Note: Descriptions are shown in the official language in which they were submitted.
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COMPACT ANALYZER
FIELD OF THE INVENTION
This inventicn relates generally to an
analyzer for detecting quantities of analytes in
5 liquids. More specifically, it relates to such an
analyzer constructed to be compact for ease in port-
ability.
BACKGROUND OF THE INVENTION
The trend in the field of dry chemistry blood
10 analysis is towards smaller instruments, for use by
smaller institutions and individu~ls, e.g., doctor's
offices. This is evident from the fact that early,
commercial dry chemistry analyzers were large machines
designed for the large hospital or clinical labor-
15 atory, as shown, for example, in U.S. Patent No.4,287tl55, issued September 1, 1981. (As used herein,
"dry chemistry" refers to tests wherein there are no
liquid reagents stored for use, such tests having been
made possible by test elements of the type described
20 in, e.g., U.S. Patent No. 3,922,158, issued November
16, 1976.) More recently, the analyzers have baen
reduced in size, complexity and cost, so as to be use-
f~ll in doctor's offices, e.g., as shown in U.S. Patent
Nos. 4,303,611 and 4,424,191.
Although such reductions have greatly
increased the versatility of the dry chemistry analy-
sis technology, further reduction could provide the
additional advantages of portability and use by other
than highly skilled doctors and their assistants.
One of the problems that the prior art had
not overcome, prior to this invention, concerning
portability, is the height of the analyzer neces-
sitated by the presence of the d~spensing station used
with a pipette. That is, as shown for example in the
35 aforesaid '191 patent, the analyzer has included a
station for supporting a pipette removably positioned
-2-
above a test element. A support for the pipette
avoids dispensing errors that can occur without a
support. The support for such ~ositioning of the
pipette has necessitated that the analyzer have
5 considerable height extending above the real working
plane of the analyzer, namely, the plane of the test
element. Such height makes the analyzer quite bulky,
and thus less portable, than it would be without the
height required for the dispensing station. Yet, it
lO has not been desirable to do away with the dispensing
station since best results are achieved if incubation
oE the test element occurs immediately, and in a
controlled environment, following dispensing with a
pipette. That is, a full function analyzer is
15 desired. Such is not readily achieved if dispensing
is done on a different apparatus than on the analyzer.
S~MMAR~ OF THE INVENTION
There is provided an analyzer that overcomes
the port~bility problems of prior art analyzers noted
20 above.
More specifically, there is provided an
analyzer including a dispensing station and means for
detecting a colorimetric or a potentiometric change in
a test element on which a test liquid is dispensed at
25 the dispensing station, the dispensing station includ-
ing a pipette support for orienting a pipette to dis-
pense such liquid at the dispensing station. The
analyzer i6 improved in that it further includes means
for movingly connecting the pipette support to the
30 analyzer to permit the support to move into and out of
an operative position associated with the dispensing
station, and out of and into, respectively, a with-
drawn position removed from the dispensing station,
the withdrawn position being constructed to minimize
35 the height of the analyzer.
Accordingly, it is an advantageous feature of
the invention that a full functio~, dry chemistry
analyzer is provided that is portable because its
total height iB reducible when not in useO
It is a related advantageous fe ture of the
invention ~hat such an analyzer provides for both the
5 liquid-dispensing function using a pipette, and
compactness when not in use.
Yet another advantageous feature of the
invention i8 that such an analyzer allows the same
dual pipette to be used for dispensing liquid onto a
10 colorimetric test element as is used fsr dispenslng
liquid onto a potentiometric test element.
Other advantageous features will become
apparent upon reference to the discussion of the pre-
ferred embodiments, when read in light of the attached
15 drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is an isometric view of an analyzer
constructed in accordance with the invention;
Fig. 2 is an elevational view, partially in
20 section, taken vertically and generally along ~he
plane II-II of Fig. l;
Fi&. 3 is a fragmentary section view similar
to that of Fig. 2, except taken generally along the
vertical plane III-III of Fig. l;
Fig. 4 is a fragmentary sectional view taken
generally along the plane IV-IV of Fig. l;
Fig. 5 is a fragmentary sectional view simi-
lar to that of Fig. 2;
Fig. 6 i6 a isometric view similar to that of
30 Fig. 1, except with the pipette supports in their
withdrawn positions; and
Fig. 7 is an isometric vie~ of another embod-
iment o the invention.
BRIEF DESCRIPTION OF THE INV~NTION
The invention is particularly described in
connection with preferred embodiments, wherein both
colorimetric and potentiometric test capability are
provided, with independent pipette support for each of
such tests. Additionally, the preferred embodim~-lt
features the testing of biological liquids. In
5 addition, the invention is also applicable to an
analyzer having only one of the colorimetric and
potentiometric testing capability, or even some other
kind of testing capability, so long as a dispensing
station is provided. It is also applicable regardless
10 of the type of liquid being tested, particularly since
the compactness of the analyzer makes it attractive
for ield testing of industrial liquids such as waste
water, and the like.
As in conventional full-function analyzers,
15 an analyzer 10 constructed in accordance with the
invention, Fig. 1, is adapted for use with a pipette
12, and comprises a first movable support 20 for a
first test element; a second movable support 22 for a
second test element; an aspirating station 30 for
20 loading the pipette with test sample liquid, and
optionall~, with a reference liquid; an input keyboard
40; a transitory display device 42; and a permanent
record display device 44. Keyboard 40 and display
devices 42 and 44 are conventional, e.g., device 42 is
25 a 16 character by 4 line liquid crystal display and
device 44 is a thermal dot matrix printer.
Any pipette 12 is satisfactory, provided it
is dimensioned to fit the pipette support hereinafter
described in detail. Preferably it uses disposable
30 tips. Actuating button 14 drives the piston of the
pipette, whereas button 16 is used to eject used dis-
posable tips.
Supports 20 and 22 each comprise, Fig. 2 and
3, a pusher blade 24 having a pocket 25 that receives
35 one of the test elements E or E'. A handle 27 is pro-
vided on the blade for ease in manipulation. The
blade reciprocates on surfaces 28, 29. Most pref-
erably, element E is constructed in the manner of the
elements described in U.S. Patent No. 4,258,001,
issued on March 24, 1981, or the aforesaid U.S. Patent
S No. 3,992,158, e.g., to analyze for glucose.
Aspirating station 30, Fig. 1, comprises a
pipette mount aperture 32 in the frame 34 of ~he
analyzer, and a pivotable support arm 36 mounted in
opening 37, to hold trays 38 and 39. Tray 38 is
10 loaded with the sample liquid to be analyzed and tray
39 is loaded with a reference fluid when a potentio-
metric measurement is to be made. Aperture 32 extends
all the way to opening 37.
Frame 34 provides an overall top surface 35
15 of the analyzer which is reduced in height. That is,
the overall height of the analyzer, not counting sup-
ports 100 and 102 when in use as described below, can
be as little as 8 cm.
Read stations 50 and 50' are provlded for
20 detecting the reaction that takes place in each of
elements E and El. Station 50, Fig. 2, is a colori-
metric detection station, comprising a reflectometer
for detecting reflection densities. The details of
the reflectometer are conventional, and can be adapted
25 from a variety of techniques. Preferably, at least
one LED 52 is disposed to illuminate element E through
a transparent member 54, along arrow 56. A small
mirror 58 ls positioned to reflect a sideways-directed
portion of the LED light, arrow 60, to a reference
30 detector 62. A larger mirror 64 is used to reflect,
via arrows 66, diffusely reflected radiation from ele-
ment E to detector 68.
A hold-down pad 70 preferably is used to bias
element E against transparent member 54. Pad 70 com-
35 prises a non-scratching, non-absorbent cover 72, com-
prising, for example, Teflon~ coated aluminum,
mounted on frame 74, and a conventional heating ele-
ment 76. Frame 74 is backed up by a resilient layer 78
that allows pad 70 to move vertically when an element
E is pushed into place for detection. Pad 70 also
serves to prevent evaporation and/or gas leakage from
element E.
A white reference surface in movable support
24 allows the system to take reference op~ical
measurements when the element is in the metering
station.
Optionally, a conventional bar code reader 80
i8 included above blade 24.
Read station 50', Fig. 3, is used to detect
changes in e.lement E' created by ionic analytes. Most
preferably, element E' is constructed in the manner
described in U.S. Patent Nos. 4,053,381, issued on
October 11, 1977, and 4,214,968, issued on July 29,
1980.
Station 50' preferably comprises a heater
platen 76' and a vertically movable arm 82 that mounts
a cover 84 and electrode contacts 86. The cover is
designed to fit over the spotting holes of element El
to prevent evaporation. 8Oth cover 84 and contacts 86
raise and lower in response to the pivoting of arm 82
about pivot point 88. Arm 82 is biased downwardly by
spring 90, and latch 92 is provided to hold arm 82
with cover and contacts raised, when element E' is
moved in and out of position. That is, latch 92
pivots at g~ to clamp onto end 9S of arm 82, except
when end 96 of blade 25 pushes against the latch on
the completion of ~ts inward stroke. A cam shoulder
97 is mounted on blade end 96 to cooperate with cam
follower 98 hanging from arm 82. That is, when blade
25 starts its return stroke to pull out element E'
after reading, cam shoulder 97 forces arm 82 to rotate
clockwise until it again latches with latch 92.
r3L~ 7
Conventional circuitry, not shown, carries
signals from contacts 86 to the rest of the analyzer.
Optionally, a bar code reader 80' is disposed
below blade 25 at station 50', to read bar codes on
the underneath surface of element E'.
As best shown in Fig. 3, frame 34 is provided
at each station 50 and 50' with pairs of apertures 101
aligned with aperture 108, to accommodate the twin
disposable tips of the pipette when the latter is
mounted in the pipette support.
All the signals generated by the analyzer are
processed by a conventional microprocessor, not shown,
using conventional programming. The input from the
keyboard 40, as well as the output on the displays,
are received and directed, respectively, by such
microprocessor, as is conventional.
In accordance with one aspect of the inven~
tion, pipette supports 100, 102 are movably connected
to frame 34, so that they are movable into and out of
an operative position, shown in Fig. 2, associated
with dispensing station 103, Fig. 5, and out of and
into, respectively, an inoperative withdrawn position,
shown in phantom in Fig. 2. ~uch supports comprise,
Figs. 2-4, a yoke 104 connected to the frame via an
arm 106. Each yoke is fixed to one end 107 of arm 106
and is provided with a pipette mounting aperture 108.
Aperture 108 is configured to accommodate the
dispensing end of pipette 12 up to collar 13 of the
pipette, Fig. 1. A keyway 110 is preferably formed in
aperture 108 to cooperate with key ridge 112 formed in
collar 13, to insure the pipette is properly angularly
positioned about an axis 111 or 111', Figs. 2 and 3.
The opposite end 114, Fig. 4, of arm 106 is
~ournalled to frame 34 on axis 116 to allow the arm to
rotate between the operative position shown in solid
~ ~z~
-8- ;
lines, Figs. 2-4, and the withdrawn position shown in
dashed lines of Fig. 2.
The two supports 100 and 102 are mirror
images of each other, except as follows: Support 100
is constructed to assist in the dispensing of liquid
onto a colorimetric element E, Fig. 2, whereas support
102 is constructed to assist in the dispensing of
liquid onto a potentiometric test element E', Figs. 3
and 4. In addition, to allow the same dual pipette 12
(having twin disposable tips) to be used for either
element E or E', aperture 108 in support 100 pref-
erably is displaced sideways a sufficient distance
from the centerline of element E, so as to ensure that
only the disposable tip containing sample liquid,
lines up with the test element. (The dispensing posi-
tion of element E in dispensing station 103, relative
to support 100, is shown in Fig. S, wherein blade 24
is pulled farther out of the analyzer than in Fig. 2.)
Optionally, a portion of yoke 104 can include
a conventional sensor (not shown) to sense the move-
ment of the pipette piston that is indicative of a
dispensing event. Examples of such a sensor include a
reed switch and a Hall effect switch.
To hold the pipette supports preferably in
their upright, operative positions, a latch 120 is
provided, Fig. 4, for the arms of each support. The
latch comprises a lever 123 ~ournalled at 124 to frame
34, and a spring 126 biasing end 128 of the latch so
as to snap end 128 into end 114 of arm 106 at a notch
130. When the opposite end 132 of lever 122 is pushed
against spring 126, latch 120 releases from arm 106,
and the support can be rotated down, arrow 122, Fig.
2, into its withdrawn position.
Preferably, a cavity 140 is provided in frame
34 of the analyzer, Fig. 1. Cavity 140 has sufficient
depth to store the entire yoke 104 of each support 100
- 9 -
and 102, so ~hat the yokes do not pro~ec~ above top
surface 35 of the analyzer, Figs. 2 and 6. Thus, when
the analyzer is not in use, it is very compact and
readily portable.
It is not necessary that supports 100 and 102
be separately mounted on individual arms 106. Alter-
natively, as shown in Fig. 7, th~y can be mounted on a
single arm. Parts similar to those previously
described have the same reference numeral, to which
the distinguishing suffix "a" is appended.
Thus, analyzer lOa includes, as in the pre-
vious embodiment, movable supports 20a and 22a for
colorimetric and potentiometric, respectively, test
elements E and E'. Aspirating station 30a functions
as before, as do keyboard 40a and display devices 42a
and 44a. Also, yokes 104a of pipette supports lOOa
and 102a function as before to provide support during
dispensing of liquid from the pipette shown in ~he
previous embodiment.
Unlike the previous embodiment, yokes 104a
are mounted on a single arm 106a that swings about a
pivot point 116a. Underneath surface 200 of arm 106a
abuts against surface 235 of analyzer lOa so as to
hold yokes ~04a spaced above the analyzer, permitting
elements E and E' to slide into place for dispensing.
When the anal~æer is to be stored or carried, arm 106a
is rotated, arrow 237, out of its solid line position
and into the dotted line position, so that the bottom
surfaces 240 of yokes 104a are at or below the top
surface 35a of the analyzer.
The invention has been described in detail
with particular reference to preferred embodiments
thereof, but it will be understood that variations and
modifications can be effected within the spirit and
scope of the invention.
