OA12964A - IV Catheter introducer with retractable needle. - Google Patents

Description

012964

IN THE UNITED STATES PATENT AND TRADEMARK OFFICE

IV CATHETER INTRODUCER WITH RETRACTABLE NEEDLE

BACKGROUND OF THE INVENTION 1. Field of the Invention [00001] The invention is a medical device used to insert a cathéter into a patient'sbody, especially for the intravenous delivery of a fluid. More particularly, the invention isa cathéter introducer having a rétractable needle that prevents reuse and avoids needlestick injuries to medical personnel and others. 2. Description of Related Art [00002] Cathéter insertion devices are well known. When a cathéter is insertedinto a patient for the intravenous delivery of a fluid, a disposable needle passing throughthe cathéter is utilized to puncture a vein to permit entry of the cathéter. The needle isthen withdrawn, leaving the cathéter in place for connection to an IV bag or bottle, or tobe capped for later use.

[00003] In recent years, because of the prevalence of blood-borne pathogens suchas HIV and hepatitis, there has been an increasing need for cathéter introducers thatprevent accidentai needle stick injuries to medical personnel and to other employéeswho handle trash, laundry or other refuse containing used needles. As a resuit, newProducts hâve been designed that incorporate spécial needle covers or mechanisms forretracting the needle following use. Such devices are disclosed, for example, in UnitedStates Patent Nos. 4,747,831; 4,828,548; 5,129,884; 5,501,675; 5,817,058 and5,989,220. Many of the prior art devices contain numerous complicated parts thatsubstantially increase manufacturing costs and interfère with the user’s ability to feelwhen the needle is properly inserted into the patient. Other devices require two-handed 012964 operation or are prone to prématuré needle retraction during shipment, storage andhandling.

[00004] An IV cathéter introducer is therefore needed that can be manufacturedeconomically and reliably at high speed, that will not retract the needle prematurely, that 5 can be operated with one hand, and that will fulfy protect the user and others fromaccidentai sticks and exposure to blood-bome pathogens. These and other advantagesare provided by the invention disclosed below. 012964

SUMMARY OF THE INVENTION (OÛ005J A single use IV cathéter introducer is disclosed that provides significantadvantages over prior art devices, even those comprising rétractable needles. Principalstructural improvements include a reliable detent structure that holds the needle holderand plunger in proper positional alignment prior to needle retraction; following insertionof the cathéter; a plunger end cap that vents air displaced from inside the plunger boreduring needle retraction; and a transparent viewing area that permits the user to viewthe flash chamber of the needle holder more easily through the clear plastic housing.Other improvements include barrel wings that facilitate one-handed operation andprevent the cathéter introducer from rolling when placed on a surface, a needle holderopening that is tapered to permit easy insertion of the flash chamber plug duringmanufacture, and a needle holder configuration that prevents the blunt needle end frombeing occluded during manufacture and makes the flow of blood into the flash chambermore visible.

[00006] The IV cathéter introducers of the invention hâve few parts, can bemanufactured reliably at high speed, significantly reduce the likelihood of prématuréneedle retraction during storage and handling, are easily useable in one hand, and willprotect medical and other ancillary personnel from accidentai needle sticks and thepossibility of résultant infection by blood-borne pathogens. Use of the présent inventionalso affords significant économie benefits to health care providers and insurers throughreduced testing and follow-up costs. 012964

BRIEF DESCRIPTION OF THE DRAWINGS

[00007] The apparatus of the invention is further described and explained inrelation to the following figures of the drawing wherein: FIG. 1 is a simplified perspective view of the IV cathéter introducer of theinvention with the cathéter needle ready for use; FIG. 2 is an enlarged, cross-sectional élévation view taken along line 2—2.of FIG. 1; FIG. 3 is a view as in FIG. 2, but with the needle retracted following use; FIG. 4 is an enlarged detail view taken from FIG. 2, and depicts the detentstructure holding the landed front opening of the plunger tube in the desired positionrelative to the rétractable needle holder prior to retraction; FIG. 5 is an enlarged plan view of the vented plunger end cap; and FIG. 6 is a cross-sectional élévation view taken along line 6—6 of FIG. 5.

Like référencé numerals are used to describe like parts in ail figures of thedrawings. 012964

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[00008] Referring to FIGS. 1-2, IV cathéter introducer 10 preferably comprisestubular plastic housing 12, needle holder assembly 14, retraction spring 16, plungerassembly 18 and IV cathetër 20. Plastic housing 12 has an internai bore 22 thatnarrows progressively between open end 24 and reduced diameter tip 26, except for ashort distance below inwardly projecting annular ring 102, as described below. Plastichousing 12 is preferably injection molded from a substantially transparent polymericresin such as polycarbonate to permit easy viewing through sidewall 28. The outsidediameter of housing 12 generally follows the tapered narrowing of internai bore 22, sothat sidewall 28 has a substantially constant thickness except where it flares outwardly.to form laterally extending wings 30 and to provide a longitudinally spaced sériés ofannular ridges 31 nearer to tip 26 to create a textured grippirtg area for the fingers of theuser.

[00009] Needle holder assembly 14 is retractably mounted within the lower portionof housing 12 and preferably comprises a tapered, elongate tubular body 32, needle 34and porous plug 36. Body 32 of needle holder assembly 14 is preferably injectionmolded from a substantially transparent polymeric resin such as polycarbonate andcomprises a tapering sidewall of substantially constant thickness that further definesflash chamber 42, spring guide section 44 and needle support section 46, each of whichhas a progressively smaller diameter. Tubular body 32 of needle holder assembly 14 isdesirably shaped so as to permit needle holder assembly 14 to be inserted into slidingengagement with housing 12 during assembly, as described in greater detail below.The upper end portion of tubular body 32 is adapted to releasably engage lower end 56of plunger assembly 18 as described below in relation to FIG. 4. As viewed in FIG. 2,retraction spring 16 is confined within annular space 90 between housing 12 and springguide section 44 of tubular body 32, and is held in compression between downwardlyfacing shoulder 92 of tubular body 32 and upwardly facing shoulder 94 of housing 12.Although this embodiment uses a compressed spring that exerts a retraction force byexpanding, other similarly effective means such as an extension spring can likewise beused to retract the needle. 012964 [00010] Needle 34 is hollow and has a beveled end 48, which is inserted into apatient's vein during use, and a blunt end 50 that extends into flash chamber 42. Aîongitudinally extending bore provides fluid communication through needle 34 betweenbeveled end 48 and blunt end 50. Needle 34 is preferably insert molded into needlesupport section 46 of tubular body 32 but can be glued or sonically welded into body 32if desired. A tapered needle insertion opening 47 is desirably provided at the lower endof needle support section 46 if needle 34 is to be inserted after molding needle supportsection 46. By using a needle 34 that is long enough to extend into flash chamber 42,the bore of needle 34 will not become occluded during insert molding. Also, because aminor amount of blood flows upwardly through needle 34 into flash chamber 42whenever needle 34 is introduced into the vein of a patient, making blunt end 50 visiblein flash chamber 42 permits the user to view blood as soon as it enters flash chamber42, confirming to the user that needle 34 is properly positioned inside the vein.

[00011] At the top of flash chamber 42 of needle holder assembly 14, end 52 oftubular body 32 is blocked with porous plug 36 that frictionally engages the walls ofannular recess 55 in body 32. The insertion of porous plug 36 into tubular body 32 ispreferably made easier by tapered inside wall 54 adjacent to end 52. Porous plug 36 ispreferably made of any suitable porous material that will allow air to be displaced out ofneedle 34 and flash chamber 42 by blood rising through needle 34 following insertioninto a vein, but will prevent any such minor amount of blood from exiting flash chamber42. A significant advantage of IV cathéter introducer 10 disclosed herein is that flashchamber 42 is visible through only two layers of ciear plastic: the transparent wall oftubular body 32 around flash chamber 42; and the transparent wall of housing 12. Withmany devices disclosed in the prior art, the user must peer through three or more plasticlayers to view the flash chamber, making it more difficult to observe when blood beginsentering the chamber.

[00012] Plunger assembly 18 preferably comprises a polymeric plunger tube 40having a substantially cylindricai sidewall with a lower end portion 56 that is proximal toend 52 of tubular body 32 of needle holder assembly 14, and an upper end portion 58that projects Iongitudinally outward from open end 24 of housing 12. Plunger tube 40 is 012964 preferably injection molded from a polymeric resin, and most preferably, from asubstantially transparent polymer such as polycarbonate. Lower end portion 56 ofplunger assembly 18 releasably engages tubular body 32 of needle holder assembly 14and coopérâtes with needle holder assembly 14 to form the detent structure of theinvention as described in grëater detail below in relation to FIG. 4. Upper end portion58 of plunger tube 40 preferably comprises a small, radially extending annular Aangè 60surrounding a tapered annular recess 62 in surface 64 that receives and frictionallyengages end cap 66, which is further described and explained in relation to FIGS. 5 and 6. With IV cathéter introducer 10 prepared for use, upper end 58 of plunger assembly18 desirably extends from about 1.5 to about 3 inches from housing 12 so that upperend 58 can be nestled against the palm of the hand while the user’s Angers grip wings30 or annular ridges 31 of housing 12 to facilitate one-handed operation. Pulling backon housing 12 with the Angers triggers retraction of needle holder assembly 14, asdiscussed below in relation to FIG. 3.

[00013] Referring to FIGS. 5 and 6, end cap 66 is preferably molded from apolymeric resin and, most preferably, from a resin that is pigmented in a color chosen tocorrespond to the gauge of needle 34, shown in FIGS. 1-2, to assist users in readilydifferentiating among IV cathéter introducers 10 having different sized needles. Endcap 66 preferably further comprises a substantially continuous, circular end wall 68connected to a longitudinally extending annular skirt 70 that is inwardly tapered toprovide contacting frictional engagement with annular recess 62 of plunger tube 40 aspreviously described. It should be understood that there are many ways of engagingend cap 66 into upper end portion 58 of plunger tube 40. End cap 66 may be glued,snapped-on, sonically welded, dual shot molded or engaged by any other similarlyeffective means. Dual shot molding refers to any molding process that allows differentmaterials or different colored matériels to be molded concurrently. Vent hole 72 ispreferably centrally disposed in end wall 68 and is desirably surrounded by surfacerelief features such as a plurality of outwardly extending molded ribs 74 that extendacross surface 68. Ribs 74 are preferably of sufficient number, spacing and height thatvent hole 72 is not blocked by the hand of the user, even when part of the hand isplaced over end cap 66 during operation of IV cathéter introducer 10. Vent hole 72 is 012964 preferably large enough to rapidly vent the volume of air displaced from retraction cavity76 when needle holder assembly 14 is retracted into plunger tube 40 following insertionof the cathéter.

[00014] Referring again to FIGS. 1-2, IV cathéter 20 preferably includes a flexiblerubber or plastic cannula 78 and a hub 80 having a needle channel 82 and a tubularsection 84 with an annular fiange 86 defining an openlng 88 having a diameter such thatopening 88 will receive and frictionally engage tip 26 of housing 12. At the end ofcannula 78 is an inwardly tapered end 81 that provides an interférence fit near beveledend 48 of needle 34. During the attachment of hub 80 to tip 26, needle 34 is insertedthrough flexible cannula 78 and inwardly tapered end 81, with beveled end 48 extendingslightly beyond the inwardly tapered end 81. The inside diameter of cannula 78 ispreferably slightly greater than the outside diameter of needle 34 to permit easyretraction of needle 34 through cannula 78 following insertion. Hub 80 is preferably alsoadapted for easy connection to a convention IV tubing connector following retraction ofneedle 34 and removal of tip 26 from tubular section 84 of hub 80.

[00015] Referring to FIG. 2, IV cathéter introducer 10 of the invention is preferablyassembled by dropping retraction spring 16 through opening 22 into housing 12.Rétraction spring 16, which is a coil spring biased against compression, preferably hasa diameter that causes it to seat just above inclined annular shoulder 94 inside housing12, where it is supported in substantially vertical alignment by section 33 of sidewall 28.Pre-manufactured needle holder assembly 14 is then inserted downwardly throughopen end 22 of housing 12, with beveled end 48 of needle 34 passing downwardlythrough retraction spring 16 and tip 26 of housing 12, until inclined annular shoulder 96of tubular body 32 abuts against shoulder 94 of housing 12. Alternative^, spring 16 canbe placed over needle holder assembly 14 prior to insertion of needle holder assembly14 into housing 12. Also, if desired, needle 34 can be glued or sonically welded intoneedle holder assembly 14 after needle holder assembly 14 is inserted into housing 12.Inclined annular shoulder 92 of tubular body 32 preferably will not contact inclinedannular shoulder 98, to permit shoulder 96 to seat properly against shoulder 94. 012964 [00016] Referring to FIGS. 2 and 4, lower end portion 56 of pre-manufacturedplunger assembly 18 is next introduced into housing 12 through opening 22. As plungertube 40 travels downwardly into housing 12, nose 104 of plunger tube 40 reaches andslides over end 52 of tubular body 32 of needle holder assembly 14. When nose 104reaches end 52, radially extending annular boss 100 on plunger tube 40 is still disposedabove inwardly projecting annular ring 102 of housing 12, and the inside diameter ofplunger tube 40 at nose 104 is sufficiently greaterthan the outside diameter of end 52 topermit lower end portion 56 of plunger tube 40 to slidably engage the portion of tubularbody 32 that is adjacent to end 52. As plunger assembly 18 is inserted farther intohousing 12, annular boss 100 engages and overrides annular ring 102. Annular ring102 then resists rearward movement of plunger tube assembly 18 and combined needleholder assembly 14 once they are installée! in the housing with the needle extended foruse. If there is an attempt to withdraw the plunger tube assembly 18 from housing 12,the shoulder of annular boss 100 will contact the shoulder of annular ring 102 andprevent the withdrawal unless there is an exertion of substantiel force. However,. itshould be understood that annular ring 102 is desirably sufficiently small to allow for thewithdrawal of a molding tool during the manufacturing process. Referring to FIG. 4, adetail view taken from FIG. 2, plunger tube 40 continues to slide downwardly overtubular body 32 of the needle holder assembly until inwardly facing annular boss 106 onthe inside surface of lower end portion 56 reaches and snaps into engagement withcooperatively sized and aligned, outwardly facing annular recess 108 of tubular body 32. Referring to FIGS. 2 and 4, the configuration and dimensions of annular boss 106and annular recess 108 cause boss 106 to be biased radially inward into annular recess108.

[00017] It should be understood that boss 106 on the inside of plunger tube 40, is25 not required to be circumferentially coextensive with annular recess 108 of tubular body32. Thus, for example, boss 106 can instead comprise a circumferentially spaced arrayof discrète, inwardly extending bumps that are biased Into engagement with recess 108.It is preferred, however, that recess 108 extend completeiy around tubular body so thatthe slidable engagement between plunger tube 40 and tubular body 32 does not require

JW a spécifie rotational alignaient between the two parts. The configuration and 012964 dimensions of boss 106 and recess 108 are preferably such that the force required toslidably disengage boss 106 from recess 108 by forcing plunger tube 40 farther downinto housing 12 is greater than the biasing force being exerted against needle hoiderassembly 14 by compressed retraction spring 16 and by the additiona! force that isr exerted upwardly on the needle 34 during cathéter insertion procedures. IV cathéter 20can be assembled to tip 26 of housing 12 prior to the insertion of needle hoiderassembly 14 and plunger assembly 18 into housing 12. Alternatively, plunger assembly 18 and needle hoider assembly 14 (sometimes referred to as a needle supportassembly) can also be assembled to each other prior to insertion into housing 12. Thefrictional engagement between boss 106 and recess 108 when they are cooperativelyengaged is preferably sufficient to permit needle hoider assembly 14 and plungerassembly 18 to be inserted together into housing 12.

[00018] Beveled needle end 48 and a portion of cannula 78 are desirably insertedinto a patient’s vein while grasping annular ridges 31 of housing 12 with the thumb andfingers. Following insertion of the cathéter into a patient, needle hoider assembly 14 isretracted by grasping wings 30 or annular ridges 31 with one’s fingers, or thumb andfingers, and then using the palm or heel of the hand against end cap 66 to force plungertube 40 farther down into housing 12. When this occurs, the frictional engagementbetween boss 106 and recess 108, as seen in FIG. 4, is over-pressured, causing boss 20 106 to ride up onto surface 112 of tubular body 32. Continued downward movement of plunger tube 40 relative to tubular body 32, which is firmly seated against housing 12,causes boss 106 to drop off inclined shoulder 114 of tubular body 32. When thisoccurs, there is no remaining significant frictional force being exerted againstcompressed retraction spring 16, and spring 16 rapidly expands, causing needle hoiderassembly 14 to be propelled upwardly into retraction cavity 76, simultaneouslywithdrawing needle 34 at least to a position where beveled end 48 is withdrawn intohousing 12.

[00019] Referring to FIG. 3, retraction spring 16 is fully expanded and top end 52of needle hoider assembly 14 is at least partially withdrawn into rétraction cavity 76. Airpreviously présent in retraction' cavity 76 of plunger tube 40 has been vented through 10 012964 vent hole 72 as needle holder assembly 14 moved upwardly within the cavity inresponse to expansion by rétraction spring 16. Top end 52 of needle holder assembly14 has moved upward within retraction cavity 76 sufficiently that beveled end 48 ofneedle 34 is withdrawn into housing 12. When needle 34 is in the position shown inFIG. 3, tip 26 of housing 12 can be safely detached from IV hub 80.

[00020] The improved IV cathéter introducer of the invention is well suited forautomated manufacture and assembly. Aside from the cathéter, needle and spring,only a housing, rétractable needle holder and a capped, vented plunger tube areneeded. Although housing 12 can be made in a straight configuration with a straightinternai wall, it is preferably made with a stepped configuration that, with the exceptionof the lower shoulder of annular ring 102, tapers inwardly from top to bottom. This tapermakes it easy to withdraw a core mandrel used in the molding process. Although notillustrated in the drawings, it should be understood that beveled end 48 of needle 34 ispreferably protected during the manufacturing process, shipping and storage by atubular cover that slides upwardly over the outside of cannula 78, preventing the needlefrom being damaged.

[00021] An important aspect of the subject IV cathéter introducer is the fact thatthe operator can conveniently operate the rétractable introducer structure with onehand. One handed operation is possible because the plunger tube desirably extendsabout 1.5 to about 3 inches past where the wings of the housing are located. Thisallows force to be applied against the plunger tube by the fleshy part of the palm whileusing the fingers behind the wings or the annular ridges of the housing to resist theforce and smoothiy initiate retraction. The other hand remains free to grasp the hub ofthe cathéter. Tirning for freeing the hub from the introducer device and attaching an IVtube to the hub is under complété control of the operator. In one motion, the hub of thecathéter can be separated from the insertion device, which can then be safely set asidewhile the connection is then made to the IV tube or other device that is to be connectedto the patient. The cathéter introducer can be safely set aside without concern onto abed or tray, because the needle has already been safely retracted before the cathéterassembly is disconnected from the housing. When the fingers pull back on the wings or 11 012964 annular ridges of the housing to trigger retraction, the operator can both hear and seethat the needle is safely retracted and immediately disengage and safely set aside thedevice to free his hand for use in making the necessary IV connection before loss offluid from the patient occurs.. 5 [00022] The IV cathéter introducer of the invention does not hâve to resist as much force imposed by the needle on the rétraction parts as does a conventionalsyringe that is required to puncture a rubber seal commonly used on vials.Consequently, the rétractable parts need only be able to resist the force encounteredduring normal clinical use without retracting. With the apparatus disclosed herein, dimensional tolérances and différentiel thermal expansion rates are less critical than

K with devices where the only frictional engagement is provided by surface-to-surfacecontact between smooth facing surfaces.

[00023] The IV cathéter introducer disclosed herein is less likely to retract theneedle prematurely than prior art devices, even when subjected to rough handling and widely varying températures and humidity during shipment and storage prior to use. 15

The invention has a simple, streamlined shape and a retraction spring that is simpler tooperate and more reliable than others previously used. The device can be operatedwith one hand in any rotational position where the wings are accessible because it hasno external latches that require placing the device in a particular orientation. Further, 20 the wings prevent the cathéter introducer from rolling when placed on an obliquesurface. With the device held in the hand, the retraction force is applied linearly alongthe main longitudinal axis. A very short stroke movement is sufficient to triggerretraction. Successful rétraction is noted both visually and audibly because the operatorcan easily see the retracted parts, in the hoüsing and rétraction créâtes an unobtrusive noise. 25 [00024] Other alterations and modifications of the preferred embodiment describedabove will become apparent to those of ordinary skill in the art upon reading thisdisclosure, and it is intended that the scope of the invention disclosed herein be limited 12 012964 only by the broadest interprétation of the appended daims to which the inventor islegally entitled. 13

Claims (66)

012964 CLAIMS: 10 15

1. An IV cathéter introducer comprising a tubular housing; a needle holderassembly having a tubular body slidably engaged inside the housing; a retractionmechanism seated in an annular space between the housing and the needle holderassembly; a plunger assembly having a plunger tube releasably engaged with thetubular body inside the housing; and a cathéter attached by frictional engagement to thetubular hpusing; wherein the tubular body comprises an outwardly facing annular recess proximal to theplunger tube; the plunger tube comprises an outwardly extending annular boss proximal to thetubular body; and the annular recess and annular boss are biased into releasable engagement.

2. The IV cathéter introducer of daim 1 wherein the retraction mechanism isa spring.

3, The IV cathéter introducer of daim 2 wherein the spring is a compressed spring.

4. The IV cathéter introducer of daim 1 wherein the tubular housing andtubular body are made of clear plastic.

5. The IV cathéter introducer of daim 4 wherein the clear plastic comprisespolycarbonate.

6. The IV cathéter introducer of daim 1 wherein the plunger tube has avented end that is distal to the tubular body.

7. The IV cathéter introducer of daim 6 wherein the vented end comprises aplastic end cap. 14 012964

8. The IV cathéter introducer of claim 7 wherein the plastic end cap iscolored.

9. The IV cathéter introducer of claim 6 wherein the vented end comprisesan end cap having a vent hole and irregular surface features surrounding the vent hole.

10. The IV cathéter introducer of claim 6 wherein the vented end comprisesan end cap having an annular skirt that frictionally engages the plunger tube.

11. The IV cathéter introducer of claim 6 wherein the vented end comprises aglued end cap.

12. The IV cathéter introducer of claim 6 wherein the vented end comprises asonically welded end cap.

13. The IV cathéter introducer of claim 6 wherein the vented end comprisesan end cap that is dual shot molded onto the plunger tube.

14. The IV cathéter introducer of claim 4 wherein the needle holder assemblycomprises a flash chamber with an interior space that is viewable through no more thantwo layers ofclear plastic.

15. The IV cathéter introducer of claim 1 wherein the needle holder assemblyhas an insert molded needle.

16. The IV cathéter introducer of claim 1 wherein a needle is glued intoneedle holder assembly.

17. The IV cathéter introducer of claim 1 wherein a needle is sonically weldedinto needle holder assembly. 15 012964

18. The IV cathéter introducer of claim 14 wherein the needle holder assemblyhas a needle with an end that extends into the flash chamber.

19. The IV cathéter introducer of claim 1 wherein the tubular body has aplugged end comprising an inwardly facing annular recess in the tubular body and aporous plug inserted into frictional engagement with the annular recess.

20; - The IV cathéter introducer of claim 19 wherein the annular recess in thetubular body is adjacent to an outwardly tapered interior wall section of the tubular body.

21. The IV cathéter introducer of claim 1 wherein the tubular body furthercomprises a reduced diameter section that is longitudinally spaced apart from theannular recess, and wherein the plunger tube is disengageable from the tubular body byan application of force to the plunger tube that is suffirent to slide the annular boss outof the annular recess and along the tubular body to a point opposite the reduceddiameter section.

22. The IV cathéter introducer of claim 21 wherein the needle holder assemblyis forced into the plunger tube by the retraction mechanism when the annular boss isopposite the reduced diameter section.

23. The IV cathéter introducer of claim 1 wherein the tubular housingcomprises an open end and a pluraîity of laterally extending wings adjacent to the openend.

24. The IV cathéter introducer of claim 1 wherein the cathéter furthercomprises a cannuia depending from a hub attachable to the tubular housing. 16 012964

25. An IV cathéter introducer comprising a tubular housing; a needle holdorassembly having a tubular body slidably engaged inslde the housing; a retractionmechanism seated in an annular space between the housing and the needle holder ' assembly; a plunger assembly having a plunger tube releasably engaged with thetubular body inside the housing; and a cathéter attached by frictional engagement to thetubular housing; wherein the plunger tube comprises a vented end that is opposite the tubular body.

26. The IV cathéter introducer of claim 25 wherein the vented end comprisesa plastic end cap.

27. The IV cathéter introducer of claim 26 wherein the plastic end cap iscolored.

28. The IV cathéter introducer of claim 25 wherein the vented end comprisesan end cap having a vent hole and irregular surface features surrounding the vent hole. 15

29. The IV cathéter introducer of claim 25 wherein the vented end comprisesan end cap having an annular skirt that frictionally engages the plunger tube.

30. The IV cathéter introducer of claim 25 wherein the vented end comprisesa glued end cap.

31. The IV cathéter introducer of claim 25 wherein the vented end comprises a sonically welded end cap.

32. The IV cathéter introducer of claim 25 wherein the vented end comprisesan end cap that is dual shot molded onto the plunger tube.

33. The IV cathéter introducer of claim 25 wherein the retraction mechanism isa spring. 17 012964

34. The IV cathéter introducer of claim 33 wherein the spring is a compressed spring.

35. The IV cathéter introducer of claim 25 wherein the tubular housing and tubular body are made of clear plastic. 5

36. The IV cathéter introducer of claim 35 wherein the clear plastic comprisespolycarbonate.

37. The IV cathéter introducer of claim 35 wherein the needle holder assemblycomprises a flash chamber with an interior space that is viewable through no more thantwo layers of clear plastic. 10

38. The IV cathéter introducer of claim 25 wherein the needle holder assemblyhas an insert molded needle.

39. The IV cathéter introducer of claim 25 wherein a needle is glued intoneedle holder assembly.

40. The IV cathéter introducer of claim 25 wherein a needle is sonicallywelded into needle holder assembly.

41. The IV cathéter introducer of claim 37 wherein thé needle holder assemblyhas a needle with an end that extends into the flash chamber.

42. The IV cathéter introducer of claim 25 wherein the tubular body has a20 plugged end comprising an inwardiy facing annular recess in the tubular body and a porous plug inserted into frictional engagement with the annular recess. 18 012964

43. The IV cathéter introducer of claim 42 wherein the annular recess in thetubular body is adjacent to an outwardly tapered interior wall section of the tubular body.

44. The IV cathéter introducer of claim 25 wherein the tubular houslngcomprises an open end and a plurality of laterally extending wings adjacent to the openend.

45. The IV cathéter introducer of claim 25 wherein the cathéter furthercomprises a cannula depending from a hub attachable to the tubular housing.

46. An IV cathéter introducer comprising a needle holder assembly and aplunger assembly coaxially aligned and slidably engaged inside a tubular housing, acathéter releasably attached to the tubular housing, and a retraction mechanism biasingthe needle holder assembly toward the plunger assembly, wherein: the needle holder assembly comprises an elongated tubular body having a firstend supporting a hollow needle with a beveled end, a second end containing africtionally engaged porous plug, a flash chamber disposed between the first andsecond ends and in fluid communication with the hollow needle, and an outside wallhaving an annular recess disposed near the second end; the plunger assembly comprises an elongated plunger tube having an open endthat is slidably engaged over the second end of the tubular body of the needle holderassembly, a vented end opposite the open end, and engagement structure projectingradially inward near the opén end; the engagement structure being biased into engagement with the annular recessof the needle holder assembly with a force sufficient to prevent the needle holderassembly from being moved toward the plunger assembly by the retraction mechanism.

47. The IV cathéter introducer of claim 46 wherein the tubular body furthercomprises a relief structure into which the engagement structure can be moved bymanually overpressuring the biasing force of the engagement structure to disengage theengagement structure from the annular recess.

48. The IV cathéter introducer of claim 46 wherein the engagement structureis an annular boss. 19 012964

49. The IV cathéter introducer of claim 46 wherein the plunger tube comprisesa retraction cavity sufficiently large to receive at least a portion of the needle holderassembly therein during retraction of the needle to a position where the beveled end isinside the tubular housing. 3 '

50. The IV cathéter introducer of claim 46 wherein the vented end of theplunger tube comprises a frictionally engaged vent cap.

51. · The IV cathéter introducer of claim 50 wherein the vent cap comprises a vent hole and surface relief structures surrounding the vent hole. 10

52. The IV cathéter introducer of claim 46 wherein the vented end comprisesa giued end cap.

53. The IV cathéter introducer of claim 46 wherein the vented end comprisesa sonically welded end cap.

54. The IV cathéter introducer of claim 46 wherein the vented end comprisesan end cap that is dual shot molded onto the plunger tube. 15

55. The IV cathéter introducer of claim 46 wherein the tubular housing and thetubular body are made of clear plastic.

56. The IV cathéter introducer of claim 46 wherein the retraction mechanism isa spring.

57. The IV cathéter introducer of claim 56 wherein the spring is a compressed spring.

58. The IV cathéter introducer of claim 46 wherein the cathéter furthercomprises a cannula through which the hollow needle extends. 20 012964

59. An IV cathéter introducer comprising a tubular housing; a needle holderassembly having a tubular body slidably engaged inside the housing; a rétractionmechanism seated in an annular space between the housing and the needle holderassembly; a plunger assembly having a plunger tube releasably engaged with thetubular body inside the housing; and a cathéter attached by frictional engagement to thetubular housing; wherein the tubular housing comprises an open end and a plurality of laterally extending .wings adjacent to the open end.

60. An IV cathéter introducer comprising a tubular housing; a needle holderassembly having a tubular body slidably engaged inside the housing; a retractionmechanism seated in an annular space between the housing and the needle holderassembly; a plunger assembly having a plunger tube releasably engaged with thetubular body inside the housing; and a cathéter attached by frictional engagement to thetubular housing; wherein the needle holder assembly comprises a flash chamber with an interior spacethat is viewable through no more than two layers of clear plastic.

61. An IV cathéter introducer comprising: a clear plastic tubular housing having a wide end, a narrow end, a stepped insidediameter between the wide and narrow ends, and laterally extending wings adjacent thewide end; a needle holder assembly seated inside the housing, comprising a hollow needlewith a beveled end, a needle support member holding the needle in coaxial alignmentwith the housing, a clear plastic flash chamber in fluid communication with the hollowneedle, a porous plug sealing an end of the flash chamber opposite the hollow needle,and an annular recess facing radially outward near the sealed end of the flash chamber; a plunger assembly further comprising a clear plastic plunger tube with an openend insertable into the housing around a portion of the needle holder assembly, aretraction cavity sufficiently large to accommodate withdrawal of the beveled end of theneedle into the housing upon retraction, a first structure projecting radially outward toengage the housing, and a second structure projecting radially inward to engage theannular recess; and a vented end cap sealing the plunger tube opposite the open end; 21 012964 a rétraction mechanism compressée! inside the housing around the needle support assembly and biasing the needle support assembly toward the retraction cavity of the plunger tube; and5 a cathéter frictionaliy engaging the narrow end of the housing and furthercomprising a cannula coaxially aligned with and slidably disposed over the hollowneedle; wherein the second structure engages the annular recess to prevent the needle support assembly from moving into the retraction cavity under the bias of the retractionic mechanism and any additional force exerted upwardly on the needle during insertion ofthe cannula into. a patient,

62. A method for assembling an IV cathéter introducer comprising the stepsof: providing a tubular housing with a wide end, a narrow end and a stepped inside wall; providing a needle support assembly comprising a tubular body holding a hollowneedle in coaxial alignment with and in fluid communication with a substantiallycylindrical flash chamber, the flash chamber being plugged at an end opposite theneedle with a porous plug, the tubular body also having a spring guide section and anoutwardly facing annular recess near the plugged end; providing a coiled retraction spring slidably engageable with the spring guidesection of the tubular body; providing a plunger assembly comprising a plunger tube having an open end anda vented end, the plunger tube having an outwardly projecting structure and an inwardlyprojecting structure near the open end; 25 providing a cathéter comprising a cannula and a tubular hub; attaching the tubular IV hub to the narrow end of the housing; inserting the coiled retraction spring into the wide end of the housing in coaxial alignment with the housing; inserting the needle support assembly into the wide end of the housing in coaxial 30 alignment with the housing, causing the needle to slide downwardly through the retraction spring and the cannula until the tubular body is seated inside the housing and the retraction spring is disposed around the spring guide; 22 012964 inserting the plunger tube into the wide end of the housing in coaxial alignaientwith the housing and with the needle support assembly, and causing the open end ofthe plunger tube to override the plugged end of the needle holder assembly üntil theoutwardly projecting structure engages the stepped inside wall of the housing and theinwardly projecting structure engages the annular recess, thereby compressing therétraction spring and maintaining the retraction spring in its compressed State by theengagement between the inwardly projecting structure and the annular recess.

63. The method of daim 62 wherein the retraction spring is placed over theneedle support assembly before the needle support assembly is inserted into the wideend of the housing.

64. The method of claim 62 wherein the plunger tube is engaged with theneedle support assembly before the needle support assembly is inserted into the wideend of the housing.

65. The method of claim 62 wherein the needle support assembly is firstprovided without a needle, and the needle is later glued into the needle supportassembly following insertion of the needle support assembly into the housing.

66. The method of claim 62 wherein the needle support' assembly is firstprovided without a needle, and the needle is later sonically welded into the needlesupport assembly following insertion of the needle support assembly into the housing. 23