JP2541872B2 - Medical tubular body - Google Patents

Description

TECHNICAL FIELD The present invention relates to a medical tubular body used for a catheter or the like inserted into the body.

[Problems to be Solved by Conventional Techniques and Inventions]

Conventionally, as this type of tubular body, a resin having an inner layer, a braid having an intermediate layer, and a resin having an outer layer has been generally used. However, a catheter or an endoscope using a tubular body having such a structure is used. However, it is difficult to change the lens or the like at the tip of the oscillating portion to a desired direction by hand rotation because the rotational torque cannot be sufficiently transmitted.

[Means for solving the problem]

In order to solve such a problem, the present invention comprises a metal flat plate close-wound coil, a metal rectangular braid that is externally fitted to the coil, and a resin coating layer that is further coated thereon.

[Work]

When used in catheters, endoscopes, etc., the compression resistance when pushed into the body is mainly obtained by the flat coil of the inner layer, and the pull resistance when pulled out is mainly obtained by the flat braid of the middle layer. Furthermore, since the flat plate close-wound coil and the flat braid are in surface contact with each other, the relative slippage is relatively small, the waist is strong, and the rotating torque at the outside of the body causes the tip inside the body. Good transmission to the parts, and high torque transmissibility. As described above, since it is possible to have a structure with high compression resistance, tensile strength, and torque transmission, in particular, the outer diameter can be a small diameter of 2 mm or less, and the wall thickness can be 0.2 mm or less. It becomes possible to
A small-diameter and multi-functional catheter or endoscope can be realized.

〔Example〕

 Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

1 to 4 show a tubular body T according to the present invention and an enlarged cross-sectional view of its main part. This tubular body T is used for medical purposes as a blood vessel, digestive tract, trachea, urinary tract, oviduct of a living body. Diagnosis, inspection, etc.
It is used for catheters for treatments, endoscopes, catheter guide sheaths, and the like. The structure is such that the metal flat plate close-wound coil 1 and the metal flat braid 2 externally fitted to it,
And a resin coating layer 3 coated thereon.

The plate close-wound coil 1 is, as shown in FIGS. 2 and 4,
If the width dimension of the flat wire is W and the gap dimension is G, the gap dimension G is set to be sufficiently small so that the relational expression of 0.01 · W ≦ G ≦ 0.05 · W.

If the gap size G is less than 0.01 mm, the flexibility required for a catheter, an endoscope or the like is lost, and it becomes difficult to insert the catheter into the body. On the other hand, if it exceeds 0.05 W, the rigidity to withstand the compressive force when pushed (inserted) into the body is insufficient. The flat plate close-wound coil 1 may be double-wound (left-handed and right-handed coils are stacked on the inner and outer layers).

Further, the flat braid 2 is a braided metal wire having a flat cross-sectional shape, as shown in FIG.

 Table 1 shows some examples of the main dimensions of each component.

In Examples No. I, II, and IV of Table 1, the flat plate close-wound coil 1 is single, but other than that, it has a double structure of an inner layer and an outer layer, and combines right-handed and left-handed windings. .

As a comparative example, when a tubular body using a round wire braid is used instead of the flat braid 2, a round wire for braid actually needs to have a minimum diameter of about 40 μm because of problems in strength. Therefore, the layer thickness of the braided portion is required to be at least 90 μm, and it is impossible to make the thickness A of the entire tubular body to 0.3 mm-300 μm-or less. Moreover, in the round wire braid, slippage with the outer peripheral surface of the flat plate close-wound coil 1 on the inner side is too good, and when the outer diameter dimension D is 2 mm or less, the stiffness is weak and the torque transmissibility is completely deteriorated.

On the other hand, in the present invention, as is clear from Table 1 above, the thickness of the flat braid 2 is sufficiently thin, and the overall wall thickness dimension A of the tubular body T can be 0.085 to 0.20 mm. In particular, the contact surface frictional force between the flat braid 2 and the flat plate close-wound coil 1 which are in surface contact with each other has an appropriate magnitude, and sufficient waist strength-torque transmissibility-is obtained, and the tubular body T
A major feature is that the wall thickness A can be set to 0.2 mm or less. Further, as is apparent from Table 1, the outer diameter dimension D can be 2.0 mm or less. That is, it is possible to manufacture a catheter or an endoscope having an extremely small diameter and high torque transmissibility.

Next, when the above-mentioned tubular body T is used as an endoscope,
The tubular body T of the present invention is used for most of the body insertion portion to insert, for example, an image guide and a light guide therein and a pulling wire. This wire can be inserted in a bare state, and the flat plate close-wound coil 1 withstands a reaction force against the tensile force of the wire-compression force. Then, at the tip of the tubular body, for example, a swinging tubular body having a large flexibility, which is composed of a gap winding coil and a resin tube externally fitted to the gap winding, is connected, and an objective lens is fixed to the tip to fix the internal lens. The image may be connected to the image guide and the tip of the wire may be fixed to the tip.

Although the wire swings in only one direction, as described above, since the tubular body T of the present invention has sufficient torque transmissibility, it can be rotated 360 ° by an external hand operation. That is, there is an advantage that a three-dimensional view can be secured.

In addition, if applied to a catheter, a curved part is formed at the tip of the catheter, and when inserting into the body-in various thin tubes of a living body-the direction of this curved part of the tip is changed by an external hand operation. It has the advantage that it can be inserted smoothly.

〔The invention's effect〕

The present invention has the above-mentioned structure, which has been considered to be difficult or impossible in the past, and has a sufficiently strong and torque-transmitting property, but has an extremely small wall thickness-for example, 0.2 mm or less-and an outer diameter D. A very thin ultra-fine medical tube-for example, 0.2 mm or less-can be obtained, which can be used as a catheter or an endoscope to alleviate the patient's pain and enable the diagnosis and treatment of previously impossible body parts. .

[Brief description of drawings]

FIG. 1 is an enlarged perspective view showing an embodiment of the present invention, and FIGS. 2, 3, and 4 are enlarged cross-sectional views of a main part thereof. 1 ... Flat plate closely wound coil, 2 ... Rectangular braid, 3 ... Resin coating layer.

Claims (1)

(57) [Claims] 1. A medical tubular body comprising a metal flat-plate close-wound coil, a metal rectangular braid externally fitted to the coil, and a resin coating layer coated thereon.