JP3189293B2 - Ultrasound therapy equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic therapy apparatus suitable for treating malignant tumors and calculi.

[0002]

2. Description of the Related Art U.S. Pat. No. 482,173 discloses a conventional example in which an ultrasonic aiming and monitoring function is added to a malignant tumor treatment apparatus using ultrasonic irradiation and a calculus breaking treatment apparatus using shock wave irradiation.
An apparatus in which an ultrasonic probe is incorporated in a transmission aperture of an ultrasonic wave or a shock wave as in No. 0 is conventionally known. With such a device, aiming and
Since both sound waves are used for monitoring, there is a principle advantage that self-alignment is achieved and aiming errors due to refraction in the living body can be suppressed.

[0003]

Although the above technique has enabled focused acoustic wave treatment with a small aiming error, the technique alone is not always sufficient from the viewpoint of confirming aiming. That is, in the case of the current calculus crushing treatment, it is merely determined whether or not the shock wave hits the calculus by observing that the calculus receiving the shock wave moves due to the radiation pressure on the ultrasonic image. . In the case of malignant tumor treatment, the difference in acoustic impedance between the tumor and the surrounding tissue is so small that it is difficult to monitor the movement of the treatment site due to radiation pressure on the ultrasound image. At present, it is almost impossible to confirm that a part has been hit. Furthermore, from the viewpoint of preventing side effects on the surrounding tissue, it is important to detect and suppress cavitation occurring at a site other than the target site of treatment, but it is extremely difficult with only the above technology.

[0004] It is an object of the present invention to solve such a problem and to realize a device capable of accurately confirming that a focused sound wave hits a treatment target site. It is an object of the present invention to enable a focused sonication treatment having a low possibility of causing side effects other than at a target site.

[0005]

In order to solve the above-mentioned problems, according to the present invention, an ultrasonic transducer having a scantable directivity is added to a focused acoustic wave generating transmitter for aiming and monitoring. However, the transmitter / receiver can receive not only the echo generated by the pulsed ultrasonic wave transmitted by itself, but also the echo generated by the focused sound wave transmitted by the transmitter and even harmonics. Constitute. Moreover,
The transmitter transmits a pulse-like or burst-wave-like sound wave, and the wavefront or a flat or curved surface formed by extending the wavefront is synchronized with the time when the wave passes the transmission / reception surface of the transmitter / receiver. The pulse wave is transmitted from the wave device.

[0006]

According to the above arrangement, an ultrasonic image obtained by transmission by the transmitter and reception by the transmitter / receiver is superimposed on a two-dimensional ultrasonic pulse echo image obtained by transmission / reception of the transmitter / receiver itself. A two-dimensional ultrasonic image can be obtained. From this image, the focus position of the sound wave transmitted by the transmitter and the position where cavitation is likely to occur can be confirmed as the position in the ultrasonic pulse echo image.

[0007]

Embodiments of the present invention will be described below. 1, 2, 3 and 4 are a cross-sectional view of an applicator according to one embodiment of the present invention, a circuit configuration diagram of the entire treatment apparatus, a diagram showing transmission waveforms and timings, and a transmission of a focused sound wave. It is a circuit diagram of a resonance characteristic variable part of a wave circuit.

A focused strong acoustic wave transmitting section of the applicator is provided on one side of a light metal substrate 3 which also serves as an acoustic matching material, a ground electrode, and a heat sink, with a resonance frequency of several hundreds of piezoelectric ceramics.
It has a configuration in which a piezoelectric element 1 of Hz to several MHz is bonded. A water bag 4 containing degassed water is attached as an acoustic coupling with the body of the patient to be treated.
The light metal substrate 3 is provided with an inwardly directed direction to enable the focusing of the intense sound waves to the affected area to be treated and the electronic scanning of the focal point in the affected area by a minimum necessary number of electrically independent transducer elements. Are given. The transmission of the strong sound wave is performed by generating a drive signal by the circuit 12 under the control of the transmission control circuit 11, inputting the drive signal to the drive amplifier 13, and driving the piezoelectric element 1 via the variable resonance circuit 14.

An ultrasonic transducer 2 is attached to the applicator so as to enable focusing of a focused intense sound wave on a target to be treated and monitoring during irradiation of the intense sound wave by using an ultrasonic image. Have been. The ultrasonic transducer of this embodiment is of an array type, and is constituted by about 100 piezoelectric elements. A rotating mechanism 5 is provided above the rotating mechanism 5 so that it can rotate. The rotation mechanism 5 has a function of detecting the rotation angle, and the rotation is controlled by the control circuit 10.

In the ultrasonic imaging by the pulse echo method, the transmitter / receiver 2 is driven by the transmission / reception amplifier 15 under the control of the transmission control circuit 16, the ultrasonic pulse is transmitted in the scanning direction, and the reflected echo is again reflected. The signal is received by the wave transmitter / receiver 2, amplified by the wave transmitting / receiving amplifier 15, and is formed by receiving beam scanning and forming an image by the focus circuit 17. The obtained echo image signal is input to the display circuit 18,
A plurality of two-dimensional tomographic images 20 corresponding to different rotation angles are displayed on the display 19 together with the intersection lines 21 of the plurality of tomographic images.

Prior to the continuous irradiation of the intense sound wave, a strong sound wave is transmitted at the timing shown in FIG. 3 so that the focal point of the strong sound wave can be confirmed in the two-dimensional tomographic image. The pulse wave is transmitted by the wave device 1 and the ultrasonic wave transmitter / receiver 2 for imaging. As shown in FIG. 1, when the imaging transducer 2 is configured to protrude from the transmission surface of the strong sound wave transmitter 1, the transmission of the pulsed sound wave by the strong sound wave transmitter 1 is firstly described. The pulsed sound wave is transmitted by the imaging transducer 2 at the timing when the amplitude of the sound pressure waveform at the position of the imaging transducer 2 is maximized as shown in FIG. Is performed as shown in FIG. The reception band of the imaging transducer 2 is assumed to include an even multiple of the strong sound wave frequency, and is capable of receiving harmonics generated by the nonlinear effect of the strong sound wave. If the focusing point of the strong sound wave is fixed and the transducer 2 is scanned and picked up, an image 22 indicating the focused position of the strong sound wave as shown in FIG.
Are superimposed on the pulse echo image 20.

The image 22 indicating the focused position of the strong sound wave by the transmission timing shown in FIG. 3 is displayed at a substantially accurate position on the pulse echo image 20, and furthermore, in the depth direction of the image 22. in order to reduce the spread, the pulsed sound wave transmitting
Of the drive system during continuous transmission of strong acoustic waves
It is desirable to switch so that the Q value becomes smaller than the resonance characteristic . To this end, as shown in FIG. 2, the piezoelectric element 1 is configured to be driven via a variable resonance circuit 14 whose resonance characteristics are controlled by a signal from the strong acoustic wave transmission control circuit 11. As shown in FIG. 4, the variable resonance circuit 14 is connected to a resonance circuit composed of an inductance 30 and a capacitance 31 during continuous transmission of a strong acoustic wave, and is connected to a control circuit such that the resonance circuit is disconnected and directly connected during transmission of a pulsed acoustic wave. Switches 32 and 33 are switched by a signal from 11.

[0013]

As described above, according to the present invention, it is possible to realize a treatment apparatus capable of easily confirming on a picture that a focused intense sound wave is correctly focused on an affected area, and as a result, Highly safe treatment can be achieved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view and a plan view of an applicator according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a circuit configuration of the entire treatment apparatus according to one embodiment of the present invention.

FIG. 3 is a sound pressure waveform diagram at the time of transmitting a pulsed sound wave in one embodiment of the present invention.

FIG. 4 is a circuit diagram of a variable resonance circuit for transmitting a strong acoustic wave in one embodiment of the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 1: strong ultrasonic wave transmitting / receiving element group 2: aiming monitoring ultrasonic wave transmitting / receiving element group 3: light metal substrate 4: water bag for acoustic coupling 5 ... ultrasonic wave transmitting / receiving rotating mechanism 10: main control circuit ,
11: strong sound wave transmission control circuit, 12: strong sound wave transmission element drive signal generation circuit, 13: drive amplifier, 14: variable resonance circuit, 15: ultrasonic wave transmission / reception amplifier, 16: ultrasonic pulse transmission control circuit, 17: Received beam scanning and focus circuit, 18: Display circuit, 19: Display, 20: Two-dimensional tomographic image, 21: Intersecting line of plural tomographic images, 22: Image showing focusing position of strong sound wave , 30 and 31... Inductance and capacitance constituting a resonance circuit for continuous wave transmission, 32
And 33 ... resonance characteristic changeover switch.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-13956 (JP, A) JP-A-2-126848 (JP, A) JP-A-58-188431 (JP, A) JP-A-60-1985 241436 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61B 17/22 A61B 18/00-18/28 A61F 7/00

Claims (4)

(57) [Claims] 1. A sound wave transmitters for transmitting the convergence wave imaging
An ultrasonic transducer for transmitting and receiving an ultrasonic pulse, and the amplitude of the sound wave transmitted from the sound wave transmitter is
An ultrasonic therapy apparatus , wherein the ultrasonic pulse is transmitted from the ultrasonic transducer at a timing at which the ultrasonic pulse becomes maximum at the position of the ultrasonic transducer. 2. The ultrasonic therapy apparatus according to claim 1, wherein said ultrasonic transducer receives an even harmonic generated by said sound wave transmitted from said acoustic wave transmitter. Ultrasound therapy device. 3. The ultrasonic therapy apparatus according to claim 1, wherein an ultrasonic pulse echo image obtained from transmission / reception of an ultrasonic pulse by said ultrasonic transmitter / receiver, transmission of said sound wave by said ultrasonic transmitter, and An ultrasonic therapy apparatus, comprising: display means for superimposing and displaying an ultrasonic image obtained by reception by an ultrasonic transducer. 4. An ultrasonic treatment apparatus according to claim 1, wherein said sound wave transmitter is driven via a variable resonance circuit.