Automatic analysis device

Abstract

Provided is an automatic analysis device that can prevent overflow of a waste liquid even when a liquid level sensor in a waste liquid buffer has failed or there has been some kind of trouble or processing delay in control by a computer.　An automatic analysis device according to the present invention comprises an analysis unit that analyzes a sample, a retention part that is connected to the analysis unit via a first channel and temporarily retains a waste liquid that is generated by the analysis unit, a waste liquid accommodation part that is connected to the retention part via a second channel and can accommodate waste liquid that is being retained at the retention part, a first detection unit that detects that the waste liquid retained at the retention part has reached a first liquid level, a second detection unit that detects that the waste liquid retained at the retention part has reached a second liquid level that is higher than the first liquid level, a control unit that performs control to open a second valve that is provided to the second channel when a detection has been made by the first detection unit, and a shutoff unit that performs control to close a first valve that is provided to the first channel when a detection has been made by the second detection unit.

Description

Automatic analyzer

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

[0002] An automatic analyzer that analyzes specimens such as blood and urine discharges waste liquid generated during analysis. Since the waste liquid may contain infectious substances, etc., it is often accumulated in a waste liquid tank. When entrusting a professional recycler to collect the waste liquid tank in which waste liquid containing an organic solvent, etc. is accumulated, since the waste liquid tank designated by the recycler is used, it is difficult to provide a liquid volume sensor for the waste liquid tank designated by the recycler. It is necessary to manage the waste liquid of the automatic analyzer and prevent overflow. Patent Document 1 describes a technique that enables the waste liquid to be discarded without interrupting the operation by implementing a waste liquid buffer for temporarily holding the waste liquid in the waste liquid tank.

[0003] Japanese Unexamined Patent Application Publication No. 2016-095133

[0004] In Patent Document 1, there is a concern that it is not always immediately stopped when the water level sensor in the waste liquid buffer fails or when there is some problem or processing delay in the control of the computer. When the operation is not stopped, the waste liquid continues to flow into the waste liquid buffer while holding the waste liquid, so there is a risk of overflow of the waste liquid from the waste liquid buffer. That is, there is room for improvement in the implementation configuration for reliably preventing the overflow of the waste liquid in the technique described in Patent Document 1.

[0005] An object of the present invention is to provide an automatic analyzer capable of preventing the overflow of waste liquid even when the water level sensor in the waste liquid buffer fails or when there is some problem or processing delay in the control of the computer.

[0006] The present invention, in order to achieve the above objective, has the following configuration: an automatic analyzer comprising: an analysis unit for analyzing a sample; a storage unit connected to the analysis unit via a first flow path for temporarily storing waste liquid generated from the analysis unit; a waste liquid storage unit connected to the storage unit via a second flow path for storing the waste liquid stored in the storage unit; a first detection unit for detecting when the waste liquid stored in the storage unit reaches a first water level; a second detection unit for detecting when the waste liquid stored in the storage unit reaches a second water level higher than the first water level; a control unit for controlling the opening of a second valve provided in the second flow path when the first detection unit detects a change; and a shut-off unit for controlling the closing of a first valve provided in the first flow path when the second detection unit detects a change.

[0007] The automatic analyzer also comprises: an analysis unit for analyzing a sample; a storage unit connected to the analysis unit via a first flow path for temporarily storing waste liquid generated from the analysis unit; a waste liquid storage unit connected to the storage unit via a second flow path for storing the waste liquid stored in the storage unit; a three-way valve provided in the first flow path for branching the flow of waste liquid generated from the analysis unit to either the storage unit or the waste liquid storage unit; a first detection unit for detecting when the waste liquid stored in the storage unit reaches a first water level; a second detection unit for detecting when the waste liquid stored in the storage unit reaches a second water level higher than the first water level; a control unit for controlling the opening of a second valve provided in the second flow path when the first detection unit detects a change; and a flow path switching unit for switching the three-way valve, which was branched to send waste liquid to the storage unit, to send waste liquid to the waste liquid storage unit when the second detection unit detects a change.

[0008] According to the present invention, it is possible to provide an automated analyzer that can prevent waste liquid overflow even if the water level sensor in the waste liquid buffer malfunctions or if there is some malfunction or processing delay in the computer control.

[0009] A diagram showing an example configuration of an automated analyzer. A diagram showing the configuration of Example 1. A flowchart showing the processing flow in Example 1. A diagram showing the configuration of Example 2. A flowchart showing the processing flow in Example 2. A diagram showing the configuration of Example 3. A diagram showing the configuration of Example 4. A diagram showing the configuration of Example 5. A diagram showing the configuration of Example 6. A flowchart showing the processing flow in Example 6. A flowchart showing the processing flow in Example 6. A flowchart showing the processing flow in Example 6.

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

[0011] An example of the configuration of the automated analyzer 100 will be explained using Figure 1. The automated analyzer 100 is a device for qualitative and quantitative analysis of samples such as blood, urine, and cerebrospinal fluid, and comprises a pre-processing unit 101, a separation unit 127, an analysis unit 102, a waste liquid port 105, a storage unit 103, a waste liquid storage unit 104, a control unit 110, a shut-off unit 115, a memory unit 109, an operation unit 111, and a display unit 112. Each part will be described below.

[0012] The pre-processing unit 101 pre-processes the sample and includes a transport path 114, a reaction disk 120, a first reaction vessel transport unit 118, a sample dispensing unit 113, a reagent disk 122, a reagent dispensing unit 123, a magnetic separation unit 124, a second reaction vessel transport unit 125, an evaporation and concentration unit 131, a third reaction vessel transport unit 132, and a concentrated liquid dispensing unit 133. The transport path 114 transports the sample container 107 containing the sample to a position accessible by the sample dispensing unit 113.

[0013] The reaction disk 120 has a plurality of openings 119 in which reaction vessels 116 are placed, and moves the reaction vessels 116 to predetermined positions by rotating. The reaction disk 120 is also maintained at a predetermined temperature. The first reaction vessel transport unit 118 transports unused reaction vessels 116 to the openings 119 and transports used reaction vessels 116 from the openings 119. The sample dispensing unit 113 dispenses the sample from the sample container 107 to the reaction vessels 116 placed in the openings 119.

[0014] The reagent disk 122 stores the reagent container 108, which contains the reagent to be reacted with the sample, and rotates to move the reagent container 108 to a predetermined position. The reagent dispensing unit 123 dispenses the reagent from the reagent container 108 into the reaction vessel 116 into which the sample has been dispensed. In the reaction vessel 116 into which the sample and reagent have been dispensed, the reaction disk 120 is maintained at a predetermined temperature, which promotes the reaction between the sample and the reagent and generates a reaction solution. Note that some reagents contain organic solvents.

[0015] The magnetic separation unit 124 separates the magnetic beads from the reaction liquid contained in the reaction vessel 116 using the magnetic force of a magnet. The second reaction vessel transport unit 125 transports the reaction vessel 116 containing the magnetic beads from the reaction disk 120 to the magnetic separation unit 124, and transports the reaction vessel 116 from which the magnetic beads have been separated from the magnetic separation unit 124 to the reaction disk 120.

[0016] The evaporation and concentration unit 131 concentrates the reaction solution by evaporating excess water from the reaction solution contained in the reaction vessel 116. The third reaction vessel transport unit 132 transports the reaction vessel 116 from the reaction disk 120 to the evaporation and concentration unit 131. The concentrated liquid dispensing unit 133 dispenses the concentrated liquid from the evaporation and concentration unit 131 to the separation unit 127.

[0017] The separation unit 127 separates the analyte from the concentrated liquid dispensed by the concentrated liquid dispensing unit 133, for example by centrifugation.

[0018] The analysis unit 102 performs analysis by detecting the analyte components separated by the separation unit 127. Any analytical method may be used in the analysis unit 102. For example, it may be LC-MS analysis, which connects liquid chromatography (LC) and mass spectrometry (MS), or a combination of LC analysis, biochemical analysis, and genetic analysis.

[0019] The waste liquid storage section 104 receives waste liquid generated in the pre-processing section 101 and the separation section 127 before analysis by the analysis section 102. The pre-processing section 101 and the separation section 127 are provided with a liquid transfer section 121 for discharging the waste liquid to the waste liquid storage section 104. Here, the liquid transfer section 121 may use a gravity-driven discharge method, or a pump may be used to send the waste liquid to the waste liquid storage section 104. In the case of a pump, for example, a peristaltic pump, gear pump, diaphragm pump, syringe pump, etc. may be used. The waste liquid discharged to the waste liquid port 105 is accumulated in the waste liquid storage section 104 via the flow path 106 and the storage section 103. The configuration of the storage section 103 will be described later.

[0020] The control unit 110 is electrically connected to the preprocessing unit 101, the analysis unit 102, the separation unit 127, and the storage unit 103, and controls the operation of each unit and receives the analysis results from the analysis unit 102. It is composed of, for example, an MPU (Micro Processor Unit). The storage unit 109 stores programs and data used to control each unit, analysis results from the analysis unit 102, etc., and is composed of, for example, an HDD (Hard Disk Drive) or an SSD (Solid State Drive). The operation unit 111 receives instructions from the operator and is composed of, for example, a keyboard, mouse, or touch panel. The display unit 112 displays instructions input via the operation unit 111, the status of each unit, analysis results from the analysis unit 102, etc., and is composed of, for example, an LCD monitor or touch panel.

[0021] The power supply 117 is electrically connected to the preprocessing unit 101, the separation unit 127, the analysis unit 102, the liquid delivery unit 121, and the storage unit 103. The shut-off unit 115 is located on the path connecting the liquid delivery unit 121 and the power supply 117, and controls the ON / OFF operation of the liquid delivery unit 121.

[0022] The configuration of the storage section 103 will be explained using Figure 2. The storage section 103 has the function of temporarily storing (holding) the waste liquid that flows from the liquid supply section 121 to the waste liquid storage section 104. It is located above the waste liquid storage section 104 and consists of a storage tank 201 and a solenoid valve 71.

[0023] The storage tank 201 is a container for temporarily storing waste liquid discharged from the waste liquid port 105 via the flow path 106, and is connected to the analysis unit 102 via the first flow path 211. A liquid delivery unit 121 is provided in the middle of the first flow path 211.

[0024] Furthermore, the storage tank 201 discharges waste liquid to the waste liquid containment section 104 via a second flow path 202 connected to its bottom. A solenoid valve 71 is provided in the middle of the second flow path. Since the waste liquid may contain organic solvents, the storage tank 201 is manufactured using a material resistant to organic solvents, such as polypropylene.

[0025] The storage tank 201 is equipped with a first detection unit 203 and a second detection unit 204 as sensors for detecting the water level of the stored waste liquid. The first water level 205, detected by the first detection unit 203, indicates the volume at which the storage tank 201 should be discharged and is set lower than the second water level 206. The second water level 206, detected by the second detection unit 204, indicates the maximum volume of waste liquid that can be stored in the storage tank 201 (in reality, this level is set slightly lower than the amount at which the storage tank would overflow if more waste liquid flowed in, so that even if waste liquid remaining in the flow path flows into the storage tank with a delay, it will not overflow), and is set lower than the water level corresponding to the capacity of the waste liquid storage unit 104. The detection signal from the first detection unit 203 is transmitted to the control unit 110, and the detection signal from the second detection unit 204 is transmitted to the shut-off unit 115.

[0026] For detecting waste liquid, it is preferable to use non-contact sensors such as optical sensors or ultrasonic sensors that are less affected by the properties of organic solvents (conductivity, dielectric constant, chemical resistance). When a general optical sensor equipped with a light-emitting part and a light-receiving part (detection part) is used, an optically transparent material, such as polypropylene, is used for the storage tank 201. When using a contact-type sensor, considering the high impedance characteristic of organic solvents, an amplification circuit that amplifies the input voltage may be combined. However, the circuit constant values ​​of the amplification circuit must be precisely fitted to enable detection of organic solvents. Also, if the flow path from the analysis unit 102 to the storage tank 201 extends vertically downward and the waste liquid flows into the storage tank 201 by gravity, the liquid delivery unit 121 may be a simple valve (solenoid valve, etc.) instead of a liquid delivery pump. In that case, the solenoid valve, which is the liquid delivery unit 121, can be shut off by supplying power for opening and closing from the shut-off unit 115 to the solenoid valve, which is the liquid delivery unit 121.

[0027] The following describes an example of operation using an optical sensor. The first detection unit 203 and the second detection unit 204 distinguish between a state in which light from a light-emitting unit (a light source such as an LED located at the right end of the storage tank 201 in Figure 2) is projected onto a light-receiving unit (a light-receiving element such as a photodiode located at the left end of the storage tank 201 in Figure 2) (light-receiving state) and a state in which light is blocked by the waste liquid held in the storage tank 201, and light from the light-emitting unit does not reach the light-receiving unit (or only a light amount below the threshold for determining that light has been received reaches it) (blocked state). In the light-receiving state, a High level signal (the power supply voltage of the circuit, for example, +5V) is output from the light-receiving unit.

[0028] The control unit 110 controls the opening and closing of the solenoid valve 71 based on the detection signal from the first detection unit 203. When the first detection unit 203 is receiving light, the solenoid valve 71 is closed and the waste liquid discharged from the liquid supply unit 121 is stored in the storage tank 201. When the first detection unit 203 is shielded from light, the solenoid valve 71 is opened and the waste liquid in the storage tank 201 is discharged by gravity into the waste liquid storage unit 104.

[0029] If a computer control malfunction occurs or the first detection unit 203 fails, the detection signal from the first detection unit 203 cannot be recognized by the control unit 110, causing the water level in the storage tank 201 to rise and reach the second detection unit 204. When the second detection unit 204 is blocked from light, the shut-off unit 115 directly cuts off the drive power to the mechanism related to the liquid delivery unit 121 via a predetermined circuit, without going through the processing of the control unit 110. This ensures that the analysis operation can be reliably stopped even if there is a malfunction or processing delay in the computer control. In the storage tank 201, cutting off the power supply to the liquid delivery unit 121 stops the delivery of waste liquid, thus reliably preventing overflow of the storage tank 201.

[0030] In Example 1, overflow of the storage tank 201 is avoided by shutting off the drive power supply to the liquid delivery unit 121 related to the waste liquid discharge operation. However, if the analysis unit 102, which is located upstream of the storage tank 201, is in operation, the waste liquid generated in the analysis unit 102 will continue to flow to the liquid delivery unit 121, and in the worst case, there is a risk that the waste liquid will overflow in the analysis unit 102. As a way to avoid this risk, the power supply to the analysis unit 102 may be shut off at the same time as the power supply to the liquid delivery unit 121 to prevent the generation of new waste liquid and avoid the risk of waste liquid overflowing in the analysis unit 102. Note that if the power supply to the analysis unit 102 is shut off, the sample and reagents being analyzed may be wasted. Therefore, if the time for which the drive power supply to the liquid delivery unit 121 has been shut off exceeds a predetermined time, the power supply to the analysis unit 102 may also be shut off.

[0031] The predetermined time can be set to a time slightly shorter than the time it takes for waste liquid to overflow into the analysis unit 102 after the power supply to the liquid delivery unit 121 has been shut off, which can be determined experimentally in advance. By performing any possible processing on the analysis unit 102 before the predetermined time is reached, it may be possible to reduce waste of samples and reagents. It is preferable to display the remaining time until the predetermined time is reached on the display unit 112 so that the device operator can keep track of the remaining time. An alarm sound may also be sounded at the same time.

[0032] In this embodiment, a relay is used for the interruption unit 115. One end of the relay coil 208 is connected to the second detection unit 204, and the other end of the coil is grounded. The ON / OFF state of the coil 208 opens and closes the contact unit 207 (switch). One end of the contact unit 207 is connected to the power supply 117, and the other end is connected to the liquid supply unit 121 (in other words, the contact unit 207 is located in the path connecting the power supply 117 and the liquid supply unit 121). When the second detection unit 204 is in a light-receiving state, electricity flows through the coil, and the contact unit operates in the ON state. As a result, the circuit becomes a closed loop, and driving power is supplied to the liquid supply unit 121. When the second detection unit 204 is in a light-shielding state, no electricity flows through the coil 208, so the contact unit is in the OFF state. At the same time, the circuit becomes open, and the driving power to the liquid supply unit 121 is cut off. In this embodiment, since the opening and closing of the power supply path is controlled solely by hardware operation, it is possible to detect any malfunction or processing delay in the control of the computer (control unit 110) and shut off the liquid supply unit 121.

[0033] If the second detection unit 204 is in a light-shielding state, the operator must drain the waste liquid from the storage tank 201 in order to resume power supply to the liquid supply unit 121. To drain the waste liquid held in the storage tank 201, for example, a drain cock (not shown) may be provided below the storage tank 201 so that the operator can open the drain cock to drain the liquid.

[0034] The solenoid valve opening and closing control based on detection by the first detection unit 203 and the power supply shut-off control based on detection by the second detection unit 204 are performed almost simultaneously, or more precisely, sequentially in a very short time. If the system is restarted without performing wastewater discharge work, the power supply shut-off based on detection by the second detection unit 204 is performed at the same time as the start of the solenoid valve closing operation based on detection by the first detection unit 203. Even if the operator restarts the system without realizing that the storage tank 201 is full, the power supply to the liquid transfer unit 121 is shut off before the wastewater is sent from the liquid transfer unit 121 to the storage tank 201, thus preventing the storage tank 201 from overflowing.

[0035] A flowchart for monitoring waste liquid in Embodiment 1, which involves shutting off the power supply to the liquid delivery unit 121, will be explained using Figure 3.

[0036] The control unit 110 determines whether the water level of the waste liquid stored in the storage tank 201 is equal to or greater than the first water level 205. If the water level of the waste liquid has reached the first water level 205, the process proceeds to S302; otherwise, the process proceeds to S303 (S301).

[0037] The control unit 110 opens the solenoid valve 71 and waits until a predetermined time t1 has elapsed. When the solenoid valve 71 opens, the waste liquid stored in the storage tank 201 is discharged to the waste liquid storage section 104 (S302). The predetermined time t1 is the time required for the waste liquid stored in the storage tank 201 to reach the first water level 205 to be discharged to the waste liquid storage section 104, and can be calculated, for example, by the following formula.

[0038] t1 = L1 / U + tB ... (Equation 1) Here, L1 is the first water level 205, U is the flow velocity of the waste liquid flowing through the second channel 202, and tB is the buffer time (a margin of time required for the waste liquid to be completely discharged from the storage tank 201, taking into account the viscosity of the waste liquid, etc.).

[0039] The control unit 110 closes the solenoid valve 71 after a predetermined time t1 has elapsed. While the solenoid valve 71 is open, the control unit 110 may issue a command to stop the analysis operation in order to avoid the risk of overflow in the storage tank 201 due to a malfunction of the solenoid valve 71 or the inflow of waste liquid into the storage tank 201.

[0040] The shut-off unit 115 determines, based on the detection signal from the second detection unit 204, whether the water level of the waste liquid stored in the storage tank 201 is equal to or greater than the second water level 206 (S303). If the second detection unit 204 is in a light-shielding state, the contact unit 207 operates in the off state, and the process proceeds to S304. If the second detection unit 204 is in a light-receiving state, the contact unit 207 operates in the on state, the drive voltage is supplied, and the process returns to S301. S301 and S303 are executed almost simultaneously.

[0041] When the second detection unit 204 is in an oblique light state, no current flows through the coil 208, and the contact unit 207 is in the off state. Since the power supply 117 circuit operates in conjunction with the contact unit 207, the circuit is in the open state, and the driving power to the liquid supply unit 121 is cut off (S304).

[0042] As explained using Figure 3, even if the water level sensor of the storage tank 201 malfunctions or there is some malfunction or processing delay in the control of the computer (control unit 110), the shut-off unit 115 is provided independently of the control unit 110, and the shut-off unit 115 directly cuts off the drive power to the mechanism related to the liquid supply unit 121, thereby reliably stopping the analysis operation and preventing waste liquid overflow.

[0043] In Example 1, a method was described in which, if the first detection unit 203 malfunctions or there is any malfunction or processing delay in the computer control, the shut-off unit 115 directly cuts off the drive power to the liquid supply unit 121 as a trigger when the second detection unit 204 detects a malfunction, thereby stopping the analysis operation. As a result, waste liquid will not flow into the storage tank 201, thus reliably preventing overflow of the storage tank 201. In Example 2, as a means of recovery after the above-mentioned malfunction occurs, a function to temporarily release the power cut-off control by the shut-off unit 115 is added, and an automatic discharge function to the waste liquid storage unit 104 and a discharge amount metering function are also added. As a result, the discharge amount to the waste liquid storage unit 104 can be continuously managed. The configuration of the automatic analyzer 100 is the same as in Example 1, so its description is omitted.

[0044] The configuration of Embodiment 2 will be explained using Figure 4. In Embodiment 1, a relay was provided in the interruption unit 115 to switch the output voltage, but in this embodiment, a comparator 403 is provided between the relay (consisting of a coil and a contact part 402) and the second detection unit. The output terminal of the second detection unit 204 is connected to the positive input of the comparator 403, and a reference voltage (Ref.) is applied to the negative input. By providing the comparator 403, the output value of the second detection unit 204 that interrupts the liquid supply unit 121 can be freely adjusted by changing the reference voltage (Ref.).

[0045] For example, when using a contact sensor (e.g., a sensor that utilizes the change in electrical resistance value when waste liquid touches the sensor) as the second detection unit, experimentally determine the current value flowing through the sensor when it is determined that the waste liquid has touched, and apply a voltage to the comparator 403 via a current-voltage conversion circuit (not shown. The simplest is a voltage divider using a resistor) such that a voltage corresponding to the current value is generated, thereby adjusting the sensitivity of the second detection unit 204. Also, even for an optical sensor (e.g., a combination of an LED and a photodiode), it is effective to employ the comparator 403 when sensitivity adjustment may be useful.

[0046] The contact part 402 is arranged in the path connecting the power supply 117 and the liquid feeding part 121. Since the output of the comparator 403 switches between ON / OFF according to the detection state of the second detection unit 204, it is possible to control the ON state and OFF state of the contact part 402 (also referred to as the "cut-off switch").

[0047] When the second detection unit 204 is in the light-receiving state, the comparator 403 determines that the potential difference between the input terminals has reached the threshold value and outputs a voltage of the High level (=1). As a result, the cut-off switch (contact part 402) is in the ON state, so the power supply circuit to the liquid feeding part 121 forms a closed loop and the driving power is energized. When the second detection unit 204 is in the light-blocking state, the comparator 403 determines that the potential difference between the input terminals has not reached the threshold value and outputs a voltage of the Low level (=0).

[0048] As a result, the cut-off switch (contact part 402) is in the OFF state, so the power supply circuit to the liquid feeding part 121 is in an open state and the driving power is cut off. Also, when using a contact sensor as the waste liquid detection means, the output signal of the sensor fluctuates depending on the composition of the organic solvent. To enable detection of waste liquid regardless of the composition of the organic solvent, it is necessary to add an amplifier circuit for amplifying a weak output voltage and set the threshold value of a voltage divider, etc.

[0049] In Example 1, when the second detection unit 204 was shielded from light, power supply to the liquid delivery unit 121 could not be resumed unless the operator manually drained the waste liquid from the storage tank 201. Furthermore, for safety reasons, the storage unit for storing organic solvents and patient samples is configured so that users cannot directly drain the contents manually. If the second detection unit 204 is shielded from light and the power supply 117 to the liquid delivery unit 121 is cut off, a service technician will need to remove the storage tank 201 and drain the waste liquid, resulting in a period of time when the automated analyzer cannot be operated.

[0050] In Embodiment 2, a new path is added connecting the liquid delivery unit 121 and the power supply 117, and a reset switch 401 is installed to control the opening and closing of this path. As a result, even if the power supply to the liquid delivery unit 121 is interrupted, the power supply interruption control by the interruption unit 115 is temporarily released by turning on the reset switch 401. Furthermore, the control unit 110 recognizes that the reset switch 401 is in the ON state and uses this as a trigger to open the solenoid valve 71 and perform the waste liquid discharge operation. This eliminates the need for manual discharge by a service technician and prevents delays in the operating time of the automatic analyzer 100.

[0051] When the second detection unit 204 detects something, the waste liquid discharge operation involves opening the solenoid valve 71, and closing the solenoid valve 71 after a predetermined time t2 has elapsed. After the waste liquid discharge operation is performed, the analysis operation is stopped until the reset switch 401 is switched to the off state, and a warning is output to inform the operator to switch the reset switch 401 to the off state. The computer displays alarm information on the display unit 112 and outputs an alarm sound. As an example of alarm information, a message such as "The reset switch 401 is in the ON state, please switch it to the OFF state." is displayed on the screen. The alarm may be displayed, an audible alarm, or other means.

[0052] Here, after the waste liquid discharge operation is performed, the reset switch 401 may be configured to automatically switch to the ON state. Switching the reset switch 401 is an emergency reset means in case the second detection unit 204 is in a light-shielded state. For this reason, a protective cover may be provided to prevent the user from directly accessing it during normal use, or a function may be provided to prevent the analysis operation from starting from a safety standpoint.

[0053] The structure of the reset switch 401 will now be described. The reset switch 401 is a single-contact switch and is located in the path connecting the power supply 117 and the fluid delivery unit 121. When the reset switch 401 is in the ON state, a closed loop is formed between the fluid delivery unit 121 and the power supply 117, so power is always supplied regardless of the output state of the comparator 403. When the reset switch 401 is in the OFF state, the path between the fluid delivery unit 121 and the power supply 117 is not connected, so the switching of the cutoff switch (contact part 402) is activated. For example, a key lock switch, toggle switch, or push-button switch can be used for the reset switch 401.

[0054] In Embodiment 2, a third detection unit 404 is provided to detect the minimum water level of the waste liquid stored in the storage tank 201, and it is determined whether the discharge operation was performed normally based on the detection signal from the third detection unit 404. The control unit 110 executes the discharge operation when the first detection unit 203 or the second detection unit 204 is in a light-shielding state, and checks the detection status of the third water level 405 after a predetermined time has elapsed. If the waste liquid water level is below the third water level 405, it is determined that there is an abnormality in the discharge operation, and an instruction to stop the analysis operation is issued. Possible causes of discharge abnormalities include the inclusion of foreign matter in the storage tank 201, blockage in the waste liquid flow path, and failure of the solenoid valve 71. In these cases, it is necessary for a service technician to clean the storage tank 201 or replace the storage tank 201 or the solenoid valve 71.

[0055] The control unit 110 counts up the amount of waste liquid discharged into the waste liquid storage unit 104 after each waste liquid discharge operation is performed. If the first detection unit 203 is detected, the amount of waste liquid corresponding to the first water level 205 is measured as having been discharged. If the second detection unit 204 is detected, the amount of waste liquid corresponding to the second water level 206 is measured as having been discharged. The total amount of waste liquid discharged into the waste liquid storage unit 104, Vr, is calculated by the following formula.

[0056] Vr = Vo - Vi ... (Equation 2) Here, Vo is the current remaining amount in the waste liquid storage unit 104, and Vi is the amount of waste liquid corresponding to each detection unit. Note that when i=1, the first detection unit 203 is the relevant unit, and when i=2, the second detection unit 204 is the relevant unit.

[0057] By counting the amount of liquid discharged from the storage tank 201, the remaining amount in the waste liquid storage unit 104 can be continuously monitored even when the above-mentioned control malfunction occurs, thereby reliably preventing the waste liquid tank from overflowing.

[0058] When the computer recovers from a control malfunction, the detection signal from the first detection unit 203 becomes recognizable by the control unit 110. However, if the first detection unit 203 malfunctions, the control unit 110 will remain unable to recognize the detection signal from the first detection unit 203. Therefore, at the moment the reset switch 401 is switched to the ON state, the control unit 110 checks the detection signal from the first detection unit 203 and determines whether or not the first detection unit 203 is malfunctioning. If the first detection unit 203 is in a light-shielding state, it is determined that the first detection unit 203 is malfunctioning, and an instruction to stop the analysis operation and an alarm to indicate the malfunction of the first detection unit 203 are output.

[0059] The control unit 110 keeps the analysis operation stopped until the first detection unit 203 is in a light-shielding state, so that the device state will not change unless the sensor of the first detection unit 203 is replaced. In the event of a failure of the first detection unit 203, a service technician will need to replace the first detection unit 203.

[0060] A flowchart for monitoring waste liquid in Embodiment 2, which involves shutting off the power supply to the liquid supply unit 121 and calculating the amount of waste liquid discharged to the waste liquid storage unit 104, will be explained using Figure 5.

[0061] The control unit 110 determines whether the reset switch 401 is in the ON state. If the reset switch 401 is in the OFF state, the process proceeds to S502; if the reset switch 401 is in the ON state, the process proceeds to S513 (S501).

[0062] The control unit 110 determines whether the water level of the waste liquid stored in the storage tank 201 has reached the first water level 205. If the water level of the waste liquid has reached the first water level 205, the process proceeds to S503; otherwise, the process proceeds to S511 (S502).

[0063] The control unit 110 opens the solenoid valve 71 and discharges the waste liquid stored in the storage tank 201 to the waste liquid storage section 104 (S503).

[0064] The control unit 110 waits until a predetermined time t1 has elapsed. The predetermined time t1 is the time required for the waste liquid stored in the storage tank 201 to reach the first water level 205 and be discharged into the waste liquid storage unit 104, and is calculated by Equation 1 (S504).

[0065] The control unit 110 closes the solenoid valve 71. When the solenoid valve 71 is closed, waste liquid is stored in the storage tank 201 (S505).

[0066] The control unit 110 determines whether the water level of the waste liquid stored in the storage tank 201 is below the third water level 405. If the water level of the waste liquid is below the third water level 405, the process proceeds to S507; if it is at or above the third water level 405, the process proceeds to S509 (S506). Note that S505 and S506 are executed almost simultaneously.

[0067] The control unit 110 outputs an alarm indicating that an abnormality has occurred in the discharge operation (S507).

[0068] The control unit 110 issues a command to stop the analysis operation (S508).

[0069] The control unit 110 calculates the difference between the remaining amount in the waste liquid storage unit 104 and the amount of waste liquid corresponding to the first detection unit 203 as the total amount of waste liquid discharged to the waste liquid storage unit 104, Vr (S509).

[0070] Vr = Vo - V1 …(Equation 3) Here, Vo is the current remaining amount in the waste liquid storage section 104, and V1 is the amount of waste liquid corresponding to the first water level 205. The remaining capacity of the waste liquid storage section 104 calculated above is displayed on the display unit 112.

[0071] Since the storage tank 201 has reached its discharge capacity, an alarm is output indicating that the discharge operation has been performed (S510).

[0072] The shut-off unit 115 determines, based on the detection signal from the second detection unit 204, whether the water level of the waste liquid stored in the storage tank 201 is equal to or greater than the second water level 206. If the second detection unit 204 is in a light-shielding state, the shut-off switch (contact part 402) operates in the off state, and the process proceeds to S512. If the second detection unit 204 is in a light-receiving state, the shut-off switch (contact part 402) operates in the on state, the drive voltage is supplied, and the process returns to S502 (S511). Note that S502 and S511 are executed almost simultaneously.

[0073] When the shut-off switch (contact portion 402) is switched to the off state, the circuit of the shut-off portion 115 opens, and the power supply to the liquid supply portion 121 is cut off. The power supply to the liquid supply portion 121 remains cut off until the reset switch 401 is switched to the on state (S512).

[0074] The control unit 110 determines whether the water level of the waste liquid stored in the storage tank 201 has reached the first water level 205. If the water level of the waste liquid has reached the first water level 205, the process proceeds to S514; otherwise, the process proceeds to S515 (S513).

[0075] The control unit 110 opens the solenoid valve 71, and the waste liquid stored in the storage tank 201 is discharged to the waste liquid storage section 104 (S514).

[0076] The control unit 110 determines that the first detection unit 203 is malfunctioning and outputs an alarm prompting the replacement of the first detection unit 203 because it is malfunctioning (S515).

[0077] The control unit 110 issues a command to stop the analysis operation (S516).

[0078] The control unit 110 waits until a predetermined time t2 has elapsed (S517). The predetermined time t2 is the time required for the waste liquid stored in the storage tank 201 to reach the second water level 206 and to be discharged into the waste liquid storage unit 104, and can be calculated, for example, by the following formula.

[0079] t2 = L1 / U + tB ... (Equation 4) Here, L2 is the second water level 206, U is the flow velocity of the waste liquid flowing through the second channel 202, and tB is the buffer time.

[0080] The control unit 110 closes the solenoid valve 71. When the solenoid valve 71 is closed, waste liquid is stored in the storage tank 201 (S518).

[0081] The control unit 110 determines whether the water level of the waste liquid stored in the storage tank 201 is below the third water level 405. If the water level of the waste liquid is below the third water level 405, the process proceeds to S520; if it is at or above the third water level 405, the process proceeds to S522 (S519). Note that S518 and S519 are executed almost simultaneously.

[0082] The control unit 110 outputs an alarm indicating that an abnormality has occurred in the discharge operation (S520).

[0083] The control unit 110 issues an instruction to stop the analysis operation (S521).

[0084] The control unit 110 calculates the difference between the current remaining amount in the waste liquid storage unit 104 and the amount of waste liquid corresponding to the second detection unit 204 as the total amount of waste liquid discharged to the waste liquid storage unit 104, Vr (S522).

[0085] Vr = Vo - V2 …(Equation 5) Here, Vo is the current remaining amount in the waste liquid storage section 104, and V2 is the amount of waste liquid corresponding to the second water level 206. The remaining capacity of the waste liquid storage section 104 calculated above is displayed on the display unit 112.

[0086] The control unit 110 determines whether the reset switch 401 is in the ON state. If the reset switch 401 is in the ON state, the process proceeds to S524; if the reset switch 401 is in the OFF state, the process proceeds to S501 (S523).

[0087] The control unit 110 determines that the reset switch 401 is in the ON state and outputs an alarm prompting the system to switch the reset switch 401 to the OFF state (S524).

[0088] The control unit 110 issues a command to stop the analysis operation (S525).

[0089] In Example 1, the liquid supply unit 121 was configured to stop before the waste liquid overflowed from the storage tank 201. In Example 3, as shown in Figure 6, a waste liquid receiver 209 was provided on the outside of the storage tank 201, covering the bottom of the storage tank. The liquid supply unit 121 was configured to shut off when the waste liquid overflowing from the storage tank 201 touched a liquid contact sensor 210 located near the bottom of the waste liquid receiver 209. In this configuration, the liquid contact sensor 210 can be made of a simple metal rod, and the overflow of waste liquid can be detected by utilizing the change in electrical resistance or capacitance when the metal rod comes into contact with the waste liquid. In other words, there is an effect that the detection unit can be manufactured at a lower cost compared to the detection unit in Figure 2. The liquid contact sensor 210 may be placed on the upper side of the storage tank 201 instead of the bottom of the waste liquid receiver 209. Placing it on the upper side has the effect of detecting the occurrence of overflow earlier compared to placing it on the bottom.

[0090] In Example 1, the liquid delivery unit 121 was configured to stop before the waste liquid overflowed from the storage tank 201. In Example 4, as shown in Figure 7, a three-way valve was provided in the first flow path 211, so that the liquid delivery unit 121 was not stopped and the waste liquid flowing through the first flow path 211 was directly directed to the waste liquid storage unit. That is, when the light at the second detection unit is interrupted, the relay turns ON, and the three-way valve 212 is connected to the third flow path 213, so that the waste liquid flowing through the first flow path 211 flows through the third flow path 213 to the waste liquid storage unit 104 (the configuration for switching the three-way valve is called the "flow path switching unit"). This configuration has the disadvantage that the amount of waste liquid cannot be measured because the waste liquid flowing through the first flow path 211 after an overflow occurs does not pass through the storage tank 201, but on the other hand, it has the advantage that the risk of waste liquid overflowing into the analysis unit 102 can be reliably avoided by stopping the liquid delivery unit 121. The three-way valve 212 may be installed between the analysis unit 102 and the liquid delivery unit 121 in the first flow path 211, or between the liquid delivery unit 121 and the storage tank 201. The latter is preferable because it allows the liquid delivery unit 121 to reliably deliver the waste liquid to the waste liquid storage unit 104.

[0091] In Example 5, a capacitive sensor 242 was used to detect wastewater instead of the optical sensor used in Example 1. Figure 8 is a schematic diagram of the area around the storage section in Example 5. The first capacitive sensor 242 extends along the outer side wall of the storage tank 201 and consists of self-capacitive transmitting and receiving electrodes. The amount of wastewater in the storage tank 201 is measured by utilizing the fact that the capacitance between the transmitting and receiving electrodes and GND changes depending on the amount of wastewater in the storage tank 201. The change in capacitance is measured by the capacitance measuring unit 240. By using the first capacitive sensor 242, it is possible to measure the amount of wastewater even when the liquid level of the wastewater in the storage tank 201 is between the first water level 205 and the second water level 206. When using the optical sensor described in Example 1, if any trouble occurs, it is not possible to check the amount of wastewater remaining in the storage tank 201, but by using the first capacitive sensor 242 in Example 5, it is possible to check the amount of wastewater remaining. Furthermore, by opening solenoid valve 222 or solenoid valve 223 to transfer the waste liquid in storage tank 201 to waste liquid tank 250 or 251, the decrease in the amount of waste liquid in storage tank 201 can be monitored, allowing for monitoring of the waste liquid discharge time and discharge rate per unit time (ml / sec). This enables the system to notify alarms, for example, if the discharge time is extremely long or if the discharge rate per unit time decreases, prompting a warning that some kind of malfunction may have occurred and prompting inspection. Additionally, the amount of waste liquid can be accumulated once the discharge of waste liquid from storage tank 201 is complete.

[0092] Furthermore, in Figure 8, the waste liquid storage section 104, which was one in Embodiment 1, has been replaced with two waste liquid tanks 250 and 251. With this structure, when the device is first put into use, the solenoid valve 222 is opened and the solenoid valve 223 is closed to discharge waste liquid only into waste liquid tank 250. When waste liquid tank 250 is full, the solenoid valve 222 is closed and the solenoid valve 223 is opened to discharge waste liquid into waste liquid tank 251. While the waste liquid tank 250 is being discharged into waste liquid tank 251, it is possible to remove the waste liquid tank 250 from the device and transfer the waste liquid inside it to another waste liquid tank. In addition, the liquid transfer section 121 (liquid transfer pump) has been replaced with a solenoid valve 221. Replacing it with a solenoid valve makes it possible to reduce the device cost. Solenoid valves 221, 222, and 223 are controlled by the solenoid valve control unit 220.

[0093] Figure 9 shows a schematic diagram of the area around the storage tank in Example 6. In Example 6, a second storage tank 260 is provided upstream of the solenoid valve 221 of Example 5. The second storage tank 260 controls the inflow of waste liquid into the storage tank 201, enabling accurate measurement and waste liquid volume management in the storage tank 201. The second storage tank 260 is also provided with a second capacitive sensor 241, similar to the storage tank 201, and the change in capacitance is measured by the capacitance measurement unit 240. When the second capacitive sensor 241 detects that the amount of waste liquid in the second storage tank 260 has reached a predetermined amount, the solenoid valve 221 is opened to allow the waste liquid in the second storage tank 260 to flow into the storage tank 201. Furthermore, since the second storage tank 260 does not require measurement of the time-dependent change in the amount of waste liquid in the second storage tank 260, as does the storage tank 201, a lower-cost optical sensor, as used in Example 1, may be used instead of the second capacitive sensor 241.

[0094] Figure 10 shows the operation flow of the storage tank in Example 6. The metering operation of the waste liquid generated in the analysis unit 102 that flows into the second storage tank 260 is started (step S401). When the second capacitive sensor 241 detects that the amount of waste liquid in the second storage tank 260 has reached a preset amount, the solenoid valve 221 is opened and the waste liquid in the second storage tank 260 is discharged (step S402). The second capacitive sensor 241 is used to confirm that the amount of waste liquid in the second storage tank 260 has become zero (step S403). The operation of the storage tank 201 is performed in parallel with these steps S401 to S403. First, the amount of waste liquid in the storage tank 201 is measured using the first capacitive sensor 242 (step S411). When the first capacitive sensor 242 detects that the amount of waste liquid in the storage tank 201 has reached the first water level 205, the solenoid valve 222 or solenoid valve 223 is opened to start the discharge operation of the waste liquid in the storage tank 201 (step S412). The first capacitive sensor 242 is used to confirm that the amount of waste liquid in the storage tank 201 has become zero (step S413). When the automatic analyzer starts up, only steps S401 to S403 are performed, but after step S403, when waste liquid flows into the storage tank 201, steps S401 to S403 and steps S411 to S413 proceed simultaneously.

[0095] Figure 11 shows a flowchart that provides a more detailed explanation of the flow shown in Figure 10. First, the second capacitive sensor 241 is used to check whether there is waste liquid in the second storage tank 260 (step S501). If there is no waste liquid (if the answer is No in step S501), the process returns to the beginning. If there is waste liquid in the second storage tank 260 (if the answer is Yes in step S501), the process checks whether the storage tank 201 is in standby mode (step S502). If the storage tank 201 is not in standby mode (if the answer is No in step S502), the process returns to the beginning. Note that if the storage tank 201 is not in standby mode, it means, for example, that the discharge operations in S411 to S413 are being performed. If the storage tank 201 is in standby mode (if the answer is Yes in step S502), the remaining amount in the waste liquid tank 250 or 251 is then checked (step S503). The remaining amount in waste liquid tank 250 or 251 is checked by determining whether the remaining amount, measured by the number of times waste liquid has been discharged from the storage tank 201 to the waste liquid containment section 104 (or waste liquid tanks 250 and 251 in the case of Example 6), is within a predetermined amount, as described in Example 1.

[0096] Next, open the solenoid valve 222 or 223 (step S504). Next, check if the liquid level in the storage tank 201 exceeds the first water level 205 (step S505). If the answer in step S505 is No, return to the step before S505. If the answer in step S505 is Yes, close the solenoid valve 222 or 223 (step S506).

[0097] Next, the flowchart in Figure 12 will explain the confirmation flow for checking whether there are any abnormalities in the storage tank, etc. First, the amount of waste liquid in the storage tank 201 is confirmed using the first capacitive sensor 242 (step S601). Next, the solenoid valve 222 or 223 is opened (step S604). Measurement of the waste liquid discharge time from the storage tank 201 is started (step S603). It is confirmed whether there is any waste liquid in the storage tank (step S604). If there is no waste liquid in the storage tank 201 (if the answer is YES in step S604), the waste liquid discharge time from the storage tank 201 is calculated based on the time when it was determined that there was no waste liquid in the storage tank 201, and the discharge time measurement is ended (step S607). After that, the solenoid valve 222 or 223 is closed and the measurement is ended.

[0098] If it is determined in step S604 that there is waste liquid in the storage tank 201 (if the answer is No in step S604), the output of the first capacitive sensor 242 is used to determine whether there has been a change in the amount of waste liquid in the storage tank 201 (step S605). If there has been a change in the amount of waste liquid in the storage tank 201 (if the answer is Yes in step S605), the process returns to the step before S604. If there has been no change in the amount of waste liquid in the storage tank 201 (if the answer is No in step S605), the user is notified of this, and the automatic analyzer is stopped (step S606). The process then proceeds to step S607.

[0099] Figure 13 is a flowchart showing the flow for checking whether there is available capacity in the waste liquid storage section 104 (in the case of Example 6, the waste liquid tanks 250 and 251) at step S503 of the flowchart in Figure 11. As explained earlier, the remaining amount, measured by how many times waste liquid has been discharged from the storage tank 201 to the waste liquid storage section 104 (in the case of Example 6, the waste liquid tanks 250 and 251), is checked to see if it is within a predetermined amount (step S801). If there is no available capacity (if No at step S801), the destination of the waste liquid discharge is changed. That is, if the waste liquid tank 250 is currently in use, the destination of the waste liquid discharge is changed to the waste liquid tank 251, and if the waste liquid tank 251 is currently in use, the destination of the waste liquid discharge is changed to the waste liquid tank 250. If Yes at step S801 (if there is available capacity in the waste liquid tank), this flow is terminated.

[0100] 71: Solenoid valve, 100: Automatic analyzer, 101: Pre-processing unit, 102: Analysis unit, 103: Storage unit, 104: Waste liquid storage unit, 105: Waste liquid port, 106: Flow path, 107: Sample container, 108: Reagent container, 109: Memory unit, 110: Control unit, 111: Operation unit, 112: Display unit, 113: Sample dispensing unit, 114: Transport path, 115: Shut-off unit, 116: Reaction vessel, 117: Power supply, 118: First reaction vessel transport unit, 119: Opening, 120: Reaction disk, 121: Liquid delivery unit, 122: Reagent disk, 123: Reagent dispensing unit, 124: Magnetic separation unit, 125: Second reaction vessel transport unit, 127: Separation unit, 131 : Evaporation and concentration unit, 132: Third reaction vessel transport unit, 133: Concentrated liquid dispensing unit, 201: Storage tank, 202: Second flow path, 203: First detection unit, 204: Second detection unit, 205: First water level, 206: Second water level, 207: Contact unit, 208: Coil, 209: Waste liquid receiver, 210: Liquid contact sensor, 211: First flow path, 212: Three-way valve, 213: Third flow path, 220: Solenoid valve control unit, 221: Solenoid valve, 222: Solenoid valve, 223: Solenoid valve, 240: Capacitance measurement unit, 241: Second capacitive sensor, 242: First capacitive sensor, 250: Waste liquid tank, 251: Waste liquid tank, 401 402: Reset switch, 403: Contact part, 404: Comparator, 405: Third detection part, 406: Third water level.

Claims

1. An automatic analyzer comprising: an analysis unit for analyzing a sample; a storage unit connected to the analysis unit via a first flow path for temporarily storing waste liquid generated from the analysis unit; a waste liquid storage unit connected to the storage unit via a second flow path for storing the waste liquid stored in the storage unit; a first detection unit for detecting when the waste liquid stored in the storage unit reaches a first water level; a second detection unit for detecting when the waste liquid stored in the storage unit reaches a second water level higher than the first water level; a control unit for controlling the opening of a second valve provided in the second flow path when the first detection unit detects a change; and a shut-off unit for controlling the closing of a first valve provided in the first flow path when the second detection unit detects a change.

2. An automatic analyzer according to claim 1, wherein the first valve is a liquid pump, and the shut-off unit shuts off the power supply for driving the liquid pump, thereby stopping the liquid pump and closing the first valve.

3. An automatic analyzer according to claim 1, characterized in that the second detection unit is connected to the shut-off unit without going through the control unit.

4. An automatic analyzer according to claim 1, characterized in that it is further equipped with an analysis unit power cut-off unit that cuts off the power supply to the analysis unit when the second detection unit detects something.

5. An automatic analyzer according to claim 4, wherein the power supply cutoff unit for the analyzer unit cuts off the power supply to the analyzer unit after a predetermined time has elapsed from the time the second detection unit detects the state.

6. An automatic analyzer according to claim 4, characterized in that the cutoff unit also serves as the power cutoff unit for the analyzer unit.

7. An automatic analyzer according to claim 2, comprising a second electrical circuit connecting the liquid delivery pump and the power supply, and a reset switch for opening and closing the second electrical circuit, wherein when the supply of power to the liquid delivery pump is interrupted by the interruption unit, the reset switch is operated to close the second electrical circuit and restart the supply of power to the liquid delivery pump.

8. An automatic analyzer according to claim 7, wherein the control unit controls the opening of the first valve as a trigger when the reset switch is in the ON state.

9. An automatic analyzer according to claim 8, wherein the storage unit includes a third detection unit that detects a third water level which is lower than the first water level, and the control unit determines, based on the detection signal from the third detection unit, whether or not the waste liquid discharge operation from the storage unit has been performed normally after opening the first valve, and calculates a volume corresponding to the first water level or the second water level as the amount of waste liquid that has flowed into the waste liquid storage unit.

10. An automatic analyzer according to claim 8, wherein the control unit has a function to check the detection status of the first detection unit as a trigger when the reset switch is in the ON state, and to determine that the first detection unit is malfunctioning if the first detection unit is not detecting anything.

11. An analysis unit for performing analysis of a sample; a storage unit connected to the analysis unit via a first flow path for temporarily storing waste liquid generated from the analysis unit; a waste liquid storage unit connected to the storage unit via a second flow path for storing the waste liquid stored in the storage unit; a three-way valve provided in the first flow path for branching the flow of waste liquid generated from the analysis unit to either the storage unit or the waste liquid storage unit; a first detection unit for detecting when the waste liquid stored in the storage unit reaches a first water level; a second detection unit for detecting when the waste liquid stored in the storage unit reaches a second water level higher than the first water level; and a control unit for controlling the opening of a second valve provided in the second flow path when the first detection unit detects a problem. An automatic analyzer characterized by comprising a flow path switching unit that, when the second detection unit detects something, switches the three-way valve, which was branched to send waste liquid to the storage unit, to send the waste liquid to the waste liquid containment unit.

12. An automatic analyzer according to claim 1, characterized in that the first detection unit and the second detection unit are composed of a single capacitive sensor.

13. An automatic analyzer according to claim 1, wherein a second storage section is provided upstream of the first valve in the first flow path, and the second storage section is equipped with a measuring section for measuring the amount of waste liquid stored in the second storage section.

14. An automatic analyzer according to claim 13, characterized in that when the second detection unit detects that the waste liquid stored in the storage unit has reached the second water level, the control unit closes the first valve and opens the second valve to discharge the waste liquid in the storage unit to the waste liquid storage unit, and when the first detection unit detects that the waste liquid stored in the storage unit has reached the first water level, the control unit controls the second valve to close and stop the discharge of the waste liquid in the storage unit to the waste liquid storage unit.

15. An automatic analyzer according to claim 14, characterized in that the control unit determines that an abnormality has occurred if the time required for the waste liquid stored in the storage unit to rise from the second water level to the first water level is longer than a predetermined time.

16. An automatic analyzer according to claim 1, characterized in that two waste liquid storage units are connected to the storage unit via solenoid valves.

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