Diagnostic Imaging Catheters

Abstract

To provide a catheter for image diagnosis in which a drive shaft hardly buckles not only in an outer tube but also in an inner tube in a pushing operation.SOLUTION: A catheter for image diagnosis includes: an outer tube; a support tube provided more inward in the radial direction than the outer tube; a drive shaft provided more inward in the radial direction than the support tube; and an inner tube provided more inward in the radial direction than the outer tube, and more outward in the radial direction than the support tube, which can move relative to the outer tube and the support tube integrally with the drive shaft in the axial direction. The inner tube includes a part for forming a plurality of flow passages, which forms a central flow passage and one or more flow passages more outward in the radial direction than the central flow passage.SELECTED DRAWING: Figure 5A

Description

[Technical field]

[0001] The present disclosure relates to diagnostic imaging catheters. [Background technology]

[0002] Diagnostic imaging catheters generally have a pullback mechanism at their proximal end that changes the relative position between the sheath and the drive shaft in order to continuously observe cross sections inside the body cavity. The pullback mechanism has an outer tube and an inner tube that is located radially inward from the outer tube and radially outward from the drive shaft, and is movable in the axial direction relative to the outer tube and integrally with the drive shaft.

[0003] If the drive shaft buckles inside the outer tube during a pushing operation in which the pullback mechanism pushes the inner tube into the outer tube, there is a risk that the drive shaft will be twisted and broken when the drive shaft is driven to rotate. For this reason, for example, in the pullback mechanism described in Patent Document 1, a support tube that is movable axially together with the outer tube is provided radially outward from the drive shaft and radially inward from the inner tube in order to suppress buckling of the drive shaft during a pushing operation. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4672188 Summary of the Invention [Problem to be solved by the invention]

[0005] However, with a support tube such as that described in Patent Document 1, it is difficult to prevent the drive shaft from buckling within the inner tube during a pushing operation.

[0006] In view of the above, an object of the present disclosure is to provide a catheter for diagnostic imaging in which the drive shaft is less likely to buckle not only within the outer tube but also within the inner tube during a pushing operation. [Means for solving the problem]

[0007] A catheter for diagnostic imaging according to one embodiment of the present disclosure includes an outer tube, a support tube provided radially inward from the outer tube, a drive shaft provided radially inward from the support tube, and an inner tube provided radially inward from the outer tube and radially outward from the support tube and movable in the axial direction relative to the outer tube and the support tube and integrally with the drive shaft, wherein the inner tube has a multiple flow path forming portion that forms a central flow path and one or more flow paths radially outward from the central flow path.

[0008] As one embodiment of the present disclosure, the catheter for diagnostic imaging is a catheter for diagnostic imaging in which the multiple flow path forming portion has a portion that does not overlap with the support tube when viewed radially in a rearwardly retracted state in which the inner tube is pulled out most from within the outer tube.

[0009] As one embodiment of the present disclosure, the catheter for diagnostic imaging is a catheter for diagnostic imaging, in which the multiple flow path forming portion has a portion that overlaps with the support tube when viewed radially in a rearwardly retracted state in which the inner tube is pulled out most from within the outer tube.

[0010] As one embodiment of the present disclosure, the catheter for diagnostic imaging is a catheter for diagnostic imaging, in which the one or more flow paths are a plurality of flow paths arranged in a circumferential direction.

[0011] As one embodiment of the present disclosure, the catheter for diagnostic imaging is a catheter for diagnostic imaging in which the multiple flow path forming portion has a porous structure.

[0012] As one embodiment of the present disclosure, the catheter for diagnostic imaging is a catheter for diagnostic imaging, in which the multiple flow path forming portion has an inner wall that forms the central flow path and one or more connection portions that connect the inner wall to the tube main body portion. Effect of the Invention

[0013] According to the present disclosure, it is possible to provide a catheter for diagnostic imaging in which the drive shaft is less likely to buckle not only within the outer tube but also within the inner tube during a pushing operation. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a plan view showing a state in which an external device is connected to a catheter for diagnostic imaging as a first embodiment. [Figure 2A] FIG. 2 is a side view showing the diagnostic imaging catheter shown in FIG. 1 in a most advanced state before a pull-back operation. [Figure 2B] FIG. 2 is a side view showing the diagnostic imaging catheter shown in FIG. 1 in a most retreated state after a pull-back operation. [Diagram 3] FIG. 2 is a cross-sectional view showing the tip of the diagnostic imaging catheter shown in FIG. [Figure 4] FIG. 2 is a cross-sectional view showing the proximal end of the diagnostic imaging catheter shown in FIG. [Figure 5A] 2 is a cross-sectional view showing a pull-back mechanism of the diagnostic imaging catheter shown in FIG. 1 in a fully retracted state. FIG. [Figure 5B] 2 is a cross-sectional view showing the pull-back mechanism of the diagnostic imaging catheter shown in FIG. 1 in a most advanced state. FIG. [Figure 6A] 5B is a cross-sectional view taken along line AA in FIG. 5A. [Figure 6B] 6B is a cross-sectional view showing a modified example of the multiple flow path forming portion shown in FIG. 6A. [Figure 6C] 6B is a cross-sectional view showing another modified example of the multiple flow path forming portion shown in FIG. 6A. [Figure 6D] 6B is a cross-sectional view showing another modified example of the multiple flow path forming portion shown in FIG. 6A. [Figure 7] 6B is a cross-sectional view showing another modified example of the multiple flow path forming portion shown in FIG. 6A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0016] The diagnostic imaging catheter 1 according to this embodiment shown in FIG. 1 is a dual type that uses both intravascular ultrasound (IVUS) and optical coherence tomography (OCT). The dual type diagnostic imaging catheter 1 has three modes: a mode for acquiring a tomographic image only by IVUS, a mode for acquiring a tomographic image only by OCT, and a mode for acquiring a tomographic image by IVUS and OCT, and these modes can be switched for use. As shown in FIG. 1, the diagnostic imaging catheter 1 is connected to an external device 2 and driven. The diagnostic imaging catheter 1 and the external device 2 constitute an imaging diagnostic device 3.

[0017] The diagnostic imaging catheter 1 includes a sheath 4 inserted into a body cavity such as a blood vessel (blood vessel such as a coronary artery) of a living body, an outer tube 5 connected to a base end of the sheath 4, an inner tube 6 inserted into the outer tube 5 so as to be movable forward and backward, a unit connector 7 connected to the base end of the outer tube 5 and holding the inner tube 6 so as to be movable forward and backward, and a hub 8 connected to the base end of the inner tube 6. The diagnostic imaging catheter 1 also includes an imaging core 12 including a drive shaft 9, a housing 10 fixed to the tip of the drive shaft 9, and a signal transmitting / receiving unit 11 housed in the housing 10 and transmitting and receiving signals that are ultrasound and / or light. The imaging core 12 is inserted into the sheath 4, the outer tube 5, and the inner tube 6, and is movable forward and backward in the axial direction together with the inner tube 6 relative to the sheath 4 and the outer tube 5.

[0018] In this specification, the tip means the end of the diagnostic imaging catheter 1 that is inserted into a body cavity, the base end means the end of the diagnostic imaging catheter 1 that is held outside the body cavity, the axial direction means the direction along the central axis O of the drive shaft 9 (i.e., the extension direction of the drive shaft 9), the radial direction means the direction along a straight line perpendicular to the central axis O, and the circumferential direction means the direction going around the central axis O.

[0019] As shown in FIG. 2A, the drive shaft 9 passes through the sheath 4, the outer tube 5, and the inner tube 6 and extends to the inside of the hub 8. The hub 8, the inner tube 6, the drive shaft 9, the housing 10, and the signal transmitting / receiving unit 11 are connected to each other so as to be able to advance and retreat in the axial direction as a unit relative to the sheath 4 and the outer tube 5. For this reason, for example, when the hub 8 is pushed toward the distal end, that is, when a pushing operation is performed, the inner tube 6 connected to the hub 8 is pushed into the outer tube 5 and the unit connector 7, and the drive shaft 9, the housing 10, and the signal transmitting / receiving unit 11, that is, the imaging core 12, advance inside the sheath 4, that is, move toward the distal end. For example, when the hub 8 is pulled toward the proximal end, that is, when a pull-back operation is performed, the inner tube 6 is pulled out from the outer tube 5 and the unit connector 7 as shown by the arrow A1 in FIG. 1 and FIG. 2B, and the imaging core 12 moves inside the sheath 4 toward the proximal end as shown by the arrow A2.

[0020] 2A, when the inner tube 6 is pushed all the way toward the tip side and reaches its most advanced state, the tip of the inner tube 6 reaches near the relay connector 13. At this time, the signal transmitting / receiving unit 11 is located at the tip of the sheath 4 (near the lumen tip surface of the sheath 4). The relay connector 13 connects the sheath 4 and the outer tube 5.

[0021] 2B, a locking portion 14 for preventing the inner tube 6 from coming off is provided at the tip of the inner tube 6. The locking portion 14 prevents the inner tube 6 from coming off the outer tube 5. The locking portion 14 is configured to catch at a predetermined position on the inner wall of the unit connector 7 when the hub 8 is in the most retracted state where it is pulled all the way toward the base end, that is, when the inner tube 6 is pulled all the way out from the outer tube 5 and the unit connector 7.

[0022] As shown in FIG. 3, the drive shaft 9 is a long hollow member, and an electric signal line (electric cable) 15 and an optical signal line (optical fiber) 16 connected to the signal transmitting / receiving unit 11 are arranged inside the drive shaft 9.

[0023] The drive shaft 9 is formed of a coil shaft. Although not shown in the drawing, the coil shaft can be formed of, for example, a multi-layer coil with different winding directions. Each coil is made of metal such as stainless steel or Ni-Ti (nickel-titanium) alloy.

[0024] The signal transmitting / receiving unit 11 has an ultrasonic transmitting / receiving unit 11a for transmitting and receiving ultrasonic waves, and an optical transmitting / receiving unit 11b for transmitting and receiving light. The ultrasonic transmitting / receiving unit 11a has a transducer for transmitting ultrasonic waves based on a pulse signal into the body cavity and receiving ultrasonic waves reflected from the biological tissue in the body cavity. The transducer is electrically connected to an electric connector 15a (see FIG. 4) via an electric signal line 15. The transducer can be made of a piezoelectric material such as ceramics or quartz crystal.

[0025] The optical transmitter / receiver 11b has an optical element that transmits light into the body cavity and receives light reflected from biological tissue in the body cavity. The optical element is optically connected to an optical connector 16a (see FIG. 4) via an optical signal line 16. The optical element can be formed of a lens such as a ball lens.

[0026] The signal transmitting / receiving unit 11 is accommodated inside the housing 10. The base end of the housing 10 is fixed to the tip end of the drive shaft 9. The housing 10 is formed of a cylindrical metal tube, and an opening 10a is provided on the circumferential surface thereof so as not to impede the progress of the signal transmitted and received by the signal transmitting / receiving unit 11. The housing 10 can be formed, for example, by laser processing or the like. The housing 10 may also be formed by cutting out a metal block, MIM (metal powder injection molding), or the like.

[0027] A tip member 17 is provided at the tip of the housing 10. The tip member 17 has a substantially hemispherical outer shape, which suppresses friction and catching with the inner surface of the sheath 4. Note that a configuration without the tip member 17 may be adopted.

[0028] The sheath 4 has an inner cavity 4a into which the drive shaft 9 is inserted so as to be capable of advancing and retreating. A tubular guidewire insertion member 18 through which a guidewire can be passed is attached to the tip of the sheath 4, offset from the axis of the inner cavity of the sheath 4. The sheath 4 and the guidewire insertion member 18 are joined by welding or the like. The guidewire insertion member 18 is provided with a marker 19 having X-ray contrast properties. The marker 19 is made of a metal pipe having high X-ray opacity, such as Pt or Au.

[0029] A communication hole 20 that communicates between the inside and outside of the lumen 4a is formed at the tip of the sheath 4. A reinforcing member 21 joined to the guidewire insertion member 18 is provided at the tip of the lumen 4a of the sheath 4. A through hole is formed in the reinforcing member 21 that communicates between the lumen 4a, which is located on the proximal side of the reinforcing member 21, and the communication hole 20. The reinforcing member 21 does not necessarily have to be provided at the tip of the sheath 4.

[0030] The communication hole 20 is a priming liquid discharge hole for discharging the priming liquid. When using the diagnostic imaging catheter 1, when a priming process is performed to fill the sheath 4 with the priming liquid, the priming liquid can be discharged to the outside from the communication hole 20, and gas such as air can be discharged from the inside of the sheath 4 together with the priming liquid.

[0031] The distal end portion of the sheath 4, which is the range in which the signal transmitting / receiving unit 11 moves in the axial direction of the sheath 4, forms a window portion having higher signal permeability than other portions. The sheath 4, the guidewire insertion member 18, and the reinforcing member 21 are formed of a flexible material, and the material is not particularly limited, and examples thereof include 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 materials, and a combination of one or more of these (polymer alloy, polymer blend, laminate, etc.) can also be used.

[0032] 4, the hub 8 has a hub body 8a that is tubular and coaxial with the inner tube 6 and is detachably attached to the external device 2, a port 8b that protrudes radially outward from the hub body 8a and communicates with the inside of the hub body 8a, a connection pipe 8c that is attached to the outer circumferential surface of the drive shaft 9, a bearing 8d that rotatably supports the connection pipe 8c, a seal member (first seal member 8e) that prevents the priming liquid from leaking from between the connection pipe 8c and the bearing 8d toward the base end side, and a connector section 8f that includes an electric connector 15a and an optical connector 16a and is detachably attached to the first drive section 2a of the external device 2. The connector section 8f is rotatable together with the connection pipe 8c and the drive shaft 9.

[0033] The tip end of the hub body 8a is integrally connected to the base end of the inner tube 6. The drive shaft 9 is pulled out from the inner tube 6 inside the hub body 8a.

[0034] As shown in Fig. 1, an injection device 22 that injects a priming liquid when performing a priming process is connected to port 8b. The injection device 22 has a connector 22a that is connected to port 8b, and a syringe (not shown) that is connected to the connector 22a via a tube 22b. Priming is usually performed in the most retracted state (see Figs. 1 and 5A).

[0035] The external device 2 has a first drive unit 2a for driving the drive shaft 9 to rotate, and a second drive unit 2b for moving the drive shaft 9 in the axial direction (i.e., for pushing / pulling back operation). The first drive unit 2a can be configured, for example, by an electric motor. The second drive unit 2b can be configured, for example, by an electric motor and a linear motion conversion mechanism. The linear motion conversion mechanism can convert rotational motion into linear motion, and can be configured, for example, by a ball screw, a rack and pinion mechanism, or the like.

[0036] The operations of the first driving unit 2a and the second driving unit 2b are controlled by a control device 2c electrically connected thereto. The control device 2c includes a CPU (Central Processing Unit) and a memory. The control device 2c is electrically connected to a display 2d.

[0037] The signal received by the ultrasonic transmission / reception unit 11a is transmitted to the control device 2c via the electrical connector 15a, where it is subjected to a predetermined processing and displayed as an image on the display 2d. The signal received by the optical transmission / reception unit 11b is transmitted to the control device 2c via the optical connector 16a, where it is subjected to a predetermined processing and displayed as an image on the display 2d.

[0038] During diagnosis, the sheath 4 is inserted into the body cavity, and while the imaging core 12 is rotated and driven at a constant rotation speed of about 1000 to 10000 rpm by the first drive unit 2a of the external device 2, the imaging core 12 is pulled back at a constant speed within the inner cavity 4a of the sheath 4 by a pull-back operation by the second drive unit 2b of the external device 2. At this time, the signal transmitting and receiving unit 11 is transmitted and received by the control device 2c of the external device 2. Based on the signal received by scanning by the rotation and retreat of this signal, the state of the tissue around the body cavity is displayed as an image on the display 2d.

[0039] In this way, the diagnostic imaging catheter 1 has a pull-back mechanism 23 at its proximal portion for changing the relative position between the sheath 4 and the drive shaft 9 in order to continuously observe the cross section of the body cavity. As shown in Figs. 5A and 5B, the pull-back mechanism 23 has an outer tube 5, an inner tube 6 provided radially inward from the outer tube 5 and radially outward from the drive shaft 9 and movable in the axial direction relative to the outer tube 5 and integrally with the drive shaft 9, a support tube 24 provided radially inward from the inner tube 6 and radially outward from the drive shaft 9, a spacer 25 for integrally connecting the outer tube 5 and the support tube 24, a relay connector 13, and a unit connector 7. As described above, the relay connector 13 is integrally connected to the sheath 4, and the inner tube 6 is integrally connected to the hub 8. The unit connector 7 is provided with a seal member (second seal member 7a) for preventing the priming liquid from leaking from between the unit connector 7 and the inner tube 6 toward the base end side.

[0040] A locking portion 14 is provided at the tip of the inner tube 6. The locking portion 14 is configured as an expanded diameter portion where the outer circumferential surface of the inner tube 6 is expanded in diameter, and the rear end surface of the locking portion 14 protrudes radially outward from the outer circumferential surface of the inner tube 6 and forms an annular shape centered on the central axis O. The unit connector 7 has a stopper surface 7b that abuts against the rear end surface of the locking portion 14 to restrict further retraction of the inner tube 6. The inner tube 6 has a diameter dimension sufficient to provide the locking portion 14 with sufficient strength as a stopper.

[0041] In the pullback mechanism 23, the outer tube 5, the support tube 24, the inner tube 6 and the drive shaft 9 are arranged coaxially and have a common central axis O.

[0042] The intermediate connector 13 is cylindrical and has a cylindrical base-side inner circumferential surface 13a and a cylindrical tip-side inner circumferential surface 13c that is connected to the tip of the base-side inner circumferential surface 13a via an annular step portion 13b. The outer circumferential surface of the base end of the sheath 4 is joined to the tip-side inner circumferential surface 13c by welding or the like. The outer circumferential surface of the tip end of the outer tube 5 is joined to the base-side inner circumferential surface 13a by welding or the like.

[0043] The spacer 25 is cylindrical, and the outer peripheral surface of the spacer 25 contacts the inner peripheral surface of the tip of the outer tube 5, and the inner peripheral surface of the spacer 25 contacts the outer peripheral surface of the tip of the support tube 24. The outer peripheral surface of the spacer 25 is joined by welding or the like to the inner peripheral surface of the tip of the outer tube 5, and the inner peripheral surface of the spacer 25 is joined by welding or the like to the outer peripheral surface of the tip of the support tube 24. The spacer 25 is made of, for example, synthetic resin or metal.

[0044] The support tube 24 can be formed, for example, of a single layer or multiple layers of coil or tube. The support tube 24 is made, for example, of synthetic resin or metal. By using the coiled support tube 24, the priming liquid can pass through the support tube 24 in the radial direction, thereby facilitating priming in the outer tube 5. Instead of the coiled shape, the support tube 24 may be formed in a tubular shape with a mesh-like or other cutouts entirely or partially provided. The support tube 24 may also be formed in a tubular shape without cutouts. In this case, in order to promote priming in the outer tube 5, it is preferable to provide the spacer 25 with a flow path through which the priming liquid passes.

[0045] In this embodiment, the inner pipe 6 has a pipe main body portion 6a having a long cylindrical shape (long cylindrical shape in this embodiment) and a multiple flow passage forming portion 6b provided radially inward from the pipe main body portion. The multiple flow passage forming portion is a portion that forms a central flow passage 6c and one or more flow passages (hereinafter, also referred to as outer flow passages 6d) radially outward from the central flow passage 6c. More specifically, as shown in FIG. 6A, the multiple flow passage forming portion 6b has a cylindrical inner wall 6e centered on the central axis O and one or more connection portions 6f that connect the inner wall 6e to the pipe main body portion 6a. In this embodiment, each connection portion 6f is rib-shaped extending over the entire axial length of the inner wall 6e, and as a result, two outer flow passages 6d aligned in the circumferential direction are formed. Each connection portion 6f extends, for example, along the axial direction.

[0046] The circumferential arrangement of the rib-shaped connecting parts 6f is not particularly limited, and may be arranged, for example, 90° offset in the circumferential direction as shown in FIG. 6B. The number of outer flow paths 6d can be increased by increasing the number of rib-shaped connecting parts 6f. For example, four outer flow paths 6d can be provided as shown in FIG. 6C, or eight outer flow paths 6d can be provided as shown in FIG. 6D. By configuring the multiple flow path forming part 6b to form multiple outer flow paths 6d arranged in the circumferential direction, the rigidity of the inner pipe 6 can be efficiently increased, thereby making the inner pipe 6 thinner and increasing the flow path cross-sectional area. The multiple outer flow paths 6d are provided point-symmetrically with respect to the central axis O, but this is not limited thereto.

[0047] The pipe main body 6a, the inner wall 6e and the connecting portion 6f can be integrally formed, for example, by extrusion molding, etc. However, they may be formed separately and then integrated with an adhesive or the like.

[0048] A single outer flow passage 6d may be provided by providing one rib-like connecting portion 6f, or by providing the connecting portion 6f in a dot shape rather than in a rib shape.

[0049] The multiple flow passage forming portion 6b may have a porous structure. For example, a part or the whole of the multiple flow passage forming portion 6b having an inner wall 6e and one or more connection portions 6f may be formed of a porous body. Alternatively, as shown in FIG. 7, the multiple flow passage forming portion 6b may be formed of a long cylindrical porous body in contact with the inner peripheral surface of the pipe main body portion 6a. In this case, the central flow passage 6c is formed by the inner peripheral surface of the porous body, and the outer flow passages 6d are formed by a large number of cavities inside the porous body.

[0050] As shown in Fig. 5A, the multiple flow passage forming portion 6b is provided over the entire axial length of the pipe main body portion 6a. Therefore, the multiple flow passage forming portion 6b has a portion (hereinafter also referred to as a non-overlapping portion 6g) that does not overlap with the support tube 24 as viewed in the radial direction when the inner pipe 6 is in the most withdrawn state (state shown in Fig. 5A) in which the inner pipe 6 is pulled out most from inside the outer pipe 5. As a result, when the inner pipe 6 and the drive shaft 9 are advanced relative to the outer pipe 5 and the support tube 24 by a pushing operation from the most withdrawn state, the drive shaft 9 is supported from the radial outside by the support tube 24 to prevent the drive shaft 9 from buckling in the outer pipe 5 (for example, as shown by a two-dot chain line in Fig. 5A), and the drive shaft 9 is supported from the radial outside by the inner peripheral surface of the inner wall 6e of the non-overlapping portion 6g of the multiple flow passage forming portion 6b to prevent the drive shaft 9 from buckling in the inner pipe 6 (for example, as shown by a two-dot chain line in Fig. 5A). Therefore, the drive shaft 9 is rotated in a buckled state within the pullback mechanism 23, and the occurrence of breakage of the drive shaft 9 due to twisting can be suppressed.

[0051] As shown in FIG. 5A, the multiple flow passage forming portion 6b has a portion (hereinafter, also referred to as overlapping portion 6h) overlapping with the support tube 24 in the most retreated state when viewed in the radial direction. Therefore, when the inner tube 6 and the drive shaft 9 are advanced from the most retreated state relative to the outer tube 5 and the support tube 24 by a pushing operation, the support tube 24 is supported from the radially outer side by the inner peripheral surface of the inner wall 6e of the overlapping portion 6h of the multiple flow passage forming portion 6b, so that the support tube 24 can be prevented from buckling in the inner tube 6. Therefore, the drive shaft 9 is driven to rotate in a buckled state in the pullback mechanism 23, and the occurrence of breakage in which the drive shaft 9 is twisted off can be further prevented. From another perspective, when the inner tube 6 and the drive shaft 9 are advanced from the most retreated state relative to the outer tube 5 and the support tube 24 by a pushing operation, it is possible to prevent the base end of the support tube 24 and the tip end of the inner tube 6 from coming into contact with each other, which hinders the pushing operation.

[0052] The multiple flow passage forming portion 6b is not limited to a configuration that extends over the entire axial length of the pipe main body portion 6a, and may be, for example, a configuration that has a non-overlapping portion 6g without an overlapping portion 6h, or a configuration that has an overlapping portion 6h without a non-overlapping portion 6g. In either configuration, the multiple flow passage forming portion 6b can suppress the occurrence of breakage in which the drive shaft 9 is twisted off.

[0053] Furthermore, since the inner tube 6 has an outer flow path 6d, the priming liquid passes through the inner tube 6 more easily than in a configuration in which the inner diameter of the inner tube 6 is simply reduced, so that the priming resistance is reduced and good priming performance can be ensured.

[0054] The present disclosure is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit and scope of the present disclosure.

[0055] Therefore, the diagnostic imaging catheter 1 according to the above-described embodiment can be modified in various ways, for example as described below.

[0056] The diagnostic imaging catheter 1 according to the embodiment described above has an outer tube 5, a support tube 24 provided radially inward from the outer tube 5, a drive shaft 9 provided radially inward from the support tube 24, and an inner tube 6 provided radially inward from the outer tube 5 and radially outward from the support tube 24 and movable in the axial direction relative to the outer tube 5 and the support tube 24 and integrally with the drive shaft 9, and the inner tube 6 can be modified in various ways as long as it is a diagnostic imaging catheter 1 having a multiple flow path forming portion 6b that forms a central flow path 6c and one or more flow paths (outer flow paths 6d) radially outward from the central flow path 6c.

[0057] For example, the spacer 25 may not be provided, and the tip of the support tube 24 may be directly and integrally connected to the relay connector 13 or the outer tube 5 with an adhesive or the like.

[0058] The pullback mechanism 23 is not limited to a configuration in which the outer tube 5 is integrally connected to the relay connector 13 and the inner tube 6 is integrally connected to the hub 8, but may also be a configuration in which the outer tube 5 is integrally connected to the hub 8 and the inner tube 6 is integrally connected to the relay connector 13.

[0059] The diagnostic imaging catheter 1 is not limited to a dual type that uses both IVUS and OCT, but may be a type that uses only IVUS or only OCT.

[0060] In addition, it is preferable that the imaging diagnostic catheter 1 according to the above-mentioned embodiment is an imaging diagnostic catheter 1 in which the multiple flow path forming portion 6b has a portion (non-overlapping portion 6g) that does not overlap with the support tube 24 when viewed radially in the rearwardly retracted state in which the inner tube 6 is pulled out most from within the outer tube 5.

[0061] It is preferable that the imaging diagnostic catheter 1 according to the above-mentioned embodiment is an imaging diagnostic catheter 1 in which the multiple flow path forming portion 6b has a portion (overlapping portion 6h) that overlaps with the support tube 24 when viewed radially in the rearwardly retracted state in which the inner tube 6 is pulled out most from within the outer tube 5.

[0062] The diagnostic imaging catheter 1 according to the embodiment described above is preferably a diagnostic imaging catheter 1 in which one or more flow paths (outer flow path 6d) are a plurality of flow paths arranged in the circumferential direction.

[0063] The diagnostic imaging catheter 1 according to the above-described embodiment is preferably a diagnostic imaging catheter 1 in which the multiple flow path forming section 6b has a porous structure. [Explanation of symbols]

[0064] 1 Diagnostic imaging catheter 2 External device 2a First drive unit 2b Second drive unit 2c Control device 2D Display 3. Diagnostic imaging equipment 4 Sheath 4a Sheath lumen 5 Outer tube 6 Inner tube 6a Tube body 6b Multiple flow path forming section 6c Central channel 6d Outer channel 6e interior wall 6f Connection 6g Non-overlapping part 6h Overlapping part 7 Unit Connector 7a Second sealing member 7b Stopper surface 8. Hub 8a Hub body 8b port 8c Connecting pipe 8d Bearing 8e First sealing member 8f Connector part 9 Drive shaft 10. Housing 10a opening 11 Signal transmitter / receiver 11a Ultrasonic transmitter / receiver 11b Optical transmitter / receiver 12 Imaging Core 13 Relay connector 13a Proximal inner circumferential surface 13b Stepped section 13c Tip inner surface 14 Locking part 15 Electrical signal line 15a Electrical Connector 16 Optical signal line 16a Optical Connector 17 Tip member 18 Guide wire insertion member 19 Marker 20 Communication hole 21 Reinforcement members 22 Injection Device 22a Connector 22b tube 23 Pullback mechanism 24 Support tube 25 Spacer O center axis

Claims

1. an outer tube, a support tube provided radially inward from the outer tube, a drive shaft provided radially inward from the support tube, and an inner tube provided radially inward from the outer tube and radially outward from the support tube, and axially movable relative to the outer tube and the support tube and integrally with the drive shaft, The catheter for diagnostic imaging, wherein the inner tube has a multiple flow passage forming portion that forms a central flow passage and one or more flow passages radially outward from the central flow passage.

2. 2. The diagnostic imaging catheter according to claim 1, wherein the multiple flow passage forming portion has a portion that does not overlap with the support tube as viewed in a radial direction when the inner tube is in a most retracted state where the inner tube is pulled out most from within the outer tube.

3. 3. The catheter for diagnostic imaging according to claim 1, wherein the multiple flow passage forming portion has a portion overlapping with the support tube as viewed in a radial direction in a rearwardly retracted state in which the inner tube is pulled out most from within the outer tube.

4. The diagnostic imaging catheter according to any one of claims 1 to 3, wherein the one or more flow channels are a plurality of flow channels arranged in a circumferential direction.

5. The diagnostic imaging catheter according to any one of claims 1 to 4, wherein the multiple flow path forming portion has a porous structure.

6. The inner tube has a long cylindrical tube main body, The diagnostic imaging catheter according to any one of claims 1 to 5, wherein the multiple flow path forming portion has an inner wall that forms the central flow path, and one or more connection portions that connect the inner wall to the tube main body portion.

Images