JP7601658B2 - Ultrasound diagnostic equipment - Google Patents

Description

The embodiments disclosed in this specification and the drawings relate to an ultrasound diagnostic device.

In an ultrasound diagnostic device, a transmission circuit applies a voltage to an ultrasound probe, causing the ultrasound probe to generate ultrasound waves. For example, the transmission circuit applies a voltage to the ultrasound probe by transmitting a drive signal to the ultrasound probe.

The transmission circuit also includes a transformer that transforms the voltage supplied by the power source. The transmission circuit applies the voltage transformed by the transformer to the ultrasonic probe. There are various types of transformers included in the transmission circuit. For example, there are various types of winding numbers of the primary coil (also called the primary winding or simply the primary side) and the secondary coil (also called the secondary winding or simply the secondary side) included in the transformer. If the number of windings is large, the scale (size) of the transformer itself tends to be large. When the ratio of the number of windings of the primary coil to the number of windings of the secondary coil is 1:1, the desired performance can be obtained by providing many switching circuits around the transformer. In such a case, the scale of the transformer itself is relatively small, but the scale of the switching circuits around the transformer is relatively large. As a result, the scale of the entire transmission circuit becomes relatively large.

Therefore, it is conceivable that the transformer has two windings as a primary coil and a center tap provided between the two windings, and has one winding as a secondary coil. In this case, the size of the switching circuit around the transformer becomes relatively small, and therefore the size of the entire transmission circuit becomes relatively small.

However, in such a transformer, electric charge may remain when the power supply is switched. For example, an ultrasound diagnostic device has various types of ultrasound transmission modes, and a power supply corresponding to each ultrasound transmission mode is used for each ultrasound transmission mode. In other words, the ultrasound diagnostic device switches the type of ultrasound to be transmitted by switching the power supply used. The ultrasound diagnostic device can generate various types of image data by switching the type of ultrasound to be transmitted.

For example, a case will be described in which an ultrasound diagnostic device displays a color image based on color image data showing blood flow information superimposed on a B-mode image based on B-mode image data in which the intensity of reflected waves is represented by brightness. In this case, when the ultrasound diagnostic device generates B-mode image data and color image data, the transmission circuit alternates between two power sources with different applied voltage magnitudes to alternately apply two voltages of different magnitudes to the ultrasound probe. When generating B-mode image data, the ultrasound diagnostic device applies a relatively high voltage to the ultrasound probe to collect reflected wave data that is the basis of the B-mode image data. Also, when generating color image data, the ultrasound diagnostic device applies a relatively low voltage to the ultrasound probe to collect reflected wave data that is the basis of the color image data.

Here, when generating color image data, the ultrasound diagnostic device transmits ultrasound waves multiple times to correlate multiple reflected wave data. Therefore, it is preferable that the waveforms of multiple voltages (waveforms of drive signals) corresponding to the multiple ultrasound waves transmitted when generating color image data and the waveforms of multiple voltages applied to the ultrasound probe are the same. Here, when switching from an ultrasound transmission mode for generating B-mode image data to an ultrasound transmission mode for generating color image data, the ultrasound diagnostic device switches from a relatively high voltage power supply to a relatively low voltage power supply. In this case, when switching from a relatively high voltage power supply to a relatively low voltage power supply, a charge may remain in the transformer. For this reason, among the waveforms of multiple cycles of the voltage applied to the ultrasound probe when generating color image data, spike noise may occur, for example, in the waveform of the first cycle. Such spike noise causes image noise to occur in the color image data.

The above problem does not only occur when switching from a mode that generates B-mode image data to a mode that generates color image data; the same problem occurs, for example, when switching from a relatively high-voltage power supply to a relatively low-voltage power supply.

JP 2008-104629 A JP 2006-26150 A International Publication No. 2011/058956

One of the problems that the embodiments disclosed in this specification and the drawings attempt to solve is to suppress the occurrence of spike noise while suppressing an increase in the size of the transmission circuit. However, the problems that the embodiments disclosed in this specification and the drawings attempt to solve are not limited to the above problem. Problems corresponding to the effects of each configuration shown in the embodiments described below can also be positioned as other problems.

An ultrasonic diagnostic device according to an embodiment includes an ultrasonic probe, a transformer, a first power source, a second power source, a switching unit, a first setting unit, a second setting unit, and a control unit. The ultrasonic probe transmits ultrasonic waves according to the magnitude of the applied voltage. The transformer has a primary coil having two windings and a center tap provided between the two windings, and a secondary coil having one winding, transforms a voltage applied to the primary coil, and applies the transformed voltage to the ultrasonic probe. The first power source applies a first voltage of a first magnitude to the primary coil. The second power source applies a second voltage of a second magnitude smaller than the first magnitude to the primary coil. The switching unit switches the voltage applied to the primary coil to either the first voltage or the second voltage. The first setting unit sets a first connection state between one of the two windings and ground to either a conductive state or a non-conductive state. The second setting unit sets the second connection state between the other of the two windings and the ground to either a conductive state or a non-conductive state. When the voltage applied to the primary coil is switched from the first voltage to the second voltage by the switching unit, the control unit controls the first setting unit and the second setting unit to simultaneously set the first connection state and the second connection state to a conductive state, and then controls the switching unit so that the voltage applied to the primary coil is switched from the first voltage to the second voltage.

FIG. 1 is a block diagram showing an example of the configuration of an ultrasound diagnostic apparatus according to an embodiment. FIG. 2 is a diagram illustrating an example of the configuration of a transmission pulser of a transmission circuit according to an embodiment. FIG. 3 is a diagram for explaining an example of a process executed when the ultrasound diagnostic device alternately switches between a B-mode ultrasound transmission mode and a color ultrasound transmission mode. FIG. 4 is a diagram for explaining an example of a process executed when the ultrasound diagnostic device alternately switches between a B-mode ultrasound transmission mode and a color ultrasound transmission mode. FIG. 5 is a diagram for explaining an example of processing executed by the ultrasound diagnostic apparatus according to the embodiment. FIG. 6 is a diagram for explaining an example of processing executed by the ultrasound diagnostic apparatus according to the embodiment. FIG. 7 is a flowchart showing an example of the flow of processing executed by the control circuit of the ultrasonic diagnostic apparatus according to the embodiment.

The ultrasound diagnostic device according to the embodiment will be described below with reference to the drawings.

(Embodiment)
1 is a block diagram showing an example of the configuration of an ultrasound diagnostic device 1 according to an embodiment. As shown in FIG. 1, the ultrasound diagnostic device 1 according to the embodiment includes a device main body 100, an ultrasound probe 101, an input device 102, and a display 103.

The ultrasonic probe 101 has, for example, a plurality of piezoelectric vibrators (piezoelectric elements). These piezoelectric vibrators generate ultrasonic waves based on a drive signal supplied from the transmission circuit 111 of the transmission/reception circuit 110 of the device main body 100. Specifically, the plurality of piezoelectric vibrators generate ultrasonic waves having a waveform corresponding to the transmission drive voltage when a voltage (transmission drive voltage) is applied by the transmission circuit 111. The waveform of the transmission drive voltage indicated by the drive signal is the waveform of the voltage applied to the plurality of piezoelectric vibrators. That is, the ultrasonic probe 101 transmits ultrasonic waves corresponding to the magnitude of the applied transmission drive voltage. The ultrasonic probe 101 also receives a reflected wave from the subject P, converts the reflected wave into a reflected wave signal (received signal), which is an electrical signal, and outputs the reflected wave signal to the device main body 100. The ultrasonic probe 101 also has, for example, a matching layer provided on the piezoelectric vibrator and a backing material that prevents the propagation of ultrasonic waves backward from the piezoelectric vibrator. The ultrasound probe 101 is detachably connected to the device body 100.

When ultrasonic waves are transmitted from the ultrasonic probe 101 to the subject P, the transmitted ultrasonic waves are reflected successively by the acoustic impedance discontinuity surfaces in the internal tissues of the subject P, and are received as reflected waves by the multiple piezoelectric transducers of the ultrasonic probe 101. The amplitude of the received reflected waves depends on the difference in acoustic impedance at the discontinuous surfaces where the ultrasonic waves are reflected. When the transmitted ultrasonic pulse is reflected by the surface of a moving blood flow or a heart wall, the reflected waves undergo a frequency shift due to the Doppler effect depending on the velocity component of the moving body in the ultrasonic transmission direction. The ultrasonic probe 101 then outputs the reflected wave signal to the receiving circuit 112 of the transmitting/receiving circuit 110, which will be described later.

The ultrasonic probe 101 is detachably attached to the device body 100. When scanning a two-dimensional area (two-dimensional scanning) in the subject P, the operator connects, for example, a 1D array probe in which multiple piezoelectric transducers are arranged in a row to the device body 100 as the ultrasonic probe 101. Types of 1D array probes include linear ultrasonic probes, convex ultrasonic probes, and sector ultrasonic probes. When scanning a three-dimensional area (three-dimensional scanning) in the subject P, the operator connects, for example, a mechanical 4D probe or a 2D array probe to the device body 100 as the ultrasonic probe 101. The mechanical 4D probe is capable of two-dimensional scanning using multiple piezoelectric transducers arranged in a row like the 1D array probe, and is also capable of three-dimensional scanning by swinging the multiple piezoelectric transducers at a predetermined angle (swing angle). In addition, the 2D array probe is capable of three-dimensional scanning using multiple piezoelectric transducers arranged in a matrix, and two-dimensional scanning is possible by focusing and transmitting ultrasonic waves.

The input device 102 is realized by input means such as a mouse, keyboard, button, panel switch, touch command screen, foot switch, trackball, joystick, etc. The input device 102 accepts various setting requests from the operator of the ultrasound diagnostic device 1 and transfers the accepted various setting requests to the device main body 100.

The display 103 displays, for example, a GUI (Graphical User Interface) that allows the operator of the ultrasound diagnostic device 1 to input various setting requests using the input device 102, and displays ultrasound images based on ultrasound image data generated in the device body 100. The display 103 is realized by a liquid crystal monitor, a CRT (Cathode Ray Tube) monitor, or the like.

The device body 100 generates ultrasound image data based on the reflected wave signal transmitted from the ultrasound probe 101. The ultrasound image data is an example of image data. The device body 100 can generate two-dimensional ultrasound image data based on the reflected wave signal transmitted from the ultrasound probe 101 corresponding to a two-dimensional region of the subject P. The device body 100 can also generate three-dimensional ultrasound image data based on the reflected wave signal transmitted from the ultrasound probe 101 corresponding to a three-dimensional region of the subject P. As shown in FIG. 1, the device body 100 has a transmission/reception circuit 110, a buffer memory 120, a signal processing circuit 130, an image generation circuit 140, an image memory 150, a memory circuit 160, and a control circuit 170.

The transmission/reception circuit 110, under the control of the control circuit 170, causes the ultrasonic probe 101 to transmit ultrasonic waves and causes the ultrasonic probe 101 to receive reflected waves of the ultrasonic waves. That is, the transmission/reception circuit 110 executes scanning via the ultrasonic probe 101. Note that scanning is also called scanning, ultrasonic scanning, or ultrasonic scanning. The transmission/reception circuit 110 is an example of a transmission/reception unit. The transmission/reception circuit 110 has a transmission circuit 111 and a reception circuit 112.

The transmission circuit 111 transmits ultrasonic waves from the ultrasonic probe 101 under the control of the control circuit 170. The transmission circuit 111 has a control circuit 111a, a rate pulser generating circuit, a transmission delay circuit, and a transmission pulser. The control circuit 111a controls the rate pulser generating circuit, the transmission delay circuit, and the transmission pulser, and the transmission circuit 111 supplies a drive signal to the ultrasonic probe 101. When scanning a two-dimensional region within the subject P, the transmission circuit 111 transmits an ultrasonic beam for scanning the two-dimensional region from the ultrasonic probe 101. When scanning a three-dimensional region within the subject P, the transmission circuit 111 transmits an ultrasonic beam for scanning the three-dimensional region from the ultrasonic probe 101.

The control circuit 111a is controlled by the control circuit 170 and controls the entire transmission circuit 111. For example, the control circuit 111a controls the rate pulser generating circuit, the transmission delay circuit, and the transmission pulser. The control circuit 111a is realized by a processor. The control circuit 111a is an example of a control unit.

The rate pulser generating circuit, under the control of the control circuit 111a, repeatedly generates rate pulses for forming a transmission ultrasonic wave (transmission beam) at a predetermined rate frequency (PRF: Pulse Repetition Frequency). The rate pulse passes through the transmission delay circuit, and a voltage is applied to the transmission pulser with a different transmission delay time. For example, the transmission delay circuit provides each rate pulse generated by the rate pulser generating circuit with a transmission delay time for each piezoelectric transducer required to focus the ultrasonic waves generated from the ultrasonic probe 101 into a beam and determine the transmission directivity. The transmission pulser supplies a drive signal (drive pulse) to the ultrasonic probe 101 at a timing based on the rate pulse. That is, the transmission pulser applies a voltage (transmission drive voltage) having a waveform indicated by the drive signal to the ultrasonic probe 101 at a timing based on the rate pulse. The transmission delay circuit arbitrarily adjusts the transmission direction of the ultrasonic wave from the piezoelectric transducer surface by changing the transmission delay time provided to each rate pulse.

The drive pulse is transmitted from the transmitting pulser via a cable to the piezoelectric transducer in the ultrasonic probe 101, where it is converted from an electrical signal to mechanical vibration. That is, when a voltage is applied to the piezoelectric transducer, the piezoelectric transducer vibrates mechanically. Ultrasound generated by this mechanical vibration is transmitted into the living body. Here, the ultrasound waves, which have different transmission delay times for each piezoelectric transducer, are focused and propagate in a specified direction.

The transmission circuit 111 has a function that allows instantaneous change of the transmission frequency, transmission drive voltage, etc., in order to execute a predetermined scanning sequence under the control of the control circuit 170. In particular, the change of the transmission drive voltage is realized by a linear amplifier type transmitting circuit that can instantaneously switch the value of the transmission drive voltage, or a mechanism that electrically switches between multiple power supply units.

The reflected wave of the ultrasound transmitted by the ultrasonic probe 101 reaches the piezoelectric transducer inside the ultrasonic probe 101, where it is converted from mechanical vibration to an electrical signal (reflected wave signal) and input to the receiving circuit 112. The receiving circuit 112 has a preamplifier, an A/D (Analog to Digital) converter, a quadrature detection circuit, etc., and performs various processes on the reflected wave signal transmitted from the ultrasonic probe 101 to generate reflected wave data (received data). The receiving circuit 112 then stores the generated reflected wave data in the buffer memory 120.

The preamplifier amplifies the reflected wave signal for each channel and performs gain adjustment (gain correction). The A/D converter converts the gain-corrected reflected wave signal into a digital signal by A/D converting the gain-corrected reflected wave signal. The quadrature detection circuit converts the reflected wave signal, which has been converted into a digital signal, into an in-phase signal (I signal, I: In-phase) and a quadrature signal (Q signal, Q: Quadrature-phase) in the baseband. The quadrature detection circuit then stores the I signal and Q signal (IQ signal) in the buffer memory 120 as reflected wave data.

The receiving circuit 112 generates two-dimensional reflected wave data from the two-dimensional reflected wave signal transmitted from the ultrasonic probe 101. The receiving circuit 112 also generates three-dimensional reflected wave data from the three-dimensional reflected wave signal transmitted from the ultrasonic probe 101.

The buffer memory 120 is a memory that temporarily stores the reflected wave data generated by the transmission/reception circuit 110. For example, the buffer memory 120 is configured to be able to store a predetermined number of frames of reflected wave data. Then, when a new frame of reflected wave data is generated by the reception circuit 112 while a predetermined number of frames of reflected wave data is stored in the buffer memory 120, the buffer memory 120, under the control of the reception circuit 112, discards the oldest generated frame of reflected wave data and stores the newly generated frame of reflected wave data. For example, the buffer memory 120 is realized by a semiconductor memory element such as a RAM (Random Access Memory) or a flash memory.

The signal processing circuit 130 reads the reflected wave data from the buffer memory 120, performs various signal processing on the read reflected wave data, and outputs the reflected wave data that has been subjected to various signal processing to the image generating circuit 140 as B-mode data or Doppler data. The signal processing circuit 130 is realized, for example, by a processor. The signal processing circuit 130 is an example of a signal processing unit.

For example, the signal processing circuit 130 reads out one frame of reflected wave data newly stored in the buffer memory 120 each time one frame of reflected wave data is stored in the buffer memory 120. Then, the signal processing circuit 130 generates one frame of B-mode data or Doppler data by performing various signal processing on the read one frame of reflected wave data each time one frame of reflected wave data is read out. Then, the signal processing circuit 130 outputs one frame of newly generated B-mode data or Doppler data to the image generation circuit 140 each time one frame of B-mode data or Doppler data is generated. An example of the various types of signal processing performed by the signal processing circuit 130 will be described below.

For example, the signal processing circuit 130 performs quadrature detection, logarithmic amplification, envelope detection processing, etc. on the reflected wave data read from the buffer memory 120 to generate B-mode data in which the signal strength (amplitude strength) of each sample point is expressed as luminance. For example, the signal processing circuit 130 outputs the generated B-mode data to the image generation circuit 140.

The signal processing circuit 130 also executes signal processing for performing harmonic imaging to visualize harmonic components. Examples of harmonic imaging include contrast harmonic imaging (CHI) and tissue harmonic imaging (THI). In contrast harmonic imaging and tissue harmonic imaging, the following scanning methods are known. For example, such scanning methods include amplitude modulation (AM), phase modulation (PM), also known as the pulse subtraction method or pulse inversion method, and AMPM, which combines AM and PM to obtain both the effects of AM and PM.

The signal processing circuit 130 also performs frequency analysis on the reflected wave data read from the buffer memory 120 to extract motion information of the moving body (blood flow, tissue, contrast agent echo components, etc.) based on the Doppler effect from the reflected wave data, and generates Doppler data indicating the extracted motion information. For example, the signal processing circuit 130 extracts average speed, average variance, average power value, etc. across multiple points as motion information of the moving body, and generates Doppler data indicating the extracted motion information of the moving body. The signal processing circuit 130 outputs the generated Doppler data to the image generation circuit 140.

Using the above-mentioned function of the signal processing circuit 130, the ultrasound diagnostic device 1 according to the embodiment can perform a color Doppler method, also called a color flow mapping (CFM) method. In the color flow mapping method, ultrasonic waves are transmitted and received multiple times on multiple scanning lines. In the color flow mapping method, a moving target indicator (MTI) filter is applied to the data sequence at the same position to suppress signals (clutter signals) originating from stationary tissue or slow-moving tissue from the data sequence at the same position, and a signal originating from blood flow (blood flow signal) is extracted. In the color flow mapping method, blood flow information such as the blood flow speed, blood flow dispersion, and blood flow power is estimated from this blood flow signal. The signal processing circuit 130 outputs color image data indicating the blood flow information estimated by the color flow mapping method to the image generation circuit 140. Note that the color image data is an example of Doppler data.

The signal processing circuit 130 is capable of processing both two-dimensional and three-dimensional reflected wave data.

The image generation circuit 140 generates ultrasound image data from the B-mode data or Doppler data output from the signal processing circuit 130. The image generation circuit 140 is realized by a processor.

For example, the image generating circuit 140 generates two-dimensional B-mode image data in which the intensity of the reflected wave is expressed as brightness from the two-dimensional B-mode data generated by the signal processing circuit 130. The image generating circuit 140 also generates two-dimensional Doppler image data in which motion information or blood flow information is visualized from the two-dimensional Doppler data generated by the signal processing circuit 130. The two-dimensional Doppler image data in which motion information is visualized is velocity image data, variance image data, power image data, or image data that is a combination of these.

Here, the image generating circuit 140 generally converts (scan converts) the scan line signal sequence of the ultrasound scan into a scan line signal sequence of a video format, such as that of a television, to generate ultrasound image data for display. For example, the image generating circuit 140 generates ultrasound image data for display by performing coordinate conversion on the data output from the signal processing circuit 130 according to the ultrasound scanning form of the ultrasound probe 101. In addition to scan conversion, the image generating circuit 140 also performs various image processing, such as image processing (smoothing processing) that regenerates an average brightness image using multiple image frames after scan conversion, and image processing (edge enhancement processing) that uses a differential filter within the image. In addition, the image generating circuit 140 combines text information of various parameters, scales, body marks, etc., with the ultrasound image data.

Furthermore, the image generation circuit 140 generates three-dimensional B-mode image data by performing coordinate transformation on the three-dimensional B-mode data generated by the signal processing circuit 130. The image generation circuit 140 also generates three-dimensional Doppler image data by performing coordinate transformation on the three-dimensional Doppler data generated by the signal processing circuit 130. That is, the image generation circuit 140 generates "three-dimensional B-mode image data and three-dimensional Doppler image data" as "three-dimensional ultrasound image data (volume data)." The image generation circuit 140 then performs various rendering processes on the volume data to generate various types of two-dimensional image data for displaying the volume data on the display 103.

The rendering process performed by the image generation circuit 140 is, for example, a process of generating MPR image data from volume data using a multi-planar reconstruction method (MPR). In addition, the rendering process performed by the image generation circuit 140 is, for example, a volume rendering (VR) process of generating two-dimensional image data that reflects three-dimensional information. The image generation circuit 140 is an example of an image generation unit.

The B-mode data and Doppler data are ultrasound image data before the scan conversion process, and the data generated by the image generation circuit 140 is ultrasound image data for display after the scan conversion process. Note that the B-mode data and Doppler data are also called raw data.

The image memory 150 is a memory that stores various image data generated by the image generation circuit 140. The image memory 150 also stores data generated by the signal processing circuit 130. The B-mode data and Doppler data stored in the image memory 150 can be called up by the operator after diagnosis, for example, and becomes ultrasound image data for display via the image generation circuit 140. For example, the image memory 150 is realized by a semiconductor memory element such as a RAM or a flash memory, a hard disk, or an optical disk.

The memory circuitry 160 stores control programs for scanning (transmitting and receiving ultrasound), image processing, and display processing, as well as various data such as diagnostic information (e.g., patient ID, doctor's findings, etc.), diagnostic protocols, and various body marks. The memory circuitry 160 is also used to store data stored in the image memory 150 as necessary. For example, the memory circuitry 160 is realized by a semiconductor memory element such as a flash memory, a hard disk, or an optical disk.

The control circuit 170 controls the overall processing of the ultrasound diagnostic device 1. Specifically, the control circuit 170 controls the processing of the transmission/reception circuit 110, the signal processing circuit 130, and the image generation circuit 140 based on various setting requests input by the operator via the input device 102 and various control programs and various data read from the storage circuit 160. The control circuit 170 also controls the display 103 to display an ultrasound image based on ultrasound image data for display stored in the image memory 150. For example, the control circuit 170 controls the display 103 to display a B-mode image based on B-mode image data or a color image based on color image data. The control circuit 170 also controls the display 103 to display a color image superimposed on the B-mode image. The control circuit 170 is an example of a display control unit or a control unit. The control circuit 170 is realized, for example, by a processor. An ultrasound image is an example of an image.

The control circuit 170 also controls the ultrasound probe 101 via the transmission/reception circuit 110, thereby controlling ultrasound scanning.

The term "processor" used in the above description means a circuit such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an Application Specific Integrated Circuit (ASIC), or a programmable logic device (e.g., a Simple Programmable Logic Device (SPLD), a Complex Programmable Logic Device (CPLD), or a Field Programmable Gate Array (FPGA)). The processor reads out a program stored in the memory circuit 160 and executes the read out program to realize its function. Note that instead of storing a program in the memory circuit 160, the program may be directly embedded in the processor circuit. In this case, the processor reads out and executes the program embedded in the circuit to realize its function. Note that each processor in this embodiment is not limited to being configured as a single circuit for each processor, but may be configured as a single processor by combining multiple independent circuits to realize its function. Furthermore, multiple circuits in FIG. 1 (e.g., the signal processing circuit 130, the image generation circuit 140, and the control circuit 170) may be integrated into one processor to realize the functions. That is, the signal processing circuit 130, the image generation circuit 140, and the control circuit 170 may be integrated into one processing circuit realized by a processor.

The overall configuration of the ultrasound diagnostic device 1 according to the embodiment has been described above. Next, an example of the configuration of the transmission pulser of the transmission circuit 111 will be described. FIG. 2 is a diagram showing an example of the configuration of the transmission pulser of the transmission circuit 111 according to the embodiment.

As shown in FIG. 2, the transmission pulser of the transmission circuit 111 includes two power sources 11 and 12, two switches 13 and 14, two diodes 15 and 16, a transformer 17, and two switches 18 and 19. The two power sources 11 and 12 may be provided outside the transmission circuit 111. In this case, the device main body 100 may include the two power sources 11 and 12 provided outside the transmission circuit 111.

The power supply 11 is a power supply for applying a voltage V1 to the primary coil of the transformer 17. Here, the magnitude of the voltage V1 is "V1". The power supply 11 is an example of a first power supply. The voltage V1 is an example of a first voltage. Also, the magnitude "V1" of the voltage V1 is an example of a first magnitude. The negative side of the power supply 11 is connected to the ground. The positive side of the power supply 11 is connected to the anode of the diode 15 via the switch 13.

The power supply 12 is a power supply for applying a voltage V2, which is lower than the voltage V1, to the primary coil of the transformer 17. Here, the magnitude of the voltage V2 is "V2". That is, the magnitude "V2" of the voltage V2 is smaller than the magnitude "V1" of the voltage V1. The power supply 12 is an example of a second power supply. The voltage V2 is an example of a second voltage. Also, the magnitude "V2" of the voltage V2 is an example of a second magnitude. The negative side of the power supply 12 is grounded. The positive side of the power supply 12 is connected to the anode of the diode 16 via the switch 14.

The switch 13 is provided between the power supply 11 and the diode 15. Under the control of the control circuit 111a, the switch 13 sets the connection state between the power supply 11 and the diode 15 to either a conductive state or a non-conductive state.

For example, a case will be described where the switch 13 is turned on (ON) under the control of the control circuit 111a. In this case, the connection between the power supply 11 and the diode 15 becomes conductive, and the power supply 11 applies a voltage V1 to the primary coil of the transformer 17.

Also, for example, a case will be described where the switch 13 is turned off (OFF) under the control of the control circuit 111a. In this case, the connection between the power source 11 and the diode 15 becomes non-conductive, and the power source 11 no longer applies the voltage V1 to the primary coil of the transformer 17.

The switch 14 is provided between the power supply 12 and the diode 16. The switch 14 is controlled by the control circuit 111a to set the connection state between the power supply 12 and the diode 16 to either a conductive state or a non-conductive state.

For example, a case will be described where the switch 14 is turned on under the control of the control circuit 111a. In this case, the connection between the power supply 12 and the diode 16 becomes conductive, and the power supply 12 applies a voltage V2 to the primary coil of the transformer 17.

Also, for example, a case will be described where the switch 14 is turned off under the control of the control circuit 111a. In this case, the connection between the power supply 12 and the diode 16 becomes non-conductive, and the power supply 12 no longer applies the voltage V2 to the primary coil of the transformer 17.

In this way, the switches 13 and 14 switch the voltage applied to the primary coil to either voltage V1 or voltage V2. The switches 13 and 14 are an example of a switching unit. Note that the transmission pulser of the transmission circuit 111 may be provided with one switch instead of the two switches 13 and 14. This one switch may then switch the voltage applied to the primary coil to either voltage V1 or voltage V2. Such a single switch is an example of a switching unit.

Diode 15 is a reverse current prevention diode that prevents current from flowing into the positive side of power supply 11. In other words, diode 15 suppresses current from flowing in the direction from transformer 17 toward power supply 11. The cathode of diode 15 is connected to center tap 17c of the primary coil of transformer 17. Diode 15 is an example of a first suppression unit.

Diode 16 is a reverse current prevention diode that prevents current from flowing into the positive side of power supply 12. In other words, diode 16 suppresses current flow from transformer 17 toward power supply 12. The cathode of diode 16 is connected to center tap 17c of the primary coil of transformer 17. Diode 16 is an example of a second suppression unit.

The transformer 17 has a primary coil and a secondary coil. The transformer 17 transforms the voltage applied to the primary coil and applies the transformed voltage to the ultrasonic probe 101 as a transmission drive voltage.

The primary coil of the transformer 17 includes two windings 17a and 17b and a center tap 17c. The center tap 17c is provided between the two windings 17a and 17b. The secondary coil of the transformer 17 includes one winding 17d. Hereinafter, the number of turns of the winding 17a is defined as "N _17a ", the number of turns of the winding 17b is defined as "N _17b ", and the number of turns of the winding 17d is defined as "N _17d ". Hereinafter, the number of turns of the winding "N _17a " and the number of turns of the winding "N _17b " may be the same, for example. The number of turns "N _17d " may be greater than the number of turns "N _17a ". The number of turns "N _17d " may be greater than the number of turns "N _17b ".

One end of winding 17a is grounded via switch 18. The other end of winding 17a is connected to center tap 17c. One end of winding 17b is connected to center tap 17c. The other end of winding 17b is grounded via switch 19.

One end of the winding 17d is grounded. The other end of the winding 17d is connected to the ultrasonic probe 101. Therefore, the voltage transformed by the transformer 17 is applied to the ultrasonic probe 101.

The two switches 18 and 19 are switches for switching the direction of current flowing through the primary coil (the direction in which current flows in the primary coil).

The switch 18 is connected to the side opposite to the side to which the center tap 17c of the winding 17a is connected, and is provided between the winding 17a and ground. The switch 18 is controlled by the control circuit 111a to set the connection state between the winding 17a and ground to either a conductive state or a non-conductive state. For example, when the switch 18 is turned on under the control of the control circuit 111a, the connection state between the winding 17a and ground becomes a conductive state. When the switch 18 is turned off under the control of the control circuit 111a, the connection state between the winding 17a and ground becomes a non-conductive state. The switch 18 is an example of a first setting unit. The connection state between the winding 17a and ground is an example of a first connection state. The winding 17a is an example of one of the two windings 17a and 17b of the primary coil.

The switch 19 is connected to the side opposite to the side to which the center tap 17c of the winding 17b is connected, and is provided between the winding 17b and ground. The switch 19 is controlled by the control circuit 111a to set the connection state between the winding 17b and ground to either a conductive state or a non-conductive state. For example, when the switch 19 is turned on under the control of the control circuit 111a, the connection state between the winding 17b and ground is a conductive state. When the switch 19 is turned off under the control of the control circuit 111a, the connection state between the winding 17b and ground is a non-conductive state. The switch 19 is an example of a second setting unit. The connection state between the winding 17b and ground is an example of a second connection state. The winding 17b is an example of the other winding of the two windings 17a and 17b of the primary coil.

For example, when switch 18 is turned on and switch 19 is turned off, a positive voltage is applied to the ultrasonic probe 101. When switch 18 is turned off and switch 19 is turned on, a negative voltage is applied to the ultrasonic probe 101.

Thus, in this embodiment, the primary coil of the transformer 17 has two windings 17a, 17b, and a center tap 17c provided between the two windings 17a, 17b. The secondary coil of the transformer 17 has one winding 17d. In this case, the size of the switching circuit around the transformer 17 is relatively small, and therefore the overall size of the transmission circuit 111 is relatively small. Therefore, according to this embodiment, it is possible to suppress an increase in the size of the transmission circuit 111.

Next, we will explain an example of the operation of the transmission circuit 111 when each of the four switches 13, 14, 18, and 19 is either on or off.

First, a case will be described where switch 13 is on, switch 14 is off, switch 18 is on, and switch 19 is off. In this case, voltage V1 is applied to the primary coil by power supply 11. Then, a current flows in a direction from power supply 11 toward the ground connected to switch 18. In other words, a current flows through winding 17a. Then, transformer 17 transforms voltage V1 to a positive voltage _VOUT1 whose magnitude is _VOUT1 ((" _N17d "/" _N17a ")×V1). Then, transformer 17 applies positive voltage _VOUT1 to ultrasonic probe 101.

Next, a case will be described where switch 13 is on, switch 14 is off, switch 18 is off, and switch 19 is on. In this case, voltage V1 is applied to the primary coil by power supply 11. Then, a current flows in a direction from power supply 11 toward the ground connected to switch 19. In other words, a current flows through winding 17b. Then, transformer 17 transforms voltage V1 to a negative voltage "-V _OUT1 " whose magnitude is "-V _OUT1 "(-("N _17d "/"N _17b ")×V1). Then, transformer 17 applies the negative voltage "-V _OUT1 " to ultrasonic probe 101.

In this embodiment, when an ultrasonic transmission mode for generating B-mode image data is set in the ultrasonic diagnostic device 1, the ultrasonic diagnostic device 1 generates B-mode image data. When the ultrasonic diagnostic device 1 generates B-mode image data, the control circuit 111a controls the four switches 13, 14, 18, and 19 so that a positive voltage V _OUT1 and a negative voltage "-V _OUT1 " are alternately applied to the ultrasonic probe 101. That is, the control circuit 111a controls the two switches 13 and 14 so that the voltage applied to the primary coil is switched to voltage V1 when B-mode image data is generated. The B-mode image data is an example of the first image data. In the following description, the ultrasonic transmission mode for generating B-mode image data may be referred to as a "B-mode ultrasonic transmission mode".

Next, a case will be described where switch 13 is turned off, switch 14 is turned on, switch 18 is turned on, and switch 19 is turned off. In this case, voltage V2 is applied to the primary coil by power supply 12. Then, a current flows in a direction from power supply 12 toward the ground connected to switch 18. In other words, a current flows through winding 17a. Then, transformer 17 transforms voltage V2 into positive voltage _VOUT2 whose magnitude is _VOUT2 ((" _N17d "/" _N17a ")×V2). Then, transformer 17 applies positive voltage _VOUT2 to ultrasonic probe 101.

Next, a case will be described where switch 13 is turned off, switch 14 is turned on, switch 18 is turned off, and switch 19 is turned on. In this case, voltage V2 is applied to the primary coil by power supply 12. Then, a current flows in a direction from power supply 12 toward the ground connected to switch 19. In other words, a current flows through winding 17b. Then, transformer 17 transforms voltage V2 into a negative voltage "-V _OUT2 " whose magnitude is "-V _OUT2 "(-("N _17d "/"N _17b ")×V2). Then, transformer 17 applies the negative voltage "-V _OUT2 " to ultrasonic probe 101.

In this embodiment, when an ultrasonic transmission mode for generating color image data is set in the ultrasonic diagnostic device 1, the ultrasonic diagnostic device 1 generates color image data. When the ultrasonic diagnostic device 1 generates color image data, the control circuit 111a controls the four switches 13, 14, 18, and 19 so that a positive voltage V _OUT2 and a negative voltage "-V _OUT2 " are alternately applied to the ultrasonic probe 101. Here, when the ultrasonic diagnostic device 1 generates color image data, the control circuit 111a controls the four switches 13, 14, 18, and 19 so that a combination of a positive voltage V _OUT2 and a negative voltage "-V _OUT2 " is applied to the ultrasonic probe 101 multiple times. In this way, the control circuit 111a controls the two switches 13 and 14 so that the voltage applied to the primary coil is switched to the voltage V2 when color image data is generated. The color image data is an example of the second image data. In the following description, the ultrasonic transmission mode for generating color image data may be referred to as a "color ultrasonic transmission mode".

Here, a case will be described in which the ultrasound diagnostic device 1 generates B-mode image data and color image data, and displays a color image based on the color image data on the display 103 by superimposing the color image based on the color image data on a B-mode image based on the B-mode image data. In this case, the ultrasound diagnostic device 1 repeatedly switches between the B-mode ultrasound transmission mode and the color ultrasound transmission mode. As a result, the ultrasound diagnostic device 1 repeatedly generates B-mode image data and color image data alternately.

Figures 3 and 4 are diagrams for explaining an example of the processing performed by the ultrasound diagnostic device 1 when alternately switching between the B-mode ultrasound transmission mode and the color ultrasound transmission mode.

Figure 4 shows the time series change in the magnitude of the transmission drive voltage applied by the transmission circuit 111 to the ultrasound probe 101. In Figure 4, the horizontal axis indicates time, and the vertical axis indicates the magnitude of the transmission drive voltage. Note that time here refers to, for example, the time of day. In Figure 4, the B-mode ultrasound transmission mode is set from time t1 to time t3. And, the color ultrasound transmission mode is set from time t11 to time t16.

Specifically, first, the control circuit 111a controls the four switches 13, 14, 18, and 19 so that the transformer 17 applies a positive voltage _VOUT1 to the ultrasonic probe 101 during the period from time t1 to time t2.

Then, the control circuit 111a controls the four switches 13, 14, 18, and 19 so that the transformer 17 applies a negative voltage "-V _OUT1 " to the ultrasonic probe 101 during the period from time t2 to time t3.

Then, the control circuit 111a controls the four switches 13, 14, 18, and 19 so that the transformer 17 applies a positive voltage V _OUT2 to the ultrasonic probe 101 during the period from time t11 to time t12.

Then, the control circuit 111a controls the four switches 13, 14, 18, and 19 so that the transformer 17 applies a negative voltage "-V _OUT2 " to the ultrasonic probe 101 during the period from time t12 to time t13.

Then, the control circuit 111a turns off the four switches 13, 14, 18, and 19 so that the transmission drive voltage is not applied to the ultrasound probe 101 between time t13 and time t14.

Then, the control circuit 111a controls the four switches 13, 14, 18, and 19 so that the transformer 17 applies a positive voltage V _OUT2 to the ultrasonic probe 101 during the period from time t14 to time t15.

Then, the control circuit 111a controls the four switches 13, 14, 18, and 19 so that the transformer 17 applies a negative voltage "-V _OUT2 " to the ultrasonic probe 101 during the period from time t15 to time t16.

Here, as shown in FIG. 4, a case will be described in which the control circuit 111a controls the connection states of the four switches 13, 14, 18, and 19 so that the transmission drive voltage is not applied to the ultrasonic probe 101 from time t3 to time t11. For example, the control circuit 111a keeps the switches 13, 18, and 19 off so that the transmission drive voltage is not applied to the ultrasonic probe 101 from time t3 to time t11. The control circuit 111a also keeps the switch 14 off from time t3 to time (t11-Δt), but turns the switch 14 on at time (t11-Δt) and keeps the switch 14 on from time (t11-Δt) to time t13. Here, the time (t11-Δt) refers to a time that is an infinitesimal time before time t11.

In this case, as shown by the two arrows in FIG. 3, the control circuit 111a turns on the switch 14 while keeping the switch 13 off at time (t11-Δt), and then turns on the switch 18 while keeping the switch 19 off at time t11. However, at time t11, charge remains in the primary coil of the transformer 17. The reason why charge remains in the primary coil in this way is that the diode 16 for preventing backflow is connected to the switch 14, and the primary coil is not connected to ground when the switch 14 is turned on. In this case, even if the power source 11 is switched to the power source 12 at time t11, the magnitude of the voltage applied to the primary coil of the transformer 17 is not "V2" but "V1'" which is larger than "V2" as shown in FIG. 3. In this case, when charge remains, as shown in FIG. 4, spike noise 31 may occur in the first period of the waveform of the transmission drive voltage applied to the ultrasonic probe 101 when generating color image data (two periods in the example of FIG. 4). Such spike noise 31 causes image noise in color image data.

Therefore, in this embodiment, the ultrasound diagnostic device 1 executes the process described below to remove the charge remaining in the primary coil of the transformer 17.

FIGS. 5 and 6 are diagrams for explaining an example of processing executed by the ultrasound diagnostic device 1 according to the embodiment. The control circuit 111a executes processing similar to the processing executed between time t1 and time t3 and between time (t11-Δt) and t16 shown in FIG. 6, and between time t1 and time t3 and between time (t11-Δt) and t16 shown in FIG. 4.

As shown in FIG. 6, the control circuit 111a turns off the four switches 13, 14, 18, and 19 so that the transmission drive voltage is not applied to the ultrasonic probe 101 from time t3 to time t4. Here, time t4 is a period within the range from time t3 to time t11.

5 and 6, the control circuit 111a turns on the switches 18 and 19 at the same time at time t4 while keeping the switches 13 and 14 off. The control circuit 111a keeps the switches 13 and 14 off and keeps the switches 18 and 19 on for a certain time period from time t4 to a predetermined time. As a result, as shown by the two arrows in FIG. 5, a current flows in the winding 17a from the center tap 17c toward the ground connected to the switch 18, and a current flows in the winding 17b from the center tap 17c toward the ground connected to the switch 19. Here, the magnitude of the current flowing in the winding 17a and the magnitude of the current flowing in the winding 17b are the same, but the direction of the current flowing in the winding 17a and the direction of the current flowing in the winding 17b are opposite to each other. Therefore, the magnetic fluxes generated inside the transformer 17 cancel each other out, no voltage is generated in the secondary coil, and the charge remaining in the primary coil is removed. The above-mentioned certain time width can be determined, for example, by the time constant of the primary coil (two windings 17a, 17b) of the transformer 17, and a time width is set that allows sufficient removal of the charge. In other words, the above-mentioned certain time width is a time width that corresponds to the two windings 17a, 17b.

Then, the control circuit 111a keeps switches 13 and 14 off and keeps switches 18 and 19 on for a fixed time span from time t4 to a predetermined time, and then keeps switches 13, 18, and 19 off from the predetermined time to time t11 and keeps switch 14 off from the predetermined time to time (t11-Δt).

In this way, when the voltage applied to the primary coil is switched by the switches 13 and 14 from voltage V1 to voltage V2, the control circuit 111a controls the switches 18 and 19 so that the connection state between the winding 17a and ground and the connection state between the winding 17b and ground are simultaneously set to a conductive state for a certain time width. After that, the control circuit 111a controls the switches 13 and 14 so that the voltage applied to the primary coil is switched from voltage V1 to voltage V2.

According to this embodiment, the residual charge in the primary coil is removed, so that the occurrence of spike noise can be suppressed, as shown inside the circle indicated by reference numeral 32 in FIG. 6. Therefore, according to this embodiment, the occurrence of image noise in color image data can be suppressed.

Figure 7 is a flowchart showing an example of the flow of processing executed by the control circuit 111a of the ultrasound diagnostic device 1 according to the embodiment. The processing shown in Figure 7 is executed when the ultrasound diagnostic device 1 generates B-mode image data and color image data, and displays the color image on the display 103 with a color image superimposed on the B-mode image. For example, the control circuit 111a starts executing the processing shown in Figure 7 when an instruction to display the color image on the display 103 with a color image superimposed on the B-mode image is input to the device main body 100 from the user via the input device 102.

(Step S101)
As shown in Fig. 7, in step S101, the control circuit 111a selects a specific transmission for switching the power supply. The specific processing in step S101 will be described below. For example, the control circuit 111a judges whether the current timing is the timing for generating B-mode image data or the timing for generating color image data. If the current timing is the timing for generating B-mode image data, the control circuit 111a selects the B-mode ultrasound transmission mode and sets the selected B-mode ultrasound transmission mode. On the other hand, if the current timing is the timing for generating color image data, the control circuit 111a selects the color ultrasound transmission mode and sets the selected color ultrasound transmission mode.

(Step S102)
Next, in step S102, the control circuit 111a determines whether or not to switch from a high power level to a low power level. The specific process in step S102 will be described below. Specifically, the control circuit 111a determines whether or not the magnitude of the voltage applied to the primary coil by the power source switched in the ultrasonic transmission mode set in this step S101 (the most recent step S101) is smaller than the magnitude of the voltage applied to the primary coil by the power source switched in the ultrasonic transmission mode set in the previous step S101.

For example, if the color ultrasound transmission mode is set in the current step S101 and the B-mode ultrasound transmission mode is set in the previous step S101, the magnitude of the voltage V2 applied to the primary coil in the color ultrasound transmission mode is smaller than the magnitude of the voltage V1 applied to the primary coil in the B-mode ultrasound transmission mode. Therefore, in this case, in step S102, the control circuit 111a determines that the magnitude of the voltage V2 applied to the primary coil in the color ultrasound transmission mode set in the current step S101 is smaller than the magnitude of the voltage V1 applied to the primary coil in the B-mode ultrasound transmission mode set in the previous step S101.

Also, for example, if the B-mode ultrasound transmission mode is set in the current step S101 and the color ultrasound transmission mode is set in the previous step S101, in step S102, the control circuit 111a determines that the magnitude of the voltage V1 applied to the primary coil in the B-mode ultrasound transmission mode set in the current step S101 is greater than the magnitude of the voltage V2 applied to the primary coil in the color ultrasound transmission mode set in the previous step S101.

If the magnitude of the voltage applied to the primary coil by the power source switched in the ultrasonic transmission mode set in the current step S101 is smaller than the magnitude of the voltage applied to the primary coil by the power source switched in the ultrasonic transmission mode set in the previous step S101 (step S102: Yes), the control circuit 111a proceeds to step S103.

On the other hand, if the magnitude of the voltage applied to the primary coil by the power source switched in the ultrasonic transmission mode set in the current step S101 is greater than the magnitude of the voltage applied to the primary coil by the power source switched in the ultrasonic transmission mode set in the previous step S101 (step S102: No), the control circuit 111a proceeds to step S104.

Here, if the process in step S102 executed by the control circuit 111a is the first process in step S102 since the process shown in FIG. 7 was started, the control circuit 111a does not perform the above-mentioned determination process in step S102 and proceeds to step S104.

(Step S103)
In step S103, the control circuit 111a turns off all of the four switches 13, 14, 18, and 19, and then continues to keep the switches 13 and 14 off for a certain period of time while simultaneously keeping the switches 18 and 19 on. Thereafter, the control circuit 111a turns off all of the four switches 13, 14, 18, and 19 again.

For example, as shown in FIG. 6 above, in step S103, the control circuit 111a temporarily turns off all four switches 13, 14, 18, and 19 from time t3 to time t4. Then, the control circuit 111a keeps switches 13 and 14 off for a fixed time period from time t4 to a predetermined time, and keeps switches 18 and 19 on simultaneously. Then, the control circuit 111a turns switches 13, 18, and 19 off again from the predetermined time to time t11, and keeps switch 14 off from the predetermined time to time (t11-Δt).

(Step S104)
Then, in step S104, the control circuit 111a switches the power supply. Specific processing in step S104 will be described below. For example, if the B-mode ultrasound transmission mode is set in the immediately preceding step S101, the control circuit 111a turns on the switch 13. On the other hand, if the color ultrasound transmission mode is set in the immediately preceding step S101, the control circuit 111a turns on the switch 14.

(Step S105)
Then, in step S105, the control circuit 111a controls the four switches 13, 14, 18, and 19 so that the transmission circuit 111 transmits a drive signal according to the ultrasonic transmission mode to the ultrasonic probe 101. Hereinafter, a specific process in step S105 will be described.

For example, if the B-mode ultrasound transmission mode is set in the most recent step S101, the control circuit 111a controls the four switches 13, 14, 18, and 19 so that a positive voltage V _OUT1 and a negative voltage “−V _OUT1 ” are alternately applied to the ultrasound probe 101.

On the other hand, when the color ultrasound transmission mode is set in the most recent step S101, the control circuit 111a controls the four switches 13, 14, 18, and 19 so that the positive voltage V _OUT2 and the negative voltage "-V _OUT2 " are alternately applied to the ultrasound probe 101. Then, the control circuit 111a controls the four switches 13, 14, 18, and 19 so that a combination of the positive voltage V _OUT2 and the negative voltage "-V _OUT2 " is applied to the ultrasound probe 101 multiple times.

(Step S106)
Next, in step S106, the control circuit 111a judges whether or not the current timing is the timing to end the scan. For example, when an instruction to end the scan is input from the user to the device main body 100 via the input device 102, the control circuit 111a judges that the current timing is the timing to end the scan. On the other hand, when such an instruction is not input to the device main body 100, the control circuit 111a judges that the current timing is not the timing to end the scan.

If the current timing is not the timing to end the scan (step S106: No), the control circuit 111a returns to step S101 and executes the processes from step S101 onwards again. On the other hand, if the current timing is the timing to end the scan (step S106: Yes), the control circuit 111a ends the process shown in FIG. 7.

The above describes the ultrasound diagnostic device 1 according to the embodiment. According to this embodiment, as described above, it is possible to suppress the occurrence of spike noise. Furthermore, according to this embodiment, as described above, it is possible to suppress an increase in the scale of the transmission circuit 111. Therefore, according to this embodiment, it is possible to suppress the occurrence of spike noise while suppressing an increase in the scale of the transmission circuit 111.

In the above embodiment, when the ultrasound transmission mode is switched from the B-mode ultrasound transmission mode to the color ultrasound transmission mode, the control circuit 111a simultaneously keeps the switches 13 and 14 off for a certain time width in step S103. However, other than the case described in the above embodiment, when the voltage applied to the primary coil is switched so that the voltage applied to the primary coil is lowered, the control circuit 111a may also simultaneously keep the switches 13 and 14 off for a certain time width. In this case, the drive signal transmitted to the ultrasound probe 101 after the voltage applied to the primary coil is switched so that the voltage applied to the primary coil is lowered may be a signal of one period rather than a signal of multiple periods.

In addition, the control circuit 170 may execute some or all of the processing executed by the control circuit 111a.

The program executed by the processor is provided in advance in a ROM (Read Only Memory) or a storage circuit. The program may be provided in a format that can be installed in these devices or in a format that can be executed, recorded on a non-transitory storage medium that can be read by a computer, such as a CD (Compact Disk)-ROM, a FD (Flexible Disk), a CD-R (Recordable), or a DVD (Digital Versatile Disk). The program may be provided or distributed by being stored on a computer connected to a network, such as the Internet, and downloaded via the network. For example, the program is composed of modules including each of the above-mentioned processing functions. In terms of actual hardware, the CPU reads and executes the program from a storage medium, such as a ROM, so that each module is loaded onto a main storage device and generated on the main storage device.

According to at least one of the embodiments described above, it is possible to suppress the occurrence of spike noise while suppressing an increase in the size of the transmission circuit 111.

Although several embodiments have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are within the scope of the invention and its equivalents as set forth in the claims, as well as the scope and spirit of the invention.

REFERENCE SIGNS LIST 1 Ultrasonic diagnostic device 11, 12 Power supply 13, 14, 18, 19 Switch 15, 16 Diode 17 Transformer 17a, 17b, 17d Winding 17c Center tap 101 Ultrasonic probe 110 Transmitting/receiving circuit 111 Transmitting circuit 111a Control circuit

Claims (7)

an ultrasonic probe that transmits ultrasonic waves according to the magnitude of the applied voltage;
A transformer having a primary coil having two windings and a center tap provided between the two windings, and a secondary coil having one winding, transforming a voltage applied to the primary coil and applying the transformed voltage to the ultrasonic probe;
a first power supply that applies a first voltage of a first magnitude to one of the two windings of the primary coil;
a second power supply that applies a second voltage having a second magnitude smaller than the first magnitude to one of the two windings of the primary coil;
a switching unit connected to the center tap, which switches a voltage state of a voltage applied to one of the two windings of the primary coil to any one of a first voltage state in which the first voltage is applied, a second voltage state in which the second voltage is applied, and a third voltage state in which neither the first voltage nor the second voltage is applied ;
a first setting unit connected to one of the two windings opposite to the side to which the center tap is connected, and configured to set a first connection state between the one winding and ground to either a conductive state or a non-conductive state;
a second setting unit connected to the other of the two windings on a side opposite to the side to which the center tap is connected, and configured to set a second connection state between the other winding and the ground to either a conductive state or a non-conductive state;
a control unit that controls the switching unit to switch the voltage state from the first voltage state to the third voltage state when switching the voltage state from the first voltage state to the second voltage state, and controls the first setting unit and the second setting unit to simultaneously set the first connection state and the second connection state to a conductive state when the voltage state is the third voltage state, and then controls the switching unit to switch the voltage state from the third voltage state to the second voltage state ;
An ultrasound diagnostic device comprising: a first suppression unit that suppresses a current flow from the transformer toward the first power source;
a second suppression unit that suppresses a current flow from the transformer toward the second power source;
The ultrasonic diagnostic apparatus according to claim 1 . the control unit controls the first setting unit and the second setting unit so as to set the first connection state and the second connection state to a conductive state for a certain time width when the voltage state is the third voltage state, when switching the voltage state from the first voltage state to the second voltage state.
3. The ultrasonic diagnostic apparatus according to claim 1. the control unit controls the first setting unit and the second setting unit so as to set the first connection state and the second connection state to a conductive state for the certain time width according to a time constant of the two windings.
The ultrasonic diagnostic apparatus according to claim 3 . the control unit controls the switching unit to switch the voltage state to the first voltage state when first image data is generated, and controls the switching unit to switch the voltage state to the second voltage state when second image data is generated.
5. The ultrasonic diagnostic apparatus according to claim 1. the control unit controls the switching unit to switch the voltage state to the first voltage state when B-mode image data is generated as the first image data, and controls the switching unit to switch the voltage state to the second voltage state when color image data is generated as the second image data.
The ultrasonic diagnostic apparatus according to claim 5. the first setting portion is provided between the one winding and the ground ,
The second setting portion is provided between the other winding and the ground .
7. The ultrasonic diagnostic apparatus according to claim 1.

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