Abstract:
An apparatus for gripping a balloon catheter during folding (i.e., fluting) is provided. The apparatus includes a base unit, a back gripper and a front gripper. The front gripper is configured to straighten an inner lumen of the balloon catheter. A method for gripping a balloon catheter during fluting is also provided. The method can include the steps of straightening an inner lumen of the balloon catheter and aligning the inner lumen with a central axis when straightened. The method further can include the steps of providing a plurality of arms coupled to the base unit and arranged in a pattern about a central axis, translating the plurality of arms in a radial direction toward and away from the central axis, fluting the balloon catheter with a plurality of blades coupled to the plurality of arms.

Description:
INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS 
       [0001]    Any and all applications for which a foreign or domestic priority claim is identified in the Application Data Sheet as filed with the present application are hereby incorporated by reference under 37 CFR 1.57, including but not limited to U.S. Prov. Pat. App. No. 61/817,802 filed on Apr. 30, 2013. 
     
    
     BACKGROUND 
       [0002]    1. Field 
         [0003]    The present invention generally relates to balloon catheters. More particularly, the present invention relates to devices and methods used to grip a balloon catheter and/or guide wire during fluting. 
         [0004]    2. Description of the Related Art 
         [0005]    A balloon catheter generally comprises an inflatable balloon that is mounted along a distal end of an elongate catheter body (e.g., a shaft). Balloon catheters are used by physicians in a wide variety of therapeutic procedures. In one common use, a folded balloon catheter is advanced through a blood vessel to a region that has become occluded by atherosclerotic plaque. The balloon is inflated to dilate the occluded region and thereby improve the flow of blood through the vessel. In another common use, an expandable stent is provided along the exterior of the balloon. The balloon is advanced to the treatment site and is then inflated to deploy the stent. The balloon is then deflated and the balloon catheter is withdrawn from the patient. The expanded stent remains in the blood vessel to provide support to the vessel wall. 
         [0006]    Balloon catheters are typically formed of a very thin, yet strong material. During manufacture, a balloon catheter is folded at a number of locations along its longitudinal axis. After the balloon is folded in a variety of locations, the folds are wrapped around the catheter to reduce the balloon to a constrained condition having a very small diameter. In the case wherein the balloon is used to deploy a stent, the stent is crimped onto the balloon after the folding step. The balloon is advanced through the blood vessel to a treatment site while in the constrained condition. The balloon is inflated by directing a fluid through a lumen in the catheter to pressurize the balloon. During inflation, the balloon unfolds, rather than stretches. Embodiments of the present invention enable a balloon catheter to radially expand in a very predictable manner. 
       SUMMARY 
       [0007]    Embodiments of the present invention disclosed herein provide improved devices and methods for gripping a balloon catheter during fluting. The embodiments facilitate the manufacture of balloon catheters while minimizing costs and providing a balloon catheter that expands in a reliable and predictable manner. Further, the embodiments provide a modular unit that is capable of gripping balloon catheters of a variety of different sizes and shapes. 
         [0008]    In some embodiments, a desirable feature for balloon catheters is a small profile so as to be able to use the smallest introducer possible. In addition to the design of the catheter, e.g., proximal neck outer diameter and balloon wall thickness, the fluting and wrapping of the balloon around the shaft can play a significant role. The inner lumen traversing the length of the balloon catheter may not be well centered during the fluting process. This offset between the center axis of the fluter system and the inner lumen of the balloon catheter can lead to uneven flutes, a poor wrap and/or catheter damage. 
         [0009]    The length of the inner lumen relative to the length of the balloon catheter typically varies due to differences in design and different compliances during inflation. The unsupported inner lumen of the balloon catheter can become bowed or adopt a serpentine shape within the balloon. For balloon catheters designed for use with larger diameter guide wires, for example 0.018″ or larger diameter guide wires (e.g., 0.035″ diameter guide wires), the bowing may not be as significant since a guide wire or stylet of similar size is typically used during fluting. The larger diameter guide wires, in some cases, provide sufficient stiffness so as to straighten out the inner lumen of the balloon catheter. However, for balloon catheters designed for use with smaller diameter guide wires, for example 0.014″ or smaller diameter guide wires (e.g., 0.010″ diameter guide wires, or no more than about 0.016″, 0.015″, 0.014″, 0.013″, 0.012″, 0.011″, 0.010″, 0.009″, 0.008″ or less in diameter guide wires), the stiffness of the guide wire can be insufficient to provide enough support. The smaller diameter guide wires, in some cases, do not provide sufficient stiffness so as to straighten out the inner lumen and/or the balloon catheter. The issue of bowing is further complicated by the ever increasing length of balloons, with some manufacturers offering 200-300 mm length balloons or more, or at least 150 mm, 175 mm, 200 mm, 225 mm, 250 mm, 275 mm, 300 mm, 325 mm, 350 mm, 375 mm, 400 mm, or more. With these longer lengths, the extent of bowing of the inner lumen of the balloon catheter increases significantly. 
         [0010]    In one embodiment, an apparatus for gripping a balloon catheter during folding (i.e., fluting) is provided. The apparatus includes a base unit, a first, e.g., back gripper and a second, e.g., front gripper. The back gripper is removably coupled to a first portion of a balloon catheter. The front gripper is removably coupled to a second portion of the balloon catheter. The front gripper is configured to straighten an inner lumen of the balloon catheter. The inner lumen aligns with a central axis when straightened. A plurality of arms is coupled to the base unit and arranged in a pattern about the central axis. The plurality of arms can translate in a radial direction toward and away from the central axis. A plurality of blades can be coupled to the plurality of arms such that the plurality of blades can engage the balloon catheter during fluting. 
         [0011]    A method for gripping a balloon catheter during fluting is also provided. Such method can include the steps of providing a device having a base unit, a back gripper and a front gripper; removably coupling the back gripper to a first portion of a balloon catheter; removably coupling the front gripper to a second portion of the balloon catheter. The method further can include the steps of straightening an inner lumen of the balloon catheter; aligning the inner lumen with a central axis when straightened. The method further can include the steps of providing a plurality of arms coupled to the base unit and arranged in a pattern about the central axis; translating the plurality of arms in a radial direction toward and away from the central axis; fluting the balloon catheter with a plurality of blades coupled to the plurality of arms. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    These and other features, aspects, and advantages will now be described in connection with some embodiments of the invention in reference to the accompanying drawings. The illustrated embodiments, however, are merely examples and are not intended to limit the invention. The drawings include the following fourteen figures. 
           [0013]      FIG. 1  is a perspective view of a balloon catheter having a straight inner lumen, according to some embodiments of the invention. 
           [0014]      FIG. 2  is a cross-sectional view of the balloon catheter of  FIG. 1 . 
           [0015]      FIG. 3  is a cross-sectional view of the balloon catheter of  FIG. 1  with flutes. 
           [0016]      FIG. 4  is a perspective view of a balloon catheter having a bowed inner lumen, according to some embodiments of the invention. 
           [0017]      FIG. 5  is a cross-sectional view of the balloon catheter of  FIG. 4 . 
           [0018]      FIG. 6  is a cross-sectional view of the balloon catheter of  FIG. 4  with flutes. 
           [0019]      FIG. 7A  is a front elevational view of a fluter system, according to some embodiments of the invention, showing a plurality of arms and a plurality of blades disposed about a central axis such that each of the plurality of arms and each of the plurality of blades is capable of translating toward the central axis and away from the central axis;  FIG. 7B  is another view of the fluter system of  FIG. 7A . 
           [0020]      FIG. 8  is a front view of a back gripper, according to some embodiments of the invention. 
           [0021]      FIG. 9  is a perspective view of a back gripper. 
           [0022]      FIG. 10  is a side view of a front gripper, according to some embodiments of the invention. 
           [0023]      FIG. 11  is a side view of a gripping system, according to some embodiments of the invention. 
           [0024]      FIG. 12  is a side view of a gripping system with a balloon catheter. 
       
    
    
     DETAILED DESCRIPTION 
       [0025]    Disclosed herein are systems and methods to advantageously straightening the balloon catheter and/or inner lumen during the fluting process. In some embodiments, disclosed is a first, e.g., back gripper that centers and grabs the one or more supporting guide wires. On another portion of the balloon catheter, a second, e.g., front gripper supporting the catheter shaft is centered, such as on the same axis as the back gripper. With the shaft centered, the operator can provide tension, straightening the guide wire, by, for example, either pulling directly on the guide wire or grasping it through the catheter shaft. Once there is sufficient tension, the fluting process can be initiated and the inner lumen can be centered within the flutes. 
         [0026]    In some embodiments, a modification to this approach is to add a tensioner, e.g., as a function of the front gripper, the back gripper, or a separate component. With this approach the guide wire can be grabbed by the front gripper, directly or indirectly, and tension applied by the tensioner. Any of the grippers, such as the front gripper and/or the back gripper, can be pneumatic, mechanical and/or electrical, as well as the tensioner. 
         [0027]    Once the fluting is completed, the balloon can be kept under vacuum to maintain the flutes and centering of the inner lumen. The balloon catheter is transferred to a wrapping station or manually wrapped (use of vacuum can often be used for fluters and wrappers). 
         [0028]    The balloon catheter gripping system described herein is a cost effective tool that can be particularly well suited for balloon catheter manufacturing. These improved devices can substantially speed-up, simplify, and improve the balloon folding and wrapping processes. The balloon catheter gripping system described herein may be used with a wide variety of balloon catheter sizes and shapes. The balloon catheter gripping system can be provided as separate units. Each gripper and/or tensioner can be controlled by a control unit (e.g., pneumatic, mechanical, electrical, and/or magnetic). 
         [0029]    The front gripper and the back gripper each can comprise a mechanism to grip the balloon catheter and/or a guide wire extended through the balloon catheter. The tensioner e.g., movement of the front gripper or pulling by the operator, can straighten the balloon catheter and/or the guide wire. The movement of the blades wraps the folds around a catheter shaft so as to provide a relatively small diameter. 
         [0030]    As shown in  FIG. 1 , a balloon catheter  10  can have a straight inner lumen  12 . In some embodiments, the straight inner lumen  12  is supported so as to be straight or substantially straight within the balloon catheter  10 . For balloon catheters designed for use with larger diameter guide wires, for example 0.018″ or larger diameter guide wires (e.g., 0.035″ diameter guide wires), the straight inner lumen  12  may be straightened during fluting. The larger diameter guide wire or stylet of similar size is typically used during fluting to straighten the balloon catheter  10 . The larger diameter guide wires can often provide sufficient stiffness so as to straighten out the straight inner lumen  12  of the balloon catheter  10 . 
         [0031]    The straight inner lumen  12  can be straight, substantially straight, partially straight, and/or other linear configurations. The straight inner lumen  12  extends through at least a portion of the balloon catheter  10 . In some embodiments, the straight inner lumen  12  can extend from a proximal end  14  of the balloon catheter  10  to a distal end  16  of the balloon catheter  10 . In other embodiments, the straight inner lumen  12  extends through a portion of the length of the balloon catheter  10 . 
         [0032]      FIG. 2  shows a cross-sectional view of the balloon catheter  10 . In some embodiments, the straight inner lumen  12  is supported so as to be coaxial within the balloon catheter  10 . In other words, the straight inner lumen  12  extends along the longitudinal axis A- A of the balloon catheter  10 , see  FIG. 1 . A guide wire  18  can extend through the straight inner lumen  12  in order to support the straight inner lumen  12  during fluting. The guide wire  18  can be coaxial with the balloon catheter  10  and/or the straight inner lumen  12 . The straight inner lumen  12  is centered within the balloon catheter  10 . The balloon catheter  10  having a straight inner lumen  12  can provide acceptable flutes or pleats. 
         [0033]      FIG. 3  shows a cross-sectional view of the balloon catheter  10 . The balloon catheter  10  has been folded to create flutes  20 .  FIG. 3  shows three flutes, but other embodiments are contemplated. The folding process can create even flutes  20 . These even flutes  20  will typically fold well. The straight inner lumen  12  may linear along the longitudinal axis A-A of the balloon catheter  10 , see  FIG. 1 . The flutes  20  may be regular along the length of the balloon catheter  10 . 
         [0034]    As shown in  FIG. 4 , a balloon catheter  22  can have a bowed inner lumen  24 . The bowed inner lumen  24  can be curved, substantially curved, partially curved, bowed, substantially bowed, partially bowed, serpentine, substantially serpentine, partially serpentine and/or other non-linear configurations. The bowed inner lumen  24  can be caused by the balloon catheter  22  being unsupported. 
         [0035]    For balloon catheters designed for use with smaller diameter guide wires, for example 0.014″ or smaller diameter guide wires (e.g., 0.010″ diameter guide wires), the stiffness of the guide wire can be insufficient to provide enough support during fluting. The smaller diameter guide wires do not provide sufficient stiffness so as to straighten out the inner lumen and the balloon catheter during fluting. With longer lengths of balloon catheters, the extent of bowing of the inner lumen of the balloon catheter increases significantly. The bowed inner lumen  24  is not centered within the balloon catheter  22 . The balloon catheter  22  having a bowed inner lumen  24  can potentially create uneven and lumpy flutes that may not fold well. 
         [0036]    The bowed inner lumen  24  extends through at least a portion of the balloon catheter  22 . In some embodiments, the bowed inner lumen  24  can extend from a proximal end  26  of the balloon catheter  22  to a distal end  28  of the balloon catheter  22 . In other embodiments, the bowed inner lumen  24  extends through a portion of the length of the balloon catheter  22 . 
         [0037]      FIG. 5  shows a cross-sectional view of the balloon catheter  22 . In some embodiments, the bowed inner lumen  24  is unsupported so as to be not coaxial within the balloon catheter  22 . In other words, the bowed inner lumen  24  is offset from the longitudinal axis B-B of the balloon catheter  22 . A guide wire  30  can extend through the bowed inner lumen  24 . The guide wire  30  can be coaxial with the bowed inner lumen  24 . The guide wire  30  can be insufficient to straighten the bowed inner lumen  24  during fluting. The guide wire  30  can be offset from the longitudinal axis B-B of the balloon catheter  22 , see  FIG. 4 . In some embodiments, the gripping system can increase the straight-line distance between two ends of the bowed inner lumen  24  moving from a first bowed configuration to a second linear configuration after gripping. In some embodiments, the straight-line distance between two ends of the bowed inner lumen  24  can increase by at least about 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 1 0 %, 12%, 15%, 20%, 25%, 30%, 40%, 50% or more from the linear relative to the bowed configuration, or various ranges between any of the aforementioned values, such as from about 2% to about 20% for example. 
         [0038]      FIG. 6  shows a cross-sectional view of the balloon catheter  22 . The balloon catheter  22  has been folded to create flutes  32 .  FIG. 6  shows three flutes  32 , but other embodiments, having one, two, four, five, six, or more flutes are contemplated. The balloon catheter  22  having a bowed inner lumen  24  can provide uneven and lumpy flutes that may not fold well. As shown, the folding process created uneven flutes  32 . These uneven flutes  32  may not fold well. The bowed inner lumen  24  may not be consistently offset from the longitudinal axis B-B of the balloon catheter  22 , see  FIG. 4 . The flutes  32  may be irregular along the length of the balloon catheter  22 . 
         [0039]      FIGS. 7A-7B  illustrates a three blade fluter system  34  having a plurality of blades  36 . A cavity  38  is defined by the convergence of the plurality of blades  36 . The cavity  38  is configured to receive a balloon catheter, such as the balloon catheter  10 ,  22 . The cavity  38  can have a longitudinal axis C-C, see  FIG. 11 . If the inner lumen  12 ,  24  of the balloon catheter  10 ,  22  is not centered within the cavity  38  as the plurality of blades  36  come together, then the flutes could be uneven and/or the catheter could be damaged. In other words, the inner lumen  12 ,  24  of the balloon catheter  10 ,  22  should align with the longitudinal axis C-C of the cavity. In some embodiments, the inner lumen  12 ,  24  of the balloon catheter  10 ,  24  should be coaxial with longitudinal axis C-C of the cavity. The methods and devices for balloon catheter folding are further described in commonly owned, U.S. Pat. No. 7,762,804, the disclosure of which are hereby incorporated by reference in their entirety and should be considered a part of this specification. 
         [0040]      FIG. 8  shows a front view of a back gripper  40 .  FIG. 9  shows a perspective view of a back gripper  40 . The back gripper  40  can be configured to grasp the proximal end  14 ,  26  of the balloon catheter  10 ,  22 . The back gripper  40  can be configured to grasp the balloon catheter  10 ,  22  along a length of the balloon catheter  10 ,  22 . In some embodiments, the back gripper  40  can be configured to grasp a portion of the balloon catheter  10 ,  22 . 
         [0041]    In some embodiments, the back gripper  40  centers and grabs the one or more supporting guide wires  18 ,  30 . The back gripper  40  can be configured to grasp one end of the guide wire  18 ,  30 . The back gripper  40  can be configured to grasp the proximal end  14 ,  26  of the balloon catheter  10 ,  22  and one end of the guide wire  18 ,  30 . The back gripper  40  can be configured to grasp the balloon catheter  10 ,  22  and/or the guide wire  18 ,  30  disposed therewithin. The back gripper  40  can be located on a first end of the fluter system  34 . 
         [0042]    The back gripper  40  can be controlled by a control unit (e.g., pneumatic, mechanical, electrical, and/or magnetic).  FIGS. 8-9  show a pneumatic back gripper. In some embodiments, the back gripper  40  is coupled to a foot pedal  42  or another control to actuate the back gripper  40 . In some embodiments, the foot pedal  42  can be coupled to a fluid source. The foot pedal  42  can be used to actuate the back gripper  40  between an open configuration wherein the balloon catheter  10 ,  22  and/or the guide wire  18 ,  30  is not grasped and a closed configuration wherein the balloon catheter  10 ,  22  and/or the guide wire  18 ,  30  is grasped. 
         [0043]    In order to align the back gripper  40 , the mounts can be made with a small amount of float. A pin (not shown) with a diameter generally the same as or similar to the balloon catheter  10 ,  22  can be placed in the fluter system  34 . The plurality of blades  36  can be closed around the pin. The back gripper  44  can be centered mechanically on the pin. Then, the mounts can be tightened. 
         [0044]      FIG. 10  shows a side view of a front gripper  44 . The front gripper  44  can be configured to grasp the distal end  16 ,  28  of the balloon catheter  10 ,  22 . The front gripper  44  can be configured to grasp the balloon catheter  10 ,  22  along a length of the balloon catheter  10 ,  22 . In some embodiments, the front gripper  44  can be configured to grasp a mid- portion of the balloon catheter  10 ,  22 . In some embodiments, the front gripper  44  can be configured to grasp a portion of the balloon catheter  10 ,  22 . In some embodiments, the front gripper  44  can be configured to grasp the shaft of the balloon catheter  10 ,  22 . The larger area of the front gripper  44  distributes the force of the front gripper  44 . 
         [0045]    In some embodiments, the front gripper  44  centers and grabs the one or more supporting guide wires  18 ,  30 . The front gripper  44  can be configured to grasp one end of the guide wire  18 ,  30 . The front gripper  44  can be configured to grasp the distal end  16 ,  28  of the balloon catheter  10 ,  22  and one end of the guide wire  18 ,  30 . The front gripper  44  can be configured to grasp the balloon catheter  10 ,  22  and/or the guide wire  18 ,  30  disposed therewithin. The front gripper  44  can be located near the second end of the fluter system  34   
         [0046]    The front gripper  44  can be coupled to a base  48 . The base  48  can be coupled to a fluter system, such as fluter system  34 . The front gripper  44  can be controlled by a control unit (pneumatic, mechanical, electrical, magnetic). In some embodiments, the base  48  includes ports  52  to accept fluid. The ports  52  can be used to actuate the front gripper  44  between an open configuration wherein the balloon catheter  10 ,  22  and/or the guide wire  18 ,  30  is not grasped and a closed configuration wherein the balloon catheter  10 ,  22  and/or the guide wire  18 ,  30  is grasped. 
         [0047]    In some embodiments, a front gripper  44  can be coupled to a sliding balloon guide  46 . The sliding balloon guide  46  can be configured to slide along a length of the balloon catheter  10 ,  22 . In some embodiments, the sliding balloon guide  46  can be configured to slide along a mid-portion of the balloon catheter  10 ,  22 . The sliding balloon guide  46  can be spaced from the front gripper  44 . In some embodiments, the sliding balloon guide  46  is disposed between the back gripper  40  and the front gripper  44 . In some embodiments, the sliding balloon guide  46  is configured to provide radial support for the balloon catheter  10 ,  22 . In some embodiments, the sliding balloon guide  46  is configured to facilitate the straightening of the balloon catheter  10 ,  22  and/or guidewire  18 ,  30 . 
         [0048]    The sliding balloon guide  46  can be located on a second end of the fluter system  34 . The sliding balloon guide  46  can be centered on the same axis as the back gripper  40 , the front gripper  44 , the longitudinal axis A-A, the longitudinal axis B-B, and/or the longitudinal axis C-C. In one embodiment, the sliding balloon guide  46  is a rail centered on the same axis as the front gripper  44  grasping the balloon catheter  10 ,  22 . 
         [0049]    With the shaft of the balloon catheter  10 ,  22  centered, the operator can provide tension. The operator can apply tension by any suitable means of applying tension known in the art. For instance, the operator can pull directly on the guide wire or pull the guide wire indirectly through pulling the shaft of the balloon catheter  10 ,  22 . 
         [0050]    In some embodiments, the gripper system includes a tensioner, e.g., a function added to the front gripper  44 , a sliding balloon guide  46 , the back gripper  40  or a separate component. With this approach the guide wire  18 ,  30  can be grabbed by the gripper system, directly or indirectly, and tension applied. For instance, a pneumatic spring can apply tension. For instance, the front gripper  44  can be configured to apply tension to the balloon catheter  10 ,  22 . For instance, the front gripper  44  can translate linearly along the base  48  to apply tension. The front gripper  44  can apply tension after the front gripper  44  grasps the balloon catheter  10 ,  22 . For instance, the sliding balloon guide  46  can be configured to apply tension to the balloon catheter  10 ,  22 . For instance, the sliding balloon guide  46  can translate linearly along the base  48  to apply tension. The sliding balloon guide  46  can apply tension after the front gripper  44  grasps the balloon catheter  10 ,  22 . 
         [0051]    Any of the grippers, such as the back gripper  40  and the front gripper  44 , can be pneumatic, mechanical and/or electrical. The tensioner, such as the tensioning provided by the front gripper  44 , can be pneumatic, mechanical and/or electrical. 
         [0052]    Once there is sufficient tension, the fluting process can be initiated. Due to the tension, the inner lumen of the balloon catheter  10 ,  22  can be centered within the flutes. Once the fluting is completed, the balloon catheter  10 ,  22  can be kept under vacuum to maintain the flutes and centering of the inner lumen and transferred to a wrapping station or manually wrapped (use of vacuum is typical for fluters and wrappers). 
         [0053]      FIG. 11  shows a side view of a gripping system  50 . The gripping system  50  can include the back gripper  40 . The back gripper  40  can be configured to grasp the balloon catheter  10 ,  22  and/or the guide wire  18 ,  30  disposed therewithin. In some embodiments, the back gripper  40  can be coupled to the fluter system, such as fluter system  34 . The fluter system  34  can include the plurality of blades  36 . The cavity  38  defined by the convergence of the plurality of blades  36 . The cavity  38  is configured to receive a balloon catheter, such as the balloon catheter  10 ,  24 . The cavity  38  can have a longitudinal axis C-C. 
         [0054]    The gripping system  50  can include the front gripper  44 . The front gripper  44  can be configured to grasp the balloon catheter  10 ,  22  and/or the guide wire  18 ,  30  disposed therewithin. The front gripper  44  can be coupled to a sliding balloon guide  46 . In some embodiments, the sliding balloon guide  46  can be coupled to the fluter system  34 . The front gripper  44  can be coupled to a base  48 . In some embodiments, the base  48  can be coupled to the fluter system  34 . 
         [0055]    In some methods, a balloon catheter  22  can have a bowed inner lumen  24  is placed within the cavity  38 , as shown in  FIG. 12 . The cavity  38  has longitudinal axis C-C. The bowed inner lumen  24  is offset from the longitudinal axis B-B of the balloon catheter  22 . The bowed inner lumen  24  does not align with the longitudinal axis C-C. In some embodiments, the longitudinal axis B-B of the balloon catheter  22  aligns with the longitudinal axis C-C. If the blades  36  were to close on the balloon catheter  22  in this configuration, then the flutes may be uneven, see  FIG. 6 . 
         [0056]    In some methods, the back gripper  40  grasps the balloon catheter  22  and/or the guide wire  30  disposed therewithin. The front gripper  44  grasps the balloon catheter  22  and/or the guide wire  30  disposed therewithin. In some embodiments, the sliding balloon guide  46  slides along the length of the balloon catheter  22 . In some embodiments, the sliding balloon guide  46  is disposed between the back gripper  40  and the front gripper  44 . 
         [0057]    The tensioner can be configured to apply tension to the balloon catheter  10 ,  22  and/or the guide wire  18 ,  30  disposed therewithin. In some embodiments, the tensioner is a function of the front gripper  44 . The front gripper  44  applies tension to the balloon catheter  10 ,  22  and/or the guide wire  18  disposed therewithin. The tension causes the guide wire  18 ,  30  to straighten. In some embodiments, the tension causes the guide wire  18 ,  30  to assume a substantially linear path between the back griper  40  and the front gripper  44 . In some embodiments, the tension causes the guide wire  18 ,  30  to become coaxial with the longitudinal axis C-C of the cavity  38 . In some embodiments, the tensioner is a function added to the front gripper  44 , a sliding balloon guide  46 , and/or the back gripper  40 . In some embodiments, the tensioner is a separate component. 
         [0058]    In some embodiments, the guide wire  30  adjusts the position of the bowed inner lumen  24 . The bowed inner lumen  24  can become substantially linear due to the tension applied to the guide wire  30 . In some embodiments, the tension by the guide wire  30  causes the bowed inner lumen  24  to become coaxial with the longitudinal axis C-C of the cavity  38 . The bowed inner lumen  24  can be aligned with the longitudinal axis C-C of the cavity  38  upon applying tension. If the blades  36  were to close on the balloon catheter  22  in this configuration, then the flutes may be even. Once the balloon catheter  22  is fluted, the back griper  40  and the front gripper  44  release the balloon catheter  22 . The balloon catheter  22  can be withdrawn from the fluter  34  and the sliding balloon guide  46 . 
         [0059]    It is contemplated that various combinations or subcombinations of the specific features and aspects of the embodiments disclosed above may be made and still fall within one or more of the inventions. Further, the disclosure herein of any particular feature, aspect, method, property, characteristic, quality, attribute, element, or the like in connection with an embodiment can be used in all other embodiments set forth herein. Accordingly, it should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the disclosed inventions. Thus, it is intended that the scope of the present inventions herein disclosed should not be limited by the particular disclosed embodiments described above. Moreover, while the invention is susceptible to various modifications, and alternative forms, specific examples thereof have been shown in the drawings and are herein described in detail. It should be understood, however, that the invention is not to be limited to the particular forms or methods disclosed, but to the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the various embodiments described and the appended claims. Any methods disclosed herein need not be performed in the order recited. The methods disclosed herein include certain actions taken by a practitioner; however, they can also include any third-party instruction of those actions, either expressly or by implication. For example, actions such as “expanding a balloon” include “instructing the expanding of a balloon.” The ranges disclosed herein also encompass any and all overlap, sub-ranges, and combinations thereof. Language such as “up to,” “at least,” “greater than,” “less than,” “between,” and the like includes the number recited. Numbers preceded by a term such as “approximately”, “about”, and “substantially” as used herein include the recited numbers (e.g., about 10%=10%), and also represent an amount close to the stated amount that still performs a desired function or achieves a desired result. For example, the terms “approximately”, “about”, and “substantially” may refer to an amount that is within less than 10% of, within less than 5% of, within less than 1% of, within less than 0.1% of, and within less than 0.01% of the stated amount.