JP3660903B2 - Ultrasonic probe and ultrasonic diagnostic apparatus - Google Patents

Description

[0001]
BACKGROUND 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]
[Prior art]
A general ultrasonic probe is provided with an array transducer including a plurality of transducer elements. By applying electronic scanning to the array transducer, the ultrasonic beam is scanned in the array direction. As scanning methods, electronic linear scanning, electronic sector scanning, and the like are known. Generally, one or a plurality of 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, only one scanning plane is formed by one electronic scanning. For example, when echo data is captured in a three-dimensional region, a transducer unit including an array transducer is provided. It is necessary to repeatedly perform electronic scanning at each mechanical scanning position while moving or swinging (that is, performing mechanical scanning).
[0003]
[Problems to be solved by the invention]
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 temporally distorted unless the frame rate per unit time is improved. On the other hand, when the frame rate is increased and scanning is performed at a high speed, the spatial resolution in the scanning direction is lowered. This problem also occurs when, for example, an integrated image is formed by superimposing echo data on each scanning plane.
[0004]
The present invention has been made in view of the above-described conventional problems, and an object thereof is to improve the frame rate when echo data is captured in a three-dimensional region.
[0005]
The present invention is to simultaneously form a plurality of reception beams in the elevation direction.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides an ultrasonic probe having an array transducer composed of a plurality of vibration elements, wherein the plurality of vibration elements are divided into a plurality of groups, and the vibration elements are arranged between the groups. The transmission / reception directions are set at different angles in the elevation direction.
[0007]
According to the above configuration, since the transmission / reception directions of the vibration elements are set to be different in the elevation direction between the groups, a plurality of scanning planes are formed at the same time without changing the orientation of the array transducer. It becomes possible. For example, according to the present invention, when a plurality of scanning planes are formed to form a three-dimensional echo data capturing space while swinging and scanning an array transducer (or a transducer unit including the array transducer), 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, thereby forming a three-dimensional data capturing area in a short time. Therefore, the so-called time distortion problem and insufficient time resolution problem can be solved and improved.
[0008]
When group setting is performed for a plurality of vibration elements, different groups may be alternately assigned one by one, or groups may be randomly assigned. If the number of groups is increased, more reception beams can be formed in one transmission. However, if the number of vibration elements constituting one group is too small, the sensitivity and resolution are lowered, and therefore it is necessary to set the group in consideration of this.
[0009]
The present invention can be applied to 1.5D probes in addition to 2D probes. Further, the present invention can be applied to various electronic scanning methods such as an electronic sector and an electronic linear.
[0010]
Preferably, 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. According to this configuration, it is possible to set the ultrasonic wave transmission / reception direction to a desired direction by changing the direction of the piezoelectric element. However, when the deflection angle of the ultrasonic beam is large when performing electronic sector scanning, the ultrasonic wave radiated from one vibration element collides with the other vibration element between two adjacent vibration elements, or There arises a problem of mutual interference in which a reflected wave to be received by one vibrator collides with the other vibrator to be shaded.
[0011]
Preferably, each vibration element includes a piezoelectric element that transmits / receives ultrasonic waves and a refraction layer that refracts the propagation direction of ultrasonic waves transmitted / received by the piezoelectric elements, and uses the refraction layer to change the transmission / reception direction. An angle is set. According to this configuration, it is possible to avoid the problem of mutual interference as described above, and it is advantageous in terms of manufacturing cost.
[0012]
Preferably, the plurality of groups are used as a whole to form a single transmission beam, and each group is individually used to form a plurality of reception beams. Note that the starting points of the plurality of reception beams may or may not coincide with each other. For example, in the first group and the second group, the angles in the transmission / reception direction may be different from each other, and the center of the vibration element may be shifted in the elevation direction between the groups.
[0013]
In order to achieve the above object, the present invention provides an ultrasonic probe having an array transducer composed of a plurality of transducer elements, wherein the plurality of transducer elements are divided into a plurality of groups, A piezoelectric element that transmits and receives ultrasonic waves and a refractive layer that refracts the propagation direction of ultrasonic waves transmitted and received by the piezoelectric element, and the refractive action of the refractive layer differs between the groups. To do.
[0014]
Preferably, the refractive layer includes a first member and a second member that are bonded to each other at an interface inclined with respect to the upper surface of the piezoelectric element and have different sound speeds. Here, the boundary surface is preferably a flat surface, but may be a curved surface such as a concave surface or a convex surface.
[0015]
Preferably, the speed of sound in the first member and the speed of sound in the second member are different from each other, and the first member and the second member have substantially the same acoustic impedance.
[0016]
(3) In order to achieve the above object, the present invention includes a transducer unit having an array transducer including a plurality of transducer elements, and a mechanical scanning mechanism that mechanically scans the transducer unit in the elevation direction. In the ultrasonic probe for taking in three-dimensional data including, the plurality of vibration elements are divided into a plurality of groups, and the transmission / reception direction of the vibration elements differs in the elevation direction between the groups. It is characterized by being set to.
[0017]
As described above, as a means for changing the transmission / reception direction, a method of tilting the vibration element itself, a method of using a refractive layer, and the like can be considered.
[0018]
(4) In order to achieve the above object, the present invention includes an ultrasonic probe including a vibration element array composed of a plurality of vibration element groups, a device main body connected to the ultrasonic probe, Between the vibration element groups, the ultrasonic wave transmission / reception direction is set to an angle different in the elevation direction, and the apparatus body includes a transmission unit for forming a transmission beam in the vibration element array; and And a receiving unit for simultaneously forming a receiving beam for each of the vibrating element groups with respect to one transmitting beam in the vibrating element array. Here, the receiving unit may be configured by a plurality of receiving circuits.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.
[0020]
FIG. 1 shows a main configuration of an ultrasonic probe according to the present invention. Specifically, the vibrator unit 8 is shown as a perspective view.
[0021]
The ultrasonic probe for taking in three-dimensional echo data according to the present embodiment is roughly divided into a transducer unit 8 shown in FIG. 1 and a scanning mechanism (not shown) that mechanically swings the transducer unit. , Is composed of. Hereinafter, the vibrator unit 8 will be described in detail.
[0022]
The piezoelectric element array 12 is composed of a plurality of piezoelectric elements. The plurality of piezoelectric elements are divided into two groups of A group and B group in this embodiment. 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 up and down as illustrated. In this embodiment, two groups are set. Of course, three or more groups may be set.
[0023]
As shown in FIG. 1, the piezoelectric elements 10A are arranged in an inclined state in which one end side is lifted and the other end side is lowered in FIG. On the other hand, the piezoelectric elements 10B are arranged in an inclined state in which the other end side is lifted and the one end side is lowered, contrary to the piezoelectric element 10A. The reason why the piezoelectric elements 10A or 10B are arranged in an inclined manner is to change the direction of transmission / reception of ultrasonic waves between the groups, and specifically, the elevation direction shown as the Y direction in the figure. In FIG. 5, the ultrasonic wave transmission / reception direction is different for each group. Each piezoelectric element is formed of a member such as PZT, and ultrasonic waves are transmitted and received in each piezoelectric element.
[0024]
The first matching layer array 16 includes a plurality of first matching layers. Specifically, a plurality of first matching layers are divided into two groups of A group and B group, reference numeral 14A denotes a first matching layer belonging to the A group, and reference numeral 14B denotes a first matching member 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.
[0025]
Further, in the present embodiment, the second matching layer array 20 is constituted by a plurality of second matching layers, and the plurality of second matching layers are divided into two groups of A group and B group. In FIG. 1, reference numeral 18A denotes a second matching layer belonging to the A group, and reference numeral 18B denotes a second matching layer belonging to the B group. The second 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.
[0026]
Accordingly, a plurality of stacked bodies (vibrating elements) are arranged in alignment along the array direction that is the X direction, but they are divided into two groups, that is, the stacked body 22 belongs to the A group. The laminate 24 belongs to the B group. As shown in FIG. 1, in each of the stacked bodies 22 and 24, the first matching layer and the second matching layer are also inclined according to the inclination of the vibration element.
[0027]
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 shape of the upper surface side of the second matching layer array 20, and the upper surface side of the backing layer 30 has a shape that matches the shape of the lower surface side of the piezoelectric element array 12. Yes.
[0028]
Incidentally, although a groove is formed between the stacked bodies 22 and 24, it is not shown in FIG.
[0029]
According to the embodiment shown in FIG. 1, as described above, since the piezoelectric element is inclined for each group, the ultrasonic wave transmission / reception direction in the elevation direction can be varied according to the inclination. For example, it is possible to simultaneously form two reception beams having different angles in the elevation direction per transmission beam. Incidentally, when a transmission beam is formed, ultrasonic waves are transmitted by the vibration elements of all groups.
[0030]
Therefore, if the transducer unit 8 as shown in FIG. 1 is translated or oscillated and scanned in the elevation direction, the number of scanning surfaces formed per unit time can be doubled compared to the conventional case. Thus, if the size of the three-dimensional data acquisition space is the same, the time required for the acquisition can be halved compared to the conventional method.
[0031]
In FIG. 1, two matching layers of the first matching layer array 16 and the second matching layer array 20 are provided. However, two matching layer arrays are not necessarily provided, and one matching layer array is provided. Thus, acoustic matching between the acoustic lens and the piezoelectric element array 12 may be achieved.
[0032]
FIG. 2 is a perspective view of a vibration element unit 33 according to another embodiment.
[0033]
The piezoelectric element array 34 is composed of a plurality of piezoelectric elements 36 that are horizontally arranged in the same manner as a conventional piezoelectric element array. 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 prior art. Each first matching layer 40 and each second matching layer 44 are horizontally arranged.
[0034]
In the present embodiment, a refractive layer array 46 is provided on the upper surface side of the second matching layer array 42. The refractive layer array 46 is constituted by a plurality of refractive layers, and these refractive layers alternately constitute an A group and a B group. FIG. 2 shows a refractive layer 52A constituting the A group, and the refractive layer 52A is composed of a first member 48A and a second member 50A as will be described in detail later. The same applies to the refractive layer 52B (described later) belonging to the B group. An acoustic lens 56 is provided on the upper surface side of the refractive layer array 46, and a backing layer 54 is provided on the lower surface side of the piezoelectric element array 34.
[0035]
As shown in the figure, the piezoelectric element 36, the first matching layer 40, the second matching layer 44, and the refractive layer 52A or 52B constitute one laminated body (vibrating element), and each laminated body is alternately A. It belongs to group and B group.
[0036]
3 and 4 are sectional views of the vibrator unit 33 shown in FIG. FIG. 3 shows a cross section of the refractive layer 52A, and FIG. 4 shows a cross section of the refractive layer 52B. In FIG. 3, the refraction layer 52A is constituted by a first member 48A provided on the upper side and a second member 50A provided on the lower side. Here, the first member 48A and the second member 50A are made of materials that change the sound speed of ultrasonic waves passing through the first member 48A. For the refraction layer 52A, the sound speed in the first member 48A is the second. It is larger than the speed of sound in the member 50A. Therefore, as shown in FIG. 3, the propagation path of the ultrasonic wave transmitted and received by the piezoelectric element 36 is tilted by a predetermined angle toward the right in FIG. Of course, the acoustic lens 56 also exhibits an ultrasonic wave converging action in the elevation direction, and the final direction of the transmitted and received waves is defined by a combination of the action of the refractive layer 52A and the action of the acoustic lens 56. Incidentally, the boundary surface between the first member 48A and the second member 50A is an inclined plane as shown, but the boundary surface may be a convex surface or a concave surface. The same applies to the refractive layer 52B described below.
[0037]
In FIG. 4, the refraction layer 52B is composed of a first member 48B disposed on the upper side and 50B disposed on the lower side, where the speed of sound of the passing ultrasonic wave is higher than the speed of sound in the second member 50B. The speed of sound in one member 48B is selected to be larger. In the refractive layer 52A and the refractive layer 52B, the first members 48A and 48B are composed of the same member, and the same applies to the second members 50A and 50B. According to the refractive layer 52B shown in FIG. 4, as described above, the propagation direction of the ultrasonic wave transmitted and received by the piezoelectric element 36 by the action of the refractive layer 52B can be tilted to the left in FIG. . In this embodiment, both the A group and the B group change the direction of the ultrasonic beam in the elevation direction. However, if at least one group deflects the ultrasonic beam, one transmission is performed. It is possible to set a plurality of received beams in different directions.
[0038]
Note that the acoustic impedances of the first member 48A and the second member 52A may be substantially the same, and a decrease in the transmittance of ultrasonic waves due to the occurrence of reflection between them may be prevented. The same applies to the first member 48B and the second member 52B.
[0039]
In FIG. 5, two receive beams 60 and 62 and a transmit beam 64 are shown. In FIG. 5, the horizontal axis indicates the distance in the elevation direction from the center of the piezoelectric element array, and the vertical axis indicates the relative amplitude as sound pressure or sensitivity. A reception beam 60 deflected to the right as shown in the figure is formed by the laminate constituting the A group, that is, the vibration element, and similarly, the reception beam 60 deflected to the left by the laminate constituting the B group, that is, the vibration element. A receive beam 62 can be formed. At the time of transmission, the laminated bodies of both groups, that is, the vibration elements are all used at the same time, thereby forming a single transmission beam 64 that combines the two transmission beams. Therefore, it is possible to perform two receptions per transmission and to double the number of scanning planes formed per unit time as compared with the prior art.
[0040]
In the present embodiment, so-called electronic sector scanning is applied. Of course, the same vibrator unit can be used when electronic linear scanning or other electronic scanning methods are applied.
[0041]
Next, FIG. 6 shows a block diagram of a main configuration of the ultrasonic diagnostic apparatus according to the present embodiment.
[0042]
The three-dimensional data acquisition probe 80 has the transducer unit 33 shown in FIG. The transducer 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.
[0043]
The scanning mechanism 82 is a mechanical mechanism that swings and scans the vibrator unit 33. Specifically, the scanning mechanism 82 includes a drive motor and a swing mechanism. A drive signal from the driver 86 is supplied to the drive motor, and a control signal from the scanning control unit 88 is sent to the driver 86. The position detector 84 is a detector that detects the swing position of the transducer unit 33 that is swing-scanned by the scanning mechanism 82. The detection signal is output to the scanning control unit 88.
[0044]
The scanning control unit 88 controls both mechanical scanning and electronic scanning. The scanning control unit 88 controls the scanning mechanism 82 via a driver 86 as shown in the figure, and the scanning control unit 88 transmits the transmission beam former 70 and the reception beam. A control signal is output to the formers 72 and 74.
[0045]
Here, the transmission beam former 70 is a circuit that forms a transmission beam 64 as shown in FIG. 5 by supplying transmission signals to a plurality of vibration 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 constituting 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 constituting the B group. The reception signals after the phasing addition output from the reception beam formers 72 and 74 are temporarily stored in the three-dimensional echo data memory as necessary, and then the reception signals are read out to form a three-dimensional image. Used for The circuit configuration example illustrated in FIG. 6 is an example, and various other circuit configuration examples can be employed.
[0046]
【The invention's effect】
As described above, according to the present invention, the frame rate can be improved when the echo data is taken in the three-dimensional region. Further, according to the present invention, it is possible to simultaneously form a plurality of reception beams in the elevation direction.
[Brief description of the 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 vibrator unit, 12 piezoelectric element array, 16 first matching layer array, 20 second matching layer array, 22, 24 laminate (vibrating element), 30 backing layer, 32 acoustic lens.

Claims (9)

In an ultrasonic probe having an array transducer composed of a plurality of vibration elements,
The plurality of vibration elements are divided into a plurality of groups,
The ultrasonic probe according to claim 1, wherein the transmission / reception direction of the vibration element is set to a different angle in the elevation direction between the groups. The ultrasonic probe according to claim 1,
Each vibration element includes a piezoelectric element,
An ultrasonic probe characterized in that piezoelectric elements are arranged at different inclination angles in the elevation direction between the groups. The ultrasonic probe according to claim 1,
Each vibration element constituting at least one group among the plurality of groups includes a piezoelectric element that transmits and receives ultrasonic waves and a refractive layer that refracts the propagation direction of the ultrasonic waves transmitted and received by the piezoelectric elements. ,
An ultrasonic probe characterized in that an angle in a transmission / reception direction is set using the refractive layer. The ultrasonic probe according to claim 1,
A single transmit beam is formed using the plurality of groups as a whole,
An ultrasonic probe, wherein a plurality of reception beams are formed using each group individually. In an ultrasonic probe having an array transducer composed of a plurality of vibration elements,
The plurality of vibration elements are divided into a plurality of groups,
Each of the vibration elements includes a piezoelectric element that transmits and receives ultrasonic waves and a refracting layer that refracts the propagation direction of ultrasonic waves transmitted and received by the piezoelectric elements,
The ultrasonic probe according to claim 1, wherein the refractive action of the refractive layer is different between the groups. The ultrasonic probe according to claim 5,
The ultrasonic probe according to claim 1, wherein the refractive layer includes a first member and a second member that are bonded to each other at an interface inclined with respect to the upper surface of the piezoelectric element and have different sound speeds. The ultrasonic probe according to claim 6,
The ultrasonic probe according to claim 1, wherein the first member and the second member have substantially the same acoustic impedance. In an ultrasonic probe for taking in three-dimensional data, including a transducer unit having an array transducer composed of a plurality of transducer elements, and a mechanical scanning mechanism that mechanically scans the transducer unit in the elevation direction ,
The plurality of vibration elements are divided into a plurality of groups,
The ultrasonic probe according to claim 1, wherein the transmitting and receiving directions of the vibration elements are set to different angles in the elevation direction between the groups. An ultrasonic probe including a vibration element array including a plurality of vibration element groups;
An apparatus main body connected to the ultrasonic probe;
Including
Between each vibration element group, the transmission / reception direction of ultrasonic waves is set at different angles in the elevation direction,
The apparatus main body is
A transmission unit for forming a transmission beam in the vibration element array;
A receiving unit for simultaneously forming a reception beam for each of the vibration element groups with respect to one transmission beam in the vibration element array;
An ultrasonic diagnostic apparatus comprising:

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