JPH05164765A - Automatic chemical analysis device - Google Patents

Abstract

PURPOSE:To perform highly accurate chemical analysis based on the accurate volume of each liquid drop actually dropping down from a nozzle by photoelectrically measuring the projected shapes of the liquid drops and highly accurately calculating the volume of each liquid drop from its shape. CONSTITUTION:A light source section 11a is composed of a semiconductor laser and cylindrical lens and emits a line beam upon the route of the liquid drop of a sample 1 discharged from a nozzle 2a to a reaction tube 5a in the direction perpendicular to the route. A photodetector 11b composed of a lens and line sensor detects a change in light quantity produced when the liquid drop of the sample 1 intercepts the line beam. The signal of the photodetector 11b is sent to an arithmetic and control device 10 after the signal is digitized by means of a signal processing circuit 11c composed of an amplifier, binarization circuit, etc. The device 10 detects the start and end of line beam interception by each liquid drop and stores data at every scanning time after each liquid drop starts to intercept the beam by performing arithmetic processing on the input data and finds the dispensed amount of the sample 1 by finding the volume of each drop by performing spherical approximation based on the data collected while each drop crosses the line beam.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic chemical analyzer used in the field of clinical examination, and more particularly to a technique for accurately quantifying a liquid amount when a small amount of a body fluid sample is dispensed.

[0002]

2. Description of the Related Art In recent years, various medical tests such as blood and urine tests have become indispensable factors for medical diagnosis. In addition, the number of items to be analyzed in one sample is increasing with the diversification of test items such as automation of immunoassay tests using antigen-antibody reaction. It may also lead to lower recovery of blood collection from the patient. Therefore, it is necessary to reduce the amount of sample used in the analyzer. Conventionally, to meet such demands, we have adopted a method that controls the dispensing syringe with a precision screw and a stepping motor to ensure the quantitativeness of the dispensing and dispensing (pulse count quantitative) method, and the mechanical performance is satisfied. Was there.

[0003]

However, the amount of the sample finally dispensed to the reaction tube due to the adhesion of the sample to the nozzle or the like due to the miniaturization of the dispensed sample is quantified by the drive unit. This results in an error, resulting in a decrease in analysis accuracy.
This has hindered the promotion of miniaturization.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to accurately measure the amount of a small amount of sample or reagent discharged and supplied from a dispensing nozzle. It is to enable highly accurate chemical analysis based on the liquid volume.

[0005]

[Means for Solving the Problems] Dispensing and discharging means for supplying a sample or a reagent as fine droplets from the tip of a nozzle, and a line-shaped light beam is emitted substantially horizontally so as to intersect the drop path of the droplets. Beam generating means, a two-dimensional imaging means that is arranged to face the beam generating means so as to sandwich the drop path, and receives the linear light beam, and the droplet drops across the linear light beam. 2 when doing
A droplet quantitative processing means for recognizing the projected shape of the droplet from the output signal of the three-dimensional imaging means and calculating the amount of the droplet is added to the automatic chemical analyzer.

[0006]

Operation: The projected shape of the droplet actually dropped from the nozzle is photoelectrically measured, and the droplet amount is calculated with high accuracy, without depending on the quantitative accuracy of the dispensing and discharging means. can do.

[0007]

1 is a schematic perspective view of an automatic chemical analyzer according to an embodiment of the present invention. A sample part (sample part) 2 in which a plurality of sample containers 1a for receiving a sample 1 such as serum collected from a human body are arranged, and a reagent part having a reagent container 3a containing a reagent 3 corresponding to a test item for each type. 4 and a reaction part 5 having a plurality of reaction tubes 5a for mixing and reacting the sample 1 and the reagent 3. In addition, an operation unit 6 for inputting information such as test items and a photometry unit 7
It has a display device 8 and a printer 9 for displaying the results measured by the above, and an arithmetic and control unit 10 for controlling the entire device and arithmetically processing the measurement data.

In the sample section 2, the sample suction / dispensing mechanism 2b for sucking and dispensing the sample 1 in the sample container 1a selects a desired sample under the control of the arithmetic and control unit 10 and selects a predetermined amount of sample. After being sucked from the sample nozzle 2a, it is configured to be dispensed into a predetermined reaction tube 5a of the reaction section 9 via a sensor 11 according to the present invention.

The reagent section 4 sucks and dispenses the reagent 3 from the nozzle 4a corresponding to the test item of the reagent container 3a. As a means for this, it has a reagent suction / dispensing mechanism 4b, and this reagent suction / dispensing mechanism 4b selects a desired reagent container 3a under the operation control device 10 and sucks a predetermined amount of reagent 3. After that, it is configured to dispense into a predetermined reaction tube of the reaction section 5.

The reaction section 5 is a stirring section 12 for stirring the mixed liquid of the sample 1 and the reagent 3 dispensed in the reaction tube 5a.
A photometric section 7 for colorimetric measurement of the stirred mixed solution, a cleaning section 13 for cleaning the inside of the reaction tube 5a before and after the analysis, and a fixed mixture solution in the reaction tube 5a for stable measurement. It has a constant temperature part 14 for keeping the temperature.

The photometric unit 7 includes a light source 7a, a diffraction grating 7b that transmits the light from the light source to the mixed liquid of the sample and the reagent in the reaction tube 5a, and disperses the transmitted light for each wavelength.
It has a detection system including a detector 7c for detecting the absorbance of each wavelength after dispersion, and detects the reaction state of this mixed solution as the absorbance.

An embodiment in which the present invention is applied to sample dispensing will be described with reference to FIG.

As shown in the drawing, a diluting container 16 for accommodating a diluting liquid for diluting or washing the sample is connected to a syringe 15 for sucking and discharging the sample via a liquid feed pump 17 and an electromagnetic valve 18. Has been done. The syringe 15 is configured to slide the piston 15a up and down by a stepping motor 19 and a drive screw 20. The sliding of the piston 15a
The arithmetic and control unit 10 drives and controls the detection signal of the position detector 21 at the top dead center of the piston 15a as a reference point. The other discharge side of the syringe 15a is connected to the sample nozzle 2a.
Up to

The droplet quantitative sensor 11 uses a semiconductor laser as a light source, and a light source section 11a which emits a linear light beam (hereinafter referred to as a line beam) by a cylindrical lens.
It is composed of a photodetector 11b that detects the line beam emitted from the light source unit 11a at an opposed position, and a signal processing circuit.

FIG. 3 shows the details of the detection system of the droplet quantitative sensor 11. The light source unit 11a includes a semiconductor laser and a cylindrical lens, and emits a line beam in a direction perpendicular to a path of the droplet of the sample 1 ejected from the nozzle 2a to the reaction tube 5a. The photodetector 11b including a lens and a line sensor detects a change in the light amount by the droplet of the sample 1 blocking the line beam. The signal from the photodetector 11b is sent to the digitized arithmetic and control unit 10 by a signal processing circuit 11c including an amplifier and a binarization circuit. The arithmetic and control unit 10 performs arithmetic processing on the input data to detect the start of droplet passage, store the data for each scanning time from when the beam starts to be blocked, and detect the end of passage, and based on the data collected during passage. Spherical approximation is performed to determine the volume, and use this as the dispensing amount for Sample 1.

The relationship between the droplet of sample 1 and the signal from photodetector 11b as it traverses the line beam is shown in FIG. In A, all the data are “0” in the state before passing the droplet. B shows a state in which a change in the light amount due to the tip of the droplet is detected. The shaded area in the figure represents the interruption "1" by the droplet. The following data is used to detect the start of droplet passage.
After confirming that it is not a detection signal due to noise, that is, it is validated and storage is started. C to E are explanatory diagrams of data for each scanning time and are stored at any time. FG is
When the passage end is detected, the passage is ended when G is detected, and the arithmetic processing of the stored data is started with this detection. Also, when a few drops are dispensed, the interval is
It is controlled by the arithmetic and control unit 10.

FIG. 5 shows a schematic configuration of a signal processing system of the automatic chemical analyzer. The arithmetic and control unit 10 includes a CPU as a means for performing the operation of the entire apparatus and the arithmetic processing of measurement data.
10a and a memory 10b for storing test items input to the operation unit 6 and reagent information corresponding to the test item information.
And a program memory 10c in which a series of operation commands for executing the analysis based on the test item information are stored as a program. Arithmetic control device 1
An operation unit 6, a display unit 8, a printer 9, a reagent suction / dispensing mechanism 4b, a sample suction / dispensing mechanism 2b, a droplet quantitative sensor 11, and a reaction unit 9 are electrically connected to 0.

Next, the overall operation of this apparatus will be described with reference to the flowchart of FIG. When a start key (not shown) of the operation unit 6 is pressed, a start signal is sent to the CPU 10
a to the program memory 10
The program stored in c is read and the preparation is completed. Next, when information such as a test item is input to the operation unit 6, the CPU 10a stores the test item information in the memory 10.
b, then the cleaning unit 13 is controlled and the reaction tube 5a
Clean the inside. Then, the CPU 10a uses the cleaning unit 13
Is controlled to dispense pure water into the reaction tube, the photometric unit 7 is subjected to water blank measurement, and the pure water used for measurement is discharged after the measurement is completed.

The CPU 10a searches the test item information stored in the memory 10b, and the sample suction / dispensing mechanism 2
The sample 1 of the sample part 2 is sucked into b, and the sucked sample 1 is dispensed into the cleaned reaction tube. When ejecting to the reaction tube, the syringe drive mechanism is controlled to form a droplet, and when the droplet passes through the droplet quantification sensor 11, the shape is measured as described above, and the ejected droplet is quantified from the result. . The quantified sample amount is stored in the memory 10b of the arithmetic and control unit 10.
Are stored together with the reaction tube 1D.

Next, the CPU 10a retrieves the test item information stored in the memory 10b and retrieves the reagent suction / dispensing mechanism 4.
By controlling b, the reagent 4 corresponding to the information of the test item input from the operation unit 6 is sucked. Reagent suction and dispensing mechanism 4b
Dispenses the aspirated reagent 3 to the reaction tube 5a of the reaction section 9 under the control of the CPU 10a. The reaction tube 5a into which the sample 1 and the reagent 3 have been dispensed is agitated and mixed by the agitation unit 12. Subsequently, the reaction tube 5a containing the reaction liquid mixed with stirring is subjected to photometry by the photometry section, and the photometry result information is stored in the CPU 1
Sent to 0a. The CPU 10a performs the sample amount correction calculation using the received photometric result information and the sample amount measured at the time of sample dispensing and stored in the memory 10b. The calculation formula in the oxygen activity measurement is as follows.

IU / L = (ΔE / min) × (ε) × (1 / L) × (V _T / V _s ) × (TC) IU / L: Activity value ΔE / min: per minute Absorbance value ε: Molecular extinction coefficient L: Cell length V _T / V _s : Final reaction solution volume {(reagent amount + sample amount) / sample amount} T.I. C: Temperature coefficient The term of V _T / V _{s in} the above equation may be corrected for each sample. The result of the arithmetic processing as described above is displayed on the screen and printed out by the printer 9.

Under the control of the CPU 10a, the cleaning unit 13 discharges the reaction liquid in the reaction tube 5a whose analysis has been completed, cleans the reaction tube 5a, and completes the measurement.

[0023]

According to the present invention described in detail above, since the sample amount and the reagent amount that truly contributed to the reaction can be accurately quantified by measuring the shape of the ejected liquid droplet, the trace amount with high accuracy can be obtained. It enables pouring, and the increase in items can be realized without increasing the blood collection amount. As a result, it is possible to obtain effective clinical data over multiple items and make more accurate diagnosis.

[Brief description of drawings]

FIG. 1 is an overall view of an automatic chemical analyzer according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a sample dispensing mechanism in the same apparatus.

FIG. 3 is a detailed view of a droplet quantitative sensor in the same apparatus.

FIG. 4 is an operation explanatory diagram of the same sensor.

FIG. 5 is a block diagram of a signal processing system of the same apparatus.

FIG. 6 is a flowchart showing the overall operation of the above apparatus.

[Explanation of symbols]

 1 sample 1a sample container 2 sample part 2a sample nozzle 3 reagent 3a reagent container 4 reagent nozzle 4a reagent aspirating and dispensing mechanism 5 reaction part 5a reaction tube 6 operation part 11 droplet quantitative sensor 11a light source part 11b photodetector 11c signal processing circuit 12 Stirring Section 13 Washing Section 14 Constant Temperature Section 15 Syringe 15a Piston 16 Dilution Container 17 Liquid Transfer Pump 18 Electromagnetic Valve 19 Stepping Motor

Claims (1)

[Claims] 1. Dispensing and ejecting means for supplying a sample or reagent from the tip of a nozzle as minute droplets, and beam generating means for emitting a linear light beam substantially horizontally so as to intersect the drop path of the droplets. And a two-dimensional image pickup means that is arranged to face the beam generation means across the fall path and receives the linear light beam; and the two-dimensional image pickup means when the droplet drops across the linear light beam. An automatic chemical analyzer comprising: a droplet quantitative processing means for recognizing the projected shape of the droplet from the output signal of the two-dimensional image pickup means and calculating the amount of the droplet.