JPH0560768A - Method and apparatus for sampling specimen in automatic analyzer - Google Patents

Abstract

PURPOSE:To make it possible to detect the liquid surface of a specimen accurately and simply by jetting gas through sample pipet, and detecting the time when the tip of the pipet comes into contact with the liquid surface of the specimen based on the change in pressure. CONSTITUTION:A first pipet-descent controlling means 6 discharges the gas from the inside of a sample pipet 3 and lowers the pipet 3 from an upper stop-point position. When the rise of the gas pressure in the pipe 3 is detected with a pressure-change detecting means 5, it is judged that the tip of the pipet 3 reaches the liquid surface of a specimen (k) in a specimen cup 1. The discharge of the gas is stopped with a gas feeding stopping means 7. Then, a second pipet-descent controlling means 8 lowers the pipet 3 by the minute specified amount and slightly dips the tip nozzle into the specimen (k). After the specimen (k) is sucked, the pipet 3 is returned to the upper stop-point position. Thus, the liquid surface of the specimen can be detected accurately and simply under the state wherein there is no dispersion of detecting sensitivity without making the apparatus itself complicated and large.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sample sampling method for an automatic analyzer for performing physicochemical analysis, biochemical analysis, immunological analysis, etc. The present invention relates to a method for sampling a sample of an automatic analyzer suitable for immunological analysis such as trace component analysis in clinical tests, which has a great influence, and improvement of the apparatus.

[0002]

2. Description of the Related Art In recent years, RIA method, EIA method and latex agglutination reaction method have been known as a trace component analysis in clinical tests, and as an automatic analyzer utilizing these, vertical and horizontal directions are used. A predetermined amount of liquid sample in the sample cup is sucked with a movable sample suction pipette for sample dispensing, and after dispensing the sample into the reaction cell, a predetermined reagent is dispensed into the reaction cell and An optical analysis of the reaction with a reagent is already provided.

By the way, in this kind of automatic analyzer, if the sampling amount (dispensing amount) of the sample in the reaction cell varies with respect to the specified amount, the test analysis result is greatly affected, and the reliability of the test analysis is improved. In the past, for example, when a sample pipette sucks the sample in the sample cup, it is detected that the tip nozzle of the sample cup has reached the sample liquid level, and The tip nozzle is lowered by a small amount to prevent the outer wall of the nozzle from unnecessarily immersing in the sample, so that the sample adhered to the outer wall of the nozzle enters the reaction cell when dispensing the sample into the reaction cell. A method of suppressing the variation of the sampling amount of the sample in the reaction cell to the minimum necessary (for example, RSP5000 manufactured by Lab Science Co., Ltd.). .

[0004]

However, as the conventional liquid level detection method, a method based on the electric conductivity measurement method using electrodes, a method based on the capacitance measurement method, a method based on the optical measurement method, or Various types have been developed, such as those based on ultrasonic measurement methods. For example, in the method based on electrical conductivity measurement methods using electrodes, not only is there a risk of false detection due to electrical noise, It is indispensable that it cannot be applied to a non-conductive sample, and in the case of a method based on a capacitance measurement method, not only is there a risk of false detection due to electrical noise, For example, when adopting the method in which the tip nozzle tip of the sample pipette is detachably exchanged for each sample, the liquid level detection accuracy decreases as the manufacturing error of the nozzle tip directly affects the detected capacitance. Easiness , The substantial amount of the sample pipette nozzle immersed in the sample varies, and when the sample is dispensed into the reaction cell, the sample amount variation attached to the outer wall of the nozzle directly affects the sample sampling amount variation. In addition, if it is based on an optical measurement method,
The detection sensitivity changes subtly due to the difference in the components and color of the sample, and the liquid level detection accuracy is likely to decrease correspondingly, and the sampling amount error becomes large as described above. Based on this, a technical problem has been found that the device configuration is large in the first place and it is difficult to apply it to the liquid level detection of the specimen in the sample cup having a small diameter.

Further, when a sample pipette is used to dispense a sample into a reaction cell, the sample is usually discharged by a pump. However, when the sample is sampled in a very small amount, the tip of the sample pipette is caused by the surface tension of the sample. The residual liquid of the sample is likely to remain on the inner wall of the nozzle, and in addition, the variation in the residual liquid amount of the sample attached to the outer wall of the tip nozzle greatly affects the sampling amount of the sample. It was also found that there is a fundamental technical problem that it is easy to become.

The present invention has been made in order to solve the above technical problems, and the liquid level of the sample in the sample cup can be easily and accurately detected, and the tip nozzle of the sample pipette is immersed in the sample. The amount can be easily kept constant (first technical problem), and the sample residual liquid on the inner and outer walls of the tip nozzle of the sample pipette can be suppressed to a minute amount when sampling a small amount (second technical problem). ), And finally, to provide a sample sampling method for an automatic analyzer and a device therefor, which maintains good sample sampling accuracy.

[0007]

[Means for Solving the Problems] That is, a first method invention for solving the first technical problem is to use a sample pipette for sample suction / dispensing, which is movable vertically and horizontally, in a sample cup. While sucking a predetermined amount of the liquid sample of
After dispensing the sample into the reaction cell, the sample in the sample cup is sampled with a sample pipette, assuming an automatic analyzer that dispenses a predetermined reagent into the reaction cell and optically analyzes the reaction between the sample and the reagent. When aspirating the sample pipette, the pipette first lowering step of lowering the sample pipette from the top stop position while ejecting gas from the sample pipette with a minute pressure, and the sample pipette when the gas pressure in the sample pipette rises to a predetermined level It is judged that the tip of the sample has reached the liquid level of the sample, and the liquid level detection process that stops the gas discharge operation, and at the time when the liquid level of the sample is detected in this liquid level detection process The second pipette lowering step of lowering the tip nozzle to slightly immerse the tip nozzle in the sample, and the sample suctioning operation for performing the sample suction operation when the second pipette lowering step is completed. A step, a sample sampling method characterized by the sample suctioning execution process and a pipette return step for returning the sample pipette onto stop point position upon completion.

The apparatus invention embodying the first method invention is, as shown in FIG. 1, an automatic analyzer for optically analyzing the reaction between a liquid sample k dispensed in a reaction cell 11 and a reagent. Based on the premise that the sample pipette 3 for sample suction and dispensing is movable in the vertical and horizontal directions, the sample suction operation in the sample cup 1 is performed by the sample suction stage, and the sample dispensing stage Sample aspirating / dispensing means 2 for performing a sample dispensing operation on the reaction cell, and gas supply means 4 for supplying a gas of minute pressure into the sample pipette 3.
A pressure change detecting means 5 for detecting that the gas pressure in the sample pipette 3 has risen to a predetermined level, and the gas supply means 4 are operated to discharge the gas from the sample pipette 3 with a minute pressure. Pipette first lowering control means 6 for lowering 3 from the upper stop position, and the gas supply means 4 at the time when the pressure change detecting means 5 detects that the gas pressure in the sample pipette 3 has risen to a predetermined level. Gas supply stopping means 7 for stopping the operation of
When the gas supply stopping means 7 is activated, the pipette second lowering control means 8 for lowering the sample pipette 3 by a minute specified amount to slightly immerse the tip nozzle in the sample, and the pipette second lowering control means 8 are used. Pipette suction control means 9 for executing the sample suction operation when the descending operation of the sample pipette 3 is completed, and returning the sample pipette 3 to the upper stop position when the sample suction operation by the pipette suction control means 9 is completed. A sample sampling device comprising a pipette return control means 10.

A method invention for solving the second technical problem is to aspirate a predetermined amount of a liquid sample in a sample cup with a sample pipette for sample suction / dispensing that is movable vertically and horizontally. In addition, after dispensing the sample into the reaction cell, in an automatic analyzer that optically analyzes the reaction between the sample and the reagent by dispensing a predetermined reagent into the reaction cell, in the reaction cell with a sample pipette. When dispensing the sample, the pipette lowering step of lowering the sample pipette from the upper stop point to the position close to the sample sampling amount liquid level in the reaction cell, and the sample dispensing at the end of this pipette lowering step At least when the sample pipette is located near the liquid level of the sample sampling volume, at the end of this sample dispensing execution step While discharging the gas from sample pipette, a specimen sampling method is characterized in that a pipette return step for returning the sample pipette onto stop point position.

The apparatus invention embodying the second method invention is, as shown in FIG. 1, an automatic analyzer for optically analyzing the reaction between a liquid specimen dispensed in a reaction cell 11 and a reagent. On the premise that the sample pipette 3 for sample suction and dispensing is movable in the vertical and horizontal directions, the sample suction operation is performed on the sample suction stage, and the reaction cell 11 is operated on the sample dispensing stage. The sample suction / dispensing means 2 for executing the sample dispensing operation, the gas supply means 12 for supplying a gas of a predetermined pressure into the sample pipette 3, and the sample sampling amount in the reaction cell 11 are close to the liquid level. Pipette lowering control means 13 for lowering the sample pipette 2 from the upper stop position to the position, and sample dispensing when the lowering operation of the sample pipette 3 by the pipette lowering control means 13 is completed. Pipette dispensing control means 14 for executing the above, a gas supply controlling means 15 for operating the gas supplying means 12 for a predetermined time when the sample dispensing operation by the pipette dispensing control means 14 is finished, and a pipette dispensing control means 14 And a pipette return control means 16 for returning the sample pipette 3 to the upper stop point when the sample dispensing operation by the above is completed.

In such technical means, the horizontal path of movement of the sample pipette 3 by the sample aspirating / dispensing means 2 may be appropriately selected, but from the viewpoint of simplifying the drive system, rotation is possible. It is preferable to design the sample pipette 3 to be rotationally moved by the arm. Further, the sample pipette 3 may have an integrated tip nozzle, but a viewpoint of avoiding carryover (a phenomenon in which the reliability of the inspection item is deteriorated due to the influence of another person's sample remaining in the nozzle). Therefore, it is necessary to design the tip nozzle of the sample pipette 3 so as to wash each sample test, and from the viewpoint of surely avoiding carryover, it is possible to dispose of the sample k corresponding to each sample k. It is preferable to prepare a nozzle tip and attach the nozzle tip to the tip of the sample pipette 3 detachably for each sample test.

The gas supplied from the gas supply means 4 is not limited to air, and may be N ₂ , He, Ar or the like as long as it does not react with the sample k. Further, it is necessary to set the gas supply pressure (discharge pressure) so that when the tip nozzle of the sample pipette 3 approaches the liquid surface of the sample k, bubbling does not occur on the liquid surface of the sample k.
Although it varies depending on the type of the sample k, a sample having about _{2 to 3} H ₂ O is usually selected.

Further, the detection level of the pressure change detecting means 5 may be set based on the theoretical pressure rise at the stage when the tip nozzle of the sample pipette 3 comes into contact with the liquid surface of the sample k, but it is actually set. It is preferable to set in consideration of the pressure increase.

Furthermore, as the pipette first lowering control means 6, the sample pipette 3 may be temporarily stopped when the gas supply stopping means 7 operates, or immediately without stopping the sample pipette 3. The pipette second lowering control means 8 may be shifted to the lowering operation.

Further, as the descending dimension of the sample pipette 3 by the pipette second descending control means 8, the minimum necessary size is selected within a range that does not impair the sample suction operation, and each test is performed in consideration of the sampling amount of the sample k. It is set individually for each item.

Also, the gas used in the gas supply means 12 is not limited to air as in the gas supply means 4, but may be N ₂ , He, Ar as long as it does not react with the sample k.
Etc. may be selected as appropriate. Further, the gas pressure of the gas supply means 12 needs to be set to such an extent that the sample remaining on the inner wall of the sample pipette 3 can be blown out, and although it varies depending on the type of the sample k, it is usually used for liquid level detection. A micro pressure higher than the gas supply pressure is used. Furthermore, when trying to realize the first invention and the second invention at the same time,
Considering the simplification of the apparatus, it is preferable to share the gas supply means 4.12. In this case, however, it is necessary to design the pressure adjustment means so that the gas pressure required for each can be obtained. is necessary.

The lowering point of the lowering operation of the sample pipette 3 by the pipette lowering control means 13 may be slightly above the sample sampling amount liquid level,
Specifically, it is necessary to set the distance between the tip nozzle of the sample pipette 3 and the sample k in the reaction cell 11 to a stringing state due to the surface tension when the sample dispensing operation is completed. ..

The gas supply timing of the gas supply control means 15 is such that the sample pipette 3 and the sample k are at least immediately after the start of the return operation of the sample pipette 3.
It only needs to be set while the stringing state between and disappears, and it is not necessary to set it unnecessarily long.

When the inside of the sample pipette 3 is clogged,
Since it becomes impossible to perform the sampling operation of the sample, from the viewpoint of ensuring the safety of the device,
It is necessary to provide means for detecting clogging of the sample pipette 3, and from the viewpoint of simplification of the device,
An abnormal pressure detection means 17 for detecting that the gas pressure in the sample pipette 3 has risen to an abnormal level during the gas supply operation by the gas supply control means 15 is added, and when the abnormal pressure detection means 17 detects the abnormal pressure. It is preferably designed to detect clogging of the sample pipette 3.

[Action]

In the technical means as described above, according to the first invention, the step of sucking the sample k is performed as shown in FIG. First, the hippet first descent control means 6
Causes the sample pipette 3 to descend from the top stop position while ejecting gas from the sample pipette 3 with a very small pressure (FIG. 2a), and the pressure change detection means 5 detects an increase in gas pressure in the sample pipette ( When the tip of the sample pipette 3 reaches the liquid surface of the sample k), the gas supply stopping means 7 stops the gas discharging operation (FIG. 2).
b). Then, the pipette second lowering control means 8 lowers the sample pipette 3 by a very small predetermined amount to immerse the tip nozzle in the sample k by only δ (FIG. 2c), and the pipette suction control means 9 performs the suction operation of the sample k. This is executed (FIG. 2d), and then the pipette control means 10 returns the sample pipette 3 to the upper stop position (FIG. 2e).

Further, according to the second apparatus invention, the step of dispensing the sample k is performed as shown in FIG. First, the pipette lowering control means 13 causes the sample pipette 3 to reach a position close to the sample sampling amount liquid level in the reaction cell 11.
Is lowered from the upper stop point position (FIG. 3a), and the pipette dispensing control means 14 executes the dispensing operation of the sample k (3b). Then, when the dispensing operation of the sample k is completed, the gas supply control means 15 discharges gas from the inside of the sample pipette 3 while the sample pipette 3 is positioned near the liquid level of the sample sampling amount, and the pipette return control means 16 is The sample pipette 3 is returned to the upper stop position (Fig. 3c). At this time, as shown in the enlarged portion of FIG. 3, when the dispensing operation of the sample k is completed, the surface tension of the sample k causes a stringing state between the tip nozzle of the sample pipette 3 and the sample k. In this state, when gas is supplied into the sample pipette 3, the sample k attached to the inner wall of the sample pipette 3
The residual liquid k1 of
Further, when the tip nozzle of the sample pipette 3 starts to rise, the residual liquid k2 of the specimen adhering to the outer wall of the tip nozzle of the sample pipette 3 is uniformly sucked by the tension of the specimen portion k0 in the stringed state, It is recovered to the reaction cell 11 side.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on the embodiments shown in the accompanying drawings. 4 to 6 are explanatory views showing the entire system of one embodiment of the automatic analyzer to which the present invention is applied. 1. Outline of automatic analyzer The automatic analyzer according to this embodiment is configured for immunochemical analysis using the latex agglutination reaction method, and a sample sampling device for sampling a plurality of samples (serum in this example), respectively. 100, a sample reaction measuring device 200 that dispenses a predetermined reagent (latex reagent in this embodiment) to the sampled sample, reacts the sample with the reagent, and optically measures the reaction result. The control system 300 is provided which controls the sampling device 100 and the sample reaction measuring device 200 according to a predetermined sequence and outputs the reaction result of the sample and the reagent.

Outline of Specimen Sampling Device 100 In FIGS. 4 to 6, reference numeral 101 is a disc-shaped sample table that holds a required number of sample cups (specimen cups) 102 and dilution cups 103 in a concentric loop. The sample suction stage is configured to intermittently transfer the sample cup 102 in which the sample to be inspected is stored and the dilution cup 103 in which the dilution liquid of the sample can be stored. Further, in the outermost peripheral portion of the sample table 101, the number of the disposable nozzle tips 104 corresponding to the number of the sample cups 102 [in this embodiment, the hole diameter is 0.5 ±
0.05 (mm)] is detachably held in a loop.

Reference numeral 105 is a serum pipetting mechanism for sampling serum as a sample (sample aspirating operation and sample dispensing operation), and has a sample pipette 106 that can move up and down and rotate. The nozzle tip 104 is detachably attached to the tip of the pipette 106 for each sample inspection, and a required amount of the sample in the sample cup 102 is sucked, or if necessary, the dilution cup 1
The sample and the diluting solution are dispensed into the sample 03, or the sample sampled in the cuvette 202 described later is dispensed. In addition, reference numeral 107 is a metering pump (sampling pump) for serum, 108 is a diluent tank, 10
Reference numeral 9 is a metering pump for dilution. In this embodiment, since the nozzle tip 104 for the same sample does not have a risk of so-called carryover, it is cleaned in the cleaning tank 110 and reused. It is artificially discarded when the inspection is completed.

Outline of Sample Reaction Measuring Apparatus 200 In FIGS. 4 to 6, reference numeral 201 is a reaction in which a required number (60 in this embodiment) of cuvettes (reaction cells) 202 are held in a loop at predetermined pitch intervals. Is a table,
The cuvette 202 is intermittently transferred in a certain direction as a result of stepwise driving. Also, reference numeral 2
03 is a reagent bottle containing a latex reagent,
It is provided coaxially with the reaction table 201, but is rotationally driven differently from the reaction table 201.
Reference numerals 204 and 205 denote first reagent pipetting mechanism and second reagent pipetting mechanism, and 206 and 20.
7 is a reagent washing tank for washing each reagent pipetting mechanism,
208 and 209 are a first reagent metering pump and a second reagent metering pump.

Reference numeral 211 denotes a cuvette supply / disposal device that supplies a new cuvette 202 into the reaction table 201 and discards the cuvette 202 that has been inspected, and sequentially guides and conveys a plurality of rows of cuvettes 202 to the front row side. Cuvette rack holder 212 and cuvette discard tray 213 for discarding the inspected cuvette 202
The cuvette rack holder 212 is provided at the frontmost row, and holds one cuvette 202 to set the cuvette 202 at a predetermined portion of the reaction table 201, and holds the inspected cuvette 202 to the cuvette discard tray 213 side. It is configured with a cuvette feeder 214 for conveying.

Further, reference numeral 215 is an optical measuring device for optically measuring the reaction between the sample and the reagent at a predetermined inspection stage, using a semiconductor laser diode as a light source,
The amount of change in the forward scattering intensity that changes with the progress of the antigen / antibody reaction in the cuvette 202 in the optical path is captured and measured by an integrating sphere, and at the same time the intensity of transmitted light is also measured. Compensation measures are taken for interference factors other than, and the turbidity value is obtained by this.

Control System A so-called microcomputer system is adopted as the control system 300 in this embodiment, and CP
The U 301 executes a predetermined inspection program and operates the sample sampling device 100 and the sample reaction measuring device 200 via the control system circuit 302. still,
Reference numeral 303 is a liquid crystal display for displaying inspection results,
304 is an operation panel for instructing an inspection menu and the like, 305
Is a printer for outputting inspection results and the like, and 306 is a floppy disk drive used for storing data such as inspection results on a floppy disk.

2. Configuration of Each Part of Sample Sampling Device ◎ Sample Table In FIGS. 7 and 8, a sample table 101 is a drive motor (stepping motor in this embodiment) 111.
Is supported on a rotary drive shaft 112 connected to the sample table 101.
And locking holes 113 and 114 for locking the dilution cup 103
And a locking groove 115 for locking the nozzle tip 104 is provided, and in this embodiment, the sample cup 102, the dilution cup 103, and the nozzle tip 104 that contain the specimen to be tested will be described later. The sample pipettes 106 are arranged along the horizontal rotation locus (indicated by A in FIG. 8). In FIG. 7, reference numeral 1
Reference numeral 16 is a position detector for compensating the intermittent transfer operation of the sample table 101. The position detector 16 is provided coaxially with the rotary drive shaft 112, and a rotary disk around which slits are formed at every arrangement angle pitch of the sample cups 102. 117
And an optical sensor 118 for detecting the slit position of the rotary disk 117. Also, reference numeral 11
Reference numeral 9 is a table cover that covers the upper side of the sample table 101 and has a notch 120 at a position corresponding to the sample suction stage.

Serum Pipetting Mechanism In FIGS. 9 to 11, serum pipetting mechanism 105
Has a movable arm 121 which is rotatable and vertically movable, and the sample pipette 106 is attached to the tip of this movable arm 121. In this embodiment, the support structure of the movable arm 121 is provided with an elevating table 125 on a shaft of a drive motor 123 fixed to a supporting bracket 122 via a link mechanism 124 and is supported on the elevating table 125 via a bearing 126. The rod 127 is rotatably supported, and the base of the movable arm 121 is fixed to the tip of the support rod 127. A guide pulley 129 that rotates integrally with the support rod 127 is attached to a part of the support rod 127 via a linear sliding bearing 128, and the guide pulley 129 has a drive motor fixed to the support bracket 122. 130
The driving force from is transmitted via the belt 131. Incidentally, reference numeral 132 is a stopper mechanism 133 for restricting the upper limit position and the lower limit position of the support rod 127.
Is a position detector for detecting the rotation stop angular position of the support rod 127.

FIG. 12 shows the specific structure of the sample pipette 106. In the figure, reference numeral 140 is a slide shaft that slides only in the vertical direction along the parallel pin 141 and the slide guide 142.
The solenoid valve holder 143 is attached to the lower end of 40, and the solenoid valve 144 is held by the solenoid valve holder 143.
A chip holder 14 having a pipe 147 for forming a flow path through a joint 145 on the solenoid valve holder 143.
6 is attached, and the flow path is appropriately selected according to the flow path switching operation by the solenoid valve 144.
Reference numeral 148 denotes the nozzle holder 104 and the tip holder 1
Buffer spring for inserting 46 with constant pressure, 1
Reference numeral 49 is a cover for covering the solenoid valve 144 and other members.

A guide cylinder 135 is provided upright on the support bracket 122 located around the support rod 127, and the sample pipette 1 is mounted on the guide cylinder 135.
A tip detaching lever 150 for detaching the nozzle tip 104 from 06 is rotatably engaged. As shown in FIGS. 11 and 13, in particular, the tip release lever 150 includes a tip attachment / detachment stage C (corresponding to a locking groove 115 position adjacent to the sample suction stage S corresponding to the position of the sample cup 102) and a sample dispensing stage. The tip detaching lever 1 is installed at an initial position on the tip attaching / detaching stage C side of a cleaning stage W to be described later, which is located in the middle of RT, and the tip detaching lever 1 is placed in standby at this initial position.
A stopper 151 with which 50 abuts is provided, and the tip release lever 150 is normally urged by the urging spring 152 toward the stopper 151 side. Further, a locking groove 153 is formed in a side portion near the tip end side of the tip release lever 150 near the sample dispensing stage RT,
Only when the sample pipette 106 is set at an intermediate stop point below the upper stop point, the tip release lever 150 is attached to the joint between the sample pipette 106 and the nozzle tip 104.
The engaging groove 153 is engaged.

Nozzle Tip Cleaning System In this embodiment, a cleaning tank 110 is installed on the cleaning stage W located between the tip mounting / demounting stage C and the sample dispensing stage RT. As shown in FIGS. 5, 6 and 13, the cleaning tank 110 is a cylindrical tank main body 1 in particular.
At the bottom of 61 is a drainage duct 1 leading to a drainage tank 163.
62 are connected to each other, and a U-shaped cut 164 is formed on the peripheral wall of the tank body 161 on the chip attachment / detachment stage C side. Then, injection nozzles 166, which are connected to the cleaning tank pump 165, are provided at approximately two locations on the inner wall of the tank body 161, and the nozzle tip 1 inserted in the tank body 161 is provided.
While the cleaning water is sprayed on the outer wall of the nozzle 04, an air discharge nozzle (not shown) is provided on the inner wall of the tank body 161, and when the outer wall cleaning of the nozzle tip 104 by the cleaning water is completed, the nozzle Air is blown onto the outer wall of the chip 104. A washing pump 168 is connected to the flow path from the sampling pump 107 to the sample pipette 106 via a switching valve 167.
When the eight side is selected, the cleaning water from the cleaning pump 168 flows into the nozzle tip 104. 5 and 6, reference numeral 169 is a water supply tank,
An opening / closing valve 170 is provided between the water supply tank 169 and the cleaning pump 168. Also, in this example,
The washing tank pump 165 is also connected to the reagent washing tanks 206 and 207, and the washing pump 168 is also connected to the reagent pumps 208 and 209 through the switching valves 171 and 172, respectively.

Sampling Aid System by Air The sampling aid system by air used in this embodiment is shown in FIGS. 6 and 14. In FIG. 14, the same components as those already described are designated by the same reference numerals, and detailed description thereof will be omitted here. In the figure,
Reference numeral 181 is an air pump, and 182 is, for example, 0.2 kgf.
Air pressure adjustment valve that is adjusted to an air pressure of about / cm2,
183 is an air sensing unit, for example, FIG.
An air micrometer (component: a pneumatic amplifier 184, whose diaphragm operates a predetermined amount when the pressure in the flow channel rises, a pneumatic amplifier 1
When the diaphragm 84 operates, the corresponding diaphragm operates to turn on the micro switch, and the air-electric converter 185, and the flow rate variable throttle 186 for variably setting the operation setting pressure).

Reference numeral 187 denotes a solenoid valve that closes the air flow path from the air pump 181 when the air sensing unit 183 detects a predetermined pressure increase, and 188 indicates when the air sensing unit 183 detects a predetermined pressure increase. A clogging detector that detects that the nozzle tip 104 is clogged, 189 is an electromagnetic valve that normally opens the air flow path side and switches between the sampling pump 107 and the air flow path, and 190 is always open the air flow path side. It is an electromagnetic valve that switches between the dilution pump 109 and the air flow path.
Incidentally, reference numeral 191 designates the diluent tank 108 and the dilution pump 10.
9 is a solenoid valve for opening and closing the flow path between the solenoid valve and the valve 9.

3. Operation of Sample Sampling Device The operation of the sample sampling device is performed by the CPU executing a predetermined inspection program as follows.

◎ Nozzle tip mounting operation processing (see FIG. 16)
a) The serum pipetting mechanism 105 moves from the initial position (top stop point of the washing tank stage W) to above the corresponding nozzle tip 104 of the tip attaching / detaching stage C. At this time, since the sample pipette 106 of the serum pipetting mechanism 105 moves at the upper stop point, the tip release lever 150 located at the intermediate point between the washing tank position and the tip attachment / detachment stage C is the sample pipette of the serum pipetting mechanism 105. 10
It does not interfere with 6. Then, when the sample pipette 106 of the serum pipetting mechanism 105 is lowered and the tip of the sample pipette 106 collides with the nozzle tip 104, the nozzle tip 104 is fixed to the sample table 10.
The nozzle tip 104 is attached to the tip of the sample pipette 106 because it is supported on the sample pipette 106.

◎ Sample Suction Operation Process (FIG. 16b) The serum pipetting mechanism 105 having the nozzle tip 104 mounted thereon moves to the sample cup 102 (sample suction stage S). Here, the serum pipetting mechanism 10
5 descends toward the sample cup 102. At this time, air from the air pump (2.0 mm in this embodiment) is used.
(H ₂ O pressure air) is blown from the tip of the nozzle tip 104 through the line. And the nozzle tip 104
When the tip of the air comes into contact with the sample, the air sensing unit 1
83 detects a change in pressure, the valve is switched, the flow path is connected to the side of the sampling pump 107, and the serum pipetting mechanism 105 is lowered as much as necessary for suction. After that, the serum quantitative pump 107 once sucks a predetermined amount of the sample, and when the serum pipetting mechanism 105 slightly moves up, the serum quantitative pump 107 once sucks the sample into the sample cup 102. .. As a result, the inside of the nozzle tip 102 is always kept wet by the sample, and there are a case where the sample is sucked when the nozzle tip 102 is dry and a case where the sample is sucked when the nozzle tip 102 is wet. The nozzle tip 10 is designed to avoid the quantitative error caused by the above.
Even when 2 is reused, good quantitativeness can be maintained at all times. After this, the sampling pump 107
Sucks the sample by a predetermined amount, and then the serum pipetting mechanism 105 moves up to the upper stop point.

◎ Sample Dispensing Process (FIG. 16c) The serum pipetting mechanism 105 moves to the position of the sample dispensing stage RT of the reaction table 201. After that, the serum pipetting mechanism 105 is lowered, the tip of the nozzle tip 104 is brought close to the bottom of the cuvette, and the sample is discharged into the cuvette 202 by the sampling pump 107. Then, when the discharge of the sample is completed, the line is switched to the air pump 181 side, and the nozzle tip 104
Air is ejected from the tip of the nozzle, and the sample slightly attached around the nozzle tip 104 is also ejected into the cuvette 202.
The quantification accuracy is kept good. After this, the serum pipetting mechanism 105 moves up to the upper stop point.

Further, in this embodiment, if it is assumed that the inside of the nozzle tip 104 is clogged with, for example, the caviar of serum, the air sensing unit is used during the air ejection operation performed after the ejection operation of the sample is completed. 1
Since the nozzle 83 detects the pressure abnormality, the nozzle tip 104
The situation where the inspection is continued with the clogged is effectively avoided.

◎ Nozzle tip cleaning process (Fig. 16d,
(FIG. 13) The serum pipetting mechanism 105 moves to the washing tank 110 and then descends to an intermediate stop point to wash the outer wall of the nozzle tip 104 with the washing tank pump 165 and the inner wall of the nozzle tip 104 with the washing pump 168. .. Then, the line of the serum pipetting mechanism 105 is switched by the valve and connected to the flow path on the side of the air pump 181, and the washing water in the nozzle tip 104 is blown off, and the nozzle tip 104 is raised while air is ejected from outside the drawing. Air is blown onto the outer wall of the nozzle tip 104 by the nozzle to remove water droplets. When the water droplets are removed by the air as described above, the contamination of the nozzle tip 104 caused by the method of cleaning with a filter paper or the like is effectively avoided.

◎ Nozzle tip removal processing operation (FIG. 16e,
(FIG. 13) The serum pipetting mechanism 105 moves toward the tip attaching / detaching stage C using the notch 164 of the washing tank 110 at the intermediate stop point. At this time, the nozzle tip 104 engages with the locking groove 153 of the tip release lever 150 and moves together with the tip release lever 150. When the serum pipetting mechanism 105 reaches the tip attachment / detachment stage C, the serum pipetting mechanism 105 rises to the upper stop point, but the nozzle tip 104 is the tip release lever 1
Since the ascending operation is restricted by 50, the nozzle tip 104 inevitably falls off the sample pipette 106 of the serum pipetting mechanism 105 and falls, and engages with the tip locking groove 115 of the sample table 101. For this reason,
When another inspection item is inspected for the same sample or when reinspection is performed, the already cleaned nozzle tip 104 can be reused as it is.

Modified Example of Processing In this embodiment, if the notch is also provided on the side of the sample dispensing stage RT of the washing tank 110, the serum pipetting mechanism 10 is completed when the sample dispensing operation is completed.
5 can be moved up to the intermediate stop point and moved to the washing stage W and the tip attachment / detachment stage C at this position, and the number of steps of vertical movement of the serum pipetting mechanism 105 can be reduced. It is possible to simplify the whole processing system more than the example.
Further, in the case of using a diluent of the sample, after sucking a predetermined amount of the sample from the sample cup 102, the serum pipetting mechanism 105 is moved to the diluent stage SD, and the dilution pump 109 is used to remove the sample and the sample. The diluent may be poured into the dilution cup 103.

[0044]

As described above, according to the present invention as set forth in any one of claims 1 to 3, the tip of the sample pipette is brought into contact with the sample liquid surface by utilizing the gas ejection operation from the sample pipette. Since the time point is detected by the pressure change, without separately increasing the size and complexity of the device itself by separately using a member dedicated to the liquid level detection, in the state where the variation in the detection sensitivity due to the difference in the components and colors of the sample is eliminated, The liquid level of the sample can be detected accurately and easily. For this reason,
The amount of immersion of the tip nozzle of the sample pipette into the specimen can be kept constant, and the sampling accuracy of the specimen can be kept good accordingly.

In particular, according to the third aspect of the invention, in order to avoid the carry-over phenomenon, even if the nozzle tip of the tip of the sample pipette is detachably replaced for each sample, the tip hole diameter of the nozzle tip is changed. In order to maintain the discharge air pressure constant by accurately manufacturing only the nozzle, the chemical material of the nozzle tip (eg, conductive, non-conductive) and the physical properties of the nozzle tip (eg, density, weight), in other words, The liquid level of the sample can be detected extremely accurately without being affected by manufacturing variations. Therefore, compatibility between nozzle chips can be easily ensured while maintaining good liquid level detection accuracy without separately using a member dedicated to liquid level detection.

Further, according to the invention as set forth in any one of claims 4 to 6, it is possible to suppress the residual liquid of the sample on the inner and outer walls of the tip nozzle of the sample pipette to a minute amount at the time of the minute amount sampling, so that the sample sampling accuracy is good. Can be kept at

In particular, according to the invention of claim 6, the clogging of the sample pipette can be easily detected by the gas jetting operation, so that the safety of the automatic analyzer can be improved while simplifying the device. You can keep good.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of a sample sampling device of an automatic analyzer according to the present invention.

FIG. 2 is an explanatory view showing the operation of the sample sampling device of the automatic analyzer according to the first invention.

FIG. 3 is an explanatory view showing the operation of the sample sampling device of the automatic analyzer according to the second invention.

FIG. 4 is a perspective view showing an embodiment of an automatic analyzer to which the present invention is applied.

FIG. 5 is an explanatory plan view of the automatic analyzer according to the embodiment.

FIG. 6 is a front explanatory view of the automatic analyzer according to the example.

FIG. 7 is an explanatory cross-sectional view showing details of a sample table according to the example.

FIG. 8 is a plan view thereof.

FIG. 9 is a cross-sectional explanatory view of a serum pipetting mechanism according to an example.

FIG. 10 is an arrow view seen from the X direction in FIG.

FIG. 11 is a plan view of FIG. 9.

FIG. 12 is an explanatory view showing details of a sample pipette used in the examples.

FIG. 13 is a perspective view showing a specific configuration of a cleaning tank used in the examples.

FIG. 14 is an explanatory diagram showing details of a sampling assistance system using air used in an example.

FIG. 15 is an explanatory diagram showing details of the air sensing unit used in the embodiment.

FIG. 16 is an explanatory diagram showing an operation processing process of the sample sampling device in the example.

[Explanation of symbols]

k: sample, 1: sample cup, 2: sample aspirating and dispensing means,
3: sample chip, 4: gas supply means, 5: pressure change detection means, 6: pipette first lowering control means, 7: gas supply stop first stage, 8: pipette second lowering control means, 9: pipette suction control means, 10: Pipette return control means, 1
1: Reaction cell, 12: Gas supply means, 13: Pipette lowering control means, 14: Pipet dispensing control means, 15: Gas supply control means, 16: Pipette return control means, 17: Abnormal pressure detection means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Nakada 2-12-29 Imagawa Urayasu City, Chiba Prefecture (72) Inventor Takumi Sakamoto 12-21 Yoshizawa Town, Mito City, Ibaraki Prefecture (72) Akira Naruse Mito Ibaraki Prefecture City, Yoshizawa 12-78 (72) Inventor Yoshizawa Usawa 4010-24 Nishi-Akasaka, Nakaminato-shi, Ibaraki (72) Inventor Katsumi Hasegawa 298-3 (72) Inami, Hiratiso, Nakaminato-shi, Ibaraki Katsuta-shi, Ibaraki 3-17 Honcho (72) Inventor Katsunori Uchibori 174-1 Motoyoshida-cho, Mito City, Ibaraki Prefecture

Claims (6)

[Claims] 1. A predetermined amount of a liquid sample in a sample cup is sucked by a sample pipette for sample suction / dispensing, which is movable vertically and horizontally, and after the sample is dispensed into a reaction cell, a reaction is performed. In an automatic analyzer that dispenses a predetermined reagent into the cell and optically analyzes the reaction between the sample and the reagent, when aspirating the sample in the sample cup with a sample pipette, a small amount of gas from the sample pipette is used. The pipette first lowering step of lowering the sample pipette from the top stop position while discharging, and when the gas pressure in the sample pipette rises to a predetermined level, it is judged that the tip of the sample pipette has reached the liquid surface of the sample, The liquid level detection process that stops the gas discharge operation, and when the liquid level of the sample is detected in this liquid level detection process, the sample pipette is lowered by a very small specified amount The pipette second descending step of slightly dipping the tip nozzle into the sample, the sample aspiration performing step of performing the sample suction operation at the end of the pipette second descending step, and the sample at the end of the sample aspiration performing step A sample sampling method for an automatic analyzer, comprising: a pipette returning step of returning a pipette to an upper stop point position. 2. An automatic analyzer for optically analyzing a reaction between a liquid sample and a reagent dispensed in a reaction cell, and a sample pipette for sample aspirating and dispensing which is movable vertically and horizontally. And a sample suction / dispensing means for performing a sample aspirating operation in the sample aspirating stage, and a sample aspirating operation for the reaction cell in the sample dispensing stage, and a gas with a minute pressure in the sample pipette. While supplying gas to the sample pipette, a pressure change detecting means for detecting that the gas pressure in the sample pipette has risen to a predetermined level, and operating the gas supplying means to discharge the gas from the sample pipette with a minute pressure. The pipette first lowering control means for lowering the sample pipette from the upper stop position and the gas pressure in the sample pipette increased to a predetermined level by the pressure change detection means. Gas supply stopping means for stopping the operation of the gas supply means at the time of detecting the above, and when the gas supply stopping means operates, the sample pipette is lowered by a very small specified amount to slightly dip the tip nozzle into the specimen. The pipette second lowering control means, the pipette suction control means for executing the sample suction operation when the sample pipette lowering operation by the pipette second lowering control means is completed, and the sample suction operation by the pipette suction control means is completed A sample sampling device of an automatic analyzer, comprising: pipette return control means for returning the sample pipette to the upper stop point at a time point. 3. The sample sampling device for an automatic analyzer according to claim 2, wherein the sample pipette of the sample aspirating / dispensing means has a detachable nozzle tip. 4. A predetermined amount of a liquid sample in a sample cup is sucked by a sample pipette for sample suction / dispensing, which is movable vertically and horizontally, and after the sample is dispensed into a reaction cell, the reaction is performed. In an automatic analyzer that optically analyzes the reaction between a sample and a reagent by dispensing a predetermined reagent into the cell, when dispensing the sample into the reaction cell with a sample pipette, the sample sampling volume in the reaction cell Pipette lowering process that lowers the sample pipette from the top stop position to a position close to the surface level, sample dispensing execution process that executes the sample dispensing operation when this pipette lowering process is completed, and this sample dispensing At the end of the execution process, at least while the sample pipette is located near the liquid level of the sample sampling volume, discharge the gas from the sample pipette and And a pipette returning step of returning the rupipette to the upper stop point position. 5. An automatic analyzer for optically analyzing the reaction between a liquid sample dispensed in a reaction cell and a reagent, in a sample pipette for sample aspirating and dispensing movable vertically and horizontally. And a sample suction / dispensing means for performing a sample aspirating operation on the sample aspirating stage and a sample aspirating operation on the reaction cell at the sample dispensing stage, and a gas of a predetermined pressure in the sample pipette. Gas supply means for supplying the sample pipette, pipette lowering control means for lowering the sample pipette from the upper stop position to a position close to the sample dispensing amount liquid level in the reaction cell, and lowering of the sample pipette by this pipette lowering control means. Pipette dispensing control means for executing the sample dispensing operation when the operation is completed, and gas supply means when the sample dispensing operation by the pipette dispensing control means is completed An automatic gas supply control means for operating the sample pipette for a predetermined time, and a pipette return control means for returning the sample pipette to the upper stop position when the sample dispensing operation by the pipette dispensing control means is completed. Analyte sample sampling device. 6. The apparatus according to claim 5, further comprising an abnormal pressure detecting means for detecting that the gas pressure in the sample pipette has risen to an abnormal level during the gas supply operation by the gas supply control means. Sample analyzer of automatic analyzer.