Dilator positioning assembly

Abstract

Vascular dilator positioning assemblies and systems, along with methods of use and assembly thereof, are described herein. Such assemblies and systems include a grip portion having a wall and an actuator for positioning the dilator tip relative to the sheath.

Description

Invention Name

[0001] Expander positioning assembly Technical Field

[0002] The technical field generally relates to vascular dilators, introducer sheaths, and components thereof for insertion into the body to provide intravascular access to various medical devices. This includes, but is not limited to, all arterial and vasculature access, abdominal and thoracic, cerebrospinal, genitourinary and gynecological, upper gastrointestinal, and colorectal procedures.

[0003] Embodiments generally provide systems and methods for positioning a dilator tip relative to an introducer sheath to reduce a gap between the dilator tip and the introducer sheath. Background Art

[0004] Vascular access devices, including vascular introducer sheaths and vascular dilators, are now very common in many endovascular procedures, such as transcatheter aortic valve replacement (TAVR), angioplasty, and stenting. Vascular access devices often facilitate access to the vascular system for the introduction of removable devices such as wires, balloons, pressure transducers, and for the introduction and placement of implantable devices such as mechanical aortic valves and stents.

[0005] Vascular access devices are now typically inserted percutaneously through the skin into a patient's blood vessel. Avoiding the need to cut the skin with a scalpel to expose the blood vessel for insertion makes the use of vascular access devices safer and more frequent. Percutaneous insertion techniques involve inserting a needle or similar puncture device into the skin without first cutting the skin to expose the blood vessel. The vascular access device is advanced through the skin and enters the blood vessel through the puncture. For the patient, percutaneous techniques reduce blood loss and reduce the possibility of human error that may occur when making the scalpel incision.

[0006] During percutaneous procedures, an introducer sheath is typically positioned at the entry point of a patient's blood vessel and pushed through the vessel until the sheath is securely seated where it is needed in the patient's body. The proximal end of the introducer sheath protrudes outside the patient's body to provide an entry point for subsequent insertion of additional or other intravascular devices. Often, a dilator is placed within the introducer sheath and pushed through the vessel opening with the introducer sheath to gradually open the vessel puncture site and allow entry of the sheath while minimizing vessel trauma.

[0007] The percutaneous access point is typically much smaller than the diameter of the introducer sheath, and a certain amount of force is required to stretch the patient's skin at the percutaneous opening to deliver the vascular access device into the vessel. Therefore, any device with grooves, notches, or angled edges may create entrapment points where the skin may get caught and tear, causing site trauma and delayed recovery for the patient.

[0008] Therefore, a typical introducer sheath has a tapered distal end to provide a smooth transition to the dilator end and tip when used to open the vasculature, thereby allowing the sheath to enter without causing excessive trauma. Ideally, to avoid trauma, the transition between the dilator tip and the distal end of the sheath is 0.1 mm or less. However, this is not always achievable. In the case where the dilator is significantly longer than the sheath, the sheath and dilator assembly tend to be more tolerant of small manufacturing variations, particularly variations in the length of the dilator or sheath, but this is not always achievable for shorter lengths.

[0009] In addition, not all sheath and dilator types can tolerate manufacturing variations. For an introducer sheath having multiple layers, it is difficult (if not impossible) to insert a tapered tip into an introducer sheath having layers that slide against each other. To prevent excessive movement of the layers, there is often a stepped gap between a typical dilator tip and the sheath. To overcome this, a dilator tip with a rounded arrow distal end shape is used to provide a smooth transition between the dilator and the sheath.

[0010] Where an arrow-type dilator tip is used, there is still a potential gap between the arrow dilator and the sheath caused by small manufacturing variations, which can create a flesh entrapment point during insertion of the dilator and sheath into the body.

[0011] Therefore, a mechanism is needed to position the dilator tip relative to the introducer sheath to minimize the pinch points created by gaps or edges at the transition between the introducer sheath and the dilator. Summary of the invention

[0012] Embodiments of the present invention are directed to a vascular dilator positioning assembly comprising: a gripping portion including a wall having an outer wall surface and an inner wall surface, the wall having a proximal edge defining a proximal opening, a distal edge defining a distal opening, and a cavity formed through the wall, a user-operable actuator positioned about the proximal edge, and a vascular dilator including an elongated tube having a proximal end attached to the actuator and a distal end attached to a dilator tip, wherein the actuator is configured to move the dilator tip distally from a retracted position to an extended position when the actuator is activated, and is configured to return the dilator tip to the retracted position when the actuator ceases to be activated.

[0013] As used herein, the terms "proximal" and "distal" are to be understood as terms that are opposite to the direction of use of the article to which they refer. The term "distal" is to be understood to refer to the end of the article that first enters the patient, while the term "proximal" is to be understood to refer to the end opposite the "distal" end. For example, the "distal end" may be closest to the dilator tip, such that in use, the distal end is closest to the patient and the proximal end is closest to the user, the "proximal" end also being closest to the actuator.

[0014] In an embodiment, the actuator has a button positioned about a proximal edge and an actuator core configured to engage the wall, wherein the actuator is configured to move the dilator tip distally from a retracted position to an extended position when a force is applied to the button, and is configured to return the dilator tip to the retracted position when the force is released from the button.

[0015] Preferably, the actuator core comprises a plug portion, the width of which spans the width of the grip portion cavity. The plug portion may be configured as a plate or a plug, and may be configured to plug the grip portion cavity. The plug portion may guide the movement of the expander tip.

[0016] The dilator tip is preferably substantially conical, tapering toward a point at the distal end. More preferably, the dilator tip is arrow-shaped and comprises two substantially conical portions, wherein a first conical portion tapers outwardly from the proximal end toward a maximum width, and a second portion tapers inwardly toward a rounded tip at the distal end. Alternatively, the dilator tip may have a substantially uniform width along its length, with a flat proximal end surface and a rounded tip at its distal end.

[0017] Sheaths used with embodiments of the present invention preferably include a semi-rigid layer to prevent significant longitudinal wrinkling of the sheath, but may alternatively include a semi-rigid element configured to substantially maintain the length of the sheath.Configurations including single layer sheaths and multi-layer sheaths may be suitable for the present invention.

[0018] In some embodiments, the actuator core is configured to occupy a space within the grip cavity.

[0019] In an embodiment, the vessel dilator positioning assembly comprises a resilient biasing element for biasing the dilator tip relative to the wall. In a further embodiment, the resilient biasing element is a spring having a spring rate between about 0.1 N / mm and 10 N / mm.

[0020] Preferably, the mounting force at maximum deflection is between about 0.1 N and 10 N. More preferably, the spring rate of the resilient biasing element is between 1 N / mm and 3 N / mm, and the mounting force at maximum deflection ranges from 0.5 N to 6.5 N. Most preferably, the spring rate of the resilient biasing element is about 0.6 N / mm.

[0021] In alternative embodiments, the resilient biasing element may be an air bag, rubber plug, elastic strip, or repelling magnet that compresses and biases toward expansion when a force is applied thereto, with the force per distance ranging between approximately 0.1N / mm to 10N / mm or the installed force at maximum deflection ranging between 0.1N to 10N.

[0022] In some embodiments, the inner wall surface comprises one or more protrusions. The protrusions are preferably configured such that a space is formed between the actuator core having the plug portion and the one or more protrusions for retaining the compressible biasing element in the space.

[0023] In further embodiments, a portion of the actuator core is shaped to occupy a space across the width of the grip cavity, enabling the actuator to slide within the grip cavity, and the resilient biasing element occupies a space substantially defined by an outer surface of the actuator core and an inner surface of the wall.

[0024] Embodiments of the present invention may further include: an expander sheath circumferentially surrounding the slender tube, the expander sheath having a proximal sheath end and a distal sheath end, wherein the actuator is configured to move the expander tip distally from a retracted position to an extended position to widen the gap between the expander sheath and the expander tip when a force is applied to a button, and the actuator is configured to partially return the expander tip to an intermediate rest position when the force is released from the button, thereby closing the gap between the expander sheath and the expander tip.

[0025] Applying the force on the button is preferably a user controlled thumb or finger press, wherein the user receives tactile feedback from the resilient biasing element and can control the release of the force for controlled retraction of the dilator tip.

[0026] The retracted position is preferably such that the expander tip is partially within the expander sheath. The extended position is preferably such that the expander tip has completely left the expander sheath to expose the proximal end of the expander tip and create a gap between the expander tip and the expander sheath. The intermediate rest position is preferably between the retracted position and the extended position and is defined by the point at which the surface of the expander tip abuts the expander sheath.

[0027] In further embodiments, the dilator sheath comprises a semirigid inner layer and an elastomeric outer layer, and the dilator tip is configured to abut the semirigid inner layer at an intermediate location, thereby providing a substantially smooth outer surface across the elastomeric outer layer and the dilator tip.

[0028] The abutment of the expander tip against the semi-rigid inner layer can be at any surface of the expander tip. Preferably, the expander tip abuts the semi-rigid inner layer in the conical surface of the proximal conical portion, but alternatively, the semi-rigid inner layer can abut a flat surface at the proximal end of the expander tip or abut a protrusion around the expander tip.

[0029] In a further preferred embodiment, the elastic biasing element is a spring having a spring rate between about 0.1 N / mm and 10 N / mm.

[0030] Embodiments of the present invention are directed to a vascular dilator positioning system, the vascular dilator positioning system comprising: a gripping portion, the gripping portion comprising a wall having an outer wall surface and an inner wall surface, the wall having a proximal edge defining a proximal opening, a distal edge defining a distal opening, and a cavity formed through the wall, a user-operable actuator positioned about the proximal edge, and a vascular dilator, the vascular dilator comprising an elongated tube, a proximal end of the elongated tube being attached to the actuator and a distal end of the elongated tube being attached to a dilator tip, wherein the actuator is configured to move the dilator tip distally from a retracted position to an extended position when the actuator is activated, and is configured to return the dilator tip to the retracted position when the actuator ceases to be activated.

[0031] In an embodiment, the vessel dilator positioning assembly comprises a resilient biasing element for biasing the dilator tip relative to the wall. In a further embodiment, the resilient biasing element is a spring having a spring rate between about 0.1 N / mm and 10 N / mm.

[0032] In an embodiment, the actuator has a button positioned about a proximal edge and an actuator core configured to engage the wall, wherein the actuator is configured to move the dilator tip distally from a retracted position to an extended position when a force is applied to the button, and is configured to return the dilator tip to the retracted position when the force is released from the button.

[0033] Additional embodiments may include a dilator sheath circumferentially surrounding the elongated tube, the dilator sheath having a proximal sheath end and a distal sheath end, wherein the actuator is configured to move the dilator tip distally from a retracted position to an extended position to widen the gap between the dilator sheath and the dilator tip when a force is applied to a button, and the actuator is configured to partially return the dilator tip to an intermediate resting position when the force is released from the button to close the gap between the dilator sheath and the dilator tip.

[0034] In some embodiments, the dilator sheath comprises a semirigid inner layer and an elastomeric outer layer, and the dilator tip is configured to abut the semirigid inner layer in an intermediate resting position, thereby providing a substantially smooth outer surface across the elastomeric outer layer and the dilator tip.

[0035] An embodiment of the present invention is directed to a method of using a vascular dilator positioning assembly, the method comprising the steps of obtaining a gripping portion, the gripping portion comprising a wall having an outer wall surface and an inner wall surface, the wall having a proximal edge defining a proximal opening, a distal edge defining a distal opening, and a cavity formed through the wall, and a user-operable actuator positioned about the proximal edge; attaching a proximal end of a vascular dilator comprising an elongated tube to the actuator and attaching a distal end of the vascular dilator to a dilator tip; placing a dilator sheath circumferentially around the elongated tube, the dilator sheath having a proximal sheath end and a distal sheath end; and activating the actuator to move the dilator tip distally from a retracted position to an extended position to widen a gap between the dilator sheath and the dilator tip; and deactivating the actuator to return the dilator tip to the retracted position.

[0036] In an embodiment, the method comprises the steps of assembling a gripping portion, an actuator and a resilient biasing element for biasing the dilator tip relative to the wall.

[0037] In an embodiment, the actuator has a button positioned around the proximal edge and an actuator core configured to engage the wall. The step of activating the actuator includes applying a force to the button to move the dilator tip distally from the retracted position to the extended position to widen the gap between the dilator sheath and the dilator tip. The step of deactivating the actuator includes releasing the force on the button to partially return the dilator tip to the intermediate rest position, thereby closing the gap between the dilator sheath and the dilator tip.

[0038] In another method, the expander sheath includes a semi-rigid inner layer and an elastomeric outer layer, and the expander tip is configured to abut the semi-rigid inner layer at an intermediate static position to provide a substantially smooth outer surface across the elastomeric outer layer and the expander tip; and the elastic biasing element is a spring having a spring stiffness between approximately 0.1N / mm and 10N / mm.

[0039] An embodiment of the present invention is directed to a method of assembling a vascular dilator positioning system, the method comprising the steps of obtaining a gripping portion including a wall having an outer wall surface and an inner wall surface, the wall having a proximal edge defining a proximal opening, a distal edge defining a distal opening, and a cavity formed through the wall; obtaining an actuator positioned about the proximal edge; attaching a proximal end of a vascular dilator including an elongated tube to an actuator core and attaching a distal end of the vascular dilator to a dilator tip; and placing a dilator sheath circumferentially around the elongated tube, the dilator sheath having a proximal sheath end and a distal sheath end.

[0040] In an embodiment, the method comprises the step of engaging a gripping portion with an actuator and a resilient biasing element for biasing the dilator tip relative to the wall.

[0041] In other methods, the resilient biasing element is a spring having a spring rate between about 0.1 N / mm and 10 N / mm.

[0042] A broad range of embodiments of the present invention will now be described with reference to the accompanying drawings together with the examples and preferred embodiments disclosed in the detailed description. The present invention can be implemented in many different forms and should not be construed as limited to the embodiments described herein. These embodiments are provided by way of illustration only so that this disclosure will be comprehensive, complete and will convey the full scope and breadth of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 A front view of a prior art dilator assembly is provided, showing the prior art introducer sheath and collar in phantom transparency. A detailed view of portion A is provided in Detail A.

[0044] Figure 2a - Figure 2c Provided Figure 1 Detail A is a front cross-sectional view of a prior art dilator and sheath assembly. Figure 2a A prior art dilator tip is shown during initial insertion into an incision. Figure 2b A prior art dilator tip is shown after insertion. Figure 2c A prior art sheath is shown during insertion.

[0045] Figure 3 A side perspective view of a dilator according to an embodiment of the present invention is provided. Detail B provides an enlarged view of the dilator tip.

[0046] Figure 4 A side perspective exploded view of a dilator and introducer sheath assembly according to an embodiment of the present invention is provided.

[0047] Figure 5A front cross-sectional view of a dilator and introducer sheath assembly according to an embodiment of the present invention is provided. A detailed view of portion C is provided in Detail C.

[0048] Figure 6a - Figure 6b A detailed side perspective view of the proximal end of a dilator and introducer sheath is provided in accordance with an embodiment of the present invention. Figure 6a The expander is shown in detail. Figure 6b The dilator and introducer sheath assembly are shown in detail.

[0049] Figure 7a - Figure 7c A front cross-sectional view of a dilator and introducer sheath assembly according to an embodiment is provided. Figure 7a A detail of the dilator tip prior to actuation of the biasing element is provided. A detailed view of portion D is provided in Detail D. Figure 7b A detail of the dilator tip when the biasing element is fully actuated is provided. A detailed view of portion E is provided in Detail E. Figure 7c A detail of the dilator tip after the biasing element is deactivated is provided. A detailed view of portion F is provided in Detail F.

[0050] Figure 8a - Figure 8c Provided based on Figure 7c Detail F is a front cross-sectional view of a dilator and sheath assembly of an embodiment of the present invention. Figure 8a The dilator tip is shown initially inserted into the incision. Figure 8b The dilator tip is shown after insertion. Figure 8c The sheath is shown during insertion.

[0051] Fig. 9 A flow chart is provided for a method for use with a dilator positioning assembly according to an embodiment of the present invention.

[0052] Several embodiments of the invention are described in the following examples. DETAILED DESCRIPTION Prior art

[0053] Figure 1 A front view of a prior art dilator 100 assembly is provided, showing a prior art introducer sheath 150 in phantom transparency. Detail A provides an enlarged front view of the dilator tip 130 and sheath. The dilator 100 is a tubular device for insertion into a blood vessel opening to reduce trauma while dilating the vessel for introduction of the introducer sheath 150.

[0054] In many prior art dilator and introducer sheath assemblies of this type, the design lengths of both the dilator 100 and the introducer sheath 150 are such that when the dilator hub 110 is attached to the collar 151, the distal end 153 of the sleeve 152 is nominally positioned to contact the proximal end of the tapered head 130 to provide a substantially smooth transition between the distal end of the sleeve and the tapered head.

[0055] Detail A shows a detailed view of the distal end 153 of the sleeve 152 and the proximal ends of the introducer sheath 150 and the tapered head 130 of the dilator 100, respectively. Although the design lengths of both the dilator 100 and the introducer sheath 150 nominally position the tapered head 130 at the distal end 153 of the sleeve 152, manufacturing errors in both the dilator 100 and the introducer sheath 150 may result in a gap 140 between the two. The presence of the gap 140 may prevent a smooth transition between the tapered head 130 and the sleeve 152, and may cause the skin and tissue 210 to get stuck in the gap 140 against the distal end 153.

[0056] Figure 2 provides Figure 1 A front cross-sectional view of a prior art dilator and sheath assembly is shown in detail A of FIG. 1 to provide a visual description of the prior art problems associated with the presence of gap 140 . Figure 2a The prior art dilator 100 and introducer sheath 150 assembly is shown during initial insertion into an incision in tissue 210 of a patient 200. The tapered head 130 provides smooth dilation of the incision in tissue 210, but manufacturing tolerances create a gap 140 between the tapered head 130 and the distal end 153.

[0057] Figure 2b The advancing insertion of the prior art dilator 100 and introducer sheath 150 assembly is shown with the tapered head 130 further inserted into the tissue 210. The tissue 210 has a certain degree of elasticity which exerts pressure on the tapered head 130. When there is a gap 140 at the proximal end of the tapered head 130, the tissue 210 conforms to the shape of the tapered head 130 and enters the gap 140 without a smooth transition between the tapered head 130 and the sleeve 152.

[0058] Figure 2c The final entrapment of the skin and tissue 210 at the incision point against the distal end 153 of the prior art introducer sheath 150 is shown. The entrapment of the skin and tissue 210 causes excessive trauma or prevents further insertion of the prior art dilator 100 and introducer sheath 150 assembly. In some cases, either of these possibilities results in insertion failure, requiring removal of the dilator 100 and introducer sheath 150 assembly and repeated attempts, which itself can increase trauma and contribute to the overall risk profile.

[0059] The invention described herein is directed to ameliorating this problem often associated with such prior art devices. According to the embodiment of the present invention

[0060] The embodiments are described in detail below with reference to the accompanying drawings. The exemplary embodiments are described to show certain aspects and embodiments of the present invention, rather than to limit the scope thereof as defined by the claims. It will be appreciated by those skilled in the art that multiple equivalent variations of the various features provided in the following description may be possible.

[0061] Figure 3 A side perspective view of a dilator 300 is provided. The dilator 300 is generally composed of a dilator hub 310 at the proximal end 301 of the dilator, a tapered head 330 at the distal end 302 of the dilator, and a dilator body 320 between the proximal end and the distal end of the dilator. A lumen from the proximal end 301 to the distal end 302 of the dilator 300 allows wires and small instruments to pass therethrough.

[0062] The expander hub 310 provides an attachment point for an introducer sheath (not shown) and allows an operator to manipulate the expander 300 during insertion of the expander into the introducer sheath. The expander hub 310 is a rigid annular structure having a larger diameter portion 311 and a smaller diameter portion 312. The smaller diameter portion 312 is shaped to fit within the introducer sheath collar. The expander hub 310 further includes: a securing device implemented as a bayonet fitting 313, which is formed on the surface of the smaller diameter portion 313 of the expander hub 310 body; and a button 340, which is slidably inserted into the larger diameter portion 311 of the expander hub 310 and is coupled to the larger diameter portion by a biasing element (not shown) implemented as a spring, one end of the biasing element being attached to the button 340 and the other end of the biasing element being attached to the expander hub 310.

[0063] The dilator hub 310, button 340, dilator body 320 and tapered head 330 contain lumens therethrough so that wires and small instruments can be delivered to the vessel. Detail B provides details of the tapered head 330, which is further used to facilitate insertion of the dilator 300 into the introducer sheath. The tapered head 330 is substantially conical or arrow-shaped, tapering outwardly from the distal end diameter of the dilator body 320 at the interface 331 between the tapered head 330 and the dilator body 320 to the maximum diameter of the tapered head 330, and tapering inwardly from the maximum diameter of the tapered head 330 to a rounded apex at the distal end of the tapered head 330.

[0064] The space between the interface 331 between the tapered head 330 and the dilator body 320 and the maximum diameter of the tapered head 330 provides a grip point for the patient's blood vessel when introduced with the sheath.

[0065] The expander body 320 is substantially cylindrical and is attached to a tapered head 330 at a distal end and enters the expander hub 310 at a proximal end where it is attached to a button 340. The coupling between the button 340 and the biasing element allows the expander body 320 to slidably move longitudinally relative to the expander hub 310.

[0066] The components of the expander 300 are composed of biocompatible polymers, such as polycarbonate, polypropylene, acrylonitrile butadiene styrene, polyethylene, polyamide, or polyamide blends. The expander body 320 may further include metal or synthetic braid reinforcements to provide increased rigidity. These components may incorporate additives or elements (such as metallic components or fillers) to improve opacity under x-ray imaging.

[0067] Figure 4 A side perspective exploded view of the components of the dilator 300 and introducer sheath 400 assembly according to a preferred embodiment of the present invention is provided. The dilator 300 generally includes a dilator hub 310, a button 340, a securing device 313, a biasing element implemented as a 0.1N / mm to 10N / mm conventional stainless steel coil spring 350, a dilator body 320, and a tapered head 330. The introducer sheath 400 generally includes a rigid annular collar 410, an elongated double-layer sleeve 420, and a securing fitting implemented in a bayonet receiver 440, which is suitable for receiving the securing device 313 and securing the dilator 300 to the bayonet receiver.

[0068] The introducer sheath 400 is generally composed of two main components: a rigid annular collar 410 and an elongated double-layer sleeve 420. The collar 410 is a hollow structure that is configured to allow material to be fed into the interior cavity of the sleeve 420 through the wider opening of the sleeve 420. The collar 410 is formed of a rigid material to allow a user to manipulate the collar 410 and pass an object or material therethrough. The collar 410 includes a securing fitting 440 and terminates in an opening that is shaped so that the sleeve 420 can be placed and secured therein, thereby connecting the two components.

[0069] After the dilator 300 is inserted into the introducer sheath 400, the dilator hub 310 is securely attached to the collar 410 by engaging the securing feature 313 to the securing fitting 440 to position the conical head 330 relative to the distal end 430 of the sleeve 420 and prevent further relative movement of the conical head.

[0070] Figure 5A front cross-sectional view of the dilator 300 and the introducer sheath 400 in an assembled arrangement is provided. The assembly of the dilator 300 and the introducer sheath 400 is such that the dilator body 320 is surrounded by a length of the sleeve 420 which nominally abuts the proximal end of the conical head 330. The proximal end of the dilator hub 310 has a larger diameter portion 311 and the distal end 312 of the dilator hub has a smaller diameter portion, wherein the smaller diameter portion 312 is shaped to be slidably inserted into the collar 410 and the larger diameter portion is shaped such that it then abuts the proximal end of the collar 410.

[0071] The button 340 is formed as an integral annular component, the shape of which is determined to generally include: a pusher 341 at its proximal end, the shape of which is determined to accommodate a syringe connector therein; an actuator core 343 connected thereto; a hook ridge 342 at the interface between the pusher 341 and the actuator core 343; a plunger body 344 at the distal end of the actuator core 343; and a plunger stop 345 at the distal end of the button 340.

[0072] The pusher 341 is shaped for tactile engagement by a user to slidably push the button 340 within the larger diameter portion 311, with a central cavity therethrough to receive wires and instruments. The actuator core 343 is substantially cylindrical, with a central cavity therethrough. The diameter of the actuator core 343 provides space between the actuator core 343 and the larger diameter portion 311 to fit the spring 350. The hook spine 342 is a portion of the actuator core 343 that is larger in diameter and is configured to slidably fit within the larger diameter portion 311 and contain the spring 350 within the space between the actuator core 343 and the larger diameter portion 311.

[0073] The plunger body 344 is substantially cylindrical with a central cavity therethrough. The plunger body has a smaller diameter than the actuator core 343 and is shaped to fit within and extend through the smaller diameter portion 312. The plunger stop 345 is shaped to strike a surface 312a within the smaller diameter portion 312 to retain the button 340 within the dilator hub 310.

[0074] The spring 350 is a coiled spring steel having a coil proximal end 351 and a coil distal end 352. The spring 350 is sized to fit slidably within the larger diameter portion 311 with a gauge sized to fit between the actuator core 343 and the larger diameter portion 311. The coil proximal end 351 abuts against the hook ridge 342 and exerts a force thereon. The coil distal end 352 is attached at the interface between the larger diameter portion 311 and the smaller diameter portion 312 so that expansion is toward the coil proximal end 351.

[0075] Figure 6a and Figure 6b Provided based on Figure 4 and Figure 5 A detailed side perspective view of the proximal components of the dilator 300 and introducer sheath 400 of the preferred embodiment of the present invention is shown.

[0076] like Figure 6a As shown, the expander hub 310 is a substantially tubular rigid member having a larger diameter portion 311 at its proximal end, a smaller diameter portion 312 at its distal end, and containing a biasing element implemented as a spring 350 (not shown) within and around the inner circumference of the larger diameter portion 311 of the expander hub. A button 340 is slidably inserted into the expander hub 310 and abuts the spring 350 such that further entry into the expander hub 310 is blocked. The expander body 320 is coupled to the button 340 such that actuation of the button 340, as caused by the bias of the spring 350, effects longitudinal movement of the expander body 320 and the tapered head 330 attached thereto toward the distal end 302. A securing means, implemented as a bayonet-type fitting 313, is integrally formed with the smaller diameter portion 312 of the expander hub 310, which allows the expander hub 310 to be secured to the introducer sheath 400.

[0077] The expansion device 300 and the introducer sheath 400 are fixedly connected at Figure 6b Detailedly shown in FIG. 3 , the bayonet fitting of the fastening device 313 is inserted into the corresponding fastening fitting 440 and fastened to the corresponding fastening fitting.

[0078] The sleeve 420 is double layered, having an outer elastomeric layer that applies outward resistance to a semi-rigid inner layer. The proximal end of the sleeve 420 is attached to the rigid collar 410. The securing fitting 440 is attached to the proximal end of the collar 410 and provides a corresponding fitting for the securing device 313. The securing engagement of the securing device 313 with the securing fitting 440 provides an anchor point, thereby allowing the expander body 320 and the tapered head 330 to move relative to the sleeve 420 when the button 340 is actuated and deactivated.

[0079] Figures 7a to 7cA front cross-sectional view of the dilator 300 and introducer sheath 400 is provided and details the interaction of the tapered head 330 and sleeve 420 at different actuation points of the button 340 , wherein the dilator hub 310 is attached to the collar 410 via engagement of the securing feature 313 with the securing fitting 440 .

[0080] Once the dilator 300 is inserted into the introducer sheath 400, the securing means 313 engages the securing fitting 440 to be secured thereto. The button 340 and the dilator body 320 are coupled for combined longitudinal movement relative to the introducer sheath 400. The button 340 is further coupled to a spring 350 to allow combined longitudinal movement of the button 340 and the dilator body 320 toward the distal end 302 of the introducer sheath 400 when the button 340 is actuated and to provide a return force to the proximal end 301 when the button is deactivated.

[0081] Figure 7a A front cross-sectional view of the expander 300 and the introducer sheath 400 is provided after the expander 300 is initially inserted into the introducer sheath 400 and secured to each other but before the button 340 is actuated. Thus, the spring 350 is in a substantially uncompressed state and the plunger stop 345 rests on the surface 312a. The length of the expander body 320 is such that the tapered head 330 is not fully withdrawn from the distal end of the sleeve 420 at this time, as detailed in Detail D.

[0082] Depressing the button 340 contracts the spring 350 and pushes the tapered head 330 out of the distal end of the sleeve 420 . Figure 7b A front cross-sectional view of the expander 300 and the introducer sheath 400 is provided after the expander 300 is initially inserted into the introducer sheath 400 and secured thereto and during maximum actuation of the button 340. Thus, the spring 350 is in maximum compression and the expander body 320 is at its maximum travel. At this point, the conical head 330 has completely withdrawn from the distal end of the sleeve 420, leaving a gap therebetween, as detailed in Detail E.

[0083] Releasing the button 340 allows the spring 350 to expand and the tapered head 330 to return with its distal end against the sleeve 420 to create a smooth transition between the tapered head and the sleeve. Figure 7cA front cross-sectional view of the expander 300 and the introducer sheath 400 is provided after the expander 300 is initially inserted into the introducer sheath 400 and secured thereto and after the button 340 is released from its maximum actuation to an intermediate point. The spring 350 is released from maximum compression to an intermediate position. At this point, the conical head 330 has been retracted against the sleeve 420 and is prevented from further retraction due to the rigidity of the sleeve 420 and the low force exerted on the sleeve by the spring 350. The gap between the conical head 330 and the sleeve 420 has been closed, leaving a substantially smooth transition between the conical head 330 and the sleeve 420, as detailed in Detail F.

[0084] Figure 8 provides the Figure 7c A front cross-sectional view of the dilator 300 and sheath 400 assembly is shown in detail F to provide a visual depiction of the present invention in use, wherein the dilator 300 and introducer sheath 400 assembly is inserted into an incision in tissue 210 of a patient 200 after the button 340 has been actuated and deactuated to position the conical head 330 relative to the sleeve 420. Figure 8a Dilator 300 and introducer sheath 400 are shown wherein, during initial insertion into an incision in tissue 210 of patient 200, tapered head 330 rests against the distal end of sleeve 420 due to the expansion force of spring 350. Tapered head 330 provides smooth dilation of the incision in tissue 210 to reduce trauma.

[0085] Figure 8b The initial interaction between the cutout in the tissue 210 and the tapered head 330 upon further insertion is shown. The tissue 210 has a degree of elasticity that exerts an inward pressure on the tapered head 330. When there is no gap at the proximal end of the tapered head 330, the tissue 210 conforms to the shape of the tapered head 330, but is prevented from appreciably entering the path of the sleeve 420 by the substantially smooth transition between the tissue and the tapered head.

[0086] Figure 8c The result is shown to be that the skin and tissue 210 of the patient 200 does not get stuck at the incision point against the distal end of the cannula 420. The substantially smooth transition from the tapered head 330 to the sleeve 420 allows the tapered head 330 and sleeve 420 to enter the incision in the tissue 210 without getting stuck and causing undue trauma, and subsequently reducing the risk of insertion failure, thereby reducing the overall risk profile of the patient 200.

[0087] Fig. 9 A flow chart is provided to illustrate Figures 3 to 8c901, an introducer sheath suitable for assembly with a dilator according to an embodiment of the present invention is obtained, and in step 902 the dilator itself is obtained.

[0088] Step 903 requires the expander tip to be inserted into the proximal end of the introducer sheath so that when fully inserted, the expander tip partially leaves the distal end of the introducer sheath. Then, step 904 requires the expander to be secured to the introducer sheath by engaging the securement device of the expander with the securement fitting of the introducer sheath.

[0089] At step 905, the user actuates or presses a button on the dilator to compress the spring coupled thereto and fully extend the dilator tip relative to the introducer sheath. This has the effect of fully exposing the dilator tip and creating a gap between the dilator tip and the distal end of the introducer sheath.

[0090] At step 906, the user deactivates or releases the button on the dilator, thereby allowing the spring to decompress the dilator tip and retract toward the proximal end of the introducer sheath. This has the effect of pulling the dilator tip against the distal end of the introducer sheath and closing the gap between the dilator tip and the introducer sheath to create a substantially smooth transition between the dilator tip and the introducer sheath.

[0091] At step 907, a dilator and introducer sheath assembly according to an embodiment of the present invention is inserted into the patient's body, such as Figures 8a to 8c As displayed.

[0092] In this specification, the word "comprise" or variations such as "include" or "comprising" will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

[0093] It should be understood that the terms "fastener" or "fastening", "coupling" or "sealing" can be used interchangeably when used alone or with other terms (such as "device" or other terms), where a person skilled in the art considers the interpretation of the term to be functionally interchangeable with the other term. Further, the use of one of the above terms does not exclude the interpretation when the other term is included.

[0094] As described herein, various devices and components of the devices can be provided in various sizes and / or dimensions as required. Suitable sizes and / or dimensions will vary according to the specifications or fields of use of the connecting components, which specifications can be selected by those skilled in the art.

[0095] It will be appreciated that features, elements and / or characteristics described with respect to one embodiment of the disclosure may be used with other embodiments of the invention, as desired.

[0096] Although the preferred embodiments of the present disclosure have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the disclosure and the accompanying claims.

[0097] It should be understood that when an element or layer is referred to as being "on" or "in" another element or layer, the element or layer can be directly on or within the other element or layer or intervening elements or layers. In contrast, when an element is referred to as being "directly on" or "directly within" another element or layer, there are no intervening elements or layers.

[0098] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0099] It should be understood that, although the terms first, second, third, etc. can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms are only used to distinguish an element, component, region, layer or section from another region, layer or section. Therefore, without departing from the teaching content of the present disclosure, the first element, component, region, layer or section can be referred to as the second element, component, region, layer or section.

[0100] For ease of description, spatial relative terms such as "lower", "upper", "top", "bottom", "left", "right", etc. may be used herein to describe the relationship between an element or feature and another one or more elements or features shown in the accompanying drawings. It should be understood that, in addition to the orientations depicted in the accompanying drawings, spatial relative terms are intended to cover different orientations of structures in use or operation. For example, if the device in the accompanying drawings is turned over, the element described as "lower" relative to other elements or features will be oriented "up" relative to the other elements or features. Therefore, the exemplary term "lower" can include both upper and lower orientations. The device can be oriented in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptors used herein should be interpreted accordingly.

[0101] The terms used in this article are only for the purpose of describing specific embodiments, and are not intended to limit the present disclosure. As used herein, the singular forms "a / an" and "the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should be further understood that the terms "comprise", "include" and / or "contain" when used in this specification specify the presence of stated features, wholes, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, parts and / or their groups.

[0102] Embodiments of the present specification are described herein by reference to figures and / or cross-sectional illustrations that are, for example, schematic illustrations of preferred embodiments (and intermediate structures) of the present specification. As such, variations in the shapes of the illustrations, for example due to manufacturing techniques and / or tolerances, are contemplated. Therefore, the embodiments of the present specification should not be construed as limited to the specific shapes of the components shown herein, but rather include deviations in shapes, for example due to manufacturing.

[0103] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those commonly understood by those skilled in the art to which the present disclosure belongs. It should be further understood that terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and will not be interpreted in an idealized or overly formal sense unless explicitly defined as such herein.

[0104] Any reference in this specification to "one embodiment," "an embodiment," "an example embodiment," etc. means that a particular feature, structure, or characteristic described in conjunction with the embodiment is included in at least one embodiment of this specification. Such phrases appearing in different places in the specification do not necessarily refer to the same embodiment. Further, when a particular feature, structure, or characteristic is described in conjunction with any embodiment, those skilled in the art have the right to implement and / or use such feature, structure, or characteristic in conjunction with other embodiments.

[0105] Embodiments are also intended to include or otherwise encompass methods of use and methods of manufacture of any or all of the elements disclosed above.

[0106] Although the present invention has been described above with respect to specific embodiments, it should be understood that the present invention is not limited to the embodiments disclosed herein. After reading the teachings of this disclosure, many modifications and other embodiments of the present invention will occur to those skilled in the art to which the present invention belongs, and these modifications and other embodiments are intended to be covered by both this disclosure and the appended claims.

[0107] All publications mentioned in this specification are incorporated herein by reference. Any discussion of documents, acts, materials, devices, articles and the like has been included in this specification solely for the purpose of providing a context for the present invention. It is not an admission that any or all of these matters form part of the prior art base or are common general knowledge in the field relevant to the present invention by virtue of its existence in Australia or elsewhere before the priority date of the claims of this application.

[0108] Rather, the scope of the present invention should be determined by proper interpretation and construction of the appended claims and their legal equivalents, as understood by those skilled in the art relying on the disclosure in this specification and the accompanying drawings.

Claims

1. A vascular dilator positioning assembly, comprising: a gripping portion including a wall having an outer wall surface and an inner wall surface, the wall having a proximal edge defining a proximal opening, a distal edge defining a distal opening, and a gripping cavity formed through the wall; a user-operable actuator positioned about said proximal edge; as well as a vascular dilator comprising an elongated tube having a proximal end attached to the actuator and a distal end attached to a dilator tip, wherein the actuator is configured to move the dilator tip distally from a retracted position to an extended position when the actuator is activated, and is configured to return the dilator tip to the retracted position when the actuator ceases to be activated.

2. The vascular dilator positioning assembly according to claim 1, characterized in that: Also included is a resilient biasing element for biasing the dilator tip relative to the wall.

3. The vascular dilator positioning assembly according to claim 2, characterized in that: The elastic biasing element is a spring having a spring rate between about 0.1 N / mm and 10 N / mm.

4. The vascular dilator positioning assembly according to claim 1, characterized in that: The actuator has a button positioned around the proximal edge and an actuator core configured to engage the wall, wherein the actuator is configured to move the dilator tip distally from the retracted position to the extended position when a force is applied to the button, and is configured to return the dilator tip to the retracted position when the force is released from the button.

5. The vascular dilator positioning assembly according to claim 4, characterized in that: The actuator core is configured to occupy a space within the grip cavity.

6. The vascular dilator positioning assembly according to claims 2 and 4, characterized in that: A portion of the actuator core is shaped to occupy a space across the width of the grip cavity so that the actuator can slide within the grip cavity, and The resilient biasing element occupies a space substantially defined by an outer surface of the actuator core and an inner surface of the wall.

7. The vascular dilator positioning assembly according to claim 4, characterized in that: include: A dilator sheath circumferentially surrounding the elongated tube, the dilator sheath having a proximal sheath end and a distal sheath end, wherein the actuator is configured to move the dilator tip distally from a retracted position to an extended position to widen a gap between the dilator sheath and the dilator tip when a force is applied to the button, and the actuator is configured to partially return the dilator tip to an intermediate resting position to close the gap between the dilator sheath and the dilator tip when the force is released from the button.

8. The vascular dilator positioning assembly according to claim 7, characterized in that: The dilator sheath includes a semirigid inner layer and an elastomeric outer layer, and the dilator tip is configured to abut the semirigid inner layer in the intermediate resting position to provide a substantially smooth outer surface across the elastomeric outer layer and the dilator tip.

9. A vascular dilator positioning system, comprising: a gripping portion including a wall having an outer wall surface and an inner wall surface, the wall having a proximal edge defining a proximal opening, a distal edge defining a distal opening, and a cavity formed through the wall; a user-operable actuator positioned about said proximal edge; as well as a vascular dilator comprising an elongated tube having a proximal end attached to the actuator and a distal end attached to a dilator tip, wherein the actuator is configured to move the dilator tip distally from a retracted position to an extended position when the actuator is activated, and is configured to return the dilator tip to the retracted position when the actuator ceases to be activated.

10. The vascular dilator positioning system according to claim 9, characterized in that: Also included is a resilient biasing element for biasing the dilator tip relative to the wall.

11. The vascular dilator positioning system according to claim 10, characterized in that: The elastic biasing element is a spring having a spring rate between about 0.1 N / mm and 10 N / mm.

12. The vascular dilator positioning system according to claim 11, characterized in that: The actuator has a button positioned around the proximal edge and an actuator core configured to engage the wall, wherein the actuator is configured to move the dilator tip distally from the retracted position to the extended position when a force is applied to the button, and is configured to return the dilator tip to the retracted position when the force is released from the button.

13. The vascular dilator positioning system according to claim 9, characterized in that: include: A dilator sheath circumferentially surrounding the elongated tube, the dilator sheath having a proximal sheath end and a distal sheath end, wherein the actuator is configured to move the dilator tip distally from a retracted position to an extended position to widen the gap between the dilator sheath and the dilator tip when a force is applied to a button, and the actuator is configured to partially return the dilator tip to an intermediate resting position when the force is released from the button to close the gap between the dilator sheath and the dilator tip.

14. The vascular dilator positioning system according to claim 13, characterized in that: The dilator sheath includes a semirigid inner layer and an elastomeric outer layer, and the dilator tip is configured to abut the semirigid inner layer in the intermediate resting position to provide a substantially smooth outer surface across the elastomeric outer layer and the dilator tip.

15. A method of using a vascular dilator positioning assembly, preferably according to claim 1, the method comprising the steps of: obtaining a gripping portion, the gripping portion comprising a wall having an outer wall surface and an inner wall surface, the wall having a proximal edge defining a proximal opening, a distal edge defining a distal opening, and a cavity formed through the wall, and a user-operable actuator positioned about the proximal edge; attaching a proximal end of a vascular dilator comprising an elongated tube to the actuator and attaching a distal end of the vascular dilator to a dilator tip; placing a dilator sheath circumferentially around the elongated tube, the dilator sheath having a proximal sheath end and a distal sheath end; as well as The actuator is activated to move the dilator tip distally from a retracted position to an extended position to widen a gap between the dilator sheath and the dilator tip, and the actuator is deactivated to return the dilator tip to the retracted position.

16. The method of using a vascular dilator positioning assembly according to claim 15, characterized in that: Also includes the steps: The gripping portion, the actuator, and a resilient biasing element for biasing the dilator tip relative to the wall are assembled.

17. The method of using a vascular dilator positioning assembly according to claim 15, characterized in that: The actuator has a button positioned about the proximal edge and an actuator core configured to engage the wall, Wherein, the step of activating the actuator comprises: applying a force to the button to move the dilator tip distally from a retracted position to an extended position to widen the gap between the dilator sheath and the dilator tip, and Wherein, the step of stopping activating the actuator comprises: Releasing the force on the button partially returns the dilator tip to the intermediate resting position, thereby closing the gap between the dilator sheath and the dilator tip.

18. The method of using a vascular dilator positioning assembly according to claim 15, characterized in that: The dilator sheath comprises a semi-rigid inner layer and an elastomeric outer layer, and the dilator tip is configured to abut the semi-rigid inner layer in an intermediate resting position to provide a substantially smooth outer surface across the elastomeric outer layer and the dilator tip; and The elastic biasing element is a spring having a spring rate between about 0.1 N / mm and 10 N / mm.

19. A method of assembling a vascular dilator positioning system, preferably according to claim 9, the method comprising the steps of: obtaining a gripping portion, the gripping portion comprising a wall having an outer wall surface and an inner wall surface, the wall having a proximal edge defining a proximal opening, a distal edge defining a distal opening, and a cavity formed through the wall; obtaining an actuator positioned about said proximal edge; attaching a proximal end of a vascular dilator comprising an elongated tube to the actuator core and attaching a distal end of the vascular dilator to a dilator tip; as well as A dilator sheath is placed circumferentially around the elongated tube, the dilator sheath having a proximal sheath end and a distal sheath end.

20. The method of assembling a vascular dilator positioning system according to claim 19, characterized in that: The method further comprises the steps of: The gripping portion is engaged with the actuator and a resilient biasing element for biasing the dilator tip relative to the wall.

21. The method of assembling a vascular dilator positioning system according to claim 20, characterized in that: The elastic biasing element is a spring having a spring rate between about 0.1 N / mm and 10 N / mm.

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