Image acquisition catheter

Abstract

[Problem] To provide an image acquisition catheter capable of preventing breakage from occurring in the vicinity of a connection position where a support body of a sensor part and an outer tube are connected. [Solution] An image acquisition catheter 100 comprises: an inner tube 10 which is provided with a first lumen 15 extending in the axial direction; a sensor part 20 which is disposed at the distal end 11 of the inner tube and in which a plurality of transducers 37a for transmitting and receiving ultrasonic waves are disposed in a ring shape in the circumferential direction; and an outer tube 70 which is disposed in a state of covering at least a portion of the inner tube to form a second lumen 75 between the outer tube and the inner tube. The sensor part has a film sensor 30 in which the plurality of transducers are disposed, and a support body 40 which supports the film sensor. The film sensor has a rib part 35a which is disposed in a state of covering, on the radially outer side, at least a portion of a connection position P1 where the proximal end 43 of the support body and the distal end 71 of the outer tube are connected.

Description

Image Acquisition Catheter

[0001] The present invention relates to an image acquisition catheter.

[0002] In the treatment of lesions such as stenoses and occlusions occurring in biological lumens such as blood vessels, an image acquisition catheter using intravascular ultrasound (IVUS) is used as a medical device for acquiring diagnostic images to observe the properties of these lesions or the condition after treatment (see, for example, Patent Document 1).

[0003] The image acquisition catheter of Patent Document 1 includes a sensor unit (film sensor) provided with a transducer (transducer array), a support that supports a flexible substrate, and a shaft portion having the flexible substrate and the support disposed at a distal end thereof. The flexible substrate is provided with signal lines for connection to a wiring unit for transmitting and receiving various electrical signals between the transducer array and an external device.

[0004] In the image acquisition catheter of Patent Document 1, the sensor unit is fixed to the support and thus held at a predetermined position. Further, the sensor unit is connected to an outer tube constituting the shaft portion via an intermediate member (connector).

[0005] WO2018 / 130449

[0006] In procedures using an image acquisition catheter, the image acquisition catheter may be moved along bent portions or meandering sites of a biological lumen. At this time, stress concentration occurs in the vicinity of the connection position between the sensor unit and the shaft portion due to the influence of the physical property step between the sensor unit and the shaft portion. Further, the shaft portion is generally formed of a relatively flexible material such as a resin material. Therefore, while the shaft portion deforms to follow the bent portion, the sensor unit does not deform sufficiently to follow the bent portion. As a result, when the image acquisition catheter passes through the bent portion, the shaft portion and the sensor unit move away from each other. This makes breakage likely to occur near the connection position between the sensor unit and the shaft portion.

[0007] The present invention has been made in response to the above-mentioned problems, and aims to provide an image acquisition catheter that can prevent breakage from occurring near the connection point where the support body of the sensor part and the outer tube are connected.

[0008] The present invention can be achieved by any one of the means described in (1) to (7) below.

[0009] (1) An image acquisition catheter comprising: an inner tube having a first lumen extending in the axial direction; a sensor section disposed at the tip of the inner tube, wherein a plurality of transducers for transmitting and receiving ultrasonic waves are arranged in a ring shape in the circumferential direction; and an outer tube disposed to cover at least a part of the inner tube so as to form a second lumen between itself and the inner tube, wherein the sensor section comprises a film sensor on which the plurality of transducers are arranged, and a support for supporting the film sensor, and the film sensor has a rib portion disposed to cover at least a part of the connection position where the base end of the support and the tip of the outer tube are connected, radially outward.

[0010] (2) The image acquisition catheter according to (1), having an adhesive portion provided between the rib portion and the base end of the support and / or between the rib portion and the tip of the outer tube.

[0011] (3) The image acquisition catheter according to (2), wherein the tip of the outer tube has a cut surface cut obliquely with respect to the axial direction, and the proximal end of the cut surface is located proximal to the proximal end of the support.

[0012] (4) The image acquisition catheter according to (3), wherein the adhesive portion is positioned to a position closer to the proximal end than the proximal end of the cut surface.

[0013] (5) The image acquisition catheter according to (4), wherein the base end of the film sensor is connected to a wiring section located in the second lumen, the base end of the film sensor extends further towards the base end than the base end of the adhesive section, and is located on the same side in the radial direction on the orthoaxial cross section as the base end of the cut surface.

[0014] (6) The image acquisition catheter according to (4) or (5), wherein the base end of the rib portion is positioned in substantially the same position as the base end of the support in the axial direction, and is located on the same side as the side on which the tip of the cut surface is located in the radial direction of the cross section perpendicular to the axis.

[0015] (7) An image acquisition catheter according to any one of (1) to (6), further comprising a connecting tube located radially outward from the proximal end and the tip of the outer tube of the film sensor.

[0016] The image acquisition catheter of the present invention can prevent breakage from occurring near the connection point where the support of the sensor part and the outer tube are connected.

[0017] This is a schematic diagram of a medical system including an image acquisition catheter according to an embodiment. This is a diagram showing the image acquisition catheter according to an embodiment. This is a cross-sectional view of the image acquisition catheter according to an embodiment. This is an enlarged cross-sectional view of the vicinity of the tip of the inner tube of the image acquisition catheter according to an embodiment. This is an enlarged cross-sectional view of the vicinity of the tip of the outer tube of the image acquisition catheter according to an embodiment. This is a perspective view for explaining the rib portion of the image acquisition catheter according to an embodiment. This is a cross-sectional view along the line 7A-7A shown in Figure 5. This is a cross-sectional view along the line 8A-8A shown in Figure 5. This is a cross-sectional view along the line 9A-9A shown in Figure 5. This is a diagram showing an image acquisition catheter according to a modified example.

[0018] Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. The embodiments shown herein are illustrative examples for embodying the technical idea of ​​the present invention and do not limit the present invention. Furthermore, all other implementable forms, examples, and operational techniques that can be conceived by those skilled in the art without departing from the spirit of the present invention are included in the scope and spirit of the present invention, as well as in the claims and their equivalents.

[0019] Furthermore, the drawings attached to this specification may be schematically represented with changes to scale, aspect ratio, shape, etc., from the actual object for the sake of illustration and ease of understanding, but these are merely examples and do not limit the interpretation of the present invention.

[0020] For the sake of clarity, the following directions are defined in this specification.

[0021] In each figure, the "axial direction" is the direction along the central axis c1 of the image acquisition catheter 100. The "circumferential direction" is the rotational direction with the central axis c1 of the image acquisition catheter 100 as the reference axis. The "radial direction" is the direction (radial direction) approaching or moving away from the central axis c1 on the cross-sectional area perpendicular to the axis shown in Figures 7 to 9.

[0022] Furthermore, the arrows X1-X2 in each figure indicate the axial direction of the image acquisition catheter 100, the arrows Y1-Y2 indicate the depth direction perpendicular to the axial direction, and the arrows Z1-Z2 indicate the height direction perpendicular to both the axial direction and the depth direction. The cross section perpendicular to the axial direction (Y1-Y2 / Z1-Z2 cross section) is defined as the orthoaxial cross section.

[0023] In the image acquisition catheter 100, the side where the proximal hub portion 95 is located is referred to as the "proximal end." The side of the image acquisition catheter 100 that is located opposite the proximal end and is introduced into the body is referred to as the "proximal end." Furthermore, "proximal end" refers to the portion that includes a certain range extending from the tip (frontmost point) towards the proximal end, and "proximal end" refers to the portion that includes a certain range extending from the proximal end (very proximal end) towards the proximal end.

[0024] Figures 1 and 2 are schematic diagrams showing the overall configuration of the medical system 1 and the image acquisition catheter 100 according to this embodiment. Figures 3 to 5 are diagrams showing cross-sections of various parts in the axial direction of the image acquisition catheter 100. Figure 6 is a simplified perspective view to explain the positional relationship between the rib portion 35a of the film sensor 30 and the cut surface 72 of the outer tube 70. Figures 7 to 9 are orthogonal cross-sectional views of the image acquisition catheter 100 at various positions shown in Figure 5.

[0025] In this embodiment, the image acquisition catheter 100 is configured as an IVUS catheter utilizing intravascular ultrasound diagnostics.

[0026] Examples of biological lumens to which the image acquisition catheter 100 can be applied include blood vessels. However, the biological lumens to which the image acquisition catheter 100 can be applied are not limited to blood vessels, but may also include other biological organs such as the bile duct, trachea, esophagus, other digestive tract organs, urethra, ear, nose, and throat lumen, etc.

[0027] <Medical System 1> As shown in Figure 1, the medical system 1 includes an image acquisition catheter 100 and an external device 300.

[0028] Medical system 1 is used to diagnose the characteristics of a lesion by inserting an image acquisition catheter 100 into the patient's blood vessel to deliver the sensor unit 20 to the lesion, and outputting images (such as cross-sectional images of blood vessels) taken at and around the lesion to an external device 300.

[0029] <Image Acquisition Catheter 100> Referring to Figures 1 to 5, the image acquisition catheter 100 comprises an inner tube 10 having a first lumen 15 extending in the axial direction, a sensor section 20 positioned at the tip 11 of the inner tube 10 with a plurality of transducers 37a for transmitting and receiving ultrasonic waves arranged in a ring shape in the circumferential direction, and an outer tube 70 positioned to cover at least a part of the inner tube 10 so as to form a second lumen 75 between itself and the inner tube 10.

[0030] The image acquisition catheter 100 is configured as a so-called "over-the-wire type catheter," in which a guidewire can be inserted and removed from the first port 95a of the proximal hub portion 95 through the first lumen 15 of the inner tube 10. However, the image acquisition catheter 100 may also be configured as a so-called "rapid exchange type catheter."

[0031] <Inner tube 10> As shown in Figure 3, the inner tube 10 can be made up of a long tubular member having a first lumen 15 that extends from the tip 11 to the base 13.

[0032] A guidewire can be inserted through the first lumen 15 to guide the movement of the imaging catheter 100 within the biological lumen.

[0033] As shown in Figure 4, the tip 11 of the inner tube 10 is provided with a tip opening 11a for inserting a guidewire into the first lumen 15. The proximal end 13 of the inner tube 10 is provided with a proximal end opening 13a for guiding the guidewire, which has been inserted into the first lumen 15, to the proximal end of the image acquisition catheter 100.

[0034] The constituent material of the inner tube 10 is a material that can be used in known catheters and the like, and 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 can be used.

[0035] As shown in Figures 3 and 4, a tip member 90 (tip) can be attached near the tip 11 of the inner tube 10. The tip member 90 can be made of, for example, a resin material with relatively high flexibility. The tip member 90 can be joined (fixed) to the support 40 of the sensor unit 20 by, for example, a joint 90a.

[0036] The tip member 90 can be configured to have a tapered portion whose outer diameter gradually decreases towards the tip. This improves the ease with which the image acquisition catheter 100 can be inserted into a biological lumen.

[0037] <Sensor Unit 20> As shown in Figures 3 to 5, the sensor unit 20 includes a film sensor 30 on which a plurality of transducers 37a are arranged, and a support 40 that supports the film sensor 30.

[0038] <Film Sensor 30> The film sensor 30 can be made of a flexible substrate on which electronic components are mounted on a film substrate. An electronic circuit including a plurality of transducers 37a, etc., is formed on the surface of the film sensor 30.

[0039] As shown in Figure 6, a cylindrical portion 35 is formed on a part of the film sensor 30 by winding a flat main body portion in the circumferential direction. The film sensor 30 is supported by a support 40 in the state in which the cylindrical portion 35 is formed.

[0040] The cylindrical portion 35 is arranged coaxially with the inner tube 10 and the outer tube 70 (on the same central axis c1). The cylindrical portion 35 can be configured, for example, to form a cylindrical shape having a substantially circular cross-section perpendicular to the axis.

[0041] The film sensor 30 includes an extension portion 36 extending from the cylindrical portion 35 toward the proximal end side. As shown in FIG. 6, the extension portion 36 extends from the proximal end of the cylindrical portion 35 to the proximal end side, and is arranged only on a part of the circumferential direction around the central axis c1. A part of the extension portion 36 and a proximal end portion 33 located closer to the proximal end side than the extension portion 36 can be arranged in the second lumen 75.

[0042] As shown in FIG. 5 and FIG. 6, the film sensor 30 has a rib portion 35a arranged to cover at least a part of the connection position P1 where the proximal end portion 43 of the support body 40 and the distal end portion 71 of the outer tube 70 are connected on the radially outer side.

[0043] The rib portion 35a can be constituted by a part of the cylindrical portion 35.

[0044] In the present embodiment, the rib portion 35a is located on the proximal end side of the proximal protrusion 44b of the support body 40 in the cylindrical portion 35, and is constituted by a portion that radially overlaps at least a part of the proximal end portion 43 of the support body 40 and the distal end portion 71 of the outer tube 70 (a part including the distal end 72a of the cut surface 72 described later).

[0045] As shown in FIG. 5, the image acquisition catheter 100 includes an adhesive portion 80 that connects the support body 40, the outer tube 70, and the inner tube 10.

[0046] The adhesive portion 80 is arranged in a peripheral area of the proximal end portion 43 of the support body 40 and the distal end portion 71 of the outer tube 70.

[0047] By providing the rib portion 35a, the image acquisition catheter 100 can exhibit the following effects.

[0048] In a procedure using the image acquisition catheter 100, when moving the vicinity of the distal end portion 71 of the outer tube 70 to a bent portion or the like of a biological lumen, fracture or the like is likely to occur in the vicinity of the connection position P1 between the support body 40 and the outer tube 70. This is because stress concentration easily occurs in the vicinity of the connection position P1 between the support body 40 and the outer tube 70, and this is also caused by the influence of a physical property step between the support body 40 formed of a relatively highly rigid material such as a metal material and the outer tube 70 formed of a relatively highly flexible material such as a resin material. As described above, the rib portion 35a is arranged so as to cover at least a part of the connection position P1 on the radially outer side. When the vicinity of the distal end portion 71 of the outer tube 70 passes through a bent portion or the like of a biological lumen, the rib portion 35a configured as described above restricts the movement of the distal end portion 71 of the outer tube 70 on the radially outer side, and suppresses excessive movement of the distal end portion 71 of the outer tube 70 in a direction separating from the support body 40. Therefore, the image acquisition catheter 100 can prevent the distal end portion 71 of the outer tube 70 from fracturing in the vicinity of the connection position P1.

[0049] Further, in the present embodiment, since the rib portion 35a is formed of a part of the film sensor 30, an increase in the number of parts can be prevented when providing the structure for preventing the above-mentioned fracture. Accordingly, the image acquisition catheter 100 can effectively prevent the occurrence of the aforementioned fracture without adding a specifically shaped member having a function like the rib portion 35a.

[0050] Further, in the present embodiment, the rib portion 35a is formed of the cylindrical portion 35 shaped into a cylindrical shape of the film sensor 30. Therefore, the rib portion 35a can be arranged so as to cover the connection position P1 over substantially the entire circumferential direction in the circumferential direction. Accordingly, the aforementioned movement of the distal end portion 71 of the outer tube 70 can be more effectively prevented, and the occurrence of the aforementioned fracture can be more reliably prevented.

[0051] There is no particular limitation on the range in which the rib portion 35a covers the connection position P1 (the range in which the rib portion 35a is arranged in the circumferential direction around the central axis c1 when viewed in an axial cross-sectional view perpendicular to the axis in FIG. 7). In addition, the cross-sectional shape of the rib portion 35a is not limited to a circular shape, as long as the effect of preventing the aforementioned fracture is exhibited by covering at least a part of the connection position P1 with the rib portion 35a.

[0052] As shown in Figure 7, the adhesive portion 80 can be provided between the rib portion 35a and the base end portion 43 of the support 40 and / or between the rib portion 35a and the tip portion 71 of the outer tube 70.

[0053] The phrase "between the rib portion 35a and the base end portion 43 of the support 40" refers to the portion (region) located between the inner surface of the rib portion 35a and the outer surface of the base end portion 43 of the support 40 in the cross-sectional area perpendicular to the axis shown in Figure 7. Similarly, the phrase "between the rib portion 35a and the tip portion 71 of the outer tube 70" refers to the region (region) located between the inner surface of the rib portion 35a and the outer surface of the tip portion 71 of the outer tube 70 in the cross-sectional area perpendicular to the axis shown in Figure 7.

[0054] By arranging the adhesive portion 80 as described above, the fixing force between the rib portion 35a, the base end portion 43 of the support 40, and the tip portion 71 of the outer tube 70 can be increased. This makes it possible to more effectively prevent breakage at the connection position P1. In particular, in this embodiment, since the adhesive portion 80 is arranged at both positions, between the rib portion 35a and the base end portion 43 of the support 40 and between the rib portion 35a and the tip portion 71 of the outer tube 70, the fixing force between each member 30, 40, and 70 can be effectively increased.

[0055] Each transducer 37a arranged on the film sensor 30 is equipped with a transducer made of a piezoelectric material having piezoelectric properties, such as ceramics or quartz, which can convert electrical signals into ultrasonic vibrations. The transducers 37a form a phased array, arranged in a ring shape along the circumferential direction of the support 40, with a portion of the film sensor 30 wound around the support 40. By equipping the image acquisition catheter 100 with a phased array type sensor configured as described above, tomographic images of blood vessels can be acquired simultaneously over a wide area in the circumferential direction without rotating the sensor unit 20. There are no particular restrictions on the type, arrangement, or number of transducers 37a.

[0056] Multiple transducers 37a have the function of transmitting ultrasound based on electrical signals (pulse signals) into a biological lumen and receiving ultrasound reflected from biological tissue within the biological lumen. Each transducer 37a is positioned on the surface of the film sensor 30 and is connected to the multiplexer 37b.

[0057] The multiplexer 37b is a combination circuit that selects one of several input lines and connects it to a single output line. Each transducer 37a is connected to each of the multiple signal lines 37d formed on the film sensor 30 via the multiplexer 37b. Each transducer 37a is configured to sequentially switch between transmit and receive operations by the multiplexer 37b. In other words, the multiple transducers 37a sequentially receive each received signal and sequentially transmit the received signals via the multiplexer 37b. The multiplexer 37b is driven and controlled by a control IC 37c formed on the film sensor 30.

[0058] The signal line 37d formed on the film sensor 30 extends to the vicinity of the base end 33 of the film sensor 30.

[0059] The image acquisition catheter 100 is connected to the film sensor 30 and has a wiring section 50 that enables the transmission of electrical signals between multiple transducers 37a and an external device 300.

[0060] The base end 33 of the film sensor 30 can be connected to the tip 51 of the wiring section 50 by soldering or the like while the signal line 37d and the conductor portion of the wiring section 50 (not shown) are electrically connected.

[0061] The sensor unit 20 can send and receive various signals to and from the control unit 310 of the external device 300 via the signal line 37d and the wiring unit 50.

[0062] The film sensor 30 can be made of, for example, a material such as polyimide processed into a sheet.

[0063] <Support 40> As shown in Figures 4 and 5, the support 40 has a tip portion 41, a base portion 43, a shaft portion 44 extending between the tip portion 41 and the base portion 43, a lumen 45 that connects the tip portion 41 and the base portion 43 and through which the inner tube 10 is inserted, a tip-side projection 44a provided near the tip of the shaft portion 44 and projecting in a direction perpendicular to the axial direction, and a base-side projection 44b provided near the base of the shaft portion 44 and projecting in a direction perpendicular to the axial direction.

[0064] As shown in Figure 4, the tip member 90 can be fixed to the tip portion 41 of the support 40. There are no particular restrictions on the specific position or range for fixing the tip member 90 to the support 40, but for example, any location near the tip portion 41 and the tip-side protrusion 44a can be selected.

[0065] As shown in Figures 4 and 5, the film sensor 30 is wrapped around the outer circumferential surface of the tip-side projection 44a and the outer circumferential surface of the base-side projection 44b. The tip portion 31 of the film sensor 30 is joined to the tip member 90 by a joining portion 90a.

[0066] A filler material 46 is filled in the space partitioned between the film sensor 30 and the shaft portion 44. The filler material 46 can be made of, for example, a resin component obtained by curing a resin bonding material (adhesive, etc.). The bonding force between the film sensor 30 and the support 40 is increased via the filler material 46.

[0067] The support 40 can be made of a metal material, either partially or entirely. Examples of metal materials include SUS (stainless steel). Alternatively, the support 40 can be made of a resin tube coated with a metal such as gold. Furthermore, the support 40 can be made of a material that is harder (more rigid) than the film sensor 30, the inner tube 10, and the outer tube 70. This allows the support 40 to firmly support the film sensor 30.

[0068] In the image acquisition catheter 100, the filler 46, adhesive portion 80, and joint portion 90a used for joining members and reinforcing joint strength can each be made of, for example, a resin-based adhesive. As the resin-based adhesive, for example, one that is fluid when applied and hardens through a chemical change based on a curing treatment after application can be used. Examples of such materials include UV-curing adhesives and thermosetting adhesives (epoxy adhesives, etc.).

[0069] <Outer tube 70> The outer tube 70 is positioned to form a second lumen 75 between itself and the inner tube 10.

[0070] The outer tube 70 is arranged coaxially with the inner tube 10. The outer tube 70 can be made of the same material as the material exemplified above for the inner tube 10.

[0071] As shown in Figures 5 and 6, the tip portion 71 of the outer tube 70 has a cut surface 72 that is cut at an angle with respect to the axial direction.

[0072] The cut surface 72 has a tip 72a located at the tip end of the tip opening 71a and a base end 72b located at the base end of the tip opening 71a.

[0073] As shown in Figure 6, the cut surface 72 has an inclined shape that extends toward the tip. Therefore, on the cross-sectional area perpendicular to the axis in Figures 7 and 8, the cross-sectional area of ​​the tube wall portion (the region arranged in the circumferential direction around the central axis c1) of the outer tube 70 gradually increases from the tip portion 71 to the base portion 73 of the outer tube 70.

[0074] As shown in Figures 5, 6, and 9, the portion of the outer tube 70 that extends beyond the cut surface 72 toward the base end can be configured to have a substantially circular cross-section.

[0075] As shown in Figures 5, 6, and 7, at connection position P1, the tip 72a of the cut surface 72 of the outer tube 70 and its surrounding area are covered by the rib portion 35a of the film sensor 30.

[0076] As shown in Figures 5 and 6, the base end 72b of the cut surface 72 is located on the base side of the base end 43 of the support 40. Therefore, the base end 72b of the cut surface 72 does not overlap with the rib portion 35a and the support 40 in the circumferential direction.

[0077] As described above, since the base end 72b of the cut surface 72 is located on the base end side of the base end 43 of the support 40, the extended portion 36 extending from the cylindrical portion 35 of the film sensor 30 toward the base end can be easily drawn into the second lumen 75 through the tip opening 71a from the base end 72b side of the cut surface 72 (the side opposite to the portion located at the tip 72a when viewed in a cross section perpendicular to the axis). This makes it easy to connect the base end 33 located on the base end side of the extended portion 36 with the tip end 51 of the wiring portion 50.

[0078] As shown in Figure 5, the adhesive portion 80 can be positioned further towards the base end than the base end 72b of the cut surface 72.

[0079] As described above, by arranging the adhesive portion 80, the cut surface 72 is fixed to the support 40 and / or inner tube 10 over the entire axial range from the tip 72a to the base 72b. Therefore, the fixing force between each member 30, 40, and 70 near the tip 71 of the outer tube 70 can be further improved.

[0080] As mentioned above, the base end 33 of the film sensor 30 is connected to the wiring section 50 located in the second lumen 75 (see Figure 5).

[0081] As shown in Figure 5, the base end portion 33 of the film sensor 30 extends further towards the base end than the base end of the adhesive portion 80, and is located on the same side (arrow Z1 side) as the base end 72b of the cut surface 72 of the outer tube 70 in the radial direction on the cross section perpendicular to the axis.

[0082] The base end 33 of the film sensor 30 is connected to the tip 51 of the wiring section 50, which is inserted into the second lumen 75, at the base end 72b side of the cut surface 72 of the outer tube 70. Furthermore, the position where the base end 33 of the film sensor 30 is located is on the opposite side of the radial direction from where the rib section 35a is located. Therefore, the image acquisition catheter 100 can prevent breakage at the connection position P1 by covering the tip 72a located radially on the rib section 35a side with the rib section 35a of the film sensor 30, while easily connecting the wiring section 50 to the base end 33 inserted into the second lumen 75 from the base end 72b side.

[0083] As shown in Figures 5 and 6, the base end of the rib portion 35a is positioned in approximately the same location as the base end of the support 40 in the axial direction, and is located on the same side (arrow Z2 side) as the tip 72a of the cut surface 72 in the radial direction on the cross section perpendicular to the axis.

[0084] As described above, by not positioning the rib portion 35a beyond the base end of the support 40, the following regions are formed near the connection position P1, in order from the tip side toward the base end: a region where the rib portion 35a, the support 40, the tip 72a of the cut surface 72 of the outer tube 70, and the inner tube 10 overlap in the circumferential direction (the region shown in Figure 7); a region where the extended portion 36 of the film sensor 30, the cut surface 72 of the outer tube 70, and the inner tube 10 overlap in the circumferential direction (the region shown in Figure 8); and a region where the base end portion 33 of the film sensor 30, the tip portion 51 of the wiring portion 50, the outer tube 70, and the inner tube 10 overlap in the circumferential direction (the region shown in Figure 9).

[0085] Comparing the above regions, the region where the rib portion 35a is located (the region shown in Figure 7) has greater rigidity due to the presence of the rib portion 35a than the region located closer to the proximal end (the region shown in Figure 8). Therefore, at connection position P1, the rigidity gradually decreases from the region where the rib portion 35a is located toward the proximal end region (for example, the region where the proximal end portion 33 of the film sensor 30 and the tip portion 51 of the wiring portion 50 are connected). This allows for a gradual reduction of the difference in physical properties from the position where the support 40 and the rib portion 35a are located toward the proximal end. As a result, when the image acquisition catheter 100 passes through a bend in a biological lumen, its ability to follow the bend is improved over the range from connection position P1 toward its proximal end. Consequently, fracture near connection position P1 can be prevented more effectively.

[0086] There are no particular restrictions on the axial length of the cut surface 72 formed on the outer tube 70, the inclination angle of the cut surface 72 (the angle of inclination with respect to the central axis c1), etc.

[0087] As shown in Figure 3, the base end 73 of the outer tube 70 is positioned towards the tip of the second port 95b of the hand hub portion 95. The base end opening 73a of the outer tube 70 is positioned to communicate with the second port 95b. The wiring portion 50 connected to the film sensor 30 is inserted through the second lumen 75 and then led out from the second port 95b.

[0088] As shown in Figure 3, the image acquisition catheter 100 may have a radiopaque marker 18 arranged on the outer circumference of the inner tube 10.

[0089] The radiopaque marker 18 can be composed of, for example, radiopaque members arranged at regular intervals along the axial direction of the inner tube 10.

[0090] The radiopaque marker 18 can be configured, for example, as a coil-type radiopaque marker wound in a sparse and dense manner along the outer surface of the inner tube 10. By configuring the radiopaque marker 18 in this way, the space occupied by the radiopaque marker 18 in the second lumen 75 can be reduced. The radiopaque marker 18 can also be configured, for example, as a ring-shaped member fixed to the outer surface of the inner tube 10 by swaging.

[0091] The radiopaque member can be made of, for example, a known metallic material that is radiopaque. Examples of metallic materials that can be used as the radiopaque marker 18 include Pt, Pt alloys, W, W alloys, Ag, Ag alloys, etc. The cross-sectional shape of the radiopaque member is, for example, circular or rectangular, but is not limited to these.

[0092] <Hand hub section 95> The hand hub section 95 has a first port 95a and a second port 95b. The hand hub section 95 is connected to the base end 13 of the inner pipe 10 and the base end 73 of the outer pipe 70.

[0093] The handle hub section 95 is connected to the base end opening of the first port 95a and the first lumen 15 of the inner tube 10 in communication. This allows the handle hub section 95 to insert and remove the guide wire from the inner tube 10.

[0094] The hand-held hub section 95 is connected to the base end opening of the second port 95b and the second lumen 75 of the outer tube 70 in communication. This allows the hand-held hub section 95 to lead out the wiring section 50 from the second port 95b.

[0095] The hand-held hub portion 95 can be made of, for example, a hard resin or metal material applicable in the medical field.

[0096] <External device 300> As shown in Figure 1, the external device 300 includes a control unit 310 and a display device 320.

[0097] The image acquisition catheter 100 can be connected to the conversion module device 130 via the cable 120. The conversion module device 130 controls the output of ultrasound transmitted from the transducer 37a of the film sensor 30, and controls the electrical signals transmitted and received between the transducer 37a and the control unit 310.

[0098] The external device 300 is electrically connected to the image acquisition catheter 100 by being connected to the image acquisition catheter 100 and the conversion module device 130 via a cable 140. This enables the external device 300 to send and receive electrical signals with the sensor unit 20 of the image acquisition catheter 100.

[0099] The control unit 310 mainly consists of a CPU, memory, and input / output unit, and is responsible for controlling the entire medical system 1. The control unit 310 outputs a control signal to cause the sensor unit 20 of the image acquisition catheter 100 to transmit ultrasound, receives a detection signal from the sensor unit 20, and performs predetermined signal processing based on the detection signal to acquire image data (tomographic image).

[0100] The control unit 310 displays information (video) based on the acquired image data on the display device 320.

[0101] As described above, the image acquisition catheter 100 according to this embodiment comprises an inner tube 10 having a first lumen 15 extending in the axial direction, a sensor unit 20 positioned at the tip 11 of the inner tube 10 and having a plurality of transducers 37a for transmitting and receiving ultrasonic waves arranged in a ring shape in the circumferential direction, and an outer tube 70 positioned to cover at least a part of the inner tube 10 so as to form a second lumen 75 between itself and the inner tube 10. The sensor unit 20 has a film sensor 30 on which a plurality of transducers 37a are arranged, and a support 40 that supports the film sensor 30. The film sensor 30 has a rib portion 35a positioned to cover at least a part of the connection position P1 where the base end 43 of the support 40 and the tip 71 of the outer tube 70 are connected, radially outward.

[0102] The image acquisition catheter 100 configured as described above has a rib portion 35a that is positioned to cover at least a part of the connection position P1 radially outward. As the tip portion 71 of the outer tube 70 passes through a bend in the biological lumen, the movement of the tip portion 71 of the outer tube 70 is restricted radially outward, preventing the tip portion 71 of the outer tube 70 from moving excessively away from the support 40. Therefore, the image acquisition catheter 100 can prevent the tip portion 71 of the outer tube 70 from breaking near the connection position P1.

[0103] Furthermore, since the rib portion 35a of the image acquisition catheter 100 is made up of a part of the film sensor 30, it is possible to prevent an increase in the number of parts when providing the structure to prevent the above-mentioned breakage. As a result, the image acquisition catheter 100 can effectively prevent the occurrence of the above-mentioned breakage without adding any specific shaped members with functions such as the rib portion 35a.

[0104] <Example of modification> As shown in the example of modification in Figure 10, the image acquisition catheter may further have a connecting tube 60A located radially outside the proximal end 33 of the film sensor 30 and the tip 71 of the outer tube 70.

[0105] The connecting tube 60A (second outer tube) can be positioned radially outward from the base end 33 of the film sensor 30, the base end 43 of the support 40, and the tip 71 of the outer tube 70. Furthermore, each of the above components 30, 40, and 70 can be integrally joined together with the shrink tube by means of heating, fusion, or other means. In this case, the tip position of the shrink tube is set to a position that does not cover the ultrasonic transducer mounted on the film sensor 30. This prevents the transducer from being covered or attenuated by the shrink tube or adhesive, and suppresses a decrease in sensor performance. In addition, by interposing adhesive parts 80 inside each part covered by the connecting tube 60A, each component such as the inner tube 10, outer tube 70, connecting tube 60A, and support 40 can be fixed in a desired positional relationship.

[0106] Although the image acquisition catheter according to the present invention has been described above through embodiments and modifications, the present invention is not limited to the configuration described in the embodiments, and can be modified as appropriate based on the claims.

[0107] For example, the outer tube 70 is not limited to having a cut surface 72. The outer tube 70 may be composed of a tubular member having an open end at which the tip opening 71a is substantially circular in a cross-section perpendicular to the axis.

[0108] This application is based on Japanese Patent Application No. 2025-049298, filed on 25 March 2025, the disclosures of which are incorporated herein by reference in their entirety.

[0109] 1 Medical System 10 Inner tube 11 Tip of inner tube 13 Base of inner tube 15 First lumen 18 Radiopaque marker 20 Sensor section 30 Film sensor 31 Tip of film sensor 33 Base of film sensor 35 Cylindrical section 35a Rib section 36 Extended section 37a Transducer 37b Multiplexer 37d Signal line 40 Support 41 Tip of support 43 Base of support 45 Lumen of support 46 Filling material 50 Wiring section 51 Tip of wiring section 70 Outer tube 71 Tip of outer tube 71a Opening at the tip of outer tube 72 Cut surface 72a Tip of cut surface 72b Base of cut surface 73 Base of outer tube 75 Second lumen 80 Adhesive section 90 Tip member 95 Proximal hub section 100 Image acquisition catheter 300 External device P1 Connection position c1 Central axis

Claims

1. An imaging catheter comprising: an inner tube having a first lumen extending in the axial direction; a sensor section disposed at the tip of the inner tube, wherein a plurality of transducers for transmitting and receiving ultrasonic waves are arranged in a ring shape in the circumferential direction; and an outer tube disposed to cover at least a portion of the inner tube so as to form a second lumen between itself and the inner tube, wherein the sensor section comprises a film sensor on which the plurality of transducers are arranged, and a support for supporting the film sensor, and the film sensor has a rib portion disposed to cover at least a portion of the connection position where the base end of the support and the tip end of the outer tube are connected, radially outward.

2. The image acquisition catheter according to claim 1, further comprising an adhesive portion provided between the rib portion and the proximal end of the support and / or between the rib portion and the tip of the outer tube.

3. The image acquisition catheter according to claim 2, wherein the tip of the outer tube has a cut surface cut obliquely with respect to the axial direction, and the proximal end of the cut surface is located proximal to the proximal end of the support.

4. The image acquisition catheter according to claim 3, wherein the adhesive portion is positioned to a position closer to the proximal end than the proximal end of the cut surface.

5. The image acquisition catheter according to claim 4, wherein the base end of the film sensor is connected to a wiring portion located in the second lumen, the base end of the film sensor extends further towards the base end than the base end of the adhesive portion, and is located on the same side as the base end of the cut surface in the radial direction on the orthoaxial cross-section.

6. The image acquisition catheter according to claim 4 or 5, wherein the base end of the rib portion is positioned substantially in the same position as the base end of the support in the axial direction, and is located on the same side as the side on which the tip of the cut surface is located in the radial direction of the cross section perpendicular to the axis.

7. The image acquisition catheter according to any one of claims 1 to 6, further comprising a connecting tube located radially outward from the proximal end and the tip of the outer tube of the film sensor.

Images