Catheter for image diagnosis

Abstract

The present invention provides a catheter for image diagnosis that makes it possible to visually confirm the position of a tip end, and that can suppress the occurrence of defects in a captured image. A catheter (100) for image diagnosis comprises: a sensor lumen (110a) in which is inserted a light guide (143) that is connected, at the tip end thereof, to a light transmission / reception unit (145b) for transmitting and receiving light; and a guide wire lumen (170a) in which a guide wire (W) is inserted. A guide wire insertion member (170) which constitutes the guide wire lumen has a first region (171) that is provided together with the sensor lumen in at least part of an imaging region of the light transmission / reception unit, and a second region (172) that is provided to the tip end side of the first region and that is not provided together with the sensor lumen. A colored part is formed at at least the tip-most end of the second region. The first region is lighter in color than the colored part of the second region.

Description

Diagnostic imaging catheters

[0001] The present invention relates to a catheter for diagnostic imaging.

[0002] BACKGROUND ART Conventionally, as a medical device used to acquire tomographic images for diagnosing diseased sites and the like in a living body, there is a diagnostic imaging catheter used in an imaging diagnostic device such as an intravascular ultrasound (IVUS) or an optical coherence tomography (OCT).

[0003] The diagnostic imaging catheter includes a drive shaft provided with a signal transmitting / receiving unit that transmits and receives examination waves, and a sheath with a lumen into which the drive shaft is inserted so as to be movable back and forth. When the diagnostic imaging catheter is in use, the drive shaft is rotated and moved backward to move the drive shaft from the distal end to the proximal end, a so-called pull-back operation (intermediate pulling operation), or a pushing operation to push the drive shaft toward the distal end (see Patent Document 1 listed below).

[0004] Japanese Patent Application Laid-Open No. 2012-223206

[0005] The catheter of the above-mentioned Patent Document 1 discloses a configuration in which a sensor lumen into which a light guide (imaging core) is inserted and a guide wire lumen into which a guide wire is inserted are formed along the axial direction (longitudinal direction).

[0006] The inventors discovered that in the catheter of Patent Document 1 mentioned above, when the guidewire insertion member that constitutes the guidewire lumen is colored to enable the operator to visually check the tip position of the catheter in order to improve usability, defects occur in the captured image due to the coloring.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a catheter for diagnostic imaging that allows the tip position to be visually confirmed and prevents defects from occurring in the captured image.

[0008] The above object of the present invention can be achieved by the following means.

[0009] (1) A catheter for diagnostic imaging having a sensor lumen into which a light guide body having a light transmitting and receiving unit connected to its tip for transmitting and receiving light is inserted, and a guide wire lumen into which a guide wire is inserted, wherein a guide wire insertion member constituting the guide wire lumen has: a first region that is adjacent to the sensor lumen in at least a part of an imaging area of ​​the light transmitting and receiving unit; and a second region that is provided at the tip of the first region and is not adjacent to the sensor lumen; a colored portion is formed at at least the tip of the second region; and the first region is lighter in color than the colored portion of the second region.

[0010] (2) The diagnostic imaging catheter according to (1), wherein the second region contains tungsten and titanium oxide.

[0011] (3) The diagnostic imaging catheter according to (1) or (2), wherein the first region is made of only a resin material.

[0012] (4) The diagnostic imaging catheter according to any one of (1) to (3), wherein a colored portion is formed over the entire second region.

[0013] (5) The diagnostic imaging catheter according to any one of (1) to (4), wherein the first region and the second region are provided spaced apart from each other.

[0014] (6) The diagnostic imaging catheter according to any one of (1) to (4), wherein the first region and the second region are provided in communication with each other.

[0015] In the diagnostic imaging catheter configured as described above, a colored portion is formed at least at the tip of the second region of the guidewire insertion member, making it possible to visually confirm the tip position of the diagnostic imaging catheter. Furthermore, since the first region of the guidewire insertion member is lighter in color than the colored portion of the second region, it is possible to prevent defects from occurring in the captured image.

[0016] FIG. 1 is a plan view showing a state in which an external device is connected to a catheter for diagnostic imaging according to an embodiment of the present invention. FIG. 2 is a view schematically showing the overall configuration of a catheter for diagnostic imaging according to this embodiment, and is a side view of the catheter for diagnostic imaging before a pull-back operation (intermediate pulling operation) is performed. FIG. 3 is a view schematically showing the overall configuration of a catheter for diagnostic imaging according to this embodiment, and is a side view of the catheter for diagnostic imaging when a pull-back operation is performed. FIG. 4 is an enlarged sectional view showing the configuration of the tip side of the catheter for diagnostic imaging according to this embodiment. FIG. 5 is an enlarged front view showing the configuration of the tip side of the catheter for diagnostic imaging according to this embodiment. FIG. 6 is an enlarged sectional view showing the configuration of the base end side of the catheter for diagnostic imaging according to this embodiment. FIG. 7 is a view corresponding to FIG. 4 of a catheter for diagnostic imaging according to Modification 1.

[0017] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Note that the following description does not limit the technical scope or meaning of terms described in the claims. Also, the dimensional proportions in the drawings are exaggerated for the convenience of explanation and may differ from the actual proportions.

[0018] FIG. 1 is a plan view showing a state in which an external device 300 is connected to a diagnostic imaging catheter 100 according to an embodiment. FIG. 2A is a diagram schematically showing the overall configuration of the diagnostic imaging catheter 100 according to an embodiment, and is a side view of the diagnostic imaging catheter 100 before a pull-back operation (intermediate pulling operation) is performed. FIG. 2B is a diagram schematically showing the overall configuration of the diagnostic imaging catheter 100 according to an embodiment, and is a side view of the diagnostic imaging catheter 100 after a pull-back operation is performed. FIG. 3 is an enlarged cross-sectional view showing the configuration of the distal end side of the diagnostic imaging catheter 100 according to this embodiment. FIG. 4 is an enlarged front view showing the configuration of the distal end side of the diagnostic imaging catheter 100 according to this embodiment. FIG. 5 is an enlarged cross-sectional view showing the configuration of the proximal end side of the diagnostic imaging catheter 100 according to this embodiment.

[0019] The diagnostic imaging catheter 100 according to this embodiment is a dual-type catheter that has both intravascular ultrasound (IVUS) and optical coherence tomography (OCT) functions and can be used either by switching between them or simultaneously. As shown in Fig. 1, the diagnostic imaging catheter 100 is driven by being connected to an external device 300.

[0020] The configuration of the diagnostic imaging catheter 100 will be described with reference to FIGS.

[0021] 1, 2A, and 2B, the diagnostic imaging catheter 100 includes a sheath 110 to be inserted into a body cavity of a living body, an outer tube 120 provided on the proximal end side of the sheath 110, an inner shaft 130 inserted into the outer tube 120 so as to be movable back and forth, a drive shaft 140 provided on the distal end thereof with a signal transmitting / receiving unit 145 for transmitting and receiving signals and rotatably provided within the sheath 110, a unit connector 150 provided on the proximal end side of the outer tube 120 and configured to receive the inner shaft 130, a hub 160 provided on the proximal end side of the inner shaft 130, and a guidewire insertion member 170 attached to the distal end of the sheath 110 and through which a guidewire W is inserted.

[0022] In the description of this specification, the side of the diagnostic imaging catheter 100 that is inserted into a body cavity is referred to as the tip or tip side, the side of the hub 160 provided on the diagnostic imaging catheter 100 is referred to as the base end or base side, and the extension direction of the sheath 110 is referred to as the axial direction.

[0023] As shown in FIG. 2A , the drive shaft 140 passes through the sheath 110 , the outer tube 120 connected to the proximal end of the sheath 110 , and the inner shaft 130 inserted into the outer tube 120 , and extends to the inside of the hub 160 .

[0024] The hub 160, inner shaft 130, drive shaft 140, and signal transmitter / receiver 145 are connected to one another so as to move forward and backward in the axial direction as a unit. Therefore, for example, when the hub 160 is pushed toward the distal end, the inner shaft 130 connected to the hub 160 is pushed into the outer tube 120 and the unit connector 150, and the drive shaft 140 and the signal transmitter / receiver 145 move toward the distal end inside the sheath 110. For example, when the hub 160 is pulled toward the proximal end, the inner shaft 130 is pulled out from the outer tube 120 and the unit connector 150 as shown by arrow a1 in Figures 1 and 2B, and the drive shaft 140 and the signal transmitter / receiver 145 move toward the proximal end inside the sheath 110 as shown by arrow a2.

[0025] 2A , when the inner shaft 130 is pushed all the way toward the distal end, the distal end of the inner shaft 130 reaches the vicinity of the relay connector 180. At this time, the signal transmitting / receiving unit 145 is located near the distal end of the sheath 110. The relay connector 180 is a connector that connects the sheath 110 and the outer tube 120.

[0026] 2B , a connector 131 for preventing disengagement is provided at the tip of the inner shaft 130. The connector 131 for preventing disengagement has the function of preventing the inner shaft 130 from disengaging from the outer tube 120. The connector 131 for preventing disengagement is configured to catch at a predetermined position on the inner wall of the unit connector 150 when the hub 160 is pulled all the way toward the base end, that is, when the inner shaft 130 is pulled all the way out from the outer tube 120 and the unit connector 150.

[0027] 3, the drive shaft 140 includes a flexible coil shaft 141, inside which are arranged an electric signal cable 142 connected to a signal transmitter / receiver 145, and a light guide (optical fiber) 143. The coil shaft 141 can be formed, for example, of a multi-layer coil wound in different directions around the axis. Examples of materials for the coil include stainless steel and Ni-Ti (nickel-titanium) alloy.

[0028] 3, the signal transmitting / receiving unit 145 has an ultrasonic transmitting / receiving unit 145a that transmits and receives ultrasonic waves, and an optical transmitting / receiving unit 145b that transmits and receives light. The ultrasonic transmitting / receiving unit 145a is located closer to the tip than the optical transmitting / receiving unit 145b. Note that the positional relationship between the ultrasonic transmitting / receiving unit 145a and the optical transmitting / receiving unit 145b may be reversed.

[0029] The ultrasonic transmitting / receiving unit 145a includes a vibrator and has the function of transmitting ultrasonic waves into the body cavity based on a pulse signal and receiving ultrasonic waves reflected from the living tissue of the body cavity. The ultrasonic transmitting / receiving unit 145a is electrically connected to the electrode terminal 165a (see FIG. 5) via the electric signal cable 142.

[0030] The transducer included in the ultrasonic wave transmitting / receiving unit 145a may be made of a piezoelectric material such as ceramics or quartz crystal.

[0031] The optical transmitter / receiver 145b continuously transmits the transmitted measurement light into the body cavity and continuously receives the reflected light from the biological tissue in the body cavity. The optical transmitter / receiver 145b is provided at the tip of the light guide 143 and has a ball lens (optical element) that has a lens function to condense light and a reflecting function to reflect light.

[0032] 3, the signal transmitting / receiving unit 145 is accommodated inside a housing 190. The base end side of the housing 190 is connected to the coil shaft 141. The housing 190 has a groove 191 on its outer circumferential surface that is provided so as not to impede the progression of the ultrasonic waves transmitted and received by the ultrasonic transmitting / receiving unit 145a and the light transmitted and received by the optical transmitting / receiving unit 145b.

[0033] 3, sheath 110 has sensor lumen 110a into which drive shaft 140 is inserted so as to be movable back and forth. A communication hole 116 is formed at the distal end of sheath 110, which connects the inside and outside of sensor lumen 110a.

[0034] 3, a reinforcing member 117 is provided at the distal end of sheath 110 to firmly join and support guidewire insertion member 170. Reinforcing member 117 has a communication passage 117a formed therein that connects the interior of sensor lumen 110a, which is located proximal to reinforcing member 117, with communication hole 116. Note that reinforcing member 117 does not necessarily have to be provided at the distal end of sheath 110.

[0035] The communication hole 116 is a priming solution discharge hole for discharging the priming solution. When the diagnostic imaging catheter 100 is used, a priming process is performed in which the sheath 110 is filled with priming solution to reduce attenuation of ultrasound due to air inside the sheath 110 and to efficiently transmit and receive ultrasound. When performing the priming process, the priming solution is released to the outside through the communication hole 116, and gas such as air can be discharged from the inside of the sheath 110 together with the priming solution.

[0036] 3, the guidewire insertion member 170 is attached to the distal end of the sheath 110. The guidewire insertion member 170 has a guidewire lumen 170a into which the guidewire W is inserted.

[0037] 3 , the guidewire insertion member 170 has a first region 171 provided adjacent to the sensor lumen 110a in the imaging region of the signal transmitting / receiving unit 145, and a second region 172 provided at the tip of the first region 171. In this embodiment, the first region 171 and the second region 172 are spaced apart along the axial direction. A spaced region 173 between the first region 171 and the second region 172 constitutes a window portion that is more transparent to inspection waves such as light and ultrasound than other regions.

[0038] The first region 171 is provided adjacent to the region of the sensor lumen 110a through which the signal transmitting / receiving unit 145 passes when an image is acquired by the diagnostic imaging catheter 100. The first region 171 is configured to be lighter in color than the second region 172. In this specification, "dark / light color" means that the closer a color is to transparency (the smaller the difference), the lighter it is, and the further away it is from transparency (the larger the difference), the darker it is.

[0039] In other words, the first region 171 is configured to have higher light transmittance than the second region 172. Here, for example, if the first region 171 is configured to have lower light transmittance (darker color) than the second region 172, it may be difficult for the light emitted by the optical transmitting / receiving unit 145b to reach the diseased site in the living body, and it may not be possible to properly acquire a tomographic image.

[0040] In contrast, according to the imaging diagnostic catheter 100 of this embodiment, the first region 171 is configured to have higher light transmittance (lighter color) than the second region 172, thereby preventing defects from occurring in the captured image.

[0041] First region 171 of guidewire insertion member 170 is preferably made only of a resin material, which will be described later, and preferably does not contain a pigment, such as that contained in second region 172, which will be described later. This configuration makes it possible to more reliably make first region 171 more light-transmitting than second region 172.

[0042] The second region 172 is provided on the distal side of the first region 171 and is configured not to be located next to the sensor lumen 110a. In other words, the second region 172 is located on the distal side of the forward limit position of the signal transmitting / receiving unit 145.

[0043] In this embodiment, the entire second region 172 is made up of a colored portion (see the black portion in FIG. 4 ) as shown in Fig. 4. The second region 172 of the guidewire insertion member 170 contains a pigment in addition to a resin material, which will be described later.

[0044] Examples of pigments that can be added include copper phthalocyanine, calcium stearate, zinc stearate, titanium oxide, carbon black, silica, and tungsten. Among these, adding titanium oxide can impart X-ray contrast to the second region 172, improving usability for the surgeon under X-ray imaging. Adding tungsten can make the second region 172 black, improving the visibility of the tip position of the diagnostic imaging catheter 100. Note that the pigment used to color the second region 172 is not limited to tungsten, and the color of the colored portion is not limited to black.

[0045] The sheath 110 and the guide wire insertion member 170 can be integrally formed by heat fusion or the like.

[0046] The sheath 110, guidewire insertion member 170, and reinforcing member 117 are formed of a flexible material, and the material may be, but is not limited to, various thermoplastic elastomers such as styrene-based, polyolefin-based, polyurethane-based, polyester-based, polyamide-based, polyimide-based, polybutadiene-based, trans-polyisoprene-based, fluororubber-based, and chlorinated polyethylene-based, and combinations of one or more of these (polymer alloys, polymer blends, laminates, etc.) may also be used. A hydrophilic lubricating coating layer that exhibits lubricity when wet may be disposed on the outer surface of the sheath 110.

[0047] As shown in FIG. 5 , the hub 160 has a hollow hub body 161, a connector case 161a connected to the base end side of the hub body 161, a port 162 that communicates with the interior of the hub body 161, protrusions 163a and 163b for positioning (orienting) the hub 160 when connecting to an external device 300, a connecting pipe 164b that holds the drive shaft 140, a bearing 164c that rotatably supports the connecting pipe 164b, a sealing member 164a that prevents the priming solution from leaking from between the connecting pipe 164b and the bearing 164c toward the base end side, and a connector portion 165 that has an electrode terminal 165a and an optical connector 165b disposed therein that are connected to the external device 300.

[0048] An inner shaft 130 is connected to the tip end of the hub body 161. The drive shaft 140 is drawn out from the inner shaft 130 inside the hub body 161. A protective tube 133 is disposed between the inner shaft 130 and the drive shaft 140. The protective tube 133 functions to prevent damage to the drive shaft 140 due to interference between the inner shaft 130 and the drive shaft 140.

[0049] An injection device D (see FIG. 1 ) that injects priming fluid during priming is connected to port 162. Injection device D includes a connector S1 connected to port 162, a tube S2 connected to connector S1, a three-way stopcock S3 connected to tube S2, and a first syringe S4 and a second syringe S5 that are connected to the three-way stopcock S3 and can inject priming fluid into port 162. The second syringe S5 has a larger capacity than the first syringe S4 and is used as an auxiliary syringe when, for example, the amount of priming fluid injected by the first syringe S4 is insufficient.

[0050] The connection pipe 164b holds the drive shaft 140 in order to transmit the rotation of the electrode terminal 165a and the optical connector 165b, which are rotationally driven by the external device 300, to the drive shaft 140. The coil shaft 141 and the light guide 143 are inserted inside the connection pipe 164b.

[0051] The connector unit 165 has an electrode terminal 165a electrically connected to the ultrasonic transmitter / receiver unit 145a, and an optical connector 165b connected to the light guide 143. A signal received by the ultrasonic transmitter / receiver unit 145a is transmitted to the external device 300 via the electrode terminal 165a, where it is subjected to predetermined processing and displayed as an image. A signal received by the optical transmitter / receiver unit 145b is transmitted to the external device 300 via the optical connector 165b, where it is subjected to predetermined processing and displayed as an image.

[0052] Referring again to FIG. 1, the diagnostic imaging catheter 100 is connected to and driven by an external device 300 .

[0053] As described above, the external device 300 is connected to the connector portion 165 provided on the proximal end side of the hub 160 .

[0054] The external device 300 also has a motor 300a, which is a power source for rotating the drive shaft 140, and a motor 300b, which is a power source for axially moving the drive shaft 140. The rotational motion of the motor 300b is converted into axial motion by a ball screw 300c connected to the motor 300b.

[0055] The operation of the external device 300 is controlled by a control device 301 electrically connected thereto. The control device 301 mainly includes a CPU (Central Processing Unit) and a memory. The control device 301 is electrically connected to a monitor 302.

[0056] The diagnostic imaging catheter 100 according to the present invention has been described above through the embodiments, but the present invention is not limited to the configurations described in the embodiments, and can be modified as appropriate based on the claims.

[0057] For example, in the above-described embodiment, the colored portion is formed over the entire area of ​​the second region 172. However, the colored portion may be formed at least at the leading edge of the second region 172.

[0058] In the above-described embodiment, the first region 171 and the second region 172 are provided spaced apart in the axial direction. However, as shown in Fig. 6, the first region 171 and the second region 172 may be connected to each other without being spaced apart in the axial direction. This configuration can prevent the guidewire W from unintentionally coming out from between the first region 171 and the second region 172, improving the operator's workability.

[0059] In the above-described embodiment, the pigment contained in the second region 172 contains titanium oxide, thereby providing the second region 172 with radiopaque properties. However, the pigment contained in the second region 172 does not necessarily need to contain titanium oxide. In this case, it is preferable that a marker having radiopaque properties is provided in the second region 172 of the guidewire insertion member 170. The marker is made of a metal coil having high radiopaque properties, such as Pt, Au, or Ir.

[0060] In the above-described embodiment, the diagnostic imaging catheter according to the present invention is described as being applied to a diagnostic imaging catheter having the functions of intravascular ultrasound (IVUS) and optical coherence tomography (OCT). However, the diagnostic imaging catheter according to the present invention may also be applied to a diagnostic imaging catheter having the functions of intravascular ultrasound (IVUS) and optical frequency domain imaging (OFDI). Furthermore, the diagnostic imaging catheter according to the present invention can also be applied to a diagnostic imaging catheter used solely for optical coherence tomography (OCT).

[0061] This application is based on Japanese Patent Application No. 2024-153689, filed on September 6, 2024, the disclosure of which is incorporated herein by reference in its entirety.

[0062] 100 Diagnostic imaging catheter, 110 Sheath, 110a Sensor lumen, 143 Light guide, 145b Light transmitting / receiving section, 170 Guide wire insertion member, 170a Guide wire lumen, 171 First region, 172 Second region, W Guide wire.

Claims

1. A diagnostic imaging catheter having: a sensor lumen into which a light guide body having a light transmitting and receiving unit connected to its tip for transmitting and receiving light is inserted; and a guide wire lumen into which a guide wire is inserted, wherein a guide wire insertion member constituting the guide wire lumen has: a first region that is adjacent to the sensor lumen in at least a part of the imaging area of ​​the light transmitting and receiving unit; and a second region that is provided on the tip side of the first region and is not adjacent to the sensor lumen; a colored portion is formed at at least the tip of the second region; and the first region is lighter in color than the colored portion of the second region.

2. The diagnostic imaging catheter according to claim 1, wherein the second region includes tungsten and titanium oxide.

3. The diagnostic imaging catheter according to claim 1 or 2, wherein the first region is made of only a resin material.

4. A diagnostic imaging catheter according to claim 1 or 2, wherein the colored portion is formed over the entire second region.

5. A diagnostic imaging catheter according to claim 1 or 2, wherein the first region and the second region are spaced apart from each other.

6. A diagnostic imaging catheter according to claim 1 or 2, wherein the first region and the second region are provided in communication with each other.

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