JP2005224525A - Glucose concentration measuring apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the precision of measurement of the noninvasive measurement of the glucose concentration by controlling the characteristic variation by temperature changes and improving a S/N ratio. <P>SOLUTION: A glucose concentration measuring apparatus 1 includes the light source 2 which consists of a lamp, a spectroscope 3 to disperse the light emitted from the light source 2 and detectors 4 and 6 to detect the light which diffuses in or penetrates through a living body A after it is dispersed by the spectroscope 3, and measures the glucose concentration in the living body A on the basis of the absorbance in each wavelength, wherein a light source section 9 to accommodate the light source 2 and an optical section 10 to accommodate the spectroscope 3 and the detectors 4 and 6 are mutually separated by a partition wall 11, and an optically transparent window member 13 is disposed on the partition wall 11 to allow the light from the light source 2 of the light source section 9 to penetrate and enter into the spectroscope 3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a glucose concentration measuring apparatus.

Conventionally, blood glucose concentration measurement has been performed for the determination of diabetes, and in particular, glucose concentration measurement has been performed in order to examine blood glucose levels that determine the insulin dose of diabetic patients. The measurement of glucose concentration is generally performed by directly analyzing blood collected from a finger or an arm. Since the glucose concentration in the blood in the patient's body changes depending on the measurement conditions such as before and after meals and after exercise, frequent glucose concentration measurement is necessary to obtain an accurate blood glucose level.
However, the above-described method for directly analyzing the collected blood has a problem in that blood must be collected by inserting an injection needle or the like every time the glucose concentration is measured, and the burden on the patient is large.

In order to solve this problem, non-invasive detection of light emitted outside the living body by irradiating a living tissue such as a finger, arm, earlobe, etc. A glucose concentration measurement method has been proposed (see, for example, Patent Document 1). The method of Patent Document 1 prepares an optical fiber bundle configured by bundling a plurality of light-emitting fibers and a plurality of light-receiving fibers, and contacts the tip surface of each optical fiber constituting the optical fiber bundle with the living body surface. Place in state. Then, by irradiating near-infrared light collected from a halogen lamp onto a plurality of light-emitting fibers from the tip surfaces of the light-emitting fibers, the light enters the living body, diffuses in the living body, and returns from the living body surface to the outside of the living body Is received by a plurality of light receiving fibers, and the glucose concentration is calculated by analyzing the spectrum of the received light.
JP 2000-131322 A (FIG. 3 etc.)

In the case of a method for measuring glucose concentration non-invasively with light, such as the method disclosed in Patent Document 1, since the optical signal obtained from the living body is very small, how to improve the measurement accuracy. Is the problem.
The method disclosed in Patent Document 1 uses a large number of light-emitting fibers and light-receiving fibers to increase the amount of light detected and the amount of light detected, thereby increasing the amount of information on the detected glucose concentration. However, when the light from the halogen lamp is condensed on the optical fiber bundle, the ratio of the cross-sectional area of the core of the light-emitting fiber constituting the fiber bundle to the cross-sectional area of the entire fiber bundle is very small. There is a disadvantage that most of the light emitted from the lamp is discarded without entering the light emitting fiber. In addition, the optical fiber has a property that it cannot transmit light incident at an angle larger than a specific incident angle, and this also has a disadvantage in that the amount of light used for measurement is limited. .

  In order to avoid this inconvenience, it is necessary to increase the light emission amount of the lamp. In this case, there is a problem that the apparatus becomes large or the heat generation amount increases. When the calorific value increases, there is a possibility that the temperature of each part of the apparatus is raised to cause a drift in the detection signal, which may be disadvantageous in that the measurement accuracy is lowered. For this reason, a cooling device such as an air cooling device is required, but the change in the airflow around the device also causes the measurement accuracy to fluctuate.

  The present invention has been made in view of the above-described circumstances, and has improved the S / N ratio by increasing the amount of light while solving the problem of detection signal drift due to heat generation and the problem of airflow change around the apparatus. An object of the present invention is to provide a glucose concentration measuring device capable of improving measurement accuracy.

In order to achieve the above object, the present invention provides the following means.
The present invention comprises a light source composed of a lamp, a spectroscope that splits light emitted from the light source, and a detector that detects light diffused or transmitted in a living body after being split by the spectroscope, A glucose concentration measuring device for measuring glucose concentration in a living body based on absorbance at each wavelength, wherein a light source unit for storing a light source and an optical unit for storing a spectroscope and a detector are mutually partitioned by a partition wall. In addition, the glucose concentration measuring device is provided in which the partition wall is provided with an optically transparent window member that transmits light from the light source of the light source unit and enters the spectroscope.

  According to this invention, the light emitted from the light source is incident on the window member provided in the partition wall. Since the window member is made of an optically transparent material, light passes through the window member and enters the spectroscope. The light split by the spectroscope is incident on the living body, then diffuses or permeates in the living body, is emitted outside the living body, and is detected by the detector. The light diffused or passed through in the living body is absorbed by light of a specific wavelength depending on the glucose concentration in the living body, and the light detected by the detector is analyzed to obtain the absorbance in the living body. The concentration will be measured.

  In this case, according to the present invention, since the light source unit that houses the light source and the optical unit that houses the spectroscope and the detector are mutually partitioned by the partition wall, the heat generated in the light source unit is generated in the optical unit. It is blocked by a partition wall so that it is not transmitted and air heated by the heat is not circulated around the spectrometer and detector. Therefore, even if the light quantity of the light source is increased, it is possible to suppress the influence of the heat generated thereby on the detection unit and the spectroscope. Even if an air-cooling device is provided to cool the heat generated by the light source, the airflow generated thereby is prevented from flowing through the spectrometer, detector, or air path, and fluctuations in measurement conditions are prevented. Can be prevented.

  In the said invention, it is preferable that a light source consists of an arc lamp. Since the arc lamp emits a large amount of light, it is possible to increase the amount of light detected by the detection signal and improve the measurement accuracy.

  In the said invention, it is preferable that the light source part is equipped with the air-cooling apparatus which cools the said light source. According to the present invention, since the light source can be cooled by the operation of the air cooling device, it is possible to use a light source with a large amount of light. In addition, since the air flow generated by the air cooling device is blocked by the partition wall and the window member so as not to enter the optical unit, the measurement accuracy is not adversely affected even if the air cooling device is used.

In the said invention, it is preferable that the said window member has obstruct | occluded the through-hole in the sealing state with the elastic adhesive agent apply | coated over the perimeter of the through-hole provided in the said partition.
According to this invention, when the light emitted from the light source is allowed to pass through, the window member receives a large amount of radiant heat on the surface facing the light source, and is thus thermally expanded. According to the present invention, the window member is not rigidly fixed to the through hole provided in the partition wall, but is attached by an elastic adhesive material, so that the elastic adhesive can be expanded and contracted even when thermally expanded. It can be deformed relatively freely. Therefore, it is possible to prevent excessive stress from acting on the window member, and to prevent the window member from being damaged. In addition, since the elastic adhesive is applied over the entire circumference of the through hole to close the through hole in a sealed state, the light source unit and the optical unit can be partitioned in a sealed state and generated in the light source unit Airflow and heat can be prevented from leaking to the light source section.

In the said invention, it is preferable that the said window member consists of a several window member piece arrange | positioned in the state which faced | matched the end surface.
According to this invention, a light source part and an optical part are interrupted | blocked in a sealing state by the window member comprised by arrange | positioning a plurality of window member pieces in the state which abutted each end surface. Even if the surface temperature of the window member is raised by the radiant heat from the light source, the thermal expansion of the window member generated thereby is distributed to the thermal expansion of each window member piece, so that the stress applied to each window member piece is further increased. It will be reduced and it will be prevented from breaking.

In the said invention, it is preferable that the end surface where the said window member pieces are faced | matched inclines in the thickness direction of a window member piece.
According to this invention, since the butting surfaces of the window member pieces are inclined in the thickness direction, even if the window member pieces are relatively inclined, the gap between the two is maintained so as not to be opened. As a result, the light source unit and the optical unit are maintained in a blocked state.

In the said invention, it is preferable that the said window member has a wavelength characteristic which permeate | transmits only the light of a specific wavelength range.
According to this invention, when the light emitted from the light source is allowed to pass through the window member, only the light in a specific wavelength region is allowed to pass, and the passage of other light is prohibited. Thereby, it is possible to prevent light unnecessary for measurement from entering the optical unit from the light source unit. For example, when a region having a wavelength of 1200 nm or less is unnecessary for measurement, the window member may have a wavelength characteristic that transmits only light having a wavelength of 1200 nm or more.

  The present invention includes a light source, a spectroscope that separates light emitted from the light source before or after being incident on a living body, and a detector that detects light diffused or transmitted in the living body, and the absorbance at each wavelength. A glucose concentration measuring device for measuring the glucose concentration in a living body based on the above, and a control device for performing a measurement operation at a predetermined time interval shorter than the measurement interval separately from the measurement performed at a time interval A glucose concentration measuring device is provided.

According to the present invention, the light emitted from the light source is incident on the spectroscope and separated and then enters the living body, or the light emitted from the light source is incident on the living body and then dispersed in the spectroscope. Thus, the glucose concentration in the living body is measured based on the absorbance at each wavelength. In this case, the measurement of the glucose concentration is performed a plurality of times at time intervals in order to ensure the accuracy of the measurement or to see the time change of the glucose concentration in the living body. When the measurement is performed at a certain time interval, the state of the device at each measurement is constant, so there is no variation in measurement, but when the time interval is large, the device is completely stopped. In order to start the measurement, a predetermined warm-up operation time is required, and the measurement result may vary depending on the way of the warm-up operation.
According to the present invention, the operation of the control device causes the measurement operation to be performed at a predetermined time interval shorter than the measurement interval separately from the measurement, so that it is possible to always set the same operation state at the time of measurement. Thus, variations in measurement results can be prevented.

  In addition, the present invention includes a light source, a spectroscope that separates light emitted from the light source before or after being incident on a living body, and a detector that detects light diffused or transmitted in the living body, and each wavelength. A glucose concentration measuring device for measuring glucose concentration in a living body based on the absorbance in the blood vessel, comprising a control device for continuously performing a measurement operation between measurements performed at time intervals Provide a measuring device.

  According to the present invention, since the measurement device is continuously operated by the operation of the control device, it is possible to always set the same operation state at the time of measurement, and the measurement result Can be prevented.

In the said invention, it is preferable to provide the restriction | limiting means which is actuated in the case of the measurement operation performed separately from a measurement, and prohibits that the light from a light source is radiate | emitted toward a biological body.
According to this invention, even if a measurement operation is performed at a time other than the time of measurement, the light from the light source is prohibited from being emitted toward the living body due to the operation of the limiting means. Can be prevented. Depending on the type of light, there is light that adversely affects the living body, but even in such a case, irradiation to the living body can be kept to the minimum necessary for measurement.

In the above invention, it is preferable that the limiting means comprises a shutter that blocks an outgoing optical path to a living body during a measurement operation performed separately from the measurement.
According to the present invention, the light emission path to the living body is blocked by the operation of the shutter, so that irradiation of light to the living body during non-measurement can be easily prohibited.

  In the above invention, the limiting means includes a mirror that is disposed in an optical path to the living body and reflects light in a predetermined direction during a measurement operation performed separately from the measurement, and the light reflected by the mirror. It is preferable to include a filter for attenuating, and bypass means for allowing light transmitted through the filter to enter the detector.

  According to the present invention, when the mirror is arranged in the emission optical path to the living body during non-measurement, the light traveling toward the living body is blocked by the mirror and reflected in a predetermined direction. The light reflected by the mirror is attenuated by passing through the filter and is incident on the detector by the bypass means. That is, light can be incident on the spectroscope, detector, etc. not only during measurement but also during non-measurement, and measurement variations due to an increase in measurement interval can be prevented.

In the said invention, it is preferable that the said filter has an attenuation factor equivalent to a biological body.
By setting the attenuation rate of the filter to be equal to the attenuation rate of the living body, it is possible to make light equivalent to that at the time of measurement incident on a spectroscope, a detector, etc. even during non-measurement. Thereby, the dispersion | variation of the measurement by opening a measurement space | interval can be prevented further by always setting a spectrometer, a detector, etc. in the state equivalent to a measurement state.

In the said invention, it is preferable that the said filter consists of a variable filter which can change an attenuation factor, and an attenuation factor is changed according to the attenuation factor of a biological body.
According to the present invention, by setting the attenuation rate according to the individual difference of the patient to be measured, it is possible to more strictly prevent the detection signal from being varied by the measurement object and improve the measurement accuracy.

In the said invention, it is preferable that the light-shielding means which can interrupt | block incidence of the light to this detector just before the said detector is provided.
According to this invention, the light incident on the detector is blocked immediately before the detector by the operation of the light blocking means. Therefore, stray light in the glucose concentration measuring device can be prevented from entering the detector, and a state where no light enters the detector can be realized. By obtaining the output value from the detector in this state, the drift value of the detection signal can be confirmed, which can contribute to improving the accuracy of the measurement result.

  According to the present invention, since the light source is isolated from other device configurations and both are connected by the window member, even if a large light quantity lamp is employed as the light source, the thermal influence is blocked by the window member, It is possible to prevent other devices from being excessively heated. As a result, there is an effect that the measurement accuracy can be improved by reducing the drift of the detection signal due to the characteristic change of the apparatus itself due to the temperature rise or the optical path deviation due to the thermal deformation of the apparatus. In addition, since the light source and the other device configuration are separated by the window member, even if a cooling device such as an air cooling device is provided in the light source, the airflow circulated around the light source affects the other device configuration. There is an effect that fluctuation of the detection signal can be prevented.

Hereinafter, a glucose concentration measuring apparatus according to an embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, the glucose concentration measuring apparatus 1 according to the present embodiment has a light source 2 composed of an arc lamp or the like that generates light to irradiate the living body A, and a spectroscope that splits light emitted from the light source 2 The light emitted from the spectroscope 3, the reference light detector 4 for detecting the light emitted from the spectroscope 3, and the light emitted from the spectroscope 3 toward the living body A and diffused or transmitted in the living body A A measurement probe 5 that receives light outside the living body A, a signal light detector 6 that detects light received by the measurement probe 5, and a living body A based on the spectrum of the light detected by the signal light detector 6 And an arithmetic unit 7 for calculating the glucose concentration therein. The light source 2, the spectroscope 3, the reference light detector 4, the signal light detector 6, and the calculation unit 7 are accommodated in the main body casing 8.

  In the main casing 8, there is a partition wall 11 that partitions the light source unit 9 including the light source 2 and the optical unit 10 including the spectroscope 3, the reference light detector 4, the signal light detector 6, and the calculation unit 7 in a sealed state. Is provided. A through hole 12 is provided in a part of the partition wall 11. A window member 13 made of an optically transparent material, for example, a glass plate material, which closes the through hole 12 in a sealed state is disposed in the through hole 12.

  The window member 13 has an area larger than the opening area of the through hole 12 and is disposed so as to close the through hole 12. The window member 13 is covered with silicone rubber (elastic adhesive) 14 applied over the entire circumference of the through hole 12. By fixing to the partition wall 11, the through hole 12 is sealed so that air does not flow between the light source unit 9 and the optical unit 10.

The light source unit 9 is provided with an air cooling device 15 for supplying air adjusted to a predetermined temperature, for example, room temperature (20 to 28 ° C.) around the light source 2. The arc lamp as the light source 2 can irradiate a large amount of light. However, since the amount of heat generation is large, the wavelength characteristic may change due to heat generation. For this reason, by cooling with the air cooling device 15, the light of a fixed wavelength characteristic can be irradiated.
The light source 2 in the light source unit 9 and the spectroscope 3 in the optical unit 10 are arranged to face each other with the window member 13 interposed therebetween. The light emitted from the light source 2 passes through the window member 13 and is incident on the spectroscope 3 in the optical unit 10, where it is split and emitted toward the measurement probe 5 as light of a predetermined wavelength. It has come to be.

The spectroscope 3 is an acousto-optic variable wavelength filter (AOTF: Acoust-Optic) that further polarizes and emits only light of a specific wavelength of incident light according to the frequency of the input high-frequency signal.
Tunable Filter, hereinafter referred to as AOTF. ) 16 and a filter control unit 17 that supplies and controls a high-frequency signal to the AOTF 16.
The filter control unit 17 supplies a high frequency signal having a specific frequency to the AOTF 16. The frequency of the high frequency signal supplied from the filter control unit 17 to the AOTF 16 is sequentially changed at a predetermined speed.

  The filter control unit 17 supplies the high frequency signal to the arithmetic unit 7 described later in synchronization with the supply of the high frequency signal to the AOTF 16. In the figure, reference numeral 18 denotes an oscillator that generates a fundamental frequency of a high-frequency signal, and reference numeral 19 denotes an adder. As a result, the AOTF 16 and the calculation unit 7 are each input with a high-frequency signal having a frequency obtained by adding the fundamental frequency supplied from the oscillator 18 and the frequency supplied from the filter control unit 17.

  The polarized light output from the AOTF 16 is guided to the outlet of the main casing 8 by the optical fibers 20 and 21. The optical fiber 20 disposed at the outlet of the AOTF 16 is not particularly limited, but a multimode fiber or a bundle fiber having a relatively large core diameter is adopted in order to capture more measurement light from the light source. It is preferable.

  Further, between the optical fibers 20 and 21, there is provided a light branching section 22 that branches light incident from the AOTF 16 in two directions. For example, as shown in FIG. 2, the light branching unit 22 includes a collimating lens 23 disposed to face the end face of the optical fiber 20, and a beam that branches light collimated by the collimating lens 23 in two directions. The splitter 24 and the two condensing lenses 26 and 27 which condense the branched collimated light on the two optical fibers 21 and 25 are provided.

  One of the branched optical fibers 21 is connected to the outlet of the main casing 8, and the other optical fiber 25 is configured to guide the branched light to the reference light detector 4. The branching ratio of the beam splitter 24 in the light branching unit 22 is set so that, for example, the measurement light traveling toward the outlet side of the main body casing 8 is 95% and the reference light traveling toward the reference light detector 4 is approximately 5%. .

  A connector 28 is provided at the outlet of the main casing 8, and one optical fiber 21 branched at the light branching portion 22 is connected thereto. Further, a measurement probe 5 that is brought into contact with the surface of the living body A tissue is provided outside the main body casing 8, and the measurement probe 5 and the connector 28 are connected by an irradiation optical fiber 29. Connection of the optical fibers 21 and 29 in the connector 28 is performed by arranging the end faces of the optical fibers 21 and 29 having the same diameter core so as to abut each other. The end faces of the optical fibers 21 and 29 are, for example, PC-polished so that measurement light emitted from the end face of one optical fiber 21 can be efficiently delivered into the other optical fiber 29.

  As shown in FIG. 3, the measurement probe 5 has one irradiation optical fiber 29 at its center, as shown in FIG. 3, and a plurality of light receiving optical fibers 30 spaced around the periphery. Is arranged. That is, when the apparatus is operated with the distal end surface 5a of the measurement probe 5 in close contact with the surface of the living body A tissue, the measurement light emitted from the center of the measuring probe 5 enters the living body A and is diffused or transmitted. Then, the light returns to the surface of the living body A and is received as signal light by the light receiving optical fiber 30 disposed around the irradiation optical fiber 29.

  The distance between each light receiving optical fiber 30 and the irradiation optical fiber 29 is such that the measurement light emitted from the irradiation optical fiber 29 is received by the light receiving optical fiber 30 through a predetermined optical path length. Is set to In the case of the glucose concentration measuring apparatus 1 according to the present embodiment, the measuring light is arranged at a distance of about 0.4 to 0.8 mm so that the measuring light reaches the dermis region containing a lot of glucose. As a result, the signal light received by the light receiving optical fiber 30 contains a lot of light that has reached the depth of the dermis in the living body A tissue. The light receiving optical fiber 30 is bundled to form a fiber bundle, and is connected to the main casing 8 by another connector 31.

  The reference light detector 4 and the signal light detector 6 are, for example, PbS sensors or InGaAs sensors. As described above, the reference light detector 4 is disposed so as to face the end surface of one optical fiber 25 branched at the light branching section 22 via the lens 37, and the reference light emitted from the optical fiber 25. Is detected and a detection signal is output. Further, the signal light detector 6 is disposed opposite to the end face of the light receiving optical fiber 30 constituting the fiber bundle via the lens 37, and the signal received and propagated by the light receiving optical fiber 30 is transmitted. It detects light and outputs a detection signal.

  The arithmetic unit 7 amplifies the detection signal of the signal light detector 6 and the detection signal of the reference light detector 4 respectively, and outputs only a signal having a specific frequency from the electric signal output from the amplifier 32. Based on the lock-in detector 33 to be extracted, the A / D converter 34 that converts the electrical signal output from the lock-in detector 33 into a digital signal, and the digital signal output from the A / D converter 34 And a computer 35 for calculating the glucose concentration.

The lock-in detector 33 receives the high-frequency signal supplied from the filter control unit 17 and extracts from the electrical signal from the amplifier 32 only the electrical signal having a frequency component that matches the frequency of the high-frequency signal. It has become.
Further, the computer 35 outputs an output signal obtained by A / D-converting the electrical signal extracted by the lock-in detector 33 and the light emitted from the AOTF 16 corresponding to the frequency of the high-frequency signal supplied from the filter control unit 17. A wavelength signal is input.

Thereby, in the computer 35, the spectral distribution of the output signal obtained from the plurality of output signals obtained from the A / D converter 34 and the wavelength signal corresponding to each output signal obtained from the filter control unit 17 is obtained. Based on this, the glucose concentration is calculated from the output signal value in a specific wavelength region, for example, a region in the vicinity of the wavelength of 1600 nm.
The computer 35 is provided with a display (not shown) so that the glucose concentration value calculated by the computer 35 is displayed.

The operation of the glucose concentration measuring apparatus 1 according to this embodiment configured as described above will be described below.
In order to measure the glucose concentration of the body fluid in the living body A using the glucose concentration measuring apparatus 1 according to the present embodiment, the distal end surface 5a of the measuring probe 5 is brought into close contact with the living body A, for example, the surface of the fingertip. The measurement site may be a palm, a forearm or the like in addition to the fingertip.

  In this state, the light source 2 is operated. Since an arc lamp is used as the light source 2, a large amount of light is emitted from the light source 2. Further, when the light source 2 is operated, the light source 2 generates heat. According to the glucose concentration measuring device 1 according to the present embodiment, the light source 2 is cooled by operating the air cooling device 15 provided in the light source unit 9. Accordingly, it is possible to emit a large amount of light while suppressing fluctuations in wavelength characteristics due to temperature changes of the light source 2 itself.

  In this case, a cooling air flow is generated around the light source 2 in the light source unit 9 by the operation of the air cooling device 15. According to the glucose concentration measuring apparatus 1 according to the present embodiment, the light source unit 9 including the light source 2 and the optical unit 10 including other optical elements are partitioned by the partition wall 11, and thus circulates in the light source unit 9. The air flow and heat in the light source unit 9 are blocked by the partition wall 11 and are held so as not to leak into the optical unit 10. That is, since the air heated by the light source 2 is not circulated around the AOTF 16, the reference light detector 4, the signal light detector 6 and the like in the optical unit 10, the AOTF 16 and the like are not affected by the heat from the surroundings. In addition, it is possible to prevent a decrease in measurement accuracy due to temperature drift and characteristic fluctuation.

  On the other hand, the light emitted from the light source 2 passes through the window member 13 provided in the partition wall 11 and is incident on the AOTF 16. Since the window member 13 is disposed to face the light source 2, the window member 13 is heated by the radiant heat from the light source 2 and is thermally deformed. According to this embodiment, the window member 13 is not rigidly fixed to the partition wall 11 but seals the through hole 12 with the silicone rubber 14 applied over the entire circumference of the through hole 12 provided in the partition wall 11. Thus, even if the window member 13 is thermally deformed, the silicone rubber 14 is deformed to absorb the deformation of the window member 13 and an excessive stress is not generated in the window member 13. . Further, since the window member 13 and the through hole 12 are adhered in a sealed state by the silicone rubber 14, the inflow of air from the light source unit 9 to the optical unit 10 is blocked.

  In order to operate the AOTF 16, a high frequency signal having a frequency corresponding to the wavelength of the measurement light to be dispersed by the AOTF 16 is supplied from the filter control unit 17 to the AOTF 16. As a result, measurement light having a predetermined wavelength is split from the incident light and emitted.

  According to the glucose concentration measuring apparatus 1 according to the present embodiment, since the multimode fiber 20 is connected to the emission part of the AOTF 16, even if the emission angle of the measurement light fluctuates during the spectroscopy, or the optical system mechanically Even if misalignment or deformation occurs, the measurement light emitted from the AOTF 16 is incident on the multimode fiber 20 having a large core diameter without leakage. As a result, the light emitted from the light source 2 is sent to the measurement probe 5 without waste, so that the maximum amount of signal light obtained from the living body A can be ensured. In addition, there is an effect that the S / N ratio can be improved and the measurement accuracy can be improved by securing a large amount of received light.

  The measurement light emitted from the AOTF 16 is sent to the optical branching unit 22 through the optical fiber 20, and a part of the measurement light is branched using the optical branching unit 22 as reference light. The branched reference light is detected as it is by the reference light detector 4 disposed opposite to the end face of the reference optical fiber 25.

  The remaining measurement light from which the reference light is separated is incident on the optical fiber 21 by the condenser lens 26 and is incident on the irradiation optical fiber 29 of the measurement probe 5 connected by the connector 28. Since the connector 28 is connected in a state where the end faces of the optical fibers 21 and 29 having the same diameter core are in contact with each other, the transmitted measurement light does not leak to the outside, and the distal end face of the measurement probe 5 The light is emitted from 5a.

  The measurement light incident in the living body A collides with the living body A tissue and diffuses while traveling in the living body A. The measurement light absorbs light in a specific wavelength region according to the components of the living body A tissue and body fluid that pass therethrough. Therefore, the signal light that has been diffused in the living body A and returned to the surface of the living body A and emitted to the outside of the living body A has a reduced amount of light in a specific wavelength region according to the living body A tissue or body fluid that has passed through. It will be.

Since the light receiving optical fiber 30 has a fixed distance from the irradiation optical fiber 29 as described above, the light receiving optical fiber 30 receives signal light containing a large amount of light that has reached a depth corresponding to the distance. In the case of the present embodiment, the measurement light reaches the dermis region and then received by the light receiving optical fiber 30 as signal light, so that the received signal light contains a lot of glucose information.
The received signal light is returned into the main body casing 8 through the light receiving optical fiber 30 and detected by the signal light detector 6 disposed opposite to the end face of the light receiving optical fiber 30.

  When the output signals from the signal light detector 6 and the reference light detector 4 are input to the arithmetic unit 7, they are each amplified by the amplifier 32. The magnitude of the signal light detected by the signal light detector 6 varies with fluctuations in the intensity of the light incident on the living body A, that is, the measurement light emitted from the AOTF 16. Therefore, a part of the measurement light before entering the living body A is detected by the reference light detector 4 as the reference light, and is subtracted from the signal light received by the computer 35 described later, whereby the measurement light emitted from the AOTF 16 It is possible to eliminate fluctuations in signal light intensity due to fluctuations in intensity. In the glucose concentration measuring apparatus 1 according to the present embodiment, the branching ratio in the light branching unit 22 is set to about 95% measuring light and about 5% reference light, so that the measuring light is greatly attenuated in the living body A. By reducing the level difference between the obtained signal light and the reference light, it is possible to effectively eliminate fluctuations in the signal light intensity due to fluctuations in the intensity of the measurement light. In this case, the computer 35 may adjust the signal level by applying a predetermined coefficient to the output signal from the reference light detector 4.

  The output signals from the photodetectors 4 and 6 amplified in the amplifier 32 are passed through the lock-in detector 33, respectively. Thereby, only the output signal regarding the light of the wavelength corresponding to the high frequency signal input into AOTF16 from the filter control part 17 is extracted. Therefore, the extracted output signal includes only information on scattered light from the living body A having the same wavelength as that of the measurement light incident on the living body A, and excludes information on other wavelengths, for example, extraneous light. It is. As a result, generation of noise due to external light or the like can be suppressed.

  The output signals extracted by the lock-in detector 33 are converted into digital signals by the A / D converter 34 and input to the computer 35. The frequency of the high-frequency signal input from the filter control unit 17 to the AOTF 16 is sequentially changed, and the wavelength information of the measurement light incident on the living body A is sequentially supplied from the filter control unit 17 to the computer 35. Therefore, in the computer 35, wavelength characteristics indicating the relationship between the output signal and the wavelength information are required. Further, the computer 35 calculates the glucose concentration inside the living body A by obtaining an output signal value in a predetermined wavelength region, for example, a region near the wavelength of 1600 nm, among the obtained wavelength characteristics. Then, the calculated glucose concentration value is displayed on the display.

  As described above, according to the glucose concentration measuring apparatus 1 according to the present embodiment, since the arc lamp is employed as the light source 2, a large amount of light can be irradiated into the living body A. If the amount of light emitted toward the living body A is large, the amount of light that diffuses or permeates within the living body A and returns to the outside of the living body A can be increased, so that the amount of information can be increased and the measurement accuracy can be increased.

  Further, according to the glucose concentration measuring apparatus 1 according to the present embodiment, even if the calorific value is increased by employing a large light quantity arc lamp as the light source 2, the temperature of the light source 2 becomes excessive due to the operation of the air cooling device 15. Since it is configured not to rise, fluctuations in the wavelength characteristics of the light source 2 can be suppressed. Thereby, it is possible to prevent a decrease in measurement accuracy due to fluctuations in the wavelength characteristics of the light source 2 itself.

  Further, even if an air flow caused by the air cooling device 15 or an air flow due to the temperature rise of the light source 2 is generated, the optical unit 9 includes the partition wall 11 so that the air flow does not flow around the photodetectors 4 and 6 and the AOTF 16. Therefore, it is possible to prevent fluctuations in the characteristics of the components in the optical unit 10 due to the temperature rise of the light source 2.

  In addition, the light emitted from the light source 2 is not guided to the AOTF 16 by the optical fiber, but is allowed to pass through the window member 13 and enter the AOTF 16 by an aerial optical path. Compared with the case where the light is incident on the end face of the bundle, the light receiving area is not limited and the loss of light amount can be reduced.

  Furthermore, even if thermal deformation occurs due to radiant heat from the light source 2 on the window member 13 disposed facing the light source 2, the window member 13 is attached to the partition wall 11 with elastic silicone rubber 14, The thermal stress acting on the window member 13 is suppressed, and the occurrence of damage such as cracks can be prevented in advance. Therefore, even with a large amount of arc lamp, the glucose concentration can be measured with high measurement accuracy while maintaining a healthy state.

  Further, the optical branching unit 22 separates and detects a part of the measurement light as the reference light and takes a difference from the detected signal light, thereby measuring the signal light intensity due to the fluctuation of the measurement light intensity level. A decrease in accuracy can be suppressed. In addition, since the multimode fiber 20 is connected to the outlet of the AOTF 16, the light emitted from the AOTF 16 can be recovered without waste due to fluctuations in the emission angle of the AOTF 16, or mechanical deviations or deformations in the optical system. Can be sent to.

In addition, this invention is not limited to embodiment mentioned above.
First, an arc lamp with a large amount of light is used as the light source 2, but other lamps may be used instead. The present invention is particularly effective when employing the light source 2 that generates a large amount of heat and requires the air cooling device 15.
Secondly, the spectroscope 3 having a structure including the AOTF 16 is employed, but instead, a combination of a grating and a scan mirror may be employed.
Thirdly, the optical branching unit 22 has been described by exemplifying a combination of the collimating lens 23, the condensing lenses 26 and 27, and the beam splitter 24. However, instead of this, as shown in FIG. A structure branched by a coupler 36 may be used.

  Fourth, the window member 13 made of a single glass plate material is employed, but instead of this, as shown in FIG. 5, the window member made of two window member pieces 13a and 13b divided at the center. 13 may be adopted. In this case, the airflow passing between the end faces may be blocked by abutting the end faces of the window member pieces 13a and 13b against each other.

With this configuration, local thermal deformation that occurs in the central portion of the window member 13 that is closest to the light source 2 is released by the previously formed dividing line 13c, and excessive stress is generated in the window member 13. It is possible to prevent damage.
In addition, as shown in FIG. 6, it is also effective to incline the end surfaces 13d of the window member pieces 13a and 13b that abut each other in the thickness direction of the window member pieces 13a and 13b. With this configuration, the airflow passing through the window member 13 can be more reliably blocked, and even when the window member pieces 13a and 13b are displaced from each other due to the attached state or thermal deformation, the thickness is increased. It is possible to prevent the formation of a gap that penetrates straight in the vertical direction.

  Fifth, although the window member 13 made of an optically transparent glass plate material is adopted, instead of this, a glass plate material having a wavelength characteristic that allows only light in a specific wavelength region to pass is adopted. Also good. For example, the propagation of heat accompanying the passage of light from the light source unit 9 to the optical unit 10 is performed by prohibiting the passage of light having a wavelength of less than 1200 nm and allowing only light having a wavelength of 1200 nm or more to pass through. Can be suppressed. In addition to the above wavelength range, if the window member 13 prohibits the passage of light in a wavelength band that is unnecessary or harmful to the glucose concentration, it is unnecessary from the light detected by the photodetectors 4 and 6. It is possible to further improve the measurement accuracy by removing the components.

  In the glucose concentration measuring apparatus 1 according to the present embodiment, the output signals from the signal light detector 6 and the reference light detector 4 are amplified by separate amplifiers 32, respectively, and separate lock-in detectors 33 and A / Although it is input to the computer 35 via the D converter 34 and the difference processing is performed in the computer 35, instead of this, as shown in FIG. 7, by inputting to the differential amplifier 32 ′, The obtained difference signal may be input to the computer 35 via the single lock-in detector 33 and the A / D converter 34.

  Moreover, in the said embodiment, although demonstrated taking the example of the apparatus which guides the light radiate | emitted from the optical branching part 22 to the measurement probe 5 by the optical fibers 21 and 29, it replaces with this and is shown by FIG. As described above, a fiber bundle composed of a plurality of optical fibers 21 ′ and 29 ′ may be arranged on the output side of the optical branching section 22, and a plurality of measurement probes 5 ′ may be provided for each optical fiber 29 ′. In this way, the amount of light emitted from the arc lamp or the like is propagated as much as possible, and the diameter of the irradiation optical fiber 29 ′ of each measurement probe 5 ′ is reduced, so that the irradiation optical fiber 29 ′ can be reduced. The degree of progress of the light emitted into the living body A and returning to the light receiving optical fiber 30 can be limited to a narrow range.

Next, a glucose concentration measuring apparatus 40 according to a second embodiment of the present invention will be described below with reference to FIG. In the description of the glucose concentration measuring device 40 according to the present embodiment, the same reference numerals are given to portions having the same configuration as the glucose concentration measuring device 1 according to the first embodiment described above, and the description will be simplified. .
The glucose concentration measurement device 40 according to the present embodiment includes a control device 41 that operates the light source 2, the spectroscope 3, and the photodetectors 4 and 6 at predetermined time intervals, and thus the glucose concentration according to the first embodiment. This is different from the concentration measuring apparatus 1.

  The measurement of the glucose concentration is measured a plurality of times at time intervals in order to stabilize the measurement or to observe the change over time of the glucose concentration value in the living body A. The time interval may be a fixed time interval such as 5 minutes or 10 minutes, or may be performed at an indefinite time interval by the measurer.

  When the measurement is performed at a constant time interval, the control device 41 is programmed in advance with the measurement time or the measurement time interval, and when the measurement time is reached or when the measurement time interval elapses, the light source 2, the spectroscope 3 and the photodetectors 4 and 6 perform a measurement operation, and the living body A is irradiated with light. When measurement is performed at an indefinite time interval and led by the measurer, the measurer manually causes the light source 2, the spectroscope 3 and the photodetectors 4 and 6 to perform the measurement operation so that the light to the living body A is transmitted. Irradiation is performed.

  The glucose concentration measuring apparatus 40 according to the present embodiment has a predetermined time interval sufficiently smaller than the minimum measurement time interval, for example, 1 to 2, regardless of whether the measurement is performed at a constant time interval or an indefinite time interval. At the minute interval, the control device 41 is configured to cause the light source 2, the spectroscope 3, and the photodetectors 4 and 6 to perform measurement operations. That is, the glucose concentration measuring device 40 according to the present embodiment is configured to perform measurement when a predetermined time interval elapses even when the measurement time has not been reached, or even when the measurer does not perform the measurement operation manually. The light source 2, the spectroscope 3, and the photodetectors 4 and 6 are made to perform the same measurement operation as in FIG.

  According to the glucose concentration measuring apparatus 40 according to the present embodiment configured in this way, not only at the time of measurement, but each part of the apparatus is caused to perform the same measurement operation as at the time of measurement at a time interval shorter than the measurement time interval. At the time of measurement, the light source 2, the spectroscope 3, and the photodetectors 4 and 6 can be set to an equivalent temperature state. Further, not only the light source 2, the spectroscope 3, and the light detectors 4 and 6, but also optical components such as the optical fibers 20, 21, 29, 30 and the light branching portion 22 through which light passes when these are operated for measurement. However, it is possible to perform measurement at an equivalent temperature state.

As a result, it is possible to improve measurement accuracy by suppressing variations in measured values due to temperature drift of the photodetectors 4 and 6 due to heat generation, wavelength characteristic variation of the light source 2, and the like. In particular, when the measurement is continued for a long time with the patient lying on the bed like a bedside monitor, the thermal time constants of the light source 2, the spectroscope 3, the photodetectors 4, 6, and other optical components. On the other hand, it is effective to perform the measurement operation regularly at sufficiently short time intervals, so that highly accurate measurement can be performed under stable measurement conditions.
In addition to the measurement, the shorter the time interval for performing the measurement operation, the more effective the measurement can be performed at the same temperature state. In addition, a more stable temperature state at the time of measurement can be achieved by setting the time interval to zero and continuously performing the measurement operation.

  Next, a glucose concentration measuring apparatus 50 according to a third embodiment of the present invention will be described below with reference to FIG. In the description of the glucose concentration measuring device 50 according to the present embodiment, the same reference numerals are assigned to portions having the same configuration as the glucose concentration measuring devices 1 and 40 according to the above-described embodiments, and the description is simplified. .

The glucose concentration measuring device 50 according to the present embodiment is activated during the measurement operation performed separately from the measurement in the glucose concentration measuring device 40 according to the second embodiment, and the light from the light source 2 is applied to the living body A. Limiting means 51 that prohibits the light from being emitted is provided.
Specifically, as shown in FIG. 9, instead of the optical fiber 21 arranged at the outlet from the optical branching unit 22 of the glucose concentration measuring apparatuses 1 and 40 according to the first and second embodiments, An aerial optical path (outgoing optical path) 54 is formed by the pair of collimating lenses 52 and 53, and a limiting means 51 is provided in the aerial optical path 54. The limiting means 51 is arranged outside the aerial optical path 54 at the time of measurement, as shown by a chain line in the figure, and in the aerial optical path 54 as shown by a solid line in the figure at the time of a measurement operation performed separately from the measurement. And a shutter 55 that blocks the light.

  According to the glucose concentration measuring apparatus 50 according to the present embodiment configured as described above, the light from the light source 2 is emitted toward the living body A during the measurement operation other than the measurement by the operation of the shutter 55. prohibited. For example, when the measurement is continued intermittently for a long time with the patient wearing the measurement probe 5 like a bedside monitor, the light from the light source 2 is directed toward the living body A except during the measurement. It is preferable not to emit light. This is because, depending on the light output value of the light source 2, irradiation for a long time may adversely affect the living body A.

  According to the present embodiment, during the measurement operation other than the measurement time, the aerial optical path 54 is blocked by the shutter 55, so that the living body A is not irradiated with light. At the time of measurement, the shutter 55 is retracted out of the aerial optical path 54, so that the light from the light source 2 is emitted toward the living body A without being obstructed by the shutter 55. Therefore, according to the glucose concentration measuring apparatus 50 according to the present embodiment, there is an effect that stable measurement can be continued for a long time without adversely affecting the living body A.

  Next, a glucose concentration measuring apparatus 60 according to a fourth embodiment of the present invention will be described below with reference to FIG. In the description of the glucose concentration measuring device 60 according to the present embodiment, the same reference numerals are assigned to portions having the same configuration as the glucose concentration measuring devices 1, 40, and 50 according to the above-described embodiments, and the description is simplified. Turn into.

  In the glucose concentration measuring device 60 according to the present embodiment, a mirror 61 is disposed instead of the shutter 55 in the glucose concentration measuring device 50 according to the third embodiment, and the mirror 63 is disposed in the incident light path 62 of the signal light detector 5. And a filter 64 is arranged between the mirrors 61 and 63. Similar to the shutter 55 in the third embodiment, the mirror 61 is disposed outside the aerial optical path 54 during measurement, and light from the light source 2 is emitted toward the living body A, as indicated by a chain line in the drawing. And is arranged in the aerial optical path 54 to block light from being emitted toward the living body A, as shown by a solid line in the figure, during a measurement operation other than the measurement. Reflects in the direction. In the figure, the mirror 61 is set to be inclined by 45 ° with respect to the aerial optical path 54 and is configured to reflect light in a direction refracted by 90 °.

  Further, at the time of measurement, the mirror 63 is also arranged outside the incident optical path 62 of the signal light detector 6 and detects the light incident on the incident optical path 62 from the living body A side, as indicated by a chain line in the figure. In the measurement operation other than at the time of measurement, the light is disposed in the incident light path 62 and reflected by the mirror 61 in the direction changed by 90 ° angle, during the measurement operation other than the measurement time. So that the light is reflected on the incident light path 62 of the signal light detector 6 and is further refracted by 90 °. That is, the mirror 63 constitutes a bypass means for making the signal light detector 6 bypass the light without entering the living body A.

  Further, the filter 64 is configured to attenuate and emit the light reflected by the mirror 61 when passing the light. The attenuation rate of the filter 64 is set to an attenuation rate equivalent to the attenuation rate when diffused or transmitted through the living body A, for example.

According to the glucose concentration measuring device 60 according to the present embodiment configured as described above, light from the light source 2 is emitted during the measurement operation other than the measurement, similarly to the glucose concentration measuring device 50 according to the third embodiment. It is prevented from being emitted toward the living body A, and emission of light to the living body A is allowed at the time of measurement.
In a measurement operation other than the measurement operation, the light emitted from the light source 2 is split by the AOTF 16, passes through the light branching unit 22, is reflected by the mirror 61, and passes through the filter 64. The light incident on the filter 64 is attenuated at an attenuation rate equivalent to that diffused or transmitted in the living body A by being passed through the filter 64, and then incident on the signal light detector 6 by the mirror 63. It returns to the optical path 62 and enters the signal light detector 6.

  That is, not only at the time of measurement but also at the time of the measurement operation other than the time of measurement, the light source 2, the spectroscope 3, and the photodetectors 4 and 6 are powered on in the same manner as the glucose concentration measuring device 40 according to the second embodiment. The measurement operation equivalent to that at the time of measurement is performed, and similarly to the glucose concentration measurement device 50 according to the third embodiment, irradiation of light to the living body A at the time of non-measurement is prohibited. Furthermore, according to the glucose concentration measuring apparatus 60 according to the present embodiment, even during continuous or intermittent measurement operation other than during measurement, the signal light detector 6 is diffused or transmitted in the living body A in the same manner as during measurement. Since light equivalent to the incident light is incident, the signal light detector 6 can be placed in an actual measurement state. As a result, it is possible to more reliably prevent a decrease in measurement accuracy due to variations in measurement conditions.

  In the glucose concentration measuring apparatus 60 according to the present embodiment, a filter 64 having an attenuation factor equivalent to that of the living body A is adopted, but instead, a filter capable of changing the attenuation factor is adopted. Also good. That is, since the light attenuation rate in the living body A differs depending on the individual difference of the living body A, it is effective to make the attenuation rate adjustable according to the individual difference.

  Specifically, a plurality of filters having different attenuation factors may be arranged so as to be replaceable, or the attenuation factors may be changed in accordance with a command signal like a liquid crystal filter. For example, the intensity of light detected by the signal light detector 6 and the reference light detector 4 at the time of measurement is stored, and the attenuation rate of the living body A is calculated each time based on the detection results of these light detectors 4 and 6. The command signal may be sent to the filter.

In each of the above embodiments, as shown in FIG. 12, a shutter 70 capable of blocking light incident on these detectors 4 and 6 immediately before the signal light detector 6 and the reference light detector 4. May be provided. The operation of the shutter 70 can block the incidence of light on the photodetectors 4 and 6 immediately before the photodetectors 4 and 6. 6 can be more reliably prevented.
Then, by acquiring the outputs of the photodetectors 4 and 6 in a state in which the incidence of light when the shutter 70 is operated is interrupted, the drift value of the detection signal can be accurately measured. It is possible to improve the measurement accuracy by using the evaluation of the measurement result. The measurement of the drift value of the detection signal may be performed every measurement of the glucose concentration or periodically.

It is the schematic which shows the whole structure of the glucose concentration measuring apparatus which concerns on one Embodiment of this invention. It is the schematic explaining the light branching part of the glucose concentration measuring apparatus of FIG. It is a figure which shows the measurement probe front end surface of the glucose concentration measuring apparatus of FIG. It is the schematic which shows the modification of the optical branching part of FIG. It is a front view which shows the modification of the window member provided in the partition of the glucose concentration measuring apparatus of FIG. It is a longitudinal cross-sectional view which shows the other modification of the window member provided in the partition of the glucose concentration measuring apparatus of FIG. It is the schematic which shows the modification of the glucose concentration measuring apparatus of FIG. It is the schematic which shows the other modification of the glucose concentration measuring apparatus of FIG. It is the schematic which shows the whole structure of the glucose concentration measuring apparatus which concerns on 2nd Embodiment of this invention. It is the schematic which shows partially the glucose concentration measuring apparatus which concerns on 3rd Embodiment of this invention. It is the schematic which shows partially the glucose concentration measuring apparatus which concerns on 4th Embodiment of this invention. It is the schematic which shows the modification of the glucose concentration measuring apparatus which concerns on each embodiment of this invention.

Explanation of symbols

A Living body 1,40,50,60 Glucose concentration measuring device 2 Light source 3 Spectrometer 4,6 Photodetector (detector)
DESCRIPTION OF SYMBOLS 9 Light source part 10 Optical part 11 Partition 12 Through-hole 13 Window member 13a, 13b Window member piece 14 Silicone rubber (elastic adhesive)
15 Air Cooling Device 41 Control Device 51 Limiting Means 54 Aerial Light Path (Outgoing Light Path)
55 Shutter 61 Mirror 63 Mirror (Bypass means)
64 Filter 70 Shutter (light blocking means)

Claims (15)

A light source comprising a lamp, a spectroscope for spectrally separating the light emitted from the light source, and a detector for detecting light diffused or transmitted in the living body after being dispersed in the spectroscope, the absorbance at each wavelength A glucose concentration measuring device for measuring a glucose concentration in a living body based on
The light source unit that houses the light source and the optical unit that houses the spectroscope and the detector are mutually partitioned by a partition,
The glucose concentration measuring device, wherein the partition wall is provided with an optically transparent window member that transmits light from the light source of the light source unit and enters the spectroscope.   The glucose concentration measuring apparatus according to claim 1, wherein the light source is an arc lamp.   The glucose concentration measuring apparatus according to claim 1, wherein the light source unit includes an air cooling device that cools the light source.   The glucose concentration according to any one of claims 1 to 3, wherein the window member seals the through hole in a sealed state with an elastic adhesive applied over the entire circumference of the through hole provided in the partition wall. measuring device.   The glucose concentration measuring device according to any one of claims 1 to 4, wherein the window member is composed of a plurality of window member pieces arranged in a state in which end faces thereof are butted together.   The glucose concentration measuring apparatus according to claim 5, wherein end surfaces of the window member pieces that are brought into contact with each other are inclined in a thickness direction of the window member pieces.   The glucose concentration measuring device according to any one of claims 1 to 6, wherein the window member has a wavelength characteristic that transmits only light in a specific wavelength region. A light source, a spectroscope that separates light emitted from the light source before or after entering the living body, and a detector that detects light diffused or transmitted in the living body, and is generated based on the absorbance at each wavelength. A glucose concentration measuring device for measuring glucose concentration in the body,
A glucose concentration measurement apparatus comprising a control device that performs a measurement operation at a predetermined time interval shorter than the measurement interval separately from the measurement performed at a time interval. A light source, a spectroscope that separates light emitted from the light source before or after entering the living body, and a detector that detects light diffused or transmitted in the living body, and is generated based on the absorbance at each wavelength. A glucose concentration measuring device for measuring glucose concentration in the body,
A glucose concentration measurement apparatus comprising a control device that continuously performs a measurement operation between measurements performed at intervals of time.   The glucose concentration measuring apparatus according to claim 8 or 9, further comprising a limiting unit that is activated during a measurement operation performed separately from the measurement and prohibits light from the light source from being emitted toward the living body.   The glucose concentration measuring apparatus according to claim 10, wherein the restricting unit includes a shutter that blocks an outgoing optical path to a living body during a measurement operation performed separately from the measurement.   A mirror that is arranged in an outgoing light path to the living body and reflects light in a predetermined direction during a measurement operation performed separately from the measurement, and a filter that attenuates the light reflected by the mirror; The glucose concentration measuring apparatus according to claim 10, further comprising bypass means for allowing light transmitted through the filter to enter the detector.   The glucose concentration measuring apparatus according to claim 12, wherein the filter has an attenuation rate equivalent to that of a living body.   The glucose concentration measuring apparatus according to claim 12, wherein the filter is a variable filter whose attenuation rate can be changed, and the attenuation rate is changed in accordance with the attenuation rate of a living body.   The glucose concentration measuring apparatus according to any one of claims 1 to 14, wherein a light shielding means capable of blocking light incident on the detector is provided immediately before the detector.

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