Restraint mechanisms and related methods for selective deployment

Abstract

Various aspects of the present disclosure are directed to medical device deployment apparatus, systems, and methods that include a restraint configured to releasably restrain a medical device, the restraint being capable of unravelling at various rates.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of Provisional Application No. 62 / 746,270, filed October 16, 2018, and also claims the benefit of Provisional Application No. 62 / 741,948, filed October 5, 2018, both of which are incorporated by reference in their entireties for all purposes.

[0002] Field The present disclosure relates to devices, systems and methods including a constraint for use in the delivery of an implantable medical device, and more particularly, to devices, systems and methods including a constraint for selectively deploying an expandable device during device delivery. [Background technology]

[0003] background Stents and stent grafts may be utilized to provide radial support to a variety of tubular passageways within the body, including arteries, veins, airways, gastrointestinal tracts, and biliary tracts. The preferred method for placing these devices has been to precisely position and deploy the device at the site of treatment using specialized delivery systems. These delivery systems allow the practitioner to minimize the trauma and technical difficulties associated with device placement. Attributes of the delivery systems include low profile, ability to pass through introducer sheaths, ability to navigate smoothly and atraumatically through tortuous vasculature, protection of constrained devices, and ability to precisely position and deploy the device.

[0004] A stent or stent-graft can be deployed and plastically deformed by using an inflatable balloon (e.g., a balloon-expandable stent), or can self-expand and elastically recover from a collapsed or constrained delivery diameter to an expanded and deployed diameter (e.g., a "self-expandable" device). Some stents are designed to elastically recover by being manufactured at a functional diameter from a material with elastic recovery properties and then radially compressed and mounted on a delivery catheter.

[0005] These stent and stent-graft devices may be held, compressed or restrained in a delivery configuration prior to and during delivery to the target location. Summary of the Invention

[0006] Abstract In one example ("Example 1"), a medical device deployment apparatus is configured to releasably restrain a medical device, the restraint including a plurality of interlocking strands forming a first knot row configured to unravel at a first deployment rate and a second knot row configured to unravel at a second deployment rate different from the first deployment rate, wherein disturbing the strands of the first knot row initiates unraveling of at least a portion of the restraint at the first deployment rate and disturbing the strands of the second knot row initiates unraveling of at least a portion of the restraint at the second deployment rate.

[0007] In another example ("Example 2"), in addition to the device of Example 1, the deployment ratio between the first knot row and the second knot row is 10:1.

[0008] In another example ("Example 3"), in addition to the device of any one of Examples 1-2, the deployment device also includes a third knot row spaced apart from the first knot row and the second knot row, and upon disturbing the strands of the third knot row, initiates unraveling of at least a portion of the restraint at a third deployment rate different from the first deployment rate and the second deployment rate.

[0009] In another example ("Example 4"), in addition to the device of Example 3, a deployment ratio between the first knot row and the second knot row is different from a deployment ratio between the second knot row and the third knot row.

[0010] In another example ("Example 5"), in addition to the device of Example 4, the first row of knots, the second row of knots, and the third row of knots are equally spaced around the circumference of the restraint.

[0011] In another example ("Example 6"), in addition to the device of Example 4, the first row of knots, the second row of knots, and the third row of knots are non-uniformly spaced around the circumference of the restraint.

[0012] In another example ("Example 7"), further to the apparatus of Examples 1-6, disrupting the first knot row includes breaking a strand of the first knot row, and disrupting the second knot row includes breaking a strand of the second knot row.

[0013] In another example ("Example 8"), further to the apparatus of Examples 1-7, disturbing the first knot row includes altering a tension in at least one strand of the first knot row, and disturbing the second knot row includes altering a tension in at least one strand of the second knot row.

[0014] In another example ("Example 9"), in addition to the device of Examples 1-8, the first knot row is configured to be disrupted before the second knot row.

[0015] In another example ("Example 10"), further to the device of Examples 1-9, the second deployment rate is faster than the first deployment rate.

[0016] In another example ("Example 11"), further to the device of Examples 1-10, the strands of the first knot row are distinguishable from the strands of the second knot row by color.

[0017] In another example ("Example 12"), further to the device of Examples 1-11, the strands of the first knot row are distinguishable from the strands of the second knot row by markings.

[0018] In another example ("Example 13"), further to the device of Examples 1-12, the strands of the first knot row are distinguishable from the strands of the second knot row by texture.

[0019] In another example ("Example 14"), further to the apparatus of Examples 1-13, the plurality of interlocking strands form a warp knit pattern.

[0020] In another example ("Example 15"), further to the device of any one of Examples 1-14, the pattern formed by the plurality of interlocking strands varies along the length of the restraint.

[0021] In another example ("Example 16"), further to the device of Example 15, the plurality of interlocking strands are formed into a plurality of knot rows, including the first knot row and the second knot row, that increase or decrease in number along the length of the restraint.

[0022] In another example ("Example 17"), further to the device of Example 15, the plurality of interlocking strands form a plurality of knot rows, including the first knot row and the second knot row, and interactions between the plurality of interlocking strands vary along the length of the restraint.

[0023] In one example ("Example 18"), a method of using a medical device deployment apparatus includes providing a restraint including a first knot row and a second knot row, disturbing strands of the first knot row to initiate unravelling of at least a portion of the restraint at a first deployment speed, and disturbing strands of the second knot row to initiate unravelling of at least a portion of the restraint at a second deployment speed greater than the first deployment speed.

[0024] In another example ("Example 19"), in addition to the method of Example 18, the method also includes disturbing strands of a third knot row to unravel at least a portion of the restraint at a third deployment rate different from the first deployment rate and the second deployment rate.

[0025] In another example ("Example 20"), further to the method of any one of Examples 18-19, disrupting the strands of the first knot row includes breaking the strands.

[0026] In one example ("Example 21"), a deployment apparatus for a medical device includes a removable restraint including a plurality of interlocking strands in a warp knit form having a perimeter and having a plurality of knot rows spaced apart about the perimeter, where when one of the knot rows is disturbed, the removable restraint becomes unraveled and remotely removable when a force is applied to a deployment line, where the plurality of knot rows are non-uniformly distributed about the perimeter, and where a rate of removal of the removable restraint differs depending on which knot row is disturbed.

[0027] In another example ("Example 22"), in addition to the device of Example 21, the plurality of knot rows are configured to be perturbed in response to a user selecting one of the plurality of rows such that the user can select a rate of restraint removal.

[0028] In another example ("Example 23"), further to the device of any one of Examples 20-21, the plurality of rows are configured to unravel in a set sequence to define a rate of restraint removal.

[0029] In another example ("Example 24"), further to the device of any one of Examples 20-21, the interlocking strands are distinguishable from one another.

[0030] In another example ("Example 25"), in addition to the device of Example 24, the interlocking strands are distinguishable from one another by being colored.

[0031] In another example ("Example 26"), in addition to the device of Example 24, the interlocking strands are distinguishable from one another by markings.

[0032] In another example ("Example 27"), further to the device of Example 24, the interlocking strands are distinguishable from one another by texture. [Brief description of the drawings]

[0033] BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification, illustrate embodiments, and together with the description, serve to explain the principles of the disclosure.

[0034] [Figure 1] FIG. 1 is a top view of a delivery system including a catheter with a constraint, according to one embodiment.

[0035] [Diagram 2] FIG. 2 is a side view of an implantable medical device including a constraint, according to one embodiment.

[0036] [Diagram 3] FIG. 3 is a schematic diagram of interwoven strands according to one embodiment.

[0037] [Figure 4] 4A-4C are end views of a constraint showing exemplary knot row locations, according to one embodiment.

[0038] [Diagram 5] FIG. 5 is an end view of a constraint showing exemplary knot row locations, according to one embodiment.

[0039] [Figure 6A] FIG. 6A is an image of a delivery system in a delivery configuration, according to one embodiment.

[0040] [Figure 6B] FIG. 6B is an image of the delivery system shown in FIG. 6A in a semi-deployed configuration, according to one embodiment.

[0041] [Figure 7A] FIG. 7A is an end view of a constraint having an exemplary first knot row pattern, according to one embodiment.

[0042] [Figure 7B] FIG. 7B is an end view of the constraint shown in FIG. 7A having an exemplary second knot row pattern, according to one embodiment.

[0043] [Figure 8A] FIG. 8A is an end view of a constraint having an exemplary first knot row pattern, according to one embodiment.

[0044] [Figure 8B] FIG. 8B is an end view of the constraint shown in FIG. 8A with an exemplary second knot row pattern, according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0045] As the terms are used herein in reference to ranges of measurements, "about" and "approximately" can be used interchangeably to refer to measurements that include and can be reasonably close to the stated measurements, but can differ by a reasonably small amount as understood and readily ascertained by one of ordinary skill in the art that may result from measurement errors, differences in calibration of measuring and / or manufacturing equipment, human errors in reading and / or setting measurements, adjustments made to optimize performance and / or structural parameters given differences in measurements relative to other components, specific implementation scenarios, imprecise adjustment and / or manipulation of objects by humans or machines, and the like.

[0046] The foregoing examples are merely illustrative and should not be read to limit or otherwise narrow the scope of any of the inventive concepts otherwise provided by this disclosure. While multiple examples have been disclosed, still other embodiments will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative examples. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive in nature.

[0047] Detailed Description Those skilled in the art will readily appreciate that the various aspects of the disclosure may be implemented by any number of methods and devices configured to perform the intended functions. It should also be noted that the accompanying drawings referred to herein are not necessarily drawn to scale and may be exaggerated to illustrate various aspects of the disclosure, and in that regard, the drawings should not be construed as limiting.

[0048] Various aspects of the present disclosure are directed to devices, systems, and methods that include forming or manufacturing a constraint. The constraint mechanism is configured to hold, compress, or restrain an implantable medical device (e.g., a stent, stent graft, balloon, filter, or other expandable medical device) in a delivery configuration prior to and during delivery to a target location. In certain examples, the constraint comprises one or more fibers. In certain examples, the constraints disclosed herein allow for modification of the deployment characteristics of the implantable medical device prior to or during deployment of the device. Thus, the deployment system can be adapted to various situations that may occur during a procedure.

[0049] Figure 1 is a top view of a catheter 100 with a constraint 102, according to some embodiments. As shown in Figure 1, the constraint 102 is configured to constrain an implantable medical device 104 in a delivery configuration. The constraint 102 can include one or more fibers 106 disposed about the implantable medical device 104 to maintain the constraint 102 in the constrained configuration.

[0050] The constraint 102 is disposed along the length of the implantable medical device 104. The constraint 102 may also be disposed circumferentially around the implantable medical device 104 to substantially cover the implantable medical device 104 for delivery. The one or more fibers 106 may be disposed within a lumen (not shown) of the catheter 100 and may extend toward a proximal end of the catheter 100 that is disposed outside the patient during delivery of the implantable medical device 104. The one or more fibers 106 include a proximal end 108 to which a user may apply tension to release the constraint 102 and deploy the implantable medical device 104.

[0051] In certain instances, one or more of the fibers 106 are released similar to a ripcord, whereby the interlocking portions (e.g., overlapping fibers or knots) are released sequentially along the length of the implantable medical device 104. As described in more detail below, the constraint 102 is formed by interlocking one or more of the fibers 106 directly on the implantable medical device 104. In comparison to conventional multiple fiber constraints that are woven together and then placed around a constraining device, the constraint 102 is formed directly on the implantable medical device 104. The expandable medical device 104 can be a stent, stent graft, balloon, or similar device.

[0052] 2 is a side view of a device 104 including a constraint 102, according to one embodiment. As shown, the device 104 includes a delivery diameter D1 and a deployed diameter D2 (not shown) that is larger than the delivery diameter D1. A removable constraint 102 is attached to the device 104 at its delivery diameter D1. As shown, the constraint 102 includes at least two interlocking strands in a warp knit form. For example, the constraint 102 can include a first interlocking strand 110 and a second interlocking strand 112. The first interlocking strand 110, 112 can operate as a deployment line 120 (which can be coupled to one or more knot rows 114, as discussed in more detail below) configured to release the constraint 102 and transition the device 104 from the delivery diameter D1 to the deployed diameter D2 in response to a force applied to the deployment line 120, for example.

[0053] The device 104 can have a desired deployed diameter D2, for example, between about 5 mm and 15 mm, or between 6 mm and 9 mm, or between 6 mm and 12 mm, and a delivery diameter D1 that is smaller than the deployed diameter D2. For example, in some instances, the ratio of the delivery diameter D1 of the device 104 to the deployed diameter D2 (not shown) of the device 104 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. For reference, the term "diameter" is not intended to require a circular cross-section, but instead should be understood broadly to refer to the maximum cross-sectional dimension of the device 104.

[0054] 3 is a schematic diagram of interlocking strands according to one embodiment. As shown, the interlocking strands are interwoven with one another in a warp knit pattern to form a row of knots 114 (e.g., a first interlocking strand 110 is interwoven with a second interlocking strand 112 to form a first row of knots 114a, etc.). As shown, in some examples, the restraint 102 can include more than two interlocking strands. For example, the restraint 102 can also include a third interlocking strand 116 and a fourth interlocking strand 118. Similar to the first two interlocking strands 110, 122, the second interlocking strand 112 can be interwoven with a third interlocking strand 116 to form a second row of knots 114b, which can then be interwoven with a fourth interlocking strand 118 to form a third row of knots 114c. Additional rows 114 may be similarly formed with additional interlocking strands. Although the restraint 102 is described above with reference to two, three, and four interlocking strands and corresponding knot rows, the restraint 102 may have any number of interlocking strands and knot rows, as desired. For example, the restraint 102 may include three, five, six, seven, eight, or more interlocking strands and respective knot rows 114.

[0055] In various examples, the knot rows 114 are configured to deploy or unravel at different deployment rates. In certain examples, the knot rows 114 are configured to deploy or unravel at different deployment rates due to positioning of the knot rows around the restraint 102. The deployment ratio is the ratio of the deployment rate of one knot row 114 to that of another knot row 114. Column It can be compared to the deployment speed.

[0056] 4A-4C are end views of the constraint 102 illustrating the positioning of an exemplary knot row 114, according to one embodiment. The knot rows 114 may be spaced any amount around the circumference of the constraint 102, as desired. For example, the knot rows 114 may be evenly spaced around the circumference of the constraint 102, or may be unevenly spaced around the circumference of the constraint 102.

[0057] 4A, in some examples, the knot rows 114 may be spaced apart from one another by approximately 90 degrees. For example, if there are four knot rows (e.g., first through fourth knot rows 114a-d), each knot row 114a-d may be spaced apart by 90 degrees. For example, the first knot row 114a may be spaced apart by 90 degrees from the second knot row 114b, which may be spaced apart by 90 degrees from the third knot row 114c, and each knot row 114a-d may be spaced apart by 90 degrees. In these examples, the deployment ratio of each knot row to the adjacent knot row is approximately 15:1 (e.g., the deployment ratio of the first knot row 114a to the second knot row 114b is approximately 15:1, and the deployment ratio of the second knot row 114b to the third knot row 114c is approximately 15:1).

[0058] 4B illustrates a constraint 102 having non-uniformly spaced knot rows 114 with various deployment ratios. As shown, the first and second knot rows 114a, 114b may be spaced approximately 180 degrees apart from one another around the circumference of the constraint 102. The second and third knot rows 114b, 114c and the third and fourth knot rows 114c, 114d may be spaced approximately 60 degrees apart from one another. Thus, the deployment ratio between the second and third knot rows 114b, 114c and the third and fourth knot rows 114c, 114d is approximately 10:1. In these examples, the deployment ratio of the first knot row 114a to the second knot row 114b is greater than the deployment ratio of the second knot row 114b to the third knot row 114c, and the deployment ratio of the third knot row 114c to the fourth knot row 114d. Thus, the first and second knot rows 114a, 114b deploy slower and the remaining knot rows (e.g., the third and fourth knot rows 114c, 114d) deploy faster.

[0059] In certain instances, the constraint 102 may have fewer than five knot rows 114, as shown, which are unevenly spaced from one another along the circumference of the constraint 102. For example, the constraint 102 may have three knot rows 114 (e.g., as shown in FIG. 8A ), seven knot rows 114, nine knot rows 144, or another odd number of rows that are unevenly spaced from one another along the circumference of the constraint 102. As noted above, the deployment ratio of the constraint 102 may be altered based on a user's perturbation of strands of a particular knot row 114, which may have different deployment ratios.

[0060] 4C illustrates a constraint 102 having six knot rows 114 (e.g., first knot row 114a, second knot row 114b, third knot row 114c, fourth knot row 114d, fifth knot row 114e, and sixth knot row 114f) evenly spaced around the circumference of the constraint 102. The knot rows 114 are spaced approximately 60 degrees apart from one another. For example, the first knot row 114a is spaced approximately 60 degrees from the second knot row 114b, the second knot row 114b is spaced approximately 60 degrees from the third knot row 114c, etc. In these examples, the knot rows 114 have a deployment ratio of approximately 10:1. In other words, the ratio of the deployment rate of the first knot row 114a to the deployment rate of the second knot row 114b is approximately 10:1, and the ratio of the deployment rate of the second knot row 114b to the deployment rate of the third knot row 114c is approximately 10:1.

[0061] In various examples, disturbing the strands of the first knot row 114a initiates unravelling of at least a portion of the restraint 102 at a first deployment rate associated with the first knot row 114a. Disturbing the strands of the second knot row 114b initiates unravelling of at least a portion of the restraint 102 at a second deployment rate associated with the second knot row 114b. The first and second deployment rates of the first and second knot rows 114a, 114b, respectively, can be the same or different, depending on the positioning of the knot rows 114 around the restraint 102 and their respective deployment ratios. For example, the first deployment rate can be faster than the second deployment rate, while in other examples, the second deployment rate is faster than the first deployment rate.

[0062] In various examples, disturbing a strand of a knot row 114 to initiate the unraveling of the knot row 114 may include breaking the strand, applying a force to the strand, or changing the tension on the strand. In certain examples, a first knot row 114a may be configured to disturb and unravel before a second knot row 114b and / or any number of subsequent knot rows 114.

[0063] 5 is an end view of the restraint 102 illustrating the deployment of an exemplary knot row 114, according to one embodiment. In some examples, each interlocking strand and knot row is configured to be selectively unraveled by a user. For example, as shown, when one of the interlocking strands of the first knot row 114a (e.g., the first interlocking strand 110) is disturbed, the first knot row 114a is unraveled at a first deployment speed and a portion of the restraint 102 is released. After initiating the unraveling of the first knot row 114a, one of the interlocking strands of the second knot row 114b (e.g., the second interlocking strand 112) can be disturbed by a user, thus initiating the unraveling of the second knot row 114b and the release of another portion of the restraint 102 at a second deployment speed. After initiating the unravelling of the second knot row 114b, one of the interlocking strands of the third knot row 114c (e.g., third interlocking strand 116) can be disturbed by the user, thus initiating the unravelling of the third knot row 114c and the release of another portion of the restraint 102 at a third deployment speed. After initiating the unravelling of the third knot row 114c, one of the interlocking strands of the fourth knot row (e.g., fourth interlocking strand 118) can be disturbed by the user, thus initiating the unravelling of the fourth knot row 114d and the release of another portion of the restraint 102 at a fourth deployment speed. This release method can be continued for successive knot rows until the restraint 102 is fully released. In other examples, disturbing one of the rows 114 can independently release the restraint 102, allowing a user to change the deployment ratio based on the knot row 114 selection.

[0064] In various examples, a user can actively select which knot rows 114 to deploy at a particular time. For example, the knot rows 114 need not be deployed sequentially around the device 104. For example, the first knot row 114a can be deployed first, followed by the third or fourth knot rows 114c, 114d. Each knot row 114 can have different deployment characteristics (e.g., deployment speed, deployment ratio) so that a user can purposefully deploy the knot row 114 that provides the deployment characteristics desired during a procedure.

[0065] In some examples, the interlocking strands of the first knot row 114a can be distinguishable from the interlocking strands of the second knot row 114b. For example, the interlocking strands of the first knot row and the second knot row 114a, 114b can have different strand characteristics, such as color, markings, and / or texture. For example, one of the first knot row and the second knot row 114a, 114b can include a first color and the other of the first knot row and the second knot row 114a, 114b can include a second color. The different colors of the first knot row and the second knot row 114a, 114b indicate to a user that the first knot row and the second knot row 114a, 114b have different deployment rates. Additionally, one of the first knot row and the second knot row 114a, 114b can include a first mark (e.g., a visual indicator) and the other of the first knot row and the second knot row 114a, 114b can include a second mark. The different markings of the first knot row and the second knot row 114a, 114b indicate to a user that the first knot row and the second knot row 114a, 114b have different deployment speeds. In another example, one of the first knot row and the second knot row 114a, 114b can include a first texture and the other of the first knot row and the second knot row 114a, 114b can include a second texture. The different textures of the first knot row and the second knot row 114a, 114b indicate to a user that the first knot row and the second knot row 114a, 114b have different deployment speeds. In any of these cases, each additional row of constraints 102 may include different strand characteristics, such as color, markings, and / or texture. In this manner, for rows having different deployment rates, a user may select a removal rate of the constraints 102. For example, multiple knot rows may be configured to be perturbed in response to a user selection of one of the multiple rows, allowing a user to select a removal rate of the constraint. In certain instances, the multiple rows are configured to unravel in a set sequence to define a removal rate of the constraint.Potential materials for the interlocking strands discussed herein include, for example, fluoropolymers such as polytetrafluoroethylene (PTFE), expanded polytetrafluoroethylene (ePTFE), polyester, polyurethane, perfluoroelastomers, polytetrafluoroethylene, silicone, urethane, ultra-high molecular weight polyethylene, aramid fibers, and combinations thereof. Other embodiments of the interlocking strands can include high strength polymer fibers such as ultra-high molecular weight polyethylene fibers (e.g., Spetra®, Dyneema Purity®, etc.) or aramid fibers (e.g., Technora®, etc.). In general, any of the above properties can be evaluated using ASTM or other recognized measurement techniques and standards, as will be appreciated by those skilled in the art.

[0066] 6 is a side view of a delivery system including the device 104 and the restraint 102, according to one embodiment. In some instances, the interlocking strands (e.g., first interlocking strand 110 and second interlocking strand 112) are configured to reduce the tilt of the device 104 before being released. For example, the interlocking strands can reduce the tilt of the device 104 before the knots in the knot row 114 are sequentially released. As shown in FIG. 6, the device 104 begins to expand to a larger diameter after the restraining mechanism 102 is released. The device 104 can have an angle A between the portion held by the restraining mechanism 102 and the expanded or beginning to expand portion. Due to the angle A and the fact that the device 104 is expending force to expand to the deployed diameter D2, conventional devices may shift due to the tilt of the device 104. However, the interlocking strands reduce tilting of the device 104 by maintaining the position of each knot relative to the device 104 as the knots in the knot row 114 are released sequentially, reducing undesired or pre-deployment of the device 104, as shown in FIG. 6.

[0067] Figure 6A is an image of the delivery system 10 in a delivery configuration, according to one embodiment. Figure 6B is an image of the delivery system 10 in a semi-deployed configuration, according to one embodiment. As shown, disturbing one of the interlocking strands of the first knot row 114a (e.g., first interlocking strand 110) initiates unravelling of at least a portion of the restraint 102 at a first deployment rate, as shown in Figure 6B. Disturbing one of the interlocking strands of the second knot row 114b (not shown in Figures 6A and 6B) initiates unravelling of another portion of the restraint 102 at a second deployment rate. In examples where the constraint 102 includes more than two knot rows, disturbing a strand of a successive knot row (e.g., the third knot row 114c and / or the fourth knot row 114d) initiates the unraveling of another portion of the constraint 102 at another deployment rate (e.g., a third deployment rate or a fourth deployment rate) that can be different or the same as the first deployment rate and / or the second deployment rate. In other examples, disturbing one of the rows 114 can independently release the constraint 102, and a user can change the deployment ratio based on the selection of the knot row 114.

[0068] 7A is an end view of a constraint 102 having an exemplary first knot row pattern, according to one embodiment. The constraint 102 includes different patterns formed by multiple interlocking strands 110, 112, 116, 118 along the length of the constraint. As described in more detail below, the patterns differ based on the interactions between the interlocking strands 110, 112, 116, 118 along the length of the constraint 102.

[0069] In some examples, each interlocking strand and knot row is configured to be selectively unraveled by a user. For example, as shown, when one of the interlocking strands of the first knot row 114a (e.g., first interlocking strand 110) is disturbed, the first knot row 114a is unraveled at a first deployment speed and a portion of the restraint 102 is released. After initiating the unraveling of the first knot row 114a, one of the interlocking strands of the second knot row 114b (e.g., second interlocking strand 112) can be disturbed by a user, thus initiating the unraveling of the second knot row 114b at a second deployment speed and the release of another portion of the restraint 102. After initiating the unravelling of the second knot row 114b, one of the interlocking strands of the third knot row 114c (e.g., third interlocking strand 116) can be disturbed by the user, thus initiating the unravelling of the third knot row 114c at a third deployment speed and initiating the release of another portion of the restraint 102. After initiating the unravelling of the third knot row 114c, one of the interlocking strands of the fourth knot row (e.g., fourth interlocking strand 118) can be disturbed by the user, thus initiating the unravelling of the fourth knot row 114d at a fourth deployment speed and initiating the release of another portion of the restraint 102. This release method can be continued for successive knot rows until the restraint 102 is fully released. In other examples, disturbing one of the rows 114 can independently release the restraint 102, allowing a user to change the deployment ratio based on the knot row 114 selection.

[0070] In various examples, a user can actively select which knot row 114 to deploy at a particular time. For example, the knot rows 114 need not be deployed sequentially around the device 104. For example, the first knot row 114a can be deployed first, followed by the third knot row or the fourth knot row 114c, 114d. Each of the knot rows 114 can have different deployment characteristics (e.g., deployment speed, deployment ratio) so that a user can purposefully deploy the knot row 114 that provides the desired deployment characteristics during a procedure. In another example, as shown in FIG. 7B, the constraint 102 can be formed, woven or knitted to have a multiple knot row pattern along the length of the constraint.

[0071] 7B is an end view of the restraint 102 shown in FIG. 7A with an exemplary second knot row pattern, according to one embodiment. As shown in FIG. 7B, the positions of the third interlocking strand 116 and the fourth interlocking strand 118 have been swapped relative to the circumference of the restraint 102.

[0072] Varying the position of the third interlocking strand 116 and the fourth interlocking strand 118 also forms different knot rows 114e, 114f instead of knot rows 114c, 114d. In certain examples, the third interlocking strand 116 and the fourth interlocking strand 118 are altered at a point along the length of the restraint 102 to change or vary the deployment ratio. The interaction between the third interlocking strand 116 and the first interlocking strand 110 can be different than the interaction between the fourth interlocking strand 118 and the first interlocking strand 110. Similarly, the interaction between the fourth interlocking strand 118 and the second interlocking strand 112 can be different than the interaction between the third interlocking strand 116 and the second interlocking strand 112.

[0073] The positions of the interlocking strands 110, 112, 116, 118 can be switched to create a constraint 102 that has different deployment ratios within the knot row 114 and can further vary along the length of the constraint 102. As a result, a user perturbing one of the knot rows 114 can change the strand positions and alter the interactions between the strands. By , the deployment can be passively altered while continuing to perturb that one of the knot rows 114. For example, if a user deploys downward and knot row 114d is configured to include a first deployment force, and a different deployment force is desired after a certain length of deployment, the positions of third interlocking strand 116 and fourth interlocking strand 118 can be changed in place to replace knot row 114d with knot row 114e, which may be configured to include a different (e.g., higher or lower) deployment force. Similarly, interlocking strands 110, 112, 116, 118 can be merged or split as described below with reference to Figures 8A-B.

[0074] 8A is an end view of a constraint 102 having an exemplary first knot row pattern, according to one embodiment. The constraint 102 includes different patterns formed by multiple interlocking strands 110, 112, 116 along the length of the constraint. As described in more detail below, the patterns differ based on an increase or decrease in the knot row 114 along the length of the constraint 102.

[0075] In some examples, each interlocking strand and knot row is configured to be selectively unraveled by a user. For example, as shown, when one of the interlocking strands of the first knot row 114a (e.g., first interlocking strand 110) is disturbed, the first knot row 114a is unraveled at a first deployment rate and a portion of the restraint 102 is released. After initiating the unraveling of the first knot row 114a, one of the interlocking strands of the second knot row 114b (e.g., second interlocking strand 112) can be disturbed by a user, thus initiating the unraveling of the second knot row 114b at a second deployment rate and the release of another portion of the restraint 102. After initiating the unravelling of the second knot row 114b, one of the interlocking strands of the third knot row 114c (e.g., the third interlocking strand 116) can be disturbed by the user, thus initiating the unravelling of the third knot row 114c at a third deployment rate and initiating the release of another portion of the restraint 102. This release method can continue for successive knot rows until the restraint 102 is fully released. In other examples, disturbing one of the rows 114 can independently release the restraint 102, and the user can change the deployment ratio based on the selection of the knot row 114.

[0076] In various examples, a user can actively select which knot rows 114 to deploy at a particular time. For example, the knot rows 114 need not be deployed sequentially around the device 104. Each knot row 114 can have different deployment characteristics (e.g., deployment speed, deployment ratio), and a user can purposefully deploy a knot row 114 that provides the desired deployment characteristics during a procedure.

[0077] The restraint 102 can have different deployment ratios within the knot rows 114 along the length of the restraint 102. Rather than switching positions of the interlocking strands 110, 112, 116, the interlocking strands 110, 112, 116 merge to create different interactions between the interlocking strands 112, 116, 118. For example, the second interlocking strand 112 and the third interlocking strand 116 are merged, as shown in FIG. 8B. The merging of the second interlocking strand 112 and the third interlocking strand 116 creates different knot rows and knot patterns. For example, the merging of the second interlocking strand 112 and the third interlocking strand 116 would rather form two knot rows 114e, 114f. The combination of second interlocking strand 112 and third interlocking strand 116 creates different interactions within restraint 102 than second interlocking strand 112 and third interlocking strand 116 alone.

[0078] The merging of interlocking strands 110, 112, 116 (or conversely, splitting of the strands) can create a constraint 102 that has different deployment ratios within knot row 114 and can further vary along the length of the constraint 102. As a result, a user who disturbs one of knot rows 114 can continue to disturb that one of knot rows 114 while changing strand positions and changing interactions between the strands. By, the deployment can be passively altered. For example, if a user deploys downward and knot row 114a is configured to include a first deployment force, but a different deployment force is desired after a certain length of deployment, second interlocking strand 112 and third interlocking strand 116 can merge in place and replace knot row 114a with knot row 114d or knot row 114e, which can be configured to include a different (e.g., higher or lower deployment force). Interlocking strands 110, 112, 116 can be split rather than merged. For example, restraint 102 can start with the pattern shown in FIG. 8B and transition to the pattern shown in FIG. 8A.

[0079] As discussed above with reference to Figures 7-8, merging, repositioning, or splitting of interlocking strands may occur using any number of interlocking strands. For example, interlocking strands 110, 112, 116, and 118 may be merged to form two knot rows, and the opposing two knot rows 114 may become four knot rows 114. Additionally, three knot rows 114 may be repositioned as described with reference to Figures 7A-B.

[0080] In certain examples, the knot row 114 can include multiple pairs of strands, or pairs of strands, or a single strand, as described in detail above. Multiple strands can be arranged or braided together and then interlocked with one or more other strands to form the knot row 114 (e.g., strands 112, 116 interlocked with strand 110 as shown in FIG. 8B). The knot row 114 can include strands so arranged along the entire length of the restraint 102, or along only a portion of its length as described with reference to FIG. 8B.

[0081] The inventive concept of this application has been described above both generally and with reference to specific embodiments. It will be apparent to those skilled in the art that various modifications and variations can be made in the embodiments without departing from the scope of the present disclosure. Accordingly, the embodiments are intended to cover modifications and variations of the inventive concept provided they come within the scope of the appended claims and their equivalents. (Aspect) (Aspect 1) A medical device deployment apparatus, comprising: a restraint configured to releasably restrain a medical device, the restraint including a plurality of interlocking strands forming a first row of knots configured to unravel at a first deployment rate and a second row of knots configured to unravel at a second deployment rate different from the first deployment rate; A medical device deployment apparatus, wherein disturbing the strands of the first knot row initiates unravelling of at least a portion of the restraint at the first deployment rate, and disturbing the strands of the second knot row initiates unravelling of at least a portion of the restraint at the second deployment rate. (Aspect 2) 2. The device of embodiment 1, wherein a deployment ratio between the first knot row and the second knot row is 10:1. (Aspect 3) 3. The apparatus of any one of aspects 1-2, further comprising a third knot row spaced apart from the first knot row and the second knot row, wherein disturbing the strands of the third knot row initiates unravelling of at least a portion of the constraint at a third deployment rate, different from the first deployment rate and the second deployment rate. (Aspect 4) 4. The apparatus of claim 3, wherein a deployment ratio between the first knot row and the second knot row is different from a deployment ratio between the second knot row and the third knot row. (Aspect 5) 5. The device of embodiment 4, wherein the first row of knots, the second row of knots, and the third row of knots are equally spaced around a circumference of the restraint. (Aspect 6) 5. The device of embodiment 4, wherein the first row of knots, the second row of knots, and the third row of knots are non-uniformly spaced around the circumference of the restraint. (Aspect 7) 7. The apparatus of any one of claims 1-6, wherein disrupting the first knot row comprises breaking a strand of the first knot row and disrupting the second knot row comprises breaking a strand of the second knot row. (Aspect 8) 8. The apparatus of any one of claims 1-7, wherein disturbing the first knot row comprises altering a tension in at least one strand of the first knot row and disturbing the second knot row comprises altering a tension in at least one strand of the second knot row. (Aspect 9) 9. The device of any one of the preceding claims, wherein the first knot row is configured to be disrupted prior to the second knot row. (Aspect 10) 10. The device of any one of aspects 1 to 9, wherein the second deployment speed is faster than the first deployment speed. (Aspect 11) 11. The device of any one of claims 1-10, wherein the strands of the first row of knots are distinguishable from the strands of the second row of knots by color. (Aspect 12) 12. The device of any one of the preceding claims, wherein the strands of the first knot row are distinguishable from the strands of the second knot row by markings. (Aspect 13) 13. The device of any one of claims 1-12, wherein the strands of the first row of knots are distinguishable from the strands of the second row of knots by texture. (Aspect 14) 14. The apparatus of any one of claims 1-13, wherein the plurality of interlocking strands form a warp knit pattern. (Aspect 15) 15. The device of any one of embodiments 1-14, wherein the pattern formed by the plurality of interlocking strands varies along the length of the restraint. (Aspect 16) 16. The device of claim 15, wherein the plurality of interlocking strands form a plurality of knot rows, including the first knot row and the second knot row, that increase or decrease in number along the length of the restraint. (Aspect 17) 16. The device of claim 15, wherein the plurality of interlocking strands form a plurality of knot rows including the first knot row and the second knot row, and wherein an interaction between the plurality of interlocking strands varies along a length of the restraint. (Aspect 18) 1. A method of using a medical device deployment apparatus, comprising: providing a restraint including a first knot row and a second knot row; disrupting strands of the first knot row to initiate unraveling of at least a portion of the restraint at a first deployment rate; and disturbing strands of the second knot row to initiate unraveling of at least a portion of the constraint at a second deployment rate greater than the first deployment rate; A method comprising: (Aspect 19) 20. The method of embodiment 18, further comprising perturbing strands of a third knot row to unravel at least a portion of the constraint at a third deployment rate different from the first deployment rate and the second deployment rate. (Aspect 20) 20. The method of any one of claims 18-19, wherein disrupting the strands of the first knot row comprises breaking the strands. (Aspect 21) a removable restraint having a perimeter and including a plurality of interlocking strands in a warp knit configuration having a plurality of spaced rows of knots about the perimeter; when one of the knot trains is disturbed, the removable restraint becomes unraveled and remotely removable when a force is applied to the deployment line; and An apparatus for deploying a medical device, wherein the plurality of knot rows are non-uniformly distributed about the circumference, and a rate of removal of the removable restraint varies depending on which knot row is disturbed. (Aspect 22) 22. The apparatus of claim 21, wherein the plurality of knot rows are configured to be perturbed in response to a user selecting one of the plurality of rows such that the user can select a rate of restraint removal. (Aspect 23) 23. The apparatus of any one of aspects 21-22, wherein the plurality of rows are configured to disentangle in a set sequence to define a rate of restraint removal. (Aspect 24) 23. The device of any one of embodiments 21-22, wherein the interlocking strands are distinguishable from one another. (Aspect 25) 25. The device of claim 24, wherein the interlocking strands are distinguishable from one another by being colored. (Aspect 26) 25. The device of embodiment 24, wherein the interlocking strands are distinguishable from one another by markings. (Aspect 27) 25. The device of embodiment 24, wherein the interlocking strands are distinguishable from one another by texture.

Claims

1. A medical device deployment apparatus, comprising: a restraint configured to releasably restrain a medical device, the restraint including a plurality of interlocking strands forming a first row of knots disposed at a first portion around the restraint and configured to unravel at a first deployment rate, and a second row of knots disposed at a second portion around the restraint and configured to unravel at a second deployment rate different from the first deployment rate; A medical device deployment apparatus, wherein disturbing the strands of the first knot row initiates unravelling of at least a portion of the restraint at the first deployment rate, and disturbing the strands of the second knot row initiates unravelling of at least a portion of the restraint at the second deployment rate.

2. 2. The apparatus of claim 1, wherein a ratio of deployment speed of the first knot row to the second knot row is 10.

3. 3. The device of claim 1, further comprising a third knot row spaced apart from the first knot row and the second knot row, wherein disturbing strands of the third knot row initiates unraveling of at least a portion of the restraint at a third deployment rate different than the first deployment rate and the second deployment rate.

4. 4. The apparatus of claim 3, wherein a ratio of deployment rates between the first knot row and the second knot row is different than a ratio of deployment rates between the second knot row and the third knot row.

5. 5. The apparatus of claim 4, wherein the first row of knots, the second row of knots and the third row of knots are equally spaced around a circumference of the restraint.

6. 5. The apparatus of claim 4, wherein the first row of knots, the second row of knots and the third row of knots are non-uniformly spaced around a circumference of the restraint.

7. 7. The apparatus of any one of claims 1-6, wherein disrupting the first knot train comprises breaking a strand of the first knot train and disrupting the second knot train comprises breaking a strand of the second knot train.

8. 8. The apparatus of any one of claims 1-7, wherein disturbing the first knot row comprises altering a tension in at least one strand of the first knot row and disturbing the second knot row comprises altering a tension in at least one strand of the second knot row.

9. The device of any one of claims 1 to 8, wherein the first knot row is configured to disrupt before the second knot row.

10. The device of claim 1 , wherein the second deployment speed is faster than the first deployment speed.

11. The apparatus of any one of claims 1 to 10, wherein the strands of the first knot row are distinguishable from the strands of the second knot row by color.

12. The apparatus of any one of claims 1 to 11, wherein the strands of the first knot row are distinguishable from the strands of the second knot row by markings.

13. 13. The apparatus of claim 1, wherein the strands of the first knot row are distinguishable from the strands of the second knot row by texture.

14. The apparatus of any one of claims 1 to 13, wherein the plurality of interlocking strands form a warp knit pattern.

15. The apparatus of any preceding claim, wherein the pattern formed by the plurality of interlocking strands varies along the length of the restraint.

16. 16. The device of claim 15, wherein the plurality of interlocking strands form a plurality of knot rows, including the first knot row and the second knot row, that increase or decrease in number along the length of the restraint.

17. a restraint removable from the medical device, the restraint including a plurality of interlocking strands in a warp knit configuration having a perimeter and a plurality of rows of knots spaced apart about the perimeter; when one of the knot rows is disturbed, the removable restraint unravels when a force is applied to the deployment line; and An apparatus for deploying a medical device, wherein the plurality of knot rows are non-uniformly distributed about the circumference, and a rate of removal of the removable restraint from the medical device varies depending on which knot row is disturbed.

18. 20. The apparatus of claim 17, wherein the plurality of knot rows are configured to be perturbed in response to a user selecting one of the plurality of rows to allow the user to select a rate of restraint removal.

19. An apparatus according to any one of claims 17 to 18, wherein the plurality of rows are configured to unravel in a set sequence to define a rate of restraint removal.

20. The device of any one of claims 17 to 18, wherein the interlocking strands are distinguishable from one another.

21. 21. The device of claim 20, wherein the interlocking strands are distinguishable from one another by being colored.

22. 21. The apparatus of claim 20, wherein the interlocking strands are distinguishable from one another by markings.

23. 21. The device of claim 20, wherein the interlocking strands are distinguishable from one another by texture.

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