Abstract:
A catheter syringe conveyor with a needle guard housing is adapted for facilitating the insertion of a catheter into a targeted blood vessel. A catheter syringe is slidably situated within the slot of housing, allowing the technician to maneuver the syringe up and down within the housing. A blood vessel stabilizer, having a pair of stabilizer fingers, is attached to the bottom of the housing and holds the blood vessel in place while the syringe is maneuvered within the stabilized housing. After the blood vessel is penetrated by the needle of the syringe, the technician maneuvers a catheter pusher to lower the catheter into the blood vessel. After the catheter is inserted, the technician is able to slide the syringe back up within the housing, to move the needle within the protective walls of the housing for safety; a syringe lock holds the syringe there for safekeeping

Description:
[0001]    This application claims the benefit of U.S. Provisional Application No. 60/788,747 filed on Mar. 30, 2006. 
     
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This invention relates generally to catheter insertion devices, specifically to a catheter syringe conveyor which has a needle guard housing. 
         [0004]    2. History of Technology 
         [0005]    In order to install an indwelling catheter into a blood vessel of a patient, a medical technician will often struggle with the fact that the targeted blood vessel may tend to move away from an incoming introducer needle. A second problem is that the needle is exposed for a substantial length of time during the procedure, limiting safety. A third problem arises when the targeted blood vessel is an artery; the artery is often difficult to locate. A fourth problem is that it is difficult for the technician to maintain a straight path of insertion. A fifth problem is that it is typically impossible to keep exposed fingers away from the puncture site. The present invention solves these problems. 
         [0006]    An indwelling venous catheter is inserted into a targeted blood vessel of a patient by a qualified technician, typically for the purpose of infusing liquid substances into the patient or for occasionally removing venous blood from the patient. The catheter is inserted using a catheter syringe. After the catheter is inserted properly, the syringe is removed, and the catheter is secured to the patient. 
         [0007]    Although the present invention is adapted for use with both venous and arterial catheters, for the purpose of clarity, this discussion will focus mostly on arterial catheters, also known as arterial lines, a-lines, or art lines. An arterial catheter is inserted into a selected artery of a patient by a technician, usually in a critical care environment within a healthcare facility. Arterial catheters are used typically for blood pressure monitoring and for patients who are in need of frequent arterial blood draws. A variety of catheters are available; a standard 20-gauge straight intravenous catheter is one type which is frequently used. The radial artery is the insertion site of choice, but other arterial sites may be used if necessary; these alternative sites include the femoral, brachial, ulnar, axillary, and dorsalis pedis arteries. Arterial blood sampling is achieved utilizing a separate access port placed onto the hub of the inserted catheter, and may be performed for blood collection and for blood gas analysis. Arterial blood gas analysis is performed to determine at least the partial pressures of oxygen (PaO2) and carbon dioxide (PaCO2), and the pH of the blood sample. These values are important in assessing pulmonary function, since these measurements indicate the status of gas exchange between the lungs and the blood. 
         [0008]    The catheter is retained over the introducer needle of a catheter syringe. When the technician inserts the introducer needle into the artery, a flash of blood in the blood receptacle of the syringe signals the technician that proper placement of the needle within the artery has occurred. The catheter is then slid off of the introducer needle and the needle is removed from within the catheter, leaving only the catheter in the artery. The catheter hub is then connected to a transducer tubing system, and then the hub is secured to the patient&#39;s wrist. 
         [0009]    A variation of the standard arterial catheter syringe is a syringe with a guide wire unit attached. The guide wire is used to help guide the catheter into the artery; after the technician has inserted the introducer needle properly into the artery, the technician advances the guide wire through the hollow needle and into the artery, providing a track over which the catheter can be fed into the artery. 
         [0010]    A modified Allen Test (collateral circulation test) should always be performed by the technician before inserting a needle and catheter into a patient&#39;s radial artery. The Allen Test determines if blood is capable of flowing through the ulnar artery. The ulnar artery is the only other source of blood to the hand aside from the radial artery. A negative test result is indicative of inadequate collateral blood supply to the hand and requires the selection of another location as the site for catheter insertion. 
         [0011]    The catheter insertion procedure is difficult and prone to errors, even when the technician has ample experience. Because of the traumatic nature of the procedure, and the large number of complications that may arise from complications, it is important for the technician to try to insert the catheter properly on the first attempt. Prior art has seriously failed to provide technicians with adequate means to insert an arterial catheter regularly on the first attempt. 
         [0012]    An unrestrained blood vessel may tend to move away from an incoming needle, particularly in older patients whose skin has become loose and has lost elasticity. A loss of elasticity in the skin creates a loss of stability around the blood vessel, which allows the vessel to roll around under the surface of the skin. It is possible for a needle to push the vessel away from its path, causing the technician to miss the targeted vessel completely. The present invention solves this problem by providing a blood vessel stabilizer to hold the vessel in place during a catheter insertion attempt. 
         [0013]    Currently, the technician will press her or his finger over an anticipated arterial puncture site and then estimate where the artery lies under that finger; it is a rough estimate and the technician often miscalculates. Alternatively, the technician may place two fingers over the artery and attempt to hold the artery in place between the fingertips, inserting the needle between the two fingertips to attempt to penetrate the artery. This method has its limitations; the technician should have a tight pair of gloves, cannot have long finger nails, and will rely on bulky finger tips to pinpoint a relatively thin artery between them, and this technique is impossible to use on infants and small children. The present invention uses a blood vessel stabilizer to hold the artery within two integrated stabilizer fingers at the base of the device, and it partially occludes the artery during use; this creates a stable and augmented pulse at the site where the needle will enter the artery, simplifying palpation of the artery and vastly diminishing the labor involved in identifying where to insert the needle. A blood vessel stabilizer further allows the technician to keep any exposed extremities away from the puncture site while inserting the needle into the site, thus improving safety. 
         [0014]    Because of low blood pressure, a patient&#39;s pulse may be weak and hard to locate. It is sometimes necessary for the technician to perform an arterial puncture “blindly,” merely stabbing the site where the technician considers the best option for obtaining arterial access. The present invention helps to create an augmented pulse that is palpable even in cases of low blood pressure. 
         [0015]    Most protocols allow a technician to try three consecutive needle insertions without removing the needle tip beyond the subcutaneous tissue. As the angle of insertion changes within the dermis, the needle slices through the tissue in its path, and may even lacerate the artery. Any change in the angle of needle insertion can inflict severe pain onto a conscious patient. 
         [0016]    Because of the structural design of the present invention, a straight, unswerving path of needle insertion into the blood vessel is assured. Currently, the often unsteady hand of the technician is used to guide the needle down into the blood vessel. A nervous hand can become quite jittery, and even a calm hand does not guarantee a straight path of insertion into and out of the vessel. The present invention provides a considerable improvement in this regard; pressing the stabilizer, at the base of the invention, down near the insertion site provides stability to the hand of the technician. The straight slot within the housing, which supports the syringe, vastly improves the likelihood of a direct and controlled line of insertion and extraction of the needle during a catheter insertion procedure, minimizing pain and trauma within the patient&#39;s dermal tissues and artery. 
         [0017]    Often, the unrestrained nature of the current methods for inserting a catheter into a blood vessel causes the introducer needle to become accidentally extracted from within the blood vessel during a catheter insertion attempt. The present invention prevents this common mishap, by providing a solid, steady housing within which the syringe is securely held in place during the procedure. 
         [0018]    According to standard procedure protocols, a catheter introducer needle should enter an artery at a steady angle of 30 to 45 degrees in relation to the artery distal the heart near the insertion site; prior art relies on the technician to maintain that angle without any support. A proper angle of needle insertion is assured using the present invention, as a result of the base of the stabilizer fingers being angled in relation to the housing slot within which the syringe is maneuvered. 
         [0019]    3. Prior Art 
         [0020]    Prior art includes devices which help a technician insert a catheter into a blood vessel, and also devices which stabilize a blood vessel in place during the insertion of a needle therein. 
         [0021]    Most of the devices within the realm of prior art do not address the issue of safety adequately. Most catheter insertion devices require the integrated needle to be exposed during much of the procedure; this can be hazardous to technicians and patients if the syringes are handled improperly or unsteadily, as may commonly occur in emergency situations. Needle sticks are the most frequent source of transmission of blood borne disease in healthcare workers. In most of the devices of prior art, the needle is exposed before and after the insertion procedure and there are no means provided to protect personnel from contact with the needle during the procedure. Some devices have disclosed means to withdraw the introducer needle into a safety enclosure after successful insertion of the catheter, but they do not go far enough to prevent injuries and they are difficult to use. Using the current invention, the needle is exposed for only a short period during the entire procedure; the needle is lowered and exposed only after the device has been set over the targeted insertion site. Immediately after the catheter is inserted into the blood vessel, the needle is safely withdrawn out of the blood vessel and back into the protective walls of the housing using only one hand. 
         [0022]    Another limitation of prior art is that stability of the device during the procedure is lacking. The stabilizer of the present invention is pressed down near the insertion site to provide stability to the hand of the technician, and a straight path of needle insertion is assured, limiting tissue damage. 
         [0023]    Several devices have been proposed for stabilizing a vein for venipuncture, but none of the devices provide proper support for arterial puncture. For arterial puncture, the blood vessel stabilizer portion of the device should be relatively small to accommodate the limited space over the radial artery near the hand, and it should be shaped to facilitate palpation of the targeted puncture site by the technician. The device should be designed to allow a proper angle of needle passage into the artery, and it should be easily removed from the puncture site; it cannot be bound or taped down during use. These features are all present in the current invention. 
         [0024]    The present invention may be used on any artery, not just the radial artery. The present invention includes a syringe conveyor to help guide the introducer needle steadily into and out of the artery. The present invention allows the technician to release the pressure over the artery before removing the needle from the insertion site. 
         [0025]    The present invention can be adapted to integrate any one of a large variety of catheter syringes. The present invention further includes an adjustable blood vessel stabilizer to accommodate various sizes of targeted blood vessels. 
         [0026]    4. Objects and Advantages 
         [0027]    Accordingly, several objects and advantages of the present invention include providing a catheter syringe conveyor which has a needle guard housing, which: 
         [0028]    (a) slidably retains a catheter syringe and renders a straight path of needle passage into and out of the blood vessel. 
         [0029]    (b) allows the introducer needle to be immobilized safely within the housing. 
         [0030]    (c) is held in place using only one of the technician&#39;s hands. 
         [0031]    (d) helps the technician to keep the tip of the needle steadily within the blood vessel. 
         [0032]    (e) shields the technician&#39;s fingers from the sharp needle tip during use, to prevent inadvertent injury. 
         [0033]    (f) can be used on any individual of any age and size, and on any suitable blood vessel. 
         [0034]    (g) can integrate a large variety of catheter syringes, including one with a guide wire. 
         [0035]    (h) minimizes the need for multiple attempts to penetrate the blood vessel. 
         [0036]    (i) assures a proper angle of needle insertion into a blood vessel. 
         [0037]    (j) allows unrestricted blood flow through the ulnar artery when the radial artery is targeted. 
         [0038]    (k) holds a blood vessel in place during the insertion of a catheter into the vessel. 
         [0039]    (l) isolates an artery and creates an augmented pulse for easy identification of the location of the artery. 
         [0040]    (m) is inexpensive to manufacture, simple and intuitive to use, disposable, and light-weight. 
         [0041]    (n) allows the technician to regulate the pressure of the device above a blood vessel. 
         [0042]    (o) allows the technician to alter the width between each stabilizer finger. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0043]      FIG. 1A  is an upper left perspective view of one embodiment of the invention having a stabilizer specifically designed for use with arterial punctures, depicting aspects of the invention including the housing, the stabilizer attached at the bottom end of the housing, the catheter protruding from the aperture at the bottom end of the housing, and the syringe arm and catheter pusher arm emanating from the housing slit. 
           [0044]      FIG. 1B  is an enlarged partial perspective view of the device in  FIG. 1A , focusing on the syringe arm, the catheter pusher arm, and the series of notches within which the locking tooth may be locked. 
           [0045]      FIG. 1C  shows a lower left perspective view of the access aperture at the bottom end of the housing. 
           [0046]      FIG. 1D  shows a lower perspective view of the syringe and the catheter pusher as they would be positioned within the housing in  FIGS. 1A-1C , with the housing removed. The catheter pusher is shown separated from the syringe for illustrative purposes. 
           [0047]      FIG. 1E  shows an upper perspective view of the arrangement in  FIG. 1D   
           [0048]      FIG. 2  is an enlarged perspective view of an alternative catheter pusher which has a special catheter hub connector which allows for easy removal of the hub from the connector. 
           [0049]      FIG. 3  is an upper left perspective view of the invention with an integrated guide wire unit. 
           [0050]      FIG. 4  is an enlarged lower rear perspective view of an alternative stabilizer with each stabilizer finger situated within a track to allow adjustability of the distance between each finger. 
           [0051]      FIG. 5  is a perspective view of an embodiment, similar to the one in  FIG. 1A , which has a blood vessel stabilizer for use with venous catheter insertions. 
           [0052]      FIG. 6  is a perspective view of an embodiment having more spaced out stabilizer fingers. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0053]    Referring now to the drawings,  FIGS. 1A-6  represent various embodiments and designs of the present invention. Each embodiment utilizes the novel feature of employing a catheter syringe conveyor which has a syringe holder slidably positioned within a protective housing, and a stabilizer which is pressed against the patient to stabilize the device during use. Turning first to  FIG. 1A , stabilizer  10  includes base  12  and stabilizer fingers  14  and  16 . Stabilizer fingers  14  and  16  emanate from base  12 . A targeted artery is positioned by the technician between stabilizer fingers  14  and  16 . Alternatively, only one finger protrudes from base  12 ; the single finger would hold only one side rather than both sides of a targeted artery. Housing  18  is attached to base  12 . Stabilizer fingers  14  and  16  serve to stabilize housing  18  as well as to stabilize a targeted artery during use. The bottom surface of each stabilizer finger is angled relative to housing  18 . The angle may be 30 degrees, 45 degrees, any angle between 30 and 45 degrees, or any other angle suitable for the procedure. Slot  20  runs through housing  18 . A catheter syringe is situated within slot  20  and is lowered within slot  20  by the technician to guide the needle of the syringe down into the targeted artery; the needle passes between and distal the tips of stabilizer fingers  14  and  16  as shown. Housing bridge  22  connects each side of housing slit  24 . Syringe arm  26  and catheter pusher arm  28  emanate through housing slit  24  from inside of slot  20  for access by the technician. Catheter pusher arm tooth  30  is capable of locking over catheter pusher arm stop  32  when catheter pusher arm  28  has been slid down housing  18  far enough by the technician; this locks catheter pusher arm  28  in place, facilitating access to the hub of catheter  34  by the technician. The syringe and the catheter pusher, with everything attached thereon, are inserted through top end  36  of housing  18  during assembly of the device, preferably accomplished by the manufacturer prior to distribution. Housing ridges  38  help the technician securely grip housing  18  during use. 
         [0054]    Turning to  FIG. 1B , syringe arm locking tooth  40  engages within one notch of the series of notches  42  cut along a linear path within housing  18 ; this acts as a syringe lock because syringe arm  26  is locked in place, and syringe arm  26  is connected to the syringe holder (not shown). 
         [0055]    Looking at  FIG. 1C  now, aperture  44  at the bottom end of housing  18  provides ample space through which the technician may grasp the hub of catheter  34  when it is time to do so during the procedure. 
         [0056]    Turning next to  FIG. 1D , catheter pusher  50  is disposed below syringe  52  within the housing slot (not shown). Blood receptacle  54  of syringe  52  is slidably retained within the housing slot by syringe shell  56 . Alternatively, syringe arm  26  may be connected directly to blood receptacle  54 , eliminating the use of shell  56 ; in this case, it would be necessary to configure blood receptacle  54  with a certain shape which matches the shape of the slot through which it is passed, or at least provide some means for blood receptacle  54  to travel stably within the slot. Needle  58  is attached to blood receptacle  54 . Needle  58  passes through catheter pusher  50 . Catheter  34  is removably positioned over needle  58 . Catheter pusher  50  is shown slightly separated from syringe  52  for illustrative purposes. As positioned, the tip of needle  58  would reside at location  60  within catheter  34 . During a catheter insertion procedure, catheter pusher  50  would continue to be maneuvered by the technician down the housing slot until it reached the bottom of the housing. At that juncture, the technician would raise needle  58  out of the artery and back into the protective walls of the housing. Catheter hub  62  would be grasped by the technician, released from catheter hub connector  67 , and held in place over the artery as the rest of the device is removed and set aside or discarded safely. Catheter hub connector  67  has a threaded inner surface to retain catheter hub  62 ; in order to remove hub  62  from connector  67 , the technician may twist hub  62  off of the threaded hub connector. In this embodiment, catheter hub connector  67  is attached to push member  66 . Alternatively, a catheter hub connector is not included, and instead, catheter hub  62  merely resides over needle  58  directly adjacent push member  66 ; in this scenario, push member  66  would push catheter hub  62  down over needle  58  as catheter pusher  50  is maneuvered by the technician down the slot of the housing. In another alternative embodiment, blood receptacle  54  would have a protuberance at the point where needle  58  is attached to it, and the protuberance would act as a catheter holder, and push member  66  would be positioned between blood receptacle  54  and catheter hub  62 ; push member  66  would serve to push catheter hub  62  off of the protuberance and then down the needle during a catheter insertion procedure. As yet another alternative, catheter holder  67  can be configured as a protuberance over which the hub of the catheter can be removably held. Syringe arm engagement tooth  70  enters within catheter pusher engagement seat  72  when each is properly aligned and syringe arm  28  is maneuvered appropriately by the technician; the technician presses down on syringe arm finger contact  74  to accomplish this. The engagement of engagement tooth  70  within engagement seat  72  serves to allow the technician to maneuver catheter pusher  50  together with syringe  52  as the technician attempts to position the tip of needle  58  within the targeted artery. Once, the needle tip has penetrated the targeted artery, finger contact  74  is released, thus freeing engagement tooth  70  from engagement seat  72 . Then, catheter pusher arm  28  is maneuvered separately by the technician, maneuvered down the housing to guide catheter  34  into the artery. Alternatively, the technician&#39;s finger could simply contact both syringe arm finger contact  74  and catheter pusher arm  28  simultaneously as the both are maneuvered together by the technician, without the need for an engagement tooth and a corresponding engagement seat. The technician would release finger contact  74  after the artery is penetrated, and proceed to maneuver only catheter pusher arm  28  down the housing. Another alternative is for the catheter pusher arm to protrude out of the top opening of the housing, so that only the syringe arm protrudes through the housing slit; the technician would maneuver the catheter pusher from the top of the housing, momentarily requiring the use of the technician&#39;s free hand. 
         [0057]    Looking now at  FIG. 1E , air vent  76  is located within the top end of blood receptacle  54 . Needle  58  is shown more clearly here emanating from its attachment to blood receptacle  54 . 
         [0058]    Turning now to  FIG. 2 , this alternative catheter pusher utilizes the special catheter hub connector illustrated. A catheter hub is placed within space  80  between hub holder fingers  78  and back wall  82 . Hub holder fingers  78  are designed to allow the catheter pusher to push an attached catheter up or down over a needle. When the catheter has been inserted into the artery, the technician can remove the hub from within fingers  78  by pressing the hub down, in the direction of open segment  84  of the catheter pusher, so that the fingers release the hub. Open segment  84  allows the catheter pusher to be installed directly over the syringe, without having to pass it over the needle first. 
         [0059]    Referring to  FIG. 3 , in this alternative embodiment, which utilizes a guide wire unit, guide wire enclosure  90  is attached to the top end of the syringe (not shown). A flexible guide wire is attached to guide wire handle  92  within guide wire enclosure  90 . The technician maneuvers guide wire handle  92  down guide wire enclosure  90  to transmit the attached guide wire down through the blood receptacle, then further through the needle, and then into the targeted artery, during a catheter insertion procedure. 
         [0060]    Turning next to  FIG. 4 , stabilizer fingers  150  are slidably situated within adjustment track  152  so that the distance between each finger can be altered to accommodate various sizes of targeted blood vessels. It can be designed as a more complex apparatus, such as one which requires the technician to turn a knob to alter the distance between each finger, but a simple one is shown here for ease of illustration. 
         [0061]    Turning now to  FIG. 5 , stabilizer fingers  160  each have a rounded protrusion at the end of the finger; a vein is situated between the fingers during a catheter insertion attempt. Since the stabilizer fingers contact the epidermis approximately tangential to the point where the needle penetrates the vein, at point  162 , the technician is able to tilt the device during the procedure. The fingers extend at a very small angle from point  164 , relative to the housing, so that after the vein has been penetrated by the needle, the housing can be brought down nearly parallel to the vein, to allow an effective angle of catheter insertion into the vein. If the targeted vein is properly obstructed distal the insertion site, the vein should not collapse under the pressure of the stabilizer fingers. 
         [0062]    Turning finally to  FIG. 6 , this is similar to the embodiment in  FIG. 5 , except stabilizer fingers  170  are spaced apart more, so as to prevent any possible obstruction of venous blood flow through the targeted vein.