JP4877939B2 - Ultrasonic diagnostic equipment - Google Patents

Description

  The present invention relates to an ultrasonic diagnostic apparatus. Specifically, the present invention relates to an ultrasonic diagnostic apparatus in which an ultrasonic probe including at least one ultrasonic transducer and a transceiver including a transmission circuit and a reception circuit are connected by a cable.

In general, an ultrasonic diagnostic apparatus is configured by connecting an ultrasonic probe (probe) and a transceiver with a cable. The ultrasonic probe has a plurality of ultrasonic transducers. The transceiver includes a transmission circuit and a reception circuit. The transceiver is provided with a transmission / reception separation circuit.
The transmission circuit generates a transmission signal that is a high-voltage AC signal. The transmission signal is transmitted to the ultrasonic probe via a cable. The ultrasonic transducer of the ultrasonic probe generates an ultrasonic wave by being excited by a transmission signal. The ultrasonic wave reflected inside the subject is received as a reception signal by the ultrasonic transducer of the ultrasonic probe. The received signal is transmitted via a cable and sent to the receiving circuit via the transmission / reception separating circuit. The received signal is amplified by a preamplifier, and image processing and image display are performed.

  The received signal is a weak signal of about several tens to several hundred mV. Therefore, the S / N ratio of the received signal is deteriorated due to the loss due to the cable capacity and the on-resistance of the high voltage switch. Therefore, an ultrasonic diagnostic apparatus in which a preamplifier is provided inside the ultrasonic probe has been proposed (see, for example, [Patent Document 1]). This ultrasonic diagnostic apparatus reduces noise by amplifying a received signal during cable transmission by a preamplifier.

Japanese Unexamined Patent Publication No. 63-177839

However, the conventional ultrasonic diagnostic apparatus has a problem that it is necessary to provide a transmission / reception separation circuit together with a preamplifier inside the ultrasonic probe.
In order to share a cable during transmission and reception, at least two transmission / reception separation protection circuits are required on the input side and output side of the preamplifier for each ultrasonic transducer. When providing cables for transmission and reception, it is necessary to provide one transmission / reception separation protection circuit for each ultrasonic transducer inside the ultrasonic probe. This is because the transmission signal is blocked and only the reception signal is allowed to pass to prevent the high-voltage transmission signal from destroying the preamplifier or the like.

  The transmission / reception separating circuit includes a diode and a reactance element connected in antiparallel. A large number of ultrasonic transducers are arranged in the ultrasonic probe. For example, 60 to 200 ultrasonic transducers are arranged one-dimensionally, or about several hundred to several thousand ultrasonic transducers are arranged two-dimensionally. The ultrasonic diagnostic apparatus switches the transmission / reception direction of ultrasonic waves at high speed by independently controlling and driving each ultrasonic transducer. Therefore, when the preamplifier is accommodated in the ultrasonic probe, it is necessary to provide several hundred to several thousand transmission / reception separation circuits in the ultrasonic probe, which increases the circuit scale. There is. Further, the transmission / reception separation circuit causes a loss of a transmission signal at the time of transmission and a noise generation at the time of reception, which causes a problem of image quality deterioration.

  The present invention has been made in view of the above problems, and an ultrasonic diagnosis that makes it possible to accommodate a preamplifier for amplifying a received signal inside an ultrasonic probe without increasing the circuit scale. An object is to provide an apparatus.

In order to achieve the above-described object, the first invention provides an ultrasonic probe including a plurality of ultrasonic transducers for transmitting and receiving ultrasonic waves in a subject, and a transmission for supplying a transmission signal to the ultrasonic transducers. A reception unit having a plurality of preamplifiers for amplifying a reception signal from the ultrasonic transducer, an image processing unit forming an ultrasonic image based on the reception signal output from the reception unit, and the ultrasonic wave An ultrasonic diagnostic apparatus comprising: an image display unit that displays an image; a first switch that opens and closes a first power supply terminal of the preamplifier connected to a first power supply; and the preamplifier connected to a second power supply. A second switch that opens and closes the second power supply terminal, and a third switch formed by a pair of diodes connected in reverse parallel to the output terminal of the preamplifier and the ultrasonic transducer for each ultrasonic transducer. The super The ultrasonic diagnostic apparatus is characterized in that the preamplifier is protected by opening the first and second power supply terminals by the first and second switches when transmitting sound waves.

  The ultrasonic diagnostic apparatus includes a switch that opens and closes a power terminal of a preamplifier that amplifies a received signal. The switch is a high voltage switch that electrically disconnects the power terminal of the preamplifier from the power source. At the time of transmitting ultrasonic waves, the switch is turned “off”, and the preamplifier is in an undefined state (floating). Thereby, the preamplifier is protected from the transmission signal. When receiving an ultrasonic wave, the switch is turned “ON” and operates as a normal preamplifier to amplify the received signal.

  As a result, when the preamplifier is accommodated in the ultrasonic probe, the transmission / reception separation circuit that has been conventionally required is not required. Therefore, it is possible to suppress an increase in circuit scale, deterioration of a transmission signal, and generation of noise at the time of reception, and to prevent image quality deterioration of an ultrasonic image.

According to a second aspect of the present invention, there is provided an ultrasonic probe including a plurality of ultrasonic transducers that transmit and receive ultrasonic waves in a subject, a transmission unit that supplies a transmission signal to the ultrasonic transducers, and the ultrasonic waves A receiving unit having a plurality of preamplifiers for amplifying a received signal from the transducer, an image processing unit for forming an ultrasonic image based on the received signal output from the receiving unit, and an image display for displaying the ultrasonic image A diode that protects the preamplifier by connecting the preamplifier to a power source when receiving the ultrasonic wave, and disconnecting the preamplifier from the power source when transmitting the ultrasonic wave. An ultrasonic diagnostic apparatus comprising: a switch formed by a pair of diodes connected in reverse parallel to the output terminal of the preamplifier and the ultrasonic transducer for each ultrasonic transducer. It is.

The preamplifier, the switch, and the like are desirably housed inside the ultrasonic probe.
Thereby, the loss accompanying the capacity of the cable can be prevented and the S / N ratio of the received signal can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, the ultrasonic diagnostic apparatus which makes it possible to accommodate the preamplifier for receiving signal amplification in the inside of an ultrasonic probe, without increasing a circuit scale can be provided.

  Hereinafter, preferred embodiments of an ultrasonic diagnostic apparatus according to the present invention will be described in detail with reference to the accompanying drawings. In the following description and the accompanying drawings, the same reference numerals are given to components having substantially the same functional configuration, and redundant description will be omitted.

(1. First embodiment)
First, the ultrasonic diagnostic apparatus 1 according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2.

(1-1. Configuration of the ultrasonic diagnostic apparatus 1)
FIG. 1 is a configuration diagram of the ultrasonic diagnostic apparatus 1.
The ultrasonic diagnostic apparatus 1 is configured by connecting an ultrasonic probe 2 and a transceiver 10 with a cable 11. The ultrasonic probe 2 has a plurality of ultrasonic transducers 9. The transceiver 10 includes a transmission circuit 3, a reception circuit 4, a transmission / reception separation circuit 5, a control unit 6, an image processing unit 7, and an image display unit 8.

The transmission circuit 3 has a plurality of transmitters corresponding to the ultrasonic transducers 9. Each transmitter has a transmission amplifier that amplifies the transmission signal. The receiving circuit 4 has a plurality of receivers corresponding to the ultrasonic transducers 9. Each receiver has a preamplifier for amplifying the received signal. A transmission / reception separation circuit 5 is provided at a connection point between the transmission circuit 3 and the reception circuit 4. The control unit 6 is a device that sends control signals to the transmission circuit 3 and the reception circuit 4.
In FIG. 1, the receiving circuit 4 is provided in the transmitter / receiver 10, but the preamplifier 21 for receiving signal amplification is provided in the ultrasonic probe 2 as shown in FIG.

The ultrasonic diagnostic apparatus 1 sends a transmission signal from the transmission circuit 3 to the ultrasonic probe 2 via the transmission / reception separation circuit 5 and irradiates the ultrasonic signal from the ultrasonic probe 2 into the subject. The ultrasonic diagnostic apparatus 1 receives an ultrasonic signal reflected in the subject by the ultrasonic probe 2 and sends it to the receiving circuit 4 via the transmission / reception separating circuit 5. The ultrasonic diagnostic apparatus 1 performs image processing on the ultrasonic signal by the image processing unit 7 and displays an image by the image display unit 8.
The received signal is amplified by a preamplifier 21 provided inside the ultrasonic probe 2 and then transmitted to the transceiver 10 via the cable 11.

(1-2. Internal circuit of ultrasonic probe 2)
FIG. 2 is an internal circuit diagram of the ultrasonic probe 2.
A preamplifier 21 and a TR switch 22 are connected in parallel between the ultrasonic transducer 9 and the cable 11. The preamplifier 21 is an amplification circuit for received signals. The TR switch 22 is a circuit that blocks a weak reception signal and allows only a high-voltage transmission signal to pass. The TR switch 22 is configured by connecting a diode D1 and a diode D2 in antiparallel.

  The power supply terminal of the preamplifier 21 is connected to the power supply Vdd and the power supply Vss via the switch 23 and the switch 24. The switches 23 and 24 are high voltage switches that electrically disconnect the power terminal of the preamplifier 21 from the power supply Vdd and the power supply Vss. As for the switch 23 and the switch 24, for example, switching elements such as PMOS (P channel MOS transistor) and NMOS (N channel MOS transistor) can be used in combination.

(1-3. Operation of Internal Circuit of Ultrasonic Probe 2)
FIG. 3 is a diagram illustrating the control signal 31 of the switch 23 and the switch 24.
(1-3-1. Operation during ultrasonic transmission)
In the ultrasonic transmission period 32, an “OFF” signal is input to the switch 23 and the switch 24, and the switch 23 and the switch 24 are turned “off”. The preamplifier 21 is in an undefined state (floating) with respect to the power supply potential. That is, there is no potential difference across the preamplifier 21.
A transmission signal sent from the transceiver 10 via the cable 11 is input to the ultrasonic transducer 9 via the TR switch 22 to excite the ultrasonic transducer 9. A high voltage of a transmission signal is applied to the preamplifier 21. However, since the preamplifier 21 is in a potential indefinite state, the potential of the preamplifier 21 itself fluctuates with the voltage of the transmission signal. Therefore, no potential difference is generated in the preamplifier 21 itself, so that the preamplifier 21 can be protected.

(1-3-2. Operation when receiving ultrasonic waves)
In the ultrasonic wave reception period 33, an “ON” signal is input to the switches 23 and 24, and the switches 23 and 24 are turned “on”.
A reception signal from the ultrasonic transducer 9 is blocked by the TR switch 22 and input to the preamplifier 21. The received signal is amplified with a predetermined gain by the preamplifier 21 and transmitted to the transceiver 10 via the cable 11.
The TR switch 22 not only blocks a weak received signal but also serves to prevent the transmission signal noise transmitted through the cable 11 from being input to the preamplifier 21.

(1-4. Effects)
As described above, in the first embodiment, a high voltage switch that electrically disconnects the power supply terminal of the preamplifier from the power supply is provided. During transmission of the ultrasonic wave, the high withstand voltage switch is turned “off”, and the preamplifier is in a potential indefinite state. Thereby, the preamplifier is protected from the transmission signal. When receiving the ultrasonic wave, the high voltage switch is turned “ON” and operates as a normal preamplifier to amplify the received signal.
Thus, since the preamplifier can be built in without providing a transmission / reception separation circuit in the internal circuit of the ultrasonic probe 2, an increase in circuit scale can be suppressed. In addition, since it is not necessary to provide a transmission / reception separation circuit, it is possible to suppress deterioration of the transmission signal and generation of noise at the time of reception, and prevent image quality deterioration of the ultrasonic image. Thereby, the ultrasonic probe excellent in economical and performance can be provided.

(2. Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG.

(2-1. Internal circuit of ultrasonic probe 2a)
FIG. 4 is an internal circuit diagram of the ultrasonic probe 2a.
The ultrasonic probe 2 of the first embodiment has one ultrasonic transducer 9, but the ultrasonic probe 2 a of the second embodiment has a plurality of ultrasonic transducers 9. .
Each of the plurality of ultrasonic transducers 9 is connected to the transceiver 10 by an individual connection line. The cable 11 bundles the connection lines.
The preamplifier 21 is provided for each ultrasonic transducer 9. The switch 23 a and the switch 24 a are individually provided for each preamplifier 21.
(2-2. Operation of Internal Circuit of Ultrasonic Probe 2a)
During transmission of ultrasonic waves, the switch 23a and the switch 24a are turned off, and the preamplifier 21 is in a potential indefinite state. Thereby, the preamplifier 21 is protected from the transmission signal. When receiving the ultrasonic wave, the switch 23a and the switch 24a are turned on, and operate as a normal preamplifier to amplify the received signal.

(2-3. Effect)
As described above, also in the second embodiment, the same effect as in the first embodiment can be obtained. In addition, even when the ultrasonic probe has a plurality of ultrasonic transducers, the preamplifier can be accommodated without providing a transmission / reception separating circuit inside the ultrasonic probe.

(3. Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG.

(3-1. Internal circuit of ultrasonic probe 2b)
FIG. 5 is an internal circuit diagram of the ultrasonic probe 2b.
The ultrasonic probe 2a of the second embodiment has a switch 23a and a switch 24a for each of the plurality of ultrasonic transducers 9, but the ultrasonic probe 2b of the third embodiment is a common switch. 23b and the common switch 24b are shared by the plurality of preamplifiers 21. A diode 25 and a diode 26 are connected between the power supply terminal of each preamplifier 21 and the common switch 23b and the common switch 24b. The diode 25 and the diode 26 are high breakdown voltage diodes for preventing backflow.

(2-2. Operation of Internal Circuit of Ultrasonic Probe 2a)
During the transmission of ultrasonic waves, the common switch 23b and the common switch 24b are turned “off” during the transmission of ultrasonic waves to protect the preamplifier 21. During reception of ultrasonic waves, the common switch 23b and the common switch 24b are turned on, and operate as a normal preamplifier to amplify the received signal.

  The ultrasonic diagnostic apparatus 1 uses transmission signals having different phases for each ultrasonic transducer 9 and each preamplifier 21 in order to focus an ultrasonic beam on an arbitrary point. Although a high potential difference is generated between the preamplifiers 21, the diode 25 and the diode 26 prevent the backflow of current.

(3-3. Effect)
As described above, also in the third embodiment, the same effects as those in the first embodiment and the second embodiment can be obtained.
Further, since the number of parts of the high voltage switch can be reduced regardless of the number of ultrasonic transducers, the cost burden can be reduced.

(4. Other)
The preferred embodiments of the ultrasonic diagnostic apparatus according to the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea disclosed in the present application, and these are naturally within the technical scope of the present invention. Understood.

Configuration diagram of the ultrasonic diagnostic apparatus 1 Internal circuit diagram of ultrasonic probe 2 The figure which shows the control signal 31 of switch 23 and switch 24 Internal circuit diagram of ultrasonic probe 2a Internal circuit diagram of ultrasonic probe 2b

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ......... Ultrasonic diagnostic apparatus 2, 2a, 2b ......... Ultrasonic probe 3 ......... Transmission circuit 4 ......... Reception circuit 5 ......... Transmission / reception separation circuit 6 ......... Control part 7 ......... Image processing unit 8... Image display unit 9... Ultrasound transducer 10... Transceiver 11 ..... Cable 21 ..... Preamplifier 22 ..... TR switch 23, 24, 23a, 24a, 23b, 24b ......... Switch 25, 26 ......... Diode (for backflow prevention)
31 ......... Control signal 32 ......... Transmission period 33 ......... Reception period D1, D2 ......... Diodes Vdd, Vss ......... Power supply

Claims (3)

An ultrasonic probe comprising a plurality of ultrasonic transducers for transmitting and receiving ultrasonic waves in a subject, a transmission unit for supplying transmission signals to the ultrasonic transducers, and amplifying reception signals from the ultrasonic transducers An ultrasonic diagnosis comprising: a receiving unit having a plurality of preamplifiers; an image processing unit that forms an ultrasonic image based on a reception signal output from the receiving unit; and an image display unit that displays the ultrasonic image A device,
A first switch for opening and closing a first power supply terminal of the preamplifier connected to a first power supply; a second switch for opening and closing a second power supply terminal of the preamplifier connected to a second power supply; an output terminal of the preamplifier; A third switch formed by a pair of diodes connected in reverse parallel to the ultrasonic transducer; and for each ultrasonic transducer ,
An ultrasonic diagnostic apparatus , wherein the preamplifier is protected by opening the first and second power supply terminals by the first and second switches during transmission of the ultrasonic waves. The ultrasonic diagnostic apparatus according to claim 1, wherein the first and second power terminals are connected to the first and second power sources by the first and second switches when the ultrasonic waves are received .   An ultrasonic probe comprising a plurality of ultrasonic transducers for transmitting and receiving ultrasonic waves in a subject, a transmission unit for supplying transmission signals to the ultrasonic transducers, and amplifying reception signals from the ultrasonic transducers An ultrasonic diagnosis comprising: a receiving unit having a plurality of preamplifiers; an image processing unit that forms an ultrasonic image based on a reception signal output from the receiving unit; and an image display unit that displays the ultrasonic image A device,
  The preamplifier is connected to a power source when receiving the ultrasonic wave, and the preamplifier is disconnected from the power source when transmitting the ultrasonic wave to protect the preamplifier, the output terminal of the preamplifier, and the ultrasonic transducer An ultrasonic diagnostic apparatus comprising a switch formed by a pair of diodes connected in reverse parallel for each of the ultrasonic transducers.

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