Medical devices

Abstract

This invention provides a medical device that can prevent fracture or delamination starting from the joint between the medical device and the marker. [Solution] The medical device (catheter 1) of this disclosure comprises a tubular body (inner sheath 2) formed from a resin r in a tubular shape. The inner sheath 2 has a marker region 11 formed by kneading an X-ray opaque material m into the resin r. The inner sheath 2 has a shaft portion 23 and a tapered portion 22 provided on the tip 23a side of the shaft portion 23, and the marker region 11 is provided on the shaft portion 23 and the tapered portion 22. The content c changes continuously in the marker region 11.

Description

[Technical Field]

[0001] The present disclosure relates to a medical device. [Background Art]

[0002] Conventionally, techniques for medical devices that are inserted into a living body such as blood vessels and digestive organs to treat lesions are known. A medical device is provided with a marker having X-ray visibility. A practitioner can confirm the position of the medical device from outside the body by X-ray fluoroscopy. For example, Patent Document 1 introduces an invention of a medical device in which a marker excellent in X-ray visibility is provided to improve visibility under X-ray fluoroscopy. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2019 / 176533 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] However, according to the invention of Patent Document 1, since a marker made of a material different from that of the medical device is joined to the medical device, there is a risk that breakage or peeling may occur starting from the joined portion.

[0005] Therefore, an object of the present disclosure is to provide a medical device capable of suppressing breakage or peeling starting from a joint portion between the medical device and a marker. [Means for Solving the Problem]

[0006] In order to solve the above problem, the medical device of the present disclosure includes a tubular body formed of resin into a tubular shape, the tubular body includes a marker region obtained by kneading a resin with a radiopaque material, and a content rate of the radiopaque material in the marker region continuously changes from a distal end toward a proximal end of the marker region. [Brief Description of Drawings]

[0007] [Figure 1] (a) an overall view of the medical device disclosed herein, and (b) an enlarged cross-sectional view of the inner sheath along line AA. [Figure 2] This is a schematic diagram showing the content of X-ray opaque materials in the marker region. [Figure 3] This is an explanatory diagram illustrating the manufacturing method of medical devices. [Modes for carrying out the invention]

[0008] Hereinafter, an embodiment of the medical device described herein, implemented as a catheter, will be described with reference to the drawings. In the following description, the left side of Figure 1 will be the tip side inserted into the body, and the right side will be the proximal end manipulated by a physician or other technician.

[0009] As shown in Figure 1(a), the catheter 1 of this disclosure comprises an inner sheath 2, an outer sheath 3 provided coaxially with the inner sheath 2, a needle 4 for perforating blood vessels, digestive organs, etc., and a connector 6 which is an operating part operated by a physician or other technician. In addition, a guide wire (not shown) may be used in conjunction with the catheter during the procedure.

[0010] As shown in Figure 1(b), the inner sheath 2 is a tubular body formed from resin r. The lumen 24 of the inner sheath 2 houses the needle 4, which is extended from the inner sheath 2 during treatment. The resin r can be polyamide, polyamide elastomer, polyolefin, polyester, polyester elastomer, etc.

[0011] The inner sheath 2 includes a shaft portion 23 and a tapered portion 22 provided on the tip 23a side of the shaft portion 23. The tapered portion 22 is tapered from the base end 22b side to the tip 22a side. The inner sheath 2 includes a marker region 11 made by kneading a powdered X-ray opaque material m. The X-ray opaque material m can be tungsten, barium sulfate, bismuth compounds, etc.

[0012] As shown in Figure 2, the content c of the X-ray opaque material m per unit volume in the marker region 11 changes continuously (gradually) from the tip 11a to the base 11b of the marker region 11. The change in content c is linked to the change in density of the marker region 11. The relationship between content c and density will be explained in detail below.

[0013] The content c represents the proportion of the X-ray opaque material m in the unit volume of the marker region 11. The marker region 11 is formed by uniformly mixing the X-ray opaque material m with the resin r, and the mixing ratio of the X-ray opaque material m is uniform throughout the entire marker region 11. On the other hand, the marker region 11 includes a compressed region (a region with a higher density than the surrounding area), and is configured so that the density changes continuously from the tip 11a to the base 11b. Therefore, the content c changes continuously (gradually) from the tip 11a to the base 11b of the marker region 11. The range of variation of the content c is approximately 20-65%.

[0014] As shown in Figure 2(a), the marker region 11 is provided in the shaft portion 23 and the tapered portion 22. The content c of the radiopaque material m increases continuously from the shaft portion 23 to the tapered portion 22. Specifically, the content c increases continuously from the base end 23b of the shaft portion 23 toward the tapered portion 22. The rate of increase of the content c is approximately 20-65%. By configuring the content c to increase continuously from the shaft portion 23 to the tapered portion 22, changes in physical properties at the boundary between the shaft portion 23 and the tapered portion 22 can be reduced, preventing fracture and delamination.

[0015] As shown in Figure 2(b), the inner sheath 2 can be configured to include a tip portion 21 provided on the tip 22a side of the tapered portion 22, in addition to the shaft portion 23 and the tapered portion 22. In this case, the marker region 11 is provided on the shaft portion 23, the tapered portion 22, and the tip portion 21. The content c decreases continuously from the tapered portion 22 to the tip portion 21. Specifically, the content c decreases continuously from the center of the tapered portion 22 towards the tip 21a of the tip portion 21. The rate of decrease in the content c is approximately 20-65%. The content c from the shaft portion 23 to the tapered portion 22 is the same as in Figure 2(a). Because the content c is configured to decrease continuously from the tapered portion 22 to the tip portion 21, changes in physical properties at the boundary between the tapered portion 22 and the tip portion 21 can be reduced, preventing fracture and peeling.

[0016] Next, the manufacturing method of the inner sheath 2 that constitutes the catheter 1 with the above configuration will be explained with reference to Figure 3.

[0017] First, as shown in Figure 3(a), the resin r is formed into a tubular shape, and the X-ray opaque material m is mixed into the resin r of the marker region 11 (shaft portion 23 and tapered portion 22). At this time, the content c of the X-ray opaque material m in the shaft portion 23 and tapered portion 22, which constitute the marker region 11, is uniform.

[0018] Next, the softening target area 12, which is part of the marker area 11, is softened. Here, as shown in Figure 3(b), the heater 7 is positioned to surround the tapered portion 22, which is the softening target area 12, and the tapered portion 22 is heated by the heater 7. The resin r of the tapered portion 22 is heated and melted, and as shown in Figure 3(c), the tapered portion 22 softens. At this time, the tip 23a of the shaft portion 23 also softens gradually due to heat transfer from the base end 22b of the tapered portion 22.

[0019] Subsequently, as shown in FIG. 3(d), the entire marker region 11 is compressed. Then, the tapered portion 22, which is the softening target region 12, is compressed at a higher compression rate than the shaft portion 23, which is a region other than the softening target region 12. As a result, as shown in FIG. 3(e), the content c of the radiopaque material m in the tapered portion 22 becomes higher than the content c of the radiopaque material m in the shaft portion 23. At this time, since the distal end 23a of the shaft portion 23 is also gradually softened, the content c of the radiopaque material m decreases continuously from the tapered portion 22 toward the shaft portion 23.

[0020] Therefore, according to the present disclosure, by kneading the radiopaque material m into the resin r, the marker region 11 and the inner sheath 2 are integrally molded, and a joint between the marker region 11 and the inner sheath 2 is eliminated. Therefore, there is no risk of fracture or peeling starting from the joint.

[0021] According to the present disclosure, since the content c is gradually decreased toward the proximal end 11b of the marker region 11, changes in physical properties at the proximal end 11b of the marker region 11 can be reduced, and fracture and peeling can be prevented.

[0022] X-ray visibility improves as the kneading amount (content c) of the radiopaque material m per unit volume increases. According to the present disclosure, the content c in the tapered region 22 is increased, thereby improving X-ray visibility.

[0023] Here, when the kneading ratio of the radiopaque material m to the resin r increases, there is a problem that the physical properties of the resin r decrease. Also in this respect, according to the present disclosure, since the kneading ratio of the radiopaque material m is uniform, a decrease in the physical properties of the resin r does not occur.

[0024] The present disclosure is not limited to the above-described embodiment, and can be implemented by appropriately changing the shape and configuration of each part without departing from the gist of the present disclosure.

Claims

1. It comprises a tubular body formed from resin in a tubular shape, The tubular body includes a marker region formed by kneading an X-ray opaque material into the resin, A medical device characterized in that the content of the X-ray opaque material in the marker region changes continuously from the leading edge to the proximal end of the marker region.

2. The tubular body includes a shaft portion and a tapered portion provided at the tip of the shaft portion. The marker region is provided in the shaft portion and the tapered portion, The medical device according to claim 1, wherein the content increases continuously from the shaft portion toward the tapered portion.

3. The tubular body includes a tip portion provided on the tip side of the tapered portion, The marker region is provided at the tip portion, The medical device according to claim 2, wherein the content decreases continuously from the tapered portion to the tip portion.

4. It comprises a tubular body formed from resin in a tubular shape, A method for manufacturing a medical device, wherein the tubular body includes a marker region formed by kneading an X-ray opaque material into the resin, A step of softening the softening target region, which is a part of the marker region, The process includes compressing the entire marker region, A method for manufacturing a medical device, characterized in that, in the compression step, the area to be softened is compressed at a higher compression ratio than the area other than the area to be softened.

5. The method for manufacturing a medical device according to claim 4, wherein the softening step includes a step of heating the area to be softened.

6. The tubular body includes a shaft portion and a tapered portion provided at the tip of the shaft portion. The marker region is provided on the shaft portion and the tapered portion. The softening region is provided in the tapered portion, as described in claim 4 or 5, for the method of manufacturing a medical device.

7. The tubular body includes a tip portion provided on the tip side of the tapered portion, The marker region is provided at the tip portion, as described in claim 6 for the method of manufacturing a medical device.

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