JPH0385146A - Ultrasonic diagnosis apparatus - Google Patents

Abstract

PURPOSE:To make a circuit size of a driving circuit small and to perform rapidly switching of driving by providing two source drivers each selectively applying a high voltage and a low voltage to an ultrasonic vibrator per one signal system and one sink driver. CONSTITUTION:Two source drivers Q1 and Q4 each for high voltage and low voltage and one sink driver Q2 are provided on a pulse driving circuit of an ultrasonic diagnosis apparatus. It becomes thereby unnecessary to provide one sink driver corresponding to one source driver and it is possible to reduce the number of elements occupying a large element area and being expensive. Especially when a signal system of the ultrasonic diagnosis apparatus includes tens to more than a hundred signal channels, the element area saved by reducing sink drivers from 2 to 1 is large and it contributes to cost down. In addition, as source drivers provided are two, it is possible to switch with high speed between high voltage driving and low voltage driving and to improve diagnosis efficiency as such a movement as B fresh becomes possible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention (Industrial Application Field) The present invention relates to an ultrasonic diagnostic apparatus that selectively connects a high-voltage power source and a low-voltage power source to an ultrasonic transducer.

(Prior art) Ultrasonic diagnostic equipment applies voltage to an ultrasonic transducer to generate ultrasonic waves, and there are two main methods for driving the ultrasonic transducer: high-pressure pulse drive method and low-pressure pulse drive method. .

The high-voltage pulse drive method is a method in which a relatively high-voltage pulse, for example, a pulse of 100 to 200 V, is applied to the ultrasonic transducer to drive it, and is applicable to B-mode scans and pulsed Doppler scans. On the other hand, the low-pressure pulse drive method is a method in which relatively low-pressure pulses, for example, 5 to 10 pulses, are applied to the ultrasonic transducer to drive it, and it is used when performing continuous wave Doppler scanning for the purpose of high-speed blood flow detection, etc. Applicable.

Normally, an ultrasound diagnostic device is configured so that multiple types of ultrasound transducers can be connected according to multiple diagnostic modes.For example, when performing a B-mode scan, the ultrasound transducer for B-mode scanning is connected to a continuous When performing a Doppler scan, a continuous wave Doppler scan ultrasound transducer can be connected.

Therefore, when performing both scans, two types of ultrasonic transducers are switched to generate ultrasonic waves using different pulse drive methods. The ultrasonic transducer used to perform Naori Mote Scan and Pulsed Doppler Scan uses an ultrasonic probe consisting of a large number of ultrasonic transducers arranged in a phased array, and generates ultrasonic waves using electronic focusing. is now being carried out.

On the other hand, when performing continuous wave Doppler scanning, a single probe in which a transmitting transducer and a receiving transducer are arranged in pairs is used.

Recently, steering continuous wave Doppler scanning, which can be realized by electronic focusing using an ultrasonic probe consisting of a phased array, has been put into practical use even when performing continuous wave Doppler scanning.

In this case, just by preparing one type of ultrasonic probe, the above-described mode scan and continuous wave Doppler scan can be performed. When performing ultrasonic scans using different pulse drive methods using one ultrasonic diagnostic apparatus, two types of power supplies are required, each outputting a high voltage and a low voltage.

Figure 3 shows a conventional pulse drive circuit, in which a variable high voltage power supply VH and a variable low voltage power supply VL are connected to P W/CW.
It is designed to selectively switch using a switching signal. These drive circuits are connected to each signal system (channel; ch)
established for each Note that PW means that the high voltage power supply VH is required in the pulse scan mode, and CW means that the low voltage power supply VL is required in the continuous wave scan mode. SW
The switch IQ7 is a source driver consisting of a Pch power MO3FET, and Q8 is a Nch power MO8FET.
The sink driver Q9 is a control transistor consisting of an Nch MO3FET.

(2) is an inverter, S is an ultrasonic vibrator, R6 and R7 are resistors, C5 and C6 are capacitors, and D4 and D5 are diodes. Assume that a trigger signal as shown in the figure is now applied to inverter I3. At the beginning, when +5V [H signal is applied, the H signal is set to OV by inverter I3.
[Since the L signal J is inverted and added to Q9, QB is turned on when Q is turned on. On the other hand, C2 is VH (
or VL), Q7 is off.

Next, when an L signal is applied to inverter 3, the L signal is inverted to an H signal and applied to Q, so when Q9 turns on, its drain potential drops to near OV, and Q8 turns off. On the other hand, the potential at the connection point between C6 and R6 also drops by about 10V through C5, turning Q7 on. At this time, if the changeover switch SW is switched to the VH side under the control of the PW/CW switching signal, high voltage is applied to the ultrasonic transducer S via Q7. On the other hand, when sw is switched to the VL side, low pressure is applied to the ultrasonic transducer S via Q7.
is applied to When the trigger signal becomes H again, Q is turned off → Q is turned on, Q7 is turned off, and the potential of S falls to Ov.

In this way, with Q7 turned on and Q8 turned off by the H→L→H pulse trigger signal, a high pressure pulse or a low pressure pulse is selectively applied to the ultrasonic transducer S according to the switching position of the changeover switch SW. be done.

By the way, the drive circuit shown in Fig. 3 switches between a high voltage, for example, 100 to 200V, and a low voltage, for example, 5 to 10V, so it is difficult to switch instantly due to the influence of the time constant circuit consisting of the power supply output resistor and C6. , usually C6
is large and requires several seconds, making high-speed switching impossible. For this reason, it is not possible to satisfy the B refresh which requires a switching time of several tens of microseconds, resulting in a decrease in diagnostic efficiency.

FIG. 4 shows another pulse drive circuit that has improved the above drawbacks, in which dedicated drive circuits are 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. Q10* Q13 is a source driver consisting of Pch power MO8FET, Q Ill Q14 is Nch
Sink driver consisting of power MO8FET, Q x2
tQ15 is a control transistor consisting of an Nch MO8FET. I4 is an inverter, N3. N4 is N
In the AND gate, s is an ultrasonic transducer, R8 to R11 are resistors, C7 to CIO are capacitors, and D6 to D9 are diodes.

A PW/CW switching signal is applied to NAND gate N5 and inverter ■4, and NAND gates N, , R
A trigger signal is added to 4. Now, assume that the PW/CW signal is +5V [H]. +5 initially as a trigger signal
When V[H signal C is applied, L signal is output from N3, so by turning off Q-factor 2, Q-
is on, while Q10 is off. Also, since the H signal is output from R4, by turning off the Q
14 is turned off, while Q13 is turned off since C8 is charged to VL.

Next, when the trigger signal becomes OV CL signal, N3
Since an H signal is output from Q□2, Q□ is turned off and Qto is turned on. As a result, high voltage VH is applied to the ultrasonic transducer S via the QIO. At this time, R4 does not change. Next, P W/C
Let W be OV [L]. Initially, the trigger signal is +5V [
H], N3 is H and Q□2 is on → Q1□ is off,
C7 is charged to VH and Q1o is also turned off. Also R
4 is L and Qs5 is off. Q14 is on, Q13 is off, and when the trigger signal becomes Ov[L], an H signal is output from R4, so when Q15 turns on, Q
14 is turned off while Q13 is turned on. As a result, the low pressure VL is applied to the ultrasonic transducer S via 013.

At this time, N does not change. In this way, by preparing two types of drive circuits, one for high voltage and one for low voltage, and operating one of them using the PW/CW switching signal, high voltage or low voltage pulses can be selectively applied to the ultrasonic transducer S. Ru.

(Problems to be Solved by the Invention) In the conventional ultrasonic diagnostic apparatus, two types of drive circuits are required, so when integrated into an IC, there is a problem that the circuit scale becomes large. Q used especially as a sink driver
Since 111Q 14 is composed of an Nch power MO8FET, it requires a large element area, and if applied to all channels, the area becomes quite large, resulting in a lower degree of integration.

The present invention has been made in response to the above-mentioned problems.
It is an object of the present invention to provide an ultrasonic diagnostic apparatus equipped with a drive circuit whose circuit scale is reduced.

[Structure of the Invention] (Means for Solving the Problem) In order to achieve the above object, the present invention provides an ultrasonic diagnostic apparatus that selectively connects a high-voltage power source and a low-voltage power source to an ultrasonic transducer. The device is characterized in that it includes two source drivers and one sink driver that selectively apply high voltage and low voltage to the ultrasonic transducer, respectively, for each signal system.

(Function) Since the two source drivers of the high-voltage and low-voltage drive circuits are selectively driven, high-speed switching becomes possible. The element area occupied by the sink driver can be reduced.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the ultrasonic diagnostic apparatus of the present invention, and shows the configuration of a pulse drive circuit.

VH is a high voltage power supply, VL is a low voltage power supply, Ql is a high voltage source driver, and Q4 is a low voltage source driver, each of which is composed of a Pch power MO3FET. Q2 is VH, V
It is a common sink driver for L and is composed of an Nch power MO3FET.

Q, , Q are source driver control transistors that control source drivers Q, , Q4, respectively, and Q6
is a sink driver control transistor that controls the sink driver Q2, both of which are composed of Nch MO8FETs. O ■l+■2 is an inverter, N s ,
N2 is a NAND gate, S is an ultrasonic transducer, R1
The resistors are resistors from R6 to R6, the capacitors are from C1 to C4, and the diodes are from Dl to D3. Inverter II, r2, N
AND gate N1. N2 constitutes a control circuit that switches and selects high voltage and low voltage. A PW/CW switching signal is applied to NAND gate N1 and inverter 1, and a trigger signal is applied to NAND gate N2 and inverter 2.

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

+5v [H signal] is added as a trigger signal while +5v [H signal] is added as a P W/CW switching signal.
is added, an L signal is output from N1, so Q
3 is off. On the other hand, since the L signal is output from I2, Q6 is turned off. Therefore, Ql is turned off and Q2 is turned on. Since N2 always outputs an H signal, Q is turned on, but C2 is immediately charged to VL by R6, so Q4
is turned off.

Next, when the trigger signal is inverted to OV [L signal] at tl, an H signal is output from N1, so that Q3 is turned on and Ql is also turned on. Further, since the H signal is outputted from N2 and does not change, Q remains on and Q4 remains off. Since an H signal is output from the - side I2, when Q6 is turned on, Q2 is turned off. As a result, the high voltage VH is applied to the ultrasonic transducer S via Q□ and D□. This state continues until t2 when the trigger signal is reversed to H signal, and when the trigger signal is reversed to H signal at t2, N is L-4-Q 3 is off → Q1 is off, ■2 is L
'= Q1 is off → Q2 is on, and the pulse ends. When an H signal is applied as a trigger signal, an L signal is output from N□, so Q is turned off. Further, since an H signal is output from N2, Q5 is turned on, while an L signal is output from (2), so Q6 is turned off. Therefore, Q
is turned off, Q2 is turned on, and Q4 is turned off. This allows B-mode scanning and pulsed Doppler scanning to be performed.

When the trigger signal is inverted to L signal at t5, PW/
When the OV [L signal is applied as a CW switching signal, an H signal is always output from N1, and Q3 is on, but Ql is immediately turned off because C□ is charged to VH. Since an H signal is output from N2, when Q is turned on, Q4 is also turned on. On the other hand, since an H signal is output from (2), Q6 is turned on and Q2 is turned off. As a result, the low pressure ■L becomes Q4. It is applied to the ultrasonic transducer S via D3. This state continues until t6 when the trigger signal inverts to the H signal, and at t6 the trigger changes from H to N.
Engineering, Q3. Q does not change → N2 is L-I-Q 5 is off, Q4 is off, (2) is L → Q6 is off, Q2 is on, and the VL pulse ends. Below t7-t, between, j
Q j between to, t, -t. Similar operations are repeated between them. By continuing to do this, continuous wave Doppler scanning can be performed.

According to this embodiment, two source drivers for high voltage and low voltage are provided, and one sink driver is provided, so one sink driver corresponds to one source driver as in the conventional case. It becomes unnecessary to provide Therefore, the power MO required for the sink driver
It is possible to reduce the number of high-cost devices that occupy a large device area, such as 3FETs. Particularly when configuring the signal system of an ultrasonic diagnostic device to span several tens to hundreds of channels, reducing the number of sink drivers from two to one can save a large element area and contribute to cost reduction. can.

In addition, since two source drivers are provided, high-voltage drive and low-voltage drive can be switched at high speed, making it possible to perform a B-fresh-like operation, thereby improving diagnostic efficiency.

Although a control circuit is added compared to the conventional model, these components are small-signal, low-voltage components, so the component size is small and can be manufactured at low cost.

Moreover, since it can be integrated into an IC, there is almost no cost increase. Furthermore, if a low threshold CMO8 FET that can be directly driven is used for Q2, Q6, an inverter, a resistor, etc. can be made unnecessary.

In this embodiment, an example of the configuration of the control circuit for the source driver and the sink driver is shown, but the configuration is not limited to these, and other circuits may be arbitrarily adopted as long as they perform similar operations. For example, an example has been described in which a capacitor is used for level conversion between a driver control circuit and a source driver, but the advantage of integration can be obtained by using an IC level converter using recent high-voltage IC technology.

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

[Brief explanation of drawings]

Fig. 2 is a circuit diagram showing an embodiment of the ultrasonic diagnostic device of the present invention, Fig. 2 is a timing chart showing the operation of the device of this embodiment, and Figs. 3 and 4 are circuit diagrams showing a conventional example. . Q: High voltage source driver, Q2: Sink driver, Q3: Ql control FET. Q4...Low voltage source driver, Q,...Q4 control FET. Q6...FET for controlling Q2. S... Ultrasonic transducer, 11. I2...Inverter, Nl, N2...N, AND gate. PW/Puin Boi No. 1 Figure

Claims (3)

[Claims] (1) In an ultrasonic diagnostic device that selectively connects a high-voltage power source and a low-voltage power source to an ultrasonic transducer, one signal system includes two source drivers that selectively apply a high voltage and a low voltage to the ultrasonic transducer, respectively. , and one sink driver. (2) The ultrasonic diagnostic apparatus according to claim 1, comprising two source driver control circuits that control two source drivers, respectively, and a sink driver control circuit that controls a sink driver. (3) The ultrasonic diagnostic apparatus according to claim 1, further comprising a control circuit that switches between high pressure and low pressure.