Diagnostic imaging catheters

Abstract

To provide a catheter for diagnostic imaging which, even when an optical element of a light transmission and reception part is disposed at a position where an air trap is apt to occur, makes it easy to execute handling to suppress occurrence of an air trap.SOLUTION: The catheter for diagnostic imaging, which is configured for acquiring a tomographic image of a body cavity, comprises a long-sized sheath, a shaft disposed within the sheath, and an imaging core fixed to the distal end of the shaft. The imaging core comprises the light transmission and reception part with an optical element, an ultrasonic transmission and reception part, and a holding part capable of holding a light transmission member having flowability before hardening, at a position of covering the optical element of the light transmission and reception part.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] Diagnostic imaging devices have been widely used for the purposes of diagnosing arteriosclerosis, preoperative diagnosis for intravascular treatment, etc. Diagnostic imaging devices include intravascular ultrasound (IVUS) devices and optical coherence tomography (OCT) devices, or optical frequency domain imaging (OFDI) devices, each with different characteristics.

[0003] Furthermore, recently, diagnostic imaging devices that combine the functions of IVUS and OCT / OFDI have also been proposed (see, for example, Patent Documents 1 and 2). This type of diagnostic imaging device uses a diagnostic imaging catheter that is equipped with an ultrasonic transmitter / receiver for IVUS and an optical transmitter / receiver for OCT / OFDI inside a sheath inserted into a body cavity. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-56752 [Patent Document 2] Special Publication No. 2010-508973 Summary of the Invention [Problem to be solved by the invention]

[0005] In diagnostic imaging catheters equipped with an ultrasound transmitter / receiver and an optical transmitter / receiver, a priming process is required in advance to fill the sheath with a priming solution to suppress reflection of ultrasound at the interface between the ultrasound transmitter / receiver and air. During the priming process, air may remain in the sheath. For example, depending on the location of the optical transmitter / receiver of the diagnostic imaging catheter, such as when the optical element of the optical transmitter / receiver is placed in a recess, this air may easily remain as air bubbles in the sheath at a position covering the optical element of the optical transmitter / receiver (air trapping may occur). If air bubbles remain in the position covering the optical element of the optical transmitter / receiver, they may cause noise in optical coherence tomographic images, potentially preventing accurate images of the lesion.

[0006] The present disclosure aims to provide a catheter for diagnostic imaging that can easily implement measures to suppress the occurrence of air traps, even when the optical element of the light transmitting and receiving unit is placed in a position where air traps are likely to occur. [Means for solving the problem]

[0007] A diagnostic imaging catheter according to a first aspect of the present disclosure is a diagnostic imaging catheter for obtaining tomographic images of a body cavity, and comprises a long sheath, a shaft disposed within the sheath, and an imaging core fixed to the distal end of the shaft, wherein the imaging core comprises an optical transceiver unit having an optical element, an ultrasound transceiver unit, and a holding unit capable of holding a light-transmitting member in a pre-hardened, fluid state in a position covering the optical element of the optical transceiver unit.

[0008] In one embodiment of the present disclosure, the imaging core includes a housing that supports the optical transceiver unit and the ultrasonic transceiver unit, and the holding portion is a through hole formed in the housing at a position that covers the optical element of the optical transceiver unit.

[0009] In one embodiment of the present disclosure, the imaging core is provided with a contrast marker member having X-ray contrast properties proximal to the optical element of the optical transceiver unit, and the contrast marker member has an insertion hole through which a light-guiding member connected to the optical element of the optical transceiver unit is inserted.

[0010] In one embodiment of the present disclosure, the imaging core is arranged to cover the optical element of the optical transmitter / receiver and is provided with a contrast marker member having X-ray contrast properties, and the holding portion is a through hole formed in the contrast marker member at a position that covers the optical element of the optical transmitter / receiver.

[0011] In one embodiment of the present disclosure, the imaging core includes a housing that supports the optical transceiver and the ultrasonic transceiver, and the contrast marker member is supported by the housing.

[0012] In one embodiment of the present disclosure, the ultrasonic transmitter / receiver unit is located distal to the optical element of the optical transmitter / receiver unit, and the contrast marker member has an insertion hole through which an electrical signal line connected to the ultrasonic transmitter / receiver unit is inserted.

[0013] In one embodiment of the present disclosure, the optical element of the optical transceiver is a ball lens.

[0014] In one embodiment of the present disclosure, the imaging core includes the light-transmitting member held by the holding portion. [Effects of the Invention]

[0015] According to the present disclosure, it is possible to provide a catheter for diagnostic imaging that can easily take measures to suppress the occurrence of air traps, even when the optical element of the light transmitting and receiving unit is placed in a position where air traps are likely to occur. [Brief explanation of the drawings]

[0016] [Figure 1]1 is a diagram showing an imaging diagnostic device including a catheter for imaging diagnostics according to an embodiment of the present disclosure. [Figure 2A] FIG. 2 is a diagram showing the diagnostic imaging catheter shown in FIG. 1, illustrating a pushed-in state in which the inner tube is pushed most deeply into the outer tube. [Figure 2B] FIG. 2 is a diagram showing the diagnostic imaging catheter shown in FIG. 1, illustrating a state in which the inner tube is pulled out most from the outer tube. [Figure 3] FIG. 2 is a diagram showing the distal end of the diagnostic imaging catheter shown in FIG. 1. [Figure 4] FIG. 2 is a perspective view of an imaging core of the diagnostic imaging catheter shown in FIG. 1. [Figure 5] FIG. 2 is a top view of an imaging core of the diagnostic imaging catheter shown in FIG. 1. [Figure 6] FIG. 6 is a diagram showing the distal end of a diagnostic imaging catheter equipped with a holding portion as a modified example of the holding portion shown in FIGS. 3 to 5. [Figure 7] FIG. 7 is a top view of the imaging core of the diagnostic imaging catheter shown in FIG. 6. [Figure 8] FIG. 8 is a cross-sectional view taken along line II in FIG. 7. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of a catheter for diagnostic imaging according to the present disclosure will be described with reference to the drawings. In each drawing, the same components are designated by the same reference numerals.

[0018] Hereinafter, in this disclosure, the longitudinal direction of the diagnostic imaging catheter will be referred to as the "longitudinal direction A." In this disclosure, the side of the diagnostic imaging catheter in the longitudinal direction A that is inserted into a living body will be referred to as the "distal side." The side of the diagnostic imaging catheter in the longitudinal direction A that is operated outside the living body will be referred to as the "proximal side." The direction from the proximal side to the distal side of the diagnostic imaging catheter may be simply referred to as the "insertion direction A1." The direction from the distal end side to the proximal end side of the diagnostic imaging catheter may be simply referred to as the "removal direction A2."

[0019] First, an imaging diagnostic device 100 including a diagnostic imaging catheter 110 as one embodiment of the diagnostic imaging catheter according to the present disclosure will be described. Fig. 1 is a diagram showing the diagnostic imaging device 100. The diagnostic imaging device 100 includes the diagnostic imaging catheter 110 and an external device 120. Fig. 1 shows a state in which the diagnostic imaging catheter 110 is connected to the external device 120.

[0020] <Imaging diagnostic catheter 110> 2A and 2B are views showing the diagnostic imaging catheter 110 shown in FIG. 1 alone. As will be described in detail later, FIGS. 2A and 2B show different positions of the probe 10 in the longitudinal direction A within the sheath 20. FIG. 3 is a view showing the distal end (hereinafter referred to as the "distal end") of the diagnostic imaging catheter 110. The diagnostic imaging catheter 110 is configured to be able to acquire tomographic images of a body cavity. More specifically, the diagnostic imaging catheter 110 includes an ultrasound transmitting / receiving unit 61a for IVUS and an optical transmitting / receiving unit 61b for OCT / OFDI. As shown in FIG. 1, the diagnostic imaging catheter 110 is driven by being connected to an external device 120. More specifically, the diagnostic imaging catheter 110 of this embodiment is connected to a driving unit 120a of the external device 120.

[0021] As shown in FIGS. 1 to 3, the diagnostic imaging catheter 110 includes an insertion section 110a and an operation section 110b. The insertion section 110a is a section of the diagnostic imaging catheter 110 that is inserted into a body cavity such as a blood vessel inside a living body and used. The operation section 110b is a section of the diagnostic imaging catheter 110 that is operated outside the living body while the insertion section 110a is inserted into a body cavity. In the diagnostic imaging catheter 110 of this embodiment, the section distal to a distal connector 42 (described later) is the insertion section 110a, and the section proximal to the distal connector 42 is the operation section 110b.

[0022] 1 to 3, the insertion section 110a includes a distal portion of the probe 10 and a sheath 20. In this embodiment, the distal portion of the probe 10 included in the insertion section 110a is made up of the ultrasound transmitting and receiving unit 61a, the light transmitting and receiving unit 61b, a distal portion of the shaft 13, a distal portion of the electric signal line 14a, and a distal portion of the light-guiding member 14b.

[0023] The operation unit 110b can move the shaft 13 within the sheath 20 in the longitudinal direction of the sheath 20 (the same direction as the longitudinal direction A). As shown in FIGS. 1 to 3, the operation unit 110b includes a proximal portion of the probe 10, an inner tube 30, and an outer tube 40. In this embodiment, the proximal portion of the probe 10 included in the operation unit 110b is made up of a proximal portion of the shaft 13, a proximal portion of the electric signal line 14a, and a proximal portion of the light-guiding member 14b.

[0024] The inner tube 30 holds the proximal end of the probe 10 (hereinafter, the "proximal end" will be simply referred to as the "proximal end"). The outer tube 40 holds the proximal end of the sheath 20. As will be described in detail below, the inner tube 30 moves within the outer tube 40 in the direction of the central axis (the same direction as the longitudinal direction A), thereby allowing the probe 10 to move within the sheath 20 in the longitudinal direction A. Figure 2A shows a pushed-in state in which the inner tube 30 is pushed most distally into the outer tube 40. Figure 2B shows a pulled-out state in which the inner tube 30 is pulled most proximally from the outer tube 40.

[0025] 1 to 3, the diagnostic imaging catheter 110 of this embodiment includes a probe 10, a long sheath 20, an inner tube 30, and an outer tube 40. Each part of the diagnostic imaging catheter 110 of this embodiment will be described in detail below.

[0026] [Probe 10] 3, the probe 10 includes an imaging core 60, a shaft 13, and an electric signal line 14a and a light-guiding member 14b extending through the shaft 13. The imaging core 60 of this embodiment includes an ultrasound transmitting / receiving unit 61a, an optical transmitting / receiving unit 61b, a contrast marker member 61c, a housing 61d, a tip member 61e, and a light-transmitting member X.

[0027] FIG. 4 is a perspective view of the imaging core 60. FIG. 5 is a top view of the imaging core 60. For ease of explanation, the light-transmitting member X held in the through-hole 61d2 is omitted from FIGS. 4 and 5. As shown in FIGS. 3 to 5, the imaging core 60 is fixed to the distal end of the shaft 13. The ultrasound transmitting / receiving unit 61a of the imaging core 60 of this embodiment includes an ultrasound transducer 62. The ultrasound transducer 62 is capable of transmitting ultrasound based on a pulse signal into the body cavity and receiving ultrasound reflected from biological tissue within the body cavity. The ultrasound transducer 62 of this embodiment includes a main body 62a and an electrode 62b. The main body 62a includes a piezoelectric element. The piezoelectric element includes a piezoelectric material such as ceramics or quartz. The ultrasound transmitting / receiving unit 61a can transmit and receive ultrasound using the ultrasound transducer 62. The ultrasound transmitting / receiving unit 61a is located distal to an optical element 61b1 (described later) of the optical transmitting / receiving unit 61b.

[0028] The optical transceiver 61b is capable of continuously transmitting the transmitted light into the body cavity and continuously receiving the light reflected by the biological tissue inside the body cavity. The optical transceiver 61b includes an optical element 61b1. The optical element 61b1 is connected to the distal end of the light-guiding member 14b and has a lens function for focusing light and a reflecting function for reflecting light.

[0029] The optical element 61b1 of this embodiment is a Bose lens including a flat surface portion 65a inclined with respect to the longitudinal direction A and a spherical surface portion 65b. The flat surface portion 65a is coated with a reflective coating that reflects light propagating from the light-guiding member 14b. The material of the reflective coating is not particularly limited as long as it is capable of reflecting light, and examples thereof include aluminum. The light propagating from the light-guiding member 14b is reflected by the flat surface portion 65a, collected by the spherical surface portion 65b, and transmitted into the body cavity. The light reflected by the biological tissue in the body cavity is collected by the spherical surface portion 65b, reflected by the flat surface portion 65a, and propagated to the light-guiding member 14b. In this manner, the optical transceiver 61b can transmit and receive light via the optical element 61b1.

[0030] The radiopaque marker member 61c has radiopaque properties. Specifically, the radiopaque marker member 61c is made of a material that is highly opaque to X-rays. Specifically, the radiopaque marker member 61c can be made of a material that is highly opaque to X-rays, such as platinum, gold, iridium, or tungsten.

[0031] As shown in FIG. 3, the contrast marker member 61c has an insertion hole 61c1 through which the light guide member 14b is inserted in the longitudinal direction A, and an insertion hole 61c2 through which the electric signal line 14a is inserted in the longitudinal direction A formed therein.

[0032] The radiopaque marker member 61c of this embodiment is disposed proximal to the optical element 61b1 of the light transmitting and receiving unit 61b. The radiopaque marker member 61c of this embodiment is fixed to the housing 61d. More specifically, the radiopaque marker member 61c of this embodiment is fixed to the housing 61d within a proximal tube portion 12b (described later) of the housing 61d. The light guiding member 14b is supported in a state where it is inserted through an insertion hole 61c1 of the radiopaque marker member 61c fixed to the housing 61d. As a result, the light transmitting and receiving unit 61b connected to the light guiding member 14b is positioned within the housing 61d.

[0033] The housing 61d directly or indirectly supports the ultrasound transmitting / receiving unit 61a, the light transmitting / receiving unit 61b, and the contrast marker member 61c. The proximal side of the housing 61d is connected to the shaft 13. The housing 61d may be integrated with the shaft 13. Therefore, the housing 61d may be directly connected to the shaft 13 by adhesive or the like, or may be indirectly connected to the shaft 13 via a connector or the like.

[0034] As shown in FIGS. 4 and 5, the housing 61d of this embodiment includes a distal cylindrical portion 12a, a proximal cylindrical portion 12b, and a support plate portion 12c.

[0035] The distal tube portion 12a constitutes the distal end of the housing 61d. The distal tube portion 12a is located distal to the ultrasonic transceiver unit 61a and the optical transceiver unit 61b. The proximal tube portion 12b constitutes the proximal end of the housing 61d. The proximal tube portion 12b of this embodiment is located proximal to the ultrasonic transceiver unit 61a. The proximal tube portion 12b of this embodiment covers the periphery of the optical element 61b1 of the optical transceiver unit 61b. As will be described in detail later, the proximal tube portion 12b has a through-hole 61d2 as a holding portion 70 formed in a position that covers the optical element 61b1. More specifically, the through-hole 61d2 of this embodiment is formed in a position that covers the spherical portion 65b of the ball lens that serves as the optical element 61b1. The support plate portion 12c is a curved plate portion that is continuous with the peripheral wall of the distal tube portion 12a and the peripheral wall of the proximal tube portion 12b. In other words, the housing 61d of this embodiment is a cylindrical body having a window 61d1 formed by cutting out a portion of the peripheral wall of the cylindrical body. The ultrasonic transmitter / receiver 61a can transmit ultrasonic waves based on a pulse signal into the body cavity through the window 61d1. The ultrasonic transmitter / receiver 61a can also receive ultrasonic waves reflected from biological tissue in the body cavity through the window 61d1.

[0036] The support plate 12c supports the ultrasonic transmitter / receiver unit 61a via a backing member 80. The backing member 80 scatters and attenuates ultrasonic waves traveling from the ultrasonic transmitter / receiver unit 61a in the direction opposite to the window 61d1 of the housing 61d. The method for fixing the backing member 80 to the support plate 12c is not particularly limited. The backing member 80 may be fixed to the support plate 12c by, for example, bonding with an adhesive. The backing member 80 of this embodiment supports the ultrasonic transmitter / receiver unit 61a so that the ultrasonic transmitter / receiver unit 61a can transmit ultrasonic waves in a direction inclined with respect to the longitudinal direction A.

[0037] The housing 61d may be formed by, for example, cutting out a metal block or by MIM (metal powder injection molding).

[0038] The tip member 61e is fixed to the distal side of the housing 61d. The tip member 61e has a substantially hemispherical outer shape. By providing the tip member 61e, friction and snagging with the inner surface of the sheath 20 can be reduced. The tip member 61e of this embodiment may be configured by, for example, a coil. Also, the tip member 61e may be formed integrally with the housing 61d. Furthermore, the imaging core 60 does not have to include the tip member 61e.

[0039] The light transmitting member X is disposed in a position covering the optical element 61b1 of the light transmitting / receiving unit 61b. In this embodiment, the light transmitting member X is held in a through-hole 61d2 formed in the housing 61d at a position covering the optical element 61b1. As described above, for convenience of explanation, the light transmitting member X held in the through-hole 61d2 is omitted from FIGS. 4 and 5 . The light transmitting member X can be made of a material having an absolute refractive index substantially equal to that of the priming liquid. In this way, even when the light transmitting member X covers the optical element 61b1, an optical coherence tomographic image can be generated with the same resolution as when the light transmitting member X does not cover the optical element 61b1.

[0040] The light-transmitting member X is made of a material that can be cured from a fluid state by using various methods. The various methods for curing the light-transmitting member X are not particularly limited, but examples thereof include heat curing and UV curing. The light-transmitting member X may be, for example, an adhesive.

[0041] The light transmitting member X is filled into the through-hole 61d2 in a fluid state before hardening. The through-hole 61d2 is configured to be able to hold the light transmitting member X in a fluid state before hardening. This will be described in detail later.

[0042] As shown in FIGS. 2A, 2B, and 3, the shaft 13 is disposed within the sheath 20. The shaft 13 is formed of a flexible tubular body. As shown in FIG. 3, an electric signal line 14a connected to the ultrasound transmitting / receiving unit 61a of the imaging core 60 is disposed within the shaft 13. Also, as shown in FIG. 3, a light-guiding member 14b connected to the optical transmitting / receiving unit 61b of the imaging core 60 is disposed within the shaft 13. The shaft 13 may be formed, for example, of a multi-layer coil wound in different directions around the axis. The shaft 13 of this embodiment is formed of a three-layer coil. Examples of materials for the coil include stainless steel and Ni-Ti (nickel-titanium) alloy.

[0043] 2A, 2B, and 3, the shaft 13 extends through the inside of the sheath 20, the inner tube 30, and the outer tube 40. As described above, the distal end of the shaft 13 is connected to the housing 61d of the imaging core 60. The proximal end of the shaft 13 is held by a hub 32 (described below) that constitutes the proximal end of the inner tube 30. In other words, the shaft 13 extends in the longitudinal direction A from the distal end of the insertion section 110a to the proximal end of the operation section 110b.

[0044] As shown in FIG. 3, the electric signal line 14a extends within the shaft 13. The electric signal line 14a electrically connects the ultrasonic transmitter / receiver unit 61a of the imaging core 60 to the external device 120 (see FIG. 1). That is, like the shaft 13, the electric signal line 14a extends in the longitudinal direction A from the distal end of the insertion section 110a to the proximal end of the operation section 110b. A plurality of electric signal lines 14a (two in this embodiment) are provided, and as shown in FIGS. 4 and 5, each electric signal line 14a is connected to an electrode 62b of the ultrasonic transmitter / receiver unit 61a of the imaging core 60. The plurality of electric signal lines 14a may be formed, for example, by a twisted pair cable in which two electric signal lines 14a are twisted together. Each electric signal line 14a may be a flexible thin wire member having an outer diameter greater than 0 mm and equal to or less than 0.1 mm. Each of the electric signal lines 14a can be configured, for example, by a conductor and a covering material made of an insulating material that covers the conductor.

[0045] As shown in Fig. 3, the light-guiding member 14b extends inside the shaft 13. The light-guiding member 14b optically connects the light transmitting / receiving unit 61b of the imaging core 60 and the external device 120 (see Fig. 1). That is, like the shaft 13, the light-guiding member 14b extends in the longitudinal direction A from the distal end of the insertion section 110a to the proximal end of the operation section 110b. As shown in Fig. 3, the light-guiding member 14b is connected to the optical element 61b1 of the light transmitting / receiving unit 61b of the imaging core 60. The light-guiding member 14b is, for example, an optical fiber.

[0046] [Sheath 20] The sheath 20 is an elongated member that is inserted into a body cavity such as a blood vessel. As shown in FIGS. 2A, 2B, and 3, the sheath 20 includes a main body 20a and a guidewire insertion portion 20b. A first hollow portion 21a is defined inside the main body 20a. A second hollow portion 21b is defined in the guidewire insertion portion 20b. A probe 10 is housed in the first hollow portion 21a of the main body 20a. The probe 10 can move back and forth in the longitudinal direction A within the first hollow portion 21a. A guidewire W can be inserted into the second hollow portion 21b of the guidewire insertion portion 20b. As shown in FIG. 3, the guidewire insertion portion 20b may be provided with a contrast marker portion 23 that is radiopaque. The contrast marker portion 23 can be configured, for example, by a metal pipe or metal coil having high radiopaqueness, such as platinum, gold, iridium, or tungsten. In this embodiment, as shown in Fig. 3, the tubular guidewire insertion portion 20b is adjacent to the distal end of the tubular main body portion 20a so as to be parallel to each other. The main body portion 20a and the guidewire insertion portion 20b may be formed by joining different tubular members together by heat fusion or the like.

[0047] In addition, a communication hole 22a1 that connects the inside and outside of the first hollow portion 21a is formed in the distal end of the main body portion 20a in this embodiment. Furthermore, a reinforcing member 22 for firmly joining and supporting the guidewire insertion portion 20b is provided in the distal end of the main body portion 20a. A communication passage 22a that connects the inside of the first hollow portion 21a, which is located on the proximal side of the reinforcing member 22, with the communication hole 22a1 is formed in the reinforcing member 22. However, the reinforcing member 22 does not necessarily have to be provided in the distal end of the main body portion 20a.

[0048] The communication hole 22a1 is a priming liquid discharge hole for discharging the priming liquid. When using the diagnostic imaging catheter 110, a priming process is performed to fill the main body 20a of the sheath 20 with the priming liquid. For example, if ultrasound is transmitted without filling the main body 20a of the sheath 20 with the priming liquid, the ultrasound is likely to be reflected at the interface between the matching layer and the air due to the large difference in acoustic impedance between the matching layer and the air, which is disposed on the surface of the main body 62a of the ultrasonic transducer 62 of the ultrasound transmitting / receiving unit 61a. In contrast, the reflection can be suppressed by filling the main body 20a of the sheath 20 with a priming liquid whose acoustic impedance is close to that of the matching layer. During the priming process, the priming liquid can be discharged to the outside through the communication hole 22a1, thereby discharging gases such as air from the main body 20a of the sheath 20 along with the priming liquid.

[0049] The sheath 20 and the reinforcing member 22 are preferably formed of a flexible material, but the material is not particularly limited. Examples of the constituent materials 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. Combinations of one or more of these materials (polymer alloys, polymer blends, laminates, etc.) may also be used. The outer surface of the sheath 20 may also be provided with a hydrophilic lubricating coating layer that exhibits lubricity when wet.

[0050] [Inner tube 30 and outer tube 40] The inner tube 30 accommodates the proximal end of the shaft 13 and is movable within the outer tube 40 together with the shaft 13. As shown in FIGS. 1, 2A, and 2B, the inner tube 30 includes an inner tube body 31 and a hub 32. The inner tube body 31 is inserted within the outer tube 40 so as to be movable back and forth. The hub 32 is connected to the proximal side of the inner tube body 31.

[0051] As shown in FIGS. 1, 2A, and 2B, the outer tube 40 is fixed to the proximal end of the sheath 20. The outer tube 40 of this embodiment includes an outer tube main body 41, a distal connector 42, and a proximal connector 43. The outer tube main body 41 is located radially outside the inner tube main body 31, and the inner tube main body 31 moves back and forth within the outer tube main body 41. The distal connector 42 connects the proximal end of the main body 20a of the sheath 20 to the distal end of the outer tube main body 41. The proximal connector 43 is fixed to the proximal end of the outer tube main body 41.

[0052] The shaft 13, electrical signal line 14a, and light-guiding member 14b of the probe 10 described above extend from the main body 20a of the sheath 20, through the outer tube 40 connected to the proximal side of the main body 20a, to the hub 32 that constitutes the proximal end of the inner tube 30.

[0053] The probe 10 and the inner tube 30 are connected to each other so that they can integrally move forward and backward in the longitudinal direction A. Therefore, for example, when the inner tube 30 is pushed in the insertion direction A1, the inner tube 30 is pushed into the outer tube 40 in the insertion direction A1. When the inner tube 30 is pushed into the outer tube 40 in the insertion direction A1, the probe 10 connected to the inner tube 30 moves in the insertion direction A1 within the main body portion 20a of the sheath 20. This results in the pushed-in state shown in FIG. 2A. When the inner tube 30 is pulled in the withdrawal direction A2 from the pushed-in state shown in FIG. 2A, the inner tube 30 is withdrawn from the outer tube 40 in the withdrawal direction A2. When the inner tube 30 is withdrawn from the outer tube 40 in the withdrawal direction A2, the probe 10 connected to the inner tube 30 moves in the withdrawal direction A2 within the main body portion 20a of the sheath 20. This results in the withdrawn state shown in FIG. 2B.

[0054] 2A , when the inner tube 30 is pushed in the insertion direction A1 to the maximum, the distal end of the inner tube 30 reaches near the distal connector 42 of the outer tube 40. At this time, the imaging core 60 of the probe 10 is located near the distal end of the main body 20 a of the sheath 20.

[0055] <External device 120> 1, external device 120 includes motor 121, which is a power source for rotating shaft 13 (see FIG. 2A, etc.), and motor 122, which is a power source for moving shaft 13 in longitudinal direction A. The rotational motion of motor 122 is converted into axial motion by ball screw 123 connected to motor 122.

[0056] More specifically, the external device 120 of this embodiment includes a drive unit 120a, a control device 120b electrically connected to the drive unit 120a by wire or wirelessly, and a monitor 120c capable of displaying an image generated by the control device 120b based on ultrasonic and optical reception signals received from the diagnostic imaging catheter 110. The motor 121, motor 122, and ball screw 123 described above in this embodiment are provided in the drive unit 120a. The operation of the drive unit 120a is controlled by the control device 120b. The control device 120b can be configured by a processor including a CPU and a memory.

[0057] The external device 120 is not limited to the configuration shown in this embodiment, and may be configured to further include an external input unit such as a keyboard.

[0058] Hereinafter, the details of the holding portion 70 in the imaging core 60 of the diagnostic imaging catheter 110 of this embodiment will be described with reference to FIGS.

[0059] The imaging core 60 includes a holding portion 70 capable of holding the light transmitting member X in a pre-hardened, fluid state at a position covering the optical element 61b1 of the light transmitting and receiving unit 61b. By providing such a holding portion 70, even when the optical element 61b1 of the light transmitting and receiving unit 61b is disposed at a position where air traps are likely to occur, the light transmitting member X can be held by the holding portion 70, making it possible to easily implement measures to prevent air traps from occurring.

[0060] Specifically, in this embodiment, the optical element 61b1 of the optical transceiver 61b does not protrude outward from the annular imaginary surface of the housing 61d, but is positioned inside the annular imaginary surface of the housing 61d. The annular imaginary surface of the housing 61d refers to an annular surface formed by the path of the outer surface of the housing 61d when the housing 61d rotates around the central axis O of the shaft 13. More specifically, in this embodiment, the optical element 61b1 of the optical transceiver 61b is disposed inside the cylindrical body that is the housing 61d. This arrangement prevents the optical element 61b1 from sliding against the inner surface of the sheath 20. Furthermore, the position of the optical element 61b1 approaches the central axis O of the shaft 13. This allows the rotational center axis of the optical element 61b1 to be brought closer to the central axis O, which is the rotational center line of the shaft 13.

[0061] On the other hand, if the optical element 61b1 of the optical transceiver 61b is disposed inside the cylindrical housing 61d, the housing 61d needs to have an opening to allow the optical transceiver 61b to transmit and receive light. That is, the optical transceiver 61b can transmit light through the opening toward the outside in the radial direction of the shaft 13 (the radial direction of an imaginary circle around the central axis O of the shaft 13). The optical transceiver 61b can also receive light reflected by biological tissue within the body cavity through the opening. The presence of such an opening creates a depression at the position of the opening, making it more likely that an air trap will occur. Air bubbles trapped at the opening cause noise in optical coherence tomographic images, which may prevent accurate images of the lesion from being obtained.

[0062] Furthermore, the imaging core 60 has a small structure that can be inserted into a body cavity such as a blood vessel, etc. Therefore, the amount of depression at the position of the opening may vary even during manufacturing.

[0063] For the above reasons, even if the optical element 61b1 of the optical transmitter / receiver 61b is placed in a position where air traps are likely to occur due to variations in manufacturing, it is desirable to have a configuration in place that can take measures to suppress the occurrence of air traps.

[0064] Therefore, in this embodiment, the opening of the housing 61d, which is formed at a position that covers the optical element 61b1 so that the light transmitting / receiving unit 61b can transmit and receive light, is configured with a through-hole 61d2 serving as a holder 70 that can hold the light transmitting member X in a fluid state before hardening. If the through-hole 61d2 is a location where air traps are likely to occur due to, for example, variations during manufacturing, the through-hole 61d2 can be filled with the light transmitting member X in a fluid state before hardening. In this way, the through-hole 61d2 is filled with the light transmitting member X, thereby preventing air traps from occurring in the through-hole 61d2.

[0065] In this embodiment, the holding portion 70 is a through-hole 61d2 formed in the housing 61d at a position covering the optical element 61b1 of the optical transceiver 61b, but the configuration of the holding portion 70 is not particularly limited. The holding portion 70 provided in the imaging core 60 may be any member as long as it can hold the pre-cured, fluid light-transmitting member X at a position covering the optical element 61b1 of the optical transceiver 61b. However, the holding portion 70 is preferably formed as a through-hole, such as the through-hole 61d2 of the housing 61d in this embodiment. Using a through-hole for the holding portion 70 makes it easier to adjust the filling amount of the light-transmitting member X and to accommodate dimensional tolerances due to, for example, manufacturing variations. Furthermore, when the holding portion 70 is formed as a through-hole 61d2 in the housing 61d, as in this embodiment, the holding portion 70 can be easily formed. Other examples of through-holes that form the holding portion 70 will be described later (see FIGS. 6 to 8).

[0066] Furthermore, the holding unit 70 preferably includes a blocking portion to prevent the light transmitting member X, which is in a fluid state before hardening, from moving toward the ultrasonic transmitter-receiver 61a. In the through-hole 61d2 serving as the holding unit 70 of this embodiment, the distal portion of the inner surface forms a blocking portion that restricts the light transmitting member X from moving toward the ultrasonic transmitter-receiver 61a.

[0067] Next, a through-hole 61c4 will be described as an example of another through-hole constituting the holding portion 70 with reference to Fig. 6 to Fig. 8. Fig. 6 is a diagram showing the distal end of the diagnostic imaging catheter 110 having the through-hole 61c4 as the holding portion 70. Fig. 7 is a top view of the imaging core 60 of the diagnostic imaging catheter 110 shown in Fig. 6. Fig. 8 is a cross-sectional view taken along line II in Fig. 7.

[0068] The diagnostic imaging catheter 110 shown in Figures 6 to 8 is different from the configuration shown in Figures 1 to 5 in the configuration of the imaging core 60, but the other configurations are the same. Therefore, only the differences will be described here.

[0069] 6 to 8 includes an ultrasound transmitting / receiving unit 61a, an optical transmitting / receiving unit 61b, a radiopaque marker member 61c, a housing 61d, a tip member 61e, and a light-transmitting member X. In the imaging core 60 shown in FIGS. 6 to 8, a notch 12b1 is formed in a part of the circumferential direction of the distal end of the proximal tube portion 12b of the housing 61d. The radiopaque marker member 61c, which is radiopaque, is supported by the housing 61d by being fixed at the position of this notch 12b1 to a substantially C-shaped circumferential wall portion 12b2 that is adjacent to the notch 12b1 in the circumferential direction.

[0070] 6 to 8 is disposed so as to cover the optical element 61b1 of the optical transmitter / receiver 61b. The holding portion 70 of the imaging core 60 shown in FIGS. 6 to 8 is a through-hole 61c4 formed in the contrast marker member 61c at a position that covers the optical element 61b1 of the optical transmitter / receiver 61b. More specifically, the through-hole 61c4 shown in FIGS. 6 to 8 is formed at a position that covers the spherical portion 65b of the ball lens serving as the optical element 61b1.

[0071] As described above, in the imaging core 60 shown in FIGS. 6 to 8, the optical element 61b1 of the optical transceiver 61b is surrounded by the radiopaque marker member 61c. The radiopaque marker member 61c has a through-hole 61c4 serving as a holder 70 at a position radially outward of the shaft 13 relative to the optical element 61b1. In other words, the radiopaque marker member 61c shown in FIGS. 6 to 8 defines a housing portion 61c3 that houses the optical element 61b1. The optical transceiver 61b is positioned in the housing 61d by being supported with the optical element 61b1 housed in the housing portion 61c3 of the radiopaque marker member 61c. The through-hole 61c4 extends radially outward from one end connected to the housing portion 61c3 of the radiopaque marker member 61c. The other end of the through-hole 61c4 is an opening formed on the outer surface of the radiopaque marker member 61c at the position of the notch 12b1 of the housing 61d.

[0072] As shown in FIGS. 6 to 8, the light transmitting member X is held in the through-hole 61c4 serving as the holding portion .

[0073] In this way, the holding portion 70 may be configured by a through-hole 61c4 formed in the radiopaque marker member 61c. In this case, the position of the radiopaque marker member 61c and the position of the optical element 61b1 can be aligned in the longitudinal direction A. Therefore, by checking the position of the radiopaque marker member 61c using an angiography device or the like, the accurate position of the optical element 61b1 can be determined.

[0074] 6 to 8 is also located distal to the optical element 61b1 of the optical transceiver 61b. Therefore, as shown in FIG. 8, the contrast marker member 61c has an insertion hole 61c2 through which the electric signal line 14a connected to the ultrasonic transceiver 61a is inserted. As shown in FIG. 8, the housing 61c3 that houses the optical element 61b1 is not disposed on the central axis O of the shaft 13, but is located radially outward of the central axis O of the shaft 13. This makes it easier to secure the insertion hole 61c2 through which the electric signal line 14a is inserted. The same applies to the diagnostic imaging catheter 110 shown in FIGS. 1 to 5.

[0075] The diagnostic imaging catheter according to the present disclosure is not limited to the specific configurations shown in the above-described embodiments and modified examples, and various modifications, changes, and combinations are possible without departing from the scope of the claims. [Industrial Applicability]

[0076] The present disclosure relates to diagnostic imaging catheters. [Explanation of symbols]

[0077] 10: Probe 12a: Distal tube 12b: Proximal barrel 12b1: Notch 12b2: Peripheral wall part 12c: Support plate part 13: Shaft 14a: Electrical signal line 14b: Light guide member 20: Sheath 20a: Main body 20b: Guide wire insertion section 21a: 1st hollow part 21b: Second hollow part 22: Reinforcement member 22a: Communication path 22a1: Communication hole 23: Contrast marker section 30: Inner tube 31: Inner pipe body 32: Hub 40:Outer tube 41:Outer tube body 42: Distal connector 43: Proximal connector 60: Imaging Core 61a: Ultrasonic transmitter / receiver 61b: Optical transmitter / receiver 61b1: Optical elements 61c: contrast marker member 61c1, 61c2: Insertion holes 61c3: Containment unit 61c4: Through hole (an example of a holding portion) 61d: Housing 61d1: Window section 61d2: Through hole (an example of a holding portion) 61e: Tip member 62: Ultrasonic vibrator 62a: Main body 62b: Electrode 65a: Flat part 65b: Spherical part 70: Holding part 80: Backing material 100: Diagnostic imaging equipment 110: Diagnostic imaging catheter 110a: Insertion part 110b: Operation unit 120: External device 120a: Drive unit 120b: Control device 120c:Monitor 121, 122: Motor 123: Ball screw A: Longitudinal direction of diagnostic imaging catheter A1: Insertion direction A2: Removal direction O: Center axis of shaft W: Guidewire X: Light-transmitting material

Claims

1. A diagnostic imaging catheter for acquiring a tomographic image of a body cavity, A long sheath; a shaft disposed within the sheath; an imaging core secured to the distal end of the shaft; The imaging core is an optical transceiver unit including an optical element; an ultrasonic transmitting and receiving unit; a holding unit capable of holding a light transmitting member in a fluid state before hardening at a position covering the optical element of the light transmitting and receiving unit, the imaging core is disposed so as to cover the optical element of the optical transceiver unit and includes a contrast marker member having X-ray contrast properties; The catheter for diagnostic imaging, wherein the holding portion is a through-hole formed in the contrast marker member at a position that covers the optical element of the light transmitting and receiving portion.

2. the imaging core includes a housing supporting the optical transceiver and the ultrasonic transceiver; The diagnostic imaging catheter according to claim 1 , wherein the contrast marker member is supported by the housing.

3. the ultrasonic transmitting and receiving unit is located distal to the optical element of the optical transmitting and receiving unit; 3. The diagnostic imaging catheter according to claim 1, wherein the contrast marker member has an insertion hole through which an electric signal line connected to the ultrasound transmitting / receiving unit is inserted.

4. The diagnostic imaging catheter according to claim 1 , wherein the optical element of the optical transmitter / receiver is a ball lens.

5. The diagnostic imaging catheter according to claim 1 , wherein the imaging core includes the light-transmitting member held by the holding portion.

Images