Abstract:
An implantable port comprises a port body forming a fluid reservoir and a septum sealing a proximal end of the reservoir in combination with a clicker member biased toward a first configuration, the clicker member being deformable via mechanical force applied thereto and configured so that, when subject to a force of at least a predetermined magnitude, the clicker member rapidly deforms away from the first configuration to a second configuration to provide one of an aural and tactile feedback to the user.

Description:
PRIORITY CLAIM 
       [0001]    The present application claims priority to U.S. Provisional Patent Application Ser. No. 61/027,217 filed on Feb. 8, 2008 entitled “Implantable Fluid Transfer Access Port” to Paul DiCarlo, Stephanie Dubay and Jeff Gray. The entire disclosure of the above-identified application is expressly incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    Repeated penetrations of internal body structures by needles for fluid transfer can have significant consequences in the long term including degradation of the organ or vessel which is repeatedly accessed. For this reason, procedures requiring such repeated access are often facilitated by implanting a port into which needles are inserted. The port is fluidly coupled to the structure to be accessed, providing a path for fluid transfer which reduces trauma to the body structure (e.g., vessels such as veins, arteries, etc.). Prior to the insertion of a needle, the port must be located, for example, by palpation of the skin in the vicinity of the port and then the location of a needle penetrable septum of the port must be accurately located. When one or more ports have been implanted in a patient, an X-ray or a CT-scan may be necessary to identify a particular port suited to the procedure currently being performed. 
       SUMMARY OF THE INVENTION 
       [0003]    The present invention relates to a implantable port, comprising a port body forming a fluid reservoir and a septum sealing a proximal end of the reservoir in combination with a clicker member biased toward a first configuration, the clicker member being deformable via mechanical force applied thereto and configured so that, when subject to a force of at least a predetermined magnitude, the clicker member rapidly deforms away from the first configuration to a second configuration to provide one of an aural and tactile feedback to the user. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]    The present invention is illustrated in the accompanying drawings in which: 
           [0005]      FIG. 1  shows a cross-sectional side view of a vascular access port according to an embodiment of the invention in a first state; 
           [0006]      FIG. 2  shows a partially cross-sectional side view of the port of  FIG. 1  in a second state; 
           [0007]      FIG. 3  shows a proximal view of the port of  FIG. 1 ; 
           [0008]      FIG. 4  shows a proximal view of a port according to a further embodiment of the invention; and 
           [0009]      FIG. 5  shows a cross-sectional view of a port according to a still further embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0010]    The present invention, which may be further understood with reference to the following description and the appended drawings, relates to implanted fluid transfer port and a means for identifying a type of such a port after implantation within a body. It is noted that although exemplary embodiments of the present invention are described below with respect to percutaneous procedures, the description is not meant to limit the application of the invention, which may be employed in a plurality of medicinal and non-medicinal fields. 
         [0011]    Presently available vascular access ports are identified by, for example, unique shapes identifiable through palpation. However, the intervening skin and tissue can make accurate differentiation between the shapes of the various ports and proper identification of these ports difficult. 
         [0012]    A device according to the present invention employs a port comprising a clicking mechanism which serves to identify a type of and location of the port. As shown in  FIG. 1 , an implanted vascular access port  100  according to an exemplary embodiment of the present invention comprises a septum  110  to seal a fluid chamber  113  formed within the port  100 . The septum  110  may be comprised of a penetrable, self-sealing material such as silicone, as known in the art, to seal the fluid chamber  113  and prevent the passage of fluids between the port  100  and surrounding tissues. When implanted in the body, the septum  110  of the port  100  is preferably positioned to face the skin to facilitate insertion of a needle therethrough. The port  100  may further include a clicker actuator ring  120  extending around at least a portion of a periphery of the port  100 . As further shown in the top-view of  FIG. 3 , the clicker actuator ring  120  may, for example, be formed as a ring encircling a proximal end of the port  100  radially outside the septum  110  with a clicker actuator member  121  extending through the port  100  toward a distal end thereof. A distal end of the clicker actuator member  121  contacts an outer periphery of a clicker member  130  which extends across the port  100  distal of a distal end of the reservoir  113 . In another embodiment of the present invention, the clicker actuator member  121  and the clicker member  130  may be integrally formed or formed of separate elements bonded to one another or simply in contact with one another. The clicker member  130  is preferably formed as a thin sheet of material (e.g., a disk) biased toward a first position (e.g., concave proximally) in which it contacts a distal surface  132  of the port  100  only at a fulcrum point or fulcrmn path  134  with a space between the periphery of the clicker member  130  and the distal surface  132 . Thus, moving the clicker actuator ring  120  distally relative to the port  100  pushes the clicker actuator member  121  against the periphery of the clicker member  130 , thus bending the clicker member  130  about the fulcrum point or path  134  to produce an audible click. 
         [0013]    For example, the clicker member  130  of the port  100  may be formed as a substantially parabolical disk with a thickness of the disk decreasing toward a central portion thereof. The clicker member  130  may be formed of a flexible material having a memory capability allowing the clicker member  130  to flex with the application of a force thereupon and return to its original position upon the removal of the force. Examples of suitable materials having memory capability include ELGILOY™, 304 spring stainless steel, a polymer or polymer alloy and other suitable materials as known in the art. Furthermore, the clicker member  130  may be formed in any suitable shape fitting within the confines of the port  100 , such as a triangle, square, etc. so long as mechanical contact with the clicker actuator member  121  is maintained. 
         [0014]    In accordance with an exemplary method of the present invention, a user wishing to make an injection, palpates a region of the skin under which one or more ports  100  are implanted and locates the clicker actuator ring  120 . The person then holds the port  100  steady and applies a force to the clicker actuator ring  120  in the direction X shown in  FIG. 2  to force the clicker actuator member  121  distally as indicated by the arrow Y. This distal movement generates a click via the resulting deformation of the clicker member  130  in the direction of the arrow Z from a concave shape (viewed from the proximal side) to a convex shape. The clicking capability or lack thereof gives the user information as to the identity of the port  100  being palpated. For example, the user may know that, of the two ports implanted in a patient, only the power injection suitable port  100  has clicking capability. Upon release of the palpation force, the clicker member  130  snaps back to its resting concave position which may also generate a clicking sound as well as a short reverberating pulse that may be felt by the user of the port  100 . 
         [0015]    In yet another embodiment of the present invention, the port  100  may comprise any plurality of units, such as an actuator comprising two or more pieces engaging one another. It is noted that although any plurality of units may be employed in this embodiment, a minimum of the three core units is required, including the septum  110 , the clicker actuator ring  120  and the clicker member  130 . 
         [0016]    As shown in  FIG. 4 , a port  300  according to a further embodiment of the present invention comprises a shape memory ring  320  that may be embedded in a radially outer rim of a septum  310 . When a compressive force is applied to the septum  310  (e.g., radially compressive in the direction of arrows A) via palpation as described above, the shape memory ring generates an audible or tactile feedback response that identifies the port  300  (e.g., the type of port and/or the anatomical structure to which it is coupled). As would be understood by those skilled in the art, the ring  320  will resist compression until a sufficient force is applied to overcome the bias of the shape memory material at which point, the portions of the ring  320  being compressed will give way and rapidly switch from convex to concave producing the tactile and/or audible feedback. After this compressive force has been removed, the shape memory properties of the ring  320  restore the ring  320  to its original shape. In another embodiment, the shape memory ring may be embedded in the external body portion of the port  100 . The shape memory ring may be covered by a polymer sealant applied thereupon during the manufacturing process. Similarly, when a compressive force is applied to the shape memory ring, an audible or tactile response may be elicited, indicating a location of the port  100  in the body. 
         [0017]    As shown in  FIG. 5 , a port  200  according to yet another embodiment of the invention provides audible feedback when manipulated to facilitate identification of the port  200 . The port  200  comprises a septum  210  which covers an opening  211  located thereupon. Like the septum  110  of the embodiment of  FIGS. 1-3 , the septum  210  is formed of a material which reseals itself after penetration by a needle to maintain the port  200  sealed between injections. A needle or other device inserted through the septum  210  of port  200  is received into a reservoir  225 , which is fluidly connected to, for example, a vein, duct, artery, vessel or organ in a body. Furthermore, a distal portion of the port  200  comprises a plate  230  composed, for example, as a plate shaped in a plane substantially transverse to a proximal-distal axis of the port  200  to correspond to a shape of the port  200  (e.g., circular) made up of, for example, titanium or any other suitable material. The plate  230  curves away from a distal surface of the port  200  to form a convex surface (as viewed proximally) with a portion of the plate  230  approaching a center thereof projecting proximally into the reservoir  225  while a perimeter portion of the plate  230  is attached to a distal end of the port  200  by any suitable means known in the art such as, for example, welding, adhesive, fasteners, interference fit, etc. 
         [0018]    Accordingly, when a needle, such as needle  240  is inserted through the septum  210 , a distal end of the needle  240  contacts the plate  230 . The application of force driving the needle  240  further distally after this contact deflects the surface of the plate  230  with the resulting deformation of the plate  230  generating a clicking sound. The user may then use the presence or absence of this clicking capability to determine whether this is the desired port before operating a syringe or other device attached to the needle  240  to inject fluids to or withdraw fluids from the port  200 . As would be understood by those skilled in the art, the plate  230  is preferably formed to automatically retract to the original convex position upon the removal of the force from the needle  240  so that, at the next injection, the same clicking sound may be generated. 
         [0019]    As would be understood by those skilled in the art, the plate  230  may comprise any suitable shape (e.g., non-circular shapes or any other shapes corresponding to the shape of the port) and may be formed of any of a variety of suitable materials. For example, the plate  230  may be triangular, rectangular, etc. with the plate  230  placed over any portion of the distal end of the port  200  suited to achieve the desired deformation of the plate  230  upon palpation. 
         [0020]    Those skilled in the art will understand that the described exemplary embodiments of the present invention may be altered without departing from the spirit or scope of the invention. Thus, it is to be understood that these embodiments have been described in an exemplary manner and are not intended to limit the scope of the invention which is intended to cover all modifications and variations of this invention that come within the scope of the appended claims and their equivalents. The specifications are, therefore, to be regarded in an illustrative rather than a restrictive sense.