US2415480A

US2415480A - Blood count equipment

Info

Publication number: US2415480A
Application number: US586248A
Authority: US
Inventors: Ethel M Gassert
Original assignee: Individual
Current assignee: Individual
Priority date: 1945-04-02
Filing date: 1945-04-02
Publication date: 1947-02-11
Anticipated expiration: 1964-02-11

Description

Feb. 11, 1947. E M., GASSERT 2,415,480 v BLOOD COUNT EQUIPMENT Filed Apri-l 2, 1945 HIVER/V575.

Patented Feb. 1l, 1947 PATENT OFFICE- 2;415,4so i noon COUNT EQUIPMENT'.

Ethel Misas-sert, Indianapolis, Indi' Appueaticnnpii a 1945, seriarNo. 586,248-

vertically across the slide; Themiddleplatform or floor piece is exactly'v 0.1 millimeter lower than the other-two `andis'p'rovided with capillary channels leading from either side of -the slide to the respective' counting chambers. This center platform is-g'enerally etchedat `two spaced points with` the Improved Neubauer ruling which =is a square 3 x-B millimeters divided by doublel'etched lines into nineequal squares 1 x 1 millimeter. The four corner squares are further divided i'byl single etched lines =into` sixteenequal squares.v The centersq'uare and `those above and below it-are' etched vertically into `twentyequal parts. Each fourth .line of these divisions'isdou-- ble etched.- The center square'r and. those on either4 siderarealso divided horizontally intoy twenty equal' parts each' fourthl'linelof which division is double etched; y

(b) The Hausser coverfglasa is' a rectangular plate 20 x 26millimeters`v withar thickness .between 0.4 and 0.61millimeters'.- 1t Jmust' be perfectly plane onboth sides.

(c) and (d) Blood diluting pipettesffcon'sist of a stem' provided .with a capillary'passage f and a bulb interposed betweenthe 'en'd's fof-said passage. The volumes of said ypassage and lbulbfareaccuratelycalibrated. The stem is divided into ten' equal 'parts' and calibratedryat 0;5Ian`d'1.0. The bullo is -of capacity to give an accurate 'dilutionv ofv the blood and diluent.v Generally'acdilutionof 1: 100 is used-for red corpuscles and ardilutionof 1 :20 for the 'white 'corpuscles In making'a-fblood 4count the blood -i'sldrawn into the pipette to the 0.5 mark, the --eXcessblood is wiped :off andthe pipette is lled with diluent to a mark located above the bulb. Then the pipette is shaken to mix-the y'contents thoroughly.

At least one-third of -the dilutedblood is expelled from the pipette and discarded Thecoverfglass" is placed over the platforms and each counting chamber isflledl'withi the L:diluted"bl` ')'cdi by capillary action through one of the channels above described. The mixture is allowed to standfor afew seconds' for 'the' corpus'cles -to settler and then the' slideis 'placed 'unda microscope 'and the counting is begun.

The difculties and disadvantages of this procedure are numerous. Allof the equipment must (elise- 40) be thoroughlyivandchemically vclean,vthorou`gh1y` dry and completely freefrom lint or dust of` anyv kind.- The wellfof the counting chamber must be very-accurately filled. with the diluted bloodan'd thesolutionin the-counting chamber must be en#- tirely.` freeofairbubbles. The count mustbe madev immediately, before evaporationY starts.- Scratches of any-kind on the counting chamber or cover glass render them unsatisfactory.

The primary object of the present vinvention is to overcome all Aofthese diiculties, 4and disadvantages, thereby greatly improving the accuracy. of the technician, and to save time in the enumeration of thecorpuscles ofthe blood. Accordingto the presentfrinvention, the stem ofthe pipette ywill beso constructed that a corpuscle count in the diluted blood in the pipette can jbe madedirectly fronrthe calibrated area in the stem. v

To the accomplishmentof thetabove and related objects, my invention may'beembodied in the forms illustrated in the accompanying drawing, attention beingcalled to the fact, however, that. theI drawing` is illustrative only, andthat change may be made in the specic constructionsillustratedand described,l so long as the scope-of theA appended claims is not violated.

Fig.v 1 is a plan view of a` pipette constructed in` accordance'wth the present invention;

Fig.V 2 is a -longitudinal section thereof;

Fig.v 3 lis a-plan view, upon an enlarged scale, of that-section of the pipette stem which constitutes the counting.v chamber;

Fig. 4 is atransverse.sectiomupon an enlarged scale, .through the stem of the `pipette Figs is ahplan Vview cfav holder for pipettes constructedinaccordance Iwith the present inl vention; and

Fig. -6 is an-end elevation of '-such holder with two pipettes supported thereon.

Referring moreparticularly' to the drawing, it will -be Seen that I-havey illustrated a pipette, in dicatedgenerally by the reference numeral IIJ, andformedto provideV a capillary passage H. Said npassage .opens at one end into an enlarged mixingichjamber |2-,- and acontinuation Il of saidpassage leads through one end I3 of'the pipette designed for attachment of a rubber tube and mouth-piece; while lthe mouth I4I ofthe pas-V4 sagev ll opens :throughfthe opposite end l-of they tion-of the"pip'ett`e stemi'adjacent the counting chamber shall be transparent. It is my present opinion that the best way to produce these desirable features will be yto make the pipette of glass, or one of the highly transparent, relativelyv ing a surface, intended to mate with the surface I6 and formed with a rectangular channel, or' n can be made in relation to the lines 2| of the varea 20.

trough, I8, the inside upper suriaceof which is also perfectly plane. If the pipette is formed of fusible material, such as glass, the, two elements I5 and II may be brought into contacting relation and fused together in the fmanner indicated in Fig. 4, whereby the trough I8 will cooperate with the plane` surface I6 to produce a" rectangular passage Il." If the pipette is formed of non-fusible material, themating surfaces ofV theffelements I5 and' I 'I Will preferably be securetll together by seme suitable adhesive, the requirement beingfthat such adhesive be leak-proof to the various chemicals used and be non-corrosive. The element I 'I will be provided with equally longitudinally spaced graduations I9, whereby the volume of" liquid drawn into the passage II may be measured.

yEtclied into the surface I5 of the element I5 is the Improved Neubauer ruling, or one of equal accuracy, 2l, defining a square area 20. Following l'theestablished practice, the area 20 will be exactly' millimeters square, and the depth of the trough I 8 Will be exactly `0.1 millir'neizer.v Thus the'width of the channel I8 must'b'e atleast 3.0 millimeters;` and preferably it Will be somewhat greater. If the Width of said channel is only 3.0 millimeters, its lateral ledges may cause refraction orreiiectionwhich may interfere with microscopic leina'iiriiriation of the countingchamber.- l A holder should preferably be provided to keep thepipetteinplaceo'n the floor of the microscope While counting. -A'suitable form of holder irs-illustrated in Fig. 5 and comprises a plate 22, which may be made of transparent or non-transparent material, andwhich is'formed with a groove 23 to receivethe stem of a` pipette, andvvithV a' socket 2d adapted to receive the-bulb thereof. A rectangular" opening 2'I is formed in the center ofthe holder to register With-the area 2B to permit the passage of light through that area-of the pipette during the counting of the corpuscles.

Preferably, but 'not necessarily, the plate 22V is likewise formed with a second groove parallel with-ithe groove 2'3, and traversed bythe open-i ing 21, for the reception of a second pipette, so that' red corpuscles in one pipette and White corpuscles inanotherpipette `can be counted with one 'mounting operation.l In Fig. 6, I have included apipette R for counting red corpuscles and a pipette -W for counting White corpuscles lyingftogetheronf-the holder 22. The bulb' I2 of-the'pip'ette R is larger than the bulb ofthe pipette -W, becauseof the greater dilution necessitated by the fact that the redcorpuscles are normally present-in greater numbers than White corpuscles, and therefore the inlet 24 is cutout; aswshown atV 26,' Vvvhile the socket 28 is not,'in order to bring the stems of thetwo pipettes into acominon plane. i i v l In the use' of the pipette of the present invention; a `measured quantity of blood to be examined` will be drawn into the passage I I, and so into chamber I2, a `measured quantity of diluent contents V'of lthe' 4 will then be drawn into chamber I2, and the blood and diluent will be mixed by shaking. Now the mixture is permitted to ow from the chamber,.l2 vintojshe.pagssage,II anda part of the mixtureiiis .ldirfardefl- News elecnethe. pipette 1tself in the special holder and then on the floor of the microscope the count of the corpuscles `Thus it becomes unnecessary to use other itemsof equipment, such as the separate countingchamber and the cover glass mentioned i at thejbeginningof the present specification.

I claimas my invention:

1. A pipette for use in making blood counts, said pipette being formed to provide an elongated f-passag`e-of substantially rectangular cross section opening into an enlargedvmixing chamber, one pair of opposite walls of said passage having registeringtransparent sections, and one of said' sections being provided with accurately spaced intersecting gradutions.

2. A pipette for use in making blood counts, said pipette being formed to provide an elongated passage of substantially rectangular cross sectionv opening into an enlarged mixing chamber,

the minor dimension of ak portion of said passagebeing exactly 0.1 mm. and the major dimension thereofbeing at least 3.0 mm., the majorf'walls of said portion being transparent and one of said major Walls being provided with accurately4 spaced intersecting graduations.

Y 3..A pipette .for use in makinggblood counts, comprising astem havingan elongatedat surface provided intermediate its'ends with a transparent calibrated area, and a Amating element formed in one surface with an elongated, substantially rectangular trough, said element being associated With said stem with its trough in leakproof relation to said flat surface, and the portion of said element registering with said calibratedarea being transparent.

4. A .pipette for use in making blood counts, comprising a stem of transparent material having .an elongated fiat surface provided intermediate its ends with a calibrated-area, and a mating' transparent element formed in one surface with an elongated,r substantially Vrectangular trough, said element being associated with said stem with its trough in leak-proof relation to said flat surface.i

5. The combination with a transparent pipetteI nEFERENcEs CITED The followingreferences areofvrecord in the iile ofthis patent: l j

Y I u UNITED STATES PATENTS Number' k y Name Date `1,762,807 Arnold 7..' June 1o, 1930 1,647,865 Hausser Nov. l, 1927