JPH0947458A - Ultrasonic therapeupic device and applicator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent reduction in ultrasonic wave transmitting efficiency and leakage of a coupling liquid by a burst of a water bag film by forming a water bag into which an ultrasonic wave is introduced in a multilayer structure by interposing the coupling liquid between it and an ultrasonic wave generating source. SOLUTION: A water bag 5 to be removably installed in a packing material 6 of an applicator 1 by a ring 8, is formed in a multilayer structure by layering plural films. These films are made nonextensible-noncontractibe so as not to shut up bubbles inside like silicone rubber, and have heat resistance, and are higher in dynamic strength than silicone rubber in the same thickness, and do not hinder passing of an ultrasonic wave. For example, polyvinylidene chloride or the like is used. An O ring 7 to secure watertightness is sandwiched between the ring 8 and the packing material 6, and a coupling liquid 4 to introduce an ultrasonic wave generated by an ultrasonic wave generating source 2 into the body of an examine 3 without causing a loss, is sealed between the ultrasonic wave generating source 2 and the water bag 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic therapeutic apparatus and an applicator for irradiating ultrasonic waves inside the body for treatment.

[0002]

2. Description of the Related Art In recent years, a stone crushing device for non-invasively crushing stones by intermittently irradiating strong ultrasonic pulses from outside the body has been put into practical use for the treatment of calculi disease, and has attracted attention. In addition, a hyperthermia treatment, which treats a tumor such as a benign prostatic hyperplasia by irradiating the affected area inside and outside the body with electromagnetic waves or ultrasonic waves (hyperthermia), is performed as a treatment method that is relatively less invasive. . This takes advantage of the fact that the tumor tissue is relatively more vulnerable to heat than normal tissue, and
It is a treatment method in which only tumor cells are destroyed by heating above ℃. In addition, heat treatment that heats the affected area to a temperature of 60 ° C. or higher and causes thermal denaturation of pathological tissues has come to the attention,
As disclosed in Japanese Patent Application Laid-Open No. 61-013956, strong ultrasonic waves generated outside the body by a piezo element are focused on a treatment site inside the body, and cancer is generated by heat generated by absorption of ultrasonic energy of tissue. Devices for heat treatment are being researched and developed.

The calculus breaking device and the ultrasonic thermotherapy device are collectively referred to as an ultrasonic therapy device. When using a piezo element as an ultrasonic wave source in an ultrasonic therapy device, there is no consumable item, the ultrasonic intensity can be controlled arbitrarily, and the focus position is controlled by controlling the drive waveform applied to multiple piezo elements. It has excellent advantages such as being possible (see JP-A-60-145131 and US Pat. No. 4,526,168).

An ultrasonic therapy device has an applicator as a main component. The applicator encloses a coupling liquid in a water bag membrane in order to introduce ultrasonic waves generated by arranging multiple piezo elements into a spherical shell shape and introduce the ultrasonic waves generated by the piezo elements into the living body with little loss. (See JP-A-60-145131 and JP-A-02-246961). As the material of the water bag membrane, silicone rubber having excellent heat resistance and elasticity is often used.

[0005]

In the ultrasonic therapy device,
Strong ultrasonic waves with extremely high energy generated by driving the piezo element at a high voltage are used. Therefore, when there are obstacles such as air bubbles and bones on the propagation path of ultrasonic waves, the ultrasonic waves are absorbed and scattered at those portions, and heat generation and cavitation occur. Therefore, the coupling between the water bag membrane and the body surface becomes a problem. An ultrasonic jelly is used for this coupling. That is, the water bag membrane is brought into contact with the body surface via the ultrasonic jelly. If air bubbles are mixed in the ultrasonic jelly, heat is generated in the air bubbles. Due to this heat generation, if the water bag membrane is damaged, the coupling liquid leaks, or the portion of the membrane that corresponds to the ultrasonic path is denatured, the ultrasonic wave transmission efficiency will drop. In the silicone rubber that is the material for the water bag membrane, bubbles due to cavitation penetrate into the silicone rubber,
It is confined as it is, and the propagation efficiency of ultrasonic waves is significantly reduced.

It is an object of the present invention to prevent air bubbles due to cavitation or the like from being trapped in a water bag membrane and lowering the propagation efficiency of ultrasonic waves. A super-water bag membrane that has sufficient mechanical strength to prevent leakage and has a certain degree of flexibility so that it can be processed into a bag shape and can be adhered to uneven body surfaces. A sonic therapy device and an applicator.

[0007]

According to the present invention, ultrasonic waves generated by an ultrasonic wave generation source are introduced into a subject through a coupling liquid sealed between the ultrasonic wave generation source and a water bag. In the ultrasonic treatment apparatus for treating an affected area in the subject, the water bag is formed in a multi-layer structure.

Further, according to the present invention, a coupling liquid is sealed between an ultrasonic wave generating source for generating an ultrasonic wave for treating an affected area in a subject and the ultrasonic wave generating source to generate the ultrasonic wave. In an applicator having a water bag for introducing the ultrasonic waves generated by a source into the subject through the coupling liquid, the water bag is formed in a multi-layer structure.

By forming the water bag in a multi-layered structure, the water bag becomes more flexible than when the water bag is formed as a single layer film with the same material and the same thickness. This facilitates bending, facilitates processing into a bag shape, and improves adhesion to the patient's body surface. Further, even when the film is damaged by the influence of cavitation or heat, if it is a single-layer film, air bubbles will be trapped in the material, and if it is thin, it will break and the coupling liquid will leak, but the present invention If the water bag has a multi-layered structure as described above, one sheet is torn and no bubbles remain.
Also, if the water bag has a multi-layer structure, damage will stop at each layer,
Since it does not easily spread to all layers, the possibility of complete breakage and leakage of coupling liquid is reduced.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of an ultrasonic therapeutic apparatus according to one embodiment, and FIG. 2 shows a sectional structure of the applicator shown in FIG. An applicator 1 for generating a therapeutic ultrasonic wave and introducing it into a living body has an ultrasonic wave generating source 2 in which a plurality of piezoelectric elements are arranged in a spherical shell shape. The ultrasonic wave generated from each piezo element is focused on the focal point 10. Focus 10
Is geometrically determined according to the curvature of the spherical shell shape. The ultrasonic wave generation source 2 is fixed to the backing material 6. The backing material 6 has a structure that promotes cooling of the air backing or the piezoelectric element. The water bag 5 is removably attached to the backing material 6 by a ring 8. O between the ring 8 and the backing material 6 for watertightness
The ring 7 is sandwiched. Ultrasonic source 2 and water bag 5
And a coupling liquid 4 for introducing the ultrasonic waves generated by the ultrasonic wave generation source 2 into the subject 3 with little loss.
Is enclosed.

The drive circuit 12 drives a plurality of piezoelectric elements of the ultrasonic wave generation source 2 in order to generate ultrasonic waves all at once. The applicator 1 is movably supported by a mechanical arm 14. The movement of the applicator 1 is performed electrically under the control of the control circuit 13 or manually.

An insertion hole 16 is formed in the central portion of the ultrasonic wave generation source 2, and the ultrasonic probe 15 is slidably and rotatably inserted therein so that the ultrasonic probe 15 can move toward and away from the focal point 10. . The sliding and rotating movements of the ultrasonic probe 15 are controlled by the probe position control circuit 17. The ultrasonic diagnostic apparatus 18 drives the ultrasonic probe 15 to obtain an ultrasonic image near the focus 10.

Although not shown, the ultrasonic diagnostic apparatus 18 has a C
The PU is configured as follows as a control center of the entire system. An ultrasonic wave transmitter and an ultrasonic wave receiver are connected to the ultrasonic probe 15. The ultrasonic transmission unit has a pulse generator, a transmission delay circuit, and a pulser. The pulse generator has, for example, a rate frequency fr of 5 KHz (cycle: 1 / fr)
The rate pulse is repeatedly generated at. This rate pulse is distributed to the number of channels and sent to the transmission delay circuit.
The transmission delay circuit focuses each ultrasonic wave into a beam and gives each rate pulse a delay time necessary for determining the transmission directivity. The pulsar applies a voltage pulse to the probe 15 for each channel at the timing of receiving the rate pulse from the transmission delay circuit. Thereby, the ultrasonic beam is transmitted to the subject. The reflected wave reflected by the discontinuity surface of the acoustic impedance in the subject is received by the ultrasonic wave reception unit via the probe 15. The ultrasonic wave reception unit has a preamplifier, a reception delay circuit, and an adder. The received signal is amplified by the preamplifier for each channel, given a delay time necessary for determining the reception directivity by the reception delay circuit, and added by the adder. By this addition, an echo signal in which the reflection component from the direction corresponding to the transmission directivity and the reception directivity is emphasized is obtained. The echo signal is sent to the receiver section. The receiver section includes a logarithmic amplifier, an envelope detection circuit, and an analog / digital converter (A / D). The logarithmic amplifier is
The echo signal is logarithmically amplified. The envelope detection circuit detects the envelope of the output signal from the logarithmic amplifier. This detected signal is digitized through an analog-digital converter and output as B-mode image data. This B-mode image data is a digital scan converter (DS
It is sent to the display unit via C) and is displayed as a B-mode image in a light and shade.

The operator confirms the position of the affected part 11 such as a tumor while looking at this B-mode image, and sets the focus 10 to the affected part 11
It is possible to position the patient, make a treatment plan, and check the progress of the treatment during the treatment. After the focus 10 is aligned with the affected area 11, the ultrasonic wave generation source 2 is driven to generate ultrasonic waves, and the affected area 11 present at the focus 10 is treated.

During treatment, the applicator 1 is set on the patient 3 fixed on the treatment table 19, and the water bag 5 is brought into close contact with the body surface of the patient 3 by the ultrasonic jelly 9.

FIG. 3 shows a sectional structure of the water bag 5. Conventionally, as shown in FIG. 3A, the water bag has been formed of a single layer film of silicon rubber or the like having a thickness of about 0.01 mm. On the other hand, in the present invention, as shown in FIG. 3B, the water bag 5 has a multi-layer structure in which a plurality of films are laminated. The material of the film is non-stretchable and heat-resistant so that it does not trap air bubbles in it like silicon rubber, and has the same mechanical strength as silicone rubber at the same thickness, and it does not pass ultrasonic waves. Not disturbing, for example, polyvinylidene chloride (PVDC), PVC (polyvinyl chloride), LDPE (low density polyethylene), L-LDP
A film of each copolymer of a chlorinated resin material such as E (linear low density polyethylene) or HDPE (high density polyethylene) or a film of a fluororesin such as polytetrafluoroethylene (PTFE) is adopted. This kind of film has no elasticity and is hard, so that it can be processed into a bag shape or can be adhered to an uneven body surface, in order to obtain some flexibility, for example, about 0.01 mm. Need to be thin. However, when a thin film of this kind is formed, the mechanical strength cannot be maintained, and there is a risk that the sealed coupling liquid leaks, so it is particularly effective to use a multilayer structure as in the present invention. is there. Furthermore, by adopting a material having high transparency for the film, it is possible to obtain the effect of making it easier to find the presence of bubbles and impurities in the coupling liquid. Since the film made of the above material is not stretchable, it cannot be used by inflating it like silicon rubber. Therefore, by using it in the device of the bellows 23 as shown in FIG. It is preferable to adjust the distance of the ultrasonic wave generation source 2 to the affected area 11 by increasing or decreasing the amount. The bellows may be received separately, or the film itself may be formed into a bellows shape.

A plurality of films constituting the multi-layer structure of the water bag 5 are adhered in a vacuum state so as not to prevent passage of ultrasonic waves and trap air bubbles that cause cavitation. In order to expel the air bubbles trapped between the films, filling the degassed liquid, for example, degassed water between the films, as shown by the diagonal lines in FIG. 3 (e), is to improve the yield. Is preferred. In addition, it is more preferable to fill a viscous liquid between the films instead of deaerated water from the viewpoint of suppressing the occurrence of cavitation. A gel-like substance such as ultrasonic jelly is used as the viscous liquid. Of course, it is a minimum condition that the degassed liquid or the viscous liquid is harmless. Also, FIG.
As shown in (f), a locally degassed liquid or a viscous liquid may be filled between the films to process the water bag 5 into a rounded shape.

The thickness of each layer (each film) constituting the water bag 5 or the total thickness of the water bag 5 is set in order to suppress the scattering of ultrasonic waves and the energy loss before reaching the affected area. It is formed at λ / 2 or less depending on the wavelength λ of the therapeutic ultrasonic wave. For example, one film has a thickness of about 0.01 mm. In this case, the water bag 5 is formed in a multi-layer structure in which five films are laminated, and has a total thickness of 0.05 mm.

By thus forming the water bag 5 in a multi-layered structure with a plurality of films, the water bag 5 has higher flexibility than the water bag 5 formed as a single-layer film with the same material and the same thickness. This facilitates bending, facilitates processing into a bag shape, and improves adhesion to the patient's body surface. Further, even when the film is damaged by the influence of cavitation or heat, in the case of a single-layer film, air bubbles are trapped in the material as shown in FIG. Although it may leak, if the water bag 5 has a multi-layer structure as in the present invention, one sheet is broken as shown in FIG. Further, if the water bag 5 has a multi-layered structure, the damage stops at each film and does not easily spread to all the films, so that the possibility of complete breakage and leakage of the coupling liquid is reduced.

Incidentally, as shown in FIG. 5, when a plurality of piezo elements constituting the ultrasonic wave generating source 2'are arranged in a plane and the focus 10 can be formed at an arbitrary depth by delay control, A coupling liquid container 24 having a shape may be used. As shown in FIG. 5, the phased array type ultrasonic wave generation source 2 ′ is fixed to the backing material 6 ′. The backing material 6'includes a removable coupling liquid container 2
4 is attached. Furthermore, the coupling container 24
A water bag 5 ′ is attached to the opening 25 of the device by a ring 8. An O-ring 7 is sandwiched between the water bag 5'and the coupling liquid container 24 'to keep it watertight. The coupling container 24 is a fitting type in the backing 6 ', and containers having different heights may be used according to the depth of the affected area. For example, as shown in FIG. 5, the coupling liquid 4 is put in and taken out by an injection hole 26 and a discharge hole 27 provided in the backing material 6 ′.

The present invention is not limited to the above-mentioned embodiments, but can be modified in various ways. INDUSTRIAL APPLICABILITY The present invention can be applied to various ultrasonic treatment devices such as a calculus breaking device, a thermotherapy device, and a heat treatment device.

[0022]

According to the present invention, the ultrasonic wave generated by the ultrasonic wave generation source is introduced into the object through the coupling liquid sealed between the ultrasonic wave generation source and the water bag. In the ultrasonic treatment apparatus for treating the affected part inside, the water bag is formed in a multi-layered structure.

Further, according to the present invention, a coupling liquid is sealed between an ultrasonic wave generating source for generating an ultrasonic wave for treating an affected area in a subject, and the ultrasonic wave generating source. In an applicator having a water bag for introducing the ultrasonic waves generated by a source into the subject through the coupling liquid, the water bag is formed in a multi-layer structure.

By forming the water bag in a multi-layered structure, the water bag becomes more flexible than when the water bag is formed as a single layer film with the same material and the same thickness. This facilitates bending, facilitates processing into a bag shape, and improves adhesion to the patient's body surface. Further, even when the film is damaged by the influence of cavitation or heat, if it is a single-layer film, air bubbles will be trapped in the material, and if it is thin, it will break and the coupling liquid will leak, but the present invention If the water bag has a multi-layered structure as described above, one sheet is torn and no bubbles remain.
Also, if the water bag has a multi-layer structure, damage will stop at each layer,
Since it does not easily spread to all layers, the possibility of complete breakage and leakage of coupling liquid is reduced.

[Brief description of drawings]

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

FIG. 2 is a sectional structural view of the applicator of FIG.

FIG. 3 is a cross-sectional structure of the water bag of FIG. 2 and an explanatory view of effects.

FIG. 4 is a cross-sectional structural view of an applicator having a water bag formed in a bellows structure.

FIG. 5 is a cross-sectional structure diagram of an applicator that employs a coupling liquid container.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Applicator, 2 ... Ultrasonic source, 3 ... Test object, 4 ... Coupling liquid, 5 ... Water bag, 6 ... Backing material, 7 ... O ring, 8 ... Ring, 9 ... Ultrasonic jelly, 10 ... Focus, 11 ... Affected part, 12 ... Drive circuit, 13 ... Control circuit, 14 ... Mechanical arm, 15 ... Ultrasonic probe, 16 ... Probe insertion hole, 17 ... Probe position control circuit, 18 ... Ultrasonic diagnostic device, 19 ... Treatment Stand.

Claims (8)

[Claims] 1. An ultrasonic wave generated by an ultrasonic wave generation source is introduced into a subject through a coupling liquid sealed between the ultrasonic wave generation source and a water bag, and an affected area in the subject is detected. In the ultrasonic treatment apparatus for treatment, the water bag is formed in a multi-layered structure. 2. The ultrasonic therapeutic apparatus according to claim 1, wherein the water bag is formed so that each layer has a thickness of λ / 2 or less, where λ is the wavelength of the ultrasonic wave. 3. The ultrasonic therapeutic apparatus according to claim 1, wherein the water bag is made of a non-stretchable material. 4. The ultrasonic therapeutic apparatus according to claim 1, wherein the water bag is filled with degassed liquid between layers. 5. A coupling liquid is sealed between an ultrasonic wave generation source for generating ultrasonic waves for treating an affected area in a subject and the ultrasonic wave generation source, and the ultrasonic wave is generated by the ultrasonic wave generation source. An applicator having a water bag for introducing the ultrasonic waves into the subject through the coupling liquid, wherein the water bag is formed in a multi-layer structure. 6. The applicator according to claim 5, wherein the water bag is formed so that each layer has a thickness of λ / 2 or less, where λ is the wavelength of the ultrasonic wave. 7. The applicator according to claim 5, wherein the water bag is made of a non-stretchable material. 8. The applicator according to claim 5, wherein the water bag is filled with degassed liquid between layers.