WO2022054848A1 - Image capturing device and program - Google Patents

Abstract

Provided are an image capturing device and a program that reduce the time until all ultrasound waves emitted are received. This image capturing device has a plurality of ultrasound elements for capturing an image of a subject using ultrasound waves, and is provided with: emission opening parts that include a plurality of ultrasound elements E and emit ultrasound waves to the subject T; a plurality of reception opening parts that receive reflected waves and transmitted waves of the ultrasound waves emitted to the subject, and output the waves as reception signals; and an emission control unit that controls emission of ultrasound waves. The emission control unit causes predetermined two or more emission opening parts among the plurality of emission opening parts to emit ultrasound waves within a predetermined time.

Description

Imaging equipment and programs

This disclosure relates to an image pickup device and a program.

The non-invasive ultrasonic diagnostic system is widely used in the medical field as a technique for diagnosing information inside a subject because it does not require surgery to directly incise and observe the living body.

Ultrasound CT (Computed Tomography), which is a method of ultrasonic diagnosis, irradiates a subject with ultrasonic waves and creates a tomographic image of the subject using reflected ultrasonic waves or transmitted ultrasonic waves. Studies have shown that it is useful in detecting breast cancer. The ultrasonic CT uses, for example, a ring-type array transducer in which a large number of elements for transmitting and receiving ultrasonic waves are arranged in a ring shape to create a tomographic image.

For example, while switching the elements (openings) that transmit ultrasonic waves in order, all the elements receive the echo signal and save it as RF data (raw data). Then, an image signal representing a tomographic image is generated based on the RF data.

International Publication No. 2017/051903

By the way, in order to create an image signal, ultrasonic waves are transmitted from all openings. That is, in order to generate an image signal, it is necessary to receive ultrasonic waves transmitted from all openings. On the other hand, it is preferable if the time until all the transmitted ultrasonic waves (received signals) are received can be shortened.

The present invention has been made in view of the above-mentioned conventional circumstances, and an object of the present invention is to provide an imaging device and a program that shortens the time until all transmitted ultrasonic waves are received.

The present invention is an imaging device having a plurality of ultrasonic elements for imaging a subject using ultrasonic waves, and includes a plurality of the ultrasonic elements, and a transmission opening for transmitting ultrasonic waves toward the subject. A reception opening that receives reflected waves and transmitted waves of ultrasonic waves transmitted to the subject and outputs them as a reception signal, and a transmission control unit that controls transmission of ultrasonic waves. The unit relates to an image pickup device that transmits ultrasonic waves from two or more predetermined transmission openings among a plurality of transmission openings within a predetermined time.

Further, it is preferable that the transmission opening and the reception opening are arranged in the vicinity of the subject and on the same plane.

Further, it is preferable that the image pickup apparatus further includes an image generation unit that generates an captured image using the output received signal.

Further, it is preferable that the image generation unit separates the received ultrasonic signal into a signal for each transmission opening of the transmission source.

Further, the image generation unit separates the mask execution unit that masks the signal indicating the transmitted wave from the output received signals and the masked reception signal into signals for each transmission opening of the transmission source. It is preferable to further include a unit and a generation execution unit that executes image generation of the subject based on the separated signal.

Further, the image generation unit separates the mask execution unit that masks the signal indicating the reflected wave from the output received signals and the masked reception signal into signals for each transmission opening of the transmission source. It is preferable to further include a unit and a generation execution unit that executes image generation of the subject based on the separated signal.

Further, it is preferable that the image generation unit separates overlapping signals in four-dimensional space at an arbitrary scattering point or a specific receiving element in the imaging region by using deep learning.

Further, it is preferable that the transmission control unit transmits ultrasonic waves to the predetermined two or more transmission openings at least for a part of the time.

Further, it is preferable that the transmission control unit transmits the ultrasonic signal to the transmission opening at a time interval that does not overlap with the reception timing of the component that draws the subject among the received ultrasonic signals.

Further, it is preferable that the transmission control unit determines the transmission interval based on the positional relationship between the transmission opening and the reception opening.

Further, it is preferable that the transmission control unit sets the ultrasonic signal first transmitted from one transmission opening within the time before the reception opening receives the ultrasonic signal for the predetermined time.

Further, it is preferable that the transmission control unit is configured to be able to switch the movement interval of the ring array in the axial direction.

Further, the present invention includes a plurality of transmission openings for transmitting ultrasonic waves to a subject, and the ultrasonic waves receive reflected waves and transmitted waves in the subject and output them as reception signals. A program that causes a computer to function as an imaging device including a plurality of receiving openings, the transmission control unit that controls the transmission of ultrasonic waves, and the plurality of transmission openings within a predetermined time. The present invention relates to a program that functions as a transmission control unit that transmits ultrasonic waves from two or more predetermined transmission openings.

According to the present disclosure, it is possible to provide an imaging device and a program that shortens the time until all transmitted ultrasonic waves are received.

It is a schematic diagram of the image pickup apparatus which concerns on one Embodiment of this invention. It is a schematic diagram which shows the image pickup apparatus of one Embodiment. FIG. 2 is a cross-sectional view taken along the line II of FIG. It is a block diagram which shows the structure of the arithmetic unit of the image pickup apparatus of one Embodiment. It is a graph which shows an example when the transmitted wave is masked from the received signal by the image generation part of the image pickup apparatus of one Embodiment. It is a schematic diagram which shows the example which separates a signal by the image generation part of the image pickup apparatus of one Embodiment. It is a screen view which shows the image imaged by the image pickup apparatus of one Embodiment. It is a free chart which shows the flow of operation of the image pickup apparatus which concerns on one Embodiment. It is a graph which shows the result of the simulation experiment for determining the numerical aperture of the image pickup apparatus which concerns on a modification.

Hereinafter, the image pickup apparatus 1 and the program according to each embodiment of the present invention will be described with reference to FIGS. 1 to 8.
The image pickup device 1 is a device that takes an image of a subject using ultrasonic waves. The image pickup apparatus 1 generates a tomographic image (ultrasonic image) of a subject by using, for example, ultrasonic waves. The image pickup apparatus 1 transmits ultrasonic waves to a subject such as a human body. The image pickup apparatus 1 generates a tomographic image using the reflected wave reflected by the subject. As shown in FIGS. 1 and 2, the image pickup apparatus 1 includes a ring array R, a transmission opening 10, a reception opening 20, a switch circuit 110, a transmission / reception circuit 120, an arithmetic unit 130, and an image display device. 140 and.

The ring array R is configured by combining a plurality of oscillators. The ring array R is preferably configured by combining ring-shaped oscillators having a diameter of 80 to 500 mm, more preferably a diameter of 100 to 300 mm. In the present embodiment, as an example, the ring array R is configured by using a ring-shaped oscillator in which four concave oscillators P01 to P04 are combined.

For example, when the concave oscillators P01 to P04 each have 512 strip-shaped piezoelectric elements E (hereinafter, also simply referred to as “elements E”), the ring array R is composed of 2048 elements E. become. The number of elements E provided in the concave oscillators P01 to P04 is not limited, and is preferably 1 to 1000.

Each element E has a function of mutually converting an electric signal and an ultrasonic signal. The element E transmits ultrasonic waves to the subject T. Further, the element E receives the reflected wave reflected by the subject T and the transmitted wave transmitted through the subject T. The element E outputs the received reflected wave and transmitted wave as a received signal. In the present embodiment, each element E is described as having both functions of transmitting and receiving ultrasonic waves.

The ring array R is arranged on the upper surface of the bed with a hole, for example, as shown in FIG. The ring array R has an insertion portion SP for inserting the sample T. The insertion portion SP is provided at the center position of the ring array R in a plan view. The ring array R is installed so that the hole in the bed and the insertion portion SP overlap each other. As a result, as shown in FIG. 3, the subject inserts the body part (subject T) to be imaged into the insertion portion SP through the hole in the bed. The plurality of elements E of the ring array R are arranged along the ring around the insertion portion SP at equal intervals. On the inner peripheral side of the ring array R, a convex lens called an acoustic lens is attached to the surface.

The transmission opening 10 includes a plurality of elements E and transmits ultrasonic waves toward the subject T. The transmission opening 10 includes, for example, a plurality of elements E among the elements E of the ring array R as a group.

Similar to the transmission opening 10, the reception opening 20 includes a plurality of adjacent elements E as a group. The reception opening 20 receives the transmitted wave transmitted through the subject T and the reflected wave reflected by the subject T with respect to the transmitted ultrasonic wave by using the plurality of adjacent elements E. In the present embodiment, the reception opening 20 is used in common with the element E included in the transmission opening 10. That is, the reception opening 20 is composed of the element E that operates as the transmission opening 10.

The switch circuit 110 is a circuit for switching the transmission opening 10 for transmitting ultrasonic waves. The switch circuit 10 is connected to each of the plurality of elements E of the ring array R. The switch circuit 110 transmits a drive signal to a predetermined element E. As a result, the switch circuit 110 causes the predetermined element E to transmit ultrasonic waves. In the present embodiment, the switch circuit 110 sequentially switches the transmission opening 10 and the reception opening 20 in one of the circumferential directions of the ring array R. That is, the switch circuit 110 sequentially switches the elements E constituting the transmission opening 10 and the reception opening 20.

The transmission / reception circuit 120 is a circuit that instructs the transmission opening 10 of the magnitude of the ultrasonic wave to be transmitted. Further, the transmission / reception circuit 120 is a circuit that instructs the transmission opening 10 of the type of wave to be transmitted (continuous wave, pulse wave, plane wave, etc.). Further, the transmission / reception circuit 120 is a circuit that acquires the reflected wave and the transmitted wave received by the element E as a reception signal.

As shown in FIG. 4, the arithmetic unit 130 is composed of, for example, a computer including a CPU, a communication unit, a storage unit M, and the like. The storage unit M has, for example, a RAM, a ROM, a hard disk, and the like. By executing the image reconstruction program stored in the storage unit M, functions such as the data acquisition unit 136 and the image generation unit 137 are realized, and the data storage area 133 for measurement is secured in the storage unit M. The arithmetic unit includes a learning processing unit 134, a transmission control unit 135, a data acquisition unit 136, and an image generation unit 137.

The storage unit M stores the learning device 131. The learner 131 is a processing execution program for processing each parameter such as weight and bias for each unit (neuron) and input data. The fact that the learning device 131 is stored in the storage unit M means that various parameters and processing execution programs related to the learning unit M are stored in the storage unit M.

The learning processing unit 134 is realized, for example, by operating the CPU. The learning processing unit 134 executes the learning processing of the learning device 131 by using the learning data 132 stored in the storage unit M. The training data 132 simulates the sizes and arrangements of the plurality of elements E of the ring array R on the simulation space with respect to the biological model (subject model) represented by the distribution of acoustic characteristics. Further, the training data includes RF data of a simulation in which reflected ultrasonic waves from a biological model are received by a plurality of elements E while switching the transmission opening 10, and a measured image of the biological model (a biological model such as a spatial gradient intensity of acoustic impedance). (Ideal measurement image calculated from the acoustic characteristics of) and included. Multiple sets of simulation RF data and measured images are prepared.

The learning processing unit 134 inputs simulation RF data to the learning device 131. The learning execution unit trains the learning device 131 using the simulation RF data so that the output data of the learning device 131 matches the pixel value of the measured image.

The transmission control unit 135 is realized, for example, by operating the CPU. The transmission control unit 135 controls the transmission of ultrasonic waves. The transmission control unit 135 sequentially switches the elements E constituting the transmission opening 10 and the reception opening 20 by sequentially switching the transmission and reception elements E. The transmission control unit 135 uses, for example, a group of elements E at a predetermined position of the ring array R as a transmission opening 10. The transmission control unit 135 switches the transmission opening 10 to one of the circumferential directions by switching the group of elements E to one of the circumferential directions of the ring array R from a predetermined position. The transmission control unit 135 sequentially switches the transmission opening 10 until it returns to a predetermined position. As a result, the transmission opening 10 transmits ultrasonic waves from the transmission opening 10 that can be switched to the subject T, so that the subject T is imaged from the entire circumferential direction. Further, the transmission opening 10 also switches the reception opening 20 for the reception opening 20 in the same manner as the transmission opening 10. As a result, the receiving opening 20 acquires the reflected wave and the transmitted wave in the subject T from the entire circumferential direction. It is also possible to receive at the same time without switching the reception aperture. For example, the transmission control unit 135 causes ultrasonic waves to be transmitted from two or more predetermined transmission openings 10 among the plurality of transmission openings 10 within a predetermined time. The transmission control unit 135 causes, for example, two or more predetermined transmission openings 10 to transmit ultrasonic waves at least for a part of the time. In the present embodiment, the transmission control unit 135 sets the predetermined time within the time before the ultrasonic signal first transmitted from the transmission opening 10 is received by the reception opening 20.

The data collection unit 136 collects (including receiving or acquiring) measurement data (RF data), which is data obtained by a plurality of elements E, via the switch circuit 110 and the transmission / reception circuit 120120. The data collection unit 136 stores RF data in the RF data storage area 133 of the storage unit M. In the present embodiment, the data collecting unit collects a signal transmitted by the plurality of transmitting openings 10 and indicating a reflected wave and a transmitted wave of ultrasonic waves as a received signal.

The image generation unit 137 is realized, for example, by operating the CPU. The image generation unit 137 separates the output received signal into a signal for each transmission opening 10 of the transmission source and generates an image of the subject T. The image generation unit 137 includes a mask execution unit 141, a separation unit 142, and a generation execution unit 143.

The mask execution unit 141 separates the signal in the region including the transmitted wave and the region not including the transmitted wave from the output received signal. The mask execution unit 141 detects, for example, a transmitted wave component included in the received signal. The mask execution unit 141 creates a mask for removing the detected transmitted wave component. The mask execution unit 141 filters the received signal using the created mask.

As shown in FIG. 5, the mask execution unit 141 calculates the envelope of the received signal (FIG. 5 (a)) (FIG. 5 (b)). Then, the mask execution unit 141 detects the time when the signal strength becomes maximum. The mask execution unit 141 creates a mask with a predetermined width before and after the detected time (FIG. 5 (c)). The mask execution unit 141 applies the created mask to the received signal. As a result, the mask execution unit 141 obtains a signal from which the transmitted wave is removed (FIG. 5 (d)).

The separation unit 142 separates the masked reception signal into a signal for each transmission opening 10 of the transmission source. For example, as shown in FIG. 6, the separation unit 142 separates ultrasonic waves transmitted from a plurality of directions and containing a plurality of reflections from the received signal for each transmission opening 10 of the transmission source. The separation unit 142 separates the masked reception signal into a signal for each transmission opening 10 by using, for example, a learning model learned by the learning processing unit 134.

In the present embodiment, in order to separate the signal of the reflected wave image, the transmitted wave is masked and filtered, but the range of the masked signal is not limited to this. For example, for the purpose of reconstructing an attenuated image using a transmitted wave, it is possible to mask the reflected wave and emphasize the signal due to the transmitted wave for acquisition. Reflected waves include forward and side scattered waves. Therefore, the signals received by the element located at the transmission opening are forward scattered waves and transmitted waves. Since the transmission aperture and the reception aperture are on the same plane, the arrival time of the transmitted wave is determined to be the first place once the speed of sound is determined. Thereby, the mask can be set at a fixed time from the transmission. However, in the present embodiment, simultaneous transmission of ultrasonic waves from a plurality of directions causes a four-dimensional signal in time and space at a certain observation point (for example, a pixel or a scattering point in a reception aperture or an imaging region). Overlap. These signals are difficult to separate by physical algorithms. In the present invention, it is possible to separate signals that are difficult to separate by these algorithms by a deep learning method, extract different parameters such as reflected waves and transmitted waves, and measure the biological information of the subject.

The generation execution unit 143 executes image generation of the subject T based on the separated signal. The generation execution unit 143 generates an ultrasonic image using the reflected wave of the subject T, for example, as shown in FIG. 7. That is, the generation execution unit 143 generates an ultrasonic image using the reflected wave remaining after removing the transmitted wave from the received signal.

The image display device is, for example, a display device such as a display. The image display device 140 displays the ultrasonic image generated by the generation execution unit 143.

Next, the operation of the image pickup apparatus 1 will be described with reference to FIG.
First, the transmission control unit 135 determines a transmission opening 10 to be transmitted an ultrasonic signal (step S1). As shown in FIG. 7, the transmission control unit 135 determines, for example, four transmission openings 10 arranged on two orthogonal diameters. Further, the transmission control unit 135 determines the four transmission openings 10 adjacent to one of the four transmission openings 10 in the circumferential direction as the next transmission target. The transmission control unit 135 determines the transmission target until the transmission of all the transmission openings 10 is completed.

Next, the transmission / reception circuit 120 causes the transmission opening 10 to transmit ultrasonic waves based on the determined transmission target (step S2). The transmission / reception circuit 120 operates, for example, a transmission opening 10 determined as a transmission target by controlling a switch circuit. Next, the data acquisition unit receives the ultrasonic signal including the reflected wave reflected by the subject T and the transmitted wave transmitted through the subject T via the transmission / reception circuit 120 (step S3).

Next, it is determined whether or not transmission has been performed from all transmission openings 10 (step S4). When the transmission from all the transmission openings 10 is completed (step S4: YES), the process proceeds to step S5. On the other hand, when the transmission from all the transmission openings 10 is not completed (step S4: NO), the process proceeds to step S2.

In step S5, the mask execution unit 141 removes transmitted waves from the received received signal. Next, the separation unit 142 separates the signal for each transmission opening 10 of the transmission source (step S6). Next, the generation execution unit 143 generates an ultrasonic image (step S7). This ends this flow.

Next, the program will be described.
Each configuration included in the image pickup apparatus 1 can be realized by hardware, software, or a combination thereof. Here, what is realized by software means that it is realized by a computer reading and executing a program.

The program is stored using various types of non-transitory computer readable medium and can be supplied to the computer. Non-temporary computer-readable media include various types of tangible storage mediums. Examples of non-temporary computer-readable media include magnetic recording media (eg, flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (eg, magneto-optical disks), CD-ROMs (Read Only Memory), CD-. Includes R, CD-R / W, semiconductor memory (eg, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (random access memory)). The display program may also be supplied to the computer by various types of transient computer readable medium. Examples of temporary computer readable media include electrical, optical, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

Next, an embodiment of the image pickup apparatus 1 according to the present embodiment will be described.
The number of elements E in one transmission opening 10 and reception opening 20 is defined as eight for the 2048 elements E included in the ring array R. The number of transmission aperture elements may be more 256 elements or the like as long as the transmission waveform is a plane wave. Then, the ultrasonic signal is transmitted at the time when the four transmission openings 10 overlap. The positions of the four transmission openings 10 were the transmission openings 10 arranged on the two orthogonal diameters of the ring array R. That is, the pair of transmission openings 10 that oppose each other and the pair of transmission openings 10 that are arranged at positions offset by 90 degrees in the circumferential direction transmit ultrasonic signals. Then, by sequentially changing the transmission openings 10 for transmitting ultrasonic waves in one of the circumferential directions, ultrasonic signals were transmitted from all the transmission openings 10. At this time, both the transmission opening 10 and the reception opening 20 adjacent to each other may be set so that the plurality of elements E overlap. Here, the time required to acquire one slice and the data size to be acquired are the products of the number of transmissions and the number of all transmission openings 10. Therefore, by transmitting from all the transmission openings 10, the time from the start to the end of imaging can be reduced to about 1/4 as compared with the conventional case. Further, the data capacity of the RAW data, which is the received signal of the entire captured image, can be reduced to 1/4 as compared with the conventional case.

As described above, according to the image pickup apparatus 1 and the program according to the present embodiment, the following effects are obtained.
(1) An image pickup apparatus 1 having a plurality of elements E for imaging a subject T using ultrasonic waves, including a plurality of elements E, and a plurality of transmission openings for transmitting ultrasonic waves to the subject T. A reception opening 20 that receives a reflected wave and a transmitted wave of ultrasonic waves transmitted to the subject T and outputs them as a reception signal, and a transmission control unit 135 that controls transmission of ultrasonic waves. The transmission control unit 135 causes ultrasonic waves to be transmitted from two or more predetermined transmission openings 10 among the plurality of transmission openings 10 within a predetermined time.
Further, a plurality of transmission openings 10 for transmitting ultrasonic waves to the subject T, and a plurality of reception openings 20 for receiving the reflected waves and transmitted waves in the subject T and outputting them as reception signals. A program that causes a computer to function as an image generation device that generates an image of a subject T by separating the received signal output from the image pickup device 1 including the above into a signal for each transmission opening 10 of the transmission source. Is a transmission control unit 135 that controls the transmission of ultrasonic waves, and is a transmission control unit 135 that transmits ultrasonic waves from two or more predetermined transmission openings 10 among a plurality of transmission openings 10 within a predetermined time. To function as.
As a result, the time from the start of imaging to the completion of imaging (imaging time) can be shortened as compared with the case where ultrasonic waves are sequentially transmitted exclusively from the transmission opening 10. Further, by reducing the number of times the transmitted ultrasonic signal is received, the total capacity of the received data can be reduced.

(2) The transmission opening 10 and the reception opening 20 are arranged in the vicinity of the subject T. Thereby, the reflected wave from the subject T can be easily acquired.

(3) The image pickup apparatus 1 further includes an image generation unit 137 that generates an image to be captured by using the output received signal. As a result, an ultrasonic image can be easily generated together with the imaging.

(4) The image generation unit 137 separates the received ultrasonic signal into signals for each transmission opening 10 of the transmission source. As a result, the signals separated for each transmission opening 10 of the transmission source can be used for image generation, so that the accuracy of the generated image can be improved as compared with the case where the signals are not separated.

(5) The image generation unit 137 separates the masked reception signal into a mask execution unit 141 that masks a signal indicating a transmitted wave and a signal for each transmission opening of the transmission source among the output received signals. Further includes a separation unit 142 to perform image generation, and a generation execution unit 143 to execute image generation of the subject based on the separated signal. This makes it possible to generate an ultrasonic image with high accuracy using only the reflected wave. Further, since the received signal can be separated even if the signal is not frequency-separated and time-separated, the versatility of image generation can be improved.

(6) The image generation unit 137 separates the masked reception signal into a signal for each transmission opening 10 of the transmission source, and a mask execution unit 141 that masks the signal indicating the reflected wave among the output reception signals. Further includes a separation unit 142 and a generation execution unit 143 that executes image generation of the subject based on the separated signal. This makes it possible to accurately generate an ultrasonic image using only transmitted waves. Further, since the received signal can be separated even if the signal is not frequency-separated and time-separated, the versatility of image generation can be improved.

(7) The transmission control unit 135 causes the predetermined two or more transmission openings 10 to transmit ultrasonic waves at least for a part of the time. This makes it possible to shorten the overall imaging time.

(8) Further, the transmission control unit 135 causes the transmission opening 10 to transmit the ultrasonic signal at a time interval that does not overlap with the reception timing of the component that draws the subject T among the received ultrasonic signals. As a result, the ultrasonic wave can be transmitted from the transmission opening 10 in addition to the reception time of the ultrasonic wave component that does not affect the drawing of the subject T. Therefore, the overall imaging time can be further shortened.

(9) The transmission control unit 135 determines the transmission time interval based on the positional relationship between the transmission opening 10 and the reception opening 20. As a result, it is possible to more effectively suppress the superimposition of the transmitted ultrasonic signal on the component depicting the subject T.

(10) The transmission control unit 135 sets the predetermined time within the time before the ultrasonic signal first transmitted from the transmission opening 10 is received by the reception opening 20. As a result, the two ultrasonic signals can be overlapped to shorten the overall imaging time.

Although the preferred embodiments of the image pickup apparatus and the program of the present invention have been described above, the present disclosure is not limited to the above-described embodiments and can be changed as appropriate.

For example, in the above embodiment, it is assumed that ultrasonic waves are transmitted in an overlapping manner through the four transmission openings 10, but the present invention is not limited to this. Further, although ultrasonic waves are duplicated and transmitted to the transmission openings 10 facing each other in the radial direction of the ring array R, the present invention is not limited to this. It is preferable that the number of transmission openings 10 for transmitting ultrasonic waves in duplicate is 4 to 16. As a result, the received signal for each transmission opening 10 of the transmission source can be effectively separated. Further, the positions of the transmission openings 10 are preferably located at the farthest distance from each other. On the circumference, 180 degrees when there are two transmission openings 10 and 90 degrees when there are four transmission openings. Is desirable.

The difference between the numerical aperture and the image quality is shown below. FIG. 9 shows the result of a computer simulation experiment for determining the numerical aperture of simultaneous transmission. When the numerical apertures to be transmitted simultaneously were 1, 2, 4, and 8, simulations were performed under 100 different conditions, and image reconstruction was performed based on the signal data. The PSNR (peak signal to noise ratio) between the obtained reconstructed image and the true image used in the simulation was evaluated. In the experiment, the PSNR (peak signal to noise ratio) was the minimum when the numerical aperture of simultaneous transmission was 4. From this result, it can be seen that the accuracy decreases when the numerical aperture of simultaneous transmission is 8 or more. It can be said that the numerical aperture of transmission is more preferably 4 or more and 16 or less.

Further, in the above embodiment, the image reproduction unit is provided with the separation unit 142, but the present invention is not limited to this. In this case, the generation execution unit 143 executes image generation using the received signal masked by the mask execution unit 141. As a result, the time until image generation can be shortened as compared with the case where the received signal is separated.

Further, in the above embodiment, the image pickup apparatus 1 is provided with the switch circuit 110 separately from the ring array R, but the present invention is not limited to this. The ring array R (oscillator or element E) may include a transmission / reception circuit 120. As a result, it is not necessary to use a switch circuit. Further, the number of elements E that can be driven at the same time is not limited, and the transmission / reception time and position of the transmission opening 10 and the reception opening 20 can be set more flexibly.

Further, in the above embodiment, the transmission control unit 135 may cause the element E to transmit either a sine wave or a plane wave for the ultrasonic wave transmitted from the element E. Further, the transmission control unit 135 may transmit the duplicated numerical aperture as long as it is equal to or larger than the conventional numerical aperture of transmission, and is not limited to four openings.

Further, in the above embodiment, the generation execution unit 143 may execute the generation of the captured image by using a plurality of image reconstruction methods of the scattered image, the sound velocity CT, and the attenuated image.

Further, in the above embodiment, each of the transmission opening 10 and the reception opening 20 is not limited to the exclusive combination of the elements E. That is, the plurality of transmission openings 10 and reception openings 20 may share one element E among two or more transmission openings 10 and reception openings 20. Further, the transmission opening 10 and the reception opening 20 are not limited to a group of a plurality of adjacent elements E. The transmission opening 10 and the reception opening 20 may be a combination of randomly selected discrete elements E.

Further, in the above embodiment, if it is possible to discriminate between two consecutive received signals, the transmission times of each other may be set to be transmitted in close proximity or in an overlapping manner.

Further, in the above embodiment, the transmission control unit 135 may be configured so that the movement interval of the ring array R in the axial direction can be switched. According to this embodiment, it can be applied to a screening mode that emphasizes time efficiency and sensitivity, which is required for breast cancer screening, and a scrutiny mode that emphasizes specificity used for diagnosis. For example, the image pickup operation screen may be provided with an input unit for prompting selection between the screening mode and the close examination mode. When the scrutiny mode is input, the transmission control unit sets the numerical aperture of simultaneous transmission to 2 or 4 and executes the transmission. On the other hand, when the simple mode is input, the transmission control unit sets the numerical aperture of simultaneous transmission to 8 or 16. In the scrutiny mode, it may be performed without simultaneous transmission. Here, in the screening mode, it is important to shorten the examination time per person. Therefore, applying signal separation by a plurality of transmissions and reducing the imaging time is economically advantageous for both the subject and the inspector.

Generally, in ultrasonic CT imaging, slices which are cross-sectional views of a plane on which an element E is arranged are stacked in the vertical direction to form a 3D image. Therefore, the imaging time increases or decreases depending on the number of slices in the vertical direction in addition to the imaging time of the slices. That is, the transmission control unit 135 can shorten the time by setting the slice interval to be large. However, there is a trade-off between the slice interval and the spatial resolution in the vertical direction of the captured image. Therefore, in the present embodiment, by adjusting the slice interval and performing the simultaneous transmission according to the present invention, it is possible to perform cleaning without lowering the spatial resolution and without extending the entire imaging time. For example, the transmission control unit 135 descends at 2 mm intervals in the screen mode, whereas the transmission control unit 135 may transmit at 1 mm intervals and a plurality of transmissions.
By doing so, although the imaging time is twice as long as usual, the spatial resolution in the three-dimensional space can be maintained by shortening the imaging time in slice units.

Further, the transmission control unit 135 may have a pre-imaging function. In screening imaging, it is possible to measure the outline of the subject in order to search the position of the subject, measure the size, and measure the speed of sound. In the normal imaging mode, the imaging time is extended, but by increasing the number of simultaneous transmission openings, it is possible to acquire simple information in a short time. In addition, the screening mode may be used to perform overall imaging, and the site suspected of having a lesion may be set to be reimaging in the close examination mode. It is possible to generate a CT image with high resolution that is not affected by the spatial resolution that is reduced by increasing the slice interval.

Further, the calibration of the element can be performed in a short time, and the maintainability can be improved. In the present embodiment, the alliance of the ultrasonic elements arranged in a ring shape and the setting of the transmission plane are set by using, for example, a phantom, and regular maintenance is performed. At the time of maintenance, it is desired to shorten the maintenance time in order to stop the operation of the device. According to the present invention, for example, transmission is performed simultaneously from eight multiple transmission openings without a subject installed, and the difference between the obtained received signal and the previously acquired correct received signal is calculated. , It is possible to detect the deviation of the position of the transmitting element.

Further, in the above embodiment, the ring array R is provided with four concave oscillators, but the present invention is not limited to this. The ring array R may include, for example, eight concave oscillators.

Further, in the above embodiment, each element E is provided with both functions of transmitting and receiving ultrasonic waves, but the present invention is not limited to this. For example, a transmitting element or a receiving element having only one of the ultrasonic transmitting function and the receiving function may be used. Further, a plurality of transmitting elements and a plurality of receiving elements may be arranged in a ring shape. Then, an element having both transmission and reception functions, a transmission element, and a reception element may be mixed.

Further, in the above embodiment, the image pickup apparatus 1 may have a separate function of generating an image. The arithmetic unit 130 may be a separate device for the image generation unit 137 and the image display device 140.

Further, in the above embodiment, the transmission openings are a plurality of adjacent elements E, but the elements E may not be adjacent to each other, and transmission may be performed by a combination of randomly selected diffusing transmission elements.

Further, in the above embodiment, the mask execution unit 141 masks and filters the transmitted wave in order to separate the signal of the reflected wave image, but the present invention is not limited to this. For the purpose of reconstructing an attenuation image using a transmitted wave, for example, the mask executing unit 141 can emphasize and acquire the signal due to the transmitted wave by masking the reflected wave.

Further, in the above embodiment, the mask execution unit 141 has processed a part of the time domain with a discontinuous mask, but the present invention is not limited to this. The mask execution unit 141 may use a continuous mask. Further, the mask execution unit 141 may mask a signal having an amplitude higher than that as a transmitted wave with the maximum value of the amplitude as a threshold value.

Further, in the above embodiment, the arithmetic unit stores the learning data in the storage unit M, but the present invention is not limited to this. The arithmetic unit may store the learned learning device learned in another environment in the storage unit M. Further, the arithmetic unit may store the learning data in the storage unit M, while performing the learning process externally.

1 Image pickup device 10 Transmission opening 20 Reception opening 135 Transmission control unit 137 Image generation unit 141 Mask execution unit 142 Separation unit 143 Generation execution unit T Subject

Claims (13)

An image pickup device having a plurality of ultrasonic elements that image a subject using ultrasonic waves.
A transmission opening that includes the plurality of the ultrasonic elements and transmits ultrasonic waves toward the subject.
A reception opening that receives the reflected and transmitted waves of ultrasonic waves transmitted to the subject and outputs them as a reception signal.
A transmission control unit that controls the transmission of ultrasonic waves,
Equipped with
The transmission control unit
An imaging device that transmits ultrasonic waves from two or more predetermined transmission openings among a plurality of transmission openings within a predetermined time. The imaging device according to claim 1, wherein the transmission opening and the reception opening are arranged in the vicinity of the subject and on the same plane. The imaging device according to claim 1 or 2, further comprising an image generation unit that generates an captured image using the output received signal. The image pickup device according to claim 3, wherein the image generation unit separates the received ultrasonic signal into a signal for each transmission opening of the transmission source. The image generation unit
Of the output received signals, a mask execution unit that masks the signal indicating the transmitted wave, and
A separation unit that separates the masked received signal into a signal for each transmission opening of the transmission source, and a separation unit.
A generation execution unit that executes image generation of the subject based on the separated signals, and a generation execution unit.
The image pickup apparatus according to claim 4. The image generation unit
Of the output received signals, a mask execution unit that masks the signal indicating the reflected wave, and
A separation unit that separates the masked received signal into a signal for each transmission opening of the transmission source, and a separation unit.
A generation execution unit that executes image generation of the subject based on the separated signals, and a generation execution unit.
Further prepare,
The imaging device according to claim 4. The image pickup device according to claim 3, wherein the image generation unit separates overlapping signals in a four-dimensional space at an arbitrary scattering point or a specific receiving element in the image pickup region by using deep learning. The imaging device according to any one of claims 1 to 7, wherein the transmission control unit transmits ultrasonic waves to two or more predetermined transmission openings at least for a part of the time. The method according to any one of claims 1 to 7, wherein the transmission control unit transmits an ultrasonic signal to the transmission opening at a time interval that does not overlap with the reception timing of the component that draws the subject among the received ultrasonic signals. Imaging device. The imaging device according to claim 8, wherein the transmission control unit determines a transmission interval based on the positional relationship between the transmission opening and the reception opening. The transmission control unit is set according to any one of claims 1 to 9 in which the transmission control unit sets the ultrasonic signal first transmitted from one transmission opening within the time before being received by the reception opening for the predetermined time. The imaging device described. The imaging device according to any one of claims 1 to 10, wherein the transmission control unit is configured to be capable of switching the axial movement interval of the ring array. A plurality of transmission openings including a plurality of elements and transmitting ultrasonic waves to a subject, and a plurality of reception openings in which ultrasonic waves receive reflected waves and transmitted waves in the subject and output them as reception signals. It is a program that makes a computer function as an image pickup device equipped with
The computer
A transmission control unit that controls the transmission of ultrasonic waves, and is a program that functions as a transmission control unit that transmits ultrasonic waves from two or more predetermined transmission openings among a plurality of transmission openings within a predetermined time. ..

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