JP2002350338A - Blood sugar level meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a means utilizing other light sources such as a laser diode, etc., which are not conventionally used as the light source in a spectroscopic apparatus, particularly an optical blood sugar level nondestructive measuring apparatus. SOLUTION: The method that a spectroscopic characteristic of the light source is reflected in an analytical curve by using a reference material, overcomes a problem that the spectroscopic characteristic depends on the environment. The use of an optical product such as an optical fiber, etc., overcomes a problem that a plurality of light paths from a plurality of the light sources are different per light source.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for measuring the sugar content (blood sugar level) in blood from optically collected blood from a human body or directly from a human body without blood collection.
It relates to a blood glucose meter.

[0002]

2. Description of the Related Art Spectroscopic analysis is a method of determining the concentration of a certain component of a substance by an optical method. Irradiate the sample (including the human body) to be measured with light containing several wavelengths,
By measuring the amount of transmitted light or reflected light and calculating how much light of which wavelength is absorbed when passing through the inside of the sample, a specific component of the sample is calculated using a previously prepared calculation method. This is a method for determining the concentration of

[0003] Mitsuhiko Noda and his colleagues are researching noninvasively measuring blood glucose levels using spectroscopic analysis (Japanese Patent No. 30938).
No. 71).

In the future, it is desired that an optical blood glucose level non-destructive measuring device be carried by each diabetic patient and be easily and accurately measured when necessary.

[0005]

However, in the currently known method, a halogen lamp is used as a light source, which is limited in terms of miniaturization, low cost, low power consumption, and is portable. No commercialization by specification has been realized.

[0006]

In order to solve this problem, in the blood glucose meter of the present invention, a light source having a narrow wavelength range of emitted light, such as a laser diode or a light emitting diode, is used as a light source. Was. Laser diodes, light-emitting diodes, and the like are small, low-priced, and have low power consumption, and thus are optimal for commercialization of portable blood glucose meters.

However, in this case, since the spectral characteristics of the light source, such as the wavelength of the emitted light or the output of the emitted light, depend on the state of the light source itself or the environment where the light source is placed, the light source emits light. The spectral properties of light must be reflected in some way.

The problem is that a constant output circuit is prepared so that the output of the light emitted from the light source does not depend on the wavelength, and the light emitted from the light source is applied to the sample or switched instantaneously to smoothly absorb the light. The problem can be solved by irradiating a reference substance having a spectrum (for example, a resin-based material such as a fluororesin) and measuring the absorption amount. If the wavelength changes, the amount of absorption by the reference substance changes,
From the amount of change, it is estimated how much the wavelength has changed.

[0009] Further, unlike a case where a halogen lamp is used, light of all wavelengths required for measurement cannot be covered by one light source, so that a plurality of light sources are required. The light emitted from the light source must have a common optical path before being irradiated on the sample.

[0010] This problem can be solved by using an optical product such as an optical fiber or a half mirror. As a method of using an optical fiber, a bundle of many thin optical fibers is used.
A plurality of light sources are arranged on respective optical paths, and light emitted from the light sources is made incident on the bundled optical fibers. The plurality of bundled optical fibers may be randomly bundled into one optical fiber on the emission side.

By using the above method, a conventional measuring instrument using spectroscopic analysis can use a light source other than a halogen lamp, such as a laser diode or a light emitting diode.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

FIG. 1 shows a state in which light is applied to a fingertip, the transmitted light is measured, and the glucose concentration in blood is measured. At that time, the irradiation light is sequentially emitted from the light sources 2 such as a plurality of laser diodes and light emitting diodes in a short time, and the output of the light is kept constant by the output constant circuit 1. The optical path shared by the optical fiber 3 is divided into two optical fibers in order to correct for changes in spectral characteristics such as the wavelength and output of the light source. Material 5 is also irradiated. The transmitted light is measured by the light receiving element 6.

The light emitted from the light source and having a constant output changes its wavelength due to a change in environment such as temperature. The change in the wavelength can be estimated by a change in the amount of absorption by the reference substance. By substituting the measurement values obtained from the light receiving elements in this way into a previously prepared equation (calibration curve) by a multivariate analysis technique, the concentration is calculated.

When the constant output circuit is not used, the output itself changes according to the wavelength. However, if a calibration curve can be created in consideration of the change, this may be used.

Since the change in the wavelength of the light source often largely depends on the temperature of the light source, depending on the type of the light source,
In some cases, a change in wavelength can be estimated with high accuracy even by a temperature sensor.

The method of making the optical paths of light from different light sources common can be realized by using an optical product such as a half mirror in addition to the above-mentioned optical fiber.

A blood glucose meter can be measured not only from a fingertip but also from transmitted light or reflected light from another body part such as an earlobe.

[0019]

As described above, according to the present invention, with respect to a blood glucose meter in which only a halogen lamp was considered as a light source, a laser diode, a light emitting diode, etc.
Light sources that depend on the environment, such as ambient temperature, can also be used. If a light source having a narrow wavelength range of emitted light is used, a spectroscopic mechanism is not required.

As a result, downsizing, low cost, and low power consumption are realized, and portability of the blood glucose meter can be realized.

When blood is collected and measured in a cell or the like, factors that complicate the light absorption of sugar can be neglected, and it is clear that further effects can be expected.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a blood glucose meter using a transmission method for a fingertip.

[Explanation of symbols]

 Reference Signs List 1 constant output circuit 2 light source such as laser diode or light emitting diode 3 optical fiber 4 sample (fingertip) 5 reference substance 6 light receiving element 7 Arithmetic circuit including calibration curve

Continued on the front page F term (reference) 2G045 AA01 CA25 DA31 FA12 2G059 AA01 BB13 CC16 EE01 EE02 FF08 GG01 GG02 JJ17 JJ22 KK01 MM12 MM14 NN01 NN02 4C038 KK10 KL05 KL07 KM00 KX02 KY01 KY03 KY03

Claims (13)

[Claims] 1. A blood glucose meter for measuring a sugar content or a glucose concentration in blood collected by an optical method, comprising at least two light sources having a narrow wavelength range of emitted light. Total. 2. A blood glucose meter for measuring a sugar content or a glucose concentration in blood collected by an optical method, comprising two or more laser diodes and light emitting diodes. 3. A blood glucose meter for measuring a sugar content or a glucose concentration in blood collected by an optical method, wherein a spectral characteristic such as a wavelength of emitted light or an output of the emitted light indicates a state of the light source itself, Alternatively, a blood glucose meter having a light source depending on an environment where the light source is placed. 4. The method according to claim 1, wherein the sugar content in the blood of the human body is determined by an optical method.
Alternatively, in a blood glucose meter that measures glucose concentration without collecting blood, a light source with a narrow wavelength range of emitted light is used.
A noninvasive blood glucose meter characterized by having at least one. 5. The method according to claim 1, wherein the sugar content in the blood of the human body is determined by an optical method.
Alternatively, a non-invasive blood glucose meter that measures two or more laser diodes or light-emitting diodes in a blood glucose meter that measures glucose concentration without collecting blood. 6. The sugar content in the blood of a human body by an optical method,
Alternatively, a blood glucose meter that measures glucose concentration without collecting blood has a light source whose spectral characteristics, such as the wavelength of emitted light or the output of emitted light, depend on the state of the light source itself or the environment where the light source is placed. A non-invasive blood glucose meter characterized by the following. 7. The blood glucose meter according to claim 1, further comprising means for correcting a change in spectral characteristics such as a wavelength and an output of a light source. 8. The blood sugar according to claim 1, further comprising means for sharing an optical path when light emitted from a plurality of light sources is emitted to the measuring unit. Value meter. 9. A means for correcting a change in spectral characteristics such as a wavelength and an output of a light source, and a means for sharing an optical path when light emitted from a plurality of light sources is applied to a measurement unit. The blood glucose meter according to any one of claims 1 to 6, comprising: 10. The blood glucose meter according to claim 7, wherein a means for detecting a change in spectral characteristics such as a wavelength and an output of the light source includes a substance having a different absorption amount according to the wavelength of the light. . 11. A device according to claim 7, further comprising a sensor for measuring a temperature of the light source itself or an ambient temperature of the light source as means for detecting a change in spectral characteristics such as a wavelength and an output of the light source. Blood glucose meter. 12. An optical product such as an optical fiber or a half mirror as means for sharing an optical path when light emitted from a plurality of light sources is emitted to a measuring unit. 10. The blood glucose meter according to 8 or 9. 13. A measuring instrument for measuring the concentration of a certain component of a substance by an optical method, wherein two or more laser diodes or light emitting diodes are used, and correction is made for changes in spectral characteristics such as the wavelength and output of the light source. And a means for sharing an optical path when light emitted from a plurality of light sources is emitted to a measurement unit.