JP2874994B2 - Ultrasound diagnostic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method of exciting an ultrasonic transducer while rotating and oscillating in a body cavity, and processing an echo from a test object by an external observation device. The present invention relates to an ultrasonic diagnostic apparatus configured to obtain an ultrasonic tomographic image.

[Conventional technology]

Among the ultrasonic probes used in the ultrasonic diagnostic apparatus, those particularly used by being inserted into a body cavity have a configuration as shown in FIG. That is, the insertion section 41 is provided with an ultrasonic probe 42 at the tip, and the ultrasonic probe 42
Flexible shaft extending from 41 to sub-operation unit 43
Ultrasonic scanning while rotating through 45. in this case,
It is a motor 44 provided in the sub-scanning section 43 that applies a rotational force to the flexible shaft 45. For this reason, the flexible shaft 45 that transmits the rotational force cannot transmit the rotational force properly, and causes the rotation of the ultrasonic probe 42 to be uneven.

To solve this problem, Japanese Patent Application Laid-Open No. 62-233150 discloses a method in which a drive motor is mounted in a housing that transmits ultrasonic waves, an ultrasonic vibrator is mounted on a motor shaft of the drive motor in the housing, and ultrasonic vibration is applied. There is disclosed that a child is directly rotated by a drive motor. That is, the motor is provided close to the ultrasonic vibrator.

[Issues to be solved]

However, in the conventional technique, the ultrasonic probe in the distal end portion of the insertion portion is rotated by a drive motor also provided in the distal end portion, so that the diameter of the distal end portion becomes large. Was.

The present invention has been proposed to solve the above-described problem, and does not provide a driving member for an ultrasonic probe such as a motor in the distal end portion of the insertion portion. It is an object of the present invention to provide an ultrasonic diagnostic apparatus capable of obtaining an appropriate ultrasonic tomographic image by rotating a probe.

[Means and actions for solving the problem]

In order to achieve the above object, the present invention provides an ultrasonic diagnostic apparatus in which an ultrasonic transducer is provided at the distal end of a body cavity insertion section and an ultrasonic tomographic image is obtained based on echoes of emitted ultrasonic waves. SAW device using elastic wave and SAW
A drive control unit that controls the driving of the device is provided, and the ultrasonic scanning is performed by exciting the ultrasonic transducer while moving the ultrasonic vibrator using the reaction when the SAW device flips off the surrounding ultrasonic transmitter. This is an ultrasonic diagnostic apparatus.

The ultrasonic wave transmitting substance is brought into contact with the SAW device generating the surface acoustic wave in this way, and the ultrasonic wave transmitting substance generates kinetic energy by using a phenomenon of being scattered in one direction by the SAW jet effect, so that there is no rotation unevenness. The ultrasonic probe can be rotated.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, the characteristics of the SAW device will be described with reference to FIG. A comb-shaped electrode (IDT) 2 is provided on a substrate (LiNbO ₃ ) 1. FIG. 2 is a plan view of the comb-shaped electrode 2 disposed on the substrate 1. FIG. When the electrode 2 is excited at a voltage of a frequency of about 50 MHz and a cycle of about 100 Hz as shown by an arrow X, the substrate fluctuates in the illustrated wave shape. Then, the ultrasonic transmitter in contact with the substrate 1 becomes SA
It scatters in one direction (arrow Y) due to the W effect. Small circle 3
Shows the particles of the ultrasonic transmitter that have scattered. If scattered, the SAW device will react,
This scattered force is used as kinetic energy.

FIG. 3 shows an embodiment in which the first embodiment of the SAW device described above is applied to an ultrasonic probe 4. A flexible shaft 6 is provided in the insertion portion 5 of the ultrasonic probe 4, and a SAW device 7 is provided on the shaft 6 so as to be movable. Specifically, the shaft 6 passes through the inside of the SAW device 7, and the SAW device 7 is configured to be able to rotate in the outer circumferential direction of the shaft 6 and to move in the extending direction of the shaft 6. Further, near the probe base on the shaft 6, a SAW device 7 is connected (not shown),
Ultrasonic transducer 8 that moves in conjunction with the movement of AW device 7
Is provided. Further, the periphery of the shaft 6, the SAW device 7, and the ultrasonic vibrator 8 is filled with an ultrasonic transmitting material 9 having good ultrasonic permeability such as water. In addition, a linear encoder 10 is provided near the ultrasonic vibrator 8 so as to detect a scanning position of the ultrasonic vibrator 8. And SA
A signal cable 11 is connected to the W device 7 to transmit a signal to the electrode, and a signal cable 12 is connected to the ultrasonic transducer 8 to transmit an electric signal. A signal cable 13 is connected to 10 so as to detect a signal. Each of the above signal cables is guided to an observation device 14 provided outside.

The observation device 14 is provided with a pulsar circuit 15 and is connected so as to emit ultrasonic waves by supplying a signal to the ultrasonic vibrator 8. The echo from the subject after emitting the ultrasonic waves is converted into an electrical signal and then converted to an amplifier.
(Including detection), digitized by A / D converter 17, and then converted to digital scan converter (DSC) 18
, And is displayed on the monitor 19 in the B mode. On the other hand, the signal cable 11 connected to the SAW device 7 is connected to the drive control unit 20 together with the signal cable 12 for transmitting the position detection signal of the ultrasonic transducer 8,
The 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 unit 20. A signal cable 11 is connected to both ends of the electrode 2 of the SAW device 7. Each of the signal cables 11 is connected to a changeover switch 21 of a drive control unit 20, one of the switches 21 is connected to a power amplifier 22, and the power amplifier 22 is connected to a variable gain amplifier 23. A signal source 24 is connected to the variable gain amplifier 23. On the other hand, the signal cable 13 connected to the linear encoder 10
, And detects a 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 to the F / V converter 26 as a scan rate control signal of the ultrasonic transducer. 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 and a differential amplifier 28, The compared output changes the amplification of the variable gain amplifier 23. Then, the voltage amplitude for exciting the SAW device 7 is controlled so that the scan rate of the ultrasonic transducer is made constant. The notch filter 31 is a SAW
It is provided selectively so that the electric signal for exciting the device 7 does not saturate the amplifier 16.

To explain the operation of the present embodiment configured as described above, the SAW device 7 is excited by supplying a signal from the signal source 24 to the electrode 2, and generates a surface acoustic wave. Then, the ultrasonic transmitter around the SAW device 7 is turned into particles and is skipped. At this time, a kinetic energy is generated in the SAW device 7 due to the repelled reaction. On the other hand, since the SAW device 7 is provided on the shaft 9 and can move in the outer circumferential direction of the shaft 9, the ultrasonic vibrator 8 connected by moving by the reaction also moves in the outer circumferential direction of the shaft 9. You will be exercising. Therefore, if a drive signal is supplied to the ultrasonic vibrator 8, ultrasonic scanning can be performed while moving. In this case, the scanning speed of the ultrasonic vibrator 8 is controlled by converting a signal (A phase) for detecting the position of the ultrasonic vibrator 8 into a speed signal by the F / V converter 26. This speed signal is compared with a reference power supply 27 that determines the scan rate of the ultrasonic transducer 8, and the compared signal controls the gain of the variable gain amplifier 23.
Thus, the amplitude of the excitation voltage applied to the SAW device 7 changes so that the scan rate of the ultrasonic transducer 8 becomes constant. Note that the speed signal and the reference power supply 30
The amplitude value of the signal source 24 may be varied according to the difference signal from the signal, 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. It goes without saying that the rate 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 extending direction of the shaft. For this purpose, the origin signal of the linear encoder 10 (Z phase)
To the electrode 2 connected to the power amplifier 22 by a switch
The driving direction is changed via 21 to supply a signal, the direction in which the surface acoustic wave is generated is changed to change the direction in which the ultrasonic transmitter 9 is scattered, and the direction of movement of the SAW device moving on the axis 6 is changed. Do it by changing.

As described above, in the present embodiment, the ultrasonic vibrator 8 can be directly driven by the kinetic energy of the extremely small SAW device 7 provided at the distal end, so that the ultrasonic vibrator 8 can be rotated uniformly without increasing the distal end. Ultrasonic scanning can be realized while rotating without rotation.

FIG. 5 shows a second embodiment of the present invention.
The same reference numerals are given to portions corresponding to the embodiment. In the present embodiment, the ultrasonic transducer 8 and the SAW device 7 are joined on the back surface. Therefore, the movement of the SAW device 7 allows the ultrasonic transducer 8 to move integrally, so that linear scanning can be performed without the intermediary of the connecting member. Other configurations are almost the same as in the first embodiment.

With this configuration, in addition to having the same effect as described above, the length of the distal end portion of the ultrasonic probe can be shortened, and the pain of the subject can be reduced, and the operability can be improved.

FIG. 6 shows a third embodiment of the present invention, in which the ultrasonic vibrator 8 is rotated via a rotary shaft 29, and one end of the ultrasonic vibrator 8 near the insertion portion 5 is provided with a SAW. Device 7 is provided. Other configurations are almost the same as in the first embodiment.

With this configuration, the same effect as that of the first embodiment can be obtained, and the SAW provided in the direction
The reaction caused by the device 7 flipping off the ultrasonic transmitter 9 causes the ultrasonic vibrator 8 to rotate in the direction of the arrow, thereby causing a radial rotation.

FIG. 7 shows a fourth embodiment of the present invention.
The SAW device 7 is provided on the ultrasonic vibrator 8 as in the embodiment, but is arranged symmetrically with respect to the rotation axis 29. Other configurations are the same as in the first embodiment.

With such a configuration, the sector scan can be performed by selectively driving the SAW device 7 in addition to having the same effect as the first embodiment.

FIG. 8 shows a fifth embodiment of the present invention. In this embodiment, the SAW device 7 and the ultrasonic vibrator 8 are arranged on the shaft 6 in the axial direction similarly to the first embodiment. The probe is provided at a position near the base of the probe so as to oppose the shaft 6 therebetween. Other configurations are almost the same as those of the first embodiment.

With this configuration, in addition to having the same effect as the first embodiment, the radial scan and the linear scan by the ultrasonic transducer 8 can be performed simultaneously, and a three-dimensional ultrasonic image can be displayed. Can be.

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

With this configuration, the ultrasonic transmitter 9 is flipped in the direction A by driving the SAW device 7, and the ultrasonic probe is rotated in the direction C by the reaction. The ultrasonic wave is transmitted from the ultrasonic vibrator 7 through the concave curved lens 30 and radiated in the B direction, and the echo is received on this surface. Other configurations are the same as 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 ultrasonic scanning, so that the configuration is simplified and the diameter of the insertion portion is reduced. The diameter can be reduced.

〔The invention's effect〕

As described above, according to the present invention, since the rotation of the ultrasonic probe for performing the ultrasonic scanning can be performed by the SAW device provided near the ultrasonic probe, the present invention is compared with a configuration in which the ultrasonic probe is rotated via the coil shaft. In addition, proper ultrasonic scanning can be performed by eliminating rotation unevenness. Moreover, since only an extremely small element is used, the diameter of the insertion portion is not increased.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining the operation of a 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, FIG. Fig. 5 is a sectional view of the same part, Fig. 5 is a sectional view of the second embodiment of the present invention, Fig. 6 is a sectional view of the third embodiment, and Fig. 7 is a sectional view of the fourth embodiment. FIG. 8 is a cross-sectional view according to a fifth embodiment, FIG. 9 is a cross-sectional view according to a sixth embodiment, and FIG. 10 is an external view of an ultrasonic probe according to a conventional example. DESCRIPTION OF SYMBOLS 1 ... Board, 2 ... Electrode 5 ... Insert part, 6 ... Shaft 7 ... SAW device, 8 ... Ultrasonic vibrator 9 ... Ultrasonic transmitting substance, 11, 12, 13 ... Signal cable 15 …… Pulsa circuit, 16… Amplifier 17… A / D converter, 18… DSC 19… Monitor, 20… Drive control unit

Claims (1)

(57) [Claims] An ultrasonic transducer is provided at the distal end of an insertion portion in a body cavity,
In an ultrasonic diagnostic apparatus configured to obtain an ultrasonic tomographic image based on an echo of a radiated ultrasonic wave, a SAW device using a surface acoustic wave and a drive control unit that controls driving of the SAW device are provided. An ultrasonic diagnostic apparatus characterized in that ultrasonic scanning is performed by exciting the ultrasonic vibrator while moving the ultrasonic vibrator by utilizing the reaction when the device flips the surrounding ultrasonic transmitting substance.