Resin-coated wire and chemical injection device

Abstract

To reduce a risk of administering a bubble together with chemical liquid to an affected part.SOLUTION: A resin coating wire capable of pushing out chemical liquid from the tip of a catheter by advancing in chemical liquid housing lumen of the catheter for housing the chemical liquid, includes a wire, and a resin coating part for coating the wire. The coating part has a tip side coating part and a proximal end side coating part. The tip side coating part is formed of a first resin material, and coats a first part which is a tip part of the wire. The proximal end side coating part is formed of a second resin material, and coats a second part adjacent to the proximal end side to the first part of the wire. The first resin material has higher affinity to water than the second resin material.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a resin-coated wire and a chemical solution injection device. [Background technology]

[0002] A known drug solution injection device for injecting a drug solution into a patient's body has an inner tube with a puncture needle at its tip inserted into the hollow portion of an outer tube, and injects a drug solution from the puncture needle into the patient's body via the hollow portion of the inner tube (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-172842 A Summary of the Invention [Problem to be solved by the invention]

[0004] Another type of drug solution injector is one that can eject a predetermined amount of drug solution from the tip of a catheter by advancing a wire a predetermined distance within the drug solution-containing lumen of the catheter that contains the drug solution. This type of drug solution injector can precisely control the amount of drug solution ejected and reduce loss of drug solution.

[0005] However, with a drug solution injection device configured as described above, there is a problem in that if air bubbles become mixed into the drug solution contained in the drug solution containing lumen of the catheter, there is a risk that the air bubbles will be administered to the affected area along with the drug solution.

[0006] This specification discloses a technique that can solve the above-mentioned problems. [Means for solving the problem]

[0007] The technology disclosed in this specification can be realized, for example, in the following forms.

[0008] (1) The resin-coated wire disclosed in this specification is a resin-coated wire that can push a medicinal solution from the tip of a catheter by advancing in a medicinal solution-containing lumen of the catheter in which the medicinal solution is contained. The resin-coated wire comprises a wire and a resin coating that coats the wire. The coating has a distal coating and a proximal coating. The distal coating is formed of a first resin material and coats a first portion that is the distal portion of the wire. The proximal coating is formed of a second resin material and coats a second portion of the wire adjacent to the proximal side of the first portion. The first resin material has a higher affinity for water than the second resin material.

[0009] Thus, in this resin-coated wire, the resin material for forming the distal covering portion has a higher affinity for water than the resin material for forming the proximal covering portion. That is, air bubbles in water (in the drug solution) tend to spread and adhere to the surface of the proximal covering portion, whereas the air bubbles are less likely to spread and adhere to the surface of the distal covering portion. Therefore, even if air bubbles are mixed into the drug solution contained in the drug solution-containing lumen of the catheter, the air bubbles can be moved relatively from the position of the distal covering portion to the position of the proximal covering portion by advancing the resin-coated wire, and adhere to the proximal covering portion, thereby preventing the air bubbles from flowing to the distal side. Therefore, according to this resin-coated wire, it is possible to reduce the risk of administering air bubbles to the affected area together with the drug solution when pushing the drug solution out of the tip of the catheter using the resin-coated wire.

[0010] (2) In the above resin-coated wire, the wire may be a rope wire formed by winding a plurality of thin wires in a spiral shape. This resin-coated wire can improve the flexibility of the resin-coated wire, and can easily advance the resin-coated wire in the drug solution-containing lumen of the catheter even if the catheter is bent, thereby improving the operability of the resin-coated wire and the accuracy of drug solution injection using the resin-coated wire.

[0011] (3) In the above resin-coated wire, each of the plurality of fine wires may be a stranded wire formed by helically winding a plurality of wires. This resin-coated wire can effectively improve the flexibility of the resin-coated wire, and can be easily advanced in the drug solution-containing lumen of the catheter even if the catheter is bent, thereby effectively improving the operability of the resin-coated wire and the accuracy of drug solution injection using the resin-coated wire.

[0012] (4) In the above resin-coated wire, a part of the distal end side of the second portion of the wire may be impregnated with the first resin material. With this resin-coated wire, for example, it is possible to effectively reduce loss of a drug solution due to the penetration of the drug solution into the inside of the wire from the boundary between the base end side covering portion and the distal end side covering portion. In addition, with this resin-coated wire, it is possible to avoid a sudden change in the rigidity of the wire (and thus the rigidity of the resin-coated wire) from the tip of the wire to the base end side, and it is possible to improve the operability of the resin-coated wire and the accuracy of drug solution injection by the resin-coated wire.

[0013] (5) In the above resin-coated wire, the most distal end portion of the resin-coated wire may be configured to have a generally hemispherical shape that is convex toward the distal end. With this resin-coated wire, the resin-coated wire can be advanced more easily within the drug solution-containing lumen of the catheter even if the catheter is bent, and the operability of the resin-coated wire and the drug solution injection accuracy using the resin-coated wire can be effectively improved.

[0014] (6) In the above resin-coated wire, the resin-coated wire may have a most distal portion, a tapered intermediate portion adjacent to the most distal portion on the proximal side and having an outer diameter that decreases toward the tip, and a proximal portion adjacent to the proximal side of the intermediate portion and having a substantially constant outer diameter. With this resin-coated wire, the tapered intermediate portion makes it easier to advance the resin-coated wire within the drug solution-containing lumen of the catheter even if the catheter is bent, and effectively improves the operability of the resin-coated wire and the accuracy of drug solution injection using the resin-coated wire.

[0015] (7) In the above resin-coated wire, the rigidity of the portion of the resin-coated wire constituted by the first portion may be higher than the rigidity of the portion of the wire constituted by the second portion. With this resin-coated wire, it is possible to reduce the risk that the distal end of the resin-coated wire will be deformed or retracted due to pressure from the drug solution when the resin-coated wire is advanced within the drug solution-containing lumen of the catheter, and it is possible to effectively improve the operability of the resin-coated wire and the accuracy of drug solution injection using the resin-coated wire.

[0016] (8) A liquid injection device disclosed in this specification includes the resin-coated wire and a catheter, thereby improving the operability and liquid injection accuracy of the liquid injection device.

[0017] The technology disclosed in this specification can be realized in various forms, such as a resin-coated wire, a chemical injection device including a resin-coated wire, a system including a chemical injection device, a method of manufacturing such a device or system, etc. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is an explanatory diagram illustrating a schematic configuration of a chemical liquid injector 100 according to an embodiment of the present invention. [Diagram 2] FIG. 1 is an explanatory diagram showing a detailed configuration of a resin-coated wire 20. [Diagram 3] FIG. 1 is an explanatory diagram showing a detailed configuration of a resin-coated wire 20. [Figure 4] FIG. 1 is an explanatory diagram showing a detailed configuration of a resin-coated wire 20. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] A. Embodiment: A-1. Configuration of chemical solution injector 100: FIG. 1 is an explanatory diagram that shows a schematic configuration of the liquid injection device 100 in this embodiment. FIG. 1 shows a longitudinal section (YZ section) of the liquid injection device 100. In FIG. 1, the positive Z-axis direction side is the tip end (distal side) that is inserted into the body, and the negative Z-axis direction side is the base end (proximal side) that is operated by a technician such as a doctor. In FIG. 1, some components of the liquid injection device 100 are not shown or are shown diagrammatically. This also applies to the subsequent figures. In this specification, the tip end of the liquid injection device 100 and its components are referred to as the "tip end", the tip end and its vicinity are referred to as the "tip portion", the base end end is referred to as the "base end", and the base end and its vicinity are referred to as the "base portion".

[0020] The liquid injection device 100 is a medical device used to inject a liquid medicine into a patient's body using a catheter that can be inserted into a biological lumen. Here, the biological lumen includes various lumen such as the blood vessel system, lymphatic system, biliary system, urinary system, respiratory system, digestive system, secretory glands, and reproductive organs. The liquid injection device 100 includes a needle catheter 10, a resin-coated wire 20, and a controller 30.

[0021] The needle catheter 10 is a member that is inserted into a patient's biological lumen through, for example, a channel of an endoscope, and is used to transport a medicinal liquid to a desired position in the patient's body and inject the medicinal liquid into the desired position. The needle catheter 10 includes a catheter shaft 12 and a needle portion 14. The catheter shaft 12 is a long member extending along a central axis AX. More specifically, the catheter shaft 12 is a substantially cylindrical member having openings at the tip and base ends, and a lumen 16 formed inside that communicates with the two openings. In FIG. 1, the central axis AX of the catheter shaft 12 is shown as being linear and parallel to the Z-axis direction, but the catheter shaft 12 has flexibility to the extent that it can be curved. The needle portion 14 is attached to the tip of the catheter shaft 12 and is a hollow member having a lumen 18 formed therein that communicates with the lumen 16 of the catheter shaft 12. The lumen 16 of the catheter shaft 12 and the lumen 18 of the needle portion 14 function as a medicinal liquid containing lumen L that contains the medicinal liquid DS. The cross-sectional shape of the drug solution containing lumen L is, for example, a substantially circular shape having a substantially constant inner diameter. A needle tip for puncturing a drug solution injection site is formed at the tip of the needle portion 14. The needle catheter 10 is an example of a catheter as defined in the claims.

[0022] The catheter shaft 12 is preferably antithrombotic, flexible, and biocompatible, and may be made of, for example, a resin material or a metal material. Examples of resin materials for forming the catheter shaft 12 include polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin, and fluororesin. Examples of metal materials for forming the catheter shaft 12 include stainless steel such as SUS304, NiTi alloy, and cobalt chrome alloy. A coil or braid may be embedded in the thick wall of the catheter shaft 12 to improve at least some of the flexibility, torque transmission, pushability, kink resistance, blood vessel tracking, lesion passability, and operability. The catheter shaft 12 may be composed of multiple layers made of the same or different materials. The needle portion 14 is preferably antithrombotic and biocompatible, and may be made of, for example, stainless steel such as SUS304, NiTi alloy, and cobalt chrome alloy.

[0023] The resin-coated wire 20 is inserted into the drug solution-containing lumen L from the base end side of the needle catheter 10, and is a member for pushing the drug solution DS contained in the drug solution-containing lumen L to the tip side by advancing in the drug solution-containing lumen L, thereby discharging the drug solution DS from the tip of the needle part 14. The resin-coated wire 20 is a long member extending along the central axis AX. In FIG. 1, the central axis AX of the resin-coated wire 20 is shown as being linear and parallel to the Z-axis direction, but the resin-coated wire 20 has flexibility to the extent that it can be curved. The outer diameter of the resin-coated wire 20 (more specifically, the outer diameter of the base end side part P3 (FIG. 2) of the resin-coated wire 20 described later) is approximately the same as the inner diameter of the drug solution-containing lumen L formed in the needle catheter 10 (clearance: 100 μm or less). The configuration of the resin-coated wire 20 will be described in detail later.

[0024] The controller 30 is a device that includes, for example, a gear mechanism, rollers, a discharge operation unit, etc., and is capable of advancing the resin-coated wire 20 inserted into the medicinal solution-containing lumen L of the needle catheter 10 a predetermined distance. When the resin-coated wire 20 is fed a predetermined distance toward the tip side by the controller 30, the medicinal solution DS contained in the medicinal solution-containing lumen L of the needle catheter 10 is pushed toward the tip side by the resin-coated wire 20, and the medicinal solution DS equivalent to the volume of the advanced resin-coated wire 20 is discharged from the tip of the needle portion 14. By repeating such an operation a predetermined number of times, a predetermined amount of medicinal solution DS can be injected into the patient's body.

[0025] A-2. Detailed configuration of the resin-coated wire 20: Next, a detailed configuration of the resin-coated wire 20 will be described. Figures 2 to 4 are explanatory diagrams showing a detailed configuration of the resin-coated wire 20. Figure 2 shows the external configuration of a portion of the tip side of the resin-coated wire 20, Figure 3 shows a schematic configuration of a longitudinal section (YZ section) of the portion of the tip side of the resin-coated wire 20, and Figure 4 shows the configuration of a transverse section (XY section) of the resin-coated wire 20 at the position IV-IV in Figure 3.

[0026] 2 to 4, the resin-coated wire 20 has a wire 24 and a resin-made coating portion 27 that coats the wire 24. In this embodiment, the coating portion 27 is substantially transparent, and therefore, in FIG. 2, the coating portion 27 is indicated by a dashed line.

[0027] The wire 24 is a long member extending along the central axis AX. As shown in FIG. 4, in this embodiment, the wire 24 is a rope wire formed by helically winding a plurality of (seven) fine wires 240. In this embodiment, each of the plurality of fine wires 240 constituting the wire 24 is a stranded wire formed by helically winding a plurality of (seven) strands 242. The wire 24 is preferably antithrombotic, flexible, and biocompatible, and can be made of, for example, a metal material. As the metal material for forming the wire 24, for example, stainless steel such as SUS304, NiTi alloy, cobalt chromium alloy, etc. can be adopted.

[0028] As shown in FIG. 2 and FIG. 3, the wire 24 has a straight portion 21, a welded portion 23 located at the tip of the wire 24, and a tapered portion 22 connecting the straight portion 21 and the welded portion 23. The straight portion 21 is a portion having a substantially constant outer diameter. The outer diameter of the straight portion 21 is, for example, about 0.5 mm to 2.0 mm. In this embodiment, the straight portion 21 is continuous to the base end of the wire 24. The welded portion 23 is a portion where the thin wires 240 and the strands 242 constituting the wire 24 are joined by welding using a predetermined welding method (for example, YAG laser welding), and is a substantially hemispherical portion convex toward the tip side. The tapered portion 22 is a portion having a tapered shape in which the outer diameter becomes smaller toward the tip. The outer diameter of the base end of the tapered portion 22 is substantially the same as the outer diameter of the straight portion 21, and the outer diameter of the tip of the tapered portion 22 is substantially the same as the outer diameter of the base end of the welded portion 23. The cross-sectional shape at each position of wire 24 is, for example, approximately circular. Welded portion 23 and tapered portion 22 of wire 24 are an example of a first portion in the claims, and straight portion 21 of wire 24 is an example of a second portion in the claims.

[0029] In the following description, the resin-coated wire 20 is virtually divided into a plurality of portions along the central axis AX, and a portion including the welded portion 23 of the wire 24 is referred to as the most distal portion P1, a portion including the tapered portion 22 of the wire 24 is referred to as the intermediate portion P2, and a portion including the straight portion 21 of the wire 24 is referred to as the base end portion P3. Moreover, the most distal portion P1 and the intermediate portion P2 are collectively referred to as the tip side portion P4.

[0030] The coating 27 is a resin coating that coats the wire 24. The presence of the coating 27 imparts high slidability to the resin-coated wire 20 and reduces loss of the chemical solution DS due to penetration of the chemical solution DS into the inside of the wire 24 (gaps between the thin wires 240 and the strands 242).

[0031] The thickness of the coating portion 27 is, for example, about 0.1 mm to 0.2 mm. Therefore, the outer shape of the resin-coated wire 20 is approximately the same as the outer shape of the wire 24. That is, the outer shape of the most distal end portion P1 of the resin-coated wire 20 is approximately hemispherical and convex toward the distal end, similar to the outer shape of the welded portion 23 of the wire 24. The outer shape of the intermediate portion P2 adjacent to the proximal end side of the most distal end portion P1 is tapered such that the outer diameter decreases toward the distal end, similar to the outer shape of the tapered portion 22 of the wire 24. The outer shape of the proximal side portion P3 adjacent to the proximal end side of the intermediate portion P2 is a straight shape with an approximately constant outer shape, similar to the outer shape of the straight portion 21 of the wire 24.

[0032] The covering portion 27 has a distal covering portion 25 and a proximal covering portion 26. The distal covering portion 25 covers the welded portion 23 and the tapered portion 22 of the wire 24. That is, the distal covering portion 25 constitutes the distal portion P4 of the resin-coated wire 20. The proximal covering portion 26 covers the straight portion 21 of the wire 24. That is, the proximal covering portion 26 constitutes the proximal portion P3 of the resin-coated wire 20.

[0033] The distal covering part 25 and the proximal covering part 26 are formed from different kinds of resin materials. More specifically, the resin material for forming the distal covering part 25 has a higher affinity for water than the resin material for forming the proximal covering part 26. An example of a combination of two resin materials that satisfies such a condition is a combination in which the resin material for forming the proximal covering part 26 is ETFE, PTFE, or PFA, and the resin material for forming the distal covering part 25 is acrylic urethane, polyethylene, or polyamide. Note that the drug solution targeted by the drug solution injector 100 of this embodiment (hereinafter referred to as the "target drug solution") contains a large amount of water because it is a drug dissolved in physiological saline. Therefore, the resin material for forming the distal covering part 25 has a higher affinity for the target drug solution than the resin material for forming the proximal covering part 26. The degree of affinity of a resin material for water can be expressed by a contact angle, and it can be said that the smaller the contact angle, the higher the affinity for water. The resin material for forming the distal covering portion 25 is an example of a first resin material in the claims, and the resin material for forming the proximal covering portion 26 is an example of a second resin material in the claims.

[0034] 3 and 4, in this embodiment, a resin material (e.g., acrylic urethane, polyethylene, or polyamide) for forming the tip side covering portion 25 is impregnated into a part of the tip side of the straight portion 21 of the wire 24 (hereinafter referred to as the "tip side straight portion 28"). That is, in the tip side straight portion 28, the resin material for forming the tip side covering portion 25 is present in the gaps 29 between the thin wires 240 and the wires 242 that constitute the wire 24.

[0035] In the resin-coated wire 20 of this embodiment, the tip side portion P4 has a welded portion 23 at which the thin wires 240 and the strands 242 constituting the wire 24 are joined together. In addition, at the tip side portion P4, the resin material constituting the tip side covering portion 25 seeps into the spaces between the thin wires 240 and the strands 242 constituting the wire 24, thereby bonding the thin wires 240 and the strands 242 together. Therefore, the rigidity of the tip side portion P4 of the resin-coated wire 20 (portion formed by the welded portion 23 and the tapered portion 22 of the wire 24) is higher than the rigidity of the base side portion P3 (portion formed by the straight portion 21 of the wire 24).

[0036] A-3. Manufacturing method of resin-coated wire 20: A method for manufacturing the resin-coated wire 20 constituting the chemical solution injector 100 of this embodiment is, for example, as follows. First, a rope wire (material for forming the wire 24) entirely coated with the base-end coating portion 26 is prepared. The portion of this rope wire that will eventually become the tapered portion 22 of the wire 24 has been processed in advance into a tapered shape.

[0037] Next, the base-end covering portion 26 of the rope wire is stripped from the portion that will eventually become the tapered portion 22 and the welded portion 23 of the wire 24. As a result, the base-end covering portion 26 covers only the portion that will eventually become the straight portion 21 of the wire 24, and the portions that will eventually become the tapered portion 22 and the welded portion 23 of the wire 24 are exposed.

[0038] Next, the most distal end of the rope wire is welded in the axial direction, for example by YAG laser welding, to form a welded portion 23. This forms a wire 24 having a straight portion 21, a tapered portion 22, and a welded portion 23.

[0039] Next, a material (adhesive) for forming the tip side covering portion 25 is applied to the portion of the rope wire from which the base side covering portion 26 has been peeled off. This forms the tip side covering portion 25 that covers the tapered portion 22 and the welded portion 23 of the wire 24. Also, the material for forming the tip side covering portion 25 permeates the tip side straight portion 28 of the straight portion 21 of the wire 24, and bonds the thin wires 240 and the strands 242 that make up the wire 24. The resin-coated wire 20 of this embodiment can be manufactured by the above steps.

[0040] A-4. Advantages of this embodiment: As described above, the drug solution injector 100 of this embodiment includes the resin-coated wire 20 that can push out the drug solution DS from the tip of the needle catheter 10 by advancing in the drug solution-containing lumen L of the needle catheter 10 in which the drug solution DS is contained. The resin-coated wire 20 includes the wire 24 and a resin-made covering portion 27 that covers the wire. The covering portion 27 has a distal covering portion 25 and a proximal covering portion 26. The distal covering portion 25 covers the distal end portion (welded portion 23 and tapered portion 22) of the wire 24. The proximal covering portion 26 covers the portion (straight portion 21) of the wire 24 adjacent to the proximal side of the distal end portion (welded portion 23 and tapered portion 22). The resin material for forming the distal covering portion 25 has a higher affinity for water than the resin material for forming the proximal covering portion 26.

[0041] Thus, in the resin-coated wire 20 of this embodiment, the resin material for forming the distal covering portion 25 has a higher affinity for water than the resin material for forming the proximal covering portion 26. That is, on the surface of the proximal covering portion 26, air bubbles in water (in the drug solution DS) tend to spread and adhere easily, whereas on the surface of the distal covering portion 25, the air bubbles are less likely to spread and adhere easily. Therefore, even if air bubbles are mixed into the drug solution DS contained in the drug solution-containing lumen L of the needle catheter 10, the air bubbles can be prevented from flowing to the distal side by moving the resin-coated wire 20 forward so that the air bubbles move relatively from the position of the distal covering portion 25 to the position of the proximal covering portion 26 and adhere to the proximal covering portion 26. Therefore, according to the resin-coated wire 20 of this embodiment, when the drug solution DS is pushed out from the tip of the needle catheter 10 using the resin-coated wire 20, the risk of administering air bubbles to the affected area together with the drug solution DS can be reduced.

[0042] In the resin-coated wire 20 of this embodiment, the wire 24 is a rope wire formed by spirally winding a plurality of thin wires 240. Therefore, according to the resin-coated wire 20 of this embodiment, the flexibility of the resin-coated wire 20 can be improved, and even if the needle catheter 10 is bent, the resin-coated wire 20 can be easily advanced within the drug solution-containing lumen L of the needle catheter 10, thereby improving the operability of the resin-coated wire 20 and the accuracy of drug solution injection by the resin-coated wire 20.

[0043] Furthermore, in the resin-coated wire 20 of this embodiment, each of the multiple fine wires 240 constituting the wire 24 is a stranded wire formed by helically winding multiple strands 242. Therefore, according to the resin-coated wire 20 of this embodiment, the flexibility of the resin-coated wire 20 can be effectively improved, and even if the needle catheter 10 is bent, the resin-coated wire 20 can be moved forward more easily within the drug solution-containing lumen L of the needle catheter 10, and the operability of the resin-coated wire 20 and the drug solution injection accuracy by the resin-coated wire 20 can be effectively improved.

[0044] In the resin-coated wire 20 of this embodiment, the distal straight portion 28, which is a portion of the distal side of the straight portion 21 of the wire 24, is permeated with a resin material for forming the distal covering portion 25. Therefore, the resin-coated wire 20 of this embodiment can effectively reduce loss of the chemical solution DS due to penetration of the chemical solution DS into the inside of the wire 24 from the boundary between the base covering portion 26 and the distal covering portion 25. In addition, the resin-coated wire 20 of this embodiment can avoid a sudden change in the rigidity of the wire 24 (and thus the rigidity of the resin-coated wire 20) from the tip of the wire 24 toward the base end, thereby improving the operability of the resin-coated wire 20 and the accuracy of chemical solution injection by the resin-coated wire 20.

[0045] Furthermore, in the resin-coated wire 20 of this embodiment, the most distal end portion P1 of the resin-coated wire 20 has a generally hemispherical shape that is convex toward the distal end. Therefore, according to the resin-coated wire 20 of this embodiment, even if the needle catheter 10 is bent, the resin-coated wire 20 can be moved forward more easily within the drug solution-containing lumen L of the needle catheter 10, and the operability of the resin-coated wire 20 and the drug solution injection accuracy by the resin-coated wire 20 can be effectively improved.

[0046] Moreover, the resin-coated wire 20 of this embodiment has a most distal portion P1, an intermediate portion P2 adjacent to the most distal portion P1 on the proximal side and having a tapered shape with an outer diameter decreasing toward the tip, and a proximal side portion P3 adjacent to the intermediate portion P2 on the proximal side and having a substantially constant outer diameter. Therefore, according to the resin-coated wire 20 of this embodiment, the tapered intermediate portion P2 makes it possible to further easily advance the resin-coated wire 20 within the drug solution-containing lumen L of the needle catheter 10 even if the needle catheter 10 is bent, and the operability of the resin-coated wire 20 and the drug solution injection accuracy by the resin-coated wire 20 can be effectively improved.

[0047] Furthermore, in the resin-coated wire 20 of this embodiment, the rigidity of the tip side portion P4 (portion formed by the welded portion 23 and tapered portion 22 of the wire 24) is higher than the rigidity of the base side portion P3 (portion formed by the straight portion 21 of the wire 24). Therefore, according to the resin-coated wire 20 of this embodiment, when the resin-coated wire 20 is advanced within the drug solution-containing lumen L of the needle catheter 10, the risk that the tip side of the resin-coated wire 20 will be deformed or retracted due to pressure from the drug solution DS can be reduced, and the operability of the resin-coated wire 20 and the drug solution injection accuracy by the resin-coated wire 20 can be effectively improved.

[0048] Moreover, the liquid injector 100 of the present embodiment includes the resin-coated wire 20 having the above-described configuration and the needle catheter 10. Therefore, according to the liquid injector 100 of the present embodiment, the operability of the liquid injector 100 and the liquid injection accuracy can be improved.

[0049] B. Variations: The technology disclosed in this specification is not limited to the above-described embodiments, and can be modified in various forms without departing from the spirit of the invention. For example, the following modifications are also possible.

[0050] The configuration of the chemical liquid injector 100 in the above embodiment is merely an example and can be modified in various ways. For example, in the above embodiment, the wire 24 is composed of the welded portion 23, the tapered portion 22, and the straight portion 21, but other portions may be present on the proximal end side of the straight portion 21. In addition, the wire 24 does not have to have the welded portion 23 and / or the tapered portion 22.

[0051] In the above embodiment, each of the multiple fine wires 240 constituting the wire 24 is a stranded wire formed by helically winding multiple strands 242, but each of the multiple fine wires 240 constituting the wire 24 may be composed of a single strand. Also, in the above embodiment, the wire 24 is a rope wire formed by helically winding multiple fine wires 240, but the wire 24 may be composed of a single strand.

[0052] In the above embodiment, the distal covering portion 25 of the covering portion 27 covers the welded portion 23 and the tapered portion 22 of the wire 24, and the proximal covering portion 26 covers the straight portion 21 of the wire 24, but the configuration of the covering portion 27 is not limited to this. For example, the distal covering portion 25 may cover the welded portion 23 and a portion of the distal side of the tapered portion 22, and the proximal covering portion 26 may cover a portion of the proximal side of the tapered portion 22 and the straight portion 21. Alternatively, the distal covering portion 25 may cover the welded portion 23, the tapered portion 22, and a portion of the distal side of the straight portion 21, and the proximal covering portion 26 may cover a portion of the proximal side of the straight portion 21.

[0053] The materials used for forming the components of the liquid injector 100 in the above embodiment are merely examples and may be modified in various ways. Also, the method for manufacturing the resin-coated wire 20 constituting the liquid injector 100 in the above embodiment is merely an example and may be modified in various ways. [Explanation of symbols]

[0054] 10: Needle catheter 12: Catheter shaft 14: Needle section 16: Lumen 18: Lumen 20: Resin-coated wire 21: Straight section 22: Tapered section 23: Welded section 24: Wire 25: Tip-side coated section 26: Base-side coated section 27: Coating section 28: Tip-side straight section 29: Gap 30: Controller 100: Drug injector 240: Thin wire 242: Wire AX: Central axis DS: Drug solution L: Drug solution storage lumen P1: Most distal section P2: Intermediate section P3: Base-side section P4: Tip-side section

Claims

1. A resin-coated wire capable of pushing out a medicinal solution from a distal end of a catheter by advancing in a medicinal solution-containing lumen of the catheter, A wire, a resin coating portion that coats the wire; Equipped with The covering portion is a tip side covering portion formed of a first resin material and covering a first portion which is a tip portion of the wire; a proximal covering portion formed of a second resin material and covering a second portion of the wire adjacent to a proximal side of the first portion; having the first resin material has a higher affinity for water than the second resin material; The wire is a rope wire formed by winding a plurality of thin wires in a spiral shape, a part of a tip side of the second portion of the wire is permeated with the first resin material; Resin coated wire.

2. The resin-coated wire according to claim 1, Each of the plurality of fine wires is a stranded wire formed by helically winding a plurality of wires. Resin coated wire.

3. The resin-coated wire according to claim 1 or 2, The tip end of the resin-coated wire has a generally hemispherical shape convex toward the tip end. Resin coated wire.

4. The resin-coated wire according to any one of claims 1 to 3, The resin-coated wire is The cutting edge and an intermediate portion adjacent to the most distal portion on the base end side and having a tapered shape in which the outer diameter decreases toward the tip; a base end portion adjacent to the intermediate portion on the base end side and having a substantially constant outer diameter; having Resin coated wire.

5. The resin-coated wire according to any one of claims 1 to 4, The rigidity of the portion of the resin-coated wire constituted by the first portion is higher than the rigidity of the portion of the wire constituted by the second portion. Resin coated wire.

6. The resin-coated wire according to any one of claims 1 to 5, The catheter; A drug solution injection device comprising:

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