Automatic analysis device

Abstract

The purpose of the present invention is to provide an automatic analysis device in which flicker is suppressed and that conforms to standards of medical electrical equipment. In order to achieve the above, the present invention is an automatic analysis device comprising a thermostatic tank for storing thermostatic water that maintains a liquid mixture of a specimen and a reagent in a reaction container at a prescribed temperature, a heater for heating the thermostatic water, and a control unit for controlling the heater, wherein when a (ms) represents the pulse width of an ON signal, which is a control signal for switching the heater ON, and b (ms) represents the pulse width of an OFF signal, which is a control signal for switching the heater OFF, a and b have fixed lengths and the relationship a < b is satisfied.

Description

Technical Field

[0001] The present invention relates to an automatic analyzer.

Background Art

[0002] In an automatic analyzer that performs qualitative and quantitative analysis of a predetermined component contained in a sample (specimen) such as blood, in order to ensure the reproducibility of the analysis, it is necessary to react the sample and the reagent under the same conditions, and it is common to provide a thermostat that keeps the reaction vessel for reacting the sample and the reagent at a constant temperature. The thermostat stores constant-temperature water, and the temperature of the constant-temperature water is maintained by repeatedly turning on and off a heater for heating the constant-temperature water.

[0003] However, the on / off operation of the heater gives a relatively large fluctuation in power consumption to the entire automatic analyzer. Therefore, a method for leveling the power consumption in the automatic analyzer has been considered. For example, Patent Document 1 discloses a technique for reducing the maximum value of power consumption by preventing the heater and the refrigerator of the automatic analyzer from being turned on at overlapping timings.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Regarding "IEC60601-1-2:2014," a standard for medical electrical equipment including automated analyzers, compliance with limitations on voltage fluctuations and flicker (basic standards: IEC61000-3-3, IEC61000-4-15) has become increasingly required in recent years. While the technology disclosed in Patent Document 1 is effective in suppressing the magnitude of voltage fluctuations that occur in automated analyzers, depending on the frequency of power consumption fluctuations caused by the ON / OFF switching of the heater (specifically, when power consumption fluctuations are around 8-10 Hz), it may not be able to comply with the above standard.

[0006] The objective of the present invention is to provide an automated analysis device that suppresses flicker and conforms to the standards for medical electrical equipment. [Means for solving the problem]

[0007] To achieve the above objective, the present invention provides an automatic analyzer comprising: a constant temperature bath for storing constant temperature water that maintains a mixture of a sample and a reagent in a reaction vessel at a predetermined temperature; a heater for heating the constant temperature water; and a control unit for controlling the heater. The system further includes a relay board that switches the power supply and de-power supply between the AC power supply and the heater, and the relay board has a zero-crossing function that switches the supply of AC voltage from the AC power supply at the timing of the zero-crossing point. If the pulse width of the ON signal, which is a control signal to turn on the heater, is a (ms), and the pulse width of the OFF signal, which is a control signal to turn off the heater, is b (ms), then a and b are of fixed length, and a <bと Furthermore, if the frequency of the AC power supply is S (Hz), then a < 500 / S, and 500 / S <bと do. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an automated analysis device that suppresses flicker and conforms to the standards for medical electrical equipment. [Brief explanation of the drawing]

[0009] [Figure 1] A perspective view showing the schematic configuration of the automated analyzer according to Example 1. [Figure 2] Block diagram of the temperature control system [Figure 3] This diagram shows the output timing of the control signal that turns the heater ON / OFF. [Figure 4]This diagram shows the relationship between the control signal for the heater and the actual ON / OFF state of the heater. [Figure 5] As a comparative example 1, this figure shows the actual ON / OFF state of the heater when the pulse width of the ON signal is 10 ms or more. [Figure 6] As a comparative example 2, the diagram shows the actual ON / OFF state of the heater when the pulse width of the OFF signal is 10 mm or less. [Figure 7] A perspective view showing a schematic configuration of the automated analyzer according to Example 2. [Figure 8] Schematic diagram of the temperature control system in Example 2 [Figure 9] In Example 2, the diagram shows the output timing of the control signals that turn the heater and load ON / OFF. [Figure 10] In Example 3, the diagram shows the output timing of the control signals that turn the heater and the cooler ON / OFF. [Figure 11] In Example 4, the diagram shows the output timing of the control signals that turn the heater and the cooler ON / OFF. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. [Examples]

[0011] First, the basic configuration of the automated analyzer will be explained using Figure 1. Figure 1 is a perspective view showing a schematic configuration of the automated analyzer according to Example 1. The automated analyzer 100 is a device for measuring a liquid mixture of a sample such as a patient's blood or urine and a reagent. As shown in Figure 1, it mainly comprises a sample transport mechanism 104, a sample dispensing mechanism 101, a reagent dispensing mechanism 106, a constant temperature bath 111, a heater 114, a cooler 109, a stirring mechanism 113, a measuring unit (light source 107, spectrophotometer 110, etc.), a cleaning mechanism 105, and a controller 102.

[0012] The sample transport mechanism 104 transports the rack 103, on which sample containers such as blood collection tubes containing the sample to be analyzed are mounted, to the sample dispensing (aspiration) position. The sample dispensing mechanism 101 dispenses the sample from the sample container into the reaction vessel 112 at the sample dispensing position. The reagent dispensing mechanism 106 dispenses the reagent from the reagent container 108 (reagent bottle) into the reaction vessel 112 at the reagent dispensing position. The constant temperature bath 111 stores constant temperature water and immerses the reaction vessel 112 mounted on the reaction disk 116 in the constant temperature water. The reaction vessel 112 contains a mixture of sample and reagent, and the temperature of this mixture is controlled to maintain a target temperature by the constant temperature water in the constant temperature bath 111, thereby promoting the chemical reaction between the sample and reagent. The heater 114 heats the constant temperature water in the constant temperature bath 111. The refrigerator 109 has a rotatable reagent disc inside and cools the reagents contained in the reagent containers 108 placed on the reagent disc. The stirring mechanism 113 stirs the sample and reagents dispensed into the reaction vessel 112. The measurement unit includes a light source 107 and a spectrophotometer 110 and measures the absorbance of the mixed liquid (reaction solution) in the reaction vessel 112. The washing mechanism 105 washes the reaction vessel by discharging and aspirating washing solution at the reaction vessel 112 in the washing position. The controller 102 controls the operation of each mechanism and performs analytical processing based on the measurement results from the measurement unit.

[0013] The analysis of samples using an automated analyzer is generally performed in the following order. First, a rack 103 loaded with sample containers is placed into the loading area, and the rack 103 is then moved to the sample dispensing (aspiration) position by the sample transport mechanism 104. The samples in the sample containers loaded on the rack 103, upon arrival at the sample dispensing (aspiration) position, are dispensed into the reaction vessel 112 of the constant temperature bath 111 (reaction disk 116) by the sample dispensing mechanism 101. The sample dispensing is performed the necessary number of times depending on the analysis items requested for the sample.

[0014] Next, the reagent dispensing mechanism 106 sucks the reagent for analysis from the reagent container 108 in the cold storage 109 and discharges the reagent to the reaction container 112 into which the sample has been previously dispensed. Subsequently, the stirring mechanism 113 stirs the mixed solution of the sample and the reagent in the reaction container 112. Thereafter, the light source 107 generates light, and the spectrophotometer 110 measures the light intensity of the transmitted light when the generated light passes through the reaction container 112 containing the reaction solution after stirring. Information regarding the light intensity measured by the spectrophotometer 110 is transmitted to the controller 102. Then, the controller 102 performs calculations using the received information, determines the concentration of a predetermined component in the sample, and causes the result to be displayed on the display unit or stored in the storage unit.

[0015] Hereinafter, a control method for the heater 114 that heats the constant temperature water in the constant temperature bath 111 will be specifically described.

[0016] FIG. 2 is a block diagram of the temperature control system. As shown in FIG. 2, the constant temperature bath 111 is provided with a temperature sensor 117 such as a thermistor, and the temperature of the constant temperature water is fed back to the control unit 118 (temperature control board). Based on the measurement value of the temperature sensor 117, the control unit 118 outputs a control signal for switching the ON / OFF of the heater 114 at a predetermined timing. The relay board 119 switches the energization and non-energization between the AC power supply 120 (commercial power supply) and the heater 114 based on the control signal transmitted by the control unit 118. That is, the control unit 118 can keep the constant temperature water in the constant temperature bath 111 at a predetermined temperature, for example, 37.0 ± 0.1°C, by appropriately switching the ON and OFF of the heater 114.

[0017] FIG. 3 is a diagram showing the output timing of a control signal for turning on / off the heater. When the automatic analyzer is started, for the purpose of quickly heating the constant-temperature water to a predetermined temperature, the control unit 118 outputs only a control signal for turning on the heater 114 (hereinafter simply referred to as an "ON signal") and keeps the heater 114 continuously in the ON state. After the temperature of the constant-temperature water has risen to the predetermined temperature, the control unit 118 changes the number of pulses of the ON signal included within a certain period according to the degree of temperature drop of the constant-temperature water, thereby maintaining the temperature of the constant-temperature water.

[0018] As shown in FIG. 3, during the temperature maintenance operation of the constant-temperature water, after outputting an ON signal once, the control unit 118 does not continuously output an ON signal but outputs a control signal for turning off the heater 114 (hereinafter simply referred to as an "OFF signal"). However, even if the ON signal is not continuously output, if the pulse width of the ON signal is long, there is a possibility that the ON state of the heater 114 will continue. If the ON state of the heater 114 continues, the switching cycle of the ON / OFF state of the heater 114 will become long, and when converted to a frequency, it may drop to around 8 Hz to 10 Hz. As a result, the fluctuation of power consumption in the heater 114 becomes a factor causing flicker, and it may not be possible to comply with the items regarding voltage fluctuation and flicker restrictions (basic standards: IEC61000-3-3, IEC61000-4-15) in the standard "IEC60601-1-2:2014" for medical electrical equipment (hereinafter simply referred to as the "IEC standard"). Therefore, in this embodiment, when the pulse width of the ON signal is a (ms) and the pulse width of the OFF signal is b (ms), a and b are fixed lengths and a < b (in the example of FIG. 3, a = 9, b = 12).

[0019] Figure 4 shows the relationship between the control signal for the heater and the actual ON / OFF state of the heater. In this embodiment, the relay board 119 has a zero-cross function that switches the supply of AC voltage from the AC power supply 120 at the timing of the zero-cross point. Therefore, when the AC power supply 120 is 50Hz, the time from one zero-cross point to the next is 10ms, so the ON / OFF state of the heater 114 can be switched at a minimum of every 10ms. If the ON / OFF state of the heater 114 is switched every 10ms, the period from the first ON state to the second ON state becomes 20ms, which corresponds to a frequency of around 50Hz, thus moving away from the 8Hz to 10Hz range. In other words, it is desirable to set the pulse width of the control signal for the heater 114 to around 10ms.

[0020] Next, we will explain, using Comparative Examples 1 and 2, why, when the AC power supply 120 is 50Hz, the pulse width of the ON signal should be shorter than 10ms and the pulse width of the OFF signal should be longer than 10ms.

[0021] Figure 5 shows the actual ON / OFF state of the heater when the pulse width of the ON signal is 10 ms or more, as comparative example 1. As shown in Figure 5, when the pulse width of the ON signal is made longer than 10 ms, there may be two phases of the zero-crossing point of the AC power supply 120 between the rising and falling edges of the ON signal. In such cases, even if the control signal instructs ON→OFF, the actual ON / OFF state of the heater 114 becomes ON→ON. If the ON state of the heater 114 is continuous, the switching cycle of the ON / OFF state of the heater 114 becomes longer, and the frequency approaches 8 Hz to 10 Hz, which may cause it to fail to comply with the IEC standard. Therefore, it is desirable to make the pulse width of the ON signal shorter than 10 ms.

[0022] FIG. 6 is a diagram showing the actual ON / OFF state of the heater when the pulse width of the OFF signal is 10 mm or less as Comparative Example 2. As shown in FIG. 6, when the pulse width of the OFF signal is shortened to 10 mm or less, the phase of the zero-crossing point of the AC power supply 120 may not be included between the rise and fall of the OFF signal. In such a case, even if the control signal instructs OFF→ON, the actual ON / OFF state of the heater 114 becomes ON→ON. When the ON state of the heater 114 continues, the switching cycle of the ON / OFF state of the heater 114 becomes longer, and when converted to a frequency, it approaches 8 Hz to 10 Hz, which may make it impossible to comply with the IEC standard. Therefore, it is desirable that the pulse width of the OFF signal be longer than 10 ms.

[0023] The above description is based on the assumption that the AC power supply is 50 Hz, but the same concept can be applied when the AC power supply is 60 Hz. That is, when the AC power supply is 60 Hz, since the time from zero-crossing point to zero-crossing point is 8.3 ms, it is desirable that the pulse width of the ON signal be shorter than 8.3 ms and the pulse width of the OFF signal be longer than 8.3 ms. Generalizing these, when the pulse width of the ON signal is a (ms), the pulse width of the OFF signal is b (ms), and the frequency of the AC power supply is S (Hz), it can be said that it is desirable that a < 500 / S and 500 / S < b.

[0024] Here, the non-continuity of the ON state of the heater 114 also leads to suppression of excessive rise in the constant water temperature. On the other hand, when the pulse width of the OFF signal is increased, two phases of the zero-crossing point of the AC power supply 120 may be included between the rise and fall of the OFF signal. In that case, the actual heater will be in a continuous OFF state. However, even when a continuous OFF signal is output, it is desirable that the sum of the total output time of the continuous OFF signal and the output time of the ON signal be less than 100 ms. As a result, the cycle from the first ON state to the second ON state becomes less than 100 ms, and when converted to a frequency, it becomes greater than 10 Hz, making it possible to conform the power consumption variation in the heater 114 to the IEC standard.

[0025] In the automated analyzer of Example 1, the pulse width of the ON signal was set to 9 ms and the pulse width of the OFF signal to 12 ms, and a flicker test based on the IEC standard was actually performed. As a result, the measured value Plt (long-term flicker value) was 0.583, which is smaller than the limit value of Plt of 0.65 in the IEC standard, confirming that it conforms to the IEC standard. [Examples]

[0026] While Example 1 suppressed flicker in terms of frequency among the fluctuations in power consumption, Example 2 suppressed flicker in terms of magnitude (amount of fluctuation) among the fluctuations in power consumption.

[0027] Figure 7 is a perspective view showing a schematic configuration of the automated analyzer according to Example 2. As shown in Figure 7, the automated analyzer of Example 2 differs from the automated analyzer of Example 1 shown in Figure 1 in that it further includes a power-consuming load 115. An example of the load 115 is a resistor that converts electricity into heat.

[0028] Figure 8 is a schematic diagram of the temperature control system of Embodiment 2. As shown in Figure 8, the heater 114 and the load 115 are controlled by a common control unit 118. When the heater 114 is switched to the OFF state, the control unit 118 outputs a control signal to the load 115 so that it turns ON after a certain time constant. Note that the load 115 is located in a different place from the constant temperature bath 111, as shown in Figure 7, so even when the load 115 is turned ON, it does not affect the temperature of the constant temperature water.

[0029] Figure 9 shows the output timing of the control signals that turn the heater and load ON / OFF in Example 2. As shown in Figure 9, in Example 2, when the heater 114 is ON, the load 115 is OFF, and when the heater 114 is OFF, the load 115 is ON. By controlling the ON / OFF timing of the heater 114 and the load 115 to be in opposite phases in this way, fluctuations in the overall power consumption of the automatic analyzer 100 are suppressed.

[0030] Furthermore, when a flicker test based on IEC standards was actually performed using the automated analyzer in Example 2, the Plt value was 0.95. Since the Plt value was 1.27 when load 115 was not used, it was confirmed that Example 2 also has the effect of improving Plt. Therefore, in cases where the capacity of heater 114 is large, and Plt does not fall below the limit value with Example 1 alone, combining Example 1 and Example 2 may make it possible to reduce Plt below the limit value. [Examples]

[0031] Example 3 also suppresses flicker in terms of the magnitude (amount of fluctuation) of power consumption fluctuations, but in Example 3, the load consuming power is assumed to be the heat pump cooling unit of the refrigerator 109. The heat pump cooling unit has a condenser through which a refrigerant is circulated, a heat exchanger, a compressor, a fan, etc., and supplies cold air into the refrigerator 109.

[0032] Figure 10 shows the output timing of the control signals that turn the heater and the cooler ON / OFF in Example 3. As shown in Figure 10, in Example 3, when the heater 114 is ON, the cooler 109 (for example, the compressor of the heat pump cooling unit) is OFF, and when the heater 114 is OFF, the cooler 109 is ON. By controlling the ON / OFF timing of the heater 114 and the cooler 109 to be in opposite phases, fluctuations in the overall power consumption of the automatic analyzer 100 are suppressed. In addition, there is the advantage that the power consumption for flicker suppression can be effectively utilized for cooling in the cooler 109. [Examples]

[0033] Examples 2 and 3 involve setting the ON / OFF timing of the heater and load to be in opposite phases, requiring that the ON / OFF switching cycles be the same for both the heater and the load. In contrast, Example 4 enables improvement of Plt even when the ON / OFF switching cycles differ between the heater and the load (refrigerated storage).

[0034] Figure 11 shows the output timing of the control signals that turn the heater and the refrigerator ON / OFF in Example 4. In Example 4, as shown in Figure 11, the switching cycle of the refrigerator (load) is twice that of the heater. However, the timing of when the load (refrigerator) turns from OFF to ON is set so as not to overlap with the timing of when the heater turns from OFF to ON. As a result, the effect of suppressing fluctuations in the overall power consumption of the automatic analyzer 100 to a certain extent can be obtained.

[0035] Furthermore, the above-described Examples 1 to 3 are detailed explanations provided to clarify the present invention, and are not necessarily limited to those comprising all the described configurations. In addition, it is possible to replace some of the configurations of one example with those of another example, and a certain example It is also possible to add configurations from other embodiments to this configuration. Furthermore, it is possible to add, delete, or replace parts of the configuration in each embodiment with other configurations. [Explanation of symbols]

[0036] 100...Automatic analyzer, 101...Sample dispensing mechanism, 102...Controller, 103...Rack, 104...Sample transport mechanism, 105...Washing mechanism, 106...Reagent dispensing mechanism, 107...Light source, 108...Reagent container, 109...Refrigerator, 110...Spectrophotometer, 111...Incubator, 112...Reaction vessel, 113...Stirring mechanism, 114...Heater, 115...Load, 116...Reaction disk.

Claims

1. A constant temperature bath for storing constant temperature water to maintain the mixture of the sample and reagent in the reaction vessel at a predetermined temperature, A heater for heating the constant-temperature water, An automatic analyzer comprising a control unit for controlling the heater, The system further includes a relay board that switches between supplying and de-supplying power to the AC power supply and the heater, The relay board has a zero-crossing function that switches the supply of AC voltage from the AC power source at the timing of the zero-crossing point. If the pulse width of the ON signal, which is a control signal to turn the heater ON, is a (ms), and the pulse width of the OFF signal, which is a control signal to turn the heater OFF, is b (ms), then a and b are fixed lengths, and a < b. An automatic analyzer characterized in that, when the frequency of the AC power supply is S (Hz), a < 500 / S and 500 / S < b.

2. In the automated analyzer described in claim 1, The control unit is characterized by changing the number of ON signals contained within a certain period of time according to the temperature of the constant-temperature water.

3. In the automated analyzer described in claim 2, The control unit is characterized in that, after outputting the ON signal, it does not continuously output the ON signal, but instead outputs the OFF signal.

4. In the automated analyzer described in claim 3, An automatic analyzer characterized in that, when the OFF signal is output continuously, the sum of the total output time of the continuous OFF signal and the output time of the ON signal is less than 100 ms.

5. In the automated analyzer described in claim 1, With additional power-consuming loads, An automatic analyzer characterized in that the load is OFF when the heater is ON, and the load is ON when the heater is OFF.

6. In the automated analyzer described in claim 1, With additional power-consuming loads, An automatic analyzer characterized in that the timing at which the load switches from OFF to ON does not coincide with the timing at which the heater switches from OFF to ON.

7. In the automated analyzer according to claim 5 or 6, The automatic analyzer is characterized in that the load is a cooling unit of a refrigerator for keeping reagents cold.

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