Patent Publication Number: US-2021187252-A1

Title: Catheter with threading flash confirmation

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority to U.S. Provisional Patent Application No. 62/575,045, filed on Oct. 20, 2017, which is hereby fully incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates generally to intravenous catheters, and more particularly intravenous catheter assemblies configured to provide a two-stage visual indication during catheter insertion into a vein of a patient. 
     BACKGROUND 
     Intravenous (IV) therapy is a versatile technique used for the administration of medical fluids to and withdrawal of bodily fluids from patients. IV therapy has been used for various purposes such as the maintenance of fluid and electrolyte balance, the transfusion of blood, the administration of nutritional supplements, chemotherapy, and the administration of drugs and medications. These fluids, collectively referred to herein as medicaments, may be administered intravenously by injection through a hypodermic needle, or intermittently or continuously by infusion using a needle or catheter. A common intravenous access device utilized by clinicians is the peripheral IV catheter. 
     A peripheral IV catheter is made of a soft, flexible plastic or silicone, generally between fourteen to twenty-four gauge in size. In conventional venipuncture procedure, a catheter is inserted into a vein of the patient&#39;s hand, foot, or the inner aspect of the arm or any vein in the body that will accept an IV catheter. In order to place the IV catheter into the patient&#39;s vein, a sharp introducer needle is used to puncture the skin, tissue, and vein wall to provide a path for placement of the catheter into the vein. 
     Referring to  FIGS. 1A-B , a conventional IV needle assembly  50  configured for insertion of an “over the needle” catheter  52  is depicted. Catheter  52  generally includes a catheter tube  54  having a distal end  56  for insertion into a biological site, a proximal end  58  and a flexible wall defining a lumen extending therebetween. Frequently, the proximal end  58  of the catheter tube  54  is operably coupled to a catheter hub  60 . Catheter  52  can be operably coupleable to the needle assembly  50 , in part by positioning the catheter  52  coaxially over a needle  62  of the needle assembly. The catheter  52  thus rides with the needle  62  through the skin, tissue and vein wall into the patient&#39;s vein. Once the catheter tube  54  has entered into the patient&#39;s vein, the catheter  52  can be advanced further into the vein as desired and the needle  62  can be withdrawn from the catheter. The catheter  52  can then be secured into place on the patient, and connected to an IV fluid supply. In some instances, the catheter  52  can include an extension tube  64  having a clamp  66  and a Luer lock connector  68  for connection to an IV fluid supply. Such catheters are often referred to as closed system catheters, as they typically include a septum that seals the needle path after the needle has been withdrawn from the catheter, thereby inhibiting blood or bodily fluid from the patient from escaping from the catheter to the ambient environment. 
     SUMMARY OF THE DISCLOSURE 
     Embodiments of the present disclosure address problems associated with catheter insertion. In particular, embodiments of the present disclosure provide direct, two-stage, line-of-sight monitoring for successful placement of both an insertion needle and a catheter assembly of an intravenous catheter assembly into a vein of a patient. Accordingly, intravenous catheter assemblies of the present disclosure enable a clinician to: (1) ensure that the needle has entered into the vein of a patient; and (2) ensure that the catheter is being properly threaded into the vein of the patient, while the catheter is being inserted. 
     Catheter assemblies of the prior art do not provide a visual indication of proper placement of the catheter while the catheter is being threaded into the vein of a patient. Rather, proper catheter placement is not confirmed until either the needle has been completely removed, or the catheter assembly has been vented, thereby enabling blood from the patient to flow through the catheter into a flash chamber. In either case, such confirmation does not take place until catheter insertion is complete. 
     Accordingly, with catheter assemblies of the prior art it is possible to receive a first positive visual indication that the needle has entered into the vein of a patient, while the catheter (which is positioned proximal to the sharp distal tip of the needle) has not entered into the patient&#39;s vein. In these circumstances, it is possible to thread the catheter into the patient along a path outside of the patient&#39;s vein. In other circumstances, the catheter may temporarily enter into the patient&#39;s vein, only to be inadvertently retracted out of the patient&#39;s vein as the needle is withdrawn. In still other circumstances, the catheter may temporarily enter into the patient&#39;s vein, but inadvertently be pushed through the opposite wall of the patient&#39;s vein during insertion. In all of these circumstances, it is generally not recognized that the catheter has not been properly placed within the vein of the patient, until the catheter has been fully inserted and the needle has been withdrawn. In such cases, the clinician must attempt the procedure again, thereby causing pain and discomfort to the patient, and extending the length of what is otherwise a relatively quick procedure. 
     One embodiment of the present disclosure provides an intravenous catheter assembly configured to provide a two-stage visual indication during catheter insertion into a vein of a patient. The intravenous catheter assembly includes an insertion needle and a catheter. The insertion needle can have a sharp distal tip, a proximal end, and a radial wall extending therebetween. The insertion needle can define a fluid conduit extending between an inlet positioned on the sharp distal tip and an outlet positioned on the radial wall. The catheter can be coaxially positioned over the insertion needle, having a distal end, a proximal end, and a flexible wall defining a lumen extending therebetween. The catheter can be initially coaxially positioned over the insertion needle in a first position in which the sharp distal tip of the insertion needle extends beyond the distal end of the catheter. An annular space between the radial wall of the insertion needle and the flexible wall of the catheter can be divided into a first axial chamber and a second axial chamber by a formed region of the flexible wall having a diameter configured to inhibit flow between the first axial chamber and the second axial chamber, wherein the outlet of the fluid conduit is position within the first axial chamber, thereby providing a first visual indication during catheter insertion by enabling blood from the vein of the patient to flow into the first axial chamber. The catheter an insertion needle can be shiftable and/or translate axially relative to one another to a second position during catheter insertion, such that the outlet of the fluid conduit is shifted from the first axial chamber to the second axial chamber, thereby providing a second visual indication during catheter insertion by enabling blood from the vein of the patient to flow into the second axial chamber. 
     Another embodiment of the present disclosure provides a method of providing a two-stage visual indication during catheter insertion into a vein of a patient. The method includes the steps of: coaxially positioning a catheter over an insertion needle in an initial position in which a sharp distal tip of the insertion needle extends beyond a distal end of the catheter, and an annular space between a radial wall of the insertion needle and a flexible wall of the catheter is divided into a first chamber and a second chamber by a formed region in the flexible wall having a diameter configured to inhibit flow between the first axial chamber and the second axial chamber, the insertion needle defining a fluid conduit extending between an inlet position on the sharp distal tip in an outlet positioned on the radial wall, wherein in the initial position, the outlet is positioned within the first axial chamber; inserting the sharp distal tip of the insertion needle into the vein of a patient, thereby providing a first visual indication during catheter insertion by enabling blood from the vein of the patient to flow through the fluid conduit and into the first axial chamber; withdrawing the insertion needle and threading the catheter into the vein of the patient, thereby shifting the outlet of the fluid conduit from the first axial chamber to the second axial chamber, thereby providing a second visual indication during catheter insertion by enabling blood from the vein of the patient to flow through the fluid conduit and into the second axial chamber. 
     In one embodiment, the insertion needle is a hollow hypodermic needle. In one embodiment the inlet of the fluid conduit is in the distal opening of the hollow hypodermic needle and the outlet is a notch defined by the radial wall of the hollow hypodermic needle. In one embodiment, the insertion needle is a solid member defining a fluid conduit groove positioned on the radial wall. In one embodiment the inlet of the fluid conduit is defined by a distal end of the groove and the outlet is defined by a proximal end of the groove. In one embodiment the distal end of the catheter is formed to inhibit distal flow from the first axial chamber. 
     The summary above is not intended to describe each illustrated embodiment or every implementation of the present disclosure. The figures and the detailed description that follow more particularly exemplify these embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure can be more completely understood in consideration of the following detailed description of various embodiments of the disclosure, in connection with the accompanying drawings, in which: 
         FIG. 1A  is a perspective view depicting a conventional IV needle assembly with a catheter positioned over a needle. 
         FIG. 1B  is a perspective view depicting the conventional IV needle assembly of  FIG. 1A  with the catheter removed from the needle. 
         FIG. 2  is a plan view depicting an intravenous catheter assembly in accordance with an embodiment of the disclosure. 
         FIG. 3  is a plan view depicting an intravenous catheter assembly in accordance with an alternative embodiment of the disclosure. 
         FIG. 4A  is a partial, cross-sectional view of a catheter tube coaxially positioned over an insertion needle, in accordance with an embodiment of the disclosure. 
         FIG. 4B  is a partial, cross-sectional view of the catheter tube and insertion needle of  FIG. 4A , in which the catheter tube and insertion needle have been shifted relative to one another. 
         FIG. 5A  is a partial, cross-sectional view of a catheter tube coaxially positioned over an insertion needle, in accordance with an alternative embodiment of the disclosure. 
         FIG. 5B  is a partial, cross-sectional view of the catheter tube and insertion needle of  FIG. 5A , in which the catheter tube and insertion needle have been shifted relative to one another. 
         FIG. 6A  depicts the insertion of an insertion catheter assembly into a vein of a patient, in accordance with an embodiment of the disclosure. 
         FIG. 6B  depicts an advancement of a catheter tube over an insertion needle, in accordance with an embodiment of the disclosure. 
         FIG. 6C  depicts a threading of a catheter tube into a vein of a patient, in accordance with an embodiment of the disclosure. 
         FIG. 7A  is a partial, cross-sectional view of a catheter tube coaxially positioned over an insertion needle in accordance with an alternative embodiment of the disclosure. 
         FIG. 7B  depicts an insertion of the insertion needle and catheter tube of  FIG. 7A  into a vein of a patient. 
         FIG. 7C  depicts a threading of the catheter tube of  FIG. 7B  into a vein of a patient. 
     
    
    
     While embodiments of the disclosure are amenable to various modifications and alternative forms, specifics thereof shown by way of example in the drawings will be described in detail. It should be understood, however, that the intention is not to limit the disclosure to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the subject matter as defined by the claims. 
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1A-B , a conventional IV catheter assembly  50  is depicted. Details of the conventional IV catheter assembly  50  are described in the Background section above. 
     Referring to  FIG. 2 , an intravenous catheter assembly  100  is depicted in accordance with an embodiment of the disclosure. In one embodiment, the intravenous catheter assembly  100  includes a catheter assembly  102  and a catheter insertion device  104 . Various types of catheter insertion devices  104  are marketed by Smiths Medical ASD, Inc. of St. Paul, Minn., under the TELCO trademark. One embodiment of the catheter insertion device  104  (such as that depicted in  FIGS. 1A-B ) is described in U.S. Pat. Nos. 7,291,130 and 8,257,322 (depicting an IV catheter insertion device marketed by Smiths ASD, under the INTUITIV trademark) both of which are incorporated by reference herein. 
     The catheter insertion device  104  can include an insertion needle  106  operably coupled to a needle hub  108 . The insertion needle  106  can include an elongate, cylindrically shaped radial wall  109  defining a lumen that extends between a sharpened distal needle tip  110  and a proximal end  112 . The sharp distal tip  110  can be constructed and arranged to pierce the skin of a subject during catheter insertion. For example, in one embodiment, the sharp distal tip  110  can include a V-point designed to reduce the penetration force used to penetrate the needle  106  and a portion of the catheter assembly  102  through the skin, tissue, and vein wall of a subject. In one embodiment, the length of the insertion needle  106  can be extended to aid in the insertion of the catheter assembly  102  into obese patients. 
     It is to be appreciated that the term “distal,” as used herein, refers to the direction along an axis the lies parallel to the insertion needle  106  of the intravenous catheter assembly  100  that is closest to the subject during catheter insertion. Conversely, the term “proximal,” as used herein, refers to the direction lying along the axis parallel to the insertion needle  106  that is further away from the subject when the catheter is inserted into the vein of the subject, opposite to the distal direction. 
     In one embodiment, the needle  106  can define a fluid conduit  114  extending between an inlet  116  positioned on the sharp distal tip  110  and an outlet  118  positioned on the radial wall  109 . In this embodiment, blood or bodily fluid can enter the fluid conduit  114  through the inlet  116  when the sharp distal tip  110  enters the vein. As blood flows proximally in the fluid conduit  114 , some of the blood passes through the outlet  118 . As depicted in  FIGS. 4A-B , in one embodiment, the insertion needle  106  can be a hollow hypodermic needle, wherein the inlet  116  of the fluid conduit  114  is in the distal opening of the hollow hypodermic needle, and the outlet  118  is a notch  120  defined by the radial wall  109  of the hollow hypodermic needle. Alternatively, as depicted in  FIGS. 5A-B , in one embodiment, the insertion needle  106  is a solid member defining a groove  122  positioned on the radial wall  109  representing the fluid conduit  114 , wherein the inlet  116  of the fluid conduit is defined by a distal end of the groove  124 , and the outlet  118  is defined by a proximal end of the groove  126 . 
     In some embodiments, the insertion needle  106  can further include a transition  128  that has a different cross-sectional size and/or shape then portions of the needle  106  positioned proximal to the transition  128 . The transition  128  (alternatively referred to as a needle bump or cannula bump) can be created by crimping opposed sides of the needle  106 , or otherwise disrupting the structure of the needle  106 , so that the outer surfaces of the needle  106  extend to a larger radial position than other portions of the needle  106 , as measured from the center of the needle axis. Transitions  128  can be formed differently, according to alternate embodiments, such as by adding material to the exterior of the needle, among other ways. 
     The proximal end  112  of the needle  106  can be operably coupled to the needle hub  108 . The needle hub  108  can be operably coupled to a needle grip  130 . In one embodiment, the needle grip  130  can be a flexible member including one or more living hinges  132 . The needle grip  130  can be fixedly coupled to the needle hub  108  at a proximal portion  134 , and can be translationally coupled to the needle hub  108  at a distal portion  136 . In one embodiment, portions of the needle grip  130  can be urged or brought together by the application of an external force thereby straightening a bend  138  formed in the needle grip  130 , thereby causing the distal portion  136  to shift distally relative to the needle hub  108 . In one embodiment, the distal shifting of the distal portion  136  can cause the catheter assembly  102  to shift distally relative to the catheter insertion device  104 . For example, in one embodiment, squeezing of the needle grip  130  can cause the catheter to distally advance 2-3 mm. 
     Referring to  FIG. 3 , in one embodiment, the catheter insertion device  102 ′ can provide a safety needle assembly, which functions to house the sharpened distal tip  110  of the insertion needle  106  to reduce the likelihood of an inadvertent needlestick.  FIG. 3  depicts the catheter insertion device  104  in a first, or ready for use position, in which the catheter assembly  102  is selectively coupled to the catheter insertion device  104 , with the sharp distal tip  110  of the insertion needle  106  protruding from a distal end of the catheter assembly  102 . 
     To insert the catheter assembly  102  into a vein of a patient or subject, a clinician first removes the intravenous catheter assembly  100 ′ from its packaging. In some cases, a needle sheath is removed to expose the sharp distal tip  110  of the insertion needle  106 . The clinician then punctures an identified site of the subject with the sharp distal tip  110  and urges and/or advances the needle  106  distally until the sharp distal tip  110  enters the vein of the subject. The catheter assembly  102  can then be moved distally over the needle by advancing an internal mechanism affixed to  140 , threading the catheter assembly  102  into the vein of the subject as the needle  106  is held stationary. With the catheter assembly  102  positioned as desired, the clinician can withdraw the needle  106  by continuing to advance  140  distally while holding the catheter assembly  102  generally stationary with respect to the subject. The needle assembly  140  can be advanced distally until the insertion needle  106  of the catheter insertion device  104  is separated from the catheter assembly  102  and safely housed within a needle housing  142  of the catheter insertion device  104 . In one embodiment, the catheter insertion device  104  can further include a removable blood sample collection vial  144 , configured to collect a sample of blood flowing through the lumen of the insertion needle  106 . 
     The catheter assembly  102  generally includes a catheter tube  146  and a catheter hub  148 . As depicted in  FIG. 3 , in one embodiment, the catheter assembly  102  can optionally include a wing assembly  150 . Further, in some embodiments, the catheter assembly  102  can include an extension tube, an extension tube clamp, a needleless connector, and a vent cap. Accordingly, the catheter assembly  102  can be a closed system catheter configured to inhibit blood from escaping after withdrawal of the needle  106 . 
     With additional reference to  FIGS. 4A-B , a partial, cross-sectional view of an insertion needle  106  and catheter tube  146  is depicted in accordance with an embodiment of the disclosure. As depicted, the catheter tube  146  is coaxially positioned over the insertion needle  106 . The catheter has a distal end  152 , a proximal end  154  and a flexible wall  156  defining a lumen extending therebetween. As depicted in  FIG. 4A , the catheter tube  146  is initially coaxially positioned over the insertion needle  106  in a first position, in which the sharp distal tip  110  extends beyond the distal end  152  of the catheter tube  146 . An annular space  158 A/B is defined between the radial wall  109  of the insertion needle  106  and the flexible wall  156  of the catheter tube  146 . In one embodiment, the annular space  158  is divided into a first axial chamber  158 A and a second axial chamber  158 B by a formed region  160  of the flexible wall  156 , wherein the formed region  160  has an internal diameter sized to approximate the outer diameter of the insertion needle  106 , such that flow of blood or bodily fluid between the first axial chamber  158 A and the second axial chamber  158 B along the annular space  158  is inhibited. In the initial position, the outlet  118  of the fluid conduit  114  is positioned within the first axial chamber  158 A, thereby providing a first visual indication during catheter insertion, by enabling blood from the vein of the patient to flow into the first axial chamber  158 A. 
     In one embodiment, the distal end  152  of the catheter tube  146  additionally includes a formed region  160  having an internal diameter sized to approximate the outer diameter of the insertion needle  106 . In some embodiments, the formed region  160  serves to minimize the diameter of the catheter tube  146  for ease of insertion of the catheter assembly  102  into the tissue of a patient. 
     As depicted in  FIG. 4B , the catheter tube  146  and insertion needle  106  can translate axially relative to one another to a second position during catheter insertion, such that the outlet  120  of the fluid conduit  114  is shifted from the first axial chamber  158 A to the second axial chamber  158 B, thereby providing a second visual indication during catheter insertion by enabling blood from the vein of the patient to flow into the second axial chamber  158 B. 
     Referring to  FIGS. 5A-B , a partial, cross-sectional view of an insertion needle  106 ′ and catheter tube  146  is depicted in accordance with another embodiment of the disclosure. As depicted in  FIG. 5A , the catheter tube  148  is initially coaxially positioned over the insertion needle  106 ′ in a first position, in which the sharp distal tip  110 ′ extends beyond the distal end  152  of the catheter tube  146 . An annular space  158  is defined between the radial wall  109 ′ of the insertion needle  106 ′ and the flexible wall  156  of the catheter tube  146 . In one embodiment, the annular space  158  is divided into a first axial chamber  158 A and a second axial chamber  158 B by a formed region  160  of the flexible wall  156 , wherein the formed region  160  has an internal diameter sized to approximate the outer diameter of the insertion needle  106 ′, such that flow of blood or bodily fluid between the first axial chamber  158 A and the second axial chamber  158 B along the annular space  158  is inhibited. In the initial position, the outlet  126  of the fluid channel  122  is positioned within the first axial chamber  158 A, thereby providing a first visual indication during catheter insertion, by enabling blood from the vein of the patient to flow into the first axial chamber  158 A. 
     As depicted in  FIG. 5B , the catheter tube  146  and insertion needle  106 ′ translate axially relative to one another to a second position during catheter insertion, such that the outlet  126  of the fluid channel  122  is shifted from the first axial chamber  158 A to the second axial chamber  158 B, thereby providing a second visual indication during catheter insertion by enabling blood from the vein of the patient to flow into the second axial chamber  158 B. 
     With additional references to  FIGS. 6A-C , insertion of the intravenous catheter assembly  100  into the vein of a patient, advancement of the catheter tube  146  over the insertion needle  106 , and threading of the catheter tube into the vein of the patient are depicted in accordance with an embodiment of the disclosure. Initially the catheter tube  146  is coaxially positioned over the insertion needle  106  in an initial position, in which the sharp distal tip  110  of the insertion needle  106  extends beyond a distal end  152  of the catheter. Often a tourniquet is applied proximal to the biological site and a variety of techniques can be used to dilate the patient&#39;s vein. While wearing disposable gloves, the clinician cleanses the biological site and a vein is retracted or anchored by placing a thumb over the vein about fifty to seventy-five mm distal to the site. 
     As depicted in  FIG. 6A , the sharp distal tip  110  of the needle  106  is introduced into the vein by inserting the bevel of the sharp distal tip  110  into the vein at about a twenty to thirty-degree angle with the bevel facing up in order to pierce one wall of the vein. In some embodiments, during this process the clinician grips the catheter insertion device  104  for optimum control. If successful, blood will flow through the fluid conduit  114  and into the first axial chamber  158 A, thereby providing a positive indication that the sharp distal tip  110  of the needle  106  is positioned within the vein of a patient. 
     As depicted in  FIG. 6B , to finish placement, the intravenous catheter assembly  100  is lowered towards the skin to decrease the entry angle. The clinician then begins to advance the catheter assembly  102  over the insertion needle  106 . Once the catheter assembly  102  has been advanced, the clinician may withdraw the insertion needle  106 . In some cases, the advance of the catheter assembly  102  and the withdrawal of the insertion needle  106  occur simultaneously. 
     As depicted in  FIG. 6C , once the outlet  118  of the fluid conduit  114  shifts from the first axial chamber  158 A to the second axial chamber  158 B, blood flows through the fluid conduit  114  and into the second axial chamber  158 B, thereby providing a positive indication that the catheter tube  146  is positioned within the vein of a patient. Accordingly, embodiments of the present disclosure provide a two-stage flash to first serve as an aid in ensuring that the needle  106  has entered into the vein of the patient, and second to serve as an aid to ensure that the catheter tube  146  is being properly threaded into the vein of the patient, while the catheter tube  146  is being inserted. 
     The clinician can then secure the catheter assembly  102  in place by securing the catheter hub  148  and/or wing assembly  150  to the biological site by gauze and adhesive tape. The catheter assembly  102  can then be connected to an IV fluid supply configured to supply medicament to the patient, or withdraw fluid from the patient. 
     Referring to  FIGS. 7A-C , an alternative embodiment of an intravenous catheter assembly  200  is depicted. In this embodiment, the insertion needle  206  can define a fluid conduit  214  including an inlet  216 , a first outlet  218 A, and a second outlet  218 B. As depicted in  FIG. 7A , initially the catheter tube  246  is coaxially positioned over the insertion needle  206  in an initial position, in which the sharp distal tip  210  of the insertion needle  206  extends beyond a distal end  252  of the catheter. 
     As depicted in  FIG. 7B , when the sharp distal tip  210  of the needle  206  is introduced into the vein, blood flows through the fluid conduit  214  to the respective first and second outlets  218 A/B. In some embodiments, the catheter tube  246  can be constructed of a transparent or translucent material, such that a clinician can observe blood present at the first outlet  218 A, thereby providing a positive indication that the sharp distal tip  210  of the needle  216  is positioned within the vein of a patient. 
     In some embodiments, the catheter tube  246  can include a secondary confirmation chamber  262 . For example, in one embodiment, the secondary confirmation chamber  262  can form a cavity or annular space into which blood from the patient can flow. As depicted in  FIG. 7C , once the second outlet  218 B shifts from the initial position into fluid communication with the secondary confirmation chamber, blood flows through the conduit  214  and into the secondary confirmation chamber  262  thereby providing a positive indication that the catheter tube  246  is positioned within the vein of a patient. Accordingly, embodiments of the present disclosure provide a two-stage flash to first serve as an aid in ensuring that the needle  206  has entered into the vein of the patient, and second to serve as an aid to ensure that the catheter tube  246  is being properly threaded into the vein of the patient, while the catheter tube  246  is being inserted. 
     It should be understood that the individual steps used in the methods of the present teachings may be performed in any order and/or simultaneously, as long as the teaching remains operable. Furthermore, it should be understood that the apparatus and methods of the present teachings can include any number, or all, of the described embodiments, as long as the teaching remains operable. 
     Various example intravenous catheter assembly embodiments are described herein for use in accessing the vein of the subject. It is to be appreciated, however, that the example embodiments described herein can alternatively be used to access the vasculature of a subject in locations other than the vein, including but not limited to the artery of the subject. It is additionally to be appreciated that the term “clinician” refers to any individual that can perform a catheter insertion procedure with any of the example embodiments described herein or combinations thereof. Similarly, the term “subject,” as used herein, is to be understood to refer to an individual or object in which a catheter is to be inserted, whether human, animal, or inanimate. Various descriptions are made herein, for the sake of convenience, with respect to procedures being performed by a clinician to access the vein of the subject, while the disclosure is not limited in this respect. 
     Persons of ordinary skill in the relevant arts will recognize that embodiments may comprise fewer features than illustrated in any individual embodiment described above. The embodiments described herein are not meant to be an exhaustive presentation of the ways in which the various features may be combined. Accordingly, the embodiments are not mutually exclusive combinations of features; rather, embodiments can comprise a combination of different individual features selected from different individual embodiments, as understood by persons of ordinary skill in the art. Moreover, elements described with respect to one embodiment can be implemented in other embodiments even when not described in such embodiments unless otherwise noted. Although a dependent claim may refer in the claims to a specific combination with one or more other claims, other embodiments can also include a combination of the dependent claim with the subject matter of each other dependent claim or a combination of one or more features with other dependent or independent claims. Such combinations are proposed herein unless it is stated that a specific combination is not intended. Furthermore, it is intended also to include features of a claim in any other independent claim even if this claim is not directly made dependent to the independent claim. 
     Moreover, reference in the specification to “one embodiment,” “an embodiment,” or “some embodiments” means that a particular feature, structure, or characteristic, described in connection with the embodiment, is included in at least one embodiment of the teaching. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment. 
     Any incorporation by reference of documents above is limited such that no subject matter is incorporated that is contrary to the explicit disclosure herein. Any incorporation by reference of documents above is further limited such that no claims included in the documents are incorporated by reference herein. Any incorporation by reference of documents above is yet further limited such that any definitions provided in the documents are not incorporated by reference herein unless expressly included herein. 
     For purposes of interpreting the claims, it is expressly intended that the provisions of 35 U.S.C. § 112(f) are not to be invoked unless the specific terms “means for” or “step for” are recited in a claim.