JP4128821B2 - Ultrasonic diagnostic equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ultrasonic diagnostic apparatus having a continuous wave Doppler mode, and in particular, an ultrasonic diagnosis that executes a continuous wave Doppler mode using an array transducer including a plurality of vibration elements aligned in an electronic scanning direction and an elevation direction. Relates to the device.
[0002]
[Prior art]
In the ultrasonic diagnostic apparatus, an ultrasonic wave is transmitted from an array transducer including a plurality of ultrasonic vibration elements to a target tissue, and a reflected wave thereof is received.
[0003]
A generally used array transducer is called a 1D array transducer, and a plurality of transducer elements are arranged in a line. Transmission / reception control is performed for each vibration element. Thereby, an ultrasonic beam is formed, and the ultrasonic beam is electronically scanned in the arrangement direction of the vibration elements.
[0004]
In contrast to this, a so-called 1.5D array vibration in which a plurality of vibration elements are arranged not only as one vibration element array in the electronic scanning direction but also in a direction orthogonal to the electronic scanning direction, that is, in the elevation direction. The child, 1.75D array transducer, has attracted attention.
[0005]
Although the 1.5D array transducer cannot deflect the beam in the elevation direction, it can adjust the beam pattern. The 1.75D array transducer can also deflect the ultrasonic beam in the elevation direction. Hereinafter, the 1.5D array transducer and the 1.75D array transducer will be described using the 1.5D array transducer as a representative.
[0006]
[Problems to be solved by the invention]
By the way, a method for obtaining a good measurement accuracy by executing a continuous wave Doppler mode using a 1.5D array transducer is desired. That is, in the continuous wave Doppler mode, it is necessary to divide a plurality of vibration elements into a transmission element group and a reception group. However, if the 1.5D array transducer is simply divided into left and right in the electronic scanning direction, A sufficient transmission aperture and reception aperture cannot be obtained in the electronic scanning direction. If the transmission aperture and the reception aperture are not sufficient in the electronic scanning direction, the ultrasonic beam tends to be difficult to narrow and spread, so that the azimuth resolution of the beam is deteriorated and the sensitivity is lowered.
[0007]
An object of the present invention is to provide an ultrasonic diagnostic apparatus capable of sufficiently securing a transmission aperture and a reception aperture in the electronic scanning direction in the continuous wave Doppler mode. Another object of the present invention is to provide an ultrasonic diagnostic apparatus capable of improving the azimuth resolution of an ultrasonic beam.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, an ultrasonic diagnostic apparatus according to the present invention is an ultrasonic diagnostic apparatus having a continuous wave Doppler mode, which is orthogonal to an electronic scanning direction and an electronic scanning direction, which are directions in which an ultrasonic beam is electronically scanned. An array transducer composed of a plurality of transducer elements aligned in the elevation direction, and a transmission / reception controller that controls operations of the plurality of transducer elements, and in the continuous wave Doppler mode, on the array transducer, at least one transmission transducer element group aligned in electronic scanning direction, the electronic scanning aligned in a direction and at least one receiving transducer element group is Ru is set in different positions in the elevation direction.
[0009]
With this configuration, in the 1.5D array transducer and the 1.75D array transducer, the transmission vibration element group and the reception vibration element group are arranged at different positions in the elevation direction, so that the transmission aperture and reception in the electronic scanning direction are arranged. In setting the aperture, the transmission aperture and the reception aperture can be sufficiently secured without interfering with each other. In addition, the azimuth resolution of the ultrasonic beam can be improved.
[0010]
Further, each of the transmission vibration element groups is a transmission vibration element array including all of a plurality of vibration elements aligned in the electronic scanning direction, and each of the reception vibration element groups is aligned in the electronic scanning direction. Oh Ru by the receiving vibrating element array composed of all of the plurality of transducer elements.
[0011]
With this configuration, in the 1.5D array vibrator and the 1.75D array vibrator, the transmission vibration element row and the reception vibration element row are set for each vibration element row, and the length of the 1.5D array vibrator in the electronic scanning direction is set. It becomes possible to widen the transmission aperture and the reception aperture. All of the plurality of vibration elements aligned in the electronic scanning direction may be substantially all for transmission / reception control, and may include dummy elements or the like.
[0012]
In addition, it is preferable that the array transducer includes a plurality of ground electrodes divided for each transmission vibration element array and for each reception vibration element array. With this configuration, crosstalk between signals can be suppressed.
[0013]
Moreover, it is preferable that the transmission vibration element array and the reception vibration element array are alternately set in the elevation direction.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram of an ultrasonic diagnostic apparatus 40 using a 1.5D array transducer. In the following description, the case of the continuous wave Doppler mode will be mainly described, and the case of the B mode will be described later.
[0015]
In FIG. 1, a probe 41 is an ultrasonic probe that transmits ultrasonic waves and receives echoes, and is used, for example, in contact with the body surface of a subject. In the probe 41, an array transducer 42 composed of a plurality of vibration elements 43 aligned in the electronic scanning direction and the elevation direction is provided. An ultrasonic beam is formed using the array transducer 42, and the ultrasonic beam is electronically scanned. As the electronic scanning method, for example, electronic linear scanning or electronic sector scanning can be used.
[0016]
In the array transducer 42, for example, 128 vibrating elements are arranged in the electronic scanning direction and each form a vibrating element array. For example, three rows of vibration element rows are arranged in the elevation direction. Of course, the number of vibration elements other than 128 or the number of columns of 3 or more may be used.
[0017]
The switching matrix 44 is a switch circuit that switches a connection relationship between each vibration element 43 of the array vibrator 42 and each channel of the transmission circuit 48 or each channel of the reception circuit 50 under the control of the control unit 52 described later. It is. The switching of the connection relationship is performed according to switching between the continuous wave Doppler mode and the B mode. Also, connection control may be switched in opening control in each mode.
[0018]
FIG. 2 shows the connection relationship in the case of continuous wave Doppler mode. The 1.5D array transducer 43 is shown as viewed from the drive electrode side of each transducer element 43. As shown in the figure, each vibration element 43 constituting the center vibration element array is connected to a transmission circuit 48. In addition, each vibration element 43 constituting each vibration element array on both sides of the central array is connected to the same receiving circuit 50 even if the vibration element arrays are different.
[0019]
That is, the center vibration element array is set as a transmission vibration element array 72 in which all of the vibration elements arranged in the electronic scanning direction, for example, 128 vibration elements in the above example are used for transmission. In addition, the respective vibration element rows on both sides of the central row are set as reception vibration element rows 74 and 76 in which all the vibration elements arranged in the electronic scanning direction are used for reception. All the vibration elements are sufficient if they are substantially all for transmission / reception control, and may include dummy elements or the like. In that case, the dummy element is not used for transmission or reception.
[0020]
The transmission / reception unit 46 includes a transmission circuit 48 and a reception circuit 50. Under the control of a transmission / reception control circuit 54 described later, the transmission / reception unit 46 forms an ultrasonic beam for continuous wave Doppler measurement and outputs a reception signal. Circuit. More specifically, the transmission circuit 48 is a circuit that supplies a delayed transmission signal for each vibration element 43 of the transmission vibration element array 72, and has a function as a so-called transmission beam former. The reception circuit 50 amplifies echo signals from the respective vibration elements 43 of the reception vibration element arrays 74 and 76 by a preamplifier, and performs a process of adjusting a phase difference of signals between the respective channels using a reference signal in the quadrature detection circuit. A circuit that outputs a received signal to the signal processing unit 56 and has a function as a so-called reception beamformer.
[0021]
The signal processing unit 56 includes a B-mode signal processing circuit 58 and a Doppler signal processing circuit 60 connected in parallel. The Doppler signal processing circuit 60 is composed of an A / D converter, an FFT calculator, and the like, and is a circuit that analyzes the frequency spectrum of Doppler information included in the received signal of the ultrasonic beam for Doppler measurement. The result of the signal processing is output to the display processing unit 62.
[0022]
The display processing unit 62 is a circuit that performs necessary processing on the output of the Doppler signal processing circuit 60 to form a Doppler waveform image or the like, and can be configured by a so-called digital scan converter (DSC) or various image processing circuits. . The formed Doppler waveform image is output to the display 64.
[0023]
The input unit 66 is connected to a control unit 52 described later, and is a switch, a keyboard, a trackball, or the like on which a user selects a function of the ultrasonic diagnostic apparatus 40 and inputs necessary data. For example, the user can select a continuous wave Doppler mode or a B mode as a function using a selection switch or the like.
[0024]
The control unit 52 is a controller that is connected to each component of the ultrasonic diagnostic apparatus 40 and performs control thereof. For example, the transmission / reception control circuit 54 has a function of controlling the transmission / reception unit 46 based on a reference clock. Further, the connection between each transducer element and the transmission / reception unit 46 by the switching matrix 44 according to a change in function between the continuous wave Doppler mode and the B mode, for example, by selection from the input unit 66 or automatic selection. Control relationship switching.
[0025]
As described above, in the continuous wave Doppler mode, the 1.5D array transducer 42 is arranged in the electronic scanning direction as long as the center vibration element array is set as the transmission vibration element array 72 and the number of transmission circuits is allowed. All the vibration elements are used for transmission. That is, when the number of transmission circuits is larger than the number of vibration elements constituting the transmission vibration element array, all vibration elements are used for transmission, and when the number is small, as many vibration elements as the number of transmission circuits allow are used for transmission. Used. Further, the vibration element rows on both sides of the central row are set as reception vibration element rows 74 and 76, and all the vibration elements arranged in the electronic scanning direction are used for reception as long as the number of reception circuits allows. That is, when the number of receiving circuits is larger than the number of vibrating elements constituting the receiving vibrating element array, all vibrating elements are used for reception, and when the number is small, as many vibrating elements as the number of receiving circuits allow are received. Used. Therefore, the transmission vibration element array and the reception vibration element array are set in units of vibration element arrays, the transmission aperture is widened in the electronic scanning direction of the 1.5D array transducer as much as the number of transmission circuits allows, and as long as the number of reception circuits allows. It is possible to widen the reception aperture, and it is possible to obtain highly sensitive Doppler information with good azimuth resolution of the ultrasonic beam.
[0026]
Here, the case of the B mode of the ultrasonic diagnostic apparatus 40 will be described. When the function is switched to the B mode, each vibration element 43 is connected to the transmission circuit 48 at the time of transmission and to the reception circuit 50 at the time of reception by the switching matrix 44 under the control of the control unit 52. Here, each vibration element constituting the vibration element row in the central row is connected to the transmission circuit and reception circuit corresponding to the central row, and each vibration element constituting each vibration device row on both sides of the central row is associated with the central row. Are connected to separate transmitter and receiver circuits.
[0027]
The transmitter / receiver 46 forms an ultrasonic beam for tomographic images by transmitting / receiving ultrasonic waves and outputs a reception signal. At this time, the transmission / reception control by the transmission circuit and reception circuit corresponding to the central column and the transmission / reception control by the transmission circuit and reception circuit corresponding to both side columns of the central column are, for example, transmission delay control and reception phase difference so as to adjust the beam pattern. Control is performed. The B-mode signal processing circuit 58 performs processing such as envelope amplitude detection and logarithmic compression of the input received signal, and the output is subjected to processing such as coordinate conversion and data interpolation in the display processing unit 62, so that a B-mode tomographic image is obtained. Is formed. The formed B-mode tomographic image is output to the display 64.
[0028]
FIG. 3 is a diagram for explaining the arrangement of the ground electrodes 78 of the 1.5D array transducer 42 according to the embodiment. The 1.5D array transducer 42 is shown as seen from the ground electrode side. As shown in the figure, each ground electrode 78 is divided for each vibration element row, and the ground electrode corresponding to the transmission vibration element row in the center row is connected to GND 1, and each reception vibration element row in both side rows of the center row. Each ground electrode corresponding to is connected to GND2 different from GND1. With this configuration, crosstalk between signals can be suppressed in the continuous wave Doppler mode.
[0029]
FIG. 4 is a diagram showing a 1.5D array transducer 42 according to another embodiment. The 1.5D array transducer 42 is shown as viewed from the drive electrode side of each vibration element 43 as in FIG. In the 1.5D array transducer 42 of this embodiment, each vibration element array on both side columns of the central column is a reception vibration element array 74 that uses all the vibration elements aligned in the electronic scanning direction for reception as in FIG. , 76, but the vibration element row 73 in the center row is different from the case of FIG. That is, the vibrating element row 73 in the central row uses the vibrating elements in the central region 80 among the vibrating elements aligned in the electronic scanning direction for transmission, and other regions on both sides of the central region 80 along the electronic scanning direction. Each of the vibrating elements is not used for transmission or reception as an invalid element. That is, each vibration element aligned in the central region 80 is used as the transmission vibration element group 81.
[0030]
Also in this configuration, since the transmission vibration element group 81 and the reception vibration element rows 74 and 76 are arranged at different positions in the elevation direction, the transmission aperture and the reception aperture in the electronic scanning direction interfere with each other. In that sense, the transmission aperture and the reception aperture can be sufficiently secured. In addition, the azimuth resolution of the ultrasonic beam can be improved.
[0031]
In addition, the element described as the invalid element in FIG. 4 may be used as an auxiliary receiving vibration element instead of the invalid element. Also in this case, the transmission vibration element group 81 and the reception vibration element rows 74 and 76 do not interfere with each other in setting the transmission aperture and the reception aperture in the electronic scanning direction, and in that sense, the transmission aperture and the reception aperture Can be secured sufficiently.
[0032]
The width of the central region 80 occupied by the transmitting vibration element group 81 can be set as long as the grating lobe does not adversely affect the array transducer 42. That is, as long as the grating lobe does not adversely affect, a plurality of vibration elements arranged in the electronic scanning direction can be set separately for transmission and reception. Further, the region occupied by the transmission vibration element group 81 is not limited to the central region, and may be a region that is shifted to the left or right.
[0033]
FIG. 5 is a diagram for explaining the setting relationship of each vibration element when the 1.75D array transducer 82 is used in another embodiment. The 1.75D array transducer 82 shows an example having five rows of vibration elements in the elevation direction, and the figure is shown as seen from the drive electrode side of each vibration element. As shown in the figure, each vibration element array is alternately connected to the transmission circuit 48 and the reception circuit 50 every other line. That is, the transmission vibration element rows 84 and 86 and the reception vibration element rows 88, 90, and 92 are alternately set for each vibration element row, and all of the vibration elements 43 constituting the transmission vibration element row are used for transmission. All of the vibration elements 43 constituting the vibration element array are used for reception. Therefore, the size of the transmission aperture and the reception aperture can be widened over the entire length of the 1.75D array transducer 82 in the electronic scanning direction.
[0034]
When the number of transmitting circuits is smaller than the number of vibrating elements constituting the transmitting vibrating element array, as many vibrating elements as the number of transmitting circuits allow are used for transmission, and the number of receiving circuits is equal to the receiving vibrating element array. If the number is less than the number of vibration elements to be configured, the number of vibration elements as many as the number of reception circuits allows is used for reception. In addition, a plurality of vibration elements arranged in the electronic scanning direction can be distributed and set for transmission and reception as long as the grating lobe does not adversely affect.
[0035]
In addition to the alternating arrangement setting shown in FIG. 5, for example, it is possible to perform settings such as arranging two transmission vibration element rows in succession and then arranging one or two reception vibration element rows. Also, a 1.75D array transducer in which a number of vibration element rows other than five rows are arranged in the elevation direction can be used. Further, the number of transmission vibration element rows and the number of reception vibration element rows can be the same.
[0036]
Similarly to the arrangement of the ground electrode of the 1.75D array transducer, as described with reference to FIG. 3, the ground electrode is divided for each transducer element row, and each ground electrode corresponding to each transmission transducer element row is connected to GND 1. Then, each ground electrode corresponding to each receiving vibration element array can be connected to GND 2 different from GND 1.
[0037]
【The invention's effect】
According to the ultrasonic diagnostic apparatus of the present invention, it is possible to sufficiently secure the transmission aperture and the reception aperture in the electronic scanning direction in the continuous wave Doppler mode.
[Brief description of the drawings]
FIG. 1 is a block diagram of an ultrasonic diagnostic apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram for explaining a setting relationship between a transmission vibration element array and a reception vibration element array of a 1.5D array transducer in continuous wave Doppler mode in the embodiment.
FIG. 3 is a diagram illustrating the arrangement of ground electrodes of the 1.5D array transducer according to the embodiment.
FIG. 4 is a diagram illustrating a setting relationship between a transmission vibration element array and a reception vibration element array of a 1.5D array transducer according to another embodiment.
FIG. 5 is a diagram illustrating a setting relationship between a transmission vibration element array and a reception vibration element array of a 1.75D array transducer in continuous wave Doppler mode in the embodiment.
[Explanation of symbols]
40 Ultrasonic Diagnostic Device, 41 Probe, 42 1.5D Array Vibrator, 43 Vibrating Element, 44 Switching Matrix, 48 Transmitting Circuit, 50 Receiving Circuit, 52 Control Unit, 54 Transmission / Reception Control Circuit (Transmission / Reception Control Unit), 60 Doppler signal processing circuit, 72, 84, 86 transmission vibration element array, 74, 76, 88, 90, 92 reception vibration element array, 78 ground electrode, 81 transmission vibration element group, 82 1.75D array transducer.

Claims (3)

In an ultrasonic diagnostic apparatus having a continuous wave Doppler mode,
An array transducer composed of a plurality of vibration elements aligned in an electronic scanning direction in which an ultrasonic beam is electronically scanned and an elevation direction orthogonal to the electronic scanning direction, and transmission / reception control for controlling operations of the plurality of vibration elements And
With
In the continuous wave Doppler mode, at least one transmission vibration element group aligned in the electronic scanning direction and at least one reception vibration element group aligned in the electronic scanning direction on the array transducer are in the elevation direction. It is set to different positions in,
further,
Each of the transmission vibration element groups is a transmission vibration element array configured by all of a plurality of vibration elements aligned in the electronic scanning direction, and each of the reception vibration element groups includes a plurality of alignment elements in the electronic scanning direction. ultrasonic diagnostic apparatus according to claim Oh Rukoto in configured receiving vibrating element array by the whole of the vibrating element. The ultrasonic diagnostic apparatus according to claim 1,
The array transducer, ultrasound diagnostic apparatus according to claim Rukoto comprising a plurality of ground electrodes divided the each transmission vibrating element row and per each received vibration element array. The ultrasonic diagnostic apparatus according to claim 1 ,
The transmission and vibrating element row, the receiving vibrating element array and an ultrasonic diagnostic apparatus according to claim Rukoto set alternately to the elevation direction.

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