JP2758226B2 - Ultrasound diagnostic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to an ultrasonic diagnostic apparatus for selectively connecting a high-voltage power supply and a low-voltage power supply to an ultrasonic transducer.

(Prior art) An ultrasonic diagnostic apparatus generates ultrasonic waves by applying a voltage to an ultrasonic vibrator. When an ultrasonic vibrator is driven, a high-voltage pulse driving method and a low-voltage pulse driving method are roughly classified. . The high-voltage pulse drive method uses relatively high-voltage pulses, for example, 100
This is a method in which a pulse of about 200 V is applied to the ultrasonic vibrator for driving, and corresponds to a case where a B-mode scan or a pulse Doppler scan is performed. On the other hand, the low-voltage pulse driving method is a method in which a relatively low-voltage pulse, for example, a pulse of 5 to 10 V is applied to an ultrasonic vibrator to be driven, and is applicable to a case where a continuous wave Doppler scan for high-speed blood flow detection or the like is performed. I do.

Usually, an ultrasonic diagnostic apparatus is configured so that a plurality of types of ultrasonic transducers corresponding to a plurality of diagnostic modes can be connected. For example, when performing a B-mode scan, an ultrasonic transducer for a B-mode scan is used. When Doppler scan is performed, an ultrasonic transducer for continuous wave Doppler scan can be connected. Therefore, when performing both scans, two types of ultrasonic transducers are switched to generate ultrasonic waves by different pulse driving methods. The ultrasonic transducer used for performing the B-mode scan and the pulse Doppler scan uses an ultrasonic probe configured by arranging a number of ultrasonic transducers in a phased array, and generates ultrasonic waves by electronic focusing. Is performed. On the other hand, when performing a continuous wave Doppler scan, a single probe in which a transmitting transducer and a receiving transducer are arranged in pairs is used.

By the way, recently, even when performing continuous wave Doppler scan, steering continuous wave Doppler scan that can be realized by performing electronic focusing using an ultrasonic probe composed of a phased array has been put to practical use. In this case, the B mode scan and the continuous wave Doppler scan as described above can be performed only by preparing one type of ultrasonic probe. When such a single ultrasonic vibration device performs ultrasonic scans of different pulse drive systems, two types of power supplies that output high and low voltages are required.

FIG. 3 shows a conventional pulse drive circuit.
The variable high voltage power supply VH and the variable low voltage power supply VL are selectively switched by a PW / ▲ ▼ switching signal. These drive circuits are provided for each signal system (channel; ch). PW is the pulse scan mode and the high voltage power supply VH
CW means that the low voltage power supply VL is required in the continuous wave scan mode. SW is a changeover switch, Q ₇
Source driver, Q ₈ consisting Pch power MOSFET sink driver, Q ₉ consisting of Nch power MOSFET is a control transistor consisting NchMOSFET. I ₃ is an inverter, S
Is an ultrasonic transducer, R ₆ and R ₇ are resistors, C ₅ and C ₆ are capacitors,
D ₄ and D ₅ are diodes. Now Ibata I ₃ the trigger signal as shown in FIG. Shall be added. Since the H signal by the inverter I ₃ when initially + 5V [H signal] is added is added is inverted Q ₉ to OV [L signal], Q ₈ by Q ₉ is turned off on I do. On the other hand, C ₅ is VH
(Or VL), so Q ₇ is off. Then since when the L signal is applied to the inverter I ₃ L signal is applied to Q ₉ is inverted to H signal, and drop its drain potential until near OV by Q ₉ is turned on Q ₈ is turned off , whereas C ₅ and connection point R ₆ nor to about 10V drop potential Q
₇ turns on. In this case the changeover switch SW is PW / ▲ ▼ is switched to the VH side by the control of the switching signal is applied pressure via the Q ₇ to the ultrasonic transducer S. On the other hand, SW
When being switched to the VL side low-pressure applied through Q ₇ to the ultrasonic transducer S. On the other hand, when the SW is switched to the VL side low pressure is applied to the ultrasonic transducer S through Q _7. When the trigger signal becomes H again, Q ₉ turns off → Q ₈ turns on, Q ₇ turns off, and the potential of S falls to OV. In state where the Q ₇ by the trigger signal of H → L → H pulse is turned on Q ₈ is turned off, the ultrasonic transducer S according switch position of the changeover switch SW
, A high-voltage pulse or a low-voltage pulse is selectively applied.

By the way, the driving circuit shown in FIG.
Since switched 00V and supply voltage of the low voltage such as 5 to 10V, it is difficult to switch instantaneously under the influence of the time constant circuit consisting of the power output resistor and C _6, usually C ₆ several seconds has become larger Therefore, high-speed switching becomes impossible. Therefore, a switching time of several tens of microseconds is required B
Since the refresh cannot be satisfied, the diagnostic effect is reduced.

FIG. 4 shows another pulse drive circuit in which such a drawback is improved, in which a dedicated drive circuit is provided for each of the high-voltage power supply VH and the low-voltage power supply VL. HD indicates a high-voltage drive circuit, and LD indicates a low-voltage drive circuit. Q ₁₀ , Q
₁₃ is a source driver composed of a Pch power MOSFET, Q ₁₁ and Q ₁₄
Is a sink driver composed of an Nch power MOSFET, and Q ₁₂ and Q ₁₅ are
This is a control transistor composed of an Nch MOSFET. I ₄ is an inverter, N ₃ and N ₄ are NAND gates, S is an ultrasonic transducer, R ₈
Or R ₁₁ is the resistance, C ₇ to C ₁₀ are capacitors, D ₆ to D ₉ is a diode. NAND gate N ₃ and inverter I ₄ have PW /
▲ ▼ Switching signal is added and NAND gate
A trigger signal is applied to N ₃ and N ₄ . Now, assume that the PW / ▲ ▼ signal is + 5V [H]. + 5V at first as trigger signal
Since L signal is outputted from the N ₃ when [H signal] is added, Q ₁₂ is Q ₁₁ are on-and whereas Q ₁₀ is turned off by turning off. Since H signal is output from the N _4, Q ₁₅ is Q ₁₄ is turned off by turning off the other hand Q ₁₃ is C ₈
Is turned off because is charged to VL.

Then because the trigger signal is an H-level signal is outputted from the N ₃ when it becomes OV [L signal], Q ₁₁ Q ₁₂ is being turned on child
There turned off and on the other hand Q ₁₀ is turned on. This increases the high pressure VH to Q ₁₀
Is applied to the ultrasonic vibrator S. At this time, N ₄ does not change. Next, PW / ▲ ▼ is set to OV [L]. Q ₁₂ is turned on N ₃ is H when the first trigger signal is + 5V [H] → Q ₁₁
But off, C ₇ is being charged Q ₁₀ also off VH. Also N ₄
Q ₁₄ by the Q ₁₅ is turned off → Q ₁₄ is turned on by L, Q ₁₃ is turned off, the trigger signal is OV [L], since H signal is output from the N _4, the Q ₁₅ is turned on There turned off and on the other hand Q ₁₃ is turned on. This applied low pressure VL via the Q ₁₃ to the ultrasonic transducer S. At this time, N ₃ does not change. In this way, two types of drive circuits for high voltage and low voltage are prepared, and PW /
By operating either one of them according to the switch signal, a high-voltage or low-voltage pulse is selectively applied to the ultrasonic transducer S.

(Problems to be Solved by the Invention) By the way, the conventional ultrasonic diagnostic apparatus requires two types of drive circuits, and thus has a problem that the circuit scale becomes large when integrated into an IC. Q used especially as a sink driver
_11, since Q ₁₄ is composed of Nch power MOSFET, and increased need element area, the degree of integration because it becomes quite a large area is applied to all channels is reduced.

The present invention has been made in view of the above problems, and has as its object to provide an ultrasonic diagnostic apparatus including a drive circuit so as to reduce the circuit scale.

[Constitution of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides an ultrasonic transducer for transmitting and receiving ultrasonic waves to and from a subject, and high-voltage pulse driving of the ultrasonic transducer. A high-voltage power supply, a low-voltage power supply for driving the ultrasonic vibrator with a low-voltage pulse, and two high-voltage power supplies and a low-voltage power supply that are connected to the low-voltage power supply and apply a high voltage or a low voltage to the ultrasonic vibrator. A source driver, a sink driver commonly connected to the two source drivers, receiving a trigger pulse and controlling the operation of the source driver, and switching between high-voltage pulse driving and low-voltage pulse driving of the ultrasonic transducer. A source driver control circuit for selectively driving the source driver.

(Operation) Since the two source drivers of the high-voltage and low-voltage drive circuits are selectively driven, high-speed switching is enabled. Further, by providing a sink driver in common for two source drivers, the occupied element area can be reduced.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of an ultrasonic diagnostic apparatus according to the present invention, and shows a configuration of a pulse drive circuit. VH a high voltage source to the capacitor C ₃ is connected between the ground, VL is the capacitor C ₄
Low-voltage power supply but connected between ground, Q ₁ is a high-pressure source driver connected to said high voltage power supply VH, Q ₄ is the low-voltage power source VL
Pch power MOS with low voltage source driver connected to
It is composed of FET. Q ₂ is VH, are composed of Nch power MOSFET VL common sink driver, wherein the source driver Q ₁ is connected via the diodes D _1, D _2, the source driver Q ₄ diodes and D _3, It is connected via a D _4. Q ₃ and Q ₅ are transistors provided between the power supply +10 V terminal and the ground terminal, and are source driver control transistors for controlling the source drivers Q ₁ and Q ₄ , respectively. The source driver Q ₁ , gate and capacitor C ₁ are respectively provided. It is connected via a are connected through the gate and the capacitor C ₂ of the source driver Q _4. Q ₆ is provided between the power supply +10 V terminal and the ground terminal, and the sink driver Q ₂
It is connected to the gate of the sink driver Q ₂ sink driver control transistor for controlling. Both Q ₅ and Q ₆ are composed of NcnMOSFETs. I _1, I ₂ respectively switching signals, PW / ▲ ▼, inverter trigger signal is input, N _1, N ₂ in the NAND (NAND) gates, N ₁
Inputs the PW / ▲ ▼ signal and the trigger signal, N ₂ are input with the output trigger signal of the inverter I _1. S
Is provided between the connecting point of the diodes D ₂ and D ₃ in the ultrasonic oscillator ground terminal. The output of the NAND gate N ₁ is connected to the gate of the transistor Q _3, the output of NAND gate N ₂ is connected to the gate of the transistor Q _5, the output of the inverter I ₂ is connected to the gate of the transistor Q ₆ ing. R ₁ , R ₂ , R ₃ are resistors connected between the transistors Q ₆ , Q ₅ , Q ₃ and the power supply + 10 V terminal, respectively, and R ₄ is a resistor provided between the gate of the source driver Q ₁ and the high voltage power supply VH. , R ₅ is the resistance provided between the gate and the low-voltage power source VL of the source driver Q _4.

Next, the operation of the embodiment of the present invention will be described with reference to the timing chart of FIG.

PW / ▲ ▼ in a state where switching as signal + 5V [H signal] is added, the + 5V [H signal as the trigger signal is applied, the transistor Q ₃ so L signal is outputted from the NAND gate N ₁ is Turn off. While transistors Q ₆ because L signal is outputted from the inverter I ₂ is turned off. Therefore, the source driver Q ₁ is turned off, sink driver
Q ₂ turns on. Since the NAND gate N ₂ is H signal is always output transistor Q ₅ is turned on, but the source driver because the capacitor C ₂ immediately by the resistor R ₅ is charged to VL
Q ₄ turns off.

Next, when the trigger signal at t ₁ is inverted to OV [L signal, since an H signal is output transistor Q ₃ is a source driver Q ₁ is also turned on by turning from the NAND gate N _1. The Q ₅ does not change while remaining H signal is output from the NAND gate N ₂ is turned on, Q ₄ remains off.
Meanwhile Q ₂ by Q ₆ are turned on because H signal is output from the inverter I ₂ is turned off. As a result, the high voltage VH is applied to the ultrasonic transducer S via the source driver Q ₁ and the diode D ₁ . This state is continued until t ₂ the trigger signal is inverted to H signal, is off Q ₁ NAND gate N ₁ is L → Q ₃ when the trigger signal is inverted to H at t ₂ is turned off, I ₂ is the L → Q ₆ off → Q ₂ is pulse is terminated by on. If H signal is applied as a trigger signal, the transistor Q ₃ so L signal is outputted from the NAND gate N ₁ is turned off. Also from the NAND gate N ₂ transistor Q ₅ so H signal is output turned on, while the inverter I ₂ transistor Q ₆ of the L signal is output is turned off. Therefore, the source driver Q ₁ is turned off, sink driver Q ₂ is turned on, a source driver Q ₄ is turned off. As a result, a B-mode scan and a pulse Doppler scan can be performed.

When the trigger signal is inverted to L signal at t _5, PW / ▲
▼ is in a state of OV [L signal] is added as a switching signal is always H signal is output from the NAND gate N _1, the source and the transistor Q ₃ are but immediately capacitor C ₁ is turned on is charged to VH driver Q ₁ turns off. Since H signal is output from the NAND gate N ₂ transistor Q ₅
There source driver Q ₄ is also turned on by turning on. On the other hand, the inverter I ₂ sink driver Q ₂ by the transistor Q ₆ is turned on because H signal is output is turned off. As a result, the low voltage VL is applied to the ultrasonic transducer S via the source driver Q ₄ and the diode D ₃ . This state is continued until t ₆ the trigger signal is inverted to H signal, trigger H → N ₁ at t _6, Q _3, Q ₁ is not changed → N ₂ is L → Q ₅ is turned off,
Q ₄ is off, I ₂ is L → Q ₆ is turned off, Q ₂ is on the pulse of the VL is completed by. Between following t ₇ -t _8, between t ₉ -t _10, similar operation between t ₁₁ -t ₁₂ is repeated. By continuing this, a continuous wave Doppler scan can be performed.

According to the present embodiment, two source drivers for high voltage and low voltage are provided, and one sink driver is provided in common with them. It is not necessary to provide one sink driver. Accordingly, a large element area such as a power MOSFE required for a sink driver is occupied, and the number of expensive elements can be reduced. In particular, when the signal system of the ultrasonic diagnostic apparatus is configured from several tens of channels to hundreds of hundreds of channels, reducing the number of sink drivers from two to one increases the element area that can be saved, and can also contribute to cost reduction. .

Further, since two source drivers are provided, switching between high-voltage driving and low-voltage driving can be performed at high speed.
Since the operation like freshness becomes possible, the diagnostic efficiency can be improved.

Although a control circuit is added as compared with the related art, these components are small-signal, low-withstand-voltage components, so that the component size is small and can be formed at low cost. Moreover, since it can be made into an IC, there is almost no increase in cost. The sink driver Q ₂ in CMOS direct low thread hold drivable FE
If T is used, the transistor Q ₆ , inverter, resistor and the like can be eliminated.

In the present embodiment, an example is shown as the configuration of the control circuit of the source driver and the sink driver. However, the present invention is not limited thereto, and other circuits may be used as long as they perform the same operation. For example, although an example in which a capacitor is used for level conversion of a driver control circuit and a source driver has been described, the use of an IC level converter using a high-withstand-voltage IC technology in recent years offers more advantages of integration.

[Effects of the Invention] As described above, according to the present invention, since a pair of source drivers are provided, drive switching can be performed at high speed. Also, since only one sink driver occupying the element area is provided for a pair of source drivers, the circuit scale of the drive circuit can be reduced.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of the ultrasonic diagnostic apparatus of the present invention, FIG. 2 is a timing chart showing the operation of the present embodiment apparatus, and FIGS. 3 and 4 are circuit diagrams showing a conventional example. . Q ₁ ...... high-pressure source driver, Q ₂ ...... sink driver, Q ₃ ...... Q ₁ of control for the FET, Q ₄ ...... low pressure for the source driver, Q ₅ ...... Q ₄ of control for the FET, Q ₆ ... ... Q ₂ of control for the FET, S ...... ultrasonic vibrator, I _1, I ₂ ...... inverter, N _1, N ₂ ......
NAND gate.

Claims (1)

(57) [Claims] 1. An ultrasonic transducer for transmitting and receiving ultrasonic waves to and from a subject, a high-voltage power supply for driving the ultrasonic transducer with high-voltage pulses, and a low-voltage for driving the ultrasonic transducer with low-voltage pulses. A power source, two source drivers connected to the high-voltage power source and the low-voltage power source, respectively, and applying a high voltage or a low voltage to the ultrasonic vibrator; commonly connected to the two source drivers; A sink driver that controls the operation of the source driver, and a source driver control circuit that selectively drives the source driver in accordance with switching between high-voltage pulse driving and low-voltage pulse driving of the ultrasonic transducer; An ultrasonic diagnostic apparatus comprising: