Ultrasonic diagnostic apparatus

Abstract

The invention provides an ultrasonic diagnostic apparatus. The purpose of the present invention is to set the display state of a Doppler waveform so that the Doppler waveform can be easily seen. An ultrasound diagnostic device (100) is provided with a transmission unit (12), a reception unit (20), and an information processing unit (26). The transmission unit (12) transmits ultrasonic waves to a subject (18) by means of an ultrasonic probe (14). The reception unit (20) receives ultrasonic waves reflected by a subject (18) by means of an ultrasonic probe (14). The information processing unit (26) performs processing on the reception signal output from the reception unit (20). The information processing unit generates Doppler waveform data on the basis of the received signal, determines whether the observation site is an artery or a vein on the basis of the Doppler waveform data, and determines the display range of the blood flow velocity indicated by the Doppler waveform on the basis of the determination result.

Description

Technical Field

[0001] The present invention relates to an ultrasonic diagnostic device, and in particular to a processing method when displaying a Doppler waveform. Background Art

[0002] Ultrasonic diagnostic devices that observe an object by transmitting and receiving ultrasonic waves are widely used. Generally, ultrasonic diagnostic devices have a function of displaying a Doppler waveform indicating blood flow velocity. Waveform characteristic values ​​such as the maximum value, minimum value, and average value of the Doppler waveform vary depending on the observed part. Therefore, a technology is considered to adjust the scale when displaying the Doppler waveform so that the user can easily observe the Doppler waveform.

[0003] Patent document 1 below states that the Doppler velocity range is adjusted based on the statistical value of the distribution of at least one of the maximum velocity and the average velocity of the trace waveform in the frequency direction of the spectrum signal. Patent document 1 also states that multiples of the estimated values ​​of the upper limit and the lower limit of the baseline and velocity range set within the display range are obtained based on the positive maximum value and the negative maximum value.

[0004] Patent document 2 describes that in an ultrasonic color Doppler imaging system, whether the blood vessel to be diagnosed is an artery or a vein is determined based on the pulsation index PT and the resistance index RI of the blood flow velocity. Patent document 3 describes a technology for generating Doppler image data representing blood flow velocity by color.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2010-88943

[0006] Patent Document 2: Japanese Patent Application Laid-Open No. 11-235342

[0007] Patent Document 3: Japanese Patent Application Publication No. 2016-87302

[0008] The waveform characteristic value of the Doppler waveform varies depending on the observation site. Therefore, if the Doppler waveform is displayed at a constant ratio, it may be difficult to observe the Doppler waveform. Summary of the invention

[0009] An object of the present invention is to set a display state of a Doppler waveform so that the Doppler waveform can be easily viewed.

[0010] The ultrasonic diagnostic device of the present invention is characterized in that it comprises: a transmitting unit, which transmits ultrasonic waves to a subject through an ultrasonic probe; a receiving unit, which receives the ultrasonic waves reflected in the subject through the ultrasonic probe; and an information processing unit, which processes a received signal output from the receiving unit, wherein the information processing unit performs the following processing: generates Doppler waveform data based on the received signal; determines whether the observed part is an artery or a vein based on the Doppler waveform data; and determines the display range of the blood flow velocity represented by the Doppler waveform based on the determination result.

[0011] Furthermore, the ultrasonic diagnostic apparatus of the present invention is characterized in that it comprises: a transmitting unit, which transmits ultrasonic waves to a subject through an ultrasonic probe; a receiving unit, which receives the ultrasonic waves reflected in the subject through the ultrasonic probe; and an information processing unit, which processes a received signal output from the receiving unit, wherein the information processing unit performs the following processing: generates Doppler waveform data based on the received signal; determines whether the observed part is an artery or a vein based on the deviation of the Doppler frequencies of the plurality of received signals obtained based on multiple ultrasonic transmissions and receptions; and determines the display range of the blood flow velocity represented by the Doppler waveform based on the determination result.

[0012] Furthermore, the ultrasonic diagnostic apparatus of the present invention is characterized in that it comprises: a transmitting unit, which transmits ultrasonic waves to a subject through an ultrasonic probe; a receiving unit, which receives the ultrasonic waves reflected in the subject through the ultrasonic probe; and an information processing unit, which processes a received signal output from the receiving unit, wherein the information processing unit performs the following processing: generates Doppler waveform data and color Doppler data based on the received signal; determines whether the observed part is an artery or a vein based on the color Doppler data; and determines the display range of the blood flow velocity represented by the Doppler waveform based on the determination result.

[0013] Preferably, the information processing unit determines whether the observation site is an artery or a vein based on whether a folding phenomenon occurs in the color Doppler data.

[0014] Preferably, the information processing unit determines a scale factor when displaying the Doppler waveform based on the determination result.

[0015] Preferably, the information processing unit performs the following processing: obtaining a reference value of the Doppler waveform line obtained from the Doppler waveform data, and determining the proportional factor based on an area of ​​a region between the Doppler waveform line obtained from the Doppler waveform data and a reference line represented by the reference value in addition to the determination result.

[0016] Preferably, the information processing unit performs processing to obtain a maximum value, a minimum value, and a reference value of a Doppler waveform line obtained from the Doppler waveform data, and determine the scale factor based on the maximum value, the minimum value, and the reference value in addition to the determination result.

[0017] Preferably, the information processing unit determines whether the observation site is an artery or a vein based on a time differential value of a Doppler waveform obtained from the Doppler waveform data.

[0018] Preferably, the information processing unit determines whether the observation site is an artery or a vein based on a time-integrated value of a Doppler waveform line obtained from the Doppler waveform data.

[0019] Preferably, the information processing unit determines whether the observation site is an artery or a vein based on whether a folding phenomenon occurs in the Doppler waveform data.

[0020] Preferably, a pulsation detection device for detecting the pulsation of the subject is provided, and the information processing unit determines whether the observation site is an artery or a vein at a timing corresponding to the pulsation of the subject.

[0021] Preferably, a repetition frequency at which the transmitting unit transmits the ultrasonic wave is set according to the display range.

[0022] Effects of the Invention

[0023] According to the present invention, the display state of the Doppler waveform can be set so that the Doppler waveform can be easily viewed. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a diagram showing the structure of an ultrasonic diagnostic apparatus.

[0025] Figure 2 It is a diagram showing an example of a Doppler waveform.

[0026] Figure 3 It is a diagram showing an example of a B-mode color Doppler image and a Doppler waveform.

[0027] Figure 4 It is a diagram showing the Doppler waveform line together with the Doppler waveform.

[0028] Figure 5 It is a diagram showing the Doppler waveform E(t) and the polarity of its time differential value.

[0029] Figure 6 It is a diagram showing the Doppler waveform line and the evaluation area.

[0030] Figure 7It is a diagram showing an example of a B-mode color Doppler image and a Doppler waveform.

[0031] Figure 8 It is a diagram showing the Doppler waveform line together with the Doppler waveform.

[0032] Fig. 9 It is a diagram showing an example of a B-mode color Doppler image and a Doppler waveform.

[0033] Fig.10 It is a diagram showing the Doppler waveform line together with the Doppler waveform.

[0034] Fig.11 It is a diagram showing the update timing of the scale factor.

[0035] Fig.12 It is a diagram showing the update timing of the scale factor.

[0036] Explanation of symbols

[0037] 10-beam control unit, 12-transmitting unit, 14-ultrasonic probe, 16-vibrating element, 18-subject, 20-receiving unit, 22-control unit, 24-operating unit, 26-information processing unit, 30-phase addition unit, 32-B mode image generating unit, 34-image processing unit, 36-Doppler processing unit, 38-Doppler waveform generating unit, 40-color Doppler processing unit, 42-display unit, 52-baseline, 54-beam line, 56-Doppler gate, 58-update time, 60-Doppler waveform, 70-pulsation detection device, 100-ultrasonic diagnostic device. DETAILED DESCRIPTION

[0038] The embodiments of the present invention will be described with reference to the drawings. The same components shown in the multiple drawings are denoted by the same reference numerals and their descriptions are omitted. Figure 1 2 shows a configuration of an ultrasonic diagnostic apparatus 100 according to an embodiment of the present invention. The ultrasonic diagnostic apparatus 100 includes a beam control unit 10 , a transmitter 12 , an ultrasonic probe 14 , a receiver 20 , a controller 22 , an operation unit 24 , an information processor 26 , and a display unit 42 .

[0039] The information processing unit 26 may be composed of one or more processors, and the processors realize the functions of the phasing and adding unit 30, the B-mode image generating unit 32, the image processing unit 34, the Doppler processing unit 36, the Doppler waveform generating unit 38, and the color Doppler processing unit 40 by executing programs. The control unit 22 performs overall control of the ultrasonic diagnostic apparatus 100. The operation unit 24 includes a keyboard, a mouse, a lever, a button, a voice recognition device, etc., and outputs information related to user operations to the control unit 22. The control unit 22 controls the ultrasonic diagnostic apparatus 100 according to the operation of the operation unit 24.

[0040] The operation unit 24 can constitute a user interface for operating the ultrasonic diagnostic apparatus 100 together with the display unit 42. For example, the operation unit 24 can include a touch panel in the display screen of the display unit 42. In addition, the operation unit 24 can have a function of operating a keyboard, a lever, a button, etc. virtually configured on the display screen. The control unit 22 can also output information acquired through the user interface to the information processing unit 26.

[0041] The operation of the ultrasonic diagnostic apparatus 100 will be briefly described. The ultrasonic diagnostic apparatus 100 transmits ultrasonic waves from the ultrasonic probe 14 to the subject 18, and receives the ultrasonic waves reflected by the subject 18 by the ultrasonic probe 14. The ultrasonic diagnostic apparatus 100 performs various measurements in B mode, Doppler mode, and color Doppler mode.

[0042] In the B-mode operation, the ultrasonic diagnostic apparatus 100 generates B-mode image data based on the ultrasonic waves received from the subject 18, and displays the B-mode image on the display unit 42. In the Doppler mode operation, the ultrasonic diagnostic apparatus 100 generates Doppler waveform data about blood flow based on the Doppler frequency shift of the ultrasonic waves received from the subject 18, and displays the Doppler waveform on the display unit 42. In the color Doppler mode operation, the ultrasonic diagnostic apparatus 100 generates image data representing an image with a color corresponding to the blood flow velocity in the B-mode image, and displays an image based on the image data on the display unit 42. Only one of the B-mode operation, the Doppler mode operation, and the color Doppler mode operation may be performed, or measurement based on two or three of these three modes may be performed in a time-division manner.

[0043] The specific structure of the ultrasonic diagnostic apparatus 100 and the specific processing performed by the ultrasonic diagnostic apparatus 100 are described. The ultrasonic probe 14 is set to a state of contact with the surface of the subject 18. The ultrasonic probe 14 includes a plurality of vibrating elements 16. The transmitting unit 12 outputs a transmission signal to each vibrating element 16 of the ultrasonic probe 14 according to the control based on the beam control unit 10. As a result, ultrasonic waves are transmitted from the ultrasonic probe 14. The beam control unit 10 forms a transmission beam in the ultrasonic probe 14 by controlling the transmitting unit 12, and scans the transmission beam on the subject 18. That is, the transmitting unit 12 adjusts the delay time or level of each transmission signal according to the control of the beam control unit 10, forms a transmission beam in the ultrasonic probe 14, and scans the transmission beam on the subject 18.

[0044] When each vibration element 16 of the ultrasonic probe 14 receives the ultrasonic wave reflected in the subject 18, each vibration element 16 outputs an electrical signal corresponding to the received ultrasonic wave to the receiving unit 20. The vibration element receiving unit 20 performs amplification, detection, band limiting and other processing on the received signal output from each vibration element 16 according to the control of the beam control unit 10, and outputs it to the information processing unit 26. The information processing unit 26 performs the processing performed by each component (phasing and adding unit 30, B-mode image generating unit 32, image processing unit 34, Doppler processing unit 36, Doppler waveform generating unit 38 and color Doppler processing unit 40) on each received signal.

[0045] The phasing and adding unit 30 performs phasing and adding of the plurality of receiving signals output from the receiving unit 20 to the plurality of vibration elements 16, and generates a phased receiving signal. Thus, a phased receiving signal is generated in which the phases are adjusted and added in a manner that the receiving signals based on the ultrasound waves received from a specific direction are mutually enhanced, and a receiving beam is formed in the specific direction. When the phasing and adding unit 30 operates in the B mode, the phased receiving signal is output to the B mode image generating unit 32. Furthermore, when the phasing and adding unit 30 operates in the Doppler mode, the phased receiving signal is output to the Doppler processing unit 36, and when the phasing and adding unit 30 operates in the color Doppler mode, the phased receiving signal is output to the color Doppler processing unit 40.

[0046] The operation in the B mode is described. The phase addition unit 30 generates each phased reception signal based on the ultrasound waves received from each direction of the reception beam scanned in the subject 18, and outputs it to the B mode image generation unit 32. The B mode image generation unit 32 generates B mode image data based on the phased reception signal obtained for each reception beam direction, and outputs it to the image processing unit 34. The B mode image data based on one scan of the transmission beam and the reception beam (hereinafter referred to as the transmission and reception beam) is one frame of image data, corresponding to one B mode image.

[0047] The beam control unit 10, the transmitting unit 12, the ultrasonic probe 14, the receiving unit 20, the phasing and adding unit 30, and the B-mode image generating unit 32 successively generate B-mode image data while repeatedly scanning the transmitting and receiving beams, and output each B-mode image data to the image processing unit 34. The image processing unit 34 generates a video signal representing a B-mode image based on the B-mode image data, and outputs it to the display unit 42. The display unit 42 displays the B-mode image based on the video signal.

[0048] The operation in Doppler mode is described below. The Doppler mode includes a PW Doppler mode (Pulsed Wave Doppler mode) that transmits ultrasonic pulses at a repetition frequency PRF and a CW Doppler mode (Continuous Wave Doppler mode) that continuously transmits ultrasonic waves. The user can select whether to operate in the PW Doppler mode or the CW Doppler mode through operation.

[0049] The Doppler processing unit 36 ​​sequentially performs fast Fourier transform processing on the phased received signals divided into predetermined time lengths, sequentially generates spectrum data of Doppler frequency shift as time passes, and outputs it to the Doppler waveform generating unit 38. Here, the Doppler frequency shift is a frequency indicating the deviation of the frequency of the received signal from the frequency of the transmitted signal.

[0050] The Doppler waveform generation unit 38 generates Doppler waveform data based on a plurality of sets of spectrum data sequentially output over time. Figure 2 , an example of a Doppler waveform represented by Doppler waveform data is shown. The horizontal axis of the Doppler waveform represents time, and the vertical axis represents Doppler frequency shift. The Doppler frequency shift shown on the vertical axis represents the blood flow velocity. At a certain moment on the time axis, the brightness of a plurality of pixels arranged vertically represents the spectrum corresponding to that moment. The baseline 52 extending in a straight line in the horizontal direction represents the Doppler frequency shift, that is, the blood flow velocity is 0.

[0051] The Doppler waveform generation unit 38 updates the Doppler waveform data sequentially as time goes by. That is, the Doppler waveform generation unit 38 deletes the first spectrum data obtained from the Doppler waveform data composed of a series of spectrum data, and adds the latest spectrum data to the Doppler waveform data to update the Doppler waveform data. The image processing unit 34 generates a video signal representing the Doppler waveform based on the Doppler waveform data, and outputs it to the display unit 42. The display unit 42 displays the Doppler waveform based on the video signal.

[0052] The action in the color Doppler mode is explained. When the color Doppler processing unit 40 generates color Doppler data, multiple (J times) ultrasonic transmission and reception are performed in each direction of the transceiver beam. Here, J is an integer greater than 2. The color Doppler processing unit 40 generates color Doppler data based on the phased received signal obtained by acquiring J times in each direction of the transceiver beam. Color Doppler data is data that uses color to represent the blood flow velocity on the B-mode image of the area scanned by the transceiver beam. Color Doppler data can be, for example, the following data: the area where the blood flows in the direction away from the ultrasonic probe 14 is marked with blue, and the area where the blood flows in the direction close to the ultrasonic probe 14 is marked with red, and the area with a greater blood flow velocity has a greater brightness.

[0053] The color Doppler processing unit 40 obtains the blood flow velocity v(r) in the depth direction of the transmission and reception beams based on the plurality of J types of phased reception signals, for example, according to the autocorrelation process shown in Patent Document 3. Here, v(r) represents the blood flow velocity at the depth r. The color Doppler processing unit 40 generates color Doppler data based on the blood flow velocity v(r) in the depth direction at each depth r obtained for each direction of the transmission and reception beams, and outputs the data to the image processing unit 34. The specific process of obtaining the blood flow velocity v(r) is described below.

[0054] The phase-aligned received signal obtained in the qth (q=1 to J) among the 1st to Jth is expressed by the following equation (Equation 1).

[0055] [Formula 1]

[0056] z(r, q)=I(r, q)+j·Q(r, q)

[0057] r is the coordinate value in the depth direction. T(r, q) represents the in-phase component of the received signal after phase adjustment, and Q(r, q) represents the quadrature component of the received signal after phase adjustment. j is an imaginary unit. The color Doppler processing unit 40 calculates the autocorrelation value A(r) for the J received signals z(r, 1), z(r, 2), ... z(r, J) after phase adjustment according to (Formula 2).

[0058] [Formula 2]

[0059]

[0060] Here, the superscript "*" indicates a conjugate complex number. The color Doppler processing unit 40 uses the real part Re[A(r)] and the imaginary part Im[A(r)] of the autocorrelation value A(r) to obtain the blood flow velocity v(r) according to (Formula 3).

[0061] [Formula 3]

[0062]

[0063] c is the propagation velocity of the ultrasonic wave propagating in the subject 18, and f0 is the frequency of the ultrasonic wave transmitted and received by the ultrasonic probe 14. The right side portion of c / (2f0) in the right side of (Formula 3) represents the Doppler frequency. The blood flow velocity v(r) represents the depth direction component of the blood flow velocity at the depth r. When the angle φ formed by the blood flow direction with respect to the depth direction is known, v(r) / cosφ is the blood flow velocity.

[0064] When the absolute value of the blood flow velocity (e.g., the value in the MKSA system) does not need to be obtained, such as when measuring the blood flow velocity distribution, the blood flow velocity may be a value obtained by multiplying an arbitrary constant by the value obtained by the formula (Formula 3). In addition, the right side portion of c / (2f0) on the right side of (Formula 3), i.e., the Doppler shift measurement value, may be used instead of the blood flow velocity.

[0065] The image processing unit 34 generates data representing a B-mode color Doppler image in which a color corresponding to the blood flow velocity is given to the B-mode image based on the B-mode image data and the color Doppler data. The image processing unit 34 generates a video signal representing the B-mode color Doppler image based on the B-mode color Doppler image data, and outputs the video signal to the display unit 42. The display unit 42 displays the B-mode color Doppler image based on the video signal.

[0066] The image processing unit 34 may display the B-mode image and the Doppler waveform side by side on the display unit 42. Furthermore, the image processing unit 34 may display the B-mode color Doppler image and the Doppler waveform side by side on the display unit 42.

[0067] exist Figure 3 4 shows an example of a B-mode color Doppler image and a Doppler waveform displayed on the display unit 42. The B-mode color Doppler image is shown on the left, and the Doppler waveform is shown on the right. Each image is acquired near the mitral valve in the heart. The area indicated by hatching in the B-mode color Doppler image is an area to which color is assigned.

[0068] The beam line 54 and the Doppler gate 56 indicating the direction of the transmission and reception beam in the Doppler mode are shown on the B-mode color Doppler image. Here, the Doppler gate 56 refers to the range for measuring the blood flow velocity on the transmission and reception beam, and is set in the image of the blood vessel appearing in the B-mode image. The area sandwiched by two parallel straight lines intersecting the beam line 54 is the Doppler gate 56, and the blood flow velocity is measured within this range. The beam line 54 and the Doppler gate 56 are set by the control unit 22 according to the user's operation on the operation unit 24.

[0069] When the image processing unit 34 displays the Doppler waveform, the image processing unit 34 executes a scaling process. Scaling is a process of determining the ratio of the swing amplitude of the Doppler waveform to the display range in the vertical axis direction of the display image.

[0070] exist Figure 4A Doppler waveform for illustrating scaling is shown in . In the longitudinal direction of the display image, the p-axis is defined as the longitudinal axis of the image coordinate system. The coordinate value of the p-axis represents the longitudinal position in the display image. And, the horizontal axis represents time. The image processing unit 34 calculates the display width Vs for each positive and negative value based on the value represented by the Doppler waveform, as described later. The image processing unit 34 also establishes a corresponding association between the positive value Vs of the display width of the Doppler waveform and the upper limit value of the p-axis in the image coordinate system, and establishes a corresponding association between the negative value -Vs of the display width of the Doppler waveform and the lower limit value of the p-axis. Thus, the display range of the blood flow velocity represented by the Doppler waveform is determined to be above -Vs and below Vs.

[0071] The scaling performed by the image processing unit 34 is described in detail. The image processing unit 34 obtains the Doppler waveform line E(t) based on the Doppler waveform data. The Doppler waveform line E(t) can be the envelope of the Doppler waveform. That is, the Doppler waveform line E(t) can be defined as a curve in which the spectral component values ​​corresponding to each time on the negative side of the Doppler waveform line E(t) reach above a prescribed threshold in the positive region above the baseline 52. Furthermore, the Doppler waveform line E(t) can be defined as a curve in which the spectral component values ​​corresponding to each time on the positive side of the Doppler waveform line E(t) reach above a prescribed threshold in the negative region below the baseline 52. Figure 4 , the Doppler waveform line E(t) is shown together with the Doppler waveform.

[0072] The image processing unit 34 sets N as a positive integer, for example, and obtains the average value of the Doppler waveform within a time range of N heartbeat cycles predetermined from the current moment. The heartbeat cycle can be measured based on the pulsation signal output from the pulsation detection device 70 that detects the heartbeat of the subject 18. The pulsation detection device 70 can be, for example, an electrocardiogram device. The pulsation signal can be a signal representing an electrocardiogram. The Doppler waveform average value can be defined as a value obtained by averaging the midpoint value (half the sum of the upper limit and the lower limit) of the blood flow velocity range with spectral component values ​​above a predetermined threshold value within a time range of N heartbeat cycles predetermined from the current moment. The image processing unit 34 sets the Doppler waveform average value as a reference value V0. In addition, the image processing unit 34 obtains the maximum value Vp and the minimum value Vn of the Doppler waveform line E(t) within the time range of N heartbeat cycles from the current moment. Alternatively, the image processing unit 34 may obtain the maximum value Vp, the minimum value Vn, and the Doppler waveform average value within a time range that is traced back by a predetermined time from the current time point.

[0073] The image processing unit 34 obtains the larger of the absolute value |Vp-V0| of the value obtained by subtracting the reference value V0 from the maximum value Vp and the absolute value |Vn-V0| of the value obtained by subtracting the reference value V0 from the minimum value Vn as the swing width SW. That is, the image processing unit 34 obtains the swing width SW according to SW=max(|Vp-V0|,|Vn-V0|). Here, "max" means the largest value among the values ​​listed in the parentheses immediately following it.

[0074] The image processing unit 34 multiplies the swing width SW by the predetermined scale factor k, thereby obtaining the display width Vs as Vs=k·SW. The image processing unit 34 associates the positive value +Vs of the display width with the upper limit Smax of the display range of the p-axis of the image coordinate system, and associates the negative value -Vs of the display width with the lower limit -Smax of the display range of the p-axis of the image coordinate system. Furthermore, the image processing unit 34 associates the value S0 at the center of the display range of the p-axis with the reference value V0.

[0075] The image processing unit 34 converts the value represented by the Doppler waveform into the coordinate value of the p-axis so that +Vs is displayed at the upper end of the display image, -Vs is displayed at the lower end of the display image, and the reference value V0 is displayed at the center of the vertical display range. The image processing unit 34 generates a video signal representing the Doppler waveform based on the Doppler waveform data obtained by converting the value represented by the Doppler waveform into the coordinate value of the p-axis, and outputs it to the display unit 42. The display unit 42 displays an image representing the Doppler waveform based on the video signal.

[0076] The scale factor k can be predetermined based on past diagnosis results, etc. The scale factor k can be read through the user interface. That is, the image processing unit 34 can obtain the scale factor k through the user interface and the control unit 22. When observing the vicinity of the mitral valve, the scale factor k can be, for example, greater than 1.1 and less than 1.8.

[0077] exist Figure 4 In the example shown, the swing amplitude SW=max(|Vp-V0|, |Vn-V0|) becomes SW=|Vn-V0|, the lower limit value of the p-axis corresponds to -Vs=-|Vn-V0|, and the upper limit value of the p-axis corresponds to +Vs=|Vn-V0|.

[0078] The image processing unit 34 performs a blood vessel determination to determine whether the observed part is an artery or a vein, and determines a scale factor k based on the determination result. In this embodiment, the image processing unit 34 sets the scale factor k=ka when determining that the observed part is an artery to be larger than the scale factor k=kv when determining that the observed part is a vein.

[0079] Generally, when observing veins, noise that is larger than the Doppler waveform appears in the image. Therefore, if the scale factor k is increased, the noise will be emphasized, and an image may be displayed in which it is difficult to grasp the general shape of the Doppler waveform or the direction of blood flow. On the other hand, the swing amplitude of the Doppler waveform when observing arteries is large, and the blood flow velocity represented by the Doppler waveform becomes sufficiently large relative to the noise. In addition, the shape of the Doppler waveform of the artery can usually be observed in detail, so by increasing the scale factor k, the detailed shape of the Doppler waveform can be more easily grasped on the image.

[0080] In the ultrasonic diagnostic apparatus 100 according to the present embodiment, the scale factor ka when determining that the observed part is an artery is greater than the scale factor kv when determining that the observed part is a vein. Therefore, when observing a vein, an image is displayed that makes it easy to understand the general shape of the Doppler waveform or the direction of blood flow, and when observing an artery, an image is displayed that makes it easy to understand the detailed shape of the Doppler waveform.

[0081] A specific example of blood vessel determination performed by the image processing unit 34 will be described. Blood vessel determination can be performed based on the polarity of the time differential value of the Doppler waveform line. Figure 5 The polarity of the Doppler waveform E(t) and its time differential value dE(t) / dt is shown in . The image processing unit 34 stores a pattern in which the polarity of the Doppler waveform differential value of each artery and vein changes over time. The polarity change pattern can be a binary number with a specified number of bits allocated to L cardiac cycles. Furthermore, the polarity change pattern can be a polarity change pattern corresponding to a time band from the initial moment of the systolic period of the 1st cycle to the last moment of the diastolic period of the Lth cycle. Here, L is an arbitrary positive integer. The polarity change pattern can also be a binary number as follows: when the polarity of the Doppler waveform differential value is positive, 1 (high) is established as a corresponding association, and when the polarity of the Doppler waveform differential value is negative, 0 (low) is established as a corresponding association.

[0082] The image processing unit 34 obtains the degree of similarity between the polarity change pattern of the Doppler waveform differential value and the polarity change pattern pre-stored for the artery. The degree of similarity may be, for example, a cross-correlation value. The image processing unit 34 determines that the observed part is an artery when the degree of similarity exceeds a predetermined threshold value Th1, and determines that the observed part is a vein when the degree of similarity is less than the threshold value Th1.

[0083] Furthermore, the image processing unit 34 may also obtain the degree of similarity between the polarity change pattern of the Doppler waveform differential value and the polarity change pattern pre-stored for veins. In this case, the image processing unit 34 determines that the observed part is a vein when the degree of similarity exceeds a predetermined threshold value Th2, and determines that the observed part is an artery when the degree of similarity is less than the threshold value Th2.

[0084] Blood vessel determination can be performed based on the evaluation area S(t) between the Doppler waveform line E(t) and the reference line representing the reference value V0. Figure 6 The upper part shows the Doppler waveform E(t), and the lower part shows the evaluation area S(t).

[0085] The image processing unit 34 acquires the evaluation area S(t) at a predetermined time interval and obtains a time waveform of the evaluation area S(t) corresponding to the L cardiac cycle. The image processing unit 34 stores the time waveform pattern of the evaluation area S(t) of each artery and vein. The time waveform pattern may be a time waveform pattern in which the predetermined L cardiac cycle is normalized on the time axis with a predetermined time length.

[0086] The image processing unit 34 normalizes the time waveform of the evaluation area S(t) on the time axis by a predetermined L heartbeat cycle, and obtains the degree of similarity between the normalized time waveform and a time waveform pattern stored in advance for the artery. The degree of similarity may be, for example, a cross-correlation value. The image processing unit 34 determines that the observed part is an artery when the degree of similarity exceeds a predetermined threshold value Th3, and determines that the observed part is a vein when the degree of similarity is less than the threshold value Th3.

[0087] Furthermore, the image processing unit 34 may obtain the degree of similarity between the time waveform of the evaluation area S(t) normalized on the time axis and the time waveform pattern stored for the vein. In this case, when the degree of similarity exceeds a predetermined threshold value Th4, the observed part is determined to be a vein, and when the degree of similarity is less than the threshold value Th4, the observed part is determined to be an artery.

[0088] Alternatively, the image processing unit 34 may perform blood vessel determination based on the time differential value dS(t) / dt, that is, the degree of approximation between the Doppler waveform line E(t) and the pre-stored time waveform pattern for the artery or vein, instead of evaluating the area S(t). Alternatively, the image processing unit 34 may perform blood vessel determination based on the second-order time differential value dS(t) / dt, that is, the degree of approximation between the Doppler waveform line E(t) and the pre-stored time waveform pattern for the artery or vein, instead of evaluating the area S(t). 2 S(t) / dt 2 Vessel determination is performed based on the approximation to a pre-stored temporal waveform pattern regarding an artery or a vein.

[0089] When the image processing unit 34 operates in the color Doppler mode, the blood vessel determination can be performed based on the deviation of the Doppler frequency of the phased received signal obtained by acquiring the transmission and reception beam multiple times (N times) in a certain direction (hereinafter referred to as the Doppler frequency deviation). When the blood flow velocity v(r) is calculated according to the above (Formula 1) to (Formula 3), the Doppler frequency deviation can be calculated based on the J-1 adjacent time Doppler frequencies calculated according to (Formula 4).

[0090] That is, the color Doppler processing unit 40 uses z(r, q)·z(r, q+1) added to the right side of (Formula 2) * The real part and the imaginary part of are used to calculate the adjacent time Doppler frequency fa(r, q) for each of q=1 to J-1 according to (Formula 4).

[0091] [Formula 4]

[0092]

[0093] The color Doppler processing unit 40 obtains the Doppler frequency deviation for J-1 adjacent time Doppler frequencies fa(r, 1), fa(r, 2), ... fa(r, J-1), and outputs it to the image processing unit 34. The Doppler frequency deviation may be a value indicating a deviation such as a dispersion or a standard deviation with respect to the J-1 adjacent time Doppler frequencies.

[0094] The image processing unit 34 determines that the observed part is an artery when the Doppler frequency deviation exceeds a predetermined threshold value Th5, and determines that the observed part is a vein when the Doppler frequency deviation is equal to or less than the threshold value Th5.

[0095] When operating in CW Doppler mode or color Doppler mode, if the folding phenomenon occurs, the image processing unit 34 can determine that the blood vessel is an artery. Here, the folding phenomenon in the CW Doppler mode refers to the Doppler waveform being periodically repeated in the vertical axis direction. The folding phenomenon in the color Doppler mode refers to the phenomenon that the polarity of the blood flow velocity v(r) represented by (Formula 3) changes discontinuously with time or area changes. For example, there is a phenomenon that the blood flow velocity v(r) increases in the negative direction over time and then changes sharply to a positive value. In addition, there is a phenomenon that the blood flow velocity v(r) increases in a certain direction of the area where the blood flow velocity v(r) is acquired and then changes sharply to a positive value. In the B-mode color Doppler image, the folding phenomenon is manifested as a phenomenon that the color changes sharply with time. In addition, when the area where the blood flows away from the ultrasonic probe 14 is marked with blue, and the area where the blood flows toward the ultrasonic probe 14 is marked with red, the folding phenomenon is manifested as a phenomenon that the corresponding area marked with red is marked with blue or the corresponding area marked with blue is marked with red.

[0096] When the folding phenomenon occurs, the control unit 22 can adjust the repetition frequency PRF in a manner that the folding phenomenon does not appear on the displayed image. When the scale factor k becomes larger, the control unit 22 can control the beam control unit 10, the transmitting unit 12, the receiving unit 20 and the information processing unit 26 to increase the repetition frequency PRF to a level that can avoid the folding phenomenon. In addition, when the scale factor k becomes smaller, the control unit 22 can control the beam control unit 10, the transmitting unit 12, the receiving unit 20 and the information processing unit 26 to reduce the repetition frequency PRF. By reducing the repetition frequency PRF, the display resolution in the vertical axis direction is improved.

[0097] The image processing unit 34 may determine the scale factor ka for the artery and the scale factor kv for the vein based on the area between the Doppler waveform line E(t) and the reference line indicating the reference value V0. The image processing unit 34 may, for example, calculate the time integral value of |EL(t)-V0| within a time range of N heartbeat cycles predetermined from the current moment or within a time range of only a predetermined time period predetermined from the current moment. As the time integral value decreases, the image processing unit 34 may increase the scale factor ka for the artery and the scale factor kv for the vein.

[0098] For arteries, the image processing unit 34 may determine the scale factor ka as follows: the ratio R of the area between the Doppler waveform E(t) times ka and the reference line in the displayed image becomes greater than a certain threshold value Ta1 and less than a certain threshold value Ta2 (Ta1≤R≤Ta2). For veins, the scale factor kv may be determined as follows: the ratio R of the area between the Doppler waveform E(t) times kv and the reference line in the displayed image becomes greater than a certain threshold value Tv1 and less than a certain threshold value Tv2 (Tv1≤R≤Tv2). Here, the threshold value Ta1 is a value greater than the threshold value Tv2.

[0099] The following describes the case where a site other than the vicinity of the mitral valve is observed. Figure 7 The left side of FIG shows an example of a B-mode color Doppler image acquired near the abdominal aorta. Figure 7 The right side of FIG shows a Doppler waveform obtained near the abdominal aorta. Figure 8 The Doppler waveform line E(t) is shown together with the Doppler waveform. In the vicinity of the abdominal aorta, unlike in the vicinity of the mitral valve of the heart, the blood flow direction is unidirectional. Figure 8 In the example shown, the reference value V0 is located on the positive side of the base line 52, and the swing width SW is SW=max(|Vp-V0|,|Vn-V0|)=Vp-V0. The image processing unit 34 multiplies the swing width SW by the scale factor k, thereby obtaining the display width Vs as Vs=k·SW.

[0100] Regarding the abdominal aorta, the threshold values ​​in the blood vessel determination are set so that the image processing unit 34 determines that the observed part is an artery. When observing the vicinity of the abdominal aorta, the scale factor k may be, for example, 1.8 or more and less than 3.2.

[0101] exist Fig. 9 The left side of FIG shows an example of a B-mode color Doppler image acquired near the portal vein of the liver. Fig. 9 The right side of the figure shows the Doppler waveform acquired near the portal vein. Fig.10 In FIG. 1 , the Doppler waveform line E(t) is shown together with the Doppler waveform. In the vicinity of the portal vein, unlike in the vicinity of the mitral valve of the heart, the direction of blood flow is unidirectional. Fig.10 In the example shown, the reference value V0 is located on the negative side of the base line 52, and the swing width SW is SW=max(|Vp-V0|,|Vn-V0|)=V0-Vn. The image processing unit 34 multiplies the swing width SW by the scale factor k, thereby obtaining the display width Vs as Vs=k·SW.

[0102] Regarding the portal vein, the threshold values ​​in the blood vessel determination may be set so that the image processing unit 34 determines that the observed portion is an artery, and the threshold values ​​in the blood vessel determination may be set so that the image processing unit 34 determines that the observed portion is a vein. When observing the vicinity of the portal vein, the scale factor k may be, for example, greater than or equal to 2.4 and less than 9.0.

[0103] In the above, an implementation method of using the reference value V0 as the average value of the Doppler waveform is shown. The reference value V0 can be 0 or the center of gravity of the Doppler waveform. For example, the center of gravity of the Doppler waveform is defined as the following value: for example, the component values ​​of the spectrum are used as weighted values, and the weighted average value of the blood flow velocity is calculated for each time, and then the weighted average value of the blood flow velocity is averaged within a time range of N heart cycles predetermined from the current moment. In addition, the center of gravity of the Doppler waveform can also be defined as the following value: the value obtained by averaging the weighted average value of the blood flow velocity within a time range of only a predetermined time from the current moment.

[0104] The image processing unit 34 may perform blood vessel determination and update the scale factor k at a timing corresponding to the pulsation of the subject 18. For example, the image processing unit 34 may set M to a positive integer, perform blood vessel determination every M heartbeat cycles, and update the scale factor k. Fig.11 FIG. 6 conceptually shows a Doppler waveform 60 and an update time 58 of the scale factor k when the blood vessel determination is performed every M heartbeat cycles and the scale factor k is further updated. In addition, the image processing unit 34 may use T as an update cycle, and perform blood vessel determination and update the scale factor k every update cycle T. Fig.122 conceptually shows a Doppler waveform 60 and an update time 58 of the scale factor k when blood vessel determination is performed at each update cycle T and the scale factor k is updated.

[0105] Furthermore, when an operation for updating the scale factor k is performed on the operation unit 24 , the image processing unit 34 may execute blood vessel determination and update the scale factor k.

[0106] The image processing unit 34 can automatically perform blood vessel determination and set the scale factor k according to the diagnostic condition. The diagnostic condition is determined, for example, based on the observation site such as the heart, liver, abdomen, and the lesions that may be found in each observation site. The diagnostic condition can be identified by the image processing unit 34 through the user interface.

[0107] Furthermore, the image processing unit 34 may sequentially obtain the swing width SW=max(|Vp-V0|, |Vn-V0|) within a time range of N heartbeat cycles predetermined from the current moment or within a time range of only a predetermined time period predetermined from the current moment. When the swing width obtained later changes relative to the swing width SW obtained previously and exceeds a predetermined threshold value ThSW, the image processing unit 34 may automatically perform blood vessel determination and set a proportionality factor k.

[0108] [Structure of the present invention]

[0109] Structure 1:

[0110] An ultrasonic diagnostic device, characterized in that it comprises: a transmitting unit, which transmits ultrasonic waves to a subject through an ultrasonic probe; a receiving unit, which receives the ultrasonic waves reflected in the subject through the ultrasonic probe; and an information processing unit, which processes a received signal output from the receiving unit, wherein the information processing unit performs the following processing: generates Doppler waveform data based on the received signal; determines whether the observed part is an artery or a vein based on the Doppler waveform data; and determines the display range of the blood flow velocity represented by the Doppler waveform based on the determination result.

[0111] Structure 2:

[0112] An ultrasonic diagnostic device, characterized in that it comprises: a transmitting unit, which transmits ultrasonic waves to a subject through an ultrasonic probe; a receiving unit, which receives the ultrasonic waves reflected in the subject through the ultrasonic probe; and an information processing unit, which processes a received signal output from the receiving unit, wherein the information processing unit performs the following processing: generates Doppler waveform data based on the received signal; determines whether the observed part is an artery or a vein based on the deviation of the Doppler frequencies of the multiple received signals obtained based on multiple ultrasonic transmissions and receptions; and determines the display range of the blood flow velocity represented by the Doppler waveform based on the determination result.

[0113] Structure 3:

[0114] An ultrasonic diagnostic device, characterized in that it comprises: a transmitting unit, which transmits ultrasonic waves to a subject through an ultrasonic probe; a receiving unit, which receives the ultrasonic waves reflected in the subject through the ultrasonic probe; and an information processing unit, which processes a received signal output from the receiving unit, wherein the information processing unit performs the following processing: generates Doppler waveform data and color Doppler data based on the received signal; determines whether the observed part is an artery or a vein based on the color Doppler data; and determines the display range of the blood flow velocity represented by the Doppler waveform based on the determination result.

[0115] Structure 4:

[0116] According to the ultrasonic diagnostic apparatus of configuration 3, the information processing unit determines whether the observation site is an artery or a vein based on whether a folding phenomenon occurs in the color Doppler data.

[0117] Structure 5:

[0118] The ultrasonic diagnostic apparatus according to any one of Configurations 1 to 4, wherein the information processing unit determines a scale factor when displaying the Doppler waveform based on the determination result.

[0119] Structure 6:

[0120] The ultrasonic diagnostic device according to structure 5 is characterized in that the information processing unit performs the following processing: a baseline value of the Doppler waveform line obtained from the Doppler waveform data is obtained, and in addition to the judgment result, the proportional factor is determined based on the area of ​​the area between the Doppler waveform line obtained from the Doppler waveform data and the baseline represented by the baseline value.

[0121] Structure 7:

[0122] The ultrasonic diagnostic device according to structure 5 is characterized in that the information processing unit performs the following processing: obtaining the maximum value, minimum value and reference value of the Doppler waveform line obtained from the Doppler waveform data, and in addition to the judgment result, determining the proportional factor based on the maximum value, the minimum value and the reference value.

[0123] Structure 8:

[0124] The ultrasonic diagnostic apparatus according to Configuration 1 is characterized in that the information processing unit determines whether the observation site is an artery or a vein based on a time differential value of a Doppler waveform line obtained from the Doppler waveform data.

[0125] Structure 9:

[0126] The ultrasonic diagnostic apparatus according to Configuration 1 is characterized in that the information processing unit determines whether the observation site is an artery or a vein based on a time-integrated value of a Doppler waveform line obtained from the Doppler waveform data.

[0127] Structure 10

[0128] According to the ultrasonic diagnostic apparatus of configuration 1, the information processing unit determines whether the observation site is an artery or a vein based on whether a folding phenomenon occurs in the Doppler waveform data.

[0129] Structure 11:

[0130] The ultrasonic diagnostic apparatus according to any one of Configurations 1 to 10 is characterized by comprising: a pulsation detection device that detects the pulsation of the subject, and the information processing unit determines whether the observation site is an artery or a vein at a time corresponding to the pulsation of the subject.

[0131] Structure 12:

[0132] The ultrasonic diagnostic apparatus according to any one of Configurations 1 to 11 is characterized in that a repetition frequency when the transmitting unit transmits the ultrasonic wave is set according to the display range.

Claims

1. An ultrasonic diagnostic device, characterized in that: have: A transmitting unit, which transmits ultrasonic waves to the subject through an ultrasonic probe; a receiving unit that receives the ultrasonic wave reflected by the subject through the ultrasonic probe; and an information processing unit that processes the reception signal output from the reception unit, The information processing unit performs the following processing: generating Doppler waveform data according to the received signal; Determining whether the observed part is an artery or a vein according to the Doppler waveform data; and The display range of the blood flow velocity represented by the Doppler waveform is determined based on the determination result.

2. An ultrasonic diagnostic device, characterized in that: have: A transmitting unit, which transmits ultrasonic waves to the subject through an ultrasonic probe; a receiving unit that receives the ultrasonic wave reflected by the subject through the ultrasonic probe; and an information processing unit that processes the reception signal output from the reception unit, The information processing unit performs the following processing: generating Doppler waveform data according to the received signal; Determining whether the observed part is an artery or a vein based on the degree of deviation of the Doppler frequencies of the plurality of received signals obtained based on the plurality of ultrasonic transmission and reception; and The display range of the blood flow velocity represented by the Doppler waveform is determined based on the determination result.

3. An ultrasonic diagnostic device, characterized in that: have: A transmitting unit, which transmits ultrasonic waves to the subject through an ultrasonic probe; a receiving unit that receives the ultrasonic wave reflected by the subject through the ultrasonic probe; and an information processing unit that processes the reception signal output from the reception unit, The information processing unit performs the following processing: generating Doppler waveform data and color Doppler data according to the received signal; Determining whether the observed part is an artery or a vein according to the color Doppler data; and The display range of the blood flow velocity represented by the Doppler waveform is determined based on the determination result.

4. The ultrasonic diagnostic apparatus according to claim 3, wherein: The information processing unit determines whether the observation site is an artery or a vein based on whether a folding phenomenon occurs in the color Doppler data.

5. The ultrasonic diagnostic apparatus according to any one of claims 1 to 4, characterized in that: The information processing unit determines a scale factor when displaying the Doppler waveform based on the determination result.

6. The ultrasonic diagnostic apparatus according to claim 5, characterized in that: The information processing unit performs the following processing: The scale factor is determined based on the Doppler waveform obtained from the Doppler waveform data in addition to the determination result.

7. The ultrasonic diagnostic apparatus according to claim 6, wherein: The information processing unit performs the following processing: obtaining a reference value of a Doppler waveform line obtained from the Doppler waveform data, The proportionality factor is determined based on an area of ​​a region between a Doppler waveform line obtained from the Doppler waveform data and a reference line indicated by the reference value in addition to the determination result.

8. The ultrasonic diagnostic apparatus according to claim 6, wherein: The information processing unit performs the following processing: Finding the maximum value, minimum value and reference value of the Doppler waveform line obtained from the Doppler waveform data, The scale factor is determined based on the maximum value, the minimum value, and the reference value in addition to the determination result.

9. The ultrasonic diagnostic apparatus according to claim 1, wherein: The information processing unit determines whether the observation site is an artery or a vein based on a time differential value of a Doppler waveform obtained from the Doppler waveform data.

10. The ultrasonic diagnostic apparatus according to claim 1, wherein: The information processing unit determines whether the observation site is an artery or a vein based on a time-integrated value of a Doppler waveform line obtained from the Doppler waveform data.

11. The ultrasonic diagnostic apparatus according to claim 1, wherein: The information processing unit determines whether the observation site is an artery or a vein based on whether a folding phenomenon occurs in the Doppler waveform data.

12. The ultrasonic diagnostic apparatus according to any one of claims 1 to 4, characterized in that: have: a pulsation detection device for detecting the pulsation of the subject, The information processing unit determines whether the observation site is an artery or a vein at a timing corresponding to the pulsation of the subject.

13. The ultrasonic diagnostic apparatus according to any one of claims 1 to 4, characterized in that: The repetition frequency at which the transmitting unit transmits the ultrasonic wave is set according to the display range.

Images