Abstract:
A system includes a needle for aspirating fluid. A holder supports the needle and a guard is moveable to selectively cover the needle. Initially, a cantilevered tab on the guard is moved into a stressed configuration, and a distally directed force on the guard presses the tab into contact with an abutment on the holder. This prevents further distal movement of the guard. Subsequently, in response to a proximally directed force, the tab is released from the abutment, it returns to a passive, unstressed configuration, and the guard moves to expose the needle for aspiration. Thereafter, when the proximally directed force on the guard is removed, the guard is urged into a final, locked position where it covers the distal end of the needle and protects the needle.

Description:
FIELD OF THE INVENTION 
     The present invention pertains generally to fluid collection systems. More particularly, the present invention pertains to fluid aspiration systems that are useful for collecting blood. The present invention is particularly, but not exclusively, useful as a blood collection system having an automatically activated guard that covers the needle to protect users from accidental “sticks” after blood has been collected. 
     BACKGROUND OF THE INVENTION 
     Any use of a needle requires careful handling and the exercise of caution. The main purpose for this, of course, is to protect against inadvertent “sticks” that can cause injury and may transmit diseases. Such care is particularly important when the needle is a hypodermic needle and is being used as an injection or aspiration needle in blood transfer, or blood collection procedures. In addition to careful handling of a needle, the safety of a needle procedure can be enhanced if the needle can be effectively covered whenever it is not being used. 
     Heretofore, several different types of safety systems have been disclosed which are designed for both ease of use and protection of the user. Typically, these systems incorporate automatic features that help minimize the manipulation required to effectively use a needle in a procedure. For example, U.S. Pat. No. 6,379,336 which issued to Asbaghi et al. for an invention entitled “Protective Device for Injection or Aspiration Needle”, and which is assigned to the same assignee as the present invention, discloses a system that automatically locks a guard over a needle after its use. 
     For the specific application wherein a needle system is used for blood collection, there is no need for the needle system to be somehow prepared before it is to be used. For instance, in a blood collection procedure there is no need to pre-fill a syringe with medication, or to otherwise uncover and prepare the needle prior to its use. Consequently, an aspiration needle is preferably ready for use at any time. After its use, however, when there is no longer a need for the needle, it is desirable for the needle to be permanently covered to protect the user, and others, from accidental sticks. 
     In light of the above, it is an object of the present invention to provide a safety system for a blood collection device that has an automatic, ready-to-activate, needle guard for covering and protecting the needle after its use. Another object of the present invention is to provide a safety system for a blood collection device that automatically locks the needle guard in place after the needle has been used. Yet another object of the present invention is to provide a safety system for a blood collection device that is simple to manufacture, is easy to use and is comparatively cost effective. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, a safety system for a blood collection device includes a tubular shaped holder and a tubular shaped guard. The holder and guard then interact with each other to protect the needle of the device after it has been used. Structurally, the holder defines a longitudinal axis, and it has an inner surface that surrounds a lumen. A distal abutment and a proximal abutment are formed on the inner surface of the holder, along with a plurality of longitudinally oriented ribs. More specifically, the ribs individually extend from the inner surface of the holder and each rib is formed with a detent. Using this arrangement, the needle is mounted on an adapter, and the adapter is affixed to the ribs by a snap engagement with the respective detents. This aligns the needle along the axis of the holder. 
     For their interaction with each other, the guard is positioned inside the lumen of the holder with its outer surface facing the inner surface of the holder. Also, a spring is positioned between the guard and the adapter to urge the guard in a distal direction along the axis. Importantly, the guard is formed with a cantilevered tab that can be outwardly deflected from the surface of the guard, into a stressed configuration. With the cantilevered tab in this stressed configuration, the spring urges the tab against the distal abutment on the holder to prevent further movement of the guard in a distal direction. This puts the guard in a ready-to-activate condition. On the other hand, when the tab is lifted from the distal abutment it will move from its stressed configuration, into an unstressed configuration. In this unstressed configuration, the cantilevered tab is flush with the outer surface of the guard and is clear of any interaction with the holder. 
     In the operation of the system of the present invention, the guard is sequentially moved through three, distinctly identifiable positions. These are an initial position, a retracted position, and a final (locked) position. In its initial position (i.e. the ready-to-activate condition discussed above) the cantilevered tab on the guard is in its stressed configuration. Also, the tab is being urged against the distal abutment to hold the guard stationary, relative to the holder. In this initial position, a distal portion of the needle extends from the guard. A cover can be engaged with the holder to protect the exposed distal end of the needle. 
     For use of the system in a blood collection procedure, the cover is removed from the holder. The needle is then inserted to establish fluid communication with a patient (fluid source). With this insertion, the guard is moved over the needle in the proximal direction to the retracted position. This causes further exposure of the needle and causes the cantilevered tab to be lifted from the distal abutment. The cantilevered tab then transitions into its unstressed configuration. 
     Upon completion of the blood collection procedure, the needle is withdrawn and the guard moves in the distal direction to its final position. In this final position, the guard covers the distal portion of the needle, and an extension limiter that is formed on the guard is engaged with the proximal abutment to prevent an uncovering of the distal portion of the needle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The novel features of this invention, as well as the invention itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which: 
         FIG. 1  is a perspective view of the safety system for a fluid collection device in accordance with the present invention; 
         FIG. 2  is an exploded view of the system showing the interrelationship of its constituent components; 
         FIG. 3  is a perspective view of the holder; 
         FIG. 4  is a cross-sectional view of the holder as seen along the line  4 - 4  in  FIG. 3 ; 
         FIG. 5  is a perspective view of the guard; 
         FIG. 6  is an end view of the guard as seen along the line  6 - 6  in  FIG. 5 ; 
         FIG. 7  is a perspective view of the adapter; 
         FIG. 8A  is a cross-sectional view of the system as seen along the line  8 - 8  in  FIG. 1  with the guard in its initial position; 
         FIG. 8B  is a cross-sectional view of the system as seen along the line  8 - 8  in  FIG. 1  with the guard in its retracted position; and 
         FIG. 8C  is a cross-sectional view of the system as seen along the line  8 - 8  in  FIG. 1  with the guard in its final, locked position. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring initially to  FIG. 1 , a safety system for a blood collection device is shown and generally designated  10 . As shown, the system  10  includes a holder  12  and a cover  14  that is engageable with the holder  12 . In addition to the holder  12  and cover  14 , all of the various components of the system  10 , and their interrelationship with each other are, perhaps, best seen with reference to  FIG. 2 . 
     In  FIG. 2 , the system  10  is shown to include a guard  16 , a spring  18 , a needle  20 , and an adapter  22 , as well as a sheath  24 . These components are shown aligned along an axis  26 , with the cover  14  being shown in a distal position, and the sheath  24  being shown in a proximal position. 
     Details of the holder  12  will be best appreciated with reference to both  FIG. 3  and  FIG. 4 .  FIG. 3  shows that the holder  12  is externally formed with finger grips  28  (the grips  28   a  and  28   b  are exemplary), and a base flange  30 . In more detail  FIG. 4  shows that the holder  12  is substantially tubular in shape and that, internally, it has an inner surface  32  that surrounds a lumen  34 . Further, it is seen that the inner surface  32  is formed with a distal abutment  36 , and at least one proximal abutment  38 . Still further, it is seen that the inner surface  32  of holder  12  is formed with ribs  40  (the ribs  40   a  and  40   b  are exemplary) that extend longitudinally in the lumen  34  of holder  12 , substantially parallel to the axis  26 . Also, all of the ribs  40  (e.g. ribs  40   a  and  40   b ) are shown formed with a respective detent  42  (e.g. detents  42   a  and  42   b ). 
     The guard  16  is best understood with reference to both  FIG. 5  and  FIG. 6 . Specifically,  FIG. 5  shows that the guard  16  is formed with a cantilevered tab  44  and a pair of extension limiters  46   a  and  46   b  (also see  FIG. 6 ). More specifically, the cantilevered tab  44  is shown flush with the outer surface  48  of the guard  16  in  FIG. 5 . In this configuration (i.e. when the tab  44  is flush with the outer surface  48 ) the cantilevered tab  44  is unstressed. It is to be appreciated, however, that when the cantilevered tab  44  is deflected outwardly from the outer surface  48  of the guard  16 , it is placed in a stressed configuration. In this stressed configuration, the cantilevered tab  44  will be biased to return to its unstressed configuration.  FIG. 5  also shows the cantilevered tab  44  is formed with a channel  50 . Specifically, the channel  50  is provided so that a tool (not shown) can be inserted into the channel  50  from the proximal end of the guard  16  to deflect the cantilevered tab  44  into its stressed configuration during assembly of the system  10 . Additionally,  FIG. 6  shows that the guard  16  is formed with a pair of ridges  52   a  and  52   b  that form a groove  54 . 
       FIG. 7  shows that the adapter  22  includes an extension  56  that is formed with a shoulder  58 . This extension  56  of adapter  22  is formed with a lumen  60  and, additionally, the adapter  22  includes a disk  62  that is oriented substantially perpendicular to the extension  56 . Further, the adapter  22  has a pair of parallel prongs  64   a  and  64   b  that are substantially perpendicular to the extension  56 . 
     In the assembly of the system  10 , the needle  20  is positioned through the lumen  60  of adapter  22  and is held on the adapter  22  by means well known in the pertinent art, such as by solvent bonding. The spring  18  is then placed over the distal end (portion)  68  of the needle  20 , and also over the extension  56  of the adapter  22 . This positions the proximal end  66  of spring  18  against the shoulder  58 . The distal end (portion)  68  of needle  20 , and the distal end  70  of spring  18  are then inserted into the guard  16 . With this insertion, the distal end  70  of spring  18  is positioned against the distal end  72  of the guard  16 , and the distal end (portion)  68  of needle  20  can extend through the opening  74  at the distal end  72  of guard  16 . This combination is then engaged with the holder  12 . 
     For engagement of the guard  16  with the holder  12 , a tool (not shown) is forced into the channel  50  of cantilevered tab  44  to deflect the cantilevered tab  44  into its stressed configuration. The guard  16  is then inserted into the lumen  34  of holder  12 . During this insertion, the guard  16  is positioned so that one of the ribs  40  (e.g. rib  40   b ) is received in the groove  54  created by the ridges  52   a  and  52   b . This interaction then prevents a rotation of the guard  16  relative to the holder  12 . Also, during this insertion, the prongs  64   a  and  64   b  on adapter  22  are positioned to also straddle one of the ribs  40 . With these components oriented in this manner, insertion continues until the disk  62  of adapter  22  snaps into engagement with the detents  42  of ribs  40 . 
     With the snap engagement of adapter  22  with the detents  42  on ribs  40 , the cantilevered tab  44  (now in its stressed configuration) is forced by the compressed spring  18  into contact with the distal abutment  36 . Specifically, as long as there is no proximally directed force on the guard  16 , the distally directed force of spring  18  will hold the cantilevered tab  44  against the distal abutment  36 , in its stressed configuration. The cover  14  is then engaged with the holder  12  to protect the otherwise exposed distal end (portion)  68  of the needle  20 . This places the guard  16  in an initial position where it is in a ready-to-activate condition (see  FIG. 8A ). 
     In the operation of the system  10  of the present invention, the cover  14  is first removed. As seen in  FIG. 8A , this will expose the distal end (portion)  68  of needle  20  so it can be inserted into a patient (not shown) and used for a blood collection procedure. As the needle  20  is being inserted into the patient, a force is generated against the compression force in spring  18 . This causes the guard  16  to move in the proximal direction along axis  26  to a retracted position (shown in  FIG. 8B ). As the guard  16  moves to this retracted position, the cantilevered tab  44  is lifted from the distal abutment  36 . This then allows the cantilevered tab  44  to return to its unstressed configuration. Importantly, in its unstressed configuration, the cantilevered tab  44  is now flush with the outer surface  48  of guard  16  and clear of any subsequent interaction with the holder  12 . 
     While the guard  16  is in its retracted position ( FIG. 8B ), a fluid collection vial (not shown) can be connected in fluid communication with the proximal end  76  of needle  20 . As will be appreciated by the skilled artisan, sequential fluid collection vials can be so connected. Then, after the fluid collection procedure is completed, the needle  20  can be withdrawn from the patient. With this withdrawal, the compression force in spring  18  causes the guard  16  to move in a distal direction along the axis  26  to move the guard  16  into its final (locked) position ( FIG. 8C ). In this final position, the ridges  52   a  and  52   b  on guard  16  are in contact with the holder  12  to prevent any additional movement of the guard  16  in a distal direction on the holder  12 . Also, in this final position, the extension limiters  46   a  and  46   b  on the guard  16  are engaged, respectively, with a proximal abutment  38  to prevent any additional movement of the guard  16  in a proximal direction on the holder  12 . Thus, the guard  16  is locked to cover the distal end (portion)  68  of needle  20  to protect the user from an inadvertent “stick” by the needle  20 . The system  10  can then be discarded. 
     While the particular safety system for a blood collection device as herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages herein before stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as described in the appended claims.