US2102785A - Method of and apparatus for sedimentation testing of blood - Google Patents

Description

C. BROOKS Dec. 21, 1937.

METHOD OF AND APPARATUS FOR SEDIMENTATION TESTING OF BLOOD Filed Oct. 18, 1955 (ZWQ E l0 FZWO Qul BL-OOD SETTL/NG CURVE I VENTOR. fi l/yak Braaka ATTORNEY.

Patented Dec. 21, 1937 f UNITED "STATES METHOD OF AND APPARATUS FOR SEDI- MENTATION TESTING OF BLOOD Clyde Brooks; New Orleans, La,

Application October 18, 1935, Serial No. 45,631

- 4 Claims. (01. 23 -230) My invention relates to the making of medical prognosis from the rateofsettlement-of red corpuscles' of blood; and itis designed to provide a method and an apparatus by which such settle mentor sedimentation can be efliciently effected and measured,even by technicians with but little training. The rate of'settling of the red blood corpuscles is a well known clinical phenomena, enabling a physician to make a prognosis in many diseases as well'as in operative cases, but this method of prognosis hasbeen relatively little used due to the highprobability of error and the difficulties and complexities involved in: making such tests heretofore. l

By my inventionr-such tests may be made'ac curately with a minimum quantity of blood, which is tested in a substantially undiluted and normal condition without'danger of coagulation, without affording any opportunity for settlement ofthe red corpus'clesin the test sample before the beginning of the test, and without the transfer of the test sample from one container ,to another.

My improved blood sedimentation tester comprises a transparent tube, preferably of glass, containing an axial bore extending thefull length thereof and having a settling section of substan-.' tially uniform small diameter which has a coat. ing of an anti-coagulant appliedthereto, immediately before each test A diametral conical valve seat is formed in the tube transversely to the axial bore for the re' ception of a rotatable glass cock or valve which 5 contains a passage movable by' the rotation "of the cock, into and outof registration with the tube bore; The settling section'of the tube is preferably graduated'from the bottom thereof, where'its 9 bore opens into'the-valve seatytoward the distal end of the tube, which may be conically ground for the attachment of a hollow needle.- 'The proximal end of the tube, below the valve seat,

is provided with a mouth piece for applying suc- 5 tion or pressure to the bore when the valve is open and'whichis cut oil from the settling section when the valve is closed to cut off the lower portion of a blood column in theinstrumentso as to leave in the settling section a column of 50 accurately measured lengthextending from the valve to the mouth of the tip.

' In accordancewith my improved methodfth blood is introduced into the'proximal end of the tube bore, with the 'valve passage in registration therewithluntil iti 1111s and projects i a solid" column slightly beyond the anti-coagulant coated settling section The fiOWgOf blood may be caused by inserting the hollow needle into aveiri or artery and permitting the pressure [of the i 4 blood therein to cause flow of blood into the 5- instrument, or the distal end of the tube bore may be applied todrop the blood formed by pricking the finger, or otherconvenient part and the blood drawn into the" instrument by suction applied to the mouthpiece at th e proximal end 10 V of the tube. a a

The characteristic features and advantages of my'improvements will furtherappear from the following description and the accompanying drawing'in illustration thereof.

In the drawing, Figi 1 is an exploded eleva tional view of a blood sedimentation tester or pipette embodying my invention, parts being shown in section: Fig. 2 is a fragmentarysectional view, on an enlarged scale, of a'portion of 20 the pipette shown in Fig. 1 as preparedfor use by coating the innersurface of the borewith anti coagulant; andFig. 3 is a chart showing the type of data determinable by my invention and the prognosis indicated thereby In the embodiment of my apparatus shownin Figs. 1 and 2 of the drawing, the glass pipette tube l contains a substantially uniform axialbore or lumen'Z extending the full length thereof and also contains a transverse conoidal ground valve 36 seat 3. A ground glass valve or co c k 4 is rotat; able in the seat 3 and is provided with a; bore 5' similar to and adapted to register with the bore 2 in one position of the valve. 1 V

The bore section between the valveseat.. ar 1 d distal point of the tube forms asettling chamber and {the blood content and corpuscularlse'ttling therein may be readily measured by means of'a, graduated millimeter scale etched on thejtube' with a datum, such as a 100 millimetermark, 4d placed exactly at the intersection ofthe settling chamber formed by the upper bore section vwith the valve seat. The zero point of the scale is preferably at the mouth of the tip of the bore. H A hollow needle 6 may be fitted on the tapered distal tip I of the tube 1 and a mouth-piece 81 may be connected by the flexible tube 9 with 'the proximalend ill of the tube,

- I have found that coagulation of blood, in quantities suitable for tests of 'therate of settling of red corpuscles in accordance with my invenf tion, can be'prevented by a mere film of anti-f coagulant on the inner surface of the wall of the bore in which the sedimentation is effected, p

' In carrying out my process in a preferred mau ner and by means of the illustrated apparatus, there should be prepared a suitable anti-coagulant solution, such as a sterile solution of sodium or potassium or ammonium oxalate, a sodium citrate, or hirudin, which may be conveniently put up in a sterile condition in a rubber capped vial.

The blood sedimentation pipette is sterilized, a suitable sterile hypodermic needle fitted on the ground glass tip of the pipette, and a piece of rubber tubing with mouth piece fitted on the opposite end of the pipette.

After sterilizing the surface of the rubber cap of the vial of anti-coagulant solution, the needle,

which is attached to the tip of the pipette, is

inserted through the cap into the solution. With the cock open, the oxalate solution is sucked by means of the mouthpiece through the needle and up into the bore of the pipette, filling it completely as far as, or a little beyond the 100 mark. The cock is then. turned to close the lumen of the pipette, and the needle is withdrawn from the vial or oxalate, solution and the filled pipette placed on some sterile surface. a

A rubber band is adjusted around the patients arm and an antiseptic rubbed over the skin covering the veins at the inner side of the bend of the elbow. I

The cock of the pipette is now opened and the oxalate solution blown out, leaving a thin film covering the inside of the pipette. The needle is quickly inserted into the lumen of the vein and the blood allowed'to. fiow up through the needle into the lumen ofthe pipette, filling it completely as far as the 100 markor a little beyond that point. The cock is then closed, thereby cutting oif the crest of the column and the needle withdrawn from the vein. The tip of the pipette is, then turned upward to the vertical position, the needle is removed from the ground glass tip and the tip wiped clean. This leaves the pipette completely and. precisely filled from. the very mouth of the tip (zero mark) to the point where the stop-cock cuts the lumen of the pipette (100 mark). Thus a column of fresh blood. is out. oil and held in the pipette, which column of blood is precisely 100 mm. in length. This measurement is automatically effected by the closing of the cock and the removal of the needle.

The pipette is set in a holder with the tip pointing vertically upward, and the settling of red corpuscles observed; the settling being read from the scale and the time. from a stop watch. The settling. should be noted, say, every minute in rapidly settling cases, and every five minutes in slower ones. The observations should be kept up vfor two hours andthe results. recorded and plotted n the. form of curves on coordinate paper.

The graphsshown on the chart in Fig. 3 illustrate, by way of example, the three stages of a case of' pneumonia. The lower curve l2 shows rapid sedimentation, during the period of severe illness; the next curve [3 shows a moderately rapid rate of. sedimentation during the period of convalescence; and the upper curve l4 shows a normal. healthy rate of sedimentation after recovery.

, By sterilizing the pipette and needle, when used, the whole test may be conducted under aseptic conditions so that any test may be extended, if desired, for'tWenty-four hours or-longer, to permit complete settling of the red corpuscles.

By my improvements the blood is allowed to flow directly from the blood vessel of the patient into the pipette, where it is immediately set up and the observation of sedimentation at once begun. This simplifies the procedure and avoids any dilution or mixing of the blood and there is no settling of the blood corpuscles before the actual observations have been started.

The operation of the pipette automatically cuts of? the column of blood precisely at-the mark and the removal of the hypodermic needle leaves the upper meniscus of the column exactly at the mouth of the tip of the pipette, so that the column of blood is exactly 100 mm. long. This measurement being automatic is always uniform and precise, even in the hands of inexpert laboratory workers. The results of measurements of rate of blood sedimentation are so accurate that very slight alterations in blood sedimentation can be determined with certainty.

There is no possibility of leakage because the stop-cock effectively closes the lower end of the graduated portion of the pipette. No air can get into the blood in the lumen of the pipette since the blood fiows into the pipette under its own pressure; If the needle does not fit the ground glass tip quite nicely, there'may be some blood leaking out but no air will pass into the pipette. No leakage can occur with the pipetteand' no air bubbles can enter the lumen of the pipette and get mixed with the blood. 1

Having described my invention, I claim:

1. A blood sedimentation pipette comprising a transparent tube and a stop cock intercepting said tube intermediate the ends thereof, said tube containing a capillary bore of.- substantially uniform cross-section extending from said stop cock to one end of the tube, said tube being graduated from said stop cock to said end, said graduations reading. from the end toward the stopcock, said tube containing a bore extending from the stop cock oppositely to the first bore, a mouthpiece communicating with the second bore for drawing blood by suction into the capillary bore in one position of the stop cock, said stop cock being movable to cut oil the suction of the capillary bore when thelatter is filled with blood.

2. A blood sedimentation pipette comprising a transparent tube and a stop cock intercepting said tube intermediate the ends thereof, said tube having a tapered end and containing a capilliary bore of substantially uniform cross section extending from said stop cock to said tapered end, said tube having a scale extending along said bore and providing graduations reading the entire distance from said end toward thestop cock, said tube containing a second bore extending from said stop cock, a fiexible'tube communicating with the second bore and having a mouthpiece for drawing blood by suction into the capillary bore in one position of the stop cock, said stop cock being movable to cut off suction from the first named bore when the latter is filled with blood.

3. A blood sedimentation pipette comprising a transparent tube and a stop cock intercepting said tube intermediate the ends thereof, said tube containing a capillary bore of substantially uniform cross-section extending from said stop cock to one end of the tube, a hollow needle removably fitted on the end of said tube and communicating with said bore, said tube containing a second bore extending from the stop cook, a mouthpiece communicating with the second bore for drawingblood by suction into the needle and capillary bore in one position of the stop cock, said stop cock being movable to cut off the suction from the first named bore when the latter is filled with blood, and said tube having a. scale reading from its distal end toward the stop-cock by which settling of said corpuscles may be observed over the entire distance from the distal end to the stop-cock.

4. The method of sedimentation testing of blood which consists in forming a capillary film of anti-coagulant, drawing blood from living tissue directly into the capillary by suction to form a blood column of uniform cross section, cutting ofi the blood column intermediate its ends, and positioning the major portion of the blood column so that the point at which it was cut off is lowermost until the corpuscles have settled.

CLYDE BROOKS.

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