Abstract:
The present invention provides a needle guard comprising a base having a needle well to guide the point of a needle into the patient and, at the same time, for confining the pointed end of a needle within the walls of the needle well until the needle is inserted into a patient. The base is connected by at least a connector to a handle. The connector is constructed to allow the needle to be pushed beyond the needle well thereby exposing the needle. The connector also limits the extent to which the needle can be retracted. This prevents the needle from being pulled past the needle well as the needle is extracted from the patient. As a consequence of the construction, the point of the needle is substantially maintained within the needle well, except when the needle is inserted into the patient. The present invention also provides a method and an assembly for safely handling a medical needle by keeping the needle point confined within the needle well prior to insertion into a patient, and after retraction from the patient.

Description:
FIELD OF THE INVENTION 
   The present invention provides a needle guard for handling a medical needle, an assembly of the needle guard and the medical needle, and a method of using the needle guard to safely insert and/or retract the medical needle from a patient, and in the case of infusion needles into and out of the access port of a vascular access device within the patient. 
   BACKGROUND 
   In the modem age of AIDS, hepatitis and other blood-borne diseases, needle-stick injuries pose a grave concern to the medical field. It is therefore not surprising that various safety devices have been proposed to make the use of medical needles in general, and infusion needles in particular, safer for the clinician to use. Some examples of such devices are found in U.S. Pat. No. 6,537,255 to Raines, U.S. 2002/0169425 to Guzzo et al., U.S. 2002/0072716 to Barrus et al., U.S. Pat. No. 6,261,259 to Bell, U.S. Pat. No. 5,951,522 to Rosato et al., U.S. Pat. No. 5,584,813 to Livingston et al. and U.S. Pat. No. 4,631,058 to Raines. In addition, a hinged-wall system has been proposed in U.S. Pat. No. 5,531,704 to Knotek. Nevertheless, because the consequence of needle-stick injuries can be particularly severe, there is an ongoing demand to optimize the safety of handling needles. 
   When a patient requires constant or prolonged administration of a fluid or a drug dissolved in a fluid medium, it is known to implant a vascular access device to provide a convenient method of administration. Such devices are also used to remove fluids from the patient. Typically, the vascular access device is implanted subcutaneously adjacent to an area to be treated, such as the chest or the abdomen. 
   Vascular access devices usually comprise an access port or septum positioned under the skin. To administer or remove fluids, an infusion needle called the Huber needle is often used. The Huber needle often has an approximately 90 degree bend which separates the needle into a first section with a sharpened or pointed end, and a second section with an end for connecting to medical tubing that is capable of being connected to a source of fluids. The end of the second section may or may not be specially adapted with connectors to make connection to a medical tube easier. When used, the pointed end is pressed down in a substantially perpendicular direction relative to the surface of the skin over the access port. Once inserted, the second section is substantially parallel to the skin surface, and can be secured, by for example, tape to the patient. 
   It is well-known that Huber needles are particularly difficult to insert and/or remove from the access ports. This presents a particularly dangerous hazard to clinicians, because a force sufficient to insert or remove the needle may also cause an accidental needle-stick injury to the clinician. Moreover, when such needles are used with a vascular access device, they also have a “rebound” or “bounce back” effect, wherein to counter a sufficient force to remove such needles, a corresponding opposing force is exerted which causes the needle to rebound or bounce back towards the origin of the force. This rebound effect increases the likelihood of an accidental needle-stick, when the clinician attempts to remove the needle from the access port. 
   Moreover, medical needles, such as hypodermic needles, phlebotomy needles, intravenous needles, etc., have also been implicated in substantial number of accidental needle-stick injuries. It would be useful to have a device which will confine the point of the needle within a relatively tight space until the needle is inserted into a patient, and will permit the needle to be inserted with minimal or no exposure outside of the tight space, or the patient. It is presumed that one of ordinary art would understand that, for the most part, the needles referred to herein are hollowed medical needles with an opening on each end to allow passage of fluid therethrough. 
   SUMMARY OF THE INVENTION 
   The present invention provides a needle guard comprising a base having a needle well to guide the point of a needle into the patient and, at the same time, for confining the pointed end of a needle within the walls of the needle well until the needle is inserted into a patient. The base is connected by at least a connector to a handle. The connector is constructed to allow the needle to be pushed beyond the needle well thereby exposing the needle. The connector also limits the extent to which the needle can be retracted. This prevents the needle from being pulled past the needle well as the needle is extracted from the patient. As a consequence of the construction, the point of the needle is substantially maintained within the needle well, except when the needle is inserted into the patient. The present invention also provides a method and an assembly for safely handling a medical needle by keeping the needle point confined within the needle well prior to insertion into a patient, and after retraction from the patient. 

   
     BRIEF DESCRIPTION OF THE FIGURES 
       FIG. 1  is a perspective front view of a needle guard. 
       FIG. 2  is a perspective rear view of a needle guard. 
       FIG. 3  is a perspective front and bottom view of a needle guard. 
       FIG. 4  is a perspective front view of a needle guard assembly with an optional separate needle cover. 
       FIG. 5  is a perspective bottom and side view of a needle guard assembly with an optional integral needle cover. 
       FIG. 6  is a perspective rear view of a needle guard assembly. 
       FIG. 7  is a rear view of a needle guard assembly. 
       FIG. 8  is a cross-sectional side view of a needle guard assembly showing the point of the needle surrounded by the needle well. 
       FIG. 9  is a perspective front view of a needle guard assembly in its activated state, where the needle is pushed beyond the needle well. 
       FIG. 10  is a cross-sectional side view of a needle guard assembly showing the point of the needle pushed beyond the needle well. 
       FIG. 11  is a perspective rear view of a needle guard assembly in its retracted state, where the needle is surrounded by the needle well, and the connectors in the locked position. 
       FIG. 12  illustrates an embodiment of a needle guard assembly using a straight needle. 
   

   DETAILED DESCRIPTION 
   The invention is described by the following examples. It should be recognized that variations based on the inventive features disclosed herein are within the skill of the ordinary artisan, and that the scope of the invention should not be limited by the examples. To properly determine the scope of the invention, an interested party should consider the claims herein, and any equivalent thereof. In addition, all citations herein are incorporated by reference. 
   In  FIG. 1 , an embodiment of a needle guard  10  according to the invention is shown. The needle guard comprises a base  12  attached by a first connector  14  and a second connector  16  to a handle  18 . Base  12  further comprises a base top  24  having a guide  20  that surrounds a space above base top  24 . Guide aperture  21  extends through guide  20 , and provides a passage for the needle to extend through guide  20 . Although a guide  20  is not needed, when it is present, guide aperture  21  constitutes part of the needle well  22  to guide the needle point. In that case, the walls of the needle well  22  would necessarily include the walls of guide  20 . 
   The needle well  22  extends through base  12 , from base top  24  to base bottom  26 . If there is a guide  20 , needle well  22  also includes any guide aperture  21  of the guide  20 . Base  12  may also comprise optional positioning gaps, such as those shown as positioning gaps  28 ,  30  and  32 . In the illustrated embodiment, positioning gap  30  is located adjacent to guide  20  and well  22  to provide a means to locate the appropriate insertion area of the patient. 
   A needle holder  34  is attached to both first connector  14  and second connector  16 . The needle holder  34  is located closer to handle  18  than base  12 , and comprise a bore  36  which is formed to intimately secure a needle. In another embodiment, needle holder  34  is integral to the underside of handle  18 . In a further embodiment, bore  36  has some play so that needle holder  34  can slide up and down the needle, as the needle is inserted and retracted. Other methods of securing the needle to the needle guard may include adhesive bonding agents, UV-cured adhesives, clips, runners, and such. 
   In  FIG. 2 , connectors  14  and  16  are shown with an optional integral lock with lock parts  38  and  40  to lock needle guard  10  in a secured position when the needle is not being used. Though shown as opposing latches, different locking mechanisms are known in the field. For example, lock parts  38  and  40  can be complementary male and female tabs, or a head and recess locking means. Moreover, the function of lock parts  38  and  40  need not be performed by an integral part. Connector  14  and  16  may also be secured by a clip or a locking pin that is inserted into locking holes in the connectors (not shown). Needle guard  10  may also be secured by a stopper that physically separates the base from the handle. In an embodiment, the locking mechanism is used after the needle is retracted from the patient. In another embodiment, the locking mechanism is used before the needle is inserted, can be unlocked when the needle is to be inserted, and then locked when the needle is retracted. 
   Handle  18  is shown as a substantially horizontally flat structure with an optional groove  42  formed to provide sufficient clearance to insert a medical needle. In the embodiment shown in  FIG. 3 , handle  18  has a lip  44  adjacent groove  42  to provide additional pressure against a partially horizontal part or connector to a medical needle when inserting the needle into the patient. In the present embodiment, handle top  46  provides a surface for a clinician to press down when inserting the needle. Handle wings  48  provide a handle for the clinician pulls the wings by handle bottom  50  to extract the needle from the patient. 
   In  FIG. 4 , a needle  52  with two sections is assembled with needle guard  10  to form a guarded needle assembly. As illustrated here, needle  52  has a piercing section  54  which is separated from a connector section  56  by a substantially right angle. The particular severity of the angle is not crucial to the invention. As shown, the piercing section  54  of needle  52  is inserted through bore  36  of needle holder  34 , then into guide  20  such that the pointed end  58  (see  FIGS. 8 and 9 ) of the needle is secured within the walls of needle well  22 . In the present embodiment, medical tubing  60  is attached to and substantially envelopes connector section  56 . An optional separate sliding cover is also shown which is capable of slipping over base  12  along base bottom  26  and has holders that secures the cover along the edges of base  12  to keep the needle well  22  covered when the needle is not in use. In  FIG. 5 , the needle assembly is shown with an optional integral needle cover  62 , which is attached to base  12  by a scored section  64  which acts as a hinge. Needle cover  62  can be swung in the direction of the arrow shown to cover all or a portion of base bottom  26  so that needle well  22  is covered when the needle is not in the patient. In another embodiment, needle cover  62  and base  12  have an integral locking mechanism, whereby needle cover  62  can be locked in-place to base  12 . Different locking mechanisms are known in the field, and can include, for example, male and female tabs, and head and recess locking means. 
   In  FIG. 8 , a side cross-section is shown of needle  52  within needle well  22 . Although shown with pointed end  58  in needle well  22 , the pointed end can reside anywhere within needle well  22 , including within guide aperture  21 , to be secured. This is the position of the needle prior to use, or after it is secured in the inactive position, upon withdraw from the patient. 
   When used, the clinician uses base  12  and optionally locating gaps  28 – 32  to place the assembly on the patient, so that the needle is above the port of the vascular access device. Once the proper location is found, the clinician can press against base top  24  to secure the base  12  of the assembly against the patient. The clinician can with the same hand, or a different hand, press down against handle top  46  to insert the needle into the patient. Obviously, if needle well  22  is covered, one needs to uncover the well before attempting to insert the needle. The activated needle is shown in  FIGS. 9 and 10  with a portion of piercing section  54  inserted into the patient. The vascular access device is not shown, because the assembly need not be used with the vascular access device. The needle guard can be used any time a medical needle is indicated for the patient. Note that in the present embodiment, connectors  14  and  16  are shown as accordion walls having three walls ( 68 ,  70 ,  72  for one connector, and  68 ′,  70 ′,  72 ′ for the other connector) each having a hinge that allows the accordion to fold out ( 74  and  74 ′), and a hinge that allows the accordion to fold downwards ( 76  and  76 ′). Other embodiments of the connectors, may include, telescoping walls, springs or a material that can be resiliently compressed (not shown). In alternative embodiments, a single connector that surrounds the needle well may be used. 
   When activated, and the clinician presses down against handle top  46  so that connectors  14  and  16  folds out to provide room for the needle to plunge down ( FIG. 9 ). In one embodiment, the downward force is transmitted through the needle holder  34  because bore  36  substantially secures the needle to the connectors. In another embodiment, bore  36  has sufficient play, such that needle holder  34  can slide along needle  52  until lip  44  presses against an at least partially horizontal section of the needle, or a connector to the needle. In the embodiment shown here, lip  44  can press down on connector section  56  or tubing  60  at the end proximate to piercing section  54 , to transmit the downward force against the needle. In this case, the force is directed downward substantially along the linear axis of the piercing section  54  of needle  52 , to provide an optimal penetrating force that is perpendicular to the surface of the patient. In addition, guide  20  prevents the needle from sliding along the surface of the patient and causing unintended needle stick injuries.  FIG. 10  provides a sectional view of the assembly when the needle is inserted into patient  66 . Once in the patient, the entire assembly can be taped to the patient. 
   To remove the needle from the patient, a clinician can secure the bottom of the assembly by pressing down on base top  24 . Then the clinician can pull handle  18  up by applying force against handle bottom  50 . In addition, the clinician can also apply an upward force to an at least partially horizontal section of the needle or a connector to the needle. In the embodiment shown, this is the connector section  56  of needle  52 . The extent to which the needle is pulled is limited by the connectors, which are formed so that at the extreme upper limit, the pointed end  58  remains within needle well  22 . In this case, a bounce-back is confined within the needle well  22  and would not expose the clinician to pointed end  58 . Once extracted, needle guard  10  can be locked to prevent accidental reactivation of the needle. 
     FIG. 11  provides a prospective view of the needle assembly after the needle has been retracted from the patient. Note that the locks parts  38  and  40 , shown as latches, are locked, to secure connectors  14  and  16  in the upright position, so that pointed end  58  of needle  52  is secured withing either needle well  22  of base  12  or guide aperture  21  of guide  20  ( FIG. 8 ). In another embodiment (not shown), a separate clip is used to lock the connectors in a secured position. Optionally, needle cover  62 , whether integral with the needle guard  10  or as a separate piece, is reattached to cover well  22  as a further way of preventing the accidental exposure of pointed end  58  (not shown). 
   In  FIG. 12 , an embodiment of the needle guard assembly is shown, in which the needle is a substantially straight needle, with an integral connector  77 . In this case, guide  20  is attached to base bottom  26  of base  12 , to allow the needle to approach the patient at an angle other than a substantially perpendicular angle. To provide an added measure of safety, cap  78  is used to cover needle well  22  at guide  20 . In this embodiment, base  12  or a section thereof is optionally resilient so that guide  20  can be deformed into a non-perpendicular angle relative to the base. As demonstrated, various different needle types can be used with needle guards according to the invention. As a further example, a straight needle that is attached to a connector that forms an angle with the needle can also be used with the needle guard. 
   In a preferred embodiment, the needle guard is molded as an one-piece plastic part. However, different materials approved for medical devices may be used. In addition, different components of the needle guard may be made separately, then secured to one another. Although not shown, the guide may be merged into the base, such that the base provides a sufficiently long needle well to prevent the needle point from being accidentally exposed during retraction from the patient.