JP2013108906A - Liquid dispenser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a liquid dispenser that suppresses dripping without generating an air space for dripping prevention at a tip end of a dispensing nozzle, and can suppress generation of air bubble in a container and suppress dripping from the dispensing nozzle even while the dispensing nozzle is moving.SOLUTION: In a liquid dispenser, a division time elapse determination unit 401 activates a timer 404 and waits for the elapse of a division time (a time interval between intermittent operations) stored in a memory 405 (step 553), and determines whether or not to suspend a dripping prevention sequence according to an execution flag of dripping prevention processing which may be turned off during the waiting time for the elapse of the division time (step 556), and when the division time elapse determination unit 401 determines the elapse of the division time at the step 553, a dripping prevention operation control unit 402 drives a pump motor only by one pulse in order to apply negative pressure to a dispensing nozzle 100 (step 554).

Description

  The present invention relates to a liquid dispensing apparatus for dispensing a sample or reagent such as blood or urine collected for examination.

  As an example of a liquid dispensing apparatus, there is known a sample dispensing apparatus that dispenses blood or urine collected from a subject into another container for analysis and inspection by an automatic liquid separation apparatus or the like.

  This sample dispensing apparatus is an apparatus that is installed in a test room of a hospital or a laboratory and dispenses from a parent sample container to a child sample container for analysis by various analyzers. The parent sample container accommodates blood and urine collected from the subject for examination.

  In the current sample dispensing apparatus, liquid sag is prevented while the dispensing mechanism from the completion of sample aspiration to the start of sample discharge is operating. In other words, liquid dripping is prevented by applying a preset negative pressure in the dispensing nozzle after completion of sample suction from the parent sample container.

  As described in Patent Document 1, by applying the negative pressure, an air layer may be generated at the tip of the dispensing nozzle. Due to the presence of this air layer, bubbles may be formed in the child sample container in rare cases when the sample is discharged into the child sample container depending on the conditions of use of the apparatus and the state of the sample. This bubble disappears during transportation of the child sample container or adheres to the side surface of the child sample container due to surface tension.

  On the other hand, in the analyzer, when dispensing from the child sample container at the time of analysis, since the suction is performed from the center part of the child sample container, bubbles adhering to the side surface of the container do not matter.

  Moreover, there exists a countermeasure like the patent document 2 as a countermeasure against a bubble. This is a method of detecting a pressure signal in real time, determining whether or not to perform liquid dripping prevention suction processing, and performing suction processing when it is determined that liquid dripping prevention is necessary.

JP-A-5-273218 JP 2005-300236 A

  By the way, nowadays, in the automatic analyzer, in order to reduce the burden on the patient, the sample amount necessary for the analysis is reduced. When the sample amount of the child sample becomes small, there is a problem of evaporation of the sample in the child sample container until the analysis is performed. For this reason, in order to reduce the contact surface between the specimen and the air, it is conceivable that the child specimen container will be downsized.

  When the child sample container is downsized, the distance between the bubble adhering to the wall of the child sample container and the center of the child sample container is reduced, and in the analyzer, when the sample is aspirated from the child sample container by the dispensing nozzle, The possibility that the dispensing nozzle comes into contact with the bubbles is increased.

  If the dispensing nozzle comes into contact with bubbles when the sample is aspirated by the analyzer, the target amount of sample cannot be aspirated, and the analysis result may be abnormal.

  For this reason, in the sample dispensing device, measures against air bubbles will become essential in the future.

  When an air layer is generated at the tip of the dispensing nozzle to prevent liquid dripping as in the conventional technique described above, the presence of this air layer makes it possible to detect the child depending on the conditions of use of the analyzer and the state of the sample. There is a possibility that bubbles are formed in the child sample container when the sample is discharged into the container.

  Therefore, as in the technique described in Patent Document 2, if the pressure signal in the dispensing nozzle is processed to prevent liquid sag, without forming an air layer at the tip of the dispensing nozzle, It is conceivable to prevent dripping.

  However, for example, the dispensing nozzle needs to move to the installation position of the child sample container after aspirating the sample from the parent sample, and vibration due to the movement occurs, and this vibration causes a pressure change in the dispensing nozzle. For this reason, it is difficult to accurately determine whether or not the liquid in the dispensing nozzle needs to be prevented from dripping.

  Therefore, in the technique described in Patent Document 2, the liquid sag prevention function can be accurately operated only while the dispensing nozzle is stopped, and the liquid sag prevention function is difficult to operate accurately while the dispensing nozzle is moving. It is.

  An object of the present invention is to suppress liquid dripping without generating an air layer for preventing liquid dripping at the tip of the dispensing nozzle, to suppress the generation of bubbles in the container, and while the dispensing nozzle is moving Is to realize a liquid dispensing apparatus capable of suppressing liquid sag from the dispensing nozzle.

  In order to achieve the above object, the present invention is configured as follows.

  In the liquid dispensing apparatus, the dispensing nozzle for sucking and discharging the liquid, the pressure in the dispensing nozzle is changed, the liquid is sucked into the dispensing nozzle, and the sucked liquid is discharged from the dispensing nozzle. The liquid suction / discharge mechanism to be discharged, the dispensing nozzle moving mechanism for moving the dispensing nozzle from the liquid suction position to the liquid ejection position, and the operation of the liquid suction / discharge mechanism are controlled, and the liquid is discharged into the dispensing nozzle. And a controller that generates a negative pressure in the dispensing nozzle at regular time intervals after suction.

  Spilling can be suppressed without generating an air layer for preventing liquid sag at the tip of the dispensing nozzle, and the generation of bubbles in the container can be suppressed, and even when the dispensing nozzle is moving, the dispensing nozzle It is possible to realize a liquid dispensing device that can suppress liquid sag from the liquid.

1 is a schematic configuration diagram of an automatic analyzer to which the present invention is applied. It is explanatory drawing about the sample dispensing mechanism of the automatic analyzer shown in FIG. It is a figure which shows the example for moving a dispensing nozzle. It is explanatory drawing about the period until a liquid dripping generate | occur | produces from a dispensing nozzle. It is explanatory drawing of the mechanism of bubble generation. It is explanatory drawing about operation | movement of the sample dispensing apparatus in an automatic analyzer. It is a figure which shows the example of the dispensing head in a sample dispensing apparatus. It is a figure which shows the example of a display screen which inputs an initial setting value and liquid dripping measurement time, and displays an initial negative pressure amount and a pulse operation interval. It is an internal functional block diagram of a controller. It is a figure which shows the operation | movement flowchart of the dispensing control sequence for performing sample dispensing. It is a figure which shows the operation | movement flowchart of the liquid dripping prevention sequence for preventing liquid dripping.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic configuration diagram of an automatic analyzer to which the present invention is applied.

  In FIG. 1, an automatic analyzer 800 includes a sample rack transport mechanism 110 that transports a sample rack 104 in which a plurality of sample containers (parent sample containers) 115 are disposed, and a plurality of child sample containers or reaction containers 122. A child sample disk or reaction disk 102, a spectroscopic detector 140 for analyzing a sample contained in the reaction container 122, and a reagent disk 101 having a reagent container rack 111 in which the reagent container 112 is arranged are provided.

  Of the sample containers 115 arranged in the sample rack 104, the sample container 115 located at the dispensing position 120 is sucked by the detection dispensing nozzle of the sample dispensing mechanism (nozzle moving mechanism) 108 and discharged to the child sample container 122. Is done.

  The reagent accommodated in the reagent container 112 arranged in the reagent container rack 111 of the reagent disk 101 is sucked by the reagent dispensing mechanism 105 and discharged into the reaction container 122 arranged in the reaction disk 102. The dispensing mechanism 109 is a mechanism for discharging the reagent into the reaction container 122 as necessary.

  FIG. 2 is an explanatory diagram of the sample dispensing mechanism 101 of the automatic analyzer 800 shown in FIG. However, in FIG. 1, components not shown are also shown in FIG.

  In FIG. 2, the dispensing nozzle 100 of the sample dispensing mechanism 101 is connected to the suction / discharge pump 300, and the sample suction / discharge operation of the dispensing nozzle 100 is performed by the suction / discharge pump 300.

  The pressure in dispensing nozzle 100 is detected by pressure sensor 200, and the detected pressure value is supplied to controller 400. The controller 400 controls the operation of the suction / discharge pump 300 based on the pressure value supplied from the pressure sensor 200.

  The controller 400 controls the operation of the sample dispensing mechanism (nozzle movement mechanism) 108 and the operation of the display 600. In addition, the controller 400 controls the operation of the suction / discharge pump 300 in accordance with the command value input and displayed on the display 600.

  FIG. 3 is a diagram illustrating an example for moving the dispensing nozzle 100, and is a diagram illustrating an example different from the example illustrated in FIG. The present invention can also be applied to the example shown in FIG. The host CPU 1, the transport control CPU 2, and the dispensing control CPU 3 can be configured to be provided in the controller 400 shown in FIG.

  In FIG. 3, the host CPU 1 is a CPU that controls the overall operation of the automatic analyzer 800. The host CPU 1 sends a command from the conveyance path control CPU 2. Then, the transport path control CPU 2 controls the operation of the sample rack transport mechanism 110 that is the transport path.

  The dispensing control CPU 3 supplies a command signal to the dispensing mechanism driver 4. The dispensing mechanism driver 4 controls the operation of the XYZ moving mechanism 700 that moves the dispensing head 201 having the nozzle 100 in the XYZ triaxial directions, and sucks the sample 204 stored in the sample container 203 into the nozzle 100. .

  Moreover, the dispensing mechanism driver 4 discharges the sample accommodated in the nozzle 100 to a child sample container or the like. The dispensing head 201 and the XYZ moving mechanism 700 constitute the dispensing mechanism unit 5.

  Next, the operation of the sample dispensing device in the automatic analyzer 800 will be described with reference to FIG.

  In FIG. 6, the sample dispensing apparatus performs sample aspiration (negative pressure) during a sample aspiration operation period 270 from a parent test tube (parent sample container 115) containing blood or urine collected from a patient to the dispensing nozzle 100. 251 becomes large and the positive pressure 252 is almost 0). After completion of the specimen suction operation to the dispensing nozzle 100, negative pressure is added to the dispensing nozzle 100 in the negative pressure addition period 271 to prevent liquid dripping. Thereafter, the dispensing nozzle 100 is moved to the movement period 272 to the sample discharge position to the child sample container 122 for analyzing the sample.

  At this time, it may take time until the child sample container 122 can be prepared. Next, the sample aspirated from the parent sample into the child sample container 122 is discharged from the dispensing nozzle 100 during the discharge operation period 273 (the positive pressure 252 becomes large and the negative pressure 251 is almost zero).

  Next, a period from when the sample is sucked into the dispensing nozzle 100 until liquid sag occurs from the dispensing nozzle 100 will be described with reference to FIG.

  In FIG. 4, the state in which the dispensing nozzle 100 normally sucks the sample has a sufficient negative pressure as indicated by 110, and there is an air layer at the tip of the dispensing nozzle 100.

  Next, as time passes, the negative pressure 250 gradually decreases, and as shown by 120, the specimen in the dispensing nozzle 100 falls to the tip and the air layer disappears. When the time further elapses, as shown at 130, the specimen jumps out from the tip end portion of the dispensing nozzle 100 to be in a liquid bulb state and sag.

  Next, an example of a bubble generation mechanism will be described with reference to FIG.

  In FIG. 5, first, the sample is sucked into the dispensing nozzle 100 to be in the state 1010. Next, by making the inside of the dispensing nozzle 100 have a negative pressure, an air layer is generated at the tip end portion of the tip, and a state 1020 is obtained.

  Here, the specimen may adhere to the inner wall of the dispensing nozzle 100 where the air layer exists depending on the use conditions of the apparatus and the state of the specimen. When time elapses in this state, the specimen attached to the inner wall of the dispensing nozzle 100 moves to the distal end portion of the dispensing nozzle 100, and the distal end portion is closed with the specimen 1030.

  Next, when the discharge of the sample from the dispensing nozzle 100 to the child sample container is started, bubbles are generated like a soap bubble, and the state becomes 1040. Then, after the discharge to the child sample container is completed, the bubbles may not break and may remain in the state 1050 remaining in the liquid of the child sample container.

  Next, the operation of the embodiment of the present invention will be described. First, in order to automatically obtain the negative pressure amount, the controller 400 controls the suction / discharge pump 300 to cause the dispensing nozzle 100 to suck the sample. Thereafter, as shown in FIG. 4, the controller 400 applies a negative pressure of the initial setting value to the dispensing nozzle 100 and then sequentially monitors the pressure sensor value 250 in the dispensing nozzle 100 with the pressure sensor 200. The time 170 until the change area 260 that changes greatly is measured.

  This measured time 170 is set as a specimen holding time, and this specimen holding time 170 is compared with a liquid dripping prevention time 175 necessary for the specimen dispensing apparatus. Then, the required negative pressure amount is obtained.

  For example, when a dispensing head as shown in FIG. 7 is used, by operating the pulse motor 154, the bellows 155 expands and contracts to serve as a pump. The inside of the bellows 155 communicates with a dispensing tip (dispensing nozzle) 151 through an air passage 161.

  In this case, the unit of the negative pressure amount in the dispensing tip (dispensing nozzle) 151 can be replaced with a pulse of the minimum control unit for operating the pulse motor 154. Reference numeral 156 represents a pressure sensor, and reference numeral 158 represents a control unit.

  Assuming that the negative pressure amount of the initial setting value is 16 pulses for the control pulse to the pulse motor 154, and the liquid dripping prevention time required for the dispensing device is 70 seconds, the actual liquid dripping is measured. When the time of 280 seconds is 280 seconds, the negative pressure amount obtained automatically is the initial negative pressure amount / (measured time / drip prevention necessary for the dispensing device), that is, 16 / (280/70 ) And 4 pulses are obtained.

  Next, in the embodiment of the present invention, in order to generate the negative pressure for preventing the liquid dripping from the dispensing nozzle, the time interval for intermittently operating the pulse motor 154 is the liquid dripping prevention time / automatic. The number of pulses corresponding to the obtained negative pressure amount, that is, 70 seconds / 4 pulses, and here, the interval is 17.5 seconds. If the pulse motor 154 is driven one pulse at this time interval to apply a negative pressure, it is possible to prevent liquid dripping from the tip of the dispensing tip (dispensing nozzle) 154.

  FIG. 8 is a diagram showing an example of a display screen (display) 600 for inputting the initial set value and the liquid sag measurement time and displaying the initial negative pressure amount and the pulse operation interval. The display screen 600 may be input using a keyboard or a mouse, or the display screen 600 may be configured as a touch panel so that information can be input.

  FIG. 9 is an internal functional block diagram of the controller 400.

  In FIG. 9, the controller 400 includes a divided time elapsed determination unit 401, a timer 404, a divided time memory 405, a liquid dripping prevention operation control unit 402, and a nozzle movement control unit 403.

  Next, an example of a control sequence executed by the controller 400 will be described.

  FIG. 10 is a diagram showing an operation flowchart of a dispensing control sequence for dispensing a specimen, and FIG. 11 is a diagram showing an operation flowchart of a liquid dripping prevention sequence for preventing liquid dripping.

  In FIG. 10, the dispensing control sequence starts when the parent sample arrives at the apparatus (step 500), and first obtains a dispensing tip (step 501). Next, in order to suck from the parent sample, the nozzle movement control unit 403 sends a command signal to the nozzle moving mechanism 108 and moves the dispensing nozzle 100 to the suction position 120 of the parent sample container 115 (step 502).

  Then, in accordance with a command signal from the liquid dripping prevention control unit 402 to the pump motor 154, the suction operation from the parent sample to the dispensing nozzle 100 is performed (step 503). Thereafter, if execution of liquid sag prevention is designated by the setting unit 600, the liquid sag prevention operation control unit 402 turns on the execution flag of the liquid sag prevention process (step 504), and according to a command from the nozzle movement control unit 403 The nozzle moving mechanism 108 moves to the discharge position to the child sample container 122 (step 505).

  After that, when preparation for discharging into the child sample container 122 is completed, the liquid dripping prevention operation control unit 402 turns off the execution flag of the liquid dripping prevention process (step 506), operates the pump motor 154, and moves to the child sample container 122. The discharge process is performed (step 507). Finally, the used dispensing tip is discarded (step 508).

  On the other hand, in FIG. 11, the liquid dripping prevention sequence is always operating, and the liquid dripping prevention operation control unit 402 waits for the execution flag of the liquid dripping prevention processing to be turned on in accordance with a command from the setting unit 600 ( Step 551). When the execution flag of the liquid sag prevention process is turned on according to a command from the setting unit 600, the division time elapsed determination unit 401 activates the timer 404 and the division time (intermittent operation) stored in the division time memory 405. Wait for the time interval (17.5 seconds) to elapse (step 553).

  While waiting for the elapse of the division time, the execution flag of the liquid dripping prevention process may be turned off by an instruction from the setting 600, so a determination is made as to whether or not to interrupt the liquid dripping prevention sequence ( Step 556).

  When the execution flag of the liquid dripping prevention process is turned off, the process proceeds from step 556 to step 555, the operation of the timer 404 is stopped, and the process returns to step 551.

  In step 553, when the divided time elapsed determination unit 401 determines that the divided time has elapsed, that is, when the time interval for intermittently operating the value of the timer 404 has elapsed, negative pressure is applied to the dispensing nozzle 100. Therefore, the liquid dripping prevention operation control unit 402 drives the pump motor 154 by one pulse (step 554). In step 555, the timer 404 is reset and the process returns to step 551, which is the first process.

  By performing the above operation, the liquid from the dispensing nozzle 100 does not generate an air layer at the tip of the dispensing nozzle and does not need to detect the internal pressure during the movement operation of the dispensing nozzle 100. Bubble generation in the child sample container can be suppressed while preventing sagging.

  In addition, although the example mentioned above is an example at the time of applying this invention to the automatic analyzer which dispenses a specimen, it is applicable also to the dispensing of a reagent. When applied to reagent dispensing, the present invention is applied to dispensing from a reagent container to a reaction container by a reagent dispensing nozzle. The reagent dispensing nozzle having the same configuration as that shown in FIG. 7 can be used.

  The present invention is also applicable to a sample pretreatment apparatus. The configuration of this preprocessing device is the same as that shown in FIG. 1, except that the spectroscopic detector 140 is omitted in the case of the preprocessing device.

  In addition, settings such as initial set values (liquid sag prevention time, initial set negative pressure amount), liquid sag measurement time, etc. are performed after the automatic analyzer is manufactured and installed in the place of use, but when the installation environment changes, It may be reset.

  In the above-described embodiment, the negative motor is generated by driving the pulse motor 154 by one pulse at an interval of 17.5 seconds shorter than the liquid dripping prevention period. It can also be configured to generate negative pressure by driving the pulse motor 154 for two pulses at intervals of 35 seconds, which is a half period. Alternatively, the negative pressure can be generated by driving the pulse motor 154 for three pulses at an interval of 52.5 seconds, which is two-thirds of the liquid dripping prevention period.

  DESCRIPTION OF SYMBOLS 1 ... Host CPU, 2 ... Conveyance path control CPU, 3 ... Dispensing control CPU, 4 ... Mechanism driver, 5 ... XYZ moving mechanism, 100 ... Dispensing nozzle, 101. ..Reagent disk, 102 ... Reaction disk, 104 ... Sample rack, 105 ... Reagent dispensing mechanism, 108 ... Sample dispensing mechanism (nozzle movement mechanism), 109 ... Dispensing mechanism, DESCRIPTION OF SYMBOLS 110 ... Sample rack conveyance mechanism, 111 ... Reagent container rack, 112 ... Reagent container, 115 ... Sample container, 122 ... Reaction container, 140 ... Spectral detector, 151 ... Dispensing tip, 154 ... pulse motor (pump motor), 155 ... bellows, 156 ... pressure sensor, 158 ... control unit, 161 ... air passage, 200 ... pressure sensor 300 ... Suction / discharge pump, 400 ... Controller, 401 ... Divided time elapsed determination unit, 402 ... Liquid dripping prevention operation control unit, 403 ... Nozzle movement control unit, 404 ... Timer, 405, divided time memory, 600, display, 700, XYZ moving mechanism, 800, automatic analyzer

Claims (6)

A dispensing nozzle for aspirating and discharging liquid;
A liquid suction / discharge mechanism that changes the pressure in the dispensing nozzle, sucks the liquid into the dispensing nozzle, and discharges the sucked liquid from the dispensing nozzle;
A dispensing nozzle moving mechanism for moving the dispensing nozzle from a liquid suction position to a liquid ejection position;
A controller that controls the operation of the liquid suction / discharge mechanism and sucks the liquid into the dispensing nozzle, and then generates a negative pressure within the dispensing nozzle at regular time intervals;
A liquid dispensing apparatus comprising: The liquid dispensing apparatus according to claim 1,
The liquid dispensing apparatus according to claim 1, wherein the predetermined time interval is a time shorter than a time when liquid sag occurs from the tip of the dispensing nozzle after the liquid is sucked into the dispensing nozzle. The liquid dispensing apparatus according to claim 1,
The liquid suction / discharge mechanism has a pulse motor that changes the pressure in the dispensing nozzle, and the controller supplies a pulse signal to the pulse motor at a certain interval to apply a negative pressure in the dispensing nozzle. A liquid dispensing apparatus characterized by being generated. The liquid dispensing apparatus according to claim 3,
The controller has a liquid dripping prevention period in which liquid dripping is not generated from the tip of the dispensing nozzle, and the initial number of pulses supplied from the controller to the pulse motor when the dispensing nozzle sucks liquid is the liquid dripping prevention The number of pulses for generating a negative pressure that does not cause dripping from the tip of the dispensing nozzle within the period, the number of pulses supplied to the pulse motor at the predetermined time interval is less than the initial pulse number, The liquid dispensing apparatus is characterized in that the predetermined time interval is shorter than the liquid dripping prevention period. In a sample pretreatment device that has a sample dispensing mechanism that dispenses a parent sample stored in a parent sample container into a child sample container, and supplies the sample stored in the child sample container to the analyzer,
The sample dispensing mechanism is
A sample dispensing nozzle for aspirating and discharging a liquid sample;
A sample suction / discharge mechanism for changing the pressure in the sample dispensing nozzle, causing the sample to be sucked into the sample dispensing nozzle, and discharging the sucked sample from the dispensing nozzle;
A sample dispensing nozzle moving mechanism for moving the sample dispensing nozzle from the sample suction position to the sample discharge position;
A controller that controls the operation of the sample aspirating and discharging mechanism, and aspirates a sample in the sample dispensing nozzle, and then generates a negative pressure in the sample dispensing nozzle at regular time intervals;
A specimen pretreatment apparatus comprising: A reagent disk in which a reagent container for containing a reagent is arranged, a reaction disk in which a reaction container is arranged, and a sample from the sample container for containing the sample are aspirated, and the sample is placed in the reaction container arranged in the reaction disk. A sample dispensing mechanism for discharging, a reagent dispensing mechanism for aspirating the reagent from a reagent container containing the reagent, and discharging the reagent into the reaction container disposed on the reaction disk, and the reaction disk disposed on the reaction disk In an automatic analyzer having a spectroscopic detector for detecting a specimen in a reaction vessel,
The sample dispensing mechanism is
A sample dispensing nozzle for aspirating and discharging a liquid sample;
A sample suction / discharge mechanism for changing the pressure in the sample dispensing nozzle, causing the sample to be sucked into the sample dispensing nozzle, and discharging the sucked sample from the dispensing nozzle;
A sample dispensing nozzle moving mechanism for moving the sample dispensing nozzle from the sample suction position to the sample discharge position;
A controller that controls the operation of the sample aspirating and discharging mechanism, and aspirates a sample in the sample dispensing nozzle, and then generates a negative pressure in the sample dispensing nozzle at regular time intervals;
An automatic analyzer characterized by comprising.

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