Patent Description:
Ultrasound imaging apparatuses transmit, to an object, ultrasound signals generated by transducers of a probe and receive information about signals reflected from the object to obtain at least one image of an internal part (e.g., soft tissue or blood flow) of the object.

In a spectral Doppler mode, quadrature detection is performed on an ultrasound echo signal received via a probe to extract a Doppler signal having a frequency component that undergoes a Doppler shift due to motion of an object such as blood flow or a heart wall. By obtaining a Doppler image from a Doppler signal, a user may identify blood flow information such as a location, a direction, and a velocity of blood flow. In pulse wave (PW) Doppler of the related art, a Doppler signal is generated by obtaining a single receive beam for an ultrasound transmit beam applied to an object via a probe. When the ultrasound transmit beam is not aligned with a direction of blood flow but forms a certain angle with respect thereto, the user needs to manually correct an angle of a sample volume to be aligned with the direction of blood flow in order to accurately measure a velocity of blood flow.

In general, a correction operation for aligning the angle of sample volume with the direction of blood flow is manually performed through a user's naked eye, resulting in low correction accuracy. Furthermore, each time additional imaging is performed or each time the direction of blood flow is changed due to a patient's breathing, the user has to repeatedly perform correction operations to align the angle of the sample volume with the direction of blood flow. Frequent corrections to the angle of the sample volume causes user inconvenience and degrades accuracy of blood velocity measurement. In particular, when there is an error in correcting an angle between directions of the sample volume and blood flow, misdiagnosis may occur.

<CIT> and <CIT> describe correcting the longitudinal angle of the sample volume based on the moving direction of the blood flow, but do not disclose obtaining the trend line, and correcting the angle based on a trend line to acquire the blood flow velocity based on the more accurate moving direction of the blood flow. <CIT> describes angle correction based on the direction of blood flow, but does not describe obtaining a more accurate blood flow rate by acquiring a trend line and correcting the speed (direction) of blood flow using the angle formed by a trend line and the scan line.

In accordance with an aspect of the disclosure, a method according to claim <NUM> is provided.

In accordance with another aspect of the disclosure, an ultrasound imaging apparatus according to claim <NUM>.

In accordance with another aspect of the disclosure, a computer-readable recording medium according to claim <NUM> is provided.

Although the terms used in the disclosure have been described in general terms that are currently used in consideration of the functions referred to in the disclosure, the terms are intended to encompass various other terms depending on the intent of those skilled in the art, precedents, or the emergence of new technology.

Also, some of the terms used herein may be arbitrarily chosen by the applicant. In this case, these terms are defined in detail below.

Accordingly, the terms used in the disclosure are not defined based on the meaning of the term, not on the name of a simple term, but on the contents throughout the disclosure.

The terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosure belongs.

Throughout the entirety of the specification of the disclosure, when it is assumed that a certain part includes a certain element, the term 'including' means that a corresponding element may further include other elements unless a specific meaning opposed to the corresponding element is written.

The term used in the embodiments of the disclosure such as "unit" or "module" indicates a unit for processing at least one function or operation, and may be implemented in hardware, software, or in a combination of hardware and software.

According to the situation, the expression "configured to" used herein may be used as, for example, the expression "suitable for", "having the capacity to", "designed to", "adapted to", "made to", or "capable of".

The term "configured to" must not mean only "specifically designed to" in hardware.

Instead, the expression "a device configured to" may mean that the device is "capable of" operating together with another device or other elements.

For example, a "processor configured to (or set to) perform A, B, and C" may mean a dedicated processor (e.g., an embedded processor) for performing a corresponding operation or a generic-purpose processor (e.g., a central processing unit (CPU) or an application processor) which performs corresponding operations by executing one or more software programs which are stored in a memory device.

In the present specification, an "object" may be a human, an animal, or a part of a human or animal. For example, the object may be an organ (e.g., the liver, the heart, the womb, the brain, a breast, or the abdomen), a blood vessel, or a combination thereof. Furthermore, the "object" may be a phantom. The phantom means a material having a density, an effective atomic number, and a volume that are approximately the same as those of an organism. For example, the phantom may be a spherical phantom having properties similar to the human body.

Furthermore, in the present specification, a "user" may be, but is not limited to, a medical expert, such as a medical doctor, a nurse, a medical laboratory technologist, and a technician who repairs a medical apparatus.

<FIG> is a block diagram of a configuration of an ultrasound imaging apparatus <NUM> according to an embodiment of the disclosure. The ultrasound imaging apparatus <NUM> of <FIG> is an apparatus for receiving ultrasound echo signals from an ultrasound probe <NUM> and generating an ultrasound image of an object, i.e., an inner part of a patient's body, by performing image processing on the received ultrasound signals. The ultrasound imaging apparatus <NUM> may be implemented as a cart-type apparatus, but is not limited thereto. For example, the ultrasound imaging apparatus <NUM> may be implemented as a portable-type apparatus including at least one of a picture archiving and communication system (PACS) viewer, a smart phone, a laptop computer, a tablet personal computer (PC), and a personal digital assistant (PDA).

Referring to <FIG>, the ultrasound imaging apparatus <NUM> may include the ultrasound probe <NUM>, an ultrasound transceiver <NUM>, a user input interface <NUM>, a processor <NUM>, a memory <NUM>, a storage <NUM>, and a display <NUM>. The components shown in <FIG> are only according to an embodiment of the disclosure, and components included in the ultrasound imaging apparatus <NUM> are not limited to those shown in <FIG>. The ultrasound imaging apparatus <NUM> may not include some of the components shown in <FIG> and may further include components not shown in <FIG>.

The ultrasound probe <NUM> may include a plurality of transducer elements that transmit ultrasound signals to an object, i.e., a patient's body, and receive ultrasound echo signals reflected from the patient's body. The ultrasound probe <NUM> may be connected to the ultrasound imaging apparatus <NUM> by wire or wirelessly. In an embodiment, the ultrasound probe <NUM> may be a separate probe that operates independently of the ultrasound imaging apparatus <NUM>. Furthermore, the ultrasound imaging apparatus <NUM> may include one or a plurality of ultrasound probes <NUM> according to its implemented configuration.

The transducer elements may transmit ultrasound signals to an object in response to transmit signals applied by a transmitter <NUM>. The transducer elements may receive ultrasound echo signals reflected from the object to produce receive signals. The processor <NUM> may control the transmitter <NUM> to produce transmit signals to be applied respectively to the transducer elements considering locations of the transducer elements in the ultrasound probe <NUM> and a focal point thereof. According to an embodiment, the transmitter <NUM> may produce, according to control by the processor <NUM>, a transmit signal for controlling the ultrasound probe <NUM> to transmit an ultrasound beam once. The processor <NUM> may control the receiver <NUM> to generate ultrasound data by performing analog-to-digital conversion (ADC) on receive signals provided by the ultrasound probe <NUM> and summing the digital receive signals based on the locations and focal point of the transducer elements.

The ultrasound probe <NUM> may receive a plurality of ultrasound echo signals along a plurality of scan lines by using a multiline receiving technique. In an embodiment, the ultrasound probe <NUM> may transmit an ultrasound beam to a region of interest (ROI) in an object along a single scan line according to control by the transmitter <NUM>, and a plurality of transducer elements of the ultrasound probe <NUM> may receive ultrasound echo signals for the ROI along a plurality of scan lines. When an imaging mode of the ultrasound imaging apparatus <NUM> is a spectral Doppler mode, the ultrasound probe <NUM> may receive Doppler data at a plurality of points in the ROI along a plurality of scan lines. In this case, the Doppler data may include spectral Doppler pulse wave information.

In an embodiment, the ultrasound probe <NUM> may obtain a plurality of pieces of Doppler data by repeatedly receiving ultrasound echo signals reflected from the object a plurality of times at pulse repetition frequency (PRF) intervals.

In an embodiment, the ROI may include a sample volume and may be a region wider than the sample volume. A sample volume refers to a region set to a specific depth value on any one of a plurality of scan lines. In an embodiment, a sample volume may be set based on a user input.

The user input interface <NUM> may receive a user input for controlling the ultrasound imaging apparatus <NUM>. For example, the user input interface <NUM> may receive user inputs via a button, a keypad, a mouse, a trackball, a jog switch, a knob, etc., a touch input for touching a touch pad or touch screen, a drag input, a swipe input, a voice input, a motion input, an input of biometric information (e.g., iris recognition, fingerprint recognition, etc.), etc. In an embodiment, to enter a spectral Doppler mode, the user input interface <NUM> may receive a user input such as pressing a specific button or touching a graphical user interface (GUI) displayed on the display <NUM>. In an embodiment, the user input interface <NUM> may receive a user input for setting an ROI in a spectral Doppler image or an ultrasound B- mode image.

The processor <NUM> may control all operations of the ultrasound imaging apparatus <NUM> and flow of signals among components within the ultrasound imaging apparatus <NUM>. The processor <NUM> may execute one or more instructions of a program stored in the memory <NUM>. The processor <NUM> may be composed of hardware components for performing arithmetic, logic and input/output operations, and signal processing. For example, the processor <NUM> may be configured with at least one of a central processing unit (CPU), a microprocessor, a graphics processing unit (GPU), application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), and field programmable gate arrays (FPGAs), but is not limited thereto.

A program including instructions for controlling the ultrasound imaging apparatus <NUM> may be stored in the memory <NUM>. The memory <NUM> may store one or more instructions and program code that may be read by the processor <NUM>. In the following embodiments, the processor <NUM> may be implemented by executing code or instructions of a program stored in the memory <NUM>.

For example, the memory <NUM> may include at least one type of storage medium from among random access memory (RAM), static RAM (SRAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), PROM, a flash memory-type memory, a hard disk-type memory, a multimedia card micro-type memory, a card-type memory (e.g., an SD card or an XD memory), a magnetic memory, a magnetic disc, and an optical disc.

The processor <NUM> may obtain Doppler data for each of a plurality of scan lines by using a multiline receiving technique, obtain information about a location and a direction of blood flow by analyzing power data of blood flow (hereinafter, referred to as blood flow power data) in an ROI based on the Doppler data, and correct an angle of a sample volume based on the obtained information about the location and direction of blood flow.

According to an embodiment, the storage <NUM> may store spectral Doppler pulse waves for a plurality of points in an ROI set to have a predetermined size around a position of a sample volume, wherein the spectral Doppler pulse waves are obtained by performing multiline receiving via the ultrasound probe <NUM>. Spectral Doppler pulse wave information may be classified for each of a plurality of scan lines and stored in the storage <NUM>. The processor <NUM> may obtain data regarding spectral Doppler pulse waves (hereinafter, referred to as spectral Doppler pulse wave data) for each of the scan lines stored in the storage <NUM>. In an embodiment, the processor <NUM> may obtain spectral Doppler pulse wave data for each scan line from the ultrasound probe <NUM> and not from the storage <NUM>.

The processor <NUM> may obtain blood flow power data from spectral Doppler pulse waves obtained at a plurality of points in an ROI for each of a plurality of scan lines. The processor <NUM> may normalize power data values of blood flow based on spectral Doppler pulse wave data obtained at PRF intervals. In an embodiment, the processor <NUM> may accumulate, in a time axis direction, N pieces of power data for spectral Doppler pulse waves obtained during a predetermined time period at PRF intervals and calculate an average value of the accumulated power data for each scan line. The processor <NUM> may calculate an average value of power data for each of a plurality of points included in each of the scan lines. A detailed method by which the processor <NUM> calculates an average value of power data for each of a plurality of points will be described in detail with reference to <FIG> and <FIG>.

The processor <NUM> may extract power data having a value greater than or equal to a predetermined threshold from among pieces of blood flow power data. According to an embodiment, the processor <NUM> may extract, for each of a plurality of scan lines, a point having an average power data value greater than or equal to a predetermined threshold from among average values of power data calculated at each of a plurality of points.

The processor <NUM> may identify points having values of the extracted power data from among a plurality of points in an ROI and obtain a trend line indicating a location and a direction of blood flow. In an embodiment, the processor <NUM> may extract power data having a maximum value from among pieces of blood flow power data obtained at a plurality of points for each of a plurality of scan lines and obtain a trend line by connecting points having values of the extracted power data to one another.

The processor <NUM> may calculate an angle between the obtained trend line and a scan line along which an ultrasound beam is transmitted, and correct an angle of a sample volume by using the calculated angle. According to an embodiment, the processor <NUM> may calculate an angle θ between a trend line and a scan line on which a sample volume is located from among a plurality of scan lines, and correct an angle by multiplying a velocity of blood flow passing through the sample volume by <NUM>/cos θ. A detailed method by which the processor <NUM> obtains a trend line and corrects an angle of a sample volume by using an angle between a trend line and a scan line will be described in detail with reference to <FIG> and <FIG>.

The processor <NUM> may update the trend line at predetermined time intervals. In an embodiment, the processor <NUM> may classify a plurality of pieces of Doppler data obtained at PRF intervals into a plurality of groups by grouping only at least one piece of Doppler data obtained during a predetermined time period from among the pieces of Doppler data, calculate an average value of power data from the at least one piece of Doppler data included in each of the groups, obtain a trend line by using the calculated average value, and update the obtained trend line based on passage of time. A detailed method by which the processor <NUM> updates a trend line based on passage of time will be described in detail below with reference to <FIG>, <FIG>, and <FIG>.

The processor <NUM> may display a trend line on the display <NUM>. According to an embodiment, the processor <NUM> may display a B-mode ultrasound image of the object on the display <NUM> and a trend line such that a graphic representing the trend line as a line or image is overlaid on the B-mode ultrasound image. In an embodiment, the processor <NUM> may update the trend line displayed on the display <NUM> at predetermined time intervals.

Spectral doppler pulse wave information may be classified for each scan line and stored in the storage <NUM>. The storage <NUM> may include at least one type of storage medium from among a flash memory-type memory, a hard disk-type memory, a multimedia card micro-type memory, a card-type memory (e.g., an SD card or an XD memory), a magnetic memory, a magnetic disc, and an optical disc. In an embodiment, the storage <NUM> may be implemented in the form of an external database rather than an internal component of the ultrasound imaging apparatus <NUM>.

For example, the display <NUM> may be configured as a physical display including at least one of a cathode-ray tube (CRT) display, a liquid crystal display (LCD), a plasma display panel (PDP), an organic light-emitting diode (OLED) display, a field emission display (FED), a light-emitting diode (LED) display, a vacuum fluorescent display (VFD), a digital light processing (DLP) display, a flat panel display (FPD), a three-dimensional (3D) display, and a transparent display, but is not limited thereto. In an embodiment, the display <NUM> may be configured as a touch screen including a touch interface. When the display <NUM> is configured as a touch screen, the display <NUM> may be a component integrated with the user input interface <NUM> formed as a touch panel.

<FIG> is a flowchart of an operation method of the ultrasound imaging apparatus <NUM>, according to an embodiment of the disclosure.

The ultrasound imaging apparatus <NUM> transmits an ultrasound beam to an ROI including a sample volume and obtains Doppler data with respect to the ROI based on a plurality of scan lines by using a multiline receiving technique (operation S210). In an embodiment, the ROI may include a sample volume, and may be a region wider than the sample volume. In an embodiment, the ROI may be set based on a user input. According to an embodiment, the ultrasound imaging apparatus <NUM> may transmit an ultrasound beam to an ROI via an ultrasound probe and receive ultrasound echo signals for a plurality of points in the ROI along the scan lines. When an imaging mode is set to a spectral Doppler mode, the ultrasound imaging apparatus <NUM> may obtain spectral Doppler pulse wave data at a plurality of points in an ROI along a plurality of scan lines by using a multiline receiving technique. According to an embodiment, the ultrasound imaging apparatus <NUM> may obtain a plurality of pieces of spectral Doppler pulse wave data over time by repeatedly receiving ultrasound echo signals a plurality of times at PRF intervals.

The ultrasound imaging apparatus <NUM> obtains information about a location and a direction of blood flow by analyzing blood flow power data with respect to the ROI based on Doppler data obtained for each of the scan lines (operation S220). According to an embodiment, the ultrasound imaging apparatus <NUM> may obtain spectral Doppler pulse wave data at a plurality of points in the ROI for each of the scan lines, and obtain blood flow power data from the spectral Doppler pulse wave data. The ultrasound imaging apparatus <NUM> may normalize power data values of blood flow based on spectral Doppler pulse wave data obtained at PRF intervals. In an embodiment, the ultrasound imaging apparatus <NUM> may accumulate, in a time axis direction, N pieces of power data for spectral Doppler pulse waves obtained during a predetermined time period at PRF intervals and calculate an average value of the accumulated power data for each of the scan lines. The ultrasound imaging apparatus <NUM> may calculate an average value of power data for each of a plurality of points included in each of the scan lines.

The ultrasound imaging apparatus <NUM> may extract power data having a value greater than or equal to a predetermined threshold from among blood flow power data. According to an embodiment, the ultrasound imaging apparatus <NUM> may extract a point having an average power data value greater than or equal to a predetermined threshold from among average power data values calculated for each of a plurality of points in each of the scan lines. The ultrasound imaging apparatus <NUM> may identify points having values of extracted power data from among a plurality of points in an ROI and obtain a trend line indicating a location and a direction of blood flow by connecting the identified points to one another. According to another embodiment, the ultrasound imaging apparatus <NUM> may extract power data having a maximum value from among pieces of blood flow power data respectively obtained at a plurality of points for each of the scan lines and obtain a trend line by connecting points having values of the extracted power data to one another.

The ultrasound imaging apparatus corrects an angle of the sample volume based on the information about the location and direction of the blood flow (operation S230). In an embodiment, the ultrasound imaging apparatus <NUM> may calculate an angle between a trend line indicating a location and a direction of blood flow and a scan line along which an ultrasound beam is transmitted, and correct an angle of a sample volume by using the calculated angle. According to an embodiment, the ultrasound imaging apparatus <NUM> may calculate an angle θ between a trend line and a scan line on which a sample volume is located from among a plurality of scan lines, and correct an angle by multiplying a velocity of the sample volume by <NUM>/cos θ.

According to the related art, to accurately measure a blood flow velocity inside a sample volume in the spectral Doppler mode, the user needs to perform a task of aligning an angle of the sample volume with a direction of the blood flow. To correct the angle of the sample volume, the user has to manually correct the angle of the sample volume with the naked eye. When the location of blood flow changes or the direction of the blood flow changes due to a patient's motion or breathing, the user has to repeatedly perform an operation of correcting the angle of the sample volume. In this case, the user is inconvenienced in having to manipulate the angle of the sample volume each time the location or direction of blood flow changes, and a blood flow velocity cannot be accurately measured by correcting the angle of the sample volume with the naked eye.

According to the embodiments illustrated in <FIG> and <FIG>, the ultrasound imaging apparatus <NUM> of the disclosure may obtain spectral Doppler pulse wave data for a plurality of points in an ROI including a sample volume by using a multiline receiving technique, obtain a trend line indicating a location and a direction of blood flow by using the spectral Doppler pulse wave data obtained at the points, and automatically correct an angle of the sample volume based on an angle formed between the trend line and a scan line where the sample volume is located. Accordingly, the ultrasound imaging apparatus <NUM> of the disclosure may provide more user convenience by omitting an operation of correcting an angle of a sample volume via a user input. Furthermore, the ultrasound imaging apparatus <NUM> of the disclosure may correct the angle of the sample volume by using a trend line indicating a location and a direction of blood flow, thereby increasing the accuracy of measuring a blood flow velocity.

In particular, the ultrasound imaging apparatus <NUM> of the disclosure uses spectral Doppler pulse wave data obtained by using the multiline receiving technique in the spectral Doppler mode to correct the angle of the sample volume, thereby eliminating the need to additionally generate a B-mode ultrasound image or color (C)-mode ultrasound image. Thus, a processing time required to generate a B- or C-mode ultrasound image may be reduced, thereby increasing a processing speed and improving a frame rate.

<FIG> is a diagram for describing an embodiment in which the ultrasound imaging apparatus <NUM> of the disclosure obtains Doppler data by using a multiline receiving technique.

Referring to <FIG>, the ultrasound imaging apparatus <NUM> may obtain a plurality of pieces of Doppler data, i.e., first through n-th pieces of Doppler data <NUM>-<NUM> through <NUM>-n, over time by repeatedly receiving ultrasound echo signals a plurality of times at PRF intervals. In an embodiment, the processor (<NUM> of <FIG>) of the ultrasound imaging apparatus <NUM> may obtain pieces of Doppler data composed of Doppler-shifted frequency components by performing quadrature detection of ultrasound echo signals, identify Doppler data corresponding to a sample volume SV, transform the identified Doppler data into frequency components, e. , by performing a fast Fourier transform (FFT) thereon, and obtain spectral Doppler pulse wave data by calculating power of the frequency components.

The ultrasound imaging apparatus <NUM> may transmit an ultrasound beam <NUM> to an ROI via the ultrasound probe (<NUM> of <FIG>), and obtain pieces of spectral Doppler pulse wave data at a plurality of points <NUM>-<NUM> through <NUM>-n in the ROI along a plurality of scan lines, i.e., first through seventh scan lines <NUM> through <NUM>, by using a multiline receiving technique. <FIG> shows seven (<NUM>) scan lines, i.e., the first through seventh scan lines <NUM> through <NUM>, for convenience of description, and the number of scan lines (the first through seventh scan lines <NUM> through <NUM>) is not limited to <NUM>.

The ROI may be a region including the sample volume SV. The sample volume SV may be a region set to a specific depth on the fourth scan line <NUM> among the first through seventh scan lines <NUM> through <NUM>. In an embodiment, the sample volume SV may be set based on a user input.

The ultrasound imaging apparatus <NUM> may obtain blood flow power data from spectral Doppler pulse wave data obtained at each of the points <NUM>-<NUM> through <NUM>-n, accumulate over time blood flow power data from each of the first through n-th pieces of Doppler data <NUM>-<NUM> through <NUM>-n obtained at PRF intervals, and store the accumulated blood flow power data in the storage (<NUM> of <FIG>). The points <NUM>-<NUM> through <NUM>-n refer to points having different depths along the first through seventh scan lines <NUM> through <NUM>. According to an embodiment, the processor <NUM> of the ultrasound imaging apparatus <NUM> may calculate a total power data value by adding power data values of blood flow, corresponding to spectral Doppler data obtained at a plurality of points having different depths for each of the first through seventh scan lines <NUM> through <NUM> in the first piece of Doppler data <NUM>-<NUM>, to power data values of blood flow, corresponding to spectral Doppler data obtained at the points <NUM>-<NUM> through <NUM>-n for each of the first through seventh scan lines <NUM> through <NUM> in the second piece of Doppler data <NUM>-<NUM>. Similarly, the processor <NUM> may accumulatively add power data values of blood flow, corresponding to spectral Doppler data obtained at the points <NUM>-<NUM> through <NUM>-n for each of the first through seventh scan lines <NUM> through <NUM> in the third piece of Doppler data <NUM>-<NUM>, to a total power data value calculated for each of the points <NUM>-<NUM> through <NUM>-n.

The ultrasound imaging apparatus <NUM> may normalize power data values accumulated for each of the points <NUM>-<NUM> through <NUM>-n. In an embodiment, the processor <NUM> may calculate an average value of power data for each of the points <NUM>-<NUM> through <NUM>-n by performing an operation of dividing a sum of power data accumulated for each of the points <NUM>-<NUM> through <NUM>-n along each of the first through seventh scan lines <NUM> through <NUM> by the number of pieces of Doppler data (the first through n-th pieces of data <NUM>-<NUM> through <NUM>-n) each obtained during a predetermined time period. In an embodiment, the processor <NUM> may calculate an average value of power data for each of the points <NUM>-<NUM> through <NUM>-n in the ROI.

<FIG> is flowchart of a method performed by the ultrasound imaging apparatus <NUM>, of obtaining Doppler data by using a multiline receiving technique, according to an embodiment of the disclosure.

The ultrasound imaging apparatus <NUM> obtains a plurality of pieces of Doppler data by repeatedly receiving ultrasound echo signals reflected from an object a plurality of times at PRF intervals (operation S410). According to an embodiment, the ultrasound imaging apparatus <NUM> may obtain a plurality of pieces of Doppler data for a plurality of points in an ROI based on a plurality of scan lines by using a multiline receiving technique.

The ultrasound imaging apparatus <NUM> obtains blood flow power data from the pieces of Doppler data (operation S420). According to an embodiment, the ultrasound imaging apparatus <NUM> may perform an FFT to transform the pieces of Doppler data obtained at the points in the ROI into frequency signal components, calculate powers of the frequency signal components, and obtain spectral Doppler pulse wave data by arranging the powers of the frequency signal components along a frequency axis. In an embodiment, the ultrasound imaging apparatus <NUM> may obtain blood flow power data from spectral Doppler pulse wave data.

The ultrasound imaging apparatus <NUM> accumulates and stores the obtained blood flow power data over time (operation S430). In an embodiment, the ultrasound imaging apparatus <NUM> may accumulatively add , power data values obtained at each of a plurality of points in an ROI and store the sum of the power data values calculated for each of the points in the storage <NUM> According to an embodiment, a plurality of points refer to points having different depths along a plurality of scan lines. In an embodiment, the ultrasound imaging apparatus <NUM> may calculate a sum of power data at each of the points by summing power data values obtained at each of the points having different depths for each of the plurality of scan lines.

The ultrasound imaging apparatus <NUM> calculates an average value of stored plurality of pieces of power data at each of a plurality of points in an ROI (operation S440). According to an embodiment, the ultrasound imaging apparatus <NUM> may calculate an average power data value for each of the points by performing an operation of dividing a sum of power data values accumulated for each of the points in each of a plurality of scan lines by the number of pieces of Doppler data each obtained during a predetermined time period. In an embodiment, the ultrasound imaging apparatus <NUM> may calculate an average value of power data for each of the points in the ROI.

<FIG> is a diagram for describing an embodiment in which the ultrasound imaging apparatus <NUM> of the disclosure corrects an angle of a sample volume by using information about a location and a direction of blood flow.

Referring to <FIG>, the ultrasound imaging apparatus <NUM> may obtain a trend line <NUM> indicating a location and a direction of blood flow based on values of blood flow power data obtained at a plurality of points <NUM> through <NUM> for each of a plurality of scan lines, i.e., first through seventh scan lines <NUM> through <NUM>. <FIG> shows seven (<NUM>) scan lines, i.e., the first through seventh scan lines <NUM> through <NUM>, for convenience of description, and the number of scan lines (the first through seventh scan lines <NUM> through <NUM>) is not limited to <NUM>. Furthermore, although <FIG> shows that each of the first through seventh scan lines <NUM> through <NUM> include five points, the number of points along each of the first through seventh scan lines <NUM> through <NUM> is not limited to <NUM>.

In an embodiment, the processor (<NUM> of <FIG>) of the ultrasound imaging apparatus <NUM> may extract power data having a value equal to or greater than a predetermined threshold from among power data values of blood flow obtained at the points <NUM> through <NUM> and identify a point having a value of the extracted power data for each of the first through seventh scan lines <NUM> through <NUM>. For example, the processor <NUM> may extract power data having a value exceeding a threshold among power data values respectively measured at a plurality of points, i.e., first through fifth points <NUM> through <NUM>, having different depths along the first scan line <NUM>, and identify the second point <NUM> where the extracted power data is measured from among the first through fifth points <NUM> through <NUM>. Similarly, the processor <NUM> may extract power data having a value exceeding the threshold among power data values respectively measured at a plurality of points, i.e., first through fifth points <NUM> through <NUM>, having different depths along the second scan line <NUM>, and identify the second point <NUM> where the extracted power data is measured from among the first through fifth points <NUM> through <NUM>. In the same manner as described above, the processor <NUM> may respectively identify, as points having a value exceeding the threshold, a third point <NUM> in the third scan line <NUM>, a third point <NUM> in the fourth scan line <NUM>, a fourth point <NUM> in the fifth scan line <NUM>, a fifth point <NUM> in the sixth scan line <NUM>, and a fifth point <NUM> in the seventh scan line <NUM>.

However, a method of identifying a specific point for each scan line is not limited to the above method. According to an embodiment, the processor <NUM> may identify, for each of the first through seventh scan lines <NUM> through <NUM>, a point having a maximum value of the measured power data from among the points <NUM> through <NUM> which are respectively included in the first through seventh scan lines <NUM> through <NUM>.

In an embodiment, the processor <NUM> may obtain the trend line <NUM> indicating the location and direction of blood flow by connecting the second points <NUM> and <NUM>, the third points <NUM> and <NUM>, the fourth point <NUM>, and the fifth points <NUM> and <NUM> where the values of extracted power data are measured.

In an embodiment, the ultrasound imaging apparatus <NUM> may calculate an angle θ between the obtained trend line <NUM> and a scan line <NUM> along which an ultrasound beam is transmitted and correct an angle of a sample volume SV by using the calculated angle θ. According to an embodiment, the processor <NUM> of the ultrasound imaging apparatus <NUM> may calculate an angle θ formed between the trend line <NUM> and the scan line <NUM> where the sample volume SV is located and correct the angle of the sample volume SV by performing an operation of multiplying a velocity of blood flow passing through the sample volume SV by <NUM>/cos θ.

<FIG> is a flowchart of a method performed by the ultrasound imaging apparatus <NUM>, of correcting an angle of a sample volume by using a location and a direction of blood flow, according to an embodiment of the disclosure.

The ultrasound imaging apparatus <NUM> extracts power data having a value greater than or equal to a predetermined threshold from among blood flow power data obtained at a plurality of points in an ROI along a plurality of scan lines (operation S610). According to an embodiment, the ultrasound imaging apparatus <NUM> may extract, for each of a plurality of scan lines, a point having a maximum value of measured power data from among a plurality of points which are respectively included in the scan lines.

The ultrasound imaging apparatus <NUM> obtains a trend line indicating a location and a direction of blood flow by connecting points having values of the extracted power data to one another (operation S620). According to the claimded invention, the ultrasound imaging apparatus <NUM> identifies for each of a plurality of scan lines, a point having a power data value greater than or equal to a predetermined threshold from among power data values of blood flow, obtained at a plurality of points in an ROI. According to another embodiment, the ultrasound imaging apparatus <NUM> may identify a point having a maximum power data value for each of the scan lines from among power data values of blood flow obtained at the points. The ultrasound imaging apparatus <NUM> obtains a trend line indicating a location and a direction of blood flow by connecting the identified points to one another.

The ultrasound imaging apparatus <NUM> calculates an angle between the obtained trend line and a scan line along which an ultrasound beam is transmitted (operation S630). The scan line along which the ultrasound beam is transmitted may be a line passing through a position of a sample volume.

The ultrasound imaging apparatus <NUM> corrects an angle of a sample volume by using the calculated angle (operation S640). In an embodiment, the ultrasound imaging apparatus <NUM> calculates an angle θ formed between a trend line and a scan line where a sample volume is located and corrects an angle of the sample volume by performing an operation of multiplying a velocity of the blood flow passing through the sample volume by <NUM>/cos θ.

<FIG> illustrates an embodiment in which the ultrasound imaging apparatus <NUM> of the disclosure displays a trend line for blood flow on a B-mode ultrasound image <NUM>.

Referring to <FIG>, the display <NUM> of the ultrasound imaging apparatus <NUM> may display the B-mode ultrasound image <NUM>. The display <NUM> may display a trend line <NUM> by overlaying the trend line on a corresponding position on the B- mode ultrasound image <NUM>. According to an embodiment, the display <NUM> may display a GUI representing the trend line <NUM> as a line or image on the B-mode ultrasound image <NUM>.

<FIG> illustrates a frequency spectrum <NUM> obtained by the ultrasound imaging apparatus <NUM> at PRF intervals, according to an embodiment of the disclosure.

Referring to the frequency spectrum <NUM> shown in <FIG>, the ultrasound imaging apparatus <NUM> may obtain a plurality of spectral Doppler pulse waves, i.e., first through fifteenth spectral Doppler pulse waves <NUM> through <NUM>, at a point over time. In an embodiment, the ultrasound imaging apparatus <NUM> may store the first through fifteenth spectral Doppler pulse waves <NUM> through <NUM> obtained in a time series in the storage (<NUM> of <FIG>). An interval between a time point when the first spectral Doppler pulse wave <NUM> is obtained and a time point when the second spectral Doppler pulse wave <NUM> is obtained may be equal to an interval of a PRF. According to an embodiment, the ultrasound imaging apparatus <NUM> may classify the first through fifteenth spectral Doppler pulse waves <NUM> through <NUM> into a plurality of groups by grouping only spectral Doppler pulse waves obtained during a predetermined time period among the first through fifteenth spectral Doppler pulse waves <NUM> through <NUM> stored in the storage <NUM>.

Referring to an embodiment shown in <FIG>, the ultrasound imaging apparatus <NUM> may classify the first through fifth spectral Doppler pulse waves <NUM> through <NUM> as a first group <NUM>-<NUM>, the sixth through tenth spectral Doppler pulse waves <NUM> through <NUM> as a second group <NUM>-<NUM>, and the eleventh through fifteenth spectral Doppler pulse waves <NUM> through <NUM> as a third group <NUM>-<NUM>. Although <FIG> shows that a total number of spectral Doppler pulse waves <NUM> through <NUM> is <NUM> and they are classified into a total of three groups, that is, first, second, and third groups <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM>, this is merely an example. The number of spectral Doppler pulse waves (the first through fifteenth spectral Doppler pulse waves <NUM> through <NUM>) and the number of groups (the first through third groups <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM>) are not limited to the ones shown in <FIG>.

<FIG> is a diagram for describing a method performed by the ultrasound imaging apparatus <NUM>, of updating trend lines <NUM> through <NUM> for blood flow by using power data for spectral Doppler pulse waves obtained based on a predetermined time period, according to an embodiment of the disclosure.

Referring to <FIG>, the ultrasound imaging apparatus <NUM> may sum up, for each of the first through third groups <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM>, power data values of spectral Doppler pulse waves obtained at each of a plurality of points <NUM>-<NUM> through <NUM>-n for each of a plurality of scan lines <NUM> through <NUM>, and calculate an average of power data values for each of the first through third groups <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM>. According to an embodiment, the processor (<NUM> of <FIG>) of the ultrasound imaging apparatus <NUM> may sum up, for each of the points <NUM>-<NUM> through <NUM>-n, power data values of spectral Doppler pulse waves corresponding to a plurality of pieces of Doppler data <NUM>-<NUM> through <NUM>-<NUM> classified as the first group <NUM>-<NUM> according to a predetermined time period, and calculate an average value of power data for each of the points <NUM>-<NUM> through <NUM>-n by performing an operation of dividing a sum of the power data values by the number of the pieces of Doppler data <NUM>-<NUM> through <NUM>-<NUM>. Similarly, the processor <NUM> may sum up, for each of the points <NUM>-<NUM> through <NUM>-n, power data values of spectral Doppler pulse waves corresponding to a plurality of pieces of Doppler data <NUM>-<NUM> through <NUM>-<NUM> classified as the second group <NUM>-<NUM>, and calculate an average value of power data for each of the points <NUM>-<NUM> through <NUM>-n by performing an operation of dividing a sum of the power data values by the number of the pieces of Doppler data <NUM>-<NUM> through <NUM>-<NUM>. The processor <NUM> may calculate, for each of the points <NUM>-<NUM> through <NUM>-n, an average value of power data for spectral Doppler pulse waves corresponding to a plurality of pieces of Doppler data <NUM>-<NUM> through <NUM>-<NUM> classified as the third group <NUM>-<NUM>.

The ultrasound imaging apparatus <NUM> may respectively obtain a plurality of trend lines, i.e., first through third trend lines <NUM> through <NUM>, indicating a location and a direction of blood flow at a plurality of different time points, i.e., first through third time points t1 through t3, by using the average values of power data calculated for the first through third groups <NUM>-<NUM> through <NUM>-<NUM>. According to an embodiment, the processor <NUM> may obtain the first trend line <NUM> indicating a location and a direction of the blood flow at the first time point t1 from Doppler data <NUM>-<NUM> related to the first group <NUM>-<NUM>, which represents average values of power data calculated at each of the points <NUM>-<NUM> through <NUM>-n. Because a method of obtaining the first trend line <NUM> from the Doppler data <NUM>-<NUM> is substantially the same as the method according to the embodiment described with reference to <FIG> and <FIG>, a detailed description thereof will not be repeated below. The processor <NUM> may obtain the second trend line <NUM> indicating a location and a direction of the blood flow at the second time point t2 from Doppler data <NUM>-<NUM> related to the second group <NUM>-<NUM>, which represents average values of power data calculated for each of the points <NUM>-<NUM> through <NUM>-n. An interval between the first time point t1 and the second time point t2 may be equal to a predetermined time period Δt. The time period Δt may be set based on a user input. In the same way, the processor <NUM> may obtain the third trend line <NUM> indicating a location and a direction of the blood flow at the third time point t3 from Doppler data <NUM>-<NUM> related to the third group <NUM>-<NUM>, which represents average values of power data calculated for each of the points <NUM>-<NUM> through <NUM>-n.

The ultrasound imaging apparatus <NUM> may update the first through third trend lines <NUM> through <NUM> according to the predetermined time period Δt. According to an embodiment, the processor <NUM> may respectively display the first through third trend lines <NUM> through <NUM> on the display (<NUM> of <FIG>) at the first through third time points t1 through t3.

<FIG> is a flowchart of a method by which the ultrasound imaging apparatus <NUM> updates a trend line for blood flow by using power data for spectral Doppler pulse waves obtained during a predetermined time period, according to an embodiment of the disclosure.

The ultrasound imaging apparatus <NUM> classifies pieces of Doppler data into a plurality of groups by grouping at least one piece of Doppler data obtained during a predetermined time period (operation S910). According to an embodiment, the ultrasound imaging apparatus <NUM> may classify a plurality of spectral Doppler pulse waves obtained sequentially at PRF intervals into a plurality of groups based on a predetermined time interval.

The ultrasound imaging apparatus <NUM> calculates an average value of power data from at least one piece of Doppler data included in each of the groups (operation S920). According to an embodiment, the ultrasound imaging apparatus <NUM> may sum up power data values of spectral Doppler pulse waves obtained at each of a plurality of points in an ROI for each of a plurality of scan lines, and calculate an average of a sum of the power data values for each of the groups.

The ultrasound imaging apparatus <NUM> obtains a trend line indicating a location and a direction of blood flow by using the calculated average value (operation S930). According to an embodiment, the ultrasound imaging apparatus <NUM> may obtain a trend line by using an average value of power data calculated for each of the groups.

The ultrasound imaging apparatus <NUM> updates a location and a direction of the trend line at predetermined time intervals (operation S940). According to an embodiment, the ultrasound imaging apparatus <NUM> may display the trend line updated at the predetermined time intervals on the display (<NUM> of <FIG>).

In the related art, when the direction of blood flow is changed due to a patient's random motion or breathing, the user is inconvenienced in having to repeatedly correct an angle of a sample volume, which degrades the accuracy of measuring a blood flow velocity.

The ultrasound imaging apparatus <NUM> according to the embodiment described with reference to <FIG>, <FIG>, and <FIG> may update a trend line indicating a location and a direction of blood flow at predetermined time intervals, thereby allowing the user to identify in real-time the location and direction of blood flow which change due to a patient's breathing or random motion and correct an angle of a sample volume by using the trend line updated in real-time. Accordingly, this may improve the accuracy of measuring a blood flow velocity.

<FIG> is diagram illustrating ultrasound diagnosis apparatus according to an exemplary embodiment.

<FIG> is diagram illustrating ultrasound imaging apparatus according to an exemplary embodiment.

Referring to <FIG> and <FIG>, ultrasound imaging apparatuses 1000a and 1000b may include a main display <NUM> and a sub-display <NUM>. At least one among the main display <NUM> and the sub-display <NUM> may include a touch screen. The main display <NUM> and the sub-display <NUM> may display ultrasound images and/or various information processed by the ultrasound imaging apparatuses 1000a and 1000b. The main display <NUM> and the sub-display <NUM> may provide GUIs, thereby receiving user's inputs of data to control the ultrasound imaging apparatuses 1000a and 1000b. For example, the main display <NUM> may display an ultrasound image and the sub-display <NUM> may display a control panel to control display of the ultrasound image as a GUI. The sub-display <NUM> may receive an input of data to control the display of an image through the control panel displayed as a GUI. The ultrasound imaging apparatuses 1000a and 1000b may control the display of the ultrasound image on the main display <NUM> by using the input control data.

Referring to <FIG>, the ultrasound imaging apparatus 1000b may include a control panel <NUM>. The control panel <NUM> may include buttons, trackballs, jog switches, or knobs, and may receive data to control the ultrasound imaging apparatus 1000b from the user. For example, the control panel <NUM> may include a time gain compensation (TGC) button <NUM> and a freeze button <NUM>. The TGC button <NUM> is to set a TGC value for each depth of an ultrasound image. Also, when an input of the freeze button <NUM> is detected during scanning an ultrasound image, the ultrasound imaging apparatus 1000b may keep displaying a frame image at that time point.

The buttons, trackballs, jog switches, and knobs included in the control panel <NUM> may be provided as a GUI to the main display <NUM> or the sub-display <NUM>.

<FIG> is diagram illustrating an ultrasound imaging apparatus according to an exemplary embodiment.

Referring to <FIG>, the ultrasound imaging apparatus 1000c may include a portable device. An example of a portable ultrasound imaging apparatus may include, for example, smart phones including probes and applications, laptop computers, personal digital assistants (PDAs), or tablet PCs, but an exemplary embodiment is not limited thereto.

The ultrasound imaging apparatus 1000c may include the probe <NUM> and a main body <NUM>. The probe <NUM> may be connected to one side of the main body <NUM> by wire or wirelessly. The main body <NUM> may include a touch screen <NUM>. The touch screen <NUM> may display an ultrasound image, various pieces of information processed by the ultrasound imaging apparatus 1000c, and a GUI.

The embodiments may be implemented as a software program including instructions stored in a computer-readable storage medium.

A computer may refer to a device configured to retrieve an instruction stored in the computer-readable storage medium and to operate, in response to the retrieved instruction, and may include an ultrasound imaging apparatus according to embodiments.

The computer-readable storage medium may be provided in the form of a non-transitory storage medium. In this regard, the term 'non-transitory' means that the storage medium does not include a signal and is tangible, and the term does not distinguish between data that is semi-permanently stored and data that is temporarily stored in the storage medium.

In addition, the ultrasound imaging apparatus or the method of controlling the ultrasound imaging apparatus according to embodiments may be provided in the form of a computer program product. The computer program product may be traded, as a product, between a seller and a buyer.

The computer program product may include a software program and a computer-readable storage medium having stored thereon the software program. For example, the computer program product may include a product (e.g. a downloadable application) in the form of a software program electronically distributed by a manufacturer of the ultrasound imaging apparatus or through an electronic market (e.g., Google ™, Play Store ™, and App Store ™). For such electronic distribution, at least a part of the software program may be stored on the storage medium or may be temporarily generated. In this case, the storage medium may be a storage medium of a server of the manufacturer, a server of the electronic market, or a relay server for temporarily storing the software program.

In a system consisting of a server and a terminal (e.g., the ultrasound imaging apparatus), the computer program product may include a storage medium of the server or a storage medium of the terminal. Alternatively, in a case where a third device (e.g., a smartphone) that communicates with the server or the terminal is present, the computer program product may include a storage medium of the third device. Alternatively, the computer program product may include a software program that is transmitted from the server to the terminal or the third device or that is transmitted from the third device to the terminal.

In this case, one of the server, the terminal, and the third device may execute the computer program product, thereby performing the method according to embodiments. Alternatively, at least two of the server, the terminal, and the third device may execute the computer program product, thereby performing the method according to embodiments in a distributed manner.

For example, the server (e.g., a cloud server, an artificial intelligence (AI) server, or the like) may execute the computer program product stored in the server, and may control the terminal to perform the method according to embodiments, the terminal communicating with the server.

As another example, the third device may execute the computer program product, and may control the terminal to perform the method according to embodiments, the terminal communicating with the third device. In more detail, the third device may remotely control the ultrasound imaging apparatus to emit X-rays to an object, and to generate an image of an inner part of the object, based on detected radiation which passes the object and is detected in an X-ray detector.

As another example, the third device may execute the computer program product, and may directly perform the method according to embodiments, based on at least one value input from an auxiliary device (e.g., a gantry of a CT system). In more detail, the auxiliary device may emit X-rays to an object and may obtain information of radiation which passes the object and is detected in an X-ray detector. The third device may receive an input of signal information about the detected radiation from the auxiliary device, and may generate an image of an inner part of the object, based on the input radiation information.

Claim 1:
A method of operating an ultrasonic imaging device (<NUM>) comprising:
transmitting (S210) an ultrasound beam to a region of interest (ROI) including a sample volume in an object;
obtaining Doppler data with respect to a plurality of points in the ROI based on a plurality of scan lines by using a multiline receiving technique;
measuring a velocity of a blood flow passing through the sample volume based on the obtained Doppler data;
obtaining blood flow power data from the Doppler data obtained at the plurality of the points in the ROI;
obtaining (S620, S940) a trend line indicating a location and a direction of the blood flow based on the blood flow power data obtained at the plurality of points in the ROI;
calculating (S630) an angle between the obtained trend line and a scan line where the sample volume is located; and
correcting the measured velocity of the blood flow passing through the sample volume by using the calculated angle,
wherein the obtaining of the trend line comprises:
extracting (S610) power data having a value greater than or equal to a predetermined threshold from among the blood flow power data obtained at the plurality of the points in the ROI;
identifying, for each of the plurality of the scan lines, a point having a value of the extracted power data, from among the plurality of the points in the ROI; and
connecting the points to one another.