JP2878735B2 - Internal temperature measurement device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention measures the temperature of a diseased part deep inside the body from outside the body at the time of thermal treatment of a diseased part in the body without contacting a living body, for example, to perform appropriate diagnosis and treatment. The present invention relates to an improvement in a body temperature measurement device used for performing the measurement.

[Prior Art] Generally, a so-called non-invasive body temperature measuring device that measures the temperature of a diseased part deep inside the body from outside the body in a non-contact state is a microwave-radiometric system (for example, Japanese Patent Publication No. 60-46648). Gazettes) are known. It measures the microwave component of the thermal noise power emitted by living tissue according to the principle of black body radiation as the brightness temperature of the living body, processes the data, and distributes the body temperature as a function of the distance (depth) from the body surface. Is estimated. In this case, the body temperature measurement device is connected to an antenna unit that receives an electromagnetic wave radiated outside the body according to the temperature of each part in the living body via a coaxial cable, and is transmitted through the coaxial cable. And a radiometer main body for performing data processing based on the received signal and detecting a temperature of a measurement unit in a living body.

By the way, electromagnetic waves radiated outside the body from a living tissue are generally extremely weak, so in order to stably detect the temperature of a measuring section in a living body using this type of body temperature measuring device, it is necessary to reduce measurement errors. It is necessary to take measures.

FIG. 6 shows a body temperature measuring device which has taken this kind of countermeasure.
Is a coaxial cable connecting between the radiometer main body 1 and the antenna section 2. In this case, an extremely weak microwave (measured part temperature Tt) radiated from a living tissue such as a human body is received by the antenna unit 2, and a received signal from the antenna unit 2 is transmitted via the coaxial cable 3 to the radiometer main unit 1. Is input to the Dicke switch 4. The Dicke switch 4 turns on and off according to an output signal from the local oscillator 5. The frequency signal output from the Dicke switch 4 is input to the circulator 6. The output frequency signal (reference noise temperature T _R ) from the reference noise source 7 is input to the circulator 6. The circulator 6 outputs a noise signal represented by the following equation according to the on / off operation of the Dicke switch 4.

During ON operation: Tt (1-R) + T R · R Off Operation: T _R wherein, R is the reflectivity at the boundary with the biological (target subject) and the antenna portion 2.

Further, the noise signal output from the circulator 6 is input to a high frequency (RF) amplifier 9 via an isolator 8, amplified, and input to a mixer 10. An output signal from a local oscillator 11 is input to the mixer 10.
Then, the signal is modulated by the mixer 10 to an intermediate frequency (IF). The intermediate wave signal output from the mixer 10 is input to the intermediate wave amplifier 12 and amplified, then rectified by the detector 13 and supplied to the lock-in amplifier 14. An output signal from the local oscillator 5 is input to the lock-in amplifier 14. The lock-in amplifier 14 outputs a voltage proportional to the difference between the two. Further, the output signal from the lock-in amplifier 14 is
Is input to The reference noise source 7 is connected to the control unit 15. The control unit 15 controls the reference noise source 7 so that the output signal from the lock-in amplifier 14 becomes zero.
Output by controlling the frequency signal (see noise temperature _{T R), Tt (1-} R) + T R · R = T R ∴Tt = T R , and the noise from the received signal received by the antenna unit 2 from With the components removed, the temperature of the living body (measured part) is detected.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional configuration, there was a problem that noise such as attenuation and thermal noise generated by the coaxial cable 3 at the time of measuring the body temperature could not be removed.
In this case, since the body temperature measuring device is used indoors,
There has been a problem that noise values such as attenuation of the coaxial cable 3 itself and thermal noise also fluctuate according to a change in the measurement environment such as a change in room temperature. Therefore, at the time of measuring the temperature inside the body, there is a possibility that the measured temperature obtained in response to a change in the measurement environment such as a change in the room temperature may fluctuate.

Further, a cable temperature measuring means for measuring the temperature of the coaxial cable 3 is provided, and correction data for removing noise such as attenuation and thermal noise generated by the coaxial cable 3 is calculated based on the measured temperature, and the body temperature is measured. It is also considered that by performing an operation of correcting data with the correction data, noise such as attenuation and thermal noise generated by the coaxial cable 3 is removed, and measurement accuracy of the temperature in the body is increased. However, in this case, another temperature measuring device for measuring the temperature of the coaxial cable 3 is required, so that the configuration of the whole body temperature measuring device is complicated, and there is a problem that the cost is increased. Further, since the above-mentioned correction data changes due to the temperature fluctuation of the coaxial cable 3, a troublesome operation of calculating the above-mentioned correction data is required every time the body temperature is measured. Was.

The present invention has been made with a focus on the above circumstances, and prevents the measured temperature obtained in response to a change in the measurement environment, such as a change in the indoor temperature, from being measured when measuring the temperature inside the body, thereby improving the accuracy of measuring the temperature inside the body. And a body temperature measuring device that can quickly measure the body temperature by eliminating the troublesome work of calculating the correction data of the body temperature every time the body temperature is measured. It is intended for.

[Means for Solving the Problems] The present invention relates to an antenna unit for receiving an electromagnetic wave radiated outside the body according to the temperature of each part in a living body, and connected to the antenna unit via a cable, and via the cable. A body temperature measuring device comprising: a radiometer body for detecting a temperature of a measuring portion in a living body based on a received signal transmitted; provided with a cable temperature control means for maintaining a temperature of a cable at a constant reference temperature state It is.

[Function] By maintaining the temperature of the cable at a constant reference temperature state during the measurement of the internal temperature, the measured temperature obtained even when the measurement environment changes such as a change in the indoor temperature during the measurement of the internal temperature is appropriate. By preventing the fluctuation from the value, the measurement accuracy of the internal temperature is improved, and the correction value of the measurement data is set in advance according to the reference temperature of the cable, so that the correction of the internal temperature is performed every time the internal temperature is measured. This eliminates the need for cumbersome work of calculating data, and quickly measures body temperature.

[Embodiment] Hereinafter, a first embodiment of the present invention will be described with reference to FIG. 1 and FIG.

That is, in this embodiment, a heater 21 for heating the coaxial cable 3 is provided in the coaxial cable 3 in the body temperature measuring device as shown in FIG. 6, and a heater temperature controller 22 is connected to the heater 21. A cable temperature control means 23 for maintaining the temperature of the coaxial cable 3 at a constant reference temperature state by a temperature control unit 22 is provided. In this case, the coaxial cable 3 is provided with a first insulating layer 25 around a center conductor 24 as shown in FIGS. 1 and 2, and a substantially tubular outer layer around the first insulating layer 25. A second insulating layer 27 is provided around the conductor 26 and the outer conductor 26, and a substantially tubular heater 2 is provided around the second insulating layer 27.
1. Further, a third insulating layer 28 is provided around the heater 21. The heater 21 is formed of, for example, an infrared heater, a nichrome wire heater, a magnetic wire heater, or the like.

Therefore, in the above configuration, the heater 21 is energized at the time of measuring the body temperature, the coaxial cable 3 is heated by the heater 21, and the heating state of the coaxial cable 3 by the heater 21 is controlled by an appropriate heater temperature control unit 22. By controlling, the temperature of the coaxial cable 3 is maintained at a predetermined constant reference temperature state. In this case, the temperature of the coaxial cable 3 is always maintained at a predetermined constant reference temperature state even when the measurement environment changes, such as a change in the room temperature, when measuring the body temperature. The influence of noise, such as attenuation and thermal noise, caused by the coaxial cable 3 added to the received signal transmitted from the antenna unit 2 to the radiometer main body 1 through the coaxial cable 3 can always be kept in a constant reference state. Therefore, in a state where the temperature of the coaxial cable 3 is maintained at the reference temperature state, the influence of noise such as attenuation and thermal noise due to the coaxial cable 3 added to the received signal transmitted to the radiometer main body 1 through the coaxial cable 3. By measuring the correction data in advance and obtaining the correction data, the correction data can be always used in common during the measurement of the body temperature regardless of a change in the measurement environment such as a change in the room temperature. Therefore, even when a change in the measurement environment such as a change in the room temperature occurs during the measurement of the body temperature, the measurement temperature obtained by the radiometer main body 1 is corrected based on the common correction data, thereby obtaining the temperature. Since the measured temperature to be measured can be prevented from fluctuating from an appropriate value, the measurement accuracy of the body temperature can be improved as compared with the related art. Furthermore, the troublesome operation of calculating the correction data of the internal temperature every time the internal temperature is measured as in the related art can be eliminated, and the internal temperature can be measured quickly.

FIG. 3 shows a second embodiment of the present invention.

This is achieved by disposing a balloon 31 around the antenna section 2, a water supply channel 32 for supplying hot water into the balloon 31 around the coaxial cable 3, and a drainage of hot water in the balloon 31 around the water supply channel 32. A cable temperature control section for providing a hot water temperature control section on the side of a water supply pump for supplying hot water to the water supply path 32, and maintaining the temperature of the coaxial cable 3 at a constant reference temperature state by the hot water temperature control section. Means 23 are provided. Also in this case, the temperature of the coaxial cable 3 can be maintained at a predetermined constant reference temperature state when measuring the body temperature, as in the first embodiment, so that the same effect as in the first embodiment is obtained. be able to.

4 and 5 show examples of disclosure.

FIG. 4 shows a measurement error reducing circuit in the radiometer main body 1 when the reflectance R at the boundary between the living body (measured part) and the antenna part 2 is substantially zero. In this case, the output frequency signal (reference noise temperature) from the reference noise source 7 in the circuit of FIG.
T _R) is inputted to the Dicke switch 4, it is possible to omit the circulator 6 the circuit of Figure 6, it is possible to simplify the configuration.

5 shows an RF amplifier 41 interposed between the antenna unit 2 and the coaxial cable 3 shown in FIG. 4, and an RF amplifier 42 interposed between the reference noise source 7 and the Dicke switch 4. In this case, G ₂ a gain of G _1, RF amplifier 42 the gain of the RF amplifier 41, by setting the attenuation coaxial cable 3 as G ₁ × A = G ₂ When A, the antenna section 2 The difference between the temperature and the reference noise temperature from the reference noise source 7 can be taken out as the output of the lock-in amplifier 14 in proportion, and the influence of thermal noise on the coaxial cable 3 can be reduced.
Therefore, in this case, the received signal output from the antenna unit 2 is amplified by the RF amplifier 41 and
The level of noise such as attenuation due to heat and thermal noise
Can be made sufficiently small to be negligible compared to the level of the received signal output from the antenna, so that the received signal from the antenna unit 2 transmitted through the coaxial cable 3 is affected by attenuation by the coaxial cable 3 and thermal noise. Can be reduced.

When the antenna section 2 is mounted on the intracavity probe, the RF amplifier 41 may be downsized using a high dielectric substrate. Further, in the case of a board-type antenna such as a microstrip antenna (MSA), miniaturization can be achieved by mounting the antenna section 2 and the RF amplifier 41 on the same board.

It should be noted that the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[Effects of the Invention] According to the present invention, the cable temperature control means for maintaining the temperature of the cable at a constant reference temperature state is provided. The obtained measurement temperature can be prevented from fluctuating and the measurement accuracy of the body temperature can be improved, and at the time of measurement of the body temperature, the troublesome work of correcting the measurement data of the body temperature is not required every time. The body temperature can be measured.

[Brief description of the drawings]

1 and 2 show a first embodiment of the present invention. FIG. 1 is a schematic configuration diagram showing a main part configuration of a body temperature measuring device, FIG. 2 is a perspective view thereof, and FIG. FIG. 4 is a schematic configuration diagram of a main part showing a second embodiment of the present invention, FIGS. 4 and 5 show disclosure examples, FIG. 4 is a schematic configuration diagram of the entire apparatus,
FIG. 5 is a schematic configuration diagram of a main part, and FIG. 6 is a schematic configuration diagram of an entire apparatus showing a conventional example. 1. Radiometer body, 2. Antenna part, 3. Coaxial cable, 23 Cable temperature control means.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-22636 (JP, A) JP-A-1-244321 (JP, A) JP-A-54-113381 (JP, A) (58) Investigation Field (Int.Cl. ⁶ , DB name) G01J 5/50 A61B 5/00

Claims (1)

(57) [Claims] An antenna for receiving an electromagnetic wave radiated outside the body in accordance with the temperature of each part in a living body, and connected to the antenna via a cable and based on a received signal transmitted via the cable. A radiometer main body for detecting the temperature of the measuring part in the living body, wherein a cable temperature control means for maintaining the temperature of the cable at a constant reference temperature state is provided. Temperature measurement device.