JP2021178007A - Ultrasonic diagnostic device and transmission method - Google Patents

Abstract

To observe a blood flow of interest with high sensitivity, while suppressing a calorific value in a probe, in a continuous wave Doppler mode.SOLUTION: In a continuous wave Doppler mode, a main observation period and a sub-observation period are set in each heart rate period based on a signal showing the heartbeat of a heart. In the main observation period, a continuous wave is transmitted at a first transmission power. In the sub-observation period, a continuous wave is transmitted at a second transmission power weaker than the first transmission power.SELECTED DRAWING: Figure 1

Description

The present invention relates to an ultrasonic diagnostic apparatus and a transmission method, and more particularly to transmission control in Doppler mode.

The ultrasonic diagnostic apparatus generally includes a plurality of operation modes (transmission / reception modes). Among them are continuous wave Doppler mode (CW Doppler mode) and pulse Doppler mode (PW Doppler mode). In the CW Doppler mode, the transmission of continuous waves to the subject (living body) and the reception of reflected waves from within the subject are executed at the same time. On the other hand, in the PW Doppler mode, the transmission of the pulse wave to the subject and the reception of the reflected wave from the inside of the subject are alternately executed.

In both the CW Doppler mode and the PW Doppler mode, a spectrum showing the blood flow velocity distribution is generated by frequency analysis of the Doppler information included in the received signal. A Doppler waveform is generated from the spectrum obtained at each time.

In PW Doppler mode, the upper limit of the measurable speed range is limited by the pulse repetition frequency (PRF). On the other hand, the CW Doppler method has no such limitation. CW Doppler mode is suitable for observing high-speed blood flow. For example, in echocardiography of the heart, high-speed blood flow (forward flow) caused by valve stenosis and regurgitation caused by valve insufficiency are observed using CW Doppler mode. On the other hand, in the CW Doppler mode, since continuous waves are transmitted, a large amount of heat is generated in the probe as compared with the execution of the PW Doppler mode. The temperature of the wavefront of the probe tends to rise. When the temperature of the wavefront reaches the specified temperature, the transmission power is forcibly limited.

Patent Document 1 describes that the heat generation site is dispersed by rotating the position of the transmission opening during execution of the CW Doppler mode. Patent Document 2 describes that, during execution of the CW Doppler mode, the sample volume position is changed according to the body movement by changing the ultrasonic beam direction in synchronization with the heartbeat. However, neither Patent Document 1 nor Patent Document 2 describes transmission power control synchronized with the heartbeat. It should be noted that Patent Document 3 describes switching the transmission power in synchronization with a biological signal when acquiring volume data, but does not describe transmission power control in the Doppler mode.

Japanese Unexamined Patent Publication No. 2006-223612 JP-A-2015-119917 Japanese Unexamined Patent Publication No. 2010-005322

In the Doppler mode, particularly the CW Doppler mode, it is required to observe the blood flow of interest with high sensitivity, and it is required to reduce the calorific value of the probe.

An object of the present disclosure is to observe the blood flow of interest with high sensitivity in the Doppler mode while suppressing the calorific value of the probe.

In the Doppler mode, the ultrasonic diagnostic apparatus according to the present disclosure includes a period setting unit that sets a main observation period and a sub-observation period within each heartbeat period based on a signal representing a heartbeat, and a first unit within the main observation period. It is characterized by including a transmission control unit for transmitting ultrasonic waves with transmission power and transmitting ultrasonic waves with a second transmission power weaker than the first transmission power within the sub-observation period. And.

The transmission method according to the present disclosure is a step of setting a main observation period and a sub-observation period within each heartbeat period based on a signal representing the heartbeat in the continuous wave Doppler mode, and the heart within the main observation period. The continuous wave is transmitted to the heart with the first transmission power, and the continuous wave is transmitted to the heart with the second transmission power weaker than the first transmission power within the sub-observation period. It is characterized by including a process.

According to the present disclosure, in the Doppler mode, the blood flow of interest can be observed with high sensitivity while suppressing the calorific value of the probe.

It is a block diagram which shows the ultrasonic diagnostic apparatus which concerns on embodiment. It is a block diagram which shows the function of a transmission / reception control part. It is a figure which shows the main observation period specified from the combination of attention valve and attention flow. It is a figure which shows the 1st display example. It is a figure which shows the 2nd display example. It is a figure which shows the 3rd display example. It is a flowchart which shows the operation example. It is a block diagram which shows the modification.

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

(1) Outline of Embodiment The ultrasonic diagnostic apparatus according to the embodiment includes a period setting unit and a transmission control unit. In the Doppler mode, the period setting unit sets the main observation period and the sub-observation period within each heartbeat period based on the signal representing the heartbeat. The transmission control unit makes sure that the ultrasonic wave is transmitted at the first transmission power within the main observation period, and the ultrasonic wave is transmitted at the second transmission power weaker than the first transmission power within the sub-observation period. ..

According to the above configuration, in each heartbeat period, ultrasonic waves are transmitted with a relatively large first transmission power during the main observation period, while ultrasonic waves are transmitted with a relatively small second transmission power during the sub-observation period. Will be sent. As a result, the flow of interest (blood flow of interest) generated during the main observation period can be observed with high sensitivity. At the same time, the total amount of transmission power per heartbeat period can be reduced to suppress the calorific value of the probe.

Examples of the signal representing the heartbeat include an electrocardiographic signal, a received signal, an ultrasonic image, a Doppler waveform, and the like. By referring to the electrocardiographic signal, individual heartbeat cycles can be identified relatively easily. The conditions that determine the main observation period and the sub-observation period are directly or indirectly specified by the inspector, or are automatically set. For example, a certain period of time from the reference time phase may be regarded as a diastole, the other period may be regarded as a systole, and the diastole or the systole may be defined as the main observation period under that premise. The Doppler waveform may be referenced over a period of time to identify the average ratio of diastole to systole, based on which the diastole and systole may be estimated. The diastole or systole of the heart does not have to exactly coincide with the main observation period. It is desirable to set the main observation period so that the attention flow (especially the observation part in the attention flow) is included in the main observation period.

The transmission power can be controlled by changing the transmission voltage, the transmission aperture size, the number of transmission elements to be driven, and the like. Within one heartbeat period, a third observation period other than the main observation period and the sub-observation period may be set. For example, a transition period may be set between the main observation period and the sub-observation period in which the transmission power is continuously changed. The above configuration is particularly useful in the continuous wave Doppler mode, but can also be applied to other Doppler modes.

In the embodiment, the period setting unit sets the main observation period for the diastole when the attention flow in the heart occurs within the diastole of the heart. On the other hand, the period setting unit sets the main observation period for the systole when the attention flow occurs within the systole of the heart. In the embodiment, the main observation period is the period corresponding to the attention flow coming out of the attention valve in the heart. The sub-observation period is a period other than the main observation period.

The ultrasonic diagnostic apparatus according to the embodiment includes a attention valve and an input unit for designating the attention flow by the inspector. The period setting unit sets the main observation period and the sub-observation period based on the designation of the attention valve and the attention flow. In embodiments, the valve of interest is selected from among a plurality of valves in the heart. The flow of interest is selected from backflow and forward flow.

The ultrasonic diagnostic apparatus according to the embodiment includes an input unit, a Doppler waveform generation unit, a determination unit, and a notification unit. The input unit is for the inspector to directly or indirectly specify the main observation period. The Doppler waveform generator generates a Doppler waveform based on the received signal obtained by receiving the reflected wave from the living body. The determination unit determines the possibility of erroneous designation of the main observation period by the inspector based on the Doppler waveform. When the possibility of erroneous designation is determined, the notification unit notifies the inspector of the possibility of erroneous designation.

According to the above configuration, when the possibility of erroneous designation is recognized, the possibility can be notified to the inspector. For example, when the occurrence timing of the maximum flow velocity (that is, the peak in the attention flow) is not within the main observation period but within the sub-observation period, the possibility of erroneous designation is notified.

The ultrasonic diagnostic apparatus according to the embodiment includes a Doppler waveform generation unit and an auxiliary image generation unit. The Doppler waveform generator generates a Doppler waveform based on the received signal obtained by receiving the reflected wave from the heart. The auxiliary image generation unit generates an auxiliary image representing the main observation period and the sub-observation period. An auxiliary image is displayed along with the Doppler waveform.

According to the above configuration, the period during which transmission is performed with the first transmission power, that is, the main observation period, and the period during which transmission is performed with the second transmission power, that is, the sub-observation period, are inspected through the observation of the auxiliary image. It becomes possible for a person to identify. Through the observation of the auxiliary image, it can be confirmed that the attention flow is occurring within the main observation period.

The transmission method according to the present invention includes a setting step and a transmission control step. In the setting step, in the continuous wave Doppler mode, the main observation period and the sub-observation period are set within each heartbeat period based on the signal representing the heartbeat of the heart. In the transmission control step, a continuous wave is transmitted to the heart with the first transmission power during the main observation period, and a continuous wave is transmitted to the heart with a second transmission power weaker than the first transmission power during the sub-observation period. Will be done.

(2) Details of the Embodiment FIG. 1 shows an ultrasonic diagnostic apparatus according to the embodiment. The ultrasonic diagnostic apparatus is a medical apparatus that forms an ultrasonic image by transmitting ultrasonic waves toward a subject (living body) and receiving reflected waves from the inside of the subject. The ultrasonic diagnostic apparatus according to the embodiment includes an operation mode such as a B mode for displaying a tomographic image and a continuous wave (CW) Doppler mode for displaying a Doppler waveform.

The probe 10 is a portable transmitter / receiver. The wave front (specifically, the surface of the acoustic lens) of the probe 10 comes into contact with the surface of the subject (the chest surface in the case of a cardiac examination). In the illustrated configuration, the 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.

When the B mode is selected, the ultrasonic beam 12 is electronically scanned. As a result, the scanning surface 14 as a two-dimensional data acquisition region is formed. The scanning surface 14 has a coordinate system defined by the depth direction r and the scanning direction θ. As the electronic scanning method, an electronic linear scanning method, an electronic sector scanning method, and the like are known.

In the B mode, at the time of transmission, a plurality of transmission signals are supplied from the transmission circuit 20 to the vibrating element array, whereby a transmission beam is formed. At the time of reception, the reflected wave from the subject is received by the vibrating element array, and a plurality of received signals generated thereby are sent to the receiving circuit 22. In the reception circuit 22, phasing addition (delay addition) is executed for a plurality of received signals, whereby beam data corresponding to the received beam is generated.

It should be noted that a plurality of beam data are generated by one electron scan, and the received frame data is composed of them. Each beam data is composed of a plurality of echo data arranged in the depth direction. A plurality of received frame data are output from the receiving circuit 22 to the tomographic image forming unit 24. The ultrasonic beam 12 is conceived as a total transmission / reception beam.

In the CW Doppler mode, a continuous wave is transmitted using the first vibrating element group (transmission opening) in the vibrating element array, and a continuous wave from the living body is transmitted using the second vibrating element group (reception opening) in the vibrating element array. (Reflected wave) is received. That is, the transmission beam is continuously formed by the first vibrating element group, and at the same time, the receiving beam is continuously formed by the second vibrating element group. At that time, the transmission focus and the reception focus are set on the sample volume 18 designated by the inspector. The transmit beam and the receive beam cross at the sample volume 18.

In the CW Doppler mode, the transmission circuit 20 continues to supply a plurality of transmission signals to the first vibrating element group. The receiving circuit 22 continues to perform phasing addition for a plurality of received signals from the second vibrating element group. The received signal generated by this is sent to the Doppler processing unit 28.

If you want to observe the attention flow (eg, high-speed regurgitation due to valve insufficiency) coming out of the attention valve (eg, mitral valve) in the heart, B mode is selected first, and the sample volume 18 is selected on the tomographic image at or near the attention valve. Is set. After that, the CW Doppler mode is selected and the Doppler waveform is observed. The Doppler waveform includes a waveform portion corresponding to the current of interest. For example, the maximum flow velocity is specified from the peak of the waveform portion. The CFM (color flow mapping) mode may be selected instead of the B mode. In the CFM mode, a composite image of a color two-dimensional blood flow image is displayed on a black-and-white tomographic image.

It is also possible to provide a 2D vibrating element array in the probe 10. In that case, a three-dimensional data acquisition space is formed by two-dimensional electron scanning of the ultrasonic beam. Volume data is acquired from that space. Even when a 2D vibrating element array is used, it is possible to execute the CW Doppler mode. In that case, the need for measures against heat generation in the probe 10 increases.

In the illustrated configuration example, the operation of the transmission circuit 20 and the reception circuit 22 is controlled by the transmission / reception control unit 48 in the main control unit 44. As will be described in detail later, the transmission / reception control unit 48 has a function of switching the transmission power in synchronization with the heartbeat cycle in the CW Doppler mode.

A beam data processing circuit is provided between the receiving circuit 22 and the tomographic image forming unit 24, but the illustration thereof is omitted. The beam data processing circuit includes, for example, a detection circuit, a correlation circuit, a logarithmic conversion circuit, and the like.

The tomographic image forming unit 24 is a module that forms a display frame data string from a received frame data string. The individual display frame data constituting the display frame data string corresponds to a tomographic image. A moving image is composed of multiple tomographic images. The tomographic image forming unit 24 has a digital scan converter (DSC). The DSC has a coordinate conversion function, a pixel interpolation function, a frame rate conversion function, and the like. The display frame data string is sent to the display processing unit 26.

The Doppler processing unit 28 will be described. The orthogonal detection unit 30 is a circuit that performs orthogonal detection on a received signal. As a result, a complex signal (analog complex signal) composed of a real part signal and an imaginary part signal is generated. The complex signal is converted into a digital complex signal by the two A / D converters 32A and 32B. An A / D conversion unit may be provided in the receiving circuit 22.

The two wall motion filters 34A and 34B function as a low-cut filter, that is, a high-pass filter. A large unnecessary component (low frequency noise, that is, a clutter, which is a heart wall motion component) contained in the received signal is removed, and a blood flow component is extracted.

The FFT calculator 36 is a module that performs frequency analysis on the input digital complex signal. This produces a spectrum. The spectrum shows the power distribution on the blood flow velocity axis.

The Doppler waveform generation unit 38 generates a Doppler waveform based on the spectrum sequentially output from the FFT calculator 36. The horizontal axis of the Doppler waveform is the time axis, and the vertical axis of the Doppler waveform is the frequency axis, that is, the velocity axis. Power is expressed by the brightness of each pixel that constitutes the Doppler waveform. The trace unit 40 executes a process of tracing the Doppler waveform.

The configuration from the orthogonal detection unit 30 to the trace unit 40 corresponds to the Doppler processing unit 28. The Doppler processing unit 28 includes a processor that executes each of the above-mentioned processes. The tomographic image forming unit 24 and the display processing unit 26 can also be configured by the processor, respectively. Some processing in the Doppler processing unit 28 may be executed by the CPU described later.

The display processing unit 26 has an image composition function, a color calculation function, and the like. The display processing unit 26 forms an image to be displayed on the display 42. A tomographic image is displayed on the display 42 when the B mode is selected, and a Doppler waveform is displayed on the display 42 when the CW Doppler mode is selected. Along with the Doppler waveform, an electrocardiographic waveform, an auxiliary image, etc. are also displayed as described below. When the two-screen display format is selected, the frozen tomographic image and the Doppler waveform formed in real time are displayed side by side. The display 42 is composed of an LCD, an organic EL device, and the like.

The main control unit 44 controls the operation of each configuration shown in FIG. An electrocardiograph (ECG) 46 is connected to the main control unit 44. The electrocardiograph 46 includes a plurality of electrodes worn on the subject. The electrocardiographic signal generated by the electrocardiograph 46 is sent to the main control unit 44 via a signal processing circuit (not shown).

An operation panel 55 is connected to the main control unit 44. The operation panel 55 is an input device including a trackball, a plurality of switches, a plurality of buttons, and the like. The operation mode is selected by the inspector using the operation panel 55. Further, at the start of execution of the CW Doppler mode, the inspector designates the attention valve and the attention flow by using the operation panel 55.

Specifically, the main control unit 44 is composed of a CPU that executes a program. In FIG. 1, a plurality of main functions possessed by the main control unit 44 are represented by a plurality of blocks, and specifically, a transmission / reception control unit 48 and a generation unit 50 are shown.

The transmission / reception control unit 48 controls the operation of the transmission circuit 20 and the reception circuit 22. In the CW Doppler mode, the transmission / reception control unit 48 sets the main observation period and the sub-observation period for each heartbeat period based on the electrocardiographic signal, specifically, the R wave included in the electrocardiographic signal. .. The main observation period is the period during which continuous waves are transmitted with normal transmission power (first transmission power), and the sub-observation period is the period during which continuous waves are transmitted with reduced transmission power (second transmission power). Is.

When diastole occurs during the diastole, diastole is the main observation period. If the current of interest occurs during systole, systole is the main observation period. The main observation period does not have to completely coincide with the diastole or systole, so that the occurrence time or occurrence period of the waveform part to be actually measured in the current of interest is included in the main observation period. The main observation period and the sub-observation period are set. The flow of interest is, for example, a high-speed forward flow caused by valve stenosis and a high-speed regurgitation caused by valve insufficiency. Usually, the maximum velocity in those anomalous flows is measured based on the Doppler waveform.

When the first transmission power is 100%, the second transmission power is set to, for example, 50%. However, those ratios and individual powers can be set arbitrarily. For example, the second transmission power may be set to 25%. The first transmission power and the second transmission power may be automatically set based on the Doppler waveform. A transition period may be provided between the main observation period and the sub-observation period to continuously change the transmission power.

The generation unit 50 generates an electrocardiographic signal waveform and an auxiliary image to be displayed together with the Doppler waveform. All of them are display elements that make up a graphic image. The electrocardiographic signal waveform is generated from the electrocardiographic signal. The auxiliary image is a reference image showing the main observation period and the sub-observation period. The image data is sent from the main control unit 44 to the display processing unit 26. The main control unit 44 may generate the entire graphic image including the electrocardiographic signal waveform and the auxiliary image.

The display 42 displays a Doppler waveform, an electrocardiographic signal waveform, and an auxiliary image in the CW Doppler mode. Through the auxiliary images, the examiner can identify the main and sub-observation periods within the individual heartbeat cycle.

In FIG. 2, a plurality of functions exhibited by the transmission / reception control unit 48 are represented by a plurality of blocks. In the illustrated configuration example, the attention valve 51 and the attention flow 52 are designated by the inspector. The main observation period and the sub-observation period are automatically set according to the combination of the attention valve 51 and the attention flow 52 (see reference numeral 54). The main observation period may be directly specified by the inspector. For example, a certain period from the R wave may be defined as the main observation period. The remaining period is the sub-observation period. The average ratio of diastole or systole may be determined based on the past heartbeat cycle, and the diastole or systole may be determined as the main observation period based on the average ratio.

Each R wave included in the electrocardiographic signal 56 is detected (see reference numeral 58). The start timing of each heartbeat cycle is determined based on each R wave. One heartbeat cycle is between two adjacent R waves. In the main observation period 60, the normal transmission power (first transmission power) 64 is set. On the other hand, in the sub-observation period 62, the reduced transmission power (second transmission power) 66 is set. Actually, the transmission / reception control unit 48 generates a control signal 68 that specifies the transmission power, and the control signal 68 is transmitted to the transmission circuit. The electrocardiographic signal is sent to a generator to generate an electrocardiographic signal waveform (see reference numeral 56A).

Generally, the systolic time length is 0.3 to 0.4 sec and the diastolic time length is 0.6 to 0.7 sec. In consideration of this, 0.3 sec or 0.4 sec from the R wave may be regarded as a systole, and immediately after that to the next R wave may be regarded as a diastole. Specifically, when the main observation period is the systole, 0.4 sec from the R wave may be regarded as the systole. When the main observation period is diastole, 0.3 sec from the R wave may be regarded as systole. That is, the time length of the main observation period may be set longer. Diastole and systole may be determined automatically based on the electrocardiographic or Doppler waveform.

The transmission power can be switched by changing the transmission voltage, changing the transmission aperture, changing the number of vibrating elements to be driven, and the like. The reception gain may be increased in conjunction with the reduction of the transmission power.

For example, according to Table 70 shown in FIG. 3, systole or diastole is defined as the main observation period. Reference numeral 72 indicates a plurality of valves that can be selected by the inspector. Specifically, a specific valve among the tricuspid valve (T), sanghaal valve (M), aortic valve (A) and pulmonary valve (P) can be selected as the valve of interest. In addition, reference numeral 74 indicates a plurality of blood flows that can be selected by the examiner. Specifically, a backflow that can occur in systole (R) and a forward flow that can occur in diastole (S) can be selected. In the case of valve insufficiency, rapid regurgitation can occur during systole. In the case of valve stenosis, high-speed forward flow (excessive forward flow) can occur during diastole.

Each cell 76 indicates a systole or diastole that should be set as the main observation period for each combination of the valve of interest and the current of interest. In this way, the main observation period is determined by the combination of the attention valve and the attention flow specified by the inspector. Depending on the probe contact method, the direction of the flow with respect to the probe is reversed, but the generation period of the attention flow does not change.

4 to 6 show a first display example to a third display example. Each display example is for explaining the embodiment in an easy-to-understand manner, and does not necessarily match the actual Doppler waveform.

In the first display example shown in FIG. 4, the tricuspid valve is the valve of interest and the backflow is the flow of interest. In the case of the combination, the systolic flow is the main observation period because the systolic flow is generated. The horizontal axis of the Doppler waveform 80 is the time axis, and the vertical axis is the frequency axis (speed axis). When the baseline 82 shows a velocity of 0, the corrugated portion above the baseline 82 corresponds to the flow approaching the probe, and the corrugated portion below the baseline 82 corresponds to the flow away from the probe.

An electrocardiographic signal waveform 84 is shown below the Doppler waveform 80. The electrocardiographic signal waveform 84 includes an R wave 86 for each heartbeat cycle. A plurality of heartbeat cycles are divided by a plurality of R waves 86. As described above, the systoles 88A, 88B and 88C are defined as the main observation periods, respectively. For example, the systole is considered to be from the time point t1 at which the R wave is generated to the time point t2 after a predetermined time has elapsed. The residual period after systole is considered diastole or sub-observation period. Each main observation period includes a waveform portion 80A corresponding to backflow, and in particular a peak 80B corresponding to the maximum flow velocity.

An auxiliary image 90 is displayed below the electrocardiographic signal waveform 84. The auxiliary image 90 is an image showing a main observation period and a sub-observation period for each heartbeat cycle. In the illustrated example, the main observation period is represented by, for example, a solid line 92, and the sub-observation period is represented by, for example, a broken line 94. The main observation period and the sub observation period may be represented by different hues. Other identification methods may be adopted.

By the way, the Doppler waveform grows with the passage of time. Along with the Doppler waveform, the electrocardiographic signal waveform 84 and the auxiliary image 90 also grow over time.

In the second display example shown in FIG. 5, the same elements as those shown in FIG. 4 are designated by the same reference numerals, and the description thereof will be omitted. This also applies to FIG. 6 shown later.

In the second display example shown in FIG. 5, the valve of interest is the aortic valve, and the flow of interest is regurgitation. In the case of that combination, a current of interest occurs in the diastole, and the diastole is defined as the main observation period. In the illustrated example, the portion below the baseline 82 corresponds to the forward flow and the portion above the baseline 82 corresponds to the backflow.

The electrocardiographic signal waveform 84 is displayed below the Doppler waveform 100, and the auxiliary image 90 is displayed below it. Each heart rate cycle is defined based on each R wave 86. The time point t4 after a certain period of time has elapsed from the time point t3 at which the R wave is generated is defined as the start time point of the diastole. The diastole is from time point t4 to time point t5 after a certain period. Diastole 104A and 104B are specified in each heartbeat cycle, and each is set as the main observation period. The systoles 102A and 102B are set as sub-observation periods in each heartbeat cycle. For example, the waveform portion 100A corresponding to the backflow is included in the main observation period, and the peak 100B is particularly included.

In the third display example shown in FIG. 6, the tricuspid valve is the attention valve and the backflow is the attention flow, as in the case of the first display example. In the case of the combination, a current of interest occurs in the systole, and the systole is the main observation period. However, the direction in which the probe is applied is opposite between the first display example and the third display example. That is, in the third display example, the waveform portion above the baseline 82 corresponds to the backflow, and the waveform portion below the baseline 82 corresponds to the forward flow. For example, a waveform portion 106A corresponding to regurgitation is generated during the main observation period in systole 88C. In particular, the peak 106B occurs within that period.

FIG. 7 shows an operation example. In S8, the inspector designates the attention valve and the attention flow. Those designations are accepted by the transmission / reception control unit. In the transmission / reception control unit, a systole or diastole is designated as the main observation period based on the combination of the valve of interest and the flow of interest. In S10, the execution of the B mode is started, and the examiner adjusts the position and orientation of the probe so that the valve of interest appears on the tomographic image. In S10, the CFM mode may be selected. In S12, a freeze operation is performed, and a sample volume is set on the frozen tomographic image.

In S14, the execution of the CW Doppler mode is started. In S16, the main observation period and the sub-observation period are set based on the electrocardiographic signal. In the main observation period, the continuous wave is transmitted by the first transmission power, and in the sub-observation period, the continuous wave is transmitted by the second transmission power. When it is determined that the freeze operation has occurred in S18, the maximum speed of the attention flow is measured in S20 in the illustrated operation example.

FIG. 8 shows a modified example. In FIG. 8, the same components as those shown in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

In the modification shown in FIG. 8, the Doppler waveform analysis unit 110, the determination unit 112, and the tomographic image analysis unit 114 are added to the configuration shown in FIG.

The Doppler waveform analysis unit 110 analyzes, for example, whether the maximum blood flow occurs in the systole or the diastole by analyzing the Doppler waveform. For example, the identification can be performed by specifying the peak occurrence timing in each heartbeat period.

The determination unit 112 determines the possibility of an error in setting the main observation period, that is, the possibility of an erroneous designation by the user, based on the analysis result of the Doppler waveform analysis unit 110. When the possibility is determined, the determination unit 112 controls so that the alert is displayed on the display 42. The alert is information for notifying the inspector of the possibility of erroneous designation. The determination unit 112 functions as a notification unit.

With the above configuration, an alert is displayed to the inspector when the maximum flow velocity occurs in the sub-observation period in which the second transmission power is set. With such notification, the inspector can correct the erroneous designation. For example, one or both of the attention valve and the attention flow are corrected. The setting of the main observation period itself may be corrected.

The tomographic image analysis unit 114 identifies the valve of interest based on the frozen tomographic image. For example, a tomographic image analysis unit 114 is configured by a machine learning type image estimator. According to the tomographic image analysis unit 114, it is not necessary for the inspector to specify the valve of interest. The Doppler waveform analysis unit 110 may specify each heartbeat cycle based on the Doppler waveform. In that case, it is not necessary to specify the heartbeat cycle based on the electrocardiographic signal.

According to the above embodiment, since the transmission power can be reduced during the sub-observation period, the calorific value of the probe can be suppressed. Since the transmission power can be maintained or increased during the main observation period, the current of interest can be observed with high sensitivity. The above control may be applied to the PW Doppler mode.

10 probe, 24 tomographic image forming unit, 26 display processing unit, 28 Doppler processing unit, 39 Doppler waveform generation unit, 44 main control unit, 48 transmission / reception control unit, 50 generation unit.

Claims (8)

In the Doppler mode, a period setting unit that sets the main observation period and the sub-observation period within each heartbeat period based on the signal representing the heartbeat, and
Transmission control so that ultrasonic waves are transmitted with the first transmission power within the main observation period and ultrasonic waves are transmitted with a second transmission power weaker than the first transmission power within the sub-observation period. Department and
An ultrasonic diagnostic apparatus characterized by containing. In the ultrasonic diagnostic apparatus according to claim 1,
The period setting unit sets the main observation period for the diastole when the attention flow in the heart occurs in the diastole of the heart, and the attention flow occurs in the systole of the heart. In some cases, the main observation period is set for the systole.
An ultrasonic diagnostic device characterized by this. In the ultrasonic diagnostic apparatus according to claim 1,
The main observation period is a period corresponding to the attention flow emitted from the attention valve in the heart.
The sub-observation period is a period other than the main observation period.
An ultrasonic diagnostic device characterized by this. In the ultrasonic diagnostic apparatus according to claim 3,
Includes the attention valve and an input unit for designating the attention flow by the inspector.
The period setting unit sets the main observation period and the sub-observation period based on the designation of the attention valve and the attention flow.
An ultrasonic diagnostic device characterized by this. In the ultrasonic diagnostic apparatus according to claim 4,
The attention valve is selected from a plurality of valves in the heart.
The noteworthy flow is selected from backflow and forward flow.
An ultrasonic diagnostic device characterized by this. In the ultrasonic diagnostic apparatus according to claim 1,
An input unit for directly or indirectly designating the main observation period by the inspector,
A Doppler waveform generator that generates a Doppler waveform based on a received signal obtained by receiving a reflected wave from the living body, and a Doppler waveform generator.
Based on the Doppler waveform, a determination unit that determines the possibility of erroneous designation of the main observation period by the inspector, and
A notification unit that notifies the inspector of the possibility of erroneous designation when the possibility of erroneous designation is determined, and a notification unit.
An ultrasonic diagnostic apparatus characterized by containing. In the ultrasonic diagnostic apparatus according to claim 1,
A Doppler waveform generator that generates a Doppler waveform based on the received signal obtained by receiving the reflected wave from the heart,
An auxiliary image generation unit that generates an auxiliary image representing the main observation period and the sub-observation period,
Including
The auxiliary image is displayed together with the Doppler waveform.
An ultrasonic diagnostic device characterized by this. In the continuous wave Doppler mode, the process of setting the main observation period and the sub-observation period within each heartbeat period based on the signal representing the heartbeat, and
During the main observation period, a continuous wave is transmitted to the heart with the first transmission power, and during the sub-observation period, the continuous wave is continuously transmitted to the heart with a second transmission power weaker than the first transmission power. The process of getting the waves to be transmitted and
A transmission method characterized by including.

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