JP2004057460A - Ultrasonic diagnostic instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To sufficiently secure a transmission opening and a reception opening in an electronic scanning direction concerning the continuous wave Doppler mode of an ultrasonic diagnostic instrument. <P>SOLUTION: The transmission vibrating element arrays 84, 86 and the reception vibrating element arrays 88, 90, 92 of a 1.75D array vibrator 82 in a continuous wave Doppler mode are set so as to be arranged by every other array, and respectively connected to a transmitting circuit 48 and a receiving circuit 50. That is, the transmission and reception vibrating element arrays are set with the vibration element array as a unit, whole vibrating elements 43 for constituting the transmission vibrating element arrays are used for transmission and whole vibrating elements 43 for constituting the reception vibrating element arrays are for reception. Thus, a size of the transmission opening and the reception opening is widely available to the whole length in the electronic scanning direction of the 1.75D array vibrator 82. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ultrasonic diagnostic apparatus having a continuous-wave Doppler mode, and more particularly to an ultrasonic diagnostic apparatus that performs a continuous-wave Doppler mode using an array transducer including a plurality of vibrating elements arranged in an electronic scanning direction and an elevation direction. Equipment related.
[0002]
[Prior art]
In an ultrasonic diagnostic apparatus, an ultrasonic wave is transmitted from a transducer array including a plurality of ultrasonic vibration elements to a target tissue, and a reflected wave is received.
[0003]
A commonly used array vibrator is called a 1D array vibrator, and a plurality of vibrating elements are arranged in a line. Then, 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]
On the other hand, a so-called 1.5D array vibration in which a plurality of vibrating elements are not only arranged as a vibrating element row in the electronic scanning direction but also arranged in a direction orthogonal to the electronic scanning direction, that is, a plurality of rows in the elevation direction. Transducers and 1.75D array transducers are receiving attention.
[0005]
The 1.5D array transducer cannot deflect the beam in the elevation direction, but 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 with the 1.5D array transducer as a representative.
[0006]
[Problems to be solved by the invention]
By the way, there is a demand for a method of obtaining a good measurement accuracy by executing a continuous wave Doppler mode using a 1.5D array transducer. That is, in the continuous wave Doppler mode, it is necessary to divide a plurality of vibrating elements into a transmitting element group and a receiving group, but if the 1.5D array vibrator is simply divided right and left in the electronic scanning direction, the 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 stop down and tends to spread, so that the azimuth resolution of the beam deteriorates and the sensitivity decreases.
[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 an electronic scanning direction in a 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 directed to an ultrasonic diagnostic apparatus having a continuous wave Doppler mode, in which an electronic scanning direction and a plurality of vibrating elements aligned in an elevation direction orthogonal to the electronic scanning direction are used. An array vibrator, and a transmission / reception control unit for controlling the operation of the plurality of vibrating elements, and in the continuous wave Doppler mode, at least one transmission vibration aligned on the array vibrator in the electronic scanning direction. The element group and at least one receiving vibration element group aligned in the electronic scanning direction are set at different positions in the elevation direction.
[0009]
With this configuration, in the 1.5D array vibrator and the 1.75D array vibrator, the transmission vibration element group and the reception vibration element group are arranged at different positions in the elevation direction. In setting the aperture, the transmission aperture and the reception aperture can be sufficiently secured without interfering with each other. Further, the azimuth resolution of the ultrasonic beam can be improved.
[0010]
Further, each of the transmission vibration element groups is a transmission vibration element row constituted by all of the 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. It is preferable that the receiving vibrating element row is constituted by all of the plurality of vibrating elements.
[0011]
With this configuration, in the 1.5D array transducer and the 1.75D array transducer, 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 transducer in the electronic scanning direction is set. It becomes possible to widen the transmission aperture and the reception aperture to the full. The term “all of the plurality of vibrating elements arranged in the electronic scanning direction” is sufficient as long as it is substantially all for transmission / reception control, and may include a dummy element or the like.
[0012]
In addition, it is preferable that the array vibrator includes a plurality of ground electrodes divided for each of the transmission vibration element rows and each of the reception vibration element rows. With this configuration, crosstalk between signals can be suppressed.
[0013]
Further, it is preferable that the transmitting vibrating element row and the receiving vibrating element row are alternately set in the elevation direction.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described 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 an ultrasonic wave and receives an echo, and is used, for example, in contact with a body surface of a subject. An array transducer 42 including a plurality of transducers 43 arranged in the electronic scanning direction and the elevation direction is provided in the probe 41. 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]
The array vibrator 42 has, for example, 128 vibrating elements arranged in a row in the electronic scanning direction to form a vibrating element row. For example, three vibrating element rows are arranged in the elevation direction. Of course, the number of vibrating elements other than 128 or the number of three or more rows 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 relation is performed according to the switching between the continuous wave Doppler mode and the B mode. Also, in the aperture control in each mode, the connection relation may be switched.
[0018]
FIG. 2 shows a connection relationship in the case of the continuous wave Doppler mode. The 1.5D array vibrator 43 is shown as viewed from the drive electrode side of each vibrating element 43. As shown in the figure, each of the vibrating elements 43 constituting the central vibrating element row is connected to a transmission circuit 48. Further, the respective vibrating elements 43 constituting the respective vibrating element rows on both sides of the center row are connected to the same receiving circuit 50 even if the vibrating element rows are different.
[0019]
That is, the vibrating element row in the center row is set as the transmitting vibrating element row 72 in which all the vibrating elements arranged in the electronic scanning direction, for example, 128 vibrating elements in the above example are used for transmission. Further, the respective vibrating element rows on both sides of the center row are set as receiving vibrating element rows 74 and 76 in which all the vibrating 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 and 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, and forms an ultrasonic beam for continuous wave Doppler measurement by transmitting and receiving ultrasonic waves and outputs a reception signal under the control of a transmission / reception control circuit 54 described later. Circuit. More specifically, the transmission circuit 48 is a circuit that supplies a transmission signal delayed for each vibration element 43 of the transmission vibration element row 72, and has a function as a so-called transmission beamformer. The receiving circuit 50 performs a process of amplifying the echo signals from the respective vibrating elements 43 of the receiving vibrating element arrays 74 and 76 by a preamplifier and adjusting a phase difference between signals between channels using a reference signal in a quadrature detection circuit. And a circuit for outputting a reception 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 includes an A / D converter, an FFT calculator, and the like, and is a circuit that analyzes a frequency spectrum of Doppler information included in a received signal of an 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 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 a switch, a keyboard, a trackball, and the like, which are connected to the control unit 52 to be described later, and through 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 controls each component. For example, the transmission / reception control circuit 54 has a function of controlling the transmission / reception unit 46 based on a reference clock. In addition, the connection between each vibrating element and the transmitting / receiving unit 46 by the switching matrix 44 according to the change of the function between the continuous wave Doppler mode and the B mode, for example, by selection from the input unit 66 or automatic selection. Controls the switching of relationships.
[0025]
As described above, in the continuous wave Doppler mode, the 1.5D array vibrator 42 has the center vibrating element row set as the transmitting vibrating element row 72, and is arranged in the electronic scanning direction as long as the number of transmitting circuits permits. All of the vibrating elements are used for transmission. In other words, when the number of transmitting circuits is larger than the number of vibrating elements forming the transmitting vibrating element row, all the vibrating elements are used for transmission, and when the number is small, as many vibrating elements as the number of transmitting circuits allow for transmitting. Used. Further, the respective vibrating element rows on both sides of the central row are set as receiving vibrating element rows 74 and 76, and all the vibrating elements arranged in the electronic scanning direction are used for reception as long as the number of receiving circuits permits. That is, when the number of receiving circuits is larger than the number of vibrating elements constituting the receiving vibrating element row, all the vibrating elements are used for reception, and when the number is small, as many vibrating elements as the number of receiving circuits allow are used for receiving. Used. Therefore, the transmitting vibrating element row and the receiving vibrating element row are set for each vibrating element row, and the transmission aperture is widened as long as the number of transmitting circuits is allowed in the electronic scanning direction of the 1.5D array vibrator. The reception aperture can be widened, and high-sensitivity Doppler information with good azimuth resolution of the ultrasonic beam can be obtained.
[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, the respective vibration elements 43 are 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 vibrating element constituting the central row vibrating element row is connected to the transmitting circuit and the receiving circuit corresponding to the central row, and each vibrating element constituting each vibrating element row on both sides of the central row corresponds to the central row corresponding. Is connected to another transmitting circuit and receiving circuit.
[0027]
Then, the transmission / reception unit 46 forms an ultrasonic beam for a tomographic image by transmitting and receiving the ultrasonic wave, and outputs a reception signal. At this time, the transmission and reception control by the transmission circuit and the reception circuit corresponding to the central row and the transmission and reception control by the transmission circuit and the reception circuit corresponding to the both rows of the central row 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. Is formed. The formed B-mode tomographic image is output to the display 64.
[0028]
FIG. 3 is a diagram illustrating an arrangement of the ground electrode 78 of the 1.5D array vibrator 42 according to the embodiment. The 1.5D array transducer 42 is shown as viewed from the ground electrode side. As shown in the figure, each ground electrode 78 is divided for each vibrating element row, ground electrodes corresponding to the transmitting vibrating element row in the center row are connected to GND1, and each receiving vibrating element row in both side rows of the center row. Are connected to GND2 different from GND1. With this configuration, it is possible to suppress crosstalk between signals in the continuous wave Doppler mode.
[0029]
FIG. 4 is a diagram showing a 1.5D array vibrator 42 according to another embodiment. The 1.5D array vibrator 42 is shown as viewed from the drive electrode side of each vibrating element 43, as in FIG. In the 1.5D array vibrator 42 of this embodiment, each vibrating element row on both sides of the center row is a receiving vibrating element row 74 that uses all the vibrating 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 that in FIG. That is, among the vibrating elements arranged in the electronic scanning direction, the vibrating element rows 73 in the central row use the respective vibrating elements in the central area 80 for transmission, and the other vibrating elements on both sides of the central area 80 along the electronic scanning direction. Are not used for transmission or reception as invalid elements. That is, the vibration elements arranged in the central area 80 are 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, they interfere with each other when setting the transmission aperture and the reception aperture in the electronic scanning direction. Without this, the transmission aperture and the reception aperture can be sufficiently secured in that sense. Further, the azimuth resolution of the ultrasonic beam can be improved.
[0031]
In addition, the element described as an 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 when setting the transmission aperture and the reception aperture in the electronic scanning direction. Can be secured sufficiently.
[0032]
The width of the central region 80 occupied by the transmission vibration element group 81 can be set within a range in which 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 vibrating elements arranged in the electronic scanning direction can be separately set for transmission and reception. Further, the area occupied by the transmission vibration element group 81 is not limited to the central area, and may be an area deviated to either the left or right.
[0033]
FIG. 5 is a diagram illustrating a setting relationship of each vibration element when a 1.75D array vibrator 82 is used in another embodiment. The 1.75D array vibrator 82 has an example in which five vibrating element rows are provided in the elevation direction, and the drawing is viewed from the drive electrode side of each vibrating element. As shown in the figure, each vibrating element row is alternately connected to the transmitting circuit 48 and the receiving circuit 50 every other row. 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 and reception. All of the vibrating elements 43 constituting the vibrating element row are used for reception. Therefore, the size of the transmission aperture and the reception aperture can be made wide over the entire length of the 1.75D array transducer 82 in the electronic scanning direction.
[0034]
If the number of transmitting circuits is smaller than the number of vibrating elements forming the transmitting vibrating element row, as many vibrating elements as the number of transmitting circuits allows are used for transmission, and the number of receiving circuits corresponds to the number of receiving vibrating element rows. When the number is smaller than the number of vibrating elements to be configured, as many vibrating elements as the number of receiving circuits allow are used for reception. Further, as long as the grating lobe does not adversely affect, a plurality of vibrating elements arranged in the electronic scanning direction can be separately set for transmission and reception.
[0035]
In addition to the alternate arrangement setting shown in FIG. 5, for example, it is also possible to perform a setting such as arranging two transmission vibrating element rows in succession and then arranging one or two receiving vibrating element rows. Also, a 1.75D array transducer in which a number of transducer elements other than five are arranged in the elevation direction can be used. Further, the number of rows of the transmission vibration element row and the number of rows of the reception vibration element row can be made equal.
[0036]
The ground electrodes of the 1.75D array vibrator are also divided in the same manner as described with reference to FIG. 3 for each vibrating element row, and each ground electrode corresponding to each transmitting vibrating element row is connected to GND1. In addition, each ground electrode corresponding to each reception vibration element row can be connected to GND2 different from GND1.
[0037]
【The invention's effect】
According to the ultrasonic diagnostic apparatus of the present invention, in the continuous wave Doppler mode, the transmission aperture and the reception aperture in the electronic scanning direction can be sufficiently secured.
[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 illustrating a setting relationship between a transmission vibration element row and a reception vibration element row of a 1.5D array vibrator in a continuous wave Doppler mode in the embodiment.
FIG. 3 is a diagram illustrating an 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 row and a reception vibration element row of a 1.5D array vibrator according to another embodiment.
FIG. 5 is a diagram illustrating a setting relationship between a transmission vibration element row and a reception vibration element row of a 1.75D array vibrator in a continuous wave Doppler mode in the embodiment.
[Explanation of symbols]
Reference Signs List 40 ultrasonic diagnostic apparatus, 41 probe, 42 1.5D array transducer, 43 vibrating element, 44 switching matrix, 48 transmission circuit, 50 reception circuit, 52 control unit, 54 transmission / reception control circuit (transmission / reception control unit), 60 Doppler signal processing circuit, 72, 84, 86 transmission vibration element row, 74, 76, 88, 90, 92 reception vibration element row, 78 ground electrode, 81 transmission vibration element group, 82 1.75D array vibrator.

Claims (4)

In an ultrasonic diagnostic apparatus having a continuous wave Doppler mode,
An array vibrator made up of a plurality of vibrating elements aligned in an electronic scanning direction and an elevation direction orthogonal to the electronic scanning direction, and a transmission / reception control unit that controls operations of the plurality of vibrating elements,
With
In the continuous wave Doppler mode, on the array transducer, 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 are arranged in the elevation direction. Wherein the ultrasonic diagnostic apparatus is set at different positions from each other. The ultrasonic diagnostic apparatus according to claim 1,
Each of the transmission vibration element groups is a transmission vibration element row configured by all of a plurality of vibration elements aligned in the electronic scanning direction, and each reception vibration element group is a plurality of transmission vibration element groups aligned in the electronic scanning direction. An ultrasonic diagnostic apparatus, wherein the ultrasonic diagnostic device is a receiving vibration element row constituted by all of the vibration elements. The ultrasonic diagnostic apparatus according to claim 2,
The ultrasonic diagnostic apparatus, wherein the array transducer includes a plurality of ground electrodes divided for each of the transmission vibration element rows and each of the reception vibration element rows. The ultrasonic diagnostic apparatus according to claim 2,
The ultrasonic diagnostic apparatus according to claim 1, wherein the transmission vibration element row and the reception vibration element row are alternately set in the elevation direction.

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