JP2000070266A - Ultrasonic diagnostic system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the synchronization accuracy in an ultrasonic diagnostic system for fetching images in synchronism with biological signals. SOLUTION: In a DSC(digital scanning converter) 32, three frame memories 34, 36 and 38 are provided. The frame memories 34, 36 and 38 are utilized in order and the write of data and the read of the data are performed. The write of the data is executed correspondingly to a transmission/reception frame rate and the read of the data is executed correspondingly to a display frame rate. At the time of writing the data, when R wave pulses are generated in the middle of the write of the data for an (n)-th frame, the same frame memory is utilized again and the write of the data for an (n+1)-th frame is performed. At the time of reading the data, in the case that the write of the data for the (n+1)-th frame is not completed yet at the point of time of completing the read of the data for the (n)-th frame, the data for the (n)-th frame are read again.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to an ultrasonic diagnostic apparatus having a function of forming an image in synchronization with a biological signal.

[0002]

2. Description of the Related Art FIG. 3 illustrates an example of the configuration of a conventional ultrasonic diagnostic apparatus. The probe 10 is an ultrasonic probe that transmits and receives ultrasonic waves. The transmission / reception unit 12 supplies a transmission signal to the probe 10 and
This is means for processing (amplifying, detecting, A / D converting, etc.) the received signal (echo data) from 0. In this example, the transmission / reception frame rate is set to match the display frame rate in order to prevent a time phase shift from occurring in the display frame. The transmission and reception by the probe 10 are executed in synchronization with. The echo data 100 processed by the transmission / reception unit 12 is sent to a DSC (Digital Scan Converter) 14.

On the other hand, an electrocardiographic signal 102 as a biological signal is input to the electrocardiographic measuring unit 13. The electrocardiogram measurement unit 13 recognizes a specific time phase (R wave in this example) in the electrocardiographic signal, and synchronizes with the R wave pulse 104.
Has been generated. After the generation of the R-wave pulse, the transmission / reception unit 12 generates a synchronization flag 106A at the timing when the first vertical synchronization signal 108 is generated, and transmits it to the echo data 10A.
It is sent to the DSC 14 together with 0.

The DSC 14 has a coordinate conversion function, an interpolation function,
It has a frame rate conversion function and the like. In the example of FIG. 3, the DSC 14 includes two frame memories 16, 18 and a memory control unit 20. The memory control unit 20 is a unit that controls writing and reading of data to and from the two frame memories 16 and 18. Is performing the control of reading data. The synchronization flag 106A is stored and read out in the frame memory together with the echo data.
The synchronization flag after reading is indicated by 106B in the figure.

[0005] The display processing unit 21 performs image synthesis processing, D / A
This is a means for performing a conversion process or the like. The data after the display process is sent to the display unit 22, and the ultrasonic image is displayed on the display unit 22 according to the display frame rate. By the way,
The display processing unit 21 may perform processing for all input frames, but performs processing such that only one or a plurality of frames specified based on the synchronization flag 106B is periodically displayed as an image. You may let it. When the electrocardiogram waveform signal is generated in the electrocardiogram measurement unit 13, the electrocardiogram waveform signal is sent to the display processing unit 21 via the DSC 14, where the image is synthesized.

[0006] The 3D image construction system 24 is means for forming a three-dimensional ultrasonic image based on echo data acquired in a three-dimensional area.
, The echo data 100 of the frame at the specific time phase, the vertical synchronization signal 108, and the synchronization flag 106B are sent.
In the 3D image construction system 24, the synchronization flag 10
Echo data of one or a plurality of frames starting with the frame specified by 6B is fetched, and a three-dimensional ultrasonic image is constructed by using them.

FIG. 4 is a timing chart showing the operation of the conventional device shown in FIG. In this conventional device, (B), (C), (D) and (E)
As shown in (1), writing and reading of echo data (and a synchronization flag) are performed in synchronization with the vertical synchronization signal 108. In this case, two planes (storage planes) corresponding to the two frame memories 16 and 18 are used alternately. The reason why data is written and read out in synchronization with the display frame rate is to prevent a seam between transmission and reception frames from appearing in one display frame.

When the R-wave pulse shown in (A) is generated,
At the timing of the next vertical synchronization signal 108,
A synchronization flag A shown in (D) is generated, and the synchronization flag A is temporarily stored in one of the frame memories together with the echo data. Then, as shown in (F), when the echo data is read, the synchronization flag B is also read. Using the synchronization flag, one or a plurality of frames at a specific time phase is used, for example, in three-dimensional image formation (or two-dimensional image display) as shown in (G).

According to the above-described operation, it is possible to capture, for example, one or several frames of images at the end diastole in each cycle of the heart.

[0010]

Therefore, in the above-mentioned conventional apparatus, although the image display or the image collection synchronized with the R wave can be performed, the transmission and reception frame rate is controlled by the display frame rate, and the transmission and reception frame rate is independent. There was a problem that can not be set. In addition, as shown in FIG. 4, since a frame is not fetched unless a vertical synchronization signal is generated after an R-wave pulse is generated, a maximum time delay of, for example, 33 msec occurs during that time (display frame rate). Is 30 Hz), there is a problem that the time from the desired timing to the frame acquisition timing cannot be ignored.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object the object of acquiring data in synchronization with a biological signal, from generation of a trigger based on the biological signal to acquisition of data. The goal is to make the time lag as short as possible.

Another object of the present invention is to enable the transmission / reception frame rate to be set independently of the display frame rate.

[0013]

In order to achieve the above object, the present invention provides a biological signal measuring means for measuring a biological signal, a trigger signal generating means for generating a trigger signal synchronized with the biological signal, and Transmitting / receiving means for capturing data at a transmission / reception frame rate in synchronization with a trigger signal; a memory unit including three or more frame memories in which writing and reading of the data are sequentially performed; and a frame memory in the memory unit Means for sequentially writing and writing data to the selected frame memory, the writing control means for writing data at the transmission / reception frame rate in synchronization with the trigger signal, and the completion of data writing in the memory unit. Means for sequentially selecting the selected frame memories and reading data from the selected frame memories. Read control means for reading data at a frame rate, and display means for displaying the read data at a display frame rate, wherein the write control means includes: When a trigger signal is input, the same frame memory is used again to write data for the (n + 1) th frame, and the read control means sets the (n + 1) th data when the reading of data for the (n) th frame is completed. If the writing of data for the frame has not been completed, the data for the n-th frame is read again.

According to the above configuration, three or more frame memories are provided in the memory unit, and data writing and reading are performed by using these in order. In this case,
When the trigger signal based on the biological signal is generated, the frame memory currently used for writing (during writing) is released in response to the trigger signal, and the data of the next frame is stored in the frame memory. . That is,
Writing of data to the frame memory is executed according to the transmission / reception frame rate using the trigger signal as a reset signal, and data writing is executed regardless of the display frame rate. For this reason, it is assumed that writing of the next frame is not completed at the time of reading data, and in such a case, data of the same frame is repeatedly read. By performing the above control on the premise of three or more frame rates, the transmission and reception frame rate can be set independently of the display frame rate. According to the above control, data reading is synchronized with the display frame rate, so that no seam occurs in the display frame. It is desirable to provide three frame memories in consideration of realizing the above control and the cost of the apparatus.

In a preferred aspect of the present invention, the biological signal is an electrocardiographic signal, and the trigger signal is generated in synchronization with a predetermined time phase.

In a preferred aspect of the present invention, a synchronization flag means for generating a synchronization flag indicating a frame of a specific time phase specified by the trigger signal, and data on a frame of the specific time phase specified by the synchronization flag Is written in any one of the frame memories, the synchronization flag is written to the same frame memory together with the data, and a synchronization flag is written when the echo data is read out from the frame memory. A synchronization flag reading means for reading the flag.

According to the above configuration, since the synchronization flag indicating the beginning of the fetch of the frame is also stored together with the echo data of the frame, the specific frame can be reliably identified even if the writing and reading of the data are asynchronous. .

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a preferred embodiment of an ultrasonic diagnostic apparatus according to the present invention, and FIG. 1 is a block diagram showing the overall configuration. Note that, in FIG. 1, the same components as those shown in FIG. 3 are denoted by the same reference numerals.

The probe 10 is an ultrasonic probe for transmitting and receiving ultrasonic waves. The probe 10 has an array vibrator including a plurality of vibrating elements. An ultrasonic beam is scanned by electronically scanning the array transducer, thereby forming a two-dimensional scanning surface. Here, the transmission / reception frame rate related to the scanning plane formation is:
It is set according to various parameters such as a diagnosis depth and a scanning range set by the user. In a conventional apparatus that needs to eliminate a time phase shift of an image generated in a display frame, control for synchronizing a transmission / reception frame rate with a display frame rate is performed. However, according to the apparatus according to the present embodiment, The transmission and reception frame rate can be set asynchronously with respect to the display frame rate.

The transmission / reception section 12 is a means for supplying a transmission signal to the probe 10 and processing a reception signal from the probe 10. The processing includes amplification, detection and A / D
Each process such as conversion is included. The echo data 100 generated by this process is sent to a DSC (Digital Scan Converter) 32.

An electrocardiographic signal 102 as a biological signal is input to the biological unit 13. The electrocardiographic signal 102 is an output signal from an electrocardiographic sensor attached to the living body, and the biological unit 13 generates an R-wave pulse 104 based on the electrocardiographic signal 102. That is, a specific time phase in the electrocardiographic signal 102, that is, an R wave is specified, and a pulse indicating the R wave is output as an R wave pulse 104. This is performed, for example, when displaying an image of an organ such as the heart, in order to periodically and repeatedly display an image at a specific time phase or to form a three-dimensional image using such a periodic image. It is.

In the transmitting / receiving section 12, the R-wave pulse 10
4 is input, ultrasonic wave transmission / reception control synchronized with the R-wave pulse 104 is executed, and the R-wave pulse 104
The synchronization flag 106A indicating the frame formed immediately after the occurrence of the error is generated. That is, if the R-wave pulse 104 is generated during transmission / reception of a certain frame, transmission / reception is interrupted by the input of the pulse, and transmission / reception of a new frame is performed.

The DSC 32 is a means having various functions such as a coordinate conversion function, an interpolation function, and a frame rate conversion function for echo data. In the present embodiment, D
The SC 32 has three frame memories 34, 36, 38. Each of the frame memories 34, 36, and 38 has a storage area of plane 1, plane 2, and plane 3, respectively. The memory control unit 40 is a unit that controls writing and reading of data to and from the frame memories 34, 36, and 38. Here, as described later in detail, data writing is performed according to the transmission / reception frame rate, while data reading is performed according to the display frame rate. That is, writing and reading of data are performed asynchronously. That is, three frame memories are provided to realize such control. Of course, three or more frame memories may be provided when performing other image processing, for example.

When writing data, the memory control unit 40 sequentially selects each of the three frame memories and writes the data to the selected frame memory. In this case, if the R-wave pulse 104 is generated during data writing, the contents of the frame memory being written are reset as a result, and the echo data of the next new frame is written to the frame memory. Thereafter, the writing of the echo data is executed at the transmission / reception frame rate according to the R-wave pulse 104.

On the other hand, when reading data,
Normally, data is sequentially read from the frame memory in which data has been written, but when data is not completely written to the next frame memory when data is read from the next frame memory. , The control of reading out the data of the same frame again from the immediately preceding frame memory is executed. That is, as described above, since the transmission / reception frame rate is made asynchronous with the display frame rate, frame loss is prevented by re-reading such data.

When echo data is read from the frame memory, the synchronization flag stored in the same frame memory is also read. The synchronization flag after the reading is indicated by reference numeral 106B in the figure.

In the display processing section 21, the vertical synchronizing signal 108
Has been generated, and the vertical synchronization signal 108 of the
2 and to the 3D image construction system 24. In the DSC 32, the vertical synchronizing signal 108 is used as a synchronizing signal when data of each frame is read.

The display processing section 21 has an image synthesizing function, a D / A conversion function, and the like. The display processing unit 21 has a DS
The echo data 100 and the synchronization flag 106B read from C32 are input. The display processing unit 21 sends the echo data of each frame output from the DSC 32 to the display unit 22 when the display unit 22 continuously displays images. On the other hand, when displaying only a frame at a specific time phase, processing is performed only on one or more frames starting from the frame specified by the synchronization flag 106B, and image display is performed only on the one or more frames. Have done it.

This is the same in the 3D image construction system 24. In this system, the processing of the three-dimensional ultrasonic image is performed using one or a plurality of frames specified by the synchronization flag 106B as necessary. It has been done.

According to the above-described processing, for example, one or a plurality of frames of a specific time phase can be repeatedly displayed or formed in each cycle of the heart. In this embodiment, in particular, the synchronization accuracy is extremely enhanced. Therefore, it is possible to match the time phase of the frame to be displayed for each cycle with high accuracy. Therefore, for example, when displaying an image of a valve in the heart, it is possible to repeatedly observe the maximum open state of the valve, and the position of the displayed valve, that is, the displayed time phase is periodically changed as in the related art. It is possible to deal with the problem of being different.

FIG. 2 is a timing chart showing the operation of the apparatus shown in FIG.

As shown in (C), data writing is performed according to the transmission / reception frame rate. on the other hand,
As shown in (E), data reading is executed in synchronization with the vertical synchronization signal shown in (B). here,
When the R-wave pulse shown in (A) is generated, as shown in (C), writing of data to a certain frame memory is stopped, and writing of data of the next frame to the frame memory is immediately started. Will be.
On the other hand, a synchronization flag A is generated as shown in FIG. After the generation of the R-wave pulse, the data of each frame is sequentially written to each frame memory in synchronization with the transmission / reception frame rate triggered by the R-wave pulse.

On the other hand, at the time of reading, when the reading of the echo data of the next frame is attempted after the reading of the echo data of a certain frame is completed, as shown in FIG. If the memory is in a state before the completion of the data writing, the reading of the echo data from the original frame memory is executed again. In FIG. 2, data reading from plane 1 is performed twice. Thereafter, the writing of data for the next frame is completed, and thereafter, the echo data of the next frame is read.
As shown in (F), the synchronization flag B is read in parallel with the reading.

As shown in (G), the display processing unit 21
On the other hand, in the 3D image construction system 24, data of one or a plurality of frames is captured according to the synchronization flag B.

In the embodiment of FIG. 1, theoretically, the time delay from the writing R-wave pulse to the start of writing data to the frame memory is zero, but in an actual circuit, the R-wave pulse is input. If the transmission / reception unit is transmitting / receiving a beam at the stage, the transmission / reception operation (reset operation) for writing data to the frame memory is started after the completion of the beam transmission. Delay occurs. However, as a result of the actual measurement, the maximum time delay is as small as 2 msec. That is, as described above, in the conventional device that captures a frame in synchronization with the display frame rate, when the display frame rate is 30 Hz, a maximum time delay of 33 msec occurs in frame units. With the present invention that asynchronously fetches frames, the maximum is 2 msec.
The time delay is c and a beam unit, and the time delay can be greatly reduced as compared with the conventional apparatus.

[0037]

As described above, according to the present invention,
When data is acquired in synchronization with a biological signal, a time lag from generation of a trigger based on the biological signal to acquisition of data can be significantly reduced. Also, the transmission and reception frame rate can be set independently of the display frame rate.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a preferred embodiment of an ultrasonic diagnostic apparatus according to the present invention.

FIG. 2 is a timing chart showing an operation of the device according to the embodiment.

FIG. 3 is a block diagram illustrating a configuration of a conventional ultrasonic diagnostic apparatus.

FIG. 4 is a timing chart showing the operation of the conventional device.

[Explanation of symbols]

Reference Signs List 10 probe, 12 transmission / reception unit, 13 biological unit, 21 display processing unit, 22 display unit, 24 3D image construction system, 32 DSC (digital scan converter), 34, 36, 38 frame memory, 40 memory control unit.

Claims (3)

[Claims] 1. A biological signal measuring means for measuring a biological signal; a trigger signal generating means for generating a trigger signal synchronized with the biological signal; and a transmission / reception for capturing data at a transmission / reception frame rate in synchronization with the trigger signal. Means for writing and reading the data sequentially 3
A memory unit composed of one or more frame memories, and a frame memory in the memory unit are sequentially selected,
Means for writing data to a selected frame memory, wherein the write control means writes data at the transmission / reception frame rate in synchronization with the trigger signal; and a frame memory in which data writing in the memory unit is completed is sequentially selected. Means for reading data from the selected frame memory, comprising: read control means for reading data at a display frame rate; and display means for displaying the read data at a display frame rate. When the trigger signal is input during the writing of the data for the n-th frame, the writing control means uses the same frame memory again to write the data for the (n + 1) -th frame. Reads data for the n-th frame Completed when the writing of data for the n + 1-th frame is not yet completed at the time the ultrasonic diagnostic apparatus characterized by reading the data for the n-th frame again. 2. The ultrasonic diagnostic apparatus according to claim 1, wherein the biological signal is an electrocardiographic signal, and the trigger signal is generated in synchronization with a predetermined time phase. 3. The apparatus according to claim 1, wherein a synchronization flag means for generating a synchronization flag representing a frame of a predetermined time phase specified by the trigger signal, and a frame of a predetermined time phase specified by the synchronization flag. Means for writing the synchronization flag to the same frame memory together with the data when the data is written to any of the frame memories; and when the echo data is read from the frame memory, And a synchronization flag reading means for reading out the synchronization flag.