JPH0241973B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a heating device for hyperthermia, and in particular, uses electromagnetic waves to locally heat cancer tissue in a living body, thereby heating the cancer tissue. This invention relates to a heating device for hyperthermia that stops the regeneration function of the body and causes death.

[Conventional technology]

In recent years, treatment methods using heating therapy (also known as "hyperthermia") have been in the spotlight, in particular in which malignant tumors are continuously heated to around 43°C for 1 to 2 hours, and this is repeated at regular intervals. A number of research reports have been published showing that this can inhibit the regenerative function of cancer cells and at the same time kill many of them (Measurement and Control).
Vol. 22, No. 10). This type of heating therapy is
There are general heating methods and local heating methods. Among these, methods using electromagnetic waves, methods using electromagnetic induction, methods using ultrasound, and the like have been proposed as local heating methods for selectively warming only the cancerous tissue and its surroundings.

On the other hand, as is already known among researchers in the art, the heating effect on cancer tissue is said to be around 43°C, and if it is lower than this, the effect will be diminished; If the concentration is too high, it may cause harm to normal tissue and is undesirable. That is, in hyperthermia, the temperature of the body must be maintained within a narrow temperature range that causes lethal damage to cancerous tissues and does not harm normal tissues.

[Problem that the invention seeks to solve]

However, regarding deep heating within the body,
Due to the specificity of biological functions, such as the cooling effect of blood flow, the target area is kept at a constant temperature of around 43℃.
It is not easy to hold for hours to two hours. In particular, heating therapy using electromagnetic waves has been abandoned for a long time because the electromagnetic wave absorption rate of the surface of the living body is extremely high, making it easy to cause burns on the surface of the living body.

[Purpose of the invention]

The present invention takes the above-mentioned prior art into account, and in particular, when the temperature rises above a set value, the present invention immediately responds to the rise and maintains a predetermined temperature at a predetermined location within the living body without causing burns on the surface of the living body. The purpose of the present invention is to provide a heating device for hyperthermia that can heat for a certain period of time.

[Means for solving problems]

Therefore, in the present invention, the temperature of the applicator that directs the electromagnetic waves output from the electromagnetic wave generating means from the living body surface side to the inside of the living body via the cooling means and propagates, and the temperature of the cooling liquid used by the cooling means are adjusted. It is equipped with a liquid temperature adjusting means and a temperature measuring means for measuring the temperature of the heated location. Further, when the temperature detected by the temperature measuring means is higher than a predetermined set value, a main control section is provided that controls the electromagnetic wave generating means to stop until the temperature drops to the set value. This main control unit further outputs a signal to start the heating treatment time immediately when the temperature of the heating area first becomes higher than the measured value, and also outputs a signal to start the heating treatment time in stages at regular intervals. a first function that controls an increase in the cooling capacity; a second function that controls a stepwise decrease in the cooling capacity of the cooling means at fixed time intervals when the temperature of the heating point becomes lower than a set value; The third function is to control the increase/decrease of the output level of the electromagnetic wave generating means with priority over the control of increase/decrease of the cooling capacity for the electromagnetic wave generating means. This aims to achieve the above-mentioned purpose.

[Effect]

After the applicator is brought into contact with the surface of the heating section, the cooling device is activated, and then the output of the electromagnetic wave generating means is gradually increased. As a result, first, the temperature of the living body surface and the electromagnetic wave irradiated portion inside the living body on the contact surface rises. In this case, the temperature inside the living body is measured by the temperature measuring means at regular intervals. In particular, when the temperature of the heating treatment part in the living body is heated above a set value, the main control part immediately acts to drive and control the liquid temperature adjustment means to control the cooling of the cooling liquid for the cooling means. .

Further, when the temperature of the heating treatment section in the living body becomes lower than the set value, the liquid temperature adjusting means is similarly operated under the control of the main control section, and the cooling liquid is controlled to rise.

In addition, the electromagnetic wave generating means increases or decreases the output level, giving priority to the temperature control using the coolant. This allows temperature control of the heating treatment section to be performed more quickly.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

The embodiment shown in FIGS. 1 to 4 is an application in which electromagnetic waves output from a magnetron 8 as an electromagnetic wave generating means are irradiated and propagated from the surface of the living body to the inside of the living body via a cooling mechanism 34 as a cooling means. a cooling device 21 as a liquid temperature adjustment means for adjusting the temperature of the cooling liquid used in the cooling mechanism 34, and a temperature sensor 30 as a temperature measurement means for measuring the temperature of a heated location. There is.

Furthermore, when the temperature detected by the temperature sensor 30 is higher than a predetermined set value, a main control unit 18 is provided that controls the magnetron 8 to stop until the temperature drops to the set value.

The main control unit 18 further outputs a heating treatment time progression start signal immediately when the temperature of the heating area first becomes higher than the measured value, and also outputs a cooling treatment time stepwise signal at regular intervals. The first function increases the cooling capacity of the cooling mechanism 34, and the second function controls the cooling capacity of the cooling mechanism 34 to decrease in stages at fixed time intervals when the temperature of the heating point becomes lower than the set value.
The third function is to control the increase/decrease of the output level of the magnetron 8 with priority over the increase/decrease control of the cooling capacity of the cooling mechanism 34.

To explain this in more detail, in FIG. 1, the hyperthermia heating device is comprised of a microwave generation section 2, a control section 4, and a microwave irradiation section 6 as its main parts.

The microwave generator 2 includes a magnetron 8 as an electromagnetic wave generator and a power source 9 for driving the magnetron 8. This microwave generating section 2 is energized by a switch 46 that is controlled based on a command from the main control section 18 in the control section 4, so that its output is repeatedly turned on and off (ON and OFF). .

On the other hand, in this embodiment, the microwave irradiation unit 6
Applicator 2 that irradiates microwave to living body 32
0 and a cooling mechanism 34 as a cooling means for cooling the opening side of the applicator 20, that is, the surface of the living body 32, and a first temperature measuring means for detecting the temperature of the cancer tissue. The configuration is equipped with a temperature sensor 30. The cooling mechanism 34 includes a cooling device 21 as a liquid temperature adjusting means for cooling the cooling liquid;
A cooling control circuit 24 as a liquid temperature control circuit for controlling the cooling of a cooling liquid such as water, and a pump 22 for circulating water cooled by the cooling device 21 are connected and equipped.

As shown in FIG. 2, the applicator 20 is in close contact with a living body 32 and irradiates the living body 32 with electromagnetic waves,
This antenna is used to heat the target cancer tissue.
As described above, this applicator 20 is equipped with a cooling mechanism 34, which cools the surface of the living body 32 to prevent significant overheating due to dielectric loss caused by electromagnetic wave irradiation on the skin of the living body 32. It is configured to effectively utilize heat conduction to cancer tissue and prevent skin burns.

The cooling mechanism 34 is provided with a pipe 36 for passing the water used as a cooling liquid in this embodiment, and the water cooled by the cooling device 21 is passed through the pump 2.
2 forcibly circulates and passes through the cooling mechanism 34 to cool the opening surface of the applicator 20, that is, the surface of the living body 32. On the other hand, the temperature of the cooling water is controlled by the cooling control circuit 24, and the surface of the living body 32 is cooled by changing the water temperature, thereby increasing the temperature of the cancerous tissue heated by the microwave. is adjusted from the surface side of the living body 32.

Further, the temperature sensor 30 inside the living body 32 is a sensor for detecting the temperature of cancer tissue, and the output of the cooling device 21 is adjusted based on the information obtained here.

On the other hand, the main control unit 18 controls the temperature sensor 30
The temperature of the cancerous tissue is maintained at a desired value based on this information and information from the input/output unit 44 that receives instructions from the operator. The output of the cooling device 21 (cooling effect) is controlled via the D/A conversion circuit 48 and the output of the magnetron 8 is controlled via the switch 46 so that the heating state is controlled to the operator. Information is sent to an output section 44.

In this case, a first function within the main control section 18 operates a pump controller unit (not shown) to increase or decrease the rotational speed of the pump 22. Further, a second function within the main control section 18 controls the output of the magnetron 8 to be increased or decreased as necessary via a switch 46.

Next, the overall operation of the above device will be explained based on FIG. Note that here, the heating setting temperature for the cancer tissue is set to 43°C.

First, the cooling device 21 is operated (step 50 in FIG. 3), and after the water has been sufficiently cooled, the pump 22 is started (step 52 in the same figure). After irradiating the microwave for a certain period of time (56 in the same figure), the output of the magnetron 8 is then turned off (58 in the same figure).
The temperature inside the living body 32 is measured by the temperature sensor 30 (60 in the same figure). The reason why microwave irradiation is not performed during temperature measurement is because the temperature sensor 30 inserted into the living body 32 is affected by microwaves.
This is to eliminate slight errors that may occur. After the temperature is measured, it is determined whether the internal temperature of the living body 32 is higher than a set value (43° C. in this example) inputted in advance by the operator (see Figure 6).
2). If the internal temperature is lower than the set value, the output (cooling effect) of the cooling device 21 is lowered by one step (in this case, since water is being circulated by the pump 22, the output of the cooling device 21 is turned off). ), thereby raising the surface temperature of the living body 32 (64 in the same figure), and increasing the temperature from the surface of the living body 32 so that the cancer tissue heated by the microwave irradiation quickly reaches the set temperature. It is designed to adjust the heating. As a result, if the temperature of the cancerous region becomes higher than the set value, the temperature measurement loop is repeated without microwave irradiation until the temperature of the cancerous tissue falls below the set value. Then, by utilizing this period, the output (cooling effect) of the cooling device 21 is increased step by step (68 in the same figure), thereby cooling the water and cooling the living body 3.
The temperature is adjusted from the surface side of the living body 32 so that the temperature of the cancerous tissue quickly reaches the set value.

By the way, the correlation between the heating time and the lethality of cancer tissue depends on the time it takes for the cancer tissue to reach a temperature around 43°C. Therefore, in this embodiment, the time is measured from the time when the temperature of the cancer tissue, which is the heating part, exceeds the set value (66 in the same figure), and when the heating time inputted by the operator in advance has arrived. The heating is completed at 72 in the same figure.

FIG. 4 shows the temperature distribution state of cancer tissue (A in the figure) when heating is performed using this embodiment, and the temperature distribution state of cancer tissue when heating is performed using control in the conventional technology (A in the figure). B) in the figure is shown. In this figure, the interval during which the temperature increases is during microwave irradiation, and the interval during which the temperature decreases is during temperature measurement, and the output of the magnetron 8 is turned off during temperature measurement.

In this case, in the conventional technology, the flow rate of water for cooling the surface of the living body 32 is not varied with respect to the temperature of the cancerous part, and the on/off control of the microwave oscillator is controlled even if the target temperature (43°C) is exceeded. (Heating for a certain period of time and pausing for a certain period of time) is repeated repeatedly, which makes the internal heating extremely inaccurate. On the other hand, in this example, since the above-mentioned control method is adopted, it is possible to quickly reach the target temperature and quickly cool down even if the target temperature is exceeded, so it is almost constant at 43℃. It maintains the temperature.

In the above embodiment, if it is desired to control the surface temperature of the living body 32 more accurately, as shown in FIG. A sensor 28 is provided to measure the surface temperature of the living body 32, and the information therefrom is input to the main control unit 18 via the A/D converter 40, as shown in the flow chart shown in FIG. The control may be performed based on the flowchart shown in FIG. 3 (the dotted line portion of the flowchart shown in FIG. 3 has been changed, and the rest is the same as that shown in FIG. 3). That is, if the internal temperature is lower than the set value, the surface temperature measured by the temperature sensor 28 (see Figure 6)
0') is lower than the surface temperature set by the operator (63 in the same figure), and if the surface temperature is lower than the set value, the cooling device 2
Lower the output (cooling effect) of 1 by 1 step (see figure 6).
4) Conversely, if the surface temperature is high, the output (cooling effect) of the cooling device may be increased by one step (63' in the same figure).

Furthermore, if the cancerous part 100 is present on or near the surface of the living body 32, it is non-invasive (there is no need to insert the temperature sensor 30 inside the living body 32).
(See Figure 7). That is, when the cancerous part 100 exists near the surface of the living body 32,
Since the temperature of the cancerous part 100 and the surface temperature of the living body 32 can be considered to be approximately equal, the cooling device 2 is operated based on the information from one temperature sensor 28 instead of the other temperature sensor 30 inserted into the living body 32.
It is sufficient to control the output (cooling effect) of No. 1 (8th
(see figure).

Furthermore, in this case, since one temperature sensor 28 is not affected by microwaves, there is no need to turn off the output of the magnetron 8 when measuring temperature. Therefore, as shown in FIG. 9, after turning on the output of the magnetron 8 (102 in the same figure), the temperature of the surface of the living body 32 is measured (104 in the same figure), and if the surface temperature is lower than the set value, The output (cooling effect) of the cooling device 21 is lowered (106 in the figure) and microwave irradiation is continued. If the surface temperature becomes higher than the set value, the output of the magnetron 8 is cut off (108 in the same figure), the output (cooling effect) of the cooling device 21 is increased by one step (110 in the same figure), and the surface temperature is raised to the set value. A control method may be adopted in which this loop is repeated without irradiating microwaves until the temperature drops further. This method allows for more accurate heating of the target area compared to the method shown in FIG.
Furthermore, regarding temperature measurement of the heating section inside the living body 32,
When using a thermometer that is less affected by electromagnetic waves, it is of course possible to configure the thermometer to measure the temperature while irradiating the microwave.

〔Effect of the invention〕

Since the present invention is configured and functions as described above,
According to this, by prioritizing the control of the output of the electromagnetic wave generating means, it is possible to quickly increase or decrease the temperature of the heated area, and it is possible to actively cool the area with the cooling liquid. As a result, it is possible to extremely easily heat a heating point within a living body to a predetermined temperature continuously for a certain period of time without having to complicatedly control the electromagnetic wave generation means. Since the temperature is controlled, a large amount of cooling liquid is not required, and the entire device can be downsized, making it possible to provide an unprecedented and excellent hyperthermia heating device.

[Brief explanation of the drawing]

FIG. 1 is an overall system diagram showing an embodiment of the present invention, FIG. 2 is a perspective view showing an example of an applicator,
Fig. 3 is a flowchart showing the operation of Fig. 1, Fig. 4 is a diagram showing the heating state according to the embodiment of Fig. 1 in comparison with the conventional example, and Fig. 5 shows another embodiment. 6 is a flowchart showing the operation of FIG. 5, FIG. 7 is a system diagram showing other embodiments, and FIGS. 8 to 9 are flowcharts showing the operation of FIG. 7. . 8...Magnetron as a means of generating electromagnetic waves,
20... applicator, 21... cooling device as liquid temperature adjustment means, 24... liquid temperature control circuit, 28,
30...Temperature sensor as temperature measurement means, 3
4... Cooling mechanism as cooling means.

Claims (1)

[Claims] 1. An applicator that directs and propagates electromagnetic waves output from an electromagnetic wave generating means from the biological surface side into the living body via a cooling means, and a temperature of a cooling liquid used in the cooling means. In a hyperthermia heating device equipped with a liquid temperature adjusting means and a temperature measuring means for measuring the temperature of a heating point, when the temperature detected by the temperature measuring means is higher than a predetermined set value. is equipped with a main control section that stops and controls the electromagnetic wave generating means until the temperature decreases to the set value, and this main control section further controls the operation of controlling the electromagnetic wave generating means immediately when the temperature of the heating point first becomes higher than the measured value. A first function that outputs a signal to start the progression of the heating treatment time and controls the cooling capacity of the cooling means to be increased in stages at regular intervals, and when the temperature of the heating point becomes lower than a set value. a second function that controls the cooling capacity of the cooling means to be lowered stepwise at regular intervals; and a third function that controls the output level of the electromagnetic wave generating means to increase or decrease in priority to controlling the increase or decrease of the cooling capacity of the cooling means. A hyperthermia heating device characterized by having the following functions and the following.