JP2572817B2 - Ultrasound therapy equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an ultrasonic treatment apparatus, and more particularly, to an ultrasonic treatment apparatus for an object to be treated such as a calculus generated in a body by an ultrasonic transducer. The present invention relates to an ultrasonic therapy apparatus that focuses an acoustic shock wave from outside the body and crushes calculus and the like for treatment.

2. Description of the Related Art Conventionally, an ultrasonic therapy apparatus in which a shock wave generated by an ultrasonic wave is generated outside a body, and the ultrasonic wave is focused on a stone formed in the body to destroy the stone is disclosed in Japanese Patent Application Laid-Open No. 60-145131. And Japanese Patent Application Nos. 62-94973 and 6
It is already well known, for example, from 2-67519.

This type of ultrasonic therapy apparatus generally uses an ultrasonic shock wave generator formed by arranging a large number of ultrasonic transducers, each of which is composed of a piezoelectric element, in a mosaic shape in a spherical shape. It is configured to contact the surface of a human body via a filled water bag, focus an ultrasonic shock wave toward a calculus generated in the kidney, bladder, gallbladder, bile duct, and the like, and crush it. The ultrasonic shock wave is generated by applying a pulse-like voltage to the ultrasonic vibrator, and the position of the calculus is confirmed by an ultrasonic observation device or the like.

[Problems to be Solved by the Invention] By the way, in the conventional ultrasonic treatment apparatus of the type described above, since the treatment is performed by focusing the ultrasonic waves, a positive pressure is applied at the focal point of the ultrasonic waves. A negative pressure is generated at the same time. That is, in the living body located at the focal point of the ultrasonic wave,
So-called cavitation (cavity phenomenon) occurs. This cavitation has a risk that, when an attempt is made to generate a large output of ultrasonic waves for treatment at the focal point, the negative pressure increases as the positive pressure increases, which may destroy normal living tissue.

Accordingly, an object of the present invention is to solve the above-described problems in the conventional ultrasonic therapy apparatus, to suppress the increase in negative pressure, to increase only positive pressure, and to obtain a strong ultrasonic wave with a high degree of convergence. An object of the present invention is to provide an ultrasonic therapy apparatus that generates a shock wave, has high safety for a living body, has high conversion efficiency, and can perform efficient and accurate treatment.

[Means and Actions for Solving the Problems] An ultrasonic therapy apparatus according to the present invention is a first ultrasonic transducer in which a plurality of ultrasonic transducers driven at the same drive frequency are arranged on the same radius. A row and a plurality of ultrasonic transducers driven at a driving frequency twice as high as the ultrasonic transducer,
The drive frequency, output, and phase are independently set for each of the second ultrasonic vibrator row and the first and second ultrasonic vibrator rows arranged on concentric circles outside the ultrasonic vibrator row. And a control means for changing, by an ultrasonic shock wave generator constituted by the first and second ultrasonic transducer rows, an ultrasonic wave generated outside the body is focused toward a treatment site in the body. Characterized in that it is treated and has a first annular shape.
And a second ultrasonic vibration which is driven at twice the driving frequency of the first ultrasonic vibrator and is annularly formed on a concentric circle outside the first ultrasonic vibrator. And a control means for independently varying a driving frequency, an output and a phase for each of the first and second ultrasonic transducers, and are constituted by the first and second ultrasonic transducers. Ultrasonic waves generated outside the body are focused by an ultrasonic shock wave generator toward a treatment site inside the body to perform treatment.

[Embodiment] First, before describing an embodiment of the present invention, the overall configuration of an ultrasonic therapy apparatus to which the present invention is applied will be described with reference to FIG. This ultrasonic therapy apparatus includes an observation unit (position detection unit) for detecting a calculus position in a body, a positioning signal generation unit 4, a focus moving unit 7, and a shock wave generation unit 11 for crushing the calculus 1. It is configured.

The observation means emits ultrasonic waves to the human body 10 to detect the position of the calculus 1 in the body, and displays the calculus position based on a detection signal from the device on a screen such as a CRT. It is constituted by the display device 3 and the like.

The positioning signal generating means 4 provides an indication marker or the like at a target point on the screen of the display device 3,
A control signal is output to the focal point moving means 7 so that the focal point of the crushed stone shock wave comes to the position of the indication marker.

The focus moving means 7 moves the water bag 5 and the ultrasonic shock wave generator 6 described below by a numerical control robot or the like in accordance with the positioning signal to focus the crushed stone on the calculus. The shock wave generator 6 includes an ultrasonic vibrator 8 made of a piezoelectric element and a mounting plate 9 formed in a spherical shape.
The ultrasonic shock wave generator 6 and the human body are arranged such that the front surface of the ultrasonic shock wave generator 6 and the human body
A water bag 5 made of a soft resin or the like having liquid injection and pressure control means is disposed between the water bag 10 and the bag 10, and the bag 5 is filled with a shock wave transmitting liquid such as water.

The shock wave generating means 11 is a known ultrasonic pulse voltage generating circuit, and the circuit drives each of the ultrasonic vibrators 8.

 The above is the overall configuration of the ultrasonic therapy apparatus.

FIG. 1 is a front view of a shock wave generator by ultrasonic waves in an ultrasonic therapy apparatus according to one embodiment of the present invention. The overall structure of the ultrasonic therapy apparatus according to the present embodiment is almost the same as that of the ultrasonic therapy apparatus shown in FIG.

In the shock wave generator 12 in this ultrasonic therapy apparatus, a disk-shaped ultrasonic vibrator 8 made of a piezoelectric element is concentrically arranged in front of a mounting plate 9 formed in a spherical shell shape, for example, in four rows in parallel. It is arranged. That is, the innermost ultrasonic transducer row
In 13, there are 24 ultrasonic transducers, 30 in the outer ultrasonic transducer row 14, and 36 in the next outer ultrasonic transducer row 15.
In the outermost ultrasonic transducer row 16, 42 are arranged concentrically in parallel. As shown in FIG. 2, the ultrasonic transducer rows 13, 14, 15, and 16 composed of the ultrasonic transducers 8 have delays for each of the ultrasonic transducer rows 13, 14, 15, and 16. Pulse generators 13b, 14b, 15b, 16b, which are shock wave generating means, are connected via circuits 13a, 14a, 15a, 16a.
In FIG. 2, in order to avoid complexity and simplify the description, each of the transducer rows composed of the above-described ultrasonic transducers is used.
13, 14, 15, 16 are arranged in a one-dimensional manner, but each of the transducer rows 13, 14, 15, 16 has a delay circuit 13a, 14a, 15a, 16a for each transducer row. Can control the phase of the ultrasonic wave generated from the ultrasonic transducer, and the driving frequency and amplitude of the ultrasonic transducer can be controlled by the pulse generators 13b, 14b, 15b, and 16b for each transducer row. It has become. In FIG. 2, the ultrasonic observation device 2 shown in FIG. 7 is omitted.

In the shock wave generator 12 configured as described above,
The driving frequency for driving each of the transducer rows 13 to 16 is as follows:
The relationship is twice as high as the drive frequency of each inner transducer row. That is, the driving frequency of the vibrator row 14 outside the vibrator row 13 is twice the frequency of the row 13, and the driving frequency of the outer vibrator row 15 of the row 14 is about twice the frequency of the row 14. Further, the driving frequency of the vibrator row 16 outside the row 15 is set to be about twice the frequency of the row 15 and driven. Then, considering the time change of the sound pressure of the ultrasonic wave at the focusing point where the ultrasonic waves generated from the ultrasonic transducers of each of the transducer rows 13 to 16 converge at one point, in this case, each transducer Delay circuits 13a to 16a so as to focus on the same point at the maximum point of the sound pressure of the ultrasonic waves generated from columns 13 to 16
Controls the phase.

The state at the focal point where the ultrasonic wave generated from the ultrasonic transducer 8 of each of the vibrator rows 13 to 16 configured and controlled is focused on one point is represented by time on the horizontal axis and sound pressure on the vertical axis. , As shown in FIG. That is, in FIG. 3, a waveform 13c represents a temporal change of the sound pressure of the ultrasonic wave generated from the transducer row 13, a waveform 14c is a transducer row 14, a waveform 15c is a transducer row 15, and a waveform 16c is a transducer. The time change of the sound pressure of the ultrasonic wave generated from the row 16 is shown. Here, the control is performed so that the phases match at the maximum point of the sound pressure. As a result, the temporal change of the sound pressure of the ultrasonic wave synthesized at the focal point is as shown in FIG. That is, as shown in FIG.
In the waveforms 13c to 16c of the ultrasonic waves generated from the transducer rows 13 to 16, the positive pressure and the negative pressure components are almost equal to the sound pressure, but the synthesized ultrasonic wave 17 at the focal point is shown in FIG. As shown in FIG. 7, the negative pressure of the sound pressure with respect to the positive pressure is suppressed.

Therefore, even if a large output is generated at the focal point in order to enhance the treatment efficiency, only the positive pressure increases and the negative pressure does not increase, so that the above-described cavitation (cavitation phenomenon) does not occur, and the normal pressure does not occur. The treatment can be performed safely and efficiently without fear of destroying a living tissue.

Further, the negative pressure of the synthesized ultrasonic wave synthesized by the above-described pulse generators 13b to 16b is applied to each of the transducer rows 13 to
By controlling the sound pressure of the ultrasonic wave generated from the sub-channel 16, it can be further reduced.

Further, the individual ultrasonic transducers constituting each of the transducer rows 13 to 16 can be used without any special treatment, and can be used as they are. Can be

Shock wave generator 12 in the ultrasonic therapy apparatus of the above embodiment
In FIG. 5, a large number of piezoelectric elements 8 are arranged concentrically in four rows on the inner surface of a mounting plate 9 of a spherical shell. Similarly, each of the transducer rows 13 to 16 may be configured to be concentrically arranged on the inner surface of the mounting plate 9A. In this case, the shock wave generator 12A is used as a means for converging the ultrasonic waves generated from each row, by each of the vibrators 8A.
May be controlled to focus the ultrasonic wave at one point, or a focusing acoustic lens may be provided on the front surface.
Further, the pulse generators 13b to 16b, the delay circuits 13a to 16a, and the like are configured in exactly the same manner as in the above embodiment, and there is no change in the operation and effect.

Further, in the shock wave generators 12 and 12A of the above embodiment, the transducer rows 13 to 16 composed of a plurality of ultrasonic transducers 8 are arranged concentrically as shown in FIG. Sixth
As shown in the figure, a plurality of annularly shaped ultrasonic transducers may be arranged concentrically. In this case, it is needless to say that the corresponding pulse generators and delay circuits (both not shown) are connected to the ultrasonic vibrators 18 to 23 independently in the same manner as in the above embodiment. . The operation of the shock wave generator 17 thus configured is exactly the same as that of the shock wave generator 12 shown in FIG. 1, and there is no change in the effect.

Also, the ultrasonic vibrator has a resonance frequency, and is efficiently driven to a limited drive frequency. This is achieved by providing a damping layer or the like to broaden the drive frequency,
Alternatively, the driving frequency may be driven by using a wide-band vibrator such as PVDF (polyvinylidene fluoride) as described in the embodiment of FIG. 1, or the resonance frequency of the vibrator may be reduced by the effect of the present invention. You may make it select and arrange so that it may be obtained.

In addition, the purpose of the present invention is not limited to the removal of calculus, and it is needless to say that the present invention can be applied to all devices that focus and treat an ultrasonic wave on an object.

[Effects of the Invention] As described above, according to the present invention, even if the output is increased to increase the treatment efficiency, the negative pressure is suppressed small, and only the positive pressure can be increased. It is possible to provide an ultrasonic therapy apparatus which can ensure the safety of the living body, has high conversion efficiency, and can efficiently treat the living body without the risk of the normal tissue in the living body being destroyed by the generation.

[Brief description of the drawings]

FIG. 1 is a front view showing a part of a shock wave generator in an ultrasonic therapy apparatus according to an embodiment of the present invention, FIG. 2 is a sectional view of the shock wave generator of FIG. 1, and FIG. FIG. 4 is a waveform diagram showing a waveform of an ultrasonic wave generated from each ultrasonic transducer row of the shock wave generator in FIG. 1; FIG. 4 is a waveform diagram showing a composite wave of the ultrasonic waves in FIG. 3; Waveform diagram, FIG. 5 is a cross-sectional view showing another example of the shock wave generator, FIG. 6 is a front view showing still another example of the shock wave generator, FIG. It is the schematic which shows a structure. 8 Ultrasonic vibrators 12 , 12A , 17 Ultrasonic shock wave generators 13, 14, 15, 16 Ultrasonic vibrator trains 13a, 14a, 15a, 16a Delay circuit (control means) 18- 23 …… Circular ultrasonic transducer (ultrasonic transducer row)

Claims (4)

(57) [Claims] A first ultrasonic transducer row in which a plurality of ultrasonic transducers driven at the same drive frequency are arranged on the same radius; and a drive frequency twice as high as the ultrasonic transducer. A second ultrasonic vibrator row in which a plurality of ultrasonic vibrators to be driven are arranged on concentric circles outside the first ultrasonic vibrator row; and the first and second ultrasonic vibrators. A control means for independently varying a driving frequency, an output and a phase for each of the rows, and generated outside the body by an ultrasonic shock wave generator constituted by the first and second ultrasonic vibrator rows An ultrasonic treatment apparatus characterized in that ultrasonic waves are focused toward a treatment site in a body to perform treatment. 2. The control means according to claim 1, wherein the phase of an ultrasonic wave generated from each of the ultrasonic vibrators constituting the first and second ultrasonic vibrator rows is adjusted at a maximum sound pressure point of a positive pressure at a focusing point. 2. The ultrasonic therapy apparatus according to claim 1, wherein the control is performed so as to be in agreement. 3. The control means controls a sound pressure of an ultrasonic wave generated from the first ultrasonic transducer row at a value smaller than a sound pressure generated from the second ultrasonic transducer row. The ultrasonic therapy apparatus according to claim 1, wherein: 4. A first ultrasonic vibrator formed in an annular shape, and a concentric circle which is driven at a driving frequency twice as high as that of the first ultrasonic vibrator and is outside of the first ultrasonic vibrator. A second ultrasonic vibrator formed in an annular shape above, and control means for independently varying a driving frequency, an output, and a phase for each of the first and second ultrasonic vibrators; An ultrasonic treatment apparatus characterized in that an ultrasonic shock wave generator composed of a first and a second ultrasonic transducer focuses an ultrasonic wave generated outside the body toward a treatment site in the body and performs a medical treatment. .