JP4516340B2 - Ultrasonic diagnostic equipment - Google Patents

Description

  The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to operation control of a 1.25D type ultrasonic transducer.

  As types of ultrasonic transducers, 1D array transducers and 2D array transducers are known, but as intermediate types, 1.25D array transducers, 1.5D array transducers, etc. are also known. It has been.

  A conventional 1.25D array transducer is formed by arranging a plurality of vibration elements in the array direction, like the 1D array transducer, and each vibration element is divided into a plurality of elements in the elevation direction. The The number of divisions is 3 or 5, for example, but may be an even number. For example, in the case of the division number 3, it is composed of a central element and end element pairs on both sides thereof, and in the case of the division number 5, the central element and a first end element pair sandwiching the center element, and And a second end element pair provided on the outside thereof. Each end element pair is composed of two elements at symmetrical positions when viewed from the center position in the elevation direction.

  As described above, the 1.25D array transducer is configured as a plurality of vibrating elements, that is, element rows arranged in the array direction, and each element row is configured of a plurality of elements arranged in the elevation direction. In the conventional 1.25D array transducer, the presence / absence of the connection of the end element pairs and the number of connections cannot be individually switched for each vibration element. That is, the opening width in the elevation direction can be set only uniformly for all vibration elements. In the 1.5D array transducer, generally, the opening width in the array direction is variably set according to the depth of the focus point, and the opening width in the elevation direction is also variably set.

  The 1.5D array transducer controls the beam pattern electronically in the elevation direction as well as the array direction by performing delay control different from the central element for each of the end element pairs. It is. On the other hand, the 1.25D array transducer supplies a common transmission signal to each element operated in each vibration element, and processes reception signals from these elements together as one reception signal. Is.

JP-A-2-262800 JP-A-9-526 JP 2001-161689 A

  As described above, the conventional 1.25D array transducer has a problem that the opening width in the elevation direction cannot be individually set for each transducer element.

  The above-mentioned Patent Document 1 discloses an array transducer corresponding to a 1.25D array transducer, but the opening width in the elevation direction is fixed for the vibration element present at the end in the array direction. . In the first place, the configuration described in the patent document is to increase or decrease the size of the rectangular opening step by step while keeping the center position of the rectangular opening in the electronic sector scanning. Note that FIG. 5 of Patent Document 1 discloses a configuration in which a switch for selecting whether or not an element pair operates is provided for each vibration element. However, individual control of the operation of these switches, that is, each vibration is disclosed. There is no description about individually setting the opening in the elevation direction at the element position.

  Patent Document 2 described above discloses that the array transducer is operated in a time-sharing manner in the elevation direction. The received signal obtained by each time division operation is subjected to delay addition processing, that is, the array transducer functions as a 1.5D array transducer as a result. FIG. 7 of Patent Document 3 described above describes a configuration similar to that described in Patent Document 2.

  An object of the present invention is to make it possible to individually set the opening width in the elevation direction for each vibration element position in the array direction in the 1.25D array transducer.

  Another object of the present invention is to make it possible to set a favorable aperture shape at the time of transmission and at the time of reception in a 1.25D array transducer.

  Another object of the present invention is to set an appropriate transmission aperture and reception aperture corresponding to a continuous wave Doppler mode in a 1.25D array transducer.

  Another object of the present invention is to reduce the number of signal lines that pass through a cable and realize simple control in a 1.25D array transducer.

(1) The present invention provides an array transducer including a plurality of vibration elements arranged in the array direction, a switch circuit group including a plurality of switch circuits individually provided for each of the vibration elements, and the switch circuit group. An ultrasonic probe including a controller that switches and sets a switch operation pattern with respect to the plurality of vibration elements, and a cable having a plurality of signal lines provided corresponding to the plurality of vibration elements, and connected to the plurality of signal lines A transmission / reception unit, and a transmission / reception control unit that outputs a control signal to the controller, and an apparatus main body to which a cable of the ultrasonic probe is connected, It is configured as an element row composed of a plurality of elements arranged in an elevation direction orthogonal to the array direction, and each element row is provided at a central position in the elevation direction. One or a plurality of regular elements always connected to the signal line constituting the cable, and at least one element pair provided at symmetrical positions on both sides from the center position in the elevation direction, and selected as the signal line And at least one selection element pair connected to each other, and the controller outputs a signal individually controlling the operation of each switch circuit to each switch circuit. The circuit selects the presence or absence of connection to the signal line for each selection element pair included in the corresponding vibration element, and the array transducer can vary the opening size in the array direction , and the array direction non uniform operation type 1.25D array transducer that can be set individually the aperture size of the Jer base Shon direction for each vibration element position in There, characterized in that.

According to the above configuration, the switch circuit is individually provided for each vibration element, and each switch circuit connects one or a plurality of selection element pairs included in each vibration element to the signal line for the vibration element. Is selected. Therefore, even with a 1.25D array transducer, the opening width in the elevation direction can be individually set for each transducer element. That is, in the conventional 1.25D array transducer, only a uniform setting can be made for the opening size in the elevation direction at each vibration element position in the array direction. However, according to the above configuration, a non-uniform setting can be performed. The operation control of the switch circuit group is executed by a controller provided in the probe head based on a control signal from the apparatus main body side. Therefore, the two-dimensional transmission aperture shape and the reception aperture shape can be set as in the case of the 2D array transducer, and the number of signal lines constituting the probe cable is the number when the 1D array transducer is used (normally 100-200), it is only necessary to add a few control signal lines, so that the probe cable can be remarkably thin compared with the case of using a 1.5D array transducer or a 2D array transducer. Here, the number of control signal lines is, for example, 1-10, and can be reduced to one or several by serial transmission of control signals. It is desirable that the switch operation pattern be switched between the transmission period and the reception period.

  Preferably, the transmission / reception control unit makes the two-dimensional shape of the transmission aperture different from the two-dimensional shape of the reception aperture. According to this configuration, an optimal sound field can be formed individually for transmission and reception. In particular, the aperture shape at the time of transmission can be a circle or an ellipse, the aperture shape at the time of reception can be a rectangle or the like, and the aperture shape at the time of reception can be made larger than the aperture shape at the time of transmission. In general, each opening shape is axisymmetric with respect to the center line in the array direction passing through the center position in the elevation direction.

  Preferably, the transmission / reception control unit electronically scans the transmission aperture and the reception aperture in the array direction. Since the aperture size can be individually set for each vibration element, it is possible to perform electronic linear scanning in the array direction while maintaining the shape of each aperture.

  Preferably, the transmission / reception control unit simultaneously sets a transmission aperture and a reception aperture on the array transducer in the continuous wave Doppler mode, and makes the two-dimensional shape of the transmission aperture different from the two-dimensional shape of the reception aperture. In the continuous wave Doppler mode, the transmission aperture and the reception aperture are set simultaneously and side by side in the array transducer. However, according to the above configuration, the aperture width in the elevation direction can be set for each resonator element. The width or two-dimensional shape of each opening in the wave Doppler mode can be set as appropriate. For example, it is easy to make the reception aperture larger than the transmission aperture in the elevation direction. Note that an air gap zone (non-operating section) may be provided between the transmission opening and the reception opening to prevent acoustic wraparound.

  Preferably, the size of the reception aperture in the elevation direction is larger than the size of the transmission aperture in the elevation direction. Preferably, the transmission / reception control unit changes at least the two-dimensional shape of the transmission aperture according to the depth of the focus point.

  Preferably, the transmission / reception control unit outputs a code signal specifying a switch operation pattern as the control signal, and the controller includes a decoder for decoding the code signal. Preferably, the code signal is transmitted as serial data.

  According to the above configuration, since serial data is transmitted, the number of signal lines required for the transmission can be reduced, and basically the serial data can be transmitted through one signal line. The serial data is decoded, and a control signal for controlling the operation of each switch circuit is generated. When each vibration element is composed of three elements, that is, when it is composed of a constant element at the center and a pair of selection elements on both sides, the control signal supplied to each switch circuit is on / off of the switch. It can be a signal.

  If necessary, a signal line for a clock signal, a signal line for power supply, a signal line for ground, and the like are added. In this case, the 1.5D array vibrator and the 2D array vibrator are also used. The thickness of the probe cable can be made very thin as compared with the case of using.

  As described above, according to the present invention, in the 1.25D array transducer, the opening width in the elevation direction can be individually set for each vibration element position in the array direction. According to the present invention, it is possible to set a favorable opening shape at the time of transmission and at the time of reception. According to the present invention, it is possible to set an appropriate transmission aperture and reception aperture corresponding to the continuous wave Doppler mode. According to the present invention, the number of signal lines that pass through a cable can be reduced, and simple control can be realized.

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

  FIG. 1 shows a preferred embodiment of an ultrasonic diagnostic apparatus according to the present invention, and FIG. 1 is a block diagram thereof.

  The ultrasonic diagnostic apparatus includes a main body 10 and an ultrasonic probe. The ultrasonic probe includes a probe head 12 and a probe cable 14. Here, in this embodiment, the ultrasonic probe is used in contact with the surface of a living body, but the ultrasonic probe may be inserted into a body cavity.

  The probe head 12 has a 1.25D type array transducer 16. The array transducer 16 includes a plurality of vibration elements 18 aligned in the array direction (Y direction). For example, the array transducer 16 includes 100 or 200 transducer elements 18. Each vibration element 18 is divided into five elements 18a to 18c in the example shown in FIG. Here, the central element 18a is an element that is always connected to the signal line 100 for the vibration element 18, and two element pairs 18b and 18c are provided on the left and right sides with the center as the center element 18a. The element pair 18b is composed of two elements that are equidistant from the center in the X direction, which is the elevation direction, and the same applies to the element pair 18c. The signal line 102 is connected to the element pair 18b, and the signal line 104 is connected to the element pair 18c. Whether the signal lines 102 and 104 are connected to the signal line 100 is switched by the switch circuit 20.

  As described above, the array transducer 16 includes the plurality of vibration elements 18 aligned in the array direction, and each vibration element 18 includes the plurality of elements 18a to 18c aligned in the elevation direction. Then, an element pair to which a signal is supplied or a signal is output together with the central element 18a is selected by pair selection of the switch circuit 20 described below. Incidentally, the signal lines 100, 102, 104 (and the switch circuit 20 below) are provided for each vibration element 18.

  An electronic circuit 32 is provided in the probe head 12. The electronic circuit 32 has a switch circuit group including a plurality of switch circuits 20. A corresponding switch circuit 20 is provided for each vibration element 18. As described above, the switch circuit 20 selects whether or not to connect the signal lines 102 and 104 for each pair to the original signal line 100 for the vibration element. For this reason, the switch circuit 20 has two switches 22A and 22B provided corresponding to two element pairs. In the present embodiment, the switch circuit 20 includes a signal processing circuit 24. The signal processing circuit 24 is provided as necessary, and performs processing such as amplification on the transmission signal and processing such as amplification on the reception signal. A signal line 108 for each vibration element is provided for each switch circuit 20, and the signal line 108 is connected to the signal line 100 via the signal processing circuit 24.

  A decoder 26 as a controller is provided in the probe head 12. When a code signal 109 as a control signal is input from the main body 10 side, the decoder 26 decodes the code signal and generates a signal for controlling the operation of each switch circuit 20. Here, the code signal is serially transmitted, that is, only one signal line 109 for transmitting the code signal is basically provided.

  However, a clock signal for operating the decoder 26 may be serially transmitted as necessary, or a power source for operating the decoder 26 may be supplied.

  In the example shown in FIG. 1, each vibration element 18 has two element pairs 18 b and 18 c, and two switches 22 </ b> A and 22 b are provided in each switch circuit 20 correspondingly. The control signal 106 supplied from the decoder 26 to each switch circuit 20 may be, for example, two signal lines for controlling on / off of the operation of each switch 22A, 22B. When each vibration element 18 has only one element pair in addition to the central element 18a, only one signal line may be provided to each switch circuit 20, that is, a signal for switching on / off of the switch with respect to the signal line. Should be given.

  As can be understood from the above configuration, the probe cable 14 includes the control signal line 109 and a small number of necessary signals in addition to the plurality of signal lines 108 provided corresponding to the plurality of vibration elements 18. A signal line is included. Therefore, the probe cable 14 can be configured by adding a few signal lines in addition to the number of signal lines in the case of using the conventional 1D array vibrator, and the 1.5D array vibrator and the 2D array vibrator There is an advantage that the thickness of the probe cable 14 can be sufficiently reduced as compared with the case of using. That is, there is an advantage that the probe cable 14 can be thinned to improve the handleability of the probe head 12 and the opening width in the elevation direction can be freely set for each vibration element as will be described later.

  The main body 10 has a transmission / reception unit 28 connected to a plurality of signal lines 108. The transceiver 28 has a plurality of transmitters and receivers provided corresponding to the plurality of vibration elements 18. The transmission / reception control unit 30 controls the operation of the transmission / reception unit 28, generates the code signal, and supplies it to the decoder 26. The transmission control unit 30 generates a control signal to be supplied to each signal processing circuit 24 as necessary. Such a control signal is transmitted using the signal line 107.

  In the present embodiment, since the 1.25D array transducer is configured, similarly to the conventional 1.25D array transducer, the transmission / reception aperture width in the elevation direction according to the depth of the ultrasonic focus point. Can be variably set. Similarly to the normal 1D array transducer, the transmission / reception aperture width can be variably set in the array direction. Therefore, the aperture width can be freely set in both the array direction and the elevation direction. In other words, there is an advantage that the two-dimensional shape of the transmission aperture and the reception aperture can be freely set according to the depth of the focus point. is there. However, each opening has a symmetrical shape with respect to the center line in the array direction passing through the center point in the elevation direction.

  Further, according to the configuration according to the present embodiment, by providing an appropriate code signal to the decoder 26 between the transmission period and the reception period, the switch operation pattern at the time of transmission and the switch operation pattern at the time of reception There is an advantage that the transmission aperture shape at the time of transmission and the reception aperture shape at the time of reception can be set independently.

  Next, variable setting of the transmission aperture and the reception aperture will be described with reference to FIGS.

  2A shows a transmission aperture 44 set on the array transducer 16 and FIG. 2B shows a reception aperture 46 set on the array transducer 16. The openings 44 and 46 are alternately formed and electronically scanned in the array direction according to an electronic linear scanning method. As shown in FIG. 2, the transmission aperture 44 has a circular or oval shape as a whole, while the reception aperture 46 has a rectangular shape such as a rectangle or a rectangle. As described above, according to the present embodiment, the shape of the opening can be determined independently at the time of transmission and at the time of reception, that is, the two-dimensional shape of the opening that provides the best transmission sound field at the time of transmission is obtained. On the other hand, at the time of reception, a wider opening area can be set so that as many echo signals as possible can be received. In FIG. 2, the reception opening 46 has a rectangular shape and has a size larger than that of the transmission opening 44. However, the shapes of the transmission opening 44 and the reception opening 46 can be matched, and the size thereof depends on the situation. It can be set accordingly.

  As described above, it is desirable to variably set the aperture width in the array direction and the elevation direction in accordance with the depth of the focus point when performing electronic linear scanning as described above.

  FIG. 3 shows a transmission / reception opening 48 when the array transducer 16 is driven by electronic sector scanning. The transmission / reception opening 48 has a rhombus or oval shape as a whole, that is, the opening width in the elevation direction is narrowed at the end, thereby reducing the side lobe. Incidentally, when performing electronic sector scanning, the shape of the transmission aperture and the shape of the reception aperture may be different. For example, the aperture shape shown in FIG. 3 may be adopted at the time of transmission, and the entire array transducer 16 may be the aperture at the time of reception. In order to reduce the influence of side lobes at the time of reception, gain adjustment or the like may be performed on the reception signal corresponding to each vibration element, thereby electronically weighting.

4 and 5 show an array transducer 40 in which three elements are arranged in the elevation direction.
, 42 are shown. When such a configuration is adopted, each vibration element is composed of a central element and a pair of element pairs provided on both sides thereof, and each element pair is connected to the central element by providing an on / off signal. Is switched. In the example shown in FIG. 4, the aperture width is set over the entire array transducer 40 in the array direction on the premise of electronic sector scanning, but the maximum aperture is set at the center of the array direction in the elevation direction. However, only the central element is operating at both end portions 50B.

  The example shown in FIG. 5 shows a transmission aperture 52 and a reception aperture 54 when the array transducer 42 is operated according to the continuous wave Doppler method (CW Doppler method). In the continuous wave Doppler method, an ultrasonic wave as a continuous wave is continuously emitted from the transmission opening 52, and on the other hand, a reflected wave continuously reflected from the living body is received by the reception opening 54. In this embodiment, since the opening width in the elevation direction can be set for each vibration element, as shown in FIG. 5, the opening width in the elevation direction is reduced for the transmission opening 52, With respect to the reception opening 54, the opening width in the elevation direction can be increased. Incidentally, beam spearing or the like can be performed, and in that case, Doppler information at the intersection position of the transmission beam and the reception beam is observed with high accuracy.

  As described above, in the array transducer, one or a plurality of common elements and one or a plurality of selection element pairs are provided, and the operation of one or a plurality of selection element pairs can be freely performed for each vibration element. Since it is configured so that it can be set, although there are certain restrictions, it is possible to realize a transmission aperture and a reception aperture having various shapes like a 2D array transducer, and on the other hand, a probe cable is configured. There is an advantage that the number of signal lines can be remarkably reduced as compared with a 2D array transducer or the like. Furthermore, in the above embodiment, since the switch operation pattern can be switched between transmission and reception, each sound during transmission and reception can be switched between the two-dimensional shape of the transmission aperture and the two-dimensional shape of the reception aperture. The field can be optimized, and as a result, the image quality of the ultrasonic image can be improved. Furthermore, in the above embodiment, only a few (for example, 2 to 5) signal lines need to be added for controlling the electronic circuit in the probe head, so that the advantage of the freedom of the opening shape as described above can be enjoyed. However, at the same time, there is an advantage that the diameter of the probe cable can be reduced. In addition, each opening shape shown above is an example of course, and various opening shapes are employable. In particular, it is desirable to change the aperture shape or the aperture size every time the depth of the focus point is different.

1 is a block diagram showing a preferred embodiment of an ultrasonic diagnostic apparatus according to the present invention. It is a figure which shows the transmission opening and receiving opening in the case of performing electronic linear scanning. It is a figure which shows the transmission / reception opening in the case of performing electronic sector scanning. It is a figure which shows the transmission / reception opening set in the array vibrator | oscillator which has three elements in an elevation direction. FIG. 5 is a diagram showing a case where a transmission aperture and a reception aperture are set in a continuous wave Doppler method using an array transducer similar to the array transducer shown in FIG. 4.

Explanation of symbols

  10 body, 12 probe head, 14 probe cable (probe cable), 16 array transducer (1.25D transducer), 18 transducer, 20 switch circuit, 22A, 22B switch, 24 signal processing circuit, 26 decoder, 28 Transmission / reception unit, 30 Transmission / reception control unit.

Claims (8)

An array transducer composed of a plurality of vibration elements arranged in the array direction, a switch circuit group composed of a plurality of switch circuits individually provided for each of the vibration elements, and a switch operation pattern for the switch circuit group An ultrasonic probe including a controller for switching setting and a cable having a plurality of signal lines provided corresponding to the plurality of vibration elements;
A transmission / reception unit connected to the plurality of signal lines; and a transmission / reception control unit that outputs a control signal to the controller; and an apparatus main body to which a cable of the ultrasonic probe is connected;
Including
Each of the vibrating elements is configured as an element row composed of a plurality of elements arranged in an elevation direction orthogonal to the array direction,
Each element sequence is
One or more common elements provided at a central position in the elevation direction and always connected to a signal line constituting the cable;
At least one element pair provided at a symmetrical position on both sides from the center position in the elevation direction, and at least one element pair for selection selectively connected to the signal line;
Consists of
The controller outputs a signal for individually controlling the operation of each switch circuit to each switch circuit, whereby each switch circuit performs the selection element pair included in the corresponding vibration element. Select whether to connect to the signal line,
A non-uniform operation type 1.25D array in which the aperture size of the array transducer can be varied in the array direction , and the aperture size in the elevation direction can be individually set for each vibration element position in the array direction. An ultrasonic diagnostic apparatus characterized by being a vibrator . The apparatus of claim 1.
The ultrasonic diagnostic apparatus, wherein the transmission / reception control unit makes the two-dimensional shape of the transmission aperture different from the two-dimensional shape of the reception aperture. The apparatus of claim 2.
The ultrasonic diagnostic apparatus, wherein the transmission / reception control unit electronically scans the transmission aperture and the reception aperture in an array direction. The apparatus of claim 1.
The transmission / reception control unit simultaneously sets a transmission aperture and a reception aperture on the array transducer in continuous wave Doppler mode,
2. An ultrasonic diagnostic apparatus characterized in that a two-dimensional shape of the transmission aperture is different from a two-dimensional shape of the reception aperture. The apparatus of claim 4.
An ultrasonic diagnostic apparatus, wherein a size of the reception aperture in the elevation direction is larger than a size of the transmission aperture in the elevation direction. The apparatus of claim 1.
The ultrasonic diagnostic apparatus, wherein the transmission / reception control unit varies at least the two-dimensional shape of the transmission aperture according to the depth of the focus point. The apparatus of claim 1.
The transmission / reception control unit outputs a code signal specifying a switch operation pattern as the control signal,
The ultrasonic diagnostic apparatus, wherein the controller includes a decoder that decodes the code signal. The apparatus of claim 7.
The ultrasonic diagnostic apparatus, wherein the code signal is transmitted as serial data.

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