JP3084124B2 - Non-invasive temperature measurement device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-invasive temperature measuring apparatus used for measuring the temperature of a living body, for example, for diagnosis of a hyperthermia or a lesion.

[0002]

2. Description of the Related Art As a technique for non-invasively measuring the temperature of an object to be measured, there is known a method called "radiometry" for receiving a microwave emitted from the object to be measured and measuring the temperature of the object. Japanese Patent Publication No. 63-1064 discloses an example of using this method for a living body. Further, a balance method geometry as a measurement method corresponding to a change in the reflection coefficient of an antenna, which is a problem in the case of a living body or the like, is described in Elect.Leters, 14, 194 to 196.

A technique using this geometry as a temperature measurement technique in warming treatment is disclosed in Japanese Patent Publication No. 63-1064. Japanese Patent Publication No. 62-7331 discloses automatic heating control by non-invasive temperature measurement. At the time of temperature measurement, the weak microwave radiated from the object cannot be measured unless the electromagnetic wave for the heating treatment is turned off.Therefore, a technique for turning off the heating output at the time of measurement is disclosed in Japanese Patent Publication No. 57-53110. It is shown.

[0004]

By the way, this type of radiometer receives a microwave with a fixed reference noise source, and outputs a microwave power radiated from an object to be measured from an output of the microwave receiver. That is, there are a method of measuring the brightness temperature and a method of a balance method in which the output of the microwave receiver is made zero by changing the amount of radiation from the reference noise source and the noise temperature.

[0005] This balance method radiometer generally comprises:
A microwave is generated from the reference noise source, radiated from the antenna to the object to be measured, and microwaves emitted and reflected from the object to be measured are received by the antenna. The noise temperature of the reference noise source is adjusted so as to become zero, and the temperature of the reference noise source when the difference becomes zero is directly captured as the temperature of the object to be measured. That is, highly accurate measurement is possible without being affected by the power reflection coefficient of the interface between the antenna and the living body.

As described above, the balance method has an advantage that the influence of the reflection coefficient of the antenna is removed and the measurement accuracy is improved. However, since the noise temperature of the reference noise source must be changed until the output of the microwave receiver becomes zero, there is an operational disadvantage that the measurement time required for the temperature becomes considerably long.

Furthermore, when the balance method radiometer is used as a temperature measuring device in a heating treatment such as hyperthermia, the heating operation is interrupted during the measuring time. And it falls. Further, the temperature of the heating target after the heating output is turned off is not usually stable. Therefore, if the measurement time is long, it may be rather impossible to measure the temperature accurately.

On the other hand, in actual clinical practice using hyperthermia, even if there is no detailed information of what the temperature is, a temperature value which is higher or lower than a target temperature for heating, or which is not desired to be raised any more. If it is determined whether the above condition is satisfied or not, the warming treatment apparatus can be sufficiently controlled.

In view of this, the present invention focuses on this and measures the luminance temperature of an object in a short measurement time while suppressing the decrease in the merit of the balance method of improving the measurement accuracy by removing the influence of the reflection coefficient, and measuring the luminance temperature of the object. It is an object of the present invention to provide a non-invasive temperature measurement device that measures whether a temperature is equal to or higher than a reference temperature value.

[0010]

SUMMARY OF THE INVENTION According to the present invention, there is provided a method for receiving a thermal noise radio wave radiated from an object to be measured and adjusting a reference noise temperature of a reference noise source in accordance with the thermal noise radio wave. In a non-invasive temperature measurement device that measures the temperature of a measurement target, a reference noise temperature that can be balanced with a reference luminance temperature corresponding to a target temperature of the measurement target is determined, and a reference noise source is generated so as to emit the reference noise temperature. Means for adjusting, and means for comparing the value of the measured luminance temperature with the value of the reference luminance temperature and outputting the comparison result.

[0011] This eliminates the need for an operation for balancing at the time of measurement, thereby greatly reducing the measurement time. In addition, since the noise temperature of the reference noise source is set to a value that should balance with the reference luminance temperature, the reference luminance temperature is the same as that measured by the balance method, and as a result, The temperature of the measurement object can be measured without being affected by the reflection coefficient of the interface between the antenna and the measurement object. Thus, the comparison result of whether the measured value is above or below the reference temperature can be captured without being affected by the reflection coefficient.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. First, a system of the entire apparatus will be described with reference to FIG.

In FIG. 1, reference numeral 1 denotes a living body (body cavity) to be measured, into which a probe 2 is inserted. The probe 2 has a transmitting / receiving antenna 3 at its tip. Further, the probe 2 has an antenna 3
The balloon 4 is provided so as to surround. The antenna 3 irradiates the living body 1 with microwaves or receives thermal noise radio waves (microwaves) radiated from the living body 1.

The balloon 4 surrounding the antenna 3 is supplied with an expansion liquid such as water from a supply / discharge device (not shown) through a conduit (not shown) formed inside the probe 2. And the balloon 4 in the probe 2
Swells by the injection of the liquid and functions to hold the antenna 3 at an arbitrary position in close contact with the inner surface of the cavity of the living body 1.
A temperature sensor 5 is provided in the balloon 4 so as to measure the temperature of the liquid in the balloon 4.

The antenna 3 is connected to a coaxial switch 7 through a coaxial cable 6. By switching the coaxial switch 7, a heating oscillator 8 or a microwave receiver 9 is selectively connected to the antenna 3. ing. The coaxial switch 7 and the microwave receiver 9 are connected through a coaxial cable 11. Microwave receiver 9
Is sent to the temperature measurement control unit 15. As will be described later, the reference noise source of the microwave receiver 9 is controlled by a signal from the temperature measurement control unit 15.

On the other hand, the coaxial cables 6 and 11 form a base of the probe 2 and include a plurality of temperature sensors 1.
.. 12n, 13a, 13b,... 13n are provided at a plurality of locations at predetermined intervals along the axial direction. These temperature sensors 12a, 12b,.
, 13a are the cables 6, 1
1 is for correction to eliminate measurement errors due to temperature.

The temperature sensors 12a, 12b,... 1
.. 13n detect the temperature distribution of the coaxial cables 6 and 11 in the axial direction. The detected data is sent to a temperature measurement control unit 15 to be described later via the thermometer 14, and is used by the temperature measurement control unit 15 for calculation of correction and calibration. The final measured temperature data obtained by the temperature measurement control unit 15 is sent to the heating control unit 16. The measurement result is displayed on the display unit 20 for temperature measurement.

The water in the water tank 18 used for measuring the calibration data is heated or cooled by a temperature raising / lowering means (not shown) and adjusted to a predetermined temperature. The temperature of the water is detected by the water tank temperature sensor 19 and measured by the thermometer 14. The measured temperature information is transmitted to the temperature measurement controller 1.
5 and the control unit 15 for temperature measurement controls the water tank 18 so that the water temperature becomes a predetermined temperature value. This aquarium 18
It is used at the time of calibration, and is not used for ordinary measurement.

The heating oscillator 8 is provided with the heating control unit 16.
Is controlled by The heating control unit 16 also controls the coaxial switch 7 and sends the switching information to the temperature measurement control unit 15. The heating control unit 16 obtains temperature information from the temperature measurement control unit 15 for heating control. And
This heating status is displayed on the display unit 20.

Next, the configuration of the internal circuit of the microwave receiver 9 will be described with reference to FIG. That is, the port of the circulator 22 is connected to the coaxial cable 11 via the Dickey switch 21. The Dickey switch 21 is turned on / off by a rectangular synchronization signal from the synchronization signal generator 31.
And the circulator 22.

The circulator 22 has three ports to which a Dickey switch 21, an isolator 23, and a reference noise source 24 are connected in the order of signal transmission. The thermal noise signal sent from the Dickey switch 21 is amplified by the RF amplifier 25 via the isolator 23 and input to the RF terminal of the mixer 26. The isolator 23 is an RF amplifier 25
This is for absorbing the signal reflected later. The output of the local oscillator 27 is input to the LO terminal of the mixer 26 via the attenuator 28, and the mixer 26 performs frequency conversion by multiplying the input by the output of the RF amplifier 25. This signal is sent to the amplifier 29 via the IF terminal of the mixer 26.

The attenuator 28 is adjusted so as to feed an optimum LO terminal output for adjusting the sensitivity of the mixer 26. The noise signal is amplified by the IF amplifier 29,
At 0, the noise power is detected and output as a DC component. The detected and output DC component is input to a lock-in amplifier 32 that is synchronized with a synchronization signal from the synchronization signal generator 31. As described above, the Dickey switch 21
Is also on / off controlled by the same synchronization signal.

The temperature measuring control unit 15 has an input unit 33 and is composed of a microcomputer and its peripheral circuits, which also perform control over the entire temperature measuring device. further,
The temperature measurement control unit 15 has an internal memory, in which the measured temperature is stored as a file, and the temperature detected by the thermometer 14 is sequentially stored.

Then, the temperature measurement control unit 15 obtains a reference noise temperature that can be balanced with the reference luminance temperature corresponding to the target temperature of the object to be measured, and adjusts the reference noise source so as to emit the reference noise temperature. And a function of comparing the value of the measured luminance temperature with the value of the reference luminance temperature and outputting the comparison result. Further, it has a function of setting a calibration mode and a measurement mode according to the operation of the input unit 33.

Next, the operation of the microwave receiver 9 configured as described above will be described. First, when the Dickey switch 21 is on, the voltage V _ON shown below is applied to the detector 3.
The detection output is 0. V _ON = k · G · C _d (1-R) T _obj · B + k · _GC
d · R · T _ref · B k: Boltzmann constant

G: System gain up to IF amplifier C _d : Sensitivity constant of detector R: Reflection coefficient of interface between antenna and object to be measured B: Bandwidth T _obj : Noise temperature radiated from object to be measured T _ref : noise temperature of the reference noise source

Next, consider the off state. When turned off, noise power from the reference noise source 24 is sent to the Dickey switch 21 through the circulator 22. Then, the light is totally reflected by the Dickey switch 21, passes through the circulator 22 again, and is input to the RF amplifier 25 via the isolator 23. Therefore, the voltage V shown below
_OFF is detected and output. V _OFF = k · G · C _d · T _ref · B

The lock-in amplifier 32 multiplies the input signal by the reference signal and integrates the result, that is, is a device for extracting only the same frequency component as the reference signal. Therefore, if it is simply understood, the difference between the detection signals when the Dickey switch 21 is turned on and when the Dickey switch 21 is turned off is detected. Then, lock-in amplifier 3
The output V _LOCK of 2 is as follows. V _LOCK = k · G _SYS · B (1−R) (T _obj −T _ref ) G _SYS : gain of the entire system Here, if the reference noise source 24 is adjusted so that V _LOCK becomes zero, the reflection coefficient R If is not 1, then T _obj =
It becomes T _ref , and a measurement _{independent of} the reflection coefficient R can be performed.
This is the principle of the balance method.

Next, the operation and use of this device will be described. First, a calibration mode is set by the input unit 33, and a start operation of the mode is performed. That is, the probe 2 is put in the water in the water tank 18, and the water temperature in the water tank 18 is changed according to a command from the temperature measurement control unit 15 within a range including the temperature of the object to be measured.

Here, in each case where the temperature is changed, the water temperature in the temperature water tank 18 is T _w ′, the brightness temperature measured by this device is T _ref ′, and the T _w ′ and T _ref ′ are Are measured in various ways to obtain a correlation therebetween, and the data of the correlation is stored in the internal memory of the temperature measurement control unit 15. At this time, the temperature sensors 12a,
12n, 13a, 13b,..., 13n are also stored in the internal memory of the temperature measurement control unit 15.

This series of operations is called calibration data measurement. Do this occasionally to calibrate the device. Since the brightness temperature measurement at the time of this calibration is not time-sensitive, it is better to use the balance method.

Next, actual heating and temperature measurement will be described. First, as shown in FIG. 1, a probe 2 is inserted into a living body (body cavity) 1 to be heated / measured and mounted.
At this time, the balloon 4 is inflated and fixed at a predetermined position of the living body 1. Then, the coaxial switch 7 is operated by the signal from the heating control unit 16, and the antenna 3 is connected to the heating oscillator 8. Further, the heating oscillator 8 is turned on by a signal from the heating control unit 16, and the heating oscillator 8 performs an output operation. And antenna 3
The living body 1 is heated by the microwave irradiated from the body.

The heating output at this time may be fixed, but if it is variable, the output value can also be adjusted by the heating control unit 16. Also,
Heating display unit 2 displays the heating output value and the accumulated energy amount
0 is displayed. After heating for a certain time, the heating control unit 1
First, the output of the heating oscillator 8 is turned off by the signal from 6.

Next, the coaxial switch 7 is switched,
The antenna 3 is connected to the microwave receiver 9 side. Then, first, the temperature of the liquid in the balloon 4 detected by the temperature sensor 5 is taken into the temperature measurement control unit 15 via the thermometer 14.

On the other hand, the noise temperature of the microwave radiated from the living body 1 is attenuated by the liquid in the balloon 4. Therefore, assuming that the desired brightness temperature of the living body 1 is x, the temperature of the antenna 3 at which x is obtained is the temperature of the liquid in the balloon 4 taken in and the attenuation constant of the liquid (this is the internal memory). Is stored in advance in the following.) That is, the original brightness temperature of the living body 1 is replaced with the brightness temperature of the antenna 3, and this is set as the reference antenna temperature (reference brightness temperature).

The temperature at which the antenna 3 receives the brightness temperature output from the living body 1 as a reference is determined by the balloon 4.
The calculation is performed by the arithmetic function in the temperature measurement control unit 15 using the internal temperature of the temperature measurement.

The calculation method for calculating the reference antenna temperature includes a method of approximating the radiation direction of the antenna 3 so as to be perpendicular to the axis of the antenna 3 and a method of measuring the radiation field distribution near the antenna 3 and calculating the data. There is a method of performing calculation by using as an example. In any method, the decay constant of the liquid in the balloon 4 needs to be input into the memory of the temperature measurement control unit 15 in advance. In this calculation, if the temperature can be measured by the temperature sensor 5 even during the heating, the temperature measurement control unit 15 can read this temperature and calculate in advance during the heating. .

When the reference antenna temperature is determined, the temperature measurement control unit 15 sets the reference noise source 24 in the microwave receiver 9.
Is set to a noise temperature that should be balanced with the reference antenna temperature.

As an actual calculation method, the correlation between the water temperature T _W in the calibration data and the measured value T _ref is calculated by using the temperature sensors 12a and 12a when the calibration data is measured and when the actual measurement is performed.
2b, ... 12n, 13a, 13b , ... and corrected by a temperature difference between the cable 6 and 11 measured in 13n, obtained by substituting the reference antenna temperature of the water temperature T _w of the correlation of the corrected. Then, the noise temperature _Tref of the reference noise source 24 that should be balanced with the reference antenna temperature can be calculated.

After setting the noise temperature of the reference noise source 24 to the value obtained by the above calculation, the output of the microwave receiver 9 is taken into the temperature measurement control unit 15, and the actual measured value of the microwave receiver 9 is obtained. It is determined whether the temperature is higher or lower than the reference antenna temperature. That is, it is determined whether the output of the lock-in amplifier 32 is positive, negative, or zero.

If the temperature is higher than the reference antenna temperature, the temperature of the living body 1 to be heated / measured is lowered without being heated until the temperature becomes lower. If the temperature is low, a signal to that effect is sent to the heating control unit 16. Then, the heating control unit 16 switches the coaxial switch 7 to return to the connection to the heating oscillator 8 side, and turns on the output of the heating oscillator 8 to perform heating.

If the noise temperature of the reference noise source 24 is adjusted to a value that balances with the reference antenna temperature, when the actual reception luminance temperature reaches the reference antenna temperature, regardless of the reflection coefficient R of the antenna 3 The output of the microwave receiver 9 should be zero. Therefore, when the actual measured value is higher and lower than the reference antenna temperature, it is obtained as a difference in the sign of the output of the microwave receiver 9 and can be clearly determined.

However, if the noise temperature of the reference noise source 24 is simply fixed near the temperature to be measured, there is no guarantee that the measured value when balanced is the reference antenna temperature, and the difference between the two temperatures is calculated. Of course, it is not possible to make a determination based on the sign of the output, and even if there is a change in the reflection coefficient of the antenna 3, it is not easy to make a determination.

For control of the reference noise source 24,
Since only the operation of setting the temperature calculated by the processing from the calculation result and the calibration data is performed, it is not necessary to operate the noise temperature of the reference noise source 24 many times as in the balance method. Shortening is possible. if,
If the temperature detection by the temperature sensor 5 in the balloon 4 is possible during the heating, the control of the reference noise source 24 can be performed during the heating. In that case, the measurement time can be further reduced.

Therefore, for example, in heating treatment such as hyperthermia, the off time of the heating output accompanying the temperature measurement can be kept short, and highly accurate temperature control can be ensured by the merit of the balance method geometry.

FIGS. 3 and 4 show a second embodiment of the present invention. FIG. 3 shows the overall configuration of the device. The basic configuration is similar to that of the first embodiment described above, but the temperature on the outer surface side of the balloon 4, that is, A temperature sensor 35 capable of measuring the temperature of the surface of the living body 1 is added. In addition, the microwave receiver 9
Are configured as shown in FIG. This configuration is the same as that of the first embodiment except for the following points.

A coaxial switch 41 controlled by the temperature measurement controller 15 is provided between the circulator 22 and the reference noise source 24. The reference noise source 24 has two reference noise sources 24a and 24b, which are selected by switching the coaxial switch 41. Both of these reference noise sources 24a and 24b are controlled by the temperature measurement control unit 15.

The operation of the microwave receiver 9 is different from that of the first embodiment in that the coaxial switch 41
Only the reference noise sources 24a and 24b are switched, and the other parts are the same. next,
This operation and its operation will be described. The measurement of the calibration data is the same as that of the first embodiment.

The actual measurement and the heating action are shown as follows.
First, the probe 2 is attached to the living body 1 to be heated and measured. The coaxial switch 7 is controlled by a signal from the heating control unit 16.
Switch to connect the heating oscillator 8 side. The output of the heating oscillator 8 is turned on by a signal from the heating control unit 16. The heating output may be fixed, but if it is variable, this output value is also controlled by the heating control unit 16.

If the temperature can be measured by the temperature sensor 35 during the heating, the temperature can be detected by the temperature sensor 35 and input to the heating control unit 16 via the thermometer 14. At this time, it is possible to confirm whether or not the surface of the living body 1 has exceeded the dangerous temperature based on the temperature of the temperature sensor 35. Further, the detected temperature, the heating output value, the integrated energy amount, and the like are displayed on the heating display unit 20.

After heating for a certain period of time, the output of the heating oscillator 8 is first turned off by a signal from the heating control unit 16. Next, the coaxial switch 7 is switched, and the connection to the microwave receiver 9 is switched. Temperature measurement controller 15
First, the temperature sensor 5 that measures the liquid temperature in the balloon 4 or the temperature detection data that can be detected by both the temperature sensors 5 and 35 is input via the thermometer 14.

The noise temperature of the microwave radiated from the surface of the living body 1 or the inside of the living body 1 indicates that the balloon 4
Since the noise is attenuated in the interior or inside the balloon 4 and in the inner surface layer of the living body 1 and the noise of the temperature of that part is added by the amount of the attenuation, the luminance temperature from the surface or the inside of the living body 1 as a reference The temperature at which the output is received by the antenna 3 is determined using the temperature inside the balloon 4 by using the temperature inside the balloon 4.
The arithmetic function of 5 performs the calculation.

The calculation result is called a reference antenna temperature. This reference antenna temperature has a lower limit and an upper limit.
The calculation method in this case includes a method of approximating the radiation direction of the antenna 3 so as to be perpendicular to the axis of the antenna 3 and a method of measuring a near-field radiation field distribution of the antenna 3 and using the measured data as data. And how to do it. When using the temperature sensor 35 for the temperature distribution model,
As the temperature of the inner surface layer of the living body 1, the temperature detected by the temperature sensor 35 can be used. In any method, the attenuation constant of the liquid in the balloon 4 and the attenuation constant of the tissue of the living body 1 need to be input in advance to the memory of the temperature measurement control unit 15. In this calculation, if the temperature can be measured by the temperature sensors 5 and 35 even during the heating, the temperature measurement control unit 15 may read this temperature and perform the calculation in advance during the heating. It is possible.

When the reference antenna temperature is determined, the temperature measurement control unit 15 switches the coaxial switch 41 in the microwave receiver 9 to the reference noise source 24a side, and the reference noise source 24a
Is set and controlled to a noise temperature that balances when the lower reference antenna temperature obtained by the above calculation is input. As an actual calculation method, the correlation between T _W and T _ref in the calibration data is corrected by the difference between the cable temperatures measured by the temperature sensors 5 and 35 when the calibration data is measured and when the calibration data is actually measured. What is necessary is just to substitute the lower-limit reference antenna temperature into T _W of the corrected correlation. Then, the noise temperature _Tref of the reference noise source 24 that should be balanced with the lower limit reference antenna temperature can be calculated.

After controlling the reference noise source 24a to the noise temperature calculated by the above calculation, the output of the microwave receiver 9 is input to the temperature measurement control unit 15 so that the actual reception brightness temperature at the antenna 3 is lower than the lower limit. It is determined whether the temperature is higher or lower than the reference antenna temperature. If the temperature is lower than the lower-limit reference antenna temperature, this is notified to the heating controller 16 by a signal.
Then, the heating control unit 16 switches the coaxial switch 7 to return to the connection to the heating oscillator 8 side, turns on the output of the heating oscillator 8, performs slightly longer heating, and performs the next time heating. The temperature is then measured. If so, the reference noise source 24 is set to a noise temperature that balances with the upper reference antenna temperature. This does not cause any problem even if it is set before the output result of the microwave receiver 9 is viewed, but it is better as the measurement time.

After the setting, the coaxial switch 41 is switched to the connection to the reference noise source 24b, and the upper limit reference antenna temperature is compared with the actual reception luminance temperature. If the received brightness temperature is higher than the upper reference antenna temperature, the process waits while measuring the temperature until the received brightness temperature decreases to the lower reference antenna temperature. If it is low, switch the coaxial switch 7, turn on the heating oscillator 8, and perform a slightly shorter heating,
The next temperature measurement is performed thereafter.

According to the present embodiment, the first
In addition to the advantages of the first embodiment, since the heating temperature is given a hysteresis, more stable heating can be performed than in the first embodiment. Further, when the heating output is variable, controlling the heating output as well as the heating time of the subsequent one cycle between when the temperature is equal to or lower than the lower limit reference antenna temperature and when the temperature is equal to or higher than the lower limit reference antenna temperature enables more stable heating. .

The provision of the temperature sensor 35 outside the balloon 4 has the advantages that the dangerous temperature on the surface of the living body 1 can be detected and the accuracy of estimating the temperature inside the body cavity 1 from the brightness temperature is improved. is there.

The two reference noise sources 24a and 24b
Is not set as the upper limit reference antenna temperature and the lower limit reference antenna temperature, and one is set as the reference antenna temperature and the other is set as the dangerous antenna temperature, thereby performing the first heating control.
It is also possible to change to a system in which overheating protection is performed in the same manner as in the embodiment.

FIG. 5 shows a third embodiment of the present invention. The basic configuration of this apparatus is the same as that of the first embodiment described above, except for the configuration of the tip of the probe 2.

That is, an antenna 3 is provided at the tip of the probe 2 inserted into the living body (body cavity) 1, and the temperature sensor 5 is provided immediately near a portion of the antenna 3 from which power is radiated most. Further, the antenna 3 and the temperature sensor 5
Are enclosed by a silicon member 51 such as a silicon tube or a silicon material. Here, the silicon member 51 is used for flexibility and compatibility with the living body 1,
This is because the surface is selected from appropriate smoothness or the like, and this material may be changed depending on the application.

In this embodiment, since there is no balloon, a water supply / drainage line is not required. In this embodiment, the case where the surface layer of the living body 1 has already been affected by cancer or the like and there is no need to cool the surface layer, or the diameter of the living body cavity is small, and insertion with a probe with a balloon is impossible. Can be used in such cases.

In this embodiment, the temperature distribution in the vicinity of the antenna 3 monotonously decreases depending on the distance from the antenna 3. Therefore, if the function of the decrease curve is estimated from experience, the surface temperature (temperature sensor 5 It is also possible to determine the function (that is, the estimated temperature distribution) from the two of the temperature detected by (1) and the actual received luminance temperature.

In the above-described three embodiments, only a combination with a heating device is described. However, the present invention is not limited to this, and the invention is also effective with a single temperature measuring device. It is generally said that the temperature of the affected part of the living body is higher than that of the normal part. If the reference antenna temperature is set based on the temperature of the normal part, the affected part can be easily detected.

[0065]

According to the non-invasive temperature measuring device of the present invention,
At the time of measurement, since an operation for balance is not required, the measurement time is greatly reduced. The reference brightness temperature can be measured without being affected by the reflection coefficient of the interface between the antenna and the object to be measured, and the comparison result affects the reflection coefficient as to whether the measured value is equal to or higher than the reference brightness temperature. Can be sought without being done.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of the overall configuration of a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a configuration of a microwave receiver according to the first embodiment of the present invention.

FIG. 3 is an explanatory view of the overall configuration of a second embodiment of the present invention.

FIG. 4 is a diagram illustrating a configuration of a microwave receiver according to a second embodiment of the present invention.

FIG. 5 is an explanatory diagram of the overall configuration of a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... living body (body cavity), 2 ... probe, 3 ... antenna, 4 ...
Balloon, 5 ... temperature sensor, 9 ... microwave receiver, 8
... heating oscillator, 15 ... temperature measurement control unit, 16 ... heating control unit, 21 ... Dickey switch, 22 ... circulator, 23 ... isolator, 24 ... reference noise source, 26 ...
Mixer, 31: Synchronous signal generator, 32: Lock-in amplifier, 35: Temperature sensor.

Continuation of the front page (56) References JP-A-57-55124 (JP, A) JP-A-54-7789 (JP, A) JP-A-62-192136 (JP, A) JP-A-59-164955 (JP, A) , A) Real opening 58-101654 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61B 5/00 101 A61B 5/04 G01J 5/46 G01K 1/02 G01K 7 / 30

Claims (1)

(57) [Claims] 1. A non-invasive method for measuring a temperature of an object to be measured by receiving a thermal noise electric wave radiated from an object to be measured and adjusting a reference noise temperature of a reference noise source in accordance with the thermal noise electric wave. Means for determining a reference noise temperature that can be balanced with a reference luminance temperature corresponding to a target temperature of an object to be measured, and adjusting a reference noise source so as to emit the reference noise temperature; and a value of the measured luminance temperature. And a means for comparing the value of the reference luminance temperature with the value of the reference luminance temperature, and outputting a result of the comparison.