JP5345481B2 - Ultrasonic diagnostic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a side lobe and simplify constitution and control when two-dimensionally scanning ultrasonic beams using a two-dimensional array transducer in a three-dimensional ultrasonograph. <P>SOLUTION: A sub array pattern set on the two-dimensional array transducer 16 has four sub array groups A-D. Each sub array group A-D includes a plurality of X-directional connection bodies (vertically-long pairs) Px and a plurality of Y-directional connection bodies (laterally-long pairs) Py and those are closely and mixedly formed. Each X-directional connection body Px consists of a plurality of vertically-long sub arrays aligned in the X direction, while each Y-directional connection body Py consists of a plurality of laterally-long sub arrays aligned in the Y direction. Each sub array has a rectangular shape and the plurality of sub arrays with the same shape are aligned to constitute a square connection body, thereby attaining the diversity and closeness on the sub array pattern. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to an ultrasonic diagnostic apparatus including a 2D array transducer.

  Three-dimensional ultrasonic diagnosis is becoming widespread in the medical field. In such a three-dimensional ultrasonic diagnostic apparatus, an ultrasonic beam is scanned two-dimensionally, thereby forming a three-dimensional space (three-dimensional echo data capturing space), and based on the volume data obtained from the three-dimensional ultrasonic wave An image is formed. For the two-dimensional electronic scanning of the ultrasonic beam, a three-dimensional echo data capturing ultrasonic probe (3D probe) equipped with a 2D array transducer is used.

  The 2D array transducer is composed of a very large number of vibration elements that are two-dimensionally arranged (for example, composed of thousands of vibration elements). Therefore, in order to supply transmission signals to all the vibration elements and process reception signals from all the vibration elements, a large number of transmission circuits and reception circuits must be prepared, and a 3D probe is required. You will have to use heavy and heavy cables. Therefore, channel reduction on the probe side is required, and several methods for realizing it have been proposed as follows.

  In the first method, a plurality of subarrays are set on the array surface of the 2D array transducer, and grouping processing is applied to each subarray (see Patent Document 1 and Patent Document 2). That is, by setting a plurality of groups from the viewpoint of delay time similarity for each sub-array, and adding a plurality of element signals from a plurality of vibration elements in units of groups, a group reception signal is generated. It is intended to reduce.

  In the second method, a plurality of subarrays are set on the array surface of the 2D array transducer, and a sub-delay addition process (sub-phasing addition process) is executed for each subarray (see Patent Document 3). That is, channel reduction is achieved by applying a first-stage phasing addition to a plurality of element signals from a plurality of vibration elements constituting individual subarrays.

Japanese Patent No. 3977727 Japanese Patent No. 397826 Special table 2000-33087 gazette

  In order to improve the image quality of a three-dimensional ultrasonic image, it is desired to improve sensitivity and at the same time reduce side lobes (grating lobes). Adopting a subarray pattern in which a plurality of subarrays are simply closely aligned vertically and horizontally on the array surface can provide good sensitivity because the entire finite array surface can be used, but due to the regularity of the subarray arrangement, Side lobes are easy to come out. On the other hand, when a plurality of subarrays are set at random on the array surface, side lobes are difficult to appear, but a large number of gaps are generated on the array surface, resulting in a problem of reduced sensitivity. Although it is conceivable to give diversity to the shapes of the individual subarrays, in that case, computation and processing for causing the subarrays to function become complicated. Therefore, it is desirable to unify the subarray shapes to some extent ( For example, it is desirable to limit the use of one or several subarray shapes). In the three-dimensional measurement, consideration is required in terms of circuit scale reduction and control data reduction.

  An object of the present invention is to reduce side lobes and improve sensitivity in a three-dimensional ultrasonic diagnostic apparatus. Alternatively, an object of the present invention is to make it possible to simplify the configuration and control while obtaining good performance in a three-dimensional ultrasonic diagnostic apparatus.

  The present invention relates to a 2D array transducer having a two-dimensional array type transducer element in which a subarray pattern is set, and a plurality of element signals connected to the 2D array transducer in units of subarrays or groups of subarrays. A sub-processing unit that executes sub-processing and outputs a sub-processing result signal; and a main processing unit that performs main processing on a plurality of sub-processing result signals output from the sub-processing unit, wherein the sub-array pattern is A plurality of X-direction connectors arranged in a distributed manner and a plurality of Y-direction connectors arranged in a distributed manner, each X-direction connector comprising a plurality of vertically long subarrays aligned in the X direction, Each Y-direction connector is composed of a plurality of horizontally long subarrays aligned in the Y direction, and each of the vertically long subarrays is a rectangular subarray whose longitudinal direction is the Y direction. Each Horizontal subarrays are rectangular subarrays with the X direction as the longitudinal direction, characterized in that.

  In the above configuration, each connection body is a collection of a plurality of rectangular sub-arrays. Thus, in designing the subarray pattern, in principle, a connected body (that is, a prescribed shape block) can be used as a layout unit. In addition, it is easy to densely connect a plurality of connected bodies (that is, to improve sensitivity by eliminating unnecessary gaps). There are two types of connectors, X-direction connectors and Y-direction connectors, which are mixed as a whole of the sub-array pattern, so that the regularity of the sub-array pattern as a whole is destroyed and side lobes are reduced. I can plan. Diversity can be realized with such a simple configuration.

  Preferably, each X-direction connection body and each Y-direction connection body have the same square shape. According to this configuration, since the two types of connected bodies have the same shape and are square, it is easy to eliminate useless gaps, and when placing the connected body at a specific position during layout. It is easy to change the type. Since the square is a pattern unit, the burden can be reduced in terms of manufacturing and control.

  Preferably, the number of the plurality of X-direction coupling bodies and the number of the plurality of Y-direction coupling bodies are substantially the same. According to this configuration, the sensitivity in each direction can be balanced, and side lobes can be prevented from occurring in a specific direction.

  Preferably, each X-direction connector is a vertically long pair composed of two vertically long subarrays, and each Y-direction connector is a horizontally long pair composed of two horizontally long subarrays. Preferably, each of the X-direction connectors is composed of s vertically long subarrays, each of the vertically long subarrays is composed of m vibrating elements, and each of the Y-direction connectors is composed of s horizontally long subarrays, Each horizontally long subarray is composed of m vibration elements. That is, a connected body is configured by arranging a plurality of one-dimensional transducer arrays side by side. For example, s and m are arbitrary numerical values of 2 or more.

  The present invention relates to a 2D array transducer having a two-dimensional array type transducer element in which a subarray pattern is set, and a plurality of element signals connected to the 2D array transducer in units of subarrays or groups of subarrays. A sub-processing unit that executes sub-processing and outputs a sub-processing result signal; and a main processing unit that performs main processing on a plurality of sub-processing result signals output from the sub-processing unit, wherein the sub-array pattern is A plurality of subarray groups provided around the center point of the subarray pattern, and each subarray group includes a plurality of X-direction connectors distributed and a plurality of Y-direction connectors distributed. And each X-direction connector is composed of a plurality of vertically long subarrays aligned in the X direction, and each Y-direction connector is aligned in the Y direction. Consists of the number of horizontal sub-arrays, wherein each longitudinal sub-array is a rectangular sub-array to the Y direction is the longitudinal direction, each horizontal sub-array is a rectangular sub-array of the X-direction as the longitudinal direction, it is characterized.

  According to the above configuration, transmission and reception of ultrasonic waves are executed using a plurality of subarray groups provided around the center point. Each subarray group is composed of a plurality of X-direction connectors and a plurality of Y-direction connectors. The subarray population may further include isolated subarrays that do not constitute a linking body. In any case, since the sub-array population is configured by a plurality of sub-arrays being dense, it is possible to prevent the occurrence of sporadic gaps and increase the sensitivity. Desirably, the subarray pattern is configured so that “unevenness between groups” occurs between adjacent subarray groups. According to this configuration, generation of side lobes can be effectively reduced as compared with a case where a plurality of subarrays are simply and regularly arranged two-dimensionally. In order to create a non-uniformity between groups while ensuring the denseness within each subarray group, a rectangular central portion is preferably provided at the center of the subarray pattern. Such a gap can be a hindrance in a good sense and cause a shift between a plurality of subarray populations. Desirably, the disparity between populations is determined based on the subarray population on one side (specifically, the subarray column in contact with the other side subarray population and the subarray population on the other side (specifically, the subarray in contact with the one side subarray population). When the (column) is opposed to each other via the boundary line, the arrangement of both is shifted in the boundary line direction, meaning that the arrangement of both is not aligned.

  One or a plurality of invalid elements that do not function in transmission / reception may be included in the vibration element group constituting the 2D array vibrator. Preferably, the plurality of subarray populations constitute a circular area as a whole. In that case, the plurality of vibration elements existing outside the circular region are usually invalid elements. Desirably, each sub-array population exists within a specific azimuth angle when viewed from its center point. Desirably, four subarray groups are provided. In this case, the four subarray groups are divided into four quadrants (first quadrant, second quadrant, third quadrant, and fourth quadrant) that are each opened at 90 degrees on the array surface. In the quadrant).

  Desirably, each subarray group constitutes one control unit (first control unit), each subarray constitutes one control unit (second control unit), and is further set when a grouping method is adopted. Each group constitutes one control unit (third control unit). Of course, the sub-array group can be one control unit or circuit configuration unit. For example, a pattern selection signal (subarray control signal) for specifying a grouping pattern or a delay pattern is given for each subarray group. Such a pattern is dynamically controlled according to the beam scanning direction. Also, channel reduction processing is executed for each subarray. The channel reduction process includes a process of adding a plurality of element signals in units of groups, a process of phasing and adding a plurality of element signals in units of subarrays, and the like. When a plurality of groups are set in the sub-array, each group is usually composed of a plurality of vibration elements. A plurality of element signals output from a plurality of vibration elements in the group are added to generate a group reception signal. One group may be composed of one vibration element. In this case, an element signal output from the vibration element is output as it is as a group reception signal. Each subarray may include one or more invalid elements. A dedicated pattern selection signal may be given to the central sub-array. Alternatively, a pattern selection signal given to any one of the subarray groups may be diverted to the central subarray.

  Preferably, each of the subarray groups is composed of a plurality of densely and mixedly arranged X direction connectors and a plurality of Y direction connectors. Preferably, each of the subarray groups is composed of a plurality of dense and mixed X-direction connectors, a plurality of Y-direction connectors, and isolated subarrays. When providing a plurality of isolated sub-arrays, it is desirable to provide substantially the same number of vertical and horizontal sub-arrays.

  Preferably, four quadrants are defined by two boundary lines that pass through the center point and are orthogonal to each other, and four subarray groups are provided in the four quadrants. Preferably, a rectangular central portion is provided at the center of the subarray pattern, and four sides of the central portion are extended outward to form four boundary lines, and four quadrants are defined by the four boundary lines. In addition, four subarray groups are provided in the four quadrants, and unevenness between groups occurs between adjacent subarray groups across the boundary lines. Preferably, the irregularity between the groups is a state in which adjacent subarray groups are shifted in the direction of the boundary line between the two.

  Preferably, each of the subarray groups has an inscribed subarray closest to the center, and the inscribed subarray of each of the subarray groups touches a part of a specific side or a specific corner of the central portion of the rectangle. According to such a configuration, it is possible to naturally cause the above-described irregularity between groups.

  Desirably, the irregularity between groups is a state in which two adjacent subarray groups are shifted by m elements in the direction of the boundary line between them. That is, the unevenness between groups corresponds to a lateral shift in units of vibration elements. Preferably, the rectangular central portion has a size smaller than the size of each of the subarrays. Preferably, the central portion of the rectangle is composed of one or a plurality of reactive vibration elements. Alternatively, the central portion of the rectangle is composed of one or a plurality of effective vibration elements. In order to obtain the advantage of normalization of the subarray, it is desirable to adopt the former configuration.

  Preferably, each sub-process is a channel reduction process by grouping, and in each sub-array group, the same grouping pattern is set for a plurality of sub-arrays belonging thereto. Preferably, each sub-process is a channel reduction process by sub-phased addition, and in each sub-array group, the same delay pattern is set for a plurality of sub-arrays belonging thereto. Preferably, the plurality of subarray populations form a substantially circular region with the central subarray as a center.

  According to the present invention, it is possible to reduce side lobes and improve sensitivity in a three-dimensional ultrasonic diagnostic apparatus. Alternatively, in the three-dimensional ultrasonic diagnostic apparatus, the configuration and control can be simplified while obtaining good performance.

1 is a block diagram showing an embodiment of an ultrasonic diagnostic apparatus according to the present invention. It is a figure which shows an example of a principal part structure centering on the channel reduction circuit in the ultrasonic diagnosing device shown in FIG. It is a figure which shows the 1st example of a subarray pattern. It is an enlarged view which shows a vertically long pair and a horizontally long pair. It is a figure which shows the 2nd example of a subarray pattern. FIG. 6 is an enlarged view showing a central portion of the subarray pattern shown in FIG. 5. It is a figure which shows the 3rd example of a subarray pattern. It is a figure which shows the 4th example of a subarray pattern. It is a figure which shows the other example of a principal part structure centering on the channel reduction circuit in the ultrasonic diagnosing device shown in FIG. It is a figure which shows the example of a setting of the some group with respect to a vertically long subarray. It is a figure which shows the example of a setting of the several group with respect to a horizontally long subarray

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.

  FIG. 1 discloses an ultrasonic diagnostic apparatus. An ultrasonic diagnostic apparatus is an apparatus that forms an ultrasonic image by transmitting and receiving ultrasonic waves to and from a living body in the medical field. The ultrasonic diagnostic apparatus is roughly composed of a probe 10 and a main body 12. Reference numeral 14 denotes a probe cable for connecting the two. A connector provided on the probe 10 and a connector provided on the main body 12 are not shown.

  The probe 10 is an ultrasonic probe that transmits and receives ultrasonic waves in contact with the surface of a living body. However, the probe 10 may be inserted into the body cavity. The probe 10 includes a 2D array transducer 16 and a channel reduction circuit 18. They are provided in the probe head of the probe 10. However, the channel reduction circuit 18 may be provided in the probe connector. The 2D array transducer 16 includes, for example, thousands of transducer elements 16a, which are aligned in the X direction and the Y direction. For the vibration element group, that is, on the array surface, a subarray pattern including a plurality of subarrays is set. The subarray pattern is determined as described later from the viewpoints of simplification of control, reduction of side lobes, and improvement of sensitivity.

  The channel reduction circuit 18 is a circuit for reducing the number of signals (or signal lines) necessary for transmission / reception. According to the channel reduction circuit 18, the probe cable can be made thin, and the configuration of the transmission unit 20 and the reception unit 22 in the main body 12 can be simplified. As the channel reduction method, the configuration illustrated in FIG. 9 is employed when the grouping method is employed, and the configuration illustrated in FIG. 2 is employed when the sub phasing addition method is employed. When the grouping method is adopted, a plurality of groups are set for each sub-array, and at the time of transmission, the same transmission signal is supplied in parallel to a plurality of vibration elements constituting each group. A plurality of element signals (element reception signals) output in parallel from the plurality of vibration elements constituting the signal are added to generate a single group reception signal. On the other hand, when the sub-delay addition method is adopted as the channel reduction method, at the time of transmission, a plurality of transmission signals generated by delay processing on the original transmission signal are supplied in parallel to the plurality of vibration elements constituting the sub-array. During reception, a plurality of element signals output in parallel from a plurality of vibration elements constituting the sub-array are subjected to sub-phased addition processing to generate a sub-array reception signal.

  Next, the configuration of the main body 12 will be described. The transmission / reception control unit 24 controls setting of a grouping pattern or a delay pattern for each sub-array on the premise of the specific sub-array pattern adopted. The transmission unit 20 is a transmission beam former that generates a plurality of transmission signals corresponding to a plurality of subarrays. When the grouping method is adopted, transmission signals for the total number of groups are generated. When the sub phasing addition method is employed, transmission signals for the total number of sub arrays are generated. The receiving unit 22 is a receiving beam former. When the grouping method is employed, phasing addition processing is performed on the group reception signals for the total number of groups, and thereby beam data corresponding to the reception beam is obtained. When the sub phasing addition method is adopted, main phasing addition processing (second stage phasing addition processing) is performed on the sub array reception signals for the total number of sub arrays, thereby obtaining beam data corresponding to the reception beam. . The operations of the transmission unit 20 and the reception unit 22 are controlled by a transmission / reception control unit 24.

  The signal processing unit 26 includes a detector, a logarithmic converter, and the like, and executes various processes on the received reception signal after phasing addition, that is, beam data. The beam data after the signal processing is sent to the three-dimensional image processing unit 28, and the three-dimensional image processing unit 28 forms a three-dimensional ultrasonic image based on the plurality of beam data. The image data is sent to the display 30. As a three-dimensional image processing method, a volume rendering method, a surface rendering method, and the like are known. A plurality of beam data may be stored on a three-dimensional data memory to construct volume data, and a three-dimensional ultrasound image may be formed based on the volume data. The main control unit 32 includes a CPU and an operation program. An operation panel 34 including a keyboard and a trackball is connected to the main control unit 32. A circuit for processing Doppler information is not shown.

  FIG. 2 shows a partial configuration of the ultrasonic diagnostic apparatus shown in FIG. FIG. 2 is a block diagram showing a configuration example when the sub-beamforming method is adopted. A subarray pattern is set on the 2D array transducer 16 as will be described in detail later. The subarray pattern includes four subarray populations AD. Each of the subarray groups A to D includes a plurality of vertically long pairs (X direction connecting bodies) Px and a plurality of horizontally long pairs (Y direction connecting bodies) Py. They are dense and mixed. The vertically long pair Px includes two vertically long subarrays connected side by side in the X direction. The horizontally long pair Py is composed of two horizontally long subarrays connected side by side in the Y direction. To summarize, the subarray pattern includes a plurality of subarrays (SA-1 to SA-n), and n subarrays are set in this example. For example, n is a two-digit numerical value. Each pair (each connected body) Px, Py has a quadrangular shape and is composed of i × i vibration elements. For example, i is an even number such as 4, 6, 8, 10, 12, 14, 16, but the number can be arbitrarily determined. The size in the longitudinal direction of each sub-array corresponds to i vibration elements, and the size in the short direction corresponds to i / 2 vibration elements. In this embodiment, four subarray groups A to D are set in the first to fourth quadrants on the 2D array transducer 16 with the center of the subarray pattern as the origin. Each subarray population A to D is a subarray cluster (subarray cluster). It is also possible to form a regular quadrangular connection body by aligning a plurality of one-dimensional transducer arrays.

  A plurality of SBFs (sub beam formers) (38-1 to 38-n) constituting the channel reduction circuit 18 are connected to the plurality of sub arrays. The connection relationship is one-to-one. Each SBF is a circuit that executes a first-stage phasing addition process on a plurality of element signals output in parallel from the corresponding subarray. As a result, those element signals are aggregated into one received signal. At the time of transmission, a plurality of transmission signals having a delay relationship are generated from one transmission signal for each subarray, and these are supplied to a plurality of vibration elements constituting the subarray. The SBF also has a function as such a transmission beam former. The main beam former 22A and the transmission unit 20 are connected in parallel to the n SBFs. n signal lines 21-1 to 21-n are connected to the n SBFs.

  In the configuration example shown in FIG. 2, the transmission / reception control unit 24 outputs four control signal pairs, that is, eight control signals 37ax, 37ay, 37bx, 37by,... 37dx, 37dy (subscripts a, b , C, and d are identifiers of the subarray group, and the subscripts x and y are identifiers that specify whether the subarray is a vertically long type or a horizontally long type). That is, they are control signals for the first to fourth subarray groups A to D. Each control signal pair includes a signal that designates a delay pattern for the vertically long subarray and a signal that designates a delay pattern for the horizontally long subarray. That is, the same delay pattern is set for a plurality of vertically long subarrays in the first subarray group A, and the same delay pattern (delay condition) is set for a plurality of horizontally long subarrays in the same first subarray group A. The The same applies to other subarray populations. Since the subarray groups A to D are a cluster of a plurality of subarrays, that is, exist in the same local region, even if a common delay pattern is set for them, the transmission / reception characteristics are not deteriorated so much. . However, since the vertical sub-array and the horizontal sub-array have different conditions, it is necessary to provide different delay patterns for them. Here, the sub-array forms a sub-beamforming setting unit, and the sub-array group forms a control unit having a common delay pattern (vertical delay pattern, horizontal delay pattern). In this embodiment, the sub-array pattern is fixedly set on the array surface, but the delay pattern is dynamically variably set according to transmission / reception conditions such as the beam direction and the transmission focus depth. However, as described above, one type of delay pattern is set for a plurality of subarrays of the same type in each subarray group. Of course, various modifications can be considered for these conditions.

  n signal lines (21-1 to 21-n) are connected to n SBFs (38-1 to 38-n). The n signal lines are connected in parallel to the transmission unit 20 and the reception unit 22 in the main body. Therefore, in the illustrated configuration example, the transmission unit 20 outputs n transmission signals, and the reception unit 22 performs phasing addition processing on the n reception signals. In FIG. 2, a plurality of control signals are transmitted in parallel, but they may be transmitted in a time division manner using a single signal line. The transmission / reception control unit 24 may be provided in the probe 10.

  FIG. 3 shows a first example of a subarray pattern set on the 2D array transducer 16. As described above, the 2D array transducer 16 includes the plurality of vibration elements 16a aligned in the X direction and the Y direction. A circular area 103 is an area where waves are actually transmitted and received. Individual rectangles indicate subarrays.

  The subarray pattern has a plurality of subarray groups A to D provided around the center thereof. Each subarray group is composed of a plurality of densely arranged subarray pairs, and specifically includes a plurality of vertically long pairs Px and a plurality of horizontally long pairs Py. Both are provided in substantially the same number. The plurality of vertically long pairs Px and the plurality of horizontally long pairs Py are two-dimensionally mixed. The two types of pairs Px and Py have the same shape, that is, the same quadrangle. The square has a size of i element × i element.

  As shown in FIG. 4, each vertically long pair Px is composed of two vertically long subarrays 112 and 114 connected side by side in the X direction. Here, each vertically long subarray 112 and 114 has the Y direction as the longitudinal direction. Has a rectangular shape. Each horizontally long pair Py is composed of two horizontally long subarrays 116 and 118 connected side by side in the Y direction. Here, each horizontally long subarray 116 and 118 has a rectangle whose longitudinal direction is the X direction. The size of each subarray 112 to 118 in the longitudinal direction corresponds to i (4 in the illustrated example) vibration elements, and the size of each subarray 112 to 118 in the short direction is i / 2 (2 in the illustrated example). This corresponds to a vibration element. However, non-standard subarrays may be included in the subarray population.

  Returning to FIG. 3, the boundary line between the sub-array populations is represented by x and y. Their boundaries cross at the center point. When attention is paid to the boundary lines x and y, the alternating arrangement is realized so that the same type of sub-array pairs are not arranged on one side and the other side of the boundary line. When the entire subarray pattern is observed, a two-dimensional alternating arrangement of two types of subarray pairs is realized. If the number of types of subarrays is suppressed to a very small number as the entire subarray pattern, an advantage that the configuration and control can be simplified can be obtained. Since only two types of sub-arrays are used in the example shown, such advantages can be effectively extracted. Moreover, since each subarray pair is configured as a quadrangle having the same shape, it is possible to provide diversity (non-uniformity) within the subarray population while avoiding the problem of generating unnecessary gaps within the subarray population. it can.

  The second to fourth examples of the subarray pattern will be described with reference to FIGS. In each figure, the same reference numerals are given to the same components as those shown in FIG. 3, and the description thereof is omitted.

  In the second example shown in FIG. 5, the subarray pattern set on the 2D array transducer 16 </ b> A includes a rectangular central portion 100 and four subarray groups A to D provided around the central portion 100. Each of the subarray groups A to D includes a plurality of vertically long pairs Px and a plurality of horizontally long pairs Py that are two-dimensionally mixed.

  In the center of the 2D array transducer 16A, a rectangular central portion 100 smaller than the prescribed size of the subarray pair is set, and four subarray groups A to D are arranged so as to surround the center portion 100 and close to the center side. Is provided. The four subarray groups A to D are provided in the first to fourth quadrants when an orthogonal coordinate system with the center on the 2D array transducer 16A as the origin is defined. Each subarray population A to D is composed of a plurality of subarrays that are densely packed together, and there is no substantial gap in each subarray population.

  FIG. 6 shows the central portion of the subarray pattern as an enlarged view. The boundary lines x1, y1, x2, and y2 correspond to extended lines extending from the four sides 104-1 to 104-4 of the central portion 100 to the outside. The boundary line x1 and the boundary line x2 extend in opposite directions (positive direction and negative direction), and they are shifted by the width of the central portion 100 in the Y direction. The boundary line y1 and the boundary line y2 also extend in opposite directions, and they are shifted by the width of the central portion 100 in the X direction. Reference numerals 106-1 to 106-4 indicate four corners of the central portion 100. O is the center of gravity of the central portion 100 and the center of the 2D array transducer 16.

  Returning to FIG. 5, focusing on the first sub-array group A, it includes the inscribed sub-array SAa1 closest to the central sub-array A, which touches a specific side (side on y1) of the central portion 100. . Based on that, other subarrays are packed close to the center. Similarly to the first subarray population A, the second subarray population B, the third subarray population C, and the fourth subarray population D are each composed of a plurality of densely arranged subarrays. Specifically, the inscribed subarrays SAb1, SAc1, It has SAd1 and a plurality of subarrays extending in series.

  When attention is paid to the boundary lines x1, y1, x2, y2 between adjacent ones in the four subarray groups A to D, irregularities (ununiformity between groups) are generated on each boundary line. For example, on the boundary line y1, there is a shift of i / 2 elements in the Y direction between the first subarray group A and the second subarray group B. Similarly, on the boundary line x2, there is a shift of i / 2 elements in the X direction between the second subarray group B and the third subarray group C. Similarly, between the third subarray population C and the fourth subarray population D, and between the fourth subarray population D and the first subarray population A, only i / 2 elements in the X direction or the Y direction. There is a gap. As a result, four inter-group irregularities occur between the four adjacent groups in the four subarray groups A to D. Since the subarray pair column on one side and the subarray pair column on the other side are shifted in the direction of the boundary line across the boundary line, the diversity of the subarray pattern can be further increased. As a result, a remarkable sidelobe reduction effect can be expected.

  In the third example shown in FIG. 7, the subarray pattern set on the 2D array transducer 16B has four subarray groups A to D. Each subarray population A to D includes a plurality of vertically long pairs Px, a plurality of horizontally long pairs Py, and one isolated subarray. The first subarray group A and the third subarray group C have isolated subarrays Q1 and Q3 as horizontally long subarrays in contact with the center point of the subarray pattern. They correspond to the inscribed subarray. The second subarray group B and the fourth subarray group D have isolated subarrays Q2 and Q4 as vertically long subarrays in contact with the center point of the subarray pattern. They also correspond to the inscribed subarray. By providing each of these four isolated inscribed subarrays in a windmill and forming each subarray group (a group of subarray pairs), it is possible to naturally create irregularities among the subarray groups. In this case, there is no gap in the center, so that the effective area can be used for transmission and reception.

  In the fourth example shown in FIG. 8, the subarray pattern set on the 2D array transducer 16 </ b> C includes a central portion 100 and four subarray groups A to D. This example 4 corresponds to a combination of the pattern shown as the second example and the pattern shown as the third example. That is, four isolated inscribed sub-arrays Q1 to Q4 are provided in a windmill shape so as to contact four sides of the central portion 100, and a plurality of vertically long pairs Px and a plurality of horizontally long pairs Py are densely arranged in each quadrant. ing. When attention is paid to the boundary line, unevenness occurs between adjacent groups, and the amount of deviation between one side and the other side corresponds to the size of the central portion 100.

  FIG. 9 shows a partial configuration of the ultrasonic diagnostic apparatus shown in FIG. FIG. 9 is a block diagram showing a configuration example when the grouping method is adopted. The same components as those shown in FIG. 2 are denoted by the same reference numerals, and the description thereof is omitted.

  A plurality of SW (switch) circuits (SW1-SWn) constituting the channel reduction circuit 18 are connected to the plurality of subarrays (SA-1 to SA-n). The connection relationship is one-to-one. Each SW circuit sets a plurality of groups for the corresponding sub-array. Each group is composed of a plurality of vibration elements having a relationship in which delay amounts are approximate to each other. By such grouping, the same transmission signal can be supplied in parallel to a plurality of vibration elements constituting the group, and a plurality of element signals output in parallel from the plurality of vibration elements constituting the group are added to 1 One group received signal can be generated. That is, channel reduction can be achieved at the time of transmission / reception. Note that a plurality of groups are set for one subarray, and exceptionally, a group constituted by one vibration element may be included therein. Further, some vibration elements in the sub-array may be invalid vibration elements. A transmit-only element and a receive-only element may be set in the subarray.

  The four control signals 36ax, 36ay, 36bx, 36by,... 36dx, 36dy are signals that specify delay patterns. That is, two types of control signals for a vertically long pair and a horizontally long pair are given to each subarray group. Since the control signal can be shared for each subarray group and for each subarray type, the circuit configuration can be simplified. A signal line string is connected to each of the SW circuits SW1-SWn. The signal line array includes a number of signal lines corresponding to the maximum number of groups that can be set in one subarray. In FIG. 9, the number is represented as j. The n signal line trains are connected in parallel to the transmission unit 20 and the reception unit 22 in the main body. Therefore, in the illustrated configuration example, the transmission unit 20 outputs n × j transmission signals, and the reception unit 22 performs phasing addition processing on the n × j reception signals. In FIG. 9, a plurality of control signals are transmitted in parallel using a plurality of signal lines. However, they may be time-division transmitted on a single signal line. The transmission / reception control unit 24 may be provided in the probe 10.

  Even when such a sub-processing method is selected, any one of the first to fourth examples can be adopted as the sub-array pattern, and other sub-array patterns can also be adopted. In any case, side lobes can be effectively reduced by utilizing the unevenness between groups while increasing the sensitivity by concentrating the subarrays.

  FIG. 10 shows several grouping pattern examples set in the vertically long subarray. Each number indicates a group number to which the vibration element belongs. A plurality of vibration elements having the same number are electrically connected. FIG. 11 shows several grouping patterns set in the horizontally long subarray. The grouping pattern is dynamically switched with the movement of the three-dimensional position of the transmission focus point. The grouping pattern shown in (C) of each figure includes invalid elements that do not belong to any group.

  10 probe, 12 body, 14 probe cable, 16 2D array transducer, 18 channel reduction circuit, 20 transmission unit, 22 reception unit, 24 transmission / reception control unit.

Claims (14)

A 2D array transducer having a two-dimensional array type vibration element group in which a subarray pattern is set;
A sub-processing unit that is connected to the 2D array transducer and performs sub-processing on a plurality of element signals in units of sub-arrays or in groups of sub-arrays and outputs a sub-processing result signal;
A main processing unit that performs main processing on a plurality of sub-processing result signals output from the sub-processing unit;
Including
The sub-array pattern includes a plurality of X-direction connectors that are distributed and a plurality of Y-direction connectors that are distributed.
Each of the X-direction connectors is composed of a plurality of vertically long subarrays aligned in the X direction,
Each Y-direction coupling body is composed of a plurality of horizontally long subarrays aligned in the Y direction,
Each of the vertically long subarrays is a rectangular subarray whose longitudinal direction is the Y direction,
Each of the horizontally long subarrays is a rectangular subarray whose longitudinal direction is the X direction.
An ultrasonic diagnostic apparatus. The apparatus of claim 1.
The ultrasonic diagnostic apparatus, wherein each of the X direction coupling bodies and each of the Y direction coupling bodies has the same square shape. The apparatus of claim 2.
The ultrasonic diagnostic apparatus, wherein the number of the plurality of X-direction coupling bodies and the number of the plurality of Y-direction coupling bodies are substantially the same. The apparatus of claim 3.
Each X-direction connector is a vertically long pair composed of two vertically long subarrays,
The ultrasonic diagnostic apparatus according to claim 1, wherein each Y-direction connector is a horizontally long pair including two horizontally long subarrays. The apparatus of claim 3.
Each of the X-direction connectors is composed of s vertically long sub-arrays, and each of the vertically long sub-arrays is composed of m vibration elements,
Each of the Y-direction coupling bodies is composed of s laterally long sub-arrays, and each of the laterally long sub-arrays is composed of m vibration elements.
An ultrasonic diagnostic apparatus. The device according to any one of claims 1 to 5,
The subarray pattern has a plurality of subarray populations provided around the center point of the subarray pattern,
Each subarray group includes a plurality of mixed X-direction connectors and a plurality of Y-direction connectors.
An ultrasonic diagnostic apparatus. The apparatus of claim 6.
Each of the sub-array populations is composed of a plurality of dense and mixed X-direction connectors and a plurality of Y-direction connectors.
An ultrasonic diagnostic apparatus. The apparatus of claim 6.
Each subarray group is composed of a plurality of dense and mixed X-direction connectors, a plurality of Y-direction connectors, and an isolated subarray.
An ultrasonic diagnostic apparatus. The apparatus of claim 6.
Four quadrants are defined by two boundary lines passing through the center point and orthogonal to each other,
Four subarray populations were provided in the four quadrants,
An ultrasonic diagnostic apparatus. The apparatus of claim 6.
A rectangular central portion is provided at the center of the subarray pattern,
The four sides of the central portion are extended outward to form four boundary lines,
Four quadrants are defined by the four boundaries,
Four subarray groups are provided in the four quadrants,
Inter-group irregularity occurred between adjacent subarray groups across each boundary line,
An ultrasonic diagnostic apparatus. The apparatus of claim 10.
The irregularity between the groups is a state in which the adjacent subarray group is shifted in the direction of the boundary line between the two,
An ultrasonic diagnostic apparatus. The apparatus of claim 1.
Each of the sub processes is a channel reduction process by grouping,
In each subarray population, the same grouping pattern was set for a plurality of subarrays belonging to it,
An ultrasonic diagnostic apparatus. The apparatus of claim 1.
Each of the sub processes is a channel reduction process by sub phasing addition,
In each subarray group, the same delay pattern was set for a plurality of subarrays belonging to it,
An ultrasonic diagnostic apparatus. The apparatus of claim 1.
The subarray pattern comprises a substantially circular region;
An ultrasonic diagnostic apparatus.