SAFETY DEVICE FOR A NEEDLE HAVING TWO SHARPENED ENDS

Abstract: A safety device (130) for a phlebotomy needle (40) having two sharpened tips (100, 100'), a forward or distal tip (100) which is used for percutaneous sampling and a rear or proximal tip (100') which is used to penetrate vacuum sampling tube stoppers. The phlebotomy needle safety device (130) has a needle shield (158) disposed about the rear or proximal needle (100'), which is displaced only by the standard action of threadably connecting the device (130) to a phlebotomy barrel (168) to permit penetration of vacuum sampling tube stoppers. The device (130) also has a retractable and extendable, protective medical needle shield (162) which provides opportunity for accessing and reaccessing a forward or distal needle (40) and associated sharpened needle tip (100) and recovering the needle (40) and tip (100) for safety between accesses. The shield (130) includes a needle guide (192, 194) which assures that the forward needle tip is untouched by any part of the shield (130) as the shield (130) is displaced to cover and uncover the needle (40).

Description: SAFETY DEVICE FOR A NEEDLE HAVING TWO SHARPENED ENDS FIELD OF THE INVENTION This invention relates generally to safety devices for hollow bore medical needles and particularly to phlebotomy and other like medical safety devices employing needles having two sharpened ends. BACKGROUND OF THE INVENTION Problems associated with inadvertent needle sticks are well known in the art of blood sampling, percutaneous medication injection and other medical procedures involving use of medical needles. Ever increasing attention is being paid to needle stick problems due to the contemporary sensitivity of exposure to AIDS, Hepatitis and other serious blood-borne diseases. Procedures involving removing a needle from a patient commonly require a technician to use one hand to place pressure at the wound site where the needle is being withdrawn, while removing the needle apparatus with the other hand. It is common practice for an attending technician to give higher priority to care for the wound than is given to disposal of a needle. In the case of common non-safety devices, such priority either requires the convenience of an available sharps container within ready reach or another means for safe disposal without leaving the patient's side. Providing adequate care, with accompanying safety procedures, is often compounded by the patient ' s physical condition and mental state (e.g., in burn units and psychiatric wards). Under such conditions, it is often difficult, if not impossible, to take the appropriate action to properly dispose of a used, exposed needle while caring for a patient. The common practice of filling syringes with medication in one area and then transporting an uncapped needle to a patient area provides a significant opportunity for accidental needle sticks. Recapping a needle is currently discouraged in U.S. medical practice due to the dangers of accidental needle sticks associated with recapping. The widespread knowledge and history associated with needle care and disposal problems have resulted in the numerous devices for preventing accidental needle sticks. Current devices for shielding syringe needles often require two hands, and with some devices the safety status of needle shields are not readily apparent. Most devices in the safety needle field relating to phlebotomy are concerned with providing protection against accidental needle sticks resulting from the interaction with the forward or distal sharpened needle tip of the device. Phlebotomy devices have two sharpened needle tips. The forward or sharpened needle tip is for percutaneous entry, and a rear or proximal needle tip is for penetrating a vacuum tube stopper. The rear or proximal needle tip is normally disposed within a phlebotomy barrel during use. However, it is often considered to be more dangerous since it is commonly hidden by a blood valve for impeding blood flow when sampling tubes are removed from contact with the rear needle tip. The rear needle is protected by the barrel while the needle is in use and if the barrel is thrown away with the needle. But the rear needle is commonly removed from the barrel for disposal. A number of devices (usually associated with sharps containers) have been placed on the market for the purpose of providing safe containment and eventual disposal of used phlebotomy needles. Some of the devices have special inserts which facilitate the separation of the needle from the barrel and subsequent delivery of the used separated needle into a sharps disposal container. However, such procedures and devices, generally add operational steps, increase utilization cost and often result in a period of time during the disposal procedure when one or both needle tips are not protected. SUMMARY OF THE INVENTION In brief summary, the novel invention disclosed herein diminishes known problems resulting from injury-related needle sticks which may occur at the end of a medical procedure. This invention provides for fabrication of a very low cost safety needle system which allows for the disposal of a medical needle without undo hazard before placing the needle into an appropriate waste container. In the present invention, a shield is disposed about a needle and tip to provide protection of the forward sharpened end. Any safety forward needle shield may be used within the scope of this invention. However, a device having a releasible latch is disclosed which may be disengaged to refold the shield and permit reaccess to the needle J in a subsequent medical procedure. Once each procedure is complete, the shield is again extended and latched to provide a safety cover. Furthermore, a lock should be provided for selectively and permanently affixing the protective shield to assure protection of a secured needle tip protection after use. In one embodiment, the shield includes a needle guide proximally disposed relative to the tip of a forward needle, which protects the forward needle tip. This protection occurs as the protective shield is displaced to cover and shield the needle and as the shield is removed to bare the needle for use. The needle guide is disposed and constrained to travel in alignment with the long axis of the needle, but constrained to facilitate movement of the shroud about the needle without contacting the needle tip. A releasible needle shield provides for a phlebotomy needle assembly which may be uniquely packaged for transport and later used with a reusable phlebotomy barrel. Phlebotomy needle assemblies generally include a pair of sharpened needle points. An aspect of this invention is a protective shield which is passively released to bare the rear needle only when the phlebotomy needle assembly is inserted into the phlebotomy barrel . A combination of a releasible needle shield for the forward needle tip and a passive shield for the rear needle tip permits the needle to be packaged in a "soft package" for transport prior to use. This reduces the cost and complexity of protective packaging components. Other important factors in safety needle devices involve whether the device can be effectively used by a single hand and whether there are extra steps involved in activating a safety mechanism. According to the present invention, the act of threadably inserting each needle, into a barrel bares the rear needle tip for use. The act of unthreading the needle from the barrel protectively recovers the rear needle tip. Thus, the rear needle is passively protected. Protection of the forward needle tip is preferably accomplished by a single, one-handed step. An object of the present invention is to provide a safety phlebotomy needle device which has protective shields for both sharpened needle tips for protection before the needle is affixed to a phlebotomy barrel and after the needle is removed from the barrel. A further object of the present invention is to provide a phlebotomy needle device which can safely be packaged in a "soft package." Another object of the present invention is to provide a needle guide which is disposed to operate within the shield to assure the sharp tip of the needle is untouched throughout each needle covering and baring procedure. Yet another object of the present invention is to provide a safety shield, for the proximal end of a phlebotomy needle, which is passively removed when the needle is inserted into a phlebotomy barrel. Briefly summarized, the foregoing objects are achieved by a safety device for a phlebotomy needle comprising: a phlebotomy barrel which is threadably affixed to an otherwise separate phlebotomy needle hub assembly for the purpose of capturing physiologic samples in a blood sampling tube, the phlebotomy needle hub assembly comprising a phlebotomy needle firmly affixed in a needle hub and having a forward. distally disposed sharpened tip and a rear, proximally disposed sharpened tip, and a shield for the rear, proximally disposed sharpened tip, the shield being disposed to cover and protect the proximally disposed sharpened tip while the phlebotomy needle hub assembly is unattached to said phlebotomy barrel and being displaced to provide access by the blood sampling tube only when the phlebotomy needle hub assembly is affixed to phlebotomy barrel. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a cross-section of a lateral view of a related art phlebotomy device including a phlebotomy needle with proximal and distal sharpened ends, a needle hub, a blood valve and a phlebotomy barrel. Figure 2 is a perspective view of a medical shield assembly for phlebotomy which provides protection for the proximal and distal tips of a phlebotomy needle. Figure 3 is a lateral cross-section view of the medical shield assembly of Figure 2 disposed in a phlebotomy barrel with a blood valve removed for clarity of presentation. Figure 4 is a perspective view of the device shown in Figure 3. Figure 5 is a perspective view of the device shown in Figure 4 having the shield assembly displaced to partially expose a needle disposed therein. Figure 6 is a perspective view of the device shown in Figures 2 and 3 wherein the shield assembly is displaced to provide maximum exposure of the needle. Figure 7 is a perspective view of a distal shield and hub section of the device shown in Figures 2-6. Figure 8 is a perspective view of a proximal needle shield of the device shown in Figures 2-6. DETAILED DESCRIPTION OF THE INVENTION In this description, the term proximal is generally used to indicate relative nearness of a referenced item to a user of a device or a viewer. The term distal is similarly used to indicate relative remoteness. In those cases where parts have similar, but not identical, form and function, numerals with primes may be used for ease in interpretative cross referencing. Reference is now made to the embodiments illustrated in Figures 1-8 wherein like numerals are used to designate like parts throughout. A phlebotomy device 30, which is representative of devices currently being used, is illustrated in Figure 1. Device 30 generally utilizes a needle 40 having two sharpened ends 100 and 100'. In this case, a hub 42 has a threaded connection 44 which may be used with a phlebotomy barrel, such as the phlebotomy barrel 50 seen in Figure 1 and described in detail hereafter. Reference is now made to Figures 2 wherein another embodiment of a needle shield device 130 is seen. A cross-sectional representation of a phlebotomy device 30 is provided in Figure 1 to better disclose the inventive aspects of device 130. Phlebotomy device 30 is commonly assembled from two parts, a phlebotomy barrel 50 and a phlebotomy needle assembly 42. Phlebotomy barrel 50 generally consists of an elongated cylindrical barrel 138 and a needle assembly introduction port 140 distally disposed in an otherwise closed end 142. Port 140 has a female threaded connection 144 by which assembly 42 is securely affixed to barrel 50 for use. Assembly 42 has a needle hub 146 comprising a male threaded connector 44 adaptable to female threaded connection 144. Hub 146 has an elongated bore hole 150 into which a medical needle 40 with its two sharpened ends 100 and 100' is inserted and securely affixed. End 100' commonly has a non-coring bevel for use in penetrating stoppers of a blood collection vacuum tube. To minimize uncontrolled blood flow when a blood collection vacuum tube is not attached to end 100', a blood valve 152 is usually affixed to hub 146 about a proximal portion of needle 40 and end 100'. A barrel, such as barrel 50, is typically provided separate from assembly 42, with both ends 100 and 100' of needle 40 protectively covered for transport and storage. Before interconnecting assembly 42 to barrel 50, a cover is removed from the end 100' and hub 146 is threadably affixed to barrel 50. During this procedure, needle tip 100' is unprotected. A cover is then removed from needle end 100 of needle 40 to prepare device 30 for use. After assembly 42 is used, it is removed from barrel 50 and usually disposed of in a sharps container. For safety reasons, it is becoming more common to shroud a used phlebotomy needle with a safety needle shield at the end of a medical procedure. However, proximal sharp needle points, such as needle end 100', are rarely protected. Such a lack of protection is often compensated for by special methods of disengaging a used needle assembly from a barrel while disposing the used needle assembly into a sharps container. Referring again to Figure 2, device 130 provides for protectively covering both sharp ends 100 and 100' of a double ended phlebotomy needle 40 (see Figure 3). As seen in Figure 3 , device 130 is assembled from two parts, a rear needle protection component 154 and a forward needle-hub-shield assembly 156. Component 154 has a rear needle shield 158 and an associated distally disposed fitting 160, the purpose and function of each of which shall be disclosed in full hereafter. Assembly 156 comprises a needle shield 162, and a needle hub 164 to which a needle 40 is securely affixed. Hub 164 and needle 40 are seen in combination in Figure 3. Similar to hub 146, hub 164 has a proximally disposed threaded section 166 for releasibly, but securely affixing device 130 to a phlebotomy barrel. Such a phlebotomy barrel 168 is seen in Figure 3. A perspective view of component 154 is seen in Figure 8. Component 154 has a distal threaded feature 170 having a sloped proximally disposed arcuate face 172. which has substantially the same pitch as threaded section 166 of hub 164 shown in Figure 3. As shown in Figure 3, hub 164 has a hollow cylindrical cavity 165 in which a knob 174 is medially disposed. Knob 174 is sized to fit within threaded feature 170 when component 154 is inserted into cavity 165 and to thereby constrain the inserted component 154 to threadably screw component 154 into cavity 165 as device 130 is threadably connected to barrel 168. For initial assembly, feature 170 has a distally disposed slot 176 which is sufficiently large to permit knob 174 to be forcefully urged into engagement with threaded feature 170. However, feature 170 is sufficiently small to resist facile extraction of knob 174 from feature 170. Feature 170 also comprises a blind end 178 which restricts knob 174 from being disengaged from feature 170 by unthreading. A hex shaped connector 180 is proximally disposed relative to feature 170. Connector 180 may be any shape which may be linearly inserted into a complimentary receiving female connector, such as connector 182 (see Figure 3). In this manner, component 154 is restricted from rotation as device 130 is threadably joined with a phlebotomy barrel, such as barrel 168, until hub 164 is fully seated into section 166. As device 130 is threadably joined to phlebotomy barrel 168, feature 170 is likewise screwed into cavity 165, which effectively shortens the length of device 130. This device shortening urges rear needle shield 158 distally relative to proximal needle tip 100' and exposes tip 100' for use in piercing a stopper of a vacuum sampling tube. Note that in an unattached device 130, such as device 130 in Figure 2, rear needle shield 158 protectively covers needle tip 100'. When device 130 is affixed to a barrel, such as barrel 168 in Figure 3 , rear needle shield 158 is displaced distally relative to tip 100', thereby exposing tip 100' for us in piercing vacuum sampling tube stoppers. When device 130 is threadably removed from barrel 168, device 130 is again lengthened, thereby covering needle tip 100' with rear needle shield 158 by restricting component 154 from rotating while device 130 is threadably detached. With a safety shield protectively disposed about needle tip 100 and with device 130 removed from barrel 168, both ends of needle 40 are protected as seen in Figure 2. Component 154 may be made as a single injection molded part from a synthetic resinous material such as polypropylene or equivalents thereof. In similar fashion. needle-hub-shield assembly 156 may also be made as a single injection molded part from polypropylene or equivalents thereof. Generally, medical needles, such as needle 40, are generally made from medical grade stainless steel. To assemble device 130, needle 40 is securely affixed to hub 164 of needle-hub- shield assembly 156 as seen in Figure 7. Then slot 176 (see Figure 8) is disposed to receive knob 174. Component 154 is forcefully inserted to cause knob 174 to be displaced through slot 176 such that knob 174 resides in alignment with proximally disposed face 172. Once knob 174 is so disposed, device 154 may be rotated relative to assembly 156 to displace knob 174 across a raised stop 184 into contact with blind end 178 to provide a secure, but releasible transport state for device 130. Stop 184 is a bump raised to resist rotation of component 154 relative to assembly 156, but which is overcome by forces consistent with threading device 130 into barrel 168. Referring again to Figure 3, in addition to hub 164, assembly 156 is seen to comprises needle shield 162 having a proximal shield segment 186 and a distal shield segment 188. One skilled in the art understands that needle shields having different numbers of segments and other attributes such as needle/shield latches may be used within the scope of the invention. Proximal segment 186 comprises an actuator button 190. Distal segment 188 has an appurtenance 192 which acts as a skid to prevent binding of shield 162 when actuator button 190 is depressed. No latch is shown in Figure 3 ; however, latches, both releasible and unrelesible may be used in the shields for device 130. Each needle shield, such as shield 162, must be disposed in a substantially rigid state when covering a needle to effectively provide a protective cover. For this reason, when releasible latches are used, a positive action should be required to unlatch a shield to expose a needle for use. When so disposed, the shield, such as shield 162, protects needle tip 100 by constraining needle 40 along its long axis and by distally enclosing tip 100 by a closed face 194. Reference is now made to Figure 6 wherein an assembled combination of barrel 168 and device 130 are ready for use. In this state, needle tip 100' is also bared for use as seen in Figure 3. Depressing actuator button 190 in the direction of arrow 196, as seen in Figure 5, extends shield 162. Shield 162 is seen to be fully extended in Figure 4. Once shield 162 is fully extended, device 130, with safety shields employed over needle tips 100 and 100' may be removed from barrel 168 in a needle safety state. The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is 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 by 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. What is claimed and desired to be secured by Letters Patent is:

Claims: CLAIMS 1. A safety device for a phlebotomy needle comprising: a phlebotomy barrel which is threadably affixed to an otherwise separate phlebotomy needle hub assembly for the purpose of capturing physiologic samples in a blood sampling tube: the phlebotomy needle hub assembly comprising a phlebotomy needle firmly affixed in a needle hub and having a forward, distally disposed sharpened tip and a rear, proximally disposed sharpened tip; and a shield for the rear, proximally disposed sharpened tip. said shield being disposed to cover and protect the proximally disposed sharpened tip while the phlebotomy needle hub assembly is unattached to said phlebotomy barrel and being displaced to provide access by the blood sampling tube only when the phlebotomy needle hub assembly is affixed to phlebotomy barrel. 2 The safety device for a phlebotomy needle according to Claim 1, further comprising a safety shield for the forward, distally disposed needle tip. 3. The safety device for a phlebotomy needle according to Claim 1 , wherein said phlebotomy barrel comprises a first female connector which threadably receives a complementary first male threaded connector of the phlebotomy needle hub assembly, said first female threaded connector further comprising a proximally disposed locking member which slidably engages and thereby resists rotation of a portion of the phlebotomy needle hub assembly as said phlebotomy needle hub assembly is being threadably affixed to said phlebotomy barrel 4. The safety device for a phlebotomy needle according to Claim 3 , wherein the needle hub in which said phlebotomy needle is firmly affixed comprises a first male threaded connector part having a diameter and pitch which is compatible with being threadably affixed to said first female barrel connector. 5. The safety device for a phlebotomy needle according to Claim 4. wherein the needle hub in which said phlebotomy needle is firmly affixed comprises a second female threaded connector part disposed within said first male connector part, said second female threaded connector part having a diameter which is smaller than the first male connector part and a pitch which is substantially the same as the first male threaded connector part. 6. The safety device for a phlebotomy needle according to Claim 5. wherein the needle hub in which said phlebotomy needle is firmly affixed within said male connector part comprises a rear needle shield comprising a second male threaded connector part having a diameter and pitch which corresponds to the hub assembly second female threaded connector part and a rear shield having a length which protectively extends about and beyond the proximal sharpened tip when the phlebotomy needle hub assembly is disconnected from said phlebotomy barrel. 7. The safety device for a phlebotomy needle according to Claim 6, wherein said rear needle shield further comprises a fitting which is slidably displaced into said locking member when connection is made between the first male and female threaded connectors thereby causing said rear needle shield to resist rotation relative to the phlebotomy barrel as the rear needle assembly is threadably engaged with said phlebotomy barrel, resulting in said second male connector part being threadably engaged with the second female connector effectively shortening the rear needle assembly to bare the rear needle tip. 8. A method for passively activating a safety shield for a needle shield for a phlebotomy needle device comprising the steps of: providing a phlebotomy barrel having a first female connector which threadably receives a complementary first male threaded connector of a phlebotomy needle hub assembly, said first female threaded connector further comprising a proximally disposed locking member which slidably engages and thereby resists rotation of a portion of the phlebotomy needle hub assembly as said phlebotomy needle hub assembly is being threadably affixed to said phlebotomy barrel; providing the phlebotomy needle hub assembly comprising: a phlebotomy needle having a forward, distally disposed sharpened tip and a rear, proximally disposed sharpened tip; a needle hub in which said phlebotomy needle is firmly affixed, said hub comprising: the first male threaded connector part having a diameter and pitch which is compatible with being threadably affixed to said first female barrel connector; and a second female threaded connector part disposed within and aligned with said first male connector part, said second female threaded connector part having a diameter which is smaller than the first male connector part and a pitch which is substantially the same as the first male threaded connector part; a rear needle shield comprising a second male threaded connector part having a diameter and pitch which corresponds to the hub assembly second female threaded connector part and a rear shield having a length which protectively extends about and beyond the proximal sharpened tip when the phlebotomy needle hub assembly is disconnected from said phlebotomy barrel: said rear needle shield further comprising a fitting which is slidably displaced into said locking member when connection is made between the first male and female threaded connectors thereby causing said rear needle shield to resist rotation relative to the phlebotomy barrel as the rear needle assembly is threadably engaged with said phlebotomy barrel, resulting in said second male connector part being threadably engaged with the second female connector effectively shortening the rear needle assembly to bare the rear needle tip: inserting the phlebotomy needle hub assembly with the rear shield disposed about and extended over the rear needle as a safety protector into the phlebotomy barrel and threadably affixing the phlebotomy needle hub assembly to the phlebotomy barrel and shortening the phlebotomy needle hub assembly to uncover the rear needle for use in a medical procedure; and after the procedure is finished, unthreading the phlebotomy needle hub assembly from the phlebotomy barrel, thereby restoring the rear shield about and over the needle to provide a safety protector as the rear needle tip is removed from the phlebotomy barrel.

Inventors: THORNE CRAIG, THORNE GALE, THORNE, CRAIG, THORNE, GALE
Applicants: SPECIALIZED HEALTH PROD INC, SPECIALIZED HEALTH PRODUCTS, INC.
Application year: 2000
Main classification: A61M
IPC codes: A61B5, A61M5