JP2010085274A - Automatic analysis apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic analysis apparatus capable of obtaining normal analysis results without lowering a specimen analysis processability. <P>SOLUTION: The automatic analysis apparatus includes a bubble generation decision unit 12 for detecting an electrical signal change caused by a contact with a specimen La in a specimen vessel 11a before an analysis and determining generation of bubbles on the liquid surface of the specimen La based on a degree of the signal change and a control unit 31 for controlling the analysis of the specimen La having the liquid surface which has been determined to have no generation of bubbles by the bubble generation decision unit 12. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an automatic analyzer that analyzes a sample by dispensing a sample and a reagent into a reaction vessel and measuring the absorbance of a reaction solution generated in the reaction vessel.

  2. Description of the Related Art Conventionally, an automatic analyzer that analyzes a specimen by dispensing a specimen and a reagent into a reaction container and measuring the absorbance of a reaction solution generated in the reaction container is known. This automatic analyzer includes a dispensing device realized by a dispensing nozzle, a dispensing pump, or the like in order to dispense a sample or a reagent.

  When dispensing liquids such as specimens or reagents, this dispensing device sucks a specified amount of liquid or avoids contamination caused by excessive penetration of the dispensing nozzle into the liquid. A liquid level detection device for detecting the liquid level of the liquid contained in the container is provided.

  As this liquid level detection device, for example, a light beam generation unit and a sensor unit that receives the reflected light beam are provided, and the sensor unit is determined from the time when the light beam generation unit irradiates the liquid surface with the light beam. There is known a liquid level detection device that detects the liquid level by calculating the height of the liquid level based on the time difference obtained by subtracting the time when the reflected light beam reflected by the liquid level is received (patent) Reference 1).

  However, in the liquid level detection device described in Patent Document 1, when a bubble is generated above the liquid level of the liquid contained in the container, the light beam is reflected by the bubble, so that the liquid level is incorrectly set. In some cases, bubbles were mistakenly detected as the liquid level. In this case, since the dispensing device sucks bubbles and air into the dispensing nozzle, there is a problem in that it cannot suck a specified amount of liquid and cannot perform an accurate dispensing process.

  Therefore, liquid level detection that distinguishes between the liquid level of the liquid and bubbles generated above the liquid level based on the change in the conductivity or capacitance of the liquid using an electrode formed of a conductive material and a dispensing nozzle. An apparatus is known (see Patent Document 2). According to this liquid level detection device, since the bubbles can be distinguished, an accurate dispensing process can be performed and a normal analysis result can be obtained.

Japanese Patent Laid-Open No. 2005-221392 JP 2008-026222 A

  However, in the liquid level detection device described in Patent Document 2, when the liquid contained in the container is sucked, the dispensing nozzle penetrates the bubbles and enters the liquid, so that the outer surface of the dispensing nozzle or the inside of the dispensing nozzle There was a risk that bubbles would adhere to portions of the side surface that were not cleaned by a normal cleaning process, resulting in contamination. In order to prevent contamination due to the adhesion of bubbles, it is sufficient to remove the bubbles from the dispensing nozzle. However, since the bubbles cannot be removed by the normal washing process, the analysis operation is stopped while the bubbles are removed. There was a problem that the processing capacity of the analysis was reduced.

  The present invention has been made in view of the above, and an object of the present invention is to provide an automatic analyzer that can obtain a normal analysis result without degrading the analysis processing capability.

  In order to solve the above-described problems and achieve the object, an automatic analyzer according to the present invention dispenses a specimen contained in a specimen container and a reagent contained in the reagent container into a reaction container, and the reaction container In an automatic analyzer that analyzes the components of the sample by measuring the absorbance of the reaction solution that has reacted with the sample and the reagent in the chamber, electrical contact is caused by contact with the sample in the sample container before analysis. A bubble generation determination unit that detects a signal change and determines whether or not a bubble is generated on the liquid surface of the sample based on a change amount of the signal change, and the bubble generation determination unit has no bubble generation. Control means for performing control to execute analysis of the specimen having the determined liquid level.

  In the automatic analyzer according to the present invention, in the above invention, the bubble generation determination unit may be configured such that the reagent corresponding to the analysis item of the sample that is sequentially received is dispensed into the reaction container. It is characterized by determining whether or not bubbles are generated on the liquid surface of the specimen.

  In the automatic analyzer according to the present invention, in the above invention, the bubble generation determination means is provided in the first and second portions, which are provided apart from each other and can be brought into contact with the sample stored in the sample container. Output from the first electrode via the second electrode, the oscillation circuit connected to the second electrode and generating a signal of a predetermined frequency, the oscillation circuit, the second electrode, and the specimen A change in the output voltage is detected, and the change amount of the output voltage is compared with the first and second reference voltages different from each other to determine whether bubbles are generated on the liquid surface of the specimen. And a determination unit.

  In the automatic analyzer according to the present invention, in the above invention, the bubble generation determination means includes a first electrode that can contact the sample housed in the sample container and the sample container, or A second electrode provided in the vicinity of the sample container; an oscillation circuit for generating a signal having a predetermined frequency; and supplying the generated signal to at least the first electrode; the first electrode and the oscillation circuit; Resulting from a change in capacitance between the first electrode and the second electrode caused by contact of the first electrode with the specimen By detecting the difference in output voltage from both ends of the resistor and comparing the difference between the output voltage and the first and second reference voltages different from each other, bubbles are generated on the liquid surface of the specimen. A determination unit for determining whether or not And wherein the Rukoto.

  According to the present invention, it is determined whether or not bubbles are generated on the liquid surface of the sample stored in the sample container before analysis, and the analysis of the sample having the liquid surface determined to be free of bubbles is performed. Because it is running, analysis is not performed on specimens with bubbles on the liquid surface. Therefore, it is possible to prevent a decrease in the processing capacity of the analysis process accompanying the bubble removal process. In addition, since abnormal analysis due to the generation of bubbles on the liquid surface of the sample does not occur, a normal analysis result can be obtained.

  Hereinafter, preferred embodiments of an automatic analyzer according to the present invention will be described in detail with reference to the drawings. The invention is not limited to the embodiments. In the description of the drawings, the same parts are denoted by the same reference numerals.

(Embodiment 1)
FIG. 1 is a schematic diagram showing a schematic configuration of the automatic analyzer according to the first embodiment. As shown in FIG. 1, the automatic analyzer 1 according to the first embodiment dispenses a first reagent, a specimen, and a second reagent into a reaction container 22 and reacts them in the reaction container 22, and the reaction solution A measurement mechanism 2 that measures the absorbance, and a control mechanism 3 that controls the entire automatic analyzer 1 including the measurement mechanism 2 and analyzes the measurement result in the measurement mechanism 2 are provided. The automatic analyzer 1 automatically analyzes a plurality of specimens by the cooperation of these two mechanisms.

  First, the measurement mechanism 2 will be described. As shown in FIG. 1, the measurement mechanism 2 includes a sample transport mechanism 11 that sequentially transports a sample rack 11b holding a plurality of sample containers 11a containing a sample such as blood or urine, in the direction of the arrow in the figure. Then, an electrical signal change due to contact with the specimen in the specimen container 11a before being dispensed into the reaction container 22 is detected, and whether or not bubbles are generated on the liquid surface of the specimen based on the change amount of the signal change. The bubble generation determination unit 12 for determining whether or not, the cleaning unit 12a for cleaning the portion that has contacted the sample in the bubble generation determination unit 12, and the sample is aspirated from the sample container 11a of the sample transfer mechanism 11 and the sample in the reaction container 22 A sample dispensing mechanism 13 for dispensing by dispensing the reaction container 22, a reaction tank 14 for transporting the reaction container 22 to a predetermined position in order to perform dispensing, stirring, photometry, and washing of the sample or reagent to the reaction container 22, And dispensed into the reaction vessel 22 A first reagent container 15 containing a plurality of reagent containers 15a containing one reagent, and a first reagent drawn from the reagent container 15a in the first reagent container 15 and discharged into the reaction container 22 A first reagent dispensing mechanism 16 for pouring, a second reagent container 17 for storing a plurality of reagent containers 17 a for storing second reagents to be dispensed in the reaction container 22, and reagents in the second reagent container 17 A second reagent dispensing mechanism 18 that sucks the second reagent from the container 17a and discharges the second reagent into the reaction container 22 to perform dispensing, and a stirring unit 19 that stirs the liquid dispensed into the reaction container 22. The photometric unit 20 that measures the absorbance of the liquid dispensed in the reaction vessel 22 and the cleaning unit 21 that cleans the reaction vessel 22 that has been measured by the photometric unit 20 are provided.

  Each of the sample containers 11a and the sample racks 11b is affixed with an information code recording medium in which identification information for identifying the sample accommodated therein is encoded and recorded in an information code such as a barcode or a two-dimensional code (see FIG. Not shown). Similarly, each of the reagent container 15a and the reagent container 17a is affixed with an information code recording medium in which identification information for identifying the reagent contained therein is encoded and recorded in an information code such as a barcode or a two-dimensional code. (Not shown). Therefore, the measurement mechanism 2 includes a sample container reading unit 11c that reads an information code attached to the sample container 11a and the sample rack 11b, a reagent container reading unit 15b that reads an information code attached to the reagent container 15a, and a reagent A reagent container reading unit 17b that reads an information code attached to the container 17a is provided.

  Next, the control mechanism 3 will be described. The control mechanism 3 includes a control unit 31, an input unit 32, an analysis unit 33, a storage unit 34, an output unit 35, and a transmission / reception unit 36. These units included in the measurement mechanism 2 and the control mechanism 3 are connected to the control unit 31.

  The control unit 31 is realized by a CPU or the like, and controls processing and operation of each unit of the automatic analyzer 1. The control unit 31 performs predetermined input / output control on information input / output to / from each of these components, and performs predetermined information processing on this information. The control unit 31 controls the dispensing operation of the specimen and the reagent based on the processing information stored in the storage unit 34.

  The input unit 32 is realized by a keyboard, a mouse, a touch panel having an input / output function, and the like, and acquires various information necessary for analyzing a sample, instruction information for analysis operation, and the like from the outside. The input unit 32 acquires and transmits instruction information to the control unit 31 via a communication network (not shown).

  The analysis unit 33 performs component analysis of the specimen based on the measurement result of the absorbance measured by the photometry unit 20.

  The storage unit 34 is realized by using a hard disk that stores information magnetically and a memory that electrically loads various programs related to this process from the hard disk when the automatic analyzer 1 executes the process. Various information including the analysis result of the specimen is stored. In addition, when the bubble generation determination unit 12 determines that bubbles are generated on the liquid surface of the sample, the storage unit 34 adds the bubbles to the processing information of the analysis processing of the sample and stores the information. The storage unit 34 may include an auxiliary storage device that can read information stored in a storage medium such as a CD-ROM, a DVD-ROM, or a PC card.

  The output unit 35 is realized by a display, a printer, a speaker, and the like, and outputs various information including the analysis result of the sample.

  The transmission / reception unit 36 has a function as an interface for transmitting / receiving information according to a predetermined format via a communication network (not shown).

  In the automatic analyzer 1 configured as described above, after the first reagent dispensing mechanism 16 dispenses the first reagent in the reagent container 15a with respect to the plurality of reaction containers 22 sequentially conveyed in a row. The sample dispensing mechanism 13 dispenses the sample in the sample container 11a, and the second reagent dispensing mechanism 18 dispenses the second reagent in the reagent container 17a. Furthermore, the photometry unit 20 measures the absorbance of the reaction solution in a state in which the first reagent, the sample, and the second reagent are reacted, and the analysis unit 33 analyzes the measurement result to automatically analyze the component of the sample. Done. In addition, the cleaning unit 21 cleans the reaction vessel 22 being transported after the measurement by the photometry unit 20 is completed, and reuses the reaction vessel 22. Thereafter, the washed reaction vessel 22 is reused to perform a plurality of analysis processes.

  Here, the bubble generation determination unit 12 will be described in more detail. The bubble generation determination unit 12 is provided at a position that passes before the sample dispensing mechanism 13 during the transfer of the sample rack 11b in the sample transfer mechanism 11, and accommodates the sample before being dispensed by the sample dispensing mechanism 13. The presence or absence of generation of bubbles on the liquid surface of the sample container 11a is determined. Further, the timing at which the bubble generation determination unit 12 performs the bubble generation determination process is higher than the timing at which the first reagent corresponding to the analysis item of the determination target sample is dispensed into the reaction container 22 by the first reagent dispensing mechanism 16. It is before.

  FIG. 2 is a schematic diagram showing a schematic configuration of the bubble generation determination unit 12 used in the embodiment of the present invention. The bubble generation determination unit 12 detects the liquid level of the specimen by detecting that the two electrodes are brought into conduction through the specimen when they come into contact with the specimen in the specimen container. In addition, the specimen in Embodiment 1 of this invention shall have electroconductivity.

  The bubble generation determination unit 12 is made of a conductive material such as metal, and is made of a rod-shaped electrode 41 (first electrode) that contacts the sample La accommodated in the sample container 11a, and a conductive material similar to the electrode 41. A rod-shaped electrode 42 (second electrode) which is provided in the vicinity of the electrode 41 and spaced from the electrode 41 and can be interlocked with the electrode 41 without changing the relative position with the electrode 41, and the electrode 41 and the electrode 42 is connected to the arm 43 to which the arm 42 is attached, the drive unit 45 that moves the arm 43 by performing the vertical movement operation and the horizontal rotation operation via the connecting portion 44, and the electrode 42, and has a predetermined frequency. The oscillation circuit 46 that generates the AC signal and the determination unit 47 that determines whether or not bubbles are generated on the liquid surface of the specimen La according to the conduction state of the electrode 41 are provided.

  The determination unit 47 is output from the electrode 41 when the electrode 41 and the electrode 42 are in contact with the sample La at the predetermined bubble determination position A, and the electrode 41 and the electrode 42 are brought into conduction through the contacted sample La. A comparison circuit 51 (first comparison circuit) and a comparison circuit 52 (second comparison circuit) that compare first and second reference voltages different from each other, and outputs from the comparison circuits 51 and 52, respectively. And a signal processing circuit 53 that performs predetermined signal processing.

FIG. 3 is a diagram illustrating a configuration of the comparison circuit 51. As shown in FIG. 3, the comparison circuit 51 is connected to the electrode 41 on the negative-phase terminal (−) side, and receives a comparator 511 that inputs the output voltage V from the electrode 41, and a positive-phase terminal (+ And a voltage dividing circuit 514 that divides a predetermined voltage V _ref by a resistor 512 and a resistor 513. The voltage dividing circuit 514 inputs a reference voltage V ₁ (> 0) that is a first reference voltage to the comparator 511. Further, the comparison circuit 52 has the same configuration as the comparison circuit 51. In the comparison circuit 52, the reference voltage V ₂ (> 0) as the _second reference voltage is input from the voltage dividing circuit connected to the positive phase terminal side. The values of the _two reference voltages V ₁ and V ₂ are different and satisfy V ₁ <V ₂ . The values of the reference voltages V ₁ and V ₂ are determined by adjusting the resistance values of the voltage dividing circuits included in the comparison circuits 51 and 52, respectively.

The determination unit 47 determines whether the electrode 41 is in contact with the liquid surface of the specimen La or whether the electrode 41 is in contact with bubbles generated above the liquid surface of the specimen La by using the reference voltages V ₁ and V _2. The determination result is output to the control unit 31. Specifically, when the electrode 41 comes into contact with the liquid surface of the specimen La, the tip of the electrode 41 is set so as to descend from the liquid surface by a predetermined amount and be rolled in as shown in FIG. For this reason, when the electrode 41 comes into contact with the liquid surface of the specimen La, the contact area between the electrode 41 and the specimen La increases accordingly. On the other hand, when the electrode 41 comes into contact with bubbles generated above the liquid surface of the specimen La, the surface of the bubble Bb is a thin film and the inside (the bubbles Bb and Bb Air or between the bubble Bb and the specimen La), the thin film-like specimen La only adheres to the tip of the electrode 41. As a result, the contact area between the electrode 41 and the specimen La is significantly smaller than when the electrode 41 is in contact with the liquid surface of the specimen La. The contact area between the electrode 42 and the specimen La can be said to be the same as the contact area between the electrode 41 and the specimen La.

The resistance value between the electrode 41 and the electrode 42 when the electrode 41 and the electrode 42 are brought into conduction by contact with the specimen La is the same as that when the electrode 41 and the liquid surface of the specimen La are in contact with each other. It turns out that it is smaller than the case where bubble Bb contacts. Therefore, the amplitude V ₀ of the output voltage V of the electrode 41 is larger when the electrode 41 and the liquid surface of the specimen La are in contact than when the electrode 41 and the bubble Bb are in contact. Therefore, the two reference voltages V ₁ and V ₂ are generated in the contact state between the electrode 41 and the specimen La, that is, whether the electrode 41 is in contact with the liquid surface of the specimen La or above the liquid surface of the specimen La. Whether or not it is in contact with the bubble Bb is set as a distinguishable value.

6 and 7 are diagrams showing the time change of the output voltage V of the electrode 41. FIG. In these figures, the horizontal axis indicates time t, and the vertical axis indicates the output voltage V from the electrode 41. In FIGS. 6 and 7, contact with the specimen La starts at time t ₁ . Shows the case.

FIG. 6 is a diagram showing a case where the electrode 41 is in contact with the liquid surface of the specimen La, and the amplitude V ₀ of the output voltage V after the contact is larger than the reference voltage V ₂ of the comparison circuit 52 (V ₀ > V). ₂ ). On the other hand, FIG. 7 is a diagram showing a case where the electrode 41 is in contact with the bubble Bb, and the amplitude V ₀ of the output voltage V after the contact is larger than the reference voltage V ₁ of the comparison circuit 51, and the comparison circuit. 52 is smaller than the reference voltage V ₂ (V ₂ > V ₀ > V ₁ ). 6 and 7 schematically show the case where a sine wave is supplied from the oscillation circuit 46, a rectangular wave may be supplied from the oscillation circuit 46. FIG.

The signal processing circuit 53 performs predetermined signal processing on the outputs from the comparison circuit 51 and the comparison circuit 52, thereby outputting a detection signal corresponding to the determination result to the control unit 31. Specifically, when the amplitude V ₀ of the output voltage V satisfies V ₀ > V ₂ , that is, when the time changes as shown in FIG. 6, the detection signal corresponding to the determination result “liquid level”. Is output to the control unit 31. When the amplitude V ₀ of the output voltage V satisfies V ₂ > V ₀ > V ₁ , that is, when the time changes as shown in FIG. 7, a detection signal corresponding to the determination result “bubble” is generated. Output to the control unit 31.

  Here, the bubble generation determination process performed by the automatic analyzer 1 will be described with reference to the flowchart shown in FIG. In the following, a series of processing when performing bubble generation determination processing for one specimen La will be described.

  First, the control unit 31 determines whether there is a newly accepted sample. Specifically, when the sample container 11a crosses the sample container reading unit 11c, information obtained by the sample container reading unit 11c reading information pasted on the sample container 11a is stored in the storage unit 34, or an operation is performed. Whether or not a new sample has been received is determined based on information input to the input unit 32 by the person. When it is determined that there is no newly received sample (step S101: No), the control unit 31 repeats the determination process of step S101. On the other hand, when the control unit 31 determines that there is a newly received sample (step S101: Yes), the control unit 31 drives the drive unit 45 to be dispensed into the reaction container 22 by the sample dispensing mechanism 13. The electrodes 41 and 42 are lowered with respect to the sample container 11a that is stationary at the bubble determination position A before the detection (step S102).

  Thereafter, the control unit 31 determines whether or not a detection signal is output from the determination unit 47 when the electrode 41 comes into contact with the liquid surface of the specimen (step S103). When the determination unit 47 outputs a detection signal (step S103: Yes), the control unit 31 stops the lowering of the electrode 41 on the assumption that it has contacted the liquid surface of the sample (step S104). On the other hand, when the determination part 47 does not output a detection signal (step S103: No), it transfers to step S102 and the control part 31 continues the fall of the electrode 41. FIG.

  When the detection signal output by the determination unit 47 is a detection signal corresponding to the determination result “liquid level” (step S105: No), the process proceeds to step S107.

  On the other hand, when the detection signal output from the determination unit 47 is a detection signal corresponding to the determination result “bubble” (step S105: Yes), the control unit 31 performs the analysis process stored in the storage unit 34. The bubble generation information indicating that “bubbles” are generated is added to the processing information (step S106). FIG. 9 is a diagram showing a configuration of processing information. In the processing information table R1 shown in FIG. 9, the bubble generation information in the sample container 11a is described in addition to the information on the first and second reagents necessary for the analysis for each sample. For example, for the sample “1”, information that the reagents necessary for the analysis are the first reagent “a” and the second reagent “c”, and information that bubbles are not generated in the sample container 11a (×). Is described. For the sample “2”, information indicating that the sample is the first reagent “a” and the second reagent “c” and information indicating that bubbles are generated in the sample container 11a (◯) are described. The processing information table R1 may be displayed and output by the output unit 35.

  Then, the control part 31 drives the drive part 45, transfers the electrode 41 to the washing | cleaning part 12a, performs washing | cleaning (step S107) of the electrode 41, and complete | finishes a series of processes.

  Here, an outline of the analysis processing executed by the automatic analyzer 1 based on the processing information table R1 shown in FIG. 9 will be described. While the control unit 31 refers to the processing information table R1, the control unit 31 performs control to execute the analysis processing of the samples “1”, “5”, and “6” in which bubbles are not generated on the liquid surface of the sample container 11a. Control is performed to exclude samples “2”, “3”, and “4” to which the bubble generation information is added from the analysis process.

  FIG. 10 is a diagram showing the state of the reaction tank 14 after the automatic analyzer 1 dispenses the sample and the first and second reagents based on the processing information table R1. Hereinafter, the liquid mixture accommodated in the reaction container 22 is specified by a set of (specimen, first reagent, second reagent). In addition, the dispensing process of the sample or the like to the reaction container 22 is performed clockwise on the reaction tank 14 in the order described in the processing information table R1. In FIG. 10, on the reaction tank 14, a reaction vessel 22 containing the mixed liquids (1, a, c), (5, a, c), (6, b, d) is adjacent to each other in the clockwise direction. Are lined up. On the other hand, each of them is accommodated in a reaction vessel 22 that is originally located between the reaction vessel 22 containing the mixed solution (1, a, c) and the reaction vessel 22 containing the mixed solution (5, a, c). Since the mixed liquids (2, a, c), (3, b, d), (4, b, d) to be performed are excluded from the analysis process due to the generation of bubbles in the sample container 11a, the reaction tank 14 Does not exist on top. In this way, the automatic analyzer 1 executes only the analysis operation for the sample in which bubbles are not generated on the liquid surface of the sample container 11a before analysis. Note that the sample that has been excluded from the analysis process due to the generation of bubbles is analyzed by being stored in the sample transfer mechanism 11 again after the operator removes the bubbles.

  In the first embodiment, the bubble generation determination unit 12 generates bubbles on the liquid surface of the sample La based on the change amount of the electrical signal change caused by the contact with the sample in the sample container 11a before the analysis. It is determined whether or not a sample having a liquid level determined to have no generation of bubbles is analyzed. Therefore, even when bubbles are generated on the liquid level of the sample La, the analysis of the sample La is not performed, and the analysis of the next sample is performed, so that bubbles are generated in the dispensing nozzle of the sample dispensing mechanism 13. Adhesion can be prevented. As a result, dispensing errors due to bubbles generated above the liquid surface of the specimen and special cleaning processing do not have to be performed, so that an increase in cleaning time can be suppressed and a decrease in analysis processing capability can be prevented. . Furthermore, since the reagent dispensing operation corresponding to the sample La in which bubbles are generated is not performed, waste of the reagent can be prevented.

(Embodiment 2)
Next, a second embodiment of the present invention will be described. In the first embodiment described above, the bubble generation determination unit 12 detects the liquid level of the sample in the sample container 11a by the conduction method. However, in the second embodiment of the present invention, the bubble generation determination unit is a capacitance. The liquid level for detection of the specimen container 11a is detected by the method.

  FIG. 11 is a schematic diagram illustrating a schematic configuration of the bubble generation determination unit according to the second embodiment. The bubble generation determination unit 60 shown in FIG. 11 is provided between a rod-shaped electrode 61 (first electrode) made of a conductive material and an electrode 67 (second electrode) provided in the vicinity of the sample container that contains the sample. The contact between the electrode and the liquid surface of the specimen is detected based on the change in the electrostatic capacity. In addition, in FIG. 11, about the site | part which has the same structure as the bubble generation | occurrence | production determination part 12 demonstrated in the said Embodiment 1, the same code | symbol is attached | subjected.

  The bubble generation determination unit 60 according to the second embodiment is made of a conductive material such as metal, and generates a rod-shaped electrode 61 that comes into contact with the sample La contained in the sample container 11a and an AC signal having a predetermined frequency. The oscillation circuit 62 for supplying the generated signal to the electrode 61, the resistor 63 interposed in series between the electrode 61 and the oscillation circuit 62, and the end of the resistor 63 connected to the oscillation circuit 62. The reference circuit 64 connected in parallel with the resistor 63 from the oscillation circuit 62 side to the end of the oscillation circuit 62, and the resistance from the electrode 61 side to the end of the resistor 63 that is connected to the electrode 61 63 in parallel with the reference circuit 64, and the difference between the output voltage of the reference circuit 64 and the output voltage of the voltage change circuit 65 is used to detect bubbles on the liquid surface of the sample La. A determination unit 66 for determining the presence or absence of occurrence, Comprises an electrode 67 provided in the vicinity of the specimen vessels 11a accommodating the La, the.

  The resistance value of the resistor 63 is set such that a sufficient difference is generated between the output of the reference circuit 64 and the output of the voltage change circuit 65 when the electrode 61 comes into contact with the liquid surface of the specimen La.

  The reference circuit 64 and the voltage change circuit 65 have the same configuration. Specifically, the reference circuit 64 and the voltage change circuit 65 include a rectifier and a smoothing capacitor, and output a DC signal to the determination unit 66.

  The determination unit 66 includes a differential amplifier 71 that performs differential amplification of the output voltage of the reference circuit 64 and the output voltage of the voltage change circuit 65, and first and second reference voltages that are different from each other in the output of the differential amplifier 71. A comparison circuit 72 (first comparison circuit) and a comparison circuit 73 (second comparison circuit) for comparing, respectively, and a signal processing circuit 74 for performing predetermined signal processing on outputs from the comparison circuits 72 and 73, Have. The positive phase terminal side of the differential amplifier 71 is connected to the reference circuit 64, and the negative phase terminal side of the differential amplifier 71 is connected to the voltage change circuit 65. According to the determination unit 66 having such a configuration, the difference between the output of the reference circuit 64 disposed in the previous stage of the resistor 63 and the output of the voltage change circuit 65 disposed in the subsequent stage of the resistor 63 is determined as the differential amplifier 71. Thus, even if the amount of the sample La is very small, a change in capacitance can be detected accurately, and highly accurate liquid level detection can be realized.

The configuration of comparison circuits 72 and 73 is the same as that of comparison circuit 51 in the first embodiment (see FIG. 3). The comparison circuit 72 inputs the output from the differential amplifier 71 to the negative phase terminal side, and compares the magnitude with the reference voltage ΔV ₁ (> 0) that is the first reference voltage input to the positive phase terminal side. . Further, the comparison circuit 73 inputs the output from the differential amplifier 71 to the negative phase terminal side, and compares it with the reference voltage ΔV ₂ (> 0) that is the second reference voltage input to the positive phase terminal side. Compare. The values of the reference voltage ΔV ₁ and the reference voltage ΔV ₂ are different and satisfy ΔV ₁ <ΔV ₂ . The values of the reference voltage ΔV ₁ and the reference voltage ΔV ₂ are determined by adjusting the resistance values of the voltage dividing circuits included in the comparison circuits 72 and 73, respectively.

The determination unit 66 uses the reference voltage ΔV ₁ and the reference voltage ΔV ₂ to determine whether the electrode 61 is in contact with the liquid surface of the specimen La or whether the electrode 61 is in contact with bubbles generated above the liquid surface of the specimen La. Determination is performed, and a detection signal corresponding to the determination result is output to the control unit 31. Specifically, when the electrode 61 is not in contact with the specimen La, the output of the reference circuit 64 and the output of the voltage change circuit 65 are substantially the same (hereinafter, this output voltage is referred to as V _air ). When the electrode 61 comes into contact with the specimen La, the electrostatic capacity between the electrode 61 and the electrode 67 increases, so that the output of the voltage change circuit 65 decreases and a voltage drop occurs. On the other hand, the output of the reference circuit 64 is almost constant regardless of the presence or absence of contact between the electrode 61 and the specimen La.

The capacitance change between the electrode 61 and the electrode 67 when the electrode 61 is in contact with the specimen La is such that the electrode 61 is above the liquid level of the specimen when the electrode 61 is in contact with the liquid surface of the specimen La. Greater than in contact with the resulting foam. Therefore, when the output voltage of the voltage changing circuit 65 after contact with the analyte La and V _La, the value of this V _La is better when the electrode 61 is in contact with the liquid surface of the specimen La is, the analyte La above the liquid surface It is smaller than when it comes into contact with the bubbles generated. The reference voltages ΔV ₁ and ΔV ₂ are the outputs from the differential amplifier 71 after the electrode 61 contacts the specimen La, that is, the voltage drop ΔV = V _air −V _La , and the contact between the electrode 61 and the specimen La. It is set as a value that can be discriminated according to the state, more specifically, whether it is in contact with the liquid surface of the specimen La or in contact with the bubble.

12 and 13 are diagrams showing the time change of the output voltage V of the voltage change circuit 65. FIG. In these figures, the horizontal axis indicates time t, and the vertical axis indicates the output voltage V of the voltage change circuit 65. Further, in FIG. 12 and FIG. 13 shows a case in which began contacting the analyte La time t _2.

FIG. 12 is a diagram illustrating a case where the electrode 61 is in contact with the liquid level of the specimen La. In this case, the output voltage V _La of the voltage change circuit 65 after contact is smaller than the output voltage V ₄ (= V _air −ΔV ₂ ) of the comparison circuit 73 when not in contact. That is, the output ΔV = V _air −V _La from the differential amplifier 71 after the contact is larger than ΔV ₂ = V _air −V ₄ (ΔV> ΔV ₂ ).

FIG. 13 is a diagram illustrating a case where the electrode 61 is in contact with bubbles generated above the liquid surface of the specimen La. In this case, the output voltage V _La after contact is smaller than the output voltage V ₃ (= V _air −ΔV ₁ ) of the comparison circuit 72 when not in contact, and the output voltage V ₄ (= V _air −ΔV ₂ ). That is, the output ΔV = V _air −V _La from the differential amplifier 71 after the contact is larger than ΔV ₁ = V _air −V _{3 and} smaller than ΔV ₂ = V _air −V ₄ (ΔV ₂ >ΔV>) ΔV ₁ ).

The signal processing circuit 74 outputs a detection signal corresponding to the determination result to the control unit 31 by performing predetermined signal processing on the outputs from the comparison circuits 72 and 73. Specifically, when the output voltage ΔV from the differential amplifier 71 satisfies ΔV> ΔV ₂ , that is, when the output voltage V of the voltage changing circuit 65 causes a voltage drop as shown in FIG. A detection signal corresponding to the determination result is output to the control unit 31. Further, when the output voltage ΔV from the differential amplifier 71 satisfies ΔV ₂ >ΔV> ΔV ₁ , that is, when the output voltage V of the voltage change circuit 65 causes a voltage drop as shown in FIG. A detection signal corresponding to the determination result is output to the control unit 31.

  In FIG. 11, the electrode 67 has a flat plate shape, but may have a shape other than the flat plate shape. For example, the electrode 67 may cover the sample container 11a. Further, the function of the electrode 67 may be provided by forming the specimen container 11a with a conductive material.

  The bubble generation determination process performed by the automatic analyzer including the bubble generation determination unit 60 configured as described above has the same process flow as the bubble generation determination process described in the first embodiment (see FIG. 8). reference).

  In the second embodiment, the bubble generation determination unit 60 generates bubbles on the liquid surface of the sample La based on the change amount of the electrical signal change caused by the contact with the sample in the sample container 11a before the analysis. It is determined whether or not a sample having a liquid level determined to have no generation of bubbles is analyzed. Therefore, even when bubbles are generated on the liquid level of the sample La, the analysis of the sample La is not performed, and the analysis of the next sample is performed, so that bubbles are generated in the dispensing nozzle of the sample dispensing mechanism 13. Adhesion can be prevented. As a result, dispensing errors due to bubbles generated above the liquid surface of the specimen and special cleaning processing do not have to be performed, so that an increase in cleaning time can be suppressed and a decrease in analysis processing capability can be prevented. . Furthermore, since the reagent dispensing operation corresponding to the sample La in which bubbles are generated is not performed, waste of the reagent can be prevented.

  In the first and second embodiments described above, it is determined whether or not bubbles are generated on the liquid surface of the sample in the sample container 11a before being dispensed into the reaction container 22, but this is not restrictive. It may be determined whether or not bubbles are generated on the liquid surface of the reagent in 15a. When the reagent container 15a is transported, the reagent inside the reagent container 15a is shaken and bubbles are easily generated. For this reason, in the conventional automatic analyzer, when the reagent container 15a is accommodated in the first reagent storage 15, it is necessary to check whether or not bubbles are generated, which is a burden on the operator. On the other hand, as shown in FIG. 14, after the bubble generation determination unit 23 is provided for the first reagent storage 15 and the reagent container 15a is accommodated in the first reagent storage 15, the bubble detection is automatically performed before the analysis. By making the setting to be performed manually, the burden on the operator is reduced and the analysis can be performed more efficiently. Similarly, it is also possible to provide the bubble generation determination unit 24 in the second reagent storage 17 to detect the liquid level of the reagent container 17a.

It is a schematic diagram which shows schematic structure of the automatic analyzer which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows schematic structure of the bubble generation | occurrence | production determination part with which the automatic analyzer which concerns on Embodiment 1 of this invention is provided. It is a figure which shows the structure of a comparison circuit. It is a figure which shows the state which the electrode contacted the liquid level of the test substance. It is a figure which shows the state which the electrode contacted the bubble produced above the liquid level of the test substance. It is a figure which shows the time change of the output voltage from an electrode when an electrode contacts the liquid level of a test substance. It is a figure which shows the time change of the output voltage from an electrode when an electrode contacts a bubble. It is a flowchart which shows the outline | summary of the bubble generation determination process which the bubble generation determination part of the automatic analyzer which concerns on Embodiment 1 of this invention performs. It is a figure which shows an example of the process information table of an analysis process. It is a figure which shows the state which performed dispensing operation | movement based on the process information table of an analysis process. It is a figure which shows typically the structure of the bubble generation | occurrence | production determination part with which the automatic analyzer which concerns on Embodiment 2 of this invention is provided. It is a figure which shows the time change of the output voltage of a voltage change circuit when an electrode contacts the liquid level of a test substance. It is a figure which shows the time change of the output voltage of a voltage change circuit when an electrode contacts a bubble. It is a schematic diagram which shows schematic structure of the automatic analyzer which concerns on the modification of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,100 Automatic analyzer 2 Measuring mechanism 3 Control mechanism 11 Specimen transfer mechanism 11a Specimen container 11b Specimen rack 11c Specimen container reading part 12, 23, 24, 60 Foam generation determination part 12a Washing part 13 Specimen dispensing mechanism 14 Reaction tank 15 1st reagent storage 15a, 17a Reagent container 15b, 17b Reagent container reading part 16 1st reagent dispensing mechanism 17 2nd reagent storage 18 2nd reagent dispensing mechanism 19 Stirring part 20 Photometry part 21 Washing part 22 Reaction container 31 Control part 32 input unit 33 analysis unit 34 storage unit 35 output unit 36 transmission / reception unit 41, 42, 61, 67 electrode 43 arm 44 connection unit 45 drive unit 46, 62 oscillation circuit 47, 66 determination unit 51, 52, 72, 73 comparison circuit 53, 74 Signal processing circuit 63, 512, 513 Resistor 64 Reference circuit 65 Voltage change circuit 71 Differential amplifier 51 Comparator 514 dividing circuit La analyte Bb foam R1 processing information table

Claims (4)

The sample contained in the sample container and the reagent contained in the reagent container are dispensed into a reaction container, and the absorbance of the reaction solution reacted with the sample and the reagent in the reaction container is measured. In an automatic analyzer that analyzes components,
A bubble that detects an electrical signal change due to contact with the sample in the sample container before analysis and determines whether or not bubbles are generated on the liquid surface of the sample based on the amount of change in the signal change Occurrence determination means;
Control means for performing control to perform analysis of the sample having a liquid level determined by the bubble generation determination means to be free of bubbles;
An automatic analyzer characterized by comprising:   The bubble generation determination means determines whether or not bubbles are generated on the liquid surface of the sample before the reagent corresponding to the analysis items of the sample sequentially received is dispensed into the reaction container. The automatic analyzer according to claim 1. The bubble generation determination means
First and second electrodes that are spaced apart from each other and are capable of contacting the specimen contained in the specimen container;
An oscillation circuit connected to the second electrode and generating a signal of a predetermined frequency;
A change in the output voltage output from the first electrode through the oscillation circuit, the second electrode, and the specimen is detected, and the amount of change in the output voltage is different from the first and second reference voltages that are different from each other. And a determination unit that determines whether or not bubbles are generated on the liquid surface of the specimen by comparing
The automatic analyzer according to claim 1, wherein the automatic analyzer is provided. The bubble generation determination means
A first electrode capable of contacting the sample contained in the sample container;
A second electrode provided integrally with or in the vicinity of the sample container;
An oscillation circuit for generating a signal having a predetermined frequency and supplying the generated signal to at least the first electrode;
A resistor connected in series between the first electrode and the oscillation circuit;
Detecting a difference in output voltage from both ends of the resistor due to a change in capacitance between the first electrode and the second electrode caused by the first electrode coming into contact with the specimen; A determination unit that determines whether or not bubbles are generated on the liquid surface of the specimen by comparing the difference between the output voltages and the first and second reference voltages different from each other;
The automatic analyzer according to claim 1, wherein the automatic analyzer is provided.

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