JPH0345340B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a preparative dispensing apparatus, and more particularly to an apparatus for separating a viscous specimen such as serum and dispensing it into a sample cup.

Description of Prior Art FIG. 1 is a diagram schematically showing a blood analysis system as an example of an automatic dispensing analysis system that is the background of the present invention. Generally, in such a dispensing analysis system, when a request for an analysis test is received, blood is collected. Then, the blood is separated into serum and blood by a method such as centrifugation.
The blood specimen thus separated is quantitatively dispensed into required sample cups by an automatic preparative/dispensing device. The sample cup into which the serum has been dispensed is subjected to a predetermined analysis using an analyzer or a manual method, and is also stored as necessary. On the other hand, when a request for testing is received, a worksheet is created to be referred to along with the analysis results from the analyzer or manual.
Predetermined items such as a sample confirmation number and patient name are written on the worksheet.

The present invention is directed to improving the automatic sorting and dispensing apparatus 100 used in such a dispensing and analyzing system.

For example, by opening a solenoid valve in a nozzle system for a predetermined period of time, a fixed amount of collected serum can be dispensed. However, the amount of serum flowing through the nozzle system per unit time changes depending on the viscosity of the serum, so even if the solenoid valve is opened for a certain period of time, if the temperature of the serum differs significantly or if the subjects are different, Since the viscosity of the serum differs, there is a problem in that the dispensed amount changes.

Purpose of the Invention Therefore, in this invention, even in a preparative dispensing device that performs quantitative dispensing by time control, it is possible to always perform stable quantitative dispensing without being affected by changes in the viscosity of the sample. The purpose is to provide a sampling and dispensing device.

SUMMARY OF THE INVENTION To put it simply, the present invention is a preparative dispensing device that separates a viscous sample and then dispenses it in a quantitative manner. The system obtains information such as the time required for the liquid to flow through a certain section, and controls the dispensing time based on this information during dispensing.
It is a preparative dispensing device.

Effects of the Invention According to the present invention, information regarding the viscosity of the specimen is obtained at the time of preparative sampling, and during subsequent dispensing, for example, the opening time of a solenoid valve is controlled based on the information regarding the viscosity. Even if the viscosity of the liquids differs, stable quantitative dispensing can be performed.

DESCRIPTION OF EMBODIMENTS FIG. 2 is a schematic diagram showing an embodiment of the present invention. The blood in the sample container 1 is separated into blood 3 in the lower layer and serum 5 in the upper layer by a method such as centrifugation. The sample container 1 is
It is held substantially vertically by a holding means (not shown). A nozzle head 7 is arranged above the sample container 1, and this nozzle head 7 is integrally attached to a lifting table 702.

The nozzle head 7 will now be described in detail with reference to FIG. A nozzle 704 made of, for example, a stainless steel tube for aspirating the serum 5 in the sample container 1 and an optical fiber 706 are attached to the lifting table 702 so as to be able to move up and down substantially parallel to each other and constantly. Optical fiber 706 is used to detect the boundary between blood plaque 3 and serum 5. For that purpose, this optical fiber 706 has a reciprocating optical path and its tip 706a faces into the sample container 1. The other end 706b of the optical fiber 706
A light emitting means 710 such as a light emitting diode and a light emitting means such as a phototransistor are optically coupled to and 706c, respectively. The light emitting means, ie, the light emitting diode 710, and the light receiving means, ie, the phototransistor 712, cooperate to form a photodetector 708. light emitting diode 7
The light from 10 enters the optical fiber from one end 706b, is reflected by its tip 706a, and reaches the other end 706c. The output of the phototransistor 712 coupled to the other end 706c is applied to the boundary surface detection circuit 23 (FIG. 2). Note that this optical fiber 706 has a sheath 7 as shown in FIG.
06' is fitted, and due to the change in resistance (current) between this sheath 706' and ground potential (GND),
As will be described later, it is possible to detect that the nozzle has entered the serum liquid level.

A tube 716 made of a resin material such as Teflon (trade name) is connected to the other end of the nozzle 704 for transporting the collected serum or the serum to be dispensed. This tube 716
An electrode pair 714 made of, for example, a stainless steel tube is provided in the middle for detecting air bubbles. Electrode pair 714 includes an electrode 714a connected to ground potential and an electrode 714b spaced a predetermined distance from electrode 714a. This electrode 714a
and 714b are both the bubble detection circuit 21
(Fig. 2).

Returning to FIG. 2 again, the tube 716 is connected to the tank 11 through the solenoid valve 9. This tank 11 is connected to a pneumatic circuit 13 which is connected to a compressed air source 15 . Therefore, during fractionation, the tank 11 is brought into a negative pressure state by the pneumatic circuit 13, and the serum 5 is dispersed into the tank 11 from the nozzle 704 through the tube 716. During dispensing, an appropriate positive pressure is applied to the tank 11 by the pneumatic circuit 13, and by controlling the opening/closing time of the solenoid valve 9, the tube 716 and nozzle 70 are
4, a certain amount of serum is dispensed into a sample cup (not shown). A light emitting diode 710 included in the photodetector 708 is connected to a light emitting power source 17, and the light emitting power source 17 is, for example, an AC power source.

The ground electrode 714a of the sheath 706' of the optical fiber 706 is both connected to the input of the serum level detection circuit 19. Electrode pair 714a and 714b
is connected to the input of the bubble detection circuit 21. The operations of these circuits 19 and 21 will be described later, and their outputs are provided to a microprocessor 25, respectively. The microprocessor 25 is further supplied with the output of the boundary surface detection circuit 23 which receives the output from the phototransistor 712. The microprocessor 25 includes, in its attached memory, a preparative timer counter for counting the time at the time of dispensing and a dispensing timer counter for controlling the time at the time of dispensing. microprocessor 25
gives a signal to appropriately control the electromagnetic valve 9 at the time of fractionation and dispensing, and also gives a signal to the pneumatic circuit 13 to control the negative pressure or positive pressure in the tank 11.

The nozzle lifting mechanism 27 is connected to the lifting table 702 of the nozzle head 7 and is controlled by the microprocessor 25. Therefore, the nozzle elevating mechanism 27 controls the elevating and lowering of the nozzle head 7, and controls the movement of the nozzle 704 into and out of the sample container 1 or to the sample cup (not shown) position.

4 and 5 are flowcharts for explaining the operation of the embodiment shown in FIG. 2, respectively, with FIG. 4 showing the sorting operation and FIG. 5 showing the dispensing operation.

First, referring to FIG. 4, the sorting operation of the embodiment shown in FIG. 2 will be explained. First, in step 101, the microprocessor 25 is initialized in response to, for example, turning on a power switch (not shown), and a control signal is applied from the microprocessor 25 to the nozzle lifting mechanism 27. Therefore, the elevator platform 702 starts descending at high speed. Therefore, the nozzle 704 and optical fiber 7 that are integrally attached to this lifting platform 702
06 both descend into the sample container 1 at high speed. At this time, the serum level detection circuit 19 detects whether the tip of the nozzle 704 has entered the serum 5 (FIG. 2) from the resistance change between the nozzle 704 and the sheath 706' of the optical fiber 706. .
If a large change occurs in this resistance value, the serum level detection circuit 19 generates a detection signal, and the microprocessor 25 provides a control signal to the nozzle lifting mechanism 27 in response to the detection signal. In response to this control signal, the nozzle elevating mechanism 27 moves to the elevating table 702.
Switch to low speed descent. This is to improve positioning accuracy. (Step 102 and
103).

When the nozzle 704 descends at a low speed and reaches near the boundary between the serum 5 and the blood clot 3 in the sample container 1, a signal is subsequently obtained from the interface detection circuit 23, and the microprocessor 25 in step 104 ,
Detect the boundary surface. Note that such boundary surface detection can be determined by observing the amount of light received by the phototransistor optically coupled to the other end 706c of the optical fiber 706. That is, the other end 7 of the light incident from one end 706b of the optical fiber 706
If the amount of reflection toward 06c becomes large, it is determined that it is a boundary surface. Once the interface detection signal is obtained from circuit 23, microprocessor 25 then provides a control signal to nozzle lift mechanism 27 in step 105 to stop lowering the nozzle.

Subsequently, the microprocessor 25 generates control signals and applies them to the pneumatic circuit 13 and the solenoid valve 9. In response to this control signal, the pneumatic circuit 13 is switched, the tank 11 is placed in a negative pressure state, and the solenoid valve 9 is opened. Therefore, tank 1
1 is connected to tube 716, and serum 5 begins to be aspirated from nozzle 704 (step 106). At the same time as this serum suction starts, the microprocessor 25
starts a distributed timer counter formed in its memory (not shown) (step 107).
This fractionation timer counter may be of such a type that its count value is incremented in response to a certain clock.

The bubble detection circuit 21 detects the presence or absence of bubbles based on the change in resistance value between electrodes placed between the nozzle 704 and the tube 716. That is, when suction of the serum 5 is started, air flows between the electrodes for a while, and then the serum 5 reaches between the electrodes.
and 714b (FIG. 3), the resistance value, ie, the current value, changes rapidly. Furthermore, if serum up to the level of the tip of the nozzle 704 is suctioned, this nozzle will suck in outside air, and air bubbles will enter the tube 716, causing the pair of electrodes 714a
The current value between 714b and 714b changes rapidly due to the passage of this bubble. The bubble detection circuit 21 detects such changes, ie the arrival of the serum 5 and the passage of the bubbles, and generates a detection signal.

The microprocessor 25 operates in this bubble detection circuit 2.
The count value of the distributed timer counter is sequentially stored in a predetermined area of the memory until a signal corresponding to the arrival of serum from 1 is received (steps 108 and 109).
Then, when a signal corresponding to bubble detection is obtained from the bubble detection circuit 21 (step 110), the microprocessor 25 gives a control signal to the solenoid valve 9 in the following step 111, and the solenoid valve 9 is closed accordingly. . In this way, the serum suction operation is stopped.

When the suction operation is stopped in response to such air bubble detection, the microprocessor 25 generates a control signal and supplies it to the nozzle lifting mechanism 27. Accordingly, nozzle lifting mechanism 27 raises lifting table 702 and stops it when a predetermined upper limit is reached (steps 112 and 113).

In this way, in the dispersion operation, the fractionation timer counter operates, and the time from the start of serum suction until the serum reaches the bubble detection electrode 714b is stored in a predetermined area of the memory. In this example,
This time is used to control or correct the dispensing time.

Next, the dispensing operation will be explained with reference to FIG. First, in step 201, the nozzle is lowered at high speed in the same manner as step 101 in FIG. Then, when the nozzle 704 reaches a predetermined dispensing position on the sample cup (not shown) (step 202), the microprocessor 25 executes the next step.
At step 203, nozzle descent is stopped in the same manner as step 105 of FIG. Next steps
At 204, the dispensing time for a predetermined dispensing amount, that is, the time during which the solenoid valve 9 is opened, is set in the dispensing timer counter. This dispensing timer counter can also be formed using a certain area of memory in the same way as the dispensing timer counter.

In step 205, the microprocessor 25
reads the count value of the dispensing timer counter which is incremented sequentially during the dispensing operation, and corrects the time set in the dispensing timer counter based on the read count value of the dispensing timer counter.

This correction will now be explained with reference to FIGS. 6 and 7.

The relationship between the sample temperature, that is, the sample viscosity, the suction time, and the dispensed amount is shown in FIG.
That is, the higher the sample temperature, the lower the viscosity of the sample (serum), and therefore the shorter the time from the start of fractionation to the detection of serum arrival. Conversely, if the sample temperature is low, its viscosity increases, and the time required to aspirate a certain period of time increases. On the other hand, regarding the amount to be dispensed, the higher the sample temperature, the larger the amount of sample that can be dispensed within a certain period of time.
This is because when the sample temperature is high, the viscosity of the sample is low, and therefore the flow rate per unit time is large. Conversely, if the sample temperature is low, the amount of sample dispensed within a fixed dispensing time will be smaller.

In this embodiment, in order to simplify the correction calculation, FIG. 6 is approximated to the straight line shown in FIG. 7. 7th
In the figure, the horizontal axis shows the specimen temperature T (° C.), and the vertical axis shows the suction time t (mees) and the dispensing amount V (ml).

In FIG. 7, the suction time t and the dispensing amount V at the sample temperature T are calculated using the following equations (1) and (2), respectively.
is given by

t=-kT+t1...(1) V=KT+V1...(2) However, k and K each represent a coefficient.

Here, the sample when T=T ₀ is used as the standard sample,
If the aspiration time for the standard sample is t ₀ and the dispensing amount is V ₀ , then from equations (1) and (2) above, the following equation (3) can be obtained.
and (4) are given.

t ₀ = −kT ₀ + t1 ...(3) V ₀ =KT ₀ +V1 ...(4) From equations (1) to (4) above, the dispensing amount V at any sample temperature T and the standard temperature T ₀ The following equation (5) holds true with the standard dispensing amount V ₀ .

V-V ₀ =K/k(t ₀ -t) (5) Therefore, by dividing the above equation (5) by V ₀ and transforming it, the following equation (6) can be obtained.

V ₀ /V=V ₀ /V ₀ +K/k(t ₀ -t) ...(6) Therefore, the dispensing volume V is the dispensing volume of the standard sample.
In order to correct the on (opening) time of the solenoid valve 9 to be equal to V ₀ , the on (opening) time of the solenoid valve 9 must be adjusted to be equal to V ₀ /
It is sufficient to multiply by {V ₀ +K/k(t ₀ −t)}.

In addition, in actual correction, V ₀ /
V can be approximately found as a function of t.

In this way, the suction time t read during the preparative operation
The time set in the dispensing timer counter is corrected based on the data. The microprocessor 25 then provides a control signal to the solenoid valve 9 in step 207. In response, the solenoid valve 9 is opened, and the tank 11 and the tube 716 are brought into communication, and serum begins to be discharged from the tank 11 through the nozzle 704. At this time, the microprocessor 25 controls the pneumatic circuit 13 to close the tank 11 and the tube 716. 11 to a constant positive pressure. microprocessor 25
After outputting a control signal to the solenoid valve 9, the dispensing operation continues until the dispensing timer counter corrected in the previous step 206 becomes zero (steps 208 and 209). Note that step 210 is a step for detecting when the inside of the tank 11 is empty, and this step is also performed in the same way as step 108 in FIG.
This can be determined by looking at the signals from.

In this way, when the dispensing timer counter set to the corrected time becomes zero (or when the tank 11 becomes empty), the microprocessor 2
5 outputs a control signal for closing the solenoid valve 9 in the following step 211. In this way, dispensing from tank 11 is stopped. Thereafter, in steps 212 and 213, the nozzle is raised in the same manner as in steps 112 and 113 of FIG. In this way, one dispensing operation is performed.

In addition, in the above-mentioned embodiment, the case where the same nozzle is used for the sorting operation and the dispensing operation was explained.
However, the nozzle system for preparative collection and the nozzle system for dispensing do not necessarily have to be the same, and even if they are provided separately, the dispensing time can be corrected using the same concept. .

Furthermore, in the above-described embodiments, serum was used as an example of a viscous specimen. however,
It goes without saying that the specimen to which the present invention is applied is not limited to such serum, but can be applied to all specimens whose viscosity varies depending on, for example, temperature or subject differences.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of a dispensing analysis system that is the background of the present invention. FIG. 2 is a schematic diagram showing an embodiment of the present invention. FIG. 3 is an illustrative view showing an example of the nozzle head used in the embodiment shown in FIG. 4 and 5 are flowcharts for explaining the operation of the embodiment shown in FIG. 2, respectively, with FIG. 4 showing the sorting operation and FIG. 5 showing the dispensing operation. FIGS. 6 and 7 are graphs for explaining a specific example of controlling the dispensing time using the information regarding the viscosity obtained during the dispensing operation. In the figure, 1 is a sample container, 5 is serum, 7 is a nozzle head, 9 is a solenoid valve, 11 is a tank, and 25 is a microprocessor.

Claims (1)

[Scope of Claims] 1. A preparative dispensing device for separating and quantitatively dispensing a viscous sample, comprising: a preparative nozzle for preparatively dispensing a viscous sample; a container for accommodating a sample; a depressurizing means for reducing the pressure of the container in order to separate the sample; a measuring means for measuring the time required for a sample to flow through a predetermined section; a dispensing nozzle for dispensing the sample; and a container for dispensing the sample from the dispensing nozzle. a pressurizing means for pressurizing the sample, an opening/closing means for opening and closing the sample transport channel between the dispensing nozzle and the container, and a predetermined amount of the sample being dispensed from the dispensing nozzle. and control means for controlling the opening/closing means based on measurement time data of the measuring means. 2. The preparative dispensing device according to claim 1, wherein the preparative nozzle and the dispensing nozzle are the same nozzle. 3. The control means includes: a setting means for setting a dispensing time when dispensing a reference sample; and a setting means for setting a dispensing time when dispensing a reference sample; and a setting means for setting a dispensing time when dispensing a reference sample; and a correction means for correcting the dispensing time set by the setting means based on the measurement data obtained from the measurement means when dispensing the liquid. preparative dispensing device.