Ultrasonic testing device and catheter for intravascular ultrasonic testing

Abstract

Provided is an electrically stable ultrasonic testing device with a reduced outer diameter. An ultrasonic inspection device (14) is provided with: a shaft (21); a first lead (22A) and a second lead (22B) which are inserted through the inner space of the shaft (21) and extend from the distal end of the shaft (21); a conductive film (23) that extends distally from the distal end of the shaft (21) and is electrically connected to the first lead (22A); an ultrasonic probe (25) that is located further toward the distal end of the shaft (21) and has a first electrode layer (52) electrically connected to the conductive film (23) and a second electrode layer (54) electrically connected to the second lead (22B); and a resinous holder (26) that holds at least a portion of the second lead (22B) extending from the shaft (21), the conductive film (23), and the ultrasonic probe (25).

Description

Technical Field

[0001] This invention relates to an ultrasound examination device suitable for insertion into blood vessels and a catheter for intravascular ultrasound examination. Background Technology

[0002] Previously, before performing treatments that involved inserting a catheter into a blood vessel to remove embolisms, a catheter equipped with an ultrasound probe was inserted into the vessel to obtain an ultrasound image of the blood vessel. The outer diameter of the outer axis of the inserted ultrasound probe was less than a few millimeters. Considering factors such as reducing the burden on the patient and inserting into thinner blood vessels, a smaller outer diameter of the catheter is desirable. Furthermore, for use in occlusive lesions and cerebrovascular procedures, a smaller diameter catheter is also desirable. As a method for miniaturizing the ultrasound probe located within the catheter, the manufacturing method described in Patent Document 1 was designed.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 5225670.

[0006] The technical problem that the invention aims to solve

[0007] Ultrasonic probes are connected to leads that supply power or transmit electrical signals. However, even if the ultrasonic probe is miniaturized, it is difficult to reduce the outer diameter of the conduit if the connection to the leads is not miniaturized. On the other hand, if the leads are too thin or the connection is too small, the risk of poor connection such as wire breakage or short circuits increases, making manufacturing difficult. Summary of the Invention

[0008] The present invention was made in view of the following circumstances, and its object is to provide an ultrasonic inspection device that can reduce the outer diameter and is electrically stable.

[0009] Technical means for solving technical problems

[0010] (1) The ultrasonic inspection device according to the present invention comprises: a shaft; a first lead and a second lead, the first lead and the second lead being inserted through the internal space of the shaft and extending from the distal end of the shaft; a conductive film extending distally from the distal end of the shaft and electrically connected to the first lead; an ultrasonic probe located distally from the distal end of the shaft and having a first electrode layer and a second electrode layer, the first electrode layer being electrically connected to the conductive film and the second electrode layer being electrically connected to the second lead; and a resin retainer holding at least the portion of the second lead extending from the shaft, the conductive film, and the ultrasonic probe.

[0011] Since the first lead is electrically connected to the ultrasonic probe through a conductive thin film, the outer diameter of the ultrasonic probe can be reduced.

[0012] (2) Preferably, it also includes an insulating support member located between the distal end of the shaft and the ultrasonic probe and held in the resin retainer, and the insulating support member supports the second lead.

[0013] The possibility of the second lead breaking near the connection point with the ultrasonic probe is suppressed.

[0014] (3) Preferably, the ultrasonic probe is a flat plate formed by stacking a backing layer, a first electrode layer, a piezoelectric element sheet, and a second electrode layer, wherein the conductive film is connected to the first surface of the ultrasonic probe on the backing layer side, and the second lead is connected to the second surface of the second electrode side.

[0015] Because the conductive film and the second lead are not close to each other, the short circuit between the conductive film and the second lead is suppressed.

[0016] (4) Preferably, the first lead and the second lead are coaxial cables with the second lead at the center.

[0017] It can reduce the internal space of the shaft used to insert the first and second leads.

[0018] (5) Preferably, the resin retainer internally holds the portion of the second lead extending from the shaft, the conductive film, and the ultrasonic probe.

[0019] According to the above structure, since the portion of the second lead sensor extending from the shaft, the conductive film, and the ultrasonic probe are insulated by the resin retainer, it is not necessary to perform separate insulation treatment on each component.

[0020] (6) The present invention may also be a catheter for intravascular ultrasound examination, comprising: the ultrasound examination device; and an outer shaft, wherein the ultrasound examination device is rotatably inserted into the outer shaft about the shaft.

[0021] The effects of the invention

[0022] According to the present invention, an ultrasonic inspection device with reduced outer diameter and electrical stability can be realized. Attached Figure Description

[0023] Figure 1 This is a diagram showing the external structure of the catheter 10.

[0024] Figure 2 This is a schematic diagram showing the distal periphery of the ultrasonic inspection device 14.

[0025] Figure 3 This is a three-dimensional view showing the distal periphery of the ultrasonic inspection device 14.

[0026] Figure 4 This is a schematic diagram illustrating the manufacturing method of the ultrasonic inspection device 14.

[0027] Figure 5 This is a schematic diagram illustrating the manufacturing method of the ultrasonic inspection device 14.

[0028] Figure 6 This is a schematic diagram showing the distal periphery of the ultrasonic inspection device 14 involved in the modified example. Detailed Implementation

[0029] The preferred embodiments of the present invention will be described below. Furthermore, this embodiment is merely one embodiment of the present invention, and it is self-evident that the embodiments can be modified without changing the spirit of the present invention.

[0030] [Catheter 10]

[0031] like Figure 1 As shown, the catheter 10 (an example of a catheter for intravascular ultrasound examination) includes an outer shaft 11, a connector 12, a tip 13, and an ultrasound examination device 14 disposed within the outer shaft 11. The catheter 10 is inserted into a blood vessel and used as a medical device for taking ultrasound images of the blood vessel.

[0032] The outer shaft 11 is a tube into which the ultrasound examination device 14 can be rotatably inserted and into the internal space, allowing the flow of liquids such as saline solution. The outer shaft 11 is made of, for example, a round tube of medical-grade stainless steel or a round tube of synthetic resin, possessing flexibility that allows it to bend elastically according to the curvature of the blood vessel. Furthermore, a material that transmits ultrasound waves is selected at the tip of the outer shaft 11. The tip and base of the outer shaft 11 are open. The outer diameter of the outer shaft 11 is set according to the inner diameter of the blood vessel to be inserted, such as the coronary artery, and is, for example, in the range of 0.6 to 1.3 mm. The inner diameter of the outer shaft 11 is set according to the size of the ultrasound examination device 14, and is, for example, in the range of 0.4 to 1.1 mm. The outer and inner diameters of the outer shaft 11 are approximately equal in the axial direction 101 of the outer shaft 11. The length of the axial direction 101 of the outer shaft 11 is set considering the length from the catheter insertion point (e.g., a limb) to the affected area and to the torque generating unit, and is, for example, in the range of 1000 to 1800 mm.

[0033] A connector 12 is connected to the proximal end of the outer shaft 11. The connector 12 is a cylindrical component, and its internal space is continuous with that of the outer shaft 11. The connector 12 is the part that the operator holds to manipulate the catheter 10, and it also forms a connector for connection to an external device (not shown). Although not shown in the figures, the connector 12 is provided with a port for fluid flow, terminals for receiving and transmitting signals, etc.

[0034] A tip 13 is connected to the distal end of the outer shaft 11. The tip 13 is a cylindrical component whose outer diameter tapers into a cone shape towards the distal end, and the internal space of the tip 13 is continuous with the internal space of the outer shaft 11. An opening for inserting a guide wire 15 is formed on the side of the tip 13. The guide wire 15 is inserted from the side of the tip 13 and extends from the opening at the distal end.

[0035] [Ultrasonic Inspection Device 14]

[0036] like Figure 1 , 2 As shown, the ultrasonic examination device 14 includes a shaft 21, a coaxial cable 22, a conductive film 23, an insulating support component 24, an ultrasonic probe 25, a resin retainer 26, a resin tube 61, and a conductive adhesive 27. During the rotation of the ultrasonic examination device 14 within the internal space of the outer shaft 11 about the axial direction 101 of the shaft 21 and its movement towards the proximal end of the outer shaft 11, an electrical signal is output from the ultrasonic probe 25. Based on the electrical signal output from the ultrasonic examination device 14, an external device (not shown) generates and displays an image of the blood vessel.

[0037] The shaft 21 is a tube that allows the coaxial cable 22 to be inserted into its internal space and transmits rotational torque from the proximal end to the distal end. The shaft 21 is constructed, for example, from medical-grade stainless steel wire wound into a double-coil shape, possessing flexibility that allows it to bend elastically according to the curvature of a blood vessel. Alternatively, the shaft 21 can also be a triple-coil shape. When the shaft 21 is a triple-coil shape, the first and third layers are composed of coils with the same helical direction, while the second layer is composed of coils with a different helical direction. The outer diameter of the shaft 21 is preferably as small as possible, for example, in the range of 0.35 to 1.0 mm. The outer diameter of the shaft 21 is approximately equal along its axial direction 101. The length of the shaft 21 along its axial direction 101 is set considering the length from the insertion point of the catheter (e.g., in the limbs) to the affected area and to the torque generating unit, and is, for example, in the range of 1000 to 1800 mm.

[0038] At the center of the coaxial cable 22, a conductive second lead 22B, covered with insulation, extends linearly. A first lead 22A is located around the second lead 22B, and the first lead 22A is surrounded by insulating material. The second lead 22B can be a bundle of multiple thin wires covered with insulation, or it can be a single wire. The first lead 22A consists of multiple thin wires arranged around the outer periphery of the second lead 22B. The multiple thin wires constituting the first lead 22A can also extend linearly along the second lead, or they can be twisted together. Figure 2 The portion of the first lead 22A extending distally from the shaft 21 is twisted together with the second lead 22B in a circumferential direction to form a single wire bundle. The distal ends of the first lead 22A and the second lead 22B extend distally from the shaft 21 and are electrically connected to the ultrasonic probe 25, respectively. The proximal ends of the first lead 22A and the second lead 22B are electrically connected to an external device (not shown). Electric signals are received and transmitted between the ultrasonic probe 25 and the external device via the first lead 22A and the second lead 22B.

[0039] The first lead 22A is electrically connected to the ultrasonic probe 25 via the conductive film 23. The conductive film 23 is a conductive component or a thin film-shaped component with conductive components laminated on its surface. The conductive film 23 is rectangular when viewed from above, and its width dimension (…) Figure 2 The dimension perpendicular to the paper plane) is the same as or smaller than the width of the ultrasonic probe 25, and the length dimension of the conductive film 23 ( Figure 2 The dimensions (in the left-right direction) are sufficiently long compared to the length of the ultrasonic probe 25; for example, the width is in the range of 0.2–0.5 mm, and the length is in the range of 1.0–10 mm. Additionally, the thickness of the conductive film 23 (…) Figure 2 The dimensions (in the vertical direction) are sufficiently thin compared to the thickness of the ultrasonic probe 25 and the outer diameter of the coaxial cable 22, for example, in the range of 10 to 200 μm. A conductive film 23 extends distally from the distal end of the shaft 21 and contacts and is electrically connected to the lower surface (an example of the first surface) of the ultrasonic probe 25. The distal end of the first lead 22A contacts and is electrically connected to the conductive film 23 between the distal end of the shaft 21 and the ultrasonic probe 25.

[0040] The ultrasonic probe 25 is located at the distal end of the conductive film 23. The ultrasonic probe 25 is flat and generates ultrasonic waves through the piezoelectric ceramic when an alternating voltage is applied. To minimize the diameter of the ultrasonic inspection device 14, the ultrasonic probe 25 is preferably small. In this embodiment, the ultrasonic probe 25 has an elongated shape where the length is longer than the width, for example, a width in the range of 0.3–0.5 mm, a length in the range of 0.6–1.0 mm, and a thickness in the range of 0.2–0.4 mm.

[0041] The ultrasonic probe 25 is constructed by sequentially stacking a backing layer 51, a first electrode layer 52, a piezoelectric ceramic sheet 53 (an example of a piezoelectric element sheet), and a second electrode layer 54 from bottom to top. Alternatively, the ultrasonic probe 25 may have an acoustic matching layer stacked on the second electrode layer 54, or other layers sandwiched between them. The backing layer 51 is stacked for sound absorption and is conductive. A conductive film 23 contacts and is electrically connected to the backing layer 51. As a result, the first lead 22A and the first electrode layer 52 are electrically connected. With the insulating cover removed, the distal end of the second lead 22B is electrically connected to the proximal side of the second electrode layer 54 on the upper surface (an example of the second surface) of the ultrasonic probe 25 by a conductive adhesive.

[0042] An insulating support member 24 is located between and adjacent to the distal end of the first lead 22A and the ultrasonic probe 25. The insulating support member 24 is a flat-shaped component made of insulating resin such as acrylic, and has a groove 24B formed on its upper surface 24A along the axial direction 101 for the insertion of a second lead 22B. The second lead 22B is supported by the insulating support member 24 by being inserted into the groove 24B. The lowest point of the surface dividing the groove 24B is preferably at the same level as or slightly below the upper surface of the ultrasonic probe 25. Alternatively, the surface dividing the groove 24B may slope downwards from the distal end to the proximal end. If the length of the insulating support member 24 along the groove 24B is too long, blood vessel permeability will deteriorate; therefore, it is preferably in the range of 0.2 to 0.5 mm.

[0043] The resin retainer 26 encloses and holds the portion extending from the shaft 21 of the second lead 22B, a portion of the distal side of the conductive film 23, the insulating support member 24, and the ultrasonic probe 25. The resin retainer 26 is, for example, an ultraviolet-curable resin.

[0044] Resin tubes 61 and 62 are molded articles formed from synthetic resin into a tube shape. Examples of synthetic resins include polyamide elastomers. The inner diameter of resin tube 62 is similar to, but slightly larger than, the outer diameter of resin tube 61.

[0045] As a conductive adhesive 27, examples include epoxy resins containing silver, nickel, etc.

[0046] [Manufacturing method of ultrasonic inspection device 14]

[0047] The ultrasonic inspection device 14 is manufactured, for example, by the following manufacturing method.

[0048] like Figure 4As shown, the first lead 22A extending distally from the distal end of shaft 21 and the conductive film 23 extending distally from the distal end of shaft 21 are located within the internal space of resin tube 61. Additionally, the portion of the second lead 22B, excluding its tip, is located within the internal space of resin tube 61. The proximal end of resin tube 61 is proximal to the distal end of shaft 21, and the distal end of resin tube 61 is distal to the distal end of the first lead 22A but proximal to the distal end of the conductive film 23. At this time, the insulating support member 24 and the ultrasonic probe 25 can be connected to the conductive film 23, or they can be temporarily omitted.

[0049] With the shaft 21 and the first lead 22A held within the internal space of the resin tube 61, a conductive adhesive 27 is filled into the internal space from the distal end of the resin tube 61 and allowed to cure. As a result, a conductive film 23 is fixed to the distal end of the shaft 21, and the conductive film 23 is bonded to and electrically connected to the first lead 22A.

[0050] Next, as Figure 5 As shown, the insulating support component 24 and the ultrasonic probe 25 are connected to the conductive film 23. The second lead 22B is supported on the insulating support component 24 and is inserted into the internal space of the resin tube 62 while electrically connected to the upper surface of the ultrasonic probe 25. The proximal end of the resin tube 62 is located closer to the distal end of the first lead 22A, and the distal end is located farther from the ultrasonic probe 25.

[0051] UV-curable resin is filled into the internal space from the distal end of resin tube 62 and cured. Subsequently, resin tube 62 is removed. The cured UV-curable resin becomes resin retainer 26, which encapsulates and retains the portion of the second lead 22B extending from resin tube 61, a portion of the distal side of conductive film 23, insulating support member 24, and ultrasonic probe 25.

[0052] [Effects of this implementation method]

[0053] According to the ultrasonic inspection apparatus 14 of this embodiment, since the first lead 22A is electrically connected to the ultrasonic probe 25 through the conductive film 23, the ultrasonic inspection apparatus 14 with reduced outer diameter around the ultrasonic probe 25 and electrical stability can be realized.

[0054] In addition, since the second lead 22B is supported by the insulating support member 24, it is possible to suppress the possibility of the second lead 22B breaking near the connection point with the ultrasonic probe 25.

[0055] In addition, since the conductive film 23 is connected to the lower surface of the ultrasonic probe 25 and the second lead 22B is connected to the upper surface of the ultrasonic probe 25, the conductive film 23 and the second lead 22B are not close to each other, and the short circuit between the conductive film 23 and the second lead 22B is suppressed.

[0056] In addition, since the first lead 22A and the second lead 22B are coaxial cables, the internal space (inner diameter) of the shaft 21 can be reduced.

[0057] Furthermore, since the resin holder 26 internally holds the portion of the second lead 22B extending from the shaft 21, the conductive film 23, and the ultrasonic probe 25, these components are insulated by the resin holder 26. Therefore, it is not necessary to insulate each component separately. In addition, since the resin holder 26 integrally covers these components, the shape of the resin holder 26 has a high degree of freedom and can be molded into a desired shape.

[0058] Furthermore, the resin tube 61 prevents the conductive adhesive 27, which is a relatively soft material, from partially peeling off. This effect is particularly noticeable when the ultrasonic inspection device 14 is subjected to loads, such as during rotation.

[0059] [Variation Example]

[0060] Furthermore, in the above embodiment, the second lead 22B is supported by the insulating support member 24, but the insulating support member 24 may not be provided. Additionally, the first lead 22A and the second lead 22B may not be coaxial cables, but may be wires that are independently insulated. Alternatively, the ultrasonic probe 25 may be tilted and held in the resin holder 26 with its upper surface appropriately tilted. For example, the upper surface of the ultrasonic probe 25 may be tilted by increasing the thickness of the distal end of the conductive film 23.

[0061] Furthermore, in the above embodiment, the distal end of the second lead 22B, with the insulating cover removed, is electrically connected to the proximal side of the second electrode layer 54 by bonding it to the upper surface of the ultrasonic probe 25 with a conductive adhesive. However, the distal end of the second lead 22B can also be electrically connected to the ultrasonic probe 25 through a conductive film. Figure 6In this embodiment, the conductive film 28 extends distally and proximally relative to the insulating support member 24. The conductive film 28 is electrically connected to the distal end of the second lead 22B where the insulating cover is removed. The conductive film 28 is laminated onto a portion of the proximal side of the second electrode layer 54 of the ultrasonic probe 25 and is electrically connected. Thus, the second lead 22B is electrically connected to the second electrode layer 54 of the ultrasonic probe 25 via the conductive film 28. The conductive film 28 is a conductive component or a thin film-shaped component with conductive components laminated on its surface. The conductive film 28 is supported by the insulating support member 24. Therefore, the outer diameter of the resin tube 61 can be smaller than in the embodiment described above.

[0062] Furthermore, the manufacturing method of the ultrasonic inspection device 14 is not limited to the method shown in the embodiment. For example, instead of using resin tubes 61 and 62, the distal end of the shaft 21, the first lead 22A, the second lead 22B, the conductive film 23, the insulating support member 24, and the ultrasonic probe 25 are held within the internal space of a resin tube, and then ultraviolet-curable resin is filled into the internal space of the resin tube and cured. In this case, the resin holder 26 encloses and holds the distal end of the shaft 21, the portions of the first lead 22A and the second lead 22B extending from the shaft 21, the conductive film 23, the insulating support member 24, and the ultrasonic probe 25. Alternatively, the shape of the resin holder 26 can be desired by placing the resin tube in a mold and filling it with ultraviolet-curable resin or the like.

[0063] Symbol Explanation

[0064] 10...Catheter (catheter for intravascular ultrasound examination)

[0065] 11...Outer shaft

[0066] 14...Ultrasonic inspection device

[0067] 21... axis

[0068] 22...coaxial cable

[0069] 22A...First lead

[0070] 22B...Second lead

[0071] 23, 28... conductive thin films

[0072] 24...Insulating support components

[0073] 25... Ultrasonic probe

[0074] 26... Resin retainer

[0075] 51...backing layer

[0076] 52...First Electrode Layer

[0077] 53... Piezoelectric ceramic sheet

[0078] 54...Second electrode layer.

Claims

1. An ultrasonic testing apparatus characterized by comprising: Possessing: a shaft; a first lead wire and a second lead wire that are inserted through an inner space of the shaft and extend from a distal end of the shaft; a conductive film that extends distally from the distal end of the shaft and is electrically connected to the first lead wire; an ultrasonic probe that is located distally from the distal end of the shaft and has a first electrode layer electrically connected to the conductive film and a second electrode layer electrically connected to the second lead wire; and a resin holding body that holds at least the portion of the second lead wire that extends from the shaft, the conductive film, and the ultrasonic probe.

2. The ultrasonic examination apparatus according to claim 1, further comprising an insulating support member that is located between the distal end of the shaft and the ultrasonic probe, held by the resin holding body, and supports the second lead wire.

3. The ultrasonic examination apparatus according to claim 1 or 2, wherein the ultrasonic probe is a flat plate shape in which a backing layer, the first electrode layer, a piezoelectric element sheet, and the second electrode layer are stacked, the conductive film is connected to a first face of the backing layer side of the ultrasonic probe, and the second lead wire is connected to a second face of the second electrode side.

4. The ultrasonic examination apparatus according to claim 1 or 2, wherein the first lead wire and the second lead wire are a coaxial cable in which the second lead wire is located at the center.

5. The ultrasonic examination apparatus according to claim 1, wherein the resin holding body holds the portion of the second lead wire that extends from the shaft, the conductive film, and the ultrasonic probe inside. Possessing: the ultrasonic examination apparatus according to claim 1; and an outer shaft into which the ultrasonic examination apparatus is rotatably inserted with the shaft as an axis. ​ ​ ​ ​ 6. An intravascular ultrasound examination catheter characterized by, ​ ​ ​

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