Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to devices for the exami-
nation of liquid specimens; and more particularly relates
to a novel and improved specimen slide adapted to receive
and retain samples of blood, urine and the like for obser-
vation and evaluation using a microscope or other optical
instrument~
In the ield of medicine and biological sciences,
it is desirable to perform qualitative analysis of certain
substances with speed and accuracy. When the subject spe-
cimen is a liquid, such as, blood or urine, examination isoften undertaken by isolating and fixing a small amount of
the substance on a transparent plate for viewing through a
lighted optical instrument, such as, a microscope. This
procedure is especially suited for the observation and eva-
luation of particulate matter in the specimen; for
instance, estimation of sedin~ent in urine or enumeration of
red blood cells. Accordingly, it is important that the
liquid be spread into a very thin layer of uniform depth.
An early approach to "wet mount" examination of specimens,
still very much in use today, involves depositing a drop of
the liquid onto a smooth, transparent plate of glass or
plastic. A thin cover slip is then placed over the plate
to protect and retain the specimen and distribute it as a
fairly thin, even fi1m over the viewing area. A disadvan-
tage of this practice is the tendency to introduce too much
liquid onto the slide surface, resulting in overflcw off
the slide surface, displacement of the cover slide, and an
uneven or undesirably thick layer of the specimen over the
viewing area. Moreover, preparation and handling of the
flat slides and fragile cover slips is unnecessarily ~wk-
ward, often resulting in spillage or runoff and possible
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contamination of the liquid sample. Finally, each slide
can accommodate only one specimen at a time; if comparison
between samples is desired, then slides must be prepared
and viewed separately, which is time-consuming and necessi-
tates even further handling.
Previous attempts to overcome the foregoing limi-
tations have generally proposed that the slide be provided
with an arrangement of channels in communication ~ith a
somewhat raised viewing surface. A cover slip is posi-
tioned over the viewing area so that liquid placed in thechannel will be drawn across the space by the process of
capillary action. Representative of this approach is U.S.
Letters Patent No. 2,039,219 to Hausser et al which disclo-
ses a haemacytometer having a series of transverse c~annels
and a pair of oppositely inclined surfaces leading to a
raised examination area. A cover slide is placed over the
raised and channeled areas and a narrow chamber is formed
therebetween~. The specimen is introduced, as by a dropper,
onto one of the inclined portions and is drawn into the
chamber; excess liquid remains in the reservoirs formed by
the inclined surfaces.
U.S. Letters Patent ~o. 3,565,537 to Fielding
:
~ teaches a somewhat similar approach to a blood specimen
,
holder~for use with an opti~cal~measaring instrument. This
arrangement features a pair of translucent plastic plates,
one being formed with a shallow recess, which are welded
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~ together to form an intermediate channel for receiving the
s~ liquid sample by capillary action. The slide may then be
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examined under an optical instrument specifically designed
to measure the color o~ blood and thereby determine
hemoglobin content.
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A further example of the art in this field is U.S.
Letters Patent No. 3,777,283 to Elkins which defines a uni-
tary plastic slide adapted to accommoaate a plurality of
specimens. Each sample is retained by capillary action in
an open-sided chamber which is molded to a predetermined
area and depth within the body of the slide. Excess liquid
remaining in an introduction channel leading to the chamber
may be removed by tapping the open or channel side of the
slide against absorbent toweling or the like. Further, as
the specimen chamber is formed integrally with the slide,
this arrangement does not employ a cover slip.
It is therefore an object of the present invention
to provide for a novel and improved transparent slide
arrangement suitable for examining li~uid specimens, such
as, blood and urine in a reliable and efficient manner.
Another object of the present invention is to pro-
vide for a novel and 1mproved liquid specimen slide
arrangement in which a liquid specimen is drawn uniformly
across a viewing surface in such a way as to present a good
o representative sample for purposes of examination and
qualitative analysis.
It i5 a further object of the present invention to
provide for a novel and improved liquid specimen slide
which is so constructed and arranged as to encourage uni-
form flow of a~liquid across a viewing surface and removal
of eYCess liquid which may flow over the edges of the
viewing surface thereby preventing displacement of a cover
slip or leakage of the specimen into adjacent viewing
areas.
30Yet another ob ject o~ the present invention is to
provide for a novel and lmproved transparent slide arrange-
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65895-118
ment having a plurality of viewing areas formed thereon, for
example, ~o facilitate comparison of different specimens while
avoiding contamination and intermixture, to catalog related
specimens, or to test specimen reaction to a series of
xeagents.
Still ano~her object of the present inventlon is to
provide a transparent slide whe~ein a liquicl specimen is
rapidly drawn by capillary action into a narrow viewing space,
and is distributed within the space in an extremely thin layer
of substantiaIly constant depth so as to permit undistorted and
accurate examination of the specimen and any particulate matter
suspended therein.
A further object of the invention is to provide a ~;
specimen slide having novel and improved means to act as a
positioning guide and retaining means for a cover sllp placed
over the specimen viewing areas.
Yet another ohject of the present invention is to
provide a transparent slide arrangement which may be
,
manufactured with rèlative ease and economy using inexpensi~e
materials, such as, plastics so that the slide~may be either
discarded~after use or sterili~ed for reuse.
In~ summary, the inventlon provldes a speci:en slide
assembly used~for examining liquid speclmens. The specimen
slide has a plate with an upper, substantially fIat examination
surface~whlch lncludes at~le:st~one vlewln~ sur~ace wlth a
continuous channel disposed~in surrounding relation thereto so ~'
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as to isolate the viewing sur~ace from the rest o~ the
examination sur~ace. The channel has a broadened reaessed area
which contacts a side edge of the viewing surface and whiah
includes a well` to receive a liquid speclmen. ~ ~ransparent
cover plate and a locator on the examination surface~of the
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slide plate is operative to support the cover plate in
predetermined spaced relation to the vi~wing surfacs and a side
edge of the cover plate is aligned to partially expose a
portion of the broadened recessed area.
In accordance wi~h the present invention, a specimen
slide has been devised for use in combination with a
conventional cover plate for the microscopic examlnation of
liquid specimens, such as, blood and urlne. The slide is an
elongated transparent plate of yenerally rectangular
configuration having opposite ends and sides and is provided
with an upper examination surface, at least one open
rectangular chanr,el beiny formed in the examination surface and
spaced from the ends and sides of the plate so as to define a
flat viewing surface within the channel which ls completely
isolated from the rest o~ the examination surface. The cover
plate is removabl~ disposed over the viewing surface portion
and is sized to leave at least a~portion of the channel exposed
for introduction of a liquid samp~le, ~he spaclng between the
viewing surface~ and facing or contlguous surface of the cover
plate being such as to permit uniform distribution of a portion
of the liquid sample over the viewing surface. Preferably, a
series of isolated viewing~surfaces are formed in this manner
and unlformly spaced along the length of th~e slide with a
channel or groove surrounding and defining each viewing
,
`surface, each channel including a shallow well or broadened
rece6s of semi-circular conflguration which communicates with
each viewing surface through a notch which extends a
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limited distance from the channel into the viewing surface
midway alo~g one side edge of the viewing surface. The
examination surface preferably is slightly raised above the
viewing surface to establish a predetermined spacing bet-
ween the cover plate and viewing surfaces, and locating
ribs are disposed around outer edges of the slide to faci-
litate proper positioning of the cover slip with respect to
the slide.
The above and other objects, advantages and
features of the present inve~tion will become more readily
understood and appreciated from a consideration of the
following detailed description of a preferred embodiment
when taken together with the accompanying drawings in
which:
Figure 1 is a top plan view of a preferred form of
specimen slide ln accordance with the present invention;
Figure 2 is a cross-sectional view taken about
lines 2-2 of Figure l;
Figure 3 is a cross~sectional view taken about
lines 3-3 of Figure li and
Figure 4 is a somewhat perspective view of the :
pre-ferred form of invention.
Referring in detail to the drawings, a preferred
form of slide 10 is specifically adaptable for use in
~ualitative analysis of liquid specimens, such as, bloQd,
urine and the like. As illustrated, the slide 10 is in the
form of a thin, transparent plate of generally rectan~ular
configuration having opposite ends 11 and 12, opposite
sides 13 and 14 and upper and lower spaced parallel sur-
faces 15 and 16. The upper surface 15 serves as the exami-
nation surface and is divided i.nto a series of isolated
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viewing surface portions 18, each portion 18 being in the
form of a flat rectangular platform and each completely
surrounded by a rectangular channel 20. Each channel 20 in
turn is spaced from an ad]acent channel 20 by intermediate
flat surface portions 22 in the original plane of the upper
examination surface as are the viewing surface portions 18.
Moreover, each viewing surface portion 18 and its asso-
ciated channel 20 are spaced inwardly from the ends and
sides 11, 12 and 13, 14, respectively,
It will be seen that the viewing surfaces 18 are
spaced along the length of the slide 10 and, as described,
are completely isolated from one another so as to define
independent areas or portions for the examination of a
liquid specimen. In order to receive a liquid specimen for
viewing purposes, a well 24 of generally semi-circular con-
figuration i5 formed as a broadened recess area along one
section of each channel adjacent to a side edge 14 but is
spaced inwardly therefrom. A beveled notch 25 of generally
V-ahaped configuration is inset into an outside edge of a
viewing surface portion 18 midway therealong so as to be
aligned directly opposite to each well and to communicate
with its respective well through the channel extending
therebetween. The channel and well for each viewing sur-
face are of uniform depth so as to form a continuous con-
duit for the liquid which i~ introduced, for example, by a
dropper into each well; and, at the same time, serves as a
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receptacle for any excess liquid deposited in the well and
which is not drawn over the viewing surface portion in a
manner to be hereinafter described.
In the preferred form, in order to establish a
predetermined spacing between the cover slip C and viewing
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surface portions 18, raised surface portions or pads 26 are
disposed for extension across the substantial width of the
examination surface at each end thereof together with an
intermediate pad 27 which extends transversely between the
innermost adjacent viewing surface portions. In addition,
a pad 28 which is relatively narrow compax~ed to the pads 26
and 27 extends along one side 13 o* ~he examination surface
in spaced relation to the pads 26 and 27. The pads 26 to
28 as described are raised slightly above the original
plane of the examination surface, such as, by addition of a
film or thin sheet, or by the formation of roughened areas
at the sectors designated for the pads and which thickness
may be anywhere on the order of up to 0.004". In addition,
cover slip C is guided into proper position with respect to
the vlewing surface portion of the channels by outer
locating ribs which in the preferred form include ribs 30
at opposite ends of the examination surface and a rib 32
around the one side edge 13 bordering the outsides of the
pads 26 and 28, respectively. As previously noted, pads 26
and 27 terminate short of the pad 28, and as shown the ribs
30 terminate short of the rib 32 so as to define ar~ unin-
terrupted inner passage 35 when the cover slip is posi~
tioned in place over the examination surface. Stated
another way, the air passage 35 is de*ined merely by the
original plane of the examination surface and the
confronting surface of the cover slip to permit adequate
ventin~ or release of air from or within the channels 20
when liquid is deposited. In this respect, it will be seen
that limited air space or passages 36 are formed imme-
diately surrounding each of the channels and the forwardedge 14 of the slide.
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In practice, when a 5Iip iS positioned over the
slide it is dimensioned to seat snugly within and against
the locating ribs 30, 32 while resting on the pads 26 and
28. As shown, it is dimensioned to overlie the viewing
surface portions 18 with one outer side 34 partially
overlapping the channels or the channel portions in which
the wells are formed so as to leave the wells fully exposed
fo'r placement of a liquid specimenO Both the slide 10 and
cover slip C may be composed of a stiff transparent glass
or plastic material having deslred characteristics of wet-
tability and for example may be composed of a clear or
crystal polystyrene or acrylic material. Typically, for a
slide 3" in length, 1" wide four viewing surface portions
18 are spaced along the length o~ the one side 14. For a
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slide .070" thick, the channels are given a depth on the
order of .030" as are the wel~s communicating with the
channels. Each viewing surface portion 18 has an area on
the order of Q.141 square inches and the channels are
0.090" wide. These dimensions are given more for the pur-
pose of illustration and not limitation, the important con-
sideration being in the ability to isolate the viewing
surface portion 18, yet to permit uniform distribution of a
; liquid~specimen by capillary attraction over the viewing
surface. It has b~een found ~hat the notched area aids 25
in the initial movement or migration of the liquid ~rom the
well upwardly alon~ the surface of the notch onto the
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`~ viewing surface portion 18. Thus, it is~necessary only to
place a thickne=s or amount of liquid in each well
necessary only to partially fill the channel, and the -~
30 liqui~ then will be drawn by capillary attraction over the
viewing sur~ace portion. It is only on those occasions
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when the channel should become filled with excess liquid
adjacent to the well that the remainder of the channel 20
will provide a ready conduit for removal of the excess as
it is slowly drawn onto the viewing surface.
It is therefore to be understood that various
modifications and c~anges may be made in the construction
and arrangement of parts comprising the preferred embodi-
ment of the present invention without departing from the
spirit and scope of the invention as defined by the accom-
10 panying claims and any reasonable equivalents thereo~.
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