JP2002306476A - Circuit and method for generating pulse wave and continuous wave and ultrasonic diagnostic apparatus having the circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit for generating a pulse wave and a continuous wave in which a pulse wave and a continuous wave is generated by a simple constitution and a common oscillator, and the whole apparatus can be miniaturized and lightened. SOLUTION: A MOSFET 6 of a P channel in which a source terminal connected in series is grounded, a MOSFET 7 of a N channel in which a source terminal is connected to a minus power source via a LC circuit in which a coil 10 and capacitors 12 and 13 are connected in a row, and capacitors 2 and 3 connected between a buffer circuit 1 output and the gate terminals of the MOSFETs 6 and 7 are included, only the MOSFET 7 is switched on to output a pulse of -H [V] when a pulse signal of plus potential is inputted from the buffer circuit 1, and the MOSFETs 6 and 7 are alternately switched on to output a continuous wave between minus potential and 0 [V] when a continuous wave signal of plus/minus potential is inputted from the buffer circuit 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse wave / continuous wave generating circuit, a pulse wave / continuous wave generating method, and an ultrasonic diagnostic apparatus equipped with the pulse wave / continuous wave generating circuit which can be used in an ultrasonic diagnostic apparatus. Things.

[0002]

2. Description of the Related Art In a conventional ultrasonic diagnostic apparatus, signals used for generating ultrasonic waves include pulse waves used in B mode, M mode and pulse Doppler mode.
Although the continuous wave used in the continuous wave Doppler has been used, the pulse wave and the continuous wave have been generated by different signal generation circuits (pulse oscillation circuits), respectively, due to different signal properties.

FIG. 5 shows an example of a pulse wave (PW) pulse oscillation circuit used in this conventional ultrasonic diagnostic apparatus.
Shown in FIG. 5 is a diagram showing an example of a pulse oscillation circuit for generating a pulse wave (PW) used in a conventional ultrasonic diagnostic apparatus.

The circuit shown in FIG. 5 is a pulse oscillation circuit used for generating a pulse wave (pulse transmission) used in the B mode, the M mode and the pulse Doppler mode.
It was configured to be able to generate and output a high-voltage pulse wave of about 20 [V].

However, this circuit configuration cannot generate a continuous pulse wave for a continuous wave (CW) used in a continuous wave Doppler mode.

On the other hand, FIG. 6 shows an example of a conventional continuous pulse oscillation circuit for continuous wave (CW). FIG. 6 is a diagram showing an example of a pulse oscillation circuit used for generating a continuous pulse wave (pulse transmission) for a continuous wave (CW) used in a conventional ultrasonic diagnostic apparatus. The circuit shown in FIG.
It was configured to be able to transmit a continuous pulse wave at around 0 [V] and a lower voltage than the pulse wave (PW) used in the B mode, M mode and pulse Doppler mode. Therefore, it is not suitable for generating a high-voltage pulse wave such as a pulse wave (PW).

[0007]

Conventionally, since two oscillation circuits are provided in this manner, the configuration is complicated, the number of components is large, and it is necessary to secure a space for forming each oscillation circuit. did not become. And
There is no idea of generating a pulse wave and a continuous wave having greatly different properties in one pulse oscillation circuit, and at best, improvements have been made in the direction of improving the efficiency and withstand voltage of an independent pulse oscillation circuit. I was

[0008]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and has a simple circuit configuration of a pulse wave and a continuous wave, particularly a pulse wave and a continuous wave having different voltage levels. Pulse and continuous wave generation circuit, pulse wave and continuous wave generation method, and the pulse wave, which can be generated by a common oscillation circuit and can further reduce the size and weight of the entire apparatus. And an ultrasonic diagnostic apparatus using the continuous wave generating circuit. For example, the following configuration is provided as one means for achieving the object.

That is, a pulse wave and continuous wave generation circuit that can be used for generating ultrasonic waves in an ultrasonic diagnostic apparatus,
A pulse generation mode in which a circuit element is selectively operated to generate a predetermined high-voltage pulse wave corresponding to a predetermined number of input pulse signals, and a relatively low-voltage continuous wave corresponding to an input continuous pulse signal is generated. The continuous wave generation mode to be generated can be selectively operated.

[0010] For example, the pulse wave generated in the pulse generation mode can be used for the pulse wave used in the B mode, the M mode and the pulse Doppler mode in the ultrasonic diagnostic apparatus, and is generated in the continuous wave generation mode. The continuous wave can be used as a continuous wave used in a continuous wave Doppler mode in an ultrasonic diagnostic apparatus.

A pulse wave and continuous wave generation circuit that can be used for generating ultrasonic waves in an ultrasonic diagnostic apparatus,
A buffer circuit for outputting a pulse signal between a ground potential corresponding to a predetermined number of input pulse signals and a predetermined positive potential, a P terminal having a gate terminal connected to the buffer circuit via a first capacitor, and a source terminal grounded. Channel MOS
An FET and a gate terminal are connected to the buffer circuit via a second capacitor, a source terminal is connected to a negative power supply via an LC circuit including a reactance element and a capacitance element, and a drain terminal is connected to the P terminal. An N-channel MOSFET is connected in series with a drain terminal of the channel MOSFET, and an output wave signal is output from between the drain terminals of the P-channel MOSFET and the N-channel MOSFET.

For example, when a continuous pulse signal of a predetermined cycle is supplied from the buffer circuit, the P-channel MOSF is operated by the action of the first and second capacitors.
A pulse signal between ± (the predetermined plus potential / 2) potential is supplied to the gate terminal of the ET, and when the potential is negative, the P-channel MOSFET is operated to set the drain output to the ground potential, and to the N-channel MOSFET gate terminal. ± (the predetermined plus potential /
2) A pulse signal between potentials is supplied, and when the potential is plus (the predetermined plus potential / 2), the N-channel MOSFET is operated to output a continuous wave with a drain output having a minus potential.

Further, the above-mentioned pulse wave and continuous wave generation circuit is provided in an ultrasonic diagnostic apparatus.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on preferred embodiments with reference to the drawings.

First Embodiment FIG. 1 shows a configuration example of a pulse wave / continuous wave generation circuit which can be used for generating ultrasonic waves in an ultrasonic diagnostic apparatus as an embodiment of a pulse wave / continuous wave generation circuit according to the present invention. FIG.

The pulse wave and continuous wave generation circuit of the present embodiment shown in FIG. 1 is a pulse wave (discontinuous pulse wave) used in B mode, M mode and pulse Doppler mode (hereinafter referred to as "PW mode"). Along with the generation, a continuous pulse wave for a continuous wave Doppler mode (hereinafter referred to as “CW mode”) can be generated. These pulse waves need only be generated by simply selecting and supplying a pulse signal to be supplied to the circuit shown in FIG.

In FIG. 1, reference numeral 1 denotes a buffer circuit (MOS
FET DRIVER), which outputs a supply power supply voltage signal (+12 [V]) at a low level (ground potential) input and outputs a ground potential signal at a high level input. Therefore, during operation, a signal of a normal high level is input to the input of the buffer circuit 1, and when outputting a pulse, a pulse which is maintained at a low level at a pulse signal output timing in accordance with the generated pulse signal A signal is input.

Reference numerals 2 and 3 denote capacitor elements for cutting a DC component. Reference numerals 4 and 5 denote resistors for supplying the source terminal potentials to the gate terminals of the P-channel MOSFET 6 and the N-channel MOSFET 7 when the signal of the buffer circuit 1 is not output, thereby maintaining the MOSFETs 6 and 7 in a non-operating state. .

Reference numeral 6 denotes a P-channel MOS which operates when a gate pulse having a voltage lower than the source voltage is input.
FET. In this circuit, the source is ground potential (0
[V]), it operates when a pulse of a negative potential is input to the gate terminal, but does not operate when the gate terminal is at a positive potential and is in a non-conductive state. Reference numeral 7 indicates that the source that operates when a gate pulse having a voltage higher than the source voltage is input is -H [V] via an LC circuit described later.
(Eg, -120 [V] or -20 [V]) is an N-channel MOSFET connected to a power supply.

Reference numerals 8 and 9 denote protection resistors. Reference numeral 10 denotes a coil constituting a reactance element. Reference numerals 12 and 13 denote capacitors which are capacitance elements that constitute an LC circuit with the coil 10. With this LC circuit configuration, when the power supply capacity is insufficient with only the -H [V] power supply at the time of pulse output, this shortfall is compensated for.

Reference numerals 14, 16, 17, and 18 are switching diodes for cutting noise. Reference numeral 15 denotes a transistor for shortening the pulse falling time of the output pulse wave. Reference numeral 19 denotes a resistor for keeping the output side at the ground level when no pulse is output.

The operation of the pulse wave / continuous wave generation circuit of the present embodiment having the above configuration will be described. First, the operation of the ultrasonic diagnostic apparatus when generating a pulse wave used in the PW mode will be described with reference to the timing chart of FIG. FIG. 2 is a timing chart for explaining the operation of the pulse wave and continuous wave generation circuit shown in FIG. 1 when generating a pulse wave (discontinuous pulse wave) used in the PW mode.

In the PW mode, for example, three or four continuous high voltage pulses need to be generated intermittently, and three or four low voltage pulse signals are supplied to the buffer circuit 1. The source terminal of the MOSFET 7 is externally supplied with a high potential -H
[V], for example, -120 [V].

When a pulse wave is generated in the PW mode, for example, three or four +
A pulse signal of 12 [V] is output. This pulse is small in number and contains almost no DC component.
The gate terminal of the SFET 6 is supplied with a pulse signal of the ground potential and +12 [V] potential. Similarly, MOSFET
7 have (-H + 12) [V] and -H [V]
Are supplied.

The P-channel MOSFET 6 operates when a gate pulse having a voltage lower than the source voltage is input, but does not operate in this case because the source terminal is grounded. On the other hand, since the N-channel MOSFET 7 operates when a gate pulse having a voltage higher than the source voltage is input, the source voltage is −H [V], whereas the gate pulse is (−H + 12) [V]. At the timing (when the low-level pulse signal is supplied to the buffer circuit 1) at this timing.
7, and a high-voltage pulse of -H [V] (-120 [V]) is output.

As described above, in the PW mode, the MOSFE
Only T7 operates. In the PW mode, a high voltage of about 120 [V] is handled, so that the P-channel MOSFET 6 having a lower rating than the N-channel MOSFET 7 is not operated.

Next, the operation in the CW mode will be described with reference to the timing chart of FIG. FIG. 3 is a timing chart for explaining the operation of the pulse wave and continuous wave generation circuit shown in FIG. 1 when generating a pulse wave (continuous wave) used in the CW mode.

In the CW mode, it is necessary to generate a continuous wave of a predetermined frequency, and a continuous square wave signal of a predetermined frequency is supplied to the buffer circuit 1. The source terminal of the MOSFET 7 has a relatively low potential -H [V] as -H [V].
[V] For example, power of -20 [V] is supplied.

When a continuous wave is generated in the CW mode,
The buffer circuit 1 outputs a continuous square wave having a predetermined frequency of, for example, 0 [V] to 12 [V]. In this operation mode, since a continuous wave of a predetermined frequency is output, a DC component exists. Since the DC component is removed by the capacitors 2 and 3, the gate pulse becomes as shown in the third and fourth stages of FIG.

That is, a pulse wave of ± 6 [V] is input to the gate terminal of the P-channel MOSFET 6. Since this pulse wave has a section of a negative voltage lower than the ground potential which is a source voltage, the P-channel MOSFET 6 is in a conductive state in this section and holds the drain terminal at the ground potential.

On the other hand, since the N-channel MOSFET 7 operates when a gate pulse having a voltage higher than the source potential is input, the N-channel MOSFET 7 operates during the (-H + 6) [V] section of the gate pulse to be in a conductive state, and the drain terminal is connected. Almost -H
[V]. As described above, in the CW mode, the two MOSFETs 6 and 7 operate alternately to generate a continuous wave.

Next, an example in which the pulse wave and continuous wave generation circuit of this embodiment shown in FIG. 1 is applied to an ultrasonic diagnostic apparatus will be described with reference to FIG. FIG. 4 is a block diagram of an ultrasonic diagnostic apparatus including the pulse wave and continuous wave generation circuit shown in FIG.

In FIG. 4, reference numeral 100 denotes a control unit for controlling the entire ultrasonic diagnostic apparatus; 110, an operation unit for performing various operation inputs; 120, a display unit for displaying a diagnosis result, an ultrasonic echo analysis result, and the like; Is a pulse wave and continuous wave generation circuit shown in FIG. 1, 131 is an oscillation circuit that supplies an input pulse / continuous wave signal to the buffer circuit 1 of the pulse wave and continuous wave generation circuit 130, and 132 is a pulse wave and continuous wave generation circuit A transmission unit that outputs a generated pulse signal from the probe 100 and is disposed near the tip of the probe 133.

Reference numeral 135 denotes a power supply unit for supplying an operation power supply of the apparatus. The power supply unit supplies 12 [V] to the buffer circuit 1 of the pulse wave and continuous wave generation circuit 100,
6 has a power of -120 [V] as -H [V] and -20.
[V] power is supplied. Reference numeral 136 denotes a power supply control circuit. When the operation mode from the operation unit 110 is the PW mode, under control of the control unit 100, -120 [V] is supplied as -H [V] to the pulse wave and continuous wave generation circuit 130. , CW
In the mode, -20 [V] is supplied as -H [V]. When the time constant of the above-described LC circuit is appropriately selected, the circuit is unnecessary.

Reference numeral 140 denotes an ultrasonic signal analyzer, and 145, a receiver which receives an ultrasonic signal output from the transmitter 132 disposed near the tip of the probe 133 and sends the signal to the ultrasonic analyzer 140. The ultrasonic analyzing unit 140 analyzes the ultrasonic signal received by the receiving unit 145, and displays the analysis result on the display unit 120.
To be displayed. Reference numeral 150 denotes a recording device that stores an analysis result.

The ultrasonic analyzer shown in FIG. 4 converts a pulse wave and a continuous wave into a simple circuit configuration as shown in FIG.
In addition, since they can be generated by a common oscillation circuit, further miniaturization and weight reduction of the entire device can be achieved.

[0036]

As described above, according to the present invention, only one type of oscillation circuit for generating a pulse wave and a continuous wave which can be used in an ultrasonic diagnostic apparatus can be prepared.
The structure is simplified, and the size and weight of the entire apparatus can be further reduced. Further, since the pulse wave and the continuous wave can be oscillated in all the channels, the redundancy of the system is improved.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a pulse wave and continuous wave generation circuit that can be used for generating an ultrasonic wave in an ultrasonic diagnostic apparatus according to an embodiment of the present invention.

FIG. 2 is a timing chart for explaining the operation of the pulse wave and continuous wave generation circuit of the present embodiment when generating a pulse wave used in the PW mode.

FIG. 3 is a timing chart for explaining the operation of the pulse wave and continuous wave generation circuit of the present embodiment when generating a pulse wave used in the CW mode.

FIG. 4 is a block diagram of an ultrasonic diagnostic apparatus including the pulse wave and continuous wave generation circuit shown in FIG.

FIG. 5 is a diagram illustrating an example of a pulse generation circuit for PW (pulse wave) used in a conventional ultrasonic diagnostic apparatus.

FIG. 6 is a diagram showing an example of a pulse generator for continuous wave Doppler (CW) used in a conventional ultrasonic diagnostic apparatus.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Izumi Tsubone 3-39-4 Hongo, Bunkyo-ku, Tokyo Fukuda Electronics Co., Ltd. F-term (reference) 4C301 CC02 CC04 DD03 DD04 EE15 EE16 HH01

Claims (9)

[Claims] 1. A pulse wave and continuous wave generation circuit that can be used for generating an ultrasonic wave in an ultrasonic diagnostic apparatus, wherein a circuit element is selectively operated to generate a predetermined number of pulse signals corresponding to a predetermined number of input pulse signals. A pulse wave characterized in that a pulse generation mode that generates a high-voltage pulse wave and a continuous wave generation mode that generates a continuous wave of a relatively low voltage according to an input continuous pulse signal can be selectively operated. Continuous wave generation circuit. 2. The pulse wave generated in the pulse generation mode can be used for pulse waves used in B mode, M mode and pulse Doppler mode in an ultrasonic diagnostic apparatus, and is generated in a continuous wave generation mode. The continuous wave is
2. The pulse wave / continuous wave generation circuit according to claim 1, wherein the pulse wave / continuous wave generation circuit is usable for a continuous wave used in a continuous wave Doppler in an ultrasonic diagnostic apparatus. 3. A pulse wave and continuous wave generation circuit that can be used for generating ultrasonic waves in an ultrasonic diagnostic apparatus, and outputs a pulse signal between a ground potential and a predetermined plus potential corresponding to a predetermined number of input pulse signals. A buffer circuit having a gate terminal connected to the buffer circuit via a first capacitor and a source terminal grounded.
An OSFET, a gate terminal connected to the buffer circuit via a second capacitor, a source terminal connected to a negative power supply via an LC circuit composed of a reactance element and a capacitance element, and a drain terminal connected to the P terminal; N connected in series with the drain terminal of the MOSFET of the channel
And a P-channel MOSFET and an N-channel MOSFET.
A pulse wave and continuous wave generation circuit for outputting an output wave signal from between drain terminals of an FET. 4. When a continuous pulse signal of a predetermined cycle is supplied from the buffer circuit, ± (the predetermined plus potential / 2) is applied to the gate terminal of the P-channel MOSFET by the action of the first and second capacitors. ) A pulse signal between potentials is supplied, and the P-channel MOS
By operating the FET, the drain output is set to the ground potential, a pulse signal between ± (the predetermined plus potential / 2) potential is supplied to the N-channel MOSFET gate terminal with reference to the minus power supply potential, and the plus (the predetermined plus potential) is supplied. /
4. The pulse wave / continuous wave generation circuit according to claim 3, wherein the N-channel MOSFET is operated at the time of 2) to output a continuous wave having a drain output having a negative potential. 5. The semiconductor device according to claim 3, further comprising a transistor connected between drain terminals of said N-channel MOSFET and said P-channel MOSFET to reduce a pulse fall time of said output wave signal. 4. The pulse wave and continuous wave generation circuit according to 4. 6. A method for generating a pulse wave and a continuous wave that can be used for generating an ultrasonic wave in an ultrasonic diagnostic apparatus, wherein a circuit element is selectively operated to generate a predetermined number of pulse signals corresponding to a predetermined number of input pulse signals. A pulse wave characterized in that a pulse generation mode that generates a high-voltage pulse wave and a continuous wave generation mode that generates a continuous wave of a relatively low voltage according to an input continuous pulse signal can be selectively operated. Continuous wave generation method. 7. The pulse wave generated in the pulse generation mode is a pulse wave used in the B mode, the M mode, and the pulse Doppler mode in the ultrasonic diagnostic apparatus, and the continuous wave generated in the continuous wave generation mode is 7. The pulse wave and continuous wave generation method according to claim 6, wherein the method is applicable to a continuous wave used in a continuous wave Doppler in an ultrasonic diagnostic apparatus. 8. A buffer circuit for outputting a pulse signal between a ground potential and a predetermined plus potential corresponding to a predetermined number of input pulse signals, a gate terminal connected to the buffer circuit via a first capacitor, and a source terminal Is connected to the buffer circuit via a second capacitor, a gate terminal is connected to the buffer circuit, and a source terminal is connected to a negative power supply via an LC circuit composed of a reactance element and a capacitance element. Along with
An ultrasonic diagnostic apparatus comprising: an N-channel MOSFET having a drain terminal connected in series with a drain terminal of the P-channel MOSFET; and outputting an output wave signal from between the drain terminals of the P-channel MOSFET and the N-channel MOSFET. A method for generating a pulse wave and a continuous wave in a pulse wave and a continuous wave generation circuit that can be used for generating an ultrasonic wave, wherein when a pulse signal of a predetermined plus potential is supplied from the buffer circuit, the P-channel MOSFET is turned on. When the N-channel MOSFET is turned off and the N-channel MOSFET is turned on to output a pulse signal of the negative power supply potential and a continuous pulse signal of a predetermined cycle is supplied from the buffer circuit, the first and the second are output. The gate terminal of the P-channel MOSFET by the action of the capacitor A pulse signal between ± (the predetermined plus potential / 2) potential is supplied to the P-channel MOSFET at a minus potential.
To supply a drain signal to the ground potential, supply a pulse signal between ± (the predetermined plus potential / 2) potential with respect to a minus power supply potential to the N-channel MOSFET gate terminal, and add a plus (the predetermined plus potential / 2) A method of generating a pulse wave and a continuous wave, wherein the N-channel MOSFET is operated at the time to output a continuous wave having a drain output having a negative potential. 9. An ultrasonic diagnostic apparatus comprising the pulse wave and continuous wave generation circuit according to any one of claims 1 to 4.