CROSS-REFERENCE TO RELATED APPLICATIONSThis is a continuation of Ser. No. 08/398,772 filed Mar. 6, 1995 now abandoned which is a continuation of application Ser. No. 07/972,013, filed Nov. 6, 1992, now U.S. Pat. No. 5,395,347 which is a continuation-in-part of our application Ser. No. 07/610,583 filed Nov. 8, 1990, now U.S. Pat. No. 5,176,655 and is also a continuation-in-part of our pending application PCT/US91/08063 filed Nov. 6, 1991 under the Patent Cooperation Treaty.
BACKGROUND OF THE INVENTIONAt high-volume medical facilities as blood bank centers. hospitals, and the like, blood is drawn from human donors in large quantities for processing and storage. In connection therewith, small volume specimens of the blood are withdrawn from the blood collection apparatus for necessary analysis. Blood withdrawal from humans exposes the medical worker to the risk of accidental needlestick injuries preparatory to connection of blood collection equipment to the donor in the unavoidable handling of used, unshielded, blood-contaminated needles.
In current practice, blood banking services, such as the American Red Cross among others, obtain, process, and store whole blood and blood components for a variety of medical uses such as transfusions and the like. Before any such blood can be used, however, all collected blood is analyzed to characterize its immune properties or so-called "blood type". Equally or more importantly, all blood must also be pre-tested for the presence of communicable disease pathogens, such as the hepatitis virus and the human immunodeficiency virus (HIV). As is well known, HIV is the causative agent of the uniformly fatal AIDS disease in humans, and thereby mandates the safest possible environment when handling human blood.
Blood collection as now commonly practiced utilizes a system including (1) a straight metal needle whose pointed end is inserted into a human donor to access a blood vessel wherein the needle usually includes a gripping portion bonded thereto to facilitate manual manipulation; (2) a length of flexible tubing in fluid communication at one end with the non-pointed proximal end of the needle; and, (3) one or more blood storage bags connected to the other end of the tubing. Additionally, helpful agents such as citrate-phosphate dextrose (CPD) are commonly included as anti-clotting additives within the collection system to prevent coagulation of the blood and permit it to remain in fluid condition.
Accordingly, traditional blood bag collection apparatus is thus a closed, sterile system in which the blood flows from the donor's blood vessel through the tubular metal needle, through the flexible tubing and into the blood storage bag, and in the use thereof for actual blood collection does not present a significant hazard to medical personnel.
As indicated, however, it is necessary to take a small sample of collected blood for analysis to insure the integrity and quality of the bag quantity. Customarily, to obtain the test sample, the medical or health care worker initially shuts off tubing flow as by a clamp, and then grips the needle with one hand by the enlarged grasping component thereof, removing the needle from the donor. Thereafter, the exposed needle tip, which is now blood-contaminated, is inserted through a rubber stopper or seal into a sample collection test tube, and the clamp is released to permit drawing of a sample of the collected blood reversely through the needle and into the test tube usually held in the other hand.
The open manipulation of the contaminated needle between withdrawal and sample securement presents unwanted hazards to personnel in the possibility of accidental needlestick injury.
Thus, the physical movement of the contaminated needle with one hand toward and in close proximity to the other hand holding the sample collector, there is a significant probability of self-inflicted injury. In effecting the sampling, the needle point may misalign with the rubber seal and puncture the worker's hand. Additionally, upon withdrawal of the inserted needle from the sample vial the frictional resistance of the rubber stopper retarding needle withdrawal suddenly ceases as the needle pulls dear, and there is an involuntary tendency and reflex for the worker's hand holding the needle to recoil back toward the hand holding the test tube.
The actual rates and likelihood of needlestick injuries with such conventional blood collecting equipment have been well documented in a report appearing in the publication TRANSFUSIONS. Vol. 29, No. 8, October, 1989, pages 693-695, entitled "Needlestick Injuries in Blood Collection Staff--A Retrospective Analysis". Attempts to improve the present practice by using a guard mechanism to reduce the chances of accidentally puncturing the healthcare worker's fingers, especially those grasping the sample tube, have reduced but failed to eliminate the rates of such injuries. In one typical Red Cross blood collection center, for example, there are about 10 to 12 needlestick injuries annually out of a total staff of 165 individuals who are in fact using such a prior art guard device.
There is, therefore, a substantial and real need for means to eliminate the needlestick hazard and its actual threat to the health of medical workers in blood collection operations.
Concomitant to the foregoing, ease of fabrication, simplicity of assembly, and reliability of function are prime requisites of devices and equipment in the healthcare arts. To this end, the present invention embraces improved and reliable needle-carrying and manipulating elements, and modes of fabrication and assembly thereof.
SUMMARY OF THE INVENTIONThe present invention addresses this problem confronting the healthcare industry and is designed specifically to eliminate needlestick injuries of the type described in connection with blood collection.
To this end, there is provided a new and improved system which (1) shields the blood-contaminated needle simultaneously with its withdrawal from the donor, and (2) uses a separate shielded needle in a blood sample tube holder for the safe drawing of blood samples, whereby the probability of an exposed contaminated point being in any injury-causing proximity to a medical worker is virtually nil, whereby the threat to or even the fear of HIV or other disease by the worker is eliminated.
To this end, a unique and mechanically simple but reliable snap-on needle enclosing guard is provided on a specialized needle device disclosed herein, which is similar in some respects to the needle safety device as set forth in our aforenoted application Ser. No. 07/610,583 now U.S. Pat. No. 5,176,655. Thereby, upon withdrawal of the needle from the blood donor, the needle is immediately retracted within the guard and a shield positively blocks the contaminated needle point and access thereto. Two different forms of the needle assembly are provided and which have differing fabrication and use advantages.
Obviously, such protection precludes use of the same needle for the aforementioned separate sampling purposes. The invention, therefore, further embraces means to effect the necessary sampling without the use of a contaminated needle and without concomitant needlestick exposure of the worker.
BRIEF DESCRIPTION OF THE DRAWINGSThe invention will be better understood in reference to the accompanying drawings in which:
FIG. 1 is a diagrammatic illustration of prior art presently practiced blood collection technique and equipment;
FIG. 2 is an illustration of prior art sample collection in a test tube;
FIG. 3 is an overall perspective view of the blood collection system of the invention;
FIG. 4 is similar to FIG. 3 showing the apparatus with advance of the needle for insertion into the donor;
FIG. 5 is an illustration of the gripping means of the apparatus for needle insertion;
FIG. 5A is a fragmentary side elevation of the device as seen in FIG. 5;
FIG. 6A is an illustration of the system at commencement of needle withdrawal from the donor;
FIG. 6B illustrates full withdrawal of the needle and enclosure thereof with in the guard and protection of the needle point by the shield;
FIG. 7 is a perspective view of the shield spring member;
FIG. 8A is a view of the end of the guard with the needle extended therefrom but with the shield removed for clarity;
FIG. 8B is an enlarged side elevation similar to FIG. 8A but with the shield in initial position;
FIG. 8C is a view taken on the line C--C of FIG. 8B;
FIG. 8D is a fragmentary view similar to FIG. 8B but with the needle retracted and shielded;
FIG. 9A is a view similar to FIG. 8B illustrating a modified needle carrier and guard;
FIG. 9B is a view taken on the line C--C of FIG. 9A;
FIG. 9C is a section view similar to FIG. 9B but with the shield and needle removed;
FIG. 10A is a view similar to FIG. 6B but showing a modified form of gripping portion for the needle.
FIG. 10B is a side view of the modified gripping member, internal portions being shown in phantom;
FIG. 10C is a parital assembly view of a needle and its securing disc with the modified gripping member;
FIG. 10D is an assembled view of the parts of FIG. 10C; and,
FIG. 10E are front and side views of the needle securing disc.
DESCRIPTION OF THE PREFERRED EMBODIMENTSReferring to the drawings, there is generally indicated in FIGS. 1 and 2 a typical widely used blood collection and blood banking system which in use presents the aforementioned safety and needlestick hazards. Thus, a hollowmetal cannula needle 10 having a taperedpoint 12 has a finger-grippableenlarged annulus 14 secured to a proximal needle portion to facilitate handling and maneuvering of the needle in the collection and sampling process.
The donor's skin is punctured by thepoint 12 and the same is the positioned in a blood vessel. Theproximal end 16 of the needle is bonded, clamped, or otherwise secured in known manner toflexible tubing 18, the opposite end of which communicates with ablood collection bag 20, whereby the needle, tubing, and bag form a closed passageway for the flow of blood. Clamp means 22 of known form is provided alongtubing 18 to regulate or shut off blood flow as may be required from time to time during collection or thereafter.
There is also provided a standardblood specimen tube 24 having a usualrubber seal stopper 26. Such sealed tubes are conventionally provided on manufacture with a partial vacuum in itsinternal chamber 28 to facilitate the drawing of blood thereinto.Such specimen tubes 24 are routinely used for taking small volume blood samples for analysis from donor blood obtained for blood bank processing and storage purposes.
The current practice of obtaining the blood samples entails a procedure which is in fact hazardous to health care workers. After the desired quantity of blood is collected from the donor intobag 20,clamp 22 is used to shut off flow. Thefingers 30 of one hand of the worker grasp enlargedcollar 14 and removeneedle 10 from the donor and move the now-contaminatedneedle point 12 through space to aim and position thepoint 12 to puncturestopper seal 26 of thespecimen tube 24, the latter being held byfingers 32 of the other hand of the worker, as seen in FIG. 2. Theclamp 22 is released, and a small quantity of blood is drawn in reverse flow from thetubing 18 into the partially evacuatedchamber 28 inspecimen tube 24.
Apart from other real possibilities of mishandling the contaminatedneedle tip 12 during donor withdrawal and holding the same openly as the specimen tube is manually positioned, it is principally the manipulation ofneedle 10 for alignment and entry intospecimen test tube 24 that constitutes a significant danger of accidental needlestick injury to the health care worker. In necessarily moving a blood-contaminated needle in one hand directly toward the other hand holding the tube, and with sufficient moving force to penetrate thestopper 26, the danger of self-inflicted injury increases substantially. Thus, theneedle point 12 may miss the small-diameter stopper entirely and puncture thefingers 32. Alternatively, the needle point may be improperly positioned at an angle, on thestopper 26 and with stopper-puncturing force applied the needle may slip laterally from the stopper and puncture the worker's hand. These possibilities are entirely apart from other imperfections of the worker as relatively poor eyesight, nervousness, and the like.
Additionally, as earlier noted, there exists the threat of injury in retracting the needle from thevial stopper 26 from a recoil-like motion immediately after theneedle 10 is pulled out ofstopper 26 and the previously existing frictional resistance of the rubber to needle withdrawal suddenly ceases. As the blood-contaminated needle then starts to "fly" 60 rearwardly on leaving the stopper, there is a frequent immediate reflex by the worker to stop the rearward motion and abruptly move the needle again toward thefingers 32 holding the specimen tube with risk of scratching these fingers with the needle.
The se difficulties are obviated by the apparatus and system of FIGS. 3-9. Thus, therein, the blood-contaminated needle is shielded simultaneously with its withdrawal from the donor whereby no inadvertent puncture can occur, and a separate shielded needle in a blood sample tube holder is used for safe drawing of the blood sample.
One form of the invention is seen in FIG. 3 whereinneedle cannula 40, somewhat similarly toneedle 10 in FIG. 1, includes theusual needle point 42 and further includes a special gripping portion orbase member 44 bonded therearound near the needleproximal end 46, which latter is secured in usual manner to the flexibleblood collection tubing 48 having itsinternal flow passage 50.Tubing 48 terminates into onebranch end 51 of a Y-connector 52 of well-known form, while a length oftubing 54 extends from theother end 56 of the Y-fitting 52 to communicate withblood bag 58. Well-known flow controladjustable clamps 70, 70 are provided along the length oftubing 48 and 54.
The Y-fitting includes asecond branch 60 providing asampling port 62 communicating with thetubing 48. Theport 62 is a conventional medical industry fitting, commonly known as a Luer female fitting. Theport 62 is adapted to cooperate with a standard bloodcollection tube holder 64 having a standard multiple sampleblood collection needle 68 with a rubber sleeve 72 associated with a male Luer fitting 74, which latter forms a dripless collection withfemale port 62. Prior to sample collection intotube holder 64, the fitting 74 is inserted into theport 62 to prevent drippage until the collection tube is inserted intoholder 64 in known manner to open access toneedle 68.
The safety andguard assembly 80 in FIGS. 3 and 4 carryingneedle 40 in overall respects is in accordance with that disclosed and claimed in U.S. Pat. No. 5,176,655. The same includes a needle shielding or guidebody 82 having an opening shown as a bore extending from port means in its front surface ordistal end 84 toproximal end 86 within which needle 40 is slidably received. While thebody 82 is shown for illustrative purposes as being of square or rectangular cross-section, the particular configuration may vary within the limits of the required structure and function thereof. Similarly, the assembly may readily be fabricated as by molding from plastic, such as polyethylene, polyvinyl chloride, or the like.
The rear portion offront guide 82 may be provided with laterally extending flexiblewinglike members 88, and flexible restraints or tethers 90 extending fromwings 88 interconnect theguide 82 and thebase section 44 which is bonded toneedle 40. In the absence ofwings 88, thetethers 90 may be connected directly to thebody 82. Thewings 88 also include respectiveupstanding lugs 102, 102 outwardly from theguide body 82 for cooperation in use with anupstanding lug 104 onbase section 44, as described further hereinafter.
Preferably,needle guide body 82 is provided on either side thereof with a series of laterally extending projections orlug members 92 and 94 for cooperative abutment withgripping legs 96 of a specially configuredleaf spring 100. Obviously, thespring legs 96 could cooperate with other forms of abutments than flange-like projections, as recesses in theguide body 82, for example.
Thespring 100 forms an essential element of the safety needle assembly. Thus, as shown in FIG. 3, the spring includes an inturnedimperforate blocking flange 98 at its forward end, which rests upon and is biased transversely againstneedle 40 when the needle is extended for use as shown. As seen in FIG. 3, theneedle 40 is so positioned relative to theimperforate flange 98 that theflange 98 bears against the needle on the side area thereof corresponding to the maximum length of the needle at the pointedtip 42 of the conventionally tapered or bevelled needle. Theproximal end 101 ofspring 100 is also angled and stressed against theguide body 82, the spring being maintained in position by the inwardlyangled portions 97 oflegs 96 bearing againstprojections 94.
Uniquely, the one-piece spring 100 facilitates assembly of the unit, as the grippinglegs 97 thereof readily snap past thebody projections 94, and positively hold the spring on the body with no chance or accidental removal. The assembly is thus a one-step process minimizing cost with no sacrifice of safety or reliability. As above noted, theprojections 94 may be replaced by molded indentations in thebody 82 with equally effective results. The forward orvertical projections 92 preclude any likelihood that the spring could slide forwardly on the body to expose excessively the needle, while the safety flange obviously precludes rearward movement of the spring.
Accordingly, theneedle assembly 80 comprises theneedle 40, thebody 82 slidably crying the needle, theflexible tethers 90, therearmost base section 44 bonded to the needle, and thespring 100.
In use, and as set forth in applicants, U.S. Pat. No. 5,176,655, during preparation for needle insertion through the skin of the blood donor, theassembly 80 is as shown in FIG. 4 with thewings 88 initially flexed sufficiently downwardly to permitbase section 44 to closely approach or abut the forwardneedle guide body 82 from the former position of FIG. 3. Thereupon, thewings 88 are flexed upwardly and gripped as seen in FIG. 5. In so doing, the wing lugs 102 are repositioned to be disposed immediately rearwardly of thebase member lug 104 as best seen in FIG. 5a. Thereupon, with forward movement by thefingers gripping wings 88, base member will move forwardly therewith to insert the needle point into the donor.
While the foregoing is a positive and unitary handling of theassembly 80 during needle insertion, under particular conditions with a donor or patient, the medical technician may leave the wings down and separately manipulate thebase member 44 and the needle carried thereby to insert the needle without concomitant interlocked orinterengaged lugs 102, 104.
As similarly taught in U.S. Pat. No. 5,176,655 safe needle withdrawal from the donor's (or patient's) blood vessel is effected by holding theneedly shielding body 82 stationary adjacent the needle skin entry point and withwings 88 relaxed to removelugs 102 outwardly from behindlug 104. Thereupon, as shown in FIG. 6A, the base section 44 (or thetubing 48 thereat) is pulled in a proximal direction whileneedle guide body 82 is stationary thereby causingneedle 40 to slide rearwardly in the proximal direction through the guideway therefor inbody 82.
Thus, with the construction described, immediately as theneedlepoint 42 passes rearwardly of the distal end ofspring 100, the spring relaxes and snaps theangled face 98 thereof transversely of the guide body forward face 84 and securely encloses the needlepoint withinguide body 82 as seen in FIG. 6D. It should be borne in mind that as compared to the drawing illustrations, the actual device of the invention is quite small and the needlepoint is absolutely without capability of exposure and contact with medical or donor personnel once retracted and blocked, whereby needlestick injury is positively prevented in a simple and effective manner.
More particularly, and this is an outstanding safety feature of the invention, with the blockingflange face 98 immediately adjacent the forward surface of the body at 84, as soon as the needle passes behind theflange 98, the spring snaps the flange forward surface over the 84 of the body into needle-blocking position and positively precludes reemergence of the contaminated needle point from thebody 82 and thus needlestick injury is absolutely avoided. While the needle may be withdrawn further into thebody 82, such extra movement is unnecessary as the safety spring acts on and over theend face 84 of the body at the immediate point of potential emergence of the contaminated needle. The fully withdrawn and safety-shielded needle is shown in FIG. 6B, for example.
This contrasts with other attempts to reduce injury wherein the needle must be withdrawn at least a minimum predetermined distance beyond the exit from the tubular body. With such equipment, a visual perusal indicates that the needle is not exposed, and therefore may be considered to be safe. In fact, if the needle is not retracted sufficiently inwardly from the exit aperture, it is still able to be accidentally projected to cause hazard and is not securely in a safe position immediately upon its retraction inside the carrying body, with no further retraction being required Such devices are known in the prior art.
A modifiedbody 110 for receiving the needle is shown in FIGS. 9A-C in lieu of thebody 82. The same is not provided with a tubular bore as in FIG. 3, but with an open-sided U- or V-configuration, as well seen in FIG. 9B. In so doing, thespring 100 has a modified rear tang 101a dimensioned to fit within thebody 110 and bear against theneedle 40 therein. Along with theforward safety shield 98 of the spring, the needle is held firmly in the body, and upon snap operation ofshield 98 as heretofore, the needle is made safe being blocked at its proximal end, gripped at 101a, and overlaid by the body generally of the spring, whereby access cannot be had to the needle point. In other respects the elements of theassembly 80 are essentially the same. It will be evident that the U-shaped body facilitates ready assembly of the needle system.
FIGS. 10A-10E illustrate a modified form of gripping member and a simplified assembly technique for associating theneedle 40 therewith. Thus, the modifiedgripping element 120 is similar to that at 44 in FIG. 3 in being of polymeric material and generally of cylindrical or polygonal external configuration and includes a similar upstanding wing-engagingflange 104. Internally thereof, however, instead of a simple through bore as in FIG. 3 for receiving and bonding as by cement to theneedle 40, only a short needle-diameter bore portion 122 is provided in the distal end thereof, themember 120 being countersunk therebehind to anenlarged diameter chamber 124 having an internalfront wall 126.
Cooperating therewith is needle-gripping and securingdisc 128 having a diameter substantially that ofchamber 124, and having a hole oraperture 129 therethrough bounded by short radial cuts 130.Hole 129 is of a diameter slightly less than that of theneedle 40 whereby thecuts 130 permit slight flexing of the disc as the needle is inserted therethrough in a snug mechanical interference fit
Additionally,disc 128, which is preferably fabricated from thin flexible metal, is provided at its periphery with a plurality of rearwardly directed barbs or tangs 132. Accordingly, the disc is assembled with grippingmember 120 by axially advancing the disc intochamber 124 againstfront wall 126, and is locked therein by the presence of thebarbs 132 whereby the disc cannot be removed and the needle is securely positioned. Further, a liquid bonding agent is applied about the needle at 134 (FIG. 10D) at its exit frommember 120, thereby sealing the needle to thebase gripping member 120.
In this manner the needle is reliably secured to themember 120 both by the mechanical-interaction of thedisc 128 withbase 120 and also by thebonding material 134.
Accordingly, in summary, it will be seen that in use withcannula 40 inserted into the patient, blood is collected intobag 58 as desired, and then theclamp 70 is shut and theneedle 68 opened onto a collection tube for desired sampling without removal of theneedle 40 from the patient. As many samples may be taken as desired with manipulation of theramps 70, 70 prior to retraction and immediate safetying of theneedle 40 without reuse thereof or hazard therefrom. The healthcare worker at no time has to manipulate an unshielded blood-contaminated needle whether collecting blood or taking samples for analysis.
The assembly of the present invention lends itself to ready fabrication, as is evident from the foregoing. Thus, thebody 82, grippingportion 44, tethers 90 andwings 88 if used may be simultaneously molded, as by injection molding, of polymeric material, as polyvinyl chloride. The unit assembly may then have theneedle 40 appropriately positioned in thebody 82 and the grippingportion 44 for bonding of the distal needle portion tomember 44. If the modifiedU-body 110 of FIG. 9 is employed, the needle need not necessarily be propositioned therein, but all elements other thanmember 44 can be flexed to one side while the needle is fixed to 44. In either case, thereafter thespring 100 is snap-fitted onto the body, and the assembly is complete and ready to use. The same advantages in assembly accrue with the needle securement technique of FIGS. 10 A-D, as above discussed.
While we have disclosed our invention in preferred embodiments, it is evident that the concepts and techniques thereof may be employed in differing arrangements, such as indwelling needles, tubing, biological fluid reservoir, drainage systems for pleural fluid drainage, and the like, within the scope of the invention as defined in the appended claims.