JP2000152932A - Ultrasonic diagnostic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the efficiency of three dimensional scanning of an ultrasonic beam by scanning the ultrasonic wave so that the locus on a plane crossing the ultrasonic beam forms a rosette pattern in scanning a three dimensional area by an ultrasonic beam. SOLUTION: An ultrasonic transducer 200 is equipped on one end of a rotary arm 202 via a suitable packing and the other end of the rotary arm 202 is attached to the rotation shaft of a motor 206. The motor 206 is mounted on one end of a rotary arm 204 whose the other end is attached to the rotation shaft of a motor 208. The mechanism comprising the rotary arms 202, 204 and motors 206, 208 constitutes a rosette pattern generating mechanism. The rosette pattern is formed in a plane vertical to the ultrasonic beam 300. Thus the three dimensional area of the subject 4 is scanned by the ultrasonic beam 300 drawing a locus of the rosette pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ultrasonic beam (b)
eam) Scanning method and apparatus, and ultrasonic imaging method and apparatus, in particular, an ultrasonic beam scanning method and apparatus for scanning a three-dimensional area with an ultrasonic beam, and an ultrasonic beam scanning method and apparatus obtained by scanning a three-dimensional area with an ultrasonic beam Echo
The present invention relates to an ultrasonic imaging method and apparatus for performing imaging by using the method.

[0002]

2. Description of the Related Art When scanning a three-dimensional region with an ultrasonic beam, it is common to combine electronic scanning and mechanical scanning. Electronic scanning is a phased array (phas)
edarray or switched array (switch)
ultrasonic probe (prob) having a d array
e) the ultrasonic beam is electronically scanned
It is done by doing. Mechanical scanning is performed by changing the position and orientation of the ultrasonic probe manually or sequentially by an appropriate scanning mechanism. The mechanical scanning changes the electronic scanning plane of the ultrasonic beam, and scans a three-dimensional area.

[0003] Echo data (echo d) in a three-dimensional area
a), a three-dimensional image is generated. Also, 3
A range gate (range g) at a predetermined depth of the dimensional region
ate), a C-mode (mode) image is generated based on the echo data obtained.

[0004]

A three-dimensional image or C-mode image for one frame of an image display is
This is obtained by performing the mechanical scanning as described above from one end to the other end of the imaging range. However, since the mechanical scanning is much slower than the electronic scanning, the frame rate (fra) is high.
However, there is a problem that the efficiency of imaging is low due to low me rate.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an ultrasonic beam scanning method and apparatus for efficiently performing three-dimensional scanning of an ultrasonic beam, and an ultrasonic imaging method and apparatus. It is to realize.

[0006]

Prior to describing means for solving the problems, a rosette pattern will be preliminarily described. FIG. 13 shows the principle configuration of the rosette pattern generation mechanism. As shown in the figure, the rosette pattern generation mechanism includes two rotating arms (arm) 902 having the same length.
904.

The rotating arm 902 has one end attached to a shaft 906, and rotates about the shaft 906, for example, clockwise in the drawing at a rotation speed f1. Axis 9
Reference numeral 06 is attached to one end of the rotating arm 904.
The rotating arm 904 has the other end attached to the shaft 908,
It rotates around the axis 908 at a rotation speed f2, for example, counterclockwise in the figure. Rotating arm 90
The trajectory of the motion of the two tips forms a rosette pattern.

For example, if the rotation speed f1 is 90 rotations per second and the rotation speed f2 is 50 rotations per second, the rotation arm 9
As shown in FIG. 14, the trajectory of the tip of 02 is a pattern in which the petals open radially, that is, a so-called rosette pattern.

The outermost edge of the rosette pattern is the trajectory of the tip of the rotating arm 902 when the rotating arm 902 and the rotating arm 904 are aligned in the direction in which they extend. The trajectory passing through the center of the rosette pattern is the rotation arm 90 when the rotation arms 902 and 904 overlap.
2 is the trajectory of the tip of FIG. Note that the center of the rosette pattern is on the axis 908.

[0010] Such a rosette pattern is formed in the following order. At some point, the rotating arm 902,
Assuming that the end of the rotating arm 902 is located at a point a of the outermost edge of the rosette pattern as shown in FIG. 15, for example, the end of the rotating arm 902 moves to the center o of the rosette pattern as the rotating arm 902 rotates. While moving clockwise, the rotating arm 904 rotates counterclockwise during that time, so that the tip of the rotating arm 902 draws a locus indicated by an arrow in FIG. Hereinafter, the locus of the tip of the rotating arm 902 is referred to as the locus of the rotating arm 902.

When the rotating arms 902 and 904 overlap, the trajectory of the rotating arm 902 moves through the center o and further toward the outer edge on the opposite side. When it is again aligned with the rotating arm 904, it reaches the outer edge point a ', then reverses and passes through the center o again, reaches the opposite outer edge point a'', and reverses toward the center o. Such a movement of the rotating arm 902 draws three petal-like trajectories that open at substantially equal angles around the center o during one rotation of the rotating arm 904. Hereinafter, the outer edge points a, a ',
Let a '' represent each petal.

The trajectory passing the center o for the third time is directed to the side where the petal a is located, but is shifted to the left side of the petal a from the petal a due to the rotation ratio of the rotating arms 902 and 904. For this reason, when it reaches the outer edge in this direction and is turned back, FIG.
As shown in FIG. 6, the trajectory draws another petal b. Petal b
Is the petal next to petal a counterclockwise. After petal b, petals b ′ and b ″ are sequentially drawn in the same manner as described above. These are the petals a ′ and a ″, respectively, which are adjacent to each other in the counterclockwise direction. Petals b, b ', b''also have petals a,
Similar to a ′ and a ″, there are three petals that open at substantially equal angles around the center o.

In the same manner, each time the rotating arm 904 makes one rotation, three petals which are shifted counterclockwise by a certain angle and opened at substantially the same angle are sequentially drawn. This is shown in order in FIGS. FIG. 17 shows petals c,
FIG. 18 shows trajectories depicting c ′ and c ″, and FIG.
FIG. 19 shows trajectories depicting d ′ and d ″, and FIG.
The trajectory depicting e 'is shown. This last trajectory returns to petal a to complete the rosette pattern.

While the rotation of the rotating arms 902 and 904 continues, the above-described movement is repeated to form a rosette pattern repeatedly. In the case of the combination of the number of rotations as described above, the period of the rosette pattern formation is 0.1 sec.
c. Therefore, the frequency of pattern formation is 10H
z.

The petal shape and the number of petals in the rosette pattern change according to the relationship between the rotational speeds f1 and f2.
For example, when f1 is 290 rotations per second and f2 is 70 rotations per second, a rosette pattern with an increased trajectory density as shown in FIG. 20 is obtained.

The formation of this pattern is also performed by the rotation arm 904
It progresses while drawing a plurality of petals that open at approximately equal angles around the center for each rotation of. The frequency of pattern formation is 1
0 Hz.

The present invention utilizes such a rosette pattern as an ultrasonic beam scanning pattern. (1) According to a first aspect of the invention for solving the above-described problem, when scanning a three-dimensional region with an ultrasonic beam, the ultrasonic beam is scanned such that a trajectory on a plane crossing the ultrasonic beam forms a rosette pattern. An ultrasonic beam scanning method characterized in that:

(2) According to a second aspect of the present invention for solving the above-mentioned problems, when scanning a three-dimensional area with an ultrasonic beam, the ultrasonic beam is formed such that a trajectory on a plane crossing the ultrasonic beam forms a spiral pattern. Is an ultrasonic beam scanning method.

(3) A third invention for solving the above problems is an ultrasonic beam scanning apparatus for scanning a three-dimensional area with an ultrasonic beam, wherein a trajectory on a plane crossing the ultrasonic beam has a rosette pattern. An ultrasonic beam scanning device comprising: an ultrasonic beam scanning unit that scans an ultrasonic beam so as to form the ultrasonic beam.

(4) A fourth invention for solving the above problem is an ultrasonic beam scanning apparatus for scanning a three-dimensional area with an ultrasonic beam, wherein a trajectory on a plane crossing the ultrasonic beam has a spiral pattern. An ultrasonic beam scanning device comprising: an ultrasonic beam scanning unit that scans an ultrasonic beam so as to form the ultrasonic beam.

(5) A fifth invention for solving the above problem is an ultrasonic imaging method for generating an image based on an echo obtained by scanning a three-dimensional area with an ultrasonic beam, The ultrasonic beam scanning in the region is an ultrasonic imaging method characterized in that the trajectory on a plane crossing the ultrasonic beam forms one of a rosette pattern and a spiral pattern.

(6) A sixth invention for solving the above-mentioned problem is an ultrasonic imaging apparatus for generating an image based on an echo obtained by scanning a three-dimensional area with an ultrasonic beam. An ultrasonic beam scanning means for scanning the ultrasonic beam in the three-dimensional area so that a trajectory on a plane crossing the line forms one of a rosette pattern and a spiral pattern. It is a sound wave imaging device.

(Operation) In the present invention, the ultrasonic beam is scanned in a three-dimensional region so that the trajectory on the plane crossing the ultrasonic beam draws a rosette pattern or the like. Due to the nature of the pattern, 3
Scanning of the dimension area is performed by repeating rough scanning of the entire area, and rough information of the entire area is obtained. The locus changes with each repetition, and the density of the locus becomes the finest in a state where the pattern is completed, so that all information of the area can be obtained.

[0024]

Embodiments of the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiment. FIG. 1 shows a block diagram of the ultrasonic imaging apparatus. This device is an example of an embodiment of the present invention. The configuration of the present apparatus shows an example of an embodiment relating to the apparatus of the present invention. An example of an embodiment of the method of the present invention is shown by the operation of the present apparatus.

The configuration of the present apparatus will be described. As shown in FIG. 1, the present apparatus has an ultrasonic probe 2. The ultrasonic probe 2 is an example of an embodiment of the ultrasonic beam scanning device according to the present invention. Further, it is an example of an embodiment of the ultrasonic beam scanning means in the present invention. The ultrasonic probe 2 is used in contact with the subject 4. The ultrasonic probe 2 scans a three-dimensional area inside the subject 4 with an ultrasonic beam and receives an echo.

FIG. 2 shows a schematic configuration of the ultrasonic probe 2. As shown in the figure, the ultrasonic probe 2 has an ultrasonic transducer 200. The ultrasonic transducer 200 is made of a piezoelectric material such as PZT (lead zirconate titanate (Zr)) ceramics (ceramics).

The ultrasonic transducer 202 is formed, for example, in a disk shape. FIG. 2 shows the side surface of the disk.
The lower surface in the figure of the disk serves as a transmitting / receiving surface of ultrasonic waves, and forms an ultrasonic beam 300 toward the subject 4. It is preferable that the surface of the disk be concave in order to improve the convergence of the ultrasonic beam 300.

The ultrasonic transducer 200 is attached to one end of the rotating arm 202 via an appropriate backing member (not shown).
The rotating arm 202 is horizontal in the figure, and the back surface of the ultrasonic transducer 200 is attached to the lower surface thereof. The other end of the rotating arm 202 is a motor (mot)
or) attached to the rotation shaft of 206. Motor 2
The rotation axis of 06 is parallel to the direction of the ultrasonic beam 300. Thus, the rotating arm 202 rotates in a horizontal plane in the drawing.

The motor 206 is attached to one end of the rotary arm 204. The rotating arm 204 is horizontal in the figure, and the back surface of the motor 206 is attached to the lower surface thereof. The other end of the rotary arm 204 is the motor 2
08 is attached to the rotating shaft. The motor 208 is
Casing 210 of ultrasonic probe 2
The back is attached inside. The rotation axis of the motor 208 is parallel to the direction of the ultrasonic beam 300.

As a result, the rotary arm 204 rotates in a horizontal plane in the drawing. The motor 206 rotates the rotating arm 202 in a horizontal plane different from the rotating surface of the rotating arm 204 while rotating together with the rotating arm 204. The motors 206 and 208 rotate in opposite directions. The distance from the center (sound ray) of the ultrasonic beam 300 to the rotation axis of the motor 206 is equal to the distance between the rotation axes of the motors 206 and 208.

Rotating arms 202 and 204 and motor 2
The mechanism consisting of 06 and 208 constitutes a rosette pattern generating mechanism similar to that shown in FIG. The rosette pattern is formed in a plane perpendicular to the ultrasonic beam 300. Thus, the three-dimensional area of the subject 4 is scanned by the ultrasonic beam 300 while drawing a locus forming a rosette pattern.

The number of rotations of the rotary arm 202 is, for example, 540.
0 rpm, the number of rotations of the rotating arm 204 is, for example, 3000
rpm. Thus, scanning along the rosette pattern as shown in FIG. 14 is performed. The scanning cycle is 0.1 sec, and therefore, rosette pattern scanning at a frequency of 10 Hz is performed.

The combination of the rotation speeds of the rotating arms 202 and 204 is not limited to the above. For example, the rotation speed of the rotation arm 202 may be 17400 rpm and the rotation speed of the rotation arm 204 may be 4200 rpm. Thereby, scanning along the rosette pattern as shown in FIG. 20 can be performed. Also in this case, the frequency of the rosette pattern scanning is 10 Hz. Needless to say, a combination of other appropriate rotation speeds may be used.

The casing 210 forms a container for accommodating the rosette pattern generating mechanism. The lower opening in the figure of the casing 210 is sealed with an ultrasonic-permeable flexible film 212 such as a rubber film, and the inside is filled with an ultrasonic wave propagation medium 214 such as water.

Returning to FIG. 1, the ultrasonic probe 2 is connected to the transmitting / receiving unit 6 and the control unit 14. Transceiver 6
Sends a drive signal to the ultrasonic probe 2 to transmit ultrasonic waves. The transmitting / receiving unit 6 also receives the echo signal received by the ultrasonic probe 2. The control unit 14 controls the rotation of the motors 206 and 208 in the ultrasonic probe 2.

FIG. 3 shows a block diagram of the transmission / reception section 6. As shown in the figure, the transmission / reception unit 6 transmits a signal at a transmission timing (tim).
ing) generating circuit 602. The transmission timing generation circuit 602 periodically generates a transmission timing signal and inputs it to the drive signal generation circuit 604. The drive signal generation circuit 604 generates a drive signal based on the transmission timing signal.

The drive signal generation circuit 604 inputs a drive signal to the transmission / reception switching circuit 606. The transmission / reception switching circuit 606 includes:
The drive signal is applied to the ultrasonic transducer 200 of the ultrasonic probe 2. The ultrasonic transducer 200
An ultrasonic beam 300 is generated based on the driving signal.

The transmission / reception switching circuit 606 includes a reception circuit 608.
Is connected. The transmission / reception switching circuit 606 transmits the echo signal received by the ultrasonic transducer 200 to the reception circuit 6.
08. The receiving circuit 608 outputs an echo reception signal based on the input signal.

The receiving circuit 608 includes not only the fundamental wave echo of the transmitted ultrasonic wave but also a second-order or higher-order harmonic echo generated based on the nonlinearity of the ultrasonic wave propagation in the subject. Alternatively, a so-called parametric echo such as a difference frequency echo at the time of transmitting a two-frequency signal may be received.

The transmission of the ultrasonic beam is repeatedly performed at predetermined time intervals by the transmission timing signal generated by the transmission timing generation circuit 602, and the echo is received each time. The transmission and reception of ultrasonic waves are performed while moving the ultrasonic transducer 200 along the rosette pattern. As a result, echo collection for a three-dimensional area in the subject 4 is performed.

The transmitting / receiving section 6 is connected to the echo processing section 8. The transmission / reception unit 6 inputs an echo reception signal for each sound ray to the echo processing unit 8. The echo processor 8 forms image data (data) for each sound ray based on the echo reception signal. That is, by performing logarithmic amplification and envelope detection of the echo reception signal, a signal representing the intensity of the echo at each reflection point on the sound ray, that is, an A scope (scope)
A signal is obtained, and image data is formed using the instantaneous amplitude of the A scope signal as a luminance value.

The echo processing unit 8 is connected to the image processing unit 10. The image processing unit 10 generates an image based on image data input from the echo processing unit 8. FIG. 4 is a block diagram of the image processing unit 10.

As shown in FIG. 1, the image processing section 10 has an input image memory 102. The input image memory 102 stores the image data input from the echo processing unit 8. Since the scanning of the ultrasonic beam is performed three-dimensionally, three-dimensional image data is stored in the input image memory.

Since the three-dimensional scanning of the ultrasonic beam is performed along the rosette pattern, as described with reference to FIGS. , And the rosette pattern is completed with a predetermined number of repetitions (five in this example).

Due to such scanning characteristics, the entire three-dimensional area is roughly scanned each time the above-described repetition is performed, and rough image data for the three-dimensional area is obtained each time. The time per repetition is, for example, 1/5 of the time to complete the rosette pattern, ie, the time to complete the full scan of the three-dimensional area. That is,
A three-dimensional area can be scanned efficiently. .

Hereinafter, this one repetition is referred to as one cycle. One cycle time is 1/5 of the rosette pattern scanning time. Therefore, the frequency of one cycle is five times the rosette pattern scanning frequency. In this example, since the frequency of the rosette pattern scanning is 10 Hz, the frequency of one cycle is 50 Hz. The image data thus obtained is stored in the input image memory 102.

The output data of the input image memory 102 is input to the cross-correlation unit 104. Cross-correlation unit 1
The output data of the whole image memory 106 is also input to 04. The whole image memory 106 stores three-dimensional image data obtained by performing a full scan of the three-dimensional area. The cross-correlation unit 104 calculates a three-dimensional cross-correlation between the input image and the entire image based on the two input data. The cross-correlation unit 104 is, for example, a digital signal (DSP).
al processor). As the input image data to be cross-correlated, the image data for one cycle is used. As the whole image data, a part corresponding to one cycle of the input image data and the image data in the vicinity thereof are used.

The output signal of the cross-correlation unit 104 is input to the displacement / deformation detection unit 108. The displacement / deformation detection unit 108 calculates displacement and deformation of an input image based on an output signal of the cross-correlation unit 104. The displacement / deformation detection unit 108 is, for example, a DSP
Etc. Displacement / deformation detection unit 108
Thus, the amount and direction of the parallel or rotational movement of the input image can be obtained. Further, the amount and direction of expansion and contraction of the input image are obtained.

The output signal of the displacement / deformation detection unit 108 is input to the image correction unit 110. The image data of the entire image memory 106 is input to the image correction unit 110. The image correction unit 110 has a displacement
The entire image data is corrected based on the output signal of the deformation detection unit 108. The image correction unit 110 is constituted by, for example, a DSP or the like. In correcting the image data, the corresponding portion is corrected based on the partial displacement / deformation obtained from the input image data, and the whole image is corrected by extending the portion. Thereby, a new three-dimensional image is formed.

Since the input image data is rough image data of the entire three-dimensional area obtained by one cycle of scanning, the displacement / deformation obtained therefrom is extended to the entire image to form an updated image. An updated image with high validity can be obtained.

The output image data of the image correction unit 110 is input to the output image memory 112. The output data of the output image memory 112 is output to the next stage. The output data of the output image memory 112 is also input to the entire image memory 106 via the switch 114 and written as a new entire image.

Hereinafter, the same processing is performed for each cycle of the ultrasonic beam scanning. The entire image memory 106
, The echo processing unit 8 is switched by switching the switch 114.
Can be stored. This is for writing the same image data as the input image memory 102 into the entire image memory 106 at the beginning of the ultrasonic imaging.

By the image processing of the image processing unit 10, the three-dimensional image is updated every one cycle of the ultrasonic beam scanning. Since the frequency of one cycle is, for example, 50 Hz, the frame rate of imaging can be as high as 50 Hz, while performing mechanical three-dimensional sound ray scanning.

The display section 12 is connected to the image processing section 10. The display unit 12 receives an image signal from the image processing unit 10 and displays an image based on the image signal.
The display unit 12 is, for example, a graphic display (gr).
aphic display).

The above-described ultrasonic probe 2, transmitting / receiving unit 6,
A control unit 14 is connected to the echo processing unit 8, the image processing unit 10, and the display unit 12. The control unit 14 controls the operation by supplying a control signal to each of these units. Further, the control unit 14 is configured to receive various notification signals from each of the controlled units. Ultrasonic imaging is performed under the control of the control unit 14.

An operation unit 16 is connected to the control unit 14. The operation unit 16 is, for example, a keyboard (keyboard).
d) and an operation panel equipped with other operation tools (pane
l). The operation unit 16 is operated by the operator
Is used to input desired commands, information, and the like.

The operation of the present apparatus will be described. The operator touches the ultrasonic probe 2 to a desired portion of the subject 4 and operates the operation unit 16 to perform imaging. Imaging is performed under the control of the control unit 14.

The three-dimensional region of the subject 4 is ultrasonically scanned along the rosette pattern by the ultrasonic probe 2 and the transmitting / receiving unit 6, and an echo is received for each sound ray. Image data is formed by the echo processing unit 8 based on the echo reception signal, and is input to the image processing unit 10.

In the image processing unit 10, the switch 1 is initially set.
14 is switched to the input image data side, and the input image data is stored in the input image memory 102 and the entire image memory 10.
6 are commonly input. As a result, the same image is stored in the input image memory 102 and the entire image memory 106.

Since the images stored in the two memories are the same, no displacement / deformation is detected by the cross-correlation unit 104 and the displacement / deformation detection unit 108, so that the image correction by the image correction unit 110 is not performed. . Therefore, the input image is stored in the output image memory 1 as it is.
12 is stored. The image data of the output image memory 112 is given to the display unit 12 and displayed as a visible image.

When the sound ray scanning along the rosette pattern is completed at least once, the switch 114 is switched to the output image memory 112 side, and that state is maintained thereafter. As a result, the image processing unit 10 updates the image every sound ray scanning cycle as described above. Therefore, the three-dimensional image displayed on the display unit 12 is, for example, 5
Updated at a frame rate of 0 Hz, a substantially real-time three-dimensional display image can be obtained.

The above is an example of capturing a three-dimensional image.
The receiving circuit 608 transmits the echo reception signal to the ultrasonic beam 300.
Sampling at a predetermined distance in the traveling direction of the
If a range gate means (ng) is provided, a C-mode tomographic image can be obtained based on the range-gated echo reception signal. It goes without saying that a C-mode image can also be obtained at a high frame rate.

Instead of forming the ultrasonic transducer 200 with a single piezoelectric plate, for example, as shown in FIG. 5, a two-dimensional array 500 of a plurality of ultrasonic transducers 200 'is used, and As shown in FIG. 5, a transmission beamformer (beamformer) 604 ′ and a reception beamformer 608 ′ are provided.
Local three-dimensional scanning of the ultrasonic beam may be performed by electronic scanning.

In this manner, by combining the electronic scan and the mechanical rosette pattern scan, three-dimensional scanning with a higher sound ray density than that of a single piezoelectric plate, or when the same sound ray density is used, A wider three-dimensional scan can be performed.

When the two-dimensional array 500 is used, the ultrasonic wave is transmitted by a spherical wave or a plane wave, and the echo reception signal is range-gated by RF (radio frequency) for each ultrasonic transducer 200 ′. Then, the C-mode image may be generated by two-dimensional Fourier transform of the memory data. This is preferable in that a C-mode image with high spatial resolution is captured without performing sound ray scanning by electronic scanning.

When a plurality of ultrasonic transducers are used, the ultrasonic probe 2 may be configured as shown in FIG. That is, as shown in the drawing, the ultrasonic transducer 220 having a plurality of ultrasonic transducers is configured to scan the rosette pattern by the scanning mechanism 230.
Other parts are the same as those of the ultrasonic probe 2 shown in FIG. 2, and are denoted by the same reference numerals.

The ultrasonic transducer 220 includes a plurality of ultrasonic transducers 22 as shown in a plan view of FIG.
2 at a predetermined pitch (pit) on the disc-shaped support member 224.
ch) two-dimensionally arranged by p.

The scanning mechanism 230 has a rotary arm 232 to which an ultrasonic transducer 220 is attached at one end, as shown in FIG. 9, for example. The rotary arm 232 is horizontal in the figure, and has an ultrasonic transducer 220
The back of is attached. Note that a bearing or the like is used for attachment. The other end of the rotating arm 232 is a motor 23
6 is attached to the rotating shaft. The rotation axis of the motor 236 is parallel to the direction of the ultrasonic beam 320. Thus, the rotating arm 232 rotates in a horizontal plane in the drawing.

The motor 236 is attached to one end of the rotary arm 234. The rotating arm 234 is horizontal in the figure, and the back surface of the motor 236 is attached to the lower surface thereof. The other end of the rotating arm 234 is the motor 2
It is attached to 38 rotating shafts. The motor 238 is
The back surface is attached inside the casing 210 of the ultrasonic probe 2. The rotation axis of the motor 238 is parallel to the direction of the ultrasonic beam 320.

As a result, the rotary arm 234 rotates in a horizontal plane in the figure. The motor 236 rotates the rotating arm 232 in a horizontal plane different from the rotating surface of the rotating arm 234 while rotating together with the rotating arm 234. Motors 236 and 238 rotate in opposite directions. The distance from the center of the ultrasonic beam 320 to the rotation axis of the motor 236 is equal to the distance between the rotation axes of the motors 236 and 238.

Rotating arms 232 and 234 and motor 2
The mechanism composed of 36 and 238 constitutes a rosette pattern generating mechanism similar to that shown in FIG. However, the lengths of the rotating arms 232 and 234 are significantly shorter than those shown in FIG. The sum of the lengths of the rotating arms 232 and 234 is, for example,
The pitch is equal to or slightly greater than the arrangement pitch p of the two.

Thus, the three-dimensional area of the subject 4 is scanned by the ultrasonic beam 320 of the ultrasonic transducer 222 along a rosette pattern having a small diameter. A similar rosette pattern scan is performed simultaneously by all the ultrasonic transducers on the support member 220. That is, the plurality of ultrasonic transducers share a part of the three-dimensional area and perform the rosette pattern scanning.

When such an ultrasonic probe is used, the transmitting / receiving section 6 has a drive signal generating circuit and a receiving circuit for each ultrasonic transducer. Thus, a rosette scan using a plurality of sound rays corresponding to a plurality of ultrasonic transducers can be performed.

Such an apparatus is preferable in that scanning with higher sound ray density is performed along the trajectory of the rosette pattern than that using the ultrasonic probe shown in FIG. Alternatively, it is preferable that the sound ray density along the trajectory of the rosette pattern is substantially the same in that a wider range is scanned.

The mechanical sound ray scanning is not necessarily limited to the rosette pattern, and may be, for example, a spiral pattern. That is, as schematically shown in FIG. 10, a one-cycle spiral scan is performed along a spiral trajectory A, and a spiral scan is performed along a trajectory B whose starting point is shifted in the next cycle. For example, as shown in FIG. 11, a three-dimensional area to be imaged is scanned by an eight-cycle spiral scan.

Even in this case, three scans in one cycle.
The point that the dimensional area can be roughly scanned is the same as the rosette pattern scanning, and the same effect can be obtained.

FIG. 12 shows a schematic configuration of an example of a scanning mechanism that enables such a spiral scan. As shown in the figure, the scanning mechanism includes a pair of driving plates 252 and 254.
Having. The driving plates 252 and 254 have slits 256 and 258 formed in directions perpendicular to each other.
A shaft 260 passing through both slits is provided.
The back surface of the ultrasonic transducer 200 is attached to one end of 60. The driving plates 252 and 254 can reciprocate in directions perpendicular to the directions of the slits 256 and 258, respectively. Note that the ultrasonic transducer 200 may be replaced with the two-dimensional array 500 or the ultrasonic transducer 220 described above.

In such a mechanism, the driving plate 252,
By causing 254 to perform damped vibrations having phases different from each other by 90 degrees, the ultrasonic transducer 200 can be moved along a spiral pattern. By shifting the drive timing by a predetermined time for each cycle of the spiral scan, a plurality of spiral scans having different trajectories can be sequentially performed. It is needless to say that an expanded vibration may be performed instead of the damped vibration.

[0079]

As described in detail above, according to the present invention, it is possible to realize an ultrasonic beam scanning method and apparatus and an ultrasonic imaging method and apparatus for efficiently performing three-dimensional scanning of an ultrasonic beam. .

[Brief description of the drawings]

FIG. 1 is a block diagram of a device according to an example of an embodiment of the present invention.

FIG. 2 is a schematic diagram of an ultrasonic probe in the device shown in FIG.

FIG. 3 is a block diagram of a transmission / reception unit in the device shown in FIG.

FIG. 4 is a block diagram of an image processing unit in the apparatus shown in FIG.

FIG. 5 is a schematic diagram of a two-dimensional array of ultrasonic transducers.

FIG. 6 is a block diagram of a transmission / reception unit in the device shown in FIG.

FIG. 7 is a schematic diagram of an ultrasonic probe in the device shown in FIG.

FIG. 8 is a schematic diagram of an ultrasonic transceiver in the ultrasonic probe shown in FIG. 7;

FIG. 9 is a schematic diagram of a scanning mechanism in the ultrasonic probe shown in FIG.

FIG. 10 is a schematic diagram of a spiral scan.

FIG. 11 is a schematic diagram of a spiral scan.

FIG. 12 is a schematic diagram of a spiral scan mechanism.

FIG. 13 is a principle diagram of a rosette pattern scanning mechanism.

FIG. 14 is a diagram illustrating an example of a rosette pattern.

FIG. 15 is a view showing a process of forming a rosette pattern.

FIG. 16 is a view showing a process of forming a rosette pattern.

FIG. 17 is a diagram showing a process of forming a rosette pattern.

FIG. 18 is a diagram showing a process of forming a rosette pattern.

FIG. 19 is a view showing a process of forming a rosette pattern.

FIG. 20 is a diagram illustrating an example of a rosette pattern.

[Explanation of symbols]

 2 Ultrasonic probe 4 Subject 6 Transmission / reception unit 8 Echo processing unit 10 Image processing unit 12 Display unit 14 Control unit 16 Operation unit 102 Input image memory 104 Cross-correlation unit 106 Whole image memory 108 Displacement / deformation detection unit 110 Image correction unit 112 Output image memory 200 Ultrasonic transducer 202, 204 Rotating arm 206, 208 Motor 300 Ultrasonic beam

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 2G047 BA03 DA03 DB02 DB03 DB12 DB14 EA00 EA09 GA01 GB02 GB16 GB17 GB23 GB35 GE02 GF00 GF01 GG00 GG01 GG12 GG15 GG21 GG25 GG36 GH07 GH08 GH09 GH11 4C301 BB02 BB13 BB02 BB10 GA01 GB09 GB10 GB14 GB20 GB36 GC02 GC15 GC17 HH52 HH60 JB06 JB07 JB11 JB28 JB34 JC20 KK07 KK17 LL02 LL03 5J083 AA02 AB12 AC07 AC30 AD13 AE08 BA01 BD08 BD11 BD12 BE10 CA01 CA12 CA13 EA15 EA18 EB03

Claims (6)

[Claims] 1. An ultrasonic beam scanning method for scanning a three-dimensional area with an ultrasonic beam, wherein the ultrasonic beam is scanned such that a trajectory on a plane crossing the ultrasonic beam forms a rosette pattern. Method. 2. An ultrasonic beam scanning method for scanning a three-dimensional area with an ultrasonic beam, wherein the ultrasonic beam is scanned such that a trajectory on a plane crossing the ultrasonic beam forms a spiral pattern. Method. 3. An ultrasonic beam scanning apparatus for scanning a three-dimensional region with an ultrasonic beam, wherein the ultrasonic beam scans the ultrasonic beam so that a trajectory on a plane crossing the ultrasonic beam forms a rosette pattern. An ultrasonic beam scanning device, comprising: scanning means. 4. An ultrasonic beam scanning apparatus for scanning a three-dimensional area with an ultrasonic beam, wherein the ultrasonic beam scans the ultrasonic beam so that a trajectory on a plane crossing the ultrasonic beam forms a spiral pattern. An ultrasonic beam scanning device, comprising: scanning means. 5. An ultrasonic imaging method for generating an image based on an echo obtained by scanning a three-dimensional region with an ultrasonic beam, wherein the scanning of the ultrasonic beam in the three-dimensional region includes the steps of: An ultrasonic imaging method, wherein a trajectory on a transverse plane forms one of a rosette pattern and a spiral pattern. 6. An ultrasonic imaging apparatus for generating an image based on an echo obtained by scanning a three-dimensional region with an ultrasonic beam, wherein a locus on a plane crossing the ultrasonic beam has a rosette pattern and a spiral pattern. An ultrasonic imaging apparatus, comprising: an ultrasonic beam scanning unit configured to scan an ultrasonic beam in the three-dimensional region so as to form one of them.