JP2010213787A - Ultrasonic diagnosis device - Google Patents

Abstract

An ultrasonic diagnostic apparatus including a distributed power supply system reduces image noise while suppressing heat generation.
In an ultrasonic diagnostic apparatus, an AC / DC power supply 30, a clock control circuit 10, and a dropper that converts a DC voltage output from the AC / DC power supply 30 into a predetermined voltage and supplies the voltage to the clock control circuit 10. The DC / DC converters 41 to 43 and the clock signal output from the clock control circuit 10 perform a switching operation, and the DC voltage output from the AC / DC power supply 30 is converted into a predetermined voltage for clock control. Switching DC / DC converters 51 to 53 to be supplied to a predetermined circuit other than the circuit 10, setting means for setting a pulse repetition frequency, and a clock signal output to the switching DC / DC converters 51 to 53 are the pulse repetitions. Control means 20 for controlling the clock control circuit 10 is provided so as to be an integral multiple of the frequency.
[Selection] Figure 2

Description

  The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to a power supply system for an ultrasonic diagnostic apparatus.

  FIG. 5 shows a configuration of a general power supply system in a conventional ultrasonic diagnostic apparatus. In the conventional power supply system, the AC / DC power supply 80 converts commercial alternating current into direct current voltage and generates a plurality of types of voltages + Vcc1 and + Vcc2 necessary for driving each circuit, and this is used as a transmission line 81 comprising a cable or the like. To each circuit (devices A to D in the figure) in the ultrasonic diagnostic apparatus. A configuration in which all voltages required in the apparatus are generated by a single power supply and supplied to each unit is called a centralized power supply system.

  As the AC / DC power supply 80 in such a power supply system, a switching power supply is generally used from the viewpoint of reduction in size and weight of the apparatus and energy efficiency. The switching power supply temporarily smoothes the input commercial alternating current, then turns it on / off at a predetermined duty ratio by high-frequency switching, and then smoothes again to output a predetermined direct current voltage.

  However, since such a switching power supply has a problem of noise generation due to high-frequency switching, various measures are taken such as shielding the power supply or providing a filter on the output side of the power supply. For example, Patent Document 1 describes that in ultrasonic diagnosis using a pulse Doppler method or the like, the occurrence of noise on an image can be reduced by setting the switching frequency in the switching power supply to an integral multiple of the pulse repetition frequency of the ultrasonic wave. Yes.

  By the way, in recent years, with the improvement in performance of digital devices such as CPUs and FPGAs (Field Programmable Gate Arrays), it is necessary to change the power supply system from the conventional centralized power supply system. This is because the drive voltage of each device is reduced and diversified, and the power consumption changes greatly during the operation of each device, so the voltage changes due to small impedances such as cables, connectors, and conductor patterns on the board (Fig. 6) to influence the operation of each device.

  For example, assuming that the impedance of the cable between the AC / DC power supply and the predetermined device, the contact resistance of the connector, etc. is 100 mΩ in total, and the current consumption of the device changes by 2 A, the voltage drop at that time is 2A × 0.1Ω = 0.2V. Therefore, when the voltage supplied to the device is 1.2 V, a voltage drop of about 16% occurs.

  Therefore, in recent years, as shown in FIG. 7, DC / DC converters 91 to 94 are provided in the vicinity of each of the devices A to D, and a DC voltage + Vcc of a predetermined magnitude supplied from the AC / DC power supply 80 is changed to DC. A method of converting the voltages to + Vcc1 to + Vcc4 necessary for driving each of the devices A to D by the DC converters 91 to 94 has become mainstream. In this way, a configuration for generating a voltage necessary for each device in the vicinity of each device is called a distributed power supply system.

Japanese Patent Laid-Open No. 5-130992

  There are two types of DC / DC converters: a dropper type that performs voltage conversion using a voltage drop caused by a transistor or the like, and a switching type that performs voltage conversion by switching. When the voltage of 1 is supplied by a dropper type DC / DC converter, the heat generated by the dropper becomes a problem.

  Therefore, as a DC / DC converter in the distributed power supply system, a switching type DC / DC converter is generally employed. However, in this case, since switching is performed near each device, it is more susceptible to noise than a conventional centralized power supply system. For example, in an ultrasonic diagnostic apparatus equipped with a digital beam former, a received echo signal is amplified by an amplifier and converted into a digital signal by an A / D converter, and then digital signal processing is performed. For this reason, digital circuits such as amplifiers, A / D converters, and FPGAs are often mounted on the same board, and DC / DC converters corresponding to the respective circuits are also mounted on the same board. At this time, if a DC / DC converter of the switching type is used, the switching noise tends to enter an amplifier on the same substrate and image noise is likely to be generated. Such deterioration in image quality due to switching noise is particularly noticeable in Doppler imaging.

  The present invention has been made in view of the above points, and an object of the present invention is to provide an ultrasonic diagnostic apparatus having a distributed power supply system that can prevent generation of image noise while suppressing heat generation. The object is to provide an ultrasonic diagnostic apparatus.

An ultrasonic diagnostic apparatus according to the present invention, which is made to solve the above problems, is an ultrasonic diagnostic apparatus that acquires and images information inside a subject by transmitting and receiving ultrasonic waves to the subject. ,
a) battery or AC / DC power supply;
b) a clock control circuit for generating a predetermined clock signal;
c) a dropper-type DC / DC converter that converts a DC voltage output from the battery or AC / DC power source into a predetermined DC voltage and supplies the DC voltage to the clock control circuit;
d) By performing a switching operation in synchronization with the clock signal output from the clock control circuit, the DC voltage output from the battery or the AC / DC power source is converted into a predetermined DC voltage and other than the clock control circuit. A switching type DC / DC converter for supplying a predetermined circuit;
e) PRF setting means for setting a pulse repetition frequency in ultrasonic transmission and reception;
f) control means for controlling the clock control circuit so that the clock signal output to the switching DC / DC converter is an integer multiple of the pulse repetition frequency set by the PRF setting means;
It is characterized by having.

  The PRF setting means may be provided with an input device such as a keyboard and a trackball, and may allow the operator to directly input a pulse repetition frequency, or an imaging condition designated by the operator using the input device. An appropriate pulse repetition frequency may be determined on the apparatus side from (imaging mode, depth of field, etc.) and set as a pulse repetition frequency used in subsequent imaging. In addition, the apparatus side automatically reads out the set value of the pulse repetition frequency (for example, the pulse repetition frequency used in the previous imaging) stored in advance in a predetermined storage device when the ultrasonic diagnostic apparatus is started, and the subsequent imaging. It may be set as a pulse repetition frequency used in the above.

  In the ultrasonic diagnostic apparatus of the present invention configured as described above, when power is turned on and voltage supply from the battery or AC / DC power supply is started, a dropper type DC / DC converter is first activated. At this time, since the clock signal is not generated, the switching type DC / DC converter does not start. Thereafter, when a predetermined DC voltage is supplied from the dropper type DC / DC converter and the clock control circuit is activated, a clock signal generated by the clock control circuit is input to the switching type DC / DC converter. As a result, a switching operation in synchronization with the clock signal is started in the switching type DC / DC converter, and a predetermined DC voltage is supplied to each circuit to start the entire ultrasonic diagnostic apparatus. Here, the clock signal supplied from the clock control circuit to the switching DC / DC converter is controlled to be an integral multiple of the pulse repetition frequency set by the PRF setting means. Therefore, the switching type DC / DC converter performs a switching operation at a frequency that is an integral multiple of the PRF, thereby suppressing the occurrence of image noise.

  Note that all DC / DC converters for supplying voltage to circuits other than the clock control circuit do not necessarily need to be switching types, and a dropper type DC / DC converter is provided for circuits with low power consumption. You may do it.

  In the ultrasonic diagnostic apparatus according to the present invention, the AC / DC power supply is a switching power supply capable of switching operation by self-excited oscillation and separately-excited oscillation, and immediately after the power is turned on, self-excited oscillation is performed. After performing a switching operation and then starting generation of a clock signal by the clock control circuit, it is desirable to perform a switching operation by separately excited oscillation synchronized with the clock signal. With such a configuration, image noise due to switching can be more effectively prevented.

  As described above, according to the ultrasonic diagnostic apparatus according to the present invention, it is possible to prevent the image quality from being deteriorated due to switching noise in the ultrasonic diagnostic apparatus including the distributed power supply system. Further, since the number of dropper type DC / DC converters used is small, heat generation can be minimized.

1 is an external view showing the overall configuration of an ultrasonic diagnostic apparatus according to an embodiment of the present invention. The block diagram which shows the power supply system in the ultrasonic diagnosing device which concerns on the Example. The block diagram which shows another example of the power supply system in the ultrasonic diagnosing device which concerns on the Example. The block diagram which shows another example of the power supply system in the ultrasonic diagnosing device which concerns on the Example. The block diagram which shows the conventional centralized power supply system. The figure explaining the fluctuation | variation of the voltage by the line impedance of a transmission line. The block diagram which shows the conventional distributed power supply system.

  Hereinafter, an ultrasonic diagnostic apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an external view showing the overall configuration of the ultrasonic diagnostic apparatus according to the present embodiment.

  The ultrasonic diagnostic apparatus according to the present embodiment is detachably attached to the main body 100 via a main body 100 movable by a caster 110, a display 200 and an operation console 300 provided on the upper portion of the main body 100, and a connector (not shown). And an ultrasonic probe 400 connected to the.

  The main body 100 includes a power supply device 120 and a control / processing unit 130. The power supply device 120 converts the commercial alternating current acquired through the outlet plug 121 into a predetermined direct current voltage and supplies the converted direct current voltage to the respective units. The control / processing unit 130 controls the operations of the above-described units and performs a series of processes for generating an ultrasonic image from an echo signal acquired by transmission / reception of ultrasonic waves and displaying the ultrasonic image on the display 200. For example, a transmission beam former that applies a transmission pulse to the ultrasonic probe 400, a reception beam former that converts an echo signal received by the ultrasonic probe 400 into a digital signal and performs phasing addition, and an output from the reception beam former Functionally, a signal processing unit that performs processing such as detection, logarithmic compression, and filtering on the signal, and a digital scan converter that generates an ultrasound image by performing scan conversion processing and interpolation processing on the output signal from the signal processing unit Is included. The functions of the control / processing unit 130 are realized by various electronic circuits built in the main body 100.

  FIG. 2 is a block diagram illustrating a schematic configuration of the power supply system of the ultrasonic diagnostic apparatus according to the present embodiment, in which the power supply apparatus 120 described above and a part of the control / processing unit 130 are illustrated. The ultrasonic diagnostic apparatus according to the present embodiment employs a distributed power supply system including one AC / DC power supply 30 and a plurality of DC / DC converters. Here, for simplification, only two devices on the substrate 140 (the clock control circuit 10 and the main control circuit 20) and the DC / DC converters 41 to 43 and 51 to 53 corresponding to them are illustrated. Actually, a DC / DC converter is provided in the vicinity of each functional block (IC chip, analog circuit, display, etc.) constituting the ultrasonic diagnostic apparatus.

  The AC / DC power supply 30 is a switching-type power supply that converts commercial alternating current supplied through the outlet plug 121 into direct current and drops the direct-current voltage to a predetermined voltage by high-frequency switching. The DC voltage output from the AC / DC power supply 30 is supplied to a substrate 140 on which various ICs are mounted through a transmission line 150 including a cable, a connector, and a pattern on the substrate. Note that this AC / DC power supply 30 has an external signal input terminal, and switching between self-excited oscillation and switching by separately excited oscillation in accordance with the clock signal from the clock control circuit 10 can be executed. Is possible.

  The DC / DC converters 41 to 43 and 51 to 53 are mounted on the same substrate 140 as the devices 10 and 20 to be supplied with power, and each device requires a predetermined DC voltage supplied from the AC / DC power supply 30. And then supplied to the device. In the example of FIG. 2, the devices constituting the main control circuit 20 and the clock control circuit 10 request a plurality of drive voltages + Vcc1, + Vcc2, and + Vcc3, respectively. Dropper type DC / DC converters 41 to 43 are provided in the vicinity of the clock control circuit 10, and a separately excited oscillation type (external signal synchronization type) switching type having an external signal input terminal in the vicinity of the main control circuit 20. DC / DC converters 51 to 53 are provided. As a DC / DC converter for supplying a voltage to devices other than the clock control circuit 10, it is desirable to use a switching type in terms of power utilization efficiency, but for a circuit with low power consumption, A dropper type DC / DC converter may be provided.

  The main control circuit 20 performs operation control and various types of information processing of each device constituting the ultrasonic diagnostic apparatus, and includes, for example, a CPU. The clock control circuit 10 generates one or a plurality of types of clock signals having a predetermined frequency from a basic clock generated by a crystal resonator (not shown) and supplies the clock signals to each device constituting the control / processing unit 130 For example, it is composed of FPGA.

  Hereinafter, a startup procedure (startup sequence) of the ultrasonic diagnostic apparatus according to the present embodiment will be described.

  First, when the operator turns on the power by pressing a switch or the like provided outside the console 300 or the main body 100, the AC / DC power supply 30 starts a switching operation by self-excited oscillation to generate a predetermined DC voltage + Output Vcc.

  The DC voltage + Vcc is supplied to the dropper type DC / DC converters 41 to 43 and the switching type DC / DC converters 51 to 53. At this time, the clock signal from the clock control circuit 10 is applied. Therefore, the switching type DC / DC converters 51 to 53 do not operate. Accordingly, only the dropper type DC / DC converters 41 to 43 start to operate, and the direct current voltage + Vcc from the AC / DC power supply 30 is converted into the direct current voltages + Vcc1, + Vcc2, and + Vcc3 to generate the clock control circuit 10. To supply.

  As a result, the clock control circuit 10 is activated to generate a clock signal having a predetermined frequency, and the clock signal is supplied to the switching DC / DC converters 51 to 53 and the AC / DC power supply 30. As a result, the AC / DC power supply 30 switches from self-excited oscillation to separately-excited oscillation based on the clock signal and continues to supply the DC voltage + Vcc. The switching type DC / DC converters 51 to 53 receive the clock signal and start a switching operation in synchronization with the clock signal. The switching type DC / DC converters 51 to 53 convert the DC voltage + Vcc from the AC / DC power supply 30 to the DC voltage + Vcc1. , + Vcc2 and + Vcc3 are supplied to the main control circuit 20.

  At this time, the clock signal from the clock control circuit 10 is also supplied to a switching DC / DC converter in the vicinity of another device (not shown). Thereby, a predetermined DC voltage is supplied to each part of the main body 100, the console 300, the display 200, and the ultrasonic probe 400, and the entire ultrasonic diagnostic apparatus is activated.

  Thereafter, when the operator operates the console 300 to determine the imaging condition, the main control circuit 20 determines that the clock signal supplied to the DC / DC converters 51 to 53 and the AC / DC power supply 30 is a pulse defined by the imaging condition. The clock control circuit 10 is controlled so as to be an integral multiple of the repetition frequency.

  As described above, since the entire power supply system excluding the dropper type DC / DC converter performs a switching operation at a frequency that is an integral multiple of the pulse repetition frequency, generation of image noise due to power supply switching is suppressed, and Doppler is suppressed. It is possible to obtain a clear image with little noise even in imaging by the method. In this embodiment, since the dropper type DC / DC converter is used only for the clock control circuit 10 and a part of the circuit with low power consumption, heat generation can be minimized.

  The present invention can also be applied to a battery-driven ultrasonic diagnostic apparatus. A configuration example of the power supply system in such a case is shown in FIG. This configuration is substantially the same as the above embodiment except that a battery 60 is provided in place of the AC / DC power supply 30. When the power is turned on, a predetermined DC voltage + Vcc is output from the battery 60, and first the dropper type DC / DC converters 41 to 43 start operation. Thereby, when the output of the clock signal from the clock control circuit 10 is started, the switching type DC / DC converters 51 to 53 start a switching operation synchronized with the clock signal. The frequency of the clock signal supplied to the switching type DC / DC converters 51 to 53 is controlled so as to be an integral multiple of the pulse repetition frequency as in the above embodiment.

  In the above-described embodiment, each voltage + Vcc1, + Vcc2, + Vcc3 required by the clock control circuit 10 is generated by the dropper type DC / DC converters 41 to 43. For example, as shown in FIG. 4, the self-excited oscillation type switching DC / DC converters 71 a to 73 a and the separately excited oscillation type switching DC / DC converter 71 b to supply the necessary voltage to the clock control circuit 10. 73b may be provided. In this case, immediately after the power is turned on and the power supply from the AC / DC power supply 30 or the battery is started, the voltage + Vcc1 is applied to the clock control circuit 10 by the self-excited oscillation type switching DC / DC converters 71a to 73a. , + Vcc2 and + Vcc3 are supplied. Thereafter, after the output of the clock signal from the clock control circuit 10 is started, the self-excited oscillation type switching DC / DC converters 71a to 73a stop operating, and instead of this, the separately excited oscillation type switching type The DC / DC converters 71b to 73b start a switching operation synchronized with the clock signal, and supply DC voltages + Vcc1, + Vcc2, and + Vcc3 to the clock control circuit 10. Other operations are the same as in the above embodiment.

DESCRIPTION OF SYMBOLS 10 ... Clock control circuit 20 ... Main control circuit 30 ... AC / DC power supply 41-43 ... Dropper type DC / DC converter 51-53 ... Switching type DC / DC converter 60 ... Battery 140 ... Board | substrate 150 ... Transmission path

Claims (3)

An ultrasound diagnostic apparatus that acquires and images information inside a subject by transmitting and receiving ultrasound to the subject,
a) battery or AC / DC power supply;
b) a clock control circuit for generating a predetermined clock signal;
c) a dropper-type DC / DC converter that converts a DC voltage output from the battery or AC / DC power source into a predetermined DC voltage and supplies the DC voltage to the clock control circuit;
d) By performing a switching operation in synchronization with the clock signal output from the clock control circuit, the DC voltage output from the battery or the AC / DC power source is converted into a predetermined DC voltage and other than the clock control circuit. A switching type DC / DC converter for supplying a predetermined circuit;
e) PRF setting means for setting a pulse repetition frequency in ultrasonic transmission and reception;
f) control means for controlling the clock control circuit so that the clock signal output to the switching DC / DC converter is an integer multiple of the pulse repetition frequency set by the PRF setting means;
An ultrasonic diagnostic apparatus comprising: An ultrasound diagnostic apparatus that acquires and images information inside a subject by transmitting and receiving ultrasound to the subject,
a) battery or AC / DC power supply;
b) a clock control circuit for generating a predetermined clock signal;
c) By performing a switching operation at a predetermined frequency, the DC voltage output from the battery or the AC / DC power source is converted into a predetermined DC voltage and supplied to the clock control circuit and is supplied to the clock control circuit. / DC converter,
d) By performing a switching operation in synchronization with the clock signal output from the clock control circuit, the DC voltage output from the battery or the AC / DC power source is converted into a predetermined DC voltage to be supplied to the clock control circuit. A separately-excited oscillation type switching DC / DC converter to be supplied;
e) By performing a switching operation in synchronization with the clock signal output from the clock control circuit, the DC voltage output from the battery or the AC / DC power source is converted into a predetermined DC voltage, and other than the clock control circuit. A switching type DC / DC converter for supplying a predetermined circuit;
f) PRF setting means for setting a pulse repetition frequency in ultrasonic transmission / reception;
g) control means for controlling the clock control circuit so that the clock signal output to the switching DC / DC converter is an integral multiple of the pulse repetition frequency set by the PRF setting means;
Have
Immediately after the voltage supply from the battery or AC / DC power supply is started, a predetermined DC voltage is supplied to the clock control circuit by the self-excited oscillation type switching DC / DC converter, and then the clock control circuit After the generation of the clock signal is started, the ultrasonic diagnostic apparatus is switched to the separately-excited oscillation type DC / DC converter and supplies a predetermined DC voltage to the clock control circuit.   The AC / DC power supply is a switching power supply capable of switching operation by self-excited oscillation and self-excited oscillation. Immediately after the power is turned on, the AC / DC power supply performs switching operation by self-excited oscillation, and then the clock control circuit performs clock operation. 3. The ultrasonic diagnostic apparatus according to claim 1, wherein after the generation of the signal is started, a switching operation by separately excited oscillation synchronized with the clock signal is performed.

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