JP2714102B2 - Ultrasound diagnostic equipment - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial application field) The present invention relates to an ultrasonic diagnostic apparatus which displays an ultrasonic image of a subject to be used for diagnosis.

(Prior Art) Electronic scanning is a typical example of a scanning method (scan) of an ultrasonic wave into a subject.

That is, this scanning uses an array type ultrasonic probe in which a plurality of ultrasonic transducers are arranged side by side. In the case of linear electronic scanning, a plurality of ultrasonic transducers are defined as one unit, and the ultrasonic unit of one unit is used. This is a method of transmitting an ultrasonic beam by exciting the vibrator, for example, by sequentially shifting the pitch by one vibrator and exciting the vibrator while changing the position of one unit of the element in order. Scanning in which the transmission point position of the ultrasonic beam is electronically shifted.

Then, the ultrasonic transducer to be excited is shifted in timing of excitation between the one located at the center of the beam and the one located on the side so that the ultrasonic beam is converged as a beam. The reflected ultrasonic waves are focused (electronically focused) using the phase difference between the generated sound waves of the sound wave vibrator. Then, the reflected ultrasonic waves are received by the same vibrator that was excited and converted into electrical signals, and the echo information from each transmitted / received wave is formed as a tomographic image, and a 30 Hz interlace is performed by a DSC (digital scan converter).
It is converted to a TV (television) signal and displayed on a cathode ray tube or the like.

Also, in the case of sector electronic scanning, the excitation of each transducer is performed such that the transmission direction of the ultrasound beam is sequentially changed into a sector shape for each pulse of the ultrasound beam for one unit of the ultrasound transducer group to be excited. The timing is changed according to a desired direction, and the subsequent processing is basically the same as the above-described linear electronic scanning.

(Problems to be Solved by the Invention) The conventional apparatus has a drawback that the eyes of the operator are easily tired due to flickering of the display screen. As a method for removing this defect, it is conceivable to display an ultrasonic image in a 60 Hz non-interlace by using interlace / non-interlace conversion by motion adaptation of IDTV (Improved TV). However, the interlaced / non-interlaced conversion circuit of IDTV requires four field memories, and has a problem in terms of cost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an inexpensive ultrasonic diagnostic apparatus which reduces flicker on a display screen.

[Means for Solving the Problems] The present invention provides an ultrasonic scanning unit that obtains ultrasonic image information of a subject by ultrasonic scanning, and converts the ultrasonic image information into an interlaced TV signal. In an ultrasonic diagnostic apparatus having a digital scan converter, two field memories each having a storage capacity for one field of the interlaced TV signal from the digital scan converter are connected in series, and Sound image 1
Delay processing means for performing delay processing for frames, intra-field interpolation processing means for performing intra-field interpolation processing on an interlaced TV signal from the digital scan converter, and an interlace signal from the digital scan converter. A motion discriminating means for discriminating the presence or absence of an image motion in a frame from an output signal of the delay processing means, and selecting an output of the delay processing means or an output of the interpolation processing means according to a discrimination result of the motion discriminating means And selecting means for outputting the signal as a non-interlaced TV signal, and display means for displaying an ultrasonic image of the subject based on the output of the selecting means.

(Operation) In the present invention, delay processing for one frame of an ultrasonic image is performed on an interlaced TV signal from a DSC. In normal TV, the odd and even rasters are out of phase, but the DSC output TV signal has an ultrasound scan frame rate of 30 frames / sec or less, which is lower than the TV frame rate (30 frames / sec). Because of the slowness, even when converted to a TV signal, there is no time phase shift between the odd raster and the even raster.
The delay processing is performed by connecting two field memories in series. That is, while four field memories are required in the interlace / non-interlace conversion process by the IDTV motion adaptation, the number of field memories can be reduced to half in the present invention. Since the selection means selects the output of the delay means or the output of the interpolation means to generate a non-interlaced TV signal, the display means can perform flicker-free image display.

(Examples) Hereinafter, the present invention will be described specifically with reference to examples.

 FIG. 1 shows an embodiment of the present invention.

Reference numeral 1 denotes an ultrasonic probe that transmits and receives ultrasonic waves to and from an object, and 2 denotes an ultrasonic scanning unit that obtains ultrasonic image information of the object by ultrasonic scanning. Reference numeral 3 denotes an A / D (analog-to-digital converter) that converts an ultrasonic echo into a digital signal. Reference numeral 4 denotes an ultrasonic image information of a subject at 30 Hz.
It is a DSC (Digital Scan Converter) that converts to an interlaced TV signal. The output "a" of the DSC 4 is taken into the delay processing means 5 and the intra-field interpolation processing means 6.

The delay processing means 5 performs a delay process for one frame of an ultrasonic image with respect to the 30 Hz interlaced TV signal a from the DSC 4, and one-field memories 5a and 5b each having a storage capacity for one field. Are connected in series.

Further, the intra-field interpolation processing means 6 includes the DSC 4
In the field for the 30 Hz interlaced TV signal a, a one-line memory 6a having a storage capacity for one line of the 30 Hz interlaced TV signal, an output C of the memory 6a and the DSC. And an intra-field interpolation operation section 6b for executing an intra-field interpolation operation based on the output a of FIG.

Further, a motion discriminating means 7 is provided after the delay processing means 5.
Is arranged. This motion discriminating means 7 is provided by the DSC
A subtracter 7 for determining the presence or absence of image motion between frames based on the 30 Hz interlaced TV signal a from 4 and the output signal f of the delay processing means 5.
a and a comparator 7b that outputs a selection signal e by comparing the absolute value of the output d of the subtractor 7a with a predetermined reference value Ref.

The output b of the delay processing unit 5 or the output f of the interpolation processing unit is selected at the subsequent stage of the motion determination unit 7 according to the determination result of the motion determination unit 7, and the output b is set to 60 Hz.
A selection means 8 for outputting as a non-interlaced TV signal g is provided. Specifically, when the motion discriminating unit 7 determines that “there is motion in the image”, the selecting unit 8 selects the output f in the intra-field interpolation processing 6, and conversely, the “output f” When it is determined that there is no movement, the output b of the delay processing means 5 is selected by the selection means 8.

Further, at the subsequent stage of the selecting means 8, a D / A (digital / analog) converter 9 for converting the output g of the selecting means 8 into an analog signal and an image display based on the output of the D / A converter 9 are displayed. The CRT display 10 to perform is arranged, and this CRT
A 60 Hz non-interlaced display of an ultrasonic image is performed on the display 10. Here, the CRT display 10 is an example of a display unit in the present invention.

 Next, the operation of the above configuration will be described.

Ultrasonic scanning is performed by the ultrasonic scanning unit 2, and thereby, ultrasonic image information of the subject is collected. This ultrasonic image information is converted into a digital signal by the A / D converter 3 and then taken into the DSC 4. Scan conversion is performed in the DSC 4, and a 30 Hz interlaced TV signal a is output by this conversion processing. If it is a conventional device,
The interlaced display is performed by the 30 Hz interlaced TV signal a.
Non-interlaced display is performed by converting the signal a into a 60 Hz non-interlaced TV signal g.

 This conversion process is performed as follows.

The output a of the DSC 4 is taken into the delay processing means 5,
By sequentially passing through the one-field memories 5a and 5b, a delay process for one frame of the ultrasonic image is performed.

On the other hand, the output a of the DSC 4 is also taken into the intra-field interpolation processing means 6, which performs intra-field interpolation processing. That is, by this interpolation processing, information between the scanning lines of the 30 Hz interlaced signal is generated.

In the motion determining means 7, a subtractor 7a performs a subtraction process on the output b of the delay processing means 5 and the output a of the DSC 4, and a comparator 7b compares the subtraction result d with the reference value Ref. Done. In this comparison, if d <Ref, it is determined that "there is no motion in the image", and the selector 8 selects the output b of the delay processing means 5. Conversely, if d> Ref, it is determined that “there is motion in the image”, and the output f of the intra-field interpolation processing means 6 is selected by the selection means 8. In this way, a 60 Hz non-interlaced TV signal g is generated, which is transmitted via the D / A converter 9 to the CRT display 10.
Will be displayed.

FIG. 2 shows the relationship between the vertical synchronizing signal VD and the raster in interlacing, and FIG. 3 shows a non-interlaced display raster. In FIG. 3, a broken line 12 corresponds to the Even raster.

That is, in this embodiment, if there is no motion in the image, the output b of the delay processing means 5 is selected by the selection means 8, so that the Odd raster one field before in the 30 Hz interlaced TV signal is indicated by a solid line 11. In the case where the image is used as it is and the image has motion, on the contrary, the output f of the intra-field interpolation processing means 6 is selected by the selection means 8 to interpolate the Even raster in the 30 Hz interlaced TV signal. The processing result (the output of the intra-field interpolation processing means 6) is used as a raster indicated by a solid line 11.

Thus, in this embodiment, the 60 Hz non-interlaced
Since the TV signal is generated and the non-interlaced display of the ultrasonic image is performed based on the TV signal, it is possible to display a good image without flickering compared to the conventional 30 Hz interlaced display. . In addition, in ultrasound images, ultrasound scanning is generally longer than the vertical synchronization signal VD of the display system.
By performing the non-interlace conversion, the noise in the image is extremely small, and the motion detection system is much simpler than in the case of the IDTV. Since only two field memories are required, the cost can be reduced.

Further, the interlace / non-interlace conversion system in this embodiment can be easily attached to an existing device, and even if this conversion system is installed, the basic system of the existing device is not changed. , Ultrasound image VTR
It goes without saying that recording is possible.

Although the 30 Hz interlace display system is omitted in FIG. 1, a D / A converter and a CRT display dedicated to interlace display may be arranged at the subsequent stage of DSC 4, and in FIG. D / A converter 9 and CRT display 10
It can be used for both Hz interlaced display and 60Hz non-interlaced display.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made.

In the above embodiment, the electronic scanning of the ultrasonic wave is described. However, the present invention can be applied to the case of performing the mechanical scanning.

[Effects of the Invention] As described above in detail, according to the present invention, an ultrasonic diagnostic apparatus capable of reducing flicker on a display screen can be provided at low cost.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is an explanatory diagram of a relationship between a vertical synchronizing signal and a raster in interlacing, and FIG. 3 is an explanatory diagram of a non-interlaced display raster. 2 ... Ultrasonic scanning unit 4 ... DSC (Digital Scan Converter) 5 ... Delay processing means 5a, 5b ... 1 field memory 6 ... Intra-field interpolation processing means 7 ... Motion discriminating means 8 ... selection means, 10 ... CRT display (display means).

Claims (1)

(57) [Claims] 1. An ultrasonic scanning unit for obtaining ultrasonic image information of a subject by ultrasonic scanning, and a digital scan converter for converting the ultrasonic image information into an interlaced TV signal, In an ultrasonic diagnostic apparatus for displaying an acoustic image for diagnosis, the ultrasonic diagnostic apparatus comprises two serially connected field memories having a storage capacity for one field of an interlaced TV signal from the digital scan converter. Delay processing means for performing delay processing for one frame of an ultrasonic image on a TV signal; intra-field interpolation processing means for performing intra-field interpolation processing on an interlaced TV signal from the digital scan converter; An image in a frame is obtained from the interlace signal from the scan converter and the output signal of the delay processing means. Motion discrimination means for discriminating the presence or absence of motion, and selects the output of the output or the interpolation processing means of the delay processing unit according to the determination result of the motion judgment means,
An ultrasonic diagnostic apparatus comprising: selecting means for outputting the signal as a non-interlaced TV signal; and display means for displaying an ultrasonic image of the subject based on the output of the selecting means.