JPH06225881A - Ultrasonic diagnostic device - Google Patents

Abstract

PURPOSE:To provide an ultrasonic diagnostic device provided with a low-cost ultrasonic probe capable of changing the tuning frequency during reception and capable of freely selecting the tuning frequency. CONSTITUTION:The reflected wave received by a vibrator in a probe 4 is outputted to an ultrasonic diagnostic device main body side without being corrected, a fixed coil 14 and a variable capacitor 18 variable for the capacitor by a controller 16 are connected in parallel with input signal lines corresponding to output signal lines of the vibrator of a main body side input section 12, and the tuning frequency can freely be selected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to an ultrasonic diagnostic apparatus which transmits and receives ultrasonic waves by a probe into an object and obtains ultrasonic images by the reflected waves.

[0002]

2. Description of the Related Art Ultrasonic diagnostic apparatuses have come into widespread use today because they do not need to be irradiated with harmful radiation such as X-rays and are relatively small and inexpensive. .

This ultrasonic diagnostic apparatus transmits ultrasonic waves,
This reflected wave is received, and an ultrasonic image is obtained based on this reflected wave. The probe transmits and receives this ultrasonic wave. Ultrasonic diagnostic equipment is available for fetuses, gallbladder, liver,
It is used in a wide range of diagnostic fields such as the heart, and a probe having a shape corresponding to the diagnostic content is selected and used.
Therefore, those having various shapes and frequency characteristics are used depending on the region to be diagnosed, the type of ultrasonic image to be obtained, and the like. 2 (a) to 2 (d) show typical probe shapes. Figure 2 (a) is a linear type, Figure 2 (b) is a convex type, and Figure 2
(c) is a sector type, and FIG. 2 (d) is a radial type. As shown in FIG. 3, these probes 30 form a probe 36 with a cable 32 and a connector 34, and one ultrasonic diagnostic apparatus 38 is usually provided with 3 to 4 probes. A plurality of transducers (not shown) are arranged in an array inside the probe 30, and each transducer transmits and receives ultrasonic waves.

The conventional probe 36 is a dedicated probe in which the frequency to be used is set depending on the region to be diagnosed, the depth, the type of ultrasonic image to be obtained, and the like, and receives the best reflected wave under the set conditions. However, the dedicated probe 36
Is a high-frequency component of the reflected wave of the ultrasonic wave reflected by the subject due to a parallel capacitance component such as a coil and a condenser (not shown) that is a component of the vibrator, a parallel capacitance component of the input portion of the ultrasonic diagnostic apparatus main body side, or the like. As a result of scraping off the low-frequency components, the sensitivity of the ultrasonic image displayed on the display is reduced.

Therefore, in the conventional probe, in order to cancel the parallel capacitance component, synchronize the specific frequency on the probe side with the frequency of the reflected wave received, and improve the ultrasonic wave reception sensitivity, as shown in FIG. 36 connectors 3
The coils 40, which are frequency tuning means, are connected to the output sections corresponding to the respective vibrators inside the unit 4. Then, after performing frequency tuning, the ultrasonic diagnostic apparatus main body side input unit 42
It has a function to input to.

[0006]

However, for example, 12
In the case of the probe 36 having eight oscillators, in order to cancel the parallel capacitance component and tune to a specific frequency on the probe side, the coil 40, which is 128 frequency tuning means selected for this probe 36, is used. In addition, it is necessary to make the constant of the coil 40 precise in order to match the tuning frequency with the tuning frequency as much as possible, and it is necessary to use a variable coil that can be finely adjusted. Further, since there is a dedicated probe for each frequency, if there are 5 types of probes having 128 transducers, 640 variable coils are required, which causes a problem of high cost. Further, there has been a demand for changing the tuning frequency to change the reception frequency band during ultrasonic diagnosis so that the reflected waves reflected from different depths can be received in the best condition.

The present invention has been made in view of the above problems, and an object thereof is to be able to change the tuning frequency during reception of a reflected wave and to freely select the tuning frequency. An object of the present invention is to provide an ultrasonic diagnostic apparatus having a low-cost ultrasonic probe that can be used.

[0008]

In order to solve the above problems, an ultrasonic diagnostic apparatus according to the present invention has a plurality of ultrasonic waves for transmitting ultrasonic waves into a subject and receiving reflected waves. An ultrasonic diagnostic apparatus having an ultrasonic transducer in which transducers are arranged and performing in-vivo ultrasonic image diagnosis based on a received signal, is provided in parallel with an input signal line on the ultrasonic diagnostic apparatus main body side. A parallel coil to the input signal line on the ultrasonic diagnostic apparatus body side, and a fixed coil having an inductance smaller than the inductance that tunes to the capacitive reactance of the output signal section of the transducer and the input signal section on the ultrasonic diagnostic apparatus body side. And a control unit for controlling the capacitance of the variable capacitance type passive element.

[0009]

In the ultrasonic diagnostic apparatus according to the present invention having the above-mentioned structure, the ultrasonic diagnostic apparatus main body side has a plurality of transducer output signal portions provided at the tip of the probe, and The ultrasonic diagnostic equipment uses a fixed coil having an inductance smaller than the inductance that tunes to the capacitive reactance of the input signal section on the main body side of the ultrasonic diagnostic equipment and a variable capacitance type passive element so that the frequency band is tuned to the desired frequency of the reflected wave. Since it can be set on the side, it is possible to receive tomographic images with different depths in the best state by changing the tuning frequency band during reception of the reflected wave. Further, since the frequency is tuned on the ultrasonic diagnostic apparatus side, frequency tuning means such as a variable coil is not required on the probe side, and adjustment work at the time of shipping is also unnecessary.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the configuration of a probe 2 of an ultrasonic diagnostic apparatus according to a preferred embodiment of the present invention, and an ultrasonic diagnostic apparatus main body side input section 12 (hereinafter referred to as the main body side input section 12). It is a schematic diagram.

As shown in FIG. 1, the probe 2 of the ultrasonic diagnostic apparatus according to this embodiment uses a cable 6 to receive reflected waves of ultrasonic waves received by a plurality of transducers (not shown) arranged inside the probe 4. Output from the probe side connector 8 via the, and input from the main body side input unit 12 to the main body side of the ultrasonic diagnostic apparatus, image processing is performed, and an ultrasonic image is formed.

A feature of the present invention is that first, the reflected wave received by the transducer inside the probe 4 is output to the ultrasonic diagnostic apparatus main body side without correction, and secondly, the main body side input section. 12
In the input signal line corresponding to each output signal line of the oscillator of,
That is, the fixed coil 14 and the variable capacitor 18 whose capacity is changed by the control unit 16 are connected in parallel.

That is, the reflected wave received by the vibrator inside the probe 4 is high frequency component or low frequency component of the electric signal due to the reflected wave due to impedance of parallel capacitance component of the vibrator or cable. Is output to the ultrasonic diagnostic apparatus main body side in a state of being scraped off. On the other hand, the fixed coil 14 of the main body side input section 12 has an inductance smaller than an inductance that tunes to the capacitive reactance of the output signal section of the probe 2 side and the input signal section of the ultrasonic diagnostic apparatus main body side. . That is, the one smaller than the inductance tuned to the minimum capacitive reactance of the input / output signal section is selected. When the capacitance reactance changes to change the inductance, the variable capacitor 18 that can be changed by the control unit 16 is used.

The operation of the ultrasonic diagnostic apparatus configured as above will be described.

A commonly used probe 2 is 2 MHz
.About.7.5 MHz, for example, the minimum value of the inductance of the fixed coil 14 required to cancel the parallel capacitance component generated by the probe for 3 MHz and tune it to the frequency on the probe side is about several .mu.H. Is.

Next, when the probe for 3.5 MHz or 5 MHz is used, the variable capacitor 18 connected in parallel to the input signal line to which the fixed coil 14 is connected in parallel is controlled by the control unit 16. By controlling and changing the capacitance, the impedance is changed to 3.5M.
The parallel capacitance component generated in each of the Hz probe and the 5 MHz probe is canceled. It is preferable that the variable capacitor 18 has a variable capacitance in the range of several pF to several hundred pF.

Further, when the probe for 5 MHz is used as described above, the variable capacitor 18 is adjusted so as to improve the sensitivity of the reflected wave at the portion of 5 MHz and improve the quality of the image formed. It is possible to adjust the condenser 18 and tune the frequency of the reflected wave received by the probe for 5 MHz at 6 MHz to improve the sensitivity of the reflected wave in the 6 MHz portion, thereby improving the quality of the image formed. You can

In the above embodiment, the variable capacitor is used as the variable capacitance type passive element, but the variable capacitor is not limited to this, and the same effect can be obtained by a variable capacitance diode or the like whose impedance value can be changed.

[0019]

As described above, in the ultrasonic diagnostic apparatus according to the present invention, only the ultrasonic diagnostic apparatus main body cancels the generated parallel capacitance component and synchronizes with the reflected wave from the subject. Therefore, the coil for tuning the frequency on the individual probe side is not required, and the manufacturing cost and the adjustment cost at the time of shipping can be reduced. Also, since the tuning frequency can be changed even during reception of the reflected wave, it is possible to always obtain the best reception sensitivity for a reception signal whose frequency band changes depending on the depth of the subject, so that one probe can be used. Thus, it is possible to obtain high quality ultrasonic images of portions of the subject having different depths.

[Brief description of drawings]

FIG. 1 is a schematic view showing a configuration of a probe of an ultrasonic diagnostic apparatus and an ultrasonic diagnostic apparatus main body side input unit according to an embodiment of the present invention.

FIG. 2 is a diagram showing various probe shapes.

FIG. 3 is a diagram showing an appearance of an ultrasonic diagnostic apparatus.

FIG. 4 is a schematic diagram showing a configuration of a probe of a conventional ultrasonic diagnostic apparatus and an ultrasonic diagnostic apparatus main body side input unit.

[Explanation of symbols]

 2 probe 4 ultrasonic probe 8 probe side connector 12 ultrasonic diagnostic apparatus body side input section 14 fixed coil 16 control section 18 variable capacitor

Claims (1)

[Claims] 1. An ultrasonic probe in a living body, comprising an ultrasonic probe having a plurality of transducers arranged for transmitting ultrasonic waves into a subject and receiving reflected waves. In an ultrasonic diagnostic apparatus for performing image diagnosis, the output signal section of the transducer provided in parallel with the input signal line of the ultrasonic diagnostic apparatus main body side, and the capacitive reactance of the input signal section of the ultrasonic diagnostic apparatus main body side A fixed coil having an inductance smaller than the inductance tuned to, a variable capacitance type passive element provided in parallel with the input signal line on the ultrasonic diagnostic apparatus main body side, and a control unit for controlling the capacitance of the variable capacitance type passive element An ultrasonic diagnostic apparatus comprising: