JP4723439B2 - Chemical analyzer - Google Patents

Description

  The present invention relates to a chemical analyzer that quantifies a sample by a biochemical reaction, and more particularly to a chemical analyzer that quantifies a sample by measuring absorbance.

  Conventionally, as a chemical analyzer, a chemical analyzer described in US Pat. No. 4,451,433 is known. This chemical analyzer measures the physical properties of a sample during or after the reaction, an automatic sample and reagent supply mechanism for supplying the sample and reagent to the reaction container, an automatic stirring mechanism for stirring the sample and reagent in the reaction container It has a colorimetric measurement unit, an automatic washing mechanism for sucking and discharging the sample for which measurement has been completed, and washing the reaction container, and a control unit for controlling these operations. The processing capacity of chemical analyzers ranges from hundreds of tests per hour to over 9000 tests per hour for large devices.

  The colorimetric measurement unit irradiates the solution to be measured in the reaction container with white light from the light source, and separates the transmitted light with a spectroscopic device. Absorbance is calculated by measuring the light intensity of a specific wavelength among the dispersed light and comparing it with the light intensity of a solution of a reference concentration measured in advance. The chemical component in the solution to be measured is analyzed from the absorbance.

  In a chemical analyzer, a halogen lamp is used as a light source. The halogen lamp is a continuous spectrum light source covering from the visible region to the near infrared region. Moreover, it has the outstanding characteristic that the lifetime of a filament is long by a halogen cycle.

  The rated life is set for the light source lamp. The rated life is defined as the average value of the life of many lamps. Thus, not all lamps reach the end of their service life when the rated life is reached. For example, it may be impossible to turn on the lamp before reaching the rated life.

  Therefore, a recommended replacement period is set for the lamp. The recommended replacement period is set to be shorter than the rated life. That is, the recommended replacement period is set with a margin for the rated life. If this margin is excessive, the lamp replacement frequency is increased, and the running cost is increased. Therefore, in order to reduce the running cost, a recommended replacement period may be set with a small margin for the rated life. However, in this case, it is known that a phenomenon occurs in which the light amount fluctuates in a short time even if the light amount satisfying the specification is secured at the end of the life. Variation in the amount of light leads to variation in measurement accuracy. Therefore, there is a limit to setting a recommended lamp replacement period with a small margin.

U.S. Pat. No. 4,451,433 JP 2001-74553 A Junichi Ozawa Automatic clinical analysis

  As described above, when setting the recommended replacement period of the lamp, it is difficult to set an appropriate margin for the rated life. In addition, setting an appropriate margin does not increase the actual life of the lamp itself.

  An object of the present invention is to provide a chemical analyzer that can extend the life of a light source lamp and ensure measurement accuracy.

  According to the present invention, in order to extend the life of the lamp, the light source driving power is set to a value lower than the rated value. However, the light source driving power is set so that the blank absorbance falls within a predetermined allowable value.

  According to the present invention, the light source driving power supplied to the light source is monitored to diagnose the life of the light source lamp and the failure of the light source lamp. Furthermore, monitoring the absorbance, diagnosing faults of the light source lamp.

  According to the present invention, the life of the light source lamp can be extended and the measurement accuracy can be ensured.

  FIG. 1 shows the configuration of a chemical analyzer according to the present invention. The chemical analyzer of this example includes a control unit 30 and a mechanism unit 40. The control unit 30 includes a control power supply 31, a CPU 32, a memory 33, a storage medium 34, an I / O 35, and an AD converter 36. The mechanism unit 40 includes a light source 41, a light source 42, a multi-wavelength photometer 43, a power meter 44, a sample dispensing mechanism 53, a reagent dispensing mechanism 54, a stirring mechanism 55, a cleaning mechanism 56, and a thermostatic chamber 57. Have.

  The control unit 30 drives each unit of the mechanism unit 40 via the I / O 35. The sample dispensing mechanism 53 dispenses the sample in the sample container 51 into the reaction container 52. The reagent dispensing mechanism 54 injects the reagent into the reaction container 52. The stirring mechanism 55 stirs the mixed solution in the reaction vessel 51 to react the sample and the reagent. The cleaning mechanism 56 cleans the reaction vessel 52. The thermostat 57 holds the reaction system at a constant temperature in order to stabilize the reaction.

  The light from the light source 42 is applied to the mixed solution stored in the reaction vessel 52. The multi-wavelength photometer 43 detects light having a predetermined wavelength out of the light that has passed through the liquid mixture. The AD converter 36 converts the analog signal from the multiwavelength photometer 43 into a digital signal. The control unit 30 calculates the absorbance by comparing the light intensity detected by the multi-wavelength photometer 43 with the light intensity of the reference concentration solution measured in advance. The control unit 30 analyzes the sample based on the absorbance.

  The wattmeter 44 measures the light source driving power, that is, the light source driving current or the light source driving voltage. As a method for measuring the light source driving current, there are a method using a Hall element with the light source 41 as a DC power source, a method using a current transformer with the light source 41 as an AC power, and the like. The method using a Hall element has an advantage that power loss can be suppressed because current is measured without contact. As a method of measuring the light source driving voltage, there is a method of measuring a potential difference generated at both ends of a resistor using a shunt resistor.

  In a preferred example of the present invention, the optical drive current is measured by a method using a Hall element or a method using a current transformer. However, a method for measuring the light source driving voltage is also within the scope of the present invention. Power herein includes both current and voltage.

  The light source power supply 41 supplies power to the light source 42. The light source power supply 41 controls the power supplied to the light source 42 based on a control signal from the control unit 30. The storage medium 34 stores various programs for operating the chemical analyzer. Memory 33 stores the absorbance and the light source driving power in real time. The control power supply 31 is a power supply for the control unit 30. The CPU 32 reads a program stored in the storage medium 34 and controls the operation of the control unit 30.

  The chemical analyzer of this example includes (1) an absorbance calculation process for calculating the absorbance by comparing the light intensity detected by the multiwavelength photometer 43 with the light intensity of a solution of a reference concentration measured in advance, and (2) chemical Lamp life extension mode operation processing for operating the analyzer in the lamp life extension mode, (3) Life determination processing for determining that the light source lamp has reached the end of life and generating a warning to that effect, (4) Failure of the light source lamp It is determined that a failure has occurred, and a failure determination process for generating a warning to that effect is performed.

  Program for these processes is stored in the storage medium 34. The absorbance calculation process has already been described. Other processing will be described in detail below.

  First, the lamp life extension mode operation processing by the chemical analyzer of the present invention will be described in detail. Generally, in order to extend the life of the light source 42, the light source driving power may be reduced. Therefore, in the lamp life extension mode, the light source driving power is set to a value lower than the rated value. However, if the light source driving power is too low, the following problem occurs. First, the first, the halogen cycle no longer function properly. Thereby, there can be a rather short life. Second, the amount of light from the light source is insufficient. Thereby, noise is generated in the output of the photometer, and the measurement accuracy is lowered.

  Therefore, in order to extend the life of each light source lamp, it is necessary to satisfy the following two conditions.

  The first condition is to make the tube wall temperature of the glass sphere higher than a predetermined temperature. In the halogen cycle, components evaporated from the filament return to the filament. Therefore, a function to extend the life of the filament. However, when the tube wall temperature of the glass sphere is lower than a predetermined temperature, components evaporated from the filament adhere to the tube wall, and the halogen cycle does not function. Therefore, the lamp life is shortened. Therefore, in order to perform the halogen cycle smoothly, the tube wall temperature of the glass sphere needs to be higher than a predetermined temperature.

  The second condition is to suppress the noise of the optical system below an allowable value. In general, when the absorbance is large, the photoelectric current detected by the multiwavelength photometer 43 is small. Therefore, the output of the multiwavelength photometer 43 is easily affected by optical and electrical noise. This noise affects the absorbance value and causes measurement errors. In order to reduce the influence of the noise, it is only necessary to increase the light emission amount of the light source and increase the signal amount from the multi-wavelength photometer 43.

  In order to extend the life of the light source 42, the light source driving power may be reduced so as to satisfy these two conditions.

  According to the present invention, to measure the blank absorbance. The absorbance is measured in a state where the reaction vessel 51 is filled with pure water. This is referred to as blank absorbance. Since the absorbance of pure water is essentially zero, the blank absorbance should be zero. If the blank absorbance is not zero, there will be noise. Normally, when a new normal light source is driven by the rated power, the blank absorbance is zero. However, even with a normal light source, reducing the light source driving power causes noise in the output of the photometer. That is, the blank absorbance does not become zero.

  Therefore, according to the present invention, in the lamp life extension mode, the light source driving power is reduced so that the blank absorbance is equal to or less than a practical allowable value. A method for setting the light source driving power will be described below.

  According to the present invention, when the chemical analyzer is in the lamp life extension mode, the multi-wavelength photometer 43 measures the blank absorbance and supplies it to the control unit 30 via the I / O 35. The CPU 32 determines whether or not the blank absorbance is within a predetermined range. When the blank absorbance exceeds a predetermined range, the control unit 30 transmits a command to the light source power supply 41 so as to increase the light source driving power. Light source power supply 41 increases the light source driving power supplied to the light source 42. When the light source driving power is increased, the blank absorbance decreases. Thus, each time the blank absorbance exceeds a predetermined range, the light source driving power is increased. Thereby, the light source driving power is set to a value lower than the rated value so that the blank absorbance falls within a predetermined range. In this example, in the lamp life extension mode, the light source driving power supplied to the light source 42 is smaller than the rated value, so the life of the light source lamp is extended.

  With reference to FIG. 2, the setting process of the light source drive electric power in the chemical analyzer by this invention is demonstrated. When the chemical analyzer is operated in the lamp life extension mode, the light source driving power setting process of this example is performed. In step S <b> 101, the light source power source 41 drives the light source with a preset driving power based on a control signal from the control unit 30. This set power is a value lower than the rated value. In step S102, the reaction vessel 52 is filled with system water and the blank absorbance is measured. In step S103, the control unit 30 determines whether or not the blank absorbance is within a predetermined range. The upper limit of the predetermined range is a practical allowable value of the blank absorbance, and the lower limit of the predetermined range is a value lower than the upper limit by a predetermined value.

  If the blank absorbance is within the predetermined range, the process proceeds to step S105, and if the blank absorbance is not within the predetermined range, the process proceeds to step S104.

  In step S104, the light source driving power is changed. Returning to step S102 again, the blank absorbance is measured, and in step S103, it is determined whether or not the blank absorbance is within a predetermined range. In this way, by repeating Step S104 and Step S125, the light source driving power is set so that the blank absorbance is within a predetermined range. In step S105, the set value of the light source driving power is stored. In step S106, driving the light source by the light source driving power set. The light source driving power obtained by the setting process of the light source driving power is lower than the rated value of the light source lamp, and the blank absorbance is a value that falls within a practical allowable value. Setting processing of the light source driving power of 2 is performed at a predetermined cycle.

  With reference to FIG. 3, the light source driving power setting process and the light source lamp life determination process according to the present invention will be described. The vertical axis | shaft of Fig.3 (a) is a blank light absorbency, and a horizontal axis is time. In FIG. 3B, the vertical axis represents light source driving power, and the horizontal axis represents time. At time t1, it performs setting processing of the light source driving power according to the present invention. Until the time t1, the light source driving power is set to the rated power V0. At this time, the blank absorbance is sufficiently low. The lamp life extension mode is started at time t1. The light source driving power setting process described in FIG. 2 is performed. That is, the light source driving power is set to a value lower than the rated value. The blank absorbance increases. However, the light source driving power is set so that the blank absorbance falls within a predetermined range ΔC. As shown in FIG. 3A, the blank absorbance increases with time even if the light source driving power is constant. Therefore, the light source driving power setting process described with reference to FIG. 2 is performed at a predetermined cycle.

  The rated life L0 is reached at time t2. However, since the light source driving power is set to a value lower than the rated value until the rated life L0, the actual life is not reached even at the rated life L0. Further, the setting process of the light source driving power is repeated, and the light source driving power becomes the rated value at time t3. At the time t4 when a predetermined time has elapsed from the time t3 when the light source driving power becomes the rated value, the lifetime L1 set by the present invention is reached. This life L1 is shorter than the actual life when the light source is actually unusable.

  Thus, according to the present invention, since the life L1 of the light source is sufficiently longer than the rated life L0, the lamp replacement cycle becomes longer and the economy is improved.

  The life determination process will be described. The wattmeter 44 detects the driving power applied to the light source 42 and supplies it to the control unit 30 via the I / O 35. The CPU 32 compares the driving power applied to the light source 42 with the rated value, and determines that the lifetime of the light source lamp is reached when a predetermined time has elapsed since the driving power applied to the light source 42 reached the rated value. To do. When the control unit 30 determines that the light source lamp is at the end of its life, it issues a warning. The warning may be sound generation, lighting of a warning lamp, display on a screen, or the like.

  With reference to FIG. 4, the failure determination process of the light source lamp by the chemical analyzer of the present invention will be described. In the failure determination process, disconnection or continuity abnormality of the filament of the light source 42 is detected. A continuity abnormality such as disconnection due to the life of the light source 42 is detected mainly based on fluctuations in power supplied to the light source 42. The light source driving power detected by the wattmeter 44 is sent to the control unit 30 via the I / O 35. When the controller 30 detects a sudden change in the light source driving power, it determines that the light source lamp has failed.

  Halogen cycle, evaporation of the filament, repeated recombination. However, at the end of life, the filament is thinned and disconnected. As shown in FIG. 4A, when the filament breaks at time t1-t2, the light source driving power instantaneously becomes zero. As shown in FIG. 4B, when the filament is broken halfway at time t3, the light source driving power increases. Therefore, it is possible to detect whether the filament is broken or semi-broken by detecting a sudden change in the light source driving power.

  With reference to FIG. 5, in the chemical analyzer according to the present invention, a method for detecting the disconnection or conduction abnormality of the filament of the light source 42 from the absorbance will be described. FIG. 5A shows the time change of absorbance, and FIG. 5B shows the time change of light source driving power. As shown in FIG. 5A, photometry is performed at a photometric time T of a predetermined period. If the filament of the light source 42 is disconnected during photometry, an increase occurs in the absorbance curve. That is, as shown in FIG. 5 (b), when the filament breaks at time t1-t2, the absorbance increases at time ta-tb as shown in FIG. 5 (a). Further, as shown in FIG. 6, an increase occurs in the reaction curve at the photometric point xc.

  According to the present invention, both the absorbance and the light source driving power are monitored, and when both change simultaneously, it is determined that the lamp of the light source 42 is defective or abnormal.

  In general, there are various causes of fluctuations in absorbance, such as those due to failure of the optical system, those due to the concentration of the sample, and abnormalities in the light source 42. Therefore, it is not possible to accurately detect a failure or abnormality of the light source lamp only by monitoring the absorbance. Therefore, in this example, both absorbance and light source driving power are monitored. In other words, if the light source driving power fluctuates rapidly when the absorbance rapidly increases, it is determined that the cause of the fluctuation in the absorbance is the deterioration of the light source 42.

  In the present invention, the function of extending the lifespan reduces the frequency of replacement of the light source 42, and the function of determining the end of life avoids the risk of reporting illegal data due to the deterioration of the light source 42. it is possible to provide a chemical analysis apparatus having improved reliability of the results.

  According to the present invention, it is possible to display to the user whether or not the light source is stable immediately after the power is turned on. Furthermore, an alarm can be displayed if the user starts an analysis before the light source stabilizes.

  Although the example of the present invention has been described above, the present invention is not limited to the above-described example, and various modifications can be easily made by those skilled in the art within the scope of the invention described in the claims. It will be understood.

It is a figure which shows the example of the structure of the chemical analyzer by this invention. It is a figure which shows the operation | movement of the setting process of the light source drive electric power in the chemical analyzer by this invention. It is a figure explaining the setting process of the light source drive electric power in the chemical analyzer by this invention, and the lifetime determination process of a light source lamp. It is a figure explaining the failure determination process of the light source lamp in the chemical analyzer by this invention. It is a figure explaining the method to detect the disconnection or conduction abnormality of the filament of a light source from the light absorbency in the chemical analyzer by this invention. It is the figure which showed the influence of the reaction curve by the disconnection of the light source in the chemical analyzer by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 30 ... Control part, 31 ... Control power supply, 32 ... CPU, 33 ... Memory, 34 ... Storage medium, 35 ... I / O, 36 ... AD converter, 40 ... Mechanism part, 41 ... Power source for light sources, 42 ... Light source 43 ... multi-wavelength photometer, 44 ... watt meter, 51 ... specimen container, 52 ... reaction vessel, 53 ... sample dispensing mechanism, 54 ... reagent dispensing mechanism, 55 ... stirring mechanism, 56 ... washing mechanism, 57 ... constant temperature Tank

Claims (8)

A light source that irradiates the solution to be measured with light, a power source for light source that supplies driving power to the light source, and a light intensity meter that measures the intensity of the light that has passed through the solution to be measured. In the chemical analyzer for analyzing the components contained in the liquid to be measured by measuring the absorbance from the light intensity obtained by
The light source power source is operated in a lamp life extension mode in which the light source is driven by a light source driving power lower than a rated power ,
In the lamp life extension mode, a blank absorbance obtained with pure water instead of the solution to be measured is measured, and the light source driving power is set so that the blank absorbance is smaller than a predetermined allowable value. A chemical analyzer characterized by 2. The chemical analyzer according to claim 1, wherein in the lamp life extension mode, a light source driving power setting process for setting the light source driving power is performed at a predetermined cycle. In the light source driving power setting process, the blank absorbance is A chemical analyzer, wherein the light source driving power is set to a value lower than a rated power so as to be smaller than a predetermined allowable value. 3. The chemical analyzer according to claim 2, wherein in the light source driving power setting process, the light source driving power is set to a value lower than a rated power so that the blank absorbance falls within a predetermined allowable range. Analysis equipment. 3. The chemical analyzer according to claim 2, wherein in the light source driving power setting process, when the light source driving power is set to a value lower than a rated power, when the blank absorbance exceeds a predetermined allowable value, the lamp life of the light source is reduced. A chemical analyzer characterized by determining that there is. 5. The chemical analyzer according to claim 4, wherein when the light source driving power is set to a value lower than a rated power, the blank absorbance exceeds a predetermined allowable value, and the blank absorbance exceeds a predetermined allowable value. A chemical analyzer that determines that the lamp life of the light source has reached the end of a period. 5. The chemical analyzer according to claim 4, wherein a warning is generated when it is determined that the lamp of the light source is at the end of its life.   The chemical analyzer according to claim 1, wherein a wattmeter for measuring the driving power supplied to the light source is provided, and the driving power of the light source measured by the wattmeter is monitored to thereby detect the lamp of the light source. A chemical analyzer characterized by diagnosing a failure. 8. The chemical analyzer according to claim 7, wherein when the absorbance obtained by the light intensity meter and the driving power of the light source change simultaneously, the lamp of the light source is determined to be faulty. .

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