JPH0584245A - Ultrasonic diagnostic device - Google Patents

Abstract

PURPOSE:To provide the ultrasonic diagnostic device which can obtain a precise image without making a hardware large in size. CONSTITUTION:This ultrasonic diagnostic device is an ultrasonic diagnostic device for converting reflected echo data by coordinates of a sound ray and depth obtained b y an electronic scan to picture element data of rectangular coordinates and displaying it, and it is provided with a sound ray memory 11, a program memory 18, a DSP 15 and an image memory 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to an ultrasonic diagnostic apparatus for converting reflected echo data obtained by electronic scanning by sound ray and depth coordinates into pixel data of orthogonal coordinates and displaying the data. Regarding the device.

[0002]

2. Description of the Related Art In ultrasonic diagnostic equipment, the number of types of probes that can be attached to the equipment tends to increase.
For example, the types of probes are increasing due to differences in scan formats such as linear, sector, and convex, and differences in element pitch, number of elements, frequency, and the like. Therefore, each circuit of the ultrasonic diagnostic apparatus needs to be configured so as to be compatible with different probes. In particular, in a circuit for displaying an image, the circuit is enlarged in order to generate an image according to various modes and to generate image data according to a set enlargement ratio.

Further, in a circuit for displaying an image,
It is necessary to convert the sound ray data into pixel data. Especially B
In the case of a mode image, it is necessary to perform processing for creating a filled image from a group of sample points arranged at equal intervals on a sound ray arranged at equal angular intervals. When performing such processing, it is necessary to fill in between the sample points. When this filled coordinate is generated in the Cartesian coordinate system, the pixel data in the Cartesian coordinate system and the sample points on the sound ray do not match, so the sound ray data (sample point) near the pixel data in the Cartesian coordinate system is searched for. Processing is performed, interpolation processing is performed based on the found sample point data, and pixel data is calculated. Complex operations such as multiplication and division are necessary to perform this mappig processing and interpolation processing, and in order to perform accurate processing at high speed corresponding to the ultrasonic scanning time, it is necessary to further enlarge the circuit. is there.

For this reason, in the conventional apparatus, in order to carry out arithmetic processing in real time for high-speed ultrasonic scanning, approximation calculation by hardware is used. For example, in the interpolation processing, the gap between pixels of adjacent sound rays is interpolated and filled in the horizontal direction of the pixels. In the mapping and interpolation processing by this kind of approximate calculation, the obtained pixel data becomes coarse and the displayed image becomes difficult to see.

An object of the present invention is to provide an ultrasonic diagnostic apparatus capable of obtaining a precise image without increasing the size of hardware.

[0006]

An ultrasonic diagnostic apparatus according to a first aspect of the present invention converts reflected echo data based on sound ray and depth coordinates obtained by electronic scanning into pixel data in orthogonal coordinates and displays the data. The ultrasonic diagnostic apparatus includes a buffer memory, a program memory, a processor, and an image memory. The buffer memory temporarily stores the reflected echo data. The program memory stores a program for calculating each pixel data from the contents of the buffer memory. The processor executes the program stored in the program memory and calculates each pixel data. The image memory stores one screen of pixel data calculated by the processor.

An ultrasonic diagnostic apparatus according to a second aspect of the present invention converts the reflected echo data obtained by electronic scanning by sound ray and depth coordinates into pixel data of orthogonal coordinates and displays the data. It includes a memory, a program memory, a processor, a pixel data calculation circuit, and a selection circuit. The buffer memory temporarily stores the reflected echo data. The program memory stores a program for calculating each pixel data from the contents of the buffer memory. The processor executes the program stored in the program memory and calculates pixel data. The pixel data calculation circuit approximately calculates each pixel data from the reflected echo data. The selection circuit selects either the calculation result of the processor or the calculation result of the pixel data calculation circuit.

[0008]

According to the first aspect of the invention, the reflection echo data temporarily stored in the buffer memory is converted into each pixel data by the processor. The processor executes the contents of the program stored in the program memory.
Therefore, by describing accurate calculation contents in a program and executing it, it is possible to perform various calculations without increasing the size of hardware. Further, even if the content of the calculation changes, there is no need to change the hardware.

In the ultrasonic diagnostic apparatus according to the second aspect of the present invention, the calculation result of the processor and the calculation result of the pixel data calculation circuit can be selected by the selection circuit. Therefore, when a real-time image is desired, the calculation result of the pixel data calculation circuit is selected, and when an accurate image is desired, the calculation result of the processor is selected. You can make a choice.

[0010]

1 shows an ultrasonic diagnostic apparatus according to an embodiment of the present invention. In the figure, various probes 1 can be connected to the diagnostic apparatus main body 1 via a connector. The diagnostic apparatus main body includes a transmission / reception system 2, a scan control system 3,
It is composed of a display system 4 and a control circuit 14.

The transmission / reception system 2 is composed of a transmission control unit 5, a multiplexer 6, a transmission / reception channel circuit unit 7, a reception matching circuit 8, a reception wave shaping circuit 9, and an A / D converter 10. .. The transmission control unit 5 is a circuit that generates a trigger pulse for ultrasonic wave transmission. The transmission / reception channel circuit unit 7 gives a predetermined delay amount to the trigger pulse from the transmission control unit 5 and amplifies the reflected echo signal from the multiplexer 6.

The multiplexer 6 is a circuit for selecting which of the plurality of piezoelectric elements forming the probe 1 is to be driven and which piezoelectric element receives the reflected echo. Is. Reception matching circuit 8
Is for delaying the reflected echo amplified by the transmission / reception channel circuit unit 7 and performing phasing addition. The reception wave shaping circuit 9 is for obtaining analog sound ray data by performing amplification, detection, and filtering processing on the reflected echo subjected to phasing addition. The A / D converter 10 converts analog data into digital data.

The scanning control system 3 comprises a sound ray memory 11, an image memory 12, and a processor section 13. The sound ray memory 11 stores digital data of sample points on the sound ray for one screen, for example, with the sound ray on the horizontal axis and the sample point on the vertical axis. This may be one sound ray segment or plural sound ray segments. The processor unit 13 includes a digital signal processor (hereinafter referred to as DSP) 15, a main memory 16 connected to the digital signal processor 15, an image processing interface 17, and a program memory 18. DSP15 is
Based on the program stored in the program memory 18, various image processing such as mapping processing, interpolation processing and frame correlation is performed.

The main memory 16 stores progress data being processed and various flags. The image processing interface 17 is connected to the control circuit 14 for controlling the diagnostic apparatus main body 1. Various data is given to the DSP 15 via the interface 17. The program memory 18 stores programs for mapping processing, interpolation processing, and various image processing. The image memory 12 stores one screen of pixel data as a result of processing by the DSP 15. The sound ray memory 11 and the image memory 12 are accessed by the DSP 15. Then, the sound ray data is read from the accessed address of the sound ray memory 11, and the pixel data is written to the accessed address of the image memory 12.

The display system 4 includes a television signal generation circuit 19 and C
And RT20. The television signal generation circuit 19
The pixel data stored in the image memory 12 is displayed on the CRT 20 in synchronization with the television signal. Next, the processing contents of the DSP 15 of the ultrasonic diagnostic apparatus configured as above will be described. The DSP 15 operates according to a program stored in the program memory 18.

First, in step S1 of FIG. 2, the main memory 16 and the like are initialized. In step S2, the shape of the figure to be written such as the type of probe and the display direction is read from the control circuit 14 and stored in the main memory 16. Step S
In 3, the position to be displayed, the enlargement ratio,
Load the data such as the type of calculation formula according to the mode,
It is stored in the main memory 16.

In step S4, the Y coordinate of the pixel (x, y) is set to y ₁ . In step S5, the X coordinate is x
Set to ₁ . In step S6, a mapping process for calculating the address on the sound ray memory 11 of the sample point (sound ray data) near the pixel (x, y) is performed. For example, as shown in FIG. 3, as points near the pixel g (x, y),
The addresses on the sound ray memory 11 at four points S _{1 to} S ₄ are calculated. In step S7, the sound ray data of the calculated address is read from the sound ray memory 11.

In step S8, the following calculation is performed from the read four sound ray data, and the value of the pixel g (x, y) is calculated by interpolation processing. In order to calculate this interpolation processing, as shown in FIG. 4, the distances r ₁ and r in the rθ coordinate system are calculated.
Coefficients obtained from ₂ , θ ₁ and θ ₂ {r ₁ / (r ₁ +
r ₂ )} · {θ ₁ / (θ ₁ + θ ₂ )} etc. must be calculated. To calculate each of these coefficients, in FIG. 4, the coordinates (x ₀ , y ₀ ) of the starting point and the coordinates of the pixel g to be interpolated are (x, y), and the sampling points S ₁ and S ₃ from the starting point.
To D ₁ , the distance from the origin to the sampling points S ₂ and S ₄ is D _2, and the distance from the Y axis to the sampling points S ₁ and S 4.
_If the angle to the line containing ₂ is α and the angle to the line containing the sample points S ₃ and S ₄ is β, then r ₁ , r ₂ , θ ₁ , θ ₂
Is calculated by the following formula.

[0019]

[Equation 1]

[0020]

[Equation 2]

[0021]

[Equation 3]

[0022]

[Equation 4]

[0023]

[Equation 5]

Conventionally, such a calculation must be performed by calculation such as square, square root, division, inverse tan, etc., and the hardware circuit configuration becomes complicated. I was doing calculations. However, in the present embodiment, the sound ray memory 11 as the buffer memory is provided, and the software which requires a calculation time in comparison with the hardware circuit can reduce the frame rate to perform accurate calculation.

When the pixel data (luminance data) of the pixel g (x, y) is calculated in this way, the obtained pixel data is written to the addresses x and y of the image memory 12 in step S9. In step S10, the X coordinate is incremented, and in step S11, it is determined whether the incremented x coordinate value x is equal to x _E. This x _E indicates the end coordinate of the X axis. If it is determined that x is not equal to x _E , the process returns to step S6 and the next X
The addresses of the sound ray data of four points near the coordinates are calculated.
When x = x _E , the process proceeds to step S12.
In step S12, y is incremented. In step S13, it is determined whether the incremented y coordinate value y is equal to y _E. This y _E indicates the ending coordinate of the Y coordinate. If it is determined that y is not equal to y _E , the process returns to step S5, and the addresses of the sound ray data at the four points near the next Y coordinate are calculated. If it is determined that y = y _E , the process ends.

That is, in steps S6 to S11, pixel mapping and interpolation processing for one line are performed, and this is performed for all lines. As described above, since the DSP 15 is provided, and the sound ray memory 11 is provided in the preceding stage of the DSP 15 to perform mapping and interpolation processing by software, a complicated calculation circuit becomes unnecessary and the hardware configuration does not become large. Further, when the calculation is performed by hardware, only approximate calculation can be performed, but in this embodiment, highly accurate calculation can be performed. Further, in the case of processing by software, it is possible to calculate not only from four points in the neighborhood but also from nine points or 16 points in the neighborhood. Further, not only the calculation of linear interpolation, but also other calculation formulas such as spline interpolation can be introduced, so that the calculation formulas have expandability.

Further, in the calculation by hardware, there are restrictions on the number of shapes of figures to be written (fan-shaped, etc.), types of image enlargement ratios, etc. This is because the data that is the basis of calculation is stored in a memory such as a ROM, and the capacity of the ROM or the like has an upper limit. However, the calculation by software requires much less original data than the calculation by hardware, so that unlimited kinds of shapes and enlargement ratios can be realized. Further, with the hardware configuration, the circuit configuration becomes large when performing the operation using the floating point, but the floating point operation can be easily realized by using the software.

[Other Embodiments] (a) In the above embodiment, the mapping and the interpolation processing were performed only by software, but as shown in FIG. , Signal processing unit 22
The image memory 12b and the selection switch 23 may be newly added. In this case, the display figure generation circuit 21
Mapping and interpolation processing is realized by hardware with
The signal processing unit 22 performs image processing such as frame correlation and peak value display.

In general, the calculation by software is slower in calculation speed than the calculation by hardware, so that the frame rate is lowered and the image becomes a disassembled photograph. For this reason,
Normally, the selection switch 23 is switched to the upper side, mapping and interpolation processing using approximate calculation by hardware are performed, and the processing result is displayed on the CRT 20 in real time.
When a detailed image is required, the selection switch 23
May be switched to the lower side, interpolation processing and mapping processing by software may be performed, and an accurate processing result may be displayed on the CRT 20. (B) In the above-described embodiment, since each processing is performed by software, the frame correlation and peak detection can be calculated by the DSP 15. For example, in the case of performing frame correlation, after calculating the pixel data in step S8 of FIG. 2, the pixel data one frame before the address (x, y) of the image memory 12 to be written is read, and the read pixel data is calculated. It suffices to perform the correlation calculation from the result and rewrite the correlation calculation result to the address (x, y). Such processing can also be performed by the DSP 15. (C) In the above embodiment, the DSP was used as the processor, but a normal microprocessor may be used. (D) In the above embodiment, the selection switch 23 is provided between the image memory 12a and the television signal generation circuit 19, but it may be provided between the processor unit 13 and the image memory 12. In this case, the image memory 12 can be one, and the image by the hardware and the image by the software can be stored in the image memory 12, and the CRT 20 can compare and display the images. it can.

[0030]

According to the ultrasonic diagnostic apparatus of the first invention,
Since the pixel data is calculated by the processor from the reflected echo data stored in the buffer memory, a precise image can be obtained without increasing the hardware configuration. In the ultrasonic diagnostic apparatus according to the second aspect of the present invention, either the image by the hardware or the image by the software can be selected, so that the real-time image and the precise image can be selected.

[Brief description of drawings]

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

FIG. 2 is a flowchart showing the control contents of the DSP 15.

FIG. 3 is a diagram illustrating pixel interpolation processing.

FIG. 4 is a diagram illustrating a method of calculating an interpolation coefficient.

FIG. 5 is a schematic block diagram of an ultrasonic diagnostic apparatus according to another embodiment.

[Explanation of symbols]

 11 sound ray memory 12, 12a image memory 13 processor section 15 DSP 18 program memory 21 display figure generating circuit 23 selection switch

Claims (2)

[Claims] 1. An ultrasonic diagnostic apparatus for converting reflected echo data obtained by electronic scanning by sound ray and depth coordinates into pixel data of orthogonal coordinates and displaying the converted echo signal. A buffer memory, a program memory that stores a program for calculating each pixel data from the contents of the buffer memory, a processor that executes the program stored in the program memory and calculates each pixel data, An ultrasonic diagnostic apparatus, comprising: an image memory that stores one screen of the pixel data calculated by the processor. 2. An ultrasonic diagnostic apparatus for converting reflected echo data by sound ray and depth coordinates obtained by electronic scanning into pixel data of orthogonal coordinates and displaying the converted echo data, which is temporarily stored. A buffer memory, a program memory that stores a program for calculating each pixel data from the contents of the buffer memory, a processor that executes the program stored in the program memory and calculates each pixel data, A pixel data calculation circuit that approximately calculates each pixel data from the reflected echo data; and a selection circuit that selects one of the calculation result of the processor and the calculation result of the pixel data calculation circuit. Sound wave diagnostic device.