JP2003175037A - Ultrasonic probe and ultrasonic diagnostic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simultaneously form a plurality of scanning surfaces in the direction of elevation in an ultrasonic diagnostic apparatus. <P>SOLUTION: Refraction layers 52A are respectively formed on the sides of the upper surfaces of respective piezoelectric elements 36. The refraction layers have alternately different changing action, thereby two reception beams can simultaneously be formed per single transmission. It is also possible to inclining the piezoelectric elements themselves without utilizing the refraction layers. In the case of swinging and scanning an oscillation unit 33 in the direction of elevation, the number of scanning surfaces to be formed per the unit time can be doubled. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic probe and an ultrasonic diagnostic apparatus, and more particularly to a structure of an ultrasonic probe for improving a frame rate.

[0002]

2. Description of the Related Art A general ultrasonic probe is provided with an array transducer including a plurality of vibrating elements. The ultrasonic beam is scanned in the array direction by applying electronic scanning to the array transducer. As a scanning method, electronic linear scanning, electronic sector scanning, etc. are known. Generally, one or more matching layers are formed on the upper surface side of the array transducer, and an acoustic lens is provided on the upper surface. The acoustic lens is a member for focusing the ultrasonic beam in the elevation direction orthogonal to the array direction. In the conventional ultrasonic probe, since only one scanning surface is formed by one electronic scanning, for example, when capturing echo data in a three-dimensional area, a transducer unit including an array transducer is used. It is necessary to repeatedly perform electronic scanning at each mechanical scanning position while moving in parallel or swinging (that is, performing mechanical scanning).

[0003]

However, when three-dimensional measurement is performed on an organ that moves at a relatively high speed, such as the heart, the three-dimensional image is distorted in time unless the frame rate per unit time is improved. I will end up. On the other hand, if the frame rate is improved and scanning is performed at high speed, the spatial resolution in the scanning direction is reduced. This problem also occurs when, for example, echo data on the respective scanning planes are overlapped to form an integrated image.

The present invention has been made in view of the above conventional problems, and an object thereof is to improve the frame rate when echo data is captured in a three-dimensional area.

The present invention is to form a plurality of reception beams simultaneously in the elevation direction.

[0006]

In order to achieve the above object, the present invention provides an ultrasonic probe having an array transducer including a plurality of vibrating elements, wherein the plurality of vibrating elements are divided into a plurality of groups. The transmitting and receiving directions of the vibrating elements are set to different angles in the elevation direction between the groups.

According to the above structure, the transmitting and receiving directions of the vibrating elements are set to be different in the elevation direction between the groups, so that the plurality of scanning planes can be simultaneously operated without changing the direction of the array transducer. Can be formed. For example, when the array transducer (or the transducer unit including the same) is oscillated and scanned to form a plurality of scanning planes to form a three-dimensional echo data acquisition space, according to the present invention, the unit The number of scanning planes per time can be increased, and in particular, two scanning planes can be formed at the same time, which makes it possible to form a three-dimensional data acquisition area in a short time.
Therefore, the problem of so-called time distortion and the problem of insufficient time resolution can be solved and improved.

When a group is set for a plurality of vibrating elements, different groups may be assigned alternately one by one, or groups may be assigned randomly. If the number of groups is increased, it is possible to form more reception beams with one transmission. However, if the number of vibrating elements forming one group is too small, the sensitivity and the resolution decrease,
It is necessary to set the group in consideration of it.

The present invention can be applied not only to 2D probes but also to 1.5D probes and the like. Further, it is applicable to various electronic scanning methods such as electronic sector and electronic linear.

Preferably, each of the vibration elements includes a piezoelectric element, and the piezoelectric elements are arranged between the groups with different inclination angles in the elevation direction. According to this structure, the direction of the piezoelectric element can be changed to set the ultrasonic wave transmitting / receiving direction to a desired direction. However, when the deflection angle of the ultrasonic beam is large in the case of performing the electronic sector scanning, the ultrasonic wave emitted from one vibrating element collides with the other vibrating element between two adjacent vibrating elements, or This causes a mutual interference problem in which a reflected wave that should be received by one of the vibrators collides with the other vibrator to create a shadow.

Preferably, each vibration element includes a piezoelectric element for transmitting and receiving ultrasonic waves and a refraction layer for refracting the propagation direction of the ultrasonic waves transmitted and received by the piezoelectric element, and the transmission and reception using the refraction layer. The wave direction angle is set. With this configuration, it is possible to avoid the problem of mutual interference as described above, and it is also advantageous in terms of manufacturing cost.

Preferably, the plurality of groups are wholly used to form a single transmission beam, and the groups are individually used to form a plurality of reception beams. The origins of the plurality of reception beams may or may not coincide with each other. For example, the angles of the transmission and reception directions may be different between the first group and the second group, and the centers of the vibration elements may be shifted in the elevation direction between the groups.

In order to achieve the above object, the present invention provides an ultrasonic probe having an array transducer comprising a plurality of vibrating elements, wherein the plurality of vibrating elements are divided into a plurality of groups, The vibrating element includes a piezoelectric element that transmits and receives ultrasonic waves and a refraction layer that refracts the propagation direction of the ultrasonic waves that are transmitted and received by the piezoelectric element, and the refraction action of the refraction layer differs between the groups. Is characterized by.

Preferably, the refraction layer includes a first member and a second member which are joined to each other at a boundary surface inclined with respect to the upper surface of the piezoelectric element and have different sound velocities. Here, the boundary surface is preferably a flat surface, but may be a curved surface such as a concave surface or a convex surface.

Desirably, the sound velocity in the first member and the sound velocity in the second member are different from each other, and the first member and the second member have substantially the same acoustic impedance.

(3) In order to achieve the above object,
The present invention provides an ultrasonic wave for capturing three-dimensional data, which includes a vibrator unit having an array vibrator including a plurality of vibrators, and a mechanical scanning mechanism that mechanically scans the vibrator unit in the elevation direction. In the probe, the plurality of vibrating elements are divided into a plurality of groups, and the transmitting and receiving directions of the vibrating elements are set to different angles in the elevation direction between the groups.

As described above, as the means for changing the transmitting and receiving directions, a method of tilting the vibrating element itself, a method of using the refraction layer, and the like can be considered.

(4) In order to achieve the above object,
The present invention includes an ultrasonic probe including a vibrating element array composed of a plurality of vibrating element groups, and an apparatus body connected to the ultrasonic probe, and an ultrasonic wave is provided between the respective vibrating element groups. The transmitting and receiving directions of are set to different angles in the elevation direction, the device body, a transmitter for forming a transmission beam in the vibrating element array,
In the vibrating element array, a receiver for simultaneously forming a receiving beam for each of the vibrating element groups with respect to one transmitting beam is included. here,
The receiving unit may be composed of a plurality of receiving circuits.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the essential structure of an ultrasonic probe according to the present invention. Specifically, the vibrator unit 8
Is shown as a perspective view.

The ultrasonic probe for capturing three-dimensional echo data according to this embodiment is roughly classified into a vibrator unit 8 shown in FIG. 1 and a scanning mechanism (not shown) for mechanically swinging the vibrator unit 8. )), And is composed of. The vibrator unit 8 will be described in detail below.

The piezoelectric element array 12 is composed of a plurality of piezoelectric elements. In the present embodiment, the plurality of piezoelectric elements are divided into two groups, an A group and a B group. In the figure, the piezoelectric elements belonging to the A group are represented by reference numeral 10A, and the piezoelectric elements belonging to the B group. The element is represented by reference numeral 10B. The piezoelectric elements 10A and the piezoelectric elements 10B are alternately arranged vertically as shown in the figure. In this embodiment, two groups are set, but of course, three or more groups may be set.

As shown in FIG. 1, each piezoelectric element 10A
1 are arranged in an inclined state in which one end side is raised and the other end side is lowered in FIG. On the other hand, each piezoelectric element 10B
Contrary to the piezoelectric element 10A, are arranged in an inclined state in which the other end is raised and one end is lowered. The reason why the piezoelectric elements 10A or 10B are arranged so as to be inclined in this way is to make the directions of transmission and reception of ultrasonic waves different among the groups. Specifically, in the drawing, Y
In the elevation direction shown as the direction, the ultrasonic wave transmission / reception direction is different for each group. Each piezoelectric element is made of a member such as PZT, and ultrasonic waves are transmitted and received by each piezoelectric element.

The first matching layer array 16 is composed of a plurality of first matching layers. Specifically, a plurality of first matching layers are divided into two groups, an A group and a B group, reference numeral 14A indicates a first matching layer belonging to the A group, and reference numeral 14B indicates a first matching layer belonging to the B group. The matching layer is shown. That is, the first matching layer 14A is located on the upper surface side of the piezoelectric element 10A, and the first matching layer 14B is located on the upper surface side of the piezoelectric element 10B.

Further, in the present embodiment, the second matching layer array 20 is composed of a plurality of second matching layers, and the plurality of second matching layers are divided into A group and B group.
It is divided into two groups. In FIG. 1, reference numeral 1
Reference numeral 18 indicates a second matching layer belonging to the A group,
B indicates the second matching layer belonging to the B group. Second
The matching layer 18A is located on the upper surface side of the first matching layer 14A, and the second matching layer 18B is located on the upper surface side of the first matching layer 14B.

Therefore, a plurality of laminated bodies (vibration elements) are arranged and arranged along the array direction which is the X direction, but they are divided into two groups, that is, the laminated body 22 is A. Belong to the group, the stack 24 is B
Belong to a group. As shown in FIG. 1, each laminated body 2
In Nos. 2 and 24, the first matching layer and the second matching layer are also inclined according to the inclination of the vibrating element.

An acoustic lens 32 is provided on the upper surface side of the second matching layer array 20, and a backing layer 30 is provided on the lower surface side of the piezoelectric element array 12. The lower surface side of the acoustic lens 32 has a shape that matches the upper surface side shape of the second matching layer array 20, and the upper surface side of the backing layer 30 has a shape that matches the lower surface side shape of the piezoelectric element array 12. There is.

Incidentally, although a groove is formed between the laminates 22 and 24, it is not shown in FIG.

According to the embodiment shown in FIG. 1, as described above, since the piezoelectric elements are provided in an inclined manner for each group, the ultrasonic wave transmitting / receiving directions in the elevation direction are different according to the inclination. For example, it is possible to simultaneously form two receiving beams having different angles in the elevation direction per one transmitting beam. By the way, when forming a transmit beam,
Ultrasonic waves are transmitted by the vibration elements of all groups.

Therefore, if the transducer unit 8 as shown in FIG. 1 is translated or rocked in the elevation direction, the number of scanning planes formed per unit time can be doubled as compared with the conventional case. Therefore, if the size of the three-dimensional data acquisition space is the same, the time required for the acquisition can be halved as compared with the conventional case.

In FIG. 1, the first matching layer array 1
6 and the second matching layer array 20 are provided, the two matching layer arrays do not necessarily have to be provided, and one matching layer array is provided between the acoustic lens and the piezoelectric element array 12. May be acoustically matched.

FIG. 2 shows a vibration element unit 33 according to another embodiment as a perspective view.

The piezoelectric element array 34, like the conventional piezoelectric element array, includes a plurality of horizontally arranged piezoelectric elements 3.
It is composed of six. A first matching layer array 38 and a second matching layer array 42 are provided on the upper surface side of the piezoelectric element array 34 as in the conventional case. Each first matching layer 4
0 and each second matching layer 44 are horizontally arranged.

In this embodiment, the refraction layer array 46 is provided on the upper surface side of the second matching layer array 42. The refraction layer array 46 is composed of a plurality of refraction layers, and these refraction layers alternately form the A group and the B group. In FIG. 2, a refraction layer 52A forming the A group is shown, and the refraction layer 52A is composed of a first member 48A and a second member 50A as described later in detail. This is the refraction layer 5 belonging to the B group.
The same applies to 2B (described later). Refractive layer array 46
The acoustic lens 56 is provided on the upper surface side of the piezoelectric element array 34, and the backing layer 54 is provided on the lower surface side of the piezoelectric element array 34.

As shown, the piezoelectric element 36, the first matching layer 40, the second matching layer 44, and the refractive layer 52A or 52B.
One laminated body (vibration element) is configured by
Each laminated body belongs to the A group and the B group alternately.

3 and 4 are sectional views of the vibrator unit 33 shown in FIG. The refraction layer 5 is shown in FIG.
2A is shown in cross section, and FIG. 4 shows the cross section of the refraction layer 52B. In FIG. 3, the refraction layer 52A includes a first member 48A provided on the upper side and a second member 48A provided on the lower side.
It is constituted by the member 50A. Here, the first member 48A and the second member 50A are made of a material that makes the sound speeds of ultrasonic waves passing therethrough different from each other,
Regarding the refraction layer 52A, the sound velocity in the first member 48A is higher than that in the second member 50A. Therefore, as shown in FIG. 3, the propagation path of the ultrasonic waves transmitted and received by the piezoelectric element 36 is inclined to the right in FIG. 3 by a predetermined angle. Of course, the acoustic lens 56 also exhibits the action of converging ultrasonic waves in the elevation direction, and the final azimuth of transmission / reception is defined by the total action of the refraction layer 52A and the action of the acoustic lens 56. By the way, the first member 48A and the second member 50
The boundary surface with A is an inclined plane as shown in the figure, but the boundary surface may be a convex surface or a concave surface. The same applies to the refraction layer 52B described below.

In FIG. 4, the refraction layer 52B is composed of a first member 48B arranged on the upper side and a 50B arranged on the lower side, in which the sound velocity of the passing ultrasonic wave is the second.
The sound speed of the first member 48B is selected to be higher than the sound speed of the member 50B. In the refraction layer 52A and the refraction layer 52B, the first
The members 48A and 48B are made of the same member, and the same applies to the second members 50A and 50B.
According to the refraction layer 52B shown in FIG. 4, as described above, it is possible to incline the propagation direction of the ultrasonic wave transmitted / received in the piezoelectric element 36 to the left in FIG. 4 by the action of the refraction layer 52B. . In the present embodiment,
Both the A group and the B group are configured to change the direction of the ultrasonic beam in the elevation direction. However, if the ultrasonic beam is deflected in at least one group, a plurality of received beams are different from each other in one transmission. It is possible to set the direction.

The acoustic impedances of the first member 48A and the second member 52A may be made substantially the same so as to prevent a decrease in the transmittance of ultrasonic waves due to the occurrence of reflection between them. The same applies to the case of the first member 48B and the second member 52B.

In FIG. 5, two receive beams 60, 62 and a transmit beam 64 are shown. In FIG. 5, the horizontal axis shows the distance in the elevation direction from the center of the piezoelectric element array, and the vertical axis shows the relative amplitude as sound pressure or sensitivity. The stack or vibrating element forming the group A forms a reception beam 60 which is deflected to the right as shown in the figure, and similarly, the stack or vibrating element forming the group B deflects to the left. The receive beam 62 can be formed. At the time of transmission, the laminated bodies of both groups, that is, the vibrating elements are all used at the same time, so that a single transmission beam 64 that combines two transmission beams is formed. Therefore, it is possible to perform two receptions per transmission and double the number of scanning planes formed per unit time, as described above.

Although so-called electronic sector scanning is applied in the present embodiment, the same vibrator unit as above is also used when electronic linear scanning or another electronic scanning method is applied. You can

Next, FIG. 6 is a block diagram showing the main configuration of the ultrasonic diagnostic apparatus according to this embodiment.

The three-dimensional data acquisition probe 80 is shown in FIG.
The vibrator unit 33 shown in FIG. The vibrator unit 33 has a piezoelectric element array composed of a plurality of piezoelectric elements, and the plurality of piezoelectric elements are divided into two groups, the A group and the B group, as described above.

The scanning mechanism 82 is a mechanical mechanism for oscillating and scanning the vibrator unit 33, and the scanning mechanism 82.
Specifically, is composed of a drive motor and a swing mechanism. A drive signal from the driver 86 is supplied to the drive motor, and the scan control unit 8 is supplied to the driver 86.
The control signal from 8 is sent. The position detector 84 is
Transducer unit 3 swingably scanned by the scanning mechanism 82
3 is a detector for detecting the rocking position of No. 3. The detection signal is output to the scan controller 88.

The scan controller 88 controls both mechanical scanning and electronic scanning, and as shown in the drawing, the driver 86.
The scanning mechanism 82 is controlled via the
A control signal is output from 8 to the transmission beamformer 70 and the reception beamformers 72 and 74.

Here, the transmission beam former 70 is a circuit that forms a transmission beam 64 as shown in FIG. 5 by supplying a transmission signal to a plurality of vibrating elements. The reception beam former 72 is a circuit that forms a reception beam by performing so-called phasing addition on a plurality of reception signals output from the piezoelectric elements forming the A group. Similarly, the reception beam former 74 is a circuit that forms a reception beam by performing phasing addition processing on a plurality of reception signals from a plurality of piezoelectric elements forming the B group. The reception signals after phasing addition output from the reception beamformers 72 and 74 are once stored in the three-dimensional echo data memory as needed, and then the reception signals are read out to form a three-dimensional image. Used for. The circuit configuration example shown in FIG. 6 is an example, and other various circuit configuration examples can be adopted.

[0046]

As described above, according to the present invention,
The frame rate can be improved when the echo data is captured in the three-dimensional area. Further, according to the present invention, it is possible to simultaneously form a plurality of reception beams in the elevation direction.

[Brief description of drawings]

FIG. 1 is a perspective view of a vibrator unit according to the present embodiment.

FIG. 2 is a perspective view of a vibrator unit according to another embodiment.

3 is a cross-sectional view of the vibrator unit shown in FIG.

4 is a cross-sectional view of the vibrator unit shown in FIG.

FIG. 5 is a diagram showing patterns of two reception beams and transmission beams.

FIG. 6 is a block diagram showing a main configuration of an ultrasonic diagnostic apparatus.

[Explanation of symbols]

8,33 transducer unit, 12 piezoelectric element array, 1
6 first matching layer array, 20 second matching layer array, 2
2,24 laminated body (vibration element), 30 backing layer,
32 Acoustic lens.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2G047 AC13 BA03 BC13 CA01 DB02                       DB03 DB14 EA09 GB02 GB23                       GB25 GB27 GB28 GB32 GF15                       GF17                 4C301 AA02 BB13 BB22 BB26 EE10                       GB04 GB20 GB21 GB27 GB40                       HH13 HH60 JB43                 4C601 BB03 BB05 BB06 BB09 BB16                       EE07 GB01 GB03 GB04 GB20                       GB24 GB32 GB50 HH14 HH22                       HH40                 5D019 AA06 BB18 FF04 GG03

Claims (9)

[Claims] 1. An ultrasonic probe having an array transducer including a plurality of vibrating elements, wherein the plurality of vibrating elements are divided into a plurality of groups, and the transmitting and receiving directions of the vibrating elements are elevated between the groups. An ultrasonic probe characterized by being set at different angles in directions. 2. The ultrasonic probe according to claim 1, wherein each of the vibration elements includes a piezoelectric element, and the piezoelectric elements are arranged at different inclination angles in the elevation direction between the groups. Ultrasonic probe. 3. The ultrasonic probe according to claim 1, wherein each of the vibration elements forming at least one of the plurality of groups is a piezoelectric element for transmitting and receiving ultrasonic waves and the piezoelectric element. An ultrasonic probe including a refraction layer that refracts a propagation direction of transmitted and received ultrasonic waves, wherein an angle of the transmission and reception direction is set by using the refraction layer. 4. The ultrasonic probe according to claim 1, wherein a single transmission beam is formed by using the plurality of groups as a whole, and a plurality of groups are individually used by each of the groups. An ultrasonic probe characterized in that a reception beam is formed. 5. An ultrasonic probe having an array transducer composed of a plurality of vibrating elements, wherein the plurality of vibrating elements are divided into a plurality of groups, and each of the vibrating elements transmits and receives ultrasonic waves. An ultrasonic probe comprising an element and a refraction layer for refracting a propagation direction of ultrasonic waves transmitted and received by the piezoelectric element, wherein refraction of the refraction layer is different between the respective groups. 6. The ultrasonic probe according to claim 5, wherein the refraction layer is joined to each other at a boundary surface inclined with respect to an upper surface of the piezoelectric element, and has a different sound velocity. An ultrasonic probe including a second member. 7. The ultrasonic probe according to claim 6, wherein the first member and the second member have substantially the same acoustic impedance. 8. An ultrasonic transducer for three-dimensional data acquisition, comprising: a vibrator unit having an array vibrator made of a plurality of vibrators; and a mechanical scanning mechanism for mechanically scanning the vibrator unit in the elevation direction. In the acoustic wave probe, the plurality of vibrating elements are divided into a plurality of groups, and the transmitting and receiving directions of the vibrating elements are set to different angles in the elevation direction between the groups. Tentacles. 9. An ultrasonic probe including a vibrating element array including a plurality of vibrating element groups, and an apparatus main body connected to the ultrasonic probe, wherein: The transmitting and receiving directions of the sound waves are set to different angles in the elevation direction, and the apparatus body includes a transmitter for forming a transmission beam in the vibrating element array, and the transmitting unit for one transmitting beam in the vibrating element array. An ultrasonic diagnostic apparatus comprising: a receiver for simultaneously forming a reception beam for each transducer element group.