Optical fiber cable

Abstract

To restrict an optical fiber from forming a loop without using a special element such as a rotation mechanism in an optical fiber cable for connecting a light source to a treatment device.SOLUTION: One end of an optical fiber 120 is attached to an optical connector 110 and the other end is attached to a treatment device 300. The optical fiber 120 passes through a protective tube 130. One end of the protective tube 130 is fixed to the optical connector 110, and a fitting member 140 to be fitted to a fixing member on a side of the treatment device 300 is attached to the other end. The fixing member 310 is attached to an input-side end of the treatment device 300. A thin part 310b of the fixing member 310 is inserted to the fitting member 140, but the fixing member 310 and the fitting member 140 are not mutually fixed. When the treatment device 300 is axially rotated by an operation of a user, the optical fiber 120 is accordingly rotated, so as to be twisted inside the protective tube 130.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to optical fiber cables. [Background technology]

[0002] There are many medical devices that use optical fibers.

[0003] For example, there is a system that improves the visibility of a treatment device in an echo-guided catheter surgery by using the photoacoustic effect (see Patent Document 1). In this system, the treatment device to be introduced into the body is connected to a laser light source by an optical fiber, photoacoustic waves are generated from the treatment device by the photoacoustic effect, and the ultrasonic waves are detected by an ultrasound probe, thereby visualizing the position of the treatment device.

[0004] Patent Document 2 discloses a connector for connecting an optical fiber that guides laser light to the tip of a puncture needle for photoacoustic effects or the like to a light source unit.

[0005] In catheter surgery, it is common to rotate or move the treatment device around the axis of travel. The optical fiber for connection must be able to follow these operations. In particular, such operations are frequently used with guidewires, which are a type of treatment device. The action of rotating the guidewire around its axis twists the optical fiber, forming a loop in the middle. If the treatment device is pulled with a loop formed in the middle of the optical fiber, the loop will become smaller, and in the worst case scenario, the optical fiber may break.

[0006] Techniques for suppressing twisting of optical fibers are disclosed in Patent Documents 3 and 4. In Patent Documents 3 and 4, an optical connector cable connected to a light source and a guide wire are mechanically connected by a rotatable structure such as a bearing. Then, the optical fiber in the optical connector cable and the optical fiber in the guide wire are optically connected via a coupler.

[0007] Furthermore, Patent Documents 5 to 9 disclose mechanisms for rotating and protecting optical fibers connecting a device such as a probe to a main body device. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2019-213680 A [Patent Document 2] Patent No. 6873164 [Patent Document 3] Patent No. 6492061 [Patent Document 4] Patent No. 6669898 [Patent Document 5] JP 2007-135947 A [Patent Document 6] JP 2004-065320 A [Patent Document 7] JP 2013-195284 A [Patent Document 8] JP 2016-200647 A [Patent Document 9] Special Publication No. 2016-507271 Summary of the Invention [Problem to be solved by the invention]

[0009] An object of the present invention is to prevent the formation of a loop in an optical fiber cable connecting a light source and a treatment device, without using a special element such as a rotation mechanism. [Means for solving the problem]

[0010] The optical fiber cable disclosed in this specification is an optical fiber cable that connects a light source and a treatment device, and includes a connector connected to the light source, an optical fiber having one end fixed to the connector and the other end fixed to the treatment device, and a protective tube that has a bending rigidity greater than the bending rigidity of the optical fiber and covers the optical fiber from the connector to the treatment device, the protective tube being fixed to the connector but not fixed to the treatment device, and is characterized in that the protective tube and the optical fiber are not fixed to each other.

[0011] According to the optical fiber cable, the optical fiber can be twisted in the protective tube in response to the rotation of the treatment device around its axis. This twisting of the optical fiber allows the treatment device to rotate without using a rotation mechanism such as a bearing.

[0012] Here, the optical fiber may be longer than the protective tube and may be disposed in a bent state within the protective tube.

[0013] This structure allows the optical fiber to twist in response to rotation of the treatment device about its axis, forming a gentle spiral within the protective tube.

[0014] Furthermore, the end of the protective tube on the treatment device side may be fitted to a fixing member fixed to the treatment device so as to be rotatable about an axis.

[0015] In this configuration, the displacement of the protective tube in a direction perpendicular to the extending direction of the protective tube is restricted by the fixing member on the treatment device side to which the protective tube is fitted.

[0016] Furthermore, a fitting member that fits into the fixing member so as not to come off from the fixing member may be provided on the end of the protective tube on the treatment device side.

[0017] The inner diameter of the protective tube may be 1.2 times or more the outer diameter of the optical fiber.

[0018] In this configuration, the optical fiber can form a spiral inside the protective tube in response to rotation of the treatment device around its axis, thereby increasing the number of allowable rotations of the treatment device.

[0019] Also, a structure may be employed in which a portion of the optical fiber cable is fixed in a state in which a loop having a radius equal to or larger than the allowable bending radius of the optical fiber is formed.

[0020] This configuration can reduce the deterioration of the ease of handling of the optical fiber when the optical fiber cable is made long in order to increase the allowable number of rotations around the axis of the treatment device. Effect of the Invention

[0021] According to the present invention, in an optical fiber cable connecting a light source and a treatment device, it is possible to prevent the optical fiber from forming a loop without using a special element such as a rotation mechanism. [Brief description of the drawings]

[0022] [Figure 1] 1 is a diagram illustrating a configuration of an embodiment of an optical fiber cable. [Diagram 2] FIG. 2 is a schematic diagram showing an optical fiber twisted in a spiral shape inside a protective tube. [Diagram 3] 1 is a schematic diagram showing an optical fiber cable wound in a loop and fixed in place; [Figure 4] FIG. 1 is a diagram illustrating a configuration of a modified example of an optical fiber cable. [Diagram 5] 10A and 10B are diagrams illustrating the configuration of another embodiment of an optical fiber cable. [Figure 6] FIG. 1 is a diagram illustrating a configuration of a modified example of an optical fiber cable. [Figure 7]11A and 11B are diagrams illustrating the configuration of another modified example of the optical fiber cable. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Hereinafter, modes for carrying out the present invention (hereinafter, referred to as embodiments) will be described with reference to the drawings.

[0024] The optical fiber cable 100 illustrated in FIG. 1 includes an optical connector 110, an optical fiber 120, a protective tube 130, and a fitting member 140. FIG. 1 and FIGS. 2 to 7, which will be described later, are schematic diagrams for explaining the features of each embodiment and each modified example, and the dimensions of each member, such as the length, width, and diameter, are different from the actual ones. For example, the optical fiber cable 100 is actually much longer than the size of the optical connector 110, but is drawn much shorter than the actual size in order to fit it within the limited size of the drawing. In addition, in the drawing, members other than the laser light source unit 200 and the optical connector 110 are expressed in schematic cross-sectional views. The schematic cross-sectional views of each of these members do not necessarily accurately represent the actual cross-sections of the members, and portions that are not necessary for the explanation of this embodiment are largely omitted. For example, the treatment device 300 specifically has a structure like a guide wire with an optical fiber built in, but such a specific structure is not directly related to the features of the embodiment of the optical fiber cable 100. Therefore, in FIG. 1, the treatment device 300 is shown as a simple rod-shaped member.

[0025] The optical connector 110 is a member for detachably connecting the optical fiber 120 to the laser light source unit 200 .

[0026] One end of the optical fiber 120 is attached to the optical connector 110, and the other end is attached to the treatment device 300. The optical fiber 120 is fixedly attached to the treatment device 300 by adhesive or the like. Therefore, when the treatment device 300 is rotated around an axis along the extension direction of the optical fiber 120 (rightward in FIG. 1) by the user's operation, the optical fiber 120 also rotates by the same amount in response to the rotation. This rotation causes the optical fiber 120 to twist. When the optical connector 110 is connected to the laser light source unit 200, the laser light output by the laser light source unit 200 is guided to the treatment device 300 through the optical fiber 120.

[0027] The protective tube 130 is a tubular member for protecting the optical fiber 120. The length of the protective tube 130 is slightly shorter than the length of the optical fiber 120. The optical fiber 120 is accommodated in the protective tube 130 over almost the entire length. The shape of the tube of the protective tube 130 is, for example, cylindrical, and the inner diameter is larger than the outer diameter of the optical fiber 120 in the protective tube 130. Therefore, there is a gap between the outer peripheral surface of the optical fiber 120 in the protective tube 130 and the inner peripheral surface of the protective tube 130. In addition, the optical fiber 120 and the protective tube 130 are not fixed to each other. Since the optical fiber 120 is longer than the protective tube 130, the optical fiber 120 can be in a state of being slightly bent or twisted in the protective tube 130.

[0028] One end of the protective tube 130 is fixed to the optical connector 110 with an adhesive or the like. A fitting member 140 that fits with a fixing member 310 on the treatment device 300 side is attached to the other end of the protective tube 130. In the illustrated example, the fitting member 140 is a cylindrical member having an inner diameter approximately equal to the outer diameter of the protective tube 130. The fitting member 140 may be fixedly attached to the protective tube 130 with an adhesive or the like.

[0029] The protective tube 130 has a certain degree of flexibility that allows it to be bent, but its material, shape, and dimensions (e.g., tube thickness) are selected so that its bending rigidity is greater than that of the optical fiber 120 passing therethrough. In this way, since the bending rigidity of the protective tube 130 is greater than that of the optical fiber 120, it is difficult for a loop to form in the optical fiber 120 in response to the movement of the treatment device 300.

[0030] The protective tube 130 may be made of a material with a low coefficient of friction, such as Teflon (registered trademark), polyester resin, etc. This reduces friction between the optical fiber 120 and the protective tube 130, and between the protective tubes 130 themselves (for example, between one portion of one protective tube 130 and another portion), making it easier to handle the optical fiber cable 100.

[0031] Although the protective tube 130 has a thickness, for the sake of simplicity, it is represented by a single thick line in the drawing.

[0032] The treatment device 300 is an example of a device that uses laser light supplied via the optical fiber 120, and serves to treat a patient. The treatment device 300 may be a device that treats an affected area with laser light, or may be a device that serves to assist treatment by illuminating the inside of a body cavity with laser light, generating ultrasound waves by the photoacoustic effect, or the like.

[0033] This is merely an example. The treatment device 300 may be a guidewire used in catheter surgery or the like. An example of such a guidewire is a guidewire equipped with a generating member that generates a photoacoustic signal at its tip (i.e., the left end of the treatment device 300 in the figure). This type of guidewire incorporates a light-guiding member such as an optical fiber that guides light from its input end (i.e., the right end of the treatment device 300 in the figure) to its tip. The input end of this member is fixedly connected (for example, bonded) to the optical fiber 120 in the optical fiber cable 100 in a manner that allows laser light to be transmitted. Alternatively, the optical fiber 120 itself may extend through the guidewire to the photoacoustic generating member provided at the tip of the guidewire. In this example, pulses of laser light emitted from the laser light source unit 200 are irradiated to the photoacoustic generating member at the tip of the guidewire through the optical fiber 120 in the optical fiber cable 100 and the light-guiding member in the guidewire. This irradiation of pulsed laser light causes the photoacoustic generating member to suddenly expand and contract, generating ultrasonic waves. An ultrasound probe (not shown) detects the ultrasound waves and forms an image of the affected area.

[0034] A fixing member 310 is fixedly attached to the input end (i.e., the right end in the figure) of the treatment device 300 by adhesive or the like. The fixing member 310 connects the protective tube 130 and the treatment device 300 by fitting with the fitting member 140 of the optical fiber cable 100. The fixing member 310 may be used to fix the optical fiber 120 to the treatment device 300 side. For example, the optical fiber 120 can be fixed to the treatment device 300 via the fixing member 310 by adhering the side of the end (i.e., the left end in the figure) of the optical fiber 120 to the inner surface of the fixing member 310.

[0035] The optical fiber 120 extends from the optical connector 110 through the protective tube 130 and the fixing member 310 to the treatment device 300 .

[0036] In the illustrated example, which is merely an example, the fixing member 310 is a cylinder with an inner diameter approximately equal to the outer diameter of the treatment device 300, and is composed of a thick-walled portion 310a and a thin-walled portion 310b. The outer diameter of the thin-walled portion 310b is equal to or smaller than the inner diameter of the fitting member 140. The fixing member 310 and the fitting member 140 are fitted together by inserting this thin-walled portion 310b into the fitting member 140 at the end of the protective tube 130. In addition, since the outer diameter of the thick-walled portion 310a is larger than the inner diameter of the fitting member 140, only the thin-walled portion 310b of the fixing member 310 can enter the fitting member 140.

[0037] The lengths of the optical fiber 120, the protective tube 130, the engaging member 140, and the thin-walled portion 310b are determined so that the thin-walled portion 310b does not come out from within the engaging member 140 when the treatment device 300 is pulled and the optical fiber 120 becomes straight without bending.

[0038] Typically, there is a gap between the outer surface of the thin-walled portion 310b and the inner surface of the fitting member 140. Therefore, the fixing member 310 and the treatment device 300 fixedly connected thereto are rotatable with respect to the fitting member 140 and the protective tube 130 fixedly connected thereto. Processing or design for reducing friction between the outer surface of the thin-walled portion 310b and the inner surface of the fitting member 140 may be adopted. For example, a lubricant may be applied between both surfaces, or both surfaces or at least one of the surfaces may be subjected to a low-friction processing such as Teflon processing. In addition, for example, a member for reducing friction such as a Teflon bushing may be attached to the thin-walled portion 310b to reduce friction between the thin-walled portion 310b side and the fitting member 140. Such a member for reducing friction may be provided on the inner surface of the fitting member 140, or may be provided on both the outer surface of the thin-walled portion 310b and the inner surface of the fitting member 140. In addition, the thin-walled portion 310b and the fitting member 140 may be made of a material with a low friction coefficient.

[0039] As another example, the outer surface of the thin portion 310b and the inner surface of the fitting member 140 may be fitted in contact with each other, but even in this case, the fixing member 310 is made rotatable relative to the fitting member 140 so as not to interfere with the operation of the treatment device 300. This can be achieved by selecting materials for the fixing member 310 and the fitting member 140 so that the friction between these two surfaces is somewhat low, or by adopting processing or design for reducing friction between these two surfaces (for example, the use of lubricants or low-friction materials).

[0040] The connection structure between the optical fiber cable 100 and the treatment device 300 has been described above. In this structure, the optical fiber 120 is somewhat longer than the protective tube 130. Therefore, when the fitting member 140 of the optical fiber cable 100 and the fixing member 310 on the treatment device 300 side are fitted together, the optical fiber 120 is arranged in a state of being bent to some extent in the protective tube 130. In addition, when the treatment device 300 rotates around its axis, the optical fiber 120 bent in the protective tube 130 twists in the protective tube 130 in response to the rotation, and forms a gentle spiral in the protective tube 130 when the twisting becomes strong.

[0041] Here, since the optical fiber 120 is fixedly attached to the treatment device 300, when the treatment device 300 is rotated around an axis in the longitudinal direction (i.e., in the figure, the direction from the end of the treatment device 300 connected to the optical fiber 120 to the opposite end) by the user's operation, the fixed end rotates the same amount. This rotation causes a twisting force around the axis to act on the optical fiber 120. On the other hand, since the protective tube 130 is not fixed to the treatment device 300, even if the treatment device 300 rotates around the axis, the protective tube 130 does not follow the rotation.

[0042] When the treatment device 300 rotates around its axis, as illustrated in FIG. 2, the optical fiber 120 receives a torsional force in the direction of the arrow a due to the rotation of the treatment device 300 and is twisted in the protective tube 130. On the other hand, the protective tube 130 and the fitting member 140 at its end are not in contact with the fixing member 310 on the treatment device 300 side, or even if they are in contact, the friction with the inner surface of the fixing member 310 is sufficiently small. Therefore, even if the treatment device 300 rotates around its axis, the protective tube 130 is not affected at all or is hardly affected by the rotation, and is not twisted at all or almost at all. In other words, when the treatment device 300 is rotated around its axis, the protective tube 130 does not provide any or almost no resistance, and the only thing that provides resistance is the optical fiber 120. If the optical fiber 120 is sufficiently long (for example, 2 m or more), the torsional springiness of the optical fiber 120, which is a resistance when the treatment device 300 is rotated around its axis, can be sufficiently small, and there is almost no adverse effect on the operability of the treatment device 300.

[0043] When the twist becomes large to a certain extent, the optical fiber 120 forms a loose spiral in the protective tube 130. Due to the formation of the spiral, the optical fiber 120 receives a force in the direction of the arrow A in the figure, and the length of the optical fiber 120 along the extension direction of the optical fiber cable 100 becomes shorter. In this case, too, by making the optical fiber 120 somewhat longer than the protective tube 130, it is possible to prevent the fixing member 310 on the treatment device 300 side from being strongly pressed against the fitting member 140 on the protective tube 130 side even if the optical fiber 120 becomes shorter. If the fixing member 310 is strongly pressed against the fitting member 140, the friction between them increases the resistance to the operation of rotating the treatment device 300 around its axis.

[0044] 2 is an exaggerated view for the purpose of explanation, and the dimensions are not the same as the actual ones. For example, the relationship between the diameter φ1 of the optical fiber 120 and the inner diameter φ2 and outer diameter φ3 of the protective tube 130 shown in the figure does not necessarily match the actual one. Also, in FIG. 2, the pitch of the spiral formed by twisting the optical fiber 120 is exaggerated and drawn shorter than the actual one.

[0045] When the treatment device 300 is a guidewire for catheter surgery, the outer diameter of the guidewire is about 0.5 mm (for example, about 0.3 to 1 mm), and the diameter of the optical fiber that passes through it and guides light to the photoacoustic generating member at the tip of the guidewire is, for example, about 0.2 mm. The diameter of the optical fiber 120 that guides laser light to the guidewire is also, for example, about 0.2 mm. In this case, the length of the optical fiber cable 100 (i.e., the optical fiber 120 and the protective tube 130) is preferably 2 m or more, and more preferably about 3 m. When using the optical fiber 120 with a diameter of about 0.2 mm, a length of 2 m or more can sufficiently reduce the torsional springiness that resists the operation of rotating the treatment device 300 around its axis.

[0046] The inner diameter φ2 of the protective tube 130 is determined so that there is a sufficient gap between the optical fiber 120 and the inner surface of the protective tube 130. The sufficient gap here means a gap large enough to allow the optical fiber 120 inserted into the protective tube 130 to rotate freely. To satisfy this condition, it is desirable that the inner diameter φ2 of the protective tube 130 is 1.2 times or more the diameter φ1 of the optical fiber 120. If a protective tube 130 with such an inner diameter φ2 is used, the optical fiber 120 can be twisted helically within the protective tube 130.

[0047] Thus, in this embodiment, the protective tube 130 and the optical fiber 120 have a dimensional relationship that allows the optical fiber 120 to twist in a spiral shape within the protective tube 130. This allows the treatment device 300 to rotate more around its axis than if the optical fiber 120 had a dimensional relationship that did not allow the optical fiber 120 to form a spiral within the protective tube 130. This increases the degree of freedom of operation of the treatment device 300.

[0048] For example, let us assume that the diameter φ1 of the optical fiber 120 is about 0.2 mm, the inner diameter φ2 of the protective tube 130 is about 0.4 mm, the total length of the optical fiber 120 and the protective tube 130 is about 3 m, and the optical fiber 120 forms a spiral twisted about 100 times within that total length. In this case, the radius of curvature of the spiral is about 20 cm. This radius of curvature is sufficiently larger than the allowable bending radius of 30 mm for the optical fiber 120 specified by the standard.

[0049] Moreover, the inner diameter φ2 of the protective tube is set smaller than the diameter of the thick portion 310a of the fixing member 310 so that the fixing member 310 does not enter the protective tube .

[0050] In addition, the material, inner diameter, and outer diameter of the protective tube 130 are determined so that the bending rigidity of the protective tube 130 is greater than that of the optical fiber 120 so that the protective tube 130 does not form a loop together with the optical fiber 120 when the optical fiber 120 is twisted strongly. However, if the bending rigidity of the protective tube 130 is too large, it may hinder the operation of the treatment device 300, or the difference with the behavior of the optical fiber 120 with respect to bending or the like may become too large, which may lead to damage of the optical fiber 120. In order to avoid such a situation, it is necessary to prevent the bending rigidity of the protective tube 130 from becoming too large. In addition, in order to regulate the deformation of the optical fiber 120, it is preferable that the protective tube 130 has a smaller diameter. From the viewpoint of these conditions and manufacturing, it is preferable that the inner diameter φ2 of the optical fiber 120 is, for example, about 1.2 to 4 times the diameter φ1 of the optical fiber 120, and the outer diameter φ3 is, for example, about 1.5 to 3 times the inner diameter φ2.

[0051] If the optical fiber cable 100 is long (e.g., 2 m or longer), it may become difficult to handle, for example, because it may get caught on other cables or other objects. To alleviate such problems, the optical fiber cable 100 may be wound into a loop having a radius equal to or greater than the allowable bending radius of the optical fiber 120 (e.g., 30 mm or 60 mm), as exemplified in Fig. 3, and the loop may be fixed by bonding or bundling with a cable tie or the like. Since this loop is fixed, even if the treatment device 300 is pulled, the radius of the loop does not become smaller, and there is little risk of the characteristics of the optical fiber 120 deteriorating or the optical fiber 120 breaking.

[0052] 1, the engaging member 140 and the fixing member 310 may have a structure for preventing the engaging member 140 from coming off from the fixing member 310. For example, a flange may be formed at the end of the thin-walled portion 310b of the fixing member 310 on the protective tube 130 side, and the end of the engaging member 140 on the treatment device 300 side may be tapered to have an opening smaller than the diameter of the flange.

[0053] Fig. 4 shows a modified example of the embodiment shown in Fig. 1. In Fig. 4, the same components as those shown in Fig. 1 are given the same reference numerals as in Fig. 1, and duplicated explanations will be omitted.

[0054] 1, the fitting member 140 is removed, and a structure is adopted in which the thin-walled portion 310b of the fixing member 310 is directly inserted into the protective tube 130. In this structure, the outer diameter of the thin-walled portion 310b is equal to or smaller than the inner diameter of the protective tube 130, and the outer diameter of the thick-walled portion 310a is larger than the inner diameter of the protective tube 130.

[0055] Next, another embodiment will be described with reference to Fig. 5. In Fig. 5, components similar to those shown in Fig. 1 are given the same reference numerals as in Fig. 1, and duplicated descriptions will be omitted.

[0056] 1, the thin-walled portion 310b of the fixing member 310 on the treatment device 300 side is structured to fit into the fitting member 140 at the end of the protective tube 130. In contrast, the embodiment of FIG. 5 employs a structure in which the fitting member 150 at the end of the protective tube 130 fits into the fixing member 320 on the treatment device 300 side.

[0057] 5, one end of the optical fiber 120 is fixed to the optical connector 110 by an adhesive 122, and the other end is fixed to the treatment device 300 by an adhesive 124. Moreover, one end of the protective tube 130 through which the optical fiber 120 is inserted is fixed to the optical connector 110 by an adhesive 152. Moreover, a fitting member 150 is fixedly attached to the other end of the protective tube 130 by an adhesive 154. The inner diameter of the fitting member 150 is larger than the diameter of the optical fiber 120, and is, for example, approximately the same as the inner diameter of the protective tube 130. The outer diameter of the fitting member 150 is larger than the outer diameter of the protective tube 130.

[0058] The fixing member 320 is a generally cylindrical member, and one end of the fixing member 320 is fixedly attached to the treatment device 300 by an adhesive 302. Inside the fixing member 320, a storage chamber 320a is formed to store the fitting member 150. The storage chamber 320a is a cylindrical space, and its inner diameter is larger than the outer diameter of the fitting member 150. The other end of the fixing member 320, that is, the end on the protective tube 130 side, is structured to form an opening 320b with a diameter smaller than the outer diameter of the fitting member 150. Therefore, the fitting member 150 does not come off from the storage chamber 320a to the optical connector 110 side. That is, this structure prevents the treatment device 300 from coming off the protective tube 130.

[0059] The length of the storage chamber 320a in the direction in which the treatment device 300 extends (horizontal direction in the figure) is longer than the length of the fitting member 150 in the same direction. Therefore, the treatment device 300 can move back and forth to some extent relative to the protective tube 130 while maintaining the state in which the fitting member 150 is fitted to the fixing member 320. This difference in length also helps to absorb the effect of shortening of the optical fiber 120 when the optical fiber 120 is twisted to form a spiral due to the rotation of the treatment device 300 around its axis.

[0060] Other than the shapes and structures of the fixing member 320 and the fitting member 150 in this embodiment, the parts may be similar to those in the embodiment shown in FIG.

[0061] 5, the optical fiber 120 is attached to the optical connector 110 and the treatment device 300 by adhesives 122 and 124, but this is merely an example. Any attachment method may be used as long as the two are fixed. Similarly, the optical connector 110 and the fitting member 150 may be attached to the protective tube 130, and the fixing member 320 may be attached to the treatment device 300 by a fixing method other than adhesives.

[0062] A modified example of the embodiment shown in Fig. 5 is shown in Fig. 6. In Fig. 6, the same components as those shown in Fig. 1 and Fig. 5 are given the same reference numerals as in Fig. 1, and duplicated explanations will be omitted.

[0063] In the modified example of FIG. 6, the fitting member 150 in the embodiment of FIG. 5 is replaced with a bearing 160. The outer diameter of the bearing 160 is approximately the same as the inner diameter of the accommodation chamber 320a of the fixing member 320, and the two fit together with almost no gap. The outer peripheral surface of the bearing 160 may or may not be fixed to the cylindrical inner peripheral surface of the accommodation chamber 320a. If it is not fixed, the materials of the outer peripheral surface of the bearing 160 and the inner peripheral surface of the accommodation chamber 320a may be selected so that the outer peripheral surface of the bearing 160 can slide axially against the inner peripheral surface of the accommodation chamber 320a, or processing or design may be adopted to reduce friction between these two surfaces.

[0064] The protective tube 130 is fixedly attached to the inner ring of the bearing 160 by adhesive or the like.

[0065] In this modification, the bearing 160 allows the treatment device 300 to rotate smoothly around its axis. In addition, the bearing 160 fits into the inner peripheral surface of the storage chamber 320a with almost no gap, so the protective tube 130 does not rattle in the radial direction of the bearing 160 relative to the fixing member 320, and the treatment device 300 is easy to handle.

[0066] Another modified example is shown in Fig. 7. In Fig. 7, the same components as those shown in Fig. 1 and Fig. 5 are given the same reference numerals as in Fig. 1, and duplicated explanations will be omitted.

[0067] This modified example removes the fitting member 150 from the embodiment illustrated in FIG. 5, and adopts a structure in which the protective tube 130 is directly inserted into the opening 330b of the fixing member 330. The inner diameter of the opening 330b is equal to or larger than the outer diameter of the protective tube 130. There may be a gap between the outer peripheral surface of the protective tube 130 and the inner peripheral surface of the opening 330b. Also, the outer peripheral surface of the protective tube 130 may fit into the inner peripheral surface of the opening 330b with almost no gap. However, even in this case, the material of the protective tube 130 and the fixing member 330 is selected, or processing or design for low friction is performed so that the friction between the outer peripheral surface of the protective tube 130 and the inner surface of the opening 330b is sufficiently small so as not to interfere with the operation of rotating the treatment device 300 around its axis.

[0068] In this structure, the fixing member 330 is fixed in position by being inserted into the end of the protective tube 130 , and is pulled toward the laser light source unit 200 by the optical fiber 120 , so that it does not separate from the protective tube 130 .

[0069] In each of the embodiments and modifications described above, the optical fiber 120 is not limited to a single fiber, but may be a combination of a plurality of optical fibers.

[0070] In the above, a guidewire utilizing the photoacoustic effect has been given as the main example of a treatment device 300, but the optical fiber cable 100 of each of the above embodiments and modifications can also be applied to other types of treatment devices 300 that utilize light supplied via an optical fiber 120. The optical fiber cable 100 can also be applied to a treatment device 300 including an optical detachable part or an extension cable. In this case, the end of the optical fiber 120 in the optical fiber cable 100 is fixedly connected to the end of the optical detachable part or extension cable included in the treatment device 300. The end of the protective tube 130 is not fixed to the end of the optical detachable part or extension cable. The main body of the treatment device 300 is detachable from the detachable part or extension cable. In this example, since the detachable part or extension cable is a part of the treatment device 300, it can be said that the optical fiber 120 is fixed to the treatment device 300. In this example, the optical detachable part may be a configuration shown in Patent Documents 3 and 4, for example, in which two optical fibers can be detachably connected via a coupler. Note that in the devices disclosed in Patent Documents 3 and 4, the detachable part having a coupler has a rotatable structure such as a bearing, and this structure allows rotation around the axis of the guide wire. In contrast, in this embodiment, even if the detachable part does not have such a rotatable structure, the influence of rotation about the axis of the treatment device 300 can be absorbed by the twisting of the optical fiber 120.

[0071] The embodiment and modifications of the present invention have been described above. These embodiments and modifications are merely examples for the purpose of explanation. Various modifications and improvements are possible within the scope of the present invention. [Explanation of symbols]

[0072] 100 optical fiber cable, 110 optical connector, 120 optical fiber, 130 protective tube, 140, 150 fitting member, 200 laser light source unit, 300 treatment device, 310 fixing member.

Claims

1. A fiber optic cable connecting a light source and a treatment device, A connector connected to the light source; an optical fiber having one end fixed to the connector and the other end fixed to the treatment device; a protective tube having a bending stiffness greater than the bending stiffness of the optical fiber, covering the optical fiber from the connector to the treatment device, the protective tube being fixed to the connector but not fixed to the treatment device; wherein the protective tube and the optical fiber are not fixed to each other.

2. 2. The optical fiber cable according to claim 1, wherein the optical fiber is longer than the protective tube and is arranged in a bent state within the protective tube.

3. The end of the protective tube on the treatment device side is fitted to a fixing member fixed to the treatment device so as to be rotatable around an axis.

2. The optical fiber cable according to claim 1 .

4. 4. The optical fiber cable according to claim 3, wherein the end of the protective tube on the treatment device side is provided with a fitting member that fits with the fixing member so as not to come off from the fixing member.

5. 2. The optical fiber cable according to claim 1, wherein the inner diameter of the protective tube is 1.2 times or more the outer diameter of the optical fiber.

6. 2. The optical fiber cable according to claim 1, wherein a portion of the optical fiber cable is fixed in a state in which a loop having a radius equal to or larger than an allowable bending radius of the optical fiber is formed.

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