Medical grasping device

A medical grasping device is disclosed. The medical grasping device may be configured to retrieve an object from within a body lumen. A medical grasping device assembly, wherein a portion of the medical grasping device is disposed within a lumen of a delivery sheath, and methods of using the medical grasping device assembly are also disclosed.

TECHNICAL FIELD

The present disclosure relates generally to medical grasping devices. More specifically, the present disclosure relates to medical grasping devices configured for retrieval of objects from body lumens and methods of use.

DETAILED DESCRIPTION

The various embodiments disclosed herein generally relate to medical grasping devices. More specifically, the various embodiments relate to medical grasping device systems, for example, medical grasping device assemblies and related methods. In some embodiments, the medical grasping device assembly comprises an elongate member, a plurality of resilient prongs, and a delivery sheath. Also disclosed herein are methods of utilizing a medical grasping device assembly.

It will be appreciated that various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure. Many of these features may be used alone and/or in combination with one another.

Embodiments may be understood by reference to the drawings, wherein like parts are designated by like numerals throughout. It will be readily understood that the components of the present disclosure, as generally described and illustrated in the drawings herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the apparatus is not intended to limit the scope of the disclosure, but is merely representative of possible embodiments of the disclosure. In some cases, well-known structures, materials, or operations are not shown or described in detail. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

The phrases “connected to,” “coupled to,” and “in communication with” refer to any form of interaction between two or more entities, including but not limited to mechanical, electrical, magnetic, electromagnetic, fluid, and thermal interaction. Two components may be coupled to each other even though they are not in direct contact with each other. For example, two components may be coupled to each other through an intermediate component.

The terms “proximal” and “distal” refer to opposite ends of a medical device, including the devices disclosed herein. As used herein, the proximal portion of a medical device is the portion nearest a practitioner during use, while the distal portion is a portion at the opposite end. For example, the proximal end of a medical grasping device is defined as the end closest to the practitioner during insertion or utilization of the medical grasping device. The distal end is the end opposite the proximal end, along the longitudinal direction of the medical grasping device.

The terms “foreign body” and “foreign object” refer to any item, matter, or substance, such as a medical device or an embolism, which may be disposed or positioned within a body lumen. In some embodiments, the foreign body or object may be undesirable or unwanted. Specifically, a foreign body or object may be an item that a practitioner desires or targets to remove or retrieve from within a body lumen. For example, the foreign body or object may comprise a medical device (e.g., a vascular filter or a stent) that is disposed within a vessel, and a medical grasping device of the present disclosure may be configured to retrieve the medical device from within the vessel. Further, disclosure herein relating to displacement of foreign objects may analogously be applied to any target for displacement or removal, including, for example, bodily structures or materials.

The term “resilient” refers to a component, device, or object that is formed with a particular shape, that can then be elastically deformed into a different shape, but that can return to the original shape when unconstrained. For example, a resilient prong may be formed with a first shape, the resilient prong may then be constrained (i.e., disposed within a lumen of a sheath) to elastically deform it into a second shape, then unconstrained (i.e., displaced out of the lumen of the sheath) such that the resilient prong returns to its first shape. Shape memory alloys, including NITINOL, are examples of resilient materials.

FIG. 1Aillustrates an embodiment of a medical grasping device100. As depicted, the medical grasping device100can comprise an elongate member110. The medical grasping device100may also comprise at least two resilient prongs120,130. In the illustrated embodiment, the medical grasping device100comprises a first resilient prong120and a second resilient prong130. In other embodiments, the medical grasping device100may comprise three resilient prongs, four resilient prongs, or more resilient prongs. The first and second resilient prongs120,130are coupled to the elongate member110at a distal end114of the elongate member110, and each of the first and second resilient prongs120,130can extend distally from the distal end114of the elongate member110.

At least one engagement feature140amay be disposed at a distal end124of the first resilient prong120. Likewise, at least one engagement feature140bmay be disposed at a distal end134of the second resilient prong130. In the illustrated embodiment, the engagement feature140acomprises one curved portion142a, wherein the curved portion142ais disposed at the distal end124of the first resilient prong120. Also, as illustrated, the engagement feature140bcomprises two curved portions142b,142c, wherein the two curved portions142b,142care disposed at the distal end134of the second resilient prong130. The one curved portion142aof the first resilient prong120may be configured to interlock or engage with the two curved portions142b,142cof the second resilient prong130when the distal ends124,134of the first and second resilient prongs120,130, respectively, are displaced toward each other (as discussed in further detail below). The interlocking of the curved portions142a,142b,142cmay be configured to secure a target foreign object disposed within a body lumen. For example, a target foreign object may be secured before any force is applied on the target foreign object by a medical grasping device. Such a configuration may facilitate a traumatic, or less traumatic, securement of the target foreign object prior to displacement of the target foreign object.

Other configurations of engagement features are also contemplated. For example, the engagement features may comprise one or more L-shaped portions (i.e., portions that are not substantially curved). In another example, a first engagement feature may comprise two teeth or projections separated by a gap or slot and a second engagement feature, which is configured to interlock with the first engagement feature, wherein the second engagement feature may comprise a single tooth or projection configured to be disposed, at least partially, within the gap or slot of the first engagement feature.

With continued reference toFIG. 1A, each of the first resilient prong120and the second resilient prong130curves outwardly from an extension of a longitudinal axis10of the elongate member110. In contrast, each of the curved portions142a,142b,142ccurves inwardly toward the extension of the longitudinal axis10of the elongate member110.

As depicted, each of the first resilient prong120and the second resilient prong130extends from the distal end114of the elongate member110such that the first resilient prong120extends in a substantially opposite direction from the second resilient prong130. Stated another way, the extension of the first resilient prong120from the elongate member110generates or forms a substantially mirror image of the extension of the second resilient prong130from the elongate member110, and vice versa. As illustrated, the first resilient prong120extends from a first portion at the distal end114of the elongate member110and the second resilient prong130extends from a second portion at the distal end114of the elongate member110, wherein the first position and the second position are disposed at substantially opposite positions along a circumference of the distal end114of the elongate member110. As such, each of the first resilient prong120and the second resilient prong130is substantially disposed within a single plane. Other dispositions of the first and second resilient prongs120,130around the circumference of the distal end114of the elongate member are also within the scope of this disclosure.

FIG. 1Bis a side view of a portion of the medical grasping device100ofFIG. 1A. In the illustrated embodiment, the relative position of the first resilient prong120in relation to the position of the second resilient prong130is shown. As described above, at least one engagement feature140acan be disposed at the distal end124of the first resilient prong120. Likewise, at least one engagement feature140bmay be disposed at the distal end134of the second resilient prong130. The engagement feature140aof the first resilient prong120, as illustrated, comprises one curved portion142a, wherein the curved portion142ais disposed at the distal end124of the first resilient prong120. The engagement feature140bof the second resilient prong130comprises two curved portions142b,142c, wherein the curved portions142b,142care disposed at the distal end134of the second resilient prong130. As depicted, the one curved portion142aof the first resilient prong120is configured to interlock with or engage with the two curved portions142b,142cof the second resilient prong130. For example, when the distal ends124,134of the first and second resilient prongs120,130, respectively, are displaced toward each other the engagement features140a,140bmay interlock with each other.

Upon interlocking of the one curved portion142aof the first resilient prong120and the two curved portions142b,142cof the second resilient prong130, the one curved portion142aof the first resilient prong120can be configured to be at least partially disposed at a position between the two curved portions142b,142cof the second resilient prong130(i.e., wherein the position comprises a gap or space between the two curved portions142b,142cof the engagement feature140b).

FIG. 1Cis a front view of a portion of the medical grasping device100ofFIG. 1A. As depicted, the first resilient prong120comprises a concave proximal portion126and a convex distal portion128. Likewise, the second resilient prong130comprises a concave proximal portion136and a convex distal portion138. The concave proximal portions126,136are concave with respect to the extension of the longitudinal axis10of the elongate member110, and the concave proximal portions126,136are positioned between the elongate member110and the convex distal portions128,138, respectively. The convex distal portions128,138are convex with respect to the extension of the longitudinal axis10of the elongate member110, and the convex distal portions128,138extend from distal ends of the concave proximal portions126,136, respectively.

In some embodiments, the first resilient prong120and/or the second resilient prong130may comprise a first curve centered on a point outside of the first curve and a second curve centered on a point inside of the second curve. The radius of the first curve may be different from the radius of the second curve. Additionally, the first curve and the second curve may comprise a constant and/or a changing radius of curvature. In various embodiments, the first resilient prong120and/or the second resilient prong130may comprise an inflection point where the first resilient prong120and/or the second resilient prong130changes concavity.

In certain other embodiments, the first resilient prong may be curved (i.e., the first resilient prong may comprise a concave proximal portion and a distal convex portion); however, the second resilient prong may be substantially straight. For example, the second resilient prong may extend substantially parallel with respect to the extension of the longitudinal axis10of the elongate member110or the second resilient prong may extend, without significant curvature, at a substantially constant angle with respect to the extension of the longitudinal axis10. The second resilient prong may also be configured to abut a luminal surface without significantly displacing and/or traumatizing the luminal surface. Such configurations of the first and second resilient prongs120,130may allow or permit the substantially straight second resilient prong to be more easily displaced along or adjacent the luminal surface. Additionally, such a configuration of the first and second resilient prongs120,130may allow or permit the substantially straight second resilient prong to be disposed in closer contact with the luminal surface in contrast to the curved first resilient prong which may extend away from the luminal surface. For example, if the target foreign object is closely embedded or engaged with the luminal surface, the straight resilient prong may be configured to engage or interact more easily with the target foreign object than the curved resilient prong.

In various embodiments, the medical grasping device100may further comprise a third resilient prong extending from the distal end114of the elongate member110. Each of the first resilient prong, the second resilient prong, and the third resilient prong may extend from positions at the distal end114of the elongate member110, and the positions may be substantially evenly spaced around a circumference of the elongate member110. In various other embodiments, the medical grasping device may comprise four resilient prongs, wherein the four resilient prongs extend from the distal end114of the elongate member110and extend from positions at the distal end114of the elongate member110wherein the positions may be substantially evenly spaced around the circumference of the elongate member110. Medical grasping devices comprising five, six, or more resilient prongs are also within the scope of this disclosure.

In some embodiments, components of the medical grasping device100may be integrally formed. For example, the elongate member110and the first and second resilient prongs120,130may be integrally formed. In some other embodiments, components of the medical grasping device100may be discretely formed. For example, the elongate member110and the first and second resilient prongs120,130may be discretely formed and subsequently coupled to each other.

FIGS. 2A and 2Billustrate another embodiment of a medical grasping device that can, in certain respects, resemble components of the medical grasping device described in connection withFIGS. 1A and 1B. It will be appreciated that all the illustrated embodiments may have analogous features. Accordingly, like features are designated with like reference numerals, with the leading digits incremented to “2.” For instance, the elongate member is designated as “110” inFIGS. 1A and 1B, and an analogous elongate member is designated as “210” inFIGS. 2A and 2B. Relevant disclosure set forth above regarding similarly identified features thus may not be repeated hereafter. Moreover, specific features of the medical grasping device and related components shown inFIGS. 1A and 1Bmay not be shown or identified by a reference numeral in the drawings or specifically discussed in the written description that follows. However, such features may clearly be the same, or substantially the same, as features depicted in other embodiments and/or described with respect to such embodiments. Accordingly, the relevant descriptions of such features apply equally to the features of the medical grasping device ofFIGS. 2A and 2B. Any suitable combination of the features, and variations of the same, described with respect to the medical grasping device and components illustrated inFIGS. 1A and 1Bcan be employed with the medical grasping device and components ofFIGS. 2A and 2B, and vice versa. This pattern of disclosure applies equally to further embodiments depicted in subsequent figures and described hereafter.

The medical grasping device200ofFIG. 2Acomprises an elongate member210. In some embodiments, the elongate member may be configured for displacement through a body lumen (e.g., a vessel of a patient). The medical grasping device200further comprises a plurality of resilient prongs extending from a distal end214of the elongate member210. In the illustrated embodiment, the medical grasping device200comprises a first resilient prong220and a second resilient prong230. Further, first and second engagement features240a,240bare coupled to distal ends224,234of each of the first and second resilient prongs220,230. In some embodiments, each of the first and second resilient prongs220,230, respectively, and the first and second engagement features240a,240bare configured to secure a foreign object disposed within a body lumen.

A medical grasping device assembly may comprise a delivery sheath250disposed around at least a portion of the medical grasping device200, such that the medical grasping device200is longitudinally displaceable within the delivery sheath250. For example, the elongate member210and the medical grasping device200may be proximally and distally displaced within a lumen252of the delivery sheath250. Upon proximal displacement of the plurality of resilient prongs into the lumen252of the delivery sheath250, the first and second engagement features240a,240bcan be displaced toward each other, and upon distal displacement of the plurality of resilient prongs out of the lumen252of the delivery sheath250the first and second engagement features240a,240bcan be displaced away from each other. Stated another way, upon proximal displacement of the plurality of resilient prongs within or into the lumen252of the delivery sheath250, a constraining force may be exerted on the first and second engagement features240a,240b, at least in part by the delivery sheath, such that the first and second engagement features240a,240bare displaced or moved toward each other.

Further, upon distal displacement of the plurality of resilient prongs away from or out of the lumen252of the delivery sheath250the constraining force may be removed from the first and second engagement features240a,240bsuch that the first and second engagement features240a,240bdisplace or move away from each other. In some embodiments, partial constraint of proximal portions of resilient prongs, similar to the first and second resilient prongs220,230, can cause displacement or movement of engagement features, similar to the first and second engagement features240a,240b, toward each other.

In some embodiments, upon proximal displacement of the first and second resilient prongs220,230into the lumen252of the delivery sheath250, the first engagement feature240amay be configured to interlock with the second engagement feature240b. The interlocking of the first engagement feature240aand the second engagement feature240bmay be configured to secure a foreign object within a body lumen.

In certain embodiments, the medical grasping device200may further comprise an actuator (not shown) configured to alternatively displace the plurality of resilient prongs into and/or out of the lumen252of the delivery sheath250. For example, the actuator may be configured to actuate the medical grasping device200such that the plurality of resilient prongs and/or the engagement features may engage and/or secure a foreign object within a body lumen. In various embodiments, the actuator may be spring loaded such that upon release of the actuator by a practitioner, the plurality of resilient prongs can be disposed within the lumen252of the delivery sheath250. In various other embodiments, the actuator may be spring loaded such that upon release of the actuator by a practitioner, the plurality of resilient prongs can be displaced outside and distally from within the lumen252of the delivery sheath250.

In the illustrated embodiment, the first engagement feature240acomprises one curved portion242a, wherein the curved portion242ais disposed at the distal end224of the first resilient prong220. Also, the second engagement feature240bcomprises two curved portions242b,242c, wherein the curved portions242b,242care disposed at the distal end234of the second resilient prong230. The curved portions242a,242b,242cof the medical grasping device200are generally more tapered relative to the curved portions142a,142b,142cof the medical grasping device100ofFIGS. 1A and 1B. For example, a distal end of the curved portion242atapers to a wedge-like configuration or shape, whereas a distal end of the curved portion142ais blunt relative to the distal end of the curved portion242a. Additionally, distal ends of the curved portions242b,242ccomprise tapered outside lateral sides while distal ends of the curved portions142b,142ccomprise tapered inside lateral sides. Other configurations or shapes of the engagement features and/or curved portions are also contemplated. For example, the configurations or shapes of the engagement features and/or the curved portions may be designed for different purposes or uses. For example, engagement features and/or curved portions comprising a first shape may be better suited for the engagement and retrieval of a stent while engagement features and/or curved portions comprising a second shape may be better suited for engagement and retrieval of a vascular filter.

With continued reference toFIG. 2A, each of the first and second engagement features240a,240bcomprises at least one curved portion242a,242b,242c, wherein the at least one curved portion242a,242b,242ccurves inwardly toward an extension of a longitudinal axis10of the elongate member210.

FIG. 2Bis a side view of a portion of the medical grasping device200ofFIG. 2A. In the illustrated embodiment, the position of the first resilient prong220relative to the position of the second resilient prong230is shown. The first engagement feature240acan be disposed at the distal end224of the first resilient prong220. Likewise, the second engagement feature240bcan be disposed at the distal end234of the second resilient prong230. Additionally, the first engagement feature240acomprises one curved portion242a, wherein the curved portion242ais disposed at the distal end224of the first resilient prong220. Also, the second engagement feature240bcomprises two curved portions242b,242c, wherein the curved portions242b,242care disposed at the distal end234of the second resilient prong230. As described above, the one curved portion242aof the first resilient prong220is configured to interlock or engage with the two curved portions242b,242cof the second resilient prong230when the distal ends224,234of the first and second resilient prongs220,230, respectively, are displaced toward each other. Upon interlocking of the one curved portion242aof the first resilient prong220and the two curved portions242b,242cof the second resilient prong230, the one curved portion242aof the first resilient prong220can be configured to be at least partially disposed at a position (i.e., in a gap or space) between the two curved portions242b,242cof the second resilient prong230.

FIG. 3Aillustrates yet another embodiment of a medical grasping device300. The medical grasping device300also comprises an elongate member310. A cross-section of the elongate member310can be substantially circular. In some embodiments, however, the cross-section of the elongate member310may be substantially ovoid, square, triangular, or otherwise shaped. The medical grasping device300further comprises a first resilient prong320and a second resilient prong330, wherein each of the first resilient prong320and the second resilient prong330is coupled to and extend from a distal end314of the elongate member310.

The second resilient prong330of the illustrated embodiment further comprises a window or opening331extending longitudinally through at least a portion of the second resilient prong330. As depicted, the first resilient prong320is generally narrower than the second resilient prong330. The window331of the second resilient prong330may result in a second resilient prong330that comprises a substantially similar flexibility or resiliency to the flexibility or resiliency of the first resilient prong320. The opening331may compensate for the greater width of the second resilient prong330relative to the first resilient prong320. For example, the window331disposed through the wider second resilient prong330may generate or result in a second resilient prong330that comprises substantially comparable or equal amounts of material as the narrower first resilient prong320, and as such the first and second resilient prongs320,330may comprise substantially similar flexibilities or resiliencies.

A cross-section of each of the first resilient prong320and the second resilient prong330can be substantially semicircular. In some other embodiments, however, the cross-sections of the first and second resilient prongs320,330may be substantially linear, L-shaped, or otherwise shaped. In some embodiments, a medical grasping device may be cut from a tube of a shape memory alloy. For example, the medical grasping device300may be cut from a tube of NITINOL and formed (i.e., be heat set) such that the first resilient prong320and the second resilient prong330are configured to move away from each other upon displacement of the medical grasping device out of a lumen of a delivery sheath. In some other embodiments, a medical grasping device may be milled from a block of material (i.e., a block of a metal).

FIG. 3Bis a side view of the medical grasping device300ofFIG. 3A. As illustrated, the medical grasping device300comprises the elongate member310and first and second resilient prongs320,330coupled to and extending from the distal end314of the elongate member310. From this view, the alignment of the first and second resilient prongs320,330and their associated first and second engagement features340a,340b, respectively, can be seen. The first and second engagement features340a,340b, similar to the engagement features discussed above, can be configured to interlock with each other (i.e., via curved portions).

FIGS. 4A-4Edepict an illustrative method of using a medical grasping device assembly of the present disclosure to retrieve a target foreign object (e.g., a vascular filter, as illustrated) from a body lumen (e.g., a vessel as illustrated) of a patient. AlthoughFIGS. 4A-4Edepict a method of retrieving the vascular filter70from the vessel60, methods of using the medical grasping device assembly of the present disclosure may also comprise methods of retrieving any target foreign object from within any body lumen.FIG. 4Ais a side view of an embodiment of a medical grasping device assembly disposed with a lumen62of the vessel60. The medical grasping device assembly comprises a grasping device400, or medical grasping device, disposed within a lumen452of a delivery sheath450. The method of retrieving the vascular filter70, or the target foreign object, can comprise disposing the grasping device400and at least a distal end of the delivery sheath450to a position within the vessel60at or adjacent the vascular filter70. As depicted, the grasping device400comprises an elongate member410and a plurality of resilient prongs, wherein each of the plurality of resilient prongs is coupled to and extends from a distal end414of the elongate member410. Further, at least one engagement feature440a,440bcan be disposed at distal ends424,434of each of the first and second resilient prongs420,430, respectively. In some embodiments, as described above, the engagement features440a,440bmay be configured to interlock to secure the vascular filter70, or target foreign object. The target foreign object70can be selected from at least one of, but not limited to, a stent, a vascular filter, an embolus, or a bolus.

FIG. 4Bis a side view of the medical grasping device assembly ofFIG. 4Awherein the first and second resilient prongs420,430of the medical grasping device400are at least partially distally displaced from within the lumen452of the delivery sheath450.FIG. 4Cis a side view of the medical grasping device assembly ofFIG. 4Awherein the first and second resilient prongs420,430of the medical grasping device400are fully displaced from within the lumen452of the delivery sheath450. As depicted inFIGS. 4B and 4C, a method of retrieving the vascular filter70, or target foreign object, can also comprise engaging at least one of the engagement features440a,440bwith at least a portion of the vascular filter70. For example, at least one of the engagement features440a,440bmay contact at least a portion of the vascular filter70or at least one of the engagement features440a,440bmay enter a space or volume defined by an outermost boundary of components of the vascular filter70.

In some embodiments, a method of retrieving the target foreign object can further comprise actuating the grasping device400such that at least two of the engagement features440a,440binterlock with each other to secure the engaged target foreign object. In various embodiments, the method of retrieving the target foreign object can also comprise longitudinally displacing the grasping device400to dislodge or free the secured target foreign object from a position within a body lumen. For example, the grasping device may be displaced proximally toward a practitioner to dislodge the target foreign object from the body lumen. In some circumstances, tissue ingrowth may be disposed around at least a portion of the target foreign object. As used herein, the term “tissue ingrowth” refers to tissue at or adjacent a target foreign object that has grown in and/or around at least a portion of the target foreign object. The practitioner may increase a longitudinal force applied both proximally and distally upon the secured target foreign object to dislodge or free the target foreign object from the tissue ingrowth.

FIG. 4Dis a side view of the medical grasping device assembly ofFIG. 4Awherein the medical grasping device400has secured the vascular filter70. In the illustrated embodiment, the practitioner may proximally displace the plurality of resilient prongs within the lumen452of the delivery sheath450. The delivery sheath450can be disposed around at least a portion of the grasping device400, and upon proximal displacement of the plurality of resilient prongs within the lumen452of the delivery sheath450, an interaction between at least a portion of the delivery sheath450and the plurality of resilient prongs may act to displace each of the plurality of resilient prongs toward each other. Further, as depicted, the at least two engagement features440a,440bcan interlock prior to displacement, or complete displacement, of the plurality of resilient prongs within the lumen452of the delivery sheath450. The interlocking of the at least two engagement features440a,440bmay secure the vascular filter70such that the vascular filter70may be displaced by the grasping device400within the lumen452of the delivery sheath450. Thus, the vascular filter70may be secured by the medical grasping device400such that the vascular filter70is encircled by the medical grasping device400before a force is exerted on the vascular filter70. This can allow or permit securement of the vascular filter70without, or with decreased, trauma to the vessel60or other body part, as the steps of securing the vascular filter70may be executed without displacing the vascular filter70. In other words, the process of securing the vascular filter70may not disturb the placement of the vascular filter70. In turn, this may facilitate a more controlled eventual displacement of the vascular filter70as the vascular filter70may be coupled to the medical grasping device400during any displacement of the vascular filter70.

FIG. 4Eis a side view of the medical grasping device assembly ofFIG. 4Awherein the medical grasping device400and the secured vascular filter70have been disposed within the lumen452of the delivery sheath450. As illustrated, the method can further comprise disposing the secured target foreign object70within the lumen452of the delivery sheath450. In certain embodiments, the method may also comprise removing or retrieving each of the delivery sheath450, the grasping device400, and the secured target foreign object70from the body lumen60of the patient.

FIGS. 5A-5Cillustrate another embodiment of a medical grasping device500. As with the other embodiments disclosed herein, the embodiment ofFIGS. 5A-5Cmay have analogous features to other embodiments. Disclosure set forth above with respect to these other embodiments, for example the embodiment ofFIGS. 1A-1C, but thus be analogously applied to the embodiment ofFIGS. 5A-5C.

FIGS. 5A and 5Billustrate an embodiment of a medical grasping device500in an open configuration.FIG. 5Cillustrates the medical grasping device ofFIGS. 5A and 5Bin a closed configuration. As depicted, the medical grasping device500can comprise an elongate member510. The medical grasping device500may also comprise at least two resilient prongs520,530. In the illustrated embodiment, the medical grasping device500comprises a first resilient prong520and a second resilient prong530. In other embodiments, the medical grasping device500may comprise three resilient prongs, four resilient prongs, or more resilient prongs. The first and second resilient prongs520,530are coupled to the elongate member510at a distal end514of the elongate member510, and each of the first and second resilient prongs520,530can extend distally from the distal end514of the elongate member510.

At least one engagement feature540amay be disposed at a distal end524of the first resilient prong520. Likewise, at least one engagement feature540bmay be disposed at a distal end534of the second resilient prong530. In the illustrated embodiment, the engagement feature540acomprises one curved portion542a, wherein the curved portion542ais disposed at the distal end524of the first resilient prong520. Also, as illustrated, the engagement feature540bcomprises two curved portions542b,542c, wherein the two curved portions542b,542care disposed at the distal end534of the second resilient prong530. The one curved portion542aof the first resilient prong520may be configured to interlock or engage with the two curved portions542b,542cof the second resilient prong530when the distal ends524,534of the first and second resilient prongs520,530, respectively, are displaced toward each other (as discussed in further detail below). The interlocking of the curved portions542a,542b,542cmay be configured to secure a target foreign object disposed within a body lumen. For example, a target foreign object may be secured before any force is applied on the target foreign object by a medical grasping device. Such a configuration may facilitate a traumatic, or less traumatic, securement of the target foreign object prior to displacement of the target foreign object.

With comparison to the embodiment ofFIGS. 1A-1C, the medical grasping device500ofFIGS. 5A-5C, the curved portion542afurther comprises a distal lip542a′. The distal lip542a′ may be configured to contact with an interior portion distal portion534of the second resilient prong530. As shown inFIG. 5C, contact between the distal lip542a′ and the distal portion534of the second resilient prong530may provide a positive stop for relative displacement between the first resilient arm520and the second resilient arm530. This positive stop may prevent over extension of the first resilient prong520and second resilient prong530and/or may prevent the curved portion542a from passing through the two curved portions542b,542cof the second resilient prong530and catching on an exterior surface of the second resilient prong530.

As discussed above, the first resilient prong520and second resilient prong530may be constrained within the sheath or catheter when in a closed configuration, such as that ofFIG. 5C. When in such a closed configuration, constraints on the curved resilient prongs520,530may thus result in a grasping or closing force acting on the resilient prongs520,530. The positive stop provided by the distal lip542a′ may prevent the distal ends of the resilient prongs520,530from over-extension, such as by preventing the distal ends of the resilient prongs520,530from crossing each other. This may, in turn, prevent the resilient prongs520,530from catching in a closed position, for example, by preventing the first engagement feature542afrom snapping past the second resilient prong530and engagement with an exterior surface of the second resilient prong530. Such engagement could potentially prevent the medical grasping device500from reopening once the constraining force is removed.

Also as compared to the embodiment ofFIGS. 1A-1C, the first resilient prong520and the second resilient prong530may comprise a different curvature. Various scales, sizes, and curvatures of resilient prongs are within the scope of this disclosure. As with other embodiments disclosed herein, the first resilient prong520and the second resilient prong530may be laser cut from a single piece of material or may be stamped from a single material and coupled together with a collar or other coupling member.

With reference toFIG. 5A, each of the first resilient prong520and the second resilient prong530curves outwardly from an extension of a longitudinal axis12of the elongate member510. In contrast, each of the curved portions542a,542b,542ccurves inwardly toward the extension of the longitudinal axis12of the elongate member510. Again, this shape and curvature may differ from other embodiments, such as the embodiment ofFIGS. 1A-1C.

As depicted, each of the first resilient prong520and the second resilient prong530extends from the distal end514of the elongate member510such that the first resilient prong520extends in a substantially opposite direction from the second resilient prong530. Stated another way, the extension of the first resilient prong520from the elongate member510generates or forms a substantially mirror image of the extension of the second resilient prong530from the elongate member510, and vice versa. As illustrated, the first resilient prong520extends from a first portion at the distal end514of the elongate member510and the second resilient prong530extends from a second portion at the distal end514of the elongate member510, wherein the first position and the second position are disposed at substantially opposite positions along a circumference of the distal end514of the elongate member510. As such, each of the first resilient prong520and the second resilient prong530is substantially disposed within a single plane. Other dispositions of the first and second resilient prongs520,530around the circumference of the distal end514of the elongate member are also within the scope of this disclosure.

FIG. 5Bis a side view of a portion of the medical grasping device500ofFIG. 5A, with the medical grasping device disposed in an open configuration as inFIG. 5A. In the illustrated embodiment, the relative position of the first resilient prong520in relation to the position of the second resilient prong530is shown. As described above, at least one engagement feature540acan be disposed at the distal end524of the first resilient prong520. Likewise, at least one engagement feature540bmay be disposed at the distal end534of the second resilient prong530. The engagement feature540aof the first resilient prong520, as illustrated, comprises one curved portion542a, wherein the curved portion542ais disposed at the distal end524of the first resilient prong520. The engagement feature540bof the second resilient prong530comprises two curved portions542b,542c, wherein the curved portions542b,542care disposed at the distal end534of the second resilient prong530. The distal lip542a′ of the curved portion542aof the first resilient prong520is also shown. As depicted, the one curved portion542aof the first resilient prong520is configured to interlock with or engage with the two curved portions542b,542cof the second resilient prong530. For example, when the distal ends524,534of the first and second resilient prongs520,530, respectively, are displaced toward each other the engagement features540a,540bmay interlock with each other. The distal lip542a′ may provide a positive stop as described above.

Upon interlocking of the one curved portion542aof the first resilient prong520and the two curved portions542b,542cof the second resilient prong530, the one curved portion542aof the first resilient prong520can be configured to be at least partially disposed at a position between the two curved portions542b,542cof the second resilient prong530(i.e., wherein the position comprises a gap or space between the two curved portions542b,542cof the engagement feature540b). Again, the distal lip542a′ may provide a positive stop though interaction with the second resilient prong530, preventing over-extension of the first resilient prong520and second resilient prong530with respect to each other.

FIG. 5Cis a front view of a portion of the medical grasping device500ofFIG. 5A, with the first resilient prong520and the second resilient prong530disposed in a closed configuration. As depicted, the first resilient prong520comprises a concave proximal portion526and a convex distal portion528. Likewise, the second resilient prong530comprises a concave proximal portion536and a convex distal portion538. The concave proximal portions526,536are concave with respect to the extension of the longitudinal axis12of the elongate member510, and the concave proximal portions526,536are positioned between the elongate member510and the convex distal portions528,538, respectively. The convex distal portions528,538are convex with respect to the extension of the longitudinal axis12of the elongate member510, and the convex distal portions528,538extend from distal ends of the concave proximal portions526,536, respectively. As discussed above, in this closed configuration the distal lip542a′ is in contact with an interior surface of the distal portion534of the second resilient prong530. This contact may provide a positive stop and may aid in preventing the first resilient prong520and second resilient prongs530from crossing each other when the medical grasping device500is constrained in a closed configuration.

In some embodiments, the first resilient prong520and/or the second resilient prong530may comprise a first curve centered on a point outside of the first curve and a second curve centered on a point inside of the second curve. The radius of the first curve may be different from the radius of the second curve. Additionally, the first curve and the second curve may comprise a constant and/or a changing radius of curvature. In various embodiments, the first resilient prong520and/or the second resilient prong530may comprise an inflection point where the first resilient prong520and/or the second resilient prong530changes concavity.

In certain other embodiments, the first resilient prong may be curved (i.e., the first resilient prong may comprise a concave proximal portion and a distal convex portion); however, the second resilient prong may be substantially straight. For example, the second resilient prong may extend substantially parallel with respect to the extension of the longitudinal axis12of the elongate member110or the second resilient prong may extend, without significant curvature, at a substantially constant angle with respect to the extension of the longitudinal axis12. The second resilient prong may also be configured to abut a luminal surface without significantly displacing and/or traumatizing the luminal surface. Such configurations of the first and second resilient prongs520,530may allow or permit the substantially straight second resilient prong to be more easily displaced along or adjacent the luminal surface. Additionally, such a configuration of the first and second resilient prongs520,530may allow or permit the substantially straight second resilient prong to be disposed in closer contact with the luminal surface in contrast to the curved first resilient prong which may extend away from the luminal surface. For example, if the target foreign object is closely embedded or engaged with the luminal surface, the straight resilient prong may be configured to engage or interact more easily with the target foreign object than the curved resilient prong.

In various embodiments, the medical grasping device500may further comprise a third resilient prong extending from the distal end514of the elongate member510. Each of the first resilient prong, the second resilient prong, and the third resilient prong may extend from positions at the distal end514of the elongate member510, and the positions may be substantially evenly spaced around a circumference of the elongate member510. In various other embodiments, the medical grasping device may comprise four resilient prongs, wherein the four resilient prongs extend from the distal end514of the elongate member510and extend from positions at the distal end514of the elongate member510wherein the positions may be substantially evenly spaced around the circumference of the elongate member510. Medical grasping devices comprising five, six, or more resilient prongs are also within the scope of this disclosure.

Again, as discussed above, in some embodiments, components of the medical grasping device500may be integrally formed. For example, the elongate member510and the first and second resilient prongs520,530may be integrally formed. In some other embodiments, components of the medical grasping device500may be discretely formed. For example, the elongate member510and the first and second resilient prongs520,530may be discretely formed and subsequently coupled to each other.

References to approximations are made throughout this specification, such as by use of the term “substantially.” For each such reference, it is to be understood that, in some embodiments, the value, feature, or characteristic may be specified without approximation. For example, where qualifiers such as “about” and “substantially” are used, these terms include within their scope the qualified words in the absence of their qualifiers. For example, where the term “substantially straight” is recited with respect to a feature, it is understood that in further embodiments, the feature can have a precisely straight configuration.

The claims following this written disclosure are hereby expressly incorporated into the present written disclosure, with each claim standing on its own as a separate embodiment. This disclosure includes all permutations of the independent claims with their dependent claims. Moreover, additional embodiments capable of derivation from the independent and dependent claims that follow are also expressly incorporated into the present written description.

Without further elaboration, it is believed that one skilled in the art can use the preceding description to utilize the invention to its fullest extent. The claims and embodiments disclosed herein are to be construed as merely illustrative and exemplary, and not a limitation of the scope of the present disclosure in any way. It will be apparent to those having ordinary skill in the art, with the aid of the present disclosure, that changes may be made to the details of the above-described embodiments without departing from the underlying principles of the disclosure herein. In other words, various modifications and improvements of the embodiments specifically disclosed in the description above are within the scope of the appended claims. Moreover, the order of the steps or actions of the methods disclosed herein may be changed by those skilled in the art without departing from the scope of the present disclosure. In other words, unless a specific order of steps or actions is required for proper operation of the embodiment, the order or use of specific steps or actions may be modified. The scope of the invention is therefore defined by the following claims and their equivalents.