JPH04132545A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

PURPOSE:To obtain a proper ultrasonic tomographic image by causing an ultrasonic vibrator to vibrate being moved utilizing a reaction when an SAW device repels an ambient ultrasonic transmission material to perform an ultrasonic sanning. CONSTITUTION:An SAW device 7 is excited with the supply of a signal from a signal source 24 to an electrode 2 to generate a surface wave. Ultrasonic transmission material 9 in the perimeter of the SAW device 7 is repelled being turned to particles so that kinetic energy is generated in the SAW device 7 by the resulting reaction to allow the moving of an ultrasonic vibrator 8 in an outer cylindrical direction of a shaft 6 as well. Therefore, if a drive signal is supplied to the ultrasonic vibrator 8, an ultrasonic scanning is accomplished being moved. In this case, the scanning speed of the ultrasonic vibrator 8 is controlled by converting it into a speed signal with an F/V converter 26. The speed signal is compared with a reference power source 27 to determine the scanning rate of the ultrasonic vibrator 8 and the signal obtained by comparison controls a gain of a variable gain amplifier 23. Thus, an ultrasonic scanning can be realized rotating the ultrasonic vibrator 8 evenly.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention rotates and oscillates an ultrasonic transducer within a body cavity to excite it, and transmits the echoes from the object to be examined as a signal using an external a-measuring device. The present invention relates to an ultrasonic diagnostic apparatus that obtains ultrasonic tomographic images through processing.

[Conventional technology]

Among the ultrasonic probes used in ultrasonic diagnostic apparatuses, those inserted into body cavities have a configuration as shown in FIG. 10. That is, the insertion section 41 is provided with an ultrasonic probe 42 at its tip, and this ultrasonic probe 42 rotates through a flexible shaft 45 that extends inside the insertion section 41 to the sub-operation section 43. While doing so, perform an ultrasound scan. In this case, it is the motor 44 provided within the sub-scanning section 43 that applies rotational force to the flexible shaft 45. For this reason, the flexible shaft 45 that transmits the rotational force cannot properly transmit the rotational force, resulting in uneven rotation of the ultrasound probe 42.

In order to solve this problem, Japanese Patent Application Laid-Open No. 62-233150
The publication states that a drive motor is installed in a housing that transmits ultrasonic waves, an ultrasonic vibrator is attached to the motor shaft of the drive motor inside the housing, and the ultrasonic vibrator is directly rotated by the drive motor. Disclosed. In other words, the motor is provided close to the ultrasonic transducer.

[The issue that the issue is trying to solve]

However, the conventional technology attempts to rotate the ultrasonic probe inside the tip of the insertion tube using a drive motor also installed inside the tip, which has the problem of increasing the diameter of the tip. there were.

The present invention is proposed to solve the above-mentioned problems.
Accurate ultrasonic tomographic images can be obtained by rotating the ultrasonic probe without rotational unevenness despite the miniaturized tip without providing a drive member for the ultrasonic probe such as a motor within the tip of the insertion tube. The purpose is to provide an ultrasonic diagnostic device that can perform

(Means and Effects for Solving the Problems) In order to achieve the above object, the present invention provides an ultrasound transducer at the tip of an insertion section into a body cavity, and generates ultrasound tomographic images based on the echoes of the emitted ultrasound waves. In the ultrasonic diagnostic apparatus thus obtained, a SAW device that uses surface acoustic waves and a tg S A W
A drive control unit that controls the drive of the device is provided, and the SAW
This ultrasonic diagnostic device uses the reaction when the device repels surrounding ultrasonic transmitting substances to move and excite an ultrasonic transducer to perform ultrasonic scanning.

An ultrasonic transmitting substance is brought into contact with the SAW device that generates surface acoustic waves in this way, and kinetic energy is generated by utilizing the phenomenon in which the ultrasonic transmitting substance is scattered in one direction due to the SAW jet effect, resulting in smooth rotation. The ultrasound probe can be rotated.

[Examples] Examples of the present invention will be described in detail below with reference to the drawings.
. First, the characteristics of the SAW device will be explained with reference to FIG. A comb-shaped electrode (ID
T) Provide 2. Note that FIG. 2 is a plan view of the comb-shaped electrode 2 disposed on the substrate 1. This electrode 2 is applied with a voltage of about 50 MHz, 10
When the substrate is excited as shown by the arrow X at a period of about 0 Hz, the substrate moves in the wave shape shown in the figure.

Then, the ultrasonic transmitting substance in contact with the substrate 1 becomes SAW.
Due to the effect, it scatters in one direction (arrow Y).

The small circle 3 indicates scattered particles of the ultrasonic transmitting substance. When it scatters, a reaction occurs on the SAW device, so the force of this scattering is used as kinetic energy.

FIG. 3 shows an example in which the first example of the above-described SAW device is applied to an ultrasonic probe 4. The insertion portion 5 of the ultrasonic probe 4 is provided with a flexible shaft 6, and a SAW device 7 is movably provided on the shaft 6. Specifically, the shaft 6 passes through the inside of the SAW device 7, and the SAW device 7 is designed to be able to rotate in the direction of the outer circumference of the shaft 6, and also to be able to move in the direction in which the shaft 6 extends. It is. Furthermore, an ultrasonic transducer 8 is provided on the shaft 6 near the base of the probe (not shown) and is connected to the SAW device 7 and moves in conjunction with the movement of the SAW device 7. Further, the area around the shaft 6, the SAW device 7, and the ultrasonic transducer 8 is filled with an ultrasonic transmitting substance 9 having good ultrasonic transmittance, such as water. Further, a linear encoder 10 is provided near the ultrasonic transducer 8 to detect the scanning position of the ultrasonic transducer 8. A signal cable 11 is connected to the SAW device 7 to transmit electrical signals to the electrodes, and a signal cable 12 is connected to the ultrasonic transducer 8 to transmit electrical signals. A signal cable 13 is connected to the linear encoder 10, and each of the signal cables 0 or more for detecting signals is led to an external observation device 14.

The observation device 14 is provided with a pulser circuit 15 and is connected to supply a signal to the ultrasonic transducer 8 so as to emit ultrasonic waves. The echo from the object to be examined after emitting the ultrasound is converted into an electrical signal and then sent to the amplifier 1.
6 (including detection), digitized by the ^/D converter 17, and then converted to a digital scan converter (D
SC) 1B is converted into an image and displayed on the monitor 19 in B mode.

On the other hand, the signal cable 1 connected to the SAW device 7
1 is connected to the drive control unit 20 together with a signal cable 12 that transmits the position detection signal of the ultrasonic transducer 8, and the SAW
Excitation of the device 7 is controlled to perform linear scanning of the ultrasonic transducer 8.

FIG. 4 is a block diagram showing details of the drive control section 20. A signal cable 11 is connected to both ends of the electrode 20 of the SAW device 7. Then, the signal cable 11
are connected to a changeover switch 21 of the drive control section 20, a power amplifier 22 is connected to one of the switches 21, a variable gain amplifier 23 is connected to the power amplifier 22, and a variable gain amplifier 23 is connected to the variable gain amplifier 23. A signal source 24 is connected. On the other hand, a signal cable 13 connected to the linear encoder 10 is connected to a counter 25 of the drive control section 20 to detect the scan rate of the ultrasonic transducer. The Z phase (origin signal) of the counter 25 is input as a switching signal of the switch 21, and the A phase (position signal) is input as the scan rate control signal of the ultrasonic transducer.
/V converter 26. The A-phase signal indicating the scan rate of the ultrasonic transducer is converted into a voltage by an F/V converter 26, and this voltage is compared with a reference power supply 27 that determines the scan rate of the ultrasonic transducer by a differential amplifier 28. The compared outputs change the amplification degree of the variable gain amplifier 23. Then, the voltage amplitude that excites the SAW device 7 is controlled to keep the scan rate of the ultrasonic transducer constant.
This is selectively provided so that the electrical signal that excites the W device 7 does not saturate the amplifier 16.

To explain the operation of this embodiment configured as described above, the SAW device 7 is configured so that the signal from the signal source 24 is transmitted to the electrode 2.
is excited by being supplied to the surface, producing surface acoustic waves. Then, the ultrasonic transmitting substance around the SAW device 7 is turned into particles and thrown away. At this time, kinetic energy is generated in the SAW device 7 due to the reaction of the flicker.

On the other hand, since the SAW device 7 is installed on the shaft 9 and is movable in the outer circumferential direction of the shaft 9, the ultrasonic transducer 8 connected to the shaft 9 is also moved by movement due to reaction.
This results in movement in the direction of the outer circumference. Therefore, by supplying a drive signal to the ultrasonic transducer 8, ultrasonic scanning can be performed while moving. In this case, the scanning speed of the ultrasonic transducer 8 is controlled by converting the signal (A phase) for detecting the position of the ultrasonic transducer 8 into a speed signal using the F/V converter 26. , ultrasonic transducer 8
is compared with a reference power supply 27 to determine the scan rate of
The compared signals control the gain of variable gain amplifier 23. In this way, the amplitude of the excitation voltage applied to the SAW device 7 changes so that the scan rate of the ultrasonic transducer 8 remains constant. Note that the amplitude value of the signal source 24 itself may be varied by the difference signal between the speed signal and the reference power source 30, or a switch such as a MOSFET may be attached to the output of the power amplifier 22 to vary the duty cycle of the excitation voltage. Needless to say, the scan rate of the ultrasonic transducer can be kept constant.

Next, in order to perform linear scanning, the ultrasonic transducer 8 provided on the shaft 6 may be moved in the direction in which the shaft extends.
For this purpose, the origin signal (Z phase) of the linear encoder 1o is used to change the drive direction and supply a signal to the electrode 2 connected to the power amplifier 22 via the switch 21, thereby changing the direction in which the surface acoustic waves are generated. This is done by changing the direction in which the ultrasonic transmission substance 9 is scattered and by changing the direction of movement of the SAW device moving on the shaft 6.

As described above, in this embodiment, since the ultrasonic transducer 8 can be directly driven by the kinetic energy of the extremely small SAW device 7 provided at the tip, the ultrasonic transducer 8 can be rotated unevenly without enlarging the tip. This means that ultrasonic scanning can be achieved while rotating without any need for rotation.

FIG. 5 shows a second embodiment of the present invention, in which parts corresponding to those in the first embodiment are given the same reference numerals. In this embodiment, an ultrasonic transducer 8 and a SAW device 7 and are joined at the back. Therefore, as the SAW device 7 moves, the ultrasonic transducer 8 can move integrally, so linear scanning can be performed without using a connecting member. The other configurations are almost the same as in the first embodiment.

With this configuration, in addition to having the same effects as described above, the tip length of the ultrasonic probe can be shortened, reducing the pain of the subject and improving operability.

FIG. 6 shows a third embodiment of the present invention, in which an ultrasonic transducer 8 is rotated via a rotating shaft 29, and a SAW is attached to one end of the ultrasonic transducer 8 near the insertion section 5. device 7
has been established. The other configurations are almost the same as in the first embodiment.

With this configuration, in addition to having the same effect as the first embodiment, the SA provided perpendicularly to the rotating shaft 29
The reaction caused by the W device 7 repelling the ultrasonic transmitting substance 9 causes the ultrasonic vibrator 8 to rotate in the direction of the arrow and radially rotate.

FIG. 7 shows a fourth embodiment of the present invention, in which the ultrasonic transducer 8 is provided with the SAW device 7 as in the third embodiment, but the SAW device 7 is arranged point-symmetrically with respect to the rotation axis 29. It is something. The other configurations are the same as those in the first embodiment.

With this configuration, in addition to having the same effects as in the first embodiment, sector scanning can be performed by selectively driving the SAW device 7.

FIG. 8 shows a fifth embodiment of the present invention. In this embodiment, a SAW device 7 and an ultrasonic transducer 8 are arranged axially side by side on a shaft 6 as in the first embodiment. , are provided at positions near the base of the probe so as to face each other with the shaft 6 in between. The other configurations are almost the same as the first embodiment.

With this configuration, in addition to having the same effects as in the first embodiment, radial scanning and linear scanning by the ultrasonic transducer 8 can be performed simultaneously, and a three-dimensional ultrasonic image can be displayed. I can do it.

FIG. 9 shows a sixth embodiment of the present invention, in which the SAW device 7 is provided with a concave curved lens 30 which is an acoustic matching layer. The other configurations are almost the same as in the first embodiment.

With this configuration, when the SAW device 7 is driven, the ultrasonic transmitting substance 9 is thrown off in the A direction, and the ultrasonic probe is rotated in the C direction by the reaction. Further, the ultrasonic wave is transmitted from the ultrasonic transducer 7 through the concave curved lens 30 and radiated in the B direction, and an echo is received on this surface. The other configurations are the same as those in the first embodiment.

With this configuration, in addition to having the same effect as the first embodiment, the kinetic energy of the SAW device can be used for transmitting and receiving ultrasonic waves and for ultrasonic scanning, so the configuration can be simplified and the diameter of the insertion portion can be reduced. It is possible to achieve a smaller diameter.

〔Effect of the invention〕

As described above, in the present invention, the rotation of the ultrasonic probe that performs ultrasonic scanning can be performed using a SAW device provided near the ultrasonic probe. , rotational unevenness can be eliminated and proper ultrasonic scanning can be performed. Furthermore, since only a small element is used, there is no need to increase the diameter of the insertion portion.

[Brief explanation of the drawing]

FIG. 1 is a diagram explaining the operation of the SAW device, FIG. 2 is a plan view of the SAW device, FIG. 3 is a schematic diagram of an ultrasonic diagnostic apparatus using the first embodiment of the present invention, and FIG. The figures are detailed views of the same part, Figure 5 is a sectional view according to the second embodiment of the present invention, Figure 6 is a sectional view according to the third embodiment, and Figure 7 is a sectional view according to the fourth embodiment. 8 is a sectional view according to the fifth embodiment, FIG. 9 is a sectional view according to the sixth embodiment, and FIG. 10 is an external view of an ultrasonic probe according to a conventional example. 1... Substrate 2... Electrode 5... Insertion part 6... Shaft 7... SAW device
8... Ultrasonic transducer 9... Ultrasonic transmission substance 11
．． 12.13...Signal cable 15...Pulser circuit 16...Amplifier 17...A/D converter 18...DSC19...Monitor 2
0... Drive control section Fig. 1 Fig. 5 Fig. 6 l Fig. 7 Fig. 8

Claims (1)

[Claims] 1. An ultrasonic diagnostic device that uses an ultrasonic transducer at the tip of an insertion section into a body cavity and obtains an ultrasonic tomographic image based on echoes of emitted ultrasonic waves, which utilizes surface acoustic waves. A SAW device is provided, and a drive control unit is provided to control the drive of the SAW device, and while the ultrasonic transducer is moved by utilizing the reaction when the SAW device repels surrounding ultrasonic transmitting substances,
An ultrasonic diagnostic device characterized in that it performs ultrasonic scanning by excitation.