JP2002082047A - Urinalysis device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the accuracy of determining a urine sugar level by detecting the influences of optically active substances other than sugars, without use of additional light sources and optical components. SOLUTION: An optical rotation angle A which appears is calculated by an optical rotation angle detecting means 6 from the amount of light emitted from a light emitting means 1 and then propagating through urine in a urine reservoir portion 4 and received by a light receiving means 5, and a control means 1 compares the optical rotation angle A to a threshold; if the angle is less than the threshold or assumes a negative value, measurements are invalidated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for measuring urinary components such as urinary glucose, which is the concentration of glucose in urine collected from animals including humans.

[0002]

2. Description of the Related Art The concentration of urinary components such as urine sugar level reflects a part of a health condition. Therefore, there is a need for a method of easily measuring these.

Conventionally, urinalysis is performed by immersing a test paper impregnated with a reagent corresponding to each test item such as sugar or protein in urine, and observing the color reaction of the test paper with a spectrophotometer or the like. Was. According to this method, since a new test paper is required for each inspection item, the running cost is high, and there is a limit to automation for labor saving.

That is, when test papers are used at home, the layman is required to set and replace the test papers. It was thought that the relative dislike of this work hindered the spread of urine analyzers to homes.

On the other hand, a urine test method which does not require consumables such as test papers has been proposed. In this urine test method, the glucose concentration in urine is determined based on the principle of measuring the optical rotation of urine, focusing on the fact that glucose, which is a typical sugar component in urine, exhibits optical rotation.

According to this principle, when light is propagated through a liquid containing a rotatory substance, the polarization direction of the light rotates with respect to the concentration of the rotatory substance. That is, (Equation 1) is satisfied.

A = L × α × C (Equation 1) where L: measured optical path length A: optical rotation [degree] α: specific rotation of the optically rotating substance C: substance concentration For example, an aqueous glucose solution having a concentration of 100 mg / dl. When light having a wavelength of 589 nm propagates through the inside by 100 mm, the polarization direction of the light rotates about 0.05 degrees.

Next, when N kinds of optically active substances are contained in the liquid, the following equation (2) is obtained.

A = L × (α1 × C1 + α2 × C2 +... + ΑN × CN) (Equation 2) where L: measured optical path length A: optical rotation [degree] αn: substance n (where n is 1 to Specific rotation of natural number N) Cn: Concentration of substance n As is clear from (Equation 2), for example, in the case of urine,
The obtained optical rotation includes the sum of the optical rotation angle expressed by glucose and the optical rotation angle reported by an optically rotating substance other than glucose such as protein.

Representative optically active substances other than sugars excretable in urine include albumin, a kind of protein, and histidine, a kind of amino acid. Usually, the amount of albumin excreted in urine is even less than that of glucose,
It is about 6 mg / dl or less. In general, the conventional measurement results of urine sugar level are divided into 50 to 100 mg / dl,
In general, the information is notified by a section display symbol such as ± or +. In most cases, the rotation caused by the optically active substance other than the sugar does not shift the section display at a normal excretion concentration.

[0011]

However, the urinary albumin level in patients with renal disease may be 100 mg / dl or more, that is, more than 10 times the normal value. In addition, histidine is usually several mg / dl or less, but may be excreted in a large amount in urine due to some metabolic diseases or excessive intake of meat and the like. At the time of abnormal excretion of such albumin and histidine into the urine, the accuracy of the determination may be reduced and the display of the urine glucose level may be shifted.

As a method of correcting the appearance of optical rotation due to the optical rotation substance other than the sugar, the optical rotation angle at a plurality of wavelengths is measured by utilizing the fact that the specific optical rotation differs for each wavelength of light to be propagated. A simultaneous equation corresponding to (Equation 2) is established for each measured wavelength, and a multi-wavelength equation (for example, JP-A-9-138231) for calculating the concentration of each optically active substance by solving these equations, A heating method (for example, Japanese Patent Application Laid-Open No. H10-142223) has been proposed in which the degree of turbidity is detected based on the degree of light scattering or the amount of attenuation of transmitted light, converted into a protein concentration, and subtracted from the measured optical rotation angle.

However, these methods have a problem in that additional components such as a plurality of light sources and optical components for irradiating a plurality of wavelengths and a heater required for heating are required.

The present invention solves such a conventional problem, and determines the abnormal excretion of the optical rotatory substance into urine with a simple configuration, and invalidates the result of determination to thereby determine the urinary sugar level. It is an object of the present invention to provide a urine test apparatus in which the determination accuracy is improved.

[0015]

In order to solve the above-mentioned problems, the present invention provides a method for measuring the angle of rotation generated when the light is propagated in urine is smaller than a predetermined threshold value or a negative value. It is provided with a determination mechanism for invalidation. With the above-described determination mechanism, it is possible to improve the determination accuracy of a urinary sugar level due to abnormal abnormal excretion in urine due to a metabolic disease, fatigue, or meal contents.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that the angle of rotation generated when propagating in urine is:
A determination mechanism is provided that invalidates the measurement result when the value is equal to or less than a predetermined threshold value or a negative value. With the above-described determination mechanism, it is possible to improve the determination accuracy of a urinary sugar level due to abnormal abnormal excretion in urine due to a metabolic disease, fatigue, or meal contents.

According to a second aspect of the present invention, the accuracy of the determination is further improved by setting, as a preset threshold value, an optical rotation angle calculated as a sum of optical rotation angles that are expressed by the average concentration of the optical rotation substance in urine. It was made.

In the invention according to claim 3, an optimum judgment can be made according to individual differences by changing a predetermined threshold value according to individual differences such as gender, age, and physique.

According to the fourth aspect of the present invention, the difference in specific rotation between sugar and other optically active substances is relatively large as the wavelength of light to be propagated, and a general-purpose laser light source can be used.
By selecting a wavelength of 0 nm or less, the accuracy of determination can be further improved, and a configuration that is commercially advantageous can be realized.

According to the fifth aspect of the present invention, since the optical rotation angle is measured by the magnetic null method, an assembly error hardly occurs.

According to the sixth aspect of the present invention, the optical rotation angle is measured by an optical null method, and the size can be further reduced.

According to a seventh aspect of the present invention, the notifying means is provided, and when the judgment result is invalidated, the notifying means prompts the re-measurement, so that the judgment accuracy can be further improved.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

(Embodiment 1) Embodiment 1 will be described with reference to FIGS. Reference numeral 1 in FIG. 1 denotes control means for controlling the entire urine test apparatus, which is composed of a microcomputer and its peripheral circuits. Reference numeral 2 denotes a notifying unit for notifying a determination result, for example, a liquid crystal display panel or a switch provided by a user for instructing a start of an inspection. A urine reservoir section for storing urine serving as a sample, 5 is a light receiving means including an optical component such as a photodiode or a light receiving circuit, and 6 is a rotation angle detecting means.

FIG. 3 is a block diagram in the case where the urine test apparatus of FIG. 1 is configured by a magnetic null method. 3 to 3 in FIG.
3 is an example showing the components of the light emitting means 3 surrounded by a broken line 3, 31 is a laser light source, 33 is a light emitting circuit for turning on the laser light source 31, 32 is a light component from the laser light source 31 in a specific direction. This is a polarizing filter that allows only a polarized light component to pass, and is arranged so as to pass a polarized light component in the vertical direction. Reference numerals 51 to 54 in FIG. 3 denote examples of components of the light emitting means 5 surrounded by a broken line, 51 denotes a photodiode for receiving light transmitted through urine, and 52 denotes an analysis for passing only a component in a specific polarization direction. Light emitting means 3 which is a filter
Are arranged so as to pass only horizontal polarization components orthogonal to the polarization filter 32 inside. Numeral 54 denotes a Faraday coil for applying a magnetic field to the light propagating in the urine of the urine reservoir 4, which is formed by winding an enamel wire around an air core material and enclosing a medium such as water in a glass plate or the like. Reference numeral 53 denotes a light receiving circuit which converts and amplifies a signal output corresponding to the light amount of the photodiode 51 into a voltage value and inputs the voltage value to the control means 1.

Reference numeral 61 denotes a current circuit for adjusting the amount of current flowing through the Faraday coil 54 to change the intensity of the applied magnetic field.
In the present embodiment, the optical rotation angle is detected by the operation described below.

When light is propagated through a medium and a magnetic field is applied in the direction of propagation, the polarization direction of the light rotates according to the propagation. This phenomenon is called the optical Faraday effect. This optical Faraday effect is represented by (Equation 3).

A = V × H × L (Equation 3) where: a: rotation angle of polarization direction [degree] V: Verdet constant of medium [degree / A] H: magnetic field [A / m] L: propagation distance [M] The magnetic field H in (Equation 3) is proportional to the product (n × I) of the number n of turns of the enameled wire of the Faraday coil and the amount of current I flowing through the Faraday coil 54 by the current circuit 61. Therefore, when the amount of current I is changed to change the angle of rotation a generated by the optical Faraday effect expressed by (Equation 3), the angle of rotation a and the optical rotation expressed by the optically rotating substance in urine shown by (Equation 2) When the angle A is just canceled, the light receiving circuit 5
An extinction point at which the amount of received light of No. 3 becomes minimum appears. The rotation angle A can be calculated from the current amount I at the extinction point.

The optical rotation angle A measured by the magnetic null method described above is as follows when an optical rotation substance other than sugar is present.
As shown in (Equation 2), it is the sum of the optical rotation angles developed by each optical rotation substance. Now, consider a case where only glucose as a sugar and albumin as a protein are present as optical rotatory substances. Assuming that the specific rotation of glucose is αg and the optical rotation angle of albumin−αa (αa is a positive value),
(Equation 2) can be simplified and rewritten as (Equation 4).

A = L × (αg × Cg−αa × Ca) (Equation 4) Therefore, the reason why the optical rotation angle A in (Equation 4) is a negative value is that the albumin concentration Ca is larger than the glucose concentration Cg. This is considered to be the case excreted in urine,
The optical rotatory substance other than sugar is abnormally excreted in urine, which can be determined to be inappropriate for calculating the urinary sugar level.

As an example, the results of urine protein and urine sugar tests are shown when urinalysis is actually performed on the population shown in FIG. 2, and the leftmost column in the vertical column shows the classification of urine sugar concentration. −)
Symbols such as (±) indicate the section display symbols, numbers such as 100 to 249 indicate the concentration range of the section in units of mg / dl, and the median represents the central concentration in this concentration range as a representative value.
The upper right column also shows the classification of urine protein concentration. In the figure, the numbers (%) described in the areas A to C surrounded by the solid line or the broken line are the ratio of the number of persons to the total number of persons in the present population. The area A is an area of a section where the urine sugar value is negative, and the areas B and C are areas of an area where the urine sugar value is positive. Among these, as an example, assuming that the specific rotation αg of the sugar is equal to the specific rotation αa of the protein, the division C is simply expressed by (Equation 4) assuming that the urine sugar concentration Cg and the urine protein concentration Ca are the median of each division. If the calculation is performed by applying the rotation angle, the optical rotation angle A is a negative value, and it is an area where a case where it is determined that urine sugar is not detected and is determined to be negative is considered. However, in the present embodiment, since the optical rotation angle A is a negative value, it is determined that the protein is abnormally excreted in this region C, and the measurement result is discarded. It is possible to reduce the deviation of the section display.

Finally, the operation will be described with reference to FIG. When urine is filled in the urine reservoir 4 and a urine sugar test is started according to a user's instruction, the control means 1
The light emitting circuit 33 turns on the laser light source 31. The light from the laser light source 31 passes through the polarization filter 32, and only the component in the vertical polarization direction propagates. This light propagates through the urine reservoir 4, propagates through the Faraday coil 54, passes through the analysis filter 52, and enters the photodiode 51,
The light quantity at this time is converted into a voltage value by the light receiving circuit 53 and input to the control means 51. At this time, the analysis filter 52 allows only the horizontal polarization component generated by the optical rotation due to the optical rotation substance in the urine to pass.

In the control means 1, the current flowing through the Faraday coil 51 is changed by the current circuit 61, and the light receiving circuit 53 is changed.
Then, the extinction point at which the amount of received light is minimized is detected, and from the current amount at this time, an optical rotation angle A that appears when the urine is propagated is calculated. Next, the control means 1 determines whether the calculated optical rotation angle A is a positive value or a negative value. If the calculated optical rotation angle A is a negative value, the optically active substance other than sugars such as proteins is abnormally excreted in urine. Is reported, the calculation result is discarded, and if the value is a positive value, the sugar concentration Cg is calculated according to (Equation 1), and 0 to 100 mg / d
l is (-), 100-150 mg / dl is (±), 150-3
It is converted to a division display symbol such as 00 mg / dl (+) and displayed on the notification means 2.

In this embodiment, the method of dividing the threshold for judging abnormal excretion of protein or the like into urine into positive and negative values has been described. However, the average protein, amino acid, sugar, etc. It is also effective to apply the excretion concentration to (Equation 2), calculate the average rotation angle Am that appears in the average urine component, and use this value as a threshold to determine whether it is larger or smaller than Am.

It is also known that these average excretion concentrations differ depending on individual differences such as gender and age. Prior to the examination, the individual excretion concentration is input using an input key or the like to obtain an optimal threshold value. Is more effective.

Further, it is known that the specific optical rotation α of each optically rotating substance has different wavelength characteristics depending on the wavelength. In the description of FIG. 2, the case where the specific rotation αg of the sugar and the specific rotation αa of the protein are almost equal has been described as a calculation example.
If a laser light source having a wavelength of 900 nm or less where αa is sufficiently larger than αg can be used, a general-purpose laser light source can be applied, and the lower limit of the urine protein concentration for the optical rotation angle A to be a negative value can be reduced. This is effective in improving the determination sensitivity.

The magnetic atmosphere method has an effect that an assembly error hardly occurs.

(Embodiment 2) The invention of Embodiment 2 will be described with reference to FIG. This embodiment is different from the first embodiment in the configuration for detecting the optical rotation angle A, and other operations can be performed in the same manner as in the first embodiment.

FIG. 4 is a block diagram in the case where the urine test apparatus of FIG. 1 is configured by the optical null method. 31 of FIG.
3 is an example showing the components of the light emitting means 3 surrounded by a broken line 3, 31 is a laser light source, 33 is a light emitting circuit for turning on the laser light source 31, 32 is a light component from the laser light source 31 in a specific direction. This is a polarizing filter that allows only a polarized light component to pass, and is arranged so as to pass a polarized light component in the vertical direction. In FIG. 4, reference numerals 51, 53, and 55 denote examples of components of the light-emitting means 5 surrounded by a broken line. Reference numeral 51 denotes a photodiode that receives light transmitted through urine, and 55 denotes only a component in a specific polarization direction. This is a rotation analysis filter configured to rotate the analysis filter, and is disposed at an initial position such that the polarization direction to be passed is orthogonal to the polarization filter 23 in the light emitting means 3. Reference numeral 53 denotes a light receiving circuit which converts and amplifies a signal output corresponding to the light amount of the photodiode 51 into a voltage value and inputs the voltage value to the control means 1.

Reference numeral 62 denotes a motor circuit having an encoder section for rotating the rotation detection filter 55, detecting a rotation angle at that time, and inputting the rotation angle to the control means 1.

The operation of FIG. 4 will be described below. When urine is filled in the urine reservoir 4 and a urine test is started according to a user's instruction, the control means 1 turns on the laser light source 31 by the light emitting circuit 33. The light from the laser light source 31 passes through the polarization filter 32, and only the component in the vertical polarization direction propagates. This light propagates through the urine collecting section 4 and passes through the rotation detection filter 55 and enters the photodiode 51. The light amount at this time is converted into a voltage value by the light receiving circuit 53 and input to the control means 1. The control means 1 causes the motor circuit 62 to rotate the rotation detection filter 55, detects the extinction point at which the amount of light received by the light receiving circuit 53 is minimum, and inputs the rotation angle at this time from the motor circuit 62. In the configuration of the optical nulling method of this embodiment, that is, the rotation angle at this time coincides with the optical rotation angle A developed when passing through urine.

In the present embodiment, the optical rotation angle A is detected by the configuration of the optical null method capable of reducing the size, and the subsequent operation can be performed in the same manner as in the first embodiment. .

In the first and second embodiments, when the determination result is invalidated, the notification means is notified to prompt re-measurement, and the timing for prompting the re-measurement is set at rest, a fixed time after a meal, or on an empty stomach. Is also good. Thereby, the determination accuracy and the usability are improved.

[0044]

As is apparent from the above embodiment, according to the first aspect of the present invention, when the optical rotation angle A generated when propagating in urine is equal to or less than a predetermined threshold value or a negative value,
The measurement result is provided with an invalidity judgment mechanism. With this determination function, it is possible to improve the determination result of the urinary sugar level due to metabolic disease or temporary abnormal excretion in urine due to fatigue or meal contents.

Further, as described in the second aspect of the present invention, by setting a predetermined threshold value as an optical rotation angle calculated as a sum of optical rotation angles expressed at an average concentration of the optical rotation substance in urine, an average rotation angle can be obtained. The difference between the component and urine can be easily detected, and the accuracy of the determination can be further improved.

Further, by changing the threshold value set in advance according to individual differences such as gender, age, and physique as in the third aspect of the invention, it is possible to make an optimal determination according to individual differences.

Further, as in the invention of claim 4, as the wavelength of the light to be propagated, a wavelength of 900 nm or less to which a general-purpose laser light source can be applied while the optical rotation of the optically rotating substance is relatively large is selected. It is possible to improve the accuracy of the threshold value determination and realize a commercially advantageous configuration.

According to the fifth aspect of the present invention, since the optical rotation angle is measured by the magnetic null method, an assembly error hardly occurs.

According to the sixth aspect of the present invention, since the optical rotation angle is measured by the optical null method, the size can be reduced.

According to the seventh aspect of the present invention, the notifying means is provided, and when the judgment result is invalidated, the notifying means prompts the re-measurement, so that the judgment accuracy can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a urine sugar testing device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of a urine component determination result according to the first embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of the urine sugar testing apparatus according to the first embodiment of the present invention using a magnetic null method.

FIG. 4 is a block diagram showing a configuration of the urine sugar test apparatus according to the second embodiment of the present invention using an optical null method.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 control means 2 notification means 3 light emitting means 4 urine reservoir 5 light receiving means 6 optical rotation angle detecting means

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Miki Ueda 1006 Kazuma Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd. (72) Inventor Toshiaki Miyachi 1006 Odaka Kadoma Kadoma, Osaka Pref. Terms (reference) 2G045 AA16 CB03 DA31 FA11 FA29 GC30 2G059 AA01 BB13 CC16 EE01 EE05 GG01 GG04 HH01 JJ19 KK01 MM03 MM05 PP04

Claims (7)

[Claims] 1. A urine test apparatus for measuring a sugar concentration in urine by measuring an optical rotation angle generated when light is propagated in urine, wherein the optical rotation angle direction expressed by a sugar component in the urine is provided. A urine test apparatus that invalidates the determination result when the optical rotation angle generated when the light propagates in the urine is a negative value equal to or less than a predetermined threshold value when is a positive value. 2. The urine test apparatus according to claim 1, wherein the preset threshold value is an optical rotation angle calculated as a sum of optical rotation angles that are expressed at an average concentration of the optical rotation substance in urine. 3. The urine test apparatus according to claim 1, wherein a preset threshold value is changed according to individual differences such as gender, age, and physique. 4. The urine test apparatus according to claim 1, wherein the wavelength of the light to be propagated is a wavelength of 900 nm or less. 5. The urine test apparatus according to claim 1, wherein the optical rotation angle is measured by a magnetic null method. 6. The urine test apparatus according to claim 1, wherein the optical rotation angle is measured by an optical null method. 7. The urine test apparatus according to claim 1, further comprising a notifying unit, wherein when the determination result is invalidated, the notifying unit prompts a re-measurement.