Abstract:
The invention relates to a safety blood collecting device adapted to prevent accidental puncturing of attending medical personnel by an infected blood collecting needle. The blood collecting device has a forward conical portion which is provided with a vein aligning groove to allow convenient positioning of the needle guard in relation to the vein of the patient for precise injection of the needle. One or more resilient depressible locking tabs are carried by the needle guard and extend through corresponding aligned openings formed in the casing to lock the needle guard in an extended position covering the needle. When the locking tabs are depressed and an inward pressure is exerted on the forward end of the needle guard, the needle guard can be moved against the tension of a coil spring inside the casing and uncover the blood collecting needle to allow withdrawing of the blood from the patient.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to medical equipment, and more particularly to a safety blood Collecting device designed to prevent accidental needle stick injuries by medical personnel, for example during drawing of a blood specimen of a patient. 
     The ever increasing spread of diseases transmitted by blood and other bodily fluids, such as Acquired Immune Deficiency Syndrome and Hepatitis B creates a real threat to medical personnel of accidental, inadvertent puncturing of the skin by a blood collecting needle which has been in contact with an infected patient and of the transmittal of the often fatal disease to the unfortunate medical attendant. Despite educational programs carried by many hospitals, accidents continue to happen with an unfortunate effect of medical personnel being infected through coming in contact with bodily fluids of a patient. 
     Various attempts have been made to resolve this problem by proposing to use a protective needle guard, which would cover the needle when the blood collecting device is not in use and prevent the needle from being exposed during those times. However, such devices are expensive to manufacture and difficult to use, requiring several steps in preparation of the blood collecting device for utilization and, so far, have not found wide acceptance in the medical profession. 
     The present invention contemplates elimination of drawbacks associated with prior art and provision of an improved safety blood collecting device particularly adapted for drawing blood from a patient and which is easy to use and inexpensive to manufacture. 
     SUMMARY OF THE INVENTION 
     It is, therefore, a general object of the present invention to provide a self-locking safety blood collecting device which is designed to prevent premature exposure of the needle. 
     It is another object of the present invention to provide a locking device for covering the needle at all times before insertion of the needle into the vein. 
     It is a further object of the present invention to provide a needle guard which is particularly adapted for aligning the needle about the vein of a patient. 
     These and other objects are achieved through a provision of a safety blood collecting device which comprises a tubular needle holder carrying a needle assembly on one end thereof and which is surrounded by a tension spring which abuts an enlarged flange on the free end of the holder. A needle guard is mounted in a partially surrounding relationship over the needle holder and covers the needle assembly in its entirety when the blood collecting device is not in use. The needle guard has a forward most conical portion which is provided with a narrow opening in its apex. 
     The needle, when in use, is allowed to pass through the opening and enter the body of the patient. The conical portion is further provided with a vein alignment groove formed in the conical wall and extending through substantially entire length thereof. When in use, the groove is aligned over the vein of the patient, thus ensuring proper alignment of the needle during drawing of the blood. 
     A cylindrical middle portion of the needle guard carries a pair of resiliently depressible locking tabs which snap out of corresponding openings formed in the casing when the blood collecting device is not use. The casing surrounds the middle portion of the needle guard and the needle holder to which the casing is fixedly attached. The inner grooves formed in the casing allow sliding of the depressed locking tabs therein. A tension spring continuously urges the needle guard in covering relationship over the needle assembly, but the force of the tension spring is overcome once a pushing pressure is applied to the tip of the needle guard. To prevent puncturing of the skin of the patient by the needle guard, the tip of the conical portion is made with rounded walls. 
     A pair of alignment runners are formed on the middle portion of the needle guard, said runners being slidably received within grooves formed in the inner wall of the casing at a 90 degree angle in relation to the locking tab grooves. 
     A blood collecting reservoir is removably positioned within a -needle holder in co-alignment with the needle assembly, so as to allow collection of the blood sample from a patient and detachment of the reservoir once the necessary amount has been collected. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Reference will now be made to the drawings, wherein like parts are designated by like numerals and wherein: 
     FIG. 1 is an exploded view of the device in accordance with the present invention. 
     FIG. 2 is a view of the device in an assembled state. 
     FIG. 3 is an exploded view of the device in accordance with the present invention looking at a 90 degree angle from the view of FIG. 1. 
     FIG. 4 is an assembled view of the device taken at a 90 degree angle from FIG. 2. 
     FIG. 5 is an end view of the needle holder. 
     FIG. 6 is an end view of the needle guard; and 
     FIG. 7 is an end view of the casing. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings in more detail, numeral 10 designates the device in accordance with the present invention. The safety blood collecting device comprises a needle holder 12, a needle assembly 14, a compression tension spring 16, a needle guard 18 and a casing 20. The needle holder 12 is a hollow, generally cylindrical body having a reduced diameter nose portion 22 provided with a central opening 24 therein, and internal threads schematically shown and designated by numeral 26. The holder 12 is provided with an enlarged diameter end plate 28 which encircles the central opening 30 made in the holder 12. As can be seen in FIG. 5, the opening 24 is considerably smaller in diameter than the opening 30 which defines the interior chamber formed in the holder 12. 
     Detachably mounted within the holder 12 is a blood collecting reservoir 32 which is similar to conventional blood collecting tubes in that a vacuum is created in the chamber 34, and the reservoir is sealed by a plug 36 covering the open end 33 of the reservoir. The opposite end 35 is made closed, as can be seen in FIG. 1. The plug 36 is made from a soft resilient material having plastic memory. 
     The needle assembly 14 has an elongated sharp-ended needle 40 and a securing portion 42 which comprises an externally threaded part 44 extending inwardly from a plate 46. When assembled with the holder 12, the plate 46 contacts the nose portion 22, while the threaded part 44 fits within the opening 24 and engages with the threads 26. The opposite, inner part 41 of the needle 40 is enclosed in a sheath 43 which can be made of rubber thin enough to be punctured by the needle part 41 without application of any substantial force. The sheath 43 passes through the opening 24 into the holder 12. When the reservoir 32 is engaged with the holder 12, immediately before collecting blood from a patient, the needle part 41 punctures the sheath 43, then plug 36 and forces its way into the tube 32 opening fluid communication between the sharp end of the needle 40 and the interior chamber 34 of the tube 32. 
     The needle guard 18 comprises a conical forward portion 50 which is provided with a narrow rounded wall apex 52 having a small diameter opening 54 in the center thereof. Formed in the conical wall is a vein stabilizing groove 56 which extends from the tip, or apex 52 inwardly towards the middle portion 58 of the needle guard 18. The groove 56 is an elongated narrow groove having a width approximating the width of a human vein. The function of the groove 56 will be explained in more detail hereinafter. Attached to the opposite end of the middle portion 58 is an inner part 60 which is greater in diameter than the portion 58 and which is provided with inwardly inclined shoulder 62 formed at the line of connection between the portions 58 and 60. 
     A pair of depressible locking tabs 64 and 66 are attached to diametrically opposite sides of the portion 60 and are carried by their supporting members 68 and 70, respectively. The supporting members 68 and 70 are flexible and yield when compression is applied to the locking tabs 64 and 66, allowing the tabs to move inwardly in relation to the casing 20, as will be described below, and push the tabs 64 and 66 outwardly through the specially designed openings in the casing, when the tabs are released. 
     Formed a distance from the tabs 64 and 66 is an annular shoulder 72 which forms a first abutting shoulder for the end 74 of the compression spring 16. 
     Also formed on diametrically opposite sides of the portion 60 is a pair of elongated runners 76 and 78 which extend along the length of the portion 60 and are adapted for engagement with corresponding runner grooves 80 formed in the body of the casing 20. The runners 76 and 78 are narrow strips which are fixedly attached to the exterior surface of the portion 60 at 90 degrees from the locking tabs 64 and 66. The runners 76 and 78 facilitate alignment of the needle guard 18 in its sliding movement within the casing 20. 
     A circular cutout groove 82 formed in the proximate end of the needle guard 18 has a diameter slightly greater than the diameter of the compression spring 16, so that a portion of the spring 16 fits within the cutout 82, as can be better seen in FIGS. 2 and 4. The opposite end 84 of the spring 16 abuts against the inner surface 86 of the needle holder 12, when the blood collecting device is assembled. 
     The casing 20 comprises an elongated cylindrical hollow body with a first open end 90 and a second open end 92. Formed in diametrically opposite locations in the walls of the casing 20 are a pair of openings 94 and 96 which are sized to allow the locking tabs 64 and 66, respectively, to extend outwardly therethrough. The openings 94 and 96 communicate with the respective locking tab grooves 98 and 100 which allow movement of the locking tabs 64 and 66 therein when the needle guard 18 moves telescopically inside the casing 20. 
     An annular, inwardly inclined shoulder 102 is formed at a distal end of the casing 20, the shoulder 102 being inclined at an angle which matches the angle of the shoulder 62 formed on the needle guard 18, so that when the shoulders 62 and 102 come into contact, their angles match. The end 90 of the casing 20 has a rounded wall 104, while the end 92 is formed with an annular recess 106. An enlarged diameter flange 108 surrounds the recess 106 in a circumferential relationship. The end plate 28 of the needle holder 12 fits within the recessed groove 106 and is fixedly attached to casing 20 within said recessed grove 106, as can be better seen in FIGS. 2 and 4, closing the open end 92. 
     When assembled, the holder 12 is engaged with the needle assembly 14 and is positioned within the needle guard 18 in such a manner that the needle 40 extends in the hollow interior of the needle guard 18. Since the overall length of the needle guard 18 is greater than the length of the needle 40, no portion of the needle extends outwardly from the opening 54 in the Lip 52 when the blood collecting device is not in use. The spring 16 is compressed between the flange 28 and the shoulder 72 and extends in a surrounding relationship about the needle holder 12. The casing 20 is slid over the needle guard 18 until the locking tabs 64 and 66 are forced through the openings 94 and 96, respectively. 
     Once assembled, the needle guard 18 is prevented from telescopical movement in relation to the casing 20 by the outwardly extending locking tabs 64 and 66. However, when the locking tabs 64 and 66 are compressed, they move into the grooves 98 and 100 and the guard 18 can telescopically move into the casing 20 when a push force is applied to the tip 52. The guard 20 moves against the expanding force of the spring 16, allowing the tip of the needle 40 to be injected for performing an injection. 
     Prior to injection, the user can conveniently align the conical portion 50 above the vein of the patient in such a manner that the groove 56 is substantially oriented in the direction of the vein and surrounds it on the skin of the patient, assisting the user to keep the needle 40 in alignment with the vein. When the needle guard 18 is moved as described above, the tip of the needle 40 can be inserted into the vein of the patient and the blood can be drawn by forcing the vacuum tube 32 over the opposite end of the double sided blood collecting needle 40 inside the needle holder 12. As the vacuum tube is advanced within the needle holder, the second end of the blood collecting needle punctures the vacuum tube plug and the vacuum inside the vacuum tube aspirates the blood from the patient. Since the plug 36 is made of soft material the punctured area will automatically seal around the needle 41. The sheath at this time is folded and pushed forward by the plug 36. Once the operation is complete, the user withdraws the device and the expansion force of the spring 16 will force the cone 50 outwardly from the casing 20, again concealing the needle 40 and forcing the locking tabs 64 and 66 to extend through the openings 94 and 96, respectively. The user then disengages the tube 32 from the holder 12. The plastic memory of the plug 36 will seal the punctured opening retaining the blood in the tube 32. 
     The device 10 of the present invention can be manufactured from any convenient material, such as plastic, with the exception of the needle 40 which should be preferably made of metal. It is envisioned that various sized blood collecting devices can be manufactured utilizing the basic concept of the instant invention giving the user a choice of various volume holders 12, as well as different size needles 40. 
     Many changes and modifications can be made within the design of the present invention without departing from the spirit thereof. I, therefore, pray that my rights to the present invention be limited only by the scope of the appended claims.