JP2001136599A - Ultrasonic-wave generation source for medical treatment and ultrasonic-wave medical treating equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the constitution of an ultrasonic-wave generation source and moreover an ultrasonic-wave medical treatment equipment device in which a focus area is substantially expanded by generating ultrasonic waves by adjacent vibrators in opposite-phase relation and to prevent discharging between the electrodes of the adjacent vibrators. SOLUTION: This ultrasonic-wave generation source 2 is composed of vibrators 101 to 112, and at least one of the vibrators 101 to 112 is arranged so that its polarizing direction is opposite from those of other ultrasonic wave generating elements.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic treatment apparatus for performing treatment by irradiating ultrasonic waves from outside the body.

[0002]

2. Description of the Related Art In recent years, in the field of medical treatment, importance has been placed on improving the quality of life (QOL) of a patient after surgery, and minimally invasive treatment (Minimally Invasive Treatment) has been emphasized.
A treatment called Invasive Treatment (MIT) has attracted attention. One example is the practical use of an extracorporeal shock wave calculus crushing device. This device is
This device irradiates a powerful shock wave from outside the body toward a calculus inside the body, and crushes and treats the calculus without performing any surgical operation. It has drastically changed the method of treating urological calculi. On the other hand, MIT is also one keyword in the field of cancer treatment. In particular, in the case of cancer, many of its treatments rely on surgery, so the functions and appearance of the organs are often greatly impaired, and even if the life is prolonged, a heavy burden remains for the patient Therefore, Q
There is a strong demand for the development of a minimally invasive treatment (apparatus) in consideration of OL.

[0003] In such a trend, hyperthermia therapy has been developed which heats cancer cells and leads to necrosis. this is,
This is a treatment method for selectively killing cancer cells by heating and maintaining an affected part at 42.5 ° C. or higher by utilizing the difference in heat sensitivity between tumor tissue and normal tissue. In particular, for a tumor deep in a living body, a method of using ultrasonic energy with a high penetration depth has been proposed (see Japanese Patent Application Laid-Open No. 61-13955).

[0004] Further, the above-mentioned heating treatment method is further advanced, and a treatment method in which ultrasonic waves generated from a vibrator such as a piezo element are focused on an affected area to heat a tumor portion and cause thermal degeneration and necrosis has been considered. U.S. Pat. No. 5,150,711). In the present treatment method, it is possible to focus the energy of the ultrasonic wave and to heat a localized region having a width of about 1 to 3 mm to 80 ° C. or more in about 1 second or less. On the other hand, there is also a need to heat a wide region over 1 cm at a time, and as disclosed in Japanese Patent Application Laid-Open No. 10-278684, the focal region size is electronically enlarged using phase control. An approach has been proposed. In this method, the focal spot size is increased by driving adjacent ultrasonic wave generating element groups alternately with waveforms having phases different by 180 degrees.

According to the above-mentioned method, it is necessary to alternately apply a driving waveform having a phase shifted by 180 degrees to adjacent vibrators, and at least two types of independent driving circuits whose outputs are out of phase are required as realizing means. Becomes For this reason, there has been a problem that the circuit becomes complicated, resulting in an increase in the size of the device and an increase in price.

In addition, since a therapeutic applicator needs to generate high-output ultrasonic waves from a small area, a plurality of ultrasonic transducers are densely arranged. However, since the phases of the drive waveforms are reversed between the adjacent transducers, a peak voltage of the drive waveform is applied between the electrodes of the adjacent transducers. Therefore, in order to prevent the discharge between the electrodes, it is necessary to take a measure such as providing a sufficient distance between the vibrators so as not to discharge or to seal with an insulating material. Was.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a therapeutic ultrasonic generating source and an ultrasonic medical treatment, in which a focal region is substantially expanded by generating ultrasonic waves from adjacent transducers in opposite phases. An object of the present invention is to simplify the configuration of the apparatus and prevent discharge between electrodes of adjacent vibrators.

[0008]

(1) According to the present invention, there is provided an ultrasonic generator comprising a plurality of ultrasonic generators, wherein at least one of the plurality of ultrasonic generators generates another ultrasonic generator. The polarization direction is opposite to that of the element.

(2) The therapeutic ultrasonic wave generating source of the present invention is arranged such that the plurality of first ultrasonic wave generating elements and the first ultrasonic wave generating elements have polarization directions opposite to each other. And a plurality of second ultrasonic wave generating elements, wherein the first ultrasonic wave generating element and the second ultrasonic wave generating element are arranged adjacent to each other.

(3) The present invention is the therapeutic ultrasonic wave generating source according to (2), wherein the first ultrasonic generating element and the second ultrasonic generating element are electrically parallel. Is connected to the terminal.

(4) The therapeutic ultrasonic wave generating source of the present invention is arranged such that a plurality of first ultrasonic wave generating elements and the first ultrasonic wave generating elements have polarization directions opposite to each other. And a plurality of second ultrasonic wave generating elements, wherein the first ultrasonic wave generating element and the second ultrasonic wave generating element have different surface areas.

(5) The ultrasonic treatment source of the present invention is characterized in that it comprises at least one ultrasonic generation element comprising a first part and a second part whose polarization directions are opposite to each other. .

(6) The present invention is the ultrasonic treatment source according to (5), wherein the first portion and the second portion have different surface areas from each other.

(7) The present invention is the therapeutic ultrasonic wave generating source according to (5), wherein a groove is formed between the first portion and the second portion.

(8) The present invention relates to an ultrasonic treatment apparatus comprising an ultrasonic generating source and a drive circuit for generating driving power for driving the ultrasonic generating source, wherein the ultrasonic generating source comprises: The ultrasonic wave generating device includes a plurality of ultrasonic wave generating elements, and at least one of the plurality of ultrasonic wave generating elements is arranged so that a polarization direction is opposite to that of another ultrasonic wave generating element.

(9) The ultrasonic therapy apparatus according to (8), wherein the plurality of ultrasonic generating elements are connected in parallel to the drive circuit.

(10) The present invention relates to an ultrasonic treatment apparatus comprising an ultrasonic generating source and a drive circuit for generating driving power for driving the ultrasonic generating source, wherein the ultrasonic generating source comprises: A plurality of first ultrasonic wave generating elements, and a plurality of second ultrasonic wave generating elements arranged so that the polarization directions of the first ultrasonic wave generating elements are opposite to each other;
The first ultrasonic wave generating element and the second ultrasonic wave generating element are arranged so as to be adjacent to each other.

(11) The present invention relates to an ultrasonic treatment apparatus comprising an ultrasonic generating source and a driving circuit for generating driving power for driving the ultrasonic generating source, wherein the ultrasonic generating source comprises: A plurality of first ultrasonic wave generating elements, and a plurality of second ultrasonic wave generating elements arranged so that the polarization directions of the first ultrasonic wave generating elements are opposite to each other;
The first ultrasonic wave generating element and the second ultrasonic wave generating element have different surface areas.

(12) The present invention provides an ultrasonic treatment apparatus comprising an ultrasonic generating source and a driving circuit for generating driving power for driving the ultrasonic generating source, wherein the ultrasonic generating source comprises: It is characterized by comprising at least one ultrasonic generating element comprising a first part and a second part whose polarization directions are opposite to each other.

(13) The ultrasonic therapy apparatus according to (12), wherein the first portion and the second portion have different surface areas.

(14) The ultrasonic therapy apparatus according to (12), wherein a groove is formed between the first portion and the second portion.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings. In the ultrasonic treatment, the target is heated by focusing the ultrasonic wave on a target such as a tumor, and the heated state is continued for a predetermined time, so that only the target is selectively necrotic due to a difference in thermal sensitivity. There is a warming treatment system to make the target heat-denaturing necrosis instantly by focusing a very strong ultrasonic wave on the target for a short time, and the present invention can be applied to any of those systems. is there.

FIG. 1 shows the configuration of the ultrasonic therapy apparatus according to the present embodiment. In FIG. 1, a therapeutic ultrasonic applicator 1 has a therapeutic ultrasonic generating source 2 for generating therapeutic ultrasonic waves. The therapeutic ultrasonic wave generation source 2 has a plurality of transducers (ultrasonic wave generation elements) having electrodes formed on both surfaces of, for example, piezoelectric ceramics as piezoelectric bodies.
The plurality of transducers are arranged on a spherical surface such that the ultrasonic waves generated from the respective transducers are focused on the focal point, for example, such that the wavefront of the generated ultrasonic waves is concave. Note that a plurality of transducers may be arranged in a plane, and the drive timing of each transducer may be slightly shifted, that is, the ultrasonic waves generated from each may be focused on the focal point by so-called delay control.

A flexible water bag 4 is provided inside the therapeutic ultrasonic wave generating source 2, and an ultrasonic wave propagation medium, for example, well-degassed water 5 is sealed inside the flexible water bag 4. I have.
At the time of treatment, the applicator 1 is brought into contact with the patient 6 via the water bag 4 and, in this state, a treatment target (target) 7.
The ultrasonic waves for treatment are emitted from the transducers of the ultrasonic wave source 2 for treatment.

A hole is formed at the center of the therapeutic ultrasonic wave generating source 2, and an ultrasonic imaging probe 3 is inserted into this hole. As the ultrasonic probe 3 for imaging, any type can be used, whether a mechanical scan type or an electronic scan type. An ultrasonic imaging device 8 is connected to the imaging ultrasonic probe 3 and reconstructs an ultrasonic image of the inside of the patient 6 based on echo signals collected via the probe 3. This ultrasonic image is displayed on the display unit 9.

A drive circuit 11 for generating electric power necessary for generating ultrasonic waves is connected to the transducer of the therapeutic ultrasonic generator 2 via a matching circuit 10 for performing impedance matching. The drive circuit 11 is connected to an oscillator 12 that oscillates at a frequency that matches the resonance frequency of the vibrator, and amplifies a weak signal of the frequency generated by the oscillator 12 to generate drive power.

As shown in FIG. 2, the ultrasonic wave source 2 includes twelve transducers 101 to 112 having the same surface area. These twelve transducers 101 to 112 are arranged in an annular shape, and half of the six transducers 10 to 112 are arranged.
1, 103, 105, 107, 109 and 111 are the remaining six vibrators 102, 104, 106, 108 and 11
It is arranged upside down so that the polarization direction is opposite to 0,112. That is, the vibrators 101 and 10
3, 105, 107, 109, 111 are arranged such that the polarization directions are aligned in the direction toward the focal point (forward direction), and conversely, the oscillators 102, 104, 106, 108, 1
10, 112 are arranged so that the polarization direction is opposite (the opposite direction) to the direction toward the focal point. in this way,
By arranging the vibrators whose polarization direction is the forward direction and the vibrators whose polarization direction is the forward direction alternately so as to be adjacent to each other, the following effects can be obtained.

These twelve transducers 101 to 112 are:
As shown in FIG. 3, the matching circuit 10 and the driving circuit 11 are connected in parallel. With this connection, drive signals are supplied to the twelve vibrators 101 to 112 in the same phase. Here, the drive signal is usually a sine wave of the mechanical resonance frequency of the vibrator. Vibrator 1 in a certain phase
01, 103, 105, 107, 109, and 111 expand, but the vibrators 102, 104, 106, 108, 110, and 112 arranged with their polarization directions opposite to each other contract. Thereby, even if the twelve transducers 101 to 112 are driven by the in-phase drive signal,
Oscillator 101, 103, 105, 107, 109, 11
And ultrasonic transducers 102, 104, and 10
The phases are opposite to the ultrasonic waves generated from 6,108,110,112. Therefore, as in the case of using two types of drive signals of the opposite phase disclosed in Japanese Patent Application Laid-Open No. 10-278684,
The focus area can be enlarged.

As described above, according to the present embodiment, in order to generate two types of ultrasonic waves with inverted phases, unlike the conventional case, there is no need for at least two types of independent drive circuits whose outputs are in opposite phases. This is possible with one type of drive circuit. Also,
Since the same drive signal may be supplied to the vibrator, the vibrator can be electrically connected in parallel to the drive circuit, thereby simplifying the wiring. Further, since the drive signal is applied to the electrodes of the adjacent oscillators in the same phase, a discharge phenomenon occurs between the electrodes of the adjacent oscillators when the drive signal is applied in the opposite phase between the electrodes as in the related art. Nothing.

In the above description, the number of transducers has been described as being 12. However, the number of transducers is not limited to this. Moreover, in the above description, the transducers are arranged in a line in an annular shape. However, as shown in FIG.
2,301 to 312 may be arranged in two rings of the inside and the outside, and further in the number of rings. In this case, for example, the vibrators having the same polarization direction are arranged so that they do not adjoin each other, that is, the vibrator whose polarization direction is the forward direction and the vibrator whose polarization direction is the forward direction are arranged adjacent to each other. In the example of No. 4, the vibrators 201, 203, 205, 207, 20
9, 211, 302, 304, 306, 308, 31
Numerals 0 and 312 are arranged so that the polarization direction is forward, and the remaining oscillators 202, 204, 206, 208, and
210, 212, 301, 303, 305, 307, 3
09 and 311 are arranged so that the polarization directions are opposite. However, the present invention is not limited to this, and the polarization direction may be aligned in units of two or a predetermined number of transducers adjacent to each other. In addition, various variations are possible in the relationship between the direction of the polarization direction and the arrangement. It is.

In the above description, the surface area of the vibrator is the same irrespective of the polarization direction. However, the surface area of the vibrator having the forward polarization direction is different from that of the vibrator having the reverse polarization direction. You may. Regardless of the polarization direction, when the surface area of the vibrator is the same, the maximum sound pressure point does not appear on the center axis of the focal point, and a sound pressure peak appears in an annular shape around the center of the focal point. In the case of
Similarly to the invention described in Japanese Patent Publication No. 84-84, since a maximum sound pressure point appears also on the central axis of the focal point, it may be effective in treating the focal region uniformly.

When a vibrator is manufactured, a strong electric field is applied to, for example, a piezoelectric ceramic as a piezoelectric material, and polarization is performed. As shown in FIG. 5, a vibrator separated into a first portion 41 whose polarization direction is a forward direction and a second portion 42 whose polarization direction is a reverse direction, that is, a vibrator whose polarization direction is partially reverse. The ultrasonic wave source may be formed by using one or a plurality of transducers. Further, in the case of the vibrator in which the polarization direction is partially reversed in this way, mechanical coupling occurs between the first portion 41 and the second portion 42 which expand and contract in opposite phases, and the vibration efficiency is reduced. Although it may decrease, in order to solve this, a groove 43 may be formed between the first part 41 and the second part 42 as shown in FIG.

In addition, the present invention is not limited to the above-described embodiment, and can be implemented with various modifications.

[0034]

According to the present invention, since at least one of the plurality of ultrasonic wave generating elements is arranged in a direction opposite to the polarization direction with respect to the other ultrasonic wave generating elements, the ultrasonic wave generating elements are driven. Even if the signals are applied in the same phase, two types of ultrasonic waves with inverted phases can be generated to expand the focal region. In other words, it is possible to generate two types of ultrasonic waves with inverted phases without using at least two types of independent driving circuits whose phases are opposite to each other as in the related art. Further, since the same drive signal may be supplied to the vibrator, the vibrator can be connected in parallel, thereby simplifying the wiring. Further, since the drive signal is applied to the electrodes of the adjacent oscillators in the same phase, a discharge phenomenon occurs between the electrodes of the adjacent oscillators when the drive signal is applied in the opposite phase between the electrodes as in the related art. Nothing.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an ultrasonic therapy apparatus according to a preferred embodiment of the present invention.

FIG. 2 is a diagram showing a vibrator array of the ultrasonic generator of FIG. 1;

FIG. 3 is a diagram showing a connection of a vibrator of FIG. 2 to a drive circuit, and a relationship between a polarization direction and vibrator expansion and contraction.

FIG. 4 is a diagram showing another transducer array of the ultrasonic generator of FIG. 1;

FIG. 5 is a sectional view showing another structure of the vibrator of FIG. 2;

FIG. 6 is a sectional view showing another structure of the vibrator of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Applicator, 2 ... Piezoelectric element group, 3 ... Ultrasonic probe for imaging, 4 ... Flexible water bag, 5 ... Propagation medium (water), 6 ... Patient, 7 ... Treatment target, 8 ... Ultrasonic imaging Device 9 display device 10 matching means 11 driving means 12 oscillator.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hideki Ozaku 1385-1 Shimoishigami, Otawara-shi, Tochigi Pref. Toshiba Nasu Factory Co., Ltd. (72) Inventor Yasuhiro Sakamoto 30 Soya, Hadano-shi, Kanagawa Toshiba Ceramics Corporation F term in development laboratory (reference) 4C060 EE17 EE19 JJ11 MM24 MM25 MM26 MM27 4C099 AA01 CA13 GA30 JA13 LA30 5D019 BB02 BB10 BB17 BB20 BB28 FF04 GG01 GG11

Claims (14)

[Claims] 1. An ultrasonic generating source comprising a plurality of ultrasonic generating elements, wherein at least one of the plural ultrasonic generating elements has a polarization direction opposite to that of another ultrasonic generating element. A therapeutic ultrasonic source, wherein the ultrasonic source is disposed in a medical device. 2. A plurality of first ultrasonic wave generating elements and a plurality of second ultrasonic wave generating elements arranged so that the polarization directions of the first ultrasonic wave generating elements are opposite to each other. A therapeutic ultrasonic wave generating source, wherein the first ultrasonic wave generating element and the second ultrasonic wave generating element are arranged so as to be adjacent to each other. 3. The first ultrasonic wave generating element and the second ultrasonic wave generating element.
The ultrasonic generating source for treatment according to claim 2, wherein the ultrasonic generating elements are electrically connected in parallel. 4. A plurality of first ultrasonic wave generating elements and a plurality of second ultrasonic wave generating elements arranged so that the polarization directions of the first ultrasonic wave generating elements are opposite to each other. An ultrasonic source for treatment, wherein the first ultrasonic generator and the second ultrasonic generator have different surface areas. 5. A therapeutic ultrasonic generating source comprising at least one ultrasonic generating element comprising a first part and a second part whose polarization directions are opposite to each other. 6. The ultrasonic treatment source according to claim 5, wherein the first portion and the second portion have different surface areas. 7. The ultrasonic treatment source according to claim 5, wherein a groove is formed between the first portion and the second portion. 8. An ultrasonic treatment apparatus comprising: an ultrasonic generation source; and a driving circuit that generates driving power for driving the ultrasonic generation source, wherein the ultrasonic generation source includes a plurality of ultrasonic generation sources. An ultrasonic treatment apparatus comprising an element, wherein at least one of the plurality of ultrasonic generating elements is arranged so that a polarization direction is opposite to that of another ultrasonic generating element. 9. The ultrasonic therapy apparatus according to claim 8, wherein said plurality of ultrasonic generating elements are connected in parallel to said driving circuit. 10. An ultrasonic treatment apparatus comprising: an ultrasonic generation source; and a drive circuit that generates driving power to drive the ultrasonic generation source, wherein the ultrasonic generation source includes a plurality of first An ultrasonic generating element,
The first ultrasonic wave generating element is composed of a plurality of second ultrasonic wave generating elements arranged so that the polarization directions are opposite to each other. The first ultrasonic wave generating element and the second ultrasonic wave generating element An ultrasonic treatment apparatus, wherein the ultrasonic generating elements are arranged so as to be adjacent to each other. 11. An ultrasonic treatment apparatus comprising: an ultrasonic generation source; and a driving circuit that generates driving power for driving the ultrasonic generation source, wherein the ultrasonic generation source includes a plurality of first An ultrasonic generating element,
The first ultrasonic wave generating element is composed of a plurality of second ultrasonic wave generating elements arranged so that the polarization directions are opposite to each other. The first ultrasonic wave generating element and the second ultrasonic wave generating element An ultrasonic therapy apparatus characterized by having a different surface area from an ultrasonic generating element. 12. An ultrasonic treatment apparatus comprising: an ultrasonic generation source; and a driving circuit that generates driving power for driving the ultrasonic generation source, wherein the ultrasonic generation sources have polarization directions opposite to each other. An ultrasonic treatment apparatus comprising at least one ultrasonic generating element including a first part and a second part oriented in a direction. 13. The ultrasonic treatment apparatus according to claim 12, wherein the first portion and the second portion have different surface areas. 14. The ultrasonic treatment apparatus according to claim 12, wherein a groove is formed between the first part and the second part.