Patent Application
20130071939
The present invention relates to a technology that can be used in analysis of urine using reagents in, for example, urine testing in medical examinations.
Conventional examples of urine analysis methods include, for instance, the method disclosed in Patent document 1. In the analysis method disclosed in Patent document 1, the concentration of a specific component in urine is determined using test paper that is coated with a reagent. The reagent develops color by reacting with the specific component in the urine, such that the degree of resulting coloration corresponds to the concentration of the specific component. The coloration degree of the reagent is obtained, in the form of an optical numerical value, using an optical instrument. The concentration of the specific component in urine can be then worked out on the basis of that numerical value. In this analysis method, the color tone of urine itself is tested, using the optical instrument, in a state where the urine is not in contact with the reagent. If the urine has color, the coloration state of the reagent may in some instances be affected by the color of the urine. By testing the color of the urine, it becomes accordingly possible to correct the value of the concentration of the specific component when working the concentration out on the basis of the coloration degree of the reagent.
However, the above-described conventional technology has the following drawbacks.
In a case where the urine analysis process is performed using a reagent, the analysis result may in some instances not correspond to actual values, due to the influence of a drug, if any, that is being administered to the subject. A case of testing of bilirubin in urine qualitative testing will be explained next as an example of such an occurrence. The azo coupling method is widely used in bilirubin testing. In the azo coupling method, a diazo reagent reacts with bilirubin under acidic conditions (diazo coupling reaction), and an azo dye is formed as a result. However, reactions in which an azo dye is thus formed are not specific to bilirubin, and may take place if the subject is being administered drugs such as iobenzamic acid, Etodolac, Epalrestat or the like. Therefore, instances, where the reaction of the reagent yields a positive of bilirubin, may actually be instances of false positive. In the above-described conventional technology it is difficult to discriminate accurately between whether the result is actually a false positive or a false negative. The reliability of the testing result was therefore a shortcoming.
Patent document 1: Japanese Patent Application Publication No. H7-35744
It is an problem of the present invention, which was arrived at in the light of the above considerations, to provide a urine analysis method, an analysis device, a program that is used in the urine analysis method, and a storage medium of that program, that allow accurately determining whether a component in urine yields a false positive or a false negative, or that there is a likelihood of such an occurrence, and that allow obtaining highly reliable testing results.
In order to solve the above problem, the present invention relies on the following technical means.
A urine analysis method provided in a first aspect of the present invention includes: a first determination step of, on the basis of a color reaction between a reagent and a specific component in urine, determining a distinction between a positivity and negativity of the specific component; and a step of working out data on light absorption characteristics of the urine itself with respect to light of a predefined wavelength region, this method further including: a second determination step of, when a value of the data on the light absorption characteristics lies within a predefined range and a determination result in the first determination step is either positive or negative as established beforehand, changing the determination result to a false positive or false negative, or determining that there is a likelihood of a false positive or a false negative.
In the second determination step, preferably, a value of the data on the light absorption characteristics is determined to lie within the predefined range when the urine is of a predefined colorless grade or yellow grade.
Preferably, the specific component in the urine is bilirubin, and when the value of the data on the light absorption characteristics lies within the predefined range and the determination in the first determination step has turned out to be bilirubin positive, in the second determination step the positive is changed to a false positive or determination is made that there is a likelihood of a false positive.
In the urine analysis method according to the present invention, preferably, the data on the light absorption characteristics is data denoting light absorption characteristics of the urine with regard to light of a wavelength in the vicinity of 525 nm and of a wavelength in the vicinity of 470 nm.
In the urine analysis method according to the present invention, preferably, it is determined, in the second determination step, that the value of the data on the light absorption characteristics lies within the predefined, range when there hold both relationships in expressions A1<0.08, A2<0.5, where A1 denotes absorbance of the urine with respect to light of wavelength in the vicinity of 525 nm, as absorbance per 10 mm of optical path length, and A2 denotes absorbance of the urine with respect to light of wavelength in the vicinity of 470 nm as absorbance per 10 mm of optical oath length.
In the urine analysis method according to the present invention, preferably, the data on the light absorption characteristics is a calculated value B that is calculated according to expression:
B=(A4−A5)/(A3−A5)
(where A3, A4 and A5 are, respectively, the absorbance of the urine with regard to light of a wavelength in the vicinity of 525 nm, a wavelength in the vicinity of 470 nm and of a wavelength in the vicinity of 635 nm).
In the urine analysis method according to the present invention, preferably, determination is made as to whether a relationship B<5.30 holds or not.
In the urine analysis method according to the present invention, preferably, when the relationship B<5.30 holds, determination is made, in the second determination step, that the value of the data on the light absorption characteristics lies within the predefined range.
In the urine analysis method according to the present invention, preferably, when the relationship B<5.30 does not hold, determination is further made as to whether a relationship A6<0.54 holds or not, and when the relationship A6<0.54 holds, determination is made, in the second determination step, that the value of the data on the light absorption characteristics lies within the predefined range (where A6 denotes absorbance of the urine with respect, to light of wavelength in the vicinity of 470 nm, as absorbance per 10 mm of optical path length).
Preferably, the urine analysis method according to the present invention further includes a step of, when predefined abnormal coloration occurs in the color reaction, detecting that occurrence,
An analysis device provided according to a second aspect of the present invention comprises determination means capable of, on the basis of a color reaction between a reagent and a specific component in urine, performing a first determination of distinguishing between a positivity and negativity of the specific component, and optical measurement means capable of working out data on light absorption characteristics of the urine itself with regard to light of a predefined wavelength region, wherein the determination means is configured so that, when a value of the data on the light absorption characteristics lies within a predefined range and a determination result in the first determination is either positive or negative, as established beforehand, the determination means changes the result of the first determination to a false positive or false negative, or performs a second determination to the effect that there is a likelihood of a false positive or a false negative.
In the second determination in the analysis device according to the present invention, preferably, the value of data on the light absorption characteristics is determined to lie within the predefined range when the urine is of a predefined colorless grade or yellow grade.
In the analysis device according to the present invention, preferably, the determination means is configured so that, in case of determining a distinction between a positivity and negativity of bilirubin as the specific component in the urine, and when the value of the data on the light absorption characteristics lies within the predefined range and a result of the first determination is bilirubin positive, the determination means, in the second determination, changes the positive to a false positive or determines that there is a likelihood of a false positive.
In the analysis device according to the present invention, preferably, the data on the light absorption characteristics is data denoting light absorption characteristics of the urine with regard to light of a wavelength in the vicinity of 525 nm and of a wavelength in the vicinity of 470 nm.
In the analysis device according to the present invention, preferably, determination is made, in the second determination, that the value of data on the light absorption characteristics lies within the predefined range when there hold both relationships in expressions: A1<0.08, A2<0.5, where A1 denotes absorbance of the urine with respect to light of the wavelength in the vicinity of 525 nm and absorbance per 10 mm of optical path length, and A2 denotes absorbance of the urine with respect to light of the wavelength in the vicinity of 470 nm and absorbance per 10 mm of optical path length.
In the analysis device according to the present invention, preferably, the data on the light absorption characteristics is a calculated value B that is calculated according to expression:
B=(A4−A5)/(A3−A5)
(where A3, A4 and A5 are, respectively, the absorbance of the urine with respect to light of a wavelength in the vicinity of 525 nm, a wavelength in the vicinity of 470 nm and of a wavelength in the vicinity of 635 nm.)
The analysis device according to the present invention, preferably, is configured so as to determine whether B<5.30 holds or not.
In the analysis device according to the present invention, preferably, when the relationship B<5.30 holds, determination is made, in the second determination, that the value of the data on the light absorption characteristics lies within the predefined range.
In the analysis device according to the present invention, preferably, when the relationship B<5.30 does not hold, determination is further made as to whether a relationship A6<0.54 holds or not, and when the relationship A6<0.54 holds, determination is made, in the second determination, that, the value of the data on the light absorption characteristics lies within the predefined range (where A6 denotes absorbance of the urine with respect to light of wavelength in the vicinity of 470 nm and absorbance per 10 mm of optical path length).
In the analysis device according to the present invention, preferably, data for identifying the result of the second determination can be outputted using data output means.
The analysis device according to the present invention, preferably, is configured in such a manner that when predefined abnormal coloration occurs in the color reaction, that occurrence is detected.
A program provided by a third aspect of the present invention is a program for causing determination means of an analysis device to perform data processing, the analysis device being provided with: determination means capable of, on the basis of a color reaction between a reagent and a specific component in urine, performing a first determination of distinguishing between a positivity and negativity of the specific component; and optical measurement means capable of working out data on light absorption characteristics of the urine itself with regard to light of a predefined wavelength region, wherein the program comprises data for causing the determination means to execute a second determination of, when a value of the data on the light absorption characteristics lies within a predefined range and a determination result in the first determination step is either positive or negative, as established beforehand, changing the determination result to a false positive or false negative, or determining that there is a likelihood of a false positive or a false negative.
A storage medium provided by a fourth aspect of the present invention is characterized by storing the program provided by the third aspect of the present invention.
Other features and advantages of the present invention will become more apparent from the description of embodiments of the invention set forth below with reference to accompanying drawings.
Preferred embodiments of the present invention are explained below with reference to accompanying drawings.
The transport device 2 is a device for transporting a rack 3, which holds the upright containers 30, along a given pathway. The transport device 2 can be configured in the same way as in known conventional transport devices (for instance, the transport device disclosed in Japanese Patent Application Publication No. 2009-229233), and a detailed explanation of the specific structure involved will be omitted. In the transport device 2, once the rack 3 is brought to a predefined starting-point region Sa, the rack 3 is sequentially transported thereafter along the direction denoted by arrows N1 to N3, to reach ultimately a predefined end-point region Ea. An operation of sampling urine U out of the containers 30 is performed, by a below-described suction nozzle 50, during the process in which the rack 3 is transported in the direction of arrow N2.
As illustrated in
As illustrated in
The dispensing device 5 is capable of performing an operation of sampling urine U out of the containers 30, by way of the suction nozzle 50, and dispenses (by spotting) the sampled urine U onto the specimen 8. The suction nozzle 50 can move vertically and horizontally by virtue of a driving mechanism, not shown. The dispensing device 5 has the function of cleaning the suction nozzle 50, and is provided with a cleaning solution tank 51 that stores a cleaning solution such as distilled water, syringe pumps 52A, 52B, a directional control valve 53 such as a three-way valve, and a flow channel 54 serially formed from the cleaning solution tank 51 up to the suction nozzle 50. The flow channel 54 is configured using an appropriate tube. Negative pressure for suction of the urine U, or positive pressure for discharge of the urine U, can be created inside the suction nozzle 50 through operation of the syringe pumps 52A, 52B. Once discharge of the urine U is over, the cleaning solution in the cleaning solution tank 51 is fed into the suction nozzle 50. The latter can be cleaned thereby. Such a configuration is identical, for instance, to that of the dispensing device disclosed in Japanese Patent Application Publication No. 2000-321270, and will not be explained in detail. In the present embodiment, the optical measurement unit for urine tone testing 7B is provided at a site halfway in the flow channel 54 of the dispensing device 5. This feature will be explained further on.
As illustrated in
To work out the abovementioned light reflectance, a so-called two-wavelength method can be adopted that relies on main light and reference light. For instance, the wavelength of the main light is 565 nm or about 565 nm, and the wavelength of the reflectance is 760 nm or about 760 nm. The reference light helps reduce errors that are caused by, for instance, variability in size and other parameters of the specimens 8. Examples of arithmetic expressions for working out the reflectance are explained further on. The optical measurement unit 7A is configured in such a manner that the latter is capable of appropriately detecting abnormal coloration, if any, that may occur after dispensing of the urine U onto the reagent pads 80. To detect abnormal coloration, the wavelength of main light is for instance 565 nm or about 565 nm, as described above, whereas the wavelength of the reference light is 500 nm or about 500 nm. A scheme for determining abnormal coloration is explained further on.
As
The absorbance of light at a given wavelength (for instance, the abovementioned absorbances A1, A2 and so forth) is worked out from absorbance =log10(I0/I), and I0 and I denote, respectively, the intensity of transmitted light of a solvent (for instance, water) and a solution (for instance, urine) of identical optical path length. The intensity of incident light onto the solution may also be used as I0. Absorbance is proportional to the optical path length. Therefore, absorbance measured at a given optical path length can be converted to absorbance at another optical path length, as described below. As the absorbance there is ordinarily used absorbance per 10 mm of optical path length,
In
The control unit 6 is configured, for instance, using a microcomputer, and comprises a storage unit 60. The control unit 6 corresponds to an example of the determination means in the present invention. In the storage unit 60 there is stored a program and various data items for execution of operation control of the various units of the analysis device AN and execution of various instances of data processing. An example of a specific operation process of the control unit 6 is explained further on.
An example of an analysis method of the urine U that utilizes the analysis device AN is explained next. As a typical example of the method an instance will be explained of testing of positive and negative bilirubin in the urine U. An example of the operation processing procedure of the control unit 6 will be explained with reference to the flowchart illustrated in
Firstly, the transport device 2 is driven, to cause thereby the rack 3 to be transported along the abovementioned given pathway. When the containers 30 reach a predefined position in the course of such transport (S1: YES), the control unit 6 drives the dispensing device 5, and urine U is sampled out of the containers 30 by the suction nozzle 50 (S2). Some of the sampled urine U is infused into the cell 75 of the optical measurement unit for urine tone testing 7B. The control unit 6 causes light to be irradiated, towards the urine U, out of the light source 77 of the optical measurement unit 7B, and the absorbances A1, A2 of the urine U with regard to light of the two wavelength regions is worked out from the amount of transmitted light (S3).
The absorbance A1 is the absorbance of the urine U with regard to light of, for instance, a wavelength of 525 nm or about 525 nm, and denotes absorbance per 10 mm of optical path length. For instance, in a case where the inner diameter (optical path length of the urine region) of the cell 75 illustrated in
The urine U sampled by the suction nozzle 50 is spotted on the reagent pads 80 for bilirubin testing of the specimens 8. Thereafter, light of two wavelengths is sequentially irradiated onto the spotting portions, to measure thereby the reflectance R of light from the spotting portion (S4). In a case where the urine U comprises bilirubin, the diazo reagent on the reagent pads 80 undergoes a color reaction with bilirubin, as explained above. The color reaction corresponds to the bilirubin concentration. The abovementioned reflectance R is worked out, for instance, according to Expression 1.
R=(r1/r2)/(r3/r4) Expression 1
r1: reflected light intensity, at the 565 nm wavelength, of the reagent pad portion for bilirubin detection
r2: reflected light intensity, at the 760 nm wavelength, of the reagent pad portion for bilirubin detection
r3: reflected light intensity, at the 565 nm wavelength, of the reagent pad portion for reference
r4: reflected light intensity, at the 760 nm wavelength, of the reagent pad portion for reference
After the reflectance R is worked out, the control unit 6 performs a first determination of whether bilirubin is either positive or negative, on the basis of the reflectance R and data of a predefined calibration curve stored in the storage unit 60 (S5). In the case of a positive, preferably, a ranking such as positive (1+), (2+), (3+) is established in accordance with the bilirubin concentration.
If in the control unit 6 the result of the first determination is bilirubin positive (S6: YES), a second determination is carried out on whether or not the positive is a false positive or the likelihood thereof is high. In the second determination it is determined whether or not the following Expression 2 and Expression 3 hold for the absorbances A1, A2 of urine U as worked out in step S3 (S7). The numerical values in Expression 2 and Expression 3 are numerical values per 10 mm of optical path length; herein the absorbance can be appropriately modified in accordance with the measured or converted optical path length.
A1<0.08 Expression 2
A2<0.5 Expression 3
If both Expression 2 and Expression 3 hold (S7: YES), the control unit 6 determines a false positive or a high likelihood thereof (S8).
Validation results such as the following are obtained when performing re-testing in accordance with a method (for instance, Ictotest) that is different from the above-described analysis device AN, for multiple urine cases in which the result of the first determination is bilirubin positive. Even if the result of the first determination for urine U of transparent- or yellow-grade color tone is bilirubin positive, re-testing of the foregoing results in a high frequency of negatives (false positives), among which cases of urine U having a predefined transparent- or yellow-grade color tone are all negative (false positives). Expression 2 and Expression 3 are expressions for determining whether the color tone of the urine U is a predefined transparent- or yellow-grade color tone. The color tone of the urine U can be determined to be a predefined transparent- or yellow-grade color tone if both Expression 2 and Expression 3 hold. Therefore, it becomes possible to ultimately determine a bilirubin false positive or a high likelihood thereof, if the result of the first determination is bilirubin positive and Expression 2 and Expression 3 hold. The reliability of the bilirubin testing result by the above-described analysis method can be accordingly increased.
The inventors validated the above-described analysis method by carrying out the latter using an analysis device of structure identical to that of the analysis device AN. Thereupon, it was possible to determine, as a result of a second determination, that a total of 69 samples were false positives from among a total of 85 samples of false positives that yielded bilirubin positive in the first determination and that were deemed to be negative through re-testing by Ictotest. This indicates that the above-described analysis method allows increasing the reliability of the analysis results. This increased reliability of analysis is advantageous in terms of incurring fewer re-tests of urine, and affording improved efficiency in the analysis process.
If, unlike in the above-described instances, the result of the first determination is bilirubin negative (S6: NO), or if Expression 2 and Expression 3 do not hold, even if the result of the first determination is bilirubin positive (S7: NO), then the control unit 6 determines whether or not abnormal coloration has occurred in the reagent pads 80 spotted with the urine U (S10). This determination is performed in accordance with Expression 4 below. In Expression 4, R′ denotes the light reflectance of spotting sites of urine U, and is worked out on the basis of Expression 5.
R′>1.30 Expression 4
R′=(r1/r5)/(r3/r6) Expression 5
r5: reflected light intensity, at the 500 nm wavelength, of the reagent pad portion for bilirubin detection
r6: reflected light intensity, at the 500 nm wavelength, of the reagent pad portion for reference
r1, r3: identical to r1 and r3 of Expression 1.
If Expression 4 holds, the control unit 6 determines that abnormal coloration has occurred (S10: YES). If abnormal coloration occurs, there is a high likelihood that the result of the previous first determination is inaccurate.
Once a series of processes such as the above-described one is over, the control unit 6 causes that determination result to be printed, using the printer 11, on predefined paper (S9). If the second determination is made in addition to the first determination, that fact is also printed using a symbol or the like that for identifying that occurrence. A report 9, for instance such as the one illustrated in
Through the creation of such reports 9, 9A it becomes possible for the testing personnel using the analysis device AN to perceive, quickly and easily, that bilirubin is a false positive or that the likelihood thereof is high. Printing to the effect that bilirubin is a false positive may be performed in forms that differ from those of the above-described reports 9, 9A
Although not illustrated in the drawings, if in step S10 abnormal coloration is determined to have occurred, information denoting that fact is printed for the item on bilirubin in the report 9. As a result, the testing personnel can accurately perceive that the testing results on bilirubin are suspicious, and that re-testing is necessary. Needless to say, the information takes the form of symbols, characters and designs that can be distinguished from information that denotes a false positive.
An explanation follows next, with reference to the flowchart illustrated in
In
When the containers 30 reach a predefined position (S1: YES), the control unit 6 drives the dispensing device 5, and urine U is sampled out of the containers 30 by the suction nozzle 50 (S2). Some of the sampled urine U is infused into the cell 75 of the optical measurement unit for urine tone testing 7B. The control unit 6 causes light to be irradiated, towards the urine U, out of the light source 77 of the optical measurement unit 7B, and absorbances A3, A4, A5 of the urine U with regard to light of the three wavelength regions is worked out from the amount of transmitted light. The control unit 6 calculates a calculated value B on the basis of Expression 6, using the absorbances A3, A4, A5 (S11).
B=(A4−A5)/(A3−A5) Expression 6
The absorbance A3 is the absorbance of the urine U with regard to light of, for instance, a wavelength of 525 nm or about 525 nm. The absorbance A4 is the absorbance of the urine U with regard to light of, for instance, a wavelength of 470 nm or about 470 nm. The absorbance A5 is the absorbance of the urine U with regard to light of, for instance, a wavelength of 635 nm or about 635 nm. In a case where, for instance, the inner diameter of the ceil 75 illustrated in
As pointed out above, the measurement wavelength of the absorbance A3 is, for instance, a wavelength of 525 nm or about 525 nm. As
Next, absorbance A6 is calculated on the basis of the absorbance A4 (S12). The absorbance A6 corresponds to an example of data of light absorption characteristics in the present invention. The absorbance A6 is the absorbance of the urine with respect to light of wavelength 470 nm or about 470 nm, as absorbance per 10 mm of optical path length. The absorbance A6 results from conversion, to absorbance per 10 mm of optical path length, of the absorbance A4 of the urine U with regard to the above-described light of wavelength 470 nm or about 470 nm. If the absorbance A4 has been converted to absorbance per 10 mm of optical path length, the value of the absorbance A4 can be used, as-is, as the absorbance A6. Needless to say, the absorbance A6 may be converted to absorbances per other optical path length, for instance 5 mm, 15 mm and 20 mm. The absorbance A6 may be measured separately from the absorbance A4.
Next, the urine U sampled by the suction nozzle 50 is spotted onto the reagent pads 80 for bilirubin testing of the specimens 8, in the same way as explained for the flowchart of
If the result of the first determination is bilirubin positive (S6: YES), the control unit 6 carries out a second determination of whether or not the positive is a false positive or the likelihood thereof is high. In the second determination it is determined whether Expression 7 holds for the calculated value B worked out in step S11 (S13).
B<5.30 Expression 7
If Expression 7 holds (13: YES), the control unit 6 determines a false positive or a high likelihood thereof (S8).
If Expression 7 does not hold (S13: NO), the control unit 6 performs an additional determination of whether or not Expression 8 holds (S14) with regard to the absorbance A6. The numerical value in Expression 8 is a numerical value per 10 mm of optical path length. The absorbance can be appropriately modified in accordance with the measured or converted optical path length.
A6<0.54 Expression 8
If Expression 8 holds (S14: YES), the control unit 6 determines, in the second determination, that there is a false positive or a high likelihood thereof (S8).
The purpose of Expression 7 is to discriminate precisely false-positive urine from urine for which the result of the first determination is bilirubin positive. As described above, cases of urine having a predefined transparent- or yellow-grade color tone are all negative (false positives). Like Expression 2 and Expression 3, Expression 7 is an expression for determining whether the color tone of the urine U is a predefined transparent- or yellow-grade color tone. The color tone of the urine U can be determined to be a predefined transparent- or yellow-grade color tone if Expression 7 holds. Therefore, it becomes possible to ultimately determine a bilirubin false positive or a high likelihood thereof, if the result of the first determination is bilirubin positive and Expression 7 holds. The reliability of the bilirubin testing result by the above-described analysis method can be increased thereby.
Expression 8 is an expression for additionally determining whether or not there is a false positive, in case that Expression 7 does not hold. If Expression 8 holds, it can be ultimately determined that there is a bilirubin false positive or a high likelihood thereof, even for urine U such that the result of the first determination is bilirubin positive but Expression 7 does not hold. The reliability of the bilirubin testing result by the above-described analysis method can be increased thereby.
The inventors collected urine U of transparent- or yellow-grade color tone, and validated the above-described analysis method by carrying out the latter using an analysis device of structure identical to that of the analysis device AN. Thereupon, through determination using Expression 7, it was possible to determine, as a result of a second determination, that a total of 87 samples were false positives, from among a total of 88 samples of false positives that yielded bilirubin positive as the result of the first determination, and that were deemed to be negative through re-testing by Ictotest. Through additional determination using Expression 8, it was possible to determine, as a result of a second determination, that a total 88 samples were false positives from among the total of 88 samples of the abovementioned false positives.
Determination based on Expression 7 and Expression 8 was performed on 7 samples of transparent- or yellow-grade color tone for which the result of the first determination was bilirubin positive and that yielded positive also according to re-testing by Ictotest. No sample was determined to be a bilirubin false positive or to have a high likelihood thereof.
This indicates that the above-described analysis method allows increasing the reliability of the analysis results. This increased reliability of analysis is advantageous in terms of incurring fewer re-tests of urine, and affording improved efficiency in the analysis process.
If the result of the first determination is bilirubin negative (S6: NO), or if Expression 8 does not hold even if the result of the first determination is bilirubin positive (S14: NO), the control unit 6 determines whether or not abnormal coloration has occurred in the reagent pads 80 spotted with the urine U, in the same way as explained for the flowchart illustrated in
Once the series of processes such as the above-described ones is over, the control unit 6 causes that determination result to be printed, using the printer 11, on predefined paper in the same way as in explained for the flowchart of
The present invention is not limited to the features of the above-described embodiments.
Expressions other than Expression 2, Expression 3, Expression 7 and Expression 8 can be used as the condition for determining whether the bilirubin positive is a false positive. A simple value of light transmittance may be used, instead of absorbance, as the “data on light absorption characteristics of the urine with regard to light of a predefined wavelength region” according to the present invention. Light reflectance can likewise be used, since it also denotes light absorption characteristics. Instances where a first determination result of bilirubin positive is ultimately deemed to be a false positive are fundamentally instances where a color tone of urine is a predefined colorless- or yellow-grade color tone. Therefore, a procedure can be used that involves, for instance, irradiating urine with light of a wide wavelength region, performing a spectral analysis of the transmitted light, determining as a result the color tone of the urine, and, on the basis of that determination result, determining whether or not there is a false positive.
In the above-described embodiments a typical example has been explained relating to bilirubin testing, but the present invention can be used also for testing items other than bilirubin (for instance, urobilinogen or the like). The present invention is not limited to determination of false positives, and can be used for determining also false negatives. The present invention can be used not only in comparatively large analysis devices provided with a transport device for containers, but also in small analysis devices that lack such a transport device.
In the above-described embodiments, the optical measurement unit for urine tone testing 7B provided in the analysis device AN is used for measuring the absorbance of urine, but there may be provided a separate optical measurement unit for measuring the absorbance that is used for determining false positives and false negatives.
In the above-described embodiments, “data on light absorption characteristics of the urine with regard to light of a predefined wavelength region” is acquired using light of wavelength regions in the vicinity of 525 nm, 470 nm and 635 nm, but light of other wavelength regions may be used instead.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2010-126719 | Jun 2010 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2011/061753 | 5/23/2011 | WO | 00 | 11/27/2012 |
