WO2015041380A1

WO2015041380A1 - Harmonic imaging method and ultrasound medical device for same

Info

Publication number: WO2015041380A1
Application number: PCT/KR2013/008446
Authority: WO
Inventors: 구자운; 장선엽; 손건호; 강승범
Original assignee: 알피니언메디칼시스템 주식회사
Priority date: 2013-09-17
Filing date: 2013-09-17
Publication date: 2015-03-26
Also published as: KR20150032058A; KR101510678B1

Abstract

A harmonic imaging method and an ultrasound medical device for the same are disclosed. As a technique for generating and image-processing an N-th order harmonic image, provided are a harmonic imaging method capable of improving a frame rate by transmitting plane waves having a phase difference and synthesizing reflected signals corresponding to the plane waves by using a pipeline method, and an ultrasound medical device for the same.

Description

Harmonic Image Forming Method And Ultrasound Medical Device For Him

The present embodiment relates to a harmonic image forming method and an ultrasonic medical device therefor.

It should be noted that the contents described below merely provide background information related to the present embodiment and do not constitute a prior art.

The ultrasound imaging system transmits ultrasound to an object, receives a reflection signal reflected within the object, and converts the received reflection signal into an electrical signal to form an ultrasound image. Harmonic Imaging has been proposed as part of increasing the resolution of ultrasound images in ultrasound imaging systems. When transmitting an ultrasonic pulse of a specific frequency and receiving a reflected signal, the reflected signal reflected from the human body includes a fundamental frequency component and a harmonic component. Most of the harmonic components are second harmonic components with twice the intensity of the fundamental frequency. In general, in harmonic image formation, only the second harmonic component is separated to form an ultrasound image.

Harmonic components have a narrow beam width and low side lobes compared to the fundamental frequency. Accordingly, the ultrasound image formed of the harmonic component improves the resolution and the contrast of the ultrasound image formed of the fundamental frequency component. However, in the case of the pulse inversion method used to extract harmonic components, there is a problem in that the frame rate is lowered.

The present embodiment is a technique for generating and processing an N-th harmonic image and transmitting a plane wave having a phase difference, and synthesizing a corresponding reflected signal in a pipe-line manner to frame rate. It is a main object to provide a harmonic image forming method capable of improving) and an ultrasonic medical device therefor.

According to an aspect of the present embodiment, a transducer for transmitting a plane wave (Plane Wave) to the object and receiving a reflected signal corresponding to the plane wave from the object; A transmitter for causing the plane wave to have a phase difference of 360 ° / N (N is a natural number of 2 or more), and the plane wave to be sequentially transmitted to the object; A harmonic acquiring unit for generating an N-th harmonic component by synthesizing only the most recent N signals among the received reflection signals in a pipe-line manner; And a signal processor configured to process the N-th harmonic component into data for displaying.

According to another aspect of the present invention, there is provided a method of forming a harmonic image by an ultrasonic medical apparatus, comprising: a transmission control process of setting a phase to have a phase difference of 360 ° / N (N is a natural number of two or more); A receiving step of sequentially transmitting a plane wave having a phase difference of 360 ° / N to an object and receiving a reflected signal corresponding to the plane wave from the object; A harmonic acquisition process of generating N-th harmonic components by synthesizing the most recent N signals sequentially received from the reflected signals in a pipe-line manner; And a signal processing process of processing the N-th harmonic component as data for displaying the harmonic image.

As described above, according to the present embodiment, as a technique for generating and processing an N-th harmonic image, a plane wave having a phase difference is transmitted, and the corresponding reflected signal is synthesized in a pipe-line manner to improve the frame rate. It has an effect.

In addition, according to the present embodiment, there is an effect that the frame rate is improved compared to the conventional harmonic image acquisition method of the pulse inversion method. By implementing harmonic image processing using planar waves having a phase difference, which is different from existing harmonic image processing apparatuses, image quality is improved compared to existing equipments, and it has an effect of providing differentiated harmonic image processing with a fast frame rate. .

1 is a block diagram schematically showing the ultrasound medical apparatus according to the present embodiment.

2 is a block diagram schematically illustrating a harmonic acquisition unit according to the present embodiment.

3 is a flowchart illustrating a harmonic image forming method according to the present embodiment.

4 is a flowchart illustrating a phase correction method according to the present embodiment.

5 is a diagram for describing a method for obtaining N-th harmonic according to the present embodiment.

Hereinafter, the present embodiment will be described in detail with reference to the accompanying drawings.

The ultrasound medical apparatus 100 according to the present embodiment may include a transducer 110, a transmission / reception switch 122, a transmitter 132, a receiver 134, an analog-to-digital converter 140, a beamformer 150, The harmonic acquiring unit 160, the signal processor 170, and the scan converter 180 are included. Components of the ultrasound medical apparatus 100 according to the present embodiment are not necessarily limited thereto.

The transducer 110 converts an electrical analog signal into ultrasonic waves and transmits the ultrasonic wave to an object, and converts a signal reflected from the object (hereinafter, referred to as a reflection signal) into an electrical analog signal. In general, the transducer 110 is formed by combining a plurality of transducer elements. The transducer 110 converts acoustic energy into an electrical signal and converts electrical energy into acoustic energy. In addition, the transducer 110 may be implemented as an array transducer, and transmits an ultrasonic wave to an object and receives a reflected signal reflected from the object by using the transducer element in the array transducer.

The transducer 110 may include a plurality of transducer elements (eg, 128), and output ultrasonic waves in response to a voltage applied from the transmitter 132. In this case, only some transducer elements of the plurality of transducer elements may be used for ultrasonic transmission. For example, even when the transducer 110 includes 128 transducer elements, only 64 transducer elements may transmit ultrasonic waves to form one transmission scanline during the ultrasonic transmission. The transducer 110 can be used for both reception and transmission. The transducer 110 may be implemented as a plurality of 1D (Dimension), 1.25D, 1.5D, 1.75D or 2D array transducer.

Also, the transducer 110 transmits the focused ultrasound to the object along the transmission scan line by appropriately delaying an input time of pulses input to each transducer element under the control of the beamformer 150. On the other hand, the reflected signal reflected from the object corresponding to the ultrasonic wave is input to the transducer 110 with different reception times, and the transducer 110 outputs the reflected signal input from the object to the beamformer 150. . The transducer 110 according to the present embodiment transmits a plane wave to an object and receives a reflection signal corresponding to the plane wave from the object. In this case, the reflected signal is a signal corresponding to the plane wave, and may be subjected to high-speed imaging by software.

The transmission / reception switch 122 performs a function of switching the transmitter 132 and the receiver 134 so that the transducer 110 alternately performs transmission or reception. In addition, the transmission and reception switch 122 serves to prevent the voltage output from the transmitter 132 does not affect the receiver 134.

The transmitter 132 applies a voltage pulse to the transducer 110 so that ultrasonic waves are output from each transducer element of the transducer 110. The transmitter 132 according to the present exemplary embodiment applies a voltage pulse to the transducer 110 so that a plane wave is output from each transducer element of the transducer 110. At this time, the transmitter 132 sets the phase so that the plane wave output from the transducer 110 has a phase difference of 360 ° / N (N is a natural number of 2 or more). The transmitter 132 transmits the plane wave including the phase having a phase difference of 360 ° / N by the transducer 110 to the object in sequence. For example, when N is set to 2, the transmitter 132 is set to have a phase of 0 ° and a phase of 180 ° so that the plane wave of the transducer 110 has a phase difference of 180 °. In addition, when N is set to 3, the transmitter 132 sets a phase of 0 °, a phase of 120 °, and a phase of 240 ° such that the plane wave of the transducer 110 has a phase difference of 120 °.

The receiver 134 receives the reflected signal from which the ultrasonic wave output from each transducer element of the transducer 110 is reflected from the object, and amplifies, aliases, and noise components of the received reflected signal. A post-processed signal, such as removal and correction of attenuation generated while the ultrasound passes through the body, is transmitted to the analog-to-digital converter 140.

The analog-to-digital converter 140 converts the analog reflection signal received from the receiver 134 into a digital signal and transmits the converted signal to the beam forming unit 156. The reflection signal received by the analog-to-digital converter 140 from the transducer 110 is in the form of an analog, which is a voltage of a continuous signal. In this case, the analog signal must first be converted into a digital signal before being processed by the scan converter 180. Therefore, the analog-to-digital converter 140 converts each analog signal into a combination of 0's and 1's. For example, the analog-to-digital converter 140 represents an analog signal in the form of 0's and 1's in order to digitally represent the signal, and the digital signal is stored in the memory of the scan converting unit 180 via the signal processing unit 170. . In addition, the analog-to-digital converter 140 converts the reflected signal into a digital signal.

Here, the transmission / reception switch 122, the transmitter 132, the receiver 134, and the analog to digital converter 140 may be implemented as a front end 120.

The beamformer 150 converts the electrical signal suitable for the transducer 110 into an electrical signal suitable for each transducer element. In addition, the beamformer 150 delays or sums the electric signals converted by each transducer element to calculate the output value of the corresponding transducer element. The beamformer 150 includes a transmit beamformer, a receive beamformer, and a beam former 156. Here, the transmission beamformer corresponds to the transmission focus delay unit 152 and the reception beamformer corresponds to the reception focus delay unit 154. The beamformer 150 according to the present embodiment generates the first delay time required to focus the ultrasound to the enlarged region or the second delay time required to focus the plane wave on the object, and then the first delay time or the second delay time. A combined signal is generated by combining each of the applied digital signals into one signal. On the other hand, the beamformer 150 may be connected to the analog-to-digital converter 140 and the signal processor 170 in a full parallel path by software for high-speed imaging.

The transmission focus delay unit 152 applies an appropriate delay to each electric digital signal in consideration of the time to reach each transducer element from the object (diagnosis object). For example, the transmission focus delay unit 152 adjusts and electronically focuses the beam when the transducer 110 is an array type transducer. For example, since the array transducers are electronically focused according to different depths, the transmission focusing delay unit 152 focuses the beam on the transmitting side by continuously giving a pulse delay time to each of the array transducer elements. As a result, the transmission focus delay unit 152 may adjust the direction of the beam with respect to the array-type transducer that is scanned electronically. The reception focusing delay unit 154 generates a delay time required for focusing or beamforming the digital signal converted by the analog-to-digital converter 140. For example, the reception focusing delay unit 154 provides a time delay for focusing the reflected signal received from the transducer 110 and adjusts the dynamic focusing of the reflected signal.

The beam forming unit 156 may form a receive focusing signal by summing the electrical digital signals converted by the analog to digital converter 140. The beam forming unit 156 combines the digitized signal into one signal. At this time, the reflected signal of the same phase is combined in the beam forming unit 156, and various signal processing methods are applied in the signal processing unit 170 and then output from the display unit provided through the scan converter 180. The beam forming unit 156 applies dynamic delay amounts (determined according to the position to be focused) to the signals received from the analog-to-digital converter 140 and synthesizes the delayed signals by synthesizing the delayed signals. Do this. For example, the beamformer 156 combines the reflected signals received from each of the transducer elements into one signal for later signal processing. The beam forming unit 156 generates a combined signal in which one signal is combined with reflection signals received from all the transducer elements in order to produce a single reflection signal for each reflector (object). The generated combination signal is transmitted to the signal processing unit 170 by the beam forming unit 156 and finally to a digitalizing device that converts the digital signal into a digital form for storing image data.

The harmonic acquisition unit 160 according to the present embodiment synthesizes only the most recent N signals among the sequentially received reflection signals in a pipe-line manner to generate an N-th harmonic component. Here, 'pipe-line' refers to the continuous, somewhat overlapping movement of instructions to the processor (or the arithmetic steps taken by the processor to perform the instructions). For example, using a 'pipe-line', the processor may fetch the next instruction while performing an arithmetic operation, and put the instruction into a buffer near the processor until the next instruction operation can be performed. Thus, the step of getting instructions continues endlessly, resulting in an increase in the number of instructions that can be executed in a given time.

In addition, when the harmonic acquisition unit 160 synthesizes the most recent N signals among the reflected signals sequentially received to generate the Nth harmonic component, the fundamental frequency component is lost and only the Nth harmonic component remains. For example, when N is 2, only the second harmonic component remains, and when N is 3, only the third harmonic component remains.

For example, based on the phase difference, the harmonic acquisition unit 160 has a sum of phase differences (180 ° + 180 °, 120 ° + 120 ° + 120 °, etc.) included in the reflected signal in a pipe-line manner. It is possible to generate an N-th harmonic component to form a frame by forming 360 °.

Referring to the process of forming the first frame by the harmonic acquisition unit 160, the harmonic acquisition unit 160 synthesizes the correction data according to the transmission of the N plane waves when the first frame is formed. For example, the harmonic acquiring unit 160 generates the Nth harmonic component by synthesizing the N reflected signals after the transducer 110 transmits the plane wave and waits until the number of received reflected signals becomes N. Next, the process of forming the frame by the harmonic acquisition unit 160, the harmonic acquisition unit 160 synthesizes the correction data generated for each plane wave newly transmitted by the transducer 110 after the first frame is formed in the receiving order Allow a new frame to form. For example, after the first frame is formed, the harmonic acquiring unit 160 combines the reflection signal received each time the transducer 110 transmits a new plane wave with the reflection signal received in the most recent N signals. Only Nth harmonic components can be generated by synthesizing Bay.

The process of correcting the phase included in the reflected signal by the harmonic obtaining unit 160 will be described. The harmonic acquiring unit 160 stores reflection signals sequentially received in the N memories, generates a phase analysis result of analyzing phase components included in the stored reflection signal, and based on the generated phase analysis result. Phase shift is performed to generate correction data. Thereafter, the harmonic acquisition unit 160 generates an Nth harmonic component for synthesizing the most recent N data among the generated correction data in a pipe-line manner to form a frame.

Hereinafter, a process of checking the phase difference by the harmonic obtaining unit 160 to correct the phase included in the reflected signal will be described. The harmonic acquisition unit 160 checks whether or not a phase difference between phases included in each of the reflected signals stored in the memory 220 occurs by 360 ° / N. If the difference occurs by 360 ° / N, the harmonic acquisition unit 160 recognizes that a phase difference equal to the phase difference of 360 ° / N set by the transmitter 132 is generated and phases the reflected signal stored in the memory 220. A phase analysis result is generated to cause the shift to be not performed, and correction data without the phase shift is generated based on the generated phase analysis result. On the other hand, if the difference does not occur by 360 ° / N as a result of the check, the harmonic acquisition unit 160 recognizes that the phase difference that is not the same as the phase difference of 360 ° / N set by the transmitter 132 occurred in the memory 220 A phase analysis result for right shifting the stored reflection signal by a phase corresponding to the unit sample time is generated, and based on the generated phase analysis result, right-shifted correction data is generated by the phase corresponding to the unit sample time. For example, the unit sample time may be 25 ns in a 40 MHz sampling system.

The signal processor 170 changes the reflected signal of the received scan line focused by the beam forming unit 156 into baseband signals and detects an envelope by using a quadrature demodulator. Get data for the scanline. In addition, the signal processor 170 processes the data generated by the beamformer 150 into a digital signal. The signal processor 170 according to the present exemplary embodiment processes the Nth harmonic component as data for displaying.

The signal processor 170 may process the corresponding data in parallel in software in order to perform high-speed imaging of the reflected signal corresponding to the plane wave. For example, the signal processor 170 compares an input data string with a comparison data string for high speed image processing, generates a comparison result data string, extracts a representative bit from each comparison result data constituting the comparison result data string, A representative bit string is generated by the bits, and a plurality of operation data strings corresponding to the bit patterns that can be represented by the representative bit string are stored in a table, and a specific operation data string selected among the plurality of operation data strings according to the representative bit string is selected. Can be used to generate a data stream of emissions by performing data operations on the input data stream. As described above, parallel processing is performed for high-speed imaging of the signal processing unit 170, but the architecture (architecture) is a multi-core CPU (Central Processing Unit) and GPU (Graphic Processing Unit) at the same time thousands of channels You can do parallel processing in.

The scan converter 180 records the data obtained by the signal processor 170 in a memory, matches the scanning direction of the data with the pixel direction of the display unit (eg, the monitor), and maps the data to the pixel position of the display unit. . The scan converter 180 converts the ultrasound image data into a data format used in a display unit of a predetermined scan line display format.

The memory of the scan converter 180 may be recognized as a matrix of elements configured in a multi-bit storage unit for the ultrasound image data received from a preset location. Here, the digitized element is called a pixel. For example, the memory of the scan converter 180 is a matrix of such pixels. The ultrasound image data output on the display unit is actually present in the form of a matrix of digital numbers in the memory of the scan converter 180. For example, during the ultrasonic image formation, the reflected signal is embedded at the position (address) of the pixel according to the position of the object. The scan converter 180 uses the delay time of the reflected signal and the beam coordinates of the transducer 110 to calculate the correct pixel address.

In this case, the scan converter 180 is used on at least 8 bits to express the value of the reflection signal on each pixel position. For example, 8 bits have 256 amplitude levels in each position. The memory of the scan converter 180 is continuously updated with new reflection signal information as the ultrasound beam forms an ultrasound image of a region of interest (ROI). On the other hand, in the image stop function of the scan converter 180, the reflected signal may be stored in the memory not only for image recording but also for storing photographs and digital information. The memory of the scan converter 180 is output by transferring pixel values to a digital-to-analog converter (DAC) that supplies a signal necessary to adjust the brightness intensity of the display unit.

In addition, the beamformer 150, the harmonic acquirer 160, the signal processor 170, and the scan converter 180 may be implemented as a host 190. In this case, the host 190 may be implemented including a CPU and a GPU. The front end processor 120 and the host 190 may be connected to, for example, a Peripheral Component Interconnect (PCI) interface.

Meanwhile, the ultrasound medical apparatus 100 may further include a user input unit, and the user input unit receives an instruction by a user's manipulation or input. Here, the user command may be a setting command for controlling the ultrasound medical apparatus 100.

The harmonic acquisition unit 160 according to the present embodiment includes a phase analyzer 210, a memory 220, a phase shifter 230, and a synthesizer 240. The components of the harmonic acquisition unit 160 according to the present embodiment are not necessarily limited thereto.

The phase analyzer 210 generates a phase analysis result of analyzing the phase component included in the reflected signal. Here, the phase analysis 210 may use a Fast Fourier Transform (FFT) to analyze the phase component included in the reflected signal. Referring to the process of checking the phase difference to correct the phase included in the reflected signal by the phase analyzer 210, the phase analyzer 210 determines that the phase difference between the phases included in each of the reflected signals stored in the memory 220 is increased. Check whether there is a difference of 360˚ / N. As a result of the check, if the difference occurs by 360 ° / N, the phase analyzer 210 recognizes that a phase difference equal to the phase difference of 360 ° / N set by the transmitter 132 is generated and phases the reflected signal stored in the memory 220. Generate a phase analysis result that causes the shift to fail. On the other hand, if the difference does not occur by 360 ° / N as a result of the check, the phase analysis unit 210 recognizes that the phase difference is not the same as the phase difference of 360 ° / N set by the transmitter 132 and the memory 220 A phase analysis result is generated to shift the reflected signal stored in the right side by a phase corresponding to the unit sample time.

In more detail, the operation of the phase analyzer 210 is described. The phase analyzer 210 stores the first reflection signal stored in the first storage area of the memory 220 and the N-th storage area of the memory 220. When the phase difference between the phases included in the N reflected signals is different by 360 ° / N, a phase analysis result is generated such that a phase shift is not performed on the first reflected signal and the N reflected signals. The phase analyzer 210 may have a phase difference between the first reflection signal stored in the first storage area of the memory 220 and the phase included in the N reflection signal stored in the Nth storage area of the memory 220 greater than 360 ° / N. And a phase difference that is not equal to the phase difference of 360 ° / N set by the transmitter 132 to generate a phase analysis result for right shifting the first reflected signal by a phase corresponding to the unit sample time. do. In addition, the phase analyzer 210 may have a phase difference of 360 ° / N between a first reflection signal stored in the first storage area of the memory 220 and a phase included in the N reflection signal stored in the Nth storage area of the memory 220. If it is less than, it is recognized that a phase difference that is not the same as the phase difference of 360 ° / N set by the transmitter 132 and the phase analysis result to the right to shift the N-th reflected signal by a phase corresponding to the unit sample time Create

Hereinafter, the operation of the phase analyzer 210 will be described assuming N as a natural number of 3 or more. The phase analyzer 210 has a phase difference of 360 ° between an N-1 reflected signal stored in the N-1th storage area of the memory 220 and a phase included in the N reflected signal stored in the Nth storage area of the memory 220. When a difference occurs by / N, a phase analysis result is generated such that a phase shift is not performed on the N-1th reflected signal and the Nth reflected signal. On the other hand, the phase analyzer 210 has a phase difference between the N-1 reflected signal stored in the N-1th storage area of the memory 220 and the phase included in the N reflected signal stored in the Nth storage area of the memory 220. If it occurs more than 360 ° / N, it is recognized that a phase difference that is not equal to the phase difference of 360 ° / N set by the transmitter 132 is generated, and the N-1 reflected signal is right by the phase corresponding to the unit sample time. Generate a phase analysis result that causes the shift. In addition, the phase analyzer 210 may determine a phase difference between an N-1 reflected signal stored in the N-1th storage area of the memory 220 and a phase included in the N reflected signal stored in the Nth storage area of the memory 220. If it occurs less than 360 ° / N, it is recognized that a phase difference that is not the same as the phase difference of 360 ° / N set by the transmitter 132 is generated so that the N-th reflected signal is shifted right by a phase corresponding to the unit sample time. Generate phase analysis results.

The memory 220 is a storage unit that stores sequentially received reflection signals. The memory 220 may be physically implemented as one storage module and internally allocate N storage areas. In other words, the memory 220 allocates a first storage area storing a first reflected signal corresponding to the first plane wave to an Nth storage area storing an Nth reflected signal corresponding to the Nth plane wave. For example, since the memory 220 sets the phase difference of 360 ° / N in the transmitter 132, the memory 220 may allocate the same number of storage areas as the N set in the transmitter. Here, the memory 220 is not necessarily limited to one physical storage module.

For example, when N is assumed to be 3, the transmitter 132 sets the phase of 0 °, the phase of 120 °, and the phase of 240 ° so that the plane wave of the transducer 110 has a phase difference of 120 °. 220 includes a first storage area, a second storage area (N-first memory area), and a third storage area (N-th storage area). Here, the first reflected signal corresponding to the first plane wave having the phase of 0 ° is stored in the first storage area, and the second reflected signal corresponding to the second plane wave having the phase of 120 ° is stored in the second storage area (first And a third reflected signal corresponding to the third plane wave having a phase of 240 degrees, is stored in the third storage region (N-th storage region). At this time, the first plane wave having a phase of 0 ° again after all of the data (reflection signal) is stored in the first storage region, the second storage region (N-first storage region), and the third storage region (N-th storage region). When the first reflection signal corresponding to the second reflection signal is received, the newly received first reflection signal may be updated and stored in the first storage area.

The phase shift unit 230 generates correction data of performing or not performing a phase shift based on the phase analysis result. The phase shift unit 230 confirms the phase analysis result received from the phase analysis unit 210, and when the check result and the phase analysis result include the phase shift non-execution information, the phase shift unit does not have a phase shift based on the phase analysis result. Generate the correction data performed. In addition, when the phase shift information is included in the phase analysis result as a result of the check, the phase shift unit 230 generates correction data shifted right by a phase corresponding to the unit sample time based on the phase shift information. The phase shift unit 230 basically performs a right shift when shifting the reflected signal stored in the memory 220.

Referring to the process of the phase shift unit 230 performs the phase shift, the phase shift unit 230 includes a phase analysis result received from the phase analyzer 210 included in the first reflection signal and the Nth reflection signal. When the phase difference between phases exceeds 360 ° / N, correction data is generated by shifting the right reflection signal by one phase corresponding to the unit sample time. The phase shift unit 230 is the N-th reflection signal when the phase analysis result received from the phase analyzer 210 generates a phase difference between a phase included in the first reflection signal and the N-th reflection signal to be less than 360 ° / N. Is generated by correcting the right shift by a phase corresponding to the unit sample time.

For example, the operation of the phase shift unit 230 based on the reflected signal having a phase will be described. For example, the phase shift unit 230 may be a reflection signal having a phase analysis result of the phase analyzer 210 having a 0 ° phase and 360 degrees. Calculate the phase difference of the reflected signal with ˚ / N phase, and generate the correction data by shifting the reflected signal with 360 ˚ / N phase by the phase corresponding to the unit sample time when the phase difference occurs more than 360˚ / N do. In addition, the phase shifter 230 calculates a phase difference between the reflection signal having the phase analysis unit 210 and the reflection signal having the 360 ° / N phase, and the phase difference is less than 360 ° / N. When generated as is, the correction data is generated by shifting a reflected signal having a 0 ° phase by a phase corresponding to a unit sample time.

The combiner 240 generates an N-th harmonic component for synthesizing the most recent N pieces of correction data in a pipe-line manner to form one frame. The synthesizing unit 240 synthesizes correction data according to transmission of N plane waves at the time of initial frame formation, and then synthesizes correction data generated for each newly transmitted plane wave in order of reception so that a new frame is formed.

Hereinafter, the synthesis process of the synthesis unit 240 will be described on the assumption that N is 3. When N is 3, the transmitter 132 sets a phase of 0 °, a phase of 120 °, and a phase of 240 ° such that the plane wave of the transducer 110 has a phase difference of 120 °, and thus has a phase of 0 °. Assuming that the first reflection signal corresponding to the first plane wave is 'A ₁ ', the second reflection signal corresponding to the second plane wave having a phase of 120 ° is assumed to be 'B ₁ ', and has a phase of 240 °. Assume that the third reflected signal corresponding to the third plane wave is 'C ₁ '. Thereafter, the synthesis unit 240 performs the order 'A ₁ + B ₁ + C ₁ ' such that the sum (120 ° + 120 ° + 120 °) of the phase difference included in the first to third reflected signals is 360 °. The reflected signal may be synthesized to form a first frame. Subsequently, assuming that a new first reflected signal corresponding to a new first plane wave having a phase of 0 ° is 'A ₂ ' (A ₁ and A ₂ are data having the same phase received at different times, respectively), the synthesis unit ( 240 may form the second frame by synthesizing the reflected signals in the order of 'B ₁ + C ₁ + A ₂ ' such that the sum of phase differences (120 ° + 120 ° + 120 °) is 360 °. In addition, assuming that a new second reflected signal corresponding to a new second plane wave having a phase of 120 ° is 'B ₂ ', the synthesis unit 240 has a sum of phase difference (120 ° + 120 ° + 120 °) of 360 °. The third frame may be formed by synthesizing the reflected signals in the order of 'C ₁ + A ₂ + B ₂ ' to form a.

The ultrasound medical apparatus 100 sets the phase so that the plane wave output from the transducer 110 has a phase difference of 360 ° / N (N is a natural number of 2 or more) (S310). For example, in step S310, when N is set to 2, the ultrasound medical apparatus 100 sets the phase of 0 ° and the phase of 180 ° so that the plane wave of the transducer 110 has a phase difference of 180 °, and N is 3. When set to 0, the phase of 0 °, the phase of 120 °, and the phase of 240 ° are set so that the plane wave of the transducer 110 has a phase difference of 120 °. The ultrasound medical apparatus 100 outputs a plane wave having a phase difference of 360 ° / N to the object using the transducer 110 (S320).

The ultrasound medical apparatus 100 receives the reflected signals corresponding to the plane waves from the object by using the transducer 110 and stores them in the N memories 220 (S330). In operation S330, the memory 220 sequentially stores the N memory 220 sequentially storing the sequentially received reflection signals. For example, the memory 220 may include a first storage area storing a first reflected signal corresponding to the first plane wave and an Nth storage area storing an Nth reflected signal corresponding to the Nth plane wave. For example, when N is assumed to be 3, the transmitter 132 sets the phase of 0 °, the phase of 120 °, and the phase of 240 ° so that the plane wave of the transducer 110 has a phase difference of 120 °. 220 includes a first storage area, a second storage area (N-first storage area), and a third storage area (N-th storage area). Here, the first reflected signal corresponding to the first plane wave having the phase of 0 ° is stored in the first storage area, and the second reflected signal corresponding to the second plane wave having the phase of 120 ° is stored in the second storage area (first And a third reflected signal corresponding to the third plane wave having a phase of 240 degrees, is stored in the third storage region (N-th storage region).

The ultrasound medical apparatus 100 generates a phase analysis result of analyzing a phase component included in the reflected signal, and generates correction data in which phase shift is performed when phase shift is necessary based on the phase analysis result (S340). In operation S340, the ultrasound medical apparatus 100 checks whether a phase difference between phases included in each of the reflected signals stored in the memory 220 occurs by 360 ° / N. As a result of the check, if the difference occurs by 360 ° / N, the ultrasound medical apparatus 100 recognizes that a phase difference equal to the phase difference of 360 ° / N set by the transmitter 132 occurs and phases the reflected signal stored in the memory 220. A phase analysis result is generated to cause the shift to be not performed, and correction data without the phase shift is generated based on the generated phase analysis result. On the other hand, if the difference does not occur by 360 ° / N as a result of the check, the ultrasound medical apparatus 100 recognizes that the phase difference that is not the same as the phase difference of 360 ° / N set by the transmitter 132 occurred in the memory 220 A phase analysis result for right shifting the stored reflection signal by a phase corresponding to the unit sample time is generated, and based on the generated phase analysis result, right-shifted correction data is generated by the phase corresponding to the unit sample time.

The ultrasound medical apparatus 100 generates N-th harmonic components by synthesizing only the most recent N signals sequentially among received correction data (or reflected signals) in a pipe-line manner, and displays N-th harmonic components as data. Process (S350).

In FIG. 3, steps S310 to S350 are described as being sequentially executed, but are not necessarily limited thereto. For example, since the steps described in FIG. 3 may be applied by changing or executing one or more steps in parallel, FIG. 3 is not limited to the time series order.

As described above, the harmonic image forming method according to the present embodiment described in FIG. 3 may be implemented in a program and recorded on a computer-readable recording medium. The computer-readable recording medium having recorded thereon a program for implementing the harmonic image forming method according to the present embodiment includes all kinds of recording devices storing data that can be read by a computer system.

In FIG. 4, for convenience of explanation, it is assumed that N is a natural number of 3 or more, and the ultrasound medical apparatus 100 will be described with reference to a method of correcting phase.

The ultrasound medical apparatus 100 calculates a phase difference between the first reflection signal stored in the first storage area of the memory 220 and the phase included in the second reflection signal stored in the second storage area of the memory 220 (S410). The ultrasound medical apparatus 100 may have a phase difference between the first reflection signal stored in the first storage area of the memory 220 and the phase included in the second reflection signal stored in the second storage area of the memory 220 equal to 360 ° / N. Check whether or not (S412). As a result of checking in step S412, the phase difference between the first reflection signal stored in the first storage region of the memory 220 and the phase included in the second reflection signal stored in the second storage region of the memory 220 is equal to 360 ° / N. After performing the phase shift on the first reflected signal and the second reflected signal, the ultrasound medical apparatus 100 performs the second reflected signal stored in the N-1 storage area of the memory 220 and the second reflected signal of the memory 220. The phase difference between the phases included in the two reflected signals stored in the two storage areas is calculated (S414).

The ultrasound medical apparatus 100 has a phase difference of 360 ° between an N-1 reflected signal stored in the N-1th storage area of the memory 220 and a phase included in the N reflected signal stored in the Nth storage area of the memory 220. Check whether or not equal to / N (S416). As a result of confirming in step S416, the phase difference between the N-1th reflected signal stored in the N-1st storage area of the memory 220 and the phase included in the N reflected signal stored in the Nth storage area of the memory 220 is 360 ° / If it is equal to N, the ultrasound medical apparatus 100 generates a phase analysis result for performing a phase shift on the N-th reflected signal and the N-reflected signal and considers that phase correction is completed (S418).

As a result of checking in step S412, the phase difference between the first reflection signal stored in the first storage region of the memory 220 and the phase included in the N-1 reflection signal stored in the N-1 storage region of the memory 220 is 360 ° / If not equal to N, the ultrasound medical apparatus 100 includes the first reflection signal stored in the first storage area of the memory 220 and the N-1 reflection signal stored in the N-1 storage area of the memory 220. It is checked whether the phase difference between the phases exceeds 360 ° / N (S420).

As a result of checking in S420, a phase difference between a phase included in the first reflection signal stored in the first storage area of the memory 220 and the second reflection signal stored in the second storage area of the memory 220 is less than 360 ° / N. In this case, the ultrasound medical apparatus 100 recognizes that a phase difference that is not equal to the phase difference of 360 ° / N set by the transmitter 132 is generated and causes the second reflected signal to be shifted right by a phase corresponding to the unit sample time. (S422). The process then returns to step S410. On the other hand, as a result of confirming in step S420, the phase difference between the first reflection signal stored in the first storage region of the memory 220 and the phase included in the second reflection signal stored in the second storage region of the memory 220 is 360 ° / N In the event of excessive occurrence, the ultrasound medical apparatus 100 recognizes that a phase difference that is not equal to the phase difference of 360 ° / N set by the transmitter 132 is generated, and the first reflected signal is right by a phase corresponding to the unit sample time. To shift (S424). The process then returns to step S410.

As a result of confirming in step S416, the phase difference between the N-1th reflected signal stored in the N-1st storage area of the memory 220 and the phase included in the N reflected signal stored in the Nth storage area of the memory 220 is 360 ° / If not equal to N, the ultrasound medical apparatus 100 includes the N-1 reflected signal stored in the N-1th storage area of the memory 220 and the N reflected signal stored in the Nth storage area of the memory 220. It is checked whether or not the phase difference between the phases exceeds 360 ° / N (S430).

As a result of checking in step S430, the phase difference between the N-1 th reflection signal stored in the N-1 th storage area of the memory 220 and the phase included in the N reflection signal stored in the N th storage area of the memory 220 is 360 ° / If less than N, the ultrasound medical apparatus 100 recognizes that a phase difference that is not equal to the phase difference of 360 ° / N set by the transmitter 132 is generated, and the N-th reflected signal is converted by the phase corresponding to the unit sample time. The right shift is made (S432). The process then returns to step S414. On the other hand, as a result of confirming in step S430, the phase difference between the N-1 reflected signal stored in the N-1th storage area of the memory 220 and the phase included in the N reflected signal stored in the Nth storage area of the memory 220 is 360 In the case of more than ˚ / N, the ultrasound medical apparatus 100 recognizes that a phase difference that is not the same as the phase difference of 360 ° / N set by the transmitter 132 is generated, and the N-1 reflected signal is converted into a unit sample time. The right shift is performed by a phase corresponding to S S434. The process then returns to step S414.

In FIG. 4, steps S410 to S434 are sequentially executed, but the present disclosure is not limited thereto. For example, FIG. 4 is not limited to time-series order as it would be applicable to changing the steps described in FIG. 4 or executing one or more steps in parallel.

As described above, the phase correction method according to the present embodiment described in FIG. 4 may be implemented in a program and recorded on a computer-readable recording medium. The computer-readable recording medium having recorded thereon a program for implementing the phase correction method according to the present embodiment includes all kinds of recording devices that store data that can be read by a computer system.

In FIG. 5, it is assumed that N is 3 for convenience of description. Since N is 3 in the transmitter 132 of the ultrasound medical apparatus 100, the phase of 0 °, the phase of 120 °, and the phase of 240 ° are set such that the plane wave of the transducer 110 has a phase difference of 120 °. Accordingly, the transducer 110 of the ultrasound medical apparatus 100 transmits a first plane wave having a phase of 0 ° to the object and receives a first reflected signal corresponding to the first plane wave. Here, the first reflected signal is referred to as 'A ₁ ', and the ultrasound medical apparatus 100 stores 'A ₁ ' in the first storage area of the memory 220.

In addition, the transducer 110 of the ultrasound medical apparatus 100 transmits a second plane wave having a phase of 120 ° to the object, and receives a second reflected signal corresponding to the second plane wave. Here, the second reflected signal is referred to as 'B ₁ ', and the ultrasound medical apparatus 100 stores 'B ₁ ' in the second (N-1) storage area of the memory 220. In addition, the transducer 110 of the ultrasound medical apparatus 100 transmits a third plane wave having a phase of 240 ° to the object, and receives a third reflected signal corresponding to the third plane wave. Here, the third reflected signal is referred to as 'C ₁ ', and the ultrasound medical apparatus 100 stores 'C ₁ ' in the third (N) storage area. The synthesizer 240 of the ultrasound medical apparatus 100 combines the most recent three (N) signals among the reflected signals in the order of 'A ₁ + B ₁ + C ₁ ' to form a first frame.

Thereafter, the transducer 110 of the ultrasound medical apparatus 100 transmits a new first plane wave having a phase of 0 ° to the object and receives a first reflected signal corresponding to the new first plane wave. Here, the new first reflected signal is referred to as 'A ₂ ', and after storing 'A ₂ ' in the first storage area of the memory 220, the ultrasound medical apparatus 100 reflects the received reflected signal. A second frame is formed by synthesizing the last three (N) signals in the order of 'B ₁ + C ₁ + A ₂ ' in a form of combining with a signal.

Thereafter, the transducer 110 of the ultrasound medical apparatus 100 transmits a new second plane wave having a phase of 120 ° to the object and receives a second reflected signal corresponding to the new second plane wave. Here, the new second reflected signal is referred to as 'B ₂ ', and after storing 'B ₂ ' in the second storage area of the memory 220, the ultrasound medical apparatus 100 reflects the received reflected signal. A third frame may be formed by synthesizing the last three (N) signals in the order of 'C ₁ + A ₂ + B ₂ ' in a form of combining with a signal.

On the other hand, the synthesis unit 240 of the ultrasound medical apparatus 100 is' A ₁ + B so that the sum (120˚ + 120˚ + 120˚) of the phase difference included in the first reflected signal to the third reflected signal is 360 ° Synthesizing the reflected signal in the order ₁ + C ₁ 'to form a first frame, synthesizing the reflected signal in the order' B ₁ + C ₁ + A ₂ 'to form a second frame, and' C ₁ + A ₂ + The reflected signal may be synthesized in the order of B ₂ ′ to form a third frame.

In the general pulse inversion method, the reflection signals are synthesized in the order of 'A ₁ + B ₁ + C ₁ ' to form a first frame, and then new reflection signals A ₂ , B ₂ and C ₂ are received. After waiting until the reflection signal of A ₂ , B ₂ , C ₂ is received, the second frame is formed by synthesizing the reflection signals in the order of 'A ₂ + B ₂ + C ₂ '. Will fall. However, the ultrasound medical apparatus 100 according to the present embodiment waits until the reflection signals of A ₁ , B ₁ , and C ₁ are received only when the first frame is formed, and then the reflection signals of A ₁ , B ₁ , and C ₁ are received. When all are received, the reflection signal is synthesized in the order of 'A ₁ + B ₁ + C ₁ ' to form a first frame. For example, when the ultrasound medical apparatus 100 receives a reflected signal, eg, A ₂ , which is received every time a new plane wave is transmitted, the ultrasound medical apparatus 100 combines with the previously received reflection signals B ₁ and C ₁ to B ₁ + C ₁ + A. The Nth harmonic component can be generated by synthesizing ₂ with the most recent N signals.

The ultrasound medical apparatus 100 according to the present exemplary embodiment transmits a plane wave having a phase of 360 ° / N from the transducer 110 to an object to be inspected or inside the body (object) at regular intervals, The reflection signal corresponding to the plane wave from the (object) is received in a pipe-line manner at a predetermined interval every PRF (Pulse Repetition Frequency) and stored in the memory 220. In FIG. 5, for example, in order to acquire third harmonics, a reflection signal (third reflection signal) having a third phase of 240 ° obtained by the ultrasound medical apparatus 100 may be a first 0 ° reflection signal ( Combined with A) and the second 120 ° reflected signal (B) (A ₁ + B ₁ + C ₁ ), the first third harmonic component is produced. In the second third harmonic generation process, A _{1 previously} stored in the memory 220 is discarded in real time, and B ₁ and C ₁ remain. The ultrasound medical apparatus 100 undergoes a process of adding existing B ₁ and C ₁ data and A ₂ obtained in real time (B ₁ + C ₁ + A ₂ ) when acquiring a new A ₂ from the next scan line. You can get four frames. In addition, the ultrasound medical apparatus 100 includes a phase analyzer 210 capable of analyzing the phase of the received reflected signal (RF data), and has a phase difference of 360 ° using the phase analysis of the phase analyzer 210. If it does not occur as much as / N, you can finely control the phase of each waveform so that the analyzed harmonics come out best.

The above description is merely illustrative of the technical idea of the present embodiment, and those skilled in the art to which the present embodiment belongs may make various modifications and changes without departing from the essential characteristics of the present embodiment. Therefore, the present embodiments are not intended to limit the technical idea of the present embodiment but to describe the present invention, and the scope of the technical idea of the present embodiment is not limited by these embodiments. The scope of protection of the present embodiment should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present embodiment.

(Explanation of the sign)

100: ultrasound medical device

110: transducer 122: transmission and reception switch

132: transmitter 134: receiver

140: analog to digital converter 150: beamformer

160: harmonic acquisition unit 170: signal processing unit

180: scan conversion unit 210: phase analysis unit

220: memory 230: phase shift unit

240: synthesis section

CROSS-REFERENCE TO RELATED APPLICATION

This patent application claims priority under Patent Application No. 10-2013-0112050, filed with Korea on September 17, 2013, pursuant to Article 119 (a) (35 USC § 119 (a)). All content is incorporated by reference in this patent application. In addition, if this patent application claims priority for the same reason for countries other than the United States, all its contents are incorporated into this patent application by reference.

Claims

A transducer for transmitting a plane wave to an object and receiving a reflected signal corresponding to the plane wave from the object;

A transmitter for causing the plane wave to have a phase difference of 360 ° / N (N is a natural number of 2 or more), and the plane wave to be sequentially transmitted to the object;

A harmonic acquiring unit for generating an N-th harmonic component by synthesizing only the most recent N signals among the received reflection signals in a pipe-line manner; And

Signal processing unit for processing the N-th harmonic components as data for display

Ultrasound medical device comprising a.
The method of claim 1,

The harmonic acquisition unit,

A memory for allocating N regions each of which sequentially stores the reflected signals;

A phase analyzer configured to generate a phase analysis result of analyzing phase components included in the reflected signal;

A phase shift unit configured to generate correction data of performing or not performing a phase shift based on the phase analysis result; And

Synthesis unit for generating the N-th harmonic component to form a frame by synthesizing the most recent N of the correction data in a pipe-line method

Ultrasound medical device comprising a.
The method of claim 2,

The synthesis unit,

Ultrasonic medical device characterized in that to synthesize the correction data according to the transmission of the N plane waves when the first frame is formed, and then to synthesize the correction data generated for each newly transmitted plane wave in order of reception to form a new frame .
The method of claim 2,

The phase analyzer determines whether a phase difference between phases included in each of the reflected signals occurs by 360 ° / N, and if the difference occurs by 360 ° / N as a result of the checking, a phase shift is not applied to the reflected signal. Generate the phase analysis result to be performed,

And the phase shift unit generates the correction data without performing the phase shift based on the phase analysis result.
The method of claim 2,

The phase analyzer determines whether a phase difference between phases included in each of the reflected signals is different by 360 ° / N, and if the difference is not generated by 360 ° / N as a result of the checking, unit samples the reflected signal. (Sample) to generate the phase analysis result to the right (Right Shift) by a phase corresponding to the time,

And the phase shift unit generates the correction data shifted right by a phase corresponding to the unit sample time based on the phase analysis result.
The method of claim 2,

The memory,

A first storage region storing a first reflected signal corresponding to the first plane wave; And

Nth storage area for storing the Nth reflected signal corresponding to the Nth plane wave

Ultrasound medical device comprising a.
The method of claim 6,

When the phase difference between the phase included in the first reflected signal and the Nth reflected signal is different by 360 ° / N, the phase analyzer may not perform a phase shift on the first reflected signal and the Nth reflected signal. Generate the phase analysis result,

And the phase shift unit generates the correction data without performing the phase shift based on the phase analysis result.
The method of claim 6,

When the phase difference between the first reflection signal and the phase included in the N-th reflection signal is greater than 360 ° / N, the phase analyzer may shift the first reflection signal right by a phase corresponding to a unit sample time. Generating the phase analysis result,

And the phase shift unit generates the correction data by right shifting the first reflection signal by a phase corresponding to a unit sample time based on the phase analysis result.
The method of claim 6,

When the phase difference between the first reflection signal and the phase included in the N-th reflection signal is less than 360 ° / N, the phase analyzer causes the N-th reflection signal to be shifted right by a phase corresponding to a unit sample time. Generating the phase analysis result,

And the phase shift unit generates the correction data by right shifting the N reflected signal by a phase corresponding to a unit sample time based on the phase analysis result.
In the ultrasonic medical device to form a harmonic image,

A transmission control process of setting a phase to have a phase difference of 360 ° / N (N is a natural number of 2 or more);

A receiving step of sequentially transmitting a plane wave having a phase difference of 360 ° / N to an object and receiving a reflected signal corresponding to the plane wave from the object;

A harmonic acquisition process of generating N-th harmonic components by synthesizing the most recent N signals sequentially received from the reflected signals in a pipe-line manner; And

Signal processing process for processing the N-th harmonic components as data for display

Harmonic image forming method comprising a.
The method of claim 10,

The harmonic acquisition process,

A storage process of sequentially storing the reflected signals received in the N storage areas;

A phase analysis process of generating a phase analysis result of performing a phase shift on a corresponding reflected signal when a phase difference between phases included in each of the reflected signals is equal to 360 ° / N;

Generating a phase shift correction data based on the phase analysis result; And

Synthesis process of generating N-th harmonic components to form one frame by synthesizing the most recent N data among the correction data in a pipe-line manner

Ultrasound medical device comprising a.
The method of claim 10,

The harmonic acquisition process,

A storage process of sequentially storing the reflected signals received in the N storage areas;

A phase analysis process of generating a phase analysis result of causing a right shift of the reflected signal by a phase corresponding to a unit sample time when a phase difference between phases included in each of the reflected signals is not equal to 360 ° / N;

A phase shift process of generating the correction data shifted right by a phase corresponding to a unit sample time based on the phase analysis result; And

Synthesis process of generating N-th harmonic components to form one frame by synthesizing the most recent N data among the correction data in a pipe-line manner

Ultrasound medical device comprising a.