JP4091179B2 - Ultrasonic therapy device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ultrasonic treatment apparatus for treating a tumor in a living body using ultrasonic waves.
[0002]
[Prior art]
In recent years, the flow of minimally invasive treatment called MIT (Minimally Inverse Treatment) has attracted attention in various medical fields.
One example is the practical application of a stone crushing device that irradiates high-power ultrasonic waves from outside the body and treats stones in a non-invasive manner for the treatment of lithiasis, which greatly changed the treatment of urinary stones.
[0003]
Examples of the powerful ultrasonic wave generation source used in this calculus breaking device include an underwater discharge method, an electromagnetic induction method, a micro explosion method , and a piezo method. Especially in the apparatus using a piezo-type powerful ultrasonic wave generation source, although there is a disadvantage that the pressure of the strong ultrasonic wave is small, there is a small focal point and there is no consumable, and the high-power ultrasonic pressure can be arbitrarily controlled, and a plurality of There is an excellent advantage that the focal position can be arbitrarily controlled by controlling the phase of the driving voltage applied to the piezoelectric element (Japanese Patent Laid-Open No. 60-145131, US Pat. No. 4,526,168).
[0004]
In particular, in the case of malignant neoplasms, so-called cancers, the function and appearance of the organs are often greatly impaired due to the fact that many of the treatments depend on surgical techniques. For this reason, even if the life is prolonged, a heavy burden remains on the patient. Therefore, development of a less invasive treatment method (apparatus) considering QOL (Quality Of Life) is strongly desired.
[0005]
Conventionally, surgery, radiation therapy, and chemotherapy (anticancer drugs) are the three major therapies for cancer, but in the flow of minimally invasive treatment as described above, there is a treatment method using heat as one of the new cancer treatment techniques. It's getting attention. A prominent example is hyperthermia treatment.
[0006]
Hyperthermia treatment is a treatment method that selectively kills only cancer cells by heating and maintaining the affected area at 42.5 to 43 ° C. or higher by utilizing the difference in heat sensitivity between tumor tissue and normal tissue. .
[0007]
As a heating method, a method using an electromagnetic wave such as a microwave precedes, but in this method, it is difficult to selectively warm a deep tumor due to the electrical characteristics of a living body, and the depth is 5 cm. Good results cannot be expected for these tumors.
[0008]
In recent years, in order to improve the poor penetration of electromagnetic wave energy, a microwave / RF wave antenna is inserted into the affected area intraoperatively, laparoscopically or percutaneously, and the temperature around the antenna is heated to 60 ° C. or higher. As a result, new therapies that have improved the local therapeutic effect are in the spotlight (Iwata et al .: J. Microwave Surgical).
[0009]
However, since this treatment method also requires puncture of the organ, it is less invasive than conventional surgical treatment, but there is a problem that there are side effects such as bleeding and seeding (metastasis) associated with puncture.
[0010]
In order to solve the problems of these conventional methods, a method for heat-treating a deep tumor from outside the body by using ultrasonic energy with good energy convergence and high depth of penetration has been proposed (Japanese Patent Laid-Open No. Sho). 61-13955).
[0011]
In addition, the above-mentioned warming treatment method is further advanced so that the ultrasonic wave generated from the piezo element is sharply focused on the affected part, the tumor part is heated to 80 ° C. or more, and the tumor tissue is instantly heat-denatured and dead. A method is also considered (G. Vallancien et. Al: Progress in Urol. 1991, 1, 84-88, US Pat. No. 5,150,711).
[0012]
In this treatment method, unlike conventional hyperthermia, ultrasound with very strong intensity (several hundred to several thousand W / cm ² ) is applied to a limited area near the focal point, so only a narrow area near the focal point is applied. Instantaneous heat denaturation is made.
[0013]
However, since it is necessary to cauterize the entire affected area while scanning a small focal point, accurate positioning of the focal point is considered to be very important. As a solution to this problem, Japanese Patent Application Laid-Open No. 5-253192 has already known a technique for measuring an intraoperative fever point by imaging a non-invasive sensitivity distribution in the body using a chemical shift of MRI.
[0014]
Further, even in a system using only ultrasound, the ones of Patent Nos. 1851304, 1821772, and 1765452 detect reflected waves from the focal region of therapeutic ultrasound and display them on the ultrasound image. The method is disclosed.
[0015]
[Problems to be solved by the invention]
As described above, the conventional ultrasonic therapy apparatus has a problem in that since the focal point is very sharply focused and the ultrasonic energy is strongly concentrated, an ultrasonic intensity more than necessary, that is, heat generation occurs in the focal region. It was.
[0016]
In addition, if the ultrasonic intensity in the focal region is reduced without considering the irradiation time, there is a problem that the entire treatment time increases, and the treatment becomes unrealistic.
An object of the present invention is to provide a highly safe ultrasonic therapy apparatus capable of realizing optimal irradiation that causes desired heat denaturation in a focal tissue and does not damage an attention area.
[0017]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides an ultrasonic treatment apparatus that performs treatment by focusing an ultrasonic wave irradiated from an ultrasonic wave generation source on a subject treatment site.
Means for providing a positional relationship between the ultrasonic focal position and the attention area position;
From the optimal denaturation condition value of the ultrasonic intensity consisting of the upper and lower limits for degeneration but not destroying the cells at the focal position, and the upper limit value of the ultrasonic intensity at which the cells do not denature at the position of the attention area, the input power and irradiation time a irradiation condition determining means for determining a,
In determining the input power by the irradiation condition determining means, the upper limit value is used .
[0018]
Further, the irradiation condition determining means stores in advance a modification condition at the focal position and a non-denaturation condition at the attention area position in a memory, and calculates and determines the irradiation condition by calling up data from the memory. It is characterized by.
[0019]
Furthermore, the present invention is non-denaturing conditions calculated by the comprising means for storage, denaturing conditions and the attention region located in the focal position said storage in denaturing conditions and the attention region located in the focal position prior to treatment The irradiation condition at the time of treatment is calculated and determined on the basis of the non-denaturing condition.
[0020]
The apparatus further comprises means for calculating a necessary interval time for the determined input power and irradiation time.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an embodiment of an ultrasonic therapy apparatus according to the present invention. As shown in FIG. 1, an applicator 1 includes a piezoelectric element 2 that generates high-power ultrasonic waves, a coupling liquid 4 that guides high-power ultrasonic waves to a patient 3, a coupling film 5, and an ultrasonic probe that acquires tomographic images inside the body. 15 is comprised. The piezo element 2 is composed of one or a plurality of elements that irradiate high-power therapeutic ultrasonic waves.
[0022]
At the time of treatment, the patient 3 is first placed on a bed (not shown) and fixed at a predetermined position. Then, the applicator 1 is placed on the surface of the patient 3 and the coupling film 5 is brought into contact with the body surface 6 using an ultrasonic jelly (not shown).
[0023]
At the time of positioning, a tomographic image including the affected part (tumor) 7 is reconstructed by the ultrasonic diagnostic device 16 based on the reflected wave signal from the patient 3 acquired by the ultrasonic probe 15 inserted in the center of the applicator 1. Then, the position of the ultrasonic focal point 8 of the piezo element 2 is superimposed on the CRT 18 via the DSC 17 and displayed on the reconstructed image.
[0024]
A command is sent 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 coincide with each other, and the applicator 1 is moved in accordance with the instruction. The arm 21 is controlled to perform positioning.
[0025]
In the present embodiment, as shown in FIG. 2, after the positioning is completed, the position of the patient's body surface and other caution areas (the position of the danger area that is likely to generate heat during irradiation) is designated on the console panel 10. (Step S1) Based on the relative positional relationship between the designated position and the focal point 8 position, the optimum irradiation condition setting is read out from the memory 11 (Step S2). Irradiation control is performed (step S3).
[0026]
Here, in the irradiation control, the waveform generation 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 piezoelectric circuit is passed through the matching circuit 14. This is done by exciting the element 2.
[0027]
In the above-described embodiment, the attention area of the ultrasonic passage route is specified according to the input information from the console panel 10 by the operator. The attention area may be designated by processing and automatic extraction.
[0028]
The body surface position may be obtained and calculated from protrusion amount information at the time of probe body surface contact 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 automatically detecting the contact position of the applicator 1 based on the general anatomical positional relationship.
[0029]
Next, FIG. 3 shows a characteristic diagram that is the basis for setting the optimum irradiation conditions. FIG. 3 (a) is a characteristic diagram showing threshold values for heat denaturation and cell destruction in the focal region, and FIG. .
[0030]
In the present embodiment, in order to cause desired thermal denaturation in the focal region and not cause damage to the passage region tissue, the focal strength considering attenuation in the passage path is within the optimum denaturing condition range, and The ultrasonic wave passage area must be within the non-denaturing condition. By replacing the vertical axis of each characteristic diagram with input power in consideration of attenuation, an upper limit value and a lower limit value can be obtained as a setting range of power that can be input by one irradiation × irradiation time.
[0031]
Hereinafter, the irradiation condition setting 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 Ru is calculated (step T1). When the values of the focal intensity I _F1 and the ultrasonic intensity I _S1 are extended laterally on each characteristic diagram, the irradiation possible time (range) in the focal point and the attention area is obtained (step T2).
[0032]
Here, when the AND condition of the values of I _F1 and I _S1 is taken, an irradiation time condition that induces desired thermal denaturation in the focal tissue and does not damage the attention area is obtained (step T3). In this case, if the input power is increased, both I _F1 and I _S1 increase in proportion to the input power, and there is no solution for the irradiation time condition.
[0033]
On the other hand, when the input power is lowered, the AND area is expanded, but the irradiation time becomes longer, which is not realistic when actual treatment is considered.
Therefore, in consideration of a practical irradiation time limit in actual treatment, it is found that there are an upper limit value and a lower limit value in the set input power × irradiation time condition, and the upper limit value and the lower limit value are obtained (step T4).
[0034]
The irradiation setting may be any value. For example, an upper limit value is used in order to secure as much modification amount at one point as possible. If this setting policy is determined in advance, the input power and irradiation time can be determined automatically. Under this determination, the waveform generation circuit 12 is driven to generate a powerful ultrasonic wave from the applicator 1.
[0035]
Here, the denaturation-non-denaturation threshold in the attention area varies depending on the irradiation interval (time), and if the input power and the irradiation time are determined, the interval time is determined. The mutual relationship between I _F1 and I _S1 is determined by the relationship between the focusing degree and frequency of the sound source, the relative position between the focal point and the attention area, and the attenuation, and is expressed by a certain function. The function is previously stored in the memory 11, and the irradiation condition can be determined according to the above procedure by performing the calculation by the system controller 9 based on the value.
[0036]
The present invention is not limited to the embodiment described above. That is, the embodiment described above is an example in which the irradiation condition is stored in the memory 11 in advance, but in this embodiment, the irradiation condition to be stored in the memory 11 is set as the execution of treatment (step U1). in step U2) are those that seek me Sakiritsu. After the execution of the treatment, in step U3, the process is ended, continued, and irradiation conditions are reset.
[0037]
In the previous embodiment, one upper limit value and one lower limit value were used as the setting range. However, as shown in FIG. 6, an upper limit / lower limit selector 100 is provided in the system controller 9 to The upper limit value 101 and the plurality of lower limit values 102a, 102b, and 102c may be appropriately selected and used by the switch 103.
[0038]
【The invention's effect】
As described above, according to the present invention, irradiation with the optimum ultrasonic intensity considering the irradiation time can be realized, so that there is no side effect due to excessive focal intensity and the maximum effect is achieved within the treatment time. It is possible to provide an ultrasonic therapy apparatus that can realize safe and efficient irradiation therapy.
[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 exemplary embodiment of the present invention.
FIG. 3 is a diagram showing boundary conditions for determining irradiation conditions in the first embodiment of the present invention.
FIG. 4 is a flowchart showing an operation for setting an irradiation condition in 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 fluid 5 ... Coupling membrane 6 ... Body surface 7 ... Affected part (tumor)
DESCRIPTION OF SYMBOLS 8 ... Focus 9 ... System controller 10 ... Console panel 11 ... Memory 12 ... Waveform generation circuit 13 ... RF amplifier 14 ... Impedance matching circuit 15 ... Ultrasonic probe 16 ... Ultrasonic diagnostic apparatus 17 ... Digital scan converter (DSC)
18… CRT
19 ... Stage controller 20 ... Stage 21 ... Arm

Claims (4)

In an ultrasonic treatment apparatus for performing treatment by focusing ultrasonic waves emitted from an ultrasonic wave generation source on a subject treatment site,
Means for providing a positional relationship between the ultrasonic focal position and the attention area position;
From the optimum denaturation condition value of the ultrasonic intensity consisting of the upper and lower limits at which the cells are not destroyed but denatured at the focal position, and the upper limit value of the ultrasonic intensity at which the cells are not denatured at the attention area position, the input power and the irradiation time a irradiation condition determining means for determining a,
An ultrasonic therapy apparatus characterized in that the upper limit value is used when the input power is determined by the irradiation condition determining means . The irradiation condition determining means stores in advance a modification condition at the focal position and a non-denaturation condition at the attention area position in a memory, and calculates and determines the irradiation condition by calling up data from the memory. The ultrasonic therapy apparatus according to claim 1. Means for calculating and storing a degeneration condition at the focal position and a non-denaturation condition at the attention area prior to treatment, and based on the stored degeneration conditions at the focal position and the non-denaturation condition at the attention area The ultrasonic treatment apparatus according to claim 1, wherein the irradiation condition at the time of treatment is calculated and determined. The ultrasonic therapy apparatus according to any one of claims 1 to 3, further comprising means for calculating a necessary interval time for the determined input power and irradiation time.

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