JPS6140074B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a method of transmitting sound wave pulses into a subject and receiving the echoes thereof, and sequentially writing sound wave echo information into an image memory via an input line buffer memory. The present invention relates to an ultrasonic imaging device that forms image information in the image memory and reads out the image information stored in the image memory to display an echo image.

For example, in an ultrasound imaging device such as a medical ultrasound diagnostic device, the obtained ultrasound image, that is, the echo image, is transmitted to a general television (hereinafter referred to as "TV") regardless of the scanning method on the imaging side (detection side). In order to display images on a display device (abbreviated as ``video''), the video signal obtained by scanning the sound wave beam must be converted into a video signal based on the TV standard scanning method, and then provided to the TV display device along with a synchronization signal of the same method. As an example of a device that performs scanning method conversion in this manner, there is a scan conversion device called a digital scan converter. The digital scan converter converts the input video signal into an analog-to-digital converter (hereinafter referred to as "A/D converter").
The data is digitized by an input line buffer memory (hereinafter referred to as an "input buffer") and written to an image memory line by line using the original scanning method, and the contents of this image memory are scanned as required. It is common to read and output one line at a time via an output line buffer memory (hereinafter referred to as "output buffer") in synchronization with a synchronizing signal of the system. By using this digital scan converter, the echo image signal can be
Compliant with the TV standard scanning system, echo images can be displayed with excellent display images in terms of brightness and resolution, and dynamic images of echo images can also be recorded using TV recording equipment. This can be done by simply inputting the image signal directly. Moreover,
Many general-purpose display devices, recording devices, parts, etc. for the TV standard scanning method are manufactured and sold, and high-performance products can be easily obtained at low cost. It has the advantage of being able to use general-purpose products. Furthermore, since the digital scan converter digitizes the image signal and stores it in the image memory, image analysis and
It has the advantage that image processing such as partial enlargement can be easily performed.

By the way, the image memory in the above-mentioned digital scan converter etc. is usually called a frame memory and has a storage capacity for one screen. When it is desired to observe or enlarge the vicinity of an end in detail, it is necessary to move the display image position on the display screen in order to display a desired area at a desired position on the display screen. Such movement of the image position on the display screen is equivalent to movement of the write area of input image data on the image memory. However, if you simply move the writing area with the intention of moving the image in this way, the image data in the part of the image memory that falls outside the image area as a result of the image movement will not be updated, and only this part will have the previous image data. Image data remains. Therefore, in this case, on the display screen, the previous image is displayed in the area that should be blank because the input image information is lost because it is out of the image area as a result of the movement.
The display screen becomes unsightly, and there is a risk that reading the image will be hindered. Therefore, it is a good idea to first erase the stored contents of the image memory over the entire image memory, that is, the entire screen, when moving the image, and then write image data in different write areas on the image memory. It will be done. However, the image memory has a large capacity, and it takes a considerable amount of time to erase the entire image. Since writing to the image memory cannot be performed while this image memory is being erased, even when image data is updated in real time and displayed in real time using a so-called real-time scan, for example, when moving the image, In this case, updating of the image must be temporarily interrupted, and it is therefore virtually impossible to continuously move the image while viewing the displayed image.

The present invention has been made against this background, and an object of the present invention is to provide an ultrasound imaging device that can smoothly move the image position of an echo image without actually interrupting image display.

That is, the present invention is characterized by transmitting sound wave pulses into the subject and receiving the echoes, and sequentially writing the sound wave echo information into the image memory via the input line buffer memory to obtain the image. In an ultrasonic imaging device that forms image information in a memory and displays an echo image by reading out the image information stored in the image memory, the input line voltage is set within a period between echo receptions corresponding to each sound wave pulse. After writing erase data for erasing the memory contents of the input line buffer memory into the buffer memory, the write address of the input echo information to the input line buffer memory is set according to image position information set externally. The present invention is modified to include means for writing echo information into a portion of the input line buffer memory and supplying the echo information to the image memory together with erased data for the portion where no echo information has been written.

In the present invention, as described above, the conventional image information can be erased in a short time by writing the erase data in the input buffer memory, which has a significantly smaller capacity than the image memory, and each line of input image information can be erased in a short time. The image is moved very rationally by erasing each line during the rate pulse period during information input, and moving the image by changing the writing address of the input information to the input buffer. It is.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of an embodiment in which the present invention is applied to an ultrasonic diagnostic apparatus employing a digital scan converter.

In FIG. 1, 1 is a transmitting/receiving device that sends and receives sound waves to and from the subject, 2 is an A/D converter that converts the echo signal received by the transmitting/receiving device 1 into a digital signal, and 3 is an A/D converter. An input buffer temporarily stores the echo information (for one line) digitized by the input buffer 2, and 4 is a screen that is written and updated as specified by the echo information transferred from the input buffer 3, and holds and stores the echo image information. 5 is an output buffer for temporarily storing image information read out from the image memory 4 for each line in the output scanning method, that is, in this case, the TV standard scanning method; 6 is an output buffer for storing image information read out sequentially from the output buffer 5; D/A to convert back to analog signal
Converter 7, a mixing device for mixing the image information output from the D/A converter 6 with a synchronization signal for the TV standard scanning method; 8, an echo image display in the TV standard scanning method using the output of the mixing device 7; This is a TV display device. Reference numeral 9 denotes an image memory control device that controls writing and reading of the image memory 4, 10 an output buffer control device that controls writing and reading of the output buffer 5, and 11 a mixing device 7 that generates a synchronization signal for the TV standard scanning system, and the like. This is a signal generator that provides the same basic signal. And 12 is input buffer 3
The input buffer control device is an input buffer control device that performs write/read control of the input buffer, and the details of this input buffer control device will be described later. Reference numeral 13 denotes an image position signal generator that generates an image position signal for image movement operation in response to an external operation, and reference numeral 14 denotes an A/D converter that converts the image position signal given as an analog signal from the image position signal generator 13 into a digital signal. D
The converter 15 is a code converter that converts the output image position signal of the A/D converter 14 into position data corresponding thereto.

The input buffer control device 12 has a built-in address counter 12a, and this address counter 12a is capable of counting from 0 to 2N-1 when the capacity of the input buffer 3 corresponds to N pixels, for example. While the rate pulse for transmitting sound waves is being generated in the device 1, a high-speed clock FC with a cycle of 2N or more is input as a count input within the pulse width of the rate pulse, and this count input is counted from 0 to 2N-1. In addition, while the echo is being received in the transmitting/receiving device 1, the sampling clock SC of the echo signal in the A/D converter 2 is input as a count input, and this count input is converted to a value preset by the output of the code converter 15. It is reset when N counts are counted from this value as the count start value.

That is, in this case, in the input buffer control device 12, the address count 12a assumes that the input buffer 3 is a virtual memory corresponding to 2N pixels having addresses from 0 to 2N-1.
The actual input buffer 3 exists only at addresses N to 2N-1, and the data write address for the input buffer 3 is moved by changing the write start address when inputting image information.

Note that the input buffer control device 12 receives rate pulses for sending out sonic pulses from the transmitting/receiving device 1.
RP is input and used for switching the count input and preset input of the address counter 12a, and a sampling clock SC for echo signal sampling is created in the input buffer control device 12 based on the rate pulse RP. At the same time as being input to the address counter 12a, it is also applied to the A/D converter 2 to synchronize the writing of input echo information.

Further, the output buffer controller device 10 is provided with a synchronization pulse SC from a synchronization signal generator 11 to synchronize the readout of echo image information.

Next, the operation in such a configuration will be explained.

FIG. 2 conceptually shows the relationship between the rate pulse RP, which is a synchronizing signal for scanning the acoustic beam, and the received echo signal ES. As shown in the figure, while the rate pulse RP is being generated, no acoustic beam is emitted or received. Therefore,
While this rate pulse RP is being generated (a period within the pulse width of the rate pulse RP), there is no need to write image information to the input buffer 3, and the output of the A/D converter 2 is "0" during this period. In the present invention, the input buffer 3 is erased using this period.

FIG. 3 shows the operational concept of the main parts of this embodiment. As shown in the figure, the echo signal ES is sampled by N sampling clocks, sequentially A/D converted by the A/D converter 2, and inputted. The image data is stored in a buffer 3 and transferred to an image memory 4. Input buffer 3
Address counter 12a for writing data to outputs the write address of virtual memory IM including input buffer 3.

First, when the image position to be moved is set by the image position signal generating device 13, a corresponding analog signal is converted into a digital value by the A/D converter 14 and provided to the code converter 15. The code converter 15 outputs 0 to 0 corresponding to the set image position.
A digital signal having a value of 2N-1 (decimal number) is output as preset data PD to the address counter 12a of the input buffer controller device 12. Here, if we consider a case where a value of N-n (n>0) is set as the preset data PD, the rate pulse RP in the transmitter/receiver 1
After the memory contents of the input buffer 3 are erased by writing erase data within the period in which the error occurs, the address counter 12a outputs the sampling pulse of the echo signal EC from the preset data N-n.
Counting of SP is started, and the count value up to 2N-n-1 is given to the input buffer 3 as an address. From the above conditions, the values from N-n to N-1 are invalid as addresses for input buffer 3, and in reality, the values from n+ of sampling clock SC
This means that addresses are given to the input buffer 3 from the first address. That is, after the sampling of echo information is started in the A/D converter 2, the (n+1)th and subsequent sampling data are stored in the first and subsequent areas of the input buffer 3, and the Nth sampling data is stored in the N+1 area of the input buffer 3. −
After being stored in the (n-1)th area, the sampling clock SC is stopped and the address counter 12a is reset. Therefore, the N-nth and subsequent areas of the input buffer 3 remain erased within the period of the rate pulse RP and are not updated. Therefore, when the data in the input buffer 3 is transferred to the image memory 4, the image memory 4
The previous data will not remain in the area where no image data exists after the movement, and will be erased.
In this way, the image position on the image memory 4 can be moved extremely efficiently. FIG. 4 conceptually shows the above operation.

In the above, we have explained the case where the image is moved upward in FIG.
>0), and a conceptual diagram of the operation in this case is shown in FIG. At this time, the address counter 12a is reset after counting 2N-1 and starts counting again from 0.

In this way, when moving an image, the previous data can be erased and erased by writing data to the small capacity input buffer 3 without erasing the previous data or changing the write address in the large capacity image memory 4. Since the write address is changed, not only the write address can be changed very easily, but also the previous data can be erased in a short time. and,
By using this short-time erasing function, the previous data can be erased (by writing erasing data) within the rate pulse period between the echo signal input periods, so the echo signal can be erased without interrupting imaging. The image can be moved on the screen, and it is also possible to move the image continuously and smoothly in so-called real-time display.

It should be noted that the present invention is not limited to the embodiments described above and shown in the drawings, but can be implemented with various modifications without changing the gist thereof.

For example, in the above embodiment, in order to erase the memory contents of the input buffer 3, a high speed clock FC of 2N cycles or more is applied to the address counter 12 during the rate pulse period.
However, if the count is always started from N during erasing, a high-speed clock FC of N cycles or more can be used during the rate pulse period. Further, the erasure is not necessarily limited to the rate pulse period, but may be performed within the interval in which echo signals are received, and it is sufficient that such echo signals are not received at least slightly before or after the rate pulse RP. If there is a period, erasing may be performed within the period including that period and the rate pulse period.

In addition, the above-mentioned method can be applied to other ultrasound imaging devices other than ultrasound diagnostic equipment, and the displayed echo image is not limited to a B-mode image, that is, a tomographic image; for example, when displaying an M-mode image, etc. It can also be applied to

As detailed above, according to the present invention, the image position of the echo image can be moved extremely smoothly without interrupting the image display in practice, and as a result of the image movement on the image memory, the echo image may deviate from the image area. It is possible to provide an ultrasonic imaging device that can smoothly erase parts.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIGS. 2 to 5 are diagrams for explaining the embodiment. 1... Transmission/reception device, 2, 14... Analog-digital converter (A/D converter), 3... Input line buffer memory (input buffer), 4...
Image memory, 5... Output line buffer memory (output buffer), 6... Digital-analog converter (D/A converter), 7... Mixing device, 8...
Television display device (TV display device), 9... Image memory control device, 10... Output buffer controller device, 11... Synchronization signal generator,
12...Input buffer controller device, 12a
. . . address counter, 13 . . . image position signal generator, 15 . . . code converter.

Claims (1)

[Claims] 1 Sequentially writes sound wave echo information obtained by sending sound wave pulses into the subject and receiving the echoes to an image memory via an input line buffer memory to form image information in the image memory, and In an ultrasonic imaging device that reads out image information stored in an image memory and displays an echo image, the data in the input line buffer memory is stored in the input line buffer memory within a period between receiving echoes corresponding to each sound wave pulse. After writing the erase data for erasing the memory contents, the write address of the input echo information to the input line buffer memory is changed according to the image position information set externally, and the input line buffer memory is An ultrasonic imaging apparatus characterized by comprising means for writing echo information in a portion and supplying the echo information to the image memory together with erased data for the portion in which no echo information is written.