JP4507373B2 - Urinalysis device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and an apparatus for measuring a urine component such as a urine sugar value which is a glucose concentration in urine collected from animals including humans.
[0002]
[Prior art]
The concentration of urinary components such as urine sugar value reflects part of the health condition. Therefore, a method for easily measuring these is required.
[0003]
Conventionally, a urine test has been performed by immersing a test paper impregnated with a reagent corresponding to each test item such as sugar and protein in urine and observing the color reaction of the test paper with a spectrophotometer or the like. 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.
[0004]
That is, when the test paper is used at home, the amateur is required to set and replace the test paper. This relatively disliked work was thought to have hindered the spread of urinalysis devices to homes.
[0005]
On the other hand, a urine test method that does not require consumables such as test paper has been proposed. In this urinalysis method, focusing on the fact that glucose, which is a typical sugar component in urine, shows the optical rotation, the glucose concentration in urine is determined by the principle of measuring the optical rotation of urine.
[0006]
According to this principle, when light is propagated to a liquid containing an optical rotatory substance, the polarization direction of the light rotates with respect to the concentration of the optical rotatory material. That is, (Equation 1) is satisfied.
[0007]
A = L × α × C (Formula 1)
However, L: Measurement optical path length A: Optical rotation [degree]
α: Specific rotation of the optical rotatory substance C: Substance concentration For example, when light having a wavelength of 589 nm propagates 100 mm in an aqueous glucose solution having a concentration of 100 mg / dl, the polarization direction of the light rotates about 0.05 degree.
[0008]
Next, when N types of optically rotatory substances are contained in the liquid, (Formula 2) is obtained.
[0009]
A = L × (α1 × C1 + α2 × C2 +... + ΑN × CN) (Formula 2)
However, L: Measurement optical path length A: Optical rotation [degree]
αn: Specific rotation of substance n (where n is a natural number of 1 to N) Cn: As apparent from the concentration of substance n (formula 2), for example, in the case of urine, the obtained optical rotation is converted to glucose Depending on the optical rotation angle expressed by, and the optical rotatory substance other than glucose such as protein, the sum of the optical rotation angle is included.
[0010]
Typical optical rotatory substances other than sugar that can be excreted in urine include albumin, which is a kind of protein, and histidine, which is a kind of amino acid. Usually, the excretion amount of albumin into urine is smaller than glucose and is approximately 6 mg / dl or less. In general, the measurement result of the conventional urine sugar value is generally notified by a partition indication symbol such as −, ±, + divided every 50 to 100 mg / dl. In most cases, optical rotation does not deviate from this section display at normal excretion concentrations.
[0011]
[Problems to be solved by the invention]
However, the urinary albumin level of patients with kidney disease may be 100 mg / dl or more, that is, 10 times or more than the normal value. In addition, histidine is usually several mg / dl or less, but may be excreted in the urine in large quantities due to excessive intake of some metabolic diseases and meat. When abnormal excretion of albumin, histidine or the like into the urine, the determination accuracy may be reduced, and the urine sugar value may be displayed in a different manner.
[0012]
As a method for correcting the expression of optical rotation by such an optical rotatory substance other than sugar, the optical rotation angle at a plurality of wavelengths was measured and measured by utilizing the fact that the specific optical rotation differs for each wavelength of light propagating. Establish simultaneous equations corresponding to (Equation 2) for each wavelength and solve them to calculate the concentration of each optically rotatory substance (for example, JP-A-9-138231), or turbidity when heated There has been proposed a heating method (for example, Japanese Patent Laid-Open No. 10-142223) that detects the condition by the degree of light scattering and the degree of attenuation of the amount of transmitted light and subtracts it from the measured optical rotation angle.
[0013]
However, these methods have a problem 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.
[0014]
The present invention solves such a conventional problem, and determines the urinary sugar level determination accuracy by determining abnormal excretion of the optical rotatory substance in urine with a simple configuration and invalidating the determination result. It is an object of the present invention to provide a urinalysis apparatus with improved performance.
[0015]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a total value of optical rotation angles expressed at an average concentration of the optical rotatory substance in the urine when the optical rotation angle direction expressed by the urinary sugar component is a positive value. the calculated optical rotation angle preset as a threshold value, if the optical rotation angle occurring when propagating the urine is the threshold value hereinafter, is provided with a determination mechanism to invalidate the measurement results. By the above determination mechanism, it is possible to improve the determination accuracy of the urine sugar value due to metabolic diseases, fatigue, or temporary abnormal excretion in the urine due to meal contents.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
In order to solve the above-mentioned problem, the invention of claim 1 is based on the optical rotation angle expressed by the average concentration of the optical rotatory substance in the urine when the optical rotation angle direction expressed by the sugar component in urine is a positive value. of preset the optical rotation angle calculated as the threshold as a sum, which optical rotation angle occurring when propagating the urinary when the said threshold value hereinafter, is provided a determination mechanism to invalidate the measurement results It is. By the above determination mechanism, it is possible to improve the determination accuracy of the urine sugar value due to metabolic diseases, fatigue, or temporary abnormal excretion in the urine due to meal contents.
[0018]
Further, the invention of claim 3 is configured such that an optimum determination can be made according to individual differences by changing a predetermined threshold according to individual differences such as sex, age, and physique.
[0019]
In the invention of claim 4, the wavelength of light to be propagated is selected by selecting a wavelength of 900 nm or less that has a relatively large difference in specific rotation between sugar and other optical rotatory substances and that can be applied to a general-purpose laser light source. Thus, the accuracy of determination is further improved, and a configuration that is commercially advantageous can be realized.
[0020]
In the invention of claim 5, since the optical rotation angle is measured by the magnetic zero method, an assembly error hardly occurs.
[0021]
In the invention of claim 6, the optical rotation angle is measured by the optical null method, and the size can be further reduced.
[0022]
According to the seventh aspect of the present invention, when the notification means is provided and the determination result is invalidated, the notification means prompts remeasurement, and the determination accuracy can be further improved.
[0023]
【Example】
Embodiments of the present invention will be described below with reference to FIGS.
[0024]
Example 1
A first embodiment will be described with reference to FIGS. 1 to 3. Reference numeral 1 in FIG. 1 is a control means for controlling the entire urinalysis apparatus, and is composed of a microcomputer and its peripheral circuits. Also, 2 is a notification means for notifying the determination result, for example, a liquid crystal display board or a notification means provided with a switch for instructing the start of inspection by the user, 3 is a light emitting means comprising an optical component such as a laser light source, a light emitting circuit, etc. A urine reservoir for storing urine as a sample, 5 is a light receiving means including optical parts such as a photodiode, a light receiving circuit, and the like, and 6 is an optical rotation angle detecting means.
[0025]
FIG. 3 is a block diagram when the urine test apparatus of FIG. 1 is configured by the magnetic zero method. In FIG. 3, 31 to 33 are examples showing 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 lighting the laser light source 31, and 32 is a component of light from the laser light source 31. Among them, a polarizing filter that allows only a polarized component in a specific direction to pass therethrough, and is here arranged to pass a polarized component in a vertical direction. In FIG. 3, 51 to 54 are examples showing components of the light emitting means 5 surrounded by a broken line, 51 is a photodiode that receives light propagated through urine, and 52 is a light analyzer that passes only a component in a specific polarization direction. It is a filter and is arranged so as to pass only the polarization components in the horizontal direction orthogonal to the polarization filter 32 in the light emitting means 3. Reference numeral 54 denotes a Faraday coil that applies a magnetic field to the light propagated through the urine in the urine reservoir 4 and is formed by, for example, winding an enamel wire around an air core material and enclosing a medium such as water with a glass plate or the like. A light receiving circuit 53 converts a signal output corresponding to the light amount of the photodiode 51 into a voltage value, amplifies the signal output, and inputs the voltage value to the control means 1.
[0026]
Reference numeral 61 denotes a current circuit that changes the intensity of the magnetic field applied by adjusting the amount of current flowing through the Faraday coil 54. In this embodiment, the optical rotation angle is detected by the operation described below.
[0027]
When light is propagated in a medium and a magnetic field is applied in the propagation direction, the polarization direction of the light rotates according to the propagation. This phenomenon is called the optical Faraday effect. This optical Faraday effect is expressed by (Equation 3).
[0028]
a = V × H × L (Formula 3)
here,
a: Polarization direction rotation angle [degree]
V: Verde constant of the medium [degree / A]
H: Magnetic field [A / m]
L: Propagation distance [m]
The magnetic field H of (Equation 3) is proportional to the product (n × I) of the number of turns of the enamel wire of the Faraday coil and the amount of current I that the current circuit 61 passes through the Faraday coil 54. Therefore, when the current amount I is changed and the optical rotation angle a expressed by the optical Faraday effect shown in (Expression 3) is changed, the optical rotation expressed by the optical rotation angle a and the optical rotatory substance in urine shown in (Expression 2). When the angle A is just canceled, an extinction point at which the amount of light received by the light receiving circuit 53 is minimized appears. The optical rotation angle A can be calculated from the current amount I at this extinction point.
[0029]
The optical rotation angle A measured by the above magnetic zero method is the sum of the optical rotation angles expressed by each optical rotatory substance as shown in (Formula 2) when an optical rotatory substance other than sugar exists. ing. Consider a case where only glucose as a sugar and albumin as a protein are present as optical rotatory substances. When the specific rotation of glucose is αg and the rotation angle of albumin is −αa (αa is a positive value), (Expression 2) can be simplified and rewritten as (Expression 4).
[0030]
A = L × (αg × Cg−αa × Ca) (Formula 4)
Therefore, it is considered that the optical rotation angle A in (Equation 4) has a negative value is a case where the albumin concentration Ca is excreted in the urine more than the glucose concentration Cg. The substance is abnormally excreted in the urine, and it can be determined that the case is inappropriate for calculating the urine sugar value.
[0031]
As an example, the urine protein and urine sugar test results when the urine test is actually performed in the population shown in FIG. 2 are shown, and the vertical left end column shows the urine sugar concentration category, and (−) ( Symbols such as ±) are compartment display symbols, numbers such as 100 to 249 are concentration ranges of the compartments in mg / dl units, and the median indicates the concentration at the center of this concentration range as a representative value. The horizontal top column also shows the urine protein concentration category. In the figure, the numbers (%) indicated in the areas A to C surrounded by solid lines or broken lines are the ratio of the number of persons to the total number of persons in this population. Region A is a region of the compartment where the urine sugar value is negative, and regions B and C are regions of the compartment where the urine sugar value is positive. Of these, as an example, section C assumes that the specific rotation αg of sugar and the specific rotation αa of protein are equal, and urine sugar concentration Cg and urine protein concentration Ca are simply set to the median values of each section, If calculation is performed by fitting, the optical rotation angle A is a negative value, and it is a region where a case where it is determined that the urine sugar is not detected and is negative can be considered. However, in this example, 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 partition display.
[0032]
Finally, the operation will be described with reference to FIG. When the urine reservoir 4 is filled with urine and a urine sugar test is started by 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 propagates only the component in the vertical polarization direction. This light propagates in the urine reservoir 4, propagates in the Faraday coil 54, passes through the analysis filter 52, and enters the photodiode 51, and the light quantity at this time is converted into a voltage value by the light receiving circuit 53. To the control means 51. At this time, the light analysis filter 52 allows only the horizontally polarized component expressed by optical rotation by the optical rotatory substance in urine to pass through.
[0033]
In the control means 1, the current flowing through the Faraday coil 51 is changed by the current circuit 61, the extinction point at which the light reception amount in the light receiving circuit 53 is minimized is detected, and this is expressed when the urine is propagated from the current amount at this time. An optical rotation angle A to be calculated 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 optical rotatory substance other than sugar such as protein is abnormally excreted in the urine. And if the result is positive, the sugar concentration Cg is calculated according to (Equation 1), 0 to 100 mg / dl is (-), 100 to 150 mg / dl is (± ), 150-300 mg / dl (+), and is converted into a division display symbol and displayed on the notification means 2.
[0034]
In this embodiment, the method of dividing the threshold for determining abnormal excretion of proteins in urine into positive values or negative values has been described. However, the average excretion concentration of proteins, amino acids, sugars, etc. Applying to (Equation 2), it is also effective to calculate an average optical rotation angle Am expressed by an average urinary component and determine whether this value is larger or smaller than Am using this value as a threshold value.
[0035]
Each of these average excretion concentrations is known to vary depending on individual differences such as gender and age, and the individual threshold information is input using an input key, etc., prior to the examination, and the optimal threshold is used. The determination method is more effective.
[0036]
Further, it is known that the specific rotation α of each optical rotatory 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 approximately equal to each other has been described as a calculation example, but if a laser light source having a wavelength of 900 nm or less that αa is sufficiently larger than αg is used, In addition to being able to apply a general-purpose laser light source, the lower limit of the urine protein concentration for turning the optical rotation angle A to a negative value is lowered, which is effective in improving the determination sensitivity.
[0037]
This magnetic atmosphere method has an effect that an assembly error hardly occurs.
[0038]
(Example 2)
The invention of the second embodiment will be described with reference to FIG. In this embodiment, the configuration for detecting the optical rotation angle A is different from that in the first embodiment, and other operations can be performed in the same manner as in the first embodiment.
[0039]
FIG. 4 is a block diagram when the urine test apparatus of FIG. 1 is configured by the optical null method. Reference numerals 31 to 33 in FIG. 4 are examples showing the components of the light emitting means 3 surrounded by the broken line 3, 31 is a laser light source, 33 is a light emitting circuit for lighting the laser light source 31, and 32 is a component of light from the laser light source 31. Among them, a polarizing filter that allows only a polarized component in a specific direction to pass therethrough, and is here arranged to pass a polarized component in a vertical direction. In FIG. 4, 51, 53, and 55 are examples showing the components of the light emitting means 5 surrounded by a broken line, 51 is a photodiode that receives light propagated through urine, and 55 is a component that passes only a component in a specific polarization direction. The rotation analysis filter is configured such that the analysis filter can be rotated, and is disposed at an initial position such that the polarization direction to pass is orthogonal to the polarization filter 23 in the light emitting means 3. A light receiving circuit 53 converts a signal output corresponding to the light amount of the photodiode 51 into a voltage value, amplifies the signal output, and inputs the voltage value to the control means 1.
[0040]
A motor circuit 62 includes an encoder unit that rotates the rotation analyzing filter 55, detects a rotation angle at that time, and inputs the rotation angle to the control means 1.
[0041]
The operation of FIG. 4 will be described below. When the urine reservoir 4 is filled with urine and a urine test is started according to a user instruction, the control unit 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 propagates only the component in the vertical polarization direction. This light propagates in the urine reservoir 4, passes through the rotational analysis filter 55 and enters the photodiode 51, and the light quantity 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 rotates the rotation analyzing filter 55 by the motor circuit 62, 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 null method of the present embodiment, that is, the rotation angle at this time coincides with the optical rotation angle A expressed when passing through urine.
[0042]
In the present embodiment, the optical rotation angle A is detected by the configuration of the optical zero method that can be miniaturized, and the subsequent operations can be performed in the same manner as in the first embodiment.
[0043]
In the first and second embodiments, when the determination result is invalid, it is possible to notify the notifying means that the re-measurement is promoted, and the time to prompt the re-measurement may be a rest time, a fixed time after meal, an empty stomach, or the like. Thereby, determination accuracy and usability are improved.
[0044]
【The invention's effect】
As is clear from the above embodiment, according to the invention of claim 1, the measurement result is invalidated when the optical rotation angle A generated when propagating through the urine is equal to or less than a preset threshold value or a negative value. A determination mechanism is provided. With this determination function, it is possible to improve the determination result of the urinary sugar level due to metabolic diseases, fatigue, or temporary abnormal excretion in the urine due to meal contents.
[0045]
Further, as in the invention of claim 2, by setting the optical rotation angle calculated as the total value of the optical rotation angles expressed at the average concentration of the optical rotatory substance in the urine as the preset threshold, the urine of the average component Difference can be detected more easily, and the accuracy of determination can be further improved.
[0046]
In addition, as in the third aspect of the invention, by changing a preset threshold value depending on individual differences such as gender, age, and physique, optimal determination can be made according to individual differences.
[0047]
Further, as in the invention of claim 4, by selecting a wavelength of 900 nm or less that can be applied to a general-purpose laser light source as a wavelength of light to propagate, the optical rotation of the optical rotatory substance is relatively large. It is possible to improve the accuracy and realize a configuration that is commercially advantageous.
[0048]
According to the fifth aspect of the present invention, since the optical rotation angle is measured by the magnetic zero method, an assembly error hardly occurs.
[0049]
According to the invention of claim 6, the optical rotation angle is measured by the optical zero method, so that the size can be reduced.
[0050]
According to the seventh aspect of the present invention, the determination accuracy can be improved by providing notification means and prompting re-measurement by the notification means when the determination result is invalidated.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a urine sugar test apparatus according to a first embodiment of the present invention. FIG. 2 is a diagram showing an example of a urine component determination result according to the first embodiment of the present invention. FIG. 4 is a block diagram showing the configuration of the urine sugar test apparatus according to Example 1 of the urine sugar test apparatus according to the magnetic zero method. Explanation】
DESCRIPTION OF SYMBOLS 1 Control means 2 Notification means 3 Light emission means 4 Urine pool part 5 Light receiving means 6 Optical rotation angle detection means

Claims (7)

In the urinalysis apparatus that measures the sugar concentration in the urine by measuring the optical rotation angle that is expressed when light is propagated in the urine, the optical rotation angle direction expressed by the sugar component in the urine is a positive value. when the optical rotation angle calculated as sum of optical rotation angles expressed in average density optical rotation substances in urine previously set as the threshold value, the optical rotation angle is the threshold value hereinafter occurring upon propagating the urine when the urine testing device for invalidating the determination result. The urinalysis apparatus according to claim 1, wherein the preset threshold value is an optical rotation angle calculated as a total value of optical rotation angles expressed at an average concentration of the optical rotatory substance in urine. The urinalysis apparatus according to claim 1 or 2, wherein a preset threshold value is changed according to individual differences such as gender, age, and physique. The urinalysis apparatus according to claim 1, wherein the wavelength of the propagated light is 900 nm or less. The urinalysis apparatus according to claim 1, wherein the optical rotation angle is measured by a magnetic zero method. The urinalysis apparatus according to claim 1, wherein the optical rotation angle is measured by an optical null method. The urinalysis apparatus according to claim 1, wherein a notification unit is provided, and when the determination result is invalid, the notification unit prompts remeasurement.

Images