Abstract:
An implantable access device for intravenous delivery and/or withdrawal of fluids is described herein. The access device includes a septum which is movably supported within a housing of the access device from a retracted, low profile position to an extended, high profile position to facilitate easy identification of the location of the septum by medical personnel.

Description:
[0001]    This application claims priority from U.S. Provisional Application Ser. No. 60/995,749, which was filed on Sep. 28, 2007 and is incorporated herein in its entirety by reference. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present disclosure relates to implantable access devices for intravenous delivery and/or withdrawal of fluids. More particularly, the present disclosure relates to an implantable access device having a septum which can be moved to a high profile position to assist medical personnel in locating the septum. 
         [0004]    2. Background of Related Art 
         [0005]    Implantable access devices for intravenous fluid delivery and/or withdrawal are well known in the medical arts. Typically, such devices are implanted under the skin to allow for intermittent access to a selected vascular structure, such as an artery or vein. These devices are most commonly used in patients who require repeated injections on a daily basis and/or require repeated injections with large diameter needles, such as during hemodialysis procedures where relatively large needles and/or catheters in the range of 14 gauge or higher are required. 
         [0006]    One problem associated with such access devices is that once the access device has been surgically implanted beneath the skin, the septum or pierceable membrane of the access device through which the injection occurs, is not visible. Thus, it may require one or more attempts by medical personnel to locate the septum of the access device. 
         [0007]    Accordingly, a continuing need exists in the medical arts for an access device which includes a septum which can be easily identified by medical personnel prior to a medical procedure. 
       SUMMARY 
       [0008]    An implantable access device is provided which includes a housing defining a cavity an an outlet channel, the cavity being in fluid communication with the outlet channel. A septum encloses an upper end of the cavity. The septum is movably supported in relation to the housing and is movable from a first, lower-profile position to a second, higher-profile position located externally of the cavity. The access device also includes an upper collar and a lower collar. The upper collar is positioned within the cavity and defines a throughbore. The septum is supported on the upper collar and seals one end of the throughbore of the upper collar. In one embodiment, the upper collar is movable within the cavity from a first position to a second position to move the septum from the retracted position to the extended position. 
         [0009]    4. The implantable access device according to Claim  3 , further including a biasing member positioned to urge the upper collar from the first position to the second position. 
         [0010]    5. The implantable access device according to Claim  4 , further including a lower collar rotatably supported within the cavity of the housing. 
         [0011]    6. The implantable access device according to Claim  5 , wherein a lower end of the upper collar is positioned within the cavity to abut an upper end of the lower collar. 
         [0012]    7. The implantable access device according to Claim  6 , wherein the lower end of the upper collar includes at least one angled protrusion and the upper end of the lower collar includes at least one rib, the at least one angled protrusion engaging the at least one rib to apply torque to the lower collar. 
         [0013]    8. The implantable access device according to Claim  7 , further including a cam assembly defining at least one retaining member and at least one channel, wherein the rib of the lower collar and at least one guide rib of the upper collar are slidable within the at least one channel. 
         [0014]    9. The implantable access device according to Claim  8 , wherein the cam assembly is fixedly secured within the housing such that the upper collar and the lower collar are rotatably fixed when the rib of the lower collar and the guide rib of the upper collar are positioned within the at least one channel. 
         [0015]    10. The implantable access device according to Claim  9 , wherein when the upper collar is in the first position, the rib of the lower collar is pushed from the at least one channel and rotated by the angled protrusion, such that the rib engages the retaining member and the lower collar is retained in a lower portion of the cavity to retain the upper collar in the first position and retain the septum in the retracted position. 
         [0016]    11. The implantable access device according to Claim  10 , wherein the at least one retaining member includes an angled recess and a stop member, the rib engaging the stop member when the septum is retained in the retracted position. 
         [0017]    12. The implantable access device according to Claim  11 , wherein when the septum is in the retracted position, the upper collar can be pressed downwardly to urge the lower collar downwardly within the cavity to disengage the at least one rib of the lower collar from the stop member and allow the lower collar to rotate to realign the at least one rib with the at least one channel such that the biasing member moves the septum to the extended position. 
         [0018]    13. The implantable access device according to Claim  1 , further including an annular sleeve having a first end connected to a bottom surface of the septum and a second end connected to the housing, the sleeve defining a sealed flow path between the septum and the outlet channel. 
         [0019]    14. The implantable access device according to Claim  13 , wherein the annular sleeve is in the form of a bellows-like member. 
         [0020]    15. An implantable access device according to Claim  1 , further including a biasing member positioned to urge the septum towards the extended position. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0021]    Various embodiments of the presently disclosed vascular access device and method of use are disclosed herein with reference to the drawings, wherein: 
           [0022]      FIG. 1  is a side perspective cross-sectional view of one embodiment of the presently disclosed access device shown in phantom implanted in a patient with the septum in a retracted position; 
           [0023]      FIG. 2  is a side perspective cross-sectional view of the access device shown in  FIG. 1  in phantom implanted in a patient with the septum in an extended position; 
           [0024]      FIG. 3  is a perspective, partial cross-sectional, exploded view of the access device shown in  FIG. 1 ; 
           [0025]      FIG. 4  is a perspective, partial cross-sectional view of the access device shown in  FIG. 1  with the upper collar in an extended position and the septum and sleeve removed; 
           [0026]      FIG. 5  is a perspective, partial cross-sectional view of the access device shown in  FIG. 4  with the upper collar in an extended position and the lower collar, biasing member, sleeve and septum removed from the device; 
           [0027]      FIG. 6  is a cross-sectional view of the access device shown in  FIG. 1  with the septum in an extended position; 
           [0028]      FIG. 7  is a partial cross-sectional view of the access device shown in  FIG. 6  as the septum is moved towards the retracted position; 
           [0029]      FIG. 8  is a side, partial cross-sectional view of the housing and lower collar of the access device shown in  FIG. 7  with parts separated; 
           [0030]      FIG. 9  is a side, partial cross-sectional view of the access device shown in  FIG. 7  as the lower collar moves into engagement with the retaining members; 
           [0031]      FIG. 10  is a side, cross-sectional view of the access device shown in  FIG. 7  with the septum in the retracted position; 
           [0032]      FIG. 11  is a side, partial cross-sectional view of the access device shown in  FIG. 7  as the upper collar is pressed downwardly to return the septum to the extended position; and 
           [0033]      FIG. 12  is a side, partial cross-sectional view of the housing and lower collar of the access device shown in  FIG. 11  with parts separated. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0034]    Embodiments of the presently disclosed implantable access device will now be described in detail with reference to the drawings wherein like reference numerals designate identical or corresponding elements in each of the several views. 
         [0035]      FIGS. 1-6  illustrate one embodiment of the presently disclosed access device shown generally as  10 . Access device  10  includes a housing  12  having an upper body portion  14 , a lower body portion  16  ( FIG. 6 ) an upper collar  18 , a lower collar  20 , a biasing member  24  and a septum  26 . Upper body portion  14  of housing  12  defines a cavity  28  dimensioned to receive the various components of device  10  as will be described in further detail below. A cam assembly  22  is formed along the inner wall  15  of upper body portion  14  of housing  12 . Lower body portion  16  defines an outlet channel  30  ( FIG. 6 ) that fluidly communicates a bottom of cavity  28  with a catheter  32 . 
         [0036]    Referring to  FIGS. 3-6 , upper collar  18  has a substantially cylindrical body  34  which defines a throughbore  34   a.  Alternatively, it is envisioned that upper collar  18  may have a variety of different configurations. Septum  26  is supported in an upper end of throughbore  34   a  using any known fastening technique, e.g., adhesives, welding, press-fitting, etc. See  FIG. 6 . A proximal end of upper collar  18  includes a series of angled protrusions  36  and a plurality of guide ribs  37 . Angled protrusions  36  can have a substantially triangular shape and are configured and dimensioned to interact with lower collar  20  to effect rotation of lower collar  20  within housing  12  as will be described in further detail below. Guide ribs  37  rotatably fix upper collar  18  within cavity  28  of housing  12  and define the uppermost or extended position of upper collar  18  as will also be described in further detail below. 
         [0037]    Lower collar  20  is substantially cylindrical and defines a throughbore  38 . A series of longitudinal ribs  40  are positioned about the external surface of collar  20 . An upper end  40   a  of each of ribs  40  is positioned to engage angled projections  36  of upper collar  18  to effect rotation of lower collar  20  as will be described in detail below. Upper end  40   a  of ribs  40  may be tapered or angled. 
         [0038]    Referring to  FIGS. 3 and 5 , cam assembly  22  includes a series of retaining members  44  positioned annularly about cavity  28  of upper body portion  14 . Each of retaining members  44  is separated from adjacent retaining members  44  by channels  46 . Each retaining member  44  includes a lower end which defines an angled, recessed surface  50 , a vertical stop portion  52  and an angled or sloped guide surface  53 . In an alternative embodiment, the cam assembly may be provided on an annular cam member  22  which is separate from housing  12  and is fixedly positioned within housing  12  and dimensioned to be positioned about a lower end of upper collar  18  and lower collar  20 . When upper collar  18  and lower collar  20  are assembled within cavity  28  of upper body portion  14  of housing  12 , guide ribs  37  of upper collar  18  and longitudinal ribs  40  of lower collar  20  are slidably positioned within channels  46  of cam assembly  22 . As illustrated in  FIG. 3 , an upper end of each of channels  46  is closed and defines an abutment surface  55  which engages guide ribs  37  to define the extended position of upper collar  18  and prevent separation of collar  18  from housing  12 . 
         [0039]    Referring to  FIGS. 3-6 , biasing member  24 , which may be a coil spring, is positioned within cavity  28  between lower body portion  16  ( FIG. 6 ) and a lower end of lower collar  20  such that lower collar  20  is urged upwardly towards upper collar  18 . When ribs  40  of lower collar  20  are aligned with channels  46  of cam assembly  22 , biasing member  24  urges lower collar  20  upwardly into a lower end of upper collar  18  to move the upper collar  18  to its extended or high profile position. See  FIGS. 4 and 5 . As discussed above, when upper collar  18  is in its extended position, abutment surface  55  is engaged with a top surface of guide ribs  37 . It is also noted that when the upper collar  18  is in its extended position, the upper end  40   a  of rib  40  engages the lower end of angled protrusions  36  of upper collar  18 . 
         [0040]    Referring to  FIGS. 7-10 , when upper collar  18  is pressed downwardly in the direction indicated by arrow “A” in  FIG. 7 , lower collar  20  is urged downwardly against biasing member  24  and angled protrusions  36  press against the top surface of ribs  40  to torque lower collar  20 . When ribs  40  of lower collar  20  exit channels  46  of cam assembly  22 , the torque applied by angled protrusions  36  on the upper end of ribs  40  rotates lower collar  20  in the direction indicated by arrow “B” in  FIG. 8  causing the upper end  40   a  of ribs  40  to move into recessed surfaces  50  of retaining members  44  and abut against stop portion  52  of retaining members  44 . When this occurs, lower collar  20  and, thus, upper collar  18  are retained in a retracted or low profile position. See  FIGS. 9 and 10 . 
         [0041]    Referring to  FIGS. 4 ,  5 ,  11  and  12 , when upper collar  18  is in its retracted position and it is pressed downwardly in the direction indicated by arrows “C” in  FIG. 11 , the upper end  40   a  of rib  40  is moved downwardly and passes under stop portion  52  of cam assembly  22  ( FIG. 12 ) and lower collar  18  rotates in the direction of arrow “D” in  FIG. 12  as discussed above. When lower collar  20  rotates, ribs  40  once again align with channels  46  of cam assembly  22  and biasing member  24  urges lower collar  20  upwardly to move upper collar  18  and septum  26  to the extended position. It is noted that sloped guide surfaces  53  of retaining members  44  in combination with biasing member  24  guides ribs  40  into channels  46 . 
         [0042]    Referring to  FIGS. 3 and 6  and as discussed above, septum  26  is secured to an underside of upper collar  18 . In one embodiment, a sleeve  60  has a first end  60   a  secured to a bottom surface of septum  26  and a second end  60   b  secured to lower body portion  16 . Sleeve  60  provides a sealed passage  80  from septum  26  to outlet channel  30  of lower body portion  16 . Sleeve  60  has an extendable configuration to facilitate movement of upper collar  18  to its extended position. In one embodiment, sleeve  60  has a flexible bellows-like construction. It is envisioned that other extendable sleeve configurations may be used. It is also envisioned that upper body portion  14  of housing  12  may have an o-ring or other sealing means to prevent the entry of substances found beneath the surface of the skin into cavity  28  along a path between upper collar  18  and a side wall of cavity  28 . 
         [0043]    In use, implantable access device  10  is implanted beneath the skin ( FIG. 1 ) in a known manner with upper collar  18  in its retracted position. When medical personnel would like to inject or withdraw a fluid from device  10 , the general area of skin near access device  10  can be pressed downwardly to press upper collar  18  into housing  12 . As discussed above, when this occurs, rib  40  ( FIG. 3 ) of lower collar  20  moves under stop portion  52  of cam assembly  22  and lower collar  20  is rotated to align ribs  40  of lower collar  20  with channels  46  of cam assembly  22 . When this occurs, lower collar  20  and upper collar  18  are urged upwardly by biasing member  24  such that upper collar  18  and septum  26  move to the extended, high profile position. In this position, a top surface of upper collar  18  will press against an undersurface of the skin such that the location of septum  26  will be apparent to medical personnel. See  FIG. 2 . After a medical procedure has been performed, upper collar  18  can be returned to the retracted position in the manner discussed above by pressing downwardly on upper collar  18 . Alternatively, it is envisioned that upper collar  18  may be pressed downwardly during a medical procedure, such as while inserting a needle through septum  26 , to return the upper collar to the retracted position. 
         [0044]    It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplifications of preferred embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.