JPH11155844A - Living body measuring device with constant living body contact area - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a living body measuring device with a constant contact area with a living body. SOLUTION: With this measuring device, infrared rays are applied to a living body 4 through an ATR crystal 1 to be total-reflected, and then the infrared rays are detected to measure the living body 4 from the absorptivity thereof. In this case, masking 2 is applied to the surface of the ATR crystal 1, thereby partitioning such a measurement area 3 as to always obtain a constant living body contact area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a living body measuring apparatus for non-invasively measuring components in a living body.

[0002]

2. Description of the Related Art Conventionally, when measuring an in-vivo component,
Blood, body fluid or urine is collected from a living body and subjected to component analysis using various biochemical techniques. For example, as a method for obtaining a glucose component in blood, an enzyme electrode method, a colorimetric method, and the like have been used and have been put to practical use.

[0003] However, when blood, body fluid or urine is collected from a living body, there is a risk of infection and disposal as well as suffering from the living body. In addition, the labor and time required for the inspection cannot be ignored.

[0004] In view of the above, a total reflection absorption measurement method (AT) for non-invasively analyzing components in a living body without collecting blood or the like from the living body and supporting various diagnoses and preventions has been proposed.
Various biometric devices based on the R (Attenuated Total Reflection) method have been proposed. For example, JP-A-7-1848
No. 83 discloses an example of such a living body measuring device.

[0005]

However, in the conventional apparatus as described above, since the surface of the ATR crystal that comes into contact with the living body is all the measurement area, when a finger or the like is brought into close contact with the surface of the ATR crystal, Since the contact area varies depending on the shape of the finger and the pressing pressure, the irradiation area varies, and as a result, the detection intensity (absorbance) changes, and it is not easy to obtain a measurement result with good reproducibility. Did not.

The present invention has been made in view of such circumstances,
It is an object of the present invention to provide a living body measuring device having a constant contact area with a living body.

[0007]

According to the present invention, means for solving the above-mentioned problems are constituted as follows. That is, the living body is irradiated with infrared light through the ATR crystal and totally reflected, and then the infrared light is detected, and the biological measurement device is configured to calculate the concentration of the in-vivo component from the absorbance. The surface of the ATR crystal is masked to define a measurement area that can always provide a constant biological contact area.

[0008] By masking the surface of the ATR crystal to define a measurement area with a precision that can always obtain a constant living body contact area, even if the shape of the living body or the pressing pressure is different, the detection intensity changes. And a measurement result with good reproducibility can be obtained.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the living body measuring apparatus with a constant living body contact area according to the present invention will be described below in detail. FIG. 1 is a configuration diagram of a living body measuring device (hereinafter, referred to as a device) at the time of measurement, and FIG. 2A is a masked ATR.
FIG. 1B is a perspective view of the crystal, and FIG. 2B is a correspondence diagram of the masking and the ATR crystal. In these figures, reference numeral 1 denotes an ATR crystal, 2 denotes masking formed on the surface of the ATR crystal 1,
Reference numeral 3 denotes a measurement area defined inside a circular hole 21 opened in the masking 2, 4 denotes a fingertip (living body) of a human body placed in the measurement area 3, 5 denotes an infrared irradiation device, and 6 denotes infrared detection. The device 7 is an arithmetic processing unit composed of a CPU.

In this apparatus, the total reflection absorption measurement method (ATR)
Method), the infrared light (wavelength of 1 μm or more) emitted from the infrared irradiation device 5 travels while totally reflecting the ATR crystal 1, and slightly reflects on the living body 4 when it is totally reflected on the living body 4 side. It penetrates inside and is absorbed by certain biological components. For example, if 9.66 μm is selected and irradiated as the wavelength of infrared light, it is absorbed by glucose in blood. Accordingly, the intensity of the absorbed infrared rays is detected as an infrared absorption spectrum (measurement spectrum) by the infrared ray detecting device 6 and the absorbance is obtained. , Ie, the blood glucose level.

In the above-described process of total reflection, if the living body contact area differs for each measurement, the irradiation area also differs.
Although the concentration cannot be detected accurately, in this apparatus, the measurement area 3 defined by the masking 2 on the surface of the ATR crystal 1 is always large enough to obtain a constant biological contact area (for example, 0.5 to 1. By setting the diameter to about 0 cm ² ), regardless of the size of the living body 4 and regardless of the pressing pressure of the living body 4, the irradiation area is kept constant so that the detection intensity does not change. And a highly reliable measurement value can be obtained.

The material of the masking 2 for defining the above-mentioned measurement area 3 has a low characteristic absorption in the infrared region,
In particular, a stable material having no characteristic absorption in the infrared absorption region of glucose is preferable. For example, polytetrafluoroethylene (trade name: Teflon) or aluminum or the like may be used as a vapor-depositable metal.

The measurement site of the living body 4 is preferably a site having a thin stratum corneum such as an earlobe in addition to the fingertip, but is not particularly limited. Further, the measurement target is not limited to the glucose concentration, and may be, for example, uric acid, cholesterol ester, fatty acid, or the like.
9.71 μm, 2.94-3.13 μm for uric acid,
5.75 to 5.76 μ for cholesterol ester
m, 3.33 to 3.57 μm is appropriate for fatty acids. These spectra are less complicated and easier to analyze than those in the near infrared region. In addition, the absorbance near the peak and the concentration of the in-vivo component are in a correlation with each other, and by utilizing this point, by preparing a relational expression between the concentration and the absorbance in advance, from the obtained absorbance as described above. And the concentration of each in-vivo component can be determined.

[0014]

As described above, according to the living body measuring apparatus of the present invention having a constant living body contact area, by masking the surface of the ATR crystal, a constant living body contact area can always be obtained. Because it defines the measurement area of
The irradiation area can be kept constant, the detection intensity can be kept unchanged even if the shape, size, and pressing pressure of the living body are different, and highly reliable and accurate measurement can be performed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram at the time of measurement showing an embodiment of a living body measuring device according to the present invention in which a living body contact area is constant.

FIG. 2A is a perspective view of an ATR crystal subjected to the masking, and FIG. 2B is a perspective view of the ATR crystal having the masking.

[Explanation of symbols]

1 ATR crystal, 2 masking, 3 measurement area, 4
... living body.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takayoshi Yuzu 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. Inside

Claims (1)

[Claims] 1. A living body measuring apparatus which irradiates a living body with infrared light through an ATR crystal and totally reflects the infrared light, detects the infrared light, and obtains the concentration of a component in the living body from the absorbance. A biometric device having a constant biocontact area, characterized in that a masking is applied to the surface of the ATR crystal to define a measurement area in which a constant biocontact area is always obtained.