Abstract:
An IV catheter insertion device includes a flash chamber into which blood (or other fluid) flows to confirm the proper placement of the catheter. Within the device is a movable member which is controlled from outside, as by a health care worker moving a plunger to move the movable member and expel blood from the flash chamber through the needle for testing or other analysis. The plunger may have a locking and unlocking mechanism to present the movement of the plunger from occurring when it is not desired.

Description:
BACKGROUND OF THE INVENTION 
     A patient admitted to a hospital, an outpatient treatment center, or an outpatient surgery center will have an intravenous (IV) catheter inserted for easy access for fluids and drugs to be administered to the patient. The IV catheter is typically inserted using an IV insertion device, and some of these IV insertion devices have become known in the industry as JELCOs after the name of one company which brought these insertion devices to market. It is frequently necessary for a sample of the patient&#39;s blood to be obtained—e.g., for testing, blood typing or other analysis. For many of these blood tests, only a small sample of blood is required. After the IV catheter has been inserted, the healthcare worker may obtain this blood sample by various means. One method would be to have the patient endure another needle stick either by a needle and syringe to draw an aliquot of blood or by pricking the patient&#39;s finger with a lancet for a few drops of blood. 
     Some have proposed to use some of the blood that remains within the JELCO or IV catheter insertion device after the IV catheter has been inserted in a patient. Most IV catheter insertion devices include an integrated flash chamber. Red blood appears within the flash chamber of an IV catheter insertion device as the operator inserts the needle of the IV catheter insertion device into the vein to show that the IV catheter has entered a vein. The operator watches the flash chamber continuing to fill with blood as the operator advances the IV catheter into the vein, thereby ensuring the IV catheter remains properly positioned within the vein. Usually the proximal end of the flash chamber is blocked by a flash plug. The flash plug typically includes a filter material that allows air to vent from the flash chamber as the blood or fluid fills the chamber, but prevents the blood or fluid from passing from the flash chamber. IV catheter insertion devices of the prior art may have one of two different types of flash plugs. An IV catheter insertion device, such as described in U.S. Pat. No. 5,000,740, has a fixed or non-removable flash plug. Another type of prior art IV catheter insertion device is seen in U.S. Pat. No. 4,917,671 with a removable flash plug. 
     When an IV catheter has been placed within the vein, the remainder of the JELCO or IV catheter insertion device is removed from the patient. A small amount of the patient&#39;s blood remains within the flash chamber of the JELCO or IV catheter insertion device. By accessing the patient&#39;s blood from the flash chamber of the IV catheter insertion device, the operator may be able to avoid an additional needle stick to the patient. There are some known approaches to access blood in the flash chamber of an IV catheter insertion device. One such approach in IV catheter insertion devices with a non-removable flash plugs involves using an external probe, such as a pen or a golf tee, to push an internal flash plug within the flash chamber to expel blood from the flash chamber. The use of an external device such as a golf tee or pen is undesirable for several reasons. The external device must be stored some place that is easily accessible to the operator. The use of an external device is inefficient as the worker must look for or gather additional equipment when accessing the captured blood or fluid and replace the additional equipment for its next use. If the worker were to reuse any external probe or device (including a pen or a golf tee), cross-contamination may occur from one flash chamber to another, putting other patients and the healthcare worker at risk. 
     In IV catheter insertion devices that have removable flash plugs, another prior art approach to access the blood in a flash chamber requires the healthcare worker to remove the flash plug, thereby opening the flash chamber to access the blood within the flash chamber for testing. This action may unnecessarily expose the healthcare worker to hazardous material (such as blood or other bodily fluid) that may spill from the flash chamber. 
     While various prior art methods may allow the healthcare worker to access the blood or fluid within the flash chamber of an IV catheter insertion device (or JELCO), these methods present inefficient and undesirable aspects and limitations to the health care worker. 
     The present invention addresses some of these undesirable limitations and aspects to provide an improved device and method for accessing blood from an IV catheter insertion device without the use of undesirable additional hardware and without unnecessary risks. This new method and device will thereby increase the efficiency of the healthcare worker and reduce the hazardous exposure of bodily fluids to the workers and patients. 
     SUMMARY OF THE INVENTION 
     The present invention provides a system and method for providing a self-contained system for removing blood (or other fluid) from an IV catheter insertion device (or JELCO) in a controlled manner upon demand and with greater ease and less risk to the worker. 
     The present invention has the advantage of reducing the number of needle sticks to a patient by using blood or bodily fluid that has been collected within the IV catheter insertion device when the IV catheter is placed. That is, the fluid sample used for testing is a by-product of the use of the IV catheter insertion device. 
     Applicant teaches in this patent application that blood collected within the flash chamber of an intravenous catheter insertion device can be accessed with an integral structure safely and efficiently. The blood or fluid thus collected can be used for analysis or testing without requiring the healthcare worker to inflict additional needle sticks to a patient. 
     It is desirable that an IV catheter insertion device (or JELCO) be simple to make and maintain in a sterile condition. It is also desirable that the device be self-contained and not require additional tools, e.g., an external device like a golf tee in order to access the blood contained in the flash chamber. 
     It is also desirable that the operator be able to access the blood or fluid within the IV catheter insertion device without having to open the flash chamber, thereby reducing the chance for exposure of hazardous material to the worker and patient. 
     The present invention overcomes the disadvantages and limitations of the prior art systems while providing a simple, yet effective, way of accessing the blood contained in the flash chamber of an IV catheter insertion device for testing and analysis. 
     Other objects and advantages of the present invention will be apparent to those of ordinary skill in the art in view of the following detailed description of the preferred embodiment taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1   a  is a perspective view of one type of prior art IV catheter insertion device (a JELCO); 
         FIG. 1   b  is a cross sectional view of the IV catheter insertion device of  FIG. 1   a;    
         FIG. 2  is an exploded view of portions of the IV catheter insertion device of  FIGS. 1   a  and  1   b , modified to include one form of the present invention; 
         FIG. 3  is a cross sectional view of the IV catheter insertion device of  FIGS. 1   a ,  1   b  and  2 , showing one form of the present invention; 
         FIG. 4  is a perspective, exploded view of portions (one example of a plunger and cap assembly) of the invention, prior to assembly of them into the IV catheter insertion device; 
         FIG. 5  shows side and bottom views of the plunger of  FIG. 4 ; 
         FIG. 6  is a perspective and cutaway view of the cap shown in  FIG. 4 ; 
         FIG. 7  is a perspective, exploded view of an alternate type of prior art IV catheter insertion device having a removable flash plug; 
         FIG. 8  is a perspective view of an assembly of the removable flash plug of  FIG. 7 , augmented with a plunger of the present invention in its primary position; 
         FIG. 9  is a perspective view of the removable flash plug and plunger of  FIG. 8  with the plunger extended to its secondary position; 
         FIG. 10  is a perspective view of the removable flash plug and plunger of  FIG. 9  being inserted into the alternate type of IV catheter insertion device shown in  FIG. 7 ; 
         FIG. 11  is a view of the components of  FIG. 10  assembled together; 
         FIG. 12  is a view of the IV catheter insertion device after insertion of the IV catheter has been inserted and the remainder of the device removed; and 
         FIG. 13  is a view of the IV catheter insertion device of  FIG. 12  with the plunger moved forward to expel blood (or other fluid) from the flash chamber of the insertion device. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The following illustrates the use of the preferred embodiment of this new method and device. 
       FIG. 1   a  illustrated one example of a prior art IV catheter insertion device (which medical personnel sometimes referred to as a “JELCO”)  1 . The IV catheter insertion device  1 , shown enlarged and in perspective in this view, includes an IV catheter  2 , a distal end  3  and a barrel  4  at a proximal end  4   a . This  FIG. 1   a  illustrates one example of an IV catheter insertion device  1  having a non-removable flash plug at the proximal end of a flash chamber (not shown in this view), the construction and operation of an example of which system is more fully described in detail in U.S. Pat. No. 5,000,740, the specification and drawings of which are specifically incorporated herein by reference. 
       FIG. 1   b  depicts more detail for the IV catheter insertion device  1  of one prior art JELCO which forms one environment for the present invention. This  FIG. 1   b  shows a cut-away view of the IV catheter insertion device  1  shown in  FIG. 1   a  and includes the barrel  4 , a flash plug  5 , a flash chamber  6 , and a needle  7  with a distal tip  7   a  and a proximate end  8  which communicates with the flash chamber  6 . The barrel  4  of the IV catheter insertion device  1  and the flash chamber  6  are both formed from a transparent material, such as a plastic, so that one can clearly see through the barrel  4  into the flash chamber  6 , so that when blood enters into the flash chamber  6 , the red color of the blood is clearly visible outside the IV catheter insertion device  1 . The needle  7  includes an internal aperture extending from its distal tip  7   a  to its proximate end  8  adjacent the flash chamber  6 , so that when distal tip  7   a  of the needle  7  is properly inserted within a patient&#39;s vein (not shown), blood from the vein can enter the flash chamber  6  (and be visible to an observer looking from outside the IV catheter insertion device  1 ). 
       FIG. 2  is an exploded view of selected components of the IV catheter insertion device  1  of the present invention (but not all of the components). The needle  7  includes its distal tip or end  7   a  and a proximate end  8  which is secured within the flash chamber  6  of the IV catheter insertion device  1 . The flash chamber  6  is contained within the barrel handle  4   b  and is shown with screw threads  6   c  at the proximate end  6   a  of the flash chamber  6 . The flash plug  5  comprises a flash plug filter  11 , a rubberized seal  12  and a cap  13 . The cap  13  includes internal threads (not shown) which couple with the screw threads  6   c  on the flash chamber  6  when the device  1  is fully assembled and ready for use. The proximate end  8  of the needle is secured within the flash chamber  6  and sealed so that the blood flows from the distal end  7   a  of the needle  7  to the flash chamber  6  where it is secured. A plunger  20  is formed by a shaft  14  and a handle  15  and is mounted through a central aperture in the cap  13 . This plunger  20 , through its shaft  14  and handle  15 , can be moved by a user through apertures extending through the cap  13  and the rubberized seal  12  to press against the flash plug filter  11  and move the flash plug filter  11  away from the operator within the flash chamber  6  to expel blood, as desired, from the distal end  7   a  of the needle  7 . 
     In one preferred embodiment as seen in  FIG. 3 , the plunger  20  including the shaft  14  and the handle  15  extend through the cap  13  which can be seen coupled to the proximal portion of the flash chamber  6 . The healthcare worker, or operator, uses the IV catheter insertion device  1  to insert an IV catheter in the usual manner. As the operator inserts the needle tip  7   a  into the vein, the flash chamber  6  fills with blood. In this embodiment, as the operator advances the IV catheter, the barrel  4  (which serves as a needle guard) advances distally over the distal tip  7   a  of the needle  7 . As the barrel or needle guard  4  advances distally over the needle  7 , the shaft  14  and handle  15  of the invention becomes exposed for the operator. With the IV catheter insertion device  1  in this locked position, the operator can position the distal tip  7   a  of the needle  7  over a testing strip or blood receiving cassette. The operator then grasps the handle  15  and rotates the shaft  14  and handle  15  enough to disengage the shaft  14  from its locked position. Using the handle  15 , the operator advances the shaft  14  and plunger  20  from the proximal position in the flash chamber  6  to the distal position of the flash chamber  6 . The action of moving the shaft  14  and plunger  20  from its retracted position to its forward position will force the blood or fluid within the flash chamber  6  back through the needle  7  and to exit at the distal tip  7   a  of the needle  7 . As the blood or fluid is expressed from the needle tip  7   a , the operator can direct this blood or fluid onto a testing strip or other blood receiving container such as a cassette or cartridge. The entire IV catheter insertion device  1  (other than the IV catheter  2 , which remains within the vein of the patient) can then be disposed of properly into a hazardous waste container. 
       FIG. 4  shows detail of the plunger  20  including the shaft  14  and the handle  15  as used in the environment of  FIGS. 1   a - 3  as described above. The shaft  14  includes a plurality of grooves extending along the length of the shaft  14 , two of which are shown in this  FIG. 4  as reference numerals  17   a  and  17   c . A notch  16  cooperates with one groove  17   a  to form a locking mechanism in cooperation with a projection  18  in the cap  13 . The plunger  20  is initially locked with the projection  18  fitting within the notch  16 , then the operator rotates the handle  15  of the plunger  20  in the direction of the arrow R to release the locking mechanism and allow the plunger  20  including shaft  14  and handle  15  to move in the direction of arrow P along the length of the shaft by allowing the projection  18  to move along the groove  17   a.    
       FIG. 5  illustrates the elements of  FIG. 4  in a bottom view and a side view to better understand the present invention. As shown here, the plunger  20  includes an enlarged handle  15  which is generally round and fits within the barrel  4  of the IV catheter insertion device  1 . The shaft  14  is also generally cylindrical and of a smaller diameter to fit within an aperture through the cap  13  which fits within the barrel  4  of the device  1 . Grooves  17   a ,  17   b ,  17   c  are shown disposed around the periphery of the shaft  14 . The notch  16  is adjacent to and cooperating with one groove  17   a  to provide a locking (and releasing) mechanism for the plunger  20  along the length of the shaft  14 . 
       FIG. 6  are a perspective view and a cut-away view which illustrate detail of the cap  13  and its projection  18  which cooperates with the notch  16  to provide locking and unlocking the shaft  14  of the plunger  20  and, when unlocked, allows the shaft  14  of the plunger  20  and the flash plug  11  to move forward within the flash chamber  6 . The cap  13  includes internal screw threads  19  which mate with the screw threads  6   c  of the flash chamber  6  when the device is assembled. 
     In another embodiment, the present invention can be used in conjunction with an alternate IV catheter insertion device  9  which includes a removable flash plug  10  as is illustrated in  FIG. 7 .  FIG. 7  shows some of the components in a prior art IV catheter insertion device  9  of the type described in connection with U.S. Pat. No. 4,917,671, a patent whose drawings and specification are incorporated herein by reference. The IV catheter insertion device shown in this  FIG. 7  includes the IV catheter  2 , the needle  7  extending from the distal needle tip  7   a  at its distal end  3  to its flash chamber  6  with a removable flash plug  10 . The removable flash plug  10  has a handle  10   a  and a leur tip  10   b  which connects within the flash chamber  6 . The present invention involves substitution/modification of a modified plunger assembly  20   a  including a handle  15   a  and a removable flash plug for the flash plug  10  shown in this  FIG. 7  as will be described in connection with later illustrations, particularly  FIGS. 8-10 . This substitution can occur, as desired, either during the initial manufacture and assembly of the IV catheter insertion device  9  or at the point of use e.g., bedside, using sterile techniques, preferably immediately prior to the operator inserting the IV catheter into the patient. 
       FIG. 8  shows the handle  15   a  and the shaft  14   a  of the modified plunger assembly  20   a  in their initial position extending through the removable flash plug  10  with its handle  10   a  and its leur tip  10   b . A shaft end piece  14   b  is mounted on the other side of the leur tip  10   b  from the handle  15   a.    
       FIG. 9  shows the relative positions of the handle  15   a , shaft  14   a , the shaft end piece  14   b , and the flash plug  10  when the plunger  20   a  has been extended (when it has been moved to expel blood from the flash chamber  6 , not shown in this view). A significant portion of the shaft  14   a  extends below the leur tip  10   b . The shaft end piece  14   b  consists of filter material to allow air to vent and prevents fluid from escaping. 
       FIG. 10  shows the components of the IV insertion device  9  of the present invention in an exploded view. As shown here, the IV insertion device  9  includes a needle  7 , an IV catheter  2 , a flash chamber  6  and the plunger assembly  20   a  of  FIGS. 8-9  with the handle  15   a  and the shaft  14   a.    
       FIGS. 11-13  show the IV catheter insertion device  9  as discussed in connection with  FIGS. 7-10  wherein  FIG. 11  shows the device prior to insertion of the IV catheter into a patient,  FIG. 12  shows the device  9  after the IV catheter has been inserted into a patient and blood appears within the flash chamber  6  and the IV catheter  2  removed, and then  FIG. 13  shows the device of  FIG. 12  with the handle  15   a  moved forward in the direction of arrow P to expel blood from the flash chamber  6  to the distal end  7   a  of the needle  7  as indicated by the arrow B. Initially in  FIG. 11  the plunger  20   a  including the handle  15   a  and the shaft  14   a  are at a rear or withdrawn position and preferably locked against accidental movement of the plunger  20   a . After the IV is inserted into the patient, the IV catheter  2  is detached from the remainder of the IV insertion device  9  and the flash chamber  6  has become filled with blood  6   d  and the flash plug  14   b  is at the rear or proximate end of the flash chamber  6 . The handle  15   a  and shaft  14   a  may be unlocked by rotating them to release them from the locking mechanism and moved forward or distally from the original position to a position as shown in  FIG. 13 . As the shaft  14   a  and handle  15   a  are moved forward, the shaft end (filter)  14   b  is also moved forward and urges the blood from the flash chamber  6  distally through the needle  7  out its distal tip  7   a , where drops of blood  6   d  are shown. 
     An example of this embodiment can be seen in  FIGS. 8-10 . These figures illustrate from proximal to distal, a shaft handle  15   a , a shaft  14   a , a handle  10   a  with a luer-tip connector  10   b  through which the shaft  14   a  passes. The shaft  14   a  and handle  15   a  form a plunger  20   a  cooperating with the with filter material  14   b  to vent air as blood enters the flash chamber but prevents blood or fluid from escaping through the flash plug  10 . The plunger may or may not have a rubberized seal to seal the plunger within the walls of the flash chamber  6 . In this embodiment, the standard flash plug  10  has been removed and replaced by the assembly of the present invention  20   a  including the handle  10   a  with the plunger having its handle  15   a  and shaft  14   a  which has been inserted into and secured within the flash chamber  6  using the luer connector  10   b . The operator is then ready to insert the IV catheter  2 . The operator will insert the IV catheter  2  in the usual manner. After the IV catheter  2  has been inserted and secured, the operator removes the remainder of the IV insertion device  9 . The operator then moves the deployed IV catheter insertion device  9  with blood or fluid within the flash chamber  6  to a position over a testing strip or cassette. The operator will grasp the handle  15   a  and rotate the handle  15   a  and the shaft  14   a  enough to unlock the locking mechanism. The operator will then push the handle  15   a  to move the shaft  14   a  and filter  14   b  at the distal end of the shaft  14   a  within the flash chamber  6  from the proximal position  6   a  within the flash chamber  6  ( FIG. 12 ) to the distal position  6   b  within the flash chamber  6  ( FIG. 13 ). The movement of the shaft  14   a  and filter  14   b  in the direction of arrows P from the position of  FIG. 12  to the position of  FIG. 13  will force the blood or fluid through the needle  7  in the direction of the arrow B toward the distal end  7   a  of the needle  7 . As the blood or fluid (represented by drops of blood  6   d ) is expressed from the distal tip  7   a  of the needle  7 , the operator can direct this blood or fluid  6   d  onto a testing strip or cassette (not shown). The operator can then dispose of the entire IV insertion device  9  (with the IV catheter  2  removed and remaining installed within the patient) into a hazardous materials container. Because the invention has replaced the removable flash plug  10  prior to insertion of the IV catheter  2 , the operator can access the blood or fluid  6   d  within the flash chamber  6  without opening the flash chamber  6  or removing the flash plug  10 , thereby reducing the possibility of exposure of hazardous material to the operator or patient. 
     Of course, many modifications to the best mode described above may be effected without departing from the spirit of my invention. Further, some of the features disclosed may be useful without the corresponding use of other features. For example, the use of an internal plunger within a rigid chamber could be replaced with a flexible flash chamber with an external, but integral, compression device for squeezing the flash chamber to expel blood out of the flash chamber. Further, the specific construction of the plunger and its coupling to the flash plug could be changed to advantage in some alternate embodiments of the present invention, and any locking and unlocking of the plunger is optional, as is any system for limiting the advance of the plunger. Further, if desired, the plunger could be provided with a system which limits the speed at which the plunger moves forward to provide a controlled method for expelling blood or other fluid from the flash chamber, even to the extent of limiting the blood removal to a drop at a time. The materials of the IV catheter insertion device including the barrel and the flash chamber are typically made from a transparent plastic material for easy of manufacture and durability as well as easy visual inspection of the flash chamber, but other materials, including glass, could be used for the barrel and the flash chamber, and need not be wholly transparent (a window or a translucent system might be used to advantage, if desired). Many other modifications could be used to advantage in some cases involving the present invention. Additionally, a different access point to the blood in the flash chamber could be used, if desired, in some instances. For example, an aperture with a cover in the wall of the flash chamber and/or the barrel of the insertion device might be opened to access the blood contained in the flash chamber and allow for an operator to expel blood on demand using a plunger or other pressure-applying force to remove blood through the aperture and cover, a system which avoids exposing the sharp needle of the catheter insertion device. Additionally, the insertion device has been described in connection with a catheter insertion device which accesses blood from a vein, but the present invention would also be applicable to a device which accesses other body fluids, such as spinal fluid, pleural fluid, ascites, other body fluids, or even some body tissues. Accordingly, the foregoing description of the preferred embodiment should be considered as merely illustrative of the principles of the present invention and not in limitation thereof. The scope of the present invention is to be determined solely by the claims which follow.