JP3556964B2 - Ultra-high frequency heating treatment equipment - Google Patents

Description

[0001]
[Industrial applications]
TECHNICAL FIELD The present invention relates to an ultra-high-frequency heating device that irradiates a living body with high-frequency waves and necrotices and destroys cancer cells in the living body by dielectric heating.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there has been known an ultrashort-wave heating treatment apparatus for radiating and supplying high-frequency energy from a pair of electrodes sandwiching a living body to heat and treat a diseased part of the living body (Japanese Patent Laid-Open No. 55-130675, for example). JP-A-56-80265). This ultra-high frequency heating treatment apparatus, for example, when both abnormal cell tissue constituting cancer and other tumors and surrounding normal cell tissue are heated in a temperature range of 40 ° C. or more, the former abnormal cell tissue becomes normal. Paying attention to the fact that the temperature becomes higher by 2 to 2.5 ° C. than that of the cell tissue, the temperature is kept at 43 ° C. or less which does not necrotize the normal cell tissue, and the abnormal cell tissue is raised to around 45 ° C. Necrosis and collapse.
[0003]
In such a device, since the condition of the heating temperature of the affected part is severe as described above, monitoring of the internal temperature is extremely important.In the case of heating treatment, high-frequency energy is emitted to monitor the temperature in the living body. A required number of needle-shaped thermometers are inserted into the body to measure the temperature. The heating temperature is controlled by adjusting the output of high-frequency energy while monitoring the temperature measurement result.
[0004]
[Problems to be solved by the invention]
Conventional ultra-short-wave heating treatment devices adjust the output of high-frequency energy based on the temperature in the living body, but in reality, the correlation of the heating temperature with the output of high-frequency energy is low, and the temperature measurement in the living body is difficult. Even though the results are used as a guide, it is very difficult to control a suitable heating temperature. That is, in the ultra-high frequency heating treatment apparatus, impedance mismatch between the apparatus and the living body is apt to occur due to movement of the patient during treatment, or a change in the condition of the living body due to an increase in temperature, and transmission loss occurs at the electrode position. For this reason, for example, when there is a relatively large transmission loss, of the high-frequency energy output from the apparatus main body, the amount of energy effectively used for the high-frequency electric field applied to the living body is unstable. It becomes difficult to predict the warming temperature of the living body from the output.
[0005]
In addition, since a required number of needle thermometers are inserted into the living body and the temperature of the affected part is directly measured, the patient is in pain during the treatment.
[0006]
The present invention has been made in view of the above, and it is an object of the present invention to provide an ultra-high frequency heating treatment apparatus capable of easily controlling output by monitoring high-frequency energy actually supplied into a living body.
[0007]
[Means for Solving the Problems]
The present invention provides an ultrashort-wave heating device that places a diseased part inside a living body between a pair of electrodes and generates a high-frequency electric field between the electrodes to dielectrically heat the diseased part. a high frequency generation means capable, in which a detection means for detecting in order to monitor the magnetic field strength in the raw material near neighbor position during dielectric heating (claim 1).
[0008]
Further, the present invention comprises a display means for displaying the electromagnetic field strength detected by the detection means (claim 2).
[0009]
Further, the present invention includes power detection means for detecting high-frequency power supplied to the electrode, and power display means for displaying high-frequency power detected by the power detection means (claim 3). .
[0010]
Further, the present invention comprises a temperature calculating means for calculating the temperature of the body from the electromagnetic field intensity detected by the detection means, the display means is for displaying the calculated temperature (claim 4) .
[0011]
[Action]
According to the present invention, the high-frequency power supplied from the high-frequency generation means to the electrode is displayed, the strength of the electromagnetic field at a position near the living body is detected, and the detection result is displayed. Since the electromagnetic field is generated in a living body and is caused by a high-frequency electric field, the intensity thereof has a correlation with the energy amount of the high-frequency electric field. On the other hand, the energy amount of the high-frequency electric field is directly related to the heating temperature of the living body due to the dielectric heating. Therefore, the electromagnetic field intensity has a correlation with the heating temperature of the living body due to the dielectric heating.
[0012]
Therefore, by monitoring the intensity of the electromagnetic field, it is possible to know whether or not the high-frequency power generated by the high-frequency generation means is effectively used for dielectric heating. Based on this information and the supplied high-frequency power, the high-frequency power can be determined. Power output adjustment can be performed efficiently.
[0013]
Further, according to the present invention, the electromagnetic field strength is converted into the temperature of the living body and displayed, and the temperature of the living body can be predicted based on the temperature information.
[0014]
【Example】
FIG. 2 is an external view of the ultra-high-frequency heating treatment apparatus according to the present invention. The ultrahigh-frequency heating treatment apparatus includes a control unit 100, a treatment table 200, a gantry 300, and a high-frequency generation unit 400.
[0015]
The control unit 100 includes an operation unit 101 for controlling heating, cooling, matching, and the like, a high-frequency output from the high-frequency generation unit 400, a display unit 102 for monitoring a heating state, a treatment state of a patient, and the like, and a treatment. An output unit 103 such as a printer for outputting various data and an input unit 104 for inputting various information related to treatment are provided.
[0016]
The gantry 300 irradiates a patient with high-frequency waves, and has a through hole 301 in the center of the gantry body. A support portion 302 is provided on the inner surface of the through hole 301 so as to be rotatable with respect to the gantry body, and the rotation angle thereof can be adjusted by an operation portion 303. A pair of electrode portions 304 and 305 project from the support portion 302 so as to face each other. The electrode portions 304 and 305 are provided with the same or similar disk-shaped electrode plates 306 and 307 covered with cooling pads 308 and 309 at the tips. The electrode portions 304 and 305 are movable in the radial direction, and press the electrode plates 306 and 307 against a patient during treatment. The electrode units 304 and 305 can also be operated by the operation unit 303. The treatment table 200 has a paired structure sandwiching the gantry 300.
[0017]
Further, an electromagnetic field strength meter 310 is protrudingly provided on an axis of the support section 302 which is orthogonal to the axis of the electrode sections 304 and 305. The electromagnetic field strength meter 310 detects the amount of high-frequency energy actually supplied into the living body by detecting the magnetic field of the electromagnetic field generated around the patient during treatment, and a sensor that picks up the magnetic field at the distal end. A part 311 is provided. The electromagnetic field strength meter 310 is movable in a radial direction and a circumferential direction, and the sensor unit 311 can be arbitrarily set at a desired position near a living body. Usually, at the time of heating treatment, the sensor unit 311 is, for example, at an intermediate position between the electrode plates 306 and 307 and 15 cm or less from the living body so as to detect the strength of the electromagnetic field at a position as close to the living body as possible. Is located in the vicinity of When the electrode plates 306 and 307 are not the same and one of them is small, the sensor unit 311 may be arranged to be biased toward the smaller electrode plate.
[0018]
The electromagnetic field strength meter 310 is also operable by the operation unit 303, but the electromagnetic field strength meter 310 is automatically set to a predetermined position according to the size and the set position of the electrode plates of the electrode units 304 and 305. You can also do so. Further, the detection data of the electromagnetic field strength meter 310 is input to the control unit 100.
[0019]
The high-frequency generator 400 generates, for example, a high frequency of several MHz applied to the electrode plates 306 and 307, and includes a power supply circuit, a high-frequency generation circuit, a matching circuit, and a high-frequency power meter. The driving of each unit of the high frequency generation unit 400 is controlled by the control unit 100.
[0020]
FIG. 1 is a block diagram showing the configuration of an ultrahigh-frequency heating treatment apparatus according to the present invention. In the figure, a power supply circuit 401, a high-frequency generation circuit 402, a matching circuit 403, and a high-frequency power meter 404 are provided in the high-frequency generation section 400. The power supply circuit 401 supplies a predetermined power to the high frequency generation circuit 402. The high-frequency generation circuit 402 generates a high frequency of, for example, 8 MHz by a self-excited oscillation method, and its output can be changed within a range of several tens of watts to several hundreds of watts to 1,000 watts. Note that the output of the high-frequency generation circuit 402 is controlled via the control circuit 105 in the control unit 100. That is, when an output set value is input from the input unit 104 of the control unit 100, the control circuit 105 generates an output control signal based on the output set value, and inputs the output control signal to the high frequency generation circuit 402 to output the output control signal. Control the output.
[0021]
The matching circuit 403 performs impedance matching between the high-frequency generation circuit 402 and the living body (load) 500 placed between the electrode plates 306 and 307, and is adjustable via the control circuit 105.
[0022]
The high-frequency power meter 404 measures the high-frequency power P supplied to the living body 500 between the electrode plates 306 and 307. The high-frequency wattmeter 404 detects the incident power Pi to the electrode plates 306 and 307 and the reflected power Pr from the electrode plates 306 and 307, and the supply power P (= Pi-Pr) supplied from both powers to the load side. Is calculated. The measurement value of the high-frequency power meter 404 is input to the control circuit 105 and displayed on the display unit 102.
[0023]
The electromagnetic field strength meter 310 includes the sensor unit 311 and the receiver unit 312. The sensor section 311 is composed of a minute coil that picks up the magnetic field H, and is arranged at a position near the living body 500 so that the magnetic field H vertically intersects the coil surface. The receiver 312 detects the intensity Pw of the electromagnetic field picked up by the sensor 311 and inputs the detection data to the control circuit 105. The control circuit 105 displays the result of the detection data directly or in a required unit on the display unit 104. For example, the magnetic field strength H (A / m) is converted into a unit such as electric field strength (V / m) or electric power (W / m ² ) and displayed on the display unit 102 .
[0024]
The strength Pw of the electromagnetic field at a position near the living body 500 is displayed separately from the supply power P because a part of the supply power P supplied to the load side is directly transmitted from the electrode plates 306 and 307 to the space. The radiation is emitted as an electromagnetic wave (hereinafter referred to as radiation loss), and it is taken into consideration that all of the radiation is not used for the energy of the electromagnetic field between the electrode plates 306 and 307.
[0025]
FIG. 3 is a diagram showing the relationship between the supply power P (W) and the temperature increase ΔT (= T−T0 (initial temperature)) (° C.) of the object to be heated, and FIG. (A / m) and the temperature rise ΔT (° C.) of the body to be heated.
[0026]
In both figures, as shown in FIG. 3, a cubic agar K having a side of 20 cm is placed as a dummy of the living body 500 between the electrodes 306 and 307, and at a position between the electrode plates 306 and 307, 15 cm from the agar K. The relationship between the strength Pw of the electromagnetic field in the vicinity of the agar K and the temperature increase ΔT of the agar K was examined by disposing the sensor unit 311 of the electromagnetic field strength meter 310 at a distance of.
[0027]
In both figures, experiments were performed on three types of disc-shaped electrode plates having a diameter of 25 cm for the electrode plate 307 and diameters of 10 cm, 14 cm, and 25 cm for the electrode plate 306 . “2” and “3” indicate that the diameter of the electrode plate 306 is 10 cm, 14 cm, and 25 cm. On the other hand, the thermometer is on the axis of the opposing electrode plate. It is inserted at a position 3 to 4 cm below the plate 306, in the case of “2” , 4 to 5 cm below the electrode plate 306, and in the case of “3” , it is inserted at an intermediate position between the electrode plates 306 and 307. This is in consideration of the actual situation at the medical site where a small-sized electrode plate on the lesion side is used in order to concentrate the electromagnetic field at that portion when the lesion is located in a biased position in the living body. is there.
[0028]
As shown in FIG. 3, the power supply P and the temperature increase ΔT of the body to be heated have a weak correlation, and it is difficult to predict the temperature of the body to be heated from the integrated value of the power supply P. Therefore, it can be seen that it is difficult to suitably control the heating temperature of the living body 500 even if the output of the high-frequency generation circuit 402 is adjusted by monitoring only the supplied power P. This is considered to be due to a large influence of a loss that is not used as electromagnetic field energy in a living body such as radiation loss in the electrode plates 306 and 307. Considering that in actual medical practice, the characteristics of the living body 500 as a load are not uniform and the contact conditions between the electrode plates 306 and 307 and the living body 500 easily change due to movement of the patient during treatment. It is estimated that the correlation between the supplied power P and the temperature increase ΔT of the heated object is further weakened.
[0029]
On the other hand, as shown in FIG. 4, the relationship between the magnetic field strength H and the temperature rise ΔT of the body to be heated has a good correlation, and the strength Pw of the electromagnetic field at a position near the living body 500 is monitored. It is understood that if the output of the high-frequency generation circuit 402 is adjusted, the heating temperature T of the living body 500 can be controlled relatively favorably. Since the electromagnetic field near the living body 500 is a part of the electromagnetic field actually formed between the electrode plates 306 and 307, the strength Pw of the electromagnetic field is the strength of the electromagnetic field in the living body 500, that is, It is considered to have a strong correlation with the amount of electromagnetic field energy. On the other hand, in the dielectric heating phenomenon, the electromagnetic field energy irradiated into the living body 500 is consumed by heat due to dielectric loss. Therefore, the intensity Pw of the electromagnetic field is strongly correlated with the temperature characteristic due to the dielectric heating. Conceivable.
[0030]
Therefore, if the supplied power P and the intensity Pw of the electromagnetic field at a position near the living body 500 are monitored, the actual heating state of the living body 500 can be predicted from the intensity Pw of the electromagnetic field. By adjusting the output (supply power P), the heating treatment can be effectively and efficiently controlled.
[0031]
In the above-described embodiment, the strength Pw of the electromagnetic field is directly displayed as the magnetic field strength, the electric field strength, the power, and the like, but the correlation between the strength Pw of the electromagnetic field and the temperature increase ΔT of the living body 500 is used. Alternatively, the electromagnetic field strength Pw may be converted into the heating temperature T of the living body 500, and the heating temperature T may be displayed.
[0032]
For example, assuming that the integrated value of the electromagnetic field strength Pw is PW (= Pw · t (time)) and the temperature rise ΔT of the living body 500 is represented by K · PW, the heating temperature T of the living body 500 is T = Since it is represented by K · PW + T0 (initial temperature), the warming temperature T of the living body 500 can be predicted from the strength Pw of the electromagnetic field using this equation.
[0033]
Since the proportional coefficient K generally changes depending on the initial temperature T0, if a plurality of arithmetic expressions are prepared in accordance with the initial temperature T0 and the corresponding arithmetic expressions are used in accordance with the initial temperature T0, the heating may be performed. The accuracy of the calculated value of the temperature T is improved. Further, since the proportional coefficient K changes depending on the heating temperature T, if it is set as a function K (T) for the heating temperature T, the accuracy of the calculated value of the heating temperature T is further improved. When the high frequency is intermittently supplied from the high frequency generation circuit 402, the heating temperature T of the living body 500 decreases during the output suspension period. Therefore, a correction term for correcting the decrease is added to the above-described arithmetic expression. It is good to do.
[0034]
It should be noted that a conversion table may be prepared in advance in place of the above arithmetic expression, and the heating temperature T may be directly calculated from the initial temperature T0 and the integrated value PW of the electromagnetic field strength Pw using the conversion table. Good.
[0035]
Further, the output control value of the high-frequency generation circuit 402 may be estimated from the detected data to the intensity Pw of the electromagnetic field, and the estimated value may be displayed. By doing so, the operator can know the approximate output control value of the high-frequency generation circuit 402, and the operability of the output control can be improved.
[0036]
It is preferable to display the supply power P and the intensity Pw of the electromagnetic field, but it is also possible to display only the intensity Pw of the electromagnetic field as a guide for checking the heated state of the living body 500. .
[0037]
【The invention's effect】
As described above, according to the present invention, an ultrashort-wave heating device that places an affected part inside a living body between a pair of electrodes and dielectrically heats the affected part by a high-frequency electric field generated between the electrodes, Since the strength of the electromagnetic field at the time is detected and the detection result is monitored, it is easy to predict the amount of high-frequency energy actually supplied into the living body and the heating temperature of the living body. Efficient output control becomes possible.
[0038]
In addition, since the electromagnetic field intensity is converted into the warming temperature of the living body and displayed, the warming temperature of the living body can be predicted more reliably, and the output control of the high frequency generator can be more effectively performed. it can.
[Brief description of the drawings]
FIG. 1 is a block diagram showing the configuration of an ultra-high frequency heating treatment apparatus according to the present invention.
FIG. 2 is an external view of an ultrahigh-frequency heating treatment apparatus according to the present invention.
FIG. 3 is a diagram showing a relationship between supply power P and a temperature increase ΔT (° C.) of a heated body.
FIG. 4 is a diagram showing a relationship between the strength of an electromagnetic field at a position near a heated body and a temperature increase ΔT (° C.) of the heated body.
[Explanation of symbols]
REFERENCE SIGNS LIST 100 control unit 101 operation unit 102 display unit 103 output unit 104 input unit 105 control circuit 200 treatment table 300 gantry 304, 305 electrode unit 306, 307 electrode plate 310 electromagnetic field intensity meter 311 sensor unit 312 receiver unit 400 high frequency generation unit 401 power supply Circuit 402 High frequency generation circuit 403 Matching circuit 404 High frequency power meter 500 Living body

Claims (4)

In an ultrashort-wave heating device that places a diseased part inside a living body between a pair of electrodes and generates a high-frequency electric field between the electrodes to dielectrically heat the diseased part, an output-changeable high-frequency generation that generates a high-frequency wave supplied to the electrodes means and, VHF warming therapy apparatus characterized by comprising a detecting means for detecting in order to monitor the magnetic field strength in the raw material near neighbor position during dielectric heating. 2. The apparatus according to claim 1 , further comprising display means for displaying the intensity of the electromagnetic field detected by said detection means . 3. The ultrashort wave processing device according to claim 1, further comprising: power detection means for detecting high-frequency power supplied to the electrode; and power display means for displaying high-frequency power detected by the power detection means. Heat treatment device. 4. The ultra-short-wave heating treatment apparatus according to claim 1, further comprising a temperature calculating unit for calculating a temperature in a living body from an electromagnetic field intensity detected by the detecting unit, and wherein the display unit displays the calculated temperature. An ultra-high frequency heating treatment device for displaying a temperature.

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