JPH02177966A - Tube for introducing medical instrument and method and device for molding this tube - Google Patents

Abstract

PURPOSE:To obtain the tube for introducing medical instruments which is easily detachable from the medical instruments and can be inexpensively produced by forming the tube which has a tubular body consisting of the same material and is formed with filamentous discontinuous parts by the imperfect welding at the time of molding of the tubular body in the longitudinal direction of the tubular body. CONSTITUTION:The tube 1 for introducing the medical instruments is formed with the filamentous discontinuous parts 3 in the positions symmetrical with the center line of the tube body 2. Divided junctures 4, 4 are fixed to the end side of the tube body 2. Expanded bore parts 4a, 4a which are expanded in the bores are formed to the rear end side of the junctures 4, 4. The tip of a syringe 6 is inserted into the expanded bore parts 4a, 4a of the tube 1 and an injection needle 7 is inserted into the tube body 2, then the needle 7 is introduced together with the tube body 2 into the blood vessel 8. The syringe 6 is removed together with the needle 7 from the tube 1 and a catheter 5 is inserted into the tube 1. The front end side of the catheter 5 projects from the tube body 2 into the blood vessel 8. The tube 1 is removed from the vessel 8 while the junctures 4, 4 are opened. The tube body 2 is torn along the discontinuous parts 3 and the tube 1 can be easily removed from the catheter 5 and the vessel 8.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a tube for introducing medical instruments, a method for molding the same, and a molding device for the same.

BACKGROUND OF THE INVENTION In the prior art, a detentable plastic tube called a catheter is used to drain the contents of a patient's tubular organ or to inject liquid nutrients or drugs into the tubular organ.

For example, the following methods have been conventionally used to introduce the distal end of a catheter into a blood vessel.

As shown in FIG. 18, the syringe 6 is attached to the tube 51 and the injection needle 7 is exposed from the tip of the tube. In this state, the injection needle 7 is inserted into the blood vessel 8 (see FIG. 19). As shown in FIG. 19, the syringe 6 is removed from the tube 51. Thereafter, the catheter 5 (see FIG. 21) is immediately inserted into the tube 51, and the distal end of the catheter 5 is introduced into the blood vessel 8 as shown in FIG. In this way, liquid nutrients or medicines are injected into the blood vessel 8 via the catheter 5, but the tube 51 is not only unnecessary after the time shown in FIG. This poses a problem and may interfere with subsequent medical treatment. Therefore, the duplex must be removed from the blood vessel after catheterization into the blood vessel.

However, the catheter is provided with a large-diameter portion (for example, a connector) 5a (see Fig. 21) at the rear end for connection with other medical equipment, and this large-diameter portion may get in the way and make it difficult to pull out the tube. Can not.

Under these circumstances, proposals have already been made to remove the tube while the catheter is introduced into the blood vessel.

Among these, the most recent proposal is JP-A No. 62-176459.
There is a number. This tube is formed by removably embedding a plastic filament having little compatibility with the tube body in the longitudinal direction of the plastic tube body wall. FIG. 17 is an enlarged sectional view of the tube.

A striatum 53 with little compatibility within the wall 52 of the tube 51
is embedded to form the tube 51.

FIG. 20 shows how to remove the tube from the catheter. By pinching the end of the tube with fingers, the filament 53 easily comes off the tube wall 52 and exits to the outside. When this detached portion of the filament 53 is pulled with a finger, the filament 53 separates from the tube wall 52 while tearing the tube wall 52, and the catheter 5 is exposed. When the tube wall 52 is thus removed from the catheter 5 while being torn, only the catheter 5 is introduced into the blood vessel 8, as shown in FIG.

However, since the above-mentioned tube is made of two types of materials, two types of molding materials must be prepared, and the structure of the molding machine (for example, an extrusion molding machine) is complicated to form the filament. This increases manufacturing costs.

In addition to the above-mentioned tube, Japanese Patent Application Laid-open No. 59-91967 discloses that a tube is irradiated with lll1! A method of forming a weakened portion in a linear shape is disclosed. However, this method requires investment in equipment for radiation irradiation, and furthermore, irradiation of radiation to a narrow region in the longitudinal direction of a small-diameter tube is accompanied by considerable difficulty in accuracy.

C1 Purpose of the Invention The present invention can be easily detached from a medical device (for example, a catheter), does not require the preparation of multiple types of molding materials, does not complicate the structure of a molding machine, and has a radiation irradiation device, etc. It is an object of the present invention to provide a tube for introducing a medical device, a method for molding the same, and a molding device for the same, which can be manufactured at low cost without requiring other equipment.

26 Structure of the Invention The first invention comprises a tubular body made of substantially the same material, and a linear discontinuous portion is formed in the longitudinal direction of the tubular body due to incomplete fusion during molding of the tubular body. This relates to tubes for introducing medical devices.

The medical device introduction tube may have either a structure having the tubular body on one end side or a structure in which the entire tube portion is made of the tubular body. In addition, the above discontinuous part is
Although it is preferable that the discontinuous portion is formed over the entire length of the tubular body in the longitudinal direction, it is sufficient that the discontinuous portion is formed in the longitudinal direction with a length that allows the discontinuous portion to be sufficiently split.

In a second invention, when molding a tube for introducing a medical device, the flow of the molding material is disrupted at at least one location in the molding die, thereby making the fusion of the molding material incomplete and extending the tube in the longitudinal direction. The present invention relates to a method of forming a tube for introducing a medical device according to the first invention, which forms a linear discontinuous portion.

A third aspect of the invention is to control the temperature distribution of the molding die when molding a tube for introducing a medical device, thereby making the fusion of the molding material incomplete and forming a linear discontinuous portion in the longitudinal direction of the tube. The present invention relates to a method of forming a tube for introducing a medical device according to the first invention.

A fourth invention is a tube forming apparatus in which a molding material circulation space is formed between a hollow outer die and an inner die located within the outer die, in which the molding material is disposed in at least one place in the molding material circulation space. This relates to a molding device for a tube for introducing a medical device, which is used in the molding method according to the second invention, characterized in that a turbulence means for disrupting the flow of the medical device is provided.

A fifth invention is a tube forming apparatus in which a molding material circulation space is formed between a hollow outer die and an inner die located within the outer die, and an inner die for supporting the inner die on the outer die. A die support member is provided and the length of the outer die is such that molding material divided by the inner die support member exits the outer die before it is fully fused downstream of the inner die support member. The present invention relates to a molding device for a tube for introducing a medical device, which is used in the molding method according to the third invention, and is characterized in that a diameter is set.

E, Example The present invention will be explained in detail below.

FIG. 1 is a front view of a tube for introducing a medical device (catheter in this example) (hereinafter simply referred to as a tube), and FIG. 2 is an enlarged cross-sectional view taken along the line ■-■ in FIG.

The tube 1 is centered over the entire length of the plastic tube body 2! Two linear discontinuous portions 3 (details will be explained later with reference to FIG. 3) are formed at two locations symmetrical to a (not shown). Connection parts 4, 4, which are divided along the discontinuous part 3, are fixed to one end side (rear end side) of the tube body 2 so as to surround the tube body 2. Enlarged-diameter portions 4a, 4a whose inner diameters are enlarged are formed on the rear end sides of the connecting portions 4, 4 for fitting and connecting a syringe (not shown).

The tube body 2 has an outer diameter of 1.6 mm, an inner diameter of 1.3 mm, and a length of 57 mm. Materials for the tube body 2 include polypropylene, polyethylene, polyvinyl chloride,
Polystyrene, polycarbonate, polyester, polyamide, polyvinyl acetate, polyurethane and other geothermoplastic resins are used. In this example, the tube body 2 is made of polypropylene.

FIG. 3 is a sketch of an electron microscope structure (200x magnification) showing the cross-sectional structure of the discontinuous portion 3 of the tube body 2 and its surroundings. A discontinuous portion 3 is formed in the tube body by a crack 3a. The cracks 3a are formed because the molten molding material flowing inside the die cavity during molding is once separated by a thick-walled spider, which will be described later, and is incompletely fused at the point where it joins downstream of the spider. . The tube body can be easily torn along the crack since the crack is formed in a linear shape in the longitudinal direction of the tube body. This crack is not formed over the inner and outer peripheral surfaces of the tube body, and in FIG. 3, a portion 3b that appears to be completely fused is observed on the inner peripheral side.

However, this part 3 that appears to be completely fused
It can be said that b also has a discontinuous part on a microscopic level at the molecular level. This is evidenced by the fact that even in tube bodies where no cracks are observed, the tube bodies are easy to tear along locations corresponding to the locations of said thick-walled spiders.

Next, a procedure for introducing a catheter into a blood vessel using a tube will be explained with reference to FIGS. 4 to 7.

First, connect the tube 1 at the connecting portion 4. in the same manner as shown in FIG.
Insert the tip of the syringe 6 into the enlarged diameter parts 4a, 4a of 4,
Insert the injection needle 7 into the tube body 2. In this state, the distal end side of the injection needle 7 protrudes from the distal end of the tube body 2 and is exposed. FIG. 4 shows the injection needle 7 introduced into the blood vessel 8 together with the tube body 2 as described above.

Next, insert the syringe 6 into the injection needle 7 in the same manner as shown in FIG.
At the same time, the catheter 5 is pulled out from the tube 1, and the catheter 5 is immediately inserted through the tube 1 as shown in FIG. In this state, the distal end side of the catheter 5 protrudes from the tube body 2 into the blood vessel 8.

Next, as shown in FIG. 6, the protruding piece 4b of the connecting portion 4.4
, 4b, and pull out the tube 1 from the blood vessel 8 while opening the connecting parts 4, 4 (.In this way, the tube body 2 is stretched over the connecting part 4. Because it is torn, the large diameter portion 5 on the rear end side of the catheter 5
The tube 1 can be easily removed from the catheter 5 and blood vessel 8 without being obstructed by a.

FIG. 7 shows that only the catheter 5 is connected to the blood vessel 8 as described above.
This shows the state in which it has been installed. In the state shown in Figure 7,
A liquid conduit 9 is connected to the large-diameter portion 5a of the catheter, and a predetermined liquid substance (nutrient and/or one drug) is administered to the patient.

Needless to say, the liquid conduit may be connected to the catheter in advance, and the tube 1 may be removed in the same manner as shown in FIG. 6 after the catheter is introduced.

The tube is formed by extrusion.

Hereinafter, a tube forming method and a forming apparatus will be explained.

FIG. 11 is a schematic cross-sectional view of the extrusion molding machine. cylinder 2
The screw 23 in the drive shaft 2 is rotatably supported by a thrust bearing 24 and rotated by a reduction gear 25 .

The molten molding material supplied from the hopper 26 is sent to the left in the figure by the rotation of the screw 23, and is
Foreign matter is filtered through the breaker plate 20 of 00 Menosier, and the die structure 10 is attached to the head part 21.
and is discharged from the die structure 10 to form a tube. In the figure, 27 is a heater, 28 is a lubrication system, and 29 is a cylinder cooling water circulation unit F.

FIG. 9 is an enlarged sectional view of the head structure 10, and FIG. 10 is a sectional view taken along the line X--X in FIG.

The die structure 10 includes a die body 11, a torpedo 12,
A mandrel (inner die) 15 connected to the torpedo and an outer die 14 are assembled, and the outer die 1
4 consists of an upstream section 14a and a downstream section 14b. The torpedo 12 and the mandrel 15 are connected to a plurality of spiders 1
Die body 11 and outer die 14 by 3A and 13B
It is supported by the upstream portion 14a of. An air inlet 19 is provided that penetrates the die body 11, one of the sub-idas 13B, and the torpedo 12, and opens into the mandrel 15, and the pressure inside the tube discharged from the die structure is reduced to deform the tube. I am trying to prevent this. In the figure,
16 is a bolt for adjusting the position of the downstream part 14b of the outer die; 17
A and 17B are heaters, and 18 is a blind hole into which a temperature regulating thermocouple is inserted. The melt-molded material 47 (indicated by an arrow) introduced into the die structure 10 is made into an annular shape by the torpedo 12, passes through the annular cavity 1Oa between the outer die 14 and the mandrel 15, and is formed into a tube shape. After that, it becomes completely solidified by cooling.

The melt-molded material 47 is once divided when passing through the spiders 13A and 13E3, but merges within the cavity 10a and is fused to become uniform. The cross-sectional area of the cavity 10a decreases as it goes toward the front, so that the melt-molded material is pressurized and this fusion is promoted. In order to perfect this fusion, the spiders are usually streamlined so as not to disturb the flow of the melt molding material 47 as much as possible, but what is unique about this example is that they are placed at symmetrical positions. Only Spider 13813 days is that thick. (The spider 13A has a normal spider shape.

FIG. 8A is an enlarged sectional view of the spider 13A, and FIG. 8B is an enlarged sectional view of the spider 13B.

The length l of the spider is 5 mm for both 13A and 13B, and the thickness of the spider is 13A's tl is 2mm, 13B's t2 is 3.5@-, and the spider 13th is thicker than spider 13A. It is.

In the spider 13A, the flow of the melted molding material is not significantly disturbed, and the molding materials that merge downstream thereof are completely fused and no discontinuous portion is formed. In spider 13B, the f line is slightly distorted, so the flow of the melted molding material is disturbed, and the molding materials that merge downstream are not completely fused, resulting in a discontinuity (Fig. 1, 3) in Figure 2 is formed in a linear shape. The tube discharged from the die structure 10 is not completely solidified, but is completely solidified through air cooling and water cooling steps. The thickness of the spider 13B is increased as described above (in addition, the thickness t is increased as shown in FIG. 8C).
l is the normal thickness 21, and the length! By using the spider 13C in which 22 was lengthened to 10 stitches, it was possible to form a linear discontinuous portion in the same manner as above. Spider 13E
3, it goes without saying that both the thickness and length may be larger than the normal dimensions.

In addition to varying the dimensions of the spider as described above to create a linear discontinuity at the location of the tube corresponding to this spider, the temperature of the die is lower than normal to create a similar discontinuity in the tube. can be formed. That is, the spiders are provided at three locations as normal spiders 13A, and the temperature control device TC controls the power supplied to the heaters 17A and 17 in FIG. The temperature of the mandrel 15 and the downstream part 14b of the outer die is set to be 5 to 20°C lower than the normal temperature of 140°C. In this way, the aforementioned fusion was made incomplete downstream of the three spiders (normal spider 13A). As a result, three linear discontinuous portions similar to those described above were formed in the obtained tube.

The discontinuous portion can also be formed by locally cooling the outer die from the surrounding area with cooling water, or by locally reducing the wall thickness of the outer die.

By controlling the die temperature as described above, it is possible to form linear discontinuities in the tube.
In addition to the above temperature control, the die structure is
A structure like 3- is preferable because the discontinuous portion is stably formed.

In the die structure shown in FIG. 9, the length 13 of the outer die 14 is 50 mm, whereas in the die structure shown in FIG. It's shortened in half. In this way, the molding material is ejected from the die structure just before the aforementioned fusion is performed and is cooled to more consistently form the filament-like discontinuities in the tube.

In addition to the above, the die structure shown in FIG. 9 is used, and as shown in an enlarged view in FIG.
A is provided at a position downstream of the spider. As a result, the molecular arrangement of the molding material is changed just before the molding material is fused by the protrusion 15a. In other words, a plastic molecule with long chains of atoms has protrusions 15
In the region where a does not exist, they are arranged along the longitudinal direction of the tube, but at the location of the protrusion 15a, the chain-like atomic arrangement is divided by the protrusion 15a in a direction intersecting the longitudinal direction of the tube. The molding material is then directly discharged from the die structure, cooled and solidified. Therefore, the protrusion 15
A discontinuous portion in which the molecular arrangement is disturbed at a position corresponding to a is formed in a linear shape in the longitudinal direction of the tube. The protrusion dimension of the protrusion tSa is a predetermined dimension (for example, about 3/4 to 1/4) with respect to the radial dimension of the cavity 10a at this position.
It's fine if you do this.

The protrusion 15a can move forward and backward, and the protrusion 15a is moved into the cavity tOa only when molding one end of the tube.
The linear discontinuous portion is formed so as to protrude from the tube, and this end side can be the rear end side of the tube. In this case, in the process shown in Fig. 6, the tube is torn along the discontinuous portion on the rear end side, and thereafter, the portion of the tube without the discontinuous portion is torn along the extension line of the discontinuous portion (.

This prevents the tube from being inadvertently torn before use due to insufficient mechanical strength when not in use.

In the die structure shown in FIGS. 12 and 13, it is possible to form a linear discontinuous portion in the molded tube even when the die temperature is a normal temperature.

In addition, a protrusion 1 similar to that shown in FIG. 13 is attached to the die structure shown in FIG. 12.
5a may be provided, and it goes without saying that the die temperature may be controlled as described above.

Since the tube bodies are made of the same material, there is no need to supply another second molding material to the die structure, and the structure of the die structure does not become complicated.

Additionally, the die structures shown in Figures 9, 10, 12, and 13 can all be manufactured by making slight modifications to the conventionally used die structures, thereby eliminating the need for increased equipment costs. tubes can be manufactured at low cost.

The tube is attached to the syringe connection connection part 4 shown in FIG.
4 separately and fixed to the tube body 2, or as shown in FIG. 14, the tube 31 may be formed by connecting to the tube body 31a and integrally molding the expanded diameter part 31b for syringe connection. The discontinuous portion 33 is the tube 3
1 over the entire longitudinal direction. Such tubes with different diameters can be obtained by heating one end of a large-diameter tube having a discontinuous portion, then melting and drawing it.

It can also be obtained by changing the take-up speed of the tube during extrusion molding to form tubes with different diameters that are corrugated in the longitudinal direction, and then cutting the tubes as appropriate.

FIG. 15 and FIG. 16 show a tube molding method by injection molding and a tube molded by this method.

The tube main body 41a shown in an enlarged view in FIG. 16 is formed by extrusion molding, and the rear end portion 41b is integrally formed with the tube main body 41a by insert molding. In addition,
In this example, no discontinuous portion is formed in the tube main body 41a, and a linear discontinuous portion 43 is formed only in the rear end portion 41b.

FIG. 15 is a schematic sectional view of the main parts of the injection molding apparatus. Separable outer dies 44A, 44B and, for example, an inner die 45 with a draft angle are placed.

The duplex main body 41a shown in FIG. 16 is inserted into a die. In the cavity 46 formed by each die,
The molten molding material 47 is press-fitted by injection via the spool 44b. By lowering the temperature of the melt molding material 47 (160'C in this example), a discontinuous portion (called a weld line) 43 (called a weld line) where the molding material is not completely fused to the opposite side of the spool 44b is created. (indicated by phantom lines) is formed.

After waiting for the molding material 47 to cool and solidify, the outer dies 44A and 44B are divided, the solidified molding material is extracted from the inner die 45, and the portion corresponding to the spool 44b is cut and removed. In this way, the rear end portion 41b in which the linear discontinuous portion 43 due to the weld line is formed is the tube body 4.
1a, and is formed integrally with the tube 41 of FIG.
is obtained.

The syringe connection connection part 4 shown in FIG. 1 is attached to the rear end 41b.
．． Fix 4 to make the finished product. The rear end portion 41b opens along the discontinuous portion 43 in the same manner as shown in FIG.
Further, along the extension line of the discontinuous portion 43, the tube body 4ta
is opening. (Thus, the tube 41 can be easily removed from the catheter.The rear end 41b has an enlarged diameter part for connecting a syringe (corresponding to 31b in FIG. 14) similar to that shown in FIG. 14.
The connecting portions 4, 4 can be omitted.

The present invention has been described in detail above using an example of introducing a catheter into a blood vessel, but the present invention can also be applied to introducing a medical tubular device such as a bypass tube into a blood vessel in addition to a catheter. The present invention is also applicable to introducing medical tubular or linear instruments into tubular organs or body cavities other than blood vessels. In these cases, the dimensions, structure, and material of the introduction tube are appropriately set depending on the purpose.

1. Effects of the Invention The medical device introduction tube according to the present invention has linear discontinuities formed in the longitudinal direction due to incomplete fusion in the tubular body made of substantially the same material. There is no need to use a molding material, and the discontinuous portion can be formed in the tubular body by making slight modifications to the conventional molding die or by controlling the temperature of the molding die during molding. Moreover, by separating the tubular body at the discontinuity after introducing the medical instrument, the tubular body can be removed from the medical instrument, and medical procedures can be performed easily and safely.

[Brief explanation of the drawing]

1 to 16 show embodiments of the present invention. FIG. 1 is a front view of a medical device introduction tube (hereinafter simply referred to as a tube), and FIG. An enlarged cross-sectional view taken along the line nn, FIG. 3 shows the structure of the tube, and the electron microscopic Mi weave sketches, 4, 5, 6, and 7 of the discontinuous portion and its surroundings are shown.
The figure is a front view showing the procedure for introducing a catheter into a blood vessel using a tube (some parts are cross-sections), Figures 8A, 88, and 8C are enlarged cross-sectional views of the spider, and Figure 9 is a die. FIG. 10 is an enlarged sectional view of the structure, FIG. 10 is a sectional view taken along the line X-X in FIG. 9, FIG. 11 is a schematic sectional view of an extrusion molding machine, and FIG. 12 is an enlarged sectional view of a die structure according to another example. Fig. 13 is an enlarged partial sectional view of a die structure according to another example, Fig. 14 is a front view of a tube according to another example, Fig. 15 is a schematic sectional view of main parts of an injection molding device, and Fig. 16 FIG. 2 is an enlarged perspective view of a tube formed by injection molding. Fig. 17 to Fig. 21 show conventional examples, Fig. 17 is an enlarged sectional view of the tube, Fig. 18, Fig. 19, Fig. 20, and Fig. 21 show the procedure for introducing the catheter into the blood vessel. Fig. 2 is a front view (partially shown in cross section) showing. In addition, in the symbols shown in the drawings, 1.31.41...tube 2.31a, 41a...tube body 33.43
... Discontinuity ... Crack ... Connection part (increased diameter part) ... Catheter ... Catheter large diameter part ... Syringe ... Injection needle ...・Vessel 0...Die structure 2...Torpedo 3A, 13El
, 13C...Spider 4.34.44A, 44B...Outer die...Inner die...Protrusion...Heater...Melting molding material...Temperature control device 15. 35.45 5a 17A, 17E1 C. Figure 1 Figure 3 Agent Patent Attorney Hiroshi Aisaka Figure 8A Figure 8B Figure 8C Figure Tsutomu Figure 10 Figure 13 Figure 17 Figure 18 Figure 20 Figure 14 S1 Figure 16

Claims (1)

[Claims] 1. A tubular body made of substantially the same material, and a linear discontinuous portion due to incomplete fusion during molding of the tubular body is formed in the longitudinal direction of the tubular body. Tube for introducing medical equipment. 2. When molding a medical device introduction tube, by disrupting the flow of the molding material at at least one location in the molding die, the fusion of the molding material is incomplete and a linear pattern is formed in the longitudinal direction of the tube. A method of forming a tube for introducing a medical device to form a discontinuous portion. 3. When molding a tube for introducing a medical device, by controlling the temperature distribution of the molding die, the fusion of the molding material is made incomplete and a linear discontinuous portion is formed in the longitudinal direction of the tube; A method for forming tubes for introducing medical devices. 4. In a tube molding device in which a molding material flow space is formed between a hollow outer die and an inner die located within the outer die, the flow of the molding material is disturbed in at least one part of the molding material flow space. 1. A device for forming a tube for introducing a medical device, characterized in that a turbulence means is provided for the purpose of turbulence. 5. In a tube forming apparatus in which a molding material circulation space is formed between a hollow outer die and an inner die located within the outer die, an inner die support member for supporting the inner die on the outer die is provided. The length of the outer die is set such that the molding material separated by the inner support member is discharged from the outer die before it is completely fused downstream of the inner die support member. A device for forming tubes for introducing medical devices, characterized by: