JP2881702B2 - Ultrasound imaging device focusing method and ultrasonic imaging device using this method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of focusing an ultrasonic imager and an ultrasonic imager using the method, and more particularly, to a person who is not accustomed to ultrasonic measurement. However, a focusing method of an ultrasonic survey imaging apparatus capable of easily focusing a focus type ultrasonic probe (hereinafter referred to as a probe) to an inspection position of a predetermined depth, and an ultrasonic survey image using this method Related to the device.

[Related Art] An ultrasonic image search device, which is one of the ultrasonic measurement devices,
It is possible to display a B-scope image or a C-scope image as an internal image of the subject. In this type of imaging device, in order to obtain a clearer image, a desired depth in the subject is determined according to various measurement conditions such as the acoustic characteristics of the probe and its temperature, the medium depending on the temperature, and the speed of sound inside the subject. A focusing operation for setting the focus of the probe is required.

Conventionally, as an operation, a reflected waveform (A-scope image) from a subject is observed using an oscilloscope or the like, and a depth to be measured, a detection gate width, and the like are set based on the observed waveform. In order to adjust the focus, a process of moving the focus type probe up and down with respect to the subject so as to maximize the desired reflected echo and determining its height (positioning in the Z direction) is performed.

In addition, when the acoustic characteristics such as the sound velocity of the subject, the underwater focal length of the probe, the depth to be measured, the detection gate width time, etc. are input to the control device, the calculation is performed to focus on the depth to be measured. In some devices, a focus-type probe is moved to a focus position based on the result.

However, in any case, knowledge of ultrasonic measurement technology, knowledge of the acoustic characteristics of the material being inspected, and knowledge of electronic measurement including the operation of an oscilloscope, etc. are required. At present, it is difficult to use such an ultrasonic measuring device.

[Problem to be Solved] Recently, an ultrasonic imaging apparatus has been used for various inspections, and portable apparatuses have been manufactured. As a result, people who are not skilled in ultrasonic measurement often use this type of device as an inspection device, and there is a demand for a device that can be used and operated easily by anyone.

In the ultrasonic imaging apparatus, it is possible to set data in advance for various operations, but it is not possible to set in advance, in particular, focusing performed in accordance with a subject. Therefore, conventionally, a technician who understands the acoustic characteristics, materials, etc. of the subject uses an electronic measuring instrument to display and observe the state of the ultrasonic wave inside the subject as necessary, while observing the measurement conditions. Focusing is performed in consideration of the above factors.

SUMMARY OF THE INVENTION The present invention addresses the above-described demands and solves this kind of problem. An ultrasonic exploration imaging apparatus that can be easily focused by a person who is not accustomed to ultrasonic measurement or a general person. It is an object of the present invention to provide a focusing method and an ultrasonic exploration imaging apparatus using the method.

[Means for Solving the Problems] A feature of the focusing method of the ultrasonic survey imaging apparatus of the present invention for achieving such an object is that the depth Z of the subject is
The ultrasonic probe is set at a predetermined position in the Z direction in two dimensions of the direction and any one of the X, Y, R, and 方向 directions along the surface of the subject. The echo generator is scanned along one of the selected directions, and a measurement data sequence composed of measurement data obtained from each measurement point is repeatedly obtained by changing the position in the Z direction. The measurement data sequence is normalized based on the measurement data of the maximum peak value in the measurement data sequence, and the distance between the measurement points at a predetermined ratio from the peak value in each of the plurality of measurement data sequences in this normalized state The ultrasonic probe is positioned at the position in the Z direction at the time when the measurement data sequence in which is minimized is obtained, thereby focusing on the echo generating portion.

In addition, a feature of the ultrasonic search imaging apparatus of the present invention is that a scanning mechanism that scans a subject with an ultrasonic probe in two dimensions of the Z direction and any one of the selected directions, Controlling the scanning mechanism, setting the ultrasonic probe at a predetermined position in the Z direction, scanning the echo generator along the selected one direction, and measuring data from each measurement point. Is obtained, and a plurality of measurement data strings composed of the obtained measurement data are obtained by repeatedly changing the position in the Z direction.
Measurement data sampling means for storing in relation to the position in the direction; obtaining a maximum peak value in a plurality of measurement data strings stored by the measurement data collection means; and measuring data based on the measurement data of the maximum peak value. A normalization means for normalizing the sequence, and a measurement data sequence in which a distance between measurement points at a predetermined ratio from a peak value in each of the plurality of measurement data sequences in a state normalized by the normalization means is minimum. Focusing means for positioning the ultrasonic probe at the position in the Z direction at the time of sampling to focus on the echo-generated portion.

[Operation] As described above, scanning is performed in two dimensions according to the depth direction of the subject and the surface direction of the subject (the directions of X, Y, R, and 沿 っ along the surface), and the scanning position in each depth direction By collecting the peak value corresponding to the distance in the plane direction, the measurement data of the characteristic that is maximum at the upper surface position corresponding to the focusing portion is obtained,
Further, since the measured data is normalized with reference to the maximum peak value to determine the probe height (Z coordinate) for obtaining the measured data of the characteristic having the minimum width, the height of the probe at the focal point where the characteristic is the steepest is obtained. (Z coordinate) can be detected. Therefore, focusing can be performed automatically by positioning the probe at the height of the probe obtained thereby.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of an ultrasonic exploration imaging apparatus according to one embodiment of the present invention, FIG. 2 is a flowchart of the focusing process, and FIGS. 3 (a) to (d) are the focusing. FIG. 4 is an explanatory diagram of the principle of FIG.

In FIG. 1, reference numeral 20 denotes an ultrasonic exploration imaging apparatus, and reference numeral 1 denotes a scanning mechanism having an XYZ moving mechanism.
The focus type probe 3 is attached to the scanning mechanism 1 to perform main scanning of the subject 16 in the X direction and sub-scan in the Y direction.
Sub scanning for focusing is performed in the Z direction. The ultrasonic exploration imaging apparatus 20 obtains an A-scope image at each measurement point by this XY scanning, generates measurement data of the B-scope image and measurement data of the C-scope image based on the A-scope image, and generates the B-scope image and the C-scope image. It has a function of displaying a scope image. The subject 16 has an echo-generating portion, such as a defect or a joint, which is to be measured or inspected at a certain depth position from the surface.

The scanning mechanism 1 is controlled by a scan control device 2,
The scan control device 2 is controlled by the image processing device 10 via the interface 7.

The probe 3 is connected to an ultrasonic flaw detector 4, and the ultrasonic flaw detector 4 is composed of a pulsar / receiver or the like, and is transmitted from the transmission terminal to the probe 3 at a predetermined measurement cycle in accordance with a control signal from the image processing apparatus 10. A pulse signal is sent, and an echo reception signal from the probe 3 obtained in response to the generation of the pulse signal is received by a reception terminal, amplified, detected, and sent to the peak detection circuit 5.

The peak detection circuit 5 gates a predetermined position from the detected echo reception signal to detect a peak value of a necessary echo portion. It is output to the A / D conversion circuit 6. The gate position is received from the image processing device 10 via the interface 7 as a setting signal. The peak detection circuit 5 counts time by detecting, for example, a surface echo according to the setting signal. The circuit for that is built in here.

The A / D conversion circuit 6 converts the analog signal of the peak value obtained according to the control signal from the image processing device 10 into, for example, 8
Converts to a digital value in 256 bits
And sends it to the bus 13 as an input data value that can be processed by the microprocessor (MPU) 8.

As a result, a peak value is detected by the peak detection circuit 5 for each measurement point at which the subject 16 is scanned in the X direction by the probe 3 and is passed to the MPU 8. The MPU 8 sequentially stores the data of these peak values in the memory 9 corresponding to each measurement point.

An operation panel (not shown), a memory 9 storing various programs and data, an image memory 11, a display 12, a keyboard (not shown), and the like are connected to the bus 13 in addition to the microprocessor 8. I have. The memory 9 stores an XZ scanning program 9a, a normalization program 9b, a focusing program 9c, a display processing program, and the like. And, in the parameter storage area 9d,
The distance in the X direction and the data of the measurement pitch in the X direction and the Z direction (the height direction of the probe) for the XZ scan input at the time of measurement are stored. The focusing data storage area 9e stores
The peak values obtained by the XZ scanning program 9a are stored corresponding to the position of the Z coordinate and corresponding to each measurement point.

When the MPU 8 executes the XZ scanning program 9a, the positional relationship between the focal length of the probe 3 previously input from the scanning panel and the subject 16 (usually, a predetermined Since the subject 16 is disposed at the bottom of the water tank, the positional relationship is determined by inputting its thickness and the like from the operation panel.) At the measurement start point, first, immediately below the surface of the subject 16 The position of the probe 3 is calculated by calculating the Z coordinate position (height) of the probe 3 so that the focus is positioned at the position.
This position is the center position or the reference position for normal XZ scanning. Then, at the start of the measurement, scanning is performed in the X direction, the measurement points in the X direction are updated in accordance with the measurement pitch in the X direction stored in the parameter storage area 9d, and the peak value of the echo is collected at the position of each measurement point. . At this point, when scanning is performed for the distance in the X direction stored in the parameter storage area 9d, the pitch in the Z direction is updated, and then scanning in the X direction is performed in the opposite direction, and the measurement points are updated at the same pitch. The peak value of the echo is obtained for each measurement point. Note that the echoes collected in this case are echoes within the gate obtained by setting the gate at the focal position of the probe 3.

FIG. 3A is an explanatory view of the measurement state in this case, and it is assumed that there is a defect F or a joint at the measurement position B. In this case, scanning is performed in the X direction so as to include the upper surface of the defect F (see FIG. 3A), and if the focus position of the probe 3 at that time is at the position A or C, the defect F The relationship between the measurement data of the peak value of the echo from the sensor and the distance in the X direction is expressed by a vertical line passing through the origin O as shown by a characteristic 14 in FIG. The curve is symmetric with respect to the axis and has a peak at the position of the origin O. Also,
When the focus of the probe 3 is at the position of the point B, the peak is further increased, and as shown by a characteristic 15 in FIG.

As can be seen from the difference between these characteristics 14 and 15, when the focus of the probe 3 coincides with the position of the defect, the amount of change in the peak value between a certain measurement point and the next measurement point becomes large,
The width of the characteristic curve with respect to the vertical axis passing through the origin O is the narrowest, and its peak is high and narrow. Further, as the distance from the focal position increases, the amount of change in the peak value between one measurement point and the next measurement point decreases, the width of the characteristic curve increases, and the peak decreases.

As a result, the narrowest of these characteristics
It can be seen that the position where 15 is obtained is the in-focus position. Therefore, the measurement data of the peak value of such a characteristic corresponding to each coordinate position in the Z-direction scanning is obtained by the above XZ.
This is the scanning program 9a, and the obtained peak value measurement data is sequentially stored in the focusing data storage area 9e in the order of measurement points in the X direction according to the Z coordinate of the probe 3.

However, even if the measurement data as shown in FIG. 3 (b) is obtained, the width varies depending on the sensitivity at the time of measurement. Further, in these drawings, for the sake of explanation, they are clearly different from each other, but it is actually difficult to distinguish them as the focal point position is approached.

The normalization program 9b is started by the MPU 8 after the execution of the XZ scanning program 9a, and clarifies the difference between these widths by normalizing each measurement data. In other words, when this program is executed by the MPU 8, the MPU 8 executes the measurement of the peak value in the X direction at a certain Z coordinate.
The maximum value is obtained by searching. Then, assuming that the searched maximum peak value is 100%, the peak value of each measurement data is converted into a data of a ratio from the maximum peak value, and the measurement data in the focusing data storage area 9e is rewritten. Thereby, the wide data as shown by the dotted line in FIG. 3 (c) is thereby normalized to the data as shown by the solid line.

The focusing program 9c is started by the MPU 8 after the execution of the normalization program 9b, and when the MPU 8 executes the MPU 8, the MPU 8 moves the 50% position in each Z coordinate of the normalized focusing data storage area 9e. Search for the measurement point of the data located in the X direction and the coordinates x ₁ , x in the X direction from the measurement point.
₂ are calculated, and the value of the difference Δx = | x ₂ −x ₁ | is calculated for each Z coordinate, and stored in the focusing data storage area 9e for each Z coordinate. FIG. 3 (d) shows the relationship between Δx obtained in this case and the distance in the Z direction with the focal point at the origin O, and the value is the minimum value at the focal point. Therefore, by executing this program, the MPU 8 obtains a Z coordinate value at which the Δx is minimized, and positions the probe 3 at the Z coordinate as a focusing position.

Next, the overall focusing process of the image processing apparatus 10 will be described with reference to FIG.

First, in a step, initial information such as the focal length of the probe 3 and the thickness of the subject 16 from the operation panel, the scanning start coordinates in the XZ scan for focusing, and the measurement pitch Px in the X direction and the measurement pitch in the Z direction Pz, X for focusing
Enter the measurement distance Xm in the direction. In this case,
It is assumed that the position of a defect or a joint that generates an echo for performing focusing is included in the above-described measurement distance Xm. Further, data for setting the generation cycle of the transmission pulse of the ultrasonic flaw detector 4, the gate width of the peak detection circuit 5, and the like in advance so as to have the most frequently used setting values for the ultrasonic inspection imaging apparatus are stored in a predetermined area of the memory 9. The data is referred to and set by the MPU 8 via the interface 7. For example, the gate width for peak detection is set to a period of about 0.1 μs to several μs. Although these set values are variable, there is no functional problem even if the set values are not changed, so that there is no need for a setting operation unless specific technical knowledge is given. Further, the gate position is set in accordance with the focal position of the probe 3, and is set as the time after detecting the surface echo. The set time is to calculate the time by calculating the focus position from each measurement position (each Z coordinate) according to the scanning in the Z direction. This processing is performed by the gate setting stored in the memory 9. The calculation is performed according to a processing program (not shown), and the calculation result is provided to the peak detection circuit 5 via the interface 7 by the MPU 8.

In the next step, the XZ scanning program 9a is started, and the probe 3 is moved to the measurement start position for focusing.
The MPU 8 executes this program and executes the program so that the subject 16 and the probe 3 are positioned as a reference position in the height direction (Z direction) of the probe 3 so that the focal point of the probe 3 is equal to the distance directly below the surface. Set the interval of.

In a step, the process enters a loop for waiting for the input of a measurement start key on the operation panel, and detects whether or not to start scanning by inputting the key. When the key is input, in the next step, the XZ scan measurement is started according to the input measurement pitch Px, measurement pitch Pz, and measurement distance Xm in the X direction, and the MPU 8 executes the XZ scan program 9a to execute the XZ scan measurement. Is also scanned in the Z direction together with the update of the measurement point in the X direction (update of the measurement position). As a result, measured data of the peak value is obtained at the position of each Z coordinate corresponding to the measurement point in the X direction, and is stored in the focusing data storage area 9e.

Next, in a step, the normalization program 9b is executed by the MPU 8 to normalize the measured data of the peak value in the focusing data storage area 9e, and in the step, 50% of the measured data of the normalized peak value is measured. X at peak value
The difference Δx between the coordinate values in the directions is calculated, and the probe 3 is positioned at the Z coordinate of the position of the minimum value in the step.

Focusing is completed when this positioning is completed,
In the next step, whether or not scanning is started is detected by a loop waiting for input of a scan measurement start key on the operation panel. Here, when the measurement start key is input, the plane scanning program is executed in the next step, and based on the measurement conditions input in advance, the MPU 8 sets the probe fixed to the above-mentioned focused height. By 3, plane scanning by ordinary XY scanning is performed from the measurement start position. The plane image obtained by this plane scanning measurement becomes a clear image focused on the depth to be measured. Finally, in a step, it is determined whether or not the measurement is completed by inputting an end key or the like.

In this way, since the focus can be automatically adjusted to a position at which an echo is obtained, such as a joint of the subject 16 without focusing, the operator performs a special operation for focusing. You don't have to. Therefore, even without specific technical knowledge about ultrasonics, electronic measuring instruments, etc.
Defect inspection and other measurements can be performed very easily with an ultrasonic imaging device.

By the way, in the step, the difference Δx of the coordinate value in the X direction at the peak value of 50% is automatically calculated, and in the step, the probe 3 is positioned at the Z coordinate of the position of the minimum value. Automatic focusing can be performed, but the graph of FIG. 3D is displayed on the screen of the display 12 to display the minimum Z coordinate, thereby manually positioning the position of the probe 3 at the focused position. You may. Further, the difference Δx between the coordinate values in the X direction is calculated and displayed on the screen of the display 12, and further,
The height of the probe 3 that minimizes the Δx may be obtained by manually performing the positioning in the Z direction in the XZ scan.

As described above, in the embodiment, the scanning is performed in the XZ direction for focusing, but it is needless to say that the scanning may be performed in the YZ direction.

Further, in the embodiment, after normalizing the measurement data, the difference Δx between the coordinate values in the X direction at the position of 50% is calculated, but the ratio is not limited to 50%. Theoretically, any ratio except for 0% and 100% may be adopted. In addition, although shown in%, the same applies when a specific value corresponding to 100% is set without normalizing the maximum value of the peak value, and each measured data is normalized by that value.

In the embodiment, focusing is performed by XZ scanning on the premise of XY plane scanning, but RZ or ΘZ scanning may be performed in R, 回 転 rotation scanning, and the present invention is similarly applied to such scanning. It is possible and is not limited to the form of scanning.

In the embodiment, only one defect position is designated and focused there. However, if there are many defects or joints, XZ and YZ scans can be performed on each of them to obtain a defect. Focusing can be performed sequentially at a plurality of locations in the depth direction inside the sample.

[Effects of the Invention] As can be understood from the above description, in the present invention, the depth direction of the subject and the surface direction of the subject (X,
(Y, R, Θ directions), and by scanning in two dimensions according to the distance, and collecting the peak value at each scanning position in the depth direction corresponding to the distance in the plane direction, the maximum value is obtained at the upper surface position corresponding to the focusing part. The probe height (Z coordinate) for obtaining the measurement data of the characteristic having the minimum width is obtained by obtaining the measurement data of the characteristic that satisfies the following, and normalizing the measurement data with reference to the maximum peak value. The height (Z coordinate) of the probe at the steepest in-focus position can be detected. Therefore, focusing can be performed automatically by positioning the probe at the height of the probe obtained thereby.

As a result, even a person who is not familiar with ultrasonic measurement can easily perform focusing, and can perform accurate measurement in a focused state.

[Brief description of the drawings]

FIG. 1 is a block diagram of an ultrasonic exploration imaging apparatus according to an embodiment of the present invention. FIG. 2 is a flowchart of the focusing process, and FIGS. 3 (a), (b), (c) and (D) is an explanatory view of the principle of focusing. DESCRIPTION OF SYMBOLS 1 ... Scanning mechanism 2 ... Scan control device 3 ... Probe 4 ... Ultrasonic flaw detector 5 ... Echo width detection circuit
6 Time measurement circuit 7 Interface 8 Microprocessor (MPU) 9 Memory 9a XZ scanning program 9b Normalization program 9c Focusing program 9d Parameter storage area 9e Focusing data storage area 10 Image processing device 11
Image memory, 12 ... Display, 13 ... Bus, 16 ...
Subject, 20 ... Ultrasonic measurement device.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) G01N 29/00-29/28

Claims (5)

(57) [Claims] 1. An ultrasonic probe for a subject having an echo generating portion at a predetermined depth, performing flaw detection by focusing a focus type ultrasonic probe on the echo generating portion and displaying an image thereof. In the focusing method of the imaging apparatus, in two dimensions of a depth Z direction of the subject and any one direction selected from X, Y, R, and 方向 directions along the surface of the subject. The ultrasonic probe is set at a predetermined position in the Z direction, and the echo generator is scanned along the selected one direction. The measurement data obtained from each measurement point. Is repeatedly obtained by changing the position in the Z direction, and the measurement data sequence is normalized with reference to the measurement data of the maximum peak value in the plurality of measurement data sequences. A plurality of each said measurement data in the state By positioning the ultrasonic probe at the position in the Z direction when the measurement data sequence in which the distance between the measurement points at a predetermined ratio from the peak value is minimum is sampled, A focusing method for an ultrasonic exploration imaging apparatus, comprising: focusing. 2. The distance between each of the measurement points of the plurality of measurement data strings in the normalized state and the position in the Z direction when the measurement data string corresponding to this distance is collected. The position in the Z direction which is displayed on the display and at which the displayed distance is minimized is selected, and the ultrasonic probe is positioned at the position in the Z direction to focus on the echo generating portion. The method of claim 1, wherein: 3. The method of claim 2, wherein the positioning of the ultrasonic probe in the Z direction is performed manually. 4. An ultrasonic probe which performs flaw detection on an object having an echo generating portion at a predetermined depth by focusing a focus type ultrasonic probe on the echo generating portion, and displays an image thereof. In the imaging apparatus, the subject is defined in two dimensions: a depth Z direction of the subject and one of X, Y, R, and 方向 directions along the surface of the subject. A scanning mechanism that scans with the ultrasonic probe, and controls the scanning mechanism to set the ultrasonic probe at a predetermined position in the Z direction and to set the ultrasonic probe along the selected one direction. The echo generating unit performs scanning to obtain measurement data from each measurement point, and repeatedly obtains a plurality of measurement data strings including the obtained measurement data while changing the position in the Z direction. Means for collecting measurement data stored in relation to Normalization means for obtaining a maximum peak value in the plurality of measurement data strings stored by the measurement data collection means, and normalizing the measurement data string based on the measurement data having the maximum peak value; The position in the Z direction when the measurement data sequence in which the distance between the measurement points at a predetermined ratio from the peak value in each of the plurality of measurement data sequences is minimized in a state normalized by the normalization means is sampled. And a focusing means for focusing on the echo generating portion by positioning the ultrasound probe. 5. The processor further includes a processor, a memory, and a display, and at least a part of the measurement data collection unit, the normalization unit, and the focusing unit execute a program stored in the memory by the processor. The distance between the measurement points of the plurality of measurement data strings in a state normalized by the control of the processor and the Z direction when the measurement data string corresponding to this distance is sampled The ultrasonic search and imaging device according to claim 4, wherein the position and the position are displayed on the display.