Abstract:
A telescopic intravenous infusion set and/or blood collection assembly is provided with a safety feature for covering the used needle. The safety feature is a telescopic device including a shield with handling wings, which when placed in cooperating relationship, allows accommodation of a conventional unmodified blood collection needle affixed to a hub, and a sleeve with a locking cap. After use, the hub with the needle are pulled rearwardly into positive locking position which prevent the hub and needle from moving out of the shield thereafter. The telescopic nature of the device then allows the locked needle/hub to move rearward in relation to the shield until the shield is unreleasably locked to the sleeve. The shield provides for passage of the needle and hub from a releasable locked use position to a shielded and unreleasable locked protected position.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a winged safety needle assembly and, more particularly, to a telescopic winged safety needle assembly having a winged cylindrical sheath for preventing sticking accidents from taking place when retracting the needle into the winged cylindrical sheath. Protection of the edge of the needle is achieved by unlocking and sliding the needle along the inner wall of the winged cylindrical sheath and a sleeve.  
         [0003]     2. Discussion of the Related Art  
         [0004]     Needlestick injuries are intended to be avoided by proper disposal of needles. Used needles may be recapped with the same cover that originally covered the needles before use or by similar covers or tubes before the needle is discarded. This method requires movement of the hands toward the exposed needle and may promote needlestick injuries during the recapping. In addition, needles may also be disposed of by tossing them into nearby refuse containers. However, this creates danger to those who handle the refuse containers.  
         [0005]     Winged intravenous (IV) sets are well known in the art. A typical prior art IV butterfly needle used for the insertion into blood vessels and similar passageways in the body to permit the infusion or withdrawal of sterile fluids or blood is illustrated in  FIG. 8 . The butterfly needle generally has a hollow needle or cannula  30 , a cylindrical hub  20  holding the needle  30  at one end and connected to an IV tube  52  at the opposite end, and a cylindrical housing  10  surrounding the needle with a wing-like extension  50  extending on each side thereof.  
         [0006]     The wings  50  are used to handle the assembly during insertion and withdrawal. For example, the wings of the needle assembly may be folded upwards around the hub to provide a gripping extension for the technician or nurse to use when attempting to insert the needle into the desired vein, artery or other passageway. The wings are also used to stabilize the device while in place by providing a broad surface area of contact with the patient which allows for taping of the device to the patient while discouraging movement, especially rotation, of the device. This assists the technician or nurse in affixing the needle to the patient during the infusion of fluids or medicants.  
         [0007]     A problem typical of butterfly needles as just described is that when the needle is withdrawn from the vein or artery, the sharpened end, now contaminated with blood or other body fluid, remains exposed. The exposed needle can be a source of great danger to the operator or to anyone who might be pricked or scratched. Needle injuries may result in the transmission of diseases such as hepatitis, HIV, or cause other types of infection. A common solution available to the operator was to simply drop the needle and its holder into a trash receptacle. However, a danger to clean up and medical waste disposal personnel continues if the used needles are not rendered harmless in some way. Another solution is to attempt to recap the needle with a safety cover immediately after use. This, however, may in itself cause injury if the operator should accidentally stick themselves during the recapping process. In addition, caps or covers may come loose and expose the used needle.  
         [0008]     Therefore, in order to prevent such sticking accidents various proposals have been made. One such proposal is a winged needle assembly disclosed in U.S. Pat. No. 5,505,711 (hereinafter referred to as the &#39;711 patent). The &#39;711 patent describes an indwelling injector needle assembly having wings including a cannula or needle body, a hub supporting a proximal end of the needle body, a tube in fluid communication with the needle body, a cylindrical holder having a distal end from which the wings protrude, and a latching mechanism. The hub can slide along an inner periphery of the holder between a first position near the distal end of the holder and a second position near a proximal end of the holder. The latching mechanism is formed in and disposed between the hub and the holder so that the hub is inhibited from moving from the first position toward the second position, and vice versa. The needle edge can be retracted within the holder while its wings remain fixed to a patient&#39;s skin.  
         [0009]     However, the winged needle assembly disclosed in &#39;711 patent has several disadvantages. Use of a safety needle assembly with a longer overall length (e.g., 55 mm) results in unnecessary damage to a vessel in which the needle has been inserted. This is due to the fact that any accidental movement of an exposed hub, holder, or sheath is likely to result in unnecessary damage to a vessel from the needle. In addition, the use of a longer overall length safety needle assembly requires a larger radius loop of a profusion tube connected to the safety needle assembly which is ultimately secured (taped) to the patient, i.e., a longer assembly requires a larger loop of tubing to prevent kinking of the tube. A smaller loop of tubing helps prevent accidental movement of the assembly. The &#39;711 Patent also discloses a non-rotating needle. Therefore the needle cannot be rotated when needed after cannulation in order to maximize blood or fluid flow to or from the vessel.  
         [0010]     Therefore, what is needed is a telescopic winged safety needle device that provides a maximum overall length for ease of handling during insertion of the needle into a vessel, and a minimum overall length while being secured to a patient to prevent damage to the vessel. In addition, a minimized overall length of a device while being secured to a patient allows a loop of tubing to be kept to a minimum radius and secured to the patient without introducing a kink in the tube. Also, a winged safety needle device is needed that allows for rotation of the needle after cannulation in order to maximize blood or fluid flow to or from the vessel.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  illustrates an exploded view of the Telescopic Safety AVF needle according to an embodiment of the present invention;  
         [0012]      FIG. 2  illustrates a locked insertion position of the Telescopic Safety AVF needle according to an embodiment of the present invention;  
         [0013]      FIG. 3  illustrates an initial retrieved position of the Telescopic Safety AVF needle according to an embodiment of the present invention;  
         [0014]      FIG. 4  illustrates a final locked position of the Telescopic Safety AVF needle according to an embodiment of the present invention;  
         [0015]      FIG. 5  illustrates a cannulation procedure of the Telescopic Safety AVF needle according to an embodiment of the present invention;  
         [0016]      FIG. 6   a  illustrates a cross-section view of a sleeve according to an embodiment of the present invention;  
         [0017]      FIG. 6   b  illustrates three cross-section views of a hub moving relative to a sleeve according to an embodiment of the present invention;  
         [0018]      FIG. 6   c  illustrates a cross-section view of a sleeve and a hub in a locked position according to an embodiment of the present invention;  
         [0019]      FIG. 7   a  illustrates a first view showing an orientation of a cannula bevel according to an embodiment of the present invention;  
         [0020]      FIG. 7   b  illustrates a second view showing an orientation of a cannula bevel according to an embodiment of the present invention; and  
         [0021]      FIG. 8  illustrates a prior art intravenous butterfly needle.  
     
    
     DETAILED DESCRIPTION  
       [0022]     The Telescopic Safety Arteriovenous Fistula (AVF) needle assembly  100  as shown in  FIG. 1 , is a telescopic retractable winged safety needle device having a needle holder  110  (hereinafter referred to as a “hub”), a needle or cannula  120 , a winged sheath  130 , and a sleeve  140 . Referring to  FIGS. 1, 2 ,  3 , and  4 , the hub  110  may be tubular in shape and may be made of a polycarbonate or other polymeric material. The hub  110  secures a proximal end of the needle or cannula  120  at the distal end. The needle or cannula  120  is hollow, has a beveled edge  121  at the distal end, and may be made of stainless steel. The base  122  or proximal portion of the hollow needle  120  is fixed to and supported by the hub  110 . A tube, for example a polyvinyl chloride (PVC) tube  150 , is slid over the proximal end of the hub  110 , providing a fluid tight seal. The hub  110  has a stopper  115  at the proximal end for tube  150  bonding. The winged sheath  130  and sleeve  140  are axially slideable on the hub  110  to form a telescopic union of the three pieces.  
         [0023]     The hub  110  also has two large diameter portions, a first annular ring  111  and a second annular  112 , a second groove  114  near the distal end, and a first groove  113  at the proximal end.  
         [0024]     The winged sheath  130  is a cylindrical structure with a hollow interior. The winged sheath  130  may be made of a polyethylene material. The winged sheath  130 , which is axially slideable on the hub  110 , has a constant inner diameter (defining the hollow interior). At the distal end of the sheath, a pair of wings  131  are positioned for use in grasping the device when squeezed together for cannulation into the patient&#39;s skin (see  FIG. 5 ) and for adhering the device to a patient&#39;s skin during infusion, haemodialysis, apheresis, and blood collection when laying flat. The wings may be adhered to a patient using, for example, medical tape. The flexible wings  131  are integrally formed with the body of the supporting cylinder of the winged sheath  130  on both sides thereof, and the shape of the wings  131  is not particularly limited. The wings  131  are preferably provided on the cylinder body to form one plane as shown in  FIG. 1 - FIG. 5 .  
         [0025]     Referring to  FIG. 1  and  FIG. 2 , the sheath  130  has two rear lugs  132 ,  133  located on each of the top and bottom of the exterior surface at the proximal end. A notch  134  is formed between the rear lugs  132 ,  133 . Also at the proximal end of the sheath  130 , distal of the rear lugs  132 ,  133  there is an opening  138  for receiving a protrusion  147  of a locking tab  145  attached to the sleeve  140  that can be selectively placed in a locked or unlocked position. The locking tab  145  has a hinge  146  attached to the side of the sleeve  140  so that when in an unlocked position, it stays attached thereto. The locking tab  145  utilizes the protrusion  147  that fits into an opening  148  in the sleeve  140  and in the opening  138  in the sheath  130  when the locking tab  145  is in the locked position. The protrusion  147  extends into the first groove  113  of the hub  110  to prevent movement of the sleeve  140  and sheath  130  with respect to the hub  110 .  
         [0026]     In the insertion position (see  FIG. 2 ), the needle  120  is exposed through the distal end of the sheath  130  and is held in this position when the protrusion  147  of the locking tab  145  engages the first groove  113  in the hub  110  through the opening  148  in the sleeve  140  and the opening  138  in the sheath  130 . In the insertion position the telescopic relationship of the sheath  130 , sleeve  140 , and hub  110  is such that the overall length of the Telescopic Safety AVF device  100  is minimized (e.g., 38 mm overall length). This minimized length prevents unnecessary damage to the vessel in which the needle  120  has been inserted. This is due to the fact that any accidental movement of the exposed hub  110 , sleeve  140 , and sheath  130  is likely to be reduced because of the overall reduced length of such an assembly relative to a longer length prior art safety needle device (e.g., 55 mm). In addition, the use of a minimized length also allows a minimized radius loop of the PVC tube  150  which is ultimately secured (taped) to the patient, i.e., a longer device requires a larger loop of tubing to prevent kinking of the tube. A smaller loop of tubing helps prevent accidental movement of the device. Therefore, a loop of PVC tube  150  may be kept to a minimum radius and secured to the patient without introducing a kink in the tube.  
         [0027]     Referring to  FIG. 3 , when the needle  120  is to be withdrawn from the patient, any tape securing the wings  131  to the patient is removed. The technician then places his/her index finger against a notch  139  to hold the sheath  130  against the patient. The locking tab  145  of the sleeve  140  is disengaged and the hub  110  with the attached needle  120  are pulled in a proximal direction relative to the sheath  130  and sleeve  140  (which are no longer locked together) until the second large diameter portion (second annular ring)  112  of the hub  110  is pulled to the proximal end of the sleeve  140  and abuts against three inner ribs  151  located 120 degrees apart around the inner proximal surface of the sleeve  140 .  
         [0028]     Referring to  FIG. 6   a  and  FIG. 6   b,  as the first groove  113  moves in a proximal direction toward the rear lug  144 , the hub  110  surface on either side of the first groove  113  is supported by the three inner ribs  151 . This allows the hub  110  to pass smoothly through the proximal portion of the sleeve  140 . As the first groove  113  passes through the proximal end of the sleeve and under the rear lug  144 , the 3 inner ribs  151  prevent the first groove  113  from engaging the rear lug  144 .  
         [0029]     As the hub  110  continues to be drawn in the proximal direction, the sleeve  140  is now also drawn in the proximal direction due to the abutment of the second annular ring  112  with the three inner ribs  151 . It should be noted that the second annular ring  112 , which is aligned next to but proximal of the first annular ring  111  on the hub  110 , includes a sloped surface that tapers in the proximal direction.  
         [0030]     The hub  110  is drawn in the proximal direction until the sheath  130  is engaged in a final locking position in which the sheath  130  becomes unreleasably locked to the sleeve  140 . The two rear lugs  132 ,  133  located on each of top and bottom of the exterior surface of the sheath  130  at the proximal end unreleasably lock with a corresponding pair of distal inner circumferential rings, interior first annular ring  142  and interior second annular ring  143 , that protrude from the inner distal surface of the sleeve  140 . The most proximal top and bottom lugs  133  seat in a corresponding top and bottom pair of openings  149  in the sleeve  140 .  
         [0031]     Next, referring to  FIG. 4  and  FIG. 6   c,  the hub  110  continues to be drawn in the proximal direction relative to the sheath  130  (locked to the sleeve  140 ) until the hub  110  unreleasably locks to the sleeve  140 . A sharp angle shaped rear lug  144  of the sleeve  140  allows the second annular ring  112  to pass out of the sleeve  140  before the rear lug  144  seats in the second groove  114  of the hub  110 . The sloped surface of the second annular ring  112  (that tapers in the proximal direction) in conjunction with the sharp angle shaped rear lug  144  of the sleeve  140  facilitates the passage of the second annular ring  112  out of the sleeve  140 . The sharp angle shape of the rear lug  144  is such that the second annular ring  112  cannot re-enter the sleeve  140  past the rear lug  144 . In fact, if the hub  110  is pushed in the distal direction relative to the sleeve  140 , the contact between the second annular ring  112  (the distal perpendicular side of the second annular ring  112 ) and the sharp angle shaped rear lug  144  of the sleeve  140  will tend to cause the angle shaped rear lug  144  to curve inward, i.e., bend from being pushed by the second annular ring  112 . Therefore, the rear lug  144  will grip onto the second groove  114  to further prevent the hub  110  and cannula  120  from moving distally out of the sleeve  140 .  
         [0032]     The needle  120  has now been withdrawn from the patient. Also note that the locking tab  135  is used only for maintaining the locked relationship between the sheath  130  and hub  110  in the insertion position and not in the protection position.  
         [0033]     Referring to  FIG. 7   a  and  FIG. 7   b,  the Telescopic Safety AVF needle assembly  100  also includes a rotational feature that allows the hub  110  with attached needle or cannula  120  to rotate 360 degrees within the winged sheath  130 . This feature allows the cannula bevel  121  orientation within the fistula or graft to be adjusted and ascertained. A black dot mark on the distal exterior surface of the hub  110  is visible when facing up (see  FIG. 7   a ) and indicates the cannula bevel  121  is facing up within the fistula or graft. Alternatively, a red dot mark on the distal exterior surface of the hub  110  is visible when facing up (see  FIG. 7   b ) and indicates the cannula bevel  121  is facing down within the fistula or graft. Therefore, the handling of the Telescopic Safety AVF needle assembly  100  of the present invention is simplified, since after inserting the needle  120  with the beveled surface  121  facing up into a blood vessel (the black dot on the distal exterior surface of the hub  110  is visible when facing up as shown in  FIG. 7   a ), the beveled edge  121  is then made to face down by simply rotating the hub  110  until the red dot on the distal exterior surface of the hub  110  is visible when facing up and the needle  120  is then retained in that state (see  FIG. 7   b ). The ability to adjust the orientation (0-360 degrees) of the cannula bevel  121  within a vessel allows a technician to adjust for maximum fluid flow.  
         [0034]     In contrast, some prior art winged retention needles have the disadvantage that the operation thereof is troublesome, since a hollow needle is directly fixed to a winged portion with the edge surface faced up and accordingly the edge surface must be faced down by a half rotation of the entire winged needle assembly after insertion into blood vessels.  
         [0035]     While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of the present invention. The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.