guide wire

Abstract

This document discloses a guidewire comprising a distal segment, a proximal segment, and an intermediate segment disposed between the distal and proximal segments, wherein the bending stiffness of the intermediate segment is greater than that of both the distal and proximal segments. The distal segment is configured for insertion into a patient's vascular system. The diameter of the intermediate segment may be larger than that of the distal segment. The guidewire may include a tapered distal transition portion disposed between the distal and intermediate segments, and a solid wire extending the length of the guidewire, the solid wire including a first diameter extending along the distal segment, a second diameter extending along the proximal segment, and a third diameter extending along the intermediate segment, wherein the third diameter is larger than the first and second diameters.

Description

[0001] priority

[0002] This application claims priority to U.S. Provisional Application No. 63 / 120,913, filed December 3, 2020, which is incorporated herein by reference in its entirety. Technical Field

[0003] This application relates to the field of medical devices, and more specifically to guidewires. Background Technology

[0004] Inserting an intravascular catheter through the skin and into a patient's vascular system typically involves using a needle positioned within the lumen of the catheter. The needle provides a sharp tip and increases the stiffness of the catheter to aid in the insertion process. The catheter may be packaged with the needle already inserted, or the clinician may insert the needle into the catheter during use. In some cases, the clinician may reinsert the needle into the catheter after initial placement. Rapid placement of larger catheters, such as central venous catheters (CVCs), may involve inserting a guide catheter through the lumen of the CVC. In this case, the guide catheter may include a needle. The foregoing are merely some examples of the many situations in which a clinician may insert a needle through the lumen of a catheter. The tubular portion of a catheter is flexible and can be several inches long. These characteristics create difficulty when inserting a sharp needle through the lumen of the catheter. Insertion of the needle through the lumen of the catheter may also potentially puncture the tubular wall of the catheter, rendering it unusable. As mentioned above, there is a need to reduce the tendency for the needle tip to puncture the catheter wall when inserting the needle through the lumen of the catheter. This article discloses a needle-tip blunting guidewire and a method thereof to address the above problems. Summary of the Invention

[0005] This document discloses implementation schemes for a guidewire, including a flexible distal segment, a flexible proximal segment, and an intermediate segment positioned between the distal and proximal segments. In some implementations, the distal segment is configured for insertion into a patient's vascular system. In some implementations, the intermediate segment is less flexible than the distal and proximal segments. The intermediate segment may be rigid, and its diameter may be larger than that of the distal segment. In some implementations, a gradually tapering distal transition portion is positioned between the distal and intermediate segments.

[0006] In some embodiments, the guidewire includes a solid wire extending the length of the guidewire. The solid wire includes a first diameter extending along a distal segment, a second diameter extending along a proximal segment, and a third diameter extending along an intermediate segment. The third diameter may be larger than the first and second diameters, and the third diameter defines the outer diameter of the guidewire along the intermediate segment.

[0007] In some embodiments, the guidewire includes a solid wire extending the length of the guidewire and a coil arranged around the solid wire along the length of the guidewire. The guidewire may also include a material applied around the guidewire along an intermediate section. This material may be liquid during application and may transform into a solid after application.

[0008] In some implementations, the guidewire includes a solid wire extending the length of the guidewire and a sheath threaded through the solid wire. The sheath is positioned along an intermediate section and defines the outer diameter of the guidewire along the intermediate section.

[0009] In some embodiments, the guidewire includes a flexible distal segment, a flexible proximal segment, a rigid intermediate segment disposed between the distal and proximal segments, and a cannula passing over the guidewire. The distal tip of the cannula is positioned such that the proximal portion of the intermediate segment is disposed within the cannula and the distal portion of the intermediate segment extends distally beyond the distal tip of the cannula. The outer diameter of the intermediate segment and the inner diameter of the cannula can: 1) define a longitudinal sliding fit between the intermediate segment and the cannula, and 2) restrict the intermediate segment to be parallel to the cannula.

[0010] In some embodiments, the method of using a guidewire includes: obtaining a guidewire comprising a flexible distal segment, a flexible proximal segment, and a rigid intermediate segment disposed between the distal and proximal segments; passing a cannula over the guidewire; positioning the tip of the cannula between the distal and proximal ends of the intermediate segment; and inserting the cannula and guidewire distally through a tubular member while maintaining the position of the cannula relative to the guidewire. The method may further include: contacting the tubular member with the intermediate segment to restrain the tubular member away from the sharp point of the cannula.

[0011] In some embodiments, after positioning the tip of the cannula between the distal and proximal ends of the intermediate segment, at least a portion of the proximal segment can be disposed within the cannula. In some embodiments, the tubular member is a first intravascular catheter that can be at least partially inserted into the patient's vascular system. In some embodiments, the method includes inserting a guidewire and a cannula into a second intravascular catheter. In other embodiments, the method includes inserting a guidewire, a cannula, and the first intravascular catheter into the second intravascular catheter. In some embodiments, the method further includes inserting a distal segment of the guidewire into the vascular system, and in some embodiments, the distal segment is inserted into the vascular system before the cannula is passed over the guidewire.

[0012] These and other features of the concept provided herein will become more apparent to those skilled in the art in light of the accompanying drawings and the following description, which describe specific embodiments of the concept in more detail. Attached Figure Description

[0013] Figure 1 A needle-tip passivated guidewire is shown according to some implementation schemes.

[0014] Figure 2 It is based on some implementation plans. Figure 1 A cross-sectional side view of a portion of a needle tip passivated guidewire, illustrating a first method of constructing a needle tip passivated guidewire.

[0015] Figure 3 It is based on some implementation plans. Figure 1 A cross-sectional side view of a portion of a needle tip passivated guidewire, illustrating a second method of constructing the needle tip passivated guidewire.

[0016] Figure 4 It is based on some implementation plans. Figure 1 A cross-sectional side view of a portion of a needle tip passivated guidewire, illustrating a third method of constructing a needle tip passivated guidewire.

[0017] Figure 5 It is based on some implementation plans. Figure 1 A cross-sectional side view of a portion of a needle-tip-blunted guidewire combined with a portion of a cannula.

[0018] Figure 6 It is based on some implementation plans. Figure 5 A cross-sectional side view of the combination of the tubular component and a portion thereof. Detailed Implementation

[0019] Before disclosing some specific embodiments in more detail, it should be understood that the specific embodiments disclosed herein do not limit the scope of the concepts provided herein. It should also be understood that the specific embodiments disclosed herein may have features that allow them to be readily separable from the specific embodiments and optionally combined with or substituted for features of any of the many other embodiments disclosed herein.

[0020] Regarding the terminology used herein, it should also be understood that these terms are for the purpose of describing certain specific embodiments and do not limit the scope of the concepts provided herein. Ordinal numbers (e.g., first, second, third, etc.) are generally used to distinguish or identify different features or steps in a set of features or steps and do not provide for sequential or numerical limitations. For example, the features or steps “first,” “second,” and “third” do not need to appear in that order, and a particular embodiment including such features or steps does not need to be limited to three features or steps. For convenience, labels such as “left,” “right,” “top,” “bottom,” “front,” “back,” etc., are used, and these labels are not intended to imply, for example, any particular fixed position, orientation, or direction. Rather, such labels are used to reflect, for example, relative position, orientation, or direction. The singular forms “a,” “an,” and “the” include plural references unless the context clearly indicates otherwise.

[0021] The terms "proximal," "proximal portion," or "proximal portion" of a catheter, as disclosed herein, include a portion of the catheter intended to be close to the clinician when used with a patient. Similarly, the term "proximal length" of a catheter includes the length of the catheter intended to be close to the clinician when used with a patient. For example, the term "proximal end" of a catheter includes the tip of the catheter intended to be close to the clinician when used with a patient. A proximal portion, proximal portion, or proximal length of a catheter may include the proximal end of the catheter; however, a proximal portion, proximal portion, or proximal length of a catheter does not necessarily include the proximal end of the catheter. That is, unless the context otherwise suggests, a proximal portion, proximal portion, or proximal length of a catheter is not the distal portion or distal length of the catheter.

[0022] The terms "distal," "distal portion," or "distal part" of a catheter, as disclosed herein, include a portion of the catheter intended to be close to or within the patient when used in the patient's body. Similarly, the term "distal length" of a catheter, for example, includes the length of the catheter intended to be close to or within the patient when used in the patient's body. The term "distal end" of a catheter, for example, includes the tip of the catheter intended to be close to or within the patient's body when used in the patient's body. A distal portion, distal part, or distal length of a catheter may include the distal end of the catheter; however, a distal portion, distal part, or distal length of a catheter does not necessarily need to include the distal end of the catheter. That is, unless the context otherwise suggests, a distal portion, distal part, or distal length of a catheter is not the distal portion or distal length of the catheter.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art.

[0024] Any method disclosed herein includes one or more steps or actions for performing the described method. The steps and / or actions of this method may be interchangeable. In other words, the order and / or use of a particular step and / or action may be modified unless the correct operation of the implementation requires a specific order of steps or actions. Furthermore, only a portion of the subroutines or methods described herein may be separate methods within the scope of this disclosure. In other words, some methods may include only a portion of the steps described in a more detailed method.

[0025] Figure 1 A needle tip passivated guidewire (NTBG) 100 according to some embodiments described herein is shown. The NTBG 100 can be used in conjunction with a needle cannula to passivate the sharp tip of the cannula, as described in detail below. The NTBG 100 can be configured for insertion through the cannula. The NTBG 100 includes a distal segment 101, an intermediate segment 102, a proximal segment 103, a distal end 104, and a proximal end 105. As further described, each of segments 101, 102, and 103 may include different dimensions and characteristics. The intermediate segment 102 includes a distal end 116 and a proximal end 117.

[0026] The distal segment 101 can be configured to be positioned within a patient's vascular system. Thus, the distal segment 101 can include sufficient flexibility to pass through the vascular system without causing damage to the vascular wall. In other words, the distal segment 101 can bend during insertion to conform to the structure of the vascular system without kinking or plastic deformation. In some embodiments, the distal segment 101 can include flexibility consistent with a medical guidewire configured to pass through the vascular system, as discussed further below. The distal segment 101 can also include sufficient stiffness to allow insertion via distally applied compressive forces without buckling within the vascular system. In some embodiments, the distal segment 101 can include a length sufficient to extend from the vascular system insertion site to a desired location within the vascular system, such as near or within the heart. Thus, placement of the endovascular device can include using an NTBG 100 as an endovascular guidewire. In other embodiments, the distal segment 101 can be short, such that the distal segment extends less than approximately 1 cm to 5 cm away from, for example, the end of a cannula.

[0027] The distal segment 101 may include a circular cross-section having a diameter 111 consistent with insertion through the vascular system, cannula, and / or catheter lumen. In some embodiments, the distal segment 101 may include one or more pre-formed bends or shapes to facilitate insertion through the vascular system. The pre-formed shape may be two-dimensional, for example... Figure 1 The "J" shape shown may be three-dimensional.

[0028] The proximal segment 103 can be configured for manual insertion into the cannula of a needle. The proximal segment 103 may include sufficient rigidity for manual grasping by a clinician and for distal pushing into the cannula without kinking or plastic deformation. The proximal segment 103 may include flexibility consistent with being coiled for placement in a packaging container without kinking or plastic deformation. In some embodiments, the proximal segment 103 may be less flexible than the distal segment 101. The proximal segment 103 may include a circular cross-section having a diameter 113 consistent with its placement within the cannula. In some embodiments, the diameter 113 may be larger than the diameter 111. In some embodiments, the proximal segment 103 may be configured to be positioned within the patient's vascular system; therefore, the proximal segment 103 may include similar physical characteristics to the distal segment 101.

[0029] In some implementations, the proximal segment 103 may include a marker 110. Marker 110 may indicate the distance to the intermediate segment 102. In some cases, the distal tip of the cannula may not be visible to the clinician. The position of marker 110 relative to the proximal end of the cannula may indicate the position of the intermediate segment 102 relative to the distal tip of the cannula. Marker 110 may also indicate the distance to the distal end 104 of the NTBG 100. In some cases, the clinician may observe marker 110 to determine the location of the distal end 104 along the patient's vascular system.

[0030] Intermediate section 102 is disposed between distal section 101 and proximal section 103. In the illustrated embodiment, intermediate section 102 may be straight to correspond to a straight cannula. In some embodiments, intermediate section 102 may include a bend corresponding to a curved cannula. Intermediate section 102 may remain straight during use. As is known, catheters, guidewires, and other elongated medical devices have different levels or degrees of stiffness (or flexibility), which are commonly referred to as bending stiffness or flexural rigidity. Bending stiffness is understood as the product of the elastic modulus (E) and the moment of inertia (I) of a material, where bending stiffness (EI) has SI units of Newtons (N)·meter. 2 (m 2 ) or N·m 2 .

[0031] In certain situations, specific medical procedures may require medical devices to have a specific stiffness. As further known, the stiffness of a medical device can be determined by the materials it comprises, the shape and size of the medical device, and any weaves used in its construction. The intermediate segment 102 may include a circular cross-section having a diameter 112, which in some embodiments may be larger than the diameter 111 of the distal segment 101 and the proximal segment 103. The intermediate segment 102 may include tight diameter tolerances. In some embodiments, the diameter tolerance of diameter 112 may be approximately ±0.002 inches, ±0.001 inches, ±0.0005 inches, ±0.0002 inches, or tighter.

[0032] Intermediate segment 102 may include a distal transition portion 106. The distal transition portion 106 may define a smooth transition of physical properties between distal segment 101 and intermediate segment 102. The distal transition portion 106 may include a tapering portion to transition the diameter 111 of distal segment 101 to the diameter 112 of intermediate segment 102. The distal transition portion 106 may also be configured to transition the flexibility of distal segment 101 to the stiffness of intermediate segment 102. In some embodiments, the distal transition portion 106 may define a strain relief portion. Similarly, intermediate segment 102 may include a proximal transition portion 107. The proximal transition portion 107 may define a smooth transition of physical properties between proximal segment 103 and intermediate segment 102. In some embodiments, intermediate segment 102 may be configured to be disposed within a patient's vascular system. More specifically, the length of intermediate segment 102 may be short enough to pass through a tortuous portion of the intended vascular system.

[0033] Figures 2 to 4 Different methods for constructing NTBG 100 are shown. For example... Figure 2 As shown, according to the first construction method, the NTBG 100 can be constructed from a solid wire 200. The wire 200 can extend along the entire length of the NTBG 100. In some embodiments, the wire 200 can be formed of a nitinol material. Figure 2In one embodiment, wire 200 includes a distal wire portion 201, an intermediate wire portion 202, and a proximal wire portion 203 corresponding to a distal segment 101, an intermediate segment 102, and a proximal segment 103, respectively. The diameter of wire 200 may be sufficiently thin along the distal wire portion 201 and the proximal wire portion 203 to facilitate flexibility in the distal segment 101 and the proximal segment 103, respectively. The distal wire portion 201 and the proximal wire portion 203 may also be wound with a distal coil 210 and a proximal coil 211, respectively. The wire 200 may be sufficiently thick along the diameter of the intermediate wire portion 202 to facilitate stiffness in the intermediate segment 102. The intermediate wire portion 202 may define a diameter 112 for the intermediate segment 102. The intermediate wire portion 202 may also be formed via a process consistent with the diameter tolerance defining the intermediate segment 102, such as grinding. In some embodiments, wire 200 may include a distal taper 206 to transition the diameter of the intermediate segment 202 to the diameter of the distal wire portion 201, the distal taper potentially defining at least partially the transition portion 106. Similarly, wire 200 may include a proximal taper 207 to transition the diameter of the intermediate segment 202 to the diameter of the proximal wire portion 201, the proximal taper potentially defining at least partially the transition portion 107.

[0034] Figure 3A second construction method for NTBG 100 is illustrated. This second construction method for NTBG 100 includes a solid wire 300 extending the length of NTBG 100. Wire 300 may be formed of nitinol. In some embodiments, the diameter of the wire may be constant along the length of wire 300, and coils 310 may be wound around wire 300 along its length. A middle section 102 of NTBG 100 is formed by applying a material 320 around wire 300 and coils 310 along the middle portion of wire 300. The applied material 320 may be a potting or molding material, such as epoxy resin. In some embodiments, material 320 may be a thermoplastic material inserted and molded onto wire 300 and coils 310. Material 320 may fill gaps between coils 310, which may alter the flexibility of wire 300 and coils 310. Material 320 can be added to the diameter of coil 310 to define the diameter 112 of intermediate segment 102. Material 320 can be liquid when applied and can be transformed into a solid after application. Once hardened, material 320 can define the desired stiffness of intermediate segment 102. After hardening, material 320 can be formed via a process consistent with the diameter tolerance defining the diameter 112 of intermediate segment 102, such as grinding. Material 320 may include a distal taper 326 to transition the diameter of intermediate segment 102 to the diameter of distal segment 101, the distal taper may at least partially define a transition portion 106. Similarly, material 320 may include a proximal taper 327 to transition the diameter of intermediate segment 102 to the diameter of proximal segment 103, the proximal taper may at least partially define a transition portion 107.

[0035] Figure 4A third construction method for the NTBG 100 is illustrated. This third construction method for the NTBG 100 includes a solid wire 400 extending the length of the NTBG 100. The wire 400 may be formed of nitinol. In some embodiments, the diameter of the wire may be constant along the length of the wire 400. A sleeve 420 may be threaded through and attached to the wire 400. The wire 400 may have a distal coil 410 and a proximal coil 411 wound along a distal section 101 and a proximal section 103, respectively. An intermediate section 102 of the NTBG 100 is defined by the sleeve 420. The sleeve portion 420 may be formed of metal or rigid plastic to define the desired stiffness of the intermediate section 102. The sleeve 420 may also be formed by a process consistent with the diameter tolerance of the diameter 112 defining the intermediate section 102, such as grinding. The sleeve 420 may include a distal taper 426 to transition the diameter of the intermediate segment 102 to the diameter of the distal segment 101, the distal taper at least partially defining a transition portion 106. Similarly, the sleeve 420 may include a proximal taper 427 to transition the diameter of the intermediate segment 102 to the diameter of the proximal segment 103, the proximal taper at least partially defining a transition portion 107.

[0036] Figure 5 The NTBG 100 is shown for use with sleeve 500. Figure 5 A portion of a sleeve 500 passing through an NTBG 100 is shown. In some embodiments, the NTBG 100 may be provided with a sleeve 500. The sleeve 500 includes an inner diameter 511 and an outer diameter 512. The sleeve 500 passes through a proximal section 103 such that the end 510 of the sleeve 500 is arranged along an intermediate section 102. The inner diameter 511 of the sleeve 500 is dimensioned to correspond to the diameter 112 of the intermediate section 102. More specifically, the inner diameter 511 and the diameter 112 are dimensioned to minimize the radial clearance 513 between the sleeve 500 and the intermediate section 102, while allowing longitudinal sliding movement of the sleeve 500 relative to the intermediate section 102. In some embodiments, the diameter clearance may be less than approximately 0.003 inches, 0.002 inches, 0.001 inches, 0.0005 inches, or smaller.

[0037] like Figure 5As shown, the intermediate section 102 is positioned relative to the sleeve 500 such that the proximal portion 521 of the intermediate section 102 is disposed within the sleeve 500, and the distal portion 522 extends distally away from the end 510 of the sleeve 500. The proximal portion 521 may include sufficient length to engage with the gap 513, and the distal portion 522 is constrained to be parallel to the sleeve 500. The lengths of the intermediate section 102, the proximal portion 521, and the distal portion 522 may be defined relative to the diameter 112 of the intermediate section 102. In some embodiments, the length of the proximal portion 521 may be approximately 1, 2, 3, 4, or more times the diameter 112 of the intermediate section 102. In some embodiments, the length of the distal portion 521 may be approximately 0.25, 0.5, 1, 2, or more times the diameter 112. In some implementations, the length of the intermediate segment 102 may be approximately 1.25 times, 1.5 times, 2 times, 3 times, 4 times or more the diameter 112.

[0038] The end 510 of the cannula 500 may be a sharp end, such as an end that pierces the skin and / or the wall of a blood vessel. In other embodiments, the end 510 may be configured to be inserted through a septum. In some embodiments, the end 510 may include a point 517 disposed on the outer surface 518 of the cannula 500. In other embodiments, the end 510 may include a cut surface 516 that cuts the point 517 inwardly displaces it away from the outer surface 518 of the cannula 500.

[0039] The NTBG 100 can be provided in a variety of configurations. For example, in some embodiments, the distal segment 101 may include a length consistent with the placement of the intravascular device. Similarly, the NTBG 100 can be sized to be used with a specific cannula specification. For example, embodiments of the NTBG 100 can be configured for use with a variety of cannulas of a specified specification. As will be understood by one of ordinary skill in the art, the NTBG 100 can be configured with any combination of physical characteristics, such as length, diameter, and flexibility, for each of the distal, intermediate, and proximal segments (101, 102, 103).

[0040] Figure 6 Further examples of its use with the tubular member 600 are shown. Figure 5 The combination of NTBG 100 and cannula 500. In some embodiments, the tubular member 600 may be an intravascular catheter. For example... Figure 6 As shown, the longitudinal position of the intermediate section 102 relative to the sleeve 500 is... Figure 5 The same as shown. Also, see the reference above. Figure 5 As described, the distal portion 522 extends distally away from the end 510 and is constrained to be parallel to the sleeve 500. Figure 6The insertion into the tubular member 600 is shown. Figure 5 The combination of NTBG100 and sleeve 500 is inserted into tubular member 600 such that sleeve end 510 and distal portion 522 of intermediate section 102 are arranged within tubular member 600. Tubular member 600 is shown in a bent state, wherein tubular member 600 bends away from longitudinal axis 606 of intermediate section 102.

[0041] Figure 6 One scenario is illustrated where the bend in the tubular member 600 is sharp enough that the tubular wall 611 of the tubular member 600 contacts the distal portion 522 at the contact point 622. Since the distal portion 522 is a rigid extension of the sleeve 500, the contact between the tubular wall 611 and the distal portion 522 limits the sharpness of the bend in the segment of the tubular member 600 extending between the contact point 622 and the sleeve 500. Limiting the sharpness of the bend ensures a separation distance 630 between the point 517 of the sleeve end 510 and the tubular wall 611. The separation distance 630 further ensures that the point 517 does not contact or pierce the tubular wall 611. In summary, the distal portion 522 of the intermediate section 102 prevents the end 510 of the sleeve 500 from piercing the tubular member 600. In other words, the sharp end 510 of the cannula 500 is transformed into a blunt end by the distal portion 522 of the intermediate section 102, thereby protecting the tubular member 600 from puncture at point 517. Therefore, by first inserting the NTBG 100 into the cannula 500, the clinician can insert the cannula 500 into the tubular member 600 without worrying about puncturing the tubular member 600.

[0042] In some cases, the tubular member 600 may include both flexible and rigid properties to cause the curvature of the tubular member 600 to extend proximally beyond the distal end 510 of the conduit when the tubular wall 611 contacts the distal portion 522 at contact point 622. In this case, the curvature of the tubular member 600 can displace the tubular wall 611 radially away from the outer surface 518 of the sleeve 500, which can at least partially define the separation distance 630. In this case, with the distal end 517 disposed on the outer surface 518 of the sleeve 500, puncture of the tubular member 600 can be prevented.

[0043] The use of an NTBG may include the following steps or procedures. One method may include the step of inserting the NTBG through a cannula. The NTBG may be inserted distally, i.e., first at the distal end, or proximally, i.e., first at the proximal end. Passing the cannula over the NTBG can be similar to inserting the NTBG through the cannula. In some embodiments, the NTBG may be partially inserted, such that the distal or proximal end of the NTBG is positioned within the cannula.

[0044] One method may include the step of positioning the intermediate section of the NTBG near the end of the cannula, such that the end is positioned between the distal and proximal ends of the intermediate section, and such that the distal portion can effectively passivate the sharp end of the cannula.

[0045] One approach may include visually observing markings placed on the proximal segment of the NTBG, associated with the proximal end of the cannula, to determine the position of the intermediate segment relative to the cannula tip. In some cases, the cannula tip may be invisible to the clinician, and therefore, the position of the intermediate segment relative to the cannula tip may also be unseen. The position of the markings relative to the proximal end of the cannula can provide the clinician with a visual indication of the location of the intermediate segment adjacent to the cannula tip.

[0046] One method may include the step of contacting a tubular member (conduit) with an intermediate section (i.e., the distal portion of the intermediate section) to restrain the tubular member away from the tip of the cannula. More specifically, the distal portion contacts the inner surface of the tubular wall of the tubular member such that the tip of the cannula does not chisel or puncture the tubular wall.

[0047] One approach may include the step of inserting an NTBG through a catheter. The NTBG may be inserted distally, i.e., first into the distal segment, or proximally, i.e., first into the proximal segment. Passing the catheter over the NTBG can be similar to inserting the NTBG through the catheter. In some embodiments, the NTBG may be partially inserted, such that the distal end of the NTBG is positioned within the catheter. The NTBG may be inserted through the catheter before or after the catheter has been inserted into the patient.

[0048] A method may include inserting a cannula and an NTBG through a catheter in a single step. This step may be performed after the NTBG has been inserted through the cannula and after the intermediate segment has been positioned adjacent to the cannula tip. During this step, the position of the NTBG relative to the cannula may be constrained such that the intermediate segment remains positioned adjacent to the cannula tip.

[0049] A method may include inserting an NTBG and a cannula through a catheter in a single step. This step may be performed after the NTBG has been inserted through the cannula and after the intermediate segment has been positioned adjacent to the cannula tip. During this step, the position of the NTBG relative to the cannula may be constrained such that the intermediate segment remains positioned adjacent to the cannula tip.

[0050] A method may include inserting an NTBG, a cannula, and a catheter through a second catheter in a single step. This step may be performed after the NTBG has been inserted through the cannula, after the intermediate segment has been positioned adjacent to the cannula tip, and after the NTBG and cannula have been inserted through the first catheter. During this step, the position of the NTBG relative to the cannula may be constrained such that the intermediate segment remains positioned adjacent to the cannula tip.

[0051] A method may include the step of inserting an NTBG into a patient's vascular system. In some embodiments, only the distal segment of the NTBG is inserted into the patient. In other embodiments, at least a portion of the distal and intermediate segments is inserted into the patient. In still other embodiments, at least a portion of the distal, intermediate, and proximal segments is inserted into the patient.

[0052] One method may include the step of removing a cannula from the catheter. In this step, the cannula is displaced proximally relative to the catheter until no part of the cannula is inserted into the catheter. In some embodiments, the NTBG may maintain insertion through the cannula.

[0053] One approach may include the step of removing the cannula from the NTBG. Removing the cannula from the NTBG involves displacing the cannula proximally away from the proximal end of the NTBG. In some embodiments, the catheter may be retained and traveled over the NTBG.

[0054] One approach may include the step of passing a catheter over an NTBG without a cannula. In other words, the NTBG can be inserted into the patient, and the catheter can be passed over the NTBG proximally. The NTBG can be used as a guidewire when the catheter is inserted through the patient's vascular system.

[0055] One approach may include the step of visually observing markers placed on the proximal segment of the NTBG in relation to the vascular insertion site. The position of the markers relative to the vascular insertion site can provide clinicians with visual indications of the location of the distal end of the NTBG along the patient's vascular system.

[0056] While certain specific embodiments have been disclosed herein, and while these specific embodiments have been disclosed in considerable detail, they are not intended to limit the scope of the concepts provided herein. Other adaptations and / or modifications will arise to those skilled in the art, and these adaptations and / or modifications are also covered in a broader sense. Therefore, changes may be made to the specific embodiments disclosed herein without departing from the scope of the concepts provided herein.

Claims

1. A guidewire, characterized in that, include: Distal section; Proximal section; and The intermediate section is arranged between the distal section and the proximal section. The bending stiffness of the intermediate section is greater than that of both the distal and proximal sections, and the solid wire extends from the proximal end of the proximal section to the distal end of the distal section. The intermediate section is positioned within the cannula, with its proximal portion arranged within the cannula and its distal portion extending distally beyond the distal end of the cannula. The outer diameter of the intermediate section and the inner diameter of the cannula define a longitudinal sliding fit between the intermediate section and the cannula and constrain the intermediate section to be parallel to the cannula. The tubular member is bent away from the longitudinal axis of the intermediate section, causing the tubular wall of the tubular member to contact the distal portion. This contact ensures a separation distance between the distal end of the cannula and the tubular wall, which in turn prevents the distal end of the cannula from piercing the tubular member while passing over the guidewire. The cannula and the guidewire are configured to be inserted into the tubular member.

2. The guidewire according to claim 1, characterized in that, The distal segment is configured for insertion into the patient's vascular system.

3. The guidewire according to claim 1, characterized in that, The diameter of the middle section is larger than the diameter of the distal section.

4. The guidewire according to claim 1, characterized in that, It also includes a tapered distal transition portion disposed between the distal section and the intermediate section.

5. The guidewire according to claim 1, characterized in that, The solid wire includes: A first diameter extends along the distal segment of the guidewire; A second diameter, which extends along the proximal segment of the guidewire; and A third diameter extends along the middle section of the guidewire. The third diameter is larger than the first diameter and the second diameter.

6. The guidewire according to claim 5, characterized in that, The third diameter defines the outer diameter of the guidewire along the intermediate section.

7. A guidewire assembly, characterized in that, include: Guidewire, the guidewire comprising: Distal section; Proximal segment; and An intermediate section, which is arranged between the distal section and the proximal section, wherein: The bending stiffness of the intermediate section is greater than the bending stiffness of both the distal and proximal sections. The diameter of the proximal segment is larger than the diameter of the distal segment; and A cannula, which passes over the guidewire, wherein by arranging a proximal portion of the intermediate section within the cannula and extending a distal portion of the intermediate section distally beyond the distal end of the cannula, the outer diameter of the intermediate section and the inner diameter of the cannula define a longitudinal sliding fit between the intermediate section and the cannula and constrain the intermediate section to be parallel to the cannula, a tubular member is bent away from the longitudinal axis of the intermediate section, causing the tubular wall of the tubular member to contact the distal portion, the contact between the tubular wall and the distal portion ensuring a separation distance between the distal end of the cannula and the tubular wall, the separation distance thereby preventing the distal end of the cannula from piercing the tubular member, and the guidewire assembly is configured to be inserted into the tubular member.

Images