JP2005034633A - Ultrasonic diagnostic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a beam profile regardless of a beam scanning direction when a plurality of sub-arrays are set on a 2D array vibrator in ultrasonic diagnostic equipment. <P>SOLUTION: The sub-array shaped pattern of each of the sub-arrays is altered adaptively corresponding to a beam scanning direction and each of the sub-arrays is constituted of a plurality of groups while each of the groups is constituted of a plurality of vibration elements. The group shaped pattern of each of the groups is also changed by a change in the sub-array shaped pattern corresponding to the beam scanning direction. The sub-array shaped pattern changes at every sub-array but fluctuation ranges are determined by the maximum outer edge of the change in the sub-array shaped pattern. The fluctuation ranges are partially overlapped with each other between a plurality of the sub-arrays. A plurality of the sub-arrays are always closely connected to each other on the 2D array vibrator even if the array shape pattern of the sub-arrays fluctuates. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ultrasonic diagnostic apparatus used in the medical field, and more particularly to setting a plurality of subarrays on an array transducer.

  The ultrasonic diagnostic apparatus is used for diagnosing a disease of a living body (patient) in the medical field. Specifically, the ultrasonic diagnostic apparatus transmits an ultrasonic pulse to a living body, receives a reflected wave from the living body, and forms an ultrasonic image based on a reception signal obtained by the reception.

  A two-dimensional (2D) array transducer is used to two-dimensionally scan the ultrasonic beam, thereby forming a three-dimensional echo data capture space in the living body. In general, a 2D array vibrator is formed by aligning a plurality of vibration elements in the X direction and the Y direction.

  In some cases, a plurality of subarrays are set on the 2D array transducer for channel reduction of the transmission / reception unit, simultaneous formation of a plurality of reception beams, or other purposes. Conventionally, a plurality of subarrays are fixedly set on the 2D array transducer. For example, a plurality of subarrays having a rectangular shape are set for the 2D array transducer. In this case, the shape of each subarray cannot be changed. Japanese Patent Application Laid-Open No. 2001-276064 discloses grouping of a plurality of vibration elements, but the configuration of each group is fixed. Japanese Patent Laid-Open No. 2001-104303 discloses a configuration in which phasing addition is performed in two stages. In FIG. 6 of JP-A-9-322896, a plurality of groups are fixedly set in the 2D array transducer, a plurality of first beam formers are connected to the plurality of groups, and a plurality It is shown that a plurality of second beam formers are provided after the first beam former. US Pat. No. 5,832,923 discloses setting a plurality of 2D subarrays on a 2D array transducer and setting a plurality of groups on each subarray. However, none of the documents describes changing the shape of the subarray dynamically.

  If the configuration or form of the subarray is fixedly set, there is a problem that a good beam profile cannot be obtained depending on transmission / reception conditions. For example, side lobes are likely to appear in a specific beam scanning direction.

JP 2001-276064 A JP 2001-104303 A JP-A-9-322896 US Pat. No. 5,832,923

  An object of the present invention is to provide an ultrasonic diagnostic apparatus capable of obtaining a good beam profile.

  Another object of the present invention is to make it possible to maintain or improve the image quality of an ultrasonic image when performing channel reduction of a transmission / reception unit.

(1) An ultrasonic diagnostic apparatus according to the present invention includes an array transducer having a plurality of vibration elements arranged two-dimensionally, a switching unit that sets a plurality of subarrays for the plurality of vibration elements, A reception processing unit that processes a plurality of reception signals output from the array transducer, wherein the switching unit changes a subarray shape pattern of at least one subarray in the array transducer.

  According to the above configuration, the switching unit sets a plurality of subarrays on the array transducer. Since the switching unit has a function of changing the sub-array shape pattern of the sub-array, it is possible to solve or improve the problems caused by fixedly setting the sub-array shape pattern of the sub-array as in the conventional art. For example, the side lobe can be reduced by changing the beam profile to a better one by changing the subarray shape pattern.

  Preferably, the switching unit changes each sub-array shape pattern for the plurality of sub-arrays. The plurality of subarrays are desirably closely connected to each other on the array transducer from the viewpoint of acoustic power or sensitivity. In other words, it is desirable that all the vibration elements constituting the array transducer belong to one of the subarrays. However, a gap may exist between the subarrays. That is, there may be a vibration element that does not belong to any subarray and does not function for transmission / reception. Further, when a certain subarray shape pattern is selected, there may be a plurality of vibration elements that do not function in transmission / reception around the array transducer.

  Preferably, the same subarray shape pattern is set for the plurality of subarrays. According to this configuration, it is easy to connect a plurality of subarrays closely. Of course, the subarray shape pattern may be individually set for each subarray.

  Preferably, a control unit that switches the subarray shape pattern according to beam forming conditions is further included. Preferably, the array transducer is a 2D array transducer in which a plurality of transducer elements are aligned in the X direction and the Y direction, and the beam forming condition includes a beam scanning direction on the XY plane. The beam forming conditions can further include a beam deflection angle, a beam width, a beam shape, and the like.

  Preferably, the switching unit further sets a plurality of groups for each of the sub-arrays, wherein each group includes a plurality of vibration elements. The reception processing unit processes a group reception signal output for each group in each subarray, and the switching unit further changes the group shape pattern of each group in accordance with the change of the subarray shape pattern. To do.

  According to this configuration, the switching unit performs subarray setting and group setting. In that case, it is possible to set a desired subarray shape pattern and a desired group shape pattern.

  For example, if n (where 1 <n <m) groups are set for m vibration elements constituting a certain subarray, the channel reduction rate is n / m. If such channel reduction processing is performed in the probe head, there is an advantage that the number of signal lines through which the probe cable is inserted can be reduced. That is, by grouping, a plurality of received signals can be added and aggregated into one received signal (group received signal). In addition, one transmission signal can be supplied in parallel to a plurality of vibration elements constituting one group.

  Preferably, the number of vibration elements constituting each group is varied according to beam forming conditions. Preferably, the beam forming condition includes a beam scanning direction. Desirably, each subarray includes one or a plurality of reactive vibration elements according to beam forming conditions. Here, the ineffective vibration element is a vibration element that is not used for transmission and reception of ultrasonic waves. In the sub-array, a plurality of vibration elements other than one or a plurality of ineffective vibration elements are effective vibration elements, and the plurality of effective vibration elements are divided into a plurality of groups.

  The plurality of groups set for each of the subarrays may be configured by the same number of vibration elements. According to this configuration, the number of received signals added can be made the same between the groups, and the number of transmission signal branches (the number of output destinations) can be made the same between the groups.

  The same group shape pattern may be set for the plurality of groups. In this case, a group shape pattern that is substantially linear with respect to each group may be set. Each group is desirably set in a linear form so as to intersect (preferably orthogonally) with respect to the beam scanning direction, or like a string having a thin width in the direction.

  Preferably, a control unit that switches the group shape pattern together with the subarray shape pattern according to beam forming conditions is included. Preferably, the plurality of sub-arrays are closely connected to each other even when the array shape pattern is changed. If a plurality of sub-arrays are closely connected, many usable vibration elements can be operated to increase the acoustic power.

  Preferably, a pattern variation area is defined for each subarray, whereby a plurality of pattern variation areas are defined on the array transducer, and the pattern variation area for each subarray combines a plurality of subarray shape patterns. The plurality of pattern variation areas have portions that partially overlap each other. Preferably, each pattern variation region covers a plurality of vibration elements unique to each sub-array and a plurality of vibration elements present in the overlapping portion.

(2) An ultrasonic diagnostic apparatus according to the present invention sets an array transducer having a plurality of vibration elements, a plurality of subarrays for the plurality of vibration elements, and sets a plurality of groups for each subarray. A switching unit that outputs a group reception signal for each group, a reception processing unit that processes a plurality of group reception signals output from the switching unit, and a control that controls the switching unit according to beam scanning conditions The control unit controls the operation of the switching unit to change the subarray shape pattern of each subarray and to change the group shape pattern of each group.

  Preferably, the reception processing unit performs a sub phasing addition process on a plurality of group reception signals output from the sub arrays, and outputs a sub phasing addition signal; and And a main phasing and adding circuit that executes a main phasing and adding process on the plurality of sub phasing and addition signals output from the plurality of sub phasing and addition units.

  According to the above configuration, after the sub phasing addition processing is performed for each group, the main phasing addition processing is applied to the plurality of sub phasing addition signals. A plurality of main phasing and adding circuits may be arranged in parallel, and a plurality of reception beams may be simultaneously formed by one reception. In the probe cable, the transmission signal may be transmitted as a voltage signal, and the reception signal may be transmitted as a current signal. The transmission signal may be a voltage signal of about 100 V, or may be a low voltage signal of about several volts to several tens of volts. In the latter case, for example, it is desirable to laminate each vibration element, thereby reducing the electrical impedance of each vibration element.

  Desirably, at least the array transducer and the switching unit are provided in the probe head. Further, a plurality of sub phase adjusting and summing circuits may be provided in the probe head (in this case, the number of signal lines can be further reduced), or a plurality of sub phase adjusting and summing circuits may be provided in the probe connector or the apparatus main body. You may make it provide in. The transmission unit can be provided in the probe head, the cable connector, or the apparatus main body.

(3) Further, the ultrasonic diagnostic apparatus according to the present invention controls an array transducer having a plurality of vibration elements, a switching unit that sets a plurality of subarrays for the plurality of vibration elements, and the switching unit. And a controller that adaptively changes the subarray shape pattern of each of the subarrays according to the beam scanning direction.

  Preferably, each subarray shape pattern is configured by a plurality of pattern elements, and each pattern element is configured by a vibration element array. Preferably, each of the vibrating element rows is substantially orthogonal to the beam scanning direction. Preferably, when the beam scanning direction is 0 degrees, 90 degrees, 180 degrees, and 270 degrees, the shape of each subarray is a quadrangle, and when the beam scanning direction is other than the angle, The shape of each sub-array is deformed from the quadrangle and becomes a parallelogram or a shape close thereto. Even if the shape of each sub-array is a parallelogram or a shape close to it, it is desirable that a plurality of sub-arrays be closely connected to each other.

  Preferably, the control unit sets one or more reactive vibration elements in each sub-array according to the beam scanning direction, and a plurality of other than the one or more reactive vibration elements in each sub-array. A plurality of groups are set using effective vibration elements. Preferably, the control unit sets a plurality of groups in each sub-array according to the beam scanning direction, and the control unit changes a group shape pattern of each group according to the beam scanning direction. In addition, the number of vibrating elements constituting each group is changed according to the beam scanning direction.

  As described above, according to the present invention, an ultrasonic diagnostic apparatus capable of obtaining a good beam profile can be provided. Alternatively, according to the present invention, it is possible to maintain or improve the image quality of an ultrasonic image when performing channel reduction of a transmission / reception unit.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, the basic configuration of the ultrasonic diagnostic apparatus according to the present embodiment will be described with reference to FIG. The ultrasonic diagnostic apparatus includes a probe (probe unit) 240 and an apparatus main body 242. The probe 240 has a probe head 244, a probe cable 246, and a cable connector 247. The apparatus main body 242 includes a transmission / reception control unit 248, a reception unit 250, a signal processing module 252, an image forming unit 254, and a display unit 256. The cable connector 247 is detachably connected to a connector (not shown) of the apparatus main body 242. An electronic circuit 249 is built in the cable connector 247 in this embodiment. The electronic circuit 249 performs a sub-phasing addition process and a transmission signal generation process, as will be described in detail later with reference to FIGS. 1 and 2. The receiving unit 250 executes main phasing addition processing. The probe head 244 transmits and receives ultrasonic waves. The received signal thus obtained is input to the image forming unit 254 via the electronic circuit 249, the receiving unit 250 and the signal processing module 252. In this image forming unit 254, an ultrasonic image is formed based on the received signal. The ultrasonic image is displayed on the screen of the display 256. As the ultrasonic image, a two-dimensional tomographic image, a two-dimensional blood flow image, a three-dimensional image, and the like are known. In the present embodiment, a volume rendering process is performed on volume data acquired from a 3D space in a living body to form a 3D image. Various other methods for forming a three-dimensional image are known.

  FIG. 1 is a block diagram illustrating a configuration of a transmission / reception unit in the ultrasonic diagnostic apparatus according to the embodiment. The illustrated ultrasound diagnostic apparatus includes a probe unit and an apparatus main body 12, and the probe unit includes a probe head 10, a probe cable 14A, and a cable connector 14B.

  In the present embodiment, a plurality of transmission / reception modules 24 (that is, equivalent to the electronic circuit 249 described later) are accommodated in the cable connector 14B. However, a plurality of transmission / reception modules 24 can be provided in the probe head 10 or in the apparatus main body 12.

  The probe head 10 is, for example, a transducer that is used in contact with the body surface and transmits and receives ultrasonic waves. The probe head 10 has a 2D array transducer 16. An ultrasonic beam is formed by the 2D array transducer 16. The ultrasonic beam is electronically scanned two-dimensionally. As a result, a three-dimensional echo data capturing space (three-dimensional space) is formed. Examples of the ultrasonic beam electronic scanning method include an electronic sector scanning method.

  In the present embodiment, the array transducer 16 is configured by a large number (for example, 3000 or 4000) of vibration elements 16a. These vibration elements 16a are two-dimensionally arranged (see FIG. 3 described later). The switching circuit 20 is configured as a multiplexer or a switching matrix. In the present embodiment, the switching circuit 20 has a function of setting a plurality of subarrays on the 2D array transducer 16 and a function of setting a plurality of groups for each subarray. The switching circuit 20 has a function of changing the shape of each subarray (subarray shape pattern) and a function of changing the shape of each group (group shape pattern). The switching circuit 20 may be configured by a single circuit as illustrated in FIG. 1 or may be configured by a plurality of circuits.

  In FIG. 1, a plurality of subarrays S set by the switching circuit 20 are conceptually shown. On the 2D array transducer 16, the plurality of subarrays S are closely connected to each other, and the plurality of subarrays S are basically configured using all the vibration elements 16a. As described above, in the present embodiment, the subarray shape pattern can be changed for each subarray, and the pattern variation region for each subarray is conceptually indicated by the symbol R in FIG. The subarray shape pattern and its changing method will be described in detail later. A plurality of groups are set for each subarray. As the subarray shape pattern is changed, each group shape pattern is also changed. However, in the present embodiment, the number of vibrating elements constituting each group is unchanged and is a constant number. Of course, the number of vibration elements constituting each group may be individually variably set. In addition, you may make it set a subarray shape pattern separately for every subarray.

  In the present embodiment, each subarray is composed of 5 × 5 = 25 vibration elements. The 25 vibration elements are grouped into 5 groups. Each group is composed of five vibration elements. That is, a channel reduction rate of 1/5 is realized in the probe head 10.

  The switching circuit 20 has the same number of terminals as the number of vibration elements constituting the 2D array vibrator 16 on the 2D array vibrator 16 side, and has the same number of terminal arrays on the apparatus main body 12 side as the number of subarrays. ing. In the example shown in FIG. 1, each terminal row on the apparatus main body 12 side includes five terminals (the same number of terminals as the number of groups set on one subarray). Specifically, the switching circuit 20 selectively connects the element signal line array and the group signal line array. Here, the group signal line array is constituted by a plurality of group signal line sets 22, and each group signal line set 22 is constituted by five group signal lines in the example shown in FIG. The switching circuit 20 has a plurality of switches (not shown) provided at the intersections between the element signal line array and the group signal line array. The on / off operation of each switch selects one or a plurality of vibration elements connected to each group signal line. The switching circuit 20 can change the number of vibrating elements constituting each group according to the beam scanning direction (that is, the beam deflection direction), and 1 or within the sub-array according to the beam scanning direction. It is also possible to set a plurality of ineffective vibration elements (vibration elements that are not connected to any group signal line and do not transmit and receive ultrasonic waves). Incidentally, it is possible to configure each subarray by, for example, 4 × 4 = 16 vibration elements, and group the 16 vibration elements into, for example, four groups, and also configure subarrays and groups under other conditions. You may do it.

  As can be understood from the above description, the switching circuit 20 outputs five group received signals for each subarray. Each group reception signal is a signal obtained by adding five reception signals output from five vibration elements constituting one group. In the present embodiment, the addition is realized by a simple addition method using connection. That is, five received signals are added by interconnection of five signal lines. However, a weighted addition method or the like may be employed. On the other hand, as will be described later, in the cable connector 14B, five transmission signals are generated for each sub-array, and these five transmission signals are divided into five groups constituting the corresponding sub-array. Supplied against. That is, one transmission signal is supplied in parallel to the five vibration elements constituting one group. That is, one transmission signal is branched into five in the switching circuit 20.

  As described above, reference numeral 22 denotes a signal line set provided for each subarray. Each signal line set 22 includes five signal lines (five group signal lines). The above transmission signal and reception signal are transmitted to each signal line. Incidentally, the reception signal may be transmitted as a current signal and the transmission signal may be transmitted as a voltage signal. In this case, the transmission signal may be a voltage signal of about 100V, for example, or a low voltage signal of about several volts. The probe cable 14A has a plurality of signal line sets 22, and also has one or more control lines for transmitting control signals and the like. In FIG. 1, the illustration of power lines inserted into the probe cable 14 </ b> A is omitted.

  The cable connector 14B has, for example, a box shape, and a plurality of transmission / reception modules 24 are accommodated therein as described above. Each transmission / reception module 24 includes a transmission unit and a sub phase adjusting and adding circuit 26, as will be described later. The transmitter has five transmitters, which generate five transmission signals for each subarray. The sub phasing / adding circuit 26 is a circuit that performs sub phasing / adding processing on the five received group signals. As a result, a sub-phasing addition signal 27 is generated for each sub-array.

  In the apparatus main body 12, in this embodiment, a main phasing and adding circuit 30 and a transmission / reception control unit 32 are provided. The main phasing and adding circuit 30 receives a plurality of sub phasing and adding signals 27 and executes main phasing and adding processing, thereby generating a main phasing and adding signal (received beam signal) 31. In the phasing addition process, a known reception dynamic focus technique can be applied. Each sub phase adjusting and adding circuit 26 and the main phase adjusting and adding circuit 30 are configured as analog phase adjusting and adding circuits or as digital phase adjusting and adding circuits.

  The transmission / reception control unit 32 controls the operation of each component shown in FIG. 1. In particular, the transmission / reception control unit 32 sets the phasing addition conditions in the plurality of sub phasing addition circuits 26 and the phasing in the main phasing addition circuit 30. Addition conditions are set. The transmission / reception control unit 32 outputs a control signal to the switching circuit 20 provided in the probe head 10, and a plurality of sub-arrays and a plurality of groups are set by the control signal. Is called.

  FIG. 2 shows a specific configuration example of the transmission / reception module 24 shown in FIG. As described above, the transmission / reception module 24 includes the transmission unit 36, the sub phase adjusting and adding circuit 26, and the plurality of transmission circuits 34. Here, each transmission circuit 34 functions as a transmission pulser and a reception head amplifier circuit. Each transmission circuit 34 outputs a transmission signal to the signal line at the time of transmission, and transmits a reception signal input from the signal line to the sub phasing addition circuit 26 at the time of reception. The transmission unit 36 includes five transmitters 38. Each transmitter 38 outputs a transmission signal to which a predetermined delay time is given.

  The sub phase adjusting and adding circuit 26 can be configured as an analog phase adjusting and adding circuit having a delay line (delay line), for example, or can be configured as a digital phase adjusting and adding circuit as a digital beam former. . Further, it can be configured as a phasing addition circuit using a CCD device.

  Incidentally, various embodiments can be adopted for the configuration that is closer to the apparatus body than the switching circuit 20. The configuration shown in FIG. 1 is an example.

  Next, the operation of the switching circuit 20 will be described with reference to FIGS.

  FIG. 3 conceptually shows a part of the 2D array transducer 16. Each cell corresponds to one vibration element. A plurality of subarrays are set on the 2D array transducer 16 with a square subarray shape pattern. In FIG. 3, in particular, subarrays S1 to S9 are shown. The subarrays S1 to S9 are closely connected to each other without a gap. In FIG. 3, an example of a group setting method is shown as a reference for the subarray S5. In the example shown in FIG. 3, five groups are set in the X direction. Each group is composed of five vibration elements arranged in the Y direction. Here, A, B, C, D, and E indicate identifiers of groups to which each vibration element belongs. The same applies to each figure described below.

  The subarray shape pattern shown in FIG. 3 is the most common, that is, a square subarray shape pattern. Further, the group shape pattern of each group shown in FIG. 3 is also a general one, and a linear shape extending in the Y direction is adopted. Such a grouping pattern (arrangement of a plurality of groups in the sub-array) is employed, for example, when an ultrasonic beam is scanned in the X direction as shown in FIG.

  FIG. 4 shows another example of the subarray shape pattern. Each of the sub-arrays S1 to S9 has a parallelogram shape as a whole that is inclined stepwise in an oblique direction. For example, when attention is paid to the sub-array S5, the grouping is performed as shown in the figure, and the group A is composed of five vibrating elements linearly aligned in the oblique direction, and this is the same for the other groups. However, in each stage in the Y direction, the X direction position of each group is shifted in parallel by one step. Incidentally, the same grouping pattern as that of the sub-array S5 is adopted for the other sub-arrays.

  By adopting the subarray shape pattern and group shape pattern as shown in FIG. 4, for example, when scanning an ultrasonic beam in a direction inclined by 45 degrees with respect to both the X direction and the Y direction, The thickness of the group can be limited to one vibration element. That is, it is possible to prevent the problem that the width of the vibrating portion is apparently increased in the beam scanning direction. This will be described in detail. In the present embodiment, the same delay time is given for each group. That is, the plurality of vibration elements constituting each group are connected in parallel at the time of transmission and at the time of reception, and constitute a single vibration part as a whole. If the width of such a vibrating portion is expanded in the beam scanning direction, side lobes are likely to occur as a result. On the other hand, as shown in FIG. 4, by appropriately setting the sub-array shape pattern and the group shape pattern, it is possible to prevent the width of the vibrating portion from being apparently increased. That is, the above problem can be solved or reduced.

  FIG. 5 shows various subarray shape patterns. At the same time, a grouping pattern is also shown. The sub-array shape pattern shown in (a) is the same as that shown in FIG. 3, and is used when the ultrasonic beam is scanned in the X direction. The subarray shape pattern shown in (b) is the same as the subarray shape pattern shown in (a) in its outer shape, but the grouping pattern inside thereof is different. That is, five groups are arranged in the Y direction, and each group includes five vibration elements arranged in the X direction. This is employed when the ultrasonic beam is scanned in the Y direction.

  The sub-array shape pattern shown in (c) is the same as that shown in FIG. The subarray shape pattern shown in (d) is obtained by shifting the subarray shape pattern shown in (b) above step by step in the X direction for each stage in the Y direction. The sub-array shape pattern shown in (d) is suitable for scanning an ultrasonic beam in the upward (left-down) direction toward the paper surface, similarly to the sub-array shape pattern shown in (c). is there.

  The subarray shape pattern shown in (e) has a form deformed in an oblique direction opposite to the subarray shape pattern shown in (c). Such a sub-array shape pattern is suitable for scanning an ultrasonic beam in a left upward (downward right) direction toward the paper surface.

  The subarray shape pattern shown in (f) has a form deformed in an oblique direction opposite to the subarray shape pattern shown in (d). Such a sub-array shape pattern is suitable for scanning an ultrasonic beam in a left upward (downward right) direction toward the paper surface, similarly to the sub-array shape pattern shown in FIG.

  Of course, some of the subarray shape patterns and the like shown in FIG. 5 are merely examples, and various other subarray shape patterns can be employed. That is, it is desirable to set the subarray shape pattern and the grouping pattern so that side lobes are not generated as much as possible according to the transmission / reception conditions, particularly the beam scanning direction, that is, the beam profile is improved. In addition, in order to simplify the configuration of the switching circuit 20 and simplify the control, the number of subarray shape patterns may be limited to, for example, about four. In that case, subarray shape patterns such as (a), (b), (c) (or (d)), and (e) (or (f)) shown in FIG. 5 can be adopted.

  In FIG. 6, the fluctuation region R for a certain subarray is indicated by a thick line. This variation region is defined by the largest outer edge of the region that the subarray can take when the shape of the subarray varies. That is, the fluctuation region R corresponds to a shape obtained by overlapping the shapes (a) to (f) shown in FIG. Here, reference numeral 100 denotes the most basic square subarray shape. For reference, the grouping pattern shown in FIG. 5C is shown.

  As understood from the form of the fluctuation region R shown in FIG. 6, the plurality of adjacent fluctuation regions R partially overlap each other. However, at the time of each transmission / reception, adjacent subarrays are closely connected to each other, and there is no overlap between them. The overlap will be described with reference to FIG.

  In FIG. 7, R <b> 1 to R <b> 4 represent four variable regions for four subarrays arranged vertically and horizontally. Incidentally, the fluctuation region R1 is represented by a solid line, the fluctuation region R2 is represented by a one-dot chain line, the fluctuation region R3 is represented by a two-dot chain line, and the fluctuation region R4 is represented by a broken line.

  Consider the vibration elements a to l in which the respective fluctuation regions partially overlap. The vibration elements a, b, and c belong to the fluctuation regions R1, R2, and R3, the vibration elements d, e, and f belong to the fluctuation regions R1, R2, and R4, and the vibration elements g, h, and i belong to the fluctuation regions R2, R3, and R3, respectively. The vibration elements j, k, and l belong to the fluctuation regions R1, R3, and R4.

  When attention is paid to the fluctuation region R1, the vibration elements a to f and j to l belong to the fluctuation region R1 (the vibration elements g to i do not belong), and the fluctuation region R1 further has its own characteristic. A plurality of vibration elements belong. Such a specific vibration element is composed of thirteen vibration elements, and they are densely packed in a rhombus centered on the central portion of the fluctuation region R1.

  FIG. 8 shows a comparative example. Here, the shape of the subarray is a square, and the shape is unchanged. When scanning an ultrasonic beam in an oblique direction, for example, a grouping pattern as shown in FIG. 8 is set. In this case, a plurality of vibration elements belonging to the group C exist in a multiple manner in the beam scanning direction (that is, the thickness of the vibration part C increases in the direction), and as a result, the profile of the ultrasonic beam Collapses and side lobes are likely to appear. On the other hand, according to the present embodiment, it is possible to set the subarray shape and grouping pattern as shown in FIG. 4, so that the problem that occurs in the case as shown in FIG. 8 is eliminated or reduced. It becomes possible.

  FIG. 9 shows another embodiment of the subarray shape, in which one subarray is constituted by 4 × 4 = 16 vibration elements. As shown in the figure, the 16 vibration elements constituting each subarray are grouped into four groups. In FIG. 9, each group is given a different hatching to identify each group. The numerical values shown in FIG. 9 indicate an angle (scanning azimuth) indicating the scanning direction of the ultrasonic beam.

  As shown in FIG. 9, the beam profile can be improved in any beam scanning direction by adaptively changing each sub-array (simultaneously grouping pattern) according to the scanning direction of the ultrasonic beam. Even when any of the subarray shape patterns shown in FIG. 9 is employed, the plurality of subarrays can be closely connected to each other. For example, when the scanning direction is 45 degrees, as shown in FIG. 4, a plurality of subarrays are closely connected to each other without a gap. The same applies to other scanning angles.

  However, one or a plurality of vibrating elements that do not substantially function may exist at the end of the 2D array transducer. In the above embodiment, no gap is generated between the plurality of subarrays, but one or a plurality of substantially non-functional vibrating elements may exist between the subarrays.

  The above-described variable setting method of the sub-array shape pattern can be applied to, for example, a 1.5D array transducer in which a plurality of transducer elements are two-dimensionally arranged in addition to the 2D array transducer.

  With reference to FIG. 11 and FIG. 12, some other variations will be described with respect to changes in the subarray shape pattern and grouping pattern. In FIG. 11, the subarray is composed of 4 × 4 vibrating elements.

  (A) shows a sub-array shape pattern when the beam scanning direction is 45 degrees. Each group is composed of four vibration elements orthogonal to the beam scanning direction (thick arrow). Each group has the same shape. (B) shows a sub-array shape pattern when the beam scanning direction is an angle smaller than 45 degrees. The subarray shown in (B) has the same subarray shape (outer shape) as the subarray shown in (A), but the number of vibrating elements constituting the group is not the same among the plurality of groups, and is non-linear. Groups A, B, and C are included. (C) shows a sub-array shape pattern when the beam scanning direction is an angle larger than 45 degrees. The subarray shown in (C) has the same subarray shape as the subarray shown in (A), but the number of vibrating elements constituting the group is not the same among the plurality of groups, and the non-linear group B , C, D are included. (D) shows another sub-array shape pattern when the beam scanning direction is an angle smaller than 45 degrees. The subarray shown in (D) has a different shape from the subarray shown in (A). In (D), the group shape is the same among a plurality of groups. (E) shows a sub-array shape pattern in the case where the beam scanning direction has a considerably small angle. The subarray shown in (E) has the same shape as the subarray shown in (D), but the number of vibration elements constituting the group is non-identical among a plurality of groups. Regardless of which subarray shape pattern is employed, a plurality of subarrays can be closely connected to each other.

  As described above, an excellent ultrasonic beam can be formed by changing both the subarray shape pattern and the group shape pattern in accordance with the beam scanning direction. In particular, the side lobes can be reduced more effectively by changing the number of vibrating elements constituting each group in accordance with the beam scanning direction.

  In the above embodiment, all of the plurality of vibration elements constituting each sub-array function as effective vibration elements (vibration elements that transmit and receive ultrasonic waves), but the beam scanning direction is a predetermined angle. In this case, one or a plurality of reactive vibration elements (vibration elements that do not transmit and receive ultrasonic waves) may be set in each subarray. This will be described with reference to FIG.

  In FIG. 12, the subarray is composed of 5 × 5 vibrating elements. (A) shows a subarray shape pattern when the beam scanning direction is 45 degrees (the same as the patterns shown in FIGS. 4, 5B and 6). Each group is constituted by a vibrating element row orthogonal to the beam scanning direction, and each vibrating element row is constituted by five vibrating elements. (B) shows a sub-array shape pattern when the beam scanning direction is 30 degrees. (C) shows a sub-array shape pattern when the beam scanning direction is 60 degrees. The subarrays shown in (B) and (C) have the same shape as the subarray shown in (A), but the subarrays shown in (B) and (C) have a plurality of non-linear groups. Have. (D) shows a subarray shape pattern when the beam scanning direction is 25 degrees. Here, the number of vibration elements constituting the group is the same and the shape is the same among the plurality of groups. On the other hand, (E) shows a sub-array shape pattern when the beam scanning direction is 15 degrees. The subarray shown in (E) has the same shape as the subarray shown in (D), but the grouping pattern is different between the two. (F) shows a sub-array shape pattern when the beam scanning direction is 20 degrees. The subarray shown in (F) has the same shape as the subarray shown in (D), but includes one reactive vibration element 102 in the subarray. (G) shows a subarray shape pattern when the beam scanning direction is 10 degrees. The subarray shown in (G) has the same shape as the subarray shown in (E), but includes four reactive vibration elements 102 in the subarray. As described above, the position and the number of the invalid vibration elements are variably set according to the beam scanning direction.

  Even when any of the subarray shape patterns shown in FIGS. 11 and 12 is employed, a plurality of subarrays can be closely connected to each other.

  As described above, according to the present invention, the ultrasonic beam profile can be improved. Therefore, there is an advantage that the image quality of the formed ultrasonic image can be improved.

It is a block diagram which shows the structure of the transmission / reception part in the ultrasonic diagnosing device which concerns on this invention. It is a block diagram which shows the specific structural example of the transmission / reception module shown in FIG. It is a figure which shows an example of a subarray shape pattern. It is a figure which shows the other example of a subarray shape pattern. It is a figure for comparing and explaining a plurality of subarray shape patterns. It is a figure which shows the fluctuation | variation area | region which exists for every subarray. It is a figure for demonstrating the overlap between several fluctuation | variation area | regions. It is a figure for demonstrating a comparative example. It is a figure which shows the various subarray shape pattern in other embodiment. 1 is a block diagram showing an overall configuration of an embodiment of an ultrasonic diagnostic apparatus according to the present invention. It is a figure for demonstrating embodiment with which the number of the vibration elements which comprise each group changes. It is a figure for demonstrating other embodiment from which the number of the vibration elements which comprise each group changes.

Explanation of symbols

  10 probe head, 12 device main body, 16 2D array transducer, 20 switching circuit, 24 transmission / reception module, 26 sub phasing addition circuit, 30 main phasing addition circuit, 32 transmission / reception control unit, S subarray, R fluctuation range.

Claims (22)

An array vibrator having a plurality of vibration elements arranged two-dimensionally;
A switching unit for setting a plurality of subarrays for the plurality of vibration elements;
A reception processing unit for processing a plurality of reception signals output from the array transducer;
Including
The ultrasonic diagnostic apparatus, wherein the switching unit changes a subarray shape pattern of at least one subarray in the array transducer. The ultrasonic diagnostic apparatus according to claim 1,
The ultrasonic diagnostic apparatus, wherein the switching unit changes each subarray shape pattern for the plurality of subarrays. The ultrasonic diagnostic apparatus according to claim 2,
An ultrasonic diagnostic apparatus, wherein the same subarray shape pattern is set for the plurality of subarrays. The ultrasonic diagnostic apparatus according to claim 1,
The ultrasonic diagnostic apparatus further includes a control unit that switches the subarray shape pattern according to a beam forming condition. The ultrasonic diagnostic apparatus according to claim 4.
The array transducer is a 2D array transducer in which a plurality of transducer elements are aligned in the X direction and the Y direction.
The ultrasonic diagnostic apparatus, wherein the beam forming condition includes a beam scanning direction on an XY plane. The ultrasonic diagnostic apparatus according to claim 1,
The switching unit further sets a plurality of groups for each of the subarrays,
Each group includes a plurality of vibration elements,
The reception processing unit processes a group reception signal output for each group in each subarray,
The switching unit further has a function of changing the group shape pattern of each group in accordance with the change of the subarray shape pattern. The ultrasonic diagnostic apparatus according to claim 6,
The ultrasonic diagnostic apparatus, wherein the number of vibration elements constituting each group is varied according to beam forming conditions. The ultrasonic diagnostic apparatus according to claim 7,
The ultrasonic diagnostic apparatus, wherein the beam forming condition includes a beam scanning direction. The ultrasonic diagnostic apparatus according to claim 6,
The ultrasonic diagnostic apparatus according to claim 1, wherein each subarray includes one or a plurality of ineffective vibration elements according to beam forming conditions. The ultrasonic diagnostic apparatus according to claim 6,
An ultrasonic diagnostic apparatus comprising: a control unit that switches the group shape pattern together with the subarray shape pattern according to beam forming conditions. The ultrasonic diagnostic apparatus according to claim 1,
The ultrasonic diagnostic apparatus, wherein the plurality of subarrays are closely connected to each other even when the subarray shape pattern is changed. The ultrasonic diagnostic apparatus according to claim 1,
A pattern variation region is defined for each subarray, whereby a plurality of pattern variation regions are defined on the array transducer,
The pattern variation region for each subarray corresponds to a region where a plurality of subarray shape patterns are combined,
The ultrasonic diagnostic apparatus, wherein the plurality of pattern variation areas have portions that partially overlap each other. The ultrasonic diagnostic apparatus according to claim 12, wherein
Each pattern variation region covers a plurality of vibration elements unique to each subarray and a plurality of vibration elements present in the overlapping portion. An array vibrator having a plurality of vibration elements;
A switching unit that sets a plurality of subarrays for the plurality of vibration elements, sets a plurality of groups for each subarray, and outputs a group reception signal for each group;
A reception processing unit that processes a plurality of group reception signals output from the switching unit;
A control unit for controlling the switching unit according to beam scanning conditions;
Including
The ultrasonic diagnostic apparatus, wherein the control unit controls the operation of the switching unit to change a subarray shape pattern of each subarray and to change a group shape pattern of each group. The ultrasonic diagnostic apparatus according to claim 14, wherein
The reception processing unit
A plurality of sub-phased and added circuits that execute a sub-phased and added process on a plurality of group reception signals output from each of the sub-arrays and output a sub-phased and added signal;
A main phasing and adding circuit that performs main phasing and addition processing on the plurality of sub phasing and addition signals output from the plurality of sub phasing and addition units;
An ultrasonic diagnostic apparatus comprising: The ultrasonic diagnostic apparatus according to claim 15, wherein
An ultrasonic diagnostic apparatus, wherein at least the array transducer and the switching unit are provided in a probe head. An array vibrator having a plurality of vibration elements;
A switching unit for setting a plurality of subarrays for the plurality of vibration elements;
A controller that controls the switching unit to adaptively change a sub-array shape pattern of each sub-array according to a beam scanning direction;
An ultrasonic diagnostic apparatus comprising: The ultrasonic diagnostic apparatus according to claim 17, wherein
Each of the subarray shape patterns is composed of a plurality of pattern elements,
Each said pattern element is comprised by the vibration element row | line | column arrange | positioned substantially linearly, The ultrasonic diagnostic apparatus characterized by the above-mentioned. The ultrasonic diagnostic apparatus according to claim 18, wherein
The ultrasonic diagnostic apparatus, wherein each of the vibration element arrays is substantially orthogonal to the beam scanning direction. The ultrasonic diagnostic apparatus according to claim 17, wherein
When the beam scanning direction is 0 degrees, 90 degrees, 180 degrees, and 270 degrees, the shape of each subarray is a quadrangle,
When the beam scanning direction is other than the angle, the ultrasonic diagnostic apparatus is characterized in that the shape of each of the subarrays is deformed from the square to become a parallelogram or a shape close thereto. The ultrasonic diagnostic apparatus according to claim 17, wherein
The control unit sets one or more reactive vibration elements in each subarray according to the beam scanning direction, and a plurality of effective vibration elements other than the one or more reactive vibration elements in each subarray. An ultrasonic diagnostic apparatus characterized in that a plurality of groups are set using a computer. The ultrasonic diagnostic apparatus according to claim 17, wherein
The control unit sets a plurality of groups in each subarray according to the beam scanning direction,
The control unit changes the group shape pattern of each group according to the beam scanning direction, and changes the number of vibrating elements constituting each group according to the beam scanning direction. Ultrasound diagnostic device.

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