Ultrasound diagnostic device and control method for ultrasound diagnostic device

Abstract

The present invention provides an ultrasound diagnostic device and a control method for the ultrasound diagnostic device that can quickly and easily calculate the ejection fraction of the cardiac lumen. [Solution] The ultrasound diagnostic device includes an image acquisition unit (33) that acquires a first ultrasound image of a first cross-section of the heart and a second ultrasound image of a second cross-section of the heart; a cross-sectional area calculation unit (24) that calculates the cross-sectional area of ​​the lumen of the heart based on the first ultrasound image and the second ultrasound image; a cross-sectional area change curve generation unit (25) that generates a first cross-sectional area change curve for the first cross-section and a second cross-sectional area change curve for the second cross-section; a positioning unit (26) that aligns the first cross-sectional area change curve and the second cross-sectional area change curve with respect to each other; and a frame update unit (29) that automatically updates the other frame when one of the frames of the first ultrasound image and the second ultrasound image is updated based on user instructions.

Description

Technical Field

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

Background Art

[0002] Conventionally, an ultrasonic image representing a tomographic plane of a subject's heart has been captured using a so-called ultrasonic diagnostic apparatus, and using this ultrasonic image, the ejection fraction of the inner cavity of the heart, such as the so-called left ventricular ejection fraction (LVEF: Left Ventricular Ejection Fraction), has been calculated. When calculating the ejection fraction of the inner cavity of the heart, ultrasonic images representing the states of the heart at the end of systole and the end of diastole in a so-called apical two-chamber cross-section and ultrasonic images representing the states of the heart at the end of systole and the end of diastole in a so-called apical four-chamber cross-section are often used.

[0003] In order to easily obtain such ultrasonic images suitable for calculating the ejection fraction of the inner cavity of the heart, for example, an ultrasonic diagnostic apparatus as disclosed in Patent Document 1 has been developed. The ultrasonic diagnostic apparatus of Patent Document 1 divides the period corresponding to one heartbeat into a systolic period and a diastolic period of the heart, and in each of the systolic period and the diastolic period of the heart, the phases of a plurality of frames of ultrasonic images representing an apical two-chamber cross-section and a plurality of frames of ultrasonic images representing an apical four-chamber cross-section are matched, and two types of ultrasonic images with matched phases are simultaneously displayed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, in order to obtain an ultrasound image suitable for the ejection fraction of the cardiac lumen, a user may compare multiple frames of ultrasound images and select the appropriate image from among them. In this case, the user usually searches for an ultrasound image suitable for calculating the ejection fraction by updating the ultrasound images representing the apical two-chamber section and the ultrasound images representing the apical four-chamber section displayed on the monitor, respectively. However, Patent Document 1 does not take into account such updating of ultrasound images by the user, and there was room for improvement in order to shorten the time required to calculate the ejection fraction.

[0006] This invention was made to solve the problems of the conventional methods, and aims to provide an ultrasound diagnostic device and a control method for the ultrasound diagnostic device that can calculate the ejection fraction of the cardiac lumen quickly and easily. [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 consisting of multiple frames that are sequentially continuous and capture a first cross-section of the subject's heart, and a second ultrasound image consisting of multiple frames that are sequentially continuous and capture a second cross-section of the heart different from the first cross-section, A cross-sectional area calculation unit calculates the cross-sectional area of ​​the cardiac lumen for each frame of a first ultrasound image consisting of multiple frames and a second ultrasound image consisting of multiple frames. A cross-sectional area change curve generation unit generates a first cross-sectional area change curve for the first cross-section and a second cross-sectional area change curve for the second cross-section, respectively, which represent the temporal change in the cross-sectional area, based on the cross-sectional area calculated by the cross-sectional area calculation unit. A positioning unit that aligns the first cross-sectional area change curve and the second cross-sectional area change curve generated by the cross-sectional area change curve generation unit with each other, A monitor that displays the first and second ultrasound images at corresponding points on the first and second cross-sectional area change curves, respectively. A frame update unit automatically updates the other frame of the first and second ultrasound images in response to the update of one of the frames of the first and second ultrasound images displayed on the monitor, based on user instructions. An ultrasound diagnostic device equipped with the following features. [2] The alignment part is, A curve selection unit that selects the first and second curve portions containing the same number of change cycles for the first and second cross-sectional area change curves, respectively. A normalization unit that normalizes the first curve portion and the second curve portion, The ultrasound diagnostic apparatus according to [1], having a partial alignment unit that aligns the first curve portion and the second curve portion, which have been normalized by the normalization unit, with respect to each other. [3] The ultrasound diagnostic apparatus according to [2], wherein the curve selection unit selects the first curve portion and the second curve portion based on the interval selected by the user in the first cross-sectional area change curve and the second cross-sectional area change curve. [4] The curve selection section is, Based on the interval selected by the user for either the first or second cross-sectional area change curve, the system selects either the first or second curve portion. Calculate the number of change cycles included in either the first or second curve segment. The ultrasound diagnostic apparatus according to [2], which selects the other of the first curve portion and the second curve portion based on the calculated number of change cycles. [5] The ultrasound diagnostic apparatus according to [2], wherein the curve selection unit selects a first curve portion and a second curve portion that include the same number of change cycles as the specified number of cycles specified by the user. [6] The ultrasound diagnostic apparatus according to [2], wherein the normalization unit normalizes the first curve portion and the second curve portion by their respective maximum values. [7] The alignment part is, A normalization unit that normalizes the first cross-sectional area change curve and the second cross-sectional area change curve, A similarity portion identification unit identifies the first curve portion and the second curve portion, which are the parts that are most similar to each other among the first and second cross-sectional area change curves and the second cross-sectional area change curves that have been normalized by the normalization unit, The ultrasound diagnostic apparatus according to [1], having a partial alignment section for aligning the identified first curved portion and the second curved portion with respect to each other. [8] The ultrasound diagnostic apparatus according to [7], wherein the normalization unit normalizes the first cross-sectional area change curve and the second cross-sectional area change curve by their respective maximum values. [9] The ultrasound diagnostic apparatus according to [7], wherein the normalization unit normalizes the first cross-sectional area change curve and the second cross-sectional area change curve using their respective mean and standard deviations.

[10] An ultrasound diagnostic apparatus according to any one of [1] to [9], comprising a frame selection unit that selects a set of first ultrasound images corresponding to the maximum and minimum values ​​in the first cross-sectional area change curve as a first measurement frame group, and a set of second ultrasound images corresponding to the maximum and minimum values ​​in the second cross-sectional area change curve, which have been aligned to the maximum and minimum values ​​in the first cross-sectional area change curve by an alignment unit, as a second measurement frame group.

[11] The monitor displays the first ultrasound image of the first measurement frame group and the second ultrasound image of the second measurement frame group selected by the frame selection unit. The ultrasound diagnostic apparatus according to

[10] , wherein the frame update unit updates the other frame of the first ultrasound image and the second ultrasound image in correspondence with the updated frame when one of the frames of the first ultrasound image and the second ultrasound image displayed on the monitor is updated.

[12] Obtain a series of first ultrasound images consisting of multiple frames that are sequentially continuous and capture a first cross-section of the subject's heart, and a series of second ultrasound images consisting of multiple frames that are sequentially continuous and capture a second cross-section of the heart different from the first cross-section. For each frame of the first ultrasound image and the second ultrasound image, which consist of multiple frames, the cross-sectional area of ​​the cardiac lumen is calculated. Based on the calculated cross-sectional area, a first cross-sectional area change curve for the first cross-section and a second cross-sectional area change curve for the second cross-section are generated, representing the temporal change in the cross-sectional area. Align the first cross-sectional area change curve and the second cross-sectional area change curve with each other. The first and second ultrasound images are displayed at corresponding points on the first and second cross-sectional area change curves, respectively. When one of the displayed first or second ultrasound images is updated based on user instructions, the other frame of the first or second ultrasound image is automatically updated in response to the updated frame. A method for controlling an ultrasound diagnostic device. [Effects of the Invention]

[0008] The present invention relates to an ultrasound diagnostic apparatus comprising: an image acquisition unit that acquires a plurality of frames of first ultrasound images that are sequentially time-series and capture a first cross-section of the heart of a subject, and a plurality of frames of second ultrasound images that are sequentially time-series and capture a second cross-section of the heart different from the first cross-section; a cross-sectional area calculation unit that calculates the cross-sectional area of ​​the lumen of the heart for each frame of the plurality of frames of first ultrasound images and plurality of frames of second ultrasound images; and a cross-sectional area change curve generation unit that generates a first cross-sectional area change curve for the first cross-section and a second cross-sectional area change curve for the second cross-section, respectively, which represent the temporal change in the cross-sectional area based on the cross-sectional area calculated by the cross-sectional area calculation unit. The system includes an alignment unit that aligns the first cross-sectional area change curve and the second cross-sectional area change curve generated by the cross-sectional area change curve generation unit with each other, a monitor that displays the first and second ultrasound images at corresponding points on the first and second cross-sectional area change curves, and a frame update unit that updates the other frame of the first and second ultrasound images in accordance with the updated frame when one of the frames of the first and second ultrasound images displayed on the monitor is updated based on user instructions. As a result, the ejection fraction of the cardiac lumen can be calculated quickly and easily. [Brief explanation of the drawing]

[0009] [Figure 1] This is a block diagram showing the configuration of an ultrasound diagnostic device according to Embodiment 1 of the present invention. [Figure 2]It is a block diagram showing the internal configuration of the transmission / reception circuit in Embodiment 1 of the present invention. [Figure 3] It is a block diagram showing the internal configuration of the image generation unit in Embodiment 1 of the present invention. [Figure 4] It is a diagram schematically showing an example of a first ultrasonic image representing a four-chamber cross-section of the apex of the heart. [Figure 5] It is a diagram schematically showing an example of a second ultrasonic image representing a two-chamber cross-section of the apex of the heart. [Figure 6] It is a diagram schematically showing an example of a first cross-sectional area change curve representing the temporal change of the cross-sectional area of the heart lumen in a plurality of frames of the first ultrasonic image. [Figure 7] It is a diagram schematically showing an example of a second cross-sectional area change curve representing the temporal change of the cross-sectional area of the heart lumen in a plurality of frames of the second ultrasonic image. [Figure 8] It is a block diagram showing the internal configuration of the alignment unit in Embodiment 1 of the present invention. [Figure 9] It is a diagram showing a first curve portion selected from the first cross-sectional area change curve and a second curve portion selected from the second cross-sectional area change curve. [Figure 10] It is a diagram schematically showing a two-dimensional array of the values of each point on the first curve and the values of each point on the second curve in Embodiment 1. [Figure 11] It is a diagram schematically showing a display example of the first ultrasonic image, the second ultrasonic image, the first cross-sectional area change curve, and the second cross-sectional area change curve. L [Figure 12] It is a flowchart showing the operation of the ultrasonic diagnostic apparatus according to Embodiment 1 of the present invention. [Figure 13] It is a flowchart showing the alignment process in Embodiment 1 of the present invention. [Figure 14] It is a block diagram showing the configuration of the ultrasonic diagnostic apparatus according to Embodiment 2 of the present invention. [Figure 15] It is a block diagram showing the internal configuration of the alignment unit in Embodiment 2 of the present invention. [Figure 16]This figure shows the similar portion of the first cross-sectional area change curve and the second cross-sectional area change curve, which is similar to the first cross-sectional area change curve. [Figure 17] This figure schematically shows a two-dimensional array of the values ​​of each point on the first curve and the values ​​of each point on the second curve in Embodiment 2. [Figure 18] This is a flowchart showing the alignment process in Embodiment 2 of the present invention. [Modes for carrying out the invention]

[0010] Embodiments of this invention will be described below with reference to the attached drawings. The following description of the constituent elements is based on a typical embodiment of the present invention, but the present invention is not limited to such embodiments. In this specification, a numerical range represented by "~" means a range that includes the numbers written before and after "~" as the lower and upper limits, respectively. In this specification, “identical” and “same” include a margin of error that is generally accepted in the art.

[0011] Embodiment 1 Figure 1 shows the configuration of an ultrasound diagnostic apparatus according to Embodiment 1 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. A cross-sectional area calculation unit 24 is also connected to the image generation unit 21. A cross-sectional area change curve generation unit 25 and a positioning unit 26 are sequentially connected to the cross-sectional area calculation unit 24. A memory 27 is connected to the positioning unit 26. A frame selection unit 28 is connected to the memory 27. A frame update unit 29 is connected to both the memory 27 and the frame selection unit 28. A measurement unit 30 is connected to both the frame selection unit 28 and the frame update unit 29. The memory 27, frame selection unit 28, frame update unit 29, and measurement unit 30 are each connected to the display control unit 22. Furthermore, the main control unit 31 is connected to the transmitting / receiving circuit 12, image generation unit 21, display control unit 22, cross-sectional area calculation unit 24, cross-sectional area change curve generation unit 25, alignment unit 26, memory 27, frame selection unit 28, frame update unit 29, and measurement unit 30. An input device 32 is connected to the main control unit 31.

[0014] The image acquisition unit 33 is composed of a transmitting / receiving circuit 12 and an image generation unit 21. Furthermore, the processor 34 for the main body of the device 2 is composed of the image generation unit 21, display control unit 22, cross-sectional area calculation unit 24, cross-sectional area change curve generation unit 25, alignment unit 26, frame selection unit 28, frame update unit 29, measurement unit 30, and main body control unit 31.

[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 33, which consists of a transmitting / receiving circuit 12 and an image generation unit 21, acquires an ultrasound image of the subject 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 main unit control 31. As shown in Figure 2, the transmitting / receiving circuit 12 has 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 according to a control signal from the main unit control 31, 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, and after correcting for attenuation due to distance according to the depth of the ultrasonic reflection position using the sound velocity value set by the main unit control unit 31, it 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 and the cross-sectional area calculation unit 24. Hereafter, the B-mode image signal processed by the image processing unit 47 will be referred to as the ultrasonic image.

[0024] The ultrasound diagnostic apparatus of Embodiment 1 of the present invention is used to calculate the ejection fraction of the cardiac lumen of a subject, such as the so-called left ventricular ejection fraction (LVEF). To calculate the ejection fraction of the cardiac lumen, the image acquisition unit 33 acquires a first ultrasound image U1 consisting of multiple frames representing the so-called apical four-chamber section 4C (first section) of the heart H, as shown in Figure 4, and a second ultrasound image U2 consisting of multiple frames representing the so-called apical two-chamber section 2C (second section) of the heart H.

[0025] The display control unit 22, under the control of the main unit control unit 31, performs predetermined processing on the first ultrasound image U1 and the second ultrasound image U2, etc., generated by the image generation unit 21 and displays them on the monitor 23.

[0026] The monitor 23 displays the first ultrasound image U1 and the second ultrasound image U2, etc., under the control of the display control unit 14, and has a display device such as an LCD (Liquid Crystal Display) or an organic EL display (Organic Electroluminescence Display).

[0027] The cross-sectional area calculation unit 24 calculates the cross-sectional area of ​​the lumen of the heart H for each frame of the first ultrasound image U1 and the second ultrasound image U2, which consist of multiple frames. The cross-sectional area of ​​the lumen of the heart H calculated here refers to the area of ​​the lumen of the heart H on the first ultrasound image U1 and the area of ​​the lumen of the heart H on the second ultrasound image U2, respectively. For example, when the purpose is to calculate the left ventricular ejection fraction, the cross-sectional area calculation unit 24 calculates the cross-sectional area of ​​the lumen of the left ventricle A1 in the first ultrasound image U1, which consists of multiple frames, as shown in Figure 4, and the cross-sectional area of ​​the lumen of the left ventricle A2 in the second ultrasound image U2, which consists of multiple frames, as shown in Figure 5.

[0028] The cross-sectional area calculation unit 24 can output the cross-sectional area of ​​the lumen of the heart H in the first ultrasound image U1 and the cross-sectional area of ​​the lumen of the heart H in the second ultrasound image U2 by inputting the first ultrasound image U1 and the second ultrasound image U2 to a pre-trained model in so-called machine learning, which has learned the relationship between a large number of ultrasound images and the lumen of the heart and its area contained in those ultrasound images.

[0029] Furthermore, the cross-sectional area calculation unit 24 can, for example, pre-store multiple template image data representing the lumen of the heart H, and use these multiple template image data to search within the first ultrasound image U1 and the second ultrasound image U2, using a so-called template matching method to extract the lumen of the heart H from the first ultrasound image U1 and the second ultrasound image U2, respectively, and calculate the cross-sectional area of ​​the extracted lumen of the heart H. In this way, the cross-sectional area calculation unit 24 can use a known algorithm to extract the contour of the lumen of the heart H or the image region occupied by the lumen of the heart H from within the image, and calculate the cross-sectional area of ​​the lumen of the heart H based on the extracted contour of the lumen of the heart H or the image region.

[0030] The cross-sectional area change curve generation unit 25 generates a first cross-sectional area change curve for the apical four-chamber section 4C and a second cross-sectional area change curve for the apical two-chamber section 2C, respectively, based on the cross-sectional area of ​​the lumen of the heart H calculated by the cross-sectional area calculation unit 24. An example of the first cross-sectional area change curve C1 is shown in Figure 6, and an example of the second cross-sectional area change curve C2 is shown in Figure 7. It is known that the cross-sectional area of ​​the lumen of the heart H in the apical four-chamber section 4C and the apical two-chamber section 2C changes periodically over time due to the beating of the heart H. In addition, the heart rate of the subject is not necessarily constant due to diseases such as arrhythmias the subject has, mental or physical stress on the subject, etc., and the imaging conditions for the apical four-chamber section 4C and the apical two-chamber section 2C may also differ. Therefore, the period of change in the cross-sectional area of ​​the lumen of the heart H and the scale of that cross-sectional area may differ between the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2.

[0031] The alignment unit 26 aligns the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2 with each other. Here, the alignment of the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2 refers to associating the maximum value in the first cross-sectional area change curve C1 with the maximum value in the second cross-sectional area change curve C2, the minimum value in the first cross-sectional area change curve C1 with the minimum value in the second cross-sectional area change curve C2, and each point between the maximum value and the minimum value in the first cross-sectional area change curve C1 with each point between the maximum value and the minimum value in the second cross-sectional area change curve C2 with each other.

[0032] As shown in Figure 8, the alignment unit 26 has a configuration in which a curve selection unit 51, a normalization unit 52, and a partial alignment unit 53 are connected in series.

[0033] The curve selection unit 51 selects, for example, as shown in Figure 9, the first curve portion D1 and the second curve portion D2 for the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2, respectively, which contain the same number of change cycles. A change cycle represents the portion corresponding to one period of change in cross-sectional area in the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2, and the endpoints of the period can be set arbitrarily.

[0034] The curve selection unit 51 can, for example, select the first curve portion D1 and the second curve portion D2 in the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2 based on the interval selected by the user via the input device 32. The user can, for example, select the interval in the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2 by so-called drag operation if the input device 32 includes a mouse or touch panel, or select the interval in the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2 by inputting the start and end times of the interval if the input device 32 includes a so-called keyboard.

[0035] Furthermore, the curve selection unit 51 can also select either the first curve portion D1 or the second curve portion D2 based on the section selected by the user for the first cross-sectional area change curve C1 or the second cross-sectional area change curve C2, calculate the number of change cycles included in one of the first curve portion D1 and the second curve portion D2, and select the other of the first curve portion D1 and the second curve portion D2 based on the calculated number of change cycles. For example, if the user selects the first curve portion D1 from the first cross-sectional area change curve C1, which contains three change cycles, the curve selection unit 51 can select the second curve portion D2, which is located in the central part of the second cross-sectional area change curve C2 and contains the same three change cycles as the first curve portion D1. In this case, the position on the second cross-sectional area change curve C2 where the curve selection unit 51 selects the second curve portion D2 can be set in advance, such as the central part or the end.

[0036] Furthermore, the curve selection unit 51 can calculate the number of change cycles included in the entirety of the first cross-sectional area change curve C1 and the entirety of the second cross-sectional area change curve C2, and by referring to the calculated number of change cycles for each, it can also select the first curve section D1 and the second curve section D2 that contain the same number of change cycles as the specified number of cycles specified by the user via the input device 32. In this case, the position on the first cross-sectional area change curve C1 where the curve selection unit 51 selects the first curve section D1, and the position on the second cross-sectional area change curve C2 where it selects the second curve section D2, can be set in advance, such as the central part or the end.

[0037] The normalization unit 52 normalizes the first curve portion D1 and the second curve portion D2, which were selected by the curve selection unit 51, by their respective maximum values. Normalizing the first curve portion D1 by its maximum value means dividing all values ​​in the first curve portion D1 by its maximum value, and normalizing the second curve portion D2 by its maximum value means dividing all values ​​in the second curve portion D2 by its maximum value. Each point on the normalized first curve portion D1 and each point on the normalized second curve portion D2 have a value greater than 0 and less than or equal to 1.

[0038] The partial alignment unit 53 aligns the first curve portion D1 and the second curve portion D2 selected by the curve selection unit 51 with respect to each other. The partial alignment unit 53 can align the first curve portion D1 and the second curve portion D2 with respect to each other using an algorithm such as the so-called DTW (Dynamic Time Warping) method.

[0039] Specifically, the partial alignment unit 53 divides the interval from the start time to the end time of the first curve portion D1 into M parts at regular time intervals, and sets the first matrix X, which represents the normalized value in the first curve portion D1 corresponding to the M divided division times, as shown in equation (1). Here, M is a positive integer of 2 or more, but it is preferable to set it to the largest possible number in order to perform accurate alignment.

number

[0040] Furthermore, the partial alignment unit 53 divides the interval from the start time to the end time of the second curve section D2 into N parts using the same time intervals as those used to divide the interval from the start time to the end time of the second curve section D2, and sets a second matrix Y representing the normalized values ​​in the second curve section D2 corresponding to the N divided times as shown in equation (2). Here, N is a positive integer of 2 or more, but it is preferable to set it to the largest possible number in order to perform accurate alignment.

number

[0041] The partial alignment unit 53 sets the difference matrix D, which represents the difference in all combinations of each element of the first matrix X and each element of the second matrix Y, as shown in equation (3).

number

[0042] The partial alignment unit 53 uses an algorithm such as so-called dynamic programming to calculate the minimum path B1 among multiple paths B from |X1-Y1| to |XM-YN| in multiple elements of the difference matrix D, which is continuous and does not backtrack toward |X1-Y1|, and for which the sum of all elements on the path is minimized, as schematically shown in Figure 10. Figure 10 is a schematic diagram showing a two-dimensional array of each element of X represented by equation (1) and each element of Y represented by equation (2), corresponding to the difference matrix D represented by equation (3). The points (XL, YK) on this two-dimensional array correspond to the element |XL-YK| in the difference matrix D. Here, L is an integer between 1 and M, and K is an integer between 1 and N.

[0043] The partial alignment unit 53 aligns the points corresponding to M division times on the first curve portion D1 with the points corresponding to M of the N division times on the second curve portion D2, as shown in Figure 9, by associating XL and YK, which are used to calculate the difference, in each element |XL-YK| on the minimum path B1 in the difference matrix D. Note that the points corresponding to M division times on the second curve portion D2 include the point corresponding to element Y1 and the point corresponding to element YN of the second matrix Y.

[0044] The memory 27 stores the first curved portion D1 and the second curved portion D2, which have been aligned by the alignment unit 26, under the control of the main unit control unit 31. The memory 27 also reads the stored first curved portion D1 and the second curved portion D2, under the control of the main unit control unit 31, and sends them to the display control unit 22, the frame selection unit 28, and the frame update unit 29.

[0045] For memory 27, for example, 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.

[0046] As shown in Figure 9, the frame selection unit 28 selects a set of first ultrasound images U1 corresponding to the maximum value Q1 and minimum value R1 in the first curve portion D1 of the first cross-sectional area change curve C1 as the first measurement frame group. The frame selection unit 28 also selects a set of second ultrasound images U2 corresponding to the maximum value Q2 and minimum value R2 in the second cross-sectional area change curve C2, which has been aligned with the maximum value Q1 and minimum value R1 in the first cross-sectional area change curve C1 by the alignment unit 26, as the second measurement frame group.

[0047] The frame selection unit 28 can select a first group of frames for the first curved portion D1 based on instructions from the user, for example, via the input device 32. The frame selection unit 28 can automatically select a second group of frames corresponding to the first group of frames selected based on the user's instructions, based on the correspondence between the first curved portion D1 and the second curved portion D2 determined by the alignment unit 26.

[0048] Furthermore, the frame selection unit 28 automatically extracts multiple local maximums Q1 and multiple local minimums R1 in the first curve portion D1, and can select one set of local maximums Q1 and R1 from the extracted set of local maximums Q1 and R1. In this case, the frame selection unit 28 can, for example, select the largest local maximum Q1 from the multiple local maximums Q1 and the smallest local minimum R1 from the multiple local minimums R1.

[0049] As shown in Figure 11, the monitor 23 can display the first ultrasound image U1 and the second ultrasound image U2 at corresponding points P1 and P2 on the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2, respectively, for example, the first ultrasound image U1 of the first frame group and the second ultrasound image U2 of the second frame group selected by the frame selection unit 28. In the example in Figure 11, the first cross-sectional area change curve C1, the first curve portion D1, point P1 on the first curve portion D1, the second cross-sectional area change curve C2, the second curve portion D2, point P2 on the second curve portion D2, the first ultrasound image U1, and the second ultrasound image U2 are displayed on the monitor 23.

[0050] When one of the frames of the first ultrasound image U1 and the second ultrasound image U2 displayed on the monitor 23 is updated based on user instructions, the frame update unit 29 updates the other frame of the first ultrasound image U1 and the second ultrasound image U2 in accordance with the one frame by referring to the correspondence between the first curve portion D1 and the second curve portion D2 that have been aligned by the alignment unit 26.

[0051] The user can, for example, check the first ultrasound image U1 of the first frame group and the second ultrasound image U2 of the second frame group, which have been selected by the frame selection unit 28 and displayed on the monitor 23. If the user determines that the first ultrasound image U1 of the first frame group and the second ultrasound image U2 of the second frame group are not suitable for calculating the ejection fraction of the lumen of the heart H, the user can issue an instruction to update one of the frames from the first ultrasound image U1 of the first frame group and the second ultrasound image U2 of the second frame group, for example, by updating to the first ultrasound image U1 from the previous frame. In this case, the frame update unit 29 automatically updates the second ultrasound image U2 that was displayed on the monitor 23 to the second ultrasound image U2 corresponding to the updated first ultrasound image U1.

[0052] In this way, by simply instructing the user to update either the first ultrasound image U1 or the second ultrasound image U2, the other is automatically updated as well. Therefore, the user can quickly and easily find both the first ultrasound image U1 and the second ultrasound image U2 that are suitable for measuring the ejection fraction of the cardiac lumen H.

[0053] The measurement unit 30 calculates the ejection fraction of the lumen of the heart H, such as the left ventricular ejection fraction, from the cross-sectional area of ​​the lumen of the heart H corresponding to the first frame group and the second frame group selected by the frame selection unit 28, or from the cross-sectional area of ​​the lumen of the heart H corresponding to the first frame group and the second frame group updated by the frame update unit 29 in accordance with user instructions. The measurement unit 30 calculates the ejection fraction of the lumen of the heart H from the cross-sectional area of ​​the lumen of the heart H corresponding to the first frame group and the second frame group selected by the frame selection unit 28 when the first frame group and the second frame group are not updated by the frame update unit 29, and calculates the ejection fraction of the lumen of the heart H from the cross-sectional area of ​​the lumen of the heart H corresponding to the first frame group and the second frame group updated by the frame update unit 29 when the first frame group and the second frame group are updated by the frame update unit 29. Although not shown in the diagram, the ejection fraction value of the lumen of the heart H measured by the measurement unit 30 can be displayed on the monitor 23 together with the first cross-sectional area change curve C1, the second cross-sectional area change curve C2, the first ultrasound image U1, and the second ultrasound image U2.

[0054] The main unit control unit 31 controls each part of the main unit 2 and the transmitting / receiving circuit 12 of the ultrasonic probe 1 based on a control program or the like that is stored in advance.

[0055] The input device 32 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.

[0056] The processor 34, which includes an image generation unit 21, a display control unit 22, a cross-sectional area calculation unit 24, a cross-sectional area change curve generation unit 25, a positioning unit 26, a frame selection unit 28, a frame update unit 29, a measurement unit 30, and a main unit control unit 31, may be composed of one or more hardware components, and the type of hardware is not limited. For example, the processor can be composed of hardware such as a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a programmable logic device such as an FPGA (Field Programmable Gate Array), a dedicated circuit for executing specific processing such as an ASIC (Application Specific Integrated Circuit), a GPU (Graphic Processing Unit), or an NPU (Neural Processing Unit). The processor also has various units or means that execute the various processes in this embodiment. 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 certain processor, these multiple hardware components may reside in physically separate devices or in the same device. Furthermore, in any embodiment, the order of each process performed by the processor is not limited to the order described above and may be changed as appropriate. The hardware is composed of electrical circuits and the like, which are made up of circuit elements such as semiconductor elements.

[0057] Furthermore, this embodiment may be implemented by hardware, software, firmware, microcode, or a combination thereof. The software, firmware, and microcode are composed of a program. The program may also be, for example, a group of program modules, each 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 devices that are physically separated from each other. The program code or code segment may represent any combination of procedures, functions, subprograms, routines, subroutines, modules, software packages, classes, or instructions, data structures, or program statements. The program code or code segment may be connected to other code segments or hardware circuits by sending and receiving information, data, arguments, parameters, or memory contents.

[0058] Next, the operation of the ultrasound diagnostic apparatus according to Embodiment 1 will be described with reference to the flowchart shown in Figure 12.

[0059] In step S1, the image acquisition unit 33 generates a first ultrasound image U1 representing the four-chamber cross-section 4C of the cardiac apex. At this time, under the control of the main unit control unit 31, the transmission and reception of ultrasound is started from multiple transducers of the transducer array 11 according to the drive signal from the pulser 41 of the transmitting and receiving circuit 12 of the ultrasound probe 1. The ultrasound echo from within the subject is 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 the received data is acquired by AD conversion in the AD conversion unit 43.

[0060] The beamformer 44 performs reception focus processing on this received data, and the resulting sound ray signal is sent to the image generation unit 21 of the device body 2, where the image generation unit 21 generates a first ultrasound image U1 representing the four-chamber cross-section 4C of the cardiac apex. At this time, the signal processing unit 45 of the image generation unit 21 performs attenuation correction according to the depth of the ultrasound reflection position and envelope detection processing on the sound ray signal, and the DSC 46 converts it into an image signal following 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 ultrasound image U1 generated in step S1 in this way is displayed on the monitor 23 via the display control unit 22 and sent to the cross-sectional area calculation unit 24.

[0061] In step S2, the cross-sectional area calculation unit 24 calculates the cross-sectional area of ​​the lumen of the heart H as seen in the first ultrasound image U1 by performing image analysis on the first ultrasound image U1 acquired in step S1. The cross-sectional area calculation unit 24 can calculate the cross-sectional area of ​​the lumen of the heart H by, for example, using a trained model in machine learning that has learned the relationship between a large number of first ultrasound images U1 and the cross-sectional areas of the lumen of the heart H seen therein.

[0062] In step S3, the cross-sectional area change curve generation unit 25 generates a first cross-sectional area change curve C1 by plotting the cross-sectional area values ​​calculated in step S2 along the time axis.

[0063] In step S4, the main unit control unit 31 determines whether or not to terminate the acquisition of the first ultrasound image U1. The main unit control unit 31 can determine to terminate the acquisition of the first ultrasound image U1 if, for example, the user inputs an instruction to terminate the acquisition of the first ultrasound image U1 via the input device 32, and to continue acquiring the first ultrasound image U1 if the user does not give any specific instruction via the input device 32.

[0064] If the main control unit 31 determines in step S4 to continue acquiring the first ultrasound image U1, the process returns to step S1, and a new frame of the first ultrasound image U1 is acquired. In step S2, the cross-sectional area of ​​the lumen of the heart H in the first ultrasound image U1 is calculated, and the newly calculated cross-sectional area value in step S3 is plotted along the time axis on the first cross-sectional area change curve C1 generated in the previous step S3, thereby updating the first cross-sectional area change curve C1. In this way, the processing from steps S1 to S4 is repeated, and a first cross-sectional area change curve C1 containing multiple change cycles, as shown in Figure 6, is obtained.

[0065] If it is determined in step S4 that the acquisition of the first ultrasound image U1 is complete, the process proceeds to step S5. In order to acquire the second ultrasound image U2, which represents the apical two-chamber section 2C, the user rotates the ultrasound probe 1 90 degrees around the axis in which it is pressed against the subject, while keeping the ultrasound probe 1 fixed in its current position on the subject's body surface.

[0066] In step S5, the image acquisition unit 33 acquires a second ultrasound image U2 representing a two-chamber view 2C of the apical region in the same manner as the first ultrasound image U1 representing a four-chamber view 4C of the apical region acquired in step S1.

[0067] In step S6, the cross-sectional area calculation unit 24 calculates the cross-sectional area of ​​the lumen of the heart H as seen in the second ultrasound image U2 acquired in step S5, in the same manner as the method used to calculate the cross-sectional area of ​​the lumen of the heart H as seen in the first ultrasound image U1 in step S2.

[0068] In step S7, the cross-sectional area change curve generation unit 25 generates a second cross-sectional area change curve C2 by plotting the cross-sectional area values ​​calculated in step S6 along the time axis.

[0069] In step S8, the main unit control unit 31 determines whether or not to terminate the acquisition of the second ultrasound image U2 in the same manner as the method used to determine whether or not to terminate the acquisition of the first ultrasound image U1 in step S4.

[0070] If the main control unit 31 determines in step S8 to continue acquiring the second ultrasound image U2, the process returns to step S5, and a new frame of the second ultrasound image U2 is acquired. In step S6, the cross-sectional area of ​​the lumen of the heart H in the second ultrasound image U2 is calculated, and the newly calculated cross-sectional area value in step S7 is plotted along the time axis on the second cross-sectional area change curve C2 generated in the previous step S7, thereby updating the second cross-sectional area change curve C2. In this way, the process from steps S5 to S8 is repeated, resulting in a second cross-sectional area change curve C2 that includes multiple change cycles as shown in Figure 7.

[0071] If it is determined in step S8 that the acquisition of the second ultrasound image U2 has been completed, proceed to step S9.

[0072] In step S9, the alignment unit 26 aligns the first cross-sectional area change curve C1 generated in the final step S3 with the second cross-sectional area change curve C2 generated in the final step S7. Step S9 will be explained in detail using the flowchart in Figure 13. As shown in this figure, the process in step S9 consists of the processes in steps S21 to S23.

[0073] In step S21, the curve selection unit 51 of the alignment unit 26 selects, for example, as shown in Figure 9, a first curve portion D1 and a second curve portion D2 from the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2 that contain the same number of change cycles. At this time, the curve selection unit 51 can select a first curve portion D1 corresponding to a section in the first cross-sectional area change curve C1 specified by the user via the input device 32, and a second curve portion D2 corresponding to a section in the second cross-sectional area change curve C2 specified by the user.

[0074] In step S22, the normalization unit 52 of the alignment unit 26 normalizes the first curve portion D1 and the second curve portion D2 selected in step S21 by their respective maximum values.

[0075] In step S23, the partial alignment unit 53 of the alignment unit 26 aligns the first curve portion D1 and the second curve portion D2, which were normalized in step S22, with each other using an algorithm such as DTW. The alignment process in step S9 is completed when the process in step S23 is performed in this manner. Steps S21 to S23 allow for accurate alignment of the first curve portion D1 and the second curve portion D2 by applying an algorithm such as DTW to the first curve portion D1 and the second curve portion D2, which each contain the same number of change cycles and have been normalized.

[0076] In the subsequent step S10, the frame selection unit 28 selects a first frame group from multiple frames of first ultrasound images U1, consisting of a first ultrasound image U1 corresponding to the maximum value Q1 in the first curve portion D1 and a first ultrasound image U1 corresponding to the minimum value R1. The frame selection unit 28 can, for example, select a frame specified by the user via the input device 32 as the first ultrasound image U1 of the first frame group.

[0077] In step S11, the frame selection unit 28 automatically selects the second ultrasound image U2 of the second frame group that corresponds to the first ultrasound image U1 of the first frame group selected in step S10, by referring to the correspondence between the first curve portion D1 and the second curve portion D2 that were aligned with each other in step S9, in order to obtain a second ultrasound image U2 of the frame suitable for calculating the ejection fraction of the lumen of the heart H. Here, the second ultrasound image U2 of the second frame group refers to the second ultrasound image U2 corresponding to the maximum value Q2 and the second ultrasound image U2 corresponding to the minimum value R2 in the second curve portion D2.

[0078] In this way, the first ultrasound image U1 of the first frame group and the second ultrasound image U2 of the second frame group selected in steps S10 and S11 are displayed on the monitor 23 together with the first cross-sectional area change curve C1, a point P1 on the first cross-sectional area change curve C1 corresponding to the first ultrasound image U1 of the first frame group, the second cross-sectional area change curve C2, and a point P2 on the second cross-sectional area change curve C2 corresponding to the second ultrasound image U2 of the second frame group, as shown in Figure 11, for example.

[0079] In step S12, the frame update unit 29 determines whether or not to update the frames of the first ultrasound image U1 of the first frame group and the second ultrasound image U2 of the second frame group selected in steps S10 and S11. The frame update unit 29 can determine to update the frames of the first ultrasound image U1 of the first frame group and the second ultrasound image U2 of the second frame group if the user inputs an instruction to update the frames of the first ultrasound image U1 of the first frame group and the second ultrasound image U2 of the second frame group via the input device 32, for example, if the user determines that it is necessary to update the first ultrasound image U1 and the second ultrasound image U2 selected in steps S10 and S11 in order to accurately calculate the ejection fraction of the lumen of the heart H. Furthermore, the frame update unit 29 can determine, for example, whether to update the frames of the first ultrasound image U1 in the first frame group and the second ultrasound image U2 in the second frame group if the user does not provide any specific instructions on whether or not to update them.

[0080] If it is determined in step S12 that the frames of the first ultrasound image U1 in the first frame group and the second ultrasound image U2 in the second frame group should be updated, the process proceeds to step S13.

[0081] In step S13, the frame update unit 29 selects a first ultrasound image U1 from the first frame group based on the user's instructions. At this time, the frame update unit 29 selects a first ultrasound image U1 from among multiple frames, which is specified by the user via the input device 32, for example, a first ultrasound image U1 in a frame adjacent to the first ultrasound image U1 selected in step S10.

[0082] When the first ultrasound image U1 is manually selected by the user in this manner, the first ultrasound image U1 in the first frame group selected in step S10 is updated to the first ultrasound image U1 selected in step S13. As a result, the first ultrasound image U1 displayed on monitor 23 is also updated to the first ultrasound image U1 selected in step S13.

[0083] In step S14, the frame update unit 29 automatically selects a second ultrasound image U2 that corresponds to the first ultrasound image U1 of the first frame group selected in step S13, by referring to the correspondence between the first curve portion D1 and the second curve portion D2 that were aligned with each other in step S9.

[0084] When the second ultrasound image U2 is automatically selected in this way, the second ultrasound image U2 of the second frame group selected in step S11 is automatically updated to the second ultrasound image U2 selected in step S14. As a result, the second ultrasound image U2 displayed on monitor 23 is also automatically updated to the second ultrasound image U2 selected in step S14.

[0085] In step S15, the frame update unit 29 determines whether or not to terminate the frame update of the first ultrasound image U1 of the first frame group and the second ultrasound image U2 of the second frame group. For example, if the user inputs an instruction to continue updating the frames via the input device 32, the frame update unit 29 can determine to continue updating the frames of the first ultrasound image U1 of the first frame group and the second ultrasound image U2 of the second frame group, and if the user inputs an instruction to terminate the frame update via the input device 32, the frame update unit 29 can determine to terminate the frame update of the first ultrasound image U1 of the first frame group and the second ultrasound image U2 of the second frame group.

[0086] If it is determined in step S15 to continue updating the frame, the process returns to step S13, where the first ultrasound image U1 is manually selected by the user. In the subsequent step S14, the second ultrasound image U2, which corresponds to the first ultrasound image U1 selected in step S13, is automatically selected.

[0087] In the repeated steps S13 to S15 performed in this manner, the user can select the first ultrasound image U1 of the first frame group and the second ultrasound image U2 of the second frame group that are optimal for measuring the ejection fraction of the lumen of the heart H, while checking the first ultrasound image U1 of the first frame group and the second ultrasound image U2 of the second frame group that are displayed on the monitor 23 as they are updated in real time. Furthermore, by simply selecting the first ultrasound image U1, the corresponding second ultrasound image U2 is automatically selected and displayed on the monitor 23, allowing the user to quickly and easily select the first ultrasound image U1 of the first frame group and the second ultrasound image U2 of the second frame group that are optimal for measuring the ejection fraction of the lumen of the heart H.

[0088] If it is determined in step S12 that the frames of the first ultrasound image U1 in the first frame group and the second ultrasound image U2 in the second frame group will not be updated, and if it is determined in step S15 that the updating of the frames of the first ultrasound image U1 in the first frame group and the second ultrasound image U2 in the second frame group will be completed, the process proceeds to step S16.

[0089] In step S16, if the measurement unit 30 determines in step S12 that it will not update the frames of the first ultrasound image U1 of the first frame group and the second ultrasound image U2 of the second frame group, it calculates the ejection fraction of the lumen of the heart H using the value of the cross-sectional area of ​​the lumen of the heart H corresponding to the first ultrasound image U1 of the first frame group selected in step S10 and the value of the cross-sectional area of ​​the lumen of the heart H corresponding to the second ultrasound image U2 of the second frame group selected in step S11. Also, if the measurement unit 30 determines in step S15 that it will finish updating the frames of the first ultrasound image U1 of the first frame group and the second ultrasound image U2 of the second frame group, it calculates the ejection fraction of the lumen of the heart H using the value of the cross-sectional area of ​​the lumen of the heart H corresponding to the first ultrasound image U1 of the first frame group selected in step S13 and the value of the cross-sectional area of ​​the lumen of the heart H corresponding to the second ultrasound image U2 of the second frame group selected in step S14.

[0090] The value of the ejection fraction of the lumen of the heart H calculated in step S16 can be displayed on monitor 23 together with the first cross-sectional area change curve C1, the second cross-sectional area change curve C2, the first ultrasound image U1, and the second ultrasound image U2, as shown in Figure 11. Once the processing in step S16 is completed, the operation of the ultrasound diagnostic device of Embodiment 1 shown in Figure 12 is completed.

[0091] As described above, according to the ultrasound diagnostic apparatus of Embodiment 1, the cross-sectional area change curve generation unit 25 generates a first cross-sectional area change curve C1 and a second cross-sectional area change curve C2 based on the cross-sectional area calculated by the cross-sectional area calculation unit 24, the alignment unit 26 aligns the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2 with respect to each other, the monitor 23 displays the first ultrasound image U1 and the second ultrasound image U2 at corresponding points on the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2, and the frame update unit 29 automatically updates the other frame of the first ultrasound image U1 and the second ultrasound image U2 in accordance with the updated frame when one of the frames of the first ultrasound image U1 and the second ultrasound image U2 displayed on the monitor 23 is updated based on the user's instruction, so that the ejection fraction of the lumen of the heart H can be calculated quickly and easily.

[0092] 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.

[0093] 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.

[0094] The apical four-chamber section 4C is described as the first section corresponding to the first ultrasound image U1, and the apical two-chamber section 2C is described as the second section corresponding to the second ultrasound image U2. However, it is also possible to treat the apical four-chamber section 4C as the second section and the apical two-chamber section 2C as the first section.

[0095] When the curve selection unit 51 of the alignment unit 26 selects the first curve portion D1 and the second curve portion D2 based solely on user input via the input device 32, the curve selection unit 51 can determine whether the number of change cycles included in the first curve portion D1 and the number of change cycles included in the second curve portion D2 are the same. If the number of change cycles included in the first curve portion D1 and the number of change cycles included in the second curve portion D2 are different, the curve selection unit 51 can warn the user by displaying a message on the monitor 23, for example, "Please select curves that include the same number of change cycles."

[0096] The main body of the device 2 may also have a cross-sectional area correction unit (not shown) that, after the measurement unit 30 has determined the first ultrasound image U1 of the first frame group and the second ultrasound image U2 of the second frame group used to calculate the ejection fraction of the lumen of the heart H, corrects the contour of the lumen of the heart H or the image area occupied by the lumen of the heart H as seen in these frames, and corrects the cross-sectional area of ​​the lumen of the heart H based on the corrected contour or image area. In this case, the cross-sectional area correction unit is connected, for example, to the frame selection unit 28, the frame update unit 29, the measurement unit 30, and the main body control unit 31.

[0097] The cross-sectional area correction unit corrects the contour of the lumen of the heart H or the image area occupied by the lumen of the heart H as seen in one of the first ultrasound image U1 of the first frame group and the second ultrasound image U2 of the second frame group, based on user instructions via the input device 32. It also automatically corrects the contour of the lumen of the heart H or the image area occupied by the lumen of the heart H as seen in the other of the first ultrasound image U1 of the first frame group and the second ultrasound image U2 of the second frame group, using the same correction method as the user's correction of the lumen of the heart H in one frame. For example, if a correction is made to move a part of the contour of the lumen of the heart H in the first ultrasound image U1 to a shallower area, a correction is automatically made to move the corresponding part of the contour of the lumen of the heart H in the second ultrasound image U2 to a shallower area.

[0098] The cross-sectional area correction unit can, for example, output a corrected second ultrasound image U2 in the same way as the first ultrasound image U1 by inputting the first ultrasound image U1 before and after correction and the uncorrected second ultrasound image U2 into a trained machine learning model that has been trained on numerous first ultrasound images U1 before and after correction and numerous second ultrasound images U2 before and after correction.

[0099] Embodiment 2 The alignment unit 26 selects the first curve portion D1 and the second curve portion D2 from the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2 based on input from the user via the input device 32. However, it can also automatically select portions that are similar to each other in the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2.

[0100] Figure 14 shows a block diagram of the ultrasound diagnostic apparatus of Embodiment 2. The ultrasound diagnostic apparatus of Embodiment 2 is equipped with an apparatus body 2A in place of the apparatus body 2 shown in Figure 1. The apparatus body 2A in Embodiment 2 is equipped with an alignment unit 26A in place of the alignment unit 26 in the apparatus body 2 of Embodiment 1, and an apparatus body control unit 31A in place of the apparatus body control unit 31. Furthermore, a processor 34A for the apparatus body 2A is configured by an image generation unit 21, a display control unit 22, a cross-sectional area calculation unit 24, a cross-sectional area change curve generation unit 25, an alignment unit 26A, a frame selection unit 28, a frame update unit 29, a measurement unit 30, and an apparatus body control unit 31.

[0101] The alignment unit 26A aligns the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2 with each other. As shown in Figure 15, the alignment unit 26A has a configuration in which a normalization unit 54, a similarity part identification unit 55, and a partial alignment unit 56 are connected in series.

[0102] The normalization unit 54 normalizes the entire first cross-sectional area change curve C1 and the entire second cross-sectional area change curve C2. The normalization unit 54 can normalize the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2 by dividing them by their respective maximum values.

[0103] Furthermore, the normalization unit 54 can also normalize the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2 by performing so-called Z-score normalization using the mean and standard deviation of the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2, respectively. This Z-score normalization makes the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2 smoother, so that even if there are many outliers in the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2, i.e., frames in which the lumen of the heart H is incorrectly extracted, the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2 can be aligned with high accuracy.

[0104] As schematically shown in Figure 16, the similarity portion identification unit 55 identifies portions that are similar to each other in the normalized first cross-sectional area change curve C1 and the normalized second cross-sectional area change curve C2 as the first curve portion D1 and the second curve portion D2.

[0105] As a specific example, the similarity identification unit 55 divides the interval from the start time to the end time of the first cross-sectional area change curve C1 into M parts at regular time intervals, and sets the first matrix X, which represents the normalized values ​​in the first cross-sectional area change curve C1 corresponding to the M divided division times, as shown in equation (1) above.

[0106] Furthermore, the similarity identification unit 55 divides the interval from the start time to the end time of the second cross-sectional area change curve C2 into N parts at regular time intervals, and sets the second matrix Y, which represents the normalized values ​​in the second cross-sectional area change curve C2 corresponding to the N divided division times, as shown in equation (2) above.

[0107] The similarity identification unit 55 uses each element of the first matrix X and each element of the second matrix Y to create a two-dimensional array, for example, as shown in Figure 17. The similarity identification unit 55 considers elements XL and YK to be equal if the absolute value of the difference |XL-YK| between element XL of the first matrix X and element YK of the second matrix Y is less than or equal to a predetermined threshold. It then calculates multiple paths G in the two-dimensional array, moving in the direction from element X1 to element XM and from element Y1 to element YN, where elements of the first matrix X and the second matrix Y are consecutively equal, using, for example, dynamic programming. Here, L is an integer between 1 and M, and K is an integer between 1 and N.

[0108] The similarity portion identification unit 55 identifies the longest path G1 among the multiple paths G calculated, and identifies the portion of the first cross-sectional area change curve C1 corresponding to the section from element XS of the first matrix X at the starting point (XS, YS) of path G1 to element XE of the first matrix X at the ending point (XE, YE) of path G1 as the first curve portion D1. The similarity portion identification unit 55 also identifies the portion of the second cross-sectional area change curve C2 corresponding to the section from element YS of the second matrix Y at the starting point (XS, YS) of path G1 to element YE of the second matrix Y at the ending point (XE, YE) of path G1 as the second curve portion D2. Here, S is an integer between 1 and M, and E is an integer between 1 and N.

[0109] Furthermore, if multiple longest paths G1 are calculated, the similarity section identification unit 55 can identify the path G1 with the smallest sum of the absolute difference between the elements of the first matrix X and the second matrix Y in those paths G1, i.e., the sum of |XL-YK|, as the final path G1. The smaller the sum of the difference values ​​|XL-YK| in a path G, the more similar the first curved section D1 and the second curved section D2 corresponding to that path G can be considered to be.

[0110] The partial alignment unit 56 aligns the first curve portion D1 and the second curve portion D2 identified by the similarity portion identification unit 55 with each other. The partial alignment unit 56 can align the points corresponding to (E-S+1) division times on the first curve portion D1 with the points corresponding to (E-S+1) division times on the second curve portion D2, as shown in Figure 16, by, for example, associating the elements XL and YK in the coordinates (XL,YK) of each point on the longest path G in the two-dimensional array created by the similarity portion identification unit 55 with each other.

[0111] Furthermore, the partial alignment unit 56 can also align the first curved portion D1 and the second curved portion D2 with each other using an algorithm such as DTW, as in the partial alignment unit 53 in Embodiment 1.

[0112] Thus, with the alignment unit 26A in Embodiment 2, the user does not need to perform any input operations to select the first curved portion D1 and the second curved portion D2, making it easier to align the first curved portion D1 and the second curved portion D2.

[0113] Next, the alignment process by the alignment unit 26A will be explained using the flowchart shown in Figure 18. First, in step S24, the normalization unit 54 of the alignment unit 26A normalizes the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2 generated by the cross-sectional area change curve generation unit 25. In this process, the normalization unit 54 can normalize the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2 by dividing them by their respective maximum values. Alternatively, the normalization unit 54 can also normalize the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2 by performing Z-score normalization on them.

[0114] In step S25, the similarity portion identification unit 55 of the alignment unit 26A identifies the longest similar portions of the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2, which were normalized in step S24, as the first curve portion D1 and the second curve portion D2. The similarity portion identification unit 55 creates a two-dimensional array as shown in Figure 17, for example, using each element when the interval of the first cross-sectional area change curve C1 is divided into M parts and each element when the interval of the second cross-sectional area change curve C2 is divided into N parts. In this two-dimensional array, the similarity portion identification unit 55 identifies the longest path G1 in which the elements of the first cross-sectional area change curve C1 and the elements of the second cross-sectional area change curve C2 are consecutive and equal to each other. The similarity portion identification unit 55 can identify the portions corresponding to the identified path G in the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2 as the first curve portion D1 and the second curve portion D2, respectively.

[0115] Finally, in step S26, the partial alignment unit 56 of the alignment unit 26A aligns the first curve portion D1 and the second curve portion D2 identified in step S25 with respect to each other. The partial alignment unit 56 can align the points corresponding to (E-S+1) division times on the first curve portion D1 with the points corresponding to (E-S+1) division times on the second curve portion D2, as shown in Figure 16, by, for example, associating the elements XL and YK in the coordinates (XL,YK) of each point on the longest path G in the two-dimensional array created by the similar portion identification unit 55 with each other.

[0116] As described above, according to the ultrasound diagnostic apparatus of Embodiment 2, the alignment unit 26A automatically identifies the first curve portion D1 and the second curve portion D2, which are similar to each other, from the first cross-sectional area change curve C1 and the second cross-sectional area change curve C2. Therefore, the user does not need to perform any input operations to select the first curve portion D1 and the second curve portion D2, making it easier to align the first curve portion D1 and the second curve portion D2. [Explanation of Symbols]

[0117] 1 Ultrasound probe, 2,2A Main unit, 11 Transducer array, 12 Transmit / receive circuit, 21 Image generation unit, 22 Display control unit, 23 Monitor, 24 Cross-sectional area calculation unit, 25 Cross-sectional area change curve generation unit, 26,26A Alignment unit, 27 Memory, 28 Frame selection unit, 29 Frame update unit, 30 Measurement unit, 31,31A Main unit control unit, 32 Input device, 33 Image acquisition unit, 34,34A Processor, 41 Pulsar, 42 Amplification unit, 43 AD conversion unit, 44 Beamformer, 45 Signal processing unit, 46 DSC, 47 Image processing unit, 51 Curve selection unit, 52,54 Normalization unit, 53,56 Partial alignment unit, 55 Similar part identification unit, 2C Apical two-chamber section, 4C Apical four-chamber section, A1,A2 Left ventricle, B,G,G1 Pathway, B1 Minimum pathway, C1 First cross-sectional area change curve, C2 Second cross-sectional area change curve, D1 First curve portion, D2 Second curve portion, H Heart, Q1, Q2 Maximum value, R1, R2 Minimum value, P1, P2 Point, U1 First ultrasound image, U2 Second ultrasound image, X1, XE, XM, XS, Y1, YE, YM, YS Elements.

Claims

1. An image acquisition unit acquires a first ultrasound image consisting of multiple frames that are sequentially time-series and capture a first cross-section of the subject's heart, and a second ultrasound image consisting of multiple frames that are sequentially time-series and capture a second cross-section of the heart different from the first cross-section. A cross-sectional area calculation unit calculates the cross-sectional area of ​​the lumen of the heart for each frame of the first ultrasound images and the second ultrasound images of the plurality of frames, A cross-sectional area change curve generation unit generates a first cross-sectional area change curve for the first cross-section and a second cross-sectional area change curve for the second cross-section, respectively, which represent the temporal change of the cross-sectional area, based on the cross-sectional area calculated by the cross-sectional area calculation unit. A positioning unit that aligns the first cross-sectional area change curve and the second cross-sectional area change curve generated by the cross-sectional area change curve generation unit with respect to each other, A monitor that displays the first ultrasound image and the second ultrasound image at corresponding points on the first cross-sectional area change curve and the second cross-sectional area change curve, When one of the first ultrasound image and the second ultrasound image displayed on the monitor is updated based on user instructions, a frame update unit automatically updates the other frame of the first ultrasound image and the second ultrasound image in correspondence with the first frame. An ultrasound diagnostic device equipped with the following features.

2. The aforementioned alignment portion is A curve selection unit that selects a first curve portion and a second curve portion that each contain the same number of change cycles for the first cross-sectional area change curve and the second cross-sectional area change curve, respectively. A normalization unit that normalizes the first curved portion and the second curved portion, The ultrasonic diagnostic apparatus according to claim 1, further comprising a partial alignment unit that aligns the first curve portion and the second curve portion, which have been normalized by the normalization unit, with respect to each other.

3. The ultrasound diagnostic apparatus according to claim 2, wherein the curve selection unit selects the first curve portion and the second curve portion based on the interval selected by the user in the first cross-sectional area change curve and the second cross-sectional area change curve.

4. The curve selection unit is, Based on the interval selected by the user, the first curve portion or the second curve portion is selected for the first cross-sectional area change curve or the second cross-sectional area change curve. The number of change cycles included in either the first curve portion or the second curve portion is calculated. The ultrasound diagnostic apparatus according to claim 2, which selects the other of the first curve portion and the second curve portion based on the calculated number of change cycles.

5. The ultrasound diagnostic apparatus according to claim 2, wherein the curve selection unit selects the first curve portion and the second curve portion, which include the same number of change cycles as the specified number of cycles specified by the user.

6. The ultrasound diagnostic apparatus according to claim 2, wherein the normalization unit normalizes the first curve portion and the second curve portion by their respective maximum values.

7. The aforementioned alignment portion is A normalization unit that normalizes the first cross-sectional area change curve and the second cross-sectional area change curve, A similarity portion identification unit identifies the first curve portion and the second curve portion, which are the portions that are most similar to each other among the first cross-sectional area change curve and the second cross-sectional area change curve, respectively, which have been normalized by the normalization unit, The ultrasonic diagnostic apparatus according to claim 1, having a partial alignment section that aligns the identified first curved portion and the second curved portion with respect to each other.

8. The ultrasound diagnostic apparatus according to claim 7, wherein the normalization unit normalizes the first cross-sectional area change curve and the second cross-sectional area change curve by their respective maximum values.

9. The ultrasound diagnostic apparatus according to claim 7, wherein the normalization unit normalizes the first cross-sectional area change curve and the second cross-sectional area change curve using their respective mean and standard deviations.

10. The ultrasound diagnostic apparatus according to any one of claims 1 to 9, further comprising a frame selection unit that selects a set of first ultrasound images corresponding to the maximum and minimum values ​​in the first cross-sectional area change curve as a first measurement frame group, and a set of second ultrasound images corresponding to the maximum and minimum values ​​in the second cross-sectional area change curve, which have been aligned to the maximum and minimum values ​​in the first cross-sectional area change curve by the alignment unit, as a second measurement frame group.

11. The monitor displays the first ultrasound image of the first measurement frame group and the second ultrasound image of the second measurement frame group selected by the frame selection unit. The ultrasound diagnostic apparatus according to claim 10, wherein when one of the frames of the first ultrasound image and the second ultrasound image displayed on the monitor is updated, the frame update unit updates the other frame of the first ultrasound image and the second ultrasound image in correspondence with the one frame.

12. First ultrasound images consisting of multiple frames that are sequentially continuous and capture a first cross-section of the subject's heart, and second ultrasound images consisting of multiple frames that are sequentially continuous and capture a second cross-section of the heart different from the first cross-section, are acquired. For each frame of the first ultrasound image and the second ultrasound image of the plurality of frames, the cross-sectional area of ​​the lumen of the heart is calculated. Based on the calculated cross-sectional area, a first cross-sectional area change curve for the first cross-section and a second cross-sectional area change curve for the second cross-section are generated, respectively, representing the change in the cross-sectional area over time. The first cross-sectional area change curve and the second cross-sectional area change curve are aligned with each other, The first ultrasound image and the second ultrasound image are displayed at corresponding points on the first cross-sectional area change curve and the second cross-sectional area change curve, When one of the displayed frames of the first ultrasound image and the second ultrasound image is updated based on user instructions, the other frame of the first ultrasound image and the second ultrasound image is automatically updated in accordance with the first frame. A method for controlling an ultrasound diagnostic device.

Images