JP4679141B2 - Ultrasonic diagnostic apparatus and method for displaying ultrasonic diagnostic image - Google Patents

Description

  The present invention relates to an ultrasonic diagnostic apparatus and an ultrasonic diagnostic image display method capable of displaying waveform data representing temporal changes such as D mode and M mode.

  The ultrasonic diagnostic apparatus radiates an ultrasonic pulse generated from a piezoelectric vibrator built in an ultrasonic probe into a subject, and generates an ultrasonic reflected wave generated by a difference in acoustic impedance of the subject tissue by the piezoelectric vibrator. It is received and displayed on the monitor. This diagnostic method is widely used for functional diagnosis and morphological diagnosis of various organs of a living body because a real-time two-dimensional image can be easily observed with a simple operation by simply bringing an ultrasonic probe into contact with the body surface. Ultrasound diagnostic methods for obtaining biological information from reflected waves from tissues or blood cells in a living body have made rapid progress with the development of two major technologies, the ultrasonic pulse reflection method and the ultrasonic Doppler method. The obtained B-mode image, M-mode image, and color Doppler image are indispensable in today's ultrasonic image diagnosis.

  On the other hand, there is a Doppler spectrum method as a method for quantitatively and accurately obtaining a blood flow velocity at an arbitrary position of a subject. In this Doppler spectrum method, ultrasonic transmission / reception is performed a plurality of times on the same part of the subject at regular intervals, and the ultrasonic reflected wave reflected by a moving reflector such as a blood cell is used for ultrasonic transmission / reception. Quadrature detection is performed using a reference signal having a frequency substantially equal to the resonance frequency of the piezoelectric vibrator to detect a Doppler signal. Then, a Doppler signal at a desired portion is extracted from the Doppler signal by using a range gate, and Doppler spectrum data is generated by performing FFT (Fast Fourier transform) analysis on the extracted Doppler signal.

  According to such a procedure, Doppler spectrum data is continuously generated for Doppler signals obtained from a desired part of the subject, and a plurality of generated Doppler spectrum data are sequentially arranged, so-called Doppler spectrum image data ( D mode image) is generated. In general, in order to accurately set the range gate at a desired observation site in the subject, the range gate is set under B-mode image observation, and the position of the range gate is displayed on the B-mode image. .

  The Doppler spectrum data obtained by this ultrasonic Doppler diagnostic device is generally generated with frequency (f) on the vertical axis, time (t) on the horizontal axis, and the power (intensity) of each frequency component as luminance (gradation). Based on the Doppler spectrum data, various diagnostic parameters are measured.

  That is, in this measurement method, first, for each Doppler spectrum data obtained continuously in time, the maximum flow velocity Vp corresponding to the maximum frequency fp of the Doppler frequency component distributed in the frequency axis direction, or the average The position of the average flow velocity Vc corresponding to the frequency fc is set, and a trace waveform indicating the time change of the position of the maximum flow velocity Vp and the average flow velocity Vc is generated. Next, in this trace waveform, a waveform peak PS (Peak of Systolic) occurring in the systole and a waveform peak ED (End of Diastolic) occurring in the diastole are detected for each of the heartbeat intervals. Based on the position information of the PS or ED, the HR (Heart Rate) of the blood flow in the blood vessel is measured. Further, from the trace waveform in the heart beat section set by the PS or ED, the peripheral blood vessel is measured. Measures diagnostic parameters such as PI (Pulsatility Index) and RI (Resistance Index).

  The above-described generation of trace waveforms of Vp and Vc, detection of PS / ED, and measurement of diagnostic parameters such as PI and RI have conventionally been based on manual operations for frozen Doppler spectrum images. In recent years, automatic tracing of Vp and Vc and automatic measurement of HR, PI, or RI for a Doppler spectrum image displayed in real time has become possible (see, for example, Patent Document 1).

Furthermore, in each processing such as generation of trace waveforms of Vp and Vc, detection of PS / ED, automatic measurement of diagnostic parameters such as PI and RI, malfunctions caused by the effects of sensitivity, diagnostic part, noise, etc. As a technique for avoiding the display of measurement values, an ultrasonic diagnostic apparatus has been devised in which parameters used for each process can be changed (see, for example, Patent Document 2).

  In this ultrasonic diagnostic apparatus, a technique for generating a trigger synchronized with a trace waveform of Vp or Vc or an electrocardiographic waveform and detecting PS / ED using the generated synchronous trigger has been devised.

In addition, as a related technique, an ultrasonic diagnostic apparatus has been devised in which a display timing can be set in accordance with a time phase of an organ such as a heart when a sweep image such as an M-mode image or a spectrum Doppler image is displayed. (For example, see Patent Document 3).
US Pat. No. 5,628,321 JP 2003-284718 A JP 2003-52692 A

  However, in the conventional technique, when displaying a spectrum image of a pulsating blood flow such as a heart or a carotid artery, the sweep speed that determines the time axis scale of the horizontal axis is set to 1, 2, 4, 6, 8 seconds, for example. It can only be set discretely as in the case. On the other hand, since the heart rate may vary depending on the subject, it is difficult to display the spectrum of the extra time phase other than the waveform of several heartbeats necessary for measurement, and the heartbeat waveform may be interrupted in the middle There is also. That is, with the conventional technology, it is difficult to appropriately display waveform (spectrum) data corresponding to the required heart rate without excess or deficiency.

  As a result, the user needs to perform a complicated operation of finding an optimal spectrum location (time phase) each time Doppler measurement is performed and setting a measurement range of a plurality of consecutive heartbeats. For example, to obtain the area to be used for measurement, change the sweep speed and re-acquire the spectrum data or search for the optimum place with cine, and the place where the time cursor is necessary (up to 1 heartbeat in the display frame where the spectrum image is displayed) It is necessary to confirm that the waveform of the desired heart rate is entered.

  For this reason, the user finds the optimal spectrum location (time phase), and does not involve complicated operations such as setting the measurement range of multiple heartbeats. Development of a technique for appropriately displaying a Doppler spectrum image in a range that can be displayed without any problem is desired. The development of such a technique is equally important when displaying waveform data representing time changes such as an M-mode image as well as a Doppler spectrum image (D-mode image).

  The present invention has been made to cope with such a conventional situation, and when displaying waveform data representing a time change such as D mode or M mode, the waveform data in a desired range is easily and appropriately displayed. An object of the present invention is to provide an ultrasonic diagnostic apparatus and a method for displaying an ultrasonic diagnostic image.

In order to achieve the above object, an ultrasonic diagnostic apparatus according to the present invention includes a heartbeat cycle calculating means for calculating a heartbeat cycle by heartbeat synchronization and waveform data for generating Doppler signal data as described in claim 1. Generating means; Doppler spectrum generating means for obtaining a Doppler spectrum based on the Doppler signal data; storage means for storing the Doppler spectrum; time phase detecting means for detecting a time phase of a feature point based on the Doppler spectrum; , A time axis scale setting means for setting a time axis scale corresponding to a desired heart rate based on the heartbeat cycle, and the time axis scale and the time phase of the feature points stored in the storage means based on the time axis scale Read means for reading at least a part of the Doppler spectrum as a display Doppler spectrum, and the display Doppler spectrum. Display means for displaying a tram, it is characterized in that it has a.

According to another aspect of the present invention, there is provided a method for displaying an ultrasonic diagnostic image, wherein, in order to achieve the above-described object, as described in claim 7, a step of calculating a heartbeat period by heartbeat synchronization and generating Doppler signal data Obtaining a Doppler spectrum based on the Doppler signal data; storing the Doppler spectrum; detecting a time point of a feature point based on the Doppler spectrum; Setting a time axis scale corresponding to a desired heart rate ; and reading at least a part of the stored Doppler spectrum as a display Doppler spectrum based on the time axis scale and the time phase of the feature points; , that it has the steps of: displaying on the display means the display Doppler spectrum It is an butterfly.

In the display method of an ultrasound diagnostic apparatus and an ultrasonic diagnostic image according to the present invention, when displaying the waveform data representing the time between changes, by setting the cut-out position of the time axis scale and waveform data, the heartbeat waveform Waveform data in a desired range necessary for measurement can be displayed easily and appropriately without being interrupted .

  Embodiments of an ultrasonic diagnostic apparatus and an ultrasonic diagnostic image display method according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a configuration diagram showing an embodiment of an ultrasonic diagnostic apparatus according to the present invention, and FIG. 2 is a detailed configuration of a DSP 31, a PS / ED detection unit 32, and a measurement unit 33 in the ultrasonic diagnostic apparatus shown in FIG. FIG.

  This ultrasonic diagnostic apparatus displays a B mode for displaying an ultrasonic tomographic image (B mode tomographic image), an M mode for displaying a temporal position change of a reflection source in the ultrasonic beam direction as a motion curve, and blood flow information. Doppler mode (pulse Doppler (PW) / continuous wave Doppler (CW)), CFM (color flow mapping) mode for displaying blood flow information two-dimensionally, MC mode in which color images in CFM mode are superimposed on M mode, etc. It can operate according to various known modes.

  The ultrasonic diagnostic apparatus is an electronic scan having a plurality of piezoelectric vibrators that transmit ultrasonic waves to a diagnostic site including the blood flow BL in the subject PS, convert the ultrasonic echoes into corresponding voltage signals, and receive them. A type ultrasonic probe 1 and an apparatus main body 2 connected to the ultrasonic probe 1 are provided. The apparatus main body 2 is connected to an ECG module 3a for measuring an electrocardiogram waveform (ECG waveform) of the subject PS and a PCG module 3b for measuring a cardiac sound waveform (PCG: phonocardiogram waveform).

  In addition to the overall controller 11 serving as a control center for the entire apparatus, the apparatus body 2 includes various units (described later) whose operations can be controlled based on control signals from the overall controller 11. That is, the apparatus main body 2 includes a transmission / reception unit (T / R) 21 connected to the ultrasonic probe 1. The transmission / reception unit 21 includes, as components on the transmission side (not shown), a pulser that is connected to the ultrasonic probe 1 and excites each piezoelectric vibrator, and a delay line that supplies a drive signal that delays the pulser (when receiving) And a reference oscillator for providing a reference clock to the delay line, and a preamplifier connected to each piezoelectric vibrator of the ultrasonic probe 1 as an unillustrated component on the receiving side, and an output signal of the preamplifier A delay line that gives a delay to the delay line, and an adder for phasing and adding an output signal given a delay from the delay line are incorporated.

  In addition, the apparatus main body 2 includes a detector (EP) 22 for adding logarithmic amplification and envelope detection of the adder output to the output side of the T / R 21, and the detection output of the B mode tomogram and M mode. A digital scan converter (DSC) 23 that converts ultrasonic scanning signals to standard TV scanning signals as image signals such as images, and the converted signals of the DSC 23 via a D / A converter 24 as B-mode tomographic images, etc. An output device 25 (display device 25a and audio output device 25b) for displaying or outputting sound is included.

  The main body 2 has a two-channel reference signal from the reference transmitter and its 90 degree position as a signal processing system related to the Doppler mode (CW / PW) mode and the like on the output side of the T / R 21. A phase detection mixer 26 that mixes a reference signal having a phase difference and an adder output of T / R21, and a high frequency component in the mixed signal is removed to obtain a Doppler signal consisting only of a Doppler shift frequency component, Among them, a range gate (RG) processing unit 27 having a low-pass filter and a sample hold circuit for extracting a Doppler signal at a desired depth position in the subject PS (a position specified by a range gate corresponding to ROI), A Hyper as a Doppler filter that extracts a Doppler signal of a blood flow BL to be detected by removing unnecessary low-frequency Doppler signals such as a blood vessel wall and a heart wall that are relatively slow moving from the output. A filter (HPF) 28 and a fast Fourier transformer (FFT) 29 that performs frequency analysis on the output of the Doppler signal, obtains a Doppler spectrum signal as the analysis result, and outputs the Doppler spectrum signal to the DSC 23 are provided. . Thereby, for example, a Doppler spectrum image is displayed on the display 25a together with a B-mode tomographic image.

  Further, in the apparatus main body 2, as a signal processing system related to the CFM mode, an MTI filter that removes unnecessary fixed reflection signals such as a heart wall from the output of the mixer 26 and an autocorrelation method for the output are provided on the output side of the mixer 26. A CFM processing unit that performs average velocity calculation, variance calculation, and power calculation of each point using the two-dimensional blood flow information (velocity, direction, and variance of the blood flow BL), which is the calculation result, to the DSC 23. (CFM · FP) 30 is connected. Thereby, on the display 25a, for example, blood flow information on a B-mode tomographic image, for example, the velocity of the blood flow BL is luminance, the direction is red and blue, and the dispersion is green hue. Displayed as color information.

  Further, the apparatus main body 2 receives the Doppler spectrum signal from the range gate processing unit 27 as the main configuration of the ultrasonic diagnostic apparatus (auto-trace device, peak detection device, and auto-measurement device as waveform data generation means). A DSP (Digital Signal Processor) 31 having a function of tracing the position of the maximum velocity Vp and average velocity Vm in the frequency direction of the spectrum in the time direction and detecting the trace waveform in real time, and Vp from the DSP 31 Based on the PS / ED detection unit 32 having a function of detecting the above-mentioned PS / ED peak position from the Vm trace waveform in real time or after freezing, and the PS / ED information detected by the PS / ED detection unit 32 Various parameters related to the diagnosis of HR, PI and RI (Resistance Index) of blood flow and pulsatile flow in blood vessels And a measuring unit 33 having a function of measuring a meter. Among these, the PS / ED detection unit 32 and the measurement unit 33 are mounted as application software constituting software components executed by a computer mounted on the apparatus main body 2, for example.

  The tracing method of the maximum flow velocity Vp and the average velocity Vm and the detection method of the peak position of PS / ED are arbitrary, but for detailed examples, for example, Japanese Patent Application Laid-Open No. 2003-284718 and US Pat. No. 5,628,321. Is disclosed.

  Each output of the DSP 31 and the measurement unit 33 is supplied to the DSC 23 via the I / F 34. As a result, PS / ED and each measurement result are displayed in real time on the trace waveform image of Vp and Vm on the display 25a. The trace waveform data of Vp and Vm of the DSP 31 is held in the image storage unit 35 and can be supplied to the PS / ED detection unit 32 after freezing.

  In the example shown in FIG. 2, the DSP 31 is configured by integrally mounting the functions of the high-pass filter 28 and the FFT 29 described above, and functionally, a desired position in the subject PS designated by the range gate from the range gate processing unit 27. A wall filter 41 for extracting the Doppler signal of the blood flow BL to be detected by performing the same processing as the above-described high-pass filter 28 from the Doppler signal, and the cine memory buffer 42 for the extracted Doppler signal. The FFT spectrum processing unit 43 obtains the Doppler spectrum signal by performing the same processing as the FFT 29 described above, and the Vp and Vm trace waveform detection processing unit 44 obtains the Vp and Vm trace waveforms from the spectrum signal. And a display audio / video buffer 45 for inputting the trace waveforms of Vp and Vm. Obtain.

  That is, with the Vp and Vm trace waveform detection processing unit 44 and its previous components, the ultrasonic diagnostic apparatus is provided with a function as waveform data generation means for generating waveform data representing a temporal change.

  The DSP 31 includes an audio processing unit 46 that converts the Doppler spectrum signal from the FFT spectrum processing unit 43 into an audio signal (Doppler sound) and outputs the audio signal to the display audio / video buffer 45, and an ECG module 3a. The ECG waveform data and the PCG waveform data from the PCG module 3b are subjected to predetermined waveform processing to detect an R wave trigger of the ECG waveform and S1 and S2 triggers of the PCG waveform and output them to the display audio / video buffer 45. Predetermined color processing is applied to the waveform processing unit 47 and the detection output of the M mode image and the like from the detector (EP) 22 and the two-dimensional blood flow information from the CFM processing unit (CFM / FP) 30. An M / M color processing unit 48 for outputting data such as an MC mode image to the display audio / video buffer 45; That. Further, the M / M color processing unit 48 detects a trigger linked to heartbeat synchronization from the M mode image or the MC mode image as necessary, and outputs the trigger to the display audio / video buffer 45.

  Thus, the trace waveform data from the Vp, Vm trace waveform detection processing unit 44 is supplied from the display audio / video buffer 45 to the video interface 34b via the ping-pong buffer 34a, and Vp, Vm on the display 25a. The auto trace waveform is displayed in real time. The audio signal of the Doppler signal from the audio processing unit 46 is supplied from the display audio / video buffer 45 to the audio interface 34c via the ping-pong buffer 34a, and is output as audio from the audio output device (speaker) 25b.

  In the example shown in FIG. 2, the trace waveform data from the Vp and Vm trace waveform detection processing unit 44 has a PS / ED detection unit 32 (in FIG. 2, the peak detection processing unit 32b is executed by the processing of the CPU 32a. ) And the measurement unit 33 (in FIG. 2, the real-time automatic measurement processing unit 33a and the re-measurement processing unit 33b after cine / freeze have respective functional units) are supplied to the audio interface 34c, and the display 25a In the above, in addition to the auto trace waveforms of Vp and Vm, numerical values are displayed in real time as auto measured values based on PS / ED information.

  As shown in FIG. 1, a parameter setting circuit 36 having a function as a time axis scale setting means is connected to or built in the DSP 31 and the PS / ED detection unit 32. The parameter setting circuit 36 is operated by an operator. Connected to the user interface 37.

  As shown in FIG. 1, an operation panel circuit 38 for inputting operation signals (parameter setting, etc.) from various operating devices (switches, joystick, keyboard, mouse, etc.) on the operation panel of the apparatus body 2 is input to the user interface 37. A TCS circuit 39 for inputting an operation signal (parameter setting, etc.) from a TCS (touch command screen) screen mounted on the operation panel, and a GUI (graphical user interface) on the display 25a ) And a GUI circuit 40 for inputting an operation signal (parameter setting, etc.). The range gate (ROI) designation can be operated by the user interface 37.

  Then, the time axis scale on the horizontal axis and the cut-out position of the waveform data when the pulsating waveform data such as the Doppler spectrum waveform and auto trace waveforms of Vp and Vm are displayed on the display 25a by the parameter setting circuit 36 through the user interface 37. Can be set manually or automatically. In particular, the parameter setting circuit 36 automatically sets the time axis scale and the cut-out position of the waveform data according to the heartbeat synchronization period so that the waveform data for a predetermined heart rate is included in the time frame when displaying the waveform data. be able to.

  The parameter setting circuit 36 is appropriately provided with a parameter setting function necessary for displaying waveform data. For example, the parameter setting circuit 36 can be provided with various functions described in JP-A-2003-284718.

  In addition to the D mode image (the Doppler spectrum waveform and the Vp and Vm auto trace waveforms) as the pulsation waveform data, the parameter setting circuit 36 also displays the image representing the time change such as the M mode image. The time axis scale of the axis and the cutout position of waveform data can be set manually or automatically. Hereinafter, a D mode image will be described as an example.

  FIG. 3 is a functional block diagram showing detailed functions of the parameter setting circuit 36 in the ultrasonic diagnostic apparatus shown in FIG.

  The parameter setting circuit 36 includes a display area time axis calculation unit 36a, a sweep speed setting unit 36b, a heart rate synchronization average value calculation unit 36c, an average calculation heart rate setting unit 36d, a heart rate synchronization detection unit 36e, and a time scale cutout position setting unit. 36f is provided. In accordance with these components, for example, an automatic time axis setting function switch SW1, a sweep speed setting switch SW2, an average calculation heart rate switch SW3, a trigger selection switch SW4, and a time scale cutout position switch SW5 are displayed on the display 25a. Alternatively, the operation panel is provided as an operating device, and operation signals of these switches are given from the user interface 37 to the parameter setting circuit 36. The parameter setting circuit 36 can be constructed by reading a program into a computer, or can be configured using a circuit.

  The display area time axis calculation unit 36a has a function of calculating an appropriate time axis scale and a cutout position of the waveform data to the display 25a. At this time, the display area time axis calculation unit 36a displays waveform data including a desired heart rate N when receiving an automatic time axis setting function ON signal from the automatic time axis setting function switch SW1. When the time axis scale and waveform data cut-out position are automatically calculated according to the heartbeat synchronization period, as shown in the display 25a, when an automatic time axis setting function off (AutoTimeRange Off) signal is received The time axis scale and the cutout position of the waveform data are calculated according to the sweep speed SS designated from the user interface 37.

  However, the automatic time axis setting function switch SW1 is not provided, and the automatic time axis setting function is always turned on, and the time axis scale and the cut-out position of the waveform data are automatically calculated according to the heartbeat synchronization period. . Further, when the automatic time axis setting function is off, the time axis scale and the cut-out position of the waveform data may be calculated by any other method regardless of the sweep speed SS. In other words, the time axis scale setting method may be switched to any other setting method by an on / off operation of the automatic time axis setting function.

  Then, the time axis scale calculated by the display area time axis calculator 36a and the cut-out position of the waveform data are given to the FFT spectrum processing unit 43. The FFT spectrum processing unit 43 is the time-axis scale and the cut-out position of the waveform data. A Doppler signal in a fixed range is read from the cine memory buffer 42 and a Doppler spectrum signal for display is generated.

  Next, details of the automatic time axis setting function will be described.

When the automatic time axis setting function is off, the time axis scale Rate is calculated by the equation (1-1), and the waveform data cut-out position Xstart is calculated by the equation (1-2).
[Equation 1]
Rate = Xsize / SS (1-1)
Xstart = 0 (1-2)
Where Xsize is the number of columns on the image time axis, and SS is the sweep speed. The sweep speed SS can be set to a discrete set value such as a screen scroll time 1, 2, 4, 6, 8 seconds or the like. The sweep speed SS is acquired by the sweep speed setting unit 36b as operation information of the sweep speed setting switch SW2 from the user interface 37, and is given from the sweep speed setting unit 36b to the display area time axis calculation unit 36a. That is, the sweep speed SS can be arbitrarily set as a discrete value by the user interface 37.

  FIG. 4 is a conceptual diagram for explaining an example of setting the time axis scale and waveform data extraction position when the automatic time axis setting function is turned off, and FIG. 5 is the sweep speed in the Doppler auto trace waveform shown in FIG. FIG. 6 is a diagram showing an image displayed in the time frame of the display unit 25a when SS is 2 s. FIG. 6 is a time frame of the display unit 25a when the sweep speed SS is 4 s in the Doppler auto trace waveform shown in FIG. It is a figure which shows the image displayed on.

  4, 5, and 6, the horizontal axis represents time (s), the vertical axis represents blood flow velocity (cm / s), and the broken line represents a Doppler auto trace waveform as an example of waveform data to be displayed. . The inverted triangle mark indicates the PS detected by the PS / ED detector 32, and the triangle mark indicates the ED detected by the PS / ED detector 32.

  When the sweep speed SS is 2s and 4s, the time axis scale Rate is set so that the range shown in FIG. 4 is the range displayed in the time frame. Further, the cut-out position Xstart of the waveform data is the latest time phase. For example, when the scroll moves from left to right as shown in FIG. 4, since the right end is the current latest time phase, the cut-out position Xstart of the waveform data is the right end.

  Therefore, the image displayed in the time frame of the display 25a is as shown in FIG. 5 when the sweep speed SS is 2 s and as shown in FIG. 6 when the sweep speed SS is 4 s. In FIGS. 5 and 6, the Doppler auto trace waveform is displayed in the time frame of the display 25a regardless of the heart rate.

On the other hand, when the automatic time axis setting function is ON, the time axis scale Rate is calculated by the equation (2-1) so that the waveform data including the desired heart rate N is displayed on the display 25a. The cut-out position Xstart of is calculated by the equation (2-2).
[Equation 2]
Rate = Xsize / {(MHR / 60) × (N + 2α)} (2-1)
Xstart = α × MHR (2-2)
However, MHR is a heartbeat synchronization average period (average period of each heartbeat to be synchronized), N is a heart rate included in the waveform data to be displayed, α is a parameter for designating the cutout position and the display range of the waveform data, and is arbitrarily set Can be set.

  FIG. 7 is a conceptual diagram for explaining an example of setting a time axis scale and a waveform data extraction position when the automatic time axis setting function is turned on, and FIG. 8 is a heart rate in the Doppler auto trace waveform shown in FIG. FIG. 9 is a diagram showing an image displayed in the time frame of the display 25a when N is 2, FIG. 9 is a time frame of the display 25a when the heart rate N is 3 in the Doppler autotrace waveform shown in FIG. It is a figure which shows the image displayed on.

  7, 8, and 9, the horizontal axis represents time (s), the vertical axis represents blood flow velocity (cm / s), and the broken line represents a Doppler autotrace waveform as an example of waveform data to be displayed. . The inverted triangle mark indicates the PS detected by the PS / ED detector 32, and the triangle mark indicates the ED detected by the PS / ED detector 32.

  When the time axis scale Rate and the waveform data cutout position Xstart are set according to the equations (2-1) and (2-2), the time scale Rate becomes the time corresponding to the heart rate N + α to be displayed, and the waveform data cutout position Xstart. Is the measurement start point close to the latest time phase.

  For example, when the heart rate N is 2 heartbeats and 3 heartbeats, the time axis scale Rate is set so that the range shown in FIG. 7 is the range displayed in the time frame. The waveform data cut-out position Xstart is shifted by α × MHR from the latest time phase. For example, when the scroll moves from left to right as shown in FIG. 7, since the right end is the current latest time phase, the waveform data cut-out position Xstart is shifted to the left by α × MHR from the right end.

  Therefore, the image displayed in the time frame of the display 25a is as shown in FIG. 8 when the heart rate N is 2 heartbeats and as shown in FIG. 9 when the heart rate N is 3 heartbeats. 8 and 9, Doppler auto trace waveforms for a desired heart rate are displayed in the time frame of the display 25a.

  That is, the waveform of the past N heartbeats from the position of α (before time) of the time phase of the heartbeat waveform trigger (for example, the detection point of ED of the Doppler autotrace waveform as shown in FIG. 7) that is the measurement feature point. The time axis scale Rate and the waveform data cutout position Xstart can be set so that the data falls within the display frame of the display 25a.

  The heartbeat synchronization average period MHR is calculated by the heartbeat synchronization average value calculation unit 36c and given to the display region time axis calculation unit 36a. The calculation of the heart rate synchronization average period MHR requires the number of heartbeats (heart rate N) displayed on the time axis and heart rate synchronization. Therefore, the average calculation heart rate N used for calculating the heart rate synchronization average period MHR is arbitrarily set by the average calculation heart rate setting unit 36d as operation information of the average calculation heart rate (Auto Time Scale HRNumber) switch SW3 from the user interface 37. And is provided from the average calculation heart rate setting unit 36d to the heart rate synchronization average value calculation unit 36c. In addition, the heartbeat synchronization used for calculating the heartbeat synchronization average period MHR is detected by the heartbeat synchronization detection unit 36e based on the waveform trigger, and the detected heartbeat synchronization is provided from the heartbeat synchronization detection unit 36e to the heartbeat synchronization average value calculation unit 36c. .

  Here, waveform triggers for detecting heartbeat synchronization include PS and ED of Doppler autotrace waveforms, and A wave and E wave peaks of Doppler autotrace waveforms that can be detected at the time of left ventricular (LV) diagnosis. It is possible to select from any R-wave trigger of the ECG signal, S1, S2 trigger of the PCG signal, and a trigger associated with the heartbeat period of the M mode waveform or MC mode waveform.

  The selection of the waveform trigger can be performed by operating the trigger selection (HRCSel) switch SW4, and is given from the user interface 37 to the heartbeat synchronization detector 36e. That is, the parameter setting circuit 36 is provided with a switching function of a waveform trigger that is an input signal to the heartbeat synchronization detection unit 36e.

  The heartbeat synchronization detection unit 36e acquires the selected waveform trigger from the PS / ED detection unit 32 and the display audio / video buffer 45. However, waveform triggers such as ECG signal R-wave triggers, PCG signal S1, S2 triggers, triggers linked to the heartbeat period of M-mode waveforms and MC-mode waveforms, directly from the waveform processing unit 47 and the M / M color processing unit 48. May be obtained. Further, the PS / ED detector 32 is appropriately provided with a function for detecting A wave and E wave peaks of the Doppler auto trace waveform, or a separate A wave and E wave peak detector is provided.

  On the other hand, the parameter α is acquired by the time scale cutout position setting unit 36f as operation information of the time scale cutout position switch (Trace Disp Start) SW5 from the user interface 37, and from the time scale cutout position setting unit 36f to the display area time axis calculation unit. 36a. That is, the parameter α can be arbitrarily set by the user interface 37.

  However, the value of the practical parameter α is a value of about 0% to 50% of the average cycle of the heart rate N set by the average calculation heart rate switch SW3. For this reason, the value of the parameter α can be a value of 50% to 100%, a value of 100% or more, or a negative value, but it is about 0% to 50% of the average cycle of the heart rate N. It is sufficient if the value can be set arbitrarily.

  FIG. 10 is a diagram illustrating a setting example of a Doppler auto trace waveform to be displayed and a time scale.

  In FIG. 10, the horizontal axis represents time (s), the vertical axis represents blood flow velocity (cm / s), and the image represents a spectrum to be displayed and a Doppler autotrace waveform. When displaying such an image in the time frame of the display 25a, the time axis scale Rate can be set with the automatic time axis setting function turned off and the sweep speed SS set to 2s, 4s. It is also possible to set the time axis Rate with the function turned on and the heart rate N as 2 and 3 heartbeats. When the automatic time axis setting function is turned on, the cut-out position Xstart of the waveform data can be adjusted by the parameter α.

  11 shows an image displayed in the time frame of the display 25a when the sweep speed SS is 2 s in the image data shown in FIG. 10, and FIG. 12 shows the sweep speed SS in the image data shown in FIG. FIG. 13 is a diagram showing an image displayed in the time frame of the display 25a when 4 s is set, and FIG. 13 is displayed in the time frame of the display 25a when the heart rate N is 2 in the image data shown in FIG. FIG. 14 is a diagram showing an image, and FIG. 14 is a diagram showing an image displayed in the time frame of the display 25a when the heart rate N is 3 in the image data shown in FIG.

  11, 12, 13, and 14, the horizontal axis represents time (s), the vertical axis represents blood flow velocity (cm / s), and the image represents the spectrum to be displayed and the Doppler auto trace waveform.

  As shown in FIGS. 11, 12, 13, and 14, according to the parameter setting circuit 36, the sweep speed for determining the time axis scale is set to, for example, 1, 2, 4, 6, 8 seconds as in the prior art. It can be set discretely as in the case, and the time axis scale and the cut-out position of the waveform data are set according to the heartbeat synchronization period so that the waveform data for the desired heart rate falls within the time frame of the display 25a. It can also be set automatically.

  For this reason, even if the heart rate varies depending on the subject, if the time axis scale and the cutout position of the waveform data are automatically set so that the waveform data for the desired heart rate falls within the time frame of the display 25a, the heart rate The waveform data of several heartbeats necessary for measurement can be appropriately displayed without excess or deficiency without the waveform being interrupted.

  Such automatic setting of the time axis scale and the cut-out position of the waveform data can be independently performed both when displaying the waveform data in real time during the live and when displaying the waveform data after freezing.

  FIG. 15 is a flowchart showing the flow of processing when individually setting the heart rate of waveform data to be displayed in the time frame of the display 25a during live and after freezing by the ultrasonic diagnostic apparatus shown in FIG. In the figure, reference numerals with numerals S denote steps in the flowchart.

  First, in step S1, the displayed heart rate N at the time of live is input to the parameter setting circuit 36 by operating the average calculation heart rate switch SW3 via the user interface 37 in advance. The automatic time axis setting function is turned on by operating the automatic time axis setting function switch SW1. Further, the parameter α is input to the parameter setting circuit 36 by operating the time scale cutout position switch SW5. For example, the trigger selection switch SW4 selects PS and ED of the Doppler auto trace waveform as the waveform trigger.

  Therefore, the displayed heart rate N and the parameter α are acquired by the average calculation heart rate setting unit 36d and the time scale cutout position setting unit 36f, respectively. Then, the average calculation heart rate setting unit 36d gives the acquired display heart rate N to the heart rate synchronization average value calculation unit 36c, and the time scale cutout position setting unit 36f supplies the acquired parameter α to the display region time axis calculation unit 36a. To give.

  Next, in step S2, data collection is performed by transmission / reception of ultrasonic waves, and the collected data is transmitted via the transmission / reception unit (T / R) 21, mixer 26, and range gate (RG) processing unit 27 shown in FIG. 2 is given to a wall filter 41 of the DSP 31 shown in FIG. In the wall filter (Wall Filter) 41, the Doppler signal of the blood flow BL, which is time change data, is sequentially extracted by time change data preprocessing.

  Next, in step S3, the Doppler signals extracted by the wall filter 41 are sequentially recorded in the cine memory buffer 42 having a storage function. For this reason, the cine-memory buffer 42 sequentially stores past time-series Doppler signal data that changes on the time axis for a plurality of heartbeats.

  FIG. 16 is a conceptual diagram showing an example of Doppler signal data recorded in the cine memory buffer 42 of the DSP 31 shown in FIG.

  In FIG. 16, the circumferential direction indicates time. The alternate long and short dash line indicates the timing of the heartbeat. As shown in FIG. 16, in the loop area in the cine memory buffer 42, the current Doppler signal data from the past is updated and stored sequentially in the loop so as to circulate.

  Next, in step S4, the Doppler signal data in the cine memory buffer 42 is sequentially read into the FFT spectrum processing unit 43, and the time spectrum data post processing is executed in the FFT spectrum processing unit 43. That is, the FFT spectrum processing unit 43 performs frequency analysis of Doppler signal data by FFT, and a Doppler spectrum signal is obtained as an analysis result. Further, the Doppler spectrum signal is supplied from the FFT spectrum processing unit 43 to the Vp and Vm trace waveform detection processing unit 44, and the Vp and Vm trace waveform detection processing unit 44 obtains Vp and Vm trace waveforms in real time. The trace waveforms of Vp and Vm are output from the Vp and Vm trace waveform detection processing unit 44 to the display audio / video buffer 45 and temporarily stored.

  Next, the trace waveforms of Vp and Vm stored in the display audio / video buffer 45 are read into the PS / ED detector 32, and the peak position of the PS / ED is detected in real time. If necessary, the peak position of PS / ED is given to the measurement unit 33, and various parameters relating to diagnosis such as blood flow in the blood vessel and HR, PI, and RI (Resistance Index) of the pulsatile flow are measured. The

  Further, the PS / ED peak position detected by the PS / ED detector 32 is provided to the heartbeat synchronization average value calculator 36 c via the heartbeat synchronization detector 36 e of the parameter setting circuit 36. Then, the heart rate synchronization average value calculation unit 36c calculates the heart rate synchronization average period MHR from the display heart rate N received from the average calculation heart rate setting unit 36d and the peak position of the PS / ED, and displays it together with the display heart rate N. This is given to the region time axis calculator 36a.

  Then, the display area time axis calculation unit 36a uses the heartbeat synchronization average period MHR, the displayed heart rate N, and the parameter α received from the time scale cutout position setting unit 36f, to obtain an appropriate time axis scale and waveform to the display 25a. The data cut-out position can be calculated by the equations (2-1) and (2-2).

  As a result, the obtained time axis scale and the cut-out position of the waveform data are given to the FFT spectrum processing unit 43. Then, the FFT spectrum processing unit 43 sets the time determined by the parameter α to the heart rate N set in the parameter setting circuit 36 based on the time axis scale obtained by the display area time axis calculation unit 36a and the cutout position of the waveform data. The Doppler signal data for the added time is read from the cine memory buffer 42 and a Doppler spectrum signal for display is generated.

  For example, Doppler spectrum signals and Vp and Vm trace waveforms are generated from the Doppler signal data D1 for six heartbeats indicated by the dotted arrows in FIG.

  Next, in step S5, the Doppler spectrum signal, Vp, Vm trace waveform and the detected PS / ED peak position generated in this way are supplied to the video interface 34b and are subjected to time-varying data display processing. Then, it is displayed in real time as an autotrace waveform of Vp and Vm for a predetermined heart rate on the display 25a.

  The display range of the auto trace waveform of Vp, Vm (display heart rate and waveform data cut-out position) can be changed and reset after freezing.

  In that case, in step S 6, the display heart rate N after freezing and the cut-out position of the waveform data are reset by the parameter setting circuit 36 via the user interface 37.

  For example, as indicated by the two-dot chain line arrow in FIG. 16, the Doppler signal data D2 for four heartbeats, which is smaller than that at the time of live, can be used as a range used for generating Doppler spectrum signals, Vp, and Vm trace waveforms. That is, it is possible to set a larger heart rate to be displayed by enlarging the horizontal scale during live performance, and to set the heart rate so that the waveform data can be optimally extracted after freezing.

  After the freeze, when the displayed heart rate N and the cutout position of the waveform data are reset, the corresponding Doppler signal data is read into the FFT spectrum processing unit 43 again in step S4, and the time change data post process is executed. The Furthermore, Vp and Vm trace waveforms are generated. For this reason, it becomes possible to display on the display 25a an accurate image suitable for the purpose of measurement or the like.

  That is, the ultrasonic diagnostic apparatus as described above has a function of automatically setting the sweep speed so that the Doppler waveform data of the required heart rate is displayed with a certain margin on the display frame of the display 25a. Device. This makes it possible to display an image in a desired range appropriately when displaying an image representing a change in time such as the D mode or the M mode, thereby shortening the time required for optimizing the spectrum image or Doppler measurement. Can do.

1 is a configuration diagram showing an embodiment of an ultrasonic diagnostic apparatus. FIG. 2 is a detailed configuration diagram of a DSP, a PS / ED detection unit, and a measurement unit in the ultrasonic diagnostic apparatus shown in FIG. 1. The functional block diagram which shows the detailed function of the parameter setting circuit in the ultrasonic diagnosing device shown in FIG. The conceptual diagram for demonstrating the example of a setting of the time-axis scale and the cut-out position of waveform data when an automatic time-axis setting function is turned off. The figure which shows the image displayed on the time frame of a display, when sweep speed is 2 s in the Doppler auto trace waveform shown in FIG. The figure which shows the image displayed on the time frame of a display, when sweep speed is 4 s in the Doppler auto trace waveform shown in FIG. The conceptual diagram for demonstrating the example of a setting of the time-axis scale and the cut-out position of waveform data when an automatic time-axis setting function is set to ON. The figure which shows the image displayed on the time frame of a display, when the heart rate is set to 2 in the Doppler auto trace waveform shown in FIG. The figure which shows the image displayed on the time frame of a display, when the heart rate is set to 3 in the Doppler auto trace waveform shown in FIG. The figure which shows the setting example of the Doppler auto trace waveform used as a display object, and a time scale. The figure which shows the image displayed on the time frame of a display, when the sweep speed is 2 s in the image data shown in FIG. The figure which shows the image displayed on the time frame of a display, when the sweep speed is 4 s in the image data shown in FIG. The figure which shows the image displayed on the time frame of a display, when the heart rate is set to 2 in the image data shown in FIG. The figure which shows the image displayed on the time frame of a display, when the heart rate is set to 3 in the image data shown in FIG. The flowchart which shows the flow of a process in the case of setting individually the heart rate of the waveform data each displayed on the time frame of a display by the ultrasonic diagnostic apparatus shown in FIG. 1 after a live and after freezing. The conceptual diagram which shows an example of the Doppler signal data recorded on the cine memory buffer of DSP shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ultrasonic probe 2 Apparatus main body 3a ECG module 3b PCG module 11 Whole controller 21 Transmission / reception part (T / R)
22 Detector (E / P)
23 Digital Scan Converter (DSC)
24 D / A converter 25 Output device 25a Display device 25b Audio output device (speaker)
26 Mixer 27 Range Gate (RG) Processing Unit 28 High Pass Filter (HPF)
29 Fast Fourier Transform (FFT)
30 CFM processing unit (CFM / FP)
31 DSP
32 PS / ED detector 33 Measuring unit 34 I / F
34a Ping-pong buffer 34b Video interface 34c Audio interface 35 Image storage unit 36 Parameter setting circuit 36a Display region time axis calculation unit 36b Sweep speed setting unit 36c Heart rate synchronization average value calculation unit 36d Average calculation heart rate setting unit 36e Heart rate synchronization detection unit 36f Time scale cutout position setting unit 37 User interface 38 Operation panel circuit 39 TCS circuit 40 GUI circuit 41 Wall filter
42 Cine Memory Buffer 43 FFT Spectrum Processing Unit 44 Vp, Vm Trace Waveform Detection Processing Unit 45 Display Audio Video Buffer 46 Audio Processing Unit 47 Waveform Processing Unit 48 M / M Color Processing Unit SW1 Automatic Time Base Setting Function Switch SW2 Sweep Speed setting switch SW3 Heart rate switch SW4 for average calculation Trigger selection switch SW5 Time scale cutting position switch

Claims (7)

A heartbeat cycle calculating means for calculating a heartbeat cycle by heartbeat synchronization;
Waveform data generating means for generating Doppler signal data ;
Doppler spectrum generation means for obtaining a Doppler spectrum based on the Doppler signal data;
Storage means for storing the Doppler spectrum;
A time phase detection means for detecting a time phase of a feature point based on the Doppler spectrum;
A time axis scale setting means for setting a time axis scale for a desired heart rate based on the heartbeat cycle ;
Reading means for reading at least a part of the Doppler spectrum stored in the storage means as a display Doppler spectrum based on the time axis scale and the time phase of the feature point;
Display means for displaying the display Doppler spectrum;
An ultrasonic diagnostic apparatus comprising: The reading means displays the Doppler spectrum related to the time domain from the time phase of the feature point to the time phase retroactive to the desired heart rate based on the time axis scale and the time phase of the feature point. The ultrasonic diagnostic apparatus according to claim 1, wherein the ultrasonic diagnostic apparatus is read out as a Doppler spectrum . An input means for receiving an input operation;
The ultrasonic diagnostic apparatus according to claim 1 or 2, characterized in that said time phase detecting means for setting the type of a feature point to be detected and the heart rate based on the input operation. The time axis scale setting means includes a waveform peak of a Doppler auto trace waveform, an R wave trigger of an ECG signal, an S1 trigger of a PCG signal, an S2 trigger of a PCG signal, a trigger linked to a heartbeat cycle of an M mode waveform, and an MC mode waveform. detecting the heartbeat-synchronous at least one trigger in conjunction with the heartbeat cycle as switchable trigger claims 1 to 3, characterized by being configured to set the time axis scale based on the heartbeat-synchronous detected The ultrasonic diagnostic apparatus according to any one of the above. The said time-axis scale setting means was comprised so that the said time-axis scale could be set separately in each at the time of live and after freezing, The one of Claim 1 thru | or 4 characterized by the above-mentioned. Ultrasonic diagnostic equipment. The ultrasonic diagnostic apparatus according to any one of claims 1 to 5, wherein the reading unit is configured to be able to set the time region individually during live and after freezing. . Calculating a cardiac cycle by heartbeat synchronization;
Generating Doppler signal data;
Obtaining a Doppler spectrum based on the Doppler signal data;
Storing the Doppler spectrum;
Detecting a time phase of a feature point based on the Doppler spectrum;
Setting a time axis scale for a desired heart rate based on the heartbeat cycle ;
Reading at least a part of the stored Doppler spectrum as a display Doppler spectrum based on the time axis scale and the time phase of the feature point;
Displaying the display Doppler spectrum on a display means ;
A method for displaying an ultrasonic diagnostic image, comprising:

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