Ultrasound diagnostic device and control method for ultrasound diagnostic device

Abstract

The present invention provides an ultrasound diagnostic apparatus and a control method for the ultrasound diagnostic apparatus that can accurately produce a first ultrasound image and a second ultrasound image that are consistent with each other. [Solution] The ultrasound diagnostic device includes an image acquisition unit (34) that acquires a first ultrasound image and a second ultrasound image, each capturing a different first and second cross-section of the subject's heart; a first measurement unit (26) that acquires a first measurement value of a predetermined measurement target depicted in the first cross-section from the first ultrasound image; a second measurement unit (27) that acquires a second measurement value of a predetermined measurement target depicted in the second cross-section from the second ultrasound image; a consistency calculation unit (28) that calculates the consistency between the first ultrasound image and the second ultrasound image by comparing the first measurement value and the second measurement value with each other; and a notification unit (29) that notifies the user of the consistency.

Description

Technical Field

[0001] The present invention relates to an ultrasonic diagnostic apparatus for imaging the heart of a subject and a control method for an ultrasonic diagnostic apparatus.

Background Art

[0002] Conventionally, so-called cardiac output has been calculated by capturing an ultrasonic image representing a tomographic plane of the heart of a subject using a so-called ultrasonic diagnostic apparatus and analyzing the captured ultrasonic image. Calculation of cardiac output is usually performed through the following calculation steps: (1) measuring the diameter of the left ventricular outflow tract in a first ultrasonic image representing the so-called parasternal left ventricular long-axis section during the mid-systolic phase of the heart, and calculating the cross-sectional area of the left ventricular outflow tract; (2) calculating the velocity-time integral of blood flow in the left ventricular outflow tract by the so-called pulsed Doppler method using a second ultrasonic image representing the so-called apical five-chamber section or the so-called apical three-chamber section; (3) calculating the so-called stroke volume from the product of the cross-sectional area of the left ventricular outflow tract and the velocity-time integral of blood flow in the left ventricular outflow tract; and (4) calculating cardiac output from the product of the stroke volume and the heart rate.

[0003] As described above, measurement of stroke volume and cardiac output requires a plurality of procedures, so various techniques have been developed to easily measure stroke volume and cardiac output. For example, Patent Document 1 discloses automatically setting a region of interest at the left ventricular outflow tract in an ultrasonic image, setting a plurality of candidates for a Doppler gate within the set region of interest, and selecting the optimal position of the Doppler gate based on the Doppler spectral waveform calculated for each of the plurality of Doppler gate candidates.

Prior Art Literature

Patent Literature

[0004]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0005] However, if a second ultrasound image representing, for example, a five-chamber or three-chamber apical view cannot be properly visualized, even using the technology described in Patent Document 1, it may not be possible to set the Doppler gate in the appropriate position, and as a result, an appropriate time-varying waveform of blood flow velocity measured within the Doppler gate may not be obtained. In this case, the user often has to repeat a series of operations: adjusting the position of the ultrasound probe to a position where the second ultrasound image can be properly visualized, setting the Doppler gate within the second ultrasound image, and then checking the time-varying waveform of blood flow velocity obtained. This can take a considerable amount of time to obtain an appropriate second ultrasound image.

[0006] This invention was made to solve the problems of the past, and aims to provide an ultrasound diagnostic apparatus and a control method for the ultrasound diagnostic apparatus that can accurately produce a first ultrasound image and a second ultrasound image that are consistent with each other. [Means for solving the problem]

[0007] The above objective can be achieved with the following configuration. [1] An image acquisition unit that acquires a first ultrasound image and a second ultrasound image, each capturing a different first and second cross-section of the subject's heart, A first measurement unit that acquires a first measurement value of a defined measurement target depicted in a first cross-section from a first ultrasound image, A second measurement unit acquires a second measurement value of a defined measurement target depicted in a second cross-section from a second ultrasound image, A consistency calculation unit calculates the consistency between the first ultrasound image and the second ultrasound image by comparing the first measurement value obtained by the first measurement unit and the second measurement value obtained by the second measurement unit with each other. A notification unit that informs the user of the consistency calculated by the consistency calculation unit. An ultrasound diagnostic device equipped with the following features. [2] The image acquisition unit acquires a first ultrasound image with the parasternal left ventricle long axis as the first cross-section and a second ultrasound image with the apical five-chamber or apical three-chamber cross-section as the second cross-section. The ultrasound diagnostic apparatus described in [1] measures the left ventricular outflow tract diameter as the first and second measured values, respectively. [3] The consistency calculation unit calculates the difference or ratio between the first measured value and the second measured value as consistency, as described in [1] or [2]. [4] Equipped with a monitor, The notification unit is an ultrasound diagnostic apparatus as described in any of [1] to [3], which displays the consistency calculated by the consistency calculation unit on a monitor. [5] Equipped with a speaker, The notification unit outputs the consistency calculated by the consistency calculation unit as sound from a speaker. This is an ultrasound diagnostic apparatus as described in any of [1] to [3]. [6] Equipped with a warning lamp, The ultrasound diagnostic apparatus according to any one of [1] to [3], wherein the notification unit illuminates a warning lamp when the consistency calculated by the consistency calculation unit falls below a predetermined threshold. [7] Equipped with an ultrasonic probe, The ultrasound probe has a built-in vibrator. The ultrasound diagnostic apparatus according to any one of [1] to [3], wherein the notification unit vibrates the vibrator when the consistency calculated by the consistency calculation unit falls below a predetermined threshold. [8] A velocity-time integral value calculation unit that calculates the velocity-time integral value of left ventricular outflow tract blood flow from the second ultrasound image, A cardiac output calculation unit calculates cardiac output based on the left ventricular outflow tract diameter as a first measurement value acquired by the first measurement unit and the velocity-time integral value calculated by the velocity-time integral value calculation unit. Equipped with, The notification unit notifies the user if the cardiac output calculated by the cardiac output calculation unit deviates from a specified value, as described in any of [1] to [7] of the ultrasound diagnostic device. [9] First ultrasound images and second ultrasound images are obtained, each capturing a different first and second cross-section of the subject's heart. The first measurement value of a defined measurement target depicted in the first cross-section is obtained from the first ultrasound image. The second measurement value of the defined measurement target, depicted in the second cross-section from the second ultrasound image, is obtained. By comparing the acquired first and second measurement values ​​with each other, the consistency between the first ultrasound image and the second ultrasound image is calculated. The user is notified of the calculated consistency. A method for controlling an ultrasound diagnostic device. [Effects of the Invention]

[0008] The present invention provides an ultrasound diagnostic device comprising: an image acquisition unit that acquires a first ultrasound image and a second ultrasound image, each capturing a different first and second cross-section of the subject's heart; a first measurement unit that acquires a first measurement value of a predetermined measurement target depicted in the first cross-section from the first ultrasound image; a second measurement unit that acquires a second measurement value of a predetermined measurement target depicted in the second cross-section from the second ultrasound image; a consistency calculation unit that calculates the consistency between the first ultrasound image and the second ultrasound image by comparing the first measurement value acquired by the first measurement unit and the second measurement value acquired by the second measurement unit; and a notification unit that notifies the user of the consistency calculated by the consistency calculation unit. As a result, the device can accurately depict a first ultrasound image and a second ultrasound image that are consistent with each other. [Brief explanation of the drawing]

[0009] [Figure 1] This is a block diagram showing the configuration of an ultrasound diagnostic device according to an embodiment of the present invention. [Figure 2] This is a block diagram showing the internal configuration of the transmitting and receiving circuit in an embodiment of the present invention. [Figure 3] This is a block diagram showing the internal configuration of the image generation unit in an embodiment of the present invention. [Figure 4]It is a diagram showing an example of a first ultrasonic image representing a parasternal left ventricular long-axis cross-section. [Figure 5] It is a diagram showing an example of a second ultrasonic image representing an apical five-chamber cross-section. [Figure 6] It is a diagram showing an example of a second ultrasonic image representing an apical three-chamber cross-section. [Figure 7] It is a diagram showing a display example of the consistency between a first ultrasonic image and a second ultrasonic image on a monitor. [Figure 8] It is a block diagram showing the internal configuration of a velocity-time integral value calculation unit. [Figure 9] It is a flowchart showing the operation of the ultrasonic diagnostic apparatus according to an embodiment of the present invention. [Figure 10] It is a block diagram partially showing the configuration of a first modification of the ultrasonic diagnostic apparatus according to an embodiment of the present invention. [Figure 11] It is a block diagram partially showing the configuration of a second modification of the ultrasonic diagnostic apparatus according to an embodiment of the present invention. [Figure 12] It is a block diagram partially showing the configuration of a third modification of the ultrasonic diagnostic apparatus according to an embodiment of the present invention. Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. The following description of the structural requirements is made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In this specification, a numerical range expressed using "~" means a range that includes the numerical values described before and after "~" as the lower limit and the upper limit. In this specification, "identical" and "same" are intended to include error ranges generally accepted in this technical field.

[0011] Embodiment Figure 1 shows the configuration of an ultrasound diagnostic apparatus according to an embodiment of the present invention. The ultrasound diagnostic apparatus comprises an ultrasound probe 1 and a device body 2 that are connected to each other by so-called wired communication or so-called wireless communication.

[0012] The ultrasonic probe 1 comprises a transducer array 11 and a transmitting / receiving circuit 12 connected thereto.

[0013] The main unit 2 of the device includes an image generation unit 21 connected to the transmitting / receiving circuit 12. In the main unit 2, the display control unit 22 and the monitor 23 are sequentially connected to the image generation unit 21. An image memory 24 and an image recognition unit 25 are also connected to the image generation unit 21. A first measurement unit 26 and a second measurement unit 27 are connected to the image recognition unit 25. A consistency calculation unit 28 is connected to the first measurement unit 26 and the second measurement unit 27. A notification unit 29 is connected to the consistency calculation unit 28. A velocity-time integral value calculation unit 30 is also connected to the image recognition unit 25. A cardiac output calculation unit 31 is connected to the velocity-time integral value calculation unit 30. The cardiac output calculation unit 31 is connected to the display control unit 22 and the notification unit 29. Furthermore, the device control unit 32 is connected to the transmitting / receiving circuit 12, image generation unit 21, display control unit 22, image recognition unit 25, first measurement unit 26, second measurement unit 27, consistency calculation unit 28, notification unit 29, velocity-time integral value calculation unit 30, and cardiac output calculation unit 31. An input device 33 is connected to the device control unit 32.

[0014] The image acquisition unit 34 is composed of a transmitting / receiving circuit 12 and an image generation unit 21. In addition, the processor 35 for the main unit 2 is composed of the image generation unit 21, display control unit 22, image recognition unit 25, first measurement unit 26, second measurement unit 27, consistency calculation unit 28, notification unit 29, velocity-time integral value calculation unit 30, cardiac output calculation unit 31, and device control unit 32.

[0015] The transducer array 11 of the ultrasonic probe 1 has a plurality of ultrasonic transducers arranged in one or two dimensions. Each of these ultrasonic transducers transmits ultrasound according to a drive signal supplied from the transmitting / receiving circuit 12, and also receives ultrasonic echoes from the subject and outputs a signal based on the ultrasonic echoes. Each ultrasonic transducer is constructed by forming electrodes at both ends of a piezoelectric body made of, for example, a piezoelectric ceramic represented by PZT (Lead Zirconate Titanate), a polymer piezoelectric element represented by PVDF (Poly Vinylidene Di Fluoride), or a piezoelectric single crystal represented by PMN-PT (Lead Magnesium Niobate-Lead Titanate).

[0016] The image acquisition unit 34, which consists of a transmitting / receiving circuit 12 and an image generation unit 21, acquires multiple frames of ultrasound images as moving images of the subject's heart by transmitting and receiving an ultrasound beam using an ultrasound probe 1.

[0017] The transmitting / receiving circuit 12 transmits ultrasonic waves from the transducer array 11 and generates a sound line signal based on the received signal acquired by the transducer array 11, under the control of the device control unit 32. As shown in Figure 2, the transmitting / receiving circuit 12 includes a pulser 41 connected to the transducer array 11, and an amplifier 42, an AD (Analog to Digital) converter 43, and a beamformer 44 connected sequentially in series from the transducer array 11.

[0018] The pulser 41 includes, for example, multiple pulse generators, and based on a transmission delay pattern selected in response to a control signal from the device control unit 32, it supplies each drive signal to the multiple ultrasonic transducers of the transducer array 11, adjusting the delay amount, so that the ultrasonic waves transmitted from the transducers form an ultrasonic beam. In this way, when a pulsed or continuous wave voltage is applied to the electrodes of the ultrasonic transducers of the transducer array 11, the piezoelectric material expands and contracts, generating pulsed or continuous wave ultrasonic waves from each ultrasonic transducer, and an ultrasonic beam is formed from the combined wave of these ultrasonic waves.

[0019] The transmitted ultrasonic beam is reflected from a target, such as a part of the subject, and propagates toward the transducer array 11 of the ultrasonic probe 1. The ultrasonic echo propagating toward the transducer array 11 is received by each ultrasonic transducer that makes up the transducer array 11. At this time, each ultrasonic transducer that makes up the transducer array 11 expands and contracts upon receiving the propagating ultrasonic echo, generating a received signal which is an electrical signal, and outputs these received signals to the amplification unit 42.

[0020] The amplification unit 42 amplifies the signals input from each ultrasonic transducer constituting the transducer array 11 and transmits the amplified signals to the AD conversion unit 43. The AD conversion unit 43 converts the signals transmitted from the amplification unit 42 into digital received data. The beamformer 44 performs so-called receive focus processing by adding each received data received from the AD conversion unit 43 with a corresponding delay. Through this receive focus processing, each received data converted by the AD conversion unit 43 is phase-corrected and added together, and a sound ray signal with a focused ultrasonic echo is obtained.

[0021] As shown in Figure 3, the image generation unit 21 has a configuration in which a signal processing unit 45, a DSC (Digital Scan Converter) 46, and an image processing unit 47 are connected in series in sequence.

[0022] The signal processing unit 45 receives the sound line signal from the transmitting / receiving circuit 12, applies a sound velocity value set by the device control unit 32 to correct for attenuation due to distance according to the depth of the ultrasonic reflection position, and then performs envelope detection processing to generate a B-mode image signal, which is tomographic image information of the tissue within the subject.

[0023] The DSC46 converts the B-mode image signal generated by the signal processing unit 45 into an image signal that follows the scanning method of a normal television signal (raster conversion). The image processing unit 47 performs various necessary image processing, such as gradation processing, on the B-mode image signal input from the DSC 46, and then sends the B-mode image signal to the display control unit 22, image memory 24, and image recognition unit 25. Hereafter, the B-mode image signal processed by the image processing unit 47 will be referred to as an ultrasonic image.

[0024] In the present invention, the image acquisition unit 34 acquires a first ultrasound image and a second ultrasound image, respectively, which are images of different first and second cross-sections of the subject's heart. The image acquisition unit 34 can acquire an ultrasound image representing a so-called parasternal left ventricular long-axis section as a first ultrasound image U1 representing the first cross-section. The parasternal left ventricular long-axis section is a cross-section that includes the left ventricle, left ventricular outflow tract T, left atrium, and right ventricle. The image acquisition unit 34 can also acquire an ultrasound image representing a so-called apical five-chamber section or a so-called apical three-chamber section as a second ultrasound image U2 representing the second cross-section. The apical five-chamber section is a cross-section of the heart that includes the five lumens of the left ventricle, left ventricular outflow tract, left atrium, right ventricle, and right atrium. Furthermore, the apical three-chamber view is a cross-section of the heart that includes the three cavities of the left ventricle, left atrium, and right ventricle. Both the apical five-chamber view and the apical three-chamber view include the left ventricular outflow tract T.

[0025] In the following explanation, the image acquisition unit 34 will primarily describe the case where it acquires an ultrasound image representing the parasternal left ventricle long axis section as the first ultrasound image U1 and an ultrasound image representing the apical five-chamber section or an apical three-chamber section as the second ultrasound image U2. However, the image acquisition unit 34 can also acquire an ultrasound image representing the apical five-chamber section or an apical three-chamber section as the first ultrasound image U1 and an ultrasound image representing the parasternal left ventricle long axis section as the second ultrasound image U2.

[0026] The image memory 24 is a memory that stores the first ultrasound image U1 and the second ultrasound image U2 acquired by the image acquisition unit 34. The user can use the first ultrasound image U1 and the second ultrasound image U2 stored in the image memory 24 to check them after the examination, for example. As the image memory 24, recording media such as flash memory, HDD (Hard Disk Drive), SSD (Solid State Drive), FD (Flexible Disk), MO disk (Magneto-Optical disk), MT (Magnetic Tape), RAM (Random Access Memory), CD (Compact Disc), DVD (Digital Versatile Disc), SD card (Secure Digital card), or USB memory (Universal Serial Bus memory) can be used.

[0027] The image recognition unit 25 recognizes either the first or second cross-section from the ultrasound image acquired by the image acquisition unit 34, namely, the parasternal left ventricular long-axis section, the apical five-chamber section, or the apical three-chamber section. The image recognition unit 25 can recognize any of the parasternal left ventricular long-axis section, the apical five-chamber section, or the apical three-chamber section by pre-storing template data representing typical image patterns of these sections and searching ultrasound images using the template data, a method known as template matching. The image recognition unit 25 can also have a pre-trained model in machine learning that has learned from a large number of ultrasound images representing the parasternal left ventricular long-axis section, the apical five-chamber section, and the apical three-chamber section, and can output recognition results by inputting ultrasound images into the pre-trained model.

[0028] The image recognition unit 25 sends a first ultrasound image U1, in which, for example, a parasternal left ventricular long-axis section is recognized, to the first measurement unit 26, and a second ultrasound image U2, representing an apical five-chamber section or an apical three-chamber section, to the second measurement unit 27 and the velocity-time integral value calculation unit 30.

[0029] The first measurement unit 26 acquires a first measurement value of a defined measurement target depicted in a first cross-section from the first ultrasound image U1. The first measurement unit 26 can measure, for example, the diameter of the left ventricular outflow tract T depicted in the parasternal left ventricle long axis cross-section, i.e., the left ventricular outflow tract diameter, as the first measurement value of a defined measurement target depicted in the first cross-section. In this case, the first measurement unit 26 can place a measurement line ML1 in the left ventricular outflow tract T, for example as shown in Figure 4, and measure the length of the measurement line ML1 as the left ventricular outflow tract diameter. The first measurement unit 26 can place the measurement line ML1 at a position specified by the user on the first ultrasound image U1, for example via an input device 33.

[0030] The second measurement unit 27 acquires a second measurement value of a defined measurement target depicted in the second cross-section from the second ultrasound image U2. The defined measurement target in the second cross-section is the same as the defined measurement target in the first cross-section. The second measurement unit 27 can, for example, measure the diameter of the left ventricular outflow tract T depicted in the apical five-chamber or apical three-chamber cross-section, i.e., the left ventricular outflow tract diameter, as the second measurement value of the defined measurement target depicted in the second cross-section. In this case, the second measurement unit 27 can, for example, place a measurement line ML2 in the left ventricular outflow tract T as shown in Figures 5 and 6, and measure the length of the measurement line ML2 as the left ventricular outflow tract diameter. The second measurement unit 27 can, for example, place the measurement line ML2 at a position specified by the user on the second ultrasound image U2 via an input device 33.

[0031] Here, the left ventricular outflow tract diameter in the parasternal long-axis view and the left ventricular outflow tract diameter in the apical five-chamber view are ideally equal to each other, and the left ventricular outflow tract diameter in the parasternal long-axis view and the left ventricular outflow tract diameter in the apical three-chamber view are also ideally equal to each other. Thus, as the measurement target in the first and second views, an object is set such that the first measurement value and the second measurement value are ideally equal to each other.

[0032] The consistency calculation unit 28 calculates the consistency between the first ultrasound image U1 and the second ultrasound image U2 by comparing the first measurement value obtained by the first measurement unit 26 and the second measurement value obtained by the second measurement unit 27. The consistency calculation unit 28 can calculate the difference or ratio between the first measurement value and the second measurement value as the consistency between the first ultrasound image U1 and the second ultrasound image U2. Alternatively, the consistency calculation unit 28 can also calculate the consistency using the following formula (1), where the first measurement value is MV1, the second measurement value is MV2, and the consistency value is J[%].

number

[0033] Note that the function min(A,B) in equation (1) is a function that outputs the smaller of the two values ​​A and B. For example, if value A > value B, then min(A,B) = B.

[0034] Since the first and second measurements are ideally equal, the closer the difference between the first and second measurements is to 0, and the closer the ratio between the first and second measurements is to 1, the higher the consistency between the first ultrasound image U1 and the second ultrasound image U2 can be considered. Conversely, the larger the absolute value of the difference between the first and second measurements, and the greater the ratio between the first and second measurements is greater than 1 or closer to 0, the lower the consistency between the first ultrasound image U1 and the second ultrasound image U2 can be considered. Furthermore, the consistency value J calculated by formula (1) will be closer to 100 as the first and second measurements are close, and closer to 0 as the difference between the first and second measurements is large.

[0035] A high consistency value calculated by the consistency calculation unit 28 indicates that a second ultrasound image U2 with high consistency to the first ultrasound image U1 has been obtained, meaning that the second ultrasound image U2 has been acquired appropriately. Conversely, a low consistency value indicates that the second ultrasound image U2 has not been acquired appropriately.

[0036] The notification unit 29 notifies the user of the consistency calculated by the consistency calculation unit 28. The notification unit 29 can display the consistency on the monitor 23 in the form of a message M for notifying the consistency, for example, as shown in Figure 7. The notification unit 29 can store a predetermined consistency threshold for consistency, and if the consistency calculated by the consistency calculation unit 28 falls below the consistency threshold, it can display a message M on the monitor 23 indicating that the ultrasound probe 1 should be moved, tilted, or rotated to reacquire the second ultrasound image U2. If the consistency is equal to or greater than the consistency threshold, the notification unit 29 can display a message M on the monitor 23 indicating that the second ultrasound image U2 has been acquired appropriately.

[0037] Normally, in order to confirm whether the second ultrasound image U2, which represents the five-chamber or three-chamber view of the apex of the heart, has been properly acquired, a series of operations are often repeated in which a so-called Doppler gate is placed in the left ventricular outflow tract T in the second ultrasound image U2, and a so-called pulsed Doppler method is used within the Doppler gate to acquire the time-varying waveform of blood flow velocity in the left ventricular outflow tract T, and then the time-varying waveform is checked. This process can take a considerable amount of time to obtain a proper second ultrasound image U2. By checking the consistency reported by the notification unit 29, the user can easily understand whether the second ultrasound image U2 has been properly acquired and accurately visualize the second ultrasound image U2.

[0038] The velocity-time integral value calculation unit 30 calculates the velocity-time integral value of blood flow in the left ventricular outflow tract T, i.e., left ventricular outflow tract blood flow, from the second ultrasound image U2. As shown in Figure 8, the velocity-time integral value calculation unit 30 has a configuration in which a gate setting unit 51, a quadrature detection unit 52, a high-pass filter 53, a fast Fourier transform unit 54, a Doppler waveform acquisition unit 55, and an integral value calculation unit 56 are connected in series.

[0039] The gate setting unit 51 sets a so-called Doppler gate on the ultrasound image U acquired by the image acquisition unit 34, which is used to calculate the velocity-time integral value of blood flow using the so-called pulsed Doppler method. For example, the gate setting unit 51 sets a Doppler gate on the left ventricular outflow tract T on the second ultrasound image U2.

[0040] The gate setting unit 51 can set a Doppler gate at a position specified by the user, for example, via the input device 33. The gate setting unit 51 can also recognize the left ventricular outflow tract T shown in the second ultrasound image U2 by analyzing the second ultrasound image U2, for example, and set a Doppler gate on the recognized left ventricular outflow tract T. In this case, the gate setting unit 51 can recognize the left ventricular outflow tract T by, for example, a so-called template matching method in which it stores typical image patterns of the left ventricular outflow tract T in the apical five-chamber and apical three-chamber sections and searches the second ultrasound image U2 using these image patterns, or by using a trained model in machine learning that has learned the image patterns of the left ventricular outflow tract T in the apical five-chamber and apical three-chamber sections.

[0041] The quadrature detection unit 52 converts the sound line signal into a complex signal by quadrature detection, by mixing the sound line signal received from the transmitting / receiving circuit 12 with a carrier signal of a reference frequency.

[0042] The high-pass filter 53 functions as a so-called wall filter, removing frequency components originating from the movement of the subject's internal tissues from the complex signal generated by the quadrature detection unit 52.

[0043] The Fast Fourier Transform unit 54 performs a Fourier transform on the complex signals of multiple sample points to perform frequency analysis, determine the blood flow velocity, and generate a spectral signal.

[0044] The Doppler waveform acquisition unit 55 acquires a Doppler waveform image signal by aligning the spectral signal generated by the fast Fourier transform unit 54 on the time axis and representing the magnitude of each frequency component with brightness. The Doppler waveform image signal is what is commonly called a Doppler image, and it represents the time-varying waveform of blood flow velocity. The horizontal axis shows the time axis, the vertical axis shows the Doppler shift frequency, i.e., the flow velocity, and the brightness of the waveform represents the power at each frequency component.

[0045] The integral value calculation unit 56 identifies the duration of one heartbeat in the Doppler waveform image signal and calculates the velocity-time integral value by integrating the flow velocity value in the Doppler waveform image signal over the duration of one heartbeat. The integral value calculation unit 56 can, for example, analyze the Doppler waveform image signal to identify the repeating unit of the waveform in the Doppler waveform image signal, and identify the duration to which the identified repeating unit belongs as the duration of one heartbeat.

[0046] Since the gate setting unit 51 sets a Doppler gate on the left ventricular outflow tract T in the second ultrasound image U2, the velocity-time integral value calculated in this way by the velocity-time integral value calculation unit 30 is the value obtained by integrating the velocity of blood flowing through the left ventricular outflow tract T over the duration of one heartbeat. The velocity-time integral value can be used, along with the left ventricular outflow tract diameter measured in an ultrasound image representing the so-called parasternal left ventricle long axis section, to calculate the so-called stroke volume and cardiac output.

[0047] The process of calculating the velocity-time integral value by the quadrature detection unit 52, high-pass filter 53, fast Fourier transform unit 54, Doppler waveform acquisition unit 55, and integral value calculation unit 56 is performed after a drive signal is sent to the transducer array 11 to transmit ultrasonic waves in a pulsed manner under the control of the transmitting / receiving circuit 12 and the device control unit 32.

[0048] The cardiac output calculation unit 31 calculates cardiac output based on the left ventricular outflow tract diameter, which is a first measurement value obtained by the first measurement unit 26, and the velocity-time integral value calculated by the velocity-time integral value calculation unit 30. More specifically, the cardiac output calculation unit 31 calculates the stroke volume by multiplying the left ventricular outflow tract diameter and the velocity-time integral value, and then calculates cardiac output by multiplying the calculated stroke volume by the heart rate. For example, the cardiac output calculation unit 31 can calculate the heart rate by identifying the repetitive waveform in the time-varying waveform of blood flow velocity obtained by the Doppler waveform acquisition unit 55 of the velocity-time integral value calculation unit 30, and then taking the reciprocal of the period of the identified repetitive waveform.

[0049] The notification unit 29 can notify the user that the cardiac output calculated by the cardiac output calculation unit 31 is deviating from a specified value, that the cardiac output is showing an abnormal value, and that the second ultrasound image U2 is not being properly depicted. The specified value for cardiac output can be set, for example, within the range of 2500 mL to 4500 mL. Deviations from the specified value for cardiac output may occur, for example, when blood flows backward in the aorta of the heart due to heart disease.

[0050] The display control unit 22, under the control of the device control unit 32, performs predetermined processing on the first ultrasound image U1 and the second ultrasound image U2 acquired by the image acquisition unit 34, the content of the notification by the notification unit 29, and the stroke volume or cardiac output calculated by the cardiac output calculation unit 31, and displays them on the monitor 23.

[0051] The monitor 23 displays the first ultrasound image U1 and the second ultrasound image U2, the content of the notification from the notification unit 29, and the stroke volume or cardiac output calculated by the cardiac output calculation unit 31, under the control of the display control unit 22, and has a display device such as an LCD (Liquid Crystal Display) or an organic EL display (Organic Electroluminescence Display).

[0052] The input device 33 is for the user to perform input operations and consists of devices such as a keyboard, mouse, trackball, touchpad, and touch sensor placed on top of the monitor 23.

[0053] In this embodiment, each process in the processor 35 is executed on any computer. Alternatively, any computer may execute these processes using a processor as hardware, a program as software, or a combination thereof. In that case, the processor is configured to work in cooperation with the program to execute the various processes in this embodiment, and can function as a unit or means in this embodiment. Furthermore, the execution order of the processes by the processor is not limited to the order described and may be changed as appropriate. Any computer may be a general-purpose computer, a computer designed for a specific purpose, a workstation, or any other system capable of executing each process.

[0054] The processor 35 may be composed of one or more hardware components, and the type of hardware is not limited. For example, the processor 35 may be composed of hardware such as a CPU (Central Processing Unit), MPU (Micro Processing Unit), FPGA (Field Programmable Gate Array) or other programmable logic devices, an ASIC (Application Specific Integrated Circuit) or other dedicated circuit for executing specific processing, a GPU (Graphic Processing Unit), or an NPU (Neural Processing Unit). Furthermore, the type of hardware may be a combination of different types of hardware. When multiple hardware components are configured to execute one or more processes of a given processor, these multiple hardware components may reside in physically separate devices or in the same device. Also, in any embodiment, the order of each process performed by the processor 35 is not limited to the order described above and may be changed as appropriate. The hardware is composed of electrical circuits (circuitry) that combine circuit elements such as semiconductor elements.

[0055] Furthermore, the program may be firmware or software such as microcode. Alternatively, the program may be, for example, a set of program modules, each function of which may be implemented by a processor configured to perform its respective function. The program may be program code or multiple code segments stored on one or more non-temporary computer-readable media (e.g., storage media or other storage). The program may be divided and stored on multiple non-temporary computer-readable media located on physically separate devices. Program code or code segments may represent any combination of procedures, functions, subprograms, routines, subroutines, modules, software packages, classes, or instructions, data structures, or program statements. Program code or code segments may be connected to other code segments or hardware circuits by sending and receiving information, data, arguments, parameters, or memory contents.

[0056] Next, the operation of the ultrasound diagnostic device according to the embodiment will be described with reference to the flowchart shown in Figure 9. Here, we will describe an example in which an ultrasound image representing the parasternal left ventricle long axis section is acquired as the first ultrasound image U1, and an ultrasound image representing the apical five-chamber section is acquired as the second ultrasound image U2.

[0057] In step S1, the image acquisition unit 34 acquires a first ultrasound image U1 representing a parasternal left ventricle long-axis section. At this time, under the control of the device control unit 32, ultrasound transmission and reception are started from multiple transducers of the transducer array 11 according to the drive signal from the pulser 41 of the ultrasound probe 1's transmit / receive circuit 12. Ultrasound echoes from within the subject are received by multiple transducers of the transducer array 11, the received signal, which is an analog signal, is output to the amplification unit 42 for amplification, and then AD converted by the AD conversion unit 43 to acquire the received data.

[0058] The beamformer 44 performs reception focus processing on this received data, and the resulting sound line signal is sent to the image generation unit 21 of the main body 2, where an ultrasonic image is generated. At this time, the signal processing unit 45 of the image generation unit 21 performs attenuation correction according to the depth of the ultrasonic reflection position and envelope detection processing on the sound line signal, and the DSC 46 converts it into an image signal that follows the scanning method of a normal television signal, and the image processing unit 47 performs various necessary image processing such as gradation processing. The first ultrasonic image U1 generated in step S1 in this way is sent to the display control unit 22 and the first measurement unit 26.

[0059] In step S2, the first measurement unit 26 acquires the left ventricular flow path diameter as the first measurement value of the measurement target determined from the first ultrasound image U1 acquired in step S1. The first measurement unit 26 can, for example, place a measurement line ML1 in the left ventricular outflow tract T as shown in Figure 4, and measure the length of the measurement line ML1 as the left ventricular outflow tract diameter. The first measurement unit 26 can, for example, place the measurement line ML1 at a position specified by the user on the first ultrasound image U1 via an input device 33.

[0060] In step S3, the user adjusts the ultrasound probe 1 to a position and orientation for acquiring a second ultrasound image U2 representing the five-chamber cross-section of the apex of the heart by moving and tilting the ultrasound probe 1, and the image acquisition unit 34 acquires the second ultrasound image U2 representing the five-chamber cross-section of the apex of the heart. The process for generating the second ultrasound image U2 is the same as the process for generating the first ultrasound image U1 in step S1, so the explanation of the process for generating the second ultrasound image U2 will be omitted.

[0061] In step S4, the second measurement unit 27 acquires the left ventricular flow path diameter as a second measurement value of the measurement target determined from the second ultrasound image U2 acquired in step S3. The second measurement unit 27 can, for example, place a measurement line ML2 in the left ventricular outflow tract T as shown in Figure 5, and measure the length of the measurement line ML2 as the left ventricular outflow tract diameter. The second measurement unit 27 can, for example, place the measurement line ML2 at a position specified by the user on the second ultrasound image U2 via an input device 33.

[0062] In step S5, the consistency calculation unit 28 calculates the consistency between the first ultrasound image U1 and the second ultrasound image U2 by comparing the first measurement value obtained in step S2 and the second measurement value obtained in step S4 with each other. The consistency calculation unit 28 can calculate the difference or ratio between the first measurement value and the second measurement value as the consistency between the first ultrasound image U1 and the second ultrasound image U2. Alternatively, the consistency calculation unit 28 can also calculate the consistency using formula 1.

[0063] In step S6, the notification unit 29 notifies the user of the consistency calculated in step S5. The notification unit 29 can notify the user of the consistency by displaying message M on the monitor 23, for example, as shown in Figure 7. The notification unit 29 can also notify the user whether the second ultrasound image U2 has been acquired properly by comparing the consistency value calculated in step S5 with a pre-stored consistency threshold. The user can check the notification content from the notification unit 29 and determine whether the second ultrasound image U2 has been acquired properly, or whether it is necessary to adjust the position and orientation of the ultrasound probe 1 in order to acquire the second ultrasound image U2 properly.

[0064] In step S7, the device control unit 32 determines whether or not to reacquire the second ultrasound image U2. For example, if the user confirms the notification content in step S6 and determines that the second ultrasound image U2 has not been properly acquired, and inputs an instruction via the input device 33 to reacquire the second ultrasound image U2, the device control unit 32 determines to reacquire the second ultrasound image U2. For example, if the user confirms the notification content in step S6 and determines that the second ultrasound image U2 has been properly acquired, and inputs an instruction via the input device 33 not to reacquire the second ultrasound image U2, the device control unit 32 determines not to reacquire the second ultrasound image U2.

[0065] If it is determined in step S7 that the second ultrasound image U2 should be acquired again, the process returns to step S3 and the second ultrasound image U2 is acquired again. At this time, the user adjusts the position or orientation of the ultrasound probe 1 in order to properly acquire the second ultrasound image U2. After that, the processes from steps S2 to S7 are performed. In this way, the processes from steps S3 to S7 are repeated until it is determined in step S7 that the second ultrasound image U2 should not be acquired again. During this time, the user continues to adjust the position or orientation of the ultrasound probe 1 in order to properly acquire the second ultrasound image U2.

[0066] Incidentally, in order to confirm whether the second ultrasound image U2, which represents the apical five-chamber or apical three-chamber view, has been properly acquired, it is common to repeat a series of operations: placing a so-called Doppler gate in the left ventricular outflow tract T in the second ultrasound image U2, acquiring the time-varying waveform of blood flow velocity in the left ventricular outflow tract T using the so-called pulsed Doppler method within the Doppler gate, and checking the time-varying waveform. This process can take a considerable amount of time to obtain a proper second ultrasound image U2. By confirming the consistency reported in step S6, the user can easily determine whether the second ultrasound image U2 has been properly acquired and accurately visualize the second ultrasound image U2.

[0067] If it is determined in step S7 that the second ultrasound image U2 should not be reacquired, the process proceeds to step S8. In step S8, the velocity-time integral value calculation unit 30 calculates the velocity-time integral value of blood flow within the Doppler gate set in the left ventricular outflow tract T visible in the second ultrasound image U2, and the cardiac output calculation unit 31 calculates the cardiac output using the velocity-time integral value. The user can appropriately acquire the second ultrasound image U2 by confirming the consistency calculated in step S6, and can accurately calculate the cardiac output using the appropriately acquired second ultrasound image U2.

[0068] Once the process in step S8 is completed, the operation of the ultrasound diagnostic device according to the flowchart shown in Figure 9 is complete.

[0069] As described above, according to the ultrasound diagnostic apparatus of the embodiment of the present invention, the consistency calculation unit 28 calculates the consistency between the first ultrasound image U1 and the second ultrasound image U2 by comparing the first measurement value acquired by the first measurement unit 26 and the second measurement value acquired by the second measurement unit 27 with each other, and the notification unit 29 notifies the user of the consistency calculated by the consistency calculation unit 28, so that the first ultrasound image U1 and the second ultrasound image U2 that are consistent with each other can be accurately depicted.

[0070] Although it is explained that the transmitting / receiving circuit 12 is provided in the ultrasonic probe 1, the transmitting / receiving circuit 12 may also be provided in the main body of the device 2. Furthermore, although it is explained that the image generation unit 21 is provided in the main body 2 of the device, the image generation unit 21 may also be provided in the ultrasonic probe 1.

[0071] The main unit 2 of the device may be a stationary type, a portable type that is easy to carry, or a handheld type, for example, composed of a smartphone or tablet computer. Thus, the type of equipment that makes up the main unit 2 is not particularly limited.

[0072] Although an example is described in which the notification unit 29 notifies the user by displaying information on the monitor 23, the method of notification by the notification unit 29 is not particularly limited to this. For example, as shown in Figure 10, if the ultrasound diagnostic device is equipped with a speaker 61, the notification unit 29 can also output the consistency calculated by the consistency calculation unit 28 as sound from the speaker 61.

[0073] Furthermore, as shown in Figure 11, for example, the ultrasound diagnostic device may also be equipped with a warning lamp 62. The notification unit 29 can illuminate the warning lamp 62 when the consistency calculated by the consistency calculation unit 28 falls below a defined consistency threshold. The warning lamp 62 can be provided on the device body 2 as shown in Figure 11, but it can also be provided on the ultrasound probe 1, and can be installed independently of the ultrasound probe 1 and the device body 2.

[0074] Furthermore, the ultrasound diagnostic device may also include an ultrasound probe 1A with a built-in vibrator 63, as shown in Figure 12, for example. In this case, when the ultrasound probe 1A is equipped with a vibrator 63, the notification unit 29 can vibrate the vibrator 63 if the consistency calculated by the consistency calculation unit 28 falls below a predetermined consistency threshold. The vibrator 63 can be made up of a so-called vibration motor or the like.

[0075] The image acquisition unit 34 determines whether the first ultrasound image U1 or the second ultrasound image U2 has been acquired based on the recognition result of the image recognition unit 25. However, the user can also input information on which of the first ultrasound image U1 or the second ultrasound image U2 to acquire via the input device 33. In this case, the first measurement unit 26 and the second measurement unit 27 can refer to the information input by the user to decide whether or not to perform processing.

[0076] Incidentally, if the so-called papillary muscles are visible in the second ultrasound image U2, which represents the five-chamber view of the apex of the heart, it can be determined that the second ultrasound image U2 is not being properly visualized. Therefore, the image recognition unit 25 processes the second ultrasound image U2 to recognize the papillary muscles using a template matching method or a method using a trained model in machine learning, and the notification unit 29 can notify the user that the second ultrasound image U2 is not being properly visualized when the image recognition unit 25 recognizes the papillary muscles.

[0077] Furthermore, although step S8 explains how to measure cardiac output, depending on the purpose of the test, the process can be stopped after measuring stroke volume, or after calculating the velocity-time integral of blood flow. [Explanation of Symbols]

[0078] 1 Ultrasound probe, 2 Main unit, 11 Transducer array, 12 Transmit / receive circuit, 21 Image generation unit, 22 Display control unit, 23 Monitor, 24 Image memory, 25 Image recognition unit, 26 First measurement unit, 27 Second measurement unit, 28 Consistency calculation unit, 29 Notification unit, 30 Velocity-time integral value calculation unit, 31 Cardiac output calculation unit, 32 Device control unit, 33 Input device, 34 Image acquisition unit, 35 Processor, 41 Pulsar, 42 Amplifier unit, 43 AD conversion unit, 44 Beamformer, 45 Signal processing unit, 46 DSC, 47 Image processing unit, 51 Gate setting unit, 52 Quadrature detection unit, 53 High-pass filter, 54 Fast Fourier Transform unit, 55 Doppler waveform acquisition unit, 56 Integral value calculation unit, 61 Speaker, 62 Warning lamp, 63 Vibrator, M Message, ML1, ML2 Measurement line, T Left ventricular outflow tract, U1: First ultrasound image, U2: Second ultrasound image.

Claims

1. An image acquisition unit acquires first and second ultrasound images, respectively, of a first and second cross-section of the subject's heart, A first measurement unit that acquires a first measurement value of a defined measurement target depicted in the first cross-section from the first ultrasonic image, A second measurement unit that acquires a second measurement value of the defined measurement target depicted in the second cross-section from the second ultrasound image, A consistency calculation unit calculates the consistency between the first ultrasound image and the second ultrasound image by comparing the first measurement value obtained by the first measurement unit and the second measurement value obtained by the second measurement unit with each other. A notification unit that notifies the user of the consistency calculated by the consistency calculation unit. An ultrasound diagnostic device equipped with the following features.

2. The image acquisition unit acquires a first ultrasound image with the parasternal left ventricle long axis section as the first cross-section and a second ultrasound image with the apical five-chamber section or the apical three-chamber section as the second cross-section. The ultrasound diagnostic apparatus according to claim 1, wherein the first measured value and the second measured value measure the left ventricular outflow tract diameter as the first measured value and the second measured value, respectively.

3. The ultrasound diagnostic apparatus according to claim 2, wherein the consistency calculation unit calculates the difference or ratio between the first measured value and the second measured value as the consistency.

4. Equipped with a monitor, The ultrasonic diagnostic apparatus according to claim 1, wherein the notification unit displays the consistency calculated by the consistency calculation unit on the monitor.

5. Equipped with a speaker, The ultrasonic diagnostic apparatus according to claim 1, wherein the notification unit outputs the consistency calculated by the consistency calculation unit as sound from the speaker.

6. Equipped with a warning light, The ultrasonic diagnostic apparatus according to claim 1, wherein the notification unit illuminates the warning lamp when the consistency calculated by the consistency calculation unit falls below a predetermined threshold.

7. Equipped with an ultrasound probe, The aforementioned ultrasonic probe has a built-in vibrator, The ultrasonic diagnostic apparatus according to claim 1, wherein the notification unit vibrates the vibrator when the consistency calculated by the consistency calculation unit falls below a predetermined threshold.

8. A velocity-time integral value calculation unit calculates the velocity-time integral value of left ventricular outflow tract blood flow from the second ultrasound image, A cardiac output calculation unit calculates cardiac output based on the left ventricular outflow tract diameter as the first measured value obtained by the first measurement unit and the velocity-time integral value calculated by the velocity-time integral value calculation unit. Equipped with, The ultrasound diagnostic apparatus according to claim 2, wherein the notification unit notifies the user if the cardiac output calculated by the cardiac output calculation unit deviates from a predetermined value.

9. First and second ultrasound images are obtained, each capturing a different first and second cross-section of the subject's heart. From the first ultrasound image, a first measurement value of a defined measurement target depicted in the first cross-section is obtained. The second measurement value of the defined measurement target depicted in the second cross-section is obtained from the second ultrasound image. By comparing the acquired first measurement value and the second measurement value with each other, the consistency between the first ultrasound image and the second ultrasound image is calculated. The user is notified of the calculated consistency. A method for controlling an ultrasound diagnostic device.

Images