Reaction vessel and method for the handling thereof
The present invention relates to a new type of a reaction vessel, Le. a cuvette, for usage in
automatic analyzers and to a cuvette incubation method. More precisely, the present in-
vention relates to a cuvette and an incubation method according to the preambles of the
independent claims.
As known, disposable and reusable cuvettes have been used in automatic analyzers as
individual cuvettes or as sets of cuvettes. Cuvettes are vessels into which a sample to be
analyzed and possible other substances to be used in the test are portioned out for the
analysis. Reusable cuvettes are cleaned between the analyses, whereas disposable cu-
vettes are designed to receive only one sample during their life span. The cleaning of the
cuvettes between the tests is laborious due to the properties of the cleaning products and
to the potentionally dangerous substance to be removed. Thus, especially when perform-
ing a large amount of tests, disposable cuvettes are favored, which are delivered o waste
treatment after use and it is certain enough that they are clean at least when taken into
use.
We already know disposable cuvettes that there are manufactured as a continuous chain
of cuvettes, which can be bent about two axes into a spiral shape and which is adapted to
be moved wrapped around the moving orbicular bodies of the analyzer. Likewise, col-
umns of cuvettes are already known, which can be moved from cuvette specific protru-
sions, between which conveying members, such as toothed belts, are adapted to pene-
trate. As known, the attachment of the cuvette or the set of cuvettes to a testing apparatus
is performed with external shaped connection of the cuvette, such as pin couplings, and
such that the receiving means of me testing apparatus comprising flexible separating
walls hold the cuvette in place.
However, the prior art has some disadvantages. The cuvettes according to prior art are
usually suitable to be used in only one application, whereby they have not been suited to
be used in several different types of analyzers and incubators. The known cuvette-
incubator-pairs have included a plurality of maneuvers and precision mechanics and,
thus, not being particularly robust in structure nor in operation. In addition, said pairs are
typically test-oriented, which means that only analyses of a specific test, typically a pho-
tometric analysis, is performed in one test sequence. This is why there have been gratuit-
ous delays in receiving patient or sample specific results. Likewise, the abundance of
maneuvers has resulted in that the sample-carrying cuvettes being exposed to several
contacts, which has worn their outer surfaces. In some cases excess wear has have im-
paired the optical properties of the clear vessels. The wear and tear is especially intensive
when the vessels are being washed, which is disadvantageous only with reusable cu-
vettes.
The object of the present invention is to solve at least part of the aforementioned prob-
lems and to provide an improved cuvette and a handling method thereof.
A cuvette according to the invention comprises two positions, which are connected by a
separating wall, and at least one bracket at the outermost positions being able to support
the cuvette and yield elastically when pressed inward. The separating walls between the
cuvette positions allow for the elastic bending of the cuvette about its vertical axis. More
precisely, the cuvette according to the present in invention is characterized by what has
been stated in the characterizing portion of the independent apparatus claim.
In a cuvette handling method according to the present invention a cuvette is transported
from its brackets to an incubator and it is bent into a curved shape after which the cuvette
is loaded into an incubator opening in which it remains by means of its own spring back
factor. Hereafter the sample to be analyzed is portioned out into the sample space of the
position of the cuvette, it is analyzed while being in the incubator, and the cuvette is fi-
nally removed from the incubator opening. More precisely, the handling method accord-
ing to the present invention is characterized by what has been stated in the characterizing
portion of the independent method claim.
Considerable advantages are gained with the aid of the invention. Due to the brackets and
elasticity along the vertical axis, the cuvette according to the present invention can ad-
vantageously be used in apparatuses that automatically analyze samples. Due to the suit-
able yielding properties the cuvette may be transported to an incubator and loaded therein
without scratching the vulnerable optical surfaces of the cuvette. Likewise, the brackets
contribute to bending the cuvette tightly into the exact bow for it to be throughout its
length in continuous contact with the walls of the receiving incubator opening. With the
aid of the brackets is also easy to place and center the cuvette into the receiving incubator
opening.
The loading and ejecting movement of the handling method comprises only one direction
and movement, whereby the method is robust and reliable. Due to the yielding properties
in relation to the vertical axis of the cuvette, neither excess shaped connections nor preci-
sion mechanics is required. For the same reason one type of cuvette can be used in vari-
ous different incubators resulting in considerable cost savings for the user. In addition to
the previously mentioned advantages, the sufficiently long brackets and the separating
walls separating the positions of the cuvette according to the present invention guarantee
that there is an even temperature distribution during the test sequence in the cuvette.
Thus, the heat conducting from one sample space to another does not compromise the
accuracy and reliability of the test.
In the following, certain embodiments of the present invention are discussed with refer-
ences to the accompanying drawings:
Fig. 1 shows an isometric view of a cuvette with 10 positions.
Fig. 2 shows a side view of the cuvette of Fig. 1.
Fig. 3 shows an elevated view of the cuvette of Fig. 1.
Fig. 4 shows an incubator and a cuvette, which can to be adapted to its orbicular body.
Fig. 5 shows the loading funnel of the incubator of Fig. 4.
Fig. 6 shows a cuvette according to another embodiment of the present invention
equipped with single projection brackets.
As illustrated in Fig. 1, the cuvette 10 comprises positions 20, which are in line next to
each other. By a cuvette 10 is meant in this context a sample-receiving member with at
least one position 20 for receiving the sample and for storage at least during analysis. The
position 20 is a tubular vessel wherein a confined sample space 28 for a sample to be
analyzed is formed and which is limited by the walls of the vessel. The position 20 has,
according to one embodiment, a rounded quadrangular shaped cross-section and is gen-
erally shaped such that the sides of the opening of the sample space 28 are considerably
shorter than the depth thereof. The sample space 28 can also have another shape. In this
context, the direction of the longest side of the sample space 28 of the position 20, i.e. the
depth, is called the vertical axis. Correspondingly by a horizontal axis is meant the Carte-
sian axes orthogonal to the vertical axis.
The cuvette 10 has, according to one embodiment of the invention, 10 positions, which
are separated from each other by separating walls 22. The separating wall 22 is an isth-
mus-like connecting part between two positions 20. As illustrated in Figs. 1 and 2, the
separating wall 22 is essentially in the middle of the narrow faces of the parallel positions
20 such that the separating wall 22 extends from the upper edge of the cuvette 10 to
about half way of the side face of the positions 20. In other words, the separating wall 22
does not connect the positions 20 over their whole length, but only along their upper half.
The basic idea of the separating wall 22 is to be a connecting element, which does not
contribute to transfer heat from position to another, but on the contrary isolates the posi-
tions 20 from each other. Thus, the heat conducted between the positions 20 remains as
minimal as possible, which improves the accuracy of the analysis.
One essential feature of the separating wall 22 is its elasticity. As illustrated in Fig. 3, the
separating walls 22 are rather thin compared to the walls of positions 20, especially com-
pared to their vertical length. Due to the profile of the separating walls 22 and the elastic
material thereof, the cuvette 10 can be bent about its vertical axis, i.e. about the axis di-
rected orthogonally upward from the plane of Fig. 3. By elastic material is in this context
meant a material, which is elastic enough to cope with intended deformations it expe-
riences. The material of the cuvette 10 and especially of the separating wall 22 is selected
such that the construction may be exposed to bending, whereby the separating walls 22
experience elastic deformation, due to which elasticity the cuvette 10 tends to react
against the bending thus tautening itself back to its original position. Thus, the elasticity
of separating walls 22 is essential, because the structure must remain elastic also under
bending strain for reasons explained later on. Besides elasticity the material must have
suitable optical properties at least as positions 20 are concerned. Plastic, especially acryl,
is for example a sufficiently elastic and suitable bright material. Alternatively the cuvette
10 may be manufactured of more than one material. In this case, parts requiring yielding
properties, such as brackets 24 and separating walls 22, can be made of essentially elastic
material, such as polyurethane, and parts requiring optical properties, such as positions
20, can be made of material having good optical properties, such as acryl. Furthermore,
upon material selection, it is possible to favor materials that have good optical characte-
ristics. For example, a material can be favored, which is elastic in its application, but of
which material made cuvette 10 is not adapted to recover entirely after the bending, but
the separating walls 22 of the cuvette 10 would experience partial plastic deformation.
Thus, the cuvette 10 would remain slightly bent after use, which would indicate that the
product has been used and reuse would be prohibited.
As illustrated in Figs. 1,2 and 3, the outermost positions 20 are equipped with brackets
24. According to one embodiment of the invention, the bracket 24 consists of two protru-
sions, which are considerably shorter in the direction of the vertical axis of the cuvette 10
than the cuvette 10 and which are rather fragile in regard to their wall thickness. The pro-
trusions of the bracket 24 are oriented outward from the upper part of the outer edge of
the outermost positions 20 such that the protrusions curve towards each other. By the
outer edge of the position 20 is meant the side edge of either of the outermost position 20
not having a separating wall 22. Correspondingly, the direction oriented outward is the
horizontal direction oriented from the separating wall 22 toward the outer edge of the
position 20.
The brackets 24 are, as the separating walls 22, of elastic material, due to which they too
endure elastically the bending about their longest side. The yielding properties of the
brackets 24 are the best in the orientation direction of the cuvette 10. Thus, the protru-
sions of the brackets 24 persist the compression toward the position 20. The elasticity of
the brackets 24 is essential, because the structure must remain elastic under compression
due to reasons explained later on. It is likewise important that the inward compressed
brackets 24 do not bend into contact with the position 20 under compression, but keep a
distance between the fixation and the position 20, whereby there is no thermal conduc-
tion between its outer edge and the fixation. If there were to occur thermal conduction
between the fixation and the outermost positions 20 of the cuvette 10, they would receive
more heat than the rest of the positions 20. In such a case, an uneven temperature distri-
button would be formed into the cuvette 10, which would impair the accuracy of the
measurement
As is apparent from Figs. 1 and 2, the positions 20 of the cuvette 10 may be equipped
with screens 26 suitable for optical analysis. According to one embodiment of the present
invention, the screen 26 is a part in the lower end of the position 20, which has been
made transparent and which has suitable optical properties for analysis. In addition, the
screen 26 must be large enough for the analyzing ray to fit reliably across the position 20
and for the small aligning errors caused by the mechanical parts of the analyzing appara-
tus not to make the measurement more difficult It is thus possible to perform analyses
based on optical examination such that the sample remains in the sample space 28 of the
position 20, whereby the number of maneuvers and sample transfers is small as possible.
In order to avoid excess wear and tear of me screen 26, its sensitive surface can be manu-
factured such that it is slightly deeper than the rest of the face of the position 20. Said
cavity provides protection from the majority of scratching contacts, whereby wearing
occurring during the packaging phase, for example, is directed toward the side faces of
the positions 20 instead of toward the screens 26.
As illustrated in Fig. 4, the cuvette 10 is especially suitable to be used in an automatic
incubator 30. According to one preferred embodiment, the incubator 30 comprises a
heated disc 32 into the outer perimeter of which openings 34 for receiving the cuvettes
10 have been made. The disc 32 is fitted with a bearing in the middle wherein means for
rotation (not shown) are arranged, with the aid of which the disc 32 can be rotated a de-
sired amount in a desired direction. The rotation means can, for example, comprise a ser-
vomotor, which has excellent positioning accuracy but which is considerably expensive.
The power transmission of the incubator 30 can be arranged with sufficient accuracy by
fitting the disc directly on the axle of a cost efficient and sufficiently accurate stepping
motor, whereby the transmission has only a necessary amount of moving parts and as
few sources of play as possible. The incubator 30 further comprises, in connection with
the disc 32, a loading track 38, along which cuvettes 10 are brought to be loaded into the
opening 34 of the disc 32. The loading track 38 is in its simplest embodiment a channel
having a U-shaped cross-section and whose horizontal edge is essentially as wide as the
lower edge of the cuvette 10 and whose vertical edges are essentially lower than the cu-
vette 10. Thus the cuvette 10 may be transported from its brackets 24 along the loading
track 38 such that the brackets 24 of the cuvette 10 are placed on top of the vertical edges
of the loading track 38, whereby the lower edges of the positions 20 are at a distance
from the bottom of the loading track 38. The gap between the lower edge of the positions
20 and the bottom of the loading track 38 makes it possible for the lower edge of the po-
sition 20 not to grind the bottom of the loading track 38 and thus preventing scratching.
To the loading track 38 side of the disc 32 a loading funnel 40 has been fitted, through
which cuvettes 10 are loaded into the openings 34 of the disc 32. The loading is per-
formed by using a press 36, the lower edge of which is adapted to press the cuvette 10
into the loading funnel 40, in which it is adapted to acquire a shape allowing it to fit into
the opening 34 and to proceed into the opening 34. The curvature of the opening 34 con-
forms to die curvature of the disc 32. Due to of the elasticity of the cuvette 10, it may be
used with various discs 32 and further openings 34 with different curvature radii. As is
apparent from Fig. 5, the loading funnel 40 is shaped such that a cuvette 10 passing
through it assumes a curved shape able to fit into the opening 34. The cuvette 10 receiv-
ing edge 42 of the loading funnel 40 is convex when viewed from the entering direction
of the cuvette, whereby a cuvette 10 pressed against it bends into a shape conforming to
me perimeter of the disc 32. The curvature of the receiving edge 42 of the loading funnel
40 can be planar, i.e. constant, or it can vary in the horizontal direction, whereby the re-
ceiving edge 42 is planar at its upper edge and progressively convex when viewed lower.
Thus the cuvette 10 is adapted to bend gradually conforming to the receiving edge 42,
whereas the face 42 being evenly curvaceous, the cuvette 10 is adapted to bend imme-
diately to the curve shape desired. The loading funnel 40 is also equipped with brackets
24 with receiving side edges 44, against whose inner edge the brackets 24 are pressed.
Thus, the cuvette 10 is in intensive contact with the loading funnel 40 only at the brack-
ets 24, whereby they receive the wear and scratching resulting from bending. Therefore
the fragile surfaces of the cuvette 10, such as screens 26 and their surroundings, avoid
erosion. Furthermore, the side edges 44 of the loading funnel are equipped with guides
46 securing that the brackets 24 of the cuvette 10 are pressed against the inner faces of
the side edges 44. When the cuvette 10 is pressed against the lower edge of the loading
funnel 40, its brackets 24 are pressed in and the separating walls 22 are bent, whereby the
cuvette 10 is tightly curved against the receiving face 42 of the loading funnel 40 and
ready to be loaded equally tightly in to the opening 34 of the disc 32. With the aid of the
brackets 24 the cuvette 10 is placed and centers itself automatically into the opening 34
even though the disc 32 should not be in the exactly correct position. The cuvette 10 can
certainly have a different construction achieving the qualities described above. For ex-
ample, a cuvette 10 illustrated in Fig. 7 could be a possible embodiment, but only if it
would result in above described qualities. Likewise, the cuvette 10 could also be straight
and not adapted to assume a curved shape, whereby the cuvette 10 would be designed to
remain in a corresponding straight opening 34 only due to the elastic properties of its
brackets.
The path of the press 36 is so long that the upper edge of the cuvette 10 is at a desired
height when it is pressed in to the opening 36. Accordingly, the pressing depth of the
press 36, which may be programmed to suit the application, determines the vertical
alignment As above, the when loading the cuvette 10 into the opening 34 its brackets 24
receive the most abrasion, which the other surfaces avoid. As the cuvette 10 is in the
opening 34 of the incubator 30, the fluid or other substance to be analyzed can be distri-
buted into the sample spaces 28. It is to be noted that the cuvette 10 may be designed for
incubators 30 with discs 32 and further openings 34 of various sizes, as described above.
Thus, a cuvette 10 of a certain size can be used in various applications, which provides
considerably cost savings while the variety of cuvettes is minimal.
The disc 32 is heated for maintaining as favorable analyzing conditions as possible, due
to which heat is conducted to positions 20 and further to sample spaces 28 through the
side face of the opening 34. With the aid of separating walls 22 the positions 20 are sepa-
rated from each other not causing temperature distortion with their preheat between adja-
cent positions 20. An even temperature is further improved by sufficiently prominent
brackets 24, which isolate the outer edges of the outer positions 20 of the cuvette 10 from
the heated faces of the opening 34.
The analyzing apparatuses have been arranged around the incubator 30 such that there is
no need to remove the cuvette 10 from the opening 34 during testing. For example, opti-
cal tests may be performed directly through the screen 26 of the position 20. Therefore,
the position 20 of the cuvette 10 loaded from the loading track 28 into the opening 34 of
the incubator 30 is adapted to receive substances from several manipulators by changing
the position of the disc 32. The analyzing procedure can in this case be arranged such
that the reagent is portioned out into the sample space 28 of the position 20 by means if a
reagent dispenser, which retrieves the substance from a reagent storage. The dispensing
of the reagent requires that the disc 32 of the incubator 30 has been rotated into a correct
position such that the correct position 20 is in a reagent receiving position. The basic idea
of the arrangement is that the sample is moved in the cuvette 10, the position of which is
changed by rotating the disc 32 of the incubator, whereby the number of maneuvers and
directions is as small as possible. The samples for their part are dispensed in a similar
manner by means of a sample dispenser, which retrieves the substance from a sample
storage. The reagent and sample can be mixed by rotating the disc 32 into the vicinity of
a mixer and by starting the mixer. The contents of the position 20 can be analyzed opti-
cally as described above and, for example, with a manipulating analyzer adapted to suck
the sample into its test space and to measure its voltage compared to a reference value.
The sectioning and programming of the test sequences and maneuvers is previously
known.
When the tests performed to all used positions 20 are completed, the cuvette 10 can be
ejected from the opening 34 such that the press 36 having performed the loading pushes
the cuvette 10 out of the opening 34 into a separate receiving bin or into the waste open-
ing 50 of the incubator 30. Alternatively, the press 36 can load a new cuvette 10 through
the loading funnel 40 into the opening 34, whereby the used cuvette 10 is pushed out by
the new one into a separate waste bin or into the waste opening 50 of the incubator 30.
Claims
1. A cuvette (10) for an automatic incubator (30), which cuvette (10) comprises:
-- at least two positions (20), connected by
-- a separating wall (22) the number of which is totally one less than the numbers of
positions (20), and
-- brackets (24),
characterized in that
-- the brackets (24) are in the outermost positions (20), and in that
-- the brackets (24) are adapted to guide the cuvette (10) into a curved shape.
2. A cuvette (10) according to claim 1
characterized in that the brackets (24) are elastically flexible when pressed in.
3. A cuvette (10) according to claim 1 or 2,
characterized in that the separating walls (22) allow the cuvette (10) to bend elas-
tically about its vertical axis.
4. A cuvette (10) according to claim 2 or 3,
characterized in that the separating wall (22) connects parallel positions (20) along
at most half of the side face of the cuvette (10) to improve an even temperature dis-
tribution.
5. A cuvette (10) according to any of the preceding claims,
characterized by its brackets (24) comprising flexible protrusions, which curve
outwards and towards each other from the upper edges of the outer corners of the
outermost position (20), whereby the brackets (24) are adapted to be elastic in the
position orientation direction and to be torsionally rigid in the vertical direction.
6. A cuvette (10) according to any of the preceding claims,
characterized in that the cuvette (10) is made of a material with essentially good
optical and elastic properties, such as acryl.
7. A cuvette (10) according to any of the preceding claims,
characterized in that the cuvette (10) is made of two materials.
8. A cuvette (10) according to claim 7,
characterized in that the materials are mutually different polymers so that the first
material has essentially good optical properties and the second material has essen-
tially good elastic properties.
9. A cuvette (10) according to claim 8,
characterized in that the positions (20) are made of the first material and me sepa-
rating walls (22) or brackets (24) or both are made of the second material.
10. A cuvette (10) according to claim 8 or 9,
characterized in that the first material is acryl.
11. A cuvette (10) according to claim 8,9 or 10,
characterized in that the second material is polyurethane.
12. A handling method of a cuvette,
characterized in
-- transporting the cuvette (10) from its brackets (24) to an incubator (30),
-- bending the cuvette (10) into a curved shape,
-- loading the cuvette (10) into an opening (34) of the incubator (30), in which it
remains by means of its own spring back factor, and
-- removing the cuvette (10) from the opening (34) after the analysis.
13. A handling method of a cuvette according to claim 12,
characterized in removing the old cuvette (10) from the opening (34) by loading
herein a new cuvette (10), which pushes out the old cuvette (10).
14. A handling method of a cuvette according to claim 12,
characterized in removing the old cuvette (10) from the opening (34) by means of
a press (36).

A cuvette (10) for an automatic analyzing apparatus according to the invention comprises at least two positions
(20), for each position pair one separating wall (22) connecting the positions (20), and brackets (24), which are at the outermost
positions (20) and which are adapted to guide the cuvette (10) into a curved shape. In a handling method of a cuvette (10) according
to the invention a cuvette (10) is transported from its brackets (24) to an incubator (30) and bent into a curved shape. In the
method the cuvette (10) is then loaded into an opening (34) of the incubator (30), in which opening (34) it remains by means of its
own spring back factor, until the cuvette (10) is removed from the opening (34) after the analysis.