U.S. patent application number 10/943245 was filed with the patent office on 2005-05-05 for chemical analyzer, method for dispensing and dilution cup.
This patent application is currently assigned to KABUSHIKI KAISHA TOSHIBA. Invention is credited to Sato, Naoto, Shibutani, Hitoshi.
Application Number | 20050095724 10/943245 |
Document ID | / |
Family ID | 34191401 |
Filed Date | 2005-05-05 |
United States Patent
Application |
20050095724 |
Kind Code |
A1 |
Shibutani, Hitoshi ; et
al. |
May 5, 2005 |
Chemical analyzer, method for dispensing and dilution cup
Abstract
A method for dispensing a sample solution and a reagent into a
container in a chemical analyser includes a first step of
dispensing a reagent into a container, a second step of dispensing
a sample solution into the container after the first step, and a
third step of dispensing the reagent into the container after the
second step. A dilution cup includes an inner face where a diameter
of a horizontal section increases on at least one position from a
bottom to a top, an opening portion surrounding an opening, where a
sample solution is dispensed, located on or near the top, a reagent
aperture portion surrounding an aperture where a reagent is
dispensed such that the sample solution and the reagent create an
upswing spiral flow, and a drain aperture portion surrounding a
drain aperture, where a mixed solution of the sample solution and
the reagent is discharged, located on or near the bottom.
Inventors: |
Shibutani, Hitoshi;
(Otawara-shi, JP) ; Sato, Naoto; (Nasu-Gun,
JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
KABUSHIKI KAISHA TOSHIBA
Tokyo
JP
TOSHIBA MEDICAL SYSTEMS CORPORATION
Otawara-Shi
JP
|
Family ID: |
34191401 |
Appl. No.: |
10/943245 |
Filed: |
September 17, 2004 |
Current U.S.
Class: |
436/180 ;
422/400; 422/64 |
Current CPC
Class: |
Y10T 436/2575 20150115;
G01N 2035/1058 20130101; Y10T 436/115831 20150115; G01N 2035/00544
20130101; G01N 35/10 20130101; Y10T 436/25625 20150115; Y10T
436/116664 20150115 |
Class at
Publication: |
436/180 ;
422/102; 422/064 |
International
Class: |
B01L 003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 19, 2003 |
JP |
P2003-328603 |
Claims
What is claimed is:
1. A method for dispensing a sample solution and a reagent into a
container in a chemical analyser, comprising: a first step of
dispensing a reagent into a container; a second step of dispensing
a sample solution into the container after the first step; and a
third step of dispensing the reagent into the container after the
second step.
2. The method according to claim 1, wherein total amount of the
reagent dispensed in the first step and the third step corresponds
to amount which is required for obtaining a biochemistry test
array.
3. The method according to claim 2, wherein the amount of the
reagent dispensed in the first step is smaller than the amount of
the regent dispensed in the third step.
4. The method according to claim 3, wherein speed of dispensing of
the reagent in the third step is faster than speed of dispensing of
the reagent in the first step.
5. The method according to claim 3, wherein the second step
includes a step of soaking a top of a probe for dispensing the
sample solution to the reagent dispensed in the first step.
6. A dilution cup, comprising: an inner face where a diameter of a
horizontal section increases on at least one range from a bottom to
a top; an opening portion surrounding an opening, where a sample
solution is dispensed, located on or near the top; a reagent
aperture portion surrounding an aperture where a reagent is
dispensed such that the sample solution and the reagent create an
upswing spiral flow; and a drain aperture portion surrounding a
drain aperture, where a mixed solution of the sample solution and
the reagent is discharged, located on or near the bottom.
7. The dilution cup according to claim 6, wherein a shape of the
horizontal section is approximately circular.
8. The dilution cup according to claim 7, wherein the reagent
aperture portion is located above the drain aperture portion.
9. The dilution cup according to claim 8, wherein a flow direction
of the reagent dispensed from the reagent aperture is approximate
horizontal.
10. The dilution cup according to claim 9, wherein an axis which
extends from the reagent aperture in the flow direction is shifted
from a vertical central axis of the inner face.
11. A chemical analyser, comprising: a container where a sample
solution and a reagent are mixed; a first mechanism configured to
dispense the reagent into the container; a second mechanism
configured to dispense the sample solution in to the container; and
a controller configured to control the first mechanism to dispense
the reagent in a first step, the second mechanism to dispense the
sample solution in a second step after the first step, and the
first mechanism to dispense the reagent in a third step after the
second step.
12. The chemical analyser according to claim 11, wherein the
controller controls the first mechanism such that total amount of
the reagent dispensed in the first step and the third step
corresponds to amount which is required for obtaining a
biochemistry test array.
13. The chemical analyser according to claim 12, wherein the
controller controls the first mechanism such that amount of the
reagent dispensed in the first step is smaller than amount of the
reagent dispensed in the third step.
14. The chemical analyser according to claim 11, wherein the
controller controls speed of dispensing of the reagent and the
sample solution.
15. The chemical analyser according to claim 14, wherein the speed
of dispensing of the reagent in the third step is faster than the
speed of dispensing of the reagent in the first step.
16. The chemical analyser according to claim 12, wherein the second
member includes a probe, which dispenses the sample solution into
the container when a top of the probe contacts a surface of the
reagent dispensed in the first step.
17. The chemical analyser according to claim 11, wherein the
container is a dilution cup.
18. The chemical analyser according to claim 11, wherein the
container is a reaction cuvette.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of
priority from prior Japanese Patent Application No. 2003-328603
filed on Sep. 19, 2003, the entire contents of which are
incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to a chemical
analyzer, a method for dispensing and a dilution cup.
BACKGROUND
[0003] Generally, a chemical analyser automatically analyses a
chemical composition included in blood or urine of a human body,
for example. A sample solution and a reagent are dispensed into a
reaction cuvette. The chemical analyser measures, as one of
biochemistry test arrays, concentration/activity of a substance to
be measured or enzyme in the sample solution by measuring amount of
penetration of light in order to obtain a change of color tone
caused by reaction of a mixed solution of the sample solution and
the reagent corresponding to the biochemistry test array.
[0004] Moreover, as other biochemistry test arrays, the chemical
analyser measures concentration of sodium ion or potassium ion or
chlorine ion in a sample solution dispensed into a dilution cup by
measuring a change of electromotive force with an ion sensor about
a mixed solution of the sample solution and a reagent. In this
case, the reagent is used for dilution of the sample solution or
adjustment of pH.
[0005] Major measurement error which is common to many biochemistry
test arrays is caused when the sample solution and the reagent are
dispensed and mixed to be uniformed.
[0006] There are two dispensing methods of the sample solution and
the reagent. One method is a dispensing-first-sample solution
method and another is a dispensing-first-reagent method. Both
methods have the problems described below, respectively.
[0007] In the dispensing-first-sample solution method, the sample
solution is dispensed into a container, and subsequently the
reagent is dispensed into the container to be mixed with the sample
solution.
[0008] The dispensing-first-sample solution method is classified
into two methods, a non-contacting dispensing method and a
contacting dispensing method.
[0009] When amount of the sample solution used for each
biochemistry test array was large, the non-contacting dispensing
method where the sample solution was dispensed into the container
from a sample dispensing probe that was away from the container is
applied.
[0010] However, at the present the amount of the sample solution
used for each biochemistry test array is little. Therefore, as the
contact dispensing method, the sample solution is dispensed into
the container from a sample dispensing probe that is contacting the
container has been applied, since the sample solution that should
be dispensed into the container is adhered to the outside of the
sample dispensing probe or flies in all directions and the sample
solution is not dispensed into an appropriate part of the container
in the non-contacting dispensing method. The contacting dispensing
method is described in Japanese Patent 61-56784 (KOUKOKU) (page 4-5
and FIG. 4-5).
[0011] However, in the contacting dispensing method, the sample
solution dispensed into the container does not spread into the
container depending on the circumstances where stain remains or a
bottom form where the sample dispensing probe contacts the
container influences the spread. As described above, the sample
solution is not dispensed well.
[0012] In order to reduce the problem of the bottom form of the
container, high processing accuracy to make the container is
required. Especially, in the chemical analyser including a
plurality of containers, such as reaction cuvettes, it is difficult
to achieve the high processing accuracy. In order to reduce another
problem of the remain of the stain, a high flushing capacity is
required.
[0013] On the other hand, in the dispensing-first-reagent method,
the reagent is first dispensed into the container, and the sample
solution is dispensed into the container to be mixed with the
reagent. The dispensing-first reagent method is described in
Japanese Patent Disclose (KOKAI) (page 3).
[0014] In the dispensing-first-reagent method, when the sample
dispensing probe directly contacts the reagent, or the sample
dispensing probe does not contact the reagent but a drop located on
a top of the sample dispensing probe contacts a surface of the
reagent, the sample solution is poured from the sample dispensing
probe into the reagent. The sample solution is not adhered to the
outside of the sample dispensing probe or does not fly off, and
therefore, the dispensing-first-reagent method is adapted at the
present when the amount of the sample solution is little.
[0015] The dispensing-first-reagent method needs a more powerful
mixing unit than that in the dispensing-first-sample solution
method, in order to mix the sample solution and the reagent to be
uniformed. However, a speedy measurement or a speedy mixing is
required recently, and it is difficult to achieve the required
speed even with the powerful mixing unit.
[0016] In the chemical analyzer, it is required that the amount of
the sample solution used for each biochemistry test array is
reduced, and the sample solution is dispensed well.
[0017] However, as described above, in the dispensing-first-sample
solution method, the bottom form of the container or the remaining
stain can be major error factor, and in the
dispensing-first-reagent, the powerful mixing unit is required.
SUMMARY
[0018] One object of the present invention is to ameliorate the
above-mentioned problems. According to one aspect of the present
invention, there is provided a method for dispensing a sample
solution and a reagent into a container in a chemical analyser
includes a first step of dispensing a reagent into a container, a
second step of dispensing a sample solution into the container
after the first step, and a third step of dispensing the reagent
into the container after the second step.
[0019] According to another aspect of the present invention, there
is provided a dilution cup includes an inner face where a diameter
of a horizontal section increases on at least one position from a
bottom to a top, an opening portion surrounding an opening, where a
sample solution is dispensed, located on or near the top, a reagent
aperture portion surrounding an aperture where a reagent is
dispensed such that the sample solution and the reagent create an
upswing spiral flow, and a drain aperture portion surrounding a
drain aperture, where a mixed solution of the sample solution and
the reagent is discharged, located on or near the bottom.
[0020] According to another aspect of the present invention, there
is provided a chemical analyser includes a container where a sample
solution and a reagent are mixed, a first mechanism configured to
dispense the reagent into the container, a second mechanism
configured to dispense the sample solution in to the container, and
a controller configured to control the first mechanism to dispense
the reagent in a first step, the second mechanism to dispense the
sample solution in a second step after the first step, and the
first mechanism to dispense the reagent in a third step after the
second step.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] A more complete appreciation of the invention and many of
the attendant advantages thereof will be readily obtained as the
same becomes better understood by reference to the detailed
description when considered in connection with the accompanying
drawings. In the drawings:
[0022] FIG. 1 is a perspective view of a chemical analyzer
according to an embodiment;
[0023] FIG. 2 is a block diagram of an electrolyte measurement
module according to the embodiment;
[0024] FIGS. 3A through 3D are illustrations for explaining an
operation of dispensing solution into a dilution cup according to
the embodiment;
[0025] FIGS. 4A through 4C are illustrations for explaining an
operation of dispensing solution into a dilution cup according to a
modification of the embodiment; and
[0026] FIGS. 5A through 5C are illustrations for explaining an
operation of dispensing solution into a reaction cuvette according
to the embodiment.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0027] Referring to FIGS. 1 through 5, an embodiment of a chemical
analyzer, a method for dispensing and a dilution cup are
explained.
[0028] FIG. 1 shows a perspective view of a chemical analyser of
the embodiment.
[0029] The chemical analyser includes a reagent rack 1 for
supporting a plurality of reagent bottles 7 where a reagent to be
reacted with substance of a sample solution is included, reagent
storages 2 and 3 which can hold the reagent rack 1, a reaction dick
5 for supporting a plurality of reaction cuvettes. The reaction
cuvettes are supported on a circumference of the reaction disk 5.
Further, the chemical analyser includes a disk sampler 6, a first
reagent dispensing arm 8, a second reagent dispensing arm 9, a
sample dispensing arm 10, a photometric measurement unit 13 and an
electrolyte measurement module 18. The disk sampler 6 supports a
plurality of sample solution bottles 17, each of which includes the
sample solution are set. The photometric measurement unit 13
measures a mixed solution of the reagent and the sample solution
which are dispensed into reaction cuvette 4 via the reagent
dispensing arm 8 or 9 and the sample dispensing arm 10,
respectively. The electrolyte measurement module 18 measures a
sample solution dispensed into a dilution cup 19A via the sample
dispensing arm 10.
[0030] The reagent storages 2 and 3, the reaction disk 5 and the
disk sampler 6 are rotatable by a driving unit.
[0031] The reagent for the measurement is pulled out from the
reagent bottle 7 and is dispensed into the reaction cuvette 4 by a
first reagent probe 14 of the first reagent dispensing arm 8 or a
second reagent probe 15 of the second reagent dispensing arm 9.
[0032] The sample solution for the measurement is pulled out from
the sample solution bottle 17 and is dispensed into the reaction
cuvette 4 or the dilution cup 19A by a sample dispensing probe 16
of the sample dispensing arm 10.
[0033] The reaction cuvette 4 where the sample solution and the
reagent are dispensed rotates and moves to such a position that a
mixing unit 11 mixes the sample solution and the reagent.
[0034] The photometric measurement unit 13 irradiates a light to
the reaction cuvette 4 which moves to a photometric measurement
position and measures a change of a light absorption of the mixed
solution. In this measurement, at least one biochemistry test array
other than sodium ion, potassium ion and chlorine ion in the sample
solution is analysed.
[0035] After the analysis of the biochemistry test array, the mixed
solution of the sample solution and the reagent in the reaction
cuvette 4 is evacuated, and the reaction cuvette 4 is washed by a
washing machine 12.
[0036] On the other hand, concentration of the electrolyte of the
sodium ion or the potassium ion or the chlorine ion in a sample
solution dispensed into the dilution cup 19A is measured by the
electrolyte measurement module 18.
[0037] FIG. 2 shows the electrolyte measurement module 18 shown in
FIG. 1. The electrolyte measurement module 18 includes a dilution
cup unit 19, a reagent supply unit 22, a calibration solution
supply unit 23, a reagent suction unit 21, and a ion sensor unit
20. The dilution cup unit 19 is used for mixing the sample solution
and the reagent. The reagent supply unit 22 and the calibration
solution supply unit 23 supply the reagent and the calibration
solution to the dilution cup unit 19, respectively. The reagent
suction unit 21 supplies the mixed solution of the sample solution
and the reagent or the calibration solution to the ion sensor unit
20 which measures the concentration of the electrolyte of the
sodium ion or the potassium ion or the chlorine ion in the mixed
solution of the sample solution and the reagent or the calibration
solution.
[0038] The dilution cup unit 19 includes the dilution cup 19A as
the container for mixing the sample solution and the reagent, a
reagent charge port 19B used for dispensing the reagent into the
dilution cup 19A, and a calibration solution charge nozzle 19C used
for dispensing the calibration solution into the dilution cup
19A.
[0039] The reagent supply unit 22 pulls out the reagent from a
reagent bottle 22B by using a reagent supply pump 22A, and supplies
the reagent into the dilution cup 19 to dilute the sample
solution.
[0040] The calibration solution supply unit 23 pulls out the
calibration solution from a calibration solution bottle 23B by
using a calibration solution supply pump 23A, and supplies the
calibration solution into the dilution cup 19. The calibration
solution is used for washing the dilution cup 19A to remove a
remaining sample solution after the sample solution diluted in the
dilution cup 19A flows into the ion sensor unit 20, and is used for
calibrate an electromotive force of the ion sensor unit 20.
[0041] In the reagent suction unit 21, a reagent suction pump 21A
leads the mixed solution diluted in the dilution cup 19A or the
calibration solution to the ion sensor unit 20 and subsequently the
mixed solution or the calibration solution are evacuated into a
waste solution tank 21B.
[0042] In the ion sensor unit 20, the concentration of the
electrolyte of the sodium ion, the potassium ion and the chlorine
ion by a flow-through type composition electrode including a sodium
ion sensor, a potassium ion sensor, a chlorine ion sensor and a
reference electrode.
[0043] The following is a process for measuring the electrolyte.
The sample solution dispensed into the dilution cup 19A by the
sample dispensing probe 16 shown in FIG. 1 is mixed to the reagent
supplied from the reagent supply unit 22. Thereafter, the mixed
solution is fed to the ion sensor unit 20 by the reagent suction
unit 21 so that the electrolyte is measured.
[0044] The ion sensor unit 20 generates an electronic signal
according to the concentration of a target ion. The electronic
signal is collected by a signal collection unit 24, and is used for
calculation process of the sample solution in a signal processor
25.
[0045] Next, the calibration solution is fed to the ion sensor unit
20 by the calibration solution supply unit 23, and the electrolyte
in the calibration solution is measured. When a result of the
measurement of the calibration solution is compared with a result
of the measurement of the sample solution, the concentration of the
electrolyte is obtained.
[0046] After the measurement, each solution fed to the ion sensor
unit 20 is evacuated by the reagent suction unit 21.
[0047] An operation sequence of the reagent suction pump 21A, the
reagent supply pump 22A, and the calibration solution supply pump
23A, and a process of the signal generated in the ion sensor unit
20 are controlled by a controller according to a program stored in
a memory unit of the chemical analyser in advance.
[0048] FIG. 3A through 3D show illustrations for explaining a
process for dispensing the same reagent twice into the dilution cup
19A.
[0049] FIG. 3A through 3C are sectional views of the dilution cup
19A. At the bottom of the dilution cup, a drain aperture 32 to the
ion sensor unit 20 is located. In an inner face of the dilution cup
19A, a cross section which is substantially perpendicular to a
vertical central axis 19F which is located at a center of the
dilution cup 19A is circular form. A diameter of the circular form
gradually increases from the bottom to a top of the dilution cup
19A. A cross section which is substantially parallel to the
vertical central axis in the inner face is a gradual curved
surface, like a hanging bell.
[0050] The reagent charge port 19B is located at a position
slightly above the bottom of the dilution cup 19A, and extends
horizontally. An reagent charge aperture 19D connects the reagent
charge port 19B to the inner face of the dilution cup 19A is
located on a point on a circumference of the cross section which is
substantially perpendicular to the vertical central axis 19F.
[0051] FIG. 3A shows an illustration for explaining a first step
for dispensing first predetermined amount of the reagent into the
dilution cup 19A.
[0052] For example, when a required amount of the reagent is 575
.mu.l, the first predetermined amount 125 .mu.l which is
approximately 22% of the required amount is dispensed from the
reagent charge port 19B into the dilution cup 19A. The reagent 26A
is dispensed in the first step.
[0053] Speed for dispensing the reagent in the first step is
controlled such that the reagent does not fly off from the dilution
cup 19A by the reagent supply pump 22A.
[0054] FIG. 3B shows an illustration for explaining a second step
for dispensing predetermined amount of the sample solution into the
dilution cup 19A after the first step.
[0055] The sample dispensing arm 10 shown in FIG. 1 rotates such
that the sample dispensing probe 16 is located above the dilution
cup 19A and is located on the vertical central axis 19F. The sample
dispensing probe 16 stops once at the position, and descends
through an opening 31 which is located on the top of the dilution
cup 19A. The sample dispensing probe 16 detects a surface of the
reagent and stops at a depth of about 1 mm under the surface of the
reagent to dispense 25 .mu.l of the sample solution, for example.
In the dilution cup 19A, an intermediate mixed solution of 25 .mu.l
of the sample solution and 125 .mu.l of the reagent exists.
[0056] As described above, since the sample dispensing probe 16
soaks in the reagent 26A dispensed in the first step when the
sample solution is dispensed, as the dispensing-first-reagent
method, the sample solution is not adhered to the outside of the
sample dispensing probe 16 or does not fly off, and therefore, the
dispensing is performed well.
[0057] FIG. 3C shows an illustration for explaining a third step
for dispensing second predetermined amount of the reagent into the
dilution cup 19A.
[0058] After dispensing the sample solution into the dilution cup
19A, the remaining amount 450 .mu.l of the reagent is dispensed
from the reagent charge port 19B by the reagent supply pump 22A to
be uniformly mixed with the intermediate mixed solution 26B.
Finally, the mixed solution 26C of the sample solution and the
reagent exists.
[0059] In the third step, the reagent, 78% of the required reagent,
namely 450 .mu.l, which is more than that of the first step is
dispensed. In addition, the reagent is dispensed from the reagent
charge aperture 19D into the upside down hanging bell formed
dilution cup 19A under the control to create an upswing spiral flow
indicated as an allow in FIG. 3C and FIG. 3D which shows an upper
view of the dilution cup 19A. Thereby, an effective mixing can be
performed.
[0060] Subsequently, the mixed solution 26C is fed to the ion
sensor unit 20 via the drain aperture 32 by the reagent suction
unit 21 so that the electrolyte is measured in the sample
solution.
[0061] An operation of the sample dispensing arm 10 and the sample
dispensing probe 16 is controlled by the controller according to a
program stored in a memory unit of the chemical analyser in advance
so as to work with the operation of each pump described above.
[0062] FIG. 4A through 4C show illustrations for explaining a
process for dispensing the same reagent twice into a commonly used
dilution cup 19A, as a modification. The difference between FIG. 3A
through 3C and FIG. 4A through 4C is a position of a reagent charge
port. In FIG. 3A through 3C, the reagent charge port 19B is located
near the bottom of the dilution cup 19A, however in FIG. 4A through
4C, the reagent charge port 19e is locate above the dilution cup
19A.
[0063] FIG. 4A shows an illustration for explaining a first step
for dispensing first predetermined amount of the reagent. When a
required amount of the reagent is 575 .mu.l, the first
predetermined amount 125 .mu.l which is approximately 22% of the
required amount is dispensed from the reagent charge port 19E into
the dilution cup 19A. The reagent 27A is dispensed in the first
step.
[0064] Speed for dispensing the reagent in the first step is
controlled such that the reagent does not fly off from the dilution
cup 19A by the reagent supply pump 22A.
[0065] FIG. 4B shows an illustration for explaining a second step
for dispensing predetermined amount of the sample solution into the
dilution cup 19A after the first step.
[0066] The sample dispensing arm 10 shown in FIG. 1 rotates such
that the sample dispensing probe 16 is located above the dilution
cup 19A and is located on the vertical central axis 19F. The sample
dispensing probe 16 stops once at the position, and descends
through an opening 31 which is located on the top of the dilution
cup 19A. The sample dispensing probe 16 detects a surface of the
reagent and stops at a depth of about 1 mm under the surface of the
reagent to dispense 25 .mu.l of the sample solution, for example.
In the dilution cup 19A, an intermediate mixed solution of 25 .mu.l
of the sample solution and 125 .mu.l of the reagent exists.
[0067] As described above, since the sample dispensing probe 16
soaks in the reagent 27A dispensed in the first step when the
sample solution is dispensed, as the dispensing-first-reagent
method, the sample solution is not adhered to the outside of the
sample dispensing probe 16 or does not fly off, and therefore, the
dispensing is performed well.
[0068] FIG. 4C shows an illustration for explaining a third step
for dispensing second predetermined amount of the reagent into the
dilution cup 19A.
[0069] After dispensing the sample solution into the dilution cup
19A, the remaining amount 450 .mu.l of the reagent is dispensed
from the reagent charge port 19E by the reagent supply pump unit 22
to be uniformly mixed with the intermediate mixed solution 26B.
Finally, the mixed solution 27C of the sample solution and the
reagent exists.
[0070] In the third step, the reagent, 78% of the required reagent,
namely 450 .mu.l, which is more than that of the first step is
dispensed. In addition, the dispensing of the reagent is controlled
such that the speed of the dispensing is as much as possible within
a range where the reagent does not fly off. Thereby, the reagent
and the sample solution are mixed to be uniformed, and finally the
mixed solution 27C exists.
[0071] Subsequently, the mixed solution 27C is fed to the ion
sensor unit 20 by the reagent suction unit 21 so that the
electrolyte is measured in the sample solution.
[0072] The above mentioned method is effective especially to the
electrolyte measurement where high precision of dispensing of the
reagent and the sample solution is required.
[0073] FIG. 5A through 5C show illustrations for explaining a
process for dispensing the same reagent twice into the reaction
cuvette 4.
[0074] FIG. 5A shows an illustration for explaining a first step
for dispensing first predetermined amount of the reagent into the
reaction cuvette 4.
[0075] The first reagent probe 14 shown in FIG. 1 pulls out a first
reagent corresponding to a biochemistry test array, and the first
reagent dispensing arm 8 rotates such that the first reagent moves
to a position for dispensing. When the lower limit of the amount of
the first reagent which is required for photometric measurement of
the photometric measurement unit 13 is 120 .mu.l, one third of 120
.mu.l, namely 40 .mu.l of the first reagent is dispensed into an
approximate center of the reaction cuvette 4. In this first step,
the reagent 28A exists in the reaction cuvette 4. Thereafter, the
reaction disk 5 rotates such that the reaction cuvette 4 moves to
such a position that the sample solution is dispensed.
[0076] Speed of dispensing of the reagent in the first step is
controlled not to fly off to a side inner face of the reaction
cuvette 4.
[0077] FIG. 5B shows an illustration for explaining a second step
for dispensing predetermined amount of the sample solution into the
reaction cuvette 4 after the first step.
[0078] The sample dispensing arm 10 shown in FIG. 1 rotates such
that the sample dispensing probe 16 is located above a centor of
the reaction cuvette 4. The sample dispensing probe 16 stops once
at the position, descends to the reaction cuvette 4, and detects a
surface of the reagent 28A. The sample dispensing probe 16 stops at
a depth of about 1 mm under the surface of the reagent 28A to
dispense the predetermined amount of the sample solution. In the
reaction cuvette 4, an intermediate mixed solution 28B of the
predetermined amount of the sample solution and the 40 .mu.l of the
reagent exists. Thereafter, the reaction disk 5 rotates such that
the reaction cuvette 4 is located at a position for dispensing the
same reagent as that in the first step once again. The above
operation is controlled by a controller 30.
[0079] As described above, since the sample dispensing probe 16
soaks in the reagent 28A dispensed in the first step when the
sample solution is dispensed, as the dispensing-first-reagent
method, the sample solution is not adhered to the outside of the
sample dispensing probe 16 or does not fly off, and therefore, the
dispensing is performed well.
[0080] FIG. 5C shows an illustration for explaining a third step
for dispensing second predetermined amount of the reagent into the
reaction cuvette 4.
[0081] The first reagent probe 14 that pulls up the reagent fro the
reagent storages 2 and rotates to be located at a second reagent
dispensing position for dispensing the reagent once again. When the
reaction cuvette 4 stops at the second reagent dispensing position,
the second predetermined amount of the reagent, such as more than
two thirds of the required amount, is dispensed into an approximate
centor of the reaction cuvette 4. Thereby, the second dispensed
reagent is mixed with the intermediate mixed solution to be a mixed
solution 28C.
[0082] The reaction disk 5 rotates so that the reaction cuvette 4
moves to a position to be mixed by the mixing unit 11. The mixing
unit 11 further mixes the mixed solution 28C.
[0083] In the third step, the second amount of the reagent which is
more than that in the first step is dispensed, and speed of the
dispensing is as much as possible within a range where the reagent
does not fly off. Thereby, the reagent and the sample solution are
mixed to be uniformed.
[0084] When two kinds of the reagent are required for measurement,
the reaction disk 5 rotates and stops, and the second reagent probe
15 pulls a second reagent corresponding to a biochemistry test
array from the reagent storage 3. Thereafter, the second reagent
dispensing arm 9 rotates, and the second reagent is dispensed into
the reaction cuvette 4 by the second reagent probe 15.
[0085] The photometric measurement unit 13 irradiates the light to
the reaction unit for a predetermined time, and detects the change
of the light passing through the sample solution.
[0086] The above mentioned method is effective especially to the
electrolyte measurement where high precision of dispensing of the
reagent and the sample solution is required.
[0087] The chemical analyser may have a memory which stores
information of relationship between the required total amount of
the reagent and the amount of the reagent dispensed in the first
step. In the memory, the speed of dispensing of the reagent in the
first and third steps may be stored instead of or in addition to
the amount relationship information. The above mentioned separate
dispensing method may be selected by each biochemistry test
array.The speed of dispensing of the reagent in the third step may
be faster than that of the first step, and thereby, more effective
mixing can be performed.
[0088] The present invention may be not limited to the above
embodiments, and various modifications may be made without
departing from the spirit or scope of the general inventive
concept.
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