Note: Descriptions are shown in the official language in which they were submitted.
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Il .1 I ~ACKGROUND OF THE INVENTION
2 1 .
3 ¦ l. Field of the Invention
4 ! - This invention rëlates to an aspirating probe assembly
useful in automated sample analysis and having a device associated
6 ¦ therewith for washing the interior and exterior of the probe
7 when the probe is not immersed in a liquid for aspiration thereof.
8~ 2. Prior art.
91 Heretofore, an aspirating probe has been associated with
10; a sampler for the supply of a series of liquid samples for~
11 analysis seriatum. The samples may be a series of discrete
12 blood serum specimens., each of which is supported and confined
13 in a cup of a series of cups supported on a motor-driven turntable
14 of the sample. The probe has been provided with a support for
15 movement of the probe into the cup then indexed therewith for .
16 aspiration of the sample and then into the liquid within a
17 stationary wash receptacle associated with the sampler for
18 aspiration of wash liquid before the probe enters the next sample .
- 19 cup after movement of the turntable. Between immersions 1n
20 ¦ sample and wash l1quids, the probe has aspirated an immisc1ble
21 fluid such as air and the resultant stream flow1ng from the probe
22 has been segmented by segments of air and wash liquid, which ;
23 segmentation of the sample stream preserves the integrity of ~he~
24 different samples.. The segmentation is such that ~ a wash~liqu~id
segment is. located 1ntermediate each sample and its neighbor and
~26 an air segm~ent is located betwaen each wash l1quid segment and :.
27
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1¦l the adjoining sample as described in de Jong U.S. Patent 3,134,263 .
2¦¦ The probe assembly and sampler o~ Negersmith et al U.S. Patent
3 1¦ 3,266,322 accomplishes the same result des~ribed above but in a
4¦1 different way. In the latter, the stationary wash receptacle
_ 5 1 is disposed above the sample cup indexed with a probe which
6 ~ unlike the probe utilized in the de Jong disclosure has no
7 angular movement on a verticle axis but has a similar up and down
8 motion. The wash receptacle h~s vertically aliyned openings
9 above the sample cup indexed therewith, and the surface tension
10 ¦¦ of the liquid within the receptacle is sufficient to prevent the
11 11 wash solution from escaping through the small lower opening in
12 1 the receptacle into the sample cup. As the prohe leaves the :
13 sample cup, air is aspirated therein until the probe`rises within
`14 the wash receptacle at which time the exterior of the probe is
washed by the surrounding liquid and wash liquid is aspirated
16 into the probe. Subsequently, the probe leaves the liquid in
17 the wash receptacle in its upward movement and again aspirates
18 air. ; `
- 19 In Bannister et al U. S. Patent 3,719,086, a stationary wash
2D ¦ receptacle is provided over the indexed sample receptacle, such
21 as is provided in Negersmith et al. The lower end of the
22 aspirating probe is plugged and the probe has lateral inlet
23 openings therein above the plug for the liquid which it aspira;tes
24 such as a sample, and more specifi~cally, the serum or p1asma~of
a blood sample within a centrifuged sample cup. As in the
26 Negersmith et àl construction, the probe aspirates air in this
:
-, 27 case through the lateral inlets therein, on upward mo~ement of
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1055728
the probe on leaving the sample receptacle to an inter-
mediate position of the probe. On further upward movement
of the probe, the lower end of the probe is retracted to a
position in which the plugged lower end lies below a flushing
chamber in a bore formed in the receptacle and~fluid is
flushed through the chamber around an upper part of the probe
and is aspirated from the chamber into the interior of the
probe through the aforementioned inlet openings which are
then disposed within the chamber. The plugged end of the
probe within the aforementioned bore lies between the afore-
mentioned chamber and a lower scavenging chamber from which
fluid, mostly air, is sucked by a vacuum. It is pointed
out by the patentees that there may be some flow of fluid -
from the chamber through the bore around the plugged section
of the probe to the scavenging chamber. However, it appears
that the bottom of the probe is not fully washed on the
exterior thereof, and this may lead to contamination by
the probe movements of one sample by another.
The aforementioned patents are believed to be typical
of the prior art. It is proposed to overcome the difficulties
with this prior art.
Summar~ of the Invention
The present invention provides a sample analyzer
comprising an aspirating probe element having an inlet
,
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for immersion successively in liquids contained in a series ` `
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of receptacles and for relative retraction to an upper posi- ; -
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- tion prior to immersion in the liquid of ~nother receptacle,
and means flushing a wash solution down the exterior of :- `
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the probe element in the upper position and drawing~off ;~
substantially all the flushed solution through the probe
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inlet. ~ -
A further ob~ect of the invention is to provide a
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probe for aspirating liquid used in automated analysis,
- which has improved wash. Another object is to provide an
aspirating probe which has a travel from a lower position
4 in which it is immersed in the
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liquid in a receptacle for aspiration thereof to an upper
position in which it clears the receptacle, carrying with
it in movements intermediate these positions a washing device
to wash the interior and exterior thereof when in the upper
position. Further objects of the invention will appear
from the following detailed description of the preferred
embodiments of the invention.
BRIEF DESCRIPTION OF THE DRA~INGS
In the drawings:
FIG. 1 is a schematic diagram in fragmentary form
of a portion of a liquid sample analyzer including a sampler
and a probe assembly, embodying the invention;
FIG. 2 is a fragmentary side elevational view,
partially in section, illustrating the probe assembly in
the upper position thereof;
FIG. 3 is a view similar to Fig. 2 and illustrating
the probe immersed in a liquid sample in-a receptaele, for
aspiratin~ such liquid;
FIG. 4, located on the first sheet of drawings,
i9 a diagrammatic view similar to Fig. 1 showing a modified
form of the invention wherein the probe assembly is utilized
for both aspirating and dispensing liquid;
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FIG. 5, located on thè first sheet of drawings,
is a view similar to Fig. 2 illustrating the probe of Fig. 4 -;
in raised position;
FIG. 6 is a view similar to Fig. 3 illustrating
the probe of Fig. 4 in lower position to aspirate liquid
from a container thereof; and
FIG. 7 is a view illustrating the probe of Fig. 4 -
in dispensing condition.
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In Fig. l there is shown a sampler indicated
generally at lO, to supply in this form a series of liquid
samples sequentially for continuous-flow-type analysis.
In the illustrated form, the samples may be a series of
discrete blood serum samples, each of which samples is
supported and confined in a cup 12 of a series of cups
supported on a motor-driven turntable 14 of the sampler.
Associated with the sampler, is a probe assembly, indicated
generally at 16, provided on a vertical support including
a shaft 18 (Fig. 2) for vertical movement G~ the probe
assembly. The turntable 14 of the sampler may be driven
in the manner described in de Jong U. S. Patent 3,134,263,
and the cupport shaft of the probe assembly 16 may be moved
rectilinearly in an up and down direction by the structure
of that patent. However, lnasmuch as the support shaft 18
has no angular movement the cam 80 and cam follower 90 of
that patent are omitted. The turntable 14 is rotated
periodically to ~uccessively present each sample cup 12 to
the probe assembly 16.
As shown in Fig. 2, the probe assembly 16 includes -
a member 20 of C shape having upper and lower horizontally
extending arms provided with coaxial holes therethrough. A
probe tube 24 is fixed in the hole of the upper arm 22 and --
.
extends downwardly a distance through the hole in the lower
arm 26 of the member 20, the tube being part of the probe --
assembly 16. A tubular sheath element ~ ~-
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1 28 of the probe assembly is vertically slideable on the probe
2 tube 24 within limits. Th'e upper end of the element 28 also is
3 closed in fluid-tight relation around the probe tube 24, the
4 s-tructure including a sliding seal and bearing assembly 30. The
~ 5 probe 24 and the sheath 28 define an annular chamber 28 a there-
6 between. -
7 Adjacent the upper end thereof the sheath or tubular element ~ -
8 28 has a tubular lateral inlet 32 connected to the outlet of a
compressible pump.tube 34. The lower end of the sheath element
10 28 is outwardly tapered, as at 36, so as to engage over and agains
11 the mouth of a cup 12 as will appear more fully hereinafter.
12 Downward movement.of the sheath element 28 around the probe 24
13 is limited by a collar 38 fixed to the arm 26, which extends
14 around the sheath and ~n the condition shown in Fig. 2 provides
1 15 an abutment for the lateral tubular inlet 32. At the upper end
16 thereof, the sheath 28 has a lateral extension 40 of the angular
17 configuration shown which cooperates with the actuator 4- of a
18 switch 44. A compression spring 46 embraces the probe tube 24
- 19 and has one end bearing on the-upper arm 22 of the support 20
20 ¦ and the other end thereoP'bearing against the top of the sheath
r 21 element ~8.: The compression spring 46 urges the sheath element ~ ':22 downwardly, 'and it is to be noted that in its fully extended
23 .position of Fig. 2 the bottom of the sheath 28 extends a distance f
24 below the lower~extremity o~ the t~be 24. The upper end of-the
: 25 probe 24 has an.outlet 48 connected to the inlet o~ a compressible
1 26 pump tube 50. - '
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l~)SS728
1 , Turning once again to Fig. l, it can be seen that a pump 52
2 is interposed in the tube 34, the latter having an inlet end 54
3 connected to a non-illustrated source-of wash solution which may
4 bé water. The pump tube 5~ extends through a pump 56 which may
_ S be of the peristaltic type. A compressible pump tube 58 extends
6~ through the pump 56 and has an inlet end 60 connected to a
71 non-illustrated source of a reagent which may be Liebermann-
8 !! Burchard reagent for determination of cholesterol in each of the
9l~ successive blood serum samples analyzed in a non-illustrated~
10~ manner. The outlet end of the tube 58 is connected to the tube 50
11 downstream from the pump 56. A pump tube 62 extends through the
12 pump 56 and has an inlet end 64 open to the atmosphere for
13 conveying air through the pump tube 62. The outlet end of the
, 14 pump tube 62 is connected to the compressible pump tube 58 down- i
j 15 stream of the pump to segment wit'n air the reagent flowing in
t 16 pump tube 58 prior to the latter's introduction into the flowing
17 stream in pump tube 50 which directs the treated stream therein !
18 to analysis. ~ ;
19 ~ It is to be noted that in-the condition of probe assembly 16
20 illustrated in Fig.-2, the probe assembly is in its raised
21 position on the shaft l8 and iA a position to be lowered toward
22 the indexed sample cup associated therewith. In this condition
23 the pump 54 i9 operative to pump wash solution through the ir.let
~,
24 32 in the sheath 28 to fiI1 the anpular chamber 28 a def1ned .
~- 25 between the tube 24 and the sheath 28, with~;the flow in such
26 chamber being in a downward direction around the tube 24. When
27 such flow of wash solution reaches the lower end~of the tube 24
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1I within th~ sheath, the suc-tion at the inlet end of the tube 24
2 is sufficient to draw the entire volume of such flow in the
3 chamber 28 a, together with some air drawn through the open lower
4 end of the sheath 28, into the tube 24 and upwardly therein
through the outlet 48 of the tube 24 into the tube 50 under the
6 influence of the pump 56. This washes the exterior of the tube
7 24 to prevent contamination. The stream of wash liquid flowing in~
8 the probe tube 24 and the tube 50 cleanses the-interior of such
9 tubing such as the tubing 24, 50 and the non-illustrated tubing
downstream thereof in the analyzer.
11 As the probe assembly 15 moves downwardly with the shaft 18
12 from the position of Fig. 2, the lower end of the outwardly
13 tapered sheath engages the cup 12 therebeneath forcing the sheath ¦
14 28 upwardIy against thë force of the spring 46, and in so doing
the projection 40 of the sheath trips the actuator 42 of the
16 switch 44 which stops the pump 54 and hence the flow of wash
17 liquid through the probe assembly. Any remaining wash solution
18 in the sheath is aspirated by the tube 24. Subsequently, as tube I
19 24 continues downwardly relatively to the sheath 28 air is
aspirated into the tube 24 to later form an air segment therein.
21 Preferably, no air-tight Fonnection exists between the sheath 28
22 and the cup 12. As-the relative movement of the tube 24 and-the
23 sheath 28 is continued in this direction, the tube 24 enters ~the
24 liquid in the cup 12 and commences~to aspirate the sample~liquid. I
25 When sufficient sample has been aspirated in this~manner, the -
26 shaft 18 rises carrying with~it the probe support in the form of
the member 20 of C shape which carries the tube 24 upwardly
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.relativel~ to the sheath 28. As the lower inlet end of the tube
!2 24, indicated at 24 a, cle'ars any remaining liquid in the sample
3 cup 12 moving relatively to the sheath 28 and prior to any
4¦ movement of the latter in an upward direction, the tube 24
5¦ aspirates air which.later fo:rms an air segment in the stream in
6 the probe assembly and in the pump tube 50. As the upward move- ',
7 ment of the tube 24 travels to return to the position of Fig..2
8 the projection 40 of the sheath trips the actuator 42 of the
9 switch 44 thereby commencing operation of the pump 52 to once ¦
again introduce wash solution to the inlet 32 to ~irst wash away
11 the vestiges of the last sample on the exterior of the probe tube I
12 2~, and then flow upwàrdly in the probe 2~ to cleanse the interior !
13 of the latter. As the support member 20 rises with the shaft 18,
14 the sprin~ 46 retains the sheath 28 engaged with the cup 12 until
the collar 38 of the member 20 engages the tubular fluid inlet 32
16 and thereafter lifts the sheath 28 bodily with the tube 24 so
:17 that the former clears the cup 12. The pump 52 continues to : ;
' 18 operate and the wash solution continues to be supplied, while the ¦
-....... turntable 14 of the sample has been rotated to lndex the next
sample cup lZ with respect to the probe, until the probe assemb-ly ¦ -
21 16 has descended sufficiently for the cycle to be repeated as the !
22 sheath 36 engages the last-mentioned cup 12 and is~displaced.
23 upwardly thereby, once again actuating the switch and::thereby
24 terminating operation of the pump 52 and permitting air to b.e
,~ 'aspirated upwardly in the tube 24 prior to entry'of the 1atter
26 into the liquid in the last-mentioned cup 12.~ :
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I In the aspirator-dispenser modification of the invention
2 shown in Fig 4-7, like numerals identify like parts. The
3 sampler indicated generally at 70 (Fig. 4) is in all respects
4 o~her than the probe assembly similar to the sampler 10 for
¦ delivery successively of a series of, say, blood serum samples,
61 excep-t that unllke the sampler lO`the shaft 18 (Fig. 5) supporting
7 the pro~e assembly, indicated generally at 72, has an angular
8 movement as well as an up and down movement as described in the
9 aforementioned de Jong U. S. patent 3,134,263. The construction
and arrangement is such that when the probe assembly supported by
11 the shaft 18 is in the upper condition of Fig. 5 after aspirating
12 a-sample it may thereafter swing on the axis o~ the shaft 18 to a
13 position to dispense the sample or a portion thereof to an indexed
14 one of a series of sample-receiving receptacles 74 supported in a
movable tray 76 for indexing movement in a conventional manner
16 in the direction of an arrow Fig. 4;
17 The probe assembly 72 is like the previously dascribed probe
18 assembly in all respects except that it has an added element ln
19 the form of a solenoid-operated latch 78 supported on the vertical
20 ¦ leg of the support member 20 a distance above the switch 44.: The
21 solenoid operated latch 78 may be energized to a latched position
22 thereof and may be alternately energized for retraction of the
23 latch. The operation o~the probe assembly is identlcal~to that
24 of the probe~assembly 16 previous~y described except that as~-the
probe as~embly descends on a sample cup 12 and the sheath 28 is
26 ;deflected upwardly by the last-mentioned cup for~aspiratlon of
27 the sample as shown in Fig. 6, the latch 78 is operated to latch
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the sheath in its relatively retracted position of Fig. 6
by engagement of the latch with the lateral projection 40
on the sheath 28.
Turning again to Fig. 4, a timer may be provided
as sho~n which has an output to the input of a cable 80
which has an output to the solenoid-operated latch 78 to
effect extension and retraction of the latch 78. The timer
also has an output to an input of a cable 82 which has an
output to the sampler controlling the indexing of the turn
table 14 to successively index sample cups 12 with the
probe assembly 72 and also to control the movements of the
probe assembly 72. As shown in Fig. 5, the outlet 48 of `
the tube 24 is coupled to the inlet of a tube 84 and a
; reversible pump 86 is interposed in the tube 84. The tube
84 has an outlet to waste. The timer has an output to an
input of a cable 88 having an output to the pump 86 to
activate the latter periodically in one direction or the
other.
When the probe assembly 72 is in the condition
of Fig. 5 and about to move downwardly with the shaft 18
toward the sample delivery cup 12 spaced therebelow the -
probe assembly is in the afore-mentioned wash mode and the
pump 52 is energized to supply wash solution to the probe
inlet 32 throùgh the pump tube 34~ The wash solution f lowing
around the lower portion of the tube 24 is sucked upwardly
~ through ~he lower inlet 24a of the tube 24 to wash the
interior of the tube 24 as well, and is directed by the~tube
24 into the tube 84 which delivers the wash liquid to waste
through the outlet of the last-~entioned tube. The last-
mentioned position of the probe assembly 72 is a rest position.
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~ hen the probe assembly 72 moves from the position
of Fig. 5 to the position of Fig. 6 in which the tube 24,
after first aspirating air following the wash liquid,
aspirates the liquid in the sample-receiving cup 12, which
movement deflects the sheath upwardly, the timer actuates
latch 78 to extend it to the latched position of Fig. 6.
At this time, the aspirated sampLe has filled the tube 84
a distance short of the pump 86. When the probe assembly
72 returns to the upper position so that the assembly
clears the receptacle 12, the sheath remains latched and
continues in this latched condition while the shaft 18
swings the probe assembly to the position of Fig. 7. It
is to be understood that prior to this bodily upward move-
ment and subsequent swinging movement of the probe assembly
72, the pump 52 is deenergized by actuation of the swi~ch
44 and the pump 86 is deenergized by the tiner. A~ter the
probe assembly 72 has reached the angular position of Fi~. 7
above the indexed sample-receiving cup 74 in the tray 76,
the timer energize9 the pump 86 in the reverse direction to
dispense all or a portion of the sample in the tubes 84, 24
through the probe assembly into the sample-receiving cup 7
spaced below the probe assembly. Thereafter, the probe
- assembly 72 under the control of the timer begins its return
travel toward the position of ~'ig. 5 and during thls return
the timer retracts the latch 78 so that the tube 24 and th~e
sheath 28 assume the relative positions one to the other ~ -
shown in Fig. 5 which once again places the probe assembly
in the wash mode. It is to be understood that as the~probe ~
assembly is placed in the wash mode, the pump 86 ~-
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1 is reversed by the timer to aspirate fluid through the tube 24.
2 During this period the turntable 14 and the tray 76 are moved to
3 move up into indexed pOSitiOIl the next following sample-delivery
41 cup 12 and sample-receivinq cup 74. The wash solution is _
~ S directed to waste through the tube 84 as the next cycle starts~
6 washing away the vestiges in the tube 84 of the last sample.
7 While in the illustrated forms there has been shown and described
8 means to relatively index the probe assembly with.successive
9 liquid receptacles, it is to be understood the invention does
10¦ not require this.means such as the sampler, as the liquid .
11! receptacles may be presented to the probe assembly of the
12 ¦ invention manually. In such an embodiment, the user lifts the
13 liquid receptacle under the probe assembly so as to engage the
14 mouth of the receptacle with the open lower end of the probe
15 sheath 28 and deflect the sheath upwardly so that the probe ..
16 extends into the liquid within the receptacle for aspiratron of
17 such liquid. Further, rn such an embodiment the probe 24 need
18 not have any vertical movement. In addition, it will be apparent
- - 19 that the invention also contemplates an arrangement wherein a
liquid receptacle is raised mechanically to:deflect the probe
21 sheath 28 upwardly and achieve on such movement:immersion of
22 the probe .into the liquid in the receptacle. ; -.
23 While plural forms of the liquid aspirating probe assembl~t
24 of a sample analyzer hav@ been illustrated and described, it will
25- be apparent, especially to those versed in the art, that in.vention
26 may.take other forms and is susceptlble of various changes of
27 details without departing from.the principles of the invention.
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