Patent Publication Number: US-2020276431-A1

Title: Luer-activated valves

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of application Ser. No. 16/289,223, filed Feb. 28, 2019. 
    
    
     FIELD 
     The present invention relates to an apparatus, system and method for selectively blocking the fluid path or infusion stream of a medical device, particularly related to flushable intravenous (IV) catheters, sheath introducers, tear-away sheaths or in-line intravenous infusion valves and connectors. 
     BACKGROUND 
     Catheters are universally used to administer fluid, medicine or parenteral nutrients, withdraw blood, aspirate an embolism, or monitor a patient in need of medical attention. An over-the-needle catheter is used to access a blood vessel, the needle is withdrawn and IV tubing is coupled to the proximal end catheter hub via a luer-lock connector. As the needle is removed from the catheter, the clinician simultaneously places a digital pressure on the catheter tube in the vessel to constrict the fluid path to stop blood leaking from the catheter hub into the workplace, and in doing so, reduces the probability of a blood exposure to the clinician. If the clinician fails to constrict the fluid path, blood is free to flow from the patient and out of the sheath, creating a potential blood exposure for the clinician. 
     Introducer sheaths and tear-away sheaths are widely used to facilitate vascular or bodily access into a patient. The core or obturator of the introducer sheath or tear-away sheath is withdrawn leaving the distal portion of the sheath positioned in the patient and the proximal end of the sheath outside the patient. Some tear-away sheaths include duck-bill valves in an attempt to limit blood loss. However, blood typically leaks through the sheath. 
     Fluids administered to a patient through an IV catheter are delivered through a series of tubes, connectors and valves. In-line infusion, or needleless valves and connectors are classified in use as: split septum (creates negative displacement); capped luer (creates negative displacement); mechanical valve (creates negative displacement); and surface septum (creates positive displacement). Negative or positive endolumenal displacement in the fluid path is well known in the medical literature to cause catheter occlusion via blood reflux. 
     A number of safety IV catheters now include a luer-activated valve comprising a longitudinally movable piston, co-operable resilient duck-bill or split septum membrane positioned orthogonally to the piston axis, requiring these split septum flaps to be stored in a stressed or deformed state the entire time the needle resides in the catheter hub. This means the flaps are deformed from the time components are assembled until the device is used. Resilient material takes a “set” when it is positioned in a configuration that differs from its original formed configuration. With an extended shelf life of up to 5 years, the material integrity of the split septum flaps degrades and fatigues significantly, and performs poorly and leaks when the needle is finally removed after the IV catheter is advanced into the patient. The movement of the piston also displaces fluid in the fluid path, creating positive endolumenal pressure when the piston moves distally, and creating a negative endolumenal pressure when the piston moves proximally, increasing the probability of catheter occlusion. These split septum/piston valves also require the catheter hub dimensions to be increased, both outside diameter and length, adding mass to the device, adding bulk to the packaging and medical waste stream, and altering the clinician&#39;s proprioception associated with IV catheter placement. 
     SUMMARY 
     According to one implementation a luer-activated valve is provided that allows the clinician to selectively occlude or close, or open the fluid path of a flushable IV catheter, sheath introducer, tear-away sheath or in-line infusion connector valve multiple times without creating a positive or negative displacement within the fluid path of the device. 
     According to some implementations a luer-activated valve of unitary construction (i.e. made from a single piece of material) is provided. According to some implementations a luer-activated valve is provided that includes a deformable, resilient elongate member having a through passage or fluid path that can be selectively opened with the use of a luer fitting and transitions to a closed position to occlude blood flow through the valve by removing the needle or luer fitting from the valve. According to some implementations the luer-activated valve is a displacement-neutral valve and is stored in a non-stressed or relaxed state, automatically blocking the fluid path when the needle is removed from an IV catheter hub, selectively opens when a male luer connector is inserted into the catheter hub, selectively closes when the luer connector is removed, and functions multiple times when a male luer connector is inserted or removed from the catheter hub. 
     According to some implementations the luer-activated valve reduces assembly cycle time and simplifies the assembly process and insures the tip of the needle remains sharp because it is not touched or damaged during assembly. 
     According to one implementation the valve includes a clamping member that is triggered by an actuator when a needle or luer hub is positioned within the catheter hub. In a first position, the clamping member is retained on a distal wall portion of the actuator and does not contact the exterior wall of the through passage of resilient member of the luer-activated valve. The second position is created when the needle and needle hub are inserted in the IV catheter hub, engaging the moveable ferrule or actuator to release the clamping member from a first retained position, to a second ready-to-use position where a compressive radial force is placed on the resilient elongate tube of the luer-activated valve. When the needle is removed from the catheter hub, the clamping arms or segments move to a third position, squeezing the elongate tube and closing the fluid path. The compressive force of the clamping arms or segments is selectively releasable when the distal end of a luer connector engages the clamping arms and opens the luer-activated valve. 
     According to other implementations, a luer-activated valve is provided that includes a clamp co-operable with a resilient elongate member. According to some implementations, a luer-activated valve is provided that includes a resilient member, a clamp and an actuator. According to some implementations, a valve is provided that comprises a metal clip with opposing arms co-operable with a male luer connector to open or close the fluid path of a resilient elongate member. According to some implementations, a luer-activated valve is provided that comprises a sub-assembly having an open, un-restricted through passage. According to some implementations, a valve is provided that comprises a base, a mid-section valve and opposing arms co-operable with a male luer connector to selectively open or close the fluid path of the valve. 
     These and other implementations along with their advantages and features will become evident in view of the drawings and the detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a cross-sectional side view of a ready-to-use IV catheter according to one implementation having a luer-activated valve in a first position with the needle of the IV catheter passing through the luer-activated valve. 
         FIG. 2A  shows a cross-sectional side view of the luer-activated valve of  FIG. 1  in a second position with the needle removed, having an obstructed, clamped or closed fluid path. 
         FIG. 2B  shows a rear view of the luer-activated valve shown in  FIG. 2A  along axis AA. 
         FIG. 3A  shows a cross-sectional side view of the luer-activated valve of  FIG. 1  in a third position having an unobstructed, or open fluid path when a luer-tipped connector is placed within the IV catheter hub. 
         FIG. 3B  is an isometric, cross-sectional view of the luer-activated valve of shown in  FIG. 3 . 
         FIG. 4A  is a cross-sectional stand-alone side view of the luer-activated valve in a first open position. 
         FIG. 4B  is a cross-sectional side view of the luer-activated valve in a closed position. 
         FIG. 4C  is a cross-sectional stand-alone side view of the luer-activated valve in a second open position. 
         FIG. 5A  shows a cross-sectional side view of a ready-to-use IV catheter having a luer-activated valve in a first, retained position with a spring clip placing a compressive, clamping force on a resilient elongate tube that is in fluid communication with the catheter tube. 
         FIG. 5B  shows a rear view of the luer-activated valve shown in  FIG. 5A  in the IV catheter in axis BB in a first, retained position with the needle passing through the luer-activated valve. 
         FIG. 5C  is a side cross-sectional view of a luer activated valve located inside an IV catheter, the luer activated valve acting on a tubular projection of a valve plug. 
         FIG. 6A  shows a cross-sectional side view of the luer-activated valve of  FIG. 5A  in a closed position with the needle removed, having an obstructed, clamped or closed fluid path. 
         FIG. 6B  shows a rear view of the luer-activated valve shown in  FIG. 6A  in the IV catheter in axis CC in the closed position. 
         FIG. 6C  is a side cross-sectional view of a luer activated valve located inside an IV catheter, the luer activated valve acting on a tubular projection of a valve plug to effectuate a closing an internal through lumen located inside the tubular projection. 
         FIG. 7  shows a cross-sectional side view of a luer-activated valve in a second open position having an unobstructed or open fluid path when a luer fitting is placed within the IV catheter hub. 
         FIG. 8  shows an isometric, cross-sectional view of a luer-activated valve of  FIG. 7  having an open fluid path. 
         FIG. 9A  is a stand-alone cross-sectional side view of the spring clip in an open position. 
         FIG. 9B  is a stand-alone cross-sectional side view of the spring clip in a closed position. 
         FIG. 10A  shows a cross-sectional view of a proximal portion of the resilient elongate tube. 
         FIG. 10B  shows a cross-sectional view of the distal end portion of the catheter tube. 
         FIG. 11  shows an exploded isometric view of an IV catheter without a needle according to another implementation. 
         FIG. 12  is a cross-sectional side view of a valve plug according to another implementation. 
         FIG. 13A  is a cross-sectional side view of a valve clamp in a non-radially expanded state according to one implementation. 
         FIG. 13B  is a cross-sectional side view of the valve clamp in a radially expanded state according to one implementation. 
         FIG. 14A  shows a side view of a valve actuator according to one implementation. 
         FIG. 14B  is a cross-sectional side view of the valve actuator of  14 A. 
         FIG. 14C  is a proximal end view of the actuator shown in  FIGS. 14A and 14B . 
         FIG. 14D  is an isometric view of the valve actuator of  FIGS. 14A and 14B . 
         FIG. 14E  is a side view of an actuator according to another implementation. 
         FIG. 15A  shows a cross-sectional side view of a luer-activated valve having an axial through-hole with a clamping device in a first, retained position within an IV catheter hub before a needle is coaxially introduced into the IV catheter. 
         FIG. 15B  shows a cross-sectional side view of the luer-activated valve of  FIG. 15A  having an annular rigid plate disposed between the clamp member and the proximal facing wall of the valve plug. 
         FIG. 16  shows a cross-sectional side view of a needle coaxially located in the luer-activated valve of  FIG. 15A  in a second, retained position placing a clamping force on a resilient elongate tube through which a needle passes. 
         FIG. 17  shows a side view of the luer-activated valve shown in  FIG. 15A  in a third position (i.e. closed position) having a closed fluid path. 
         FIG. 18  shows a side view of the luer-activated valve shown in  FIG. 15A  in a fourth position having an unobstructed fluid path when a luer connector is placed within the IV catheter hub. 
         FIG. 19A  shows a side view of a valve actuator according to another implementation. 
         FIG. 19B  is a cross-sectional side view of the valve actuator of  19 A. 
         FIG. 19C  is a proximal end view of the actuator shown in  FIGS. 19A and 19B . 
         FIGS. 20 and 21  show an IV catheter in different operational states that incorporate the actuator of  FIGS. 19A-C . 
         FIG. 22A  shows a side view of a valve actuator according to another implementation. 
         FIG. 22B  is a cross-sectional side view of the valve actuator of  22 A. 
         FIG. 23  is a cross-sectional side view of an IV catheter having incorporated therein the valve actuator of  FIGS. 22A and 22B . 
         FIG. 24A  shows a cross-sectional side view of an IV catheter having a luer-activated valve having an axial through-hole with a spring member in a first, retained position within an IV catheter hub before a needle is coaxially introduced into the IV catheter. 
         FIG. 24B  shows a cross-sectional side view of the luer-activated valve of  FIG. 24A  having an annular rigid plate disposed between the distal end of the spring member and the proximal facing wall of the valve plug. 
         FIG. 25  shows a cross-sectional side view of a needle coaxially located in the luer-activated valve of  FIG. 24A  in a second, retained position with the distal end segments of the spring member placing clamping forces on a resilient elongate tube through which a needle passes. 
         FIG. 26  shows a side view of the luer-activated valve shown in  FIG. 24A  in a third position (i.e. closed position) having a closed fluid path. 
         FIG. 27  shows a side view of the luer-activated valve of  FIG. 24  in a fourth position having an unobstructed fluid path when a luer tipped connector is placed within the IV catheter hub. 
         FIG. 28  is a cross-sectional side view of the IV catheter of  FIG. 24A  having incorporated therein the valve actuator of  FIGS. 22A and 22B . 
         FIGS. 29A-C  show alternative views of the spring member and valve plug with the valve in the closed position as depicted in  FIG. 26 . 
         FIGS. 30A and 30B  are cross-sectional side views of an IV catheter similar to that of  FIG. 25  having incorporated therein a needle guard. 
         FIGS. 31A and 31B  are cross-section side views of an IV catheter having incorporated therein a spring clip needle guard. 
         FIGS. 32A-G  illustrate a method of loading a valve assembly into the hub of an IV catheter with the use of a mandrel. 
     
    
    
     DETAILED DESCRIPTION 
     A number of luer-activated valves are disclosed herein. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be obvious to one of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known structures and processing steps have not been shown in particular detail in order to avoid unnecessarily obscuring the present invention. Additionally, it should be noted that the invention is applicable to a variety of hypodermic devices and infusion devices such as IV catheters, sheath introducers, tear-away sheaths or in-line infusion valves. It is appreciated, however, that the present invention is not limited to these devices. 
     It is understood that the luer-activated valves disclosed herein in regard to IV catheters can easily be adapted to all types of other devices where a needle or guidewire may be used, including, but not limited to, sheath introducers, tear-away sheaths, or in-line infusion valves and connectors. The luer-activated valves disclosed herein in use with an IV catheter can also be easily adapted to an endovascular needle, or other needles used in invasive procedures. 
       FIG. 1  illustrates a cross-sectional side view of a ready-to-use over-the-needle, flushable IV catheter  10  having luer-activated valve  20  in a first retained position with a hollow bore needle  30  extending through the luer-activated valve. According to some implementations the needle  30  includes an inner lumen  32  and a distal sharpened, beveled tip  34 . A proximal end portion  36  of needle  30  is attached to a needle hub  38 . According to one implementation the needle hub  38  includes a gas-permeable portion  39  for venting air as blood fills the catheter hub  11 . The catheter hub  11  includes a flashback chamber  12  and has at its proximal end a proximal luer flange  13  for attaching a luer-lock fitting. The catheter  10  includes a polymeric hollow catheter tube  14  that, according to one implementation, is press fit in the distal end of hub  11  over ferrule  16 . According to one implementation the proximal luer flange  13  is configured to facilitate an attachment of a male luer fitting  40  to the catheter hub  11  as shown in  FIGS. 3A and 3B . 
     The luer-activated valve  20  is located inside the catheter hub  11  and includes a proximal flange portion  21 , a distal flange portion  22  and a tubular portion  23  a tubular part extending between the proximal and distal flanges. The valve  20  is configured to assume an open position as shown in  FIGS. 1, 3A and 3B  and a closed position as shown in  FIGS. 2A and 2B . According to one implementation the valve  20  is made of a resilient polymeric material and constructed such that the valve is continuously urged toward the closed position. 
     In use, valve  20  has first and second open positions. The first open position is shown in  FIG. 1  wherein the inner walls of the tubular portion of the valve  20  are pressed outward as a result of the needle  30  passing therethrough. When the needle  30  is removed from the IV catheter  10 , the valve  20  automatically transitions to the closed position as shown in  FIGS. 2A and 2B  due to the resilient nature of the tubular portion  23 . In the closed position a part of the tubular portion  23  of the valve  20  is caused to close on itself as shown in  FIG. 2A . According to one implementation, the outer diameter of the needle  30  and the inner diameter of the tubular portion  23  of the valve  20  are dimensioned to cause the inner walls  80  and  81  (see  FIG. 4A ) of the tubular portion  23  of the valve to press against the outer surface of the needle  30  to prevent the passage of blood between them.  FIGS. 4A and 4C  are enlarged cross-section views of the valve  20  respectively shown in the first and second open positions.  FIG. 4B  is an enlarged cross-section view of the valve  20  shown in the closed position. 
     When valve  20  is in the closed position it is capable of assuming the second open position as shown in  FIGS. 3A and 3B  upon there being a distally applied force to a proximal face  21   a  of the proximal flange  21 , the valve transitions from the closed position to the second open position and subsequently returns to the closed position when the distally applied force is removed. In the second open position fluid flow is permitted through an opening  25  that extends through the proximal and distal flanges and the tubular part. When valve  20  is in the closed position fluid flow is impeded by a closing of the opening  25 . 
     The valve  20  is in a rest position when the valve assumes the closed position. According to one implementation the proximal flange  21  includes first and second wing portions  21   b  and  21   c . According to one implementation one or both of the wing portions  21   b  and  21   c  is positioned at an angle α 1  with respect to the valve&#39;s longitudinal axis  75  when the valve  20  in the first open position as shown in  FIG. 4A  and an angle α 2  when the valve is in the closed position as shown in  FIG. 4B , the angle α 1  being greater than α 2 . When the valve  20  is in the second open position one or both of the wing portions  21   b  and  21   c  is positioned at an angle α 3  with respect to the longitudinal axis  75  of the valve  20  as shown in  FIG. 4C  with angle α 3  being greater than α 2 . According to one implementation α 3  is also greater than α 1 . When the valve  20  is in either the first or second open position, the change in angular orientation of the wing portions  21   b  and  21   c  occurs automatically due to the resilient nature of the valve. 
     According to one implementation, valve  20  is positioned at the distal end of the catheter hub  11  such that the distal face  22   a  of the distal flange  22  faces the inner distal wall  15  of the catheter hub. In the implementation shown in  FIGS. 1-3B  the distal face of the distal flange  22  abuts a portion of the ferrule  16  located inside the catheter hub, the ferrule being interposed between distal face of the flange and the inner distal wall of the catheter hub  11 . According to one implementation the distal flange  22  of valve  20  is held in the distal end portion of the catheter hub  11  by a rigid annular lip  5  protruding radially inward from an inner wall of the catheter hub. When valve  20  is initially introduced into the catheter hub  11 , the distal flange  22  is endowed with sufficient flexibility to allow it to deform sufficiently to pass across the annular lip  5 . When the distal flange  22  has passed across the annular lip  5  it then, by its resilient nature, returns towards its initial unstressed state and works in conjunction with the annular lip  5  to hold the valve in place inside the catheter hub  11  without the need to use an adhesive. According to one implementation, after placement of the valve  20  inside the catheter hub  11 , the distal flange  22  and annular lip  5  further function together to form an annular leak tight seal between them. 
     According to one implementation the valve  20  is molded part of a unitary construction. That is, it is made of a single piece of material. One or both of the proximal and distal flanges  21  and  22  may be formed or treated in any of a number of ways to provide them with a higher rigidity than that of the tubular portion  23 . This has several advantages. By enhancing the rigidity of the distal flange  22  it can be more securely fixed inside the catheter hub  11  making it more difficult to proximally move the distal flange across the annular lip  5  inside the catheter hub. By enhancing the rigidity of the proximal flange  21 , it can safeguard against a folding of the flange on itself to ensure a sufficient amount of force is capable of being applied to the proximal flange by the male luer connector to cause the opening of the tubular portion  23  of the valve when the distally applied force is applied to the proximal flange. 
       FIG. 1  illustrates the IV catheter  10  in a ready-to-use state with the needle hub  38  attached to the proximal end of the catheter hub  11  and the introducer needle  30  passing through the through opening  25  of valve  20  and through the catheter tube  14 . The sharpened distal tip  34  of the needle  30  extends beyond the distal end of the catheter tube  14 . 
     After the catheter tube  14  has been properly placed inside a vein or another part of the patient, the needle  30  is withdrawn by decoupling the needle hub  38  from the catheter hub  11  and withdrawing the needle from the device so that thereafter the assembly of  FIG. 2A  is produced. As discussed above, as the needle  30  is withdrawn from the through opening  25  of the valve  20 , the valve transitions from the first open position as shown in  FIG. 1  to the closed position as shown in  FIGS. 2A and 2B . Thereafter, fluids may be withdrawn from or administered to the patient through the indwelling catheter tube  14 . According to one implementation this is accomplished by introducing a male luer fitting  40  into the catheter hub  11  as shown in  FIGS. 3 and 4 . The male luer connector  40  includes a part  41  (e.g. threads) that cooperates with the proximal luer flange  13  of the catheter hub to secure the luer connector to the catheter hub. The luer fitting  40  also includes an internal through lumen  42  that is placed into fluid communication with the catheter tube  14  through the valve  20  when the valve has transitioned from the closed position to the second open position. 
     As the male luer fitting  40  is introduced into the catheter hub  11 , its distal end surface  43  makes contact with the wings  21   b  and  21   c  of the proximal flange  21  to cause the wings  21   b  and  21   c  to flex distally from the first angular position α 2  with respect to the longitudinal axis  75  to a second angular position α 3  with respect to the longitudinal axis  75  as discussed above. The valve  20  is constructed such that as the wings  21   b  and  21   c  are forced toward and to the second angular position by the distally applied force applied to them by the distal end surface  43  of the luer connector  40 , a through passage  25  is established through the valve  20  to place the catheter tube  14  and the inner lumen  42  of the luer connector  40  in fluid communication. When the luer fitting  40  is subsequently removed from the catheter hub  11 , the assembly of  FIG. 2A  is automatically reestablished with the valve  20  reassuming the closed position. According to some implementations the outer diameter of the male luer fitting  40  and the inner diameter of the catheter hub  11  are dimensioned such that when the fitting  40  is positioned inside the catheter hub to cause an opening of the valve  20 , a fluid seal is established between the outer circumferential surface of the fitting  40  and the inner wall of the catheter hub. 
     According to one implementation valve  20  is positioned at a distal end section of the catheter hub  11  without freedom of rotation. This can be achieved by establishing a press-fit relationship between the outer circumferential surface of the distal flange  22  and the inner wall of the catheter hub  11 . One or more projections extending radially inward from the inner wall of the catheter hub  11  and acting on the distal flange  22  of the valve  20  may alternatively be provided to inhibit or prevent rotation of the valve  20  during the male luer  40  being advance into or out of the catheter hub  11 . The distal face  22   a  of the distal flange  22  of valve  20  may additionally or alternatively be roughened. 
     As discussed above,  FIGS. 2A and 2B  illustrate the valve  20  in the closed position. To assist in facilitating a separating and bringing together of the inner walls of the tubular portion  23  of the valve, the proximal flange  21  may be provided with first and second slits  51   a  and  51   b  that each extend partially radially inward form an outer circumference of the proximal flange. 
       FIGS. 5A-10B  illustrate other implementations of a luer-activated valve  120 . In the examples of  FIGS. 5A-8  the valve  120  is shown being a part of an IV catheter  100 . 
       FIG. 5A  illustrates a cross-sectional side view of a ready-to-use over-the-needle, flushable IV catheter  100  having luer-activated valve  120  in a first retained position with a hollow bore needle  130  extending through the luer-activated valve. According to some implementations the needle  130  includes an inner lumen  132  and a distal sharpened, beveled tip  134 . A proximal end portion  136  of needle  30  is attached to a needle hub  138 . According to one implementation the needle hub  138  includes a gas-permeable portion  139  for venting air as blood fills the catheter hub  111 . The catheter hub  111  includes an inner cavity  18  terminating at a proximal luer flange  113 . The catheter  100  includes a hollow catheter tube  114  that has a proximal portion  114   a  residing inside the catheter hub  111  and a distal portion  114   b  that resides distal to the catheter hub. A segment  114   c  of the catheter tube  114  is fixed to the catheter hub  111  in a leak-tight manner. The distal-most end of the catheter hub  111  may include an elongate conduit  150  inside which the catheter tube segment  114   c  resides and is fixed. According to one implementation the proximal luer flange  113  is configured to facilitate an attachment of a male luer fitting  140  as shown in  FIG. 7 . 
     The luer-activated valve  120  is located inside the catheter hub  111  and comprises a spring clip  121  and the proximal portion  114   a  of the catheter tube  114 . The valve  120  is configured to assume a first open position as shown in  FIGS. 5A and 5B , a second open position as shown in  FIGS. 7 and 8 , and a closed position as shown in  FIGS. 6A and 6B . According to one implementation the spring clip  121  is made of a metal (e.g. stainless steel) and the proximal portion  114   a  of the catheter tube is made of a resilient polymeric material. The proximal portion  114   a  is constructed such that it has an ability to be pinched closed by the spring clip  121  as shown in  FIGS. 6A and 6B  and is thereafter able to automatically assume an open position as shown in  FIGS. 7 and 8  when the spring clip  121  seizes to pinch the proximal portion  114   a.    
       FIG. 9A  shows an enlarged cross-section view of the spring clip  121  in the second open position.  FIG. 9B  shows an enlarged cross-section view of the spring clip  121  in the closed position. 
     The spring clip  121  includes a base  122  having a through opening  123  through which a section of the proximal portion  114   a  of the catheter tube passes. The spring clip  121  includes first and second arms  124  and  125  that are positioned about the outer surface  116  of the proximal portion  114   a  of the catheter tube. Each of the first and second arms  124  and  125  respectively includes a first section  126  and  127  having a distal end  126   a  and  127   a  and a proximal end  126   b  and  127   b . The distal end  126   a  of the first section  126  of arm  124  is coupled to the base  122  with the proximal end  126   b  of the first section  126  being disposed radially inward of the distal end  126   a  of the first section  126  with respect to the longitudinal axis  175 . In a similar manner, the distal end  127   a  of the first section  127  of arm  125  is coupled to the base  122  with the proximal end  127   b  of the first section  127  being disposed radially inward of the distal end  127   a  of the first section with respect to the longitudinal axis  175 . 
     Each of the first and second arms  124  and  125  respectively includes a second section  128  and  129  located proximally to first sections  126  and  127 . The second section  128  of the first arm  124  has a distal end  128   a  and a proximal end  128   b  with the distal end  128   a  being coupled to the proximal end  126   b  of the first section  126  of the first arm  124  to form a first pinching site  160 . The proximal end  128   b  of the second section  128  is disposed radially outward of the distal end  128   a  of second section  128  with respect to the longitudinal axis  175 . The second section  129  of the second arm  125  has a distal end  129   a  and a proximal end  129   b  with the distal end  129   a  being coupled to the proximal end  127   b  of the first section  127  of the second arm  125  to form a second pinching site  161 . The proximal end  129   b  of the second section  129  is disposed radially outward of the distal end  129   a  of second section  128  with respect to the longitudinal axis  175 . 
     Each of the first and second arms  124  and  125  is made of a resilient material and constructed such that the first and second pinching sites  160  and  161  are continuously urged radially inward toward one another to position the valve in the closed position. In the closed position of the valve  120 , the first and second pinching sites  160  and  161  press against opposite sides of the outer surface  116  of the proximal portion  114   a  of the catheter tube  114  with a force sufficient to cause the tubular wall of the proximal portion  114   a  to collapse as shown in  FIGS. 6A and 6B  to cause a full or substantially full closing of the inner lumen  118  of the proximal tube portion  114   a.    
     In the second open position of the valve  120 , as shown in  FIGS. 7 and 8 , the first and second pinching sites  160  and  161  are positioned radially apart from one another so as not to press against the outer surface of the proximal portion of the catheter tube  114   a  to permit an opening of the inner lumen  118  of the proximal catheter tube portion  114   a . As discussed above, the proximal portion  114   a  of the catheter tube is made of a resilient material that allows the inner lumen to automatically expand from the closed position as shown in  FIG. 6A  to a full or partial open position as shown in  FIGS. 7 and 8 . 
       FIGS. 5A and 5B  show the valve  120  in the first open position when the IV catheter  100  is in a ready-to-use state with the introducer needle  130  residing inside the catheter tube  114  with its distal sharpened tip  134  extending distally to the distal-most end of the catheter tube. According to one implementation, in the first open position of valve  120  the first and second pinching sites  160  and  161  press against the outer surface  116  of proximal portion  114   a  of the catheter tube  114  while the inner lumen  118  of the proximal portion  114   a  of the catheter tube is maintained open by a passing of the introducer needle  130  through the inner lumen  118 . That is, the outer circumferential surface of the needle shaft acts on the inner luminal wall of the proximal catheter portion  114   a  to maintain the inner lumen  118  open. 
     According to one implementation, the outer diameter of the needle  130  and the inner diameter of the proximal portion  114   a  of the catheter tube  114  are dimensioned to cause the inner walls of the proximal portion  114   a  to press against the outer surface of the needle  30  to prevent the passage of blood between them. 
     When the needle  130  is removed from the IV catheter  100 , the valve  120  automatically transitions to the closed position as shown in  FIGS. 6A and 6B  due to the resilient nature of the spring clip arms  124  and  125 . 
     When valve  120  is in the closed position as shown in  FIGS. 6A and 6B , it is capable of assuming the second open position, as shown in  FIGS. 7 and 8 , upon there being a distally applied force F to the second sections  128  and  129  of the first and second arms  124  and  125  of spring clip  121 . When the distally applied force F is subsequently removed, the valve  120  automatically returns to the closed position. 
     According to one implementation, one or both of the first and second sections  128  and  129  of arms  124  and  125  is position at an angle β 1  with respect to the longitudinal axis  175  of the clip when the valve  120  is in at least one of the first and second open positions. When the valve is in the closed position one or both of the first and second sections  128  and  129  of arms  124  and  125  is positioned at an angle β 2  with respect to the longitudinal axis  175  of the spring clip  121  as shown in  FIG. 9B , the angle β 1  being greater than the angle β 2 . 
     According to one implementation, spring clip  121  is positioned at the distal end of the catheter hub  111  such that the distal face  122   a  of the spring clip base  122  faces the distal inner wall  115  of the catheter hub  111 . According to one implementation the base  122  is held tight or fixed to the base  115  of the catheter hub  111  without freedom of rotation. 
     According to one implementation the spring clip  121  is unitarily constructed. That is, it is made of a single piece of material. 
     As explained above,  FIG. 5A  illustrates the IV catheter  100  in a ready-to-use state with the needle hub  138  attached to the proximal end of the catheter hub  111  and the introducer needle  130  passing though the valve  120  and catheter tube  114 . 
     After the catheter tube  114  has been properly placed inside a vein or another part of the patient, the needle  130  is withdrawn by decoupling the needle hub  138  from the catheter hub  111  and withdrawing the needle from the device so that thereafter the assembly of  FIG. 6A  is produced. As discussed above, as the needle  130  is withdrawn, the valve  120  transitions from the first open position as shown in  FIGS. 5A and 5B  to the closed position as shown in  FIGS. 6A and 6B . Thereafter, fluids may be withdrawn from or administered to the patient through the indwelling catheter tube  114  located inside the patient. According to one implementation this is accomplished by introducing a male luer fitting  140  into the catheter hub  111  as shown in  FIGS. 7 and 8 . The male luer fitting  140  includes a part  141  (e.g. threads) that cooperates with the proximal luer flange  113  of the catheter hub  111  to secure the luer connector to the catheter hub. The luer connector  140  also includes an internal through lumen  142  that is placed into fluid communication with the catheter tube  114  through the valve  120  when the valve has transitioned from the closed position to the second open position. In the implementation of  FIGS. 5A-8 , the valve  120  is comprised of the spring clip  121  and the proximal portion  114   a  of the catheter tube  114  on which the spring clip acts. 
     As the male luer fitting  140  is introduced into the cavity of the catheter hub  111 , its distal end surface  143  makes contact with the second sections  128  and  129  of the arms  124  and  125  of spring clip  121  to cause the second sections  128  and  129  to flex distally from angular position β 2  with respect to angular position β 1 . The spring clip is constructed such that as the second sections  128  and  129  of arms  124  and  125  are forced to angular position β 1  by the distally applied force applied to them by the distal end surface  143  of the luer connector  140 , the first and second pinching sites  160  and  161  move radially away from one another to enable the proximal portion  114   a  of the catheter tube  114  to automatically open to place the catheter tube  114  and the inner lumen  142  of the luer connector  140  in fluid communication. When the luer connector  140  is subsequently removed from the catheter hub  111 , the assembly of  FIG. 6A  is automatically reestablished with the valve  120  assuming the closed position. 
     As shown in  FIG. 7 , according to one implementation the luer-activated valve  120  further includes a resilient O-ring  170  positioned about the first and second pinching sites  160  and  161 . The resilient O-ring  170  is dimensioned and positioned on the spring clip  121  in the region of the first and second pinching sites  160  and  161  in a manner that results in a continuous compressive force being applied to the arms  124  and  125  of the spring clip  121  by the O-ring to assist in urging the valve  120  continuously toward the closed position. 
     As shown in  FIGS. 10A and 10B , according to one implementation the proximal portion  114   a  of the catheter tube  114  has a wall thickness t 1  that is less than the wall thickness t 2  of the distal portion  114   b . The reduced wall thickness in the proximal portion  114   a  causes it to be more easily compressed by the spring clip  121 . According to other implementations the tubular walls of the proximal portion  114   a  are made to have a Shore hardness that is less than the Shore hardness of the tubular walls of the distal portion  114   b  of the catheter tube  114 . 
     In the implementations of  FIGS. 5A-10B  the tubular portion  114   a  of valve  120  forms a single part with the remaining part of the catheter tube  114 . According to other implementations the tubular portion  114   a  is not a part of the catheter tube  114 , yet is coupled to the catheter tube in a way that places them in fluid communication with one another. 
     As shown in  FIGS. 5C and 6C , according to some implementations the proximal end of the catheter tube  114  does not extend into the inner cavity of the catheter hub  111 , but is instead coupled to a distal end of the catheter hub. In the implementations of  FIGS. 5C and 6C  a valve plug  180  is positioned at the internal distal end of the catheter hub  111 . The valve plug  180  includes a through opening  184  and is arranged in the catheter hub  111  to substantially place the through opening  184  in axial alignment with a proximal end of the catheter tube. The valve plug includes a base  186  having a proximal facing surface  181  and a distal facing surface  182 . Extending proximally from the base is a tubular projection  183 . According to some implementations a recess is provided in the proximally facing surface  181  in which resides the base  122  of the spring clip  121 . In  FIG. 5C  the valve clip  121  is arranged as shown in  FIG. 9A  so that the first and second pinching sites  160  and  161  press against the outer wall of the tubular projection  183 , the through opening  184  of the plug  180  being maintained in an open state as a result of the needle  130  passing therethrough. In  FIG. 6C  the valve clip  121  is arranged as shown in  FIG. 9B  with the needle  130  having been removed from the IV catheter. With the needle  130  removed from the IV catheter the first and second pinching sites of the valve clip  121  automatically move radially inward towards one another to cause at least a portion of the through opening extending through the tubular projection  183  to close. 
     According to some implementations the valve plug  180  is disposed inside the catheter hub  111  in a manner that prevents its rotation therein. According to some implementations the valve clip  121  is supported on or in a recess of the valve plug  180  in a manner that prevents or resists its rotation thereon or therein. 
       FIG. 11A  is an isometric exploded view of an IV catheter  200  without the introducer needle according to another implementation. The IV catheter includes a catheter hub  202  having an internal cavity  204  that is in fluid communication with an elongate polymeric catheter tube  206  that extends distally from a base  207  of the catheter hub. As will be discussed in more detail below, according to one implementation the proximal end portion of the catheter tube  206  is secured to the catheter hub  202  by use of a ferrule  208  on which the proximal end of the catheter tube is press-fit. 
     The catheter hub  202  has at its proximal end a proximal luer flange  210  for attaching a luer-lock fitting. According to one implementation the proximal luer flange  210  is configured to facilitate an attachment of a male luer fitting to the catheter hub  202  is a manner like that shown in  FIGS. 3A, 7 and 18 . 
     The IV catheter  200  has a longitudinal axis  201  and includes a valve assembly  220  that comprises a valve plug  230 , a valve clamp  240 , a restraining element  250 , a spring  260  and a valve actuator  270 . In use, the valve assembly components function together to regulate the opening and closing of a valve element to respectively permit or prevent the passage of fluids therethrough. To this end, according to one implementation, the valve assembly  220  is transitional from a first open position to a closed position, and is thereafter transitional between the closed position and a second open position. 
       FIG. 12  illustrates a cross-sectional side view of the valve plug  230  according to one implementation. The valve plug  230  includes a base  231  having proximal facing wall  232  and a distal facing wall  233 . The proximal facing wall  232  includes a ring-shaped recess or annularly configured cavity  234  that circumferentially surrounds tubular projection  235  that extends proximally from the base  231 . According to one implementation the tubular projection  235  is circular, and together with the base  231  includes a passage  236  that extends through the valve plug  230 . The tubular projection  235  includes opposing outer walls  237   a  and  237   b , and opposing inner walls  238   a  and  238   b.    
     According to one implementation at least the tubular projection  235  is made of an elastomer that enables the opposing outer walls  237   a  and  237   b  to be radially pressed toward one another to cause the opposing inner walls  238   a  and  238   b  to come together in a manner that closes passage  236 . The tubular projection  235  is configured such that when the outer walls  237   a  and  237   b  are not being pressed upon, the passage  236  resumes a full or partial open configuration. According to one implementation the entirety of the plug  230  is made of an elastomer. 
     According to one implementation the tubular projection  235  is made of a first material and the remainder of the plug is made of a second material that has a durometer greater than that of the first material. According to another implementation the tubular projection  235  and plug base  231  are two separate pieces that can be bonded together. 
     According to one implementation the plug  230  is unitarily formed (i.e. made of a single piece) by, for example, a molding process. 
       FIGS. 13A and 13B  shows a cross-sectional side view of the valve clamp  240  according to one implementation. According to one implementation the clamp  240  is made of an elastomer and includes first and second opposing arms  241   a  and  241   b . Each of arms  241   a  and  241   b  respectively includes an inner clamping surface  242   a  and  242   b . According to one implementation the outer contour of each of arms  241   a  and  241   b  respectively includes an indentation  243   a  and  243   b  to accommodate a placement and retention of the resilient member  250  about the arms  241   a  and  241   b.    
       FIG. 13A  shows a cross-section view of clamp  240  in a rest state with the distance d 2  separating the inner clamping surfaces  242   a  and  242   b  being less than the outer diameter d of the tubular projection  235  of plug  230 . The valve clamp  240  is configured to expand radially outward to increase the distance between the clamping surfaces  242   a  and  242   b  when forces in the directions of X 1  and X 2  are respectively applied to arms  241   a  and  241   b.    
       FIG. 13B  shows a cross-section view of the valve clamp  240  in a stressed state when the forces in the X 1  and X 2  directions are applied to the arms  241   a  and  241   b . In the stressed state the clamp  240  elongates in the directions X 1  and X 2  to cause the distance d 3  between the clamping surfaces  242   a  and  242   b  to be greater than or equal to the diameter d of the tubular projection  235  of the plug  230 . 
     In use, the valve clamp  240  resides positioned about the tubular projection  235  of the plug  230 . When the valve clamp  240  is in the rest state the clamping surfaces  242   a  and  242   b  respectively press inward against the outer walls  237   a  and  237   b  of the tubular projection  235  to cause the outer walls to deform radially inward sufficiently to cause a coming together of the inner walls  238   a  and  238   b  as shown in  FIG. 17 . The coming together of the inner walls  238   a  and  238   b  causing a closure of the passage  236 . Thereafter, the inner walls  238   a  and  238   b  of the tubular projection  235  may automatically expand outward, due to their elasticity, to cause a full or partial opening of the passage  136 . This is accomplished by respectively applying forces to the arms  241   a  and  241   b  of the clamp  240  in the X 1  and X 2  directions to cause the distance d 2  between the clamping surfaces  242   a  and  242   b  to be greater than or equal to the diameter d of the tubular projection  235  of the plug  230 .  FIGS. 15A, 15B and 16  respectively show the valve  220  in first and second open positions with the clamp  240  being in a stressed state.  FIG. 17  shows the valve  220  in the closed position when the clamp  240  is in a rest state. 
     In regard to the present disclosure, the term “rest state” encompasses any state of the clamp  240  whereby the distance between the clamping surfaces  242   a  and  242   b  is less than the outer diameter d of tubular projection  235  of the plug  230 . 
     In addition, although the tubular projection  235  has thus far been described as having a diameter, other configurations are possible. For example, the tubular projection  235  may have a rectangular outer profile and a rectangular inner profile that defines the passage  236 . In such instances, the notation “d” in  FIG. 12  represents the distance between the outer walls  237   a  and  237   b  and not a diameter. 
     According to some implementations, to enhance the closing capability of the valve clamp  240 , a resilient member  250  is disposed about the valve clamp  240  in a manner that continuously urges the clamping surfaces  241   a  and  241   b  inwardly toward one another. As noted above, according to one implementation the outer profile of the valve clamp  240  includes on each side a recess  243   a  and  243   b  in which at least portions of the resilient member  250  are retained. 
     As will be discussed in detail below, the valve actuator  270  is used to alter the state of the valve clamp  240  for the purpose of opening and closing the valve  220 . In doing so, the actuator  270  is arranged in the valve assembly  220  with freedom of axial movement along the longitudinal axis  201  in both a distal direction and a proximal direction. 
     Arranged in the valve assembly  220  is spring  260  that is configured to urge the actuator  270  in the proximal direction. According to one implementation the spring is a coil spring made of a resilient polymeric or metal material. 
       FIGS. 14A-D  show various views of the actuator  270  according to one implementation. The actuator  270  includes a proximal flange  271  having a central opening  272 . Extending distal from the proximal flange  271  is a prolongation  273 . According to one implementation a proximal end portion  273   a  of the prolongation  273  is funnel-shaped and includes a through opening that communicates the flange opening  272  with a keyhole type opening  275  located in a distal end portion  273   b  of the prolongation. The opening  275  need not be keyhole-shaped and may include an oblong configuration  275   a - b  and any shaped opening that can accommodate a widening of the tubular projection  235  of the valve plug  230  when it is clamped between the clamping surfaces  242   a  and  242   b  of clamping member  240  as will be discussed in detail below. 
     According to one implementation, a distal-most end portion of the prolongation  273  includes an annular segment  274  having a length L that is equal to or less than the depth d 1  of the recess  234  located in plug  230 . It is important to note that segment  274  need not be annular, and may include other configurations. One such configuration is shown in  FIG. 14D  wherein the segment  274  possesses a key-shaped outer profile. In any event, according to some implementations, the shape of the recess  234  in the valve plug  230  generally corresponds to the shape/outer profile of the distal-most segment  274  of the valve actuator prolongation  273 . According to some implementations, like those shown in  FIGS. 14A-D , the outer profile of the distal-most segment  274  is non-circular in order to prevent a rotation of the actuator  270  inside recess  234 . 
     Located proximal to the distal-most segment  274 , and located in opposing sides of the distal end portion  273   b  of the prolongation, are first and second side openings  276   a  and  276   b . Each of the first and second side openings  276   a  and  276   b  provides a side passage into the internal longitudinal opening  275  of the distal end portion  273   b  of the prolongation. The first and second side openings  276   a  and  276   b  are respectively sized to accommodate a passage of the arms  241   a  and  241   b  of the clamp member  240  into and out of the internal longitudinal opening  275  of the distal end portion  273   b  of the prolongation  273 , as will be described in detail below. 
     Located proximally adjacent to the first and second side openings  276   a  and  276   b  of the prolongation there respectively includes first and second external inwardly tapered walls  277   a  and  277   b . As will be described in more detail below, in use, the valve actuator  270  moves proximally and distally in the direction X as shown in  FIG. 14B . The first and second external tapered walls  277   a  and  277   b  are configured to respectively act on the arms  241   a  and  241   b  of the clamp member  240  to cause an incremented radial separation of the clamp arms from the positions shown in  FIG. 13A  to the positions shown in  FIG. 13B . 
     According to some implementations, as shown in  FIG. 14E , outer walls of the distal segment  274  of the actuator  270  comprise one or more indentation  299 . As will be discussed in more detail below, the one or more indentations  299  are configured to assist in holding the inner surfaces of clamp  240  on the actuator  270  when the valve assembly  220  is in its first operational state. 
     In the implementation shown in  FIG. 14E  the one or more indentations  299  have a concaved shape but may possess other shapes that are sufficient for holding the inner surfaces of clamp  240  on the actuator  270  when the valve assembly is in its first operational state. It is important to note that the implementation of  FIG. 14D  is applicable to all implementations disclosed herein that comprise an actuator. 
       FIG. 15A  shows a partial cross-sectional side view of IV catheter  200  with the valve assembly  220  positioned inside the catheter hub  202 . The catheter tube  206  is coupled to the distal end of the catheter hub  202  by being fitted over an elongate portion  208   b  of the ferrule  208 . According to one implementation the ferrule includes a first segment  208   a  that fits flush against an inner wall of the base  207  of the catheter hub  202 . According to one implementation, like that shown in  FIG. 15A , the distal facing wall  233  of the valve plug  230  in turn fits flush against the proximal side of the ferrule  208 . 
     According to some implementations the valve plug  230  is held in place inside the catheter hub  202  only as a result of being press-fit in the distal end of the catheter hub  202 . According to other implementations the valve plug  230  is secured inside the catheter hub  202  by use of an adhesive. According to some implementations, as shown in  FIG. 15A , one or more lips  205  protrude inward from the inner wall of the catheter hub  202  and function to hold or assist in holding the valve plug  230  in place. 
     As described previously in conjunction with the implementation of  FIG. 1 , prior to use, the IV catheter includes an introducer needle. The introducer needle is attached to a needle hub that is fixed to the catheter hub via a luer connection. In the “ready to use” state the introducer needle extends through the catheter hub and into the catheter tube with the sharpened distal tip of the needle protruding distally from the catheter tube as shown in  FIG. 1 . The use of an introducer needle applies to each of the IV catheter implementations disclosed herein. 
       FIG. 15A  shows the IV catheter  200  prior to the introducer needle being introduced therein. In  FIG. 15A  the valve assembly is shown in a first operational state that allows the introducer needle to freely pass through the valve  220  and into the inner lumen of the catheter tube  206  during an assembly of the introducer needle into the IV catheter. In this first operational state, as with all operational states of the valve assembly, a spring  260  may be held between a distal face  278  of the valve actuator flange  271  and the proximal facing wall  232  of the valve plug  230 . 
     In regard to each of the operational states of the IV catheter shown in  FIGS. 15A-18 , according to some implementations the distal surface  245  of the clamp member  240  is positioned on the proximal facing wall  232  of the valve plug  230 . According to other implementations a rigid annular plate or film  297  is disposed between the distal surface  245  of the clamp member  240  and the proximal facing wall  232  of the valve plug  230  as shown, for example, in  FIG. 15B . According to some implementations the film may comprise a lubricious film applied to the proximal facing wall  232  of the valve plug  230 . 
     According to some implementations the main body of the plug  230  is made of a first material having a first durometer and the annular plate  297  is made of a second material having a second durometer that is greater than the first durometer. According to some implementations the proximal facing surface of the annular plate  297  has a first surface roughness and the proximally facing wall  232  of the main body of the plug  230  has a second surface roughness that is greater than the first surface roughness. 
     As explained above, according to one implementation, the clamp member  240  is made of a resilient material and is arranged in the valve assembly  220  such that the clamping surfaces  242   a  and  242   b  are continuously urged toward one another. Disposed between the clamping surfaces  242   a  and  242   b  is the tubular projection  235  of the valve plug  230 . Hence, when the clamping surfaces  242   a  and  242   b  are not being held apart by the actuator  270 , they are free to move radially inward toward one another to respectively press against the outer walls  237   a  and  237   b  of the tubular projection  235  of the valve plug  230 . As explained above, a resilient member  250  may be positioned about the clamp member  240  to act on the clamping arms  241   a  and  241   b  to provide an additional force for urging the inner walls  238   a  and  238   b  of the tubular projection  235  into contact with one another to effectuate a closing of the valve  220 . 
     According to one implementation spring  260  is a coil spring that includes a distal-most coil  261  that is positioned between the outer peripheral surface of resilient member  250  and an inner surface of catheter hub  202  as shown in  FIGS. 15A-18 . 
     In the first operational state of  FIG. 15A , the actuator  270  is in a first axial position with the distal segment  274  of the actuator  270  being disposed between the clamping surfaces  242   a  and  242   b  and the tubular projection  235  of the valve plug  230 , preventing the clamping surfaces  242   a  and  242   b  from pressing against the tubular projection. As a result, a through passage is provided through the valve assembly  220  to enable an introduction of the introducer needle  209  into the IV catheter  200  allowing the needle to be threaded through the valve passageway during the assembly process without the need for a mandrel to open the passageway. The open passageway allows the needle bevel to move through the passageway without being damaged.  FIG. 16  shows the introducer needle  209  assembled in the IV catheter  200 . According to one implementation the diameter d 4  of the distal segment  273   b  of the prolongation  273  is greater than the diameter d of the tubular projection  235  of the valve plug  230 . 
       FIG. 16  shows the IV catheter  200  in a second operational state with the actuator  270  located in a second axial position distal to the first axial position. The second operational state corresponds to the “ready to use” state discussed above. When the actuator  270  is in the second axial position, the distal end segment  274  of the prolongation  273  resides inside the recess  234  of the valve plug  230  allowing the clamping surfaces  242   a  and  242   b  of the clamp member  240  to move radially inward to press against the outer walls  237   a  and  237   b  of the tubular projection  235 . Because the introducer needle  209  resides inside the tubular projection  235 , the tubular projection substantially maintains its tubular form when the actuator  270  is in the second axial position. 
     As shown in  FIG. 16 , the introducer needle  209  is affixed to a needle hub  203  that resides inside the cavity  204  of the catheter hub  202 . When the introducer needle  209  is assembled in the IV catheter  200 , the distal end surface  211  of the needle hub  203  is caused to press against the flange  271  of the actuator  270  to cause the actuator to move from the first axial position to the second axial position. During the assembly process the needle hub  203  is moved distally in the direction M. According to one implementation the needle hub  203  is equipped with a stop  212  that engages with a part of the catheter hub  202  to limit the distal advancement of the needle hub into catheter hub to ensure or prevent the actuator  270  from being moved distally beyond the second axial position. In the example of  FIG. 16  the stop  212  comprises one or more radially extending protrusions that are configured to act against a proximal end surface  213  of the catheter hub  202 . According to one implementation the stop  212  constitutes threaded part of the needle hub  203  that is configured to cooperate with the proximal luer flange  210  of the catheter hub  202  to achieve a fixation of the needle hub with the catheter hub. 
     According to some implementations, not shown in the figures, the IV catheter  200  is equipped with a needle guard that is used to cover the distal sharpened tip of the introducer  209  upon its removal from the IV catheter. According to some implementations, the needle guard is disposed between the needle hub  203  and the actuator  270 , and may in some instances transmit the force applied by the needle hub to the actuator during an assembly of the introducer needle  209  into the IV catheter. 
     With the IV catheter  200  in the “ready to use” state the clinician may introduce the catheter tube  206  into a vessel of a patient by puncturing the skin of the patient and also the wall of the vessel with the sharpened distal tip of the introducer needle  209  followed by an introduction of the distal end of the catheter tube  206  into the vessel. Upon the catheter tube  206  being successfully introduced into the vessel, the introducer needle is removed entirely from the IV catheter by disconnecting the needle hub from the catheter hub and advancing withdrawing the needle  209  proximally. 
     When the introducer needle  209  is removed from inside the tubular projection  235  of the valve plug  230 , the forces exerted by clamping surfaces  242   a  and  242   b  are capable of causing the outer walls of the tubular projection  235  to collapse causing the coming together of the opposing inner walls  238   a  and  238   b  to effectuate a closing of the valve as shown in  FIG. 17 . The configuration of  FIG. 17  represents a third operational state of the IV catheter  200 . 
     As discussed above, according to some implementations the actuator  270  includes a keyhole-shaped opening  275 . The keyhole-shaped opening includes a central opening and first and second lobes  275   a  and  275   b  that protrude from opposite sides of the central opening. According to some implementations, when the tubular projection  235  of the valve plug  230  widens when being clamped, portions of the tubular projection extend outward from the central opening and into the first and second lobes  275   a  and  275   b . According to some implementations the central opening has a circular shape and the lobes are defined by curved walls. 
     When the IV catheter  200  is in the third operational state it is poised to receive a luer connector  290  as shown in  FIG. 18  to facilitate an infusion of a therapeutic fluid into the vessel of the patient. In  FIG. 18  the IV catheter  200  is shown in a fourth operational state. The luer connector  290  typically includes an elongate body  291  that extends into the cavity  204  of the catheter hub  202  as shown in  FIG. 18 . The luer connector  290  includes a threaded part  292  that is configured to cooperate with the proximal luer flange  210  of the catheter hub  202  to lock the luer connector in a fixed position inside the catheter hub  202  when the IV catheter is in the fourth operational state. As the luer connector  290  is advanced distally into the cavity of the catheter hub  202 , at some point its distal end wall  293  makes contact with the proximal flange  271  of the actuator  270  and applies a force F to the actuator to cause the actuator to move in a distal direction to assume a third axial position as shown in  FIG. 18 . As the actuator  270  is moved distally toward the third axial position, the first and second external tapered walls  277   a  and  277   b  respectively engage the arms  241   a  and  241   b  of the clamp member  240  to cause the clamping surfaces  242   a  and  242   b  to disengage with the outer walls of the tubular projection  235  of the valve plug  230  to effectuate an opening of the valve  220 . Thereafter, the through passage  236  of the valve plug  230  communicates a through passage  292  of the luer connector  290  with the inner lumen of the catheter tube  206  to enable a therapeutic agent to be administered into the vessel of the patient. 
       FIGS. 19A-C  depict a valve actuator according to another implementation. The actuator is similar in construction to the actuator described above in conjunction with the  FIGS. 14A-E  with the exception that a portion of the through passage extending through a central region of the actuator is designed to have a diameter d 7  that is less than the outer diameter d of the tubular projection  235  of the valve plug  230 . The funnel-shaped flange opening  272  has a proximal opening  272   a  having a diameter d 5  and a distal opening having a diameter d 6  which is less than d 5 . In addition, the opening  280  that extends across a length of the distal segment  273   b  of the prolongation  273  has a diameter d 7  that is greater than diameter d 6  and less than or equal to diameter d 5 . As a result of the diametric dissimilarities an inner shoulder  282  is formed at the juncture of openings  272  and  280  as shown in  FIG. 19B . 
       FIGS. 20 and 21  respectively show the IV catheter  200  in the second and fourth operational states and having a valve actuator like that shown in  FIGS. 19A-C . In the implementations of  FIGS. 20 and 21  the inner diameter d 7  of opening  280  is slightly larger than the outer diameter d of the tubular projection  235  of valve plug  230  to create a sliding fit between the actuator and the tubular projection. However, opening  272   b  at the junction of openings  272  and  280  is less than the inner diameter of the tubular projection  235 , and according to some implementations the diameter d 6  opening  272   a  is sized to be slightly larger than the outer diameter of the introducer needle  209  such that a sliding fit exists between the actuator and the outer surface of the introducer needle shaft. The funnel-shaped opening  272  at the proximal end of the actuator in conjunction with the reduced diameter portion  272   b  operates to guide the introducer needle  209  into and through the valve assembly  220  and to place the introducer needle in concentric alignment with the valve assembly  220 . 
       FIGS. 22A and 22   b  respectively show a side view and cross-sectional side view of a valve actuator according to another implementation. The actuator is similar in construction to the actuator described above in conjunction with  FIGS. 19A-C  and additionally includes a proximal projection  283  that projects proximally from the flange  271 . In use, when the luer connector  290  is advanced into the catheter hub  202  to place the IV catheter  200  in the fourth operational state, as shown in  FIG. 23 , the proximal projection  283  functions to concentrically align the luer connector lumen  294  with the valve assembly  220 . The proximal end of the projection  283  includes a tapered lead-in  284  to facilitate a mating of the projection  283  inside the lumen of the luer connector. According to one implementation, the outer diameter d 8  of the projection  283  is slightly less than the inner diameter of the luer connector lumen  294  such that a sliding fit exists between the inner wall of lumen  294  and the outer wall of projection  283 . The concentric alignment of the luer connector  290  with the valve assembly  220  assists in ensuring a more uniform application of force applied by the distal end  293  of the luer connector  290  onto the flange  271  of the actuator. That is, the use of the proximal projection  283  safeguards against there being a skewed relationship between the luer connector and the flange of the actuator which could result in the valve assembly  220  not functioning properly. 
     In  FIGS. 14C and 19C , the flange  271  of the actuator  270  is shown having first and second curved sides  285   a  and  285   b  and first and second straight sides  286   a  and  286   b . This configuration may be included in all actuators disclosed herein. In  FIGS. 15-18, 20, 21 and 23  the curved ends  285   a  and  285   b  of the actuator  272  are shown spaced apart from the inner wall cylindrical wall  215  of the catheter hub  202 . According to other implementations the width W of the flange  271 , as shown in  FIG. 14C , is substantially equal to the inner diameter d 9  of the catheter hub  202  at least when the valve assembly  220  is in the fourth operational state in order to produce a close sliding fit between the first and second curved sides  285   a  and  285   b  of the flange  271  and the inner wall  215  of the catheter hub  202 . According to some implementations the curvature of the first and second curved sides  285   a  and  285   b  is the same or substantially the same as the curvature of the inner wall  215  of the catheter hub  202 . 
     According to some implementations the flange  271  has a circular profile in lieu of having curved and straight sides. According to such implementations the diameter of the flange  271  is substantially equal to but less than the inner diameter d 9  of the catheter hub  202 , at least when the valve assembly  220  is in the fourth operational state, in order to produce a close sliding fit between the first and second curved sides  285   a  and  285   b  of the flange  271  and the inner wall  215  of the catheter hub  202 . According to some implementations the close sliding fit is sufficient to limit, at least to some degree, a tilting of the flange  271  inside the hub cavity  204 . 
     In  FIGS. 15A-18, 20, 21 and 23  the cylindrical inner wall  215  of the catheter hub  202  is shown tapering inward such that a cross-sectional view of the hub cavity  204  is cone-shaped having a truncated distal end. In other words, the inner diameter d 9  of the cavity  204  diminishes along the length of the cavity when moving in the distal direction. According to other implementations at least the length of the cavity  204  located proximal to the proximal end of the tubular projection  235  of the valve plug  230  has a uniform inner diameter. 
     The flange  271  of the actuator  270  has a longitudinal range of motion between a proximal-most position inside the hub cavity  204  when the valve assembly is in the first operational state and a distal-most position inside the hub cavity  204  when the valve assembly is in the fourth operational state. According to some implementations at least the inner diameter of the hub cavity  204  between the proximal-most and distal-most positions is uniform. According to such implementations the width W or diameter of the actuator flange  271  is dimensioned such that the outer perimeter wall  287  of the flange rides along the inner wall  215  of the catheter hub  202  with there being a sliding fit between walls  287  and  215 . 
     In order to prevent a rotation of the actuator  270  inside the catheter hub  202 , according to some implementations the outer peripheral wall of the actuator flange  271  is equipped with one or more notches and the inner wall of the catheter hub  202  is equipped with one or more longitudinally extending protuberances fitted respectively inside the one or more notches. 
       FIGS. 24A-27  illustrate an IV catheter  300  according to another implementations. According to some implementations the IV catheter  300  is similar to the IV catheter  200  depicted in  FIGS. 15A-18  except in the construction of the valve assembly  320 . The valve assembly  320  includes a valve plug  230  like that described above. The valve assembly also includes a valve actuator  270  like that described above. 
     The valve assembly  320  differs from valve assembly  220  in that it does not include a separate valve clamp  240  or resilient member  250  or helical spring  260 . The valve assembly  320  instead includes a spring element  360  having distal first and second clamping segments  361   a  and  361   b  that are configured to move radially inward and outward to respectively effectuate an opening and closing of the tubular projection  235  passage way. The spring clip  360  is held between the distal face  278  of the valve actuator flange  271  and the proximal facing wall  232  of the valve plug  230 . The spring clip element  360  includes a proximal end segment  362  that is configured to be acted upon by the actuator flange  271  in order to cause the valve assembly  320  to assume various operational states like the first, second, third and fourth operational states described above. Additionally, the valve may operate multiple times between the third and fourth operational positions providing multi-cycle use. Like spring  260  disclosed above, the spring is assembled in valve assembly  320  such that the spring clip  360  continuously urges the actuator  271  in the proximal direction at least in the second, third and fourth operational states. The proximal end segment  362  of the spring clip  360  includes first and second ends  362   a  and  362   b  that are respectively coupled to the first and second clamping segments  361   a  and  361   b  by first and second crossing arms  363   a  and  363   b.    
       FIG. 24A  shows a partial cross-sectional side view of IV catheter  300  with the valve assembly  320  positioned inside the catheter hub  202 . The catheter tube  206  is coupled to the distal end of the catheter hub  202  by being fitted over an elongate portion  208   b  of the ferrule  208 . According to one implementation the ferrule includes a first segment  208   a  that fits flush against an inner wall of the base  207  of the catheter hub  202 . According to one implementation, like that shown in  FIG. 24 , the distal facing wall  233  of the valve plug  230  in turn fits flush against the proximal side of the ferrule  208 . 
     According to some implementations the valve plug  230  is held in place inside the catheter hub  202  only as a result of being press-fit in the distal end of the catheter hub  202 . According to other implementations the valve plug  230  is secured inside the catheter hub  202  by use of an adhesive. According to some implementations, as shown in  FIG. 24A , one or more lips  205  protrude inward from the inner wall of the catheter hub  202  and function to hold or assist in holding the valve plug  230  in place. 
     As described previously in conjunction with the implementation of  FIG. 1 , prior to use, the IV catheter includes an introducer needle. The introducer needle is attached to a needle hub that is fixed to the catheter hub via a luer connection. In the “ready to use” state the introducer needle extends through the catheter hub and into the catheter tube with the sharpened distal tip of the needle protruding distally from the catheter tube as shown in  FIG. 1 . The use of an introducer needle applies to each of the IV catheter implementations disclosed herein. 
       FIG. 24A  shows the IV catheter  300  prior to the introducer needle being introduced therein. In  FIG. 24A  the valve assembly is shown in a first operational state that allows the introducer needle to freely pass through the valve  320  and into the inner lumen of the catheter tube  206  during an assembly of the introducer needle into the IV catheter. In this first operational state, as with all operational states of the valve assembly, the spring clip  360  is held between the distal face  278  of the valve actuator flange  271  and the proximal facing wall  232  of the valve plug  230 . 
     In regard to each of the operational states of the IV catheter  300  shown in  FIGS. 24A-27 , the first and second clamping segments  361   a  and  361   b  of spring clip  360  are positioned on the proximal facing wall  232  of the valve plug  230 . According to other implementations a rigid annular plate or film  295  is disposed between the distal surface  245  of the clamp member  240  and the proximal facing wall  232  of the valve plug  230   a  as shown, for example, in  FIG. 24B . According to some implementations the film may comprise a lubricious film applied to the proximal facing wall  232  of the valve plug  320 . 
     According to some implementations the main body of the plug  230  is made of a first material having a first durometer and the annular plate  295  is made of a second material having a second durometer that is greater than the first durometer. According to some implementations the proximal facing surface of the annular plate  295  has a first surface roughness and the proximally facing wall  232  of the main body of the plug  230  has a second surface roughness that is greater than the first surface roughness. 
     The spring clip  360  is constructed and arranged in the valve assembly  320  such that the clamping segments  361   a  and  361   b  are continuously urged toward one another. Disposed between the first and second clamping segments  361   a  and  361   b  is the tubular projection  235  of the valve plug  230 . Hence, when the clamping surfaces  361   a  and  361   b  are not being held apart by the first and second external tapered walls  277   a  and  277   b  of actuator  270 , they are free to move radially inward toward one another to respectively press against the outer walls  237   a  and  237   b  of the tubular projection  235  of the valve plug  230 . 
     In the first operational state of  FIG. 24A , the actuator  270  is in a first axial position with the distal segment  274  of the actuator  270  being disposed between the clamping segments  361   a  and  361   b  and the tubular projection  235  of the valve plug  230 , preventing the clamping segments  361   a  and  361   b  of spring clip  360  from pressing against the tubular projection  235 . As a result, a through passage is provided through the valve assembly  220  to enable an introduction of the introducer needle into the IV catheter  300  allowing the needle to be threaded through the valve passageway during the assembly process without the need for a mandrel to open the passageway. As discussed above, the open passageway allows the needle bevel to move through the passageway without being damaged.  FIG. 25  shows the introducer needle  209  assembled in the IV catheter  300 . 
       FIG. 25  shows the IV catheter  300  in a second operational state with the actuator  270  located in a second axial position distal to the first axial position. The second operational state corresponds to the “ready to use” state discussed above. When the actuator  270  is in the second axial position, the distal end segment  274  of the prolongation  273  resides inside the recess  234  of the valve plug  230  allowing the clamping segments  361   a  and  361   b  of the spring clip  360  to move radially inward to press against the outer walls  237   a  and  237   b  of the tubular projection  235 . Because the introducer needle  209  resides inside the tubular projection  235 , the tubular projection substantially maintains its tubular form when the actuator  270  is in the second axial position. 
     As shown in  FIG. 25 , the introducer needle  209  is affixed to a needle hub  203  that resides inside the cavity  204  of the catheter hub  202 . When the introducer needle  209  is assembled in the IV catheter  300 , the distal end surface  211  of the needle hub  203  is caused to press against the flange  271  of the actuator  270  to cause the actuator to move from the first axial position to the second axial position. During the assembly process the needle hub  203  is moved distally in the direction M. According to one implementation the needle hub  203  is equipped with a stop  212  that engages with a part of the catheter hub  202  to limit the distal advancement of the needle hub into catheter hub to ensure or prevent the actuator  270  from being moved distally beyond the second axial position. In the example of  FIG. 25  the stop comprises one or more protrusions  212  that extend radially from the needle hub  203 . The one or more protrusions  212  are configured to act against a proximal end surface  213  of the catheter hub  202 . According to one implementation the stop  212  constitutes a threaded part of the needle hub  203  that is configured to cooperate with the proximal luer flange  210  of the catheter hub  202  to achieve a fixation of the needle hub  203  with the catheter hub  202 . 
     According to some implementations, as will be discussed in more detail below, the IV catheter  300  is equipped with a needle guard that is used to cover the distal sharpened tip of the introducer  209  upon its removal from the IV catheter. According to some implementations, the needle guard is disposed between the needle hub  203  and the actuator  270 , and may in some instances transmit the force applied by the needle hub  203  to the actuator  270  during an assembly of the introducer needle  209  into the IV catheter. 
     With the IV catheter  200  in the “ready to use” state the clinician may introduce the catheter tube  206  into a vessel of a patient by puncturing the skin of the patient and also the wall of the vessel with the sharpened distal tip of the introducer needle  209  followed by an introduction of the distal end of the catheter tube  206  into the vessel. Upon the catheter tube  206  being successfully introduced into the vessel, the introducer needle is removed entirely from the IV catheter by disconnecting the needle hub from the catheter hub and advancing the needle  209  proximally. 
     When the introducer needle  209  is removed from inside the tubular projection  235  of the valve plug  230 , the forces exerted by the clamping  361   a  and  361   b  of spring clip  360  are capable of causing the outer walls of the tubular projection  235  to collapse causing the coming together of the opposing inner walls  238   a  and  238   b  to effectuate a closing of the valve as shown in  FIGS. 26 and 29   a - c . The configuration of  FIG. 26  represents a third operational state of the IV catheter  300 . 
     As discussed above, according to some implementations the actuator  270  includes a keyhole-shaped opening  275 . The keyhole-shaped opening includes a central opening and first and second lobes  275   a  and  275   b  that protrude from opposite sides of the central opening. According to some implementations, when the tubular projection  235  of the valve plug  230  widens when being clamped, portions of the tubular projection extend outward from the central opening and into the first and second lobes  275   a  and  275   b . According to some implementations the central opening has a circular shape and the lobes are defined by curved walls. 
     When the IV catheter  300  is in the third operational state it is poised to receive a luer connector  290  as shown in  FIG. 27  to facilitate an infusion of a therapeutic fluid into the vessel of the patient. In  FIG. 27  the IV catheter  300  is shown in a fourth operational state. The luer connector  290  typically includes an elongate body  291  that extends into the cavity  204  of the catheter hub  202  as shown in  FIG. 27 . The luer connector  290  includes a threaded part  292  that is configured to cooperate with the proximal luer flange  210  of the catheter hub  202  to lock the luer connector in a fixed position inside the catheter hub  202  when the IV catheter is in the fourth operational state. As the luer connector  290  is advanced distally into the cavity of the catheter hub  202 , at some point its distal end wall  293  makes contact with the proximal flange  271  of the actuator  270  and applies a force F to the actuator to cause the actuator to move in a distal direction to assume a third axial position as shown in  FIG. 27 . As the actuator  270  is moved distally toward the third axial position, the first and second external tapered walls  277   a  and  277   b  of the actuator respectively engage the clamping segments  361   a  and  361   b  of the spring clip  360  to cause the clamping segments  361   a  and  361   b  to disengage with the outer walls of the tubular projection  235  of the valve plug  230  to effectuate an opening of the valve  320 . Thereafter, the through passage  236  of the valve plug  230  communicates a through passage  292  of the luer connector  290  with the inner lumen of the catheter tube  206  to enable a therapeutic agent to be administered into the vessel of the patient. 
     According to some implementations the actuator  270  includes a proximally extending tubular part  283  that extends proximally from the flange  271 . The proximally extending tubular part  283  is sized to fit inside the inner lumen  294  of the luer connector  290  as shown in  FIG. 28  to assist in placing the through passage of the actuator  270  and the lumen  294  of the luer connector in coaxial or near coaxial alignment to provide an unobstructed fluid pathway. According to some implementations, to avoid or minimize fluids administered through the luer connector  290  to pass distal to the actuator flange  271 , the outer diameter d 8  of the proximally extending tubular part  283  and the inner diameter of the luer connector lumen  294  are sized to produce a close sliding fit between them. 
       FIGS. 30A and 30B  illustrate an IV catheter  400  similar to IV catheter  300  according to another implementation in which the sharpened distal end  34  of the introducer needle  209  is capable of being retracted proximally into a first internal chamber  411  of the needle hub  410  as the needle  209  is removed from the catheter tube  206 .  FIG. 30A  shows the valve assembly  320  is its second operative state and  FIG. 30B  shows the valve assembly  320  in the third operational state. 
     In use, a trigger or other actuating device associated with the needle hub  410  is operative to evoke a proximal withdrawal of the sharpened distal end of the introducer needle  209  into the first internal chamber  411  through the use of a coil spring  420  that may be located in a second internal chamber  412  of the needle hub  410 . As shown in  FIGS. 30A and 30B , as the valve assembly  320  transitions from the second operational state to the third operational state the coil spring  420  axially expands inside the second chamber  412  to cause a proximal movement of the distal sharpened end  34  of the introducer needle  209  into safe storage inside the first internal chamber  411 , thus adverting a possibility of a user of the IV catheter  400  being stuck by the needle tip  34 . 
     According to one implementation the shaft of the needle just proximal to the sharpened distal tip  34  is provided with a change in profile (not shown in the figures). The change in profile region of the shaft has a width dimension (the width dimensional being orthogonal to the longitudinal axis of the introducer needle  209 ) that is greater than the diameter dimension of the remainder of the introducer needle. To limit the withdrawal of the sharpened distal tip  34  proximally beyond the first internal chamber  411 , an internal wall portion located between or at the juncture of the first and second internal chambers  411  and  412  has a cross-sectional profile that is small enough to prevent a passage of the change in profile portion of the needle across the internal wall portion. 
       FIGS. 31A and 31B  illustrate an IV catheter  500  according to another implementation having a needle guard  520  integrated therewith.  FIG. 31A  shows the valve assembly  320  is its second operational state and  FIG. 31B  shows the valve assembly  320  in the third operational state. 
     The needle guard  520  includes a base  521  from which resilient arms  522   a  and  522   b  distally extend. Each of arms  522   a  and  522   b  respectively includes a distal end segment  523   a  and  523   b  that extends radially inward toward the shaft of the introducer needle  209 . When the IV catheter is in the ready-to-use state as shown in  FIG. 31A , a portion  524   a  and  524   b  of each of segments  523   a  and  523   b  reside forced against the shaft of the introducer needle  209 . According to one implementation the needle guard  520  further includes an elongate member  525  that extends axially between the base  521  and the distal end segments  523   a  and  523   b  of the resilient arms  522   a  and  522   b.    
     The IV catheter assembly  500  also includes a needle hub  530  to which a distal end or distal end portion  531  of the introducer needle  209  is attached. When the IV catheter is in the ready-to-use state a distal end portion of the needle hub  530  is attached to a proximal end portion of the catheter hub  202  with a proximal end portion of the introducer needle  209  passing through a proximal opening in the elongate member  525  and an opening in the base  521  of the needle guard. In the ready-to-use state the introducer needle  209  passes through the needle guard  520 , the valve assembly  320  and into the catheter tube  206  such that the sharpened distal end  34  resides distal to the distal end of the catheter tube  206 . When the IV catheter is in the ready-to-use state, the inner wall of the catheter hub  202  may possess one or more inward protruding lips  528  that are configured to engage with portions  529   a  and  529   b  of the needle guard arms  521   a  and  521   b  to assist in fixing the axial position of the needle guard  520  inside the catheter hub  202 . 
     Prior to having assumed the second operational state, the valve actuator  270  is forced in a distal direction to cause the distal end segment  274  of the actuator to move distally into the recess  234  of the valve plug  230 . According to one implementation, the distally applied force originates from a distal movement of the needle hub  530  as it is being attached to the catheter hub  202 . As the needle hub  530  moves distally, the distal face  535  of the needle hub engages with the proximal face  526  of the needle guard base  521  to cause at least one of the first and second distal end segments  523   a  and  523   b  of arms  522   a  and  522   b  to press against the actuator flange  271  to cause a movement of the distal end segment  274  of the actuator  271  to move distally into the recess  234  of the valve plug  230  to cause the valve assembly to transition from the first operational state to the second operational state. 
     Upon the distal end portion of the catheter tube  206  being successfully introduced into a vein of the patient, the clinician may then remove the introducer needle from the catheter tube  206  as shown in  FIG. 31B . Removal is accomplished by detaching the needle hub  530  from the catheter hub  202  and pulling the needle hub proximally until the sharpened distal end  34  of the needle  209  resides inside a cavity of the elongate member  525  of the needle guard  520 . Upon the sharpened distal tip  34  of the needle  209  entering the elongate member  525 , the resilient arms a  522   a  and  522   b  are free to move radially inward toward one another to assume the position as shown in  FIG. 31B , locking the tip of the needle  209  inside the elongate member. 
     According to one implementation the shaft of the needle just proximal to the sharpened distal tip  34  is provided with a change in profile (not shown in the figures). The change in profile region of the introducer needle shaft has a width dimension (the width dimensional being orthogonal to the longitudinal axis of the introducer needle  209 ) that is greater than the diameter dimension of a proximal end portion  525   a  of the elongate member  525  in order to limit the withdrawal of the sharpened distal tip  34  proximally beyond the elongate member  525  as shown in  FIG. 31B . 
     When the entirety of the sharpened distal tip  34  of the introducer needle  209  being located inside the elongate member  525 , the distal end portions  523   a  and  523   b  move radially inward to reside over the distal opening  525   b  of the elongate member  525  to lock the sharpened distal tip inside the elongate member. Thereafter, the entirety of the needle guard  520  is removed from the inner cavity of the catheter hub  202  by a continued proximal withdrawal of the needle hub  530 . 
     Needle guard  520  may be similar to or the same as the needle guard implementations disclosed in co-owned U.S. Pat. No. 8,764,711 (filed Feb. 28, 2011 and issued Jul. 1, 2014), which is incorporated by reference herein in its entirety. 
       FIGS. 32A-G  show a method of loading the valve assembly  320  in its first operational state into catheter hub  202 . The method includes the use of a mandrel  600  that includes an elongate proximal handle  601  that can be gripped by an assembler or automated assembly means, during the loading process. Extending distally to the handle  601  are a central pin  603  and two or more side arms  604   a  and  604   b  that at least partially surround the central pin  603 . In the implementation of  FIG. 32D  the mandrel includes two side arms  604   a  and  604   b . In the implementation of  FIG. 32E  the mandrel includes four side arms  604   a - d . The mandrel  600  is made of rigid material that prevents any part of the mandrel from flexing during an assembling of the valve assembly  320  into the catheter hub. 
     The assembly process includes assembling together the actuator  270 , spring element  360  and plug  230  to form the valve assembly  320  in its first operational state as shown in  FIG. 32B . As explained above, when the valve  320  is in the first operational state the clamping segments  361   a  and  361   b  of the spring element  360  reside forced against the distal end segment  274  of the actuator  270  to prevent the clamping segments  361   a  and  361   b  from acting on the tubular projection  235  of the valve plug  230 . 
     The valve  320  may be pre-assembled before being placed on the mandrel  600  or valve  320  may be sequentially assembled on the mandrel  600  itself. When the valve  320  is pre-assembled before being placed on the mandrel  600 , it is done so in its first operational state, being loaded onto the mandrel  600  such that the central pin  603  of the mandrel extends through the through passage  640  of the valve assembly  320  as shown in  FIG. 32C . When the valve assembly  320  is fully loaded onto the mandrel, the distal ends  605   a  and  605   b  of the side arms  604   a  and  604   b  are positioned touching the proximal facing wall  232  of the valve plug  230  and the distal end  603   a  of the central pin  603  protrudes distally from the valve plug  230 . According to one implementation the length L 1  of each of side arms  604   a  and  604   b  is sufficiently long to ensure a gap  609  exists between the actuator  270  and a distal facing wall  608  of the mandrel from which the side arms protrude. The existence of the gap  609  guards against the actuator  270  being acted on by the mandrel  600  as the valve assembly  320  is loaded into the catheter hub  202 , ensuring that the valve assembly  320  remains in its first operational state during the loading process. 
     As shown in  FIG. 32A , the length L 2  of the central pin  603  is greater than the length L 1  of each of the side arms  604   a  and  604   b.    
     In the implementation of  FIG. 32D  the flange  271  of the actuator  272  is shown having first and second curved sides  285   a  and  285   b  and first and second straight sides  286   a  and  286   b  like that shown in  FIGS. 14C and 19C  or in actuator  270 . The existence of the first and second straight sides provides a passageway between the outer periphery of the actuator flange  271  and the inner wall of the catheter hub  202  through which the side arms  604   a  and  604   b  of the mandrel  600  pass when the valve assembly  320  is introduced into the catheter hub as shown in  FIG. 32F . 
     In the implementation of  FIG. 32E  the mandrel  600  is equipped with four projecting side walls  604   a - d  and the actuator flange  271  includes four straight sides  286   a - d  separated by four curved corners  650   a - d . According to other implementations the mandrel  600  is equipped with three projecting side walls and the actuator flange  271  includes three straight sides separated by three curved corners. The use of a mandrel having three or more projecting side walls spaced equidistantly about an outer perimeter of the mandrel ensures against a valve assembly  320  being skewed in one direction or another during its loading into the catheter hub. 
     While the valve assembly  320  is being introduced into the catheter hub  202 , the distal ends  604   a  and  604   b  of side arms  603   a  and  603   b  press against the proximal facing wall  232  of the base  231  of plug  230  to force the distal facing wall  233  of the plug  230 . According to some implementations the base  231  of the plug  230  is made of a material that prevents it from deforming during the insertion of the valve assembly  320  into the catheter hub  202 . Alternatively, the base  231  of the plug  230  may be supported on a rigid structure attached to its distal facing wall  233 . 
     As shown in  FIG. 32F , the length L 2  of the central pin  603  of mandrel  600  is sufficiently long such that it extends distally into the inner lumen of the catheter tube  206  when the valve assembly is distally positioned inside the catheter hub  202 . This feature assures a proper axial alignment of the valve assembly  320  inside the catheter hub  202  to ensure the valve passageway  640  is properly aligned with the inner lumen of the catheter tube  206 . 
     Upon the valve assembly  320  being fixed inside the catheter hub  202  as shown in  FIG. 32F , the mandrel  600  is proximally withdrawn from the catheter hub such that the IV catheter configuration of  FIG. 32G  exists, the valve assembly  320  being in its first operational state. The introducer needle  209  may thereafter be introduced into the IV catheter assembly as described in detail above. 
     The following clauses disclose in an unlimited way additional implementations. Group A through F clauses are provided. 
     Group A Clauses: 
     Clause 1. A valve assembly configured for placement inside a hub that has a proximal opening, a distal opening and an internal cavity disposed between the proximal and distal openings, the cavity defined by one or more sidewalls and a distal wall of the hub, the distal opening extending through the distal wall, the valve assembly comprising: 
     a plug made of a resilient material, the plug including a main body having a proximal facing surface and a distal facing surface, the main body including an axial through opening and being configured such that the axial through opening is in fluid communication with the distal opening of the hub, the axial through opening extending through a tubular part that has a proximal end portion that protrudes proximal to the proximal facing surface of the main body, there existing a recess in the proximal facing surface that at least partially surrounds the tubular part; 
     an actuator including a proximal flange having a proximal facing surface, the actuator including a distally protruding structure that extends distal to the proximal flange, there being an axial through opening that extends through the proximal flange and the distally protruding structure, the distally protruding structure having a proximal part, a distal part and a transverse through opening disposed between the proximal and distal parts, the distal part having an outer wall, the proximal end portion of the tubular part of the plug residing inside the distally protruding structure; and 
     a spring member including a proximal end segment and first and second clamping segments that are operatively coupled to the proximal end segment respectively by first and second arms, the spring member being configured to cause the first and second clamping segments to move radially apart from one another when a distally applied force is applied to the proximal end segment, when the actuator is in a first axial position the first and second clamping segments are urged against the outer wall of the distal part of the actuator, when the actuator is in a second axial position distal to the first axial position the distal part of the actuator is configured to move distally into the recess in the proximal facing surface of the main body of the plug and the first and second clamping segments of the spring member move radially inward into the transverse through opening of the actuator to act against the proximal end portion of the tubular part of the plug in a manner sufficient to cause a closing of the axial through opening of the plug in the proximal end portion. 
     Clause 2. The valve assembly according to clause 1, wherein the proximal part of the actuator has an outer wall that tapers distally inward, when the actuator is in the second axial position the actuator is movable distally to a third axial position distal to the second axial position to cause the tapered outer wall of the first part of the actuator to act on the first and second clamping segments in a manner that results in the first and second clamping segments to move radially outward in a manner sufficient to at least partially open the axial through opening of the plug. 
     Clause 3. The valve assembly according to clause 1, wherein when the actuator transitions from the first axial position to the second axial position the actuator is incapable of reassuming the first axial position. 
     Clause 4. The valve assembly according to clause 2, wherein when the actuator transitions from the first axial position to the second axial position the actuator is incapable of reassuming the first axial position. 
     Clause 5. The valve assembly according to clause 1, wherein the proximal end segment of the spring member abuts a distal facing surface of the proximal flange of the actuator and each of the first and second clamping segments abuts the proximal facing surface of the main body of the plug. 
     Clause 6. The valve assembly according to clause 1, wherein the proximal flange of the actuator has a first diameter dimension and the distally protruding part of the actuator has a second diameter dimension that is less than the first diameter dimension. 
     Clause 7. The valve assembly according to clause 1, wherein the axial through opening of the actuator comprises a key-hole shape. 
     Clause 8. The valve assembly according to clause 1, wherein the distal facing surface of the main body of the plug is configured to abut the distal wall of the hub. 
     Clause 9. The valve assembly according to clause 1, wherein a press fit exists between the main body of the plug and the one or more sidewalls of the hub. 
     Clause 10. The valve assembly according to clause 1, further comprising an annular plate disposed between the first and second clamping segments of the spring member and the proximal facing surface of the main body of the plug. 
     Clause 11. The valve assembly according to clause 10, wherein the first and second clamping segments of the spring member abuts a proximal facing surface of the annular plate. 
     Clause 12. The valve assembly according to clause 11, wherein the main body of the plug is made of a first material having a first durometer and the annular plate is made of a second material having a second durometer that is greater than the first durometer. 
     Clause 13. The valve assembly according to clause 11, wherein the proximal facing surface of the annular plate has a first surface roughness and the proximally facing surface of the main body of the plug has a second surface roughness that is greater than the first surface roughness. 
     Clause 14. The valve assembly according to clause 12, wherein the proximal facing surface of the annular plate has a first surface roughness and the proximally facing surface of the main body of the plug has a second surface roughness that is greater than the first surface roughness. 
     Clause 15. The valve assembly according to clause 1, wherein the outer wall of the distal part of the actuator includes an indentation in which the first and second clamping segments of the spring member reside when the actuator is in the first axial position, the indentation configured to assist in holding the first and second clamping segments on the distal part of the actuator. 
     Group B clauses: 
     Clause 1. An intravenous catheter comprising: 
     a catheter hub that has a proximal opening, a distal opening and an internal cavity disposed between the proximal and distal openings, the cavity defined by one or more sidewalls and a distal wall of the catheter hub, the distal opening extending through the distal wall; 
     a plug made of a resilient material, the plug including a main body having a proximal facing surface and a distal facing surface, the main body including an axial through opening and being configured such that the axial through opening is in fluid communication with the distal opening of the hub, the axial through opening extending through a tubular part that has a proximal end portion that protrudes proximal to the proximal facing surface of the main body, there existing a recess in the proximal facing surface that at least partially surrounds the tubular part; 
     an actuator including a proximal flange having a proximal facing surface, the actuator including a distally protruding structure that extends distal to the proximal flange, there being an axial through opening that extends through the proximal flange and the distally protruding structure, the distally protruding structure having a proximal part, a distal part and a transverse through opening disposed between the proximal and distal parts, the distal part having an outer wall, the proximal end portion of the tubular part of the plug residing inside the distally protruding structure; and 
     a spring member including a proximal end segment and first and second clamping segments that are operatively coupled to the proximal end segment respectively by first and second arms, the spring member being configured to cause the first and second clamping segments to move radially apart from one another when a distally applied force is applied to the proximal end segment, when the actuator is in a first axial position the first and second clamping segments are urged against the outer wall of the distal part of the actuator, when the actuator is in a second axial position distal to the first axial position the distal part of the actuator is configured to move distally into the recess in the proximal facing surface of the main body of the plug and the first and second clamping segments of the spring member move radially inward into the transverse through opening of the actuator to act against the proximal end portion of the tubular part of the plug in a manner sufficient to cause a closing of the axial through opening of the plug in the proximal end portion. 
     Clause 2. The catheter assembly according to clause 1, wherein the proximal part of the actuator has an outer wall that tapers distally inward, when the actuator is in the second axial position the actuator is movable distally to a third axial position to cause the tapered outer wall of the first part of the actuator to act on the first and second clamping segments in a manner that results in the first and second clamping segments to move radially outward in a manner sufficient to at least partially open the axial through opening of the plug. 
     Clause 3. The catheter assembly according to clause 1, wherein when the actuator transitions from the first axial position to the second axial position the actuator is incapable of reassuming the first axial position. 
     Clause 4. The catheter assembly according to clause 2, wherein when the actuator transitions from the first axial position to the second axial position the actuator is incapable of reassuming the first axial position. 
     Clause 5. The catheter assembly according to clause 1, wherein the proximal end segment of the spring member abuts a distal facing surface of the proximal flange of the actuator and each of the first and second clamping segments abuts the proximal facing surface of the main body of the plug. 
     Clause 6. The catheter assembly according to clause 1, wherein the proximal flange of the actuator has a first diameter dimension and the distally protruding part of the actuator has a second diameter dimension that is less than the first diameter dimension. 
     Clause 7. The catheter assembly according to clause 1, wherein the axial through opening of the actuator comprises a key-hole shape. 
     Clause 8. The catheter assembly according to clause 1, wherein the distal facing surface of the main body of the plug is configured to abut the distal wall of the catheter hub. 
     Clause 9. The catheter assembly according to clause 1, wherein a press fit exists between the main body of the plug and the one or more sidewalls of the catheter hub. 
     Clause 10. The catheter assembly according to clause 1, further comprising an annular plate disposed between the first and second clamping segments of the spring member and the proximal facing surface of the main body of the plug. 
     Clause 11. The catheter assembly according to clause 10, wherein the first and second clamping segments of the spring member abut a proximal facing surface of the annular plate. 
     Clause 12. The catheter assembly according to clause 11, wherein the main body of the plug is made of a first material having a first durometer and the annular plate is made of a second material having a second durometer that is greater than the first durometer. 
     Clause 13. The catheter assembly according to clause 11, wherein the proximal facing surface of the annular plate has a first surface roughness and the proximally facing surface of the main body of the plug has a second surface roughness that is greater than the first surface roughness. 
     Clause 14. The catheter assembly according to clause 12, wherein the proximal facing surface of the annular plate has a first surface roughness and the proximally facing surface of the main body of the plug has a second surface roughness that is greater than the first surface roughness. 
     Clause 15. The catheter assembly according to clause 1, wherein the outer wall of the distal part of the actuator includes an indentation in which the first and second clamping segments of the spring member reside when the actuator is in the first axial position, the indentation configured to assist in holding the first and second clamping segments on the distal part of the actuator. 
     Clause 16. The catheter assembly according to clause 1, further comprising a ferrule positioned between the distal wall of the catheter hub and the distal facing surface of the main body of the plug. 
     Clause 17. The catheter assembly according to clause 16, further comprising an elongate tube having a proximal end and a distal end, the proximal end being secured to the ferrule. 
     Clause 18. The catheter assembly according to clause 1, further comprising an introducer needle having a proximal end portion, a sharpened distal tip and a shaft extending between the proximal end and the sharpened distal tip, the shaft extending through the axial through opening the plug and the axial through opening of the actuator when the actuator is in the second axial position. 
     Clause 19. The catheter assembly according to clause 18, further comprising an elongate catheter tube having a proximal end, a distal end and an inner lumen extending through and between the proximal and distal ends, the proximal end of the catheter tube being fixed to a distal end portion of the catheter hub, the shaft of the introducer needle extending through the inner lumen of the catheter tube. 
     Clause 20. The catheter assembly according to clause 18, wherein the proximal end portion of the introducer needle is coupled to a needle hub, the needle hub being detachably coupled to a proximal end of the catheter hub. 
     Clause 21. The catheter assembly according to clause 20, wherein the needle hub has a distally facing surface that presses against the proximal facing surface of the proximal flange of the actuator to cause the actuator to transition from the first axial position to the second axial position. 
     Clause 22. The catheter assembly according to clause 18, wherein the shaft of the introducer needle has a first diameter and the inner diameter of the axial through opening extending through the proximal end portion of tubular part of the plug having a second diameter dimension, the first diameter dimension being no more than 20% greater than the second diameter dimension. 
     Clause 23. The catheter assembly according to clause 1, wherein the proximal facing surface of the main body of the plug has applied thereto a lubricious film, the first and second clamping segments of the spring member being positioned on a surface of the lubricious film. 
     Clause 24. The catheter assembly according to clause 20, wherein the sharpened distal tip of the introducer needle is retractable into the needle hub. 
     Clause 25. The catheter assembly according to clause 20, further comprising a needle guard disposed between the distally facing surface of the needle hub and the proximal flange of the actuator. 
     Clause 26. The catheter assembly according to clause 25, wherein the needle guard has a distally facing surface that presses against the proximal facing surface of the proximal flange of the actuator to cause the actuator to transition from the first axial position to the second axial position. 
     Group C Clauses: 
     Clause 1. A valve assembly configured for placement inside a hub that has a proximal opening, a distal opening and an internal cavity disposed between the proximal and distal openings, the cavity defined by one or more sidewalls and a distal wall, the distal opening extending through the distal wall, the valve assembly comprising: 
     a plug made of a resilient material, the plug including a main body having a proximal facing surface and a distal facing surface, the main body including an axial through opening and being configured such that the axial through opening is in fluid communication with the distal opening of the hub, the axial through opening extending through a tubular part that has a proximal end portion that protrudes proximal to the proximal facing surface of the main body, there existing a recess in the proximal facing surface that at least partially surrounds the tubular part; 
     an actuator including a proximal flange having a proximal facing surface, the actuator including a distally protruding structure that extends distal to the proximal flange, there being an axial through opening that extends through the proximal flange and the distally protruding structure, the distally protruding structure having a proximal part, a distal part and a transverse through opening disposed between the proximal and distal parts, the distal part having an outer wall, the proximal end portion of the tubular part of the plug residing inside the distally protruding structure; 
     a clamping device having first and second clamping arms that are resiliently urged inward toward one another, the clamping device having an axial through opening through which the distally protruding structure of the actuator passes, when the actuator is in a first axial position the first and second clamping arms are urged against the outer wall of the distal part of the actuator, when the actuator is in a second axial position distal to the first axial position the distal part of the actuator is configured to move distally into the recess in the proximal facing surface of the main body of the plug and the first and second clamping arms move radially inward into the transverse through opening of the actuator to act against the proximal end portion of the tubular part of the plug in a manner sufficient to cause a closing of the axial through opening of the plug at the proximal end portion; and 
     a spring that acts on the actuator to urge the actuator in a proximal direction when the actuator is in the second axial position. 
     Clause 2. The valve assembly according to clause 1, wherein the proximal part of the actuator has an outer wall that tapers distally inward, when the actuator is in the second axial position the actuator is movable distally to a third axial position to cause the tapered outer wall of the first part of the actuator to act on the first and second clamping arms in a manner that results in the first and second clamping arms to move radially outward in a manner sufficient to at least partially open the axial through opening of the plug. 
     Clause 3. The valve assembly according to clause 1, wherein when the actuator transitions from the first axial position to the second axial position the actuator is incapable of reassuming the first axial position. 
     Clause 4. The valve assembly according to clause 2, wherein when the actuator transitions from the first axial position to the second axial position the actuator is incapable of reassuming the first axial position. 
     Clause 5. The valve assembly according to clause 1, wherein the spring has a proximal end that abuts a distal facing surface of the proximal flange of the actuator and a distal end that abuts the proximal facing surface of the main body of the plug. 
     Clause 6. The valve assembly according to clause 1, wherein the first and second clamping arms are urged radially inward at least in part by a resilient O-ring that circumscribes the clamping device. 
     Clause 7. The valve assembly according to clause 1, wherein the proximal flange of the actuator has a first diameter dimension and the distally protruding part of the actuator has a second diameter dimension that is less than the first diameter dimension. 
     Clause 8. The valve assembly according to clause 1, wherein the axial through opening of the actuator comprises a key-hole shape. 
     Clause 9. The valve assembly according to clause 1, wherein the distal facing surface of the main body of the plug is configured to abut the distal wall of the hub. 
     Clause 10. The valve assembly according to clause 1, wherein a press fit exists between the main body of the plug and the one or more sidewalls of the hub. 
     Clause 11. The valve assembly according to clause 1, wherein the clamping device has a distal facing surface that abuts the proximal facing surface of the main body of the plug. 
     Clause 12. The valve assembly according to clause 1, further comprising an annular plate disposed between a distal facing surface of the clamping device and the proximal facing surface of the main body of the plug. 
     Clause 13. The valve assembly according to clause 12, wherein a distal facing surface of the clamping device abuts a proximal facing surface of the annular plate. 
     Clause 14. The valve assembly according to clause 13, wherein the main body of the plug is made of a first material having a first durometer and the annular plate is made of a second material having a second durometer that is greater than the first durometer. 
     Clause 15. The valve assembly according to clause 13, wherein the proximal facing surface of the annular plate has a first surface roughness and the proximally facing surface of the main body of the plug has a second surface roughness that is greater than the first surface roughness. 
     Clause 16. The valve assembly according to clause 14, wherein the proximal facing surface of the annular plate has a first surface roughness and the proximally facing surface of the main body of the plug has a second surface roughness that is greater than the first surface roughness. 
     Clause 17. The valve assembly according to clause 1, wherein the outer wall of the distal part of the actuator includes an indentation in which a distal end segment of the spring resides when the actuator is in the first axial position, the indentation configured to assist in holding the distal end segment on the distal part of the actuator. 
     Group D Clauses: 
     Clause 1. An intravenous catheter comprising: 
     a catheter hub that has a proximal opening, a distal opening and an internal cavity disposed between the proximal and distal openings, the cavity defined by one or more sidewalls and a distal wall of the catheter hub, the distal opening extending through the distal wall; 
     a plug made of a resilient material, the plug including a main body having a proximal facing surface and a distal facing surface, the main body including an axial through opening and being configured such that the axial through opening is in fluid communication with the distal opening of the hub, the axial through opening extending through a tubular part that has a proximal end portion that protrudes proximal to the proximal facing surface of the main body, there existing a recess in the proximal facing surface that at least partially surrounds the tubular part; 
     an actuator including a proximal flange having a proximal facing surface, the actuator including a distally protruding structure that extends distal to the proximal flange, there being an axial through opening that extends through the proximal flange and the distally protruding structure, the distally protruding structure having a proximal part, a distal part and a transverse through opening disposed between the proximal and distal parts, the distal part having an outer wall, the proximal end portion of the tubular part of the plug residing inside the distally protruding structure; 
     a clamping device having first and second clamping arms that are resiliently urged inward toward one another, the clamping device having an axial through opening through which the distally protruding structure of the actuator passes, when the actuator is in a first axial position the first and second clamping arms are urged against the outer wall of the distal part of the actuator, when the actuator is in a second axial position distal to the first axial position the distal part of the actuator is configured to move distally into the recess in the proximal facing surface of the main body of the plug and the first and second clamping arms move radially inward into the transverse through opening of the actuator to act against the proximal end portion of the tubular part of the plug in a manner sufficient to cause a closing of the axial through opening of the plug at the proximal end portion; and 
     a spring that acts on the actuator to urge the actuator in a proximal direction when the actuator is in the second axial position. 
     Clause 2. The catheter assembly according to clause 1, wherein the proximal part of the actuator has an outer wall that tapers distally inward, when the actuator is in the second axial position the actuator is movable distally to a third axial position to cause the tapered outer wall of the first part of the actuator to act on the first and second clamping arms in a manner that results in the first and second clamping arms to move radially outward in a manner sufficient to at least partially open the axial through opening of the plug. 
     Clause 3. The catheter assembly according to clause 1, wherein when the actuator transitions from the first axial position to the second axial position the actuator is incapable of reassuming the first axial position. 
     Clause 4. The catheter assembly according to clause 2, wherein when the actuator transitions from the first axial position to the second axial position the actuator is incapable of reassuming the first axial position. 
     Clause 5. The catheter assembly according to clause 1, wherein the spring has a proximal end and a distal end, the proximal end of the spring abutting a distal facing surface of the proximal flange of eh actuator, the distal end of the spring abutting the proximal facing surface of the main body of the plug. 
     Clause 6. The catheter assembly according to clause 1, wherein the proximal flange of the actuator has a first diameter dimension and the distally protruding part of the actuator has a second diameter dimension that is less than the first diameter dimension. 
     Clause 7. The catheter assembly according to clause 1, wherein the axial through opening of the actuator comprises a key-hole shape. 
     Clause 8. The catheter assembly according to clause 1, wherein the distal facing surface of the main body of the plug is configured to abut the distal wall of the catheter hub. 
     Clause 9. The catheter assembly according to clause 1, wherein a press fit exists between the main body of the plug and the one or more sidewalls of the catheter hub. 
     Clause 10. The catheter assembly according to clause 1, further comprising an annular plate disposed between the first and second clamping segments of the spring member and the proximal facing surface of the main body of the plug. 
     Clause 11. The catheter assembly according to clause 10, wherein the first and second clamping segments of the spring member abut a proximal facing surface of the annular plate. 
     Clause 12. The catheter assembly according to clause 11, wherein the main body of the plug is made of a first material having a first durometer and the annular plate is made of a second material having a second durometer that is greater than the first durometer. 
     Clause 13. The catheter assembly according to clause 11, wherein the proximal facing surface of the annular plate has a first surface roughness and the proximally facing surface of the main body of the plug has a second surface roughness that is greater than the first surface roughness. 
     Clause 14. The catheter assembly according to clause 12, wherein the proximal facing surface of the annular plate has a first surface roughness and the proximally facing surface of the main body of the plug has a second surface roughness that is greater than the first surface roughness. 
     Clause 15. The catheter assembly according to clause 1, wherein the outer wall of the distal part of the actuator includes an indentation in which the first and second clamping segments of the spring member reside when the actuator is in the first axial position, the indentation configured to assist in holding the first and second clamping segments on the distal part of the actuator. 
     Clause 16. The catheter assembly according to clause 1, further comprising a ferrule positioned between the distal wall of the catheter hub and the distal facing surface of the main body of the plug. 
     Clause 17. The catheter assembly according to clause 16, further comprising an elongate tube having a proximal end and a distal end, the proximal end being secured to the ferrule. 
     Clause 18. The catheter assembly according to clause 1, further comprising an introducer needle having a proximal end portion, a sharpened distal tip and a shaft extending between the proximal end and the sharpened distal tip, the shaft extending through the axial through opening the plug and the axial through opening of the actuator when the actuator is in the second axial position. 
     Clause 19. The catheter assembly according to clause 18, further comprising an elongate catheter tube having a proximal end, a distal end and an inner lumen extending through and between the proximal and distal ends, the proximal end of the catheter tube being coupled to a distal end portion of the catheter hub, the shaft of the introducer needle extending through the inner lumen of the catheter tube. 
     Clause 20. The catheter assembly according to clause 18, wherein the proximal end portion of the introducer needle is coupled to a needle hub, the needle hub being detachably coupled to a proximal end of the catheter hub. 
     Clause 21. The catheter assembly according to clause 20, wherein the needle hub has a distally facing surface that presses against the proximal facing surface of the proximal flange of the actuator to cause the actuator to transition from the first axial position to the second axial position 
     Clause 22. The catheter assembly according to clause 18, wherein the shaft of the introducer needle has a first diameter and the inner diameter of the axial through opening extending through the proximal end portion of tubular part of the plug having a second diameter dimension, the first diameter dimension being no more than 20% greater than the second diameter dimension. 
     Clause 23. The catheter assembly according to clause 1, wherein the proximal facing surface of the main body of the plug has applied thereto a lubricious film, the first and second clamping segments of the spring member being positioned on a surface of the lubricious film. 
     Clause 24. The catheter assembly according to clause 20, wherein the sharpened distal tip of the introducer needle is retractable into the needle hub. 
     Clause 25. The catheter assembly according to clause 20, further comprising a needle guard disposed between the distally facing surface of the needle hub and the proximal flange of the actuator. 
     Clause 26. The catheter assembly according to clause 25, wherein the needle guard has a distally facing surface that presses against the proximal facing surface of the proximal flange of the actuator to cause the actuator to transition from the first axial position to the second axial position. 
     Group E Clauses: 
     Clause 1. An assembly comprising: 
     a hub having a proximal opening, a distal opening and an internal cavity disposed between the proximal and distal openings, the cavity defined by one or more sidewalls and a bottom wall of the hub, the distal opening extending through the bottom wall: 
     a catheter tube secured to a distal end of the hub and having an inner lumen in fluid communication with the distal opening of the hub; 
     a valve located inside the hub, the valve including a proximal flange, a distal flange and a tubular part extending between the proximal and distal flanges, the valve being configured to assume an open position and closed position, the valve being made of a resilient material and constructed such that the valve is continuously urged toward the closed position, in the open position fluid flow is permitted through an opening that extends through the proximal and distal flanges and the tubular part, in the closed position fluid flow is impeded through the opening, the valve being constructed such that when a distally applied force is applied to a proximal face of the proximal flange the valve transitions from the closed position to the open position and subsequently returns to the closed position when the distally applied force is removed. 
     Clause 2. The assembly according to clause 1, wherein a distal face of the distal flange abuts the bottom wall of the hub. 
     Clause 3. The assembly according to clause 2, wherein the distal flange includes an opening that communicates the tubular part of the valve with the catheter tube when the valve is in the open position and in the closed position. 
     Clause 4. The assembly according to clause 1, wherein the proximal face of the proximal flange is arranged at a first angle with respect to a longitudinal axis of the hub when the valve is in the open position and is arranged at a second angle with respect to the longitudinal axis of the hub when the valve is in the closed position, the first angle being greater than the second angle. 
     Clause 5. The assembly according to clause 1, wherein the distal flange has a circumferential surface that presses against the one or more sidewalls of the hub to hold the valve securely inside the cavity of the hub. 
     Clause 6. The assembly according to clause 1, wherein the distal flange has a circumferential surface that presses against the one or more sidewalls of the hub to hold the valve securely inside the cavity of the hub without the use of an adhesive. 
     Clause 7. The assembly according to clause 1, wherein the proximal flange has a first diameter when the valve is in the open position and a second diameter when the valve is in the closed position, the first diameter being greater than the second diameter. 
     Clause 8. The assembly according to clause 1, wherein the tubular part of the valve has walls that press against one another to impede fluid flow through the tubular part when the valve is in the closed position and the walls do not press against one another to permit fluid flow through the tubular part when the valve is in the open position. 
     Clause 9. An assembly comprising: 
     a hub having a proximal opening, a distal opening and an internal cavity disposed between the proximal and distal openings, the cavity defined by one or more sidewalls and a bottom wall of the hub, the distal opening extending through the bottom wall: 
     a catheter tube secured to a distal end of the hub and having an inner lumen in fluid communication with the distal opening of the hub; 
     an introducer needle residing in the catheter tube and having an outer wall and a distal tip, the distal tip extending distally from a distal end of the catheter tube, 
     a valve disposed about the introducer needle inside the hub, the valve including a proximal flange, a distal flange and a tubular part extending between the proximal and distal flanges, the valve being configured to assume an open position and a closed position, in the open position a through passage is provided that extends through the proximal and distal flanges and the tubular part, in the closed position the through passage is closed, the valve being made of a resilient material and constructed such that the valve is continuously urged toward the closed position, when the introducer needle resides inside the catheter tube the outer wall of the introducer needle causes the valve to assume the open position, when the introducer needle is removed from the catheter tube the valve assumes the closed position, when the valve is in the closed position the valve is constructed such that when a distally applied force is applied to a proximal face of the proximal flange the valve transitions from the closed position to the open position and subsequently returns to the closed position when the distally applied force is removed. 
     Group F Clauses: 
     Clause 1. An assembly comprising: 
     a hub having a proximal opening, a distal opening and an internal cavity disposed between the proximal and distal openings, the cavity defined by one or more sidewalls and a bottom wall of the hub, the distal opening extending through the bottom wall; 
     a catheter tube secured to a distal end of the hub and having a tubular wall with an inner surface that defines an inner lumen, the catheter tube having a proximal portion that resides inside the cavity of the hub and a distal portion that resides outside the hub, the proximal portion having an outer surface; 
     a valve located inside the hub that is transitional between an open position and a closed position, the valve including a base having a through opening through which a portion of the catheter tube passes, the valve including first and second arms that are positioned about the outer surface of the proximal portion of the catheter tube, each of the first and second arms including a first section having a distal end and a proximal end, the distal end of the first section being coupled to the base, the proximal end of the first section being disposed radially inward of the distal end of the first section, each of the first and second arms including a second section having a distal end and a proximal end, the distal end of the second section being coupled to the distal end of the first section, the proximal end of the second section being disposed radially outward of the distal end of the section, the proximal end of the first section of the first arm being coupled to the distal end of the second section of the first arm at a first location, the proximal end of the first section of the second arm being coupled to the distal end of the second section of the second arm at a second location, each of the first and second arms being made of a resilient material and constructed such that the first and second locations are continuously urged toward one another to position the valve in the closed position, in the closed position of the valve the first and second locations press against the outer surface of the proximal portion of the catheter tube to cause a collapse of the tubular wall in the proximal portion that results in a full or substantially full closing of the inner lumen of the catheter tube, in the open position of the valve the first and second locations are positioned radially apart from one another so as not to press against the outer surface of the proximal portion of the catheter tube that results in a full or substantially full opening.