Abstract:
A removable attachment for selectively connecting coaxial medical instruments comprises a first instrument having a proximal end, a distal end and a lumen extending therethrough. The first instrument comprises an arm extending from a fulcrum located on the first instrument and a second instrument movably placed within the lumen of the first instrument, the second instrument comprising a hub at a proximal end thereof. The hub comprises a distal edge to engage a proximal end of the first instrument. The arm pivots around the fulcrum and is configured to selectively engage the hub to provide a removable locking connection between the first and second instruments.

Description:
PRIORITY CLAIM 
       [0001]    This application claims the priority to the U.S. Provisional Application Ser. No. 61/140,775, entitled “Fine Needle Aspiration Handle Attachment” filed on Dec. 24, 2008. The specification of the above-identified application is incorporated herewith by reference. 
     
    
     BACKGROUND 
       [0002]    Biopsies may be performed with fine needle aspiration (“FNA”) devices to obtain small samples of tissue for cytology studies, endoscopy or oncology (e,g., for biopsy of the breast or liver). Biopsy needles enable the capture of histological samples from a predetermined depth within a living body and are generally controlled by mechanisms selectively attached to proximal ends thereof which remain external to the body during use. Presently available gripping handles require that an endoscope be threaded thereonto. However, as the endoscope is threaded onto the gripping handle, the entire handle and, consequently, the entire length of the FNA device is rotated winding up the FNA device which, as noted above, may be 250 cm or longer. This winding up of the FNA device creates resistance to the threading motion and, as soon as the handle is released, the FNA device begins to unwind, unthreading the endoscope from the handle. 
       SUMMARY OF THE INVENTION 
       [0003]    The present invention is directed to a removable attachment for selectively connecting coaxial medical instruments comprising a first instrument having a proximal end, a distal end and a lumen extending therethrough, the first instrument comprising an arm extending from a fulcrum located on the first instrument and a second instrument movably placed within the lumen of the first instrument, the second instrument comprising a hub at a proximal end thereof, the hub comprising a distal edge to engage a proximal end of the first instrument, wherein the arm pivots around the fulcrum and is configured to selectively engage the hub to provide a removable locking connection between the first and second instruments. 
         [0004]    The present invention is further directed to a device for facilitating insertion of a flexible instrument into a living body comprising an elongated body extending longitudinally from a proximal end to a distal end which, when the flexible instrument is in an operative position within the body, remains outside the body accessible to a user, the body defining a lumen extending therethrough and a gripping mechanism pivotally mounted to the elongated body for movement between a gripping configuration in which an abutting surface thereof extends over a distal end of the elongated body from a radially outer edge thereof a predetermined distance toward a longitudinal axis thereof to engage a corresponding abutting surface of a flexible instrument inserted through the lumen, and an open configuration in which the abutting surface is pivoted radially beyond the outer edge of the elongated body. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  shows a first side view of a device according to a first exemplary embodiment of the present invention in a closed configuration; 
           [0006]      FIG. 2  shows a second side view of the device of  FIG. 1  in a partially open configuration; 
           [0007]      FIG. 3  shows a third side view of the device of  FIG. 1  in an open configuration; 
           [0008]      FIG. 4  shows a second embodiment of the present invention in a closed configuration; 
           [0009]      FIG. 5  shows a first view of a third embodiment of the present invention in an open configuration; and 
           [0010]      FIG. 6  shows a second view of the device of  FIG. 5  in a closed configuration. 
       
    
    
     DETAILED DESCRIPTION 
       [0011]    The present invention may be further understood with reference to the following description and the appended drawings, wherein like elements are referred to with the same reference numerals. The present invention relates to devices for performing biopsy procedures using fine-needle aspiration (“FNA”) devices. In particular, embodiments of the present invention may be employed with FNA devices for treatment of the gastrointestinal tract where a length of the FNA device exceeds 250 cm. However, it is noted that embodiments of the present invention may be applied to any FNA procedure performed at any depth in the body. 
         [0012]    An attachment mechanism  100  according to the present invention provides an apparatus by which an endoscope or other device to be inserted into a living body to perform an FNA procedure may be secured to a gripping handle. The gripping handle may be manipulated by a physician or other user of the device to control the FNA device in situ. The attachment mechanism  100  bypasses the prior threading process by providing a lever  102  which may be selectively actuated to operate gripping arms thereof to engage the FNA device. 
         [0013]    As shown in  FIGS. 1-3 , the attachment mechanism  100  comprises the lever  102  mounted on a distal portion of a handle body  104  which defines a lumen  101  through which an endoscope is inserted. It is noted that the use of the term distal herein refers to a direction away from a user (i.e., toward a patient on which it is being used) while the term proximal refers to a direction approaching a user of the device. The proximal portion of the endoscope and the entire attachment mechanism  100  remain external to the patient as the distal portion of the endoscope is inserted through the handle to a target site within the patient&#39;s body. Exemplary materials for the present invention may comprise any of a variety of suitable plastics, metals or combinations thereof as known to those of skill in the art so long as the materials are biocompatible and exhibit the required mechanical properties (e.g., a desired degree of rigidity, etc.). The handle body  104  and a proximal portion of an endoscope  120  inserted therethrough remain external to the body when in an operative configuration. In use, the handle body  104  provides a hand hold for gripping and manipulation of the device via which a user may apply torque and otherwise manually control the movement of the FNA device attached thereto. 
         [0014]    The lever  102  is pivotally attached to the handle body  104  via pins  106  located on opposite lateral sides thereof which are received in corresponding bores  107  formed in the handle body  104 . The pins  106  extend radially inward a predetermined distance (e.g., a distance equivalent to a depth of the bores  107 ). The lever  102  may then be slidably received over the handle body  104  until the pins  106  engage the bores  107 , locking the lever  102  in place. The pins  106  may be substantially cylindrical and correspond in shape and size to bores  107  so that the lever  102  may pivot about an axis defined by the bores  107  when locked to the handle body  104 . The pivoting motion of the lever  102  allows a user to selectively move the lever  102  between open and closed configurations, as described in greater detail below. In an alternate embodiment, the lever  102  may be pivotally attached to the handle body  104  by pins integrally formed with the lever  102  and projecting radially inward therefrom at the same spots shown for the pins  106 . A portion of the lever  102  including the pins would be formed as a collar flexed radially outward and slid over the handle body  104  until the pins reach the bores  107  and are pushed thereinto by the bias of the lever  102  and maintained in this position by the bias of the lever  102 . It is further noted that the pins  106  do not extend through the handle body  104  as the endoscope must be slid therethrough. The pins  106  extend only into the wall of the handle body  104  and do not penetrate the lumen  101 . As would be understood by those skilled in the art, the collar (not shown) may be secured to the handle body  104  via insert molding, compression fitting, thermal bonding or another known means. 
         [0015]    The lever  102  extends proximally and distally from the pins  106  along opposite sides of the handle body  104  (i.e., the portion of the lever  102  extending proximally from the pins  106  is on a side of a longitudinal axis of the handle body  104  opposite the portion extending distally therefrom). Specifically, a proximal portion  110  of the lever  102  extends to a tab  108  along a first longitudinal length of the handle body  104 . The tab  108  facilitates grasping of the lever  102  by a user to move the lever  102  from a closed configuration shown in  FIG. 1  to an open configuration shown in  FIG. 3 . Actuation may comprise one of application of a radially outwardly directed force to the tab  108  (e.g., by sliding a finger between the lever  102  and the handle body  104 ). A distal portion  112  of the lever  102  extends along a second longitudinal length of the handle body  104  to a tine  114  projecting radially inward from a distal end of the lever  102 . The tine  114  according to this embodiment is formed as a part of a circle which, when in the closed configuration, is centered at the longitudinal axis of the handle body  104 . A proximally facing portion of the tine  114  is tapered. In a preferred embodiment, the proximal portion  110  forms an angle of less than 180° with respect to the distal portion  112 , thus permitting the lever  102  to apply a radially constrictive force on a female luer  118  of the endoscope  120  when assuming a closed configuration, as described in greater detail below. 
         [0016]    A distal end of the handle body  104  comprises a male luer  116  comprising an opening to house the female luer  118  of the endoscope  120 , as those skilled in the art will understand. The female luer  118  may be formed to fit within the male luer  116  with a fluid-tight friction fit and may be prevented from advancing into the male luer  116  beyond a predetermined distance. For example, the male luer  116  may have a depth selected to prevent the female luer  118  from being inserted thereinto beyond a predetermined depth. When in the closed configuration of  FIG. 1 , the tine  114  extends over and engages a luer thread (not shown) formed on the female luer  118 . Engagement with at least one of the luer threads locks the female luer  118  in place against the male luer  116 . Thus, when in the closed configuration, the tine  114  prevents the endoscope  120  from separating from the attachment mechanism  100 . It will be appreciated by those skilled in the art that the pins  106  engage the handle body  104  with friction fit sufficient to prevent pivotal movement of the lever  102  when not moved to the open configuration by the user.  FIG. 2  shows the lever  102  as it is being rotated out of engagement with the female luer  11   8  of the endoscope  120 . Once the tine  114  has been moved radially out of contact with the endoscope  120 , the endoscope  120  may be manually withdrawn therefrom. Arms  122  of the endoscope  120  are provided to aid in the manual manipulation of the endoscope  120 . 
         [0017]    The endoscope  120  may further be provided with a means to prevent unwanted rotation thereof once locked to the attachment mechanism  100 . For example, the endoscope  120  may be provided with at least one boss (not shown) at a proximal end of the female luer  118 . The tine  114  may comprise a protrusion (not shown) sized and located to engage a lateral side of the at least one boss (not shown). Specifically, when the tine  114  is in a closed configuration, the protrusion (not shown) is located adjacent to the boss (not shown) preventing rotation of the endoscope  120  in a direction approaching the protrusion. A second boss (not shown) and a second protrusion (not shown) may then be employed to prevent rotation of the endoscope  120  in the opposite second direction, as those skilled in the art will understand. 
         [0018]      FIG. 4  depicts a locking mechanism  150  according to a second embodiment of the present invention, wherein like elements are indicated with like reference numerals. The locking mechanism  150  is formed substantially similar to the locking mechanism  100  of  FIGS. 1-3  with the exception of a lever  152  formed thereon. The lever  152  is movable from an open configuration (shown in phantom) wherein a tine  114  of a distal portion  154  is radially separated from the female luer  118  of the endoscope  120  and a closed configuration wherein the proximal portion  158  is substantially perpendicular to the handle body  104  and the distal portion  154  lies flush therewith, the tine  114  lying in a contacting configuration with the female luer  118  of the endoscope  120 . 
         [0019]    Specifically, the distal portion  154  of the lever  152  is configured to be substantially perpendicular to the proximal portion  158 . A joint  162  between the distal portion  154  and the proximal portion  158  is configured to receive the pins  106  on opposite lateral sides thereof. The pins  106  are received in corresponding bores  107  formed in the handle body  104  and permit rotation of the lever  152  in directions A and B. The proximal portion  158  of the lever extends along a second longitudinal length of the handle body  104  in a direction substantially opposite to a first longitudinal length housing the distal portion  154 . The proximal portion  158  comprises a gripping tab  160  formed at a proximal end thereof, wherein a curvature of the proximal portion  158  and the gripping tab  160  substantially conforms to a curvature of a contacting portion of the handle body  104 , as shown in phantom in  FIG. 4 . Furthermore, in order to permit the proximal portion  158  to lie flush against the handle body  104  in the open configuration, the proximal portion  158  may be formed with a longitudinal slot (not shown) running along a longitudinal centerline thereof, the slot defining lateral sides configured to contact the handle body  104 , as those skilled in the art will understand. 
         [0020]    As shown in  FIGS. 5-6 , a locking mechanism  200  according to a third embodiment of the invention comprises a collet  202  on a distal end of a handle body  204 . The collet  202  comprises two arms  208  extending distally from the handle body  204 , each arm  208  further comprising an abutment  210  facing radially inward at a distal end thereof. The abutments  210  are sized and shaped to engage a shoulder of luer threads  206  of an endoscope  220  to which the handle body  204  is to be connected. As indicated in the figure, the endoscope  220  comprises one or more helical or circular luer threads  206  on a proximal end thereof. 
         [0021]    The collet  202  is movable between a retracted position housed within a handle luer  216 , and an actuated position in which the collet  202  is extended distally from distal end of the handle body  204 . Proximal and distal movement of the handle body  204  relative to the collet  202  may be performed via actuation of a lever (not shown) on a proximal portion of the handle body  204 , as those skilled in the art will understand. For example, the lever may be held in position to maintain the position of the collet  202  substantially constant as the handle body  204  is moved proximally to move the collet  202  out of the handle body  204 . The arms  208  of the collet  202  are biased toward a bent configuration in which the distal ends thereof are spread radially from the one another and are radially separated from the surface of the handle luer  216 . Thus, as the collet  202  is moved distally to the actuated position, the handle body  204  no longer constrains the arms  208  and they splay radially outward due to the bias. Then, the lever may be held in position as the handle body  204  is moved distally over the arms  208  drawing them radially inward to engage the luer  218  of the endoscope  220 . Movement of the handle body  204  distally over the collet  202  can proceed until a post  214  engages a distal face  222  of the handle body  204 . This prevents the collet  202  from being drawn into the handle body  204  beyond a predetermined distance. In this manner, both a length of the arms  208  and the abutments  210  apply a retaining force on the endoscope  220  to lock a configuration thereof. The abutments  210  extend radially inward by a distance selected to engage the luer  218  in a manner sufficient to maintain the endoscope  204  connected to the handle body  204  until manually disengaged by the user. As would be understood by those skilled in the art, the user may disengage the arms  208  from the endoscope by holding the lever in position to maintain the position of the collet  202  substantially constant as the handle body  204  is moved proximally, extending the arms  208  from the handle body  204  and returning the collet  202  to the open position. 
         [0022]    It will be apparent to those skilled in the art that various modifications may be made in the present invention, without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover modifications and variations of this invention provided that they come within the scope of the appended claims and their equivalents.