Ultrasonic probe

Abstract

To provide an ultrasonic probe in which a swingable ultrasonic vibrator unit and an acoustic coupling liquid are built in a housing and a coaxial cable is used between the ultrasonic vibrator unit and an image diagnostic device, and which has a structure capable of easily reducing the generation of bubbles in the acoustic coupling liquid.SOLUTION: A co-axial cable 17 is constituted of a first co-axial cable 17a, one end of which is connected to an ultrasonic vibrator unit and the other end of which is connected to one end of a flexible printed board and which is built in a casing, and a second co-axial cable 17b, one end of which is connected to the other end of the flexible printed board and the other end of which is connected to an image diagnostic device. The ultrasonic probe includes a liquid-tight structure part 21 for mounting the flexible printed board 19 in a casing in a liquid-tight state, and the flexible printed board 19.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an ultrasonic probe having a structure in which a oscillating ultrasonic transducer unit and an acoustic coupling liquid are housed in a housing. [Background technology]

[0002] Ultrasonic probes are used in a variety of fields, and in particular in the medical field, they are essential for diagnosing internal diseases of the human body. One example of an ultrasound probe is one that has a structure in which a swayable ultrasound transducer unit and an acoustic coupling liquid are housed in a housing (see, for example, Patent Document 1). By using a swayable ultrasound transducer unit, three-dimensional image information can be obtained, providing a wealth of information useful for diagnosis. By using an acoustic coupling liquid, the ultrasound transducer unit can efficiently transmit and receive ultrasound. Another example of this type of ultrasound probe is one for use in body cavities (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-11236 [Patent Document 1] Japanese Patent Application Publication No. 2019-17637 Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors of this application have also been developing an ultrasound probe for body cavities that incorporates a swayable ultrasound transducer unit and an acoustic coupling liquid in a housing. Furthermore, they have been developing an ultrasound probe that uses a swayable ultrasound transducer unit with multiple transducers and a multi-core coaxial cable to improve signal shielding. However, as will be described in detail later, ultrasound probes in the development stage faced the problem of air bubbles being generated in the acoustic coupling liquid when the ultrasound transducer unit was oscillated. Because air bubbles cause a decrease in the performance of the ultrasound probe, a technology that can reduce the generation of air bubbles is desired. This application has been made in consideration of the above points, and therefore, an object of the application is to provide a novel ultrasonic probe that has a structure in which a oscillating ultrasonic transducer unit and an acoustic coupling liquid are housed in a housing, and that is a type of ultrasonic probe that uses a coaxial cable, and that has a structure that makes it easy to reduce the generation of bubbles in the acoustic coupling liquid. [Means for solving the problem]

[0005] In order to achieve this object, the ultrasonic probe of the present invention includes a housing, a swayable ultrasonic transducer unit and an acoustic coupling liquid housed in the housing, and a coaxial cable connecting the ultrasonic transducer unit to an external diagnostic imaging device, the coaxial cable is composed of a first coaxial cable, one end of which is connected to the ultrasound transducer unit and the other end of which is connected to one end of a flexible printed circuit board, and is built into the housing; and a second coaxial cable, one end of which is connected to the other end of the flexible printed circuit board, and the other end of which is connected to an external diagnostic imaging device; the flexible printed circuit board; a liquid-tight structure for mounting the flexible printed circuit board in the housing in a liquid-tight state; The present invention is characterized by the following features.

[0006] In carrying out this invention, it is preferable that the housing be long, the ultrasonic transducer unit be built into one end of the housing, and the flexible printed circuit board be mounted on the other end. The ultrasonic probe is preferably for use in a body cavity. When the housing is long, as in an ultrasonic probe for a body cavity, the coaxial cable mounted within the housing is long. A longer coaxial cable has a correspondingly larger gap between the outer sheath and the core wire, resulting in a greater amount of trapped air bubbles. In such cases, using a first coaxial cable with both ends open within the housing, as in the present invention, makes it easier to degas the air bubbles present between the outer sheath and the core wire, thereby reducing the generation of air bubbles in the acoustic coupling liquid. [Effects of the Invention]

[0007] The ultrasound probe of this application has a structure in which a coaxial cable is divided into two parts. Since both ends of the first coaxial cable are open to the acoustic coupling liquid, air in the gap between the outer sheath and core of the first coaxial cable is easily degassed in a degassing process performed before the housing is filled with the acoustic coupling liquid. When only one end of the coaxial cable is open and the other end is connected to an external diagnostic imaging device (as in the comparative example described below), the air in the gap between the outer sheath and core of the long coaxial cable becomes a source of air bubbles, potentially causing bubbles to form in the acoustic coupling liquid for a long period of time. However, this problem can be avoided with the structure of the present invention. Furthermore, in the case of the present invention, a flexible printed circuit board is used as a relay member between the first and second coaxial cables. This makes it easy to accommodate multi-core coaxial cables, achieve liquid-tightness, and enhance electromagnetic shielding, as will be described in detail later. Therefore, it is possible to provide a novel ultrasonic probe having a structure that can easily reduce the generation of bubbles in the acoustic coupling liquid. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram for explaining the overall structure of an ultrasonic probe 10 according to an embodiment. [Figure 2]2 is an exploded view for explaining details of the ultrasonic probe 10 according to the embodiment. FIG. [Figure 3] FIG. 2 is a diagram for explaining an ultrasonic probe 50 of a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that each drawing used for the description is merely a schematic illustration to enable understanding of the present invention. Furthermore, in each drawing used for the description, similar components are designated by the same numbers, and their description may be omitted. Furthermore, the shapes, materials, etc. described in the following embodiments are merely preferred examples within the scope of the present invention. Therefore, the present invention is not limited to the following embodiments.

[0010] 1. Configuration of Ultrasound Probe 10 of the Embodiment As an embodiment of the present invention, an example in which the present invention is applied to an ultrasound probe for a body cavity will be described. Figures 1 and 2(A) and (B) are explanatory diagrams for this purpose. In particular, Figure 1 is a diagram for explaining the overall structure of the ultrasound probe 10 of the embodiment, Figure 2(A) is an exploded view for explaining the details of the ultrasound probe 10 of the embodiment, and Figure 2(B) is an enlarged cross-sectional view of part M in Figure 2(A) taken along line SS. Note that Figure 1 also shows an external diagnostic device 30 to which the ultrasound probe 10 is connected. This ultrasonic probe 10 includes a housing 11, a swayable ultrasonic transducer unit 13 and an acoustic coupling liquid 15 housed in the housing 11, a coaxial cable 17 connecting the ultrasonic transducer unit 13 to an external diagnostic imaging device 30, a flexible printed circuit board 19, and a liquid-tight structure 21. However, in Figures 1 and 2, illustrations of a drive mechanism for swaying the ultrasonic transducer unit 13 and the like are omitted.

[0011] One of the features of the ultrasonic probe 10 of the present invention is that the coaxial cable 17 is composed of a first coaxial cable 17a, one end of which is connected to the ultrasonic transducer unit 13 and the other end of which is connected to one end of a flexible printed circuit board 19, and a second coaxial cable 17b, one end of which is connected to the other end of the flexible printed circuit board 19 and the other end of which is connected to an external diagnostic device 30. Another feature is that the ultrasonic probe 10 includes a liquid-tight structure 21 that mounts the flexible printed circuit board 19 in a liquid-tight state in the housing 11, and the flexible printed circuit board 19. The specific structure of each component will be described below.

[0012] In this example, the housing 11 is long in order to constitute an ultrasound probe for a body cavity. In this example, the housing 11 is made up of two parts, each having an outer wall of a predetermined thickness, and is designed so that the two parts can be bonded together with adhesive or the like after an ultrasound transducer unit and the like are installed inside. The material of the housing 11 can be any material depending on the design of the ultrasound probe, such as resin, metal, or metal coated with resin. The ultrasound transducer unit 13 is built into one end of the housing 11, and a flexible printed circuit board 19 is installed at the other end of the housing 11 via a liquid-tight structure 21.

[0013] The ultrasonic transducer unit 13 has a large number of transducers arranged in a fan shape in this example. The number of transducers is determined depending on the resolution and amount of image information required for the ultrasonic probe 10. Although not limited to this, it is, for example, 128. Each transducer can be made of, for example, piezoelectric ceramic. Each transducer is provided with a predetermined electrode, which is connected to the imaging diagnostic device 30 via first and second coaxial cables 17a and 17b described below. In this example, the ultrasonic transducer unit 13 oscillates as indicated by arrow Q around the center P of the fan (see FIG. 1). Although not shown, a shaft and gear from a motor are connected to the ultrasonic transducer unit 13. The acoustic coupling liquid 15 fills the internal space of the housing 11 and improves the acoustic matching of the ultrasonic waves transmitted and received through the wall of the housing 11 with the ultrasonic transducer unit 13 .

[0014] One end of the first coaxial cable 17a is connected to the ultrasonic transducer unit 13, and the other end is connected to one end of the flexible printed circuit board 19. Therefore, the first coaxial cable 17a is mounted in the housing 11 with both ends open. Therefore, at each end of the first coaxial cable 17a, a gap 17z between the outer sheath 17x and the core wire 17y is in contact with the space within the housing 11, i.e., is in an open relationship. One end of the second coaxial cable 17b is connected to the other end of the flexible printed circuit board 19, and the other end is connected to the external diagnostic device 30. Therefore, the second coaxial cable 17b is positioned so as not to come into contact with the internal space of the housing 11.

[0015] The flexible printed circuit board 19 can be made of any suitable known material. The flexible printed circuit board 19 has wiring for the number of transducers provided in the ultrasonic transducer unit 13 plus α. However, the flexible printed circuit board 19 is covered with a liquid-tight structure 21 (described later) to prevent the acoustic coupling liquid 15 from leaking out of the housing 11 from this portion.

[0016] In this example, the liquid-tight structure 21 is composed of an adapter 21a, a filler 21b, and a packing 21c, as shown in FIG. 2 . Specifically, the adapter 21a is a cylindrical member that houses the core wire at the other end of the first coaxial cable 17a, the flexible printed circuit board 19, and the core wire at one end of the second coaxial cable 17b. The adapter 21a is preferably made of metal and is preferably connected to earth to provide an electromagnetic shielding effect. The filler 21b fills the gap between the adapter 21a and the flexible printed circuit board 19 and other components within the adapter 21a. The filler 21b can be made of, but is not limited to, silicone resin, for example. The packing 21c ensures liquid-tightness between the housing 11 and the adapter 21a and can be made of, for example, rubber packing. The liquid-tight structure 21, which is made up of the adapter 21a, the filler 21b, and the packing 21c, prevents the acoustic coupling liquid 15 in the housing 11 from leaking out of the housing 11.

[0017] 2. Functions and Effects of the Ultrasonic Probe 10 of the Embodiment Next, the operation and effect of the ultrasonic probe 10 of the embodiment will be described with reference to Fig. 1. In the ultrasonic probe 10 of the embodiment, the first coaxial cable 17a is built into the internal space of the housing 11, and both ends are open, so that the gap 17z between the outer sheath 17x and the core wire 17y at both ends of the first coaxial cable 17a comes into contact with the internal space of the housing 11. Therefore, in the degassing operation of the internal space of the housing 11, which is performed before filling the space of the housing 11 with the acoustic coupling liquid 15, the air in the gap 17z of the first coaxial cable 17a can be efficiently degassed from both ends of the first coaxial cable 17a. Therefore, compared to the comparative example described below, the risk of the coaxial cable becoming a source of air bubbles can be reduced. Therefore, even if the first coaxial cable 17a vibrates when the ultrasonic transducer unit 13 is swung, the risk of air bubbles being generated can be reduced.

[0018] 3. Comparative Example FIG. 3 is a diagram illustrating an ultrasonic probe 50 of a comparative example. The ultrasonic probe 50 of the comparative example differs from the present invention in that a single coaxial cable 51 is used to connect the ultrasonic transducer unit 13 to the diagnostic imaging device 30. That is, at one end of the coaxial cable 51, a core wire 51y is connected to the ultrasonic transducer unit 13, and the other end is connected to the diagnostic imaging device 30 via the housing 11. Therefore, the gap between the outer sheath 51x and the core wire 51y of the coaxial cable 51 is configured so that only one end of the coaxial cable 51 comes into contact with the acoustic coupling liquid 15 in the internal space of the housing 11. Therefore, the coaxial cable 51, which is much longer than that of the embodiment, comes into contact with the acoustic coupling liquid 15. Therefore, the large amount of air stored in the gap 51z between the outer sheath 51x and the core wire 51y of the coaxial cable 51, which is much longer than that of the embodiment, cannot be removed simply by degassing and remains in the product even after completion. Therefore, in the comparative example, when the ultrasonic transducer unit 13 is oscillated, bubbles are more likely to be generated. In the above-described embodiment, an example in which the present invention is applied to an ultrasound probe for a body cavity has been described, but the present invention can be applied to various ultrasound probes having a structure in which a oscillating ultrasound transducer unit and an acoustic coupling liquid are housed in a housing. [Explanation of symbols]

[0019] 10: Ultrasonic probe of embodiment 11: Housing 13: Ultrasonic transducer unit 15: Acoustic coupling liquid 17a: First coaxial cable 17b: Second coaxial cable 17x: Outer sheath 17y: Core wire 17z: Gap 19: Flexible printed circuit board 21: Liquid-tight structure 21a: Adapter 21b: Filler 21c: Packing 50: Ultrasonic probe of comparative example

Claims

1. An ultrasound probe comprising a housing, a swayable ultrasound transducer unit and an acoustic coupling liquid housed in the housing, and a coaxial cable connecting the ultrasound transducer unit to an external diagnostic imaging device, the coaxial cable is composed of a first coaxial cable, one end of which is connected to the ultrasound transducer unit and the other end of which is connected to one end of a flexible printed circuit board, and is built into the housing; and a second coaxial cable, one end of which is connected to the other end of the flexible printed circuit board, and the other end of which is connected to an external diagnostic imaging device, the flexible printed circuit board; a liquid-tight structure for mounting the flexible printed circuit board in the housing in a liquid-tight state; An ultrasonic probe comprising:

2. 2. The ultrasonic probe according to claim 1, wherein the housing is elongated, the ultrasonic transducer unit is built in at one end of the housing, and the flexible printed circuit board is mounted at the other end.

3. The liquid-tight structure is a cylindrical adapter that houses the core wire at the other end of the first coaxial cable, the flexible printed circuit board, and the core wire at one end of the second coaxial cable; a filler filled in the adapter; and a packing provided between the outer wall of the adapter and the housing; 2. The ultrasonic probe according to claim 1, comprising:

4. 4. The ultrasonic probe according to claim 1, wherein the ultrasonic probe is an ultrasonic probe for a body cavity.

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