JP2020130597A - Method and measurement apparatus for acquiring three-dimensional reflection image inside measurement object - Google Patents

Abstract

To acquire a three-dimensional reflection image inside a measurement object as a high-accuracy 3D image.SOLUTION: A method and an apparatus for acquiring a three-dimensional reflection image include: contacting an ultrasound probe having three or more transducers with a measurement object; causing each of the transducers to sequentially project an ultrasound wave to inside the measurement object and causing two or more transducers to receive reflected wave of the ultrasound wave projected from each of the transducers and reflected from the measurement object projected with ultrasound waves, as reception data set for each of the transducers; and generating a three-dimensional reflection image of the inside of the measurement object by applying an aperture synthesis method on the basis of the obtained reception data sets. Each of the reception data sets includes position data, ultrasound wave arrival time, and received ultrasound intensity data.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for acquiring a three-dimensional reflection image inside an object to be measured and a device for measuring such a three-dimensional reflection image.

In ultrasonic measurement, an object to be measured is irradiated with ultrasonic waves, and a response from the object to be measured is detected for analysis. Ultrasonic measurement is an excellent measurement method in that there is often no or very small damage to the object to be measured. Normally, the ultrasonic probe is brought into contact with the object to be measured, and the vibration element built in the ultrasonic probe irradiates the object to be measured with ultrasonic waves. When the response from the object to be measured is vibration information such as ultrasonic waves, the vibration element is often used as a passive element.

When the object to be measured is irradiated with ultrasonic waves, variations such as reflection, transmission, and interference of the ultrasonic waves are assumed depending on the physical properties of the object to be measured. It is proposed to estimate the internal structure and physical properties of the object to be measured by observing these displacements and processing the data obtained by the observation. For example, Patent Document 1 discloses an invention in which an ultrasonic diagnostic apparatus including a probe receives ultrasonic waves reflected in a subject via the probe.

Japanese Patent No. 6145202

Measurement and diagnosis by ultrasonic waves are excellent measurement and diagnostic methods because there is often no or little destruction of the object to be measured, and further expansion of application is desired. From such a viewpoint, the internal state of the object to be measured can be measured with high accuracy, and the result can be obtained as a three-dimensional stereoscopic image (3D image) so that diagnosis and explanation to the subject can be facilitated. Is desirable. An object of the present invention is to provide a method for acquiring a three-dimensional reflected image and a measuring device capable of obtaining a reflected image of ultrasonic waves as a highly accurate and 3D image.

As a result of diligent studies by the present inventors, the following invention has been completed.
(1) (A) An ultrasonic probe having at least the first to first M (where M is an integer of 3 or more) is brought into contact with the measurement object, and (B) the ultrasonic probe of the said ultrasonic probe. Ultrasonic waves are sequentially applied to the inside of the object to be measured from the first vibrating element to the Nth vibrating element (where N is an integer of 2 or more and M or less), and the supersonic wave from the measurement object is emitted. The reflected wave of the sound wave is received by two or more of the vibrating elements of the ultrasonic probe as the first to Nth reception data set for each irradiated vibrating element, and (C) the first to the first. It is a method of acquiring a three-dimensional reflection image inside a measurement object including generating a three-dimensional reflection image inside the measurement object by applying an aperture synthesis method based on the received data set of N. The first to Nth reception data sets include at least the position data of the irradiated vibrating element, the position data of the received vibrating element, the arrival time from irradiation to reception, and the intensity data of the received ultrasonic waves, respectively. , The method of acquiring the above-mentioned three-dimensional reflection image.
(2) The method of (1) in which M and N are integers of 200 or more.
(3) The method (1) or (2), wherein the ultrasonic probe is configured so that the first to Mth vibrating elements can form a concave curved surface with respect to the object to be measured.
(4) The methods (1) to (3), wherein the object to be measured is a living body.
(5) The vibrating element of the ultrasonic probe changes the transmission and reception positions on a concave curved orbit designed in advance, reconstructs the image by aperture synthesis in the relationship of different positions and angles, and from irradiation to reception. How to calculate the arrival time of and the intensity data of the received ultrasonic waves.
(6) An ultrasonic probe having at least the first to first M (where M is an integer of 3 or more), a control device, and an output device are provided, and the control device includes the following (B). ) And (C), (B) In a state where the ultrasonic probe is in contact with the object to be measured, the Nth from the first vibrating element of the ultrasonic probe (where N is an integer of 2 or more and N or less). The ultrasonic waves are sequentially irradiated to the inside of the object to be measured up to the vibrating element of (.), and the reflected wave of the ultrasonic wave from the object to be measured is the first to Nth received data for each irradiated vibrating element. Measurement target by receiving as a set with two or more vibrating elements among the vibrating elements of the ultrasonic probe, and (C) applying the aperture synthesis method based on the first to Nth received data sets. It is configured to generate a three-dimensional reflection image inside an object, and the output device outputs the three-dimensional reflection image generated in the above (C), and the first to Nth Each of the received data sets of is inside the object to be measured, including at least the position data of the irradiated vibrating element, the position data of the received vibrating element, the arrival time from irradiation to reception, and the intensity data of the received ultrasonic wave. A measuring device for a three-dimensional reflection image.
(7) The measuring device of (6) in which M and N are integers of 200 or more.
(8) The measuring device according to (6) or (7), wherein the ultrasonic probe is configured so that the first to Mth vibrating elements can form a concave curved surface with respect to the object to be measured.
(9) The measuring devices of (6) to (8), wherein the object to be measured is a living body.

According to the present invention, ultrasonic waves are irradiated to a measurement object from a plurality of irradiation points, and the reflection data thereof are integrated by an aperture synthesis method, whereby the inside of the measurement object is highly accurate and three-dimensional. Can be described in.

It is a schematic diagram of an example of an ultrasonic probe that can be used in the present invention. It is explanatory drawing of the definition of coordinates in the aperture synthesis method. It is a schematic explanatory diagram of the calculation of a delay. It is a schematic explanatory diagram of high quality full dynamic focus image generation.

Hereinafter, the present invention will be described with reference to the drawings as appropriate. The present invention is not limited to the illustrated embodiments.

According to the present invention, a device for measuring a three-dimensional reflection image inside a measurement object includes an ultrasonic probe having three or more vibration elements, a control device, and an output device. The control to be performed in the control device will be described later.

For convenience, the three or more vibrating elements of the ultrasonic probe are referred to as the first to Mth (where M is an integer of 3 or more) vibrating elements. The configuration of the ultrasonic probe itself is not particularly limited, and conventionally known ones can be used as they are. As a non-limiting example, FIG. 1 shows a schematic diagram of an example of an ultrasonic probe. FIG. 1A is an external perspective view, and FIG. 1B is an internal schematic view of a probe body.

When measuring the object to be measured (not shown), the probe body 12 of the ultrasonic probe 10 is brought into contact with the surface of the object to be measured U. The probe main body 12 includes first to M first vibrating elements 11. A transmission signal is transmitted from a control device or the like (not shown) to each vibrating element 11 of the probe main body 12 via the transmission unit 13. Ultrasonic waves are emitted from the vibrating element 11 based on this transmission signal.

In the present invention, as the vibrating element itself, a conventionally known one can be used as it is. The vibrating element used in the conventional ultrasonic probe can be appropriately adopted.

Preferably, the vibrating element is configured to be capable of forming a concave curved surface with respect to the object to be measured. For example, in the ultrasonic probe as shown in FIG. 1, the probe main body 12 forms a concave curved surface, and the vibrating element 11 is incorporated therein, so that the plurality of vibrating elements 11 as a whole are objects to be measured. It forms a concave curved surface.

The material of the probe main body 12 is not particularly limited, and a known material can be appropriately used. The means for incorporating the plurality of vibrating elements 11 into the probe main body 12 is also not particularly limited, and the conventional invention of the ultrasonic probe can be appropriately referred to.

At the time of measurement, such an ultrasonic probe is brought into contact with the object to be measured. Next, ultrasonic waves are sequentially applied to the inside of the object to be measured from the first vibrating element of the ultrasonic probe. For convenience, the ultrasonic waves that irradiate the ultrasonic waves are referred to as the first vibrating element to the Nth vibrating element. Here, N is an integer of 2 or more and M or less. When N = M, it means that ultrasonic waves are sequentially irradiated from all the vibrating elements of the ultrasonic probe.

From the viewpoint of improving the measurement accuracy, M and N are preferably 200 or more. Suitable upper limits of M and N are not particularly defined, but 512 is exemplified without limitation.

When ultrasonic waves are applied to the inside of the object to be measured, the ultrasonic waves are reflected according to the internal structure and physical properties of the object to be measured. According to the present invention, the reflected ultrasonic waves are received by two or more vibrating elements included in the ultrasonic probe. Preferably, the ultrasonic waves reflected by all the vibrating elements other than the vibrating element irradiated with the ultrasonic waves are received.

The received ultrasonic signal is called a received data set for convenience. The received data set is also referred to as a first data set, a second data set, ... Nth data set, depending on the number of the irradiated ultrasonic element (first to Nth).

Each dataset should contain at least the following information: The information is the position data of the irradiated vibrating element, the position data of the received vibrating element, the arrival time from the irradiation to the reception, and the intensity data of the received ultrasonic wave. These data will be used to analyze the 3D image inside the object to be measured in the steps described below.

From the first to Nth data sets obtained above, a 3D reflection image inside the measurement object is generated. The 3D reflection image is a three-dimensional image composed of surface information inside the measurement object reconstructed from the reflection data of ultrasonic waves. Reconstructing a three-dimensional image from ultrasonic reflection data itself can appropriately refer to a so-called rendering technique that undergoes operations such as region extraction, mapping, viewing, and shading. According to the present invention, the aperture synthesis method is applied at that time, and it is expected that the resulting 3D reflection image will be highly accurate.

In the aperture synthesis method, as described above, ultrasonic waves are sequentially transmitted from the first to Nth vibrating elements and reflected inside the object to be measured based on the shape discontinuity and the composition difference. Is used. Therefore, it is possible to obtain reflection source images in which shape discontinuities and composition differences that cause ultrasonic reflection are viewed from various directions. As a result, the same data can be obtained from a reflection source whose reflection directivity of ultrasonic waves is strong in a specific direction, such as shape discontinuity, and conversely, the incident / reflection of ultrasonic waves such as a noise source of composition. Signals from highly directional reflection sources tend to cancel each other out and become less noticeable. This means that the S / N ratio of the signal is improved, and contributes to high accuracy of the obtained 3D reflection image.

According to the present invention, the object to be measured is not particularly limited, and is preferably a living body, particularly a human body. For example, the ultrasonic probe may be brought into contact with a human calf or a human thigh.

In the method of the present invention described above, for example, the vibrating element of the ultrasonic probe changes the transmitting and receiving positions in the orbit of a concave curved surface designed in advance, and reconstructs the image by aperture synthesis in the relationship between different positions and angles. It can also be expressed as a method of calculating the arrival time from irradiation to reception and the intensity data of the received ultrasonic waves.

Further, according to the present invention, the measuring device for the three-dimensional reflection image inside the object to be measured includes a control device, and the control device includes the first to M (first to Nth) vibrating elements. In addition to operating so as to irradiate and receive ultrasonic waves as described above, perform an operation to generate a three-dimensional reflection image (3D reflection image) from the obtained first to Nth data sets as described above. It is configured. The generated 3D reflection image is output from the output device. The output device is not particularly limited, such as a monitor, a printer, an external memory, and a wired or wireless transmission means to other devices.

Hereinafter, the above-mentioned contents of the present invention will be introduced more specifically. The following example is not a description for a limited interpretation of the present invention, but is merely an example.

In collecting ultrasonic reflection data, the number of A / D converters in the device can be taken into consideration. For example, if there are 128 A / D converters, it is preferable to set the number M of vibrating elements and the number N of data sets to, for example, about 512. Further, the reflection data may be acquired a plurality of times, for example, about 3 to 6 times.

Aperture synthesis method is used to provide a complete dynamic focus image. As described above, in the ultrasonic irradiation, first, only the first vibrating element is excited to irradiate the ultrasonic wave, and all the vibrating elements other than the first vibrating element are used for data reception. Then, the second, third, ... Nth vibrating element, and so on, are sequentially excited N times until each channel is excited and irradiated with ultrasonic waves. A complete dynamic focus image can be obtained by combining a large number of low resolution images from each irradiation.

In applying the aperture synthesis method, first, the position of the element and the coordinates of the image area are defined. FIG. 2 is an explanatory diagram of the definition of coordinates in the aperture synthesis method. Next, the geometric distance from the vibrating element to the imaging point inside the object to be measured is obtained, and the delay is calculated based on the distance returned to the receiving element. Here, the delay (delay) is calculated with respect to the coordinates of the imaging point (x _image , y _image , z _image ), the coordinates of the receiving element (x _probe , y _probe , z _probe ), and the sound velocity c as follows. To. Note that FIG. 3 is a schematic explanatory diagram for calculating the delay.

Each of the above data constitutes a first to Nth data set.
A large number of low resolution images are then combined to produce a high quality full dynamic focus image. FIG. 4 is a schematic explanatory view of high quality full dynamic focus image generation.

The 3D reflection image obtained by the apparatus and method of the present invention can be used as a basis for various measurements and diagnoses using ultrasonic waves. The measurement and diagnosis using ultrasonic waves are not particularly limited, and the conventional measurement and diagnosis can be appropriately performed. At that time, according to the present invention, high-precision 3D data can be obtained, which can contribute to complicated analysis and high-accuracy / high-precision measurement / diagnosis. From such a viewpoint, the ultrasonic probe of the present invention is particularly preferably used for biometric measurement. The frequency of the ultrasonic wave irradiated at the time of measurement is not particularly limited, and is preferably 3 MHz to 7 MHz.

Further, for example, by saving the received ultrasonic waves (reflected waves, transmitted waves, diffracted waves) as waveform data and comparing them with other data such as CT and MRI, the state and symptoms of the measurement target can be obtained from the waveform data. Applications such as finding features that can be judged are also conceivable. As a result, waveform data with annotations can be created, and it is expected that it will be used as learning data for machine learning.

10 Ultrasonic probe 11 Vibrating element 12 Probe body

Claims (9)

(A) An ultrasonic probe having at least the first to first M (where M is an integer of 3 or more) is brought into contact with the object to be measured.
(B) The inside of the object to be measured is irradiated with ultrasonic waves in order from the first vibrating element of the ultrasonic probe to the vibrating element of the Nth (where N is an integer of 2 or more and N or less). , The reflected wave of the ultrasonic wave from the object to be measured is received by two or more of the vibrating elements of the ultrasonic probe as the first to N reception data sets for each irradiated vibrating element. ,
(C) A three-dimensional reflection image inside the measurement object is generated by applying the aperture synthesis method based on the first to Nth received data sets.
It is a method of acquiring a three-dimensional reflection image inside the measurement object including the above.
The first to Nth reception data sets include at least the position data of the irradiated vibrating element, the position data of the received vibrating element, the arrival time from irradiation to reception, and the intensity data of the received ultrasonic waves, respectively.
A method for acquiring the above three-dimensional reflection image. The method according to claim 1, wherein M and N are integers of 200 or more. The method according to claim 1 or 2, wherein the ultrasonic probe is configured so that the first to third vibrating elements can form a concave curved surface with respect to the object to be measured. The method according to any one of claims 1 to 3, wherein the object to be measured is a living body. The vibrating element of the ultrasonic probe changes the transmitting and receiving positions on a concave curved orbit designed in advance, reconstructs the image by aperture synthesis in the relationship of different positions and angles, and the arrival time from irradiation to reception. And how to calculate the intensity data of the received ultrasonic waves. An ultrasonic probe having at least the first to first M (where M is an integer of 3 or more), a control device, and an output device are provided, and the control device includes the following (B) and ( C),
(B) Vibration of the Nth (where N is an integer of 2 or more and M or less) from the first vibrating element of the ultrasonic probe in a state where the ultrasonic probe is in contact with the object to be measured. Ultrasonic waves are applied to the inside of the object to be measured in sequence up to the element, and the reflected wave of the ultrasonic wave from the object to be measured is used as the first to Nth received data set for each irradiated vibrating element. 3D inside the object to be measured by receiving with two or more vibrating elements among the vibrating elements possessed by, and (C) applying the aperture synthesis method based on the first to Nth received data sets. Generating a reflection image,
Is configured to run
The output device outputs the three-dimensional reflection image generated in (C).
The first to Nth reception data sets include at least the position data of the irradiated vibrating element, the position data of the received vibrating element, the arrival time from irradiation to reception, and the intensity data of the received ultrasonic waves, respectively.
A device for measuring a three-dimensional reflection image inside an object to be measured. The measuring device according to claim 6, wherein M and N are integers of 200 or more. The measuring device according to claim 6 or 7, wherein the ultrasonic probe is configured so that the first to third vibrating elements can form a concave curved surface with respect to the object to be measured. The measuring device according to any one of claims 6 to 8, wherein the object to be measured is a living body.

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