Abstract:
A catheter assembly includes a catheter hub having an elastomeric septum that divides the catheter hub into a distal chamber and a proximal chamber. The septum also includes at least one slit that is closed and sealed when the septum is in an at-rest state. A septum activator is proximal the septum. When an external force pushes the activator against the septum, the activator deforms the septum so as to break the seal and create a flow path through the septum. A portion of the septum activator can be collapsible when subjected to the outside force. When the outside force is removed, the collapsible portion springs back to its at-rest shape, helping to pull the activator out of deforming engagement with the septum so that the septum can reseal. The activator can also be spring-biased away from engagement with the septum so that when the outside force is removed, the spring urges the activator out of engagement with the septum. With the activator removed, the septum slit can reseal.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The application claims priority to U.S. Provisional Application No. 61/911,904, which was filed on Dec. 4, 2013, the entirety of which is hereby incorporated by reference. 
     
    
     BACKGROUND 
       [0002]    The present disclosure relates to the field of infusion devices, and more particularly to peripheral intravenous (IV) catheters. 
         [0003]    A catheter assembly for an IV catheter generally includes a flexible catheter, or catheter tube, coupled to a distal end of a catheter adapter, which can include a catheter hub. The catheter adapter retains the catheter tube so that other components can interact with the catheter tube. In order to place the catheter tube in the patient&#39;s blood vessel, an introducer needle is coupled to the catheter adapter so that the needle extends through the catheter adapter and catheter tube, with the sharp distal tip of the needle positioned just beyond the distal end of the catheter tube. The clinician uses the introducer needle to penetrate the patient&#39;s tissue and place the distal end of the catheter tube in a blood vessel. 
         [0004]    Once the needle tip and the catheter tube are in the vessel, the clinician typically uses blood flashback to confirm that placement is correct. For example, when the needle tip and/or the catheter tube is properly placed in the vasculature of the patient, blood from the vessel may flow through the needle and/or the catheter tube into the catheter adapter. When the clinician sees the blood in the catheter adapter, the clinician knows that the distal tip of the needle and/or the distal end of the catheter tube is in place in the blood vessel. Once it is verified that the catheter is correctly placed in the blood vessel, the introducer needle is removed. 
         [0005]    During blood flashback, blood may accumulate in the catheter tube and catheter adapter. A valve such as an elastomeric septum in the catheter adapter contains the blood in a distal chamber of the catheter adapter. It can be desired to selectively open the septum to, for example, obtain a blood sample or to deliver IV fluids to the patient. Typically a septum activator is arranged proximal the septum. When the septum activator is forced into the septum, the septum is deformed and opened, creating a flow path for collection of a blood sample or delivery of IV fluids. 
         [0006]    In some instances it is desirable to have a reusable septum and septum activator so that the septum activator can be disengaged from the septum, and the septum will again seal, but forcing the septum activator into the septum at a later time will again break the seal and create a fluid flow path. 
       SUMMARY 
       [0007]    Accordingly, there is a need in the art for a catheter adapter having a septum or valve and an associated septum activator that accommodate repeated opening and resealing of the septum. 
         [0008]    In accordance with a preferred embodiment, the present disclosure provides a catheter assembly, comprising a catheter adapter defining an internal space. A septum within the internal space divides the internal space into a distal chamber and a proximal chamber. A septum activator has a compressible portion that is configured to be compressed from an at rest configuration to a compressed configuration when a coupler contacts and applies a force to a proximal end of the septum activator so as to urge the septum activator into the septum so as to deform the septum. When the coupler is removed from contact with the septum activator, the compressible portion elastically expands to the at rest configuration so as to generate a return force urging the septum activator proximally. 
         [0009]    In some such embodiments, the septum activator can have a plurality of elongate, spaced apart legs. For example, the septum activator can have a pair of, three, or more spaced apart legs that are configured to deflect when the coupler applies the force to the septum. Also, in some embodiments, the spaced apart legs can extend a majority of the length of the septum activator. 
         [0010]    Another embodiment can comprise a method in which attaching a coupler to a catheter adapter applies a force to the septum activator and both elastically compresses a compressible portion of septum activator and forces the septum activator into the septum so as to deform the septum. Removing the coupler frees the septum activator to elastically return to its non-compressed state, generating a return force urging the septum activator proximally relative to the septum. 
         [0011]    In accordance with another embodiment, a catheter assembly comprises a catheter adapter defining an internal space. A septum activator within the internal space has a proximal end and is movable between a proximal at rest position and a distal actuated position. A stationary arm extending from an inner wall of the catheter adapter is adjacent the septum activator. A movable member is configured to move with the septum activator within the catheter adapter internal space. A spring is interposed between the stationary arm and a portion of the movable member. The spring is configured to bias the septum activator toward the at rest position. 
         [0012]    In some such embodiments, the movable member can be integrally formed with the septum activator. In other embodiments, the movable member can be formed separately formed the septum activator. 
         [0013]    In some additional embodiments the spring can be arranged so that when the movable member is moved distally relative to the catheter adapter, the spring is compressed between the movable member and the stationary arm. In some such embodiments, the spring may not be directly attached to the stationary arm, and in further embodiments the spring can be directly attached to the movable member. 
         [0014]    In yet additional embodiments, the spring can be arranged so that when the movable member is moved distally relative to the catheter adapter, the spring is stretched between the movable member and the stationary arm. 
         [0015]    In some embodiments, the septum activator can be configured to be urged from the at rest position distally to the actuated position when a coupler extension applies a force to a proximal end of the septum activator. 
         [0016]    In accordance with still another embodiment, the present disclosure provides a catheter assembly comprising a catheter adapter defining an internal space, and a septum activator defining a septum activator lumen and having a proximal side opening formed through a side wall of the septum activator. A blood flashback chamber can be defined between the septum activator side wall and an inner surface of the catheter. A one-way valve is provided at the proximal side opening. The one-way valve enables a distally-directed fluid flow to flow therethrough from the septum activator lumen into a space between the septum activator and the inner surface of the catheter adapter so that the distally-directed fluid flow can flush blood in the flashback chamber in a distal direction and out of the catheter adapter. 
         [0017]    In some such embodiments, the one-way valve can comprise a hinged flap. 
         [0018]    In yet additional embodiments, the one-way valve can comprises a hydrophobic surface. 
         [0019]    In still further embodiments, a distal side wall can be formed through the side wall of the septum activator and spaced distally from the proximal side wall. 
         [0020]    In still additional embodiments, the septum activator can comprise an inner tubular body and an outer tubular body that are movable relative to one another between a blocked arrangement and an aligned arrangement. Proximal and distal side openings formed through side walls of each of the inner and outer tubular bodies being aligned when the bodies are in the aligned arrangement. In some such embodiments, the one-way valve can be placed over one or the other of the proximal side openings of the inner and outer tubular bodies. In further embodiments, the one-way valve can be limited to only the proximal side openings. 
         [0021]    Further additional embodiments can involve methods of using and/or making any of the embodiments described herein. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]      FIG. 1  shows a schematic view of a catheter assembly having features in accordance with the present disclosure; 
           [0023]      FIG. 2  is an exploded, cutaway view of the catheter assembly of  FIG. 1 ; 
           [0024]      FIG. 3  is a perspective view of a septum activator in accordance with one embodiment; 
           [0025]      FIG. 4  is a cutaway view showing a catheter adapter with an introducer needle extending therethrough; 
           [0026]      FIG. 5  is a perspective view of a septum for use in the catheter adapter of  FIG. 4 ; 
           [0027]      FIG. 6  shows the catheter adapter of  FIG. 1  with an external coupler about to be connected; 
           [0028]      FIG. 7  shows the arrangement of  FIG. 4  with a connector engaged; 
           [0029]      FIGS. 8A-8D  shows additional embodiments of a septum activator; 
           [0030]      FIG. 9  is a cutaway view showing another embodiment of a catheter adapter employing the septum activator of  FIG. 8A ; 
           [0031]      FIG. 10A  is a perspective view of another embodiment of a septum; 
           [0032]      FIG. 10B  is a cross-sectional view taken along line  10 B- 10 B of  FIG. 10A ; 
           [0033]      FIG. 11  is a cutaway view showing another embodiment of a catheter adapter employing the septum activator of  FIG. 8D ; 
           [0034]      FIG. 12  is a perspective view of yet another embodiment of a septum activator; 
           [0035]      FIG. 13  is a cutaway view showing another embodiment of a catheter adapter employing the septum activator of  FIG. 12 ; 
           [0036]      FIG. 14  shows the arrangement of  FIG. 13  with a connector engaged; 
           [0037]      FIG. 15  is a perspective view of a septum activator in accordance with still another embodiment, shown in a first arrangement; 
           [0038]      FIG. 16  shows the septum activator of  FIG. 15  in a second arrangement; 
           [0039]      FIG. 17A  is a cutaway view taken along line  17 - 17  of  FIG. 16 ; 
           [0040]      FIG. 17B  depicts another embodiment shown from the same view as in  FIG. 17A ; 
           [0041]      FIG. 17C  depicts yet another embodiment shown from the same view as in  FIG. 17A ; 
           [0042]      FIG. 18  is a cutaway view showing another embodiment of a catheter adapter employing a septum activator as in  FIGS. 15-16 ; and 
           [0043]      FIG. 19  shows the arrangement of  FIG. 18  with a coupler attached. 
       
    
    
     DESCRIPTION 
       [0044]    With initial reference to  FIG. 1 , an embodiment of a catheter assembly  18  is shown. The catheter assembly  18  includes a catheter adapter  20 , also sometimes referred to as a catheter hub, having a distal end  22  and a proximal end  24 . A catheter tube  30  extends from the distal end  22  of the adapter and terminates at a catheter distal end  32 . A flange  34 , which may comprise threads, at the proximal end  24  of the catheter adapter  20  is configured to releasably accommodate other components, such as a coupler for coupling IV fluid tubing in a luer fit or threaded arrangement. 
         [0045]    As shown, and with additional reference to  FIG. 2 , an introducer needle  40  has a hollow distal tip  42 . In the illustrated embodiment, an outlet aperture  44  in the form of (or as part of) a notch is formed through a side of the introducer needle  40  proximal the distal tip  42 . In the illustrated embodiment, the aperture  44  is elongated and has a distal end  43  and a proximal end  45 . The aperture  44  can be formed in various ways and by conventional means, including by crimping the needle and forming an aperture in part or all of the crimped portion. A needle hub  46  is engaged with the proximal end  24  of the catheter adapter  20 . The introducer needle  40  extends from the hub  46  through the catheter adapter  20  and the catheter tube  30  so that its distal tip  42  is disposed just distal of the distal end  32  of the catheter tube  30 . 
         [0046]    With reference next to  FIGS. 2-5 , the catheter adapter  20  defines an internal lumen  56  extending from the proximal end  24  to the distal end  22 . A septum seat  58  is formed in an inner wall  59  of the catheter adapter  20 . A valve, which can be in the form of an elastomeric septum  60 , preferably is configured to fit in the septum seat  58  so as to sealingly engage the inner wall  59  of the catheter lumen  56  at the septum seat  58 . The illustrated septum  60  has a distal face  62 , a proximal face  64 , and a circumferential surface  65 . At least one slit  66  is formed through the septum  60  so that the septum  60  can be selectively deformed in order to open the slit and break the seal. Also, preferably the introducer needle  40  can extend through the slit  66 , but edges of the slit  66  will engage the outer wall of the needle so as to maintain a full or partial sealing engagement with the needle  40 . 
         [0047]    As best shown in  FIG. 4 , a distal chamber  70  is defined within the catheter adapter lumen  56  distal of the septum  60 . A proximal chamber  72  is defined proximal of the septum  60 . 
         [0048]    With continued reference to  FIGS. 2-4 , a septum activator  74  has a distal end  76  at which a distal opening  78  is formed, and a proximal end  80  at which a proximal opening  82  is formed. The illustrated septum activator  74  has a transition section  84  disposed between the distal section  86  and a proximal section  88 . A diameter of the septum activator  74  increases moving proximally through the transition section  84  so that a proximal diameter  92  of the septum activator is greater than a distal diameter  90 . An activator lumen  94  is defined within the septum activator. 
         [0049]    As best shown in  FIG. 4 , when the catheter assembly is assembled, the septum activator  74  preferably is disposed within the proximal chamber  72  of the catheter adapter  20  so that the distal end  76  of the activator  74  is adjacent the proximal face  64  of the septum  60 , and the introducer needle  40  extends through the activator lumen  94 . Although not shown, the septum activator may include guides or fins along an exterior thereof for aligning to the catheter lumen to limit yawing and pitching. In the illustrated embodiment, an expansion groove  69  or cavity is formed in the proximal chamber  72  of the catheter adapter  20 , and the proximal section  88  of the activator  74  is adjacent the expansion groove  69 . The expansion groove  69  enlarges a nominal interior diameter of the catheter adapter to provide a space into which the septum activator  74  can expand. In some examples, the expansion groove is located distally of a luer inlet section of the catheter adapter and has an interior diameter larger than the luer inlet. 
         [0050]    With the catheter assembly  18  assembled as illustrated in  FIGS. 1 and 4 , the catheter assembly  18  is ready to be placed into a patient&#39;s blood vessel. In use, the clinician penetrates the patient&#39;s tissue using the distal tip  42  of the needle  40 . Once the distal tip  42  is in the blood vessel, blood will flow into the needle  40  at the tip  42  and out the aperture  44  into the catheter tube  30  and/or catheter adapter  20 . Blood can also flow into the interior cavity of the needle hub, which typically has a vent plug to prevent spilling out the needle hub. Blood flashback can be expected to at least partially fill the distal chamber  70  of the catheter adapter  20 . In some embodiments, air vents may be formed through or around the septum  60  so as to relieve positive air pressure that may tend to resist blood flashback. In additional embodiments, the needle may not have an aperture, and flashback blood will flow through the needle to the needle hub, which may include a viewing port so the clinician can see flashback blood so as to verify that the needle tip has entered the blood vessel. Further, in some embodiments, after the clinician sees blood in the needle hub viewing port, the clinician advances the catheter tube over the needle until blood flows through the catheter tube and into the distal chamber  70 , verifying that the distal end  32  of the catheter tube  30  has entered the blood vessel. 
         [0051]    Once the catheter tube  30  is verified to be properly positioned with its distal end  32  in the patient&#39;s blood vessel, the introducer needle  40  can be removed. With the needle  40  removed, the septum  60  slit  66  closes, and preferably fully seals. 
         [0052]    With reference next to  FIGS. 6 and 7 , in some embodiments, after the introducer needle  40  has been removed a conduit coupler, such as a luer connecter  100 , can be connected to catheter adapter  20 . The illustrated coupler  100  comprises a nut or threaded collar  102  that threadingly engages the flange  34 . An extension  104 , such a male luer tip, extends distally from the nut  102  into the proximal chamber  72  of the catheter adapter  20 , which can have a female luer. The illustrated coupler  100  communicates with a tube  106  or has a hub body that communicates with a tube. The tube  106 , in turn, may be, or may be connected to, a source of IV fluids, a blood sample collection apparatus such as a vacuum tube or syringe, or other medical treatment delivery or collection devices as desired. 
         [0053]    During coupling of the conduit coupler  100  with the flange  34 , the extension  104  enters the proximal chamber  72 , and may engage and apply a distally-directed force to the proximal end  80  of the septum activator  74 , thus pushing the septum activator  74  distally to deform the septum  60 . As such, the slit  66  opens to form one or more fluid pathways F through the septum  60 . If the tube  106  communicates with a medical delivery device, such as a source of IV fluids, such IV fluids can then be delivered along the flow path into the catheter adapter  20 , through the open septum  60  and into the catheter tube  30  for delivery to the patient&#39;s blood vessel. Such IV fluids may also flush blood out of the distal chamber  70 . If the tube  106  communicates with or comprises a medical collection device, such as a blood sample collection tube or syringe, blood from the patient&#39;s blood vessel can then be aspirated along the flow path from the distal chamber  70  through the open septum  60  and into the tube  106  for collection. Preferably, after aspiration of blood, a fluid delivery device is connected via a coupler  100  and fluid is delivered to flush residual blood from inside surfaces of the activator and catheter adapter. 
         [0054]    In  FIG. 7 , the proximal section  88  of the septum activator  74  comprises an elastically compressible portion, so that the distally-directed force applied by the coupler extension  104  compresses the proximal section  88 , which in the illustrated embodiment collapses or folds over itself. Various structural compositions may be employed to make the proximal section  88  elastically compressible. For example, the proximal section  88  may be constructed of a different material than the distal and transition sections  86 ,  84  of the activator  74 . For example, the distal and transition sections  86 ,  84  may be constructed of a medical-grade rigid or semi-rigid plastic, while the compressible portion of the proximal section  88  may have a reduced thickness, may be made of an elastomeric material, may be divided into different subsections alternating between elastomeric material and rigid or semi-rigid plastics, and/or may include other materials or hybrids of mixed materials. 
         [0055]    Preferably, the compressible portion of the proximal section  88  is configured so that sufficient force is still communicated through the septum activator  74  to the septum  60  so as to deform the septum  60  and open the fluid pathway. With continued reference to  FIG. 7 , the expansion groove  69  receives at least a portion of the compressed proximal section  88 . In the illustrated embodiment, at least a portion of the compressed proximal section  88  engages a distal end  71  of the expansion groove  69  and, preferably, a portion of the catheter adapter&#39;s inner wall  59  in the groove  69 . The elastically-compressed portion of the proximal section  88  applies a force against the inner wall  59 , including the distal end  71 , in opposition to the distally-directed force applied by the coupler extension  104 . 
         [0056]    When the coupler  100  is removed, the deformed elastomeric septum  60  will exert a proximally-directed force that tends to urge the septum activator  74  proximally. Also, the elastically-compressed portion of the proximal section  88  will decompress. Preferably, as the elastically compressible portion decompresses it generates some momentum so that when the proximal section  88  reaches its relaxed state the momentum is transferred to the septum activator  74 , providing an additional proximally-directed force to urge it out of engagement with the septum  60 . As such, the septum  60  may reseal, and the septum activator  74  is again positioned proximal to the septum  60 , ready to again engage and deform the septum  60  upon attachment of another coupler  100 . 
         [0057]    With reference next to  FIG. 8A , another embodiment of a septum activator  74   a  comprises three or more elongate legs  96  extending along a portion of the length of the septum activator. The illustrated legs are configured to function as a compressible portion, deflecting when the septum activator is engaged and forced distally by the coupler. Apertures  98  are formed between adjacent legs  96 . The apertures  98  provide another path for fluid flow within the catheter adapter  20  and externally of the septum activator  74   a.  When the coupler  100  is removed, the deflected legs  96  spring back into their at-rest position, thus further urging the septum activator  74   a  proximally and out of engagement with the septum  60 . 
         [0058]    With reference next to  FIG. 8B , another embodiment of a septum activator  74   b  also comprises at least three elongate legs  96 , but the legs  96  extend along the majority of the length of the septum activator  74   b  and through the transition section  84  between the proximal portion and the distal portion.  FIGS. 8C and 8D  depict embodiments of septum activators  74   c,    74   d  having only two elongate legs  96 , and apertures between adjacent legs  96 . Similar to the embodiment of  FIG. 8B , the septum activator  74   d  of  FIG. 8D  incorporates elongate legs  96  that extend through the transition section between the distal and proximal sections of the activator. Still further embodiments may include more elongate legs, and may include legs of various cross-sectional shapes, stiffness values, materials, etc. In yet other embodiments, weakened or kinked sections may be incorporated with the septum actuator to define preferential collapsible sections when the septum actuator compressed by a male Luer. 
         [0059]    Referring next to  FIG. 9 , an embodiment is shown in which the septum activator  74   a  of  FIG. 8A  is disposed within a catheter adapter  20 , to which a coupler  100  is attached. As in the embodiments discussed above, the extension  104  of the coupler  100  engages and applies a distally-directed force to the proximal end  80  of activator  74   a,  which in turn engages and deforms the septum  60  to establish a fluid flow path F. As shown, the legs  96  of the activator  74   a  are compressed by the distally-directed force. More specifically, the legs  96  are forced to bow outwardly, and preferably engage the inner wall  59  of the catheter adapter  20 . Preferably at least the legs  96  of the activator  74   a  are formed of a compressible material or spring. When the distally-directed force applied by the coupler  100  is removed, the bowed legs  96  will tend to return to their at-rest position, and in the process will tend to urge the septum activator  74   a  proximally and out of engagement with the septum  60 . 
         [0060]    In the embodiment illustrated in  FIG. 9 , the catheter adapter  20  does not include an expansion groove as did the embodiment illustrated in  FIG. 7 . However, it is anticipated that additional embodiments can employ such an expansion groove or similar structure to accommodate the legs  96  when bowed outwardly. 
         [0061]    With reference next to  FIGS. 10A and 10B , another embodiment of an elastomeric septum  110  is shown. The septum  110  includes a distal face  112 , a proximal end  114 , and a circumferential surface  115 , which may also be referred to as a skirt, between the distal face  112  and proximal end  114 . A central cavity  118  extends distally from the proximal end  114 , terminating in a proximal face  119  opposite the distal face  112 . At least one slit  116  extends through the septum  110  from the distal face  112  to the proximal face  119 . In the illustrated embodiment, the septum  110  is slightly tapered so as to expand in diameter from the distal face  112  to the proximal end  114 . Other embodiments may not employ such a taper. 
         [0062]    With reference next to  FIG. 11 , an embodiment is shown in which the septum activator  74   d  of  FIG. 8D  is disposed within a catheter adapter  20 , to which a coupler  100  is attached. As in the embodiments discussed above, the extension  104  of the coupler  100  engages and applies a distally-directed force to the proximal end  80  of activator  74   d,  which in turn engages and deforms the septum  110  to establish a fluid flow path F. As shown, the legs  96  of the activator  74   d  are compressed by the distally-directed force, bowing the legs  96  outwardly and into engagement with the inner wall  59  of the catheter adapter  20 . When the distally-directed force applied by the coupler  100  is removed, the bowed legs  96  will tend to return to their at-rest position, and in the process will tend to urge the septum activator  74   a  proximally and out of engagement with the septum  60 . 
         [0063]    In the illustrated embodiment, the inner wall  59  of the catheter adapter  20  is tapered and uninterrupted by any septum seat. It is to be understood, however, that additional embodiments may include a septum seat for receiving the septum  110  and/or an expansion groove for receiving at least a portion of the bowed-out legs  96 . 
         [0064]    It is also to be understood that embodiments as described herein may employ one or the other of the septums  60 ,  110  as described herein, or may employ septums having other specific structural configurations. Notably, the apertures  98  in the illustrated embodiment will enable flushing of blood that may have accumulated in both the distal and proximal chambers  70 ,  72  of the catheter adapter  20  when the coupler  100  attaches a source of flushing fluid such as an IV fluid. 
         [0065]    With reference next to  FIGS. 12-14 , another embodiment is presented in which a stationary arm  120  ( FIG. 13 ), such as an inward protruding rib, is connected to the inner surface  59  of the catheter adapter  20 . Preferably the stationary arm  120  is in the form of a circumferential or partially-circumferential, inwardly-directed ridge unitarily formed as part of the catheter adapter  20 . The illustrated septum activator  74   e  comprises an outwardly-directed proximal flange  95 , to which a proximal end of a spring  122  is connected or bears against. The spring  122  is a coil spring that encircles the septum activator  74   e,  preferably in at least the proximal section  88  of the activator. 
         [0066]    As shown in  FIG. 13 , in an at-rest position, the septum activator  74   e  fits within the catheter adapter  20  with the distal end  76  of the activator  74   e  proximal and adjacent the proximal face  119  of the septum  110  (which, in the illustrated embodiment, is sealingly retained in a seat  58  defined in the inner surface  59  of the adapter  20 ). A distal end of the spring  122  is proximal the stationary arm  120  and adjacent a contact surface  124  of the arm  120 . 
         [0067]    With reference next to  FIG. 14 , when a coupler  100  is attached, the coupler extension  104  engages the proximal end  80  of the activator  74   e,  urging the activator distally so as to force the septum  110  into an open configuration, establishing a fluid flow path F. The illustrated activator  74   e  is rigid or semi-rigid so as not to compress substantially when moved distally. 
         [0068]    As the coupler extension  104  urges the activator  74   e  distally, the spring  122  engages the contact surface  124  of the arm  120 , and is compressed between the contact surface  124  and the flange  95 . When the coupler extension  104  is removed, the compressed spring  122  tends to expand, and exerts a proximally-directed force so as to urge the activator  74   e  proximally, out of engagement with the septum  110  and to the at-rest position. As such, the septum  110  can again close to reseal, and the activator  74   e  is poised to repeat the process upon connection of another coupler  100 . 
         [0069]    It is to be understood that additional embodiments may employ somewhat different structure. For example, in another embodiment, a movable member may be arranged within the catheter adapter  20  and interposed between the coupler extension  104  and the proximal end  80  of the catheter adapter  74   e.  The spring may be interposed between the stationary arm  120  and the movable member. In still other embodiments, a proximal end of the spring may be attached to a portion of the catheter adapter, and a distal end of the spring may be attached to the activator, so that when the activator is forced distally by the coupler, the spring elongates and is placed in tension. When the coupler is removed, the spring thus pulls the activator proximally. 
         [0070]    The embodiment illustrated in  FIGS. 12-14  employs a coil spring. It is to be understood that other styles, sizes, etc. of springs can be used in other embodiments. For example, one or a plurality of cantilever-type springs, or a plurality of small coil springs can be employed. Also, some spring embodiments may comprise elastomeric materials such as one or a plurality of sponge-like members or synthetic rubber members. Any suitable spring structure, in which energy is stored in the spring as the activator is forced distally by the couple, which energy urges the activator proximally when the coupler is removed, can be employed. It is also to be understood that other configurations of the septum activator, such as configurations employing apertures, or multi-piece configurations, may be employed, and such configurations may enable flushing of both the distal and proximal chambers  70 ,  72  of the catheter adapter  20  when the coupler  100  attaches a source of flushing fluid such as an IV fluid. 
         [0071]    With reference next to  FIGS. 15 and 16 , in accordance with another embodiment, a multi-piece septum activator  130  comprises an inner tubular body  140  and an outer tubular body  150 . The inner tubular body  140  has a distal end  141  and a proximal end  142 . Distal openings  144  are formed through a wall of the inner tubular body  140  near the distal end  141 . Proximal openings  146  are formed through a wall of the inner tubular body  140  near its proximal end  142 . A proximal flange  148  is formed at the proximal end  142  of the inner tubular body  140 . The inner tubular body  140  defines an activator lumen  132 . 
         [0072]    The outer tubular body  150  also has a distal end  151  and a proximal end  152 . Distal openings  154  are formed through a wall of the outer tubular body  150  near the distal end  151 , and proximal openings  156  are formed through a wall of the outer tubular body  150  near its proximal end  152 . A circumferential seal  158  extends radially outwardly at the proximal end  152  of the outer tubular body  150 . 
         [0073]    With continued reference to  FIGS. 15 and 16 , the inner and outer tubular bodies  140 ,  150  are arranged coaxially and movable relative one another between a first or blocked arrangement as shown in  FIG. 15  and a second or aligned arrangement as shown in  FIG. 16 . In the aligned arrangement, the distal openings  144  of the inner tubular body  140  are aligned with the distal openings  154  of the outer tubular body  150  and the proximal openings  146  of the inner tubular body  140  are aligned with the proximal openings  156  of the outer tubular body  150 . However, in the blocked arrangement, the openings of the inner and outer tubular bodies are not aligned. As such, fluids can flow through the openings  146 ,  156 ,  144 ,  154 , when the activator  130  is in the aligned arrangement, but are blocked from flowing into or out of the activator lumen  132  when the activator  130  is in the blocked arrangement. 
         [0074]    In the illustrated embodiment, a plurality of elongated recesses or tracks  160  can be formed in the outer tubular body  150 , and complementary protuberances  162  can be formed on the inner tubular body  140 . The protuberances  162  fit within the tracks  160 , and maintain proper alignment when the tubular bodies  140 ,  150  move axially relative to one another. Preferably, the tracks  160  also define endpoints limiting relative movement of the tubular bodies between the blocked and aligned arrangements. It is to be understood, however, that in other embodiments the tubular bodies  140 ,  150  can be configured to move rotatably relative to one another between blocked and aligned arrangements. 
         [0075]    With continued reference to  FIGS. 15 and 16 , and additional reference to  FIG. 17A , a one-way valve  166  is arranged at each of the proximal openings  156  of the outer tubular body  150 . In the illustrated embodiment, each one-way valve  166  comprises a flap  170  that covers the associated proximal opening  156 . Preferably, a proximal end of each flap  170  is hingedly connected to the outer tubular body  150  by a hinge  172  at or adjacent the proximal end of each proximal opening  156 . The hinge  172  can comprise an elastomeric material or can, in additional embodiments, comprise any desired hinge structure. Similarly, each flap can comprise an elastomeric material, a rigid or semi-rigid material, or combinations thereof. Preferably, side and distal edges of each flap  170  are not attached to the outer tubular body  150 , but the flap  120  is biased to urge the side and distal edges into engagement with the body  150 . A flap receiver  174  can be configured to receive at least a distal edge of the flap  170 . Each flap  170  can hingedly open outwardly, but is prevented by the flap receiver  174  from hingedly opening in an inward direction. As such, each flap  170  forms a one-way valve, tending to open to allow fluids to flow out of the lumen  132  through the associated proximal opening  156  but tending to close to prevent fluids from flowing inwardly through the proximal opening  156 . 
         [0076]    With specific reference to  FIG. 17A , in one embodiment, the flap receiver  174  comprises a cutout portion of the outer tubular body  150 . In this embodiment, the outer surface of the flap is aligned with the outer surface of the tubular body  150 . It is to be understood that, in other embodiments, the flap can engage and form a seal with the associated tubular body using other structures. For example, the flap can rest atop the outer surface of the associated tubular body without any notch or other receiving structure being formed therein. In another embodiment represented in  FIG. 17B , a layer of a hydrophobic material  180  can be applied to the flap receiver  174 , providing additional resistance to fluid passing between the flap  170  and the receiver  174 . In yet additional embodiments, an inner surface of the flap, or portions of both and outer surface and inner surface of the flap can be coated with a layer of hydrophobic material in addition to or instead of the layer  180  applied to the flap receiver  174 . The hydrophobic layer  180  can be made from any of a number of suitable materials well known to those skilled in the art, such as super hydrophobic polyvinyldiflouride (PVDF). With specific reference next to  FIG. 17C , in yet another embodiment, the flap receiver  74  can comprise a seal seat  188  configured to receive and hold a seal such as an O-ring  190 . In such an embodiment, the flap  170  closes upon the O-ring  190  so as to effect a seal. 
         [0077]    With reference next to  FIG. 18 , the multi-piece activator  130  can be placed in the proximal chamber  72  of the catheter adapter  20 . Preferably, the multi-piece activator  130  is initially disposed in the blocked arrangement as shown. In some embodiments, one or more vents  195  can be formed around the septum  110 . As such, a portion of flashback blood B that enters the distal chamber  70  can flow through the vents  195  and into the proximal chamber  72 . In some embodiments, the proximal chamber  72  may operate as a viewing window through which a clinician can detect flashback blood B. Preferably, the seal  158  of the outer tubular body  150  engages the inner surface  59  of the catheter adapter  20  so as to prevent blood from flowing therethrough and, possibly, out of the catheter adapter  20 . Since the multi-piece activator  130  is in the blocked arrangement, blood B is blocked from flowing into the lumen  132 . 
         [0078]    With additional reference to  FIG. 19 , when a coupler  100  such as a luer coupler is connected to the proximal flange  34 , the extension  104  of the coupler will engage the proximal flange  148  and urge the inner tubular body  140  distally relative to the outer tubular body  150  until the tubular bodies are in the aligned arrangement. Once the tubular bodies are in the aligned arrangement, they will move distally together relative to the catheter adapter  20  so that their aligned distal ends  141 ,  151  engage and deform the septum  110 , breaking the seal and establishing a fluid flow path therethrough. 
         [0079]      FIG. 19  illustrates an embodiment in which the coupler  100  is connected to a source of medical fluids such as IV fluids F. As shown, IV fluids F are delivered distally through the activator lumen  132  and open septum  111  and into the catheter tube  30  for delivery to the patient. Also, the pressure of the fluids F being delivered to the activator  130  forces the flaps  170  to open so that fluids F flow out of the lumen  132  through the aligned proximal openings  146 ,  156 , into and through the proximal chamber  72 , and then back into the lumen  132  through the aligned distal openings  144 ,  154 . As such, flashback blood B within the proximal chamber  72  can be flushed out of the chamber  72  by the IV fluids F. 
         [0080]    In additional embodiments, a septum activator that does not have inner and outer tubular bodies employs a single tubular body with both proximal and distal openings and a one-way valve arranged at the proximal openings. 
         [0081]    Although inventive subject matter has been disclosed in the context of certain preferred or illustrated embodiments and examples, it will be understood by those skilled in the art that the inventive subject matter extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses the invention and obvious modifications and equivalents thereof. For example, a method of making a catheter assembly as described herein, as well as a method of using such an assembly, is contemplated. In addition, while a number of variations of the disclosed embodiments have been shown and described in detail, other modifications, which are within the scope of the inventive subject matter, will be readily apparent to those of skill in the art based upon this disclosure. It is also contemplated that various combinations or subcombinations of the specific features and aspects of the disclosed embodiments may be made and still fall within the scope of the inventive subject matter. Accordingly, it should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the disclosed inventive subject matter. Thus, it is intended that the scope of the inventive subject matter herein disclosed should not be limited by the particular disclosed embodiments described above, but should be determined only by a fair reading of the claims that follow.