JP7082540B2 - Doppler waveform processing device - Google Patents

Description

The present invention relates to a Doppler waveform processing apparatus, and more particularly to processing a trace line generated by tracing a Doppler waveform.

The Doppler waveform processing device is composed of an ultrasonic diagnostic device, an information processing device, and the like having a function of processing Doppler waveforms. In the following, an ultrasonic diagnostic apparatus having a function of processing Doppler waveforms will be described.

Such an ultrasonic diagnostic apparatus is provided with a PW mode (pulse Doppler mode) and a CW mode (continuous wave Doppler mode). These modes are modes in which Doppler information is obtained from blood flow in the living body (blood flow in blood vessels, blood flow in the heart, etc.) and a Doppler waveform representing the frequency analysis result is displayed. The horizontal axis of the Doppler waveform is the time axis, and the vertical axis thereof is the frequency axis (velocity axis). The Doppler waveform changes periodically according to the heartbeat. The auto-trace function installed in the ultrasonic diagnostic equipment automatically traces the outer shape of the generated Doppler waveform (the line corresponding to the maximum flow velocity or a flow velocity close to it), which automatically generates a trace line. .. The trace line is the measurement target.

Patent Document 1 discloses an ultrasonic diagnostic apparatus having an auto trace function. In such an ultrasonic diagnostic apparatus, the maximum flow velocity and the minimum flow velocity included in the trace line are detected for each heartbeat.

Japanese Unexamined Patent Publication No. 7-241290

When diagnosing the circulatory system, measurement is performed based on the trace line generated based on the Doppler waveform. For example, the maximum flow velocity and the minimum flow velocity are measured for each measurement section as the heart rate period, and the measured value is calculated based on them. In that case, under the situation where a biological signal (for example, an electrocardiographic signal) is obtained, each measurement section is specified based on the biological signal. On the other hand, in a situation where no biological signal is obtained, it is necessary to specify each measurement section based on the trace line itself. Specifically, for example, the measurement section is located at or near the root of the rising portion in the trace line. It is necessary to determine the starting phase of.

An object of the present invention is to accurately determine a measurement section based on a trace line. Alternatively, an object of the present invention is to accurately determine the start time phase of the measurement section even if the trace line contains fluctuations.

The Doppler waveform processing apparatus according to the present invention has a generation means for generating a rising portion representative line representing the rising portion and a rising portion representative based on the rising portion included in the trace line generated by tracing the Doppler waveform. It is characterized by including a determination means for determining a time phase for specifying a measurement section based on a line.

The program according to the present invention is a program for executing the Doppler waveform processing method in the Doppler waveform processing apparatus, and represents the rising portion based on the rising portion included in the trace line generated by the trace of the Doppler waveform. It is characterized by including a function of generating a rising portion representative line and a function of determining a time phase for specifying a measurement section based on the rising portion approximation line.

According to the present invention, it is possible to accurately determine the measurement section based on the trace line. Alternatively, according to the present invention, it is possible to accurately determine the start time phase of the measurement section even if the trace line contains fluctuations.

It is a block diagram which shows the ultrasonic diagnostic apparatus as a Doppler waveform processing apparatus which concerns on embodiment. It is a figure which shows the Doppler waveform processing method which concerns on a comparative example. It is a flowchart which shows the Doppler waveform processing method which concerns on embodiment. It is a figure which shows the peak identification method. It is a figure which shows the rising part representative line. It is a figure which shows an example of a recent contact. It is a figure which shows the other example of a recent contact. It is a figure which shows the intersection of the 1st representative line and the 2nd representative line. It is a figure which shows the Doppler waveform processing method which concerns on embodiment. It is a figure which shows the modification of the 2nd representative line.

Hereinafter, embodiments will be described with reference to the drawings.

(1) Outline of the Embodiment The Doppler waveform processing apparatus according to the embodiment has a generation means (first generation means) and a determination means. The generation means generates a rising portion representative line (first representative line) representing the rising portion based on the rising portion included in the trace line generated by tracing the Doppler waveform. The determination means determines the time phase for specifying the measurement section based on the rising portion representative line. In general, the rising edge can be clearly identified in the trace line. Moreover, it is generally a steep part with respect to the time axis. In the above configuration, the measurement section is stably determined by using such a rising portion as a reference on the time axis. Only one measurement section may be set, or a plurality of measurement sections may be set sequentially. The measurement section specific time phase may be the start time phase of the measurement section or may be the reference time phase that defines the start time phase.

In the embodiment, the above-mentioned generation means is the first generation means, and the second generation means for generating the bottom portion representative line which is a portion included in the trace line and represents the bottom portion generated on the front side of the rising portion is provided. The determination means determines the time phase for specifying the measurement section based on the rising portion representative line and the bottom portion representative line. This configuration objectively sets the measurement section based on the bottom portion representative line (second representative line) and the rising portion representative line (first representative line) representing the adjacent bottom portion and rising portion on the time axis, respectively. It is to be decided. For example, fluctuations are likely to occur in the bottom portion, and if the minimum value contained therein is set as the start time phase of the measurement section, the start time phase will be different for each heartbeat. According to the above configuration, since the start time phase can be defined based on the two representative lines, it is less likely to be affected by the fluctuation included in the bottom portion.

In the embodiment, the determination means include a means for specifying the intersection of the rising portion representative line and the bottom portion representative line, and a means for determining the measurement section start time phase as the time phase for specifying the measurement section based on the intersection. including. Since the rising portion representative line is usually configured as a steep diagonal line with respect to the time axis and the intersection is defined on the rising representative line, the intersection is usually set on the front side of the rising portion as a reference. .. Even if the position of the bottom representative line in the velocity axis direction changes slightly, the intersection does not change significantly on the time axis. Therefore, according to the above configuration, it is possible to stably set the start time phase at or near the root of the rising portion (or at or near the boundary between the bottom portion and the rising portion).

In the embodiment, the rising portion representative line is a diagonal line and the bottom portion representative line is a horizontal line. The two straight lines are representative of each part, and by using them as a reference, it is possible to stably determine the measurement section without being affected by the fluctuation included in the trace line. It is also possible to think of each straight line as an approximate line.

In the embodiment, the generation means (first generation means) is a means for specifying a first representative point representing the rising portion and a line passing through the first representative point as the rising portion representative line, which is an approximation of the rising portion. Includes means for computing lines. The first representative point can be determined as an intermediate point, a maximum gradient point, and others. The approximate line passing through the first representative point can be easily obtained by mathematical processing.

In the embodiment, the second generation means includes means for specifying a second representative point representing the bottom portion, and means for calculating a horizontal line passing through the second representative point as the bottom portion representative line. According to this configuration, it is possible to calculate the bottom partial representative line by a simple process. Even if the height of the bottom representative line as a horizontal line changes slightly, it is possible to stably determine the start time phase of the measurement section with reference to the rising portion representative line as a steep diagonal line. The second representative point can be determined as a baseline recent contact point, an average velocity point, or the like.

In the embodiment, the means for identifying the second representative point is the closest to the baseline at a point that satisfies a predetermined condition when the bottom portion does not have a backflow portion that extends beyond the baseline and enters the opposite side. If the point is specified as the second representative point and the bottom portion has a backflow portion that extends beyond the baseline and enters the opposite side, the point on the baseline that meets the predetermined conditions is the second representative point. Specify as. For example, if a mere minimum speed point is adopted as the second representative point, the second representative point may be specified at an unexpectedly early point in time when there is backflow. The above configuration avoids such a problem. According to the above configuration, it is possible to accurately determine the start time phase at or near the root of the rising portion on the premise that the entire rising portion is included on one side (non-backflow side) of the baseline. Will be.

The Doppler waveform processing method according to the embodiment includes a step of generating a rising portion representative line representing the rising portion and a rising portion representative line based on the rising portion included in the trace line generated by the trace of the Doppler waveform. It includes a step of determining a time phase for specifying a measurement section based on the above. This Doppler waveform processing method can be realized as a hardware function or a software function. In the latter case, a program that executes the Doppler waveform processing method is installed in the Doppler waveform processing device via a network or via a portable storage medium. The concept of the Doppler waveform processing device includes an information processing device, an ultrasonic diagnostic device, and the like.

(2) Details of the Embodiment FIG. 1 shows an ultrasonic diagnostic apparatus according to the embodiment. This ultrasonic diagnostic device is installed in a medical institution such as a hospital, and has a function of displaying a tomographic image and a Doppler waveform as an ultrasonic image by transmitting and receiving ultrasonic waves to a living body (subject). There is. PW mode and CW mode are known as typical operation modes for generating Doppler waveforms. The PW mode is a mode in which Doppler information is acquired by transmitting a pulse wave into the living body and receiving a reflected wave from the living body. The CW mode is a mode for acquiring Doppler information by transmitting a continuous wave into the living body and receiving a reflected wave (continuous wave) from the living body. In the following, the configuration and operation of the ultrasonic diagnostic apparatus will be described with a focus on the PW mode.

The ultrasonic probe 10 transmits and receives ultrasonic waves in a state of being in contact with the surface of a living body. In the present embodiment, for example, the transmission / reception surface (acoustic lens surface) of the ultrasonic probe is brought into contact with the surface of the neck, and ultrasonic diagnosis is performed on the carotid artery. Other blood vessels may be the subject of diagnosis.

The ultrasonic probe 10 has a vibrating element array composed of a plurality of vibrating elements arranged one-dimensionally. The ultrasonic beam 12 is formed by the vibrating element array, and the ultrasonic beam 12 is electronically scanned as needed. As the electronic scanning method, an electronic linear scanning method, an electronic sector scanning method, and the like are known. For example, in the B mode, the ultrasonic beam 12 is linearly electronically scanned, whereby a scanning surface having a rectangular shape is formed in the living body. The scanning surface is a two-dimensional data acquisition area. In the PW mode, the ultrasonic beam 14 is formed with respect to the designated beam direction. In the illustrated example, the ultrasonic beam 14 is tilted with respect to the central axis of the ultrasonic probe 10 so that the ultrasonic beam 14 is not orthogonal to the blood flow. A sample gate 16 for extracting Doppler information is set on the ultrasonic beam 14. The sample gate 16 is also called a sample volume or the like.

In the ultrasonic diagnosis of the carotid artery, the B mode is usually selected first, and the beam direction and the sample gate 16 are set on the B mode image. After that, the PW mode is selected, and the ultrasonic beam 14 is repeatedly formed with respect to the set beam direction. In those processes, Doppler information is sequentially acquired from the sample gate 16. B mode and PW mode may be executed at the same time.

The transmitting unit 18 is an electronic circuit that functions as a transmitting beam former, and the receiving unit 20 is an electronic circuit that functions as a receiving beam former. At the time of transmission, a plurality of transmission signals after delay processing are supplied in parallel from the transmission unit 18 to the vibrating element array. This forms a transmitting beam. At the time of reception, when the reflected wave from the living body is received by the vibrating element array, a plurality of received signals are output in parallel from the vibrating element array to the receiving unit 20. In the receiving unit 20, delay addition (phase adjustment addition) is applied to a plurality of received signals. As a result, beam data corresponding to the received beam is generated. In the B mode, one frame data is composed of a plurality of beam data arranged in the electron scanning direction. Each beam data is composed of a plurality of echo data arranged in the depth direction. In the PW mode, as described above, a plurality of beam data are sequentially formed on a specific beam direction, whereby a plurality of Doppler information is sequentially acquired.

The tomographic image forming unit 22 is a circuit for B mode, and specifically, is an electronic circuit that forms a B mode tomographic image based on frame data. The tomographic image forming unit 22 has a digital scan converter (DSC) and the like. The DSC has a coordinate conversion function, a pixel interpolation function, a frame rate conversion function, and the like. The generated tomographic image data is sent from the tomographic image forming unit 22 to the display processing unit 32. The circuit for processing the beam data and the like are not shown in the figure.

The Doppler waveform processing unit 21 executes the Doppler waveform processing method in the embodiment. The Doppler waveform processing unit 21 is composed of a Doppler waveform forming unit 24, a trace unit 26, a measurement section setting unit 28, a measurement unit 30, and a display processing unit 32. Specifically, the Doppler waveform processing unit 21 is composed of one or a plurality of processors. The Doppler waveform processing unit 21 may be realized as a function of a program executed on a CPU, which will be described later. The Doppler waveform processing unit 21 may be constructed on an information processing device such as a PC. The tomographic image forming unit 22 may be included in the Doppler waveform processing unit 21. Hereinafter, each configuration of the Doppler waveform processing unit 21 will be specifically described.

The Doppler waveform forming unit 24 is a Doppler waveform forming means that functions when the PW mode is selected, and includes a frequency analyzer, a Doppler waveform generator, and the like. The Doppler waveform forming unit 24 sequentially executes frequency analysis on a plurality of input Doppler information, and generates a Doppler waveform by mapping a series of power spectra obtained thereby on the time axis. Even when the CW mode is selected, the Doppler waveform is generated by the same processing. The generated Doppler waveform data is sent to the display processing unit 32 and the trace unit 26.

The trace unit 26 is a tracing means for executing an auto trace on the Doppler waveform. For example, in each time phase, a point having the maximum flow velocity or a predetermined flow velocity in the Doppler waveform is specified, and a trace line is configured according to the specified result. The trace line corresponds to the outline of the Doppler waveform. In the embodiment, the carotid artery is the object of observation, and in general, Doppler has a form in which the carotid artery repeatedly fluctuates with the heartbeat cycle on the positive side (or the negative side on the other side of the baseline), which is one side of the baseline. A waveform is generated.

The measurement section setting unit 28 sets one or a plurality of measurement sections on the time axis based on the form of the trace line. Each measurement section corresponds to the heart rate section. The measurement section setting unit 28 functions as a first generation means, a second generation means, a determination means, and the like. That is, the measurement section setting unit 28 generates the first representative line (rising portion representative line) based on the rising portion included in the trace line, and the first representative line (in front of the rising portion) included in the trace line. Two representative lines (bottom partial representative lines) are generated, and the start time phase of the measurement section is determined based on the intersection of the two representative lines. The specific processing contents will be described in detail based on each figure after FIG.

The measurement unit 30 is a measurement means that executes measurement in units of set measurement sections. For example, the maximum flow velocity and the minimum flow velocity in the measurement section are specified, and the measurement value for evaluating the carotid artery is calculated based on them. Data indicating the measured value is sent to the display processing unit 32.

The display processing unit 32 has a graphic image generation function, a color processing function, an image composition function, and the like, and generates a display image to be displayed on the display device 34. In the PW mode, the Doppler waveform is displayed as a display image, and necessary information such as measured values is displayed. The display 34 is composed of an LCD, an organic EL display device, and the like.

The control unit 36 is composed of a CPU and a program, and the control unit 36 controls the operation of each configuration shown in FIG. The operation panel 38 is an input device composed of a plurality of switches, a plurality of buttons, a trackball, a keyboard, and the like. The operation mode is selected by the user using the operation panel 38, and the device operating conditions are set.

FIG. 2 shows a Doppler waveform processing method according to a comparative example. The illustrated Doppler waveform 40 is generated based on Doppler information obtained from the carotid artery. The horizontal axis t is the time axis, and the vertical axis v is the speed axis. The horizontal axis t is the baseline, which corresponds to a velocity of zero. The Doppler waveform 40 is composed of a plurality of partial waveforms 42 corresponding to a plurality of heartbeats, and each partial waveform 42 includes a rising portion 42A on the front side of the peaks 44a and 44b, a falling portion 42B on the rear side of the peaks 44a and 44b, and the peaks 44a and 44b. It consists of an intermediate portion 42C that follows, and a bottom portion 42D that follows. The peaks 44a and 44b are the maximum flow velocity points for each heartbeat, and it is relatively easy to identify them.

In this comparative example, the search sections 46a and 46b are set on the front side of the peaks 44a and 44b, and the minimum flow velocity points 48a and 48b are searched in the search sections 46a and 46b. The time phase in which the minimum flow velocity points 48a and 48b exist is defined as the start time phase (start position) of the measurement section. That is, the measurement sections 50a, 50b, 50c are set based on the minimum flow velocity points 48a, 48b. Then, for example, the maximum flow velocity and the minimum flow velocity are specified in each measurement section 50a, 50b, 50c, and the measurement value is calculated in heartbeat units based on them. In the illustrated example, the bottom portion 42D contains fluctuations. The search sections 46a and 46b cover all or part of such a bottom portion 42D, and are susceptible to fluctuations when identifying the minimum flow velocity points 48a and 48b. Therefore, the time phase of the minimum flow velocity points 48a and 48b is not stable, the lengths of the respective measurement sections 50a, 50b and 50c are different, and in some cases, the minimum flow velocity may be misidentified.

On the other hand, in the Doppler waveform processing method according to the embodiment, the start time phase of the measurement section can be determined stably and objectively. In particular, it is not easily affected by fluctuations at the bottom. Hereinafter, the Doppler waveform processing method shown as a flowchart in FIG. 3 will be described in detail with reference to FIGS. 4 to 9. The elements already described in each figure are designated by the same reference numerals and the description thereof will be omitted.

FIG. 3 shows the processing after the trace line is generated. This process is executed for each heartbeat in the measurement section setting unit 28. In S10, the peak included in the trace line is detected. For example, peaks are specified in order from the left side in the trace line to be processed.

When specifying the peak, for example, as shown in FIG. 4, the trace line 52 is smoothed by a smoothing filter, and the provisional peak 56 is specified on the smoothed trace line 54. In that case, for example, the difference method can be used. That is, the gradients are sequentially detected along the trace line 54, and the provisional peak 56 is specified as the time point at which the gradient polarity changes. Subsequently, a predetermined range 58 is set with reference to the provisional peak 56, and a peak on the trace line (original trace line) 52 is specified within the predetermined range 58. The predetermined range 58 is set, for example, the window width of the smoothing filter or based on the window width. Note that v'indicates the speed after smoothing.

In this way, by identifying the temporary peak 56 on the smoothed trace line 54 and searching for the peak 60 of the trace line 52 within a predetermined range 58 set with that as a reference, noise is mistakenly recognized as a peak. You can reduce the possibility of doing so. The peak 60 serves as a reference when processing the rising portion. It is also conceivable to use the tentative peak 56 as a reference when processing the rising portion.

In S12 in FIG. 3, the first representative point included in the rising portion on the front side of the peak is specified. The first representative points are the midpoint of the rising portion, the maximum gradient point, and others. For example, in the trace line 52 shown in FIG. 5, the first representative point 68 is specified at the rising portion 52A on the front side of the peak 60. For example, the maximum gradient point may be specified by using a difference method or the like, and may be used as the first representative point 68. The width 72 of the rising portion 52A may be specified, and the first representative point 68 may be determined based on the intermediate position of the width 72.

In S14 in FIG. 3, the first representative line representing the rising portion is calculated based on the first representative point. In the embodiment, the first representative line is an approximate line as a diagonal line. For example, in FIG. 5, the first representative line 70 is calculated as an approximate line (straight line) of the rising portion 52A, which is a line passing through the first representative point 68. In practice, the slope and intercept coordinates that define the first representative line 70 are calculated. In the trace line 52, the first representative line 70 may be calculated by the least squares method based on the coordinate sequence within a certain range centered on the first representative point 68. In that case, a certain range may be determined based on the width 72 of the rising portion 52A. For example, a numerical value obtained by dividing the width 72 by N may be set as a constant range. N is, for example, an integer of 2 or more. The least squares method may be applied over the entire rising portion 52A, whereby the first representative line 70 may be calculated.

In S16 in FIG. 3, a second representative point is specified as a point satisfying a predetermined condition in the bottom portion existing on the front side of the rising portion. As the second representative point, for example, the point closest to the baseline (recent contact point) is specified. For example, in FIG. 6, for the trace line 52, the search range 66 of the second representative point is defined with the peak 60 as a reference. Within the search range 66, the second representative point 78 is detected as the point closest to the baseline 76. The second representative point 78 is not set as the start time phase of the measurement section, but the second representative point 78 is used as a reference point for determining the second representative line as the horizontal line described below. The trace line 52 shown in FIG. 6 does not have the backflow portion described below.

In FIG. 7, when a part of the trace line 52 has a backflow portion 80 beyond the baseline 76, the trace line 52 crosses the baseline 76 and reaches the peak 60 in the search range 66. A close point is detected as the second representative point 82. Such a point is also the closest to the baseline. By modifying the method of determining the second representative point when the backflow portion 80 is generated in this way, it is possible to prevent the second representative point from being determined at an unexpectedly early point in time. The presence / absence of the backflow portion 80 may be determined and the processing may be switched according to the presence / absence of the backflow portion 80. You may do so.

In S18 in FIG. 3, the second representative line is calculated based on the second representative point. The second representative line is specified by the slope and the intercept coordinates. For example, as shown in FIG. 8, the horizontal line passing through the second representative point 78 is specified as the second representative line 84. As will be shown later, another line representing the bottom portion 62D may be defined as the second representative line. The second representative line as a horizontal line may be determined from the average flow velocity of the bottom portion, for example, without determining the second representative point.

In S20 in FIG. 3, the start time phase of the measurement section is specified based on the intersection of the first representative line and the second representative line calculated as described above. For example, in FIG. 8, the intersection 86 of the first representative line 70 as a diagonal line and the second representative line 84 as a horizontal line is specified, and the time phase at which the intersection 86 is located is set as the start time phase 88 of the measurement section. The intersection 86 will be located on the first representative line 70 that is steep with respect to the time axis, and the position of the intersection 86 on the time axis is less influenced by the position of the second representative point 78 on the time axis. do not have. That is, according to the embodiment, the intersection 86 is defined at or near the root of the rising portion 52A. Therefore, it is possible to appropriately set the start time phase 88 of the measurement section. In particular, it is possible to identify the starting phase 88 almost without being affected by the fluctuation of the bottom portion 62D.

FIG. 9 shows the trace line of the Doppler waveform 40 shown in FIG. 2 again. As a result of applying the Doppler waveform processing method according to the embodiment to the trace line, a plurality of start time phases 122, 124 for the plurality of measurement sections 126a, 126b, 126c have been specified. Specifically, in the trace line, the first peak 90 is specified, the first representative point 94 is specified for the rising portion 92A on the front side thereof, and the first representative line 96 is calculated based on the first representative point 94. On the other hand, for the bottom portion 98D on the front side of the rising portion 92A, the second representative point 100 is set, and the second representative line 102 is calculated based on the second representative point 100. Subsequently, the intersection 104 of the first representative line 96 and the second representative line 102 is specified, and the start time phase 122 is specified based on the intersection 104.

Similarly, in the trace line, the second peak 106 is specified, the first representative point 110 is specified for the rising portion 108A on the front side thereof, and the first representative line 112 is calculated based on the first representative point 110. On the other hand, for the bottom portion 114D on the front side of the rising portion 108A, the second representative point 116 is set, and the second representative line 118 is calculated based on the second representative point 116. Subsequently, the intersection 120 of the first representative line 112 and the second representative line 118 is specified, and the start time phase 124 is specified based on the intersection 120. The measurement section 126b is defined as a section between the start time phase 122 and the start time phase (end time phase) 124. Since the start time phase is set at or near the root of the rising portion in any measurement section, the possibility that the minimum flow velocity existing at the bottom portion deviates from each measurement section 126a, 126b, 126c is reduced. can.

FIG. 10 shows a modified example relating to the setting of the second representative line. In this modification, the reference range 138 is set with reference to the peak 60. The start phase 136 of the reference range 138 is defined as a point returning from the time phase 128 where the peak 60 is present by the first period 134, and similarly, the end phase 132 of the reference range 138 is when the peak 60 is present. It is defined as the point where the second period 130 is returned from the phase 128. The second representative line 140 is defined as an approximate straight line of the portion belonging to the reference range 138 in the trace line 52. In that case, for example, the least squares method can be used. Subsequently, similarly to the above, the intersection 142 of the first representative line 70 and the second representative line 140 is calculated, and the start time phase of the measurement section is specified based on the intersection 142.

According to the above embodiment, when the measurement section is determined, the start time phase can be objectively and stably determined. In particular, it is possible to appropriately determine the start time phase at or near the root of the rising portion without being significantly affected by the fluctuation existing in the bottom portion. In the above, the trace line of the Doppler waveform generated based on the PW Doppler method has been described, but the same processing as above shall be applied to the trace line of the Doppler waveform generated based on the CW Doppler method. Is possible. Doppler waveforms obtained from blood vessels other than the carotid artery or the heart may be processed.

21 Doppler waveform processing unit, 24 Doppler waveform forming unit, 26 trace unit, 28 measurement section setting unit, 30 measurement unit, 32 display processing unit.

Claims (5)

A first generation means for generating a rising portion representative line representing the rising portion based on the rising portion included in the trace line generated by tracing the Doppler waveform.
A second generation means for generating a bottom portion representative line which is a portion included in the trace line and represents a bottom portion generated on the front side of the rising portion.
A determination means for determining the time phase for specifying the measurement section based on the rising portion representative line and the bottom portion representative line , and
Including
The second generation means is
A means for identifying a second representative point representing the bottom portion,
As the bottom portion representative line, a means for calculating a horizontal line passing through the second representative point, and
Including
The means for identifying the second representative point is
When the bottom portion does not have a backflow portion that extends beyond the baseline and enters the opposite side, the point closest to the baseline is specified as the second representative point.
When the bottom portion has the backflow portion, a point on the baseline is specified as the second representative point.
A Doppler waveform processing device characterized by this. In the Doppler waveform processing apparatus according to claim 1,
When the bottom portion has the backflow portion, the means for specifying the second representative point specifies a point on the baseline that is closest to the peak of the rising portion as the second representative point. do,
A Doppler waveform processing device characterized by this. In the Doppler waveform processing apparatus according to claim 1 ,
The determination means is
A means for identifying the intersection of the rising portion representative line and the bottom portion representative line,
A means for determining the measurement section start time phase as the time phase for specifying the measurement section based on the intersection point,
A Doppler waveform processing device characterized by including. In the Doppler waveform processing apparatus according to claim 1,
The first generation means is
A means for identifying a first representative point representing the rising portion,
As the rising portion representative line, a means for calculating an approximate line of the rising portion, which is a line passing through the first representative point,
A Doppler waveform processing device characterized by including. A program for executing the Doppler waveform processing method in the Doppler waveform processing device.
Based on the rising part included in the trace line generated by the Doppler waveform trace, the first generation function that generates the rising part representative line representing the rising part, and
A second generation function that generates a bottom portion representative line that is included in the trace line and represents the bottom portion that occurs on the front side of the rising portion.
A determination function for determining the time phase for specifying the measurement section based on the rising portion representative line and the bottom portion representative line , and
Including
The second generation function is
The function to specify the second representative point representing the bottom portion and
As the bottom partial representative line, a function to calculate a horizontal line passing through the second representative point, and
Including
With the function to specify the second representative point,
When the bottom portion does not have a backflow portion that extends beyond the baseline and enters the opposite side, the point closest to the baseline is identified as the second representative point.
When the bottom portion has the backflow portion, a point on the baseline is identified as the second representative point.
A program characterized by that.

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