Ultrasound diagnostic device and method for controlling the ultrasound diagnostic device

Abstract

The present invention makes it possible to generate an accurate three-dimensional ultrasound image even if an ultrasound probe is moved. In an ultrasound diagnostic device and a method for controlling the ultrasound diagnostic device according to the present invention, a two-dimensional image generation unit shifts the angle or the position of a scan plane using an oscillator array and at the same time generates a plurality of two-dimensional ultrasound images while an ultrasound probe is fixed in contact with a site to be examined in a subject. A movement determination unit sequentially calculates the degree of similarity of at least two of the two-dimensional ultrasound images and sequentially determines whether movement of the ultrasound probe is within reference values in accordance with the degree of similarity. A three-dimensional image generation unit extracts two-dimensional ultrasound images in which the movement of the ultrasound probe was determined to be within the reference values and generates a three-dimensional ultrasound image. A display control unit displays the three-dimensional ultrasound image on a monitor.

Description

[Technical Field]

[0001] The present invention relates to an ultrasonic diagnostic apparatus having a function of generating and displaying two-dimensional ultrasonic images and three-dimensional ultrasonic images, and a method for controlling the ultrasonic diagnostic apparatus. [Background technology]

[0002] For example, Patent Documents 1 to 3 describe ultrasonic diagnostic devices that can generate both two-dimensional and three-dimensional ultrasonic images.

[0003] To generate a 3D ultrasound image, a certain amount of time is required, for example, to generate multiple 2D ultrasound images by transmitting and receiving ultrasound beams while shifting the angle or position of the scanning plane in the elevation direction, and then generate a 3D ultrasound image using these multiple 2D ultrasound images. Therefore, if the ultrasound probe is moved by the user while the multiple 2D ultrasound images used to generate the 3D ultrasound image are being generated, an accurate 3D ultrasound image cannot be generated. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-208592 [Patent Document 2] Special Publication No. 2019-509856 [Patent Document 3] Japanese Patent Application Laid-Open No. 2013-146454 [Patent Document 4] Japanese Patent Application Publication No. 2017-012607 Summary of the Invention [Problem to be solved by the invention]

[0005] For example, Patent Documents 1 and 4 describe determining the movement of an ultrasound probe by calculating a motion vector and a similarity between frames of a two-dimensional ultrasound image, and performing processing according to the determination result. However, Patent Documents 1-4 do not describe selecting frames of multiple two-dimensional ultrasound images to be used to generate a three-dimensional ultrasound image based on the calculation results of motion vectors or similarities between ultrasound image frames.

[0006] An object of the present invention is to provide an ultrasonic diagnostic apparatus and a method for controlling an ultrasonic diagnostic apparatus that can generate accurate three-dimensional ultrasonic images even when the ultrasonic probe is moved. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention provides an ultrasonic probe having a transducer array, a two-dimensional image generating unit that generates a plurality of two-dimensional ultrasound images from received signals obtained by sequentially transmitting and receiving ultrasound beams while shifting the angle or position of the scanning plane using the transducer array, with the ultrasound probe being in contact with and fixed to the examination location of the subject; a movement determination unit that sequentially calculates the similarity between at least two of the plurality of two-dimensional ultrasound images, and sequentially determines whether or not the movement of the ultrasound probe is within a predetermined reference value according to the similarity; a three-dimensional image generating unit that extracts, from among the plurality of two-dimensional ultrasound images, two-dimensional ultrasound images in which the movement of the ultrasound probe is determined to be within a reference value, and generates a three-dimensional ultrasound image; The monitor and An ultrasound diagnostic device is provided that includes a display control unit that displays a three-dimensional ultrasound image on a monitor.

[0008] Here, when it is determined that the movement of the ultrasound probe has exceeded a reference value, the three-dimensional image generating unit does not generate the current three-dimensional ultrasound image, Preferably, when the current three-dimensional ultrasound image is not generated, the display control unit causes the monitor to display the previous three-dimensional ultrasound image immediately before the current three-dimensional ultrasound image.

[0009] and a notification unit that notifies the user of a message indicating that the display of the three-dimensional ultrasound image has not been updated when a current three-dimensional ultrasound image has not been generated; It is preferable that the display control unit displays a message on the monitor when the immediately previous three-dimensional ultrasound image is displayed on the monitor.

[0010] Furthermore, it is preferable that the movement determining unit determines that the movement of the ultrasound probe is within a reference value when the similarity is equal to or greater than a predetermined threshold value.

[0011] and an observation object specifying unit that specifies an observation object present in each of the plurality of two-dimensional ultrasound images based on each of the plurality of two-dimensional ultrasound images, It is preferable that the movement determining section changes the threshold value depending on the object being observed.

[0012] Furthermore, it is preferable that the movement determining section changes the threshold value when at least two two-dimensional ultrasound images include a two-dimensional ultrasound image in which a predetermined object of observation exists.

[0013] Furthermore, when at least two two-dimensional ultrasound images include a two-dimensional ultrasound image in which a predetermined object of observation is present, it is preferable that the movement determination unit changes the threshold value for the two-dimensional ultrasound image in which the predetermined object of observation is present and for a predetermined number of two-dimensional ultrasound images before and after the two-dimensional ultrasound image in which the predetermined object of observation is present.

[0014] Furthermore, it is preferable that the movement determining section changes the threshold value in accordance with at least one of the type of the observation object, the rendering direction of the observation object, and the area of ​​the observation object.

[0015] In addition, it is preferable that the movement determination unit calculates a similarity reference value based on the similarity of two-dimensional ultrasound images for a predetermined number of frames, and determines that the movement of the ultrasound probe has exceeded the reference value when the current similarity is below a predetermined threshold value relative to the similarity reference value.

[0016] In addition, it is preferable that the movement determination unit stores the similarity reference value at the time when the current similarity with respect to the similarity reference value falls below a predetermined threshold, and determines that the ultrasound probe has come to a standstill when the current similarity with respect to the stored similarity reference value falls within the predetermined threshold during a period in which the movement of the ultrasound probe is determined to be within the reference value.

[0017] Furthermore, it is preferable that the motion determining section changes the frame interval between at least two two-dimensional ultrasonic images in accordance with the frame rate at which the plurality of two-dimensional ultrasonic images are generated.

[0018] Preferably, the motion determining unit calculates the similarity while thinning out a predetermined number of two-dimensional ultrasound images at a predetermined frame interval from the plurality of two-dimensional ultrasound images.

[0019] Also, a motion sensor attached to the ultrasound probe; It is preferable that the movement determining unit determines whether or not the movement of the ultrasonic probe is within a reference value based on the similarity and a detection signal of the movement of the ultrasonic probe output from the movement sensor.

[0020] The present invention also provides a method for generating a plurality of two-dimensional ultrasound images from received signals obtained by sequentially transmitting and receiving ultrasound beams using an ultrasound probe having an ultrasound transducer array while shifting the angle or position of the scanning plane using the ultrasound transducer array, in a state where the ultrasound probe is in contact with and fixed to an examination site of a subject; a step in which a motion determination unit sequentially calculates similarities between at least two of the plurality of two-dimensional ultrasound images, and sequentially determines whether or not the motion of the ultrasound probe is within a predetermined reference value according to the similarities; a step in which a three-dimensional image generating unit extracts, from among the plurality of two-dimensional ultrasound images, two-dimensional ultrasound images in which the movement of the ultrasound probe is determined to be within a reference value, and generates a three-dimensional ultrasound image; and a step in which a display control unit causes the monitor to display the three-dimensional ultrasound image. [Effects of the Invention]

[0021] In the present invention, the similarity between frames of two-dimensional ultrasound images is calculated, and whether or not the movement of the ultrasound probe is within a reference value is determined according to this similarity, and a three-dimensional ultrasound image is generated by extracting two-dimensional ultrasound images for which it has been determined that the movement of the ultrasound probe is within the reference value. As a result, according to the present invention, even if the ultrasound probe is moved by the user, an accurate three-dimensional ultrasound image can be generated by extracting two-dimensional ultrasound images for which it has been determined that the movement of the ultrasound probe is within the reference value. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a block diagram illustrating the configuration of an ultrasonic diagnostic apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram illustrating a configuration of a transmission / reception circuit according to an embodiment. [Figure 3] FIG. 2 is a block diagram illustrating a configuration of a two-dimensional image generating unit according to an embodiment. [Figure 4] FIG. 2 is a block diagram illustrating a configuration of a three-dimensional image processing unit according to an embodiment. [Figure 5] 1 is a flowchart illustrating an embodiment of the operation of an ultrasound diagnostic apparatus when generating a two-dimensional ultrasound image. [Figure 6] 1 is a flowchart illustrating an embodiment of the operation of an ultrasound diagnostic apparatus when generating a three-dimensional ultrasound image. [Figure 7A] FIG. 10 is a conceptual diagram illustrating an embodiment in which the angle of the scanning plane is shifted. [Figure 7B] FIG. 10 is a conceptual diagram illustrating an embodiment in which the position of the scanning plane is shifted. [Figure 8] FIG. 10 is a block diagram illustrating the configuration of a three-dimensional image processing unit according to another embodiment. [Figure 9] 1A and 1B are conceptual diagrams illustrating an embodiment of an ultrasound probe with and without motion. [Figure 10] FIG. 10 is a block diagram illustrating the configuration of a three-dimensional image processing unit according to another embodiment. [Figure 11] FIG. 10 is a conceptual diagram of an embodiment showing how a threshold is lowered when calculating the similarity between frames of two-dimensional ultrasound images in which a heart is present. [Figure 12] FIG. 10 is a block diagram illustrating the configuration of an ultrasonic diagnostic apparatus according to another embodiment of the present invention. [Figure 13A] 10 is a graph of one embodiment of a conversion table showing scores versus similarities. [Figure 13B] 10 is a graph of an embodiment of a conversion table showing scores for detection signals of amounts of movement by a motion sensor. [Figure 13C] 10 is a graph of an embodiment of a conversion table showing scores for angle detection signals from a motion sensor. [Figure 14] FIG. 10 is a conceptual diagram of an embodiment showing an ultrasound probe being rotated. DETAILED DESCRIPTION OF THE INVENTION

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The ultrasonic diagnostic apparatus and the method for controlling the ultrasonic diagnostic apparatus of the present invention will be described in detail below based on preferred embodiments shown in the accompanying drawings.

[0024] Fig. 1 is a block diagram showing the configuration of an embodiment of an ultrasonic diagnostic apparatus according to the present invention. The ultrasonic diagnostic apparatus shown in Fig. 1 is a stationary ultrasonic diagnostic apparatus, and includes an ultrasonic probe 1 and an apparatus main body 3 connected to the ultrasonic probe 1.

[0025] The ultrasonic probe 1 scans an examination location of a subject with an ultrasonic beam and outputs sound ray signals corresponding to a two-dimensional ultrasonic image of the examination location. As shown in Fig. 1, the ultrasonic probe 1 includes a transducer array 11 and a transmission / reception circuit 14. The transducer array 11 and the transmission / reception circuit 14 are bidirectionally connected. The transmission / reception circuit 14 is also connected to a device control unit 36 ​​of the device main body 3, which will be described later.

[0026] The transducer array 11 has a plurality of ultrasound transducers arranged one-dimensionally or two-dimensionally. Each of these transducers transmits ultrasound waves in accordance with a drive signal supplied from the transmission / reception circuit 14, and receives reflected waves from the subject and outputs an analog reception signal. Each vibrator is constructed using an element in which electrodes are formed on both ends of a piezoelectric body made of, for example, a piezoelectric ceramic such as PZT (Lead Zirconate Titanate), a polymer piezoelectric element such as PVDF (Poly Vinylidene Di Fluoride), or a piezoelectric single crystal such as PMN-PT (Lead Magnesium Niobate-Lead Titanate).

[0027] The transmission / reception circuit 14, under the control of the device control unit 36, causes the transducer array 11 to transmit ultrasonic waves and generates sound ray signals by performing reception focusing processing on reception signals output from the transducer array 11 that have received ultrasonic echoes. As shown in Fig. 2, the transmission / reception circuit 14 has a pulser 51 connected to the transducer array 11, and an amplifier 52, an AD (Analog-to-Digital) converter 53, and a beamformer 54 that are connected in series from the transducer array 11 in this order.

[0028] The pulser 51 includes, for example, a plurality of pulse generators, and adjusts the delay amount of each drive signal and supplies it to the plurality of transducers in the transducer array 11 so that the ultrasonic waves transmitted from the plurality of transducers form an ultrasonic beam based on the transmission delay pattern selected by the device control unit 36. In this way, when a pulsed or continuous wave voltage is applied to the electrodes of the transducers in the transducer array 11, the piezoelectric material expands and contracts, and pulsed or continuous wave ultrasonic waves are generated from each transducer, and an ultrasonic beam is formed from the composite wave of these ultrasonic waves.

[0029] The transmitted ultrasonic beam is reflected by an object such as a part of the subject, and propagates toward the transducer array 11 of the ultrasonic probe 1. Each transducer constituting the transducer array 11 expands and contracts upon receiving the ultrasonic echo propagating toward the transducer array 11 in this manner, generating received signals which are electrical signals, and outputs these received signals to the amplifier unit 52.

[0030] The amplifier 52 amplifies the signals input from the respective transducers constituting the transducer array 11 and transmits the amplified signals to the AD converter 53. The AD converter 53 converts the analog signals transmitted from the amplifier 52 into digital received data and outputs the received data to the beamformer 54.

[0031] The beam former 54 performs so-called reception focusing processing by delaying and adding each piece of reception data converted by the AD conversion unit 53 according to the sound speed or sound speed distribution set based on the reception delay pattern selected by the device control unit 36. By this reception focusing processing, each piece of reception data converted by the AD conversion unit 53 is phased and added, and a sound ray signal in which the focus of the ultrasonic echo is narrowed is generated.

[0032] Next, the device main body 3 generates a two-dimensional ultrasound image of the examination location of the subject based on the sound ray signals generated by the ultrasound probe 1. Furthermore, the device main body 3 generates a three-dimensional ultrasound image of the examination location of the subject using multiple two-dimensional ultrasound images of the examination location of the subject. The device main body 3 displays the two-dimensional ultrasound image and the three-dimensional ultrasound image of the examination location of the subject. As shown in FIG. 1, the device main body 3 includes a two-dimensional image generation unit 31, an image memory 32, a three-dimensional image processing unit 35, a display control unit 33, a monitor (display unit) 34, an input device 37, and a device control unit 36.

[0033] The two-dimensional image generating unit 31 is connected to the transmitting / receiving circuit 14, and a display control unit 33 and a monitor 34 are sequentially connected in series to the two-dimensional image generating unit 31. An image memory 32 is connected to the two-dimensional image generating unit 31, and a display control unit 33 and a three-dimensional image processing unit 35 are respectively connected to the image memory 32. The display control unit 33 is further connected to the three-dimensional image processing unit 35. A device control unit 36 ​​is connected to the two-dimensional image generating unit 31, the display control unit 33, the image memory 32, and the three-dimensional image processing unit 35, and an input device 37 is connected to the device control unit 36.

[0034] Under the control of the device control unit 36, the two-dimensional image generation unit 31 generates a two-dimensional ultrasound image (two-dimensional ultrasound image signal) of the examination point of the subject from the received signals obtained by transmitting and receiving ultrasound beams to and from the examination point of the subject using the transducer array 11 of the ultrasound probe 1 while the ultrasound probe 1 is in contact with the examination point of the subject, and further from the sound ray signals generated from the received signals by the transmission and reception circuit 14. Furthermore, when the ultrasound probe 1 is fixed in contact with the examination location of the subject, i.e., in a stationary state, as shown in FIGS. 7A and 7B, the 2D image generation unit 31 generates multiple 2D ultrasound images, each with a different scanning plane angle or position, from received signals obtained by sequentially transmitting and receiving ultrasound beams using the transducer array 11 while shifting the angle or position of the scanning plane in the elevation direction. These multiple 2D ultrasound images are grouped together, and a single 3D ultrasound image (3D ultrasound image signal) is generated using this group of multiple 2D ultrasound images. Here, the angle of the scanning plane refers to the inclination of the scanning plane with respect to the vertical direction. Shifting the angle of the scanning plane in the elevation direction refers to increasing the inclination of the scanning plane with respect to the vertical direction in the elevation direction. As shown in FIG. 3, the two-dimensional image generating unit 31 has a configuration in which a signal processing unit 16, a DSC (Digital Scan Converter) 18, and an image processing unit 17 are connected in series.

[0035] The signal processing unit 16 generates image information data corresponding to a two-dimensional ultrasound image based on the sound ray signals generated by the transmitting / receiving circuit 14. More specifically, the signal processing unit 16 performs signal processing on the sound ray signals generated by the beamformer 54 of the transmitting / receiving circuit 14, and then performs, for example, correction for attenuation caused by the propagation distance in accordance with the depth of the position where the ultrasound is reflected, and then performs envelope detection processing to generate image information data representing tomographic image information regarding tissue in the subject.

[0036] The DSC 18 raster-converts the image information data generated by the signal processing unit 16 into an image signal that conforms to the scanning method of a normal television signal.

[0037] The image processing unit 17 performs various image processing on the image signal input from the DSC 18, such as brightness correction, tone correction, sharpness correction, image size correction, refresh rate correction, scanning frequency correction, and color correction in accordance with the display format of the monitor 34, to generate a two-dimensional ultrasound image, and outputs the processed two-dimensional ultrasound image to the image memory 32 and the display control unit 33.

[0038] The image memory 32 is a memory that stores a series of multiple frames of two-dimensional ultrasound images generated for each examination by the two-dimensional image generating unit 31 under the control of the device control unit 36. For example, when a three-dimensional ultrasound image is generated, as described above, the two-dimensional image generating unit 31 generates multiple two-dimensional ultrasound images each having a different angle or position of the scanning plane, and these multiple two-dimensional ultrasound images are stored in the image memory 32. The image memory 32 may be a recording medium such as a flash memory, HDD (Hard Disk Drive), SSD (Solid State Drive), FD (Flexible Disc), MO disk (Magneto-Optical disc), MT (Magnetic Tape), RAM (Random Access Memory), CD (Compact Disc), DVD (Digital Versatile Disc), SD card (Secure Digital card), USB memory (Universal Serial Bus memory), or an external server.

[0039] The three-dimensional image processing unit 35 performs various processes for generating a three-dimensional ultrasound image of the examination area of ​​the subject, using the multiple two-dimensional ultrasound images stored in the image memory 32, under the control of the device control unit 36. As shown in FIG. 4, the three-dimensional image processing unit 35 has a movement determination unit 42 and a three-dimensional image generation unit 43. The motion determination unit 42 and the three-dimensional image generation unit 43 are each connected to the image memory 32. The motion determination unit 42 is connected to the three-dimensional image generation unit 43, and the three-dimensional image generation unit 43 is connected to the display control unit 33.

[0040] The movement determination unit 42 sequentially calculates the similarity between at least two of the multiple two-dimensional ultrasound images stored in the image memory 32, and sequentially determines whether the movement of the ultrasound probe 1 is within a predetermined reference value based on the similarity. The method for calculating the similarity and the method for determining the movement are not particularly limited, and various conventionally known methods can be used. The movement determination unit 42, for example, calculates a similarity score and a movement score, and determines whether the movement of the ultrasound probe 1 is within a reference value depending on whether the similarity is equal to or greater than a predetermined threshold. If the similarity is equal to or greater than the threshold, i.e., if the similarity is high, the movement determination unit 42 determines that the movement of the ultrasound probe 1 is within the reference value, i.e., that the ultrasound probe 1 has not been moved by the user (examiner) of the ultrasound diagnostic device.

[0041] The motion determination unit 42 calculates, for example, a score of the degree of similarity between adjacent frames of a set of multiple 2D ultrasound images used to generate one 3D ultrasound image. When multiple 2D ultrasound images are generated by transmitting and receiving ultrasound beams while shifting the angle or position of the scan plane in the elevation direction, as in the ultrasound diagnostic device of this embodiment, the degree of similarity between adjacent frames of the 2D ultrasound images is high and always has approximately the same score. However, it is expected that the similarity will decrease significantly if the user moves the ultrasonic probe 1. Therefore, by observing the change in the similarity, it is possible to accurately determine whether the ultrasonic probe 1 has been moved by the user.

[0042] In the case of a conventional ultrasound probe having a two-dimensional transducer array, for example, ultrasound beams are transmitted and received only in the vertical direction to generate two-dimensional ultrasound images sequentially, and movement between frames of the two-dimensional ultrasound images is detected. In contrast, when generating a 3D ultrasound image, the ultrasound probe 1 of this embodiment sequentially transmits and receives ultrasound beams while shifting the angle or position of the scanning plane in the elevation direction. Therefore, the time interval between frames of 2D ultrasound images with the same scanning plane angle or position, for example, 2D ultrasound images with a vertical scanning plane, becomes long, and therefore, movement cannot be accurately detected using a method of calculating the similarity between frames of 2D ultrasound images with a vertical scanning plane, as in the prior art.

[0043] The three-dimensional image generation unit 43 extracts, from the multiple two-dimensional ultrasound images stored in the image memory 32, those two-dimensional ultrasound images for which the movement of the ultrasound probe 1 has been determined by the movement determination unit 42 to be within a reference value, and generates a three-dimensional ultrasound image. The method for generating a three-dimensional ultrasound image is not particularly limited, and various conventionally known methods for generating a three-dimensional ultrasound image from two or more two-dimensional ultrasound images can be used.

[0044] The display control unit 33 displays various types of information on the monitor 34 under the control of the device control unit 36. For example, the display control unit 33 performs predetermined processing on the two-dimensional ultrasound image generated by the two-dimensional image generation unit 31 or the two-dimensional ultrasound image stored in the image memory 32, and displays the processed two-dimensional ultrasound image on the monitor 34. The display control unit 33 also performs predetermined processing on the three-dimensional ultrasound image generated by the three-dimensional image generation unit 43, and displays the processed three-dimensional ultrasound image on the monitor 34.

[0045] The monitor 34 displays various types of information under the control of the display control unit 33. The monitor 34 displays, for example, two-dimensional ultrasound images generated by the two-dimensional image generation unit 31 or two-dimensional ultrasound images stored in the image memory 32, and three-dimensional ultrasound images generated by the three-dimensional image generation unit 43. Examples of the monitor 34 include an LCD (Liquid Crystal Display) and an organic EL (Electro-Luminescence) display.

[0046] The input device 37 receives various instructions input by the user. The input device 37 is not particularly limited, but includes various buttons and a touch panel on which the user performs a touch operation to input various instructions.

[0047] The device control unit 36 ​​controls each part of the ultrasonic probe 1 and the device main body 3 based on a pre-stored program and user instructions input from the input device 37, etc.

[0048] The two-dimensional image generating unit 31, the three-dimensional image processing unit 35, the display control unit 33, and the device control unit 36 ​​are configured by a processor 39.

[0049] Next, the operation of the ultrasonic diagnostic apparatus when generating a two-dimensional ultrasonic image will be described with reference to the flowchart of FIG.

[0050] When generating a two-dimensional ultrasound image, first, under the control of the device control unit 36, the transmission / reception circuit 14 starts transmitting ultrasound waves while the ultrasound probe 1 is in contact with the examination area of ​​the subject, and a sound ray signal is generated (step S1).

[0051] That is, in accordance with the drive signal from the pulser 51, ultrasonic beams are transmitted from the plurality of transducers of the transducer array 11 to the examination location of the subject. The ultrasonic echo from the inspection point based on the ultrasonic beam transmitted from the pulser 51 is received by each transducer of the transducer array 11, and a received signal, which is an analog signal, is output from each transducer of the transducer array 11 that receives the ultrasonic echo. The received signal output from each transducer of the transducer array 11 is amplified by the amplifier 52 and AD converted by the AD converter 53 to obtain received data. The beamformer 54 performs reception focus processing on this reception data, thereby generating sound ray signals.

[0052] Next, under the control of the device control unit 36, the two-dimensional image generation unit 31 generates a two-dimensional ultrasound image of the examination point of the subject based on the sound ray signals generated by the beamformer 54 of the transmission / reception circuit 14 (step S2).

[0053] That is, the sound ray signals generated by the beam former 54 are subjected to various signal processing by the signal processing unit 16, and image information data representing tomographic image information relating to tissues within the subject is generated. The image information data generated by the signal processing unit 16 is raster converted by the DSC 18, and then subjected to various image processing by the image processing unit 17, thereby generating a two-dimensional ultrasound image. The two-dimensional ultrasound image generated by the image processing unit 17 is stored in the image memory 32.

[0054] Next, under the control of the device control unit 36, the display control unit 33 performs predetermined processing on the two-dimensional ultrasound image generated by the image processing unit 17 or the two-dimensional ultrasound image stored in the image memory 32, and displays it on the monitor 34 (step S3).

[0055] Next, the operation of the ultrasonic diagnostic apparatus when generating a three-dimensional ultrasonic image will be described with reference to the flowchart shown in FIG.

[0056] When generating a three-dimensional ultrasound image, first, under the control of the device control unit 36, the two-dimensional image generation unit 31 generates multiple two-dimensional ultrasound images, each with a different angle or position of the scanning plane, from received signals obtained by sequentially transmitting and receiving ultrasound beams using the transducer array 11 while shifting the angle or position of the scanning plane, with the ultrasound probe 1 in contact with and fixed to the examination point of the subject (step S11).

[0057] For example, when the angle of the scanning plane is shifted using the one-dimensional transducer array 11, inside the housing of the ultrasonic probe 1, the one-dimensional transducer array 11 is mechanically moved sequentially in the elevation direction along an arc centered on the rotation axis by a predetermined angle, and ultrasonic beams are transmitted and received sequentially while the angle of the scanning plane is sequentially shifted in the elevation direction (see, for example, FIG. 2 of Patent Document 3). This generates multiple two-dimensional ultrasonic images, each with a different scanning plane angle.

[0058] When the position of the scanning plane is shifted using the one-dimensional transducer array 11, the one-dimensional transducer array 11 is mechanically translated in the elevation direction by a predetermined distance inside the housing of the ultrasonic probe 1, and ultrasonic beams are transmitted and received sequentially while the position of the scanning plane is sequentially shifted in the elevation direction (see, for example, FIG. 7B). This generates multiple two-dimensional ultrasonic images, each with a different scanning plane position.

[0059] When the angle of the scanning plane is shifted using the two-dimensional transducer array 11, data from a group of transducers extending in the azimuth direction of the two-dimensional transducer array 11 is delayed in the elevation direction, the scanning plane is sequentially steered by a predetermined angle, and ultrasonic beams are sequentially transmitted and received while the angle of the scanning plane is sequentially shifted in the elevation direction (see, for example, FIG. 7A). This generates multiple two-dimensional ultrasound images, each with a different scanning plane angle.

[0060] When the position of the scanning plane is shifted using the two-dimensional transducer array 11, a group of transducers extending in the azimuth direction of the two-dimensional transducer array 11 are sequentially selected in the elevation direction, and ultrasonic beams are sequentially transmitted and received while the position of the scanning plane is sequentially shifted in the elevation direction, thereby generating multiple two-dimensional ultrasound images each with a different scanning plane position. The method for shifting the angle or position of the scanning plane is not limited to the above specific example, and various methods can be used to shift the angle or position of the scanning plane when the ultrasonic probe 1 is in contact with and fixed to the examination point of the subject.

[0061] Subsequently, the two-dimensional ultrasound images generated by the two-dimensional image generating unit 31 are sequentially stored in the image memory 32 under the control of the device control unit 36. As a result, the image memory 32 stores a plurality of two-dimensional ultrasound images, each having a different angle or position of the scanning plane.

[0062] Next, in the three-dimensional image processing unit 35, under the control of the device control unit 36, various processes are performed using the multiple two-dimensional ultrasound images stored in the image memory 32 to generate a three-dimensional ultrasound image of the examination area of ​​the subject.

[0063] That is, the movement determination unit 42 sequentially calculates the similarity between at least two of the multiple two-dimensional ultrasound images, and sequentially determines whether the movement of the ultrasound probe 1 is within a reference value based on this similarity (step S12). Then, the three-dimensional image generating unit 43 extracts from the plurality of two-dimensional ultrasound images those two-dimensional ultrasound images for which the movement of the ultrasound probe 1 has been determined by the movement determining unit 42 to be within a reference value, and generates a three-dimensional ultrasound image (step S13).

[0064] Next, under the control of the device control unit 36, the display control unit 33 performs predetermined processing on the three-dimensional ultrasound image generated by the three-dimensional image generation unit 43, and the processed three-dimensional ultrasound image (still image) is displayed on the monitor 34 (step S14).

[0065] Thereafter, similarly, a next set of two-dimensional ultrasound images, each having a different angle or position of the scanning plane, is generated, and the next set of two-dimensional ultrasound images is used to generate a next three-dimensional ultrasound image, which is then displayed on the monitor 34. In this way, a moving image of the three-dimensional ultrasound image is displayed on the monitor 34.

[0066] In the ultrasound diagnostic device of this embodiment, the similarity between frames of two-dimensional ultrasound images is calculated, and whether or not the movement of the ultrasound probe 1 is within a reference value is determined according to this similarity, and a three-dimensional ultrasound image is generated by extracting two-dimensional ultrasound images for which it has been determined that the movement of the ultrasound probe 1 is within the reference value. As a result, even if the ultrasound probe 1 is moved by the user, an accurate three-dimensional ultrasound image can be generated by extracting two-dimensional ultrasound images for which it has been determined that the movement of the ultrasound probe 1 is within the reference value.

[0067] In addition, the three-dimensional image generating unit 43 may not generate the current three-dimensional ultrasound image when it is determined that the movement of the ultrasound probe 1 exceeds a reference value in the current set of multiple two-dimensional ultrasound images. When the current 3D ultrasound image is not generated by the 3D image generating unit 43, the display control unit 33 may display the previous 3D ultrasound image immediately before the current 3D ultrasound image on the monitor 34. In this case, the display of the 3D ultrasound image is not updated, but the 3D ultrasound image can be displayed without interruption.

[0068] Furthermore, as shown in FIG. 8, a notification unit 44 may be provided in the three-dimensional image processing unit 35B, and if a current three-dimensional ultrasound image is not generated, the notification unit 44 may notify the user of a message indicating that the display of the three-dimensional ultrasound image has not been updated. In FIG. 8, the notification unit 44 is connected to the three-dimensional image generation unit 43, and the notification unit 44 is connected to the display control unit 33. When the display control unit 33 displays the previous 3D ultrasound image on the monitor 34, the display control unit 33 may, under the control of the notification unit, display a message such as "The user has moved the probe, so an accurate 3D ultrasound image may not be displayed," on the monitor 34. This allows the user to know that an accurate 3D ultrasound image may not be displayed.

[0069] As for the method of notifying the user of the message, as described above, the message may be displayed on the monitor 34 under the control of the notification unit, or the message may be read aloud from a speaker (not shown), or both may be done simultaneously.

[0070] Alternatively, when it is determined that the movement of the ultrasound probe 1 has exceeded the reference value, the three-dimensional image generating unit 43 may extract, from among the multiple two-dimensional ultrasound images generated from multiple scanning planes, two-dimensional ultrasound images determined to have no movement up to the point in time when it was determined that there was movement, to generate a partial three-dimensional ultrasound image, as shown in Fig. 9. In other words, a partial three-dimensional ultrasound image may be generated by extracting two-dimensional ultrasound images up to the point in time when it was determined that the movement of the ultrasound probe 1 has exceeded the reference value, i.e., two-dimensional ultrasound images determined that the movement of the ultrasound probe 1 is within the reference value. In this case, the display control unit 33 displays this partial three-dimensional ultrasound image on the monitor 34. This allows the three-dimensional ultrasound image to be displayed without interruption, although it is not a complete three-dimensional ultrasound image.

[0071] Furthermore, the method of determining the similarity, in other words, the method of determining the movement of the ultrasound probe 1, may be changed depending on the object of observation present in the two-dimensional ultrasound image, for example, organs and tissues such as the heart and blood vessels.

[0072] That is, as shown in FIG. 10, an observation object specifying unit 41 is provided in the three-dimensional image processing unit 35C, and this observation object specifying unit 41 specifies an observation object present in each of the plurality of two-dimensional ultrasound images based on each of the plurality of two-dimensional ultrasound images held in the image memory 32. In FIG. 10, an observation object specifying section 41 is connected to the image memory 32, and a movement determining section 42 is connected to the observation object specifying section 41. The method for identifying the object of observation is not particularly limited, but various conventionally known methods for identifying the object of observation from a two-dimensional ultrasound image can be used, such as a method using a determination model generated by machine learning or a method using template matching. The movement determining unit 42 may change the threshold value of the similarity depending on the observation object identified by the observation object identifying unit. For example, the movement determining unit 42 changes the threshold value of the similarity when at least two 2D ultrasound images used to calculate the similarity include a 2D ultrasound image in which a specified observation object such as a heart and blood vessels is present.

[0073] For example, when imaging the heart using an ultrasound diagnostic device, the pulsation of the heart may reduce the similarity between frames of two-dimensional ultrasound images even if the ultrasound probe 1 is not moved by the user. Accordingly, as shown in Fig. 11, the heart present in each of a plurality of two-dimensional ultrasound images is identified, and if at least two of the two-dimensional ultrasound images used to calculate the similarity include a two-dimensional ultrasound image in which the heart is present, the threshold for calculating the similarity is lowered. This allows the similarity to be calculated taking into account the influence of the pulsation of the heart.

[0074] Similarly, when imaging an object with a complex structure such as a kidney, the similarity between frames of a 2D ultrasound image may be low even when the ultrasound probe 1 is not being moved by the user. In response to this, the threshold value for identifying a kidney from a 2D ultrasound image and calculating the similarity when a kidney is present is lowered. This reduces the risk of the similarity decreasing even when the ultrasound probe 1 is stationary, resulting in a false determination that the ultrasound probe 1 is moving.

[0075] Furthermore, because the structures surrounding the heart may also fluctuate due to the beating of the heart, the range of frames of the 2D ultrasound image in which the similarity threshold is changed may be expanded for frames of the 2D ultrasound image in which the heart is present. That is, when at least two two-dimensional ultrasound images used to calculate the similarity include a two-dimensional ultrasound image in which a specified object of observation is present, the movement determination unit 42 may change the similarity threshold for the two-dimensional ultrasound image in which the specified object of observation is present and a specified number of two-dimensional ultrasound images before and after it.

[0076] Specifically, when the observation object specifying unit 41 determines that a specified observation object exists, the similarity threshold is changed, for example, for two-dimensional ultrasound images of the observation object and five frames before and after it. As shown in FIG. 7B, when ultrasonic beams are transmitted and received using the transducer array 11 while shifting the position of the scanning plane in the elevation direction, the similarity threshold is lowered, for example, for two-dimensional ultrasound images of the observation object and a number of frames equivalent to 1 cm before and after it. Also, as shown in FIG. 9, when ultrasonic beams are transmitted and received using the transducer array 11 while shifting the angle of the scanning plane, the similarity threshold is lowered, for example, for two-dimensional ultrasound images of the observation object and 10° before and after it.

[0077] In the ultrasound diagnostic device, the amount of change in angle or position of adjacent scan planes is set as a parameter when generating multiple 2D ultrasound images used to generate a 3D ultrasound image. Therefore, the movement determination unit 42 acquires this parameter and can calculate the angle or distance in front of or behind the object of observation based on this parameter when changing the similarity threshold.

[0078] For example, when imaging blood vessels using an ultrasound diagnostic device, the threshold value of similarity may be changed depending on the imaging direction of the blood vessels. In this case, when imaging a short-axis image of the blood vessel, the threshold value of similarity is not changed because there is little change in the 2D ultrasound image between frames, but when imaging a long-axis image of the blood vessel, the threshold value of similarity is lowered because the 2D ultrasound image changes between frames.

[0079] Furthermore, if the area of ​​the object of observation is small, even if the object of observation changes between frames of the 2D ultrasound image, the effect on the similarity of the entire 2D ultrasound image is small. Therefore, the threshold value of the similarity may be changed depending on the area of ​​the object of observation relative to the area of ​​the entire 2D ultrasound image. For example, if the area of ​​the object of observation relative to the area of ​​the entire 2D ultrasound image is equal to or less than a predetermined threshold, the threshold value of the similarity is lowered.

[0080] In this way, it is desirable that the movement determining section 42 change the threshold value depending on at least one of the type of observation object such as the heart and blood vessels, the rendering direction of the observation object, and the area of ​​the observation object.

[0081] Alternatively, the motion determination unit 42 stores past similarities of two-dimensional ultrasound images for a predetermined number of frames, for example, the past 20 frames, or the number of frames for the past second calculated from the frame rate. Furthermore, the motion determination unit 42 calculates a similarity reference value based on the past similarities, such as the average or median of the past similarities, or the highest ranking value of the past similarities, and compares the current similarity with the similarity reference value. Here, it may be determined that the ultrasound probe 1 has moved if the current similarity falls below a predetermined threshold value relative to the similarity reference value. Specifically, if a perfect match between the similarity reference value and the current similarity is defined as 100%, the motion determination unit 42 may determine that the movement of the ultrasound probe 1 has exceeded the reference value, i.e., that the ultrasound probe 1 has moved, when the current similarity falls below a predetermined percentage, such as 80%, of the similarity reference value. In other words, it may be determined that the ultrasound probe 1 has moved when the current similarity is compared with the similarity reference value and falls outside a predetermined threshold range.

[0082] Furthermore, the movement determination unit 42 stores the similarity reference value at the timing when it is determined that the ultrasonic probe 1 has moved as the similarity in a stationary state. Furthermore, the movement determination unit 42 may determine that the ultrasonic probe 1 has again stopped moving if the current similarity falls within a predetermined threshold value with respect to the stored similarity reference value during a period when it is determined that the movement of the ultrasonic probe 1 is within the reference value, i.e., during a period when it is determined that the ultrasonic probe 1 has not moved. Specifically, if a perfect match between the previously stored similarity in a stationary state and the current similarity is defined as 100%, it may be determined that the ultrasonic probe 1 has again stopped moving if the current similarity falls within a predetermined threshold value, for example. In other words, even if it has once been determined that the ultrasonic probe 1 has moved, it may be determined that the ultrasonic probe 1 has again stopped moving if the current similarity falls within a predetermined threshold value when compared with the similarity reference value (similarity in a stationary state) stored at that timing.

[0083] When generating multiple two-dimensional ultrasound images while shifting the angle or position of the scanning plane, if the amount of change in the angle or position of the scanning plane is extremely small, in other words, if the time interval between acquisition of each frame of multiple two-dimensional ultrasound images is extremely short, even if the ultrasound probe 1 is moved by the user, there will be almost no difference between the two-dimensional ultrasound images of adjacent frames, and the similarity will likely be high.

[0084] Therefore, the motion determination unit 42 may change the frame interval of at least two two-dimensional ultrasound images used to calculate the similarity depending on the amount of change in the angle or position of the scan plane or the temporal acquisition interval of each frame of the plurality of two-dimensional ultrasound images, in other words, the frame rate when the plurality of two-dimensional ultrasound images are generated. That is, the frame interval is changed to be longer as the frame rate increases.

[0085] For example, in the first mode, the parameters are set so that the steering angle is changed in 31 steps from +15 degrees to -15 degrees in 1-degree increments, and in the second mode, the parameters are set so that the steering angle is changed in 61 steps from +15 degrees to -15 degrees in 0.5-degree increments. Thus, in the second mode, the amount of change in the angle or position of the scanning plane is very small. Therefore, in the second mode, instead of calculating the similarity of consecutive frames, it is also possible to thin out some frames from the consecutive multiple frames and calculate the similarity using the remaining frames. For example, instead of calculating the similarity between consecutive frames, such as calculating the similarity between two-dimensional ultrasound images of frame n / n+1, then calculating the similarity between two-dimensional ultrasound images of frame n+1 / n+2, etc., the similarity between two-dimensional ultrasound images of frame n / n+3 is calculated, then the similarity between two-dimensional ultrasound images of frame n+4 / n+7 is calculated, etc., by thinning out the consecutive frames and using the remaining two frames to calculate the similarity.

[0086] Furthermore, the movement determining unit 42 may calculate the similarity while thinning out a predetermined number of two-dimensional ultrasound images at a predetermined frame interval from the plurality of two-dimensional ultrasound images. For example, the similarity between the two-dimensional ultrasound images of the n / n+1 frames is calculated, the n+2 frame two-dimensional ultrasound image is skipped, and the similarity between the two-dimensional ultrasound images of the n+3 / n+4 frames is calculated, the n+5 frame two-dimensional ultrasound image is skipped, and the similarity between the n+6 / n+7 frame two-dimensional ultrasound image is calculated, etc. In this way, the similarity is calculated while thinning out some of the multiple two-dimensional ultrasound images. This reduces the calculation load compared to when calculating the similarity between the two-dimensional ultrasound images of all frames.

[0087] Additionally, the movement of the ultrasound probe 1 may be detected using a movement sensor. 12, the motion sensor 15 detects the motion of the ultrasonic probe 1 under the control of the device control unit 36 ​​and outputs a detection signal, and is attached to the ultrasonic probe 1. The device control unit 36 ​​of the device main body 3 is also connected to the motion sensor 15. The detection signals of the motion sensor 15 include detection signals of the position (amount of movement) in the movement direction, such as when the ultrasonic probe 1 is moved parallel to the epidermis of the subject, and detection signals of the angle, such as when the ultrasonic probe 1 is tilted. In this case, the movement determining unit 42 determines whether the movement of the ultrasonic probe 1 is within a reference value based on the similarity and the detection signal of the movement of the ultrasonic probe 1 output from the movement sensor 15.

[0088] The method for detecting the movement is not particularly limited, and various conventionally known methods can be used. The movement of the ultrasonic probe 1 includes a change in the position (amount of movement) of the ultrasonic probe 1 in the movement direction, a change in the angle of the ultrasonic probe 1, and the like. For example, by using an acceleration sensor as the motion sensor 15, it is possible to detect changes in the angle of the ultrasonic probe 1. On the other hand, it is difficult to detect changes in the position of the ultrasonic probe 1 in the direction of movement using an acceleration sensor. In contrast, by using a magnetic sensor as the motion sensor 15, in the three-dimensional space of the magnetic field generated by the magnetic field generator, a magnetic field position detector can detect the position of the magnetic sensor, i.e., the position of the ultrasonic probe 1 in the movement direction, and the angle of the ultrasonic probe 1 relative to the vertical direction (the tilt of the ultrasonic probe 1 relative to the vertical direction) based on the position detection signal and angle detection signal output from the magnetic sensor.

[0089] The movement determination unit 42 may determine the movement of the ultrasonic probe 1 based only on the similarity, or may determine the movement of the ultrasonic probe 1 based only on the detection signal of the motion sensor, or may determine the movement of the ultrasonic probe 1 using both.

[0090] The movement determining unit 42 can, for example, score the similarity and the detection signal of the movement sensor, and determine whether the ultrasonic probe 1 is moving or not based on the total value of the scores.

[0091] Fig. 13A is a graph of an embodiment of a conversion table representing scores for similarity, Fig. 13B is a graph of an embodiment of a conversion table representing scores for detection signals of the amount of movement by the motion sensor 15, and Fig. 13C is a graph of an embodiment of a conversion table representing scores for detection signals of the angle by the motion sensor 15. The horizontal axes of the graphs shown in Fig. 13A, Fig. 13B, and Fig. 13C represent similarity, amount of movement, and angle, respectively, and the vertical axes represent scores corresponding to similarity, amount of movement, and angle.

[0092] 13A, 13B, and 13C, the motion determination unit 42 calculates a score for the similarity, a score for the detection signal of the amount of movement by the motion sensor 15, and a score for the detection signal of the angle by the motion sensor 15, and then adds these three scores together to calculate a final total score. The motion determination unit 42 compares the total score with a predetermined threshold, and determines that the ultrasonic probe 1 is moving if the total score is equal to or greater than the threshold, and determines that the ultrasonic probe 1 is not moving if the total score is less than the threshold.

[0093] Note that the graphs of the conversion tables shown in Figures 13A, 13B, and 13C are merely examples. In the graphs of Figures 13A, 13B, and 13C, the upper limit of the score of each conversion table is set to 1.0, but each can be set to any value. For example, if emphasis is to be placed on the similarity score, the upper limit of the score of the similarity conversion table may be made higher than the upper limit of the scores of the other conversion tables, thereby weighting the scores. Furthermore, the shape of each graph is not limited to the shape of the graph shown in Figures 13A, 13B, and 13C.

[0094] Furthermore, the presence or absence of movement of the ultrasonic probe 1 may be determined based on both the similarity and the movement sensor 15, and the movement of the ultrasonic probe 1 may be finally determined by combining these determination results.

[0095] For example, when the movement of the ultrasonic probe 1 is determined based on the AND condition of the determination result based on the similarity and the determination result by the movement sensor 15, the final determination result is as follows: a. Similarity: No movement, Motion sensor: No movement → Final judgment result: No movement b. Similarity: Motion detected, Motion sensor: No motion → Final result: No motion c. Similarity: No movement, Motion sensor: Movement → Final judgment result: No movement d. Similarity: Motion detected, Motion sensor: Motion detected → Final judgment result: Motion detected In the case of the above b, the final determination result is different from the determination result based solely on the similarity.

[0096] When the object of observation is the heart, as described above, it is expected that the similarity of the two-dimensional ultrasound images between frames will decrease due to the heartbeat even if the ultrasound probe 1 is not moving. In response to this, the motion determination unit 42 determines the motion of the ultrasound probe 1 using the determination result from the motion sensor 15, thereby making it possible to correctly determine that there is no motion when the ultrasound probe 1 is stationary.

[0097] On the other hand, when the movement of the ultrasonic probe 1 is determined based on the OR condition of the determination result based on the similarity and the determination result by the movement sensor 15, the final determination result is as follows. a. Similarity: No movement, Motion sensor: No movement → Final judgment result: No movement b. Similarity: Motion detected, Motion sensor: No motion → Final result: Motion detected c. Similarity: No movement, Motion sensor: Movement detected → Final result: Movement detected d. Similarity: Motion detected, Motion sensor: Motion detected → Final judgment result: Motion detected In the case of the above c, the final determination result is different from the determination result based on the similarity alone.

[0098] 14, when the ultrasonic probe 1 is manually rotated by the user at a speed close to the change in angle that steers the transducer array 11 in the elevation direction, the angle of the scanning plane does not change much even though the ultrasonic probe 1 is moving. In this case, the similarity increases even though the ultrasonic probe 1 is moving. In contrast, when the determination result by the motion sensor 15 indicates that there is movement, the motion determination unit 42 determines that there is movement as the final determination result, thereby correctly determining the movement of the ultrasonic probe 1.

[0099] Furthermore, the total value of the similarity and the scores of the motion sensor, and the combination (AND condition, OR condition) of the determination result based on the similarity and the determination result by the motion sensor 15 may be set in advance for each test. For example, in the case of the heart, an AND condition of the determination result based on the similarity and the determination result by the motion sensor 15 is used, and in the case of the bladder, an OR condition of the determination result based on the similarity and the determination result by the motion sensor 15 is used, and in other cases, the total value of the similarity and the scores of the motion sensor 15 is used.

[0100] The present invention is not limited to stationary ultrasonic diagnostic devices, but is also applicable to portable ultrasonic diagnostic devices in which the device main body 3 is realized by a laptop-type terminal device, and handheld ultrasonic diagnostic devices in which the device main body 3 is realized by a handheld terminal device such as a smartphone or a tablet PC (Personal Computer). Furthermore, the ultrasonic probe 1 and the device main body 3 may be connected by wire or wirelessly. Furthermore, the entire two-dimensional image generating unit 31 or only the signal processing unit 16 may be provided on the ultrasonic probe 1 side, or these may be provided on the device main body 3 side.

[0101] In the device of the present invention, the hardware configuration of the processing units that perform various processes, such as the transmission / reception circuit 14, the two-dimensional image generation unit 31, the display control unit 33, the three-dimensional image processing unit 35, and the device control unit 36, may be dedicated hardware or various processors or computers that execute programs.

[0102] Various types of processors include CPUs (Central Processing Units), which are general-purpose processors that execute software (programs) and function as various processing units, programmable logic devices (PLDs), which are processors whose circuit configuration can be changed after manufacture, such as FPGAs (Field Programmable Gate Arrays), and dedicated electrical circuits, such as ASICs (Application Specific Integrated Circuits), which are processors with circuit configurations designed specifically for performing specific processes.

[0103] A single processing unit may be configured with one of these various processors, or may be configured with a combination of two or more processors of the same or different types, for example, a combination of multiple FPGAs, or a combination of an FPGA and a CPU, etc. Also, multiple processing units may be configured with one of the various processors, or two or more of the multiple processing units may be combined into one processor.

[0104] For example, as typified by server and client computers, one processor is configured by combining one or more CPUs and software, and this processor functions as multiple processing units. Another form is the use of a processor that realizes the functions of an entire system including multiple processing units on a single IC (Integrated Circuit) chip, as typified by system-on-chip (SoC).

[0105] Furthermore, the hardware configuration of these various processors is, more specifically, an electric circuit that combines circuit elements such as semiconductor elements.

[0106] The method of the present invention can be implemented by, for example, a program that causes a computer to execute each step. Also, a computer-readable recording medium on which this program is recorded can be provided.

[0107] Although the present invention has been described in detail above, the present invention is not limited to the above-described embodiments, and various improvements and modifications may be made without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0108] 1 Ultrasound probe, 3 Device body, 11 Transducer array, 14 Transmitting and receiving circuit, 15 Motion sensor, 16 Signal processing unit, 17 Image processing unit, 18 DSC, 31 Two-dimensional image generation unit, 32 Image memory, 33 Display control unit, 34 Monitor, 35, 35B, 35C Three-dimensional image processing unit, 36 Device control unit, 37 Input device, 39 Processor, 41 Observation object identification unit, 42 Motion determination unit, 43 Three-dimensional image generation unit, 44 Notification unit, 51 Pulser, 52 Amplification unit, 53 AD conversion unit, 54 Beamformer.

Claims

1. an ultrasonic probe having an array of transducers; a two-dimensional image generating unit that generates a plurality of two-dimensional ultrasound images from received signals obtained by sequentially transmitting and receiving ultrasound beams while shifting the angle or position of the scanning plane using the transducer array, while the ultrasound probe is in contact with and fixed to an examination site of the subject; a movement determination unit that sequentially calculates similarities between at least two of the plurality of two-dimensional ultrasound images and sequentially determines whether or not a movement of the ultrasound probe is within a predetermined reference value according to the similarities; a three-dimensional image generating unit that extracts, from the plurality of two-dimensional ultrasound images, two-dimensional ultrasound images in which the movement of the ultrasound probe is determined to be within the reference value, and generates a three-dimensional ultrasound image; The monitor and a display control unit that displays the three-dimensional ultrasound image on the monitor; Equipped with Ultrasound diagnostic equipment.

2. the three-dimensional image generating unit does not generate the current three-dimensional ultrasound image when it is determined that the movement of the ultrasound probe has exceeded the reference value; the display control unit, when the current three-dimensional ultrasound image is not generated, causes the monitor to display a previous three-dimensional ultrasound image immediately before the current three-dimensional ultrasound image. The ultrasonic diagnostic apparatus according to claim 1 .

3. a notification unit that notifies a user of a message indicating that the display of the three-dimensional ultrasound image has not been updated when the current three-dimensional ultrasound image has not been generated; the display control unit causes the monitor to display the message when the monitor displays the previous three-dimensional ultrasound image immediately before the current three-dimensional ultrasound image. The ultrasonic diagnostic apparatus according to claim 2 .

4. The movement determination unit determines that the movement of the ultrasound probe is within the reference value when the similarity is equal to or greater than a predetermined threshold value.

4. The ultrasonic diagnostic apparatus according to claim 1.

5. an observation object specifying unit that specifies an observation object present in each of the plurality of two-dimensional ultrasound images based on each of the plurality of two-dimensional ultrasound images, the movement determining unit changes the threshold value in accordance with the object to be observed. The ultrasonic diagnostic apparatus according to claim 4.

6. the motion determination unit changes the threshold value when the at least two two-dimensional ultrasound images include a two-dimensional ultrasound image in which a predetermined observation object is present. The ultrasonic diagnostic apparatus according to claim 5 .

7. When the at least two two-dimensional ultrasound images include a two-dimensional ultrasound image in which a predetermined observation object is present, the movement determination unit changes the threshold value for the two-dimensional ultrasound image in which the predetermined observation object is present and for a predetermined number of two-dimensional ultrasound images before and after the two-dimensional ultrasound image in which the predetermined observation object is present. The ultrasonic diagnostic apparatus according to claim 5 .

8. the movement determining unit changes the threshold value in accordance with at least one of the type of the observation object, the rendering direction of the observation object, and the area of ​​the observation object.

8. The ultrasonic diagnostic apparatus according to claim 5.

9. the motion determination unit calculates a similarity reference value based on the similarity of two-dimensional ultrasound images for a predetermined number of frames, and determines that the motion of the ultrasound probe has exceeded the reference value when the current similarity is below a predetermined threshold value with respect to the similarity reference value.

4. The ultrasonic diagnostic apparatus according to claim 1.

10. the movement determination unit stores the similarity reference value at the timing when the current similarity with respect to the similarity reference value falls below the predetermined threshold, and determines that the ultrasound probe has stopped moving when the current similarity falls within the predetermined threshold with respect to the stored similarity reference value during a period in which the movement of the ultrasound probe is determined to be within the reference value. The ultrasonic diagnostic apparatus according to claim 9.

11. the motion determination unit changes a frame interval between the at least two two-dimensional ultrasound images in accordance with a frame rate at which the plurality of two-dimensional ultrasound images are generated. The ultrasonic diagnostic apparatus according to any one of claims 1 to 10.

12. the motion determination unit calculates the similarity while thinning out a predetermined number of two-dimensional ultrasound images at a predetermined frame interval from the plurality of two-dimensional ultrasound images. The ultrasonic diagnostic apparatus according to any one of claims 1 to 11.

13. a motion sensor attached to the ultrasound probe; the movement determination unit determines whether the movement of the ultrasonic probe is within the reference value based on the similarity and a detection signal of the movement of the ultrasonic probe output from the movement sensor. The ultrasonic diagnostic apparatus according to any one of claims 1 to 12.

14. a step in which a two-dimensional image generating unit generates a plurality of two-dimensional ultrasound images from received signals obtained by sequentially transmitting and receiving ultrasound beams while shifting the angle or position of a scanning plane using an ultrasound probe having an ultrasound transducer array in a state where the ultrasound probe is in contact with and fixed to an examination location of a subject; a step in which a motion determination unit sequentially calculates similarities between at least two of the plurality of two-dimensional ultrasound images, and sequentially determines whether or not a motion of the ultrasound probe is within a predetermined reference value according to the similarities; a three-dimensional image generating unit extracting, from the plurality of two-dimensional ultrasound images, two-dimensional ultrasound images for which the movement of the ultrasound probe is determined to be within the reference value, and generating a three-dimensional ultrasound image; a step of causing a display control unit to display the three-dimensional ultrasound image on a monitor.

Images