Abstract:
A device and method for positioning a catheter to establish a fluid access site into the vasculature of a patient includes a luer assembly that incorporates the catheter. Also included is a shuttle assembly that has a stylet for stiffening the catheter. In combination, the stiffened catheter and the shuttle assembly are held on a handle by the interaction of the luer assembly with the handle. Once the stiffened catheter is inserted into the vasculature, the luer assembly is separated from the handle and from the stylet, and is left in place. With this separation, the shuttle assembly is also released to be repositioned and concealed within the handle.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention pertains generally to medical catheters. More specifically, the present invention pertains to devices that position the cannula of a catheter in fluid communication with the vasculature of a patient to establish a single fluid access site for repetitive or sequential use with an extracorporeal fluid source. The present invention is particularly, but not exclusively, useful as a device for manipulating a stylet to position a catheter in fluid communication with the vasculature of a patient, and for subsequently concealing the stylet, to thereby prevent inadvertent “sticks” with the stylet after it has been removed from the catheter. 
       BACKGROUND OF THE INVENTION 
       [0002]    Fluid access into the vasculature of a patient may be necessary, or desirable, for any of several different reasons. In the event, a fluid flow path must somehow be established between an extracorporeal fluid source and the vasculature. Moreover, when an infusion protocol is involved that requires periodic injections, an established fluid access site that can be repetitively used for a sequence of different injections may be required. Establishing such an access site, however, can be problematical. 
         [0003]    When a catheter is used to establish a fluid access site into the vasculature of a patient, the catheter itself (i.e. its cannula) is preferably flexible. The flexible catheter, however, needs to first be somehow stiffened so its distal end can be passed through tissue and thus positioned in the vasculature. Typically, this stiffening is accomplished using a stylet that can be selectively inserted into the lumen of the catheter. After the stiffened catheter has been properly positioned in the vasculature, the stylet must then be removed from the catheter to leave the catheter in fluid communication with the vasculature. Preferably, this separation of the catheter from the stylet is accomplished as easily as possible. Furthermore, once the stylet has been removed from the catheter, it becomes necessary to protect the user from inadvertent or accidental “sticks” by the sharp end of the stylet. 
         [0004]    In light of the above, it is an object of the present invention to provide a safety catheter that can be properly positioned, with its distal end in the vasculature of a patient, to thereby establish a single fluid access site for multiple infusions of a fluid medicament into the vasculature from an extracorporeal fluid source(s). Another object of the present invention is to provide a safety catheter that can, in a single-step operation, be separated from a stiffening stylet with an automatic concealment of the stylet to prevent inadvertent or accidental “sticks” by the sharp end of the stylet. Yet another object of the present invention is to provide a safety catheter that is easy to manufacture, is simple to use, and is comparatively cost effective. 
       SUMMARY OF THE INVENTION 
       [0005]    In accordance with the present invention, a safety catheter is provided that is operationally prepared for immediate insertion into the vasculature of a patient. Specifically, the intent is to establish a single fluid access site into the vasculature of the patient that can be repetitively or sequentially used by extracorporeal fluid sources (e.g. a hypodermic syringe or IV pump). For the present invention, the positioning of the safety catheter is accomplished using a dedicated device. The functionality of this dedicated device is essentially two-fold. For one, the device is initially used to stiffen the catheter with a stylet. This is done so the otherwise flexible cannula of the catheter can be effectively inserted and positioned in the patient&#39;s vasculature. For another, once the catheter is positioned, the device is engineered to automatically withdraw the stylet from the catheter, and to simultaneously conceal the stylet so its sharp end will not inadvertently or accidentally “stick” the user or some other third person. 
         [0006]    Structurally, the safety catheter essentially has three components. They are: a handle, a luer assembly, and a shuttle assembly. Considering each component separately, the handle of the safety catheter includes an elongated handle body that has a proximal end and a distal end. It is also formed with an internal chamber that extends between the two ends. Further, the handle includes a hollow, cylindrical-shaped body top having a proximal end and a distal end. A plurality of resilient fingers are formed on the body top to extend in a substantially distal direction from its distal end. Importantly, the body top is formed with a clear plastic window that is located between the proximal end of the body top and the distally-extending resilient fingers. To create the handle, the proximal end of the body top is bonded to the distal end of the handle body. 
         [0007]    Another component of the safety catheter, the luer assembly, is the component that is used to actually establish the site for fluid access into the vasculature of the patient. Importantly, the luer assembly Includes a flexible cannula having a proximal end and a distal end. For the construction of the luer assembly, an eyelet is affixed to the proximal end of the cannula, and the eyelet is then fitted onto a hollow body portion. The purpose here is to hold the cannula on the body portion. With the eyelet fitted on the body portion of the luer assembly, the cannula extends distally from a distal end of the body portion. Additionally, a one-way valve is positioned on the body portion at a location that is proximal to the eyelet. The purpose of this one-way valve is to establish selective access to a fluid flow path that passes through the luer assembly from a proximal end of the body portion and through the cannula. 
         [0008]    As mentioned above, in addition to the handle and the luer assembly, the safety catheter also includes a shuttle assembly. Structurally, the shuttle assembly includes a hollow, substantially tubular-shaped shuttle body that is molded from clear plastic. The shuttle body has a proximal end and a distal end, and it has an external surface that is formed with diametrically opposed flats that are located near the distal end of the shuttle body. Further, the shuttle body includes a hollow stylet having a sharp, beveled distal end, and it has a proximal end that is bonded to the distal end of the shuttle body. 
         [0009]    Functionally, the shuttle assembly is mounted on the handle for movement from a first location, through the chamber of the handle body, to a second location inside the chamber. In this first location, the shuttle assembly is engaged with both the luer assembly and the handle. Specifically, the stylet of the shuttle assembly is inserted through the lumen of the cannula of the luer assembly in order to stiffen the cannula. Also, the luer assembly is fitted onto the handle and against the resilient fingers to urge the fingers of the handle against the flats of the shuttle assembly. This holds the shuttle assembly at the first location with the stiffened cannula extending in a distal direction from the handle. Accordingly, the stiffened cannula (catheter) of the luer assembly can be positioned in the vasculature of a patient. 
         [0010]    To remove the stylet (i.e. shuttle assembly) from the cannula (i.e. luer assembly), and thereby affect a movement of the shuttle assembly from the first location to the second location, the luer assembly is simply separated from the handle. This separation then activates a spring mechanism inside the handle. In more structural detail, the shuttle assembly is formed with a lip, and the handle is formed with an abutment. With the shuttle in its first location, a spring is compressed between the lip of the shuttle assembly and the abutment of the handle. When the luer assembly is separated from the handle, however, the fingers of the handle are released from the shuttle assembly and the spring is thereby decompressed. As the spring expands, the shuttle assembly is repositioned to the second location inside the chamber. With this separation of the handle and shuttle assembly from the luer assembly, the luer assembly is left in place in the vasculature. 
         [0011]    Prior to a use of the safety catheter of the present invention, a shield is engaged with the handle. Thus, when the shuttle assembly is at the first location, the shield covers the luer assembly. This is a protective measure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The novel features of this invention, as well as the invention itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which: 
           [0013]      FIG. 1  is a straight-on side view of a safety catheter of the present invention; 
           [0014]      FIG. 2  is a view of a luer assembly of the safety catheter shown in its operational environment wherein the luer assembly is positioned to establish a site for fluid access into the vasculature of a patient; 
           [0015]      FIG. 3  is an exploded perspective view of the device shown in  FIG. 1 ; 
           [0016]      FIG. 4  is a cross section view of a luer assembly of the device as would be seen along the line  4 - 4  in  FIG. 3 ; 
           [0017]      FIG. 5  is a cross section view of a shuttle assembly of the device as would be seen along the line  5 - 5  in  FIG. 3 ; 
           [0018]      FIG. 6  is a cross section view of a handle assembly of the device as would be seen along the line  6 - 6  in  FIG. 3 ; 
           [0019]      FIG. 7  is a cross section view of a combination of the respective assemblies shown in  FIGS. 4 ,  5  and  6 ; 
           [0020]      FIG. 8  shows a configuration for the device of the present invention with the shuttle assembly at a first location on the handle assembly; and 
           [0021]      FIG. 9  shows a cross section view of a configuration for the present invention with the shuttle assembly at a second location on the handle assembly. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0022]    Referring initially to  FIG. 1 , a safety catheter in accordance with the present invention is shown and is generally designated  10 . More specifically, the safety catheter  10  is shown to include a handle  12  having a textured surface, and a shield (cap)  14 . In  FIG. 1  the shield  14  is shown engaged with the handle  12 . With this engagement, ribs (not shown) that are located inside the shield  14  help stabilize components of the safety catheter  10  prior to its use. For an operational use of the safety catheter  10 , however, the shield  14  is removed from the handle  12 . 
         [0023]    In  FIG. 2 , a luer assembly  16 , which is an essential component of the safety catheter  10 , is shown positioned to establish fluid communication with the vasculature of a patient  18 . As intended for the present invention, the luer assembly  16  is used to establish a single fluid-access site for repetitively or sequentially infusing fluid medicaments into the vasculature of a patient  18  from a fluid source (not shown). 
         [0024]    The exploded view of the safety catheter  10  that is shown in  FIG. 3  illustrates the various component parts that are required for construction and assembly of the catheter  10 . As shown, in addition to the shield  14 , the safety catheter  10  includes a hollow body portion  20 , a cannula  22 , an eyelet  24 , and a one-way valve  26 . In combination, these particular parts establish the luer assembly  16 . Further, it will also be seen that the body portion  20  has guides  28  which are formed in the hollow of the body portion  20 . 
         [0025]    In order to assemble the luer assembly,  FIGS. 3 and 4  show that the proximal end  30  of the cannula  22  is bonded to the eyelet  24 . The eyelet  24  is then fitted into the hollow body portion  20  so that the cannula  22  extends from the distal end  32  of the body portion  20 , with its distal end  34  exposed. Also, as shown in  FIG. 4 , the luer assembly  16  includes a one-way valve  26  that is positioned at a location inside the hollow body portion  20 , proximal to the eyelet  24 . For the purposes of the present invention, the cannula  22  is preferably made of a flexible, bio-compatible elastomeric material. 
         [0026]    Returning briefly to  FIG. 3  it will be seen that the safety catheter  10  also includes a stylet  36  and a shuttle body  38 . Further, in  FIG. 5  it will be seen that a filter plug  40  is positioned inside the shuttle body  38 . It will also be seen in  FIG. 5  that the distal tip  42  of the stylet  36  is beveled to present a sharp end for penetrating tissue of the patient  18 . And, the proximal end  44  of the stylet  36  is bonded to the distal end  46  of the shuttle body  38 .  FIG. 5  also shows that the distal end  46  of the shuttle body  38  is formed with diametrically opposed flats  48   a  and  48   b.  Together, and as shown in  FIG. 5 , the stylet  36  and the shuttle body  38 , in combination with the filter plug  40 , establish a shuttle assembly  50 . For the present invention, the shuttle body  38  of the shuttle assembly  50  is preferably made of a clear plastic material. 
         [0027]    With reference to  FIG. 3  it is to be appreciated that the handle  12  of safety catheter  10  includes a handle body  52  and a body top  54 . Structurally, the proximal end  56  of the body top  54  is bonded to the distal end  58  of the handle body  52 . Further, as best seen in  FIG. 6 , the handle body  52  is formed with an internal chamber  60 . Also, the body top  54  is formed with a window  62  that is located between the proximal end  56  and the distal end  64  of the body top  54 . Importantly, the body top  54  is formed with a pair of resilient fingers  66   a  and  66   b  that extend in a distal direction from the distal end  64  of the body top  54 . Each of the resilient fingers  66   a  and  66   b  is formed with a respective nib  68   a  and  68   b.  Additionally, a registration flat is formed at the distal end  64  to prevent rotation of the handle  12  when it is engaged with the shield (cap)  14 . Preferably, the body top  54  is made of a clear plastic material. 
         [0028]      FIG. 3  also shows that the safety catheter  10  includes a spring  70 . More specifically, when the safety catheter  10  is assembled, the spring  70  is positioned between a lip  72  that is formed on the shuttle body  38  (see  FIG. 5 ) and an abutment  74  that is formed inside the body top  54  (see  FIG. 6 ). As intended for the present invention, the spring  70  is used to selectively provide a motive force that will change the configuration of the safety catheter  10  during its operation. 
       Operation 
       [0029]    In the operation of the safety catheter  10  of the present invention, it is necessary that the shuttle assembly  50  be moved from a first location on the handle  12 , to a second location inside the chamber  60  of the handle  12 . More specifically, with the shuttle assembly  50  in its first location on the handle  12 , the safety catheter  10  can be used to establish fluid access for the luer assembly  16  into the vasculature of the patient  18 . To maintain this fluid access site, the luer assembly  16  needs to be effectively separated from the rest of the safety catheter  10 . This is done by moving the shuttle assembly  50  to its second location inside the handle  12 . Further, with the shuttle assembly  50  in its second location, the sharp distal tip  42  of the stylet  36  is effectively concealed inside the chamber  60  of the handle  12  to prevent inadvertent or accidental “sticks” by the stylet  36 . 
         [0030]    Referring now to  FIG. 7 , when the shuttle assembly  50  is in its first location, the luer assembly  16 , the shuttle assembly  50  and the handle  12  all interact with each other. In more detail, with the engagement of the shuttle assembly  50  to the luer assembly  16 , the stylet  36  of the shuttle assembly  50  extends through the lumen in the cannula  22  of the luer assembly  16 . This stiffens the cannula  22 . At the same time, the guides  28  in the hollow body portion  20  of the luer assembly  16  register the stylet  36  of the shuttle assembly  50  with the luer assembly  14 . Also, as the hollow body portion  20  of the luer assembly  16  is positioned over the resilient fingers  66   a  and  66   b  of the body top  54 , the respective nibs  68   a  and  68   b  are aligned with flats  48   a  and  48   b  of the shuttle body  38  by the guides  28  of the luer assembly  16 . This interaction between the luer assembly  16  and the handle  12  effectively holds the shuttle assembly  50  in its first location on the handle  12 . A view of the safety catheter  10  when the shuttle assembly  50  is in its first location on the handle  12  is shown in  FIG. 8 . There it will be seen that the stiffened cannula  22  (i.e. as it is stiffened by the stylet  36 ) extends distally from the handle  12  for insertion of the cannula  22  into the vasculature of a patient  18  (see  FIG. 2 ). It should also be noted that, as shown in  FIG. 7 , while the shuttle assembly  50  is in its first location, the spring  70  is compressed between the lip  72  on the shuttle body  38  and the abutment  74  on body top  54 . 
         [0031]    To confirm the safety catheter  10  has been properly positioned (i.e. the luer assembly  16  is in fluid communication with the vasculature of the patient  18 ), a blood “flash” can be observed through the window  62 . The filter plug  40  then confines the blood that enters into the shuttle assembly  50  with this “flash”, and prevents blood born pathogens from leaking out of the safety catheter  10 . At this point, the luer assembly  16  can be disengaged from the handle  12 . To do this, the hollow body portion  20  of the luer assembly  16  is lifted and removed from the resilient fingers  66   a  and  66   b  of the shuttle body  38 . In turn, this causes the resilient fingers  66   a  and  66   b  of the handle  12  to be lifted from the flats  48   a  and  48   b.  This action disengages the body top  54  of the handle  12  from the shuttle assembly  50 . At this point, the compressed spring  70  is no longer constrained. Thus, an expansion of the spring  70  then moves the shuttle assembly  50  through the internal chamber  60  to its second location on the handle  12  (see  FIG. 9 ). Importantly, as a consequence of the above-described functionality, the luer assembly  16  remains in place in fluid communication with the vasculature of the patient  18  (see  FIG. 2 ). Further, as best appreciated with reference to  FIG. 9 , the distal tip  42  of stylet  36  can be observed through the window  62  when the shuttle assembly  50  has been properly concealed within the chamber  60  of the handle  12 . 
         [0032]    While the particular Safety Catheter as herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages herein before stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as described in the appended claims.