Ultrasonic irradiation apparatus

An ultrasonic irradiation apparatus irradiates ultrasonic waves onto a wide area having three-dimensionally curved surfaces. An ultrasonic irradiator having a plurality of ultrasonic transducer is arranged in a plane. The position of at least a portion of the ultrasonic transducers is mutually and flexibly changeable in three dimensions. Ultrasonic transducers are installed on a surface of a flexible and/or elastic sheet member or net member. The ultrasonic irradiator may include a plurality of ultrasonic transducers formed on a flexible piezoelectric sheet member, including driving electrodes arranged on one surface and opposed electrodes arranged on another surface. The ultrasonic irradiator may be installed on or inside of a flexible planar bag containing a fluidic ultrasonic conductive medium. A mechanism is provided for moving or tilting the ultrasonic irradiator with respect to the object, or a band-holding member may be provided for fitting the irradiator to the object.

CROSS-REFERENCE TO RELATED APPLICATION

This application is the U.S. national phase of PCT application number PCT/US01/16929, filed May 24, 2001, which further claims priority to U.S. patent application Ser. No. 09/578,024, filed May 24, 2000.

TECHNOLOGICAL FIELD

The present invention relates to an ultrasonic irradiation apparatus for irradiating, with ultrasonic waves, a wide area of an object to be irradiated such as a living body.

BACKGROUND ART

The inventor of the present invention conducted research and discovered that fats within a living body were decomposed (lipolysis) by irradiating the living body with ultrasonic waves having a specific frequency. A patent application regarding an ultrasonic wave irradiation apparatus was filed and published as PCT Publication Number WO 99/39677 on Aug. 12, 1999.

In the practice of the previous invention, it was required to irradiate the living body with ultrasonic waves. The living body has wide three-dimensionally curved surfaces composed of complicated uneven surfaces such as, e.g., the abdominal region, the thighs, the buttocks or the chin. Therefore, it is difficult to evenly irradiate the surface of a living body with ultrasonic waves.

To solve such a problem, in the published international patent application, there was disclosed:

(1) an apparatus, having an ultrasonic transducer arranged on a side wall of a bath tub, for irradiating a living body via hot water in the bath tub with ultrasonic waves generated by the ultrasonic transducer;

(2) an apparatus, having an ultrasonic transducer arranged on the bottom of a water chamber having an upper side thereof left open, for irradiating, with ultrasonic waves, a living body contacting the water on the upper opening area via the water in the water chamber; and

(3) an apparatus, having an ultrasonic transducer arranged within a shower head, for irradiating, with ultrasonic waves, a living body via water or hot water flowing out from the shower head.

It has been known to irradiate with ultrasonic waves for, e.g., enhancing beauty, acceleration of blood circulation and for curing stiffness in the shoulder or lumbago, and some conventional ultrasonic irradiation apparatuses have been known for these purposes. The conventional ultrasonic irradiation apparatus has a single ultrasonic transducer having a diameter of about 20 to 50 mm, and irradiation, with ultrasonic waves, over a desired wide area of a living body is performed by scanning the living body surface with an acoustic output part of the apparatus.

In the conventional ultrasonic irradiation apparatus, ultrasonically irradiating the living body having three-dimensionally curved surfaces is easily conducted without large size equipment such as a bath tub, a water chamber or a shower system, because scanning can cover the living body surface to some extent. But, when the scanning area becomes wider, in the conventional system it requires a long time to scan wider areas because of the time required to manually scan the single ultrasonic transducer to accumulate the necessary irradiation dose (intensity of irradiation×the accumulated time of irradiation) per unit surface area. Hence, the work load for an operator, such as a doctor, becomes heavier.

In the published international patent application, an apparatus has been disclosed, having a single ultrasonic transducer and an acoustic lens arranged in front of the ultrasonic transducer, for irradiating a living body with ultrasonic waves through a bag containing an ultrasonic conducting medium such as, e.g., water or jelly. In the system of the published patent application, it is possible not only to make close contact with a living body via the water bag, but also to expand the area of irradiation greater than using a sole ultrasonic transducer, due to a function of the acoustic lens, and thereby one is able to effectively scan the living body.

However, in the case where the area to be scanned is wider, the system disclosed in the published international patent application has the same problems as the conventional ultrasonic irradiation apparatus. In other words, it takes a long time to scan wider areas and the load imposed on the operator becomes heavier.

Further, in the apparatus for irradiating ultrasonic waves via a bag containing an ultrasonic conducting medium, the distance between the acoustic lens and a window portion of the bag, which outputs ultrasonic waves and which is in contact with the living body, must become longer to make the irradiation area wider, and thus the amount of water is increased. As the result, the pressure of the water weight is transferred to the living body, and it is difficult to make adjustments so as to partially support and lessen the pressure due to such weight. Further, in the apparatus for irradiating with ultrasonic waves via the bag containing the ultrasonic conducting medium, the position of the living body to be irradiated with ultrasonic waves is limited because, if the irradiation direction to the living body is not vertical, the output window of the bag is greatly deformed by gravity and thereby it is difficult to scan smoothly.

DISCLOSURE OF THE INVENTION

An object of the present invention is to provide an apparatus capable of easily irradiating, with ultrasonic waves, a wide area of an object having three-dimensional surfaces.

To accomplish the above object, an ultrasonic irradiation apparatus according to the present invention comprises an ultrasonic irradiator including a plurality of ultrasonic transducers arranged in a planar pattern wherein at least a portion of the ultrasonic transducers are mutually and flexibly deformable in three dimensions. In the present patent application, the term of “flexibly deformable in three dimensions” also includes the meaning of “flexibly deformable in two dimensions.”

In the ultrasonic irradiation apparatus according to the present invention, an area within the object, where ultrasonic waves can be irradiated at one time, becomes considerably wider than in the conventional apparatus having a single ultrasonic transducer, because the plurality of ultrasonic transducers are arranged in a planar pattern. Thus, the load imposed on the operator can be reduced when irradiating a wide area of the object with ultrasonic waves.

Further, in the ultrasonic irradiation apparatus according to the present invention, at least a portion of the plurality of ultrasonic transducers arranged in the planar configuration are mutually deformable in three dimensions. As a result, the ultrasonic transducers can be fitted along the surface of the object having three-dimensionally curved surfaces, such as a living body, and the object can be evenly irradiated with ultrasonic waves.

The ultrasonic irradiation apparatus according to the present invention is characterized in that the plurality of ultrasonic transducers are arranged on a flexible and/or elastic sheet member, so as to be mutually deformable in three dimensions. As examples of the flexible and/or elastic sheet member, several types of rubber sheet members, foamed rubber sheet members, such as expanded butylene or expanded silicon, fabrics or unwoven textiles may be applicable.

A sheet member having elasticity is preferable, although one having only flexibility may be used. In the case where the sheet member has only flexibility, the sheet member should have good flexibility in one direction, but the sheet member should be difficult to be deformed in a direction transverse to the direction which is deformed first.

Therefore, it is preferable that the sheet member has a plurality of linear recesses (this word is used interchangeable with the term “slot” hereafter) so that the sheet member is flexibly deformed based on both edges of the linear recesses becoming apart from each other. Thereby, when the sheet member is deformed in a direction along the linear recesses, the sheet can be also deformed in a direction transverse to the linear recesses, and the position of the ultrasonic transducers can be mutually deformed in three dimensions. The shape and width of the linear recesses may be freely determined.

The linear recesses should be formed from one surface toward the other surface in the sheet member, and may or may not penetrate though to the other surface.

Further, the ultrasonic irradiation apparatus according to the present invention is characterized in that the plurality of ultrasonic transducers are arranged on a net member having flexibility and/or strechability, so that the position of the plurality of ultrasonic transducers is mutually deformable in three dimensions. As the flexible net member, a material is used that is composed of at least one type of material selected from a string, a band, a spring, a chain, and rods that are linked so as to be mutually rotatable.

Further, the ultrasonic irradiation apparatus according to the present invention is characterized in that the plurality of ultrasonic transducers making up the ultrasonic irradiator are composed of driving electrodes arranged on one surface of a flexible piezoelectric sheet member and opposed electrodes arranged on the other surface of the flexible piezoelectric sheet member, facing each other. Hence, the position in the plurality of ultrasonic transducers is mutually deformable in three dimensions. As the flexible piezoelectric sheet member, a sheet member composed of an organic piezoelectric material such as polyvinylidene fluoride (PVDF), or a sheet member composed of a plastic material kneaded with piezoelectric particulates, comprising ceramics such as Pb(Zr*Ti3)O3(PZT), can be used.

The flexible piezoelectric material has a characteristic of good flexibility in one direction, but when the flexible piezoelectric material is deformed in the one direction, the flexible piezoelectric material is difficult to be deformed in a direction transverse to the deformed direction. Therefore, it is preferable that the flexible organic piezoelectric material has a plurality of linear recesses and is flexibly deformable based on the edges of the linear recesses moving apart from each other. Thereby, when the flexible organic piezoelectric material is deformed in a direction along the linear recesses, the material can also be deformed in a direction crossing the linear recesses, and the position of the ultrasonic transducers can be mutually deformed in three dimensions. The shape and width of the linear recesses may be freely determined.

The linear recesses should be formed from one surface toward the other surface in the piezoelectric material, and may or may not penetrate the piezoelectric material through to the other surface.

In any one of the ultrasonic irradiators described above, it is preferable that a soft material layer or a fluidic material layer, which is composed of an ultrasonic conducting medium for transferring ultrasonic waves to an object to be irradiated, be arranged between the ultrasonic irradiator and the object. Thereby, an additional function, such as optional setting of temperature, can be achieved with the soft material layer or the fluidic material layer.

It is preferable, in the ultrasonic irradiator in which a plurality of ultrasonic transducers are arranged in a plane, or in any of the ultrasonic irradiators described above, that said transducers be arranged on the surface of a planar bag which has a fluidic material serving as an ultrasonic conducting medium and which has flexibility. Thereby, the ultrasonic irradiator and the planar bag can be integrated, and handling becomes easier.

Such a bag is deformable because the bag itself is flexible and contains the fluidic material therein. However, it is applicable further to arrange a tube, channeling the outside of the bag and the inside of the bag, and a pump for changing a volume of the fluidic material in the bag over time, by adding/reducing the fluidic material through the tube. Thereby, the shape of the bag can be intentionally deformed.

In the case where an output plane (window) of ultrasonic waves of the bag is applied vertically to a living body, an offset of the output plane due to blisters or inferior contact between the bag and the living body may be caused, because the fluidic material is pulled down toward a bottom portion of the bag due to gravity and the like. Therefore, it is preferable that the bag has a connection member for connecting an internal upper plane and an internal bottom plane in the bag, and for maintaining a maximum distance between the internal upper plane and the internal bottom plane at least within a predetermined range.

In the ultrasonic irradiation apparatus according to the present invention, a plurality of ultrasonic transducers being arranged in plane, or any one of the ultrasonic irradiators described above may be arranged on the inside of a flexible planar bag having at least one flexible surface (window), and containing a fluidic material as the ultrasonic conducting medium, for averaging a local intensity variation caused by interference between the ultrasonic waves mainly of the adjacent transducers overlapping within the object, while irradiating the object having three-dimensionally curved surfaces, and also averaging an uneven spatial distribution of the sonic field caused by the arrangement of the ultrasonic transducers. The flexible planar bag may also have elasticity. Then, in the ultrasonic irradiation apparatus according to the present invention, it is preferable that at least one surface of the ultrasonic irradiator be arranged so as to be easily moved along the plane portion of the flexible planar bag and/or so as to be easily tilted to the plane portion of the flexible planar bag. Because the ultrasonic irradiator is arranged so as to be easily moved and/or tilted as described above, the position of the ultrasonic transducers in the ultrasonic irradiator with respect to an object can be relatively changed. Thereby, it is possible to spatially average any unevenness of the sonic field caused by overlap, as described above, as well as any unevenness caused by the arrangement of the ultrasonic transducers.

The planar bag having at least one flexible plane is easily handled when a back plane opposed to the window plane for outputting ultrasonic waves is made rigid. Also the rigid back can be a base member for moving or tilting the ultrasonic transducers. The planar bag having at least one flexible plane comprises a plurality of straight recesses arranged mutually in parallel on the back plane so as to be flexibly deformable in a direction transverse to the straight linear recesses. Thereby, the planar bag can be deformed in the direction transverse the straight recesses, and with respect to a curved surface along the straight recesses, the flexibility of an output window can adaptively accommodate the curvature. Then, the planar bag having at least one flexible plane can be fitted three-dimensionally with the object. In this case, the weight of the flexible planar bag becomes light because the deformation of the flexible plane, serving as the output window, becomes slight and the thickness of the fluidic material can be kept thin.

In the ultrasonic irradiation apparatus according to the present invention, the soft material or the fluidic material serving as an ultrasonic conducting medium is preferably a hot pack (i.e., a heatable high specific heat material) or a cold pack (i.e., a refrigeratable high specific heat material). The effectiveness of irradiation by ultrasonic waves with respect to the object can be improved by controlling the temperature of the contacting surface of the soft material or the fluidic material, which has been heated or cooled previously. In the case where the object is a human body, the tactile feeling of the object can be improved by previously heating or cooling the soft material or the fluidic material.

The ultrasonic irradiation apparatus according to the present invention is characterized in that the ultrasonic irradiation apparatus has a band-like holding member for fitting the ultrasonic irradiator to the object. Because the ultrasonic irradiation apparatus has such a band holding member, the ultrasonic irradiator can be held and fitted to the object, and the load on the operator can be greatly reduced.

Then, the ultrasonic transducers are preferably arranged so as to be easily moved, reciprocating along a length and/or width direction in the band-like holding member, to average a local variation of the sonic field caused by interference of adjacent ultrasonic transducers, or to average an uneven spatial distribution of the sonic field caused by the arrangement of the ultrasonic transducers at the inside of the object.

The ultrasonic irradiation apparatus according to the present invention is characterized in that the ultrasonic irradiator comprises means for being driven electrically by at least two or more drive systems, each of which drives the plurality of ultrasonic transducers in mutually different electrical conditions. Thus, a spatial distribution of intensity caused by interference at overlapping portions of each sonic field of the ultrasonic transducers is averaged, without being fixed only by a single drive system, while each ultrasonic transducer position is mutually deformed in three dimensions.

In the ultrasonic irradiation apparatus according to the present invention, the ultrasonic irradiator comprises the aforementioned driving means, so that each of the plurality of ultrasonic transducers are driven in mutually different conditions. Hence, the position on which ultrasonic waves from each ultrasonic transducer overlap within the object is constantly changed. Thereby, in the ultrasonic irradiation apparatus according to the present invention, the irradiation dose of ultrasonic waves inside the object is spatially averaged, and an excessive or insufficient dose of irradiation at some specific portion within the object can be avoided.

In the ultrasonic irradiation apparatus according to the present invention, it is preferable that the ultrasonic irradiator comprises an impedance adjusting means for adjusting an output allocation to the plurality of ultrasonic transducers, so that each sonic field of transducers forms a predetermined intensity ratio when each transducer position is mutually deformed three-dimensionally, and wherein the impedance adjusting means is arranged in parallel to each transducer or to a predetermined set of transducers. In the ultrasonic irradiation apparatus according to the present invention, the ultrasonic irradiation apparatus comprises the aforementioned impedance adjusting means, and thus it is possible to adjust the output allocation of each transducer so that the irradiation distribution of the ultrasonic waves within the object becomes a specified or even distribution.

In the ultrasonic irradiation apparatus according to the present invention, the ultrasonic irradiator may have an approximately resonant inductance to each ultrasonic transducer, which is adjustable, so that a sonic field from each ultrasonic transducer acquires a predetermined intensity ratio, and the inductance may be arranged in series to each ultrasonic transducer, or to a set composed of a predetermined number of ultrasonic transducers. In the ultrasonic irradiation apparatus according to the present invention, the ultrasonic irradiation apparatus comprises the adjustable inductance. Hence, it is possible to adjust the output allocation to each transducer so that the intensity distribution of the ultrasonic waves within the object becomes a specified or even distribution.

The ultrasonic irradiation apparatus according to the present invention is characterized in that the ultrasonic irradiator, having a plurality of ultrasonic transducers arranged in plane on a surface of a rigid sheet member, is arranged inside of a planar bag which contains a fluidic material as an ultrasonic conducting medium, and which has at least one flexible plane surface. Thus, the ultrasonic irradiation apparatus is capable of contacting an object having three-dimensionally curved surfaces, such as a living body, with the flexible plane surface of the planar bag. Therefore, even though a plurality of ultrasonic transducers are installed on the surface of the rigid sheet member in the ultrasonic irradiator arranged inside the planar bag, it is possible to easily irradiate with ultrasonic waves a wide area of an object having three-dimensionally curved surfaces.

PREFERRED EMBODIMENTS OF THE PRESENT INVENTION

Embodiments of the present invention are described in detail by referring to the attached figures as follows.

First, with reference toFIG. 1throughFIG. 3, an ultrasonic irradiation apparatus according to the first embodiment of the present invention shall be described.

The ultrasonic irradiation apparatus, according to this embodiment is an apparatus for irradiating a living body with ultrasonic waves, mainly for lipolysis, but it can be also used for other purposes such as acceleration of the bloodstream, infiltration of an endermic medicine, and so on. In the first embodiment, as shown inFIG. 1, an ultrasonic irradiator3acomprises a plurality of ultrasonic transducers1aand1binstalled on one surface of a sheet member2. In the case where the sheet member2is sound-conductive, the ultrasonic transducers1aand1bcan be appropriately arranged on any of inside and/or outside planes of the sheet member2.

The ultrasonic transducers1aand1bmay be ones having a driving electrode arranged on one plane of a piezoelectric element composed of ceramics (e.g., PZT (Pb(Zr*Ti3)O3), etc.) and an opposed ground electrode arranged on the other plane of the piezoelectric element. The ultrasonic transducers1aand1boutput ultrasonic waves by applying a drive voltage of a predetermined frequency between the driving electrode and the opposed ground electrode. The ultrasonic transducers1aand1bcan be a composed one of mutually adhered two piezoelectric elements in a pair, by placing each driving electrode in contact between opposed ground electrodes at both outer sides. In this embodiment, each group of ultrasonic transducers1aand1bis connected via conductors4aand4bto respective different drive systems, and for example, can be turned on or off at a mutually inverse timing. Of course, the device can be driven by keeping all of them in a same condition, without being separated into respectively different groups such as1aor1b.

The sheet member2is preferably made of a material that is flexible and/or elastic, and which can be formed by several types of rubber sheet members, foamed rubber sheet members such as expanded butylene or expanded silicon, fabrics or unwoven textiles, etc. Because the sheet member2has flexibility and elasticity, each position of the ultrasonic transducers1aand1bcan be adaptively changed to fit to a three-dimensionally curved living body surface, such as the abdominal region, the thigh, the buttocks, the chin and so on. The ultrasonic transducers1aand1bare normally installed on the sheet member while being set slightly apart by a thickness of the transducer, so that the opposed ground electrode side can contact the living body surface.

The ultrasonic irradiator3afurther comprises a joining member5composed of a pair of plane fasteners5aand5b(e.g., Magic Tape manufactured by KURARAY CO., LTD. [Trademark]) at the periphery of the ultrasonic irradiator3a, and a plurality of ultrasonic irradiators3aare arranged to be joined together via the joining member5.

In the ultrasonic irradiator3a, it is preferable to arrange an air back layer, such as a material containing air foam or an air layer, on the back side of the assembly made up of the sheet member2and the ultrasonic transducers1aand1b, so as to reflect, by means of the air foam or air layer, the radiation of ultrasonic waves coming from the ultrasonic transducers1aand1btoward the living body side contact sheet member2. Thereby, all of the ultrasonic energy is output from each of the ultrasonic transducers1aand1btoward the front living body contact side of the sheet member2assembly and an output plane is formed at the front side. In this case, the resonance frequency characteristic of the ultrasonic transducers1aand1bacquires a sharp narrow band. However, a narrow band is sufficient in the case where the ultrasonic transducers1aand1birradiate continuous waves (CW).

However, in the case where the ultrasonic transducers1aand1birradiate pulse waves, it is necessary for the spectrum to be of a broad band, by arranging a sonic absorbing layer (e.g., a rubber containing a metal powder, etc.) on the back side of the sheet member2and/or the ultrasonic transducers1aand1b. The air back layer or the sonic absorber layer may be laminated onto the back side of the assembly made up of the sheet member2and the ultrasonic transducers1aand1b. Alternatively, the sheet member2may be arranged so as to function as the air back layer by including air foams therein, or to function as the sonic absorber layer by including metallic powders therein. The front side of ultrasonic irradiator3acan have an impedance layer acoustically matched with the living body, an insulation layer and a ground electrode layer, etc., formed in the irradiator on the side of the living body.

It is preferable that an insulation layer and/or a conductive layer be further arranged on the front side of the assembly made up of the sheet member2and the ultrasonic transducers1aand1b, by laminating such layers on the electrode or by lapping them at a certain distance. Thereby, it is possible to avoid an electric current from leaking to the living body, or for unnecessary electromagnetic radiation to be radiated outwards, because the conductive layer can be connected to a ground electric potential. The conductive layer may be arranged by using a process for adding conductivity to the back surface of the sheet member2, or by laminating an aluminum fiber fabric onto the back side of the sheet member2assembly.

In the case where the sheet member2is composed of several types of hard rubber sheet material, the sheet member2may possess only flexibility without elasticity. In this case, it is preferable to arrange a plurality of linear recesses2a(as indicated by hypothetical lines) on the surface of the sheet member2, as depicted inFIG. 1. By providing the linear recesses2ain the sheet member2, when the sheet member2is deformed along the linear recesses2a, the opening of the linear recesses2ais changed into a ship shape by causing the upper edges of the linear recesses2ato move apart, and the sheet member2also becomes easily deformable in a direction transverse to the linear recesses2a.

The linear recesses2aare arranged between the ultrasonic transducers1aand1band need not necessary be straight lines. Further, it is not necessary that the linear recesses2abe mutually parallel. Further, the width of the linear recesses2amay be freely determined. The linear recesses2aare arranged from one surface toward the other surface in the sheet member, and may or may not penetrate through to the other surface.

Next, it shall be explained, by referring toFIG. 1andFIG. 2, how to use the ultrasonic irradiation apparatus according to the above embodiment.

In one exemplary usage, the ultrasonic irradiator3ais shown cross sectionally inFIG. 2corresponding to a portion of the cross section II-II shown inFIG. 1, wherein the ultrasonic transducers1aand1bare arranged to fit along a three-dimensionally curved surface of a living body6such as the abdominal region, the thigh, the buttocks, the chin, and so on. Then, the ultrasonic irradiator3ais joined to an adjacent ultrasonic irradiator3awith a joining member5composed of a pair of plane fasteners5aand5b, and a fluidic material layer7, serving as an ultrasonic conducting medium, is provided between the living body6and the ultrasonic irradiator3a.

The fluidic material layer7functions as an acoustic coupling medium for eliminating air between the ultrasonic transducers1aand1band the living body6, as well as for securing an acoustic coupling between the ultrasonic transducers1aand1band the living body6. A material for the fluidic material layer7is, e.g., acoustic jelly.

In the case where the ultrasonic irradiation apparatus irradiates a human with ultrasonic waves, it is required to wash and disinfect the ultrasonic irradiator3aevery time it is used, and so on. Therefore, when jelly is used as the fluidic material layer7, the jelly is preferably water-soluble. The sheet member2is preferably waterproof and tolerant to disinfectants.

In the present ultrasonic irradiation apparatus, it is possible to interpose a soft material layer, such as a gel material like agar, in place of the fluidic material layer7, and further to interpose similar or other materials along with the sound conducting sheet member2. For example, a hygroscopic polymer, containing a large amount of water, etc., is applicable as the gel material like agar, and a non-foam containing rubber or the like is applicable as the sound conductive sheet member2.

Further, the fluidic material layer7, or the material substituted therefor, preferably is formed of a heatable or refrigeratable high specific heat material (hot pack or cold pack), whereby it is possible to enhance the effectiveness of the irradiation with ultrasonic waves to the living body6by controlling the temperature of the fluidic material layer7, or the substituted material, by heating or cooling thereof in advance. In the case of irradiating a human with ultrasonic waves, the tactile feeling of the object can be improved by using the fluidic material layer7, or the substituted material, which has been heated or cooled.

In the ultrasonic irradiation apparatus, fats in the living body6are decomposed (lipolysis) by irradiation with ultrasonic waves (e.g. 500 kHz at 110 mW/cm2). Then, when sonic fields of ultrasonic waves from the ultrasonic transducers overlap within the living body6, due to mutual interference, some parts having added pressure amplitudes and other parts having reduced pressure amplitudes are generated. Thus, in such overlapping portions of the pressure amplitude, the irradiation dose of ultrasonic waves may be excessive or insufficient.

When the irradiation dose of ultrasonic waves becomes excessive at certain portions in the living body, heat may be generated or tissues may become injured in such portions. Therefore, the Thermal Index (TIS) and the Mechanical Index (MI) have been introduced as a measure of the irradiation dose of ultrasonic waves to the living body by Food and Drug Administration (FDA) of the United States of America (U.S.A.). According to FDA publications, a safe range for irradiation values to the living body is TIS=2 and MI=0.3.

TIS is a numerical value for soft tissues in the Thermal Index, wherein TIS=2 means that the temperature of the soft tissues is raised 2° C. during continuous irradiation of ultrasonic waves. For a living body at 36° C., this implies a temperature of 38° C. This temperature is often encountered in catching a cold and is positively safe to the living body.

On the other hand, the Mechanical Index indicates a degree where tissues are injured by cavitation. MI=0.3 is a safe level to any mammal.

When the ultrasonic irradiation apparatus irradiates with ultrasonic waves of 500 kHz at 110 mW/cm2, as mentioned above for lipolysis in the living body6, even if the strength of ultrasonic waves becomes 800 mW/cm2due to overlapping of the ultrasonic waves, it is still within a safe range because TIS remains 2 or below and MI remains 0.3 or below. Normally, upon overlapping of two ultrasonic transducers, the ultrasonic wave strength never exceeds being doubled, i.e., 220 mW/cm2or more. But, during other uses, the overlapping of the ultrasonic transducers1aand1bshould not be ignored.

Therefore, in the ultrasonic irradiation apparatus, the ultrasonic transducers1aand1bare each driven respectively by different drive systems, which are arranged in a cross-stripes pattern. Thereby, each of ultrasonic transducers1aand1bis arranged to avoid unnecessary overlapping of the sonic fields of the ultrasonic transducers1aand1b, so that each ultrasonic transducer1bis in the center of each rhombus making up a system (or group) of the ultrasonic transducers1a. Further, each of the ultrasonic transducers1ais in the center of each rhombus making up a system (or group) of the ultrasonic transducers1b.

In the ultrasonic irradiation apparatus, it is possible to drive each of the ultrasonic transducers1aand1bvia each of conductors4aand4bwhich are respectively connected to different driving systems, by turning them ON/OFF at a mutually inverse timing. Thereby, overlapping of the sonic fields in the ultrasonic transducers1aand1bis never generated.

To avoid that the irradiation dose of ultrasonic waves becomes excessive or insufficient due to overlapping of the sonic fields of the ultrasonic transducers1aand1b, an example of driving the ultrasonic transducers1aand1bby turning them ON/OFF at a mutually inverse timing has been discussed. However, as an alternative, while constantly driving one of the ultrasonic transducers1aor1bat a fixed timing, the other one can be driven via a phase-shifted circuit, which is continuously changed in phase, or can be driven by continuously and slightly changing its frequency. Thereby, the added and reduced portions of the pressure amplitudes due to interference are continuously kept moving in the living body6, so that the irradiation dose of ultrasonic waves is averaged within the region irradiated by the ultrasonic waves. Therefore, it is possible to keep the irradiation dose of ultrasonic waves from becoming either excessive or insufficient. It is also possible to make the distribution of the output strength (mW/cm2) uniform at the irradiation output plane, or to make the distribution shape like a plateau or mountain, by weakening the edge portion of the distribution and strengthening the center portion of the distribution.

Adjusting the output allocation for each of the ultrasonic transducers1aand1bmay also be used in place of the method of changing the driving means of the ultrasonic transducers1aand1b.

As one method for adjusting the output allocation of each of the ultrasonic transducers1aand1b, it is applicable to connect a transformer for impedance conversion in parallel to the unit where each of the ultrasonic transducers1aand1b, or a plurality of ultrasonic transducers1aand1b, are connected in series or in parallel. Thereby, the ultrasonic transducer unit is connected to the secondary side of the transformer and a driving power source is connected to the primary side of the transformer. In the case of using a transformer for impedance conversion, it is possible to set the output allocation for each of the ultrasonic transducers or the unit at any ratio, by changing a turn ratio or coupling coefficient of the transformer (e.g., by changing the insertion degree of a magnetic core).

By connecting an inductance in series to each of the ultrasonic transducers, which is approximately resonant to each of the ultrasonic transducers1aand1b, or by connecting an inductance in series, which is approximate resonant to a unit made up from a plurality of ultrasonic transducers connected in series or parallel, it is also possible to adjust the output allocation of each ultrasonic transducer or that of the unit. It is also possible to achieve an effect of reducing an invalid electric power by arranging the inductance. The inductance is smaller in size than that of the transformer for impedance conversion, and can be installed for each of the ultrasonic transducers1aand1bor for the unit overall.

The arrangement of ultrasonic transducers1aand1bis not limited to the cross-stripes pattern arrangement depicted inFIG. 1, and may be any other arrangement, e.g., a hexagonal close-packed structure or the like. Also, the shape of each of the ultrasonic transducers1aand1bis not limited to a round shape, as depicted inFIG. 1and can be freely designed in, e.g., square, rectangular or other patterns.

Next, referring toFIG. 3, another method for using the ultrasonic irradiation apparatus according to this embodiment shall be explained.

In the method described inFIG. 3, the ultrasonic irradiator3ais arranged so as to make contact with the living body6via the fluidic material layer7under the surface of a side of the sheet member2opposite to the ultrasonic transducers1aand1b. In this case, ultrasonic waves from the ultrasonic transducers1aand1bare output through the sheet member2and transferred to the living body6through the fluidic material layer7. Therefore, the sheet member2should be sound-conductive, and be composed of a material that does not contain substances which would reflect, and/or absorb ultrasonic waves, such as foam, gas or metal powder. For example, the material can be selected from among several types of rubber sheets such as, e.g., natural rubber, synthetic rubber or silicon rubber, etc. Materials containing substances which reflect and/or absorb ultrasonic waves, such as foamed rubber, foamed plastic, fabrics or textiles, etc., are not applicable in this situation.

It is preferable to arrange an air back layer8and an electromagnetic shielding layer9on the opposite upper surface of the ultrasonic transducers1aand1bon the sheet member2, and to arrange a protective layer10covering the ultrasonic transducers1aand1b, the air back layer8and the electromagnetic shielding layer9. The protective layer10is bonded to the sheet member2at a peripheral portion thereof and forms a bag-like construction. Further, the protective layer10contains the ultrasonic transducers1aand1b, the air back layer8and the electromagnetic shielding layer9in the back area between the sheet member2and itself. In this case, a joining member5(a pair of plane fasteners5aand5b) for joining the ultrasonic irradiator3ais arranged at the peripheral portion of the protective layer10.

The air back layer8can be made of a flexible sheet member composed of a foamed material such as foamed polyethylene or foamed rubber, etc. Further, the electromagnetic shielding layer9can be a flexible sheet member composed of a metal foil, a metal mesh or a conductive rubber, etc. In the ultrasonic irradiation apparatus depicted inFIG. 3, a plurality of electromagnetic shielding layers9are arranged overlapping each other so that each of them can freely slide.

As the protective layer10, several types of rubber sheet members, foamed rubber sheet members, such as expanded butylene or expanded silicon, fabrics or unwoven textiles, etc., may be applicable. The protective layer10is preferably waterproof for improving disinfection. It is not necessary to fill any special material on the inside of the protective layer10, and only air is sufficient. The air back layer8may also simply be an air layer, wherein air existing on the inside of the protective layer10may be used in place of the air back layer8.

In the ultrasonic irradiation apparatus depicted inFIG. 3, because the ultrasonic irradiator3acontacts with the living body6via a surface of the sheet member opposite to the ultrasonic transducers1aand1b, the ultrasonic irradiator3acan smoothly slide along the three-dimensionally curved surfaces of the living body6, and in the case of irradiating a human with ultrasonic waves, the contact feeling of the object can be improved. Because the ultrasonic transducers1aand1bare arranged on the sheet member2, on a side opposite to the living body6, the sheet member is also effective for protecting the ultrasonic transducers1aand1b.

Next, an ultrasonic irradiation apparatus according to a second embodiment of the present invention shall be explained with reference toFIG. 4throughFIG. 7.

In the ultrasonic irradiation apparatus, an ultrasonic irradiator3bis composed of a plurality of ultrasonic transducers1aand1binstalled on a net member11and arranged in a plane, as described inFIG. 4. The net member11is preferably composed of a material having flexibility and elasticity, wherein the net member11is formed of at least one type of material such as a string, a band, a spring, a chain and linked rods that are freely rotatable, and being fastened by knots12. The ultrasonic transducers1aand1bare arranged in a checkered pattern within the net member11and are adhered to the net member11. However, the arrangement of the ultrasonic transducers1aand1bis not limited to such a checkered pattern.

The strings for forming the net member11may be, for example, a synthetic resin string, a rubber line (a rubber string) or a plastic filament, etc. In the event a band is used, the band for forming the net member11may be composed of, for example, plastic, rubber, textile, fabric, very thin metal foil, a spring or a chain, etc. The net member11may be composed of two longitudinal strings13and two lateral strings14, as depicted inFIG. 5. The longitudinal string13and the lateral string14may be mutually knotted or bonded at an intersection15. In this case, the ultrasonic transducers1aand1bmay be adhered at their sides to the longitudinal string13and the lateral string14, or it may be applicable to form a surrounding groove along a side plane of the transducer (although not indicated in the figure), and to arrange the ultrasonic transducers1aand1bso as to be constrained by binding the longitudinal string13and the lateral string14to such a groove.

InFIG. 5, the longitudinal string13is shown by a dotted line and the lateral string14is shown by a solid line, in order to make the relationship between the longitudinal string13and the lateral string14clear. Also, the longitudinal string13and the lateral string14are depicted in the figure as shown apart from the ultrasonic transducers1aand1b, to better show the existence of the longitudinal strings13and the lateral strings14.

Further, in the ultrasonic irradiator3b, as shown inFIG. 6, the ultrasonic transducers1aand1bmay be installed on a plurality of bands16. The plurality of bands16are mutually connected by, e.g., a string (not shown), so that the ultrasonic transducers1aand1bare arranged in a hexagonal close-packed structure to thereby form the net member11.

In the ultrasonic irradiator3bas shown inFIG. 7, each of the ultrasonic transducers1aand1bmay be connected by two strings17, wherein the two strings17are mutually connected by, e.g., another string (not shown), so that the ultrasonic transducers1aand1bare arranged in a hexagonal close-packed structure to thereby form the net member11. The arrangement of the ultrasonic transducers1aand1bis not limited to a hexagonal close-packed structure.

In this case, the ultrasonic transducers1aand1bhave a surrounding groove18on the side and are constrained by the strings17, which are appropriately positioned. The two strings17are banded together by center holes of spacers19, which are arranged between the ultrasonic transducers1aand1a, or ultrasonic transducers1band1b.

In the ultrasonic irradiator3bshown inFIG. 7, it may be applicable to use, e.g., thin bands or thin springs in place of the strings17.

The ultrasonic irradiators3bshown inFIG. 4throughFIG. 7may have the same structure as the ultrasonic irradiator3a, except that the ultrasonic transducers1aand1bare installed on the net member11.

Next, referring toFIG. 8throughFIG. 10, an ultrasonic irradiation apparatus according to a third embodiment of the present invention shall be explained.

In the ultrasonic irradiation apparatus of this embodiment, a plurality of ultrasonic transducers1aand1b, composed of a driving electrode22formed on one plane of a flexible piezoelectric sheet member21and an opposed ground electrode23formed on the other plane of the flexible piezoelectric sheet member21, are arranged in a plane facing each other, for forming the ultrasonic irradiator3cas depicted inFIG. 8. In the ultrasonic irradiator3c, the ultrasonic transducers1aand the ultrasonic transducers1bare alternately arranged in each row of a tessellate arrangement (cross-stripes pattern).

As the flexible piezoelectric member21, a sheet of an organic piezoelectric material, like PVDF, or a sheet formed under an electric field from a plastic containing fine-grained piezoelectric ceramic, such as PZT, may be used. The driving electrode22and the opposed ground electrode23may be formed by a metal vapor deposition method on a surface of the flexible piezoelectric member21.

The flexible piezoelectric member21, when composed of the materials mentioned above, generally has flexibility, but is not sufficient in elasticity. Therefore, the flexible piezoelectric member21preferably has a plurality of linear recesses24on its surface. In the ultrasonic irradiator3cdepicted inFIG. 8, the linear recesses24are arranged in a straight pattern between the ultrasonic transducers1aand1b, and the plurality of linear recesses24are formed to be mutually parallel. Further, the linear recesses24are formed from one surface of the flexible piezoelectric member21toward the other surface, so as to penetrate the flexible piezoelectric member21in a thickness direction thereof.

Because the flexible piezoelectric member21includes linear recesses24in the ultrasonic irradiator3c, when deformed along the linear recesses24, the opening portions of the linear recesses24can be deformed into a ship shape, as a result of the upper edges of the linear recesses24moving apart, and it can also be easily deformed in a direction transverse to the linear recesses24. Thereby, the positions of the ultrasonic transducers1aand1b, provided in the ultrasonic irradiator3c, are mutually and flexibly deformable three-dimensionally.

The linear recesses24can be arranged between the ultrasonic transducers1aand1b, but are not limited to being in a linear shape, and need not necessarily be mutually in parallel. Moreover, they may be freely arranged, for example, the ultrasonic transducers1aand1bcan be arranged in a hexagonal close-packed structure, wherein the shape of the linear recesses24can be a curved waveform line winding between the ultrasonic transducers1aand1b. Further, the linear recesses24should be formed from one surface of the flexible piezoelectric member21toward the other surface, and can be non-penetrating with respect to the flexible piezoelectric member21. In the case that they do not penetrate the flexible piezoelectric member21, the linear recesses24may be arranged alternately on one surface and the other surface of the flexible piezoelectric member21.

Further, when the linear recesses24inFIG. 8are formed by penetrating the flexible piezoelectric member21from one surface to the other surface, a portion of the linear recesses24should not reach to a peripheral edge, so as not to divide the flexible piezoelectric member21into pieces. However, in the case where the linear recesses24do not penetrate through the thickness of the flexible piezoelectric member21, the linear recesses24may be arranged over the flexible piezoelectric member21from one peripheral edge to the opposed peripheral edge.

The ultrasonic irradiator3cshown inFIG. 8can have the same structure as the ultrasonic irradiator3a, except that the ultrasonic transducers1aand1bare formed from the flexible piezoelectric member21.

Next, referring toFIG. 9andFIG. 10, a method for using the ultrasonic irradiation apparatus shall be explained.

The ultrasonic irradiator3cshown inFIG. 9corresponds to the cross section IX-IX ofFIG. 8, whereas the ultrasonic irradiator3cshown inFIG. 10corresponds to the cross section X-X ofFIG. 8. The ultrasonic transducers1aand1bare actually composed of the driving electrode22and the opposed electrode23, and are arranged facing each other actually on both planes of the flexible piezoelectric member21, as depicted inFIG. 8. However, for convenience of illustration, they are shown inFIG. 9andFIG. 10as if the ultrasonic transducers were arranged on one plane only of the flexible piezoelectric member21, similar to the arrangement ofFIG. 1.

In the ultrasonic irradiation apparatus of the present embodiment, the ultrasonic irradiator3cis deformable in a direction along the linear recesses24as depicted inFIG. 9as a result of the flexibility of the flexible piezoelectric member24. The ultrasonic irradiator3cis also deformable in a direction transverse to the linear recesses24, as depicted inFIG. 10, because the opening portions of the linear recesses24can be changed into a ship shape by the upper edges of the linear recesses24moving apart.

Thereby, the ultrasonic irradiator3ccan be deformable three-dimensionally, as depicted inFIG. 9andFIG. 10, and the ultrasonic transducers1aand1bare fitted along the three-dimensional curved surfaces of the living body6such as the abdominal region, the thigh, the buttocks, the chin and so on. Then, a fluidic material layer7, namely an ultrasonic conducting medium, is to be placed between the living body6and the ultrasonic irradiator3c.

The ultrasonic irradiator3cirradiates with ultrasonic waves, in the manner indicated inFIG. 9andFIG. 10, and thereby induces lipolysis within the living body6or performs other processes.

The ultrasonic irradiator3cmay have a reinforcement material layer25on the side opposed to the living body6in the flexible piezoelectric member21. The reinforcement material layer25may be composed of a flexible electric shielding material, containing foams, or an air back layer for reflecting ultrasonic waves may also be used as the reinforcement material layer25.

The reinforcement material layer25prevents leakage of electric current to the living body, or prevents unnecessary external electromagnetic radiation, when a conductive layer is further formed on a surface opposed to the flexible piezoelectric member21and the conductive layer is kept at a ground electric potential. The reinforcement material layer25may further include a protective layer, composed of flexible and elastic foamed rubber, on the outside thereof.

The ultrasonic irradiator3cmay further have a protective layer (not shown), which is a living body contact sheet, provided between the surface opposed to the reinforcement material layer of the flexible piezoelectric member and the surface of the living body6. When the living body contact sheet is formed on the side of the living body6, it is composed of a sound-conducting material, such as a rubber sheet which is flexible and/or elastic and does not contain foams therein, so that ultrasonic waves are able to pass therethrough. The protective layer preferably is attached with, e.g., epoxy adhesives, so as not to contain air between the flexible piezoelectric member21and itself, at least within areas where it is in contact with the ultrasonic transducers1aand1b. in order to transmit ultrasonic waves successfully.

In each of the ultrasonic irradiators3a,3band3c, the ultrasonic transducers1aand1bmay be arranged in a cross-stripes or checkered pattern, as depicted inFIG. 1,FIG. 4andFIG. 5, or may be arranged in a hexagonal close-packed structure, as depicted inFIG. 6andFIG. 7. Further, in the tessellate (cross-stripes) arrangement, as depicted inFIG. 8, the ultrasonic transducers1aand the ultrasonic transducers1bmay be alternately arranged in each row of the tessellate arrangement.

This is preferable because, while moving the ultrasonic irradiator along surfaces of the living body6, a trajectory of the ultrasonic transducers1aand a trajectory of the ultrasonic transducers1bare overlapped irrespective of the driving direction, and thereby it is possible to eliminate a portion where the living body6is not irradiated with ultrasonic waves, based on arranging the ultrasonic transducers1aand1bin a hexagonal close-packed structure, as depicted inFIG. 6andFIG. 7.

In each of the figures, the ultrasonic transducers1aand1bare shown as circles in plan view, but they are not limited to circles and may be of any shape. In the ultrasonic irradiator3cdepicted inFIG. 8, the ultrasonic transducers1aand1bcan be easily formed in any shape, because the driving electrode22and the opposed electrode23forming the ultrasonic transducers1aand1bare formed on the surface of the flexible piezoelectric member21by means of a metal vapor deposition method.

Next, referring toFIG. 11andFIG. 12, an ultrasonic irradiation apparatus according to the fourth embodiment of the present invention shall be explained.

In the ultrasonic irradiation apparatus, the ultrasonic irradiator3ais installed on a surface of a flexible planar bag31containing a fluidic material layer7, as depicted inFIG. 11. The planar sheet (bag)31is composed of a soft material having both flexibility and elasticity, and contains a fluidic material32as an ultrasonic conducting medium.

The ultrasonic irradiation apparatus is placed in contact with an object, such as a living body6, via the fluidic material layer7on the surface of the planar bag31, and irradiates the object with ultrasonic waves via the planar bag by the ultrasonic irradiator3a.

Then, in the ultrasonic irradiation apparatus, it is possible to change the thickness of the planar bag31containing the fluidic material32, as well as to change the relative position between the object and the ultrasonic transducers1aand1binstalled in the ultrasonic irradiator3a. Thereby, the overlapping positions of the irradiated ultrasonic waves within the object may be changed and an excess or insufficient irradiation dose of ultrasonic waves at a specific area of the object can be avoided.

Further, the planar bag31can be removed from the ultrasonic irradiator3aand can be heated using a microwave oven or can be cooled using an electric refrigerator.

Because the planar bag31is flexible and contains the fluidic material32, the thickness or shape of the planar bag31can be changed. However, it is preferable that the planar bag31has a tube33at a side plane thereof, for channeling the inside and outside, wherein the tube33is connected to a pump (not shown). Thereby, the pump can supply the fluidic material32to the planar bag31through the tube33or discharge the fluidic material32from the planar bag31, and the thickness or shape of the planar bag31can be changed in a time sequence, by changing an amount of the fluidic material32contained in the planar bag31. The meaning of “changed in a time sequence” includes changing at any time-range, or randomly, and is not limited to changing at a predetermined time period exactly.

In the planar bag31, a partial deviation of the fluidic material32is caused inside the planar bag31, namely, a partial amount of the fluidic material32within the planar bag31is excessively increased, being affected by supplying or discharging the fluidic material32by a pump or though the function of the gravity, etc., wherein the distance between the object and the ultrasonic transducers1aand1binstalled in the ultrasonic irradiator3amay be partially varied to become long or short. Further, when the ultrasonic irradiator3aand the planar bag31are applied to a vertical surface of the living body6, the fluidic material32is gathered at a lower portion. As a result, the lower portion is expanded, the upper portion is narrowed, the surface of ultrasonic irradiator3ais greatly inclined, and it is difficult to contact curved surfaces of the living body6. As the remedy, the planar bag31has a connection member34, connecting an upper plane and a bottom plane within the planar bag31, for keeping the thickness of the planar bag31within a predetermined range.

The connection member34is composed of a cylindrical member35installed on an inner wall31aof the bottom plane in the planar bag31and a cylindrical member36installed on an inner wall31bof the upper plane in the planar bag31, wherein the cylindrical member36is inserted inside cylindrical member35, so as to slide along an inner wall of the cylindrical member35, as depicted in the enlarged view ofFIG. 12. The cylindrical member36has a claw member37on a side plane thereof, and includes a wide slit (not shown) in an axial direction of the cylinder. The member36having the claw37is inserted into the cylindrical member35from the upper side by elastic deformation of the cylindrical member36, and the claw37is restored and inserted in an opening38provided in a side wall of the cylinder35. Then, the claw member becomes slidingly engaged with the cylinder35. Sliding of the claw member37is limited at an upper end38aof the opening38, and thereby the thickness of the planar bag31is maintained within a predetermined range.

In the ultrasonic irradiation apparatus, the fluidic material32contained in the planar bag31may be a heatable or refrigeratable high specific heat material. In the case where the fluidic material32is a high specific heat material, the planar bag31may be detached and the fluidic material32in the detached planar bag31can be heated by, e.g., a microwave oven or cooled by, e.g., an electric refrigerator. It is possible to improve the effectiveness of ultrasonic irradiation to the object by irradiating the living body surface at a high temperature or a low temperature. Further, in the case where the object is a human, the tactile feeling of the person being irradiated can be improved by heating or cooling the fluidic material32, as has been described above.

For example, a mixture of water, propylene glycol and methylcellulose may be applicable as the heatable fluidic material32. For example, a mixture of water, hygroscopic polymer and polyhydric alcohol may be applicable as the refrigeratable fluidic material32.

In the ultrasonic irradiation apparatus, the ultrasonic irradiator3ais installed on the surface of the flexible planar bag31containing the fluidic material layer7, and can be freely installed or detached, as depicted inFIG. 11. However, the ultrasonic irradiator3amay also be integrated together with the surface of the planar bag31as a single unit. In this case, it should be arranged so that air can never exist between the planar bag31and the ultrasonic transducers1aand1b.

In the ultrasonic irradiation apparatus, the thickness of the planar bag31is kept within a predetermined range by the connection member34composed of the cylindrical members35and36, as shown inFIG. 12. However, alternatively, it is possible to tie the upper plane and the bottom plane at the corresponding position within a predetermined distance in the planar bag31using, e.g., flexible strips or string members.

In the ultrasonic irradiation apparatus, any one of the ultrasonic irradiators3bshown inFIG. 4throughFIG. 7, or the ultrasonic irradiator3cshown inFIG. 8, may be used instead of the ultrasonic irradiator3a.

Next, referring toFIG. 13throughFIG. 19, an ultrasonic irradiation apparatus according to a fifth embodiment of the present invention shall be explained.

In the ultrasonic irradiation apparatus, the ultrasonic irradiator3ais arranged inside of a flexible planar bag41. One plane of the flexible planar bag41is composed of a rigid member42, and the other opposed plane is composed of a soft material43having flexibility and elasticity, which serves as an acoustic window. Further, the planar bag41contains a fluidic material44as an ultrasonic conductive medium. The ultrasonic irradiator3ais arranged so as to be freely moved in parallel along a plane area42aof the rigid material42, or to be freely tilted in reference to the plane area42a, as indicated by the arrows inFIG. 13.

In the ultrasonic irradiation apparatus, the planar bag41is in contact with the living body6, via the fluidic material layer7, at the output window composed of the soft material43. Namely, at least one plane of the ultrasonic irradiator3a(the plane of the soft material43in the present embodiment) irradiates an object with ultrasonic waves via the flexible planar bag41. Because one plane of the planar bag41is composed of a rigid material42, the bag is easily handled by holding the side of the rigid material42.

Because the ultrasonic irradiator3ais arranged so as to be freely moved along the plane area42aof the rigid material42, or to be freely tilted with respect to the plane area42a, in the ultrasonic irradiation apparatus, the relative position between the object and the ultrasonic transducers1aand1bcan be changed. Therefore, an overlapping portion of the ultrasonic waves from the ultrasonic transducers1aand1bwith respect to the object is varied inside of the object, and an excessive or insufficient irradiation dose of ultrasonic waves at a specific area of the object can be avoided.

Further, because the ultrasonic irradiator3ais arranged so as to be freely moved along the plane area42aof the rigid material42, or to be freely tilted with respect to the plane area42a, in the ultrasonic irradiation apparatus, unevenness of the sonic field caused by an uneven arrangement of the ultrasonic transducers1aand1bis averaged. Therefore, a displacement range of movement or tilting of the ultrasonic irradiator3ais preferably of about the same distance as an interval between the ultrasonic transducers1aand1b.

In the ultrasonic irradiation apparatus, a soft material43is arranged along one plane of the planar bag41. The ultrasonic irradiation apparatus can make contact, via the soft material43, with an object having three-dimensionally curved surfaces such as the living body6. Therefore, the ultrasonic irradiator can be arranged inside of the planar bag41so that the plurality of ultrasonic transducers is installed on a surface of the rigid sheet, as shown by3ainFIG. 13.

Next, a structure by which the ultrasonic irradiator3ais freely movable along the plane area42aof the rigid material42, or is freely tilted with respect to the planar area42a, shall be explained.

In the case where the ultrasonic irradiator3ais arranged so as to be freely moved along the planar area42aof the rigid material42, the ultrasonic irradiator3ais suspended from the rigid material42by at least three support members45, so as to be flexibly movable, as shown inFIG. 14.

Then, one support member45is connected, via a watertight bearing46, to the rotating axis of a motor (not shown) which is arranged outside of the planar bag41, so as to be freely rotated. A disc47is installed at an end of the support member45, and a pin48, which is arranged at the peripheral portion so as to be project vertically downward, is inserted into a long narrow opening49aprovided in the ultrasonic irradiator3a. The opening49ahas a length corresponding to a diameter of the disc47.

As a result of this structure, because the pin48engages with the opening49aand moves the ultrasonic irradiator3ain accordance with rotation of the support member45, the ultrasonic irradiator3ais freely moved along the planar area42aof the rigid material42.

In this case, a guide member50may be arranged at a right-hand location inside of the rigid material42, for supporting an edge portion of the ultrasonic irradiator3a, in a direction crossing at a right angle with respect to the length direction of the opening49a. When a guide member50is provided also at the other left-hand side of the rigid material42, the ultrasonic irradiator3areciprocates in a direction crossing at a right angle to the length direction of the opening49abecause movement in the length direction of the opening49ais restricted by the guide member50.

Further, an insertion hole49binto which the pin48is inserted may be provided as shown inFIG. 15, in place of the long narrow opening49a. In this case, because the pin48is engaged in the insertion hole49band, in accordance with rotation of the support member45a, is driven to move the ultrasonic irradiator3a, the ultrasonic irradiator3aundergoes a circular motion along the periphery of the disc47.

Next, a case in which the ultrasonic irradiator3ais arranged so as to be freely tilted with respect to the planar area42aof the rigid material42shall be explained. The ultrasonic irradiator3ais supported approximately at the center of a side wall of the rigid material42by a freely rotatable support member51, as depicted inFIG. 16.

On the right-hand side wall of the rigid material42, a rotating axle52is installed and connected, via a watertight bearing (not shown) to a motor (also not shown) which is arranged on the outside of the planar bag41. A disc53is installed at one end of the rotating axix52, and a pin54, arranged at the peripheral edge portion of the disc53and projecting frontward, is inserted into a long narrow slit55arranged in a side plane of the ultrasonic irradiator3a. The slit55has a length corresponding to a diameter of the disc53.

Based on this structure, because the pin54is engaged with the slit55and is driven to move an end of the ultrasonic irradiator3awhere the slit55has been provided, in accordance with rotation of the rotating axis52, the ultrasonic irradiator3amoves up and down in a range corresponding to the diameter of the disc53. Then, because the ultrasonic irradiator3ahas been supported on a side wall of the rigid material42by the support member51, which is freely rotatable, the ultrasonic irradiator3acan be freely tilted with respect to the plane area42aof the rigid material42, with the support member51serving as an axis.

The ultrasonic irradiator3amay be driven by a linear motor, a water-powered piston, an electromagnetic moving solenoid or water-powered motor, etc., instead of using the structure shown inFIG. 14throughFIG. 16. Thereby, the ultrasonic irradiator3amay be arranged so as to be freely moved along the plane area42aof the rigid material42, or to be freely tilted with respect to the plane area42aof the rigid material42.

Further, in the case where the ultrasonic irradiator3ais arranged so as to be freely tilted with respect to the plane area42aof the rigid material42, it is preferable to use an ultrasonic irradiator3din which the ultrasonic irradiator3ais divided into a unit of subdivided rows, each row having a plurality of ultrasonic transducers1aand1bas shown inFIG. 17. In the ultrasonic irradiator3d, the tilting angle with respect to the plane area42aof the rigid material42can be made larger than that of the ultrasonic irradiator3a, and thereby a change of position, where the ultrasonic waves irradiated from the ultrasonic transducers1aand1btoward the object overlap within the object, can be made larger.

In this case, the same structures52,53,54as shown inFIG. 16can be provided for the ultrasonic irradiator3d, located at a right-hand side of the planar bag41. An end of an ultrasonic irradiator row3dand an edge of another ultrasonic irradiator row3dare connected by a connection member56. Thereby, in accordance with tilting of the ultrasonic irradiator row3d, which is engaged with the slit55, the pin54arranged in the disc53can drive the other ultrasonic irradiator rows3dsimultaneously, to tilt them with respect to the plane area42aof the rigid material42.

InFIG. 14toFIG. 16, and inFIG. 18, the ultrasonic transducers1aand1bhave not been shown for simplicity in illustration.

In the ultrasonic irradiation apparatus of the present embodiment, an plane of the planar bag41, which is opposed to the living body6, may be composed of a flexible material instead of the rigid material42. It is preferable that the flexible material has a fine flexibility in one direction, but, when deformed in one direction, it becomes difficult to be deformed in a direction transverse to the deformation.

Therefore, when using a flexible material57being fairly hard, instead of the rigid material42, the flexible material57is slightly hard and is bent so as to form waves, wherein the bent portions are constructed of linear recesses58, as depicted inFIG. 19. The top upper open portions of the linear recesses58can be deformed apart, and thereby the planar bag41also is deformed in a direction transverse to the linear recesses58. In order to conform to curved surfaces of a living body, an output window composed of the soft material43is deformed in the direction of the linear recesses58. In this case, the range at which the output window composed of the soft material43becomes deformed is smaller, and the thickness of the fluidic material44may also be smaller and lighter than in the case ofFIG. 17.

Thus, the planar bag41can be deformed three-dimensionally, and the ultrasonic transducers1aand1binstalled inside of the ultrasonic irradiator3acan be arranged to conform to the three-dimensionally curved surfaces of the living body6.

In the structure shown inFIG. 19, it is preferable that the irradiator3abe freely movable underneath the recesses and in parallel to the living body6, as shown by the arrow, in order to change its position for averaging, wherein the ultrasonic waves emitted from the ultrasonic transducers1aand1btoward the object overlap within the object, and are uneven due to the sonic field, based on the arrangement of the ultrasonic transducers1aand1b. For this purpose, a magnetic material can be mixed into or attached to the flexible sheet2of the ultrasonic irradiator3a, and magnets can be attached at the bottom of the linear recesses58, to keep them close while moving.

In the ultrasonic irradiation apparatus of the present embodiment, for the fluidic material44contained in the planar bag41, the same fluidic material as the fluidic material32contained in the planar bag31shown inFIG. 11, composed of a heatable and/or refrigeratable high specific heat material, can be used. Therefore, in the ultrasonic irradiation apparatus, the effectiveness of irradiating an object with ultrasonic waves can be enhanced, or the feeling of the object when the object is a human can be improved, by using a fluidic material42that has been previously heated by, e.g., a microwave oven or cooled by an electric refrigerator.

In the ultrasonic irradiation apparatus, instead of the ultrasonic irradiator3a, the ultrasonic irradiator3bshown inFIG. 4throughFIG. 7, or the ultrasonic irradiator3cshown inFIG. 8, can be used.

Next, referring toFIG. 20andFIG. 21, an ultrasonic irradiation apparatus according to the sixth embodiment of the present invention shall be explained. The ultrasonic transducers1aand1bare not shown inFIG. 20andFIG. 21, for simplicity of illustration.

The ultrasonic irradiation apparatus has a band holding member61, arranged so that the ultrasonic irradiator3ais easily installed, via the band holding member61, on a region of the living body6, such as the abdominal region or thigh, as depicted inFIG. 20(a) orFIG. 20(b). The band holding member61is joined to a periphery of the ultrasonic irradiator3a, wherein the band holding member61is capable of being wound around the living body6, and is tightly fixed at an appropriate position on the body by a pair of plane fasteners62aand62b, as depicted inFIG. 20(a).

The band holding member61can be arranged so as to cover the ultrasonic irradiator3a, as depicted inFIG. 20(b). In this case, the ultrasonic irradiator3amay be integrally fixed to the band holding member61, or may be arranged so as to be optionally detached from the band holding member61by a pair of plane fasteners (not shown). Further, the ultrasonic irradiator3acan simply be held in the band member61merely by friction between the band holding member61and itself, without having any means for fixing the ultrasonic irradiator3ato the band holding member61.

Because the ultrasonic irradiator3ais fitted to the living body6via the band holding member61in the ultrasonic irradiation apparatus, the band holding member61greatly assists in reducing the load on an operator.

Further, it is preferable that the ultrasonic irradiator3abe arranged so as to contact the living body6at the side of the flexible sheet2, as depicted inFIG. 3. Further, the ultrasonic irradiator3acan be arranged to have a protective layer on the non-output side thereof, and further, a layer of a material such as a fluorocarbon, having a small coefficient of friction, can be coated on the surface. Thereby, the ultrasonic irradiator3ais arranged to be able to slide against the band holding member61while the ultrasonic irradiator3ais arranged in contact with the living body6via the fluidic material layer7, and is able to slide against the living body6as well. Therefore, the ultrasonic irradiator3acan be moved along the living body6while positioned in an intervening manner between the band installation member61and the living body6.

Further, the ultrasonic irradiation apparatus preferably has the structure shown inFIG. 21, so as to be freely movable along the living body6without being subject to friction of the band holding member61, namely, being positioned so as not to intervene between the band and the living body6.

The ultrasonic irradiation apparatus depicted inFIG. 21is joined to an edge of the ultrasonic irradiator3awithout being covered by the band holding member61. Rather, a band holding member63is provided, which is to be wound around the living body6, and winding devices66aand66bare provided that wind strings65connected to the ultrasonic irradiator3aby means of pulleys64driven by a motor (not shown), while additional band holding members67aand67bare provided to be wound around the living body6, for fixing the overall assembly. Each of the band members67aand67bhas a pair of plane fasteners (not shown) at an edge thereof, and can be tightly fixed to the living body6at an appropriate position by means of such plane fasteners.

In the ultrasonic irradiation apparatus depicted inFIG. 21, the ultrasonic irradiation apparatus3acan be reciprocated along surfaces of the living body6, in the length direction of the band holding member63, by using a jelly as a lubricant, and by alternatively driving the winding devices66aand66bwhile the ultrasonic irradiation apparatus is fitted to the living body6by the band holding members63,67aand67b.

In the ultrasonic irradiation apparatus shown inFIG. 21, the ultrasonic irradiation apparatus3ais freely reciprocated along the length direction of the band installation member63. However, it may also be arranged so as to be freely reciprocated in the width direction of the band installation member63.

In the ultrasonic irradiation apparatus, it is preferable that the band holding members61,63,67aand67bbe composed of a flexible material capable of absorbing or dissipating sweat. As this material, for example, a belt composed of fabric or textile, or a fiber net, may be utilized.

Further, in the ultrasonic irradiation apparatus of present embodiment, the ultrasonic irradiator3bshown inFIG. 4throughFIG. 7, the ultrasonic irradiator3cshown inFIG. 8, or the planar bag41having at least one flexible plane, as shown inFIG. 13throughFIG. 19, can be used instead of the ultrasonic irradiator3a.

INDUSTRIAL APPLICABILITY

The present invention is applicable, e.g., for use in irradiating a living body with ultrasonic waves for lipolysis within the living body, and for acceleration of the bloodstream and the infiltration of medicines.