WO2017094397A1

WO2017094397A1 - Ultrasonic wave analyzing device, ultrasonic wave analyzing method, and ultrasonic wave analyzing program

Info

Publication number: WO2017094397A1
Application number: PCT/JP2016/081571
Authority: WO
Inventors: 弥喜屋武; 竜雄新井; 武士河尻; 拓生嶋田
Original assignee: 古野電気株式会社
Priority date: 2015-12-04
Filing date: 2016-10-25
Publication date: 2017-06-08
Also published as: CN108601584A; JP6496042B2; JPWO2017094397A1; CN108601584B

Abstract

[Problem] To provide an ultrasonic wave analyzing device, an ultrasonic wave analyzing method, and an ultrasonic wave analyzing program that can easily adjust the angle of contact of an ultrasonic probe to a subject. [Solution] An ultrasonic wave analyzing device 10 comprising: a control unit 12 that controls an ultrasonic wave source so as to cause an ultrasonic signal to be transmitted from the ultrasonic wave source on a prescribed sound axis toward a plurality of mutually different positions on the surfaces of cartilage or the surfaces of subchondral bone of a subject; an echo data input unit 141 that receives the input of echo data of an echo signal formed by the ultrasonic signal transmitted by the control unit being reflected inside the subject; a position detection unit 142 that detects the position of the ultrasonic wave source and the positions of the mutually different plurality of cartilage surfaces or subchondral bone surfaces; a shape detection unit 143 that detects the shape of the cartilage surface or the subchondral bone surface on the basis of information from each position detected by the position detection unit; and an angle calculation unit 144 that calculates the angle formed by the sound axis of the ultrasonic signal and the normal direction of the cartilage surface or the subchondral bone surface at the position where the ultrasonic signal is transmitted.

Description

Ultrasonic analysis apparatus, ultrasonic analysis method, and ultrasonic analysis program

The present invention relates to an ultrasonic analysis apparatus, an ultrasonic analysis method, and an ultrasonic analysis program for transmitting an ultrasonic signal inside a subject and analyzing an echo signal of the ultrasonic signal reflected inside the subject.

As an apparatus for analyzing the state of cartilage, for example, there is an ultrasonic analysis apparatus described in Patent Document 1. The ultrasonic analysis apparatus of Patent Literature 1 transmits an ultrasonic signal from an ultrasonic probe that is in contact with the surface of the knee, and receives an echo signal reflected inside the knee with the ultrasonic probe. Then, the state of the cartilage is analyzed from the received echo signal.

JP 2010-305 A

In the ultrasonic analysis device of Patent Document 1, the echo signal from the inside of the knee varies depending on the contact angle of the ultrasonic probe with respect to the knee, so that the state of the cartilage is not required unless the ultrasonic probe is contacted with the knee at an appropriate angle. There is a problem that it cannot be analyzed accurately.

Therefore, an object of the present invention is to provide an ultrasonic analysis apparatus, an ultrasonic analysis method, and an ultrasonic analysis program that can easily adjust the contact angle of an ultrasonic probe to a subject.

The ultrasonic analysis apparatus according to the present invention controls the ultrasonic source to direct a predetermined sound axis from the ultrasonic source toward a plurality of different positions on the cartilage surface or subchondral bone surface inside the subject. A control unit that transmits an ultrasonic signal at the control unit, an echo data input unit that receives echo data of an echo signal obtained by reflecting the ultrasonic signal transmitted from the control unit inside the subject, and the ultrasonic data A position detection unit that detects positions of a plurality of different cartilage surfaces or subchondral bone surfaces different from the acoustic wave source, and the cartilage surface or the cartilage based on information on each position detected by the position detection unit An angle formed by a shape detection unit for detecting the shape of the lower bone surface, and a normal direction of the cartilage surface or the subchondral bone surface at the position where the ultrasonic signal is transmitted and the sound axis of the ultrasonic signal. Calculated angle It includes a detecting section, a.

In this configuration, since the user can grasp the angle of the ultrasonic probe with respect to the cartilage surface or the subchondral bone surface calculated by the angle calculation unit, the angle of the ultrasonic probe can be easily adjusted.

The ultrasonic analysis method according to the present invention includes a transmission control step, an echo data input step, a position detection step, a shape detection step, and an angle calculation step. In the transmission control step, an ultrasonic signal is controlled from the ultrasonic source to a plurality of different positions on the cartilage surface or the subchondral bone surface inside the subject with a predetermined sound axis by controlling the ultrasonic source. Send it. The echo data input step receives the input of echo data of an echo signal obtained by reflecting the ultrasonic signal transmitted in the control transmission step inside the subject. The position detecting step detects positions of the plurality of cartilage surfaces or the subchondral bone surfaces different from the ultrasonic source. The shape detection step detects the shape of the cartilage surface or the subchondral bone surface based on the information on each position detected in the position detection step. The angle calculation step calculates an angle formed by a normal direction of the cartilage surface or the subchondral bone surface at the position where the ultrasonic signal is transmitted and the sound axis of the ultrasonic signal.

This ultrasonic analysis method is performed by the above ultrasonic analysis apparatus. Therefore, this ultrasonic analysis method has the same effect as the above ultrasonic analysis apparatus.

Further, the ultrasonic analysis program according to the present invention controls the ultrasonic source so that the ultrasonic source is directed toward a plurality of different positions on the cartilage surface or subchondral bone surface inside the subject. A transmission control step for transmitting an ultrasonic signal with a predetermined sound axis from an echo, and an echo that receives an input of echo data of an echo signal obtained by reflecting the ultrasonic signal transmitted by the transmission control step inside the subject Based on the data input step, the position detection step for detecting the positions of the plurality of different cartilage surfaces or the subchondral bone surfaces different from the ultrasonic source, and information on each position detected in the position detection step A shape detecting step for detecting a shape of the cartilage surface or the subchondral bone surface, and the cartilage surface at the position where the ultrasonic signal is transmitted or Serial and angle calculation step of calculating the angle formed the acoustic axis in the normal direction and the ultrasonic signal subchondral bone surface, to function as a.

This ultrasonic analysis program is a program installed in the ultrasonic analysis apparatus. Therefore, this ultrasonic analysis program has the same effect as the ultrasonic analysis apparatus.

According to the present invention, since the user can grasp the angle of the ultrasonic probe with respect to the cartilage surface or the subchondral bone surface, the contact angle of the ultrasonic probe to the subject can be easily adjusted.

The block diagram which shows the structure of the ultrasonic analyzer which concerns on embodiment The figure which shows the ultrasonic probe and subject of the ultrasonic analyzer which concern on embodiment Diagram showing image data generated from amplitude data Figure showing image data generated from amplitude data after moving average processing The figure which displayed the image data produced | generated from the amplitude data Dcomp (x, z) after a compressor process The figure for explaining the method of detecting the surface position of the cartilage Diagram showing image data generated based on cost map The figure which shows an example of the display of a contact angle guide Flowchart of contact angle calculation processing executed by the ultrasonic analyzer Flow chart of surface position detection process of subchondral bone Flow chart of cartilage surface position detection process

FIG. 1 is a block diagram showing a configuration of an ultrasonic analysis apparatus 10 according to the present embodiment. FIG. 2 is a diagram illustrating the ultrasonic probe 100 and the subject of the ultrasonic analysis apparatus 10 according to the present embodiment. In the present embodiment, an ultrasonic analysis apparatus 10, an ultrasonic analysis method, and an ultrasonic analysis program that analyze the inside of a human knee as an example of a subject will be described.

The ultrasonic analyzer 10 includes an ultrasonic probe 100. The ultrasonic probe 100 is a single transducer (ultrasonic source) that is mechanically scanned in a two-dimensional manner along the surface of the subject, for example, the knee (x-direction and y-direction scanning directions shown in FIG. 2). )have. The vibrator transmits an ultrasonic signal from the surface of the subject toward the inside of the subject at a predetermined time interval. The transmitted ultrasonic signal is reflected inside the subject, and the transducer receives the reflected echo signal.

The ultrasonic probe 100 is not limited to the above-described configuration. For example, the ultrasonic probe 100 includes a plurality of transducers arranged in one direction (for example, the x direction shown in FIG. 2) and scans in a two-dimensional manner. It may be a configuration. In the case of this configuration, the user moves the ultrasonic probe 100 in a direction (y direction) orthogonal to the one direction, and the ultrasonic analysis apparatus 10 receives an ultrasonic signal having a predetermined transmission beam angle of the subject. An echo signal transmitted from the surface and reflected inside the subject is received.

As shown in FIG. 2, the ultrasonic analysis device 10 causes the knee surface (surface of the soft tissue 903) 905 to abut the end surface on the transmission / reception surface side of the ultrasonic probe 100, transmits an ultrasonic signal, and Explore the inside. The soft tissue 903 is a part inside the body including skin and muscles, and is a part that exists on the surface side of the subject with respect to the cartilage 901. The cartilage 901 is attached to the subchondral bone 904, and the subchondral bone 904 is a tissue connected to the bone (cancellous bone) 902. Hereinafter, a direction from the knee surface 905 toward the inside of the bone 902 side is referred to as a depth direction, and this direction is referred to as a z direction (a direction orthogonal to the x direction and the y direction).

The ultrasonic signal transmitted from the transducer of the ultrasonic probe 100 in the depth direction is reflected inside the subject (for example, soft tissue 903 or bone 902). The transducer of the ultrasonic probe 100 receives the reflected echo signal. The ultrasonic analysis device 10 generates image data of the cartilage 901 and the like based on the echo signal received by the ultrasonic probe 100. The ultrasonic analysis apparatus 10 displays this image data on a monitor (not shown) or the like, and allows the user to determine the state of the cartilage 901 or the like.

When transmitting an ultrasonic signal to the inside of the subject, the sound axis (not shown) of the ultrasonic signal is the surface of the cartilage 901 (hereinafter referred to as the cartilage surface) or the surface of the subchondral bone 904 (hereinafter referred to as the cartilage surface). The contact angle of the ultrasound probe 100 (the angle of the sound axis) is adjusted so that the ultrasound probe 100 is substantially perpendicular (within a predetermined angle range) to the subchondral bone surface). It is preferable to contact 905. The ultrasonic analysis apparatus 10 according to the present embodiment has a function that can easily adjust the contact angle of the ultrasonic probe 100. The function will be described in detail below.

The ultrasonic analysis apparatus 10 includes an operation unit 11, a control unit 12, a transmission / reception unit 13, and a signal processing unit 14.

The operation unit 11 receives a user operation input, and includes, for example, a key, a mouse, a touch panel, and the like. In the present embodiment, the operation unit 11 includes a plurality of operators (not shown). The control unit 12 receives an instruction relating to the start of execution of the cartilage analysis process or the like by an operation on the operation element. Note that the ultrasonic analysis apparatus 10 (control unit 12) may be configured not to include the operation unit 11 and to receive an operation instruction from the outside.

The control unit 12 is configured by a processor such as a CPU, for example, and controls the operation of the ultrasonic analysis apparatus 10. For example, when receiving an instruction to start execution of a predetermined process such as a cartilage analysis process from the operation unit 11, the control unit 12 instructs the transmission / reception unit 13 and the signal processing unit 14 to start processing.

In addition, the control unit 12 controls the ultrasonic source (vibrator) of the ultrasonic probe 100 to direct the ultrasonic source toward a plurality of different positions on the surface of the cartilage or the subchondral bone inside the subject. To transmit an ultrasonic signal with a predetermined sound axis. For example, the control unit 12 controls the position of the transducer of the ultrasonic probe 100 with respect to the subject, or controls the transmission angle of the ultrasonic signal with respect to the subject of the ultrasonic source, thereby controlling the inside of the subject. The ultrasonic signal is transmitted to a plurality of different positions on the cartilage surface or subchondral bone surface.

When the start of processing is instructed from the control unit 12, the transmission / reception unit 13 generates an ultrasonic wave generation signal obtained by shaping a carrier wave having a frequency in the ultrasonic band into a pulse shape. Then, the transmission / reception unit 13 outputs an ultrasonic wave generation signal to the ultrasonic probe 100. Thereby, an ultrasonic signal is transmitted from the transducer of the ultrasonic probe 100 to the inside of the subject in the depth direction.

Further, the transmission / reception unit 13 converts the echo signal from the inside of the subject received by the transducer of the ultrasonic probe 100 into discrete data by sampling at a predetermined time interval. The echo signal converted into discrete data becomes echo data. Thereby, echo data sampled at predetermined intervals in the depth direction can be obtained. Further, for each of the x direction and the y direction, the transmission / reception unit 13 performs envelope amplitude data D (x, z), D (y, z) obtained by performing envelope detection processing and log compression processing on the echo data. Is generated. FIG. 3 is a diagram showing image data generated from the amplitude data D (x, z).

The signal processing unit 14 includes a computer including a processor such as a CPU, for example, and includes an echo data input unit 141, a position detection unit 142, a shape detection unit 143, an angle calculation unit 144, and an image data generation / output unit 145. And a notification unit 146 and a determination unit 147.

The echo data input unit 141 is composed of an input interface (I / F), for example, and receives echo data such as amplitude data generated by the transmission / reception unit 13. The signal processing unit 14 includes a storage unit (not shown) configured from a memory or the like. The storage unit performs echo analysis generated by the transmission / reception unit 13, each data generated by another processing unit such as the position detection unit 142, and ultrasonic analysis for executing various processes related to the ultrasonic analysis method described later according to the present invention. Stores programs and the like.

The position detection unit 142 calculates the distance (ultrasonic propagation time) between the transducer (ultrasonic source) of the ultrasonic probe and the cartilage surface or the subchondral bone surface based on the echo data from the transmission / reception unit 13. Thus, the position of the cartilage surface or subchondral bone surface is detected (in other words, the time position of the cartilage surface or subchondral bone surface is calculated, and the cartilage surface or subchondral bone surface is calculated based on the assumed sound speed. Is detected). The position detection unit 142 includes a subchondral bone surface position detection unit 142A and a cartilage surface position detection unit 142B.

The subchondral bone surface position detection unit 142A uses the amplitude data D (x, z) and D (y, z) generated by the transmission / reception unit 13, and the surface position of the subchondral bone 904 in the z direction with respect to the x direction, And the surface position of the subchondral bone 904 in the z direction with respect to the y direction is detected. The surface position of the subchondral bone 904 is a boundary position between the cartilage 901 and the subchondral bone 904. Hereinafter, a method for detecting the surface position of the subchondral bone 904 in the z direction with respect to the x direction will be described.

The subchondral bone surface position detection unit 142A takes a moving average of the amplitude data D (x, z) and generates smooth amplitude data Dm (x, z). In this case, even if the continuity of the amplitude data in the scanning direction and the depth direction is poor, the surface position of the subchondral bone 904 can be easily detected by smoothing. FIG. 4 is a diagram showing image data generated from the amplitude data Dm (x, z) after the moving average processing.

The subchondral bone surface position detection unit 142A performs a compressor process for suppressing the signal intensity exceeding a predetermined value level to a predetermined value level or less from the amplitude data Dm (x, z), and the amplitude data Dcomp (x, z) Generate. Thereby, unnecessary high echo amplitude such as noise can be suppressed. FIG. 5 is a diagram showing image data generated from the amplitude data Dcomp (x, z) after the compressor processing.

Note that the subchondral bone surface position detection unit 142A may thin the number of data from the amplitude data Dm (x, z) after the moving average process in order to shorten the subsequent calculation processing time. Further, the subchondral bone surface position detection unit 142A causes the storage unit to store the generated amplitude data as needed.

The subchondral bone surface position detection unit 142A uses the amplitude data Dcomp (x, z) to create a cost map by the method described below, and detects the surface position of the subchondral bone 904 in the depth direction. As shown in FIG. 5, the subchondral bone surface position detection unit 142A sets two regions Nfw and Nbw adjacent along the depth direction. The region Nbw is located on the skin side in the depth direction, and the region Nbw is a region located on the inner side (bone side) than the region Nbw. Further, the sizes of the areas Nfw and Nbw to be set can be changed as appropriate.

Each of the regions Nfw and Nbw includes a plurality of amplitude data Dcomp (x, z). The subchondral bone surface position detection unit 142A calculates the average value of the amplitude levels from the amplitude data Dcomp (x, z) in the regions Nfw and Nbw. Then, the average value of the amplitude level in the region Nbw is subtracted from the average value of the amplitude level in the region Nfw. The subchondral bone surface position detection unit 142A stores the calculation result in the storage unit as a cost map.

It should be noted that the subchondral bone surface position detection unit 142A may detect the position of the subchondral bone 904 by the Dijkstra method (minimum cost path search). For example, position detection is performed in the order of a plurality of different positions x1, x2, x3 in the x direction. For example, when position detection is performed at the position x2, from the surface position of the subchondral bone 904 detected at the immediately preceding x1, A predetermined range is set in the depth direction, and the surface position of the subchondral bone 904 is detected in the range. Thereby, the search time can be shortened and erroneous detection can be suppressed.

When an ultrasound signal is transmitted to the subject knee, the ultrasound signal is not reflected inside the cartilage 901, and the echo signal is reflected by the subchondral bone 904, whereas the echo signal is minute or no echo (signal). The echo signal has a high amplitude. Therefore, for example, when one of the regions Nfw and Nbw is located in the cartilage 901, the difference between the average values of the amplitude levels is large. On the other hand, the difference between the average values of the amplitude levels when the regions Nfw and Nbw are not located in the cartilage 901 is small. Using this, the subchondral bone surface position detection unit 142A detects a position with a large difference from the cost map stored in the storage unit as the surface position of the subchondral bone 904 in the depth direction.

The cartilage surface position detection unit 142B detects the surface position of the cartilage 901 in the depth direction, more specifically, the boundary position between the cartilage 901 and the soft tissue 903. Similarly to the subchondral bone surface position detection unit 142A, the cartilage surface position detection unit 142B detects the surface position of the cartilage 901 in each of the x and y directions. A method for detecting the surface position 901 will be described.

FIG. 6 is a diagram for explaining a method for detecting the surface position of the cartilage 901. FIG. 6 shows a part of the image shown in FIG.

The cartilage surface position detection unit 142B extracts the amplitude data Dcomp (x, z) included in the predetermined region from the storage unit. The predetermined region is a region having a thickness Th on the soft tissue 903 side in the depth direction from the surface position of the subchondral bone 904 detected by the subchondral bone position detection unit 142A. The thickness Th is a maximum value of the thickness of a human measurement site (cartilage) that is generally assumed. Then, the cartilage surface position detection unit 142B determines the search range in the depth direction according to the assumed maximum value of the cartilage thickness. That is, the cartilage surface position detection unit 142B sets two regions Cfw and Cbw from the extracted amplitude data Dcomp (x, z) in the same manner as described in FIG. Then, the cartilage surface position detection unit 142B calculates the difference between the average values of the amplitude levels in the regions Cfw and Cbw, and stores the calculation result in the storage unit as cost map data.

As described above, the ultrasonic signal is not reflected at the cartilage 901 portion, and becomes an echo-free signal. Then, similarly to the method for detecting the position of the subchondral bone 904 by the subchondral bone surface position detection unit 142A, the cartilage surface position detection unit 142B determines the position where the difference is large from the cost map data stored in the storage unit. The surface position of the cartilage 901 in the direction is detected. FIG. 7 is a diagram showing image data generated based on the cost map. The cartilage surface position detection unit 142B detects the surface position of the cartilage 901 in each of the x and y directions, and obtains information Z (x, y) of the three-dimensional coordinates of the surface position of the cartilage 901.

The shape detection unit 143 detects the shape of the cartilage surface or the subchondral bone surface based on the information on each position detected by the position detection unit 142. The shape detection unit 143 calculates the plane of the cartilage surface or the subchondral bone surface (detects the shape) by performing surface fitting on the three-dimensional information Z (x, y) obtained by the position detection unit 142. For this surface fitting, for example, a least square method is used.

The angle calculation unit 144 calculates the angle formed by the normal direction of the cartilage surface or subchondral bone surface at the position where the ultrasonic signal is transmitted and the sound axis of the ultrasonic signal. That is, the angle calculation unit 144 detects a normal vector corresponding to the position where the calculated ultrasonic signal of the plane is transmitted. As described above, it is preferable that the ultrasonic probe 100 is brought into contact with the surface of the knee so that the sound axis of the ultrasonic signal is substantially perpendicular to the surface of the cartilage 901. For this reason, it is preferable that the detected normal vector is parallel to the depth direction. Therefore, the angle calculation unit 144 calculates the angles θx and θy of the normal vector with respect to the depth direction. The angle θx is a moment in the x direction, and the angle θy is a moment in the y direction. These angles θx and θy are incident angles of the sound axis of the ultrasonic signal with respect to the cartilage surface of the cartilage 901.

The image data generation / output unit 145 generates image data for displaying the angles θx and θy calculated by the angle calculation unit 144 on a monitor (not shown), and outputs the image data to the monitor. FIG. 8 is a diagram illustrating an example of the display of the contact angle guide. On the screen, the θx axis, the θy axis, the allowable range 101, and the angle pointer 102 are displayed. The angle pointer 102 indicates the current angle of the ultrasonic probe 100. Based on whether or not the angle pointer 102 is within the allowable range 101, the user can grasp whether or not the angle of the ultrasonic probe 100 with respect to the knee surface is appropriate. The user can transmit an ultrasonic signal substantially perpendicular to the surface of the cartilage 901 by adjusting the angle of the ultrasonic probe 100 so that the angle pointer 102 falls within the allowable range 101. .

It should be noted that the numerical range of the allowable range 101 can be appropriately changed within a range in which cartilage analysis using an ultrasonic signal is normally performed. In addition to the image shown in FIG. 8, an image (so-called B-mode image) in which the amplitude of the echo signal is displayed as the brightness (luminance) of the point may be displayed on the monitor.

The notification unit 146 indicates the detection result (for example, whether or not the angle of the ultrasonic probe 100 is included in the predetermined angle range or information on the angle of the ultrasonic probe 100) by sound or light. A notification signal to be notified is generated. Based on a notification signal from the notification unit 146, a notification device (not shown) such as a speaker or LED notifies the user of the notification signal. Thereby, the user can further easily adjust the angle of the ultrasonic probe.

The determination unit 147 determines whether or not the angle detected by the angle calculation unit 144 is within a predetermined angle range. The determination unit 147 compares the position of the angle pointer 102 with the position of the allowable range 101. If the position of the angle pointer 102 is in the position of the allowable range 101, the angle detected by the angle calculation unit 144 is the predetermined angle range. Is determined to be within.

FIG. 9 is a flowchart of the contact angle calculation process executed by the ultrasonic analysis apparatus 10, and is a flowchart of the ultrasonic analysis method.

When the control unit 12 receives an instruction to start execution of a predetermined process such as a cartilage analysis process through the operation of the operation unit 11, the ultrasonic analysis apparatus 10 starts the predetermined process shown in FIG. First, the transmission / reception unit 13 (control unit 12) transmits an ultrasonic signal from the transducer (ultrasonic source) of the ultrasonic probe 100 (transmission control step), and an echo signal of the ultrasonic signal received by the ultrasonic probe 100. Echo data (for example, amplitude data) is generated from the data and stored in the storage unit (S1). The echo data input unit 141 receives the amplitude data (S2: echo data input step). Using this amplitude data, the position detector 142 (subchondral bone surface position detector 142A and cartilage surface position detector 142B) detects the surface positions of the subchondral bone 904 and cartilage 901 (S3 and S4: Position detection step).

FIG. 10 is a flowchart of the surface position detection process of the subchondral bone 904.

The cartilage surface position detection unit 142B takes a moving average of the amplitude data (S11). Next, the subchondral bone surface position detection unit 142B thins out the number of amplitude data after moving average, and performs noise level detection (S12). Noise level detection refers to, for example, amplitude data corresponding to no-echo (or micro-echo) data in a region deviated from a position such as cartilage 901 in the depth direction generally assumed from amplitude data corresponding to echo data. delete. Thereby, shortening of processing time etc. can be aimed at.

The cartilage surface position detection unit 142B performs a compressor process for suppressing the signal intensity of echo data exceeding a predetermined value level to a predetermined value level or less (S13). Thereafter, the cartilage surface position detection unit 142B generates a cost map using the amplitude data after the compressor processing (S14). The method for generating the cost map is as described above. The subchondral bone surface position detection unit 142B stores the generated cost map data in the storage unit.

The subchondral bone surface position detection unit 142A detects the surface position of the subchondral bone 904 from the generated cost map by the Dijkstra method (S15). The subchondral bone surface position detection unit 142A stores the detected surface position of the subchondral bone 904 in the storage unit.

Referring back to FIG. 9, as described above, the cartilage surface position detection unit 142B detects the surface position of the cartilage 901 (S4). FIG. 11 is a flowchart of the surface position detection process of the cartilage 901.

The cartilage surface position detection unit 142B obtains amplitude data (echo data) included in a predetermined region based on the surface position of the subchondral bone 904 detected by the subchondral bone surface position detection unit 142A in the process shown in FIG. Then, it is extracted from the storage unit (S21). The amplitude data extracted here is amplitude data generated by the transmission / reception unit 13 and stored in the storage unit. Further, as described in FIG. 6, the predetermined region is a region having a thickness Th on the soft tissue 903 side in the depth direction from the surface position of the subchondral bone 904 detected by the subchondral bone surface position detection unit 142B. is there.

The cartilage surface position detection unit 142B takes a moving average of the extracted amplitude data (S22) and thins out the number of data (S23). Note that the cartilage surface position detection unit 142B may perform noise level detection after the thinning-out process, similarly to the subchondral bone surface position detection unit 142A. Then, the cartilage surface position detection unit 142B performs a compressor process for suppressing the signal intensity exceeding the predetermined value level to be equal to or lower than the predetermined value level (S24). Thereafter, the cartilage surface position detection unit 142B generates a cost map (S25). Then, the cartilage surface position detection unit 142B detects the surface position of the cartilage 901 from the generated cost map by the Dijkstra method (S26).

Returning to FIG. 9, the shape detection unit 143 calculates a plane (detects a shape) by performing surface fitting to the three-dimensional information Z (x, y) obtained by the cartilage surface position detection unit 142B (S5: shape detection step). ).

Next, the angle calculation unit 144 detects the normal vector of the calculated plane (shape), and the angle of the normal vector with respect to the depth direction (the surface of the cartilage surface or the subchondral bone surface at the position irradiated with the ultrasonic signal). Angles θx and θy formed between the normal direction and the sound axis of the ultrasonic signal are calculated (S6: angle calculation step). Then, the image data generation / output unit 145 generates image data for displaying the calculated angles θx, θy, etc. on the monitor (S7: angle display step). Thereby, the image shown in FIG. 8 is displayed on the monitor.

In the present embodiment, the ultrasonic analysis device 10 detects the surface position of the cartilage 901 and detects the angle of the sound axis of the ultrasonic signal with respect to the surface position. The angle of the sound axis of the ultrasonic signal may be detected. In the present embodiment, the ultrasonic analysis device 10 displays the angles θx and θy as images and notifies the user, but may notify the user by sound or light via the notification unit 146.

Also, the ultrasonic analysis apparatus 10 may be configured to generate and output image data only when the determination unit 147 determines that the angle detected by the angle calculation unit 144 is within a predetermined angle range. With this configuration, image data such as cartilage with higher accuracy can be obtained, and the user can more accurately analyze the state of cartilage.

Cbw, Cfw ... area Nbw, Nfw ... area 10 ... ultrasound analyzer 11 ... operating section 12 ... control section 13 ... transmitting / receiving section 14 ... signal processing section 100 ... ultrasonic probe 101 ... allowable range 102 ... angle pointer 141 ... echo data Input unit 142 ... surface position detection unit 142A ... subchondral bone surface position detection unit 142B ... cartilage surface position detection unit 143 ... shape detection unit 144 ... angle calculation unit 145 ... image data generation / output unit 146 ... notification unit 147 ... determination unit 901 ... Cartilage 902 ... Bone 903 ... Soft tissue 904 ... Subchondral bone 905 ... Knee surface

Claims

A control unit for controlling the ultrasonic source to transmit ultrasonic signals from the ultrasonic source to a plurality of different positions on the cartilage surface or subchondral bone surface inside the subject with a predetermined sound axis; ,
An echo data input unit that receives an input of echo data of an echo signal in which the ultrasonic signal transmitted by the control unit is reflected inside the subject;
A position detector for detecting positions of the ultrasonic source and the plurality of different cartilage surfaces or subchondral bone surfaces different from each other;
A shape detection unit that detects the shape of the cartilage surface or the subchondral bone surface based on the information of each position detected by the position detection unit;
An angle calculation unit that calculates an angle formed by a normal direction of the cartilage surface or the subchondral bone surface at the position where the ultrasonic signal is transmitted and a sound axis of the ultrasonic signal;
An ultrasonic analysis apparatus comprising:
The ultrasonic analysis apparatus according to claim 1,
The control unit controls the position of the ultrasound source with respect to the subject, or controls the transmission angle of the ultrasound signal with respect to the subject of the ultrasound source, thereby controlling the inside of the subject. An ultrasonic analysis apparatus that transmits the ultrasonic signals to a plurality of different positions on the surface of the cartilage or the subchondral bone in the body.
The ultrasonic analysis apparatus according to claim 1 or 2, wherein
An ultrasonic analysis apparatus further comprising a notification unit that notifies a detection result by the angle calculation unit.
The ultrasonic analysis apparatus according to any one of claims 1 to 3,
An ultrasonic analysis apparatus further comprising: a determination unit that determines whether the angle detected by the angle calculation unit is within a predetermined angle range.
The ultrasonic analysis apparatus according to claim 1, wherein:
The shape detector
A signal level in a first region composed of echo signals of a plurality of samples in a depth direction from the ultrasonic source toward the inside of the subject and in a direction orthogonal to the depth direction, and in the first region in the depth direction From the difference in signal level of the echo signal in the adjacent second region, search for the cartilage surface or the subchondral bone surface,
The angle calculator is
An angle is detected using a search result by the shape detection unit.
Ultrasonic analyzer.
The ultrasonic analyzer according to claim 5,
The shape detector
In accordance with the maximum thickness of the cartilage at the assumed measurement site in the depth direction, the search range in the depth direction is determined.
Ultrasonic analyzer.
The ultrasonic analysis apparatus according to any one of claims 1 to 6,
The position detector is
Suppressing the signal level of the echo signal exceeding a predetermined value below the predetermined value;
The angle calculator is
Using the echo data of the echo signal after suppression by the position detection unit, the angle is detected.
Ultrasonic analyzer.
A transmission control step of controlling the ultrasonic source to transmit ultrasonic signals from the ultrasonic source to a plurality of different positions on the cartilage surface or subchondral bone surface inside the subject with a predetermined sound axis. When,
An echo data input step for receiving an input of echo data of an echo signal obtained by reflecting the ultrasonic signal transmitted by the transmission control step inside the subject;
A position detecting step for detecting positions of the ultrasonic source and the plurality of different cartilage surfaces or subchondral bone surfaces;
A shape detection step of detecting the shape of the cartilage surface or the subchondral bone surface based on the information of each position detected in the position detection step;
An angle calculation step of calculating an angle formed by a normal direction of the cartilage surface or the subchondral bone surface at the position where the ultrasonic signal is transmitted and a sound axis of the ultrasonic signal;
An ultrasonic analysis method comprising:
Computer
A transmission control step of controlling the ultrasonic source to transmit ultrasonic signals from the ultrasonic source to a plurality of different positions on the cartilage surface or subchondral bone surface inside the subject with a predetermined sound axis. When,
An echo data input step for receiving an input of echo data of an echo signal obtained by reflecting the ultrasonic signal transmitted by the transmission control step inside the subject;
A position detecting step for detecting positions of the ultrasonic source and the plurality of different cartilage surfaces or subchondral bone surfaces;
A shape detection step of detecting the shape of the cartilage surface or the subchondral bone surface based on the information of each position detected in the position detection step;
An angle calculation step of calculating an angle formed by a normal direction of the cartilage surface or the subchondral bone surface at the position where the ultrasonic signal is transmitted and a sound axis of the ultrasonic signal;
Ultrasonic analysis program to function as