JP2007086036A - Liquid property change detecting device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the detection accuracy of bubbles, and to dispense with the need for adjustment corresponding to dispersion of light emission/reception characteristics or to the changes in the lapse of time. <P>SOLUTION: In this liquid property change detecting device, a bubble detection part 21 of a dispensing device is formed from a bubble detection cell 31 having a liquid passage 35 for circulating a specimen 11, a floodlighting unit 32, and a light-receiving unit 33. Both units 32, 33 are arranged so as to sandwich the bubble detection cell 31. The bubble detection cell 31 is formed of a translucent material, having approximately the same refraction as the specimen 11. The bubble detection cell 35 is formed so that the section of the liquid passage 35 has a substantially triangular shape, and that a liquid contact face 35a onto which inspection light L is floodlighted has a tilt angle of 45°, with respect to the optical axis O of the inspection light L. If bubbles are mixed into the liquid passage 35, the floodlighted inspection light L is totally reflected on the liquid contact face 35a in a direction different from the direction of going toward the light-receiving unit 33. Since the change in the light-receiving quantity at the light receiving unit 33 caused by existence of bubble contamination is enlarged, the detection accuracy of bubbles can be improved. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid property change detection apparatus and method for detecting a change in the property of a flowing 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. In general, a biochemical analyzer is equipped with a dispensing device.

  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, the presence or absence of changes in the sample properties such as whether or not bubbles are mixed is detected. If bubbles are mixed, the sample is completely discharged, and then the sample is aspirated again. Is going.

As a specific detection method, as described in Patent Documents 1 and 2, an air tube is formed of a translucent material, and inspection light is projected onto the air tube. A method for detecting the presence or absence of bubbles in a sample by measuring changes in the refractive index of the inspection light transmitted through the air tube and changes in the amount of received light is well known.
Japanese Patent Laid-Open No. 5-50009 (page 3, FIG. 1) JP 2001-336966 A (page 4, FIG. 1)

  Incidentally, the methods using inspection light as described in Patent Documents 1 and 2 have a problem that detection accuracy is not good because changes in refractive index and received light amount due to the presence or absence of bubbles are small. If this detection accuracy is to be improved, the processing circuit and program for processing the received light signal output from the light receiving unit that receives the inspection light will be complicated, and the manufacturing cost of the dispensing device will increase.

  In addition, when manufacturing a dispensing device, the presence or absence of bubbles is determined for each device according to variations in light receiving and emitting characteristics of the light projecting unit that projects the inspection light toward the light receiving unit and the air tube. Therefore, it is necessary to adjust the threshold value of the received light amount. Furthermore, when the light projecting intensity of the light projecting unit and the light receiving sensitivity of the light receiving unit are reduced due to changes over time, it is necessary to request a serviceman to adjust the threshold value. There is a problem that a biochemical analyzer with embedded can not be used.

  An object of the present invention is to solve the above-described problems, and a liquid property change detection apparatus and method that can easily improve detection accuracy and do not require adjustment according to variations in light receiving and emitting characteristics and changes with time. The purpose is to provide.

  The present invention includes a translucent liquid passage through which a liquid flows, a light projecting unit that projects light toward the liquid channel, a light receiving unit that receives the light transmitted through the liquid channel, and the light receiving unit. A liquid property change detecting device having a detection unit for detecting a property change of the liquid flowing in the liquid passage based on the amount of light received by the portion. When the property of the liquid is not changed, the light is allowed to reach the light receiving unit, and when the property of the liquid is changed, the contact of the liquid passage is caused by the change of the refractive index in the liquid passage. The liquid surface is formed in a shape capable of being refracted or reflected in a direction in which at least most of the light does not reach the light receiving portion.

  It is preferable that the light is parallel light before reaching the liquid passage. In addition, the liquid passage has a substantially polygonal cross-sectional shape, and a liquid contact surface of the liquid passage on a side where the light is projected from the light projecting portion is the light beam with respect to the optical axis of the light. It is preferable to have an inclination angle that can be refracted or reflected in a direction not reaching the light receiving portion.

  The liquid passage has a substantially circular cross-sectional shape, and the light projecting portion has an angle formed by the optical axis of the light and a liquid contact surface of the liquid passage so that most of the light passes to the light receiving portion. It is preferable to be disposed at a position where the angle can be refracted or reflected in a direction that does not reach. The liquid contact surface of the liquid passage is preferably an inner surface of a translucent cylinder having a light incident surface facing the light projecting portion and a light emitting surface facing the light receiving portion.

  The light projecting unit projects the light radially, and the light incident surface is curved to be convex in a direction toward the light projecting unit, and the light projected radially is converted into parallel light. It is preferable to do. Further, it is preferable that the light emitting surface is curved so as to be convex in a direction toward the light receiving unit, and the light emitted from the light emitting surface is condensed on the light receiving unit.

  The cylindrical body preferably has substantially the same refractive index as the liquid. Moreover, it is preferable that the light projecting unit and the light receiving unit are disposed so as to sandwich the liquid passage. Moreover, it is preferable that the said detection part detects whether the bubble is mixed in the said liquid.

  Further, the present invention projects light toward the translucent liquid passage through which the liquid flows from the light projecting portion, and receives the light transmitted through the liquid passage at the light receiving portion, and sets the amount of received light. In the liquid property change detection method for detecting a change in the property of the liquid circulated in the liquid passage based on the cross-sectional shape of the liquid passage, the light is changed when the property of the liquid is not changed. When reaching the light receiving portion and the property of the liquid changes, at least most of the light does not reach the light receiving portion on the liquid contact surface of the liquid passage due to a change in the refractive index in the liquid passage It is formed in a shape that can be refracted or reflected in a direction, and a change in the property of the liquid is detected based on a change in the amount of light received by the light receiving unit.

  The liquid property change detection device of the present invention includes a liquid passage through which a liquid flows, a light projecting unit that projects light, a light receiving unit that receives the light transmitted through the liquid channel, and a light receiving unit. A detecting unit that detects a change in the property of the liquid based on the amount of received light, and when the cross-sectional shape of the liquid passage does not change the property of the liquid, the light reaches the light receiving unit, In addition, since at least most of the light is formed in a shape that can be refracted or reflected in a direction that does not reach the light receiving unit, the amount of light received by the light receiving unit due to a change in the properties of the liquid such as mixing of bubbles Can be bigger. As a result, it is possible to improve the detection accuracy for detecting a change in the property of the liquid without complicating a processing circuit and a program for processing the light reception signal output from the light receiving unit.

  In addition, since the change in the amount of received light can be increased in the light receiving / receiving unit, it is not necessary to make adjustments during the manufacture of the device in accordance with variations in individual light receiving / emitting characteristics of the light projecting unit and the light receiving unit. Furthermore, even when the light projecting intensity of the light projecting unit and the light receiving sensitivity of the light receiving unit are lowered due to a change with time, a change in the property of the liquid can be detected without any problem. As a result, there is no need to ask a serviceman to make adjustments when the light projecting intensity and light receiving sensitivity of the light projecting unit and the light receiving unit are reduced as in the prior art.

  In the liquid property change detection method of the present invention, the light is projected from the light projecting unit toward the liquid passage through which the liquid is circulated, and the light transmitted through the liquid passage is received by the light receiving unit. When detecting a change in the property of the liquid flowing through the liquid passage based on the amount of light received, if the cross-sectional shape of the liquid passage does not change, the light is received. When the liquid property changes, at least most of the light is formed in a shape that can be refracted or reflected in a direction that does not reach the light receiving unit, and the change in the liquid property is detected. As a result, detection accuracy can be improved in the same manner. In addition, there is no need to make adjustments due to variations in individual light receiving and emitting characteristics of the light projecting unit and the light receiving unit, and adjustments due to changes over time.

  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 detection 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-forming reaction), and irradiation light for measurement containing a preselected wavelength is projected onto the dry analytical element to measure its optical density, and the substance concentration of the biochemical substance is obtained from this 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, the bubble detector 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 is a cross-sectional view of the bubble detection unit 21 corresponding to the liquid property determination apparatus of the present invention. The bubble detection unit 21 is roughly composed of a cylindrical bubble detection cell 31, a light projecting unit 32, and a light receiving unit 33.

  The bubble detection cell 31 is provided in the middle of the air tube 16. The bubble detection cell 31 is formed of a translucent material having substantially the same refractive index as the specimen 11, for example, an acrylic material, and has an inner surface serving as a liquid passage 35 through which the specimen 11 flows. Both ends of the liquid passage 35 are connected to the air tube 16. The shape of the liquid passage 35 will be described later and will not be described here.

  The light projecting unit 32 and the light receiving unit 33 are arranged so as to sandwich the bubble detection cell 31. Although not shown, the light projecting unit 32 includes a light source that projects inspection light, and a collimator lens that converts the inspection light projected from the light source into parallel light. Light is projected toward the bubble detection cell 31. As the light source of the light projecting unit 32, a single LED (light emitting diode), LEDs arranged in a matrix, an ultra-high pressure mercury lamp, a metal halide lamp, a xenon lamp, or the like is used. Then, the inspection light L projected from the light projecting unit 32 is perpendicularly incident on the light incident surface 37 of the bubble detection cell 31 facing the unit 32.

  The light receiving unit 33 is provided at a position facing the light emitting surface 38 parallel to the light incident surface 37 of the bubble detection cell 31. Although not shown, the light receiving elements are arranged as a single element or in a matrix. And a light receiving surface (not shown). The light receiving unit 33 receives the inspection light L emitted from the light emitting surface 38 and outputs a light reception signal. Note that instead of using the light projecting unit 32 and the light receiving unit 33, a pair of optical fibers including a light projecting optical fiber and a light receiving optical fiber may be used.

  Since the light projecting and light receiving units 32 and 33 are arranged so as to sandwich the liquid passage 35 in the bubble detection cell 31, the light receiving state (light reception amount) of the light receiving unit 33 is circulated in the liquid passage 35. It changes depending on whether or not the bubbles 29 are mixed in the specimen 11. Therefore, it is possible to detect the presence or absence of the bubbles 29 based on the change in the light receiving state of the light receiving unit 33. At this time, the detection accuracy increases as the change in the light receiving state due to the presence or absence of the bubbles 29 increases. Can do.

  Therefore, in this embodiment, the cross-sectional shape of the liquid passage 35 is such that the inspection light L reaches the light receiving unit 33 only when there is no air bubble mixing, and the inspection light L does not reach the light receiving unit 33 when there is air bubble mixing. The light receiving amount of the light receiving unit 33 varies greatly depending on whether or not the bubbles 29 are mixed.

  3 and 4 are cross-sectional views in which the bubble detection cell 31 is cut in a direction perpendicular to the flow direction of the specimen 11, FIG. 3 shows a state in which no bubbles are mixed, and FIG. It shows the state of being present. As shown in both figures, in this embodiment, the liquid passage 35 has a cross-sectional shape such that the liquid contact surface 35a on the side of the liquid passage 35 where the inspection light L is projected is 45 ° with respect to the optical axis O of the inspection light L. It is formed in a triangular shape so as to have an inclination angle of.

  As shown in FIG. 3, when the bubbles 29 are not mixed in the sample 11, the entire liquid passage 35 is filled with the sample 11. At this time, as described above, since the bubble detection cell 31 is formed of an acrylic material having substantially the same refractive index as that of the specimen 11, the refractive index in the bubble detection cell 31 is substantially uniform. Become. Accordingly, the inspection light L projected from the light projecting unit 32 is incident on the light incident surface 37 perpendicularly, then travels straight in the liquid passage 35 and is emitted from the light emitting surface 38 to reach the light receiving unit 33. . When receiving the inspection light L, the light receiving unit 33 outputs a light reception signal.

  As shown in FIG. 4, when the bubbles 29 mixed in the specimen 11 are mixed into the liquid passage 35, the inner diameter of the air tube 16 is small, and accordingly the width of the liquid passage 35 is narrowed. Due to the bubbles 29, the liquid passage 35 is almost air only. When the liquid passage 35 is almost air only, the refractive index in the liquid passage 35 is smaller than that of the bubble detection cell 31.

  At this time, since the liquid contact surface 35a of the liquid passage 35 serving as an interface between the bubble detection cell 31 and the air in the liquid passage 35 is inclined by 45 ° with respect to the optical axis O, the light incident surface 37 is incident. The inspection light L is totally reflected in a direction toward the surface that is different from the light exit surface 38 on the liquid contact surface 35a. In particular, since the inspection light L is parallel light, all of it is totally reflected by the liquid contact surface 35 a, and the inspection light L does not reach the light receiving unit 33. Accordingly, when the bubbles 29 are mixed into the liquid passage 35, the light reception signal output from the light receiving unit 33 is temporarily turned off. The inclination angle θ is not limited to 45 °, and the inspection light L that is smaller than the total reflection angle obtained from the refractive index of the bubble detection cell 31 and the refraction of the air and totally reflected is obtained. There is no particular limitation as long as the angle does not reach the light receiving unit 33.

  As described above, in the present embodiment, when the bubbles 29 are mixed in the sample 11 flowing through the liquid passage 35, the inspection light L does not reach the light receiving unit 33 on the liquid contact surface 35a of the liquid passage 35. Therefore, the change in the amount of light received by the light receiving unit 33 can be increased. As a result, the presence / absence of the bubbles 29 can be detected based on the light reception signal output from the light receiving unit 33. The light receiving signal output from the light receiving unit 33 is sent to the controller 40.

  The controller 40 controls driving of each part of the dispensing apparatus 10 such as the probe moving unit 19, the pressure sensor 20, the motor 23, and the light projecting unit 32 described above. The controller 40 includes a detection circuit 42 corresponding to the detection unit of the present invention.

  Based on the light reception signal output from the light receiving unit 33, the detection circuit 42 detects whether or not the bubbles 29 are mixed in the sample 11 passing through the liquid passage 35 depending on whether or not the light reception signal is turned off. To do. Further, the detection circuit 42 detects whether or not the sample 11 collected by suction has passed through the liquid passage 35 depending on whether or not the light reception signal from the light receiving unit 33 remains turned off. As a result, the detection circuit 42 determines whether or not the bubble 29 is mixed in the aspirated sample 11 depending on whether or not the light reception signal is turned off until all the aspirated sample 11 passes through the liquid passage 35. It is detected whether it is done. Note that the method of detecting whether or not all the aspirated and collected specimen 11 has passed through the liquid passage 35 is not limited to the above-described method. For example, from the number of rotations of the motor 23 (amount of movement of the plunger 25). You may make it ask.

  If the detection circuit 42 does not detect the mixing of the bubbles 29 in the sample 11, the controller 40 drives the probe moving unit 19 to move the aspiration probe 15 to the first landing position, and moves the sample to the test chip 12a. 11 is spotted. In addition, when it is detected that the bubbles 29 are mixed in the sample 11, the controller 40 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 sample 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 40 drives the probe moving unit 19 to lower the suction probe 15 at the suction standby position. Let Then, the controller 40 moves the suction probe 15 to the suction position based on the pressure signal from the pressure sensor 20. Next, the controller 40 drives the light projecting unit 32 to project the inspection light L toward the bubble detection cell 31, and then drives the motor 23 to move the plunger 25 in the syringe pump 17. The sample 11 is aspirated and collected from the aspiration probe 15.

  The specimen 11 sucked from the suction probe 15 passes through the liquid passage 35 in the bubble detection cell 31 via the air tube 16. At this time, if the bubble 29 is not mixed in the sample 11, the inspection light L projected from the light projecting unit 32 goes straight through the bubble detection cell 31 and reaches the light receiving unit 33. A light receiving signal is output from the light receiving unit 33 (see FIG. 3). Further, when the air bubbles 29 are mixed in the specimen 11, the test light L is totally reflected in the direction not reaching the light receiving unit 33 on the liquid contact surface 35 a of the liquid passage 35, so that the light received from the light receiving unit 33 is received. The signal is temporarily turned off (see FIG. 4).

  Based on the light reception signal output from the light receiving unit 33, the detection circuit 42 collects the suctioned sample depending on whether or not the received light signal is turned off before all the collected sample 11 passes through the liquid passage 35. It is detected whether or not the bubbles 29 are mixed in the sample 11.

  If the detection circuit 42 does not detect the inclusion of the bubbles 29, the controller 40 drives the probe moving unit 19 to move the suction probe 15 to the first spotting position. Next, the controller 40 drives the motor 23 to move the plunger 25 so that a predetermined amount of the specimen 11 is dropped onto the test chip 12a. Similarly, the specimen 11 is dropped on the inspection chip 12b. In addition, when the detection circuit 42 detects the mixing of the bubbles 29, the controller 40 moves the plunger 25 to discharge the sample 11, and then performs aspiration collection of the sample 11 again. Thereafter, the above-described processing is repeated until mixing of the bubbles 29 is not detected.

  As described above, in the present embodiment, when the cross-sectional shape of the liquid passage 35 is not mixed with the bubbles 29, the inspection light L projected from the light projecting unit 32 reaches the light receiving unit 33 and the bubbles 29 are mixed. When there is, the inspection light L is formed in a shape that can be totally reflected by the liquid contact surface 35a of the liquid passage 35 in a direction that does not reach the light receiving unit 33. The change in quantity can be increased. As a result, the detection accuracy for detecting the presence or absence of bubbles can be improved without complicating the processing circuit and program for processing the light reception signal output from the light reception unit 33.

  In addition, since the presence or absence of air bubbles can be detected based on whether or not the inspection light L projected from the light projecting unit 32 reaches the light receiving unit 33, the individual light receiving and emitting characteristics of both the units 32 and 33 can be detected. It is no longer necessary to make adjustments associated with variations when manufacturing the apparatus. Furthermore, even when the light projection intensity and light receiving sensitivity of both units 32 and 33 are lowered due to the change over time, the presence / absence of bubbles can be detected without any problem. As a result, when the light receiving sensitivity and light projection intensity of both the units 32 and 33 are lowered as in the prior art, there is no need to request adjustment by a service person.

  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 the above embodiment, the cross-sectional shape of the liquid passage 35 is formed in a substantially triangular shape, but the present invention is not limited to this, and the liquid contact surface on the side on which the inspection light L is projected is the inspection light. As long as L has a predetermined inclination angle (for example, 45 °) that allows total reflection, the cross-sectional shape of the liquid passage may be formed in a polygonal shape such as a quadrangle or a semicircular shape.

  Moreover, in the said embodiment, although the cross-sectional shape of the liquid channel | path 35 is formed in the shape which can totally reflect the test | inspection light L, this invention is not limited to this. For example, in the bubble detection cell 50 shown in FIG. 5, the liquid passage 51 has a liquid contact surface 51 a that is bent in a U shape in the direction of the liquid passage 51 toward the light projecting unit 32. It is formed in a triangular shape. The bending angle of the liquid contact surface 51a is not particularly limited as long as it can reflect the inspection light L in the direction not reaching the light receiving unit 33 on the liquid contact surface 51a.

  In this case, almost all of the inspection light L is reflected by the liquid contact surface 51a, but a part of the inspection light L passes through the bent portion of the liquid contact surface 51a and reaches the light receiving unit 33. At this time, the amount of the inspection light L received by the light receiving unit 33 is very small as compared with the case where the liquid passage 51 is filled with the sample 11. Therefore, even if a part of the inspection light L is transmitted, the change in the amount of light received by the light receiving unit 33 due to the presence or absence of mixing of the bubbles 29 becomes large. Can be made.

  Further, for example, like the bubble detection cell 55 shown in FIG. 6, the liquid contact surface 56 a on the side where the inspection light L of the liquid passage 56 is projected is projected in the direction toward the light receiving unit 33. It may be bent into a garlic shape. In this case, almost all of the inspection light L projected from the light projecting unit 32 is reflected again in the direction toward the light projecting unit 32. Similarly, the change in the amount of light received by the light receiving unit 33 due to the presence or absence of the bubbles 29 can be increased.

  In the above embodiment, the cross-sectional shape of the liquid passage is formed in a substantially polygonal shape, but the present invention is not limited to this, for example, as in the bubble detection cell 58 shown in FIG. The cross-sectional shape of the liquid passage 59 may be formed in a circular shape. In this case, a light projecting unit 60 and a light receiving unit 61 are provided instead of the light projecting unit 32 and the light receiving unit 33. The light projecting unit 60 is arranged at a position such that the angle formed between the optical axis of the inspection light L and the liquid contact surface 59 a is an angle at which most of the inspection light L can be reflected in a direction not reaching the light receiving unit 61. Yes. Accordingly, in this case as well, the change in the amount of light received by the light receiving unit 33 due to the presence or absence of the bubbles 29 can be increased.

  Moreover, in the said embodiment, although the cross-sectional shape of a liquid passage is formed in the shape which can reflect the test | inspection light L, this invention is not limited to this. For example, as shown in the bubble detection cell 63 in FIG. 8, the cross-sectional shape of the liquid passage 64 has a liquid contact surface 64a parallel to the optical axis O, and other liquid contact surfaces. 64b and 64c may be formed in an isosceles triangle shape having an inclination angle capable of refracting the inspection light L in the direction not reaching the light receiving unit 33 with respect to the optical axis O. In this case as well, the change in the amount of light received by the light receiving unit 33 due to the presence or absence of the bubbles 29 can be increased.

  In the above embodiment, the light projecting unit 32 is capable of projecting the inspection light L converted into parallel light. However, the present invention is not limited to this, and for example, as shown in FIG. Alternatively, a light projecting unit 64 that projects the inspection light L radially may be used. In this case, a bubble detection cell 66 having a light incident surface 65 that is curved so as to protrude in the direction toward the light projecting unit 64 is used as the bubble detection cell. The light incident surface 65 has a curvature capable of converting the inspection light L projected radially from the light projecting unit 64 into parallel light. In this way, as the light projecting unit, an LED (light emitting diode) alone or an LED in which the LEDs are arranged in a matrix, an inexpensive unit consisting of only a light source such as an ultra-high pressure mercury lamp, a metal halide lamp, a xenon lamp can be used. The manufacturing cost can be kept low.

  In the above embodiment, the light emission surface 38 of the bubble detection cell 31 is formed in a flat shape, but the present invention is not limited to this. For example, as shown in FIG. 10, as the bubble detection cell, a bubble detection cell 72 having a light emission surface 71 that is curved so as to protrude toward the light receiving unit 33 may be used. In this case, since the curved light emitting surface 71 functions as a lens, the inspection light L emitted from the light emitting surface 71 can be condensed on the light receiving surface (not shown) of the light receiving unit 33. it can. Thereby, since the condensing efficiency to the light receiving unit 33 can be improved, the change in the amount of light received by the light receiving unit 33 due to the presence or absence of the bubbles 29 can be further increased.

  In the embodiment described with reference to FIG. 10, the light projecting unit 32 that projects the inspection light L converted into parallel light is used. However, the present invention is not limited to this, and the inspection is not limited thereto. You may use the light projection unit 64 (refer FIG. 9) which projects the light L radially. In this case, for example, as shown in FIG. 11, by using a substantially cylindrical bubble detection cell 75 as the bubble detection cell, the inspection light L projected radially from the light projecting unit 64 is converted into parallel light. Condensing efficiency to the light receiving unit 33 can be improved while converting. Instead of using the substantially cylindrical bubble detection cell 75, although not shown, a bubble detection cell having the above-described light incident surface 65 (see FIG. 9) and light emitting surface 71 (see FIG. 10) is used. May be.

  In the above embodiment, a cylindrical body made of an acrylic material or the like is used as the bubble detection cell 31, but the present invention is not limited to this. For example, as shown in FIG. 12, the first cylinder 80 having the liquid passage 79, the second cylinder 81 covering the outer surface of the first cylinder 80, and the two cylinders 80, 81 are filled. A bubble detection cell 83 composed of the liquid 82 may be used. In this case, both cylinders 80 and 81 are formed of an acrylic material or the like having substantially the same refractive index as that of the specimen 11. In addition, a liquid 82 having substantially the same refractive index as that of the specimen 11 is used as the liquid 82. And the 1st cylinder 80 is formed so that the cross-sectional shape of the liquid channel | path 79 may become the same shape as the above-mentioned liquid channel | path 35 (refer FIG. 3). Thereby, similarly to each of the above embodiments, the change in the amount of light received by the light receiving unit 33 due to the presence or absence of the bubbles 29 can be increased.

  Moreover, in the said embodiment, although test | inspection light is projected on the cell 31 for bubble detection provided in the middle of the air tube 16, this invention is not limited to this. For example, the inspection light L is projected onto a liquid pipe such as an air tube which is formed of a light-transmitting material having substantially the same refractive index as that of the specimen 11 and has the same shape as the liquid passage 35 described above. The presence / absence of contamination may be detected.

  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. 13, components having the same functions as those described in the above-described dispensing apparatus 10 are given 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 detection 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 detection 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 is aspirated. The bubble detection 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 detection unit 98 is the same as the above-described bubble detection unit 21 (see FIG. 2), and includes a bubble detection cell 100, a light projecting unit 101, a light receiving unit 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, in the bubble detection unit 98, inspection light is projected from the light projecting unit 101 toward the bubble detection cell 100. Therefore, based on the change in the amount of the inspection light received by the light receiving unit 102, it is possible to detect the presence or absence of the bubbles 29 in the water 85 flowing through the liquid pipe 94. The bubble detector 21 may be used in combination to detect the presence or absence of the bubbles 29 in the water 85. And if mixing of the bubble 29 is detected, after the plunger 25 is moved similarly and the water 85 is discharged | emitted, the water 85 will be suction-collected again.

  If the air bubbles 29 are not mixed in the supplied water 85, 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 above-described dispensing apparatus 10, the sample 11 is aspirated, the bubble detection unit 21 detects the presence or absence of the bubbles 29 in the sample 11, 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.

  In the above embodiment, the bubble detection unit 21 has been described as an example incorporated in the dispensing device 10 of the biochemical analyzer, but the present invention is not limited to this, For example, the present invention can be applied to various liquids that are circulated in various devices such as a device for homogenizing a trace amount of liquid, an artificial dialysis machine, a medical chemical injection device, an immunological test device, an inkjet printer, and a coating device. 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 a foreign substance is mixed in various liquids circulated in the liquid passage, the refractive index in the liquid passage 35 changes as in the case where the bubbles 29 are mixed. Therefore, the present invention can also be used to detect changes in the properties of various liquids circulated in the liquid passages in the various devices and plants described above.

The perspective view of a dispensing apparatus is shown. A sectional view of a bubble detection part of a dispensing device is shown. It is sectional drawing which cut | disconnected the cell for bubble detection in the direction perpendicular | vertical with respect to the distribution direction of a test substance, and is the figure which showed the state without bubble mixing. It is sectional drawing which cut | disconnected the cell for bubble detection in the direction perpendicular | vertical with respect to the distribution direction of a sample, and is the figure which showed the state with bubble mixing. It is sectional drawing of the cell for bubble detection of other embodiment which has the liquid-contact surface bent in the shape of a dogleg shape in the direction which goes to a light projection unit. It is sectional drawing of the cell for bubble detection of other embodiment which has the liquid-contact surface bent in the shape of a dogleg shape in the direction which goes to a light reception unit. It is sectional drawing of the cell for bubble detection of other embodiment which formed the cross-sectional shape of the liquid path in the circular shape. It is sectional drawing of the cell for bubble detection of other embodiment which has the liquid path of the cross-sectional shape which can refract in the direction which does not make test | inspection light reach | attain a light-receiving unit. It is sectional drawing of the cell for bubble detection of other embodiment which has the light-incidence surface curved so that it might become convex in the direction which goes to a light projection unit. It is sectional drawing of the cell for bubble detection of other embodiment which has the light-projection surface curved so that it might become convex in the direction which goes to a light reception unit. It is sectional drawing of the cell for bubble detection of other embodiment formed in the cylindrical form. It is sectional drawing of the cell for bubble detection of other embodiment comprised from two cylinders and the liquid with which it filled between both cylinders. 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 Aspiration probe 16 Air tube 21 Bubble detection part 31 Bubble detection cell 32 Light projection unit 33 Light reception unit 35 Liquid passage 35a Liquid contact surface 42 Detection circuit

Claims (11)

The light-transmitting liquid passage through which the liquid flows, the light projecting unit that projects light toward the liquid channel, the light receiving unit that receives the light that has passed through the liquid channel, and the light receiving unit receive the light. In the liquid property change detecting device, the detection unit detects a change in the property of the liquid flowing in the liquid passage based on the amount of received light.
When the cross-sectional shape of the liquid passage does not change the property of the liquid, the light reaches the light receiving unit, and when the property of the liquid changes, the refractive index in the liquid passage changes. Accordingly, the liquid property change detecting device is formed in a shape capable of being refracted or reflected in a direction in which at least most of the light does not reach the light receiving portion on the liquid contact surface of the liquid passage.   The liquid property change detection device according to claim 1, wherein the light is parallel light before reaching the liquid passage. The liquid passage has a substantially polygonal cross-sectional shape,
The liquid contact surface of the liquid passage on the side where the light is projected from the light projecting portion has an inclination angle at which the light can be refracted or reflected in a direction not reaching the light receiving portion with respect to the optical axis of the light. The liquid property change detecting device according to claim 1, wherein the liquid property change detecting device is provided. The liquid passage is formed so that the cross-sectional shape is substantially circular,
The light projecting unit is disposed at a position where an angle formed between the optical axis of the light and a liquid contact surface of the liquid passage is an angle at which most of the light can be refracted or reflected in a direction not reaching the light receiving unit. The liquid property change detecting device according to claim 1, wherein the liquid property change detecting device is a liquid property changing device.   The liquid contact surface of the liquid passage is an inner surface of a translucent cylindrical body having a light incident surface facing the light projecting portion and a light emitting surface facing the light receiving portion. Item 5. The liquid property change detection device according to any one of Items 1 to 4. The light projecting unit projects the light radially,
The liquid property change according to claim 5, wherein the light incident surface is curved so as to be convex in a direction toward the light projecting unit, and the light projected radially is converted into parallel light. Detection device.   7. The light emitting surface is curved so as to be convex in a direction toward the light receiving portion, and the light emitted from the light emitting surface is condensed on the light receiving portion. Liquid property change detection device.   The liquid property change detecting device according to claim 5, wherein the cylindrical body has substantially the same refractive index as the liquid.   The liquid property change detection device according to claim 8, wherein the light projecting unit and the light receiving unit are disposed so as to sandwich the liquid passage.   The liquid property change detection device according to any one of claims 1 to 9, wherein the detection unit detects whether or not bubbles are mixed in the liquid. Light is projected from the light projecting portion toward the translucent liquid passage through which the liquid is circulated, and the light that has passed through the liquid passage is received by the light receiving portion, and the liquid passage is based on the amount of light received. In the liquid property change detection method for detecting a change in the property of the liquid flowing through
When the property of the liquid does not change, the cross-sectional shape of the liquid passage causes the light to reach the light receiving unit, and when the property of the liquid changes, the refractive index in the liquid passage changes. Accordingly, at least most of the light is formed in a shape that can be refracted or reflected in a direction not reaching the light receiving portion on the liquid contact surface of the liquid passage, and the liquid is changed based on the change in the amount of light received by the light receiving portion. A method for detecting a change in property of a liquid, comprising detecting a change in property of the liquid.

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