Patent Publication Number: US-2023144638-A1

Title: Low profile catheter system

Description:
PRIORITY 
     This application is a continuation of and claims priority from co-pending U.S. application Ser. No. 16/864,374, filed May 1, 2020, entitled “Low Profile Catheter System,” assigned attorney docket number 130974-21302, and naming Todd Chelak, Ian Kimball, Luis Maseda and Jonathan Gabel as inventors, the disclosure of which is incorporated herein, in its entirety, by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates to vascular access sites, and more particularly to low profile catheter systems that allow a user to easily connect and disconnect from a catheter inserted into a patient&#39;s vasculature. 
     BACKGROUND ART 
     In instances in which a patient will need regular administration of fluid or medications (or regular withdrawal of fluids/blood), catheters are often inserted into the patient and used to administer the fluids/medications. The catheter may remain in the patient for extended periods of time (several hours to several days or longer). Additionally, an extension tube may be connected to the catheter to facilitate use of the catheter and connection of a medical implement (e.g., a syringe). To ensure that the catheter and/or extension tube remain in place and are not accidentally removed, some prior art systems secure the catheter and/or extension tube to the patient using tape or similar adhesive materials (e.g., a film dressing). 
     Typical peripheral IV Catheters in the market today possess inlet hubs that utilize ISO 80369-7 Luer connections. These tubular connections are cumbersome for the user to manipulate (often leading to incomplete connections), and they force undesirable profiles that create snag hazards. Additionally, the associated components are uncomfortable pressure points when resting on the skin of patients during the episode of care. 
     SUMMARY OF THE INVENTION 
     In accordance with one embodiment of the invention, a low profile catheter system may include a catheter hub, a base connector and a biasing member. The catheter hub may have a proximal end, a distal end and a stabilization surface located on an underside of the catheter hub. The stabilization surface may stabilize the catheter hub on a patient. The catheter hub may also have a substantially linear flow path extending from an opening at the distal end to an inlet located within an intermediate portion of the catheter hub. The flow path may allow fluid to flow between the distal end and the intermediate portion of the catheter hub, and the inlet may be located between the proximal end and the distal end of the catheter hub. The base connector may have a fluid path extending through at least a portion of the base connector, and the intermediate portion of the catheter hub may receive the base connector. The fluid path may have a first opening and may be fluidly connected to the inlet of the flow path in the catheter hub when the base connector is received by the intermediate portion of the catheter hub. The biasing member may bias the first opening of the fluid path toward the inlet when the base connector is received by the intermediate portion of the catheter hub. 
     In some embodiments, the catheter system may also include a catheter that is at least partially secured within and extending into the flow path. At least a portion of the underside may include a flat surface, and the catheter may have a longitudinal axis that is oriented at an angle with respect to the flat surface. Additionally or alternatively, the system may include an introducer that is removably connectable with the catheter hub when the base connector is not connected. The introducer may have a handle and a needle configured to extend through the flow path and catheter when the introducer is connected. 
     In accordance with further embodiments, the catheter hub may have a fluid seal interface around the inlet of the flow path, and the biasing member may axially bias the first opening of the fluid path toward the fluid seal interface. Additionally or alternatively, the base connector may include a sealing member located at the first opening. The sealing member may seal against the fluid seal interface when axially biased toward the fluid seal interface. The biasing member may be located on the catheter hub. 
     The low profile catheter system may also include a first retention feature located on the catheter hub and a second retention feature located on the base connector. The first and second retention features may interact with one another to secure the base connector to the catheter hub when the base connector is received by the intermediate portion of the catheter hub. In some embodiments, the catheter hub may have a recess located within a top surface of the catheter hub and at least within the intermediate portion. The recess may be configured to receive at least a portion of the base connector. The catheter hub may also have at least one indent and the base connector may include at least one projection extending from it. The projection(s) may enter the indent(s) in the catheter hub upon receiving the base connector to align the base connector within the catheter hub. The catheter hub may include least one slot extending through it to provide access to the patient&#39;s skin. 
     In accordance with additional embodiments, the base connector may include a valve mechanism (e.g., a two-way pressure activated valve) that controls fluid flow through the fluid path. A bottom surface of the base connector may include a recess that, in turn, houses at least one sensor. To help stabilize and/or secure the catheter hub to/on the patient, the system may include an adhesive layer located on the stabilization surface. The catheter hub may have at least one projection that extends from a surface of the catheter hub and the base connector may have at least one recess. The projection(s) may enter the recess(es) when the base connector is received by the catheter hub to secure the base connector to the catheter hub. 
     In some embodiments, the system may include a tube connected to a second opening of the fluid path and/or a dressing secured to the base connector. The dressing may be configured to secure the catheter system to the patient. For example, the dressing may include a patch layer secured to a top surface of the base connector, and the patch layer may have a securement portion extending beyond the top surface of the base connector that adheres to the patient. The dressing may also have a first, second and third film layer. The first film layer may be located at least partially on the patch layer and may have an opening nearer a first end of the first film layer. The second film layer may be located on the first film layer and may have a channel extending along at least a portion of its length. The third film later may be located on the second film layer. The first, second and third film layers, the opening in the first film layer, and the channel may form a fluid pathway that is in fluid communication with the fluid path within the base connector. 
     In accordance with further embodiments of the present invention, a method for transferring fluid to and/or from a patient includes providing a low profile catheter system that has a catheter hub, a base connector, and a biasing member. The catheter hub may have a proximal end, a distal end and a stabilization surface located on an underside of the catheter hub. The catheter hub may also have a substantially linear flow path extending from an opening at the distal end to an inlet located within an intermediate portion of the catheter hub. The flow path may allow fluid to flow between the distal end and the intermediate portion of the catheter hub. The inlet may be located between the proximal end and the distal end of the catheter hub. The base connector may have a fluid path extending through at least a portion of it, and the intermediate portion of the catheter hub may receive the base connector. The fluid path has a first opening and may be fluidly connected to the inlet of the flow path in the catheter hub when the base connector is received by the intermediate portion of the catheter hub. The biasing member may bias the first opening of the fluid path toward the inlet when the base connector is received by the intermediate portion of the catheter hub. 
     The method may also include fluidly connecting the flow path within the catheter hub with the patient&#39;s vasculature and placing the catheter hub on the patient such that the stabilization surface stabilizes the catheter hub on the patient. The method may then connect the base connector to the catheter hub such that the intermediate portion of the catheter hub receives the base connector. The biasing member may then bias the first opening of the fluid path toward the inlet to fluidly connect to the flow path and the fluid path when the base connector is received by the intermediate portion of the catheter hub. The method may then transfer fluid to and/or from the patient through the flow path and the fluid path. 
     In some embodiments, the catheter hub may include a catheter at least partially secured within and extending into the flow path, and fluidly connecting the fluid path with the patient&#39;s vasculature and may include inserting the catheter into the patient&#39;s vasculature. For example, fluidly connecting the fluid path with the patient&#39;s vasculature may include connecting an introducer to the catheter hub prior to connecting the base connector. The introducer may have a needle that extends through the flow path and the catheter when the introducer is connected. The method may then insert the needle into the patient&#39;s vasculature, thereby inserting the catheter into the patient&#39;s vasculature, and disconnect the introducer from the catheter hub. 
     The catheter hub may have a fluid seal interface around the inlet of the flow path, and the biasing member may axially bias the first opening of the fluid path toward the fluid seal interface. Additionally or alternatively, the base connector may have a sealing member located at the first opening. The sealing member may seal against the fluid seal interface when axially biased toward the fluid seal interface. To secure the base connector to the catheter hub, the catheter hub may have a first retention feature and the base connector may have a second retention. The first and second retention feature may interact with one another to secure the base connector to the catheter hub when the base connector is received by the intermediate portion of the catheter hub. To receive at least a portion of the base connector, the catheter hub may have a recess located within a top surface within the intermediate portion. 
     In other embodiments, the catheter hub may also have at least one indent and the base connector may have at least one projection extending from it. In such embodiments, connecting the base connector to the catheter hub may include inserting the projection(s) into indent(s) in the catheter hub. The base connector may have a valve mechanism that controls fluid flow through the fluid path. The system may have an adhesive layer located on the stabilization surface to secure the catheter hub to the patient when the catheter hub is placed on the patient and/or a dressing secured to the base connector. The method may then apply the dressing to the patient to secure the catheter system to the patient. The dressing may include a film based fluid pathway fluidly connected to the fluid path. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing features of embodiments will be more readily understood by reference to the following detailed description, taken with reference to the accompanying drawings, in which: 
         FIG.  1    schematically shows a perspective view of a low profile catheter system, in accordance with some embodiments of the present invention. 
         FIG.  2    schematically shows the low profile catheter system of  FIG.  1    with a base connector disconnected from a catheter hub, in accordance with various embodiments of the present invention. 
         FIG.  3    schematically shows a perspective view of the catheter hub, in accordance with some embodiments of the present invention. 
         FIGS.  4 - 7    schematically show back, top, side and front views of the catheter hub shown in  FIG.  3   , in accordance with various embodiments of the present invention. 
         FIG.  8    schematically shows a perspective view of the base connector, in accordance with some embodiments of the present invention. 
         FIGS.  9 - 11    schematically show a bottom, top and exploded view of an alternative base connector with a dressing portion and film based fluid pathway, in accordance with some embodiments of the present invention. 
         FIG.  12    schematically shows an alternative embodiment of the base connector with a dressing and a tube, in accordance with various embodiments of the present invention. 
         FIGS.  13 - 14    schematically show a cross sectional view and cross sectional close-up view of the catheter system with the base connector connected to the catheter hub, in accordance with various embodiments of the present invention. 
         FIGS.  15 - 16    schematically show a bottom view and a top view of the catheter system with the base connector connected to the catheter hub, in accordance with various embodiments of the present invention. 
         FIG.  17    schematically shows an introducer used to insert the catheter into the patient&#39;s vasculature, in accordance with some embodiments of the present invention. 
         FIGS.  18  and  19    schematically show various views of the introducer connected to the catheter hub, in accordance with some embodiments of the present invention. 
         FIG.  20    schematically shows a cross-sectional view of the introducer connected to the catheter hub, in accordance with various embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS 
     In illustrative embodiments, a low profile catheter system includes a catheter hub with a stabilization surface that stabilizes the system on the patient and a linear flow path extending through a portion of the catheter hub. The flow path allows fluid to flow between a distal end and an intermediate portion of the catheter hub. The intermediate portion of the catheter hub may receive a base connector having a fluid path extending through a portion of it. When the connector is received by the catheter hub, an opening of the fluid path is fluidly connected to the inlet of the flow path in the catheter hub and a biasing member biases the first opening of the fluid path toward the inlet. Details of illustrative embodiments are discussed in greater detail below. 
       FIGS.  1  and  2    schematically show a low profile catheter system  100  that includes a catheter hub  200  and a base connector  500  that may be connected to (e.g., received by) the catheter hub  200  ( FIG.  1   ) and disconnected/removed from the catheter hub  200  ( FIG.  2   ). As discussed in greater detail below, the catheter hub  200  may include a catheter  210  that may be inserted into the patient&#39;s vasculature (e.g., into a vein of the patient). When the base connector  500  is connected to the catheter hub  200 , a user can transfer fluids to and/or from a patient, even in high pressure applications. 
     As shown in  FIGS.  3 - 7   , the catheter hub  200  has a hub body  220  with a proximal end  230 , a distal end  240  and an intermediate portion  250  located between the proximal end  230  and the distal end  240 . Extending through a portion of the hub body  220  (e.g., between the distal end  240  and the intermediate portion  250 ), the catheter hub  200  may have a flow path  260  (e.g., a linear flow path) that allows fluid to flow through the catheter hub  200 . To stabilize the catheter hub  200  (and the catheter system  100 ) on the patient, the catheter hub  200  may have a stabilization surface  270  located on an underside of the hub body  220 . To help secure the device  100  to the patient, the stabilization surface  270  may have an adhesive layer (not shown) that adheres the catheter hub  200  to the patient. 
     The intermediate portion  250  of the catheter hub  200  may include a recess  252  that receives the base connector  500  during connection of the base connector  500  and the catheter hub  200 . To help align the base connector  500  within the catheter hub  200 , the catheter hub  200  (e.g., the intermediate portion  250 ) may have one or more indents  254  that receive one or more guidance tabs  520  extending from the body  510  of the base connector  500  (discussed in greater detail below). Additionally, to secure the base connector  500  within the intermediate portion  250  of the catheter hub  200 , the catheter hub  200  may have one or more snap tabs  280  that extend into the recess of the intermediate portion  250  and enter a snap retention feature  530  (e.g., a snap recess) within the base connector  200 . Alternatively, the base connector  200  may have one or more snap tabs that enter retention features on the catheter hub during connection. It should be noted that although two snap tabs  280  and two retention features  530  are shown, other embodiments may have more or less snap tabs and retention features and/or the catheter hub  200  and base connector  500  may each have both snap tabs and retention features. 
     As best shown in  FIGS.  3  and  4   , the catheter  210  may extend either partially or entirely through and may be secured within the flow path  260 . Additionally or alternatively, to minimize the pressure/force/strain on the insertion site of the patient and preserve the insertion angle of the catheter  210 , the flow path  260  and/or the catheter  210  may be oriented at an angle with respect to the catheter hub  200 . For example, the catheter hub  200  may have a flat surface  290  located on a top and/or bottom surface and the longitudinal axis of the catheter  210  and/or the flow path  260  may be oriented at an angle (e.g., 7 degrees) with respect to the flat surface  290 . 
     As discussed in greater detail below, the flow path  260  within the catheter hub  200  fluidly connects to a fluid path  540  within the base connector  500  when the base connecter  500  is connected. To that end, the catheter hub  200  may include a fluid seal interface  300  located around the inlet  262  of the flow path and against which the fluid path  540  within the base connector and/or a sealing element  550  within the base connector  500  may seal. The fluid seal interface  300  may be a surface on the intermediate portion  250  or it may be a flared portion  212  of the catheter  210  ( FIGS.  13  and  14   ). Additionally, to ensure a tight seal between the fluid path  540 /sealing element  550  and the fluid seal interface  300 , the catheter hub  200  may include a biasing element  310  that contacts the base connector  500  when connected and biases the base connector  500  toward the distal end  240  and the first opening  542  toward the fluid seal interface  300 . For example, the biasing element  310  may be a curved stepped feature that creates longitudinal dimensional interference with base connector  500  thereby pushing the base connector  500  toward the distal end  240  of the hub  200  while intermediate portion  250  flexes to receive base connector  500  and/or fluid seal interface  300  and/or sealing element  550  compresses. Alternatively, the hub  200  may be at least partially an elastomeric member that stretches open to receive the base connector  500 . In such embodiments, the elastomeric nature of the rear wall of the hub  200  (e.g., the wall at the proximal end  230 ) will bias the base connector  500  toward the distal end  240 . 
     As noted above and as shown in  FIG.  8   , the base connector  500  may have one or more projections or guidance tabs  520  extending from the connector body  510  that help align the base connector  500  within the catheter hub  200  during connection. It should be noted that, in addition to performing this guidance/alignment function, the projections  520  may also help to prevent contamination of the sealing element  550  (e.g., an O-ring) and/or the opening  542  of the fluid path  540 . For example, because these projections  520  extend out further than the sealing element  550  and extend beyond the opening  542 , the projections  520  will prevent contamination if the user accidentally bumps the base connector  500  against a surface (e.g., because the projections  520  will prevent the sealing element  550  and/or the opening  542  from contacting the surface). 
     To help secure the catheter system  100  to the patient and help protect the catheter insertion site (e.g., by providing and environmental barrier), the base connector  500  may have a dressing  570  (e.g., a patch) secured to the body  510  of the base connector  500  (e.g., via adhesive, ultrasonic welding, RF welding, laser welding or similar securement method). As shown in  FIGS.  9 - 11   , the dressing  570  may include a number of layers. For example, the dressing  570  may include a patch layer  572  that includes an adhesive located on an underside of the patch layer  572 , a dressing frame  574  that provides some structural rigidity to the dressing  570 , and a release liner  576  that covers and protects the adhesive on the patch layer  572  prior to use. The patch layer  572  may have a securement portion  571  that extends beyond the base connector  500  and contacts the skin of the patient to secure the dressing  570  and device  100  to the patient. The patch layer  572  may include an opening  573  that provides access to the fluid path  540  in the base connector  500 . During use, the user may remove the release liner  576  to expose the adhesive on the patch layer  572 , grasp the dressing  570  by the dressing frame  574  (e.g., tabs on the dressing frame  574 ) and may position the dressing over the catheter insertion site, causing the adhesive and the securement portion  571  to adhere to the skin. 
     The bottom surface of the base connector  500  may include one or more recesses  590  that house sensors, electronics, or other technologies that may be used to sense, analyze or detect a characteristic of a patient. Alternatively, the electronics/sensors may be printed directly onto the bottom surface of the base connector  500 . In such embodiments, the intermediate portion  250  of the catheter hub  200  may have one or more corresponding openings in the recess  252  to provide access to the patient&#39;s skin. In addition to providing the sensors/electronics access to the skin, these openings may also help to facilitate skin moisture transmission. 
     To facilitate fluid flow through the catheter system  100 , the base connector  500  may include and/or may be connected to any number of extension sets, tubes, or fluid transfer devices. For example, the base connector  500  (e.g., the second opening  544  of the fluid path  540  through the base connector) may include or be connected to a film based fluid pathway/extension set  600  ( FIGS.  9 - 11   ) or a standard/tube based extension set  700  ( FIG.  12   ) or a female luer connector (not shown). For the standard/tube based extension set  700 , one end of the tube  710  may be fluidly connected to/secured to the fluid path at the second opening  544  and fluid may be transferred to and/or from the patient via the tube  710 , the fluid path  540  through the base connector  500 , the flow path  260  through the catheter hub  200 , and the catheter  210 . 
     As the name suggests, the film based fluid path  600  may be formed from multiple layers of film that define a fluid path extending through at least a portion of the layers. For example, the film based fluid path  600  may have a lower layer  610 , a middle layer  620  and a top layer  630 . The lower layer  610  has an opening  612  at one end and that is aligned with the second opening  544  in the fluid path  540  within the base connector  500  (e.g., to create fluid communication between the fluid path  540  and the film based fluid path  600 ). The middle layer  620  has a channel  622  extending along a portion of its length and the top/upper layer  630  is located on the middle layer  620  and covers the channel  622 . During fluid transfer to the patient, the fluid may pass through the channel  622  and the opening  612  and into the fluid path  540  within the base connector  500 . Conversely during transfer of fluid from the patient, fluid may flow from the fluid path  540  in the base connector  500 , through the opening  612  and into the channel  622 . 
     Although a film based extension set/fluid path way and a standard extension set/tube are shown and discussed above, other embodiments may be connected to other extension sets. For example, the base connector may be connected to a sensing extension set, a bifurcated extension set, a medical article extension set, or any other type of extension set. Additionally, although the Figures show the tube  700  and film based fluid pathway  600  in conjunction with the dressing  570 , other embodiments may have the dressing without the tube  700  and film based fluid pathway  600  or the tube  700  and film based fluid pathway  600  without the dressing  570  (e.g., the film based fluid pathway  600  may be part of or independent from the dressing  570 ). 
       FIGS.  13  and  14    schematically show cross-sectional views of the catheter hub  200  and the base connector  500  (with a film based fluid path  600 ) when the base connector  500  is connected. As can be seen, when the base connector  600  is located within the intermediate portion  250  of the catheter hub  200 , the biasing member/element  310  biases the base connector  500  toward the distal end  240  of the catheter hub  200 . This, in turn, biases the first opening  542  of the base connector fluid path  540  toward the inlet  262  of the catheter hub flow path  260  and seals the sealing element  550  against the fluid seal interface  300  and/or the flanged portion  212  of the catheter  210 . In embodiments in which the sealing member  580  seals against the flanged portion  212  of the catheter  210 , the catheter hub  200  (e.g., the body  210 ) may be isolated from the fluid passing through the device  100  (i.e. the material(s) used to construct the catheter hub  200  are not in contact with the fluid). 
     To help prevent retrograde blood flow through the catheter system  100 , the system  100  may include a valve mechanism  580  that selectively allows and prevent fluid flow through the device  100 . For example, as shown in  FIG.  14   , the base connector  500  may include a two way pressure activated valve  580  (e.g., a slit diaphragm type structure) located within the fluid path  540  or adjacent the first opening  542 . In the presence of a large enough pressure (e.g., above the retrograde venous pressure of the patient in a reverse direction and/or above a smaller pressure in a forward direction), the valve  580  will open to allow fluid flow through the device  100 . In some embodiments, the valve  580  may be integral with the sealing member  550 . Alternatively, the base connector  500  may not have a separate sealing member  550  and the valve  580  may act as the sealing member (e.g., the valve  580  may seal against the fluid seal interface  300 ). 
     In some embodiments, an introducer  800  may be used to insert the catheter  210  into the patient&#39;s vein. As shown in  FIGS.  17 - 20   , the introducer  800  may have an introducer body  810  (e.g., a handle) and one or more jaw members  820  that may move relative to the body  810  (e.g., from a first position to a second position), for example, about a hinge  822 . Each of the jaw members  820  may be sized and shaped to be received by the intermediate portion  250  and the indents  254  of the catheter hub  200  and may have a snap retention feature  824  to receive the snap tabs  280  located on the catheter hub  200 . The introducer  800  also includes a needle  830  that is sized to extend through the flow path  260  in the catheter hub  200  and/or the catheter  210 . 
     To that end and to connect the introducer  800  to the catheter hub  200 , the manufacturer may insert the tip of the needle  830  into the inlet  262  of the flow path  260  and the catheter  210  and then press the jaw members  820  into the intermediate portion  250  causing the jaw members  820  to enter the indents  254 , the snap tabs  280  to enter the snap retention features  824 , and the needle to extend through the remainder of the flow path  260  and catheter  210  ( FIG.  18 - 20   ). When the introducer  800  is connected to the catheter hub  200 , the user may now insert the needle  830  into the patient&#39;s vein and place the stabilization surface  270  on the patient. If equipped, the user may then use the adhesive on the stabilization surface  270  to secure the catheter hub  200  to the patient. 
     Once the hub  200  is in place and the catheter  210  is in the vein, the user may press inward on the jaw members  820  to release them from the snap tabs  280  and may disconnect the introducer  800  from the catheter hub  200 . As the user disconnects the introducer  800 , the needle  830  will be removed from the catheter  210 , leaving the catheter  210  in place in the vein. In some embodiments, the catheter hub  200  may be equipped with a needle protection cover (e.g., a stainless steel stamped element) that captures the needle tip and disengages from the catheter hub  200  for safe sharps disposal. 
     After removal of the introducer  800 , the base connector  500  may be connected to the catheter hub  200  as discussed above to fluidly connect the fluid path  540  within the base connector  500  to the flow path  260  and catheter  210  in the catheter hub  200 . If the system  100  has a dressing  570 , the user may remove the release liner  576  and secure the patch layer  572  (e.g., the securement portion  573  to the patient). The user may then transfer fluid to and/or from the patient via the catheter system  100 . 
     It should be noted that various embodiments of the present invention provide numerous benefits over prior art catheter systems. For example, because the base connector  500  easily connects to the catheter hub  200  by essentially snapping it in place, there is no rotation between the connector and the catheter. This, in turn, eliminates undesirable rotation of any stabilizing structures (e.g., the structures that stabilize the device on the patient), allows the device to sit flat on the patient, and is more comfortable for the patient. 
     The embodiments of the invention described above are intended to be merely exemplary; numerous variations and modifications will be apparent to those skilled in the art. All such variations and modifications are intended to be within the scope of the present invention as defined in any appended claims.