JP2000166940A - Ultrasonic treatment instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a focus area where a sound pressure maximal value exists in the center of a focus and the periphery of the focus and to make the size of the focus area variable in an ultrasonic wave treatment device by which ultrasonic wave generated from plural vibrators is focused on a target such as calculus or a cancer cell to treat it. SOLUTION: This instrument is provided with the plural vibrators 1101-1112 generating plural kinds of ultrasonic wave to be focused on the focus by being impressed plural driving signals, plural driving units 110, 111, 112 and 113 generating the respective driving signals by varying a phase and amplitude and a control circuit 114 individually controlling the driving units in order to set the phase and amplitude in each driving signal. Thus, the plural kinds of ultrasonic wave being different in phase and amplitude are simultaneously generated so that the focus area where the sound pressure maximal value exists in the center and the periphery of the focus.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention focuses ultrasonic waves generated from a plurality of transducers on a target such as a calculus or a cancer cell, and crushes or thermally denatures (cauterizes) the target with the focused energy for treatment. The present invention relates to an ultrasonic irradiation device.

[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 patients 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 device in consideration of OL.

In such a flow, cancer cells are heated,
Hyperthermia therapy has been developed that leads to necrosis. This takes advantage of the difference in heat sensitivity between tumor tissue and normal tissue,
This is a treatment method in which a target is heated to 42.5 ° C. and the temperature is maintained for a certain period of time to selectively kill cancer cells. In particular, for a tumor deep in a living body, a method of using ultrasonic energy having a high penetration depth has been considered (see Japanese Patent Application Laid-Open No. 61-13955). In addition, a treatment method in which the above-mentioned heating treatment method is further advanced, and an ultrasonic wave generated by, for example, a piezoelectric ceramic vibrator is focused on the target and the target is heated to cause thermal degenerative necrosis has been considered. No. 5,150,711). In the present treatment method, it is possible to focus the energy of the ultrasonic wave and heat a localized area 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 a need to heat a wide area over several mm at a time.
As disclosed in Japanese Patent No. 8930, there has been proposed a method of electronically enlarging the size of a focal region using phase control. In this method, the focus area is expanded by separately driving the adjacent transducers with two types of drive signals whose phases are inverted, and the focus magnification is changed by adjusting the phase difference. ing. Further, as disclosed in Japanese Patent No. 2,036,277, there is a control method for maintaining the pressure on the central axis of the ultrasonic generator at zero.

According to the above method, the size of the focal region can be changed by controlling the phase difference between the drive signals to the adjacent transducers. However, the variable phase for finely adjusting the phase difference is controlled. A circuit such as a shifter has a complicated hardware configuration. On the other hand, when using only a phase inversion circuit that can be achieved with simpler hardware,
It is impossible to electronically control the magnification of the focal region, and the normal size when driving the vibrator all at once with zero phase difference,
Only two types, that is, an enlarged size when driving with a time difference through phase inversion, can be selected.

In order to obtain a therapeutic effect in a short time, it is effective to increase the total energy in the focal region. In order to realize this, it is sufficient to apply a large energy to the ultrasonic vibrator, that is, drive the ultrasonic vibrator at a high voltage.

However, when the input energy is increased by the focusing method described above, the peak sound pressure in the focal region becomes extremely large. M. Report of Ioritani et al. (Renal tissue damage i)
ndused by focused shock w
aves. Proc. 18th Inter. symp
o. Shock waves and shock
tubes, 1990), it is known that the higher the peak sound pressure, the stronger the biological damage appears. Therefore,
If the peak sound pressure is too high, side effects may increase. For this reason, a method has been conceived in which the focal region is enlarged, the energy is dispersed in a wide range, and the wide range is treated at a time to reduce the total treatment time. As a method of expanding such a focal region, for example, Japanese Patent Application Laid-Open
No. 078930 proposes a method of alternately inverting the drive phase between transducers, that is, shifting the drive phase by 180 °.

According to the above-described method of alternately inverting the drive phase between the transducers, the sound field distribution as shown in FIG. 28, that is, the sound pressure peak is dispersed annularly around the focal point center.
A donut-shaped sound field distribution in which the sound pressure at the center of the focal point is significantly lower than the surrounding peak sound pressure. Therefore,
Even if heat conduction is taken into consideration, the actual ablation region has a donut shape, and there is a problem that the target in the focal region cannot be cauterized substantially uniformly.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ultrasonic treatment apparatus which focuses ultrasonic waves generated by a plurality of transducers on a target such as a calculus or a cancer cell and treats the target. Is to form a focal region existing at the center of the focal point and around the focal point, and to make the size of the focal region variable.

[0010]

(1) An ultrasonic therapy apparatus according to the present invention comprises: a plurality of transducers for generating a plurality of ultrasonic waves focused on a focus by applying a plurality of drive signals; A plurality of drive units that generate drive signals with variable phases and amplitudes, and a control circuit that individually controls the drive units in order to set the phases and amplitudes of the drive signals. Features.

(2) The ultrasonic therapy apparatus according to the present invention comprises a plurality of first transducers for generating a plurality of first ultrasound waves which are focused on a focus by applying a plurality of first drive signals;
The first drive signal is applied by applying a plurality of second drive signals.
A plurality of second vibrators for generating a plurality of second ultrasonic waves focused on the same focal point as the ultrasonic waves; a first drive unit for generating the first drive signal by changing the phase and amplitude;
A second drive unit that generates a drive signal with variable phase and amplitude; and a first drive unit and a second drive unit that differ in phase and amplitude between the first drive signal and the second drive signal. And a control circuit for controlling the two drive units.

(3) In the ultrasonic therapy apparatus according to the present invention, the first drive signal is applied to generate a plurality of first transducers for generating the first ultrasound focused on the focal point and the second drive signal. The second ultrasonic wave, which is focused on the same focal point as the first ultrasonic wave by being applied, generates the second ultrasonic wave.
A plurality of second vibrators arranged so as to be adjacent to the vibrator, a first drive unit for generating the first drive signal, and a second drive unit for generating the first drive signal in an opposite phase to the first drive signal; A second driving unit for generating a driving signal.

(3) In the ultrasonic therapy apparatus according to the present invention, a plurality of first transducers for generating a first ultrasonic wave focused on a focus by applying a first drive signal and a second drive signal are provided. When applied, a plurality of first transducers that generate a second ultrasonic wave focused on the same focal point as the first ultrasonic wave, a drive unit that generates a drive signal, and the first drive signal Means for differentiating between the phase of the first drive signal and the phase of the second drive signal, and the amplitude of the first drive signal and the second drive signal. And a means for differentiating the amplitude of the signal.

(4) An ultrasonic therapy apparatus according to the present invention comprises: a drive unit for generating a high-frequency drive signal; and a plurality of first transducers for generating a first ultrasonic wave focused on a focus by applying the drive signal. Generating a second ultrasonic wave focused on the same focal point as the first ultrasonic wave by applying the drive signal, wherein a plurality of second ultrasonic waves are provided at a position closer to the focal point than the first transducer. And a vibrator.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention will be described below in detail with reference to the drawings.

(First Embodiment) FIG. 1 shows a configuration of an ultrasonic irradiation apparatus according to a first embodiment of the present invention.
In FIG. 1, a treatment applicator 101 includes a treatment ultrasonic generation source 102 that generates treatment ultrasonic waves, and a cross section including a focal region that is inserted into a substantially central hole of the treatment ultrasonic generation source 102. An ultrasonic probe 103 for imaging for imaging as a tomographic image, an ultrasonic propagation medium,
For example, it has a flexible water bag 104 in which well degassed water 105 is sealed. An ultrasonic imaging device 108 is connected to the ultrasonic probe 103 for imaging, scans a cross section including a focal region by ultrasonic waves through the ultrasonic probe 103, and performs the scanning based on an echo signal obtained thereby. A tomographic image (B-mode image) of the cross section is generated and displayed on the display device 109 in real time.

As shown in FIG. 2, the treatment ultrasonic generating source 102 has an even number of electrically separated transducers, here, twelve transducers 1101 to 1112. That is, the therapeutic ultrasound source 102 has 12 channels. Each of the twelve vibrators 1101 to 1112 is formed of one piezoelectric ceramic piece formed in a substantially fan shape, or a plurality of piezoelectric ceramic pieces electrically connected by a common electrode are arranged in a substantially fan shape. Such a vibrator 1101
1112 are arranged in a substantially annular shape, and have a substantially spherical shell shape as a whole. The ultrasonic waves generated from each transducer are
It focuses on a focal point 116 which is geometrically determined according to the curvature of the spherical shell, and treats the target 17.

The twelve transducers 1101 to 1112 include:
12 (12 channels) impedance matching circuits 1
10 are connected one-to-one. The inputs of the twelve impedance matching circuits 110 also have twelve (12
The outputs of the amplifiers (channels) 111 are connected one-to-one. Further, the inputs of the twelve amplifiers 111 have 1
Two (12 channels) phase non-inverting / inverting circuits 112
Are connected one-to-one. To the inputs of the twelve phase non-inverting / inverting circuits 112, a waveform generating circuit 113 for generating a high-frequency (frequency f0) waveform signal is commonly connected. The matching circuit 110 and the amplifier 111
And the phase non-inverting / inverting circuit 112 constitute a drive unit.

Each of the phase non-inverting / inverting circuits 112 selectively gives a phase shift amount of approximately 0 ° or approximately 180 ° to the waveform signal from the waveform generating circuit 113 under the control of the control circuit 114. In other words, it is possible to select either to output the waveform signal as it is without inverting the phase or to output the waveform signal after inverting the phase instead.

FIGS. 3 (a), 3 (b), 4 (a), and 4 (b) show four specific examples of the configuration of the phase non-inverting / inverting circuit 112 having such a function. Is shown. FIG.
In (a), an inverted output is obtained from the collector c of the transistor TR and a non-inverted output is obtained from the emitter e, and either output is switched by the selector SEL. In FIG. 3B, the non-inverting input (+) and the inverting input (-) of a general operational amplifier OP are switched by a selector SEL to control the output phase.
FIG. 4A shows the use of the in-phase and inverted phase outputs of the transformer TRAN, and FIG. 4B shows the non-inverted and inverted states of the digital signal using an inverter IN and a low-pass filter. A phase sine wave is obtained, and one of them is switched by the selector SEL.
In this case, the input signal is a square wave clock signal.
In any method, the phase of the waveform signal is controlled by providing the phase inverting circuit 112 on the input side of the amplifier 111, and as a result, the phase of the drive signal applied to the ultrasonic wave source 12 is controlled. It has become. On the other hand, a transformer may be inserted on the output side of the amplifier 111 to switch between the in-phase output and the inverted phase output. Further, the transformer on the output side of the amplifier 111 may be configured to also serve as the impedance matching circuit 110.
The method of obtaining an inverted output by inserting a transformer on the output side of the amplifier 111 is effective when there is only one amplifier 111. Alternatively, both the non-inverted output impedance matching circuit and the inverted output impedance matching circuit may be prepared, and these may be switched for use.
As the above-mentioned selector SEL, a general manual switch, relay, analog switch, three-state buffer (digital IC), or the like can be used.

As the waveform generating circuit 113, a normal analog oscillation circuit or a PLL circuit may be used, or a waveform is synthesized digitally, and a sine wave is obtained using a DA converter and a low-pass filter. You may do so.
Also, the waveform generating circuit 113 and the phase inverting circuit 112 are digitally configured, and the output of the phase inverting circuit 112 is
It is also possible to obtain a sine wave using an A-converter or a low-pass filter.

Here, returning to FIG. The amplifier 111 amplifies the non-phase-inverted waveform signal or the phase-inverted waveform signal from the phase non-inverting / inverting circuit 112, and drives the corresponding vibrator or the phase-inverted driving signal, respectively. Generate a signal. The amplification factor of each of the amplifiers 111 can be individually adjusted according to the control of the control circuit 114.

The operator can mainly select the size of the focal region by operating the input device 111 such as a keyboard and a mouse.

Next, the operation of the present embodiment will be described on the assumption that a therapeutic ultrasonic wave is focused to heat and treat the cancer cells 107 in the patient 106. First, when unifying the output phases of the twelve phase non-inverting / inverting circuits 112,
That is, when non-inverted waveform signals or phase-inverted waveform signals are output from all 12 phase non-inverting / inverting circuits 112, all drive signals from the 12 amplifiers 111 are output with the same phase. You. As a result, the twelve vibrators 1101 to 1112 are simultaneously driven, thereby forming the smallest focal region.

When the output phase of the phase non-inverting / inverting circuit 112 is not unified with respect to the simultaneous driving, that is, a non-inverted waveform signal is output from some of the phase non-inverting / inverting circuits 112 and the remaining phase is output. When the non-inverting / inverting circuit 112 outputs a waveform signal whose phase has been inverted, 1
Some of the two vibrators 1101 to 1112 are driven by non-inverted drive signals, and the remaining vibrators are driven by phase-inverted drive signals.

In the present embodiment, which vibrator is driven by the non-inverted drive signal and which vibrator is driven by the phase-inverted drive signal, that is, the vibrator driven by the non-inverted drive signal and the phase inverted The size of the focal region can be variously changed by changing variously the arrangement pattern with the vibrator driven by the applied drive signal by the control circuit 114. Hereinafter, examples of some specific arrangement patterns will be described.

(First Pattern) In the first pattern, FIG.
As shown in (a), a non-inverted drive signal and a phase-inverted drive signal (opposite-phase drive signal) are alternately supplied to the twelve vibrators 101 to 112 along the circumferential direction. I do. That is, the vibrator 11 driven by the non-inverted drive signal
01, 1103, 1105, 1107, 1109, 11
11 and the vibrator 1 driven by the phase-inverted drive signal
102, 1104, 1106, 1108, 1110, 1
112 are alternately arranged along the circumferential direction. According to such a first pattern, for example, the ultrasonic source 102 having an opening diameter of 60 mm, a center hole diameter of 25 mm, and a focal length of 70 mm is used.
Assuming that the diameter and the maximum intensity of the focal region in the case of simultaneous driving, that is, the energy concentration region, are 1, FIG.
In the driving method based on the first pattern shown in (a), the peak intensity is reduced to about 10%, and the diameter of the focal region is expanded about 2.4 times. In the non-inverted drive signal and the phase-inverted drive signal, n is a real number excluding 1 and 1: n (n ≠ 1)
By giving the amplitude ratio, a sound field distribution having a sound pressure peak at the center can be obtained.

(Second Pattern) In the second pattern, FIG.
As shown in (b), twelve vibrators 1101 to 111
2, two non-inverted drive signals and two phase-inverted drive signals are alternately supplied along the circumferential direction.
That is, two vibrators (1101 and 1102, 1105 and 1106, 1109 and 1110) adjacent in the circumferential direction
, A non-inverted drive signal is supplied, and similarly, two phase-adjacent oscillators (1103 and 1104, 1107 and 1108, 1111 and 1112) are supplied with phase-inverted drive signals. Thus, two transducers driven by the non-inverted drive signal and two transducers driven by the phase-inverted drive signal are alternately arranged in the circumferential direction. Furthermore, by giving an amplitude ratio of 1: n (n ≠ 1) to the non-inverted drive signal and the phase-inverted drive signal, where n is a real number excluding 1, for example, as shown in FIG. A sound field distribution having a sound pressure peak can be obtained. According to such a second pattern, for example, assuming that the ultrasonic source 2 has an opening diameter of 60 mm, a center hole diameter of 25 mm, and a focal length of 70 mm, the focal region in the simultaneous driving, that is, the diameter and the maximum intensity of the energy concentration region 1
Then, the peak intensity is reduced to about 24%, and the diameter of the focal region is enlarged about 1.6 times.

(Third Pattern) In the third pattern, as shown in FIG. 5C, a vibrator driven by a non-inverted drive signal and a vibrator driven by a phase-inverted drive signal are used. Are driven so as to be alternately arranged three by three along the circumferential direction, for example, the opening diameter is 60 mm, and the center hole diameter is 25.
Assuming that the ultrasonic source 2 has a focal length of 70 mm and a focal length of 70 mm, and the diameter and the maximum intensity of the focal region in the simultaneous driving, that is, the energy concentration region, are 1, the peak intensity is reduced to about 33%, The diameter is enlarged about 1.2 times. A sound field having a sound pressure peak at the center by giving an amplitude ratio of 1: n (n ≠ 1) to the non-inverted drive signal and the phase-inverted drive signal, where n is a real number excluding 1 A distribution can be obtained.

(Fourth Pattern) In a fourth pattern, there are six vibrators driven by a non-inverted drive signal and six vibrators driven by a phase-inverted drive signal along the circumferential direction. Half lined up. That is, half of the six vibrators 1101 to 1101
1106 is driven by the non-inverting drive signal, and the other half 6
The vibrators 1107 to 1112 are driven by the phase-inverted drive signal.

(Other Irregular Patterns) In addition to the above-described first to third patterns, the source 102 is driven in an irregular pattern as shown in FIGS. 5D and 5E. It may be. In the pattern of FIG. 5D, one vibrator driven by a non-inverted drive signal and two adjacent vibrators driven by a phase-inverted drive signal are connected along the circumferential direction. And drive them alternately. FIG.
In the pattern of (e), the source 102 has an additional 12 oscillators arranged in an annular shape outside (or inside) an array in which 12 oscillators are arranged in an annular shape. The inner ring and the outer ring may be driven in the first pattern so that the oscillator driven by the non-inverted drive signal in the radial direction and the oscillator driven by the phase-inverted drive signal are arranged side by side. Good.

By switching the arrangement pattern of the vibrator driven by the non-inverted drive signal and the vibrator driven by the phase-inverted drive signal under the control of the control circuit 114, the size of the focal region and the The peak intensity can be varied.

In addition to the fact that the size and peak intensity of the focus area can be changed, as shown in FIG. 7, markers (focus markers) A, B, and F3 indicating three types of focus areas having different sizes. C is prepared, and the actually selected focus markers are distinguished by solid lines, and the remaining focus markers that are not selected are distinguished by dotted lines and displayed together with the tomographic image on the display screen of the display device 109. In FIG. 7, the unselected focus markers are displayed by dotted lines, but need not be displayed. Further, in FIG. 7, the selected focus marker is displayed by a solid line, and the non-selected focus marker is displayed by a dotted line. However, both markers may be distinguished by colors or may be distinguished by changing a shading form.

Also, with or instead of the focal area,
A predicted heat denaturation region marker, a pressure half width, or a first nodal pressure may be displayed. Further, when the operator selects the size of the focal region, here, A,
Although input is performed from the console 115 as in B and C, the input is not limited to input from the keyboard, but can be switched by a manual switch,
You may make it select by a foot switch. For example, if a foot switch is used, the size of the focal area is changed each time the switch is depressed, and the selection can be made by double-clicking the foot switch or lengthening the time during which the switch is depressed. If a mouse is used, the user can select a marker corresponding to the size of the desired focal area on the screen, for example, by placing the mouse pointer on the marker C and clicking the mouse, or by using a light pen or trackball instead of the mouse. May be. When the selection is completed, the size change may be clearly indicated by a solid line or a color line, and the unselected size may be changed to a dotted line, a light color, or the like and displayed instead.

Further, as shown in FIG. 7, when the operator designates a target, that is, a portion to be treated 131 such as a cancer cell, the control circuit 114 performs a focus scan (focus movement sequence), the size of the focus area, The entire treatment area 132 expected in consideration of the irradiation time and the irradiation intensity is displayed. In FIG. 7, all the set treatment areas 132 are displayed in a stripe pattern. The operator operates the treatment target area 131 and the entire treatment area 1.
32 are compared, and if it is determined that the treatment area 132 is the necessary and sufficient treatment area 132, the treatment start button is pressed. If there is an excess or deficiency in the designated area 131 that is not recognized in the entire treatment area 132, the operator can change the entire treatment area 132 using a mouse, a light pen, or a trackball. In response to this operation, the control circuit 114 changes the entire treatment area 132 so as to be closest to the requested one, and displays the new treatment area 32 as a new total treatment area 32.

That is, the control circuit 114 changes the form of the focus scan, or changes the size of the focus area for each focus position, so as to approximate the required shape of the entire treatment area 132. . The above operator and control circuit 11
4 is repeated, and the optimal total treatment area 132 is
Is set and the treatment is started. The above operation can be manually specified by the operator. That is,
The operator superimposes the focal region marker corresponding to the size of the heat denaturation region on the treated portion 131 as if by a puzzle. The size of the marker is irradiation intensity, irradiation time,
Since the focus area can be changed by changing the size of the focus area, the control circuit 11 is controlled so as to be in the designated heat denaturation area.
4 may determine the irradiation intensity, the irradiation time, and the size of the focal region. In addition, the entire treatment area 1 determined by the control circuit 114
Even when the operator corrects 32, addition or deletion of the treatment area by the focus area marker can be manually designated. As described above, the entire treatment area 13
2. When the irradiation intensity, irradiation time, focus area size, and focus scanning method are determined, the necessary treatment time is calculated and displayed. In FIG. 7, the size of the focal region (focal size), the irradiation intensity, the irradiation time, and the remaining treatment time are simultaneously displayed on the upper right of the tomographic image screen. If the focus scan is performed and the treatment is in progress, the treatment time display is updated and decreases.

Contrary to the above, the operator sets the treatment time as the highest priority, and calculates and displays the appropriate irradiation intensity, irradiation time, size of the focal region, and total treatment region 132. Is also good. In addition, the operator may set any items to be set as the highest priority.
May be calculated.

Note that the present embodiment is not limited to the above-described twelve vibrators, but may be, for example, 100 vibrators. In addition, the number of rings is not limited to 1 or 2, and can be theoretically increased to infinity. Also in this case, by changing the electrical settings, it is possible to operate as a one-ring-shaped generation source or as an annular array ring,
5A, 5B, and 5C can be driven. Of course, even when the number of rings is two or more, the operation is performed in such a manner that the entire ultrasonic wave generating source 2 is divided into an even number. Further, the present method may be applied using not only the spherical shell type but also a two-dimensional array vibrator of a flat plate type. Further, the method of enlarging the size of the focal region can be applied to an arbitrary focal position electronically formed by the phased array.

By adjusting the amplitude ratio between the non-inverted drive signal and the phase-inverted drive signal to 1: n,
That is, by making the amplitude of the non-inverted drive signal different from the amplitude of the phase-inverted drive signal, a pressure maximum point can be created at the center of the focal point. At this time, if the amplitude ratio is variously adjusted, the ratio between the center pressure and the pressure at the surrounding pressure maximum point can be arbitrarily adjusted. As a method, assuming that a certain amplitude is 1, the central peak pressure by simultaneous driving is calculated and this is set to 1, the amplitude of the drive signal of each vibrator is kept at 1 as described above, and the pressure by the focus enlarging method according to the present embodiment is set. Calculate the peak pressure at the local maximum. Here, it is assumed that this is 0.4. When the driving method based on the superposition of the respective driving conditions is used, the sound field formed by the driving method is equal to the above-described two types of superposition. For example, under the above conditions, the drive amplitude of the oscillator driven in the non-inverted phase is 1.4 (= 1 + 0.4), and the drive amplitude of the oscillator driven in the inverted phase is 0.6 (= | −1 + 0. 4 |)
Then, a sound field in which the center pressure and the pressure of the surrounding pressure maximum point are equal can be formed. By adjusting the drive amplitude ratio, it is possible to control the pressure ratio between the central pressure and the surrounding pressure maximum point.

Further, as shown in FIG. 5D, it is also possible to create a pressure maximum point on the central axis by changing the area ratio of the vibrator. The operator may select a combination of transducers according to the desired shape of the sound field. Alternatively, the shape of the sound field may be stored in a memory circuit in advance, and the operator may select the shape while displaying the shape. Or, pay attention to the ratio between the pressure peak on the central axis and the surrounding pressure peak, or pay attention to the shape of the sound field,
A combination of transducers may be selected.

(Second Embodiment) In the second embodiment, the number of amplifiers and the like can be reduced to simplify the configuration, but the arrangement pattern can be variously changed. FIG. 8 shows the configuration of the ultrasonic therapy apparatus according to the second embodiment.
In FIG. 8, components denoted by the same reference numerals as those in FIG. 1 indicate the same components as those in FIG. 1.

In the present embodiment, two amplifiers 111 are provided, one of which is directly supplied with the waveform signal from the waveform generating circuit 113 and the other amplifier 111 receives the phase of the waveform signal from the waveform generating circuit 113. The data is supplied via an inversion circuit 117. Thus, one amplifier 111 outputs a non-inverted drive signal, and the other amplifier 111 outputs a phase-inverted drive signal.

The arrangement pattern of the vibrator driven by the non-inverted drive signal and the vibrator driven by the phase-inverted drive signal is changed by the switching circuit 151 as described in the first embodiment. Can be changed in various ways. Further, when it is desired to drive all the oscillators in the same phase, all the oscillators are driven by one amplifier 111, or half of the oscillators are driven by the one amplifier 111,
Further, the other half of the vibrator is driven by the other amplifier 111 after the output of the phase inversion circuit 151 is not inverted.

The switching circuit 151 is for changing the electrical connection between the amplifier 111 and the vibrators 1101 to 1112, and may be constituted by a general manual switch. It can be realized by a general configuration such as an analog switch or a multiplexer.

As described above, according to the present embodiment, the number of transducers handled by one amplifier 111 is six, which is half of the total number, and the load impedance per amplifier 111 is always the same, and the simultaneous driving is performed. With the method for enlarging the size of the focal region according to the present method, there is no need to change the setting conditions of the system except for the control of the phase inversion circuit. Alternatively, a single amplifier may be used, and the output of the phase inversion circuit may be obtained using a distributor, and the switching circuit 151 shown in FIG. 8 may be connected to the output. In this manner, the amplifier 11 can be driven by the simultaneous driving method and the driving method for enlarging the size of the focal region by the present method.
Since the load impedance of 1 changes, the constant inside the amplifier 111 needs to be changed. In this case, a constant that needs to be changed may be obtained by a memory circuit or a calculation circuit (not shown), or the operator may change the constant using a switch or the like.

(Third Embodiment) FIG. 9 shows the configuration of an ultrasonic therapy apparatus according to a third embodiment. In FIG. 9, the same portions as those in FIGS. 1 and 8 are denoted by the same reference numerals, and description thereof will be omitted. Here, the description will be made on the assumption that the ultrasonic wave generating source 102 includes twelve vibrators 1101 to 1112 as shown in FIG. In the present embodiment, the arrangement pattern of the twelve transducers 1101 to 1112 is a simultaneous driving pattern, the first pattern shown in FIG. 5A, the second pattern shown in FIG. ) Can be selectively driven in either the third pattern or the fourth pattern. The choice of these patterns is
The electrical connection of the waveform generation circuit 113 or the phase inversion circuit 117 to seven of the eight amplifiers 111 smaller than the number of oscillators, for example, is changed to seven selectors S
This can be achieved by individually selecting W0 to SW6.

In the first embodiment, the amplifiers 111 are individually connected to the respective vibrators. If the number of the amplifiers is equal to the number of the vibrators, the same number, that is, 12
The number of phase inversion control circuits is required, and the configuration becomes relatively large. . On the other hand, in the second embodiment, the number of the amplifiers 111 is reduced to two by using a switching circuit. However, since one amplifier 111 needs to handle 12 or 6 oscillators. A high-output amplifier is required, and a large-volume switching circuit is required to pass large power.

On the other hand, in the third embodiment, as shown in FIG. 9, the above-described various pattern driving is performed by using three or more, here eight amplifiers 111, which are smaller than the number of transducers. This can be selectively performed.
Four of the eight amplifiers 111 are commonly connected to two non-adjacent transducers, and the remaining four amplifiers 111 are connected to the transducers one by one. Specifically, the oscillator 1101 and the oscillator 1109 are connected to the same amplifier 111, and the oscillator 1104 and the oscillator 1112
Are connected to the same amplifier 111, the vibrator 1103 and the vibrator 1107 are connected to the same amplifier 111, and the vibrator 1106 and the vibrator 1110 are connected to the same amplifier 111.

FIG. 10A shows the driving phase of the vibrator for each of the first to third patterns. Note that oscillators connected to the same amplifier and driven in the same phase are represented by the same group name. In each of the first to third patterns, a group driven in a phase inverted to each other is represented by the same alphabet with an asterisk (*) at the upper right. FIG. 10B shows a control pattern of the selectors SW0 to SW6 for each of the first to third patterns.

First, the first pattern can be performed by dividing twelve transducers into eight groups. That is,
If there are eight amplifiers 111, the first to third patterns can be switched by changing the control patterns of the seven selectors SW0 to SW6 without the switching circuit as in the second embodiment. . Seven selectors SW0
SW6 is configured by an analog switch or a relay. When the control signal is "H", the upper terminal is selected and the vibrator is driven in a non-inverted manner. On the other hand, when the control signal is "L", the lower terminal is selected. The vibrator is driven by phase inversion.

Further, as shown in FIG. 11, a phase inverting circuit 117, a selector SW and two output terminals are provided.
Phase inversion control circuit 1 capable of inverting or inverting the output phase between terminals by selector SW
If 71 is provided at each output of the amplifier 111, the amplifier becomes 4
You only need to do it. The phase inversion control circuit 171 can be realized by a circuit configuration using a transformer and selectors a and b as shown in FIG. 12, for example. Of course, another configuration may be used as long as the output phase between the terminals can be switched between non-inversion and inversion.

(Fourth Embodiment) In this embodiment, FIG.
As shown in FIG. 16, the second harmonic signal of the frequency (2 · f0) generated by the second harmonic waveform generation circuit 117 is mixed with the fundamental wave signal of the frequency f0 generated by the waveform generation circuit 113. Then, the vibrator is driven by the mixed signal. At this time, the phase in which the negative pressure is maximized in the fundamental wave signal and the phase in which the amplitude is maximized in the second harmonic signal are synchronized and mixed.

As shown in FIGS. 13 to 16, the second harmonic waveform generation circuit 11 is provided separately from the waveform generation circuit 113.
7 may be provided to mix the two signals, or a class C amplifier may be inserted to extract the fundamental wave signal by a resonance circuit, and the second harmonic signal to be extracted by another resonance circuit. Is also good. Further, the fundamental wave signal from the waveform generating circuit 113 is converted into a square wave signal by a Schmitt trigger circuit, or converted into a square wave signal through a PWM circuit, and a second harmonic signal is digitally generated and then passed through a filter circuit. A limited wave signal may be obtained.

The second harmonic signal obtained in this manner is mixed with the fundamental signal, and the vibrator is driven by a drive signal obtained by amplifying the mixed signal. Small ultrasonic waves can be generated.

By adjusting the amplitude ratio between the amplitude of the fundamental wave signal and the amplitude of the second harmonic signal, the ratio between the negative pressure and the positive pressure of the ultrasonic wave can be arbitrarily adjusted. When the electroacoustic conversion efficiency or the transfer function of the vibrator is stored and the operator specifies a desired ratio between the negative pressure and the positive pressure, the ratio between the specified negative pressure and the positive pressure is realized. Amplitude of fundamental signal and 2
The control circuit 14 may calculate the amplitude ratio with the amplitude of the second harmonic signal based on the electro-acoustic conversion efficiency or the transfer function of the vibrator.

Although an example in which the second harmonic signal is mixed with the fundamental signal has been described above, the phase at which the negative pressure is maximized in the fundamental signal and the amplitude in the second harmonic signal are increased. If the maximum phase can be synchronized and mixed, even-order harmonic signals such as the fourth, sixth, and eighth orders may be mixed with the fundamental signal.

(Fifth Embodiment) FIG. 17 shows a fifth embodiment of the present invention.
1 shows a configuration of an ultrasonic irradiation device according to an embodiment. In the figure, a treatment application 20 is provided with a treatment ultrasonic generation source 207 for generating treatment ultrasonic waves, and inserted approximately at the center of the treatment ultrasonic generation source 207, and a cross section near the focal point is tomographic image. It has an ultrasonic probe 202 for imaging for imaging as an image, and a flexible water bag 203 filled with a coupling liquid. An ultrasonic imaging device 213 is connected to the ultrasonic probe 202 for imaging, scans a cross section including a focal point by ultrasonic waves through the ultrasonic probe 202, and based on an echo signal obtained thereby, the cross section is scanned. Is generated, and this is displayed on the display device 214.

As shown in FIG. 18, the number of the therapeutic ultrasonic generators 207 is an even number, in this case, six vibrators 221 to 22.
6. Each of the six vibrators 221 to 226 is
It is composed of one piezoelectric ceramic piece formed in a substantially fan shape or a plurality of piezoelectric ceramic pieces arranged in a substantially fan shape. Such transducers 221 to 226 are arranged along the circumferential direction, and have a substantially spherical shell shape as a whole. Ultrasonic waves generated from each transducer are focused on a focal point 206 which is geometrically determined according to the curvature of the spherical shell, and treats the target 205.

Here, three vibrators 221 and 221 are used.
23 and 225 are referred to as a first vibrator, and the remaining three vibrators 222, 224 and 226 are referred to as second vibrators for distinction. The first vibrators 221, 223, 225 and the second vibrators 222, 224, 226 are alternately arranged along the circumferential direction. First vibrators 221, 223, 225
Are commonly connected to one drive system, and are supplied with the same drive signal. The second vibrators 222, 224, and 226 are commonly connected to another drive system, and are supplied with the same drive signal. The drive signal supplied to the first vibrators 221, 223, 225 has a different phase and amplitude from the drive signal supplied to the second vibrators 222, 224, 226. Accordingly, the ultrasonic waves generated from the first vibrators 221, 223, and 225 have different phases and amplitudes from the ultrasonic waves generated from the second vibrators 222, 224, and 226.

The first vibrators 221, 223, and 225 include:
The amplifier 271 is connected via the load matching circuit 261. The amplifier 271 amplifies the high-frequency waveform signal generated by the signal generation circuit 209 and delayed by the delay circuit 281, that is, phase-shifted.

The second vibrators 222, 224, and 226 include:
The amplifier 722 is connected via the load matching circuit 262. The amplifier 272 amplifies the high-frequency waveform signal generated by the signal generation circuit 209 and delayed by the delay circuit 282, that is, phase-shifted.

The delay circuits 281 and 282 are controlled by the control circuit 210 such that the delay time of the delay circuit 281 is different from the delay time of the delay circuit 282. Specifically, assuming that n is zero and a natural number and the period of the high-frequency waveform signal is T, the delay time of the delay circuit 281 is (n ·
T) / 2, the delay time of the delay circuit 282 is ((n + 1)
The delay time of the delay circuit 281 is adjusted to ((n + 1) T) / 2, and the delay time of the delay circuit 282 is adjusted to (nT) / 2.

Most preferably, the delay time of delay circuit 281 is set to zero, the delay time of delay circuit 282 is set to T / 2, or vice versa.
2, the delay time of the delay circuit 282 is adjusted to be zero.

Thus, the phase of the drive signal generated for the first oscillators 221, 223, 225 by the amplifier 271 and the second oscillators 222, 22 by the amplifier 272.
4 and 226, the phases of the driving signals generated by the first transducers 221, 223, and 225 are inverted with respect to each other, that is, 180 degrees (opposite phase). The phases of the ultrasonic waves generated from the second transducers 222, 224, and 226 are also inverted.

The amplification factor of the amplifier 271 and the amplifier 2
The amplifiers 271 and 272 are controlled by the control circuit 210 so that the amplification factor differs from that of the amplifier 72. Thus, the amplitude of the drive signal generated for the first oscillators 221, 223, and 225 by the amplifier 271 and the amplitude of the drive signal generated for the second oscillators 222, 224, and 226 by the amplifier 272 are different from each other. The first vibrator 2
The amplitudes of the ultrasonic waves generated from the first, second, and 25 are different from the amplitudes of the ultrasonic waves generated from the second vibrators 222, 224, and 226.

The operator operates the input device 211 such as a keyboard or a mouse to obtain the peak sound pressure, the position of the peak sound pressure in the sound field distribution in the focal region, the peak sound pressure at the focal center, and the peak sound pressure in the vicinity thereof. Can be set arbitrarily. The delay time of each of the delay circuits 281 and 282 necessary to realize the set peak sound pressure and the like,
272 are stored in the storage device 212 in advance.

Next, the operation of the present embodiment will be described on the assumption that a treatment ultrasonic wave is focused to cauterize the cancer cells 205 in the patient 204. When increasing the ultrasonic output, simply increasing the amplitude (drive energy) of the drive signals of the transducers 221 to 226 linearly increases the peak sound pressure at the focal point unnecessarily, and the energy is used for treatment. Not only does it not contribute effectively, but it can also cause side effects. That is, not only is the ablation region limited to the focal point, but in the vicinity of the focal point, it induces various physical effects that are not desirable for treatment, such as evaporation of water, cavitation, and acoustic streaming. As a result, it has been pointed out that side effects such as bleeding may occur.

Therefore, while enlarging the size of the focal area, the energy is dispersed so that the sound pressure does not drop off at the center of the focal point. Enables uniform treatment. As a result, efficient treatment for the input energy can be performed.

In the present embodiment, the control circuit 210 performs the above-described control, that is, control necessary for dispersing energy so that sound pressure is not lost at the center of the focal point while expanding the size of the focal region. Oversee. That is, the driving signals to the first vibrators 221, 223, and 225 and the second vibrator 2
The phase difference with the drive signal to
°, and the first vibrators 221, 223, 2
25 and the second transducers 222 and 2
The delay time of the delay circuit 281 and the delay circuit 28 so that the phases of the ultrasonic waves generated from the
2 is adjusted to T / 2 (T is the period of a high-frequency waveform signal).

Further, the amplitude of the drive signal to the first oscillators 221, 223, 225 and the amplitude of the drive signal to the second oscillators 222, 224, 226 differ from the shape and arrangement information of the oscillators 221 to 226. And the first vibrator 2
The amplitude of the ultrasonic wave generated from 21, 22, 225 and the second
The gain of the amplifier 271 and the gain of the amplifier 272 are separately adjusted so that the amplitudes of the ultrasonic waves generated from the transducers 222, 224, and 226 are different.

The data on which these delay times and amplification factors are based are stored in a storage device 212 such as an EEPROM.
At that time, the control circuit 210 also changes the size of the focus mark displayed on the screen of the display device 214 according to the size of the focus area. Note that, instead of referring to the content of the storage device 212, the control circuit 210 may calculate or input information from the input device 211.

Here, a specific example will be described. The ultrasonic generator 27 has six vibrators 221 to 226 and an aperture diameter of 20.
It is assumed that 0 mm, the inner diameter is 84 mm, and the focal length is 230 mm. After setting the phase difference between the drive signals to the first vibrators 221, 223, 225 and the drive signals to the second vibrators 222, 224, 226 to 180 °, the first vibrators 221, 22
3,225 and the second vibrators 222,224,
When the amplitude ratio with the drive signal to the 226 is set to 1: 3, as shown in FIG. 19, the sound field distribution of the focal region has a peak sound pressure point in an arc shape around the focal point center as in the related art. A peak sound pressure point is formed not only in a line but also in the center of the focal point. Considering the sound pressure half width, the focal cross-sectional area is increased by about 20 times as compared with the driving method in which driving is performed at the same amplitude without giving a phase difference. As is clear from FIG. 19, there is a valley of sound pressure between peak sound pressures, but in the case of heat treatment, the heat-denatured region has a uniform shape with no gap due to heat conduction. If the sound pressure at the center of the focal point is zero as in the related art, an unmodified region remains near the center.

Further, by changing the amplitude ratio, it is possible to control the focal region with fine texture according to the purpose of treatment. First
The phase difference between the drive signal to the transducers 221, 223, and 225 and the drive signal to the second transducers 222, 224, and 226 is 1
After being set to 80 °, the first vibrators 221, 223, and 225
If the amplitude ratio of the drive signal to the second vibrators 222, 224, and 226 is 1: 1.25, a sound field distribution as shown in FIG. 20 is obtained. That is, the sound pressure per unit area of the annular area including the peak sound pressure points arranged in an arc around the focal point center, that is, the energy density becomes substantially the same as the energy density of the minimum area at the focal center. By doing so, a sound field that realizes more uniform heating or cauterization can be formed. This sound field may be used as a heating sound field, and the above-described method of making the peak sound pressure uniform may be stored in the storage device 12 as a calculus breaking sound field, and may be selectively used depending on the purpose of treatment.

As described above, according to the fifth embodiment, while enlarging the size of the focal region, energy can be dispersed so that sound pressure does not drop at the focal center.
As a result, it is possible to treat the target in the focal region substantially uniformly while suppressing an increase in the peak sound pressure. As a result, efficient treatment for the input energy can be performed.

(Sixth Embodiment) Next, a second embodiment will be described. FIG. 21 shows the configuration of an ultrasonic irradiation apparatus according to the sixth embodiment, and the same components as those in FIG. 17 are denoted by the same reference numerals. The ultrasonic irradiation device according to the sixth embodiment is different from the ultrasonic irradiation device according to the fifth embodiment in configuration, in that the first oscillators 221, 223, and 225 and the second oscillator 2
22, 224, 226, and the fact that the amplifier 215 is shared with the first oscillators 221, 223, 225 and the second oscillators 222, 224, 226. Is different from the above. The other configuration is the same as that of the fifth embodiment, and the description is omitted.

As the amplifier 215, a general high-frequency power source or a high-frequency amplifier can be used. In the present embodiment, a conventional transformer and a transmission line transformer are used as the power distribution circuit 216. The configuration of the power distribution circuit 216 is shown in FIG. In FIG. 22, the conventional transformer 2
Reference numeral 41 is used for impedance matching. A plurality of taps are provided on the secondary side of the conventional transformer 241 to enable fine adjustment of impedance matching. In addition, it also serves to insulate the primary side and the secondary side. Generally, the frequency characteristics of the conventional transformer method are better than those of the impedance matching circuit using LC elements. Transmission line transformers 242 to 245 connected after the conventional transformer 241
Oscillator 221, 223, 225 and second oscillator 222, 2
24 and 226 at a predetermined ratio, and are used to invert the phases of the power waves.

In the present embodiment, the signal amplitude ratio is 1: 3 (1: 9 in the power ratio). However, when the amplitude ratio is expressed by an integer as described above, the transmission line transformer is easy to make and the frequency characteristic is low. It is superior to a conventional transformer in two points. Of course, a conventional transformer can be used instead of the transmission line transformer, and a method using an attenuator is also possible. Further, the impedance matching can be used as a circuit using an LC element.

In this embodiment, the same operation and effect as in the fifth embodiment can be obtained with a simple configuration.

(Seventh Embodiment) In the fifth and sixth embodiments, the drive signal to the first vibrator and the second
By providing a 180 ° phase difference between the driving signal to the vibrator and a 180 ° phase difference between the ultrasonic wave generated from the first vibrator and the ultrasonic wave generated from the second vibrator. However, in the present embodiment, the ultrasonic wave generated from the first vibrator and the ultrasonic wave generated from the second vibrator are not physically controlled by the delay time, but by the physical device.
It is characterized by providing a phase difference of 80 °. In addition,
The configuration for making the amplitude of the drive signal to the first vibrator different from the amplitude of the drive signal to the second vibrator and the configuration of other peripheral portions are the same as those in the fifth embodiment, and thus description thereof is omitted.

FIG. 23A shows the structure of an ultrasonic wave source according to the seventh embodiment in a state where it is cut out in substantially half. This ultrasonic generating source is composed of a plurality of piezoelectric ceramics, here six first vibrators 231 and the same six second vibrators 232, which are alternately arranged along the circumferential direction to form a spherical shell as a whole. The ultrasonic wave from each transducer is focused on a geometrical focal point. Note that the vibrators 231 and 232 are actually held by a support.

The distance between the ultrasonic wave emitting surface of the first vibrator 231 and the focal point 206 is greater than the distance between the ultrasonic wave emitting surface of the second vibrator 232 and the focal point 206, and the wavelength of the ultrasonic wave is WL. WL / 2, that is, the first vibrator 231 is longer than the second vibrator 232 in the ultrasonic irradiation direction.
/ 2 offset.

In other words, the distance between the ultrasonic radiation surface and the focal point 206 of the second vibrator 232 is
The distance between the ultrasonic radiation surface and the focal point 206 is shorter than the distance between the ultrasonic wave at WL and WL / 2, that is, the second vibrator 32 is closer to the ultrasonic irradiation direction than the first vibrator 31. The projection is offset by WL / 2 and is close to the focal point 206.

When all the transducers are arranged at a fixed distance from the focal point 206 as shown in FIG. 23 (b), the sound pressure at the geometrical focal point 206 becomes considerably higher than its surroundings. By setting the offset arrangement as shown in FIG. 23A, the interference state in the focal region changes as in the fifth and seventh embodiments, and the sound pressure around the center of the geometrical focal point 206 increases. And the focal region is substantially enlarged. In the case of the structure shown in FIG. 23B, the sound pressure is high and the therapeutic effect at the focal point is high, but at the same time, there is a problem that the focal point and the surrounding tissue are destroyed and bleeding occurs. By lowering the sound pressure at the focal point and raising the sound pressure around it as in the embodiment, it is possible to prevent bleeding without causing tissue destruction as in the fifth and seventh embodiments.

Further, since the sound pressure around the focal point is increased, the focal region is enlarged and the therapeutic region is also enlarged.
The irradiation time can be reduced even for a relatively large target that needs to be repeatedly irradiated, so that the treatment time can be shortened.

(Eighth Embodiment) FIG. 24 shows an eighth embodiment of the present invention.
1 shows a configuration of an ultrasonic irradiation device according to an embodiment. In the figure, a treatment applicator 301 includes a treatment ultrasonic generation source 302 for generating treatment ultrasonic waves, and a cross section including a focal region inserted into a substantially central hole of the treatment ultrasonic generation source 302. It has an ultrasonic probe 303 for imaging for imaging as a tomographic image, and a flexible water bag 304 in which an ultrasonic wave propagation medium, for example, well-degassed water 305 is sealed. The ultrasonic probe 303 for imaging includes the ultrasonic imaging device 30
8 is connected, scans a cross section including the focal region by ultrasonic waves via the ultrasonic probe 303, and generates a tomographic image (B mode image) of the cross section based on the echo signal obtained thereby. Is displayed on the display device 309 in real time.

As shown in FIG. 25, the treatment ultrasonic generating source 302 has an even number of electrically separated vibrators, here, eight vibrators 321 to 328. That is, the therapeutic ultrasound source 302 has eight channels. 8 vibrators 3
Each of 21 to 328 is formed of one piezoelectric ceramic piece formed in a substantially fan shape, or a plurality of piezoelectric ceramic pieces electrically connected by a common electrode are arranged in a substantially fan shape. Such vibrators 321 to 328 are arranged in a substantially annular shape, and have a substantially spherical shell shape as a whole. Ultrasonic waves generated from each transducer are focused on a focal point 116 geometrically determined according to the curvature of the spherical shell, and the target 1
7 to be treated.

Each of the eight vibrators 321 to 328 is provided with eight (eight channels) impedance matching circuits 310.
They are connected one to one. The outputs of the eight (8-channel) amplifiers 311 are also connected to the inputs of the eight impedance matching circuits 310 on a one-to-one basis. Further, the outputs of eight (8 channels) phase shifters 312 are connected to the inputs of the eight amplifiers 311 on a one-to-one basis.
A waveform generating circuit 313 for generating a high-frequency (frequency f0) waveform signal is commonly connected to inputs of the eight phase shifters 312.

Further, the amplifier 316 includes the waveform generation circuit 3
It is provided to amplify the waveform signal output from the block 13 as it is. The driving signal output from the amplifier 316 is added to each of the driving signals output from the amplifier 311, and the vibrators 321 to 328 are output via the matching circuit 310.
Sent to

The control circuit 314 determines that the waveform signal output from the phase shifter 312 is (2π · k) /
The phase shift amount of each phase shifter 312 is controlled so as to differ by N. N represents the number of transducers. Accordingly, the output waveform of each amplifier 311 is given by Asin (2πft + 2πk (n / N)). Note that A is the amplification factor of the amplifier 311 controlled by the control circuit 314, f is the frequency of the drive signal,
t represents time, and n represents a vibrator number (0 to 7). The transducer numbers are the transducers 321 to 328 arranged in an arc shape.
, For example, in a counterclockwise order.

By such a phase shift control, for example, FIG.
As shown in the figure, the driving signals of the vibrators 322 to 328 are respectively π / 4 and 2π
/ 4, 3π / 4, 4π / 4, 5π / 4, 6π / 4, 7π
/ 4 is provided. On the other hand, the output waveform of the amplifier 316 is given by Bsin (2πft + φ), where φ is the initial phase (fixed value). B represents the amplification factor of the amplifier 316 controlled by the control circuit 314.

The driving signal applied to the vibrators 321 to 328 is: Asin (2πft + 2πk (n / N)) + Bsin (2πf
t + φ). The control circuit 3 determines the ratio (A / B ratio) of the amplification factor A of the amplifier 311 to the amplification factor B of the amplifier 316.
By changing variously by the amplification factor control of FIG.
As shown in FIG. 6, the intensity ratio between the sound pressure at the focal point center and the sound pressure at the surroundings can be changed in various ways.

The present invention is not limited to the above-described embodiment, but can be implemented with various modifications. For example, in the above-described embodiment, a description is given in which the drive signal to the first vibrator gives a 180 ° phase difference (delay phase) between the drive signal to the second vibrator and the drive signal to the second vibrator. The following relationship may be established. 0 ° <phase difference <180 ° In this case (of course, the amplitude value is also changed), the magnitudes of the surrounding sound pressure local maximum points are alternately different values.

Further, even when the acoustic lens and the phased array method are used, the focus expanding method according to the above-described embodiment may be used.

In all of the above embodiments,
Although the ultrasonic generator is constituted by a piezoelectric ceramic vibrator, an electromagnetic induction type ultrasonic generator may be employed instead. Although only the inversion / non-inversion of the phase has been described, the driving may be performed with another phase difference such as a predetermined phase amount, for example, a delay / advance phase of 90 °.
As disclosed in Japanese Patent No. 78930, the phase amount may be changeable. Also, the vibrator separation may be realized by electrode cutting, instead of by physical cutting of the vibrator plate.

In all of the above embodiments,
Although the ultrasonic generator is described as arranging the transducers in the circumferential direction, as shown in FIG. 27, the ultrasonic generator comprises a plurality of ring-shaped vibrators 401 to 405 each having an arc T having a radius. A so-called annular type may be used.

[0096]

According to the present invention, a plurality of types of ultrasonic waves having different phases and amplitudes can be generated at the same time, so that the sound pressure local maximum exists at the center of the focus and around the focus. Can be formed. Further, since the phase can be changed for each transducer, the size of the focal region can be variously changed.

[Brief description of the drawings]

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

FIG. 2 is a schematic plan view of the ultrasonic generator of FIG.

FIG. 3A is a diagram illustrating a first example of the phase non-inverting / inverting circuit of FIG. 1;
FIG. 2B is a diagram illustrating a configuration of an example, and FIG. 2B is a diagram illustrating a configuration of a second example of the phase non-inverting / inverting circuit of FIG. 1.

FIG. 4A is a diagram illustrating a third example of the phase non-inverting / inverting circuit of FIG. 1;
FIG. 4B is a diagram illustrating a configuration of an example, and FIG. 6B is a diagram illustrating a configuration of a fourth example of the phase non-inverting / inverting circuit of FIG. 1.

FIG. 5A shows a first pattern in which a vibrator to which a non-inverted drive signal is supplied and a vibrator to which an inverted drive signal is supplied are alternately arranged one by one in the present embodiment; FIG. 3B is a diagram illustrating a second pattern in which a vibrator to which a non-inverted drive signal is supplied and a vibrator to which a reversed drive signal is supplied are alternately arranged two by two in the present embodiment;
FIG. 3C is a diagram illustrating a third pattern in which a vibrator to which a non-inverted drive signal is supplied and a vibrator to which an inverted drive signal is supplied are alternately arranged three by three in the present embodiment;
(D) shows a fourth pattern in which, in the present embodiment, three adjacent transducers to which a non-inverted drive signal is supplied and two adjacent transducers to which an inverted drive signal is supplied are alternately arranged. FIG. 7E is a diagram illustrating a fifth pattern in which a vibrator to which a non-inverted drive signal is supplied and a vibrator to which an inverted drive signal is supplied are arranged in a lattice pattern in the embodiment.

FIG. 6 is a diagram showing a sound field distribution when driven by the second pattern of FIG. 5 (b).

FIG. 7 is a view showing an example of a display screen of the display device of FIG. 1;

FIG. 8 is a diagram showing a configuration of an ultrasonic therapy apparatus according to a second embodiment of the present invention.

FIG. 9 is a diagram showing a configuration of an ultrasonic therapy apparatus according to a third embodiment of the present invention.

FIG. 10A is a diagram showing a correspondence between an array pattern and a driving phase of each transducer in the third embodiment, and FIG.
FIG. 4 is a diagram showing correspondence between an array pattern and each selector.

FIG. 11 is a diagram showing a configuration of a modification of the ultrasonic therapy apparatus of FIG. 9;

FIG. 12 is a diagram illustrating a configuration of an example of a phase inversion control circuit in FIG. 11;

FIG. 13 is a diagram showing a configuration of the ultrasonic therapy apparatus of FIG. 1 improved by the fourth embodiment.

FIG. 14 is a diagram showing the configuration of the ultrasonic therapy apparatus of FIG. 8 improved by the fourth embodiment.

FIG. 15 is a diagram showing a configuration of the ultrasonic therapy apparatus of FIG. 9 improved by the fourth embodiment.

FIG. 16 is a diagram showing the configuration of the ultrasonic therapy apparatus of FIG. 11 improved by the fourth embodiment.

FIG. 17 is a diagram showing a configuration of an ultrasonic irradiation apparatus according to a fifth embodiment of the present invention.

FIG. 18 is a schematic plan view of the ultrasonic generator of FIG. 17;

19 is a diagram illustrating a sound field distribution when the amplitude ratio of the drive signal between inversion and non-inversion is adjusted to 1: 3 by the control circuit in FIG. 17;

20 is a diagram showing a sound field distribution when the amplitude ratio of the drive signal between inversion and non-inversion is adjusted to 1: 1.25 by the control circuit in FIG. 17;

FIG. 21 is a diagram showing a configuration of an ultrasonic irradiation apparatus according to a sixth embodiment of the present invention.

FIG. 22 is a diagram illustrating a configuration of a power distribution circuit in FIG. 21;

FIG. 23A is a view of an ultrasonic irradiation apparatus according to a seventh embodiment of the present invention in which an ultrasonic wave generating source is cut in half vertically and viewed from the side, and FIG. The figure which shows a comparative example.

FIG. 24 is a diagram showing a configuration of an ultrasonic irradiation apparatus according to an eighth embodiment of the present invention.

FIG. 25 is a diagram showing the phase of a drive signal supplied to each transducer of FIG. 24;

FIG. 26 is a diagram showing a change in sound field distribution by changing the amplitude ratio A / B in the phase pattern of FIG. 25;

FIG. 27 is a diagram showing an annular type ultrasonic wave generating source.

FIG. 28 is a diagram showing a sound field distribution of a conventional enlarged focal region.

[Explanation of symbols]

 Reference numeral 101: therapeutic applicator 102: therapeutic ultrasonic source 103: ultrasonic probe for imaging 104: water bag 105: degassed water 106: patient (subject) 107: cancer cells 108: Ultrasonic imaging device 109 Display device 110 Impedance matching circuit 111 Amplifier phase non-inverting / inverting circuit 113 Waveform generating circuit 114 Control circuit 115 Console 110 Focus.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Satoshi Aida 1385-1, Shimoishigami, Otawara-shi, Tochigi Prefecture Inside the Toshiba Nasu Plant (72) Inventor Hideki Ozaku 1385-1, Shimoishigami, Otawara-shi, Tochigi Stock Company Inside the Toshiba Nasu Factory

Claims (20)

[Claims] A plurality of transducers for generating a plurality of ultrasonic waves focused on a focal point by applying a plurality of drive signals; and a plurality of transducers for generating the drive signals with variable phases and amplitudes. An ultrasonic therapy apparatus comprising: a drive unit; and a control circuit that individually controls the drive unit to set the phase and amplitude of each of the drive signals. 2. The control circuit sets a phase and an amplitude of each of the drive signals such that a sound pressure at a center of the focus and a peak sound pressure around the focus substantially coincide with each other. The ultrasonic therapy device according to claim 1, wherein 3. The control circuit according to claim 2, wherein the energy density of a central area of the focal point is substantially equal to the energy density of a circumferential area including a sound pressure maximum point around the focal point. The ultrasonic therapy apparatus according to claim 1, wherein the phase and the amplitude are set. 4. The driving unit, wherein each of the driving units selectively inverts a phase of a high-frequency waveform signal, and selectively outputs the first inverted waveform signal and the second non-phase inverted waveform signal. The ultrasonic therapy apparatus according to claim 1, further comprising: a selector that outputs the signal; and an amplifier that amplifies the first waveform signal or the second waveform signal output from the selector. 5. Each of the driving units includes an amplifier for amplifying a high-frequency waveform signal to generate a driving signal, a phase inverting circuit for inverting a phase of the driving signal, and a first inverting driving signal. The ultrasonic therapy apparatus according to claim 1, further comprising a selector for selectively outputting the second drive signal that has not been phase-inverted. 6. The control circuit changes a combination of a vibrator driven by the first drive signal and a vibrator driven by the second drive signal to change the size of the focal point. The ultrasonic therapy apparatus according to claim 1, wherein . 7. The ultrasonic therapy apparatus according to claim 1, further comprising means for mixing a harmonic signal with the driving signal. . 8. The ultrasonic therapy apparatus according to claim 1, wherein each of the drive units is commonly connected to at least two non-adjacent transducers. 9. A plurality of first transducers for generating a plurality of first ultrasonic waves focused on a focus by applying a plurality of first drive signals, and applying a plurality of second drive signals. By the above, the first
A plurality of second transducers for generating a plurality of second ultrasonic waves focused on the same focal point as the ultrasonic waves; a first drive unit for generating the first drive signal by changing the phase and amplitude; A second drive unit that generates a drive signal by changing the phase and amplitude; and a first drive unit and a second drive unit that differ in phase and amplitude between the first drive signal and the second drive signal. 2
An ultrasonic treatment apparatus comprising: a control circuit for controlling a driving unit. 10. The apparatus according to claim 9, wherein at least one of said first drive signal and said second drive signal has a delay circuit, and a delay time of said delay circuit is controlled by said control circuit. Ultrasound therapy device. 11. The apparatus according to claim 9, wherein each of the first driving unit and the second driving unit has an amplifier, and an amplification factor of the amplifier is controlled by the control circuit.
The ultrasonic therapy apparatus according to claim 1. 12. The ultrasonic treatment apparatus according to claim 9, wherein the first transducer and the second transducer are arranged so as to be adjacent to each other. 13. The device according to claim 12, wherein the first drive unit is commonly connected to the first vibrator, and the second drive unit is commonly connected to the second vibrator. Ultrasound therapy device. 14. The ultrasonic treatment apparatus according to claim 9, further comprising: means for mixing a harmonic signal with at least one of the first drive signal and the second drive signal. 15. A plurality of first transducers for generating a first ultrasonic wave focused on a focus by applying a first drive signal, and a plurality of first vibrators for applying a second drive signal to the first transducer. Generating a second ultrasonic wave focused on the same focal point as the sound wave, a plurality of second vibrators arranged so as to be adjacent to the first vibrator and a second ultrasonic wave generating the first drive signal; An ultrasonic therapy apparatus comprising: a first drive unit; and a second drive unit that generates the second drive signal so that the second drive signal is in a phase opposite to the first drive signal. 16. A plurality of first transducers for generating a first ultrasonic wave focused on a focus by applying a first drive signal, and a plurality of first transducers for applying a second drive signal. Generating a plurality of first ultrasonic waves that focus on the same focal point as the sound waves;
A vibrator, a drive unit for generating a drive signal, and a drive unit for distributing the drive signal to the first drive signal and the second drive signal, wherein a phase of the first drive signal and the second drive signal And a distributor having means for making the phase of the first drive signal different from that of the first drive signal, and means for making the amplitude of the first drive signal different from the amplitude of the second drive signal. A driving unit that generates a high-frequency driving signal; a plurality of first transducers that generate a first ultrasonic wave focused on a focal point by applying the driving signal; It generates a second ultrasonic wave focused on the same focal point as the first ultrasonic wave, and comprises a plurality of second vibrators provided at a position closer to the focal point than the first vibrator. Ultrasonic therapy equipment. 18. The ultrasonic wave according to claim 17, wherein the second vibrator is closer to the focal point by a half wavelength of the first and second ultrasonic waves than the first vibrator. Treatment device. 19. The apparatus according to claim 17, further comprising: means for making the amplitude of the drive signal applied to the first vibrator different from the amplitude of the drive signal applied to the second vibrator. Ultrasound therapy equipment. 20. The apparatus according to claim 20, further comprising means for mixing a harmonic signal into at least one of the drive signal applied to the first oscillator and the drive signal applied to the second oscillator. Item 18. The ultrasonic treatment device according to Item 17.