JP2007086035A - Liquid property determining device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To dispense with the need for shielding, when detecting bubbles, and to avoid the influence due to external noise. <P>SOLUTION: A bubble contamination determination part 21 of a dispensing device is constituted of a heater housing 31, having a liquid passage 35 for circulating a specimen 11, a heater 32, and a temperature sensor 33. The heater housing 31 is provided in the middle of an air tube 16 connected to a suction probe (not shown). The heater 32 and the temperature sensor 33 are provided between the liquid passage 35 and the outside surface of the housing 31. The heater 32 temperature is controlled so that the temperature of the specimen 11 circulating in the liquid passage 35 is kept constant, based on the temperature signal from the temperature sensor 33. The power consumption of the heater 32 is detected, and it is determined whether the air generating bubbles 29 is contaminated in the specimen 11. Hereby, shielding is not required, and there will not be possibility that the bubbles 29 are misdetected by being influenced by the external noise. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid property determination apparatus and method for determining the presence or absence of a change in the property of a distributed liquid.

  Biochemical analyzers are often used in medical institutions and the like as analyzers for analyzing the concentration of a specific biochemical substance contained in a sample such as blood or urine. This biochemical analyzer analyzes a sample by measuring a test chip on which a droplet of the sample is spotted. When spotting a sample such as blood or urine on a test chip, it is necessary to spot the sample without human intervention to prevent infection of the disease. Therefore, a dispensing device is incorporated in the biochemical analyzer.

  The dispensing device includes a syringe pump, a suction probe, an air tube, a probe moving mechanism, and the like. This dispensing apparatus sucks and collects a sample from a sample container using an aspiration probe, and deposits a predetermined amount of the sample collected by suction on each of a plurality of test chips. At this time, if air is sucked together with the specimen, bubbles are mixed in the specimen. When air bubbles are mixed, the amount of the sample that is spotted on the test chip decreases, and accurate analysis cannot be performed. Therefore, when the sample is aspirated, it is determined whether or not there is a change in the properties of the sample, such as whether or not bubbles are mixed. If bubbles are mixed, the sample is completely discharged, and then the sample is aspirated again. Is going.

As a specific determination method, as described in Patent Documents 1 and 2, there is known a method for determining the presence or absence of bubbles in a sample in an air tube using ultrasonic waves. In addition, as described in Patent Document 3, two coils are wound around an air tube, an excitation signal having a predetermined frequency is input to one coil, and a signal induced in the other coil is detected. A method for determining the presence or absence of bubbles in a specimen is also known. Further, as described in Patent Documents 4 and 5, the air tube is formed of a light-transmitting material, and the air tube is irradiated with the inspection light and the change in the refractive index of the inspection light transmitted through the tube and the light receiving intensity. A method is also known in which the presence or absence of bubbles in a specimen is determined by measuring the change in the above.
JP 2002-333434 A (pages 3-4, FIG. 2) Japanese Patent Laid-Open No. 2002-131288 (pages 4-5, FIG. 1) Japanese Patent Laid-Open No. 7-198682 (page 3, FIG. 1) Japanese Patent Laid-Open No. 5-50009 (page 3, FIG. 1) JP 2001-336966 A (page 4, FIG. 1)

  By the way, the method using ultrasonic waves as described in Patent Documents 1 and 2 and the method using magnetism as described in Patent Document 3 have a problem that they are easily affected by a high-frequency electromagnetic field. is there. As a result, erroneous detection may occur due to noise generated from the biochemical analyzer itself or external noise generated from other analyzers or electronic devices. In this case, there is a method of electromagnetically shielding the dispensing apparatus, but there arises a problem that the apparatus becomes large and the manufacturing cost increases.

  In addition, in the methods using inspection light as described in Patent Documents 4 and 5, a detector that detects inspection light receives light from the outside, and erroneous detection occurs, or detection sensitivity decreases. There is a risk of In order to prevent these, it is necessary to shield the light, but similarly, there is a problem that the apparatus becomes large and the manufacturing cost increases.

  An object of the present invention is to provide a liquid property determination apparatus and method that do not require light shielding and are not easily affected by external noise or the like.

  The liquid property determination apparatus of the present invention has a liquid passage through which a liquid is circulated, and a constant temperature portion that maintains the temperature of the liquid circulated in the liquid passage by energization at a constant temperature, and power consumption of the constant temperature portion And a liquid property determining unit for determining the property of the liquid flowing through the liquid passage based on the power consumption.

  It is preferable that the liquid state determination unit determines whether or not a gas that becomes bubbles is mixed in the liquid. Further, it is preferable that the liquid property determination unit determines that the gas is mixed in the liquid flowing through the liquid passage when the power consumption falls below a predetermined threshold value. Furthermore, it is preferable that the threshold value be varied so as to increase as the flow rate of the liquid increases and to decrease as the flow rate decreases.

  It is preferable to provide a gas quantification unit that quantifies the amount of the gas mixed in the liquid from the power consumption. Moreover, it is preferable that the said gas fixed_quantity | quantitative_assay part quantifies the mixing amount of the said gas based on the relationship between the said power consumption and the mixing amount of the said gas mixed in the said liquid. Furthermore, the relationship between the power consumption and the amount of the gas mixed in the liquid is expressed by using the flow rate of the liquid as a variable, and the amount of the gas mixed is the same as the power consumption. If so, it is preferable that the flow rate increases as the flow rate increases, and decreases as the flow rate decreases.

  Further, the liquid property determination method of the present invention controls the energization of a temperature adjusting member that adjusts the temperature of the liquid to be circulated so as to keep the liquid at a constant temperature while keeping the liquid at a constant temperature. The power consumption required by the temperature adjusting member is detected, and the property of the liquid is determined based on the detected power consumption.

  The liquid property determination apparatus of the present invention detects a constant temperature portion that maintains the temperature of the liquid flowing through the liquid passage at a constant temperature, power consumption of the constant temperature portion, and based on the detection result, Unlike the conventional method using ultrasonic waves or magnetism, erroneous detection may occur due to the influence of external noise, etc. It is not. Further, unlike the method using inspection light, it is not necessary to shield the light, so that it is possible to prevent the apparatus from being enlarged and the manufacturing cost from being increased.

  In addition, the liquid property determination method of the present invention detects the power consumption required by the temperature adjustment member while controlling the energization to the temperature adjustment member that adjusts the temperature of the flowing liquid to maintain the liquid at a constant temperature. In addition, since the property of the liquid is determined based on the detected power consumption, there is no risk of being affected by external noise or the like, and there is no need to perform light shielding. In addition, in an apparatus that requires a constant temperature part, the constant temperature part functions as a sensor that detects a change in the properties of the liquid, such as bubbles, and it is not necessary to provide a separate sensor, thereby simplifying the structure of the apparatus.

  FIG. 1 shows a schematic view of a dispensing device 10. The dispensing device 10 is incorporated in a biochemical analyzer (not shown) used in medical institutions, laboratories, and the like. As described above, the biochemical analyzer (not shown) measures the test chips 12a and 12b on which the droplets of the specimen 11 such as blood and urine are spotted, thereby specifying a specific one contained in the specimen 11. Analyze the concentration of biochemical substances.

  The dispensing apparatus 10 sucks and collects the sample 11 from the sample storage container 14 in which the sample 11 is stored, and deposits the collected samples on the test chips 12a and 12b, respectively. The dispensing device 10 includes a suction probe 15, an air tube 16, a syringe pump 17, a pump drive unit 18, a probe moving unit 19, a pressure sensor 20, and a bubble mixing determination unit 21. A suction tip (not shown) that can be replaced for each specimen 11 may be inserted into the suction probe 15.

  The suction probe 15 is installed with a suction port (not shown) facing downward, and one end of an air tube 16 is connected to the upper part. The other end of the air tube 16 is connected to a syringe pump 17 as a suction / discharge mechanism for the specimen 11. The syringe pump 17 is driven by a pump drive unit 18. The pump drive unit 18 includes a motor 23 and a feed screw mechanism 24 that converts the rotation of the motor 23 into a reciprocating movement. Then, by rotating the motor 23 forward or backward, the plunger 25 in the syringe pump 17 is reciprocated to suck and discharge the specimen 11 from the suction probe 15. The mechanism for converting the rotation of the motor 23 into the reciprocating movement of the plunger 25 is not limited to the feed screw mechanism 24, and a ball screw mechanism, a rack and pinion, or other conversion mechanism may be used.

  The probe moving unit 19 includes a horizontal moving unit and an elevating unit (not shown). The horizontal movement unit horizontally moves the suction probe 15 to the suction standby position above the sample storage container 14 and to the first and second spotting standby positions above the test chips 12a and 12b. In the drawing, only two inspection chips are set, but only one or three or more inspection chips may be set as necessary. The elevating unit raises and lowers the suction probe 15 between the suction standby position and the suction position where the suction port contacts the sample 11 in the sample storage container 14, and each spotting standby position and the suction port are the inspection chip. It raises / lowers between the first and second landing positions adjacent to 12a and 12b.

  When the aspiration probe 15 is moved to the aspiration position, the height of the liquid level of the sample 11 stored in the sample storage container 14 is different for each container. Therefore, the pressure sensor 20 is connected to the intermediate position of the air tube 16 via the branch pipe 27 so that it can be detected that the suction port of the descending suction probe 15 contacts the liquid surface of the specimen 11. The pressure sensor 20 converts the pressure in the air tube 16 into a pressure signal and outputs this pressure signal. As a result, when the suction port of the suction probe 15 comes into contact with the specimen 11, the pressure detected by the pressure sensor 20 increases, so that it is detected that liquid contact has occurred.

  When it is detected that the suction port of the suction probe 15 is in contact with the sample 11, the motor 23 is driven to rotate, and the plunger 25 of the syringe pump 17 is moved by a certain amount, so that the sample 11 passes through the air probe via the suction probe 15. 16 is aspirated. After the sample 11 is aspirated, the probe moving unit 19 moves the aspiration probe 15 to the first spotting position via the first spotting standby position. Then, the motor 23 is rotated again to move the plunger 25 by a predetermined amount, and a predetermined amount of the specimen 11 is dropped onto the test chip 12a and spotted.

  After the sample 11 is spotted, the suction probe 15 is moved to the second spotting position via the second spotting standby position, and the sample 11 is spotted on the test chip 12b in the same manner. The test chips 12a and 12b on which the specimen 11 is spotted are set at a predetermined measurement position in a biochemical analyzer (not shown) and photometrically measured by a chip detection sensor (not shown) in the analyzer. The biochemical analyzer performs a predetermined biochemical analysis process with reference to the photometric signal stored in advance and the substance concentration of the biochemical substance in the sample based on the photometric signal output from the chip detection sensor.

  In the biochemical analysis process, as is well known, a dry type dry process capable of quantitatively analyzing a specific chemical component or formed component contained in a sample by simply spotting and supplying a small droplet of the sample 11. It is common to use an inspection chip such as an analytical element or an electrolyte slide (dry ion selective electrode film), and the sample 11 is subjected to a colorimetric measurement method using a dry analytical element or a potential difference measurement method using an electrolyte slide. Quantitative analysis of chemical components, etc.

  In a biochemical analysis process using a colorimetric measurement method, a specimen is spotted on test chips (dry analytical elements) 12a and 12b, and then held at a constant temperature in an incubator (incubator) for a color reaction ( (Pigment generation reaction), the measurement light including a preselected wavelength is irradiated onto the dry analytical element, the optical density thereof is measured, and the substance concentration of the biochemical substance is obtained from the optical density. On the other hand, a biochemical analyzer using a potentiometric measurement method contacts a sample 11 spotted on test chips (electrolyte slides) 12a and 12b with a pair of electrodes of the same type of dry ion selection electrode. The substance concentration is determined by quantitative analysis of the activity of specific ions by potentiometry.

  The substance concentration of the biochemical substance in the specimen 11 obtained by using such various measuring methods can be determined accurately by spotting the specimen 11 on the test chips 12a and 12b. Therefore, if bubbles 29 (see FIG. 2) are mixed when the sample 11 is aspirated, the amount of the sample 11 to be spotted on the test chips 12a and 12b decreases, and there is a possibility that accurate analysis cannot be performed. Therefore, in the present embodiment, a bubble mixing determination unit 21 is provided in the middle of the air tube 16 to detect whether or not the air that becomes the bubbles 29 is mixed in the sample 11.

  FIG. 2 shows a cross-sectional view of the bubble mixing determination unit 21 corresponding to the liquid property determination apparatus of the present invention. The bubble mixing determination unit 21 is roughly composed of a cylindrical heater housing 31, a heater 32, and a temperature sensor 33.

  The heater housing 31 is provided in the middle of the air tube 16. The heater housing 31 is formed of, for example, an aluminum material, and the inner side surface thereof is a liquid passage 35 through which the specimen 11 is circulated. The liquid passage 35 is formed in a substantially circular shape in cross section, and both ends thereof are connected to the air tube 16. In this embodiment, the air tube 16 has an outer diameter φ1 of 4 mm and an inner diameter φ2 of 3 mm. The heater housing 31 has a length L of 30 mm, a width W of 8 mm, and a diameter φ3 of the liquid passage 35. What was formed in 3 mm is used. The heater housing 31 may have a polygonal cross section other than a cylindrical one as long as it is cylindrical.

  The heater 32 corresponds to the temperature adjusting means (temperature adjusting member) of the present invention, and is provided in a heater chamber 31a formed between the inner side surface (liquid passage 35) and the outer side surface of the heater housing 31. ing. The heater 32 generates heat when energized, and the temperature of the heater housing 31 can be adjusted by controlling the energization. As the heater 32, various heaters such as a coil heater, a rod heater, and a sheet heater may be used.

  The temperature sensor 33 corresponds to the temperature detection means of the present invention, and is provided in a sensor chamber 31b formed between the inner surface and the outer surface of the heater housing 31, and detects the temperature of the heater housing 31. . As the temperature sensor 33, for example, various temperature detection elements such as a thermistor are used. In addition, although the position which forms both chambers 31a and 31b is not specifically limited, both chambers 31a and 31b are formed side by side along the liquid passage 35 in this embodiment.

  Thus, by incorporating the heater 32 and the temperature sensor 33 in the heater housing 31, the heater housing 31 becomes a constant temperature body that keeps the temperature of the specimen 11 flowing through the liquid passage 35 at a constant temperature. Therefore, in the present embodiment, the temperature of the heater housing 31 is controlled by the heater 32, and the specimen 11 circulated in the liquid passage 35 is held at a constant temperature higher than before being circulated in the liquid passage 35. Like that. At this time, the amount of heat (heat radiation amount) taken from the heater housing 31 by the specimen 11 and air is proportional to the heat capacity of the specimen 11 and air. In general, since the heat capacity of water is 1000 times or more the heat capacity of air of the same volume, the heater housing 31 is cooled when the specimen 11 having a higher heat capacity than the heater housing 31 flows through the liquid passage 35. As a result, the heater 32 always consumes constant power in order to keep the temperature of the heater housing 31, that is, the temperature of the specimen 11 flowing through the liquid passage 35 constant.

  At this time, if the air that becomes the bubbles 29 is mixed in the specimen 11, the heat dissipation amount of the heater housing 31 decreases in proportion to the amount of the mixing, and the power consumption of the heater 32 decreases accordingly. Therefore, in this embodiment, by detecting the power consumption of the heater 32, the air mixed in the sample 11 is quantified to determine whether or not the bubbles 29 are mixed in the sample 11.

  The controller 38 performs temperature control of the heater 32, detection of power consumption, determination of the amount of air mixing, and determination of mixing of bubbles 29. The controller 38 is connected to the probe moving unit 19, the pressure sensor 20, the motor 23, the temperature sensor 33, the environmental temperature sensor 39, and the like. In addition to the heater control circuit 41, the power consumption detection circuit 42, the air quantification circuit 43, and the determination circuit 44, the controller 38 includes a probe movement control unit, a motor drive control unit, and the like (not shown). The drive of each part of the dispensing device 10 is controlled.

  The environmental temperature sensor 39 measures the environmental temperature around the dispensing device 10. Since the temperature of the specimen 11 in the specimen storage container 14 is substantially equal to the environmental temperature, the temperature of the specimen 11 can be detected by detecting the environmental temperature. As the environmental temperature sensor 39, various temperature detection elements such as a thermistor can be used as with the temperature sensor 33.

  The heater control circuit 41 corresponds to the temperature control means of the present invention. Based on the temperature signal input from the temperature sensor 33, the heater control circuit 41 keeps the temperature of the heater housing 31 at a preset temperature. Control the temperature. As a method of controlling the temperature of the heater 32, a method of changing the magnitude of the voltage applied to the heater 32, or a PWM (Pulse Width) which changes the duty ratio of the pulse voltage by applying a rectangular wave pulse voltage to the heater 32. There is a method for performing (Modulation) control, and either method may be used. In this embodiment, the temperature of the heater housing 31 (the temperature of the specimen 11 in the liquid passage 35) is at least 10 ° C. higher than the temperature of the specimen 11 (environmental temperature) before flowing through the liquid passage 35, Further, the sample 11 is kept within a range of 10 to 60 ° C. where no bubbles 29 are generated.

  The power consumption detection circuit 42 constitutes a liquid property determination unit of the present invention together with a determination circuit 44 described later, and detects the power consumption of the heater 32. Specifically, the power consumption of the heater 32 is detected by detecting the magnitude of the voltage applied to the heater 32 by the heater control circuit 41 or the duty ratio of the rectangular wave pulse voltage applied to the heater 32. . The detected power consumption value of the heater 32 is output to the air determination circuit 43 and the determination circuit 44 as needed.

  The air quantification circuit 43 corresponds to the gas quantification unit of the present invention, and obtains the amount of air mixed in the sample 11 flowing through the liquid passage 35 based on the input power consumption value. The air determination circuit 43 has an arithmetic expression indicating the relationship between the power consumption of the heater 32 and the amount of air mixed in the specimen 11, and the air consumption value is substituted into the arithmetic expression to substitute the air. The amount of mixing is calculated. Instead of using an arithmetic expression, the amount of air mixed may be obtained by using a graph or a data table of the relationship between the two.

  At this time, if the flow rate of the specimen 11 flowing through the liquid passage 35 is different, the power consumption of the heater 32 becomes a different value even if the air mixing amount is the same. That is, as the flow rate of the specimen 11 increases, the circulation amount of the specimen 11 per unit time increases, so that the heat dissipation amount of the heater housing 31 increases and the power consumption increases. Conversely, the slower the flow rate, the lower the heat dissipation and the lower the power consumption. Therefore, by using the above-described arithmetic expression as a variable with the flow rate of the specimen 11 as a variable, an accurate air mixing amount can be obtained even if the flow speed of the specimen 11 changes. An arithmetic expression using this flow rate as a variable is obtained by conducting an experiment or the like in advance. The flow rate of the specimen 11 is proportional to the rotational speed of the motor 23 if the diameter φ3 of the liquid passage 35, the inner diameter φ2 of the air tube 16 and the inner diameter of the syringe pump 17 are constant.

  FIG. 3 is an example of a graph of the above-described arithmetic expression, and shows the relationship between the power consumption and the ratio of air in the sample 11 when the flow rate of the sample 11 is V1 and when it is V2 faster than V1. It is a thing. As described above, the flow rate of the specimen 11 per unit time increases at the flow velocity V2, so that the power consumption increases. Therefore, if the power consumption is the same, the ratio of the air quantified by the calculation formula becomes larger at the flow velocity V2.

  When bubbles 29 (air) are not mixed in the specimen 11 flowing in the liquid passage 35, the power consumption is substantially constant although there is a difference in value depending on the flow velocity. When air that becomes bubbles 29 is mixed into the specimen 11, the power consumption decreases in proportion to the increase in the amount of the mixed air. When the ratio of air is 100%, that is, when only air is circulated in the liquid passage 35, the power consumption again becomes substantially constant at the lower limit value. By using such an arithmetic expression, the air determination circuit 43 can obtain an accurate air mixing amount even when the flow velocity is changed.

  As shown in FIGS. 2 and 3, the determination circuit 44 determines whether or not the air that becomes the bubbles 29 is mixed in the sample 11 that flows in the liquid passage 35 based on the input power consumption value, and It is determined whether or not only air is circulating in the liquid passage 35. The determination circuit 44 has a value that affects the amount of the specimen 11 spotted on the test chips 12a and 12b when the power consumption value falls below a predetermined threshold, that is, the ratio of air in the specimen 11. When it becomes, it determines with the bubble 29 having mixed in the test substance 11. FIG.

  At this time, since the power consumption of the heater 32 changes according to the flow rate of the sample 11, the threshold value is also changed according to the flow rate of the sample 11. For example, when the threshold value at the flow velocity V1 is T1, the threshold value T2 at the flow velocity V2 is higher than T1. The threshold values T1 and T2 corresponding to the flow rate of the specimen 11 are obtained in advance through experiments or the like, similarly to the above-described arithmetic expression.

  Further, the determination circuit 44 determines that only air is circulated in the liquid passage 35 when the input power consumption value reaches the lower limit value. Thereby, it is possible to detect the presence or absence of the sample 11 in the liquid passage 35, that is, whether or not all of the sample 11 collected by suction has passed through the liquid passage 35. Therefore, if the determination circuit 44 does not determine that the bubbles 29 are mixed before the power consumption value reaches the lower limit value, the determination circuit 44 determines that the bubbles 29 are not mixed in the sample 11 collected by suction. In the present embodiment, the installation position of the bubble mixing determination unit 21 and the length of the air tube are adjusted so that all of the aspirated sample 11 can pass through the liquid passage 35.

  Although not shown, the determination circuit 44 stores a data table in which the flow rate of the specimen 11 is associated with the threshold value and lower limit value of power consumption corresponding to the flow rate. Thereby, the determination circuit 44 can determine whether or not the bubbles 29 are mixed in the sample 11 aspirated and collected based on the input power consumption value regardless of the flow rate of the sample 11.

  When the determination circuit 44 determines that the bubble 29 is not mixed in the sample 11, the controller 38 drives the probe moving unit 19 to move the suction probe 15 to the first spotting position, and moves the sample to the test chip 12a. 11 is spotted. In addition, when it is determined that the air bubbles 29 are mixed in the sample 11, the controller 38 discharges the sample 11 that has been aspirated and then performs aspiration collection of the sample 11 again.

  Next, the operation of this embodiment will be described. When the specimen storage container 14 and the test chips 12a and 12b are set in the dispensing device 10 and the operation is started by the operator, the controller 38 drives the probe moving unit 19 to lower the suction probe 15 at the suction standby position. Let Based on the pressure signal from the pressure sensor 20, the controller 38 moves the suction probe 15 to the suction position where the specimen 11 comes into contact with the suction port. Next, the controller 38 drives the motor 23 to move the plunger 25 in the syringe pump 17, and aspirates the specimen 11 from the aspiration probe 15.

  The heater control circuit 41 of the controller 38 starts energization to the heater 32 before starting the sampling of the specimen 11 and adjusts the temperature of the heater housing 31 to a predetermined temperature higher than the temperature of the specimen 11 (environmental temperature). To do. At the same time, the power consumption detection circuit 42 detects the power consumption of the heater 32 based on the magnitude of the voltage applied to the heater 23 or the duty ratio of the applied rectangular wave pulse voltage, and the detected consumption The power value is output to the air determination circuit 43 and the determination circuit 44.

  When the specimen 11 sucked from the suction probe 15 passes through the liquid passage 35 of the heater housing 31 and the heat dissipation amount of the heater housing 31 increases, the heater control circuit 41 based on the detection signal from the temperature sensor 33. The current to the heater 32 is controlled so that the temperature of the sample 11 flowing through the liquid passage 35 is always maintained at a predetermined temperature.

  The air quantification circuit 43 substitutes the power consumption value input from the power consumption detection circuit 42 into the above-described arithmetic expression, and calculates the amount of air contamination (mixing ratio) in the specimen 11. At this time, in the present embodiment, an accurate air mixing amount can be obtained even if the flow rate of the specimen 11 changes by making the arithmetic expression a formula with the flow speed of the specimen 11 as a variable (see FIG. 3). .

  Based on the input power consumption value, the determination circuit 44 determines whether the air that becomes the bubbles 29 in the sample 11 that flows through the liquid passage 35 depends on whether the power consumption value falls below a threshold value corresponding to the flow velocity. It is determined whether or not it is mixed. If the determination circuit 44 does not determine that the bubbles 29 are mixed before the power consumption value reaches the lower limit value, the determination circuit 44 determines that the bubbles 29 are not mixed in the sample 11 collected by suction. .

  When the determination circuit 44 determines that the bubbles 29 are not mixed, the controller 38 drives the probe moving unit 19 to move the suction probe 15 to the first spotting position. Next, the controller 38 drives the motor 23 to move the plunger 25 so that a predetermined amount of the sample 11 is dropped onto the test chip 12a. Similarly, the specimen 11 is dropped on the inspection chip 12b. In addition, when the determination circuit 44 determines that the bubbles 29 are mixed, the controller 38 moves the plunger 25 to discharge the sample 11, and then issues an alarm as necessary to perform aspiration sampling of the sample 11 again. Hereinafter, the above-described processing is repeated until it is determined that the bubbles 29 are not mixed. Alternatively, an upper limit of the number of suction retries may be set, and when this upper limit is exceeded, an alarm or display may be performed so that suction is not performed again.

  As described above, in the present embodiment, the heater 11 is controlled so that the sample 11 flowing through the flow passage 35 is maintained at a constant temperature, and the power consumption of the heater 32 is detected to detect the power in the sample 11. Since the presence / absence of the bubble 29 is determined, unlike the bubble detection method using conventional ultrasonic waves or magnetism, there is no possibility of erroneous detection due to the influence of external noise or the like. In addition, unlike the bubble detection method using inspection light, it is not necessary to shield light, so that the apparatus is prevented from being enlarged and the manufacturing cost being increased.

  The test chips 12a and 12b on which the specimen 11 is spotted are set at predetermined measurement positions in a biochemical analyzer (not shown). The biochemical analyzer performs predetermined biochemistry by referring to the photometric signal stored in advance and the substance concentration of the biochemical substance in the specimen 11 based on the photometric signal output by measuring the test chips 12a and 12b. Perform analysis processing.

  In addition, in the said embodiment, although the cross-sectional shape of the liquid channel | path 35 is formed in perfect circle shape, this invention is not limited to this. When the contact area where the liquid passage 35 having a perfect circular cross-sectional shape is in contact with the specimen 11 is S, the liquid passage may be formed in a cross-sectional shape such that the contact area is larger than S.

  Specifically, like the cylindrical body 50 shown in FIG. 4, the cross-sectional shape of the liquid passage 51 may be formed in a star polygonal shape. Further, like the cylindrical body 55 shown in FIG. 5, the liquid flow path 56 may have a honeycomb structure including a plurality of cross-sectional polygonal (or circular) flow holes 57. As a result, the contact area between the specimen 11 and the cylindrical bodies 50 and 55 increases when the specimen 11 is circulated through the liquid passages 51 and 56, so that the power consumption of the heater 32 depends on whether or not the specimen 11 contains bubbles 29. Variation, that is, detection sensitivity can be increased.

  In the above embodiment, the heater chamber 31a in which the heater 32 is provided and the sensor chamber 31b in which the temperature sensor 33 is provided are formed side by side along the liquid passage 35, but the present invention is not limited to this. Instead, the heater chamber 31a and the sensor chamber 31b may be formed side by side in a direction perpendicular to the direction along the liquid passage 35, and the positions of the chambers 31a and 31b are not particularly limited. In addition, a flexible heater such as a sheet heater may be used as the heater 32, and this heater may be provided so as to surround the liquid passage 35. Further, the outer surface of the heater housing 31 may be surrounded by a flexible heater. Further, the number of heaters 32 and temperature sensors 33 is not limited to one, and a plurality of heaters 32 and temperature sensors 33 may be provided.

  In the bubble mixing determination unit 21 of the above embodiment, the heater housing 31 is provided so as to divide the air tube 16. However, the present invention is not limited to this, and the heater housing 31 is provided in the air tube 16. It may be provided so as to surround the outer surface of the. In this case, since the cylindrical body 16 is in contact with the specimen 11 through the air tube 16 serving as a liquid passage, the fluctuation in power consumption due to the presence or absence of the bubbles 29 is reduced, but the existing air tube 16 is cut. There is an advantage that it can be easily installed without any problems.

  Moreover, in the said embodiment, the heater 32 was provided in the heater housing 31, and this heater housing 31 was kept at the temperature higher than the temperature of the test substance 11, However, This invention is not limited to this. For example, a Peltier element or the like may be provided in the heater housing 31 or surrounding the heater housing 31 to keep the heater housing 31 at a temperature lower than the temperature of the specimen 11. Also in this case, since the power consumption of the Peltier element varies depending on whether or not the air that becomes the bubbles 29 is mixed in the sample 11 flowing in the liquid passage 35, it is determined whether or not the bubbles 29 are mixed. be able to

  In the above embodiment, the air in the air tube 16 and the syringe pump 17 is used as a pressure medium for aspirating the sample 11 in conjunction with the movement of the plunger 25, but the present invention is limited to this. It is not a thing. For example, the amount of suction of the specimen 11 can be controlled more accurately by using a liquid such as water, such as water, whose volume does not change as the pressure medium. Hereinafter, a dispensing device 86 that uses water 85 as a pressure medium will be described with reference to FIG. In FIG. 6, components having the same functions as those described in the above-described dispensing apparatus 10 are denoted by the same reference numerals and description thereof is omitted. Reference numeral 87 in the figure denotes a seal member.

  The dispensing device 86 has basically the same configuration as the dispensing device 10 shown in FIG. However, the dispensing device 86 is provided with a liquid level detector 88 and a water supply unit 89 that fills the air tube 16 and the syringe pump 17 with water 85. The liquid level detector 88 detects the capacitance between the suction probe 15 and the liquid level in the sample storage container 14, and the suction probe 15 contacts the sample 11 based on the change in capacitance between the two. Detecting that

  The water supply unit 89 includes a liquid pipe 94, a water storage tank 95, a pump 96, an electromagnetic valve 97, and a bubble mixing determination unit 98. The liquid pipe 94 has one end connected to the water storage tank 95 and opened in the tank, and the other end connected to the syringe pump 17 through the joint member 99 and opened in the pump 17. A pump 96, a solenoid valve 97, and a bubble mixing determination unit 98 are provided in the middle of the liquid pipe 94.

  The pump 96 sends the water 85 stored in the water storage tank 95 into the syringe pump 17. The electromagnetic valve 97 is opened only when the water 85 is filled, and is closed when the specimen 11 (see FIG. 1) is aspirated. The bubble mixing determination unit 98 determines whether or not the bubbles 29 (see FIG. 2) are mixed in the water 85 filled in the air tube 16 and the syringe pump 17 via the liquid pipe 94. The bubble mixing determination unit 98 is the same as the above-described bubble mixing determination unit 21 (see FIG. 2), and includes a heater housing 100, a heater 101, a temperature sensor 102, and the like.

  In the dispensing device 86, the electromagnetic valve 97 is opened before the specimen 11 is aspirated, and at the same time, the pump 96 is driven to supply water 85 into the air tube 16 and the syringe pump 17. The water 85 is supplied until water is discharged from the tip of the suction probe 15. Thereby, it can confirm that the inside of the air tube 16 and the syringe pump 17 was filled with the water 85. FIG. At this time, the bubble mixing determination unit 98 drives the heater 101 so that the heater housing 100 maintains a predetermined temperature higher than the water 85 based on the temperature signal output from the temperature sensor 102. Therefore, by detecting the power consumption of the heater 101 as described above, it is possible to determine whether or not the bubbles 29 in the water 85 flowing through the liquid pipe 94 are mixed. Note that the presence / absence of the bubbles 29 in the water 85 may be determined using the bubble mixing determination unit 21 in combination. If it is determined that the air bubbles 29 are mixed, the plunger 25 is similarly moved to discharge the water 85, and then the water 85 is suctioned and collected again.

  When the bubble mixing determination unit 98 determines that the bubbles 29 are not mixed, the electromagnetic valve 97 is closed. Next, the plunger 25 is moved, and the water 85 in the aspiration probe 15 is aspirated to a position that does not affect the aspiration of the specimen 11, that is, a position that does not mix with the aspirated specimen 11. Thereby, the preparation for aspirating the specimen 11 using the water 85 as the pressure medium is completed. When this preparation is completed, the sample storage container 14 and the reaction container 103 are set at predetermined positions. Then, similarly to the dispensing apparatus 10 described above, the sample 11 is aspirated, the presence / absence of bubbles 29 in the sample 11 is determined by the bubble mixing determination unit 21, and the sample 11 is dropped into the reaction container 103. A reagent (not shown) or the like is dropped into the reaction vessel 103 before or after the specimen 11 is dropped, and various tests or tests are performed. Note that the above-described inspection chips 12 a and 12 b may be set instead of the reaction vessel 103.

  Moreover, in the said embodiment, although what was incorporated in the dispensing apparatus 10 of a biochemical analyzer as the bubble mixing determination part 21 was described as an example, the present invention is not limited to this. For example, according to the present invention, in various apparatuses such as an immunological test apparatus, a trace liquid homogenizing apparatus, an artificial dialysis machine, a medical chemical injection apparatus, an ink jet printer, and a coating apparatus, bubbles are mixed in various circulated liquids. It can also be used when determining whether or not it is.

  In the above-described embodiment, the case where the presence / absence of the bubbles 29 in the specimen 11 is determined has been described as an example. However, the present invention is not limited to this, and changes in the properties of the liquid such as the specimen 11 are not limited thereto. It can also be used when determining the presence or absence. Specifically, when another type of liquid or foreign matter is mixed in various liquids circulated in the liquid passage, the power consumption of the heater 32 varies as in the case where the bubbles 29 are mixed. Therefore, it is possible to determine whether or not there is a change in the properties of various liquids that are circulated in the liquid passages provided in the above-described apparatuses and plants based on the power consumption of the heater 32 in the same manner.

The perspective view of a dispensing apparatus is shown. The cross-sectional view of the bubble mixing determination unit of the dispensing device is shown. FIG. 5 is a graph showing an arithmetic expression showing the relationship between the power consumption of the heater of the bubble mixing determination unit and the amount of air mixed in the specimen. The cross-sectional view of the cylindrical body of other embodiment which made the cross-sectional shape of the liquid path into the star-shaped polygonal shape is shown. It is sectional drawing of the cylindrical body of other embodiment which comprised the liquid channel | path from the some through-hole. It is the schematic of the dispensing apparatus of other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Dispensing apparatus 11 Specimen 12a, 12b Test chip 15 Suction probe 16 Air tube 21 Bubble mixing determination part 31 Heater housing 32 Heater 33 Temperature sensor 35 Liquid passage 38 Controller 41 Heater control circuit 42 Power consumption detection circuit 43 Air quantitative circuit 44 Determination circuit

Claims (11)

A constant temperature section having a liquid passage through which the liquid is circulated, and maintaining the temperature of the liquid circulated through the liquid passage by energization at a constant temperature;
A liquid property determination apparatus comprising: a liquid property determination unit that detects power consumption of the constant temperature portion and determines the property of the liquid flowing through the liquid passage based on the power consumption.   The liquid property determining apparatus according to claim 1, wherein the liquid determining unit determines whether or not a gas that becomes bubbles is mixed in the liquid.   The liquid property determination unit determines that the gas is mixed in the liquid flowing through the liquid passage when the power consumption falls below a predetermined threshold value. The liquid property determination apparatus described.   4. The liquid property determination according to claim 3, wherein the threshold value is varied so as to increase as the flow velocity of the liquid increases and to decrease as the flow velocity decreases. apparatus.   The liquid property determining apparatus according to claim 2, further comprising a gas quantification unit that quantifies the amount of the gas mixed in the liquid based on the power consumption.   The liquid property determination device according to claim 5, wherein the gas quantification unit quantifies the amount of the mixed gas based on the relationship between the power consumption and the mixed amount of the gas mixed in the liquid. . The relationship between the power consumption and the amount of the gas mixed in the liquid is expressed with the flow rate of the liquid as a variable,
The mixed amount of the gas increases as the flow rate increases and decreases as the flow rate decreases when the power consumption is the same. 6. The liquid property judging device according to 6.   The liquid passage is formed in a cross-sectional shape such that the contact area is larger than S, where S is a contact area where the liquid passage having a perfect circular cross-section is in contact with the specimen. The liquid property determining apparatus according to claim 1. The constant temperature part is
Temperature adjusting means capable of adjusting the temperature of the liquid passage by the energization;
Temperature detecting means for detecting the temperature of the liquid passage;
Temperature control means for controlling the temperature control means so that the temperature of the liquid flowing through the liquid passage is maintained at a constant temperature based on the temperature detected by the temperature detection means. The liquid property determination apparatus according to claim 1.   The temperature control means controls the temperature control means so that the liquid flowing in the liquid passage is maintained at a temperature higher by 10 ° C. or more than before being flowed in the liquid passage. 10. The liquid property determining apparatus according to claim 1, wherein the liquid property determining apparatus is a liquid property determining apparatus. Detecting power consumption required by the temperature adjustment member to maintain the liquid at a constant temperature while controlling the energization of the temperature adjustment member for adjusting the temperature of the liquid to be circulated to maintain the liquid at a constant temperature. A liquid property determination method characterized by determining the property of the liquid based on the detected power consumption.

Images