KR20050085207A - Iv catheter introducer with retractable needle - Google Patents

Abstract

An IV catheter introducer having a retractable needle holder and a tubular plunger that are held by a detent structure in a preferred positional relationship prior to and during insertion of the catheter. Following insertion, the plunger is pushed past the detent structure, permitting a compressed spring to force the needle holder upwardly into the plunger. A vented end cap in the plunger permits rapid venting of air displaced during retraction of the needle holder. The needle holder includes a flash chamber that is easily viewable through a clear plastic housing. Wings are provided on the housing to facilitate one-handed operation of the device. A method for assembling the subject catheter introducer is also disclosed.

Description

IV catheter introducer with retractable needle

The present invention relates to a medical device used for inserting a catheter into the body of a patient, in particular for intravenous delivery of fluid. More specifically, the present invention is a catheter introducer having a shrink needle that prevents reuse and avoids wounds caused by needle puncture by medical personnel and others.

Catheter insertion devices are well known. When the catheter is inserted into the patient for intravenous delivery of body fluids, the disposable needle penetrating the catheter is used to stab blood vessels to allow entry of the catheter. The needle is then retracted with the catheter in place to be capped for connection to an IV bag or bottle or for later use.

Recently, due to the prevalence of pathogenic bacteria caused by blood, such as HIV and hepatitis, catheter inserters that prevent accidental needle puncture by medical staff and other employees handling garbage, laundry or other waste, including used needles The need has increased. As a result, new products have been devised incorporating special needle covers or devices for shrinking the needle after use. Such devices are described, for example, in US Pat. No. 4,747,831; 4,828,548; 5,129,884; 5,501,675; 5,817,058 and 5,959,220 and the like. Many prior art devices include numerous complex parts that substantially increase manufacturing costs and impair the user's ability to sense when the needle is properly inserted into the patient. Other devices require two-handed operation or are subject to needle shrinkage too quickly while transporting, storing and manipulating.

The apparatus of the present invention is described and described in more detail with reference to the drawings in the accompanying drawings.

1 is a simplified perspective view of an IV catheter introducer of the present invention with a catheter needle ready for use.

2 is an enlarged cross sectional view along line 2-2 of FIG.

Figure 3 is the same view as Figure 2, but showing a state in which the needle contracted after use.

FIG. 4 is an enlarged detail view according to FIG. 2, showing a detent structure supporting the front opening of the plunger tube disposed in a preferred position for the needle holder capable of shrinking before contraction; FIG.

5 is an enlarged plan view of the vented plunger end cap.

6 is a cross sectional view along line 6-6 of FIG. 5;

Like reference numerals are used to describe like parts in all figures of the drawings.

Thus, an IV catheter introducer is manufactured that is economical, safely manufactured at high speed, can be operated with one hand without shrinking the needle too quickly, and completely protects the user from accidental puncture and exposure to pathogenic bacteria by blood. need. These and other effects are provided by the present invention described below.

Even those that include a retractable needle are disclosed, disposable IV catheter inserter which offers significant benefits over prior art devices. Major structural improvements include a stable detent structure that supports the needle holder and plunger in the proper positional arrangement after insertion of the catheter and before needle retraction; A plunger end cap for venting air discharged inside the plunger bore while the needle is retracted; And a transparent viewing area that allows a user to more easily view the flash chamber of the needle holder through the transparent plastic housing. Another improved feature is a cylindrical wing that facilitates one-handed operation and prevents rotation when the catheter inserter is placed on face, and a tapered needle holder opening to allow easy insertion of the flash chamber plug during manufacture (needle holder opening), and a needle holder configuration that prevents blunt needle ends from blocking during manufacture and makes the flow of blood into the flash chamber more visible.

The IV catheter introducer of the present invention, which has few parts, can be manufactured stably at high speeds, and significantly reduces the tendency of the needle to shrink too quickly during storage and manipulation, can be easily used with one hand, for medical personnel and other assistants. The numbers can be protected from the possibility of infection as a result of accidental needle puncture and blood-borne pathogens. In addition, the use of the present invention provides significant economic benefits to health care providers and insurers through reduced testing and subsequent costs.

1 to 2, the IV catheter introducer 10 includes a tubular plastic housing 12, a needle holder assembly 14, a retraction spring 16. ), A plunger assembly (18) and an IV catheter (20, IV catheter). The plastic housing 12 has a narrower inner diameter 22 between the opening end 24 and the reduced diameter tip 26, except for a short distance below the annular ring 102 that protrudes inwardly as will be described below. internal bore). The plastic housing 12 is preferably injection molded from a substantially transparent polymeric resin, such as polycarbonate, which is readily visible through the side wall 28. Since the outer diameter of the housing 12 follows the inner diameter 22, which is generally tapered and narrowed, the sidewall 28 forms a wing 30 which extends horizontally by itself, where the user's finger can be placed in a coarse position. A substantially constant thickness except where it is flared outwardly to provide a series of annular ridges 31 spaced in the longitudinal direction near the tip 26 to create a textured gripping area. It will be provided.

The needle holder assembly 14 includes a tapered, elongated tubular body 32, a needle 34, and a porous plug 36 that are resiliently installed in a lower portion of the housing 12. It is desirable to. The body 32 of the needle holder assembly 14 is preferably injection molded from a substantially transparent polymer resin, such as polycarbonate, each of which has a flash chamber 42, each having a gradually smaller diameter, And a tapered sidewall of substantially constant thickness, further defining a spring guide section 44 and a needle support 46. The tubular body 32 of the needle holder assembly 14 is preferably formed to allow the needle holder assembly 14 to be inserted and slidably engaged with the housing 12 during assembly, which will be described in detail below. . The upper end of the tubular body 32 is adapted to releasably engage the lower end 56 of the plunger assembly 18, described below in connection with FIG. 4. As shown in FIG. 2, the contraction spring 16 is enclosed in an annular space 90 between the housing 12 and the spring guide portion 44 of the tubular body 32 and of the tubular body 32. The compression is maintained between the shoulder 92 facing downward and the shoulder 94 facing upward of the housing 12. This embodiment uses a compression spring where the retracting force acts by inflation, but other similar effective means such as tension springs can also be used to retract the needle.

Needle 34 is hollow and has a beveled end 48 that is inserted into a patient's blood vessel in use and a blunt end 50 that extends to a flash chamber 42. The longitudinally extending bore provides fluid connection through the needle 34 between the beveled end 48 and the blunt end 50. Needle 34 is preferably molded by inserting into needle support 46 of tubular body 32, but may be glued into body 32 if desired, or may be sonically welded. If the needle 34 must be inserted after molding the needle support 46, a tapered needle insertion opening 47 is preferably provided at the lower end of the needle support 46. By using the needle 34 long enough to extend into the flash chamber 42, the bore of the needle 34 is not blocked during insertion molding. In addition, a small amount of blood flows up through the needle 34 into the flash chamber 42 each time the needle 34 is injected into a patient's blood vessel, making the blunt end 50 visible within the flash chamber 42. This allows the user to see the blood as soon as the blood enters the flash chamber and the user can confirm that the needle 34 is properly positioned in the vessel.

On top of the flash chamber 42 of the needle holder assembly 14, the end 52 of the tubular body 32 is frictionally plugged into the wall of the annular recess 55 in the body 32. It is blocked by a porous plug. Insertion of the porous plug 36 into the tubular body 32 is preferably facilitated by a tapered inner wall 54 adjacent the end 52. The porous plug 36 allows air to be expelled from the needle 34 and the flash chamber 42 by blood rise through the needle 34 after being inserted into the blood vessel, but such a small amount of blood is transferred to the flash chamber 42. It is preferably made of a suitable porous material that prevents the exit from. A significant effect of the IV catheter inserter 10 disclosed herein is that the flush chamber 42 is transparent only of two layers of the transparent wall of the tubular body 32 surrounding the flash chamber 42 and the transparent wall of the housing 12. It can be seen through clear plastic. In many of the devices disclosed in the prior art, the user must stare at the flash chamber through three or more plastic layers, making it more difficult to observe when blood begins to enter the chamber.

The plunger assembly 18 protrudes outwardly in the longitudinal direction from the lower end 56 adjacent the end 52 of the tubular body 32 of the needle holder assembly 14 and the open end 24 of the housing 12. It is preferred to include a polymeric plunger tube 40 having a substantially cylindrical sidewall with an end 58. The plunger tube 40 is particularly preferably insert molded from a polymeric resin, preferably from a substantially transparent polymer such as polycarbonate. The lower end 56 of the plunger assembly 18 is releasably coupled to the tubular body 32 of the needle holder assembly 14 to form the detent structure of the present invention, which will be described in detail below with respect to FIG. 4. Cooperate with the needle holder assembly 14. The upper end 58 of the plunger tube 40 has an annular recess 62 tapered to the face 64 for receiving and frictionally engaging the end cap 66 described and described further with respect to FIGS. 5 and 6. It is preferred to include a small, radially extending annular flange 60 enclosing it. With the IV catheter inserter 10 ready for use, the upper end 58 of the plunger assembly 18 may be mounted on the wing 30 or housing 12 so that the user's fingers facilitate one-handed operation. While grasping the annular ridges 31, it is desirable to extend about 1.5 to 3 inches from the housing 12 to allow the upper end 58 to rest comfortably relative to the palm. Pulling the housing back with a finger will be discussed below in connection with FIG. 3, causing the needle holder assembly 14 to contract.

Referring to FIGS. 5 and 6, the end cap 66 is designed to help users easily distinguish among polymeric catheter inserters 10 with needles of different sizes, most preferably. It is preferred to be molded from a resin colored in the selected color to correspond to the gauge of the needle 34 shown in FIG. The end cap 66 is a substantially continuous engagement with an annular skirt 70 tapering inwardly and extending in length to provide contact frictional engagement with the annular recess of the plunger tube 40 described above. It is preferred to further include an end wall 68 which is regular and circular. It should be understood that there are many ways to couple the end cap 66 to the upper end 58 of the plunger tube 40. End cap 66 may be joined by glue, snap-on, sonically welded, dual shot molded, or other similar effective means. Double molding refers to a molding process that allows different materials or materials of different colors to be molded at the same time. A vent hole 72 is preferably disposed centrally in the end wall 68 and is face embossed, such as a plurality of molded ribs 74 extending across the face 68 and extending outwardly. It is desirable to be surrounded by surface relief features. While the IV catheter inserter 10 is in operation, even when a portion of the hand rests on the end cap 66, the ribs 74 may be of sufficient number, space and height so that the vent 72 is not blocked by the user's hand. Is preferably. When the needle holder assembly 14 is retracted into the plunger tube 40 after insertion of the catheter, the vent 72 is preferably large enough to quickly vent a certain amount of air exiting the retraction cavity 76. Do.

Referring back to FIGS. 1-2, the IV catheter 20 includes a flexible rubber or plastic cannula 78, a cannula, and a needle passage 82 and an opening 88 receiving the tip 26 of the housing 12. And a hub 80 having a tubular portion 84 having an annular flange 86 defining an opening 88 having a diameter that is frictionally engaged. At the end of the cannula 78 there is an inwardly tapered end 81 that provides an interference fit near the inclined end 48 of the needle 34. While attaching the hub 80 to the tip 26, the needle 34 passes through the elastic cannula 78 and the inwardly tapered end 81, with the inclined end 48 tapered inwardly. (81) Inserted slightly extended above. The inner diameter of the cannula 78 is preferably slightly larger than the outer diameter of the needle 34 to allow for easy shrinkage of the needle 34 through the cannula 78 after insertion. In addition, the hub 80 is preferably adapted for easy connection to traditional IV tubing connections after shrinkage of the needle 34 and removal of the tip 26 from the tubular 84 of the hub 80. Do.

Referring to FIG. 2, the IV catheter inserter 10 of the present invention is preferably assembled by dropping the contraction spring 16 through the opening 22 into the housing 12. The contraction spring 16, a coil spring deflected against compression, is an annular shoulder slanted inside the housing 12 which is supported in a substantially vertical alignment by the section 33 of the sidewall 28. It is preferable to have a diameter portion for seating the spring just above 94. The prefabricated needle holder assembly 14 is then inclined at the inclined end of the needle 34 until the inclined annular shoulder 96 of the tubular body 32 abuts against the shoulder 94 of the housing 12. 48 is inserted downward through the opening end 22 of the housing 12, with the contraction spring 16 passing downward through the tip 26 of the housing 12. Alternatively, the spring 16 may be disposed above the needle holder assembly 14 prior to insertion of the needle holder assembly 14 into the housing 12. Also, if necessary, after the needle holder assembly 14 is inserted into the housing 12, the needle 34 may be adhesively or sonically welded to the needle holder assembly 14. The inclined annular shoulder 92 of the tubular body 32 is preferably not in contact with the inclined annular shoulder 98 to allow proper shoulder seating of the shoulder 96 relative to the shoulder 94. Will not.

2 and 4, the lower end 56 of the prefabricated plunger assembly 18 is next led through the opening 22 into the housing 12. The plunger tube 40 moves downward into the housing 12 such that the nose 104 of the plunger tube 40 arrives over the end 52 of the tubular body 32 of the needle holder assembly 14. It slides. When the nose portion 104 reaches the end 52, the annular projection 100, boss extending radially on the plunger tube 40, annular ring 102 protruding inwardly of the housing 12. Still disposed on top, the inner diameter of the plunger tube 40 in the nose portion 104 slides with the portion of the tubular body 32 where the lower end 56 of the plunger tube 40 is adjacent the end 52. Larger than the outer diameter of the end 52 to allow for possible engagement. As the plunger assembly 18 is further inserted into the housing 12, the annular protrusion 100 engages and covers the annular ring 102. Then, once the plunger tube assembly 18 and the combined needle holder assembly 14 are installed in the housing with the needles extended for use, the annular ring 102 is attached to the plunger tube assembly 18 and the combined needle holder. Suppresses the backward motion of the assembly 14. If there is an attempt to retract the plunger tube assembly 18 from the housing 12, the shoulder of the annular protrusion 100 will contact the shoulder of the annular ring 102 and prevent retraction if no force is applied. . However, it should be understood that the annular ring 102 is preferably small enough to account for the retraction of the molding tool during the manufacturing process. Referring to FIG. 4, which is a detailed view taken from FIG. 2, the plunger tube 40 is sized and arranged cooperatively with an annular projection 106, inwardly directed on the inner surface of the lower end 56. The slide continues downwards over the tubular body 32 of the needle holder assembly until it arrives and snaps into engagement with the outwardly directed recess 108 in the tubular body 32. 2 and 4, the shape and dimensions of the annular protrusion 106 and the annular recess 108 allow the protrusion 106 to radially deflect inwardly into the annular recess 108.

It should be understood that the protrusion 106 on the interior of the plunger tube 40 is not required to extend in the circumferential direction with the annular recess 108 of the tubular body 32. Thus, for example, the protrusion 106 may instead include separate, inwardly extending bumps biased in engagement with the recess 108 and arranged at predetermined intervals in the circumferential direction. However, the recess 108 preferably extends completely around the tubular body such that a slidable engagement between the plunger tube 40 and the tubular body 32 does not require a specific rotational alignment between the two parts. . The shape and dimensions of the protrusion 106 and the recess 108 are required to slidably separate the protrusion 106 from the recess 108 by keeping the plunger tube 40 far below the housing 12. The applied force is greater than the biasing force applied against the needle holder assembly 14 by the compressed contraction spring 16 and by the additional force applied upwardly on the needle 34 during the catheter insertion process. Such is preferable. The IV catheter 20 may be assembled to the tip 26 of the housing 12 prior to insertion of the needle holder assembly 14 and the plunger assembly 18 into the housing 12. Alternatively, the plunger assembly 18 and the needle holder assembly 14 may also be assembled to each other prior to insertion into the housing 12 (sometimes referred to as a needle support assembly). When the protrusions 106 and the recesses 108 are coupled to each other, the frictional engagement between the protrusions 106 and the recesses 108 is preferably such that the needle holder assembly 14 and the plunger assembly 18 have a housing ( 12) is sufficient to allow insertion together.

While holding the annular ridges 31 of the housing 12 with the thumb and fingers, the inclined needle end 48 and part of the cannula 78 are preferably inserted into the patient's blood vessel. After inserting the catheter into the patient, the needle holder assembly 14 is retracted by plucking the wing 30 or the annular ridge 31 with human fingers or thumb and fingers, after which the plunger tube 40 is closed. A palm or heel of the hand is used against the end cap 66 to put it further down in the housing 12. When this happens, as can be seen in FIG. 4, the frictional engagement between the protrusion 106 and the recess 108 is overpressured and the protrusion 106 rises on the face 112 of the tubular body 32. Let's go. Continued downward movement of the plunger tube 40 relative to the tubular body 32, which is seated relative to the housing 12, causes the protrusion 106 to fall off the inclined shoulder 114 of the tubular body 32. . When this happens, there is no significant friction force applied against the compressed shrink spring 16, and the spring 16 expands rapidly, causing the needle holder assembly 14 to enter the retraction cavity 76. At the needle 34 at the position where the inclined end 48 is retracted into the housing 12.

Referring to FIG. 3, the shrink spring 16 is fully inflated and the upper end 52 of the needle holder assembly 14 is at least partially retracted into the shrink cavity 76. As the needle holder assembly 14 is moved upwards in the retraction cavity in response to the retraction spring 16, the previous air present in the retraction cavity 76 of the plunger tube 40 leaks through the vent 72. I'm going. The upper end 52 of the needle holder assembly 14 moves upwards sufficiently within the shrinking cavity 76 where the inclined end 48 of the needle 34 is retracted into the housing 12. When the needle 34 is in the position shown in FIG. 3, the tip 26 of the housing 12 can be safely separated from the IV hub 80.

The improved IV catheter introducer of the present invention is more suitable for automated fabrication and assembly. Apart from the catheter, a needle and spring, only one housing, a retractable needle holder and a capped and ventilated plunger tube are required. Although the housing 12 can be made vertical in shape with a straight inner wall, it is preferably made in a stepped shape tapered inward from top to bottom, except for the lower shoulder of the annular ring 102. This taper facilitates the removal of the core mandrel used in the molding process. Although not shown in the figures, the inclined end 48 of the needle 34 is protected by a tubular cover that slides upward over the outside of the cannula 78 to prevent the needle from being damaged, during the manufacturing process, transportation and storage. It should be understood that it is desirable to be.

An important aspect of the subject IV catheter inserter is the fact that the operator can conveniently manipulate the structure of the inserter to retract with one hand. Since the plunger tube preferably extends about 1.5 to 3 inches or more where the wings of the housing are located, one hand operation is possible. This allows the force to be applied against the plunger tube by the flesh portion of the palm while using the fingers behind the wings or annular ridges of the housing to suppress the force and start the contraction smoothly. The other hand is free to hold the catheter's hub. The appropriate time to free the hub from the insertion device and attach the IV tube to the hub is under full control of the operator. In one exercise, an IV tube or other device to be connected to the patient is then connected, while the catheter's hub can be separated from the insertion device, which can then be safely removed. Since the needle is safely retracted before the catheter assembly is detached from the housing, the catheter inserter can be safely placed on its side regardless of the bed or tray. When the fingers pull the wing or annular ridges of the housing to cause contraction, the operator can also hear the needle safely contract and use his hand for use in making the necessary IV connections before the patient loses fluid. The device can be disconnected immediately and placed safely next to it for freedom.

The IV catheter introducer of the present invention does not have to suppress the force exerted by the needle on the shrinkage component as much as conventional syringes required to stab and puncture the burrs used in glass bottles. As a result, shrinkable parts are needed to be able to suppress the forces encountered during normal clinical use without shrinkage. With the device disclosed herein, dimensional tolerances and differential thermal expansion rates are less important than devices provided by face to face contact only between faces where frictional engagement is smooth.

Even when rough manipulation and severely varying temperature and humidity are involved during transport or storage prior to use, the IV catheter introducer of the present invention is less prone to shrinking the needle too sooner than prior art devices. The present invention is simple and has a contraction spring that is simpler and safer to operate compared to the streamlined shape and other previously used others. Since the device does not have external latches that require it to position the device in a particular direction, it can be operated with one hand in a rotational position where the wings are accessible. In addition, the wings prevent the catheter introducer from rotating when placed on an inclined surface. With the device supported in the hand, the retraction force is applied linearly along the main longitudinal axis. Very short strokes are sufficient to cause contractions. Because the operator can easily see the retracted part in the housing and the retraction produces a subtle noise, the successful retraction can be seen visually and audibly.

Other alternatives and modifications of the preferred embodiments described above will be apparent to those skilled in the art upon reading this disclosure, and the scope of the invention disclosed herein is intended to be limited by the broadest interpretation of the appended claims to which the inventor is entitled by law.

Claims (66)

Tubular housing; A needle holder assembly having a tubular body slidably coupled within the housing; A retraction device seated in an annular space between the housing and the needle holder assembly; A plunger assembly having a plunger tube releasably coupled with said tubular body inside said housing; And a catheter attached by frictional engagement to the tubular housing, wherein the catheter inserter comprises: The tubular body includes an outwardly facing recessed portion adjacent the plunger tube; The plunger tube includes an annular protrusion extending outwardly adjacent the tubular body; Wherein said annular recess and said annular projection are deflected in a releasable engagement. The IV catheter introducer of claim 1, wherein the retraction device is a spring. The IV catheter introducer of claim 2, wherein the spring is a compression spring. The IV catheter inserter of claim 1, wherein the tubular housing and the tubular body are made of transparent plastic. The IV catheter inserter of claim 4, wherein the transparent plastic comprises polycarbonate. The IV catheter introducer of claim 1, wherein the plunger tube has a vented end that is remote from the tubular body. 7. The catheter introducer of claim 6, wherein said vented end comprises a plastic end cap. 8. The catheter introducer of claim 7, wherein said plastic end cap is colored. 7. The catheter introducer of claim 6, wherein said vented end includes an end cap having vents and irregularly shaped features surrounding said vents. 7. The catheter introducer of claim 6, wherein said vented end comprises an end cap having an annular skirt that frictionally engages said plunger tube. 7. The catheter introducer of claim 6, wherein said vented end includes an end cap to which it is glued. 7. The catheter introducer of claim 6, wherein said vented end comprises an end cap that is sonically welded. 7. The catheter introducer of claim 6, wherein said vented end comprises an end cap double molded into said plunger tube. 5. The catheter introducer of claim 4, wherein said needle holder assembly comprises a flash chamber having an interior space viewable through only two layers of transparent plastic. The IV catheter inserter of claim 1, wherein the needle holder assembly has a needle that is insert molded. The IV catheter introducer of claim 1, wherein a needle is attached to the needle holder assembly. The IV catheter introducer of claim 1, wherein a needle is acoustically welded to the needle holder assembly. 15. The IV catheter introducer of claim 14, wherein said needle holder assembly has a needle having an end extending to said flash chamber. The IV catheter insertion of claim 1, wherein the tubular body has a plugged end comprising an annular recess inwardly directed to the tubular body and a porous plug that is frictionally inserted into the annular recess. group. 20. The IV catheter introducer of claim 19, wherein said annular recess in said tubular body is adjacent to an outwardly tapered inner wall portion of said tubular body. The tubular body of claim 1 further comprising a reduced diameter section longitudinally spaced from the annular recess, the plunger tube sliding the annular protrusion from the annular recess. An IV catheter introducer, detachable from the tubular body by applying a force to the plunger tube at a position opposite the reduced diameter along the tubular body sufficient to cause the plunger tube. 22. The IV catheter introducer of claim 21, wherein said needle holder assembly is forced into said plunger tube by said retracting device when said annular protrusion is opposite said reduced diameter. The IV catheter introducer of claim 1, wherein the tubular housing comprises a plurality of wings adjacent and extending laterally to an open end and to the open end. The IV catheter introducer of claim 1, wherein the catheter comprises a cannula that hangs from a hub attachable to the tubular housing. Tubular housing; A needle holder assembly having a tubular body slidably coupled within the housing; A retraction device seated in an annular space between the housing and the needle holder assembly; A plunger assembly having a plunger tube releasably coupled with said tubular body inside said housing; And a catheter attached by frictional engagement to the tubular housing, the catheter inserter comprising: And the plunger tube includes a vented end opposite the tubular body. 27. The IV catheter introducer of claim 25, wherein said vented end comprises a plastic end cap. 27. The catheter introducer of claim 26, wherein said plastic end cap is colored. 27. The IV catheter introducer of claim 25, wherein said vented end comprises an end cap having vents and irregular face features surrounding said vents. 27. The IV catheter introducer of claim 25, wherein said vented end comprises an end cap having an annular skirt that frictionally engages said plunger tube. 27. The IV catheter introducer of claim 25, wherein said vented end comprises an end cap to which it is glued. 27. The IV catheter introducer of claim 25, wherein said vented end comprises an end cap that is sonically welded. 27. The IV catheter introducer of claim 25, wherein said vented end comprises an end cap double molded in said plunger tube. The IV catheter introducer of claim 25, wherein the retraction device is a spring. The catheter introducer of claim 33, wherein the spring is a compression spring. 27. The IV catheter introducer of claim 25, wherein said tubular housing and said tubular body are made of transparent plastic. 36. The IV catheter introducer of claim 35, wherein said transparent plastic comprises polycarbonate. 36. The IV catheter introducer of claim 35, wherein said needle holder assembly comprises a flash chamber having an interior space viewable through only two layers of transparent plastic. The IV catheter inserter of claim 25, wherein the needle holder assembly has a needle that is insert molded. 27. The IV catheter introducer of claim 25, wherein a needle is attached to said needle holder assembly. The IV catheter introducer of claim 25, wherein the needle is sonically welded to the needle holder assembly. 38. The IV catheter introducer of claim 37, wherein said needle holder assembly has a needle having an end extending to said flash chamber. The catheter insertion of claim 25, wherein the tubular body has a plugged end comprising an annular recess inwardly directed to the tubular body and a porous plug that is frictionally inserted into the annular recess. group. 43. The IV catheter introducer of claim 42, wherein said annular recess in said tubular body is adjacent to an outwardly tapered inner wall portion of said tubular body. 27. The IV catheter introducer of claim 25, wherein said tubular housing comprises an opening end and a plurality of wings adjacent and extending laterally to said opening end. 27. The catheter introducer of claim 25, wherein said catheter comprises a cannula hanging from a hub attachable to said tubular housing. A plunger assembly coaxially arranged and slidably coupled within the needle holder assembly and the tubular housing, a catheter releasably attached to the tubular housing, and a retraction device for biasing the needle holder assembly toward the plunger assembly Including an IV catheter inserter, The needle holder assembly is provided with a first end for supporting the hollow needle with the inclined end, a second end including the frictionally bonded porous plug, disposed between the first and second ends and in fluid communication with the hollow needle. An elongated tubular body having a flash chamber and an outer wall having an annular recess disposed near the second end; The plunger assembly has an opening end slidably coupled over the second end of the tubular body of the needle holder assembly, a ventilation end opposite the opening end, and a radially inwardly projecting engagement near the opening end. An elongated plunger tube having a structure; The engagement structure biases the IV catheter insertion into engagement with the annular recess of the needle holder assembly with sufficient force to prevent the needle holder assembly from moving towards the plunge assembly by the retraction device. group. 47. The relief structure of claim 46, wherein the tubular body has a relief structure in which the coupling structure can be moved by manually overpressing the biasing force of the coupling structure to separate the coupling structure from the annular recess. Further comprising, an IV catheter introducer. 47. The catheter introducer of claim 46, wherein said engagement structure is an annular protrusion. 47. The IV catheter insertion of claim 46, wherein the plunger tube comprises a contraction cavity large enough to receive at least a portion of the needle holder assembly while the needle is retracted to a position where the inclined end is inside the tubular housing. group. 47. The catheter introducer of claim 46, wherein said vented end of said plunger tube comprises a vent cap that is frictionally coupled. 51. The catheter introducer of claim 50, wherein said vent cap comprises a vent and a face relief structure surrounding said vent. 47. The catheter introducer of claim 46, wherein said vented end includes an end cap to which it is glued. 47. The catheter introducer of claim 46, wherein said vented end comprises an end cap that is sonically welded. 47. The IV catheter introducer of claim 46, wherein said vented end comprises an end cap double molded in said plunger tube. 47. The catheter introducer of claim 46, wherein said tubular housing and said tubular body are made of transparent plastic. 47. The catheter introducer of claim 46, wherein said retraction device is a spring. 57. The IV catheter introducer of claim 56, wherein said spring is a compression spring. 47. The catheter introducer of claim 46, wherein said catheter comprises a cannula through which said hollow needle extends. Tubular housing; A needle holder assembly having a tubular body slidably coupled within the housing; A retraction device seated in an annular space between the housing and the needle holder assembly; A plunger assembly having a plunger tube releasably coupled with said tubular body inside said housing; And a catheter attached by frictional engagement to the tubular housing, the catheter inserter comprising: And the tubular housing includes an opening end and a plurality of wings adjacent and extending laterally to the opening end. Tubular housing; A needle holder assembly having a tubular body slidably coupled within the housing; A retraction device seated in an annular space between the housing and the needle holder assembly; A plunger assembly having a plunger tube releasably coupled with said tubular body inside said housing; And a catheter attached by frictional engagement to the tubular housing, the catheter inserter comprising: And the needle holder assembly comprises a flash chamber having an interior space visible through only two layers of transparent plastic. A tubular housing of transparent plastic having a wide end, a narrow end, a stepped inner diameter between the wide and narrow ends, and laterally extending wings adjacent the wide end; A hollow needle having an inclined end, a needle support member supporting the needle coaxially arranged in the housing, a transparent plastic flash chamber in fluid communication with the hollow needle, and sealing an end of the flash chamber opposite the hollow needle A needle holder assembly comprising a porous plug and an annular recess facing radially outward near the sealed end of the flash chamber and seated inside the housing; A transparent plastic plunger having an opening end that can be inserted into the housing around some of the needle holder assemblies, a shrinkage cavity large enough to adequately pull the inclined end of the needle into the housing when retracted Sealing a plunger tube opposite the opening end, a first structure radially outwardly projected to engage the housing and a second structure projected radially inwardly to engage the annular recess; A plunger assembly further comprising a vented end cap; A retraction device compressed into the housing around the needle support assembly that biases the needle support assembly toward the retraction cavity of the plunger tube; And A cannula frictionally engaged with said narrow end of said housing and arranged coaxially with said hollow needle and slidably disposed over said hollow needle, The second structure is adapted to prevent the needle support assembly from moving into the contraction cavity under the deflection of the contraction device and the additional force acting upward on the needle during insertion of the cannula to the patient. An IV catheter introducer that engages the groove. Providing a tubular housing having a wide end, a narrow end, and a stepped inner wall; A tubular body supporting a hollow needle substantially coaxially and fluidly connected with the cylindrical flash chamber, said flash chamber being plugged at an end opposite said needle provided with a porous plug, said tubular body Providing a needle support assembly having a spring guide portion and an annular recess facing outward near the plugged end; Providing a coil shrink spring that is slidably engageable with the spring guide portion of the tubular body; Providing a plunger assembly having a plunger tube having an opening end and a venting end, the plunger tube having an outwardly projecting structure and a structure projecting inward near the opening end; Providing a catheter comprising a cannula and a tubular hub; Attaching the tubular IV hub to the narrow end of the housing; Inserting the coil contraction spring within the wide end of the housing to be arranged coaxially with the housing; By inserting the needle support assembly at the wide end of the housing coaxially with the housing, the needle is mounted until the tubular body rests inside the housing and the retracting spring is disposed around the spring guide. Sliding downward through said contraction spring and said cannula; By inserting the plunger tube at the wide end of the housing to be arranged coaxially with the housing and the needle support assembly, and the outwardly projecting structure engages with the stepped inner wall of the housing and protrudes inwardly. The opening end of the plunger tube covers over the plugged end of the needle holder assembly until the structure engages the annular recess, thereby compressing the contraction spring and projecting inwardly; and Maintaining the contraction spring in a compressed state by engagement between the annular recesses. 63. The method of claim 62, wherein the retraction spring is disposed above the needle support assembly before the needle support assembly is inserted into the wide end of the housing. 63. The method of claim 62, wherein the plunger tube is engaged with the needle support assembly before the needle support assembly is inserted into the wide end of the housing. 63. The method of claim 62, wherein the needle support assembly is first provided without a needle, and after insertion of the needle support assembly into the housing, the needle is subsequently attached to the needle support assembly. 63. The method of claim 62, wherein the needle support assembly is first provided without a needle, and the needle is subsequently acoustically welded to the needle support assembly after insertion of the needle support assembly into the housing.