JPH05277118A - Standard device for origin of light absorbance of optical measuring instrument - Google Patents

Abstract

PURPOSE:To simplify the construction of the standard device for the origin of light absorbance used for an optical measuring instrument which measures the optical characteristics of a light scatterable sample by constituting the standard device for the origin of the light absorbance of a milk white light scattering plate and pressing the light transmission terminal and light receiving terminal of the optical measuring instrument to the surface of the light scatterable plate. CONSTITUTION:The standard device 1 for the origin of the light absorbance is constituted by sticking a neoprene rubber plate 4 colored black on the rear surface of a polyacetal resin plate 2 which is the light scattering plate. In such a case, the thickness L of the polyacetal resin plate 2 is set by the desired absorbance. The light transmission part 8 provided at the front end of a light guide 6 for light transmission from the optical measuring instrument body and the light receiving part 12 at the front end of a light guide 10 for light reception for introducing the received light to the optical measuring instrument body are pressed to the surface of the polyacetal resin plate 2. As a result, the presence or absence of the abnormality of the fiber part or light source part, etc., of the optical measuring instrument is easily checked.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical measuring device for measuring optical characteristics of a light-scattering sample, such as a device for measuring metabolism in a living body by using light, which is used for determining the origin of absorbance. It is about.

[0002]

2. Description of the Related Art Since light having a wavelength of 700 to 1000 nm passes through a living body more easily than light having other wavelengths, hemoglobin, oxyhemoglobin, and cytochrome aa ₃ having absorption bands in this wavelength range can be measured non-invasively. Has been attempted (for example, Japanese Patent Publication No. 61-11614, "Pediat
rics ” 75 , 217-225 (1985),“ artificial organ ” 19 , 535-538 (1990)).

Only the change in absorbance is required in these measurements, and in order to obtain the absolute value of absorbance, a method of calibrating the origin of absorbance must be determined. When the measurement target is not a biological sample but a chemical substance, the transmission spectroscopic measurement uses a liquid that does not contain any measurement components (for example, distilled water) as the origin of absorbance 0, and the reflectance for measuring cloth or printed matter. 100
It is well known to use barium sulphate powder as a% basis. However, as an origin reference of the absorbance suitable for applying to a device that irradiates light from a part of a light-scattering sample such as a biological sample that is the subject of the present invention and detects light emitted from another part, It has a scattering transmission characteristic similar to that of a living organism, and has the same light attenuation rate as the target sample (for example, 1
It is desirable to have a criterion that satisfies / 10 ³ to 1/10 ⁷ and an absorbance of 3 to 7) and has little change over time.

As an absorbance origin standard instrument having a light attenuation rate similar to that of a living body and capable of obtaining an origin of absorbance measurement independent of a patient, a light input section made of a light scatterer,
There has been proposed a device including a light output part made of a light scatterer and a coupling part which connects both parts and has a dimming function (Japanese Patent Laid-Open No. Hei 4).
-84959 gazette).

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to make an absorbance origin standard device used in an optical measuring device for measuring the optical characteristics of a light scattering sample into a simple structure.

[0006]

The standard apparatus for origin of absorbance of the present invention comprises a milky white light scattering plate, and the light transmitting end and the light receiving end of the optical measuring device are in contact with the surface thereof for use. In a preferred embodiment, a light absorber is provided on the back surface of the light scattering plate.

[0007]

[Function] By changing the thickness of the light-scattering plate, the amount of light attenuation from the light incident point to the detection point can be changed, and the same amount of attenuation as that of a living body such as a human body to be measured is set. be able to. As the milky white light scattering plate, for example, a milky white resin plate can be used, and specific examples thereof include a polyacetal resin plate (trade name: Duracon), a polypropylene resin plate, a polytetrafluoroethylene resin plate, a polystyrene foam resin plate, etc. Can be used. A black plate can be used as the light absorber, and as a specific example, a black-colored neoprene rubber plate, a black-anodized aluminum plate, a box whose inside is painted black, or the like can be used. ..

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows an embodiment. The absorbance origin standard device 1 uses DURACON (trade name) which is a polyacetal resin as the light scattering plate 2, and has a black-colored neoprene rubber plate 4 attached to the back surface thereof. The thickness L of the polyacetal resin plate 2 is set according to the desired absorbance. The size of the polyacetal resin plate 2 is, for example, 50 mm
A size of about 80 mm is suitable. The thickness of the neoprene rubber plate 4 is not particularly limited and is, for example, 3 mm. On the surface of the polyacetal resin plate 2, a light transmitting unit 8 provided at the tip of a light guide 6 for transmitting light from the light measuring device body, and a tip of a light receiving light guide 10 for guiding the received light to the light measuring device body. The light receiving portion 12 is brought into contact with the light receiving portion 12. The distance between the light transmitting unit 8 and the light receiving unit 12 is set to the same distance as when the measurement is performed by mounting the light transmitting unit 8 and the light receiving unit 12 on an object to be measured such as a human body. For example, the distance is 44 mm. ..

Using this absorbance origin standard device 1, a light transmitting unit 8
FIG. 2 shows the relationship between the thickness L of the polyacetal resin plate 2 and the absorbance when the distance between the light receiving part 12 and the light receiving part 12 is set to 44 mm. L
Is small, the absorption of light by the neoprene rubber plate 4 is large, so that the absorbance is large, and as L becomes larger, the influence of the absorption of light by the neoprene rubber plate 4 becomes smaller and the absorption becomes smaller, and eventually the polyacetal resin. The absorbance is determined by the plate 2 itself. Since the absorbance when the light transmitter 8 and the light receiver 12 are brought into contact with the head of the human body at an interval of 44 mm is about 5.0, the thickness L of the polyacetal resin plate 2 in this standard device 1 is about 8 mm. It is appropriate to set to.

An example in which the origin of the absorbance of the oxygen monitor for a living body is determined by using the standard device of this embodiment and actual measurement is carried out is shown in FIG.
Will be described with reference to FIG. FIG. 3 represents the calibration. Reference numeral 26 denotes a living body oxygen monitor main body, which is provided with a light sending light guide 6 for sending light to the measurement target and a light receiving light guide 10 for receiving light from the measurement target. A light transmitting unit 8 that irradiates an object with light is provided at the tip of the guide 6, and a light receiving unit 12 that receives light from the object is provided at the tip of the light receiving light guide 10. In order to perform the calibration, the light transmitting unit 8 and the light receiving unit 12 are mounted on the polyacetal resin plate 2 of the absorbance origin standard 1 of this embodiment with a predetermined distance (for example, 44 mm). 28 is an operation key of the oxygen monitor main body 26, and 30 is a display liquid crystal panel.

The absorbance is measured in this state. First, confirm that the absorbance is within the preset absorbance range, and confirm that the device is normal. Also,
At the same time, calibration is performed inside the oxygen monitor so that the absorbance output including the automatic gain setting becomes zero. When the absorbance is measured at a plurality of wavelengths, calibration is performed so that the absorbance output at each of the plurality of wavelengths becomes zero.

Next, as shown in FIG. 4, the light-transmitting portion 6 of the light-transmitting light guide and the light-receiving portion 12 of the light-receiving light guide 10 are attached to the patient to be measured, and the absorbance is measured. 32 is a recorder. Absolute absorbance of the patient can be obtained by adding the absorbance value of the absorbance origin standard device 1 to the absorbance output at that time. If the measurement is performed at a plurality of wavelengths, the absolute absorbance at each wavelength can be obtained. This allows an approach to see the differences between patients.

FIG. 5 shows another embodiment.
As a light absorber provided on the back surface of the light scattering plate 2, a box 24 in which light from the outside is prevented is used instead of a black plate, and the inside of the box 24 is black. Box 24
The inside of may be hollow. The length and width of 2 are 50 mm x 8
About 0 mm is suitable. FIG. 6 shows an example in which the absorbance origin standard device 1 is built in the oxygen monitor main body 26, whereby the origin of absorbance can be easily calibrated.

[0014]

In the present invention, since the milk-white light scattering plate is used as the standard for the origin of absorbance, it is possible to easily obtain a specific absorbance by setting the thickness thereof. It becomes easy to confirm whether or not the light source unit is abnormal. In addition, since it is possible to standardize regardless of the individual patient, it is possible to see the difference for each patient. In particular, since the standard device of the present invention has a simple structure, it is inexpensive and can be easily manufactured.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment.

FIG. 2 is a diagram showing the relationship between the thickness of a polyacetal resin plate and the absorbance in the same example.

FIG. 3 is a perspective view showing a state in which the origin of absorbance is calibrated using one embodiment.

FIG. 4 is a perspective view showing a state in which an object to be measured is measured after the origin of absorbance is calibrated.

FIG. 5 is a partially cutaway perspective view showing another embodiment.

FIG. 6 is a perspective view of an apparatus main body showing an embodiment in which an absorbance origin standard device is embedded in the optical measurement apparatus main body.

[Explanation of symbols]

 2 Polyacetal resin plate 4 Black neoprene rubber plate 8 Light transmitter 12 Light receiver

Claims (1)

[Claims] 1. An absorbance origin standard device for use in an optical measuring device for measuring the light absorption characteristics of a sample in a state where an incident point of the measuring light on the light scattering sample and a detection point of the measuring light from the sample are distant from each other. The standard device for origin of absorbance, characterized by comprising a milky white light-scattering plate, the light-transmitting end and the light-receiving end of the light measuring device being in contact with the surface thereof.