Multiple-expansion zone constraining apparatus and method

Abstract

A removable constraining device, system, and method for constraining and delivering an expandable member are disclosed. The removable constraining device includes a plurality of strands interlocked to form a covering body having a length, the plurality of strands being in a warp-knitted form, and the plurality of strands including at least a first set of strands and a second set of strands. The removable constraining device further includes a first release zone defined by the first set of strands of the covering body along the length of the covering body and a second release zone defined by the second set of strands of the covering body, the second release zone coextending with the first release zone along at least a portion of the length of the covering body. The removable constraining device can be released at the release zones by tensioning deployment lines substantially simultaneously.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of provisional patent application No. 62 / 980660, filed on February 24, 2020, the full text of which is incorporated herein by reference for all purposes. Technical Field

[0003] This disclosure generally relates to devices, systems, and methods for delivering implantable medical devices. More specifically, this disclosure relates to devices, systems, and methods for coverings used during device delivery of implantable medical devices. Background Technology

[0004] Minimally invasive delivery techniques for implantable medical devices offer several advantages, such as reduced trauma, infection risk, and recovery time. Examples of implantable medical devices include stents and stent grafts used for radial support, treatment, and / or other enhancement of tubular pathways within the body, including arteries, veins, airways, gastrointestinal tracts, and biliary tracts. Other examples of implantable medical devices include prosthetic valves (e.g., prosthetic heart valves). Transcatheter delivery is a technique for delivering such implantable medical devices, in which the device to be delivered begins in a compressed state of diameter for delivery and then expands at the treatment site within the patient (e.g., self-expanding or manually expandable).

[0005] Scaffolds, scaffold grafts, prosthetic valves, filters, and other implants can be expanded through plastic deformation (e.g., using an expandable sac) or allowed to expand and elastically recover from a collapsed or constrained delivery diameter to an expanded, unfolded diameter.

[0006] For example, U.S. Patent No. 6,224,627, filed June 15, 1998, entitled "Remotely Removable Covering and Support," primarily describes a thin, tubular, multifilament (membrane or fiber) structure capable of maintaining high internal pressure. The extensions of the filaments can be drawn in any direction to unfold the structure when desired. This structure can be used in self-expanding scaffold or scaffold graft delivery systems, cyst expansion catheters, removable guidewire lumens for catheters, drug infusion or aspiration catheters, guidewire bundle cannulas, removable filters, removable wire insulation, removable packaging, and other applications. Summary of the Invention

[0007] According to one example (“Example 1”), a removable constraint device includes multiple strands interlocked to form a cover body having a length, the multiple strands being warp-knitted and including a first set of strands and a second set of strands; a first release area defined by the first set of strands along the length of the cover body; a second release area defined by the second set of strands, the second release area extending along at least a portion of the length of the cover body together with the first release area; a first unfolding line defined by the first set of strands; and a second unfolding line defined by the second set of strands, wherein the first unfolding line is configured to release the cover body along the first release area by tensioning the first unfolding line, and the second unfolding line is configured to release the cover body along the second release area by tensioning the second unfolding line.

[0008] According to another example (“Example 2”) that is a further improvement on the device of Example 1, the first and second unfolding lines are connected to form a single unfolding segment.

[0009] According to another example (“Example 3”) that goes further than any of the preceding examples, the multiple strands forming the covering body include four strands.

[0010] According to another example (“Example 4”) that goes further than the device in Example 3, two of the four strands include a first set of strands that form a first spread line and define a first release area, and the two remaining strands of the four strands include a second set of strands that form a second spread line and define a second release area.

[0011] According to another example (“Example 5”) that is a further step of the device relative to any of the preceding examples, the first release area includes a first knitted row and the second release area includes a second knitted row.

[0012] According to another example (“Example 6”) that goes further than the device in Example 5, the first knit row includes a first plurality of knitted fabrics and the second knit row includes a second plurality of knitted fabrics.

[0013] According to another example (“Example 7”) that is a further step relative to the device of Example 6, the first plurality of knitted fabrics include a first knitted fabric and a second knitted fabric, and wherein the second plurality of knitted fabrics include a corresponding first knitted fabric and a corresponding second knitted fabric.

[0014] According to another example (“Example 8”) that goes further than the device in Example 7, when the first knitted fabric is not unfolded, the first knitted fabric interferes with the unfolding of the corresponding second knitted fabric.

[0015] According to another example (“Example 9”) that goes further than the device in Example 7 or 8, when the corresponding first knitted fabric is not unfolded, the corresponding first knitted fabric interferes with the unfolding of the second knitted fabric.

[0016] According to another example (“Example 10”) that goes further than any of the devices in Examples 7-9, the first knitted fabric and the corresponding first knitted fabric are positioned at substantially similar longitudes along the covering body.

[0017] According to another example (“Example 11”) that goes further than any of the preceding examples, the first release area and the second release area are configured to unfold substantially simultaneously by tensioning the first deployment line and the second deployment line substantially simultaneously.

[0018] According to another example (“Example 12”) that goes further than any of the preceding examples, the multiple strands comprise expanded polytetrafluoroethylene.

[0019] According to another example (“Example 13”) that goes further than any of the preceding examples, the cover is configured to provide resistance to the outward expansion of the restricted medical device.

[0020] According to another example (“Example 14”) that goes further than any of the preceding examples, each of the multiple strands has matching strand characteristics.

[0021] According to another example (“Example 15”) of the device relative to Example 14, the matching strand characteristics include strand thickness, strand denier number, strand friction coefficient, strand material, and strand stiffness.

[00021] According to another example (“Example 16”) of the device relative to any of the foregoing examples, the first unfolded line is integrally formed with one or more of the plurality of strands.

[0022] According to another example (“Example 17”) that is a further step of the device relative to any of the preceding examples, the second unfolded line is integrally formed with one or more of the multiple strands.

[0023] According to another example (“Example 18”), a medical device includes an expandable member configured to expand radially from a first diameter toward a second diameter; and a knitted restraint member positioned around the expandable member to restrain the expandable member in the first diameter, the knitted restraint member having a first release area configured to disengage the knitted restraint member from the expandable member, a first unfolding line operable to activate the first release area, a second release area configured to disengage the knitted restraint member from the expandable member, and a second unfolding line operable to activate the second release area, wherein the restraint member is configured to disengage from the expandable member by substantially simultaneously tensioning the first and second unfolding lines.

[0024] According to another example (“Example 17”) that is a further embodiment of the device relative to Example 18, the constraint members include a first main strand and a second main strand interlaced to form a first unfolded line, and a third main strand and a fourth main strand interlaced to form a second unfolded line.

[0025] According to another example (“Example 20”) that is a further improvement on the device of Example 19, the first main strand, the first spread strand, the second main strand, and the second spread strand are all intertwined.

[0026] According to another example (“Example 21”) that is a further improvement on the device of Example 20, the first main strand, the first unfolded strand, the second main strand and the second unfolded strand are warp-knitted.

[0027] According to another example (“Example 22”) that is further than any of the devices in Examples 19-21, a first main strand and a first unfolded strand form a first plurality of knitted fabrics along at least a first portion of the longitudinal length of the constraint member, and wherein a second main strand and a second unfolded strand form a second plurality of knitted fabrics along at least a second portion of the longitudinal length of the constraint member.

[0028] According to another example (“Example 23”) that goes further than the device of Example 22, the first release area includes a first plurality of knitted fabrics and the second release area includes a second plurality of knitted fabrics.

[0029] According to another example (“Example 24”) that is a further step of the device relative to Example 23, a first plurality of knitted fabrics are sequentially unraveled when a first threshold tension is applied across a first unfolding line, and wherein a second plurality of knitted fabrics are sequentially unraveled when a second threshold tension is applied across a second unfolding line.

[0030] According to another example (“Example 25”) that is a further step relative to the device of Example 24, the first unfolding line is interwoven with the second unfolding line and the second body strand, such that when the corresponding knit of the first plurality of knits is unraveled by moving the first unfolding line away from the first release area, the second plurality of knits can be operated to unravel.

[0031] According to another example (“Example 26”) that is a further improvement on the device of Example 24 or 25, the second unfolding line is interwoven with the first unfolding line and the first body strand, such that when the corresponding knit of the second plurality of knits is unraveled by moving the second unfolding line away from the second release area, the first plurality of knits can be operated to unravel.

[0032] According to another example (“Example 27”) that is a further device relative to any of Examples 18-26, the first and second unfolding lines each include a free end, wherein the free ends of the first and second unfolding lines are joined to form a single unfolding segment.

[0033] According to another example (“Example 28”) that goes further than any of the devices in Examples 18-27, the first release zone and the second release zone are configured to unfold substantially simultaneously.

[0034] According to another example (“Example 29”) that is a further device relative to any of Examples 18-27, the first unfolding line, the first body strand, the second unfolding line, and the second body strand comprise expanded polytetrafluoroethylene.

[0035] According to another example (“Example 30”) that goes further than any of the devices in Examples 18-29, the first and second release areas are configured to provide resistance to the outward expansion of the deployable member when it is not deployed.

[0036] According to another example (“Example 31”) that is further than any of the devices in Examples 18-30, the implantable medical device has a radial force under the delivery diameter of the deployable member, and wherein the first deployable line and the second deployable line are configured to be removed by the deployable force applied to the first deployable line and the second deployable line; and wherein the ratio of the radial force to the deployable force is between about 100 and about 500.

[0037] According to another example (“Example 32”) that is further than the device of Example 31, the ratio of radial force to unfolding force is between about 170 and about 475.

[0038] According to another example (“Example 33”) that is a further improvement on the device of Example 31, the ratio of radial force to unfolding force is between about 200 and about 450.

[0039] According to another example (“Example 34”) that is further than the device of Example 31, the ratio of radial force to unfolding force is between about 225 and about 425.

[0040] In another example (“Example 35”) that goes further than any of the devices in Examples 18-34, the ratio of the delivery diameter of the deployable component to the deployment diameter is less than 0.3.

[0041] According to another example (“Example 36”), an expandable medical device includes a deployable member and a removable constraint comprising a plurality of interlocking strands in the form of warp knitting, wherein the removable constraint is axially positioned outside the deployable member and oriented to restrict the deployable member in a radially compressed manner, wherein the plurality of interlocking strands include a first deployable line and a second deployable line, and wherein the removable constraint is configured to be remotely removed when a force is applied to the first deployable line and the second deployable line.

[0042] According to another example (“Example 37”) that goes further than the device in Example 36, the removable constraint includes a first release area and a second release area.

[0043] According to another example (“Example 38”) that is a further embodiment of the device relative to Example 37, the first release area is formed at least partially by a first unfolding line, and wherein the second release area is formed at least partially by a second unfolding line.

[0044] According to another example (“Example 39”) that is a further embodiment of the device relative to Example 38, the first release area is configured to unfold sequentially when tension is applied to the first unfolding line, and wherein the second release area is configured to unfold sequentially when tension is applied to the second unfolding line.

[0045] According to another example (“Example 40”) that goes further than any of the devices in Examples 36-39, the removable constraint is configured to be removed from the deployable member by applying forces substantially simultaneously to the first and second deployment lines.

[0046] According to another example (“Example 41”), a method of manufacturing an expandable medical device includes radially inwardly compressing an expandable member; interlacing multiple strands of wire including a first unfolded line and a second unfolded line to form a removable constraint; attaching the removable constraint to the expandable member while holding a portion of the first unfolded line away from the expandable member such that the portion of the first unfolded line extends away from the removable constraint; and holding a portion of the second unfolded line away from the expandable member such that the portion of the second unfolded line extends away from the removable constraint, wherein the first and second unfolded lines are operable to be tensioned such that the removable constraint is partially deconstructed when substantially simultaneously tensioned.

[0047] According to another example (“Example 42”) that goes further than the method of Example 41, the first proximal end of the first unfolding line is joined to the second proximal end of the second unfolding line so that they form a single (mono) unfolding segment.

[0048] According to another example (“Example 43”) that goes further than the method of Example 41 or 42, the step of interlacing the multiple strands occurs simultaneously with the step of installing the removable constraint.

[0049] According to another example (“Example 44”) that goes further than any of the methods in Examples 41-43, the step of interlacing multiple strands occurs simultaneously with compressing the expandable member, such that as the multiple strands interlac around the expandable member, the multiple strands provide compressive force to the expandable member.

[0050] According to another example (“Example 45”) that goes further than any of the methods in Examples 41-44, weaken the strands of each of the first and second development lines.

[0051] According to another example (“Example 46”) that goes further than any of the methods in Examples 41-44, at least one strand from each of the first and second spreads is broken.

[0052] According to another example (“Example 47”) that goes further than the method of Example 46, the release of the first and second release areas of the removable constraint is initiated.

[0053] According to another example (“Example 48”) that goes further than the method of Example 47, the steps to initiate the release of the removable constraint include tensioning the first and second deployment lines.

[0054] According to another example (“Example 49”) that goes further than the method of Example 48, tensioning of the first and second deployment lines is stopped before the first and second release areas are deconstructed around the expandable member.

[0055] According to another example (“Example 50”), a method of deploying a medical device includes positioning an expandable medical device within a patient’s body, wherein the expandable medical device is constrained in a compression configuration by a restraining member, wherein the restraining member includes a first release region configured to disengage the restraining member from the expandable medical device, a first deployment line operable to activate the first release region, a second release region configured to disengage the restraining member from the expandable medical device, and a second deployment line operable to activate the second release region; maintaining proximal portions of the first and second deployment lines away from the expandable medical device; and applying sufficient force to the proximal portions of the first and second deployment lines to activate the first and second release regions.

[0056] According to another example (“Example 51”) that goes further than the method of Example 50, the step of applying sufficient force to the proximal portions of the first and second unfolding lines includes: applying sufficient force to the proximal portions of the first and second unfolding lines simultaneously.

[0057] The foregoing examples are merely illustrative and should not be construed as limiting or otherwise narrowing the scope of any inventive concept otherwise provided by this disclosure. Although several examples have been disclosed, other examples will become apparent to those skilled in the art from the following detailed description, which illustrates and describes illustrative examples of the invention. Therefore, the drawings and detailed description should be considered illustrative in nature and not restrictive in nature. Attached Figure Description

[0058] The accompanying drawings are included to provide a further understanding of the present disclosure, and the drawings are incorporated in and form part of this specification, illustrate embodiments, and together with the description serve to explain the principles of the present disclosure.

[0059] Figure 1 It is a delivery system having removable constraints and expandable members according to one embodiment;

[0060] Figure 2 It is a removable constraint provided around an expandable device according to one embodiment;

[0061] Figure 3 It is a removable constraint member having knitted rows and various knitted fabrics according to one embodiment; and

[0062] Figure 4 It is a woven pattern implemented for a removable constraint according to one embodiment. Detailed Implementation

[0063] Definitions and Terms

[0064] This disclosure is not intended to be read in a restrictive manner. For example, the terms used in this application should be read broadly in the context of their meanings to be attributed to those skilled in the art.

[0065] Regarding imprecise terminology, the terms "about" and "approximately" are used interchangeably to refer to a measurement that includes the stated measurement value as well as any measurement value that is reasonably (comparably) close to the stated measurement value. As understood and readily determined by one of ordinary skill in the art, a measurement value reasonably close to the stated measurement value deviates from the stated measurement value by a reasonably small amount. Such deviations can be attributed to, for example, measurement errors, differences in measurement values ​​and / or manufacturing equipment calibration, human errors in reading and / or setting the measurement value, fine-tuning to optimize performance and / or structural parameters taking into account differences in measurement values ​​related to other components, specific implementation scenarios, imprecise adjustments and / or manipulations of the object by humans or machines, and / or the like. Where it is determined that such a reasonably small difference value would not be readily determined by one of ordinary skill in the art, the terms "about" and "approximately" can be understood as the value plus or minus 10%.

[0066] Certain terms are used herein for convenience only. For example, terms such as “top,” “bottom,” “up,” “down,” “left,” “right,” “horizontal,” “vertical,” “upward,” and “downward” describe only the orientation of the structure or component shown in the figure in its installation position. In reality, the referenced component may be oriented in any direction. Similarly, throughout this disclosure, if a process or method is shown or described, the method can be performed in any order or simultaneously unless it is clear from the context that the method depends on certain operations performed first.

[0067] Outward radial expansion force, or radial force, generally refers to the force caused by the internal forces of a device when it is formed from a plastically deformable material and is constrained or compressed to a smaller diameter. When a device is constrained to a smaller diameter, the outward radial expansion force causes the device to exert force on the constraining element. Therefore, the outward radial force can be a result of a self-expanding member. Such a self-expanding member may include shape memory alloys, which exert outward radial expansion forces when compressed and / or constrained. However, the outward radial expansion force can also refer to other forces that cause a device or component to expand radially outward, such as the expansion of angioplasty capsules.

[0068] A restraint force generally refers to the force exerted on a device by a restraining member when resisting an outward radial expansion force of the device; in some embodiments, the device is a self-expanding device. The restraint force can be considered as a normal force generated by the outward radial expansion force applied to the restraining member. In other words, when restraining the device, the restraining member can exert an inward radial force on the device. In some embodiments, the restraint force can be limited to a threshold amount until the restraining member can no longer resist the outward radial expansion force of the device, at which point the medical device can unfold due to the outward radial expansion force overcoming the restraint force of the restraining member, thus causing the restraining member to disengage.

[0069] Deployment force generally refers to the force required to deploy a medical device by disengaging the restraint member. In some embodiments, the deployment force is the force required to tension the activation line of the restraint member to activate the disengagement of the restraint member from the medical device.

[0070] For reference, the term "periphery" does not necessarily mean a circular cross-section, but should be understood broadly to refer to the outer surface or dimensions of a removable constraint.

[0071] Description of various embodiments

[0072] Those skilled in the art will readily understand that various aspects of this disclosure can be implemented by any number of methods and apparatuses configured to perform the intended functions. It should also be noted that the accompanying drawings referenced herein are not necessarily drawn to scale, but may be enlarged to illustrate various aspects of this disclosure, and in this regard, the drawings should not be construed as limiting.

[0073] Figure 1 The system shown provides examples of various features of the system, and although the combinations of those features shown are clearly within the scope of this disclosure, the examples and illustrations therein do not imply that the inventive concept provided herein is limited to one or more of the features from fewer features, additional features, or alternative features to those shown in the figures. Figure 1 This is a plan view of a delivery system 100 according to some embodiments, the delivery system including a conduit 102 having a removable constraint 104. Figure 1 As shown, the removable restraint 104 is configured to restrain the implantable medical device 106 into a delivery configuration. The removable restraint 104 may include one or more fibers or strands 108 disposed around the device 106 to hold the device 106 and the removable restraint 102 in the restraint or delivery configuration.

[0074] A removable restraint 104 is disposed along the length of device 104. The removable restraint 104 is also disposed circumferentially around device 106 and can substantially cover device 106 for delivery. One or more strands 108 may be disposed within the lumen (not shown) of catheter 102 and extend towards the proximal end of catheter 102, which may again be disposed outside the patient during delivery of device 106. One or more strands 108 may include a proximal end 110, which can be tensioned by a user to release the removable restraint 104 and deploy device 106.

[0075] In some cases, one or more strands 108 are released, such that interlocking portions (e.g., overlapping fibers or knitted fabrics) are released sequentially along the length of device 106. As explained in more detail below, removable restraints 104 are formed by interlocking one or more strands 108 located on device 106 together. One or more strands 108 may form release areas 124, 126, which include knitted rows 130, 132 for releasing device 106. Device 106 may be a stent, stent graft, capsule, prosthetic valve, filter, anastomosis device, occluder, or similar device.

[0076] Figure 2 This is a side view of a device 106 including a removable constraint 104 according to an embodiment. As shown, the device 106 includes a delivery diameter D1 and an expansion diameter D2 (not shown) larger than the delivery diameter D1. The removable constraint 104 is disposed around the device 106 below the delivery diameter D1. When the removable constraint 104 is removed from the device 106, the device expands to the expansion diameter D2. The expansion diameter D2 is larger than the delivery diameter D1. In some embodiments, the expansion diameter D2 is the diameter of the device 106 when it is unconstrained. In other embodiments, the expansion diameter D2 is the diameter of the device 106 once it has been delivered to the target site and engaged with the inner wall of the cavity at the target site.

[0077] The device 106 may have a desired unfolding diameter D2, for example, about 5 mm to 15 mm, or 6 mm to 9 mm, or 6 mm to 12 mm, and a delivery diameter D1 smaller than the unfolding diameter D2. For example, in some cases, the ratio of the delivery diameter D1 of the device 106 to the unfolding diameter D2 (not shown) of the device 106 (the ratio of D1 to D2) is less than about 0.3, less than about 0.29, less than about 0.28, less than about 0.27, or less than about 0.26.

[0078] like Figure 1 and 2 As shown, the removable constraint 104 includes at least two interlocking strands 108 in warp-knitted form. For example, the removable constraint 104 may include a first interlocking strand 112 and a second interlocking strand 114. The first interlocking strand 112 and / or the second interlocking strand 114 may operate, for example, as a first unfolding line 120, configured to release the removable constraint 104 and release the device 106 from the delivery diameter D1 to the unfolding diameter D2 in response to an unfolding force applied to the first unfolding line 120. The removable constraint 104 may also include a third interlocking strand 116 and a fourth interlocking strand 118. The third interlocking strand 116 and / or the fourth interlocking strand 118 may operate, for example, as a second unfolding line 122, configured to release the removable constraint 104 and release the device 106 from the delivery diameter D1 to the unfolding diameter D2 in response to an unfolding force applied to the second unfolding line 122. The removable constraint can be formed using two, four, six, eight, or any even number of interlocking strands, or any odd number of interlocking strands, within the scope of this disclosure. In one embodiment, the first unfolded line 120 and the second unfolded line 122 are joined together to form a single unfolded segment 121. In some embodiments, the first unfolded line 120 and the second unfolded line 122, or the single unfolded segment 121, includes the proximal end 110 of one or more strands 108.

[0079] Device 104 has a radial force at delivery diameter D1. The radial force generally refers to the force exerted by device 104 on movable constraint 102 at any time during the deployment of device 104. As described above, interlocking strands 112, 114 are adapted to be removed by a deployment force applied to deployment line 120. In some cases, the ratio of this radial force of device 104 to the deployment force applied to deployment lines 120, 122 (radial force to deployment force ratio) is less than about 500:1. In other cases, the ratio of this radial force of device 104 to the deployment force applied to deployment lines 120, 122 is less than about 475. Furthermore, the ratio of this radial force of device 104 to the deployment force applied to deployment lines 120, 122 may be less than about 450. Furthermore, in other cases, the ratio of this radial force of device 104 to the deployment force applied to deployment lines 120, 122 is less than about 425. Furthermore, the ratio of radial force to spreading force (the ratio of radial force to spreading force) may, for example, be between about 10, 20, 30, 40, 50, 100, 200, 300, 400 (or any number therein) and about 500, between about 10, 20, 30, 40, 50, 100, 200, 300, 400 (or any number therein) and about 475, between about 10, 20, 30, 40, 50, 100, 200, 300, 400 (or any number therein) and about 450, or between about 10, 20, 30, 40, 50, 100, 200, 300, 400 (or any number therein) and about 425.

[0080] One or more strands 108, including the interlocking wires 112, 114, 116, 118 in some embodiments, can be formed of various materials, including, for example, polytetrafluoroethylene (PTFE), expanded polytetrafluoroethylene (ePTFE), polyester, polyurethane, fluoropolymers such as perfluoroelastomers, polytetrafluoroethylene, silicone, polyurethane (urethane), ultra-high molecular weight polyethylene, aromatic polyamide fibers, and combinations thereof. Other embodiments for strands 112, 114, 116, 118 may include high-strength polymer fibers, such as ultra-high molecular weight polyethylene fibers (e.g., Dyneema (etc.) or aramid fibers (e.g., (etc.). Generally, as those skilled in the art will understand, ASTM or other recognized measurement techniques and standards can be used to evaluate any of the aforementioned characteristics.

[0081] Various strands 112, 114, 116, and 118 can be selected to have specific properties, such as strand thickness, strand denier number, strand friction coefficient, strand material, strand treatment, strand coating, and strand stiffness. Similar to different diameters, using different strand materials for strands 112, 114, 116, and 118 can increase friction between the first interlocking strands and the second interlocking strands 112, 114, 116, and 118 to help maintain device 104 in the delivery configuration. Depending on the application where removable constraints will be used, each of the various strands can be selected to include the same or different strand characteristics. It should be recognized that, in addition to material selection, the properties of strands 112, 114, 116, and 118 can also be altered through treatment, construction, and modification. For example, the strands may include filler or core materials and may be surface-treated primarily by etching, vapor deposition, coronal notching, or other plasma treatments, as well as other processing types, including coating with suitable coating materials.

[0082] Further reference Figure 2The removable constraint 104 may include a first release area 124 and a second release area 126. The first release area 124 may be defined along at least a portion of the longitudinal length of the removable constraint 104. The second release area 126 may be defined along at least a portion of the longitudinal length of the removable constraint 104. In some embodiments, the first release area 124 and the second release area 126 extend together along the longitudinal length of the removable constraint. The first release area 124 and the second release area 126 may be spaced apart from each other around the periphery or outer dimension of the removable constraint 104. In some embodiments, the first release area 124 and the second release area 126 may be spaced apart from each other transversely across the periphery or outer dimension of the removable constraint 104. In other embodiments, the first release area 124 and the second release area 126 are disposed on a first surface of the removable constraint 104. In one embodiment, a first release area 124 is spaced apart from and adjacent to a second release area 126 around the outer dimension or periphery of the removable constraint 104, and extends along the longitudinal length of the removable constraint and the second release area 126. According to one embodiment, the first release area 124 and the second release area 126 may be positioned at different locations around the periphery of the removable constraint 104. The release areas may be spaced apart around the periphery from about 10 degrees to about 180 degrees, from about 20 degrees to about 30 degrees, from about 30 degrees to about 45 degrees, from about 45 degrees to about 60 degrees, from about 60 degrees to about 75 degrees, from about 75 degrees to about 90 degrees, from about 90 degrees to about 105 degrees, from about 105 degrees to about 120 degrees, from about 120 degrees to about 135 degrees, from about 135 degrees to about 145 degrees, from about 145 degrees to about 160 degrees, and from about 160 degrees to about 180 degrees. For example, the release zones may be spaced apart by approximately 180 degrees, approximately 90 degrees, approximately 60 degrees, or any other distance as desired. The release zones may be spaced approximately equidistant around the perimeter of the removable constraint 104, or they may be offset as desired.

[0083] like Figure 2As can be seen, the removable constraint 104 may include two release areas 124, 126. The first release area 124 may include a first knitted row 130. The second release area 126 may include a second knitted row 132. Knitted rows 130, 132 may be formed by the interlocking of various strands 112, 114, 116, 118 discussed previously. For example, the first knitted row 130 may include the portion where the first strand 112 and the second strand 114 (here) of the removable constraint 104 interweave. The second knitted row 132 may include the portion where the third strand 116 and the fourth strand 118 (here) of the removable constraint 104 interweave. In some embodiments, the first strand 112, the second strand 114, the third strand 116, and the fourth strand 118 are all interwoven to form a removable constraint 104. A first release area 124 includes a first knitted row 130 formed at portions of the first strand 112 and the second strand 114 where the first strand 112 and the second strand 114 interweave. A second release area 126 includes a second knitted row 132 formed at portions of the second strand 116 and the third strand 118 where the third strand 116 and the fourth strand 118 interweave. It should be understood that the removable constraint is not limited to only two release areas, but can be implemented with any number of release areas, including a third release area formed by a third set of strands, a fourth release area formed by a fourth set of strands, or any number of release areas formed by corresponding sets of strands.

[0084] The removable constraint 104 may include a first unfolding thread 120 and a second unfolding thread 122 configured to unfold the device 106 by disengaging the removable constraint 104 from the device 106. This can be done via the unwinding of the knitted rows 130, 132 of the first release area 124 and the second release area 126, and thus the unwinding of portions of the body of the removable constraint 104. In one embodiment, the first unfolding thread 120 extends from and engages with the first knitted row 130 such that the first unfolding thread 120 is operable to disengage from or unwind at least a first portion of the first knitted row 130. The first unfolding thread 120 may include portions of each of the strands constituting the first knitted row 130; for example, the first unfolding thread 120 may include a first strand 112 and a second strand 114. Similarly, a second spread 122 extends from and engages with the second knit row 132, such that the second spread 122 is operable to disengage from or untie at least a first portion of the second knit row 132. The second spread 122 may include portions of each of the strands constituting the second knit row 132; for example, the second spread 122 may include a third strand 116 and a fourth strand 118. When the respective spreads 120, 122 engage, each of the knit rows 130, 132 is operable to untie sequentially.

[0085] Figure 3 An example is shown where the first knit row 130 may include a first knit 131a, a second knit 131b, a third knit 131c, etc. A first spread 122 may be an extension or free end of a first interlacing strand 112, which, together with portions of a second interlacing strand 114, forms the first knit row 130. In some embodiments, the first spread 122 is integrally formed with either the first strand 112 or the second strand 114. The first knit 131a unwinds as the first spread 122 is engaged or tensioned to move away from the removable constraint 104. The second knit 131b unwinds as the first spread 122 continues to be tensioned and moves away from the removable constraint 104. This continues until the first knit row 130 has been partially or completely unwinded. Similar patterns and features may appear with respect to the second knit row 132 and its corresponding knits 133a, 133b, 133c. In some embodiments, the first unfolding line 122 may include the knitted portions of the first strand 112 and the second strand 114.

[0086] In some embodiments, the interlaced yarns 112, 114, 116, 118 are knitted such that the first knit row 130 and the second knit row 132 unfold substantially simultaneously to facilitate the unwinding of knit rows 130, 132, and more specifically, the unwinding of the yarns at knit rows 130, 132 of the removable constraint 104. Because the yarns 112, 114, 116, 118 are interlaced, when the first knit row 130 or the second knit row 132 advances or unwinds at a different rate than the other knit row, the yarns forming the other knit row interfere with the proper unwinding of the previous knit row. This occurs by binding or restricting the unfolded yarn at one knit row until the other knit row has advanced sufficiently to release the unfolded yarn from the other knit row. Because all the yarns 112, 114, 116, 118 are interlaced, such restriction on the unfolded yarns 120, 122 may occur when any of the knit rows 130, 132 unwinds disproportionately relative to the other.

[0087] For example, if the first unfolded thread 122 is tensioned to untangle the first knit 131a, and the first unfolded thread 122 remains tensioned while the corresponding first knit 133a of the second knit row 132 has not yet untangled, then the ply yarns 116, 118 of the second knit row 132 may interfere with the untangling of the second knit 131b. In this example, the first ply yarn 112 of the first knit row 130 may interweave with the ply yarns 116, 118 of the second knit row 132, preventing the first knit row 130 from advancing until the first ply yarn 112 and / or the second ply yarn 114 are released from the ply yarns 116, 118 of the second knit row 132 via the release or untangling of the corresponding first knit 133a of the second knit row 132. However, if the corresponding first knit 133a of the second knit row 132 is unraveled, the first strand 112 and / or the second strand 114 can be released from the corresponding first knit 133a, allowing the tension across the first unfolding line 122 to initiate the unfolding of the second knit 131b, which can then be unraveled. Note that the reverse is also possible, such that if the corresponding knit of the first knit row 130 is not unfolded, the second unfolding line 124 may be restricted, preventing the second knit row 132 from being unraveled.

[0088] In some embodiments, the corresponding knitted fabrics of the first knitted row 130 and the second knitted row 132 must be unrolled before the subsequent (next) knitted fabric in the knitted row can be sequentially unrolled. In other embodiments, the ply yarns 112, 114, 116, and 118 interweave such that the subsequent knitted fabric can be unrolled when the corresponding knitted fabric of another knitted row has not been unrolled. In yet another embodiment, the ply yarns 112, 114, 116, and 118 interweave such that the subsequent (next) knitted fabric (e.g., the second knitted fabric 131b) in the knitted row can be unrolled when the corresponding knitted fabric (e.g., the corresponding first knitted fabric 133a); however, when the corresponding knitted fabric has not been unrolled, the knitted fabric following the subsequent (next) knitted fabric (e.g., the third knitted fabric 131c) may be restricted. The pattern used to interweave the various ply yarns can be varied to provide various interactions between the knitted rows to restrict unwinding. For example, a knitted row can be unraveled or advanced at two, three, four, or five knitted layers based on the weave or knitting pattern, later than the unraveling of the corresponding complete knitted layer of another knitted row (other than the unraveling of the corresponding complete knitted layer of another knitted row), which can change the constraint force and / or the unfolding accuracy during delivery and unfolding of the device 106.

[0089] In some embodiments, it is understood that the removable constraint 104 may be formed as two sleeves. The first sleeve may be formed from a first strand 112 and a second strand 114, and the second sleeve may be formed from a third strand 116 and a fourth strand 118. The two sleeves and their respective strands are understood to overlap and intertwine or interweave such that they are coaxial and can resist unfolding when one sleeve unfolds further than the other; however, each sleeve forms knitted rows that are independent of the other knitted rows of the corresponding sleeve. This means that the knitted rows are formed by the strands of that sleeve and not the strands of the other sleeve. However, as previously stated, when the corresponding knitted rows are not unfolded along substantially similar lengths of the removable constraint by binding (binding) or restricting the fibers of the other sleeve, the corresponding knitted rows may interfere with or restrict the unfolding of the other knitted rows.

[0090] Now for reference Figure 4 A removable constraint 104 is provided according to an embodiment. Figure 1-3 A schematic diagram of interlocking strands. Interlocking strands (e.g., first interlocking strand 112 and second interlocking strand 114, as shown) are typically interwoven to form at least one knit row 130. As shown, the knit row 130 is formed by interlocking loops formed by the first interlocking strand 112 and the second interlocking strand 114. For example, a first knit 134 is formed by interlocking loops 134 of the first interlocking strand 112, which interweave with second interlocking loops 136 formed by the second interlocking strand 114. By applying a spreading force (releasing the knitting force) to the spreading yarn, the interlocking ring structure allows the release of the removable constraint 104.

[0091] Turning now to a discussion of methods for manufacturing and using removable constraints, a method is provided for deploying a device having the disclosed removable constraint. As previously described, the medical device may include an expandable device capable of expanding and contracting to various diameters, including a first limiting diameter D1 and a second expansion diameter D2. The expandable device may be maintained in a constrained configuration by a removable constraint comprising multiple strands interwoven to form a first release area and a second release area, each strand comprising a knitted row (knitted fabric) having multiple knitted fabrics (weaves). In some embodiments, at least one deployment line extends from each release area.

[0092] A method of deploying a medical device may include intravenous delivery of the device to a treatment site. The expandable medical device is positioned within a patient, wherein the expandable medical device is constrained in a compression configuration by a removable restraint. A first release area is configured to disengage the removable restraint from the expandable medical device via a first deployment line operable to activate the first release area. A second release area is configured to disengage the removable restraint from the expandable medical device via a second deployment line operable to activate the second release area. A user may hold portions of the first and second deployment lines away from the expandable medical device, i.e., outside the venous access site (entry point). The user may then apply sufficient force to the first and second deployment lines to activate the first and second release areas. When the first and second release areas are activated, the medical device can be released from the removable restraint and deployed within the patient's anatomy. Thus, when the release areas are activated, the removable restraint is at least partially deconstructed and the expandable device can expand from the restraint diameter to the deployment diameter.

[0093] In some embodiments, the method includes applying sufficient force simultaneously to the free ends of the first and second unfolding threads, or applying such forces in a relatively close temporal sequence. As mentioned above, this step can be important when multiple strands are interwoven, causing the knitted fabric in the unfolding area to interfere with the release or unfolding of the corresponding knitted fabric. When the unfolding threads are activated, they can be translated away from the delivery site. Multiple threads can be removed via a conduit.

[0094] This disclosure also relates to a method of manufacturing an expandable medical device. The method may include radially inwardly compressing an expandable member to a first compression diameter. Multiple strands of yarn, including a first unfolding line and a second unfolding line, may be interlaced to form a removable constraint. The removable constraint may be interlaced such that a first unfolding region and a second unfolding region are formed by two knitted rows as described above. The method may include providing a first free end of the first unfolding line such that at least a portion of the first unfolding line extends away from the removable constraint, and providing a second free end of a second unfolding line such that at least a portion of the second unfolding line extends away from the removable constraint. When unfolded substantially simultaneously, the first and second free ends are operable to deconstruct (unwind / disassemble) the removable constraint. The method may further include concatenating the first and second free ends such that they form a single (mono) unfolding segment.

[0095] The manufacturing method may further include weakening (reducing) at least one strand comprising the covering member, such that the strand is operable to break. When at least one strand breaks, the unfolding portion of the corresponding knitted row can begin to unfold. Thus, in some embodiments, one strand from each knitted row may be weakened (reduced) so that the strand breaks from each knitted row. In some embodiments, the weakened (reduced) strand comprises the unfolding line of the knitted row. In other embodiments, the unreduced strand comprises the unfolding line of the knitted row such that when the unreduced strand is tensioned, the unreduced strand remains intact and the weakened strand breaks, which initiates the unfolding of the knitted row. The knitted row may initially be tensioned to provide the first break. Tension may then be applied to the unbroken, unreduced (reduced) strand to allow the continued unfolding of the knitted row due to the unwinding of the knitted row as it unwinds under tension. The knitted row continues to unwind due to the breaks in the strands that allow the knitted row to unwind or separate. Weakening (reducing) of the stock line can be achieved by scratching, cutting, manipulating, or otherwise damaging the stock line so that it can break under predetermined conditions such as tension.

[0096] As part of the manufacturing method, the unfolding of the cover member can be initiated by breaking at least one strand from each knitted row. The cover member can be unfolded relative to the expandable member to a desired length. For example, the cover member can be knitted to a length longer than the expandable member. The cover member can be activated to initiate unfolding. The cover member can be partially unfolded until a desired length is reached, such as the length of the cover member surrounding the expandable member and not extending beyond the longitudinal end of the expandable member. At this point, the unfolding can be interrupted until the medical device is ready to unfold at the target location. It should be understood that the cover member can be partially unfolded to any desired length. The partially unfolded cover member, which then constrains the expandable member, is ready for packaging, use, installation on a catheter, or any other desired action.

[0097] In some embodiments, the method includes performing a step of compressing the expandable member, which is performed simultaneously with the step of compressing the expandable member, such that the multiple strands provide a compressive force to the expandable member when the multiple strands interweave around the expandable member.

[0098] In some embodiments, the cover member may be woven onto the mandrel. Once the cover member is woven, and in some embodiments partially unraveled, the cover member can be removed from the mandrel and applied to a radially compressed implantable medical device.

[0099] The invention of this application has been described above generally and with reference to specific embodiments. It will be apparent to those skilled in the art that various modifications and alterations can be made to the embodiments without departing from the scope of this disclosure. Therefore, the embodiments are intended to cover modifications and variations of the invention, provided they fall within the scope of the appended claims and their equivalents.

Claims

1. A medical device comprising: An expandable member configured to expand radially from a first diameter toward a second diameter; as well as A knitted fabric restraint member, positioned around an expandable member to restrain the expandable member under a first diameter, the knitted fabric restraint member having a first release area extending along a first longitudinal length of the expandable member and configured to disengage the knitted fabric restraint member from the expandable member; a first development line operable to activate the first release area, wherein the first release area includes a plurality of first plurality of knitted fabrics unraveled by the first development line; a second release area extending along the length of the expandable member and configured to disengage the knitted fabric restraint member from the expandable member; and a second development line operable to activate the second release area, wherein the second release area includes a plurality of second plurality of knitted fabrics unraveled by the second development line, the first longitudinal length and the second longitudinal length overlapping along the length of the expandable member. The constraint member is configured to detach from the expandable member by substantially simultaneously tensioning the first and second development lines, and The first plurality of knitted fabrics and the second plurality of knitted fabrics are constrained one-to-one along the longitudinal length within the knitted fabric constraint member, such that the unraveling of each first knitted fabric is based on the simultaneous unraveling of the corresponding second knitted fabric.

2. The medical device of claim 1, wherein, The constraint member includes a first main strand and a second main strand interwoven to form the first development line, and a third main strand and a fourth main strand interwoven to form the second development line.

3. The medical device of claim 2, wherein, The first main stock line, the first expansion line, the second main stock line, and the second expansion line are all intertwined.

4. The medical device of claim 3, wherein, The first main stock line, the first expanded line, the second main stock line, and the second expanded line are warp-knitted.

5. The medical device of any of claims 2-4, wherein, The first main strand and the first unfolded strand form a first plurality of knitted fabrics along at least a first portion of the longitudinal length of the constraint member, and wherein the second main strand and the second unfolded strand form a second plurality of knitted fabrics along at least a second portion of the longitudinal length of the constraint member.

6. The medical device as described in claim 5, characterized in that, When a first threshold tension is applied across the first development line, the first plurality of knitted fabrics are sequentially unraveled, and wherein, when a second threshold tension is applied across the second development line, the second plurality of knitted fabrics are sequentially unraveled.

7. The medical device as described in claim 6, characterized in that, The first unfolding line interweaves with the second unfolding line and the second main strand, such that when the corresponding knitted fabric in the first plurality of knitted fabrics is untied by moving the first unfolding line away from the first release area, the second plurality of knitted fabrics can be operated to untie.

8. The medical device as described in claim 6 or 7, characterized in that, The second unfolding line interweaves with the first unfolding line and the first main strand, such that when the corresponding knitted fabric in the second plurality of knitted fabrics is untied by moving the second unfolding line away from the second release area, the first plurality of knitted fabrics can be operated to untie.

9. The medical device as described in any one of claims 1-4, characterized in that, The first unfolding line and the second unfolding line each include a free end, wherein the free ends of the first unfolding line and the second unfolding line are connected to form a single unfolding segment.

10. The medical device as described in any one of claims 2-4, characterized in that, The first unfolding line, the first main strand line, the second unfolding line, and the second main strand line all include expanded polytetrafluoroethylene.

11. The medical device as described in any one of claims 1-4, characterized in that, The first release zone and the second release zone are configured to provide resistance to the outward expansion of the expandable member when it is not deployed.

12. The medical device as described in any one of claims 1-4, characterized in that, The medical device has a radial force under the delivery diameter of the expandable member, and wherein the first and second unfolding lines are configured to be removed by an unfolding force applied to the first and second unfolding lines; and wherein the ratio of the radial force to the unfolding force is between 100 and 500.

13. The medical device as described in any one of claims 1-4, characterized in that, The ratio of the delivery diameter to the unfolding diameter of the expandable component is less than 0.

3.

14. The medical device as claimed in claim 1, characterized in that, The first longitudinal length and the second longitudinal length overlap along the entire length of the expandable member.

15. An expandable medical device, comprising: Deployable components; as well as Removable constraint, the removable constraint comprising multiple interlocking strands in a warp-knitted form, The removable constraint is axially positioned outside the deployable member and radially compresses and restricts the deployable member, and includes a first plurality of knitted fabrics and a second plurality of knitted fabrics. The interlocking strands include a first development thread extending from the first plurality of knitted fabrics and a second development thread extending from the second plurality of knitted fabrics, and The removable constraint is configured to be remotely removed when force is applied to the first and second development lines, wherein the first plurality of knitted fabrics and the second plurality of knitted fabrics are constrained one-to-one within the removable constraint, such that the unraveling of each first knitted fabric is based on the simultaneous unraveling of the corresponding second knitted fabric.

16. The expandable medical device as described in claim 15, characterized in that, The removable constraint includes a first release area and a second release area.

17. The expandable medical device as described in claim 16, characterized in that, The first release area is formed at least partially by the first unfolding line, and the second release area is formed at least partially by the second unfolding line.

18. The expandable medical device as claimed in claim 17, characterized in that, The first release region is configured to sequentially unwind when tension is applied to the first unfolding line, and the second release region is configured to sequentially unfold when tension is applied to the second unfolding line.

19. The expandable medical device as described in any one of claims 15-18, characterized in that, The removable constraint is configured to be removed from the deployable member by applying forces substantially simultaneously to the first and second deployment lines.

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