JPH08117263A - Thermotherapy device - Google Patents

Abstract

PURPOSE: To control the heated temperature of the affected part at constant temperature in a free standing way by using a ceramic thermister having a PTC characteristic and a step function between temperature and resistance values, for the heater of a warming treatment device for warming the affected part. CONSTITUTION: The probe body 2 of a heating probe 1 is a flexible tube capable of being inserted in a bio-tube cavity, and has an internal and external double tube structure. Also, internal and external tubes 5 and 6 are separated from each other, and a fluid forced flow passage is formed within the external tube 6. On the other hand, heater wiring insertion space is formed within the internal tube 5. Also, the forward end of the tube 6 forms an inflatable balloon over the prescribed range as a radiator, and a fluid introduction port 8 is formed at the base end of the tube 6. A heater 3 is mounted on the forward end of the tube 5. Also, heater wiring 9 is led inside the tube 5 within the range of the balloon 7 and connected to a connector 10 at the base end of the tube 5. In this case, the heater 3 is a thermister having a PTC characteristic as well as a step furaction between temperature and resistance values.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermotherapy device for locally heating an affected part of a human body.

[0002]

2. Description of the Related Art Hyperthermia has been known as one of the physical therapies for diseases whose main symptoms are "numbness", "paralysis" and "pain". Examples of the thermotherapy include a hot air bath, a steam bath, a warm bath, a whole-body bath or a partial bath, and a local treatment using infrared irradiation, a partial lightning bath, or a hot compress.

[0003] On the other hand, a treatment method for heating the local area of the body is expected as one of the physical treatment methods for "cancer" as hyperthermia. In Hyperthermia, it is said that it is basically important to reliably heat the target area in the body and to measure the temperature accurately.

There are non-invasive methods and invasive methods for heating the local parts of the body, and generally, the non-invasive methods are believed to be superior to the invasive methods. As a typical non-invasive method, there is a method using a high frequency dielectric heating method. In this method, for example, a high frequency of 8 MHz is used to heat the affected area of the cancer to 43 to 45 ° C. by a dielectric heating method to treat the cancer. It was expected that the therapeutic effect would be improved in combination with chemotherapy and chemotherapy. In this method, in short, the body is sandwiched between a pair of electrode plates and a high frequency is applied to cause vibrational friction in the cell molecules at the electromagnetic wave irradiation portion to increase the local temperature.

Regarding the clinical experiment cases in which the radiation heating method was used in combination with the radiation therapy, out of the 63 cases for which data collection was completed, 33 cases (52.4 cases) in which the tumor disappeared due to the treatment.
%), Tumor reduction rate of 80% or more 12 cases (19.0
%), 13 cases (20.6%) with a tumor shrinkage rate of 50% or more and less than 80%, only 5 cases (8.0%) with a tumor shrinkage rate of less than 50%, and excellent treatment results were obtained. There is a report that it was done (Hyperthermia fighting against cancer, 2nd edition, Tsutomu Sugawara, p8 Kinyoshido, 1992).

[0006]

However, recently, even in the case of an actual clinical case, a deep cancer cannot be uniformly heated even with an electromagnetic wave (RF wave) of 100 MHz or less capable of heating a deep part. In addition, it was pointed out that RF waves could not be focused on the tumor part, and clinical trials suggested the effectiveness of combined hyperthermia,
It is reported that the tumors are superficial or intraluminal superficial, and that these are the applicable diseases of cancer hyperthermia.
August 10, 1994, p98-99).

The fundamental problems of the high-frequency dielectric heating method are low-temperature burns and the problem of measuring the heating temperature at different affected sites, and there is a limit to non-invasive local heating. Low-temperature burns occur on the skin surface in contact with the electrodes when a low temperature of 43 to 45 ° C. is repeatedly applied to the human body, and the burden on the patient is large. Furthermore, the affected area is 43 to 45 ° C.
In order to heat the skin, the temperature of the affected area must be accurately measured, but at the present time, a method for non-invasively measuring the temperature of the affected area has not been established. As a method of non-invasively measuring the temperature of the affected area, CT, MRI, ultrasound,
Although a temperature measurement method using electromagnetic waves has been considered, it is not at the stage of practical use (Ayumi of Medicine Vol. 168 N
o. 1 1994, 1.1 p19).

As an example of a method for invasively heating a local area, there is a method of directly heating a tumor by inserting a heating tool into a body cavity. Even if the above non-invasive method is used, if the applicable disease is currently limited to superficial or intraluminal surface tumors, the method of invasively inserting a warming tool to heat the affected area is the first method. It may be said that it is inferior to the non-invasive method. An example of this is, for example, JP-A-5-22.
No. 0116 introduces a thermotherapy applicator. This applicator is provided with a coil-shaped heating electrode as a heating tool on the peripheral surface of the distal end of a flexible tube, and a high frequency is applied between this heating electrode and an extracorporeal electrode installed on the surface of the patient's body. This is one of the attempts to heat the affected area to a predetermined temperature and is an application example of the dielectric heating method. However, when using the dielectric heating method, even if a constant voltage power supply is used to generate heat between the electrodes at a constant temperature, it is difficult to maintain a constant temperature because the heat radiation and heat storage conditions of the affected area are not always constant. Must be incorporated together to control exothermic temperature under the direction of the temperature sensor.

In order to keep the heating temperature of the affected area constant, it is necessary to accurately detect the heating temperature of the affected area and strictly control the heat generation temperature of the warming tool by the detection signal, but it is necessary to keep the heating temperature within a certain range. Accurately detecting the heating temperature of the affected area is a difficult technique.

An object of the present invention is to obtain a step function (IEC Pub.738-1 Direc) between temperature and resistance value.
try Hate Positive Positive Step-
function Temperature Coef
PT that has "ficient Thermistors"
C (Positive Temperature Co
An object of the present invention is to provide a device for hyperthermia treatment that utilizes an effective characteristic.

[0011]

In order to achieve the above object, a thermotherapy device according to the present invention is a thermotherapy device including a heater for heating an affected part, wherein the heater is
It is a ceramic thermistor having PTC characteristics and having a step function between temperature and resistance value.

Further, in the thermotherapy device having a radiator, the heater is built in the radiator, and the radiator dissipates the heat generated by the heater to heat the affected area.

Further, the thermotherapy device has a heater at the tip of the probe main body and a power supply wiring for the heater drawn out through the inside of the probe main body, wherein the probe main body is a flexible tube.

The ceramic thermistor having PTC characteristics is a barium titanate-based semiconductor ceramic.

Further, the heat radiator is a balloon, the balloon is attached to the tip of the probe main body, and can be expanded and contracted by press-fitting or discharging of fluid, and the heater is installed within the range of the balloon, It heats the fluid.

Further, in the thermotherapy device having a temperature sensor, the temperature sensor detects the temperature of the heated surface of the affected part due to the heat generation of the heater, and outputs the temperature detection information to the outside through the signal wiring in the tube of the probe body. It is what is output.

[0017]

In the present invention, a ceramic thermistor having PTC characteristics is used as the heater for heating the tumor in the affected area. Specifically, at present, barium titanate (Ba
A semiconductor ceramic thermistor mainly composed of TiO ₃ ).

1A and 1B show the resistance temperature characteristic and the current-voltage characteristic of the PTC thermistor. As we all know,
The PTC thermistor has a low resistance on the low temperature side, a resistance that increases rapidly near the Curie temperature, and a high resistance on the high temperature side. When a barium titanate-based semiconductor ceramic thermistor having a Curie temperature of about 43 to 45 ° C. is used as a heater for heating the affected portion at 43 to 45 ° C., the affected portion is heated at the Curie temperature. However, when heat is actively released from the affected area and falls below the Curie temperature, the heater generates heat, and when the heat temperature rises to the Curie temperature, resistance increases and the heat generation stops, and the heat generation temperature of the PTC thermistor is autonomous. Controlled to a constant temperature. The heater does not generate heat as long as the temperature of the affected area is maintained at the Curie temperature.

Therefore, as long as the PTC characteristics of the PTC thermistor can be relied upon for local heating of the tumor, it can be said that the temperature measurement of the affected area for controlling the heating temperature of the affected area is theoretically unnecessary. However, it is important to monitor the temperature of the affected area because there is a problem with the accuracy of the thermistor characteristics.

When the heater is brought into direct contact with the affected area,
The surface of the heater that contacts the affected area is the heated surface of the affected area. When a radiator is used and the radiator is heated by a heater to dissipate the heat to the radiator, the surface of the radiator becomes the heated surface of the affected area.

A normal blood vessel expands when heated and blood increases. If the heat is about 43 to 45 ° C., the heat is diffused by the blood flow, so that normal cells do not receive much heat.

On the other hand, the blood vessels in the tumor cannot diffuse even if it receives heat because the vascular endothelial cells are sparsely present. As a result, heat is accumulated. This is called the heat storage effect of cancer (see NIKKEI MEDICAL August 10, 1994 p98). If that is the case, if normal cells were heated by the heater, heat dissipation would proceed and the heater would continue to generate heat continuously. The heating of the tumor part, which has a large heat storage effect due to the effect, requires less current flowing to the heater and shorter fever duration than heating the normal cell part.

Therefore, by measuring the heat generation state of the heater or the energization time to the heater, it is possible to determine whether or not the heating location is appropriate. This is a characteristic peculiar to PTC having autonomous temperature controllability.

[0024]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 2, the example is an example applied to a heating probe for performing thermal treatment of an affected part in a body cavity. The heating probe is a combination of a probe body 2, a heater 3 and a temperature sensor 4.

The probe main body 2 is a flexible tube which can be inserted into the lumen of a living body. The flexible tube is made of a resin that is compatible with living organisms, such as silicone resin, and has an inner-outer double tube structure. The inner and outer tubes 5 and 6 are isolated from each other, and a fluid is press-fitted into the outer tube 6. A heater wiring insertion space is formed in the passage and the inner pipe 5. The distal end portion of the outer tube 6 constitutes a balloon 7 that can be expanded and contracted over a certain range as a heat radiator, and has a fluid introduction port 8 on the base side of the outer tube 6. The heater 3 is attached to the tip of the inner tube 5, and the balloon 7
Within this range, the heater wire 9 is passed through the inner pipe 5 and is connected to the connector 10 at the base.

The balloon 7 receives the pressure of the fluid press-fitted from the inlet 8 and inflates it in a fixed shape. The inflation shape of the balloon 7 can be set freely. FIG. 2 shows a form in which the end surface of the balloon 7 is inflated into a conical shape having a flat surface.

When making contact with the inner peripheral surface of the inner cavity, FIG.
As described above, a balloon 7 that expands into a disc shape or a column shape is used. As a fluid to be pressed into the balloon 7, a fluid substance having excellent thermal conductivity, such as barium gel, is used. It is convenient to preliminarily heat the fluid substance to an appropriate temperature in order to shorten the heating time.

The heater 3 is provided within the expansion range of the balloon. The heater 3 is a thermistor having a PTC characteristic and a step function between temperature and resistance value, and a semiconductor ceramic thermistor containing barium titanate as a main component is suitable. The Curie temperature can be set by changing the composition of the barium titanate-based semiconductor ceramics.

In hyperthermia of cancer, the heating temperature of the affected area is 4
Since the temperature is 3 ° C. to 45 ° C., the fluid in the balloon 7 is heated at a temperature of at least 43 ° C. or higher, and the Curie temperature is determined so that the surface temperature of the balloon 7 is set to 43 ° C. to 45 ° C.

The temperature sensor 4 practically measures the surface temperature of the balloon 7. However, even if the heating temperature of the heater 3 is measured by mounting it on the surface of the heater 3 as in 4 ', the heating temperature can be predicted. Temperature sensor 4
An NTC ceramic thermistor is used for the wiring, and its wiring 11 is connected to the connector 10 through the inner tube 5 together with the heater wiring 9.

In the exemplary embodiment, the connector 10 is connected to an external control power supply 12 and a temperature measuring instrument 13 including an ammeter.
When treating a diseased part connected to the living body opening, the thermotherapy device of the present invention is inserted into the cavity through the anus, oral cavity or incision, and the fluid is press-fitted through the introduction port 8 to expand the balloon 7 in a fixed shape to make its surface Contact the affected area in the body cavity. Confirmation of the heating position by the heater 3 is performed with an endoscope, X-ray,
This is done using ultrasonic waves.

On the other hand, power is supplied to the heater 3 from the external control power supply 12 through the connector 10 to generate heat. The heat of the heater 3 also heats the fluid in the balloon 7, and the surface thereof maintains a constant temperature corresponding to the Curie temperature of the heater 3. However, when heat is actively radiated to the affected area and the heat generation temperature drops below the Curie temperature, the heater 3 continues to generate heat until the Curie temperature is reached, and when the Curie temperature is reached, the current is It drops to the value required for heat retention,
Stop fever and maintain constant temperature.

The surface temperature of the balloon 7 or the heat generation temperature of the heater 3 is detected by the temperature sensor 4, and the temperature detection information is transmitted to the temperature measuring device 13 through the connector 10. The surface temperature of the balloon 7 is a treatment temperature at which the affected area is brought into contact with and heated, and in the case of cancer treatment, 43 ° C. to 4 ° C.
Keep at 5 ° C. The heat generation temperature of the heater 3 in use is
Indicates the Curie temperature.

As long as heat is radiated to the affected area,
The heater continues to generate heat and the heating range increases. However, when the heat dissipation to the affected area is poor, the heat is accumulated and the heat generation of the heater 3 stops, so it can theoretically be judged that the heating location is the correct tumor location. The heat generation state of the heater 3 can be known by an ammeter connected to the heater wiring.

In the above embodiments, the example in which the balloon is used as the heat radiator to heat the inside of a certain range of the lumen has been shown. However, the radiator is not necessarily limited to the balloon, and the heater 3
The surface may be simply coated. FIG.
This is an example in which the glass coat 14 used in a normal ceramics thermistor is used as a radiator. The glass coat 14 is
Inside the heating probe 1, the heater 3 and the temperature sensor 4 are built in the glass coat 14 which can be molded into a free shape and which is shaped to have a surface shape suitable for heating the affected area, and the heating probe 1 is attached. The wires 9 and 11 of the heater 3 and the temperature sensor 4 are connected to the connector 10 through the. According to this embodiment, in use, the heat of the heater 3 is dispersed in the glass coat, and the affected area is heated through the surface of the glass coat 14. With a glass coat or a radiator with the same effect as a glass coat, the heat radiation surface can be formed into a free shape, and a ceramic thermistor with a diameter of 0.5 mmφ can be used for a probe with a diameter of 10 mm or less that is normally used Can be incorporated. Alternatively, the tip portion may be formed into a needle shape, and the tip may be pierced into the body for invasive use.

Furthermore, the present invention can be applied not only to the treatment of the affected part of the inner cavity but also to the local hyperthermia treatment of the skin by using a heater processed into a flat plate shape.

[0037]

As described above, according to the present invention, the thermistor having the PTC characteristic and the step function between the temperature and the resistance value is used as the heater for heating the affected area.
The heating temperature of the affected part can be autonomously controlled to a constant temperature.

However, it is possible to ensure the safety of the treatment by performing the treatment while monitoring the actual heating temperature of the affected area by using the temperature sensor. Whether or not there is a tumor at the heated location can be determined by judging the degree. INDUSTRIAL APPLICABILITY The present invention is not limited to the treatment of the affected part of the internal cavity, and has the effects of being easy to handle as a thermotherapy device inside and outside the body and being widely available at a low price.

[Brief description of drawings]

1A is a resistance temperature characteristic of a PTC thermistor, FIG.
(B) is a figure which shows a current-voltage characteristic.

FIG. 2 shows an embodiment of the present invention, (a) is a side view,
(B) is a front view.

FIG. 3 is a diagram showing a main part of another embodiment of the present invention.

FIG. 4 is a diagram showing still another embodiment of the present invention.

[Explanation of symbols]

 1 Heating Probe 2 Probe Body 3 Heater 4 Temperature Sensor 5 Inner Tube 6 Outer Tube 7 Balloon 8 Inlet 9 Heater Wiring 10 Connector 11 Temperature Sensor Wiring 12 External Control Power Supply 13 Measuring Instrument 14 Glass Coat

Claims (6)

[Claims] 1. A thermotherapy device comprising a heater for heating an affected area, wherein the heater is a ceramic thermistor having a PTC characteristic and having a step function between temperature and resistance value. Heat treatment equipment to do. 2. A thermotherapy device having a radiator, wherein the heater is built in the radiator, and the radiator dissipates heat generated by the heater to heat the affected area. Item 2. The thermotherapy device according to Item 1. 3. A thermotherapy device having a heater at the tip of a probe main body, and a heater power supply wire drawn out to the outside through the probe main body, wherein the probe main body is a flexible tube. The thermotherapy device according to claim 1 or 2, which is characterized. 4. The thermotherapy device according to claim 1, wherein the ceramic thermistor having PTC characteristics is a barium titanate-based semiconductor ceramic. 5. The heat radiator is a balloon, the balloon is attached to the tip of the probe body, and can be expanded and contracted by pressurizing or discharging a fluid, and the heater is provided within the range of the balloon, The thermotherapy device according to claim 2, wherein the fluid is heated. 6. A thermotherapy device having a temperature sensor, wherein the temperature sensor detects a temperature of a heated surface of an affected area due to heat generation of a heater, and transmits the temperature detection information to the outside through a signal wire in a tube of a probe main body. The thermotherapy device according to claim 3, wherein the thermotherapy device is output.