JPH03292963A - Easy splittable cannula - Google Patents

Abstract

PURPOSE:To provide an easy splittable cannula generating no leakage of blood and having proper tear strength by constituting a tube made of a synthetic resin of a plurality of strip bodies extending in the longitudinal direction of the tube and making the strip bodies adjacent to each other easily separable. CONSTITUTION:A tube made of a synthetic resin is constituted of mutually adjacent strip bodies easily separable from each other. One strip body 2 among them is made of the first synthetic resin and the other adjacent strip body 3 is pref. prepared from a material composed of a mixture consisting of the first synthetic resin and the second synthetic resin having no affinity for the first synthetic resin and, when grip parts 5, 6 are grasped by the hand and pulled in the direction right-angled to the longitudinal axis of the tube so as to separate both strip bodies, a cannula 1 is easily torn at the part of a boundary 4 to be separated into the first and second strip bodies 2, 3. Since the mutual adhesive strength of the strip bodies of the cannula 1 is proper, it is prevented that the cannula 1 is broken during puncture and a punctured region is damaged when the cannula 1 is detached and a catheter can safely be introduced into the body cavity of a patient.

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a cannula used as an introduction part of a catheter. This invention relates to an easily split cannula that can be easily removed by tearing the cannula in the longitudinal direction.

<Prior art> A synthetic resin cannula called an indwelling needle functions as an introduction part for smoothly introducing a long catheter, etc. into a body cavity. Its presence interferes with subsequent procedures. Therefore, a type of synthetic resin cannula that can be removed by tearing or splitting the cannula as an introduction part lengthwise after insertion of the catheter has been developed (Japanese Utility Model Publication No. 51-1661, Japanese Patent Publication No. 61 −
No. 59146, No. 61-50464, Japanese Patent Publication No. 2-7670, etc.).

The invention disclosed in Japanese Utility Model Publication No. 51-1661 involves grasping the handle means and applying force in a direction perpendicular to the longitudinal axis to open the indwelling needle along the weakened part of the separation line (multiple slits or perforations). It was designed as
The invention disclosed in Japanese Patent Publication No. 2-7670 discloses a catheter formed of a material in which a base polymer is uniformly mixed with a modified polymer that is incompatible with the base polymer (which easily tears in the longitudinal direction). The invention is a catheter in which two parallel striated bands made of a modified polymer disclosed in Japanese Patent Publication No. 61-59146 are interposed at positions approximately 180 degrees apart. Further, the invention disclosed in Japanese Patent Publication No. 61-50464 provides a plurality of striated portions mixed with inorganic powder having X-ray contrast properties along the axial direction of the base body of the catheter.

However, these conventional techniques, for example,
The device disclosed in Publication No. 1-1661 has the fatal drawback that the blood that flows in during puncture leaks out from the separation line, and it is not only extremely painful, but also has the possibility of being torn into pieces during tearing. There are also inventions of Japanese Patent Publication No. 61-59146 and Japanese Patent Publication No. 2-7670 that utilize modified polymers, and inventions of Japanese Patent Publication No. 61-50.
The invention disclosed in Japanese Patent No. 464 has the disadvantage that the tear strength is still too high, and when a large force is applied to remove the cannula, the cannula may move and cause pain to the patient.

<Problems to be Solved by the Invention> The present invention was made in view of the above circumstances, and an object thereof is to provide an easily split cannula that does not cause blood leakage and has appropriate tear strength.

<Means for Solving the Problems> In order to solve the above problems, the present invention provides a synthetic resin tube composed of a plurality of longitudinally extending strips, in which adjacent strips can be easily connected to each other. It uses a cannula that can be separated into two parts.

<Function> Since the cannula of the present invention is constructed as described above, the adhesive strength at the bonded portion between the bands is weak, and the cannula easily tears at the boundary between the bands.

<Example> Next, examples of the present invention will be described.

The cannula of the present invention is a synthetic resin tube composed of a plurality of longitudinally extending strips, and adjacent strips can be easily separated from each other. Adjacent strips may be formed using any material as long as they can be easily separated, but one of the adjacent strips is made of the first synthetic resin, and the adjacent strips are made of the first synthetic resin. The other one is preferably made of a material made by mixing a first synthetic resin with a second synthetic resin that is incompatible with the first synthetic resin, and the first synthetic resin is polypropylene or polyethylene. ,
Polyester or the like can be used, and polyurethane can be used as the second synthetic resin, and a combination of polypropylene and polyurethane is particularly preferred. In the case of a combination of polypropylene and polyurethane, the mixing ratio is approximately 65 to 9.
5ht%: 35 to 5wt%. Incidentally, one side of the band may be mixed with a pigment or an inorganic powder having XM contrast properties such as barium sulfate, tungsten carbide, or zirconium oxide, and the base of the cannula may be filled with a suitable grip such as a wing-shaped tab. A means may be provided.

Next, the operation of tearing the cannula of the present invention will be explained using the drawings (FIG. 1).

In FIG. 1, (1) is a cannula, (2) is a band made of a first synthetic resin, and (3) is a band made of a mixture of the first synthetic resin and the second synthetic resin. body,
(4) is the boundary between strips (2) and (3), (5) and (6
) is the grip part.

When gripping parts (5) and (6) are grasped by hand and pulled in a direction perpendicular to the longitudinal axis in a direction that separates (5) and (6), the cannula (1) can be easily removed at the boundary (3). The strips (2) and (3) are separated.

[Examples 1 to 5] Two extrusion molding machines (manufactured by Plastic Engineering Research Institute Co., Ltd.,
Using UT25H, UT32H), one molding machine was filled with polypropylene, and the other molding machine was filled with polypropylene and polyurethane at a weight ratio of 95wt%:5wt%, 9 (
IHt%: 10wt%, 80wt%: 20wt%, 70
A mixture of 11t%:30wt% and 65wt%:35wt% was filled, and a tube consisting of two strips was manufactured using these two molding machines. And about the obtained tube (outer diameter 2.1 m, inner diameter 1.75!Im),
Tear strength was measured using Tensile Test II (manufactured by Shimadzu Corporation, S-500) in the following manner. That is, 20 slits were provided at the base end of a tube having a total length of 70 mm, and the grip part was attached to a tensile testing machine in the state shown in FIG. 1, and the force required for tearing was measured. The results are shown in Table 1. The tear strength was 0.1 to 0.3 kg, which was an appropriate strength, and the cannula did not break during cannula puncture, and the cannula puncture area was not damaged when the cannula was removed.

[Comparative Example 1] Polyurethane and a mixture of polyurethane and polypropylene at a ratio of 80wt%:20iit% were prepared, similar tubes were manufactured using the same molding machine as in Examples 1 to 5, and similar tests were conducted. went.

The results are shown in Table 1.

[Comparative Example 2] Polypropylene and a mixture of polypropylene and polyurethane at a ratio of 40wt%:60wt% were prepared, and a similar tube was manufactured using the same molding machine as in Comparative Example 1, and the same test was conducted. . The results are shown in Table 1.

[Comparative Example 3] Polypropylene and a mixture of polypropylene and polyethylene at a ratio of 20wt%:80wt% were prepared, and the same tube was manufactured using the same molding machine as Comparative Example 1, and the same test was conducted. . The results are shown in Table 1.

<Effects of the Invention> As is clear from the above explanation, since the cannula of the present invention has an appropriate adhesive strength between the band members, the cannula does not break off during cannula puncture, and the cannula cannot be removed. The catheter can be safely introduced into the patient's body cavity without damaging the puncture site.

(Omitted below)

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating the operation of tearing the cannula of the present invention. <Explanation of symbols> Cannula 2: First band 3: Second band 4: Boundary 5.6: Grip

Claims (1)

[Scope of Claims] 1) A synthetic resin tube composed of a plurality of longitudinally extending strips, which is easily separable, characterized in that adjacent strips can be easily separated from each other. cannula. 2) One of the adjacent strips is made of a first synthetic resin, and the other of the adjacent strips is made of a mixture of the first synthetic resin and a second synthetic resin that is incompatible with the resin. 2. The cannula of claim 1, wherein the cannula is made of a material comprising: 3) The cannula according to claim 2, wherein the first synthetic resin is polypropylene and the second synthetic resin is polyurethane. 4) Mixing ratio of polypropylene and polyurethane is 65~
The cannula according to claim 3, wherein the content is 95 wt%: 35 to 5 wt%. 5) The cannula according to any one of claims 2 to 4, wherein one of the bands is mixed with a pigment or a powder having an X-ray contrast. 6) Claims 1 to 5, wherein a gripping means is provided at the base of the cannula.
The cannula described in any of the above.