JP2005304841A - Continuous wave ultrasonic diagnostic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small-sized, low-cost continuous wave ultrasonic diagnostic device which can be used by switching a phased-array type probe and a pencil type probe, and can obtain a reception signal with a good noise performance when using the pencil type probe. <P>SOLUTION: The ultrasonic diagnostic device has the pencil type probe 11a and the phased-array type probe 11b. The continuous wave of the ultrasonic wave from ultrasonic oscillators which these probes have is transmitted to a specimen, and the blood flow in the specimen is detected by receiving the reflected ultrasonic wave and detecting a Doppler signal. The signal obtained from the reflected ultrasonic wave received when using the pencil type probe 11a is inputted in parallel to a plurality of reception circuits 151-15N for processing the signal obtained from the reflected ultrasonic wave received when using the phased-array type probe 11b, and is added. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ultrasonic diagnostic apparatus, and more particularly, to an ultrasonic diagnostic apparatus that uses a pencil type probe and a phased array type probe by switching.

  Conventionally, an ultrasonic diagnostic apparatus that obtains blood flow information of a subject using a continuous wave (CW) is known, and phased array probes used in such an apparatus are arranged in a line on an ultrasonic wave transmitting / receiving surface. It is possible to switch a large number of ultrasonic transducers, emit ultrasonic waves from these, and display the blood flow information in the subject as an image by the frequency shift of the reflected ultrasonic waves.

  On the other hand, using a pencil-type probe having a pair of transmitting and receiving transducers, a continuous ultrasonic wave is transmitted from the transmitting transducer, and the reflected waves are received by the receiving transducer. An ultrasonic diagnostic apparatus using a pencil probe that detects and displays blood flow information is also known.

  Since the reception processing circuits in the two types of ultrasonic diagnostic apparatuses are common in that the blood flow in the body is detected from the reflected ultrasonic waves by the Doppler effect, it is possible to consider sharing the reception circuit in both apparatuses. is there.

  An ultrasonic diagnostic apparatus using a phased array type probe requires many reception processing circuits. On the other hand, in the ultrasonic diagnostic apparatus using the pencil type probe, the noise performance required for the received signal is very severe compared to the noise performance required for the received signal in the former ultrasonic diagnostic apparatus using the phased array type probe. As a result, the circuit becomes reasonably complicated, large, and expensive. Therefore, if a reception processing circuit used in an ultrasonic diagnostic apparatus using a pencil type probe is used in a reception processing circuit of an ultrasonic diagnostic apparatus using a phased array type probe, it becomes a large and expensive ultrasonic diagnostic apparatus as a whole. End up.

  Therefore, it is conceivable to receive and process the signal obtained with the pencil type probe by the reception processing circuit of the ultrasonic diagnostic apparatus using the phased array type probe, but the circuit required for the phased array type probe as described above. The noise performance of this type is not as good as that of the pencil type probe. Therefore, if one of the receiving circuits is used in an ultrasonic diagnostic apparatus using a pencil type probe, good results cannot be obtained from the viewpoint of noise performance. .

  As described above, in a continuous wave ultrasonic diagnostic apparatus that switches between a phased array type probe and a pencil type probe, if the latter receiving circuit is used in the former receiving circuit, the size and cost of the ultrasonic diagnosis are increased. On the other hand, if the former reception processing circuit is to use the latter reception processing, a satisfactory received signal cannot be obtained in terms of noise performance when using a pencil type probe.

  The present invention has been made in view of the above-described conventional problems, and can be used by switching between a phased array type probe and a pencil type probe. When a pencil type probe is used, a received signal with good noise performance is obtained. An object of the present invention is to provide a continuous wave ultrasonic diagnostic apparatus which is obtained and is small and inexpensive.

  According to the first aspect of the present invention, a pencil type probe and a phased array type probe are provided, and a continuous wave of ultrasonic waves is transmitted from the ultrasonic transducers included in these probes to the subject, and the reflected ultrasonic waves are received. An ultrasonic diagnostic apparatus for detecting a signal and detecting blood flow in the subject, wherein a plurality of receiving circuits for processing a signal obtained from the reflected ultrasonic wave received when using the phased array probe, Provided is a continuous wave ultrasonic diagnostic apparatus characterized in that signals obtained from reflected ultrasonic waves received when using the pencil type probe are input and added in parallel.

  According to claim 2 of the present invention, a pencil-type probe having a transmitting ultrasonic transducer for transmitting ultrasonic waves and a receiving ultrasonic transducer for receiving ultrasonic waves, and an ultrasonic wave arranged in a line to transmit ultrasonic waves. A phased array type probe having a plurality of ultrasonic transducers to receive, a plurality of receiving circuits for processing signals obtained from reflected ultrasonic waves received by the ultrasonic transducers of the phased array type probe, and a plurality of these When the pencil-type probe is used, the signal obtained from the reflected ultrasonic wave received by the receiving ultrasonic transducer when the phasing addition processing circuit that performs the phasing addition by inputting the output of the receiving circuit is used. There is provided a continuous wave ultrasonic diagnostic apparatus comprising: a plurality of changeover switches that input in parallel to a plurality of receiving circuits of a part of the plurality of receiving circuits.

  According to a third aspect of the present invention, in the continuous wave ultrasonic diagnostic apparatus according to the second aspect, when the pencil probe is used, an output of a signal input to the receiving circuit via the plurality of changeover switches. Are further added to each other.

  According to a fourth aspect of the present invention, in the continuous wave ultrasonic diagnostic apparatus according to the third aspect, the phasing addition processing circuit is stopped when the pencil probe is used.

  According to claim 5 of the present invention, a pencil type probe having a transmitting ultrasonic transducer for transmitting ultrasonic waves and a receiving ultrasonic transducer for receiving ultrasonic waves, and an ultrasonic wave arranged in a line are arranged. A phased array type probe having a plurality of ultrasonic transducers to be received, and a plurality of AD converters for analog-to-digital conversion of signals obtained from reflected ultrasonic waves received by the ultrasonic transducers of the phased array type probe A sigma delta modulator as a part, a plurality of decimators that receive each of the outputs of the plurality of sigma delta modulators, and a phasing addition processing circuit that inputs the outputs of these decimators and performs shaped addition When the pencil type probe is used, a signal obtained from the reflected ultrasonic wave received by the receiving ultrasonic transducer is converted to a part of the plurality of receiving circuits. And adding the outputs of the sigma delta modulators input in parallel to each other, and inputting the output of the adder circuit to one of the plurality of decimators. And a control means for stopping the continuous wave ultrasonic diagnostic apparatus.

  According to the present invention, it is possible to switch between a phased array type probe and a pencil type probe, and when a pencil type probe is used, a received signal with good noise performance can be obtained, and a small and inexpensive continuous wave ultrasonic diagnosis is possible. There is an effect that a device can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration example of one embodiment of the present invention. This ultrasonic diagnostic apparatus has two types of probes, a pencil type probe 11a and a phased array type probe 11b. In the figure, only an ultrasonic reception system circuit is shown, and a transmission system circuit is omitted. It is. The pencil type probe 11a has an ultrasonic transducer 12t for transmitting juxtaposed ultrasonic waves and an ultrasonic transducer 12r for receiving ultrasonic waves, and the phased array type probe 11b is arranged in a line. There are N, for example, 64 ultrasonic transducers 131 to 13N provided.

  The ultrasonic diagnostic apparatus further includes mode changeover switches 141 to 144 for selectively connecting the ultrasonic transducer 12r of the pencil probe 11a and the ultrasonic transducers 131 to 13N of the phased array probe 11b, The N-channel receiving circuits 151 to 15N connected to the mode changeover switches 141 to 144 and the ultrasonic transducers 135 to 13N, respectively, and the I output signal and the Q output signal processed by these receiving circuits are input. The phasing / addition processing circuit 16 and a display circuit (not shown) that inputs a signal processed by the phasing / addition processing circuit 16 and displays the inside of the subject.

  Each of the receiving circuits 151 to 15N includes a low-noise amplifier 17a that amplifies the ultrasonic reflected signal received by the ultrasonic transducer, and a low-pass filter 17b that passes the signal amplified by the low-noise amplifier 17a through a low band. A multiplier 18I that multiplies the output of the low-pass filter 17b and the I clock signal, and a multiplier 18Q that multiplies the output of the low-pass filter 17b and the Q clock signal (which is 90 degrees out of phase with the I clock signal). Bandpass filters 19I and 19Q that pass through the output signals of the multipliers 18I and 18Q, programmable gain amplifiers 20I and 20Q that amplify the bandpass filters 19I and 19Q, and programmable gain amplifiers 20I and 20Q, respectively. AD converters 21I and 21Q for converting each analog signal into a digital signal; Consisting of.

  Next, the operation of this ultrasonic diagnostic apparatus will be described. First, a case where blood flow information in the body of a subject is obtained using the phased array type probe 11b (phased array mode) will be described. At this time, the receiving circuits 151 to 154 are connected to the ultrasonic transducers 131 to 134 by the mode changeover switches 141 to 144. Therefore, drive pulses are applied to the ultrasonic transducers 131 to 13N from an ultrasonic drive circuit (not shown), and reflected ultrasonic waves from within the subject are received by these ultrasonic transducers 131 to 13N. The received reflected ultrasonic signal (analog signal) is input to the receiving circuits 151 to 15N via the mode changeover switches 141 to 144 or directly.

  In each receiving circuit, the signal is amplified by a low noise amplifier 17a, passes through a low-pass filter 17b, and is multiplied by an I clock signal and a Q clock signal in multipliers 18I and 18Q, respectively, and is divided into an I component and a Q component. The signals are passed through the pass filters 19I and 19Q, amplified by the programmable gain amplifiers 20I and 20Q, converted into digital signals by the AD converters 21I and 21Q, and digitally phased and added by the phased and added processing circuit 16.

  On the other hand, when blood flow is detected using the pencil type probe 11a (pencil mode), the mode changeover switches 141 to 144 are tilted upward, and the receiving circuits 151 to 4 receive ultrasonic waves for receiving the pencil type probe 11a. Connected to the vibrator 12r.

  A drive signal output from an ultrasonic drive signal generator (not shown) is applied to the transmission ultrasonic transducer 12t of the pencil probe 11a, and an ultrasonic continuous wave is transmitted to the subject. The reflected ultrasonic wave from the subject is received by the receiving ultrasonic transducer 12r. The reflected ultrasonic waves received by the ultrasonic transducer 12r are input to the receiving circuits 151 to 154 in parallel via the mode changeover switches 141 to 144.

  The reflected ultrasonic signals input to the receiving circuits 151 to 154 are processed in the same manner as in the phased array mode. However, at this time, the same reflected ultrasonic signals received by the ultrasonic transducer 12r are input to the receiving circuits 151 to 154 of the channels 1 to 4 and processed, added by the phasing addition processing circuit 16, and output. Is done.

  Therefore, the signal received by the ultrasonic transducer 12r is quadrupled. However, when there is no correlation between the noises of the respective circuits, the noise is √4 = 2, and the increase in circuit noise is doubled to reduce the signal. Can be quadrupled.

  Thus, in the pencil mode, it is possible to increase the signal while suppressing noise by inputting the reflected signal in parallel to the plurality of receiving circuits. In general, if an ultrasonic signal is input in parallel to an M channel receiving circuit, the signal is ideally M times and the circuit noise is √M times. Therefore, if the number of channels of the receiving circuits that are input in parallel is increased, the signal for noise can be increased, but for this purpose, it is necessary to increase the number of mode changeover switches that reduce noise, and the cost increases. Naturally there is a limit to the increase. Usually, if the number of channels is about 4, 5, the signal-to-noise ratio can be increased sufficiently and the cost can be kept low.

  Next, another embodiment of the present invention will be described with reference to the drawings. This embodiment is an example of a configuration in which an M channel receiving circuit is provided as shown in FIG. 2 and that M channel is used in the pencil mode.

  Numbers 21a, 21b, 22t, and 22r correspond to numbers 11a, 11b, 12t, and 12r in FIG. 1, and vibrators 231, 232, and 23N correspond to vibrators 131, 132, and 13N in FIG. In this example, in the pencil mode, the reflected ultrasonic signal received by the ultrasonic transducer 22r is input to the receiving circuits 251 to 25M by the M mode changeover switches 241 to 24M.

  Each of the receiving circuits 251 to 25N corresponds to each of the receiving circuits 151 to 15N in FIG. 1, and each receiving circuit has the same circuit configuration as that shown in the receiving circuit 151 in FIG. The I output and Q output of each of the receiving circuits 251 to 25N are input to the phasing addition processing circuit 26. On the other hand, the I output and Q output of the receiving circuits 251 to 25M used in the pencil mode are input to the adding circuits 27I and 27Q, respectively, and input to the multiplexer 28 together with the I output and Q output of the phasing addition processing circuit 26. The phasing addition processing circuit 26 operates in the phased array mode but stops in the pencil mode, and the multiplexer 28 selects either the adder 27I, 27Q output or the phasing addition circuit 26 output as the final output.

  According to this embodiment of the present invention, since the operation of the phasing addition processing circuit 26 is stopped in the pencil mode, a correlated noise component common to the analog channel unit (receiving circuit unit) is reduced. There is an advantage that it can be greatly suppressed.

  Next, still another embodiment of the present invention in which a sigma delta (ΣΔ) type AD converter is used as the AD converter of the phasing addition processing circuit will be described. The basic configuration of this ΣΔ AD converter is as shown in FIG. That is, an analog input is input to the sigma delta modulator 31, and this 1-bit output is input to the decimator 32. The L-bit output of the decimator 32 is input to the low-pass filter 33, and an L-bit digital signal is output from the low-pass filter 33.

  FIG. 4 shows a configuration example of a part of the ultrasonic diagnostic apparatus when such a ΣΔ AD converter is used. In the figure, in the pencil mode, a signal received by the ultrasonic transducer for reception of the pencil probe is input in common to M ΣΔ modulators 411 to 41M. The outputs of the ΣΔ modulators 411 to 41M are 1-bit signals, and the outputs of the ΣΔ modulators 411 to 41M are added by the adder circuit 42 and used as one input of the multiplexer 43. The other input of the multiplexer 43 is the output of the ΣΔ modulator 411, and the output of the adder circuit 43 is input to a decimator 441 having a K-bit output.

  On the other hand, the outputs of the ΣΔ modulators 412 to 41M are directly input to the decimators 442 to 44M. Decimators 442 to 44M with L-bit output stop operating in the pencil mode. Accordingly, in the pencil mode, the outputs of the ΣΔ modulators 411 to 41M are added by the adder circuit 42 and input to the multiplexer 43, and are separately taken out through the decimator 441.

  In the phased array mode, the output of the decimator 441 is input to the phasing addition processing circuit at the subsequent stage.

  From the output of the ΣΔ modulator to the final output, the signal develops from a high rate and low resolution to a low rate and high resolution. In the application of the present invention, outputs from the same input are added by the number of channels in order to realize a required equivalent low noise characteristic. Here, since both the decimator and the low-pass filter are linear systems, the effect is the same as the result of adding the final outputs, respectively, when applied to the signal after addition. Therefore, in this embodiment, focusing on this point, the pencil mode adder is placed in front of the decimator, and it is possible to minimize the operation of the digital part that can be a noise source for the analog part by making the decimator common. Become.

  In this embodiment, in the pencil mode, addition is performed before the decimator and the added data is input to the decimator 441, and the output of the decimator 441 is sent to a system that bypasses the phasing addition processing circuit.

  In this embodiment of the present invention, with such a configuration, one decimator is sufficient for each I / Q, and the operation of the remaining decimators can be stopped. Thereby, further reduction of noise having a correlation between channels can be expected. Further, in this case, since the input of the adder circuit is a signal having a small bit (for example, 1 bit) width, there is an effect that the circuit can be realized on a smaller scale as compared with adding the outputs of the decimators.

The figure which shows the structural example of one Embodiment of this invention. The figure which shows the structural example of other embodiment of this invention. The figure which shows the structural example of the sigma delta converter used in other embodiment of this invention. The figure which shows the one part structural example of other embodiment of this invention.

Explanation of symbols

11a, 21a ... pencil type probe,
11b, 21b ... Phased array type probe,
12t, 12r, 131 to 13N, 22t, 22r, 231 to 23N ... ultrasonic transducer,
141-144, 241-24M... Mode changeover switch,
151-15N, 251-25N... Receiving circuit,
16, 26 ... phasing addition processing circuit,
17a ... Low noise amplifier,
17b, 33 ... low-pass filter,
18I, 18Q ... multipliers,
19I, 19Q ... band pass filters,
20I, 20Q... Programmable gain amplifier,
21I, 21Q ... AD converter,
27I, 27Q, 42... Addition circuit,
28, 43 ... Multiplexer,
31, 411 to 41M... Sigma delta (ΣΔ) modulator,
32,441-44M ... Decimator.

Claims (5)

A pencil-type probe and a phased array-type probe, and a continuous wave of ultrasonic waves is transmitted to the subject from these ultrasonic transducers, and the reflected ultrasound is received to detect a Doppler signal, and blood in the subject is detected. An ultrasonic diagnostic apparatus for detecting a flow,
A plurality of receiving circuits that process signals obtained from the reflected ultrasound received when using the phased array type probe are connected in parallel to signals received from the reflected ultrasound received when using the pencil type probe. A continuous wave ultrasonic diagnostic apparatus characterized by inputting and adding. A pencil type probe having an ultrasonic transducer for transmitting ultrasonic waves and an ultrasonic transducer for receiving ultrasonic waves;
A phased array type probe having a plurality of ultrasonic transducers arranged in a line and transmitting and receiving ultrasonic waves;
A plurality of receiving circuits for processing signals obtained from reflected ultrasonic waves received by the ultrasonic transducer of the phased array probe;
A phasing addition processing circuit for performing phasing addition by inputting the outputs of the plurality of receiving circuits;
When the pencil probe is used, a plurality of changeover switches for inputting in parallel a signal obtained from the reflected ultrasonic wave received by the receiving ultrasonic transducer to a plurality of receiving circuits of a part of the plurality of receiving circuits. When,
A continuous wave ultrasonic diagnostic apparatus comprising:   3. The continuous wave ultrasonic wave according to claim 2, further comprising an adding circuit that adds outputs of signals input to the receiving circuit via the plurality of changeover switches when the pencil probe is used. Diagnostic device.   4. The continuous wave ultrasonic diagnostic apparatus according to claim 3, wherein when the pencil type probe is used, the phasing addition processing circuit is stopped. A pencil type probe having an ultrasonic transducer for transmitting ultrasonic waves and an ultrasonic transducer for receiving ultrasonic waves;
A phased array type probe having a plurality of ultrasonic transducers arranged in a line and transmitting and receiving ultrasonic waves;
A sigma delta modulator as a part of a plurality of AD converters for analog-digital conversion of signals obtained from reflected ultrasonic waves received by the ultrasonic transducer of the phased array probe;
A plurality of decimators each receiving the output of each of the plurality of sigma delta modulators;
A phasing addition processing circuit that inputs the outputs of these decimators and performs shaped addition,
When the pencil-type probe is used, signals obtained from the reflected ultrasonic waves received by the receiving ultrasonic transducer are input in parallel to a plurality of sigma delta modulators that are part of the plurality of receiving circuits. An adder circuit for adding the outputs of the sigma delta modulators input in parallel;
Control means for inputting the output of the adder circuit to one of the plurality of decimators and stopping the other decimators;
A continuous wave ultrasonic diagnostic apparatus comprising:

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