Guidewire

Abstract

To enhance the mechanical strength of a guide wire including a sound source, and excellently irradiate the periphery of the guide wire with supersonic waves.SOLUTION: A guide wire 100 includes a core shaft 10, a coil part 12, a sound source 16 and a wiring 14. The coil part 12 is joined to the tip of the core shaft 10 and spirally goes around the periphery of the core shaft 10 toward the rear side. The coil part 12 has an opening part 26 in which an interval between strands 18 forming itself is larger compared to the other parts. The sound source 16 is disposed inside the opening part 26. The wiring 14 extends along the extension direction of the core shaft 10, and the tip of the wiring 14 is positioned inside the coil part 12. The wiring 14 supplies energy to the sound source 16.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a guidewire, and more particularly to a guidewire having a helical coil portion at its distal end. [Background technology]

[0002] A procedure is performed in which a guidewire is inserted into a patient's blood vessel, and a tubular catheter is inserted through the guidewire. After the catheter is inserted into the blood vessel, the guidewire is withdrawn from the catheter, and a drug is injected or a procedure using a wire-like medical device is performed through the catheter.

[0003] In general, guidewires are structurally designed to facilitate procedures. For example, the guidewires described in the following Patent Documents 1 to 3 have a spiral coil portion at their tip. The coil portion makes it easier to move the tip of the guidewire along a blood vessel. The guidewire described in Patent Document 1 has a sound source attached to the tip of the coil portion. The position of the tip of the guidewire is determined by detecting ultrasound waves generated from the sound source with an ultrasound diagnostic device. The guidewire inside the blood vessel is generally observed with an X-ray imaging device, but in cases where it is not possible to inject a contrast agent into the blood vessel, it may be observed with ultrasound, as described in Patent Document 1. The guidewire described in Patent Document 3 has a sensor attached near the coil portion. The sensor is placed inside the blood vessel by inserting the guidewire into the blood vessel. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-185363 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-279 [Patent Document 3] Japanese Patent Application Laid-Open No. 2015-96231 Summary of the Invention [Problem to be solved by the invention]

[0005] As described in Patent Document 1, when a sound source is attached to the tip of the coil, the mechanical strength of the guidewire may be reduced compared to a normal guidewire that does not have a sound source. This is because the sound source is a device intended to generate ultrasound waves and does not necessarily have a structure that makes the mechanical strength of the tip of the guidewire equivalent to that of a normal guidewire. Furthermore, if the sound source is located inside the coil, the propagation of the ultrasound generated by the sound source may be obstructed by the wire of the coil, preventing it from being sufficiently radiated around the guidewire, making it difficult to determine the position of the guidewire using the ultrasound generated by the sound source.

[0006] An object of the present invention is to increase the mechanical strength of a guide wire equipped with a sound source and to radiate ultrasonic waves well around the guide wire. [Means for solving the problem]

[0007] The guide wire according to the present invention comprises a core shaft, a coil portion connected to the distal end of the core shaft and spirally wound around the core shaft, and a guide wire provided inside the coil portion. generates ultrasonic waves a sound source, and the coil portion has an open portion where the spacing between the wires forming the coil portion is larger than that in other portions. The sound source is provided inside the open portion. It is characterized by the following.

[0009] Preferably, the coil portion has a bent shape that is bent in the longitudinal direction of the guide wire, and the open portion is formed in a range extending rearward from the bent portion of the coil portion.

[0010] Preferably, the acoustic transducer includes a wire extending along the extension direction of the core shaft, the tip of the wire being located inside the coil portion, and the wire supplies energy to the sound source.

[0011] Preferably, the coil portion has a bent shape bent in the longitudinal direction of the guide wire, and the tip of the wiring is located rearward of the bent portion of the coil portion.

[0012] Preferably, the wiring is an optical fiber, and the guide wire further includes a light absorber provided inside the coil portion, the light absorber forming the sound source.

[0013] Preferably, the wiring is a conductor, the sound source is a vibration element, and the vibration element is connected to the tip of the conductor.

[0014] The present invention also provides a light absorbing device comprising: a core shaft; a coil portion coupled to a tip portion of the core shaft and spirally wound around the core shaft; an optical fiber extending along an extension direction of the core shaft and having a tip portion located inside the coil portion; and a light absorber covering a surface of the coil portion, wherein the coil portion has an open portion in which the spacing between the strands forming the coil portion is larger than in other portions, and the tip portion of the optical fiber is located inside the open portion. The optical absorber generates an ultrasonic wave based on the energy of the light emitted from the optical fiber. It is characterized by:

[0015] Preferably, the coil portion has a bent shape bent in the longitudinal direction of the guide wire, and the tip of the optical fiber is located behind the bent portion of the coil portion.

[0016] Preferably, the coil portion has a bent shape that is bent in the longitudinal direction of the guide wire, and the open portion is formed in a range extending rearward from the bent portion of the coil portion.

[0017] Preferably, the gap between the wires in the open portion is 0.13 mm or more and 0.33 mm or less.

[0018] Preferably, the coil portion is filled with a resin. [Effects of the Invention]

[0019] According to the present invention, the mechanical strength of a guide wire equipped with a sound source can be increased, and ultrasonic waves can be efficiently emitted around the guide wire. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 2 is a diagram schematically illustrating a guide wire. [Figure 2] FIG. 2 is a diagram schematically illustrating an axial cross section of a guidewire. [Figure 3] FIG. 10 is a diagram showing experimental results of measuring ultrasonic sound pressure output laterally from a guidewire. [Figure 4] FIG. 10 is a diagram schematically showing an axial cross section of a guidewire according to a first modified example. [Figure 5] FIG. 10 is a diagram schematically showing an axial cross section of a guidewire according to a second modified example. DETAILED DESCRIPTION OF THE INVENTION

[0021] The present invention will be described with reference to the accompanying drawings, in which the same components shown in the drawings are designated by the same reference numerals and their description will be omitted.

[0022] FIG. 1 schematically illustrates a guidewire 100 according to an embodiment of the present invention. The guidewire 100 includes a core shaft 10, a coil portion 12, wiring 14, and a sound source 16. The core shaft 10 is formed of a known material and is straight. The coil portion 12 is formed by spirally winding a known metal wire 18. While the materials of the core shaft 10 and the wire 18 are not particularly limited, forming a portion of the coil portion 12 from an X-ray opaque metal material allows the position of the guidewire to be confirmed using an X-ray imaging device, similar to conventional guidewires. The tip of the coil portion 12 is connected to the tip of the core shaft 10, and the wire 18 of the coil portion 12 spirally wraps around the core shaft 10 toward the rear. The tip of the core shaft 10 and the tip of the coil portion 12 are connected by a tip joint 20. The tip joint 20 may be made of a rigid joint material, such as solder, stainless steel, iron, aluminum, copper, or other metal.

[0023] The rear end of the coil portion 12 is fixed to the core shaft 10 by a rear end joint portion 22. The rear end joint portion 22 is made of a fixing material such as plastic resin or solder. The rear end joint portion 22 does not necessarily have to be provided. In other words, the rear end of the coil portion 12 may be a free end that can swing freely in the front-rear direction or radial direction.

[0024] A bent portion 24 is formed near the distal end of the coil portion 12. The bent portion 24 is bent in a generally V-shape at a predetermined angle relative to the longitudinal direction of the guidewire 100. The bent portion 24 is provided, for example, to facilitate the surgeon's selection of one of two blood vessels branching at a vascular bifurcation through which to advance the guidewire 100. The coil portion 12 is formed with an open portion 26 in which the spacing between the wires 18 forming the coil portion 12 is greater than in other portions. In the open portion 26, the pitch of the helical structure formed by the wires 18 is greater than in other portions. In the example shown in FIG. 1 , the open portion 26 is formed in a range extending rearward from the bent portion 24. The open portion 26 may include the bent portion 24 or may be positioned forward of the bent portion 24.

[0025] Because the spacing between the wires 18 is larger in the open portion 26 than in other portions, it is easy to bend the portion adjacent to and in front of the open portion 26. In other words, the structure in which the open portion 26 is formed makes it easy to process (so-called shaping) the bent portion 24.

[0026] The wiring 14 is arranged alongside the core shaft 10 and extends from the rear to the front along the extension direction of the core shaft 10. The wiring 14 passes through the rear end coupling portion 22, and the tip of the wiring 14 is located inside the coil portion 12. The tip of the wiring 14 is located inside the open portion 26 behind the bent portion 24. A sound source 16 is provided at the tip of the wiring 14. The sound source 16 is provided at a position inside the open portion 26 in the inner region of the coil portion 12.

[0027] The sound source 16 generates ultrasonic waves using energy supplied through the wiring 14. The frequency range of the ultrasonic waves generated by the sound source 16 may be a range that can be detected by a medical ultrasonic diagnostic device or the like. The frequency range of the ultrasonic waves generated by the sound source 16 may be, for example, 1 MHz or more and 30 MHz or less, but is not limited to this range.

[0028] In this embodiment, the sound source 16 is a light absorber 16a that absorbs light, causing its temperature to rise and expand, and the wiring 14 is an optical fiber 14a. The optical fiber 14a supplies pulsed laser light to the light absorber 16a, which serves as the sound source 16. The light absorber 16a absorbs the energy of the pulsed laser light and generates ultrasonic waves due to adiabatic expansion caused by the energy.

[0029] The sound source 16 may be a vibration element 16b made of a piezoelectric material. In this case, a pair of conductors 14b is used for the wiring 14. The vibration element 16b is connected to the tips of the pair of conductors 14b, and the pair of conductors 14b apply a voltage having a pulsed time waveform to the vibration element 16b serving as the sound source 16. The vibration element 16b generates ultrasonic waves in response to the applied voltage.

[0030] FIG. 2 schematically shows a cross section (axial cross section) that appears when the guidewire 100 is cut along a plane parallel to the longitudinal direction. The inside of the coil portion 12 is filled with a resin 30 such as plastic. The core shaft 10, wiring 14, and sound source 16 are fixed inside the coil portion 12 by filling with the resin 30. While FIG. 2 shows an example in which the inside of the coil portion 12 is filled with the resin 30, the resin 30 may also be filled inside the coil portion 12 after the coil portion 12 has been molded from the outside. Filling the open portions 26 with the resin 30 maintains a constant gap d between the wires 18.

[0031] The outer diameter of the coil portion 12 may be, for example, 0.3 mm or more and 1.0 mm or less, but is not limited to this range. The gap d between the wires 18 in the open portion 26 may be, for example, 0.13 mm or more and 0.33 mm or less, but is not limited to this range. The diameter of the coil portion 12 and the gap d between the wires 18 in the open portion 26 may be determined depending on the ease of manipulation of the guidewire 100, the characteristics of the ultrasound emitted from the guidewire 100, and the like. Note that by setting the gap d to 0.33 mm or less, the mechanical load applied to the open portion 26 during the procedure is suppressed, and kinking, deformation, and the like are avoided.

[0032] FIG. 3 shows experimental results of measuring the ultrasonic sound pressure output laterally from the guidewire 100. The horizontal axis represents the gap d between the wires 18, and the vertical axis represents the normalized ultrasonic sound pressure (normalized ultrasonic sound pressure). The normalized ultrasonic sound pressure represents the percentage of the ultrasonic sound pressure emitted from the guidewire 100 relative to the ultrasonic sound pressure emitted from a single sound source 16 that is not disposed inside the coil portion 12. In the experimental results shown in FIG. 3, when the gap d between the wires 18 in the open portion 26 is 0.13 mm or greater, the normalized ultrasonic sound pressure is 50% or greater. Here, there are conditions under which the normalized ultrasonic sound pressure exceeds 100%, and this is because, by disposing the sound source 16 inside the coil portion 12, ultrasonic waves emitted in the axial direction of the wiring 14 are reflected by the coil structure and emitted laterally.

[0033] An example of a procedure using the guidewire 100 will be described. A tubular introducer is inserted into a patient's blood vessel from the surface of the skin, and the guidewire 100 is inserted into the blood vessel through the introducer. With the guidewire 100 inserted into the blood vessel, a tubular catheter is inserted into the blood vessel while the guidewire 100 is passed through the catheter. The guidewire 100 inside the blood vessel may be observed by an X-ray imaging device. However, in cases where it is not possible to inject a contrast agent into the blood vessel, the operator may confirm the position of the sound source 16 on the display of an ultrasound diagnostic device, as shown in Patent Document 1.

[0034] In the guidewire 100 according to this embodiment, the coil portion 12 is connected to the core shaft 10 by a distal joint 20. The distal joint 20 is formed of a rigid joint material such as metal. This securely fixes the coil portion 12 to the core shaft 10, and the mechanical strength of the distal end of the coil portion 12 is equivalent to that of a conventional guidewire not equipped with a sound source, and is improved compared to a guidewire equipped with a conventional sound source. The coil portion 12 also has a bent shape, with the distal region extending in a different direction from the region proximal to the bend 24. This makes it easier for the surgeon to select one of two blood vessels branching at a vascular bifurcation through which to advance the guidewire 100.

[0035] Furthermore, an open portion 26 is provided in the coil portion 12, and the sound source 16 is disposed inside the open portion 26. This reduces the proportion of ultrasonic waves emitted from the sound source 16 whose propagation is hindered by the wires 18 of the coil portion 12, thereby increasing the ultrasonic sound pressure emitted from the guidewire 100. Also, in the open portion 26, the gaps between the wires 18 are wider around the periphery of the coil portion 12 than in other portions. This allows ultrasonic waves to be emitted over a wide angular range as seen from the coil portion 12. Therefore, the ultrasonic waves emitted from the sound source 16 can be reliably detected by an ultrasound diagnostic device, making it easier for the surgeon to determine the position of the guidewire 100.

[0036] Additionally, the tip of the wiring 14 is located behind the bent portion 24 of the coil portion 12. This facilitates the process of forming the bent portion 24 after the sound source 16 is placed inside the coil portion 12. Furthermore, the mechanical load applied to the tip of the wiring 14 and the sound source 16 due to the bending of the bent portion 24 that occurs during use is suppressed.

[0037] FIG. 4 shows an axial cross-sectional view of a guidewire 102 according to a first modified example of the present invention. The guidewire 102 is configured by replacing the wiring 14 of the guidewire 100 shown in FIG. 2 with an optical fiber 14a, and filling the inside of the coil portion 12 with a light absorber 32. The guidewire 102 does not use a sound source 16 in the form of a device. The optical fiber 14a transmits a pulsed laser, which is emitted from the tip of the optical fiber 14a. A region of the light absorber 32 near the tip of the optical fiber 14a acts as a sound source. That is, the light absorber 32 near the tip of the optical fiber 14a adiabatically expands in response to the pulsed laser and generates ultrasound.

[0038] In the guidewire 102, a region near the tip of the optical fiber 14a within the region of the light absorber 32 filled inside the coil portion 12 is used as a sound source. The guidewire 102 can achieve the same effects as those achieved by the guidewire 100 of FIGS.

[0039] Fig. 5 shows an axial cross section of a guidewire 104 according to a second modified example of the present invention. In the guidewire 104, the wiring 14 of the guidewire 100 shown in Figs. 1 and 2 is replaced with optical fiber 14a, the sound source 16 in the form of a device is removed, and the surface of the coil portion 12 is covered with a light absorber 40. The light absorber 40 may be inserted into the inside of the coil portion 12 through gaps between the wires 18 that form the coil portion 12.

[0040] The optical fiber 14a transmits a pulsed laser beam, which is emitted from the tip of the optical fiber 14a. The pulsed laser beam is emitted from the tip of the optical fiber 14a from the inside of the coil portion 12 toward the outside. The pulsed laser beam is irradiated onto the light absorber 40 in the gaps between the wires 18 of the coil portion 12, and ultrasonic waves are emitted from the light absorber 40.

[0041] In the guidewire 104 according to this modification, an open portion 26 is provided in the coil portion 12, and the tip of the optical fiber 14a is located inside the open portion 26. With this structure, the proportion of the pulsed laser emitted from the optical fiber 14a that is impeded in its travel by the wires 18 of the coil portion 12 is reduced compared to when the open portion 26 is not provided. As a result, the ultrasonic sound pressure emitted by the guidewire 104 is increased compared to when the open portion 26 is not provided, and an effect similar to that of the guidewire 100 is obtained.

[0042] The above describes guidewires 100, 102, and 104 according to embodiments of the present invention. Guidewires according to the present invention may have the following configurations.

[0043] (Configuration 1) The guidewire includes a core shaft, a coil portion connected to the distal end of the core shaft and spiraling around the core shaft, and a sound source provided inside the coil portion, the coil portion having an open portion where the wires forming the coil portion are spaced apart more widely than in other portions. With this configuration, the sound source is disposed inside the coil portion and ultrasonic waves generated by the sound source are radiated around the guidewire through the open portion, thereby improving mechanical strength compared to guidewires equipped with conventional sound sources and enabling good radiation of ultrasonic waves around the guidewire.

[0044] (Configuration 2) In the guidewire according to Configuration 1, the sound source is provided inside the open portion. With this configuration, the propagation of ultrasonic waves emitted from the sound source is less likely to be obstructed by the wire of the coil portion, making it possible to more effectively radiate ultrasonic waves around the guidewire.

[0045] (Configuration 3) In the guidewire according to configuration 1 or 2, the coil portion has a bent shape bent relative to the longitudinal direction of the guidewire, and the open portion is formed in a range extending rearward from the bent portion of the coil portion. According to this configuration, providing the open portion in the coil portion makes it easier to bend the portion distal to the open portion into a predetermined shape.

[0046] (Configuration 4) A guide wire according to configuration 1 or 2, comprising a wiring extending along the extension direction of the core shaft, the tip of the wiring being positioned inside the coil portion, and the wiring supplying energy to the sound source.

[0047] (Configuration 5) In the guidewire according to configuration 4, the coil portion has a bent shape bent with respect to the longitudinal direction of the guidewire, and the tip of the wiring is located behind the bent portion of the coil portion. Because the tip of the wiring is located behind the bent portion, a mechanical load applied to the wiring due to flexure of the bent portion during a procedure is suppressed.

[0048] (Configuration 6) In the guidewire according to configuration 4 or 5, the wiring is an optical fiber, and the guidewire further includes a light absorber provided inside the coil portion, the light absorber forming the sound source. With this configuration, the light absorber functions as the sound source by absorbing pulsed laser light emitted from the tip of the optical fiber, so there is no need to incorporate a device such as a vibration element into the coil portion, and it is possible to reduce the diameter of the tip of the guidewire.

[0049] (Configuration 7) In the guide wire according to configuration 4 or 5, the wiring is a conductor, the sound source is a vibration element, and the vibration element is connected to a tip of the conductor.

[0050] (Configuration 8) The guidewire includes a core shaft, a coil portion coupled to the distal end of the core shaft and spirally wound around the core shaft, an optical fiber extending along the extension direction of the core shaft and having its distal end located inside the coil portion, and a light absorber covering the surface of the coil portion, wherein the coil portion has an open portion in which the spacing between the strands forming the coil portion is larger than in other portions, and the tip of the optical fiber is located inside the open portion. With this configuration, pulsed laser light emitted from the tip of the optical fiber is absorbed by the light absorber through the open portion, generating ultrasonic waves that are radiated around the guidewire. Therefore, compared to guidewires equipped with conventional sound sources, the guidewire has improved mechanical strength and can effectively radiate ultrasonic waves around the guidewire. Furthermore, because the tip of the optical fiber is located inside the open portion, the emitted pulsed laser light is less likely to be obstructed by the strands of the coil portion, allowing for more effective ultrasonic wave radiation.

[0051] (Configuration 9) In the guidewire according to configuration 8, the coil portion has a bent shape bent with respect to the longitudinal direction of the guidewire, and the tip of the optical fiber is located behind the bent portion of the coil portion. Because the tip of the optical fiber is located behind the bent portion, a mechanical load applied to the optical fiber due to bending of the bent portion during a procedure is suppressed.

[0052] (Configuration 10) In the guidewire according to configuration 8, the coil portion has a bent shape bent relative to the longitudinal direction of the guidewire, and the open portion is formed in a range extending rearward from the bent portion of the coil portion. According to this configuration, the provision of the open portion in the coil portion makes it easier to bend the portion distal to the open portion into a predetermined shape.

[0053] (Configuration 11) In the guidewire according to any one of configurations 1 to 10, the gap between the wires at the open portion is 0.13 mm or more and 0.33 mm or less. With this configuration, by making the gap 0.13 mm or more, the ultrasonic sound pressure radiated around the guidewire through the open portion can be maintained relatively high, enabling good ultrasonic radiation. Furthermore, by making the gap 0.33 mm or less, the mechanical load applied to the open portion during surgery can be suppressed.

[0054] (Configuration 12) The guidewire according to any one of configurations 1 to 11, further comprising a resin filled inside the coil portion. The filled resin can fix the position of the sound source or the tip of the optical fiber provided inside the coil portion, and can prevent a decrease in the radiation of ultrasound around the guidewire due to misalignment of the sound source or the tip of the optical fiber. [Explanation of symbols]

[0055] 10 core shaft, 12 coil portion, 14 wiring, 14a optical fiber, 14b conducting wire, 16 sound source, 16a, 32, 40 light absorber, 16b vibration element, 18 wire, 20 tip coupling portion, 22 rear end coupling portion, 24 bending portion, 26 open portion, 30 resin, 100, 102, 104 guide wire.

Claims

1. A core shaft; a coil portion coupled to a tip end portion of the core shaft and spirally wound around the core shaft; a sound source that is provided inside the coil portion and generates ultrasonic waves, The coil portion is The wires have an open portion where the wires are spaced apart from each other in a larger space than in other portions. The sound source is A guidewire characterized in that it is provided inside the opening.

2. 2. The guidewire of claim 1, The coil portion is The guide wire has a bent shape bent with respect to the longitudinal direction thereof, The opening is The guide wire is characterized in that it is formed in a range extending from the bent portion of the coil portion toward the rear.

3. 2. The guidewire of claim 1, Wiring extending along the extension direction of the core shaft, The tip of the wiring is located inside the coil portion, The guidewire is characterized in that the wiring supplies energy to the sound source.

4. 4. The guidewire according to claim 3, The coil portion is The guide wire has a bent shape bent with respect to the longitudinal direction thereof, The tip of the wiring is The guidewire is characterized in that it is located behind the bent portion of the coil portion.

5. 4. The guidewire according to claim 3, the wiring is an optical fiber, The guidewire further comprises: a light absorber provided inside the coil portion, A guidewire, characterized in that the sound source is formed by the light absorber.

6. 4. The guidewire according to claim 3, the wiring is a conductor, the sound source is a vibration element, The guidewire is characterized in that the vibration element is connected to the tip of the conductor.

7. A core shaft; a coil portion coupled to a tip end portion of the core shaft and spirally wound around the core shaft; an optical fiber extending along the extending direction of the core shaft and having a tip portion located inside the coil portion; a light absorber covering the surface of the coil portion, The coil portion is The wires have an open portion where the wires are spaced apart from each other in a larger space than in other portions. The tip of the optical fiber Located inside the opening, The light absorber is A guidewire characterized in that an ultrasonic wave is generated based on the energy of light emitted from the optical fiber.

8. 8. The guidewire of claim 7, The coil portion is The guide wire has a bent shape bent with respect to the longitudinal direction thereof, The tip of the optical fiber The guidewire is characterized in that it is located behind the bent portion of the coil portion.

9. 8. The guidewire of claim 7, The coil portion is The guide wire has a bent shape bent with respect to the longitudinal direction thereof, The opening is The guide wire is characterized in that it is formed in a range extending from the bent portion of the coil portion toward the rear.

10. 10. The guidewire according to any one of claims 1, 7, 8 and 9, A guidewire characterized in that the gap between the wires in the open portion is 0.13 mm or more and 0.33 mm or less.

11. 10. The guidewire according to any one of claims 1, 7, 8 and 9, A guidewire characterized in that a resin is filled inside the coil portion.

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