Abstract:
The present disclosure relates to a catheter insertion device, which comprises a catheter hub in which a check valve is arranged, and a catheter, which is in fluid communication with the catheter hub, wherein a support element is attached to the catheter, and a flexible buffer element is provided between the support element and the catheter hub.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a national phase application under 35 U.S.C. §371 of PCT Application No. PCT/EP2010/006018 filed Oct. 1, 2010, which claims the benefit of German application No. 20 2009 013 213 7 filed Oct. 1, 2009, the contents of each of which are expressly incorporated herein by reference. 
     
    
     FIELD OF ART 
       [0002]    The present disclosure relates to a catheter insertion device in whose catheter hub a check valve is provided, which prevents the leakage of blood from the catheter hub when the catheter is inserted into the vein of a patient and the needle is removed from the catheter hub. 
       BACKGROUND 
       [0003]    From WO 2004/004819 (FIGS. 1 and 2), such a catheter insertion device is known, having a catheter hub at whose distal end a catheter is attached and in which a check valve is arranged, through which the needle extends in the ready position, wherein the needle tip protrudes distally from the catheter. After retracting the needle out of the catheter hub, the check valve closes automatically, whereupon for example an IV line is attached to the catheter hub so that after opening of the check valve an IV fluid can be introduced into the vein of the patient. Hereby, for example by means of a valve actuation element, the check valve can be opened by pressure in the distal direction. This pressure is transferred to the catheter inserted in the vein of the patient, so that above all in the case of the valve being repeatedly opened and of the related handling of the relatively bulky catheter hub, mechanically induced phlebitis can occur in the patient. 
         [0004]    Furthermore, during handling of the catheter insertion device, the problem frequently occurs of the catheter becoming bent. This problem of becoming bent occurs, for example, when the catheter hub is fixed on the skin of the patient, as illustrated by means of  FIG. 9 . By becoming bent, the catheter becomes unusable and has to be removed, whereupon a new catheter has to be inserted. 
       SUMMARY 
       [0005]    By means of the present disclosure, a catheter insertion device is to be provided, by means of which handling is improved with regard to protection from becoming bent, and mechanically induced phlebitis can be prevented even when, for treating the patient, the valve in the catheter hub has to be repeatedly opened by pressure in the distal direction. 
         [0006]    According to the present method, system and device, a support element for the catheter on the skin of the patient is provided between the distal end of the catheter and the catheter hub, and a flexible buffer element is provided between the support element and the catheter hub, especially as an easily deformable, flexible hose line, so that on opening the check valve, forces occurring at the catheter hub are absorbed by the deformation of this flexible hose line and the remaining forces are absorbed by the support element on the skin of the patient, so that no movements are induced at the distal end portion of the catheter positioned in the vein when the check valve in the catheter hub is opened. 
         [0007]    Protection from becoming bent is achieved by means of the flexible buffer element or by means of the flexible hose line between the support element and the catheter hub, in that a possible bend occurs in the area of this flexible hose line, which can be bent straight again, so that no damage occurs to the catheter itself and the uninterrupted passage of the fluid is guaranteed. 
         [0008]    Preferably, the flexible and easily deformable hose line is formed between the catheter hub and the support element, independently of the catheter, which extends between the support element and the distal end. 
         [0009]    Further aims, advantages, features and application options of the present method, system and device follow from the following description of the embodiments with reference to the drawings. Hereby, all the features described and/or represented by the drawing form the subject matter of the present method, system and device in themselves or in any meaningful combination, independently of their summary in the claims and the back-references thereof. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0010]    Exemplary embodiments of the present method, system and device are explained in more detail below with reference to the drawings, in which: 
           [0011]      FIG. 1  shows a catheter insertion device of the known type, 
           [0012]      FIG. 2  shows the insertion of a syringe in the known catheter hub, 
           [0013]      FIG. 3  shows in section an embodiment according to the present method, system and device having a support element, 
           [0014]      FIG. 4  shows an embodiment having wings on the support element, 
           [0015]      FIG. 5  shows an embodiment having a valve opener in the catheter hub, 
           [0016]      FIG. 6  shows an embodiment having a valve opener and a needle guard element, 
           [0017]      FIG. 7  shows an embodiment having a needle guard element in the catheter hub, 
           [0018]      FIG. 8  shows an embodiment in which the needle is provided with an extraction wire, 
           [0019]      FIG. 9  shows possible bending of the catheter during handling, and 
           [0020]      FIG. 10  shows a modified embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    The known catheter insertion device  1  in  FIGS. 1 and 2  has a two-part catheter hub  5 , wherein between the two elements  5 . 1  and  5 . 2  of the catheter hub  5 , a disc-shaped check valve  7  is held, which for example has slits starting radially from the middle, through which the needle  9  extends in the ready position ( FIG. 1 ), wherein the needle is held in the needle hub  8 . The tip  9   a  of the needle  9  protrudes over the distal end of the catheter  4  in the ready position. As  FIG. 1   a  shows, a stopper  8   a  which catches blood is usually provided at the end of the needle hub  8 . The stopper which catches blood is provided with a membrane being air-permeable but not blood-permeable. In the catheter hub  5 , a valve actuation element  10  is arranged having an approximately truncated cone-shaped front part  10   a  and two diametrically opposite stays  10   b . Between these stays, in the ready position, a needle guard element  13  is located which, by means of the removal of the needle  9  from the catheter hub  5  is removed from the catheter hub  5  and covers the needle tip, after a crimp  9 . 1  on the needle (shown in  FIG. 7 ) has engaged the proximal rear wall of the needle guard element  13 . At  5   a,  a stop is shown for the valve actuating element  10  which is displaceable in the catheter hub. At  6 , a Luer thread is indicated. 
         [0022]      FIG. 2  shows the insertion of a syringe  14  in the catheter hub  5 , wherein a distal hub  14   a  displaces the valve actuation element  10  in the catheter hub forwards and opens the valve  7 , whose deformed flaps between the slits are designated by  7   b.  It is obvious that when inserting the syringe  14  in the catheter hub  5 , a force P acting in the distal direction is exerted on the catheter hub  5  and thus on the catheter  4 , which consists of relatively rigid material. During handling of the catheter hub  5 , which is relatively bulky due to the integrated check valve  7 , moments of torsion can also be exerted on the catheter  4 , by which irritation at the vein is increased. 
         [0023]      FIG. 3  schematically shows an embodiment according to the present method, system and device having a support element  20 , which has an approximately tubular main body  20 . 1  with a support area  20 . 2  for abutting of the support element  20  on the skin of the patient. The support element  20  is formed flat and only slightly higher than the hose line  40 . Because the support element  20  is formed very flat, it can hardly be unintentionally jolted, as in the case for the relatively high catheter hub. The catheter  4  is fixed in the support element  20  preferably by means of a metal or plastic hub  21 , wherein the catheter consists of a relatively rigid material, usually of fluorinated ethylene propylene (FEP), in other words Teflon. On the proximal side of the support element  20 , between the catheter hub  5  and the support element a flexible and easily deformable hose line  40  is provided, which is fixed to the tubular main body  20 . 1  of the support element  20  by heat-sealing or by means of solvent bonding, if both the support element  20  and the flexible hose line  40  consist of the same soft material. At the catheter hub  5 , the flexible hose line  40  can expediently be fixed by means of a metal or plastic hub  3 , which has a funnel-shaped hub. The flexible hose line  40  and the support element  20  are preferably manufactured from soft PVC or soft polyurethane. The catheter hub  5  preferably consists of a more rigid polypropylene. 
         [0024]    If the flexible hose line  40  and the support element  20  consist of the same soft material, the hose line  40  can also be moulded onto the support element  20 . This allows the support element  20  to be formed just as high as the hose line  40 . 
         [0025]    The flexible, easily deformable hose line  40  forms a buffer element between support element  20  and catheter hub  5  for receiving the forces occurring at the catheter hub  5  during handling, when an IV line is to be attached to the catheter hub  5  or a syringe is to be inserted in the catheter hub. Hereby, both forces in the axial direction can occur at the catheter hub  5 , as indicated by an arrow P, and torsional moments can occur, which are absorbed by the buffer element in the form of the flexible hose line  40 , so that at the distal end of the catheter  4 , no mechanically induced irritations occur in the vein of the patient. 
         [0026]    The flexible hose line  40  can also extend only over a certain portion or only partly between the support element  20  and the catheter hub  5 . 
         [0027]    As the catheter  4  is usually formed very thin-walled, the problem frequently occurs in practice that the catheter becomes bent when lateral forces on the catheter hub occur during the handling thereof. In particular, a bend in the catheter can come about when the catheter is first inserted into the skin of the patient at an angle of approximately 30° due to the relatively awkward construction of the catheter hub and then, when the needle is removed from the catheter hub, the catheter comes to bear at an angle of approximately 8° relative to the surface of the skin, wherein the bending of the catheter is favoured by the angle difference occurring thereby. In  FIG. 9   a , the catheter hub  5  is represented after the insertion of the catheter  4  through the skin H into a vein V and in  FIG. 9   b  an unintentional downwards displacement of the catheter hub  5  is indicated, when, for example, an IV line  15  is attached thereto and/or by incorrect application of adhesive tape for fixing the catheter hub on the skin H the catheter hub is displaced downwards. A bend in the catheter  4  occurring hereby is indicated by K. Such a bend K in the catheter prevents throughflow and is usually irreversible, so that the catheter has to be removed and a new catheter  4  has to be inserted in the vein. 
         [0028]    By means of the embodiment according to the present method, system and device having a buffer element between the support element and the catheter hub, protection from bending is additionally provided for the catheter  4 , because possible bending between support element  20  and catheter hub  5  occurs at the flexible protective hose line  40  which can be bent straight again after bending, so that throughflow is not impeded. Preferably the flexible hose line  40  is formed thick-walled and manufactured from a correspondingly soft material, so that in the case of bending of the flexible hose line  40 , it is not damaged or made unusable. 
         [0029]    Thus, by means of the flexible and soft hose line  40 , the forces occurring at the catheter hub  5  are to a great extent uncoupled from the support element  20  and especially from the catheter  4 . 
         [0030]      FIG. 4  schematically shows an embodiment in which a support element  20  is fixedly attached at the relatively rigid distal end portion of the catheter  4 , this support element having diametrically opposite wing-like elements  20   a  and  20   b  which, during the insertion of the catheter into the vein of the patient, are at first folded together so that the needle  9  can be inserted at a flat angle relative to the surface of the skin, whereupon the two wings  20   a  and  20   b  are unfolded and can be fixed on the skin of the patient, for example by means of adhesive tape. After removal of the needle  9  from the catheter insertion device, an IV line or a syringe  14  can be attached at the catheter hub  5 , wherein the mechanical pressure P applied for this is absorbed by the flexible hose line  40  as a buffer element. 
         [0031]    Various modifications of the described embodiments are possible. For example, the catheter hub  5  can also be formed as one piece and the valve disc  7  can be inserted in a circumferential groove in the catheter hub, as  FIGS. 3 and 4  schematically show. Furthermore, a valve actuation element  10  can be omitted, and the syringe hub  14   a  or an IV line can come to bear directly on the check valve  7  by mechanical pressure P in order to open this valve, as follows from  FIG. 3 . 
         [0032]      FIG. 5  shows an embodiment in which a valve opener or a valve actuation element  10  is arranged in the catheter hub  5 . 
         [0033]      FIG. 6  shows an embodiment with a valve opener  10  and additionally provided needle guard element  13  in the form of a spring clip having crossing arms. The tip  9   a  of the needle  9  protrudes in the ready position over the distal end of the catheter  4 . In  FIG. 6 , the tip  9   a  and the distal end of the catheter are not shown. 
         [0034]      FIG. 7  shows an embodiment in which only a needle guard element  13  is held in the catheter hub  5  in the ready position, without a valve actuation element being provided. 
         [0035]      FIG. 8  shows an embodiment in which a shortened needle  90  is provided in connection with a support element  20 , wherein at the proximal end of the shortened needle  90  a wire  91  is fixed. whose proximal end is provided with a bulge  91   a  which abuts at the proximal outside of a cap  92 . In the ready position, the cap  92  is attached to the catheter hub  5 , wherein the needle  90  extends through the catheter  4  and the support element  20 , and the wire  91  extends through the flexible hose line  40 , the valve  7  and the catheter hub  5 . After inserting the catheter  4  into the vein of a patient, the cap  92  is detached from the catheter hub  5  and in this way, by means of the wire  91 , the needle  90  is withdrawn through the catheter hub  50 , whereupon the cap is removed from the catheter hub. 
         [0036]    The wire  91  can be connected with the end of the needle  90  by means of welding, bonding or crimping. When one of these types of connection is to close the end of the hollow needle, then a hole must be provided laterally at the proximal end of the hollow needle, to guarantee the passage of blood in the hose line  40 . The user recognizes the inflow of blood as a sign that the needle has entered the vein. The blood then flows only up to the valve disc  7 . 
         [0037]    Alternatively, the wire  91  is connected at the proximal end with a hub  8 , as shown in  FIG. 1 . 
         [0038]    The flexible hose line  40  is preferably formed transparent, so that blood flowing up to the valve  7  is clearly visible. Likewise, the tubular body  20 . 1  of the support element  20  can be formed transparent. 
         [0039]      FIG. 10  shows a modified embodiment wherein a releasable clamping means is provided on the support element  20  by means of which the needle  90  can be clamped on the support element when the needle  90  with the catheter  4  is inserted into the vein of a patient. This clamping means is actuated by folding the two wings  20   a  and  20   b  together, so that the passage in the support element through which the needle  90  extends is narrowed such that the needle  90  is fixed by clamping. In the embodiment as shown in  FIG. 10  a rib  22   a  and  22   b  is provided on the two wings  20   a  and  20   b  which extend into the tubular main body  20 . 1  in such a way that the needle  90  can pass between the ribs as long as the wings  20   a  and  20   b  extend essentially in the same plain, whereas the needle  90  is clamped between the ends of the ribs  22   a  and  22   b  when the two wings  20   a  and  20   b  are folded together. 
         [0040]    In the embodiment of  FIG. 10  a lug is provided on the distal side of the tubular main body  20 . 1  wherein the catheter  4  is held by means of a metal or plastic hub  21  as it is the case in  FIG. 3 . 
         [0041]    By means of the valve  7  provided in the catheter hub  5 , which valve automatically closes after the removal of the needle from the catheter hub and can be reopened as required, especially by a valve opener  10 . axial access is guaranteed at the proximal end of the catheter hub  5 , through which access a syringe or an IV line can be inserted into the proximal end of the catheter hub  5 . This results in a compact and space-saving construction at the catheter hub for an infusion or for blood collection. Hereby, a syringe or an IV line can be inserted in the catheter hub  5  as  FIG. 2  shows, or a syringe or an IV line can be connected to the catheter hub  5  via the Luer thread  6  ( FIG. 1 ), to attach a syringe or IV line axially to the catheter hub  5 .