JP6174497B2 - Blood coagulation analyzer - Google Patents

Description

The present invention relates to a blood coagulation analyzer that mixes plasma and a blood coagulation reagent to precipitate fibrin and measures the blood coagulation time using optical means.

  As a device for measuring blood coagulation ability, there is a blood coagulation time measurement device. There are two types of blood coagulation: exogenous ones that coagulate blood leaking outside the blood vessels and ones that intrinsically coagulate blood inside the blood vessels. There are quantitative items such as the prothrombin time (PT) of the test, the activated partial thromboplastin time (APTT) of the endogenous blood coagulation reaction test, and the amount of fibrinogen (Fbg) which is a coagulation reaction substance.

  These items include fibrin that is precipitated by adding a reagent that initiates the coagulation reaction to a sample such as plasma, an optical technique that uses scattered light, transmitted light, etc. This is done by measuring the time when the reaction liquid solidifies by a physical method to acquire the viscosity change. Optical methods have the advantage of being inexpensive and less waste. The physical method has an advantage that measurement can be performed on whole blood in which scatterers such as blood cells exist. Of the optical methods, the transmitted light measurement can be measured stably, and the scattered light measurement is more sensitive to change than the transmitted light measurement.

FIG. 1 is a diagram illustrating an example of coagulation reaction measurement by scattered light measurement. The time when the reagent is mixed is set to 0 seconds, and data is acquired every 0.1 seconds. In the calculation of the coagulation time, the difference (light quantity difference) S between the measurement values before and after the coagulation reaction is detected as a signal, and the time showing the light quantity difference (1/2 S) of that half is taken as the coagulation time (T _coag ). calculate. The PT and APTT items use this clotting time as an indicator of blood clotting ability. In the Fbg item, the Fbg amount is quantified using a calibration curve of the coagulation time and the Fbg amount acquired in advance. These optical methods have a problem that they are more susceptible to scatterers (blood cell walls and fat globules) contained in the blood sample than physical methods.

  FIG. 2 is a diagram showing a problem example when measuring scattered light in the case where a scatterer (blood cell wall or fat globule) exists as a contaminant in the sample. It is assumed that the initial light amount before the coagulation reaction in the case of a sample not mixed with normal impurities is Vs, and increases after the coagulation reaction by a difference in light amount of ΔSs. When a scatterer such as a foreign substance exists in the sample, the base scattered light amount Vs before the coagulation reaction is increased to Vs ′. In this example, when the initial light amount before the coagulation reaction increases, the scattered light amount exceeds the measurement upper limit value of the measuring device during the coagulation reaction, and a range over occurs that exceeds the amplifier output range (0 to 9 V). Although the measurement in such a case can be obtained by lowering the amplifier magnification, there is a problem that the measurement accuracy is lowered at the time of measurement at a low concentration, and therefore the amplifier magnification cannot be lowered. Furthermore, when there are many scatterers, the initial amount of scattered light increases, and the amount of light before the coagulation reaction shown in the figure sometimes exceeds the range from the beginning of measurement as in the reaction curve starting from Vs ″. In other words, the scattered light measurement is highly sensitive because it can capture a large difference in the amount of light before and after the coagulation reaction, but if the sample contains scatterers, the amount of scattered light in the base increases and the measured value is in the range. In some cases, it could not be measured.

  FIG. 3 is a diagram showing an example of transmitted light measurement for a coagulation reaction of a sample containing scatterers such as impurities. In the case of a sample that does not include scatterers such as impurities, the transmitted light amount before the coagulation reaction is Vt, and a light amount difference of ΔSt is obtained by the coagulation reaction, and a time indicating the light amount difference of (1/2) ΔSt. It is obtained as the coagulation time. In the case of a sample containing a scatterer, the measured value is scattered by the scatterer before the reaction, the amount of transmitted light is reduced, and the measured value is reduced to Vt ′. At that time, in the case of transmitted light measurement, there is a tendency that the light amount difference is also affected and decreases, and the transmitted light amount difference after the coagulation reaction is ΔSt ′, and a large light amount difference cannot be obtained. In other words, measurement does not become impossible due to range over or the like, but there arises a problem that the light amount difference of the agglutination reaction is reduced and the accuracy of the coagulation time is deteriorated.

  In the blood coagulation time measuring apparatus, various devices have been made so far in order to avoid the influence of scattering caused by such impurities. Patent Document 1 discloses a technique in which light having a plurality of wavelengths is irradiated, and data having a wavelength that is less affected by scattering or the like among the transmitted light is selected and used for calculating the coagulation time. Patent Document 2 discloses a technique in which scattered light is measured at a plurality of different angles, and data of angles not over-range are selected and used for calculation of the coagulation time.

JP 2007-263912 A WO2011 / 06849

  With the technique described in Patent Document 1, the mechanism is inevitably complicated in order to prepare light of a plurality of wavelengths, and it is difficult to create a simple, highly reliable apparatus with reduced manufacturing costs. The technique described in Patent Document 2 has a drawback that it is likely to be complicated because a large number of light receivers are arranged.

  As described above, conventionally, there has been no apparatus for measuring the coagulation time with high accuracy by suppressing the influence of scattering by impurities with a simple configuration.

  In the present invention, a circuit for shifting the scattered light detection signal at the initial stage of the reaction so as to be within an appropriate range is provided. At that time, if it is not possible to calculate from the scattered light amount data, obtain the scattered light amount expected from the transmitted light amount stored in the data storage unit, and control the offset voltage accordingly, the scattered light amount falls within the measurement range To control.

  A blood coagulation analyzer according to the present invention includes a reaction container for mixing a blood sample such as plasma and a reagent to form a reaction liquid, a light source for irradiating the reaction container with light, and scattered light scattered from the reaction liquid. A scattered light detector for detecting the transmitted light, a transmitted light detector for detecting the transmitted light transmitted through the reaction solution, a scattered light amplifying unit having a function of amplifying the detection signal of the scattered light detector by offsetting, and transmitted light A transmitted light amplifying unit for amplifying the detection signal of the detector, a control unit for controlling the offset of the scattered light amplifying unit, and a memory for storing the output signal of the scattered light amplifying unit and the output signal of the transmitted light amplifying unit in time series And the control unit, when the output voltage of the scattered light amplification unit obtained from the reaction solution before the coagulation reaction is less than or equal to a preset maximum value, so that the output voltage falls within a preset appropriate range Set the offset of the scattered light amplifier to Than is.

  Further, the storage unit holds information indicating the relationship between the output signal of the transmitted light amplification unit and the offset, and when the output voltage of the scattered light amplification unit before the coagulation reaction exceeds a preset maximum value, the control unit Prior to setting the offset of the scattered light amplifier so that the output voltage of the scattered light amplification unit falls within the preset appropriate range, it is determined based on the output signal of the transmitted light amplification unit and the information held in the storage unit The offset is set in the scattered light amplifier.

  Also, after setting the offset, determine the error of the output signal of the scattered light amplification unit stored in time series in the storage unit, and if there is no error, calculate the blood coagulation time based on the output signal of the scattered light amplification unit, If there is, the blood coagulation time is calculated based on the output signal of the transmitted light amplification unit stored in time series in the storage unit.

ADVANTAGE OF THE INVENTION According to this invention, the blood coagulation analyzer which can solve the problem of range over in coagulation time measurement using scattered light, and can implement | achieve a highly sensitive and reproducible analysis can be provided.
Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

The figure which shows the example of the coagulation reaction measurement by a scattered light measurement. Explanatory drawing at the time of the coagulation | solidification reaction curve and scattered light amount increase in a scattered light measurement. Explanatory drawing at the time of the coagulation | solidification reaction curve in transmitted light measurement, and transmitted light amount reduction | decrease. 1 is a schematic view of a blood coagulation time measuring apparatus according to an embodiment of the present invention. Schematic which shows an example of a coagulation time detection part. Flow chart of blood coagulation analysis. The figure which shows the structural example of the amplification part with an offset function. The figure which shows the example of the measurement result which does not carry out offset control at the time of scattered light increase. The figure which shows the measurement result at the time of transmitted light amount reduction | decrease. The figure which shows an example of the relationship of transmitted light amount-offset voltage. The figure which shows the scattered light detector data after performing offset control. The figure which shows the example of a coagulation time measurement result display in an output part.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 4 is a schematic diagram of a blood coagulation time measuring apparatus according to an embodiment of the present invention. This apparatus includes a sample rack holding unit 1, a reagent holding unit 2, a reaction container supply unit 3, a detection unit temperature control unit 4, and a control analysis computer (not shown) as main components.

  The sample rack holding unit 1 holds a plurality of sample racks 11 each containing a blood collection tube 12 containing a blood sample (sample) 15. In the illustrated example, five blood collection tubes 12 are arranged in one sample rack 11. The sample rack 11 is loaded from the loading port 13 and can move sequentially in the sample rack holding unit 1.

  The reagent holding unit 2 includes a reagent bottle 21 that holds a reagent 22 corresponding to a test item, and a reagent dispensing mechanism 23 with a temperature raising function. The reagent dispensing mechanism 23 moves along the linear guide 5 a, sucks the reagent 22 from the reagent bottle 21, and can discharge the reagent whose temperature has been raised by the coagulation time detection unit 41.

  The reaction container supply unit 3 includes a sample dispensing mechanism 31, a sample discharge position 33, a reaction container rack 34 in which a plurality of reaction containers 101 used for measurement are aligned and stocked, and a reaction container that transfers the reaction container 101. A transfer mechanism 35 and a reaction container discarding unit 37 for discarding the used reaction container 101 are provided. The reaction container transfer mechanism 35 moves along the linear guide 5b, grasps the reaction container 101 by sandwiching the upper part of the reaction container from the reaction container rack 34, the sample discharge position 33 in the vicinity of the sample rack holding unit 1, and the detection unit. It can be conveyed to the temperature control unit 4. The reaction vessels 101 in the reaction vessel rack 34 are arranged side by side, and the position information and the usage status of the reaction vessel 101 are stored in the storage unit of the control analysis PC. When the reaction vessel 101 runs out of the reaction vessel rack 34, it is stopped and supplied by the user. The reaction vessel 101 whose coagulation reaction measurement has been completed by the detection unit temperature control unit 4 is grasped by the reaction vessel transfer mechanism 35 in accordance with a command from the control analysis unit and discarded from the reaction vessel discarding unit 37.

  The detection unit temperature control unit 4 includes a plurality of coagulation time detection units 41, and is configured so that the reaction vessel 101 can be set in the coagulation time detection unit. The detection unit temperature adjustment unit 4 is temperature-controlled so that the solution in the reaction vessel 101 becomes constant at 37 ° C.

  The blood coagulation time is measured as follows. First, the reaction container transfer mechanism 35 of the reaction container supply unit 3 transfers one of the reaction containers 101 in the reaction container rack 34 to the sample discharge position 33. Next, the sample dispensing mechanism 31 sucks a predetermined amount of the sample 15 from the sample container 12 positioned at the suction position of the sample rack holding unit 1 and discharges a predetermined amount into the reaction container 101 positioned at the sample discharge position 33. The sample rack 11 that holds the blood collection tube 12 after the sample 15 is sucked and the measurement is completed is sequentially sent to the discharge unit 14. The reaction container transfer mechanism 35 moves the reaction container 101 from which the sample 15 has been discharged at the sample discharge position 33 to the coagulation time detection unit 41 of the detection unit temperature control unit 4. Next, the reagent dispensing mechanism 23 sucks the reagent 22 from the reagent bottle 21 in the reagent holding unit 2, raises the temperature, moves to the detection unit temperature adjustment unit 4, and removes the sample 15 arranged in the coagulation time detection unit 41. The heated reagent 22 is discharged into the reaction vessel 101 provided. At this time, the sample 15 and the reagent 22 are agitated and mixed by the momentum of discharge. The PT item has one type of reagent, but the APTT item and the Fbg item have two types of reagents. In that case, the first reagent is discharged, and after a predetermined time, the next reagent 22 is discharged. The time when the last reagent is discharged is set to 0 second, and the coagulation time detection unit 41 optically measures the reaction liquid in which the sample and the reagent are mixed.

  FIG. 5 is a schematic diagram illustrating an example of the coagulation time detection unit 41. Light is emitted from a light source 102 such as an LED or a laser to a reaction liquid that is a mixed liquid of a sample and a reagent in the reaction vessel 101, and a transmitted light detector 103a that receives light that has passed through the reaction liquid and scattered light in a 90 ° direction. The scattered light detector 103b (photodiode, phototransistor, etc.) that receives the light receives the transmitted light and scattered light from the reaction solution. The installation position of the scattered light detector 103b may be other than the 90 ° direction as long as it is arranged at an angle at which scattered light can be acquired. As the light source 102, an LED having a wavelength of 660 nm was used as a single wavelength light source. The light source 102 may be substantially a single wavelength light source by using a white light source or a number of LED light sources to control the spectrum with a filter and the time for light emission. Further, the transmitted light detector 103a and the scattered light detector 103b may be arranged at different positions, and the transmitted light and scattered light from the reaction solution may be guided to the respective detector positions using an optical fiber. In this embodiment, the transmitted light detector 103a and the scattered light detector 103b are arranged on a horizontal plane including the optical axis of the light source 102, and the direction coinciding with the optical axis is 0 °.

  The light received by the transmitted light detector 103a and the scattered light detector 103b is converted into a photocurrent, amplified by the transmitted light amplification unit 104a and the amplification unit 111 with an offset control function, and transmitted light A / D conversion unit 105a. The optical signal is converted from an analog signal to a digital signal by the optical A / D conversion unit 105b, and is stored in the storage unit 107 in time series as time-dependent light amount data via the control analysis unit 106. Data and conditions stored in the storage unit 107 can be output or input by the input / output unit 108. Analysis parameters used for each item are input by the user via the input / output unit 108 and stored in the storage unit 107. The user uses the input / output unit 108 to select the inspection item requested for each sample. Thereby, the inspection item instruct | indicated with respect to each sample can be analyzed. The transmitted light amount data from the transmitted light detector 103a and the scattered light amount data from the scattered light detector 103b stored / stored in the storage unit 107 are transmitted light amount data based on priorities selected in advance by the user or manufacturer. Alternatively, either one of the scattered light amount data is used for the analysis of the coagulation time. The control analysis unit 106 detects the change amount ΔS of the light amount data, and displays the result on the output unit 108 with the time indicating the light amount difference of (½) ΔS as the coagulation time.

Here, when measuring a sample containing a scatterer, an increase in the amount of scattered light and a decrease in the amount of transmitted light as shown in FIGS. 2 and 3 occur. In this specification, the measurement value will be described using the voltage value output from the amplification unit before the A / D conversion unit. In order to keep the measurement value within the measurement range of the apparatus, the offset voltage ΔV _offset of the amplifying unit 111 with an offset control function is controlled and set in the scattered light measurement. As the offset voltage ΔV _offset , first, an initial voltage Vs before the coagulation reaction after Ta seconds from immediately after the start of measurement is measured, and a difference from a preset appropriate voltage Va is set as ΔV _offset . Here, as an example, Ta = 1.5 (after a second) and Va = 0.1 (V). ΔV _offset is set by an instruction of the control analysis unit 106 in the amplification unit 111 with an offset control function, and affects all measured values after Ta seconds. At this time, if the initial voltage Vs is outside the measurement range, the offset voltage cannot be predicted from the scattered light amount. In that case, the offset voltage is predicted from the transmitted light amount. The maximum value of the measurement range that becomes the boundary is defined as V _max . Here, V _max is set to 7 V as an example. In that case, ΔV _offset is calculated from the initial measurement value Vt of the transmitted light measurement from the transmitted light amount-offset voltage relationship information held in the storage unit.

FIG. 6 shows a flowchart of blood coagulation measurement in the present embodiment. In this embodiment, the scattered light detector 103b is set as the first detector with high priority, and the transmitted light detector 103a is set as the second detector with low priority. The priority may be specified by the manufacturer or freely by the user. Maximum value V _max of the initial measurements, also set to the measured value is considered to lie within a measurement range at the coagulation reaction terminates when starting the measurement from the less measurements. When starting the blood coagulation analyzer, the control analysis unit 106, in step 11, acquires the signal from the scattered light detector 103b after a predetermined time (Ta), checks whether it is not more than the upper limit V _max. If it is less than or equal to the upper limit value V _max , the process proceeds to step 14. If it is equal to or higher than the upper limit value V _max , the process proceeds to step 12 to acquire the measured value Vt of the transmitted light detector 103a, and by referring to information representing the relationship between the transmitted light amount and the offset voltage stored in the storage unit 107. An appropriate offset voltage ΔV _offset is determined. Next, the process proceeds to step 13, where offset control is performed with the determined offset voltage ΔV _offset , and the process returns to step 11.

Thereafter, the offset control is repeatedly performed so that the measured value of the initial scattered light detector 103b is equal to or lower than V _max and falls within the set appropriate voltage Va ± Va ′ (here, 1.0 ± 0.5 V). Specifically, if the result of determination in step 14 is that the signal of the scattered light detector 103b is not within the appropriate voltage Va ± Va ′, the process proceeds to step 15 and an appropriate offset voltage is determined from the signal of the scattered light detector. The process proceeds to step 16 where offset control is performed using the offset voltage. As a result of the above offset control, when the signal of the scattered light detector falls within the appropriate voltage Va ± Va ′, the process proceeds to step 17 to acquire measurement data.

When the offset voltage is predicted and determined from the amount of transmitted light after entering the loop of steps 11 to 13, an error determination is displayed and measurement is not performed unless the signal of the scattered light detector becomes V _max or less. If it does not end within the time Tb, an error determination is displayed and measurement is not performed. In this example, Tb was 3 seconds.

  In step 17, the measurement is continued, and after the measurement is completed, the process proceeds to step 18, where it is checked whether there is a sudden change or large noise in the scattered light measurement data, and an error is determined. If there is no error in the scattered light measurement data, the process proceeds to step 19 to calculate the coagulation time using the scattered light detector data. The calculation result is output to 108 in step 23. On the other hand, if it is determined in step 18 that there is an error in the scattered light measurement data and the scattered light measurement data cannot be used, the process proceeds to step 20. In step 20, it is checked whether there is a sudden change or large noise in the transmitted light measurement data, and an error is determined. If there is no error in the transmitted light measurement data in this determination, the process proceeds to step 21 and the coagulation time is calculated from the transmitted light detector data. If there is an error determination from either measurement result, in step 22, an error is displayed indicating that measurement is impossible, and the result is output.

FIG. 7 is a diagram illustrating a configuration example of the amplifying unit 111 with an offset control function. The light reception signal from the scattered light receiver 103b is amplified at the time of current-voltage conversion by the amplification unit, and then converted into a digital signal by the A / D conversion unit 105b, and is stored as scattered light quantity variation data via the control analysis unit 106. 107 is stored. Here, when the measured value from the amplifying unit exceeds the range, the resistance value of the variable resistance (VR) of the offset unit is changed by the offset voltage ΔV _{offset according} to a command from the control analysis unit 106 to change the base value of the amplifying unit. Reduce the power supply voltage. A power supply of ± 24V was used.

FIG. 8 is a diagram illustrating an example of a measurement result in the Fbg item of a sample including a scatterer as a contaminant. The signal of the scattered light detector 103b is equal to or greater than the maximum value V _max due to the influence of impurities, and exceeds the maximum value of the measurement range 9V.

  FIG. 9 shows a signal of the transmitted light detector 103a as the measurement value of the same specimen. The signal of the transmitted light detector can be measured without exceeding the upper limit (10V) of the measuring instrument because the amount of transmitted light is only reduced when a scatterer is present. However, the difference in the amount of light is not large and noise is large, and it is difficult to ensure the accuracy of the coagulation time.

  FIG. 10 is a diagram illustrating an example of the relationship between the transmitted light amount and the offset voltage. The relationship between the amount of transmitted light and the amount of scattered light can be roughly predicted by the liquid amount ratio between the reagent or the sample and the reagent and the apparatus, and the amount of scattered light is subtracted as an offset voltage. The data of these relationship diagrams is registered in the control analysis unit 106 when the apparatus is shipped. Alternatively, it can be obtained on the apparatus using a predetermined manufacturer-specified solution. This makes it possible to perform calibration so as to be optimal for the situation where the apparatus is placed. These are held for each item. Also, depending on the measurement, the liquid volume of the sample may be changed. However, a correction formula is held so that it can cope with such a change in the liquid volume ratio. In the above description, the measurement value is described as voltage, but the measurement value may be a measurement value (count) after passing through an analog-digital converter instead of a voltage.

As described above, by providing the scattered light amount data with an appropriate offset voltage ΔV _offset predicted from the voltage value Vt before the coagulation reaction of the transmitted light detector 103a, the light amount fluctuation data from the scattered light detector 103b without over-range. Is possible to get.

FIG. 11 is a diagram illustrating scattered light detector data after the offset control is executed. ΔV _offset = 12V was determined when Vt = 2.6V. As a result of controlling 12V as the offset voltage, the initial voltage was 0.09V as shown in FIG. 11, and was within the set appropriate range Va ± Va ′ = 1.0 ± 0.5V. Thus, a coagulation reaction curve was obtained.

  After the measurement is completed, whether there is an error display as described above in the signal of the scattered light detector 103b, whether there has been a sufficient change before and after the coagulation reaction, or whether a large signal drop has occurred during the specified time Check. If there is an error, the coagulation time is calculated using the data of the transmitted light detector. If there is no error, the blood coagulation time is calculated using the data of the scattered light detector 103b. The blood coagulation time is calculated by capturing a change in the light amount (signal), and the absolute amount of the light amount does not directly affect the coagulation time. Therefore, in this embodiment, even if the absolute value of the light amount is different, the blood coagulation time can be treated as the same if the change in the light amount is obtained.

  FIG. 12 is a diagram illustrating a display example of the input / output unit 108. Sample No., examination item, coagulation time, and alarm information are displayed as a set. If a sufficient signal difference cannot be obtained, an error is displayed. If there is a large signal drop, the process proceeds to checking the signal of the transmitted light detector 103a and the blood coagulation time is calculated. In either case, an error is displayed if the clotting time cannot be calculated. The content of the error is displayed in the “content” column. Normally, the coagulation time is calculated by the first priority scattered light measurement, but when the coagulation time is calculated by the second priority transmission light measurement, () is added and displayed. In addition, when the scattered light signal is large and offset control is performed, “!” Or the like is described in the alarm and the content is displayed thereafter. This makes it possible to determine whether or not the measurement is performed with an offset. It can also be determined whether or not the coagulation time is calculated by measuring transmitted light.

  In each of these coagulation time measurement screens, when each inspection item is selected, reaction process data as shown in FIG. 11 can be confirmed. As a result, details can be confirmed visually even during an error / alarm. In the case of Fbg concentration measurement, the coagulation time and the Fbg concentration are calculated from an Fbg calibrator curve prepared separately from the coagulation time.

DESCRIPTION OF SYMBOLS 1 Sample rack holding | maintenance part 2 Reagent holding | maintenance part 3 Reaction container supply part 4 Detection part Temperature control unit 5a, 5b Linear guide 11 Specimen rack 12 Blood collection tube 13 Inlet 15 Sample (sample)
21 Reagent Bottle 22 Reagent 23 Reagent Dispensing Mechanism 31 Sample Dispensing Mechanism 33 Sample Discharge Position 34 Reaction Container Rack 35 Reaction Container Transfer Mechanism 37 Reaction Container Disposal Unit 41 Coagulation Time Detection Unit 101 Reaction Container 102 Light Source 103a Transmitted Light Detector 103b Scattering Photodetector 104a Transmitted light amplifier 105a Transmitted light A / D converter 105b Scattered light A / D converter 106 Control analyzer 107 Storage unit 108 Input / output unit 111 Amplifier with offset control function

Claims (4)

A reaction container for mixing a blood sample and a reagent into a reaction solution;
A light source for irradiating the reaction vessel with light;
A scattered light detector for detecting scattered light scattered from the reaction solution;
A transmitted light detector for detecting transmitted light transmitted through the reaction solution;
A scattered light amplification unit having a function of amplifying the detection signal of the scattered light detector by applying an offset;
A transmitted light amplifying unit for amplifying a detection signal of the transmitted light detector;
A control unit for controlling the offset of the scattered light amplification unit;
A storage unit for storing the output signal of the scattered light amplification unit and the output signal of the transmitted light amplification unit in time series;
When the output voltage of the scattered light amplifying unit obtained from the reaction solution before the coagulation reaction is equal to or less than a preset maximum value, the control unit is configured so that the output voltage falls within a preset appropriate range. A blood coagulation analyzer characterized by setting an offset of an optical amplifier. The blood coagulation analyzer according to claim 1,
Determine the error of the output signal of the scattered light amplification unit stored in time series in the storage unit after the offset setting, and if there is no error, calculate the blood coagulation time based on the output signal of the scattered light amplification unit, When there is an error, the blood coagulation analyzer calculates a blood coagulation time based on an output signal of the transmitted light amplification unit stored in time series in the storage unit. The blood coagulation analyzer according to claim 1,
The storage unit holds information indicating the relationship between the output signal of the transmitted light amplification unit and the offset,
When the output voltage of the scattered light amplification unit before the coagulation reaction exceeds the preset maximum value, the control unit is configured so that the output voltage of the scattered light amplification unit falls within a preset appropriate range. Prior to setting the offset of the scattered light amplifier, the offset determined based on the output signal of the transmitted light amplification unit and the information held in the storage unit is set in the scattered light amplifier. Coagulation analyzer. The blood coagulation analyzer according to claim 3,
Determine the error of the output signal of the scattered light amplification unit stored in time series in the storage unit after the offset setting, and if there is no error, calculate the blood coagulation time based on the output signal of the scattered light amplification unit, When there is an error, the blood coagulation analyzer calculates a blood coagulation time based on an output signal of the transmitted light amplification unit stored in time series in the storage unit.

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