JPH10272107A - Eardrum thermometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a vibration and a sound which reach the eardrum through an infrared derivative, in an eardrum thermometer wherein the infrared derivative, which leads infrared rays emitted from the eardrum, and the led-out infrared rays are passed a chopper and cast on a radiation temperature detector, by using a liquid crystal chopper for the chopper. SOLUTION: An infrared ray fiber 3 and a pyroelectric sensor 4 are attached to a temperature measuring box 2 which is installed in a headphone type ear pad, and the infrared fiber 3 is extended from the ear hole of a subject to be measured to a depth being closing to the eardrum along an external acoustic meatus. In the temperature measuring box 2, a thermistor 14 is provided, and by the thermistor 14, temperature atmospheres of a liquid crystal chopper 8 and a pyroelectric sensor 4 are measured, and heat is released from a radiating plate 16 by controlling a Peltier 15 based on the measured temperature information, and the temperature atmospheres are adjusted. The emitted infrared rays which are led out from the infrared ray fiber 3 are led to the pyroelectric sensor 4 through the liquid crystal chopper 8, and the radiation temperature of the eardrum 7 is accurately caught, an the output signal is signal-processed, and led to a display device, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eardrum thermometer for measuring the temperature of an eardrum in a non-contact manner.

[0002]

2. Description of the Related Art A radiation thermometer as shown in FIG. 3 is known as a radiation thermometer for measuring the temperature of an eardrum in a non-contact manner. That is, the thermal infrared rays generated from the eardrum are introduced into and guided by the infrared fiber 51, are extracted through the infrared fiber 51, and are incident on the pyroelectric sensor 53 as intermittent light by the mechanical chopper 52. The temperature is measured based on the detection signal by the above.

[0003]

However, when measuring the temperature of the eardrum, the body of the eardrum thermometer may be put on the ear,
Since it was necessary to hold it near the ear, the vibration of the mechanical chopper was transmitted to the ear and the sound was heard in the ear, which was uncomfortable for the subject. In particular, when the infrared fiber was inserted near the eardrum, the vibration of the mechanical chopper was transmitted to the vicinity of the eardrum via the infrared fiber, so that the vibration was large.

Also, in the case of a mechanical chopper, it is necessary to provide a predetermined interval between each of the tip of the infrared fiber and the pyroelectric sensor, so that external infrared rays are easily taken in, resulting in a detection error. Further, thermal energy generated from the motor affects the sensitivity of the pyroelectric sensor, resulting in a detection error.

It is an object of the present invention to provide a tympanic thermometer capable of accurately detecting the temperature of an eardrum without causing discomfort to a subject.

[0006]

SUMMARY OF THE INVENTION The present invention is directed to an eardrum thermometer that guides infrared radiation emitted from an eardrum and infrared light derived from the infrared derivative to pass through a chopper and enter a radiation temperature detector. In addition, by using a liquid crystal chopper as the chopper, vibration and sound generated from the chopper are eliminated, and vibration and sound transmitted to the eardrum through the infrared derivative are suppressed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a schematic configuration diagram of an embodiment of an eardrum thermometer according to the present invention. In the figure, 1 is a support member, 2 is a temperature measurement box, 3 is an infrared fiber, 4 is a pyroelectric sensor,
5 is a signal output line, 6 is an ear canal, 7 is an eardrum. In addition,
Since light near normal temperature has a peak in the wavelength band of 10 microns, the infrared fiber 3 may be, for example, a chalcogenide glass fiber (NTEG fiber from NOG).
Further, as the pyroelectric sensor 4, a DLATGS crystal pyroelectric sensor manufactured by slicing a DLATGS single crystal exhibiting stable high sensitivity in a 10-micron band is used. Note that a pyroelectric sensor using a LiTaO ₃ crystal or the like may be used.

The eardrum thermometer of this embodiment incorporates a temperature measurement box 2 in an ear pad of a headphone-type support member 1, and the temperature measurement box 2 includes an infrared fiber 3, a pyroelectric sensor 4, The infrared fiber 3 is inserted from the ear hole of the subject along the external auditory canal 6 to a depth close to the eardrum 7. It can be kept in a non-contact state with the eardrum 7. The signal output line 5 is also drawn out, and the measured eardrum temperature data is guided as an electric signal to an external display device (not shown) or a controller of a medical device to be used.

In this embodiment, an infrared fiber is used, but any member may be used as long as it guides infrared light from the tip of the probe to the temperature measurement box 2, and may be a glass fiber or a plastic fiber.

FIG. 2 is an internal configuration diagram of the temperature measuring box shown in FIG. In the figure, the same parts as those in FIG. 8 is a liquid crystal chopper, 9 is a sensor cap for holding the pyroelectric sensor, and 10 is a stem for holding the sensor cap.

Reference numeral 11 denotes a cap surrounding the pyroelectric sensor and has a hole through which infrared rays pass, and cuts off infrared rays other than those derived from the infrared fiber. Since this hole is sealed by the pyroelectric sensor, the internal temperature atmosphere is hardly affected by the outside air.

A thermistor 14 measures the temperature atmosphere of the liquid crystal chopper 8 and the pyroelectric sensor 4.
The Peltier 15 is controlled based on the temperature information to release heat from the radiator plate 16 and adjust the temperature atmosphere of the pyroelectric sensor 4. Therefore, by keeping the temperature atmosphere of the pyroelectric sensor 4 constant, the measurement sensitivity of the pyroelectric sensor can be kept constant. Reference numeral 12 denotes a cover for protecting the liquid crystal chopper, the pyroelectric sensor and the like, and reference numeral 13 denotes a metal tube inserted into the cover and guiding infrared rays to the liquid crystal chopper.

The liquid crystal chopper 8 is a modulation element of a type that performs modulation in the infrared region using the electro-optic effect of ferroelectric liquid crystal.
A device that performs opening / closing drive (chopping) at a modulation frequency of Hz is employed, which is already known. The liquid crystal chopper 4 is necessary when the pyroelectric sensor 4 is used as a radiation temperature detector. Pyroelectric sensor 4
Is a differential type sensor for detecting a temperature change. Therefore, a liquid crystal chopper 8 is installed in front of the pyroelectric sensor 4 to forcibly switch the input radiant energy, so that the background temperature and the temperature of the eardrum 7 The difference has been detected.

The radiated infrared rays derived from the infrared fiber 3 are guided to the pyroelectric sensor 4, and the radiation temperature of the eardrum 7 is accurately detected by the pyroelectric sensor 4. The temperature information processed by the signal processing circuit is guided to an external display device or the like via a signal output line 5 and used.

In the above-described embodiment, the temperature measurement box 2 is incorporated in the ear pad of the headphone-type support member 1 and is supported and fixed to the head of the person to be measured. Not limited to headphone type.
The support member only needs to maintain a constant positional relationship between the distal end of the infrared fiber 3 and the eardrum 7 in a state where the distal end of the infrared fiber 3 is inserted into the ear canal 6. For example, the temperature measurement box 2 can be supported by being fitted in an ear hole like an earphone, or supported on an auricle like a hearing aid or an eyeglass. Alternatively, the infrared fiber 3 may be formed into a rod-like body such as an earpick, and the position of the infrared fiber 3 may be held by the hand of the measurer or the subject.

[0017]

As is apparent from the above description, according to the present invention, the infrared light guided to the infrared fiber is chopped by the liquid crystal chopper instead of the conventional mechanical chopper and detected by the pyroelectric sensor. Therefore, no noise or vibration is generated, and even if the sound is held near the ear, the vibration or sound is not transmitted to the eardrum via the infrared fiber, so that the discomfort of the subject due to the measurement can be reduced.

Further, in the mechanical chopper, since the chopper rotates, it is necessary to keep a predetermined distance from the infrared fiber or the pyroelectric sensor, and even the infrared light entering from the gap enters the pyroelectric sensor, resulting in a detection error. However, in the present invention, since the gap between the tip of the infrared fiber, the liquid crystal chopper, and the pyroelectric sensor is narrowed, infrared rays from the outside are hardly taken in, and the detection error can be reduced.

Further, in the case of the mechanical chopper, the heat generated by the motor affects the sensitivity of the pyroelectric sensor. However, since the liquid crystal chopper itself does not generate heat, the detection error can be reduced.

Further, since the liquid crystal chopper is lighter than the mechanical chopper, the weight of the whole apparatus can be reduced and the portability can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of an eardrum thermometer of the present invention.

FIG. 2 is an internal configuration diagram of the temperature measurement box shown in FIG.

FIG. 3 is an internal configuration diagram of a conventional temperature measurement box.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Support member 2 ... Temperature measuring box 3 ... Infrared fiber 4 ... Pyroelectric sensor 5 ... Signal output line 6 ... Europe ear canal 7 ... Eardrum 8 ... Liquid crystal chopper 14 ... Thermistor

Claims (1)

[Claims] 1. An eardrum thermometer, wherein infrared light radiated from an eardrum is taken out via an infrared derivative, and the temperature of the eardrum is detected by being incident on a radiation temperature detecting means as intermittent light by a chopper. An eardrum thermometer characterized by using a liquid crystal chopper as the device.