JP2006247061A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide ultrasonic diagnostic apparatus capable of displaying a suitable ultrasonic tomographic image by changing the center frequency or pulse length of ultrasonic waves to be transmitted according to the visual field depth. <P>SOLUTION: This ultrasonic diagnostic apparatus is provided with an operation panel 1 capable of inputting setup matters, a system controller 2 controlling respective parts based on the command from the operation panel, a transmission circuit 3 generating high voltage pulse for transmitting ultrasonic waves, an ultrasonic probe 4 transmitting/receiving the ultrasonic waves, a receiving circuit 5 processing signals from the ultrasonic probe, an image processor 6 forming image data from the processed signals, and a monitor 7 displaying the formed image data as an image. The system controller sets the center frequency or the pulse length of the ultrasonic waves transmitted from the ultrasonic probe according to the visual field depth. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ultrasound diagnostic apparatus that transmits and receives ultrasound and obtains a tomographic image of a subject.

  In general, an ultrasonic wave has a characteristic that a high frequency component is attenuated more greatly than a low frequency component in a living body. Therefore, low-frequency ultrasonic waves are used for diagnosis of deep positions in the living body. In addition, high-frequency ultrasonic waves can be used for diagnosing shallow positions in a living body because high-resolution images can be obtained.

  Thus, in ultrasonic diagnosis, it is desirable to measure by changing the center frequency of the ultrasonic wave according to the position of the part to be detected. For example, Patent Document 1 describes an ultrasound diagnostic apparatus that changes the center frequency of ultrasound used for ultrasound diagnosis in accordance with the focus position of a detection site.

  FIG. 3 is a block diagram showing a configuration example of the ultrasonic diagnostic apparatus as described above. Data set from the operation panel 101 in which various diagnostic conditions are set is sent to the system controller 102. The system controller 102 controls the entire system, determines the corresponding ultrasonic frequency based on the focus position, color display area, or Doppler signal detection position set by the operation panel 101, and transmits the determined frequency data to the transmission circuit 103. Send to.

The transmission circuit 103 generates a trigger signal based on the frequency data and sends it to the high output circuit 104. The high output circuit 104 converts the trigger signal into a high voltage signal and applies it to the ultrasonic probe 105. The ultrasonic probe 105 transmits and receives an ultrasonic wave based on a high voltage signal, converts the received ultrasonic wave into an electric signal, and sends the electric signal to the receiving circuit 106. The receiving circuit 106 performs processing such as amplification and detection on the received signal and sends the processed signal to the image processing device 107. The image processing device 107 converts the received signal into image data, sends the image data to the TV monitor 108, and displays it as an image.
Japanese Patent Laid-Open No. 6-54850

  However, in the above ultrasonic diagnostic apparatus, the center frequency of the ultrasound changes according to the focus position, but even if the depth of field is changed to display the target site of diagnosis, the center frequency or pulse of the ultrasound pulse is changed. The length is not changed. Therefore, when the display image is enlarged and displayed without changing the visibility limit or spatial resolution, the area displayed per pixel increases, the image deteriorates, and it is difficult to obtain biological information around the target site for diagnosis. Occurs.

  The present invention is for solving the above-described problem, and an ultrasonic wave capable of displaying a suitable ultrasonic tomographic image by changing the center frequency or pulse length of the ultrasonic wave to be transmitted according to the depth of field. An object is to provide a diagnostic apparatus.

  In order to achieve the above object, an ultrasonic diagnostic apparatus of the present invention includes an ultrasonic transmission / reception unit that transmits / receives ultrasonic waves, an image processing unit that forms image data based on the ultrasonic transmission / reception unit, and an image data display image. Display means for displaying as, a visual field depth setting means for setting the visual field depth of the display image to be displayed on the display means, and an ultrasonic transmission control for setting the center frequency and pulse length of the ultrasonic wave transmitted from the ultrasonic transmission / reception means The ultrasonic transmission control means performs at least one setting of the center frequency or pulse length of the ultrasonic wave transmitted from the ultrasonic transmission / reception means in accordance with the visual field depth set by the visual field depth setting means. Features. With this configuration, it is possible to display an appropriate display image corresponding to the depth of field.

  Further, the ultrasonic transmission control means may be configured to set the center frequency of the ultrasonic wave transmitted from the ultrasonic transmission / reception means to be lower as the depth of field is set deeper. With this configuration, only by setting the depth of field, the center frequency of the corresponding ultrasonic wave is set, and an appropriate display image can be displayed.

  In addition, the ultrasonic transmission control means can be configured to set a longer pulse length of the ultrasonic wave transmitted from the ultrasonic transmission / reception means as the depth of field is set deeper. With this configuration, only by setting the depth of field, the corresponding ultrasonic pulse length is set, and an appropriate display image can be displayed.

  According to the present invention, it is possible to provide an ultrasonic diagnostic apparatus capable of displaying a suitable ultrasonic tomographic image by changing the center frequency or pulse length of ultrasonic waves to be transmitted according to the depth of field.

  Hereinafter, preferred examples of the ultrasonic diagnostic apparatus of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram showing a configuration example of the ultrasonic diagnostic apparatus according to the first embodiment of the present invention. The operation panel 1 (field-of-view depth setting means) is for the operator to input various diagnostic conditions such as selection of a diagnostic mode and field-of-view depth. The setting conditions input from the operation panel 1 are input to the system controller 2 (ultrasound transmission control means). The depth of field is the length from the ultrasonic probe 4 to the position of the subject corresponding to the lowest part of the ultrasonic image displayed on the monitor 7.

  The system controller 2 controls the entire system, and determines the center frequency of the ultrasonic wave transmitted from the ultrasonic probe 4 (ultrasonic transmission / reception means) based on the depth of field input from the operation panel 1 in particular. A signal related to the determined center frequency of the ultrasonic wave is input to the transmission circuit 3. The transmission circuit 3 generates a high voltage pulse signal based on the center frequency of the ultrasonic wave determined by the system controller 2 and applies it to the ultrasonic probe 4.

  The ultrasonic probe 4 transmits an ultrasonic wave based on the high voltage pulse signal applied from the transmission circuit 3, receives the ultrasonic wave reflected by the subject, and converts it into an electric signal. In addition, since the ultrasonic probe 4 used in the present embodiment changes the frequency of the ultrasonic wave according to the depth of field, one having a wide frequency band or one having a plurality of ultrasonic elements is used, for example, from 5 MHz. Ultrasonic waves up to 9 MHz can be transmitted and received.

  The reception circuit 5 amplifies the reception signal received by the ultrasonic probe 4, receives data such as the ultrasonic center frequency from the system controller 2, and performs signal processing such as detection processing of the reception signal. The reception circuit 5 transmits the reception signal subjected to the detection process to the image processing device 6 (image processing means). The image processing device 6 receives the reception signal subjected to the detection processing, converts the received signal into image data (tomographic image data) based on the received signal, and further converts the tomographic image data based on information such as the visual field depth from the system controller 2. The data is converted into data (display image data) that can be displayed on the monitor 7. The converted display image data is transmitted to the monitor 7 (display means), and the monitor 7 displays the display image data as a display image as an image of a certain size.

  FIG. 2 is a diagram showing a relationship between a tomographic image formed by tomographic image data received by the ultrasonic diagnostic apparatus and a tomographic image region (display region) displayed as a display image on the monitor 7. In FIG. 2A, the tomographic image 21a is indicated by a solid line, and the display area 22a is indicated by a broken line. The upper part of the figure is the ultrasonic probe side. An arc at a deep position with respect to the ultrasonic probe in the tomographic image 21a indicates a visibility limit that is the deepest position (distance from the ultrasonic probe) at which an ultrasonic reflected wave can be received.

  FIG. 2B shows a case where a tomographic image 21b having a shallower depth of field than the tomographic image 21a is displayed. The tomographic image 21a and the display area 22a in FIG. The tomographic image 21b originally corresponds to the size of 22b as a display image, but is displayed as the size of 22a. In the conventional ultrasonic diagnostic apparatus, even if the depth of field is set to be shallow, the spatial resolution does not change because the center frequency of the ultrasonic wave is not changed. That is, even if tomographic image data having a shallow depth of field is displayed in accordance with the size of the monitor 7, the spatial resolution is not improved.

  On the other hand, when the depth of field is set to be shallow, the ultrasound diagnostic apparatus according to the present embodiment increases the frequency of the ultrasound transmitted from the ultrasound probe according to the depth of field. When the frequency of the ultrasonic wave is increased, the spatial resolution of the tomographic image is increased, so that a display image with high definition can be obtained.

  Next, the operation of the ultrasonic diagnostic apparatus having the above configuration will be described. Setting items of the depth of field are input from the operation panel 1. The input setting items are input to the system controller 2. In the system controller 2, a suitable ultrasonic center frequency is determined according to the input setting items. A signal related to the determined ultrasonic center frequency is sent to the ultrasonic probe 4 via the transmission circuit 3, and data such as the depth of field and the ultrasonic center frequency is sent to the receiving circuit 5 and the image processing device 6. It is done. Based on the transmitted signal, the ultrasonic probe 4 transmits an ultrasonic wave.

  The ultrasonic wave reflected by the subject is received by the ultrasonic probe 4 and becomes an electric signal, and the receiving circuit 5 performs signal processing such as amplification and detection. The electric signal subjected to the signal processing is sent to the image processing device 6 to generate tomographic image data, and display image data is formed from the tomographic image data and the visual field depth data from the system controller 2. The created display image data is sent to the monitor 7 and displayed as a display image.

  The ultrasonic diagnostic apparatus in the present embodiment as described above can set a center frequency of ultrasonic waves according to the depth of field and display a suitable display image.

(Second Embodiment)
The configuration of the ultrasonic diagnostic apparatus according to the second embodiment of the present invention is the same as that of FIG. 1 except that the ultrasonic forming signal generated by the system controller 2 is different from that of the first embodiment. About the same structure, the same code | symbol is attached | subjected and description is abbreviate | omitted. The feature of this embodiment is that the pulse length of the ultrasonic wave transmitted from the ultrasonic probe 4 is changed according to the depth of field. Hereinafter, the ultrasonic diagnostic apparatus of the present embodiment will be described with reference to FIG.

  The resolution in the traveling direction of the ultrasonic wave depends on the pulse length of the ultrasonic wave. The resolution is improved if the pulse length is short. However, the shorter the pulse length, the smaller the ultrasonic transmission output and the lower the visibility limit. On the contrary, if the pulse length is long, the resolution becomes low, but the transmission output becomes large and the visibility limit becomes deep, so that it is possible to measure the subject at a position away from the ultrasonic probe 4. Therefore, it is necessary to determine the pulse length according to the depth of field.

  A system controller of the ultrasonic diagnostic apparatus according to the present embodiment will be described. When receiving a signal for enlarging the display image from the operation panel 1 and reducing the depth of field, the system controller 2 generates a signal for shortening the pulse length of the ultrasonic pulse. This corresponds to the case where the center frequency of the ultrasonic wave in the first embodiment is increased, and in contrast to the explanation of FIG. 2B, “higher ultrasonic frequency” is set to “higher ultrasonic pulse length. It can be explained in the same way by replacing with “short”. As a result, the spatial resolution can be increased, and deterioration of the enlarged display image can be prevented.

  As described above, the ultrasonic diagnostic apparatus according to the present embodiment can display a suitable ultrasonic image by changing the ultrasonic pulse length according to the depth of field.

  Further, the ultrasonic diagnostic apparatus of the present invention may be configured to switch which setting of the ultrasonic center frequency and pulse length is changed with respect to the change of the visual field depth. Furthermore, it is also possible to adopt a configuration in which both the center frequency and pulse length of the ultrasonic wave are changed.

  In addition, the ultrasonic diagnostic apparatus of the present invention, when the depth of field is set, for example, correspondence between the depth of field and the center frequency so that the visible limit of ultrasound becomes a length corresponding to the set depth of field. It is also possible to create data and set at least one of the center frequency or pulse length of the ultrasonic wave. With this configuration, a high-quality display image can be displayed.

  Note that this embodiment is an example of the present invention and is not limited to the above-described embodiment.

  The ultrasonic diagnostic apparatus of the present invention has an advantage that an appropriate tomographic image can be obtained by changing the center frequency or pulse length of ultrasonic waves to be transmitted according to the depth of field. Useful in the field of diagnosis.

1 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to a first embodiment of the present invention (A) is a figure which shows the relationship between a tomographic image and a display image, (b) is the figure at the time of the enlarged display Block diagram showing the configuration of a conventional ultrasonic diagnostic apparatus

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Operation panel 2 System controller 3 Transmission circuit 4 Ultrasonic probe 5 Reception circuit 6 Image processing apparatus 7 Monitor 21a, 21b Tomographic image 22a, 22b Display area

Claims (3)

Ultrasonic transmission / reception means for transmitting / receiving ultrasonic waves;
Image processing means for forming image data based on the ultrasonic transmission / reception means;
Display means for displaying the image data as a display image;
A depth of field setting means for setting a depth of field of the display image to be displayed on the display means;
Ultrasonic transmission control means for setting the center frequency and pulse length of ultrasonic waves transmitted from the ultrasonic transmission / reception means,
The ultrasonic transmission control means sets at least one of a center frequency or a pulse length of an ultrasonic wave transmitted from the ultrasonic transmission / reception means in accordance with a visual field depth set by the visual field depth setting means. Ultrasound diagnostic device.   The ultrasonic diagnostic apparatus according to claim 1, wherein the ultrasonic transmission control unit sets a lower center frequency of ultrasonic waves transmitted from the ultrasonic transmission / reception unit as the depth of field is set deeper.   The ultrasonic diagnostic apparatus according to claim 1, wherein the ultrasonic transmission control unit sets a longer pulse length of the ultrasonic wave transmitted from the ultrasonic transmission / reception unit as the depth of field is set deeper.

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