JP2000014675A - Ultrasonograph - Google Patents

Abstract

PROBLEM TO BE SOLVED: To optimize the dynamic ranges of the reception circuits of an ultrasonic Doppler blood flow meter for both pulse Doppler and continuous wave Doppler modes. SOLUTION: Pulse ultrasonic waves are generated by a high-pressure transmission drive means 10 and continuous ultrasonic waves are generated by a CW transmission drive means 11. The pulse ultrasonic waves and the continuous ultrasonic waves are selected by a transmission selection means 5 according to a pulse Doppler mode and a continuous wave Doppler mode and are applied via an acoustic scan means 2 to an ultrasonic probe 1 comprising a plurality of ultrasonic vibrators. Input echo signals corresponding to transmit signals are inputted to preamplification means 15, 16 via the ultrasonic probe 1 and the acoustic scan means 2. The input echo signals are processed by a signal processing means 20 or CW signal processing means 25 according to the mode. The echo signals of the continuous ultrasonic waves are processed by the CW signal processing means 25 having a wide dynamic range, while the echo signals of the pulse ultrasonic waves are processed by the low-cost signal processing means 20 having a narrow dynamic range. Because of the use of the signal processing means that is best suited for each mode, cost performance can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ultrasonic diagnostic apparatus, and more particularly, to an ultrasonic diagnostic apparatus capable of measuring an ultrasonic Doppler blood flow by a continuous wave Doppler method and a pulse Doppler method.

[0002]

2. Description of the Related Art A conventional ultrasonic diagnostic apparatus capable of Doppler blood flow measurement has a configuration disclosed in Japanese Patent Application Laid-Open No. 63-315037. Hereinafter, the configuration will be described with reference to FIG. In FIG. 7, an ultrasonic probe 80 is a probe composed of a plurality of elements. 80a to 80h are transmitting ultrasonic elements, and 80i to 80p are ultrasonic elements used for receiving. The reference signal generating means 81 is a circuit for generating a clock having a constant frequency. The delay unit 82 is a unit that generates a transmission signal with a delay time according to the deflection angle of the ultrasonic wave and the region of interest based on the clock from the reference signal generation unit 81. The driving unit 83 is a unit that drives a plurality of elements of the ultrasonic probe 80 with the delayed transmission signal. The 90-degree phase shifter 90 is a circuit that divides the clock signal from the reference signal generating means 81 by the frequency divider 85 and delays the clock signal by 90 degrees. The delay addition means 84 is means for delay-adding echo signals received by a plurality of elements of the ultrasonic probe 80 in accordance with deflection and convergence. The quadrature detector 89 is a circuit that detects the received echo signal output from the delay adding means 84. The frequency analyzer 91 is a circuit that performs frequency analysis on the Doppler signal from the quadrature detector 89. The display means 92 is a display device that displays the analysis result of the frequency analyzer 91.

[0003]

The ultrasonic continuous wave Doppler blood flow meter having the above-mentioned structure requires a receiving circuit having a wide dynamic range. However, the ultrasonic probe 80
The wide dynamic range of the receiving circuit cannot be utilized due to the fact that the transmission signal for driving the signal is directly mixed into the receiving circuit. In a conventional circuit, since a rectangular wave is used as a transmission wave, higher harmonics of the transmission wave are directly mixed into the reception circuit to raise the noise level, and the effective dynamic range of the circuit for the reception signal becomes insufficient. . for that reason,
When observing a blood flow around a strong echo, there is a problem that a Doppler signal cannot be obtained intermittently.

When the present invention is applied to an ultrasonic diagnostic apparatus which simultaneously realizes the continuous Doppler method and the pulse Doppler method,
The receiving circuit is shared by the continuous Doppler method and the pulse Doppler method, and has the following problems.

In the continuous Doppler method, since the crosstalk between transmission and reception in the ultrasonic probe is large, the amplitude of the received echo input to the signal processing circuit and the delay addition circuit is about 15 to 20 dB larger than that of the pulse Doppler method. For this reason, we want to widen the input dynamic range of the signal processing circuit in accordance with the continuous Doppler method. However, a gain adjustment IC used in the signal processing circuit is required for each receiving channel, and the dynamic range exceeds the IC specification. If it is required, a dedicated IC is required, and the power consumption is greatly increased. As a result, the manufacturing cost of the entire device is significantly increased, and this is not a practical measure.

On the other hand, when the dynamic range of the pulse Doppler method is adjusted in consideration of the cost as described above, the received echo signal is distorted due to the shortage of the dynamic range in the continuous Doppler method. This signal distortion is caused by the saturation phenomenon of the circuit, and a mirror phenomenon as shown in FIG. 8 (FIG. 9 shows a spectrum in a state where no mirror is generated) occurs on the Doppler spectrum with a decrease in the receiving sensitivity, which originally does not exist. There is also a problem that a Doppler signal is displayed and there is a risk of misdiagnosis.

In the continuous Doppler method, when an ultrasonic signal of, for example, 2 MHz is handled, the delay time of the reception delay adding circuit for performing electronic focusing is about 7.5 μsec in the pulse Doppler method. hand,
0.5 μsec is sufficient. For this reason, in the continuous Doppler method, even though only the delay addition circuit corresponding to 0.5 μsec is operated, other delay addition circuits that do not contribute to the delay addition are also operating at the same time, which is a noise source. There is a problem that the S / N ratio is greatly deteriorated.

The present invention solves such a conventional problem, and can obtain an optimum dynamic range for a received echo signal for both the continuous Doppler method and the pulse Doppler method. It is an object of the present invention to provide an ultrasonic diagnostic apparatus in which the scale of a circuit for processing an echo signal is increased, the cost is increased, and power consumption is suppressed.

[0009]

According to the present invention, there is provided an ultrasonic diagnostic apparatus comprising: an ultrasonic probe comprising a plurality of transducers; and an acoustic scanning device for scanning the ultrasonic probe. Means, first transmitting means for transmitting an ultrasonic pulse signal into a living body via the acoustic scanning means and the ultrasonic probe, and ultrasonic continuous signals via the acoustic scanning means and the ultrasonic probe. Second transmitting means for transmitting an ultrasonic pulse signal or an ultrasonic continuous signal to the acoustic scanning means, and corresponding to an ultrasonic pulse signal from the living body. First reception signal processing means for inputting the received reception echo signal via the ultrasonic probe, the acoustic scanning means, and the preamplification means, and converting the reception echo signal corresponding to the ultrasonic continuous signal from the living body Input via acoustic probe, acoustic scanning means and preamplifier That a has a configuration which includes a second reception signal processing unit.

With this configuration, the reception echo signal in the ultrasonic pulse Doppler mode is amplified by the first reception signal processing means, and the reception echo signal in the continuous wave Doppler mode is processed by the second reception signal processing means. And the optimum dynamic range and S
The received echo signal can be processed at the / N ratio.

In addition, the preamplifier is provided with an input channel corresponding to a reception channel of an ultrasonic continuous signal which operates only in an ultrasonic continuous signal mode, and in both an ultrasonic continuous signal mode and an ultrasonic pulse Doppler mode. The configuration includes an input channel that operates and a plurality of input channels.
With this configuration, only the preamplifier required for the operation mode can be operated, and the S / N ratio and the power consumption can be improved.

Further, the second transmitting means is provided with a signal generator for giving a phase difference to a plurality of ultrasonic sine wave signals to deflect the ultrasonic waves transmitted from the ultrasonic probe. With such a configuration, the deflection of the ultrasonic beam in the ultrasonic continuous signal mode can be realized with a simple circuit.

Further, the second received signal processing means is provided with a circuit for amplifying and processing the echo signals of the continuous ultrasonic waves of a plurality of channels inputted through the preamplifier. With this configuration, the second received signal processing means only needs to have at least an amplifying function, so that it can be composed of simple discrete components and the like, and can secure a wide dynamic range, It is possible to suppress a decrease in reception sensitivity and the occurrence of a mirror phenomenon or the like.

In the ultrasonic diagnostic apparatus, power is applied to the first reception signal processing means when the ultrasonic pulse Doppler mode is selected, and the second reception signal processing means is supplied when the continuous wave Doppler mode is selected. And a power supply switching means for applying power to the power supply. With this configuration, the supply of power to the reception signal processing means that does not correspond to the operation mode is cut off, so that the S / N ratio can be improved and power consumption can be reduced.

[0015] Further, the ultrasonic diagnostic apparatus is provided with an ultrasonic probe including a plurality of transducers, an acoustic scanning unit for scanning the ultrasonic probe, and an acoustic scanning unit and the ultrasonic probe. A first transmitting unit for transmitting an ultrasonic pulse signal into a living body, a second transmitting unit for transmitting an ultrasonic continuous signal into the living body via an acoustic scanning unit and an ultrasonic probe, and an ultrasonic pulse A transmission switching means for applying either a signal or an ultrasonic continuous signal to the acoustic scanning means, and a reception echo signal corresponding to an ultrasonic pulse signal from within the living body to the ultrasonic probe and the acoustic scanning means. A first reception signal processing means input through the preamplifier, and a reception echo signal corresponding to an ultrasonic continuous signal from the living body through the ultrasonic probe, the acoustic scanning means, and the preamplifier. Receiving signal processing means for inputting the first received signal and first receiving signal processing And configured to include a third reception signal processing means for processing by inputting a signal from the stage and a second reception signal processing unit. With this configuration, the reception echo signal in the ultrasonic pulse Doppler mode is amplified by the first reception signal processing unit, and the reception echo signal in the continuous wave Doppler mode is amplified by the second reception signal processing unit. The received echo signal can be processed with the optimum dynamic range and S / N ratio, and the focal position can be finely set by performing the delay addition processing by the third received signal processing means.

Further, the third reception signal processing means is provided with a parallel delay and addition circuit composed of a plurality of channels, including a delay and addition circuit dedicated to the ultrasonic continuous wave Doppler mode. With this configuration, a wide dynamic range can be secured in the dedicated delay and addition circuit.

Further, the delay addition circuit dedicated to the ultrasonic continuous wave Doppler mode is provided with a circuit which operates in parallel only when the ultrasonic continuous wave Doppler mode is selected. With such a configuration, a wide dynamic range can be secured.

Further, the delay adding circuit for the ultrasonic pulse Doppler mode or the delay adding circuit dedicated to the ultrasonic continuous wave Doppler mode of the delay adding circuit is provided with a circuit for selectively supplying power according to the operation mode. did. With this configuration, the supply of power to the delay addition circuit that does not correspond to the operation mode is cut off, so that the S / N ratio can be improved and power consumption can be reduced.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION
An ultrasonic probe composed of a plurality of transducers, an acoustic scanning unit that scans the ultrasonic probe, and an ultrasonic pulse signal in the living body through the acoustic scanning unit and the ultrasonic probe. First transmitting means for transmitting, second transmitting means for transmitting an ultrasonic continuous signal into the living body via the acoustic scanning means and the ultrasonic probe, and the ultrasonic pulse signal or the ultrasonic signal. Transmission switching means for applying any one of acoustic wave continuous signals to the acoustic scanning means, and a reception echo signal corresponding to the ultrasonic pulse signal from within the living body, the ultrasonic probe and the acoustic scanning means And a first reception signal processing unit input through the preamplification unit, and a reception echo signal corresponding to the ultrasonic continuous signal from inside the living body, the ultrasonic probe, the acoustic scanning unit, A second receiver input via the preamplifier. And an ultrasonic diagnostic apparatus including a signal processing unit. In the ultrasonic pulse Doppler mode, a plurality of probes are driven by a pulse signal from the first transmitting unit, and the received echo signal is converted to a first echo signal. In the continuous wave Doppler mode, the plurality of probes are driven by the continuous sine wave signal from the second transmitting unit, and amplified by the reception signal processing unit.
This has the effect of amplifying the received echo signal by the second received signal processing means.

The second aspect of the present invention is the first aspect.
In the ultrasonic diagnostic apparatus according to the above, the pre-amplifying means,
An input channel corresponding to the reception channel of the ultrasonic continuous signal that operates only in the ultrasonic continuous signal mode, and a plurality of input channels including an input channel that operates in both the ultrasonic continuous signal mode and the ultrasonic pulse Doppler mode And has the effect of performing optimal preamplification in accordance with the operation mode.

The third aspect of the present invention is the first aspect of the present invention.
In the ultrasonic diagnostic apparatus according to the aspect, the second transmitting unit includes a signal generator that gives a phase difference to a plurality of ultrasonic sine wave signals to deflect the ultrasonic waves transmitted from the ultrasonic probe. That is, the transmitting means performs the deflection process.

The fourth aspect of the present invention provides the first aspect.
2. The ultrasonic diagnostic apparatus according to claim 1, wherein the second reception signal processing unit includes a circuit for amplifying and processing the echo signals of the continuous ultrasonic waves of a plurality of channels input through the preamplification unit. This has the effect of enabling processing of signals having a wide dynamic range of continuous ultrasonic waves.

The invention according to claim 5 of the present invention is the invention according to claim 1.
In the ultrasonic diagnostic apparatus described above, when the ultrasonic pulse Doppler mode is selected, power is applied to the first reception signal processing unit, and when the continuous wave Doppler mode is selected, the power is applied to the second reception signal processing unit. It is provided with power supply switching means for applying power, and has the effect of turning off power to unnecessary circuits and improving the S / N ratio.

According to a sixth aspect of the present invention, there is provided an ultrasonic probe comprising a plurality of transducers, acoustic scanning means for scanning the ultrasonic probe, the acoustic scanning means and the ultrasonic scanning means. A first transmitting unit that transmits an ultrasonic pulse signal into a living body via a probe, and a second unit that transmits an ultrasonic continuous signal into the living body via the acoustic scanning unit and the ultrasonic probe. 2
Transmission means, transmission switching means for applying either the ultrasonic pulse signal or the ultrasonic continuous signal to the acoustic scanning means, and a reception echo corresponding to the ultrasonic pulse signal from within the living body A first reception signal processing unit for inputting a signal via the ultrasonic probe, the acoustic scanning unit, and the preamplification unit; and a reception echo signal corresponding to the ultrasonic continuous signal from the living body. A second reception signal processing unit input through the ultrasonic probe, the acoustic scanning unit, and the preamplification unit; a first reception signal processing unit; and a second reception signal processing unit. And a third reception signal processing means for inputting and processing the signals of the first and second signals. In the ultrasonic pulse Doppler mode, a plurality of probes are received by a pulse signal from the first transmission means. Drive and its receiving energy In the continuous wave Doppler mode, a plurality of probes are driven by the continuous sine wave signal from the second transmitting means, and the received echo signals are amplified by the second receiving signal processing means. It has the effect of amplifying by the received signal processing means and finely controlling the focal position by the third received signal processing means.

The invention according to claim 7 of the present invention is the invention according to claim 6
In the ultrasonic diagnostic apparatus according to the aspect, the third reception signal processing unit includes a parallel delay addition circuit including a plurality of channels, including a delay addition circuit dedicated to the ultrasonic continuous wave Doppler mode, By operating the delay addition circuits in parallel, there is an effect that an echo signal of an ultrasonic continuous wave having a wide dynamic range is processed.

The invention according to claim 8 of the present invention is directed to claim 6
In the ultrasonic diagnostic apparatus described above, the delay addition circuit dedicated to the ultrasonic continuous wave Doppler mode includes a circuit that operates in parallel only when the ultrasonic continuous wave Doppler mode is selected, and includes two sets of delays. This has the effect of enabling switching between alternate operation and parallel operation of the adder circuit.

The ninth aspect of the present invention is the eighth aspect of the present invention.
In the ultrasonic diagnostic apparatus according to the above, a circuit for selectively supplying power to the delay addition circuit for the ultrasonic pulse Doppler mode or the delay addition circuit dedicated to the ultrasonic continuous wave Doppler mode of the delay addition circuit according to an operation mode It has the effect of improving the S / N ratio and power consumption.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described in detail with reference to FIGS.

(First Embodiment) A first embodiment of the present invention is directed to an acoustic scanning means for scanning an ultrasonic probe and a first transmitting means for transmitting an ultrasonic pulse signal into a living body. And a second transmission unit, a transmission switching unit for switching between an ultrasonic pulse signal and an ultrasonic continuous signal, and a first reception signal processing unit and a second reception signal processing unit for processing a reception echo signal. It is an ultrasonic diagnostic apparatus.

FIG. 1 is a block diagram showing a configuration of an ultrasonic Doppler blood flow meter in the ultrasonic diagnostic apparatus according to the first embodiment of the present invention. In FIG. 1, an ultrasonic probe 1
Is an ultrasonic transducer for transmitting and receiving ultrasonic waves to and from a living body. The acoustic scanning unit 2 is a unit that scans and drives the ultrasonic probe 1 with an ultrasonic ultrasonic pulse signal. The transmission switching means 5 is a switch for connecting a pulse signal or a continuous wave signal to the acoustic scanning means 5. The high-voltage transmission driving unit 10 is a driving unit for a pulse wave. The CW transmission drive unit 11 is a continuous wave drive unit. Preamplification means-a15 and b-
Reference numeral 16 denotes an amplifier circuit having functions of amplifying, passing, and blocking a received echo signal. The signal processing means 20 is a processing means having a function of changing the amplitude of the received echo signal in the pulse mode with time and simultaneously weighting the amplitude to reduce the side lobe. CW signal processing means 25
Is processing means for amplifying the received echo signal in the continuous wave mode. The power supply switching means 30 is means for operating the signal processing means or the CW signal processing means in accordance with the mode.

The operation of the blood flow meter in the ultrasonic diagnostic apparatus according to the first embodiment of the present invention will be described. The transmission / reception unit includes an ultrasonic probe 1 (indicated by 128 channels in FIG. 1) including a plurality of ultrasonic transducers for electroacoustic conversion. All channels of the ultrasonic transducer 1 are connected to the acoustic scanning means 2. The acoustic scanning means 2 is a switch capable of connecting 128-64 channels. The 128-channel side is connected to all channels of the ultrasonic transducer 1 and the 64-channel is connected to the transmission side.

Transmission switching means 5 is provided so that 64 channels on the transmitting side are connected to the high voltage transmission driving means 10 in the pulse Doppler mode and 32 channels are connected to the CW transmission driving means 11 in the continuous wave Doppler mode. . The high-voltage transmission driving means 10 and the CW transmission driving means 11 generate a transmission driving signal by a control signal from a control circuit (not shown) only in a mode in which the high-voltage transmission driving means 10 and the CW transmission driving means 11 carry.

In the pulse Doppler mode, several high-frequency drive pulse signals are output from the high-voltage transmission drive means 10 in 64 channels.
The signal is applied to the acoustic scanning means 2 via the transmission switching means 5. The acoustic scanning unit 2 excites the ultrasonic probe 1 with a drive pulse signal so that the ultrasonic beam sweeps a region of interest where a pulse Doppler is to be obtained. The excited ultrasonic probe 1 transmits an ultrasonic signal toward a living body and receives the reflected echo signal. Received
The echo signals of 64 channels are again input to the preamplifier-a15 and the preamplifier-b16 via the acoustic scanning means 2. The echo signal amplified to a level that facilitates signal processing in the subsequent stage is input to the signal processing means 20. The signal processing means 20 can temporally control the gain of the echo signal of each channel, and can reduce the side lobe by weighting the amplitude. Since the received echo signal of the pulse Doppler has a narrow dynamic range, the signal does not saturate the preamplifier-a15, the preamplifier-b16 and the signal processing means 20, and a Doppler spectrum free from the Miller phenomenon is obtained. be able to. Although not shown, the output of the signal processing means 20 is subjected to desired analog signal processing via a reception delay addition means, and then to a digital scan converter (DSC), a signal processing circuit for Doppler spectrum, etc. Sent out.

On the other hand, in the continuous wave Doppler mode, a sine wave generating circuit 11a and a phase selecting means 11b as shown in FIG.
The sine wave signal of 32 channels is transmitted from the CW transmission drive means 11 composed of. These sine wave drive signals are
The phase is adjusted so that the ultrasound is deflected toward the region of interest for diagnosis. The drive signal is applied by the transmission switching means 5 to 32 channels on the transmission side of the acoustic scanning means 2. In this embodiment, 32 channels of the 64 channels ultrasonic probe 1 participate in transmission and are excited by the acoustic scanning means 2. The excited ultrasonic probe 1 sends an ultrasonic signal toward the inside of a living body and receives the reflected echo signal through 32 channels dedicated to reception.

The received echo signal is transmitted to the acoustic scanning means 2
The signal is input to the pre-amplifying means-b16 of 32 channels via the CW signal processing means as the second received signal processing means.
Passed to 25. The preamplifier-a15 blocks the received echo signal and transmission signal.

The CW signal processing means 25 has an amplifier circuit and a buffer circuit of 32 channels, and processes a reflected echo signal of a continuous wave Doppler having a wide dynamic range.
Since this processing stage does not need to process the signal temporally, it can be composed of discrete components, and can easily secure a wide dynamic range and a desired gain and S / N ratio. C
The output of the W signal processing means 25 is subjected to desired analog signal processing via a reception delay adding means (not shown), and then to a digital scan converter (DSC), a Doppler spectrum signal processing circuit, and the like. Sent out.

The power of the signal processing means 20 and the power of the CW signal processing means 25 are supplied through a power supply switching means 30. By the power supply switching means 30, the gain adjustment circuit 20 operates in the pulse Doppler mode, and the CW signal processing means 25 operates in the continuous wave Doppler mode.

As described above, in the first embodiment of the present invention, the ultrasonic diagnostic apparatus includes the acoustic scanning means for scanning the ultrasonic probe and the first for transmitting the ultrasonic pulse signal into the living body.
Transmission means and second transmission means, transmission switching means for switching between an ultrasonic pulse signal and an ultrasonic continuous signal, and first and second reception signal processing means for processing a reception echo signal. With this configuration, it is possible to obtain an optimal dynamic range for the received echo signal for both the continuous Doppler method and the pulse Doppler method, and at the same time, increase the circuit scale for processing the echo signal,
Cost increase and power consumption can be suppressed.

(Second Embodiment) A second embodiment of the present invention is directed to an acoustic scanning means for scanning an ultrasonic probe and a first transmitting means for transmitting an ultrasonic pulse signal into a living body. A second transmission unit, a transmission switching unit for switching between an ultrasonic pulse signal and an ultrasonic continuous signal, and a first unit for inputting a received echo signal via an ultrasonic probe, an acoustic scanning unit, and a preamplifier. Receiving signal processing means and second receiving signal processing means,
An ultrasonic diagnostic apparatus including a first reception signal processing unit and a third reception signal processing unit that processes a signal from the second reception signal processing unit.

FIG. 3 is a block diagram showing a configuration of an ultrasonic Doppler blood flow meter of the ultrasonic diagnostic apparatus according to the second embodiment of the present invention. Members corresponding to those already described in FIG. 1 are denoted by the same reference numerals, and detailed description is omitted.
The ultrasonic diagnostic apparatus according to the second embodiment is different from the ultrasonic diagnostic apparatus according to the first embodiment in that a delay addition circuit 40 includes a delay addition 40d-41 dedicated to continuous wave Doppler mode, and a parallel operation mode means 40s. -a, 40s-b.

As described above, the ultrasonic reception echo signal in the pulse Doppler mode or the continuous wave Doppler mode is input to the delay addition circuit 40 via the signal processing means 20 or the CW signal processing means 25. In the pulse Doppler mode, as shown in FIG. 4, it is necessary to finely set and change the focal point of the ultrasonic wave according to the transmission depth of the ultrasonic wave. By performing this operation, the quality of the diagnostic image can be improved. In FIG. 4, A, B, A,
Although ultrasonic focusing points zones of B, A, and B are provided in six layers, actually, focusing points of dozens of layers are provided. This switching of the focal point zone can be performed by the circuit of FIG.

First, in the first A zone, the ultrasonic reception echo signals of 32 channels are delay-synthesized according to the depth by the delay addition circuit 40a, and output via SW-1. While the delay addition circuit 40a is operating, the delay addition circuit 40b
The delay data for the convergence of the next B zone has already been set and prepared, and SW-2 is shut off. In the next B zone, the ultrasonic reception echo signals of 32 channels are delay-synthesized according to the depth by the delay addition circuit 40b and output via the SW-2. As described above, the delay addition circuit 40a and the delay addition circuit 40b operate alternately, so that many focal points can be obtained in the depth direction of the ultrasonic wave. In the pulse Doppler mode, the level of the ultrasonic reception echo signal is smaller than in the continuous wave Doppler mode,
The output signal after the delay addition does not saturate the delay circuit.

In the continuous wave Doppler mode, the ultrasonic reception echo signal passes through the CW signal processing means 25 having a wide dynamic range,
Entered in 40. The delay addition circuit 40 is composed of delay addition circuits a and b, as shown in FIG. Since the received echo signal from the CW signal processing means 25 has a wide dynamic range, the delay addition circuits 40a and 40b operate simultaneously on the received echo signal. In order to improve the dynamic range, SW-1 (40
sa) and SW-2 (40s-b) are turned on.

FIG. 6 shows a detailed block diagram of the delay addition circuit 40a, but the operation of the delay addition circuit 40b is the same except for the sign. Therefore, the delay addition circuit 40
FIG. 6 illustrates a. Although the sub-delay addition circuit displays only channel 1 and channel 32 for the sake of illustration, channels 2 to 31 also exist.

The delay time required in the continuous wave Doppler mode is sufficient for one cycle of the waveform because of handling of continuous waves. For example, when handling an ultrasonic signal of 2 MHz, it is sufficient that the delay time of the reception delay adding circuit for performing electronic focusing is 0.5 μsec. In contrast, the pulse Doppler mode requires a delay time of about 7.5 μsec. Since the received echo information for a cycle of 0.5 μsec or more is repeated for one cycle, a long delay time of 7.5 μsec is not required. Approximately 0.5μsec
Is sufficient. As a delay circuit corresponding to about 0.5 μsec, a sub-delay addition circuit (40d-1
40d-32) and the main delay addition circuit 1 (40d-41).

The received echo signal in the pulse Doppler mode passes through the sub-delay adding circuits (40d-1 to 40d-32) and the cross point switch 40s-36 forming a matrix switch, and is output from the main delay adding circuit. 1 (40d-40),
The main delay addition circuit-2 (40d-41) can secure a desired delay synthesis time.

The 32-channel received echo signals input to the delay adding circuit 40a of FIG. 5 are subjected to 10n by the sub-delay adding circuits (40d-1 to 40d-32) of FIG.
A delay time from 10 nsec to 100 nsec is set in units of sec. The output signal of the sub-delay addition circuit (40d-1 to 40d-32)
Input to the crosspoint switch 40s-35. Although not shown, the output signals are connected to the main delay addition circuit-2 (40d-41) based on the delay data input to the cross point switches 40s-35.

The main delay addition circuit-2 (40d-41) is composed of three 160 nsec delay lines, and
0d-1 to 40d-32) to secure the delay combined time in the continuous wave Doppler mode. Main delay addition circuit-2 (40d-41)
Is subjected to desired analog signal processing and then sent to a digital scan converter (DSC), a signal processing circuit for Doppler spectrum, and the like. Although not shown, the main delay addition circuit-1 has a configuration in which power is applied according to the mode. In the continuous wave Doppler mode, the power supply is stopped and it is not operating,
Since the operation of the mode is not affected by unnecessary circuit noise, the S / N ratio can be improved and power consumption can be reduced.

As described above, according to the second embodiment of the present invention, the ultrasonic diagnostic apparatus includes the acoustic scanning means for scanning the ultrasonic probe and the first for transmitting the ultrasonic pulse signal into the living body.
Transmission means and second transmission means, transmission switching means for switching between an ultrasonic pulse signal and an ultrasonic continuous signal, first reception signal processing means and second reception signal processing means for processing a reception echo signal, With the configuration including the first reception signal processing means and the third reception signal processing means for processing the signals from the second reception signal processing means, both the continuous Doppler method and the pulse Doppler method can be used. An optimum dynamic range can be obtained, and the echo signal can be delayed and added to finely change the focal point of the ultrasonic wave to improve the quality of the diagnostic image.

[0050]

As is clear from the above description of the embodiment, according to the present invention, an ultrasonic diagnostic apparatus is provided with an acoustic scanning means for scanning an ultrasonic probe, and an ultrasonic pulse signal transmitted into a living body. A first transmitting unit and a second transmitting unit, a transmission switching unit for switching between an ultrasonic pulse signal and an ultrasonic continuous signal, a first received signal processing unit for processing a received echo signal, and a second received signal processing And the means
The receiving circuit can be selectively used according to the pulse Doppler mode and the continuous wave Doppler mode, and the optimum dynamic range of the received echo signal can be obtained in both modes. The effect of suppressing occurrence, contributing to improvement of image quality and improvement of a diagnostic function can be obtained, and an effect of being able to be configured with an inexpensive small-scale circuit is obtained.

Further, the preamplifier has a channel that operates only in the ultrasonic continuous signal mode and a channel that operates in both modes, so that optimal preamplification is performed according to the operation mode. The effect that it can be obtained is obtained.

Further, since the second transmitting means is provided with a signal generator for generating a plurality of ultrasonic sine wave signals having a phase difference, in the continuous wave Doppler mode, the ultrasonic wave is generated using a sine wave. Since the probe is driven, there is no harmonic crosstalk from transmission to reception, and the effect of increasing the dynamic range can be obtained.

Further, since the second reception signal processing means is provided with a circuit for amplifying and processing the echo signal of the ultrasonic continuous wave of a plurality of channels, the echo signal of the ultrasonic continuous wave is specially and widely used. An effect is obtained that processing can be performed by a circuit having a dynamic range.

Further, when the ultrasonic pulse Doppler mode is selected, power is applied to the first reception signal processing means,
Since the power supply switching means for applying power to the second reception signal processing means when the continuous wave Doppler mode is selected is provided, the effect of improving the S / N ratio and saving power can be obtained.

Further, the ultrasonic diagnostic apparatus comprises: an acoustic scanning means for scanning an ultrasonic probe; a first transmitting means and a second transmitting means for transmitting an ultrasonic pulse signal into a living body; Transmission switching means for switching between a signal and an ultrasonic continuous signal, first reception signal processing means and second reception signal processing means for processing a reception echo signal, first reception signal processing means, and second reception signal processing And a third reception signal processing means for inputting and processing a signal from the means.
The receiving circuit can be selectively used according to the pulse Doppler mode and the continuous wave Doppler mode, and an optimal dynamic range of the received echo signal can be obtained in both modes. In particular, the third received signal processing means can improve the quality of a diagnostic image. The effect that it can be achieved is obtained.

Further, since the third reception signal processing means is provided with a parallel delay addition circuit composed of a plurality of channels including a delay addition circuit dedicated to the ultrasonic continuous wave Doppler mode, The effect of improving the quality of the diagnostic image can be obtained by finely changing the focal point of the ultrasonic wave by performing the delay addition process.

Further, since the delay addition circuit dedicated to the ultrasonic continuous wave Doppler mode is provided with a circuit which operates in parallel only when the ultrasonic continuous wave Doppler mode is selected, the delay addition circuit in the ultrasonic continuous wave Doppler mode is used. The effect that an echo signal can be processed with a wide dynamic range is obtained.

Also, a configuration is provided in which a delay addition circuit for the ultrasonic pulse Doppler mode of the delay addition circuit or a delay addition circuit dedicated to the ultrasonic continuous wave Doppler mode is provided with a circuit for selectively supplying power according to the operation mode. S
This has the effect of improving the / N ratio and saving power.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of an ultrasonic diagnostic apparatus according to a first embodiment of the present invention;

FIG. 2 is a schematic block diagram of a CW transmission drive unit according to the first embodiment;

FIG. 3 is a schematic block diagram of an ultrasonic diagnostic apparatus according to a second embodiment of the present invention;

FIG. 4 is a diagram for explaining the operation of the delay addition circuit at the time of pulse Doppler in the second embodiment;

FIG. 5 is a block diagram illustrating an operation of the delay and addition circuit according to the second embodiment;

FIG. 6 is a block diagram illustrating a delay addition circuit according to a second embodiment in detail.

FIG. 7 is a schematic block diagram of a conventional ultrasonic diagnostic apparatus.

FIG. 8 is a diagram of Doppler spectrum when the mirror phenomenon appears,

FIG. 9 is a diagram of Doppler spectrum when there is no mirror phenomenon.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ultrasonic probe 2 Acoustic scanning means 5 Transmission switching means 10 High voltage transmission drive means 11 CW transmission drive means 15 Preamplification means a 16 Preamplification means b 20 Signal processing means 25 CW signal processing means 30 Power supply Switching means 40 Delay adding means

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4C301 AA02 BB23 DD01 DD03 DD04 EE04 EE11 EE15 EE17 EE18 EE20 GB02 GB03 HH02 HH25 HH27 HH37 HH38 HH39 HH42 JB11 JB29 JB32 LL04 LL08

Claims (9)

[Claims] An ultrasonic probe comprising a plurality of transducers,
Acoustic scanning means for scanning the ultrasonic probe, first transmitting means for transmitting an ultrasonic pulse signal into a living body via the acoustic scanning means and the ultrasonic probe, and the acoustic scanning means And second transmitting means for transmitting an ultrasonic continuous signal into the living body via the ultrasonic probe, and the acoustic scanning of any one of the ultrasonic pulse signal and the ultrasonic continuous signal A transmission switching means to be applied to the means, and a first inputting a reception echo signal corresponding to the ultrasonic pulse signal from within the living body via the ultrasonic probe, the acoustic scanning means, and the preamplifier. Receiving signal processing means, and a second receiving echo signal corresponding to the ultrasonic continuous signal from within the living body via the ultrasonic probe, the acoustic scanning means, and the preamplifier means Receiving signal processing means. That the ultrasonic diagnostic apparatus. 2. The preamplifier includes: an input channel corresponding to a reception channel of an ultrasonic continuous signal that operates only in an ultrasonic continuous signal mode; and an input channel corresponding to both an ultrasonic continuous signal mode and an ultrasonic pulse Doppler mode. 2. The ultrasonic diagnostic apparatus according to claim 1, further comprising: an input channel that operates on a plurality of input channels; 3. The apparatus according to claim 2, wherein the second transmitting means includes a signal generator for giving a phase difference to a plurality of ultrasonic sine wave signals to deflect the ultrasonic waves transmitted from the ultrasonic probe. The ultrasonic diagnostic apparatus according to claim 1, wherein 4. The apparatus according to claim 1, wherein the second reception signal processing means includes a circuit for amplifying and processing the echo signals of the continuous ultrasonic waves of a plurality of channels input through the preamplification means. The ultrasonic diagnostic apparatus according to claim 1, wherein 5. When the ultrasonic pulse Doppler mode is selected, power is applied to the first reception signal processing means,
2. The ultrasonic diagnostic apparatus according to claim 1, further comprising a power supply switching unit that applies power to the second reception signal processing unit when a continuous wave Doppler mode is selected. 6. An ultrasonic probe comprising a plurality of transducers,
Acoustic scanning means for scanning the ultrasonic probe, first transmitting means for transmitting an ultrasonic pulse signal into a living body via the acoustic scanning means and the ultrasonic probe, and the acoustic scanning means And second transmitting means for transmitting an ultrasonic continuous signal into the living body via the ultrasonic probe, and the acoustic scanning of any one of the ultrasonic pulse signal and the ultrasonic continuous signal A transmission switching means to be applied to the means, and a first inputting a reception echo signal corresponding to the ultrasonic pulse signal from within the living body via the ultrasonic probe, the acoustic scanning means, and the preamplifier. Receiving signal processing means, and a second receiving echo signal corresponding to the ultrasonic continuous signal from within the living body via the ultrasonic probe, the acoustic scanning means, and the preamplifier means Reception signal processing means, and the first reception signal Ultrasonic diagnostic apparatus characterized by comprising a third reception signal processing means for processing by inputting a signal from the second reception signal processing means and physical means. 7. The apparatus according to claim 1, wherein the third reception signal processing means includes a parallel delay addition circuit including a plurality of channels, including a delay addition circuit dedicated to the ultrasonic continuous wave Doppler mode. 7. The ultrasonic diagnostic apparatus according to 6. 8. The ultrasonic adder according to claim 7, wherein the delay addition circuit dedicated to the ultrasonic continuous wave Doppler mode includes a circuit that operates in parallel only when the ultrasonic continuous wave Doppler mode is selected. Ultrasound diagnostic device. 9. A circuit for selectively supplying power to the delay addition circuit for the ultrasonic pulse Doppler mode or the delay addition circuit for the ultrasonic continuous wave Doppler mode of the delay addition circuit according to an operation mode. The ultrasonic diagnostic apparatus according to claim 8, wherein: