JPH0118748B2 - - Google Patents

Description

[Detailed Description of the Invention] () Background of the Invention (-1) Technical Field This invention is used for artificial dialysis, etc., in which an indwelling catheter fitted on the outside of the inner needle is inserted into a blood vessel and placed as a guide. Regarding intravascular indwelling needles.

(-2) Prior art and its problems A conventional intravascular indwelling needle is shown in Figure 1. This intravascular indwelling needle consists of an inner needle assembly A and an indwelling catheter assembly B. The indwelling catheter assembly B is made by integrally integrating a catheter hub 2, a flexible tube 3, and a connector 4 to an indwelling catheter 1 in this order using adhesive or the like. The inner needle assembly A consists of an inner needle 5, an inner needle hub 7 supporting it, and a cap 8, and the inner needle 5 is connected to the connector 4 and connected to the catheter. The blade is inserted into the inside of the blade 1 and the leading edge of the blade is made to protrude by a required length. The seal cap 6 is inserted into the inner needle and fitted onto the connector so as to fill the gap between the connector 4 and the inner needle 5 inserted therein, and the cap 8 allows air to pass through, but It has a blood leakage resistant member that does not allow blood to pass through. The seal cap 6 is made of soft rubber or the like, and is fitted onto the connector 4 before the inner needle 5 is inserted.As shown in FIG. The outer surface of the small cylindrical portion 6d, which sandwiches the thin film portion 6c and forms the small hole 6a, is a tapered cylindrical surface that fluid-tightly fits into the tapered cylindrical surface 4a on the inner surface of the connector 4, and the large cylindrical portion 6e has a small cylindrical surface. After the part 6d is fitted into the connector 4, it is turned over and placed over the connector 4 in a tight state. The inner needle 5 is then inserted into the indwelling catheter by piercing the thin film portion 6c of the seal cap 6 attached to the connector 4 as described above.

However, in the above-mentioned intravascular indwelling needle, since the inner needle 5 pierces the thin film portion 6c of the seal cap 6, the cutting edge of the tip of the inner needle 5 is often damaged, and the sharpness of the inner needle cutting edge is deteriorated when piercing the blood vessel. The symptoms worsened, causing pain to the patient. Furthermore, when withdrawing the indwelling catheter 1 after indwelling it in a blood vessel using the inner needle 5 as a guide, the thin film portion 6c of the seal cap 6 is tightly fitted onto the inner needle 5, so that there is no frictional resistance when pulling it out. When the tube 3 expands slightly in the pulling direction and the tensile strength of the tube 3 overcomes the pulling friction resistance of the inner needle 5, the thin film portion 6c of the seal cap 6
suddenly slides against the inner needle 5, causing the tube 3 to shrink to its original length. For this reason, the doctor's arm tends to shake, making it unstable to pull out the inner needle 5, and safe operation cannot necessarily be expected. Furthermore, after the inner needle 5 is pulled out, the thin film part 6c of the seal cap 6 is said to have a role as a leakage-proof stopper by closing the opening caused by the inner needle penetration due to the elasticity of the rubber, and thereby, the tube 3 can be inserted into the tube 3. It is said that there is no need to close the tube with forceps, etc. However, in many cases, this effect is not achieved because the elasticity weakens due to heating during sterilization or changes over time. Furthermore, the seal cap 6 is connected to the connector 4.
It is complicated and troublesome to do it with one hand because it is removed by flipping up the large diameter cylindrical part 6e that is placed over the body. Furthermore, when puncturing a blood vessel with the inner needle 5, the blade tip usually weighs about 400 g.
Receives a puncture reaction force of 600g or more from the skin, etc.
Therefore, when holding the catheter hub 2 and puncturing a blood vessel, the inner needle 5 punctures the thin film part 6c of the seal cap 6 and is resiliently supported, but the inner needle 5 slides on the thin film part 6c and the cutting edge becomes attached to the indwelling catheter. 1, making it impossible to puncture, causing severe pain to the patient, and making it impossible to secure a blood vessel.Furthermore, the seal cap 6 sometimes came off, causing blood to leak.

In consideration of the above points, improvements have been made to the intravascular indwelling needle shown in FIG. 3. In addition to the improved seal cap, this intravascular indwelling needle also has an improved stopper for regulating the insertion depth of the inner needle into the indwelling catheter. However, the improvement of the stopper does not solve the problem that the inner needle tip retreats into the indwelling catheter 1 during puncturing. In FIG. 3, the same members as those in FIG. Connector 4 is formed into a shaft shape and has a small diameter outer surface.
It has a tapered cylindrical surface 9a that is liquid-tightly fitted to the tapered cylindrical surface on the inner surface of the tube, and has a corresponding insertion hole 9b through which the inner needle 5 is inserted in a liquid-tight manner. Further, a stopper 10 made of a rod-shaped member extending from the inner needle hub 7 toward the catheter in parallel with the inner needle is provided, and the distal end of the stopper 10 is received by a stopper receiver 11 provided on the catheter hub 2.

However, although the improved intravascular indwelling needle as described above can overcome the drawbacks of the seal cap of the conventional intravascular indwelling needle shown in FIG. Ivy. The first point is that the seal cap 9 is only tapered fitted to the connector 4, so if the tapers do not match properly, the fitting depth will not be constant and the taper contact area of the seal cap with the connector taper will increase. Since the is small, the fitting force becomes weak, and the resistance of the tapered part of the seal cap against the taper of the connector decreases.In addition, the expansion pressure of the air in the tube 3 due to heating during sterilization loosens the fitting of the taper, and when the inner needle retracts, the fitting force becomes weak. There is an inconvenience that the seal cap 9 comes off and blood leaks. Second, since this type of intravascular indwelling needle is punctured with one hand, the length of the inner needle 5 is required to be as short as possible for doctors with small palms to improve operability. Since the seal cap 9 has a two-stage shaft shape, it is longer than the intravascular indwelling needle shown in FIG. 1 described above, and the operability is rather poor. Third, since the seal cap 9 has a two-stage shaft shape, it is possible to make the mistake of inadvertently pulling out the seal cap 9 without holding the inner needle hub 7 when retracting the inner needle 5. . As a fourth point, the insertion end surface 9c of the seal cap 9 is rounded and the tapered cylindrical surface 9
When the inner needle 5 is inserted and fitted into the seal cap 9, if the inner needle 5 is coated with a lubricant such as silicone oil and inserted into the inner needle insertion hole 9b, if the seal cap 9 is made of polyethylene or the like, the inner needle will not be inserted through the seal cap 9. The stress applied to the surface of the hole 9b could not be maintained by the tapered cylindrical surface 9a, and cracks occurred in the seal cap 9, causing blood to leak, especially when silicone oil was present. The fifth point is that, as with the intravascular indwelling needle shown in FIG. If you try to do so, it will not only cause severe pain to the patient, but also make it impossible to secure the blood vessel.Therefore, pinch the catheter hub 2 with your thumb and forefinger, and pinch the inner needle hub 7 with the back of your palm, ring finger, and little finger, and remove the inner needle 5. Puncturing must be performed while ensuring that the blade tip does not retreat into the catheter 1, making the operation complicated and troublesome, and also making it difficult or impossible for doctors with small palms to hold such an intravascular indwelling needle. It was possible.

() Purpose of the Invention The present invention was devised in view of the drawbacks of the conventional intravascular indwelling needles shown in FIGS. 1 to 3 explained above. When the inner needle is retracted after being inserted into the inner needle, the seal cap does not come off from the connector to prevent blood leakage, and the length of the inner needle is shorter than that shown in Fig. The seal cap can be made equivalent to the one shown in the figure, without reducing operability, and the appearance of the seal cap has been improved to prevent careless mistakes such as pulling out the seal cap without holding the hub attached to the inner needle when retracting the inner needle. When it is necessary to retract only the inner needle into the connector, close the tube with forceps, etc., and remove the seal cap along with the inner needle, it can be easily and hassle-free with one hand without applying much force, and the indwelling catheter can be indwelled. The purpose of the present invention is to provide an intravascular indwelling needle that can be safely operated without adversely affecting the blood vessels in the body.

According to the present invention, a catheter hub, a flexible tube, and a connector are integrally connected in this order to the rear end of an indwelling catheter that is inserted into a blood vessel using an inner needle as a guide. An inner needle with a needle hub integrally connected thereto is inserted into the catheter through the connector so that its tip protrudes by a required dimension, and the inner needle is inserted into the connector in a fluid-tight manner, and a seal cap is provided to fit into the connector. In the intravascular indwelling needle, the seal cap includes a protrusion that is fluid-tightly fitted to the inner surface of the connector, and an inner needle that can be slidably inserted into the protrusion while maintaining the inner needle in a fluid-tight state. an inner needle insertion hole, an outer cylindrical portion that exists outside the protruding portion and fits on the outside of the connector, and an outer cylindrical portion that exists between the outer cylindrical portion and the protruded portion and that is connected to the seal cap. This is achieved by an intravascular indwelling needle characterized in that it is an elastic molded body having one of the locking means for locking the connector, and the other of the locking means is provided on the connector. Ru. That is, by providing the locking means, it is possible to prevent the seal cap from coming off the connector during sterilization or when the inner needle is retracted, and even if the seal cap is pulled due to careless mistake, the release function of the locking means can be maintained. Furthermore, the seal cap can be removed by covering the outside of the connector with the outer tube, which also serves as a knob for removal. It is possible to maintain the same level of appearance and to avoid the mistake of inadvertent pulling out of the seal cap when the inner needle is retracted.

The above-mentioned locking means shall be configured such that when the inner needle is withdrawn together with the inner needle when the inner needle is retracted, the lock can be easily released with one hand so that the indwelling catheter currently indwelled in the blood vessel does not shake or move. is extremely useful for intravascular indwelling needles.

Therefore, the present invention provides an improved intravascular indwelling device in which the seal cap cannot be removed by simply pulling it, but can be easily removed with one hand without applying much force by twisting or flattening it while pulling it out. It provides needles.

According to the present invention, the improved intravascular indwelling needle has the locking means being one of a male thread and a female thread formed on the inner surface of the outer cylindrical portion of the seal cap as a threaded connection, and the locking means is one of a male thread and a female thread formed on the inner surface of the outer cylindrical portion of the seal cap, and An embodiment characterized in that the other of the male thread and the female thread is formed on the outer surface,
and the locking means is a threaded connection in which the seal cap has an intermediate cylindrical part between the protruding part and the outer cylindrical part, one of a male thread and a female thread formed on the outer surface thereof, and the connector is thicker than the end face. An embodiment characterized in that the other of the male thread and the female thread is formed on the outer wall thereof, and the locking means is provided with an annular groove for accommodating the intermediate cylinder part. It is one of the L-shaped slits in the outer cylinder part and a protrusion that penetrates into the L-shaped slits in an L-shape and engages with them, and an L-shaped slit in the outer surface of the connector, and a protrusion that penetrates into the L-shaped slits in an L-shape and engages with them. In an embodiment characterized in that the other of the mating protrusions and the locking means are
There are L-shaped grooves and L-shaped grooves on the inner surface of the outer cylinder of the seal cap.
One of the protrusions that enters and engages the L-shaped groove, and the other of the L-shaped groove that enters and engages the L-shaped groove on the outer surface of the connector. The locking means is a straight groove formed on the inner surface of the outer cylindrical portion of the seal cap, and a straight groove is formed in a straight line from the edge of the seal cap, and the depth end thereof is a recess that is one step deeper. A straight groove that is one of the protrusions that enters the connector, falls into the recess, and engages, and is also formed on the outer surface of the connector. The other of the protrusions that enters and falls into the recess to engage, and the locking means is the other of the protrusions and is characterized by providing a required gap between the outer cylinder and the connector, and the locking means A protrusion is formed on the outer surface of the seal cap, and a protrusion is formed on the inner surface of the outer cylindrical portion of the seal cap to engage with the protrusion from the flexible tube side. achieved.

Further, according to the present invention, the inner surface of the connector is formed into a female tapered cylindrical surface whose diameter increases toward the end surface, and the external surface of the protrusion of the seal cap is formed into a male tapered cylindrical surface that is liquid-tightly fitted to the female tapered cylindrical surface. By forming the seal cap, blood leakage from the seal cap can be prevented.

Furthermore, according to the present invention, by forming the tapered cylindrical surface and the end surface of the protruding part of the seal cap to intersect at a corner without roundness, occurrence of cracks at the tip of the protruding part of the seal cap is prevented and blood leakage is prevented. It can be prevented.

Furthermore, according to the present invention, a locking portion is integrally provided on the outer surface of the inner needle on the side closer to the cutting edge than the seal cap, which abuts against the seal cap and prevents the inner needle cutting edge from retreating into the indwelling catheter during puncture. This allows the operator to puncture the catheter by holding only the catheter hub, allowing even people with small palms to handle it.

() Detailed Description of the Invention (-1) Configuration The intravascular indwelling needle of the embodiment shown in FIG. The hub 2, flexible tube 3, and connector 4 are sequentially connected together with an adhesive or the like, and the inner needle 5 is inserted into the catheter 1 through the connector 4 so that its distal tip protrudes by a required length, and the connector 4 is then connected to the connector 4. A cap 8 is provided with a seal cap 12 through which the inner needle 5 is inserted and which is fitted onto the connector 4 so as to fill the gap between the inner needle 5 and the inner needle 5 inserted therein, and a cap 8 having a blood leakage-resistant member on the inner needle hub 7. is installed.

The above configuration is the same as the conventional configuration shown in FIGS. 1 and 3.

The intravascular indwelling needle of the embodiment shown in FIG. 4 has the above-described structure, and further includes a stopper 10 made of a rod-shaped member extending in the catheter direction in parallel with the inner needle 5, and the tip of the stopper 10 is connected to the catheter hub 2. A configuration is added in which the required length of the tip of the inner needle 5 is restricted from protruding from the indwelling catheter 1 by being received by a stopper receiver 11 provided in the holder 11, but the configuration of this additional part is the same as the configuration shown in FIG. Yes, it is not a prerequisite for this invention. The general materials of each member are: the indwelling catheter 1 is made of soft fluorine resin, the catheter hub 2 is made of hard polycarbonate,
The flexible tube 3 is made of soft polyvinyl chloride, the connector 4 is made of polycarbonate, the cap 8 is made of polypropylene, and the seal cap 12 is made of polypropylene elastomer. However, it is not limited to these.

The gist of this invention is to improve the seal cap 12. Further, it is preferable to provide an inner needle locking portion 13 for preventing the cutting edge of the inner needle 5 from retreating into the indwelling catheter 1 during puncture. The inner needle locking portion 13 is provided on the outer surface of the inner needle 5 on the cutting edge side than the seal cap 12 so as to be in contact with the seal cap 12, and its cross section along the direction of the inner needle is as shown in FIG. The needle is formed into a chevron-shaped or arcuate shape so that it can produce a wedge effect when the needle is pulled out, thereby expanding the inner needle insertion hole of the seal cap 12 and allowing the needle to pass through. The inner needle locking portion 13 can be formed by placing the inner needle in a mold, or by fitting an abacus bead-shaped member made of plastic such as polypropylene or polyvinyl chloride or stainless steel onto the inner needle and using an adhesive or the like. Possible methods include gluing, or applying metal such as silver solder or solder to the outer periphery of the inner needle.
Since the seal cap 12 is fitted over the connector 4, the modification to provide the locking function not only applies to the seal cap 12 but also includes the connector 4, which is shown enlarged in FIG. To explain, the seal cap 12 has a female tapered cylindrical surface 4 on the inner surface of the connector 4 that becomes larger in diameter toward the end surface.
a protrusion 12a that forms a liquid-tight fit thereto;
an inner needle insertion hole 12b that exists inside the protruding part 12a and into which the inner needle 5 can be slidably inserted while maintaining it in a liquid-tight state; Outer cylinder part 1 for removal that covers the outside of the connector 4
2c, two female threads 12d which are one of the locking means formed on the inner surface of the outer cylinder part 12c, and an end surface part 12e that connects these parts together. A protrusion 4b, which is the other of the locking means and substantially corresponds to two male threads, is formed on the outer edge (claim 2).
Section 8). Therefore, according to the locking means of this embodiment, the seal cap 12 is connected to the connector 4.
This configuration allows you to simultaneously achieve tapered cylindrical surface fitting and screw connection by placing the screw over the tube and turning the screw. The seal cap 12 has a tapered surface 1 of the protrusion 12a to prevent cracks from entering the protrusion 12a.
2f and the end surface 12g intersect at a corner without roundness (Claim 9).

(-2) Action First, for assembly, cover the connector 4 with the seal cap 12, apply silicone oil to the inner needle 5, insert it into the inner needle insertion hole 12b, and insert the tip of the inner needle 5 from the indwelling catheter 1 to the required length. This is achieved by causing the inner needle 5 and the indwelling catheter 1 to protrude and at the same time receiving the tip of the stopper 10 in the stopper receiver 11 to fix the inner needle 5 and the indwelling catheter 1 to each other. The seal cap 12 may be placed over the connector 4 after the inner needle 5 is inserted therethrough. The seal cap 12 is the inner needle locking part 1
Insert the inner needle 5 until it passes through the needle 3.

After the thus assembled intravascular indwelling needle is covered with a protector (not shown) on the outside of the indwelling catheter 1, it is further packaged, gas sterilized, and provided to medical institutions as a product.

It has been confirmed through trial production that during long-term storage, when the tapered cylindrical surface 12f and end surface 12g of the seal cap 12 are made to intersect at an unrounded corner, no cracks occur in the protruding portion 12a of the seal cap 12. To pierce a blood vessel with an intravascular indwelling needle, the catheter hub 2 is held and pierced into the blood vessel. In this case, the cutting edge of the inner needle 5 should be 400 mm away from the skin, etc.
Although a puncture reaction force of between 1.5 g and 600 g is applied, the inner needle locking portion 13 provided integrally with the inner needle 5 is in contact with the end surface 12g of the protruding portion 12a of the seal cap 12, and the cutting edge of the inner needle 5 is It will not be pulled into the indwelling catheter 1. In this way, when the intravascular indwelling needle is inserted into the blood vessel, blood flows into the inner needle 5 by the action of the cap 8 equipped with a blood leakage-resistant member and reaches the transparent inner needle hub 7, so that the tip of the inner needle 5 is securely fixed. Make sure that it is located within the blood vessel. After this confirmation, using the inner needle 5 as a guide, push the tip of the indwelling catheter 1 together with the inner needle 5 into the blood vessel to the required size,
Thereafter, the inner needle 5 is slowly retreated, and if the indwelling catheter 1 is made of transparent or translucent material, it is confirmed that blood flows into the gap between the indwelling catheter 1 and the inner needle 5. Next, the catheter hub 2 is held with one hand, the inner needle hub 7 is held with the other hand, and the inner needle 5 is gently pulled out to the connector 4. In this case, there is the inner needle locking part 13, so it weighs about 800g.
The force of 1000 g is applied to the inner needle locking part 13 by creating a wedge action, and the seal cap 12 made of an elastic body is
The inner needle 5 is pulled out by expanding the inner needle insertion hole 12 until it passes through, and then the inner needle is pulled out with a small force. The inner needle 5 is pulled out until it reaches the connector 4 and is not pulled out from the connector 4. Then, the blood enters the flexible tube 3 through the indwelling catheter 1 by the volume that the inner needle 5 has retreated, but since the inner needle 5 is filled with blood, the blood does not flow into the flexible tube 3 from the beginning. Since the escape route of the enclosed air is blocked, the infiltration of blood into the flexible tube 3 stops when it reaches a certain point.
Next, the tube 3 is pinched in the middle with fingers or forceps to close it off, and then the seal cap 12 is turned and removed from the connector 4. As a result, the inner needle 5,
The inner needle hub 7, etc. can be removed as a whole. Next, the fingers or forceps may be loosened slightly to guide the blood into the connector 4 until it is filled with a predetermined amount, and this state may be maintained to connect one end of the blood circulation circuit or the like to prevent air from entering. As mentioned above, when the inner needle 5 is pulled out to the connector 4, the seal cap 12 is shaped to cover the connector 4, so it is difficult to remove the seal cap 12 by mistaking it for the inner needle hub 7. The number of mistakes caused by carelessness is reduced compared to before, and since the seal cap 12 cannot be removed by simply pulling the inner needle 5 straight, the seal is removed in the process of retracting the inner needle 5 to the connector 4. The cap 12 cannot be removed from the connector 4.

(-3) Modification (-3-1) Modification regarding the type of indwelling needle Figure 7 shows a modification regarding the type of indwelling needle of the present invention, which allows the puncture site to be set at one location in artificial dialysis, etc. A double-tube intravascular indwelling needle is shown. The improvement over the conventional double-tube intravascular indwelling needle is that it is equipped with the same seal cap 12 and connector 4 as the single-tube intravascular indwelling needle shown in FIG. Double tube catheter 1A and Y-shaped hub 2
A. Tube 3A is no different from the conventional one. Similar improvements have been made to the connector 4A on the blood circulation side and the cap 14 that covers it. The cap 14, unlike the seal cap 12, does not have an inner needle insertion hole.

The rest of the structure is the same as the single-tube type shown in FIG. 4, so the same reference numerals are given and the explanation will be omitted.

The method of using the double-tube type intravascular indwelling needle is slightly different from that of the single-tube type described above, but since it is well known, the explanation will be omitted. Furthermore, the effects of the improvements according to the present invention are the same as those of the single-tube type, so a description thereof will be omitted.

(-3-2) Modification examples related to main parts Figures 8 to 20 each show the connector 4.
This is a modification of the main part showing a combination structure of the seal cap 12 and the seal cap 12.

According to the modification shown in FIG. 8, the locking means is a screw connection, and an intermediate cylindrical portion 12h is provided between the protruding portion 12a and the outer cylindrical portion 12c, and the outer surface of the intermediate cylindrical portion 12h is substantially equivalent to two male threads. The intermediate cylindrical portion 12h is formed within the thickness of the end surface of the other connector 4.
A female thread 4d is formed on the outer wall of an annular groove 4c that can accommodate the screws, and in this modification, the male and female threads are reversed compared to the threaded connection of the embodiment shown in FIG. section).

According to the modification shown in FIGS. 9 and 10, the locking means is an L-shaped slit 12j that is cut in an L-shape from the end surface of the outer cylindrical portion of the seal cap 12.
and a protrusion 4e that enters and engages the L-shaped slit 12j on the outer surface of the other connector 4.
(Claim 4).

According to the modification shown in FIGS. 11 and 12,
The locking means is formed by forming an L-shaped groove 4f in the outer surface of the connector 4 from the edge thereof, and forming an L-shaped groove 4f in the inner surface of the outer cylindrical portion 12c of the seal cap 12. protrusion 12K that enters and engages with the
(Claim 4).

According to the embodiment shown in FIGS. 13 and 14,
The locking means is the outer cylindrical portion 12c of the seal cap 12.
An L-shaped groove 12l is formed on the inner surface of the connector 4 in an L-shaped shape dug from the edge thereof, and a projection 4 on the outer surface of the connector 4 that enters the L-shaped groove 12l in an L-shape and engages with the L-shaped groove 12l.
(Claim 5).

According to the embodiment shown in FIGS. 15 and 16,
The locking means is formed by forming a straight groove 12 m on the inner surface of the outer cylindrical portion 12 c of the seal cap 12 in a straight line shallower than the edge thereof, with the deep end being a deeper recess, and on the outer surface of the connector 4 on the other hand. A protrusion 4h that penetrates into the 12 m depth and falls into and engages with the recess at the depth end is formed, and the outer cylindrical portion 12c is further inserted into two straight grooves 12 m with a finger.
A required gap is maintained between the outer cylinder part 12c and the connector 4 to enable the projection 4h to float above the recess by compressing it more lightly than in the diametrical direction perpendicular to the axis through which the projection 4h passes (Claim 6 section).

Therefore, in this embodiment, seal cap 1
2 to the connector 4 can be done without compressing the seal cap 12, and removal can be done by compressing it to make the protrusion 4h float up and then pulling it out.

According to the embodiment shown in FIGS. 17 and 18,
The locking means has a structure reversed from the embodiment shown in FIGS. 15 and 16 above. That is, the locking means is formed by forming a straight groove 4i on the outer surface of the connector 4 in a straight line from the edge thereof and having a deeper recess at the deep end, and on the other hand, on the inner surface of the outer cylindrical portion 12c of the seal cap 12, a straight groove 4i is formed. A protrusion 12n that can penetrate into the straight groove 4i and fall into and engage with the recess at the deep end is formed, and a required gap is provided between the outer cylinder part 12c and the connector 4 (Claim 6). .

According to the embodiments shown in FIGS. 19 and 20, the locking means includes a protrusion 4j formed on the outer surface of the connector 4 at a position a certain distance from the end surface, and a protrusion 4j formed on the inner surface of the outer cylindrical portion 12c of the seal cap 12. By inserting the protrusion 4j further toward the tube side and then twisting the protrusion 12o, a protrusion 12o is formed which engages from the tube side back to back (Claim 7).

As can be seen from the above modifications, the locking means is
According to this invention, the seal cap 12 exists between the outer cylindrical portion 12c and the protruding portion 12a, and simultaneously locks the tapered cylindrical surface fitting between the protruding portion 12a and the connector 4. Any configuration may be used as long as it is possible. In other words, the locking means can be easily removed with one hand, and when the locking means is loosened, the tapered cylindrical surface fitting between the protrusion 12a and the connector 4 is also loosened at the same time.

() Specific Effects of the Invention As explained above, the intravascular indwelling needle of the present invention connects an indwelling catheter with a catheter hub, a flexible tube, and a connector, and attaches a seal cap to the connector. In the case where the inner needle is passed through the seal cap, the seal cap includes a protruding part that fits into the connector and has an inner needle insertion hole, an outer cylindrical part that covers the connector, and one side of the locking means between the protruding part and the outer cylindrical part. It is configured as an elastic molded body.

Therefore, according to the intravascular indwelling needle of the present invention, in the past, the seal cap often came off from the connector during sterilization during the manufacturing process and when pulling out the inner needle, but now it is equipped with a locking means. In addition, by providing the locking means, even if the seal cap is pulled due to careless mistake, it will not come off unless the release function of the locking means is met, and the seal will remain intact. Blood does not leak from the cap, and when it is necessary to remove the seal cap, it can be easily removed with a small amount of force if done in conjunction with the release function of the locking means, reducing camera shake when removing the seal cap. The risk of damage to the blood vessel due to the indwelling catheter placed in the blood vessel is reduced, and the safety of the indwelling needle is maintained.

Further, according to the intravascular indwelling needle of the present invention, the connector is covered with the outer cylindrical part of the seal cap, and the end face part is made relatively thin, so that the connector and the seal cap have a uniform appearance. Therefore, it is possible to reduce mistakes caused by carelessness such as pulling out the seal cap when retracting the inner needle, and the length of the inner needle can be shortened to the same length as the conventional indwelling needle shown in Fig. 1. Good operability can be maintained even for doctors with small palms.

Furthermore, if the inner needle of the intravascular indwelling needle of the present invention is provided with an inner needle locking part that comes into contact with the protruding part of the seal cap, which is an elastic molded body, on the outside of the inner needle, a weight of 400 g to 600 g will be applied to the cutting edge during puncturing. Even if the cutting edge receives a puncture reaction force, there is no fear that the cutting edge of the inner needle will be pulled into the indwelling catheter.When pulling out the inner needle after puncture, applying a pulling force of 800g to 1000g will remove the inner needle from the inner needle locking part. Since the cross section along the direction is chevron-shaped or arc-shaped to create a wedge effect, the inner needle locking part can be easily expanded through the seal cap and passed through, and subsequent withdrawal can be performed with extremely small force. Therefore, although the operation of pulling out the inner needle requires a slightly larger force than the conventional one, this force is applied for the partial stroke of pulling out the inner needle, and it is important to keep this force to at most 1000g or less to improve the fitting strength. Since it can be adjusted sufficiently, when the inner needle is withdrawn, there is no withdrawal force that causes large swings in the indwelling catheter that is subsequently placed in the blood vessel, so safe operability can be ensured.

Furthermore, the intravascular indwelling needle of the present invention includes an engagement locking means between the seal cap and the connector.
In the case of a screw connection, a connection between a protrusion and an L-shaped slit, an L-shaped groove, or a recess, or a connection by twisting the protrusion stoppers past each other, the seal cap cannot be simply pulled straight. In addition to the above-mentioned effect, it does not come off, but if you pull it out while twisting or flattening it, you can easily remove it with one hand without applying much force.

Furthermore, the inner surface of the connector is formed into a female tapered cylindrical surface that becomes larger in diameter toward the end surface, and the inner cylindrical portion of the seal cap is formed with a male tapered cylindrical surface for a liquid-tight fit, which prevents blood from leaking. .

Furthermore, as the intravascular indwelling needle of this invention,
According to an embodiment in which the tapered cylindrical surface and end surface of the protruding portion of the seal cap are formed with unrounded corners, it is possible to prevent the occurrence of cracks in the seal cap that occur in the conventional seal cap shown in FIG. Blood leakage can be prevented.

[Brief explanation of drawings]

Figure 1 is a partially sectional front view of a conventional intravascular indwelling needle, Figure 2 is a longitudinal sectional front view of a seal cap used in the same indwelling needle before installation, and Figure 3 is the intravascular indwelling needle of Figure 1. FIG. 4 is a partially sectional front view of another conventional intravascular indwelling needle with an improved needle; FIG. 4 is a partially sectional front view of an embodiment of the intravascular indwelling needle of the present invention;
5 and 6 are partially enlarged views of FIG. 4, FIG. 7 is a partial sectional view showing a modification of the intravascular indwelling needle of the present invention in a double tube type, and FIGS. 20
The figures show essential parts of a modified example of the intravascular indwelling needle of the present invention, in which FIG. 8 is a cross-sectional view of an embodiment in which the engagement lock means is screwed together, and FIG. 10 is a cross-sectional view of an embodiment in which the L-shaped slits are used for connection, and FIG.
The figure is a cross-sectional view of an embodiment in which the engagement locking means is combined with a protrusion and an L-shaped groove, FIG. 12 is a front view of the same as above before connection, and FIG. 13 is a cross-section of the embodiment shown in FIG. 11 when it is reversed. FIG. 14 is a front view of the same as above before connection, FIG. 15 is a sectional view of an embodiment in which the engagement locking means is connected by a protrusion and a recess, FIG. 16 is a front view of same as above before connection, and FIG. 17 is the first locking means.
Cross-sectional view when the mode shown in FIG. 5 is reversed, No. 18
FIG. 19 is a sectional view of an embodiment in which the engagement lock means is connected between protrusions, and FIG. 20 is a front view of the same before connection. 1... Indwelling catheter, 2... Catheter hub, 2A... Y-shaped hub, 33A... Tube, 4
4A... Connector, 5... Inner needle, 7... Inner needle hub, 12... Seal cap, 4a... Female taper cylindrical surface, 4b... Protrusion, 4c... Annular groove, 4d...
...Female thread, 4e...Protrusion, 4f...L-shaped groove, 4g
...Protrusion, 4h...Protrusion, 4i...Straight groove, 4j...
...Protrusion, 12a... Projection, 12b... Inner needle insertion hole, 12c... Outer cylinder part, 12d... Female thread, 12
e...End face part, 12f...Tapered cylinder surface, 12g
...End face, 12h...Intermediate cylinder part, 12i...Protrusion, 12j...L-shaped slit, 12k...Protrusion,
12l...L-shaped groove, 12m...straight groove, 12n...
Projection, 12o...Protrusion, 13...Inner needle locking part.

Claims (1)

[Scope of Claims] 1. A catheter hub, a flexible tube, and a connector are integrally connected in this order to the rear end of an indwelling catheter that is inserted into a blood vessel using an inner needle as a guide, and the inner needle is attached to the rear end. A hollow inner needle integrally connected to the hub is inserted into the catheter through the connector, its tip is made to protrude by a required dimension, and the inner needle is inserted into the connector in a fluid-tight manner, and a seal cap is fitted onto the connector. In the intravascular indwelling needle, the seal cap includes a protrusion that is fluid-tightly fitted to the inner surface of the connector, and an inner needle that is slidable inside the protrusion while maintaining the inner needle in a fluid-tight state. an inner needle insertion hole through which the needle can be inserted; an outer cylindrical portion that exists outside the protrusion and fits on the outside of the connector; and a seal that exists between the outer cylindrical portion and the protrusion. An intravascular indwelling needle, characterized in that it is an elastic molded body comprising a cap and one of locking means for locking the connector, and the other of the locking means is provided on the connector. 2. The locking means is one of a male thread and a female thread formed on the inner surface of the outer cylinder part of the seal cap as a threaded connection, and the other of the male thread and female thread formed on the outer surface of the connector. An intravascular indwelling needle according to claim 1. 3. The locking means is a threaded connection in which the seal cap has an intermediate cylindrical part between the protruding part and the outer cylindrical part, one of a male thread and a female thread formed on the outer surface of the seal cap, and the connector is thicker than the end face. 2. The intravascular indwelling needle according to claim 1, wherein the other of the male thread and the female thread is formed on an outer wall thereof and has an annular groove for accommodating the intermediate cylindrical portion. 4. The locking means is one of an L-shaped slit drilled into the outer cylindrical portion of the seal cap and a protrusion that enters and engages the L-shaped slit in an L-shaped manner, and is also cut into the outer surface of the connector. The intravascular indwelling needle according to claim 1, wherein the other of the L-shaped slit and the protrusion that enters and engages the L-shaped slit in an L-shape. 5. The locking means is one of an L-shaped groove dug into the inner surface of the outer cylindrical portion of the seal cap, and a protrusion that enters and engages the L-shaped groove in an L-shaped manner, and is also formed by digging into the outer surface of the connector. The intravascular indwelling needle according to claim 1, wherein the other of the L-shaped groove inserted therein and the protrusion that enters and engages the L-shaped groove. 6. The locking means includes a straight groove formed on the inner surface of the outer cylindrical portion of the seal cap in a straight line from the edge to form a deeper recess at the deep end; The intravascular indwelling needle according to claim 1, wherein the other of the mating protrusions is provided with a required distance between the outer cylinder and the connector. 7. A patent characterized in that the locking means includes a protrusion formed on the outer surface of the connector, and a protrusion formed on the inner surface of the outer cylindrical portion of the seal cap that engages with the protrusion from the flexible tube side. The intravascular indwelling needle according to claim 1. 8. The inner surface of the connector is formed into a female tapered cylindrical surface whose diameter increases toward the end face, and the outer surface of the protrusion of the seal cap is formed into a male tapered cylindrical surface that is liquid-tightly fitted to the female tapered cylindrical surface. An intravascular indwelling needle according to any one of claims 1 to 7. 9. The intravascular indwelling needle according to claim 8, wherein the male tapered cylindrical surface of the protruding portion of the seal cap and the end surface are formed so as to intersect with each other with a non-rounded corner. 10 The inner needle is integrally equipped with a locking part on the outer surface on the side of the cutting edge of the seal cap that comes into contact with the seal cap and prevents the inner needle cutting edge from retreating into the indwelling catheter during puncturing. The intravascular indwelling needle according to any one of Items 1 to 9.