JP3886366B2 - Ultrasonic diagnostic equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ultrasonic diagnostic apparatus, and in particular, processes a normal B mode, an SCW Doppler mode, and a high frequency mode with one delay addition system.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an ultrasonic diagnostic apparatus having a deflectable continuous wave (hereinafter abbreviated as SCW) Doppler function is disclosed in Japanese Patent Publication No. 10-506801.
[0003]
FIG. 11 is a block diagram showing a configuration of a conventional ultrasonic diagnostic apparatus. In FIG. 11, a conventional ultrasonic diagnostic apparatus includes a probe 21 (comprising transducers 100a to 100d), a transmission beam former 22, a first reception beam former 23, phase detectors 24 and 25, a phase shifter 26, 27, adders A11 and A12, A / D converters A / D11 and A / D12, a phase shift data generator 29, a frequency analysis unit 30, a B-mode processing unit 31, a display unit 32, and the like.
[0004]
The phase shifters 26 and 27 and the adders A11 and A12 constitute a second reception beamformer 28. Recently, as the first beamformer 23, a digital beamformer that performs A / D conversion of a received signal and converts the received signal into a digital signal and then performs a delay addition has been widely used.
[0005]
[Problems to be solved by the invention]
However, the conventional example described above has a problem that the calculation function of the first reception beamformer for the RF channel cannot be used in the SCW Doppler, and the circuit scale increases.
[0006]
In addition, there is a limit to the A / D conversion frequency. For this reason, when a high frequency is used, there is a problem that the echo signal is turned back.
[0007]
[Means for Solving the Problems]
In order to solve the above-described conventional problems, the present invention does not involve whether the phase detector, the A / D converter, and the input of the A / D converter are input via the phase detector before the reception beamformer. The baseband detection is shifted to an intermediate frequency lower than the frequency of the echo signal when using a high frequency when SCW Doppler is used, and the switch is switched to the phase at a lower echo frequency. By connecting so as not to go through the detector, an ultrasonic diagnostic apparatus that does not require a second reception beamformer and can cope with a high frequency is provided.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS.
[0010]
(First embodiment)
FIG. 1 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to the first embodiment of the present invention. In FIG. 1, an ultrasonic diagnostic apparatus includes a probe 21 (comprising transducers 100a to 100d), a transmission beamformer 22, a MUX / adder 101 for distributing and adding echo signals received by the transducer, and a phase. Detectors 24 and 25 (consisting of mixers M1 to M4 and bandpass filters BPF1 to BPF4), a signal generator 34 for supplying a reference signal to the phase detectors 24 and 25, a MUX / adder 101, a phase detector Switches SW1 to SW4 for selecting one of the devices 24 and 25, a reception beamformer 23, a phase shift data generator 33 for generating a signal for controlling a phase shift angle in the reception beamformer, a frequency analysis unit 30, A B-mode processing unit 31, a display unit 32, and the like are included.
[0011]
Next, the operation of the ultrasonic diagnostic apparatus according to this embodiment will be described. First, in the normal B mode, as shown in FIG. 2A, the inside of the MUX / adder 101 is connected, and the switches SW1 to SW4 are connected to a, so that the transducers 100a to 100d receive the signals. The echo signal is input as it is to the reception beamformer 23, processed in B mode, and displayed on the display unit 32.
[0012]
Next, the operation in the SCW Doppler mode will be described. In the SCW Doppler mode, a continuous wave is transmitted by half the transducers of the probe 21, here the transducers 100a and 100b, and echo signals are received by the transducers 100c and 100d.
[0013]
In the SCW Doppler mode, the MUX / adder 101 is connected as shown in FIG. Therefore, echo signals received by the transducers 100 c and 100 d are input to the phase detectors 24 and 25. Further, the signal generator 34 outputs a signal having the same frequency that is 90 degrees out of phase with respect to the echo signal with respect to the echo signal.
[0014]
The output signals of the phase detectors 24 and 25 are input to the reception beam former 23 via the switches SW1 to SW4. As shown in FIG. 3, the reception beamformer 23 includes delay units DL1 to DL4, multipliers MP1 to MP4, and adders ADD1 to ADD3. After being delayed by an amount determined by the delay units DL1 to DL4, the multipliers MP1 to MP4 multiply by the data (weighting coefficient) of the phase shift data generator 33 and add by the adders ADD1 to ADD3. The At this time, two adjacent signals, for example, the output of the switch SW1 and the output of the switch SW2 are two signals of quadrature detection, and a signal having an arbitrary phase can be created by adding an appropriate weight to these signals. Is possible.
[0015]
The output of the reception beam former 23 is subjected to frequency analysis by the frequency analysis unit 30 and displayed on the display unit 32.
[0016]
Finally, the operation when the echo signal frequency is high will be described. In this case, the MUX / adder 101 is connected as shown in FIG. 2C, and signals of two adjacent channels are added and input to the phase detectors 24 and 25. The signal generator 34 outputs a signal for shifting the echo signal to a lower frequency. For example, when the echo signal is 20 MHz, the output frequency of the signal generator 34 is 15 MHz, and the frequency difference signal 5 MHz is output from the phase detectors 24 and 25 (the 35 MHz sum signal is cut by BPF1 to BPF4). )
[0017]
The output signals of the phase detectors 24 and 25 are input to the reception beam former 23 via the switches SW1 to SW4. As shown in FIG. 3, the reception beamformer 23 includes delay units DL1 to DL4, multipliers MP1 to MP4, and adders ADD1 to ADD3. After being delayed by an amount determined by the delay units DL1 to DL4, the multipliers MP1 to MP4 multiply by the data (weighting coefficient) of the phase shift data generator 33 and add by the adders ADD1 to ADD3. The At this time, two adjacent signals, for example, the output of the switch SW1 and the output of the switch SW2 are two signals of quadrature detection, and a signal having an arbitrary phase can be created by adding an appropriate weight to these signals. Is possible.
[0018]
The output of the reception beamformer 23 is displayed on the display unit 32 through the B mode processing unit 31.
[0019]
As described above, the ultrasonic diagnostic apparatus according to the first embodiment of the present invention can process the normal B mode, the SCW mode, and the high echo frequency mode with the same reception beamformer 23. is there.
[0020]
(Second Embodiment)
FIG. 4 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to the second embodiment of the present invention. 4, the ultrasonic diagnostic apparatus includes a probe 21 (comprising transducers 100a to 100d), a transmission beamformer 22, a MUX 111 that distributes and adds echo signals received by the transducer, a phase detector 124, 125 (consisting of mixers M1 to M4 and bandpass filters BPF1 to BPF4), one of the signal generator 134, MUX111, and phase detectors 124, 125 for supplying a reference signal to the phase detectors 124, 125 Switches SW1 to SW4 for selecting signals, a reception beamformer 123, a phase shift data generator 133 for generating a signal for controlling a phase shift angle in the reception beamformer 123, an MUX and adder 135, a frequency analysis unit 130, B The mode processing unit 131, the display unit 32, and the like are included.
[0021]
Next, the operation of the ultrasonic diagnostic apparatus according to this embodiment will be described. First, in the normal B mode, as shown in FIG. 5A, the inside of the MUX 111 is connected, and the switches SW1 to SW4 are connected to a. As a result, the echo signals received by the transducers 100a to 100d remain as they are. The signal is input to the reception beam former 123, processed in B mode, and displayed on the display unit 32. The MUX and adder 135 are in a state where the input a and output a, and the input b and output b are connected.
[0022]
Next, the operation in the SCW Doppler mode will be described. In the SCW Doppler mode, a continuous wave is transmitted by half the transducers of the probe 21, here the transducers 100a and 100b, and echo signals are received by the transducers 100c and 100d.
[0023]
In the SCW Doppler mode, the MUX 111 is connected as shown in FIG. Therefore, the echo signal received by the transducer 100c is input to the mixers M1 and M2 of the phase detector 124, and the echo signal received by the transducer 100d is input to the mixers M3 and M4 of the phase detector 125. The signal generator 134 outputs a signal having the same frequency that is 90 degrees out of phase with respect to the echo signal with respect to the echo signal. The following operations are the same as those in the first embodiment described above. The MUX and adder 135 are in a state where the input a and output a, and the input b and output b are connected.
[0024]
Finally, the operation when the echo signal frequency is high will be described. The connections of the MUX 111 are connected as shown in FIG. 5C, and the signals of the transducers 100a to 100d are input to the mixers M1 to M4 of the phase detectors 124 and 125, respectively. The signal generator 134 outputs a signal for shifting the echo signal to a lower frequency. For example, when the echo signal is 20 MHz, the output frequency of the signal generator 134 is 15 MHz, and the frequency difference signal 5 MHz is output from the phase detectors 124 and 125 (the 35 MHz sum signal is cut by BPF1 to BPF4). )
[0025]
Output signals from the phase detectors 124 and 125 are input to the reception beamformer 123 via the switches SW1 to SW4. As shown in FIG. 6, the reception beamformer 123 includes delay units DL-A and DL-B, multipliers MP-A and MP-B, adders ADD-A and ADD-B, and has a small azimuth. In order to receive two reception beams of difference, two delay adders are provided.
[0026]
After being delayed by an amount determined by the delay units DL-A and DL-B, the multipliers MP-A and MP-B are multiplied based on the data (weighting coefficient) of the phase shift data generator 133, Adders are added by adders ADD-A and ADD-B. At this time, the delay amounts of the delay unit DL-A and the delay unit DL-B are set so as to have a difference corresponding to a quarter wavelength of the input signal. For this reason, the signals of the delay units DL-A and DL-B are equivalent to two signals of quadrature detection in the vicinity of the frequency, and signals having an arbitrary phase can be obtained by adding appropriate weights thereto. Can be created.
[0027]
The inside of the MUX and the adder 135 are connected as shown in FIG. 7, and the input a and the input b are added to become an output a. The output of the reception beamformer 123 is displayed on the display unit 32 via the MUX, the adder 135 and the B mode processing unit 131.
[0028]
As described above, the ultrasonic diagnostic apparatus according to the second embodiment of the present invention can process the normal B mode, SCW mode, and high echo frequency mode with the same reception beamformer 123. In this embodiment, since a plurality of transducers are not bundled, there is no deterioration in the shape of the received beam.
[0029]
(Third embodiment)
FIG. 8 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to the third embodiment of the present invention. The ultrasonic diagnostic apparatus according to the third embodiment of the present invention shown in FIG. 8 analyzes the echo signal received by the reception beamformer 123 and optimally sets the difference in delay amount in the parallel reception delay unit. Except for the point that the frequency analyzer 140 is provided, the rest is the same as that of FIG. 4 described for the second embodiment. Therefore, differences from the second embodiment will be described.
[0030]
In the above-described second embodiment, in the operation when the echo signal frequency is high, the role of quadrature detection is achieved by changing the delay amount by one-fourth of the echo frequency with respect to one of the parallel reception beamformers with respect to the other. However, it has been known that the frequency of the echo varies depending on the subject and the depth of further examination depending on the examination site.
[0031]
Therefore, in the third embodiment of the present invention, in the operation when the echo signal frequency is high, in order to optimize this, the echo signal received by the reception beamformer 123 is analyzed by the center frequency analyzer 140 and parallel reception is performed. The difference in delay amount in each delay unit is optimally set.
[0032]
(Fourth embodiment)
FIG. 9 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to the fourth embodiment of the present invention. The ultrasonic diagnostic apparatus according to the fourth embodiment of the present invention shown in FIG. 9 analyzes the echo signal received by the reception beamformer 123 and optimally sets the difference in delay amount in the parallel reception delay unit. Except for the point that an output frequency controller 141 for controlling the output frequency of the frequency analyzer 140 and the signal generator 134 is provided, the rest is the same as FIG. 4 described for the second embodiment. Therefore, differences from the second embodiment will be described.
[0033]
In the above-described second embodiment, in the operation when the echo signal frequency is high, the role of quadrature detection is achieved by changing the delay amount by one-fourth of the echo frequency with respect to one of the parallel reception beamformers with respect to the other. However, it has been known that the frequency of the echo varies depending on the subject and the depth of further examination depending on the examination site.
[0034]
Therefore, in the fourth embodiment of the present invention, in the operation when the echo signal frequency is high, in order to optimize this, the echo signal received by the reception beamformer 123 is analyzed by the center frequency analyzer 140 and the output frequency control is performed. The output frequency of the signal generator 134 is optimally set so that the intermediate frequency input to the reception beam former 123 by the generator 141 is constant.
[0035]
(Fifth embodiment)
FIG. 10 is a block diagram showing a configuration of a reception beamformer which is a part of an ultrasonic diagnostic apparatus according to the fifth embodiment of the present invention. A reception beamformer 223 which is a part of an ultrasonic diagnostic apparatus according to the fifth embodiment of the present invention shown in FIG. 10 is a Hilbert converter 150 and a switch 151 for selecting whether or not to allow the Hilbert converter 150 to pass. Except for this point, the rest of the configuration is the same as in FIG. 6 for the reception beamformer 123 according to the second embodiment. Therefore, a difference from the reception beamformer 123 in the second embodiment will be described.
[0036]
In the receive beamformer 123 in the second embodiment described above, one of the parallel receive beamformers has played the role of quadrature detection by changing the delay amount by ¼ wavelength of the echo frequency. It is known that the frequency of the echo varies depending on the depth of further examination depending on the subject and the examination site.
[0037]
Therefore, in order to optimize the reception beamformer 223 according to the fifth embodiment of the present invention, by providing the Hilbert transformer 150 at the output of one delay line, the multiplier MP− is used regardless of the echo frequency. The signals input to A and the multiplier MP-B are always orthogonal.
[0038]
【The invention's effect】
As is apparent from the description of the above embodiment, the present invention is based on the combination of a switch, an A / D converter, a phase detector, and a receiving beamformer, and uses all of the normal B mode, SCW Doppler mode, and high frequency. Can be realized in one system, and an ultrasonic diagnostic apparatus having a reception beamformer with a small circuit scale can be realized.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to a first embodiment of the present invention;
FIG. 2 is an explanatory diagram showing internal connections of the MUX / adder according to the first embodiment of the present invention;
FIG. 3 is an explanatory diagram showing the internal structure of the reception beamformer according to the first embodiment of the invention;
FIG. 4 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to the second embodiment of the present invention;
FIG. 5 is an explanatory diagram showing internal connections of the MUX according to the second embodiment of the present invention;
FIG. 6 is an explanatory diagram of an internal structure of a parallel reception beamformer according to a second embodiment of the invention;
FIG. 7 is an explanatory diagram showing internal connections of a MUX and an adder according to the second embodiment of the present invention.
FIG. 8 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to the third embodiment of the present invention;
FIG. 9 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to the fourth embodiment of the present invention;
FIG. 10 is an explanatory diagram of the internal structure of a parallel reception beamformer according to a fifth embodiment of the invention;
FIG. 11 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to a conventional embodiment.
[Explanation of symbols]
21 Probe 22 Transmission beam former 23, 123 Reception beam former 24, 25, 124, 125 Phase detector 28 Second reception beam former 30, 130 Frequency analysis unit 31, 131 B mode processing unit 32 Display unit 33, 133 Phase Shift data generators 34 and 134 Signal generators 100a to 100d Transducer 101 MUX and adder 111 MUX
135 MUX and Adder 140 Center Frequency Analyzer 141 Output Frequency Controller A11-12 Adder ADD1-3, ADD-A-B Adder A / D1-2 A / D Converter BPF1-4 Band Pass Filter DL1-4 DL-A to B Delay devices M1 to 4 Mixers MP1 to 4, MP-A to B Multipliers SW1 to SW4, SW151 switch

Claims (1)

A phase detector for phase-detecting the RF signal of the probe; an A / D converter for discretizing the output of the phase detector; and a receive beamformer for delay-adding the output discretized by the A / D converter And a signal generator for generating a reference signal to be input to the phase detector, and a switch for selecting whether to input the A / D converter through the phase detector or not. When inputting a high-frequency echo that causes aliasing with respect to the frequency discretized by the A / D converter , the phase detector converts the echo to an intermediate frequency, and at a lower echo frequency, the switch is turned on. An ultrasonic diagnostic apparatus, which is connected so as not to pass through a phase detector and converts echoes to baseband by the phase detector when a continuous wave is used.

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