JPH0341189B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a medical tube used when injecting a contrast medium into, for example, the pancreas or bile duct.

The method of injecting a contrast medium into the pancreas and bile ducts and performing X-ray photography is extremely important for the diagnosis of the pancreas and bile ducts. In this case, the method of injecting the contrast medium into the pancreas and bile duct is to orally guide the contrast medium injection tube into the duodenum through the insertion channel of the endoscope, and then insert the tip of the contrast medium injection tube into the nipple. The device is inserted into the pancreas and bile duct from the front, and a contrast agent is injected. However, since the pancreas and bile ducts, especially the bile ducts, run upwards, when inserting a medical tube, the tip of the endoscope is pressed against the endoscope's forceps elevator and squeezed, causing the tube to bend. , it cannot be inserted unless it is aligned with the direction of travel of the bile duct. Therefore,
Conventional contrast medium injection tubes are made of synthetic resin such as Teflon, which is relatively easily bent.

By the way, since the direction of travel of the biliary and pancreatic ducts usually differs for each case, it is necessary to create a curve at the tip of the tube that is suitable for each case. In addition, if the tube is left with a large bend, it is difficult to insert the tube into the insertion channel of the endoscope. Therefore, after each case treatment was completed, the tube was manually squeezed to remove any curls and straighten it. However, because of the tube shape and the material that tends to bend, it was not easy to remove.

The present invention has been made focusing on the above circumstances,
The purpose is to provide a tube for contrast medium injection that can reliably remove the curl at the tip of the tube by a simple method and has improved operability.

Hereinafter, one embodiment of the present invention will be described based on FIGS. 1 to 6.

1 in Figure 1 is the tube, and this tube 1 is made of a harmless synthetic resin with a small coefficient of friction, such as polyamide, tetrafluoroethylene, or a copolymer of tetrafluoroethylene and hexafluoropropylene. It is formed as follows. A cylindrical base 2 is coaxially attached and fixed to the base end of the tube 1. An injection port 4 having an injection hole 3 communicating with the tube 1 through the internal hollow part of the cap 2 is provided on the side surface of the cap 2 . Also, base 2
A knob 7 of a core body 6 is detachably attached to the rear end opening 5. The above core body 6
is made of a relatively rigid material such as synthetic resin, and the knob 7 is adhesively fixed to the rear end thereof. The core body 6 is inserted into the tube 1 through the base 2, but a gap is formed between the core body 6 and the inner surface of the tube 1, which is large enough to allow a contrast medium to flow, as will be described later. Further, the length of the core body 6 is set such that the tip thereof does not penetrate through the tube 1 and reaches near the rear end of the tip portion 1a. That is, the core body 6 is not located within the tip portion 1a of the tube 1. Therefore, the distal end portion 1a can be easily and freely bent, and the bent state has a kink.

Furthermore, within the thickness of the tip 1a of the tube 1, a plurality of linear biasing members 8 are embedded along the longitudinal direction of the tube 1, as shown in FIGS. 2 and 4. There is. Each of the biasing members 8 is made of a shape memory alloy, such as a Cu-Zu-Al alloy or a Ti-Ni alloy. The biasing member 8 becomes straight when the shape memory alloy is the matrix phase (high temperature phase), and even if the tip 1a is curved, it biases it straight. . Furthermore, when an external force is applied to plastically deform the material at room temperature (body temperature), martensitic transformation occurs and a martensitic phase is formed. Further, a material is used in which the temperature Af at which the reverse transformation from the martensitic phase to the parent phase ends is higher than body temperature, for example, 50°C.

Next, how to use the above embodiment will be explained.

First, the tube 1 is guided into the descending duodenum 13 through the insertion channel 15 of the endoscope 14, which has been introduced into the duodenum descending leg 13 in advance. Then, by using the forceps elevator 16 of the endoscope 14, etc., a bend is made to match the running direction of the bile duct 17 or pancreatic duct 18. After this, as shown in FIG.
Insert.

After it is inserted securely, a syringe or the like is connected to the injection port 5, and the contrast medium is press-fitted and injected. Next, after taking an X-ray, when the tube 1 is pulled out, the distal end 1a is bent and crooked as shown in Figure 6. 14 cannot be inserted into the insertion channel 15. In addition,
At this time, the shape memory alloy forming the biasing members 8 has a martensitic phase.

Therefore, the tip 1 of the tube 1 that was pulled out
When a is immersed in warm water or the like and heated to the reverse transformation end temperature Af of the shape memory alloy, for example 50° C. or higher, the biasing member 8 made of the shape memory alloy is heated due to the shape memory effect. The tip portion 1a is forced to become straight. Therefore, it becomes usable again.

FIGS. 7 and 8 show other embodiments of the present invention.

In this embodiment, a large-diameter inner hole 19 is formed in the tip 1a of the tube 1, and a coil-shaped biasing member 20 made of a shape memory alloy is fitted into the large-diameter inner hole 19. The shape memory alloy forming this biasing member 20 has a crystal structure in which the tip 1a of the tube 1 is straight as shown in FIG. As shown in Figure 2, as the shape memory alloy becomes bent due to the application of an external force, plastic deformation occurs in the shape memory alloy, and the outside of the coil portion is stretched, forming a martensitic phase and taking on a bent shape.

Therefore, when the distal end portion 1a is bent due to use, the biasing member 2 is
When heated, the stretched portion returns to its original state and is forcibly biased to become straight as shown in FIG.

As explained above, the present invention is provided with a biasing member made of a shape memory alloy that makes the tip of the tube substantially straight when heated. Therefore, simply by heating the tip of the tube with hot water, the bend in the tip can be removed. In this way, the curls on the tip can be removed quickly and reliably using a simple method.

[Brief explanation of the drawing]

Fig. 1 is an overall perspective view showing an embodiment of the present invention, Fig. 2 is a side sectional view of the vicinity of the distal end of the embodiment, and Fig. 3 is a side sectional view of the proximal portion of the embodiment. , FIG. 4 is a sectional view taken along the line - in FIG. 2, FIG. 5 is an explanatory diagram of the usage state of the embodiment, and FIG. 6 is the tip of the tube bent after use in the same embodiment. FIG. 7 is a side sectional view of the vicinity of the tip showing another embodiment of the present invention, and FIG. 8 is a side sectional view of the vicinity of the tip in a bent state in the same embodiment. It is. 1... Tube, 8... Biasing member, 14... Endoscope, 15... Channel for insertion, 17... Bile duct, 18... Pancreatic duct, 20... Biasing member, 1a...
tip.

Claims (1)

[Scope of Claims] 1. A medical tube, characterized in that a biasing member made of a shape memory alloy is provided at the tip of the tube to make the tip substantially straight when heated. 2. The medical tube according to claim 1, characterized in that a biasing member formed in a linear shape is embedded in the wall of the tip of the tube along the longitudinal direction of the tube. 3. The medical tube according to claim 1, wherein the biasing member is formed into a coil shape and installed in the inner hole at the tip end of the tube.