Method for manufacturing image acquisition catheter and image acquisition catheter

Abstract

[Problem] To provide a method for manufacturing an image acquisition catheter in which even a high-viscosity adhesive can be used, and in which the adhesive can easily be disposed. [Solution] This method for manufacturing an image acquisition catheter 100 includes: a step of applying an adhesive 56 to a film sensor 40; a step of aligning, with respect to a shaft part 54 of a support body 50, the region of the film sensor to which the adhesive has been applied; and a step of winding the film sensor around the support body in a state in which the adhesive, among the film sensor and the adhesive, is disposed facing the shaft part of the support body.

Description

Method for manufacturing a catheter for image acquisition and a catheter for image acquisition

[0001] The present invention relates to a method for manufacturing a catheter for image acquisition and a catheter for image acquisition.

[0002] In the treatment of lesions such as stenosis or occlusion occurring in a living body lumen such as a blood vessel, an intravascular imaging device (catheter for image acquisition) using an intravascular ultrasound diagnostic method (IVUS: Intravascular Ultrasound) is used as a medical device for acquiring a diagnostic image in order to observe these properties or the state after treatment (see Patent Document 1).

[0003] Patent Document 1 discloses a method for assembling a catheter for image acquisition. Specifically, as a method for assembling a catheter for image acquisition, a step of obtaining a support member (support body) having a main body portion including a plurality of recesses (holes) spaced apart in the axial direction, and a step of positioning a flexible circuit (film sensor) around the support member so that the flexible circuit is radially spaced apart from the main body portion of the support member, and a step of filling the space between the flexible circuit and the support member with a backing material (adhesive) through the plurality of recesses of the main body portion are disclosed.

[0004] Japanese Translation of PCT International Publication No. 2019-509855

[0005] In the assembly method described in Patent Document 1, the space between the flexible circuit and the support member is filled with a backing material through a plurality of recesses (holes) in the main body portion. In this method, there are problems such as the size of the recesses (holes) being small, so that only a low-viscosity adhesive can be used, or the difficulty of injection is high and the adhesive cannot be easily arranged.

[0006] The present invention has been made based on the above problems, and an object thereof is to provide a method for manufacturing a catheter for image acquisition and a catheter for image acquisition that can use a high-viscosity adhesive and can easily arrange the adhesive.

[0007] The present invention can be achieved by means according to any one of the following (1) to (4).

[0008] (1) An image acquisition catheter for acquiring diagnostic ultrasound tomographic images in a biological lumen, comprising: an inner tube having a first lumen extending in the axial direction; a sensor portion disposed at the tip of the inner tube, wherein a plurality of transducers for transmitting and receiving ultrasound waves in the biological lumen are arranged in a ring shape in the circumferential direction; and an outer tube disposed at a position closer to the proximal end than the sensor portion so as to cover at least a part of the inner tube, forming a second lumen between the inner tube and the outer tube, wherein the sensor portion comprises: a film sensor on which the plurality of transducers are arranged; and a support having a pair of axially spaced enlarged portions and a shaft portion located between the pair of enlarged portions, and supporting the film sensor, the method for manufacturing an image acquisition catheter for acquiring diagnostic ultrasound tomographic images in a biological lumen, comprising: a step of applying an adhesive to the film sensor; a step of aligning the area of ​​the film sensor on which the adhesive has been applied with respect to the shaft portion of the support; and a step of winding the film sensor around the support with respect to the film sensor, wherein the adhesive is positioned toward the shaft portion of the support.

[0009] (2) The method for manufacturing an image acquisition catheter according to (1), wherein the film sensor is wrapped around the support by bringing a pair of spaced-apart molds into close proximity.

[0010] (3) The method for manufacturing an image acquisition catheter according to (2), further comprising the step of winding the film sensor around the support, and then heating the adhesive in the pair of molds to cure it.

[0011] (4) An image acquisition catheter for acquiring diagnostic ultrasound tomographic images in a biological lumen, comprising: an inner tube having a first lumen extending in the axial direction; a sensor portion disposed at the tip of the inner tube, wherein a plurality of transducers for transmitting and receiving ultrasound in the biological lumen are arranged in a ring shape in the circumferential direction; and an outer tube disposed at a position closer to the proximal end than the sensor portion so as to cover at least a portion of the inner tube, forming a second lumen between the outer tube and the inner tube, wherein the sensor portion comprises: a film sensor on which the plurality of transducers are arranged; and a support for supporting the film sensor, comprising a pair of axially spaced enlarged portions and a shaft portion located between the pair of enlarged portions, wherein the enlarged portions and the shaft portion are closed, the image acquisition catheter.

[0012] The present invention provides a method for manufacturing an image acquisition catheter, which includes a step of winding the film sensor around a support with the adhesive (of which the film sensor and adhesive are located) positioned towards the axial portion of the support. That is, by winding the film sensor coated with adhesive around the support, the adhesive can be positioned between the film sensor and the support. Therefore, a method for manufacturing an image acquisition catheter can be provided that allows the use of high-viscosity adhesives and facilitates the positioning of the adhesive.

[0013] This is a schematic diagram of a medical system including an image acquisition catheter according to an embodiment. This is a diagram showing an image acquisition catheter according to an embodiment. This is a cross-sectional view of an image acquisition catheter according to an embodiment. This is a perspective view of a support according to an embodiment. This is a cross-sectional view of a support 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 an enlarged cross-sectional view of a part of the image acquisition catheter according to an embodiment. This is a schematic diagram showing the coating step of the manufacturing method of an image acquisition catheter according to an embodiment. This is a schematic diagram showing the arrangement step of the manufacturing method of an image acquisition catheter according to an embodiment. This is a schematic diagram showing the state during the winding step of the manufacturing method of an image acquisition catheter according to an embodiment. This is a schematic diagram showing the state when the winding step of the manufacturing method of an image acquisition catheter according to an embodiment is completed.

[0014] 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.

[0015] 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.

[0016] For the sake of clarity, the following directions are defined in this specification. In each figure, the "axial direction" is the direction along the central axis c1 of the image acquisition catheter 100 (see Figure 6). The "circumferential direction" is the rotational direction with the central axis c1 of the image acquisition catheter 100 as the reference axis.

[0017] 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 also referred to as the orthoaxial cross section.

[0018] In the image acquisition catheter 100, the side where the proximal hub portion 90 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 (extent) 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.

[0019] In this embodiment, the image acquisition catheter 100 is configured as an IVUS catheter utilizing intravascular ultrasound (IVUS).

[0020] In this embodiment, blood vessels are given as an example of a biological lumen to which the image acquisition catheter 100 is applied. However, the biological lumen to which the image acquisition catheter 100 is applied is not limited to blood vessels, and may also be other biological organs such as the bile duct, trachea, esophagus, other digestive tract organs, urethra, ear, nose, and throat lumen, etc.

[0021] <Medical System 1> As shown in Figure 1, the medical system 1 includes an image acquisition catheter 100 and an external device 300.

[0022] Medical system 1 is used to diagnose the characteristics of a lesion by inserting an image acquisition catheter 100 into the patient's blood vessels, delivering the sensor unit 30 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.

[0023] <Image Acquisition Catheter 100> Referring to Figures 1 to 8, the image acquisition catheter 100 comprises an inner tube 10 having a first lumen 15 extending in the axial direction, a sensor section 30 positioned at the tip 11 of the inner tube 10 and having a plurality of transducers 45a arranged in a ring shape in the circumferential direction for transmitting and receiving ultrasound within the biological lumen, and an outer tube 20 positioned on the proximal end side of the sensor section 30 and covering at least a part of the inner tube 10 so as to form a second lumen 25 between itself and the inner tube 10.

[0024] 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 91 of the proximal hub section 90 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."

[0025] <Inner tube 10> The inner tube 10 is a long tubular member having a first lumen 15 that extends from the tip 11 to the base 13.

[0026] A guidewire can be inserted through the first lumen 15 to guide the movement of the imaging catheter 100 within the biological lumen. The inner diameter, outer diameter, and wall thickness of the inner tube 10 can be configured to be approximately constant along the axial direction.

[0027] 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.

[0028] The constituent material of the inner tube 10 is a material applicable to 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.

[0029] As shown in Figures 2 and 3, a tip member 80 (tip) can be attached near the tip 11 of the inner tube 10. The tip member 80 can be made of, for example, a resin material with relatively high flexibility. The tip member 80 can be joined (fixed) to the support 50 of the sensor unit 30 by, for example, a joint 85.

[0030] The tip member 80 can be configured to have a tapered portion 81 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.

[0031] <Sensor Unit 30> As shown in Figures 3 to 8, the sensor unit 30 includes a film sensor 40 on which a plurality of transducers 45a are arranged, and a support 50 that supports the film sensor 40.

[0032] The film sensor 40 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 45a, etc., is formed on the surface of the film sensor 40. The film sensor 40 is held in a state where it is wound around the first enlarged diameter portion 51 and the second enlarged diameter portion 53 of the support 50.

[0033] Each transducer 45a 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 45a form a phased array in which the film sensor 40 is wound around the support 50 and arranged in a ring shape along the circumferential direction of the support 50. By using the phased array type sensor configured as described above, the sensor unit 30 can acquire tomographic images of blood vessels over a wide area in the circumferential direction all at once without rotating the sensor unit 30. There are no particular restrictions on the type, arrangement, or number of transducers 45a.

[0034] Multiple transducers 45a 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 45a is positioned on the surface of the film sensor 40 and is connected to the multiplexer 45b.

[0035] The multiplexer 45b is a combination circuit that selects one of several input lines and connects it to a single output line. Each transducer 45a is connected to each of the multiple signal lines 45d formed on the film sensor 40 via the multiplexer 45b. Each transducer 45a is configured so that the transmit and receive operations can be sequentially switched by the multiplexer 45b. In other words, the multiple transducers 45a sequentially receive each received signal and sequentially transmit the received signals via the multiplexer 45b. The multiplexer 45b is driven and controlled by a control IC 45c formed on the film sensor 40.

[0036] The signal line 45d formed on the film sensor 40 extends to the vicinity of the base end 43 of the film sensor 40. A wiring section 60 is connected to the film sensor 40. The sensor section 30 can send and receive various signals to and from the control unit 310 of the external device 300 via the signal line 45d and the wiring section 60.

[0037] <Support 50> As shown in Figures 4 to 7, the support 50 has a first enlarged diameter portion (corresponding to an enlarged diameter portion) 51 provided at the tip, a second enlarged diameter portion (corresponding to an enlarged diameter portion) 53 provided at the base end, a shaft portion 54 extending between the first enlarged diameter portion 51 and the second enlarged diameter portion 53, and a lumen 55 that connects the first enlarged diameter portion 51 and the second enlarged diameter portion 53 and through which the inner tube 10 is inserted.

[0038] The first enlarged diameter portion 51 has a straight portion 51a having a substantially constant outer diameter along the axial direction, and a tapered portion 51b located closer to the tip than the straight portion 51a, with its outer diameter gradually decreasing toward the tip in the axial direction.

[0039] As shown in FIG. 6, the tip member 80 can be fixed to the first enlarged diameter portion 51 of the support 50. There are no particular restrictions on the specific position or range for fixing the tip member 80 to the first enlarged diameter portion 51. For example, any position on the tip surface of the support 50 can be selected.

[0040] As shown in FIG. 6, the tip portion 41 of the film sensor 40 is wound around the outer peripheral surface of the straight portion 51a of the first enlarged diameter portion 51 of the support 50. The tip portion 41 of the film sensor 40 can be joined to the tip member 80 by the reinforcing material 72.

[0041] The second enlarged diameter portion 53 has a straight portion 53a having a substantially constant outer diameter along the axial direction, and a tapered portion 53b that is located on the base end side of the straight portion 53a and has a gradually decreasing outer diameter toward the base end side in the axial direction.

[0042] As shown in FIG. 7, a part of the film sensor 40 is wound around the outer peripheral surface of the straight portion 53a of the second enlarged diameter portion 53 of the support 50.

[0043] The shaft portion 54 of the support 50 has an outer diameter smaller than that of the straight portion 51a of the first enlarged diameter portion 51 and the straight portion 53a of the second enlarged diameter portion 53. As shown in FIGS. 6 and 7, in a state where the film sensor 40 is wound around the support 50, a holding space 54a for holding the adhesive 56 is defined between the film sensor 40 and the shaft portion 54. The adhesive 56 can be, for example, a curable resin member. The film sensor 40 has an increased bonding force with the support 50 via the adhesive 56. A method of disposing the adhesive 56 between the film sensor 40 and the shaft portion 54 will be described later.

[0044] As shown in FIGS. 6 and 7, no communication holes that communicate the inside and outside are formed in the inner peripheral surface 51c of the first enlarged diameter portion 51 and the inner peripheral surface 53c of the second enlarged diameter portion 53, and they are configured to be closed. Also, no communication holes that communicate the inside and outside are formed in the outer peripheral surface of the shaft portion 54, and it is configured to be closed.

[0045] The support 50 can be made of a metal material in part or entirely, for example. For example, the support 50 may have two straight sections 51a, 53a and a shaft section 54 integrally made of a metal material, and two tapered sections 51b, 53b made of a resin material.

[0046] As shown in Figure 7, at least a portion of the film sensor 40 is sandwiched between the support 50 and the outer tube 20. Therefore, at least a portion of the film sensor 40 is held between the support 50 and the outer tube 20. This increases the bonding strength between the outer tube 20, the film sensor 40, and the support 50.

[0047] In procedures using the image acquisition catheter 100, when moving the tip 21 of the outer tube 20 to a bent portion of the biological lumen, fractures and other damage are likely to occur near the joint between the support 50 and the outer tube 20. This is because stress concentration is likely to occur near the joint between the support 50 and the outer tube 20, and because of the difference in physical properties between the support 50, which is made of a relatively rigid material such as metal, and the outer tube 20, which is made of a relatively flexible material such as resin. In this embodiment, as described above, the joint strength between each component is increased by sandwiching at least a part of the film sensor 40 between the support 50 and the outer tube 20. Therefore, compared to the case where these components are joined only with a reinforcing material (e.g., adhesive), it is possible to effectively prevent fractures and other damage near the joint.

[0048] As described above, the second enlarged diameter portion 53 of the support 50 has a tapered portion 53b whose outer diameter gradually decreases toward the proximal end side in the axial direction (see FIG. 5). As shown in FIG. 7, the distal end portion 21 of the outer tube 20 is fitted to the support 50 in a state where at least a part of the film sensor 40 is sandwiched between the distal end portion 21 and the tapered portion 53b of the support 50. Therefore, at least a part of the film sensor 40 is more firmly joined to the support 50 by the distal end portion 21 of the outer tube 20 fitted to the tapered portion 53b of the support 50. Further, since the tapered portion 53b of the second enlarged diameter portion 53 of the support 50 has a shape in which the outer diameter gradually decreases toward the proximal end side, the outer tube 20 can be smoothly fitted to the tapered portion 53b by pushing the distal end portion 21 of the outer tube 20 along the tapered portion 53b.

[0049] As shown in FIG. 7, the distal end portion 21 of the outer tube 20 has a tapered shape in which the outer diameter increases toward the distal end side corresponding to the tapered portion 53b of the second enlarged diameter portion 53 of the support 50. As will be described later, the outer tube 20 can be made of, for example, a resin material. Therefore, when the outer tube 20 is pushed from the proximal end side toward the distal end side along the tapered portion 53b so as to sandwich at least a part of the film sensor 40 between the tapered portion 53b of the second enlarged diameter portion 53 of the support 50, the distal end portion 21 of the outer tube 20 expands so as to increase the diameter toward the distal end side corresponding to the shape of the tapered portion 53b. By sandwiching at least a part of the film sensor 40 between the tapered portion 53b of the second enlarged diameter portion 53 of the support 50 and the distal end portion 21 of the outer tube 20 whose outer diameter increases toward the distal end side, it is possible to more effectively increase the joining strength of the outer tube 20, the film sensor 40, and the support 50.

[0050] The image acquisition catheter 100 is connected to the film sensor 40 and has a wiring portion 60 (see FIG. 8) that enables transmission of an electrical signal between the plurality of transducers 45a and the external device 300. As shown in FIG. 7, the proximal end portion 43 of the film sensor 40 is disposed on the proximal end side of the position sandwiched between the support 50 and the outer tube 20. The distal end portion 61 of the wiring portion 60 is connected to the proximal end portion 43 of the film sensor 40.

[0051] The base end 43 of the film sensor 40 can be connected to the tip 61 of the wiring section 60 by soldering or the like, while the signal line 45d provided on the film sensor 40 and the conductor portion of the wiring section 60 are electrically connected.

[0052] As mentioned above, in procedures using the image acquisition catheter 100, when moving the tip 21 of the outer tube 20 to a bent portion of the biological lumen, stress concentration tends to occur near the joint between the outer tube 20 and the support 50. Therefore, if the connection between the film sensor 40 and the wiring section 60 is placed at such a joint, there is a risk of the film sensor 40 breaking or the wiring section 60 breaking. To address this problem, the image acquisition catheter 100 positions the proximal end 43 of the film sensor 40, which is connected to the wiring section 60, at a predetermined distance towards the proximal end from the position where the film sensor 40 is sandwiched between the support 50 and the outer tube 20 (the clamped position). Therefore, it is possible to effectively prevent the film sensor 40 from breaking or the wiring section 60 from breaking near the connection between the film sensor 40 and the wiring section 60.

[0053] There are no particular restrictions on the specific position where the connection between the base end 43 of the film sensor 40 and the tip 61 of the wiring section 60 is located, but for example, it can be set at a position 0.1 mm to 10 mm away from the base end of the support 50 towards the base end.

[0054] The image acquisition catheter 100 may further include a reinforcing member 71 that reinforces the fixation (joining) of the support body 50 and the outer tube 20 at the position where the film sensor 40 is sandwiched between the support body 50 and the outer tube 20. By having the reinforcing member 71, the image acquisition catheter 100 can more effectively increase the bonding strength of the outer tube 20, the film sensor 40, and the support body 50.

[0055] Furthermore, as mentioned above, the portion where the base end 43 of the film sensor 40 and the tip 61 of the wiring portion 60 are connected is positioned at a location shifted toward the base end from the position where the film sensor 40 is sandwiched between the support 50 and the outer tube 20. If the base end 43 of the film sensor 40 and the tip 61 of the wiring portion 60 were positioned where the reinforcing material 71 is located, when the image acquisition catheter 100 is moved through a bent portion of the biological lumen, the reinforcing material 71 would deform flexibly in accordance with the bending, and excessive deformation of the base end 43 of the film sensor 40 and the tip 61 of the wiring portion 60 could occur to follow this deformation. As a result, fracture or disconnection of the wires may be induced due to the difference in physical properties between the reinforcing material 71 and each component 40, 60. In this embodiment, even if deformation such as bending occurs in the outer tube 20 near the position where the reinforcing material 71 is located as described above, fracture or disconnection of the wires of the film sensor 40 and the wiring portion 60 can be effectively prevented.

[0056] Furthermore, as mentioned above, the image acquisition catheter 100 employs a structure in which at least a portion of the film sensor 40 is sandwiched between the support 50 and the outer tube 20, thereby increasing the bonding strength between the outer tube 20, the film sensor 40, and the support 50. As a result, even when reinforcing material 71 is used, the amount of reinforcing material 71 used can be reduced. This makes it possible to reduce the diameter of the bonding position between the outer tube 20, the film sensor 40, and the support 50. Therefore, when moving the image acquisition catheter 100 along curved parts in the biological lumen, its ability to follow curved parts in the biological lumen can be improved, enabling easier passage.

[0057] As shown in Figure 7, the reinforcing material 71 can be placed in a predetermined area on the outer surface side (outer surface side of the outer tube 20) of the position where the film sensor 40 is sandwiched between the support body 50 and the outer tube 20, and in a part of the area between the inner tube 10 and the outer tube 20 (second lumen 25). By placing the reinforcing material 71 in such a position, the support body 50, the outer tube 20, the inner tube 10, and the film sensor 40 can be joined to each other near the position where the film sensor 40 is sandwiched between the support body 50 and the outer tube 20.

[0058] In the image acquisition catheter 100, the adhesive 56 used for joining members and reinforcing the joint strength, the reinforcing materials 71 and 72, and the joint 85 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.).

[0059] <Outer tube 20> The outer tube 20 is positioned to form a second lumen 25 between itself and the inner tube 10.

[0060] The base end 23 of the outer tube 20 is located on the tip side of the second port 92 of the hand hub portion 90. The base end opening 23a formed in the base end 23 of the outer tube 20 is arranged to communicate with the second port 92. The wiring portion 60 connected to the film sensor 40 is inserted through the second lumen 25 and then led out from the second port 92.

[0061] The outer tube 20 is arranged coaxially with the inner tube 10. The outer tube 20 can be made of the same material as the material exemplified above for the inner tube 10.

[0062] As described above, the tip portion 21 of the outer tube 20 is positioned to sandwich at least a part of the film sensor 40 between itself and the support 50. Furthermore, the tip portion 21 of the outer tube 20 has a tapered shape corresponding to the shape of the tapered portion 53b of the second enlarged diameter portion 53 of the support 50.

[0063] As shown in Figures 3 and 8, the outer tube 20 has a base end region 20C located in a certain range extending from the base end 23 toward the tip end of the outer tube 20.

[0064] The base region 20C has a larger wall thickness and outer diameter than the tip region 20A, which is located in a certain range extending from the tip portion 21 of the outer tube 20 toward the base end.

[0065] As shown in Figures 3 and 8, the outer tube 20 is located between the base region 20C and the tip region 20A, and has an intermediate region 20B in which the wall thickness and outer diameter gradually decrease from the base side to the tip side.

[0066] The image acquisition catheter 100 has an intermediate region 20B in which the wall thickness and outer diameter gradually decrease between the proximal region 20C and the tip region 20A. Therefore, the pushing force applied on the proximal region 20C side (proximal hub portion 90 side) can be smoothly transmitted to the tip region 20A via the intermediate region 20B.

[0067] As shown in Figure 8, the second lumen 25 has a substantially constant inner diameter in the tip region 20A, the intermediate region 20B, and the proximal region 20C. Therefore, the image acquisition catheter 100 can secure a space corresponding to an inner diameter formed with substantially the same size along the axial direction, regardless of the relative sizes of the wall thickness and outer diameter of each region 20A, 20B, and 20C. This makes it possible to place components such as the wiring section 60 and the radiopaque marker 18 within the second lumen 25 partitioned on the outer circumference side of the inner tube 10.

[0068] In this embodiment, the range and dimensions of each region of the outer tube 20 can be defined and set as follows.

[0069] As shown in Figure 8, the tip region 20A of the outer tube 20 can be defined as any region on the base side of the tip portion 21 (a region that does not include the tip portion 21), for example, when the outer diameter of the tip portion 21 of the outer tube 20 expands toward the tip, as in this embodiment. In this case, the position of the tip of the tip region 20A (the boundary position) can be set to the position (starting point) where the expansion toward the tip of the outer tube 20 begins.

[0070] As shown in Figure 8, the base region 20C of the outer tube 20 can be constructed for any length along the axial direction from the most base position (the very base position) of the outer tube 20. The intermediate region 20B can be defined by the region located between the base of the tip region 20A and the tip of the base region 20C (the region connecting the tip region 20A and the base region 20C).

[0071] The wiring section 60 of the image acquisition catheter 100 can be made of a flat cable. Furthermore, as shown in Figures 3 and 8, the wiring section 60 can be arranged spirally along the outer surface of the inner tube 10.

[0072] The wiring section 60 can be made of, for example, a coaxial cable. Alternatively, the wiring section 60 may be made of a flexible cable in which multiple conductor sections 66 are sandwiched between resin films or the like.

[0073] As shown in Figure 8, the image acquisition catheter 100 may have ring-shaped radiopaque markers 18 attached at equal intervals around the outer circumference of the inner tube 10.

[0074] Multiple radiopaque markers 18 can be arranged at regular intervals along the axial direction of the inner tube 10. The radiopaque markers 18 can be made of, for example, a known radiopaque metallic material. Examples of metallic materials that can be used as radiopaque markers 18 include Pt, Pt alloys, W, W alloys, Ag, Ag alloys, etc.

[0075] In procedures using the image acquisition catheter 100, the operator confirms a certain area on the tip side of the image acquisition catheter 100 on an X-ray image or the like. Therefore, the radiopaque marker 18 can be placed, for example, at any position in the inner tube 10 that overlaps with the tip region 20A and the intermediate region 20B located on the tip side of the image acquisition catheter 100.

[0076] The radiopaque marker 18 can be attached to the outer surface of the inner tube 10 by, for example, a ring-shaped metal part through a swaging process. The number, shape, and spacing of the radiopaque markers 18 can be appropriately set according to the specifications of the image acquisition catheter 100.

[0077] Furthermore, the radiopaque marker 18 may be placed not only on the outer surface of the inner tube 10, but also partially or entirely embedded inside the tube wall of the inner tube 10.

[0078] Furthermore, the radiopaque marker 18 can also be composed of, for example, 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 25 can be reduced.

[0079] <Hand-operated hub section 90> The hand-operated hub section 90 has a first port 91 and a second port 92. The hand-operated hub section 90 is connected to the base ends of the inner tube 10 and the outer tube 20.

[0080] The handle hub section 90 is connected to the base end opening of the first port 91 and the first lumen 15 of the inner tube 10 in communication. This allows the handle hub section 90 to insert and remove the guide wire from the inner tube 10. The handle hub section 90 is also connected to the base end opening of the second port 92 and the second lumen 25 of the outer tube 20 in communication. This allows the handle hub section 90 to lead out the base end of the wiring section 60 from the second port 92.

[0081] The hand-held hub section 90 can be made of, for example, a hard resin or metal material applicable in the medical field.

[0082] <External device 300> The external device 300 includes a control unit 310 and a display device 320.

[0083] 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 45a of the film sensor 40, and controls the electrical signals transmitted and received between the transducer 45a and the control unit 310.

[0084] 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 30 of the image acquisition catheter 100.

[0085] 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 30 of the image acquisition catheter 100 to transmit ultrasound, inputs a detection signal from the sensor unit 30, and performs predetermined signal processing based on the detection signal to acquire image data (tomographic image).

[0086] The control unit 310 displays information (video) based on the acquired image data on the display device 320.

[0087] Next, with reference to Figures 9 to 12, a method for arranging the adhesive 56 between the shaft portion 54 of the support 50 and the film sensor 40 in a manufacturing method of the image acquisition catheter 100 according to this embodiment will be described.

[0088] Figure 9 is a schematic diagram showing the coating step of the manufacturing method of the image acquisition catheter 100 according to the embodiment. Figure 10 is a schematic diagram showing the arrangement step of the manufacturing method of the image acquisition catheter according to the embodiment. Figure 11 is a schematic diagram showing the state during the winding step of the manufacturing method of the image acquisition catheter 100 according to the embodiment. Figure 12 is a schematic diagram showing the state when the winding step of the manufacturing method of the image acquisition catheter 100 according to the embodiment is completed.

[0089] The method for manufacturing the image acquisition catheter 100 according to this embodiment generally includes a coating step, a placement step, a winding step, and a heating step.

[0090] In the coating step, as shown in Figure 9, the uncured adhesive 56 is applied to the film sensor 40. The method for applying the uncured adhesive 56 to the film sensor 40 is not particularly limited, but a spray gun, dispenser, or the like can be used.

[0091] In the coating step, as shown in Figure 9, the uncured adhesive 56 is applied along the Y-axis direction of the film sensor 40 so that an exposed surface 40S is formed on the film sensor 40. The uncured adhesive 56 is also applied along the X-axis direction to a length approximately equal to the axial length L1 (see Figure 5) of the shaft portion 54 of the support 50. Furthermore, the adhesive in the X-axis direction is applied to a length that does not come into contact with the enlarged diameter portions 51 and 53 of the support 50, and the adhesive in the Y-axis direction is applied to a length approximately equal to the circumference of the enlarged diameter portions 51 and 53. The amount of adhesive 56 applied is approximately equal to the spatial volume between the support 50 and the film sensor 40 when the film sensor 40 with the adhesive 56 applied is wound around the support 50.

[0092] Next, in the placement step, as shown in Figure 10, the area of ​​the film sensor 40 to which the adhesive 56 has been applied is aligned with the shaft portion 54 of the support 50.

[0093] Specifically, first, the film sensor 40 to which the adhesive 56 has been applied is placed on the lower mold 500. At this time, the film sensor 40 is positioned on the lower mold 500 side. The lower mold 500 is provided with a groove 510, and the groove 510 has an inner diameter that is approximately the same as the sum of the outer diameter of the shaft portion 54 of the support 50 and twice the thickness of the film sensor 40.

[0094] Then, the support 50 is positioned such that the first enlarged diameter portion 51 and the second enlarged diameter portion 53 of the support 50 are positioned along the axial direction on the exposed surface 40S of the film sensor 40 (see Figures 6 and 7). At this time, the support 50 is set up so that the axial position of the adhesive 56 before curing coincides with the axial position of the shaft portion 54 of the support 50.

[0095] Next, in the winding step, as shown in Figures 11 and 12, the film sensor 40 to which the adhesive 56 has been applied is wound around the support 50.

[0096] The winding step includes a first step of moving the support 50 to below the groove 510 of the lower die 500, as shown in Figure 11, and a second step of bringing a pair of spaced-apart upper dies 520 and 530 closer together, as shown in Figure 12. The upper die 520 has a groove 521, and the upper die 530 has a groove 531. When the upper dies 520 and 530 are brought close together, the grooves 521 and 531 have an inner diameter that is approximately the same as the sum of the outer diameter of the shaft portion 54 of the support 50 and twice the thickness of the film sensor 40.

[0097] In the first step, the support 50 is moved to below the groove 510 of the lower mold 500, so that approximately the lower half of the film sensor 40 to which the adhesive 56 has been applied is wrapped around the support 50. As a result, approximately the lower half of the film sensor 40 is wrapped around the support 50, and the adhesive 56 is placed between the film sensor 40 and the support 50.

[0098] The second step is performed by first bringing the upper molds 520 and 530 closer to the lower mold 500 while they are separated, and then bringing the upper molds 520 and 530 closer together.

[0099] In the second step, the upper molds 520 and 530 perform the above-described movement, causing approximately the upper half of the film sensor 40, to which the adhesive 56 has been applied, to be wrapped around the support 50. As a result, the film sensor 40 is wrapped around the support 50 all around, and the adhesive 56 is positioned between the film sensor 40 and the support 50. Figure 12 is shown as a cross-sectional view perpendicular to the axis for ease of understanding.

[0100] For example, in the method of placing adhesive disclosed in the prior art document mentioned above, the space between the flexible circuit and the support member is filled with backing material through multiple recesses (holes) in the main body. However, this method has problems such as the holes in the main body being small, only being able to use low-viscosity adhesives, and the difficulty of injection making it difficult to place the adhesive easily. In contrast, according to the manufacturing method of the image acquisition catheter 100 of this embodiment, since the film sensor 40 coated with adhesive 56 is wrapped around the support 50, high-viscosity adhesives can be used and the adhesive can be placed easily.

[0101] In the heating step, the molds 500, 520, and 530 heat the adhesive 56 before it hardens, causing it to cure. In other words, the molds 500, 520, and 530 are configured to be heatable. With this configuration, the adhesive 56 can be heated and cured immediately after the molds are clamped, without the need to prepare a separate heating means, thus simplifying the manufacturing process.

[0102] As described above, the manufacturing method of the image acquisition catheter 100 according to this embodiment includes the steps of: applying adhesive 56 to the film sensor 40; aligning the area of ​​the film sensor 40 to which the adhesive 56 has been applied with respect to the shaft portion 54 of the support 50; and winding the film sensor 40 around the support 50 with the adhesive 56 of the film sensor 40 positioned toward the shaft portion 54 of the support 50. According to this manufacturing method, the manufacturing method includes the step of winding the film sensor 40 around the support 50 with the adhesive 56 of the film sensor 40 positioned toward the shaft portion 54 of the support 50. For this reason, high-viscosity adhesives can be used and the adhesive can be easily positioned.

[0103] Although the method for manufacturing an image acquisition catheter according to the present invention has been described through embodiments, the present invention is not limited to the method described in the embodiments and can be modified as appropriate based on the claims.

[0104] For example, in the embodiment described above, the molds 500, 520, and 530 heat-cured the adhesive 56 after clamping and wrapping. However, the adhesive 56 may be heat-cured using other heating means (e.g., a heating furnace) while the material is temporarily fixed in the molds 500, 520, and 530, without heating in the molds 500, 520, and 530.

[0105] Furthermore, although the upper mold was divided into two parts in the embodiment described above, it may be configured to be divided into three or more parts.

[0106] This application is based on Japanese Patent Application No. 2024-168269, filed on 27 September 2024, the disclosures of which are cited in their entirety by reference.

[0107] 10 Inner tube 15 First lumen 20 Outer tube 25 Second lumen 30 Sensor section 40 Film sensor 50 Support 51 First enlarged section 53 Second enlarged section 54 Shaft section 56 Adhesive 100 Catheter for image acquisition

Claims

1. A method for manufacturing an image acquisition catheter for acquiring diagnostic ultrasound tomographic images in a biological lumen, comprising: an inner tube having a first lumen extending in the axial direction; a sensor portion disposed at the tip of the inner tube, wherein a plurality of transducers for transmitting and receiving ultrasound waves in the biological lumen are arranged in a ring shape in the circumferential direction; and an outer tube disposed at a position closer to the proximal end than the sensor portion so as to cover at least a portion of the inner tube, forming a second lumen between the inner tube and the outer tube, wherein the sensor portion comprises: a film sensor on which the plurality of transducers are arranged; and a support body for supporting the film sensor, comprising: a pair of axially spaced enlarged diameter portions and a shaft portion located between the pair of enlarged diameter portions. The method for manufacturing an image acquisition catheter comprises: applying an adhesive to the film sensor; aligning the area of ​​the film sensor on which the adhesive has been applied with respect to the shaft portion of the support body; and winding the film sensor around the support body with respect to the film sensor, wherein the adhesive is positioned toward the shaft portion of the support body.

2. The method for manufacturing an image acquisition catheter according to claim 1, wherein the film sensor is wrapped around the support by bringing a pair of spaced-apart molds into close proximity.

3. The method for manufacturing an image acquisition catheter according to claim 2, further comprising the step of winding the film sensor around the support, and then heating the adhesive in the pair of molds to cure it.

4. An imaging catheter for acquiring diagnostic ultrasound tomographic images within a biological lumen, 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 ultrasound waves in the biological lumen are arranged in a ring shape in the circumferential direction; and an outer tube disposed at a position closer to the proximal end than the sensor section so as to cover at least a portion of the inner tube, forming a second lumen between the outer tube 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, comprising a pair of axially spaced enlarged sections and a shaft section located between the pair of enlarged sections, wherein the enlarged sections and the shaft section are closed.

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