JP2022180677A - Blood sugar measuring device - Google Patents

Abstract

To reduce the size of a blood sugar measuring device for noninvasively measuring a blood sugar level, reduce the cost of the blood sugar measuring device, and increase the output of a light source provided in the blood sugar measuring device.SOLUTION: A blood sugar measuring device 1 is provided with infrared radiators 11, 12 and a detector 41. Each of the infrared radiators has a radiation surface. The infrared radiator is provided with a metamaterial. The infrared radiator emits infrared heat from the radiation surface. The peak wavelength of infrared radiation depends on the structure of the metamaterial. The detector detects an amount that reflects the amount of infrared radiation absorbed by glucose in a living body.SELECTED DRAWING: Figure 1

Description

The present invention relates to a blood sugar level measuring device.

If diabetes is treated, insulin injections are given. When insulin injections are given, blood glucose measurements are taken. Blood glucose measurements are taken to determine the timing of insulin injections and the effect of therapy.

When a blood sugar level is measured, blood is collected by sticking a needle into the human body until the tip of the needle reaches the inside of the blood vessel. Also, the collected blood is brought into contact with the specimen chip. Consumables such as needles and sample chips are discarded each time a blood glucose level is measured. However, the act of sticking the needle into the human body until the tip of the needle reaches the inside of the blood vessel is invasive. For this reason, the act involves pain and the risk of contracting an infection. Moreover, discarding consumables such as needles and sample chips each time a blood glucose level is measured causes the problem of having to spend a large amount of money on consumables such as needles and sample chips. The annual cost for consumables such as needles and sample chips reaches about 200,000 yen in Japan. These problems also impede the measurement of blood sugar levels for prevention of diabetes or improvement of blood sugar levels.

Minimally invasive measurement of blood glucose level is also being considered. When the blood glucose level is measured minimally invasively, interstitial fluid is collected by inserting a needle into the human body until the tip of the needle reaches the skin. The tip of the needle need not reach into the blood vessel. Also, the interstitial fluid that has been collected is incorporated into the patch. Also, the glucose concentration in the ingested interstitial fluid is measured. Consumables such as needles and patches are replaced every two weeks. However, the act of sticking the needle into the human body until the tip of the needle reaches the skin also entails the risk of contracting an infectious disease. Moreover, exchanging consumables such as needles and patches every two weeks raises the problem of having to spend the cost of consumables such as needles and patches. These problems also impede the measurement of blood sugar levels for prevention of diabetes or improvement of blood sugar levels.

Therefore, non-invasive measurement of blood sugar level is also being considered. When the blood glucose level is measured non-invasively, the human body is irradiated with infrared rays. Also, the intensity of the infrared rays coming from the human body is detected while the infrared rays are being irradiated to the human body. Further, the glucose concentration in the interstitial fluid is calculated from the absorption amount of infrared rays by glucose in the interstitial fluid. Pain and the risk of infection can be eliminated if the blood glucose level is measured non-invasively. Also, the cost spent on consumables can be eliminated. Therefore, if it becomes possible to noninvasively measure the blood sugar level, it will also be possible to measure the blood sugar level in order to prevent diabetes or improve the blood sugar level.

Patent Literature 1 discloses a blood glucose meter. In the blood glucose meter, a mid-infrared laser beam is irradiated onto the biological epithelium of a subject. Also, the diffusely reflected light of the laser light is detected by the photodetector. Also, the glucose concentration in the interstitial fluid is measured from the absorption by glucose. A light source that oscillates laser light includes a Q-switched Nd:YAG laser or the like and an optical parametric oscillator (OPO) (paragraphs 0021-0023).

Patent Literature 2 discloses a measuring device. In the measurement device, infrared light output from a Fourier transform infrared spectroscopy (FTIR) device undergoes attenuation corresponding to the infrared light absorption spectrum of the sample. Also, the attenuated light is detected by a detector. Also, the blood sugar level is measured using the absorption spectrum of glucose (paragraphs 0022-0023).

JP 2018-199080 A JP 2019-37752 A

Blood glucose level measuring devices that measure blood glucose levels non-invasively have problems such as being large in size, being expensive, and being difficult to increase the output of the light source and to improve the measurement accuracy. .

For example, in the blood glucose meter disclosed in Patent Document 1, the energy efficiency of the Q-switched Nd:YAG laser or the like is low, so the size of the power supply for supplying power to the Q-switched Nd:YAG laser or the like is large, and the Q-switched Nd : A cooling system for cooling the YAG laser or the like is required, and a cooling mechanism is required. Therefore, the blood glucose meter has problems such as a large size, high cost, and difficulty in increasing the output of the light source.

Moreover, in the measuring device disclosed in Patent Document 2, the size of the FTIR device is large, the energy efficiency of the FTIR device is low, and the cost of the FTIR device is high. For this reason, the measuring apparatus has problems such as a large size, high cost, and difficulty in increasing the output of the light source.

The present invention has been made in view of these problems. The present invention aims to reduce the size of a blood sugar level measuring device that measures blood sugar levels in a non-invasive manner, reduce the cost of the blood sugar level measuring device, and increase the output of a light source provided in the blood sugar level measuring device. aim.

The present invention relates to a blood sugar level measuring device.

A blood glucose measuring device comprises an infrared emitter and a detector.

The infrared radiator has a radiating surface. An infrared emitter comprises a metamaterial. An infrared radiator thermally radiates infrared rays from a radiation surface. The infrared peak wavelength is a wavelength according to the structure of the metamaterial.

A detector detects an amount that reflects the amount of infrared radiation absorbed by glucose in a living body.

According to the present invention, the amount of infrared radiation absorbed by glucose is determined using the infrared radiation thermally radiated by an infrared radiator that does not require a cooling system and has high energy efficiency. As a result, it is possible to reduce the size of the blood sugar measuring device that measures the blood sugar level in a non-invasive manner. Also, the cost of the blood sugar level measuring device can be reduced. Also, the output of the light source provided in the blood sugar level measuring device can be increased.

Objects, features, aspects and advantages of the present invention will become more apparent with the following detailed description and accompanying drawings.

1 is a cross-sectional view schematically illustrating the blood sugar level measuring device of the first embodiment; FIG. FIG. 3 is a cross-sectional view schematically illustrating an infrared radiator provided in the blood sugar level measuring device of the first embodiment; 5 is a graph showing an example of an absorbance spectrum of glucose and an infrared radiant intensity spectrum thermally radiated by an infrared radiator provided in the blood glucose level measuring devices of the first, second, and fifth embodiments. FIG. 4 is a perspective view schematically illustrating a heat radiation plate provided in the blood glucose level measuring devices according to the first to fifth embodiments; 4 is a graph showing an example of a radiant energy spectrum of infrared rays thermally radiated by an infrared radiator provided in the blood sugar level measuring device of the first embodiment and an example of a radiant energy spectrum of infrared rays thermally radiated by a normal infrared heater. FIG. 4 is a cross-sectional view schematically illustrating a blood sugar level measuring device according to a second embodiment; FIG. 7 is a cross-sectional view schematically illustrating an infrared radiator provided in the blood sugar level measuring device of the second embodiment; FIG. 10 is a cross-sectional view schematically illustrating a blood sugar level measuring device according to a third embodiment; FIG. 12 is a cross-sectional view schematically illustrating an infrared radiator provided in the blood sugar level measuring device of the third embodiment; 7 is a graph showing an example of an absorbance spectrum of glucose and an infrared radiant intensity spectrum thermally radiated by an infrared radiator provided in the blood sugar level measuring device of the third embodiment and the fourth embodiment. FIG. 11 is a cross-sectional view schematically illustrating a blood sugar level measuring device according to a fourth embodiment; FIG. 11 is a cross-sectional view schematically illustrating an infrared radiator provided in a blood glucose level measuring device according to a fourth embodiment; FIG. 11 is a plan view schematically illustrating an infrared radiator provided in a blood glucose level measuring device according to a fourth embodiment; FIG. 11 is a cross-sectional view schematically illustrating a blood sugar level measuring device according to a fifth embodiment; FIG. 11 is a cross-sectional view schematically illustrating an infrared radiator provided in a blood glucose level measuring device according to a fifth embodiment; FIG. 11 is a plan view schematically illustrating an infrared radiator provided in a blood glucose level measuring device according to a fifth embodiment; FIG. 11 is a cross-sectional view schematically illustrating a blood sugar level measuring device according to a sixth embodiment; FIG. 4 is a schematic diagram showing how an infrared transmitting filter FT is arranged in the middle of an infrared optical path from an infrared radiator 11 to a living body LB; FIG. 19 is a diagram showing changes in the infrared radiation spectrum due to the placement of the filter FT in the case shown in FIG. 18; FIG. 19 is a schematic diagram showing how the same filter FT as in FIG. 18 is arranged in the middle of the optical path of infrared rays emitted from a general infrared heater HT. FIG. 21 is a diagram showing changes in radiation spectrum due to the arrangement of filters FT in the case shown in FIG. 20; FIG. 11 is a perspective view schematically illustrating another example of a heat radiation plate provided in the blood glucose level measuring devices of the first to sixth embodiments; FIG. 11 is a perspective view schematically illustrating another example of a heat radiation plate provided in the blood glucose level measuring devices of the first to sixth embodiments; FIG. 11 is a perspective view schematically illustrating another example of a heat radiation plate provided in the blood glucose level measuring devices of the first to sixth embodiments;

1. First Embodiment 1.1 Configuration of Blood Glucose Level Measuring Device FIG. 1 is a cross-sectional view schematically illustrating a blood sugar level measuring device according to the first embodiment. FIG. 2 is a cross-sectional view schematically illustrating an infrared radiator provided in the blood sugar level measuring device of the first embodiment. FIG. 3 is a graph showing an example of an absorbance spectrum of glucose and an infrared radiant intensity spectrum thermally radiated by an infrared radiator provided in the blood sugar level measuring device of the first embodiment. In FIG. 3, the vertical axis is the absorbance and the radiant intensity. Also, the horizontal axis represents the wave number.

The blood sugar level measuring device 1 of the first embodiment illustrated in FIG. 1 is a wavelength independent type blood sugar level measuring device in which each of the infrared rays IR1 and IR2 irradiated to the living body LB has only one peak wavelength.

As shown in FIG. 1, the blood glucose level measuring device 1 includes an infrared radiator 11, an infrared radiator 12, an optical system 21, an optical system 22, a shutter 31, a shutter 32, a detector 41, a controller 51 and a calculator. 61.

Infrared radiators 11 and 12 thermally emit infrared rays IR1 and IR2, respectively. Infrared rays IR1 and IR2 have peak wavelengths λ1 and λ2, respectively. The peak wavelengths λ1 and λ2 are different from each other. Therefore, the infrared rays IR1 and IR2 have different peak wavelengths.

Optical systems 21 and 22 collect the thermally emitted infrared rays IR1 and IR2, respectively.

Shutters 31 and 32 open and close the optical paths of thermally emitted infrared rays IR1 and IR2, respectively.

The detector 41 detects an amount D that reflects the amount of absorption of the infrared rays IR1 and IR2 by glucose in the living body LB. In the first embodiment, detector 41 is an infrared detector. Also, the amount D to be detected is the intensity of the incoming infrared rays AIR arriving from the living body LB while the infrared rays IR1 and IR2 are being irradiated to the living body LB. The infrared detector is a photodiode. The infrared detector may be an infrared detector other than a photodiode. Also, in the first embodiment, the living body LB is a human body. The living body LB may be a living body other than a human body.

In the first embodiment, the infrared rays IR1 and IR2 are emitted to fingers or ears, for example. Detector 41 also detects the intensity of incoming infrared rays AIR coming from, for example, a finger or ear.

The calculator 61 calculates the blood sugar level from the detected amount D.

Infrared rays IR1 and IR2 penetrate into the skin. Therefore, from the detected quantity D, the concentration of glucose in the interstitial fluid within the skin can be obtained. The concentration of glucose in interstitial fluid correlates with blood glucose level. Therefore, the blood sugar level can be calculated from the detected amount D.

The controller 51 controls the infrared radiators 11 and 12 to cause the infrared radiators 11 and 12 to thermally radiate infrared rays IR1 and IR2, respectively. The controller 51 also controls the shutters 31 and 32 to open and close the optical paths of the infrared rays IR1 and IR2, respectively.

In the first embodiment, infrared radiators 11 and 12 are two infrared radiators. Also, infrared rays IR1 and IR2 are two infrared rays. Also, the optical systems 21 and 22 are two optical systems. Also, shutters 31 and 32 are two shutters. However, the number of infrared emitters, the number of infrared rays, the number of optics and the number of shutters may be increased or decreased.

1.2 Peak Wavelength of Infrared As shown in FIG. 3, the peak wavelength λ1 of infrared IR1 is the wavelength at which the absorbance of glucose is minimum. Infrared IR1 is used for calibration. The peak wavelength λ1 may be a wavelength other than the wavelength at which the absorbance of glucose is minimized. Also, the peak wavelength λ2 of the infrared rays IR2 is the wavelength at which the absorbance of glucose is maximized. Infrared IR2 is used for the measurement. The peak wavelength λ2 may be a wavelength other than the wavelength at which the absorbance of glucose is maximum.

1.3 Operation of Blood Glucose Level Measuring Device When the blood sugar level is calculated by the blood sugar level measuring device 1, the controller 51 causes the shutters 31 and 32 to close the optical paths of the infrared rays IR1 and IR2.

Controller 51 also causes infrared radiators 11 and 12 to start thermally emitting infrared rays IR1 and IR2 after the optical paths of infrared rays IR1 and IR2 are closed.

Further, the controller 51 causes the shutter 31 to open the optical path of the infrared rays IR1 after the infrared rays IR1 and IR2 are stabilized. As a result, the living body LB is irradiated with the infrared rays IR1. At this time, the infrared rays IR1 are focused on the surface of the living body LB by the optical system 21 .

Further, the controller 51 causes the shutter 31 to close the optical path of the infrared rays IR1 when the set time has passed since the optical path of the infrared rays IR1 was opened. As a result, the infrared rays IR1 are no longer emitted to the living body LB.

The detector 41 detects the intensity D of the incoming infrared rays AIR coming from the living body LB while the infrared rays IR1 are being irradiated to the living body LB.

Controller 51 calibrates blood sugar level measuring device 1 based on detected intensity D. FIG.

Further, the controller 51 causes the shutter 32 to open the optical path of the infrared rays IR2 after the blood glucose level measuring device 1 is calibrated. As a result, the living body LB is irradiated with the infrared rays IR2. At this time, the infrared rays IR2 are focused on the surface of the living body LB by the optical system 22 .

Further, the controller 51 causes the shutter 32 to close the optical path of the infrared rays IR2 when the set time has passed since the optical path of the infrared rays IR2 was opened. As a result, the infrared rays IR2 are no longer emitted to the living body LB.

Further, the controller 51 causes the infrared emitters 11 and 12 to stop thermally emitting the infrared rays IR1 and IR2 after the optical path of the infrared rays IR2 is closed.

The detector 41 detects the intensity D of the incoming infrared rays AIR coming from the living body LB while the infrared rays IR2 are being irradiated to the living body LB.

The calculator 61 calculates the blood sugar level from the intensity D detected.

1.4 Different Configurations of Multiple Infrared Radiator As shown in FIG. 1, infrared radiators 11 and 12 have radiation surfaces 11R and 12R, respectively. Infrared radiators 11 and 12 thermally radiate infrared rays IR1 and IR2 from radiation surfaces 11R and 12R, respectively.

Also, as illustrated in FIG. 1, infrared emitters 11 and 12 comprise metamaterials 111 and 121, respectively. Metamaterials 111 and 121 are disposed along emitting surfaces 11R and 12R, respectively.

Metamaterials 111 and 121 have different structures. The peak wavelengths λ1 and λ2 are wavelengths according to the structures of the metamaterials 111 and 121, respectively. Therefore, the peak wavelengths λ1 and λ2 are different from each other.

In the first embodiment, the metamaterials 111 and 121 are periodic structures comprising a plurality of pattern pieces periodically arranged in directions parallel to the radiation surfaces 11R and 12R, respectively. Also, the peak wavelengths λ1 and λ2 are wavelengths corresponding to the patterns of the periodic structures 111 and 121, respectively.

In the first embodiment, the radiating surfaces 11R and 12R are two groups of radiating surfaces. Metamaterials 111 and 121 are also two groups of metamaterials. However, the number of groups of emitting surfaces and the number of groups of metamaterials may be increased or decreased.

1.5 Configuration of Each of Plurality of Infrared Radiator As shown in FIG.

The heater 81 heats the thermal radiation plates 71A and 71B to supply heat to the thermal radiation plates 71A and 71B.

Thermal radiation plates 71A and 71B convert the supplied heat into infrared rays IRA and IRB, respectively, illustrated in FIG. The thermal radiation plates 71A and 71B thermally radiate infrared rays IRA and IRB, respectively.

As illustrated in FIGS. 1 and 2, the thermal radiation plates 71A and 71B have radiation surfaces 71AR and 71BR, respectively. Thus, infrared radiators 11 and 12 each have radiation surfaces 71AR and 71BR. Also, each of the infrared radiators 11 and 12 thermally radiates the infrared rays IRA and IRB from the radiation surfaces 71AR and 71BR, respectively. Radiation surfaces 71AR and 71BR of infrared radiator 11 constitute radiation surface 11R. Radiation surfaces 71AR and 71BR of infrared radiator 12 constitute radiation surface 12R. The infrared rays IRA and IRB emitted by the infrared radiator 11 constitute the infrared rays IR1. The infrared rays IRA and IRB emitted by the infrared emitter 12 constitute the infrared rays IR2.

Also, as illustrated in FIGS. 1 and 2, heat radiation plates 71A and 71B comprise metamaterials 71A1 and 71B1, respectively. To this end, each of infrared radiators 11 and 12 comprises metamaterials 71A1 and 71B1. Metamaterials 71A1 and 71B1 are disposed along emitting surfaces 71AR and 71BR, respectively. The metamaterials 71A1 and 71B1 provided in the infrared radiator 11 constitute the metamaterial 111 . The metamaterials 71A1 and 71B1 provided in the infrared radiator 12 constitute the metamaterial 121. FIG.

Metamaterials 71A1 and 71B1 have the same structure. The peak wavelengths of the infrared rays IRA and IRB are wavelengths corresponding to the structures of the metamaterials 71A1 and 71B1, respectively. Therefore, the peak wavelengths of the infrared rays IRA and IRB are the same wavelength.

In the first embodiment, the metamaterials 71A1 and 71B1 are periodic structures having a plurality of pattern pieces periodically arranged in a direction parallel to the radiation surfaces 71AR and 71BR, respectively. Also, the peak wavelengths of the infrared rays IRA and IRB are wavelengths corresponding to the patterns of the periodic structures 71A1 and 71B1, respectively.

In the first embodiment, the heat radiation plates 71A and 71B provided in each of the infrared radiators 11 and 12 are two heat radiation plates. Also, the infrared rays IRA and IRB thermally radiated by each of the infrared radiators 11 and 12 are two infrared rays. Also, the radiation surfaces 71AR and 71BR of each of the infrared radiators 11 and 12 are two radiation surfaces. Also, the metamaterials 71A1 and 71B1 provided in each of the infrared radiators 11 and 12 are two metamaterials. Also, the heater 81 is sandwiched between two heat radiation plates 71A and 71B. However, the number of heat radiation plates provided in each of the infrared radiators 11 and 12, the number of infrared rays thermally radiated by each of the infrared radiators 11 and 12, the number of radiation surfaces of each of the infrared radiators 11 and 12, and the number of metamaterials provided in each of infrared radiators 11 and 12 may be increased or decreased.

1.6 Optical System As illustrated in FIG. 1, optical systems 21 and 22 comprise parabolic mirrors 101 and 102, respectively. The optical systems 21 and 22 also include lenses 141 and 142, respectively.

As illustrated in FIG. 1, parabolic mirrors 101 and 102 have focal points 101F and 102F, respectively. Also, the parabolic mirrors 101 and 102 have reflecting surfaces 101R and 102R, respectively. Parabolic mirrors 101 and 102 also have rotational symmetry axes 101S and 102S, respectively.

Reflecting surfaces 101R and 102R are paraboloids of revolution formed by rotating parabolas about rotational symmetry axes 101S and 102S, respectively.

Infrared emitters 11 and 12 are positioned at focal points 101F and 102F, respectively.

The reflecting surfaces 101R and 102R reflect thermally emitted infrared rays IR1 and IR2, respectively. Since the infrared radiators 11 and 12 are arranged at the focal points 101F and 102F respectively, the reflected infrared rays IR1 and IR2 become parallel beams.

Lenses 141 and 142 collect the reflected infrared rays IR1 and IR2, respectively.

These allow the optical systems 21 and 22 to collect the thermally radiated infrared rays IR1 and IR2, respectively.

The radiation surfaces 71AR and 71BR of the infrared radiator 11 face a direction perpendicular to the direction in which the axis of rotational symmetry 101S extends, and face different directions. In the first embodiment, the radiation surfaces 71AR and 71BR of the infrared radiator 11 face in directions 180 degrees different from each other. Similarly, the radiation surfaces 71AR and 71BR of the infrared radiator 12 face in a direction perpendicular to the direction in which the axis of rotational symmetry 102S extends, and face in different directions. In the first embodiment, the radiation surfaces 71AR and 71BR of the infrared radiator 12 face in directions 180 degrees different from each other.

1.7 Heat Radiating Plate FIG. 4 is a perspective view schematically illustrating a heat radiating plate provided in the blood sugar level measuring device of the first embodiment.

As illustrated in FIG. 4, each of the heat radiation plates 71A and 71B comprises a substrate 151, a conductor layer 152, a dielectric layer 153 and a conductor pattern 154. FIG.

Conductive layer 152 , dielectric layer 153 and conductive pattern 154 are disposed on one major surface of substrate 151 . A dielectric layer 153 is disposed over the conductor layer 152 . A conductor pattern 154 is disposed over the dielectric layer 153 .

The conductor pattern 154 has a plurality of pattern pieces 161 . A plurality of pattern pieces 161 are arranged in a matrix. A plurality of pattern pieces 161 may be arranged in a non-matrix pattern.

The substrate 151 is composed of _SiO2 . Substrate 151 may be made of a material other than SiO ₂ . The conductor layer 152 is composed of Au. The conductor layer 152 may be made of a material other than Au. Dielectric layer 153 is composed of Al ₂ O ₃ . Dielectric layer 153 may be made of a material other than Al ₂ O ₃ . The conductor pattern 154 is made of Au. The conductor pattern 154 may be made of a material other than Au.

The conductor layer 152, the dielectric layer 153, and the conductor pattern 154 provided on the heat radiation plates 71A and 71B constitute metamaterials 71A1 and 71B1, respectively. The conductor layer 152, the dielectric layer 153 and the conductor pattern 154 provided on the heat radiation plates 71A and 71B are surface microstructures having a period approximately equal to the wavelength of the infrared rays IRA and IRB, respectively.

The heater 81 heats the thermal radiation plates 71A and 71B from the other main surface side of the substrate 151 . As a result, the infrared rays IRA and IRB are thermally radiated from the radiation surfaces 71AR and 71BR on which the conductor pattern 154 is arranged, respectively. The thermally radiated infrared rays IRA and IRB contain many specific wavelength components that resonate with the conductor pattern 154 . Therefore, the thermally radiated infrared rays IRA and IRB have peak wavelengths corresponding to the conductor pattern 154 . Therefore, the thermal radiation plates 71A and 71B function as selective radiation plates that selectively thermally radiate specific wavelength components. The specific wavelength component can be changed by changing the conductor pattern 154 .

FIG. 5 shows an example of a radiant energy spectrum of infrared rays thermally radiated by an infrared radiator provided in the blood glucose level measuring device of the first embodiment and an example of a radiant energy spectrum of infrared rays thermally radiated by a normal infrared heater. graph. In FIG. 5, the radiant energy is plotted on the vertical axis. Also, the horizontal axis is the wavelength.

As shown in FIG. 5, the peak width of the infrared radiant energy spectrum emitted by the infrared radiators 11 and 12 is significantly narrower than the peak width of the infrared radiant energy spectrum thermally radiated by an ordinary infrared heater. It's becoming

1.8 Effect The blood sugar level measuring device 1 can measure the blood sugar level non-invasively.

Also, the heat radiation plates 71A and 71B convert the heat supplied by the heater 81 into infrared rays IRA and IRB. Therefore, infrared radiators 11 and 12 do not require a cooling system. This is because if the temperature of infrared radiators 11 and 12 is too high, less heat can simply be supplied by heater 81 .

Infrared radiators 11 and 12 also have high energy efficiency.

Therefore, according to the blood glucose level measuring device 1, the infrared rays IR1 and IR2 thermally radiated by the infrared radiators 11 and 12 which do not require a cooling system and have high energy efficiency are used to determine the absorption amount of the infrared rays IR1 and IR2 by glucose. is identified. As a result, the size of the blood sugar level measuring device 1 that measures the blood sugar level in a non-invasive manner can be reduced. Also, the cost of the blood sugar level measuring device 1 can be reduced. In addition, the output of the light source provided in the blood sugar level measuring device 1 can be increased.

The infrared radiators 11 and 12 have the advantage that the radiant energy of the thermally radiated infrared rays IR1 and IR2 can be easily increased by increasing the areas of the radiation surfaces 11R and 12R.

Moreover, the infrared radiators 11 and 12 have the characteristic that they cannot start and stop the thermal radiation of the infrared rays IR1 and IR2 instantaneously. However, in the blood glucose level measuring device 1, since the optical paths of the infrared rays IR1 and IR2 are opened and closed by the shutters 31 and 32, the thermal radiation of the infrared rays IR1 and IR2 cannot be started and stopped instantaneously. The irradiation of the living body LB with the infrared rays IR1 and IR2 can be started and ended instantaneously. Using this feature, the infrared rays IR1 and IR2 irradiated to the living body LB may be pulsed infrared rays, and the intensity of the incoming infrared rays AIR may be detected in synchronization with the pulsed infrared rays.

2. Second Embodiment FIG. 6 is a cross-sectional view schematically illustrating a blood sugar level measuring device according to a second embodiment. FIG. 7 is a cross-sectional view schematically illustrating an infrared radiator provided in the blood sugar level measuring device of the second embodiment. FIG. 3 is also a graph showing an example of the absorbance spectrum of glucose and the radiation intensity spectrum of infrared rays thermally radiated by the infrared radiator provided in the blood sugar level measuring device of the second embodiment. FIG. 4 is also a perspective view schematically illustrating a heat radiation plate provided in the blood sugar level measuring device of the second embodiment.

In the following, differences of the blood sugar level measuring device 2 of the second embodiment shown in FIG. 6 from the blood sugar level measuring device 1 of the first embodiment shown in FIG. 1 are mainly described. As for the points that are not explained, the same configuration as that employed in the blood sugar level measuring device 1 is also employed in the blood sugar level measuring device 2 .

The blood sugar level measuring device 2 of the second embodiment illustrated in FIG. 6 is a wavelength independent type blood sugar level measuring device in which each of the infrared rays IR1 and IR2 irradiated to the living body LB has only one peak wavelength.

As illustrated in FIG. 7, each of the infrared radiators 11 and 12 includes a thermal radiation plate 70 and a heater 81. As shown in FIG.

The heater 81 heats the heat radiation plate 70 and supplies heat to the heat radiation plate 70 .

The thermal radiation plate 70 converts the supplied heat into infrared radiation IR illustrated in FIG. Also, the thermal radiation plate 70 thermally radiates infrared rays IR.

As illustrated in FIGS. 6 and 7, the heat radiation plate 70 has a radiation surface 70R. Therefore, each of the infrared radiators 11 and 12 has a radiation surface 70R. Also, each of the infrared radiators 11 and 12 thermally radiates infrared rays IR from the radiation surface 70R. A radiation surface 70R of the infrared radiator 11 constitutes a radiation surface 11R. A radiation surface 70R of the infrared radiator 12 constitutes a radiation surface 12R. The infrared radiation IR emitted by the infrared radiator 11 constitutes the infrared radiation IR1. The infrared radiation IR emitted by the infrared radiator 12 constitutes the infrared radiation IR2.

Also, as illustrated in FIGS. 6 and 7 , the heat radiation plate 70 comprises a metamaterial 701 . To this end, each infrared emitter 11 and 12 comprises a metamaterial 701 . Metamaterial 701 is disposed along emitting surface 70R. A metamaterial 701 provided in the infrared radiator 11 constitutes a metamaterial 111 . A metamaterial 701 provided in the infrared emitter 12 constitutes a metamaterial 121 .

In the second embodiment, the metamaterial 701 is a periodic structure comprising a plurality of pattern pieces periodically arranged in a direction parallel to the emitting surface 70 . Also, the peak wavelength of the infrared rays IR is a wavelength according to the pattern of the periodic structure 701 .

In the second embodiment, the thermal radiation plate 70 provided in each of the infrared radiators 11 and 12 is one thermal radiation plate. Also, the infrared rays IR thermally radiated by each of the infrared radiators 11 and 12 are one infrared ray. Also, the radiation surface 70R of each of the infrared radiators 11 and 12 is a single radiation surface. Also, the metamaterial 701 provided in each of the infrared radiators 11 and 12 is one metamaterial. However, the number of heat radiation plates provided in each of the infrared radiators 11 and 12, the number of infrared rays thermally radiated by each of the infrared radiators 11 and 12, the number of radiation surfaces of each of the infrared radiators 11 and 12, and the number of metamaterials provided in each of the infrared radiators 11 and 12 may be increased.

As illustrated in FIG. 6, optical systems 21 and 22 comprise waveguides 201 and 202, respectively.

As illustrated in FIG. 6, waveguides 201 and 202 have reflective surfaces 201R and 202R, respectively. Waveguides 201 and 202 also have exit ports 201E and 202E, respectively. Waveguides 201 and 202 also have internal spaces 201S and 202S, respectively.

Reflective surfaces 201R and 202R are inner surfaces of waveguides 201 and 202, respectively. The tube inner spaces 201S and 202S are surrounded by reflective surfaces 201R and 202R, respectively. The tube inner spaces 201S and 202S lead to exit ports 201E and 202E, respectively. The tube inner spaces 201S and 202S have diameters that decrease toward the exit ports 201E and 202E, respectively. Infrared radiators 11 and 12 are arranged in pipe inner spaces 201S and 202S, respectively. The radiation surfaces 11R and 12R face toward the exit ports 201E and 202E.

The reflecting surfaces 201R and 202R reflect the thermally radiated infrared rays IR1 and IR2, respectively.

The exit port 201E emits the thermally radiated infrared rays IR1 and the thermally radiated and reflected infrared rays IR1. The exit port 202E emits thermally radiated infrared rays IR2 and thermally radiated and reflected infrared rays IR2. Since the tube inner spaces 201S and 202S have diameters that decrease as they approach the exit ports 201E and 202E, the emitted infrared rays IR1 and IR2 are condensed.

According to the blood sugar level measuring device 2, similarly to the blood sugar level measuring device 1, the size of the blood sugar level measuring device 2 that measures the blood sugar level in a non-invasive manner can be reduced. Also, the cost of the blood sugar level measuring device 2 can be reduced. Moreover, the output of the light source provided in the blood sugar level measuring device 2 can be increased.

3 Third Embodiment FIG. 8 is a cross-sectional view schematically illustrating a blood sugar level measuring device according to a third embodiment. FIG. 9 is a cross-sectional view schematically illustrating an infrared radiator provided in the blood sugar level measuring device of the third embodiment. FIG. 10 is a graph showing an example of an absorbance spectrum of glucose and an infrared radiant intensity spectrum thermally radiated by an infrared radiator provided in the blood sugar level measuring device of the third embodiment. In FIG. 10, the vertical axis is the absorbance and the radiant intensity. Also, the horizontal axis represents the wave number. FIG. 4 is also a perspective view schematically illustrating a heat radiation plate provided in the blood sugar level measuring device of the third embodiment.

Differences of the blood sugar level measuring device 3 of the third embodiment shown in FIG. 8 from the blood sugar level measuring device 1 of the first embodiment shown in FIG. 1 will be mainly described below. As for the points that are not explained, the configuration similar to that employed in the blood sugar level measuring device 1 is also employed in the blood sugar level measuring device 3 .

The blood sugar level measuring device 3 of the third embodiment illustrated in FIG. 8 is a mixed wavelength type blood sugar level measuring device in which each of the infrared rays IR1 and IR2 irradiated to the living body LB has two or more peak wavelengths different from each other. .

The infrared IR1 illustrated in FIG. 8 has peak wavelengths λ1 and λ2. The infrared IR2 illustrated in FIG. 8 has peak wavelengths λ3 and λ4. The peak wavelengths λ3 and λ4 are different from the peak wavelengths λ1 and λ2. Therefore, the infrared rays IR1 and IR2 have different peak wavelengths.

Metamaterials 111 and 121 have different structures. The peak wavelengths λ1 and λ2 are wavelengths according to the structure of the metamaterial 111 . The peak wavelengths λ3 and λ4 are wavelengths according to the structure of the metamaterial 121 . Therefore, the peak wavelengths λ3 and λ4 are different from the peak wavelengths λ1 and λ2.

In the third embodiment, metamaterials 111 and 121 are periodic structures comprising a plurality of pattern pieces periodically arranged in a direction parallel to radiation surfaces 11R and 12R, respectively. Also, the peak wavelengths λ1 and λ2 are wavelengths according to the pattern of the periodic structure 111 . Also, the peak wavelengths λ3 and λ4 are wavelengths according to the pattern of the periodic structure 121 .

Each of infrared radiators 11 and 12 thermally radiates infrared rays IRA and IRB.

The metamaterials 71A1 and 71B1 have structures different from each other. The peak wavelengths of the infrared rays IRA and IRB are wavelengths corresponding to the structures of the metamaterials 71A1 and 71B1, respectively. Therefore, the peak wavelengths of the infrared rays IRA and IRB are different wavelengths.

In the third embodiment, metamaterials 71A1 and 71B1 are periodic structures having a plurality of pattern pieces periodically arranged in a direction parallel to radiation surfaces 71AR and 71BR, respectively. Also, the peak wavelengths of the infrared rays IRA and IRB are wavelengths corresponding to the patterns of the periodic structures 71A1 and 71B1, respectively.

According to the blood sugar level measuring device 3, similarly to the blood sugar level measuring device 1, the size of the blood sugar level measuring device 3 that measures the blood sugar level in a non-invasive manner can be reduced. Also, the cost of the blood sugar level measuring device 3 can be reduced. Moreover, the output of the light source provided in the blood sugar level measuring device 3 can be increased.

4. Fourth Embodiment FIG. 11 is a cross-sectional view schematically illustrating a blood sugar level measuring device according to a fourth embodiment. FIG. 12 is a cross-sectional view schematically illustrating an infrared radiator provided in the blood glucose level measuring device of the fourth embodiment. FIG. 13 is a plan view schematically illustrating an infrared radiator provided in the blood glucose level measuring device of the fourth embodiment. FIG. 10 is also a graph showing an example of the absorbance spectrum of glucose and the radiant intensity spectrum of infrared rays thermally radiated by the infrared radiator provided in the blood glucose level measuring device of the fourth embodiment. FIG. 4 is also a perspective view schematically illustrating a heat radiation plate provided in the blood sugar level measuring device of the fourth embodiment.

Differences between the blood sugar level measuring device 4 of the fourth embodiment shown in FIG. 11 and the blood sugar level measuring device 2 of the second embodiment shown in FIG. 6 will be mainly described below. Regarding the points that are not explained, the same configuration as that employed in the blood sugar level measuring device 2 is also employed in the blood sugar level measuring device 4 .

The blood sugar level measuring device 4 of the fourth embodiment illustrated in FIG. 11 is a mixed wavelength type blood sugar level measuring device in which each of the infrared rays IR1 and IR2 irradiated to the living body LB has two or more peak wavelengths different from each other. .

The infrared IR1 illustrated in FIG. 11 has peak wavelengths λ1 and λ2. The infrared IR2 illustrated in FIG. 11 has peak wavelengths λ3 and λ4. The peak wavelengths λ3 and λ4 are different from the peak wavelengths λ1 and λ2. Therefore, the infrared rays IR1 and IR2 have different peak wavelengths.

Metamaterials 111 and 121 have different structures. The peak wavelengths λ1 and λ2 are wavelengths according to the structure of the metamaterial 111 . The peak wavelengths λ3 and λ4 are wavelengths according to the structure of the metamaterial 121 . Therefore, the peak wavelengths λ3 and λ4 are different from the peak wavelengths λ1 and λ2.

In the fourth embodiment, metamaterials 111 and 121 are periodic structures comprising a plurality of pattern pieces periodically arranged in a direction parallel to radiation surfaces 11R and 12R, respectively. Also, the peak wavelengths λ1 and λ2 are wavelengths corresponding to the patterns of the periodic structures 111 and 121, respectively.

As illustrated in FIGS. 12 and 13, the heat radiation plate 70 has radiation surfaces 71AR and 71BR. Thus, infrared radiators 11 and 12 each have radiation surfaces 71AR and 71BR. Also, each of the infrared radiators 11 and 12 thermally radiates infrared rays IRA and IRB illustrated in FIG. 11 from radiation surfaces 71AR and 71BR, respectively. Radiation surfaces 71AR and 71BR of infrared radiator 11 constitute radiation surface 11R. Radiation surfaces 71AR and 71BR of infrared radiator 12 constitute radiation surface 12R. The infrared rays IRA and IRB thermally radiated by the infrared radiator 11 constitute the infrared rays IR1. The infrared rays IRA and IRB thermally emitted by the infrared radiator 12 constitute the infrared rays IR2.

Also, as illustrated in FIGS. 12 and 13, the heat radiation plate 70 includes metamaterials 71A1 and 71B1, respectively. To this end, each of infrared radiators 11 and 12 comprises metamaterials 71A1 and 71B1. Metamaterials 71A1 and 71B1 are disposed along emitting surfaces 71AR and 71BR, respectively. The metamaterials 71A1 and 71B1 provided in the infrared radiator 11 constitute the metamaterial 111 . The metamaterials 71A1 and 71B1 provided in the infrared radiator 12 constitute the metamaterial 121. FIG.

The metamaterials 71A1 and 71B1 have structures different from each other. The peak wavelengths of the infrared rays IRA and IRB are wavelengths corresponding to the structures of the metamaterials 71A1 and 71B1, respectively. Therefore, the peak wavelengths of the infrared rays IRA and IRB are different wavelengths.

In the fourth embodiment, metamaterials 71A1 and 71B1 are periodic structures having a plurality of pattern pieces periodically arranged in a direction parallel to radiation surfaces 71AR and 71BR, respectively. Also, the peak wavelengths of the infrared rays IRA and IRB are wavelengths corresponding to the patterns of the periodic structures 71A1 and 71B1, respectively.

According to the blood sugar level measuring device 4, similarly to the blood sugar level measuring device 1, the size of the blood sugar level measuring device 4 that measures the blood sugar level in a non-invasive manner can be reduced. Also, the cost of the blood sugar level measuring device 4 can be reduced. Moreover, the output of the light source provided in the blood sugar level measuring device 4 can be increased.

5 Fifth Embodiment FIG. 14 is a cross-sectional view schematically illustrating a blood sugar level measuring device according to a fifth embodiment. FIG. 15 is a cross-sectional view schematically illustrating an infrared radiator provided in the blood glucose level measuring device of the fifth embodiment. FIG. 16 is also a plan view schematically illustrating an infrared radiator provided in the blood glucose level measuring device of the fifth embodiment. FIG. 3 is also a graph showing an example of the absorbance spectrum of glucose and the radiation intensity spectrum of infrared rays thermally radiated by the infrared radiator provided in the blood glucose level measuring device of the fifth embodiment. FIG. 4 is also a perspective view schematically illustrating a heat radiation plate provided in the blood sugar level measuring device of the fifth embodiment.

In the following, differences of the blood sugar level measuring device 5 of the fifth embodiment shown in FIG. 14 from the blood sugar level measuring device 1 of the first embodiment shown in FIG. 1 are mainly described. As for the points that are not explained, the same configuration as that employed in the blood sugar level measuring device 1 is also employed in the blood sugar level measuring device 5 .

The blood sugar level measuring device 5 of the fifth embodiment illustrated in FIG. 14 is a wavelength independent type blood sugar level measuring device in which each of the infrared rays IR1 and IR2 irradiated to the living body LB has only one peak wavelength.

As illustrated in FIG. 14, the blood sugar level measuring device 5 of the fifth embodiment comprises an infrared emitter 10, shutters 31, shutters 32, detectors 41, controllers 51 and calculators 61. As shown in FIG.

The detector 41 detects an amount D that reflects the amount of absorption of the infrared rays IR1 and IR2 by glucose in the living body LB. In the fifth embodiment, detector 41 is an acoustic wave detector. Also, the detected quantity D is the intensity of the acoustic wave AW arriving from the living body LB while the infrared rays IR1 and IR2 are being irradiated to the living body LB. Acoustic wave detectors are microphones. The acoustic wave detector may be an acoustic wave detector other than a microphone. Acoustic waves AW are acoustic waves generated by the photoacoustic effect when glucose absorbs infrared rays IR1 and IR2.

As illustrated in FIGS. 14, 15 and 16, infrared radiator 10 has a plurality of radiation surfaces 11R and 12R. The infrared radiator 10 thermally radiates infrared rays IR1 and IR2 from radiation surfaces 11R and 12R, respectively. The radiation surfaces 11R and 12R face the same direction.

As illustrated in FIGS. 14, 15 and 16, infrared emitter 10 comprises metamaterials 111 and 121 . Metamaterials 111 and 121 are disposed along emitting surfaces 11R and 12R, respectively.

Metamaterials 111 and 121 have different structures. The peak wavelengths λ1 and λ2 are wavelengths according to the structures of the metamaterials 111 and 121, respectively. Therefore, the peak wavelengths λ1 and λ2 are different from each other. Therefore, the infrared rays IR1 and IR2 have different peak wavelengths.

In the fifth embodiment, metamaterials 111 and 121 are periodic structures comprising a plurality of pattern pieces periodically arranged in a direction parallel to radiation surfaces 11R and 12R, respectively. Also, the peak wavelengths λ1 and λ2 are wavelengths corresponding to the patterns of the periodic structures 111 and 121, respectively.

As illustrated in FIG. 15, the infrared radiator 10 includes a heat radiation plate 70 and a heater 81. As shown in FIG.

As illustrated in FIG. 16, the heat radiation plate 70 has radiation surfaces 11R and 12R.

According to the blood sugar level measuring device 5, similarly to the blood sugar level measuring device 1, the size of the blood sugar level measuring device 5 that measures the blood sugar level in a non-invasive manner can be reduced. Also, the cost of the blood sugar level measuring device 5 can be reduced. Moreover, the output of the light source provided in the blood sugar level measuring device 5 can be increased.

Further, according to the blood sugar level measuring device 5, the intensity of the acoustic wave AW arriving from a wide range can be easily detected. Therefore, there is no need to collect the infrared rays IR1 and IR2, and an optical system for collecting the infrared rays IR1 and IR2 can be omitted.

6. Sixth Embodiment FIG. 17 is a cross-sectional view schematically illustrating a blood sugar level measuring device according to a sixth embodiment. In the following, mainly the differences between the optical system 21 provided in the blood sugar level measuring device 6 of the sixth embodiment shown in FIG. explain.

As shown in FIG. 17, the blood sugar level measuring device 6 of the sixth embodiment includes an infrared radiator 11 having a metamaterial 111 along a radiation surface 11R, an optical system 21, a shutter 31, a detector 41, It comprises at least a controller 51 , a calculator 61 , an incoming infrared condensing lens 241 and a cold air source 311 .

However, although FIG. 17 shows the configuration in which the blood glucose level measuring device 6 includes only one set of the infrared radiator 11, the optical system 21, and the shutter 31, this is for the sake of simplicity of explanation and illustration. The actual blood sugar level measuring device 6 has a configuration capable of selectively emitting two kinds of infrared rays having different peak wavelengths. In such a case, the blood glucose level measuring device 6 may be of a wavelength independent type or a wavelength mixed type.

For example, the blood sugar level measuring device 6 includes a set of a plurality of infrared radiators and an optical system like the blood sugar level measuring device 1 of the first embodiment, specifically, the infrared radiator shown in FIG. 11 and the optical system 21, but with a different metamaterial configuration, the wavelength of emitted infrared rays is different from that of the infrared radiator 11. can be configured. In such a case, like the configuration shown in FIG. 1 and the like, a shutter corresponding to each optical system is also provided.

Alternatively, the blood sugar level measuring device 6 has a single infrared radiator 11 and an optical system 21 as shown in FIG. Alternatively, the infrared radiator 11 may have a plurality of radiating surfaces facing the same direction, and different infrared radiation may be thermally radiated from each radiating surface. In such a case, two shutters are provided for each radiation surface, similar to the configuration shown in FIG.

The infrared radiator 11 is arranged such that the radiation surface 11R having the metamaterial 111 is perpendicular to the direction from the infrared radiator 11 toward the living body LB (hereinafter referred to as irradiation direction).

The optical system 21 has a lens array 91 and a lens 141 . The lens array 91 and the lens 141 are arranged parallel to the radiation surface 11R of the infrared radiator 11 .

The lens array 91 has a flat entrance surface side and a large number of convex portions each functioning as a convex lens on the exit surface side. The lens array 91 refracts the infrared rays IRα emitted in various directions from the infrared radiator 11, which is a diffuse radiation source, into infrared rays IRβ parallel to the irradiation direction. Lens 141 collects infrared rays IRβ. The infrared rays IRγ condensed by the lens 141 are irradiated to the living body.

The blood glucose level measuring device 6 further comprises a cool air source 311 . A cool air source 311 is provided to send cool air CA to the lens 141 . By cooling the lens 141 with the cold air CA, the temperature rise of the lens 141 is suppressed when the infrared rays IRβ are collected. It should be noted that the cold air source 311 may be anything as long as it can cool the lens 141 and maintain its temperature at about room temperature. Therefore, the blood sugar level measuring apparatus 6 also does not require a cooling system for cooling the infrared radiator 11, like the blood sugar level measuring apparatuses of the other embodiments.

In the blood glucose level measuring device 6, by adopting the above-described configuration, the parabolic poles 101 (and 102) of the first and third embodiments and the waveguides 201 (and 202), the collection efficiency of the infrared rays irradiated to the living body LB is improved. FIG. 17 illustrates a configuration in which the infrared radiator 11 and the optical system 21 are accommodated in a simple housing 301 that does not function as a parabolic mirror or waveguide.

If the blood sugar level measuring device 6 is further provided with a different set of an infrared radiator and an optical system, the same configuration as that shown in FIG. 17 is adopted for that as well.

Also, the blood sugar level measuring devices 1 and 3 of the first and third embodiments having the lens 141 (and 142) like the blood sugar level measuring device 6 may be provided with the cool air source 311 .

Further, the blood sugar level measuring device 6 includes a detector 41, which is an infrared detector, as in the first to fourth embodiments. The detector 41 detects an amount D that reflects the amount of absorption of the infrared rays IR1 and IR2 by glucose in the living body LB.

However, the blood glucose level measuring device 6 is provided with an incoming infrared rays condensing lens 241 in front of the detector 41 (between the living body LB and the detector 41), and Infrared rays are detected by detector 41 . Thereby, the detection sensitivity is enhanced.

In FIG. 17, the infrared light reflected by the living body LB is detected, but this is merely an example, and the detector 41 is arranged at the same position as in the first to fourth embodiments. It may be a mode to be done.

Also in this embodiment, as in the first to fifth embodiments, it is possible to reduce the size of the blood sugar level measuring device that measures the blood sugar level in a non-invasive manner. Also, the cost of the blood sugar level measuring device can be reduced. Also, the output of the light source provided in the blood sugar level measuring device can be increased.

7 Use of Filter FIG. 18 is a schematic diagram showing how an infrared transmission filter (hereinafter simply referred to as a filter) FT is arranged in the middle of the infrared light path from the infrared radiator 11 to the living body LB. FIG. 19 is a diagram showing changes in the infrared radiation spectrum (wavelength dependence of radiant energy) due to the placement of the filter FT in the case shown in FIG. For example, in the case of the blood sugar level measuring device 6 of the sixth embodiment, it can be provided anywhere between the lens array 91 and the shutter 31 .

In general, when irradiating a substance with infrared rays and measuring the amount according to the degree of absorption of infrared rays in the substance, the wavelength of the irradiated infrared rays (peak wavelength) corresponds to the absorption wavelength of the substance, and the profile of the infrared rays The smaller the peak half width at , the better the measurement sensitivity.

In view of this point, the filter FT may be arranged in any of the optical systems of the first to sixth embodiments. In such a case, as the filter FT, one that transmits only infrared rays in a very narrow wavelength range including a certain central wavelength λa corresponding to the absorption wavelength in the living body LB is used.

Now, as shown in FIG. 18, it is assumed that infrared rays IRx0 emitted from the infrared radiator 11 are incident on the filter FT, and the component that has passed through the filter FT is again emitted from the filter FT as infrared rays IRx1. Then, as shown in FIG. 19, in the radiation spectrum SPx0 of the infrared rays IRx0 before incidence on the filter, the maximum intensity is Ix0 at the center wavelength λa, and the peak half width is Wx0. On the other hand, in the radiation spectrum SPx1 of the infrared ray IRx1, the maximum intensity is Ix1 (<Ix0) at the same center wavelength λa, and the peak half width is Wx1 (<Wx0).

In this case, the half-value width of the infrared light irradiated to the living body LB becomes smaller than when the filter FT is not provided, so that the measurement can be performed with higher sensitivity.

For example, if the infrared radiator 11 (and 12) has a central wavelength λa in the range of 8 μm to 10 μm and can emit infrared rays with a half width of about 1 μm, the transmittance is 70% and the filter FT It is preferable to use a filter FT which has a half-value width of about 500 nm for the infrared rays transmitted through. In this case, it is possible to irradiate the living body LB with infrared light with a reduced half-value width while ensuring a relatively high intensity.

It should be noted that a temperature rise may occur in the filter FT due to energy absorption. Therefore, filter FT is preferably used with cooling. This is because if the energy absorbed in the filter FT changes into heat, thermal radiation will occur from the filter FT itself, and infrared rays of other wavelengths will be generated, which is not preferable.

However, since the wavelength range of the radiation spectrum SPx0 of the infrared rays IRx0 emitted from the infrared radiator 11 is relatively limited in advance, it can be said that the energy absorption in the filter FT is relatively small. Therefore, even if it is necessary to cool the filter FT in order to suppress the temperature rise, the mechanism can be simplified. For example, if the blood sugar level measuring device has a cold air source like the blood sugar level measuring device 6 of the sixth embodiment, it is possible to cool the filter FT with cold air from the cold air source. The arrangement position of the filter FT in the optical system 21 may be any suitable position in each embodiment.

On the other hand, FIG. 20 is a schematic diagram showing, for comparison, how the same filter FT as in FIG. 18 is placed in the middle of the optical path of infrared rays emitted from a general infrared heater HT. FIG. 21 is a diagram showing changes in the radiation spectrum due to the arrangement of the filters FT in the case shown in FIG.

FIG. 20 shows a case where infrared rays IRy0 emitted from a general infrared heater HT are incident on a filter FT, and the component that has passed through the filter FT is again emitted from the filter FT as infrared rays IRy1. Infrared radiation from a general infrared heater HT resembles blackbody radiation. Therefore, as shown in FIG. 21, the radiation spectrum SPy0 of the infrared rays IRy0 before entering the filter is similar to the spectrum of black body radiation, and the wavelength giving the maximum intensity Iy0 is different from the wavelength λa. . On the other hand, in the radiation spectrum SPy1 of the infrared ray IRy1, the maximum intensity Iy1 (<Iy0) is assumed at the center wavelength λa. It is assumed that the radiation spectrum SPy1 is substantially the same as the radiation spectrum SPx1 in FIG.

Comparing FIG. 19 and FIG. 21, the latter, in which the infrared rays IRy0 emitted from the general infrared heater HT are incident on the filter, absorbs more energy in the filter FT. Therefore, in this case, since it is essential to sufficiently cool the filter FT, it is difficult to simplify the cooling mechanism.

As described above, in the blood glucose level measuring devices 1 to 6 according to the first to sixth embodiments, which employ the infrared radiator 11 (and 12) as the infrared radiation source, the infrared radiator 11 (and 12) emits a living body. It is possible to employ a configuration in which an infrared transmission filter FT is added in the middle of the infrared light path toward the LB. The addition of such a filter FT is expected to improve the detection sensitivity. On the other hand, a simple cooling mechanism is sufficient for the filter FT that absorbs infrared rays.

8 Another Example of Thermal Radiation Plate FIGS. 22 to 24 are perspective views schematically illustrating another example of the thermal radiation plate provided in the blood glucose level measuring devices according to the first to sixth embodiments.

Each of the heat radiation plates 71A, 71B and 70 may be a heat radiation plate other than the heat radiation plate illustrated in FIG. For example, each of the heat radiation plates 71A, 71B and 70 may be the heat radiation plate illustrated in FIG. 22, FIG. 23 or FIG.

Each of the heat radiation plates 71A, 71B and 70 shown in FIG. A plurality of microcavities 802 are formed in the conductor layer 801 . A plurality of microcavities 802 are arranged in a matrix. Conductive layers 801 provided on the heat radiation plates 71A, 71B and 70 constitute metamaterials 71A1, 71B1 and 701 respectively.

Each of the heat radiation plates 71A, 71B and 70 illustrated in FIG. A dielectric layer 812 is disposed over the conductor layer 811 . A conductor pattern 813 is disposed over the dielectric layer 812 . Conductive pattern 813 includes a plurality of split rings 814 . A plurality of split rings 814 are arranged in a matrix. A conductor layer 811, a dielectric layer 812 and a conductor pattern 813 provided on the heat radiation plates 71A, 71B and 70 constitute metamaterials 71A1, 71B1 and 701, respectively.

Each _of the heat radiation plates 71A, _71B and 70 illustrated in FIG _. . W layer 821, _SiO2 layer 822, Ge layer 823, _SiO2 layer 824, Ge layer 825, _SiO2 layer 826 and Ge layer 827 are stacked from bottom to top in the order listed. The W layer 821, _SiO2 layer 822, Ge layer 823, _SiO2 layer 824, Ge layer 825, _SiO2 layer 826 and Ge layer 827 provided on the heat radiation plates 71A, 71B and 70 are metamaterials 71A1, 71B1 and 701 respectively.

Although the present invention has been described in detail, the above description is, in all aspects, illustrative and not intended to limit the present invention. It is understood that numerous variations not illustrated can be envisioned without departing from the scope of the invention.

Reference Signs List 1, 2, 3, 4, 5, 6 blood glucose level measuring device 10, 11, 12 infrared radiator 21, 22 optical system 31, 32 shutter 41 detector 51 controller 61 calculator 70, 71A, 71B thermal radiation plate 81 Heater 91 Lens array 101, 102 Parabolic mirror 111, 121, 71A1, 71B1, 701 Metamaterial 141, 142 Lens 201, 202 Waveguide 311 Cold air source LB Living body IR1, IR2, IR, IRA, IRB Infrared AIR Incoming infrared ray AW Acoustic wave CA Cold air FT (Infrared transmission) filter

Claims (18)

an infrared radiator having a radiation surface, comprising a metamaterial, and thermally radiating infrared rays having a peak wavelength corresponding to the structure of the metamaterial from the radiation surface;
a detector that detects an amount that reflects the amount of infrared radiation absorbed by glucose in a living body;
A blood sugar level measuring device. 2. A blood sugar level measuring apparatus according to claim 1, wherein said amount is intensity of incoming infrared rays coming from said living body while said living body is being irradiated with said infrared rays. 2. The blood sugar level measuring apparatus according to claim 1, wherein said amount is intensity of acoustic waves coming from said living body while said living body is being irradiated with said infrared rays. 4. The blood sugar level measuring device according to any one of claims 1 to 3, comprising an optical system for condensing said infrared rays. The optical system is
a parabolic mirror having a focal point and a reflective surface that reflects the infrared radiation;
a lens that collects the reflected infrared light;
with
5. The blood glucose measuring device of claim 4, wherein said infrared emitter is located at said focal point. The parabolic mirror has an axis of rotational symmetry,
the radiating surfaces are two or more radiating surfaces,
the infrared rays are two or more infrared rays,
the two or more radial surfaces are oriented perpendicular to the direction in which the axis of rotational symmetry extends and oriented in different directions;
6. The blood sugar level measuring apparatus according to claim 5, wherein said infrared radiator thermally radiates said two or more infrared rays from said two or more radiation surfaces, respectively. The metamaterial is two or more metamaterials,
the two or more metamaterials are arranged along the two or more emitting surfaces, respectively, and have the same structure;
7. The blood sugar level measuring device according to claim 6, wherein the peak wavelengths of the two or more infrared rays are wavelengths corresponding to the structures of the two or more metamaterials and are the same wavelength. The metamaterial is two or more metamaterials,
the two or more metamaterials are arranged along the two or more emitting surfaces and have different structures;
7. The blood sugar level measuring device according to claim 6, wherein the two or more infrared peak wavelengths are wavelengths corresponding to structures of the two or more metamaterials, respectively, and are different wavelengths. The optical system is
A reflective surface that is an inner surface and reflects the infrared rays, an exit port that emits the infrared rays and the reflected infrared rays, and an inner pipe space surrounded by the reflective surfaces and having a diameter that decreases toward the exit opening and toward the exit opening. and a waveguide having
5. The blood sugar level measuring device according to claim 4, wherein the infrared radiator is arranged in the intra-pipe space. 10. The blood sugar level measuring device according to claim 9, wherein said radiation surface faces toward said exit port. the radiating surfaces are two or more radiating surfaces,
The metamaterial is two or more metamaterials,
the two or more metamaterials are arranged along the two or more emitting surfaces and have different structures;
the infrared rays are two or more infrared rays,
the two or more infrared peak wavelengths are wavelengths corresponding to the structures of the two or more metamaterials, and are different wavelengths;
11. The blood sugar level measuring device according to claim 10, wherein said infrared radiator thermally radiates said two or more infrared rays from said two or more radiation surfaces, respectively. comprising a plurality of infrared radiators including the infrared radiator;
The plurality of infrared radiators are
each having a plurality of radiating surfaces,
each comprising a plurality of metamaterials arranged along the plurality of radiation surfaces and having structures different from each other;
12. The blood sugar level measuring device according to any one of claims 1 to 11, wherein a plurality of infrared rays having wavelengths corresponding to the plurality of metamaterials and having mutually different peak wavelengths are thermally radiated from the plurality of radiation surfaces. 13. The blood sugar level measuring device according to claim 12, wherein the plurality of infrared peak wavelengths include a wavelength at which glucose absorbance is minimum and a wavelength at which glucose absorbance is maximum. The infrared radiator is
a heat radiation plate having the radiation surface and comprising the metamaterial;
a heater for heating the heat radiation plate;
The blood glucose level measuring device according to any one of claims 1 to 13, comprising: the radiating surfaces are two radiating surfaces,
The metamaterials are two metamaterials,
The infrared radiator is
two heat radiation plates each having the two radiation surfaces and each comprising the two metamaterials;
a heater sandwiched between the two heat radiation plates;
15. The blood glucose level measuring device according to any one of claims 1 to 14, comprising: 16. The blood sugar level measuring device according to any one of claims 1 to 15, further comprising a shutter for opening and closing the optical path of said infrared rays. 17. The blood sugar level measuring device according to any one of claims 1 to 16, comprising a calculator for calculating a blood sugar level from said amount. 18. The blood sugar level measuring device according to any one of claims 1 to 17, comprising a lens array that refracts the infrared rays into infrared rays parallel to the irradiation direction.

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