JP6301114B2 - Ultrasonic diagnostic equipment - Google Patents

Description

  Embodiments described herein relate generally to an ultrasonic diagnostic apparatus.

  As an apparatus for inspecting a subject (living body), an ultrasonic diagnostic apparatus is widely used. Various types of imaging methods such as tomographic images, blood flow display, and contrast imaging have been developed and realized for ultrasonic diagnostic apparatuses.

  Some ultrasonic diagnostic apparatuses have a pulse transmission mode in which high voltage pulse transmission is performed and a continuous wave transmission mode in which transmission is performed by a continuous wave. For some of these transmission modes, there are devices each composed of a separate transmission circuit. On the other hand, many devices that can be realized by one type of transmission circuit have been developed for downsizing and low cost.

  Similarly, a transmission power supply circuit that supplies transmission power to the transmission circuit includes a device that separately configures a power supply circuit for pulse transmission mode and a power supply circuit for continuous wave transmission mode. Some devices consist of circuits.

  Here, as a technique related to such an ultrasonic diagnostic apparatus, an examination state for a subject is detected, and electric power necessary for examination of pulse transmission or continuous wave transmission for the subject is supplied based on the examination state. An ultrasonic diagnostic apparatus is disclosed.

Japanese Patent Application No. 2012-143296

  In the continuous wave transmission mode in the ultrasonic diagnostic apparatus, generally, a relatively low voltage of several volts or less is supplied to the ultrasonic transducer. In contrast, in the pulse transmission mode, a transmission voltage having a high pulse peak value of about 100 V is supplied to the ultrasonic transducer. For this reason, in the transmission power supply circuit of the ultrasonic diagnostic apparatus, it is necessary to variably control the power supply voltage in a wide range from several volts to about 100 volts.

  On the other hand, the continuous wave transmission mode requires a low-noise power output capability as compared with the pulse transmission mode. In addition, the transmission power source needs to be variably controlled with high accuracy in order to comply with the regulation of the acoustic power to the living body.

  However, when the output voltage range of the transmission power supply is set to a wide range, it is necessary to set the gain of the error amplifier for setting the output voltage high. In this case, the digital noise and thermal noise on the input side of the error amplifier are gains. It is multiplied and superimposed on the power supply voltage, and further superimposed on the ultrasonic transmission signal. Therefore, these noises cause SN degradation in the received signal.

  In particular, in the case of the continuous wave transmission mode, the transmission output itself is smaller than that in the pulse transmission mode, so that it is easily affected by noise superimposed on the transmission power source. Further, in the continuous wave transmission mode, since transmission and reception are performed simultaneously, noise superimposed on the transmission power source is likely to leak into the reception side due to crosstalk from the transmission side to the reception side.

  For this reason, a problem may occur that the received signal becomes white due to the influence of these noises and nothing can be seen.

  Therefore, in the case of the continuous wave transmission mode, there has been a demand for an ultrasonic diagnostic apparatus that reduces the noise of the reflected wave to be received by reducing the noise superimposed on the transmission power supply.

The ultrasonic diagnostic apparatus according to the present embodiment includes a transmission circuit that controls to transmit ultrasonic waves from an ultrasonic transducer, and a power supply unit. The power supply unit includes a power supply circuit, and a power control circuit for setting the output voltage to the transmission circuit based on the output voltage of the power supply circuit, the transmission range of the output voltage to the transmitter circuit different Power is supplied to the transmission circuit according to the mode. The power supply control circuit includes a series regulator that supplies power to the transmission circuit, and a voltage setting circuit that includes an error amplifier for setting an output voltage. The voltage setting circuit is a plurality of gains in the error amplifier, and the plurality of gains having different maximum output voltages with respect to a setting voltage between the plurality of transmission modes are switched according to the plurality of transmission modes , The output voltage of the series regulator is controlled .

1 is a schematic configuration diagram showing an example of a schematic configuration of an ultrasonic diagnostic apparatus according to the present embodiment. The circuit diagram showing the composition of the transmission power control circuit of the ultrasonic diagnostic equipment concerning this embodiment. 4 is an explanatory diagram showing a relationship between a set value of a transmission power supply and an output voltage in the transmission power supply control circuit of the ultrasonic diagnostic apparatus according to the embodiment. FIG. The circuit diagram which showed the structure of the transmission power supply control circuit of the ultrasonic diagnosing device which concerns on 2nd Embodiment. The circuit diagram comprised further including the low-pass filter in the transmission power supply control circuit of the ultrasonic diagnosing device concerning 3rd Embodiment. An explanatory view showing a transmission power supply circuit for supplying transmission power to an ultrasonic transmission circuit in a conventional ultrasonic diagnostic apparatus. The schematic diagram which showed typically the input-output characteristic which shows the relationship between the setting value of DAC in the conventional ultrasonic diagnostic apparatus, and the output voltage (VTX output) of a transmission power supply.

  Before describing the ultrasonic diagnostic apparatus according to the present embodiment, a transmission power supply circuit in a conventional ultrasonic diagnostic apparatus will be described.

  FIG. 6 is an explanatory diagram showing a transmission power supply circuit 300 that supplies transmission power to an ultrasonic transmission circuit in a conventional ultrasonic diagnostic apparatus.

  As shown in FIG. 6, the transmission power supply circuit 300 includes an output voltage variable type series regulator 310 composed of an FET (Field Effect Transistor) or the like, a DAC (Digital Analog Converter) 320, a resistor R1, a resistor R2, and a buffer amplifier 330. , An error amplifier 340, a resistor Ri, a resistor Rf, and the like.

  The series regulator 310 stabilizes a VTX input (DC power supply) supplied from a rectifier circuit or a DC power supply, converts it to a desired constant output voltage (VTX output), and uses an ultrasonic transducer as a transmission power supply. This is supplied to the driving transmission circuit.

  The DAC 320 converts a digital setting value corresponding to the output voltage (VTX output) of the transmission power source into an analog setting voltage, divides the analog setting voltage by the resistors R1 and R2, and supplies the analog setting voltage to the buffer amplifier 330.

  The buffer amplifier 330 is configured as a voltage follower with a gain of 1, for example, and the output of the buffer amplifier 330 is input to one end (minus side) of the error amplifier 340.

  Here, if the value of the resistor R2 is set sufficiently large with respect to the value of the resistor R1 (for example, if the resistor R2 is set to 1 MΩ and the resistor R1 is set to 200 kΩ), the voltage is almost the same as the analog setting voltage VDAC (the output voltage of the DAC 320). Is input to one end (minus side) of the error amplifier 340.

  On the other hand, the output voltage (VTX output) of the transmission power source is fed back to the other end (plus side) of the error amplifier 340, and a voltage obtained by dividing the output voltage (VTX output) by the resistor Ri and the resistor Rf is applied. The error amplifier 340 controls the output voltage of the series regulator 310 (that is, the output voltage (VTX output) of the transmission power supply) so that the voltage difference between the two inputs becomes zero.

  As a result, the output voltage (VTX output) of the transmission power supply is a voltage represented by the following equation.

  VTX output = (1 + Rf / Ri) VDAC (1-1)

  The gain of the output voltage (VTX output) with respect to the analog setting voltage VDAC is expressed by the following equation.

  Gain = (1 + Rf / Ri) (1-2)

  In the above two formulas, the resistance R2 is sufficiently larger than the resistance R1.

As can be seen from the above two formulas, in the transmission power supply circuit 300 in the conventional ultrasonic diagnostic apparatus, the output voltage V DAC of the DAC 320 is used for pulse transmission or continuous wave transmission by the gain represented by the formula (1-2). Regardless of the amplification, the output voltage (VTX output) of the transmission power source is set uniformly.

  FIG. 7 is a schematic diagram schematically showing input / output characteristics showing the relationship between the set value of the DAC 320 and the output voltage (VTX output) of the transmission power supply in the conventional ultrasonic diagnostic apparatus.

  As shown in FIG. 7, the gain (straight line indicating the input / output characteristics) in the conventional ultrasonic diagnostic apparatus is the same in the continuous wave transmission mode and the pulse transmission mode.

  For this reason, the noise on the input side of the error amplifier 340 (or the noise converted to the input side) is amplified with the same gain regardless of the continuous wave transmission mode and the pulse transmission mode, and the output voltage of the transmission power supply (VTX output) Voltage).

  Thus, in the transmission power supply circuit 300 of the conventional ultrasonic diagnostic apparatus, since the gain is constant, a high voltage value is required even in the continuous wave transmission mode where only a low voltage value is required. Since the same amount of noise as in the pulse transmission mode is superimposed on the transmission power supply, the influence of noise on the reflected wave in the continuous wave transmission mode was great.

  Further, as can be seen from FIG. 7, in the continuous wave transmission mode, only a part of the low voltage side of the setting range of the DAC 320 is used. On the other hand, in the pulse transmission mode, it is used up to a high voltage range.

  On the other hand, the setting accuracy (roughness of quantization) of the DAC 320 is not different between the continuous wave transmission mode and the pulse transmission mode. For this reason, the setting accuracy of the output voltage in the continuous wave transmission mode is relatively lower than the setting accuracy of the output voltage in the pulse transmission mode.

  Therefore, the ultrasonic diagnostic apparatus according to the present embodiment transmits the gain of the output voltage value with respect to the voltage input value of the transmission power source by switching the controllable range of the output voltage of the transmission power source according to the transmission mode. By switching according to the mode, power supply noise in the continuous wave transmission mode (low output transmission mode) is reduced.

(First embodiment)
Hereinafter, an ultrasonic diagnostic apparatus 100 according to the present embodiment will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic configuration diagram illustrating an example of a schematic configuration of an ultrasonic diagnostic apparatus 100 according to the present embodiment.

  As shown in FIG. 1, the ultrasonic diagnostic apparatus 100 according to this embodiment includes an ultrasonic vibration element 10, an ultrasonic transmission / reception unit 20, a signal processing unit 24, an image processing unit 25, a display unit 26, a power supply unit 30, and a control. A portion 40 is provided.

  The ultrasonic vibration element 10 is an electroacoustic transducer, which converts an electrical drive signal into a transmission ultrasonic wave during transmission, and converts an ultrasonic reflected wave (received ultrasonic wave) into an electrical reception signal during reception. Further, the ultrasonic vibration element 10 constitutes an ultrasonic probe.

  The ultrasonic transmission / reception unit 20 includes a transmission circuit 21 and a reception circuit 22.

  The transmission circuit 21 supplies a drive signal for radiating transmission ultrasonic waves to the ultrasonic vibration element 10 in a predetermined direction of the subject (living body).

  The receiving circuit 22 is configured to perform phasing addition of reception signals of a plurality of channels received from the ultrasonic vibration element 10.

  In the pulse transmission mode (high power transmission mode), the signal processing unit 24 detects the envelope (envelope) of the ultrasonic echo signal and generates a B-mode image based on the blood speed, power, dispersion, etc. In addition to having a function of generating a Doppler image, etc., it has a function of measuring a blood flow velocity in a continuous wave (CW) transmission mode (low output transmission mode).

  The image processing unit 25 has a function of performing necessary image processing on ultrasonic image data such as B-mode image data and color Doppler image data generated by the signal processing unit 24 and causing the display unit 26 to display the data. Yes. Image processing includes coordinate conversion processing for aligning the coordinate system with the imaging section of the subject and gradation processing for setting gradation suitable for image display. In particular, time-series ultrasonic image data after image processing is displayed on the display unit 26 as a moving image in real time.

  The display unit 26 is a display device that displays ultrasonic image data after image processing in the image processing unit 25 as an ultrasonic image.

  The power supply unit 30 includes a transmission power supply circuit 31 and a transmission power supply control circuit 32, and the transmission power supply control circuit 32 includes a series regulator 310 and a voltage setting circuit 34.

  The transmission power supply circuit 31 supplies power necessary for each part of the apparatus by turning on a power switch provided on the operation unit of the ultrasonic diagnostic apparatus 100 or the side surface of the casing, and also transmits to the transmission power supply control circuit 32. DC power is supplied.

  The transmission power supply control circuit 32 receives the transmission mode set by the control unit 40 and switches the output voltage of the transmission power supply of the transmission power supply circuit 31 according to the transmission mode. For example, a low output transmission mode in which the output voltage of the transmission power source is lower than one (eg, continuous wave transmission mode) and a high output transmission mode in which the output voltage of the transmission power source is higher than that in the low output transmission mode (eg, pulse transmission mode) In response to this, the controllable range of the output voltage of the transmission power supply is switched.

  In the low output transmission mode, the transmission power control circuit 32 sets the output voltage range so that the maximum output voltage is lower than the maximum transmission voltage to be set, while the high output transmission is performed. In the case of the mode, the output voltage range is set so that the maximum output voltage becomes higher than the set transmission voltage, and a function of switching between the low output transmission mode and the high output transmission mode is provided.

  The low-power transmission mode is not limited to the continuous wave (CW) transmission mode, and may be a contrast contrast mode used for imaging using a contrast agent. Since the output voltage of the pulse transmission power source in the contrast contrast mode is controlled by the voltage range (several V to 10 V) close to the continuous wave transmission mode, the output voltage is the same as that in the continuous wave transmission mode. By setting to this range, the value of the pulse voltage can be accurately switched. Further, the transmission mode is not limited to two, that is, the low output transmission mode and the high output transmission mode, and may be a mode in which three or more transmission modes are switched.

  The voltage setting circuit 34 of the transmission power supply control circuit 32 is configured by a circuit other than the series regulator 310 in the transmission power supply control circuit 32, and performs voltage setting, transmission mode switching, and the like. .

  The control unit 40 is configured to set the output voltage and the transmission mode for the transmission power supply control circuit 32 based on control information and setting information input by operating an operation unit (not shown).

  FIG. 2 is a circuit diagram showing a configuration of the transmission power supply control circuit 32 of the ultrasonic diagnostic apparatus 100 according to the present embodiment.

  As shown in FIG. 2, the transmission power supply control circuit 32 of the ultrasonic diagnostic apparatus 100 according to the present embodiment includes an output voltage variable series regulator 310, a DAC 320, a resistor R1, an FET (Field Effect Effect Transistor), and the like. A resistor R2, a resistor R3, a buffer amplifier 330, an error amplifier 340, an inverter IV1, a resistor Ri1, a resistor Ri2, a resistor Rf, and the like are provided.

The transmission power supply control circuit 32 according to the present embodiment is different from the conventional transmission power supply circuit 300 shown in FIG. 6 in that the CW_EN signal is used to switch the controllable range of the output voltage VTX of the transmission power supply according to the transmission mode. It is the point which has. More specifically, it has a function of switching the gain of the output voltage VTX with respect to the voltage input value of the transmission power supply (the analog setting voltage V DAC of the output of the DAC 320) according to the transmission mode. The parts common to the conventional transmission power supply circuit 300 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  In the present embodiment, the low power transmission mode and the high power transmission mode are switched by switching the CW_EN signal on and off.

  The CW_EN signal is low when transmitting in a high-power transmission mode (hereinafter also referred to as PW mode) in which transmission is performed with a high voltage, for example, when imaging in the B mode is performed, and blood due to a continuous wave pulse. When transmitting in a low-power transmission mode (hereinafter also referred to as CW mode) in which transmission is performed at a low voltage, for example, when shooting a stream, the signal becomes high.

  Next, the gain in the PW mode (high power transmission mode) is calculated with reference to FIG.

  In the PW mode, the CW_EN signal is low, the switch connected in series to the resistor R3 is turned off, and the switch connected in series to the resistor Ri2 is turned on. At this time, in the circuit from the output of the DAC 320 until the voltage is input to the negative terminal of the error amplifier 340, the output VDAC of the DAC 320 is divided by the resistor R1 and the resistor R2, so the negative side input voltage of the error amplifier 340 Is expressed by the following equation.

  Error amplifier 340 input voltage (−) = R2 / (R1 + R2) × VDAC (2)

  On the other hand, to the plus terminal of the error amplifier 340, a parallel resistance (Ri1 // Ri2) of the resistors Ri1 and Ri2 and a voltage obtained by dividing the output voltage VTX by the resistor Rf are applied. At this time, the relationship between the output voltage VTX of the transmission power supply and the plus-side input voltage of the error amplifier 340 is expressed by the following equation when the impedance of the transistor of the error amplifier 340 is ignored.

  Output voltage VTX = (1+ (Rf / (Ri1 // Ri2))) × input voltage of error amplifier 340 (+) (3)

  Since the negative side voltage and the positive side voltage of the error amplifier 340 are equal to each other, the gain GPW (= VTX / VDAC) in the PW mode is expressed by the following equation from the equations (2) and (3).

GPW = (R2 / (R1 + R2)) × (1+ (Rf / (Ri1 // Ri2)))
... (4)

  Next, a gain in the CW mode (low output transmission mode) is calculated.

  In the CW mode, the CW_EN signal is High, and the switch connected in series to the resistor R3 is turned on. At this time, in the circuit from the output of the DAC 320 to the negative terminal of the error amplifier 340, the resistor R2 and the resistor R3 are connected in parallel to the positive terminal of the buffer amplifier 330, and this parallel resistance (R2 // R3) and The gain of this circuit is determined by the divided voltage of the resistor R1. Therefore, the input voltage of the error amplifier 340 is expressed by the following equation.

  Input voltage of the error amplifier 340 (−) = (R2 // R3) / (R1 + (R2 // R3)) × VDAC (5)

  In the CW mode, the switch of the resistor Ri2 is turned off by the inverter IV1. Therefore, the output voltage VTX of the transmission power supply is expressed by the following equation using the resistor Ri1 and the resistor Rf.

  Output voltage VTX = (1+ (Rf / (Ri1))) × input voltage (+) of error amplifier 340 (6)

  As in the PW mode, the negative and positive voltages of the error amplifier 340 are equal to each other. Therefore, the gain GCW (= VTX / VDAC) in the CW mode is expressed by the following equation using the equations (5) and (6). expressed.

GCW = (R2 // R3) / (R1 + (R2 // R3) × (1+ (Rf / (Ri1)))
... (7)

  Here, a specific resistance value is set as an example for each resistor. For example, the resistor R1 is set to 2 kΩ, the resistor R2 is set to 1 MΩ, the resistor R3 is set to 220Ω, the resistor Ri1 is set to 250Ω, the resistor Ri2 is set to 200Ω, and the resistor Rf is set to 1 kΩ.

  In this case, the gain GPW in the PW mode is 9.98 times from Equation (4), whereas the gain GCW in the CW mode is 0.495 times from Equation (7).

  For example, when the variable range of the output of the DAC 320 is 0V to 2V, the controllable range of the output voltage VTX of the transmission power supply is 0V to 19.960V in the PW mode, while 0V to in the CW mode. 0.991V.

  FIG. 3 is an explanatory diagram showing the relationship between the set value of the transmission power supply and the output voltage in the transmission power supply control circuit 32 of the ultrasonic diagnostic apparatus 100 according to the present embodiment.

  FIG. 3 shows the output voltage when the respective transmission power sources are set in the PW mode and the CW mode, and each output voltage is obtained by multiplying the set voltage by a different gain. Is shown.

  Specifically, when the PW mode is set, it indicates that the set voltage set in the DAC 320 is multiplied by 9.98 and the maximum output voltage is output. On the other hand, when the CW mode is set, it indicates that the set voltage set in the DAC 320 is multiplied by 0.495 and the maximum output voltage is kept low.

  Further, since the gain (gain) is set low in the CW mode, the maximum value of the transmission power supply output voltage can be lowered even if the variable range of the DAC 320 is set to the maximum value. As a result, the CW mode Thus, it is possible to improve the setting accuracy of the output voltage at.

  As described above, the ultrasonic diagnostic apparatus 100 according to the present embodiment can switch the controllable range of the output voltage of the transmission power according to the transmission mode in the transmission power control circuit 32 of the power supply unit 30. In other words, the gain of the output voltage of the transmission power supply with respect to the analog setting voltage that is the output of the DAC 320 can be switched according to the transmission mode.

  For this reason, noise superimposed on the transmission voltage in the CW mode (for example, in the continuous wave transmission mode or contrast contrast mode) can be reduced, and the setting accuracy of the low voltage region can be improved. The control accuracy of the transmission voltage is improved in the low pulse transmission mode and contrast contrast mode.

  In addition, since the transmission power control circuit 32 according to the present embodiment can reduce noise in the CW transmission mode without selecting a low noise amplifier, the cost can be reduced and the power circuit can be simplified. it can.

(Second Embodiment)
FIG. 4 is a circuit diagram showing a configuration of the transmission power control circuit 42 of the ultrasonic diagnostic apparatus according to the second embodiment.

  The ultrasonic diagnostic apparatus according to the second embodiment has a configuration in which a regulator 423 is further provided in series before the series regulator 310 in the transmission power supply control circuit 32. The regulator 423 provided in the preceding stage is also a voltage control type regulator, and can be configured by a PWM (Pulse Width Modulation) type switching regulator having a lower loss than a series regulator.

  By providing a regulator 423 in front of the series regulator 310, power supply noise can be further reduced, and by controlling the control voltage to the regulator 423 (the output voltage of the buffer amplifier 422), the series regulator 310 can be controlled. The input voltage can be adjusted.

  Although the series regulator 310 exhibits excellent characteristics from the viewpoint of voltage stabilization, when the voltage difference between the input side and the output side of the series regulator 310 is large (when the input voltage is higher than the output voltage), the voltage A power loss corresponding to the difference occurs internally.

  As described above, in the first embodiment, the output voltage VTX of the transmission power supply (that is, the output voltage of the series regulator 310) is switched according to the transmission mode. Therefore, for example, when switching to the CW mode while a high voltage corresponding to the output voltage in the PW mode is being input to the series regulator 310, the voltage difference between the input voltage and the output voltage of the series regulator 310 increases in the CW mode. Power loss occurs in the series regulator 310.

  Therefore, in the second embodiment, the input voltage of the series regulator 310 is switched according to the transmission mode.

  In FIG. 4, the transmission power control circuit 32 of the ultrasonic diagnostic apparatus 100 according to the first embodiment further includes a power control I / F (interface) 410 and a regulator circuit 420.

  The regulator circuit 420 includes a pulse width modulation regulator 423, a DAC 421 for setting and controlling the output voltage of the regulator 423, and a buffer amplifier 422. Since other configurations are the same as the circuit configuration of the first embodiment, description thereof is omitted.

  The power supply control I / F 410 has a function of setting a transmission voltage in the regulator circuit 420, a function of setting a transmission power supply in the DAC 320, and a function of switching between the CW mode and the PW mode.

  The power supply control I / F 410 passes a voltage for controlling the regulator 423 via the DAC 421 and the buffer amplifier 422 so that the output voltage of the regulator 423 is higher than the output voltage VTX of the transmission power supply by a predetermined offset voltage. Apply.

  The power supply control I / F 410 switches the setting value depending on the transmission mode. In the PW mode, the power supply control I / F 410 sets the output voltage of the regulator 423 higher by, for example, + 2V than the output voltage VTX of the transmission power supply in the PW mode. In the CW mode, the output voltage of the regulator 423 is set higher by, for example, +0.5 V than the output voltage VTX of the transmission power supply in the CW mode.

  In the CW mode, the output current is substantially constant over time, so that the output current can be stably supplied without setting the input / output power difference (offset voltage) of the series regulator 310 so large. Rather, setting the offset voltage as small as possible is preferable from the viewpoint of reducing power loss in the series regulator 310.

  On the other hand, in the PW mode, since pulse driving is intermittently performed, the output fluctuation of the transmission power source becomes large unless the input / output power difference (offset voltage) of the series regulator 310 is set to be large to some extent.

  Therefore, in the PW mode, an offset voltage (for example, 2V) larger than the offset voltage (for example, 0.5V) in the CW mode is set. Further, since the output current in the PW mode is much smaller than that in the CW mode on a time average, the power loss is small even if the voltage between the input and output (offset voltage) is increased.

  As described above, in the second embodiment, the transmission power control circuit 32 of the ultrasonic diagnostic apparatus 100 according to the first embodiment further includes the power control I / F 410 and the pulse modulation type regulator circuit 420. Thus, transmission noise can be reduced and power loss in the series regulator 310 can be reduced.

  In the second embodiment, a predetermined offset voltage is set in the regulator circuit 420. However, the present embodiment is not limited to this, and a gain of 10% is added to the transmission power source, Both offsets may be calculated and set by taking these into account.

(Third embodiment)
In the third embodiment, the ultrasonic diagnostic apparatus 100 according to the first embodiment is further provided with a low-pass filter.

  FIG. 5 shows a circuit diagram in which the transmission power supply control circuit 52 of the ultrasonic diagnostic apparatus according to the third embodiment is further provided with a low-pass filter (LPF) 500.

  The LPF 500 has a function of passing a low frequency and blocking a high frequency.

  In the first embodiment, the transmission power control circuit 52 according to the third embodiment causes the low-pass filter to function when the CW mode is selected by the CW_EN signal. On the other hand, when the PW mode is selected, the LPF 500 is bypassed.

  As a result, the transmission power control circuit 52 can flow a large current without receiving a loss due to the LPF 500 in the PW mode, while the LPF 500 reduces noise due to high frequency components in the CW mode. Can be achieved.

  In the third embodiment, the transmission power supply control circuit 32 of the ultrasonic diagnostic apparatus 100 according to the first embodiment further includes the LPF 500 that functions in the CW mode. However, the present invention is not limited to this. It is not a thing. For example, even in a conventional ultrasonic diagnostic apparatus, the CW mode may be set by a CW_EN signal or the like, and the LPF 500 may function at that time.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 10 Ultrasonic vibrating element 20 Ultrasonic transmission / reception part 21 Transmission circuit 22 Reception circuit 23 Transmission / reception power supply unit 24 Signal processing part 25 Image processing part 26 Display part 30 Power supply unit 31 Transmission power supply circuit 32,42,52 Transmission power supply control circuit 34 Voltage Setting circuit 40 Control unit 100 Ultrasonic diagnostic apparatus 310 Series regulator 320 DAC
330 Buffer amplifier 340 Error amplifier 410 Power control I / F
420 Regulator circuit 421 DAC
422 Buffer amplifier 423 Regulator 500 Low pass filter (LPF)

Claims (8)

A transmission circuit that controls to transmit ultrasonic waves from the ultrasonic transducer;
A power supply circuit, and a power control circuit for setting the output voltage to the transmission circuit based on the output voltage of the power supply circuit, wherein in response to the transmission mode ranges different in output voltage to the transmission circuit A power supply unit for supplying power to the transmission circuit;
With
The power supply control circuit
A series regulator for supplying power to the transmission circuit;
A voltage setting circuit for providing an error amplifier for setting the output voltage;
With
The voltage setting circuit includes:
The plurality of gains in the error amplifier, wherein the plurality of gains having different maximum output voltages with respect to a set voltage between the plurality of transmission modes are switched in accordance with the plurality of transmission modes , whereby the output voltage of the series regulator To control the
Ultrasonic diagnostic equipment. The plurality of transmission modes have at least a high-power transmission mode and a low-power transmission mode,
The voltage setting circuit sets a wide range of the output voltage in the high output transmission mode, and sets the output voltage range narrower in the low output transmission mode than in the high output transmission mode. ,
The ultrasonic diagnostic apparatus according to claim 1. Before SL voltage setting circuit, a digital converts the set voltage of the digital to analog control voltage - providing analog conversion circuit, the series regulator based on the control voltage for controlling the output voltage of the power supply circuit Control,
The ultrasonic diagnostic apparatus according to claim 2 . Wherein the voltage setting circuit among the plurality of gain, the gain at the time of low power transmission mode and sets lower than the gain at the time of the high output transmit mode, before Symbol Digital - full scale value of the analog conversion circuit Corresponding to the maximum value of the output voltage of the power supply control circuit in the low-power transmission mode ,
The ultrasonic diagnostic apparatus according to claim 3. The voltage setting circuit switches the input voltage of the series regulator according to the plurality of transmission modes so that a voltage difference between the input and output of the series regulator becomes a predetermined offset voltage.
The ultrasonic diagnostic apparatus according to claim 3 or 4. The voltage setting circuit sets the offset voltage smaller in the low output transmission mode than in the high output transmission mode.
The ultrasonic diagnostic apparatus according to claim 5. The voltage setting circuit includes:
A low-pass filter that allows low frequencies to pass and blocks high frequencies is further provided on the output end side of the series regulator ,
The low-pass filter functions in the low-power transmission mode, while the low-pass filter is bypassed in the high-power transmission mode.
The ultrasonic diagnostic apparatus according to claim 2. The low power transmission mode is a continuous wave transmission mode or a contrast contrast mode with a contrast agent, and the high power transmission mode is a pulse transmission mode.
The ultrasonic diagnostic apparatus according to claim 2.

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