Abstract:
A method and apparatus for inserting a catheter into a patient and measuring and approximating its distal end position within the body facilitate catheter insertion and improve accuracy and control. By wrapping a long infusion catheter with an outer coating, the catheter can be guided into a vein or vessel by pulling on the outer coating and forcing its separation in a Y-shaped separation housing anchored close to the insertion point. Since there is no need for a guidewire or stylet and the outer coating acts as a sterile peel package, the catheter can be placed while infusing and maintain its own closed sterile environment during insertion.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to methods and devices designed for controlling the movement of catheters useful in many medical procedures. In particular, an apparatus and method to facilitate a simple, closed, measurable insertion of a catheter without the need of a guidewire or stylet is disclosed. 
       BACKGROUND ART 
       [0002]    Long catheters are commonly introduced into blood and other vessels during numerous medical procedures. In some procedures, accurate placement within vessels is important and desirable. Generally, guidewires are first inserted into the vessel so that the distal end of the guidewire is at the desired position to be treated. Catheters are provided with a suitable lumen into which the proximal guidewire end is inserted and the catheter is slid over the guidewire or stylet to the desired position. 
         [0003]    In addition to difficulties associated with accurate, reproducible catheter placement, handling and manipulation of the catheters in an operating room environment can become unwieldy. Guidewires can create confusion about their use and may be a potential source of contamination during insertion. The need for maintaining sterility and verifying catheter placement is of concern. Of particular emphasis for this product is its application in emergency medicine where catheters need to be inserted quickly to begin therapies. Since there is less time in this environment, simpler more intuitive devices are favored, This environment also puts less emphasis on and has less capability of accommodating a sterile technique during insertion. Lastly this emergency environment often needs to maintain an infusion of fluid medications even before a long catheter is inserted into its final position. 
       SUMMARY 
       [0004]    A long infusion catheter is surrounded by an outer coating that is not adhered to the catheter but does form a tight friction fit along its length that does not allow the catheter inside to slide within the coating and also protects the catheter sterile surface. The distal end of this arrangement has been arranged within a Y-shaped separation housing such that the coating splits away from the catheter and exits a coating exit of the Y-shaped housing and the catheter exits a separate catheter exit. Then by pulling on the coating exiting the coating exit of the Y-shaped housing, the catheter with the coating is drawn into the Y-shaped housing, separated from the coating, and propelled through the catheter exit. The catheter exit is connected to an introducer catheter to facilitate passage of the catheter into the vessel. 
         [0005]    The coating serves additional purposes of preventing contamination to the catheter before separation and providing measurements about the inserted portion of the catheter by indicia printed on the coating. Measurements are also provided by using the separated coating length to trace the path of insertion and thereby approximate the distal end position of the catheter. The Y-shaped housing not only separates the coating from the catheter and allows for the propulsion of the catheter, the housing also insulates the catheter after separation from the coating by enclosing the exposed area of the catheter before it enters the introducer catheter. Since there is no guidewire needed for insertion, the long catheter can infuse fluids during insertion while determining position and/or final placement. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0006]      FIG. 1  is a perspective view illustrating a common long catheter that is jacketed along its entire length with a separable coating. 
           [0007]      FIG. 2  is a perspective view of a Y-shaped housing that is used to separate the coating from the catheter and to enable the simple propulsion of the long catheter. 
           [0008]      FIG. 3  is a perspective view of an embodiment of the invention with the “Y” shaped housing connected to an introducer catheter which shows that the catheter and separated coating are the same distance from the “Y” shaped housing, allowing the distal end of the separated coating to be used to approximate the distal end of the placed catheter by laying the coating over the expected path of the catheter. 
           [0009]      FIG. 4  is a perspective view illustrating flexible air/fluid seals at the entrance and exits of the Y-shaped housing. 
           [0010]      FIG. 5  is a perspective view illustrating an end cap attached to the female luer connector at the proximal end of the catheter. 
           [0011]      FIG. 6  is a perspective view illustrating a reel attached to the Y-shaped housing that mechanically draws the coating through the Y-shaped housing when the reel is turned. 
           [0012]      FIG. 7  is a perspective view illustrating the entrance of the Y-shaped housing with a blade located in the entrance of the housing. 
           [0013]      FIG. 8  is a perspective view illustrating a wire between the coating and catheter used to split the coating. 
       
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0014]    In an exemplary embodiment, the apparatus includes a long coating  10 , that has been fitted over a long catheter  12 , as shown in  FIG. 1  (often called a PICC Line) of the same length. The coating  10  is proportionally fitted and not adhered to the catheter and peels away easily. The coating is more flexible and pliant than the catheter  12 , A Y-shaped housing  19 , generally shown in  FIG. 2 , is provided with one entrance  14 , and two exits, including a coating exit  15  and a catheter exit  16 . The entrance lumen extends generally directly through to the catheter exit  16 , possibly changing lumen size at or near the point where the coating  10  is removed from the catheter  12 . The coating exit  15  leaves the housing  19  at an acute angle from the catheter exit  16 . The lumen of the entrance is such that it will accommodate the coating-wrapped catheter. The lumen of the catheter exit  16  will accommodate the catheter, and the lumen of the coating exit  15  will accommodate the coating. When the coating-wrapped catheter, again shown in  FIG. 2 , is drawn into the entrance of the Y-shaped housing, by drawing the coating  10  out through the coating exit  15 , the long catheter  12  inside the coating  10  is also carried into and through the Y-shaped housing  19 . The catheter  12  separates from the coating  10  within the Y-shaped housing  19  and is channeled to the catheter exit  16  as it is propelled forward. The catheter exit  16  has a luer lock connector  36  and is connected to an introducer catheter  26 , or equivalent, as shown in  FIG. 3 . The catheter is thereby guided through the introducer catheter  26  into the vessel where the introducer catheter  26  is located. 
         [0015]    By preventing sterile surfaces from contacting non-sterile surfaces, the device and method described herein preserve the sterility of the catheter portion which is to be inserted into the vessel. Additional prevention of contamination is achieved by flexible air/fluid seals attached to the entrance  14 , catheter exit  16  and coating exit  15  of the Y-shaped housing  19  that seal off clearance gaps between the Y-shaped housing  19  and the catheter  12  or coating  10  traveling within. The seals hold the catheter  12  and coating  10  in place thereby also functioning as brakes when the catheter  12  is not being advanced. This preservation of sterility for surfaces that have yet to be inserted, combined with the braking ability of the separation housing  19  on the catheter  12 , allow intermittent insertion of the catheter  12  into the vessel. The catheter  12  can be held in place for an indefinite period of time, then advanced further into the vessel at a later time by pulling out an additional length of coating  10  from the Y-shaped housing  19 . An example of utilizing this method is to insert the catheter  12  into vessel a small amount and infusing to achieve hydration and therefore increase overall vessel size. At a later time, after the vessel has increased in size due to the hydration, the catheter  12  can be advanced mid length into the vessel to facilitate infusions that require greater flow. Once diagnostic apparatus are in place to detect and determine final distal end position, the catheter  12  may be advanced further to the final insertion depth. At this point, the catheter  12  may remain in the Y-shaped housing  19  or be cut, refitted with a connector and anchored in place with a permanent securing device. 
         [0016]    The coating  10 , shown in  FIG. 1 , will have an oval, shaped or grooved outer profile  34  that aligns with a corresponding oval, shaped or grooved profile at the entrance of the Y-shaped housing  14  as shown in  FIG. 7 . This will align the slit  44  in the coating  10  within the Y-shaped housing  19  to facilitate peeling away the coating by the Y-shaped housing  19 . 
         [0017]    The apparatus and method described herein provide the ability to infuse through the catheter  12  during insertion. Fluid exiting the distal end of the catheter  12  can facilitate insertion by providing axial movement of the distal end of the catheter  12 , keeping it away from the vessel walls, thus facilitating passage within the vessel as it moves forward. 
         [0018]    The catheter may also be filled or primed with detectable media to enhance its appearance when viewed with external diagnostic equipment such as but not limited to x-ray. 
         [0019]    Numbered indicia printed on the exterior of the coating  10 , again shown in  FIG. 3 , facilitates a method of measurement where the insertion depth is measured by reading the indicia where the coating exits the coating exit  15  of the Y-shaped housing  19 . Dual indicia can be utilized. The first set of numbered indicia increases from a low number at the distal end  23  of the coating  10  to higher readings at the proximal end of the coating  10 . Reading these indicia at the coating exit  15  indicates insertion depth of the catheter  12 . A second set of indicia increases from the proximal end to the distal end  23  of the coating  10 . Reading these indicia at the coating exit  15  allows the determination of the amount of catheter available for insertion. 
         [0020]    The arrangement provides a method of catheter distal end point approximation, shown in  FIG. 3 , by utilizing the drawn length  27  of coating  10  that has exited the Y-shaped housing  19 . The drawn coating length  27  is placed above the intended path of the catheter  12  within the vessel. Since the exiting catheter and exiting coating are equidistant from the Y-shaped housing  19 , the distal end  23  of the coating  10  would be directly above the distal end of the catheter  20  within the vessel using this method. 
         [0021]    Ultrasound or other noninvasive diagnostic methods are often used during catheter insertion to visualize position or placement of a catheter being inserted within the vessel. Technicians often maneuver a wand or hand held type detector above the area to be viewed. By attaching a connector to the distal end  23  of the coating  10  and affixing the connector to the wand or hand held device, the catheter  12  may be advanced while simultaneously observing the distal end of the catheter  12  in the vessel as it progresses forward. 
         [0022]    Other catheter distal end detection methods utilize electronic or magnetic communication between a wire or electrical conduit within the lumen of the inserted catheter and an external detector located above the anticipated location of the wire/electrical conduit distal end within the catheter. The arrangement described herein could provide assistance to these types of detection by incorporating wire or electrical conduit within the coating itself to facilitate communication between the inserted wire/electrical conduit and the detection device. 
         [0023]    The coating  10  before separation within the Y-shaped housing  19  protects the surface of the long catheter  12  from contact contamination. The only area where the catheter  12  becomes exposed is inside the “Y” shaped housing  19  at the point where separation occurs until the point it exits the catheter exit  16  of the “Y” shaped housing  19 . To prevent contamination to the exposed catheter, the “Y” shaped housing  19  also seals out air and fluid. To accomplish this, the interior of the “Y” shaped housing  19  is completely enclosed and is fitted with flexible air/fluid seals at the entrance  14 , as shown in  FIG. 4 , the coating exit  15  and the catheter exit  16 . These flexible air/fluid seals are affixed to the “Y” shape housing  19  and conform to the outer surface of the catheter  12  or coating  10  that travels within to seal out air/fluid and still allow the catheter  12  or coating  10  to pass. By attaching an end cap  31 , as shown in  FIG. 5 , and/or an infusion source to the female luer  32  at the proximal end of the catheter  12 , the apparatus becomes a closed method of insertion. 
         [0024]    In  FIG. 4 , on the Y-shaped housing  19 , the entrance seal  41  at entrance  14 , the catheter seal  43  at catheter exit  16 , and coating seal  42  at coating exit  15  of the Y-shaped housing  19  further facilitate a unique feature of the arrangement by holding the catheter  12  in place within the vessel when the catheter is not being advanced. This arrangement ensures the catheter does not change depth unless the coating  10  is advanced through the Y-shaped housing  19 . Combined with the closed method of insertion detailed above, intermittent levels of insertion are available without the risk of the catheter  12  changing depth and becoming contaminated. 
         [0025]    Separation of the coating  10  from the catheter  12  inside the Y-shaped housing  19  can be accomplished in a variety of ways. The first method is to have a slit that runs along the entire length of the coating  10 , thus allowing the coating  10  to be pulled or peeled away at an angle and out the coating exit  15  of the Y-shaped housing  19 . Since the catheter  12  is more rigid than the coating  10 , the catheter  12  cannot make the same bend as the coating  10  and is propelled out the catheter exit  16 . Another method of splitting and separating the coating  10  is to attach a knife edge or blade  33 , as shown in  FIG. 7 , inside the Y-shaped housing  19  situated so that it slits the coating  10  only as it passes through the Y-shaped housing  19  and does not split the catheter  12  inside the coating  10 . Separation occurs as in the pre-split method detailed above. A third method is to incorporate a cutting wire  35 , shown in  FIG. 8 , or band between the catheter  12  and the coating  10  that splits the coating  10  as it is pulled out the coating exit  15  of the Y-shaped housing  19 , then separation occurs as described above. Another method to split the coating  10  and achieve separation within the Y-shaped housing  19  is to incorporate a seam of thinner material or a perforation into the coating wall. As the coating  10  is pulled to its coating exit  15  at an angle, and the catheter  12  cannot bend as it continues to the catheter exit  16 , a tear occurs in the coating  10  at this seam or perforation. Still another method is to incorporate a runner or band of material manufactured so that it is attached to the length of the catheter  12  so that the catheter  12  and the runner or band are of the same material and are one piece. The runner or band would separate from the catheter  12  and propel the catheter  12  out the catheter exit  16 , as the runner or band is pulled out of the coating exit  15  of the Y-shaped housing  19 . 
         [0026]    The Y-shaped housing  19  could be fitted with a take-up reel  40  for the coating  10  in which turning a knob  39  on the take up reel  40  as shown in  FIG. 6  would mechanically draw the coating  10  through the Y-shaped housing  19 . 
         [0027]    The present invention is more intuitive and facilitates quicker and simpler catheter insertions than present guide wire methods. The advantages of enhanced sterile technique are self apparent. The measurement methods facilitated and infusion options provided by the present invention presents a vast improvement over current methods that require alternate apparatus to accomplish these same results. Although the invention has been described in detail and also described with alternate embodiments, additional embodiments exist that remain within the scope of this invention. The foregoing disclosure, descriptions and figures are only for illustrative purposes and do not, in any way, limit the invention which is defined by the following claims.