RU2299078C2 - Conductor for introduction of intravenous catheter provided with taking-away needle - Google Patents

Abstract

FIELD: medical facilities.

SUBSTANCE: conductor can be used for introduction of medicinal preparations in patient's body, in particular, for intravenous introduction of fluid. Conductor for introduction of intravenous catheter has tubular case; unit of needle holder provided with tubular case engaged with case for shift; take-away mechanism mounted in ring-shaped space between case and unit of needle holder; plunger unit with plunger pipe introduced into dismountable engagement with tubular case inside casing; and catheter connected to tubular case by means of friction engagement. Tubular case has ring-shaped groove turned outside, which groove is proximal in relation to plunger pipe. Plunger pipe has ring-shaped boss, oriented inside, which boss is proximal in relation to tubular case. Ring-shaped groove and ting-shaped boss are pressed to form dismountable joint. According to other version of manufacture, plunger pipe has end with opening, which has to be opposite to tubular case. According to third version of manufacture, elongated tubular case has first end which fastens hollow needle with slanted end, second end containing porous plug, supported by friction engagement; expanding chamber disposed between first and second ends, which chamber communicates with hollow needle via channel for fluid, and external wall provided with ring-shaped groove, which groove is disposed close to second end. Plunger pipe has open end which is introduced into engagement for shift along second end of tubular casing of unit of needle holder; end with opening to opposite to open end, and engaging structure protruding in radial inside close to open end. Engaging structure is spring-loaded to make engagement with ring-shaped groove of unit of needle holder by force being sufficient to prevent movement of unit of needle holder against plunger unit by take-away mechanism. According to fourth version of manufacture, part of needle mounting goes though take-away mechanism and it protrudes in front of tubular casing. According to fourth mechanism, conductor for introduction of intravenous catheter has transparent plastic tubular casing, unit of needle holder mounted inside casing, plunger unit, take-away mechanism and catheter. Casing has narrow end, wide end, stepwise diameter between wide and narrow ends, and transversely protruding shelves being adjacent to wide end. Unit of needle holder is mounted inside casing and it has hollow needle with slanted end, member of mounting of needle which keeps needle in axial to casing, transparent plastic expansion chamber which communicated with hollow needle along communication channel, porous plug, which plugs expansion chamber at end being opposite to hollow needle, and ring-shaped groove turned in radial outside close to plugged end of expansion chamber. Plunger unit has transparent plastic plunger pipe with open end inserted into casing to embrace part of mounting of unit of needle holder, cavity for taking away, which cavity is big enough to provide removal of slanted end of needle into casing after taking-away; first structure protruding radial outside to make engagement with casing, and second structure protruding radial inside to make engagement with ring-shaped groove; edge cap provided with opening, which cap plugs plunger pipe at side being opposite to open end. Take-away mechanism, pressed inside casing around unit of mounting of unit of needle holder, which mechanism spring-loads unit if mounting of needle against cavity for take-away inside plunger pipe. Catheter, which embraces narrow end of catheter, has dish disposed in axial to hollow needle and is capable of moving freely inside it. Second structure engages with ring-shaped groove to prevent shift of unit of mounting of needle holder in cavity for take-away by press force of take-away mechanism and by any additional force, which effects top of end when dish is introduced in patient's body.

EFFECT: reliability; quick manufacture; lower chance of taking needle away before time at storage and operation; protection of medical personnel against random punctures of needle; reduced chance of getting infected by pathogenic factors transferred by blood.

66 cl, 6 dwg

Description

FIELD OF THE INVENTION

The invention relates to a medical device used to insert a catheter into a patient’s body, in particular for intravenous administration of a liquid. In particular, the invention relates to a guide for insertion of a catheter containing a retractable needle, which prevents reuse and makes it impossible to injure the needle tip of medical personnel and other persons.

Description of the Related Art

Catheter insertion devices are widely known. When a catheter is inserted into a patient for intravenous fluid administration, a removable needle is inserted through the catheter to puncture the vein to allow the catheter to be inserted. Then the needle is removed, leaving the catheter in the working position for connection with the bag or bottle for intravenous infusion or for closing until subsequent use.

In recent years, due to the widespread spread of bloodborne pathogenic factors, such as HIV (HIV) and hepatitis, the need has increased for catheter guides that prevent accidental injuries by the needle point of medical personnel and other workers who work with garbage, linen and other waste containing used needles. As a result, new products have been developed that include special needle covers or mechanisms for removing needles after use. These devices are described, for example, in US patent No. 4747831; 4,828,548; 5129884; 5,501,675; 5817058 and 5989220. Many of the known devices contain numerous complex parts that significantly increase manufacturing costs and damage the user's ability to feel when the needle is correctly inserted into the patient. Other devices require two-handed operation or are prone to premature needle removal during transport, storage and handling.

Therefore, such a guide is required for the introduction of an intravenous catheter, which can be quickly, inexpensively and reliably manufactured, which will not prematurely remove the needle, which can be operated with one hand, and which completely protects the user and other persons from accidental injections and the influence of pathogenic factors transferred with blood. The invention described below provides the following and other advantages.

SUMMARY OF THE INVENTION

A disposable guide for introducing an intravenous catheter is proposed, which provides significant advantages over known devices, even those that include retractable needles. Fundamental structural improvements include a reliable locking structure that keeps the needle holder and plunger precisely aligned in position until the needle is removed after the catheter is inserted; the end cap of the plunger, which releases air displaced from the inner cavity of the plunger when the needle is removed; and a transparent viewing area, which allows the user to more conveniently observe the expansion chamber of the needle holder through a transparent plastic case. Other improvements include shelves on the case, which facilitate one-handed operation and prevent the guidewire from rolling to insert the catheter when laying onto the surface, a hole in the needle holder that is conical in shape so that it is easier to insert the expansion chamber plug during manufacture, and the shape needle holder, which prevents clogging of the blunt end of the needle during manufacture and improves the visibility of blood flow into the expansion chamber.

The guides for introducing the intravenous catheters according to the present invention contain few details, allow reliable and quick manufacture, significantly reduce the likelihood of prematurely removing the needle during storage and handling, are suitable for convenient use with one hand, and will protect medical and other support personnel from accidental injections by the needle and the resulting this risk of infection by blood borne pathogenic factors. The application of the present invention also provides tangible economic benefits to health care providers and policyholders by reducing the volume of trials and additional costs.

Brief Description of the Drawings

The following is a description of the device according to the present invention with reference to the following drawings, in which:

figure 1 is a simplified perspective view of a conductor for introducing an intravenous catheter according to the present invention with a catheter needle, ready for use;

figure 2 is an enlarged view in vertical section along the line 2-2 shown in figure 1;

figure 3 is a view similar to the view in figure 2, but with the needle removed after use;

figure 4 is an enlarged local view taken from figure 2, and depicts a retaining structure that holds the lowered front hole of the plunger tube in a predetermined position relative to the holder of the retractable needle until the retraction;

5 is an enlarged plan view of a plunger end cap provided with an aperture; and

6 is an enlarged view in vertical section along the line 6-6 shown in figure 5.

For the designation of similar parts in all figures of the drawings apply the same position.

Detailed Description of a Preferred Embodiment

As can be seen from FIGS. 1-2, the conductor 10 for introducing an intravenous catheter preferably comprises a tubular plastic case 12, a needle holder assembly 14, a return spring 16, a plunger assembly 18, and an intravenous catheter 20. In the plastic case 12 there is an inner opening 22 that tapers in series from the open end 24 to the tip 26 with a reduced diameter, with the exception of a short section below the inwardly extending annular belt 102, as described below. The plastic case 12 is preferably injection molded from a substantially transparent polymer resin, for example polycarbonate, to allow easy viewing through the wall 28. The outer diameter of the case 12 typically follows the conical narrowing of the inner hole 22, so that the side wall 28 has essentially a constant thickness, except for places where the side wall expands outward and forms transversely protruding shelves 30 and a sequence of annular protrusions 31, longitudinally located closer to the tip 26 for Framing the embossed gripping surface under the user's fingers.

The needle holder assembly 14 is removably mounted in the lower portion of the case 12 and preferably comprises a cone-shaped elongated tubular body 32, a needle 34 and a porous plug 36. The housing 32 of the needle holder assembly 14 is preferably injection molded from a substantially transparent polymer resin, for example polycarbonate , and contains a conical side wall of substantially constant thickness, which further limits the expansion chamber 42, the spring guide portion 44 and the needle attachment portion 46, each of which has successively reduced diameter. The tubular body 32 of the needle holder assembly 14 preferably has a shape that allows the needle holder assembly 14 to be inserted into the shear-engaging housing 12 during assembly, in accordance with the following detailed description. The upper end portion of the tubular body 32 is detachably engaged with the lower end 56 of the plunger assembly 18 in accordance with the description below with reference to FIG. 4. As can be seen from figure 2, the return spring 16 is enclosed in an annular space 90 between the case 12 and the spring-guiding portion 44 of the tubular body 32 and is fixed in a compressed state between the downward-facing shoulder 92 of the tubular body 32 and the upward-facing shoulder 94 of the case 12. Although in the present embodiment the implementation uses a compressed spring, which exerts a return force by expansion, to remove the needle you can also apply other similar effective means, for example, a tension spring.

The needle 34 is hollow and has a tapered end 48 that is inserted into the patient’s vein during use and a blunt end 50 that projects into the expansion chamber 42. A longitudinally extending channel allows fluid to pass through the needle 34 between the tapered end 48 and the blunt end 50. Needle 34 it is preferably poured into the needle attachment portion 46 in the tubular body 32, but may, if necessary, be glued or secured by ultrasonic welding in the housing 32. A conical hole is preferably provided at the lower end of the needle attachment portion 46 47 for inserting a needle, if the needle 34 is to be inserted after forming the needle holding portion 46. When using a needle 34 that is long enough to extend into the expansion chamber 42, the channel of the needle 34 will not become clogged when filling. In addition, since a little blood flows up the needle 34 into the expansion chamber 42 when the needle 34 is inserted into the vein of the patient, ensuring that the blunt end 50 is visible in the expansion chamber 42 allows the user to see the blood as soon as it enters the expansion chamber 42 and make sure that the needle 34 is correctly located in the vein.

On top of the expansion chamber 42 of the needle holder assembly 14, the end 52 of the tubular body 32 is closed by a porous plug 36, which is frictionally engaged by the walls of the circular groove 55 in the housing 32. It is preferable to simplify the insertion of the porous plug 36 into the tubular housing 32 by tapering the inner wall 54 at the end 52. Porous plug 36 is preferably made of any suitable porous material that will allow air to be displaced from the needle 34 and the expansion chamber 42 with blood that rises along the needle 34 after being introduced into the vein, but does not allow at least minimal leakage of the mentioned blood from the expansion chamber 42. An important advantage of the conductor 10 for introducing an intravenous catheter proposed here is that the expansion chamber 42 is visible only through two layers of transparent plastic: the transparent wall of the tubular body 32 around the expansion chamber 42; and the transparent wall of the case 12. In many known devices, the user must look through at least three layers to see the expansion chamber, which greatly complicates the visual determination of the beginning of blood flow into the chamber.

The plunger assembly 18 preferably comprises a polymer plunger tube 40 having a substantially cylindrical side wall with a lower end portion 56 that is proximal to the end 52 of the tubular body 32 of the needle holder assembly 14 and an upper end portion 58 that extends longitudinally outward from the open end 24 of the case 12. The plunger tube 40 is preferably injection molded from a polymer resin, and most preferably, from a substantially transparent polymer, for example polycarbon ata. The lower end portion 56 of the plunger assembly 18 is releasably engaged with the tubular body 32 of the needle holder assembly 14 and interacts with the needle holder assembly 14 to form a locking structure according to the present invention in accordance with the detailed description below with reference to FIG. 4. At the upper end portion 58 of the plunger tube 40, a small annular collar 60 is preferably formed surrounding the conical circular groove 62 in the surface 64, which accommodates and frictionally engages the end cap 66, which is further described with explanations using FIGS. 5 and 6. Ready to use an intravenous catheter guide 10, the upper end 58 of the plunger assembly 18 preferably extends from about 1.5 to about 3 inches from the case 12 so that the upper end 58 can be pressed against Doni, when the user's fingers grip the flange 30 or the annular projections 31 of the case 12, to facilitate one-handed operation. Pulling the case back 12 with your fingers causes the needle holder assembly 14 to be removed in accordance with the description below with reference to FIG. 3.

As can be seen from FIGS. 5 and 6, the end cap 66 is preferably molded from a polymer resin, and in the most preferred embodiment, from a resin that contains a pigment selected in color according to the gauge of the needle 34 shown in FIGS. 1-2, so that users can it is easy to distinguish conductors 10 for introducing intravenous catheters with needles of different sizes. The end cap 66 preferably further comprises a substantially continuous annular end wall 68 connected to a longitudinally extending annular bead 70, which tapers inward to provide the previously mentioned frictional engagement with the circular groove 62 of the plunger tube 40. It should be understood that there are many ways to ensure engagement of the installation of the end cover 66 in the upper end portion 58 of the plunger tube 40. The end cover 66 can be glued, snap spring, weld with ultrasound , double-cast or hook on with any other similar effective means. Two-jet molding is called any molding method that allows parallel molding of different materials or multi-colored materials. The air hole 72 is preferably located in the center of the end wall 68 and is preferably surrounded by structural elements of the surface relief, for example, a plurality of protruding molded ribs 74 that extend along the surface 68. In a preferred embodiment, the number, pitch and height of the ribs 74 are sufficient to ensure that the air hole 72 was not closed by the hand of the user, even when a part of the hand was placed over the end cap 66 when working with the conductor 10 for introducing an intravenous catheter. The air hole 72 is preferably large enough to quickly release the volume of air displaced from the cleaning cavity 76 when the needle holder assembly 14 is removed into the plunger tube 40 after insertion of the catheter.

1-2, the intravenous catheter 20 preferably comprises a flexible rubber or plastic cannula 78 and a sleeve 80 having a needle tube 82 and a tubular section 84 with an annular flange 86 defining an opening 88 of such a diameter that the opening 88 will also accommodate friction hook the tip 26 of the case 12. At the end of the cannula 78 there is a tip 81 which tapers inwardly, which provides an interference fit near the beveled end 48 of the needle 34. When installing the sleeve 80 on the tip 26, the needle 34 is inserted through the flexible cannula 78 and tapering inside the tip 81, with beveled end 48 slightly beyond the inwardly tapered tip 81. The inner diameter of cannula 78 is preferably slightly larger than the outer diameter of the needle 34 to the needle 34 can be easily remove by cannula 78 after insertion. In addition, the sleeve 80 is preferably configured to easily connect to a standard intravenous tube connector after removing the needle 34 and removing the tip 26 from the tubular portion 84 of the sleeve 80.

As shown in FIG. 2, the conductor 10 for introducing an intravenous catheter according to the present invention is preferably assembled by lowering the return spring 16 through the opening 22 into the case 12. The return spring 16, which is a preloaded cylindrical spring, preferably has a diameter with which the spring is only installed at the top of the inclined an annular shoulder 94 inside the case 12, where it is supported essentially in an upright position by a portion 33 of the side wall 28. Then, the finished needle holder assembly 14 is inserted downward through cut the open end 22 of the case 12, while the beveled end 48 of the needle 34 is passed down through the return spring 16 and the tip 26 of the case 12 until the stop of the inclined annular shoulder 96 of the tubular body 32 into the shoulder 94 of the case 12. Alternatively, the spring 16 can be installed on the node 14 the needle holder before inserting the needle holder assembly 14 into the case 12. In addition, if necessary, the needle 34 can be glued or ultrasonically fixed to the needle holder assembly 14 after inserting the needle holder assembly 14 into the case 12. Inclined annular shoulder 92 of the tubular body and 32 preferably will not come into contact with the inclined annular shoulder 98 so as to enable proper support of the shoulder 96 against the shoulder 94.

As shown in FIGS. 2 and 4, then the lower end portion 56 of the finished plunger assembly 18 is inserted into the case 12 through the opening 22. As the plunger tube 40 passes down into the case 12, the leading edge 104 of the plunger tube 40 reaches the end 52 tubular body 32 of the node 14 of the needle holder and moves along it. When the leading edge 104 reaches end 52, the radial annular tide 100 on the plunger tube 40 is still located above the inwardly extending annular belt 102 of the case 12, and the inner diameter of the plunger tube 40 at the leading edge 104 is sufficiently larger than the outer diameter of the end 52 so that the lower end the portion 56 of the plunger tube 40 could be latched to engage in a portion of the tubular body 32 that is adjacent to the end 52. As the plunger assembly 18 is inserted further into the case 12, the annular tide 100 engages in rings oh belt 102 and goes over it. Then, the annular belt 102 does not allow the tubular plunger assembly 18 and the integrated needle holder assembly 14 to move back after they are installed in the case, the needle protruding for use. When trying to remove the tubular plunger assembly 18 from the case 12, the shoulder of the annular tide 100 will catch on the shoulder of the annular belt 102 and will prevent removal until considerable force is applied. However, it should be understood that the annular belt 102 is preferably small enough to allow extraction of the injection tool during manufacturing. As can be seen from FIG. 4, which is a local view taken from FIG. 2, the plunger tube 40 continues to slide down the tubular body 32 of the needle holder assembly until the inwardly directed annular tide 106 on the inner surface of the lower end portion 56 reaches and engages with snap-fit made with connecting dimensions and orientation, the outwardly facing circular groove 108 of the tubular body 32. As shown in FIGS. 2 and 4, the configuration and dimensions of the annular tide 106 and the circular groove 108 cause the tide 106 to shift radially flax inside in a circular groove 108.

It should be understood that the tide 106 on the inner surface of the plunger tube 40 does not have to correspond to the circumferential groove 108 of the tubular body 32 around the entire circumference. Consequently, the tide 106 can, for example, be replaced by a group of individual circumferentially extending protrusions that are meshed with the groove 108. However, in a preferred embodiment, the groove 108 extends around the entire tubular body so that shear engagement between the plunger tube 40 and the tubular body 32 does not require gates specifically for combining two parts. The tide 106 and the groove 108 are preferably configured and dimensioned such that the force required to shift the tide 106 out of engagement with the groove 108 by pushing the plunger tube 40 further down into the case 12 is superior to the compressive force exerted on the needle holder assembly 14 by the compressed return spring 16, and additional force that acts upward on the needle 34 during catheter insertion procedures. An intravenous catheter 20 can be installed on the tip 26 of the case 12 before inserting the needle holder assembly 14 and the plunger assembly 18 into the case 12. Alternatively, the plunger assembly 18 and the needle holder assembly 14 (sometimes referred to as the needle holding assembly) can be assembled with each other before being inserted into the case 12. In a preferred embodiment, the friction engagement between the tide 106 and the groove 108, when engaged together, is sufficient so that the needle holder assembly 14 and the plunger assembly 18 can be inserted together into the case 12.

The tapered end 48 of the needle and the portion of the cannula 78 are preferably inserted into the vein of the patient while holding the annular projections 31 of the case 12 with the thumb and forefinger and middle finger. After the catheter is inserted into the patient’s vein, the needle holder assembly 14 is removed by gripping the shelves 30 or the annular protrusions 31 with the index and middle fingers or with the thumb and index and middle fingers, and then pressing the palm or its base on the end cover 66 to push the plunger tube 40 further down into the case 12 When this action is performed, the frictional engagement force between the tide 106 and the groove 108, as shown in FIG. 4, is overcome, and as a result, the tide 106 pops up onto the surface 112 of the tubular body 32. Continuing direction The downward movement of the plunger tube 40 relative to the tubular body 32, which firmly abuts the case 12, causes the tide 106 to fall over the inclined shoulder 114 of the tubular body 32. After that, there is no longer a significant friction force acting against the compressed return spring 16 and the spring 16 expands rapidly, forcing the needle holder assembly 14 to quickly move up into the cleaning cavity 76 while simultaneously removing the needle 34, at least to the position where the beveled end 48 is folded into the case 12.

As shown in FIG. 3, the return spring 16 is fully expanded and the upper end 52 of the needle holder assembly 14 is at least partially retracted into the cleaning cavity 76. The air previously in the cleaning cavity 76 in the plunger tube 40 was discharged through the air hole 72 when the needle holder assembly 14 moved upward in the cavity under the action of the expanding return spring 16. The upper end 52 of the needle holder assembly 14 was pushed upward in the cleaning cavity 76 to retract the tapered end 48 of the needle 34 into the case 12. When the needle 34 is in the position shown in FIG. 3, the tip 26 of the case 12 can be safely separated from the sleeve 80 of the intravenous catheter.

An improved guide for introducing an intravenous catheter according to the present invention is well suited for automated production and assembly. In addition to the catheter, needles and springs, only a case, a retractable needle holder and a plunger tube, closed with a cap with a hole, are required. Although the case 12 can be made straight in shape, with a straight inner wall, it is advisable to give the case a stepped shape, narrowing inward from the top to the bottom, excluding the lower shoulder of the annular protrusion 102. The said narrowing facilitates the removal of the core mandrel used in the molding process. Although not shown in the drawings, it should be understood that the beveled end 48 of the needle 34 is preferably covered during manufacture, transportation and storage by a tubular case that slides up the outer surface of the cannula 78 and does not allow damage to the needle.

An important feature of the proposed guide for introducing an intravenous catheter is that the operator can conveniently operate with one hand with a retractable conductor design for introducing a catheter. One-handed operation is possible because the plunger tube preferably extends from about 1.5 to about 3 inches from where the shelves of the case are. This allows you to apply force to the plunger tube with a palm cushion and simultaneously use your fingers on the shelves or near the ring protrusions of the case to resist the force and smoothly initiate retraction. The other arm remains free to grip the catheter sleeve. The release time of the sleeve from the conductor device and the attachment of the intravenous tube to the sleeve is completely controlled by the operator. The catheter sleeve can be separated in one motion from the insertion device, which can then be safely set aside until the connection to the intravenous tube or other device to be connected to the patient is then made. The guide for insertion of the catheter can be safely laid without problems on the table or in the tray, since the needle has already been removed to a safe position before disconnecting the catheter assembly from the case. When the shelves or ring protrusions of the case are pulled back by the fingers to retract, the operator can check both by ear and visually that the needle is in a safe position and immediately disconnect and safely set the device aside to release his hand to make the necessary intravenous connection before how will the patient lose fluid.

The conductor for introducing an intravenous catheter according to the present invention is not required to withstand the force exerted by the needle on the retractable parts as much as in the case of a conventional syringe when it is necessary to pierce a standard rubber seal on the vials. Consequently, retractable parts must be able to withstand without retraction only the force arising from normal clinical use. In the device proposed in the present description, dimensional tolerances and different rates of thermal expansion are less critical than in devices that provide only frictional engagement due to surface contact between smooth surfaces.

The conductor proposed here for introducing an intravenous catheter is less prone to premature needle removal than known devices, even with careless handling and a wide range of temperature and humidity changes during transportation and storage prior to use. The invention is characterized by a simple and rational form and a return spring, which is simpler and more reliable than other previously used springs. The device can be operated with one hand at any angular orientation, when there is access to the shelves, due to the absence of external latches on the device that require devices with a specific orientation to be positioned. In addition, the shelves prevent the conductor from rolling to insert a catheter when laying on an inclined surface. When the device is held in hand, a return force is applied linearly along the main longitudinal axis. A very short movement is enough to cause the removal. Correct cleaning is controlled both visually and by ear, since the operator can easily see the allotted parts in the case, and when removing it creates a weak sound.

Other changes and modifications of the above preferred embodiment will become apparent to those of ordinary skill in the art after reading the present description, and it is intended that the scope of the invention provided herein be limited only to the broadest interpretation of the appended claims to which the inventor has legal rights.

Claims (65)

1. A guide for introducing an intravenous catheter comprising a tubular case; a needle holder assembly with a tubular body engaged with a possibility of shear within the case; a retraction mechanism mounted in the annular space between the case and the needle holder assembly; a plunger assembly with a plunger tube engaged in releasably engaged with the tubular body inside the case; and a catheter attached in friction to the tubular case; in which the tubular body contains an outward circular groove proximal to the plunger tube; the plunger tube contains an inwardly directed annular tide proximal to the tubular body; and the circumferential groove and annular tide are pulled into releasable engagement. 2. A guide for introducing an intravenous catheter according to claim 1, wherein the retraction mechanism is a spring. 3. A guide for introducing an intravenous catheter according to claim 2, wherein the spring is a compressed spring. 4. A guide for introducing an intravenous catheter according to claim 1, wherein the tubular case and tubular body are made of transparent plastic. 5. A guide for introducing an intravenous catheter according to claim 4, in which the transparent plastic contains polycarbonate. 6. A guide for introducing an intravenous catheter according to claim 1, wherein the plunger tube has an end with an opening that is distal relative to the tubular body. 7. The conductor for introducing the intravenous catheter according to claim 6, in which the end with the hole contains a plastic end cap. 8. A guide for introducing an intravenous catheter according to claim 7, in which the plastic end cap is colored. 9. The conductor for introducing the intravenous catheter according to claim 6, in which the end with the hole contains an end cap with a hole for air and non-periodic structural elements of the surface relief surrounding the hole for air. 10. The conductor for introducing the intravenous catheter according to claim 6, in which the end with the hole contains an end cap with an annular bead, which is frictionally engaged in a plunger tube. 11. The guide for the introduction of the intravenous catheter according to claim 6, in which the end with the hole contains a glued end cap. 12. The conductor for introducing the intravenous catheter according to claim 6, in which the end with the hole contains an end cap fixed by ultrasonic welding. 13. The conductor for introducing the intravenous catheter according to claim 6, in which the end with the hole contains an end cap, which is made by two-jet casting on a plunger tube. 14. A guide for introducing an intravenous catheter according to claim 6, wherein the needle holder assembly comprises an expansion chamber with an internal space that is visible through no more than two layers of transparent plastic. 15. The guide for the introduction of an intravenous catheter according to claim 1, in which the node of the needle holder contains a filled needle. 16. A guide for introducing an intravenous catheter according to claim 1, wherein the needle is glued to the needle holder assembly. 17. A guide for introducing an intravenous catheter according to claim 1, wherein the needle is secured to the needle holder assembly by ultrasonic welding. 18. A guide for introducing an intravenous catheter according to claim 14, wherein the needle holder assembly comprises a needle, the end of which protrudes into the expansion chamber. 19. A guide for introducing an intravenous catheter according to claim 1, wherein the tubular body has a plug end, comprising an inwardly facing circular groove in the tubular body and a porous tube inserted with friction engagement with the circular groove. 20. A guide for introducing an intravenous catheter according to claim 19, wherein the circular groove in the tubular body is adjacent to a diverging outward portion of the inner wall of the tubular body. 21. The conductor for introducing the intravenous catheter according to claim 1, in which the tubular body further comprises a section of reduced diameter that is spatially spaced with a circular groove, and the plunger tube can be disengaged from the tubular body by applying a force to the plunger tube, which is sufficient to shift the annular tide from the circular groove along the tubular body to a point opposite the section of reduced diameter. 22. A guide for introducing an intravenous catheter according to claim 21, wherein the needle holder assembly is forcibly retracted into the plunger tube by a retraction mechanism when the annular tide is opposite a portion of a reduced diameter. 23. A guide for introducing an intravenous catheter according to claim 1, wherein the tubular case comprises an open end and a plurality of transversely protruding shelves adjacent to the open end. 24. A guide for introducing an intravenous catheter according to claim 1, wherein the catheter further comprises a cannula, depending on the sleeve attached to the tubular case. 25. A guide for introducing an intravenous catheter comprising a tubular case; a needle holder assembly with a tubular body engaged with a possibility of shear within the case; a retraction mechanism mounted in the annular space between the case and the needle holder assembly; a plunger assembly with a plunger tube engaged in releasably engaged with the tubular body inside the case; and a catheter attached in friction to the tubular case; in which the plunger tube has an end with an opening that is opposite to the tubular body. 26. The guide for the introduction of an intravenous catheter according A.25, in which the end with the hole contains a plastic end cap. 27. A guide for introducing an intravenous catheter according to claim 26, wherein the plastic end cap is colored. 28. A guide for introducing an intravenous catheter according to claim 25, wherein the end with the hole comprises an end cap with an air hole and non-periodic structural features of the surface relief surrounding the air hole. 29. The conductor for introducing the intravenous catheter according A.25, in which the end with the hole contains an end cap with an annular bead, which is frictionally engaged in a plunger tube. 30. The guide for the introduction of an intravenous catheter according A.25, in which the end with the hole contains a glued end cap. 31. A guide for introducing an intravenous catheter according to claim 25, wherein the end with the opening comprises an end cap fixed by ultrasonic welding. 32. The conductor for introducing the intravenous catheter according A.25, in which the end with the hole contains an end cap, which is made by two-jet casting on a plunger tube. 33. A guide for introducing an intravenous catheter according to claim 25, wherein the retraction mechanism is a spring. 34. A guide for introducing an intravenous catheter according to claim 33, wherein the spring is a compressed spring. 35. A guide for introducing an intravenous catheter according to claim 25, wherein the tubular case and tubular body are made of transparent plastic. 36. A guide for introducing an intravenous catheter according to claim 35, wherein the transparent plastic comprises polycarbonate. 37. A guide for introducing an intravenous catheter according to claim 35, wherein the needle holder assembly comprises an expansion chamber with an internal space that is visible through no more than two layers of transparent plastic. 38. A guide for introducing an intravenous catheter according to claim 25, wherein the needle holder assembly comprises a needle that has been inserted. 39. A guide for introducing an intravenous catheter according to claim 25, wherein the needle is glued to the needle holder assembly. 40. A guide for introducing an intravenous catheter according to claim 25, wherein the needle is secured to the needle holder assembly by ultrasonic welding. 41. A guide for introducing an intravenous catheter according to clause 37, wherein the needle holder assembly comprises a needle, the end of which protrudes into the expansion chamber. 42. A guide for introducing an intravenous catheter according to claim 25, wherein the tubular body has a plug-closed end comprising an inwardly facing circular groove in the tubular body and a porous plug inserted with friction engagement with the circular groove. 43. A guide for introducing an intravenous catheter according to claim 42, wherein the circular groove in the tubular body is adjacent to a diverging outward portion of the inner wall of the tubular body. 44. A guide for introducing an intravenous catheter according to claim 25, wherein the tubular case comprises an open end and a plurality of transversely protruding shelves adjacent to the open end. 45. A guide for introducing an intravenous catheter according to claim 25, wherein the catheter further comprises a cannula depending on a sleeve attached to the tubular case. 46. A guide for introducing an intravenous catheter, comprising a needle holder assembly and a plunger assembly, mounted coaxially and meshably displaceable within the tubular case, a catheter detachably connected to the tubular case, and a retraction mechanism pressing the needle holder assembly to the plunger assembly in which the assembly the needle holder comprises an elongated tubular body having a first end securing a hollow needle with a beveled end, a second end containing a porous plug held on friction mesh, races iritelnuyu chamber disposed between the first and second ends and communicating on the channel for the liquid with a hollow needle, and an outer wall with a circumferential groove disposed proximate the second end; the plunger assembly includes an elongated plunger tube having an open end that is engaged with the possibility of sliding along the second end of the tubular body of the needle holder assembly, an end with an opening opposite the open end, and an engaging structure protruding radially inwardly near the open end; the engaging structure is pressed into engagement with the circular groove of the needle holder assembly with a force sufficient to prevent the needle holder assembly from moving toward the plunger assembly with a retraction mechanism. 47. The guide for introducing an intravenous catheter according to claim 46, wherein the tubular body further comprises a relief structure relative to which the engaging structure can be shifted by manually overcoming the compressive force of the engaging structure to disengage the engaging structure from engagement with the circumferential groove. 48. A guide for introducing an intravenous catheter according to claim 46, wherein the engaging structure is an annular tide. 49. The guide for introducing the intravenous catheter according to item 46, in which the plunger tube contains a cavity for retraction, large enough to accommodate at least a portion of the needle holder assembly when retracting the needle to a position where the beveled end is inside the tubular case. 50. The conductor for introducing the intravenous catheter according to item 46, in which the end with the hole of the plunger tube contains an end cap mounted on a friction engagement. 51. A guide for introducing an intravenous catheter according to claim 50, wherein the end cap comprises an air hole and structural features of the surface relief surrounding the air hole. 52. The conductor for introducing the intravenous catheter according to item 46, in which the end with the hole contains a glued end cap. 53. A guide for introducing an intravenous catheter according to claim 46, wherein the end with the hole comprises an end cap fixed by ultrasonic welding. 54. The conductor for introducing the intravenous catheter according to item 46, in which the end with the hole contains an end cap, which is made by two-jet casting on a plunger tube. 55. A guide for introducing an intravenous catheter according to claim 46, wherein the tubular case and tubular body are made of transparent plastic. 56. A guide for introducing an intravenous catheter according to claim 46, wherein the retraction mechanism is a spring. 57. A guide for introducing an intravenous catheter according to claim 56, wherein the spring is a compressed spring. 58. A guide for introducing an intravenous catheter according to claim 46, wherein the catheter further comprises a cannula through which the cannula passes. 59. A guide for introducing an intravenous catheter comprising a tubular case; a needle holder assembly with a tubular body engaged with a possibility of shear within the case; a retraction mechanism mounted in the annular space between the case and the needle holder assembly; a plunger assembly with a plunger tube engaged in releasably engaged with the tubular body inside the case; and a catheter attached in friction to the tubular case; in which the tubular needle holder body comprises an upper end portion and a needle attachment portion, the upper end portion comprising an outwardly facing circular groove located in detachable mesh with an inwardly directed annular tide on the plunger tube, and the needle attachment portion extends through the retraction mechanism and protrudes in front of the tubular case . 60. A guide for introducing an intravenous catheter comprising a transparent plastic tubular case having a wide end, a narrow end, a stepped inner diameter between the wide and narrow ends, and transversely protruding shelves adjacent to the wide end; a needle holder assembly installed inside the case containing a hollow needle with a beveled end, a needle fastening element holding the needle coaxially to the case, a transparent plastic expansion chamber communicating through the fluid channel with the hollow needle, a porous plug plugging the expansion chamber at the end opposite the hollow needle, and a circular groove facing radially outward near the clogged end of the expansion chamber; a plunger assembly, additionally containing a transparent plastic plunger tube with an open end inserted into the case into the girth of a portion of the needle holder assembly, a cleaning cavity large enough to allow the tapered end of the needle to be retracted into the case after removal, the first structure protruding radially outward to engage the case , and a second structure protruding radially inward to engage with a circular groove; and an end cap provided with a hole plugging the plunger tube from a side opposite the open end; a retraction mechanism compressed inside the case around the needle attachment assembly and a pressing needle attachment assembly to the cavity for retraction in the plunger tube; and a catheter, covering with friction engagement the narrow end of the case and further comprising a cannula located coaxially with the hollow needle and with the possibility of sliding along it; in which the second structure engages in a circular groove to prevent the attachment of the needle attachment into the cavity for removal by the pressing force of the retraction mechanism and any additional force acting upward on the needle when the cannula is inserted into the patient. 61. A method of assembling a conductor for introducing an intravenous catheter, comprising the following steps: provide a tubular case with a wide end, a narrow end and a stepped inner wall; provide a needle attachment unit comprising a tubular body holding the hollow needle coaxially aligned and communicating through the fluid channel with a substantially cylindrical expansion chamber, wherein the expansion chamber is closed at the end opposite the needle with a porous plug, and the tubular body also has a spring guide portion and an outward circular groove near the plug end; provide a cylindrical return spring, capable of wrapping with a possibility of shifting the spring-guiding section of the tubular body; providing a plunger assembly comprising a plunger tube having an open end and an end with an opening, wherein the plunger tube has an outwardly protruding structure and an inwardly protruding structure near the open end; providing a catheter comprising a cannula and a tubular sleeve; attach the tubular sleeve for intravenous administration to the narrow end of the case; inserting a coil spring into the wide end of the case coaxially with the case; insert the needle attachment assembly into the wide end of the case coaxially with the case, and force the needle to slide down through the return spring and the cannula until the tubular body is installed inside the case and the return spring is located around the spring guide; insert the plunger tube into the wide end of the case coaxially with the case and the needle attachment assembly, and force the open end of the plunger tube to advance over the plugged end of the needle holder assembly until the outwardly protruding structure engages with the stepped inner wall of the case and the inwardly protruding structure enters meshing with a circular groove, thereby compressing the return spring, and ensuring that the return spring is held in a compressed state by engagement between the inwardly protruding structure circumferential groove. 62. The method of claim 61, wherein the return spring is mounted on the needle mount assembly before the needle mount assembly is inserted into the wide end of the case. 63. The method of claim 61, wherein the plunger tube is engaged with the needle attachment assembly before the needle attachment assembly is inserted into the wide end of the case. 64. The method according to p, in which the node attaching the needle is first provided without a needle, and then the needle is glued to the node attaching the needle after inserting the node attaching the needle to the case. 65. The method of claim 61, wherein the needle mount assembly is first provided without a needle, and then the needle is secured by ultrasonic welding in the needle mount assembly after inserting the needle mount assembly into the case.

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