JPH0228339B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION () Background Art (-1) Technical Field The present invention relates to an improved catheter for endotracheal tube suction and other uses, which has less insertion resistance at its insertion tip.

(-2) Prior art and its problems As shown in Fig. 1, the outer surface 1a of a catheter 1 used for suctioning an endotracheal tube during intubation is attached to the outer surface 1a of a catheter 1 (not shown) that has been inserted into the trachea or the like beforehand. In order to enable smooth insertion into the large diameter tube, the matte surface is treated with a so-called embossing process. The insertion end 1b of the catheter has a rounded shape to enable smooth insertion as described above. However, the conventional method of processing the insertion end 1b of the catheter is to heat a mold (or glass mold) 2 made of nickel or the like from the back with a burner 3, as shown in FIG. When mold 2 reaches a temperature of approximately 150°C, remove burner 3 and immediately press the cut end of catheter 1 against mold 2. After a few seconds, cool mold 2 by blowing cold air, etc., and remove the catheter. By stabilizing the processed shape of the tip of the catheter 1 and then separating the catheter 1 from the mold 2,
The insertion side end 1b of the catheter was formed as shown in the figure. However, according to this processing method, at least the range 1 of the insertion side end 1b of the outer surface of the catheter 1 shown in FIG. 1 had a mirror surface due to the heat received from the mold. As described above, when a catheter having a mirror-finished insertion end 1b is inserted into an endotracheal tube, there is a risk that the catheter 1 will come into close contact with the inner surface of the endotracheal tube and cannot be inserted smoothly. In particular, when using a catheter, multiple treatments are often performed on the patient appropriately, quickly, and at the same time, and if the catheter is not inserted smoothly in such cases, the doctor will become impatient and the treatment will be adversely affected. Otherwise, the force of catheter insertion may be transmitted to the wall of the trachea through the endotracheal tube, causing extreme pain to the patient. The above-mentioned damage occurs similarly even if a catheter having a mirror-finished insertion end is directly inserted into the trachea or the like.

() Purpose of the invention The present invention was devised in view of the above points, and
It can be inserted smoothly into the endotracheal tube inserted into the trachea or the trachea, eliminating the anxiety of doctors during treatment and preventing the insertion force from being transmitted to the wall of the trachea, causing pain to the patient. The present invention provides a catheter suitable for endotracheal tube suction.

According to the present invention, in a tubular catheter made of a thermoplastic polymer material, the insertion side end has a diameter reduced to a rounded corner shape with its outer surface facing the end surface and substantially intersecting with its inner surface. an open end forming a substantially linear circular end surface;
Furthermore, the present invention is achieved by a catheter characterized in that the outer surface of the insertion end is finished with a matte surface that is uniform with the other outer surface of the catheter.

The entire outer surface of the catheter, including the outer surface of the insertion end, is finished with a uniform satin surface, which reduces insertion resistance at the insertion end. If the outer surface of the catheter is rougher than other surfaces, there is a problem that the insertion resistance increases as in the case of a mirror surface.

The catheter, whose outer surface is finished with a uniform matte finish over the entire surface, can be made by high-frequency heating using a pair of male and female molds. That is, one of a pair of electrodes that can perform high-frequency heating is arranged in the shape of a column with a tapered tip, a processing space is provided around it, and the other electrode is arranged in the shape of a cylinder with a tapered depth. The cut tip of a catheter made of tube-shaped thermoplastic polymer material is pressed against the mold having the desired shape, and high-frequency heating is applied to the extent that the catheter does not soften to the extent that the outer surface of the catheter is softened. The catheter is thermoplastically deformed into a shape according to the mold, the cut tip surface of the catheter is released to the inner side, the tip is made into a deflated shape, and then high frequency oscillation is stopped and the catheter is cooled to stabilize the tip shape of the catheter. The catheter can be made by:

The catheter of the present invention is not limited to those made by the above-mentioned high-frequency processing method, but the tip shape of the catheter is obtained using the heated mold mentioned at the beginning, and then the specular portion of the tip is subjected to a satin finish. Alternatively, the cut end of the catheter may be rounded by mechanical cutting and then subjected to a satin finish. However, if the above-mentioned high-frequency processing method is not used, the matte surface of the outer surface of the insertion side tip is often finished rougher than the rest of the matte surface. It is preferable to make it with

() Detailed Description of the Present Invention FIG. 3 is a sectional view of the insertion end of a catheter according to a preferred embodiment of the present invention. The catheter 1 has a tube shape made of a thermoplastic polymer material, and the insertion end thereof has an outer surface 1b facing the end surface and contracting in diameter into a rounded corner shape, and an inner surface 1c facing the end surface and expanding in diameter to form the outer surface 1b. The inner surfaces 1c substantially intersect to form a substantially linear circular end surface 1d, forming an open end, and the outer surface 1b of the insertion side end has a uniform satin finish with the other outer surface 1a of the catheter. The surface is finished.

FIG. 4 is an explanatory diagram of a method of processing the insertion side end of the catheter of the present invention. As shown in the figure, this processing method uses a mold D. The mold D includes a pair of electrodes capable of performing high-frequency heating, one of which is a columnar electrode 4, and a processing space 5 is provided around the other electrode 6, which has a cylindrical wall shape. and 6 are fixed together at their bases by sandwiching an insulator 7 made of fluorine resin, glass, polycarbonate, etc. Either of the electrodes 4 and 6 may be used as a positive electrode or a negative electrode. The electrode 4 has a tapered portion 4a, the electrode 6 has a rounded depth front portion 6b that continues from the tapered hole surface portion 6a having a small diameter, and the insulator 7 has a cylindrical shape. A tapered surface portion 7a is formed at the tip of the outer surface. In this processing method, a tube-shaped thermoplastic polymer such as polyvinyl chloride is molded into a mold D having the shape described above, and a catheter 1 whose outer surface is matte is pressed with a constant thrust of, for example, about 50 g, and an electrode is inserted into the mold D. By passing a high frequency current of constant strength between 4 and 6, the catheter 1
is softened by high-frequency heating, and the catheter 1 under the action of the thrust undergoes thermoplastic deformation according to the shape of the mold D, and high-frequency oscillation occurs before the softening progressing from the center of the thickness of the catheter reaches the outer surface. The catheter of the present invention is obtained by stopping the process and then pressing the catheter 1 against the mold D for several seconds to stabilize the processed shape. Therefore, when making the catheter of the present invention using this high frequency processing method, a catheter material whose outer surface is a satin surface before processing is used, and the outer surface of the cut end of the catheter is formed into the tapered hole of the mold 6. The shape changes as it is guided by the surface portion 6a and the deep front portion 6b, and becomes a rounded corner shape 1b with a smaller diameter toward the end. Along with this, the cut surface of the catheter escapes to the inner surface side and becomes an inner surface portion 1c.

The method of satin finish processing is described in Japanese Patent Application Laid-Open No. 121861-1973.
No., JP-A-50-139845, JP-A No. 51-33834,
There are various methods such as Japanese Patent Publication No. 52-1415 and Japanese Patent Application Laid-Open No. 55-80438, but a preferred method for forming a matte surface on the outer surface of a catheter material is, for example, manufacturing a tube-shaped catheter material by extrusion molding. When the catheter material is continuously extruded from the mold, it is possible to spray air onto the catheter material near the mold to harden the resin instead of leaving it to cool. The resulting resin surface does not have a mirror surface, but can have a matte surface or a matte surface with extremely fine irregularities like frosted glass.

The following examples are examples in which the catheter of the present invention was obtained by the above-mentioned real frequency processing method.

Example 1 Mold D with the inter-electrode distance set to 0.95 m/m was attached to a high-frequency heating device manufactured by Seidensha Electronics Co., Ltd., and a soft mold with an outer diameter/inner diameter of 0.4 x 2.6 and a wall thickness of 0.7 m/m was attached. A tube made of polyvinyl chloride with a satin finish is pressed against mold D with a thrust of approximately 50 g, and the frequency is adjusted.
The results of searching for a processing area in which the catheter of the present invention can be obtained by performing high-frequency heating at 40.46MHz, pressing the tube as it is after stopping the oscillation, and allowing a cooling time of 1 second or more to stabilize the processed shape are shown in Figure 5. The graph shown in is obtained.

Example 2 A catheter of the present invention is obtained by pressing a test material with an outer diameter/inner diameter of 4.7/3.1 and a wall thickness of 0.7 m/m into a mold with an interelectrode distance of 0.98 m/m and performing high-frequency heating. As a result of searching for a suitable machining area, the graph shown in FIG. 6 was obtained (however, other conditions were the same as in Example 1 above).

Example 3 A test material with an outer diameter/inner diameter of 5.3/3.4 and a wall thickness of 0.95 m/m was pressed into a mold with an electrode distance of 11.3 m/m, and high-frequency heating was performed to search for a suitable processing area. As a result, the graph shown in FIG. 7 was obtained (however, other conditions were the same as in Example 1 above).

The results of measuring the relationship between the tuning scale of the high-frequency heating device manufactured by Seidensha Electronics Co., Ltd. and the anode current of the mold are shown in FIG. 8 for reference.

Although the catheter of the present invention is not limited to those made by the above-mentioned high-frequency processing method, catheters obtained by this processing method are ideal because the outer surface of the catheter has a uniform matte surface.

() Specific functions and effects of the present invention As explained above, the catheter of the present invention is a tube-shaped catheter made of a thermoplastic polymer material, and the outer surface of the insertion side end faces toward the end and is contracted into a rounded corner shape. The diameter of the catheter substantially intersects with the inner surface of the catheter to form a substantially linear circular cross section, and the outer surface of the catheter including the outer surface of the insertion side end has a uniform matte surface throughout.

Therefore, when the catheter of the present invention is inserted into the patient's trachea through the tracheal tube or directly, the insertion is extremely smooth and does not pull on the patient's tracheal wall or cause any damage to the patient. This eliminates the fear, and as a result, the doctor does not have to worry or be confused during treatment, and the reliability of the doctor is significantly improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view for explaining the insertion side end of a conventional catheter. FIG. 2 is an explanatory diagram of a method of processing the insertion side end of a conventional catheter. Third
The figure is a sectional view of the insertion side end of the catheter according to the embodiment of the present invention. FIG. 4 is an explanatory diagram of a method of processing the insertion side end portion to obtain the catheter of the present invention. Figures 5, 6, and 7 are graphs that search for suitable machining areas using variables such as anode current and oscillation time, which are high-frequency oscillation output, under different conditions, and Figure 8 is a high-frequency wave used as an example. 2 is a graph showing the relationship between the tuning purpose of the heating device and the anode current. 1...Catheter, 1a...Outer surface of the catheter, 1b...Outer surface of the insertion end of the catheter, 1
c...Inner surface of the insertion end of the catheter, 1d...
End face.

Claims (1)

[Claims] 1. In a tube-shaped catheter made of a thermoplastic polymer material, the insertion side end has an outer surface facing the end surface, reduces in diameter into a rounded corner shape, and substantially intersects with the inner surface to form a substantially linear circular end surface. 1. A catheter characterized in that the outer surface of the insertion side end is finished with a matte surface that is uniform with the outer surface of the other catheter.