Automatic analyzer and method for determining state thereof

Abstract

The objective of the present invention is to provide a highly reliable automated analyzing device, and an abnormality determining method for the same. To this end, the present invention provides an automated analyzing device comprising an agitating unit for radiating ultrasonic waves into a reaction vessel to agitate a specimen and a reagent, a power amplifier for applying a voltage to a piezoelectric element of the agitating unit, an impedance measuring unit for measuring an electrical impedance of the piezoelectric element of the agitating unit, an analyzing unit for performing component analysis of a reaction solution of the specimen and the reagent, and a control unit for controlling the agitating unit, the power amplifier, the impedance measuring unit, and the analyzing unit, wherein: a plurality of the agitating units are provided; and the control unit determines, on the basis of the electrical impedance measured by the impedance measuring unit for the plurality of agitating units, a state of connection between the agitating units and either the power amplifier or the impedance measuring unit, or a state of inclination of the automated analyzing device.

Description

[Technical field]

[0001] The present invention relates to an automatic analyzer and an abnormality determination method thereof. [Background technology]

[0002] A technology has been developed that irradiates the reaction liquid in a reaction vessel with ultrasonic waves to generate a flow in the specimen and reagent contained in the reaction liquid and stir the specimen and reagent, and this technology has already been implemented in an automatic analyzer. This stirring method using ultrasonic waves can stir the reaction liquid without contact, so it is possible to avoid carryover of specimens and reagents and carryover of washing water caused by using a stirrer or the like. For example, Patent Document 1 discloses an automatic analyzer that detects the position of the liquid level by arranging multiple electrodes that generate ultrasonic waves and measuring the difference in impedance between the electrodes. Patent Document 2 discloses an automatic analyzer that detects the presence or absence of a reaction liquid by measuring the impedance of a piezoelectric element in the stirring section. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-40843 A [Patent Document 2] JP 2010-96638 A Summary of the Invention [Problem to be solved by the invention]

[0004] In order to improve the processing capacity of an automatic analyzer, if multiple stirring units are provided and connected to the host computer with connectors of the same shape, incorrect insertion of the connectors may cause abnormalities in the wiring to each stirring unit. If each stirring unit is connected to the host computer in an unintended combination, a discrepancy occurs between the preset stirring parameters and the reaction liquid being stirred, resulting in insufficient stirring and inability to output appropriate analysis results. In addition, if the automatic analyzer is tilted due to a dent in the installation surface, it will not be able to output appropriate analysis results.

[0005] An object of the present invention is to provide a highly reliable automatic analyzer and an abnormality determination method thereof. [Means for solving the problem]

[0006] In order to solve the above problems, the automatic analyzer of the present invention is an automatic analyzer comprising: a stirring unit that stirs a sample and a reagent by irradiating an ultrasonic wave into a reaction vessel; a power amplifier that applies a voltage to a piezoelectric element of the stirring unit; an impedance measuring unit that measures the electrical impedance of the piezoelectric element of the stirring unit; an analysis unit that performs a component analysis of a reaction solution of the sample and the reagent; and a control unit that controls the stirring unit, the power amplifier, the impedance measuring unit, and the analysis unit, wherein the automatic analyzer has a plurality of stirring units, and the control unit determines the connection state of the stirring unit and the power amplifier or the impedance measuring unit, or the tilt state of the automatic analyzer, based on the electrical impedance measured by the impedance measuring unit for the plurality of stirring units.

[0007] In addition, the abnormality determination method of the present invention is an abnormality determination method for an automatic analyzer comprising a stirring unit that stirs a sample and a reagent by irradiating an ultrasonic wave into a reaction vessel, a power amplifier that applies a voltage to a piezoelectric element of the stirring unit, an impedance measuring unit that measures the electrical impedance of the piezoelectric element of the stirring unit, and an analysis unit that performs component analysis of a reaction solution of the sample and the reagent, and determines the connection state of the stirring unit and the power amplifier or the impedance measuring unit, or the tilt state of the automatic analyzer, based on the electrical impedance measured by the impedance measuring unit for at least two or more of the multiple stirring units. Effect of the Invention

[0008] According to the present invention, it is possible to provide a highly reliable automatic analyzer and an abnormality determination method thereof. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic configuration diagram of an automatic analyzer according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing the configuration of a stirring unit and a power amplifier and an impedance measuring unit connected thereto. [Diagram 3] FIG. 4 is a diagram showing details of the configuration of an impedance measuring circuit. [Figure 4A] An example of the ImpS measurement results of a piezoelectric element in air. [Figure 4B] An example of the ImpS measurement results when one side of the piezoelectric element is in contact with constant temperature water. [Diagram 5] FIG. 13 is a diagram showing the effect of a standing wave between a reaction vessel and a piezoelectric element. [Figure 6] 6 is a graph showing frequency characteristics of electrical impedance when a liquid is present and not present at the position of the split electrodes. [Figure 7] 13 is a graph showing the relationship between Esw and the ID number of each segment electrode when different amounts of water are placed in a reaction vessel. [Figure 8] FIG. 13 is a schematic diagram showing a case where the stirring unit is normally connected to the relay board. [Figure 9]FIG. 13 is a schematic diagram showing a case where the stirring unit is not normally connected to the relay board. [Figure 10] 11 is a part (first half) of a flowchart showing a method for determining whether a connector is correctly inserted into a stirring portion. [Figure 11] 11 is the remaining part (second half) of the flowchart showing a method for determining whether a connector is correctly inserted into a stirring portion. [Figure 12] 13 is a diagram showing the water level of constant temperature water when determining the inclination of a constant temperature bath. FIG. [Figure 13] 13 is a graph showing the liquid level of constant temperature water in each stirring unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0011] Fig. 1 is a schematic diagram of an automatic analyzer according to this embodiment. As shown in Fig. 1, the automatic analyzer includes a specimen storage section 101, a reagent storage section 102, a reaction section 103, stirring sections 104 to 109, an analysis section 110, a cleaning section 111, a specimen dispensing mechanism 113, and a reagent dispensing mechanism 115. Although not shown in Fig. 1, the automatic analyzer further includes a control section (host computer) configured by electronic circuits and a storage device, and the control section controls the operation of each section and mechanism.

[0012] The specimen storage section 101 stores specimen containers such as test tubes, and specimens 112 are placed in the specimen containers. The reaction section 103 is composed of a rotatable reaction disk, and reaction containers 114 (reaction cells) are arranged in a circumferential shape on the reaction disk. The reaction disk also has a thermostatic chamber that holds constant temperature water at a specified temperature, and the constant temperature water circulating in the thermostatic chamber comes into contact with the reaction containers 114, thereby maintaining the reaction containers 114 at a specified temperature. The specimen dispensing mechanism 113 aspirates an amount of specimen 112 required for analysis from the specimen container, and discharges the aspirated specimen 112 into the reaction containers 114 on the reaction section 103. The reagent dispensing mechanism 115 aspirates an amount of reagent 116 required for analysis from the reagent storage section 102, and discharges the aspirated reagent 116 into the reaction containers 114. A plurality of stirring sections 104 to 109 are arranged in a line on the outer periphery of the reaction disk, and each stirs the specimen 112 and reagent 116 discharged into the reaction containers 114. The analysis unit 110 performs component analysis by measuring the absorbance of the reaction solution of the sample 112 and the reagent 116 in which the reaction has been promoted. The washing unit 111 washes the reaction container 114 after the absorbance measurement has been completed. The next sample 112 is dispensed by the sample dispensing mechanism 113 into the reaction container 114 washed by the washing unit 111, and the same sequence is repeated thereafter.

[0013] Here, the stirring units 104 to 109 irradiate ultrasonic waves to the reaction vessel 114, and use vibration, acoustic flow, acoustic radiation pressure, etc. to stir the specimen 112 and the reagent 116 in a non-contact manner. By providing a plurality of stirring units, the specimen 112 and the reagent 116 are efficiently stirred, and high processing capacity is achieved. In this embodiment, constant temperature water is used as the liquid that mediates the sound waves, but water other than constant temperature water or liquid other than water may also be used. Furthermore, as long as vibrations or the like are imparted to the specimen 112 and the reagent 116, sound waves other than ultrasonic waves may also be used.

[0014] Fig. 2 is a diagram showing the configuration of the stirring section, and the power amplifier and impedance measuring section connected thereto. In Fig. 2, the stirring section 104 is shown in a vertical cross section along the radial direction of the specimen storage section 101, and the electrical circuit arranged on the host computer side with respect to the connector 201 is shown in a schematic configuration. The stirring section 104 will be described below as an example, but the same applies to the stirring sections 105 to 109.

[0015] 2, the stirring unit 104 includes a piezoelectric element 202 that generates ultrasonic waves, a jig 203 for attaching the piezoelectric element 202 to the thermostatic chamber 117, a reflector 223 that reflects ultrasonic waves transmitted through the reaction vessel 114 and the like toward the reaction vessel 114, and a connector 201 that electrically connects the piezoelectric element 202 to the host computer. The piezoelectric element 202 also has split electrodes 204, 209 provided on one surface (the air side) in contact with the air, and a constant-temperature water side electrode 205 provided on the other surface (the constant-temperature water side) in contact with the constant-temperature water 208. A part of the constant-temperature water side electrode 205 is folded back along the lower end face of the piezoelectric element 202 to the air side.

[0016] The split electrodes 204, 209 are split into a plurality of electrodes at different height positions. In this embodiment, an example in which 13 split electrodes are provided (only a portion of them is shown in FIG. 2 and the like) will be described, but the number of split electrodes is not limited to 13. The dimensions and shape of each split electrode can be designed individually and arbitrarily, but in this embodiment, the first to twelfth split electrodes 204 from the top all have the same shape (same width and length), and only the thirteenth (bottom) split electrode 209 is formed slightly longer than the other split electrodes 204. Each split electrode is connected to each pin of the connector 201 in a one-to-one relationship.

[0017] Next, the configuration of the electrical circuit on the host computer side will be described. First, the power amplifier 206 applies a voltage to the divided electrodes to drive the piezoelectric element 202 and generate ultrasonic waves. As shown in FIG. 2, the power amplifier 206 specifically includes a function generating circuit 210 that generates a drive waveform, a final stage amplifier circuit 211 that amplifies the waveform to a desired power, and a current monitor 212 that measures the current flowing through the piezoelectric element 202 when a voltage is applied. The current monitor 212 can be configured to utilize electromagnetic coupling, for example. On the other hand, the impedance measuring circuit 207 measures the frequency characteristic of the electrical impedance of the piezoelectric element 202 (hereinafter sometimes abbreviated as "ImpS"). The ImpS of the piezoelectric element 202 is represented, for example, by a set of ImpS applied to each divided electrode (i.e., ImpS between each divided electrode 204, 209 and the constant temperature water side electrode 205).

[0018] The power amplifier 206 is provided with a first interface unit 221 that connects to a host computer, and the host computer controls the power amplifier 206 via this first interface unit 221. Similarly, the impedance measuring circuit 207 is provided with a second interface unit 222 that connects to the host computer, and the host computer controls the impedance measuring circuit 207 via this second interface unit 222. In addition, the impedance measuring circuit 207 transmits the measurement result of ImpS to the host computer via the second interface unit 222.

[0019] Here, the power amplifier 206 and the impedance measuring circuit 207 are connected to the stirring unit 104 via the connector 201. Furthermore, a relay group 213 is arranged between the power amplifier 206 and the impedance measuring circuit 207 and the connector 201. The relay group 213 includes a plurality of switches, and opening and closing of each switch is controlled by a command from the host computer. That is, the relay group 213 functions as a switch device that switches the connection between the power amplifier 206 and the impedance measuring circuit 207 and each of the split electrodes 204, 209.

[0020] The host computer detects the liquid level (liquid level height) of the liquid in the reaction vessel 114 (a specific example of the detection method will be described later). Furthermore, the host computer selects one or more of the divided electrodes 204, 209 at appropriate positions according to the liquid level position, and controls the relay group 213 to apply a voltage to the selected divided electrodes 204, 209. In this manner, the irradiation position of the ultrasonic waves on the reaction vessel 114 is adjusted.

[0021] A first changeover switch 215 is provided between the power amplifier 206 and the impedance measurement circuit 207 and the relay group 213, for switching between connecting the piezoelectric element 202 to the power amplifier 206 and connecting the piezoelectric element 202 to the impedance measurement circuit 207. A second changeover switch 214 is provided between the impedance measurement circuit 207 and the connector 201, for switching between connecting the impedance measurement circuit 207 to the piezoelectric element 202 and connecting the impedance measurement circuit 207 to ground. For example, during a stirring operation, the first changeover switch 215 is connected to a terminal 216 of the power amplifier 206, and the second changeover switch 214 is connected to a terminal 219 (finally connected to ground 220). On the other hand, during ImpS measurement, the first changeover switch 215 is connected to an output terminal 217 of the impedance measurement circuit 207, and the second changeover switch 214 is connected to an input terminal 218 of the impedance measurement circuit 207.

[0022] In this way, the host computer of this embodiment applies a voltage to each of the divided electrodes 204, 209 via the power amplifier 206, and measures ImpS of the piezoelectric element 202 via the impedance measuring circuit 207. Note that the impedance measuring circuit 207 does not need to be configured independent of the host computer as shown in Fig. 2, and may be configured as a single electronic circuit in which the impedance measuring circuit 207 and the host computer are integrated.

[0023] 3 is a diagram showing the details of the configuration of the impedance measuring circuit 207. In the impedance measuring circuit 207 shown in FIG. Digital synthesizer (hereinafter abbreviated as "DDS") 301 generates a sinusoidal waveform voltage of an arbitrary frequency. The sinusoidal waveform voltage generated by DDS 301 is amplified by amplifier 302 and output from output terminal 217. Output terminal 217 is connected to split electrode 204 via first changeover switch 215 and relay group 213, and split electrode 204 applies the sinusoidal waveform voltage to piezoelectric element 202.

[0024] Here, the magnitude of the applied voltage can be appropriately designed according to the characteristics of the piezoelectric element 202, but if the voltage during ImpS measurement is set to a smaller value than during stirring operation (for example, a voltage called a weak voltage), damage to the piezoelectric element 202 can be prevented. When a voltage is applied, the current flowing through the piezoelectric element 202 flows into the input terminal 218 via the constant temperature water side electrode 205 and the relay group 213, and is detected as a voltage value by the detection resistor 305.

[0025] The voltage signal detected by the detection resistor 305 is further amplified by a logarithmic amplifier 307 (LogAmp) via an operational amplifier 306 that is linearly amplified with an appropriate gain. The voltage applied to the piezoelectric element 202 from the output terminal 217 is input to a micro control unit (hereinafter abbreviated as "MCU") 310 via a wiring 308. The voltage amplified by the logarithmic amplifier 307 is also input to the MCU 310 via a wiring 309. In the embodiment shown in FIG. 3, the resolution of the A / D converter built into the MCU 310 is assumed to be about 8 to 10 bits, so the logarithmic amplifier 307 is used. However, when the MCU 310 is equipped with an A / D converter with a higher resolution, a linear amplifier may be used instead of the logarithmic amplifier.

[0026] The voltage signal input to the MCU 310 is A / D converted. The MCU 310 transmits a control signal 311 to the DDS 301 to sweep the frequency of the sine wave to be generated within a desired frequency range. The frequency at this time, the applied voltage from the output terminal 217, and the measured voltage corresponding to the current flowing through the piezoelectric element 202 are stored in the memory of the MCU 310 and transmitted as the ImpS measurement result to the host computer via the second interface unit 222.

[0027] Fig. 4A shows an example of the results of measuring ImpS of piezoelectric element 202 in air, and Fig. 4B shows an example of the results of measuring ImpS with one side of the same piezoelectric element 202 in contact with constant temperature water. In Fig. 4A and Fig. 4B, the horizontal axis represents the driving frequency, and the vertical axis represents the absolute value |Z| of the electrical impedance.

[0028] 4A, the frequency at which the absolute value |Z| of ImpS becomes the minimum value 402 is the resonant frequency 403 of the piezoelectric element 202. The phase difference at the resonant frequency 403 is almost zero, and this resonant frequency 403 means the point at which the piezoelectric element 202 changes from capacitive to inductive. Also, at this resonant frequency 403, the piezoelectric element 202 vibrates more greatly than when it is driven at other frequencies, and it is considered that the piezoelectric element 202 is in a resonant state in the thickness direction.

[0029] 4A, the second profile group 404 in Fig. 4B has a resonant frequency 406 that is almost the same as the resonant frequency 403. However, the absolute value |Z| of the electrical impedance at the resonant frequency in Fig. 4B, i.e., the minimum value 405 of the absolute value |Z| of the electrical impedance in the second profile group 404, is higher than the minimum value 402 of the absolute value |Z| of the electrical impedance in the first profile group 401.

[0030] Here, the specific acoustic impedance of water is 3000 times that of air, and since a high acoustic impedance increases the acoustic load, the electrical impedance increases accordingly. In other words, in the case of Fig. 4B, it is considered that the vibration of the surface of the piezoelectric element 202 in contact with the constant temperature water is propagated to the constant temperature water, and ultrasonic waves are irradiated from the surface of the piezoelectric element 202.

[0031] 5 shows the effect of a standing wave between reaction vessel 114 and piezoelectric element 202. An ultrasonic wave generated by applying a voltage to piezoelectric element 202 propagates through constant temperature water 208 and propagates as a traveling wave 501 to reaction vessel 114. If no liquid is present in reaction vessel 114, the ultrasonic wave that reaches reaction vessel 114 is almost totally reflected by inner surface 502 of reaction vessel 114, generating reflected wave 503. That is, between inner surface 502 of reaction vessel 114 and piezoelectric element 202, traveling wave 501 and reflected wave 503 are combined, generating standing wave 504.

[0032] Ultrasonic waves have the property of not being reflected inside a homogeneous material, in other words, of being reflected at the material boundary between different materials. Therefore, ultrasonic waves are almost totally reflected at the material boundary between materials whose acoustic impedances are significantly different, such as between water and air. In this embodiment, the ultrasonic waves reach the reaction vessel 114 via the constant temperature water, which is a liquid, so the magnitude of the standing wave 504 varies greatly depending on whether or not liquid exists in the reaction vessel 114.

[0033] Next, a method for detecting the liquid level by utilizing the magnitude of the influence of the standing wave 504 will be described. When the specimen 112 or the reagent 116 is present in the reaction vessel 114, the difference in acoustic impedance of the material boundary is small, so the influence of the standing wave is small. On the other hand, when the specimen 112 or the reagent 116 is not present in the reaction vessel 114, the difference in acoustic impedance of the material boundary is large, so the influence of the standing wave is large. As shown in FIG. 5, the ID numbers of the divided electrodes 204, 209 of the piezoelectric element 202 are 1, 2, ... 13 from the top, and the electric impedance of each is measured to measure the magnitude of the influence of the standing wave on each divided electrode 204, 209, so that the liquid height in the reaction vessel 114 can be measured.

[0034] Fig. 6 shows the frequency characteristics of the electrical impedance when liquid is present and not present at the position of the split electrode. The horizontal axis is frequency, and the vertical axis is absolute value of electrical impedance. It can be seen that ImpS measured with a split electrode (e.g., ID number 1) at a height where no liquid is present in the reaction vessel 114 has several poles due to the influence of standing waves, as shown by dotted line 601 in Fig. 6, and fluctuates greatly. On the other hand, ImpS measured with a split electrode (e.g., ID number 13) at a height where liquid is present in the reaction vessel 114 has fewer poles and fluctuates less, as shown by solid line 602 in Fig. 6.

[0035] In this way, by determining the magnitude of the influence of the standing wave from the magnitude of the fluctuation of ImpS measured by the impedance measuring circuit 207, it is possible to detect the presence or absence of liquid and the height of the liquid surface in the reaction vessel 114. The following (Equation 1) is an equation for quantitatively deriving the magnitude of the fluctuation of ImpS (hereinafter defined as Esw).

[0036]

number

[0037] The specific procedure for deriving Esw is to first measure the frequency characteristic Z(f) of the electrical impedance of a specific divided electrode (e.g., ID number 1). At this time, the range of frequencies to be swept should be larger than the range of f1 and f2 used in the above (Equation 1). After that, the control unit smoothes the waveform, and there are various methods for smoothing, such as the moving average method. The frequency characteristic of the electrical impedance after the smoothing filter is set as Zflt(f), and the difference between Z(f) and Zflt(f) is quantified by performing definite integration as shown in (Equation 1). In other words, the difference between the frequency characteristics of the electrical impedance before and after the smoothing filter processing in the divided electrode is quantified, and this difference quantifies the influence of the standing wave at the position of each divided electrode.

[0038] 7 is a graph showing the relationship between Esw and the ID number of each divided electrode when different amounts (0 μL, 45 μL, 90 μL, 135 μL, 180 μL, 225 μL) of water are poured into reaction vessel 114. As can be seen from FIG. 7, Esw draws a different curve depending on the amount of water present in reaction vessel 114. Here, a predetermined threshold value X is determined in advance based on the relationship between Esw of each divided electrode and the amount of water in reaction vessel 114, and the height of the liquid level in reaction vessel 114 can be detected by assuming that no water is present at the height of the divided electrodes where Esw exceeds threshold value X.

[0039] Two examples of the method for determining an abnormality in an automatic analyzer based on electrical impedance will be described below. EXAMPLES

[0040] In the first embodiment, the connection state between the stirring units 104-109 and the power amplifier 206 or the impedance measuring circuit 207, for example, whether or not the connector 201 is erroneously inserted, is determined based on whether or not the liquid in the reaction vessel 114 has been detected. Fig. 8 is a schematic diagram showing a case where the stirring units 104, 105 are normally connected to the relay boards 802, 804, and Fig. 9 is a schematic diagram showing a case where the stirring units 104, 105 are not normally connected to the relay boards 802, 804.

[0041] 8, relay board 802, which is provided with a relay group corresponding to stirring unit 104, is normally connected to stirring unit 104 via wiring 803. Similarly, relay board 804, which is provided with a relay group corresponding to stirring unit 105, is normally connected to stirring unit 105 via wiring 805. In this way, the stirring units, relay boards, and wiring are connected in the correct combinations, so that the desired stirring operation can be performed.

[0042] However, if the connectors 201 are the same shape, due to a mistake in wiring connection during assembly of the device, for example, as shown in Fig. 9, a relay board 802 provided with a relay group corresponding to the stirring unit 104 may be mistakenly connected to the stirring unit 105 via wiring 803. In this case, the ultrasonic stirring operation set by the dispensing parameters, etc., may not be performed when stirring the desired reaction vessel 114, and the analysis results may be adversely affected by insufficient stirring. In addition, applying a strong voltage even when no specimen 112 or reagent 116 is present may cause damage to the stirring unit 104 due to blank firing.

[0043] In order to avoid such problems, in this embodiment, when the device is assembled, a determination is made as to whether or not the connector 201 has been erroneously inserted between the stirring sections 104 to 109 and the relay boards 802 to 809. An outline of the determination method will now be described.

[0044] First, the control unit uses the cleaning unit 111 to discharge pure water into a specific reaction vessel 114 (hereinafter, the reaction vessel is referred to as a reference cell 801). At this time, it is necessary to ensure that no liquid such as pure water, a specimen, or a reagent exists in the reaction vessel 114 other than the reference cell 801.

[0045] Next, the control unit moves the reference cell 801 to the stirring position of the stirring unit 104 by rotating the reaction disk 810. Then, the control unit checks the liquid level in the reference cell 801 by the method described above. At this time, if there is no erroneous insertion of the connector 201 and the relay board 802 and the stirring unit 104 are properly connected by the wiring 803, the liquid level is detected. On the other hand, if there is erroneous insertion of the connector 201, the liquid level is not detected.

[0046] After the liquid level is checked at the stirring position of the stirring unit 104, the liquid level is similarly checked at the stirring positions of the stirring units 105 to 109. If the level of pure water in the reference cell 801 can be determined without using all of the divided electrodes, the determination may be made using only some of the divided electrodes. Also, the reference cell 801 may contain a liquid other than pure water. Furthermore, a method may be used that detects only the presence or absence of liquid, rather than the liquid level.

[0047] The abnormality determination method described above will be described in more detail with reference to Fig. 10 and Fig. 11. Fig. 10 and Fig. 11 are flowcharts showing a method for determining whether the connector 201 is correctly inserted into the stirring units 104 to 109, with Fig. 10 showing a part (first half) and Fig. 11 showing the remaining part (second half).

[0048] 10, the control unit of the automatic analyzer starts the operation of determining anomaly (step S101). Next, the control unit checks the water level of the thermostatic bath 117 (step S102). The method of checking the water level may be a method using a water level sensor mounted on the automatic analyzer, or a method of detecting the liquid level based on ImpS measured by the impedance measuring circuit 207, as described above.

[0049] If the thermostatic bath 117 has not reached the predetermined water level, the control unit outputs a system alarm and ends the abnormality determination operation (step S103). On the other hand, if the thermostatic bath 117 has reached the predetermined water level, the control unit uses the cleaning unit 111 to dispense pure water into the reference cell 801 (step S104). Dispensing parameters for dispensing pure water into the reference cell 801 are stored in the control unit. The amount of pure water dispensed into the reference cell 801 can be set arbitrarily as long as it is within a range that can be measured by each stirring unit.

[0050] Next, the control unit rotates the reaction disk 810 to a preset angle in order to move the reference cell 801 to the stirring position of the stirring unit 104 (step S105). In this embodiment, the reaction disk 810 rotates counterclockwise.

[0051] After that, the control unit attempts to derive the Esw of the reference cell 801 using each divided electrode of the stirring unit 104 (step S106). In this embodiment, it is assumed that the Esw is derived from all divided electrodes (ID numbers 1 to 13) of the piezoelectric element 202, but the Esw may be derived using only some of the divided electrodes. If the Esw cannot be derived due to erroneous insertion of the connector 201, the control unit outputs a system alarm and ends the operation of abnormality determination (step S107). On the other hand, if the Esw can be derived, the control unit stores the derived Esw (step S108) and then determines whether the derivation of Esw has been completed in all stirring units (step S109). At this stage, the derivation of Esw other than that of the stirring unit 104 has not been completed, so the process returns to step S105, and the control unit rotates the reaction disk 810 to a predetermined angle set in advance to move the reference cell 801 to the stirring position of the next stirring unit 105.

[0052] Thereafter, the same operations are repeated, and when the derivation of Esw of the mixing units 104 to 109 is completed, the operation of FIG. 10 ends and the operation of FIG. 11 starts.

[0053] 11, first, the control unit checks whether or not any of the Esw (represented as Esw1, Esw2, Esw3, Esw4, Esw5, and Esw6, respectively) measured at the stirring positions of the stirring units 104 to 109 exceeds a preset value (threshold value Z) (step S110). If no stirring unit has Esw>Z, this means that the liquid level of pure water in the reference cell 801 has been detected normally at the stirring positions of all the stirring units, and the abnormality determination operation ends normally (step S111).

[0054] On the other hand, if there is a stirring part where Esw>Z, the liquid level of the pure water in the reference cell 801 cannot be detected normally at the stirring position of the stirring part, so there is a possibility that the connector 201 is erroneously inserted. Therefore, in this case, the control unit outputs a system error (step S112), displays the stirring part where Esw>Z, and ends the judgment operation (step S113). EXAMPLES

[0055] In the second embodiment, the tilt state of the automatic analyzer is determined based on the liquid level of the constant temperature water detected in each stirring unit. Generally, an automatic analyzer has a bias in its own weight, and therefore the floor surface corresponding to the heavy part of the installation location of the automatic analyzer may sink, causing the automatic analyzer to tilt. If the automatic analyzer tilts, the liquid level in the constant temperature bath 117 or reaction vessel 114 may differ from place to place, which may cause liquid leakage or failure to perform the stirring operation according to the set parameters.

[0056] Therefore, in this embodiment, the liquid level of the constant temperature water at each location is detected based on whether or not the multiple split electrodes 204, 209 provided on the piezoelectric element 202 of each stirring section can detect the constant temperature water. If the constant temperature bath 117 is tilted, the water level of the constant temperature water may vary depending on the location. Therefore, the control unit of this embodiment detects the water level of the constant temperature water at several different locations and determines the tilt of the constant temperature bath 117 based on whether or not the difference in water level at each location is within a certain range.

[0057] Fig. 12 is a diagram showing the water level of the constant temperature water when determining the inclination of the constant temperature bath 117. In this embodiment, when determining the inclination state of the constant temperature bath 117, as shown in Fig. 12, the water level of the constant temperature water is set to a lower water level than that during component analysis, for example, one-third of the water level during component analysis. Then, the control unit derives Esw at this time using each of the divided electrodes 204, 209 of the stirring units 104 to 109. Furthermore, the control unit compares the derived Esw with the threshold value X by the method described above, and detects the liquid level in each stirring unit.

[0058] Fig. 13 is a graph showing the liquid level of the constant temperature water in each stirring unit. As shown in Fig. 13, the relationship between the position of the stirring unit and the liquid level of the constant temperature water can be approximated by a linear function. If the slope of this linear function is within a preset range, that is, if the lower limit value<slope of the linear function<upper limit value, the slope of the constant temperature bath 117 is within the tolerance, so the control unit determines that there is no problem. On the other hand, if the slope of the linear function is outside this range, that is, if the slope of the linear function<lower limit value or the upper limit value<slope of the linear function, the slope of the constant temperature bath 117 is outside the tolerance, so the control unit outputs a system alarm. The abnormality detection described in Examples 1 and 2 is assumed to be performed when the automatic analyzer is installed, when the stirring unit is replaced, during periodic maintenance, etc., but it may also be performed every time the automatic analyzer is started up.

[0059] The present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the configurations described. It is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is possible to add, delete, or replace a part of the configuration of each embodiment with another configuration. [Explanation of symbols]

[0060] 101: specimen storage section, 102: reagent storage section, 103: reaction section, 104 to 109: stirring section, 110: analysis section, 111: cleaning section, 112: specimen, 113: specimen dispensing mechanism, 114: reaction vessel, 115: reagent dispensing mechanism, 116: reagent, 117: thermostatic bath, 201: connector, 202: piezoelectric element, 203: jig, 204: split electrode, 205: thermostatic water side electrode, 206: power amplifier , 207: impedance measuring circuit, 208: constant temperature water, 209: split electrode (lower side), 210: function generating circuit, 211: final stage amplifier circuit, 212: current monitor, 213: relay group, 214: second changeover switch, 215: first changeover switch, 216: terminal, 217: output terminal, 218: input terminal, 219: terminal, 220: ground, 221: first interface section, 222: second interface section, 223: reflector, 301: DDS, 302: amplifier, 305: detection resistor, 306: operational amplifier, 307: logarithmic amplifier, 308, 309: wiring, 310: MCU, 311: control signal, 401: first profile group, 402: minimum value (of first profile group), 403: resonance frequency (of first profile group), 404: second profile Group, 405: minimum value (of the second profile group), 406: resonant frequency (of the second profile group), 501: traveling wave, 502: inner surface (of the reaction vessel), 503: reflected wave, 504: standing wave, 601: dotted line, 602: solid line, 801: reference cell, 802: relay board, 803: wiring, 804: relay board, 805: wiring, 806-809: relay board, 810: reaction disk

Claims

1. an agitation unit that agitates the sample and the reagent by irradiating the reaction vessel with ultrasonic waves; a rotatable reaction disk on which the reaction vessels are arranged in a circumferential manner; A power amplifier that applies a voltage to the piezoelectric element of the stirring unit; an impedance measuring unit for measuring the electrical impedance of the piezoelectric element of the stirring unit; an analysis unit that performs component analysis of a reaction solution of the sample and the reagent; an automatic analyzer including a controller for controlling the stirring unit, the reaction disk, the power amplifier, the impedance measuring unit, and the analysis unit, The stirring unit has a plurality of stirring units, The control unit rotates the reaction disk to move the reaction vessel into which pure water has been ejected to the stirring position of each of the stirring units, and determines the connection status of the stirring unit and the power amplifier or the impedance measuring unit based on the electrical impedance measured by the impedance measuring unit for each of the stirring units.

2. 2. The automated analyzer according to claim 1, The control unit detects the presence or absence of pure water based on the magnitude of fluctuation in the frequency characteristics of the electrical impedance measured by the impedance measuring unit, and if the pure water is detected, determines that the stirring unit and the power amplifier or the impedance measuring unit are normally connected, and if the pure water is not detected, determines that the stirring unit and the power amplifier or the impedance measuring unit are not normally connected.

3. 2. The automated analyzer according to claim 1, The control unit outputs an alarm when the stirring unit is present and is unable to derive the magnitude of fluctuation in the frequency characteristics of the electrical impedance measured by the impedance measuring unit.

4. 2. The automated analyzer according to claim 1, The control unit of the automatic analyzer determines that the stirring unit and the power amplifier or the impedance measuring unit are not properly connected when there is a stirring unit in which the magnitude of fluctuation in the frequency characteristics of the electrical impedance measured by the impedance measuring unit exceeds a predetermined value, and outputs an alarm.

5. an agitation unit that agitates the sample and the reagent by irradiating the reaction vessel with ultrasonic waves; a rotatable reaction disk on which the reaction vessels are arranged in a circumferential manner; A power amplifier that applies a voltage to the piezoelectric element of the stirring unit; an impedance measuring unit for measuring the electrical impedance of the piezoelectric element of the stirring unit; An analysis unit that performs component analysis of a reaction solution of the sample and the reagent, A status determination method in which, for at least two or more of the multiple stirring units, the reaction disk is rotated to move the reaction vessel into which pure water has been ejected to the stirring position of each of the stirring units, and based on the electrical impedance measured by the impedance measuring unit for each of the stirring units, it is determined whether the stirring unit and the power amplifier or the impedance measuring unit are normally connected.

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