JP2000126197A - Ultrasonic therapeutic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the optimum irradiation so as not to damage a caution area by specifying a positional relationship between the positions of an ultrasonic focus and a caution area to determine making power and irradiation time according to a function of an intensity value at the p positions of the ultrasonic focus and the caution area as given based on the positional relationship. SOLUTION: In the treatment, an applicator is placed on a patient 3 laid on the side and a coupling film 5 thereof is kept in contact with a body surface 6 through an ultrasonic gel or the like. Then, a tomographic image containing an affected part 7 is reconstructed by an ultrasonic diagnostic instrument 16 based on a reflected wave signal from the patient 3 obtained by an ultrasonic probe 15 and the position of an ultrasonic focus 8 of a piezoelectric element 2 is displayed on a CRT 18 in superimposition on the reconstructed image through a DSC 17 to adjust the applicator for positioning, Thereafter, the position of the body surface of the patient and other positions of caution areas are specified to determine the making power and irradiation time according to a function of intensity values at the focus position and the caution area positions based on the positions thereby controlling the excitation of the piezoelectric element 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic treatment apparatus for treating a tumor or the like in a living body using ultrasonic waves.

[0002]

2. Description of the Related Art In recent years, MIT (Minimally I
The flow of minimally invasive treatment called nvasive treatment has attracted attention in various medical fields. One example is the practical use of a calculus crushing device that irradiates intense ultrasonic waves from outside the body to treat calculus and non-invasively crushes and treats calculus. This has greatly changed the method of treating urinary calculus.

[0003] As a system of a powerful ultrasonic generator used in this calculus breaking device, there are an underwater discharge system, an electromagnetic induction system and a micro explosion system. Piezo method and the like are available. In particular, in a device using a piezo-type high-intensity ultrasonic wave source, although the pressure of the high-intensity ultrasonic wave is low, the high-intensity ultrasonic pressure can be arbitrarily controlled with a small focus and no consumables. There is an excellent advantage that the focus position can be arbitrarily controlled by controlling the phase of the driving voltage applied to the piezo element (JP-A-60-145131, US Pat. No. 4,526,168).

[0004] In particular, in the case of malignant neoplasms, so-called cancers, since most of the treatments rely on surgical techniques, the functions and appearance of the organs are extremely greatly impaired in many cases. . For this reason, even if the life is prolonged, a large burden remains on the patient.
There is a strong demand for the development of a less invasive treatment method (apparatus) in consideration of (Quality Of Life).

Conventionally, surgery, radiation therapy and chemotherapy (anticancer drugs) are the three major therapies for cancer. In the course of the above-mentioned minimally invasive treatment, heat has been used as one of new cancer treatment techniques. Treatments have come to the fore. A prominent example is hyperthermia treatment.

[0006] Hyperthermia treatment uses the difference in the thermal sensitivity between tumor tissue and normal tissue to cure the affected area between 42.5 and 42.5.
This is a treatment method in which only cancer cells are selectively killed by heating and maintaining the temperature at 3 ° C. or higher.

As a method of heating, a method using an electromagnetic wave such as a microwave has been preceded, but it is difficult to selectively heat a deep tumor by this method due to the electrical characteristics of a living body. Good results cannot be expected for tumors with a depth of 5 cm or more.

In recent years, a microwave / RF wave antenna has been inserted into a diseased part intraoperatively or laparoscopically or percutaneously in order to improve the inaccessibility of electromagnetic wave energy, and the temperature around the antenna has been increased to 60 ° C. or more. A new therapeutic method that has improved the local therapeutic effect by heating at a high temperature has been spotlighted (Isota et al .: J. Microwave Surgery).

[0009] However, since this treatment also requires puncture of an organ, it is less invasive than conventional surgical treatment, but also has a problem that puncture has side effects such as bleeding and dissemination (metastasis).

In order to solve the problems of these conventional methods, a method has been proposed in which a deep tumor is heat-treated from outside the body by using ultrasonic energy having a good energy focusing property and a high degree of penetration (see, for example, Japanese Patent Application Laid-Open No. H11-157556). JP-A-61-13955).

Further, the above-mentioned heating treatment method is further advanced, and the ultrasonic wave generated by the piezo element is sharply focused on the affected part to heat the tumor part to 80 ° C. or more, and the tumor tissue is instantaneously thermally denatured and necrotic. Such treatments are also being considered (G. Val)
lancien et. al: Progress in
Urol. 1991, 1, 84-88, U.S. Pat. No. 5,150,711).

In this treatment method, unlike conventional hyperthermia, an ultrasonic wave of very high intensity (several hundreds to several thousand W / cm ² ) is applied to a localized area near the focal point.
Only a small area near the focal point is instantaneously heat denatured and moribund.

However, since it is necessary to cauterize the entire affected area while scanning a small focus, accurate positioning of the focus is considered to be very important. As one solution to this, Japanese Patent Application Laid-Open No. 5-253192 has already known a technique of measuring an intraoperative non-invasive sensitivity distribution image using an MRI chemical shift to measure an intraoperative heating point.

Further, even in a system using only an ultrasonic wave, Japanese Patent No. 1851304, Japanese Patent No. 1821772, Japanese Patent No.
No. 765452 discloses a method of detecting a reflected wave of a therapeutic ultrasonic wave from a focal region and displaying the detected ultrasonic wave on an ultrasonic image.

[0015]

As described above, in the conventional ultrasonic therapy apparatus, since the focus is very sharply focused and the ultrasonic energy is strongly concentrated, the ultrasonic intensity more than necessary in the focal area, that is, There is a problem that heat is generated.

If the intensity of the ultrasonic wave in the focal region is reduced without taking the irradiation time into consideration, there is a problem that the entire treatment time increases and the treatment becomes unrealistic. SUMMARY OF THE INVENTION It is an object of the present invention to provide a highly safe ultrasonic therapy apparatus capable of inducing a desired thermal denaturation in a focal tissue and realizing an optimum irradiation without damaging an attention area.

[0017]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an ultrasonic treatment apparatus which focuses an ultrasonic wave emitted from an ultrasonic wave source on a treatment site of a subject to perform treatment. Means for giving a positional relationship between the sound wave focal position and the attention area position, and irradiation conditions for determining the applied power and the irradiation time according to a function of the intensity values at the ultrasonic focus position and the attention area position given based on the positional relation. Determining means.

The irradiating condition determining means may store the defocusing condition and the attention area non-denaturing condition in a memory in advance, and calculate and determine the irradiating condition by retrieving data from the memory. And

The present invention further comprises means for calculating and storing the defocusing condition and the attention area non-denaturing condition prior to the treatment, so that the treatment can be performed based on the stored focus degeneration condition and the attention area non-denaturing condition. Is calculated and determined.

Further, the apparatus is further characterized by further comprising means for calculating a required interval time for the set input power and irradiation time. In the ultrasonic therapy apparatus according to the present invention, as irradiation conditions, it is required to cause a desired thermal denaturation in the focal tissue and not to damage the attention area. According to the present invention, the optimum ultrasonic wave considering the irradiation time is required. Since irradiation with high intensity can be realized, safe and efficient irradiation treatment can be realized without any side effects or the like due to excessive focus intensity and the maximum effect can be achieved within the treatment time.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an embodiment of the ultrasonic therapy apparatus according to the present invention. FIG.
As shown in FIG. 1, the applicator 1 includes a piezo element 2 for generating high-intensity ultrasonic waves, a coupling liquid 4 for guiding high-intensity ultrasonic waves to a patient 3, a coupling film 5, and an ultrasonic probe 16 for acquiring a tomographic image of a body. Be composed. Piezo element 2
Consists of one or more elements that emit intense therapeutic ultrasound.

At the time of treatment, the patient 3 is first placed on a bed (not shown) that does not starve and fixed at a predetermined position. Then, the applicator 1 is placed on the body surface of the three patients, and the coupling film 5 is brought into contact with the body surface 6 using an ultrasonic jelly (not shown) or the like.

At the time of positioning, a tomographic image including an affected part (tumor) 7 is obtained by an ultrasonic diagnostic apparatus 16 based on a reflected wave signal from the patient 3 acquired by an ultrasonic probe 15 inserted into the center of the applicator 1. And the position of the ultrasonic focus 8 of the piezo element 2 is displayed on the CRT 18 via the DSC 17 on the reconstructed image.

An instruction is issued to the stage controller 19 by a signal from the system controller 9 so that the focal position on the image and the affected part (tumor) 7 in the patient 3 are matched, and the applicator 1 is moved in accordance with the instruction. The stage 20 and the arm 21 are controlled to perform positioning.

In the present embodiment, as shown in FIG. 2, after the positioning is completed, the position of the attention area other than the surface of the patient on the console panel 10 (the position of the danger area where heat is likely to be generated upon irradiation). (Step S
1) From the relative positional relationship between the designated position and the focal point 8 position,
The optimum irradiation condition setting is read from the memory 11 (step S2), and the movement and irradiation control of the applicator 1 are performed under the instruction of the system controller 9 (step S2).
3).

Here, in the irradiation control, the waveform generating circuit 12 is driven in accordance with the input power, irradiation time and interval setting stored in the memory 11, the signal is amplified by the RF amplifier 13, and the matching circuit 14 is controlled. This is performed by exciting the piezo element 2 via the piezoelectric element.

In the above-described embodiment, the attention area of the ultrasonic wave passage is specified in accordance with the input information from the console panel 10 by the operator. The attention area may be designated by image processing and automatic extraction of the area.

The body surface position may be obtained and calculated from protrusion amount information when a probe body contact is made from a probe protrusion amount encoder (not shown). Furthermore, the irradiation condition may be set as a default value only by specifying the treatment depth or by automatic detection only from the general anatomical positional relationship of the contact position of the applicator 1.

Next, FIG. 3 shows a characteristic diagram serving as a basis for setting optimum irradiation conditions. FIG. 3A is a characteristic diagram showing a threshold value of thermal denaturation and cell destruction in a focal region, and FIG. 3B is a characteristic diagram showing a damage threshold value of an attention region tissue in an ultrasonic passage region. .

In the present embodiment, in order to cause a desired heat denaturation in the attention area and not to damage the passage area tissue,
It is necessary that the focus intensity considering the attenuation in the passing path is within the optimum denaturing condition range, and that the ultrasonic wave transmitting region is within the non-denaturing condition. By replacing the vertical axis of each characteristic diagram with the input power in consideration of the attenuation, the upper limit value and the lower limit value are obtained as a setting range of “power input in one irradiation × irradiation time”.

Hereinafter, the setting of the irradiation conditions will be specifically described with reference to FIGS. First, the absolute / relative positional relationship between the position of the attention area in the position and power ultrasound passage area of the diseased part 7, the ultrasonic wave intensity I _S1 of the focus intensity I _F1 and attention region when setting the certain input power value Calculate (Step T
1). When extending the value of the focal intensity I _F1, and ultrasonic intensity I _S1 laterally on the diagram the characteristics, irradiation available time at the focus and attention area (range) is determined (step T2).

Here, if the AND conditions of the values of I _F1 and I _S1 are taken, the irradiation time condition which causes the desired thermal denaturation in the focal tissue and does not damage the attention area is obtained (step T).
3). In this case, if the applied power is increased, both I _F1 and I _S1 increase in proportion to the applied power, and there is no solution for the irradiation time condition.

Conversely, when the applied power is reduced, the AND region is widened, but the irradiation time is lengthened, which is not practical when considering actual treatment. Therefore, considering the practical irradiation time limit in actual treatment, the set input power ×
It is found that the irradiation time condition has an upper limit and a lower limit, and the upper limit and the lower limit are obtained (step T4).

The irradiation setting may be any value, but, for example, an upper limit value is used in order to secure as much denaturation amount at one point as possible. If this setting policy is determined in advance, the applied power and the irradiation time can be automatically determined. Under the determination, the waveform generating circuit 12 is driven to generate strong ultrasonic waves from the applicator 1.

Here, the denaturation-non-denaturation threshold in the attention area varies depending on the irradiation interval (time). If the input power and the irradiation time are determined, the interval time is determined. Mutual relationship of I _F1 and I _S1 is focused degree and frequency of the sound source is determined by the relationship between the relative position and the attenuation between the focus and attention region, represented by a function. The function is stored in the memory 11 in advance, and the irradiation condition can be determined according to the above procedure by performing calculation by the system controller 9 based on the value.

The present invention is not limited to the above embodiment.
That is, the above-described embodiment is an example in which the irradiation condition is stored in the memory 11 in advance, but in the present embodiment, the irradiation condition to be stored in the memory 11 is determined in step U1 by executing the treatment ( This is to be determined prior to step U2). After the execution of the treatment, it ends in step U3,
Continue and reset the irradiation conditions.

In the above embodiment, one upper limit and one lower limit are used as the setting ranges. However, as shown in FIG. 6, an upper limit / lower limit selector 100 is provided in the system controller 9. Alternatively, one upper limit 101 and a plurality of lower limits 102a, 102b, 102c may be appropriately selected and used by the switch 103.

[0038]

As described above, according to the present invention, it is possible to realize irradiation with an optimum ultrasonic intensity in consideration of the irradiation time, so that there is no side effect due to unnecessary focus intensity and the maximum within the treatment time. It is an object of the present invention to provide an ultrasonic therapy apparatus capable of realizing safe and efficient radiation therapy with a limited effect.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the first embodiment of the present invention.

FIG. 3 is a diagram showing boundary conditions for determining irradiation conditions according to the first embodiment of the present invention.

FIG. 4 is a flowchart showing an operation for setting irradiation conditions according to the first embodiment of the present invention.

FIG. 5 is a flowchart showing the configuration of another embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Applicator 2 ... Piezo element 3 ... Patient 4 ... Coupling liquid 5 ... Coupling film 6 ... Body surface 7 ... Affected part (tumor) 8 ... Focus 9 ... System controller 10 ... Console panel 11 ... Memory 12 ... Waveform generation circuit Reference Signs List 13 RF amplifier 14 Impedance matching circuit 15 Ultrasonic probe 16 Ultrasonic diagnostic device 17 Digital scan converter (DSC) 18 CRT 19 Stage controller 20 Stage 21 Arm

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4C060 JJ25 JJ27 KK50 MM24 MM25 MM26 MM27 4C099 AA01 CA19 GA30 JA01 JA11 JA13 JA20 PA01 PA06

Claims (4)

[Claims] 1. An ultrasonic treatment apparatus for performing treatment by focusing an ultrasonic wave emitted from an ultrasonic wave source on an object treatment site, a means for giving a positional relationship between an ultrasonic focus position and an attention area position, An ultrasonic treatment apparatus comprising: irradiation condition determining means for determining an applied power and an irradiation time in accordance with a function of an intensity value at the ultrasonic focus position and the attention area position given based on the positional relationship. 2. The irradiation condition determining means stores the focus degeneration condition and the attention area non-denaturation condition in a memory in advance, and calculates and determines the irradiation condition by calling data from the memory. The ultrasonic therapy apparatus according to claim 1, wherein 3. A means for calculating and storing a focus degenerative condition and an attention area non-denaturing condition prior to treatment, wherein the irradiation condition at the time of treatment is based on the stored focus degenerate condition and attention area non-denaturation condition. The ultrasonic therapy apparatus according to claim 1, wherein the ultrasonic therapy apparatus calculates and determines the following. 4. The ultrasonic treatment apparatus according to claim 1, further comprising a unit for calculating a required interval time for the set input power and irradiation time.