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 from the received signal, obtains a maximum value, a minimum value, and a reference value of a Doppler waveform line obtained from the Doppler waveform data, and determines a display range of the blood flow velocity indicated by the Doppler waveform on the basis of the maximum value, the minimum value, and the reference value.

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 apparatus of the present invention is characterized in that it comprises: a transmitting unit that transmits ultrasonic waves to a subject through an ultrasonic probe; a receiving unit that receives the ultrasonic waves reflected in the subject through the ultrasonic probe; and an information processing unit that processes a reception signal output from the receiving unit, wherein the information processing unit performs the following processing: generates Doppler waveform data based on the reception signal; obtains a maximum value, a minimum value, and a reference value of a Doppler waveform line obtained from the Doppler waveform data; and

[0011] The display range of the blood flow velocity represented by the Doppler waveform is determined based on the maximum value, the minimum value, and the reference value.

[0012] Preferably, the reference value is a Doppler waveform average value, 0, or a center of gravity.

[0013] Preferably, the information processing unit determines the display range by multiplying a predetermined scaling factor by a larger one of an absolute value of a value obtained by subtracting the reference value from the maximum value and an absolute value of a value obtained by subtracting the reference value from the minimum value.

[0014] Preferably, the scaling factor is determined based on an index value obtained by dividing an absolute value of a value obtained by subtracting the minimum value from the maximum value by a larger absolute value of the maximum value and an absolute value of the minimum value.

[0015] Preferably, the information processing unit calculates the proportional factor based on the value of a proportional function, the proportional function obtains the proportional factor by assigning an index value, and represents a curve passing through multiple set points or a curve that is approximate to a curve passing through multiple set points, the index value represents the difference between the maximum value and the minimum value, and the set point is a point on a coordinate plane that corresponds to the index value and the proportional factor.

[0016] Preferably, the information processing unit sets the set point through a user interface.

[0017] Preferably, the information processing unit determines the scaling factor according to a diagnosis condition.

[0018] Preferably, the information processing unit obtains the scale factor through a user interface.

[0019] Preferably, the information processing unit acquires a signal indicating the pulsation of the subject from a pulsation detection device that detects the pulsation of the subject, and determines the display range at a timing corresponding to the pulsation of the subject.

[0020] Preferably, a repetition frequency at which the transmitting unit transmits the ultrasonic wave is set according to the display range.

[0021] Preferably, the information processing unit determines the display range based on an area of ​​a region between the Doppler waveform line and a reference line indicated by the reference value.

[0022] Effects of the Invention

[0023] According to the present invention, it is possible to set the display state of the ultrasonic diagnostic apparatus 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 is a diagram showing an example of a scaling function.

[0029] Figure 6 It is a diagram showing an example of a B-mode color Doppler image and a Doppler waveform.

[0030] Figure 7 It is a diagram showing the Doppler waveform line together with the Doppler waveform.

[0031] Figure 8 It is a diagram showing an example of a B-mode color Doppler image and a Doppler waveform.

[0032] Fig. 9 It is a diagram showing the Doppler waveform line together with the Doppler waveform.

[0033] Fig.10 It is a diagram showing the update timing of the scale factor.

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

[0035] Explanation of symbols

[0036] 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

[0037] 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 .

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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 being in 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 over 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 over the subject 18.

[0043] Beam.

[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 operation in the color Doppler mode is described. 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 transmission and reception beam. The color Doppler processing unit 40 generates color Doppler data based on the phased reception signal obtained by acquiring j times in each direction of the transmission and reception 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 transmission and reception 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 j types of phased received 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] exist Figure 4 The Doppler waveform for illustrating scaling is shown in FIG. 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 Doppler waveform is determined to be above -Vs and below Vs.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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|.

[0067] As shown in the following (Formula 1), the scaling factor k can also be determined based on an nth-order polynomial as a scaling function.

[0068] (Formula 1) k = α(n)x n +α(n-1)x n-1 +……

[0069] +α(1)x+α(0)

[0070] Here, the index value x is a value indicating the difference between the maximum value Vp and the minimum value Vn, and is defined by the following formula (Formula 2).

[0071] (Formula 2)x=|Vp-Vn| / max(|Vp|, ​​|Vn|)

[0072] The n+1 coefficients α(0) to α(n) are obtained as follows. First, in the xk coordinate plane with the vertical axis as k and the horizontal axis as x, the user sets n+1 set points. Then, the coefficients α(0) to α(n) are obtained so that the curve represented by the proportional function becomes a curve passing through the n+1 set points or approximates a curve passing through the n+1 set points. The coefficients α(0) to α(n) can be obtained by the least squares method or the spline interpolation method. The setting of the set points by the user can be performed via a user interface composed of the operating unit 24 and the display unit 42.

[0073] exist Figure 5 An example of a proportional function is shown in . This proportional function is obtained by the user specifying 6 set points on the xk coordinate plane and finding the coefficients of the fifth-order polynomial that complements these 6 set points. Specifically, n = 5, α(0) = 9, α(1) = -20.936, α(2) = 17.829, α(3) = -2.7052, α(4) = -2.897, α(5) = 0.9594, Figure 5 The proportional function shown is expressed as (Formula 3).

[0074] (Formula 3)k=0.9594x 5 -2.897x 4

[0075] -2.7052x 3 +17.829x 2 -20.936x+9

[0076] The waveform characteristic values ​​of the Doppler waveform, such as the maximum value, the minimum value, and the average value of the Doppler waveform, vary depending on the observation site. Therefore, if the Doppler waveform is displayed at a constant scale, it may be difficult to observe the Doppler waveform. According to the process of obtaining the scale factor k based on the scale function, the scale factor k is obtained by assigning the index value x based on the maximum value Vp of the Doppler waveform line E(t) and the minimum value Vn of the Doppler waveform line E(t) to the scale function. Thus, even if the maximum value Vp of the Doppler waveform line E(t) and the minimum value Vn of the Doppler waveform line E(t) change according to the change of the observation site, an appropriate scale factor k can be obtained.

[0077] Thus, as shown in (Formula 2), the information processing unit 26 obtains the index value x by dividing the absolute value of the value obtained by subtracting the minimum value Vn of the Doppler waveform E(t) from the maximum value Vp of the Doppler waveform E(t) by the larger absolute value of the maximum value Vp and the absolute value of the minimum value Vn. The information processing unit 26 also determines the scale factor k by assigning the index value x to the scale function shown in (Formula 1).

[0078] The information processing unit 26 determines the display range by multiplying the larger of the absolute value of the value obtained by subtracting the reference value V0 from the maximum value Vp of the Doppler waveform line E(t) and the absolute value of the value obtained by subtracting the reference value V0 from the minimum value Vn of the Doppler waveform line E(t) by the scale factor k. That is, the information processing unit 26 obtains the swing width SW according to SW=max(|Vp-V0|,|Vn-V0|), and determines the range of -k·SW or more and k·SW or less as the display range of the Doppler waveform.

[0079] exist Figure 6 The left side of FIG shows an example of a B-mode color Doppler image acquired near the abdominal aorta. Figure 6 The right side of FIG shows a Doppler waveform obtained near the abdominal aorta. Figure 7 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 7 In the example shown, the reference value V0 is located on the positive side of the baseline 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. When observing the vicinity of the abdominal aorta, the scale factor k can be, for example, 1.8 or more and less than 3.2.

[0080] exist Figure 8 The left side of FIG shows an example of a B-mode color Doppler image acquired near the portal vein of the liver. Figure 8 The right side of the figure shows the Doppler waveform acquired near the portal vein. Fig. 9 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. 9 In the example shown, the reference value V0 is located on the negative side of the baseline 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. When observing the vicinity of the portal vein, the scale factor k may be, for example, greater than 2.4 and less than 9.0.

[0081] The image processing unit 34 may determine the scale factor k 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 |Ft(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. The image processing unit 34 may increase the scale factor k as the time integral value decreases. The image processing unit 34 may determine the scale factor k as follows: the ratio R of the area between the k-times Doppler waveform line E(t) and the reference line in the displayed image becomes greater than a certain threshold value Th1 and less than a certain threshold value Th2 (Th1≤R≤Th2).

[0082] 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.

[0083] The image processing unit 34 may 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 and update the scale factor k every M heartbeat cycles. Fig.10 FIG. 6 conceptually shows a Doppler waveform 60 and an update time 58 of the scale factor k when the scale factor k is updated every M heartbeat cycles. In addition, the image processing unit 34 may set T as an update cycle and update the scale factor k every update cycle T. Fig.11 2 conceptually shows a Doppler waveform 60 and an update time 58 of the scale factor k when the scale factor k is updated at each update period.

[0084] Furthermore, when an operation for updating the scale factor k is performed on the operation unit 24 , the image processing unit 34 may update the scale factor k.

[0085] The image processing unit 34 may automatically set the scale factor k according to the diagnosis condition. The diagnosis condition may be determined, for example, according to the observation site such as the heart, liver, abdomen, etc. and the lesions that may be found in each observation site. The diagnosis condition may be identified by the image processing unit 34 through the user interface.

[0086] When the Doppler mode is the PW Doppler mode, the control unit 22 can adjust the repetition frequency PRF so that the folding phenomenon does not appear on the displayed image. Here, the folding phenomenon refers to the Doppler waveform being periodically repeated and displayed in the longitudinal direction. 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. And, 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 longitudinal direction is improved.

[0087] [Structure of the present invention]

[0088] Structure 1:

[0089] An ultrasonic diagnostic device, characterized in that it comprises: a transmitting unit that transmits ultrasonic waves to a subject through an ultrasonic probe; a receiving unit that receives the ultrasonic waves reflected in the subject through the ultrasonic probe; and an information processing unit that processes a reception signal output from the receiving unit, wherein the information processing unit performs the following processing: generates Doppler waveform data based on the reception signal; obtains a maximum value, a minimum value, and a reference value of a Doppler waveform line obtained from the Doppler waveform data; and

[0090] The display range of the blood flow velocity represented by the Doppler waveform is determined based on the maximum value, the minimum value, and the reference value.

[0091] Structure 2:

[0092] The ultrasonic diagnostic apparatus according to Configuration 1 is characterized in that the reference value is a Doppler waveform average value, 0, or a centroid.

[0093] Structure 3:

[0094] The ultrasonic diagnostic device according to Structure 1 or Structure 2 is characterized in that the information processing unit determines the display range by multiplying a predetermined scaling factor by the larger of the absolute value of the value obtained by subtracting the baseline value from the maximum value and the absolute value of the value obtained by subtracting the baseline value from the minimum value.

[0095] Structure 4:

[0096] The ultrasonic diagnostic apparatus according to Configuration 3 is characterized in that the scale factor is determined based on an index value obtained by dividing an absolute value of a value obtained by subtracting the minimum value from the maximum value by a larger absolute value of the maximum value and an absolute value of the minimum value.

[0097] Structure 5:

[0098] The ultrasonic diagnostic device according to structure 3 is characterized in that the information processing unit calculates the proportional factor based on the value of the proportional function, the proportional function obtains the proportional factor by assigning an index value, and represents a curve passing through multiple set points or a curve that is approximate to the curve passing through multiple set points; the index value is a value representing the difference between the maximum value and the minimum value; the set point is a point on the coordinate plane that establishes a corresponding association between the index value and the proportional factor.

[0099] Structure 6

[0100] The ultrasonic diagnostic apparatus according to Configuration 5 is characterized in that the information processing unit sets the set point through a user interface.

[0101] Structure 7:

[0102] The ultrasonic diagnostic apparatus according to Configuration 3 is characterized in that the information processing unit determines the scale factor according to a diagnosis condition.

[0103] Structure 8:

[0104] The ultrasonic diagnostic apparatus according to Structure 3 is characterized in that the information processing unit obtains the scale factor through a user interface.

[0105] Structure 9:

[0106] The ultrasonic diagnostic device according to any one of Structures 1 to 8 is characterized in that the information processing unit performs the following processing: obtaining a signal representing the pulsation of the subject from a pulsation detection device that detects the pulsation of the subject, and determining the display range at a time corresponding to the pulsation of the subject.

[0107] Structure 10:

[0108] The ultrasonic diagnostic apparatus according to any one of Configurations 1 to 9 is characterized in that a repetition frequency when the transmitting unit transmits the ultrasonic wave is set according to the display range.

[0109] Structure 11:

[0110] The ultrasonic diagnostic apparatus according to any one of Configurations 1 to 10 is characterized in that the information processing unit determines the display range based on an area of ​​a region between the Doppler waveform line and a reference line indicated by the reference value.

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; deriving a maximum value, a minimum value, and a reference value of a Doppler waveform line obtained from the Doppler waveform data; and The display range of the blood flow velocity represented by the Doppler waveform is determined based on the maximum value, the minimum value, and the reference value.

2. The ultrasonic diagnostic apparatus according to claim 1, wherein: The reference value is the Doppler waveform average value, 0 or the center of gravity.

3. The ultrasonic diagnostic apparatus according to claim 1, wherein: The information processing unit determines the display range by multiplying a predetermined scale factor by a larger one of an absolute value of a value obtained by subtracting the reference value from the maximum value and an absolute value of a value obtained by subtracting the reference value from the minimum value.

4. The ultrasonic diagnostic apparatus according to claim 3, wherein: The scaling factor is determined based on an index value obtained by dividing an absolute value of a value obtained by subtracting the minimum value from the maximum value by a larger absolute value of the maximum value and an absolute value of the minimum value.

5. The ultrasonic diagnostic apparatus according to claim 3, wherein: The information processing unit calculates the proportional factor based on a value of a proportional function, wherein the proportional function obtains the proportional factor by assigning an index value and represents a curve passing through a plurality of set points or a curve that approximates the curve passing through the plurality of set points. The index value is a value indicating the difference between the maximum value and the minimum value, The set point is a point on a coordinate plane that establishes a corresponding association between the index value and the proportional factor.

6. The ultrasonic diagnostic apparatus according to claim 5, characterized in that: The information processing unit sets the set point through a user interface.

7. The ultrasonic diagnostic apparatus according to claim 3, characterized in that: The information processing unit determines the scaling factor according to a diagnosis condition.

8. The ultrasonic diagnostic apparatus according to claim 3, wherein: The information processing unit obtains the scale factor through a user interface.

9. The ultrasonic diagnostic apparatus according to any one of claims 1 to 8, characterized in that: The information processing unit performs the following processing: acquiring a signal representing the pulsation of the subject from a pulsation detection device that detects the pulsation of the subject, And the display range is determined at a timing corresponding to the pulsation of the subject.

10. The ultrasonic diagnostic apparatus according to any one of claims 1 to 8, characterized in that: The repetition frequency at which the transmitting unit transmits the ultrasonic wave is set according to the display range.

11. The ultrasonic diagnostic apparatus according to any one of claims 1 to 8, characterized in that: The information processing unit determines the display range based on an area of ​​a region between the Doppler waveform line and a reference line indicated by the reference value.

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