Note: Descriptions are shown in the official language in which they were submitted.
CA 02501895 1997-06-30
AUTOMATIC CHEMISTRY ANALYZER
FIELD OF THE INVENTION
This invention generally relates to the field of automated clinical
chemical analyzers, and specifically to compact automated chemical analyzers
using a nephelometer.
BACKGROUND OF THE INVENTION
A number of different automated clinical chemical analyzers are
known in the art. Such analyzers range from simple, largely manually-operated
instruments to highly complex, nearly fully automated instruments. Each
analyzer
has its own particular performance characteristics related to the number of
different tests ('menu'1 that the analyzer can perform and the number of
samples
that the analyzer can process in a given period of time ('throughput"1.
As sophisticated and efficient as are many of today's automated
analyzers, several problems continue to exist. First and foremost is
throughput
capacity. Every second which can be saved in the analysis time of a single
sample means millions of dollars in savings of precious medical resources.
Therefore, there is continuous pressure on analyzer manufacturers to increase
throughput. The automated analyzers of the prior art are quite fast, but not
fast
enough.
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An additional problem in the prior art is cost of operation. Most
automated analyzers of the prior art use relatively large reaction containers
("cuvettes") which require an excessive amount of expensive reagent materials.
Still another problem in the prior art is the amount of time that an
operator must spend inputting data and instructions into the analyzer. This
diminishes throughput and causes excessive manpower expenses.
Still another problem related to throughput is the necessity of prior
art analyzing machines which use a nephelometric analyzer to periodically shut
down operations to calibrate the nephelometer.
Fnally, there is a problem regarding throughput vacuum drain
systems used in automatic analyzers of the prior art. Such vacuum drain
systems
are generally wasteful with respect to the use of vacuum. Such waste results
in
2 0 the use of excessively large vacuum usage and may decrease throughput of
the
analyzer.
Accordingly, there is a need for an automated clinical chemical
analyzer which has greater throughput than prior art analyzer modules,
requires
less manpower to operate, is more reliable and is more efficient.
SUMMARY OF THE ~V~NTION
The invention satisfies these needs. The invention is a device for
determining at feast ane parameter of a liquid sample comprising:
(a) a body;
(b) a motorized sample station disposed within the body, the
sample station being sized and dimensioned to retain a plurality of sample
containers and having a sample extraction site, the sample station being
movable
within the body such that, when the sample station retains a plurality of
sample
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containers, individual sample containers can alternatively be moved to and
away
from the sample extraction site;
(c) a motorized reagent station disposed within the body, the
reagent station being sized and dimensioned to retain a plurality of reagent
containers and having a reagent extraction site, the reagent station being
movable
within the body such that, when the reagent station retains a plurality of
reagent
containers, individual reagent containers can alternatively be moved to and
away
from the reagent extraction site;
(d) a motorized random access analyzing station disposed within
the body, the random access analyzing station being sized and dimensioned to
1 S retain a plurality of cuvettes and having a cuvette mixing site, a cuvette
washing
site, a random access analyzing station analyzing site and an analyzer
disposed
proximate to the random access analyzing station analyzing site for
determining
at least one parameter of a sample disposed within the cuvettes, the random
access analyzing station being movable within the body such that, when the
random access analyzing station retains a plurality of cuvettes, individual
cuvettes
can alternatively be moved to and away from (1 ) the cuvette mixing site, (2)
the
cuvette washing site and (3) the random access analyzing station analyzing
site;
(e) a sample probe arm assembly attached to the body, the
sample probe arm assembly including (1 ) a sample probe arm, (2) a hollow
sample
probe having an internal chamber, an open lower end and an open upper end and
(3) an elongate rotatable sample stirring rod having a lower end and an upper
end,
the Lower end of the sample stirring rod including a sample stirring rod
paddle
attached thereto, the sample probe and the sample stirring rod being disposed
generally vertically in close proximity to one ariother, the sample probe
being
vertically movable befween a lower sample probe position and an upper sample
probe position, the sample stirring cod being movable of the sample probe
between a lower sample stirring rod position and an upper sample stirring rod
position, the sample probe and sample stirring rod being disposed within the
sample probe arm assembly such that, when the sample probe is at the lower
sample probe position and the sample stirring rod is at the lower sample
stirring
rod position, the sample probe arm being movable between a first sample probe
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S arm position wherein the sample probe is immediately above the sample
extraction site and a second sample probe arm position wherein the sample
probe
is immediately above the cuvette mixing site;
(f) a sample probe positioning motor for moving the sample
probe between the lower sample probe position and the upNer sample probe
position;
(g1 a sample stirring rod positioning motor for moving the
sample stirring rod between the lower sample stirring rod position and the
upper
sample stirring rod position;
(h) a sample stirring rod rotating motor for rotating the sample
stirring rod;
(i) a sample probe pressure altering assembly for alternatively
applying a positive pressure and a negative pressure to the interior chamber
of the
sample probe;
(j) a reagent probe arm assembly attached to the body, the
2 0 reagent probe arm assembly including ( 1 ) a reagent probe arm, (2) a
hollow
reagent probe having an internal chamber, an open lower end and an open upper
end and (3) an elongate rotatable reagent stirring rod having a lower end and
an
upper end, the lower end of the reagent stirring rod including a reagent
stirring rod
paddle attached thereto, the reagent probe and the reagent stirring rod being
disposed generally vertically in close proximity to one another, the reagent
probe
being vertically movable between a lower reagent probe position and an upper
reagent probe position, the reagent stirring rod being movable of the reagent
probe between a lower reagent stirring rod position and an upper reagent
stirring
rod position, the reagent probe and reagent stirring rod being disposed within
the
reagent probe arm assembly such that, when the reagent probe is at the lower
reagent probe position and the reagent stirring rod is at the lower reagent
stirring
rod position, the reagent probe arm being movable between a first reagent
probe
arm position wherein the reagent probe is immediately above the reagent
extraction site and a second reagent probe arm position wherein the reagent
3 5 probe is immediately above the cuvette mixing site;
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(k) a reagent probe positioning motor for moving the reagent
probe between the lower reagent probe position and the upper reagent probe
position;
(I) a reagent stirring rod positioning motor for moving the
reagent stirring rod between the lower reagent stirring rod position and the
upper
reagent stirring rod position;
(m) a reagent stirring rod rotating motor for rotating the reagent
stirring rod;
(n) a reagent probe pressure altering assembly for alternatively
applying a positive pressure and a negative pressure to the interior chamber
of the
reagent probe;
(o) a cuvette wash station attached to the body, the cuvette
wash station including at least one motorized hollow cuvette wash station
probe
having an internal chamber, an open lower end and an open upper end, the
cuvette wash station being disposed such that the cuvette wash station probe
is
immediately above the cuvette washing site; and
(p) a cuvette wash station probe supply and disposal assembly
for alternatively (1 ) providing pressurized washing liquid from a source of
washing
liquid to the cuvette wash station probe for washing a cuvette disposed within
the random access analyzing station at the cuvette washing site and (2)
providing
a negative pressure to the interior chamber of the cuvette wash station probe
for
removing waste liquids from a cuvette disposed within the random access
analyzing station at the analyzing site and for transferring such waste
liquids to a
suitable disposal site.
Preferably, on each probe arm the' distance between the probe and
the stirring rod at their respective lowermost positions is between about 1.7
and
about 5.3 mm, more preferably between about 1.7 and about 3.5 mm, most
preferably between about 1.7 and about 3 mm.
Also, it is preferably that on each probe arm, the probe and the
stirring rod be vertically movable independently of one another.
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Preferably, each probe and stirring rod are attached to their probe
arm by a rack and pinion assembly for raising and lowering the probe and
stirring
rods. This feature allows for independent operation of the probe and stirring
rod
while providing that the lower tip of the probe and stirring rod (at their
lowermost
positions) are very close to one another. This, in turn, allows the use of
smaller
reaction containers requiring a minimum of expensive reagents.
In a preferred embodiment, the sample station comprises a rotating
sample carousel having an exterior wall with a retainer assembly for retaining
a
card displaying bar-coded information on the exterior wall. This allows a bar
code
reader disposed within the device to read bar-coded information regarding the
reagent containers used in the device.
In another preferred embodiment, the sample station comprises a
plurality of dilution sections, each having a plurality of dilution cups. This
feature
allows the device to minimize the use of expensive reagents.
In still another preferred embodiment, the cuvette wash probe
supply and disposal assembly includes a waste trap assembly comprising (a) a
waste trap reservoir, (b) a waste collector bowl disposed below the waste trap
reservoir, (c) a vertically disposed connector conduit for connecting the
waste
trap reservoir in fluid communication with the waste collector bowl. the
connector
conduit having an uppermost lip over which waste liquids within the waste trap
reservoir can spill over into the waste collector bowl. (d) a connector
conduit
check valve for preventing the upward flow of liquids and pressurized air
within
the connector conduit from the waste collector bowl to the waste trap
reservoir,
(e) an inlet port in the upper portion of the waste trap reservoir for
receiving
waste liquid from the cuvette wash station probe, (f) an outlet port in the
bottom
of the waste collector bowl for draining liquid within the waste collector
bowl to a
suitable waste disposal facility via a drain conduit, (g) a drain conduit
check valve
disposed within the drain conduit to prevent liquids to flow into the waste
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collector bowl via the drain conduit, (h) a level sensor for sensing the level
of
liquid within the waste collector bowl and emitting a corresponding level
sensor
signal, (i) a switch assembly for alternatively applying pressure and vacuum
to the
waste collector bowl, (j) a waste trap controller for receiving the level
sensor
signal from the level sensor and therewith controlling the switching assembly
to
allow the application of vacuum and pressure to the waste collector bowl in
such
a way that (i) when the level of liquid within the waste collector is below a
preselected set point, vacuum is applied to the waste collector bowl to draw
waste liquid from the waste trap reservoir and (ii) when the level of liquid
within
the waste collector is at the preselected set point, pressure is applied to
the
waste collector bowl to blow down waste liquid within the waste collector bowl
to the drain conduit.
The invention is also a method for analyzing a plurality of liquid
samples using the device described above.
The invention is also a chemical test reagent kit for use in an
automated testing machine having an internal bar code reader. The kit
comprises
at least one container containing reagent and a bar code card containing bar
coded information regarding the reagent. The bar code card is sized and
dimensioned to be read by the internal bar code reader of an automated testing
machine.
The invention provides significant improvements over the prior art
by reducing reagent costs and operating expenses white increasing throughput,
accuracy and reliability.
DESCRIPTION OF THE DRAWINGS
These and other features, aspects and advantages of the present
invention will become better understood with reference to the following
description, appended claims and accompanying drawings where:
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Figure 1 is a schematic plan view of an automated analyzing
machine having features of the invention;
Figure 2 is a front view of an automated analyzing machine having
features of the invention;
Figure 3 is a perspective view of a sample carousel having features
of the invention;
Figure 4A is a perspective view of a dilution section having features
of the invention;
Figure 4B is a plan view of the dilution section of Figure 4A;
Figure 4C is a cross-sectional side view of the dilution section
shown in Figure 4B, taken along line 4C-4C;
Figure 4D is a bottom side view of the dilution container shown in
Figures 4A-4C;
Figure 5A is a perspective view of a reaction cuvette module useful
in the invention;
Figure 5B is a cross-sectional side view of the reaction cuvette
module shown in Fgure 5A;
Figure 6A is a perspective view of a sample probe arm assembly
having features of the invention;
Figure 6B is a cut-away view of the sample probe arm assembly
shown in Fgure 6A;
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CA 02501895 1997-06-30
Figure 6C is a front view of a sample stirring rod useful in the
invention;
figure 6D is a side view of the sample stirring rod shown in Figure
6C;
Figure 7A is a perspective view of a reagent probe arm assembly
having features of the invention;
Figure 7B is a cut-away view of the reagent probe arm assembly
shown in Figure 7A;
Figure 7C is a front view of a reagent stirring .~od useful in the
invention;
Figure 7D is a side view of the reagent stirring rod shown in Figure
7 C;
Figure 8 is a perspective view of a cuvette wash station useful in
the invention;
Figure 9A is an exploded view of a waste trap assembly having
features of the invention;
Figure 9B is a cross-sectional view of the fully assembled waste
trap assembly shown in Figure 9A;
Figure 9C is a cross-sectional side detail view of a valve useful in
the waste trap assembly shown in Figures 9A and 9B;
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Figure 9D is a plan view of a flexible desk useful in the waste trap
assembly shown in Figures 9A - 9C; and
Figure 10 is a perspective view of a sample container rack having
features of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The following discussion describes in detail one embodiment of the
invention and several variations of that embodiment. This discussion should
not
be construed, however, as limiting the invention to those particular
embodiments.
Practitioners skilled in the art will recognize numerous other embodiments as
well. For a definition of the complete scope of the invention, the reader is
directed to the appended claims.
Figures 1 and 2 show an automated analyzing machine 10 having
features of the invention. The machine 10 comprises a body 12, a sample
station
14, a reagent station 16 and a random access analyzing station 18.
The body 12 is generally a cabinet providing a housing for the
various operative components used in the analyzing machine 10. The body 12 is
typically made from a lightweight metal such as a lightweight sheet steel. The
body 12 can include a canopy ~not shown) for fully enclosing the operative
components of the machine 10.
The sample station 14 is sized and dimensioned to retain a plurality
of sample containers 20. The sample station 14 has at least one sample
extraction site 22.
The sample station 14 preferably comprises a revolving sample
carousel 24 as illustrated in Figure 3. Typically, the sample carouse! 24 is
made
from a lightweight metal or molded plastic. The sample carousel 24 is
preferably
CA 02501895 1997-06-30
sized and dimensioned to retain a plurality of sample containers 20, one or
more
diluent containers 26, and a plurality of dilution sections 28.
In the embodiment shown in the drawings, the sample carousel 24
comprises a carousel retainer assembly 40 for retaining a sample container
rack
30 on the exterior wall 32 of the sample carousel 24. Such retainer assembly
40
can be slots as shown in the embodiment illustrated in the drawings.
The sample rack 30 preferably comprises a simple container rack
retainer assembly 39 for retaining a card 37 displaying bar-coded information
on
the forward portion 41 of the sample container rack 30. Such sample container
rack retainer assembly 39 can be resilient clips as shown in the embodiment
illustrated in Figure 10. However, many other ways of attaching the bar-coded
card 37 to the forward portion 41 of the sample container rack 30 can also be
used as well, including clamps, clips, prongs, snaps, buttons, hook and loop
fasteners, pins, etc. It is preferable that the sample container rack retainer
assembly 39 allows the operator to quickly and easily attach and later de-
attach a
bar code card 37 from the forward portion 41 of the sample container rack 30,
most preferably without the use of tools.
In this embodiment, each sample container rack 30 houses nine
individual sample containers 20 in a generally upright disposition.
The sample carousel 24 shown in Figure 3 has four diluent
container retention locations-~36 and four dilution section retention
locations 38.
The dilution sections 28 each comprise a plurality of dilution cups 42 as
shown in
Figures 4A - 4C. Typically, each dilution section 28 is made from a molded
plastic. Preferably, each dilution section 28 is easily installed and removed
from
the sample carousel 24 for ease of cleaning. It is also preferable that the
dilution
sections 28 be easily and quickly installed into and deinstalled from the
sample
carousel 24 without use of tools. The embodiment shown in the drawings has
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CA 02501895 1997-06-30
resilient nodes 44 which allow the dilution sections 28 to snap fit in the
dilution section
retention locations 38.
Each dilution cup 42 holds between about 0.01 and about 1.0 milliliters of
liquid. As shown in Figure 4C, each dilution cup 42 is tapered at the bottom
to form a
dilution cup narrow well 46 so that small amounts of liquid within the
dilution cup 42
puddle within the narrow well and thereby remain easily extractable from the
dilution
cup 42. Each dilution cup narrow well 46 typically can retain between about 10
microliters and about 100 microliters. This feature minimizes reagent waste.
This
feature is especially important where the dilution cups 42 are made from a
plastic
material which is hydrophobic. In such cases, small amounts of liquid within
the dilution
cups 42 tend to bead instead of puddling, making it difficult to extract the
liquid from the
dilution cup 42.
The sample carousel 24 is movable by a rotating motor (not shown) such
that each sample container 20 disposed on the sample carousel 24 can be
alternatively
positioned under and moved away from the one sample extraction site 22.
Preferably, the sample station 14 further comprises a sample station bar
code reader 4T for reading bar-coded information on the sample containers 20
within
the sample station 14 and/or on a bar code card 3T disposed on the forward
portion 41
of the sample container rack 30.
The reagent station 16 is sized and dimensioned to retain a plurality of
reagent containers 48 and has at least one reagent extraction site 50. The
reagent
station 16 is movable within the body such that individual reagent containers
48
disposed
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S within the reagent station 16 can be alternatively moved to and away from
the
reagent extraction site 50.
Like the sample station 14, the reagent station 16 preferably
comprises a rotatable reagent carousel 52, typically made from a lightweight
metal or molded plastic. The reagent carousel 52 is rotated by a reagent
station
motor (not shownl.
Preferably, the reagent station 16 is refrigerated, such as to a
temperature of about t 5°C. Such refrigeration preserves reagent life
and
1 S minimizes reagent evaporation.
Preferably, the reagent station 16 further comprises a reagent
station bar code reader 53 for reading bar-coded information on reagent
containers 20 within the reagent station 16 and/or on the exterior of the
reagent
2 0 carousel 24.
The random access analyzing station 18 is sized and dimensioned
to retain a plurality of reaction cuvettes 54 of the type commonly known in
the
nephelometric and turbimetric arts. The random access analyzing station 18
25 comprises at least one cuvette mixing site 56., one random access analyzing
station analyzing site 58 and a cuvette washing site 60.
Like the sample station 14 and the reagent station 16, the random
access analyzing station 18 preferably comprises a rotatable carousel 62 which
is
30 rotated by a random access analyzing station motor (not shownl.
In the embodiment shown in the drawings, the reaction cuvettes ~4
are disposed in cuvette modules 64, each cuvette module 64 containing three
individual cuvettes 54. The cuvette modules 64 are shown in Fgures 5A and 5B.
3 S Each cuvette module 64 has prongs 66 to facilitate firm attachment to the
random access analyzing station carousel 62. To minimize the cost of expensive
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reagent, it is important that the cuvettes 54 be made as small as practically
possible.
In most applications, it is preferable that the random access analyzing
station 18 be operatable at a fixed elevated temperature, such as about
37°C. To
accomplish this, the random access analyzing station 18 preferably includes
means for
circulating heated air upwardly through the random access analyzing station
18.
The random access analyzing station 18 further comprises a random
access analyzing station analyzer 68 which is disposed proximate to the random
access
analyzing station analyzing site 58 for determining at least one parameter of
a sample
disposed within a cuvette 54 within the random access analyzing station 18. In
a
preferred embodiment, the random access analyzing station analyzer 68 is a
nephelometer and turbidimeter combination. Such a combination is welt-known in
the
art. A detailed description of a typical nephelometer and turbidimeter
combination is set
forth, for example, U.S. Patent No. 5,296,195.
In a typical nephelometer and turbidimeter combination, there is a first
light source 70 disposed proximate to the random access analyzing station
analyzing
site 58 for directing a first beam of light. through a cuvette 54 disposed at
the random
access analyzing site 58 to a first light receptor 72. In a preferred
embodiment, this first
light source 70 is a visible diode laser emitting light at a wave length
between about 600
and about 850 nm. Preferably, a second light source 74 is also disposed
proximate to
the random access analyzing station analyzing site 58 for directing a second
beam of
light through a cuvette 54 disposed at the random access analyzing site 58 to
a second
light receptor 76. In a preferred embodiment, this second light source 74 is a
light
emitting diode capable of emitting light at a wave length between about 850
and about
1050 nm. Both first and second light receptors 72 and 76 measure the amount of
scattered light as the first and second light beams 70 and 74 are projected
through the
cuvette 54. In the embodiment shown in Figure 1, the first light receptor 72
is disposed
below the reaction cuvette to measure the amount of light scattered at a
90° angle with
respect to the first beam of light. As is well-known in the art, such
scattering of light can
be accurately correlated with one or more specific parameters of the liquid
within the
cuvette 54.
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Preferably, the random access analyzing station 18 further comprises an
onboard control sample 78. Such onboard control sample 78 allows the user to
program the machine to automatically calibrate the random access analyzing
station
analyzer 68 during normal operation of the machine 10. This feature maximizes
accuracy and reliability over similar machines of the prior art. This feature
also
increases throughput by eliminating the need to periodically shut down the
machine 10
to calibrate the random access analyzing station analyzer 68.
The analysis machine 10 of the invention further comprises a sample
probe arm assembly 80 such as shown in Figures 6A-6D. The sample probe arm
assembly 80 includes a sample probe arm 82, a hollow sample probe 84 and a
rotatable sample stirring rod 86. The sample probe 84 has an internal chamber
88, an
open lower end 90 and an open upper end 91. A sample probe pressure altering
assembly 92 is provided to alternatively place pressure or a vacuum on the
internal
chamber 88. Preferably, the pressure altering assembly 92 comprises a syringe
94.
CA 02501895 1997-06-30
S The sample probe 84 is disposed generally vertically in the sample
probe arm 82 and is movable by a sample probe motor 96 between a lower
sample probe position and an upper sample probe position.
The sample stirring rod 86 has a lower end q8, an upper end 100
and a stirring rod paddle 102. The sample stirring rod 86 is~ also disposed
generally vertically in the sample probe arm 82 and is movable by a sample
stirring rod motor 104 between a lower sample stirring rod position and an
upper
sample stirring rod position. The sample stirring rod is operatively rotated
by a
sample stirring rod rotating motor 105.
Preferably, the raising and lowering of the sample stirring rod 86 is
independent of the raising and lowering of the sample probe 84. This provides
speed and flexibility over important similar devices in the prior art which
can only
raise and lower the stirring rod 86 at the same time that the probe 84 is
raised
and lowered.
Preferably, the sample stirring rod 86 and the sample probe arm 84
are both raised and lowered using a rack and pinion assembly 106. Such rack
and pinion assembly 106 allows the sample probe 84 and the reagent probe 86 to
2 S be mounted close enough to one another to achieve the close proximities of
their
respective lower ends 90 and 98 described immediately below.
The sample probe 84 and the sample stirring rod 86 are disposed
within the sample probe arm 82 at a slight angle with respect to one another.
Preferably, this angle a is between about 2.4° and about 2.6°.
The sample probe
84 and the sample stirring rod 86 are angled towards one another so that, when
both the sample probe 84 and the sample stirring rod 86 are at their
respective
lower positions, the distance between the lower end 90 of the sample probe 84
and the lower end 98 of the sample stirring rod 86 is between about 1.7 mm and
about 5.3 mm, more preferably between about 1.7 mm and about 3.5 mm, most
preferably between about 1.7 mm and about 3 mm. By structuring the sample
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CA 02501895 1997-06-30
probe 84 and .the sample stirring rod 86 so as to be so close to one another
at
their respective lower positions 90 and 98, the sample probe 84 and sample
stirring rod 86 can effectively be used within reaction cuvettes 54 which are
much smaller than those used in prior art analyzing machines. The ability to
use
such small reaction cuvettes 54 results in significant reagent savings to the
operator. It also allows the operator to conduct clinical analyses with very
small
samples.
The device of the invention further comprises a reagent probe arm
assembly 108 such as shown in Figures 7A - 7D. The reagent probe arm
assembly 108 includes a reagent probe arm 110, a hollow reagent probe 112 and
a rotatable reagent stirring rod 114. The reagent probe 112 has an internal
chamber 116, an opened lower end 118 and an open upper end 120. A reagent
probe pressure altering assembly 122 is provided to alternatively place
pressure
or a vacuum on the internal chamber 116. Preferably, the pressure altering
assembly comprises a syringe 124.
The reagent probe 112 is disposed generally vertically in the
reagent probe arm 110 and is movable by a reagent probe motor 126 between a
lower reagent probe position and an upper reagent probe position.
The reagent stirring rod 114 has a tower end 128, an upper end
130 and a stirring rod paddle 132. The reagent stirring rod 114 is also
disposed
generally vertically in the reagent probe arm 1 i 0 and is movable by a
reagent
stirring rod motor 132 be between a lower reagent stirring rod position and an
upper reagent stirring rod position. As is the case with respect to the sample
probe 84 and the sample stirring rod 86, it is preferable that the raising and
lowering of the reagent stirring rod 114 be independent of the raising and
lowering of the reagent probe 112.
It is also preferable that the reagent stirring rod 114 and the
reagent probe 112 be raised and lowered using a rack and pinion assembly 134.
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Such rack and pinion assembly 134 allows the reagent prone 112 and the reagent
stirring rod 114 to be mounted close enough to one another to achieve the
close
proximities at their lower ends 118 and 128 described immediately below.
Like the sample probe 84 and the sample stirring rod 86, the
reagent probe 112 and reagent stirring rod 114 are disposed within the reagent
probe arm 110 at a slight angle with respect to one another. Preferably, this
angle (3 is between about 2.4°and about 2.6° The reagent probe
112 and the
reagent stirring rod 114 are angled towards one another for the same reason
that
the sample probe 84 and the sample stirring rod 86 are angled towards one
another: that is to provide for a convergence of the lower ends 118 and 128 of
the reagent probe 112 and the reagent stirring rod 114 to a distance between
about 1.7 mm and about 5.3 mm, more preferably between about 1.7 and about
3.5 mm, most preferably between about 1.7 and about 3 mm. This close
proximity of the tower ends 118 and 128 of the reagent probe 112 and the
reagent stirring rod 114 allow the use of very small reaction cuvettes 54.
Preferably, both the sample probe arm 82 and the reagent probe
arm 108 comprise level controllers (not shown) for determining the elevation
of
the probes 84 and 112 and/or the stirring rods 86 and 114 relative to a liquid
2 5 level.
The machine of the invention 10 further comprises a cuvette wash
station 130 attached to the body. The cuvette wash station 130 includes at
feast one hollow cuvette wash station probe 132 having an internal chamber
134,
an open lower end 137 and an open upper end 139. The cuvette wash station
130 is disposed such that the cuvette wash station probe 132 is immediately
above the cuvette washing site 60.
The cuvette wash station probe 132 is movable by a cuvette wash
station motor (not shown) between a lower cuvette wash station probe position
and an upper cuvette wash station probe position.
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In the embodiment shown in Figure 8, the cuvette wash station
probe 132 comprises two concentrically disposed cuvette wash station probes
132a and 132b. One probe 132 is used to evacuate the contents of a cuvette
and transmit such contents to a suitable disposal site 135. The other probe
132
is used to provide the cuvette with a washing solution.
The device of the invention further comprises a cuvette wash
station probe supply and disposal assembly 136 for alternatively (1) providing
pressurized washing liquid from a source of washing liquid to the cuvette
washing
1 S station probe 132 for washing a cuvette 54 disposed at the cuvette washing
site
60 and (2) providing a negative pressure to the interior chamber 134 of the
cuvette wash station probe 132 for removing waste liquids from a cuvette 54
disposed within analyzing site 60 and for transferring such waste liquids to a
suitable disposal site 135.
A preferred wash station probe supply and disposal assembly 136
comprises a waste trap assembly 138 shown in Figures 9A - 9D. The waste trap
assembly 138 comprises a waste trap reservoir 140 and a waste collector bowl
142 disposed below the waste trap reservoir 140. A vertically disposed
2 S connector conduit 144 connects the waste trap reservoir 140 in fluid
communication with the waste collector bowl 142. The connector conduit 144
has an uppermost lip 146 over which waste liquids which collect within the
waste trap reservoir 140 spill over into the waste collector bowl 142. The
connector conduit 144 has a connector conduit check valve 148 for preventing
the upward flow of liquids and pressurized air within the connector conduit
144
from the waste collector bowl 142 to the waste trap reservoir 140.
The waste trap reservoir 140 has an inlet port 150 in the upper
portion of the waste trap reservoir 140 for receiving waste liquid from the
cuvette
3 S wash station 130. The waste collector bowl 142 has an outlet port 152 in
the
bottom of the waste collector bowl 142 for draining liquid within the waste
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CA 02501895 1997-06-30
collector bowl 142 to a suitable waste disposal facility via a drain conduit
154.
The drain conduit 154 has a drain conduit check valve 156 to prevent liquids
from flowing back into the waste collector bowl 142 via the drain conduit 154.
A level sensor 158 is disposed within the waste collector bowl 142
for sensing the level of liquids within the waste collector bowl 142 and
emitting a
corresponding level sensor signal. In operation, the waste trap reservoir 140
is
operatively connected to a source of vacuum. Also, the waste collector bowl
142 is operatively connected via a switch 160 to a source of vacuum and to a
source of pressurized air.
The waste trap assembly 138 further comprises a waste trap
controller (not shown) for receiving the level sensor 158 signal from the
level
sensor and using that signal to control the application of a vacuum and
pressure
to the waste collector bowl in the following way: (i) when the level of liquid
within the waste collector bowl 142 is below a preselected set point, vacuum
is
applied to the waste collector bowl 142 to draw waste liquid from the waste
trap
reservoir 140 and (ii) when the level of liquid within the waste collector
bowl 142
is at the preselected set point, pressure is applied to the waste collector
bowl
142 to blow down waste liquid within the waste collector bowl 142 to the drain
2 5 conduit 154.
The waste trap assembly connector conduit check valve 148
preferably comprises an inlet conduit 162, a valve seat 164 disposed within
the
inlet conduit 162 and in fluid tight communication therewith, an outlet
conduit
166 disposed below the valve seat 164 and in fluid tight communication
therewith and a plug 168 loosely disposed within the valve seat 164 such that
( 1 )
when the pressure within the inlet conduit is equal to or greater than the
pressure
within the outlet conduit 166, the plug 168 is not held tightly against the
valve
seat 164 so as to allow liquid waste within the inlet conduit 162 to gravitate
into
3 S the outlet conduit 166 and (2) when the pressure within the Met conduit
162 is
less than the pressure within the outlet conduit 166, the plug 168 is held
tightly
CA 02501895 1997-06-30
S against the valve seat 164 so as to prevent liquid waste within the inlet
conduit
162 from gravitating into the outlet conduit 166 and to prevent pressurized
air in
the outlet conduit 166 from flowing through the inlet conduit 164 into the
waste
trap reservoir 140.
~ Preferably, the plug 168 is a flexible disk as shown in the drawings.
The flexible disk has at least one central aperture 170 which is off-set from
the
inlet conduit i62.
Preferably, the waste trap 138 assembly further comprises (a) a
vacuum source inlet port 172 disposed in the wash trap reservoir 140, the
vacuum source inlet port 172 being connectable to a source of vacuum, (b) a
three way valve 174 having a common port 176, a normally open port 178 and a
normally closed port 180, (c) a first pressure source conduit 181 connected in
fluid tight communication between the common port 176 and the waste
collection bowl 142, (d) a second pressure source conduit 182 connected in
fluid
tight communication between the normally open port 178 and the waste trap
reservoir 140, and (e) a third pressure source conduit 184 connected in fluid
tight
communication between the normally closed.port 180 and a source of air
pressure.
This waste trap assembly 138 provides significant advantages over
prior art waste trap assemblies. The waste trap assembly 138 of the invention
requires only one vacuum storage reservoir 140 and one vacuum pump.
Moreover, a wash cycle need not be interrupted for liquid waste evacuations.
Also, no external waste pump is required as is generally required by prior art
systems. This is because the waste trap assembly 138 of the invention relies
on
air pressure to drive the waste out of the assembly. Some prior art systems
also
use pressurized air to force waste out of a waste trap assembly. However, such
systems are wasteful of vacuum since each time the reservoir level signals for
the
3 S three-way valve to switch, the entire vacuum contents of the reservoir are
replaced by pressurized air to force waste to the pump. This can significantly
21
CA 02501895 1997-06-30
slow down operation of the machine since replenishing the vacuum can take 16
seconds and more. Moreover, a relatively large vacuum pump is required.
Preferably, the analyzing machine 10 of the invention further
comprises a controller 186 for controlling the operation of the motors,
analyzers
and bar code readers. Preferably, the controller 186 includcs a digital
computer
which is also programmed to receive the results from the analyzer 68 and
report
those results to the operator in an efficient format.
In operation, the operator of a preferred embodiment of the analysis
1 S machine loads the reagent station 16 with premixed reagent from a kit. The
kit
includes one or more reagent containers 48 containing premixed reagent and a
bar code card having bar-coded information thereon regarding the reagent
within
the kit.
After loading the reagent containers 48 into the reagent station 16,
the operator places the bar-coded card 37 from the reagent kit on the forward
portion 41 of the sample container rack 30 using the sample container rack
retainer assembly 40. The operator instructs the sample station bar code
reader
47 to read into the controller the bar-coded information contained on the bar-
coded card 37. The operator then removes the bar-coded card 37 from the
sample container 30.
The operator then loads the sample carousel 24 with sample
containers 20 containing samples to be analyzed. The sample containers 20 are
loaded into sample container racks 30 and the sample container racks 30 are
attached to the exterior perimeter of the sample carousel 24. A label
containing
bar-coded information regarding the identity of each of the samples and the
analyses to be run on each of the samples is attached to each sample container
20. The operator then places diluent containers 26 in the sample carousel 24
and
places clean dilution sections 28 in the sample carousel 24. The operator then
engages the machine 10 which carries out the following steps automatically.
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CA 02501895 1997-06-30
S
The sample carousel 24 is rotated, making frequent stops.
Whenever a container 20 is disposed in front of the sample station bar code
reader 47, the bar code reader 47 reads the bar-coded information on the label
on
the sample container 20 and passes that information along to the controller
186.
The sample probe arm 82 moves the sample station probe 84 to a
position immediately above the sample extraction site 22. The sample probe 84
is lowered from its upper probe position until the sample probe level
controller
senses the fact that the sample probe 84 is below~the surface of the sample
5 within the sample container 20 positioned at the sample extraction site 22.
The sample probe pressure altering assembly 92 is then caused to
draw a vacuum in the sample probe internal chamber 88. This, in turn, causes
sample within the sample container 20 to be drawn into the sample probe
internal
chamber 88. The sample probe 84 is then raised to its upper position and the
sample probe arm 82 rotates to a position over one of the dilution cups 42.
The
sample probe 84 is again lowered into the dilution cup 42 and the sample probe
pressure altering assembly 92 causes the sample within the sample probe 84 to
be discharged into the dilution cup 42.
The sample probe arm 82 then rotates the sample probe 84 to a
position immediately above one of the diluent containers 26 in the sample
station
14. The sample probe 84 is lowered from its upper position to a position below
the surface of the diiuent in the diiuent container 26 as sensed by the sample
probe level controller. The pressure altering assembly 92 causes a vacuum to
be
drawn within the sample probe internal chamber 88 and diluent is drawn into
the
sample probe 84. The sample probe 84 is then raised to its upper position and
the sample arm rotates the sample probe 84 to a position immediately above one
of the dilution cups 42. The sample probe 84 is lowered into the dilution cup
42
and the pressure altering assembly 92 pressures the diluent out of the sample
probe 84 and into the dilution cup 42.
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CA 02501895 1997-06-30
The sample stirring rod 86 is then lowered into the dilution cup 42
and the sample stirring rod rotating motor 105 is engaged to mix the sample
and
the diluent.
Next, the sample probe 84 is again lowered into the dilution cup 42
and the diluent-sample mixture is drawn into~the sample probe 84. The sample
probe arm 82 then rotates the sample probe 84 to a position immediately above
the cuvette 54 at the cuvette mixing site 56, the sample probe 84 is lowered
into
the cuvette 54, and the diluent-sample mixture is expelled from tha sample
probe
84 into the cuvette 54 by the sample probe pressure altering means 92.
Immediately before or after these steps, the controller 186 causes
the reagent probe arm 110 to maneuver immediately above the appropriate
reagent container 48 within the reagent extraction site 22 and the reagent
probe
2 0 112 is lowered into the reagent container 48 and a quantity of reagent is
drawn
into the reagent probe 112. The reagent probe 112 is then raised to its upper
position and the reagent arm 110 rotates the reagent probe 112 over the
cuvette
54 at the cuvette mixing site 56. The reagent probe 112 is then lowered into
the
cwette 54 and the reagent is discharged into the cuvette 54.
At this point, either the sample stirring rod 86 (or the reagent
stirring rod 114 depending upon which stirring rod is immediately above the
cuvette mixing site at this point in time) is lowered into the cuvette 54 and
the
rotating motor is engaged to agitate the reagent-sample mixture with the
stirring
rod paddle 102. After mixing, the stirring cod 86 is retracted to its upper
position.
The controller 186 then causes the random access analyzing
station carousel 62 to rotate the cuvette 54 having the reagent-sample mixture
3 5 past the random access analyzing station analyzing site 58. At this
analyzing site
58, the random access analyzing station analyzer 68 analyzes the contents of
the
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CA 02501895 1997-06-30
cuvette 54 and transmits that information to the controller 186. Preferably,
the
controller 186 causes the cuvette 54 to pass through the random access
analyzing station analyzing site 58 on numerous occasions and instructs the
analyzer 68 to analyze the contents on each of those numerous occasions. By
making numerous analyses of the same reagent-sample mixture, the results
ultimately reportable by the controller 186 are therefore very precise in
nature.
After tha contents of the cuvette 54 are analyzed, the random
access analyzer carousel 62 is rotated so that the cuvette 54 is immediately
below the cuvette washing site 60. At the cuvette washing site 60, the cuvette
1 S wash station probe 132 is lowered into the cuvette 54 and the contents of
the
cuvette 54 are extracted out of the cuvette 54 and sent to suitable disposal
using
the cuvette wash probe supply and disposal assembly 136. The cuvette 54 is
then washed with pressurized washing liquid and that Liquid is also sent to
disposal using the cuvette wash probe supply and disposal assembly 136. The
cuvette 54 is then clean and ready for another analysis operation.
The controller 186 is preferably programmed to keep track of a
large number of reaction cuvettes 54 in various stages of the analysis
process.
The controller 186 causes the random access analyzing station carousel 62 to
rotate with great rapidity, moving any of the large number of active cuvettes
54
to the various cuvette sites for one or more of the various operations
described
above. fn this way, the analyzing machine 10 can carry out a large number of
analyses in a very small amount of time.
Periodically during normal operation of the machine, the controller
186 causes the random access analyzing station analyzer 68 to analyze the
contents of the onboard control sample 78. If the results of this analysis
suggests that the analyzer 68 is out of calibration, the analyzer 68 is
automatically recalibrated.
CA 02501895 1997-06-30
S
The invention provides significant improvements over the prior art
by reducing reagent costs and operating expenses while increasing throughput,
accuracy and reliability.
Although the present invention has been described in considerable
detail with reference to certain preferred versions thereof, other versions
are
possible. Therefore, the spirit and scope of the appended claims should not be
limited to the description of the preferred versions contained herein.
26
