JP2011163771A - Syringe pump, dispensing device, and automatic analyzer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a syringe pump avoiding increase of sizes of a dispensing device and an automatic analyzer, and also to provide the dispensing device and automatic analyzer provided with the same. <P>SOLUTION: The syringe pump 62 has: a syringe 63 in which a discharge opening 63a and a suction opening 63b are formed; a large diameter piston 64 having a through-hole 64a along the longitudinal direction with the one end of the longitudinal direction inserted into the syringe; and a small diameter piston 65 inserted into the through-hole and movable freely in and out of the edge part positioned inside the syringe in the through hole. The dispensing device and automatic analyzer are provided with the syringe pump. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a syringe pump used for liquid dispensing, a dispensing device that dispenses liquid using the syringe pump, and an automatic analyzer that includes the dispensing device and analyzes a sample.

  2. Description of the Related Art Conventionally, an automatic analyzer for analyzing a sample analyzes the components of the sample by reacting the sample with a reagent and measuring the optical characteristics of the reaction solution (see, for example, Patent Document 1). At this time, the automatic analyzer dispenses a predetermined amount of sample and reagent by a reagent dispensing device having a dispensing probe and a sample dispensing device.

JP-A-11-230970

  By the way, the automatic analyzer disclosed in Patent Literature 1 performs analysis by diluting a specimen in order to reduce the amount of reagent used in accordance with reduction in running cost. For this reason, the automatic analyzer of Patent Document 1 uses two syringe pumps, ie, a syringe pump for sample dispensing and a syringe pump for supplying dilution water, and the dispensing device and the automatic analyzer are increased in size. There was a problem.

  The present invention has been made in view of the above, and provides a syringe pump capable of avoiding an increase in size of a dispensing device and an automatic analyzer, and a dispensing device and an automatic analyzer equipped with the syringe pump. The purpose is to do.

  In order to solve the above-described problems and achieve the object, the syringe pump of the present invention has a syringe in which a liquid discharge port and a suction port are formed, a through hole along the longitudinal direction, and a longitudinal direction. One end has a large-diameter piston inserted into the syringe, and a small-diameter piston that is inserted through the through-hole and can protrude and retract from an end located inside the syringe of the through-hole.

  In the syringe pump according to the present invention, the small diameter piston is longer than the large diameter piston.

  In the syringe pump of the present invention, in the above invention, the syringe is configured such that the discharge port is formed at a front end in the discharge movement direction of the large-diameter piston and the suction port is formed at a rear end side. Features.

  In order to solve the above-described problems and achieve the object, the dispensing device of the present invention sucks a liquid sample into a pipe, and dispenses the sucked liquid sample by discharging a predetermined amount. A dispensing probe connected by piping, the syringe pump according to any one of claims 1 to 3, a drive motor for driving the large-diameter piston and the small-diameter piston of the syringe pump, Control means for controlling the suction of the liquid from the suction port and the discharge of the liquid from the discharge port by controlling the driving of the large-diameter piston or the small-diameter piston by a drive motor. .

  Further, the dispensing device of the present invention is the above invention, wherein the dispensing device is driven via a large-diameter clutch that transmits and shuts off the rotational force of the drive motor to the syringe pump, and the large-diameter A large-diameter ball screw that moves the piston along the axial direction of the piston, a small-diameter clutch that transmits and shuts off the rotational force of the drive motor to the syringe pump, and a transmission means. A small-diameter ball screw that moves along the axial direction, and the control means transmits the rotational force of the drive motor to the large-diameter ball screw or the small-diameter ball screw by the large-diameter clutch or the small-diameter clutch. The movement of the large-diameter piston or the small-diameter piston is controlled by blocking.

  In order to solve the above-described problems and achieve the object, an automatic analyzer of the present invention includes a sample dispensing device for dispensing a sample and a reagent dispensing device for dispensing a reagent, An automatic analyzer for analyzing a component of the specimen by reacting the specimen with the reagent, wherein the specimen dispensing apparatus or the reagent dispensing apparatus is configured using the dispensing apparatus. And

  According to the present invention, the dilution water is supplied by the large-diameter piston having the insertion port, and the liquid sample including the specimen and the reagent is dispensed by the small-diameter piston inserted into the large-diameter piston so that the tip can be retracted from the insertion port. It is possible to provide a syringe pump capable of avoiding an increase in size of the dispensing device and the automatic analyzer, and a dispensing device and an automatic analyzer including the syringe pump.

FIG. 1 is a cross-sectional front view of a syringe pump of the present invention used in a dispensing device. FIG. 2 is a perspective view of a large-diameter piston constituting the syringe pump of FIG. FIG. 3 is a front view showing a section of a part of a pump unit obtained by unitizing the syringe pump of FIG. 1 together with a drive motor and the like. FIG. 4 is a schematic configuration diagram of a dispensing apparatus according to the embodiment of the present invention including the pump unit shown in FIG. FIG. 5 is a schematic configuration diagram of an analyzer according to the embodiment of the present invention provided with the dispensing apparatus shown in FIG. FIG. 6 is a view showing a main part of the pump unit showing a state where the large-diameter piston is retracted from the initial position and the ion exchange water is sucked into the syringe up to the maximum amount. FIG. 7 is a view showing a main part of the pump unit showing a state in which the suction port of the syringe is closed by the large-diameter piston and the communication with the discharge port is blocked. FIG. 8 is a diagram showing a main part of the pump unit for explaining a state in which air for blocking the mixing of the specimen and the ion exchange water is sucked into the dispensing probe. FIG. 9 is a view showing a main part of the pump unit showing a state in which the small-diameter piston is retracted in order to suck the sample from the dispensing probe. FIG. 10 is a view showing a main part of the pump unit showing a state in which the large-diameter piston and the small-diameter piston are advanced in order to dilute the specimen by discharging the aspirated specimen together with the washing water from the dispensing probe.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a dispensing device, a dispensing probe cleaning method for a dispensing device, and an automatic analyzer according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

  FIG. 1 is a cross-sectional front view of a syringe pump of the present invention used in a dispensing device. FIG. 2 is a perspective view of a large-diameter piston constituting the syringe pump of FIG.

  The syringe pump 62 is a pump that sucks and discharges ion-exchanged water that transmits pressure in a later-described dispensing device, washing water for the dispensing probe, and ion-exchanged water that is used as sample and reagent dilution water. As shown in FIG. 2, the syringe 63 has a large-diameter piston 64 that is slidably inserted into the syringe 63, and a small-diameter piston 65 that is slidably inserted into the large-diameter piston 64.

  As shown in FIG. 1, in the syringe 63, a discharge port 63a for discharging ion exchange water is formed at the front end in the discharge movement direction of the large diameter piston 64, and on the rear end side in the discharge movement direction of the large diameter piston 64, A suction port 63b for ion-exchanged water is formed. A discharge fitting 63c is attached to the discharge port 63a, and a suction fitting 63d is attached to the suction port 63b.

  As shown in FIG. 1, the large-diameter piston 64 has a through hole 64 a along the longitudinal direction, and one end in the longitudinal direction is inserted into the syringe 63. As shown in FIG. 2, the large-diameter piston 64 has an insertion port 64c formed at the center of the front end face 64b. The large-diameter piston 64 has a concave portion 64h formed on the side surface of the flange 64g at the rear end.

  As shown in FIG. 1, the small-diameter piston 65 has a pressing flange 65 b formed at the rear end of the piston main body 65 a that is longer than the large-diameter piston 64 in the discharge movement direction. A recess 65c is formed on the side surface of the pressing flange 65b. The small-diameter piston 65 is arranged coaxially with the piston axis Ap of the large-diameter piston 64 by inserting the tip of the piston main body 65a so as to be able to protrude and retract from the insertion port 64c.

  At this time, the syringe 63, the large-diameter piston 64, and the piston main body 65a are manufactured by precision machining ceramic or the like, thereby ensuring mutual liquid-tightness and slidability.

  FIG. 3 is a front view showing a section of a part of a pump unit obtained by unitizing the syringe pump of FIG. 1 together with a drive motor and the like. As shown in FIG. 3, the syringe pump 62 having the two pistons 64 and 65 described above is united by being attached to an attachment structure 61 together with a drive motor 66 and the like as a pump unit 60. That is, the pump unit 60 includes a syringe pump 62, a drive motor 66, a large diameter ball screw 68, and a small diameter ball screw 71.

  Here, FIG. 3 shows the initial positions of the large-diameter piston 64 and the small-diameter piston 65 when the dispensing device to be described later starts dispensing of the specimen and the reagent, and the syringe pump 62 is a discharge port of the syringe 63. 63a communicates with the suction port 63b.

  As shown in FIG. 3, the drive motor 66 is attached to an attachment wall 61 a erected on the attachment structure 61 and drives the syringe pump 62.

  As shown in FIG. 3, the large-diameter ball screw 68 includes a screw shaft 68 a installed between the large-diameter clutch 67 attached to the attachment wall 61 a and the support wall 61 b, and a protrusion provided on the nut 68 b is formed by a protrusion provided on the nut 68 b. It is fitted with a recess 64h formed in the flange 64g. The large-diameter ball screw 68 is driven by a drive motor 66 via a large-diameter clutch 67, and moves the large-diameter piston 64 along the piston axis Ap direction by a nut 68b.

  As shown in FIG. 3, the small-diameter ball screw 71 has a screw shaft 71a installed between the support wall 61b and the support wall 61c, and a protrusion provided on the nut 71b and a recess 65c formed on the flange 64g of the small-diameter piston 65. It is mated. The small-diameter ball screw 71 is driven by the drive motor 66 via the small-diameter clutch 69 and the belt transmission device 70, and moves the small-diameter piston 65 along the direction of the piston axis Ap.

  Here, as the large-diameter clutch 67 and the small-diameter clutch 69, an electromagnetic clutch is used that transmits or blocks the rotational force of the drive motor 66 to the large-diameter ball screw 68 or the small-diameter ball screw 71 when the power is turned on / off. In the belt transmission device 70, a belt 70 b is wound between a pulley 70 a attached to the output shaft 69 a of the small diameter clutch 69 and a pulley 70 c attached to the screw shaft 71 a of the small diameter ball screw 71.

  FIG. 4 is a schematic configuration diagram of a dispensing apparatus according to the embodiment of the present invention including the pump unit shown in FIG. A dispensing apparatus including the pump unit 60 configured as described above will be described below with reference to FIG.

  The dispensing apparatus shown in FIG. 4 is a specimen dispensing apparatus for dispensing a specimen. As shown in FIG. 4, a column 5a, an arm 5b, a specimen dispensing probe 5c, and a liquid level detection means (not shown) are provided. In addition, a probe driving unit 51, a tank 55, a dispensing control unit 56, and a pump unit 60 are provided.

  As shown in FIG. 4, the support column 5a supports the proximal end side of the arm 5b, and a sample dispensing probe 5c is provided downward on the distal end side of the arm 5b. The specimen dispensing probe 5c is connected to a discharge fitting 63c provided on the syringe 63 of the syringe pump 62 by a pipe 52, and dispenses the specimen and discharges ion exchange water.

  In addition, the liquid level detection means is configured so that the liquid level of the sample stored in the sample container 4 (see FIG. 5) is between the sample dispensing probe 5c and the electrode disposed in the vicinity of the sample container 4 during sample dispensing. It is detected by the change in electrostatic capacity.

  The probe driving unit 51 is a driving unit that rotates the support column 5a about the axis and moves it up and down.

  As shown in FIG. 4, the tank 55 contains ion exchange water W, and is connected to a suction fitting 63 d provided on the syringe 63 of the syringe pump 62 by a pipe 53. Here, the pipe 53 is provided with a pump 54 in the middle, and is filled with ion-exchanged water W pumped by the pump 54 together with the syringe 63 and the pipe 52.

  The dispensing control unit 56 includes a CPU and the like, and controls the driving motor 66, the large diameter clutch 67, and the small diameter clutch 69 of the pump unit 60 in addition to the probe driving unit 51 and the pump 54, thereby controlling the sample dispensing apparatus 5. Control the operation. In particular, the dispensing control unit 56 controls the drive motor 66, and controls transmission and interruption of the rotational force of the drive motor 66 by the large diameter clutch 67 and the small diameter clutch 69 to the large diameter ball screw 68 or the small diameter ball screw 71. The movement of the large-diameter piston 64 and the small-diameter piston 65 is controlled to control the suction of the ion exchange water from the suction port 63b, the discharge of the ion exchange water from the discharge port 63a, and the discharge amount of the ion exchange water.

  Next, an automatic analyzer equipped with the sample dispensing device 5 will be described. FIG. 5 is a schematic configuration diagram of an analyzer according to the embodiment of the present invention provided with the dispensing apparatus shown in FIG.

  As shown in FIG. 5, the automatic analyzer 1 includes a sample table 3, a sample dispensing device 5, a cuvette wheel 8, a photometric device 10, a washing device 11, a stirring device 12, a reagent dispensing device 13, and a reagent table on a housing 2. 14 and a reading device 16 are provided.

  The sample table 3 is rotated in the direction of the arrow shown in FIG. 5 by the driving means, and a plurality of storage chambers 3a are provided on the outer periphery at regular intervals along the circumferential direction. In each storage chamber 3a, a sample container 4 storing a sample is detachably stored.

  The cuvette wheel 8 is rotated in the direction of the arrow shown in FIG. 5 by a driving means different from the sample table 3, and a plurality of recesses 8a for arranging the reaction vessels 9 along the circumferential direction are provided at equal intervals on the outer periphery. . The cuvette wheel 8 is formed with openings through which the measurement light passes on both radial sides of each recess 8a. The cuvette wheel 8 rotates clockwise (1 round-1 reaction vessel) / 4 minutes in one cycle and rotates counterclockwise by one of the recesses 8a in four cycles. On the outer periphery of the cuvette wheel 8, a photometric device 10, a cleaning device 11, and a stirring device 12 are arranged.

  The reaction container 9 is a very small cuvette having a capacity of several μL to several tens μL, and is made of a transparent material that transmits 80% or more of the light contained in the analysis light emitted from the light source of the photometric device 10, for example, heat resistant glass. Synthetic resins such as glass, cyclic olefin and polystyrene are used.

  As shown in FIG. 5, the photometric device 10 is disposed near the outer periphery of the cuvette wheel 8, and a light source that emits analysis light for analyzing the liquid held in the reaction vessel 9 and the analysis light that has passed through the liquid are dispersed. And a light receiver for receiving light. In the photometric device 10, the light source and the light receiver are arranged at positions facing each other in the radial direction with the concave portion 8 a of the cuvette wheel 8 interposed therebetween.

  The cleaning device 11 has a discharge means for discharging the liquid and the cleaning liquid from the reaction vessel 9 and a cleaning liquid dispensing means. The cleaning device 11 dispenses the cleaning liquid after discharging the liquid after the photometry from the reaction vessel 9 after the completion of the photometry. The cleaning device 11 cleans the inside of the reaction vessel 9 by repeating the dispensing and discharging operations of the cleaning liquid a plurality of times. The reaction container 9 washed in this way is used again for analysis of a new specimen.

  The stirrer 12 stirs the specimen or reagent dispensed in the reaction vessel 9 with, for example, a stirrer. However, when it is necessary to stir the liquid held in the reaction vessel 9 in a non-contact manner, the stirring device 12 attaches a surface acoustic wave element to the reaction vessel 9 and stirs it with sound waves generated by the surface acoustic wave element. May be.

  The reagent dispensing device 13 is a means for dispensing a reagent into a plurality of reaction containers 9 held by the cuvette wheel 8, and sequentially reacts the reagents from a predetermined reagent container 15 of the reagent table 14 as shown in FIG. Dispense into container 9. The reagent dispensing device 13 includes a support, an arm 13b, and a reagent dispensing probe, and also includes a liquid level detection unit (not shown), and is configured in the same manner as the sample dispensing device 5.

  Here, the housing 2 is provided with a cleaning tank 2a for cleaning the sample dispensing probe 5c of the sample dispensing device 5 on the movement locus of the sample dispensing probe 5c between the sample table 3 and the cuvette wheel 8, A cleaning tank 2 b for cleaning the dispensing probe of the reagent dispensing device 13 is provided on the movement locus of the dispensing probe between the cuvette wheel 8 and the reagent table 14.

  The reagent table 14 is rotated in the direction of the arrow shown in FIG. 5 by driving means different from the sample table 3 and the cuvette wheel 8, and a plurality of storage chambers 14a formed in a fan shape are provided along the circumferential direction. A reagent container 15 is detachably stored in each of the storage chambers 14a. Each of the plurality of reagent containers 15 is filled with a predetermined reagent corresponding to the inspection item, and an information recording medium (not shown) such as a bar code label on which information related to the stored reagent is recorded is attached to the outer surface.

  The reading device 16 reads information such as the reagent type, lot, and expiration date recorded on the information recording medium attached to the reagent container 15 on the outer periphery of the reagent table 14 and outputs the information to the control unit 17.

  As the control unit 17, for example, a microcomputer having a storage function for storing analysis results is used, and the sample table 3, the sample dispensing device 5, the cuvette wheel 8, the photometric device 10, the washing device 11, the stirring device 12, The reagent dispensing device 13, the reagent table 14, the reading device 16, the input unit 18, the output unit 19, and the like are connected. The control unit 17 controls the operation of each unit of the automatic analyzer 1, and stops the analysis work based on the information read from the information recording medium when the reagent lot, expiration date, or the like is out of the set range. The automatic analyzer 1 is controlled or a warning is issued to the operator. And the control part 17 has the analysis part 17a, as shown in FIG.

  The analysis unit 17a stores information related to analysis, such as identification numbers of samples and reagents input from the host computer, analysis items, necessity of retesting, and the like. Further, the analysis unit 17a analyzes the component concentration of the specimen from the absorbance (optical characteristics) of the reaction liquid of the specimen and the reagent in the cuvette C obtained based on the light quantity measured by the photometric device 10, and stores the analysis result. To do.

  The input unit 18 is a part for performing input operations such as the number of specimens and examination items to the control unit 17, and for example, a keyboard or a mouse is used.

  The output unit 19 is a part that displays analysis contents including an analysis result, an alarm, and the like. For example, a display panel or the like is used. Here, the output unit 19 may use a speaker that notifies an alarm or the like by voice.

  In the automatic analyzer 1 configured as described above, the reagent dispensing device 13 sequentially dispenses the reagent from the reagent container 15 into the plurality of reaction containers 9 conveyed along the circumferential direction by the rotating cuvette wheel 8. . The reaction container 9 into which the reagent has been dispensed is transported along the circumferential direction by the cuvette wheel 8, and the specimens are sequentially dispensed from the plurality of specimen containers 4 held on the specimen table 3 by the specimen dispensing apparatus 5.

  Then, the reaction container 9 into which the specimen has been dispensed is conveyed to the stirring device 12 by the cuvette wheel 8, and the dispensed reagent and the specimen are sequentially stirred and reacted. The reaction container 9 holding the reaction solution in which the sample and the reagent have reacted in this way passes through the photometric device 10 when the cuvette wheel 8 is rotated again, and the analysis light emitted from the light source is transmitted. At this time, the analysis light transmitted through the reaction vessel 9 is measured by the light receiving unit, and the component concentration and the like are analyzed by the control unit 17 based on the absorbance. In addition, the reaction container 9 that has been analyzed is washed by the washing device 11 and then used again for analyzing the specimen.

  Here, when the analysis is started when the power is turned on, the automatic analyzer 1 initializes the entire apparatus, cleans the reaction container 9, the sample dispensing probe 5c, and the reagent dispensing probe, and then starts an analysis operation. At this time, the syringe pump 62 is used when the sample is sucked from the sample container 4 executed by the sample dispensing device 5 and the sucked sample is discharged together with ion-exchanged water from the dispensing probe to the reaction container 9 to dilute and dispense the sample. The operation of is described below with reference to the pump unit shown in FIGS.

  FIG. 6 is a view showing a main part of the pump unit showing a state where the large-diameter piston is retracted from the initial position and the ion exchange water is sucked into the syringe up to the maximum amount. FIG. 7 is a view showing a main part of the pump unit showing a state in which the suction port of the syringe is closed by the large-diameter piston and the communication with the discharge port is blocked. FIG. 8 is a diagram showing a main part of the pump unit for explaining a state in which air for blocking the mixing of the specimen and the ion exchange water is sucked into the dispensing probe. FIG. 9 is a view showing a main part of the pump unit showing a state in which the small-diameter piston is retracted in order to suck the sample from the dispensing probe. FIG. 10 is a view showing a main part of the pump unit showing a state in which the large-diameter piston and the small-diameter piston are advanced in order to dilute the specimen by discharging the aspirated specimen together with the washing water from the dispensing probe. 6 to 10 omit the pipes 52 and 53 without showing them.

  First, the sample dispensing device 5 drives the probe driving unit 51, moves the sample dispensing probe 5c to the position of the washing tank 2a, and drives the pump 54 to pump ion exchange water as washing water to the syringe 63. . At this time, since the large-diameter piston 64 is in the initial position, the discharge port 63a and the suction port 63b of the syringe 63 communicate with each other as shown in FIGS. Therefore, the ion-exchanged water pressure-fed to the syringe 63 is discharged from the sample dispensing probe 5c to the cleaning tank 2a through the pipe 52, and the sample dispensing probe 5c is washed.

  During the cleaning of the sample dispensing probe 5c, the dispensing control unit 56 drives the large diameter piston 64 by the drive motor 66 and retracts the large diameter piston 64 to the maximum suction amount position as shown in FIG. The ion exchange water W is sucked into the syringe 63 to the maximum amount. At this time, the dispensing control unit 56 transmits the rotational force of the drive motor 66 to the large-diameter ball screw 68 by setting the large-diameter clutch 67 to “contact”, and also sets the small-diameter clutch 69 to “disengagement”. Is transmitted to the small-diameter ball screw 71.

  Next, the specimen dispensing device 5 drives the drive motor 66 to advance the large-diameter piston 64 to a position where the suction port 63b is blocked as shown in FIG. Stop pumping. At this time, the dispensing control unit 56 reverses the rotation direction of the drive motor 66 to the case shown in FIG. At the same time, the small-diameter clutch 69 is “disconnected” to interrupt the transmission of the rotational force of the drive motor 66 to the small-diameter ball screw 71.

  Next, the sample dispensing device 5 drives the drive motor 66 to slightly retract the small-diameter piston 65 as shown in FIG. 8, and aspirates air into the sample dispensing probe 5c. At this time, since the suction port 63 b is blocked by the large diameter piston 64, the ion exchange water does not flow into the syringe 63. In addition, the dispensing control unit 56 reverses the rotation direction of the drive motor 66 as shown in FIG. 7 and transmits the rotational force of the drive motor 66 to the large-diameter ball screw 68 by disengaging the large-diameter clutch 67. And the rotational force of the drive motor 66 is transmitted to the small-diameter ball screw 71 by setting the small-diameter clutch 69 to “contact”.

  Here, the air sucked into the sample dispensing probe 5c blocks the contact between the sample to be sucked and the ion-exchanged water, so the amount thereof is small. The reverse amount ΔL may be small.

  Thereafter, the sample dispensing device 5 drives the probe driving unit 51 to move the sample dispensing probe 5c to the sample aspirating position on the sample table 3. Then, the sample dispensing device 5 drives the probe driving unit 51 to lower the sample dispensing probe 5c, and enters the predetermined amount of sample from the liquid level detected by the liquid level detection means at the lower end of the sample dispensing probe 5c. Let

  Next, the sample dispensing device 5 drives the drive motor 66 to retract the small diameter piston 65 by an amount corresponding to the amount of sample to be dispensed, as shown in FIG. At this time, the dispensing control unit 56 makes the rotation direction of the drive motor 66 the same as in the case shown in FIG. Is transmitted to the small-diameter ball screw 71 while the small-diameter clutch 69 is set to “contact”. As a result, the sample dispensing device 5 sucks the volume Vs sample into the sample dispensing probe 5c. Here, the volume of ion-exchanged water present in the syringe 63 shown in FIG.

  After sample aspiration, the sample dispensing device 5 drives the probe driving unit 51 to raise the sample dispensing probe 5c, and then moves the sample dispensing probe 5c to the sample ejection position of the cuvette wheel 8. Then, the sample dispensing device 5 drives the probe driving unit 51 to lower the sample dispensing probe 5c by a predetermined amount.

  Next, the specimen dispensing device 5 drives the drive motor 66 to advance the large-diameter piston 64 and the small-diameter piston 65 as shown in FIG. At this time, the suction port 63 b is closed by the large diameter piston 64. For this reason, the syringe pump 62 sends ion exchange water corresponding to the amount of movement of the large diameter piston 64 and the small diameter piston 65 from the discharge fitting 63c to the specimen dispensing probe 5c through the pipe 52.

  As a result, if the volume of the ion-exchanged water W existing in the syringe 63 shown in FIG. 10 is Vi2, the sample dispensing probe 5c discharges the sample of the volume Vs sucked by the movement of the small diameter piston 65 to the reaction container 9. At the same time, a volume of (Vi 1 −Vi 2 −Vs) ion exchange water is discharged into the reaction vessel 9. As a result, the specimen discharged into the reaction container 9 is diluted with ion-exchanged water that exceeds the amount of specimen discharged together. Note that the specimen and the ion-exchanged water can be discharged by the pump 54 of the specimen dispensing apparatus 5, but it is preferable to use the syringe pump 62 in consideration of the accuracy of the discharge amount.

  When the large-diameter piston 64 and the small-diameter piston 65 are advanced, the dispensing control unit 56 reverses the rotation direction of the drive motor 66 to that shown in FIG. As a result, the rotational force of the drive motor 66 is transmitted to the large diameter ball screw 68 and the small diameter ball screw 71.

  After diluting and discharging the sample in this manner, the sample dispensing device 5 drives the probe driving unit 51 to return the sample dispensing probe 5c to the cleaning tank 2a, thereby washing the sample dispensing probe 5c. Then, after the large-diameter piston 64 is retracted to the maximum suction amount position shown in FIG. 6 and the ion-exchanged water W is sucked up to the maximum amount in the syringe 63, the sample is continuously diluted or dispensed.

  As described above, the syringe pump 62 supplies the ion exchange water W by the large-diameter piston 64 having the insertion port 64c, and the small-diameter piston 65 is inserted into the large-diameter piston 64 so that the tip can be retracted from the insertion port 64c. Samples and reagents can be dispensed. For this reason, the sample dispensing device 5, the reagent dispensing device 13 and the automatic analyzer 1 are provided with a syringe pump 62 capable of dispensing a liquid sample containing a sample and a reagent alone and supplying ion-exchanged water W as dilution water. Since it is provided, the size of the apparatus can be avoided and the degree of freedom in design can be improved.

  In the above embodiment, the case where the syringe pump 62 is used in the sample dispensing device 5 has been described. However, when the syringe pump 62 is used in the sample dispensing device 5, the syringe pump 62 is used in the sample dispensing device 5. Similarly to the above, it can be used for reagent dispensing and dilution dispensing, as well as for cleaning of dispensing probes after reagent dispensing, and dilution dispensing of detergents.

  As described above, the syringe pump of the present invention is useful for independently dispensing a liquid sample containing a specimen or a reagent and supplying dilution water, and is used particularly in a dispensing device and an automatic analyzer. This is suitable for downsizing the apparatus.

DESCRIPTION OF SYMBOLS 1 Automatic analyzer 2 Housing 3 Specimen table 4 Specimen container 5 Specimen dispensing device 8 Cuvette wheel 9 Reaction vessel 10 Photometric device 11 Washing device 12 Stirrer 13 Reagent dispensing device 14 Reagent table 15 Reagent container 16 Reading device 17 Control part 18 Input unit 19 Output unit 60 Pump unit 61 Mounting structure 62 Syringe pump 63 Syringe 63a Discharge port 63b Suction port 64 Large diameter piston 64a Through hole 64b Insertion port 65 Small diameter piston 66 Drive motor 67 Large diameter clutch 68 Large diameter ball screw 69 Small diameter clutch 70 Belt transmission device 71 Small-diameter ball screw Ap Piston shaft

Claims (6)

A syringe formed with a liquid discharge port and a suction port;
A large-diameter piston having a through-hole along the longitudinal direction and having one end in the longitudinal direction inserted into the syringe;
A small-diameter piston that is inserted through the through-hole and can protrude and retract from an end located inside the syringe of the through-hole,
A syringe pump characterized by comprising:   The syringe pump according to claim 1, wherein the small-diameter piston is longer than the large-diameter piston.   The syringe pump according to claim 2, wherein the syringe has the discharge port formed at a front end in the discharge movement direction of the large-diameter piston, and the suction port formed at a rear end side. A dispensing device that sucks a liquid sample into a pipe and discharges the sucked liquid sample to dispense a predetermined amount,
A dispensing probe connected by piping and the syringe pump according to any one of claims 1 to 3,
A drive motor for driving the large-diameter piston and the small-diameter piston of the syringe pump;
Control means for controlling the suction of the liquid from the suction port and the discharge of the liquid from the discharge port by controlling the driving of the large-diameter piston or the small-diameter piston by the drive motor;
A dispensing device characterized by comprising: The dispensing device is
A large-diameter ball screw that is driven via a large-diameter clutch that transmits and shuts off the rotational force of the drive motor to the syringe pump, and moves the large-diameter piston along the piston axial direction;
A small-diameter ball screw that is driven via a small-diameter clutch and transmission means for transmitting and blocking the rotational force of the drive motor to the syringe pump, and moves the small-diameter piston along the piston axial direction;
With
The control means controls the movement of the large-diameter piston or the small-diameter piston by transmitting or blocking the rotational force of the drive motor to the large-diameter ball screw or the small-diameter ball screw by the large-diameter clutch or the small-diameter clutch. The dispensing apparatus according to claim 4, wherein: An automatic analyzer having a sample dispensing device for dispensing a sample and a reagent dispensing device for dispensing a reagent, and analyzing the components of the sample by reacting the sample with the reagent,
6. The automatic analyzer according to claim 4, wherein the sample dispensing device or the reagent dispensing device is configured using the dispensing device according to claim 4 or 5.

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