JP2759305B2 - Medical tubing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conduit used for introducing a liquid or the like into or out of an animal, especially a human body, and for dilating a blood vessel, removing a thrombus or emboli. Tubes, artificial blood vessels, artificial trachea, etc. used for
That is, catheters, cannula, cannula, used for the purpose of inspection, observation, prevention, treatment, etc. of diseases and the like.
It relates to bougies and other medical tubes.

[0002]

2. Description of the Related Art For example, medical tubes are inserted into blood vessels (particularly coronary arteries), trachea, fallopian tubes, ureters, and various other organs to inject, inhale, or channel liquids. It is used for the purpose of ensuring patency.
Recent catheters have become multifunctional with the progress of medical technology, in addition to the above-mentioned normal functions, including illumination fibers and image guides for endoscopes, and even those with flash holes. U.S. Pat. No. 4,846,812 proposes a cannula using a shape memory resin.

[0003] By the way, when a medical tube is inserted, placed, or removed from the body, the patient feels uncomfortable, and in some cases, suffers from pain or suffering. The above situations are collectively referred to as uncomfortable terms). However, in the conventional medical tubes, this discomfort is not particularly regarded as a problem, and the fact is that little consideration has been given to the discomfort. No consideration has been given to this point in the cannula disclosed in the above-mentioned U.S. Patent Specification. On the contrary, the cannula disclosed in the above-mentioned U.S. Patent Specification has a two-layered tube composed of a hydrophobic resin for the inner layer to alleviate swelling due to body fluid, but the constituent material is highly hydrophilic. However, after insertion into the body, it cannot prevent swelling due to contact with blood or the like, and has a serious drawback of increasing discomfort. Such uncomfortable feeling, coupled with the physical restraint caused by placing the medical tube in the body, may cause physical and mental distress.

Recently, an enteral diet catheter (ED catheter) has attracted attention. The ED catheter is placed in the duodenum from the mouth or nose via the throat, esophagus, and stomach for the purpose of component nutrition, enteral nutrition, and administration of liquid food. At present, ED catheters made of EVA or silicone resin are used. EVA catheters are too hard to insert easily because they are too hard, but have a strong pain and discomfort. In addition, silicone resin is too soft and difficult to insert. Therefore, while being easy to insert,
There is a long-awaited need for an ED catheter that has less pain and discomfort during insertion and placement.

[0005] It is an object of the present invention to provide a medical tube which is easy to insert into a body and has little pain and uncomfortable feeling when placed in or removed from the body.

[0006]

Means for Solving the Problems The present inventors have made various studies to achieve the above object, and found that a medical tube made of an organic polymer having the following specific mechanical loss tangent and transverse elastic modulus. Found that these were all satisfied. Further, they have found that the discomfort is further improved by setting the water absorption of the insertion tube to a specific range.

That is, the medical tube according to the present invention is characterized by comprising an organic polymer having a mechanical loss tangent at body temperature of at least 0.5 and a transverse elastic modulus at body temperature of 1 to 1000 MPa. In a more preferred embodiment, the organic polymer has a water absorption at a body temperature of 5% by weight or less.

[0008] In the present invention, a medical tube refers to any tube-shaped medical device (eg, catheter, cannula, irrigator) used by being inserted into an animal body including a human for inspection, observation, diagnosis, treatment / prevention or other purposes. , Bougies, etc.). That is, the tube is made of a specific organic polymer, a liquid injecting / discharging function, a body temperature measuring function, a blood pressure / blood measuring function, a chemical analyzing function, an endoscopic function, a function equipped with a laser fiber or a balloon, etc. It varies widely depending on the application area and the purpose and function of the circulatory system, respiratory system, digestive system, urinary system, reproductive system, etc.

Specific examples of the medical tube include a venous indwelling catheter, a heart catheter, an angiographic catheter, a vascular dilatation catheter, a thrombectomy catheter, a bile duct catheter, a bronchial tube, a gastric tube catheter, an epidural catheter, Esophageal bougie, central venous catheter, drainage tube, pancreatic duct tube, cervical indwelling catheter,
Examples include endoscope catheters, urinary catheters, nasal oxygen catheters, suction catheters, trocar catheters, ED catheters, infusion tubes, and the like.

[0010] The tube can be used for mammals including humans (for example, cows, rabbits, horses, sheep, monkeys, dogs, cats, etc.). Therefore, the body temperature in the present invention means the body temperature of each of these animals, and the temperature differs depending on the animal species.

The organic polymer constituting the medical tube of the present invention has a mechanical loss tangent (tan) at body temperature (T ° C.).
δ _T ) is at least 0.5, preferably at least 1.
0, more preferably at least 2.0. t
If Anderuta _T is less than 0.5, always giving tightness to the surrounding tissue in the body insertion state for too hard, i.e. give rise to discomfort, also when moving muscle portion thereof, if painful Because there is even.

The medical tube of the present invention has a transverse elastic modulus (G _T ) at body temperature of 1 to 1000 MPa, preferably 1 to 1000 MPa.
0 to 500 MPa, more preferably 20 to 100 MPa
It is. If G _T of the medical tube exceeds the 1000 MPa, for the tube itself is too hard, the tan [delta _T, such as always giving tightness to the surrounding tissue, i.e. give rise to discomfort in the body insertion state, 0.5 There are similar disadvantages as being less than. On the other hand, those G _T is less than 1 MPa, In the conventional medical tubes for mechanical strength is low, the tube is a problem of collapse in the body pressures. In particular, since a vein indwelling catheter (hereinafter, simply referred to as a cannula), an ED catheter, and the like are left in the body for a long time, it is required to minimize discomfort.

In the present invention, the above two physical properties are values measured by the following methods. tan δ: A value obtained by measuring the dynamic loss elastic modulus A and the dynamic storage elastic modulus B, and calculating A / B. G _T: as a measuring instrument RMS800 (Rheometrics, Inc.)
Is a value measured under conditions of applying torsional vibration at a frequency of 1.0 Hz.

In a preferred embodiment, an organic polymer having a water absorption of 5% by weight or less, preferably 2% by weight or less, particularly preferably 1.5% by weight or less is recommended. When the water absorption exceeds 5% by weight, the surrounding tissue is pressed by the swelling of the tube, which often causes a sense of discomfort. This tendency is particularly strong when the medical tube of the present invention is applied as a cannula, an ED catheter or the like.
The water absorption is measured at the body temperature of an animal to which the medical tube of the present invention is applied (for example, 36.5 ° C., which is a human body temperature).
It was measured by immersing it in a water absorbing state for a period of time and drying it at 150 ° C. for 30 minutes, and quantifying the precipitated water with a Karl Fischer moisture meter.

The medical tube of the present invention has the above-mentioned flexibility in a state where the tube is inserted into the body, in other words, at the body temperature, and has a room temperature before insertion or a low temperature artificially prepared (for example, 10 to 15). (° C) is preferred from the viewpoint of piercing resistance.

Further, the present invention is, for example, as shown in FIG.
When applying to a cannula having a metallic inner needle (for example, a stainless steel inner needle), if the rigidity immediately before insertion into the body is insufficient, the cannula is turned up from the inner needle at the time of insertion and greatly increases the penetration resistance. Although there is a problem, and in some cases, a problem of causing severe pain to the patient, it is preferable to have sufficient rigidity also from the viewpoint of preventing this turning. Further, since the ED catheter is placed in the duodenum from the mouth or nose via the throat, esophagus and stomach, it is preferable that the ED catheter has sufficient rigidity. _{Specifically, G T-10 / G T} ( here G _T-10 is modulus of transverse elasticity at 10 ° C. below body temperature) of at least 2, preferably at least 3, particularly preferably at least 8 .

In the present invention, as the organic polymer, if it satisfies the condition that the mechanical loss tangent at body temperature is at least 0.5 and the transverse elastic modulus at body temperature is 1 to 1000 MPa, Any material may be used as long as it is harmless to the animal.
Specifically, polyurethane, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer and the like are preferable, and polyurethane is particularly preferable.

The isocyanate component used for producing the polyurethane is not particularly limited as long as it is usually used for polyurethanes. For example, 2,4- or 2,6-tolylene diisocyanate, 4,4 ' -Diphenylmethane diisocyanate, hexamethylene diisocyanate, m- or p-phenylene diisocyanate, isophorone diisocyanate, and the like, and these can be used alone or in combination of two or more. As the isocyanate component, 4,4′-diphenylmethane diisocyanate is particularly preferred.

As the polyol component, one having at least two or more active hydrogens in one molecule, particularly a hydroxyl group, is used. For example, polyhydric alcohols such as diols and triols, aliphatic amines, aromatic amines and the like are used. Agent, a polyoxyalkylene polyol produced by adding an alkylene oxide thereto, a polyester polyol produced by condensing an acid and an alcohol, or polytetramethylene glycol, polybutadiene polyol, polypropylene glycol, poly-1,4-butylene glycol Adipate, polyethylene glycol adipate, polytetramethylene glycol, polyethylene glycol, bisphenol-A + propylene oxide, particularly preferably bisphenol-A + propylene oxide It is used. The preferred weight average molecular weight of the polyol is about 200-2000.

As the chain extender, ethylene glycol,
Glycols such as 1,4-butanediol and diethylene glycol, amines such as diethanolamine, triethanolamine, tolylenediamine and hexamethylenediamine, TDI (tolylenediisocyanate) adduct of trimethylolpropane, triphenylmethane triisocyanate, bis ( 2-hydroxyethyl) hydroquinone, bisphenol-A + ethylene oxide,
Examples include polyisocyanates such as bisphenol-A + propylene oxide. As the chain extender, 1,4-butanediol is particularly preferred.

The molar ratio of the isocyanate component, the chain extender and the polyol component is from 1.5 to 3: 0.5 to
2: 1, preferably 1.8-2.5: 0.8-1.5:
1, more preferably 1.9 to 2.2: 0.9 to 1.2: 1 for both the cannula and the ED catheter.

Further, a catalyst is used if necessary to accelerate the reaction. Examples of the catalyst include tertiary amines such as triethylamine, tetramethylhexamethylenediamine, and tolylenediamine, and metal catalysts represented by tin catalysts such as stannas octylate, stannas oleate, and dibutyltin dilaurate. Are used alone or in combination.

Urethane is synthesized using the above-mentioned isocyanate, polyol, chain extender and, if necessary, a catalyst. As the synthesis method, for example, the methods disclosed in JP-A-61-293214 and JP-A-63-244341 can be adopted.

The medical tube of the present invention can be produced by using a material as described above by a means known per se, for example, extrusion molding.

The outer diameter and wall thickness of the medical tube of the present invention may be, for example, 0.5 mm or more for a cannula.
2.8 mm, wall thickness 0.05 mm to 0.4 mm, preferably outer diameter 0.6 mm to 2.3 mm, wall thickness 0.1 mm to 0.4 mm.
3 mm. In the ED catheter, the outer diameter is 1.0 mm to 4.0 mm, and the wall thickness is 0.1 mm to 1.2 m.
m, preferably an outer diameter of 1.6 mm to 3.5 mm, and a wall thickness of 0.1 mm.
It is 2 mm to 0.7 mm.

[0026]

EXAMPLES The present invention will now be described specifically with reference to examples, but the present invention is not limited to these examples.

Examples 1 to 10 and Comparative Examples 1 to 5 Cannulae were produced by extrusion using various organic polymers shown in Table 1 as constituents of the cannula, and an inner needle made of SUS304 was added thereto. The insert was manufactured. Table 1 shows the chemical species of the materials and 36.5 ° C. and 2
The various physical properties measured at 6.5 ° C. are shown. Of the materials to be displayed, materials 1 to 10 are Examples 1 to 10 of the present invention, respectively.
The materials 21 to 25 to be used in the cannula are materials to be used in Comparative Examples 1 to 5, respectively. Table 2 shows the types and amounts (molar ratios) of the isocyanate component, the polyol component, and the chain extender used for the polyurethanes shown in Table 1.

[0028]

[Table 1]

[0029]

[Table 2]

Test Example 1 The insertion tube of the present invention was examined for any uncomfortable feeling. FIG.
FIG. 3 is a cross-sectional view of the cannula 1 used in this test. That is, it is made of the materials described in Examples 1 to 10 and Comparative Examples 1 to 5, and has an outer diameter of 1.32 mm, an inner diameter of 0.96 mm, and a wall thickness of 0.1.
A cannula having an indwelling part 4 having a length of 8 mm and a length of 70 mm and a hub 2 made of polypropylene is manufactured through a normal extrusion molding method (using a core wire), and an inner needle 3 made of SUS304 having a sharp tip is formed thereon. Created what was inserted.
The tip of the indwelling portion is tapered, and the thickness of the tip is approximately half that of the center.

Each cannula prepared as described above was tested for discomfort when applied to humans by the following method. The results are shown in Table 3.

(Test Method) For each of ten healthy persons, each cannula was inserted into the ulnar cutaneous vein of the left arm, and it was confirmed that blood had flowed out. Then, only the inner needle 3 was withdrawn, and blood was drawn from the hub side. 3 minutes later, the cannula was moved to check for uncomfortable feeling.

(Judgment method) The feeling of discomfort of each person was represented by a score according to the following criteria, and the average value of the scores of 10 people was determined.

5 points: almost no discomfort 4 points: some discomfort 3 points: discomfort 2 points: relatively strong discomfort 1 point: strong discomfort

Test Example 2 For each cannula used in Test Example 1, the puncture resistance and the presence or absence of the turning-up phenomenon were examined.

(1) Method of Evaluating the Turn-Up Phenomenon The cannula was pierced into six pieces of medicine packaging paper (white paraffin paper, medium size: 105 mm × 105 mm) at a penetration speed of 100 mm / min. It was visually determined and compared with that of the comparative example. Table 3 shows the results.
It was shown to.

(2) Penetration Resistance Evaluation Method Each of the cannulas used in Test Example 1 was used as a measuring device by using a tensile tester Autograph, Shimadzu S500D.
A rubber plate (NRJISK6301) with a penetration speed of 00 mm / min
The penetration resistance (gf) of the parallel portion following the tip of the cannula when piercing to a thickness of 1.5 mm and a Shore A hardness of 30) was measured and compared with that of the comparative example. The results are shown in Table 3.

[0038]

[Table 3]

Examples 11 to 12 and Comparative Examples 6 and 7 A tube made of the material described in Example 8 and having an outer diameter of 3.5 mm, an inner diameter of 3.0 mm, a wall thickness of 0.25, and a length of 1200 mm (Example 11) ) And the material described in Example 9;
Outer diameter 3.5mm, inner diameter 3.0mm, wall thickness 0.25, length 12
A 00 mm tube (Example 12) was prepared by ordinary extrusion molding (tube molding), an inlet was provided at one end, and a 0.5 g weight was provided at the other end at a discharge part and a part following the discharge part. A catheter was made. For comparison, an outer diameter of 3.5 mm, a diameter of 3.0 mm, a wall thickness of 0.25, and a length of 1200 mm made of ethylene vinyl acetate copolymer (EVA) (Comparative Example 6) and made of silicone resin (Comparative Example 7).
An ED catheter similar to the one described above was prepared.

Test Example 3 The insertion tube of the present invention was examined for insertability, pain after insertion, and for any uncomfortable feeling.

(Test Method) Each of the ED catheters prepared as described above was placed in the duodenum for 24 hours through the nose, throat, esophagus and stomach of six healthy persons, respectively.
Investigate its insertion, pain and discomfort at the time of placement,
Table 4 shows the results.

[0042]

[Table 4]

The characteristics of the EVA and the silicone resin used in this test example at 26.5 ° C. and 36.5 ° C. are as follows.

EVA silicone resin tan δ _T : 5 × 10 ^-2 3 × 10 ^-2 tan δ _T-10 : 5 × 10 ^-2 3 × 10 ^-2 G _T : 22 MPa 10.5 MPa G _T-10 : 25 MPa 10 _{.5MPa G T-10 / G T} 1.1 1.0 water absorption: 0.4 wt% 0.1 wt%

[0045]

As is clear from the above test results, the medical tube of the present invention has excellent rigidity when inserted into an animal body, so that it can be easily inserted into the body.
In addition, while exhibiting sufficient pressure crush resistance and buckling resistance when inserted into an animal body, it is more flexible than conventional products, so that even if it is left in the body for a long time, there is little discomfort.

In particular, those having a water absorption of 5% by weight or less do not swell in blood vessels and the like unlike conventional tubes having high hydrophilicity, and thus have an advantage that they can be used with less discomfort. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a cannula used in a test example of the present invention.

[Description of Signs] 1 cannula 2 hub 3 inner needle 4 indwelling part 5 plug

──────────────────────────────────────────────────続 き Continuing on the front page (72) Takashi Matsumoto 3-9-3, Honjo-Nishi, Kita-ku, Osaka-shi Nissha Corporation (72) Inventor Hajime Tsujikawa 3-9-1, Honjo-Nishi, Kita-ku, Osaka (72) Inventor: Shunichi Hayashi, Nagoya City, Nagoya-shi, Iwatsuka-cho, Takamichi 1, Nagoya Research Laboratories Co., Ltd. (72) Inventor Satoru Kondo, Nagoya, Nakamura-ku, Iwatsuka-cho, Takamichi, 1-3-1 Inside Nagoya Research Laboratories Co., Ltd. (72) Atsushi Utsumi 4-3-1 Ikejiri, Itami-shi, Hyogo Mitsubishi Electric Wire Industry Co., Ltd.Itami Seisakusho Co., Ltd. (58) Investigated field (Int. Cl. ⁶ , DB name) A61L 29/00

Claims (10)

(57) [Claims] 1. A mechanical loss tangent at body temperature of at least 0.5 and a transverse elastic modulus at body temperature of 1 to 1000 M
A medical tube comprising an organic polymer of Pa. 2. The medical tube according to claim 1, wherein the transverse elastic modulus at a temperature lower by 10 ° C. than the body temperature is made of an organic polymer having a transverse elastic modulus at least twice the body temperature. 3. The medical tube according to claim 1, wherein the water absorption of the organic polymer at body temperature is 5% by weight or less. 4. The medical tube according to claim 1, wherein the organic polymer is polyurethane. 5. The polyurethane according to claim 4, wherein the polyurethane is a polyether polyurethane or a polyester polyurethane.
The medical tube as described. 6. The polyurethane according to claim 1, wherein the molar ratio of the isocyanate component, the chain extender and the polyol component is from 1.5 to 1.5.
The medical tube according to claim 4, wherein the ratio is 3: 0.5 to 2: 1. 7. The polyurethane according to claim 1, wherein the molar ratio of the isocyanate component, the chain extender and the polyol component is from 1.8 to 1.8.
The medical tube according to claim 6, wherein the ratio is 2.5: 0.8 to 1.5: 1. 8. The polyurethane according to claim 1, wherein the molar ratio of the isocyanate component, the chain extender, and the polyol component is from 1.9 to 1.9.
The medical tube according to claim 7, wherein the ratio is 2.2: 0.9 to 1.2: 1. 9. The medical tube according to claim 1, which is an indwelling venous catheter. 10. The medical tube according to claim 1, which is an enteral feeding catheter.