Liquid flow viewing cell and method for analyzing liquid stream

The invention is for a method for analyzing a stream of liquid such as blood and apparatus for carrying out the method. While it is known to present a moving column of liquid in a viewing cell, control of the circumference of the column to control its field size and lighting the column from the end opposite the viewing end has not been accomplished. The invention involves the method of passing a first liquid in a column in a confined space to a transparent panel, introducing one or more liquids of different colors to form a hollow column exterior of the first column, exhausting the liquids from adjacent the panel, directing light upwardly at the lower ends and through the columns and varying the pressure of one or more of the liquids to vary the circumference and speed of the first column. Apparatus is provided to carry out the method.

TECHNICAL FIELD 
This invention is in the field of analyzing particles in streams of liquid. 
BACKGROUND OF PRIOR ART 
It is known in the prior art to present an upwardly flowing column of 
liquid in a cell which has a transparent cover over the column permitting 
the viewing of the column. Light has been directed downwardly into the 
column to facilitate viewing. Viewing with a microscope by an observer and 
viewing with devices for counting particles, measuring particle sizes and 
measuring dye content in particles is well known. Reference may be had to 
Pulse Cytophotometer 1CP 11 by Phywe Ag, D-3400, Gottingen, West Germany. 
The heretofore known cells have presented a column of liquid which has a 
fixed diameter without any way to adjust the optimum diameter of the 
column for the instrument used in viewing the column in the cell. Further, 
lighting the column of liquid from the viewing end of the cell provides 
inadequate lighting. 
BRIEF SUMMARY OF THE INVENTION 
A liquid flow viewing cell has a body having a main passageway with opposed 
ends terminating within the body. A first supply passageway is connected 
adjacent to one end of the main passageway and an exhaust passageway is 
connected adjacent to the other end of the main passageway. At least a 
second supply passageway is connected to the main passageway at a point 
between the connections of the supply and exhaust passageways to the main 
passageway. The body is transparent opposite the ends of the main 
passageway. A light adjacent one end of the main passageway is directed 
towards the other viewing end of the passageway. A system supplies liquids 
to each of the supply passageways at predetermined pressures to move the 
liquids through the main passageway and the exhaust passageway. 
In the method of the invention for presenting a stream of liquid for 
viewing, a first liquid to be viewed is passed upwardly in a first column 
in a confined space to a transparent panel through which the column can be 
viewed. A second liquid of a color differing from the color of the fist 
liquid is introduced into the confined space to form a second upwardly 
moving column exterior of the first column. A discharge system carries off 
the first and second liquids from underneath the viewing panel. Light is 
directed upwardly at the lower end of the columns of liquid towards the 
transparent panel. The pressure of one or more of the liquids is varied to 
vary the diameter of the first column of liquid. If desired, a third 
liquid may be introduced into the confined space at a point opposite the 
point of introduction of the second liquid. The color of the third liquid 
may be the same as the color of the second liquid or may differ in color 
from both the first and second liquids. 
The apparatus and method of the invention overcome the problem of the prior 
art of having a column of liquid which cannot be accommodated to the field 
of a viewing device since by varying the relative pressures of the liquid 
to be viewed and an additional liquid surrounding the liquid to be viewed, 
the diameter of the liquid to be viewed can be varied. Further, the 
apparatus and method of the invention provide for the introduction of 
light at the end of the column opposite to the viewing end which provides 
far superior illumination to that provided by the prior art.

DETAILED DESCRIPTION 
Referring to FIG. 1, a microscope 2 has a slide support 4 through which 
light is directed upwardly from a light source indicated at 6. The height 
of support 4 is adjusted by knob 7. Microscope 2 has eye pieces indicated 
at 8 and 10 and an objective lens system indicated at 12. A strobed 
vidicon indicated at 14 is mounted on microscope 2 for determination of 
the size of particles in a liquid being examined. All this apparatus is 
well known to the art and hence need not be detailed further here. 
Adverting now to the invention, a liquid flow viewing cell 22 is shown 
mounted on slide support 4 in FIG. 1. Cell 22 is formed from a series of 
stacked plates (FIG. 3) including base plate 24, intermediate plates 26, 
28, 30, 32, 34, 36, 38, 40 and 42 and top plate 44. Base plate 24 has 
secured thereto upstanding locating posts 50, 52, 54 and 56. Plates 26, 
28, 30, 36, 42 and 44, each have an opening 58 in registry with post 50, 
an opening 60 in registry with post 52, an opening 62 in registry with 
post 54, and an opening 64 in registry with post 56. Plate 34 has openings 
58 and 62 in registry with posts 50 and 54 while plate 32 has openings 60 
and 64 in registry with posts 52 and 56, respectively. Plate 36 has 
openings 58 and 60 in registry with posts 50 and 52, respectively, and 
plate 38 has openings 62 and 64 in registry with posts 54 and 56, 
respectively. 
Plate 24 has eight threaded openings 70 each for the reception of a machine 
screw 72. The portions of the other plates overlying one of the openings 
70 in base plate 24 has a corresponding opening 74 in registry therewith 
to accommodate a screw 72. The upper ends of opening 74 in plate 44 are 
enlarged as indicated at 78 to recess the heads 80 of screw 72. 
Base plate 24 has a central opening 82 for the passage of light and top 
plate 44 has a central viewing opening 84. Plate 28 has a side entering 
slot 88. Plates 32 and 34 have opposed central cutout portions 90 and 92, 
respectively, while plates 38 and 40 similarly have opposed central cutout 
portions 94 and 96, respectively. Plates 30 and 36 have central openings 
100 and 102, respectively. 
The above-discussed plates can be made from a wide variety of materials, 
for example metals such as brass, or a plastic such as an acrylic, for 
example methyl methylacrylate, a polyalkylene resin such as polyethylene 
or polypropylene, glass or quartz. 
When base plate 24 and top plate 44 are made from a transparent material, 
the viewing openings 82 and 84 and plates 26 and 42 are unnecessary. It is 
required that plates 26 and 42 be formed of a transparent material, for 
example, glass or a plastic when plates 24 and 44 are opaque with viewing 
openings 82, 84. 
The cell plates are assembled by stacking them in the order shown in FIG. 3 
with pins 50, 52, 54 and 56, respectively, passing through openings 58, 
60, 62 and 64 of the plates above base plate 24 to cause all of these 
plates to be accurately aligned so that the openings 74 are in registry 
with their respective openings 70 and so that the centers of openings 82, 
100, 102 and 84 are aligned with each other and with the inner end of slot 
88 and so that cutout portions 90, 92, 94 and 96 are properly aligned with 
openings 100 and 102 and with the plates 32 and 34 spaced the desired 
distance apart and the plates 38 and 40 spaced the desired distance apart. 
With the plates thus stacked, screws 72 are passed down through opening 74 
and are threaded into opening 70 to tightly clamp all of the plates 
together. 
As best seen in FIG. 5, a main vertical passage 122 is formed by opening 
100, cutout portion 92 of plate 34 and cutout portion 90 of plate 32 (not 
shown in FIG. 5), opening 102 in plate 36 and cutout portions 94 and 96 of 
plates 38 and 40, respectively. A supply passage 124 for supplying liquid 
to passage 122 is formed by virtue of slot 88 in plate 28 being clamped 
between plates 26 and 30. A pair of opposed supply passageways 126 and 128 
for supplying liquid to the main passageway 122 are formed by spaced apart 
plates 34 and 32 (not shown in FIG. 5) and the adjoining plates 30 and 36. 
A discharge passageway 130 is formed by spaced apart plates 38 and 40 and 
the adjoining plates 36 and 42. Similarly, an exhaust passageway 132 as 
best seen in FIG. 4, is formed by spaced apart plates 38 and 40 and the 
adjoining plates 36 and 42. 
An elevated container 150 (FIG. 1) has its lower end connected to a 
flexible tube 152 which in turn is connected by a pressed fit to a female 
connecting member 154 (FIG. 4) secured to a tube 156 which is in turn 
secured by a pressed fit in passage 124 (FIG. 5) of cell 22. An elevated 
container 160 has its lower end connected to a flexible tube 162 which is 
connected by a pressed fit to a female connecting member 164 which is 
secured to a tube 166 connected by a pressed fit in passageway 128 (FIG. 
5). An elevated container 170 has its lower end connected to a flexible 
tube 172 which in turn is connected to a female connecting member 174 
which is secured to a tube 176 which in turn is secured by a pressed fit 
in passageway 126. Each of flexible tubes 152, 162 and 172 passes through 
a clamp 182 (FIGS. 1 and 2) having a clamping plate 184 through which 
passes a headed machine screw 186 which is threaded to a clamping bar 188 
mounted on microscope 2. 
A tube 200 is connected into passage 130 by a pressed fit and secured to a 
female fitting 204 which receives a flexible tube 206 by a pressed fit. 
Tube 206 passes through a guide 208 mounted on a waste bottle 210 into 
which tube 206 discharges. A tube 214 is connected into passage 132 by a 
pressed fit and in turn is secured to a female fitting 216 to which a 
flexible tube 218 is secured by a pressed fit. Tube 218 passes through 
guide 208 and discharges into waste bottle 210. 
OPERATION 
In operation, a test liquid 230 which for example is a clear liquid such as 
water containing particles of polystyrene is placed in bottle 150. A red 
liquid 232, for example, F D & C Red No. 2 in water is placed in bottle 
160 and a blue liquid 234, for example, F D & C Blue No. 2 in water is 
placed in container 170. Lines 154, 164, 174, 200 and 214 are connected to 
cell 22. With light source 6 energized, cell 22 is centered on support 4. 
All the clamps 182 are in the closed position preventing flow into cell 22 
through lines 152, 162 and 172. The clamp 182 controlling line 152 is 
opened permitting liquid 230 to flow through lines 152 and 156 into 
passage 124 and thence through passage 122 into chamber 129 and thence 
through passage 130 to tube 200 and tube 206 and through passage 132 to 
tubes 214 and 218 into waste bottle 210. With the light energized, 
platform 4 is adjusted to the proper height to maximize viewing liquid 230 
as it discharges from passage 122 into chamber 129. The clamps 182 
controlling lines 162 and 172 are now opened to cause the red liquid 232 
to flow into tube 166 and passage 128 and thence into passage 122, and to 
cause the blue liquid 234 to flow into tube 176 and passage 126 and thence 
into passage 122. As best seen in FIG. 6, liquid 232 and liquid 234 
together form a column of liquid surrounding liquid 230. By adjusting 
clamps 182 and hence the pressure of the liquids in passage 122, the 
diameter of the upwardly moving column of liquid 230 can be varied to make 
it the optimum size for the microscope 2. For example, by increasing the 
pressure in line 152 by opening up its associated clamp 182, or by 
reducing the pressure in lines 162 and 172, the diameter of the liquid 230 
in passage 122 can be increased as shown in FIG. 7. The rate of flow is 
controlled in a like manner to control the time the particles remain in 
the viewing area of the microscope. 
The color contrast provided by the particle free liquids 232 and 234 
greatly facilitates viewing the liquid through the microscope eye pieces 8 
and 10. Further, by way of illustration, the size of the particles in the 
test liquid can be determined by activating the strobe vidicon 14. Other 
associated equipment may be employed such as a photomultiplier for 
counting particles. 
It will be appreciated that the flow through main passageway 122 can be 
reversed by introducing the test liquid into chamber 129 and discharging 
through passageway 88. Positive or negative pressure pumping can be used 
instead of gravity flow with the cell 22. 
It will be understood that the above description is exemplary and is not 
intending to be limiting.