JP2010273979A - Ultrasonic probe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic probe capable of releasing an electrical charge of an ultrasonic oscillation suitably and obtaining an ultrasonic signal with high quality. <P>SOLUTION: The ultrasonic probe 3 involves a probe head 5, a plurality of ultrasonic oscillators 8 arranged on the tip side, a signal cable 4 having a plurality of signal wires 21 which are electrically and severally connected to the plurality of ultrasonic oscillators 8, and a connector 6 of the probe side connected to the body side of the ultrasonic diagnostic device. A plurality of resistances 27 are mounted on the surface of the wiring substrate 23 which is stored in a connector housing 22 of the connector 6 on the probe side. Resistances 27 are respectively and electrically connected to the plurality of signal wires 21 of the signal cable 4, and the electrical charge stored in each ultrasonic oscillator 8 is released. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ultrasonic probe used in an ultrasonic diagnostic apparatus.

  Conventionally, in the medical field, an ultrasonic diagnostic apparatus for inspecting and diagnosing a disease using ultrasonic waves has been put into practical use. An ultrasound diagnostic apparatus is a device that transmits and receives ultrasound to and from an organism using an ultrasound probe to display an ultrasound image (for example, a B-mode tomographic image), and observes the movement of an affected area or fetus in real time. Can do.

  In this type of ultrasonic diagnostic apparatus, a plurality of types of ultrasonic probes corresponding to the diagnostic region are prepared in order to appropriately perform examination and diagnosis. For example, a convex probe is used for abdominal examination, a linear probe is used for examination of superficial tissues (thyroid gland and carotid artery), and a phased array probe is used for examination of the heart. Thus, an ultrasonic diagnostic apparatus in which a plurality of types of ultrasonic probes are configured to be detachable is disclosed in Patent Document 1 and the like.

  A plurality of ultrasonic transducers are arranged at the tip of each ultrasonic probe. For example, in a convex probe for abdominal examination, a plurality of ultrasonic transducers are arranged in a fan shape, and in a linear probe for superficial tissue examination, a plurality of ultrasonic transducers are arranged linearly. Then, using the high voltage excitation pulse, each ultrasonic transducer is pulse-excited to vibrate each transducer, thereby outputting ultrasonic waves from the transducer.

  Since each ultrasonic transducer is composed of a piezoelectric element, electric charges are accumulated in the ultrasonic transducer after pulse excitation. For this reason, a resistor for releasing the electric charge of the ultrasonic transducer is provided on the ultrasonic signal receiving circuit side in the ultrasonic diagnostic apparatus.

  By the way, the optimum resistance value for the electric charge releasing resistance differs depending on the type of ultrasonic transducer used in the ultrasonic probe, the type of signal line cable, and the like. This optimum resistance value is determined by the balance between the quality of the ultrasonic signal S passing through the signal line and the return time t1 of the ultrasonic signal S to the reference voltage V1 (see FIG. 4).

  In the ultrasonic diagnostic apparatus, an excitation pulse with a high voltage (for example, a voltage of about ± 50 V to ± 100 V) is used to pulse-excit each ultrasonic transducer in the ultrasonic probe. On the receiving circuit side, since the processing circuit is broken when the high voltage signal is directly inputted, a protection circuit for limiting current and voltage is provided. Then, by providing the protection circuit, the reception circuit takes in the ultrasonic signal S in a state where a signal of a predetermined voltage or higher is removed (see FIG. 5).

  The signal of the reflected wave at the diagnostic site at a close distance from the probe surface is included in the gentle signal waveform portion S1 when the signal voltage returns to the reference voltage V1. For this reason, when the return time t1 to the reference voltage V1 becomes long, the signal is removed by the protection circuit. Therefore, a resistance for releasing the charge is provided, and the reflected wave signal of the diagnostic region at a close distance from the probe surface is captured by quickly dropping the voltage of the ultrasonic signal.

JP 2001-104304 A

  However, in the conventional ultrasonic diagnostic apparatus, since the resistance for releasing the charge is arranged on the receiving circuit on the apparatus main body side, the optimum resistance value according to the type of the ultrasonic probe cannot be adopted. . That is, in the conventional ultrasonic diagnostic apparatus, resistors having an average resistance value are arranged in consideration of electric charges accumulated in the respective ultrasonic transducers for the various ultrasonic probes to be mounted.

  Also, in the ultrasonic diagnostic apparatus, resistors with different resistance values are arranged for each type of ultrasonic probe, and a switching circuit is provided to signal a resistance with an optimum resistance value according to the type of ultrasonic probe to be mounted. A configuration for connecting to a line is also conceivable. In this case, it is necessary to use a circuit element that can withstand high voltage as the switching circuit, resulting in increased component costs. Furthermore, there is a problem that signal loss occurs in the switching circuit portion and the quality of the ultrasonic signal is degraded.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an ultrasonic probe capable of appropriately releasing the charge of an ultrasonic transducer and obtaining a high-quality ultrasonic signal. is there.

  In order to solve the above problems, the invention described in means 1 is an ultrasonic probe used in an ultrasonic diagnostic apparatus that transmits and receives ultrasonic waves and displays an ultrasonic image based on the obtained ultrasonic signals. A plurality of ultrasonic waves that are arranged on the distal end side of the probe main body and that are vibrated by pulse excitation to output ultrasonic waves and receive reflected waves of the ultrasonic waves and convert them into electric signals A transducer, a probe-side connector connected to a body-side connector provided on the ultrasound diagnostic apparatus body side, and an electrical connection to each of the plurality of ultrasound transducers, and transmitting / receiving signals via the probe-side connector A signal cable having a plurality of signal lines to be transmitted to the ultrasonic diagnostic apparatus main body side, and electrically connected to the plurality of signal lines, respectively, so that the pulse excitation after the pulse excitation The ultrasonic probe is characterized in that a plurality of resistors to release the number of charges of the ultrasonic vibrator and the gist thereof.

  Therefore, according to the invention described in the means 1, a plurality of ultrasonic transducers are arranged on the distal end side of the probe body, and a plurality of signal lines of the signal cable are connected to each ultrasonic transducer. Each signal line of the signal cable is connected to the main body side connector via the probe side connector. A transmission signal is transmitted from the ultrasonic diagnostic apparatus main body side to each ultrasonic transducer via the probe-side connector and signal line, and each ultrasonic transducer is pulse-excited by the transmission signal. As a result, the ultrasonic transducer vibrates and ultrasonic waves are output. In addition, after the reflected ultrasonic wave is received by the ultrasonic transducer and converted into an electrical signal, the received signal (ultrasonic signal) of the reflected wave is sent to the ultrasonic diagnostic apparatus main body via each signal line and the probe-side connector. Communicated. In the ultrasonic diagnostic apparatus main body, an ultrasonic image is generated and displayed based on the ultrasonic signal. Here, electric charges are accumulated in each ultrasonic transducer after pulse excitation. This charge is released through a plurality of resistors connected to each signal line. In the present invention, the charge release resistor is not provided on the ultrasonic diagnostic apparatus main body side as in the prior art, but is provided on the ultrasonic probe side. In this case, the charge accumulated in each ultrasonic transducer differs depending on the type of the ultrasonic probe, but a resistor having an appropriate resistance value corresponding to the charge can be provided in each ultrasonic probe. The electric charge of the sonic transducer can be released quickly. As a result, a high-quality ultrasonic signal can be obtained, and an ultrasonic image can be accurately displayed.

  The invention described in means 2 is that, in the means 1, the wiring board is accommodated in the connector housing of the probe-side connector, and is connected in series to the wiring board in the middle of the plurality of signal lines. The gist is that the plurality of inductors and the plurality of chip resistors as the plurality of resistors are surface-mounted.

  According to the invention described in means 2, the wiring board is accommodated in the connector housing of the probe-side connector, and a plurality of inductors are surface-mounted on the wiring board. The plurality of inductors are connected in series in the middle of a plurality of signal lines connected to each ultrasonic transducer, and impedance matching is performed by each inductor. A charge release chip resistor is surface-mounted on the wiring board in the connector housing together with the inductors. In this case, it is not necessary to provide a space for mounting the chip resistor on the probe body side, so that an increase in the size of the probe body can be avoided. Further, by mounting a chip resistor for releasing a charge on an existing wiring board on which an inductor is surface-mounted, an increase in component costs can be suppressed.

  According to the invention described in means 3, in the means 2, one end of the plurality of chip resistors is electrically connected to a terminal on the ultrasonic diagnostic apparatus main body side of the plurality of inductors in the plurality of signal lines, The gist is that the other ends of the plurality of chip resistors are electrically connected to a ground pattern on the wiring board.

  Therefore, according to the invention described in the means 3, since the chip resistor for releasing the charge is connected to the terminal on the ultrasonic diagnostic apparatus main body rather than the plurality of inductors in the plurality of signal lines, the influence on the impedance matching by the inductor Can be suppressed.

  As the chip resistor, resistors having the same resistance value may be used. In this case, the manufacturing cost of the ultrasonic probe can be suppressed. In addition, the accumulated charges may be different for each ultrasonic transducer due to manufacturing variations. In that case, it is preferable to use a resistor having a different resistance value suitable for the charge of each ultrasonic transducer as the chip resistor.

  As described in detail above, according to the first to third aspects of the invention, it is possible to appropriately release the charges of the ultrasonic transducer and obtain a high-quality ultrasonic signal.

1 is a front view showing an ultrasonic diagnostic apparatus according to an embodiment. The block diagram which shows the electrical constitution of an ultrasonic diagnosing device. The block diagram which shows the electrical constitution of an ultrasonic probe. The time chart which shows the signal waveform before and behind pulse excitation. The time chart which shows the signal waveform after passing through a protection circuit.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a front view showing an ultrasonic diagnostic apparatus 1 according to the present embodiment, and FIG. 2 is a block diagram showing an electrical configuration of the ultrasonic diagnostic apparatus 1.

  As shown in FIGS. 1 and 2, the ultrasonic diagnostic apparatus 1 includes an ultrasonic diagnostic apparatus main body 2 and an ultrasonic probe 3 connected to the apparatus main body 2. Specifically, the ultrasonic probe 3 includes a signal cable 4, a probe head 5 (probe main body) connected to the distal end of the signal cable 4, and a probe-side connector 6 provided at the base end of the signal cable 4. The ultrasonic diagnostic apparatus main body 2 is provided with a connector 7 (main body side connector 7), to which the probe side connector 6 of the ultrasonic probe 3 is connected.

  As shown in FIG. 2, the probe head 5 of the ultrasonic probe 3 has a plurality of ultrasonic transducers 8 arranged in a fan shape at the tip, and the tip is in contact with the object to be inspected 9. Ultrasound is transmitted and received in the state where The ultrasonic probe 3 is, for example, a convex probe for performing convex electronic scanning, and scans a 5 MHz ultrasonic wave in a fan shape. In the ultrasonic diagnostic apparatus 1, different types of ultrasonic probes such as a linear probe and a phased array probe are detachable in addition to the convex probe.

  The ultrasonic diagnostic apparatus main body 2 includes a transmission circuit 11, a reception circuit 12, a signal processing circuit 13, an image processing circuit 14, a display device 15, and the like.

  The transmission circuit 11 includes a plurality of delay circuits (not shown) corresponding to the number of elements (for example, 128 elements) of the ultrasonic transducer 8 in the probe head 5, and a drive pulse delayed according to each ultrasonic transducer 8. (Transmission signal) is transmitted. Then, each ultrasonic transducer 8 of the probe head 5 is pulse-excited by the drive pulse. As a result, each ultrasonic transducer 8 vibrates, and ultrasonic waves are output from each ultrasonic transducer 8 so as to focus at a predetermined irradiation point.

  The reception circuit 12 includes a protection circuit (for example, a current limiter formed of a diode bridge) 16, a signal amplification circuit (not shown), an A / D conversion circuit, a delay circuit, and a phasing addition circuit. In the reception circuit 12, a reception signal (reflection wave signal as an ultrasonic signal) of each reflected wave received by each ultrasonic transducer 8 in the ultrasonic probe 3 is taken in via the current limiter 16. Each reflected wave signal is amplified and A / D converted, and a delay time considering reception directivity is added to each reflected wave signal, and then phased and added. By this addition, the phase difference between the reception signals of the ultrasonic transducers 8 is adjusted.

  The signal processing circuit 13 includes a logarithmic conversion circuit, an envelope detection circuit, and the like (not shown). In the signal processing circuit 13, the reflected wave signal received by the receiving circuit 12 is logarithmically converted, and then the envelope of the signal is detected. Then, a reflected wave signal that has undergone signal processing such as logarithmic conversion and envelope detection in the signal processing circuit 13 is output to the image processing circuit 14.

  The image processing circuit 14 performs image processing based on the reflected wave signal output from the signal processing circuit 13 to generate image data of an ultrasonic image (B mode image). Specifically, the image processing circuit 14 generates image data having luminance corresponding to the amplitude (signal intensity) of the reflected wave signal. The image data generated by the image processing circuit 14 is transferred to the display device 15. Based on the image data, an ultrasonic image of the inspection object 9 is displayed on the display device 15 in black and white shades. The display device 15 is, for example, a display such as an LCD or a CRT, and is used to display an ultrasonic image of the inspection object 9 and an input screen for various settings.

  Next, the configuration of the ultrasonic probe 3 in the present embodiment will be described in detail.

  As shown in FIG. 3, in the ultrasonic probe 3, a plurality of signal lines 21 provided in the signal cable 4 are electrically connected to the ultrasonic transducers 8 arranged at the tip of the probe head 5. It is connected. In the probe-side connector 6 connected to the base end of the signal cable 4, a wiring board 23 is accommodated in the connector housing 22.

  The wiring board 23 is provided with a wiring pattern 24 and a ground pattern 25 connected to each signal line 21 of the signal cable 4, and a plurality of inductors connected in series to each signal line 21 via each wiring pattern 24. 26 is surface mounted. By providing these inductors 26, impedance matching of each signal line 21 is performed, and loss (transmission loss) of the ultrasonic signal propagating through each signal line 21 is reduced. The wiring board 23 for performing impedance matching is an existing configuration adopted in a general ultrasonic probe, and is usually provided in a connector housing 22 that is an end of the ultrasonic probe 3.

  Furthermore, in addition to the plurality of inductors 26, a plurality of chip resistors 27 are surface-mounted on the wiring board 23 of the present embodiment. These chip resistors 27 are electric charge releasing resistors for releasing electric charges accumulated in the ultrasonic transducers 8 after pulse excitation, and are connected in parallel to the ultrasonic transducers 8. Specifically, in the wiring pattern 24 of each signal line 21, one end of the chip resistor 27 is electrically connected to a terminal 28 provided closer to the device body than the inductor 26, and the other end of the chip resistor 27 is electrically connected to the ground pattern 25. Connected. In the present embodiment, the inductor 26 and the chip resistor 27 are respectively provided for all the ultrasonic transducers 8. The resistance value of each chip resistor 27 is set according to the electric charge accumulated in the ultrasonic transducer 8 and has the same resistance value (for example, 100Ω).

  Therefore, according to the present embodiment, the following effects can be obtained.

  (1) In the ultrasonic probe 3 of the present embodiment, a plurality of chip resistors 27 for releasing charges are connected to the plurality of signal lines 21 connected to the plurality of ultrasonic transducers 8, respectively. When each ultrasonic transducer 8 is pulse-excited to transmit ultrasonic waves in the ultrasonic probe 3, charges are accumulated in each ultrasonic transducer 8, and the charges are released via the signal line 21 and the chip resistor 27. Is done. Each chip resistor 27 is provided not on the ultrasonic diagnostic apparatus main body 2 side as in the prior art but on the ultrasonic probe 3 side. For this reason, the resistor 27 having an optimum resistance value according to the type of the ultrasonic probe 3 can be used, and the charge of each ultrasonic transducer 8 can be released quickly. As a result, a high-quality ultrasonic signal can be obtained using the ultrasonic probe 3, and an ultrasonic image can be accurately displayed on the display device 15 based on the ultrasonic signal.

  (2) In the ultrasonic probe 3 of the present embodiment, the chip resistor 27 is surface-mounted together with the inductor 26 on the wiring board 23 housed in the connector housing 22 of the probe-side connector 6. In this case, since it is not necessary to provide a space for mounting the chip resistor 27 on the probe head 5 side, an increase in the size of the probe head 5 can be avoided. Further, by mounting the chip resistor 27 for releasing the charge on the existing wiring board 23 on which the inductor 26 is surface-mounted, the component cost can be reduced. Incidentally, a method of newly providing an attachment-type relay connector between the probe-side connector 6 and the body-side connector 7 and mounting the chip resistor 27 on the wiring board accommodated in the relay connector is conceivable. In this case, in addition to increasing the cost of components such as a connector housing and a wiring board, transmission loss of ultrasonic signals also occurs due to contact resistance between the connectors. On the other hand, when the existing wiring board 23 accommodated in the probe-side connector 6 is used as in the present embodiment, the wiring pattern on the wiring board 23 is redesigned and the wiring board 23 is relatively inexpensive. A simple chip resistor 27 may be mounted. In this way, it is possible to suppress an increase in component costs and signal transmission loss.

  (3) In the present embodiment, since the chip resistor 27 for releasing the charge is connected to the terminal 28 closer to the device body 2 than the plurality of inductors 26 in the wiring board 23, the influence on the impedance matching by the inductor 26 is affected. Can be suppressed. Incidentally, in the ultrasonic probe 3, the inductor 26 is provided in order to perform impedance matching of the signal cable 4. However, when the chip resistor 27 is connected to the probe head 5 side rather than the inductor 26, the effect of impedance matching by the inductor 26 is achieved. Will disappear. In this case, the impedance matching needs to be readjusted, but the problem can be avoided by connecting the chip resistor 27 to the terminal 28 on the apparatus body 2 side as in the present embodiment.

  (4) In the ultrasonic probe 3 of the present embodiment, since the charge release resistors 27 are provided for all the ultrasonic transducers 8, the charges accumulated in the ultrasonic transducers 8 can be reliably detected. Can be released to. In addition, since the plurality of chip resistors 27 have the same resistance value, the manufacturing cost of the ultrasonic probe 3 can be reduced as compared with the case where resistors having different resistance values are used.

  In addition, you may change embodiment of this invention as follows.

  In the ultrasonic diagnostic apparatus 1 of the above embodiment, the current limiter is used as the protection circuit 16 that protects the reception circuit 12, but a voltage limiter may be used as the protection circuit. In this case, each chip resistor 27 is mounted on the wiring board 23 so as to be connected in series to each ultrasonic transducer 8, and is accumulated in each ultrasonic transducer 8 by each chip resistor 27. Adjust the charge discharge speed. Even with this configuration, it is possible to provide each ultrasonic probe 3 with a resistance having an appropriate resistance value according to the type of the ultrasonic probe 3, and to quickly store the charges accumulated in each ultrasonic transducer 8. Can be released to. It is also possible to adopt a configuration including both a current limiter chip resistor and a voltage limiter chip resistor. In this case, for example, the latter is preferably set to a lower resistance value than the former.

  In the above embodiment, the chip resistor 27 for releasing the charge is mounted on the wiring board 23 housed in the probe-side connector 6, but the present invention is not limited to this. For example, the chip resistor 27 may be provided on a wiring board accommodated in the housing of the probe head 5.

  In the above embodiment, the chip resistor 27 having the same resistance value is used as the charge release resistor, but the present invention is not limited to this. For example, the charge accumulated for each ultrasonic transducer 8 may vary depending on manufacturing variations. In this case, as the chip resistor 27, a resistor having a different resistance value according to the electric charge of each ultrasonic transducer 8 may be used.

  Next, in addition to the technical ideas described in the claims, the technical ideas grasped by the above-described embodiments are listed below.

  (1) In any one of the means 1 to 3, the receiving circuit provided on the ultrasonic diagnostic apparatus main body side is provided with a current limiter as a protection circuit, and the plurality of resistors are provided in each ultrasonic transducer. An ultrasonic probe characterized by being connected in parallel.

  (2) In any one of the means 1 to 3, the receiving circuit provided on the ultrasonic diagnostic apparatus main body side is provided with a voltage limiter as a protection circuit, and the plurality of resistors are connected to each ultrasonic transducer. An ultrasonic probe characterized by being connected in series.

  (3) The ultrasonic probe according to any one of the means 1 to 3, wherein the plurality of resistors have the same resistance value.

  (4) The ultrasonic probe according to any one of the means 1 to 3, wherein the plurality of resistors have different resistance values.

  (5) The ultrasonic probe characterized in that in the means 2, all the transducers in the plurality of ultrasonic transducers are provided with the inductor and the resistor, respectively.

  (6) The ultrasonic probe according to claim 1, wherein a wiring board is housed in the housing of the probe body, and the plurality of resistors are mounted on the wiring board.

DESCRIPTION OF SYMBOLS 1 ... Ultrasonic diagnostic apparatus 2 ... Ultrasonic diagnostic apparatus main body 3 ... Ultrasonic probe 4 ... Signal cable 5 ... Probe head as a probe main body 6 ... Probe side connector 7 ... Main body side connector 8 ... Ultrasonic transducer 21 ... Signal line 22 ... Connector housing 23 ... Wiring board 25 ... Grounding pattern 26 ... Inductor 27 ... Chip resistor 28 ... Terminal

Claims (3)

An ultrasound probe used in an ultrasound diagnostic apparatus that transmits and receives ultrasound and displays an ultrasound image based on the obtained ultrasound signal,
A probe body;
A plurality of ultrasonic transducers arranged on the distal end side of the probe body, oscillating by being pulse-excited and outputting ultrasonic waves, receiving reflected waves of the ultrasonic waves and converting them into electrical signals;
A probe-side connector connected to a main body-side connector provided on the ultrasonic diagnostic apparatus main body side;
A signal cable electrically connected to each of the plurality of ultrasonic transducers and having a plurality of signal lines for transmitting and receiving transmission / reception signals to the ultrasonic diagnostic apparatus main body via the probe-side connector;
An ultrasonic probe comprising: a plurality of resistors that are electrically connected to the plurality of signal lines, respectively, to release charges of the plurality of ultrasonic transducers after pulse excitation.   A wiring board is accommodated in the connector housing of the probe-side connector, and on the wiring board, a plurality of inductors connected in series in the middle of the plurality of signal lines, and the plurality of resistors, respectively. The ultrasonic probe according to claim 1, wherein the plurality of chip resistors are surface-mounted.   One end of the plurality of chip resistors is electrically connected to a terminal on the ultrasonic diagnostic apparatus main body side with respect to the plurality of inductors in the plurality of signal lines, and the other end of the plurality of chip resistors is connected to the wiring The ultrasonic probe according to claim 2, wherein the ultrasonic probe is electrically connected to a ground pattern on the substrate.

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