Search device and program for obtaining echo images

Abstract

To automatically search for position information and posture information of a probe which can acquire a desired echo image in an echo examination.SOLUTION: A searching device 13, for searching for the arrangement state of a probe P, which is proper for obtaining a desired echo image by an ultrasonic image pickup device 11 that acquires an echo image in the body by bringing the probe into contact with the body surface of a subject, comprises an image processing unit 16 which analyzes a plurality of pieces of image data in which the arrangement information of the probe P corresponds to the echo images captured in mutually-different arrangement states and decides the arrangement information in the proper arrangement state as desired information. The image processing unit 16 specifies prescribed image data on the basis of the visualization state of a prescribed portion in the plurality of echo images and decides the desired information from the arrangement information when the image data is acquired.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a search device and a program for an echo image acquisition for searching for an appropriate position and posture of a probe applied to the body surface of a subject when acquiring a desired echo image.

Background Art

[0002] In recent years, in Japan, transthoracic echocardiography (hereinafter referred to as "echocardiography"), which enables non-invasive and highly accurate diagnosis of heart diseases that rank among the top causes of death, has attracted attention. In echocardiography, in order to ensure the clarity of echocardiogram images, it is recommended to apply a probe from an appropriate ultrasonic incidence site called an acoustic window. When acquiring an echocardiogram image from other sites, it becomes difficult to obtain a clear echocardiogram image due to virtual images called artifacts and image distortion. Here, the basic cross-section used for diagnosing the disease state can be drawn by finely adjusting the angle of the probe at the position of the acoustic window, but proficiency is required in the probe operation technique for drawing the basic cross-section.

[0003] That is, since the lungs that affect the clarity of echocardiogram images and the sternum and ribs that cause missing echocardiogram images are present around the heart, in order to obtain the basic cross-section, it is necessary to search for a small number of appropriate positions and postures of the probe. However, even if breathing instructions and body position instructions are given to the subject, there are individual differences in the position and orientation of the heart, so the appropriate probe position information and posture information for the subject cannot be specified in advance. In addition, in echocardiography, it is necessary to grasp the three-dimensional structure of the heart and clearly draw it in detail, so it requires high technology and empirical rules, and the examination tends to take a long time, increasing the burden on the subject.

[0004] Early detection of heart disease by echocardiography has not been sufficiently carried out due to a shortage of doctors and the difficulty of the above-mentioned examination techniques. Therefore, the inventors have been promoting the development of a robot for the purpose of assisting by remote operation and autonomous operation in order to facilitate the early detection of heart disease by echocardiography. If a robot can automatically acquire diagnostic images called basic cross-sections, efficient assistance will be possible.

[0005] By the way, a robot is known that, by the remote operation of an operator, applies a probe of an ultrasonic diagnostic apparatus attached to the tip of a robot arm to the affected part of a patient to acquire an ultrasonic image of the affected part (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, even when using a conventional robot such as Patent Document 1 for echocardiography, the position and posture of the probe that can appropriately acquire the basic cross-section are still determined while a doctor or the like visually observes the ultrasonic image, and thus it still depends on the experience and technique of the doctor or the like. Therefore, the automation and efficiency of echocardiography by the robot cannot be fully demonstrated.

[0008] The present invention has been devised by paying attention to such problems, and an object thereof is to provide a search device and a program for echo image acquisition that can automatically search for position information and posture information of a probe capable of acquiring a desired echo image in an echo examination.

Means for Solving the Problems

[0009] To achieve the above object, the present invention mainly provides an apparatus for searching for an arrangement state of a probe suitable for obtaining a desired echo image by an ultrasonic imaging apparatus that acquires an echo image inside the body by bringing the probe into contact with the body surface of a subject. The apparatus analyzes a plurality of image data in which arrangement information of the probe is respectively associated with the echo images captured in mutually different arrangement states, and includes an image processing unit that determines the arrangement information in the appropriate arrangement state as desired information. In the image processing unit, based on the depiction state of a predetermined part in a plurality of the echo images, a predetermined one of the image data is specified, and the desired information is determined from the arrangement information when the image data is acquired.

[0010] In the claims of the present patent and in this specification, unless otherwise specified, the directions of the position and orientation of the probe P are the directions shown in FIG. 1. That is, in the coordinates of the three orthogonal axes representing the position of the probe P, the "x-axis direction" is the head-tail direction of the subject, the "y-axis direction" is the lateral (left-right) direction of the subject, and the "z-axis direction" is the normal direction of the body surface of the subject. Also, when the central portion at the lower end of the probe P in the direction shown in the figure is used as the rotation center, the "roll direction" is the rotation direction around the axis (the x-axis) orthogonal to the beam scanning plane F, the "pitch direction" is the rotation direction of swinging the beam scanning plane F back and forth (around the y-axis), and the "yaw direction" is the rotation direction around the z-axis.

Advantages of the Invention

[0011] According to the present invention, it is possible to automatically identify the position information and orientation information of the probe capable of acquiring a desired echo image. Therefore, at the time of diagnosis in an echocardiogram examination by remote operation of a robot, by moving and rotating the probe within a predetermined range, it is possible to automatically acquire a desired echocardiogram image, and further popularization of the echocardiogram examination can be expected due to automation and efficiency improvement by the robot.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0014] FIG. 1 shows a diagram representing the schematic configuration of an echocardiogram inspection system including a search device for obtaining an echocardiogram image according to the present embodiment. In this figure, the echocardiogram inspection system 10 is a system that enables an echocardiogram inspection of a subject who is in a place away from the doctor. Specifically, this echocardiogram inspection system 10 includes an ultrasonic image imaging device 11 that images an echocardiogram image of the heart (hereinafter referred to as an "echocardiogram image") by bringing a probe P into contact with the body surface of the chest of the subject, a probe moving device 12 that moves the probe P, and a search device 13 that searches for an appropriate arrangement state of the probe P when a desired echocardiogram image can be obtained with respect to the arrangement information including the position information and the attitude information of the probe P by processing and analyzing the acquired echocardiogram image.

[0015] As the ultrasonic imaging device 11, a known ultrasonic diagnostic device capable of acquiring an ultrasonic image (echo image) for performing two-dimensional or three-dimensional cardiac echo examination is applied. That is, in this ultrasonic imaging device 11, a cardiac echo image, which is a two-dimensional tomographic image in the same cross-section as the beam scanning surface F, is acquired by beam scanning with the probe P.

[0016] The probe moving device 12 is a robot that enables the probe P to perform a six-degree-of-freedom motion consisting of translational motion in three orthogonal axes and rotational motion around three orthogonal axes by operating a holding part (not shown) that holds the probe P by remote operation by a doctor or the like. Since the robot is not an essential element of the present invention, detailed descriptions of its configuration and the like are omitted.

[0017] In addition, the probe P is provided with a known sensor (not shown) capable of detecting its position information and attitude information. This sensor can acquire three-dimensional arrangement information consisting of position information at each coordinate of three orthogonal axes with a predetermined point as the origin and attitude information that is the rotation angle around the three axes. Here, as the sensor, various devices can be adopted as long as the above arrangement information can be acquired, such as an acceleration sensor, a magnetic sensor, and an optical sensor. Also, the coordinate system in the arrangement information is set in advance with a predetermined position as the origin.

[0018] The search device 13 is constituted by a computer including an arithmetic processing device such as a CPU and storage devices such as a memory and a hard disk.

[0019] This search device 13 includes a storage unit 15 that stores image data including the cardiac echo image acquired by the ultrasonic imaging device 11, and an image processing unit 16 that analyzes the image data extracted from the storage unit 15 and determines the above arrangement information in the arrangement state of the probe P that is appropriate for the cardiac echo examination as desired information.

[0020] The image data is data in which position information and orientation information of the probe P at the time of acquiring an echocardiogram image are associated with the echocardiogram image from the detection results of the sensor attached to the probe P. In the storage unit 13, the image data is sequentially stored at predetermined timings during the movement or rotation of the probe P.

[0021] In the image processing unit 16, position information and orientation information of the probe P that enable acquisition of an echocardiogram image of a target cross-section called the parasternal left ventricular long-axis cross-section, which is the cross-section with the most findings among the basic cross-sections used for diagnosing pathological conditions in echocardiography, are determined as desired position information and desired orientation information (desired information).

[0022] As an echocardiogram image of the parasternal left ventricular long-axis cross-section, as schematically shown in FIG. 2, the right ventricle 51 is depicted at the upper top of the fan-shaped outer shape, and the left ventricular wall 52, left ventricle 53, mitral valve 54, left atrium 55, etc. are depicted at the lower side thereof.

[0023] Here, as the position information of the probe P, two-degree-of-freedom position information in the x-axis direction and the y-axis direction excluding the z-axis direction, which is the pressing direction on the body surface that is uniquely determined with respect to the body surface to enable acquisition of an echocardiogram image, is targeted. Further, as the orientation information of the probe P, two-degree-of-freedom angular information in the yaw direction and the pitch direction excluding the roll direction that is uniquely determined to move the echocardiogram image on the central axis is targeted.

[0024] In the image processing unit 16, based on the depiction status of the left ventricular wall 52 and the mitral valve 54, which are predetermined sites, among a plurality of echocardiogram images obtained in different arrangement states of the probe P by scanning due to the movement and rotation of the probe P by the probe moving device 12, the predetermined image data is specified, and the desired position information and the desired orientation information are determined from the arrangement information of the probe P when the image data is acquired.

[0025] Specifically, the image processing unit 16 includes a position search unit 18 that searches for desired position information of the probe P that is appropriate for acquiring a target cross-section of the echocardiogram image according to the drawing state of the mitral valve 54 serving as a reference point, and an attitude search unit 19 that searches for desired attitude information of the probe P that is appropriate for acquiring a target cross-section of the echocardiogram image.

[0026] The position search unit 18 searches for desired position information consisting of the coordinates of the probe P in the x-axis and y-axis directions where the mitral valve 54 appears in the echocardiogram image.

[0027] That is, here, a known object detection system such as YOLO that uses a deep learning model or the like for recognizing a predetermined object based on the learned image data is applied. From the echocardiogram images acquired at each position of the probe P, an estimated value representing the presence and probability of the pre-learned mitral valve 54 is calculated. Then, the coordinates in the x-axis and y-axis directions representing the position of the probe P that has acquired the echocardiogram image with the highest such estimated value are taken as the desired position information. Note that as the object detection system, various other systems and devices using different methods can be adopted as long as they can estimate the presence of the mitral valve 54 in the echocardiogram image.

[0028] The procedure for searching for and determining the desired position information will be described below while referring to the flowchart of FIG. 3.

[0029] First, with the probe P fixed at a predetermined attitude with the angles in the yaw direction and pitch direction set to predetermined values, the probe P is scanned along a predetermined range on the chest surface of the subject by the operation of the probe moving device 12 (step S101). At this time, the image data acquired at each of the n positions is stored in the storage unit 15 (step S102). Then, when the scanning of the probe P within the predetermined range is completed, the following image processing is performed on all the image data for each acquisition position stored in the storage unit 15 by the position search unit 18. That is, the image data at a predetermined position with coordinates (xi, yi) (i = 1, 2... n) is extracted from the storage unit 15 (step S103), and the detection of the mitral valve 54 is performed on the echocardiogram image of one frame (step S104). Then, for the echocardiogram image in which the mitral valve 54 is detected, it is determined whether the mitral valve 54 is located in a predetermined end region of the preset echocardiogram image by known image processing (step S105). Therefore, when the mitral valve 54 is not located in the end region, the estimated value of the mitral valve 54 in the echocardiogram image is stored in the image data in a state where it is recorded corresponding to the image data (step S106). Note that when the mitral valve 54 is not detected in the above procedure, or when the mitral valve 54 is located in the end region, the same image processing is performed on the image data acquired at other positions.

[0030] After the above image processing is performed on all the image data acquired by the scanning of the probe P (step S107), the presence or absence of the estimated value is determined (step S108). Here, when there is image data in which the estimated value is recorded, the image data having the largest estimated value among them is determined to have a high estimated value, and the position information at the time of its acquisition is determined as the desired position information of the probe P (step S109). On the other hand, when the mitral valve 54 is not detected for all the image data, or when the mitral valve 54 is detected only in the end region of the echocardiogram image, since there is no image data in which the estimated value is recorded, after changing the angles in the yaw direction and pitch direction of the probe P to other values to change the attitude (step S110), the probe P is scanned again along the predetermined range on the chest surface, and the above-described processing is repeated.

[0031] Note that the procedure for searching and determining the desired position information of the probe P is not limited to the above, and can also be performed according to the procedure of the following modification example.

[0032] In the above procedure, after acquiring all the image data at each position in the area where the probe P has moved, the above-described image processing is performed. However, in this modification example, at each position on the path where the probe P moves, the above-described image processing is performed each time, and when the image data of the predetermined estimated value is obtained, the position information is determined as the desired position information of the probe.

[0033] That is, as shown in FIG. 4, first, with the probe P fixed at a predetermined attitude with the angles in the yaw direction and the pitch direction set to predetermined values, the probe is scanned along a predetermined path by the operation of the probe moving device 12 (step S201), and image data is acquired at the first position (step S202). Next, for the image data at this position, the position search unit 18 detects the mitral valve 54 (step S203). Then, for the echocardiogram image in which the mitral valve 54 is detected, it is determined whether or not the mitral valve 54 is located in the end region of the preset echocardiogram image in the same manner as described above (step S204). After that, when the mitral valve 54 is not located in the end region, it is determined whether or not the estimated value of the mitral valve 54 in the image data is equal to or greater than a preset threshold value (step S205). When the estimated value is equal to or greater than the threshold value, it is determined that the estimated value is high, and the path movement by the probe moving device 12 is stopped (step S206), and the position information of the probe P at that time is determined as the desired position information (step S207). On the other hand, when the mitral valve 54 is not detected by the position search unit 18, when the mitral valve 54 is located in the end region, or when the estimated value is less than the threshold value, the probe P moves to the next position and the same image processing is performed. Then, even if the probe P moves over the entire preset path and the desired position information cannot be obtained by the above-described processing, after changing the angles in the yaw direction and the pitch direction of the probe P to different values and changing the attitude (step S208), the probe P moves again on the path and the image processing is performed according to the above-described procedure.

[0034] In addition, in the above-described modification, the desired position information is determined using the threshold value of the estimated value. As a modification to this modification, as shown in FIG. 5, the movement of the probe P is continued until the estimated value of the echocardiogram image acquired as the probe P moves on the path continues to increase continuously (step S205A), and the position of the last probe having the maximum estimated value determined to be a high estimated value is used as the desired position information (step S207A). This mode can also be adopted.

[0035] As shown in FIG. 6, the posture search unit 19 includes a yaw angle search unit 21 that searches for a desired yaw angle, which is desired posture information in the yaw direction of the probe P, so as to be able to draw a cross-section along the left ventricular long axis L, which is a straight line connecting the cardiac apex 56 at the tip of the left ventricle and the mitral valve 54, and a pitch angle search unit 22 that searches for a desired pitch angle, which is desired posture information in the pitch direction of the probe P, for recognizing the mitral valve 54 at a position where the chordae tendineae and the papillary muscles are not continuous.

[0036] In the yaw angle search unit 21, based on the following concept, the rotation angle in the yaw direction of the probe P capable of drawing a cardiac echo image along the left ventricular long axis L is determined as the desired yaw angle.

[0037] Focusing on the shape of the left ventricle of the heart to estimate the angle of the left ventricular long axis L. As shown in FIG. 6, the left ventricle 53 can be approximated by a rotational ellipsoid, and its central axis coincides with the left ventricular long axis L. Also, due to the symmetry of the rotational ellipsoid, it is considered that there is a cross-section symmetrical to the left ventricular long axis L in a cross-section passing through an arbitrary point O on the left ventricular long axis L. That is, the median value of the rotation angles of the probe P at which these cross-sections are obtained will coincide with the left ventricular long axis L. Here, considering that the left ventricular long axis L is a straight line connecting the cardiac apex 56 and the mitral valve 54, there is a cross-section A´ symmetrical to the left ventricular long axis in the cross-section A of the left ventricle passing through the mitral valve 54. Next, focusing on the cross-section when the probe P is rotated clockwise in the yaw direction from the rotation angle of the probe P at which a cross-section including the left ventricular long axis L is obtained. At this time, the shape of the left ventricular wall 52 of the cross-section drawn by the probe P changes from a tubular shape (open state) in which a part of the outer peripheral portion at the left end of the image is open to an elliptical shape or a circular shape (closed state) in which the outer peripheral portion is continuously blocked. Also, when the probe is rotated in the reverse direction, the shape of the left ventricular wall 52 changes in the same way. Here, paying attention to the critical angle θ, which is the yaw angle between two boundary points F where the shape of the left ventricular wall 52 changes between the open state and the closed state, it is considered that the median value of the critical angle θ is the desired yaw angle of the probe P capable of obtaining a cross-section along the left ventricular long axis L.

[0038] Therefore, the following processing is performed in the yaw angle search unit 21. That is, centering on the position of the mitral valve 54, in the echocardiogram image obtained when the probe P is rotated in the yaw direction, from the image data stored in the storage unit 15 corresponding to the yaw direction angle (yaw angle) at the time of acquisition, by known image processing, an echocardiogram image is identified when the shape of the left ventricular wall 53 changes between the occluded state and the open state. Then, a critical angle is obtained from the yaw angle of the probe P associated with the echocardiogram image, and the median value thereof is determined as the desired yaw angle of the probe P from which a cross section drawn along the left ventricular long axis L can be obtained.

[0039] The procedure for searching for and determining the desired yaw angle will be described below with reference to the flowchart of FIG. 7.

[0040] First, the probe P is moved to a position corresponding to the aforementioned desired position information, and while maintaining the position and a predetermined posture in which the angle in the pitch direction is fixed to a predetermined value, the probe P is scanned by the probe moving device 12 while rotating 360 degrees in a full circle (step S301). At this time, the image data acquired at each of the n yaw angles is stored in the storage unit 15 (step S302). Then, when the full-circle rotation of the probe P is completed, the following image processing is performed on all the image data for each yaw angle stored in the storage unit 15 by the yaw angle search unit 21. That is, the target image data at a predetermined yaw angle (i = 1, 2 ··· n) that becomes the angle (εi) and the image data of each of a predetermined number of frames before and after it are extracted from the storage unit 15 (step S303). Then, by known image processing, it is determined whether or not an occluded left ventricular wall in which a part of the left ventricular wall 52 does not open is detected continuously for a predetermined number of frames (for example, 5 frames) before and after the target image data (step S304). And the target image data in which the occluded left ventricular wall is detected continuously for the predetermined number is recorded as the detected image data (step S305). When the occluded left ventricular wall is not detected continuously for the predetermined number, the same image processing is performed on the next target echocardiogram image acquired at another yaw angle.

[0041] After the above image processing is performed on all the image data obtained by scanning the entire circumference of the probe P in the yaw direction (step S306), the presence or absence of the detected image data is determined (step S307). And when the detected image data exists, the critical angle is calculated from two yaw angles of the probe P when the detection of the detected image data starts by comparison with the front and rear frames (step S308). Then, the median value of the critical angle is calculated, and the yaw angle of the probe P corresponding to the median value is determined as the desired yaw angle (step S309). On the other hand, when the occluded left ventricular wall is not detected for all the image data, after changing the angle in the pitch direction of the probe P to another value and changing the posture (step S310), the above-described processing is performed again.

[0042] In the pitch angle search unit 22, in the parasternal left ventricular long-axis cross-section including the left ventricular long axis L, since it is necessary not to depict the papillary muscles and chordae tendineae of the left ventricle, the desired pitch angle of the probe P at the central position of the mitral valve 54 where the papillary muscles and chordae tendineae of the left ventricle 53 are not depicted is searched.

[0043] In this pitch angle search unit 22, after moving the probe P to a position corresponding to the desired position information capable of imaging the mitral valve 54 and with the posture of the probe P at the desired yaw angle, while changing the angle in the pitch direction (pitch angle) of the probe P, the desired pitch angle of the probe P is determined by specifying the image data obtained at the pitch angle at which the mitral valve 54 without continuous papillary muscles and chordae tendineae is depicted in the echocardiogram image.

[0044] That is, here, the same object detection system as the position search unit 18 is applied, and from the image data obtained at each pitch angle of the probe P, an estimated value representing the presence and its probability of the mitral valve 54 without continuous papillary muscles and chordae tendineae learned in advance is calculated. Then, in the same procedure as the position search unit 18 in the above-described embodiment and modification, the pitch angle of the probe P when the image data determined to have a high estimated value is obtained is set as the desired pitch angle.

[0045] Through the image processing in the above-described image processing unit 16, the position information and the attitude information of the probe P that can obtain an appropriate parasternal long-axis cross-sectional view of the left ventricle are specified, and the echocardiogram image obtained at the position and attitude of the probe P corresponding to these arrangement information is used as a parasternal long-axis cross-sectional view of the left ventricle that is useful for diagnosis.

[0046] Note that the search device 13 in the present invention is not limited to echocardiogram images, and in order to search for the arrangement state of the probe P that is appropriate for obtaining a desired echogram image, based on the depiction state of a predetermined part in a plurality of echogram images, appropriate image data is specified, and it is also possible to determine the arrangement information of the probe P when the image data is acquired as desired information.

[0047] Further, as the image processing unit 16, it is also possible to adopt an aspect in which only one of the position search unit 18 and the attitude search unit 19 is provided according to the grasping state of the desired information. Also, in the image processing unit 16, based on the depiction state of other parts such as other heart valves by the same method, it is also possible to determine the desired position information and the desired attitude information of the probe P for obtaining other desired basic cross-sectional views.

[0048] Furthermore, in the above-described embodiment, the movement and rotation of the probe P are performed by the operation of the probe moving device 12, but the present invention is not limited to this, and the movement and rotation of the probe P can be manually performed by the operator, and the search device 13 can automatically specify the appropriate position and attitude of the probe P.

[0049] In addition, the configuration and processing procedure of each part of the device in the present invention are not limited to the above description, and various modifications are possible as long as they exhibit substantially the same action.

Explanation of Reference Numerals

[0050] 11 Ultrasonic imaging device 13 Search device 16 Image processing unit 18 Position search unit 19 Attitude search unit 21 Yaw Angle Search Unit 22 Pitch Angle Search Unit P Probe L Left Ventricular Long Axis

Claims

1. An apparatus for searching for an arrangement state of a probe suitable for obtaining a desired echo image by an ultrasonic imaging apparatus that obtains an echo image inside the body by bringing the probe into contact with the body surface of a subject, comprising an image processing unit that analyzes a plurality of image data in which arrangement information of the probe is respectively associated with the echo images captured in different arrangement states and determines the arrangement information in the appropriate arrangement state as desired information, wherein in the image processing unit, based on the depiction state of a predetermined part in a plurality of the echo images, a predetermined one of the image data is specified, and the desired information is determined from the arrangement information when the image data is acquired, the image processing unit includes an attitude search unit that uses the attitude information of the probe as the arrangement information and searches for desired attitude information of the probe suitable for obtaining a target cross-section of the echo image of the heart as the desired information, the attitude search unit includes a yaw angle search unit that searches for a yaw angle in the yaw direction of the probe that enables acquisition of an echo image along the left ventricular long axis, which is a straight line connecting the cardiac apex at the tip of the left ventricle and the mitral valve, as the desired attitude information, wherein the yaw angle search unit estimates a critical angle, which is the yaw angle between two boundary points of an open state and a closed state of the left ventricular wall, from a change in the shape of the left ventricular region when the respective image data acquired each time while rotating the probe in the yaw direction are compared in the order of acquisition, and sets the yaw angle that is the median value of the critical angle as the desired attitude information for obtaining the target cross-section along the left ventricular long axis. A search apparatus for echo image acquisition characterized by this.

2. the image processing unit includes a position search unit that uses the position information of the probe as the arrangement information and searches for desired position information of the probe suitable for obtaining a target cross-section of the echo image of the heart as the desired information according to the depiction state of a cardiac valve serving as a reference point, wherein in the position search unit, based on the learned image data, an estimated value representing the possibility of the presence of the cardiac valve in each echo image is calculated by an object detection system that recognizes the cardiac valve in each echo image, and the position information corresponding to the echo image determined to have a high estimated value is set as the desired position information. The search apparatus for echo image acquisition according to Claim 1, characterized by this.

3. The posture search unit includes a pitch angle search unit that searches for a pitch angle in the pitch direction of the probe for recognizing a mitral valve in which the chordae tendineae and the papillary muscles are not connected as the desired posture information. In the pitch angle search unit, based on the learned image data, an object detection system that recognizes the mitral valve in which the chordae tendineae and the papillary muscles are not connected in the echo image calculates an estimated value representing the possibility of the presence of the mitral valve in each echo image, and the pitch angle corresponding to the echo image with the highest estimated value is used as the desired posture information. The search device for obtaining an echo image according to claim 1 or 2, characterized in that.

4. A program for a device that searches for an appropriate arrangement state of a probe to obtain a desired echo image by an ultrasonic imaging device that obtains an echo image inside the body by bringing the probe into contact with the body surface of a subject. Causing a computer to function as an image processing unit that analyzes a plurality of image data in which arrangement information of the probe is respectively associated with the echo images captured in different arrangement states, and determines the arrangement information in the appropriate arrangement state as desired information. In the image processing unit, based on the depiction state of a predetermined part in a plurality of the echo images, a predetermined image data is specified, and the desired information is determined from the arrangement information when the image data is acquired. The image processing unit uses the posture information of the probe as the arrangement information, and includes a posture search unit that searches for desired posture information of the probe that is appropriate for obtaining a target cross-section of the echo image of the heart as the desired information. The posture search unit includes a yaw angle search unit that searches for a yaw angle in the yaw direction of the probe that enables acquisition of an echo image along the left ventricular long axis, which is a straight line connecting the apex of the left ventricle and the mitral valve, as the desired posture information. In the yaw angle search unit, from the shape change of the left ventricular region when the respective image data acquired each time while rotating the probe in the yaw direction are compared in the order of acquisition, a critical angle that is the yaw angle between two boundary points of the open state and the closed state of the left ventricular wall is estimated, and the yaw angle that is the median value of the critical angle is used as the desired posture information for obtaining the target cross-section along the left ventricular long axis. A program for a search device for obtaining an echo image, characterized in that.

Images