Patent Description:
This application also claims priority to and the benefit of <CIT>.

The present disclosure relates generally to systems, apparatus, and methods for deploying a medical instrument into a body lumen of a subject during a medical procedure, and in particular, to a cutting device capable of forming an incision for receiving a medical instrument, such as a catheter, into a body lumen of a subject.

Intravascular medical devices such as catheters are deployed in many medical procedures. Use of intravascular catheters, however, can lead to bloodstream infections, which can be costly to treat and/or result in death or other health complications. For example, an infection can result from skin organisms that migrate from an insertion site of a catheter onto and along an external surface of the catheter. This migration of skin organisms along the catheter which dwell within a central vessel, artery, or vein, can lead to a blood stream infection. In many hospitals in the U. including high performing intensive care units, this type of event occurs approximately <NUM>-<NUM> times every <NUM> central line days, and sometimes far more. Infections can also be tied to use of other types of catheters placed for other reasons to provide medical care, including catheters such as dialysis catheters, cannulation catheters for extracorporeal membrane oxygenation (ECMO), and chest tubes placed within the pleural cavity.

A catheter or other intravascular medical device can be delivered into blood vessels, organs, body cavities, and other anatomic sites ("target site(s)" or "target anatomical site(s)") using a variety of techniques. One commonly used technique to gain access to a target site (e.g., a blood vessel) is the Seldinger technique. The Seldinger technique involves penetrating through skin tissue overlying a blood vessel of a subject with a sharp hollow object, typically a hollow needle. A wire (e.g., a guidewire) can then be advanced via a lumen of the needle into the blood vessel, and the needle can be withdrawn over the guidewire and removed.

Following placement of the wire but prior to insertion of the catheter or other intravascular device, an incision (e.g., "skin-nick," in cases where the diameter of the catheter is small) in the skin tissue is formed through the skin at or adjacent to the opening formed by the needle (i.e., the entry site for the wire). If formed properly, the incision will start at the opening or puncture site of the needle, and have a length approximately equal to the diameter of the catheter to be subsequently inserted. After the incision is formed, the catheter or other medical instrument can then be passed over the wire, through the incision, and into the blood vessel or body cavity.

While techniques such as the Seldinger technique can be used to deploy a catheter or other medical instrument into a target site, such as a blood vessel, they can be difficult and/or time-consuming to perform properly. For example, complications can occur with the creation of the incision, e.g., where the incision does not initiate at the opening of the puncture site resulting in a skin-bridge, the incision is too large, or the incision is too long. When these complications arise, it may be impossible (or additional measures may be required) to insert the dilator or catheter (or other medical instrument(s)) over the Seldinger wire into the target vessel, such as in the case of a skin bridge). Alternatively, if an incision is too large, bleeding may occur around the catheter, which can be substantial, or the incision itself, being open, can provide a site for colonization, either of which increases the risk of bacterial colonization at the catheter entry site, increasing the risk of a blood stream infection. Accordingly, it is desirable to have systems and methods that reduces the difficulty and/or skill required to gain access to a target site, thereby reducing complications associated with use of any invasive catheter.

In <CIT>, a tissue cutter includes a housing, a blade, a pivot, and a blade spring. The housing is shaped so as to define a channel that has proximal and distal openings and a central longitudinal axis, and is shaped for slidable disposition therein of a hollow tubular element having a tapered distal portion. The blade which extends alongside the central longitudinal axis, and defines a sharp cutting surface that reaches a distal-most point of the blade and faces away from the central longitudinal axis. The pivot couples the blade to the housing such that the blade is rotatable with respect to the housing around a pivot point of the blade. The blade spring is arranged to apply a force to the blade that pushes a distal portion of the blade against the tapered distal portion of the hollow tubular element when the blade is positioned alongside the tapered distal portion.

<CIT> discloses a surgical instrument having a cylindrical tube affixed thereto. A guidewire can be threaded through the cylindrical tube to allow for advancement of the surgical instrument to a surgical site.

<CIT> relates to a scalpel guide system for any bladed surgical instrument. A pair of wire guides attach to a scalpel, for controlled travel of the scalpel along the wire. The wire guides of the scalpel guiding system are especially useful as an enhancement to the "Seldinger technique," a common surgical procedure employed for the percutaneous placement of elongated, tubular devices, with the aid of a guidewire or a wire. The scalpel can be any knife-like surgical device, conventionally including a blade attached to a handle. The scalpel guiding system preferably includes a pair of wire guides, each extending from the blade of the scalpel, or alternatively the handle of the scalpel. The scalpel can be disposable, as can the blade, independent of the scalpel. The wire can be any guidewire or filament, as conventionally employed in surgical techniques that involve the insertion of such a wire or strand. The wire is engageable by the scalpel mounted pair of wire guides. This engagement allows the user or surgeon to move the scalpel along the wire in a controlled and guided manner, for precise cutting or incising, as required for the needed procedure or operation.

The invention provides an apparatus according to claim <NUM>. Further embodiments of the invention are provided in the dependent claims.

According to an aspect of the present disclosure, an apparatus for forming a controlled incision in tissue is provided. The apparatus may include a coupling mechanism (e.g., a reversible coupling mechanism) configured to couple the apparatus to a dilator having a tapered distal end and a hub at a proximal end. The dilator may define a lumen configured to receive a wire that extends or is otherwise extendable through a puncture site. The apparatus may further include a proximal end configured to abut the hub of the dilator when the apparatus is coupled to the dilator. The apparatus may further include a cutting element including an inner edge and an outer cutting edge. The cutting element may be configured to be movable between a retracted position and an extended position, in which the inner edge extends along the tapered distal end of the dilator. The outer cutting edge may be configured to form an incision extending from the puncture site, thereby preventing the formation of a skin bridge. Furthermore, the cutting element can be configured to form an incision that has a length that is equal to a diameter of a catheter (or other medical instrument) that is inserted into the incision.

According to an aspect of the present disclosure, a method for deploying a catheter or other medical instrument into a body lumen is provided. The method may include advancing a dilator, over a wire positioned through a puncture site formed in a tissue, toward the puncture site. The dilator may have a reversibly attached cutting device including a cutting element configured to cut the tissue. The method may further include moving the cutting element from a retracted position to an extended position. The method may further include inserting the distal end of the dilator and the cutting element into the tissue such that the cutting element forms an incision extending from the puncture site and sized to receive a surgical instrument.

According to an aspect of the present disclosure, a kit including a system for deploying a medical instrument is provided. The kit may include a dilator defining a lumen configured to receive a wire that extends or is otherwise extendable through a puncture site. The dilator may include a hub at a proximal end and a tapered distal end. The kit may further include a cutting device including a cutting element configured to form an incision extending from the puncture site. The cutting element may be configured to be movable between a retracted position and an extended position. The cutting device may be configured to be reversibly coupled to the dilator such that a portion of the cutting element extends to the distal end of the dilator when the cutting element is in the extended position.

Other systems, processes, and features will become apparent to those skilled in the art upon examination of the following drawings and detailed description.

The drawings are merely schematic representations, not intended to portray specific parameters of the invention. The drawings are intended to depict only typical embodiments of disclosed systems, apparatus, and methods. In the drawings, like reference characters refer to like elements (e.g., functionally similar and/or structurally similar elements).

Embodiments of the present disclosure are directed to systems, apparatus, and methods for providing access to a target site (e.g., a blood vessel) such that a medical instrument, e.g., a catheter, can be deployed in the target site. Specifically, systems, apparatus, and methods described herein can be used to form an incision in tissue of a subject during a vascular access procedure and/or other procedures involving placement of a medical device into a body cavity.

Vascular access procedures, such as, for example, the Seldinger technique, can be used to provide access to a target body lumen (e.g., vessel, pleural space) by deploying a medical instrument (e.g., a catheter) into the target body lumen. For example, when the Seldinger technique is used, a target body lumen (e.g., vessel, pleural space) may be accessed percutaneously by puncturing skin of the subject with a hollow needle, inserting a guidewire through the hollow needle so as to position the distal end of the guidewire in the target body lumen. The needle can be withdrawn, leaving the wire in place. To accommodate a placement of a catheter or other medical instrument, the diameter of the skin puncture site traversed by the wire can be enlarged or dilated. To accomplish this, the operator can create a skin incision extending from the puncture site and having a length equal to the diameter of the catheter or other medical instrument. Once that incision is formed, a dilator (or one or more increasingly larger dilators) is passed over the Seldinger wire, creating a track (e.g., opening) suitable to accommodate the final catheter or medical instrument to be inserted into the target body lumen.

The incision can be formed using a cutting device, such as, for example, a blade or scalpel, to form the incision. The physician can hold the guidewire using one hand, and the cutting device using his or her other hand, and then via visual guidance, create the incision, which can receive the dilator, catheter, and/or other medical instrument. If properly performed (e.g., if the incision is properly created or formed), the incision extends from the puncture site and has a length equal to but not longer than the diameter of the catheter or other instrument to be inserted through the incision. Complications, however, can arise when the incision is not properly formed. For example, when the incision is too long, it allows leakage of bodily fluids around the catheter when it is positioned, compromising the ability of the skin to function as a barrier to infection. For example, an incision too long compromises the ability of the skin to form a biological seal around the catheter, which would normally prevent migration of bacteria or other disease-causing agents into the target body lumen. Furthermore, an oversized incision allows blood to leak out around the catheter skin entry site, which can be substantial, particularly in situations where a subject has received an anticoagulant. In these cases, the incision may require stitches to better approximate the skin against the catheter so as to prevent bleeding.

As another example, if the incision does not involve the entry site made by the needle (i.e., in which the Seldinger wire sits), but leaves a skin bridge between the incision and the initial entry site created by the needle, the ensuing dilator and/or other medical instrument can be prevented from being passed along the wire and through the entry site. <FIG> schematically illustrates cases where a skin bridge can form. As depicted, skin bridges <NUM>, <NUM> can form when an incision <NUM>, <NUM> does not overlap with an opening of the puncture site <NUM>. For example, a skin bridge <NUM> can form when an incision <NUM> does not initiate at the puncture site <NUM>, even if that incision is aligned with the puncture site <NUM>. And a skin bridge <NUM> can form when an incision <NUM> is offset from the puncture site <NUM> (e.g., not aligned with the puncture site <NUM>). These skin bridges <NUM>, <NUM> can prevent a dilator or other instrument from being inserted into the skin. In practice, a physician may move a guidewire after forming the incision <NUM> to determine whether there is a skin bridge <NUM>, <NUM>, e.g., by visibly inspecting whether the guidewire appears to be moving along a length of the incision. But with skin having some elasticity and with poor visibility surrounding the puncture site (e.g., caused by blood pooling around the puncture site and incision), it may not be possible to determine whether a skin bridge has formed even if it appears the guidewire is moving along the incision. If a physician fails to identify that there is a skin bridge <NUM>, <NUM> and pushes a dilator or other instrument down along the guidewire (e.g., forces a dilator or other instrument down on the guidewire), the physician can bend or damage the guidewire. Then, even if the physician were to detect the skin bridge <NUM>, <NUM> and cut it away, e.g., with a second incision, the bent guidewire can prevent the dilator or other instrument from being inserted into the skin. The second incision combined with the first incision <NUM>, <NUM> can also lead to an incision size that is not sized to that of the dilator or other instrument, which as detailed above, can lead to migration of bacteria. Therefore, when complications arise with a skin bridge, the physician may have no other option than to remove the guidewire and restart the procedure. Systems, devices, and methods described herein are designed to prevent the formation of a skin bridge, i.e., by ensuring that an incision extends from a puncture site, as depicted in <FIG> with incision <NUM>' extending from puncture site <NUM>. Further details of such systems, devices, and methods are provided below.

Similarly, if the incisional length is too short, the dilator and/or other medical instrument can be prevented from passing deeper than the level of the skin. In particular, if the incision does not extend from the puncture site, a skin-bridge can result. The skin bridge can prevent the catheter from being properly inserted into the target body lumen (i.e., because the skin bridge separates the puncture site from the incision), leading to bending of the Seldinger wire, and preventing its use as the dilator may not be able to pass over the bent wire, even after the skin bridge has been, by necessity, incised. And if the incision is too long, this can prevent the skin or tissue surrounding the opening from sealing around the catheter or instrument, which can enable disease-causing agents (e.g., microorganisms, bacteria, viruses) to migrate along an external surface of the catheter into the target body lumen.

In the situations described above, if the problem is initially unrecognized, forcing the dilator can bend the wire or damage the dilator and/or other medical instrument, which can require the deployment procedure to be repeated. Repeating the deployment procedure can involve repeated accessing of the vessel or body cavity, with its inherent dangers and patient discomfort, and/or the need of a new wire and/or insertion kit.

Systems, apparatus, and methods described herein can reduce the risk of complications resulting from placement of a catheter or other instrument into a body lumen. As further described below, a cutting device can be designed to consistently form a controlled incision in skin that addresses the aforementioned problems, allowing for placement of the desired catheter or instrument into a body lumen without complications.

As illustrated schematically in <FIG>, an example cutting device <NUM> can include a housing <NUM>, a cutting element <NUM>, and a coupling mechanism <NUM>. The example cutting device <NUM> can be placed proximate to a skin <NUM> of a subject and used to form an incision in the skin <NUM>, e.g., by moving the cutting element <NUM> through the skin <NUM>. The housing <NUM> can support the cutting element <NUM> and optionally include an actuation assembly or mechanism <NUM> designed to actuate the cutting element <NUM> to form the desired incision in the skin <NUM>.

In some embodiments, the housing <NUM> can define a volume, recess, or area for housing the cutting element <NUM> in a retracted or undeployed position such that a cutting surface of the cutting element <NUM> is shielded when the cutting element is not in use. The actuation assembly <NUM> can be designed to move the cutting element <NUM> forward, e.g., as schematically depicted using arrow <NUM>, to position the cutting element <NUM> in an extended or deployed position, such that the cutting element <NUM> can form an incision in the skin <NUM>. The actuation assembly <NUM> can include one or more actuation mechanisms for deploying the cutting element <NUM>, i.e., for moving the cutting element <NUM> from an undeployed position into a deployed position, as well as allowing for differential incision lengths. In some embodiments, the actuation assembly <NUM> can include mechanical components for deploying the cutting element <NUM>. For example, the actuation mechanism <NUM> can include a trigger that can be actuated to release a pre-loaded spring or other elastic component that can generate a force to deploy the cutting element <NUM>. In some embodiments, the actuation assembly <NUM> can include a movable component or actuator (e.g., a slider, button, tab, lever) that can be moved (e.g., slid along a length of the housing <NUM>) to deploy the cutting element <NUM>. In some embodiments, the actuation mechanism <NUM> can include electrically powered components (e.g., components driven and/or powered by a battery or other power source) for deploying the cutting element <NUM>. In some embodiments, the actuation assembly <NUM> can include components driven mechanically, electrically, magnetically, pneumatically, hydraulically, etc..

The cutting element <NUM> can include one or more cutting surfaces or blades that are designed to penetrate through the skin <NUM> to form an incision. Alternatively or additionally, the cutting element <NUM> can include other mechanisms, e.g., a drill, an electrode, etc., for cutting through the skin <NUM>. The cutting element <NUM> can be coupled to (e.g., mounted to) housing <NUM> in a fixed or movable relation, e.g., allowing for a variable length incision. Furthermore, in some embodiments, the cutting element <NUM> can be movably coupled to housing <NUM> such that it can move between an undeployed position and a deployed position, e.g., as represented by arrow <NUM>. In some embodiments, the cutting element <NUM> can be removably coupled to housing <NUM>. For example, the cutting element <NUM> can be designed to be removed or detached from housing <NUM>, such that the cutting element <NUM> can be replaced after a single or limited number of uses. In some embodiments, the cutting element <NUM> and/or housing <NUM> can be disposable components that can be disposed of after a single use, e.g., after being used to provide access to a target site in the subject.

The housing <NUM> can be ergonomically shaped such that a user (e.g., a physician) can hold (e.g., grip) the housing <NUM> in single hand. Optionally, if the actuation assembly <NUM> is present, the actuation assembly <NUM> can be positioned on or about the housing <NUM> such that the user can actuate the actuation assembly <NUM> while maintaining his hold (e.g., grip) on the housing <NUM> with a single hand. For example, the actuation assembly <NUM> can be a slide that can be moved, e.g., using a thumb of a user, to actuate the cutting element <NUM> during a medical procedure. The housing <NUM> and cutting element <NUM> can be formed from lightweight material such that a user can comfortably hold the housing <NUM> and cutting element <NUM> without feeling additional strain during a medical procedure.

The cutting device <NUM> can include a depth control element <NUM> that is integrated into and/or coupled to the housing <NUM> and/or cutting element <NUM>. The depth control element <NUM> can be designed to limit a depth of penetration or insertion of the cutting element <NUM> into the skin <NUM> so as to control a size of the incision formed by the cutting element <NUM> in the skin <NUM>. In some embodiments, the depth control element <NUM> can be designed to contact a surface of the skin <NUM> to control a depth of insertion of the cutting element <NUM>. For example, the depth control element <NUM> can include a surface, protrusion, or other physical structure that can be disposed at a point along the cutting element <NUM> and/or housing <NUM> such that it would contact a surface of the skin <NUM> when the cutting element <NUM> has been inserted a predetermined depth into the skin <NUM>. In some embodiments, the depth control element <NUM> can include one or more components that restrict movement of the cutting element <NUM>, thereby controlling a depth of insertion of the cutting element <NUM>. For example, the depth control element <NUM> can include one or more protrusions and/or surfaces that interfere (e.g., lock) with one another to prevent further movement of the cutting element <NUM> in a direction toward the skin <NUM> after the cutting element <NUM> has penetrated a predetermined depth into the skin. In some embodiments, the depth control element <NUM> can include one or more sensor(s) (e.g., a light sensor, a pressure sensor, etc.) that can be designed to sense or detect a depth of insertion.

The coupling mechanism <NUM> can include one or more components designed to couple the housing <NUM> (or other components of the cutting device <NUM>) to an instrument (e.g., a dilator, a catheter, etc.). In some embodiments, the coupling mechanism <NUM> can be designed to reversibly couple the housing <NUM> to the instrument. For example, the coupling mechanism <NUM> can be designed to couple and decouple the housing <NUM> to the instrument and/or additional instruments, as many times as needed without comprising its structure. In some embodiments, the coupling mechanism <NUM> can include mechanical components, e.g., a clasp, a clip, etc. that can attach around the instrument to couple the housing <NUM> to the instrument. The mechanical component can be designed to be flexible such that it can bend to fit around (e.g., grip onto) the instrument. Alternatively or additionally, the mechanical component can be designed to be mechanically biased (e.g., with a spring) or electrically driven to change between different configurations for attaching to and/or detaching from the instrument. The coupling mechanism <NUM> can be configured to maintain the coupling between the housing <NUM> and the instrument by interference fit, press fit, friction fit, and the like. In some embodiments, the coupling mechanism <NUM> can be configured to allow coaxial movement of the instrument such that the housing <NUM> (and other components of the cutting device <NUM>) can slide or move along a length of the instrument. The coupling mechanism <NUM> can be integrated into or attached to the housing <NUM>. As further described with reference to <FIG>, the coupling mechanism <NUM> can be configured to attach the housing <NUM> (or other components of the cutting device <NUM>) to the instrument such that the cutting element <NUM> is positioned to create an incision in the skin <NUM> for receiving the desired instrument. In some embodiments, the coupling mechanism <NUM> can be sized to a specific size of instrument. Alternatively, the coupling mechanism <NUM> can be configured to couple to instruments within a range of sizes, e.g., such as with adjustable components (e.g., an adjustable clamp or a deformable plug that accommodates a range of sizes).

In some embodiments, a positioning element <NUM> can optionally be used with the cutting device <NUM> to assist with proper positioning of the device along a length of the instrument. For example, the positioning element <NUM> can be designed to couple (e.g., attach) to the instrument, e.g., via a coupling element (e.g., coupling element <NUM>), and extend along a length of the instrument to indicate the location at which the cutting device <NUM> should attach to the instrument. When used with the cutting device <NUM>, the positioning element <NUM> can prevent the cutting device <NUM> from being attached to the instrument at a position that does not enable the cutting instrument to form a properly sized incision in the tissue <NUM>. In some embodiments, the positioning element <NUM> can be a spacer configured to extend from a proximal end or portion of the instrument to the location at which the cutting device <NUM> is designed to attach to the instrument, as further described with reference to <FIG>.

The coupling mechanism <NUM> can be structurally and/or functionally similar to the coupling mechanism <NUM>, but is designed to couple the positioning element <NUM> to the instrument, as represented by line <NUM>. For example, the coupling mechanism <NUM> can include a mechanical component (e.g., a clip or clasp) that is designed to reversibly couple (e.g., couple and decouple multiple times) the positioning element <NUM> to the instrument such as by interference fit, press fit, friction fit, and the like. The coupling mechanism <NUM> can be integrated into or attached to the positioning element <NUM> so as to enable and facilitate reversible coupling of the positioning element <NUM> to the instrument, such as described herein. The positioning element <NUM> and the housing <NUM> can be separately and individually attachable to and removable from the instrument.

In some embodiments, as an alternative to having a separate positioning element (e.g., positioning element <NUM>), the cutting device <NUM> can include a component (e.g., a protrusion) that can assist with positioning the cutting device <NUM> along a length of the instrument. For example, the cutting device <NUM> can include a beam, rod, or other like structure that can be configured to extend from a proximal end of the housing <NUM> to a proximal end or portion of the instrument, such that when the cutting device <NUM> is attached to the instrument (e.g., via the coupling mechanism <NUM>), such structure indicates the location at which the cutting device <NUM> should be positioned relative to the proximal or distal end of the instrument.

The positioning of a cutting device relative to an instrument can be further understood with reference to <FIG>. As illustrated schematically in <FIG>, an example cutting device <NUM> is shown in relation to an example instrument <NUM> (e.g., a surgical instrument) with which the cutting device <NUM> can be used. The cutting device <NUM> can be structurally and/or functionally similar to the cutting device <NUM>. For example, the cutting device <NUM> can include a housing <NUM>, a cutting element <NUM>, and a coupling mechanism <NUM>. The instrument <NUM> can include a hub <NUM> and a body <NUM>. The cutting device <NUM> can be reversibly attachable to and/or supportable by the instrument <NUM>, e.g., via the coupling mechanism <NUM> attaching to the body <NUM> of the instrument <NUM>, as represented by line <NUM>. The body <NUM> of the instrument <NUM> can include portions that are rigid and/or flexible.

In some embodiments, the cutting device <NUM> can optionally include or be used with a positioning element <NUM>. In some embodiments, positioning element <NUM> can be a spacer that is configured to define the appropriate spacing between a proximal portion (e.g., hub <NUM>) of the instrument <NUM> and a proximal end of the housing <NUM> supporting the cutting element <NUM>. For example, the positioning element <NUM> can be configured to couple to the body <NUM> of the instrument <NUM>, e.g., via coupling mechanism <NUM>, such that it extends from the hub <NUM> of the instrument <NUM> to a point along a length of the body <NUM> of the instrument <NUM> at which the housing <NUM> is intended to attach to the body <NUM>. When the housing <NUM> is attached to the body <NUM> of the instrument <NUM>, a proximal end of the housing <NUM> can be adjacent to a distal end of the positioning element <NUM> such that the positioning element <NUM> extends longitudinally along a length of the body <NUM> between the hub <NUM> and the housing <NUM>. The positioning element <NUM>, by extending between the hub <NUM> and the housing <NUM>, can be configured to prevent proximal movement of the housing <NUM> relative to the instrument <NUM>. Stated differently, the positioning element <NUM> can be designed to maintain the housing <NUM> in a fixed spatial relation with respect to the instrument <NUM>.

The cutting device <NUM> (and optionally positioning element <NUM>) can be used to form a skin incision in skin (e.g., skin <NUM>) for receiving the instrument <NUM>, e.g., such that the instrument <NUM> can be received into a target body lumen (e.g., a blood vessel). The instrument <NUM> can be, for example, a dilator, a catheter, a chest tube, or the like. In an embodiment, the instrument <NUM> can be a dilator that has a distal end configured to be inserted through the incision and a proximal end including a hub <NUM>. The dilator can have a tapered distal end that facilitates insertion into and subsequent dilation of tissue and/or blood vessels deep to the level of the skin incision (e.g., deeper than a level of the skin incision in skin <NUM>). In some embodiments, the dilator can range in size from about <NUM> French to about <NUM> French (i.e., about <NUM> to about <NUM>), including all values and subranges in between. The instrument <NUM> can include a lumen that extends throughout a length of the instrument <NUM>, i.e., through a length of the hub <NUM> and a length of the body <NUM>. The lumen can be configured to receive a guidewire, e.g., for steering or guiding the instrument <NUM> into the target body lumen.

In use, the cutting device <NUM> can be coupled to the instrument <NUM> such that the cutting element <NUM> can be configured to form an incision for receiving the instrument <NUM>, e.g., as part of the Seldinger technique. For example, a needle can be used to create a puncture site in tissue (e.g., tissue <NUM>), and a guidewire can be inserted through the needle into a body lumen (e.g., a blood vessel) deep to the insertion site at the skin level. The needle can be removed, and the instrument <NUM> (e.g., a dilator) with the housing <NUM> and optionally the positioning element <NUM> coupled to its body <NUM>, e.g., via coupling mechanisms <NUM> and/or <NUM>, can be slid over the guidewire until a distal end of the instrument <NUM> contacts a surface of the skin. The cutting element <NUM> can then be actuated to form an incision in the skin that extends from the puncture site and is sized to receive the instrument <NUM>. The housing <NUM> can be attached to the instrument <NUM> at a specific location that enables the cutting element <NUM>, when actuated, to form such an incision. The positioning element <NUM>, for example, can be used to set a spacing or distance between a proximal portion (e.g., hub <NUM>) of the instrument <NUM> and the housing <NUM>, to ensure proper positioning of the housing <NUM> relative to the instrument <NUM>. Once the incision is formed, the housing <NUM> and/or positioning element <NUM> can be removed (e.g., detached, decoupled) from the instrument <NUM>, and the instrument <NUM> can be inserted through the incision into the body (e.g., and into a lumen or cavity). If the instrument <NUM> is a dilator (or dilators), the dilator (or dilators) can be used to dilate the tissue and/or blood vessels deep to the incision, and be subsequently withdrawn over the guidewire allowing the appropriately sized catheter (or other instrument) to be guided down the guidewire and placed in the body lumen.

In some embodiments, where the instrument <NUM> includes a tapered distal end, e.g., such as a dilator with a tapered distal end, the cutting element <NUM> can be supported such that it is angled toward the puncture site (e.g., angled to follow the taper of the instrument <NUM>), such that the cutting element <NUM> can form an incision that extends from the puncture site, e.g., preventing any possibility of leaving a skin bridge.

Referring now to <FIG>, a method <NUM> of performing a medical procedure on a subject using a cutting device, such as any of those described herein (e.g., cutting device <NUM>, <NUM>, <NUM>, <NUM>, and/or <NUM>), is shown and described.

The method <NUM> can be a method of forming an incision for receiving an instrument (e.g., instrument <NUM>). The instrument can be, for example, a dilator. The method <NUM> can include forming, e.g., using a needle, a puncture site in tissue (e.g., skin <NUM>), and advancing a guidewire through the needle into a body lumen, at <NUM>. The needle can be removed, leaving the guidewire positioned traversing the puncture site. The instrument can define a lumen configured to receive the guidewire. The method <NUM> can optionally include coupling a cutting device to the instrument, at <NUM>. In some embodiments, a positioning element (e.g., positioning element <NUM>, <NUM> such as a spacer) can also be coupled to the instrument to assist with appropriate positioning of the cutting device on the instrument and to prevent proximal movement of the cutting device relative to the instrument. In some embodiments, each of the cutting device and/or the positioning element can be reversibly coupled to the instrument such that each can be removed (e.g., detached, decoupled) from the instrument, e.g., when moved in a direction lateral to the longitudinal axis (e.g., a central longitudinal axis) of the dilator. In some embodiments, the method <NUM> may not include coupling the cutting device to the instrument because the instrument may be provided (e.g., packaged, sold, etc.) with the cutting device pre-attached, to, but removable or detachable from, the instrument.

At <NUM>, the method <NUM> can include advancing the instrument over and along the guidewire toward the puncture site, e.g., until a distal end of the instrument is against a surface of the tissue. At <NUM>, the method <NUM> optionally includes actuating (e.g., via actuating assembly <NUM>) a cutting element (e.g., <NUM>, <NUM>) of the cutting device, e.g., to move the cutting element from a retracted position to an extended position. In some embodiments, the cutting element can be angled (e.g., to follow a tapered end of the instrument, such as the tapered end of a dilator), and therefore, actuation of the cutting element can cause the cutting element to extend radially inward towards a central longitudinal axis of the instrument. As described above with reference to <FIG>, actuation of the cutting element can include release of a compressed spring, such that the spring transitions from a compressed state to an uncompressed state to move the cutting element into the extended position. Alternatively, actuation of the cutting element can include moving (e.g., sliding) an actuation element that deploys the cutting element. For example, the cutting element can be moved from the retracted position to the extended position by moving a slider of the cutting device in a distal direction, e.g., using a thumb of a user when the slider is disposed on a side of the cutting device accessible by the thumb. When the cutting element has been actuated (e.g., deployed), the cutting element can be configured to form an incision in the tissue. In some embodiments, the method <NUM> may not include actuating the cutting element, e.g., because the cutting element is supported on the cutting device in an exposed manner and does not need to be actuated. In such embodiments, the cutting device may include a cap or other component that may shield the cutting element during transport but be removed from the cutting element prior to use of the cutting device.

The cutting element, when actuated, can form an incision in the tissue, at <NUM>. In some embodiments, the cutting device and the dilator can be advanced toward the tissue after the cutting element has been extended to form the incision. The incision can be formed such that it extends from the puncture site and is sized to receive the instrument. The incision, for example, can be formed to have a length that is substantially equal to the diameter of the instrument. In some embodiments, the cutting device includes a depth control element (e.g., depth control element <NUM>), which can control a distance that the cutting element can extend beyond a distal end of the cutting device and/or a distance that the cutting element can be inserted into the tissue, thereby controlling a depth of the incision. For example, a surface of the cutting device (e.g., a surface of a housing of the cutting device) can be configured to contact the tissue once the cutting element has been inserted a set distance into the tissue. Alternatively or additionally, one or more components of the cutting device may lock to prevent further extension of the cutting element beyond a distal end of the cutting device. In some embodiments, the cutting element can be movable, after forming the incision, from its extended position back to its retracted position.

At <NUM>, the method <NUM> optionally includes removing (e.g., decoupling, detaching) the cutting device and/or positioning element from the instrument, e.g., by moving the cutting device and/or positioning element in a direction lateral to the longitudinal axis of a body (e.g., body <NUM>) of the instrument.

At <NUM>, the method <NUM> optionally includes, after forming the incision, advancing the instrument over the guidewire into the incision. In some embodiments, the instrument is advanced until a distal end of the instrument is disposed within the body lumen. In some embodiments, when the instrument is a dilator, the instrument can be removed from the incision, and subsequent, larger instruments can be used to further dilate the subdermal tract to a final dilatation that allows a final catheter to be slid over the guidewire into the body lumen. The catheter can then provide access to the body lumen, e.g., via a lumen of the catheter.

In an example embodiment, a method can include disposing a dilator over a wire that has been inserted into a puncture site formed in tissue, the dilator including a proximal hub and an elongate body, the elongate body of the dilator having a cutting device reversibly coupled thereto; advancing the dilator with the cutting device toward the puncture site; moving a cutting element of the cutting device from (<NUM>) a fully retracted position in which the cutting element is disposed within a housing of the cutting device to (<NUM>) a fully extended position in which a distal portion of the cutting element extends distally from the housing to a distal end of the dilator; inserting the distal end of the dilator and the cutting element into the tissue such that the cutting element forms an incision extending from the puncture site; and moving the cutting device laterally away from a longitudinal axis of the dilator while maintaining the dilator over the wire to decouple the cutting device from the elongate body of the dilator. The distal end of the dilator and the cutting element can be inserted into the tissue until a distal surface of the housing contacts the tissue and prevents further insertion of the cutting element into the tissue so that the incision has a length that is approximately equal to a diameter of a catheter to be placed through the incision. The cutting element can be moved from the fully retracted position to the fully extended position after the distal end of the dilator is positioned against the puncture site, or the cutting element can be moved from the fully retracted position to the fully extended position while the dilator with the cutting device is advanced toward the puncture site. The cutting element can be disposed radially outward from a lumen of the dilator in the fully retracted and fully extended positions when the cutting device is coupled to the elongate body of the dilator. The cutting element can be moved from the fully retracted position to the fully extended position in response to moving an actuation mechanism of the cutting device in a distal direction, the actuation mechanism disposed on a side of the cutting device opposite from a side of the cutting device coupled to the dilator. The method can also include moving, after forming the incision, the cutting element from the fully extended position back to the fully retracted position, the cutting device being decoupled from the dilator after the cutting element is moved back to the fully retracted position. The method can also include advancing the dilator after decoupling the cutting device from the dilator to dilate the incision; removing the dilator from over the wire; and advancing the catheter over the wire and into the incision. The method can also include moving, after forming the incision, a spacer laterally away from the longitudinal axis of the dilator while maintaining the dilator over the wire to decouple the spacer from the elongate body of the dilator. The spacer can be reversibly coupled to the elongate body of the dilator and be configured to prevent proximal movement of the cutting device relative to the dilator.

Referring now to <FIG>, a schematic diagram depicting components of a surgical system is shown and described. The components depicted in <FIG> can be provided in a kit <NUM>, which can be provided to a physician for use during a surgical procedure. The kit <NUM> can be provided in packaging <NUM>, such as, for example, a box, a bag, etc. The packaging <NUM> can be configured to keep the components of the surgical system sterile prior to use. The surgical system can include an instrument <NUM> and a cutting device <NUM>, and optionally, a positioning element <NUM> and/or additional instrument(s) <NUM>.

The cutting device <NUM> can be functionally and/or structurally similar to other cutting device described herein (e.g., cutting device <NUM>, <NUM>). For example, in some embodiments, the cutting device can include a cutting element (e.g. cutting element <NUM>, <NUM>) configured to form an incision in tissue.

When included together in packaging <NUM>, the cutting device <NUM> can be pre-coupled to the instrument <NUM> at a desired location, e.g., allowing the creation of an incision in tissue. For example, the cutting device <NUM> can be coupled to the instrument such that a cutting element (e.g., cutting element <NUM>, <NUM>) of cutting device <NUM> can be configured to form an incision for receiving the instrument <NUM>, e.g., an incision that extends from a puncture site and is sized for receiving the instrument <NUM>. Alternatively, the cutting device <NUM> and the instrument <NUM> can be separately placed within the packaging <NUM>, e.g., within separate inner compartments and/or containers.

One or more components of kit <NUM> can be configured to be disposed after a single use. For example, the cutting device <NUM> can be configured for one-time use, e.g., the cutting device <NUM> can include one or more components that lock after a single use.

The instrument <NUM> can be a dilator, a catheter, a chest tube, or other surgical instrument. The instrument <NUM>, similar to instrument <NUM> described above, can define a lumen configured to receive a wire such as a guidewire that extends or is otherwise extendable through a puncture site. In some embodiments, the kit <NUM> can optionally include an appropriately sized guidewire (not shown) for use with the instrument <NUM>. The instrument <NUM> can include a hub (e.g., similar to hub <NUM>) at a proximal end and body (e.g., similar to body <NUM>). The incision formed by the cutting device <NUM> can be sized to receive the instrument <NUM>. For example, the incision can have a length that is substantially equal to a diameter of the instrument <NUM>. In some embodiments, the kit <NUM> can include the instrument <NUM> having a first diameter, and additional instruments <NUM> having diameters different than the first diameter. For example, the instrument <NUM> can be a dilator with a first dimeter, and an additional instrument <NUM> can be a dilator having a diameter greater than the first diameter of the dilator. In such embodiments, the kit <NUM> can contain a set of dilators that progressively increase in size, e.g., a progressive set of dilators. The dilators can increase in size from (<NUM>) a first diameter of the dilator that is configured to couple to the cutting device <NUM> to (<NUM>) a second diameter equivalent to a diameter of the final instrument (e.g., catheter) to be inserted into the incision and into a target vessel. Each of the dilators can be used to dilate the incision to the size of the surgical instrument. In these instances, the cutting device can create an incisional length equal to the diameter of the final dilator/catheter/tube to be inserted.

In some embodiments, the kit <NUM> can include the positioning element <NUM>, which can be a spacer configured to assist with positioning the cutting device <NUM> relative to the instrument <NUM>. Similar to positioning elements <NUM>, <NUM>, as described above, positioning element <NUM> can extend longitudinally along a length of the instrument <NUM> between a proximal portion (e.g., hub) of the instrument <NUM> to where the cutting device <NUM> couples to the instrument <NUM>, thereby setting a location of the cutting device <NUM> relative to the proximal portion of the instrument <NUM> and preventing proximal movement of the cutting device <NUM> relative to the instrument <NUM>. When included together in kit <NUM>, the positioning element <NUM> can be pre-coupled to the instrument <NUM> along with the cutting device <NUM> such that the instrument <NUM> and the cutting device <NUM> are ready for use. Alternatively, the positioning element <NUM>, cutting device <NUM> and instrument <NUM> can be included separately in kit <NUM> (e.g., in separate compartments or packages), such that a physician prior to and/or during a surgical operation must attach the positioning element <NUM> and the cutting device <NUM> to the instrument <NUM>, permitting the cutting device <NUM> to form an incision in tissue during the operation.

Referring now to <FIG>, various views of an example cutting device <NUM> are shown and described. The cutting device <NUM> can include components that are structurally and/or functionally similar to other cutting devices described herein, e.g., cutting devices <NUM> and <NUM>. For example, the cutting device <NUM> can include a housing <NUM>, an actuation assembly <NUM>, a cutting element <NUM>, a coupling mechanism <NUM>, a depth control element implemented as a tissue contact surface <NUM>, a positioning element <NUM>, and a coupling mechanism <NUM>. The cutting device <NUM> can be used with a medical device or instrument <NUM>, as depicted in <FIG> and <FIG>. The medical device <NUM>, similar to other medical devices described herein (e.g., medical device <NUM>), can include a hub <NUM> and a body <NUM>. The medical device <NUM> can be implemented as a dilator that includes a tapered distal end 554a. As shown in <FIG>, the medical device <NUM> can define a lumen <NUM> configured to receive a wire that extends or is otherwise extendable through a puncture site.

As shown in <FIG>, the cutting device <NUM> can be reversibly coupled to the medical device <NUM> via the coupling mechanism <NUM>, similar to that described with respect to the reversible coupling between the cutting device <NUM> and the instrument <NUM> via the coupling mechanism <NUM>. Further, the cutting device <NUM> can be designed such that, in a deployed position, a base (e.g., bottom edge <NUM> depicted in <FIG> and <FIG>) of the cutting element <NUM> extends along a distal end of the instrument <NUM> in contact with an outer surface of the instrument <NUM>, and in particular, extends radially inwardly towards a central longitudinal axis of the instrument <NUM>, e.g., at an angle θ as shown in <FIG>. The angle θ can be equal to or greater than an angle of the tapered distal end 554a of the instrument <NUM>, with respect to the longitudinal axis of the instrument <NUM>. In some embodiments, when the cutting element <NUM> is extended, a distal end of the cutting element <NUM> can terminate at (or substantially near) a distal end of the instrument <NUM>. The size of the incision formed by the cutting element can be dependent on an angle α of an outer cutting edge <NUM> of the cutting element <NUM> and a length that the cutting element <NUM> extends from a distal surface <NUM> of the cutting device <NUM>, as further described below.

The housing <NUM> can include multiple housing components that are held together via one or more fasteners, e.g., screws <NUM>, and/or adhesive. The housing <NUM> can define a volume, recess, or area for housing the cutting element <NUM> in a retracted or undeployed position, such as shown in <FIG>. For example, the cutting element <NUM> can be retracted for shielding such as behind a distal surface <NUM> of the cutting device <NUM>. As shown in <FIG>, the housing <NUM> can be ergonomically shaped to enable a user (e.g., a physician) that is operating the device to hold the housing <NUM> in a single handle and to actuate the actuation mechanism <NUM> to deploy the cutting element <NUM>, i.e., the move the cutting element <NUM> from its undeployed positon (depicted in <FIG>) to its deployed position (depicted in <FIG>). In some embodiments, different configuration(s) of the housing <NUM> can be suited for use by right- and left- handed users.

The cutting element <NUM> can include an inner edge <NUM> and an outer cutting edge <NUM>, and can be designed to be movable via the actuation assembly <NUM> between a retracted position, such as shown in <FIG>, and an extended position, such as shown in <FIG>. The cutting element <NUM> can include a locking mechanisms (e.g., a lock as described with reference to <FIG>, and internal surfaces as further described below) that prevents the cutting element <NUM> from extending beyond the retracted position (e.g., further into the housing <NUM>) or the extended position (e.g., further distal to the housing <NUM>). As such, the retracted position is a fully retracted position and the extended position is a fully extended position. In the retracted position, the cutting element <NUM> can be fully disposed within the housing <NUM>. In the extended position, a distal end of the cutting element <NUM> can terminate at (or substantially near) the distal end of the instrument <NUM>. In some embodiments, a portion of the inner edge <NUM> can extend substantially along the tapered distal end of the instrument <NUM> in contact with an outer surface of the instrument <NUM>. The cutting element <NUM> can be moved from the retracted position to the extended position and vice-versa. For example, such as shown in <FIG>, the cutting element <NUM> can be moved to the extended position by actuation of the actuation assembly <NUM>, implemented as a sliding component <NUM>. The sliding component <NUM> can be moved distally along a length of the cutting device <NUM> to move the cutting element <NUM> into the extended position. In all positions ranging from the retracted position to the extended position, the inner edge <NUM> of the cutting element <NUM> and a distal end of the cutting element <NUM> are disposed radially outward from the lumen of the instrument <NUM>. Stated differently, the cutting element <NUM> is configured to extend along the instrument <NUM> in contact with its outer surface but to not extend radially inward of an outer surface of the instrument <NUM>. The cutting element <NUM> can therefore form an incision that extends radially outward from a puncture site or a wire disposed in the lumen of the instrument <NUM>.

As depicted, the sliding component <NUM> can be attached (e.g., via a knob or protrusion 505a) to an elastic component such as a spring 504a that is expandable to accommodate the movement of the sliding component <NUM> and the cutting element <NUM> in the distal direction (e.g., to move the cutting element <NUM> into its extended position). When expanded, the spring 504a can exert a force upon the sliding component <NUM>, such that when sliding component <NUM> is released, the spring 504a can automatically revert to its resting position and retract the cutting element <NUM> back into its retracted position in the housing <NUM>.

The actuation assembly <NUM> can be designed to actuate the cutting element <NUM> from a retracted position to a deployed (e.g., extended) position to form an incision in and through skin (e.g., skin <NUM>). For example, the actuation assembly <NUM> implemented as the sliding component can include an interface element 504b (e.g., a protrusion) designed to interface with (e.g., engage with) an interface element 510a (e.g., a recess) of the cutting element <NUM>, to thereby actuate and move the cutting element <NUM> longitudinally along the housing <NUM>.

As described, the outer cutting edge <NUM> can be configured to cut tissue to form an incision. In some embodiments, the inner edge <NUM> in addition to the outer cutting edge <NUM> can be configured to cut tissue to form the incision. Since a distal end of the inner edge <NUM> extends along a distal end of the instrument <NUM> (e.g., a tapered end of a dilator), i.e., is immediately adjacent or next to the distal end of the instrument <NUM>, having both the inner edge <NUM> and outer edge <NUM> be configured to cut tissue can further reduce the risk of leaving a skin bridge.

In some embodiments, the cutting device <NUM> may not include a spring, such as spring 504a. In such embodiment, the user (e.g., physician) can manually retract the cutting element <NUM> back into the housing <NUM> after forming the incision by moving the sliding component <NUM> back in a proximal direction. While the cutting device <NUM> is depicted with an actuation assembly including a sliding component <NUM>, it can be appreciated that any number or type of actuation mechanisms can be used, e.g., including a button, tab, lever, and the like, which can be actuated by a user to deploy the cutting element <NUM>, such as described above with reference to cutting device <NUM>. For example, the actuation assembly <NUM> can alternatively include a trigger that can be actuated to release a pre-loaded or compressed spring or other elastic component that can generate a force to deploy and/or retract the cutting element <NUM>. In some embodiments, the actuation assembly <NUM> can alternatively include hydraulic or pneumatic mechanisms for deploying and/or retracting the cutting element <NUM>.

The depth control element can be designed to limit a depth of insertion or deployment of the cutting element <NUM>. In an embodiment, the depth control element can be implemented as a distal surface <NUM> of the cutting device <NUM>. The distal surface <NUM> of the cutting device <NUM> can be configured to contact a tissue surface and prevent further insertion of the cutting element <NUM> into the tissue. In particular, the cutting device <NUM> mounted on the instrument <NUM> and with the cutting element <NUM> extended can be slid down a length of a guidewire until the distal surface <NUM> contacts the tissue surface and prevents further insertion of the cutting element <NUM> into the tissue. The size of the incision can be controlled by a distance that the outer cutting edge <NUM> extends from the distal end <NUM> of the cutting device <NUM> and an angle α that the outer cutting edge <NUM> is angled with respect to the longitudinal axis of the instrument <NUM>. In other embodiments, the depth control element can be implemented as a surface that interacts with a surface of at least one of the cutting element <NUM> and/or the sliding component <NUM> of the actuation assembly <NUM> to control distal movement of the cutting element <NUM>. For example, the depth control element can be an internal surface of the housing <NUM> that engages a surface of the sliding component <NUM> once the sliding component <NUM> has extended the cutting element <NUM> a set distance from its retracted position. Alternatively, the depth control element can include a stopper designed to interface with a surface of the cutting element <NUM> by abutment to control translation and a depth of insertion of the cutting element <NUM>. In some embodiments, the depth control element can be integrated into and/or coupled to the housing <NUM> and/or cutting element <NUM>.

The coupling mechanism <NUM> can include one or more fasteners or couplings designed to reversibly couple the housing <NUM> to the instrument <NUM>, such as that shown in <FIG>. For example, the coupling mechanism <NUM> can include a flexible component such as a clip or clasp that is designed to reversibly couple the housing <NUM> of the cutting device <NUM> to the instrument <NUM> such as by gripping around the body <NUM> of the instrument. The coupling mechanism <NUM> can be configured to couple to the instrument <NUM> from a lateral direction, i.e., by moving the housing <NUM> in a direction toward the longitudinal axis of the instrument <NUM>, and similarly to decouple from the instrument <NUM> in a lateral direction. The coupling mechanism <NUM> can be integrated into or otherwise used in conjunction with the housing <NUM> in any suitable manner so as to enable and facilitate reversible coupling of the housing <NUM> to the instrument <NUM>, such as described herein. Once coupled to the instrument <NUM>, the coupling mechanism <NUM> can generate sufficient friction against a surface of the body <NUM> of the instrument <NUM> to prevent movement (e.g., sliding and/or rotation) of the cutting device <NUM> relative to the instrument <NUM>. As depicted in <FIG> and <FIG>, the coupling mechanism <NUM> can include multiple attachment points to reduce the risk of movement due to a torsional force. In some embodiments, the coupling mechanism <NUM> can be configured to couple the housing <NUM> to a specific size of instrument, e.g., a dilator having a specific diameter and length. In other embodiments, the coupling mechanism <NUM> can be adjustable (e.g., via tightening and/or loosening of a screw or other adjustment mechanism, or due to a malleability of the coupling mechanism) to adapt the coupling mechanism <NUM> for use with different sized instruments.

The positioning element <NUM> can be used with the cutting device <NUM> to maintain the housing <NUM> in a fixed spatial relation with respect to the medical device <NUM>. For example, the positioning element <NUM> can be implemented as a spacer having a handling tab <NUM> to facilitate coupling (e.g., by a user) of the positioning element <NUM> with the instrument <NUM>, e.g., via coupling mechanism <NUM>. The spacer can be placed such that it extends from the hub <NUM> (e.g., is adjacent to the hub <NUM>) to a proximal end of the housing <NUM>, thereby defining a set spacing between the hub <NUM> and the housing <NUM>, as shown in <FIG>. The spacer can be configured for use with a specific size of the instrument <NUM>, e.g., a dilator having a specific diameter and length.

The coupling mechanism <NUM> can be designed to reversibly couple the positioning element <NUM> to the instrument <NUM>. For example, the coupling mechanism <NUM> can include a flexible component such as a clip or clasp that is designed to removably couple the positioning element <NUM> to the instrument <NUM> such as by interference fit, press fit, friction fit, and the like (e.g., by gripping around the body <NUM> of the instrument <NUM>. The coupling mechanism <NUM> can be integrated into or otherwise used in conjunction with the positioning element <NUM> so as to enable and facilitate reversible coupling of the positioning element <NUM> to the instrument <NUM>, such as described herein. The positioning element <NUM> and the housing <NUM> can be separately and individually attachable to and removable from the instrument <NUM>.

In use, cutting device <NUM> including the housing <NUM> and the positioning element <NUM> can be coupled (e.g., attached) to the body <NUM> of the instrument <NUM>. The instrument <NUM> can be slid down a length of a guidewire that is positioned in a puncture site, e.g., a puncture site formed as part of a surgical procedure using the Seldinger technique. The instrument <NUM> can be slid down the guidewire until a distal end of the instrument <NUM> is positioned adjacent to the skin with the puncture site. The cutting element <NUM> can be positioned in a retracted position (as shown in <FIG>) while the instrument <NUM> is slid down a length of the guidewire. Once the instrument <NUM> is in position against the skin, the cutting device <NUM> can then be actuated, e.g., by sliding the sliding component <NUM> toward the puncture site to form an incision with the cutting element <NUM> that extends from the puncture site and is sized to receive the instrument <NUM>. Optionally, the cutting element <NUM> can be retracted back into the housing <NUM>, and the housing <NUM> and/or the positioning element <NUM> can be removed (e.g., decoupled, detached) from the instrument <NUM> and set aside. The instrument <NUM> can then be inserted into the incision, e.g., to dilate the tissue below the incision and/or be placed within a body lumen to provide vascular access to the body lumen.

Referring now to <FIG>, views of another example cutting device <NUM> are shown and described. <FIG> depicts a side view of the cutting device <NUM> coupled to an instrument <NUM> (e.g., a dilator). <FIG> schematically illustrates a distal end of the cutting device <NUM> and the instrument <NUM>. And <FIG> schematically illustrates a cross-sectional view of a distal end portion of the cutting device <NUM> and the instrument <NUM>. The cutting device <NUM> can include components that are structurally and/or functionally similar to other cutting devices described herein. For example, the cutting device <NUM> can include a housing <NUM>, a cutting element <NUM>, and a coupling mechanism <NUM>. The cutting device <NUM> can be used with the instrument <NUM>, similar to other instruments described herein.

As depicted in <FIG>, the instrument <NUM> can be implemented as a dilator having a body <NUM> that includes a tapered distal end 1254a, and a hub <NUM> at a proximal end. The instrument <NUM> can define a lumen configured to receive a wire such as guidewire <NUM> that extends or is otherwise extendable through a puncture site. In addition, the instrument <NUM> can include a slot or opening <NUM> that extends along a distal portion of the instrument <NUM> for receiving the cutting element <NUM> therethrough, as further described below.

The cutting device <NUM> can be configured to reversibly couple to the instrument <NUM> and can include a proximal end configured to abut the hub <NUM> of the instrument <NUM> when coupled thereto, as described herein. In some embodiments, the cutting device <NUM> may be designed to move or slide longitudinally along a body <NUM> of the medical device <NUM>.

The housing <NUM> can support the cutting element <NUM>. For example, the housing <NUM> can include a clamp, protuberance, knob, bump, or other attachment mechanism for holding and supporting the cutting element <NUM>. The cutting element <NUM> can include an inner edge (not depicted) and an outer cutting edge <NUM>. In some embodiments, the inner edge in addition to the outer cutting edge <NUM> can be a cutting edge configured to cut tissue. The cutting element <NUM> can be translated along the instrument <NUM> by translation of the housing <NUM> along the instrument <NUM>, such that the inner edge moves along a length of the slot <NUM> in the instrument <NUM>. The cutting element <NUM> can be translated distally along a length of the instrument <NUM> such that it extends into tissue. In some embodiments, the housing <NUM> can be designed to be slid or translated along the instrument <NUM> by manually applied force (e.g., via a hand of a user).

As depicted in <FIG>, the slot <NUM> enables a portion of the cutting element <NUM> (e.g., an inner edge of the cutting element <NUM>) to extend into an inner lumen of the instrument <NUM> such that the cutting element <NUM> abuts or is near the wire <NUM>. The cutting element <NUM> can then be slid along the slot <NUM> in a distal direction to form an incision that extends from a puncture site in which the wire <NUM> is disposed. By enabling the cutting element <NUM> to extend into the inner lumen of the instrument <NUM> to the wire <NUM>, the slot <NUM> prevents the formation of a skin bridge. As depicted in <FIG>, the slot <NUM> can have a width that is sufficiently large to permit the cutting element <NUM> to extend into the inner lumen of the instrument <NUM> but less than a diameter of the wire <NUM> such that the wire <NUM> cannot exit from the inner lumen of the instrument <NUM> via the slot <NUM>.

In some embodiments, the cutting device <NUM> can include a depth control element <NUM> that is designed to limit a depth of insertion or deployment of the cutting element <NUM>. For example, the depth control element <NUM> can include a surface of a protrusion (e.g., a protuberance, knob, bump, etc.) designed to contact the skin of a subject to limit further insertion of the cutting element <NUM> into the skin. The depth control element <NUM> can be integrated into and/or coupled to the housing <NUM>. Alternatively, the depth control element <NUM> can be integrated into and/or coupled to the cutting element <NUM>.

The coupling mechanism <NUM> can reversibly couple the housing <NUM> to the instrument. For example, the coupling mechanism <NUM> can include a flexible component such as a clip or clasp that is designed to removably couple the housing <NUM> to the instrument <NUM> such as by interference fit, press fit, friction fit, and the like. The coupling mechanism <NUM> can be integrated into or otherwise used in conjunction with the housing <NUM> so as to enable and facilitate reversible coupling of the cutting device <NUM> to the instrument <NUM>, such as described herein. In some embodiments, for example, the coupling mechanism <NUM> can include two attachment points to prevent movement of the cutting device <NUM> with respect to the instrument <NUM> due to torsional forces.

A proximal portion of the cutting device <NUM> can function as a positioning element, e.g., be designed to maintain the housing <NUM> in a fixed spatial relation with respect to the instrument <NUM>. For example the proximal portion of the housing <NUM> can extend to the hub <NUM> of the instrument <NUM> to define a spacing between the hub <NUM> and the cutting element <NUM> and to thereby ensure specific positioning of the cutting device relative to a proximal end of the instrument <NUM>.

Referring now to <FIG>, various views of another example cutting device <NUM> are shown and described. The cutting device <NUM> can be implemented as an instrument (e.g., a dilator) that includes one or more cutting elements <NUM>. The cutting device <NUM> can include components that are structurally and/or functionally similar to other cutting devices described herein (e.g., cutting device <NUM>, <NUM>, etc.). For example, the cutting device <NUM> can include a housing <NUM>, a cutting element <NUM>, and a depth control element <NUM>. Similar to other dilators described herein, the cutting device <NUM> can include a proximal hub <NUM> and an elongate body (e.g., housing <NUM>) that defines a lumen <NUM> for receiving a guidewire that extends or is otherwise extendable through a puncture site.

The cutting device <NUM> is designed to receive a guidewire (e.g., wire <NUM>) within the lumen <NUM> of the device and to slide along a length of the guidewire. The housing <NUM> at its distal end can support one or more cutting element(s) <NUM>. Each of the cutting element(s) <NUM> can include an outer cutting edge. The outer cutting edge can be configured to form an incision in tissue, where the incision extends from a puncture site in which the guidewire is disposed. The outer cutting edges can be configured to form a continuous incision that is symmetrically disposed about a puncture site. As depicted in <FIG>, the cutting element(s) <NUM> are configured as flat blades.

The cutting device <NUM> can include a depth control element <NUM> that is designed to control a depth of insertion of the cutting element(s) <NUM>. For example, the depth control element can include a stopper (e.g., a protuberance, knob, bump, etc.) designed to contact a surface (e.g., skin or tissue of a subject) to limit further insertion of the cutting element(s) <NUM> into the tissue. The depth control element <NUM> can be integrated into and/or coupled to the housing <NUM> and/or cutting element(s) <NUM>.

<FIG> depicts the cutting device <NUM> being used to form an incision in skin. After a wire <NUM> has been positioned in a puncture site formed in the skin, the cutting device <NUM> can be slid down along a length of the wire <NUM> until the depth control element <NUM> of the cutting device <NUM> contacts a surface of the skin (as depicted in <FIG>). The cutting element <NUM> of the cutting device <NUM> can form an incision in the skin that is sized according to a position of the depth control element <NUM> relative to a distal end of the cutting device <NUM>. As the cutting elements <NUM> are adjacent to the lumen <NUM> of the cutting device <NUM> at its distal end, the cutting elements <NUM> form an incision that extends from the puncture site without a skin bridge.

Referring now to <FIG>, various views of an example cutting device <NUM> are shown and described. The cutting device <NUM> can include components that are structurally and/or functionally similar to any of the other cutting devices described herein, e.g., cutting devices <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. For example, the cutting device <NUM> can include a housing <NUM>, an actuation assembly <NUM>, a cutting element <NUM>, a coupling mechanism (not depicted), a depth control element (not depicted), and/or a positioning element (not depicted). The cutting device <NUM> can be used with a medical device or instrument (not depicted), such as a dilator, a catheter, or any others described herein.

The cutting element <NUM> can include a single or multiple edges that are formed as cutting edges, which can be configured to cut tissue to form an incision. For example, in an embodiment, both an inner and outer edge of the cutting element <NUM> can be cutting edges. Having both inner and outer edges be formed as cutting edges can reduce a risk of leaving a skin bridge. The actuation assembly <NUM> can include a guide 1604B and a follower 1604A. The follower 1604A can be configured to be attached to or fixed, mated, or coupled, with the cutting element <NUM> in any suitable manner. The actuation assembly <NUM> can also include an actuator (e.g., a slider, button, tab, lever, not depicted) that can be moved (e.g., slid along a length of the housing <NUM>) such as by a user. In some embodiments, the guide 1604B and the follower 1604A can be configured to transform movement of the actuator (e.g., caused by an applied force, e.g., by a user) into a combination of linear and lateral motion of the cutting element <NUM>. In some embodiments, the guide 1604B can be a cam, such as in the form of a surface, slot, channel, or depression defined in the housing <NUM>. In some embodiments, the guide 1604B can include and/or define one or more of a straight path or section and a curved path or section. In some embodiments, the follower 1604A can be a cam follower such as in the form of a roller, bearing, or the like, shaped and designed to move along and follow a path (e.g., slot, channel, depression) defined by the guide 1604B. The follower 1604A, when moving along the guide 1604B, is confined to motion limited by the path defined by guide 1604B. Stated differently, a cam (e.g., guide 1604B) and cam follower (e.g., follower 1604A) can be used to provide a combination of linear movement and lateral movement of a cutting element <NUM>.

As depicted in <FIG>, movement 1619A of the actuator of the actuation assembly <NUM> can be transferred and applied to the follower 1604A, to which the cutting element <NUM> is attached. The movement 1619A can be a linear movement or motion corresponding to the motion of the actuator. As depicted in <FIG>, continued movement 1619B of the actuator can be transferred and applied to the follower 1604A. The continued movement 1619B can be a linear movement or motion corresponding to the motion of the actuator. The guide 1604B in conjunction with the follower 1604A can transform the linear motion of the actuator into a combination of linear and lateral motion of the cutting element <NUM>.

As depicted in <FIG>, the movement 1619A of the actuator is transferred and applied to the follower 1604A to cause a motion of the cutting element <NUM>. The continued movement 1619B of the movable component is similarly transferred and applied to the follower 1604A such that, upon traversal of and movement past a predetermined point (e.g., coinciding with a transition from a straight section to a curved section of the guide 1604B), the follower 1604A along with the cutting element <NUM> are subjected to lateral motion 1619C. <FIG> depicts an example motion of the follower 1604A and the cutting element <NUM>. The lateral motion 1619C can include, for example, a hacking or swinging motion.

More specifically, movements 1619A and 1619B of the actuator (of the actuation assembly <NUM>) cause movement of the follower 1604A along the guide 1604B, such that the movement along a curved section of the guide 1604B causes the lateral motion 1619C of the cutting element <NUM>. While the follower 1604A is in the straight section of the guide 1604B, the follower 1604A and cutting element <NUM> can move (e.g., slide) in a straight path. When the follower reaches the curved section of the guide 1604B, the follower 1604A and cutting element <NUM> can begin to move laterally or radially as the follower 1604A continues to move along the guide 1604B. As shown in <FIG>, to cause the motion of the follower 1604A, including both the straight and curved movement, the actuator can move in a straight path.

<FIG> depict an example cutting device <NUM>. The cutting device <NUM> can include components that are structurally and/or functionally similar to other cutting devices described herein, e.g., cutting device <NUM>, <NUM>, and <NUM>. For example, the cutting device <NUM> can include a housing <NUM>, an actuation mechanism <NUM>, a cutting element <NUM>, a coupling mechanism <NUM>, and a depth control element implemented as a tissue contact surface <NUM>. While not depicted, cutting device <NUM> can be used with a positioning element but can also be used alone.

The cutting device <NUM> is reversibly coupleable to a medical device, e.g., a dilator <NUM> as shown in <FIG>, via the coupling mechanism <NUM>. The coupling mechanism <NUM> includes two fastening or coupling points 1806a, 1806b. At each coupling point 1806a, 1806b, one or more plugs or gripping mechanisms 1807a, 1807b (which can be rigid or flexible) can be used to reversibly couple to the dilator <NUM>. Alternatively or additionally, other types of coupling elements, e.g., clamps, clips, magnets, etc., can also be used to grip the dilator <NUM>. The coupling mechanism <NUM> can be configured to couple to the dilator <NUM> from a lateral direction, e.g., by moving the cutting device <NUM> in a direction toward the longitudinal axis of the dilator <NUM>, and similarly to decouple from the dilator <NUM> in a lateral direction. While not depicted in <FIG>, the dilator <NUM> can include a proximal end including a hub (e.g., as described with reference to instrument <NUM> depicted in <FIG>). Accordingly, the cutting device <NUM>, by being laterally coupleable and decoupleable from the dilator <NUM>, is capable of being separated from the dilator <NUM> even while the dilator <NUM> is disposed over a guidewire that is disposed within a patient. Once coupled to the dilator <NUM>, the coupling mechanism <NUM> can generate sufficient friction against the dilator <NUM> to prevent movement (e.g., sliding and/or rotation) of the cutting device <NUM> relative to the dilator <NUM>. The coupling mechanism <NUM> includes more than one coupling point (i.e., two coupling points 1806a, 1806b) such that the coupling points collectively prevent pivoting and/or displacement of the cutting device <NUM> relative to the dilator <NUM>. The dilator <NUM> itself may have a degree of flexibility, and therefore having multiple points of coupling can ensure that the dilator <NUM> remains aligned with the cutting device <NUM> during use.

In the embodiment depicted, the coupling point 1806a can be located at or near a distal or front end of the cutting device <NUM>, to further ensure alignment between a cutting element <NUM> of the cutting device and a longitudinal axis of the dilator (e.g., by reducing the risk of displacement between the end of the dilator <NUM> and the cutting device <NUM>). Such alignment ensures that the cutting device <NUM> does not form an incision that is offset from the puncture site, as depicted in <FIG>. In some embodiments, one or more components of the coupling mechanism <NUM> can be controlled, e.g., via a mechanical or electrical actuator, to open and/or close to couple and decouple the cutting device <NUM> to the dilator <NUM>. While two coupling points 1806a, 1806b are depicted in the figures, it can be appreciated that any number of coupling points or a continuous coupling point can be used to couple the cutting device <NUM> to a medical instruction such as dilator <NUM>.

The housing <NUM> can define a space of volume for receiving and housing a cutting element <NUM> of the cutting device <NUM>. The housing <NUM> can be ergonomically sized and shaped to enable a user (e.g., a physician) that is operating the device to hold the housing <NUM> in a single handle and to actuate the actuation mechanism <NUM> to deploy the cutting element <NUM>. In some embodiments, the housing <NUM> can include certain ridges or indentations <NUM>, as well as other like features, to facilitate gripping by a user. The housing <NUM> can support the actuation mechanism <NUM> in a location where it can be easily manipulated by a finger of a user (e.g., an index finger or thumb of a user). In some embodiments, the housing <NUM> can support the actuation mechanism <NUM> along a side of the cutting device <NUM> that faces away from the dilator <NUM> when the two are coupled together. For example, the housing <NUM> can support the actuation mechanism <NUM> on a side of the cutting device <NUM> that is opposite from the side including the coupling mechanism <NUM> or on a side of the cutting device <NUM> furthest away from the dilator <NUM> in a direction radial to the longitudinal axis of the dilator <NUM>. The actuation mechanism <NUM>, as disposed, can be capable of being operated by both left and right handed users. In alternative embodiments, the actuation mechanism <NUM> can be supported by the housing in other locations along its surface, e.g., such as the actuation mechanism <NUM> of the cutting device <NUM>.

The cutting element <NUM> is moveable between a first position, i.e., a fully retracted or undeployed position, and a second position, i.e., a fully extended or deployed position. Cross-sectional views of the retracted position are depicted in <FIG> and <FIG>, and views of the extended position are depicted in <FIG>, <FIG>, and <FIG>. In the retracted position, the cutting element <NUM> can be disposed entirely within the housing <NUM>, e.g., such that any cutting surfaces or edges of the cutting element <NUM> are shielded within the housing <NUM>. In the extended position, the cutting element <NUM> can extend out from a distal surface <NUM> of the cutting device <NUM>. The cutting element <NUM> can include an inner edge <NUM> and an outer edge <NUM>. In some embodiments, both the inner and outer edges <NUM>, <NUM> can be cutting edges, e.g., designed to cut tissue. In some embodiments, the outer edge <NUM> can be a cutting edge while the inner edge <NUM> can be a non-cutting edge. In some embodiments, one or both of the inner and outer edges <NUM>, <NUM> can include a non-cutting portion and a cutting portion.

The cutting element <NUM>, in the fully extended position, can have a portion of its inner edge <NUM> extend along or substantially along a distal end 1850a of the dilator <NUM> in contact with an outer surface of the distal end 1850a, as depicted in <FIG>. Similar to that described above with reference to cutting element <NUM> of cutting device <NUM>, the cutting element <NUM> can be angled such that its inner edge <NUM> extends along the outer surface of the distal end 1850a of the dilator <NUM>. In the fully extended position, the distal end 1810a of the cutting element <NUM> terminates at (or substantially near) the distal end of the dilator <NUM>. In some embodiments, the cutting device <NUM> can include a spring <NUM> (e.g., a torsion spring, an elastic spring, etc.) that applies a force upon the cutting element <NUM> that pushes the cutting element <NUM> against an outer surface of the dilator <NUM>. The force applied by the spring <NUM> can further ensure that the inner edge <NUM> of the cutting element <NUM> is disposed against the outer surface of the dilator <NUM>. The dilator <NUM> includes a lumen <NUM> for receiving a guidewire, e.g., such as a guidewire being used in a Seldinger procedure. When used in a Seldinger procedure, the dilator <NUM> can be slid down a length of the guidewire to a puncture site, and the cutting element <NUM> can be extended to form an incision. The cutting element <NUM>, by being disposed against an outer surface of the dilator <NUM> and with its distal end 1810a extending to the distal end of the dilator <NUM>, ensures that the incision formed by the cutting element <NUM> extends from the puncture site.

The size of the incision formed by the cutting element <NUM> can be sized to a particular medical instrument, e.g., the dilator <NUM>. The size of the incision can be controlled by a length that the cutting element <NUM> extends and an angle at which the outer cutting edge is angled relative to the longitudinal axis of the dilator <NUM>, as described in more detail above with respect to cutting element <NUM> of cutting device <NUM>. The cutting device <NUM> can include a depth control element implemented as a tissue contacting surface <NUM>. The surface <NUM> can be configured to contact the tissue surface near the puncture site to prevent further insertion of the cutting element <NUM> into the tissue. Therefore, in use, the cutting device <NUM> mounted on the dilator <NUM> can be slid down a length of the guidewire until the distal surface <NUM> contacts the tissue surface and prevents further insertion of the cutting element <NUM> into the tissue. The cutting element <NUM> can be extended prior to, during, or after sliding the cutting device <NUM> with the dilator <NUM> down along the length of the guidewire to form the incision.

The actuation mechanism <NUM> can be used to extend and retract the cutting element <NUM>. In some embodiments, the cutting device <NUM> can include a locking mechanism that locks or prevents movement of the actuation mechanism <NUM> until the actuation mechanism is depressed. The locking mechanism can prevent unintentional movement of the actuation mechanism <NUM> and therefore unintentional movement of the cutting element <NUM>. In some embodiments, the locking mechanism can include a track or guide <NUM>, a spring <NUM> (e.g., a torsion spring, elastic spring, etc.), and a plate or other structural component <NUM> that defines one or more openings 1844a, 1844b. The actuation mechanism <NUM> can include one or more protrusions or detents 1805a, 1805b. The spring <NUM> can be configured to apply a force against the actuation mechanism <NUM> that positions the detents 1805a, 1805b of the actuation mechanism <NUM> within the openings 1844a, 1844b of the plate <NUM>. The actuation mechanism <NUM> with the detents 1805a, 1805b so positioned is prevented from moving, e.g., by detents 1805a, 1805b coming into contact with opposing surfaces of the plate <NUM>.

In use, the actuation mechanism <NUM> can be depressed into the housing <NUM> (as shown by arrow <NUM>) such that the detents 1805a, 1805b move through the openings 1844a, 1844b and into the track <NUM>. For example, a user can apply sufficient force to overcome the force applied by the spring <NUM> to depress the actuation mechanism <NUM>. The actuation mechanism <NUM> can then be pushed forward (i.e., toward a distal surface <NUM> of the cutting device <NUM>) with the detents 1805a, 1805b travelling along the track <NUM>, thereby extending the cutting element <NUM>. The actuation mechanism <NUM>, without first being depressed downward into the housing <NUM>, is prevented from moving such that accidental taps against the actuation mechanism <NUM> do not cause unintentional extension of the cutting element <NUM>.

While various embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the inventive teachings is/are used. Embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure.

As used herein, the terms "about" and/or "approximately" when used in conjunction with values and/or ranges generally refer to those values and/or ranges near to a recited value and/or range. In some instances, the terms "about" and "approximately" may mean within ± <NUM>% of the recited value. For example, in some instances, "approximately a diameter of an instrument" may mean within ± <NUM>% of the length of the instrument. The terms "about" and "approximately" may be used interchangeably.

Claim 1:
An apparatus, comprising:
a cutting device (<NUM>) including:
a housing (<NUM>);
a set of couplers (<NUM>) configured to reversibly couple the cutting device to a dilator (<NUM>),
the dilator disposable about a wire that has been inserted into a puncture site formed in tissue;
a cutting element (<NUM>) configured to be in a fully retracted position in which the cutting element is disposed within the housing and a fully extended position in which a distal end of the cutting element extends distally from the housing, the cutting element configured to form an incision in the tissue that extends from the puncture site, the cutting element configured to be disposed radially outward from a lumen (<NUM>) of the dilator in the fully retracted and fully extended positions,
wherein the set of couplers is configured to decouple from the dilator when the dilator is disposed about the wire and the cutting device is moved in a direction lateral to a longitudinal axis of the dilator; and
an actuation mechanism (<NUM>) supported by the housing, the actuation mechanism including a moveable component (<NUM>) or actuator which is slidable along the housing to deploy the cutting element when the cutting device is coupled to the dilator and the dilator is disposed about the wire such that the cutting element can form the incision.