Abstract:
A system for delivery of therapeutic and/or diagnostic agents into a living body includes a port assembly having a cannula extending from the mounting side, a port opening away from the mounting side and a resilient barrier between the port and the cannula. An access hub includes a connector positionable at the port for opening the resilient barrier. The access hub is movable in the port assembly, is engaged therewith through a resilient ring coupling and forms a seal with the resilient barrier, reducing the amount of volume to be primed. Inserters, both disposable and reusable, include the cannula insertion member as part of the assembly. A spring loaded port driver is operatively mounted within the housing with movement controlled by a latch. The driver includes a seat for receipt of a port assembly. The cannula insertion member is nonremovably fixed in a socket in the port driver in the disposable assembly. In the reusable inserter, the cannula insertion member is slidably mounted within a socket associated with the latch. Slidable movement is limited by locking shoulders. The socket is split and may be splayed to release the cannula insertion member following use.

Description:
REFERENCE TO RELATED CASES  
       [0001]     This application is a continuation of PCT/US04/14207, filed May 7, 2004, which has a priority date of May 9, 2003 based on U.S. patent application Ser. No. 10/435,620 filed on May 9, 2003, the disclosures of which are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The field of the present invention is devices for the delivery or placement of therapeutic or diagnostic agents into a living body.  
         [0003]     Some medical procedures employ the infusion of therapeutic agents into living bodies over periods of time, making a syringe inconvenient and/or inappropriate. Such procedures have been used for the infusion of insulin, for example. In other cases, monitoring of internal body conditions with small sensors or other devices also makes syringes and like devices inappropriate for continuing access to subcutaneous tissue. To provide access in either circumstance, ports have been devised which provide support for a flexible cannula implanted in the body. Ports typically provide a housing which has a mounting side that is held by tape, dressings or direct adhesive against the body. A flexible cannula extends from the housing into the body.  
         [0004]     Ports used for infusion may be employed in combination with a delivery tube extending to the housing of the port and in communication with the cannula as a complete infusion set. The delivery tube of such an infusion set is in communication with the flexible cannula through an infusion fluid chamber in the port to deliver therapeutic agents. Diagnostic agents such as biosensors may be delivered in like manner.  
         [0005]     To place such ports or infusion sets including such ports, insertion sets have been used. An insertion set typically includes the port and necessarily includes a rigid sharp such as a needle which is placed through the flexible cannula for insertion into the body. The needle typically extends through a resilient barrier such as a resealable resilient mass, through a chamber and then axially through the cannula. Once the cannula has been positioned in the body, the port is positioned and the needle can be withdrawn. The resealing of the mass as the needle is withdrawn prevents fluid from leaking from the port while remaining in position at the site. Once the port has been placed with the flexible cannula extending into the body, the agent or agents can be delivered.  
         [0006]     A first type of insertion set includes an infusion set having the port and a delivery tube in communication with the cannula. The insertion set needle accesses the housing through a different path than the delivery tube. The seal is typically bypassed by the delivery tube in this instance. Alternatively, the insertion set is used with a port rather than a complete infusion set. The delivery tube is placed after insertion of the port to complete an infusion set. The same path is used for the insertion needle as part of the insertion set as is used for communicating the tube of the infusion set with the cannula. In this latter case, the delivery tube is associated with a hub which includes a member able to pierce a resealable resilient mass for communication between the delivery tube and the cannula once the insertion set has been disassembled through retraction of the needle.  
         [0007]     Mechanisms referred to as inserters have been devised to rapidly insert the needle and cannula into the body at the site. For the infusion of insulin in particular, diabetics self medicate. Consequently, they, a family member or other care provider places the port for infusion. This can be emotionally and physically difficult when repeated infusions are required over long periods of time. Inserters alleviate this burden somewhat by making the placement of the needle automatic and quick. Further, pressure by the inserter about the targeted site reduces the sensation of pain.  
         [0008]     Inserters typically include a housing with a driver slidable in the housing. The driver includes a socket to receive the insertion set. A spring is operatively placed between the housing and the driver to advance rapidly an insertion set positioned in the socket. A latch then controls the advancement of the driver. One complete system including an infusion port, an insertion set having the infusion port and an insertion needle, and an inserter is illustrated in U.S. Pat. No. 6,293,925.  
       SUMMARY OF THE INVENTION  
       [0009]     The present invention is directed to a system for the delivery of therapeutic and/or diagnostic agents and components thereof. An inserter for a port assembly includes a housing assembly and a port driver with a spring operatively between the two. The housing assembly includes a housing having a bore and a latch. The port driver includes a seat for receiving a port assembly. The port driver also includes a socket. A cannula insertion member is positioned in the socket and is inseparable from the socket. With the insertion member inseparable from the socket, the inserter becomes disposable. Potentially, the port assembly and an access hub could be included with the inserter as a disposable system. The inserter can come fully prepared and sterile with seals at either end of the bore. The housing assembly can also serve as a package serving to appropriately discard the inserter with the needle covered.  
         [0010]     Therefore, it is a principal object of the present invention to provide a new inserter for a port assembly. Other and further objects and advantages well appear hereinafter. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a plan view of a port assembly.  
         [0012]      FIG. 2  is a side view of the port assembly of  FIG. 1 .  
         [0013]      FIG. 3  is a cross-sectional view of the port assembly of  FIG. 1  taken through the axis thereof along line  3 - 3  of  FIG. 2 .  
         [0014]      FIG. 4  is a cross-sectional view of the port assembly taken at 90° to the cross-sectional view of  FIG. 3 .  
         [0015]      FIG. 5  is a detail view as seen in  FIG. 3 .  
         [0016]      FIG. 6  is a perspective view of a resilient barrier.  
         [0017]      FIG. 7  is a cross-sectional view of the resilient barrier.  
         [0018]      FIG. 8  is a perspective view of a second port assembly.  
         [0019]      FIG. 9  is a cross-sectional view of the port assembly of  FIG. 8  taken through the axis.  
         [0020]      FIG. 10  is a cross-sectional view of a third port assembly also taken through the axis of the assembly.  
         [0021]      FIG. 11  is a perspective view of a port inserter.  
         [0022]      FIG. 12  is a cross-sectional view of the port inserter of  FIG. 11  taken through the axis of the port inserter.  
         [0023]      FIG. 13  is a cross-sectional view of the port inserter of  FIG. 12  with the inserter discharged and closed, the view being at 90° to  FIG. 12 .  
         [0024]      FIG. 14  is a cross-sectional view of a second port inserter taken through the axis of the inserter.  
         [0025]      FIG. 15  is a plan view of a third port inserter.  
         [0026]      FIG. 16  is a cross-sectional view taken along an axis of the port inserter of  FIG. 15 .  
         [0027]      FIG. 17  is a cross-sectional view taken along an axis of the port inserter of  FIG. 15  at 90° to the view of  FIG. 16 .  
         [0028]      FIG. 18  is a cross-sectional view taken along an axis of a fourth port inserter.  
         [0029]      FIG. 19  is a cross-sectional view taken along an axis of the port inserter of  FIG. 18  at 90° to the view of  FIG. 18 .  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0030]     Turning in detail to the drawings,  FIGS. 1 through 7  illustrate a first port assembly, generally designated  20 . The port assembly  20  includes a base  22  which is shown to be frustoconical. The base may alternatively be cylindrical. Other shapes, of course, can also be employed. The base includes a mounting side  24 . The mounting side may include adhesive for retention at a site on a living body. The adhesive is preferably nondrying and may or may not include a coated paper cover to be removed prior to use. A port  26  is arranged in the base  22  to be open to the other side of the base from the mounting side  24 . In this embodiment, the port opens into a cavity  28  defined by a cannula mounting element  30  and a retainer element  32  which are sonically welded, press fit or cemented into the main part of the base  22 .  
         [0031]     A cannula  34  extends from the base  22 . In this embodiment, the cannula extends perpendicular to the mounting side  24 . Other angles might be appropriately employed. The cannula mounting element  30  provides a passage  36  into which the cannula  34  is positioned. The cannula  34  has a mounting flange  38  to retain the cannula  34  from being drawn through the passage  36 . The cannula  34  may be retained in the cannula mounting element  30  and a seal formed with the passage  36  through the use of adhesive, sonic welding where the materials are compatible, a press fit, or sealing elements. In the preferred embodiment, the cannula mounting element  30  insures retention of the cannula  34  by ultrasonically swaging the body of the element  30  to draw material from that element  30  over the flange  38 , as best seen in  FIG. 5 .  
         [0032]     The port assembly  20  further includes a resilient barrier  42 . The resilient barrier  42  is preferably an elastomer. It is positioned in the cavity  28  and overlies the cannula  34 . The resilient barrier  42  controls fluid communication from the port  26  to the cannula  34 .  
         [0033]     The resilient barrier  42  is illustrated in this embodiment to be a valve. The valve  42  is defined by a circular elastomeric septum  44 . The septum  44  includes a slit  46  therethrough. The slit  46  is cut so that the valve remains closed when in the unstressed state. A frustoconical concavity  48  provides relief for flexure of the septum  44  downwardly to open the slit  46 . As can best be seen in  FIG. 6 , the septum  44  includes shaped protrusions  50  to influence the distortion of the septum  44  with pressure from above. The septum  44  further includes circular beads  52  and  54 . These beads provide seals for sealing contact with components on either side of the septum  44 . Thus, the circular bead  54  provides sealing contact with the cannula mounting element  30  about the cannula  34  and also about the concavity  48 . Thus, the resilient barrier  42  controls communication from the port  26  to the cannula  34  through pressure on the upper side thereof.  
         [0034]     An access hub, generally designated  56 , includes a hub  58 . A connector  60  extends from the main body of the hub  58 . A tube  62  extends laterally from the main body of the hub  58 . A fitting  64  is located at the end of the tube  62  for receipt of an infusion tube (not shown). Other fittings may be employed to rigidly engage such tubing or other components. A passage  66  extends through the fitting  64 , the tube  62  and the connector  60  to provide flow communication through the access hub  56 . The tube  62  has a length of reduced outside diameter to receive a tab  68 . The tab  68  is pivotally mounted about the area of reduced cross section of the tube  62 . The tab  68  includes a split hub  70  for forced mounting on the tube  62 . Ribs  72  on the tab  68  provide increased purchase. The tab  68  has a first position as illustrated in  FIGS. 1 and 2 . In a second position, the tab may be pivoted to extend more aligned with the longitudinal direction of the connector  60  for easy gripping between thumb and forefinger.  
         [0035]     The access hub  56  is constructed such that the connector  60  can be positioned through the port  26  into the cavity  28  and fully against the resilient barrier  42 , as seen in each of the relevant Figures. The bottom of the connector  60  includes a surface able to press against the shaped protrusions  50  on the opposed surface of the circular elastomeric septum  44 . The protrusions  50  might alternatively or additionally be found on the end of the connector  60  but it is preferred that they be located on the septum  44  such that rotation of the access hub  56  relative to the port assembly  20  will not impact on the communication through the slit  46 . The connector includes an annular surface  74  which, in cross section as illustrated in  FIG. 5 , is shown to provide a segment of a circle. The curved portion of the surface  74  facing toward the distal end of the connector  60  aids in the location of the access hub  56  into the port assembly  20 . The more proximal portion of the annular surface  74  cooperates with a radially resilient bearing ring  76  located within the cavity  28 . Together the annular surface  74  and the radially resilient bearing ring  76  define a coupling between the port assembly  20  and the access hub  56 . The ring  76  is preferably split to create adequate radial resilience. The ring  76  includes an inner concave track  78  meeting with the annular surface  74 . The resilience in the ring  76  and the shape of the concave track  78  cause the ring  76  to draw the connector  60  further into the cavity  28  as the ring  76  attempts to contract. This bias forces the flat end of the connector  60  against the circular bead  54  to result in sealing contact therebetween. The placement of the connector  60  is such that the circular bead  54  is located about the end of the passage  66 . The annular surface  74  is small enough to fit through the port  26  and to force open the ring  76 .  
         [0036]     The port assembly  20  and access hub  56  of this first embodiment provide for the placement of the port assembly  20  in the body prior to an assembly of the port assembly  20  and the access hub  56 . Once assembled, the connector  60  of the access hub  56  is biased against the septum  44 , resulting in the circular beads  52  and  54  sealing against the connector  60  and the cannula mount element  30 , respectively. The distal surface of the connector  60  forces the shaped protrusions  50  toward the cannula  34  to open the slit  46 . Once open, the slit  46  provides communication from the passage  66  to the cannula  34 . Further, the access hub  56  can be pivoted about the centerline of the connector  60 . When the access hub  56  is removed by extraction force transmitted by the tab  68 , the slit  46  returns to the closed position as the force acting upon the shaped protrusion  50  is removed.  
         [0037]     Another port assembly, generally designated  80 , is illustrated in  FIGS. 8 and 9 . This port assembly  80  exhibits a flat rather than frustoconical profile. A base  82  again provides a mounting side  84  which may include adhesive  86 . A cannula mounting element  88  is fixed in the base  82  and has a retainer element  90  thereabout which is also fixed in the base  82 . The cannula mounting element  88  retains a cannula  92  much as in the first embodiment. Further, a resilient barrier  94  defined by the circular elastomeric septum  44  as illustrated in  FIG. 6  of the first embodiment is held between the cannula mounting element  88  and the retainer element  90 . The retainer element  90  defines a port  96 . The retainer element  90  also defines a post about the port  96  including an annular surface  98 . The surface  98  defines a concave track about the post thus defined.  
         [0038]     An access hub generally designated  100 , can be assembled with the port assembly  80 . The access hub  100  includes a hub  102  having a hub circular periphery  104 . This periphery  104  includes cut-outs  106  diametrically opposed with undercut sides  108 . The cut-outs  106  expose the base  82  so that a pinching of the assembly with the thumb and forefinger will separate the access hub  100  from the port assembly  80 .  
         [0039]     The hub  102  provides a cylindrical cavity  110  which has one portion about the periphery thereof modified for the provision of a fitting  112 . The fitting  112  again provides for infusion tubing (not shown). An inclined asymmetry  114  at the fitting  112  insures that the infusion tubing is not pushed so far into the fitting  112  that a further passageway into the access hub  100  is closed off.  
         [0040]     An inner hub element  116  fits within the cylindrical cavity  110  and defines a connector  118  and a passage  120 . The passage  120  extends from the fitting  112  to through the connector  118 . The passage  120  is formed as a channel in the inner hub element  116  and closed by the hub  102 . Further, the passage  120  extends through the connector  118 . As with the prior embodiment, the connector  118  is insertable to the resilient barrier  94 , operating in the same way as the first embodiment in the influence on opening the valve mechanism associated therewith.  
         [0041]     A retainer  122  is fixed to the inner web element  116 . The retainer  122  is contemplated to extend fully about the inner cavity  124  defined within the inner hub element  116 . The inner hub element  116  and the retainer  122  capture a radially resilient bearing ring  126  within the inner cavity  124 . This bearing ring  126  is preferably split and includes a convex annular bead  128  which cooperates with the annular surface  98  to define a coupling between the port assembly  80  and the access hub  100 . Albeit the location of the elements are inverted, the ring  126  acts in a similar way to that of the first embodiment in that it is sized and arranged to force the connector  118  into sealing contact with the resilient barrier  94 . Again, one of the end surfaces of the connector  118  and the resilient barrier  94  includes shaped protrusions to cause opening of the valve upon placement of the connector  118  in the port  96 .  
         [0042]     A further port is illustrated in  FIG. 10 . The access hub  130  is identical to that of the embodiment of  FIGS. 8 and 9 . Further,  FIG. 8  applies equally to the embodiments of  FIG. 9  and  FIG. 10 . The port assembly  132  includes a base  134  which is defined by a cannula mounting element  136  and a disk  138  having a cylindrical flange about the outer periphery thereof. Together the mounting element  136  and disk  138  provide a flow area therebetween which is able to reach a plurality of cannulas  142  extending from the mounting surface  144 . These cannulas  142  are rigid but are contemplated to be very short so as to provide dispersed infusion into living tissue or multi-sensor diagnostic access. The cannulas are rigidly fixed within the cannula mounting element  136 . Further, the cannula mounting element  136  provides a broader opening which communicates with the flow area between the plate  136  and the disk  138  for adequate distribution of infusion fluids thereabout.  
         [0043]      FIGS. 11 through 19  provide inserter embodiments. These embodiments are shown to mate with the port assembly  20 . Through slight modification of the seat within which the port assembly is positioned, the embodiments of  FIGS. 8 through 10  might also be accommodated. The first two embodiments,  FIGS. 11 through 13  and  14  are advantageously configured for disposable use. The embodiment of  FIGS. 15 through 17  is most advantageously reusable. Finally, the embodiment of  FIGS. 18 and 19  is configured for reusable or disposable use.  
         [0044]     In the embodiment of  FIGS. 11 through 13 , the inserter, generally designated  148 , is shown to include a housing assembly including a housing  150 . The housing  150  is conveniently cylindrical with a bore  152  and outwardly extending flanges  154  to define circular attachment surfaces at either end of the bore  152 . First and second closures  156  and  158  can be retained on the flanges  154 . These closures  156  and  158  include a tab  160  such that they are conveniently removably mounted across the bore  152  with adhesive. The closures  156  and  158  are preferably peal-off sheets commonly employed for sterile closures.  
         [0045]     The housing  150  further includes a mount  162  extending across the bore  152  and integrally formed with the housing  150 . The mount  162  is in the form of a plate perpendicular to the axis of the bore  152 . A central hole  164  is provided through the mount  162  to receive a latch discussed below. Two holes  166  elongate in cross section extend to either side of the central hole  164 . These holes are parallel and are located symmetrically about the center axis of the housing. Certain additional holes  168  are provided through the mount  162  for molding purposes.  
         [0046]     The housing  150  further includes stops  170  extending inwardly in the bore  152  and conveniently being diametrically opposed to one another. The holes  168  for molding purposes are aligned with the stops  170  such that molding of the stops  170  is facilitated. Indexing tabs  172  are also diametrically placed to one side of the mount  162  and are also formed as part of the inner wall of the housing  150 . On the other side of the mount  162 , a key  174  extends into the bore  152  and from the mount  162 .  
         [0047]     A latch  176  is positioned to one side of the mount  162 . The latch includes a plate  178  extending substantially across the bore  152  of the housing  150 . Additionally, the latch  176  includes upwardly extending walls  180  forming segments of a cylinder. One of these segments of the walls  180  includes a keyway  182  which receives the key  174 . The keyway  182  has a substantial portion having a first height to receive the key  174  with the latch  176  axially positioned as shown in  FIG. 12 . At one point, the keyway  182  is of increased depth parallel to the centerline of the housing  150  which allows the latch  176  to move toward the mount  162 . The walls  180  have three gaps  184  therebetween. One of the walls  180  also includes an undercut section  186 .  
         [0048]     Hooks  188  extend in the opposite direction of the walls  180  from the plate  178 . These hooks  188  include outwardly extending barbs  190  which extend through the central hole  164  in the mount  162 . The barbs  190  have inclined surfaces  192  such that they can be forced into the central hole  164  with the hooks  188  exhibiting some resilience. The barbs  190  on the hooks  188  are spaced such that once inserted through the central hole  164 , they will engage the rim of the hole  164  regardless of the angular orientation such that the latch  176  is permanently captured by the mount  162 .  
         [0049]     Setoffs  194  extend in the same direction from the plate  178  as the hooks  188 . These setoffs  194  are straight and parallel to one another and equally displaced from the axis of the housing. The setoffs  194  match the parallel holes  166  so that the latch  176  may be forced closer to the mount  162 . However, the hooks  188  also each have an inclined surface facing outwardly which inhibits substantial movement of the latch  176  toward the mount  162  from the position a shown in  FIG. 12 . In position for use, the latch  176  is oriented such that the standoffs  194  are not aligned with the parallel holes  166  such that the latch  176  is held axially within the bore  152  of the housing  150 . During assembly of the inserter might the latch be angularly rotated to match the setoffs  194  with the parallel holes  166  to insure that assembly can be accomplished.  
         [0050]     A cover  198  is arranged with the latch  176 . The cover also includes a plate  200  which generally lies against the plate  178  of the latch  176 . A cylindrical wall  202  extends upwardly from the plate  200 . This wall  202  includes three blocks  204  which extend radially outwardly from the wall  202 . These blocks  204  engage the gaps  184  in the upwardly extending walls  180  of the latch  176 . Consequently, rotation of the cover  198  will result in rotation of the latch  176  with the two components in mating relationship.  
         [0051]     The cover also includes two fingers  206  diametrically opposed and spaced in cutout portions of the cylindrical wall  202 . One of these fingers  206  includes a rounded circumferentially extending bar  208  which engages the undercut section  186  in one of the upwardly extending wall segments  180 . The bar  208  provides some retention of the cover  198  but allows it to be removable with a small amount of force. The two opposed fingers  206  are slightly shorter than the full extent of the upstanding wall  202  and have inclined surfaces  207 . The fingers  206  are somewhat resilient and can move radially inwardly because of the cuts to either side of the fingers  206  in the cylindrical wall  202 .  
         [0052]     Centrally located in the plate  200 , an integral channel  210  extends across the cover  198 . This integral channel  210  forms a chamber  212  open toward the latch  176 .  
         [0053]     The structure of the cover  198  is such that it can be extracted from association with the latch  176  and pulled from the housing  150 . The cover  198  may then be turned over and forced into the other end of the housing  150  within the bore  152  as seen in  FIG. 13 . The fingers  206  resiliently ride over the diametrically opposed stops  170  across the inclined surfaces  207  and lock on the upper surface of the fingers  206 .  
         [0054]     The cylindrical wall  202  has an additional rim  214  about its circumference to fit closely within the bore  152  of the housing  150  in this position. As such, the lower end of the bore  152  is closed by the cover  198  after use. The upper end of the bore  152  remains substantially closed by the plate  178  of the latch  176 .  
         [0055]     A port driver, generally designated  216 , is slidably mounted within the bore  152  of the housing  150 . The port driver  216  includes a cylindrical outer wall  218  which slides within the bore  152 . The cylindrical outer wall  218  includes two gaps (not shown) diametrically opposed. These gaps mate with the indexing tabs  172  which extend from the mount  162 . These gaps also provide clearance to allow the port driver  216  to be mounted in the housing  150  across the stops  170 . The gaps extend fully through the port driver  216  and allow for air flow as the driver  216  moves through the housing  150 . A cylindrical inner wall  220  defines an annular spring cavity  221  for receiving a coil spring  222 . The cylindrical inner wall  220  includes an inwardly extending flange  224  which includes notches  226  diametrically opposed where there is no inwardly extending flange  224 . As such, the hooks  188  which extend through the central hole  164  further extend into the cylindrical inner wall  220  and engage the inwardly extending flange  224  unless aligned with the notches  226 .  
         [0056]     A plate  228  extends across the port driver  216  from which the cylindrical walls  218  and  220  extend to form the annular spring cavity  221 . This plate  228  provides a seat  230  which is shown in  FIGS. 12 and 13  to be conically formed to accommodate the first embodiment port assembly  20 . The seat  230  may easily be formed to accommodate the port assemblies  80  and  132 . In this disposable embodiment, the seat  230  does not in any way restrain the port assembly  20  from moving away from the seat  230 . The plate  228  does extend outwardly to the wall of the bore  152  such that the stops  170  will engage the plate  228  as it moves to the end of the housing  150 .  
         [0057]     The plate  228  includes a central portion  232  having holes  234  facilitating the molding process of the flanges  224 . The holes are directly aligned with the inwardly extending flange  224  to that end. A socket  236  is centrally located within the central portion  232 . This socket  236  is sized to receive a needle which may be forcefully fit within the socket  236  or permanently retained there by a bonding agent. In either circumstance, the socket is designed to rigidly and permanently fix a needle employed as a cannula insertion member.  
         [0058]     A cannula insertion member  238  in the form of a sharp needle is permanently affixed within the socket  236 . This needle  238  extends downwardly through the port assembly  20  and through the cannula  34  associated therewith. The cannula  34  is fit snugly about the needle  238  such that friction does exist between the cannula  34  and the needle  238 . The retention force thus provided maintains the port assembly  20  in place prior to application. The adhesive on the mounting side  24  is formulated to have a greater separation force than the retention force between the cannula  34  and the needle  238 . Further, the base  22  is sized to miss these stops  170 .  
         [0059]     In operation, the inserter  148  is assembled by pressing the latch  176  into position with the hooks  188  extending through the central hole  164 . The cover  198  is also positioned on the latch  176  and forced into place. The latch may be oriented such that the parallel setoffs  194  engage the parallel holes  166  so that the latch  176  may be forced further into the bore  152  to insure engagement with the port driver  216 . The coil spring  222  is placed between the mount  162  and the port driver  216  in the annular spring cavity  221 . The port driver is aligned with the housing  150  so that the gaps match up with the stops  170 . With the spring operatively positioned between the mount  162  and the port driver  216 , the port driver is forced upwardly and angularly displaced until the hooks  188  engage the inwardly extending flange  224 .  
         [0060]     The cannula insertion member  238  may originally be part of the inserter  148  by location in the socket  236  with a bonding agent or through forced interference fit. Alternatively, the cannula insertion member  238  may first be temporarily assembled with the port assembly  20  through the cannula  34  and then associated with the port driver  216  as the port assembly  20  is positioned. Ultimately, the cannula insertion member  238  becomes a fixed part of the port driver  216 .  
         [0061]     The closures  156  and  158  are then positioned and fixed on the ends of the housing  150  and the device sterilized. Depending on the method of sterilization, the device is sterilized after placement of the closures  156  and  158 .  
         [0062]     In use, the closures  156  and  158  are removed by pulling on the tabs  160 . The inserter  148  is then placed on the body site. The cover  198  is then rotated until the hooks  188  meet the notches  226  in the inwardly extending flange  224 , releasing the port driver  216 . The spring  222  propels the port driver  216  forwardly to the end of the housing  150  where it engages the stops  170 . The port assembly  20  is advanced with the port driver  216  until the adhesive contacts the surface of the body. In doing so, the cannula insertion member  238  is rapidly advanced into the body along with the supported cannula  34 . Once placed, the housing  150  is retracted from the body retaining the port driver  216  including the cannula insertion member  238 . The resilient barrier  42  prevents flow from the body through the cannula  34 . With the inserter  148  removed, the cover  198  is pulled from the end of the housing  150  and placed on the other end thereof to engage the fingers  206  with the stops  170 . The container  212  defined by the channel  210  receives the cannula insertion member  238  to cover the sharp and close the container.  
         [0063]     With the port assembly  20  in place and the inserter  148  removed, an access hub  56  can then be placed. As the connector  60  is inserted into the port  26  of the port assembly  20 , the end surface of the connector  60  extends against the shaped protrusions  50  of the resilient barrier  42 . The connector  60  does not extend through the slit  46  but opens the valve through its positioning in the cavity  28 . The coupling mechanism including the radially resilient bearing ring  76  and the annular surface  74  is engaged; and the connector  60  is pressed against the circular bead  52 . The access hub  56  is then movable in the port assembly  20  and can be pivoted to best advantage for the associated infusion tubing. Removal of the access hub  56 , in this embodiment by the tab  68 , will withdraw the connector  60  and allow the slit  46  to again close in the resilient barrier  42 .  
         [0064]     Turning to the port driver  240  illustrated in  FIG. 14 , the mechanism is substantially identical to that of the embodiment of  FIGS. 11 through 13 . However, the cover  242  is differently configured principally with a channel  244  having a container  212  which is askew to bend the cannula insertion member  246  to the side as the cover  242  is placed on the driver end of the housing  248 . Stops  250  again engage the cover  242  to hold it in place.  
         [0065]     Turning to the inserter embodiment of  FIGS. 15 through 17 , a reusable inserter, generally designated  252 , is disclosed. The inserter includes a housing  254  which is substantially identical to prior housings. The bore  258  includes a mount  260  extending across the housing  254  as previously described. However, the central hole  262  is increased in size for placement considerations.  
         [0066]     The port driver  264  includes a cylindrical outer wall  266  and a cylindrical inner wall  268  defining an annular spring cavity  270 . Inwardly extending flanges  272  are located at the end of the cylindrical inner wall  268  most adjacent the mount  260 . Again, notches  274  in the inwardly extending flanges  272  are arranged diametrically. A coil spring  276  is located within the annular spring cavity  270 . In this embodiment, the center area of the port driver  264  is open. An annular plate  278  closes the bottom of the annular spring cavity  270  and defines a seat for a port assembly  20 . In this embodiment, the base  282  of the port assembly  20  includes a circular channel  284 . The seat  280  of the annular plate  278  includes a retainer  286  in the form of a circular ring which engages a circular channel  284  with minimal release force generated by a minimal interference fit to retain the port assembly  20  in place prior to insertion.  
         [0067]     The cannula insertion member  288  includes a sharpened needle  290  and a needle hub  292 . The needle  290  is permanently retained within the needle hub  292 . The needle hub  292  includes an engagement shoulder  294  at its distal end and a plug  296  that fits within the port  298  of the port assembly  20 .  
         [0068]     A latch  300  is located to the other side of the mount  260  from the port driver  264 . The latch includes a plate  302  extending across the bore  258  of the housing  254 . A cylindrical wall  304  extends along the bore  258 . A keyway  306  is found in the cylindrical wall  304  to receive a key  307  associated with the housing  254 . Hooks  308  are provided as in prior embodiments but are spaced further apart to allow for the needle hub  292 .  
         [0069]     A socket  310  is centrally located in the plate  302  of the latch  300 . This socket  310  releaseably retains the needle hub  292  which is otherwise slidable within the socket  310 . The socket  310  includes a passageway  312  which is open at the end toward the port assembly seat  280 . A shoulder  314  is presented at the end of the passageway  312  to encounter and retain the engagement shoulder  294  of the needle hub  292 . The socket  310  is also split diametrically along its length to form two socket elements  316 . The length of the socket  310  is such that, in combination with the needle hub  292 , the engagement shoulder  294  and the shoulder  314  do not stop insertion of the cannula insertion member until the needle  290  has penetrated the body to the point that the associated cannula  34  will not extend beyond the needle  290 . The arrangement is designed to stop the cannula insertion member  288  before the port driver  264  has traveled fully to the stop  318  located in the bore  258  of the housing  254 .  
         [0070]     With the inserter  252  having been actuated by rotation of the latch  300  and the port assembly  20  placed, the inserter  252  can be withdrawn along with the cannula insertion member  288  as a component of the inserter  252 . Once withdrawn, the cannula insertion member  288  can be released from the reusable inserter  252 . The plate  302  defines a slightly flexible web across the bore  258  of the housing  254 . Two opposed levers  320  extend upwardly from that web  302 . These levers are aligned with the socket elements  316  defining the socket  310 . By pinching the levers  320  together, the socket elements  316  splay apart and release the needle hub  292 . A new cannula insertion member  288  can then be positioned in the inserter  252  by forcing it past the shoulder  314 . This may be accomplished with or without the port assembly  20 .  
         [0071]     With the reusable inserter  252 , the device may be prepared by positioning the cannula insertion member  288  in the port assembly  20 . The cannula insertion member  288  is then engaged with the socket  310  by forcing the needle hub  292  through the shoulder  314  on the socket elements  316 . These levers  320  may be pinched together to facilitate this assembly. The port assembly  20  is then forced against the port driver  264  to place the port assembly  20  in the seat  280  with the circular channel  284  and the circular ring  286  engaged with slight interference. Where the port assembly has exposed adhesive on the mounting side  322 , it is advantageous that the port driver  264  is forced into engagement with the latch  300  before placement of the port assembly  20 . Once prepared, the inserter  252  may be placed at the site and the levers  320  turned to rotate the latch  300  such that the hooks  308  meet the notches  274  and release the port driver  264 . The inserter  252  is then withdrawn, retaining the cannula insertion member  288  as part of the inserter assembly. The port assembly  20  remains at the site with the cannula  34  extending into the living body. An access hub  56  is then positioned with the connector  60  in the port  26 . Force is applied to engage the coupling between the two such that the access hub  56  is then movably retained within the port assembly  20 . The system is then ready for delivery of therapeutic agents or diagnostic agents through the cannula into the living tissue. The access hub  56  may be withdrawn through force exerted on the tab  68 , or by pinching the access hub in the second or third embodiments. The valve of the resilient barrier  42  responds appropriately by sealing the pathway when the access hub  56  is not in place and opening the pathway when it is.  
         [0072]     A further port inserter as illustrated in  FIGS. 18 and 19 , generally designated  324 , combines a number of features of the prior port inserters. The device may come fully sealed and sterile. Further, the port inserter  324  contemplates the intended release of the needle after use or the enclosure of that needle with the inserter for discard. A cylindrical housing  326 , as generally described in preceding embodiments, includes an extended length to accommodate closure elements  328  and  330 . A latch  332  operates identically to that in the prior embodiment of  FIGS. 15 through 17  and cooperates with a needle hub  334  and needle  336  in a like manner. The extended portion of the housing  326  encloses the levers of the latch  332  and receives a cover  338 . This cover is constructed so that it may be forced against the driver  340  from the bottom to enclose the needle  336  and lock the cover over the stops  342 . The driver  340  is the same as that of prior embodiments and is driven by a spring  344  in like manner. Likewise a port  20  also is as in prior embodiments.  
         [0073]     Thus, improved ports and inserters therefor have been described. While embodiments and applications of this invention have been shown and described, it would be apparent to those skilled in the art that many more modifications are possible without departing from the inventive concepts herein. The invention, therefore is not to be restricted except in the spirit of the appended claims.