JPH01500294A - Ultrasonic imaging device and imaging method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Ultrasonic imaging device and imaging method The present invention relates to an ultrasonic imaging device and an imaging method.

Ultrasound imaging is a technique used in non-destructive inspection and testing and medical diagnostics.

Using ultrasonic acoustic waves Conventional devices that form a plane image that includes the ultrasonic beam axis B-scan (B-5can) method or a plane image perpendicular to the ultrasound beam is formed. One of the so-called C-scan (C-5can) methods is employed.

According to the invention, a line is sent into the object to focus the acoustic wave pulse signal; linearly focused, with a linear focus that intersects the linear focus of the transmitter Any target encountered within the object by the transmitted signal using the receiver It also detects the return from the object; controls the transmitter and receiver to scan the surface of the image: the step of creating an image from the signal received by the receiver An ultrasound imaging method is provided.

The present invention, referred to as the U-scan method described below, is a B-scan method with high resolution. or focus on the altitude of either the C-scan plane or some intermediate plane. It creates an image.

Further, according to the present invention, linearly focused acoustic wave pulses (aline fo cused acoustic wave pulse)) Transmitter: A focal point arranged to have a linear focal point that intersects the linear focal point of the transmitter at an intersection point. Acoustic wave pulse receiver to be aligned: Scan the plane where the image is formed at the above intersection point. control means for controlling the transmitter and receiver to produce an image; An ultrasound imaging device is provided comprising display means controlled by a receiver.

The invention will be explained by way of example with reference to the drawings, in which FIG. Figure 2 shows the transmitter, Figure 2 shows the acoustic wave receiver, and Figure 3 shows the combined acoustic wave. The transmitter and receiver parts are shown in Figure 4, which uses an acoustic lens for focusing. 5 to 9 represent the operation of the device according to the present invention (operat 1 on). The figures show the invention for the inspection of an entire volume of a test object. FIG. 10 is a block diagram of an apparatus according to the invention, in which the first FIG. 1 is a block diagram of another embodiment of the present invention.

Here, FIG. 1 shows an ultrasonic pulse signal transmitter l with a phase array (pha Focus the output of element 2 onto line fT using the sed array) technique. It is made up of a plurality of elements 2 arranged to work in this manner. Figure 2 is super A sound wave receiver 3 is shown, arranged to receive sound waves from the line target fR. It consists of a plurality of elements 4. Scanning the target to be imaged Transmitter 1 and receiver 3 can be placed side by side or one side It is preferable that the linear focus f7 and rR intersect. Alternatively, intersect at right angles and determine the intersection point P (see Figure 4). During operation, the transmitter Each pulse sent from the target is the receiver if the target is present at the intersection point This signal is received by receiver 3. The return is used to create an image of the target on a visual display (No. 10, (See Figure 11). The transmitter and receiver are used to create a complete image of the target. Focusing control of the seater 3 focuses either line f7 or line fR. Keep it stationary at first, then scan the other line along one line above. , thereby creating a series of intersection points P to form one line on the display device. It is carried out by sea urchins. The initial stationary line is then advanced by a predetermined amount. By going to a new position and repeating the scanning of the other line A second line is created on the display. This procedure is performed using This is repeated until a complete matrix of points P is formed and the result is shown on the display. A complete image of the plane is created.

The linear focus that is first kept stationary is similar to C-scan, but the focusing allows for higher resolution. of the transmitter to create a high resolution, orthographic image. Proceed in the plane perpendicular to the axis, or as in B-scan, but focus as above. Changing the focal length to create higher resolution coaxial images Therefore, it is sufficient to proceed within a plane parallel to the axis. In addition, the linear focus that was first made stationary is In order to create slope scanning, it is possible to shift in the two-direction coupling state described above. stomach. In principle, any arbitrary surface can be scanned and imaged.

After either face is fully scanned, the scanned plane is parallel to itself. shifted, with an appropriate shift of the display device so that a certain volume is scanned. A pseudo three-dimensional image (pseudo-3Dimage) is created.

As mentioned above, transmitter 1 and receiver 3 may be placed side by side, or They may be stacked and bonded to each other. In addition, as shown in Figure 3, a transformer The transmitter and receiver are connected to a substrate having electrodes 11 and 12 on opposite sides. rate) 10, and the electrodes 11 and 12 are formed by grooves 13 in the substrate IO. groove 13 formed as a unitary structure that serves to reduce interference. Good too. Suitable materials for making transmitters and receivers are well known, e.g. stone. piezoelectric crystals such as lithium sulfate, Piezoelectric materials such as barium tannate, lead zirconate/titanate, and lead metaniobate materials such as piezoelectric ceramics and piezoelectric plastic materials such as PVDF.

It is also possible to use a combination of materials, for example a receipt made of plastic material. A ceramic transmitter coupled with a bar may also be used. If made of plastic material When a substrate is used, the electrodes are screen printed or deposited using a mesh. position) or deposit one electrode sheet first and then It can be formed by coating by etching to obtain a suitable element.

For the device shown in Figure 3, the grooves 13 simply separate the electrodes into elements. However, if the interference effects are removed by subsequent signal processing to create a visual display, If so, the groove 13 can be omitted. For attenuation purposes, any transmitter or receiver or a combination thereof, the back surface is covered with tungsten steel in a known manner. covered with a layer of a known suitable material such as resin with the addition of a heavy material such as powder. It's okay. Other materials found to be suitable for such damping purposes include: Dental amalgam and tungsten powder with or without alloys There are indium with and without added indium.

Transmitters and receivers other than piezoelectric devices may perform the method according to the invention. I know it's used for.

The method and apparatus described above utilizes an electrical focus to operate the transmitter and receiver. electronic focusing and phase alignment rray) technology.

If only a C-scan is required, a simplified version of the device as shown in Figure 4 can be used. You can use This device uses an acoustic lens 5 to capture images within the object to be imaged. An image of the transmitter 1 is formed at a certain depth.

When element 2 of transmitter l is energized, , it insonifies the linear focus fT, and to the depth of The return from any target at is imaged onto the receiver 3. However However, each element 4 of the receiver 3 is within the target area, that is, one intersection point p Each line of transmitter and receiver elements forming a (pixel) Receive only the returns coming from the linear focus f within the area covered by the intersection of the foci (pick up). The distance of the linear focal point of transmitter 1 within the object Returns from outside distances will be gated off. As a result, the pulse transmitter (p only one ulsetransmitter is required, and it from one element of the data to the next and used to create a visual display. The gate of the receiver 4 is turned on, and the output is converted to a rectified output.

If necessary, an acoustic lens can be used to Used to obtain scanning of an area different from the rear.

Referring now to FIGS. 5 to 9, a thorough inspection of a certain volume of the test object The use of the method according to the invention for

The method described consists of three stages: the first exploration stage involves determining the height of the entire test object; If fast scanning is done at coarse resolution and no target is found, The inspection is over and if the target is found, a second focusing step The transmitter and receiver were discovered and focused on the f-cookinget, and then the third stage On the floor, scanning is carried out according to the contour of the target, which allows the target to be A corresponding image of the image is created on the visual display.

FIG. 5 shows a rectangular box with a defect 21 inside which is the target to be discovered and imaged. 2 shows a test object 2o in the form of a body block.

The exploration phase is performed in one of three ways.

1. One surface of the test object 20 is described by each of the coordinates (xi, yi). is divided into an array of exploration units. Transmitter and receiver elements is activated in parallel (unfocused) and emits a plane wave pulse, and subsequently assign each exploration unit (xi, yi) to its respective exploration column. Look down at 22. Any target that gives a return has coordinates (xi, yi, zi ) is displayed.

2. The transmitter and receiver have the smallest possible focal area, e.g. It is used with deliberately reduced focus to a 5x larger area. and , scanning takes place at correspondingly larger intervals and in shorter times. This way In this way, a volume can be probed with either a coarse B-scan or a C-scan layer. It will be done. Any discovered targets 21 are displayed in the same manner as above.

3. A plane wave pulse is transmitted and the first element in one direction acts as a receiver. CB-A-2160973 and the paper “A realtime high frame rate ultrasonic imaging system'' (G, P, P.

Gunarathne, J., 5zillard, Ultrasonics I international゛85. (London) using the technique described in Visualize target 21 and then do the same with elements in other directions. The resulting image is stored.

In the above operation, only two pulses are utilized, i.e. several hundred microseconds. Two orthogonal projections of the test object 20 are created corresponding to the two directions of the element. It will be done. These two projections are displayed. In simple cases they are themselves is sufficient, but if the target shape is complex, more detail will produce a clear image. It is necessary to carry out a thorough inspection.

In the focusing phase, starting from one of the discovered targets 21, highly focused The forced C scan is in exploration column 22 (exploration option l) or found in the focal volume (exploration option 2), or two orthogonal projections (Exploration option 3) An appropriate exploration plane corresponding to the top of the target determined from (Exploration option 3) xi, yi, zi). Scanning is the top of target 21 continues until it is accurately positioned and imaged.

In the next step, the scanning continues and the transmitted By monitoring Luz's flight time, the distance to target 21 can be determined from the first contact. Since the touch position 23 changes by t, the focal length changes to the outline of the target 21. There are therefore three possibilities for the readjustment and its operation:

a) Mapping the contour of the target 21 in the (X, Y) plane g) (Figure 7).

b) Mapping the contour of the target 21 in the (y,z) plane (FIG. 8).

c)) Contour of the target 21 equidistant from the transmitter, i.e. the (x,y) plane Mapping lines (Figure 9).

Once one target has been imaged, operation continues within the test object 20. Repeated for all targets.

If the scanning results can be stored, the axial projection view (pseudo 3D) is displayed, or a cross section through the desired plane or surface is created and displayed. It will be done.

FIG. 9 shows the method according to the invention for carrying out the method described above with reference to FIGS. 1 to 3. FIG. 2 is a block diagram of such a device.

The device comprises a combined transmitter/receiver 1.3, Each element of the generator 1 is supplied by an individual pulse generator 3°.

This pulse generator 30 is controlled by a timer/phase shift device 31. The device controls the operation of the entire device, and the frame door (frame 5 to It is controlled by a microcomputer 32 which also acts as re). receiver 3 The returns received by the elements are each sent to a preamplifier 33. high speed digi are sent to the processor 36 via respective paths with a timer 34 and a memory 35. The processor 36 combines the received signals and sends them to the microcomputer 32. serves to perform the necessary signal processing before being supplied to the visual display device 37 via The display device 37 communicates with the transmitter/receiver device 1.3 in response to the received signal. Therefore, any detected targets will be displayed.

The above-described apparatus is described above with reference to FIGS. A self-contained (self-) capable of performing (B scan and C scan) It may also be a contained system.

Next, FIG. 11 shows that the method described above with reference to FIG. 4 (C scan only) is carried out. 4 is a block diagram of another device according to the present invention for 5) and equipped with a monitor that serves as a means of peak value detection. It can be supplied as an accessory to an ultrasonic defect detector. Shown in Figure 1O The parts shown in FIG. 11 that correspond to the parts have the same reference numerals.

Regarding this device, the monitor output 51 of the standard defect detector 50 is The defect detector 50 controls a visual display device 37 via a second defect detector 32. From this signal, the microcomputer 32 detects the arrival of the echo. By determining the time, a three-dimensional visual double series is created. Pal The gas generator 30 is operated under the control of a microcomputer 32 to generate power from the device 5o. It is controlled by a device 53 which serves to distribute the trigger signal. Returns are individual This analog signal is sent by the preamplifier 33 to the analog multiplexer 54. The log multiplexer 54 sends signals to the device 5o to produce the visual display and its It is controlled by a microcomputer 32.

If a three-dimensional visual display is not required, the second Output 52 can be omitted.

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Claims (20)

[Claims] 1. A step of sending a focused line of acoustic wave pulse signals into the object, and A linear focusing lens with a linear focus that intersects the linear focus of the transmitter. Use the Seaver to detect any target encountered within the object by the injected signal. The step of detecting the return from the object and scanning the surface inside the object at the above intersection point. controlling the transmitter and receiver to An ultrasonic imaging method comprising the step of creating an image from the received signal. Law. 2. A transformer that scans the face of any target it comes across to the above intersection. The transmitter and receiver controls are The line focus is initially held stationary and the line at the other receiver or transmitter is A focal point is scanned along it, creating a series of intersection points, which are then Give the line of the image to be produced, and advance the initially stationary line by a predetermined amount. and move it to a new position, and repeat the scanning of the other linear focus to find the intersection point. 2 series, giving the second line of the subsequently produced image, and repeating the above steps. repeated until a completed matrix of intersection points is formed. The ultrasonic imaging method according to item 1. 3. The first stationary linear focus above is transmitted by a transducer to create an orthogonal image. Claim 2, characterized in that the blade is advanced in a plane perpendicular to the axis of the blade. Ultrasound imaging method. 4. The first stationary linear focus above is connected to a receiver or transducer that creates the linear focus. In addition to changing the focal length of the transmitter, the zero point distance between the transmitter and receiver can be changed. It is characterized by being able to advance in a plane parallel to the axis of the transmitter by changing the The ultrasonic imaging method according to claim 2 or 3. 5. After scanning either plane, the initially stationary linear focus It is moved to a new plane parallel to the scanned plane, scanning is repeated, and the Therefore, a certain volume part is scanned and a pseudo three-dimensional image is created. An ultrasonic imaging method according to any one of claims 1 to 4. 6. The entire volume within the object is traversed to find any target within the object. A first probing stage in which transmitters and receivers are scanned at coarse resolution; The emitter and receiver are focused on the target discovered in the first exploration stage. a second focusing stage in which the target is imaged; and a subsequent third stage in which the target is imaged. An ultrasonic imaging method according to any one of claims 1 to 5. 7. The first probing stage is a parallel and unfocused transmitter and the receiver to determine the area within the object defined by a specific surface area on the object. Inspect the column and display any targets encountered and require this inspection. to be carried out by repeating for a specific surface area on the object to be The ultrasonic imaging method according to claim 6. 8. The first exploration stage is similar to the third stage, but with transmitter and receiver The degree of focusing is reduced, which allows scanning at relatively large intervals. The ultrasonic imaging method according to claim 6, characterized in that: 9. It is noted that the first exploration step is carried out by two orthogonal projections of the entire object. 8. The ultrasonic imaging method according to claim 7, wherein: 10. An ultrasound imaging method substantially similar to that described by the accompanying drawings. 11. Acoustic wave pulse transmitter that focuses in a line and a transmitter at the intersection A linear focusing device arranged so that the linear focus intersects the linear focus of the an acoustic wave pulse receiver that scans the surface to be imaged at the intersection point. a control means for controlling the transmitter and the receiver, and a control means for controlling the transmitter and the receiver for producing the image. 1. An ultrasonic imaging device comprising: a display means controlled by a bar. 12. The transmitter and receiver each consist of multiple parallel elements. The ultrasonic imaging device according to claim 11, characterized in that: 13. characterized in that the transmitter and receiver are electrically focused The ultrasonic imaging device according to claim 11 or 12. 14. The transmitter and receiver are brought into focus by an acoustic lens The ultrasonic imaging device according to claim 11 or 12, characterized by: Place. 15. The transmitter and receiver are formed as a single structure. The ultrasonic imaging device according to any one of claims 11 to 14 characterized by: . 16. A single unit forming a transmitter and receiver or a transmitter and receiver Claim 11, characterized in that the structure has a layer made of a damping material. 16. The ultrasonic imaging device according to any one of Item 15. 17. The damping material may or may not contain dental amalgam or alloy materials, and Claims characterized in that it is indium with or without the addition of gsten powder. 17. The ultrasonic imaging device according to item 16. 18. Ability to scan an area different from the transmitter area Claims 11 to 1 include an acoustic lens that enables The ultrasonic imaging device according to any one of Item 7. 19. Dental amalgam, with or without alloy materials, and tungsten with a layer of damping material formed from indium with or without powder transducer. 20. What is shown in Figures 1, 2, 3, 4, 10, and 11 Ultrasound imaging device that is substantially the same as the.