JP2011106949A - Ultrasonic image apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To overcome the problem that it is impossible to implement fine positioning at a positioning resolution or less as a movement distance due to one axis movement pulse signal normally transmitted from an axis control section at which a positioning robot can implement positioning. <P>SOLUTION: An ultrasonic image apparatus recalculates a position of an ultrasonic transducer scanned by the positioning robot within a measurement range from a speed of the positioning robot and a time interval of a synchronization signal with regard to a synchronization time of an ultrasonic echo signal as digital data continuously recorded in a storage apparatus, converts the ultrasonic echo signal at a corresponding position into pixel data, plots the pixel data at an image position based on the corresponding position information, and displays it. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ultrasonic imaging apparatus that investigates or analyzes a subject in a nondestructive manner using ultrasonic waves.

An ultrasonic image that generates an image from an ultrasonic echo signal obtained from an ultrasonic transducer that transmits and receives an ultrasonic signal and position information obtained by scanning the ultrasonic transducer using a positioning robot and displays the image on a display device In the device
Conventionally, as shown in FIG. 3, an ultrasonic imaging apparatus is widely used in which damage to a subject is imaged by ultrasonic waves propagating inside or on the surface of the subject 13 and non-destructive inspection is performed.

  When measurement is started by the ultrasonic imaging apparatus, the ultrasonic transducer provided in the positioning robot 2 based on the measurement conditions in the two-dimensional measurement range of the X axis and the Y axis input in advance by the input device 11. 1 is scanned.

  The scanning is performed by the axis control unit 4 converting the axis movement pulse signal into an axis drive signal and outputting it to the positioning robot 2 on the basis of the conditions set for the axis control unit 4 by the computer 9. It is.

  Further, the position monitoring unit 5 outputs a synchronization signal to the pulsar receiver 6 every time the position of the positioning robot 2 monitored via the axis control unit 4 matches the condition input in advance by the input device 11. .

  The pulsar receiver 6 outputs an ultrasonic drive signal to the ultrasonic transducer 1, the ultrasonic drive signal is converted into an ultrasonic pulse signal by the ultrasonic transducer 1, and an ultrasonic medium such as water put in the water tank 12 is used. And transmitted to the subject 13.

  The ultrasonic echo signal reflected from the subject 13 is received by the pulsar receiver 6, converted into digital data by the A / D converter 7, and further converted into pixel data by the computer 9, and preset conditions Is plotted at the display position on the image corresponding to the position calculated by.

  The above operation is repeatedly performed within a scanning range determined by preset conditions, and is displayed on the display device 8 as an image. Alternatively, it is stored in the storage device 10 as an image.

  As an example described above, the cited document 1 describes an ultrasonic deep wound device and an ultrasonic deep wound method using a position monitoring unit. Reference 2 describes an image reading apparatus and an image forming apparatus in which a light receiving element clock and a motor drive clock are generated based on the same clock.

  In these conventional examples, the position signal and the light reception timing are synchronized, and the image resolution is limited to be within the range of the position resolution of the positioning device driven by the motor.

JP 11-023539 JP 2007-243315 JP 2001-178726

  An ultrasonic image that generates an image from an ultrasonic echo signal obtained from an ultrasonic transducer that transmits and receives an ultrasonic signal and position information obtained by scanning the ultrasonic transducer using a positioning robot and displays the image on a display device In the apparatus, the positioning resolution that can be positioned by the positioning robot is the distance traveled when only one pulse of the axis movement pulse signal is transmitted from the axis control unit, and a fine image below the movement distance. It was impossible to obtain resolution.

  The present invention has been made in order to solve the above-described problems, and in the case where the measurement range is widened by being able to measure at a measurement pitch finer than the axial resolution mechanically designed in the positioning robot. In addition, an ultrasonic imaging apparatus having little influence on the measurement time is provided.

In order to achieve the above object, the first means is:
“Ultrasound that generates an image from an ultrasonic echo signal obtained from an ultrasonic transducer that transmits and receives an ultrasonic signal and position information obtained by scanning the ultrasonic transducer using a positioning robot and displays the image on a display device In the imaging device,
A scanning range calculation unit for calculating a scanning range based on the operating conditions of the positioning robot;
It consists of a clock generator that generates a clock signal,
After the ultrasonic transducer has moved to the starting point of the scanning range, it starts a linear movement over the scanning range,
After reaching the starting point of the measurement range of the scanning range, based on the control signal of the computer, the A / D converter starts data acquisition,
The A / D conversion unit receives an ultrasonic echo signal from the transmission / reception circuit in synchronization with the clock signal from the clock generation unit, converts it to digital data, and receives a plurality of signals received in the temporary storage device in synchronization with the clock signal Record the ultrasonic echo signal of
The ultrasonic echo when the end point of the measurement range is reached by the axis control unit and the computer, or when the end point of the measurement range is determined by the number of times the clock signal is input to the A / D conversion unit Stop receiving signals,
A plurality of ultrasonic echo signals recorded in the temporary storage device are extracted by the computer and recorded in the storage device,
For each synchronization time of the ultrasonic echo signals continuously recorded as digital data in the storage device, scanning is performed by the positioning robot within a measurement range from the speed of the positioning robot and the time interval of the clock signal. Recalculate the position of the ultrasonic transducer, convert the ultrasonic echo signal at the corresponding position into pixel data, plot the corresponding position information at the image position, and display it on the display device. Features.

(Action / Effect)
By the first means of the present invention, ultrasonic waveform data can be acquired at timings finer than the positioning resolution of the positioning robot, and images can be acquired at fine timings.

  Next, in concrete description, in order to simplify the description, the operation of the positioning robot will be described as the operation of the X axis on the plane.

That is, if the operation speed of the positioning robot is V and the period of the clock signal is dt, the image resolution r is
r = V × dt [Equation 1]

The acquisition timing of the ultrasonic waveform data, which is the original data of the pixels, can be made finer by shortening the cycle of the clock signal without being affected by the positioning resolution of the positioning robot.

  Further, if the time from when the starting point of the measurement range is acquired from the axis control unit until the subsequent A / D conversion unit starts capturing is dt, the range of pixel deviation is within one pixel.

Further, the number n of image data from the measurement range W is
n = W / r [Equation 2]

The acquisition time T of all data within the measurement range W is

T = n × dt = W / V [Equation 3]
Therefore, the time can be shortened by increasing the operation speed V even in a wide measurement range.

The axis position X for each time is X0 when the start position of the measurement range is X0.
X = X0 + ∫Vdt [Equation 4]

Is required.

  By the way, when the operation speed V is increased, the image resolution r naturally becomes coarse, but by reducing the clock signal period dt, the resolution can be made fine without being affected by the positioning resolution of the positioning robot.

  Thus, even if the resolution of the positioning robot is coarse, it is possible to acquire an image at a timing finer than the resolution without using a fine positioning resolution means again to acquire a fine image.

  Furthermore, since the size of the subject is large, even when it is desired to measure over a wide range, it can be operated at a high speed with a normal resolution, so that the measurement time is not greatly lost. Therefore, in the present invention, an ultrasonic image can be obtained with high resolution without being influenced by the size of the subject.

  Further, when acquiring the positioning information and the ultrasonic echo waveform, it is not necessary to synchronize via the electrical signal in order to obtain the acquisition timing.

  That is, it is only necessary to start the A / D conversion unit at the start point of the measurement range calculated in advance by the scanning range calculation unit from the operating conditions, and then the A / D conversion unit is independent of the positioning signal. Since it is directly connected by the clock signal generated from the clock generator and sequentially records the waveforms in the storage device, it is not necessary to control the timing of acquiring the ultrasonic echo waveform by position monitoring, and accordingly, such a circuit is also unnecessary.

  The second means for achieving the above-mentioned object is as follows: “The clock signal is transmitted at a constant time interval, and the scanning from the operation condition is performed so that the positioning robot within the measurement range operates at a constant speed. The range is calculated, and the position is calculated using the driving condition of the positioning robot and the time interval of the clock signal ”.

(Action / Effect)
As a result of the second means of the present invention, the period dt of the clock signal is constant within the measurement range, and as a result, the distance r between adjacent acquisition pixels is
r∝V
Therefore, it is not necessary to use the image resolution r recalculated each time using the individual time dt. For this reason, since the plot position on the image can be obtained before the measurement from the operating conditions, the calculation for each plot can be simplified.

  Further, since the operation speed V is constant within the measurement range, the distance between adjacent pixels becomes r∝dt from the relationship of [Equation 1], and is recalculated using the operation speed V at each time. It is not necessary to use the image resolution r. Accordingly, the plot position on the image can be obtained before measurement from the operating conditions, so that calculation for each plot is facilitated.

  Furthermore, if the second means of the present invention is used, the image resolution r becomes constant, so pixel data on the image may be plotted at equal intervals, so the position on the image is calculated for each data. There is no need to do.

  The third means for achieving the above object is as follows: “Recalculate pixel values by interpolation from a plurality of pixel values whose positions recalculated from the speed of the positioning robot and the time interval of the synchronization signal are close to each other. And generating an image ".

(Action / Effect)
Here, similarly to the above description, in order to simplify the description, the operation of the positioning robot will be described with respect to the X-axis one-axis operation on a plane.
That is, by the third means of the present invention, the axial position X of each time is calculated by the formula [Equation 4], and the calculated positions are positions on the image that are discretely divided at equal intervals. Even if they do not completely match, calculate the weights from the neighboring pixel values to the position on the image where each pixel value should be plotted, and then consider the weights to calculate the neighboring pixel values. By plotting the pixel values obtained by adding together at corresponding positions on the image, it is possible to construct a fine image even when the distance between adjacent pixels is not equal.

  In the present invention, when acquiring an ultrasonic image, the positioning robot can measure at a measurement pitch finer than the mechanically set axial resolution, so that the measurement time is not significantly affected even when the measurement range is widened. An ultrasonic image generation method and apparatus are provided.

1 is a diagram illustrating a configuration of an ultrasonic imaging apparatus according to an embodiment of the present invention. It is a figure which shows the clock signal transmission timing at the time of the image acquisition of this invention. It is a figure which shows an example of a structure of the conventional ultrasonic imaging device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 shows a main configuration of an ultrasonic imaging apparatus 110 according to an embodiment of the present invention.

  The positioning robot 2 of the ultrasonic imaging apparatus 110 in FIG. 1 is configured in a portal shape composed of an X axis, a Y axis, and a Z axis, and is connected to an ultrasonic transducer 1 that transmits and receives ultrasonic waves, and an ultrasonic wave is transmitted to the lower part. A water tank 12 for placing a liquid such as water that becomes an ultrasonic medium when transmitting / receiving to / from the subject 13 is disposed.

  The positioning robot 2 of the ultrasonic imaging apparatus 110 can position three axes, that is, the X axis, the Y axis, and the Z axis. However, depending on the purpose, the positioning robot having only one axis can achieve the purpose. It is also possible to add a rotation axis θ.

  A subject 13 is disposed in the water tank 12, and the ultrasonic transducer 1 transmits an ultrasonic wave to the subject 13 through an ultrasonic medium such as water filled in the water tank 12 and is reflected from the subject. Receive an ultrasonic echo.

  The transmission / reception circuit 102 operates to transmit ultrasonic waves from the ultrasonic transducer 1 in synchronization with the ultrasonic transmission timing output from the sensor control unit 104.

  The ultrasonic echo signal reflected from the subject 13 is output to the A / D conversion unit 7 via the transmission / reception circuit 102, and the A / D conversion unit 7 is synchronized with the block signal from the sensor control unit 104 or the clock generation unit 103. Then, the ultrasonic echo signal is converted into digital data and recorded in the temporary storage device 108.

  The A / D conversion unit 7 starts the operation of recording continuously in synchronization with the clock signal by the A / D conversion operation start symbol from the computer 9.

  The clock generator 103 outputs a clock signal at the set clock signal output timing. On the other hand, the axis control unit 4 outputs an axis operation pulse signal to the axis drive unit 3 according to the operation condition input by the input device 11.

  The axis operation pulse signal is calculated and set so that the positioning robot 2 can be smoothly accelerated and decelerated or moved at a constant speed within the measurement range.

  By analyzing the shaft movement pulse signal, the position of the shaft from the start to the end of the shaft operation can be calculated based on each time.

  Alternatively, a position detector such as a linear scale is attached to the positioning robot 2, current position information is fed back to the axis control unit 4, and the position of the axis from the start to the end of the axis is measured and obtained every time. You can also.

  The scanning range calculation unit 109 calculates the area of the acceleration / deceleration part so as to obtain the scanning range based on the operating condition input by the input device 11 so that the operating speed within the measurement range is constant. it can.

  In order to further simplify the description, the operation of the positioning robot will be described with respect to a single X-axis operation on a plane. As shown in FIG. 2, when the movement of the X-axis is started, the computer 9 is based on the preset condition or the position information from the axis control unit 4 at the moment when the positioning robot 2 passes the start position of the measurement range. The A / D conversion operation start signal is output to the A / D converter 7.

  Thereafter, the A / D converter 7 performs an A / D conversion operation based on the clock signal. The A / D conversion unit 7 ends the A / D conversion operation in response to an A / D conversion operation end signal from the computer 9.

  After the end, the continuous ultrasonic echo signal converted into digital data by the A / D converter 7 and recorded in the temporary storage device 108 is read by the computer 9, recorded in the storage device 10, and plotted as image data. Are displayed on the display device 8.

The axis position at each time from the start position of the measurement range is calculated based on a preset operating condition or calculated by the axis control unit 4.
That is, the position X of the axis at each time is expressed by [Equation 4],
X = X0 + ∫V · dt, which can be obtained based on preset operation conditions and measured position information.

On the other hand, since the synchronization signal of the A / D converter 7 is a clock signal and is known by separately setting the clock generation time, the ultrasonic echo recorded as digital data in the temporary storage device 108 is used. It can be determined which time the signal corresponds to.
The time corresponding to the ultrasonic echo signal obtained by these times and [Equation 4] is calculated and plotted at the position on the image.
Further, since the time interval of the clock signal is constant, the position X in the X-axis direction can be easily calculated from [Equation 4].
Furthermore, by setting the operating conditions so that the speed is constant within the measurement range, the speed V in [Equation 4] becomes constant, so that the position X of the axis can be easily obtained.
In addition, even when the position X of the axis calculated in [Equation 4] does not completely match the position on the discretely arranged image, the interpolation is performed on the image from a plurality of adjacent pixel values. Can be recalculated and plotted as the pixel value.

  When the positioning resolution of the positioning robot 2 of the ultrasonic imaging apparatus 110 in FIG. 1 is 0.1 mm, the axial velocity V is determined so that the clock signal is generated 100 times while moving 0.1 mm. The resolution function is 1.0 micrometer. Note that the image position resolution used here is different from the image resolution determined by the ultrasonic transducer, and refers to the mechanical position resolution.

  Further, the pixel shift is regarded as a problem only by the accuracy of the start position, but can be separately set or calibrated.

  An ultrasonic transducer scanned by the positioning robot within the measurement range from the speed of the positioning robot and the time interval of the synchronization signal for each synchronization time of the ultrasonic echo signal continuously recorded as digital data in the storage device By recalculating the position of the image, converting the ultrasonic echo signal at the corresponding position into pixel data and plotting it at the position of the corresponding image, thereby making a measurement finer than the axial resolution mechanically designed in the positioning robot Since the measurement can be performed with the pitch, an ultrasonic imaging apparatus method that does not significantly affect the measurement time even when the measurement range is widened can be provided.

DESCRIPTION OF SYMBOLS 1 Ultrasonic transducer 2 Positioning robot 3 Axis drive part 4 Axis control part 5 Position monitoring part 6 Pulsar receiver 7 A / D conversion part 8 Display device 9 Computer 10 Storage device 11 Input device 12 Water tank 13 Subject 102 Transmitting and receiving circuit 103 Clock Generation unit 104 Sensor control unit 108 Temporary storage device 109 Scanning range calculation unit 110 Ultrasonic imaging device

Claims (3)

An image is generated from an ultrasonic echo signal obtained from an ultrasonic transducer (1) that transmits and receives an ultrasonic signal and position information obtained by scanning the ultrasonic transducer (1) using a positioning robot (2). In the ultrasonic imaging device displaying on the display device (8),
A scanning range calculation unit (109) for calculating a scanning range based on the operating conditions of the positioning robot (2);
A clock generator (103) for generating a clock signal,
After the ultrasonic transducer (1) moves to the starting point of the scanning range, it starts a linear movement on the scanning range,
After reaching the starting point of the measurement range (W) in the scanning range, the A / D conversion unit (7) starts data acquisition based on the control signal of the computer (9),
The A / D converter (7) receives an ultrasonic echo signal from the transmission / reception circuit in synchronization with the clock signal from the clock generator (103), converts it into digital data, and stores it in a temporary storage device (108). Record multiple ultrasonic echo signals received in synchronization with the clock signal,
The measurement range (W) when the end point of the measurement range (W) is reached by the axis control unit (4) and the computer (9) or depending on the number of times the clock signal is input to the A / D conversion unit (7). ) To end the reception of the ultrasonic echo signal when determined to be the end position of
A plurality of ultrasonic echo signals recorded in the temporary storage device (108) are extracted by the computer (9) and recorded in the storage device (10),
For each synchronization time of the ultrasonic echo signal continuously recorded as digital data in the storage device (10), a measurement range (W) from the speed of the positioning robot (2) and the time interval of the clock signal. ), The position of the ultrasonic transducer (1) scanned by the positioning robot (2) is recalculated, the ultrasonic echo signal at the corresponding position is converted into pixel data, and the corresponding position information The ultrasonic image apparatus is characterized in that the image is plotted at the position of the image and displayed on the display device (8).   The scanning range is calculated from the operating conditions so that the clock signal is transmitted at regular time intervals and the positioning robot (2) within the measurement range (W) operates at a constant speed, and the positioning robot ( 2. The ultrasonic imaging apparatus according to claim 1, wherein the position is calculated using the driving condition of 2) and the time interval of the clock signal.   An image is generated by recalculating pixel values by interpolation processing from a plurality of pixel values whose positions recalculated from the speed of the positioning robot (2) and the time interval of the synchronization signal are close. The ultrasonic imaging apparatus according to claim 1 or 2.

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