JPH0584293A - Tube for medical use - Google Patents

Abstract

(57) [Summary] [Structure] Mechanical loss tangent at body temperature is at least 0.5 and transverse elastic modulus at body temperature is 1 to 1000MP.
A medical tube made of an organic polymer which is a. [Effect] The medical tube can be easily inserted into the body and has less pain and discomfort when being placed in the body or removed from the body.

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 an animal body, particularly a human body, or for discharging a liquid or the like from the body, and further for removing vasodilation, thrombus / embolus. Tubes, artificial blood vessels, artificial trachea, etc. used for
That is, a catheter used for the purpose of inspection, observation, prevention, treatment, etc. of diseases, a cannula,
It concerns bougie and other medical tubes.

[0002]

2. Description of the Related Art For example, medical tubes are inserted into blood vessels (especially coronary arteries), trachea, fallopian tubes, ureters, and various organs to inject, inhale, or pass a liquid. It is used for the purpose of securing patency.
With the progress of medical technology, recent catheters have become multifunctional, in addition to the above-mentioned ordinary functions, there are illumination fibers for internal vision, image guides, and even those with a flash hole. U.S. Pat. No. 4,846,812 proposes a cannula using a shape memory resin.

By the way, when a medical tube is inserted into, placed in, or removed from the body, it may cause discomfort, and in some cases, it may cause pain or suffering. The above situation is generally referred to as a term that makes people feel uncomfortable. However, in the conventional medical tube, this discomfort is not particularly regarded as a problem, and in reality, little consideration is given to the discomfort. The cannula disclosed in the above-mentioned U.S. Pat. On the contrary, the cannula disclosed in the above-mentioned U.S. Pat.No. 5,837,086 has a double-layered tube having an inner layer made of a hydrophobic resin to alleviate swelling due to body fluid, but the constituent material is highly hydrophilic. However, it has a serious drawback that it cannot prevent swelling due to contact with blood or the like after being inserted into the body and increases discomfort. Such an uncomfortable feeling, together with the physical restraint caused by placing the medical tube in the body, may cause physical and mental distress.

Recently, attention has been paid to enteral diet catheters (ED catheters). The ED catheter is placed in the duodenum via the mouth or nose through the throat, esophagus, and stomach for the purpose of administering component nutrition, enteral nutrition, and liquid food. Currently, an ED catheter made of EVA or a silicone resin is used, but EVA is too hard to insert because it is too hard, but it causes pain and discomfort. Further, the silicone resin is too soft and difficult to insert. Therefore, it is easy to insert and
There is a long-felt need for an ED catheter that is less likely to cause pain and discomfort during insertion and placement.

An object of the present invention is to provide a medical tube which is easy to insert into the body and has less pain and discomfort when being placed in the body or removed from the body.

[0006]

[Means for Solving the Problems] The inventors of the present invention 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 lateral elastic modulus. Found that they satisfied all of these. Further, they have found that the discomfort is further improved by setting the water absorption rate of the insertion tube within 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. A more preferred embodiment is characterized in that the water absorption of the organic polymer at body temperature is 5% by weight or less.

In the present invention, the term medical tube means all tubular medical devices (eg, catheter, cannula, illigator) used by being inserted into an animal body including human for inspection, observation, diagnosis, treatment / prevention or other purposes. , Bougie, etc.). That is, the tube is made of a specific organic polymer and has a liquid injection / exhaustion function, a body temperature measurement function, a blood pressure / blood measurement function, a chemical analysis function, an endoscopic function, a laser fiber, a balloon, etc. There are a wide variety depending on the application area such as circulatory system, respiratory system, digestive system, urinary system, reproductive system, and purpose / function.

Specific examples of medical tubes include indwelling catheters, cardiac catheters, angiographic catheters, vasodilators, thrombus-removing catheters, bile duct catheters, bronchial tubes, gastric tube catheters, epidural catheters, Esophageal bougie, central venous catheter, drainage tube, pancreatic duct tube, cervical indwelling catheter,
Examples thereof include endoscopic catheters, urinary catheters, nasal oxygen catheters, suction catheters, trocar catheters, ED catheters, infusion tubes, and the like.

The tube can be used for mammals including human beings (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 varies 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
When an δ _T is less than 0.5, it is too hard and always gives a feeling of tightness to surrounding tissues when inserted into the body, that is, it causes discomfort, and when the muscle of that part moves, it causes pain. Because there is even one.

[0012] The medical tube of the present invention, modulus of transverse elasticity at body temperature (G _T) is 1～1000MPa, preferably 1
0 to 500 MPa, more preferably 20 to 100 MPa
Is. If the G _{T of the} medical tube exceeds 1000 MPa, the tube itself is too hard, and thus the tan δ _T that gives a feeling of tightness to surrounding tissues in the state of being inserted into the body, that is, causes discomfort, etc. is 0.5. It has the same drawbacks as when it is less than. On the other hand, if G _T is less than 1 MPa, the mechanical strength is low, and therefore, there is a problem that the tube is crushed by the internal pressure of a normal medical tube. In particular, intravenous catheters (hereinafter simply referred to as cannulas), ED catheters, and the like are required to be left in the body for a long time, so that it is necessary to reduce the discomfort as much as possible.

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

As a preferred embodiment, it is recommended that the water absorption of the organic polymer is 5% by weight or less, preferably 2% by weight or less, particularly preferably 1.5% by weight or less. If the water absorption rate exceeds 5% by weight, the swelling of the tube will squeeze the surrounding tissue, often causing a feeling of strangeness. 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 rate is measured at a body temperature of an animal to which the medical tube of the present invention is applied (for example, a human body temperature of 36.5 ° C.), and the sample is immersed in water having a temperature corresponding to the body temperature.
It was measured by immersing it for a time in a water-absorbed state, drying it at 150 ° C. for 30 minutes, and quantifying the precipitated water with a Karl Fischer water content measuring device.

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, body temperature, and has room temperature before insertion or a low temperature artificially prepared (for example, 10-15). From the viewpoint of piercing resistance, it is preferable to have sufficient rigidity at (° C.).

Further, the present invention can be implemented by, for example, as shown in FIG.
When applying to a cannula with a metallic inner needle (for example, a stainless steel inner needle), if the rigidity is insufficient immediately before insertion into the body, the cannula will be flipped over from the inner needle during insertion, greatly increasing the piercing resistance. Although there is a problem that it causes severe pain to the patient depending on the case, it is preferable to have sufficient rigidity from the viewpoint of preventing the curling. In addition, since the ED catheter is placed in the duodenum through the mouth or nose, the throat, the esophagus, and the stomach, it is preferable that the ED catheter has sufficient rigidity. Specifically, it is desirable that G _T-10 / G _T (where G _T-10 is a transverse elastic modulus at a temperature 10 ° C. lower than body temperature) is at least 2, preferably at least 3, and particularly preferably at least 8. ..

In the present invention, the organic polymer is an insertion target as long as it satisfies the conditions 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 animals.
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 polyurethane, and for example, 2,4- or 2,6-tolylene diisocyanate, 4,4 '. -Diphenylmethane diisocyanate, hexamethylene diisocyanate, m- or p-phenylene diisocyanate, isophorone diisocyanate, etc. are exemplified, and they are used alone or in combination of two or more kinds. As the isocyanate component, 4,4'-diphenylmethane diisocyanate is particularly preferable.

As the polyol component, one having at least two or more active hydrogens, particularly a hydroxyl group, in one molecule is used. For example, polyhydric alcohols such as diols and triols, aliphatic amines and aromatic amines are started. As an agent, polyoxyalkylene polyol produced by adding alkylene oxide thereto, polyester polyol produced by condensation of acid and 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, and particularly preferred bisphenol-A + propylene oxide. It is used. The preferable weight average molecular weight of the polyol is about 200 to 2000.

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

The molar ratio of these isocyanate component, chain extender and polyol component is from 1.5 to 3: 0.5.
2: 1, preferably 1.8-2.5: 0.8-1.5:
1 and 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 to accelerate the reaction if necessary. Examples of the catalyst include tertiary amines such as triethylamine, tetramethylhexamethylenediamine and tolylenediamine, and metal catalysts represented by tin-based catalysts such as stannas octylate, stannas oleate and dibutyltin dilaurate. Each is used alone or as a mixture.

Urethane is synthesized using the above-mentioned isocyanate, polyol, chain extender and, if necessary, catalyst. As a synthesizing 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 a means known per se, such as extrusion molding, using the above-mentioned materials.

The outer diameter and wall thickness of the medical tube of the present invention are, for example, in a cannula, an outer diameter of 0.5 mm to
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.
It is 3 mm. In addition, the ED catheter has an outer diameter of 1.0 mm to 4.0 mm and a wall thickness of 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.
It is 2 mm to 0.7 mm.

[0026]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto.

Examples 1 to 10 and Comparative Examples 1 to 5 Various organic polymers shown in Table 1 were used as the organic polymer for forming the cannula, and the cannula was manufactured by extrusion molding, and the inner needle made of SUS304 was added thereto. The insert was manufactured. Table 1 shows the material species and 36.5 ° C and 2
The physical properties measured at 6.5 ° C are shown. Materials 1 to 10 among the materials to be displayed are Examples 1 to 10 of the present invention, respectively.
The materials to be used in the cannula and the materials 21 to 25 are to be used in Comparative Examples 1 to 5, respectively. Regarding the polyurethane shown in Table 1, Table 2 shows the types and amounts (molar ratios) of the isocyanate component, the polyol component and the chain extender used.

[0028]

[Table 1]

[0029]

[Table 2]

Test Example 1 The insertion tube of the present invention was examined for the presence or absence of discomfort. Figure 1
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, the outer diameter is 1.32 mm, the inner diameter is 0.96 mm, and the wall thickness is 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 was manufactured through an ordinary extrusion molding method (using a core wire), and an inner needle 3 made of SUS304 having a sharp tip part was manufactured on the cannula. I created an insert.
The tip portion of the indwelling portion is tapered and thin, and the wall thickness of the tip portion is about half that of the central portion.

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

(Test method) For each of 10 healthy persons, each cannula was inserted into the basilic vein of the left arm, and after confirming that blood was flowing out, only the inner needle 3 was pulled out, and blood was drawn from the hub side. Was confirmed to flow out, and after 3 minutes, the cannula was moved to check if there was any discomfort.

(Judgment Method) The discomfort of each person was expressed as a score according to the following judgment criteria, and the average value of the scores of 10 people was calculated.

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

Test Example 2 With respect to each cannula used in Test Example 1, the presence or absence of puncture resistance and swelling phenomenon was examined.

(1) Evaluation method for blistering phenomenon A cannula was punctured on 6 sheets of medicine packing paper (white paraffin paper, medium size: 105 mm × 105 mm) at a piercing speed of 100 mm / min to check whether the tip of the cannula was blunted. It was judged visually and compared with that of the comparative example. The results are shown in Table 3.
It was shown to.

(2) Penetration resistance evaluation method Each of the cannulas used in Test Example 1 was measured using a tensile tester Autograph, Shimadzu S500D as a measuring device.
Rubber plate with piercing speed of 00 mm / min (NRJISK6301
The puncture resistance (gf) of the parallel part following the tip of the cannula when punctured to a thickness of 1.5 mm and 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 to 7 Tubes 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 3.5 mm, inner diameter 3.0 mm, wall thickness 0.25, length 12
A tube of 00 mm (Example 12) was prepared by ordinary extrusion molding (tube molding), an inlet portion was provided at one end thereof, and a discharge portion and a weight portion of 0.5 g were provided at a portion following the inlet portion at the other end thereof. A catheter was created. As a comparison, an outer diameter of 3.5 mm, a diameter of 3.0 mm, a wall thickness of 0.25, and a length of 1,200 mm made of ethylene vinyl acetate copolymer (EVA) (comparative example 6) and silicon resin (comparative example 7) are used.
An ED catheter similar to the one described above, which was composed of the above tube, was prepared.

Test Example 3 The insertion tube of the present invention was examined for insertability, presence or absence of pain and discomfort after insertion.

(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 6 healthy individuals,
Check the insertability, pain and discomfort during detention,
The results are shown in Table 4.

[0042]

[Table 4]

The characteristics of EVA and 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 .5 MPa 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, and thus can be easily inserted into the body.
In addition, while exhibiting sufficient pressure resistance and buckling resistance when inserted into an animal body, and moreover, it is more flexible than conventional products, so that it does not feel strange even if left in the body for a long time.

In particular, a material having a water absorption rate of 5% by weight or less does not swell in a blood vessel or the like unlike a conventional tube having high hydrophilicity, and therefore has an advantage that it can be used with less discomfort. ..

[Brief description of drawings]

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

[Explanation of symbols]

 1 Cannula 2 Hub 3 Inner needle 4 Indwelling part 5 Plug

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Matsumoto 3-9-3 Honjo Nishi, Kita-ku, Osaka City Nitoshiyo Co., Ltd. (72) Inventor Hajime Tsujikawa 3-9-3 Honjo Nishi, Kita-ku, Osaka Stock company Nitsushio (72) Inventor Shunichi Hayashi 1 Takamichi, Iwazuka-cho, Nakamura-ku, Nagoya City Nagoya Research Institute, Mitsubishi Heavy Industries, Ltd. (72) Satoru Kondo 1 Highway Iwazuka-cho, Nakamura-ku, Nagoya City Mitsubishi Heavy Industries Nagoya Institute Co., Ltd. (72) Inventor Atsushi Utsumi 4-3 Ikejiri, Itami City, Hyogo Prefecture Mitsubishi Cable Industries Co., Ltd. Itami Works (72) Inventor Hoho 8 Nishinocho, Higashimukaijima, Amagasaki City, Hyogo Prefecture Mitsubishi Electric Line Industry Co., Ltd.

Claims (10)

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