JPH0315915B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a synthetic resin introduction needle used for introducing and indwelling a rod-shaped medical device such as a catheter or guide wire into a blood vessel or the like, and a method for manufacturing the same.

(Prior Art) Conventionally, a flexible introduction needle made of synthetic resin has been used, for example, when introducing and indwelling a catheter into a blood vessel. That is, as shown in FIG. 8, the introduction needle (the same applies hereinafter) 1 is inserted into the inner needle 3 of the syringe 2 with the tip of the inner needle 3 protruding, and then the introduction needle 1 is inserted as shown in FIG. The inner needle 3 is inserted into the blood vessel 4 until the tip of the inner needle 3 is inserted into the blood vessel 4. Next, as shown in FIG. 9, the inner needle 3 is removed from the blood vessel 4 while the introduction needle 1 is kept in that state. With the introduction needle 1 secured in the blood vessel 4 in this way,
As shown in FIG. 10, a desired catheter 5 is inserted through the introduction needle 1, and its distal end is inserted into the blood vessel 4. In this way, the catheter 5 is connected to the blood vessel 4.
After the introduction needle 1 is left in a predetermined position within the blood vessel, it is desirable to remove the unnecessary introduction needle 1 from the blood vessel 4 and also from the catheter 5. This is because it is not sanitary to leave the introduction needle 1, which is no longer needed, removed from the blood vessel 4, and it also interferes with subsequent operations.

However, it is impossible to withdraw the introducer needle 1 from the catheter 5 due to the presence of an enlarged part, such as the connector 6 of the catheter.

Therefore, several proposals have been made for removing the no longer needed introduction needle 1 from the catheter 5. For example, a method has been proposed in which a slit is previously formed along the length of the introducer needle and the unnecessary introducer needle is removed from the catheter through the slit.

In addition, JP-A-56-11069 discloses that a pair of striated bodies made of plastic different from the other parts are formed at radially opposite parts of the introducing needle, and the base of the introduced needle is connected to the striated parts. The fitting part is connected to an inner needle hub with a connected slit, and the unnecessary introducer needle can be divided into two by tearing it from the striated body of the lever with the fitting part. has also been proposed.

(Problems to be Solved by the Invention) However, in the former method of forming a slit in advance, the strength of the introduction needle decreases, making it difficult to operate, and the slit expands when the catheter is introduced into a blood vessel, causing blood leakage. There are problems such as.

In addition, the latter method of forming a heterogeneous striatum tends to cause cracks in the striatum during post-processing such as cutting the introduction needle and processing the tip, or during handling as a product, making it unusable or causing blood leakage. There are problems such as causing

The present invention has been made in view of the above circumstances, and there is no fear of inadvertent peeling or splitting during post-processing or handling as a product, and it is easy to split the catheter from the catheter when it is no longer needed. The purpose of the present invention is to provide a medical device introduction needle and a method for manufacturing the same.

(Means for Solving the Problems) The present invention is a medical device introduction needle for introducing a rod-shaped medical device into a living body, which comprises a synthetic resin hollow tube into which the rod-shaped medical device can be inserted. A part of the hollow tube body is formed of a strip made of a material different from the main part of the hollow tube body over the entire length in the longitudinal direction of the tube body or the entire length in the longitudinal direction excluding the tip end. The present invention attempts to solve the above-mentioned problems by providing a medical device introduction needle characterized in that a weld line is formed approximately in the middle of the body.

It is preferable that the tip of the tubular body is processed so as to come into close contact with the inner needle inserted therein, and that the base is formed into a widened shape. The main part of the hollow tube is made of polypropylene (PP), high-density polyethylene, semi-rigid polyvinyl chloride, fluororesin, etc., and the strip is made of a blend polymer of EVA and PP, for example. , a blend polymer of polyethylene and EVA, etc. are preferably used.

As a means for solving the above-mentioned problems, the present invention further provides a method for manufacturing a medical device introducing needle as described above, in which a molding resin flow path in the vicinity of the discharge opening of the die of an extrusion molding machine is provided. The resin flow for forming the strip is once substantially divided at approximately the middle part of its width by at least one or more diagonal plates disposed, and then merged again and pushed out from the die outlet. The present invention provides a method characterized by molding by extrusion.

In addition, it is preferable that the above-mentioned wall plate is located at a distance of 0 to 5 mm from the end of the discharge port of the die, and its height is 1/2 or more of the height of the resin flow path of the die. Note that in this specification, the weld line refers to a portion where flows of molten resin merge, where fusion is incomplete and the strength is weakened.

(Function) In the medical device introduction needle according to the present invention, the weld line formed on the strip becomes a fragile part for tearing.
After use, it can be easily removed from a medical device such as a catheter via this weld line.

In addition, since a relatively soft strip is formed in a part of the hollow tube body as in the present invention, and a weld line is formed on this strip, physical properties required for this tear portion (for example, divisibility, moldability, etc.)
While it is possible to select a synthetic resin suitable for the material to form the band, it is also possible to select the most suitable synthetic resin for the main part of the hollow tube, which must have sufficient strength as a medical device introduction needle. It becomes possible to select.

(Example) Next, the present invention will be described with reference to an example shown in FIGS. 1 to 5. FIG. 1 is a perspective view of a medical device introduction needle 11 according to the present invention, which is composed of a hollow tube body with openings at both ends into which a rod-shaped medical device such as a catheter can be inserted, and whose tip is tightly attached to an inner needle (not shown). It tapers to a cylindrical shape with an enlarged base.

As shown in FIG. 1 or 2, this tube is made of a material that has physical properties different from the other main parts 12 in a part of the circular arc constituting the tube over the entire length in the longitudinal direction of the tube. A strip 13 is formed, and a weld line 14 is formed along the longitudinal direction approximately in the middle of its width.
is formed. The main part 12 is the introduction needle 11
From the viewpoint of overall operability, it is preferable to use a relatively hard synthetic resin material, such as polypropylene, high-density polyethylene, semi-rigid polyvinyl chloride, poly-4-methylpentene-1, or polycarbonate. The strip 13 is made of a suitable thermoplastic resin material such as polypropylene/ethylene vinyl acetate copolymer, high density polyethylene/ethylene vinyl acetate copolymer, polypropylene/polyethylene, methylpentene polymer/ethylene vinyl acetate copolymer, methylpentene polymer/polyethylene, etc. Blend polymers can be used. This is because if the main part and the striped part are made of completely different resins, cracks will easily occur at the boundary, making post-processing very difficult.
Further, the strip 13 is not limited to the one provided over the entire length of the tube as shown in the figure, but it is also possible to increase the strength of the tip by not providing the strip 13 at the tip. Good too. Also, weld line 1
4 may also be omitted from the tip of the tube to increase the tear strength of the tip.

Although there is no particular restriction on the width of the strip 13, it is generally preferred that the width be less than 1/2 of the arc of the tube. In addition, this strip body 13 can be attached to two parts as needed.
More than one book may be provided.

The weld line 14 is, for example, as shown in FIGS. 4 and 5.
It can be formed using a two-color extrusion molding machine 15 having two cylinders 15a and 15b shown in the figure. In the case of the extrusion molding machine 15, a baffle plate 18 is provided near the discharge portion of the die 17 to protrude from the circumferential surface of the inner mold 19, and blocks the flow of resin from the cylinder 15a for forming the strip 13 at approximately the middle of its width. ing. Therefore, the resin flow forming the strip 13 is divided into large parts when passing through the cutting board 18, and then merged again to form the weld line 14.

The position, height, etc. of this jiyama plate 18 can be determined appropriately depending on the type and composition of the synthetic resin used, but generally the tip position of the jiyama plate 18 and the die 17
The distance L from the tip of the board is 0 to 5 mm, and the
The distance h between the upper end of the resin passage 2 and the inner wall of the outer mold 20 is
When h:H=0 to 1/2:1, preferably 0 to 1/5:1 for a distance H of 1, a weld line 14 having a desired tear strength can be obtained.
Since the bonding force between both sides of this weld line 14 is significantly smaller than the bonding force between the synthetic resins of the other circular arc parts, it is easily destroyed by applying external stress, and is easily destroyed as shown in FIG. 3, for example. It can be torn and thus separated from the catheter 5, for example.

The tear strength of the weld line 14 can be adjusted by adjusting the position, height, width (length, thickness), etc. of the edge plate 18, or by adjusting the type of resin constituting the strip 13 or the combination of two or more resins. This can be done as desired by adjusting the formulation.

Note that as a method for forming the weld line 14,
As shown in FIGS. 4 and 5, a case has been described in which an extruder having a wall plate 18 protruding from an inner mold is used, but the extruder is not limited thereto, and any other molding means may be employed. For example, as shown in FIGS. 6 and 7, the outer mold of the die 17 may be provided with a shank plate 18 similar to that described with reference to FIGS. (all symbols are the same as in Figures 4 and 5), and although not shown, similar board plates may be provided in two or more places on the outer mold or the inner mold, and furthermore, on both the outer mold and the inner mold. They may be provided protrudingly so as to face each other. In either case, the position (L), height (h), size, etc. of the jiyama board are determined by the fourth
Adjustments and selections can be made in the same manner as in the case of FIGS.

Next, a method of using the medical device introduction needle of the present invention will be explained.

First, the introducer needle 11 is inserted into the syringe 2 as shown in FIG. 8 in the same manner as shown in FIGS. 8 to 10, and then the inner needle is inserted into a blood vessel etc. is removed, the introduction needle 11 is secured in a blood vessel, etc., and then a catheter or the like is inserted into the introduction needle 11, and the catheter or the like is introduced into the blood vessel or the like.

Next, when removing the unnecessary introduction needle 11 from the catheter or the like, external stress is applied to the introduction needle 11 to cut the proximal end of the weld line 14 as shown in FIG. The introduction needle 11 can be easily removed from the catheter 5 by tearing it through the catheter 5.

In the above embodiment, the case where a catheter is introduced as a medical device introduction needle has been described, but it goes without saying that the present invention is applicable not only to catheters but also to cases where all kinds of rod-shaped medical devices are introduced into the human body.

(Effects of the Invention) As detailed above, the medical device introduction needle according to the present invention has a striated body made of a different synthetic resin at the tearing part of the introduction needle, so that the operability of the introduction needle as a whole is improved. It is possible to use materials for the main part of the introducer needle that optimize the
By selecting an appropriate material of different nature for the strip, it is possible to provide the tearing portion of the introduction needle with the necessary functions such as excessive divisibility.

Example 1 A pair of jamb plates with a length of 22 mm and a width of 0.5 mm were placed in contact with the inner wall of the die of a two-color extrusion molding machine as shown in Fig. 7, and their tips were placed at the outlet of the die. It was placed so that it came 0.5 mm from the front (ie, "L" = 0.5 mm in Fig. 7). Next, the polypropylene is flowed into the cylinder 15b for forming the main part of the pipe body, and a mixture of polypropylene (PP) and ethylene vinyl acetate copolymer (EVA) (mixing ratio, PP: EVA=80~90:20~
10) to obtain a catheter introduction needle compatible with a 16G inner needle. Even when the tip was machined so that it was in close contact with a 16G inner needle, there were no problems such as the tip breaking. Furthermore, even when the inner needle was inserted into the blood vessel of a mongrel dog, the tip did not curl or crack, and when it was attempted to be divided at the time of removal, it was easily divided.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a medical device introduction needle according to the present invention, FIG. 2 is a sectional view taken along the line - in FIG. 1, and FIG. 3 is a perspective view showing the introduction needle of FIG. 1 in a torn state. 4 is a front view of the introduction needle manufacturing device shown in FIG. 1, FIG. 5 is a sectional view of the manufacturing device shown in FIG. 4,
FIG. 6 is a front view of another manufacturing device for the introducer needle of the present invention, FIG. 7 is a cross-sectional view of the manufacturing device shown in FIG. 6, and FIGS. 8 to 10 show how the medical device introducer needle is used. It is a schematic diagram for explanation. 1...Introduction tube body, 2...Syringe, 3
...inner needle, 4...blood vessel, 5...catheter, 6...
... Connector, 11 ... Medical device introduction needle, 12 ...
Main part of pipe body, 13... Strip body, 14... Weld line, 15... Extrusion molding machine, 15a, 15b
... cylinder, 17 ... die, 18 ... wall board, 19 ... inner mold, 20 ... outer mold, 21 ... resin passage.

Claims (1)

[Scope of Claims] 1. A medical device introduction needle for introducing a rod-shaped medical device into a living body, which is made of a hollow tubular body made of synthetic resin into which the rod-shaped medical device can be inserted, and which has a longitudinal axis of the tubular body. At least a part of the hollow tube over the entire length in the direction or the entire length in the longitudinal direction excluding the tip end is formed from a strip made of a material different from the other parts of the hollow tube,
A needle for introducing a medical device, characterized in that a weld line is formed approximately in the middle of the strip by joining with a relatively weak force. 2. The medical device introduction needle according to claim 1, wherein the tip of the tubular body is processed so as to come into close contact with an inner needle inserted through the tubular body, and the base has a widened shape. 3. The needle for introducing a medical device according to claim 1, wherein a pair of the strips are provided so as to face each other in the radial direction. 4. The main part of the hollow tube is made of polypropylene, polyethylene or poly-4-methylpentene-1, and the strip is made of polypropylene/ethylene vinyl acetate copolymer, polypropylene/polyethylene, polyethylene/ethylene vinyl acetate copolymer, methyl A needle for introducing a medical device according to claim 1, which is formed from a pentene polymer/ethylene vinyl acetate copolymer or a methylpentene polymer/polyethylene. 5. A medical device introduction needle for introducing a rod-shaped medical device into a living body, which consists of a hollow tube made of synthetic resin into which the rod-shaped medical device can be inserted, excluding the entire longitudinal length of the tube or the tip. At least a part of the hollow tube over the entire length in the longitudinal direction is formed from a strip made of a material different from other parts of the hollow tube, and a weld line is formed approximately in the middle of the strip. A method for manufacturing a needle for introducing a medical device, characterized in that at least one or more of the molding resin flow path near the outlet of the die of the extrusion molding machine is disposed near the outlet of the die. The method is characterized in that the resin flow for forming the strip is substantially divided at approximately the midpoint of its width by a jamb plate, then merged again, and then extruded from the die outlet to form the resin flow. A method for manufacturing a needle for introducing a medical device. 6. The method according to claim 5, wherein the cutting board is positioned such that the tip of the cutting board is 0 to 5 mm from the end of the outlet of the die. 7. Claim 5 or 6 in which the height of the cutting board is 1/2 or more of the height of the resin flow path of the die.
The method described in section.