JP7449773B2 - Ultrasonic diagnostic equipment and transmission method - Google Patents

Description

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

Ultrasonic diagnostic apparatuses generally have multiple operation modes (transmission/reception modes). Among them are continuous wave Doppler mode (CW Doppler mode) and pulsed Doppler mode (PW Doppler mode). In the CW Doppler mode, continuous wave transmission to the subject (living body) and reception of reflected waves from within the subject are simultaneously performed. On the other hand, in the PW Doppler mode, transmission of pulse waves to the subject and reception of reflected waves from within the subject are alternately performed.

In both the CW Doppler mode and the PW Doppler mode, a spectrum indicating the blood flow velocity distribution is generated by frequency-analyzing 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 velocity range is limited by the pulse repetition frequency (PRF). In contrast, the CW Doppler method has no such limitations. CW Doppler mode is suitable for observing high-speed blood flow. For example, in cardiac ultrasound examinations, high-speed blood flow (forward flow) caused by valve stenosis and regurgitation caused by valve regurgitation are observed using the 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 compared to when executing the PW Doppler mode. The temperature of the probe's transmitting/receiving surface tends to rise. When the temperature of the transmitting/receiving wave surface reaches a specified temperature, the transmitting power is forcibly limited.

Patent Document 1 describes that heat generating parts are distributed by rotating the position of the transmission aperture 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 in accordance with body movement by changing the ultrasound beam direction in synchronization with the heartbeat. However, neither Patent Document 1 nor Patent Document 2 describes transmission power control synchronized with heartbeat. Note 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 Doppler mode.

Japanese Patent Application Publication No. 2006-223612 Japanese Patent Application Publication No. 2015-119917 Japanese Patent Application Publication No. 2010-005322

In Doppler mode, especially CW Doppler mode, it is required to observe blood flow of interest with high sensitivity, and it is also required to reduce the amount of heat generated by the probe.

An object of the present disclosure is to observe blood flow of interest with high sensitivity while suppressing the amount of heat generated by the probe in Doppler mode.

The ultrasound diagnostic apparatus according to the present disclosure includes a period setting section that sets a main observation period and a sub-observation period within each heartbeat period based on a signal representing a heartbeat in Doppler mode; A transmission control unit that causes the ultrasonic waves to be transmitted with a transmission power, and causes the ultrasonic waves to be transmitted with a second transmission power that is weaker than the first transmission power within the sub-observation period. shall be.

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

According to the present disclosure, in Doppler mode, blood flow of interest can be observed with high sensitivity while suppressing the amount of heat generated by the probe.

FIG. 1 is a block diagram showing an ultrasonic diagnostic apparatus according to an embodiment. FIG. 2 is a block diagram showing the functions of a transmission/reception control section. It is a figure showing the main observation period specified from the combination of attention valve and attention flow. It is a figure which shows the 1st example of a display. It is a figure which shows the 2nd example of a display. It is a figure which shows the 3rd example of a display. It is a flowchart which shows an example of operation. It is a block diagram showing a modification.

Hereinafter, embodiments will be described based on the drawings.

(1) Overview of Embodiment The ultrasonic diagnostic apparatus according to the embodiment includes a period setting section and a transmission control section. The period setting section sets a main observation period and a sub-observation period within each heartbeat period based on a signal representing a heartbeat in Doppler mode. The transmission control unit causes the ultrasound to be transmitted at a first transmission power within the main observation period, and transmits the ultrasound at a second transmission power that is weaker than the first transmission power during the sub-observation period. .

According to the above configuration, in each heartbeat period, ultrasound is transmitted with a relatively large first transmission power within the main observation period, while ultrasound is transmitted with a relatively small second transmission power within the sub-observation period. Sent. Thereby, the flow of interest (blood flow of interest) occurring within the main observation period can be observed with high sensitivity. At the same time, the amount of heat generated by the probe can be suppressed by reducing the total amount of transmitted power per heartbeat period.

Examples of signals representing heartbeats include electrocardiographic signals, received signals, ultrasound images, Doppler waveforms, and the like. By referring to electrocardiographic signals, individual heartbeat cycles can be identified relatively easily. The conditions that define the main observation period and the sub-observation period are specified directly or indirectly by the inspector, or are automatically set. For example, a certain period from the reference time phase may be regarded as the diastole phase, and the rest may be regarded as the systole period, and on this premise, the diastole phase or the systole phase may be determined as the main observation period. The Doppler waveform may be referenced over a certain period of time to determine an average ratio of diastole to systole, and based on this, the diastole and systole in each heartbeat cycle may be estimated. It is not necessary that the diastole or systole of the heart completely coincide with the main observation period. It is desirable to set the main observation period so that the flow of interest (particularly the observed portion of the flow of interest) is included within the main observation period.

The transmission power can be controlled by varying the transmission voltage, the transmission aperture size, the number of driven transmission elements, and the like. A third observation period other than the main observation period and the sub-observation period may be set within one heartbeat period. 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 continuous wave Doppler mode, but may also be applied to other Doppler modes.

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

The ultrasonic diagnostic apparatus according to the embodiment includes an input unit for an examiner to specify a valve of interest and the flow of interest. The period setting unit sets a main observation period and a sub-observation period based on the specified valve of interest and flow of interest. In embodiments, the valve of interest is selected from among multiple valves within the heart. The flow of interest is selected from reverse flow and forward flow.

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

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

The ultrasound diagnostic apparatus according to the embodiment includes a Doppler waveform generation section and an auxiliary image generation section. The Doppler waveform generator generates a Doppler waveform based on a received signal obtained by receiving a reflected wave from the heart. The auxiliary image generation unit generates auxiliary images 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, through observation of the auxiliary image, the period during which transmission is performed using the first transmission power, that is, the main observation period, and the period during which transmission is performed using the second transmission power, that is, the sub-observation period are inspected. This makes it possible to identify individuals. Through observation of the auxiliary images, it can be confirmed that the attention flow occurs 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 continuous wave Doppler mode, a main observation period and a sub-observation period are set within each heartbeat period based on a signal representing a heartbeat. In the transmission control step, continuous waves are transmitted to the heart at a first transmission power within the main observation period, and continuous waves are transmitted to the heart at a second transmission power weaker than the first transmission power during the sub-observation period. be done.

(2) Details of the embodiment FIG. 1 shows an ultrasonic diagnostic apparatus according to the embodiment. An ultrasound diagnostic apparatus is a medical device that forms ultrasound images by transmitting ultrasound toward a subject (living body) and receiving reflected waves from within the subject. The ultrasonic diagnostic apparatus according to the embodiment has operation modes such as a B mode for displaying tomographic images and a continuous wave (CW) Doppler mode for displaying Doppler waveforms.

The probe 10 is a portable transducer. The wave transmitting/receiving surface (specifically, the acoustic lens surface) of the probe 10 is brought 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 transducer array consisting of a plurality of transducer elements arranged one-dimensionally. An ultrasonic beam 12 is formed by the vibrating element array.

When B mode is selected, the ultrasound beam 12 is electronically scanned. As a result, a scanning plane 14 is formed as a two-dimensional data acquisition area. The scanning plane 14 has a coordinate system defined by a depth direction r and a scanning direction θ. As electronic scanning methods, electronic linear scanning methods, electronic sector scanning methods, etc. are known.

In the B mode, during transmission, a plurality of transmission signals are supplied from the transmission circuit 20 to the vibrating element array, thereby forming a transmission beam. During reception, reflected waves from within the subject are received by the transducer array, and a plurality of received signals generated thereby are sent to the receiving circuit 22. The receiving circuit 22 performs phasing addition (delayed addition) on a plurality of received signals, thereby generating beam data corresponding to a received beam.

Note that a plurality of beam data are generated by one electronic scan, and the received frame data is composed of the beam data. 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 section 24. Note that the ultrasonic beam 12 is conceptualized as a total transmitting and receiving beam.

In the CW Doppler mode, continuous waves are transmitted using the first transducer group (transmission aperture) in the transducer array, and continuous waves from within the body are transmitted using the second transducer group (reception aperture) in the transducer array. (reflected wave) is received. That is, the first transducer element group continuously forms a transmission beam, and at the same time, the second transducer element group continuously forms a reception beam. At that time, a transmission focus and a reception focus are set on the sample volume 18 specified by the inspector. The transmit and receive beams cross at sample volume 18 .

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

When it is desired to observe a flow of interest (e.g., high-speed regurgitation due to valve regurgitation) exiting from a valve of interest (e.g., the mitral valve) in the heart, B mode is first selected, and the sample volume 18 is placed at or near the valve of interest on the tomographic image. is set. Thereafter, the CW Doppler mode is selected and the Doppler waveform is observed. The Doppler waveform includes a waveform portion corresponding to the flow of interest. For example, the maximum flow velocity is determined from the peak of the waveform portion. CFM (color flow mapping) mode may be selected instead of B mode. In the CFM mode, an image in which a color two-dimensional blood flow image is synthesized on a black and white tomographic image is displayed.

It is also possible to provide a 2D vibrating element array within the probe 10. In that case, a three-dimensional data acquisition space is created by two-dimensional electronic scanning of the ultrasound beam. Volume data is obtained from that space. Even when using a 2D vibrating element array, it is possible to perform CW Doppler mode. In that case, the need for measures against heat generation in the probe 10 increases.

In the illustrated configuration example, the operations of the transmitter circuit 20 and the receiver circuit 22 are controlled by a transmitter/receiver controller 48 within the main controller 44 . The transmission/reception control unit 48 has a function of switching the transmission power in synchronization with the heartbeat cycle in CW Doppler mode, as will be described in detail later.

A beam data processing circuit is provided between the receiving circuit 22 and the tomographic image forming section 24, but its illustration 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. Each display frame data constituting the display frame data string corresponds to a tomographic image. A moving image is constructed from a plurality of tomographic images. The tomographic image forming section 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. A display frame data string is sent to the display processing section 26.

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

The two wall motion filters 34A and 34B function as low-cut filters or high-pass filters. A large unnecessary component (low-frequency noise or clutter that is a cardiac wall motion component) included 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 generates 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 spectra 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 makes up the Doppler waveform. The tracing unit 40 executes a process of tracing Doppler waveforms.

The configuration from the orthogonal detection section 30 to the tracing section 40 corresponds to the Doppler processing section 28. The Doppler processing unit 28 includes a processor that executes each of the processes described above. The tomographic image forming section 24 and the display processing section 26 may also each be configured by a processor. Some processes within the Doppler processing unit 28 may be executed by the CPU, which will be 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, electrocardiographic waveforms, auxiliary images, 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, or the like.

The main control unit 44 controls the operations of each component shown in FIG. An electrocardiograph (ECG) 46 is connected to the main control section 44 . The electrocardiograph 46 includes a plurality of electrodes that are attached to the subject. Electrocardiographic signals generated by the electrocardiograph 46 are sent to the main control unit 44 via a signal processing circuit (not shown).

An operation panel 55 is connected to the main control section 44 . The operation panel 55 is an input device that includes a trackball, multiple switches, multiple buttons, and the like. An operation mode is selected by the examiner using the operation panel 55. Further, at the start of execution of the CW Doppler mode, the examiner uses the operation panel 55 to specify the valve of interest and the flow of interest.

Specifically, the main control unit 44 is composed of a CPU that executes a program. In FIG. 1, a plurality of main functions of the main control section 44 are expressed by a plurality of blocks, and specifically, a transmission/reception control section 48 and a generation section 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 a main observation period and a sub-observation period for each heartbeat period based on the electrocardiogram signal, specifically, based on the R wave included in the electrocardiogram signal. . The main observation period is a period in which continuous waves are transmitted with normal transmission power (first transmission power), and the sub-observation period is a period in which continuous waves are transmitted with reduced transmission power (second transmission power). It is.

If the attention flow occurs during the diastole, the diastole is the main observation period. If the attention flow occurs during the systolic period, the systolic period is taken as the main observation period. It is not necessary that the main observation period completely coincides with the diastole or systole, but the main observation period should include the time or period of occurrence of the waveform part that is actually the target of measurement in the flow of interest. A main observation period and a sub-observation period are set. Flows of interest are, for example, high-velocity forward flow caused by valve stenosis and high-velocity backward flow caused by valve insufficiency. Usually, the maximum velocity in these abnormal flows is measured based on the Doppler waveform.

When the first transmission power is 100%, the second transmission power is set to 50%, for example. 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 in which the transmission power is continuously changed may be provided between the main observation period and the sub-observation period.

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 representing the main observation period and the sub-observation period. These image data are sent from the main control section 44 to the display processing section 26. Note that 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 each heartbeat cycle.

In FIG. 2, a plurality of functions performed by the transmission/reception control section 48 are expressed by a plurality of blocks. In the illustrated configuration example, a valve of interest 51 and a flow of interest 52 are designated by the inspector. A main observation period and a 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 designated by the inspector. For example, a certain period from the R wave may be defined as the main observation period. The remaining period will be the sub-observation period. The average ratio of the diastole or systole may be determined based on past heartbeat cycles, 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. During the main observation period 60, normal transmission power (first transmission power) 64 is set. On the other hand, in the sub-observation period 62, a reduced transmission power (second transmission power) 66 is set. Actually, a control signal 68 specifying the transmission power is generated in the transmission/reception control section 48, and the control signal 68 is sent to the transmission circuit. Note that the electrocardiographic signal is sent to a generation unit to generate an electrocardiographic signal waveform (see reference numeral 56A).

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

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

For example, according to the table 70 shown in FIG. 3, the systole or diastole is determined as the main observation period. Reference numeral 72 indicates a plurality of valves that can be selected by the examiner. Specifically, a particular valve among the tricuspid valve (T), mitral valve (M), aortic valve (A), and pulmonic valve (P) may be selected as the valve of interest. Further, reference numeral 74 indicates a plurality of blood flows that can be selected by the examiner. Specifically, reflux that may occur during systole (R) and forward flow that may occur during diastole (S) may be selected. In cases of valvular insufficiency, rapid regurgitation can occur during systole. In the case of valve stenosis, a high rate of forward flow (excessive forward flow) can occur during diastole.

Each cell 76 indicates the systole or diastole to be set as the main observation period for each combination of the valve of interest and the flow of interest. In this way, the main observation period is determined from the combination of the attention valve and attention flow specified by the inspector. Note that although the direction of the flow relative to the probe may be reversed depending on the method of contacting the probe, the period during which the flow of interest occurs remains unchanged.

4 to 6 show first to third display examples. 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 regurgitation is the flow of interest. In the case of this combination, the flow of interest occurs during the systolic phase, so the systolic flow is the main observation period. The horizontal axis of the Doppler waveform 80 is the time axis, and the vertical axis is the frequency axis (velocity axis). When the baseline 82 indicates a velocity of 0, the waveform portion above the baseline 82 corresponds to a flow approaching the probe, and the waveform portion below the baseline 82 corresponds to a flow moving 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 R waves 86 separate a plurality of heartbeat cycles. As described above, the systolic periods 88A, 88B, and 88C are each determined as the main observation period. For example, the period from time t1 of R wave generation to time t2 after a predetermined period of time is considered to be the systolic period. The period remaining after the systole is considered the diastole or sub-observation period. Each main observation period includes a waveform portion 80A corresponding to a backflow, and particularly a peak 80B corresponding to the highest 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, for example, by a solid line 92, and the sub-observation period is represented, for example, by a broken line 94. The main observation period and the sub-observation period may be expressed in different hues. Other identification methods may also be employed.

Incidentally, the Doppler waveform grows over 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. 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, an attention flow occurs during the diastole, and the diastole is determined as the main observation period. In the illustrated example, the portion below the baseline 82 corresponds to forward flow, and the portion above baseline 82 corresponds to reverse flow.

An electrocardiographic signal waveform 84 is displayed below the Doppler waveform 100, and an auxiliary image 90 is displayed below it. Each heartbeat cycle is defined based on each R-wave 86. A time point t4 after a certain period of time has elapsed from the R wave generation time point t3 is the start time of the diastole period. The period from time t4 to time t5 after a certain period of time is the diastolic phase. Diastole periods 104A and 104B are identified in each heartbeat cycle, and each is defined as a main observation period. In each heartbeat cycle, systolic periods 102A and 102B are sub-observation periods. For example, the main observation period includes a waveform portion 100A corresponding to a backflow, and particularly includes a peak 100B.

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

An example of operation is shown in FIG. In S8, the examiner specifies the valve of interest and the flow of interest. These specifications are accepted by the transmission/reception control unit. The transmission/reception control unit specifies the systole or diastole as the main observation period based on the combination of the valve of interest and the flow of interest. In S10, execution of 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, 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, execution of the CW Doppler mode is started. In S16, a main observation period and a sub-observation period are set based on the electrocardiogram signal. Continuous waves are transmitted with the first transmission power during the main observation period, and continuous waves are transmitted with the second transmission power during the sub-observation period. If it is determined in S18 that a freeze operation has been performed, in the illustrated operation example, the maximum speed of the attention flow is measured in S20.

A modification is shown in FIG. In FIG. 8, the same components as those shown in FIG.

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

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

The determination unit 112 determines the possibility of an error in the setting of the main observation period, that is, the possibility of an incorrect 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 performs control so that an 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, when the highest flow velocity occurs during the sub-observation period in which the second transmission power is set, an alert is displayed to the inspector. Such notification allows the inspector to correct incorrect designations. For example, one or both of the attention valve and attention flow may be 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, the tomographic image analysis unit 114 is configured by a machine learning type image estimator. The tomographic image analysis unit 114 eliminates the need for the examiner to specify the valve of interest. Note that the Doppler waveform analysis unit 110 may identify each heartbeat cycle based on the Doppler waveform. In that case, it becomes unnecessary 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 amount of heat generated by the probe can be suppressed. Since the transmission power can be maintained or increased during the main observation period, the flow of interest can be observed with high sensitivity. The above control may be applied to PW Doppler mode.

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

Claims (8)

In Doppler mode, 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;
Transmission control that causes the ultrasound to be transmitted with a first transmission power within the main observation period, and transmits the ultrasound with a second transmission power that is weaker than the first transmission power within the sub-observation period. Department and
including;
The period setting unit sets the main observation period and the sub-observation period within each heartbeat period according to the combination of attention valve and attention flow specified by the examiner.
An ultrasonic diagnostic device characterized by: The ultrasonic diagnostic apparatus according to claim 1,
The period setting unit sets one of the diastole and the systole as the main observation period, and sets the other of the diastole and the systole as the sub-observation period.
An ultrasonic diagnostic device characterized by: The ultrasonic diagnostic apparatus according to claim 1,
a table having a plurality of cells corresponding to a plurality of combinations defined by a plurality of valves in the heart and regurgitation and forward flow occurring in the heart;
Each cell has information specifying the main observation period,
The period setting unit sets the main observation period and the sub-observation period within each heartbeat period by referring to the table.
An ultrasonic diagnostic device characterized by: The ultrasonic diagnostic apparatus according to claim 1 ,
an input unit for the inspector to specify the attention valve and the attention flow ;
An ultrasonic diagnostic device characterized by: The ultrasonic diagnostic apparatus according to claim 1 ,
the valve of interest is selected from a plurality of valves in the heart ,
the flow of interest is selected from reverse flow and forward flow;
An ultrasonic diagnostic device characterized by: The ultrasonic diagnostic apparatus according to claim 1,
an input section for directly or indirectly specifying the main observation period by an inspector;
a Doppler waveform generation unit that generates a Doppler waveform based on a received signal obtained by receiving reflected waves from within the living body;
a determination unit that determines the possibility of incorrect designation of the main observation period by the examiner based on the Doppler waveform;
a notification unit that notifies the inspector of the possibility of erroneous designation when the possibility of erroneous designation is determined;
An ultrasonic diagnostic device comprising: The ultrasonic diagnostic apparatus according to claim 1,
a Doppler waveform generation unit that generates a Doppler waveform based on a received signal obtained by receiving reflected waves from the heart;
an auxiliary image generation unit that generates auxiliary images 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: In continuous wave Doppler mode, setting a main observation period and a sub-observation period within each heartbeat period based on a signal representing a heartbeat;
Continuous waves are transmitted to the heart at a first transmission power within the main observation period, and continuous waves are transmitted to the heart at a second transmission power weaker than the first transmission power during the sub-observation period. causing the waves to be transmitted;
including;
The main observation period and the sub-observation period are set within each heartbeat period according to the combination of attention valve and attention flow specified by the examiner.
A transmission method characterized by:

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