Abstract:
A medical access device provides needleless access to patient fluid lines such as intravascular catheters. A preformed crimp ring is attached around a septum and the top end of the housing of the medical access device. The crimp ring is configured to hold the septum in place. The septum provides access for a tubular portion of a medical device such as a male luer taper of a syringe. The crimp ring is then attached by mechanical attachment and/or chemical adhesion to the housing to minimize axial and rotational movement between the septum and the housing.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates to a connector for accessing patient fluid lines. In particular, the present invention is an access connector that may be opened by a tubular portion of a medical device, such as a male luer taper of a syringe.  
         [0002]     In the course of treating patients, clinicians are continually transferring patient fluids between various containers and intravascular (IV) lines or through IV catheters. Transfer of these fluids is preferably through a closed system to prevent microbes from entering the system and causing infections in the patients.  
         [0003]     Many of these closed systems have relied on the use of a needle to penetrate a rubber or silicone septum to gain access to the fluid lines. The clinician may then inject fluid into or withdraw fluid from the patient via a needle and syringe. The septum then reseals after the needle is withdrawn, which prevents backflow of the fluids and closes the system once again.  
         [0004]     Because of the concern over accidental puncture with needles contaminated with a patient&#39;s blood or other fluids, needleless mechanisms have been developed to access patient fluid lines. One such mechanism utilizes a silicone septum that has a slit in it wide enough to allow a standard male luer taper to access the fluids. In this type of mechanism, the silicone septum is encompassed by a thermoplastic housing. With current connectors, the septum is bonded to the housing with adhesive.  
         [0005]     Bonding between the septum and housing prevents the septum from rotating within the housing while a male luer-lock taper is locked and unlocked from the connector. In addition, as a male luer taper is drawn out of the septum, the taper tends to stick to the septum and stretches the septum out of the housing. If the septum is not bonded to the housing, the septum will pull out, or, as the taper slips off the septum, the septum snaps back into the housing causing fluids to spatter.  
       BRIEF SUMMARY OF THE INVENTION  
       [0006]     The present invention is an access connector for accessing patient fluid lines. The access connector includes a housing, a crimp ring, and a septum. The crimp ring is formed prior to being mechanically attached around the septum, which has been inserted into a channel within the housing. The septum provides a tubular portion of a medical device resealable access to the fluid line. The present invention minimizes axial and rotational movement between the housing and the septum to allow optimum performance by the connector. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]      FIG. 1A  is a perspective view of a first representative embodiment of an access connector.  
         [0008]      FIG. 1B  is a cross-sectional view of the first access connector.  
         [0009]      FIG. 1C  is a cross-sectional view of the septum, crimp ring and housing of the first access connector.  
         [0010]      FIG. 2A  is a perspective view of a second representative embodiment of an access connector.  
         [0011]      FIG. 2B  is a cross-sectional view of the septum, crimp ring and housing of the second access connector.  
         [0012]      FIG. 3A  is a perspective view of a third representative embodiment of an access connector.  
         [0013]      FIG. 3B  is a cross-sectional view of the septum, crimp ring and housing of the third access connector.  
         [0014]      FIG. 4A  is a perspective view of a fourth representative embodiment of an access connector.  
         [0015]      FIG. 4B  is a perspective view of the crimp ring of the fourth access connector.  
         [0016]      FIG. 5  is a perspective view of a fifth representative embodiment of an access connector.  
         [0017]      FIGS. 6 and 7  are side views showing a method of deforming a crimp ring.  
         [0018]      FIG. 8  is a side view of a deformed crimp ring and septum. 
     
    
     DETAILED DESCRIPTION  
       [0019]      FIGS. 1A-1C  show components of a representative embodiment of access connector  10   a.    FIG. 1A  shows access connector  10   a  with housing  12 , crimp ring  14  and septum  16 . Housing  12  also includes body  18  and base  20  with fluid line port  20   a.    
         [0020]     Housing  12  is typically made of thermoplastic material such as polycarbonate, polyester and blends of the two. Crimp ring  14  may be fabricated from the same material or same class of materials. Alternatively, crimp ring  14  may be fabricated from metal such as stainless steel or aluminum. Septum  16  is typically made from silicone or polyisoprene. Housing  12 , crimp ring  14  and septum  16  may be fabricated from other materials as long as septum  16  is flexible, while housing  12  and crimp ring  14  are relatively rigid.  
         [0021]     Crimp ring  14  surrounds the top of septum  16  and is attached to the top end of body  18 . Base  20  is attached to the bottom end of body  18 , and port  20   a  extends from the bottom end of base  20 .  
         [0022]     In use, connector  10   a  is connected to a patient fluid line via port  20   a.  The patient fluid line may be any of a number of types such as IV lines, saline wells, arterial lines, hemodialysis lines, etc. When connected, the system remains closed to prevent entry of microbes that could cause infection and back flow of any fluids out of the system. The Q-Syte™ closed luer access device from Becton, Dickinson and Company is an example of a connector that may be assembled according to the present invention.  
         [0023]      FIG. 1B  shows connector  10   a  in more detail. In addition to the structures shown in  FIG. 1A ,  FIG. 1B  includes fluid channel  12   a  of housing  12 ; thread  22 , recess  24  and bottom edge  25  of body  18 ; lip  26  and barb  28  of crimp ring  14 ; slit  30 , top disk  32  with ridge  34 , column  36  and bottom disk  38  with annular groove  39  of septum  16  and rim  20   b,  channel  20   c,  sleeve  20   d  and thread  20   e  of base  20 .  
         [0024]     When assembled, bottom edge  25  of body  18  engages channel  20   b  of base  20  and these are bonded by ultrasonic welding, solvent bonding, adhesive bonding, etc. Rim  20   b  of base  20  mates with annular groove  39  of septum  16  to seal channel  12   a.    
         [0025]      FIG. 1C  shows the upper portion of connector  10   a  in more detail. Crimp ring  14 , body  18  and base  20  are formed separately, typically by injection molding unless crimp ring  14  is formed of metal. In the thermal injection molding process, the thermoplastic material used for crimp ring  14 , body  18  and base  20  is rigid at room temperature and melted just prior to injecting under pressure into crimp ring-shaped, body-shaped and base-shaped molds. The thermoplastic material cools and solidifies taking the shape of each mold cavity. Once cooled, crimp ring  14 , body  18  and base  20  are de-molded.  
         [0026]     Septum  16  is also typically formed by injection molding. Here, a two-component silicone is injected into a heated septum-shaped mold cavity under pressure. The two components, which are liquid at room temperature, contact the hot mold, and react and solidify taking the shape of the mold cavity. Septum  16  is de-molded while still hot and allowed to cool outside of the mold.  
         [0027]     To assemble connector  10   a,  bottom disk  38  of septum  16  is collapsed and inserted downward into body  18  until bottom disk  38  opens within body  18 , or top disk  32  may be collapsed and inserted upward into body  18  until top disk  32  opens over rim  25 . Base  20  is then positioned as described above and bonded by processes such as ultrasonic welding, solvent bonding, adhesive bonding, etc. to body  18 . These sections readily bond, because they are fabricated from the same material or same class of materials. However, base  20  may be attached at a later point in the manufacturing process.  
         [0028]     With the outer edges of top disk  32  positioned on the top end of body  18 , crimp ring  14  is placed over septum  16  such that lip  26  of crimp ring  14  engages ridge  34  of septum  16 . Alternatively, crimp ring  14  may be positioned over septum  16  prior to insertion of septum  16  into body  18 . Crimp ring  14  is sized so that a slight force must be exerted in order for barb  28  of crimp ring  14  to snap into recess  24  of body  18 . At this point, the components of connector  10   a  are secured by mechanical attachment for proper operation. When crimp ring  14  and body  18  are made of the same material or same class of material, these parts can additionally be chemically bonded by solvent bonding or adhesive bonding. It is important to note that any combination of attachment and bonding may be used.  
         [0029]     The components of housing  12  create channel  12   a  through connector  10   a.  Septum  16  acts as a resealable seal that allows fluid to pass through when septum  16  is opened by a tubular portion of a medical device. Once assembled, connector  10   a  is used to access a patient fluid line. A medical device having a tubular portion, such as a male luer taper of a syringe, is used to infuse or withdraw fluids from the patient fluid line via connector  10   a.  The male luer taper is inserted into slit  30  of septum  16  and, if the medical device has a luer lock, rotated to interlock the medical device with connector  10   a  via threads  22 . Medical devices that utilize a luer slip can also be used with connector  10   a  by simply sliding the male luer taper in place. Connector  10   a  may be fabricated without threads  22 , but then connector  10   a  could only be used in combination with a luer slip and not a luer lock.  
         [0030]     Once the male luer taper is in place, a clinician is then able to either infuse the patient fluid line or draw fluids from it. Medical devices having a luer lock are rotated in the opposite direction and pulled out for withdrawal from septum  16 , while medical devices having a luer slip are simply pulled out. Crimp ring  14  is typically shaped to compress septum  16  such that slit  30  is biased shut. (This is discussed below in more detail.) The system remains closed, and the risk of entry by microbes or leakage of contaminated fluids is minimized. In addition, there is no threat of accidental needle sticks.  
         [0031]     Attaching septum  16  by crimp ring  14  minimizes axial and rotational movement of septum  16  relative to housing  12 . For instance, maintaining the attachment between septum  16  and crimp ring  14  minimizes snapback, which was previously described.  
         [0032]     Crimp ring  14  is typically shaped such that it exerts a compressive force on septum  16  to bias slit  30  closed. In one embodiment, top disk  32  of septum  16  takes on an elliptical shape through the molding process. Slit  30  is positioned such that its longitudinal axis is perpendicular to the longitudinal axis of top disk  32 . Crimp ring  14  is molded such that it takes on a substantially circular shape. When crimp ring  14  is then attached around top disk  32 , it compresses top disk  32  along its longitudinal axis to bias slit  30  closed.  
         [0033]     In a second embodiment, crimp ring  14  is molded or deformed after being molded to take on an elliptical shape and positioned relative to slit  30  such that the longitudinal axis of slit  30  is aligned with the longitudinal, uncompressed axis of crimp ring  14 .  
         [0034]     Deforming crimp ring  14  is relatively easy, because its small size makes it quite malleable. A slight force applied on each side of crimp ring  14  is enough to deform it into the elliptical shape. Body  18 , which is much more rigid than crimp ring  14 , will maintain crimp ring  14  in the elliptical configuration. When formed of metal, crimp ring  14  readily holds the elliptical shape.  
         [0035]     The present invention improves the manufacture of connector  10   a  by eliminating the use of primer and adhesive to bond housing  12  and septum  26 , which is labor intensive and requires very tight process controls. Thus, restrictions on scaling up to high volume production are reduced. In addition, the attachments are stronger and more consistent than the adhesive bonds. Variations in the configuration of the top disk and crimp ring may provide additional advantages. Examples are described below.  
         [0036]      FIG. 2A  is a representative embodiment of connector  10   b.  Connector  10   b  includes housing  12 , crimp ring  40  and septum  16 . Housing  12  also includes body  42  and base  20  with patient fluid line port  20   a.    
         [0037]      FIG. 2B  shows the upper portion of connector  10   b  in more detail. In addition to the structures shown in  FIG. 2A ,  FIG. 2B  also shows slit  30  and top disk  32  with ridge  34  of septum  16 ; lugs  44 , lip  46  and sleeve  48  of crimp ring  40  and shoulder  50  of body  42 .  
         [0038]     Connector  10   b  is assembled as described for connector  10   a,  except that, unlike crimp ring  14 , crimp ring  40  has no means to mechanically attach to body  42 . In this embodiment, sleeve  48  is positioned on shoulder  50  of body  42 . Crimp ring  40  and body  42  are then bonded by ultrasonic welding, solvent bonding, adhesive bonding, etc.  
         [0039]     An additional difference between connectors  10   a  and  10   b  is that connector  10   b  uses lugs  44  instead of a thread. Lugs  44  are flange structures that are the means for interlocking with a luer lock. Lugs  44  are smaller and fabricated on crimp ring  40  instead of on body  42 .  
         [0040]      FIG. 3A  is a representative embodiment of connector  10   c.  Connector  10   c  includes housing  12 , crimp ring  52  and septum  16 . Housing  12  also includes body  54  and base  20  with patient fluid line port  20   a.    
         [0041]      FIG. 3B  shows the upper portion of connector  10   c  in more detail. In addition to the structures shown in  FIG. 3A ,  FIG. 3B  also shows slit  30  and top disk  32  with ridge  34  of septum  16 ; lip  56  and bottom edge  58  of crimp ring  52  and thread  60  and rim  62  of body  54 .  
         [0042]     Connector  10   c  is similar to connector  10   b  except that crimp ring  52  does not have a sleeve. Instead, bottom edge  58  of crimp ring  52  is seated on rim  62  of body  54 . Because there is no means for mechanical attachment, crimp ring  52  and body  54  are bonded by ultrasonic welding, solvent bonding, adhesive bonding, etc.  
         [0043]      FIG. 4A  is a representative embodiment of connector  10   d.  Connector  10   d  includes housing  12 , crimp ring  64  and septum  16 . Housing  12  also includes body  66  with lugs  68  and base  20  with port  20   a.    
         [0044]      FIG. 4B  shows crimp ring  64  in more detail. Crimp ring  64  includes lip  70 , barbs  72  and cut-outs  74 .  
         [0045]     In this embodiment, crimp ring  64  is fabricated from metal. Because metal is stronger, the thickness of the metal can be thinner than the thickness of the thermoplastic, and this allows for a larger septum and housing. However, in some cases, such as in imaging procedures, metal is not a desirable material in medical devices. It is also more difficult to form threads for luer locks using metal.  
         [0046]     To assemble connector  10   d,  septum  16 , body  66  and base  20  are assembled as described above. Crimp ring  64  is positioned over septum  16  such that lip  70  engages ridge  34  of septum  16  (See, for example,  FIG. 3B ), and lugs  68  are positioned within cut-outs  74 . The use of lugs  68  and cut-outs  74  overcome the difficulty associated with forming threads on crimp ring  64 . Crimp ring  64  is then attached to body  66  by pressing barbs  72  into body  66 . Crimp ring  64  cannot be removed once barbs  72  have penetrated the surface of body  66 . Alternatively, barbs  72  may engage recesses formed within body  66 . In other embodiments, an adhesive may be used in addition to or instead of barbs  72  for attaching crimp ring  64  to body  66 .  
         [0047]     Axial movement between septum  16  and crimp ring  64  is minimized as noted in previous examples. Barbs  72  and the combination of lugs  68  within cut-outs  74  also prevent rotational movement between the parts, so that connector  10   d  performs optimally.  
         [0048]     Crimp ring  64  may alternatively be molded thermoplastic. However, instead of barbs  72 , barbs that are similarly shaped to that shown in  FIG. 1B  would be required. In addition, body  66  would have recesses for engagement with the barbs, because thermoplastic barbs would not penetrate into body  66 , which is also fabricated from thermoplastic. Alternatively, as with other thermoplastic crimp rings, solvent bonding and ultrasonic welding as well as adhesive bonding could be used to attach crimp ring  64  and body  66 .  
         [0049]     The configurations of the crimp rings presented above are only examples. Other configurations may also be used that will impart the advantages of the invention.  
         [0050]     Another variation is shown in  FIG. 5 , which is a representative embodiment of connector  10   e.  Connector  10   e  includes housing  12 , crimp ring  82  and septum  84  with slit  86 . Here, crimp ring  82  and septum  84  are similar to crimp ring  52  and septum  16  of connector  10   c  ( FIGS. 3A-3B ) except that crimp ring  82  and septum  84  have a saddle configuration at the top of device  10   e.  The saddle provides additional bias to compress slit  86  and may be combined with any configuration of connector  10  to give the advantage of biasing slit  86  closed in order to maintain a closed system.  
         [0051]      FIG. 6  shows a method of forming the saddle shape of crimp ring  82  and septum  84  of connector  10   e  by deforming or shaping crimp ring  82 .  FIG. 6  shows crimp ring  82 , septum  84 , mandrel  88  with inner wall  88   a  and rim  90  and forming base  92  with inner wall  92   a  and rim  94 . Septum  84  includes top disk  84   a  and bottom disk  84   b.    
         [0052]     Mandrel  88  is saddle-shaped along rim  90 , heated and coated to have a non-stick surface. Forming base  92  is saddle-shaped along rim  94  in a mating fashion with rim  90  and may or may not be heated and/or coated. Both mandrel  88  and forming base  92  are cylindrical as indicated by inner walls  88   a  and  92   a,  respectively, and are sized such that rim  90  and rim  94  only contact crimp ring  82 .  
         [0053]     In operation, crimp ring  82  is placed over top disk  84   a  of septum  84  and inserted into forming base  80  such that top disk  84   a  is over rim  94  and bottom disk  84   b  is underneath forming base  92 . As shown in  FIG. 7 , when a force is applied to mandrel  88  as indicated by arrow  96 , rim  90  is pressed against crimp ring  82 , which is in turn pressed against rim  94  of forming base  92 . The heat and pressure causes the thermoplastic material of crimp ring  82  to form the saddle shape of mandrel  88  and forming base  92 .  
         [0054]     Depending on the type of thermoplastic material used to fabricate crimp ring  82 , crimp ring  82  and septum  84  may be retained between mandrel  88  and forming base  92  until the part cools in order to maintain the saddle shape. Septum  84  is fabricated from elastomeric silicone, which has a resilient quality, and therefore will have a tendency to return to its original shape. If crimp ring  82  is not stiff enough when hot to hold the saddle shape, then crimp ring  82  and septum  84  will need to remain between mandrel  88  and forming base  92  until cool. On the other hand, if crimp ring  82  is stiff enough when hot it can be removed and allowed to cool without the support of mandrel  88  and forming base  92 .  
         [0055]      FIG. 8  shows crimp ring  82  and septum  84  after deformation by the above process. The parts are subsequently inserted into and attached to housing  12  to form connector  10   e.    
         [0056]     Mechanically attaching a crimp ring around the septum of access connectors according to the present invention provides several advantages. The attachment between the parts is strong and consistent. In addition, the process is a method that can be scaled up for high volume production.  
         [0057]     Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.