JP3555699B2 - Ultrasonic device - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to an ultrasonic device, and more particularly to an ultrasonic device capable of correcting an uneven sound velocity of a subject and displaying an image.
[0002]
[Prior art]
FIG. 2 shows an example of a conventional ultrasonic device. An ultrasonic transducer array 1 is selectively driven by a plurality of transducers by a transmission circuit 2 to transmit ultrasonic waves. The radiated ultrasonic wave is reflected from the subject 3 and received by the ultrasonic transducer array 1, and the time difference to the focal point of each transducer is delayed and phased by the wave receiving and phasing unit 4, and is transmitted to the signal processing unit 5. The image is processed for display on the monitor 6. At this time, the delay data of each element for focusing the transmission wave and the delay focus data of the reception phasing unit 4 are created assuming that the sound speed C of the subject is uniform, and the focus point between the elements is obtained. , The delay time t is given by t−d / c. However, the actual subject is not uniform and has a velocity distribution. Therefore, a desired beam is not formed and the resolution is deteriorated. Various methods have been proposed for this velocity distribution correction, such as a method of obtaining and correcting a phase difference between elements, and a method of obtaining and correcting a phase difference by cross-correlating signals of adjacent elements.
[0003]
[Problems to be solved by the invention]
Many of the various correction methods are effective on simulation and under specific conditions. For this reason, an accurate image is not always displayed, and there is a problem that diagnosis is difficult for actual medical use. Further, the conventional configuration is insufficient to be used as a judgment material for developing and using a more accurate correction algorithm.
Therefore, an object of the present invention is to provide an ultrasonic apparatus suitable for assisting a determination as to whether a correct correction has been made or an image has been improved when applied to a subject.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, the ultrasonic apparatus according to the present invention employs, for the same part, “imaging without correction (tomographic image based on beam forming data created at virtual uniform sound velocity)” and “sound velocity correction unit (FIG. 1) (7)) (the tomographic image based on the beam forming data corrected for the non-uniform sound velocity) "displayed simultaneously and in a comparable manner. When a plurality of ultrasonic beams are formed at the same time, the total number of display rasters is divided, and one of the beams to be formed at the same time is determined based on the beam forming data created by the virtual setting uniform sound velocity of the subject. It is characterized in that other beams to be formed at the same time are formed based on the beam forming data in which the sound velocity non-uniformity of the subject is corrected, and respective tomographic images are obtained. Further, while obtaining a tomographic image based on the beam forming data created by the virtual setting uniform sound velocity of the subject, the correction data of the non-uniform sound speed of the subject is obtained, the focus data is rewritten, and the corrected tomographic image is obtained. There is a feature in displaying.
[0005]
[Action]
In the present invention, it is possible to provide a user with information by simultaneously (or selecting) and displaying an image in which the same part is not corrected at the same time and a corrected image that can be compared, as described above. You can ask a doctor or a laboratory technician for a more accurate diagnosis. Alternatively, a practical and efficient correction algorithm can be developed using the software development support.
Further, in an apparatus capable of forming multiple beams, the frame rate can be improved by dividing the total number of display rasters and forming beamforming data with uniform sound speed and data obtained by correcting nonuniform sound speed from each. .
Further, while obtaining the tomographic image from the beam forming data at the uniform sound velocity, the control data is rewritten to obtain the correction data for the non-uniform sound velocity and the corrected tomographic image is displayed, so that the user does not feel uncomfortable. Real-time display can be performed.
[0006]
【Example】
Hereinafter, an embodiment of the present invention will be described. FIG. 1 shows the basic configuration. An ultrasonic transducer array 1 is selectively driven by a plurality of transducers by a transmission circuit 2 to transmit ultrasonic waves. The radiated ultrasonic wave is reflected from the subject 3 and received by the ultrasonic transducer array 1, and the time difference to the focal point of each transducer is delayed and phased by the wave receiving and phasing unit 4, and is transmitted to the signal processing unit 5. The image is processed for display on the monitor 6. In the prior art, the sound velocity of the subject is assumed to be uniform. However, since the sound velocity actually shows a non-uniform distribution, the velocity distribution is corrected by obtaining the phase difference between the elements or by correcting the signals of adjacent elements. Various proposals have been made such as a method of obtaining and correcting a phase difference by taking a correlation. In the present embodiment, the sound velocity correction unit 7 using one of these correction methods obtains a corrected sound velocity, obtains focus data, and operates the transmission unit 2 and the reception phasing unit 4 based on the data. Form a correction beam.
At this time, as shown in FIG. 3, the monitor 6 is divided into two parts, and an image A based on the data before correction and an image B based on the data after correction are simultaneously displayed. In the image A before correction, the target image (spherical portion) is unclear, whereas in the image B after correction, the spherical portion is clearer. However, as described above, the corrected image is not always the correct image. Therefore, in the present embodiment, it is determined how the user changes the image by viewing the images A and B. It is configured so that the user can easily understand and further determine whether to proceed with the process or return to the original image and make a selection.
[0007]
Next, FIG. 4 shows an example of an application method in the case of a device capable of multiple beams. FIG. 4 is an example of the reception phasing multiple beam. FIG. 4 shows an example in which two receiving phasing units 4 are prepared and a receiving double beam is formed at the same time. The reception phasing unit 4-A that forms the A beam is delayed by the control data unit 7-A. The reception phasing unit 4-B that forms the B beam is delayed by the control data unit 7-B. Here, the wave receiving phasing unit 4-A forms a beam using the control data before correction. The reception phasing unit 4-B is the same as that in which the data obtained by the correction processing unit 7-C is written in the control data unit 7-B and input to the reception phasing unit 4-A based on the data. The received signal is simultaneously processed with the correction data. By this processing, as shown in FIG. 3, images before and after the correction of the same part can be simultaneously displayed.
[0008]
FIG. 5 is another example of formation of a receiving double beam. In the above embodiment, the received signal may be an analog signal or a digital signal. FIG. 5 shows an example of the wave receiving phasing unit 4 capable of handling received data in a time series by sampling, and is used alternately with the A beam and the B beam for each sampling. Naturally, the control data 7-A and 7-B are used alternately. After the phasing, the signal processor 5 separates and processes the beam data A and B in parallel. The sequence of sampling data A forming the A beam is delayed by the control data unit 7-A. The sequence of the sampling data B forming the B beam is delayed by the control data unit 7-B. Here, the control data 7-A is control data before correction, and forms a beam before correction. As for the control data 7-B, the data received by the correction processing unit 7-C is written in the control data unit 7-B, and based on the data, the same reception signal as that input to the reception phasing unit 4 is simultaneously corrected. It is to be processed with data. By this processing, as shown in FIG. 3, images before and after the correction of the same part can be simultaneously displayed.
In these examples, when it takes time to generate the correction data by the correction processing unit 7-C, the image is formed and displayed by the reception phasing unit 4, and the control data is generated during that time. By rewriting B and switching when it becomes operable, the display is efficiently performed without giving the user a sense of incongruity.
[0009]
Next, an example of the raster creation order is shown in FIG. When one image is composed of the number of rasters n as shown in FIG. 6A and the multiple beams have the same number of rasters and the frame rate is to be improved, as shown in FIG. The number is halved, the first half rasters 1 to n / 2 are allocated to the image before correction, and the second half rasters (1 + n / 2) to n are allocated to correction data. In this scanning, the number of control memory data is the same because the number of raster lines and the approximate number of beams do not change. On the other hand, the number of data is doubled in order to make the entire screen only the respective images and not change the scanning density.
In this embodiment, only two beams have been described, but it is needless to say that the number is not limited to two. Although only the reception is described, it is necessary to change the frequency and phase to simultaneously image the same part in the transmission, but in a system that can transmit ultrasonic waves in multiple directions, the same It goes without saying that scanning is possible.
[0010]
When the frame rate of the transmitted / received beam is not changed as shown in FIG. 7B, the display is performed by 1/2 of the total number n of rasters, and the scanning area is set to n / 4 to 3n / 4. . Also, as shown in FIG. 7A, the uncorrected A beam scans from raster 1 to n / 2 in order. On the other hand, the B beam to be corrected starts simultaneously from the raster n / 4 and transmits and receives in order, and the raster of the B raster starts from n / 4 of the raster of the A beam, goes to n / 2, and then returns to 1. By proceeding to n / 4, it is possible to scan the same area as a result by scanning that avoids interference when transmitting waves at the same time, and it is possible to perform almost simultaneous imaging of the same part before and after correction of similar transmitted and received waves It becomes.
[0011]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, when a non-uniform sound velocity correction is actually applied to a subject, it is possible to assist in determining whether correct correction has been made or an image has been improved, and a more accurate image can be provided. In addition, if used for medical treatment, more accurate diagnosis can be made, and if it is used for algorithm development support, it will be useful for efficient development.
[Brief description of the drawings]
FIG. 1 is a basic configuration diagram of an ultrasonic diagnostic apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating a basic configuration example of a conventional ultrasonic diagnostic apparatus.
FIG. 3 is a diagram illustrating an imaging display method according to an embodiment of the present invention.
FIG. 4 is a diagram showing a memory rewriting configuration according to the first embodiment of the present invention.
FIG. 5 is a diagram showing a memory rewriting configuration according to a second embodiment of the present invention.
FIG. 6 is a diagram illustrating a beam scanning method according to a third embodiment of the present invention.
FIG. 7 is a diagram illustrating a beam scanning method according to a fourth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Ultrasonic transducer array, 2 ... Transmission circuit, 3 ... Subject, 4,4-A, 4-B ... Reception phasing unit, 5 ... Signal processing unit, 6 ... Monitor, 7 ... Sound speed correction unit , 7-A, 7-B... Control data section, 7-C... Correction processing section.

Claims (2)

An ultrasonic apparatus that transmits and receives ultrasonic waves by an arrayed ultrasonic transducer and obtains a tomographic image using a sound velocity set for a subject, and an apparatus that simultaneously forms and captures a plurality of ultrasonic beams,
Means for dividing the number of rasters of the ultrasonic scanning line, and means for forming one of the beams formed simultaneously with a tomographic image based on beam forming data created at a uniform sound velocity virtually set for the subject. Means for forming a tomographic image based on beam forming data obtained by correcting other beams to be formed simultaneously based on the phase difference between the elements or the cross-correlation of signals of adjacent elements, with respect to the non-uniform velocity of sound of the subject; And a display means for simultaneously displaying the tomographic images obtained by the method. The ultrasonic device according to claim 1,
Each means for obtaining and displaying a tomographic image based on the beam forming data created at the uniform sound velocity is configured to obtain the correction data for the non-uniform sound velocity, rewrite the focus data, and display the corrected tomographic image. An ultrasonic device characterized by the above-mentioned.

Images