JP2005168902A - Ultrasonic diagnostic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic diagnostic device composed of a small number of components capable of phasing and adding reception signals from a plurality of vibrators in a simpler circuit and by less control. <P>SOLUTION: For the reception signals obtained in the vibrators 103 and 104 of a sub array 101 inside a two-dimensional array 100, phasing and addition are performed by performing phasing by varying a phase amount by variable phase shifters 107 and 108 inside a sub beam former 119 respectively and adding output signals from the variable phase shifters 107 and 108 by an adder 109. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ultrasonic diagnostic apparatus that performs electronic scanning by transmitting and receiving an ultrasonic beam using a two-dimensional array in which a plurality of transducers are two-dimensionally arranged.

  The principle of an electronic scanning ultrasonic diagnostic apparatus that obtains two-dimensional information in the body by repeatedly transmitting and receiving ultrasonic waves in the body using an array transducer is well known. In recent years, color flow blood flow imaging devices, composite scanning, and two-dimensional scanning techniques have been developed, and the number of transducers for obtaining signals at a time has increased dramatically. Therefore, the circuit portion for receiving the signal obtained by the vibrator and performing beam forming also increases. Therefore, for example, a method for reducing the scale of the receiving circuit by a method as disclosed in Patent Document 1 is proposed. Has been.

  FIG. 7 is a schematic block diagram showing a configuration example of such a conventional ultrasonic diagnostic apparatus. In FIG. 7, the conventional ultrasonic diagnostic apparatus includes a two-dimensional array 100, sub-beamformers 119 and 120 for phasing and adding received signals from sub-arrays 101 and 102 constituting the two-dimensional array 100, a sub-beamformer 119, Main beamformer 110 for phasing and adding the output signal from 120, signal processing unit 111 for converting the output signal from main beamformer 110 into a video signal, and display unit 112 for displaying the video signal from signal processing unit 111 It consists of.

  Hereinafter, the configuration of the sub-beamformer 119 will be described. A sub beam former 120 that performs phasing addition of reception signals from the transducers 105 and 106 that constitute the sub array 102 also has the same configuration as the sub beam former 119.

  The sub beam former 119 amplifies reception signals from the transducers 103 and 104 constituting the sub array 101 and outputs positive phase (+) and negative phase (−) signals, and an amplification unit. Cross-point switches (CPS) 125 and 126 for selecting positive-phase or reverse-phase output signals from 121 and 122, respectively, and a variable amplitude unit 127 for amplifying the output signals from the cross-point switch 125 by changing the amplification factor, 128, variable amplitude units 129 and 130 that amplify the output signal from the crosspoint switch 126 by changing the amplification factor, an adder 131 that adds the output signals from the variable amplitude units 127 and 129, and a variable amplitude unit 128. And an adder 132 for adding the output signals from 130 and the phase of the output signal from the adder 131 is changed by +45 degrees. And a phase shifter (PS) 134 for changing the phase of the output signal from the adder 132 by −45 degrees, and an adder 109 for adding the output signals of the phase shifters 133 and 134. Has been.

With this configuration, the phase of the received signal is controlled by controlling the amplitude of the received signal by the crosspoint switch and the variable amplitude unit in the sub-beamformer, and the phase of the received signal from the transducer in the sub-array is performed. .
US Pat. No. 6,013,032 (pages 8-10, FIGS. 6, 7, 9)

  However, in the above conventional method, the sub-beamformer is composed of an amplifier, a crosspoint switch, a variable amplitude unit, an adder, a phase shifter, etc., and there is a problem that the circuit configuration is complicated and the circuit scale is increased. . In addition, as a control element, it is necessary to control a plurality of points such as switching of a cross point switch and an amplification factor in a variable amplification unit.

  The present invention solves the above-described conventional problems, and can perform phasing addition of received signals from a plurality of transducers with a simpler circuit and less control than a conventional method, and has a small amount of material. An object is to provide an ultrasonic diagnostic apparatus.

  In order to achieve the above object, the first ultrasonic diagnostic apparatus according to the present invention has a configuration in which the received signals obtained by the respective transducers of the two-dimensional array are phased and added using a variable phase shifter. Have.

  With this configuration, it is possible to achieve phasing addition of received signals with less circuit configuration and less control than in the past.

  In addition, a first ultrasonic diagnostic apparatus according to the present invention includes a phase control voltage generation circuit that generates a phase control signal for a variable phase shifter from a control signal having a number smaller than the number of phase control lines of the variable phase shifter by resistance division. It has the composition provided with.

  With this configuration, phasing addition can be performed with fewer control lines than the number of variable phase shifters, and the number of cables connecting the vibrator and the main body can be reduced.

  In order to achieve the above-mentioned object, the second ultrasonic diagnostic apparatus according to the present invention is configured so that the sub-beamformer in the reception beamformer converts the echo signal obtained by each transducer constituting the two-dimensional array into a forward / reverse direction. It has a configuration including an amplifying unit that outputs two phases, and a crosspoint switch that selects one of the output signals from the amplifying unit and supplies the selected output signal to the variable phase shifter.

  With this configuration, it is possible to perform phasing addition of received signals with high accuracy with fewer circuit configurations than in the past.

  Further, in the first and second ultrasonic diagnostic apparatuses according to the present invention, when performing phasing addition of reception signals from each transducer using a two-dimensional array, the center frequency of the transmission pulse and the body can be arranged. The phase shift amount of the variable phase shifter is changed based on a change in frequency due to frequency-dependent attenuation.

  With this configuration, by changing the phase control voltage of the variable phase shifter in accordance with the transmission interval, it is possible to perform accurate phasing addition for a reception signal from a shallow part or a reception signal from a deep part. As a result, errors due to phasing addition can be reduced, more precise phasing addition can be realized, and image quality can be improved.

  According to the present invention, there is provided an ultrasonic diagnostic apparatus that can perform phased addition of received signals from a plurality of transducers with a simpler circuit and less control than conventional methods, and has a small amount of material. It becomes possible to do.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic block diagram showing a configuration example of the ultrasonic diagnostic apparatus according to the first embodiment of the present invention.

  In FIG. 1, a two-dimensional array 100 of an ultrasonic diagnostic apparatus is divided into a plurality of subarrays, for example, subarrays 101 and 102, and a plurality of subarrays not shown. The subarray 101 is composed of vibrators 103 and 104. The signal received by the transducer 103 is supplied to the variable phase shifter 107 in the sub-beamformer 119, and the signal received by the transducer 104 is supplied to the variable phase shifter 108 in the sub-beamformer 119.

  As shown in FIG. 2, the variable phase shifters 107 and 108 include an operational amplifier 113, a variable capacitance diode 115, resistors 114, 116, 117, 118, and capacitors 140, 141. Phase control voltages Vc1 and Vc2 are supplied to both ends of the variable capacitance diode 115 from a control circuit (not shown) via resistors 117 and 118, and the capacitance value of the variable capacitance diode 115 changes by the phase control voltages Vc1 and Vc2. . In addition, although there are two control terminals, phase control by one control terminal is possible by connecting one of the control terminals to the ground. In the following embodiment, a case where one control terminal is used will be described.

  As the capacitance value of the diode 115 changes, the phase of the output signal of the operational amplifier 113 rotates without changing the amplitude. Thereby, the phase of the output signal of the variable phase shifters 107 and 108 in FIG. 1 rotates.

  The signals whose phases are matched by the variable phase shifters 117 and 118 are added by the adder 109. The signal added by the adder 109 is added to the output signal of the other sub beamformer 120 in the main beamformer 110 to form the received beam shape of the entire two-dimensional array. The sub beamformer 120 has the same configuration as the subbeamformer 119.

  The output signal of the main beamformer is converted into a video signal by the signal processing unit 111 and displayed on the display unit 112.

  As described above, according to the present embodiment, phasing addition of received signals can be realized with a smaller circuit configuration and less control than in the past.

(Second Embodiment)
FIG. 3 is a schematic diagram showing a configuration of one subarray and a variable phase shifter in the two-dimensional array in the ultrasonic diagnostic apparatus according to the second embodiment of the present invention. FIG. It is a circuit diagram which shows the structural example of the phase control voltage generation circuit which supplies a phase control voltage to a phase shifter.

  In FIG. 3, the sub-array includes transducers 211, 212, 213, 214, transducers 221, 222, 223, 224, transducers 231, 232, 233, 234, transducers 241, 242, 243, 244 It is composed of Further, these vibrators include variable phase shifters 311, 312, 313, 314, variable phase shifters 321, 322, 323, 324, variable phase shifters 331, 332, 333, 334, variable phase shifters. Phase shifters 341, 342, 343, and 344 are connected to each other, so that the phase of the received signal can be changed.

  Since the sub-array output signals after the phasing addition are the same in configuration and function as those of the first embodiment, description thereof is omitted.

  The variable phase shifters 311 to 314, 321 to 324, 331 to 334, and 341 to 344 are provided with phase control voltage input terminals C11 to C14, C21 to 24, C31 to 34, and C41 to 44, respectively. These terminals are connected to each tap of the phase control voltage generation circuit 135 shown in FIG. In FIG. 4, the phase control voltage generation circuit 135 includes resistors R11 to R13, R21 to R23, R31 to R33, R41 to R43, R101 to R104, R111 to R114, R121 to R124, and the control voltage is the terminal A1. , A2, A3, and A4, phase control voltages generated by resistance division are used for phase control of each variable phase shifter.

  As described above, according to the present embodiment, for example, as in this example, the number of phase control signals of the variable phase shifter is 16, whereas the control that generates the phase control signal is performed. The number of signals can be significantly reduced to four, and the number of cables (not shown) connecting the vibrator and the main body can be reduced.

(Third embodiment)
FIG. 5 is a schematic block diagram showing a configuration example of an ultrasonic diagnostic apparatus according to the third embodiment of the present invention. In the present embodiment, the reception signals obtained by the vibrators 103 and 104 are input to the amplification units 121 and 122, respectively, and signals having two phases of normal phase (0 degree) and reverse phase (180 degrees) are output. Is done. The switches 123 and 124 select one of the two output signals of the amplifiers 121 and 122, respectively, and send it to the variable phase shifters 107 and 108. In this example, when the phase variable range of the variable phase shifter is narrow and it is difficult to rotate the phase by 360 degrees, either one of the output signals of 0 degrees and 180 degrees from the amplifier is selected by the switches 123 and 124. Thus, if the phase rotation range of the variable phase shifters 107 and 108 is 180 degrees, the present invention can be realized.

  Also in the present embodiment, the switches 123 and 124 can be configured with a switch having a smaller amount than the conventional cross point switch, and there is an advantage that the variable amplitude unit of the conventional example is not necessary.

  As described above, according to the present embodiment, it is possible to perform phasing addition of received signals with high accuracy with fewer circuit configurations than in the past.

(Fourth embodiment)
FIG. 6A is a block diagram illustrating a configuration example of a phase control voltage generation circuit that generates a phase control voltage for a variable phase shifter in the ultrasonic diagnostic apparatus according to the fourth embodiment of the present invention. Other configurations not shown in FIG. 6A are the same as the configurations of the first embodiment shown in FIG. 1 or the third embodiment shown in FIG.

  It is well known that when ultrasonic waves propagate in the body, frequency-dependent attenuation occurs, and the center frequency decreases as the received signal from a deeper part. For this reason, if the phasing addition is always performed with the same phase in the sub-beamformer, for example, if the phase of the reception signal from the shallow part is set to match, there is a problem that the phase of the reception signal from the deep part shifts. To do. The present embodiment provides a phase control voltage generation circuit that solves this problem.

  In FIG. 6A, the phase control voltage generation circuit includes a controller 401, a memory 402, and a D / A converter 403. The controller 401 outputs phase data linked to the transmission timing shown in FIG. 6B to the memory 402, and the memory 402 converts the phase data into voltage data and outputs the voltage data. Output data from the memory 402 is converted into a phase control voltage (FIG. 6B) of an analog signal by a D / A converter, and the phase of the variable phase shifter is controlled by this phase control voltage.

  As described above, according to the present embodiment, by changing the phase control voltage of the variable phase shifter in accordance with the transmission interval, it is possible to obtain a high accuracy with respect to a received signal from a shallow part or a deep part. Phased addition can be performed. As a result, errors due to phasing addition can be reduced, more precise phasing addition can be realized, and image quality can be improved.

  As described above, the ultrasonic diagnostic apparatus according to the present invention performs beam forming in a two-dimensional array with a small circuit scale by performing phasing addition of received signals in the sub-beamformer using a variable phase shifter. It is extremely useful for realizing an inexpensive real-time three-dimensional display.

1 is a schematic block diagram showing a configuration example of an ultrasonic diagnostic apparatus according to a first embodiment of the present invention. 1 is a circuit diagram showing an example of the internal configuration of the variable phase shifter of FIG. The schematic diagram which shows the structure of one subarray and the variable phase shifter in the two-dimensional array in the ultrasonic diagnosing device which concerns on the 2nd Embodiment of this invention. The circuit diagram which shows the structural example of the phase control voltage generation circuit which supplies a phase control voltage to the variable phase shifter of FIG. Schematic block diagram showing one configuration example of an ultrasonic diagnostic apparatus according to the third embodiment of the present invention The block diagram which shows the structural example of the phase control voltage generation circuit which produces | generates the phase control voltage with respect to the variable phase shifter in the ultrasonic diagnosing device which concerns on the 4th Embodiment of this invention. Timing chart showing change of phase control voltage with respect to transmission timing in ultrasonic diagnostic apparatus according to fourth embodiment of the present invention Schematic block diagram showing a configuration example of a conventional ultrasonic diagnostic apparatus

Explanation of symbols

100 Two-dimensional array 101, 102 Subarray 103-106 Vibrator 107, 108 Variable phase shifter 109 Adder 110 Main beamformer 111 Signal processing unit 112 Display unit 113 Operational amplifier 114, 116, 117, 118 Resistance 115 Capacitance variable diode 119, 120 Sub-beamformer 121, 122 Amplifier 123, 124 Switch 125, 126 Crosspoint switch (CPS)
127-130 Variable control unit 131, 132 Adder 133, 134 Phase shifter 135 Control voltage generation circuit 140, 141 Capacitor 211-214, 221-224, 231-234, 241-244 Vibrator 311-314, 321-324, 331-334, 341-344 Variable phase shifter 401 Controller 402 Memory 403 D / A converter R11-R13, R21-R23, R31-R33, R41-R43, R101-R104, R111-R114, R121-R124 Resistance

Claims (4)

A two-dimensional array in which a plurality of transducers are arranged two-dimensionally;
The plurality of transducers are divided into a plurality of groups, and phasing addition of reception signals from the plurality of transducers in each group is performed to generate reception signals for each group, and further, reception signals from the plurality of groups A receiving beam former that performs deflection and focusing of the received beam by phasing and summing,
The ultrasonic diagnostic apparatus, wherein the reception beamformer includes a variable phase shifter that performs phased addition of reception signals in a group by changing a phase of reception signals.   The ultrasonic diagnostic apparatus according to claim 1, further comprising: a phase control voltage generating circuit that generates a phase control signal for the variable phase shifter from a control signal having a number smaller than the number of phase control lines of the variable phase shifter by resistance division. A two-dimensional array in which a plurality of transducers are arranged two-dimensionally;
The plurality of transducers are divided into a plurality of groups, and phasing addition of reception signals from the plurality of transducers in each group is performed to generate reception signals for each group, and further, reception signals from the plurality of groups A receiving beam former that performs deflection and focusing of the received beam by phasing and summing,
The reception beamformer performs phasing addition of reception signals for each group,
An amplification unit that receives a reception signal from the vibrator and outputs a normal phase signal and a negative phase signal;
A switch for selecting any one of the output signals from the amplification unit;
An ultrasonic diagnostic apparatus comprising: a variable phase shifter that changes a phase of a signal selected by the switch. The ultrasonic diagnostic apparatus according to claim 1, wherein the variable phase shifter changes a phase shift amount based on a center frequency of a received signal.

Images