Patent ID: 12213900

This disclosure makes use of examples to demonstrate various inventive aspects. The concepts presented in connection with a particular embodiment can be employed together with any other aspects presented in connection with the different embodiments. Thus, the presentation of the embodiments should be understood as demonstrating a number of open ended combinable options and not restricted embodiments. Changes can be made in form and detail to the various embodiments and features without departing from the spirit and scope of the invention.

DETAILED DESCRIPTION OF THE INVENTION

This disclosure generally relates to catheters and implantable devices that undergo movement cycles within a patient. The cycles can include expansion and contraction phases. During the expansion phase, catheters and implantable devices may expand to have a larger profile. During the contraction phase, the catheters and implantable devices may contract to have a smaller profile. The catheters and implantable devices may expand to have profiles larger or contract to have smaller profiles than when the catheters and implantable devices were first introduced into the body, previous to the expansion phase, and/or following the contraction phase. These and other aspects will be discussed and shown in connection with the following embodiments. It is noted that the embodiments are presented to demonstrate various inventive aspects. For the sake of clarity and practicality, all possible combinations of the various aspects are not presented herein as separate embodiments. Aspects of one embodiment can be combined and/or modified with those of a different embodiment. As such, the inventive scope of this disclosure is not limited to the particular embodiments disclosed.

FIG.1shows a schematic view of a medical device1. The medical device1includes a catheter2that is percutaneously insertable into a patient. For example, the catheter2can be inserted into a vessel or other pathway of the patient. Examples of pathways include the circulation system (e.g., veins, arteries, and/or heart, such as via the femoral artery), the respiratory system (nasal, trachea, larynx and bronchia, such as via the mouth), the digestive system (e.g., mouth, throat, esophagus, stomach, intestines, colon, anus, kidneys, bladder, urethra and various ducts, such as via the mouth, urethra, or anus), amongst others.

The catheter2includes a proximal section3, a distal section5, and an intermediate section4that is located between the proximal section3and the distal section5. In various embodiments, the catheter2is a tube or other elongated flexible body that extends from the proximal section3to the distal section5. At least in the form of a tube, the catheter2can be a round body. Round, as used herein, includes generally circular and elliptical profiles which need not be perfectly circular or elliptical. The tube or other elongated flexible body can be formed from polymer material, such as polyurethane, nylon, polyethylene terephthalate, polyether block amide, and/or silicone, amongst others. The catheter2may additionally or alternatively be formed from a metal such as, for example, a nickel-titanium alloy (i.e. Nitinol).

The medical device1is shown to include a handle6. The proximal section3of the catheter2is connected to the handle6. The handle6is sized to remain outside of the patient. The handle6includes a plurality of ports8. The ports8can be in fluid communication with one or more lumens of the catheter2. For example, the catheter2can include one or more internal lumens that extend the full length of the catheter2to connect with one or more of the ports8, to allow passage of an elongated device (e.g., a guide wire) and/or fluids (drugs, contrast dye, etc.) through the catheter2and past its distal section5.

The handle6includes a user input7. User input7can include one or more buttons that are electrically connected to control circuitry (discussed later herein) housed within the handle6and/or connected to the handle6. Such control circuitry can include a power source (e.g., a battery) and a circuit for generating one or more electrical signals based on user input (e.g., from the user input7) to cause a portion of the catheter to expand and contract.

FIG.2Ashows an enlarged schematic view of the distal section5of the catheter2. As shown, at least part of the distal section5of the catheter2(and optionally the whole length of the catheter2) includes a longitudinal axis. The longitudinal axis is orientated coaxial with the distal section5of the catheter2. In other words, the longitudinal axis is orientated along at least part of the catheter2to extend through a radial center of the catheter2. The distal section5includes a lumen15, which as discussed previously can extend the full length of the catheter2. The lumen15can be coaxial with the indicated longitudinal axis.

FIG.2Bshows the same view asFIG.2Aexcept that part of the distal section5has radially expanded relative to the state shown inFIG.2A. Radial expansion, as used herein, refers to movement laterally outward from a radial center. The radial center may be at the longitudinal axis of the catheter or implantable device. Radial contraction, as used herein, refers to movement laterally inward toward the radial center. The lateral direction of expansion or contraction can be orthogonal to the longitudinal axis of the catheter or implantable device. While the order ofFIGS.2A-Band2C-D show an expansion phase of a movement cycle, the same Figs. in the reverse order can represent a contraction phase of the movement cycle.

As shown inFIG.2B, a funnel has been formed from the radial expansion of the distal section5, the funnel defined by a transition in the inner diameter of the lumen15along the longitudinal axis of the distal section5. It is noted that this radial expansion is orthogonal to the longitudinal axis of the catheter2. While inFIG.2A, the lumen15has a consistent inner diameter along the full length of the catheter2(or at least along the distal section5), the lumen15is larger distally and narrows proximally along the distal section5in the state shown inFIG.2B. In this way, a circumferential inner surface of the catheter2that defines the inner lumen15is sloped inwardly in the proximal direction to form an inner funnel.

FIG.2Cis a cross sectional view taken along plane AA ofFIG.2AwhileFIG.2Dis a cross sectional view taken along the same plane AA ofFIG.2B.FIGS.2C-Dshow one option for how radial expansion and/or contraction can be carried out. As shown inFIGS.2C and2D, the catheter2is formed from catheter body material17. The catheter body material17can be a polymeric material (e.g., any material referenced herein) formed into the tube shape shown inFIGS.2A-D. The catheter202can be a round body. The distal section5includes compliant material18. Compliant material18can be a polymeric material (e.g., any material referenced herein), and in some embodiments is a different type of polymeric material as the catheter body material17. In some other embodiments, the compliant material18can be the same type of material as the catheter body material17. In some embodiments, the compliant material18is more flexible (e.g., has a lower durometer and/or lower elastic modulus) than the catheter body material17. In some embodiments, the compliant material18can be silicone while the catheter body material17can be a stiffer polymer such as polyurethane, nylon, or PEBAX. The compliant material18can be heat bonded, sonically welded, or adhered (e.g., with epoxy) to the catheter body material17. Each of the catheter body material17and the compliant material18form a body.

The radial expansion of the catheter2is caused by expansion of the radially adjustable structure10. The radially adjustable structure10is in the shape of a ring in the embodiment shown. As further discussed herein, the radially adjustable structure10increases in diameter between the states ofFIGS.2C-Dto force the body of the catheter2along the distal section5to expand in inner diameter, outer diameter, and circumference.

The radially adjustable structure10is in the shape of an annular body which, as referenced herein, can have a circular or ovular profile while not necessarily being perfectly circular, ovular, or otherwise uniform in circumferential profile. As shown, the radially adjustable structure10is located at the distal section5of the catheter2. The radially adjustable structure10is distal and remote from the proximal section3as well as the intermediate section4of the catheter2. During assembly, the compliant material18can be placed around the radially adjustable structure10and then the compliant material18can be attached to the catheter body material17. The radially adjustable structure10is mounted on the distal section5of the catheter2. The radially adjustable structure10is embedded within the distal section5of the catheter2in the illustrated embodiment. More specifically, the radially adjustable structure10is contained within the material of the catheter2(e.g., the compliant material18and/or the catheter body material17) such that the expansion contraction element10does not have a surface that is exposed (e.g., exposed to body tissue) outside of the catheter2. In some embodiments, the radially adjustable structure10may be neither exposed on an outer surface that defines an outer circumference of the catheter2nor on an inner surface that defines the inner lumen15. However, in various other embodiments, the radially adjustable structure10can be exposed, such as one or both of on the outer surface that defines the outer circumference of the catheter2and the inner surface that defines the inner lumen15. For example, the radially adjustable structure10can be located around the exterior of the catheter body material17or entirely inside the lumen15. As shown inFIGS.2C-D, the radially adjustable structure10is coaxial with the catheter2, particularly with respect to the longitudinal axis.

The radially adjustable structure10is electrically connected to control circuitry (e.g., located in the handle6) by conductor16. The conductor16can extend from the radially adjustable structure10to the handle6to electrically connect with circuitry so as to conduct electrical signals between the circuitry and the radially adjustable structure10. The conductor16can represent a single conductor or multiple conductors supporting different electrical channels, for example. The conductor16can be formed from conductive metal (e.g., copper, MP35N, silver, and/or gold) that is stranded, braided, or coiled or taking other conductor forms. Conductors16, as well as any conductor element referenced herein, can be electrically insulated by a thin polymer coating, such as polyurethane. The conductor16can extend within a lumen defined in the catheter body material17.

FIGS.2A-5Dshow various ways in which radially adjustable structures can be incorporated into catheters and implantable medical devices. The radially adjustable structure10, as well as the medical device1, can be configured in various ways to carry out radial expansion and/or contraction. For example, the radially adjustable structure10can be configured in any way referenced herein, such in the manners shown and described in connection withFIGS.6A-17C.FIGS.18A-24show various applications for catheters and implantable medical devices having expansion and/or contraction capabilities.

FIG.3A-Bshows a perspective view of a distal section105of the catheter102at different states of a movement cycle.FIGS.3C-Dshow cross sectional views along plane BB ofFIGS.3A-B, respectively. For this disclosure, components sharing the first two digits of their reference numbers (e.g.,2,102,202,302, etc. or10,110,210,310, etc.) can have similar configurations or may even be the same embodiment amongst the various illustrated and described embodiments. For example, catheter102can be identical to catheter2except for those aspects shown or described to be different. For the sake of brevity, common aspects (e.g., materials, features, functions, properties, options, alternatives, etc.) are not repeated for different views and embodiments but can be realized in all other embodiments. In view of this disclosure being a series of examples demonstrating various interchangeable aspects and features, for all referenced embodiments, an aspect described or shown for one embodiment can be implemented in another referenced embodiment or as an alternative embodiment incorporating disparate aspects.

Returning to the embodiment ofFIGS.3A-D, a radially adjustable structure110is shown embedded within the wall of the distal section105of the catheter102. InFIG.3C, the radially adjustable structure110, which can take the form of a ring, sits within a trench formed by the catheter body material117and which that extends entirely around the circumference of the catheter body material117. Encircling this trench and the radially adjustable structure110is a layer of compliant material118. The radially adjustable structure110is electrically connected to a conductor116. The compliant material118may be attached to the catheter body material117at the distal and proximal ends of the compliant material118but not directly attach to the catheter body material117in the middle portion of the compliant material118that is directly over the radially adjustable structure110.

The radially adjustable structure110increases in diameter between the states ofFIGS.3C-Dto force the body of the catheter102along the distal section105to expand in outer diameter and circumference. The distal section105is shown to expand at an expansion/contraction portion of the catheter102inFIGS.3B and3D. As compared to the embodiment ofFIGS.2A-D, a funnel is not formed by the expansion at the distal opening of the catheter102and the outer diameter of the catheter102that is distal to the expansion/contraction portion (e.g., to the distal tip of the catheter102) is consistent and does not change due to the expansion. Rather, a bulb is formed along an intermediary portion of the distal section105of the catheter102. Additionally or alternatively, a bulb could be formed along an intermediate section (e.g., corresponding to intermediate section4of the embodiment ofFIG.1) of the catheter102depending on the location of the radially adjustable structure110. The radial expansion increases the outer diameter and circumference of the catheter102. As shown inFIG.3D, the inner diameter of the inner lumen115is not increased by the expansion of the radially adjustable structure110. However in some other embodiments, the inner diameter of the inner lumen115along this expansion/contraction portion is increased by the expansion of the radially adjustable structure110in similar manner to the increase in the inner diameter of the lumen15as shown inFIGS.2C-D. The increase in outer diameter without an increase in the inner diameter of the catheter102, as shown inFIG.3D, can be due to the use of a more flexible material for the compliant material118than the catheter body material117and/or by not anchoring the radially adjustable structure110to the catheter body material117so that the radially adjustable structure110can expand independently of the catheter body material117. While the order ofFIGS.3A-Band3D-C shows an expansion phase of a movement cycle, it will be understood that the same Figs. in the reverse order can represent a contraction phase of the movement cycle.

The embodiment ofFIG.4A-Cshows multiple radially adjustable structures210A-B.FIGS.4A-Cshow catheter body material217including multiple trenches in which a first radially adjustable structure210A and a second radially adjustable structure210B can be seated. The first radially adjustable structure210A is located wholly distally with respect to the second radially adjustable structure210B while the second radially adjustable structure210B is located wholly proximally with respect to the first radially adjustable structure210A. Both of the first and second radially adjustable structures210A-B are covered by a layer of compliant material218. Both of the first and second radially adjustable structures210A-B may alternatively be covered by a layer of the catheter body material217instead of the layer of compliant material218. As shown inFIGS.4B-C, both of the first and second radially adjustable structures210A-B can expand at the same time to increase the outer diameter of the catheter202.

Both of the radially adjustable structures210A-B can be independently controllable with respect to each other, such that each can be expanded or contracted from the same first diameter (or different initial diameters) to different secondary sizes at the same time. As shown inFIG.4C, the first and second radially adjustable structures210A-B are expand to different diameters such that the first radially adjustable structure210A is expanded to have a larger outer diameter than the second radially adjustable structure210B. This forces the body of the catheter202to have different outer diameters along different longitudinal sections of the catheter202at which the radially adjustable structures210A-B are respectively located. While the order ofFIGS.4A-Bshows an expansion phase of a movement cycle, it will be understood that the same Figs. in the reverse order can represent a contraction phase of the movement cycle.

FIGS.5A-Bshow a perspective view of a distal section305of the catheter302.FIG.5Cshows a front end view of a distal section305of the catheter302as expanded.FIGS.5D-Eshow cross sectional views along plane CC ofFIGS.3A-B, respectively. While the order ofFIGS.5A-Band5D-E show an expansion phase of a movement cycle, it will be understood that the same Figs. in the reverse order can represent a contraction phase of the movement cycle.

A radially adjustable structure310is embedded within the distal section305of the catheter302. The radially adjustable structure310can be similar to any of that disclosed herein, but the radial expansion profile is different from the previous embodiments. The previous embodiments generally expand evenly around the longitudinal axis of the catheter. InFIGS.5A-E, the expansion is greater on one lateral side of the catheter302than another side. This asymmetry of expansion is achieved by providing stiffer catheter body material317around a portion of the radially adjustable structure (e.g., the top side as shown inFIG.5D) while a more compliant material318is provided along one or more other sides (e.g., the bottom side as shown inFIG.5D). In expanding, the radially adjustable structure310may tend to radially expand in the direction of least resistance, which is towards the lower modulus compliant material318instead of the stiffer catheter body material317. While different types of materials are used in this embodiment to control the direction of radial expansion, in other embodiments, the same material can be used entirely around an expansion/contraction structure but the walls of the material can be thinner along a first circumferential section (fostering greater radial expansion and/or contraction there-along) and thicker in a second circumferential section (fostering lesser radial expansion and/or contraction there-along).

FIGS.6A-Dshow a radially adjustable structure410. The radially adjustable structure410can correspond with any radially adjustable structure referenced herein, such as for use in the embodiments ofFIGS.2A-5E and18A-24.FIG.6Ashows a perspective view of a radially adjustable structure410.FIG.6Bshows a front view of the radially adjustable structure410in the same state as inFIG.6A. The radially adjustable structure410is in a relatively small or contracted state inFIG.6A-B.FIGS.6C-Dshows the same views as inFIGS.6A-B, respectively, of the radially adjustable structure410except that the radially adjustable structure410is in a relatively larger or expanded state inFIGS.6C-D. While the order ofFIGS.6A-Band6C-D show an expansion phase of a movement cycle, it will be understood that the same Figs. in the reverse order can represent a contraction phase of the movement cycle.

The radially adjustable structure410comprises a strip421rolled into a ring. The ring is round. The strip421is coiled upon itself to form multiple layers. At least some of the layers radially overlap each other. For example, in the smaller state ofFIGS.4A-B, all layers radially overlap each other while in the larger state ofFIGS.4C-D, there is a single layer about a circumferential portion of the radially adjustable structure410. The change in the number of layers corresponds to the change in diameter of the radially adjustable structure410as during the movement cycle the layers are caused to slide relative to each other (e.g., a layer can slide clockwise or counter clockwise relative to an adjacent layer) to increase or decrease the circumference of the radially adjustable structure410which changes the diameter.

The strip421has two opposite ends of its long axis (shown inFIGS.9A-C). When rolled into the radially adjustable structure410, the two ends are free with respect to each other such that the ends of the strip421can move (e.g., slide) relative to one another. The strip421is resistant to collapsing due to being coiled into a tubular shape. The coiling of a strip421has the added benefit that the strip421can be expanded and contracted while maintaining a lumen413.

The strip421can be ribbon. The strip421can be formed from metal, such as stainless steel, aluminum, and/or Nitinol (i.e. a nickel titanium alloy), or other metal element or alloy. In some embodiments the strip421can be formed from a polymeric material, preferably stiff, such as high density polyethylene and polyamide, amongst other options. The strip421can include a first surface414. The first surface414can define an outer surface, outer circumference, and outer diameter411of the radially adjustable structure410as shown inFIGS.6B and6D. The strip421includes a lumen413having an inner diameter412. The strip421can include a second surface419. The second surface419can define an inner surface, lumen413, inner circumference, and inner diameter412of the radially adjustable structure410.

The strip421is wrapped around itself in multiple layers including a first layer437and a second layer438. The first layer437is radially outward from, but in contact with, the second layer438. As shown by comparingFIGS.6A-BtoFIGS.6C-D, respectively, the layers of the strip421can slide relative to each other (e.g., in clockwise and counter clockwise orientations about a radial center) to expand (going fromFIGS.6A-BtoFIGS.6C-D) and contract (going from FIGS.6C-D toFIGS.6A-B) the radially adjustable structure410. For example,FIGS.6A-Bshow three overlapping layers along a portion of the radially adjustable structure410and two overlapping layers elsewhere. InFIGS.6C-D, the radially adjustable structure410is expanded to include only a single layer of the strip421around much of the circumference of the radially adjustable structure410yet the first layer437of the strip421still overlaps with the second layer438of the strip421over a portion about the circumference of the radially adjustable structure410. In some embodiments, the radially adjustable structure410may always have multiple overlapping layers of the strip421about the entire circumference of the radially adjustable structure410in both expanded and contracted states such that there is no circumferential portion along which the radially adjustable structure410is formed by only a single layer of the strip421.

The radially adjustable structure410can be part of a catheter, implantable device, or other device, such as any device referenced herein. Therein, the radially adjustable structure410can have a proximal terminus and a distal terminus and a length therebetween. The length of the radially adjustable structure410can be orientated along the longitudinal axis of the catheter, implantable device, or other device. In some embodiments, the length of the radially adjustable structure410is in the range of 0.5 centimeters to 3 centimeters, or in the range of 2 millimeters to 20 millimeters, although smaller and larger lengths may be utilized depending on the application.

In coiling the strip421into the radially adjustable structure410shown, the strip421can be strained in the manner of a spring, such that the strip421is mechanically biased to expand and uncoil (and in some cases, biased to lay flat as shown inFIGS.9A-C). As such, the transition from the smaller outer diameter411and inner diameter412inFIGS.6A-Bto the larger outer diameter411and inner diameter412inFIGS.6C-Dcan represent a lessening degree of strain in the spring (e.g., relaxation with less stored energy). A transition from the larger outer diameter411and inner diameter412inFIGS.6C-Dto the smaller outer diameter411and inner diameter412inFIGS.6A-Bcan represent a straining of the spring and an increase in potential energy built up in the radially adjustable structure410. As discussed further herein, a motor can drive the radially adjustable structure410from this larger state inFIGS.6C-Ddown to the smaller state inFIGS.6A-B, whereas merely releasing one or more mechanical restraints on the rolled strip421allows the radially adjustable structure410to release stress in transitioning from the smaller state inFIG.7A-bto the larger state inFIG.7C-D. In some embodiments the strip421is coiled and set so that it is more relaxed in a smaller state and is strained when expanded to have a larger state.

A bracket420(further shown inFIGS.8A-B) accepts two layers of the coiled strip421within itself. Specifically, the bracket420accepts the first layer437and the second layer438within a space defined within the bracket420. The bracket420can be rigidly attached to the first layer437formed by one end of the strip421, such as by welding or riveting. In various embodiments, the bracket420is rigidly attached to the outer most layer of the strip421as coiled, which in the embodiment ofFIGS.6A-Dis the first layer437, and may be attached at or near the end of the strip421. The bracket420serves to press the first and second layers437,438(or other layers) close to or against one another to maintain the proximity of adjacent layers which helps facilitate forcing the layers to slide relative to one another. Conductor416can be supported by the bracket420and electrically connects control circuitry to one or more motors that act upon the coiled strip421to move the layers relative to one another and drive the expansion and contraction shown inFIGS.6A-D, as further discussed herein. The bracket420being attached to the outermost layer of the coiled strip421, and the second outermost layer of the strip421being threaded through the space in the bracket420, prevents the outermost layer from peeling off and away from the rest of the layers. The innermost layer may not need to be secured because it is biased outwardly and thus may tend to stay close to the second inner most layer of the strip421. The bracket420may function as a buckle through which the strip421is threaded and which holds the layers and/or ends of the strip421together.

As shown, the bracket420is positioned against or along the outer first surface414but is not against or along the inner second surface419inFIGS.4A-D. As shown, the bracket420is wrapped around two adjacent layers of the strip421such that the bracket420is positioned against at least one of the inner circumference and the outer circumference of the ring (just the outer circumference inFIGS.4A-Bbut both of the inner and outer circumferences inFIGS.4C-D). As shown, the bracket421is located on a first section of the outer circumference of the coiled strip421but is not located on a second section of the outer circumference of the coiled strip421, and the second section is longer than the first section.

It is noted that the illustrated strip421embodiment is coiled such that each outer layer aligns proximally and distally with the layer beneath it and does not extend proximally or distally of the layers beneath or above it. As such, the innermost layer extends distally and proximally to the same extent as the outermost layer, and vice versa, and this holds true for each successive layer. For at least this reason, the strip421does not take the shape of a helix. It is noted that despite radial expansion and contraction, the length of the strip421along the longitudinal axis did not change. Whether in an expanded or contracted state, the radially adjustable structure410does not extend any more distally or proximally as compared to any other expanded or contracted state. Thus, when placed in a catheter body, implantable device, or other medical device, the radially adjustable structure410can radially expand and contract without expanding and contracting along the longitudinal axis of the catheter. However, not all embodiments are so limited as to not expand longitudinally.

FIG.7A-Dillustrates an alternative configuration for a strip521coiled into a ring having a dynamic diameter. Specifically, while the bracket420in the configuration ofFIGS.6A-Dis attached to the outermost layer of the coiled strip421and is located along the first surface414(as least in the smaller state ofFIGS.6A-B), the bracket520in the configuration ofFIGS.7A-Dis instead attached to the innermost layer539and end of the coiled strip521. In this configuration, the strip521is mechanically biased to coil up in a small ring. The lowest potential energy state of the coiled strip521is when the outer diameter511and the inner diameter512are relatively small and there is greater potential energy wound into the spring when the strip521is caused to expand to have a greater outer diameter511and inner diameter512. The bracket520, being attached (e.g., by welding or riveting) to the innermost layer539and end of the coiled strip521, and the second most inner layer545being threaded through a space within the bracket520, maintains the patency of the lumen513by the end of the inner most layer539of the strip521not peeling away into the center of the lumen513. The end of the outermost layer of the strip521may not need to be secured because it is biased inward and therefore not inclined to separate from the other layers. A conductor516can extend through the bracket520or otherwise connect with electrical components on the strip521. The strip521can include a first surface514that defines an outer surface and outer diameter511of the annular body510. The strip521can include a second surface519that defines an inner surface, lumen513, and inner diameter512of the annular body510. As shown, the bracket520is positioned against or along the second surface519but is not against or along the first surface514.

It is noted that while a single bracket is shown on the coiled strip in the embodiments ofFIGS.6-7, two or more brackets can be provided on a coiled strip. For example, two brackets can be attached to the opposite ends of the strip, respectively. The two brackets can be attached to the inner most and outer most layers of the strip to be on the inner and outer surfaces of the ring as shown (separately) inFIGS.6A-7D. Additionally or alternatively, multiple brackets (e.g., two, three, four, etc.) can be attached to the same layer (e.g., innermost or outermost) to lengthen the distance along the strip along which the layers are forced against one another.

FIG.8Ashows a perspective view of a bracket620. The bracket620can correspond to any bracket referenced herein, such as bracket420or520. The bracket includes a top portion622and a bottom portion623and a space624defined between the top portion622and the bottom portion623. Side portions at opposite ends connect the top portion622to the bottom portion623. An aperture643through a side portion allows one or more conductors to be routed from outside the bracket620to inside the bracket620to connect with any electrical elements on the strip or within the space624, such as a motor. It is within the space624, and between the top portion622and the bottom portion623, that the two (or other number) of adjacent layers of the strip (any strip referenced herein, such as strips421,521) are located to help the strip maintain the annular shape (e.g., as inFIGS.6A-7D). These two layers can be the two outer most layers or the two inner most layers of the annular body, depending on the bias of the strip (e.g., biased to flatten or curl). Moreover, one or more motors can be located between the top portion622and the bottom portion623to drive the movement cycles.

Either of the top portion622or the bottom portion623of the bracket620, depending on which is outermost or innermost and the bias of the strip621, can be attached (e.g., welded, riveted, or glued with epoxy) to the strip. For example, if the bracket620accepts the two outermost layers of the strip (e.g., inFIGS.6A-D), then the top portion622can be orientated radially outward from the strip (and the bottom portion623), and the top portion622can be attached to an exterior surface (e.g., the first surface414ofFIGS.6A-D) of the outermost layer of the strip. If the bracket620accepts the two innermost layers of the strip (e.g., inFIGS.7A-D), then the bottom portion623can be orientated radially inward from the strip (and the top portion622) and the bottom portion623can be attached to the radial center-facing surface (e.g., the second surface519ofFIGS.7A-D) of the innermost layer of the strip.

The bracket620can be formed from metal (e.g., stainless steel, Nitinol) or a polymer (e.g., a relatively stiff polymer such as high-density polyethylene).FIG.8Bshows a front view of the bracket620.FIG.8Balso shows a bias element629which extends across the space624. The bias element629can have a spring force such that when the layers of the strip are placed within the space624, the bias element629presses against one of the layers to maintain contact or proximity between the layers. As discussed further, maintaining proximity between the layers allows one or more motors to move the layers of the strip relative to one another.

FIGS.9A-Bshow top and bottom views of the broad sides of a strip721in a completely uncoiled state (i.e. flat).FIG.9Cshows a cross sectional view along line DD ofFIG.9A. The strip721can correspond to any strip referenced herein, such as strips421or521. In some configurations,FIG.9Amay show the radially inwardly facing bottom side of the strip721(e.g., the second side419ofFIGS.6A-D) that faces the lumen of the ring formed by the coiling of the strip721. Likewise,FIG.9Bmay show the radially outwardly facing top side of the strip721(e.g., the first side414ofFIGS.6A-D) that faces away from the lumen of the ring formed by the coiling of the strip721. It is noted that either of these sides of the strip721and/or any other components of an annular body can be coated with a material to lower the coefficient of friction of sliding surfaces. For example, the inner and outer surfaces of the strip721can be coated with a thin layer (not illustrated) of polytetrafluoroethylene or other low friction material to decrease the friction between adjacent layers of the strip721that slide against one another during the expansion and contraction phases and/or to electrically insulate the strip721.

A plurality of motors725A-B are mounted on the bottom side of the strip721. A bracket, such as bracket420,520, or620, can be attached to the strip721near or over the motors725A-B, for example. The top portion or bottom portion of the bracket can be attached to either of the broadside surfaces of the strip721shown inFIGS.9A-B, such as by welding, riveting, or adhesive (e.g., epoxy). Each of the motors725A-B is partially housed within a constraint726. The topside of the strip721, as shown inFIG.9B, includes a trench727. The inside of the trench727is a textured surface728. In particular,FIG.9Cshows that the trench727is located on one side of the strip721while the motor725B is mounted on the opposite side of the strip721. As also shown, the constraint726surrounds the motor725B on three sides while a fourth side of the motor725B faces, and contacts, the strip721. When the strip721is coiled, the motors725A-B and the constraint726can partially or fully reside within the trench727. In this way, the motors725A-B and/or constraint726can be a projection feature on one side of the strip721while the trench727can be a groove on a second side of the strip721opposite the first side. This projection feature can be received within the groove and move within the groove as the layers of the strip721, when coiled into a ring, slide relative to one another. It is noted that various alternative strip embodiments mat not have a trench and/or texture.

The strips721includes a first end747that is opposite the second end748(the ends representing the poles of the long axis of the strip721). The first end747can define at least part of the inner most or outer most layer of a ring while the second end748can define at least part of the other of the inner most or outer most layer of a ring. As shown, the motors725A-B are located at the first end747but not at the second end748. A bracket, examples of which are shown and discussed herein, can be attached to the strip747at the first end747and not at the second end748, in some embodiments.

The motor725B can move within the constraint726, but the constraint726keeps the motor725B against or at least close to the strip721. The constraint726can be formed from a metal (e.g., stainless steel, Nitinol) or polymer. The constraint726can be welded, glued, and/or riveted to the strip721, preferably around the periphery of the motor725B to allow the motor725B enough clearance from the constraint726to move within the constraint726. In some embodiments, the constraint726can be understood as a pocket inside of which the motor725B resides but within which the motor725B can move and out of which the motor725bcan extend and elongate when electrically activated. It is noted that the motor725B can brace itself against the constraint726(e.g., the bottom of the constraint726in particular) so that the motor725B can apply a force outside of the constraint726(opposite of the surface against which the motor725B is braced) when activated. While motor725B is described in connection with the constraint726, any motor referenced herein can similarly be contained and braced by a similar constraint.

Returning to the view ofFIG.9A, it is noted that each of the motors725A-B extends beyond the respective constraint726in which the motor is partially housed. Each motor725A-B expands and contracts within the constraint726to extend a corresponding greater and lesser degree beyond the constraint726. The electrical conductors716electrically connect the anode and cathode terminals of the motors725A-B to provide controlling signals.

While a plurality of motors725A-B are shown in the embodiment ofFIGS.9A-B, it will be understood that a single motor or a greater number of motors (e.g., three, four, five, ten, etc.) can alternatively be used. The motors725A-B are serially arrayed along the length (as opposed to the width) of the strip721as shown unrolled. It is noted that various alternative arrangements of motors are shown elsewhere herein.

FIG.10Ashows a perspective view of a motor825.FIG.10Bshows a cross sectional view along line FF of the motor825ofFIG.10A.FIG.10Cshows one end of the motor825whileFIG.11Dshows the opposite end of the motor825. The motor825can correspond to any motor referenced herein, such as for example motors725A-B.

The motor825operates by piezoelectric action whereby an electrical signal applied across the first terminal831and the second terminal832of the motor825generates an electric field across piezoelectric material830. The first terminal831includes a first conductive coating835that can extend along a full side (e.g., a top side) of the piezoelectric material830. The second terminal832includes a second conductive coating836that can extend along a full side (e.g., a bottom side) of the piezoelectric material830. The first and second conductive coatings835,836can be formed from a metal, such as gold, copper, or other conductive material, such as conductive epoxy. The opposite major broadsides of the motor825are insulated by a first insulative coating833and a second insulative coating834. The first insulative coating833and the second insulative coating834can be formed from a polymer, such as polyamide.

Piezoelectric materials can include aluminum nitride, barium titanate, gallium phosphate, lanthanum gallium silicate, polyvinylidene fluoride, and lead zirconate titanate, amongst other options. The piezoelectric material830includes an elongation/contraction axis along which the piezoelectric material830expands or contracts when electrically activated. As indicted, the elongation/contraction axis is orientated along the longitudinal dimension of the rectangular motor825to maximize the amount of expansion along this axis. The piezoelectric material830has a crystalline structure which causes the piezoelectric material830to change dimension. The cells of the crystalline structure function as a dipole due to a charge imbalance. During manufacturing, the piezoelectric material830is “polled” by application of a very strong electric field across the piezoelectric material830that orientates the dipoles of the cells in a particular direction (e.g., in the direction of the indicated expansion/contraction axis). Removal of the very strong electric field causes some relaxation of the dipole orientation, but during use of the piezoelectric material830, subsequent application of a less strong signal causes the dipoles to reorientate along the poling direction and/or to cause the dipoles to more precisely align along the poling direction. The dipole reorientation changes the length of the piezoelectric material830most dramatically in the dipole direction. In the embodiment ofFIGS.10A-D, the dipole direction can be parallel with the indicated expansion/contraction axis, such that the motor825expands and contracts along this axis in response to a signal being applied across the first and second terminals831,832. The piezoelectric material830may expand and contract in other dimensions/directions upon electrical activation, but such expansion and contraction will be of a much smaller ratio than along its elongation/contraction axis.

The controller840can be located, for example, within the handle7in the embodiment ofFIG.1. The controller840can include a power source841(e.g., a battery), an input842(e.g., buttons or otherwise corresponding to input7of the embodiment ofFIG.1), and/or a processor843. The controller840manages output of control signals to the motor(s) in response to received input to control the motor825. Multiple conductors816can extend from the controller840to the first terminal831and the second terminal832to electrically connect with the first conductive coat835and the second conductive coat836, respectively. The first conductive coat835and the second conductive coat836can create an electric field between the first conductive coat835and the second conductive coat836to activate the piezoelectric material830located between the first conductive coat835and the second conductive coat836. While one layer of piezoelectric material830is shown in the motor825, various other embodiments can have multiple layers of piezoelectric material that are sandwiched between the first conductive coat835and the second conductive coat836. While the first and second terminals831,832are shown as being on opposite longitudinal ends of the motor825to allow the conductors816to deliver a differential signal across the piezoelectric material830, one or both of the first and second terminals831,832may alternatively be provided on one or both of the major broad sides of the motor825. For example, a first window can be provided through the first insulative coating833to provide access to the first conductor layer835while a second window can be provided through the second insulative coating834to provide access to the second conductor layer836for the conductors816. Regardless of the locations of the first and second terminals831,832, a coating of material (e.g., a polymer such as polyurethane) may be provided on the ends of the motor825to allow the motor825to engage and push off of other components as further discussed herein.

FIGS.11A-Jdemonstrate various options for how a motor can move layers of a strip (e.g., any strip referenced herein, coiled for example in the manner ofFIGS.6A-7D, or any other radially adjustable structure) relative to one other to expand and/or contract the radially adjustable structure formed by the strip. For example,FIGS.11A-Jcan correspond to the radially adjustable structure410ofFIGS.6A-D. Also,FIGS.11A-Ecan represent a cross sectional view of line EE ofFIG.9AwhileFIGS.11F-Jcan represent the cross sectional view along line FF ofFIG.9Awhen the strip721is coiled into a ring, but the aspects demonstrated inFIGS.11A-Jare not limited to this embodiment and accordingly can be applied to any aspect or embodiment of a radially adjustable structure. The series ofFIGS.11A-Jcan represent the states, during expansion and contraction phases, of different motors (e.g., motors725A, B) positioned at different locations on a coiled strip. Each ofFIGS.11A-Ecan correspond in time to each ofFIGS.11F-J, respectively. For example,FIGS.11A and11Frepresent different motors at the same point in time, andFIGS.11B and11Grepresent these different motors at another common point in time, etc. The two motors925A-B are activated to drive the movement cycle of an annular body. Conductors, and well as other components, are omitted from the views of11A-J for clarity.

Each ofFIGS.11A-11Jinclude a first layer937and a second layer938, which can represent an outermost layer and a second outermost layer (or inner most and second innermost layers), respectively of a coiled strip. One or more brackets (e.g., any bracket referenced herein) can be disposed directly over, or close to, the motors925A-B to urge the first layer937and the second layer938close to or against one another to help engagement of the parts, including the motors925A-B that are sandwiched between the first layer937and the second layer938. Either or both of the motors925A-B may be at least partially within the space of the bracket when the bracket is directly over the motor. In some embodiments, the motors925A-B are mounted on the bracket and layer937represents part of the bracket while layer938represents the outermost or inner most layer of a coiled strip.

The texturing928is shown on the side of the second layer938that faces the first layer937. As shown in this embodiment, the texturing938includes a series of projections. The texturing938can be a series of evenly spaced bumps (e.g., in a pattern resembling a sine wave). The projections can serve as push-off or bracing features for the motors925A-B. It will be understood that not all embodiments may include such texturing. For example, the surface of the second layer938may be flat or otherwise smooth. The constraints926are shown as maintaining the position of the motors925A-B to hold the motors925A-B against or close to the first layer937. For reasons that will be demonstrated, motor925A can be referred to as a “pusher motor” while motor925B can be referred to as a “bracing motor.”

The first layer937includes projections939A-B underneath each of the exposed ends of the motors925A-B (the exposed ends of the motors925A-B being those parts of the motors that extend beyond the constraints926). The projections939A-B can bias the motors925A-B to engage the opposite second layer938. It will be understood that the projections939A-B are optional and may not be used in all embodiments. For example, the motors925A-B can rest in an orientated that points the motors925A-B at the opposite layer938.

As shown inFIG.11F, the motor925B is engaged with one of the projections of the texture928of the second layer938. It is noted that the coiled strip may be biased such that the second layer938is biased to move leftward (in the orientation of the view ofFIG.11A) relative to the first layer937. However, the engagement of the motor925B with the projection of the texture928of the second layer938prevents the second layer938from moving leftward relative to the first layer937. In this manner, the motor925B is serving as a bracing motor in that it maintains the relative positions of the layers937,938of the strip whereby the mechanical bias of the coiled strip would otherwise move layers937,938relative to one another and to a state having less or no stored spring energy (e.g., relaxing by uncoiling). It is noted that the constraints926can be, for example, attached to the first layer937to anchor a substantial portion of each of the motors925A-B to the first layer937, the motors925A-B only being movable to extend rightward from the constraints926(e.g., upon electrical activation) to be exposed for engagement with the second layer938, amongst other options.

FIGS.11B and11Gshow that motor925A has been electrically activated and is expanding in length to engage and push a projection of the texture928of the second layer938. As indicated by arrows, this moves the second layer938rightward (e.g., clockwise) with respect to the first layer937. As previously mentioned, the coiled strip is biased such that the second layer938would tend to move leftward of the first layer937therefore, the activation of the motor925pushing the second layer938to the right with respect to the first layer937is overcoming the mechanical bias of the coiled strip421to wind (or further coil) the strip, in the manner of a spring, to store more energy in the coiled strip while also expanding (or alternatively contracting) the annular body formed by the strip. It is noted that the motor925B is orientated to have a directional orientation that permits texture928to slide in one direction over the motor925B but the motor925B engages the texture928to block motion if the second layer938slides in the opposite direction, as shown inFIG.11H.

FIGS.11C and11Hshow that motor925A has been electrically deactivated and is contracting in length to disengage from the previously-pushed projection of the texture928of the second layer938.FIGS.11D and11Ishow that motor925A has been restored to the same position, relative to the constraint926and the first layer937, as inFIGS.11A and11F. While the disengagement of the motor925A from the projection would otherwise allow the coiled strip to relax and the layers937,938to slide relative to one another to release stored energy, the bracing motor925B is positioned to engage one of the projections of the texture928of the second layer938. As such, the pushing motor925A activates to incrementally slide the first and second layers937,938relative to one another while the bracing motor925B maintains at least some progress of each increment of the pushing motor925A for each cycle. The expansion and contraction cycle of the motors925A-B shown inFIGS.11A-Dand11F-I can be repeated (e.g., thousands of times) for each expansion or contraction cycle of a radially adjustable structure. As such, the diameter of an annular body formed by a coiled strip can be incrementally and progressively expanded or contracted by repeated motor actuation cycles to cause one expansion or contraction phase of a movement cycle of the radially adjustable structure.

FIGS.11E and11Jshow the activation (or alternatively the deactivation) of the bracing motor925B. In some embodiments, the bracing motor925B was held in place through the states corresponding to11F-I by being electrically activated to be in an expanded state by application of an electrical signal which is then ceased in the state ofFIG.11Jto have the bracing motor925B return to its inactivated (contracted) state. Alternatively, the bracing motor925B can be of the type that contracts upon electrical activation, such that no signal is supplied to the bracing motor925B during the states ofFIGS.11A-Dand11F-I but the bracing motor925B is electrically activated for the state ofFIG.11Jto contract. The advantage of this latter option is that no energy is expended to keep the bracing motor925B in the bracing position during the reciprocation cycles of the pushing motor925A.

Contraction of the bracing motor925B inFIG.11Jdisengages the bracing motor925B from the projection of the texture928of the second layer938to allow the second layer938to freely move relative to the first layer937as the coiled strip relaxes and release stored energy. Such relaxation of the coiled strip can correspond to the annular body formed by a coiled strip returning to a previous state (e.g., having a particular inner and/or outer diameter). For example, repetition of the cycle shown inFIGS.11A-Dand11F-I can correspond to expansion of a coiled strip to the state shown inFIGS.6C-Dwhile release from bracing as shown inFIGS.11E and11Jcan correspond to contraction of the strip to the state shown inFIGS.6A-B. Alternatively, repetition of the cycle shown inFIGS.11A-Dand11F-I can correspond to contraction of a coiled strip to the state shown inFIGS.7A-Bwhile release from bracing as shown inFIGS.11E and11Jcan correspond to expansion of the strip to the state shown inFIGS.7C-D.

FIGS.11A-Jdemonstrate how layers937,938of a coiled strip can be slid relative to each other. Sliding the layers either further coils, or partially uncoils, the strip, depending on the direction of relative sliding. Further, sliding the layers relative to each other either increases the circumference of the ring or decreases the circumference of the ring, depending on the direction of sliding, and correspondingly increases or decreases the diameter of the ring.

It is noted that it may be a single motor that drives the expansion or contraction cycle, such as motor925A, while another motor or non-motor element (e.g., part of the first layer937) merely braces to maintain the incremental progress, such as motor925B or a non-moving structure similar to the projection939B that projects upward to engage the texture928and prevent motion in a particular direction between the layers937,938. For example, the projection939B may be much taller so as to engage the texture928. It is noted that some radially adjustable structures (or catheters) may have only one motor, or may lack a dedicated bracing motor, by having the motor preform both pushing and bracing. For example, the reciprocation cycle of the motor may act faster than the relaxation action of the spring of the radially adjustable structure (e.g., coiled strip) such that the motor does not need a separate motor to brace between pushing cycles because the motor shortens and elongates before the spring retracts enough to undue the incremental progress of one cycle, and the motor can remain in an elongation configuration to brace when no further expansion (or contraction, as the case may be) of the radially adjustable structure is desired. For example, the motor may cycle at a rate between 500-3,000 hertz.

FIGS.11A-Drepresent a reciprocation cycle for the pusher motor925A, each reciprocation cycle incrementally moving the first and second layers937,938relative to one another such that a plurality of reciprocation cycles add up to move the first and second layers937,938distances relative to each other greater than a single increment of a reciprocation cycle. A reciprocation cycle for a motor refers to either expansion of the motor from an initial state and then contraction back to the initial state, or contraction of the motor from an initial state and then expansion back to the initial state of the motor. Even though each incremental movement may be very small, many reciprocation cycles can be executed within a very short time. For example, motors (including piezoelectric motors) can have very high cycle times, such as 1 Hz-1 KHz. It is noted that the motors925A-B can be piezoelectric based, but can also be other types of motors, such as those further described herein. As such, moving layers relative to one another to expand an annular body is not limited to piezoelectric motors.

FIG.12Aillustrates a signal which can be applied to a motor, such as the pushing motor925A during the reciprocation cycle shown inFIG.11A-D. Continuing with this example, the letters A, B, C, D, and E correspond with the phases in time of theFIGS.11A-E, respectively. In particular, a voltage may only be applied across the pushing motor925A during a pushing phase “B”.FIG.12Cshows a different, but similar, signal that can be applied to the pushing motor925A (or any other motor) during the reciprocation cycle shown inFIG.11A-D. While square waves are shown, any types of signals can be delivered to motors, including sine, triangular and sawtooth shapes. The signals may be generated by a programmable or dedicated signal generator of controller840. Such signals can be delivered to any type of motor referenced herein.

FIG.12Bshows a signal that can be applied to a motor, such as the bracing motor925B during the reciprocation cycle shown inFIGS.11F-J. Continuing with this example, the bracing motor925B can be electrically activated to elongate during each of the phases F, G, H, I and deactivated to shorten during the J phase.FIG.12Dshows a different signal that can be applied to the bracing motor925B in which the bracing motor is not electrically activated during phases F, G, H, I but is electrically activated to contract during phase J to allow the layers to slide relative to one another as the radially adjustable structure relaxes. The difference between the signals ofFIG.12B, D is that the motor925B is activated by the signal ofFIG.12B(which in this embodiment expands upon activation) to maintain expansion in phases F-I and is only deactivated to phase J while the motor925B is activated by the signal ofFIG.12B(which in this embodiment contracts upon activation) only during phase J to contract.

FIGS.13A-Cshow different views of a strip1021, the views similar to those ofFIGS.9A-C, respectively. The embodiment ofFIGS.13A-Ccan be similar to those shown in, and/or described in connection with,FIGS.9A-C, except that the motors1025A-C are shown as arrayed across the width of the strip1021instead of serially arranged along its length as inFIGS.9A-C. As previously described, the multiple motors1025A-C can work together to alternately push and brace the strip1021to drive a radially adjustable structure through expansion and/or contraction phases. For example, motors925A, C can be pushing motors while motor925B can be a bracing motor. Alternatively, all motors925A-C can be pushing and bracing motor that operate with a fast reciprocation cycle. While three motors are shown arrayed across the width of the strip1021, a greater or lesser number of motors can be provided.

It is noted that the motors1025A-C are arrayed across the width of the strip1021while motors725A-B of the embodiment ofFIGS.9A-Care arrayed along the length of the strip721. These concepts can be combined such that a two dimensional array of motors includes X number of columns of motors (arrayed along the length of the strip) and Y number of rows (arrayed along the width of the strip). These motors can still fit partially or fully within the trench1027and engage the texture1028to function as pushing and bracing motors as described herein.

FIGS.13A-Balso illustrate tabs1046. The motors1025A-C are located at the first end1047of the strip1021while the tabs1046are located at the second end1048of the strip1021. While the tabs1046are shown on one end of the strip1021(the end opposite the end at which the motors1025A-C are located) inFIGS.13A-B, tabs1046can additionally or alternatively be added to the first end1047, such as past the motors1025A-C. The tabs1046may be formed from the same material as the strip1021or may be formed from a different type of material. The tabs1046can be wider than the bracket (e.g.,420,520,620) or at least the space (624) within the bracket such that the tabs1046engage the side walls of the bracket to prevent the end of the strip1021on which the tabs1046are placed from slipping out of the bracket. The tabs1046can be folded inward while the layers of the strip1021are threaded through the space of the bracket during assembly and then projected laterally outward, as shown, after the layers of the strip1021have been threaded through the space of the bracket. Alternatively, the tabs1046may be added only after the layers of the strip1021have been threaded through the space. The tabs1046can take different forms and/or can be provided on any other strip.

FIG.14Ashows another alternative embodiment of a strip1121in which motors1125A-E are placed inside constraints structures1126such that the first set of motors1125A-C are pointed in a first direction (e.g., by emerging from the constraints1126in the first direction) and a second set of motors1125D-F are pointed in a second direction opposite that of the first direction (e.g., by emerging from the constraints1126in the second direction). Each of the center motors1125B, F of these first and second sets can be bracing motors while the motors on the lateral sides, specifically motors1125A, C, D and E can be pushing motors. Because the two sets of motors point in different directions, the motors can be activated and deactivated in the same manner as previously discussed herein to push the layers of the strip1121relative to one another when coiled. While some of the previous embodiments pushed the coiling of the strip through one of a contraction or expansion phase and then relied upon the relaxation of the coiled strip to carry out the other of the contraction or expansion phase, pointing motors in opposite directions allows the radially adjustable structure to be actively pushed by motors through each of the contraction and expansion phases. The motors1125A-F are located at the first end1147of the strip1121but not on the second end1148of the strip1121.

FIG.14Bshows a strip1221having a single motor1225. The motor1225is housed partially within the constraint1226. The motor1225is located on the first end1247of the strip1221and not on the second end1248. As discussed preciously, a single motor1225can both push and brace instead of relying on multiple motors to separate push and brace functions.

FIGS.15A-Eillustrates an alternative configuration for utilizing expandable motors to move layers of a strip relative to one another. The strip is coiled to include a first layer1337and a second layer1338. The layers can correspond to any of the other layers of a radially adjustable structure. A plurality of motors1325A-D are mounted on the first layer1337(e.g., attached by an epoxy adhesive) and are not attached to the second layers1338, although the motors1325A-D may come into contact with the second layer1338as further explained. Each of the motors1325A-D may expand and contract based on application of an electrical signal, such as by being piezoelectric-based or any other type of motor referenced herein.

Constraints1345A-B can be attached (e.g., with adhesive such as epoxy) to a particular side of each of the motors1325A, C respectively, to cause these motors1325A, C to bend upon activation as shown inFIG.15B. As shown inFIG.15B, motors1325A, C are activated to expand, and in expanding also curl in the direction on which the constraints1345A, B are disposed on these motors. The curling action causes the motors1325A, C to push the second layer1338laterally while the longitudinal expansion of the motors1325A, C engages the second side1338to create separation between the layers1337,1338. It is the lateral pushing that incrementally moves (e.g., slides) the layers relative to one another to expand or contract a radially adjustable structure as discussed and shown previously. As shown inFIG.15C, motors1325B, D can act as bracing motors and activate to engage the second layer1338. Motor1325B, D may have a longer longitudinal expansion than motors1325A, C because motor1325B, D lack a constraint that otherwise redirects some of the expansion laterally. The activation of motors1325B, D lifts the second layer1335off of motors1325A, C to allow motor1325A, C to deactivate and contract as shown inFIG.15Dwhile motors1325B, D continue to brace the first layer1337relative to the second layer1338.FIG.15Eshows the deactivation of motors1325B, D to bring the first layer1337closer to the second layer1338such that all motors1325A-D are engaged with the second layer1338.

FIGS.15A-Erepresent a reciprocation cycle of motors1325A, C which can be repeated numerous times to incrementally move the first layer1337relative to the second layer1338to expand and/or contract a radially adjustable structure. The direction of movement can be reversed by providing a second set of motors, similar to motors1325A,C, except that the side of the motors on which the constraint1345A-B is placed is reversed such that the second set of motors curl to the left when activated instead of to the right as shown for motors1325A, C inFIG.15B. Such motion can reverse the relative sliding of the layers to that as shown inFIG.15B. In some embodiments, only one or more bending motors (e.g., motors1325A, C having constraints1345A, B) are provided on a strip while motors that merely extend straight (e.g., motors1325B, D), which perform a bracing function, are not included. The bending motors can cycle in a rapid manner as previously explained so that bracing is not needed because the reciprocation repeats before the strip can relax past the incremental pushing progress. It is noted thatFIGS.15A-Edemonstrate the use of motors to move layers of a strip that are not textured.

FIGS.16A-Cshow an alternative configuration for causing a first layer1437to move relative to a second layer1438. The layers1437,1438can correspond to any adjacent layers of a radially adjustable structure. The embodiment includes a plurality of motors1425A-E which are mounted (e.g., attached by an adhesive epoxy) on the first layer1437and are not directly attached to the second layer1438. Each of the motors1425A-E may be piezoelectric motors or any other type of expansion and/or contraction motor referenced herein. The particular embodiment shown includes two layers for each motor. Motor1425A includes layers1430A, B. Motor1425B includes layers1430C, D. Motor1425C includes layers1430E, F. Motor1425D includes layers1430G, H. Motor1425E includes layers1430G, H. Each motor layer can correspond to a different layer of piezoelectric material polled in a different direction than the other layer of the same motor. In some cases, the top layers1430B, D, F, H, and J may be active layers that elongate when electrically activated while bottom layers1430A, C, E, G, I may be constraint layers that are not electrically activated but are attached to the top layers and force the top layers to curl as shown when the top layers expand. Alternatively, the bottom layers1430A, C, E, G, I may contract when electrically activated simultaneous with the expansion of the top layers such that the layers work together to curl upward toward the second layer1438.

The motors1425A-C can be divided into a first group comprising motors1425A, C, E and a second group comprising motors1425B and D. These first and second groups of motors can be alternately activated as shown inFIGS.16B, C. When electrically activated, the motors1425A-E can project upward to engage the textured surface1428of the second layer1438. The motors1425A-E push against the slopes of the textured surface1428such that the motors force the second layer1438to slide relative to the first layer1437. The first and second groups of motors, and optionally more groups, can be positioned staggered relative to each other and positioned relative to the pattern of the textured surface1428such that at least one of groups of motors is always aligned with a downslope of the textured surface1428so that activation of the group pushes the layers of the strip relative to one another. The layers can be moved in the opposite direction by pushing against the opposite downslope as that shown inFIGS.16B, C.

FIGS.17A-Cshows an alternative motor design. This motor design can be used in the radially adjustable structures referenced herein, and can substitute for the piezoelectric-based motors referenced herein. The motor1525can be an electrostatic motor or an electromagnet motor. A top side of the motor1525is defined by a first insulative coating1533and a bottom side of the motor1525is defined by a second insulative coating1534. The motor includes a first terminal1531and a second terminal1532. The first terminal1531is electrically connected to a first pole1551. The second terminal1532is electrically connected to a second pole1552. A space exists between the first pole1551and the second pole1552. The first terminal1531and the second terminal1532are electrically connected via separate channels to the controller1540.

The controller1540can include a power source1541(e.g., a battery), an input1542(e.g., buttons or otherwise corresponding to input7of the embodiment ofFIG.1), and/or a processor1543. The controller1540manages output of control signals to the motor(s)1525in response to received input. Multiple conductors1516can extend from the controller1540to the first terminal1531and the second terminal1532, respectively, to electrically connect with the first pole1551in the second pole1552, respectively. The controller1540can supply one or more signals across the first pole1551and the second pole1552to create electric fields of the same polarity about the first pole1551and the second pole1552that repulse each other sufficient to move the first pole1551away from the second pole1552to elongate the motor1525. Additionally or alternatively, the controller1540can supply one or more signals to the first pole1551and the second pole1552to create electric fields of opposite polarity from the first pole1551and the second pole1552that attract each other sufficient to move the first pole1551toward from the second pole1552to elongate the motor1525. Expansion and/or contraction of reciprocation cycles can be performed by the motor1525based on these signals. In the case of an electrostatic design, charges can be built up from the signals on each of the first pole1551and the second pole1552to generate attractive or repulsive fields. In the case of an electromagnetic design, magnetic fields can be generated within each of the first pole1551and the second pole1552by sinusoidal signals run through helically wound conductors within the first pole1551and the second pole1552to generate attractive or repulsive electromagnetic fields.

FIGS.17B-Cillustrate possible configurations for the first pole1551and the second pole1552.FIGS.17B-Cshow how a first pole1551A can move relative to a second pole1552B, facilitated by intermeshed prongs of the first pole1551A and the second pole1552A.

WhileFIGS.6A-17Cdisclosed various ways to enable expansion and/or contraction of a part of a medical device with a radially adjustable structure,FIGS.18A-24show several configurations and applications for such expandable and/or contractible features.

FIG.18A-18Hshows a catheter1602having a distal section1605. The catheter1602can correspond with any catheter referenced herein, such as catheter2. Catheter1602is in the form of an elongated tube having a lumen1615. At least in the form of a tube, the catheter1602can be a round body. One or more radially adjustable structures can be mounted on the catheter1602in any manner referenced herein (e.g., embedded in the catheter wall in the manner ofFIG.2A-D).FIG.18Ashows the distal section1605of the catheter1602as having a uniform outer profile.FIG.18Bshows a funnel having been formed from the lumen1605in the distal section1605by a radially adjustable structure.

FIG.18Bshows object1656distal of the catheter1602. The catheter1602can be used to remove the object1656from within the body. The object1656can be a natural object such as body tissue or material that otherwise forms within the body. The object1656can be an artificial object such as an implantable component, stent, valve, filter, support, drain, or any artificial element introduced into the body. While a generally cylindrical object1656is shown, it will be understood that this can represent any number of shapes, including non-cylindrical shapes. It is noted that the object1656may have been deployed from the distal section of the lumen1605, such as in the case of the object1656being a stent, filter, valve, graft or other medical device.

The object1656is attached to an attachment tool1655. The attachment tool1655can include a hook, snare, grasping element, spear, or any other mechanism by which the object1656can be secured. A proximal section of the attachment tool1655can extend through one of the ports8shown inFIG.1. The attachment tool1615may be advanced distally until it engages attached to the object1656. Alternatively, the attachment tool1615may be advanced distally beyond the distal tip of the catheter1602with the object1656already attached to the attachment tool1615. The attachment tool1655can draw the object1656proximally toward the lumen1605and/or the catheter1602can be advanced distantly towards the object1656to close the distance between the catheter1602and the object1656. As an alternative to an attachment tool, or in combination with the attachment tool1655, aspiration through the lumen1615can be provided. In other words, fluid can be drawn through the lumen1615from the proximal section of the catheter (e.g., with a pump or syringe connected to one of the ports8shown inFIG.1) to suck the object1656into the lumen1615and optionally out the proximal section of the catheter1602.

FIG.18Cshows the object1656having entered the funnel of the lumen1605. It is noted that the funnel1605has a larger inner diameter distally and a smaller dinner diameter proximally. As shown inFIG.18D, this narrowing of the lumen1605forces the object1656to have a smaller profile as the object1656is moved within the lumen1605proximally and/or the catheter1605is moved distally with respect to the object1656.FIG.18Bshows the object1656having been moved further into the lumen1605, the outer profile of the object1656being reduced.FIG.18Fshows the profile of the object1656having been reduced to the inner diameter of the non-funnel portion of the lumen1605.FIG.18Gshows that the object1656has been moved through the lumen1605to be cleared from the lumen1605and catheter1602(e.g., removed from one of the ports8ofFIG.1).FIG.18Hshows the funnel having been collapsed by contraction of the radially adjustable structure disposed in the distal section1605of the catheter1602. This reduces the profile of the catheter1602to facilitate withdrawal of the distal section1605of the catheter1602from the body.

The catheter1602only underwent one movement cycle, comprising an expansion phase (FIGS.18A-C) and a contraction phase (FIGS.18G-H) for remove of the object1656, and the associated radially adjustable structure likewise only undergoes one cycle of expansion and then contraction. In some alternative embodiments, a catheter can undergo multiple movement cycles when capturing one object, as shown inFIGS.19A-F.

FIGS.19A-Fshow a sequence of a catheter1702having a distal section1705and a lumen1715capture an object1756. The catheter1702can be similar to any catheter referenced herein. For example, the catheter1702can include a radially adjustable structure embedded within the distal section1705to form a funnel shape as shown inFIG.19B. The object1756can be similar to any object referenced herein, such as object1656. While an attachment tool is not shown inFIGS.19A-F, an attachment tool can be used to control the object1756as with the demonstration shown inFIGS.18A-H. As described in connection withFIGS.18A-H, aspiration can be provided through the lumen1715to pull the object1756into the lumen1715. It is noted that the aspiration may not have enough power to force the object1756to have a smaller outer profile as the object encounters the funnel of the lumen1715. Therefore, when the object1756encounters the funnel of the lumen1715, as shown inFIG.19C, the radially adjustable structure on the distal section1705can contract to collapse the funnel around the object1756to force (e.g., compact) the object1756into a smaller profile as shown inFIG.19D. The funnel can then be re-expanded as shown inFIG.19E. The now partially compacted object1756can then be further drawn into the lumen1715as the funnel of the lumen1715is formed once again. The process of expanding the funnel and collapsing the funnel to incrementally reduce the profile of the object1756is further shown inFIGS.19G-Iuntil the object1756is entirely contained within the lumen1715as shown inFIG.19J. As such, the repeated expansion and contraction of the lumen1715can serve to repeatedly reduce the outer profile of sections of the object1715until the object can be entirely accommodated within an unexpanded portion of the lumen1715. It is noted thatFIGS.19A-Jrepresent multiple movement cycles of the catheter1702, and multiple expansion and contraction phases of the catheter1702and the radially adjustable structure mounted thereon. For example,FIGS.19A-Bcan represent an expansion phase,FIGS.19C-Dcan represent a contraction phase,FIGS.19D-Ecan represent another expansion phase,FIGS.19F-Gcan represent another contraction phase,FIGS.19G-Hcan represent another expansion phase, andFIGS.19I-Jcan represent another contraction phase. These phases can be driven by one or more motors and supported by one or more radially adjustable structures.

FIGS.20A-Cshow an embodiment of a catheter1802having multiple radially adjustable structures1810A-C located within the distal section1805of the catheter1802. The radially adjustable structures1810A-C are arrayed along the distal section1805. The radially adjustable structures1810A-C are not in contact with each other and have spaces therebetween. Each of the radially adjustable structures1810A-C can be independently controllable such that each can be selectively expanded or contracted. The radially adjustable structures1810A-C can be of any type referenced herein and contained in the catheter1802in any way referenced herein.

As shown inFIG.20B, expansion of the distal most radially adjustable structure1810A forms a funnel. As shown inFIG.20C, expansion of the second distal most radially adjustable structure1810B forms a deeper funnel (e.g., longer along the longitudinal axis of the catheter1802as compared to the funnel ofFIG.20B). As shown inFIG.20D, the radially adjustable structure1810A has contracted down to its original state while radially adjustable structure1810C has expanded.FIG.20Eshows that the radially adjustable structure1810B has contracted back to its original state while radially adjustable structure1810C remains expanded.FIG.20Fshows all of the radially adjustable structures1810A-C as having been contracted down to their original states ofFIG.20A. As such,FIGS.20A-Fshow that waves of expansion and contraction (as well as a bulge) can be propagated along the length of the catheter1802by selective expansion and contraction of multiple radially adjustable structures1810A-C. Such action can be thought of as gulping and/or swallowing of objects through the lumen1815to be removed by the catheter1802. In this manner, objects are accepted into the lumen1815and moved through at least the distal section1805of the catheter1802. It is noted that adjacent radially adjustable structures1810A-C can be in different phases of expansion and contraction of the wave pattern (e.g., both radially adjustable structures1810A, B are expanded inFIG.20Cwhile radially adjustable structures1810B, C expanded inFIG.20D). It is noted that the selective expansion of different radially adjustable structures1810A-C need not be for the purpose of capturing an object, and/or need not be at the distal section1805of the catheter1802so as to form a funnel. For example, the profile of the distal tip of the catheter1802may be unaffected by expansion of radially adjustable structures1810A-C.

FIGS.21A-Cshow an embodiment of a catheter1902that can grasp an object through contraction of one or more radially adjustable structures. The distal section1905of the catheter1902includes at least one radially adjustable structure1910, which can be of any type referenced herein, mounted in any manner referenced herein. While the radially adjustable structure1910is shown very close to the distal tip of the catheter1902, the radially adjustable structure1910can be anywhere along the length of the catheter1902, and in some cases multiple independently controllable radially adjustable structure can be arrayed along the catheter1902(e.g., similar to the embodiment ofFIG.20A-F). As shown inFIG.21B, a second catheter1956can be introduced to the lumen1915of the catheter1902. The second catheter1956can be any type of catheter, such as a guide wire, an implant delivery device, a monitoring device, and/or a therapy delivery device. The second catheter1956can enter the lumen1915from the proximal direction (e.g., through a port of a user handle) or from the distal direction (e.g., through the distal terminus of the lumen1915). As shown inFIG.21B, the second catheter1956can be extended distally of the catheter1902or otherwise traverse the radially adjustable structure1910. As shown inFIG.21C, the radially adjustable structure1910can be caused to contract to decrease the inner diameter of the lumen1915. The contraction of the lumen1915squeezes around the exterior of the second catheter1956to grasp the second catheter1956, optionally fixing the distal section1905of the catheter1902to the distal section of the second catheter1956. Manipulation of either of the catheter1902for the second catheter1956also manipulates the other such that advancement or retraction of the catheter1902also advances or retracts the second catheter1956and vice versa. Such grasping can be used to remove the second catheter1956from the body or remove any other object, natural or artificial, from the body by first squeezing the object to secure the object and then pulling the object from the body with the catheter1902.

FIGS.22A-Cshow how an expandable catheter2002can be used to deliver a stent or other implant. A catheter2002is introduced into a vessel2066. The vessel2066can be a blood circulatory pathway, an air pathway, a digestive pathway, or any other pathway within the body. Vessel2066includes a taper such that the inner diameter of the vessel2066changes along its length. A doctor may desire to implant stent2065(or other implant) in the vessel2066but the change in diameter of the vessel may be challenging for devices that are only expandable to a consistent diameter, such as a balloon. As discussed previously, one advantage of multiple radially adjustable structures is that different sections of the catheter can be expanded or contracted to different sizes at the same time. This may be advantageous when placing an implantable component in a vessel or other anatomical area having different dimensions. Being that the radially adjustable structures are selectively expandable and contractable, the size of the catheter can be dynamically changed as needed along the length of the catheter, as demonstrated byFIGS.22A-C. The catheter2002may be radiopaque so that the doctor can visualize the expanded size(s). Although the catheter2002includes a lumen2015, the lumen2015may not be present in all embodiments, such that the catheter2002is sealed at the distal tip.

A stent2065is mounted around the distal section2005of the catheter2002. Although a stent2065is shown, the stent2065can represent any type of implant, such as a valve, a filter, or a graft, among other options. Underneath the stent2065are multiple, spaced apart radially adjustable structures2010A-B mounted on the catheter2002. The radially adjustable structures2010A-B can be of any type referenced herein, and can be mounted on the catheter2002in any manner referenced herein. These arrayed radially adjustable structures2010A-B can be aligned with different portions of the vessel2066having different inner diameters. The radially adjustable structures2010A-B can be expanded by different amounts such that the outer diameter of the catheter2002is increased to different sizes along different longitudinal sections corresponding to the different radially adjustable structures2010A-B. For example, each of the radially adjustable structures2010A-B can be expanded to approximately the inner diameter of the portion of the vessel2066in which the respective radially adjustable structure resides during expansion to anchor the stent2065in the vessel2066. As shown inFIG.22B, this can result in implantation of the stent2052have different diameters along different longitudinal sections corresponding to different diameters of the vessel2066in which it is implanted to best fit the stent2065to the native profile of the vessel2066.

As shown inFIG.22C, the radially adjustable structures2010A-B can be contracted to decrease the outer diameter of the distal section2005while leaving the stent2065in its expanded state, and the catheter2002can be withdrawn to leave the stent2065in the vessel2066. While multiple radially adjustable structures2010A-B are used to deploy stent2065, a single radially adjustable structure may instead be provided on the catheter2002and used for deployment. In some embodiments, multiple stents or other implants can be arrayed along the length of the catheter2002and multiple radially adjustable structures mounted on the catheter2002, respectively underneath the multiple stents (e.g., one or multiple radially adjustable structure for each stent), can be selectively expanded to expand and deploy the stents. In some embodiments, a catheter deploys an implant or other device mounted around the catheter, not in part by the catheter expanding as inFIGS.22A-B, but rather by the catheter contracting from an original state to loosen the implant mounted around the catheter (similar toFIGS.22B-C). In some embodiments, the catheter2002or other medical device disclosed herein, with or without stent, can be expanded to engage plaque or other material or tissue to perform angioplasty within a vessel. Radial expansion as disclosed herein can push or compact tissue, such as plaque or blood clots, to improve the patency of a vessel.

FIGS.23A-Cillustrate an embodiment of an implantable body2170within a vessel2166. The implantable body2170can be implanted within the vessel2166by delivery from a catheter, such as in the manner of being expanded like the stent shown inFIG.22A-C(however, the delivery is not so limited and delivery may alternately include conventional techniques such as those used for implantation of a graft, stent, valve, filter or similar element as are known in the art). The implantable body2170may take the form of a tube having a wall that defines an outer circumference and a lumen2115. The lumen2115can help maintain flow within the vessel2166by allowing air or fluid (e.g., blood) to pass through the lumen2115.

Anchor elements2171are provided to anchor the implantable body2172to the walls of the vessel2166. The anchor elements2171may be metal hooks that are connected to the implantable body2170and that extend distally and/or proximally of the implantable body2170and laterally outward from the implantable body2170to engage, and possibly sink into, the walls of the vessel2166during implantation.

One or more radially adjustable structures2110, of any type referenced herein, can be mounted on the implantable body2170in any manner referenced herein. The one or more radially adjustable structures2110can be caused to expand, which can expand the inner and/or outer diameters of the implantable body2170as shown inFIG.23B. Such expansion may expand the inner diameter of the vessel2166as the implantable body2170presses up against the walls of the vessel2166as shown inFIG.23B. At other times, the one or more radially adjustable structures2110can be caused to contract to contract the inner and/or outer diameters of the implantable body2170as shown inFIG.23C. The contraction of the implantable body2170can cause the vessel2166to decrease in inner diameter as shown inFIG.23C. Such expansion and contraction may therapeutically regulate flow within the vessel2166by narrowing and widening the vessel2166. Additionally or alternatively, a nerve (e.g., renal or vagus) close to the vessel2166can measure tension within the vessel2166and relay such information to the central nervous system to regulate blood pressure or other physiological parameter. Expansion and/or contraction of the vessel2166, as shown inFIGS.23A-C, can cause the nerve to send signals to the central nervous system in response to the expansion and/or contraction. The central nervous system can then regulate the physiological parameter, such as blood pressure, in response to the expansion and/or contraction. The physiological parameter, such as blood pressure, can be controlled by the expansion and contraction of the implantable body2170.

FIG.24shows an implantable body2270that can be the same as the implantable body1670or otherwise have common features. The implantable body2270is implanted within a vessel2266. Implantable body2270includes radially adjustable structures2210A-B, which can be of any type referenced herein and can be embedded within the implantable body2270similarly to any embodiment referenced herein. While two radially adjustable structures2210A-B are shown on distal and proximal sections of the implantable body2270, just one, three, or another number of radially adjustable structures can instead be provided. The implantable body2270includes circuitry2272. The circuitry2272can be embedded within the wall of the tubular implantable body2270similarly to how the radially adjustable structures2210A-B, or other component referenced herein, can be embedded in a wall. Circuitry2272can include any of the components of the controllers840,1540. For example, circuitry2272can include a power source (e.g., a battery), an input (a pressure sensor, a biological parameter sensor such as a blood pressure sensor for closed loop operation, and/or telemetry for receiving a command), and/or a processor. The circuitry2272can output one or more signals to one or more motors within the radially adjustable structures2210A-B to control expansion and contraction of the radially adjustable structures2210A-B. In addition to a battery or as an alternative to a battery, an external transmitter2275can be provided outside of the skin2273to transcutaneously and wirelessly send command signals and/or energy (e.g., by inductive energy transfer) to the internal receiver2274. The internal receiver2274can be connected by one or more wires to the circuitry2272to convey command signals and/or power.

While various embodiment show a radially adjustable structure embedded in a catheter or an implantable body, it is noted that any radially adjustable structure disclosed herein, such as in the form of an annular body, may be used in a patient's body while exposed such that it is not embedded in a catheter or an implantable body. In such a case, individual electrical components may be individually coated and insulted with a thin polymer layer. While the disclosed embodiments generally discloses medical devices that can expand and contract, in some embodiment a medical device may only be able to expand or contract but not both.

The present disclosure is made using various embodiments to highlights various inventive aspects. Modifications can be made to the embodiments presented herein without departing from the scope of the invention. As such, the scope of the invention is not limited to the embodiments disclosed herein.