Patent Publication Number: US-2019167966-A1

Title: Septum housing

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. patent application Ser. No. 15/286,278, filed Oct. 5, 2016, entitled SEPTUM HOUSING, which is incorporated herein in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     Generally, vascular access devices may be used for communicating fluid with a vascular system of a patient. For example, catheter assemblies may be used for infusing fluid, such as normal saline solution, various medicaments, and total parenteral nutrition, into a patient, withdrawing blood from a patient, or monitoring various parameters of the vascular system of the patient. 
     A common type of intravenous (IV) catheter is an over-the-needle peripheral IV catheter. As its name implies, an over-the-needle catheter may be mounted over an introducer needle having a sharp distal tip. At least the inner surface of the distal portion of the catheter tightly may engage the outer surface of the needle to prevent peelback of the catheter and thus facilitate insertion of the catheter into the blood vessel. The catheter and the introducer needle may be assembled so that the distal tip of the introducer needle extends beyond the distal tip of the catheter with the bevel of the needle facing up away from skin of the patient. The catheter and introducer needle are generally inserted at a shallow angle through the skin into a blood vessel. 
     In order to verify proper placement of the needle and/or catheter in the blood vessel, the clinician generally confirms that there is “flashback” of blood in a flashback chamber of the catheter assembly. Once placement of the needle has been confirmed, the clinician may temporarily occlude flow in the blood vessel at the catheter tip, remove the needle, leaving the catheter in place, and attach a device to the catheter assembly for fluid removal, input, or to seal the catheter assembly. This process has been somewhat difficult in practice since many placement sites simply do not allow easy occlusion of the target vessel. Additionally, even when such occlusion is achieved, it may be imperfect, thus resulting in blood leaking from the catheter assembly, endangering the medical personnel employing it. 
     Catheter and introducer needle assemblies have thus been provided in the art that provide a variety of seals or “septa” for preventing outflow of fluid during and following removal of the introducer needle. Septum dislodgement is often likely to result in fluid leakage. Septum dislodgement and fluid leakage from an IV catheter assembly may occur due to various circumstances. For example, fluid leakage may occur due to pressurization of the system, which may result from venous pressure, fluid injection under high or low pressure, flush of the system, blood collection, etc. 
     BRIEF SUMMARY OF THE INVENTION 
     The present application relates to generally to securement of a septum within a catheter assembly to prevent leakage of fluid from the catheter assembly, as well as related systems and methods. In some embodiments, the catheter assembly may include one or more of the following: a catheter, a catheter adapter, a septum housing, and a septum. In some embodiments, the septum may be at least partially disposed within the septum housing and configured to at least substantially seal a lumen of the catheter adapter. In some embodiments, the septum housing may prevent dislodgement or destabilization of the septum, thereby preventing leakage of fluid from the catheter adapter. 
     In some embodiments, the catheter assembly may be part of a closed IV catheter system, such as, for example, the BD NEXIVA™ Closed IV Catheter System or the BD NEXIVA™ DIFFUSICS™ Closed IV Catheter System. In the closed IV catheter system, an introducer needle may be withdrawn through the catheter adapter after insertion of the catheter into a blood vessel of a patient. When the introducer needle is withdrawn through the catheter adapter, a “needle channel” may be closed off from an external environment surrounding the catheter system. Further, a side port of the catheter adapter may be connectable to blood withdrawal or infusion means via an extension tube that may extend from the side port of the catheter adapter and may be in fluid communication with the lumen of the catheter adapter. In some embodiments, the septum and/or the septum housing may be disposed proximal to the side port of the catheter adapter. 
     In some embodiments, the catheter assembly may be part of another type of catheter system. In some embodiments, the catheter adapter may include a distal end, a proximal end, an inner wall extending between the distal end and the proximal end, and a lumen formed by the inner wall. In some embodiments, the septum housing may be disposed within the lumen of the catheter adapter. In some embodiments, the septum housing may include one or more protrusions. In some embodiments, the one or more protrusions may include a lip. In some embodiments, the septum housing may be secured to the inner wall of the catheter adapter by one or more of the following: an interference fit between the one or more protrusions and the inner wall, a snap fit between the one or more protrusions and the inner wall, bonding between the one or more protrusions and the inner wall, and threading securing the one or more protrusions to the inner wall. 
     In some embodiments, the inner wall may include a groove or opening. In some embodiments, the septum housing may be resilient, and in response to the one or more protrusions aligning with the groove or opening, the septum housing may resiliently move outward to retain the one or more protrusions within the groove or opening in the snap fit. In further detail, in some embodiments, in response to the septum housing being inserted into the distal end of the catheter adapter, the one or more protrusions may be biased inwardly and/or in response to the one or more protrusions being further inserted into the distal end and aligning with the groove or opening, the one or more protrusions move resiliently outward such that the one or more protrusions are retained in the groove or opening. 
     In some embodiments, the bonding between the one or more protrusions and the inner wall may include adhesive bonding. Additionally or alternatively, in some embodiments, the bonding between the one or more protrusions and the inner wall may include chemical bonding. Additionally or alternatively, in some embodiments, the bonding between the one or more protrusions and the inner wall may include ultrasonic welding. Additionally or alternatively, in some embodiments, the bonding between the one or more protrusions and the inner wall may include laser welding. Additionally or alternatively, the one or more protrusions may include one or more threads, which may be disposed on a distal end of the septum housing. In some embodiments, the inner wall of the catheter adapter may include corresponding threads to secure the septum housing to the inner wall. 
     In some embodiments, the lip may extend around all or a portion of a circumference of the septum housing. In some embodiments, the lip may be disposed at a distal end of the septum housing. In some embodiments, the adhesive bonding and/or the chemical bonding may extend along an exterior of the septum housing proximal to the lip. In some embodiments, the inner wall may include a ring that contacts the exterior of the septum housing proximal to the lip such that a cavity is formed between the ring and the lip. In some embodiments, the cavity may extend around an outer circumference of the septum housing and/or an inner circumference of the catheter adapter. In some embodiments, the cavity may secure the adhesive bonding and/or the chemical bonding. 
     In some embodiments, the catheter adapter may include a vent hole that provides a venting pathway between an exterior of the catheter assembly and the adhesive bonding and/or the chemical bonding. In some embodiments, the vent hole and the venting pathway may be used to access the catheter adapter to introduce the adhesive bonding and/or the chemical bonding into the catheter adapter. In some embodiments, the venting pathway may provide access and/or venting to the cavity. In some embodiments, the cavity may include an angled proximal surface, which may facilitate spreading of the adhesive bonding and/or the chemical bonding through the cavity and around the outer circumference of the septum housing. 
     In some embodiments, the bonding between the septum housing and the inner wall and/or between the septum and the inner wall may be disposed at various locations on the inner wall. In some embodiments, one or more of the following: adhesive bonding, chemical bonding, ultrasonic welding, and laser welding, may be disposed on all or some surfaces of the inner wall and/or the septum that are in contact. Additionally or alternatively, one or more of the following: adhesive bonding, chemical bonding, ultrasonic welding, and laser welding, may be disposed on all or some surfaces of the inner wall and/or the septum housing that are in contact. In some embodiments, the vent hole may be disposed at various locations within the catheter adapter to provide access to the catheter adapter and/or a venting pathway between the exterior of the catheter assembly and particular adhesive bonding and/or particular chemical bonding. In some embodiments, the vent hole may be disposed proximate to a proximal edge of the lip. In some embodiments, the catheter adapter may comprise a vent hole, and may further comprise port through which the adhesive or chemical bonding material is injected, wherein the vent hole prevents pressure buildup between the septum and/or the septum housing and the inner wall of the catheter adapter during the injection adhesive or chemical bonding material. 
     In some embodiments, the one or more protrusions of the septum housing may each include a resilient catch feature. In some embodiments, multiple catch features may be spaced apart about an outer circumference of the septum housing. In some embodiments, an exterior of the catheter adapter may include a safety mechanism engagement feature. In some embodiments, the safety mechanism engagement feature may be spaced apart from the opening in the inner wall. In some embodiments, the safety engagement feature may include a groove configured to selectively couple with a V-clip or similar clip. In some embodiments, the safety engagement feature may be spaced apart from the opening in the inner wall of the catheter adapter. 
     In some embodiments, the septum may be housed and retained within the catheter adapter without requiring a mechanical or interference interface with the septum housing. For example, the proximal end of the catheter adapter may abut and extend over a portion of a surface area of a proximal face of the septum, thereby retaining the septum within the catheter adapter. Thus, the catheter adapter may prevent the septum from moving proximally within the catheter adapter due to a wall at the proximal end of the catheter adapter that abuts and thereby partially blocks the proximal end of the catheter adapter. 
     In these and other embodiments, the catheter adapter may include at least two pieces. In some embodiments, the catheter adapter may include a proximal piece, a distal piece, and a lumen extending through the proximal piece and the distal piece. In some embodiments, the proximal piece and the distal piece may be selectively coupled together at a coupling. In some embodiments, the distal piece may include the side port. In some embodiments, the proximal piece may be disposed proximal to the side port. In some embodiments, the proximal and distal pieces may facilitate insertion of the septum into the catheter adapter given the proximal end of the catheter adapter may not include an opening large enough to fit the septum. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       In order that the manner in which the above-recited and other features and advantages of the invention are obtained will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof that are illustrated in the appended drawings. These drawings depict only typical embodiments of the invention and are not therefore to be considered to limit the scope of the invention. 
         FIG. 1A  is a cross-sectional top view of an example catheter assembly, according to some embodiments; 
         FIG. 1B  is an enlarged cross-sectional top view of a portion of the catheter assembly of  FIG. 1A , illustrating example ultrasonic welding, according to some embodiments; 
         FIG. 1C  is an enlarged cross-sectional top view of the portion of the catheter assembly of  FIG. 1B , illustrating example adhesive bonding, according to some embodiments; 
         FIG. 1D  is an enlarged cross-sectional top view of the portion of the catheter assembly of  FIG. 1B , illustrating example chemical bonding, according to some embodiments; 
         FIG. 1E  is a partial cutaway top view of an example threads of the catheter assembly of  FIG. 1A , according to some embodiments; 
         FIG. 1F  is a perspective view of the catheter assembly of  FIG. 1A , according to some embodiments; 
         FIG. 1G  is an exploded view of the catheter assembly of  FIG. 1A , according to some embodiments; 
         FIG. 2  is a cross-sectional view of an example septum and an example septum housing, according to some embodiments; 
         FIG. 3A  is a cross-sectional view of the portion of the catheter assembly of  FIG. 1B , according to some embodiments; 
         FIG. 3B  is a cross-sectional view of the portion of the catheter assembly of  FIG. 1B , illustrating example chemical bonding, according to some embodiments; 
         FIG. 4A  is a top view of another example catheter assembly, according to some embodiments; 
         FIG. 4B  is an upper perspective view of an example septum housing, according to some embodiments; 
         FIG. 4C  is a side view of a portion of the catheter assembly of  FIG. 4A , according to some embodiments; 
         FIG. 4D  is a cross-sectional view of the portion of the catheter assembly of  FIG. 4C , according to some embodiments; 
         FIG. 4E  is a proximal view of the catheter assembly of  FIG. 4A , according to some embodiments; and 
         FIG. 4F  is a lower perspective view of the catheter assembly of  FIG. 4A , illustrating an example safety mechanism securement feature and an example vent hole, according to some embodiments; 
         FIG. 5A  is an upper perspective view of another example septum housing and example septum, according to some embodiments; and 
         FIG. 5B  is a cross-sectional view of the septum housing and the septum of  FIG. 5A  disposed within an example catheter adapter. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The presently preferred embodiments of the present invention can be understood by reference to the drawings, wherein like reference numbers indicate identical or functionally similar elements. It will be readily understood that the components of the present invention, as generally described and illustrated in the figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description, as represented in the figures, is not intended to limit the scope of the invention as claimed, but is merely representative of presently preferred embodiments of the invention. 
     Moreover, the Figures may show simplified or partial views, and the dimensions of elements in the Figures may be exaggerated or otherwise not in proportion for clarity. In addition, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a terminal includes reference to one or more terminals. In addition, where reference is made to a list of elements (e.g., elements a, b, c), such reference is intended to include any one of the listed elements by itself, any combination of less than all of the listed elements, and/or a combination of all of the listed elements. 
     The term “substantially” means that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide. 
     As used herein, the term “proximal”, “top”, “up” or “upwardly” refers to a location on the device that is closest to the clinician using the device and farthest from the patient in connection with whom the device is used when the device is used in its normal operation. Conversely, the term “distal”, “bottom”, “down” or “downwardly” refers to a location on the device that is farthest from the clinician using the device and closest to the patient in connection with whom the device is used when the device is used in its normal operation. 
     As used herein, the term “in” or “inwardly” refers to a location with respect to the device that, during normal use, is toward the inside of the device. Conversely, as used herein, the term “out” or “outwardly” refers to a location with respect to the device that, during normal use, is toward the outside of the device. 
     Referring now to  FIG. 1A , in some embodiments, a catheter assembly  10  may include one or more of the following: a catheter  12 , a catheter adapter  14 , a septum housing  16 , and a septum  18 . In some embodiments, the catheter adapter  14  may include a distal end  20 , a proximal end  22 , an inner wall  24  extending between the distal end  20  and the proximal end  22 , and a lumen  26  formed by the inner wall  24 . In some embodiments, the septum housing  16  may be disposed within the lumen  26  of the catheter adapter  14 . 
     In some embodiments, the septum  18  may be at least partially disposed within the septum housing  16  and configured to at least substantially seal the proximal end  22  and/or a lumen of the catheter adapter  14 . In some embodiments, the septum housing  16  may prevent dislodgement or destabilization of the septum  18 , thereby preventing leakage of fluid from the catheter adapter. 
     In some embodiments, the catheter assembly  10  may be part of a closed IV catheter system, such as, for example, the BD NEXIVA™ Closed IV Catheter System, the BD NEXIVA™ DIFFUSICS™ Closed IV Catheter System, the BD Intima II™ Catheter, or similar catheter systems. In some embodiments, the catheter assembly may be part of another type of catheter system. In the closed IV catheter system, an introducer needle (not illustrated in  FIG. 1A ) may be withdrawn through the catheter adapter  14  after insertion of the catheter  12  into a blood vessel of a patient. When the introducer needle is withdrawn through the catheter adapter  14 , a “needle channel” may be closed off from an external environment surrounding the catheter assembly  10 . Further, a side port  28  of the catheter adapter  14  may be connectable to blood withdrawal or infusion means via an extension tube that may extend from the side port  28  of the catheter adapter and may be in fluid communication with the lumen  26  of the catheter adapter  10 . In some embodiments, the septum  18  and/or the septum housing  16  may be disposed proximal to the side port  28  of the catheter adapter  14 . 
     Referring now to  FIG. 1B , in some embodiments, the septum housing  16  may include one or more protrusions. In some embodiments, the septum housing may be secured to the inner wall  24  of the catheter adapter  14  by one or more of the following: an interference fit between the one or more protrusions and the inner wall  24 , a snap fit between the one or more protrusions and the inner wall  24 , and bonding between the one or more protrusions and the inner wall  24 . 
     In some embodiments, the inner wall  24  may include a groove  30  or opening (an example opening  70  is illustrated in  FIGS. 4A and 4C-4D ). It is understood that the inner wall  24  may include multiple grooves  30  and/or multiple openings and that each of the multiple grooves and/or the multiple openings may be configured to retain one or more of the protrusions. In some embodiments, the septum housing  16  may be resilient, and in response to the one or more protrusions aligning with the groove  30  or opening, the septum housing  16  may resiliently move outward to retain the one or more protrusions within the groove  30  or opening in the snap fit. In further detail, in some embodiments, in response to the septum housing  16  being inserted into the proximal end  22  of the catheter adapter  14 , the one or more protrusions may be biased inwardly and/or in response to the one or more protrusions being further inserted into the proximal end  22  and aligning with the groove  30  or opening, the one or more protrusions move resiliently outward such that the one or more protrusions are retained within the groove  30  or opening. 
     In some embodiments, when the one or more protrusions are aligned with the groove  30  in the snap fit, the one or more protrusions may be disposed in an interference fit with the groove  30 . As interference between the septum housing  16  and the catheter adapter  14  increases, there may be an increased probability and/or severity of deformation of the septum  18  and/or other components of the catheter assembly  10 . As interference between the septum housing  16  and the catheter adapter  14  increases, there may also be an increased likelihood of stress-induced crazing of the septum housing  18 , the catheter adapter  14  and/or other components of the catheter assembly  10 . In some embodiments, the interference fit between the one or more protrusions and the groove  30  may facilitate avoidance of the deformation and/or the stress-induced crazing while still providing support against dislodgement or destabilization of the septum  18 . In some embodiments, a lubricant, such as, for example, alcohol or silicone, may be used for uniform seating of the septum within the septum housing  16  and/or the catheter adapter  14 . The lubricant may also reduce stress-induced crazing. The lubricant may also increase a maximum pressure performance, which may include a maximum amount of pressure that can be applied to the septum  18  and/or the septum housing  16  without significant dislodgement of the septum  18  as the introducer needle is withdrawn. In some embodiments, an alcohol lubricant may increase the maximum pressure performance more than a silicone lubricant. 
     In some embodiments, the one or more protrusions of the septum housing may include a lip  34 . In some embodiments, the lip  34  may extend around all or a portion of a circumference of the septum housing  16 . In some embodiments, the lip  34  may be disposed at a distal end of the septum housing  16 . In some embodiments, the interference fit between the lip  34  and the groove  30  may be tighter due to the lip  34  being enlarged. An enlarged size of the lip  34  may increase the maximum pressure performance. In some embodiments, the lip  34  may provide better interference and greater maximum pressure performance than multiple protrusions, which may be spaced apart and not extend around an entire circumference of the septum housing  16 . 
     In some embodiments, the bonding between the one or more protrusions and the inner wall may include ultrasonic welding  32 . In some embodiments, the ultrasonic welding  32  may increase the maximum pressure performance. In some embodiments, laser welding may be used instead of or in addition to the ultrasonic welding  32 . In some embodiments, a premixed resin or colorant may be applied in a location of the laser welding and/or the ultrasonic welding  32 , which may create uniform transmissivity resulting in more consistent weld performance. 
     In some embodiments, the laser welding and/or the ultrasonic welding  32  may be configured not to fail a minimum threshold energy to facilitate adhesion or a maximum threshold energy to avoid damaging any components of the catheter assembly  10 , such as, for example, the septum  18 , the septum housing  16 , and the catheter adapter  14 . 
     In some embodiments, the bonding between the septum housing  16  and the inner wall  24  and/or between the septum  18  and the inner wall  24  may be disposed at various locations on the inner wall  24 . In some embodiments, the ultrasonic welding  32  may be disposed where the inner wall  24  contacts the septum  18  and/or the septum housing  16 . In some embodiments, the inner wall  24  may include one or more other protrusions or a ring  36 . In some embodiments, the one or more other protrusions or the ring  36  may form a proximal edge of the groove  30 . In some embodiments, the ultrasonic welding  32  may be disposed between the one or more other protrusions or the ring  36  and an external surface of the septum housing  16 , as illustrated in  FIG. 1B . 
     Referring now to  FIG. 1C , in some embodiments, the bonding between the one or more protrusions and the inner wall  24  may include adhesive bonding  38 . In some embodiments, the adhesive bonding  38  may include glue or another adhesive. In some embodiments, the adhesive bonding  38  may extend along an exterior of the septum housing  16  proximal to the lip  34 . In some embodiments, the ring  36  may contact the exterior of the septum housing  16  proximal to the lip  34  such that a cavity is formed between the ring  36  and the lip  34 . In some embodiments, the cavity may extend around an outer circumference of the septum housing  16  and/or an inner circumference of the catheter adapter  14 . In some embodiments, the multiple cavities may be formed between the one or more protrusions of the septum housing  16  and the one or more other protrusions of the catheter adapter  14 . 
     In some embodiments, the catheter adapter  14  may include one or more vent holes  40  that provide venting pathways between an exterior environment of the catheter assembly  14  and the adhesive bonding  38  and/or the chemical bonding (illustrated in  FIG. 1D ). In some embodiments, the vent holes  40  and their corresponding venting pathways may be used to access the catheter adapter  14  to introduce the adhesive bonding  38  and/or the chemical bonding into the catheter adapter  14 , such as, for example, into the cavity of the catheter adapter  14 . In some embodiments, the venting pathways may each provide access and/or venting to the cavity. In some embodiments, the cavity may include an angled proximal surface  42 , which may facilitate spreading of the adhesive bonding  38  and/or the chemical bonding through the cavity and around the outer circumference of the septum housing  16 . 
     In some embodiments, the vent holes  40  may be disposed as various locations within the inner wall  24  of the catheter adapter  14  to provide access to the catheter adapter  14  and/or a venting pathway between the exterior of the catheter assembly  10  and particular adhesive bonding  38  and/or particular chemical bonding. In some embodiments, a particular vent hole  40  may be disposed proximate to a proximal edge of the lip  34 . 
     In some embodiments, the ring  36  may include a retention ring or washer that may be placed around the lip  34  or another portion of the septum housing  16 . In some embodiments, the adhesive bonding  38  may be disposed between the retention ring and the inner wall  24 . 
     Referring now to  FIG. 1D , in some embodiments, the bonding between the one or more protrusions and the inner wall  34  may include solvent or chemical bonding  44 . In some embodiments, the chemical bonding  44  may be disposed where the inner wall  24  contacts the septum  18  and/or the septum housing  16 . 
     Referring now to  FIG. 1E , in some embodiments, the one or more protrusions may include one or more threads  46 , which may be disposed on a distal end of the septum housing  16 . In some embodiments, the inner wall  24  of the catheter adapter  14  may include corresponding threads  48  to secure the septum housing  16  to the inner wall  24 . 
     Referring now to  FIG. 1F , in some embodiments, an extension tube  50  is connected to the side port  28 . In some embodiments, the catheter assembly  10  may include a needle hub  52 . In some embodiments, a proximal end of the introducer needle  54  may be connected to the needle hub  52 . In some embodiments, the needle hub  52  may include a needle shielding mechanism. 
     Referring now to  FIG. 1G , in some embodiments, the septum  18  may be formed from two portions, a proximal portion  18   a  and a distal portion  18   b.  In some embodiments, each of the portions  18   a,    18   b  may be pre-slit to facilitate locating the introducer needle  54  therethrough. Suitable materials for the septum  18  may include a peroxide cured elastomer such as polyisoprene, silicone, and the like where the materials have a durometer in the range of 35-45 Shore A. 
     In some embodiments, the septum housing  16  may be constructed of a resilient material. Non-limiting examples of resilient material include stainless steel, polyethylene, polypropylene, polycarbonate, polyethylene terephthalate (PET), polyethylene terephthalate glycol-modified (PETG), and polyester. In some embodiments, the catheter adapter  14  may be constructed of a same or similar material as the septum housing  16  to facilitate strength of the bonding between the catheter adapter  14  and the septum housing  16 . 
     In some embodiments, the septum housing  16  may have an open proximal end and an open distal end. In some embodiments, the septum housing  16  may surround at least a portion of the proximal portion  18   a  and the distal portion  18   b  in an interference fit to hold the septum  18  in place in position in the catheter adapter  14 . In some embodiments, the septum housing  16  may extend along only a portion of the distal portion  18   b.  However, in some embodiments, the septum housing  16  may extend along an entire length of the septum  18  or just along the proximal portion  18   a.  In some embodiments, at least a portion of the septum  18  may engage the inner wall  24 . 
     In some embodiments, the septum housing  16  may be configured to apply a compressive force to the septum  18 . In some embodiments, the open proximal and distal ends of the septum housing  16  may allow the introducer needle  54  to extend through the septum  18  past the septum housing  16 . In some embodiments, the proximal end of the septum housing  16  may abut and extend over a portion of a surface area of a proximal face of the septum  18 . 
     In some embodiments, the septum  18  may be a low-drag septum, which may facilitate stability and uniformity of the septum  18  during insertion of the catheter assembly  10  into the blood vessel of the patient. Referring back to  FIG. 1B , in some embodiments, the septum  18  may include a hollow interior portion  56  formed between the proximal portion  18   a  and the distal portion  18   b.  The hollow interior portion  56  may minimize drag on introducer needle  54  as it is being withdrawn from catheter assembly  10 . 
     In some embodiments, an external diameter of at least a portion of the distal portion  18   b  may be greater than an internal diameter of catheter adapter  14 . In some embodiments, the external diameter of the distal portion  18   b  may be at least 5% larger than the internal diameter of the relevant portion of catheter adapter  14 . With this configuration, the catheter adapter  14  may exert a radial compressive force against the distal portion  18   b.  This compressive force may help to hold the septum housing  16  in place. 
     Although illustrated in  FIG. 1G  as a low-drag, two-piece septum  18 , the septum  18  may include various types of septa. For example, referring now to  FIG. 2 , in some embodiments, the septum  18  may be formed from one piece. In some embodiments, the one piece septum may be low-drag. In some embodiments, the septum  18  may be self-retaining, for example, the septum  18  may be at least partially retained within the septum housing  16  and/or the catheter adapter  14  by means of an interference or friction fit between the septum  18  and the inner wall  24 , a mass of the septum  18 , etc. 
     In some embodiments, the septum housing  58  may include or correspond to the septum housing  16 . In some embodiments, a length of the septum housing  58  may be less than a length of the septum housing  16 . The septum housing  58  may be secured to the inner wall  24  of the catheter adapter  14  similar to the septum housing  16 . For example, the septum housing  58  may be secured to the inner wall  24  by one or more of the following: an interference fit between the one or more protrusions and the inner wall  24 , a snap fit between the one or more protrusions and the inner wall  24 , and bonding between the one or more protrusions and the inner wall  24 . 
     Referring now to  FIG. 3A , in some embodiments, the septum  18  may be housed by the catheter adapter  14  without use of a particular septum housing, such as, for example, the septum housing  16  of  FIG. 1  or the septum housing  58  of  FIG. 2 . For example, the proximal end of the catheter adapter  14  may abut and extend over a portion of a surface area of a proximal face of the septum  18 . Thus, the catheter adapter  14  may prevent the septum  18  from moving proximally within the catheter adapter  14  due to a wall at the proximal end of the catheter adapter  14  that abuts the proximal end of the catheter adapter  14 . 
     In some embodiments, the catheter adapter  14  may include at least two pieces. In some embodiments, the catheter adapter  14  may include a proximal piece  60 , a distal piece  62 , and the lumen  26  extending through the proximal piece  60  and the distal piece  62 . In some embodiments, the proximal piece  60  and the distal piece  62  may be selectively coupled together at a coupling  63 . In some embodiments, the distal piece  62  may include the side port  28 . In some embodiments, the proximal piece  60  may be disposed proximal to the side port  28 . In some embodiments, the proximal and distal pieces  60 ,  62  may facilitate insertion of the septum  18  into the catheter adapter  14  during assembly of the catheter assembly  10  given that the proximal end of the catheter adapter  14  may not include an opening large enough to fit the septum  18 . 
     Referring now to  FIG. 3B , in some embodiments, the septum  18  may be secured to the inner wall of the catheter adapter  14  by bonding  65  between the septum  18  and the inner wall. The bonding may include one or more of the following: the adhesive bonding  38  described in the present disclosure, the chemical bonding  44  described in the present disclosure, or another suitable type of bonding. In some embodiments, the bonding may be disposed along at least a portion of a length of the septum  18 . 
     Referring now to  FIGS. 4A-4F , in some embodiments, a catheter assembly  64  may include or correspond to the catheter assembly  10 . In some embodiments, the one or more protrusions of the septum housing  16  may each include a resilient catch feature  66 . In some embodiments, multiple catch features  66  may be spaced apart about an outer circumference of the septum housing  16 . In some embodiments, the spacing of the catch features  66  may allow the septum housing  16  to be inserted through a proximal opening in the proximal end  22  without regard to orientation. 
     In some embodiments, an exterior of the catheter adapter  14  may include a safety mechanism engagement feature  68 . In some embodiments, the safety mechanism engagement feature  68  may be spaced apart from the opening  70  in the inner wall  24 . In some embodiments, the safety engagement feature  68  may include a groove configured to selectively couple with a V-clip or similar clip (not illustrated in  FIGS. 4A-4F ). In some embodiments, the safety engagement feature  68  may be spaced apart from the opening  70  in the inner wall of the catheter adapter  14 . In some embodiments, the safety engagement feature  68  may be disposed on an opposite side of the catheter adapter  14  as the opening  70 . In some embodiments, a particular vent hole  40  may be aligned with and/or disposed within the safety engagement feature  68 , as illustrated in  FIG. 4F . Although the septum illustrated in  FIGS. 4A-4F  is a two-piece septum  18 , in some embodiments, a one-piece septum  18  may be used. 
     Referring now to  FIGS. 5A-5B , in some embodiments, a catheter assembly  71  may include or correspond to the catheter assembly  10  or the catheter assembly  64 . As illustrated in  FIG. 5A , in some embodiments, the one or more protrusions of the septum housing  16  may include one or more catch features  72  disposed on one or more arms of the septum housing  16 , which may be constructed of a resilient material. In some embodiments, the septum housing  16  may include two of the catch features  72 , which may be disposed on opposite sides of the septum housing  16 . In some embodiments, each of the arms may be connected to a body of the septum housing  16  at a base on the corresponding arm opposite the catch feature  72 . In some embodiments, each of the arms may be spaced apart and/or separated from the body of the septum housing  16  along one or both sides of the arm and/or at an end of the arm opposite the base. 
     In some embodiments, in response to the septum housing  16  being inserted into the distal end of the catheter adapter  14 , the catch features  72  and the arms may be biased inwardly. In some embodiments, in response to catch features  72  being further inserted into the distal end and aligning with one or more grooves and/or openings  70 , the catch features  72  and arms may move resiliently outward such that the catch features  72  are retained in the grooves and/or the openings  70  in a snap fit. 
     In some embodiments, the catheter adapter  14  may include any suitable number of grooves or openings  70 , which may each be configured to retain one or more of the retention features  72 . As illustrated in  FIG. 1B , in some embodiments, the catheter adapter  14  may include two openings  70  which may be disposed on opposite sides of the catheter adapter  14 . In some embodiments, each of the openings  70  may be configured to retain at least one of the catch features  72 . 
     The present invention may be embodied in other specific forms without departing from its structures, methods, or other essential characteristics as broadly described herein and claimed hereinafter. The described embodiments are to be considered in all respects only as illustrative, and not restrictive. The scope of the invention is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.