Patent Description:
What is needed therefore, is a safety mechanism that has a simplified construction reducing manufacturing complexity and associated costs, improved deployment reliability, and provide a more secure engagement between the obturator tip and a protective sheath. Embodiments disclosed herein include a safety mechanism and associated methods thereof to address the foregoing.

Disclosed herein is a safety mechanism including, an elongate medical device having a shaft extending along a longitudinal axis and defining a first outer diameter, the shaft including a notch extending annularly and defining a second outer diameter, less than the first outer diameter, a sheath including a body defining a sheath lumen configured to receive the elongate medical device therethrough, and a shroud extending axially and including a first sheath aperture and a second sheath aperture, and a clip configured to transition between a first configuration and a second configuration, the clip having a first arm, including a first tab, a first plate, and a first grip, the first tab including a first keyhole aperture, a second arm, including a second tab, a second plate, and a second grip, the second tab including a second keyhole aperture, and a biasing member extending from the first arm to the second arm and configured to bias the clip towards the second configuration, the elongate medical device extending through first keyhole aperture and the second keyhole aperture, the first grip extending through the first sheath aperture, and the second grip extending through the second sheath aperture.

In some embodiments, the first arm and the second arm are spaced in a radially outward position in the second configuration relative to the first configuration. In some embodiments, the first keyhole aperture includes a first lock aperture communicating with a first unlock aperture, and the second keyhole aperture includes a second lock aperture communicating with a second unlock aperture, one or both of the first lock aperture and the second lock aperture having a first inner diameter, and one or both of the first unlock aperture and the second unlock aperture having a second inner diameter larger than the first inner diameter. In some embodiments, the first inner diameter is less than the first outer diameter and equal to or larger than the second outer diameter, and the second inner diameter is equal to or larger than the first outer diameter.

In some embodiments, the first lock aperture and the second lock aperture are axially aligned when the clip is in the second configuration, and the first unlock aperture and the second unlock aperture are axially aligned when the clip is in the first configuration. In some embodiments, the first unlock aperture and the second unlock aperture are spaced radially outward relative to a central axial position in the second configuration. In some embodiments, the first lock aperture is disposed opposite the longitudinal axis from the second lock aperture in the first configuration. In some embodiments, the sheath body is configured to engage a recess of a needle hub, the shroud extends over an outer surface of the needle hub, one or both of the first grip and the second grip engaging an outer surface of the needle hub when the clip is in the first configuration.

In some embodiments, the first grip extends through first sheath aperture to engage a first grip recess disposed in an outer surface of the needle hub, and the second grip extends through second sheath aperture to engage a second grip recess disposed in an outer surface of the needle hub. In some embodiments, one or both of the first grip and the second grip is configured to disengage the needle hub in the second configuration. In some embodiments, the first grip engages the first sheath aperture and the second grip engages the second sheath aperture in both the first configuration and the second configuration.

In some embodiments, the sheath is in a longitudinally fixed position relative the elongate medical device and a distal tip of the sheath body extends distally of a distal tip of the elongate medical device when the clip is in the second configuration. In some embodiments, the first tab, the second tab, the first grip and the second grip extend perpendicular to the longitudinal axis, and the first plate and the second plate extend parallel to the longitudinal axis. In some embodiments, the clip is formed as a monolithic piece from one of a plastic, polymer, metal, alloy, or composite. In some embodiments, the elongate medical device includes one of an obturator, needle, cannula, trocar, or a stylet.

Also disclosed is a method of engaging a safety mechanism with a tip of an elongate medical device including, withdrawing the elongate medical device proximally along a longitudinal axis, through a first keyhole aperture disposed in a first tab of a clip, transitioning the clip from a first configuration to a second configuration, the clip fixedly engaging the elongate medical device in the second configuration to prevent any longitudinal movement therebetween, the clip coupled to a sheath, and disengaging a first grip from a needle hub to disengage the sheath from the needle hub, the first grip coupled to the first tab.

In some embodiments, the clip includes a biasing member configured to bias the clip towards the second configuration. In some embodiments, the method further includes sliding the first tab perpendicular to the longitudinal axis the elongate medical device extending through a first unlock aperture of the first keyhole aperture when the clip is in a first configuration, and extending through the lock aperture when the clip is in a second configuration. In some embodiments, the method further includes engaging the first lock aperture with a notch of the elongate medical device, the inner diameter of the first lock aperture being less than a first outer diameter of the elongate medical device and larger than a second inner diameter of the notch.

In some embodiments, the method further includes fixedly engaging a sheath, coupled to the clip, relative to the elongate medical device, a distal tip of the sheath extending distally of a distal tip of the elongate medical device. In some embodiments, the first grip engages a grip recess disposed in an outer surface of the needle hub when the clip is in the first configuration. In some embodiments, the sheath includes a body defining a sheath lumen configured to receive the elongate medical device there through, and a shroud extending axially and configured to engage an outer surface of the needle hub, the first grip slidably engaged with a sheath aperture disposed in the shroud in both the first configuration and the second configuration. In some embodiments, the clip is formed as a monolithic piece from one of a plastic, polymer, metal, alloy, or composite. In some embodiments, the elongate medical device includes one of an obturator, needle, cannula, trocar, or a stylet.

Also disclosed is a method of manufacturing a safety assembly including, forming a clip from a first material, the clip having a first arm, including a first tab, a first plate, and a first grip, the first tab including a first keyhole aperture, a second arm, including a second tab, a second plate, and a second grip, the second tab including a second keyhole aperture, and a biasing member extending from the first arm to the second arm, folding the first tab and the first grip through an angle of <NUM> degrees relative to the first plate, folding the second tab and the second grip through an angle of <NUM> degrees relative to the second plate, forming a sheath from a second material, the sheath including a body defining a lumen and a shroud including a sheath aperture extending therethrough, and coupling the clip to the sheath wherein one of the first grip or the second grip extends through the sheath aperture.

In some embodiments, the method further includes elastically deforming the elongate biasing member such that the first keyhole aperture axially aligns with the second keyhole aperture. In some embodiments, the first material is a sheet of metal and the second material is a polymer.

Also disclosed is a safety mechanism including, an elongate medical device having a shaft extending along a longitudinal axis and defining a first outer diameter, the shaft including a notch extending annularly and defining a second outer diameter, less than the first outer diameter, a sheath including a body defining a lumen configured to receive the elongate medical device therethrough, and a shroud extending axially and including a sheath aperture, and a clip configured to transition between a first configuration and second configuration, the clip including, an arm, including a tab, a plate, and a grip, the tab including a keyhole aperture, and a biasing member coupled to the plate and extending annularly about an outer surface of the sheath, and configured to bias the tab towards the second configuration, the elongate medical device extending through first keyhole aperture, the grip extending through the sheath aperture.

With respect to "proximal," a "proximal portion" or a "proximal-end portion" of, for example, a needle disclosed herein includes a portion of the needle intended to be near a clinician when the needle is used on a patient. Likewise, a "proximal length" of, for example, the needle includes a length of the needle intended to be near the clinician when the needle is used on the patient. A "proximal end" of, for example, the needle includes an end of the needle intended to be near the clinician when the needle is used on the patient. The proximal portion, the proximal-end portion, or the proximal length of the needle can include the proximal end of the needle; however, the proximal portion, the proximal-end portion, or the proximal length of the needle need not include the proximal end of the needle. That is, unless context suggests otherwise, the proximal portion, the proximal-end portion, or the proximal length of the needle is not a terminal portion or terminal length of the needle.

With respect to "distal," a "distal portion" or a "distal-end portion" of, for example, a needle disclosed herein includes a portion of the needle intended to be near or in a patient when the needle is used on the patient. Likewise, a "distal length" of, for example, the needle includes a length of the needle intended to be near or in the patient when the needle is used on the patient. A "distal end" of, for example, the needle includes an end of the needle intended to be near or in the patient when the needle is used on the patient. The distal portion, the distal-end portion, or the distal length of the needle can include the distal end of the needle; however, the distal portion, the distal-end portion, or the distal length of the needle need not include the distal end of the needle. That is, unless context suggests otherwise, the distal portion, the distal-end portion, or the distal length of the needle is not a terminal portion or terminal length of the needle.

As shown in <FIG>, and to assist in the description of embodiments described herein, a longitudinal axis extends substantially parallel to an axial length of a needle <NUM> extending from the driver <NUM>. A lateral axis extends normal to the longitudinal axis, and a transverse axis extends normal to both the longitudinal and lateral axes.

As used herein, the term "spring" is considered to include any type of spring or biasing member that may store potential mechanical energy. Exemplary biasing members can include compression springs, extension springs, torsion springs, constant force springs, flat spring, flexible members, rubber rings, rubber band, leaf spring, V-spring, cantilever spring, volute spring, Belleville spring, gas spring, gravity-propelled biasing members, combinations thereof or the like, and are considered to fall within the scope of the present disclosure.

Although the exemplary embodiments disclosed herein are described with respect to intraosseous (IO) access devices, systems, and methods thereof, it will be appreciated that embodiments disclosed herein can be used with various systems that require capturing a sharp tip of an elongate device to mitigate accidental stick injuries, without limitation.

<FIG> show an exemplary environment of use for a safety mechanism <NUM>, as described herein. <FIG> show an exploded view of an exemplary intraosseous access system ("system") <NUM>, with some components thereof shown in elevation (<FIG>) and other components shown in perspective (<FIG>). In an embodiment, the intraosseous access system <NUM> can be used to penetrate the skin tissues and underlying hard bone ("bone cortex") for intraosseous access, such as, for example to access the marrow of the bone and/or a vasculature of the patient via a pathway through an interior of the bone ("medullary cavity").

In an embodiment, the system <NUM> includes a driver <NUM> and an access assembly <NUM>. The driver <NUM> can be used to rotate the access assembly <NUM> and "drill" a needle <NUM> into the bone of a patient. In embodiments, the driver <NUM> can be automated or manual. As shown, the driver <NUM> is an automated driver <NUM>. For example, the automated driver <NUM> can be a drill that achieves high rotational speeds. In an embodiment, the intraosseous access system <NUM> can further include an obturator assembly <NUM>, a safety mechanism or shield <NUM>, and a needle assembly <NUM>, which may be referred to, collectively, as the access assembly <NUM>. The needle assembly <NUM> can include an access needle ("needle") <NUM> supported by a needle hub <NUM>, as described in more detail herein. In an embodiment, the obturator assembly <NUM> includes an obturator <NUM>. However, in some embodiments, the obturator <NUM> may be replaced with a different elongated medical instrument. As used herein, the term "elongated medical instrument" is a broad term used in its ordinary sense that includes, for example, such devices as needles, cannulas, trocars, obturators, stylets, and the like. Accordingly, the obturator assembly <NUM> may be referred to more generally as an elongated medical device assembly. In like manner, the obturator <NUM> may be referred to more generally as an elongated medical device.

In an embodiment, the obturator assembly <NUM> includes a coupling hub <NUM> that is attached to the obturator <NUM> in any suitable manner (e.g., one or more adhesives or overmolding). The coupling hub <NUM> can be configured to interface with the driver <NUM>, as further discussed below. The coupling hub <NUM> may alternatively be referred to as an obturator hub <NUM> or, more generally, as an elongated instrument hub <NUM>. In an embodiment, the safety mechanism <NUM> is configured to couple with the obturator <NUM> to prevent accidental needle stick injuries when the obturator is removed after placement of the needle <NUM>, as described in more detail herein.

In an embodiment, the needle assembly <NUM> includes a needle <NUM>. However, in some embodiments, the needle <NUM> may be replaced with a different instrument, such as, for example, a cannula, a tube, or a sheath, and/or may be referred to by a different name, such as one or more of the foregoing examples. Accordingly, the needle assembly <NUM> may be referred to more generally as a cannula assembly or as a tube assembly. In like manner, the needle <NUM> may be referred to more generally as a cannula.

In an embodiment, the needle assembly <NUM> includes a needle hub <NUM> that is attached to the needle <NUM> in any suitable manner. The needle hub <NUM> can be configured to couple with the obturator hub <NUM> and may thereby be coupled with the driver <NUM>. The needle hub <NUM> may alternatively be referred to as a cannula hub <NUM>. In an embodiment, a cap <NUM> may be provided to cover at least a distal portion of the needle <NUM> and the obturator <NUM> prior to use of the access assembly <NUM>. For example, in an embodiment, a proximal end of the cap <NUM> can be coupled to the obturator hub <NUM>.

With continued reference to <FIG>, the driver <NUM> may take any suitable form. The driver <NUM> may include a handle <NUM> that may be gripped by a single hand of a user. In an embodiment, the driver <NUM> further includes a coupling interface <NUM>, which is formed as a socket <NUM> that defines a cavity <NUM>. The coupling interface <NUM> can be configured to couple with the obturator hub <NUM>. In an embodiment, the socket <NUM> includes sidewalls that substantially define a hexagonal cavity into which a hexagonal protrusion of the obturator hub <NUM> can be received. Other suitable connection interfaces are also contemplated.

The driver <NUM> can include an energy source <NUM> of any suitable variety that is configured to energize the rotational movement of the coupling interface <NUM>. For example, in some embodiments, the energy source <NUM> may comprise one or more batteries that provide electrical power for the driver <NUM>. In some embodiments, the energy source <NUM> can comprise one or more springs (e.g., a coiled spring, flat spring, or the like) or other biasing member that may store potential mechanical energy that may be released upon actuation of the driver <NUM>.

The energy source <NUM> may be coupled with the coupling interface <NUM> in any suitable manner. For example, in an embodiment, the driver <NUM> includes an electrical, mechanical, or electromechanical coupling <NUM> to a gear assembly <NUM>. In some embodiments, the coupling <NUM> may include an electrical motor that generates mechanical movement from electrical energy provided by an electrical energy source <NUM>. In other embodiments, the coupling <NUM> may include a mechanical linkage to the gear assembly <NUM>. The driver <NUM> can include a mechanical coupling of any suitable variety to couple the gear assembly <NUM> with the coupling interface <NUM>. In other embodiments, the gear assembly <NUM> may be omitted.

Further details and embodiments of the intraosseous access system <NUM> can be found in <CIT>, <CIT>, <CIT>, and <CIT>.

<FIG> illustrate various details of an embodiment of a safety mechanism <NUM>. The safety mechanism <NUM> can be used with an intraossesous access system <NUM>, as described herein, for example, the safety mechanism <NUM> can be used in place of the safety shield <NUM>. However, it will be appreciated that embodiments of the safety mechanism <NUM> can be used with various needles, cannulas, trocars, stylets, obturators, or similar sharpened medical devices without limitation, and can be configured to prevent accidental needle-stick injuries.

As shown in <FIG>, in an embodiment, the safety mechanism <NUM> can generally include a clip <NUM> and a sheath <NUM>. A portion of the clip <NUM> can slidably engage the sheath <NUM> and transition between a first, or unlocked, configuration (<FIG>) and a second, or locked, configuration (<FIG>). In the first configuration, as shown in <FIG>, the clip <NUM> can slidably engage a shaft of the obturator <NUM> along a longitudinal axis thereof. Further, the clip <NUM> can also selectively engage the needle hub <NUM> and secure the sheath <NUM> thereto, preventing any relative longitudinal movement between the sheath <NUM> and the needle hub <NUM>.

As the obturator <NUM> is withdrawn proximally from the needle <NUM> and slides relative to the safety mechanism <NUM>, an annular notch ("notch") <NUM> aligns with a portion of the clip <NUM>, allowing the clip <NUM> to transition from the first configuration (<FIG>) to the second configuration (<FIG>). In the second configuration, the clip <NUM> is locked to the obturator <NUM>, preventing any relative longitudinal movement between the obturator <NUM> and safety mechanism <NUM>. Further, the clip <NUM> disengages the needle hub <NUM> allowing the obturator <NUM>, clip <NUM>, and sheath <NUM> assembly to separate from the needle hub <NUM>.

Advantageously, the clip <NUM> maintains the sheath <NUM> in a longitudinally fixed position relative to the tip of the obturator <NUM> preventing accidental stick injuries. Further, the safety mechanism <NUM> provides a simplified manufacturing process, and associated cost savings. Advantageously, the clip <NUM> requires only a relatively small surface area to contact the obturator <NUM>, reducing friction or "drag" therebetween as the obturator <NUM> is slid proximally. Further the edges of the clip <NUM> can be smoothed and/or beveled to further reduce the friction between the clip <NUM> and the obturator <NUM>. As such, less force is required to remove the obturator <NUM> from the needle <NUM> and can prevent the obturator <NUM> from becoming prematurely detached from the driver <NUM>. Advantageously, the engagement between the clip <NUM>, the sheath <NUM>, and the needle hub <NUM> in the first configuration (<FIG>) requires much higher override forces providing a much more robust interface, mitigating accidental failure of the safety mechanism <NUM>.

<FIG> show further details of the clip <NUM> of the safety mechanism <NUM>. <FIG> shows the clip <NUM> in an unfolded configuration. <FIG> show the clip <NUM> in a folded configuration. In an embodiment, the clip <NUM> can be formed as a single monolithic piece. For example, the safety mechanism can be stamped from a sheet of metal, polymer, plastic, composite, or the like and shaped into the folded configuration (<FIG>). Optionally, a portion of the clip <NUM> can be heated to facilitate folding of the clip <NUM>. Advantageously, the clip <NUM>, formed as such, simplifies the manufacturing process and reduces associated costs and complexity. <FIG> shows a side view of the clip <NUM> in a folded configuration. <FIG> shows a plan view of the clip <NUM> in a folded configuration.

The clip <NUM> generally includes a first arm 410A and a second arm 410B and a biasing member <NUM> extending therebetween. In an embodiment, each arm <NUM> can include a tab <NUM> (e.g. a first tab 420A and a second tab 420B), a plate <NUM> (e.g. a first plate 430A and a second plate 430B), and a grip <NUM> (e.g. a first grip 440A and a second grip 440B). In an embodiment, the biasing member <NUM> can be a flat spring, a leaf spring, or the like, and can extend between the first plate 430A and the second plate 430B. In an embodiment, the biasing member <NUM> can extend between the first tab 420A and the second tab 420B.

As shown in <FIG>, each arm <NUM> can include a tab foldline <NUM>, disposed between the tab <NUM> and the plate <NUM>, and a grip foldline <NUM> disposed between the plate <NUM> and the grip <NUM>. In an embodiment, the tab foldline <NUM> or the grip foldline <NUM> can include a score line, groove, perforation, laser cut line or similar line of weakness to facilitate folding of the arm <NUM> therealong, as described in more detail herein.

In an embodiment, each tab <NUM> can define a tab length (LT) and a tab width (WT). Each plate <NUM> can define a plate length (LP) and a plate width (WP). Each grip <NUM> can define a grip length (LG) and a grip width (WG). In an embodiment, the tab length (LT) can be equal to, or greater than, the tab width (WT). In an embodiment, the tab length (LT) can be equal to, or greater than the plate length (LP). In an embodiment, the tab width (WT) can be equal to, or greater than the plate width (WP).

In an embodiment, the plate length (LP) can be equal to or greater than the plate width (WP). In an embodiment, the plate length (LP) can be equal to, or greater than the grip length (LG). In an embodiment, the grip length (LG) can be equal to, less than, or greater than the grip width (WG). In an embodiment, the grip width (WG) can be substantially equal to the plate width (WP). In an embodiment, the grip width (WG) can be greater than, or less than the plate width (WP).

In some embodiments, the tab length (LT) of the first tab 420A can be equal to the tab length (LT) of the second tab 420B. In some embodiments, the tab length (LT) of the first tab 420A can be different from the tab length (LT) of the second tab 420B. In some embodiments, the plate length (LP) of the first plate 430A can be equal to the plate length (LP) of the second plate 430B. In some embodiments, the plate length (LP) of the first plate 430A can be different from the plate length (LP) of the second plate 430B. In some embodiments, the grip length (LG) of the first grip 440A can be equal to the grip length (LG) of the second grip 440B. In some embodiments, the grip length (LG) of the first grip 440A can be different from the grip length (LG) of the second grip 440B.

In an embodiment, the tab <NUM> can further include a keyhole aperture <NUM> substantially defining a "keyhole" shape and defining a keyhole aperture length (LK). For example, the first tab 420A can include a first keyhole aperture 450A, and the second tab 420B can include a second keyhole aperture 450B. Each keyhole aperture <NUM> can include a lock aperture <NUM> communicating with an unlock aperture <NUM>. The lock aperture <NUM> can define a first inner diameter (d1), and the unlock aperture <NUM> can define a second inner diameter (d2), larger than the first diameter (d1). In an embodiment, the diameter (d2) of the unlock aperture <NUM> is equal to or greater than an outer diameter of the obturator <NUM>.

In an embodiment, the diameter (d1) of the lock aperture <NUM> is less than an outer diameter of the obturator <NUM>. In an embodiment, the diameter (d1) of the lock aperture <NUM> is equal to or greater than the diameter of the notch <NUM>. To note, the outer diameter (OD2) of the notch <NUM> is less than an outer diameter (OD1) of the obturator <NUM>. In an embodiment, the keyhole aperture length (LK) can be equal to or greater than the first diameter (d1) and the second diameter (d2) combined.

In an embodiment, the biasing member <NUM> can extend from the first arm 410A to the second arm 410B to define a biasing member length (LB), and can define a biasing member width (WB) extending perpendicular thereto. In an embodiment, the biasing member length (LG) is greater than the biasing member width (WB). In an embodiment, as shown in <FIG>, the biasing member length (LB) can extend through less than <NUM>° of the circumference of the sheath <NUM>, e.g. through an arc distance (x).

In an embodiment, the biasing member <NUM> can couple to the first arm 410A or the second arm 410B at any position therealong. In an embodiment, the biasing member <NUM> can couple to the first plate 430A or the second plate 430B at any position therealong. In an embodiment, an axis of the elongate biasing member <NUM> can extend perpendicular to an axis of the first arm 410A or the second arm 410B and can couple to the first arm 410A and the second arm 410B at a similar position therealong. In an embodiment, an axis of the elongate biasing member <NUM> can extend at an angle relative to an axis of the first plate arm 410A or the second arm 410B and can couple to the first arm 410A and the second arm 410B at different positions.

In an embodiment, the keyhole apertures <NUM> can be oriented on the respective tabs <NUM> in the same direction or in different directions. For example, the first keyhole aperture 450A can be oriented with the first unlock 460A aperture disposed closer to the first plate 430A and the second keyhole aperture 450B can be oriented with the second lock aperture 458B disposed closer to the second plate 430B. In other embodiments, the first keyhole aperture 450A can be oriented with the first lock aperture 458A disposed closer to the first plate 430A and the second keyhole aperture 450B can be oriented with the second unlock aperture 460B disposed closer to the second plate 430B. These and other orientations of keyhole apertures are considered to fall within the scope of the present disclosure.

<FIG> shows a side view of the clip <NUM> in the folded configuration. <FIG> shows a plan view of the clip <NUM> in the folded configuration. In an embodiment, to transition the clip <NUM> from the unfolded configuration (<FIG>) to the folded configuration (<FIG>), the first tab 420A can be folded, relative to the first plate 430A, along the first plate fold line 424A, through an angle of substantially <NUM>°. The second tab 420B can be folded, relative to the second plate 430B, along the second plate fold line 424B, through an angle of substantially <NUM>°. The first grip 440A can be folded, relative to the first plate 430A, along the first grip fold line 434A through an angle of substantially <NUM>°. The first grip 440A can extend substantially parallel to the first tab 420A. The second grip 420B can be folded, relative to the second plate 430B, along the second grip fold line 434B, through an angle of substantially <NUM>°. The second grip 440B can extend substantially parallel to the second tab 420B.

The elongate biasing member <NUM> can be elastically deformed such that a portion of first keyhole aperture 450A overlaps a portion of the second keyhole aperture 450B and aligns with a central longitudinal axis, substantially defined by obturator <NUM>. As such, in the folded configuration, the first tab 420A and the second tab 420B extend radially inward. Similarly, the first grip 440A and the second grip 440B extend radially inward, relative to a central longitudinal axis of the obturator <NUM>. The first plate 430A and the second plate 430B can extend substantially parallel to the central longitudinal axis.

In the folded configuration, in an embodiment, the first tab 420A can be positioned above the second tab 420B. In other embodiments, the second tab 420B can be positioned above the first tab 420A. In some embodiments, the elongated biasing member <NUM> can be elastically deformed to define an arcuate shape. The biasing member <NUM> can extend along a portion of the circumference of the sheath <NUM>. As shown in <FIG>, in an embodiment, the elongate biasing member <NUM>, in the elastically deformed configuration, extends through an arc distance (x) of between <NUM>° and <NUM>°. In an embodiment, the elongate biasing member <NUM> in the elastically deformed configuration extends through an arc distance of between <NUM>° and <NUM>°.

In an embodiment, the clip <NUM> may be formed by 3D printed, injection molded, or the like, in the folded configuration, or formed in the unfolded configuration and then folded to the folded configuration, as described herein. In an embodiment, the clip <NUM> can be formed from two or more pieces joined together by welding, bonding, adhesive, or the like in the folded configuration, or formed in the unfolded configuration and then folded to the folded configuration, as described herein.

<FIG> show an exemplary method of use for the clip <NUM>. <FIG> shows a plan view of the first tab 420A and the second tab 420B in the first, or unlocked, configuration. <FIG> shows a plan view of the first tab 420A and the second tab 420B in the second, or locked, configuration. <FIG> shows a side view of the obturator <NUM> and the first tab 420A and the second tab 420B in the first configuration. <FIG> shows a side view of the obturator <NUM> and the first tab 420A and the second tab 420B in the second configuration. To note, the biasing member <NUM> is not shown for clarity. Further, the first tab 420A is shown as ghosted to show the relative position of the second tab 420B disposed there below. The elastic properties of the elongate biasing member <NUM> biases the first tab 420A and the second tab 420B towards the second configuration (<FIG>).

In the first configuration, as shown in <FIG>, the first unlock aperture 460A aligns with the second unlock aperture 460B to define an opening sufficient to allow an outer diameter of the obturator <NUM> to pass therethrough. In some embodiments, the first configuration with the first unlock aperture 460A and the second unlock aperture 460B aligning is the natural higher energy state of the clip <NUM>. As illustrated in <FIG>, as the obturator <NUM> is withdrawn proximally from the needle <NUM>, the notch <NUM> of the obturator <NUM> longitudinally aligns with the first keyhole aperture 450A and the second keyhole aperture 450B. Since the outer diameter (OD2) of the notch <NUM> is less than the diameter (d1) of the lock aperture <NUM>, the notch <NUM> allows the biasing member <NUM> to transition the clip <NUM> from the first configuration to the second configuration. In the second configuration, the first tab 420A and the second tab 420B are displaced radially outward relative to a central longitudinal axis.

In some embodiments, the second configuration with the first lock aperture 458A and the second lock aperture 458B aligning with the central longitudinal axis, is the natural lower energy state of the clip <NUM>. To note, as shown in <FIG>, the first tab 420A, with the first grip 440A coupled thereto, and the second tab 420B, with the second grip 440B coupled thereto, are disposed radially outward in the second configuration, relative to the first configuration.

Advantageously, the clip <NUM> in the second configuration mitigates failure of the safety mechanism <NUM>. The biasing member <NUM> urges the first tab 420A and the second tab 420B to engage the notch <NUM> and prevent vertical movement of the obturator <NUM> relative to the clip <NUM>. As such, to transition the clip <NUM> from the second configuration to the first configuration and allow relative vertical movement of the obturator <NUM>, the notch <NUM> must be longitudinally aligned with the keyhole apertures 450A. The first arm 410A and the second arm 410B must be urged radially inward, perpendicular to the longitudinal axis, and with sufficient force to overcome the force of the biasing member <NUM>. The first unlock aperture 460A and the second unlock aperture 460B must be displaced radially inward and aligned with the central longitudinal axis. Advantageously, applying an axial force alone cannot cause the clip <NUM> to accidentally transition from the second configuration to the first configuration, causing accidental disengagement of the sheath <NUM> from the tip of the obturator <NUM>.

With continued reference to <FIG>, the safety mechanism <NUM>, including the clip <NUM> and the sheath <NUM> can selectively engage the needle hub <NUM>. <FIG> shows the safety mechanism <NUM> in the first configuration, whereby the obturator <NUM> is slidably engaged with the clip <NUM>. <FIG> shows the clip <NUM> in the second configuration whereby the sheath <NUM> is in a fixed longitudinal position relative to a distal tip of the obturator <NUM>. With the safety mechanism <NUM> in the second configuration, a distal edge <NUM> of the sheath <NUM> extends distally of the distal tip 104A of the obturator <NUM> to mitigate accidental stick injuries.

The needle hub <NUM> can support the needle <NUM> defining a needle lumen <NUM>. The needle hub <NUM> can define a hub recess <NUM> communicating with the needle lumen <NUM>. The sheath <NUM> can include a body <NUM>, defining a sheath lumen <NUM>, and a shroud <NUM> extending axially therefrom. A portion of the sheath body <NUM> can be configured to extend into the needle hub recess <NUM> and can engage an inner surface thereof. In an embodiment, the sheath <NUM>, or portion thereof (e.g. the body <NUM> or the shroud <NUM>), can engage the needle hub <NUM> in an interference fit, snap-fit engagement, luer lock engagement, threaded engagement, combinations thereof, or the like.

The sheath lumen <NUM> can be configured to receive the obturator <NUM> extending therethrough. The sheath <NUM> can further include a shroud <NUM> extending axially. The sheath <NUM> can extend over an outer surface of the needle hub <NUM> when the sheath body <NUM> is engaged with the needle hub recess <NUM>. In an embodiment, an inner surface of the shroud <NUM> can slidably engage an outer surface of the needle hub <NUM>. In an embodiment, the sheath shroud <NUM> can include one or more sheath apertures <NUM>, e.g. a first aperture 502A and a second aperture 502B, extending through the shroud <NUM>, perpendicular to the longitudinal axis. In some embodiments, the one or more apertures <NUM> can communicate with a channel (not shown) extending annularly around the outer circumference of the sheath shroud <NUM>.

In the first configuration (<FIG>), the first arm 410A and the second arm 410B are disposed radially inward relative to each other and the obturator <NUM> can slide longitudinally relative to the safety mechanism <NUM>. The grip <NUM> of the arm <NUM> can extend through the aperture <NUM> and engage an outer surface of the needle hub <NUM>. In an embodiment, the grip <NUM> can engage a grip recess <NUM> disposed in an outer surface of the needle hub <NUM>. For example, as shown in <FIG> with the sheath <NUM> engaged with the needle hub <NUM>, a first grip 440A can extend through the first sheath aperture 502A and engage a first grip recess 504A. A second grip 440B can extend through the second sheath aperture 502B and engage a second grip recess 504B. As such, the clip <NUM> can secure the sheath <NUM> to the needle hub <NUM> and can prevent disengagement therefrom when an axial force is applied.

Advantageously, the sheer strength of the grips <NUM> mitigates premature disengagement of the safety mechanism <NUM> from the needle hub <NUM> as the obturator <NUM> is withdrawn proximally. Worded differently, the sheer forces of the grip <NUM> interacting with the grip recess <NUM> are greater than the frictional forces of the keyhole apertures <NUM> interacting with the obturator <NUM>. As such, the grip <NUM> prevents the sheath <NUM> from disengaging the needle hub <NUM>.

As shown in <FIG>, as the obturator <NUM> is withdrawn proximally, the notch <NUM> longitudinally aligns with the keyhole apertures 450A, 450B. The smaller outer diameter of the notch <NUM> can allow the clip <NUM> to transition from the first configuration to the second configuration. In the second configuration the first arm 410A and the second arm 410B can be displaced radially outward relative to each other. As such the grips 440A, 440B are also displaced radially outward and disengage grip recesses 504A, 504B of the needle hub <NUM>. As such, the sheath <NUM> can disengage the needle hub <NUM>. In an embodiment, the length (LG) of the grips 440A, 440B, are sufficient to allow the grips 440A, 440B to remain engaged with the sheath apertures 502A, 502B respectively, so that the clip <NUM> remains engaged with the sheath <NUM> in both the first configuration and the second configuration. The obturator <NUM>, with the safety mechanism <NUM> engaged there can be removed. As noted, the distal tip <NUM> of the sheath <NUM> in the second configuration extends distally of the distal tip 104A of the obturator <NUM> to prevent accidental needle stick injuries.

Advantageously, embodiments of the safety mechanism <NUM>, as described herein, provide a simplified manufacturing process and reduce associated costs. The clip <NUM> can be stamped from a single sheet of material and folded into position. The sheath <NUM> and needle hub <NUM> can be molded in a single process that negates any secondary machining.

<FIG> show an embodiment of a clip <NUM> including a single tab <NUM> configured to be used with the sheath <NUM> of the safety mechanism <NUM>. <FIG> shows a plan view of the clip <NUM> in the first configuration. <FIG> shows a plan view of the clip <NUM> in the second configuration. The clip <NUM> can include an arm <NUM> and a biasing member <NUM> coupled thereto. In an embodiment, the arm <NUM> can include a tab <NUM>, a plate <NUM> and a grip <NUM>. The tab <NUM> includes a keyhole aperture <NUM> defining a keyhole aperture length (LK) and having a lock aperture <NUM> communicating with an unlock aperture <NUM>.

In an embodiment, the biasing member <NUM> extending annularly about the sheath <NUM>. For example, the biasing member <NUM> can be coupled to the plate <NUM> and extend through <NUM>° around the entire outer circumference of the sheath <NUM>. In an embodiment, the biasing member <NUM> can extend through less than <NUM>° e.g. around at least half of the outer circumference of the sheath <NUM>. In an embodiment, a portion of the biasing member <NUM>, e.g. a portion disposed opposite the plate <NUM> can be coupled with sheath <NUM>. In an embodiment, the elongate biasing member <NUM> can elastically deform between a first configuration (<FIG>), and a second configuration (<FIG>). The biasing member <NUM> biases the clip <NUM> towards a second configuration (<FIG>). In the first configuration, the grip <NUM> can engage a sheath aperture <NUM> and a grip recess <NUM> to engage the sheath <NUM> with the needle hub <NUM>, as described herein. In the second configuration, the tab <NUM> engages the notch <NUM> of the obturator <NUM> to lock the sheath <NUM> relative to the obturator tip 104A, the radially outward movement of the plate <NUM> disengages the grip <NUM> from the grip recess <NUM> allowing the safety mechanism <NUM> to disengage the needle hub <NUM>, as described herein.

Claim 1:
A safety mechanism, comprising:
an elongate medical device (<NUM>, <NUM>) having a shaft extending along a longitudinal axis and defining a first outer diameter (OD1), the shaft including a notch (<NUM>) extending annularly and defining a second outer diameter (OD2), less than the first outer diameter (OD1);
a sheath (<NUM>) including a body (<NUM>) defining a sheath lumen (<NUM>) configured to receive the elongate medical device (<NUM>, <NUM>) therethrough, and a shroud (<NUM>) extending axially and including a first sheath aperture (502A) and a second sheath aperture (502B); and
a clip (<NUM>) configured to transition between a first configuration and a second configuration, the clip (<NUM>) comprising:
a first arm (410A), including a first tab (420A), a first plate (430A), and a first grip (440A), the first tab (420A) including a first keyhole aperture (450A);
a second arm (410B), including a second tab (420B), a second plate (430B), and a second grip (440B), the second tab (420B) including a second keyhole aperture (450B); and
a biasing member (<NUM>) extending from the first arm (410A) to the second arm (410B) and configured to bias the clip (<NUM>) towards the second configuration, the elongate medical device (<NUM>, <NUM>) extending through the first keyhole aperture (450A) and the second keyhole aperture (450B), the first grip (440A) extending through the first sheath aperture (502A), and the second grip (440B) extending through the second sheath aperture (502B).