, although may be similar in chemistry to conventional shape memory and super elastic varieties, may exhibit distinct and useful mechanical properties. Linear elastic and/or non-super-elastic nitinol may be distinguished from super elastic nitinol in that the linear elastic and/or non-super-elastic nitinol does not display a substantial “superelastic plateau” or “flag region” in its stress/strain curve like super elastic nitinol does. Instead, in the linear elastic and/or non-super-elastic nitinol, as recoverable strain increases, the stress continues to increase in a substantially linear, or a somewhat, but not necessarily entirely linear relationship until plastic deformation begins or at least in a relationship that is more linear that the super elastic plateau and/or flag region that may be seen with super elastic nitinol. Thus, for the purposes of this disclosure linear elastic and/or non-super-elastic nitinol may also be termed “substantially” linear elastic and/or non-super-elastic nitinol.
In some cases, linear elastic and/or non-super-elastic nitinol may also be distinguishable from super elastic nitinol in that linear elastic and/or non-super-elastic nitinol may accept up to about 2-5% strain while remaining substantially elastic (e.g., before plastically deforming) whereas super elastic nitinol may accept up to about 8% strain before plastically deforming. Both of these materials can be distinguished from other linear elastic materials such as stainless steel (that can also can be distinguished based on its composition), which may accept only about 0.2 to 0.44 percent strain before plastically deforming.
In some embodiments, the linear elastic and/or non-super-elastic nickel-titanium alloy is an alloy that does not show any martensite/austenite phase changes that are detectable by differential scanning calorimetry (DSC) and dynamic metal thermal analysis (DMTA) analysis over a large temperature range. For example, in some embodiments, there may be no martensite/austenite phase changes detectable by DSC and DMTA analysis in the range of about −60 degrees Celsius (° C.) to about 120° C. in the linear elastic and/or non-super-elastic nickel-titanium alloy. The mechanical bending properties of such material may therefore be generally inert to the effect of temperature over this very broad range of temperature. In some embodiments, the mechanical bending properties of the linear elastic and/or non-super-elastic nickel-titanium alloy at ambient or room temperature are substantially the same as the mechanical properties at body temperature, for example, in that they do not display a super-elastic plateau and/or flag region. In other words, across a broad temperature range, the linear elastic and/or non-super-elastic nickel-titanium alloy maintains its linear elastic and/or non-super-elastic characteristics and/or properties.
In some embodiments, the linear elastic and/or non-super-elastic nickel-titanium alloy may be in the range of about 50 to about 60 weight percent nickel, with the remainder being essentially titanium. In some embodiments, the composition is in the range of about 54 to about 57 weight percent nickel. One example of a suitable nickel-titanium alloy is FHP-NT alloy commercially available from Furukawa Techno Material Co. of Kanagawa, Japan. Some examples of nickel titanium alloys are disclosed in U.S. Pat. Nos. 5,238,004 and 6,508,803, which are incorporated herein by reference. Other suitable materials may include ULTANIUM™ (available from Neo-Metrics) and GUM METAL™ (available from Toyota). In some other embodiments, a superelastic alloy, for example a superelastic nitinol can be used to achieve desired properties.
In at least some embodiments, portions or all of devices 100, 1000 or any of the baskets disclosed herein may also be doped with, made of, or otherwise include a radiopaque material. Radiopaque materials are generally understood to be materials which are opaque to RF energy in the wavelength range spanning x-ray to gamma-ray (at thicknesses of <0.005″). These materials are capable of producing a relatively dark image on a fluoroscopy screen relative to the light image that non-radiopaque materials such as tissue produce. This relatively bright image aids the user of devices 100, 1000 or any of the baskets disclosed herein in determining its location. Some examples of radiopaque materials can include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloy, polymer material loaded with a radiopaque filler, and the like. Additionally, other radiopaque marker bands and/or coils may also be incorporated into the design of devices 100, 1000 or any of the baskets disclosed herein to achieve the same result.
In some embodiments, a degree of Magnetic Resonance Imaging (MRI) compatibility is imparted into devices 100, 1000 or any of the baskets disclosed herein. For example, devices 100, 1000 or any of the baskets disclosed herein, or portions thereof, may be made of a material that does not substantially distort the image and create substantial artifacts (i.e., gaps in the image). Certain ferromagnetic materials, for example, may not be suitable because they may create artifacts in an MRI image. Devices 100, 1000 or any of the baskets disclosed herein or portions thereof, may also be made from a material that the MRI machine can image. Some materials that exhibit these characteristics include, for example, tungsten, cobalt-chromium-molybdenum alloys (e.g., UNS: R30003 such as ELGILOY®, PHYNOX®, and the like), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035 such as MP35-N® and the like), nitinol, and the like, and others.
Some examples of suitable polymers for devices 100, 1000 or any of the baskets disclosed herein may include polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, for example, DELRIN® available from DuPont), polyether block ester, polyurethane (for example, Polyurethane 85A), polypropylene (PP), polyvinylchloride (PVC), polyether-ester (for example, ARNITEL® available from DSM Engineering Plastics), ether or ester based copolymers (for example, butylene/poly(alkylene ether) phthalate and/or other polyester elastomers such as HYTREL® available from DuPont), polyamide (for example, DURETHAN® available from Bayer or CRISTAMID® available from Elf Atochem), elastomeric polyamides, block polyamide/ethers, polyether block amide (PEBA, for example available under the trade name PEBAX®), ethylene vinyl acetate copolymers (EVA), silicones, polyethylene (PE), Marlex high-density polyethylene, Marlex low-density polyethylene, linear low density polyethylene (for example REXELL®), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), poly paraphenylene terephthalamide (for example, KEVLAR®), polysulfone, nylon, nylon-12 (such as GRILAMID® available from EMS American Grilon), perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefin, polystyrene, epoxy, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (for example, SIBS and/or SIBS 50A), polycarbonates, ionomers, biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers thereof, polymer/metal composites, and the like.
Those skilled in the art will recognize that the present disclosed subject matter may be manifested in a variety of forms other than the specific embodiments described and contemplated herein. Accordingly, departure in form and detail may be made without departing from the scope and spirit of the present disclosure as described in the appended claims.
This application claims priority under 35 U.S.C. §119 to U.S. Provisional Application Ser. No. 61/890,687, filed Oct. 14, 2013 and to U.S. Provisional Application Ser. No. 61/890,711, filed Oct. 14, 2013, the entireties of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61890687 | Oct 2013 | US | |
| 61890711 | Oct 2013 | US |
