Patent Publication Number: US-2021186471-A1

Title: Articulating needles and related methods of use

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This patent application claims the benefit under 35 U.S.C. § 119 to U.S. Provisional Patent Application No. 62/464,785, filed on Feb. 28, 2017, the entirety of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     Aspects of the present disclosure relate to articulating needles, and related methods of use. 
     INTRODUCTION 
     A biopsy entails the surgical removal of tissue or cells from the body of a patient for pathological examination of the collected sample. A purpose of taking a biopsy sample is often to look for cellular shape changes represented in the collected sample. The identification of particular cellular shape changes in a collected specimen can be instrumental in the identification of cancer in a patient. 
     Endoscopes are often used to access and visualize a patient&#39;s anatomical lumen during a medical procedure. Once the endoscope is positioned in the desired body portion, a biopsy instrument can be advanced through the working channel of the endoscope to the desired body portion. The endoscopic and biopsy instruments then may be manipulated as desired for visualization and specimen sampling, respectively. 
     Smaller diameter endoscopes help reduce unnecessary trauma to the tissues of a patient, and provide access to more diverse categories of patient body lumens. These endoscopes often have smaller working channels, which limit the size of auxiliary instruments that can be used with the endoscope. This, in turn, limits the size, and often the quality of, any biopsy specimen collected. 
     A needle biopsy can be performed with a stylet-needle shaft having a tissue retaining recess formed in a lateral side of the area close to the needle tip. When the needle is inserted into tissue from which a sample is desired, a portion of tissue extends into the recess. Such needle biopsy devices often cannot be positioned in flexible small diameter positioning devices because the puncturing stylet-needle is rigid. 
     SUMMARY 
     In one aspect, the present disclosure is directed to a medical device. The medical device may include a needle, including a plurality of links and a distal tip, reciprocally movable between a first configuration and a second configuration, and a conduit including a lumen extending through the needle, the conduit being coupled to the distal tip, wherein longitudinal movement of the conduit is configured to transition the needle between the first configuration and the second configuration. 
     The needle may have a first rigidity in the first configuration, and a second rigidity greater than the first rigidity in the second configuration. Application of a force to the distal tip in the first configuration may cause the plurality of links and the distal tip to change orientation relative to one another, and application of the force to the distal tip in the second configuration may not cause the plurality of links and the distal tip to change orientation relative to one another. Fluid flow through the needle may pass through the lumen of the conduit, and may exit the needle only at the distal tip. The plurality of links may ride loosely along an outer surface of the conduit in the first configuration. The medical device may include a spring configured to bias the needle into the first configuration. A proximal force applied to the conduit while the needle is in the first configuration may compress the spring and transition the needle into the second configuration. Release of the proximal force while the needle is in the second configuration may allow the needle to transition back to the first configuration. The medical device may include a handle having a body, an actuator movable relative to the body, a first stop on an outer surface of the conduit, a second stop extending radially inward from an inner surface of the body, wherein the spring may be between the first stop and the second stop. The conduit may be coupled to a distal end of the actuator. The longitudinal movement of the conduit may be relative to the plurality of links. The conduit may be fixed to the distal tip. At least one of the plurality of links may have a protrusion that engages a surface of an adjacent link. The needle may include a radius of curvature in the second configuration. The needle may have a greater length in the first configuration than in the second configuration. The needle tip may include a distalmost point splayed radially outward from a remainder of the distal tip, wherein the distalmost point may be located at an end of a path that travels along an entirety of the needle. 
     In another aspect, the present disclosure is directed to a medical device. The medical device may include a needle, including a plurality of links and a distal tip, reciprocally movable between a first configuration and a second configuration, wherein second configuration may be more rigid than the first configuration, a conduit including a lumen extending through the needle, the conduit being fixed to the distal tip, wherein application of a proximal pulling force on the conduit may be configured to transition the needle from the first configuration and the second configuration, and release of the proximal pulling force may be configured to transition the needle from the second configuration to the first configuration. 
     Application of a force to the distal tip in the first configuration may cause the plurality of links and the distal tip to change orientation relative to one another, and application of the force to the distal tip in the second configuration may not cause the plurality of links and the distal tip to change orientation relative to one another. Fluid flow through the needle may pass through the lumen of the conduit, and may exit the needle only at the distal tip. 
     In yet another aspect, the present disclosure is directed to a medical device. The medical device may include a needle, including a plurality of links and a distal tip, reciprocally movable between a first configuration and a second configuration, wherein the needle may have a radius of curvature in the second configuration and may include a distalmost point splayed radially outward from a remainder of the distal tip, the distalmost point being located at an end of a path that travels along an entirety of the needle, and a conduit including a lumen extending through the needle, the conduit being fixed to the distal tip, wherein application of a proximal pulling force on the conduit may be configured to transition the needle from the first configuration and the second configuration, and release of the proximal pulling force may be configured to transition the needle from the second configuration to the first configuration. 
     Fluid flow through the needle may pass through the lumen of the conduit, and may exit the needle only at the distal tip. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various aspects and together with the description, serve to explain the principles of the disclosed aspects. 
         FIG. 1  is a side cross-sectional view of a medical device in a first configuration, according to an aspect of the present disclosure. 
         FIG. 2  is a side cross-sectional view of the medical device of  FIG. 1  in a second configuration. 
         FIG. 3  is a side cross-sectional view of a medical device in a first configuration, according to another aspect of the present disclosure. 
         FIG. 4  is a side cross-sectional view of the medical device of  FIG. 3  in a second configuration. 
         FIG. 5  is a side cross-sectional view of a medical device according to another aspect of the present disclosure. 
         FIG. 6  is a perspective view of a needle, according to another aspect of the present disclosure. 
         FIG. 7A  is a perspective view of a link according to an aspect of the present disclosure. 
         FIG. 7B  is a perspective view of a needle according to an aspect of the present disclosure. 
         FIG. 8A  is a perspective view of a link according to an aspect of the present disclosure. 
         FIG. 8B  is a perspective view of a needle according to an aspect of the present disclosure. 
         FIG. 9A  is a side view of a needle in a first configuration, according to an aspect of the present disclosure. 
         FIG. 9B  is a side view of the needle of  FIG. 9A  in a second configuration. 
         FIG. 10  is a side cross-sectional view of a medical device in a first configuration, according to an aspect of the present disclosure. 
         FIG. 11  is a side cross-sectional view of the medical device of  FIG. 10  in a second configuration. 
         FIG. 12  is a side cross-sectional view of a medical device according to another aspect of the present disclosure. 
         FIG. 13  is a side view of a needle according to an aspect of the present disclosure. 
         FIG. 14  is a perspective view of a medical device according to another aspect of the present disclosure. 
         FIG. 15  is a perspective view of a medical device according to another aspect of the present disclosure. 
         FIG. 16  is a flowchart of a method according to an aspect of the present disclosure. 
         FIG. 17  is a flowchart of a method according to another aspect of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to aspects of the present disclosure, which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts or components. The term “distal” refers to the direction that is away from the user or operator and into the patient&#39;s body. By contrast, the term “proximal” refers to the direction that is closer to the user or operator and away from the patient&#39;s body. 
     Aspects of the present disclosure are directed to medical devices configured to pass through a scope in a loose, flexible state, and extend beyond the distal end of the scope in a rigid state to perform various medical procedures, such as, e.g., collecting tissue in a biopsy procedure or deflecting tissue from one location to another. The ability for a device to hold multiple configurations with different sizes and stiffnesses can enable the devices to be optimized for travel through tortuous anatomy in the flexible state, and optimized for performing a clinical task when positioned distal to the distal end of the scope in the rigid state. 
     A medical device  100  is shown in a first, loose configuration in  FIG. 1 , and in a second, rigid configuration in  FIG. 2 . Medical device  100  may be reciprocally movable between the first and second configurations, and also may be configured to extend through an endoscopic device. Medical device  100  may extend from a proximal end  102  toward a distal end  104 . Medical device  100  may include a handle  106  at proximal end  102 , a plurality of links  108 , and a distal tip  110 . The plurality of links  108  and the distal tip  110  may form a needle  109  when medical device  100  is in the second configuration of  FIG. 2 . 
     Handle  106  may include a body  112 , and an actuator  114  that is slidable or otherwise movable relative to body  112 . Body  112  may include a lumen  116 , and two diametrically opposed grips  118 . Grips  118 , in some aspects, may be held by a physician or other suitable operators using the index and middle fingers, while actuator  114  is held by a thumb of the same hand. A stop  120  may extend into lumen  116  from an inner circumferential surface of body  112 . 
     Links  108  and distal tip  110  may be formed from any suitable material, such as, e.g., a metal, a metal alloy (stainless steel, nitinol, or the like), or a polymer. Each link  108  and distal tip  110  may include a lumen extending therethrough. Distal tip  110  also may include a needle tip at its distal end having any suitable shape, such as, e.g., a bevel tip (as shown in  FIGS. 1 and 2 ), multiple bevels, conical, Sprotte, diamond, Franseen, Tuohy, or the like or any other suitable needle tip shape. In the rigid configuration, links  108  and distal tip  110  form needle  109  suitable for injecting fluids, performing aspiration, collecting biopsy samples, and any other suitable technique that utilizes needles. Any suitable number of links  108  may be used, including, but not limited to one, two, three, four, eight, or more links  108 . 
     A conduit  122  may extend from proximal end  102  toward distal end  104 . Conduit  122  may be fixed or otherwise coupled to actuator  114  at proximal end  102 , and to distal tip  110  at distal end  104  by any suitable mechanism, such as, e.g., snap-fitting, mechanical fasteners, biocompatible adhesives or the like. One or more of links  108  may loosely ride along conduit  122  in the loose configuration. Conduit  122  may include a lumen  124  extending therethrough, and a stop  130  disposed on an outer circumferential surface of conduit  122 . Stop  130  may be distal to stop  120 . Conduit  122  may be formed from any suitable fluid-impermeable material including, e.g., metals, polymers and the like. Conduit  122  may be biased into a straight configuration (shown in  FIGS. 1 and 2 ), but may be configured to flex in order to navigate through tortuous anatomy. However, after flexing, conduit  122  may return to the straight configuration shown in  FIGS. 1 and 2 . Further, conduit  122  may be sufficiently rigid to compress a spring  132  when medical device  100  is transitioned from the loose configuration to the rigid configuration. Spring  132  may be disposed between stop  120  of handle  106 , and stop  130  of conduit  122 . 
     Lumen  124  of conduit  122  may permit fluid and/or tissue flow through needle  109  while needle  109  is in any configuration, including the floppy, loose configuration of  FIG. 1 , and the rigid configuration of  FIG. 2 . In the absence of conduit  122 , fluid and/or tissue travelling through needle  109  may escape needle  109  through gaps between adjacent links  108 . Even in the rigid configuration, small gaps due to manufacturing imperfections may be present between adjacent links  108 , making needle  109  unsuitable for biopsy or fluid delivery in the absence of conduit  122 . In other aspects, however, needle  109  may be fluid tight in the absence of conduit  122  while in the rigid configuration. Fluid delivery and/or aspiration devices may be coupled to a proximal end of conduit  122  to enable sample collection, irrigation, and/or spraying of a target site. Conduit  122  may include a plurality of lumens in order to carry out one or more of these functions sequentially or simultaneously. 
     The loose configuration ( FIG. 1 ) may help medical device  100  navigate through tortuous pathways of the body, or to navigate through the tortuous path of an artificial lumen of a scope extended through a tortuous pathway of the body. Medical device  100  also may be used to deflect tissue or other bodily structures while disposed in its rigid, compact state ( FIG. 2 ). 
     In the loose configuration, the various links  108  may be spaced apart from adjacent links  108 , and may loosely ride along conduit  122 . The distalmost link  108  also may be spaced apart from distal tip  110  in the loose configuration. However, in the rigid configuration, the links  108  of the medical device  100  may directly contact one another in a nested manner, and the distalmost link  108  may contact distal tip  110  in a nested manner. In the loose configuration, the links  108  and distal tip  110  of medical device  100  may change orientation relative to one another in response to an outside force acting on one or more of the links  108  or on the distal tip  110 . In the rigid configuration, the links  108  and distal tip  110  of medical device  100  may not change orientation relative to one another in response to an outside force (such as the same outside force (magnitude and direction) mentioned in the prior sentence) acting on one or more of the links  108  or distal tip  110 . That is, in the rigid configuration, the links  108  and distal tip  110  may form a rigid member that is substantially straight, and which remains substantially straight when contacting tissue or other objects. Thus, distal end  104  of medical device  100  comprising the plurality of links  108  and the distal tip  110  may have a greater rigidity in the rigid configuration than while in the loose configuration. Additionally, the plurality of links  108  and the distal tip  110  may be fixed relative to one another when in the rigid configuration, and may be movable relative to one another in the loose configuration. Needle  900  (measured from a distal end of handle  106 ) also may have a greater length in the loose configuration than when in the rigid configuration, as gaps between adjacent links  108  and/or distal tip  110  present in the loose configuration may be closed after the transition to the rigid configuration. 
     The movement of actuator  114  relative to body  112  may be configured to transition medical device  100  between the loose and rigid configurations. When medical device  100  is in the loose configuration of  FIG. 1 , a proximally directed force may be applied by actuator  114  to conduit  122 . Further, because distal tip  110  is fixed to conduit  122 , the proximal movement of conduit  122  also causes proximal movement of distal tip  110 . Distal tip  110  then may abut a distalmost link of the plurality of links  108 , closing off a gap that existed between distal tip  110  and the distalmost link  108  in the loose configuration. The distalmost link  108  then may abut a link  108  immediately proximal to the distalmost link, and this pattern may be repeated until the gaps between each adjacent link  108  have been closed. Thus, in response to the proximally directed force, medical device  100  may move from the loose configuration of  FIG. 1  to the rigid configuration of  FIG. 2  by compressing spring  132  and causing a gap between distal tip  110  and distalmost link  108 , and gaps between other adjacent links of the plurality of links  108 , to close. In some aspects, the proximally directed force must be maintained to keep medical device  100  in the rigid configuration, although a locking device (not shown) could be used to keep medical device in the rigid configuration. Medical device  100  may be transitioned back to the loose configuration by releasing the proximally directed force acting on conduit  122 , allowing spring  132  to expand longitudinally and force the links  108  and distal tip  110  of medical device  100  away from one another. The links  108  and distal tip  110  may be slack and floppy in the loose configuration. One or more springs (not shown) may be disposed between adjacent links to bias the adjacent links apart from one another. 
     A medical device  300  is shown in a first, loose configuration in  FIG. 3 , and in a second, rigid configuration in  FIG. 4 . Medical device  300  may be reciprocally movable between the first and second configurations like medical device  100 , except that medical device  300  may utilize one or more actuation members  324  instead of conduit  122  to carry out the reciprocal movement between the two configurations. Medical device  300  may extend from a proximal end (not shown) toward a distal end  304 . Medical device  300  may include a handle (not shown) at the proximal end, a plurality of links  308 , and a distal tip  310 . The plurality of links  308  and the distal tip  310  may form a needle  309  when medical device  300  is in the second configuration of  FIG. 4 . Medical device  300  may have substantially similar elasticity, rigidity, and other properties, in the loose and rigid configurations as described above with respect to medical device  100 . 
     Links  308  may be substantially similar to links  108  described above, except that links  308  also may include one or more actuation lumens  326 . In the aspect shown in  FIGS. 3 and 4 , each link  308  includes two actuation lumens  326  that are diametrically opposed from one another (e.g., are separated by an arc length of 180 degrees). However, it is also contemplated that other suitable numbers of actuation lumens and/or spacing may be utilized. Each link  308  also may include a fluid lumen  328  extending through a center of the link  308 . The actuation lumens  326  of the links  308  may be aligned with one another to form actuation lumens  330 , and fluid lumens  328  may be aligned with one another to form a fluid lumen  332 , when medical device  300  is in the rigid configuration. Distal tip  310  may be substantially similar to distal tip  110  described above with reference to  FIGS. 1 and 2 . 
     Actuation members  324  may extend through each of the actuation lumens  330  (and  326 ), and may be coupled at their proximal ends to an actuating mechanism and/or handle. The distal ends of actuation members  324  may be coupled to a proximally-facing surface of distal tip  310 . Actuation members  324  may be wires, cables, rods, tubes, or any other suitable members configured to receive a proximally directed pulling force from the actuating mechanism. The actuating mechanism may include any suitable features configured to apply the proximally directed pulling force to actuation members  324 , including, for aspect, one or more of gears, pulleys, wheels, shafts, and the like. Actuating mechanism  124  may be motorized and/or electrically driven in some aspects, and/or may be actuated manually by the operator. 
     Medical device  300  may include a sleeve  322  that extends through needle  309  from the proximal end to distal end  304 . Sleeve  322  may be formed from a polymer material, such as, e.g., an elastomeric polymeric material. Aspects of polymers that could be used to form sleeve  322  include Teflon®, PTFE, FEP, polyethylene and polypropylene, silicone, polyurethane and polyether-block-amide, among others. Sleeve  322  may be a flexible, floppy, compliant, and/or impermeable membrane. That is, sleeve  322  may have a sheet-like structure configured to collapse upon itself when no outside forces are applied to the sleeve  322 . In some aspects, sleeve  322  may include an elastic and/or resilient material. Sleeve  322  may be a long and flexible rubber tubing. 
     A medical device  500  is shown in  FIG. 5  that is substantially similar to medical device  300 , except that instead of a single sleeve  322 , multiple seals  522  are utilized to facilitate fluid flow through medical device  500 . That is, a seal  522 , which may be formed from substantially similar materials as sleeve  322 , may be coupled to inner surfaces of adjacent links  308 , and to inner surfaces of a distalmost link  308  and distal tip  310  to form an airtight and fluid-tight seal. Seals  522  may be configured to stretch in an axial direction to enable the needle to obtain the loose configuration (not shown). In another aspect, seals  522  may be disposed longitudinally between adjacent links  308 , and longitudinally between distalmost link  308  and distal tip  310 . In this aspect, seals  522  may be annular O-rings or gaskets. The gasket may be formed of an elastomeric material that is somewhat compressible in order to allow the gasket to provide a substantially airtight and fluid seal between adjacent links  308  or between distalmost link  308  and distal tip  310 . In other aspects a sealing coating may be applied to inner and/or end surfaces of links  308 . 
     A needle  600  is shown in  FIG. 6  having an articulation joint  650 . The articulation joint  650  may allow needle  600  to be turned back on itself, e.g., over an arc of 180 degrees. Articulation joint  650  may be generally cylindrical in shape and may include a central lumen  652 , and one or more actuation lumens  654  located in the walls of the articulation joint  650 . Three actuation lumens  654  are in each joint  650 , and are arranged 120 degrees apart from one another. However, other suitable numbers of actuation lumens may alternatively be utilized. 
     One or more living hinges  660  may be formed along a length of articulation joint  650  to facilitate bending of articulation joint  650 . Each living hinge  660  may include a pair of opposing V-shaped cuts  670  on either side of the articulation joint  650 . The cuts  670  may extend circumferentially around the articulation joint. Longitudinally adjacent living hinges  660  may be circumferentially offset from one another by 90 degrees. 
     The articulation joint can be formed by extruding a cylinder with the central and actuation lumens in place and cutting the cylinder tube with a knife, laser, milling tool, water jet, or other material removal mechanism to form the living hinges. Alternatively, articulation joint  650  can be molded with the living hinge joints in place. The angles of the V-shaped cuts  670  that form the hinges may be uniform or may vary along the length of the articulation joint  650 . Similarly, the distance between adjacent living hinges  660  may be uniform or may vary in order to tailor the bending and torque characteristics of the articulation joint  650 . In one aspect, each living hinge  660  has a closing angle of 30 degrees so that six hinges are required to provide 180 degrees of movement. Actuation lumens  654  may be aligned with the widest spacing of the living hinges  660 . However, it may be desirable to offset the actuation lumens  654  with respect to the hinges in order to lessen potential binding of the actuation members in the hinge. Articulation joint  650  may include a biocompatible material that will bend but will not collapse. Suitable materials include polyurethane, polyethylene, polypropylene, or other biocompatible polymers. In another aspect, articulation joint  650  may be formed by 3D-printing or other additive manufacturing techniques. 
     A distal tip  610  that is substantially similar to distal tip  110  may be positioned at the distal end of articulation joint  650 . Additionally, a sleeve that is substantially similar to sleeve  322  may extend through needle  600  to facilitate fluid flow through needle  600 . Thus, in some aspects, fluid and/or tissue acquired during a biopsy with needle  600  must travel through sleeve  322 . Distal tip  610  may be sufficiently long such that no portion of articulation joint  650  needs to be inserted through tissue during acquisition of biopsy samples. In other aspects, articulation joint  650  may be inserted through tissue during sample acquisition. 
     Referring to  FIGS. 7A and 7B , a needle  700  (shown in  FIG. 7B ) is made of a series of stacked links  750  that are positioned adjacent one another and that move with respect to one another. As shown in  FIG. 7A , a link  750  may include an annular ring  752  having a pair of distal facing rocker surfaces or cams  754 , and a pair of proximal facing rocker surfaces or cams  756 . The distal facing cams  754  may be positioned 180 degrees apart on the distal surface of the annular ring  752 , while the proximal facing cams  756  may be positioned 180 degrees apart on the proximal face of the annular ring  752 . In the aspect shown, the proximal facing cams  756  may be oriented at 90 degrees with respect to the distal facing cams  754 . Each cam  754  or  756  may engage and rock against a flat section of an adjacent link  750 . Holes  760  are drilled through the annular ring and through the cams  754  and  756  for passage of actuation members. Upon tension of the actuation members, the links  750  will rock on the surface of the cams  754 ,  756 , thereby bending the needle  700  in the desired direction. Distal facing cams  754  may be aligned with other distal facing cams  754 , and proximal facing cams  756  may be aligned with other proximal facing cams  756  when needle  700  is assembled. A distal tip  710  that is substantially similar to distal tip  110  may be positioned at the distal end of needle  700 . Additionally, a sleeve that is substantially similar to sleeve  322  may extend through needle  700  to facilitate fluid flow through needle  700 . 
       FIG. 8A  shows a link  880 , and  FIG. 8B  shows a needle  800  including a series of stacked links  880 . Each link  880  may include an annular ring having a pair of concave pockets  882  on its proximal surface, and a pair of correspondingly shaped convex cams  884  on its distal surface. On a given link  880 , concave pockets  882  may be offset by 90 degrees with respect to the convex cams  884 . However, the concave pocket  882  of a given link may be aligned with and receive a convex cam  884  of an adjacent link. The correspondingly shaped cams  884  and pockets  882  help prevent the stacked links  880  from rotating with respect to one another. Holes or lumens  886  are formed through the link  880  for passage of one or more actuation members  890 . The holes or lumens  886  may be positioned at the center of the cams and pockets. However, the holes for the actuation members may be offset from the position of the cams and pockets, if desired. Links  880  may be molded from a biocompatible polymer having a relatively slick surface, such as polyurethane, polypropylene, or polyethylene, which reduces friction between adjacent cams and pockets. A distal tip  810  that is substantially similar to distal tip  110  may be positioned at the distal end of needle  800 . Additionally, a sleeve that is substantially similar to sleeve  322  may extend through needle  800  to facilitate fluid flow through needle  800 . 
       FIGS. 9A and 9B  show a needle  900  including a series of stacked links  980  and  981 , each comprising an annular ring having at least one pocket  982  on its proximal surface and at least one correspondingly shaped cam  984  on its distal surface. Links  981  may include an additional cam  985  that extends from the distal surface of link  981 , and that is circumferentially offset from cam  984 . Cam  985  may not be aligned with any corresponding pocket of an adjacent link, and instead may engage and rock with a flat section of a proximal surface of a distally-adjacent link  980  or  981 . The cams  985  of adjacent links  981  may be disposed on diametrically opposed sides in some aspects, as shown in  FIGS. 9A and 9B . Alternatively, the cams  985  of adjacent links  981  may be disposed on the same side of needle  900 , for aspect, to create a larger curvature in the needle  900 . Cams  985  may drive the length and angle of the articulating section of the needle  900 . Lengthening cams  985  may allow for a longer length of needle  900 , and increase the angle that the needle  900  is able to achieve. Positioning various cams  985  in different planes could also allow for the articulating section to take on different shapes other than one radial curve, such as, e.g., an S-curve. 
     Adjacent links  980  may be fully nesting such that no gap exists between adjacent links  980  when in a rigid configuration (shown in  FIG. 9B ). Links  981 , however, may be only partially-nesting or may not nest at all with an adjacent link  980  or  981 . The combination of fully-nesting and non-nesting links may enable needle  900  to have certain portions with high rigidity in the rigid configuration, and other portions that can provide the ability to change the shape and direction of needle  900 . The needle  900  may be transitioned between a loose configuration (shown in  FIG. 9A ) and the rigid configuration by actuation of actuation members  924  in a substantially similar manner as set forth above with respect to medical device  300  described with reference to  FIGS. 3 and 4 . A distal tip  910  that is substantially to distal tip  110  may be positioned at the distal end of needle  900 . Additionally, a sleeve that is substantially similar to sleeve  322  may extend through needle  900  to facilitate fluid flow through needle  900 . 
     A medical device  1000  is shown in a first, flexible configuration in  FIG. 10 , and in a second, rigid configuration in  FIG. 11 . Medical device  1000  may be reciprocally movable between the first and second configurations, and also may be configured to extend through an endoscopic device. Medical device  1000  may extend from a proximal end  1002  toward a distal end  1004 . Medical device  1000  may include a handle  1006  at proximal end  1002 , and a needle  1009  extending distally from handle  1006 . 
     Handle  1006  may include a body  1012 , and an actuator  1014  that is slidable or otherwise movable relative to body  1012 . Body  1012  may include a lumen  1016 , and two diametrically opposed grips  1018 . Handle  1006  may be substantially similar to handle  106  described with reference to  FIGS. 1 and 2 . A stop  1020  may extend into lumen  1016  from an inner circumferential surface of body  1012 . 
     Needle  1009  may be formed from any suitable material, such as, e.g., a metal, a metal alloy (stainless steel, nitinol, or the like), or a polymer. The distal end of needle  1009  also may include a needle tip having any suitable shape, such as, e.g., a bevel tip, multiple bevels, conical, Sprotte, diamond, Franseen, Tuohy, or the like or any other suitable needle tip shape. In the rigid configuration, needle  1009  may be suitable for injecting fluids, aspirating, collecting biopsy samples, and any other suitable technique that utilizes needles. Needle  1009  may include one or more notches  1026  that are positioned on the same side of needle  1009 . 
     An actuation member  1024  may extend distally from actuator  1014 , and may be coupled to distal end  1004  of needle  1009 . In one aspect, medical device  1000  includes only one actuation member, although other suitable actuation members could also be used. A spring  1032  may be disposed between stop  1020  of handle  1006 , and actuator  1014 . Spring  1032  is longitudinally compressed in the flexible configuration of  FIG. 10 , and is longitudinally extended to a resting configuration when medical device  1000  is in the rigid configuration of  FIG. 11 . 
     The movement of actuator  1014  and actuating member  1024  relative to body  1012  may be configured to transition medical device  1000  between the loose and rigid configurations. As set forth above, spring  1032  is longitudinally-compressed in the loose configuration. Actuating member  1024  is slack in the same configuration of medical device  1000 . When medical device  1000  is in the loose configuration of  FIG. 10 , a distally-directed force on actuator  1014  may be released, causing actuator  1014  to move proximally, allowing spring  1032  to extend into the resting position shown in  FIG. 11 . The proximal movement of actuator  1014  may increase tension in actuating member  1024  until actuating member  1024  becomes taut. This may cause the distal end of the needle  1009 , which is coupled to actuating member  1024 , to flex away from a longitudinal axis of medical device  1000 , and forcing closure of notches  1026 . The flexed configuration of needle  1009  may include a radius of curvature such that needle  109  resembles an arc. Medical device  100  may be transitioned back to the loose configuration by reapplying a distally directed force acting on actuator  1014 , compressing spring  1032 . This compression causes actuation member  1024  to move from the taut configuration to the slack configuration, causing notches  1026  to reappear, and reverting needle  1009  to the loose configuration of  FIG. 10 . 
     An operator may be required to maintain a distally-directed force on actuator  1014  in order to navigate needle  1009  through tortuous anatomy. Then, when needle  1009  is advanced outside of an introducing device, e.g., an endoscope, the operator may release the distally-directed force, and perform a biopsy procedure with the needle  1009 . 
     A medical device  1200  is shown in  FIG. 12 . Medical device  1200  is reciprocally movable between a first, flexible configuration (not shown), and a second, rigid configuration shown in  FIG. 12 . Medical device  1200  may extend from a proximal end  1202  toward a distal end  1204 . Medical device  1200  may include a handle  1206  at proximal end  1202 , a needle  1209  extending distally from handle  1206 , and an actuating member  1224 . Needle  1209  and actuating member  1224  may be substantially similar to needle  1009  and actuating member  1024  described with reference to  FIGS. 10 and 11 . 
     Handle  1206  may include a body  1212 , and an actuator  1214  that is slidable or otherwise movable relative to body  1212 . Body  1212  may include a lumen  1216 . A stop  1220  may extend into lumen  1216  from an inner circumferential surface of body  1212 . Actuator  1214  may be disposed distally of stop  1220 . 
     Actuation member  1224  may extend distally from actuator  1214 , and may be coupled to distal end  1204  of needle  1209 . A spring  1232  may be disposed between stop  1220  of handle  1206 , and a proximally-facing surface of actuator  1214 . Spring  1232  is longitudinally-extended in a resting position while medical device  1200  is in the flexible configuration (not shown), and is longitudinally-compressed in the rigid configuration of  FIG. 12 . 
     The movement of actuator  1214  and actuating member  1224  relative to body  1212  may be configured to transition medical device  1200  between the loose and rigid configurations. As set forth above, spring  1232  is longitudinally-extended in the loose configuration of medical device  1200 . When medical device  1200  is in the loose configuration, a proximally-directed force may be applied to actuator  1214 , causing actuator  1214  to move proximally, compressing spring  1232 . The proximal movement of actuator  1214  may cause the distal end of the needle  1209 , which is coupled to actuating member  1224 , to flex away from a longitudinal axis of medical device  1200 , and to force closure of the notches of needle  1209 . Needle  1209  may have a radius of curvature and may otherwise resemble an arc in this configuration. Thus, in response to the proximally directed force, medical device  1200  may move from the loose configuration, to the rigid configuration of  FIG. 12  by compressing spring  1232 . In some aspects, the proximally-directed force must be maintained to keep medical device  1200  in the rigid configuration. Medical device  1200  may be transitioned back to the loose configuration by releasing the proximally directed force acting on actuation member  1224  and actuator  1214 , allowing spring  1232  to expand longitudinally, causing the notches to reappear, and reverting needle  1209  to a loose configuration similar to the configuration shown in  FIG. 10 . 
     Medical device  1200  may be configured such that no additional force needs to be applied in order to navigate medical device  1200  through tortuous anatomy (other than the force required to move the medical device  1200  itself). Instead, once medical device  1200  is positioned adjacent a working site, a proximally-directed force may be applied to actuator  1214  to transition needle  1209  to the rigid configuration suitable for collecting biopsy samples. 
     A needle  1300  is shown in  FIG. 13 . Needle  1300  may extend from a proximal end  1302  toward a distal end  1304 . Needle  1300  may be substantially similar to any of the needles described herein, and also may include a distal point  1308  that is splayed radially outward from a distal tip  1306  of needle  1300 . The distal point  1308  may be a distalmost point of a path travelling along an entirety of needle  1300 . Distal point  1308  also may be a permanent portion of needle  1300  that is present in every configuration of the needle  1300 , as opposed to being present in only some configurations of needle  1300 . Thus, as needle  1300  travels along tortuous anatomy, curves, expands, or compresses, distal point  1308  may remain unchanged relative to a remainder of distal tip  1306 . Distal point  1308  may be the first portion of needle  1300  that pierces through tissue, and its radially outward orientation may cause a remainder of needle  1300  to follow a path  1311  through tissue that is offset from a central longitudinal axis  1310  of needle  1300 . That is, after distal point  1308  pierces through tissue and in response to a force directed along central longitudinal axis  1310 , needle  1300  may flex and follow path  1311  through tissue. 
     A scope  1400  is shown in  FIG. 14 . Scope  1400  may include a flexible shaft  1401  that extends from a proximal end  1402  to a distal end  1404 . Shaft  1401  may be configured to navigate tortuous anatomy within a patient. In some aspects, shaft  1401  may be uniformly flexible, or may include portions having varied flexibility. For aspect, distal end  1404  of shaft  1401  may be more flexible than proximal end  1402 . Scope  1400  may be any suitable medical scope, such as, e.g., an endoscope, a ureteroscope, a colonoscope, a hysteroscope, a bronchoscope, or a cystoscope. Shaft  1401  may be directly inserted into the body of a patient or may be extended over a guidewire using one or more lumens. Shaft  1401  also may be inserted into a laparoscopic port, a single incision port, an over-tube, a bouché, or any other suitable member. 
     Shaft  1401  may include a single lumen  1412  (e.g., only one lumen), although any other suitable number of lumens may be utilized. For aspect, an additional lumen  1415  may be configured to accommodate any suitable visual device. For aspect, a lumen  1415  may be configured to contain a visual device allowing a user to view an area adjacent to distal end  1404  of scope  1400 , including areas distal to distal end  1404 . The visual device may be built into scope  1400 , and include one or more of a light source, lens, fiber optics, and/or any suitable electronic vision components known in the art, etc., to view a work site within a patient&#39;s body lumen. In another aspect, a separate imaging device may be utilized. It is also contemplated further additional lumens (not shown) may be utilized for any other suitable purpose, such as, e.g., irrigation, aspiration, suction, delivery of additional tools, delivery of therapeutics, or as a guiding lumen which is used to guide shaft  1401  over a guidewire. 
     A tool  1414  may extend through lumen  1412 . Tool  1414  may include a cutting knife, a cutting wire, an injection needle, a needle knife, a snare, or other therapeutic or diagnostic devices, including any of the devices set forth herein. 
     A deflecting tool  1416  may be coupled to an outer surface of shaft  1401 . Deflecting tool  1416  may be substantially similar to any of the medical devices and/or needles described herein that are movable between a loose configuration and a rigid configuration. However, in some aspects, deflecting tool  1416  may have a blunt, atraumatic distal tip, instead of a sharp distal tip. The atraumatic tip may be configured to reduce or prevent damage to tissue that is contacted by the atraumatic tip. For aspect, the atraumatic tip may include a polymer material having a relatively small durometer or hardness. In other aspects, the atraumatic tip may include a ball tip or any other features, such as rounded edges, configured to reduce damage to tissue that contacts the tip. 
     Deflecting tool  1416  may be used to deflect tissue or other bodily structures while disposed in the rigid configuration, and may be used to hold and position tissue prior to and during manipulation or resection. For aspect, deflecting tool  1416  may be placed adjacent to or in contact with tissue to be resected or biopsied, and transitioned to the rigid state to push or deflect the tissue to an optimal cutting position. In some aspects, the deflecting tool can be used to make target tissue taut to facilitate cutting of the target tissue. 
     A scope  1500  is shown in  FIG. 15  that is substantially similar to scope  1400 , except that scope  1500  may include at least one additional lumen  1513 . A deflecting tool  1516  may extend through additional lumen  1513 . The deflecting tool  1516  may be substantially similar to deflecting tool  1416  and may be used in a substantially similar manner. The opening of lumen  1513  at the distal end of scope  1500  may lie in a plane, and deflecting tool  1516  may be configured to extend distally away from the distal end  1504  along a trajectory that is substantially perpendicular to the plane of the opening. 
     Articulating needles of the present disclosure may include only two configurations in some aspects. For aspect, the two configurations of a needle may be offset from one another by 45 degrees. In other aspects, articulating needles may be continuously variable with the use of back tension springs or incompletely cut links, which would allow the needles to spring back to an initial shape when no tension is applied by the user. 
     One or more portions of the disclosed medical devices and needles may include a lubricious coating to reduce friction between the medical devices or needles, and contacted tissue. Any suitable lubricious coating may be utilized, including water soluble, biocompatible compounds that impart lubricity to the surface of otherwise non-lubricious materials. One class of hydrophilic coatings includes hydrogels, which swell in an aqueous environment, and are capable of manifesting lubricity while in a wet or hydrated state. When hydrated, these substances have low frictional forces in humoral fluids including saliva, digestive fluids and blood, as well as in saline solution and water. Hydrogels include polyethylene oxides, optionally linked to the substrate surface by urethane or ureido linkages or interpolymerized with poly(meth)acrylate polymers or copolymers, copolymers of maleic anhydride, (meth)acryl amide polymers and copolymers, (meth)acrylic acid copolymers, polyurethanes, poly(vinyl pyrrolidone) and blends or interpolymers with polyurethanes, polysaccharides, and mixtures thereof. 
     Medical devices of the present disclosure also may be coated with an antibacterial covering to inhibit bacterial growth on its surface. The antibiotic coating may contain an inorganic antibiotic agent, disposed in a polymeric matrix that adheres the antibiotic agent to a device surface. Further, a drug-releasing coating may also be applied to the device surface, assisting in delivery of drugs to the biopsy site. In another alternative, imaging markers may be applied to various medical devices, to assist in locating the medical devices within the body. Radiopaque, sonoreflective, and/or any other suitable markers may be employed. 
     A method  1600  is shown in  FIG. 16 . The method  1600  may begin at step  1602 , where an endoscope or other suitable member may be inserted into the body and navigated to a target region. For aspect, an endoscope may be inserted into the body through a natural anatomic opening, such as, for aspect, the mouth, anus, nose, or vagina. Alternatively, the endoscope may be inserted into the body through an incision. An operator may navigate the endoscope from the point of insertion to a target region (e.g., work site) within the body by traversing a body channel, such as, e.g., the biliary system. In other aspects, the work site may include a lymph node or any other tissue that may be potentially cancerous and has been identified for biopsy and further study. 
     Once a distal end of the endoscope is adjacent or otherwise proximate to the target region, a needle according to any of the aspects of the present disclosure may be inserted through a port of the endoscope while in a loose configuration at step  1604 . The floppy needle then may be pushed toward the distal end of the endoscope. Once the needle exits the distal end of the endoscope, the method may proceed to step  1606 , where the needle may be transitioned from the loose configuration to a rigid configuration. Once the needle is in the rigid configuration, it may be extended further distally from the scope to pierce tissue and collect a sample at step  1608 . Step  1608  may be repeated numerous times around and/or through the same target area (e.g., an eccentric lesion) in order to acquire tissue samples from multiple portions of the target area (e.g., fanning). The multiple samples may be taken while keeping the introducing endoscope in a fixed position, which may result in a significant reduction in procedure time. 
     A method  1700  is shown in  FIG. 17 . Step  1702  may be substantially similar to step  1602  of method  1600 , except that scope  1400  or  1500  may be used instead of the endoscope described with reference to method  1600 . Once scope  1400  or  1500  is positioned adjacent to a target or otherwise proximate to the target region, deflection tool  1416  or  1516  may be transitioned from a loose configuration to a rigid configuration to prepare tissue for manipulation, cutting, or resection at step  1704 . Once the tissue is ready, the subsequent procedure (e.g., cutting) may be performed at step  1706  by tool  1414 . 
     Those skilled in the art will understand that the medical devices set out above can be implemented in any suitable body lumen (e.g., blood vessels, the biliary tract, urological tract, gastrointestinal lumens, and the like) without departing from the scope of the disclosure as defined by the claims. In particular, constructional details, including manufacturing techniques and materials, are well within the understanding of those of skill in the art and have not been set out in any detail here. These and other modifications and variations are well within the scope of the present disclosure and can be envisioned and implemented by those of skill in the art. 
     Other aspects of the present disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the aspects disclosed herein. It is intended that the specification and aspects be considered as implementations only, and departures in form and detail may be made without departing from the scope and spirit of the present disclosure as defined by the following claims.