JP2020130599A - Ultrasound measurement method and measurement apparatus for measurement object - Google Patents

Abstract

To provide a method and a measurement apparatus for measuring behaviors of ultrasound waves in a mode different from that of a reflection image.SOLUTION: An ultrasound measurement method and a measurement apparatus for a measurement object include: contacting an ultrasound probe including a projection transducer group having three or more transducers and a reception transducer group having a plurality of transducers with a measurement object such that the ultrasound probe passes through the inside of the measurement object from the projection transducer group to the reception transducer group; causing each of the transducers in the projection transducer group to sequentially project an ultrasound wave to inside the measurement object and causing respective transducers in the reception transducer group to receive the ultrasound wave projected by the respective transducer in the projection transducer group and transmitted through the measurement object as the reception data of each of the projecting transducers; and calculating the intensity attenuation of the ultrasound wave and the propagation velocity of the ultrasound wave at each position inside the measurement object by applying an aperture synthesis method on the basis of the reception data.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for acquiring the attenuation behavior of the velocity and intensity of ultrasonic waves transmitted through the inside of a measurement object, and a measuring device for that purpose.

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, it is preferable that the internal state of the object to be measured can be grasped in various ways. In a relatively large number of cases, so-called reflection images are acquired by observing the reflection behavior of the irradiated ultrasonic waves at each position of the object to be measured. An object of the present invention is to provide a method and a measuring device for grasping the behavior of an ultrasonic wave in a mode different from that of a reflected image.

As a result of diligent studies by the present inventors, the following invention has been completed.
(1) (A) A group of vibration elements for irradiation having first to first M (where M is an integer of 3 or more) and a plurality of vibration elements separately from the group of vibration elements for irradiation. A group of receiving vibrating elements and one or a plurality of ultrasonic probes having are brought into contact with an object to be measured, and at this time, the vibrating elements of the group of vibrating elements for irradiation and the vibrating elements of the group of vibrating receiving elements are brought into contact with each other. The step of bringing the ultrasonic probe into contact with the measurement object so that the connecting straight line passes through the inside of the measurement object, (B) ultrasonic waves are sequentially applied from the first vibration element to the M vibration element. A step of irradiating the inside of the object to be measured and causing the plurality of vibrating elements of the receiving vibrating element group to receive the ultrasonic waves transmitted through the object to be measured as the received data for each vibrating element (C). ) By applying the aperture synthesis method based on the received data, there is a step of calculating the intensity attenuation of the ultrasonic wave and the propagation speed of the ultrasonic wave at each position inside the object to be measured, and each of the above-mentioned receptions. The data includes 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, the intensity data of the irradiated ultrasonic wave, and the intensity data of the received ultrasonic wave. Ultrasonic measurement method for objects.
(2) The method of (1) in which M is an integer of 200 or more.
(3) The method of (1) or (2) in which the object to be measured is a living body.
(4) A group of vibration elements for irradiation having first to third M (where M is an integer of 3 or more) and a reception having a plurality of vibration elements separately from the first group of vibration elements. The control device includes the following (B) and (C), that is, (B) the first, which includes one or a plurality of ultrasonic probes having a vibration element group for vibration, a control device, and an output device. A group of receiving vibrating elements is used to irradiate the inside of the object to be measured with ultrasonic waves in sequence from the vibrating element to the Mth vibrating element, and the ultrasonic waves transmitted through the object to be measured are received as received data for each irradiated vibrating element. By receiving each of the multiple vibrating elements of the device and (C) applying the aperture synthesis method based on the received data, the intensity attenuation of the ultrasonic waves and the propagation of the ultrasonic waves at each position inside the object to be measured The output device is configured to perform the calculation of the velocity, and outputs at least one of the intensity attenuation of the ultrasonic waves generated in (C) and the propagation velocity of the ultrasonic waves. Each received data includes 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, the intensity data of the irradiated ultrasonic waves, and the intensity data of the received ultrasonic waves. , An ultrasonic measuring device for the object to be measured.
(5) The measuring device of (4) in which M is an integer of 200 or more.
(6) The measuring device according to (4) or (5), wherein the object to be measured is a living body.

According to the present invention, ultrasonic waves are applied to a measurement object from a plurality of irradiation points, and the transmission data thereof are integrated by an aperture synthesis method to obtain an ultrasonic wave derived from the internal shape and composition of the measurement object. It is possible to measure the intensity attenuation and propagation speed of ultrasonic waves with high accuracy.

It is a schematic diagram of an example of an ultrasonic probe that can be used in the present invention. 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 analysis of the received data.

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, the ultrasonic measuring device for a measurement object includes an ultrasonic probe having a group of vibrating elements for irradiation and reception, a control device, and an output device. The control to be performed in the control device will be described later. The group of vibrating elements for irradiation and reception may be provided in one ultrasonic probe, or may be dispersed in a plurality of ultrasonic probes.

For convenience, the three or more vibrating elements included in the irradiation vibrating element group are referred to as the first to Mth vibrating elements (where M is an integer of 3 or more). The first to first M vibration elements are vibration elements that irradiate ultrasonic waves at the time of measurement. From the viewpoint of improving the measurement accuracy, M is preferably 32 to 1024, and more preferably 256 to 512.

The plurality of vibrating elements included in the receiving vibrating element group are vibrating elements that receive ultrasonic waves at the time of measurement. From the viewpoint of improving the measurement accuracy, the receiving vibrating element group preferably has 32 to 1024 vibrating elements, more preferably 256 to 512 vibrating elements.

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.

In the present invention, in ultrasonic measurement, the ultrasonic waves emitted from the vibrating elements of the irradiation vibrating element group pass through the inside of the measurement object and are received by the vibrating element of the receiving vibrating element group. To. Therefore, the arrangement of the vibrating elements is such that the straight line connecting the vibrating elements of the irradiation vibrating element group and the vibrating elements of the receiving vibrating element group passes through the inside of the object to be measured. Non-limiting examples of such arrangement of vibrating elements are given below.

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 a transmission unit. Ultrasonic waves are emitted from the vibrating element 11 based on this transmission signal.

The probe of FIG. 1 is configured such that the vibrating element can form a concave curved surface with respect to the object to be measured. 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 form a concave curved surface with respect to the object to be measured. When the probe 10 is brought into contact with the object to be measured so as to wrap the object to be measured with a concave curved surface, a straight line connecting the vibrating element 11a near one end of the concave curved surface and the vibrating element 11b near multiple ends among the plurality of vibrating elements 11 , It will pass inside the object to be measured. Therefore, in the case of the form shown in FIG. 1B, for example, the vibrating element 11a can form the irradiation vibrating element group, and the vibrating element 11b can form the receiving vibrating element group.

Another example of the probe is a form in which a frame is separately provided and the probe main body is movable in the frame. FIG. 2 is a schematic view of one form of the ultrasonic probe of the present invention. The ultrasonic probe 20 is movable with the probe bodies 22 and 23 attached to the frame 24.

In FIG. 2A, the ultrasonic probe 20 is provided with probe main bodies 22 and 23 and a frame 24, and the probe main body 22 and the probe main body 23 are integrally attached to the frame 24. The probe main body 22 is provided with a plurality of vibrating elements 21a, and the probe main body 23 is also provided with a plurality of vibrating elements 22b as indicated by broken lines in the drawings.

Here, the probe main body 22 and the probe main body 23 can be moved along the curved groove 25 provided in the frame 24. By moving the probe body 22 and the probe body 23 in this way, as shown in FIG. 2B, the probe body 22 and the probe body 23 can be separated into separate members, that is, a plurality of members. In such a separated form, it is interpreted that the vibrating element 21a incorporated in the probe main body 22 and the vibrating element 21b incorporated in the probe main body 23 form a concave curved surface as a whole with respect to the object to be measured. can do. By making the probe main body separable in this way, the number of vibrating elements used can be reduced, and the manufacturing cost can be reduced. In addition, when a living body is used as a measurement object, individual differences are expected in the size and shape of the body part, but as shown in the form of FIG. 2, the probe body can be separated for measurement. The probe body can be moved to the optimum position for the individual.

By separating the probe main body 22 and the probe main body 23 into a plurality of members as shown in FIG. 2B, the vibrating element 21a provided on the probe main body 22 and the vibrating element 21b provided on the probe main body 23 are measured. It is in the form of sandwiching an object. Therefore, the straight line connecting the vibrating element 21a and the vibrating element 22b passes through the inside of the object to be measured. Therefore, for example, the vibrating element 221a can be used as the irradiation vibrating element group, and the vibrating element 21b can be used as the receiving vibrating element group.

According to the present invention, the material of the probe body is not particularly limited, and known materials can be appropriately used. The means for incorporating the plurality of vibrating elements into the probe body is 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 irradiation vibrating element group. When ultrasonic waves are applied to the inside of the object to be measured from the ultrasonic transducer, the propagation speed of the ultrasonic waves changes according to the internal structure and internal physical properties of the object to be measured, or the ultrasonic intensity decreases due to attenuation. According to the present invention, the ultrasonic waves transmitted through the inside of the object to be measured are received by two or more vibrating elements included in the receiving vibrating element group.

The received ultrasonic signal, i.e. the received data, should contain at least the following information: The information to be included is the position data of the irradiated vibrating element, the position data of the received vibrating element, the arrival time from irradiation to reception, the intensity data of the irradiated ultrasonic wave, and the data of the intensity of the received ultrasonic wave. ..

The irradiation of ultrasonic waves is sequentially performed from the first ultrasonic element to the Mth ultrasonic element, and each time, the ultrasonic wave is received by the vibrating element of the receiving vibrating element group. Therefore, the number of received data is, in principle, a number obtained by multiplying the number of vibrating elements of the irradiation vibrating element group, that is, M and the number of vibrating elements of the receiving vibrating element group.

From the received data thus obtained, it is possible to calculate the attenuation mode of the ultrasonic wave propagation velocity and the ultrasonic wave intensity at each position inside the measurement object. Obtaining the attenuation mode of the ultrasonic wave propagation velocity and the ultrasonic wave intensity from the above received 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 ultrasonic wave velocity and the attenuation rate of the ultrasonic intensity can be obtained with high accuracy.

In the aperture synthesis method, as described above, ultrasonic waves are sequentially transmitted from the first to Mth vibrating elements, and the transmitted ultrasonic waves have a shape discontinuity or a composition difference inside the object to be measured. The propagation velocity changes or the intensity decays based on the above. Therefore, it is possible to obtain a transmission source image in which shape discontinuities and composition differences that cause changes in the propagation velocity of ultrasonic waves and attenuation of ultrasonic wave intensity are viewed from various directions. As a result, the data as it is can be obtained from the position inside the measurement object where the propagation speed of ultrasonic waves changes and the ultrasonic wave intensity decays constantly, such as shape discontinuity, and conversely, it looks like a noise source of composition. Signals from highly random positions with respect to the behavior of ultrasonic waves tend to cancel each other out and become inconspicuous. This means that the S / N ratio of the signal is improved, which contributes to high accuracy of the obtained data.

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.

By knowing the propagation velocity of ultrasonic waves at each position inside the object to be measured and the intensity attenuation rate of ultrasonic waves, the composition and shape at that position can be estimated. When the object to be measured is a living body , It will contribute to grasping the condition of muscles and organs.

Further, according to the present invention, the ultrasonic measuring device includes a control device, and the control device is capable of irradiating ultrasonic waves as described above by each of the vibrating elements for irradiation and the vibrating elements for receiving. It is configured to operate so as to receive, and to calculate the propagation speed of ultrasonic waves and the intensity attenuation rate of ultrasonic waves at each position inside the measurement object as described above from the obtained received data. Has been done. Each calculated parameter 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.

As an example, consider the use of a probe having 256 vibrating elements for irradiation and 256 vibrating elements for receiving, for a total of 512 vibrating elements. The irradiation sequence is carried out in order from the first vibrating element of the irradiation vibrating element group. In one sequence, only one vibrating element is excited and all vibrating elements of the receiving vibrating element group are activated for reception. This process is repeated until the third vibrating element is excited and irradiated one by one in the order of the first, the second, and the like.

In order to calculate the propagation velocity (sound velocity) at each position of the object to be measured, the received data requires the position of the irradiated vibrating element, the position of the received vibrating element, and the arrival time from irradiation to reception. The speed of sound can be determined by considering both the propagation path and the arrival time. Regarding the estimation of the amount of attenuation, the peak energy of the vibrating element was recorded in all the irradiation data. Attenuation is defined as the reciprocal of the energy peak. FIG. 3 is an explanatory diagram of analysis of received data. Specifically, first, the absolute value of the waveform data (RF data) is calculated (FIGS. 3A and 3B), then energy is accumulated over time, and the peak energy of each vibrating element is recorded ( Fig. 3 (C), Fig. 3 (D)), normalize the cumulative energy to 0 to 1 (Fig. 3 (E)), set the energy threshold that determines the arrival time, and estimate the sound velocity in consideration of the propagation distance. To do.

Each parameter obtained from the transmission data of ultrasonic waves by the apparatus and method of the present invention can be used as the basis of 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, it is possible to contribute to an analysis different from the analysis based on the reflection of ultrasonic waves, which is often performed in the past, and a measurement / diagnosis with high accuracy and high accuracy. From such a viewpoint, the apparatus and method of the present invention are 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.

In addition, for example, by saving the received ultrasonic wave as waveform data and comparing it with other data such as CT and MRI, it is possible to consider an application such as finding a feature capable of determining the state or symptom of the measurement target from the waveform data. Be done. 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.

10/20 Ultrasonic probe 11.21 Vibrating element 12/22/23 Probe body 24 Frame 25 Groove

Claims (6)

(A) The irradiation vibrating element group having the first to first M (where M is an integer of 3 or more) and the receiving vibrating element group having a plurality of vibrating elements separately from the irradiation vibrating element group. A group of vibrating elements and one or more ultrasonic probes having the same are brought into contact with the object to be measured, and at this time,
A step of bringing the ultrasonic probe into contact with a measurement object so that a straight line connecting the vibration element of the irradiation vibration element group and the vibration element of the reception vibration element group passes through the inside of the measurement object.
(B) Ultrasonic waves are sequentially irradiated to the inside of the object to be measured from the first vibrating element to the Mth vibrating element, and the ultrasonic waves transmitted through the object to be measured are received for each irradiated vibrating element. By applying the step of receiving each of the plurality of vibrating elements of the receiving vibrating element group as data and (C) the aperture synthesis method based on the received data, the ultrasonic waves at each position inside the object to be measured It has a step of calculating the intensity attenuation and the propagation velocity of the ultrasonic waves,
Each of the received data includes 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, the intensity data of the irradiated ultrasonic waves, and the intensity data of the received ultrasonic waves. Including,
Ultrasonic measurement method for the object to be measured. The method according to claim 1, wherein M is an integer of 200 or more. The method according to claim 1 or 2, wherein the object to be measured is a living body. An irradiation vibrating element group having first to third M (where M is an integer of 3 or more) and a receiving vibrating element having a plurality of vibrating elements separately from the first vibrating element group. The control device includes one or more ultrasonic probes having a group, a control device, and an output device, and the control device includes the following (B) and (C).
(B) Ultrasonic waves are sequentially irradiated to the inside of the object to be measured from the first vibrating element to the Mth vibrating element, and the ultrasonic waves transmitted through the object to be measured are received for each irradiated vibrating element. By receiving the ultrasonic waves as data to a plurality of vibrating elements of the receiving vibrating element group, and (C) applying the aperture synthesis method based on the received data, the ultrasonic waves at each position inside the object to be measured Calculating the intensity decay and the propagation velocity of ultrasonic waves,
Is configured to run
The output device outputs at least one of the intensity attenuation of the ultrasonic wave generated in (C) and the propagation velocity of the ultrasonic wave.
Each of the received data includes 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, the intensity data of the irradiated ultrasonic waves, and the intensity data of the received ultrasonic waves. Including,
Ultrasonic measuring device for the object to be measured. The measuring device according to claim 4, wherein M is an integer of 200 or more. The measuring device according to claim 4 or 5, wherein the object to be measured is a living body.

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