WO2015034156A1

WO2015034156A1 - Methods and apparatuses for controlling ultrasound wave

Info

Publication number: WO2015034156A1
Application number: PCT/KR2014/003904
Authority: WO
Inventors: Sun-Kwon Kim; Joon-Ho Seo; Won-Chul Bang; Jong-Bum Son
Original assignee: Samsung Electronics Co., Ltd.
Priority date: 2013-09-03
Filing date: 2014-05-01
Publication date: 2015-03-12

Abstract

Disclosed is a method of controlling a parameter of an ultrasound wave. The method includes acquiring information about a region of interest (ROI) by using an echo signal obtained in response to an ultrasound wave which being irradiated onto a subject including the ROI, differently setting a first parameter of an ultrasound wave, which is to be irradiated onto the ROI, and a second parameter of an ultrasound wave, which is to be irradiated onto a region other than the ROI from among a plurality of regions of the subject, by using the acquired information about the ROI, and generating a control signal for a probe which irradiates the ultrasound wave onto the subject, based on the first and the second parameter.

Description

METHODS AND APPARATUSES FOR CONTROLLING ULTRASOUND WAVE

Methods and apparatuses consistent with exemplary embodiments relate to providing methods and apparatuses for controlling a parameter of an ultrasound wave irradiated onto a subject including a region of interest (ROI).

Probes transmit an ultrasound signal to a subject and generate an ultrasound image of the subject by using an echo signal that is reflected from the subject. Here, the ultrasound image of the subject includes a temperature image, indicating a temperature of a cross-sectional surface of the subject, or a brightness (B)-mode image indicating brightness of the cross-sectional surface of the subject.

Probes generate a high-resolution ultrasound image by using a one-dimensional (1D) phase array. Specifically, in order to generate the high-resolution ultrasound image, the probes transmit a number of ultrasound signals equal to the number of elements of the phase array, and receive echo signals respectively generated from the ultrasound signals. However, such a method generates an image at a low speed because the echo signals are received several times. For this reason, when a subject moves, an error between an actual subject and an ultrasound image occurs.

Accordingly, in the related art, research is being conducted into technology that restricts a size of an ROI of a subject to decrease the number of times a probe obtains echo signals, and thus enhance an image generation speed. However, in such a method, when a movement of a subject or an ultrasound probe is greater than a predetermined range of an ROI, it is difficult to generate an accurate image.

One or more exemplary embodiments provide methods and apparatuses for controlling a parameter of an ultrasound wave irradiated onto a subject including a region of interest (ROI).

According to an aspect of an exemplary embodiment, there is provided a method of controlling a parameter of an ultrasound wave including: acquiring information about a ROI by using an echo signal obtained in response to an ultrasound wave being irradiated onto a subject including the ROI; differently setting a first parameter of an ultrasound wave, which is to be irradiated onto the ROI, and a second parameter of an ultrasound wave, which is to be irradiated onto a region other than the ROI from among a plurality of regions of the subject, by using the acquired information about the ROI; and generating a control signal for a probe which irradiates the ultrasound wave onto the subject, based on the first parameter and the second parameter.

A high-resolution image including an ROI is generated at a high speed. Also, a high-resolution image including an ROI is generated even in an environment in which there is a movement of a subject (for example, a patient) or a probe. In addition, a parameter of an ultrasound wave irradiated onto an ROI of a subject and a parameter of an ultrasound wave irradiated onto a region other than the ROI are differently set, and thus, more information is acquired for an ROI within the same period of time compared to the methods of the related art.

The above and/or other aspects will become apparent and more readily appreciated by describing certain exemplary embodiments with reference to the accompanying drawings, in which:

FIG. 1 is a block diagram illustrating an example of an ultrasound processing apparatus, according to an exemplary embodiment;

FIG. 2 is a diagram for describing an example in which a parameter setter sets a first parameter and a second parameter, according to an exemplary embodiment;

FIGS. 3A and 3B include graphs showing a change in a signal quality or a change in a measurement time with respect to a width of an ultrasound focusing region, according to an exemplary embodiment;

FIG. 4 is a diagram for describing another example in which the parameter setter sets a first parameter and a second parameter, according to an exemplary embodiment;

FIGS. 5A and 5B include graphs showing a simulation result of a method of controlling a parameter of an ultrasound wave, according to an exemplary embodiment;

FIG. 6 is a block diagram illustrating another example of an ultrasound processing apparatus, according to an exemplary embodiment;

FIG. 7 is a diagram for describing an example in which the ultrasound processing apparatus operates, according to an exemplary embodiment;

FIG. 8 is a block diagram illustrating another example of an ultrasound processing apparatus, according to an exemplary embodiment;

FIGS. 9A and 9B are diagrams for describing another example in which the ultrasound processing apparatus operates, according to an exemplary embodiment; and

FIG. 10 is a flowchart illustrating an example of a method of controlling a parameter of an ultrasound wave, according to an exemplary embodiment.

According to aspect of another exemplary embodiment, there is provided is a non-transitory computer-readable storage medium storing a program for executing the method.

According to another aspect of another exemplary embodiment, there is provided an apparatus for controlling a parameter of an ultrasound wave including: an information acquirer configured to acquire information about an ROI by using an echo signal obtained in response to an ultrasound wave being irradiated onto a subject including the ROI; a parameter setter configured to differently set a first parameter of an ultrasound wave, which is to be irradiated onto the ROI, and a second parameter of an ultrasound wave, which is to be irradiated onto a region other than the ROI among a plurality of regions of the subject, by using the acquired information about the ROI; and a signal generator configured to generate a control signal for a probe which irradiates the ultrasound wave onto the subject, based on the first parameter and the second parameter.

Certain exemplary embodiments will now be described in greater detail with reference to the accompanying drawings.

In the following description, the same drawing reference numerals are used for the same elements, even in different drawings. The matters defined in the description, such as detailed construction and elements, are provided to assist in a comprehensive understanding of the exemplary embodiments. Thus, it is apparent that the exemplary embodiments can be carried out without those specifically defined matters. Also, well-known functions or constructions are not described in detail since they would obscure the exemplary embodiments with unnecessary detail.

FIG. 1 is a block diagram illustrating an example of an ultrasound processing apparatus 100, according to an exemplary embodiment.

Referring to FIG. 1, the ultrasound processing apparatus 100 includes an information acquirer 110, a parameter setter 120, and a signal generator 130. The ultrasound processing apparatus 100 of FIG. 1 is illustrated as including only certain elements associated with the present exemplary embodiment. Therefore, it will be understood by those of ordinary skill in the art that the ultrasound processing apparatus 100 may further include general-use elements in addition to the elements of FIG. 1.

Further, it will be understood by those of ordinary skill in the art that each of the information acquirer 110, parameter setter 120, and signal generator 130 of the ultrasound processing apparatus 100 of FIG. 1 may be provided as a separate apparatus.

The information acquirer 110, parameter setter 120, and signal generator 130 of the ultrasound processing apparatus 100 of FIG. 1 may correspond to one or more processors for performing their respective functions. Each of the processors may be implemented as an array of a plurality of logic gates, or may be implemented as a combination of a general-use microprocessor and a memory that stores a program executable by the microprocessor. Also, it will be understood by those of ordinary skill in the art that the elements may be implemented hardware modules, circuits, or as other types of hardware for performing their respective functions.

The information acquirer 110 acquires information about an ROI by using an echo signal generated from an ultrasound wave that is irradiated onto a subject including the ROI. Here, for example, the subject may include an organ such as a liver, an abdomen, a heart, a brain, etc., but is not limited thereto, and the ROI may include a lesion requiring treatment, but is not limited thereto.

At least one or more elements included in an ultrasound probe (not shown) irradiate an ultrasound wave onto a subject, and receive an echo signal reflected from the subject. The elements transmit the received echo signal to the information acquirer 110.

The information acquirer 110 acquires information about an ROI by using the echo signal transmitted from the ultrasound probe (not shown). Here, the information about the ROI may include a position and size of the ROI or kinds of materials constituting the ROI, but is not limited thereto. Also, the echo signal may denote a radio frequency (RF) signal obtained by converting the signal reflected from the subject, but is not limited thereto.

Furthermore, the information acquirer 110 may acquire information about the ROI from an image indicating the subject. Here, the image indicating the subject may be generated by using the echo signal (specifically, the RF signal) transmitted from the ultrasound probe (not shown). A method of generating the image indicating the subject by using the echo signal will be described below in greater detail with reference to FIG. 6.

The parameter setter 120 differently sets a parameter (hereinafter referred to as a first parameter) of an ultrasound wave to be irradiated onto the ROI, and a parameter (hereinafter referred to as a second parameter) of an ultrasound wave to be irradiated onto a region other than the ROI of a plurality of regions of the subject, by using the acquired information about the ROI. In other words, the parameter setter 120 receives the information about the ROI from the information acquirer 110, and sets the first and second parameters by using the received information.

Here, each of the first and second parameters denotes a width of an ultrasound focusing region or a sampling frequency of an ultrasound wave for the same region.

According to an exemplary embodiment, the parameter setter 120 may differently set the first parameter of the ultrasound wave to be irradiated onto the ROI, and the second parameter of the ultrasound wave to be irradiated onto the region other than the ROI. In other words, the ultrasound processing apparatus 100 may irradiate ultrasound waves onto a subject according to the first and second parameters, and generate an image indicating the subject by using echo signals.

Therefore, in an image indicating a subject, a resolution of a part corresponding to an ROI may differ from that of a part corresponding to a region other than the ROI. For example, in the image indicating the subject, the resolution of the part corresponding to the ROI may be higher than that of the part corresponding to the region other than the ROI.

According to an exemplary embodiment described below with reference to FIGS. 2 and 3, the parameter setter 120 may set first and second parameters such that a first region, on which an ultrasound wave to be irradiated onto an ROI focuses, is narrower than a second region on which an ultrasound wave to be irradiated onto a region other than the ROI focuses.

Hereinafter, a method in which the parameter setter 120 sets the first and second parameters will be described in greater detail with reference to FIGS. 2 and 3.

FIG. 2 is a diagram for describing an example in which a parameter setter sets a first parameter and a second parameter, according to an exemplary embodiment.

FIG. 2 illustrates an example in which elements 1-11 included in a probe 210 irradiate an ultrasound wave onto a subject from a time t to a time t+3. Here, the subject includes an ROI 220.

The probe 210 of FIG. 2 is illustrated as including a total of eleven elements 1-11, but is not limited thereto. In other words, the number of elements included in the probe 210 is not limited to eleven, and the elements are not limited to being arranged as a 1D array.

In FIG. 2, it is illustrated that a width of an ultrasound focusing region is determined depending on the number of elements irradiating an ultrasound wave, from among the elements included in the probe 210, but the present exemplary embodiment is not limited thereto. For example, although all the elements included in the probe 210 irradiate an ultrasound wave, a width of an ultrasound focusing region may be determined depending on a degree of delay of the irradiated ultrasound waves.

Moreover, in FIG. 2, ultrasound waves irradiated from the time t to the time t+3 denote respective ultrasound waves that are generated according to the first and second parameters set by the parameter setter 120.

At the time t, the probe 210 irradiates an ultrasound wave onto a region other than the ROI 220 of the subject, and receives an echo signal. Here, the region other than the ROI 220 is a region of which a high-resolution image is not required to be generated, and thus, the parameter setter 120 sets the second parameter such that a width of a region, on which the ultrasound wave irradiated from the probe 210 focuses, is large. Here, the large width of the ultrasound focusing region denotes that the ROI 220 is not included in an image which is generated by using an echo signal obtained from the irradiated ultrasound wave. For example, the parameter setter 120 sets the second parameter such that the ultrasound wave is irradiated onto a broad area of a region other than the ROI 220 at a same time, and an echo signal is received from the region.

From the time t+1 to the time t+2, the probe 210 irradiates an ultrasound wave onto the ROI 220, and receives an echo signal from the ROI 220. Here, since a high-resolution image of the ROI 220 should be generated, the parameter setter 120 sets the first parameter such that a width of a region, on which the ultrasound wave irradiated from the probe 210 focuses, is small. Here, the small width of the ultrasound focusing region denotes that an image, which is generated by using an echo signal obtained from the irradiated ultrasound wave, is an image indicating the ROI 220. For example, the parameter setter 120 sets the first parameter such that the ultrasound wave focuses on a narrow area of the ROI 220, and an echo signal is received from the ROI 220.

At the time t+3, the probe 210 irradiates an ultrasound wave onto a region other than the ROI 220 of the subject, and receives an echo signal. Here, the region other than the ROI 220 is a region of which a high-resolution image is not required to be generated, and thus, the parameter setter 120 sets the second parameter such that a width of a region, on which the ultrasound wave irradiated from the probe 210 focuses, is large.

Generally, as a width (i.e., a width of an ultrasound beam) of an ultrasound focusing region increases, a region for obtaining a high-quality ultrasound signal is reduced. In other words, as a width of an ultrasound focusing region increases, the quality of an image generated based on an echo signal is degraded. Also, as a width of an ultrasound focusing region increases, a measurement time that denotes a time taken until an ultrasound wave is irradiated and then an echo signal is received becomes shorter. Hereinafter, a change in signal quality or a change in measurement time with respect to a width of an ultrasound focusing region will be described with reference to FIGS. 3A and 3B.

FIGS. 3A and 3B include graphs showing a change in signal quality or a change in measurement time with respect to a width of an ultrasound focusing region, according to an exemplary embodiment.

Referring to FIG. 3A, a graph that shows a change in signal quality with respect to a width (i.e., a width of an ultrasound beam) of an ultrasound focusing region is illustrated. Here, the signal quality may be shown as a signal-to-noise ratio (SNR), and for example, a signal-to-noise ratio "SNR(x)" may be calculated using the following Equation (1):

MathFigure 1

where x is position coordinates in an ultrasound image, and denotes a position of a subject on which an ultrasound wave focuses. Also, Average_time(x) denotes an average value of ultrasound signals with respect to time, and STD_time(x) denotes a standard deviation of ultrasound signals with respect to time.

The graph of FIG. 3A shows a result that is calculated using Equation (1). In FIG. 3A it can be seen that as a width of an ultrasound focusing region increases, an SNR becomes lower. Therefore, as a width of a region, onto which an ultrasound wave generated according to the parameter set by the parameter setter 120 focuses, increases, a quality of an image generated based on an echo signal is degraded.

Referring to FIG. 3B, a graph that shows a change in a measurement time (i.e., acquisition time) with respect to a width (i.e., a width of an ultrasound beam) of an ultrasound focusing region is illustrated. The graph of FIG. 3B may be acquired from the following Equations (2) to (5):

MathFigure 2

where Beamwidth denotes a width of an ultrasound focusing region, N_element denotes the number of elements irradiating an ultrasound wave, from among the elements included in the probe 210, and W_element denotes a width of one element. Here, it is assumed that the elements included in the probe 210 are arranged as a 1D array type.

MathFigure 3

where time_acq denotes a measurement time (i.e., a total time taken until an ultrasound wave is irradiated onto a region for acquiring an image and then an echo signal is received.), N_acq denotes the number of times an ultrasound wave is irradiated for acquiring an image, and T₁ denotes a total time taken until an ultrasound wave is irradiated and then an echo signal is received per session. Here, N_acq and T₁ may be calculated from the following Equations (4) and (5):

MathFigure 4

where N_array denotes the total number of elements included in the probe 210, and N_element denotes the number of elements irradiating an ultrasound wave, from among the elements included in the probe 210.

MathFigure 5

where Depth denotes a measurement depth (i.e., a distance from an element (which irradiates an ultrasound wave) to a subject) of an ultrasound wave, and V_sound denotes a speed of the ultrasound wave.

The graph of FIG. 3B shows a result that is calculated using Equations (2) to (5). In FIG. 3B it can be seen that as a width of an ultrasound focusing region increases, a measurement time becomes shorter.

Referring again to FIG. 1, the parameter setter 120 sets the second parameter for an ultrasound wave to be irradiated onto a region other than an ROI of a subject such that a width of an ultrasound focusing region is large, and sets the first parameter for an ultrasound wave to be irradiated onto the ROI such that a width of an ultrasound focusing region is small. Therefore, the ultrasound processing apparatus 100 acquires high-quality information about an ROI within a short period of time.

According to an exemplary embodiment to be described below with reference to FIGS. 4 and 5, the parameter setter 120 sets the first and second parameters such that the first sampling frequency of an ultrasound wave is to be irradiated onto an ROI is higher than the second sampling frequency of an ultrasound wave to be irradiated onto a region other than the ROI.

The sampling frequency of an ultrasound wave to be irradiated onto a region refers to the number of times (e.g., per one frame) an ultrasound wave is to be irradiated onto the region.

Hereinafter, a method in which the parameter setter 120 sets the first and second parameters will be described in greater detail.

FIG. 4 is a diagram for describing another example in which the parameter setter sets a first parameter and a second parameter, according to an exemplary embodiment.

A probe 410 of FIG. 4 is illustrated as including a total of eleven elements 1-11, but is not limited thereto. In other words, the number of elements included in the probe 410 is not limited to eleven, and the elements are not limited to being arranged as a 1D array.

In FIG. 4, it is illustrated that a width of an ultrasound focusing region is determined depending on the number of elements irradiating an ultrasound wave, from among the elements included in the probe 410, but the present exemplary embodiment is not limited thereto. For example, although all the elements included in the probe 410 irradiate an ultrasound wave, a width of an ultrasound focusing region may be determined depending on a degree of delay of the irradiated ultrasound wave.

Moreover, in FIG. 4, ultrasound waves irradiated from the time t to the time t+7 denote respective ultrasound waves that are generated according to the first and second parameters set by the parameter setter 120.

At the time t, the probe 410 irradiates an ultrasound wave onto a region other than an ROI 420 of a subject, and receives an echo signal. Here, the region other than the ROI 420 is a region of which a high-resolution image is not required to be generated, and thus, the parameter setter 120 sets the second parameter such that the sampling frequency of an ultrasound wave irradiated from the probe 410 is low. For example, the parameter setter 120 may set the second parameter such that the sampling frequency for the region other than the ROI 420 becomes 1, but the present exemplary embodiment is not limited thereto.

Here, the low sampling frequency of an ultrasound wave denotes that the ROI 420 is not included in an image which is generated by using an echo signal obtained from the irradiated ultrasound wave. In other words, the parameter setter 120 sets the second parameter such that an ultrasound wave is irradiated onto the region other than the ROI 420 at the low sampling frequency, and an echo signal is received from the region.

At each of the times from time t+1 to the time t+6, the probe 410 irradiates an ultrasound wave onto the ROI 420, and receives an echo signal from the ROI 420. Here, since a high-resolution image of the ROI 420 should be generated, the parameter setter 120 sets the first parameter such that the sampling frequency of an ultrasound wave irradiated from the probe 410 is high. For example, the parameter setter 120 may set the first parameter such that the sampling frequency for the ROI 420 becomes 3, but the present exemplary embodiment is not limited thereto.

Here, the high sampling frequency of an ultrasound wave denotes that an image, which is generated by using an echo signal obtained from the irradiated ultrasound wave, indicates the ROI 420. In other words, the parameter setter 120 sets the first parameter such that an ultrasound wave is irradiated onto the ROI 420 at the high sampling frequency, and an echo signal is received from the ROI 420.

At the time t+7, the probe 410 irradiates an ultrasound wave onto a region other than the ROI 420 of the subject, and receives an echo signal. A method, in which the parameter setter 120 sets the second parameter of an ultrasound wave to be irradiated at the time t+7, is as described above in detail with reference to the time t.

Generally, as the sampling frequency becomes higher, a quality (i.e., a resolution) of an image generated based on an echo signal is enhanced. On the other hand, as the sampling frequency becomes higher, a time taken in generating an image becomes longer. In the related art, ultrasound waves are respectively irradiated onto all regions of a subject at the same sampling frequency, and echo signals are received from the respective regions. Due to this, much time is consumed in acquiring a high-quality image. However, the parameter setter 120 according to an exemplary embodiment differently sets the frequency numbers of sampling for an ROI and a region other than the ROI, and thus, the ultrasound processing apparatus 100 acquires high-quality information about the ROI within a short period of time.

Hereinafter, an operation of the parameter setter 120 will be described in detail with reference to FIGS. 5A and 5B.

FIGS. 5A and 5B include graphs showing a simulation result of a method of controlling a parameter of an ultrasound wave, according to an exemplary embodiment.

Referring to FIG. 5A, a relationship between the number (i.e., the sampling frequency) of measurements and a measurement time is shown. Specifically, a graph 510 is a graph that is obtained based on the related art method, and each of graphs 520 to 540 denotes a graph that is obtained according to the first and second parameters set by the parameter setter 120.

Referring to the graph 510, the related art method respectively irradiates ultrasound waves onto all regions of a subject at the same sampling frequency, and receives echo signals from the respective regions, and due to this, much time is expended in proportion to the number of measurements.

On the other hand, referring to the graphs 520 to 540, the probe 410 respectively irradiates ultrasound waves onto an ROI and a region other than the ROI at the different sampling frequencies, and receives echo signals, and thus, a total measurement time per the same number of measurements is shortened compared to the related art method. Here, each of graphs 520 to 540 denotes a graph that is obtained by differently setting sizes of ROIs.

Referring to FIG. 5B, a relationship between the number (i.e., the sampling frequency) of measurements and a measurement time is shown. Specifically, a graph 550 is a graph that is obtained based on the related art method, and each of graphs 560 to 580 denotes a graph that is obtained according to the first and second parameters set by the parameter setter 120.

Referring to the graph 550, the related art method respectively irradiates ultrasound waves onto all regions of a subject at the same sampling frequency, and receives echo signals from the respective regions. Due to this, a time taken until an ultrasound wave focuses on an ROI and then again focuses on the ROI is long.

On the other hand, referring to the graphs 560 to 580, the probe 410 respectively irradiates ultrasound waves onto an ROI and a region other than the ROI at the different frequency numbers of sampling, and receives echo signals. Specifically, in FIG. 5B, 1, 4, 7, and 10, indicating the number of measurements, denote orders of ultrasound waves focusing on the ROI. Therefore, a time taken until an ultrasound wave focuses on an ROI and then again focuses on the ROI is short.

Referring again to FIG. 1, the parameter setter 120 sets the second parameter such that an ultrasound wave to be irradiated onto a region other than an ROI of a subject has the low sampling frequency, and sets the first parameter such that an ultrasound wave to be irradiated onto the ROI of a subject has the high sampling frequency. Therefore, the ultrasound processing apparatus 100 acquires high-quality information about an ROI within a short period of time.

The signal generator 130 generates a control signal for a probe on the basis of the set parameters. Here, the control signal denotes a control signal for an ultrasound wave which is irradiated onto a subject by the probe.

In detail, the signal generator 130 receives information about the first and second parameters from the parameter setter 120. The signal generator 130 generates a transmission beam-forming signal on the basis of the first and second parameters. Here, the beam-forming signal denotes a signal, which is used to designate elements for irradiating an ultrasound wave, from among a plurality of elements included in the probe, or a signal in which an amplitude and phase of an ultrasound wave to be irradiated from each of the elements have been determined.

FIG. 6 is a block diagram illustrating another example of an ultrasound processing apparatus 100 according to an exemplary embodiment.

Referring to FIG. 6, the ultrasound processing apparatus 100 further includes an image generator 140 in addition to the information acquirer 110, the parameter setter 120, and the signal generator 130. The ultrasound processing apparatus 100 of FIG. 6 is illustrated as including only certain elements associated with the present exemplary embodiment. Therefore, it will be understood by those of ordinary skill in the art that the ultrasound processing apparatus 100 may further include general-use elements in addition to the elements of FIG. 1.

Further, it will be understood by those of ordinary skill in the art that each of the elements of the ultrasound processing apparatus 100 of FIG. 6 may be provided as a separate apparatus.

The elements of the ultrasound processing apparatus 100 of FIG. 6 may correspond to one or more processors for performing their respective functions. Each of the processors may be implemented as an array of a plurality of logic gates, or may be implemented as a combination of a general-use microprocessor and a memory that stores a program executable by the microprocessor. Also, it will be understood by those of ordinary skill in the art that the elements may be implemented as hardware modules, circuits, or other types of hardware for performing their respective functions.

Details of the information acquirer 110, the parameter setter 120, and signal generator 130 of FIG. 6 are as described above with reference to FIG. 1, and thus, their detailed description will not be provided below.

The image generator 140 generates an image indicating a subject by using an echo signal obtained from an irradiated ultrasound wave. Specifically, the image generator 140 generates an image indicating a subject by using an echo signal received from a probe.

For example, the image generator 140 may receive and beam-form an echo signal reflected from a subject to acquire N number of RF frames. Here, N may be a natural number equal to or greater than one, and may be determined according to a degree of space resolution or a degree of temperature resolution. To provide a description on the space resolution as an example, thousands of frames should be acquired per second for observing at a resolution of several mm. The image generator 140 generates an ultrasound image indicating the subject by using the N RF frames.

According to an exemplary embodiment, the information acquirer 110 may acquire information about an ROI from the image generated by the image generator 140. Specifically, the information acquirer 110 may acquire the information about the ROI by using an echo signal, and moreover acquire the information about the ROI from the RF frames or ultrasound image generated by the image generator 140.

The ultrasound processing apparatus 100 cannot completely acquire information about an ROI at an initial stage. In other words, in regard to the exemplary embodiments described above with reference to FIGS. 1 to 5B, it was assumed that the information acquirer 110 completely acquires information about an ROI. Hereinafter, the ultrasound processing apparatus 100 may not completely acquire the information about the ROI at an initial stage, and an example of generating a high-resolution image of an ROI in this regard will be described with reference to FIG. 7.

FIG. 7 is a diagram for describing an example in which the ultrasound processing apparatus operates, according to an exemplary embodiment.

A probe 710 of FIG. 7 is illustrated as including a total of eleven elements 1-11, but is not limited thereto. In other words, the number of elements included in the probe 710 is not limited to eleven, and the elements are not limited to being arranged as a 1D array.

At a time t, the probe 710 respectively irradiates ultrasound waves onto all regions of a subject including an ROI 720, and receives echo signals. The image generator 140 acquires N number of RF frames by using the echo signals, and generates an ultrasound image indicating the subject.

The information acquirer 110 determines whether information about the ROI 720 is acquirable by using the image which indicates the subject and is generated by using the echo signals obtained from the ultrasound waves irradiated onto the subject. In other words, the information acquirer 110 acquires the information about the ROI 720 by using the N RF frames or the ultrasound image indicating the subject. However, if information included in the ultrasound image indicating the subject or the N RF frames is unclear, the information acquirer 110 may not completely acquire the information about the ROI 720.

The parameter setter 120 sets a parameter of an ultrasound wave to be re-irradiated according to a result of the determining. Specifically, if the information acquirer 110 cannot completely acquire the information about the ROI 720, the parameter setter 120 sets a parameter such that a region, on which an ultrasound wave to be re-irradiated onto a region estimated as the ROI 720 focuses, has a narrow area.

The signal generator 130 generates a control signal for a probe on the basis of the parameter set by the parameter setter 120. Here, the control signal denotes a control signal for an ultrasound wave which is re-irradiated onto the region estimated as the ROI 720.

At a time t+1 and a time t+2, the probe 710 re-irradiates an ultrasound wave onto the subject, and receives an echo signal. The image generator 140 acquires N number of RF frames by using the echo signal, and generates an ultrasound image indicating the subject. In this case, the RF frames or the ultrasound image at the time t+2 have/has a higher resolution of a specific region (i.e., the ROI 720) than the RF frames or the ultrasound image at the time t.

At a time t+3, the probe 710 respectively re-irradiates ultrasound waves on all regions of the subject including the ROI 720, and receives echo signals. The image generator 140 acquires N number of RF frames by using the echo signals, and generates an ultrasound image indicating the subject. In other words, an operation performed at the time t is repeated, and then, operations performed at the time t+1 and the time t+2 are repeated.

Referring again to FIG. 6, the ultrasound processing apparatus 100 may repeatedly perform the operations which have been described above with reference to FIG. 7 at the time t to the time t+2, and thus, even when information about an ROI is not completely acquired by using echo signals obtained from ultrasound waves first irradiated onto all regions of a subject, the ultrasound processing apparatus 100 may finally generate a high-resolution image of the ROI.

FIG. 8 is a block diagram illustrating another example of an ultrasound processing apparatus according to an exemplary embodiment.

Referring to FIG. 8, the ultrasound processing apparatus 100 further includes a temperature information generator 150 in addition to the information acquirer 110, the parameter setter 120, the signal generator 130, and the image generator 140. The ultrasound processing apparatus 100 of FIG. 8 is illustrated as including only certain elements associated with the present exemplary embodiment. Therefore, it will be understood by those of ordinary skill in the art that the ultrasound processing apparatus 100 may further include general-use elements in addition to the elements of FIG. 8.

Further, it will be understood by those of ordinary skill in the art that each of the elements of the ultrasound processing apparatus 100 of FIG. 8 may be provided as a separate apparatus.

The elements of the ultrasound processing apparatus 100 of FIG. 8 may correspond to one or more processors for performing their respective functions. Each of the processors may be implemented as an array of a plurality of logic gates, or may be implemented as a combination of a general-use microprocessor and a memory that stores a program executable by the microprocessor. Also, it will be understood by those of ordinary skill in the art that the elements may be implemented as hardware modules, circuits, or other types of hardware for performing their respective functions.

Details of the information acquirer 110, the parameter setter 120, the signal generator 130, and the image generator 140 of FIG. 6 are as described above with reference to FIGS. 1 and 6, and thus, their detailed description will not be provided below.

The temperature information generator 150 generates information indicating a temperature change of a subject by using an echo signal obtained from an irradiated ultrasound wave. Specifically, the temperature information generator 150 generates the information indicating the temperature change of the subject by using the echo signal received from a probe.

For example, the temperature information generator 150 may compare a reference RF signal with an RF signal obtained by converting the echo signal to detect a delay portion of the echo signal, and calculate a change amount of the delay. The temperature information generator 150 may detect a temperature change value corresponding to the calculated change amount of the delay.

Moreover, the temperature information generator 150 may transfer the detected temperature change value to the image generator 140, which may generate a temperature map corresponding to the temperature change value.

It has been described above that the temperature information generator 150 detects the delay portion of the echo signal to generate temperature information of the subject, but the present exemplary embodiment is not limited thereto. For example, the temperature information generator 150 may detect an amplitude-changed portion of the echo signal to generate the temperature information of the subject.

When elements included in a probe (not shown) are not arranged as a 1D array type, the parameter setter 120 may set a parameter in a method different from that of the above-described exemplary embodiments. For example, when the elements included in the probe (not shown) are arranged as a convex type array, the parameter setter 120 may set a parameter in a method different from that of the exemplary embodiments described above with reference to FIGS. 2, 4, and 7.

Hereinafter, the elements included in the probe (not shown) are arranged as a convex type array, and an example in which the elements included in the ultrasound processing apparatus 100 including the parameter setter 120 operate will be described in detail.

FIGS. 9A and 9B are diagrams for describing another example in which the ultrasound processing apparatus operates, according to an exemplary embodiment.

In FIG. 9A, an example in which the elements (which are arranged as a 1D array type) included in the probe 910 respectively irradiate ultrasound waves is illustrated.

When the elements included in the probe 910 are arranged as a 1D array type, the ultrasound waves irradiated from the respective elements travel in the same direction. In this case, as described above with reference to FIGS. 2, 4, and 7, the parameter setter 120 may set a parameter that indicates a width of an ultrasound focusing region or the sampling frequency of an ultrasound wave.

In FIG. 9B, an example in which elements (which are arranged as a convex type array) included in a probe 920 according to an exemplary embodiment respectively irradiate ultrasound waves is illustrated.

When the elements included in the probe 920 are arranged as a convex type array, the ultrasound waves irradiated from the respective elements do not travel in the same direction. Ultrasound signals respectively transmitted from two or more elements overlap each other in a specific region 930 of a subject. Therefore, the parameter setter 120 sets a parameter such that an ROI is included in the region 930 where the ultrasound signals respectively transmitted from the two or more elements overlap each other.

When the ROI is included in the region 930 where the ultrasound signals respectively transmitted from the two or more elements overlap each other, the ROI has more ultrasound signals, passing through one point, than the other regions constituting the subject. Therefore, the image generator 140 may generate a high-quality image of the ROI by using an echo signal.

The temperature information generator 150 generates information indicating a temperature change of a subject by using an echo signal obtained from an irradiated ultrasound wave. In this case, when an ultrasound wave is irradiated and an echo signal is received by using the probe 920 of which the elements are arranged as a convex type array, the temperature information generator 150 may separate and acquire two pieces of information, respectively indicating a motion and temperature of the ROI, from the echo signal.

For example, as illustrated in FIG. 9B, when it is assumed that the probe 920 is configured with an A-part and a B-part, an echo signal received from the A-part may be expressed as the following Equations (6) and (7):

MathFigure 6

where E_A,axial denotes an echo shift, which is calculated from the echo signal received from the A-part, in an axial direction. E_{A,temperature} denotes an echo shift caused by a temperature change in the axial direction in the ROI, and E_{A,motion,axial} denotes an echo shift caused by a motion in the axial direction in the ROI. Here, the echo shift denotes a delay portion of the echo signal.

MathFigure 7

where E_A,lateral denotes an echo shift, which is calculated from the echo signal received from the A-part, in a lateral direction. E_{A,motion,lateral} denotes an echo shift caused by a temperature change in the lateral direction in the ROI. Here, the echo shift denotes the delay portion of the echo signal.

Moreover, an echo signal received from the B-part may be expressed as the following Equations (8) and (9):

MathFigure 8

where E_B,axial denotes an echo shift, which is calculated from the echo signal received from the B-part, in an axial direction. E_{B,temperature} denotes an echo shift caused by a temperature change in the axial direction in the ROI, and E_{B,motion,axial} denotes an echo shift caused by a motion in the axial direction in the ROI. Here, the echo shift denotes a delay portion of the echo signal.

MathFigure 9

where E_B,lateral denotes an echo shift, which is calculated from the echo signal received from the B-part, in a lateral direction. E_{B,motion,lateral} denotes an echo shift caused by a temperature change in the lateral direction in the ROI. Here, the echo shift denotes the delay portion of the echo signal.

E_A,axial may be expressed as the following Equation (10), and E_A,lateral may be expressed as the following Equation (11):

MathFigure 10

MathFigure 11

where θ denotes a degree by which a traveling direction of an ultrasound wave is inclined with respect to the axial direction.

The temperature information generator 150 may solve simultaneous equations of Equations (6) to (11) to calculate E_{A,temperature}, E_{B,temperature}, E_{A,motion,axial}, E_{A,motion,lateral}, E_{B,motion,axial}, and E_{B,motion,lateral}. Each of the calculated E_{A,motion,axial}, E_{A,motion,lateral}, E_{B,motion,axial}, and E_{B,motion,lateral} denotes information indicating a motion of the ROI. Therefore, the temperature information generator 150 may separate and acquire the information indicating the temperature of the ROI and the information indicating the motion of the ROI by using the echo signal received by the probe 920 of FIG. 9B.

The temperature information generator 150 generates information indicating a temperature change of the subject by using the acquired information "E_{A,temperature} and E_{B,temperature}". The image generator 140 may generate a temperature map corresponding to a temperature change value by using the information received from the temperature information generator 150.

Referring to FIG. 10, the method of controlling a parameter of an ultrasound wave includes a plurality of operations that are performed in time series by the ultrasound processing apparatus 100 of FIGS. 1, 6, or 8. Thus, although not described below, the above-described details of the ultrasound processing apparatus 100 of FIGS. 1, 6, or 8 may be applied to the method of controlling a parameter of an ultrasound wave in FIG. 10.

In operation 1010, the information acquirer 110 acquires information about an ROI by using an echo signal obtained from an ultrasound wave that is irradiated onto a subject including the ROI.

In operation 1020, the parameter setter 120 differently sets a parameter (i.e., the first parameter) of an ultrasound wave to be irradiated onto the ROI, and a parameter (i.e., the second parameter) of an ultrasound wave to be irradiated onto a region other than the ROI of a plurality of regions of the subject, by using the acquired information about the ROI.

In operation S1030, the signal generator 130 generates a control signal for a probe which irradiates an ultrasound wave onto the subject, on the basis of the set parameters.

As described above, according to the one or more of the above exemplary embodiments, a high-resolution image including an ROI is generated at a high speed. Also, a high-resolution image including an ROI is generated even in an environment in which there is a movement of a subject (for example, a patient) or a probe. In addition, a parameter of an ultrasound wave irradiated onto an ROI of a subject and a parameter of an ultrasound wave irradiated onto a region other than the ROI are differently set, and thus, more information is acquired for an ROI within the same period of time compared to the methods of the related art.

The above-described method may be written as computer programs and may be implemented in general-use computers that execute the programs using a computer-readable recording medium. Data structures used in the above-described method may be recorded in a computer-readable recording medium by using various methods. Examples of the computer-readable recording medium include magnetic storage media (e.g., ROM, RAM, USB, floppy disks, hard disks, etc.) and storage media such as optical recording media (e.g., CD-ROMs, or DVDs).

It should be understood that the foregoing exemplary embodiments should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each exemplary embodiment should typically be considered as available for other similar features or aspects in other exemplary embodiments. Also, the description of the exemplary embodiment is intended to be illustrative, and not to limit the scope of the inventive concept, as defined by the appended claims, and many alternatives, modifications, and variations will be apparent to those of ordinary skill in the art.

Claims

A method of controlling a parameter of an ultrasound wave, the method comprising:

acquiring information about a region of interest (ROI) by using an echo signal obtained in response to an ultrasound wave being irradiated onto a subject including the ROI;

differently setting a first parameter of an ultrasound wave, which is to be irradiated onto the ROI, and a second parameter of an ultrasound wave, which is to be irradiated onto a region other than the ROI among a plurality of regions of the subject, by using the acquired information about the ROI; and

generating a control signal for a probe which irradiates the ultrasound wave onto the subject, based on the first parameter and the second parameter.
The method of claim 1, wherein each of the first parameter and the second parameter is at least one from among a width of a region on which the ultrasound wave focuses, and a number of times the ultrasound wave is to be irradiated onto a same region.
The method of claim 2, wherein the differently setting comprises differently setting the first parameter and the second parameter such that a first region, onto which the ultrasound wave to be irradiated onto the ROI focuses, is narrower than a second region on which the ultrasound wave to be irradiated onto the region other than the ROI focuses.
The method of claim 2, wherein the differently setting comprises differently setting the first parameter and the second parameter such that a first number of times the ultrasound wave is to be irradiated onto the ROI is higher than a second number of times the ultrasound wave is to be irradiated onto the region other than the ROI.
The method of claim 1, further comprising generating an image indicating the subject by using the echo signal obtained in response to the ultrasound wave being irradiated onto the subject.
The method of claim 5, wherein in the generated image, a resolution of a part corresponding to the ROI differs from a resolution of a part corresponding to the region other than the ROI.
The method of claim 1, further comprising acquiring information about a temperature change of the subject by using the echo signal obtained in response to the ultrasound wave being irradiated onto the subject.
The method of claim 7, wherein the acquiring comprises separating and acquiring information which respectively indicates a motion and temperature change of the ROI, by using the echo signal obtained in response to the ultrasound wave being irradiated onto the subject.
The method of claim 1, wherein the acquiring comprises:

determining whether information about the ROI is acquirable, by using an image which indicates the subject and which is generated by using the echo signal obtained in response to the ultrasound wave being irradiated onto the subject;

setting the first parameter of the ultrasound wave to be irradiated onto the ROI, based on a result of the determining; and

irradiating the ultrasound wave, corresponding to the first parameter, onto the ROI, and acquiring the information about the ROI by using the image which indicates the subject and which is generated by using the echo signal obtained in response to the ultrasound wave being irradiated onto the subject.
A non-transitory computer-readable storage medium storing a program for executing the method of claim 1.
An apparatus for controlling a parameter of an ultrasound wave, the apparatus comprising:

an information acquirer configured to acquire information about a region of interest (ROI) by using an echo signal obtained in response to an ultrasound wave being irradiated onto a subject including the ROI;

a parameter setter configured to differently set a first parameter of an ultrasound wave, which is to be irradiated onto the ROI, and a second parameter of an ultrasound wave, which is to be irradiated onto a region other than the ROI of a plurality of regions of the subject, by using the acquired information about the ROI; and

a signal generator configured to generate a control signal for a probe which irradiates the ultrasound wave onto the subject, based on the first parameter and the second parameter.
The apparatus of claim 11, wherein each of the first parameter and the second parameter is one from among a width of a region on which the ultrasound wave focuses, and a number of times the ultrasound wave is to be irradiated onto a same region.
The apparatus of claim 12, wherein the parameter setter is further configured to differently set the parameters such that a first region, on which the ultrasound wave to be irradiated onto the ROI focuses, is narrower than a second region on which the ultrasound wave to be irradiated onto the region other than the ROI focuses.
The apparatus of claim 12, wherein the parameter setter is further configured to differently set the first parameter and the second parameter such that a first number of times the ultrasound wave is to be irradiated onto the ROI is higher than a second number of times the ultrasound wave is to be irradiated onto the region other than the ROI.
The apparatus of claim 11, further comprising an image generator configured to generate an image indicating the subject by using the echo signal obtained in response to the ultrasound wave being irradiated onto the subject.
The apparatus of claim 15, wherein in the generated image, a resolution of a part corresponding to the ROI differs from a resolution of a part corresponding to the region other than the ROI.
The apparatus of claim 11, further comprising a temperature information generator configured to acquire information about a temperature change of the subject by using the echo signal obtained in response to the ultrasound wave being irradiated onto the subject.
The apparatus of claim 17, wherein the temperature information generator is further configured to separate and acquire information which respectively indicates a motion and temperature change of the ROI, by using the echo signal obtained in response to the ultrasound wave being irradiated onto the subject.
The apparatus of claim 11, wherein,

the information acquirer is further configured to determine whether information about the ROI is acquirable, by using an image which indicates the subject and which is generated by using the echo signal obtained in response to the ultrasound wave being irradiated onto the subject, and acquire the information about the ROI by using an image which indicates the subject and is which generated by using the echo signal obtained in response to the ultrasound wave being re-irradiated onto the ROI, based on a result of the determining,

the parameter setter is further configured to set a parameter of the re-irradiated ultrasound wave based the result of the determining, and

the signal generator is further configured to generate a control signal for the probe which re-irradiates the ultrasound wave, based on the set parameter.