U.S. patent application number 10/042319 was filed with the patent office on 2002-07-11 for incubator.
This patent application is currently assigned to FUJI PHOTO FILM CO., LTD.. Invention is credited to Komatsu, Akihiro, Sugaya, Fumio.
Application Number | 20020090321 10/042319 |
Document ID | / |
Family ID | 26607496 |
Filed Date | 2002-07-11 |
United States Patent
Application |
20020090321 |
Kind Code |
A1 |
Sugaya, Fumio ; et
al. |
July 11, 2002 |
Incubator
Abstract
An incubator includes a rotating incubator rotor. The incubator
rotor is provided with a plurality of element chambers which are
arranged along the outer periphery of the incubator rotor and each
of which accommodates a dry analysis element spotted with a sample
and incubates the dry analysis element. A light measuring system
has a light measuring head which measures the optical density of
the dry analysis element. The light measuring system is provided
with a correction system which compensates for fluctuation in the
value of the optical density of the dry analysis element in each of
the element chambers as measured by the light measuring head
generated due to fluctuation in the distance between the light
measuring head and the element chamber on the basis of a correction
value which has been stored in the correction system element
chamber by element chamber.
Inventors: |
Sugaya, Fumio;
(Kanagawa-ken, JP) ; Komatsu, Akihiro;
(Kanagawa-ken, JP) |
Correspondence
Address: |
SUGHRUE, MION, ZINN, MACPEAK & SEAS, PLLC
2100 Pennsylvania Avenue, N.W.
Washington
DC
20037-3202
US
|
Assignee: |
FUJI PHOTO FILM CO., LTD.
|
Family ID: |
26607496 |
Appl. No.: |
10/042319 |
Filed: |
January 11, 2002 |
Current U.S.
Class: |
422/64 ; 422/400;
422/63 |
Current CPC
Class: |
G01N 35/025 20130101;
G01N 2035/1032 20130101; G01N 1/38 20130101; G01N 2035/00079
20130101; G01N 2035/106 20130101; G01N 2035/1053 20130101; Y10T
436/111666 20150115; G01N 2035/00376 20130101; G01N 2035/00752
20130101; G01N 2035/00089 20130101; G01N 2035/103 20130101; G01N
2035/00108 20130101; G01N 21/253 20130101; Y10T 436/11 20150115;
G01N 2035/1034 20130101 |
Class at
Publication: |
422/64 ; 422/63;
422/99 |
International
Class: |
G01N 035/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 11, 2001 |
JP |
003179/2001 |
Jan 11, 2001 |
JP |
003181/2001 |
Claims
What is claimed is:
1. An incubator comprising a rotating incubator rotor provided with
a plurality of element chambers which are arranged along the outer
periphery of the incubator rotor and each of which accommodates a
dry analysis element spotted with a sample and incubates the dry
analysis element and a light measuring means having a light
measuring head which measures the optical density of the dry
analysis element, wherein the improvement comprises that the light
measuring means is provided with a correction means which
compensates for fluctuation in the value of the optical density of
the dry analysis element in each of the element chambers as
measured by the light measuring head generated due to fluctuation
in the distance between the light measuring head and the element
chamber on the basis of a correction value which has been stored in
the correction means element chamber by element chamber.
2. An incubator as defined in claim 1 in which the correction means
sets the correction value for each element chamber by inserting a
calibration element whose optical density is known into each of the
element chambers of the incubator rotor, measuring the optical
density of the calibration element with the light measuring head
and determining the correction value for the element chamber on the
basis of the difference between the known optical density of the
calibration element and the measured optical density of the
same.
3. An incubator comprising a rotating incubator rotor provided with
a plurality of element chambers which are arranged along the outer
periphery of the incubator rotor and each of which accommodates a
dry analysis element spotted with a sample and incubates the dry
analysis element, wherein the improvement comprises that the
incubator rotor is provided with a cone-like slant surface which is
formed below the element chambers and tapers downward toward the
axis of rotation of the incubator rotor, a cylindrical rotating
shaft which is connected to the lower end of the slant surface and
the inner space of which opens to the space defined by the
cone-like slant surface so that the dry analysis element in each
element chamber can be discarded outside the incubator through the
space defined by the cone-like slant surface and the inner space of
the cylindrical rotating shaft, and a bearing member which supports
the cylindrical rotating shaft for rotation about the axis of
rotation of the incubator rotor.
4. An incubator as defined in claim 3 in which the slant surface is
at an angle not smaller than 30.degree. to the horizontal.
Description
FIELD OF THE INVENTION
[0001] This invention relates to an incubator which is used in a
biochemical analysis system, in which a sample such as blood or
urine is spotted onto a dry analysis element and, for instance, the
concentration of a specific biochemical component contained in the
sample is detected, to keep the dry analysis element at a constant
temperature in order to measure change of the optical density.
DESCRIPTION OF THE RELATED ART
[0002] Recently, there has been put into practice a colorimetric
dry (dry-to-the touch) analysis element with which the content of a
specific biochemical component or a specific solid component
contained in a sample liquid can be quantitatively analyzed by
simply spotting a droplet of the sample liquid. Since being capable
of analyzing samples easily and quickly, the biochemical analysis
systems using such dry analysis elements are suitably used in
medical institutions, laboratories and the like.
[0003] When quantitatively analyzing the chemical components or the
like contained in a sample liquid using such a colorimetric dry
analysis element, a droplet of the sample liquid is spotted on the
analysis element, and the analysis element is held at a constant
temperature for a predetermined time in an incubator so that a
coloring reaction (pigment forming reaction) occurs, and the
optical density of the color formed by the coloring reaction is
optically measured. That is, measuring light containing a
wavelength which is pre-selected according to the combination of
the component to be analyzed and the reagent contained in the
analysis element is projected onto the analysis element and the
optical density of the analysis element is measured. Then the
concentration of the component to be analyzed is determined on the
basis of the optical density according to a calibration curve
representing the relation between the concentration of the specific
biochemical component and the optical density.
[0004] When the distance between the dry analysis element and the
light measuring head (a head for projecting said measuring light
onto the dry analysis element and receives light from the dry
analysis element bearing thereon the optical density of the dry
analysis element fluctuates, there can be produced measuring errors
since the light measuring head has own optimal measuring distance
due to its light measuring sensitivity properties as will be
described later in conjunction with FIG. 4. In order to accurately
measure the concentration of a specific component in the sample, it
is necessary to detect even a slight coloring reaction and it is
required for the colorimetry to be carried out at a high accuracy.
Accordingly, it is important to keep constant the distance between
the dry analysis element and the light measuring head.
[0005] In Japanese Patent Publication No. 5(1993)-72976, the
optical components of the light measuring head are positioned where
the output of the light measuring head is maximized, so that the
influence of variation of the distance on the light measuring
sensitivity is minimized.
[0006] In U.S. Pat. No. 5,037,613, there is disclosed a structure
in which the lower surface of the outer periphery of the incubator
rotor, which is rotated with dry analysis elements spotted with the
samples accommodated therein, is supported by a sliding support so
that the rotational displacement of the incubator rotor is
suppressed and the distance between the light measuring head and
each of the dry analysis elements arranged along the outer
periphery of the incubator rotor is held constant.
[0007] However, the approach disclosed in the aforesaid Japanese
patent publication is disadvantageous in that though fluctuation of
the distance can be held in an acceptable range where the influence
of variation of the distance on the light measuring sensitivity can
be suppressed by the arrangement of the optical components so long
as the diameter of the incubator rotor is small and the rotational
displacement of the incubator rotor is small, fluctuation of the
distance becomes too large for the optical components to suppress
the influence of variation of the distance on the light measuring
sensitivity in an acceptable range when the number of the dry
analysis elements to be accommodated in the incubator increases and
the diameter of the incubator rotor increases. An attempt to limit
the rotational displacement of a large incubator rotor increases
requirement on processing accuracy and fabricating accuracy of the
components of the incubator rotor, thereby adding to the
manufacturing cost of the incubator.
[0008] The approach disclosed in the United states patent is
disadvantageous in that as the sliding support wears, the
rotational displacement of the incubator rotor increases and the
incubator rotor drive mechanism can become unstable due to
nonuniform load and wear of the sliding support will produce
dust.
[0009] Displacement in height of the incubator rotor relative to
the measuring head during rotation of the incubator rotor is
generated by strain generated when forming the rotor and/or strain
generated when mounting the rotor on the rotating shaft.
Accordingly, the distance between the measuring head and each of
the element chambers arranged along the outer periphery of the
incubator rotor when the element chamber is brought to a
predetermined position, e.g., a light measuring position where the
optical density of the dry analysis element is to be measured, is
constant for each element chamber but differs from chamber to
chamber. As the difference in the distance between the measuring
head and the element chambers increases, variation in the measured
value for a given optical density becomes larger.
[0010] As disclosed, for instance, in Japanese Unexamined Patent
Publication No. 11(1999)-237386, there has been known an incubator
provided at its center with an element discarding hole through
which dry analysis elements after measurement are discarded by
pushing the dry analysis elements further inward by the element
transfer member which pushes the dry analysis elements into the
element chambers of the incubator. This structure is advantageous
in that the dry analysis elements can be easily discarded with the
transfer mechanism of a simple structure.
[0011] However, as the number of the dry analysis elements to be
accommodated in the incubator increases and the diameter of the
incubator rotor increases, the diameter of the discarding hole must
be large in order to discard the dry analysis elements in all the
element chambers by a limited stroke of the element transfer
member. When the diameter of the discarding hole is enlarged and
the diameter of the rotating shaft of the incubator rotor is
increased, the diameter of the bearing member for supporting the
rotating shaft must be large, which adds to the manufacturing cost
of the bearing member. Especially when the bearing member must
support the rotating shaft of the incubator rotor so as to suppress
the rotational displacement of the incubator rotor in the
acceptable range as described above, the manufacturing cost of the
bearing member is further increased.
[0012] On the other hand, when the diameter of the element
discarding hole is reduced, the distance over which the dry
analysis elements are conveyed to be discarded becomes longer,
which adds to the length and stroke of the element transfer member
and increases the overall size and weight of the apparatus.
SUMMARY OF THE INVENTION
[0013] In view of the foregoing observations and description, the
primary object of the present invention is to provide an incubator
which can accurately measure the optical density of the dry
analysis element in all the element chambers of the incubator
without using a sliding support and can be manufactured at low cost
even if it is provided with a large number of element chambers and
is large in size.
[0014] Another object of the present invention is to provide an
incubator which is precise in rotation and small in weight and in
which the dry analysis elements can be easily discarded after
measurement.
[0015] The first object of the present invention can be
accomplished by an incubator comprising a rotating incubator rotor
provided with a plurality of element chambers which are arranged
along the outer periphery of the incubator rotor and each of which
accommodates a dry analysis element spotted with a sample and
incubates the dry analysis element and a light measuring means
having a light measuring head which measures the optical density of
the dry analysis element, wherein the improvement comprises
that
[0016] the light measuring means is provided with a correction
means which compensates for fluctuation in the value of the optical
density of the dry analysis element in each of the element chambers
as measured by the light measuring head generated due to
fluctuation in the distance between the light measuring head and
the element chamber on the basis of a correction value which has
been stored in the correction means element chamber by element
chamber.
[0017] It is preferred that the correction means sets the
correction value for each element chamber by inserting a
calibration element whose optical density is known into each of the
element chambers of the incubator rotor, measuring the optical
density of the calibration element with the light measuring head
and determining the correction value for the element chamber on the
basis of the difference between the known optical density of the
calibration element and the measured optical density of the
same.
[0018] In the incubator of this invention, since the measured value
of the optical density of the dry analysis element in each element
chamber is corrected on the basis of a correction value which is
set according to the position of the element chamber, i.e., the
distance between the light measuring head and the element chamber
in which the dry analysis element is accommodated, the optical
density can be accurately measured for each element chamber even if
the distance between the light measuring head and each of the
element chambers of the incubator fluctuates chamber to chamber.
Accordingly, the incubator rotor need not be so precisely
manufactured and the sliding support becomes unnecessary, whereby
the incubator can be easily manufactured at low cost and the
durability of the incubator is increased.
[0019] When the correction means sets the correction value for each
element chamber by inserting a calibration element whose optical
density is known into each of the element chambers of the incubator
rotor, measuring the optical density of the calibration element
with the light measuring head and determining the correction value
for the element chamber on the basis of the difference between the
known optical density of the calibration element and the measured
optical density of the same, setting of the correction value is
facilitated.
[0020] That is, though the incubator rotors rotate in different
ways according to the processing accuracy and the like and the
distance between the light measuring head and each of the element
chambers in the measuring position to which the element chambers
are brought in sequence as the incubator rotor rotates differs
element chamber to element chamber, the optical density can be
accurately measured for each element chamber irrespective of
fluctuation in distance between the light measuring head and the
element chamber by correcting the measured value for each element
chamber on the basis of a correction value determined for each
element chamber according to the real distance between the light
measuring head and the element chamber. The correction value for
each element chamber can be easily set by reading the measurement
for a calibration element whose optical density is known and
determining the correction value on the basis of the difference
between the known optical density and the measured value.
[0021] The second object of the present invention can be
accomplished by an incubator comprising a rotating incubator rotor
provided with a plurality of element chambers which are arranged
along the outer periphery of the incubator rotor and each of which
accommodates a dry analysis element spotted with a sample and
incubates the dry analysis element, wherein the improvement
comprises that
[0022] the incubator rotor is provided with a cone-like slant
surface which is formed below the element chambers and tapers
downward toward the axis of rotation of the incubator rotor, a
cylindrical rotating shaft which is connected to the lower end of
the slant surface and the inner space of which opens to the space
defined by the cone-like slant surface so that the dry analysis
element in each element chamber can be discarded outside the
incubator through the space defined by the cone-like slant surface
and the inner space of the cylindrical rotating shaft and a bearing
member which supports the cylindrical rotating shaft for rotation
about the axis of rotation of the incubator rotor.
[0023] It is preferred that the slant surface be at an angle not
smaller than 30.degree. to the horizontal so that the dry analysis
element is surely slid on the slant surface toward the cylindrical
rotating shaft.
[0024] In the incubator of this arrangement, the rotating shaft
need not be large in diameter even if the number of the dry
analysis elements to be accommodated in the incubator increases and
the diameter of the incubator rotor increases, and accordingly, the
bearing member may be small in diameter, whereby the incubator can
be manufactured at low cost. Further, since the dry analysis
elements after measurement can be discarded by pushing the dry
analysis elements only to the slant surface, the stroke of the
element transfer member need not be enlarged even if the number of
the dry analysis elements to be accommodated in the incubator
increases and the diameter of the incubator rotor increases,
whereby the incubator can be small in size and weight.
[0025] Further by virtue of the member defining the cone-like slant
surface, rigidity of the incubator rotor is increased and the
incubator rotor can be rigid enough though it is small in weight,
whereby wobbling of the incubator rotor can be suppressed without
use of a sliding support and the measuring accuracy can be
enhanced.
[0026] The incubator can be employed to incubate various types of
dry analysis element without limited to the colorimetric dry
analysis element. For example, the incubator can be employed to
incubate electrolytic dry analysis elements for measuring the
activity of a specific ion contained in a sample liquid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a perspective view showing a biochemical analysis
system provided with an incubator in accordance with an embodiment
of the present invention,
[0028] FIG. 2 is a schematic cross-sectional view showing the
incubator with the cover removed,
[0029] FIG. 3 is a block diagram showing the measuring mean,
[0030] FIG. 4 is a view for illustrating change of the sensitivity
of the light measuring head with the distance between the element
chamber and the light measuring head,
[0031] FIG. 5 is a view showing correction value properties,
and
[0032] FIG. 6 is a cross-sectional view showing an incubator in
accordance with another embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0033] In FIG. 1, a biochemical analysis system 1 comprises a
system body 17 and a circular sample tray 2 is provided on one side
of the front portion of the system body 17. A circular incubator 3
is provided on the other side of the front portion of the system
body 17, and a spotting station (not shown) is provided between the
sample tray 2 and the incubator 3. Further a spotting nozzle unit 5
is provided on an upper portion of the systembody 17 to be movable
right and left. A dry analysis element 11 held in a sample
cartridge 7 is moved to the spotting station and spotted with a
sample. Then the dry analysis element 11 spotted with the sample is
transferred to the incubator 3. A blood filtering unit 6 for
separating blood plasma from blood is provided beside the sample
tray 2.
[0034] The incubator 3 comprises an incubator rotor 30 and a
measuring means 4. The incubator rotor 30 comprises lower and upper
disc members 31 and 32, and a plurality of element chambers 33 in
which the dry analysis elements 11 are inserted are formed between
the lower and upper disc members 31 and 32 arranged along the
circumference of the disc members 31 and 32 at regular
intervals.
[0035] A rotating shaft 36 extends downward at the center of the
lower disc member 31 and the rotating shaft 36 is supported for
rotation by a bearing member 37 so that the lower disc member 31 is
rotated horizontally about the rotating shaft 36. A sprocket 36s is
fixed to the lower end portion of the rotating shaft 36 and in mesh
with a drive gear 38a fixed to the output shaft of a drive motor 38
so that the incubator rotor 30 is rotated in the regular direction
and the reverse direction by the drive motor 38.
[0036] Sliding holes 32a are formed in the upper disc member 32 to
be opposed to the element chambers 33. A pressing member 34 is
disposed above each element chamber 33 with its upper portion
slidably received in the sliding hole 32a. The lower surface of the
pressing member 34 presses downward the dry analysis element 11
inserted into the element chamber 33 and tightly closes the
spotting hole of the dry analysis element 11 (through which the
sample is spotted onto the element 11) to prevent evaporation
thereof. The outer edge of the lower portion of the pressing member
34 is tapered so that the dry analysis element 11 inserted into the
element chamber 33 is brought into abutment against the tapered
surface to push upward the pressing member 34.
[0037] A heater 35 is provided in the upper disc member 32 to heat
the dry analysis elements 11 in the element chambers 33. By
controlling the heater 36, the dry analysis elements can be held at
a desired constant temperature (incubated).
[0038] A light measuring window 31a is formed in the bottom of the
lower disc member 31 opposed to each of the element chambers 33. A
light measuring head 41 is positioned below the light measuring
window 31a of the element chamber 33 stopped in a light measuring
position shown in FIG. 2. Though not shown, the incubator rotor 30
is covered with a cover in order to cut influence of the ambient
temperature to the dry analysis elements 11 and to prevent external
light from impinging upon the light measuring head 41.
[0039] The incubator rotor 30 is rotated back and forth so that the
element chambers 33 are brought to the light measuring position in
sequence and returned to the initial position after measurement of
the optical density of each dry analysis element 11 due to the
coloring reaction.
[0040] When the optical density is measured, the light measuring
head 41 projects measuring light containing a wavelength which is
pre-selected according to the combination of the component to be
analyzed and the reagent contained in the dry analysis element 11
onto the dry analysis element 11 through the light measuring window
31a and measures the optical density of the dry analysis element
11. The light measuring head 41 is mounted on the incubator body
(not shown). As the incubator rotor 30 is rotated by the drive
motor 30, the distance d between the element chamber in the light
measuring position and the light measuring head 41 periodically
changes since the height of the incubator rotor 30 in the light
measuring position varies according to the angle at which the
incubator rotor 30 is mounted on the rotating shaft 36.
[0041] As shown in FIG. 3, the optical density of the dry analysis
element 11 as measured by the light measuring head 41 is sent to an
operating section 42 and is corrected by a correction means 43 on
the basis of a correction value which has been stored for the
position of each element chamber 33 (for the distance of each
element chamber 33 from the light measuring head 41 when the
element chamber 33 is in the light measuring position). The
correction means 43 is provided with a correcting section 44. The
correcting section 44 receives a signal from a position detecting
section 45 which represents the position of the element chamber 33
which is stopped above the light measuring head 41 (in the light
measuring position) and reads out a correction value corresponding
to the element chamber 33 stopped above the light measuring head 41
from a memory 46. The operating section 42 corrects the optical
density of the dry analysis element 11 in the element chamber 33 in
the light measuring position on the basis of the correction value,
thereby obtaining a true optical density of the dry analysis
element 11 free from influence of fluctuation in distance.
[0042] The position detecting section 45 detects the rotational
phase of the incubator rotor 30 by way of rotation of the motor 38
(e.g., by the use of a rotary encoder) and detects the element
chamber 33 which is stopped in the light measuring position. Though
not shown, the control section of the biochemical analysis system 1
which controls the overall operation of the system 1 is provided
with a bar code reader and bar codes representing information on
the item to be analyzed of the dry analysis element 11 to be
inserted into each element chamber 33 is read by the bar code
reader. The information on the item to be analyzed of the dry
analysis element 11 to be inserted is stored together with the
element chamber 33 in which the dry analysis element 11 is
inserted.
[0043] The correction means 43 is further provided with a
calibrating section 47 inserts a calibration element whose optical
density is known into each of the element chambers 33 of the
incubator rotor 30, receives the optical density of the calibration
element as measured by the light measuring head 41 from the
operating section 42 and writes the correction value for the
element chamber determined on the basis of the difference between
the known optical density of the calibration element and the
measured optical density of the same in the memory 46.
[0044] The operating section 42 outputs corrected optical density
to a concentration calculating section 48 and the concentration
calculating section 48 determines the concentration of the
component to be analyzed on the basis of the corrected optical
density according to a calibration curve 49 and outputs the
concentration of the component thus determined as a measured
concentration.
[0045] Basic properties of the correction will be described with
reference to FIGS. 4 and 5, hereinbelow. The sensitivity of the
light measuring head 41 changes with change in distance d to the
dry analysis element 11 generally as shown in FIG. 4. When a
calibration element of a highly reflective ceramic whose optical
density is known is measured, the output of the light measuring
head 41 is maximized (Vo) at a point D at which the distance d is
optimal, and is reduced as the distance d is reduced or increased.
For example, at point a, where the distance d is smaller than at
the point D, the output of the light measuring head 41 is reduced
to V1 and at point b, where the distance d is smaller than at the
point D, the output of the light measuring head 41 is reduced to
V2. This properties changes in proportion with change of the
optical density of the dry analysis element 11. On the basis of
this fact, the correction value is set.
[0046] FIG. 5 shows the relation between the output of the light
measuring head 41 before correction and the corrected optical
density. In FIG. 5, Ko is a line of correlation between the
measured optical density Vo (the output of the light measuring head
41) as measured at the point D and the true optical density Eo. The
correction value is set according to, for instance, correlation
lines Ka and Kb (which are for the points a and b, respectively)
which are obtained by moving parallel the line Ko so that the
outputs V1 and V2 of the light measuring head 41 as measured at the
points a and b correspond to the true optical density Eo.
[0047] That is, an output Va of the light measuring head 41 as
measured at a distance from an element chamber 33 equal to that of
the point a is converted according to the correlation line Ka to an
optical density Ea which is higher than uncorrected optical density
Ea' converted according to the correlation line Ko. Similarly, an
output Vb of the light measuring head 41 as measured at a distance
from an element chamber 33 equal to that of the point b is
converted according to the correlation line Kb to an optical
density Eb which is higher than uncorrected optical density Eb'
converted according to the correlation line Ko.
[0048] The distance by which the correlation line Ko is moved to
obtain the correlation line Ka or Kb is a function of the distance
d between the light measuring head 41 and the element chamber 33
which can be represented by the rotating angle of the incubator
rotor 30. Accordingly, by measuring a calibration element whose
optical density is known and determining the deviation of the
measured optical density from the known optical density as a
distance from the optimal distance where the sensitivity of the
light measuring head 41 is maximized, the influence on the measured
value of fluctuation of the distance between the light measuring
head 41 and the element chamber 33 can be compensated for.
[0049] For example, incubator rotors 30 have different rotational
displacement properties due to, for instance, processing accuracy
and the distance to the light measuring head 41 differs from
element chamber to element chamber (in the light measuring
position). A calibration element whose optical density is known is
inserted into each of the element chambers 33 and the optical
density of the calibration element in each element chamber 33 is
measured while rotating the incubator rotor 30 to bring the element
chambers 33 to the light measuring position in sequence. The
correction value is determined for each element chamber 33 on the
basis of the difference between the measured optical density and
the known optical density, and the correction values for the
respective element chambers 33 are stored together with the angular
positions of the incubator rotor 30, i.e., the positions of the
respective element chambers 33. Then the output of the light
measuring head 41 is corrected (the measured optical density is
corrected) on the basis of the correction value specific to the
element chamber 33.
[0050] In FIG. 1, the sample tray 2 comprises a turntable 21 which
is rotated in opposite directions. Five sample cartridges 7 are
mounted on the turntable 21 in an arcuate line. The sample
cartridges 7 are removable separately from each other. Each sample
cartridge 7 comprises a sample holding portion 71 which holds a
sample container 10 (a blood-collecting tube) holding therein a
sample, and an analysis element holding portion 72 which holds a
stack of virgin dry analysis elements 11 of different types.
[0051] Consumables are held on the other part of the upper surface
of the turntable 21 along the outer periphery. For example, a
number of nozzle tips 21, a mixing cup 13 (a molded product
provided with a plurality of cup-like recesses), a diluent
container 14 and a container 15 for other purposes are held on the
turntable 21 along the outer periphery thereof. The consumables may
be set on the sample tray 2 in the form of cartridges like the
sample cartridge 7.
[0052] The turntable 21 of the sample tray 2 is rotated in the
regular direction or the reverse direction by a drive mechanism
(not shown) to positions where the spotting nozzle unit 5 operates.
By controlling the angular position of the turntable and the
position of the spotting nozzle unit 5, predetermined operations
required to spotting the sample on the analysis element such as
mounting a nozzle tip 12, sucking a sample, diluent or the
reference liquid, and mixing the sample and the diluent are carried
out.
[0053] An element transfer means (not shown) which transfers the
dry analysis element 11 is provided at the central portion of the
sample tray 2. The element transfer means comprises an element
transfer member (an insertion lever) which is slid back and forth
in a radial direction of the sample tray 2 by a drive mechanism
(not shown). The element transfer means causes the element transfer
member to push a dry analysis element 11 out of a sample cartridge
7 into the spotting station, to push the element 11 spotted with
the sample into the incubator 3, and to further push the element 11
toward the center of the incubator 3 after measurement to discard
the element 11. The element transfer means controls the drive
mechanism for the turntable 21 to bring the sample cartridges 7 to
the spotting station in sequence. When plasma of the sample is to
be filtered, a holder 16 with a filter is mounted on the sample
container 10 set in the sample cartridge 7 as shown in FIG. 1.
[0054] The dry analysis element 11 generally comprises a square
mount and a reagent layer provided in the mount. A spotting hole is
formed on the surface of the mount and the sample is spotted in the
spotting hole. The dry analysis element 11 is provided with bar
codes (not shown) representing information on the item to be
analyzed.
[0055] The spotting station (not shown) is for spotting a sample
such as plasma, whole blood, serum, urine or the like on the dry
analysis element 11. Though not shown, a bar code reader for
reading the bar code on the element 11 is provided on the upstream
side of the spotting station. The bar code reader is for
identifying the item of measurement and controlling the subsequent
spotting and measurement, and for detecting the position of the
element 11 (whether the element 11 is upside down or in a wrong
direction).
[0056] The spotting nozzle unit 5 comprises a horizontal movement
block 51 which is movable in a horizontal direction and a pair of
vertical movement blocks 52 which are movable up and down on the
horizontal movement block 51. A spotting nozzle 53 is fixed on each
of the vertical movement block 52. The horizontal movement block 51
and the vertical movement blocks 52 are moved in the respective
direction by drive means (not shown). The spotting nozzles 53 are
integrally moved right and left and are moved up and down
independently of each other. For example, one of the spotting
nozzles 53 is for spotting the sample, and the other is for
spotting the diluent.
[0057] The spotting nozzle 53 is in the form of a rod provided with
an air passage extending in the axial direction and a pipette-like
nozzle tip 12 is fitted on the lower end portion thereof. The
spotting nozzles 53 are connected to air tubes respectively
connected to syringe pumps (not shown), and a suction force and a
discharge force are selectively supplied to the spotting nozzles
53. After measurement, the used nozzle tips 12 are removed from the
spotting nozzles 53 and discarded.
[0058] The blood filtering unit 6 is inserted into the sample
container 10 held in the sample tray 2 and sucks plasma through the
holder 16 with a glass fiber filter which is mounted on the upper
end of the sample container 10, thereby separating plasma from the
blood and holding the separated plasma in a cup formed on the top
of the holder 16. The blood filtering unit 6 comprises a sucking
mechanism 61 which supplies suction force, and a suction pad 62
which is connected to a suction pump (not shown) and attracts the
holder 16 under a suction force is provided on the lower end of the
sucking mechanism 61. The sucking mechanism 61 is mounted on a
support post 63 to be moved up and down by a drive mechanism (not
shown). When the plasma is separated from the blood, the sucking
mechanism 61 is moved downward to be brought into a close contact
with the holder 16. In this state, the suction pump is operated to
suck the whole blood in the sample container 10, whereby the plasma
separated from the blood is introduced into the cup formed on the
top of the holder 16. Thereafter, the sucking mechanism 61 is
returned to the initial position.
[0059] In FIG. 1, a control panel 18 is provided above the
incubator 3. The sample tray 2 and the spotting nozzle unit 5 are
covered with a transparent protective lid 19 which is openable.
[0060] Operation of the biochemical analysis system 1 will be
described, hereinbelow. A sample container 10 and one or more
unsealed dry analysis elements 11 suitable for the item of
measurement are set in a sample cartridge 7 outside the system body
17. Then the lid 19 is opened and the sample cartridge 7 is set in
the sample tray 2. When a plurality of samples are to be measured,
a plurality of suitable sample cartridges 7 are set in the sample
tray 2. Further consumables such as the nozzle tips 12, the mixing
cups 13, the diluent containers 14 and the like are set in the
sample tray 2.
[0061] Then analysis is started. In case of emergency, analysis is
interrupted and the sample cartridge 7 to be analyzed urgently is
set in a vacant space or in place of another sample cartridge.
[0062] Blood plasma is first separated from the whole blood in the
sample container 10 by the blood filtering unit 6. Then the sample
tray 2 is rotated to bring the sample cartridge 7 containing
therein a sample to be analyzed to the spotting station. Then one
of the dry analysis elements 11 in the sample cartridge 7 is
transferred to the spotting station by the element transfer member
91 of the transfer means 9. On the way to the spotting station, the
bar code on the element 11 is read by the bar code reader and the
item of analysis and the like are detected.
[0063] When the item of analysis represented by the bar code is
colorimetry, the sample tray 2 is rotated to bring a nozzle tip 12
below the spotting nozzle 53 and the nozzle tip 12 is mounted on
the spotting nozzle 53. Then the sample container 10 is moved and
the spotting nozzle 53 is moved downward to dip the nozzle tip 12
into the sample and to cause the nozzle tip 12 to suck the sample.
Thereafter the spotting nozzle 53 is moved to the spotting station
and spots the sample onto the dry analysis element 11 at the
spotting station.
[0064] Then the dry analysis element 11 spotted with the sample is
inserted into an element chamber 33 of the incubator 3. In response
to insertion of the dry analysis element 11 into the element
chamber 33, the pressing member 34 presses downward the dry
analysis element 11, whereby evaporation of the sample is prevented
and the dry analysis element 11 is heated to a predetermined
temperature. After insertion of the dry analysis element 11 into
the element chamber 33, the incubator rotor 30 is rotated to bring
the element chambers 33 to the measuring position in sequence where
the dry analysis element 11 in the chamber 33 is opposed to the
light measuring head 41. After a predetermined time, change of the
optical density of the element 11 due to reaction of the sample
with the reagent is measured by the light measuring head 41. After
the measurement, the dry analysis element 11 is pushed toward the
center by the element transfer member 91 to be discarded. The
result of the measurement is output and the used nozzle tip 12 is
removed from the spotting nozzle 53. Then processing is ended.
[0065] When the sample is to be diluted, e.g., when the blood is
too thick to carry out accurate measurement, the sample tray 2 is
moved to bring the nozzle tip 12 holding the sample to a mixing cup
13. Then the spotting nozzle 53 discharges the sample held by the
nozzle tip 12 into the mixing cup 13. Then the used nozzle tip 12
is removed from the spotting nozzle 53, and a new nozzle tip 12 is
mounted on the spotting nozzle 53. The spotting nozzle 53 causes
the nozzle tip 12 to suck the diluent from the diluent container 14
and to discharge the diluent into the mixing cup 13. There after
the spotting nozzle 53 dips the nozzle tip 12 into the mixing cup
and causes the nozzle tip 12 to repeat suck and discharge, thereby
stirring the mixture in the mixing cup 13. Then the spotting nozzle
53 causes the nozzle tip 12 to suck the diluted sample and moves
the nozzle tip 12 to the spotting station. At the spotting station,
the spotting nozzle 53 causes the nozzle tip 12 to spot the diluted
sample onto the dry analysis element 11. Then the aforesaid, light
measuring step, element discarding step and result outputting step
follow.
[0066] In the incubator of this embodiment, since the measured
optical density output by the light measuring head 41 is corrected
according to the position of the element chamber 33, that is, the
distance to the light measuring head 41 of the element chamber 33,
fluctuation of the distance between the light measuring head 41 and
the element chamber 33 due to errors and/or strain in processing
and/or assembly can be compensated for, and accordingly, the
optical density of the dry analysis element 11 can be accurately
measured without adding to the manufacturing cost of the
incubator.
[0067] FIG. 6 is a cross-sectional view showing an incubator in
accordance with another embodiment of the present invention. The
elements analogous to those shown in FIGS. 1 and 2 are given the
same reference numerals and will not be described in detail
here.
[0068] The incubator 103 of this embodiment comprises an incubator
rotor 30 and a measuring means 4. The incubator rotor 30 comprises
lower and upper disc members 31 and 32, and a plurality of element
chambers 33 in which the dry analysis elements 11 are inserted are
formed between the lower and upper disc members 31 and 32 arranged
along the circumference of the disc members 31 and 32 at regular
intervals. The bottom surface of each element chamber 33 is flush
with the upper surface of the spotting station and the dry analysis
element 11 can be inserted into the chamber 33 from the spotting
station by simply pushing the element 11.
[0069] Sliding holes 32a are formed in the upper disc member 32 to
be opposed to the element chambers 33. A pressing member 34 is
disposed above each element chamber 33 with its upper portion
slidably received in the sliding hole 32a. The lower surface of the
pressing member 34 presses downward the dry analysis element 11
inserted into the element chamber 33 and tightly closes the
spotting hole of the dry analysis element 11 (through which the
sample is spotted onto the element 11) to prevent evaporation
thereof. The outer edge of the lower portion of the pressing member
34 is tapered so that the dry analysis element 11 inserted into the
element chamber 33 is brought into abutment against the tapered
surface to push upward the pressing member 34.
[0070] A heater 35 is provided in the upper disc member 32 to heat
the dry analysis elements 11 in the element chambers 33. By
controlling the heater 36, the dry analysis elements can be held at
a desired constant temperature (incubated).
[0071] A light measuring window 31a is formed in the bottom of the
lower disc member 31 opposed to each of the element chambers 33. A
light measuring head 41 is positioned below the light measuring
window 31a of the element chamber 33 stopped in a light measuring
position shown in FIG. 2. A circular opening 108a which opens in
the element discarding hole to be described later is formed in the
central portion of the lower disc member 31. A lower member 136 is
provided below the circular opening 108a.
[0072] The lower member 136 is provided with a cone-like slant
surface 136a which tapers downward toward the axis of rotation of
the incubator rotor 30, a cylindrical rotating shaft 136b which is
connected to the lower end of the slant surface 136a and the inner
space of which opens to the space defined by the cone-like slant
surface 136a so that the dry analysis element in each element
chamber can be discarded outside the incubator 3 through the space
defined by the cone-like slant surface 136a and the inner space of
the cylindrical rotating shaft 136b.
[0073] A bearing member 137 horizontally supports the cylindrical
rotating shaft 136b for rotation about the axis of rotation of the
incubator rotor 30. When the slant surface 136a is at an angle not
smaller than 30.degree. to the horizontal, the dry analysis element
11 is surely slid on the slant surface 136a toward the cylindrical
rotating shaft 136b.
[0074] In the incubator of this arrangement, the rotating shaft
136b need not be large in diameter even if the number of the dry
analysis elements 11 to be accommodated in the incubator 3
increases and the diameter of the incubator rotor 30 increases, and
accordingly, the bearing member 137 maybe small in diameter, where
by the incubator 3 can be manufactured at low cost. Further, since
the dry analysis elements 11 after measurement can be discarded by
pushing the dry analysis elements 11 only to the slant surface
136a, the stroke of the element transfer member need not be
enlarged even if the number of the dry analysis elements 11 to be
accommodated in the incubator 3 increases and the diameter of the
incubator rotor 30 increases, whereby the incubator 3 can be small
in size and weight.
[0075] Further by virtue of the lower member 136 defining the
cone-like slant surface 136a, rigidity of the incubator rotor 30 is
increased and the incubator rotor 30 can be rigid enough though it
is small in weight, whereby wobbling of the incubator rotor 30 can
be suppressed without use of a sliding support and the measuring
accuracy can be enhanced.
* * * * *