阅读说明：本技术 超声波振子 (Ultrasonic vibrator ) 是由 井口阳 于 2020-03-23 设计创作，主要内容包括：本发明的超声波振子具有压电元件、和支承所述压电元件的支承部件,其中,所述压电元件由如下部分构成：扁平状的压电体；层叠于所述压电体的厚度方向上的至少一侧的第1电极；和层叠于所述压电体的所述厚度方向上的至少另一侧的第2电极,所述支承部件具有：与所述压电元件的所述第1电极连接的第1端子；和与所述压电元件的所述第2电极连接的第2端子,所述第1端子以及所述第2端子具有在所述厚度方向上没有与所述压电元件重叠的部分。(An ultrasonic transducer according to the present invention includes a piezoelectric element and a support member for supporting the piezoelectric element, wherein the piezoelectric element includes: a flat piezoelectric body; a1 st electrode laminated on at least one side in a thickness direction of the piezoelectric body; and a2 nd electrode laminated on at least the other side of the piezoelectric body in the thickness direction, the support member including: a1 st terminal connected to the 1 st electrode of the piezoelectric element; and a2 nd terminal connected to the 2 nd electrode of the piezoelectric element, the 1 st terminal and the 2 nd terminal having portions that do not overlap with the piezoelectric element in the thickness direction.)

1. An ultrasonic transducer comprising a piezoelectric element and a support member for supporting the piezoelectric element,

the piezoelectric element is composed of:

a flat piezoelectric body;

a1 st electrode laminated on at least one side in a thickness direction of the piezoelectric body; and

a2 nd electrode laminated on at least the other side in the thickness direction of the piezoelectric body,

the support member has:

a1 st terminal connected to the 1 st electrode of the piezoelectric element; and

a2 nd terminal connected to the 2 nd electrode of the piezoelectric element,

the 1 st terminal and the 2 nd terminal have portions that do not overlap with the piezoelectric element in the thickness direction.

2. The ultrasonic vibrator according to claim 1, wherein,

the support member includes a support body portion laminated on the piezoelectric element on the other side in the thickness direction and extending to a position outside the piezoelectric element in a direction orthogonal to the thickness direction,

the 1 st terminal and the 2 nd terminal are supported by the support main body portion.

3. The ultrasonic vibrator according to claim 2, wherein,

the 1 st electrode of the piezoelectric element has:

a surface electrode layer located on the one side in the thickness direction of the piezoelectric body;

a back electrode layer located on the other side in the thickness direction of the piezoelectric body; and

and a connection conductive portion connecting the front surface electrode layer and the back surface electrode layer.

4. The ultrasonic vibrator according to claim 3, wherein,

the 1 st terminal is connected to the back surface electrode layer of the 1 st electrode between the piezoelectric element and the support main body portion.

5. The ultrasonic vibrator according to any one of claims 2 to 4, wherein,

the 2 nd terminal is connected to the 2 nd electrode between the piezoelectric element and the support main body portion.

6. The ultrasonic vibrator according to any one of claims 2 to 5,

the piezoelectric element includes:

a1 st portion composed of a portion overlapping with the 1 st terminal and a portion overlapping with the 2 nd terminal in the thickness direction; and

a2 nd part other than the 1 st part,

the entire area of the other side in the thickness direction of the 2 nd portion is covered with the support main body portion.

Technical Field

The present invention relates to an ultrasonic transducer.

Background

An ultrasonic probe including an ultrasonic transducer is used as a transceiver for ultrasonic waves in a medical ultrasonic diagnostic apparatus. The following methods are being adopted recently: an ultrasonic probe is loaded into the catheter, and ultrasonic diagnosis is performed in a state where the catheter is inserted into the body.

Patent document 1 discloses an ultrasonic probe including: an active sensor element having a top major surface and a bottom major surface; a top electrode formed on the top major surface; a bottom electrode formed on the bottom major surface; a conductive gasket member covering the bottom electrode; a1 st conductive line electrically connected to the top electrode; and a2 nd conductive line electrically connected to the conductive gasket member.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2006-198425

Disclosure of Invention

In an ultrasonic probe to be loaded into a catheter, there is a high demand for downsizing in order to reduce the burden on a patient and to improve the insertability into a body cavity having a smaller diameter such as a deep part of a blood vessel.

The miniaturization of the ultrasonic probe can be achieved by miniaturizing an ultrasonic transducer including a piezoelectric element including a piezoelectric body and a pair of electrodes. However, when the ultrasonic transducer is downsized, the piezoelectric element is also reduced in size. Therefore, the electrodes of the piezoelectric element are also small, and the operation of connecting the electric signal lines connecting the piezoelectric element and an external power supply to the electrodes of the piezoelectric element becomes difficult.

An object of the present invention is to provide an ultrasonic transducer having a structure in which an electric signal line is easily connected to a piezoelectric element.

An ultrasonic transducer according to claim 1 of the present invention includes a piezoelectric element and a support member for supporting the piezoelectric element, wherein the piezoelectric element includes: a flat piezoelectric body; a1 st electrode laminated on at least one side in a thickness direction of the piezoelectric body; and a2 nd electrode laminated on at least the other side of the piezoelectric body in the thickness direction, the support member including: a1 st terminal connected to the 1 st electrode of the piezoelectric element; and a2 nd terminal connected to the 2 nd electrode of the piezoelectric element, the 1 st terminal and the 2 nd terminal having portions that do not overlap with the piezoelectric element in the thickness direction.

In one embodiment of the present invention, the support member includes a support main body portion that is laminated on the piezoelectric element on the other side in the thickness direction, and extends to a position outside the piezoelectric element in a direction orthogonal to the thickness direction, and the 1 st terminal and the 2 nd terminal are supported by the support main body portion.

In one embodiment of the present invention, the 1 st electrode of the piezoelectric element includes: a surface electrode layer located on the one side in the thickness direction of the piezoelectric body; a back electrode layer located on the other side in the thickness direction of the piezoelectric body; and a connection conductive portion connecting the front surface electrode layer and the back surface electrode layer.

In one embodiment of the present invention, the 1 st terminal is connected to the back surface electrode layer of the 1 st electrode between the piezoelectric element and the support main body portion.

In one embodiment of the present invention, the 2 nd terminal is connected to the 2 nd electrode between the piezoelectric element and the support main body portion.

As one embodiment of the present invention, the piezoelectric element includes: a1 st portion composed of a portion overlapping with the 1 st terminal and a portion overlapping with the 2 nd terminal in the thickness direction; and a2 nd portion other than the 1 st portion, an entire area of the other side in the thickness direction of the 2 nd portion being covered by the support main body portion.

Effects of the invention

According to the present invention, it is possible to provide an ultrasonic transducer having a structure in which an electric signal line is easily connected to a piezoelectric element.

Drawings

Fig. 1 is a diagram showing a state in which a catheter for image diagnosis including an ultrasonic transducer according to an embodiment of the present invention is connected to an external device.

Fig. 2 is a cross-sectional view showing a cross section parallel to the longitudinal direction in the distal end portion of the catheter for image diagnosis shown in fig. 1.

Fig. 3 is a diagram showing an ultrasonic transducer of the catheter for image diagnosis shown in fig. 1.

Fig. 4 is a view showing the back surface of the piezoelectric element in the ultrasonic transducer shown in fig. 3.

Fig. 5 is an exploded perspective view of the ultrasonic transducer shown in fig. 3.

Fig. 6 is a view showing a region where the piezoelectric element and the supporting member overlap in the thickness direction in the ultrasonic transducer shown in fig. 3.

Fig. 7 is a diagram showing an outline of a step of connecting an electric signal line to the 1 st terminal.

Fig. 8 is a cross-sectional view showing a part of a catheter for image diagnosis including an ultrasonic transducer according to an embodiment of the present invention.

Detailed Description

Hereinafter, embodiments of the ultrasonic transducer according to the present invention will be described with reference to the drawings. The same reference numerals are given to the same components and portions in the drawings.

First, an example of an image diagnostic apparatus to which the ultrasonic transducer of the present invention can be applied will be described. Fig. 1 is a diagram showing an image diagnostic apparatus 100 including an ultrasonic transducer 11 according to an embodiment.

The image diagnostic apparatus 100 includes a catheter 110 for image diagnosis and an external device 120. Fig. 1 shows a state in which the image diagnostic catheter 110 is connected to the external device 120. Fig. 2 is a cross-sectional view showing a cross section parallel to the longitudinal direction a at the distal end of the catheter for image diagnosis 110. Fig. 3 is a diagram showing the ultrasonic transducer 11. In fig. 3, for convenience of explanation, the position of the electric signal line 14 connected to the ultrasonic transducer 11 is indicated by a two-dot chain line. Fig. 4 is a view showing the back surface of the piezoelectric element 1 in the ultrasonic transducer 11 shown in fig. 3. Fig. 5 is an exploded perspective view of the ultrasonic transducer 11 shown in fig. 3. In fig. 5, for convenience of explanation, the position of the electric signal line 14 connected to the ultrasonic transducer 11 is indicated by a two-dot chain line. In fig. 5, for convenience of explanation, the positions of the back electrode layer 5b of the 1 st electrode 5 and the 2 nd electrode 6 of the piezoelectric element 1 are indicated by broken lines. Fig. 6 is a diagram showing a region where the piezoelectric element 1 and the support member 2 overlap in the thickness direction B in the ultrasonic transducer 11 shown in fig. 3.

< catheter for image diagnosis 110 >

The catheter for image diagnosis 110 is suitable for Intravascular Ultrasound (IVUS). As shown in fig. 1, the catheter for diagnostic imaging 110 is driven by being connected to an external device 120. More specifically, the catheter for image diagnosis 110 of the present embodiment is connected to the driving unit 120a of the external device 120.

Hereinafter, for convenience of explanation, in the image diagnosis catheter 110, a side inserted into a living body in the longitudinal direction a of the image diagnosis catheter 110 is referred to as a "distal side", and an opposite side thereof is referred to as a "proximal side". The direction from the proximal end side to the distal end side of the catheter for image diagnosis 110 may be simply referred to as "insertion direction a 1". The direction from the distal end side to the proximal end side of the catheter for diagnostic imaging 110 may be simply referred to as "the extraction direction a 2".

As shown in fig. 1, the catheter for image diagnosis 110 includes an insertion portion 110a and an operation portion 110 b. The insertion portion 110a is a portion of the catheter 110 for image diagnosis that is inserted into a living body and used. The operation unit 110b is a site of the catheter 110 for image diagnosis that is operated outside the living body in a state where the insertion unit 110a is inserted into the living body. In the catheter 110 for diagnostic imaging of the present embodiment, a portion closer to the distal end side than a distal end side connector 42 (see fig. 1) described later is an insertion portion 110a, and a portion closer to the proximal end side than the distal end side connector 42 is an operation portion 110 b.

As shown in fig. 1 and 2, the insertion portion 110a includes the ultrasonic probe 10 and the sheath 20.

As shown in fig. 1, the operating portion 110b has an inner tube member 30 and an outer tube member 40. The inner tube member 30 holds the end portion on the proximal end side of the ultrasonic probe 10. The outer tube member 40 holds the end portion on the base end side of the sheath 20. As will be described in detail later, the inner tube member 30 moves in the central axis direction inside the outer tube member 40, and the ultrasonic probe 10 can move in the longitudinal direction a inside the sheath 20. Although described in detail later, the drive shaft 13 and the electric signal line 14, which are part of the ultrasonic probe 10, extend not only in the region of the insertion portion 110a but also in the region of the operation portion 110b in the longitudinal direction a by passing through the inside of the inner tube member 30 and the outer tube member 40. That is, the operation portion 110b of the present embodiment is constituted by a part of the ultrasonic probe 10 in addition to the inner tube member 30 and the outer tube member 40.

[ ultrasonic Probe 10]

As shown in fig. 2, the ultrasonic probe 10 includes an ultrasonic transducer 11, a housing 12, a drive shaft 13, and an electric signal line 14.

As shown in fig. 3, the ultrasonic transducer 11 includes a piezoelectric element 1, a support member 2, and an acoustic matching member 3. Specifically, the piezoelectric element 1 is composed of a flat piezoelectric body 4, a1 st electrode 5 laminated on at least one side in the thickness direction B of the piezoelectric body 4; and a2 nd electrode 6 laminated on at least the other side in the thickness direction B of the piezoelectric body 4. Hereinafter, for convenience of explanation, a side in the thickness direction B of the piezoelectric body 4 where at least a part of the 1 st electrode 5 is provided is referred to as "the surface side of the piezoelectric element 1". For convenience of explanation, the other side in the thickness direction B of the piezoelectric body 4 where at least a part of the 2 nd electrode 6 is provided is referred to as "the back side of the piezoelectric element 1". The front side of the piezoelectric element 1 is a side on which ultrasonic transmission and reception are performed. The back surface side of the piezoelectric element 1 is opposite to the side on which ultrasonic waves are transmitted and received.

The piezoelectric body 4 of the piezoelectric element 1 is formed of, for example, a piezoelectric ceramic sheet. Examples of the material of the piezoelectric ceramic sheet include piezoelectric ceramic materials such as lead zirconate titanate (PZT) and lithium niobate. The piezoelectric body 4 may be made of crystal instead of a piezoelectric ceramic material.

The 1 st electrode 5 and the 2 nd electrode 6 of the piezoelectric element 1 can be formed by, for example, ion plating, vapor deposition, or sputtering using a mask material as electrode layers on both surfaces in the thickness direction B of the piezoelectric body 4. Examples of the material of the 1 st electrode 5 and the 2 nd electrode 6 include metals such as silver, chromium, copper, nickel, and gold, and a laminate of these metals.

As shown in fig. 3 and 4, the 2 nd electrode 6 of the present embodiment is formed only on the back surface side of the piezoelectric element 1.

On the other hand, as shown in fig. 3 and 4, the 1 st electrode 5 of the present embodiment is formed of a folded electrode. Specifically, the 1 st electrode 5 of the present embodiment includes a front surface electrode layer 5a, a back surface electrode layer 5b, and a conductive connection portion 5 c. The surface electrode layer 5a is located on the surface side of the piezoelectric element 1. The back electrode layer 5b is located on the back surface side of the piezoelectric element 1. The connecting conductive portion 5c connects the front surface electrode layer 5a and the back surface electrode layer 5 b. In other words, the 1 st electrode 5 of the present embodiment is formed in a range from the front surface side to the back surface side of the piezoelectric element 1. By using the 1 st electrode 5 as a folded electrode, the back electrode layer 5b of the 1 st electrode 5 and the 2 nd electrode 6 can be arranged on the back surface side of the piezoelectric element 1. Thus, as compared with the case where the 1 st electrode and the 2 nd electrode are respectively disposed only on different surfaces of the piezoelectric element, the connection operation between the electric signal line 14 and the 1 st electrode 5 and the 2 nd electrode 6 can be performed only on one surface side of the piezoelectric element 1.

As shown in fig. 6, the piezoelectric element 1 includes a1 st portion 1a including a portion overlapping with a1 st terminal 7 and a portion overlapping with a2 nd terminal 8 of the support member 2, which will be described later, in the thickness direction B, and a2 nd portion 1B excluding the 1 st portion 1a in the thickness direction B. The details will be described later.

As shown in fig. 6, when the ultrasonic transducer 11 is viewed in a plan view in the thickness direction B, the outer shape of the piezoelectric element 1 is preferably square as in the present embodiment, rather than rectangular. By doing so, the straightness of the ultrasonic wave can be improved. Therefore, as shown in fig. 6, the piezoelectric element 1 is preferably made to have substantially the same length in the vertical direction (vertical direction in fig. 6) and in the horizontal direction (horizontal direction in fig. 6). In the case of a small ultrasonic transducer 11 used in a blood vessel, it is preferable to increase the ultrasonic output. Therefore, it is preferable to ensure a large size of the 2 nd part 1b, which is a main vibration part of the piezoelectric element 1. In view of the above, the piezoelectric element 1 preferably has a square outer shape in a plan view shown in fig. 6, and the area of the 2 nd portion 1b of the piezoelectric element 1 is larger than the area of the 1 st portion 1a of the piezoelectric element 1.

As shown in fig. 3, the support member 2 supports the piezoelectric element 1. As shown in fig. 3 and 5, the support member 2 has a1 st terminal 7 connected to the 1 st electrode 5 of the piezoelectric element 1 and a2 nd terminal 8 connected to the 2 nd electrode 6 of the piezoelectric element 1. As shown in fig. 3, the 1 st terminal 7 and the 2 nd terminal 8 have portions that do not overlap with the piezoelectric element 1 in the thickness direction B. By having the 1 st terminal 7 and the 2 nd terminal 8, the electrical contact between the 1 st electrode 5 and the 2 nd electrode 6 of the piezoelectric element 1 can be led out to the outside of the piezoelectric element 1. Therefore, even when it is difficult to directly connect the electric signal line 14 to the 1 st electrode 5 and the 2 nd electrode 6 of the piezoelectric element 1, for example, in the piezoelectric element 1 which is miniaturized, the electric signal line 14 is easily electrically connected to the piezoelectric element 1 by the 1 st terminal 7 and the 2 nd terminal 8.

As shown in fig. 3, the support member 2 of the present embodiment supports the piezoelectric element 1 from the back surface side of the piezoelectric element 1. In other words, the support member 2 is laminated on the back surface side of the piezoelectric element 1 so as to cover the back surface side of the piezoelectric element 1.

Examples of the material of the 1 st terminal 7 and the 2 nd terminal 8 include metals such as silver, chromium, copper, nickel, and gold, and a laminate of these metals.

More specifically, the support member 2 of the present embodiment includes a support main body portion 9 laminated on the back surface side of the piezoelectric element 1. The support body 9 covers at least the entire area of the back surface side of the piezoelectric body 4 of the piezoelectric element 1. The support main body 9 of the present embodiment covers the entire area of the back surface side of the piezoelectric element 1. More specifically, the support main body 9 of the present embodiment extends to a position outside the piezoelectric element 1 in a direction C (hereinafter referred to as an "in-plane direction C") orthogonal to the thickness direction B of the piezoelectric element 1. The 1 st terminal 7 and the 2 nd terminal 8 of the present embodiment are supported by the support body 9.

The support body 9 of the support member 2 is a sound absorber made of, for example, rubber, epoxy resin in which metal powder such as tungsten powder is dispersed, or the like. The support body 9 of the support member 2 can absorb ultrasonic waves from the piezoelectric element 1, which become noise. That is, the support member 2 of the present embodiment constitutes a sound absorbing layer that absorbs the ultrasonic waves of the piezoelectric element 1.

The sound absorbing layer as the support member 2 can be formed by a method of arranging the 1 st terminal 7 and the 2 nd terminal 8 in advance on a sheet forming the support main body portion 9 and bonding the sheet to the piezoelectric element 1. The 1 st terminal 7 and the 2 nd terminal 8 may be formed by laminating a sheet material forming the support main body portion 9 by an ion plating method, an evaporation method, or a sputtering method using a mask material, for example, and the manufacturing method thereof is not particularly limited. The terminal members forming the 1 st and 2 nd terminals 7 and 8 may be bonded to the support main body 9 by adhesion or the like.

As shown in fig. 3 to 5, the 1 st terminal 7 of the present embodiment is connected to the back electrode layer 5b of the 1 st electrode 5 between the piezoelectric element 1 and the support main body portion 9. In other words, the piezoelectric element 1 and the support member 2 of the present embodiment are stacked such that the back electrode layer 5b of the 1 st electrode 5 faces the 1 st terminal 7. The 1 st terminal 7 of the present embodiment extends from a position between the piezoelectric element 1 and the support main body 9 to a position outside the piezoelectric element 1 in the in-plane direction C. In other words, the 1 st terminal 7 is drawn out to a position not overlapping with the piezoelectric element 1 in the thickness direction B on a surface on the piezoelectric element 1 side in the thickness direction B of the support body 9 (hereinafter referred to as "upper surface of the support body 9").

As shown in fig. 3 to 5, the 2 nd terminal 8 of the present embodiment is connected to the 2 nd electrode 6 between the piezoelectric element 1 and the support main body 9. In other words, the piezoelectric element 1 and the support member 2 of the present embodiment are stacked such that the 2 nd electrode 6 and the 2 nd terminal 8 face each other. The 2 nd terminal 8 of the present embodiment extends from a position between the piezoelectric element 1 and the support main body portion 9 to a position outside the piezoelectric element 1 in the in-plane direction C. In other words, the 2 nd terminal 8 is drawn out on the upper surface of the support main body portion 9 to a position not overlapping with the piezoelectric element 1 in the thickness direction B.

In this way, the 1 st electrode 5 and the 2 nd electrode 6 of the piezoelectric element 1 are connected to the 1 st terminal 7 and the 2 nd terminal 8 of the support member 2 on the back surface side of the piezoelectric element 1. Therefore, it is sufficient that no connection portion of the electric signal line 14 is secured on the front surface side of the piezoelectric element 1 that transmits and receives ultrasonic waves, and when the electric signal line 14 is connected, it is possible to suppress damage to the portion of the ultrasonic transducer 11 on the front surface side of the piezoelectric element 1 that transmits and receives ultrasonic waves. Further, the 1 st terminal 7 and the 2 nd terminal 8 are extended from the position between the piezoelectric element 1 and the support main body portion 9 to the position outside the piezoelectric element 1 in the in-plane direction C, whereby the 1 st terminal 7 and the 2 nd terminal 8 are brought into a state of being visually recognizable from the front surface side of the piezoelectric element 1. Therefore, the work of connecting the electric signal line 14 to the 1 st terminal 7 and the 2 nd terminal 8 can be performed while monitoring the connection portion visually or the like. This can suppress the occurrence of defective products due to connection failure.

The 1 st terminal 7 and the 2 nd terminal 8 according to the present embodiment are drawn out from the position overlapping the piezoelectric element 1 in the thickness direction B toward the proximal end side in the longitudinal direction a in the catheter for image diagnosis 110. Therefore, the 1 st terminal 7 and the 2 nd terminal 8 of the present embodiment are provided on the base end side of the piezoelectric element 1 at the portions that do not overlap with the piezoelectric element 1 in the thickness direction B. As a result, as shown in fig. 2, the 1 st terminal 7 and the 2 nd terminal 8 according to the present embodiment can be easily connected to the distal end portion 14a of the electric signal line 14 extending from the distal end of the drive shaft 13 into the housing 12.

As shown in fig. 3, the 1 st terminal 7 and the 2 nd terminal 8 of the present embodiment extend to the peripheral edge of the support member 2 in the in-plane direction C. More specifically, the 1 st terminal 7 and the 2 nd terminal 8 of the present embodiment extend to positions flush with the end surfaces of the support main body portion 9 in the in-plane direction C. By doing so, the electrical signal line 14 can be more easily connected to the 1 st terminal 7 and the 2 nd terminal 8 from the outside of the ultrasonic transducer 11.

In the support member 2 of the present embodiment, two grooves 9a are defined in the upper surface of the support main body 9 facing the back surface of the piezoelectric element 1. The groove portion 9a of the present embodiment has a rectangular cross section, but may have other cross-sectional shapes such as a V-shape and an arc shape. The 1 st terminal 7 and the 2 nd terminal 8 of the present embodiment are disposed in the groove portion 9a of the support main body portion 9. The upper surface of the 1 st terminal 7 and the upper surface of the 2 nd terminal 8 facing the back surface of the piezoelectric element 1 are arranged so as to be flush with the upper surface of the support main body 9. Thus, by laminating the piezoelectric element 1 and the support member 2, the 1 st electrode 5 and the 2 nd electrode 6 of the piezoelectric element 1 can be brought into contact with the 1 st terminal 7 and the 2 nd terminal 8 of the support member 2, and the positional stability on the support member 2 of the piezoelectric element 1 can be improved. The 1 st electrode 5 and the 2 nd electrode 6 of the piezoelectric element 1 and the 1 st terminal 7 and the 2 nd terminal 8 of the support member 2 are connected by using a conductive adhesive or the like.

However, the upper surface of the 1 st terminal 7 and the upper surface of the 2 nd terminal 8 facing the back surface of the piezoelectric element 1 may be disposed in the groove 9a without protruding from the upper surface of the support body 9. In this case, the space between the 1 st electrode 5 and the 2 nd electrode 6 of the piezoelectric element 1 and the 1 st terminal 7 and the 2 nd terminal 8 of the support member 2 may be filled with the conductive material such as the above-described conductive adhesive. By doing so, the same effects as those obtained by making the upper surface of the 1 st terminal 7, the upper surface of the 2 nd terminal 8, and the upper surface of the support main body portion 9 one surface can be obtained.

As shown in fig. 3 and 5, the 1 st terminal 7 of the present embodiment defines a groove 7a for accommodating the electrical signal line 14. The 1 st terminal 7 defines the groove portion 7a, and the electric signal line 14 can be connected to the 1 st terminal 7 with the electric signal line 14 positioned in the groove portion 7 a. Therefore, the efficiency of the connection work between the electric signal line 14 and the 1 st terminal 7 is improved.

As shown in fig. 3 and 5, the 2 nd terminal 8 of the present embodiment is also divided into groove portions 8a for accommodating the electric signal lines 14. The 2 nd terminal 8 is divided into the groove portion 8a, and the electric signal line 14 can be connected to the 2 nd terminal 8 with the electric signal line 14 positioned in the groove portion 8 a. The efficiency of the connecting work between the electric signal line 14 and the 2 nd terminal 8 is improved.

In this way, by providing the groove portions (groove portions 7a and 8a in the present embodiment) in the 1 st terminal 7 and the 2 nd terminal 8, the electric signal line 14 can be easily connected to the terminals (the 1 st terminal 7 and the 2 nd terminal 8 in the present embodiment). The groove portions 7a and 8a in the present embodiment have a rectangular cross section, but may have a cross section such as a V-shape or an arc shape. The groove portions 7a and 8a preferably extend to positions flush with the end surfaces of the support main body portion 9 in the in-plane direction C. By doing so, it is easier to position the electrical signal lines 14.

Here, an example of a method of connecting the electric signal line 14 to the 1 st terminal 7 will be described. Fig. 7 is a diagram showing an outline of a process of connecting the electric signal line 14 to the 1 st terminal 7. First, a connection portion 14a made of a conductive wire with a coating material removed is formed at an end portion of the electric signal line 14. In addition, the groove portion 7a of the 1 st terminal 7 is filled with the solder paste 205. Instead of the solder paste 205, the groove 7a may be filled with a preliminary solder. In this state, the connection portion 14a of the electrical signal line 14 is disposed on the solder paste 205 filled in the groove portion 7a of the 1 st terminal 7. The solder paste 205 filled in the groove 7a may be embedded. The preliminary solder and the solder paste may be further applied so as to sandwich the connection portion 14a between the solder pastes 205. Next, the solder paste 205 and the preliminary solder are melted by heating with hot air, and the connection portion 14a is connected to the 1 st terminal 7 in the groove portion 7 a. In this way, the 1 st terminal 7 can be connected to the electric signal line 14.

Here, although the method of connecting the electric signal line 14 and the 1 st terminal 7 is shown, the same applies to the method of connecting the electric signal line 14 and the 2 nd terminal 8.

As described above, the piezoelectric element 1 includes: a1 st portion 1a composed of a portion overlapping with the 1 st terminal 7 and a portion overlapping with the 2 nd terminal 8 in the thickness direction B; and a2 nd part 1b excluding the 1 st part 1a (refer to fig. 6). As shown in fig. 6, in the present embodiment, the entire area of the back surface side of the 2 nd portion 1b of the piezoelectric element 1 is covered with the support main body portion 9. With this configuration, the support main body 9 is disposed over the entire rear surface of the 2 nd part 1b, which is the main vibration part of the piezoelectric element 1. Therefore, the ultrasonic wave from the piezoelectric element 1, which becomes noise, can be absorbed more reliably by the support main body portion 9.

As shown in fig. 3, the acoustic matching member 3 is laminated so as to cover a part of the front surface side of the piezoelectric element 1. More specifically, the acoustic matching member 3 of the present embodiment is laminated so as to cover most (for example, 80% or more) of the surface side of the 2 nd part 1b of the piezoelectric element 1, but is not limited to this configuration, and may be laminated so as to cover the entire area of the surface side of the 2 nd part 1b of the piezoelectric element 1. Further, the piezoelectric element 1 may be laminated so as to cover both the surface sides of the 1 st portion 1a and the 2 nd portion 1b, or may be laminated so as to cover the entire surface side of the piezoelectric element 1.

By providing the acoustic matching unit 3, the transmission efficiency of the ultrasonic waves to the subject can be improved. That is, the acoustic matching member 3 of the present embodiment constitutes an acoustic matching layer that improves the propagation efficiency of ultrasonic waves.

The acoustic matching layer as the acoustic matching member 3 can be formed by a method of sticking a sheet forming the acoustic matching layer to the piezoelectric element 1, a method of coating a liquid acoustic matching material forming the acoustic matching layer and curing it, or the like. Examples of the material of the acoustic matching member 3 include resin materials such as epoxy resin. The acoustic matching member 3 may be formed of a laminate of resin layers made of a resin material.

As shown in fig. 2, the case 12 accommodates the ultrasonic transducer 11 therein. The base end side of the housing 12 is connected to a drive shaft 13. The housing 12 is formed in a shape in which an opening 12a is provided in a part of a peripheral wall of a cylindrical metal tube whose both end portions in the axial direction are closed, and is formed by shaving from a metal block, MIM (metal powder injection molding), or the like.

More specifically, the case 12 of the present embodiment has a distal end wall portion 12b located on the distal end side of the opening 12 a; and a base end wall portion 12c located on the base end side of the opening 12 a. The inner space of the case 12 of the present embodiment has both axial end portions closed by the distal end wall portion 12b and the proximal end wall portion 12 c. By thus closing the case 12 at the distal end side and the proximal end side of the ultrasonic transducer 11, erroneous detection of ultrasonic waves can be suppressed, and the accuracy of image diagnosis can be improved. As shown in fig. 2, the electric signal line 14 extending inside the drive shaft 13 extends into the case 12 through the base end wall portion 12 c.

The drive shaft 13 is formed of a flexible tube. An electric signal line 14 connected to the ultrasonic transducer 11 is disposed inside the drive shaft 13. The drive shaft 13 is constituted by, for example, a plurality of layers of coils having different winding directions around the shaft. Examples of the material of the coil include stainless steel and Ni — Ti (nickel titanium) alloy. By providing the drive shaft 13 as described above, even if the two electric signal lines 14 are formed of twisted pairs having a double helix shape, the shielding property can be improved and the influence of noise generated from the electric signal lines 14 can be reduced.

The drive shaft 13 extends from the inside of the inner tube member 30 and the outer tube member 40 to a later-described stem 32 located at the base end of the inner tube member 30. That is, the drive shaft 13 extends from the distal end portion of the insertion portion 110a to the proximal end portion of the operation portion 110b in the longitudinal direction a.

As shown in fig. 2, the electric signal line 14 extends inside the drive shaft 13 to electrically connect the ultrasonic transducer 11 and the external device 120. That is, the electric signal line 14 extends from the distal end portion of the insertion portion 110a to the proximal end portion of the operation portion 110b in the longitudinal direction a, similarly to the drive shaft 13. A plurality of (two in the present embodiment) electrical signal lines 14 are provided, and each electrical signal line 14 is connected to the 1 st electrode 5 or the 2 nd electrode 6 of the piezoelectric element 1 via the 1 st terminal 7 or the 2 nd terminal 8 of the support member 2. The plurality of electrical signal lines 14 are formed of, for example, twisted pairs obtained by twisting two electrical signal lines 14. Each of the electric signal lines 14 may be a flexible thin wire member having an outer diameter larger than 0mm and not larger than 0.1 mm. Each of the electric signal lines 14 may be composed of a conductive wire having a diameter larger than 0mm and not larger than 0.05mm, and a covering material formed of an insulating material and covering the periphery of the conductive wire. The electric signal line 14 is connected to the piezoelectric element 1 through a connection portion 14a (see fig. 3 and 5) formed of a lead wire exposed by removing the coating material.

In the present embodiment, the connection portion 14a of the two electrical signal lines 14 is connected to the 1 st terminal 7 and the 2 nd terminal 8 of the support member 2 using solder, conductive adhesive, or the like (see fig. 7). Thereby, the two electric signal lines 14 are electrically connected to the 1 st electrode 5 and the 2 nd electrode 6 of the piezoelectric element 1 via the 1 st terminal 7 and the 2 nd terminal 8 of the support member 2. More specifically, the two electric signal lines 14 are connected to the 1 st terminal 7 and the 2 nd terminal 8 of the support member 2 at positions closer to the distal end side than the proximal end wall portion 12c of the case 12.

[ sheath 20]

As shown in fig. 2, the sheath 20 defines a1 st hollow portion 21a and a2 nd hollow portion 21 b. The ultrasonic probe 10 is accommodated in the 1 st hollow portion 21 a. The ultrasonic probe 10 can move forward and backward in the longitudinal direction a in the first hollow portion 21 a. The guide wire W can be inserted into the 2 nd hollow portion 21 b. In the present embodiment, the tubular guide wire insertion portion 20b defining the 2 nd hollow portion 21b is parallel to the distal end portion of the tubular body portion 20a defining the 1 st hollow portion 21 a. The main body portion 20a and the guide wire insertion portion 20b can be formed by joining different tube members by heat fusion or the like, but the method is not limited to this forming method.

The main body 20a is provided with a marker 22 having X-ray contrast properties, which is made of a material that is opaque to X-rays. The guide wire insertion portion 20b is also provided with a marker 23 having X-ray contrast properties. The markers 22 and 23 can be formed of a metal coil having high X-ray impermeability, such as platinum, gold, iridium, or tungsten.

In a range in which the ultrasonic transducer 11 moves in the longitudinal direction a of the sheath 20, a window portion 24 having a higher ultrasonic wave transmittance than other portions is formed. More specifically, the window portion 24 of the present embodiment is formed in the main body portion 20a in the sheath 20.

The window portion 24 and the guide wire insertion portion 20b of the main body portion 20a are formed of a material having flexibility, and the material is not particularly limited. Examples of the constituent material include various thermoplastic elastomers such as polyethylene, styrene, polyolefin, polyurethane, polyester, polyamide, polyimide, polybutadiene, trans-polyisoprene, fluororubber, and chlorinated polyethylene, and a mixture alloy, a polymer blend, a laminate, and the like, in which one or more of these are combined, can be used.

The main body 20a has a reinforcing portion reinforced with a material having higher rigidity than the window portion 24 at a position closer to the base end side than the window portion 24. The reinforcing portion is formed by arranging a reinforcing material in which a wire made of stainless steel or the like is woven into a mesh shape on a flexible tubular member such as a resin. The tubular member is formed of the same material as the window portion 24.

Preferably, a hydrophilic lubricating coating layer that exhibits lubricity when wet is disposed on the outer surface of the sheath 20.

A communication hole 26 for communicating the inside of the 1 st hollow portion 21a with the outside is formed at the distal end portion of the body portion 20a of the sheath 20. During pretreatment, the gas in the main body 20a can be discharged through the communication hole 26.

[ inner pipe member 30 and outer pipe member 40]

As shown in fig. 1, the inner tube member 30 has an inner tube 31 and a stem 32. The inner tube 31 is inserted so as to be movable forward and backward in the outer tube member 40. The tube holder 32 is provided on the base end side of the inner tube 31.

As shown in fig. 1, the outer tube member 40 has an outer tube 41, a tip side connector 42, and a base side connector 43. The outer tube 41 is positioned radially outward of the inner tube 31, and the inner tube 31 moves forward and backward in the outer tube 41. The distal end connector 42 connects the proximal end portion of the main body portion 20a of the sheath 20 to the distal end portion of the outer tube 41. The base end connector 43 is provided at the base end portion of the outer tube 41, and is configured to accommodate the inner tube 31 in the outer tube 41.

The drive shaft 13 and the electric signal line 14 of the ultrasonic probe 10 extend to the main body 20a of the sheath 20, the outer tube member 40 connected to the proximal end side of the main body 20a, and the stem 32 located at the proximal end portion of the inner tube member 30 partially inserted into the outer tube member 40.

The ultrasonic probe 10 and the inner tube member 30 are connected to each other so as to be integrally advanced and retracted in the longitudinal direction a. Therefore, for example, if the inner tube member 30 performs an operation of pushing toward the insertion direction a1, the inner tube member 30 is pushed into the outer tube member 40 toward the insertion direction a 1. When the inner tube member 30 is pushed into the outer tube member 40 in the insertion direction a1, the ultrasonic probe 10 connected to the inner tube member 30 moves in the insertion direction a1 in the body portion 20a of the sheath 20. Conversely, if the inner pipe member 30 is pulled in the pulling direction a2, the inner pipe member 30 is pulled out in the pulling direction a2 from inside the outer pipe member 40. When the inner tube member 30 is pulled out in the pull-out direction a2 from the inside of the outer tube member 40, the ultrasonic probe 10 connected to the inner tube member 30 moves in the pull-out direction a2 inside the main body portion 20a of the sheath 20.

When the inner tube member 30 is pushed in the insertion direction a1 to the maximum, the distal end of the inner tube member 30 reaches the vicinity of the distal end-side connector 42 of the outer tube member 40. At this time, the ultrasonic transducer 11 of the ultrasonic probe 10 is positioned near the distal end of the main body portion 20a of the sheath 20.

A stopper is provided at the distal end portion of the inner tube member 30, and prevents the inner tube member 30 from flying out to a position closer to the distal end side than the outer tube member 40, and prevents the inner tube member 30 from being pulled out to the proximal end side of the outer tube member 40 when it is pulled to the proximal end side to the maximum. The stopper is not particularly limited as long as it can achieve the above-described function, and may be formed of, for example, a wall portion that abuts against the outer tube member 40 at a predetermined position in the longitudinal direction a.

A connector portion mechanically and electrically connected to the external device 120 is provided at the base end of the stem 32 of the inner tube member 30. That is, the catheter for image diagnosis 110 is mechanically and electrically connected to the external device 120 through the connector portion of the stem 32 provided in the inner tubular member 30. More specifically, the electric signal line 14 of the ultrasonic probe 10 extends from the ultrasonic transducer 11 to the connector portion of the stem 32, and electrically connects the ultrasonic transducer 11 and the external device 120 in a state where the connector portion of the stem 32 is connected to the external device 120. The reception signal in the ultrasonic transducer 11 is transmitted to the external device 120 via the connector portion of the stem 32, subjected to a predetermined process, and displayed as an image.

< external device 120 >

As shown in fig. 1, the external device 120 includes a motor 121 as a power source for rotating the drive shaft 13, and a motor 122 as a power source for moving the drive shaft 13 in the longitudinal direction a. The rotational motion of the motor 122 is converted into axial motion by a ball screw 123 connected to the motor 122.

More specifically, the external device 120 of the present embodiment includes: a drive unit 120 a; a control device 120b electrically connected to the driving unit 120a by wire or wirelessly; and a monitor 120c capable of displaying an image generated based on a reception signal received by the control device 120b from the catheter for image diagnosis 110. The motor 121, the motor 122, and the ball screw 123 of the present embodiment are provided in the drive unit 120 a. The operation of the driving unit 120a is controlled by the control device 120 b. The control device 120b can be constituted by a processor including a CPU and a memory.

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

The ultrasonic transducer of the present invention is not limited to the specific configuration specified in the above embodiment, and various modifications and changes can be made without departing from the description of the technical means. In the ultrasonic transducer 11 of the present embodiment, the 1 st electrode 5 is formed of a folded electrode, but the 1 st electrode 5 and the 2 nd electrode 6 may not be formed of folded electrodes, but may be formed by being laminated on only one surface. Instead of the 1 st electrode 5, the 2 nd electrode 6 may be formed of a folded electrode. However, as in the present embodiment, the 1 st electrode 5 is configured as a folded electrode, whereby the 1 st electrode 5 and the 2 nd electrode 6 of the piezoelectric element 1 are connected to the 1 st terminal 7 and the 2 nd terminal 8 of the support member 2 on the back surface side of the piezoelectric element 1. Therefore, as described above, it is sufficient that no connection portion of the electric signal line 14 is secured on the front surface side of the piezoelectric element 1 that transmits and receives ultrasonic waves, and when the electric signal line 14 is connected, the damage of the portion of the ultrasonic transducer 11 on the front surface side of the piezoelectric element 1 that transmits and receives ultrasonic waves can be suppressed.

The ultrasonic probe to which the ultrasonic transducer of the present invention is applicable is not limited to the configuration of the ultrasonic probe 10 described in the above embodiment. The ultrasound probe 10 of the above embodiment is configured to include only the ultrasound transducer 11 capable of intravascular ultrasound diagnosis as a core of microscopic images, but is not limited to this configuration, and may also include an Optical transceiver capable of Optical Coherence Tomography (OCT). Fig. 8 is a cross-sectional view showing a part of a catheter 410 for image diagnosis including an ultrasonic probe 310, the ultrasonic probe 310 including an ultrasonic transducer 11 and an optical transceiver 301. The ultrasonic probe 310 shown in fig. 8 is different from the ultrasonic probe 10 described above in that a configuration capable of performing optical coherence tomography is added.

Specifically, in the ultrasonic probe 310 shown in fig. 8, an optical transmission/reception unit 301 is disposed in addition to the ultrasonic transducer 11 in the housing 12. The light transmitting/receiving unit 301 continuously transmits light (measurement light) transmitted from an optical fiber cable serving as an optical signal line 302 extending inside the drive shaft 13 into the living body lumen, and continuously receives reflected light from living tissue in the living body lumen. The optical transceiver 301 transmits the received reflected light to the external device 120 (see fig. 1) via the optical signal line 302. The control device 120b (see fig. 1) of the external device 120 generates interference light data by causing the reflected light obtained by the measurement to interfere with the reference light obtained by separating the light from the light source. The controller 120b of the external device 120 generates an optical tomographic image based on the generated interference light data, and displays the optical tomographic image on the monitor 120c (see fig. 1).

As shown in fig. 8, in the driving shaft 13, a plurality of electric signal lines 14 are spirally wound around the circumference of the optical signal line 302, and the plurality of electric signal lines 14 extend in parallel with each other. More specifically, the two electrical signal lines 14 shown in fig. 8 extend in a double spiral around the optical fiber cable as the optical signal line 302 extending in the long-side direction a.

Industrial applicability

The present invention relates to an ultrasonic transducer.

Description of the reference numerals

1: piezoelectric element

1 a: part 1

1 b: section 2

2: support member

3: acoustic matching component

4: piezoelectric body

5: 1 st electrode

5 a: surface electrode layer

5 b: back electrode layer

5 c: connecting conductive part

6: 2 nd electrode

7: no. 1 terminal

7 a: trough part

8: 2 nd terminal

8 a: trough part

9: supporting body part

9 a: trough part

10. 310: ultrasonic probe

11: ultrasonic vibrator

12: shell body

12 a: opening part

12 b: tip wall portion

12 c: base end wall portion

13: drive shaft

14: electric signal wire

14 a: connecting part

20: protective sleeve

20 a: main body part

20 b: guide wire insertion part

21 a: 1 st hollow part

21 b: hollow part 2

22. 23: identification

24: window part

26: communicating hole

30: inner pipe member

31: inner pipe

32: tube holder

40: outer tube member

41: outer tube

42: top end connector

43: base end connector

100: image diagnosis apparatus

110, 410: catheter for image diagnosis

110 a: insertion part

110 b: operation part

120: external device

120 a: drive unit

120 b: control device

120 c: monitor with a display

121: electric machine

122: electric machine

123: ball screw

205: solder paste

301: light transmitting/receiving unit

302: optical signal line

A: longitudinal direction of catheter for image diagnosis

A1: direction of insertion

A2: direction of extraction

B: thickness direction of piezoelectric element

C: in-plane direction (direction orthogonal to thickness direction of piezoelectric element)

W: a guidewire.