Patent Publication Number: US-11638806-B2

Title: Blood collection devices, systems, and methods

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 17/676,964, filed Feb. 22, 2022, titled BLOOD COLLECTION DEVICES, SYSTEMS, AND METHODS, which is a continuation of U.S. patent application Ser. No. 17/535,821, filed Nov. 26, 2021, titled BLOOD COLLECTION DEVICES, SYSTEMS, AND METHODS, which claims priority to each of U.S. Provisional Patent Application No. 63/118,679, filed Nov. 26, 2020, titled BLOOD COLLECTION DEVICES, SYSTEMS, AND METHODS, U.S. Provisional Patent Application No. 63/225,992, filed Jul. 27, 2021, titled BLOOD COLLECTION DEVICES, SYSTEMS, AND METHODS, and U.S. Provisional Patent Application No. 63/256,625, filed Oct. 17, 2021, titled BLOOD COLLECTION DEVICES, SYSTEMS, AND METHODS; the entire contents of each of the foregoing applications are hereby incorporated by reference herein. 
    
    
     TECHNICAL FIELD 
     Certain embodiments described herein relate generally to devices, systems, and methods for blood collection and further embodiments relate more particularly to devices, systems, and methods for facilitating blood collection via a previously placed catheter, such as, for example, a peripheral intravenous catheter. 
     BACKGROUND 
     Known devices, systems, and methods for drawing blood, including drawing blood using a previously placed catheter, suffer from a variety of drawbacks. Embodiments disclosed herein remedy, ameliorate, or avoid one or more of such drawbacks. Other or further uses and methods are also disclosed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The written disclosure herein describes illustrative embodiments that are non-limiting and non-exhaustive. Reference is made to certain of such illustrative embodiments that are depicted in the figures, in which: 
         FIG.  1 A  is a schematic cross-sectional view of a proximal portion of an embodiment of a base catheter system placed within a patient; 
         FIG.  1 B  is a schematic cross-sectional view of a distal end of the base catheter system of  FIG.  1 A  within a blood vessel of a patient; 
         FIG.  2    is a perspective view of an embodiment of an access system configured to be coupled with an embodiment of a base catheter system, the access system being shown in an undeployed or retracted state; 
         FIG.  3    is a side elevation view of the access system of  FIG.  2    in the undeployed or retracted state; 
         FIG.  4    is another side elevation view of the access system of  FIG.  2    in a fully deployed or advanced state; 
         FIG.  5    is a cross-sectional view through a longitudinal axis of the access system of  FIG.  2   , with the access system in the fully deployed or advanced state; 
         FIG.  6    is a side elevation view of an embodiment of a cannula compatible with the access system of  FIG.  2   ; 
         FIG.  7    is a side elevation view of a distal portion of the access system of  FIG.  2    in the undeployed or retracted state; 
         FIG.  8    is a cross-sectional view of a distal portion of another embodiment of an access system shown in an undeployed or retracted state; 
         FIG.  9    is a cross-sectional view of a distal portion of another embodiment of an access system shown in an undeployed or retracted state; 
         FIG.  10    a cross-sectional view of a distal portion of another embodiment of an access system shown in an undeployed or retracted state; 
         FIG.  11    a cross-sectional view of a distal portion of another embodiment of an access system shown in an undeployed or retracted state; 
         FIG.  12    is a perspective view of an embodiment of a closed intravenous catheter system in a fully assembled state that may be referred to as an insertion configuration; 
         FIG.  13    is a perspective view of the closed intravenous catheter system of  FIG.  12    in a state in which a piercing implement has been removed from a hub and catheter tube, which state may be referred to as an access configuration; 
         FIG.  14    is a cross-sectional view of a portion of the closed catheter system of  FIG.  12    in the access configuration; 
         FIG.  15    is a perspective view of another embodiment of an access system configured to be coupled with embodiments of a base catheter system, the access system being shown in an undeployed or retracted state; 
         FIG.  16    is a cross-sectional view of the access system of  FIG.  15    in the undeployed or retracted state; 
         FIG.  17 A  is a perspective view of an embodiment of a housing that is compatible with the access system of  FIG.  15   ; 
         FIG.  17 B  is a cross-sectional view of the housing of  FIG.  17 A ; 
         FIG.  17 C  is another cross-sectional view of the housing of  FIG.  17 A ; 
         FIG.  18 A  is a perspective view of an embodiment of a coupling member that is compatible with the access system of  FIG.  15   ; 
         FIG.  18 B  is a cross-sectional view of the coupling member of  FIG.  18 A ; 
         FIG.  19 A  is a perspective view of an embodiment of a follower that is compatible with the access system of  FIG.  15   ; 
         FIG.  19 B  is another perspective view of the follower of  FIG.  19 A ; 
         FIG.  19 C  is a cross-sectional view of the follower of  FIG.  19 A ; 
         FIG.  20    is a cross-sectional view of an embodiment of a connector that is compatible with the access system of  FIG.  15   ; 
         FIG.  21    is a partially exploded elevation view of an embodiment of a cannula showing a tie layer separated from a two-component portion of the cannula that the tie layer is used to connect together; 
         FIG.  22    is an enlarged cross-sectional view of the cannula with the tie layer in place over the two-component portion of the cannula; 
         FIG.  23 A  is a cross-sectional view of a generally proximal portion of the access system of  FIG.  15    in a retracted state; 
         FIG.  23 B  is a cross-sectional view of a distal portion of the access system of  FIG.  15    in the retracted state; 
         FIG.  24    is an exploded perspective view of an embodiment of a base catheter assembly that includes an embodiment of an open intravenous catheter assembly and an embodiment of an extension set that is couplable to the open intravenous catheter assembly; 
         FIG.  25    is a cross-sectional view of the base catheter assembly of  FIG.  24    in an assembled state; 
         FIG.  26    is a side elevation view of the access system of  FIG.  15    in the retracted state coupled with the assembled base catheter assembly of  FIG.  25   ; 
         FIG.  27    is a cross-sectional view of a distal portion of the access system of  FIG.  15    in the retracted state coupled with the assembled base catheter assembly of  FIG.  25   ; 
         FIG.  28    is a cross-sectional view of the access system of  FIG.  15    in a fully deployed state while coupled with the assembled base catheter assembly of  FIG.  25   ; 
         FIG.  29 A  is a cross-sectional view of a generally intermediate portion of the access system while in the configuration depicted in  FIG.  28   ; 
         FIG.  29 B  is a cross-sectional view of a generally distal portion of the access system of  FIG.  15    and a proximal portion of the assembled base catheter assembly of  FIG.  25    while in the configuration depicted in  FIG.  28   ; 
         FIG.  29 C  is a cross-sectional view of distal ends of the access system of  FIG.  15    and the assembled base catheter assembly of  FIG.  25    while in the configuration depicted in  FIG.  28   ; 
         FIG.  30    is a perspective view of another embodiment of an access system configured to be coupled with embodiments of a base catheter system, with the access system being shown in a retracted or undeployed state; 
         FIG.  31    is a cross-sectional view of the access system of  FIG.  30   ; 
         FIG.  32 A  is a perspective view of an embodiment of a coupling member that is compatible with the access system of  FIG.  30   ; 
         FIG.  32 B  is a cross-sectional view of the coupling member of  FIG.  32 A ; 
         FIG.  33    is a cross-sectional view of a distal end of the access system of  FIG.  30   , while in the retracted or undeployed state, being advanced toward an embodiment of a closed intravenous catheter system, such as the closed intravenous catheter system of  FIG.  12   , for coupling therewith; 
         FIG.  34    is a cross-sectional view of the distal end of the access system of  FIG.  30   , while in the retracted or undeployed state, coupled with the closed intravenous catheter system; 
         FIG.  35    is a perspective view of another embodiment of an access system configured to be coupled with embodiments of a base catheter system, with the access system being shown in a retracted or undeployed state; 
         FIG.  36    is a cross-sectional view of the access system of  FIG.  35    in the retracted state; 
         FIG.  37 A  is a perspective view of an embodiment of a housing that is compatible with the access system of  FIG.  35   ; 
         FIG.  37 B  is a perspective cross-sectional view of the housing of  FIG.  37 A ; 
         FIG.  38 A  is a perspective view of an embodiment of a follower that is compatible with the access system of  FIG.  35   , the follower including a selective engagement feature; 
         FIG.  38 B  is a cross-sectional view of the follower of  FIG.  38 A ; 
         FIG.  39 A  is a perspective view of an embodiment of a reinforcing tube assembly that includes a reinforcing tube and a catch; 
         FIG.  39 B  is a cross-sectional view of the reinforcing tube assembly of  FIG.  39 A ; 
         FIG.  40    is a cross-sectional view of a distal end of the access system of  FIG.  35    when in the retracted state of  FIGS.  35  and  36   ; 
         FIG.  41    is a cross-sectional view of a distal region of the access system of  FIG.  35    when in the retracted state; 
         FIG.  42    is a cross-sectional view of an intermediate region of the access system of  FIG.  35    when in the retracted state; 
         FIG.  43    is a cross-sectional view of a generally proximal portion of the access system of  FIG.  35    when in the retracted state; 
         FIG.  44    is a cross-sectional view of the access system of  FIG.  35    coupled with an embodiment of a base catheter assembly, such as the base catheter assembly of  FIG.  24   , while the access system of  FIG.  35    is in the retracted state; 
         FIG.  45    is a cross-sectional view of a generally intermediate region of the access system of  FIG.  35    while in the retracted configuration depicted in  FIG.  44   ; 
         FIG.  46    is a cross-sectional view of a distal portion of the access system of  FIG.  35    and a proximal portion of the catheter assembly while the access system is in the retracted configuration depicted in  FIG.  44   ; 
         FIG.  47    is a cross-sectional view of the access system of  FIG.  35    coupled with the base catheter assembly while in a partially deployed state, or stated otherwise, while in an intermediate stage of deployment; 
         FIG.  48    is a cross-sectional view of an intermediate region of the access system of  FIG.  35    while in the intermediate deployment configuration depicted in  FIG.  47   ; 
         FIG.  49    is a cross-sectional view of a distal end of the access system of  FIG.  35    and a proximal portion of the base catheter assembly while the access system is in the intermediate deployment configuration depicted in  FIG.  47   ; 
         FIG.  50    is a cross-sectional view of the access system of  FIG.  35    coupled with the base catheter assembly while in a fully deployed state; 
         FIG.  51    is a cross-sectional view of an intermediate region of the access system of  FIG.  35    while in the fully deployed state depicted in  FIG.  50   ; 
         FIG.  52    is a cross-sectional view of a generally distal portion of the access system of  FIG.  35    and a proximal portion of the base catheter assembly while the access system is in the fully deployed state depicted in  FIG.  50   ; 
         FIG.  53    is a cross-sectional view of distal ends of the access system of  FIG.  35    and of the base catheter assembly while the access system is in the fully deployed state depicted in  FIG.  50   ; 
         FIG.  54    is a perspective view of another embodiment of an access system in a retracted state; 
         FIG.  55    is a cross-sectional view of the access system of  FIG.  54    in the retracted state; 
         FIG.  56 A  is an enlarged cross-sectional view of a distal region of the access system of  FIG.  54    in the retracted state; 
         FIG.  56 B  is an enlarged cross-sectional view of a proximal region of the access system of  FIG.  54    in the retracted state; 
         FIG.  57    is a perspective view of another embodiment of an access system in a retracted state; 
         FIG.  58    is a cross-sectional view of the access system of  FIG.  57   ; 
         FIG.  59    is an enlarged cross-sectional view of the access system of  FIG.  57    taken along the view line  59  in  FIG.  58    in which an embodiment of a sealing member positioned at a proximal end of a reinforcement tube is shown; 
         FIG.  60    is a cross-sectional view of another embodiment of a sealing member compatible with the access system of  FIG.  57   ; 
         FIG.  61    is a perspective view of another embodiment of an access system in a retracted state; 
         FIG.  62    is a cross-sectional view of the access system of  FIG.  61    in the retracted state; 
         FIG.  63    is a perspective cross-sectional view of another embodiment of an access system; and 
         FIG.  64    is a cross-sectional view of a generally distal portion of the access system of  FIG.  63   . 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present disclosure relate generally to devices, systems, and methods for blood collection (also referred to as blood draws, blood aspiration, phlebotomy procedures, etc.). The blood collection can be achieved via an access system that includes a conduit or cannula that is inserted into a previously placed catheter, such as a catheter tube of a previously placed catheter, such as, for example, a previously placed peripheral intravenous (PIV) catheter. In certain embodiments, the access system can provide a desirable alternative to venipuncture. 
     In one context, fluid, particularly blood, is drawn from patients on a routine basis in many hospitals, clinics, and laboratories. One of the most common ways to draw blood is venipuncture, which is a method that involves inserting a needle through the skin and into an underlying vein to provide access to the patient&#39;s blood. In some instances, blood can be drawn as frequently as every six hours. Further, patients can be subjected to multiple attempts each time a needle is inserted into the skin, and the more frequent the withdrawals become, the more difficult it can become to find a location for the next withdrawal. Each attempt can be painful and a nuisance. Difficult intravenous access (DIVA) is a common problem that affects numerous patients. Other options for the withdrawal of blood and other fluids, however, are limited, and can often be even more painful than venipuncture. Some of these options include the use of peripherally inserted central catheters (PICC lines), central lines, repeated peripheral venipuncture, and groin sticks. 
     In some instances, blood may be drawn via a peripheral intravenous catheter at the time of insertion. In many instances, however, clots or fibrin sheaths can form at the tip of an intravenous catheter over time, so it is generally not desirable to draw blood from peripheral intravenous catheters, as previously designed, at any significant time after placement. In various instances, the obstructions that form at the distal tip can fully obstruct the distal tip, thereby entirely preventing withdrawal of blood through the catheter. In other instances, the obstructions may only partially obstruct the distal tip, but may affect fluid flow through the catheter in such a way as to promote hemolysis and/or otherwise reduce the quality of the blood withdrawn through the catheter and/or reduce a speed of the withdrawal. 
     In some instances, the intravenous catheter can lack sufficient rigidity to remain fully patent during a blood draw. For example, in some instances, the catheter is formed of a material that softens over time when within the patient vasculature. While blood draws may be possible upon initial placement of the catheter, blood draws may become increasingly difficult and ultimately impossible after the initial placement as the catheter softens. The catheter lumen may collapse when negative pressure applied at a proximal end of the catheter for an attempted blood draw, thereby inhibiting or preventing blood withdrawal. 
     In certain instances, even when blood is able to be withdrawn through a softened catheter, the quality of the drawn blood, relative to the quality of blood drawn immediately after placement of the catheter, may deteriorate as the catheter softens. Without being bound by theory, this quality reduction may be due to the lumen defined by the catheter becoming more tortuous or otherwise changing shape as the catheter softens. For example, upon initial placement, the catheter may have relatively few curves and/or regions of the catheter that extend through the skin and the vessel wall may define a rounded cross-sectional profile. Over time, the softening or softened catheter may become compliant so as to conform to tortuous anatomy through which it passes and/or the cross-sectional profile at the insertion regions may flatten or otherwise change shape. Blood drawn through these altered regions may, for example, be more susceptible to hemolysis. 
     In still other or further instances, an opening at the catheter tip may suction against a feature of the vessel anatomy, such as a valve or the vessel wall, during an attempted blood draw, thereby preventing blood withdrawal through the opening. 
     For one or more of the foregoing reasons, and/or for other possible reasons, it can be desirable to provide a conduit or cannula through a previously placed catheter (e.g., a PIV catheter) to achieve a high-quality blood draw through the catheter. The terms “conduit” and “cannula” may be used interchangeably herein. In some instances, the cannula can have sufficient rigidity to provide or maintain a patent lumen through which blood can readily pass. In other or further instances, the cannula can be readily inserted through tortuous path into and/or through a blood vessel. In other or further instances, the distal end of the cannula may be placed distally relative to the tip of the previously placed catheter, which may, for example, avoid interference from clots or fibrin sheaths; permit access to a region beyond an otherwise obstructing anatomical feature, such as by moving past one or more venous valves and/or away from a vessel wall; permit movement to a region of increased blood flow; and/or move away from a region of vascular trauma due to venipuncture and catheter insertion, any or all of which can result in substantially improved blood draws, such as, for example, by establishing blood flow and/or by reducing hemolysis of the sampled blood. 
     Certain embodiments disclosed herein can remedy, ameliorate, or avoid one or more limitations or drawbacks of known systems in which a catheter is inserted through a previously placed catheter for purposes of blood collection. One or more of these and/or other advantages will be apparent from the present disclosure. 
     For example, in some instances, a catheter is introduced into a patient, and subsequently, a cannula is introduced into the patient through the catheter. The catheter may be referred to herein as a placed catheter, a preplaced catheter, an anchor catheter, or a base catheter. The cannula may, in some instances, also be referred to as a conduit, a fluid channeler, a fluid extraction member, etc. In many instances, the cannula will have properties different from the placed catheter. For example, in some instances, at least a portion of the cannula may be stiffer or more rigid than the placed catheter. The cannula may, in some instances, define an open lumen or passageway through which blood can pass from the vessel and out of the patient through the cannula into any suitable blood collection device. The cannula may, in some instances, be reinforced so as to avoid buckling or kinking in order to readily enter and extend through a tortuous path of a lumen defined by the catheter. In some instances, the cannula may straighten or otherwise reduce a tortuousness of a path through a preplaced catheter system. In some instances, the cannula may be advanced past a distal end of the placed catheter. 
       FIGS.  1 A and  1 B  depict an embodiment of a base catheter system  100 , such as, for example, a peripheral intravenous (PIV) catheter system. The base catheter system  100  may also be referred to herein as a placed catheter system, a preplaced catheter system, an anchor catheter system, etc. The base catheter system  100  includes a catheter tube  104  and a catheter hub  106  that is fixedly secured to a proximal end of the catheter tube  104 . The base catheter system  100  can be inserted into a patient P in any suitable manner such that at least a distal end of the catheter tube  104  extends into a vessel V (e.g., a vein) of the patient ( FIG.  1 B ) and such that a proximal portion of the base catheter system  100 , including the catheter hub  106 , is accessible at an exterior of the patient. The catheter tube  104  can define a lumen  108  through which, for example, infusions may be delivered into the vessel V. The catheter hub  106  may be of any suitable variety. In some embodiments, the catheter hub  106  is a female luer connector. 
     While not shown in  FIG.  1 A , in many embodiments, the proximal portion of the base catheter system  100  that remains at an exterior of the patient P after placement of the catheter tube  104  can be secured to the skin of the patient. A variety of dressing options are possible, including tape or adhesive dressings that are specifically designed for such securement. As further discussed below, certain embodiments may be usable with the base catheter system  100  when the base catheter system  100  has been secured to the patient using a tape or adhesive dressings (e.g., a standard or known dressing), and, in further instances, may be usable with the base catheter system  100  without the use of any specialized apparatus (e.g., a wedge-shaped support member) that might couple with the base catheter system  100  to position the catheter hub  106  and the proximal end of the tube  104  at an angle relative to the surface of the skin, such as, e.g., at an acute angle similar to that shown in  FIG.  1 A . 
     In some embodiments, the base catheter system  100  can be an open catheter system, such as an open intravenous catheter system (e.g., an open PIV catheter system). The term “open” in this context is used in its ordinary sense in the relevant art, and includes catheter systems in which the connector  106  may not provide a barrier (e.g., a fluid-tight seal) between the lumen  108  and the environment external to the catheter hub  106 . For example, in the illustrated embodiment, the catheter hub  106  defines an open proximal end that is exposed to the environment. In some embodiments, a sealing member, such as any suitable valve, septum, or needleless connector, may be affixed to the catheter hub  106 . In other or further embodiments, an extension set (see, e.g.,  FIGS.  24  and  25   ) may be coupled with the catheter hub  106 . In certain embodiments (such as that depicted in  FIG.  24   ) the extension set can include a connector at a proximal end thereof, a connector at a distal end thereof for coupling with the catheter hub  106 , and a sideport therebetween with an extension tube and any suitable connector at a proximal end of the extension tube. In some instances, the proximal connector may include or be coupled with a valve, septum, or needleless connector. 
     As further discussed below, in other embodiments, the base catheter system  100  may instead be a “closed” catheter system, such as a closed intravenous catheter system (e.g., a closed PIV catheter system). An illustrative example of such a closed intravenous catheter system is depicted in, and discussed further below, with respect to  FIGS.  12 - 14   . The term “closed” in this context is used in its ordinary sense in the relevant art, and includes systems in which the catheter tube  104  is attached to a distal port of a catheter hub  106  that further includes a proximal port, from which an introducer needle can be withdrawn and thereupon sealed or plugged, and an integrated side port in fluid communication with the catheter tube  104 , via which fluid delivery and/or removal via the catheter tube  104  is achieved. One illustrative example of a closed PIV catheter system is the NEXIVA™ closed IV catheter system, available from Becton Dickinson. 
     With reference to  FIGS.  2 - 5   , in some embodiments, an access system  200  can be configured to couple with the base catheter system  100 . The access system  200  may also or alternatively be referred to as an access assembly. The illustrated access system  200  may be particularly well suited for coupling with and/or for operative use in advancing a conduit into an open base catheter system  100 , such as the illustrative system  100  depicted in  FIGS.  1  and  2   . In other or further instances, the access system  200  can be configured to couple with an extension set (e.g., such as that depicted in  FIG.  24   ) of an open base catheter system  100 , and can advance a conduit through the extension set and ultimately into the catheter tube  104 . The access system  200  can also be referred to as a fluid channeling system, a fluid extraction system, a blood removal system, a follow-on cannula system, a secondary catheter system, a supplemental catheter system, etc. 
     The base catheter system  100 , such as the catheter tube  104  thereof, can be inserted into a vessel of a patient in any suitable manner, including those known in the art. In some instances, no portion of the access system  200  is coupled with the base catheter system  100  prior to insertion of the base catheter system  100  into the patient. For example, the access system  200  may be coupled with the base catheter system  100  after the base catheter system  100  has been placed within the patient. In particular, one or more portions of the access system  200  may be coupled to the base catheter system  100  at any suitable time after placement of the base catheter system  100 . In some instances, the suitable time may be no less than 30 minutes, 1 hour, 6 hours, 12 hours, 18 hours, 1 day, 2 days, or 3 days after initial placement of the base catheter system  100 . 
     The access system  200  includes a connector  202  and a cannula  204 . The cannula  204  may also be referred to as a conduit. The cannula  204  can define a continuous fluid path through which blood can be extracted from the vasculature of a patient. The cannula  204  is configured to move relative to the connector  202  between a retracted or undeployed state ( FIGS.  2  and  3   ) and an advanced or deployed state ( FIGS.  4  and  5   ). In particular, a user can grip the cannula  204 —e.g., a proximal end of the cannula  204 —to distally advance (e.g., translate forwardly) the cannula  204  relative to the connector  202  from the retracted state to the advanced state. Likewise, the user can grip the cannula  204 —e.g., the proximal end of the cannula  204 —to retract proximally (e.g., translate rearwardly) the cannula  204  relative to the connector  202  from the advanced state back to the retracted state. For example, in some instances, the user can grip a connector  229  at a proximal end of the cannula  204  to advance and/or retract the cannula  204 . 
     The connector  202  can include a coupling interface  210 , which can be at a distal end of the connector  202 . In the illustrated embodiment, the coupling interface  210  includes a threaded male luer interface  211 , such as may readily couple with a female luer interface of the catheter hub  106  described above. Any other suitable coupling interface  210  is contemplated. 
     The connector  202  may be longitudinally elongated so as to be substantially tubular in shape. For example, in some embodiments, a distal end of the connector  202  may include a connection region  203  at a distal end thereof that defines the coupling interface  210 , and can further include a housing, barrel, tube, or sheath  205  that extends proximally from the connection region  203 . The sheath  205  can define an extended channel  212  ( FIG.  5   ), which may also be referred to as an inner chamber, cavity, or interior space, within which a portion of the cannula  204  may be positioned. For example, in various embodiments, at least some portion of the cannula  204  may be positioned within or internal to the sheath  205  when the cannula  204  is in the retracted state, the deployed state, and throughout transitioning between the retracted and deployed states. 
     With reference to  FIGS.  5  and  6   , in various embodiments, the cannula  204  can be a multi-part or multi-segment component. For example, in the illustrated embodiment, the cannula  204  is a three-segment element that defines a continuous or uninterrupted flow path or fluid path  220  for blood draws. In the illustrated embodiment, each segment is defined by a separate piece, with each piece being formed of one or more materials that are different from materials of one or more of the other two pieces. In other embodiments, two or more of the multiple segments (e.g., the proximal and medial segments) may be integrally formed of a unitary piece of material. In still other or further embodiments, each segment may include one or multiple components or constituent elements. In certain of these embodiments, either two or all three of the segments may have at least one component that differs in some manner from each of the remaining segments, such as, for example, by way of physical property, number, presence or absence, etc. The fluid path  220  can include a lumen  221 . In some embodiments, the lumen  221  can vary in diameter along a length of the cannula  204 . For example, in the illustrated embodiment, the lumen  221  defines a larger inner diameter in a proximal region of the cannula  204 , as compared to a distal region thereof. In other embodiments, the lumen  221  may define a substantially constant inner diameter along substantially a full length of the cannula  204 . 
     In some embodiments, the cannula  204  can include a proximal segment  222 , a middle, intermediate, or medial segment  224 , and a distal segment  226 , as identified in  FIG.  6   . In some embodiments, the materials and/or material properties of at least one of the segments can vary relative to that or those of one or more of the remaining segments. 
     In certain embodiments, the proximal segment  222  can be rigid or semi-rigid. The proximal segment  222  can be formed of a clear plastic, for example, which can allow for visualization of fluid flow. Rigidity of the proximal segment  222  can allow for the cannula  204  to be pushed distally relative to the connector  202 . In some embodiments, the proximal segment  222  can include the connector  229  at the proximal end thereof. The connector  229  can be of any suitable variety. For example, in the illustrated embodiment, the proximal segment  222  includes a connector  229  that is a female luer connector (i.e., compliant with ISO standards), which can be connected to any suitable any suitable fluid source and/or fluid collection device. For example, the connector  229  can be configured to couple with a syringe, which may be used for infusion or blood collection. The connector  229  may be used for connection to blood draw apparatus, such as syringes or evacuated blood collection tubes (e.g., Vacutainer® tubes available from Becton Dickinson) and/or apparatus therefor. For example, in some embodiments, the connector  229  may include or may be configured to connect with a Vacutainer® one-use holder, via which blood draws may be made into one or more Vacutainer® tubes. In other embodiments, the connector  229  may be integrally formed with a fluid source and/or a fluid collection apparatus. 
     In some embodiments, a valve or vent fitting may be removably attached to or incorporated into the proximal segment  222 . A vent fitting (such as, e.g., the vent fitting  819  depicted in  FIG.  12   ) can, for example, permit blood flow from the vasculature through the cannula  204  as air within the cannula lumen  221  is vented to the environment, and the vent fitting can serve as a liquid-impervious barrier to the blood. In some embodiments, the proximal segment  222  can allow visualization of an initial passage of blood through the lumen  221 , or stated otherwise, can provide blood flashback visualization. For example, when the proximal segment  222  includes a tube of clear or translucent material, the proximal segment  222  can allow for potential visualization of blood flashback. In various embodiments, the proximal segment  222  can include or be formed of a tube of polycarbonate, polyurethane, and/or polypropylene. Any other or further suitable material is contemplated. 
     In some embodiments, the proximal segment  222  may be flexible in transverse directions, relative to a longitudinal axis of the proximal segment  222 , yet may have sufficient rigidity in a longitudinal direction to transfer distal forces along the cannula  204 . For example, in some embodiments, the proximal segment  222  may be sufficiently flexible to bend up to about 90, 120, 150, or 180 degrees, e.g., without plastically deforming, yet can be straightened and advanced distally to advance the cannula  204  distally relative to the connector  202 . In some instances, the proximal segment  222  can be packaged in a bent state, which can permit reduction of a total length of packaging for a prepackaged access system  200 . A user can remove the access system  200  from the packaging and either manually unbend the proximal segment  222  or permit the proximal segment  222  to resiliently straighten to a relaxed state, which may be substantially rectilinear. Stated otherwise, in some embodiments, the proximal segment  222  may be resiliently deformable and may naturally unbend to a substantially straight configuration upon removal from the packaging. The user can advance the straightened proximal segment  222  through the proximal end of the sheath  203  to advance the cannula  204  distally relative to the connector  202 . 
     In other embodiments, the proximal segment  222  may be relatively rigid. The proximal segment  222  may have a rectilinear configuration, such as depicted in  FIG.  6   , and may be relatively resistant to lateral deformation from the rectilinear shape. For example, the proximal segment  222  may be preformed, packaged, and usable in the rectilinear shape, and in further embodiments, may be substantially resistant to deformations from the rectilinear shape. 
     In certain embodiments, the medial segment  224  of the cannula  204  can be stiff or rigid so as to avoid bending or kinking. The medial segment  224  can transfer distal forces from the proximal segment  222  to the distal segment  226 . In various embodiments, the medial segment  224  may include or be formed of metal, such as, for example, stainless steel. For example, in some embodiments, the medial segment  224  consists substantially of a metallic tube, such as a hypotube, that is coupled to the distal segment  226 . In other embodiments, the medial segment includes a metallic tube, such as a hypotube, that encompasses a portion of a polymeric tube that extends through a lumen of the metallic tube. Other or further suitable materials and/or configurations are also contemplated. 
     The proximal segment  222  and the medial segment  224  may be joined together in any suitable manner. For example, in various embodiments, the proximal segment  222  may be overmolded over a proximal end of the medial segment  224 . In other embodiments, the proximal and medial segments  222 ,  224  may be press-fit, friction-fit, adhered, or otherwise joined together, and may be fluidically sealed such that no leakage from the lumen  221  occurs at the interface between these two segments. 
     The distal segment  226  may be relatively soft or flexible so as to readily advance through the preplaced catheter  104 . For example, the distal segment  226  can be substantially softer and/or more flexible (e.g., can be laterally deflected much easier) than the medial segment  224 . For example, the distal segment  226  may be sufficiently soft or flexible to prevent or inhibit damage to the catheter tube  104  and/or, in certain embodiments, the blood vessel V (e.g., should the distal segment  226  be extended past the distal end of the catheter tube  104  and come into contact with the blood vessel V). Nevertheless, in various embodiments, the distal segment  226  may be sufficiently rigid to be advanced through the catheter tube  104 . In some embodiments, the distal segment  226  may render the catheter tube  104  straighter as the distal segment  226  is advanced therethrough. 
     In some embodiments, a distal tip  227  of the distal segment  226  includes one or more features that render the distal tip  227  atraumatic, or substantially atraumatic, relative to one or more of the preplaced catheter tube  104  and the patient vasculature. For example, in some embodiments, the distal segment  226  comprises a tube of polymeric material (e.g., polyimide). In some embodiments, the distal tip  227  of the tube is laser ablated so as to smooth and round the tip, thus rendering the distal tip  227  less prone to scraping, scratching, cutting, and/or puncturing an inner surface of the catheter tube  104  and/or a vessel within which the catheter tube  104  is positioned when the distal tip  227  extends from the catheter tube  104 . In other or further embodiments, the distal tip  227  can include a softer material attached to a distal end of the polymeric tube (e.g., a material with a lower durometer). For example, in some embodiments, a silicone layer may be positioned at the distal tip  227  in any suitable manner. 
     The distal segment  226  may be fully positioned within the catheter tube  104  when the cannula  204  is in the advanced state, such that the distal tip  227  is proximally recessed or generally flush with a distal tip of the catheter tube  104 , or the distal segment  226  may extend slightly beyond the distal tip of the catheter tube  104 , during a blood draw. The distal segment  226  can conform to a tortuous path of the vasculature and/or defined by the preplaced catheter system  100  when a portion of the catheter system  100  (i.e., at least a portion of the catheter tube  104 ) is positioned within the vasculature. The distal segment  226  can prevent damage to the catheter tube  104 , e.g., during advancement therethrough. For example, if the catheter tube  104  is sharply bent or kinked, the distal segment  226  can avoid puncturing through or scraping an interior of the catheter tube  104  at the bent or kinked site during distal advancement of the distal segment  226  through the catheter tube  104 . 
     In various embodiments, the distal segment  226  can include or be formed of polyimide, polyether block amide, silicone, polyamide, nylon, PEEK, and/or polyurethane. In other or further embodiments, the distal segment can comprise a siliconized polyurethane, such as one or more of the materials described in U.S. Patent Application Publication No. 2019/0153147 to Muse et al., the entire contents of which are hereby incorporated by reference herein. Any other or further suitable material is also contemplated. 
     In some embodiments, the distal segment  226  can have sufficient rigidity to at least partially straighten out the catheter tube  104  of the system  100  as the distal segment  226  is advanced through the catheter tube  104 . For example, in some embodiments, the distal segment  226  can have a stiffness that is greater than the stiffness of the catheter tube  104 . Straightening via the distal segment may, in some instances, facilitate blood withdrawal and/or permit laminar or substantially laminar blood flow through the cannula  204 . Stated otherwise, the distal segment  226  can provide a straight or straightened flow path, relative to a flow path that is defined by the preplaced catheter system  100  prior to use of the system  200 . For example, in some instances, the fluid path  220  through the deployed system  200  can be substantially straight or rectilinear, or can be gently sloped or gradually bent (e.g., without sharp turns or kinking) along the length of at least the distal segment  226  when the system  200  is deployed within the preplaced catheter system  100 . The distal segment  226 , or at least a distal portion thereof, can be sized to slide or otherwise be advanced through the lumen  108  of the catheter tube  104 . 
     In other embodiments, the distal segment  226  may be relatively softer than embodiments that might achieve significant straightening of a pre-placed catheter tube. In various embodiments, the distal segment may achieve a lower amount, a minimal amount, or even substantially no straightening of the preplaced catheter tube  104 . A relatively softer distal segment  226  may nevertheless be able to follow a tortuous path through the catheter system  100  while maintaining patency of the lumen  221  therethrough. In some embodiments, lateral support provided to the distal segment  226  by a reinforcement member included in the connector  202  and/or strength and kink-resistance afforded by the medial segment  224  can assist in advancing the distal segment  226  into the catheter tube  104 , as further discussed below. 
     The distal segment  226  may be joined with the medial segment  224  in any suitable manner. For example, in some embodiments, the medial segment  224  and the distal segment  226  are attached via a length of thin-walled heat shrink tubing (see, e.g.,  FIGS.  21  and  22   ). Such an attachment mechanism may be particularly useful, e.g., when the medial segment  224  includes a metal (e.g., stainless steel) tube and the distal segment  226  includes a polymeric tube that abuts the metal tube. Any other or further suitable attachment is contemplated. 
     In some embodiments, only the distal segment  226  is introduced into and passes through the preplaced catheter tube  104 . Stated otherwise, when the access system  200  is in a fully deployed state, the distal end of the medial segment  224  remains proximal to the proximal end of the catheter tube  104 , and at least a portion of the distal segment  226  extends into and/or through catheter tube  104 . As previously stated, in at least some embodiments, a distal end of the distal segment  226  can extend distally past a distal tip of the catheter tube  104  when the access system  200  is in the fully deployed state. 
     In other embodiments, the distal segment  226  may be relatively shorter and may function as a substantially atraumatic tip for the medial segment  224 , and at least a portion of the medial segment  224  may be introduced into the catheter tube  104 . In some embodiments, the medial segment  224  can provide a straightened path through at least a proximal portion of the catheter tube  104 . For example, the distal segment  226  can include any of the tip features previously discussed and may aid in preventing trauma to the catheter and the blood vessel, and the medial segment  224  can straighten out at least a portion of the catheter tube  104  of the system  100  as the medial segment  224  is advanced through this at least a portion of the catheter tube  104 . This straightening may facilitate blood withdrawal and/or achieve laminar or substantially laminar blood flow through the cannula  204 . Stated otherwise, in various embodiments, the medial segment  224 , whether alone or in combination with the distal segment  226 , can provide a straight or straightened flow path, relative to a flow path that is defined by the preplaced catheter system  100  prior to use of the system  200 . For example, the fluid path  220  through the deployed system  200  can be substantially straight or rectilinear, or can be gently sloped or gradually bent (e.g., without sharp turns or kinking) along the length of at least the medial segment  224  when the system  200  is deployed within the preplaced catheter system  100 . The medial segment  224 , or at least a distal portion thereof, can be sized to slide or otherwise be advanced through at least a portion of the lumen  108  of the catheter tube  104 . 
     In other embodiments, as further discussed below, the medial segment  224  may not extend into the catheter tube  104 . For example, in some embodiments, an outer diameter of the medial segment  224  is larger than an inner diameter of the catheter tube  104  and may be prevented from entering the proximal end of the catheter tube  104 . 
     With reference to  FIG.  7   , in some embodiments, the connector  202  includes a reinforcing member  230 , which may also or alternatively be referred to herein as a reinforcement member. In the illustrated embodiment, the reinforcing member  230  comprises a tubular member, such as a needle-like element or reinforcing cannula  232 . The reinforcing cannula  232  may also or alternatively be referred to herein as a reinforcing tube. In some embodiments, the reinforcing cannula  232  may be formed from a metallic hypotube. The reinforcing member  230  can provide external or lateral support to the distal segment  226  to prevent buckling and/or kinking of the distal segment  226  during forward advancement of the cannula  204 . For example, in various embodiments, the distal tip  227  of the distal segment  226  can encounter resistive forces as the distal segment  226  is advanced distally into the catheter tube  104 . In particular, during such distal advancement, distally directed forces can be provided to a proximal end of the distal segment  226  by the relatively stiffer or reinforced (e.g., axially or longitudinally strengthened) medial segment  224 , and the forces that are resistive to distal advancement of the distal segment  226  can tend to act in generally the opposite direction (e.g., generally proximally) at the distal end of the distal segment  226 . These generally oppositely directed forces can tend to compress the distal segment  226 , causing the distal segment  226  to buckle, bow, bend, kink, or displace laterally. The reinforcing member  230  can counter these lateral forces, thereby preventing buckling or kinking and facilitating insertion of the distal segment  226  into and through the catheter tube  104 . 
     The inner diameter of the reinforcing cannula  232  can be such that the outer diameter of each of the distal segment  226  and at least a distal portion of the medial segment  224  can fit therein. The fit may desirably be relatively close, such that there is minimal clearance between the inner surface of the reinforcing member  230  and the outer surface of each of the distal and medial segments  226 ,  224 . In various embodiments, an inner diameter (e.g., a maximum transverse dimension of an inner perimeter, circumference, and/or profile) of the reinforcement member  230  may be larger than an outer diameter (e.g., a maximum transverse dimension of an outer perimeter, circumference, and/or profile) of at least one of the distal and medial segments  226 ,  224  by no more than 5, 10, 15, 20, 25, or 30 percent. In certain embodiments, the cannula  204  can be said to slide through the reinforcing cannula  232  during advancement and withdrawal (e.g., transitions between the retracted and advanced states). 
     In the illustrated embodiment, the reinforcing cannula  232  fully covers or encompasses the distal segment  226  in the fully retracted state, which may also be referred to as the set, ready, initial, pre-deployed, or proximal state, position, orientation, or configuration. The deployed state may also or alternatively be referred to as an advanced, active, or distal state, position, orientation, or configuration. In some embodiments, a proximal tip of the distal segment  226  and a distal tip of the medial segment  224  may be positioned within the reinforcing cannula  232  when in the retracted state, as shown. 
     Stated otherwise, in some embodiments, the medial segment  224  can terminate at a distal terminus  250 , which may correspond with the distalmost tip of the medial segment  224 . In the illustrated embodiment, the medial segment  224  includes a tubular member having a substantially flat or planar transversely oriented face at the distal terminus  250 . This transverse face abuts a substantially flat or planer transversely oriented face at a proximal tip of a tubular member of the distal segment  226 . As previously discussed, in some embodiments, a heat shrink tube can extend over these abutting surfaces, which can join or assist in joining the medial and distal tubular members to each other. Stated otherwise, in some embodiments, the medial and distal segments  224 ,  226  are joined at an interface  252 , which in the illustrated embodiment, includes abutting surfaces of medial and distal tubes or tubular members. The heat-shrink tubing (see, e.g., feature  1080  in  FIGS.  21  and  22   ) can extend over these abutting surfaces at the interface  252 , or stated otherwise, can extend over the interface  252 . 
     With continued reference to  FIG.  7   , when the cannula  204  is in the retracted, initial, or set position, the distal terminus  250  and/or the interface  252  can be positioned within the reinforcement member  230 . This can ensure that the full length of the distal segment  226  is reinforced when the distal tip  227  begins to encounter resistance to distal advancement of the cannula  204 . For example, as shown in  FIG.  7   , in the illustrated embodiment, the distal tip  227  of the distal segment  226  of the cannula  204  is substantially flush with or slightly recessed relative to a distal tip of the reinforcing tube  232  when the cannula  204  is in the retracted position, and a proximal tip of the distal segment  226  is at the interface  252 , which is likewise positioned within the reinforcing tube  232 . Accordingly, as soon as the cannula  204  begins to advance distally, the distal tip  227  of the cannula  204  advances distally past the distal tip of the reinforcing tube  232  and may, in some instances, be susceptible to encountering resistive forces, such as by coming into contact with a portion of the pre-placed catheter tube  104  that is kinked, bent, curved, or otherwise poses resistance to passage therethrough. In such instances, by positioning the distal terminus  250  of the medial segment  224 , or stated otherwise, by positioning the interface  252  of the medial and distal segments  224 ,  226 , within the reinforcement member  230 , when the cannula  204  is in the fully retracted position, it can be ensured that the proximal end of the distal segment  226  is laterally supported by the reinforcement member  230  as soon as the distal tip  227  is exposed. Likewise, a full length of whatever portion of the distal segment  226  that remains within the reinforcement member  230  can be reinforced as the distal segment  226  is advanced distally out of the reinforcement member  230 . In certain embodiments, to achieve lateral support of the distal segment  226  as just described, a length of the reinforcement member  230 , and/or a length of the distal segment  226  that is positioned within the reinforcement member  230  when in the set position, can be greater than a distance between a distal tip of the reinforcement member  230  at a position at which the distal segment  226  initially encounters forces resistive to distal advancement as the distal segment  226  is deployed from the set position. 
     In other embodiments, the distal tip  227  of the distal segment  226  may be proximally recessed within the reinforcement member  230  by a more significant distance (e.g., by a length that is approximately equal to, or that is on the order of two, three, four or more times greater than, an outer diameter of the distal segment  226 ) when the cannula  204  is in the fully retracted position. In some embodiments, the interface  252  may be positioned proximal to a proximal end of the reinforcement member  230  when the cannula  204  is in the fully retracted position, whereas in other embodiments, the interface  252  may be positioned within the reinforcement member  230  when the cannula  204  is in the fully retracted position. In either case, in various embodiments, the interface  252  may desirably be positioned within the reinforcement member  230  when the distal tip  227  is first positioned distal of and external to the reinforcement member  230 . For example, when the cannula  204  is in the fully retracted position, the interface  252  may be positioned proximal to a proximal tip of the reinforcement member  230  by a distance that is less than or equal to a distance by which the distal tip  227  is recessed relative to a distal tip of the reinforcement member  230 . Thus, as the cannula  204  is advanced distally, the interface  252  may enter into the proximal end of the reinforcement member  230  at the same time as or earlier than the distal tip  227  exits distally out of the distal end of the reinforcement member  230 . 
     In certain embodiments, the medial segment  224  is sufficiently rigid to independently avoid buckling and/or kinking as the distal segment  226  is advanced through the reinforcing cannula  232  and into and through the preplaced catheter tube  104 . For example, an unsupported length of the medial segment  224 , relative to the reinforcing cannula  232  (e.g., a portion of the medial segment  224  that is external to the reinforcing cannula  232 ) can be self-supporting, intrinsically supported, or otherwise sufficiently rigid avoid buckling and/or kinking that might otherwise occur if the medial segment  224  were instead formed solely of the same material and geometric configuration as the distal segment  226 —e.g., if the medial and distal segments  224 ,  226  were formed of a continuous tube of a single material of uniform construction (e.g., uniform hardness, thickness, and diameter) and the medial segment  224  were not reinforced, or stated otherwise, if the medial segment  224  consisted solely of a continuous extension of the soft and/or flexible distal segment  226 . Whereas the medial segment  224  may be “unsupported,” such as by not having a reinforcing or support structure that is external thereto, the medial segment  224  may nevertheless be self-supported. For example, a portion of the medial segment  224  positioned proximal to the reinforcing member  230  may not be reinforced or supported by the reinforcing member  230 , but may nevertheless be intrinsically supported, e.g., due to its intrinsic rigidity. 
     For example, in order to transition the cannula  204  from the retracted position to the advanced or deployed position, distally directed forces are applied to the proximal segment  222  of the cannula  204 , or stated more generally, are applied to the proximal end of the cannula  204 . These distally directed forces tend to urge the medial segment  224  and the distal segment  226  distally. When the distal segment  226  encounters resistive forces to its distal advancement, these resistive or opposing forces are transferred proximally through the cannula  204 . Accordingly, during such advancement and resistance events, the medial segment  224  encounters opposing forces at its proximal and distal ends. These opposing or compressive forces could tend to bend, kink, or otherwise laterally deflect, e.g., intermediate regions of the medial segment  224  that are external to and unsupported by the reinforcement member  230 . However, the medial segment  224  can be configured to withstand deflection from the opposing or compressive forces. For example, as previously discussed, in some embodiments, the medial segment  224  is formed of a rigid material, such as stainless steel, that has sufficient intrinsic strength to resist the compressive forces without bending (or by bending by insignificant amounts) and/or without buckling or kinking. Stated otherwise, the medial segment  224  may be self-reinforced, internally reinforced, or intrinsically reinforced, such that a full length of the medial segment  224 , whether positioned within or without the reinforcement member  230 , may be said to be reinforced. 
     In other or further embodiments, the medial segment  224  may include a separate reinforcement or support component, such as a support tube, as discussed further below (see, e.g.,  FIGS.  56 A,  56 B, and  59    and accompanying text). For example, in some embodiments, the distal and medial segments  226 ,  224  may include a continuous polymeric tube of uniform properties and dimensions that spans a full length of each of the distal and medial segments  226 ,  224 . The medial segment  224  can additionally include a reinforcement or support tube that encompasses the polymeric tube. The support tube may have an inner surface that is only slightly larger than, is marginally larger than, and/or that closely conforms to an outer surface of the polymeric tube. For example, in various embodiments, an inner diameter (e.g., a maximum transverse dimension of an inner perimeter, circumference, and/or profile) of the support tube may be larger than an outer diameter (e.g., a maximum transverse dimension of an outer perimeter, circumference, and/or profile) of the inner polymeric tube by no more than 5, 10, 15, 20, 25, or 30 percent. As further discussed below, the support tube may be fixedly secured to and/or relative to the polymeric tube. 
     The support tube can have a distal end positioned within the reinforcement member  230  when the cannula  204  is in the retracted state. The support tube can slide within the reinforcement member  230  as the cannula  204  is advanced distally. As compressive forces arise at opposite ends of the inner polymeric tube during distal advancement thereof, the support tube can generally maintain a rectilinear profile of the portion of the polymeric tube that is positioned therein. Stated otherwise, the relatively stiffer support tube can resist deflection, bending, buckling, or kinking of the inner polymeric tube. As with embodiments discussed in the previous paragraph, the medial segment  224  can be said to withstand deflection from the opposing or compressive forces. For example, the support tube can be formed of a rigid material, such as stainless steel, that has sufficient strength to counter deflection of the inner polymeric tube as it encounters compressive forces that would tend to cause the polymeric tube to deflect, bend, buckle, or kink. The support tube can thereby prevent bending (or permit bending by insignificant amounts) buckling or kinking of the inner polymeric tube. Stated otherwise, the medial segment  224  may be self-reinforced or intrinsically reinforced, such that a full length of the medial segment  224 , whether positioned within or without the reinforcement member  230 , may be said to be reinforced. 
     In view of the foregoing discussion, at least a portion of the distal segment  226  can be reinforced when the cannula  204  is in the retracted state or set position, which reinforcement can be provided by the reinforcement member  230  of the connector  202 . Further, at least a portion of the medial segment  224  can be reinforced when the cannula  204  is in the retracted state or set position, which reinforcement can be provided intrinsically, such as by a tube of relatively stiff or rigid material that unitarily constitutes the medial segment  224  or such as by a tube of relatively stiff or rigid material that supports a length of a polymeric tube that is positioned within the relatively stiff tube in the region of the medial segment  224 . In further instances, at least a distal end of the medial segment  224  may be reinforced externally by the reinforcement member  230  when the cannula  204  is in the retraced state. Thus, more generally, a length of the cannula  204  that is positioned within the connector  202 , such as within the connection region  203  and the sheath  205 , can be reinforced. In various embodiments, a reinforced length of the cannula  204 , when in the retracted state, can be no less than 50, 60, 70, 80, or 90 percent of a total length of the connector  202 . In other or further embodiments, a reinforced length of the cannula  204 , when in the retracted state, can be no less than 50, 60, 70, 80, or 90 percent of a total length of the sheath  205 . In still other or further embodiments, a reinforced length of the cannula  204 , when in the retracted state, can be no less than 50, 60, 70, 80, or 90 percent of a length of the internal cavity  212  of the sheath  205 . In still other or further embodiments, a reinforced length of the cannula  204 , when in the retracted state, can be no less than 50, 60, 70, 80, or 90 percent of a distance between a proximal end of the reinforcement member  230  and a proximal end of the internal cavity  212  of the sheath  205 . 
     Moreover, in view of the foregoing discussion, a substantial length of the cannula  204  can be reinforced throughout movement of the cannula  204  from the retracted position to the fully deployed position. The reinforced length may vary throughout at least a portion of the deployment event, such as when increasing amounts of the distal segment  226  exit from the distal end of the reinforcement member  230 . In various embodiments, a reinforced length of the cannula  204  varies throughout at least a portion of a deployment event in which the cannula  204  is moved from the retracted state to the fully deployed state, and a minimum reinforced length of the cannula  204  throughout a full deployment event can be no less than 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, or 75 percent of a total length of the cannula  204 . The total length of the cannula  204  can be defined, for example, as a distance between the distal tip  227  of the cannula  204  and the proximal tip of the connector  229  (see  FIG.  6   ). In many embodiments, the minimum reinforced length may be achieved when the cannula  204  is in the fully deployed state. 
     With continued reference to  FIG.  7   , the reinforcing cannula  232  may be formed of any suitable material. For example, the reinforcing cannula  232  can include or be formed of stainless steel and/or rigid plastic. In some embodiments, the reinforcing cannula  232  can be formed of a metallic hypotube. The reinforcing cannula  232  may be attached to the connector  202  in any suitable manner, such as, for example, via press-fit, bonding, or overmolding. For example, in the illustrated embodiment, the connector  230  comprises a polymeric material that is overmolded onto the reinforcing cannula  232 . 
     In other embodiments, the reinforcing cannula  232  is omitted. For example, the reinforcing member  230  may instead be formed as a channel or lumen that extends through, e.g., a distal end of the connector  202 . In some embodiments, the distal end of the connector  202  may be molded or otherwise formed with additional material (e.g., polymeric material), as compared with what is shown in  FIG.  7   , through which the channel or lumen that forms the reinforcing member  230  extends. For example, in some embodiments, at least a portion of the distal end of the connector  202 , which includes the connection interface  210 , may be extended longitudinally in the proximal direction to define an elongated reinforcing member  230 . This alternative reinforcing member may, for example, have the same length as that of the reinforcing tube  232  depicted in  FIG.  7   , but may instead be formed from additional polymeric material with a lumen extending therethrough. 
     With reference again to  FIGS.  5  and  6   , in some embodiments, the system  200  can include a friction or resistance element  240 , which can resist, regulate, temper, adjust, or otherwise passively respond to relative movement of the connector  202  and the cannula  204 . In the illustrated embodiment, the resistance element  240  comprises an O-ring  242  that is received within an annular channel  244  defined by the proximal segment  222 . The O-ring  242  can slide along an inner surface of the connector  202 . Any other suitable resistance mechanism is contemplated, such as a saw tooth, ratchet, or other interface between the proximal segment  222  and the connector  202 . In other or further embodiments, the resistance element  240  can include friction grease in addition to or instead of other resistance elements that regulate relative movement of the connector  202  and the cannula  204 . 
     As previously discussed, in various embodiments, the connector  202  can be configured to couple with an open catheter system and/or a closed catheter system. In some embodiments, the connector  202  may be attached directly to a catheter hub of an open catheter system, while in other embodiments, the open catheter system can include an extension set attached to the catheter hub, and the connector  202  can be attached to a port of the extension set. 
     With reference again to  FIG.  7   , in some embodiments, the reinforcement member  230  includes a protrusion or projection  213  that extends distally from a surface  217  (e.g., a distally facing surface) of the connector  202 . The surface  217  may also be referred to as a bottom surface or as a recessed, inner, or internal surface of the connection region  203  of the connector  202 . The inner and internal surface descriptors arise from the recessed relationship of the surface  217  relative to adjacent portions of the connector  202 , such as relative to a threaded skirt  215  and a central male luer, although the surface  217  is an overall exterior of the connector  202 . In the illustrated embodiment, the projection  213  includes the central male luer, which is formed of polymeric material, and within which a distal portion of the reinforcing tube  232  is positioned. Stated otherwise, the projection  213  includes a distal end of the reinforcing tube  232  encompassed by other material (e.g., polymeric material) that projects distally from the recessed surface  217 . In some embodiments, the projection  213  can be coupled directly with an open hub (e.g., the catheter hub  106  in  FIG.  1   ), such as to engage the hub in a fluid-tight seal (e.g., via luer interfaces). The projection  213  can be configured to open or otherwise defeat a valve, septum, or the like of a hub or of an extension set coupled to the catheter hub  106 , which can permit fluid communication between the catheter tube  104  and the cannula  204 . In the illustrated embodiment, the projection  213  extends distally from a bottom surface  217  of the connection interface  211 . The connection interface  211  further includes the threaded skirt  215 , which may comply with ISO standards for luer fittings. The skirt  215  may include a distal edge  219 , which can correspond with a distalmost end or tip of the connector  202 . In the illustrated embodiment, the projection  213  extends distally beyond the distal edge  219  of the connector  202 . 
     The coupling interface  210  of the connector  202  can be of any suitable variety. For example, the coupling interface  210  can include threading  225 , such as for luer lock interfacing. Similar threading  525 ,  625  is depicted in  FIGS.  10  and  11   . In other embodiments, the coupling interface  210  can utilize friction fit or other mechanical engagement (e.g., snap fit). Illustrative examples of friction-fit interfaces are identified as the features  328  and  428  in  FIGS.  8  and  9   , respectively. An illustrative snap-fit coupling interface is depicted, e.g., in  FIG.  32 A , as further discussed below. 
     In various embodiments, the reinforcement member  230  and/or the reinforcing cannula  232  may be flush with the inner, recessed, bottom, or distal-facing surface  217  of the connector  202 . For example, in the embodiment depicted in  FIG.  8   , a distal end of a reinforcing cannula  332  is encompassed by or encased in a material that forms a connector  302 . 
     In other embodiments, such as previously discussed, the reinforcement member  230  and/or the reinforcing cannula  232  may project distally from a distally facing surface of the connector  202 , such as from the inner, recessed, bottom, or distal-facing surface  217  of the coupling interface  210 . In this manner, the reinforcing reinforcement member  230  and/or the reinforcement cannula  232  can pierce or otherwise defeat valves, stops, etc. of a preplaced catheter system as the connector  202  is coupled to the preplaced catheter system. For example, a catheter hub of a preplaced catheter system may include a septum or a valve that can be pierced, compressed, or otherwise opened by the reinforcement member  230 . For example, as previously discussed, the projection  213  of the embodiment depicted in  FIG.  7   , which includes a distal end of the reinforcement cannula  232  therein, may be configured to open or defeat a valved member of the preplaced catheter system—for example, may defeat a valve associated with the catheter hub  106  (see  FIG.  1   ) in some instances, and/or may defeat a valve associated with an extension set (see, e.g.,  FIG.  24   ) coupled with the catheter hub  106 . 
     With reference to  FIGS.  9  and  11   , the distal end of reinforcement members  430 ,  630 , which define projections  413 ,  613 , may be formed solely by distal ends of reinforcement cannulas  432 ,  632  that project distally from bottom, inner, recessed, or distally facing surfaces  417 ,  617 , respectively. Each reinforcement cannula  432 ,  632  can be inserted through a valve as its respective connector  402 ,  602  is coupled with a preplaced catheter system (whether directly to a catheter hub or to a hub of an extension set), in some instances. In other instances, as discussed below, the reinforcement cannulas  432 ,  632  can be dimensioned such that the distal tip of the reinforcement cannula  432 ,  632  is instead positioned at, adjacent to, or slightly proximally recessed from a proximal surface of a valve member as the associated connector  402 ,  602  is attached to a preplaced catheter system. As further discussed below, in certain of such embodiments, the respective cannula  404 ,  604  can be advanced distally to pierce through the valve member while being reinforced by the distal projection of the reinforcement cannula  432 ,  632 . 
     With reference again to  FIGS.  5 - 7   , in some embodiments, the cannula  204  can be formed of fewer than three distinct pieces or fewer than three separate segments. For example, in some embodiments, the cannula  204  can include a distal segment  226 , such as that previously disclosed, coupled to a rigid tube that extends proximally to the connector  229  (e.g., luer connector) at a proximal end of the cannula  204 . Stated otherwise, the medial segment  224  may be extended proximally so as to replace an elongated portion of the proximal segment  222 . In some instances, the rigid tube is a metallic tube, such as stainless steel. In further instances, the rigid tube abuts a polymeric tube that forms the distal segment  226 , as previously discussed. For example, the polymeric tube of the distal segment  226  and the stainless steel tube of the medial segment  224  can abut at an interface and be connected to each other via heat shrink tubing. 
     In other instances having an elongated medial segment  226  in place of the proximal segment  222 , a polymeric tube may extend continuously along both the distal and medial segments  226 ,  224 . The rigid tube of the medial segment  224  may encompass that portion of the polymeric tube that extends proximally from the distal segment  226 . Stated otherwise, in some embodiments, a single polymeric tube (e.g., of polyimide) may extend continuously from the distal tip  217  of the cannula  204  to the proximal connector  229 . A second tube, such as the support tube previously described, can sheath a portion of the polymeric tube and extend from the interface  252  all the way proximally to the proximal connector  229 . Stated in yet another manner, the cannula  204  can include (1) a distal segment  226 , formed solely of a polymeric tube extending distally from the interface  252  to the distal tip  217  of the cannula  204 , and (2) a medial segment  224 , formed of a continuous proximal extension of the polymeric tube and a second rigid support tube that sheaths or encompasses the proximal extension of the polymeric tube, with each of said continuous proximal extension of the polymeric tube and the support tube extending proximally from the interface  252  and terminating at the proximal connector  229 . 
     In still other embodiments, the rigid tube of the medial segment  224  may be extended proximally through an interior of the proximal segment  222 . Stated otherwise, the proximal segment  222  may include a diametrically larger piece (e.g., of plastic) that encases a proximal portion of the medial segment  224 . In some embodiments, the rigid cannula (e.g., which may be metallic) of the medial segment  224  may extend proximally to the connector  229 . 
     The proximal segment  222  has been described herein as a portion of the cannula  204 . The elongated molded piece that forms the illustrated proximal segment  222  may alternatively be described as an elongated proximal connector  229  (e.g., an elongated luer connector) that extends distally. That is, the proximal segment  222  may be viewed as a distal extension of the connector  229 . 
       FIG.  8    depicts a distal portion of another embodiment of an access system  300 , which can resemble other access systems disclosed herein, such as, for example, the access system  200 . Accordingly, features of the access system  300  are designated with reference numerals similar to those of the access system  200 , with the leading digit “2” being replaced with “3.” Relevant disclosure set forth above regarding similarly identified features thus may not be repeated hereafter. Moreover, specific features of the access system  300  may not be shown or identified by a reference numeral in the drawings or specifically discussed in the written description that follows. However, such features may clearly be the same, or substantially the same, as features depicted in other embodiments and/or described with respect to such embodiments. Accordingly, the relevant descriptions of such features apply equally to the features of the access system  300 . Any suitable combination of the features and variations of the same described with respect to the access system  200  can be employed with the access system  300 , and vice versa. Similarly, the access system  300  can suitably be used within the base catheter system  100  and other preplaced catheters and catheter systems described herein. That is, disclosures regarding various access systems  300  can be appropriately applied to other access systems described herein, in the interest of streamlining the present discussion. This pattern of disclosure applies equally to further embodiments depicted in the various figures and described herein, wherein the leading digits may be further altered. 
     As previously mentioned, the access system  300  includes a connection interface  310  that has a friction-fit arrangement, rather than threading. A distal tip of a reinforcement tube  332  is flush with an inner surface  317  of the connection interface  310 . 
     In the illustrated embodiment, a cannula  304  is shown in a retracted orientation. In this orientation, a distal tip  327  of the cannula  304  is recessed slightly from a distal tip of the reinforcement tube  332 . 
       FIG.  9    depicts another embodiment of an access system  400  that includes a connector  402  having a connection interface  410  that likewise has a friction-fit arrangement. The projection  413  is defined by a distal end of a reinforcement tube  432  that extends distally from an inner or recessed surface  417  of the connection interface  410 . In the illustrated embodiment, a distal tip of the reinforcement tube  432  is proximally recessed relative to a distal edge  419  of the connector  402 . 
     In the illustrated embodiment, when a movable cannula  404  is in a retracted position, a distal tip  427  of the cannula is substantially flush with a distal tip of the reinforcement tube  432 . In this retracted orientation, the distal tip  427  of the cannula  404  is distally spaced from the inner or recessed surface  417  and is proximally spaced from the distal edge  419  of the connector  402 . 
     As previously discussed,  FIGS.  10  and  11    depict additional embodiments of access systems  500 ,  600  that resemble the access systems  300 ,  400 , respectively. The access systems  500 ,  600  have connectors  502 ,  602  having connection interfaces  510 ,  610  that include threading  525 ,  625 . The access systems  500 ,  600  include reinforcement members  530 ,  630  that include reinforcement tubes  532 ,  632 . 
     In some embodiments, the access systems  300 ,  400 ,  500 ,  600  can be particularly well suited for coupling with closed intravenous catheter systems. As further discussed below, in some embodiments, the reinforcement tubes  332 ,  432 ,  532 ,  632  may be spaced from an outer septum or cover of the closed IV catheter system. In other embodiments, the reinforcement tubes  332 ,  432 ,  532 ,  632  can be dimensioned to extend through the outer septum or cover of the closed IV catheter, but a distal tip thereof may (1) be at or proximally spaced from a proximal surface of a valve (or plug or inner septum), (2) not extend through the valve, and/or (3) not contact the valve, as discussed further below. 
       FIG.  12    is a perspective view of an embodiment of a closed catheter system  700 , which may also be referred to herein as a closed base catheter system  700 . Any suitable closed catheter system is contemplated, such as, for example, a closed intravenous catheter system. For example, the closed base catheter system  700  can comprise any of the NEXIVA™ lines of catheters (e.g., the DIFFUSICS™ line) available from Becton Dickinson. Certain of such closed catheter systems may have an extension set  802  integrated therein. For example, in the illustrated embodiment, a hub  806  of the extension set  802  includes a side port  813  with an extension tube  817 , a connector  818 , and a removable vent fitting  819 , similar to extension set arrangements that may be used with open intravenous catheter assemblies (e.g., such as the extension set depicted in and described with respect to  FIG.  24   ). The hub  806  may also be referred to as a catheter hub. 
     The closed catheter system  700  can include a removable needle assembly  721  that includes a needle  720  connected to a needle hub  722 . The needle assembly  721  can be coupled with the catheter hub  806  and used during insertion of a catheter tube  704  into the vasculature of a patient, and can be removed from the catheter hub  806  thereafter. The needle  720  and its two-part hub  722  can be inserted into the catheter hub  806  and the catheter tube  704  during assembly of the closed catheter system  700 , and can be packaged in such a preassembled configuration, such as that depicted in  FIG.  12   . 
     In  FIG.  12   , the catheter system  700  is shown in an insertion configuration. The needle  720  extends from a distal tip of the catheter  704  to permit insertion of the catheter tube  704  into the vasculature of a patient. 
       FIG.  13    is a perspective view of the closed catheter system  700  in a disassembled state, such as may be achieved after the catheter tube  704  has been inserted into a blood vessel of a patient. The needle assembly  721  is shown as having been removed from the hub  806  and catheter tube  704 . The illustrated configuration may be referred to as an access configuration. For example, once the catheter tube  704  has been positioned within the vasculature of the patient in any suitable manner, including those presently employed, and once the needle assembly  721  has been removed, access to the vasculature may be achieved via the placed catheter tube  704 . For example, the vent fitting  819  may be removed at any suitable stage, and a fluid source or fluid receptacle may be coupled with the connector  818  if the integrated extension set  802  to achieve fluid delivery to the vasculature and/or fluid removal from the vasculature via the catheter tube  704 . 
     The needle  720  can be fixedly attached to the needle hub  722 . In the illustrated embodiment, the needle hub  722  is a two-part hub that provides shielding capabilities to a distal tip of the needle  720  to avoid needle sticks when the needle  720  is withdrawn from the catheter hub  806  after the catheter tube  704  has been introduced into the vessel of the patient. 
       FIG.  14    is a cross-sectional view of the catheter hub  806  and the catheter tube  704  of the closed catheter system  700  in an operational state in which the needle  720  has been fully removed from the catheter tube  704  and from the catheter hub  806 . The catheter hub  806  can include a distal port  807  in fluid communication with the catheter tube  704 , a proximal port  809  that is described below, and the side port  813  of the integrated extension set  802 , to which the extension tube  817  and connector  818  ( FIG.  12   ) are coupled. Each of the distal and side ports  807 ,  813  is in continuous fluid communication with an inner chamber  810 . 
     Certain embodiments of access systems (e.g., the access systems  300 ,  400 ,  500 ,  600 ), or portions thereof, such as any suitable access system, or portion thereof, disclosed herein can be used with the closed catheter system  700  while in the operational state—namely, the access state—depicted in  FIG.  14   , in which the needle assembly  721  has been removed. In certain embodiments, the access systems (e.g.,  300 ,  400 ,  500 ,  600 ) may not include their own extension sets (e.g., such as the extension set depicted in  FIG.  24   ), as the catheter hub  806  of the closed base catheter system  700  already includes an extension set integrated therein. In some embodiments, the distal connection interfaces of the access systems  300 ,  400 ,  500 ,  600  depicted in, e.g.,  FIGS.  8 - 11    may be particularly well-suited for interfacing with the closed catheter system  700 . For example, friction-fit or snap-fit connectors may connect well with certain embodiments of the proximal port  809 . 
     With continued reference to  FIG.  14   , the proximal port  809  can include a plurality of components coupled thereto or therein. In particular, the proximal port  809  can include an outer or proximal septum or cover  851 , an inner or distal septum or plug  852 , and a retainer  853 . In various embodiments, the septa  851 ,  852  may be formed of any suitable elastomeric materials. The retainer  853  may be formed of a relatively rigid polymeric material and may interface with a polymeric housing of which the catheter hub  806  is formed to retain the septa  851 ,  852  within the proximal port  809 . 
     In typical or standard use of the closed catheter system  700 , the needle  720  ( FIGS.  12  and  13   ) extends through the retainer  853  and the septa  851 ,  852  of the proximal port  809 , through the catheter hub  806 , and through the catheter tube  704  when the closed catheter system  700  is in the insertion configuration. The needle  720  may more generally be referred to as a piercing member or as a piercing implement. For example, in other embodiments, the needle  720  may be replaced with any other suitable piercing member or piercing element, such as, for example, a trocar. The proximal port  809  may also be referred to as an implement port. 
     Upon placement of the catheter tube  704  within a vessel of the patient, the needle  720  is fully removed, thus placing the closed catheter system  700  in the access state depicted in  FIG.  14   . As the needle  720  is removed from the inner septum, distal septum, or plug  852 , the plug  852  self-seals to close off the proximal end of the inner chamber  810  and prevent fluid communication between the inner chamber  810  and the proximal port  809 . In typical or standard use, the proximal port  809  is no longer used, and all further fluid communication with inner chamber  810  and/or the catheter  704  is achieved vie the integrated extension set  802 , or stated otherwise, via the side port  813 . The plug  852  is not used in any further access events, and desirably remains sealed for the remaining use of the closed catheter system  700 . 
     As previously discussed, and as further discussed hereafter, certain embodiments of access systems are able to interface with the proximal port  809  in an atypical fashion by coupling with the proximal port  809  and passing a cannula (e.g.,  304 ,  404 ,  504 ,  604 ) through the plug  852  and into the catheter tube  704 . Through this process, the cannula (e.g.,  304 ,  404 ,  504 ,  604 ) can, upon passing through the plug  852 , achieve fluid communication with the inner chamber  810  and/or the catheter tube  704 . Moreover, when the cannula (e.g.,  304 ,  404 ,  504 ,  604 ) extends through the plug  852 , fluid is able to pass through the cannula, and hence is able to pass through the plug  852  and, more generally, through the proximal port  809 . Moreover, in some instances, multiple access events through the plug  852  in this manner are possible. The plug  852  can again self-seal upon removal of the cannula (e.g.,  304 ,  404 ,  504 ,  604 ). Accordingly, due to the ability to use the distal septum or plug  852  to selectively achieve fluid communication between (1) the catheter tube  704  and/or the inner chamber  810  of the catheter hub  806  and (2) an exterior of the closed catheter system  700  via the proximal port  809 , the distal septum or plug  852  may additionally or alternatively be referred to herein as a valve or valve member  852 . Further, the distal septum, plug, valve, or valve member  852  may also or alternatively be referred to as a seal or sealing member. 
     In view of the foregoing, the septa  851 ,  852  and the retainer  853  may be described in additional or alternative terms. For example, it may be said that the proximal port  809  includes a valve assembly  850  that can permit selective fluid communication between the inner chamber  810  and the proximal port  809 . In some instances, the valve assembly  850  is configured to fluidically seal against the needle  720  when the needle  120  is fully inserted therethrough, such as in the insertion configuration depicted in  FIG.  12   , and is configured to self-seal so as to prevent fluid from egressing from the inner chamber  810  and through the proximal port  809  upon removal of the needle  720  therefrom to achieve the access configuration depicted in  FIG.  13   . 
     With continued reference to  FIG.  14   , the valve assembly  850  of the proximal port  809  can include the proximal septum  851 , the distal septum  852 , and the retention member or retainer  853 . The retainer  853  can comprise a generally tubular element that interfaces with a body of the catheter hub  806  to retain the proximal and distal septa  851 ,  852  within the proximal port  809 . That is, the retainer  853  may cooperate with a housing portion of the hub  806  to hold the septa  851 ,  852  in place within the proximal port  809 . Although the illustrated valve assembly  850  includes multiple septa  851 ,  852 , only the distal septum  852  may provide the valving functionality of the valve assembly  850  discussed above, and further discussed below. 
     In some embodiments, the proximal septum  851 , which is also or alternatively referred to as a cover, includes an opening  854 , which may be centered relative to the port  809 . The opening  854  may be a permanent opening. When the closed catheter system  700  is in the insertion state depicted in  FIG.  12   , the needle  720  can extend through the opening  854  of the proximal septum  851 . The opening  854  may be preformed and/or may be sufficiently large such that the opening  854  does not self-seal upon removal of the needle  720  therefrom. 
     The retainer  853  can include an opening  855 , which can be larger than the opening  854  of the proximal septum  851 . The opening  855  can be concentric with the opening  854 . 
     As previously noted, the valve  852  may be self-sealing, such that upon removal of the needle  720  therefrom, a sealable region  856 , which may also or alternatively be referred to as a “closable opening” (as opposed to the permanent opening  854  of the proximal septum  851 ), self-seals to prevent fluid communication between the chamber  810  and the port  809 . In some embodiments, a fluid-tight seal formed by the closable opening or sealable region  856  is sufficiently strong to withstand high pressures, such as may be achieved when power injection is performed via the side port  813  to pass fluid through the inner chamber  810  and the distal port  807 . 
     In certain embodiments, when an access system (e.g., either access system  400 ,  600 ) is coupled with the proximal port  809  of the closed catheter system  700 , a reinforcement member of the access system (e.g., the reinforcement member  430 ,  630  of the access system  400 ,  600 , respectively) can extend through the openings  855 ,  854  of the retainer  853  and the proximal septum  851 , respectively, and a distal tip of the reinforcement member (e.g., the distal tip of the reinforcement tube  432 ,  632 ) may be positioned at or proximally recessed from a proximal surface of the distal septum or valve  852 . One such illustrative coupling event and coupling configuration are depicted in  FIGS.  33  and  34   , respectively, which is discussed further below. The distal tip of the reinforcement member (e.g.,  430 ,  630 ) may be fixed in this position relative to the valve  852 . The reinforcement member (e.g.,  430 ,  630 ) can thereby align a movable/deployable cannula (e.g.,  404 ,  604 ) of the access system with the valve  852 . Stated otherwise, a longitudinal axis of the reinforcement tube (e.g.,  432 ,  632 ) can be centered on and colinear with a line that extends through the sealable region  856  of the valve  852 , which line corresponds to a sealed tract from which the needle  720  has previously been removed (this may also be referred to as a needle tract through the sealable region  856 ). The reinforcement member (e.g., the reinforcement tube) does not contact the valve  852  or extend into or through the valve  852 . Rather, the cannula (e.g.,  404 ,  604 ) of the access system is extended out of the reinforcement member (e.g., the reinforcement tube  432 ,  632 ) and then through the sealable region  856  of the valve  852 . 
     In still other embodiments, when an access system (e.g., either access system  300 ,  500 ) is coupled with the proximal port  809  of the closed catheter system  700 , a reinforcement member (e.g.,  330 ,  530 ) of the access system (e.g.,  300 ,  500 ) can remain external to, recessed from, or otherwise not extend through the openings  855 ,  854  of the retainer  853  and the proximal septum  851 , respectively. A distal tip of the reinforcement member (e.g., the distal tip of the reinforcement tube  332 ,  532 ) may be proximally recessed from a proximal surface of the distal septum or valve  852 . Indeed, the distal tip of the reinforcement member (e.g., the distal tip of the reinforcement tube  332 ,  532 ) may sufficiently recessed from the valve  852  so as to also be at or proximally recessed from a proximal surface of the cover or proximal septum  851 . The distal tip of the reinforcement member (e.g.,  330 ,  530 ) may be fixed in this position relative to the valve  852 . The reinforcement member (e.g.,  330 ,  530 ) can align a movable/deployable cannula (e.g., the cannula  304 ,  504 ) of the access system with a longitudinal axis of the valve  852 . Stated otherwise, a longitudinal axis of the reinforcement tube (e.g.,  332 ,  532 ) can be centered on and colinear with the line through the sealable region  856  of the valve  852  that corresponds to a sealed tract from which the needle  720  has previously been removed (e.g., the needle tract through the sealed region  856 ), as previously described. An imaginary extension of this line in the proximal direction can extend through the openings  855 ,  854  of the retainer  853  and the proximal septum  851 , respectively, and be aligned with the longitudinal axis of the reinforcement tube. The reinforcement member (e.g.,  330 ,  530 ), or in certain embodiments, the reinforcement tube (e.g.,  332 ,  532 ) does not contact the valve  852  or extend into or through the valve  852 . Rather, the cannula (e.g.,  304 ,  504 ) of the access system is extended out of the reinforcement member (e.g.,  330 ,  530 ), then through the proximal septum  851 , and then through the sealable region  856  of the valve  852  along a substantially rectilinear path. 
     In certain embodiments, the distal end of the deployable cannula (e.g., any of the cannulae  304 ,  404 ,  504 ,  604  of the access systems  300 ,  400 ,  500 ,  600 ) can successfully be extended through the valve  852  without damaging or kinking the cannula (e.g.,  304 ,  404 ,  504 ,  604 ) and without damaging the valve  852 . In some instances, by avoiding contact of the reinforcing tube with the valve  852 , or by not embedding the reinforcing tube within the valve  852 , during an insertion or deployment event, the material of the valve  852  remains in a more relaxed state, or stated otherwise, is in a less compressed or less stressed state, or may be in a fully uncompressed or unstressed state, which can facilitate insertion of the movable cannula (e.g.,  304 ,  404 ,  504 ,  604 ) therethrough. Moreover, as previously noted, in some instances coupling the access system (e.g.,  300 ,  400 ,  500 ,  600 ) with the proximal port  809  can center the reinforcement member (e.g.,  330 ,  430 ,  530 ,  630 ) relative to the valve  852  and thereby align the cannula (e.g.,  304 ,  404 ,  504 ,  604 ) with the valve  852 , such that the cannula (e.g.,  304 ,  404 ,  504 ,  604 ) can be inserted along the same path through the valve  852  or through the same portion of the valve  852  from which the needle  720  has previously been removed (e.g., the needle tract through the sealable region  856 ), which may facilitate or enable insertion of the cannula (e.g.,  304 ,  404 ,  504 ,  604 ) through the valve  852 . In certain embodiments, reinforcement features as described elsewhere herein, can make such insertion of only the cannula (e.g.,  304 ,  404 ,  504 ,  604 ) through the valve  852  possible. In some instances, if the cannula is not reinforced at more proximal regions thereof, the cannula may bend or kink upon contact with the valve  852 , which can prevent insertion of the cannula through the valve  852 . 
     In some instances, it may be advantageous to not insert a reinforcement tube (e.g., either reinforcement tube  432 ,  632  of the access systems  400 ,  600 ) or any portion thereof into the valve  852  in order to thereafter advance the cannula (e.g.,  404 ,  604 ) through reinforcement tube to thereby achieve passage of the cannula through the valve. As previously noted, maintaining the reinforcement tube (e.g.,  432 ,  632 ) external to the valve  852  (or proximally recessed from a proximal surface of the valve  852 ) prior to and during insertion of the cannula (e.g.,  404 ,  604 ) through the valve  852  can maintain the valve  852  in a relatively relaxed or uncompressed state, which can facilitate distal movement of the cannula (e.g.,  404 ,  604 ) through the valve  852 . In other or further instances, damage to the valve  852 , such as coring of the valve  852  by a distal tip of the reinforcement tube (e.g.,  432 ,  632 ) and/or permanent stretching or deformation of the valve  852  by a relatively larger outer diameter of the reinforcement tube (e.g.,  432 ,  632 ), can be avoided. 
     Stated otherwise, as can be appreciated from the present disclosure, in certain instances, it can be advantageous to advance the cannula through the valve  852  without first inserting a separate supporting or reinforcing member into or through the valve  852  (e.g., a reinforcing member of a larger diameter that could stretch out or deform the valve  852  and/or of a variety which could undesirably core a portion of the valve  852  upon passage therethrough). That is, it can be advantageous to advance the cannula through the valve  852  independently, on its own, or without doing so through a separate member (e.g., reinforcement or support member) that has previously been advanced into or through the valve and that remains positioned in or through the valve so as to define an open channel (e.g., corresponding to the inner lumen of the support member) through at least a portion of the valve for subsequent passage of the cannula. 
     In some instances, after an access system (e.g.,  300 ,  400 ,  500 ,  600 ) has been used with the closed catheter system  700  and removed therefrom, the valve  852  can remain sealed during subsequent use of the integrated extension set  802 . Stated otherwise, use of an access system (e.g.,  300 ,  400 ,  500 ,  600 ) with the closed catheter system  700  can have no adverse effect on operation of the valve  852 , or can preserve effective or normal operation of the valve  852 . Stated otherwise, use of the access system with closed catheter system  700  can, upon removal of the access system, permit the inner septum  852  to once again plug or seal the proximal port  809 . For example, in some instances, after removal of a deployable cannula (e.g.,  304 ,  404 ,  504 ,  604 ) from the catheter tube  704  and from the distal valve  852  of the closed catheter system  700  after use of an access system (e.g.,  300 ,  400 ,  500 ,  600 ) therewith, the integrated extension set  802  of the closed catheter system  700  can be used to access the vasculature of the patient (e.g., for an infusion or aspiration event) via the placed catheter tube  704  in the same manner as may have been accomplished prior to use of the access system (e.g.,  300 ,  400 ,  500 ,  600 ) with the closed catheter system  700 . In some instances, the valve  852  remains sufficiently strong and fluid-tight to permit use of the closed catheter system  700  for power injections through the side port  813  after removal of the access system (e.g.,  300 ,  400 ,  500 ,  600 ). In certain embodiments, use of an access system (e.g.,  300 ,  400 ,  500 ,  600 ) with the closed catheter system  700  has no adverse effect on the valve  852 , such that after 1, 2, 3, 4, 5, 10, 15, 20, or 25 or more coupling and decoupling cycles of one or more access assemblies (e.g.,  300 ,  400 ,  500 ,  600 ) with and from a closed catheter system  700 , the valve  852  of the closed catheter system  700  continues to operate in its original manner. For example, the valve  852  can continue to maintain a fluid-tight seal during a power injection through the closed catheter system  700  after one or multiple coupling/decoupling event or events. 
       FIG.  15    is a perspective view of another embodiment of an access system  1000  configured to be coupled with embodiments of a base catheter system. For example, in some embodiments, the access system  1000  is configured to be coupled with an open base catheter system, whether directly (e.g., by direct attachment to a catheter hub) and/or indirectly (e.g., by direct attachment to a proximal port of an extension set that is attached to a catheter hub), as further discussed below. The access system  1000  is shown in a fully retracted or undeployed state. 
     In the illustrated embodiment, the access system  1000  includes a connector  1002  and a cannula  1004  that is selectively advanceable and retractable relative to the connector  1002 . As with other embodiments described herein, the cannula  1004  can include a connector  1029  at a proximal end thereof. In the illustrated embodiment, the connector  1029  is a female luer. 
     The connector  1002  can include a connection interface  1010  and a reinforcement member  1030 . In the illustrated embodiment, the reinforcement member  1030  includes a distal projection  1013  that extends a significant distance past a distal face of the connection interface  1010 . The distal projection  1013  may be narrower and more elongated than a luer interface, in some instances. 
     With reference to  FIG.  16   , in some embodiments, the access system  1000  includes an internal stop, hub, or follower  1060 , to which a proximal segment  1022  of the cannula  1004  is attached. The follower  1060  can be sized to prevent the cannula  1004  from being retracted fully from a sheath  1005 . Stated otherwise, a proximal end of the sheath  1005  and the follower  1060  can cooperate to delimit proximal movement of the cannula  1004 . The follower  1060  can have a greater radial dimension than an opening  1061  at a proximal end of the sheath  1005 . In various embodiments, the follower  1060  can be fixedly secured to one or more components of the cannula  1004  (e.g., the proximal segment  1022  and/or a medial segment  1024 ) and can move in response to movement of the cannula  1004 . Stated otherwise, the follower  1060  can move in unison with the cannula  1004  and in response to forces imparted to the cannula  1004 . In particular, the follower  1060  is not directly accessible by a user, and instead moves solely in response to forces applied to the proximal segment  1022  of the cannula  1004  by a user at an exterior of the sheath  1005 . 
     In certain embodiments, the follower  1060  can restrict, inhibit, or prevent rotational movement of the cannula  1004  relative to the sheath  1005  about a longitudinal axis, which these components may have in common. Stated otherwise, the follower  1060  can cooperate with the sheath  1005  to rotationally lock the cannula  1004  relative to the sheath  1005 , thus preventing relative rotation of these components about a central longitudinal axis about which the components are concentrically arranged. For example, in the illustrated embodiment, the follower  1060  includes a protrusion  1062  that fits within a longitudinal groove  1064  defined by the sheath  1005 . In other embodiments, the groove/protrusion interface may be reversed. For example, in some embodiments, the follower  1060  defines a groove that receives a longitudinal protrusion that extends inwardly from the sheath  1005 . The protrusion  1062  and the groove  1064  may be referred to as a rotational alignment mechanism  1065  or as a rotational lock. Any suitable rotational alignment mechanism is contemplated. 
     Other embodiments may permit free rotation between the cannula  1004  and the sheath  1005 . For example, some embodiments may be devoid of a rotational alignment mechanism. For example, in some embodiments, an interior surface of the sheath  1005  and an exterior surface of the follower  1060  each may be substantially cylindrical so as to readily permit relative rotation. 
       FIG.  17 A  is a perspective view of the housing  1005 , and  FIGS.  17 B and  17 C  are separate cross-sectional views of the housing  1005 . The groove  1064 , which may also be referred to as an internal track, is visible in each view. With reference to  FIG.  17 A , in some embodiments, the housing  1005  includes one or more gripping features  1068 . The gripping features  1068  can include one or more of grooves, coverings, coatings, and/or other surface features to enhance grippability, ergonomics, and/or manipulation of the housing  1005 . The gripping features  1068  of the illustrated embodiment includes grooves and a high friction layer of material. The gripping features  1068  further include a pair of diametrically opposite raised wings  1069  at a distal end of the housing  1005 . The wings  1069  may, in some instances, assist in manipulation of the housing  1005  to rotate the housing  1005  for coupling with the access system  1000  with a connector of a catheter hub or an extension set hub. 
       FIGS.  18 A and  18 B  depict an embodiment of a coupling member  1070  that may be attached to a distal end of the housing  1005 , and may form a distal end of the connector  1002 . The coupling member  1070  can include any suitable connection interface  1010 , such as those previously discussed. In the illustrated embodiment, the connection interface  1010  includes internal threading, such as may be used, for example, to couple with a threaded luer interface. 
     The coupling member  1070  can define a reinforcing member  1030 . As with other embodiments previously discussed, the reinforcing member  1030  can include a distal projection  1013  that extends distally from a bottom, inner, or recessed surface  1017  of the connection interface  1010 . In the illustrated embodiment, the distal projection  1013  is formed of two different components. In particular, an outer layer of the distal projection  1013  is formed of a polymeric material, and constitutes an extension of a continuous casting or molding of polymeric material of which much of the reinforcing member  1030  is formed. The distal projection  1030  further includes at least a distal end of an internally situated reinforcing tube  1032 , such as reinforcing tubes previously described. The reinforcing tube  1032  is embedded within the coupling member  1070 . In some embodiments, the polymeric portion of the coupling member  1070  is overmolded onto the reinforcing tube  1032 . 
     The reinforcing member  1030  can further include an elongated proximal projection  1031  of the polymeric material. The proximal projection  1031  can extend proximally into an internal cavity of the sheath  1005  when the coupling member  1070  is secured to the sheath  1005 , as shown in  FIG.  16   . A lumen  1033  can extend continuously through the proximal projection  1031  and through the reinforcing tube  1032 . In some embodiments, an internal diameter of the lumen  1033  is substantially constant along a full length of the reinforcing member  1030 , or stated otherwise, along a full length of the lumen  1033  that extends from a proximal tip of the proximal projection  1031  to a distal tip of the reinforcing tube  1032 . 
     In other embodiments, the proximal projection  1031  may be omitted, and the reinforcing tube  1032  can be extended proximally, similar to an arrangement such as that depicted in  FIG.  7   . 
       FIGS.  19 A and  19 B  are perspective views of the follower  1060 , and  FIG.  19 C  is a cross-sectional view of the follower  1060 . The longitudinally extending protrusion  1062  is shown in each view. The follower  1060  defines a proximal cavity  1071  sized to receive a distal end of the proximal segment  1022  of the cannula  1004  therein. In some embodiments, the distal end of the proximal segment  122  is adhered to the follower  1060  (see  FIG.  23 A ). The follower  1060  can further define a distal cavity  1072  that is enlarged relative to an outer diameter of the medial segment  1024  of the cannula  1004 , such that the medial segment  1024  can readily pass through the distal cavity  1072  (see  FIG.  23 A ). The follower  1060  can include an opening  1073  through a sidewall  1074 , which sidewall  1074  separates the proximal and distal cavities  1071 ,  1072  from each other. 
     With simultaneous reference to  FIGS.  19 A,  19 B, and  23 A , the opening  1073  can be sized to permit passage therethrough of the medial segment  1024  of the cannula  1004 . A proximal end of a tube that forms at least a portion of the medial segment  1024  can extend through the opening  1073  and be embedded in a distal end of the tube that forms at least a portion of the proximal segment  1022  of the cannula  1004 , as shown in  FIG.  23 A . In some embodiments, these tubes may be adhered to one another. In certain illustrative manufacturing processes, the tubes of the cannula  1004  may be attached to one another and then passed distally through the opening  1073 , at which point the distal end of the proximal tube can be adhered to the follower  1060  within the cavity  1071 . 
       FIG.  20    is a cross-sectional view of an embodiment of the connector  1029 . In the illustrated embodiment, the connector  1029  includes a female luer interface  1074 . The connector  1029  further defines a cavity  1076  sized to receive a proximal end of the proximal segment  1022  of the cannula  1004  therein (see, e.g.,  FIG.  16   ). 
       FIG.  21    is a partially exploded elevation view of the cannula  1004  showing a tie layer  1080  separated from a distal tube  1081  and a medial tube  1082 . In the illustrated embodiment, the distal tube  1081  is included in the distal segment  1026  of the cannula  1004  and the medial tube  1082  is included in the medial segment  1024  of the cannula  1004 . The distal tube  1081  can be of any suitable material for the distal segment  1026 , such as those previously described. For example, in some embodiments, the distal tube  1081  is formed of polyimide. The medial tube  1082  likewise may be formed of any suitable material for the medial segment  1024 . For example, in some embodiments, the medial tube  1082  comprises a stainless steel tube. 
     The tie layer  1080  can be used to join the tubes  1081 ,  1082  together. For example, as discussed previously, in some embodiments, the tie layer  1080  can comprise a thin-walled tube of heat shrink material that is advanced over at least a proximal end of the distal tube  1081  and a distal end of the medial tube  1082 . The heat shrink tube can then be heated to securely attach to the ends of the tubes  1081 ,  1082  together. As with other embodiments discussed herein, in various embodiments, the distal tube  1081  comprises a polymeric material and the medial tube  1082  comprises a metallic material. The tie layer  1080  can comprise any suitable material. For example, in various embodiments, the tie layer  1080  includes a tube of heat-shrinkable polyethylene terephthalate (PET). 
       FIG.  22    is an enlarged cross-sectional view of the cannula  1004  with the tie layer  1080  in place over the tubes  1081 ,  1082 . In the illustrated embodiment, the adjoined ends of the tubes  1081 ,  1082  abut one another. In particular, in the illustrated embodiment, each tube  1081 ,  1082  end has a substantially flat or planar surface that is transverse to a longitudinal axis of the cannula  1004 . These transverse surfaces abut one another to provide a surface of continuous contact. In some instances, abutment along a plane that is perpendicular to a longitudinal axis through the tubes  1081 ,  1082  can inhibit bending at that junction of the tubes  1081 ,  1082 . For example, by maintaining tight contact at the abutting faces, the tubes  1081 ,  1082  may be less inclined to bend or kink at the junction, as compared, for example, to circumstances in which space may be provided between the adjacent tube ends. Consistent with other disclosures herein, the tubes  1081 ,  1082  may be said to abut one another at an interface  1052  of the cannula  1004 . The distal end of the medial tube  1082  represents a distal terminus  1050  of the medial member  1024 . 
     In the illustrated embodiment, the inner diameters of the tubes  1081 ,  1082  are substantially identical, such that a lumen  1021  of the cannula  1004  is substantially smooth along at a transition from the distal tube  1081  to the medial tube  1082 . In some instances, a smooth transition can inhibit or prevent hemolysis of blood due to its passage through the interface  1052 . 
     In some embodiments, a distal tip of the tie layer  1080  can be proximally spaced from the distal tip of the cannula  1004 . Such an arrangement may permit the distal tip of the tie layer to contact an internal surface of the catheter tube  104  at a distal tip of the catheter tube  104  to delimit proximal movement of the cannula  1004  relative to the catheter tube  104 . This may be an effective manner for limiting an amount of the cannula  1004  that can extend past the distal end of the catheter tube  104 . In some instances, contact between the distal end of the tie layer  1080  and a narrowed inner surface of the catheter tube  104  at the distal tip of the catheter tube  104  can provide tactile feedback to a user regarding a position of the cannula  1004  relative to the catheter tube  104 , and in particular, to alert the user that the cannula  1004  has been fully deployed. 
       FIG.  23 A  is a cross-sectional view of a generally proximal portion of the access system  1000  when the access system  1000  is in a retracted state, or stated others, when the cannula  1004  of the access system  1000  is in a retracted state. As shown, the follower  1060  may be substantially at a proximal end of the sheath  1005  when the cannula  1004  is in the retracted state. 
       FIG.  23 B  is a cross-sectional view of a distal portion of the access system  1000  in the retracted state. In this state, similar to previously described embodiments, the interface  1052  of the cannula  1004  can be positioned within the reinforcement member  1030 . Stated otherwise, an entirety of a proximal end of the distal segment  1026  of the cannula  1004 , including a proximal tip of the distal segment  1026 , and the distal terminus  1050  of the medial segment  1024  each can be positioned within the reinforcement member  1030  when the cannula  1004  is in the retracted state. In the illustrated embodiment, the interface  1052  is positioned within the proximal extension  1031  of the reinforcement member  1030  in this operational state. 
     In the illustrated embodiment, the distal tube  1081  has a distal tip that is slightly recessed relative to a distal tip of the reinforcement tube  1032  of the reinforcement member  1030 . In the illustrated embodiment, an entirety of the distal tube  1081  is positioned within the reinforcement member  1030 . A distal end of the distal tube  1081  is within the reinforcement tube  1032  of the reinforcement member  1030 , while a proximal end of the distal tube  1081  is within the proximal extension  1031  of the reinforcement member  1030 . As with other embodiments discussed herein, the reinforcement member  1030  can prevent the distal tube  1081  from bending or kinking during an insertion event, due to the reinforcement provided by the relatively close fit between the inner diameter of the reinforcement member  1030  and the outer diameter of the distal tube  1081 . 
       FIG.  24    is an exploded perspective view of an embodiment of a base catheter assembly  1100  that includes an embodiment of an open intravenous catheter assembly  1101  and an embodiment of an extension set  1150  that is couplable to the open intravenous catheter assembly  1101 . The catheter assembly  1101  includes a catheter hub  1106  and a catheter tube  1104 , which can resemble the catheter hub  106  and the catheter tube  104  described previously. 
     The extension set  1150  includes an extension hub  1180  that includes a distal port  1181 , a side port  1182 , and a proximal port  1183 . The distal port  1181  can include a connector  1151  of any suitable variety configured to couple with the catheter hub  1106 . In the illustrated embodiment, the connector  1151  comprises a rotatable luer lock connector for selective engagement of a male luer  1171  with the catheter hub  1106 . The side port  1182  includes an extension tube  1157  coupled thereto. A connector  1158  is attached to an opposite end of the extension tube  1157 . The proximal port  1183  can include a connector  1162 , to which a connection interface of any suitable access system (e.g.,  200 ,  300 ,  400 ,  500 ,  600 ,  1000 ) can be attached. In some embodiments, a valve  1184 , which may also or alternatively be referred to as a septum, seal, etc., may be included within the proximal port  1183 . In some instances, the projection  1013  of the access system  1000  can be capable of extending through the valve  1184 , and the cannula  1004  can be deployed, advanced, or extended distally from the distal end of the projection  1013  at a position distal of the valve  1184 . 
     Each of the distal port  1181 , the side port  1182 , and the proximal port  1183  can be in fluid communication with an inner chamber  1173  (see  FIG.  25   ) defined by the extension hub  1180 . As noted, in some embodiments, the proximal port  1183  may permit selective fluid communication with the inner chamber  1173  via the valve  1184 . 
       FIG.  25    is a cross-sectional view of the base catheter assembly  1100  in an assembled state. The cross-sectional view is taken such that the side port  1182  is not shown. The male luer  1171  can be inserted into and fluidically sealed with the female luer of the catheter hub  1106 . The male luer  1171  can have an elongated lumen  1172  at an interior thereof, which corresponds with a distal end of the inner chamber  1173 . The lumen  1172  can be a necked down or narrowed section of the inner chamber  1173 . In general, when the access system  1000  is coupled with the extension set  1150 , rather than directly with the catheter hub  1106  of the catheter assembly  1101 , the cannula  1004  travels through a greater distance before entering the catheter tube  1104 . Stated otherwise, the catheter hub  1106  provides a first unsupported length between a distal tip of the access system  1000  and a proximal end of the catheter tube  1104  when the access system  1000  is coupled directly to the catheter hub  1106 , whereas the catheter hub  1106  and the extension hub  1180 , when coupled together, provide a second unsupported length between the distal tip of the access system  1000  and the proximal end of the catheter tube  1104 , when the access system  1000  is directly coupled, to the extension hub  1180 , and the second unsupported length is significantly greater than the first unsupported length. 
       FIG.  26    is a side elevation view of the access system  1000  in the retracted state coupled with the assembled base catheter assembly  1100 , which includes the extension set  1150  that has the side port  1182 .  FIG.  27    is a cross-sectional view of a distal portion of the access system  1000  in the retracted state while coupled with the assembled base catheter assembly  1100 . As with  FIG.  25   , the cross-sectional view is taken such that the side port  1182  of the extension set  1150  is not shown. 
     With the connector  1002  of the access system  1000  coupled with the connector  1162  of the extension set  1150 , the distal projection  1013  of the reinforcement member  1030  extends into the inner chamber  1173  of the extension hub  1180 . In the illustrated embodiment, the distal tip of the distal projection  1013  is positioned within a proximal end of the narrowed lumen  1172  of the male luer  1171 . The distal tip of the projection  1013  is proximally spaced from a proximal tip  1107  or proximal edge of the catheter hub  1106 . Accordingly, as previously discussed, the cannula  1004  has a greater distance to travel through the extension hub  1180  and the catheter hub  1106  in order to enter the proximal end of the catheter tube  1104  than is needed when an access system  1000  is coupled directly to a catheter hub  1106 . In some embodiments, the distal projection  1013  may be longer and/or narrower for access assemblies that are intended for use with extension sets than are those intended for use directly with catheter hubs  1106 . Moreover, in the illustrated embodiment, a distal end of the distal projection  1013  is advanced into the narrowed lumen  1172  of the male luer  1171 . Correspondingly, in some embodiments, the distal projection  1013  may be longer than and/or narrower than a standard male luer. 
       FIG.  28    is a cross-sectional view of the access system  1000  in a fully deployed state while coupled with the assembled base catheter assembly  1100 .  FIGS.  29 A- 29 C  are close-up cross-sectional views of various portions of the access system  1000  and the base catheter assembly  1100  in this operational configuration. In particular,  FIG.  29 A  depicts a generally intermediate portion of the access system  1000 ,  FIG.  29 B  depicts a generally distal portion of the access system  1000  and a proximal portion of the base catheter assembly  1100 , and  FIG.  29 C  depicts the distal ends of the access system  1000  and the base catheter assembly  1100 . 
     As shown in  FIG.  29 A , in some embodiments, the proximal extension  1031  of the reinforcement member  1030  can delimit distal movement of the cannula  1004 . As previously discussed, the proximal segment  1022  of the cannula  1004  may be fixedly secured to the follower  1060 . The distal cavity  1072  of the follower  1060  can have a sufficiently large inner diameter to receive a proximal end of the proximal extension  1031  of the reinforcement member  1030  therein. As the cannula  1004  is advanced distally, the distal cavity  1072  of the follower  1060  advances over the proximal end of the proximal extension  1031  until contact is made between the sidewall  1074  of the follower  1060  and the proximal extension  1031 . This contact can prevent further distal advancement of the cannula  1004 . 
     With reference to  FIG.  29 B , in the illustrated embodiment, when the cannula  1004  is in the fully deployed position, the distal segment  1026  extends into and through the catheter tube  1104 . In particular, as shown in  FIG.  29 C , in the illustrated embodiment, the distal segment  1026  of the cannula  1004  extends a significant distance beyond a distal tip  1109  of the catheter tube  1104 . In various embodiments, the distal segment  1026  may extend distally beyond the distal tip of the catheter tube  1104  by a distance that is no less than 3, 5, 10, or 15 times greater than an outer diameter of the distal segment  1026 . 
     With reference again to  FIG.  29 B , when the cannula  1004  is in the fully deployed position, the interface  1052  at which the distal and medial segments  1026 ,  1024  meet may be positioned proximally relative to the proximal tip  1107  of the catheter tube  1104 . Stated otherwise, the distal terminus  1050  of the medial segment  1024  may remain external to the catheter tube  1104 , while being positioned distal of the reinforcing member  1030 . In some instances, the intrinsic support or self-reinforcing properties of the medial segment  1024  can inhibit kinking or buckling of the cannula within the elongated, generally unsupported region of the inner chamber  1173  of the extension hub  1180  and the internal chamber of the catheter hub  1106  as the cannula  1004  is advanced distally. 
     In other embodiments, the medial segment  1024  may enter, and further, may pass through at least a proximal portion of the catheter tube  1104 . For example, as previously described, in some embodiments, the distal and medial segments  1026 ,  1024  may have substantially the same outer diameter dimensions, such that the medial segment  1024  could readily follow the distal segment  1026  into the catheter tube  1104 . 
     Relative lengths of, e.g., the reinforcement member  1030  (e.g., the proximal projection  1031  thereof) and the cannula  1004 —particularly the overall length of the reinforcement member  1030  and a length of the portion of the cannula  1004  that is inserted through extension set  1150  and into and through the catheter tube  1104 —can be adjusted to ensure that a distal tip of the cannula  1004  reaches a desired position relative to the distal tip of the catheter tube  1104  when the cannula  1004  is in the fully deployed state. For example, as previously discussed, in various embodiments, a distal tip of the cannula  1004  may desirably extend distally beyond, may be substantially flush with, or may be slightly proximally recessed relative to the distal tip of the catheter tube  1104  when the cannula  1004  is in the fully deployed state. 
     Relative lengths of, e.g., the reinforcement member  1030  (e.g. the proximal extension  1031  thereof) and the medial segment  1024  can be adjusted to ensure that a distal tip of the medial segment  1024  reaches a desired position relative to the proximal end of the catheter tube  1104  when the cannula  1004  is in the fully deployed state. For example, as previously discussed, in various embodiments, a distal tip or distal terminus  1050  of the medial segment  1024  may remain proximally recessed, may be substantially flush with, or may enter into the proximal end of the catheter tube  1104  when the cannula  1004  is in the fully deployed state. 
     In other embodiments, the medial segment  1024  may include an outer tube, or support tube (e.g., such as the support tube  1495  depicted in  FIGS.  56 A and  56 B  and described below). In some embodiments, at least an outer diameter of the support tube may be larger than an opening at the proximal end of the catheter tube  1104  (e.g., which correspond to an inner diameter of the catheter tube  1104 ). The distal tip of the support tube, which corresponds to the distal terminus  1050  of the medial segment  1024 , can prevent the medial segment  1024  from entering into the catheter tube  1104 . In some embodiments, use of a larger diameter support tube as just described can advantageously act as a primary defense against entry of the support tube into the catheter tube  1104 . In other embodiments, this can act as a failsafe to ensure that the distal tip of the support tube does not enter the catheter tube  1104 , such as, for example, where other dimensions of the access assembly  1000  also have been selected to prevent the support tube from entering the catheter tube  1104 . For example, in some embodiments, it may be desirable to avoid entry of the distal tip of the support tube, which otherwise could, in some arrangements, potentially deform, scrape, mar, and/or damage the catheter tube  1104  if permitted to enter therein. In other embodiments, the support tube may be sufficiently narrow to enter the catheter tube  1104 . 
     With continued reference to  FIG.  29 B , as previously discussed, there may be a significant distance between the distal tip of the reinforcement member  1030  and the proximal end of the catheter tube  1104  when the extension set  1150  is present. In some instances, the self-reinforced medial segment  1024  can be sufficiently strong and/or rigid to avoid bending, kinking, or buckling within the unfilled portion of the cavity  1173  of the extension hub  1180  and the adjoining unfilled cavity of the catheter hub  1106  as the cannula  1004  is distally advanced through this enlarged cavity region (i.e., enlarged as compared with the constriction provided by the reinforcement member  1030 ). In other or further instances, the self-reinforced medial segment  1024  can maintain alignment of the distal segment  1026  with a longitudinal axis of the catheter tube  1104  as the cannula  1004  is advanced distally. In other or further instances, the self-reinforced medial segment  1024  can reduce an unsupported length of the cannula  1004  within the extension hub  1180  and further, in some instances and/or in later stages of deployment, within the catheter hub  1106  as the cannula  1004  is advanced distally to the fully deployed state. 
     In some instances, the cannula  1004  may not be moved to a fully deployed state. For example, in some instances, the cannula  1104  may only be advanced from the initial or retracted position to a partially advanced position. This partially deployed, partially advanced, or intermediate state may be sufficient to achieve a desired position of the distal tip of the cannula  1004  beyond or within the distal end of the catheter tube  1104 . For example, in some embodiment, the access system  1000  may be usable with a variety of different base catheter systems that may have varying lengths of catheter tubes  1104 , and the user may deploy the cannula  1004  by a different amount depending on which length of catheter tube is present. 
       FIG.  30    is a perspective view of another embodiment of an access system  1200  configured to be coupled with embodiments of a base catheter system, with the access system  1200  being shown in a retracted or undeployed state. The access system  1200  may be particularly well-suited for use with a closed intravenous catheter system, such as, for example, a NEXIVA™ closed catheter system. Embodiments of the access system  1200  may resemble, e.g., embodiments of the access systems  300 ,  400 ,  500 ,  600  described above. Relevant disclosures regarding the various access systems  300 ,  400 ,  500 ,  600 ,  1200  thus may be applied interchangeably. 
     For example, the access system  1200  can include a cannula  1204  of any suitable variety, including those disclosed elsewhere herein. In some embodiments, the cannula  1204  can be of any of the varieties discussed above, such as, for example, with respect to the cannulas  204 ,  1004 , or below, such as, for example, with respect to the cannula  1404 . 
     In the illustrated embodiment, the access system  1200  includes a connector  1202  that is configured to couple with the proximal port  809  of embodiments of a closed intravenous catheter system  700  (see, e.g.,  FIGS.  14  and  34   ). For example, the distal end of the connector  1202 , can include a snapping or snap-fit arrangement. In the illustrated embodiment, the connector end  1202  includes a pair of opposing arms or flaps  1280  with inward protrusions  1281  to securely snap onto the proximal port  809 , as shown in  FIG.  32 A  (see also  FIGS.  33  and  34   ). 
       FIG.  31    is a cross-sectional view of the access system  1200  in the retracted state.  FIG.  32 A  is a perspective view of an embodiment of a coupling member  1270  that is compatible with the access system  1200 .  FIG.  32 B  is a cross-sectional view of the coupling member  1270 . The coupling member  1270  includes a reinforcing tube  1232  that extends or projects distally relative to a bottom, inner, recessed, or distally facing surface  1217  of the connector  1202 , in manners such as previously discussed. 
     In other embodiments, the proximal projection  1231  may instead be defined solely by a proximal extension of the reinforcing tube  1232 , similar to an arrangement such as that depicted in  FIG.  7   . Stated otherwise, the reinforcing tube  1232  may define both a distal projection  1213  and the proximal extension  1231 . 
       FIG.  33    is a cross-sectional view of a distal end of the access system  1200 , while in the retracted or undeployed state, being advanced toward an embodiment of a closed intravenous catheter system  700  for coupling therewith.  FIG.  34    is a cross-sectional view of the distal end of the access system  1200 , while in the retracted or undeployed state, coupled with the closed intravenous catheter system  700 . In the illustrated embodiment, a distal tip of the reinforcing tube  1232  is advanced through the proximal septum  851 , but is proximally spaced from the valve  852  when the access system  1200  and the closed catheter system  700  are coupled together. Advancement of a cannula portion of the access system  1200  through the reinforcing tube  1232 , the valve  852 , and ultimately the catheter tube  704  can proceed in manners such as previously discussed. 
     For example, in the illustrated embodiment, the reinforcing tube  1232  is advanced distally through the opening  855  of the retainer  853 , then through the opening  854  of the proximal septum  851 . These openings  855 ,  854  are aligned, or are colinear with, the sealable region  856  (and more particularly, the substantially linear needle tract through the sealable region  856 ). In the illustrated embodiment, once the access system  1200  is fully coupled to the proximal port  809  of the closed intravenous catheter system  700 , the distal tip of the reinforcing tube  1232  is positioned at an interior of the proximal septum  851 , as shown in  FIG.  34   . After such coupling, the cannula  1204  can be advanced distally, and the distal tip of the cannula  1204  can emerge from the reinforcing tube  1232  to move substantially rectilinearly through the distal end of the proximal septum  851 , then through the valve  852  (including through the sealable region  856  of the valve  856 ), then through the hub  806 , then into and through the catheter tube  704 . As discussed elsewhere, the support member  1230  and/or the intrinsic support provided by the medial segment of the cannula  1204  can assist in the successful insertion of the cannula  1204  through the valve  852  without kinking or buckling of the distal segment of the cannula  1204 . 
     In some instances, once the distal tip of the cannula  1204  has passed through the sealable region  856  of the valve  852 , the valve  852  may support the cannula  1204  as it is further advanced distally through the hub  806  and the catheter tube  704 . For example, the valve  852  can provide lateral support that inhibits lateral deflections of the cannula  1204  in the region of contact between the sealable region  856  and the cannula  1204 . 
     With continued reference to  FIG.  34   , as previously noted, in various embodiments, the cannula  1204  may resemble any of the disclosed varieties of the cannulas  204 ,  1004 , or  1404  (which is described below). For example, in some embodiments, the cannula  1204  includes a distal segment and a medial segment that resemble any variety of the distal and medial segments  226 ,  224  and/or  1026 ,  1024 , respectively, discussed above, and/or the distal and medial segments  1426 ,  1424 , respectively, discussed below. While only the distal segment is shown in  FIG.  34   , the presence and structure of medial segment can be understood from other drawings and disclosures herein. 
     In some embodiments, the medial segment of the cannula  1204  includes two abutting tubes that are joined by heat-shrink tubing (see, e.g.,  FIG.  22   ). The medial tube can be rigid, and may be formed of a metal—for example, the medial tube may comprise a stainless steel hypotube. In other embodiments, the medial segment of the cannula  1204  includes a flexible central tube that extends continuously along the distal and medial segments, but that is encompassed by a rigid tube along the length of the medial segment (see, e.g.,  FIGS.  56 A and  56 B ). The rigid tube may be formed of metal, such as a stainless steel hypotube. In either instance, the medial segment can have substantial radial strength so as to resist radial compression that might otherwise constrict or close a lumen through the tube. For example, in various embodiments, due to the presence of a rigid tube in the medial segment, the medial segment can have a greater ability to maintain a fluid path that extends through a center of the medial segment in an open state, even under radial forces or stresses on the medial segment that would tend to constrict or close the fluid path if left unopposed. 
     In certain embodiments of the access system  1200 , when the cannula  1204  is in the deployed state, the medial segment of the cannula  1204  fully extends through the valve  852  of the closed intravenous catheter system  700 . For example, in some embodiments, either the rigid tube that forms the medial segment or the support cannula that encompasses a flexible inner tube along the length of the medial segment passes through the valve  852  near the end of advancement of the cannula  1204  through the catheter tube  704 . Due to the intrinsic rigidity of the rigid tube of the medial segment, the medial segment can prevent inward stresses provided to the cannula  1204  by the valve  852  that result from expansion of the sealable opening  856  from collapsing the medial segment. For example, in certain embodiments that include a flexible central tube positioned within a rigid tube, the rigid tube can resist the compressive forces from the valve  852  to maintain the inner tube in a patent state. Stated otherwise, upon final advancement of the cannula  1204 , or when a user is ready to aspirate or draw blood through the cannula  1204 , the medial segment of the cannula  1204  can extend throughout an entirety of the sealable region  856  of the valve  852  to prevent the valve  852  from collapsing a flow path through the cannula  1204 . 
     In various embodiments, an outer diameter of the medial segment of the cannula  1204  is the same as or only slightly larger than an outer diameter of the distal segment. For example, in various embodiments, the outer diameter of the medial segment is no greater than 5, 10, or 15 percent larger than the outer diameter of the distal segment. In some embodiments, a medial segment having a diameter that is the same or only slightly larger than the outer diameter of the distal segment may readily follow the distal segment through the valve  852  as the cannula  1204  is advanced distally and/or may pass through the valve  852  without causing damage thereto. In other or further embodiments, by virtue of following the distal segment into and through the valve  852 , the medial segment may readily pass through the valve  852  and/or may do so without damaging the valve  852 . 
     Reference is now made to  FIGS.  35 - 53   , which are directed to another embodiment of an access system  1300  that may be particularly useful with open base catheter systems. For example, in some instances, the access system  1300  may be particularly well suited for use with open base catheter systems that include an extension set coupled with a catheter assembly, such as the open base catheter system  1100  depicted in  FIGS.  24  and  25   . As previously discussed with respect to  FIGS.  24 - 27  and  29 B , the catheter system  1100  can include a large internal region in which a cannula, when positioned therein, is unsupported as the cannula is advanced distally therethrough. This region of relatively large internal diameter(s) corresponds with the inner cavities of the connected hubs  1180 ,  1106  (see  FIG.  25   ). With reference to  FIG.  36   , embodiments of the access system  1300  can include a reinforcement member  1330  that includes a movable reinforcement cannula  1332 . The reinforcement cannula  1332  is movable relative to a connector  1302  so as to advanced distally into this unsupported region of the catheter system  1100  and provide lateral support or reinforcement to a cannula  1304  as it is advanced distally through the hubs  1180 ,  1160  into the catheter tube  1104  of the catheter system  1100 . 
     The cannula  1304  can be of any suitable construction, including those discussed elsewhere herein. For example, in some embodiments, the cannula  1304  includes at least a distal segment and a medial segment formed in manners such as described elsewhere. The medical segment may be intrinsically reinforced so as to resist or prevent kinking or buckling thereat as the cannula  1304  is advanced distally. 
       FIG.  35    is a perspective view of the access system  1300  in a retracted or undeployed state. As noted, in some embodiments, the access system  1300  can be particularly well-suited for use with open intravenous catheter systems, and may further be well-suited for use with extension sets coupled with such open intravenous catheter systems. The movable reinforcement tube  1332  can be said to support the cannula  1304  along at least a portion of a length of the extension set, such as the extension set  1150 , and/or through a length of a catheter hub to which the extension set is coupled, such as the catheter hub  1106 .  FIG.  36    is a cross-sectional view of the access system  1300  in the retracted state. 
       FIG.  37 A  is a perspective view of an embodiment of the connector  1302 , which includes a housing  1305  that is compatible with the access system  1300 .  FIG.  37 B  is a perspective cross-sectional view of the housing of  FIG.  37 A . The housing  1305  can define a proximal chamber  1390  and a distal chamber  1391 . The distal chamber  1391  can have a larger inner diameter than does the proximal chamber  1390 . As discussed below, the proximal chamber  1390  can be narrower so as to define a restricted region, whereas the distal chamber  1391  can be relatively larger to define an expanded region. In the illustrated embodiment, the proximal chamber  1390  includes a track  1364 , similar to the anti-rotational track  1064  discussed previously. 
     The housing  1305  can include a distal protrusion  1313  similar to like numbered elements above. As discussed further below, the distal protrusion or projection  1313  can cooperate with or support a reinforcing member  1330  (see  FIG.  36   ). The distal projection  1313  can be fixed relative to the connector  1302 . For example, the distal projection  1313  may be integrally formed with at least a distal end tube of the housing  1305 . The distal projection  1313  may define an inner diameter that is slightly larger than an outer diameter of the reinforcing tube  1332 . The reinforcing tube  1332  may be sized to slide through the distal projection  1313 . The distal projection  1313  may be viewed as a component of the reinforcing member  1330 . For example, the reinforcing member  1330  can include both the distal projection  1313  and the reinforcing cannula  1332 . In various embodiments, at least a portion of the reinforcing member  1330  is fixed relative to the housing  1305 . In various embodiments, at least a portion of the reinforcing member  1330  is movable relative to the connector housing  1305 . 
       FIG.  38 A  is a perspective view of an embodiment of a follower  1360  that is compatible with the access system  1300 . The follower  1360  can include a selective engagement feature that can engage with or disengage from the reinforcing cannula  1332 .  FIG.  38 B  is a cross-sectional view of the follower  1360 . The follower  1360  includes a selective engagement feature, by which the follower  1360  can selectively engage and selectively disengage from the reinforcing cannula  1332 . In particular, the follower  1360  includes a plurality of engagement arms  1392  having distal ends configured to interface with a catch  1393  attached to the reinforcing cannula  1332  (see  FIG.  42   ). In particular, the engagement arms  1392  can each include an engagement protrusion  1394  that is configured to interface with the catch  1393  in manners such as described below. In the illustrated embodiment, each engagement protrusion  1394  includes an engagement face  1395 . The engagement face  1395  may be a ramped or angled surface. Each engagement face  1395  may be angled away from a central longitudinal axis of the follower  1360 , in a proximal-to-distal direction. 
     The follower  1360  can include an anti-rotation protrusion  1362 , which can resemble the protrusion  1062  discussed above. The anti-rotation protrusion  1362  may be configured to interface with the track  1364  of the housing  1305  in manners such as previously described. The follower  1360  may further include a proximal cavity  1371  and an opening  1373 , which may be similar to the proximal cavity  1071  and the opening  1073  described above. 
       FIG.  39 A  is a perspective view of an embodiment of a reinforcement shuttle  1335  that includes the reinforcing tube  1332  and the catch  1393 .  FIG.  39 B  is a cross-sectional view of the reinforcement shuttle  1335 . 
     The catch  1393  can be fixedly secured to a proximal end of the reinforcement tube  1332 . The catch  1393  can define a recess  1337  that is sized to receive the engagement protrusions  1394  of the engagement arms  1392 . In the illustrated embodiment, the recess  1337  is formed as an annular depression have a cross-sectional profile that is complementary to a profile of each engagement protrusion  1394 . The recess  1337  can include an engagement face  1339  that is configured to make contact with the engagement faces  1395  of the engagement protrusions  1394 . The engagement face  1339  may be a ramped or angled surface. In particular, the engagement face  1339  can be angled away from a central longitudinal axis of the reinforcement shuttle  1335 , in a proximal-to-distal direction. The ramped engagement faces  1339 ,  1395  of the catch  1393  and the arms  1392  may be referred to as a ramped interface. 
       FIG.  40    is a cross-sectional view of a distal end of the access system  1300  when in the retracted state. In the illustrated embodiment, when in this operational state, a distal tip of the cannula  1304  is recessed relative to a distal tip of the reinforcement cannula  1332 , which is recessed relative to a distal tip of the distal projection  1313 . 
       FIG.  41    is a cross-sectional view of a larger distal region of the access system  1300  when in the retracted state. As shown, both the distal projection  1313  and the reinforcement shuttle  1335 , which includes the reinforcement cannula  1332 , can be components of the reinforcement member  1300 . These components cooperate to reinforce the cannula  1304  as it is advanced from the retracted position, in manners such as discussed hereafter. 
       FIG.  42    is a cross-sectional view of an intermediate region of the access system  1300  when in the retracted state. As can be seen in this view, the cannula  1304  can include a distal segment  1326  and a medial segment  1324 , which can resemble like-named and numbered features discussed elsewhere herein. For example, in some embodiments, the distal segment  1326  can be formed of a polymeric tube (e.g., of polyimide). In some embodiments, the medial segment  1324  includes a proximal extension of the polymeric tube, and further includes a rigid tubular support member (e.g., of metallic construction) that encompasses the polymeric tube. In other embodiments, the medial segment  1324  comprises a rigid tube (e.g., formed of metal) that includes a distal tip that abuts a distal tip of the polymeric tube; the abutting ends of the tubes may be joined in any suitable fashion, such as via an overlying heat shrink tube. Other suitable arrangements are contemplated. The distal and medial segments  1326 ,  1324  can meet at an interface  1352 , which is positioned within the reinforcement tube  1332  in the illustrated retracted state of the access system  1300 . 
     In the illustrated retracted state (also depicted in  FIG.  45   ), the catch  1393  and the distal ends of the arms  1392  of the follower  1360 , which are coupled to the catch  1393 , can be positioned within the proximal chamber  1390  of the housing  1305 . The narrow inner sidewall of the housing  1305  that defines the proximal chamber  1390  can constrain the arms  1392  so as to maintain the arms  1392  in a coupled state with the catch  1393 . In particular, the proximal chamber  1390  can be sized to maintain the angled faces  1395 ,  1339  of the arms  1392  and the catch  1335 , respectively, engaged with each other. As further discussed below, this engagement of the angled faces may permit the arms  1392  of the follower  1360  to urge the catch  1393  distally as the cannula  1304 , to which the follower  1360  is attached, is advanced distally. 
     In some embodiments, the arms  1392  may be resiliently biased outwardly, or away from the central longitudinal axis, so as to spring outwardly when no longer constrained within the proximal chamber  1390 . In other embodiments, the arms  1392  may be devoid of a bias. The arms  1392  may be sufficiently flexible to be capable of being urged outwardly by the interaction of the angled faces  1395 ,  1339  when distal advancement of the reinforcement shuttle  1335  is inhibited and when the arms  1392  are not constrained within the proximal chamber  1390 , as further discussed below. 
       FIG.  43    is a cross-sectional view of a generally proximal portion of the access system  1300  when in the retracted state. The follower  1360  can be positioned at a proximal end of the housing  1305 . The anti-rotation protrusion  1362  can be positioned within the track  1364  of the housing  1305 . Further details of the cannula  1304 , which can resemble other cannulas previously discussed, are also shown. 
       FIG.  44    is a cross-sectional view of the access system  1300  coupled with an embodiment of a base catheter assembly  1100  while the access system  1300  is in the retracted state. The base catheter assembly  1100  includes the open intravenous catheter  1101  and the extension set  1150  that is coupled thereto, in manners such as previously described with respect to  FIGS.  24  and  25   . 
       FIG.  45    is a cross-sectional view of a generally intermediate region of the access system  1300  while in the coupled and retracted configuration depicted in  FIG.  44   .  FIG.  46    is a cross-sectional view of a distal portion of the access system  1300  while in the coupled and retracted state, which further depicts a proximal portion of the catheter assembly  1100 . As shown in  FIG.  46   , the distal projection  1313  can extend a significant distance within the hub  1180 . However, as previously discussed, a larger diameter region extends between the distal tip of the distal projection  1313  and the proximal tip of the catheter tube  1104  within the hubs  1180 ,  1106 . This is the region that is bridged by the reinforcement tube  1332  as the access system  1300  is deployed, as further discussed below. 
       FIG.  47    is a cross-sectional view of the access system  1300  coupled with the base catheter assembly  1100  while in a partially deployed state, or stated otherwise, while in an intermediate stage or state of deployment. The cannula  1304  has been advanced distally through a first distance, which in turn, has advanced the follower  1360  distally through the housing  1305  by the same distance. 
       FIG.  48    is a cross-sectional view of an intermediate region of the access system  1300  while in the partially deployed state. In being advanced to the illustrated orientation, the arms  1392  have been and remain in a low-profile state, as constrained by the proximal chamber  1390 . This maintains contact between the ramped surfaces  1395 ,  1339 . The ramped surfaces  1395  pushes against the ramped surface  1339  to advance the reinforcement shuttle  1335  distally in unison with distal advancement of the follower  1360  and the cannula  1304 . 
     As shown, the distal ends of the arms  1392  have advanced distally past the end of the proximal chamber  1390  of the housing  1305  and have entered the enlarged cavity of the distal chamber  1391 . In the illustrated embodiment, the arms  1392  are not resiliently outwardly biased, and thus do not automatically expand to an enlarged state when no longer constrained in a low-profile orientation. A substantial proximal length of the arms  1392  remains positioned within the proximal chamber  1390  in the constrained state, such that the distal tips of the arms  1392  will generally remain in the low-profile state, even when in the enlarged distal chamber  1391 , unless and until they are urged outwardly. Stated otherwise, the distal ends of the arms  1392  are at a position within the distal chamber  1391  at which they may be allowed to be urged radially our laterally outwardly to an expanded profile. 
       FIG.  49    is a cross-sectional view of a distal end of the access system  1300  and a proximal portion of the base catheter assembly  1100  while the access system  1300  is in the partially deployed state. At this point, a distal tip of the reinforcement tube  1332  has come into contact with the proximal tip  1107  of the catheter tube  1104 . This contact can prevent further distal advancement of the reinforcement tube  1332 . In the illustrated configuration, the distal end of the cannula  1304  remains within the reinforcement tube  1332  until there is relative movement between the follower  1360  and the reinforcement shuttle  1335  ( FIG.  48   ). 
       FIG.  50    is a cross-sectional view of the access system  1300  coupled with the base catheter assembly  1100  while in fully deployed state.  FIG.  51    is a cross-sectional view of an intermediate region of the access system  1300  while in the fully deployed state. In reaching this state, the reinforcement shuttle  1335  remains in the same configuration depicted in  FIGS.  47 - 49   . That is, the distal tip of the reinforcement tube  1330  remains abutted against the proximal tip  1107  of the catheter tube  1104  ( FIG.  49   ). Note that in other embodiments, the reinforcement tube  1330  may additionally or alternatively be sized to abut against an inner surface of the catheter hub  1106  ( FIG.  49   ). As the cannula  1304  is advanced distally relative to the orientation shown in  FIGS.  47 - 49   , the follower  1360  moves distally in unison with the cannula  1304 , to which it is attached. The reinforcement tube  1104  and the catch  1393  that is attached thereto remain in a fixed position relative to the housing  1305  due to interference between the reinforcement cannula  1332  and the catheter tube  1104 . The ramped or angled surfaces  1395  of the arms  1392  press against the ramped or angled surface  1339  of the immobilized catch  1393 . The angled surfaces  1395  interact with the angled surface  1339  to urge the distal ends of the arms  1392  outwardly. The distal chamber  1391  of the housing  1305  provides sufficient clearance to permit the deflected ends of the arms  1392  to pass over the catch  1393  and resiliently return to the straightened state shown in  FIG.  51   . As the cannula  1304  is further advanced distally, the follower  1360  moves in unison with the cannula  1304  and the arms  1392  of the follower  1360  pass over or by or beside the outer surface of the catch  1393 . 
     In various embodiments, various parameters may be adjusted to permit the arms  1392  to disengage from and move distally relative to the catch  1393  in manners such as just described. For example, in some embodiments, a stiffness of the arms  1392  may be selected to ensure that disengagement only occurs once threshold level of resistance to distal movement of the reinforcement tube  1332  is experienced. A relative orientation of the proximal and distal chambers  1390 ,  1391  of the housing  1305  may also or alternatively be adjusted. In various embodiments, the access system  1300  may be configured for use with a variety of different base catheter systems (with and/or without extension sets) that define a variety of different lengths through which the reinforcement tube  1332  passes before encountering resistance to forward advancement. Certain embodiments may permit the arms  1392  to remain engaged with the catch  1393  until resistance is met at any of these various lengths and to thereafter disengage from the catch  1393 . 
       FIG.  52    is a cross-sectional view of a generally distal portion of the access system  1300  and a proximal portion of the base catheter assembly  1100  while the access system is in the fully deployed state. As shown, the distal tip of the reinforcement cannula  1332  remains engaged with and immobilized by the proximal tip  1107  of the catheter tube  1104  throughout distal advancement of the cannula  1304  past the intermediate position depicted in  FIGS.  47 - 49   . The cannula  1304  passes through the immobilized reinforcement cannula  1332  and is reinforced thereby in the event that resistance to distal movement of the cannula  1304  is encountered, such as at a bend or kink in the catheter tube  1304 . 
       FIG.  53    is a cross-sectional view of distal ends of the access system  1300  and the base catheter assembly  1100  while the access system  1300  is in the fully deployed state. In the illustrated embodiment, the cannula  1304  extends past the distal tip of the catheter tube  1104 . 
       FIG.  54    is a perspective view of another embodiment of an access system  1400 , and  FIG.  55    is a cross-sectional view of the access system  1400 . The access system  1400  is shown in both drawings in a retracted state. The access system  1400  includes a removable sterility cap  1494  that is coupled to a connector  1402 . The cap  1494  can be included with the packaged access system  1400  and removed prior to use. The illustrated connector  1402  includes a snap-fit arrangement, such as previously disclosed, for example, with respect to the access system  1200 . 
     The access system  1400  may resemble the access system  1200  in many respects, and may be particularly suitable for use with a closed intravenous catheter system. As discussed above, the cannula  1204  of the embodiment of the access system  1200  illustrated in  FIGS.  30 - 34    includes two abutting tubes that are joined by heat-shrink tubing. However, other cannula configurations are disclosed with respect to the access system  1200 , including a cannula that includes a continuous polymeric tube and a support tube that encompasses at least an intermediate region of the polymeric tube. The cannula  1204  of the access system  1400  is of the latter configuration. 
     With reference to  FIGS.  56 A and  56 B , the cannula  1404  can include a proximal segment  1422 , a medial segment  1424 , and a distal segment  1426 . The cannula  1404  includes a central tube  1496  that defines the distal segment  1426 . The central tube  1496  extends continuously through the medial segment  1424 . A proximal end of the central tube  1496  is positioned in a portion of the proximal segment  1422 . The proximal segment  1422  further includes a proximal tube  1422  of any suitable form, such as described previously herein. The central tube  1496  may be coupled with the proximal tube  1422  in any suitable manner, such as by a press fit, adhesive, etc. At least the proximal tube  1422  may be fixedly secured to a follower  1460 . 
     The central tube  1496  may be formed of any suitable material, such as disclosed with respect to other embodiments (e.g., a polymeric material). The central tube  1496  may be flexible. Embodiments of the central tube  1496  can be laterally flexible while having sufficient columnar or axial strength or rigidity to navigate or negotiate tortuous paths through a catheter tube and/or sufficient radial strength to remain patent when within such tortuous paths. The medial segment  1424  can further include a support tube  1495  that encompasses, encircles, sheathes, covers, overlays, etc. an intermediate portion of the central tube  1496 . The support tube  1495  may be relatively rigid, as previously discussed. In some embodiments, the support tube  1495  may be metallic, such as a stainless steel hypotube. In some embodiments, the support tube  1495  is fixedly secured to at least a proximal end of the central tube  1496 . In some embodiments, the support tube  1495  is adhered or otherwise secured to the central tube  1496  only at a proximal end of the support tube  1495 . In other embodiments, the support tube  1495  may be adhered or otherwise secured to the central tube  1496  along substantially an entire length of the support tube  1495 . Other arrangements are contemplated. 
     The support tube  1495  may have an inner diameter that is only slightly, narrowly, marginally, or minimally larger than; is approximately the same as; conforms or substantially conforms with; and/or substantially inhibits, limits, and/or prevents lateral movements of an outer diameter of the central tube  1496 . The support tube  1495  can be in a fixed longitudinal relationship with the central tube  1496  so as to move in unison therewith, while preventing lateral movement of the central tube  1496  within a lumen of the support tube  1495  that otherwise would bend, kink, and/or buckle the central tube  1496 . In various embodiments, the inner diameter of the support tube  1495  is no greater than 5, 10, 15, 20, 25, or 30 percent larger than the outer diameter of the central tube  1496 . 
     With reference to  FIG.  56 A , a distal tip or distal edge of the support tube  1495  can correspond to a distal terminus  1450  of the medial segment  1424 . Although the central tube  1496  may extend continuously through the distal terminus  1450 , the medial and distal segments  1424 ,  1426  may still be said to meet at an interface  1452  at the distal terminus  1450  of the medial segment  1424 . 
     As with other embodiments disclosed herein, in some embodiments, the interface  1452  may be positioned within a reinforcement tube  1432  when the cannula  1404  is in the retracted state, as shown in  FIG.  56 A . As the cannula is advanced distally, the support tube  1495  moves in tandem with the central tube  1496  that it encompasses and slides distally within the reinforcement tube  1432 . 
     In some instances, the access system  1400  can be particularly well suited for use with closed catheter systems. The access system  1400  may be coupled and used with the closed catheter system  700  in a manner such as described above with respect to the access system  1200  in  FIGS.  33  and  34   . 
       FIGS.  57  and  58    depict another embodiment of an access system  1500 . In some embodiments, the access system  1500  can be particularly well suited for use with an open catheter system, whether with or without an extension set. The access system  1500  can include a cannula  1504  that is substantially the same as the cannula  1404  just discussed with respect to the access system  1400 . In particular, the cannula  1404  can include a central tube and a support member that encompasses the central tube. Other arrangements for the cannula  1504 , including those discussed elsewhere herein, are also contemplated. 
     The access system  1500  can further include a sealing member  1600  coupled with a reinforcement tube  1532  and the cannula  1504 . An open catheter system may not include a sealing member or valve that could seal against the cannula  1504  during use. The sealing member  1600  can prevent blood that might pass proximally through an annular space between the reinforcement tube  1532  and the cannula  1504  from egressing from a proximal end of the reinforcement tube  1532  and into a housing of the access system  1500 . 
       FIG.  59    provides a more detailed view of in internal portion of the access assembly  1500  that includes the sealing member  1600 . The sealing member  1600  can be fixedly secured to a proximal end of the reinforcement tube  1532 . The proximal end of the sealing member can include a proximal opening  1602  through which a support tube  1595  of the cannula  1504  passes. The sealing member  1600  can form a static seal with the reinforcement tube  1532  and can form a dynamic seal with the support tube  1595 . Stated otherwise, the sealing member  1600  can be in a fixed relation relative to the reinforcement tube  1532 , yet can permit movement of the support tube  1595  relative thereto, while the sealing member  1600  maintains a fluid tight seal with each of the reinforcement tube  1532  and the support tube  1595 . The sealing member  1600  can prevent blood from egressing from the support tube  1595  and through the proximal opening  1602 . 
       FIG.  60    depicts another embodiment of a sealing member  1700 , which can resemble the sealing member  1600  in many respects. The sealing member  1700  includes a proximal opening  1702  and a strain-relief region  1704  at a proximal end of the sealing member  1700 . In particular, a distal end of an internal cavity  1706  defined by the sealing member  1700  can have a reduced diameter D 1  at which the sealing member  1700  tightly grips the reinforcing member  1532  and forms a static, fluid-tight seal therewith. A proximal end of the internal cavity  1704  can have an undercut or expanded region defining an expanded diameter D 2 . In the expanded proximal region, the sealing member  1700  may be recessed or spaced from an external surface of the reinforcement member  1532  when the access system  1500  is fully assembled. This can, in some instances, permit readier movement of the support tube  1595  through the proximal end of the sealing member  1700  as the support tube  1595  is moved through the proximal opening  1702 , thus maintaining a secure, dynamic, fluid-tight seal between the sealing member  1700  and the support tube  1595 . The expanded diameter can permit readier flexion of the proximal end of the sealing member  1700 . 
       FIG.  61    is a perspective view of another embodiment of an access system  1800  in a retracted state.  FIG.  62    is a cross-sectional view of the access system  1800  in the retracted state. The access system  1800  includes a tab  1898  that extends through a longitudinal track  1899  in the housing element. The tab  1898  is attached to an internal coupler  1861 , that can resemble previously described followers in general configuration, but can differ significantly therefrom in its connection to the externally positioned tab  1898 . The internal coupler  1861  may alternatively be referred to as a follower, although it differs from other followers herein described in at least one significant respect. Whereas the other followers move solely in response to forces applied to the cannula, the internal coupler  1861  may additionally move in response to forces applied to the tab  1898 . Regardless, the internal coupler  1861  does not instigate or otherwise cause movement of a cannula  1804  to which it is attached. Movements of the internal coupler  1861  are purely passive and in response to either movement of the cannula  1804  or movement of the tab  1898 . The internal coupler  1861  can be connected with portions of a cannula  1804 , such that the cannula  1804  can be moved in response to movement of the tab  1898 . The tab  1898  can be used to move the internal coupler  1861  forwardly and rearwardly along the designated track  1898  and thereby advance and retract the cannula  1804 . 
       FIG.  63    is a perspective cross-sectional view of another embodiment of an access system  1900  that includes a deployable cannula  1904 .  FIG.  64    is a cross-sectional view of a generally distal portion of the access system  1900 . The cannula  1904  includes a unitary central tube  1996  (e.g., formed of a polymeric material) without any support tube attached thereto. The central tube  1996  is attached at its proximal end to a proximal  1923 . The access system  1900  includes a reinforcement member  1930  at a distal end thereof that is defined by a connection member  1970 . 
     Methods of using embodiments of access systems are discussed above. Certain methods can include placing a base catheter system in the vasculature of a patient. Other or further methods can include coupling an access system with a pre-placed base catheter system. In certain embodiments, the base catheter system may be placed in one or more of a dorsal arch of a hand, a forearm, or an antecubital fossa position on a patient. Various embodiments disclosed herein are capable for use with pre-placed base catheter systems that have been placed at any of these regions. For example, the access systems may include supported cannula that are capable of use with base catheter tubes that may define significantly tortuous paths. 
     In some instances, the base catheter system may be placed on the patient in a typical fashion that does not involve the use of special spacing or orientation apparatus. For example, some embodiments of access systems may be used with base catheter systems that have been taped down to the skin of the patient or secured to the skin of the patient with a standard flat dressing. There may be no spacing element present, such as a wedge-shaped device configured to provide an entry angle for the access system. That is, the access systems may be usable through a tortuous region defined by a base catheter system that is taped or otherwise secured directly to the skin of the patient. 
     EXAMPLES 
     The present paragraph recites  322  illustrative examples of systems, kits, and methods that correspond with various embodiments of the foregoing written description and/or the illustrative drawings. In these examples, the terminology “Example X to Example Y” means Example X through Example Y, and thus includes the endpoints of the recited range of examples. 
     Example 1. An access system comprising: 
     a connector configured to couple with a catheter assembly that comprises a catheter tube configured to be positioned in a blood vessel of a patient; 
     a reinforcement member coupled with the connector; and 
     a cannula movable relative to the reinforcement member from a retracted position in which at least a portion of the cannula is within the reinforcement member to an advanced position, the cannula comprising:
         a first segment at a distal end of the cannula that defines a distal tip of the cannula; and   a second segment that is relatively stiffer than the first segment and extends proximally from the first segment, the second segment comprising a distal terminus that is configured to be within the reinforcement member when the distal tip of the cannula is first positioned distal of and external to the reinforcement member as the cannula is transitioned from the retracted position to the advanced position,       

     wherein, when the connector and the catheter assembly are in a coupled state, at least a portion of the first segment of the cannula is configured to be advanced through at least a portion of the catheter tube as the cannula is transitioned from the retracted position to the advanced position. 
     Example 2. The access system of Example 1, wherein the catheter assembly is configured to be preplaced in the patient such that the catheter tube is positioned in the blood vessel of the patient prior to coupling of the connector of the access system with the catheter assembly.
 
Example 3. The access system of Example 1 or Example 2, wherein, when the catheter tube of the catheter assembly is positioned in the blood vessel of the patient and when the connector of the access system and the catheter assembly are in the coupled state, advancement of the cannula to the advanced position enables fluid communication directly between the cannula and the blood vessel.
 
Example 4. The access system of any one of Example 1 to Example 3, wherein when the cannula is in the advanced position, the distal tip of the cannula extends distally past a distal tip of the catheter tube.
 
Example 5. The access system of any one of Example 1 to Example 3, wherein when the cannula is in the advanced position, the distal tip of the cannula is positioned within the catheter tube at or proximate to a distal tip of the catheter tube.
 
Example 6. The access system of any one of Example 1 to Example 5, wherein when the cannula is in the advanced position, said at least a portion of the cannula is positioned outside of and distal to a distal tip of the reinforcement member.
 
Example 7. The access system of any one of Example 1 to Example 6, wherein the second segment of the cannula is relatively harder than the first segment of the cannula.
 
Example 8. The access system of any one of Example 1 to Example 7, wherein the second segment of the cannula comprises a flexible and/or polymeric tube and a support member that is stiffer than and encompasses at least a portion of the flexible and/or polymeric tube.
 
Example 9. The access system of Example 8, wherein at least a distal end of the support member is encompassed by the reinforcement member when the cannula is in the retracted position.
 
Example 10. The access system of Example 8 or Example 9, wherein at least an intermediate portion of the flexible and/or polymeric tube that continuously extends along at least a portion of each of the first and second segments is encompassed by one or more of the reinforcement member and the support member along a full length of the intermediate portion when the cannula is in the retracted position.
 
Example 11. The access system of any one of Example 8 to Example 10, wherein the support member advances distally through the reinforcement member throughout movement of the cannula from the retracted position to the advanced position.
 
Example 12. The access system of any one of Example 8 to Example 11, wherein the distal terminus comprises a distal tip of the support member.
 
Example 13. The access system of any one of Example 8 to Example 12, wherein the flexible and/or polymeric tube fits snugly within the support member.
 
Example 14. The access system of any one of Example 8 to Example 13, wherein the support member is fixed relative to the flexible and/or polymeric tube.
 
Example 15. The access system of Example 14, wherein the support member is adhered to the flexible and/or polymeric tube.
 
Example 16. The access system of any one of Example 8 to Example 15, wherein the flexible and/or polymeric tube extends through a full length of the support member.
 
Example 17. The access system of any one of Example 8 to Example 16, wherein the support member extends along a full length of the second segment.
 
Example 18. The access system of any one of Example 8 to Example 17, wherein the cannula further comprises a third segment that extends proximally from the second segment.
 
Example 19. The access system of Example 18, wherein the third segment comprises a proximal tube having an outer diameter that is larger than an outer diameter of the flexible and/or polymeric tube.
 
Example 20. The access system of Example 18 or Example 19, wherein the flexible and/or polymeric tube is fixedly secured to the proximal tube.
 
Example 21. The access system of any one of Example 18 to Example 20, further comprising a follower attached to each of the second and third segments.
 
Example 22. The access system of any one of Example 8 to Example 20, wherein the first segment comprises a portion of the flexible and/or polymeric tube.
 
Example 23. The access system of Example 22, wherein the first segment is formed exclusively from the flexible and/or polymeric tube.
 
Example 24. The access system of Example 22, wherein the flexible and/or polymeric tube is formed of a unitary piece of material that extends continuously from the first segment to the second segment.
 
Example 25. The access system of any one of Example 8 to Example 24, wherein the flexible and/or polymeric tube is formed of polyimide.
 
Example 26. The access system of any one of Example 8 to Example 25, wherein the support member comprises a support tube that circumscribes an outer surface of the flexible and/or polymeric tube.
 
Example 27. The access system of Example 26, wherein the support tube comprises a metallic material.
 
Example 28. The access system of Example 27, wherein the support tube is formed of stainless steel.
 
Example 29. The access system of any one of Example 8 to Example 28, wherein the support member is sized to slide through at least a portion of the reinforcement member as the cannula is transitioned from the retracted position to the advanced position.
 
Example 30. The access system of any one of Example 8 to Example 29, further comprising a sealing member coupled to each of the reinforcement member and the support member so as to form a fluid-tight seal to prevent ingress of fluid into or egress of fluid from a space between the reinforcement member and the support member.
 
Example 31. The access system of Example 30, wherein the sealing member is fixedly secured to the reinforcement member and the support member is movable relative to the sealing member.
 
Example 32. The access system of Example 30 or Example 31, wherein the sealing member is attached to a proximal end of the reinforcement member.
 
Example 33. The access system of any one of Example 30 to Example 32 wherein the sealing member encompasses a proximal tip of the reinforcement member.
 
Example 34. The access system of any one of Example 8 to Example 33, wherein the reinforcement member defines a lumen that defines an inner diameter that is no greater than 20 percent larger than an outer diameter of the support member.
 
Example 35. The access system of any one of Example 8 to Example 34, wherein the support member prevents kinking of the flexible and/or polymeric tube when the first segment encounters force resistive to distal advancement of the distal tip of the cannula by preventing lateral movement of the flexible and/or polymeric tube within the support member in an amount that otherwise would be sufficient to kink the flexible and/or polymeric tube.
 
Example 36. The access system of any one of Example 1 to Example 7, wherein the first segment comprises a first tube that comprises a first end face, the second segment comprises a second tube that comprises a second end face, and the first and second end faces abut one another at an interface positioned at the distal terminus of the second segment.
 
Example 37. The access system of Example 36, wherein each of the first and second end faces is transversely oriented relative to a longitudinal axis of the cannula.
 
Example 38. The access system of Example 36 or Example 37, wherein the second tube is stiffer than the first tube.
 
Example 39. The access system of Example 38, wherein the second tube is formed of a metallic material
 
Example 40. The access system of Example 39, wherein the second tube is formed of stainless steel.
 
Example 41. The access system of any one of Example 36 to Example 40, wherein the first tube is formed of a polymeric material.
 
Example 42. The access system of any one of Example 36 to Example 41, further comprising a tie layer extending over the interface and at least a portion of each of the first and second tubes of the first and second segments, respectively, to attach the first and second tubes together or to reinforce an attachment between the first and second tubes.
 
Example 43. The access system of Example 42, wherein an outer diameter of the first tube and an outer diameter of the second tube are substantially identical in at least a region of the cannula that includes the interface.
 
Example 44. The access system of Example 42 or Example 43, wherein an outer diameter of the tie layer is substantially constant along a transition region that includes a proximal end of the first segment, the interface, and a distal end of the second segment.
 
Example 45. The access system any one of Example 42 to Example 44, wherein the tie layer comprises a tubular member that defines a thickness that is no less than five times smaller than a thickness of the first tube.
 
Example 46. The access system of any one of Example 42 to Example 45, wherein the tie layer comprises a tube formed of heat shrinkable material.
 
Example 47. The access system of any one of Example 42 to Example 46, wherein a hardness of the tie layer is less than a hardness of the first segment.
 
Example 48. The access system of any one of Example 42 to Example 47, wherein a distal tip of the tie layer is proximally spaced from the distal tip of the cannula, and wherein the distal tip of the tie layer is configured to contact an internal surface of the catheter tube to delimit proximal movement of the cannula relative to the catheter tube.
 
Example 49. The access system of any one of Example 42 to Example 48, wherein a distal tip of the tie layer is proximally spaced from the distal tip of the cannula, and wherein the distal tip of the tie layer is configured to contact an internal surface of the catheter tube to provide tactile feedback to a user regarding a position of the cannula relative to the catheter tube.
 
Example 50. The access system of any one of Example 1 to Example 49, wherein the reinforcement member prevents kinking of the first segment when the first segment encounters force resistive to distal advancement of the distal tip of the cannula by preventing lateral movement of the first segment within the reinforcement member in an amount that otherwise would be sufficient to kink the first segment.
 
Example 51. The access system of any one of Example 1 to Example 50, wherein an inner diameter of the first segment is no greater than an inner diameter of the second segment.
 
Example 52. The access system of any one of Example 1 to Example 50, wherein an inner diameter of the first segment and an inner diameter of the second segment are substantially identical in at least a region of the cannula that includes the terminus.
 
Example 53. The access system of any one of Example 1 to Example 52, wherein the reinforcement member defines a lumen that defines an inner diameter that is no greater than 20 percent larger than an outer diameter of the first segment of the cannula.
 
Example 54. The access system of Example 53, wherein the inner diameter of the lumen is constant along a tubular region that extends along at least a portion of a full length of the reinforcement member.
 
Example 55. The access system of Example 54, wherein the tubular region extends to a distal tip of the reinforcement member.
 
Example 56. The access system of Example 54 or Example 55, wherein the tubular region extends along at least a majority of the full length of the reinforcement member.
 
Example 57. The access system of any one of Example 1 to Example 56, wherein the reinforcement member comprises a stainless steel tube.
 
Example 58. The access system of Example 57, wherein the reinforcement member further comprises a polymeric material overmolded onto the stainless steel tube.
 
Example 59. The access system of any one of Example 1 to Example 56, wherein the connector and the reinforcement member are integrally formed of a unitary piece of material.
 
Example 60. The access system of Example 59, wherein the unitary piece of material is polymeric.
 
Example 61. The access system of any one of Example 1 to Example 60, wherein the first segment is shorter than the reinforcement member.
 
Example 62. The access system of any one of Example 1 to Example 60, wherein the first segment is longer than the reinforcement member.
 
Example 63. The access system of any one of Example 1 to Example 62, wherein the distal tip of the cannula is positioned within the reinforcement member when the cannula is in the retracted position, such that the distal tip of the cannula is first positioned distal of and external to the reinforcement member only after the cannula has been moved from the retracted position.
 
Example 64. The access system of any one of Example 1 to Example 62, wherein the distal tip of the cannula is first positioned distal of and external to the reinforcement member when the cannula is in the retracted position.
 
Example 65. The access system of any one of Example 1 to Example 64, wherein the distal terminus of the second segment of the cannula is within the reinforcement member when the cannula is in the retracted position.
 
Example 66. The access system of any one of Example 1 to Example 65, wherein the distal terminus of the second segment of the cannula is distal to a distal edge of the reinforcement member when the cannula is in the advanced position.
 
Example 67. The access system of any one of Example 1 to Example 66, wherein the catheter assembly comprises an extension set that comprises a hub, wherein the distal terminus of the second segment of the cannula is positioned within the hub when the cannula is in the advanced position.
 
Example 68. The access system of any one of Example 1 to Example 66, wherein the catheter assembly comprises a catheter hub coupled to the catheter tube, wherein the distal terminus of the second segment of the cannula is positioned within the catheter hub when the cannula is in the advanced position.
 
Example 69. The access system of any one of Example 1 to Example 65, wherein the distal terminus of the second segment of the cannula is within the reinforcement member when the cannula is in the advanced position.
 
Example 70. The access system of any one of Example 1 to Example 65, wherein the distal terminus of the second segment of the cannula is within the reinforcement member throughout movement of the cannula from the retracted position to the advanced position.
 
Example 71. The access system of any one of Example 1 to Example 70, further comprising a sheath coupled to the connector, wherein the cannula extends through at least a portion of the sheath, the cannula being movable relative to the sheath from the retracted position to the advanced position.
 
Example 72. The access system of Example 71, wherein at least a portion of the sheath and at least a portion of the connector are integrally formed of a unitary piece of material.
 
Example 73. The access system of Example 71 or Example 72, wherein, when the cannula is in each of the retracted and advanced positions, at least some portion of the cannula is positioned within the sheath.
 
Example 74. The access system of any one of Example 71 to Example 73, wherein at least some portion of the cannula is positioned within the sheath throughout movement of the cannula from the retracted position to the advanced position.
 
Example 75. The access system of any one of Example 71 to Example 74, wherein the sheath comprises a tube having a proximal end and a distal end, and wherein the cannula extends through at least the proximal end of the sheath when in the retracted position and extends through at least the distal end of the sheath when in the advanced position.
 
Example 76. The access system of any one of Example 71 to Example 75, further comprising a follower fixedly attached to the cannula and positioned within the sheath, wherein the follower moves in unison with the cannula as the cannula is moved from the retracted position to the advanced position.
 
Example 77. The access system of Example 76, wherein the follower cooperates with the sheath to delimit proximal movement of the cannula relative to the sheath.
 
Example 78. The access system of Example 76 or Example 77, wherein the follower and the sheath comprise a rotational alignment mechanism by which a rotational orientation of the cannula is maintained relative to the sheath.
 
Example 79. The access system of Example 78, wherein the rotational alignment mechanism comprises a protrusion positioned within a groove, wherein the sheath defines one of the protrusion and the groove and the follower defines the other of the protrusion and the groove.
 
Example 80. The access system of any one of Example 76 to Example 79, wherein:
 
     the reinforcement member comprises a reinforcing tube that is movable relative to the connector; 
     the follower is coupled to the reinforcing tube while the cannula is in the retracted position such that the follower and the reinforcing tube move distally in tandem with the cannula throughout movement of the cannula from the retracted position to an intermediate position that is proximal of the advanced position; and 
     the follower is configured to decouple from the reinforcing tube as the cannula is moved distally past the intermediate position. 
     Example 81. The access system of Example 80, wherein when the follower decouples from the reinforcing tube, the follower and the cannula are permitted to move distally relative to the reinforcing tube while the reinforcing tube remains fixed relative to the connector.
 
Example 82. The access system of Example 80 or Example 81, further comprising a catch fixedly attached to the reinforcing tube, wherein the follower comprises a plurality of arms that grasp the catch throughout movement of the cannula from the retracted position to the intermediate position and release the catch as the cannula is moved distally past the intermediate position.
 
Example 83. The access system of Example 82, wherein:
 
     the sheath comprises a first chamber that defines a first diameter and a second chamber positioned distal of the first chamber that defines a second diameter larger than the first diameter; 
     the first chamber of the sheath is sized to constrain at least distal ends of the plurality of arms from flexing outwardly while the distal ends are positioned in the first chamber such that the arms engage the catch while in the first chamber; and 
     the second chamber of the sheath is sized to permit the distal ends of the plurality of arms to flex outwardly to disengage from the catch and to move distally past the catch. 
     Example 84. The access system of Example 83, wherein a proximal end of the second chamber is proximal of the intermediate position. 
     Example 85. The access system of Example 83 or Example 84, wherein the plurality of arms are outwardly biased such that the distal ends of the plurality of arms automatically flex outwardly and disengage from the catch when advanced through the second chamber of the sheath.
 
Example 86. The access system of Example 83 or Example 84, wherein the plurality of arms and the catch comprise a ramped interface that causes the distal ends of the plurality of arms to flex outwardly and disengage from the catch when positioned in the second chamber of the sheath and when the reinforcing tube encounters increased resistance to distal movement as the cannula is advanced toward the advanced position.
 
Example 87. The access system of any one of Example 71 to Example 86, further comprising an actuator attached to the cannula, wherein at least a portion of the actuator is accessible external to the sheath so as to be manipulated to move the cannula between the advanced and retracted positions.
 
Example 88. The access system of Example 87, wherein the sheath comprises a longitudinally extending track, and wherein a portion of the actuator extends through the track.
 
Example 89. The access system of any one of Example 71 to Example 88, wherein the cannula is moved from the retracted position to the advanced position by directly contacting the cannula.
 
Example 90. The access system of any one of Example 1 to Example 89, wherein the connector comprises a threaded region that is configured to cooperate with a complementary portion of the catheter assembly to securely couple the connector with the catheter assembly.
 
Example 91. The access system of any one of Example 1 to Example 89, wherein the connector comprises at least two flaps that are configured to cooperate with a portion of the catheter assembly to securely snap the connector onto the catheter assembly.
 
Example 92. The access system of any one of Example 1 to Example 91, wherein the cannula comprises a further connector at a proximal end thereof for connecting the cannula to a fluid transfer device.
 
Example 93. The access system of Example 92, wherein the fluid transfer device comprises a blood collection unit.
 
Example 94. The access system of Example 92 of Example 93, wherein the further connector comprises a luer fitting.
 
Example 95. The access system of any one of Example 1 to Example 94, wherein the cannula is further movable from the advanced position to the retracted position.
 
Example 96. The access system of any one of Example 1 to Example 95, wherein when the cannula is in the advanced position, a length of the cannula extends through the reinforcement member.
 
Example 97. The access system of Example 96, wherein the second segment of the cannula defines at least a portion of the length of the cannula that extends through the reinforcement member when the cannula is in the advanced position.
 
Example 98. The access system of any one of Example 1 to Example 97, wherein:
 
     the catheter assembly comprises a septum; and 
     a distal tip of the reinforcement member is configured to be positioned proximal to the septum when the connector is attached to the catheter assembly. 
     Example 99. The access system of any one of Example 1 to Example 97, wherein: 
     the catheter assembly comprises a septum; 
     the reinforcement member comprises a projection that extends distally from a surface of the connector; and 
     at least a portion of the projection of the reinforcement member is configured to extend through the septum of the catheter assembly when the connector is attached to the catheter assembly. 
     Example 100. The access system of Example 99, wherein the septum comprises an opening that is in an unsealed state prior to insertion of the projection of the reinforcement member through the septum. 
     Example 101. The access system of Example 100, wherein the projection of the reinforcement member is configured to be inserted through the opening of the septum. 
     Example 102. The access system of any one of Example 99 to Example 101, wherein the projection extends distally past a distal end of the connector. 
     Example 103. The access system of any one of Example 99 to Example 101, wherein the projection is proximally recessed relative to a distal end of the connector. 
     Example 104. The access system of any one of Example 99 to Example 104, wherein the catheter assembly further comprises a valve positioned distal to the septum. 
     Example 105. The access system of Example 104, wherein, when the connector is coupled with the catheter assembly, no portion of the reinforcement member extends through the valve. 
     Example 106. The access system of Example 104 or Example 105, wherein, when the connector is coupled with the catheter assembly, a distal tip of the reinforcement member is at or proximally spaced from a proximal surface of the valve. 
     Example 107. The access system of any one of Example 104 to Example 106, wherein, when the connector is coupled with the catheter assembly, a portion of the reinforcement member extends through the septum. 
     Example 108. The access system of any one of Example 104 to Example 107, wherein, when the connector is coupled with the catheter assembly, the reinforcement member aims the cannula toward a sealable opening of the valve such that the distal tip of the cannula is advanced through the sealable opening of the valve as the cannula is moved from the retracted position to the advanced position.
 
Example 109. The access system of Example 108, wherein the sealable opening is substantially centered relative to the valve, and wherein, when the connector is coupled with the catheter assembly, the reinforcement member is substantially centered so as to be aligned with the sealable opening.
 
Example 110. The access system of any one of Example 104 to Example 109, wherein, when the cannula is in the advanced position, at least a portion of the second segment of the cannula extends through the valve.
 
Example 111. The access system of Example 110, wherein, when the cannula is in the advanced position, the distal terminus of the second segment of the cannula is distal to the valve.
 
Example 112. The access system of any one of Example 99 to Example 111, wherein the catheter assembly further comprises a removable piercing member that extends through the septum and through the catheter tube to assist in positioning the catheter tube in the blood vessel of the patient, and wherein the piercing member is configured to be removed from the catheter assembly prior to coupling the connector of the access system with the catheter assembly.
 
Example 113. The access system of Example 112, wherein the removable piercing member further extends through the valve when extending through the septum and through the catheter tube.
 
Example 114. The access system of any one of Example 1 to Example 97, wherein the catheter assembly is a closed intravenous catheter system.
 
Example 115. The access system of Example 114, wherein the closed intravenous catheter system comprises an integrated side port through which fluid may be transferred to or from the catheter tube.
 
Example 116. The access system of any one of Example 1 to Example 97, wherein the catheter assembly is an open intravenous catheter system.
 
Example 117. The access system of any one of Example 1 to Example 116, wherein an entirety of the reinforcement member is external to the catheter tube when the connector is coupled with the catheter assembly.
 
Example 118. The access system of Example 117, wherein the entirety of the reinforcement member remains external to the catheter tube throughout movement of the cannula from the retracted position to the advanced position.
 
Example 119. The access system of any one of Example 1 to Example 118, wherein a distal tip of the reinforcement member is proximal to a proximal tip the catheter tube when the connector is coupled with the catheter assembly.
 
Example 120. The access system of Example 119, wherein the distal tip of the reinforcement member remains proximal to the proximal tip of the catheter tube throughout movement of the cannula from the retracted position to the advanced position.
 
Example 121. The access system of Example 1, wherein the reinforcement member is fixed relative to the connector.
 
Example 122. The access system of Example 1, wherein the reinforcement member comprises a first metallic hypotube, and wherein the second segment comprises a second metallic hypotube sized to translate within the first metallic hypotube.
 
Example 123. The access system of Example 122, wherein each of the first and second segments is at least partially defined by a unitary polymeric tube, and wherein the second metallic hypotube encompasses a portion of the polymeric tube.
 
Example 124. The access system of Example 122 or Example 123, wherein a distal tip of the second metallic hypotube defines the distal terminus of the second segment.
 
Example 125. The access system of any one of Example 1 to Example 124, further comprising the catheter assembly.
 
Example 126. A kit comprising:
 
     an access system according to any one of Example 1 to Example 125; and 
     instructions for using the kit, the instructions comprising directions to:
         couple the connector to the catheter assembly while the catheter tube of the catheter assembly is positioned in the blood vessel of the patient; and   advance the cannula from the retracted position to the advanced position.
 
Example 127. The kit of Example 126, wherein the instructions for using the kit further comprise directions to:
       

     couple a fluid transfer device to the cannula; and 
     draw blood from the blood vessel through the cannula and into the fluid transfer device. 
     Example 128. A method of using the access system of any one of Example 1 to Example 125, the method comprising: 
     coupling the connector to the catheter assembly while the catheter tube of the catheter assembly is positioned in the blood vessel of the patient; and 
     advancing the cannula from the retracted position to the advanced position. 
     Example 129. An access system comprising: 
     a connector configured to couple with a catheter assembly that comprises a catheter tube configured to be positioned in a blood vessel of a patient; 
     a reinforcement member coupled with the connector; and 
     a cannula movable relative to the reinforcement member from a retracted position in which at least a portion of the cannula is within the reinforcement member to an advanced position, the cannula comprising:
         a flexible and/or polymeric tube that defines a distal tip; and   a support tube that is stiffer than and encompasses a portion of the flexible and/or polymeric tube, the support tube defining a distal edge that is configured to be within the reinforcement member when the distal tip of the flexible and/or polymeric tube is first positioned distal of and external to the reinforcement member as the cannula is transitioned from the retracted position to the advanced position,       

     wherein, when the connector and the catheter assembly are in a coupled state, at least a portion of the flexible and/or polymeric tube is configured to be advanced through at least a portion of the catheter tube as the cannula is transitioned from the retracted position to the advanced position. By flexible and/or polymeric tube, it is meant that in some embodiments, the cannula comprises a flexible tube (whether or not the tube is polymeric), while in other or further embodiments, the cannula comprises a polymeric tube, which can have properties such as described in the present disclosure. 
     Example 130. An access system comprising: 
     a connector configured to couple with a catheter assembly that comprises a catheter tube configured to be positioned in a blood vessel of a patient; 
     a reinforcement member coupled with the connector; and 
     a cannula movable relative to the reinforcement member from a retracted position in which at least a portion of the cannula is within the reinforcement member to an advanced position, the cannula comprising:
         a flexible and/or polymeric tube that defines a distal tip; and   a support tube that encompasses a portion of the flexible and/or polymeric tube, the support tube being in a fixed relationship with the flexible and/or polymeric tube so as to move in unison with the flexible and/or polymeric tube as the cannula is transitioned from the retracted position to the advanced position,       

     wherein, when the connector and the catheter assembly are in a coupled state, at least a portion of the flexible and/or polymeric tube is configured to be advanced through at least a portion of the catheter tube as the cannula is transitioned from the retracted position to the advanced position. 
     Example 131. An access system comprising: 
     a connector configured to couple with a catheter assembly that comprises a catheter tube configured to be positioned in a blood vessel of a patient; 
     a reinforcement member coupled with the connector; and 
     a cannula movable relative to the reinforcement member from a retracted position in which at least a portion of the cannula is within the reinforcement member to an advanced position, the cannula comprising:
         a flexible and/or polymeric tube that defines a distal tip; and   a support tube that encompasses a portion of the flexible and/or polymeric tube, the support tube defining a distal edge that is proximally spaced from the distal tip of the flexible and/or polymeric tube,       

     wherein, when the connector and the catheter assembly are in a coupled state, at least a portion of the flexible and/or polymeric tube is configured to be advanced through at least a portion of the catheter tube as the cannula is transitioned from the retracted position to the advanced position. 
     Example 132. The access system of any one of Example 129 to Example 131, wherein, at each stage throughout movement of the cannula from the retracted position to the advanced position, at least some portion of the support tube is positioned within the reinforcement member.
 
Example 133. The access system of any one of Example 129 to Example 132, wherein the flexible and/or polymeric tube comprises polyimide.
 
Example 134. The access system of any one of Example 129 to Example 133, wherein the distal edge of the support tube is configured to extend distally past a distal tip of the reinforcement member when the cannula is in the advanced position.
 
Example 135. The access system of any one of Example 129 to Example 134, wherein the distal tip of the flexible and/or polymeric tube is positioned within the reinforcement member when the cannula is in the retracted position, such that the distal tip of the flexible and/or polymeric tube is first positioned distal of and external to the reinforcement member only after the cannula has been moved from the retracted position.
 
Example 136. The access system of any one of Example 129 to Example 134, wherein the distal tip of the flexible and/or polymeric tube is first positioned distal of and external to the reinforcement member when the cannula is in the retracted position.
 
Example 137. The access system of any one of Example 129 to Example 136, wherein the distal edge of the support tube is within the reinforcement member when the cannula is in the retracted position.
 
Example 138. The access system of any one of Example 129 to Example 137, wherein the distal edge of the support tube is distal to a distal edge of the reinforcement member when the cannula is in the advanced position.
 
Example 139. The access system of any one of Example 129 to Example 138, wherein the catheter assembly comprises an extension set that comprises a hub, wherein the distal edge of the support tube is positioned within the hub when the cannula is in the advanced position.
 
Example 140. The access system of any one of Example 129 to Example 138, wherein the catheter assembly comprises a catheter hub coupled to the catheter tube, wherein the distal edge of the support tube is positioned within the catheter hub when the cannula is in the advanced position.
 
Example 141. The access system of any one of Example 129 to Example 137, wherein the distal edge of the support tube is within the reinforcement member when the cannula is in the advanced position.
 
Example 142. The access system of Example 129 or Example 141, wherein the distal edge of the support tube is within the reinforcement member throughout movement of the cannula from the retracted position to the advanced position.
 
Example 143. The access system of any one of Example 129 to Example 142, further comprising a sheath coupled to the connector, wherein the cannula extends through at least a portion of the sheath, the cannula being movable relative to the sheath from the retracted position to the advanced position.
 
Example 144. The access system of Example 143, wherein at least a portion of the sheath and at least a portion of the connector are integrally formed of a unitary piece of material.
 
Example 145. The access system of Example 143 or Example 144, wherein, when the cannula is in each of the retracted and advanced positions, at least some portion of the cannula is positioned within the sheath.
 
Example 146. The access system of any one of Example 143 to Example 145, wherein at least some portion of the cannula is positioned within the sheath throughout movement of the cannula from the retracted position to the advanced position.
 
Example 147. The access system of any one of Example 143 to Example 146, wherein the sheath comprises a tube having a proximal end and a distal end, and wherein the cannula extends through at least the proximal end of the sheath when in the retracted position and extends through at least the distal end of the sheath when in the advanced position.
 
Example 148. The access system of any one of Example 143 to Example 147, further comprising a follower fixedly attached to the cannula and positioned within the sheath, wherein the follower moves in unison with the cannula as the cannula is moved from the retracted position to the advanced position.
 
Example 149. The access system of Example 148, wherein the follower cooperates with the sheath to delimit proximal movement of the cannula relative to the sheath.
 
Example 150. The access system of Example 148 or Example 149, wherein the follower and the sheath comprise a rotational alignment mechanism by which a rotational orientation of the cannula is maintained relative to the sheath.
 
Example 151. The access system of Example 150, wherein the rotational alignment mechanism comprises a protrusion positioned within a groove, wherein the sheath defines one of the protrusion and the groove and the follower defines the other of the protrusion and the groove.
 
Example 152. The access system of any one of Example 129 to Example 151, wherein:
 
     the catheter assembly comprises a septum; and 
     a distal tip of the reinforcement member is configured to be positioned proximal to the septum when the connector is attached to the catheter assembly. 
     Example 153. The access system of any one of Example 129 to Example 151, wherein: 
     the catheter assembly comprises a septum; 
     the reinforcement member comprises a projection that extends distally from a surface of the connector; and 
     at least a portion of the projection of the reinforcement member is configured to extend through the septum of the catheter assembly when the connector is attached to the catheter assembly. 
     Example 154. The access system of Example 153, wherein the septum comprises a sealable region that provides a fluid-tight seal prior to insertion of the projection of the reinforcement member through the sealable region. 
     Example 155. The access system of Example 153, wherein the septum comprises an opening that is in an unsealed state prior to insertion of the projection of the reinforcement member through the septum. 
     Example 156. The access system of Example 155, wherein the projection of the reinforcement member is configured to be inserted through the opening of the septum. 
     Example 157. The access system of any one of Example 153 to Example 156, wherein the projection extends distally past a distal end of the connector. 
     Example 158. The access system of any one of Example 153 to Example 156, wherein the projection is proximally recessed relative to a distal end of the connector. 
     Example 159. The access system of any one of Example 153 to Example 158, wherein the catheter assembly further comprises a valve positioned distal to the septum. 
     Example 160. The access system of Example 159, wherein, when the connector is coupled with the catheter assembly, no portion of the reinforcement member extends through the valve. 
     Example 161. The access system of Example 159 or Example 160, wherein, when the connector is coupled with the catheter assembly, a distal tip of the reinforcement member is at or proximally spaced from a proximal surface of the valve. 
     Example 162. The access system of any one of Example 159 to Example 161, wherein, when the connector is coupled with the catheter assembly, a portion of the reinforcement member extends through the septum. 
     Example 163. The access system of any one of Example 159 to Example 162, wherein, when the connector is coupled with the catheter assembly, the reinforcement member aims the cannula toward a sealable opening of the valve such that the distal tip of the flexible and/or polymeric tube is advanced through the sealable opening of the valve as the cannula is moved from the retracted position to the advanced position.
 
Example 164. The access system of Example 163, wherein the sealable opening is substantially centered relative to the valve, and wherein, when the connector is coupled with the catheter assembly, the reinforcement member is substantially centered so as to be aligned with the sealable opening.
 
Example 165. The access system of any one of Example 153 to Example 164, wherein the catheter assembly further comprises a removable piercing member that extends through the septum and through the catheter tube to assist in positioning the catheter tube in the blood vessel of the patient, and wherein the piercing member is configured to be removed from the catheter assembly prior to coupling the connector of the access system with the catheter assembly.
 
Example 166. The access system of any one of Example 159 to Example 165, wherein the removable piercing member further extends through the valve when extending through the septum and through the catheter tube.
 
Example 167. The access system of any one of Example 129 to Example 166, wherein the catheter assembly is a closed intravenous catheter system.
 
Example 168. The access system of Example 167, wherein the closed intravenous catheter system comprises an integrated side port through which fluid may be transferred to or from the catheter tube.
 
Example 169. The access system of any one of Example 129 to Example 166, wherein the catheter assembly is an open intravenous catheter system.
 
Example 170. The access system of any one of Example 129 to Example 169, further comprising a sealing member coupled to each of the reinforcement member and the support tube so as to form a fluid-tight seal to prevent ingress of fluid into or egress of fluid from a space between the reinforcement member and the support tube.
 
Example 171. The access system of Example 170, wherein the sealing member is fixedly secured to the reinforcement member and the support tube is movable relative to the sealing member.
 
Example 172. The access system of Example 170 or Example 171, wherein the sealing member is attached to a proximal end of the reinforcement member.
 
Example 173. The access system of any one of Example 170 to Example 172 wherein the sealing member encompasses a proximal tip of the reinforcement member.
 
Example 174. The access system of any one of Example 129 to Example 173, further comprising the catheter assembly.
 
Example 175. A kit comprising:
 
     an access system according to any one of Example 129 to Example 174; and 
     instructions for using the kit, the instructions comprising directions to:
         couple the connector to the catheter assembly while the catheter tube of the catheter assembly is positioned in the blood vessel of the patient; and   advance the cannula from the retracted position to the advanced position.
 
Example 176. The kit of Example 175, wherein the instructions for using the kit further comprise directions to:
       

     couple a fluid transfer device to the cannula; and 
     draw blood from the blood vessel through the cannula and into the fluid transfer device. 
     Example 177. A method of using the access system of any one of Example 129 to Example 174, the method comprising: 
     coupling the connector to the catheter assembly when the catheter tube of the catheter assembly is positioned in the blood vessel of the patient; and 
     advancing the cannula from the retracted position to the advanced position. 
     Example 178. An access system comprising: 
     a connector configured to couple with a closed intravenous catheter system that comprises a valve and a catheter tube that is configured to be positioned in a blood vessel of a patient; 
     a reinforcement member coupled with the connector such that when the connector is coupled with the closed intravenous catheter system, a distal tip of the reinforcement member is at or proximally spaced from a proximal surface of the valve; and 
     a cannula movable relative to the reinforcement member from a retracted position to an advanced position, 
     wherein, when the connector and the closed intravenous catheter system are in a coupled state, at least a portion of the cannula is configured to be advanced through the valve and through at least a portion of the catheter tube as the cannula is transitioned from the retracted position to the advanced position. 
     Example 179. An access system comprising: 
     a connector configured to couple with a closed intravenous catheter system that comprises a valve and a catheter tube that is configured to be positioned in a blood vessel of a patient; 
     a reinforcement member coupled with the connector such that when the connector is coupled with the closed intravenous catheter system, no portion of the reinforcement member is in contact with the valve; and 
     a cannula movable relative to the reinforcement member from a retracted position to an advanced position, 
     wherein, when the connector and the closed intravenous catheter system are in a coupled state, at least a portion of the cannula is configured to be advanced through the valve and through at least a portion of the catheter tube as the cannula is transitioned from the retracted position to the advanced position. 
     Example 180. An access system comprising: 
     a connector configured to couple with a closed intravenous catheter system that comprises a valve and a catheter tube that is configured to be positioned in a blood vessel of a patient; 
     a reinforcement member coupled with the connector such that when the connector is coupled with the closed intravenous catheter system, no portion of the reinforcement member extends through the valve; and 
     a cannula movable relative to the reinforcement member from a retracted position to an advanced position, 
     wherein, when the connector and the closed intravenous catheter system are in a coupled state, at least a portion of the cannula is configured to be advanced through the valve and through at least a portion of the catheter tube as the cannula is transitioned from the retracted position to the advanced position. 
     Example 181. The access system of any one of Example 178 to Example 180, wherein the closed intravenous catheter system is configured to be preplaced in the patient such that the catheter tube is positioned in the blood vessel of the patient prior to coupling of the connector of the access system with the closed intravenous catheter system.
 
Example 182. The access system of any one of Example 178 to Example 181, wherein, when the catheter tube of the closed intravenous catheter system is positioned in the blood vessel of the patient and when the connector of the access system and the closed intravenous catheter system are in the coupled state, advancement of the cannula to the advanced position enables fluid communication directly between the cannula and the blood vessel.
 
Example 183. The access system of any one of Example 178 to Example 182, wherein when the cannula is in the advanced position, a distal tip of the cannula extends distally past a distal tip of the catheter tube.
 
Example 184. The access system of any one of Example 178 to Example 182, wherein when the cannula is in the advanced position, a distal tip of the cannula is positioned within the catheter tube at or proximate to a distal tip of the catheter tube.
 
Example 185. The access system of any one of Example 178 to Example 184, wherein when the cannula is in the advanced position, at least a portion of the cannula is positioned outside of and distal to a distal tip of the reinforcement member.
 
Example 186. The access system of any one of Example 178 to Example 185, wherein the cannula comprises a first segment at a distal end thereof and a second segment that extends proximally from the first segment and is relatively stiffer than the first segment.
 
Example 187. The access system of Example 186, wherein the second segment of the cannula comprises a flexible and/or polymeric tube and a support member that encompasses at least a portion of the flexible and/or polymeric tube.
 
Example 188. The access system of Example 187, wherein the support member is in a fixed relation relative to the flexible and/or polymeric tube so as to move in unison therewith.
 
Example 189. The access system of Example 187 or Example 188, wherein at least a distal end of the support member is encompassed by the reinforcement member when the cannula is in the retracted position.
 
Example 190. The access system of any one of Example 187 to Example 189, wherein at least an intermediate portion of the flexible and/or polymeric tube that continuously extends along at least a portion of each of the first and second segments is encompassed by one or more of the reinforcement member and the support member along a full length of the intermediate portion.
 
Example 191. The access system of any one of Example 187 to Example 190, wherein the support member advances distally through the reinforcement member throughout movement of the cannula from the retracted position to the advanced position.
 
Example 192. The access system of any one of Example 187 to Example 191, wherein a distal tip of the support member corresponds with a distal terminus of the second segment.
 
Example 193. The access system of any one of Example 187 to Example 192, wherein the flexible and/or polymeric tube fits snugly within the support member.
 
Example 194. The access system of any one of Example 187 to Example 193, wherein the support member is fixedly secured to the flexible and/or polymeric tube.
 
Example 195. The access system of Example 194, wherein the support member is adhered to the flexible and/or polymeric tube.
 
Example 196. The access system of any one of Example 187 to Example 195, wherein the flexible and/or polymeric tube extends through a full length of the support member.
 
Example 197. The access system of any one of Example 187 to Example 196, wherein the support member extends along a full length of the second segment.
 
Example 198. The access system of any one of Example 187 to Example 197, wherein:
 
     the cannula further comprises a third segment that extends proximally from the second segment; 
     the third segment comprises a proximal tube having an outer diameter that is larger than an outer diameter of the flexible and/or polymeric tube; and 
     the flexible and/or polymeric tube is fixedly secured to the proximal tube. 
     Example 199. The access system of any one of Example 187 to Example 198, wherein the first segment comprises a portion of the flexible and/or polymeric tube. 
     Example 200. The access system of Example 199, wherein the first segment is formed exclusively from the flexible and/or polymeric tube. 
     Example 201. The access system of Example 199, wherein the flexible and/or polymeric tube is formed of a unitary piece of material that extends continuously from the first segment to the second segment. 
     Example 202. The access system of any one of Example 187 to Example 201, wherein the flexible and/or polymeric tube is formed of polyimide. 
     Example 203. The access system of any one of Example 187 to Example 202, wherein the support member comprises a support tube that circumscribes an outer surface of the flexible and/or polymeric tube. 
     Example 204. The access system of Example 203, wherein the support tube is formed of stainless steel. 
     Example 205. The access system of any one of Example 187 to Example 204, wherein the support member is sized to slide through at least a portion of the reinforcement member as the cannula is transitioned from the retracted position to the advanced position.
 
Example 206. The access system of any one of Example 187 to Example 205, wherein the reinforcement member defines a lumen that defines an inner diameter that is no greater than 20 percent larger than an outer diameter of the support member.
 
Example 207. The access system of any one of Example 187 to Example 206, wherein the support member prevents kinking of the flexible and/or polymeric tube when the first segment encounters force resistive to distal advancement of the distal tip of the cannula by preventing lateral movement of the flexible and/or polymeric tube within the support member in an amount that otherwise would be sufficient to kink the flexible and/or polymeric tube.
 
Example 208. The access system of Example 186, wherein the first segment comprises a first tube that comprises a first end face, the second segment comprises a second tube that comprises a second end face, and the first and second end faces abut one another at an interface positioned at the distal terminus of the second segment.
 
Example 209. The access system of Example 208, wherein each of the first and second end faces is transversely oriented relative to a longitudinal axis of the cannula.
 
Example 210. The access system of Example 208 or Example 209, wherein the second tube is formed of stainless steel.
 
Example 211. The access system of any one of Example 208 to Example 210, wherein the first tube is formed of a polymeric material.
 
Example 212. The access system of any one of Example 208 to Example 211, further comprising a tie layer extending over the interface and at least a portion of each of the first and second tubes of the first and second segments, respectively, to attach the first and second tubes together or to reinforce an attachment between the first and second tubes.
 
Example 213. The access system of Example 212, wherein an outer diameter of the first tube and an outer diameter of the second tube are substantially identical in at least a region of the cannula that includes the interface.
 
Example 214. The access system of Example 212 or Example 213, wherein an outer diameter of the tie layer is substantially constant along a transition region that includes a proximal end of the first segment, the interface, and a distal end of the second segment.
 
Example 215. The access system any one of Example 212 to Example 214, wherein the tie layer comprises a tubular member that defines a thickness that is no less than 20 times smaller than a thickness of the first tube.
 
Example 216. The access system of any one of Example 212 to Example 215, wherein the tie layer comprises a tube formed of heat shrinkable material.
 
Example 217. The access system of any one of Example 212 to Example 216, wherein a hardness of the tie layer is less than a hardness of the first segment.
 
Example 218. The access system of any one of Example 212 to Example 217, wherein a distal tip of the tie layer is proximally spaced from the distal tip of the cannula, and wherein the distal tip of the tie layer is configured to contact an internal surface of the catheter tube to delimit proximal movement of the cannula relative to the catheter tube.
 
Example 219. The access system of any one of Example 212 to Example 218, wherein a distal tip of the tie layer is proximally spaced from the distal tip of the cannula, and wherein the distal tip of the tie layer is configured to contact an internal surface of the catheter tube to provide tactile feedback to a user regarding a position of the cannula relative to the catheter tube.
 
Example 220. The access system of any one of Example 178 to Example 219, wherein the reinforcement member prevents kinking of the cannula when the cannula encounters force resistive to distal advancement of a distal tip of the cannula by preventing lateral movement of the cannula within the reinforcement member in an amount that otherwise would be sufficient to kink the cannula.
 
Example 221. The access system of any one of Example 178 to Example 220, wherein the reinforcement member defines a lumen that defines an inner diameter that is no greater than 20 percent larger than an outer diameter of a distal portion of the cannula.
 
Example 222. The access system of Example 221, wherein the inner diameter of the lumen is constant along a tubular region that extends along at least a majority of a full length of the reinforcement member.
 
Example 223. The access system of any one of Example 178 to Example 222, wherein a distal tip of the cannula is positioned within the reinforcement member when the cannula is in the retracted position, such that the distal tip of the cannula is first positioned distal of and external to the reinforcement member only after the cannula has been moved from the retracted position.
 
Example 224. The access system of any one of Example 178 to Example 222, wherein a distal tip of the cannula is first positioned distal of and external to the reinforcement member when the cannula is in the retracted position.
 
Example 225. The access system of any one of Example 178 to Example 224, wherein the cannula comprises a first distal segment that is relatively softer than a second segment that is proximally adjacent to the first segment, and wherein the second segment comprises a distal terminus that is within the reinforcement member when the cannula is in the retracted position.
 
Example 226. The access system of any one of Example 178 to Example 225, wherein the distal terminus of the second segment of the cannula is within the reinforcement member when the cannula is in the advanced position.
 
Example 227. The access system of Example 225 or Example 226, wherein the distal terminus of the second segment of the cannula is within the reinforcement member throughout movement of the cannula from the retracted position to the advanced position.
 
Example 228. The access system of any one of Example 178 to Example 225, wherein the distal terminus of the second segment of the cannula is distal to a distal tip of the reinforcement member when the cannula is in the advanced position.
 
Example 229. The access system of any one of Example 178 to Example 227, further comprising a sheath coupled to the connector, wherein the cannula extends through at least a portion of the sheath, the cannula being movable relative to the sheath from the retracted position to the advanced position.
 
Example 230. The access system of Example 229, wherein at least a portion of the sheath and at least a portion of the connector are integrally formed of a unitary piece of material.
 
Example 231. The access system of Example 229 or Example 230, wherein, when the cannula is in each of the retracted and advanced positions, at least some portion of the cannula is positioned within the sheath.
 
Example 232. The access system of any one of Example 229 to Example 231, wherein at least some portion of the cannula is positioned within the sheath throughout movement of the cannula from the retracted position to the advanced position.
 
Example 233. The access system of any one of Example 229 to Example 232, wherein the sheath comprises a tube having a proximal end and a distal end, and wherein the cannula extends through at least the proximal end of the sheath when in the retracted position and extends through at least the distal end of the sheath when in the advanced position.
 
Example 234. The access system of any one of Example 229 to Example 233, further comprising a follower fixedly attached to the cannula and positioned within the sheath, wherein the follower moves in unison with the cannula as the cannula is moved from the retracted position to the advanced position.
 
Example 235. The access system of Example 234, wherein the follower cooperates with the sheath to delimit proximal movement of the cannula relative to the sheath.
 
Example 236. The access system of Example 234 or Example 235, wherein the follower and the sheath comprise a rotational alignment mechanism by which a rotational orientation of the cannula is maintained relative to the sheath.
 
Example 237. The access system of Example 236, wherein the rotational alignment mechanism comprises a protrusion positioned within a groove, wherein the sheath defines one of the protrusion and the groove and the follower defines the other of the protrusion and the groove.
 
Example 238. The access system of any one of Example 229 to Example 237, further comprising an actuator attached to the cannula, wherein at least a portion of the actuator is accessible external to the sheath so as to be manipulated to move the cannula between the advanced and retracted positions
 
Example 239. The access system of Example 238, wherein the sheath comprises a longitudinally extending track, and wherein a portion of the actuator extends through the track.
 
Example 240. The access system of any one of Example 229 to Example 239, wherein the cannula is devoid of an actuator.
 
Example 241. The access system of any one of Example 229 to Example 240, wherein the cannula is moved from the retracted position to the advanced position by directly contacting the cannula.
 
Example 242. The access system of any one of Example 178 to Example 241, wherein the connector comprises a snap-fit arrangement that is configured to snap onto a hub of the closed intravenous catheter system to securely couple the connector to the closed intravenous catheter system.
 
Example 243. The access system of Example 242, wherein the snap-fit arrangement comprises two or more flexible flaps that are configured to selectively attach to the hub of the closed intravenous catheter system.
 
Example 244. The access system of any one of Example 178 to Example 243, wherein:
 
     the closed intravenous catheter system further comprises a septum spaced from the valve; and 
     a distal tip of the reinforcement member is configured to be positioned proximal to the septum when the connector is attached to the closed intravenous catheter system. 
     Example 245. The access system of any one of Example 178 to Example 243, wherein: 
     the closed intravenous catheter system comprises a septum spaced from the valve; 
     the reinforcement member comprises a projection that extends distally from a surface of the connector; and 
     at least a portion of the projection of the reinforcement member is configured to extend through the septum of the closed intravenous catheter system when the connector is attached to the closed intravenous catheter system. 
     Example 246. The access system of Example 245, wherein the septum comprises an opening that is in an unsealed state prior to insertion of the projection of the reinforcement member through the septum. 
     Example 247. The access system of Example 246, wherein the projection of the reinforcement member is configured to be inserted through the opening of the septum. 
     Example 248. The access system of any one of Example 245 to Example 247, wherein the projection extends distally past a distal end of the connector. 
     Example 249. The access system of any one of Example 245 to Example 247, wherein the projection is proximally recessed relative to a distal end of the connector. 
     Example 250. The access system of any one of Example 178 to Example 249, wherein, when the connector is coupled with the closed intravenous catheter system, the reinforcement member aims the cannula toward a sealable opening of the valve such that the distal tip of the cannula is advanced through the sealable opening of the valve as the cannula is moved from the retracted position to the advanced position.
 
Example 251. The access system of Example 250, wherein the sealable opening is substantially centered relative to the valve, and wherein, when the connector is coupled with the closed intravenous catheter system, the reinforcement member is substantially centered so as to be aligned with the sealable opening.
 
Example 252. The access system of any one of Example 178 to Example 251, wherein the closed intravenous catheter system further comprises a removable piercing member that extends through the valve and through the catheter tube to assist in positioning the catheter tube in the blood vessel of the patient, and wherein the piercing member is configured to be removed from the closed intravenous catheter system prior to coupling the connector of the access system with the closed intravenous catheter system.
 
Example 253. The access system of any one of Example 178 to Example 252, wherein the closed intravenous catheter system comprises an integrated side port through which fluid may be transferred to or from the catheter tube.
 
Example 254. The access system of Example 253, wherein the side port comprises an extension tube and a further connector attached to a proximal end of the extension tube.
 
Example 255. The access system of Example 254, wherein no portion of the cannula passes through the extension tube as the cannula moves between the retracted position and the advanced position.
 
Example 256. The access system of any one of Example 178 to Example 255, wherein the closed intravenous catheter system comprises a hub that defines a cavity, and wherein the valve is positioned within the cavity.
 
Example 257. The access system of Example 256, further comprising a septum positioned at a proximal end of the cavity and spaced from the valve.
 
Example 258. The access system of Example 257, wherein the septum defines a permanent opening and the valve defines a sealable opening that are aligned with a longitudinal axis that extends through the catheter tube.
 
Example 259. The access system of Example 258, wherein the closed intravenous catheter system further comprises a piercing member that extends through the openings of the septum and the valve and further extends through the catheter tube, and wherein the piercing member is configured to be removed from the catheter tube, the valve, and the septum prior to coupling of the connector with the closed intravenous line.
 
Example 260. The access system of Example 258 or Example 259, wherein a distal tip of the cannula is advanced substantially rectilinearly through the septum, the valve, and into the catheter tube as the cannula is transitioned from the retracted position toward the advanced position.
 
Example 261. The access system of any one of Example 257 to Example 260, wherein the reinforcement member extends through the septum when the connector is coupled with the closed intravenous catheter system.
 
Example 262. The access system of any one of Example 178 to Example 261, wherein the cannula comprises a first segment at a distal end thereof and a second segment that extends proximally from the first segment, wherein the second segment is stiffer than the first segment.
 
Example 263. The access system of Example 262, wherein at least a portion of the second segment extends through the valve when the cannula is in the advanced position.
 
Example 264. The access system of Example 262 or Example 263, wherein the second segment comprises a rigid tube that encompasses a flexible tube.
 
Example 265. The access system of Example 264, wherein the rigid tube is formed of a metallic material and wherein the flexible tube is formed of a polymeric material.
 
Example 266. The access system of any one of Example 178 to Example 265, further comprising the closed intravenous catheter system.
 
Example 267. A kit comprising:
 
     an access system according to any one of Example 178 to Example 266; and 
     instructions for using the kit, the instructions comprising directions to:
         couple the connector to the closed intravenous catheter system while the catheter tube of the closed intravenous catheter system is positioned in the blood vessel of the patient; and   advance the cannula from the retracted position to the advanced position.
 
Example 268. The kit of Example 267, wherein the instructions for using the kit further comprise directions to:
       

     couple a fluid transfer device to the cannula; and 
     draw blood from the blood vessel through the cannula and into the fluid transfer device. 
     Example 269. A method of using the access system of any one of Example 178 to Example 266, the method comprising: 
     coupling the connector to the closed intravenous catheter system while the catheter tube of the closed intravenous catheter system is positioned in the blood vessel of the patient; and 
     advancing the cannula from the retracted position to the advanced position. 
     Example 270. An access system comprising: 
     a connector configured to couple with an implement port of a catheter assembly that is configured to transition from an insertion configuration to an access configuration, the catheter assembly comprising:
         a hub comprising the implement port, an access port, and a cavity, the implement port being configured to permit a piercing implement to extend therethrough when the catheter assembly is in the insertion configuration;   a catheter tube coupled to the hub, the catheter tube defining a first lumen in fluid communication with the cavity, the first lumen being configured to receive at least a portion of the piercing implement therein when the catheter assembly is in the insertion configuration, the catheter tube being configured for insertion in a blood vessel of a patient;   an extension tube coupled to the access port of the hub, the extension tube defining a second lumen in fluid communication with the cavity; and   a valve coupled to the hub, the valve being configured to be in an open state when the piercing implement extends therethrough while the catheter assembly is in the insertion configuration, the valve further being configured to transition to a closed state to prevent fluid communication between the cavity and the implement port upon removal of the piercing implement from the sealing member;       

     a cannula coupled to the connector and configured to be moved relative to the connector from a retracted position to an advanced position, the cannula being sized to extend through at least a portion of the catheter tube when in the advanced position to provide access to blood within the blood vessel when the catheter tube is within the blood vessel; and 
     a reinforcement member sized to permit a portion of the cannula to be advanced therethrough as the cannula is advanced from the retracted position to the advanced position, wherein the reinforcement member satisfies one or more of the following conditions when the connector is coupled with the implement port of the catheter assembly:
         a distal tip of the reinforcement member is positioned at a proximal face of the valve without being embedded in the valve;   the distal tip of the reinforcement member is spaced proximally from the proximal face of the valve;   no portion of the reinforcement member is in contact with the valve; or   no portion of the reinforcement member extends through the valve.
 
Example 271. The access system of Example 270, wherein the cannula comprises a polymeric tube and a rigid support member that encompasses a portion of the polymeric tube, and wherein the support member is sized such that at least a portion of the support member passes through the reinforcement member as the cannula is moved to the advanced position.
 
Example 272. The access system of Example 270 or Example 271, further comprising the catheter assembly.
 
Example 273. The access system of any one of Example 270 to Example 272, wherein the catheter assembly further comprises the piercing implement.
 
Example 274. The access system of any one of Example 270 to Example 273, wherein the piercing implement comprises a needle.
 
Example 275. An access system comprising:
       

     a connector configured to couple with a catheter assembly that comprises a catheter tube configured to be positioned in a blood vessel of a patient; 
     a cannula movable relative to the connector from a retracted position to an intermediate position and from the intermediate position to an advanced position, the cannula comprising a distal tip; and 
     a reinforcement tube that encompasses at least the distal tip of the cannula and is releasably connected to the cannula so as to move in tandem with the cannula throughout movement of the cannula from the retracted position to the intermediate position, the reinforcement tube and the cannula being configured to disconnect from each other at the intermediate position to permit the cannula to advance distally through the reinforcement tube as the cannula is transitioned from the intermediate position to the advanced position. 
     Example 276. The access system of Example 275, wherein, when the connector and the catheter assembly are in a coupled state, at least the distal tip of the cannula is configured to be advanced through at least a portion of the catheter tube as the cannula is moved to the advanced position.
 
Example 277. The access system of Example 275 or Example 276, wherein the reinforcement tube becomes substantially stationary relative to the connector when the cannula passes through the intermediate position.
 
Example 278. The access system of Example 277, wherein the reinforcement tube remains substantially stationary relative to the connector as the cannula transitions from the intermediate position to the advanced position.
 
Example 279. The access system of any one of Example 275 to Example 278, further comprising an arm attached to the cannula and a catch attached to the reinforcing tube, wherein the arm engages the catch throughout movement of the cannula from the retracted position to the intermediate position and disengages from the catch as the cannula is moved distally past the intermediate position.
 
Example 280. The access system of Example 279, further comprising a sheath that comprises a first chamber defining a first diameter and a second chamber positioned distal of the first chamber and defining a second diameter larger than the first diameter,
 
     wherein the first chamber of the sheath is sized to constrain at least a distal end of the arm from flexing outwardly while positioned in the first chamber such that the arm engages the catch while in the first chamber, and 
     wherein the second chamber of the sheath is sized to permit the distal end of the arm to flex outwardly to disengage from the catch and to move distally past the catch. 
     Example 281. The access system of Example 280, wherein a proximal end of the second chamber is proximal of the intermediate position. 
     Example 282. The access system of Example 280 or Example 281, wherein the arm is outwardly biased such that the distal end of the arm automatically flexes outwardly and disengages from the catch when advanced through the second chamber of the sheath. 
     Example 283. The access system of Example 280 or Example 281, wherein the arm and the catch comprise a ramped interface that causes the distal end of the arm to flex outwardly and disengage from the catch when positioned in the second chamber of the sheath and when the reinforcing tube encounters increased resistance to distal movement as the cannula is advanced toward the advanced position.
 
Example 284. An access system comprising:
 
     a connector configured to couple with a catheter assembly that includes a catheter tube preplaced into a blood vessel of a patient; and 
     a cannula movable relative to the connector from a retracted state to a deployed state, the cannula comprising at least a distal portion that is configured to be advanced through at least a portion of the catheter tube as the cannula is transitioned from the retracted state to the advanced state, the cannula comprising:
         a first segment at a distal end of the cannula;   a second segment attached to the first segment at an interface, the first segment being relatively softer than the second segment; and   a tie layer extending over the interface and at least a portion of each of the first and second segments to attach the first and second segments together or to reinforce an attachment between the first and second segments.
 
Example 285. The access system of Example 284, wherein the second segment comprises a metal tube.
 
Example 286. The access system of Example 284 or Example 285, wherein a distal tip of the tie layer is proximally spaced from the distal tip of the cannula, and wherein the distal tip of the tie layer is configured to contact an internal surface of the catheter tube to delimit proximal movement of the cannula relative to the catheter tube.
 
Example 287. The access system of any one of Example 284 or Example 286, wherein a distal tip of the tie layer is proximally spaced from the distal tip of the cannula, and wherein the distal tip of the tie layer is configured to contact an internal surface of the catheter tube to provide tactile feedback to a user regarding a position of the cannula relative to the catheter tube.
 
Example 288. The access system of any one of Example 284 or Example 288, further comprising the catheter assembly.
 
Example 289. A method comprising:
       

     coupling an access system that comprises a reinforcement member and a movable cannula with a preplaced closed catheter system that comprises a valve and a catheter tube that is positioned within a blood vessel of a patient, said coupling comprising securing the access system to the preplaced closed catheter system such that at least one of the following conditions is satisfied:
         a distal tip of the reinforcement member is fixed at a position that is at a proximal end of the valve;   the distal tip of the reinforcement member is fixed at a position that is proximally recessed from a proximal end of the valve;   no portion of the reinforcement member is in contact with the valve; or   no portion of the reinforcement member extends through the valve; and       

     advancing the cannula of the access system from a position inside the reinforcement member through the valve of the closed catheter system and through at least a portion of the catheter tube. 
     Example 290. The method of Example 289, wherein the closed catheter system comprises a valve assembly that includes the valve and further includes a septum positioned proximal to the valve. 
     Example 291. The method of Example 290, wherein said coupling comprises advancing the distal tip of the reinforcement member of the access system through the septum before the distal tip is fixed at the position that is at or proximally recessed from a proximal end of the valve.
 
Example 292. The method of any one of Example 289 to Example 291, wherein the reinforcement member comprises a tube.
 
Example 293. The method of any one of Example 289 to Example 292, wherein said coupling is achieved without making any contact between the reinforcement member and the valve.
 
Example 294. The method of any one of Example 289 to Example 293, wherein said coupling is achieved without advancing any portion of the reinforcement member into or through the valve.
 
Example 295. The method of any one of Example 289 to Example 294, wherein the valve of the closed catheter system comprises a closable opening that is configured to permit a piercing element to extend therethrough during insertion of the catheter tube into the blood vessel of the patient, wherein the sealable region is in a self-sealed state with the piercing element having been removed therefrom during said coupling, and wherein said advancing the cannula comprises advancing the cannula through the closable opening of the valve.
 
Example 296. The method of any one of Example 289 to Example 295, wherein said advancing the cannula is achieved without advancing the distal tip of the reinforcement member distally past the proximal end of the valve.
 
Example 297. The method of any one of Example 289 to Example 296, wherein said advancing the cannula is achieved without contacting the reinforcement member to the valve.
 
Example 298. The method of any one of Example 289 to Example 297, wherein said advancing the cannula is achieved without extending the reinforcement member through any portion of the valve.
 
Example 299. The method of any one of Example 289 to Example 298, wherein the closed catheter system further comprises a hub coupled with the catheter tube at a first port of the hub, wherein an extension tube is coupled with a second port of the hub, and wherein a third port of the hub comprises the valve.
 
Example 300. The method of Example 299, wherein said coupling the access system with the preplaced closed catheter system comprises coupling a connector of the access system with the third port of the hub.
 
Example 301. The method of Example 299 or Example 300, wherein said advancing the cannula comprises advancing a distal portion of the cannula through the third port of the hub then through the first port of the hub and into the catheter tube.
 
Example 302. The method of any one of Example 299 to Example 301, wherein the hub of the preplaced closed catheter system is secured directly to the skin of the patient.
 
Example 303. The method of Example 302, wherein said coupling and said advancing are achieved without moving the hub of the preplaced catheter system relative to the skin of the patient.
 
Example 304. The method of Example 302 or Example 303, wherein the hub of the preplaced closed catheter system is positioned flat against the skin of the patient without any other element (e.g., wedge-shaped or otherwise) being present between the hub and the skin of the patient.
 
Example 305. The method of any one of Example 302 to Example 304, wherein a portion of the catheter tube is positioned within an insertion site that extends through the skin of the patient, and wherein said coupling and said advancing are achieved without contacting an external surface of one or more of the hub or the catheter tube to adjust a position of the portion of the catheter tube that extends through the insertion site.
 
Example 306. The method of any one of Example 289 to Example 305, wherein the access system further comprises an additional connector at a proximal end of the cannula, and wherein the method further comprises:
 
     coupling a fluid collection device to the additional connector; and 
     after said advancing the cannula of the access system, drawing blood through the cannula into the fluid collection device. 
     Example 307. The method of Example 306, further comprising, after said drawing blood, retracting the cannula of the access system from the catheter tube. 
     Example 308. The method of Example 307, further comprising, after said retracting the cannula, decoupling the access system from the preplaced closed catheter system. 
     Example 309. The method of Example 307 or Example 308, further comprising, after said retracting the cannula, power injecting fluid into the patient via the preplaced closed catheter system. 
     Example 310. The method of any one of Example 289 to Example 309, wherein the catheter tube of the preplaced closed catheter system is inserted into a vein of the patient at any one of a dorsal arch of a hand, a forearm, or an antecubital fossa position. 
     Example 311. An access system comprising: 
     a connector configured to couple with a catheter assembly that includes a catheter tube preplaced into a blood vessel of a patient; 
     a reinforcement tube fixedly secured to the connector; and 
     a cannula movable relative to the connector from a retracted state to a deployed state, the cannula comprising:
         a distal segment that comprises at least a portion of a flexible and/or polymeric tube; and   a medial segment that extends proximally from the distal segment, the medial segment comprising a metal tube sized to pass through the reinforcement tube,       

     wherein, when the cannula is in the retracted state, a distal tip of the medial segment is positioned within the reinforcement tube. 
     Example 312. The access system of Example 311, wherein the reinforcement tube is metallic. 
     Example 313. The access system of Example 312, wherein the reinforcement tube comprises stainless steel. 
     Example 314. The access system of any one of Example 311 to Example 313, wherein at least a portion of the metal tube of the medial segment is positioned within the reinforcement tube throughout movement of the cannula from the retracted state to the deployed state.
 
Example 315. The access system of any one of Example 311 to Example 314, wherein a portion of the metal tube of the medial segment extends distally beyond a distal tip of the reinforcement tube when the cannula is in the deployed state.
 
Example 316. The access system of any one of Example 311 to Example 315, wherein the flexible and/or polymeric tube of the distal segment comprises at least one of polyimide, polyamide, PEEK, and polyurethane.
 
Example 317. The access system of any one of Example 311 to Example 316, wherein the distal segment is configured to extend through the catheter tube such that at least a distal end of the distal segment extends distally beyond a distal tip of the catheter tube when the cannula is in the deployed state.
 
Example 318. The access system of any one of Example 311 to Example 317, wherein the metal tube of the medial segment and the flexible and/or polymeric tube of the distal segment are joined together via heat shrink tubing.
 
Example 319. The access system of any one of Example 311 to Example 317, wherein the flexible and/or polymeric tube is longer than the first segment of the cannula, wherein the distal segment comprises a first portion of the flexible and/or polymeric tube, and wherein the medial segment comprises a second portion of the flexible and/or polymeric tube that extends continuously and proximally from the first portion of the flexible and/or polymeric tube.
 
Example 320. The access system of Example 319, wherein the metal tube of the medial segment encompasses the second portion of the flexible and/or polymeric tube.
 
Example 321. The access system of Example 320, wherein the metal tube of the medial segment comprises an inner tubular surface that approximates an outer tubular surface of the second portion of the flexible and/or polymeric tube to thereby support the second portion of the flexible and/or polymeric tube.
 
Example 322. The access system of Example 320 or Example 321, wherein the metal tube of the medial segment prevents one or more of bending, buckling, or kinking of the second portion of the flexible and/or polymeric tube when the flexible and/or polymeric tube encounters proximally directed resistive forces as the cannula is advanced from the retracted state to the deployed state.
 
     Any suitable combination of the various features of the various embodiments and examples disclosed herein is contemplated. The term “coupled to” can mean connected to in any suitable fashion, whether that coupling is direct or indirect. Separate components may be coupled to each other. Moreover, in some instances, where separately identified components are integrally formed from a unitary piece of material, or stated otherwise, are included together in a monolithic element, those elements may also be said to be coupled to one another. 
     Although the foregoing detailed description contains many specifics for the purpose of illustration, a person of ordinary skill in the art will appreciate that many variations and alterations to the following details can be made and are considered to be included herein. Accordingly, the foregoing embodiments are set forth without any loss of generality to, and without imposing limitations upon, any claims set forth. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. 
     The claims following this written disclosure are hereby expressly incorporated into the present written disclosure, with each claim standing on its own as a separate embodiment. This disclosure includes all permutations of the independent claims with their dependent claims. Moreover, additional embodiments capable of derivation from the independent and dependent claims that follow are also expressly incorporated into the present written description. These additional embodiments are determined by replacing the dependency of a given dependent claim with the phrase “any one of claims [x] through the immediately preceding claim,” where the bracketed term “[x]” is replaced with the number of the most recently recited independent claim. For example, for the first claim set that begins with independent claim  1 , claim  3  can depend from either of claims  1  and  2 , with these separate dependencies yielding two distinct embodiments; claim  4  can depend from any one of claim  1 ,  2 , or  3 , with these separate dependencies yielding three distinct embodiments; claim  5  can depend from any one of claim  1 ,  2 ,  3 , or  4 , with these separate dependencies yielding four distinct embodiments; and so on. 
     Recitation in the claims of the term “first” with respect to a feature or element does not necessarily imply the existence of a second or additional such feature or element. Elements specifically recited in means-plus-function format, if any, are intended to be construed in accordance with 35 U.S.C. § 112(f). Elements not presented in requisite means-plus-function format are not intended to be construed in accordance with 35 U.S.C. § 112(f). Embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows.