Abstract:
A shieldable winged needle assembly includes a hub and a cannula projecting distally beyond the hub. A spring is telescoped over the cannula and engages with or into distal portions of the hub. A hub guide projects radially out from the hub. A first wing includes a center sleeve rotationally mounted on the hub and axially movable along the hub when a slot formed in the center sleeve aligns with the hub guide. A second wing has proximal and distal sleeves mounted at opposite ends of the center sleeve. The proximal and distal sleeves each are rotationally mounted relative to the hub and each include slots that enable sliding movement of the hub guide when the slots of the second wing align with the slot of the first wing. The spring propels the cannula and hub into a shielding position when the slots of the wings are rotated into alignment with one another.

Description:
RELATED APPLICATIONS 
     This application claims priority on U.S. Provisional Patent Appl. No. 60/383,521 filed May 28, 2002. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to needle protection devices, and particularly a safety device for use with an intravenous infusion needle. 
     2. Description of the Related Art 
     A device commonly referred to as a “butterfly” or winged intravenous infusion assembly often is used for IV infusions and/or for withdrawing venous blood. This device also may be known as a hemodialysis needle. The device typically includes a needle hub with opposite proximal and distal ends and a passage extending between the ends. The device also includes a needle cannula with a proximal end, a sharply pointed distal end and a lumen extending between the ends. The proximal end of the needle cannula is securely mounted in the hub of the device so that the lumen through the needle cannula communicates with the passage through the hub. The device may further include a length of flexible plastic tubing with opposite proximal and distal ends. The proximal end of the tubing typically is mounted to a fitting, such as a luer fitting. The distal end of the tubing is mounted to the proximal end of the hub. Thus, communication is provided between the lumen of the needle cannula and the fitting at the proximal end of the flexible tubing. 
     The device is employed by placing the pointed distal end of the needle cannula in, communication with a blood vessel and placing the fitting at the proximal end of the flexible tubing in communication with a container that will be used to infuse a drug into the patient or to collect a specimen of blood from the patient. The needle may remain in communication with the patient for an extended time. Hence, it is common to tape the device to the skin of the patient to prevent a painful shifting of the needle relative to the patient. The needle cannula and the hub are very small. Accordingly, wings are provided to manipulate the needle cannula during insertion into the targeted blood vessel. The wings can be folded into face-to-face engagement with one another and gripped between a thumb and forefinger. Thus, the folded wings function as a handle to facilitate proper alignment of the needle cannula during insertion into the blood vessel. The wings then can be rotated into a substantially co-planar disposition and can be taped into face-to-face engagement with the skin of the patient. 
     Accidental sticks with a used needle cannula can transmit blood-borne diseases. Thus, some states mandate protection devices to reduce the risk of accidental sticks with a used needle cannula. A very effective needle protection device for IV infusion needles is marketed by Becton Dickinson and Company under the trademark SAFETY-LOCK™. Another safety needle protection system for IV infusion needles is marketed by Sherwood Medical Company and sold under the trademark ANGEL WING™. These systems require a user to grip the wings with one hand and the shield with the other hand. The hands then are moved relative to one another to retract the needle relative to the shield or to move the shield over the needle. Shielding may not be completed properly if the user forgets to perform the two-handed shielding operation or if the exigencies of the medical situation prevent the user from performing the two-handed shielding operation. Additionally, a potential exists that the user will not perform the manual shielding operation properly or completely. Hence, the used needle could be re-exposed prior to being discarded. 
     In view of the above, it is an object of the subject invention to provide a needle assembly that permits one-handed shielding of an IV infusion needle. 
     It is another object of the subject invention to provide an IV infusion needle assembly that permits shielding to be effected automatically as part of the process of removing the used needle cannula from the patient. 
     SUMMARY OF THE INVENTION 
     The subject invention relates to a medical device, such as an IV infusion set or blood collection set. For simplicity, the device will be referred to herein as an IV infusion set. The IV infusion set includes a needle assembly with a needle hub that has a proximal end, a distal end and a passage extending between the ends. External portions of the hub are provided with a guide. The guide may be a projection that extends in a direction transverse to the passage through the hub, and preferably is formed near the distal end of the hub. The hub may further include a generally cylindrical spring recess extending into the distal end of the hub at a location spaced outwardly from the passage and spaced inwardly from the outer surface of the hub. The needle assembly further includes a needle cannula having a proximal end, a sharply pointed distal end and a lumen extending between the ends. The proximal end of the needle cannula is mounted in the passage of the hub, and the pointed distal end of the needle cannula projects distally beyond the hub. 
     The IV infusion set may further include a length of flexible plastic tubing that has a proximal end, a distal end, and a passage extending between the ends. The proximal end of the flexible plastic tubing may be mounted securely to a fitting, such as a female luer fitting. The distal end of the flexible plastic tubing may be mounted to the proximal end of the hub. Thus, the lumen through the needle cannula communicates with the fitting at the proximal end of the flexible plastic tubing. 
     The needle assembly further includes first and second wings. The first wing includes a generally planar panel and a center sleeve that is mounted over the hub for both rotational movement and axial sliding movement. The center sleeve has opposite proximal and distal ends and a longitudinal slot extending continuously between the ends. The slot may extend completely through the wall of the sleeve to define a split tube. However, the slot also can be formed only in the inner circumferential surface of the sleeve, and hence may be more in the nature of a groove. The slot defines a circumferential dimension or width that is equal to or slightly greater than the circumferential dimension of the projection on the hub. Thus, the projection on the hub can slide longitudinally through the slot on the center sleeve when the slot of the center sleeve is aligned rotationally with the projection on the hub. However, the center sleeve and the hub are fixed longitudinally relative to one another when the slot in the center sleeve is rotationally offset from the projection on the hub. 
     The second wing includes proximal and distal components that are assembled to one another and securely connected after assembly. The proximal component of the second wing includes a generally planar proximal panel and a proximal sleeve that is telescoped over proximal portions of the hub and over distal portions of the flexible tubing. The proximal sleeve is dimensioned and configured for rotational movement about the hub and for longitudinal movement relative to the hub. The proximal sleeve may further include a longitudinally extending slot with a circumferential dimension or width that exceeds circumferential dimension or width of the projection on the hub. The slot in the proximal sleeve may extend completely through the wall of the sleeve in a radial direction or may be a groove in the inner circumferential surface of the sleeve. However, the slot in the proximal sleeve preferably extends only from the distal end of the proximal mounting sleeve to a location between the proximal and distal ends thereof. The length of the slot in the proximal sleeve is equal to or greater than the axial length of the projection on the hub. 
     The distal component of the second wing includes a distal panel and a distal sleeve. The distal panel is dimensioned and configured to mate with the proximal panel. The distal sleeve is dimensioned to mount over the distal end of the hub and over portions of the needle cannula. The distal sleeve further includes a longitudinally extending slot that is wider than the projection of the hub. The slot in the distal sleeve may extend completely through the wall of the sleeve or may be a groove in the inner circumferential surface of the sleeve. The slot in the distal sleeve extends from the proximal end of the distal sleeve to a location between the proximal and distal ends, and has an axial length that exceeds the axial length of the projection on the hub. 
     The second wing is assembled such that the proximal and distal sleeves are disposed respectively at the proximal and distal ends of the center sleeve of the first wing. Additionally, the slots in the proximal and distal sleeves align with one another and can both be placed in alignment with the slot of the center sleeve by appropriate rotation of the first and/or second wings relative to one another. 
     The needle assembly may further include a spring disposed between the hub and at least one of the sleeves. The spring is operative to bias the hub proximally relative to the wings. 
     The wings of the needle assembly initially may be in a substantially coplanar disposition with the hub and needle cannula advanced into an extreme distal position relative to the wings. In this position, the projection of the hub is disposed in the slot in the distal sleeve and the spring is in a biased condition. The slot in the center sleeve is offset rotationally from the slot in the distal sleeve. Hence, the projection is prevented from moving through the slot in the center sleeve, and the needle cannula is retained in a position projecting distally beyond the wings. 
     The needle assembly of the IV infusion set may be used by rotating the wings upwardly and toward one another so that the wings may function as a convenient handle to be gripped between a thumb and forefinger. This rotational movement of the wings toward one another may rotationally displace the slot in the center sleeve further from the slot in the distal sleeve. Hence, the projection of the hub remains trapped distally of the center sleeve and the needle cannula remains projected distally beyond the wings. The needle cannula then is guided into a targeted blood vessel of a patient. The wings then may be rotated back into their coplanar disposition and may be taped in substantially face-to-face engagement with the skin of the patient. 
     Upon completion of the medical procedure, the needle cannula is withdrawn from the patient and the wings are rotated down and toward one another. This rotational movement of the first and second wings down and toward one another moves the slot of the center sleeve into alignment with the projection on the hub. As a result, the spring biases the hub proximally and causes the projection of the hub to move proximally through the slot of the center sleeve and into the slot of the proximal sleeve. This proximal movement of the hub by the spring causes the needle cannula to be retracted safely within the sleeves of the first and second wings. The spring maintains its biasing force to keep the needle cannula in the safely shielded position. Additionally, further downward rotation of the wings may move the slot of the center sleeve beyond the projection of the hub. Thus, the center sleeve retains the projection in the slot of the proximal sleeve and holds the needle cannula in the shielded position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view of an IV infusion set in accordance with the subject invention. 
         FIG. 2  is an exploded perspective view of the wings as seen from the front. 
         FIG. 3  is an exploded perspective view of the wings as seen from the rear. 
         FIG. 4  is a perspective view of the needle assembly and tubing in an assembled condition and with the needle cannula projecting in a ready-to-use position. 
         FIG. 5  is a top plan view of the needle assembly shown in FIG.  4 . 
         FIG. 6  is a cross-sectional view taken along line  6 — 6  in FIG.  5 . 
         FIG. 7  is a perspective view showing movement of the wings toward one another after use of the IV infusion set. 
         FIG. 8  is a perspective view similar to  FIG. 7 , but showing the wings rotated into a position to generate shielding of the needle cannula. 
         FIG. 9  is a cross-sectional view taken along line  9 — 9  of FIG.  8 . 
         FIG. 10  is a perspective view similar to  FIG. 8 , but showing the needle cannula in a partly shielded condition. 
         FIG. 11  is a cross-sectional view taken along line  11 — 11  of FIG.  10 . 
         FIG. 12  is a perspective view similar to  FIG. 10 , but showing the needle cannula in the fully shielded position. 
         FIG. 13  is a cross-sectional view taken along line  13 — 13  in FIG.  12 . 
     
    
    
     DETAILED DESCRIPTION 
     An IV infusion set or blood collection set in accordance with the subject invention is identified generally by the numeral  10  in  FIGS. 1 ,  10  and  12 , and for simplicity will be referred to herein as an IV infusion set. IV infusion set  10  includes a needle assembly  12 , a length of flexible plastic tubing  14  and a fitting  16 . Flexible tubing  14  includes a proximal end  18  and a distal end  20 . Proximal end  18  of flexible plastic tubing  14  is secured to fitting  16 . As illustrated herein, fitting  16  is a female luer fitting that communicates with the passage through tubing  14 . However, other fittings may be employed, such as a non-patient needle assembly or a luer-activated device port. 
     Needle assembly  12  includes a hub  22  that is formed unitarily from a transparent plastic material, such as polypropylene. Hub  22  includes a proximal end  24 , a distal end  26  and a passage  28  extending between the ends. Distal end  20  of tubing  14  is mounted securely to proximal end  24  of hub  22  so that passage  28  through hub  22  communicates with the passage through tubing  14  and with fitting  16 . A projection  30  projects unitarily out from outer circumferential surface of hub  22  substantially adjacent distal end  26  thereof. Projection  30  defines a circumferential dimension or width “a” and a length “b” as shown in FIG.  1 . Distal end  26  of hub  22  is characterized further by a generally cylindrical spring recess  32  that is spaced outwardly from passage  28  and inwardly from projection  30 , as shown in FIG.  6 . 
     Needle assembly  12  also includes a coil spring  34  with a proximal end  36  and a distal end  38 . Proximal end  36  of spring  34  is telescoped into spring recess  32  of hub  22 . Spring  34  is dimensioned so that distal end  38  of spring  34  projects distally beyond hub  22  in an unbiased condition of spring  34  when proximal end  36  of spring  34  is mounted against the proximal end of spring recess  32 . 
     Needle assembly  12  further includes a cannula  40  having a proximal end  42 , a pointed distal end  44  and a lumen  46  extending between the ends. Proximal end  42  of cannula  40  is mounted securely in passage  28  of hub  22  so that pointed distal end  44  of cannula  40  projects distally beyond hub  22 . As a result, lumen  46  of cannula  40  communicates with passage  28  of hub  22 , with the passage through tubing  14  and with fitting  16 . 
     Needle assembly  12  further includes first and second wings  48  and  50 , as shown most clearly in FIG.  4 . First wing  48  includes a panel  52  and a generally cylindrical center sleeve  54 . Center sleeve  54  includes a proximal end  56 , a distal end  58  and a slot  60  extending continuously between ends  56  and  58 . Slot  60  is symmetrical with a diametric plane of center sleeve  54  that is coplanar with or parallel with panel  52 . Slot  60  defines a width “c” that exceeds the width “a” of projection  30 . Additionally, center sleeve  54  has an axial passage  61  with an inside diameter that exceeds the outside diameter of hub  22 . Thus, center sleeve  54  can be telescoped axially over hub  22  by aligning slot  60  of center sleeve  54  with projection  30 . Wing  48  can be rotated relative to hub  22  when center sleeve  54  is displaced axially from projection  30 . 
     Center sleeve  54  preferably is substantially rigid to ensure secure mounting over hub  22  and efficient rotational and axial movement relative to hub  22 . However, other portions of first wing  48  need not be rigid, and particularly center portions of panel  52  and lower surface regions of panel  52  conveniently are formed from a less rigid material. Thus, first wing  48  preferably is formed by a co-molding process where at least center sleeve  54  is formed from a rigid relatively stiff material and at least portions of panel  52  are formed from an elastomeric material. This co-molding may be achieved by initially forming center sleeve  54  and then over-molding at least portions of panel  52  over a connecting portion of center sleeve  54 . Center sleeve  54  may be formed from polypropylene, whereas at least portions of panel  52  are formed from a thermoplastic elastomer, such as polyolefin, santoprene or soft PVC. Additionally, center sleeve  54  preferably is formed from a transparent plastic material to provide a clear indication of flashback as explained further herein. 
     Second wing  50  is formed from a proximal wing component  62  and a distal wing component  64  that are fused, sonically welded or adhered to one another. Proximal wing component  62  includes a proximal panel  66  and a proximal sleeve  68 . Proximal sleeve  68  is formed from a rigid plastic material, such as polypropylene. Proximal panel  66  preferably is co-molded with proximal sleeve  68  and preferably is formed from a thermoplastic elastomer, as explained with respect to first wing  48 . Proximal sleeve  68  is generally tubular and includes a proximal end  70 , a distal end  72  and a cylindrical passage  74  extending between the ends. Passage  74  defines an inside diameter substantially equal to the inside diameter of passage  61  through center sleeve  54 . Proximal sleeve  68  is characterized by a slot  76  that extends from distal end  72  of proximal sleeve  68  to a location between proximal and distal ends  70  and  72  of proximal sleeve  68 . Slot  76  is symmetrical with a diametric plane of proximal sleeve  68  that is aligned substantially orthogonal to proximal panel  66 . Slot  76  of proximal sleeve  68  has a circumferential dimension or width slightly greater than width “a” of projection  30  of hub  22  and a length slightly greater than length “b” of projection  30 . 
     Distal wing component  64  includes a distal panel  78  and a distal sleeve  80 . The distal wing component  64  is formed similar to proximal wing component  62 , with distal sleeve  80  being formed from a substantially rigid material and at least portions of distal panel  78  being formed from a thermoplastic elastomer. Distal sleeve  80  includes a proximal end  82 , a distal end  84  and a passage  86  extending between the ends. Portions of passage  86  adjacent proximal end  82  define an inside diameter slightly greater than the outside diameter of hub  22 . However, portions of passage  86  adjacent distal end  84  define a diameter much smaller than the outside diameter of hub  22  and slightly greater than the diameter of cannula  40 . Distal sleeve  80  is characterized by a slot  88  extending from proximal end  82  partway toward distal end  84 . Slot  82  is symmetrical about a plane aligned orthogonal to distal panel  64 . Additionally, slot  82  defines a width slightly greater than the width “a” of projection  30  on hub  22  and a length slightly greater than length “b” of projection  30 . 
     IV infusion set  10  may be assembled by adhering or fusing distal end  20  of tubing  14  to proximal end  24  of hub  22 . Additionally, proximal end  42  of cannula  40  is adhered, fused or otherwise secured in passage  28  through hub  22 . The affixation of cannula  40  to hub  22  is carried out so that the bevel at distal end  44  of cannula  40  and projection  30  of hub  22  are symmetrical about a common plane and face the same radial direction. Assembly proceeds by telescoping spring  34  over cannula  40  and inserting proximal end  36  of spring  34  into spring recess  32  of hub  22 . Thus, distal end  38  of unbiased spring  34  projects distally beyond spring recess  32 . 
     Center sleeve  54  of first wing  48  then is telescoped in a proximal-to-distal direction over tubing  14  and over proximal end  24  of hub  22 . This mounting is carried out with slot  62  rotationally offset from projection  30 . Hence, the proximal-to-distal movement of center sleeve  54  will terminate when distal end  56  of center sleeve  54  abuts projection  30 . Proximal wing component  62  then is telescoped over tubing  14  and over proximal end  24  of hub  20 . The proximal-to-distal movement of proximal wing component  14  terminates when distal end  72  of proximal sleeve  68  abuts proximal end  58  of center sleeve  54 . 
     Assembly proceeds by telescoping distal wing component  64  in a distal-to-proximal direction over cannula  40  and onto distal end  26  of hub  22 . Distal wing component  64  is rotationally aligned so that projection  30  of hub  22  nests into slot  88  of distal sleeve  80 . Proximal wing component  62  then is rotated relative to distal wing component  64  so that proximal panel  66  is coplanar with distal panel  78 . Proximal and distal panels  66  and  78  are provided with mating pins and apertures to facilitate their alignment and positioning. In their aligned position, slot  82  of distal sleeve  80  aligns with slot  76  of proximal sleeve  68 . Proximal and distal wing panels  66  and  78  then are fused together in a substantially coplanar disposition with slots  76  and  88  permanently aligned with one another. In this connected condition, spring  34  is compressed axially and hence maintains stored energy. Fitting  16  then is secured to proximal end  18  of tubing  14 . Assembly may be completed by mounting a packaging cover (not shown) over cannula  40  and maintaining the packaging cover releasably in position by frictional engagement with distal sleeve  80  or by appropriate use of a tamper evident tape. 
     Panel  52  of first wing  48  initially is disposed in substantially coplanar relationship to panels  66 ,  78  of second wing  50 . In this position, slot  60  of center sleeve  54  is approximately 90° offset from projection  30  on hub  22  and from slots  76  and  88  on proximal and distal sleeves  68  and  80  of second wing  50 . Hence, projection  30  effectively is trapped between distal end  56  of center sleeve  54  and the distal end of distal sleeve  80 . Accordingly, distal end  44  of cannula  40  projects distally beyond distal sleeve  80 . 
     IV infusion set  10  may be used by connecting fitting  16  to an appropriate container that has a fluid that will be infused into a patient or a container for receiving a fluid specimen to be drawn from the patient. Panel  52  of first wing  48  and panel  66 ,  78  of second wing  50  then are rotated upwardly toward one another and into substantially face-to-face relationship. This upward rotation of first and second wings  48  and  50  causes slot  60  of center sleeve  54  to rotate into a position displaced approximately 180° from projection  30  of hub  22 . Hence, projection  30  remains trapped in slot  88  of distal sleeve  80 . The medical practitioner then removes the packaging cover from cannula  40  and guides pointed distal end  44  of cannula  40  into a targeted blood vessel. The disposition of needle cannula  40  ensures that the bevel at distal end  44  faces up for convenient guiding into the targeted blood vessel. Access to the blood vessel can be confirmed by the flashback evident in passage  28  as seen through the transparent plastic of hub  22  and of center sleeve  54 . The medical practitioner then may rotate wings  48  and  50  away from one another so that panels  52 ,  66  and  78  lie in substantially face-to-face engagement with the skin of the patient. The panels may be taped in this mounted position. 
     Upon completion of the medical procedure, the user withdraws cannula  40  from the patient and urges panel  52  of first wing  48  and panel  66 ,  78  of second wing  50  downwardly and toward one another. As the wing panels  52  and  66 ,  78  approach perpendicular alignment with one another, slot  60  of center sleeve  54  moves into alignment with projection  30  of hub  22 . As a result, stored energy in spring  34  will urge hub  22  proximally relative to wings  48  and  50  and through slot  60  of center sleeve  54 . Thus, distal end  44  of cannula  40  will retract into distal sleeve  80  of second wing  50 . Once projection  30  enters slot  76  of proximal sleeve  68 , slot  60  will permit further downward rotation of wings  48  and  50  toward one another. Thus, slot  60  will be displaced rotationally from projection  30 , and center sleeve  54  will hold projection  30  in slot  76  of proximal sleeve. IV infusion assembly  10  then may be discarded in a sharps receptacle with cannula  40  safely retracted. 
     Although not shown, slot  76  in proximal sleeve  68  may be formed with one or more locking detents. The locking detents may include a distal inclined face and a proximal locking face. Spring  34  will guide projection  30  over the inclined distal face of the locking detent. However, projection  30  then will be trapped behind the proximal locking face of the locking detent. Alternatively, spring fingers or detents may be formed on wings  48  and  50 . The spring fingers or detents may be disposed and configured to prevent wings  48  and  50  from returning to a position where cannula  40  can be re-exposed. 
     As an alternative to the embodiment described and illustrated above, slot  60  of center sleeve  54  may be disposed to align with projection  30  when first panel  52  is substantially coplanar with second panel  66 ,  78 . With this embodiment, spring  34  must be selected to exert forces that are less than frictional forces between cannula  40  and the tissue of the patient. This embodiment is employed substantially as described above by initially holding wings  48  and  50  in face-to-face engagement with one another for insertion of cannula  40  into the patient. Wings  48  and  50  then will be rotated away from one another and into a substantially coplanar disposition adjacent the skin of the patient. This alignment of wings  48  and  50  will dispose slot  60  in a rotational position aligned with projection  30 . However, the frictional forces on cannula  40  will hold cannula  40  and hub  22  in at least a partly extended position. The frictional forces on cannula  40  will gradually reduce as cannula  40  is being withdrawn from the patient. As a result, spring  34  will exert sufficient forces to propel hub  22  and cannula  40  proximally and into a position where cannula  40  is safely shielded. 
     The preceding embodiment relates to automatic shielding initiated merely by an appropriate rotational alignment of wings  48  and  50  and the driving force of spring  34 . However, a manually shieldable spring-assisted version of the invention can be provided merely by removing spring  34  and/or extending projection  30  sufficiently to project through the slots of the sleeves of the wings. Thus, shielding can be effected by rotating the wings into a position where the slots align with one another and then manually moving the projection in a proximal direction to effect shielding. 
     The preceding embodiments show the slots  60 ,  76  and  88  defining widths that are substantially equal to one another and slightly greater than the width “a” of projection  30 . However, the slots  60 ,  76  and  88  need not be of equal widths. For example, slot  76  of proximal sleeve  68  may be wider than slot  88  of distal sleeve  80  to facilitate entry of projection  30  into slot  76 . Additionally, slot  60  of center sleeve  54  may be significantly wider than slot  88  of distal sleeve to increase the range of angular positions at which shielding will commence. Thus, shielding will commence at any of a range of angular orientations, and not merely at a single rotational orientation of wings  48  and  50 . These and other variations will be apparent to a person skilled in this art after having read the subject disclosure.