|Publication number||US3001914 A|
|Publication date||Sep 26, 1961|
|Filing date||Mar 5, 1956|
|Priority date||Mar 5, 1956|
|Publication number||US 3001914 A, US 3001914A, US-A-3001914, US3001914 A, US3001914A|
|Inventors||Ariel A Andersen|
|Original Assignee||Ariel A Andersen|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (4), Referenced by (69), Classifications (18)|
|External Links: USPTO, USPTO Assignment, Espacenet|
Sept. 26, 1961 A. A. ANDERSEN BACTERIAL AEROSOL ANALYZER Filed March 5. 1956 INVENTOR. Ar/e/ A. Andersen BY w F i 2 ATTORNEY llnited States Patent 3,001,914 BACTERIAL AEROSOL ANALYZER Ariel A. Andersen, 1074 Ash Ave., Provo, Utah Filed Mar. 5, 1956, Ser. No. 569,661 6 Claims. (Cl. 195103.5) (Granted under Title 35, US. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment to me of any royalty thereon.
This invention relates to an apparatus and method for counting and classifying viable particles in a gas. More particularly, the invention relates to an apparatus for counting bacteria or other microorganisms found in air,
water, soil or any substance that is capable of being suspended in air.
Specifically, the invention relates to a mechanism which serves to count and classify microorganisms in air and which will give a rapid and correct evaluation of these microorganisms.
The problem of determining contamination of the atmosphere by bacteria or other microorganisms is one of considerable difliculty since the time required for exposing and growing bacteria is considerable. Also, it is necessary to know the kind and relative size of such bacterial particles in order that remedial measures may be quickly taken.
It is the object of this invention to secure not only an accurate count, but an accurate classification of any microbial particles in the air and to separate such microbial particles according to size or mass and to grow them into colonies which can be analyzed.
In the drawings, FIG. 1 shows a top view of the apparatus. FIG. 2 shows a longitudinal section through the apparatus at 2, 2 of FIG. 1. FIG. 3 shows a corresponding section through two adjacent stages including the top stage. FIG. 4 shows diagrammatically the relative sizes of the perforations in the bottom of the respective stages.
More particularly, in the drawings, the cover is shown applied to the top unit 12. This is followed by subsequent units 16, 18, 20, 22, 24, and bottom unit 26. These cylindrical units are nested together under compression by means of spring tie rods 28. The units are held in air tight relation by means of plastic washers 30. Each unit has a transverse perforated wall 32, 34, 36, 38, 40, 42 with perforations progressively diminishing in size. The following table gives a series of sizes of perforations used and the range of particles which were collected under each size:
Diameter of holes in inches Size range of particles in microns Sampler Stage N o.
0 Below the perforated walls, Petri dishes 44, 46, 48, 50, 52, 54 are positioned. These dishes are partly filled with jections 58. By this means a continuous air channel isformed from the surface of each dish, around ,the'sides and under the same, to the perforated wall in the next lower stage. By this means a continuous air passage is created through the apparatus.
When suction is applied at the exit of bottom unit 36, air will enter through unit 10, pass through perforations 32 and around dish 44 through perforations 34 and so on, through all the stages of the analyzer. As the air passes through the perforations 32 its velocity is increased depending upon the size of the perforations and the rate at which the air is aspirated through the instrument. The viable particles in the air will reach a velocity corresponding to that of the air and the largest particles will be projected down to the surface of the nutrient medium in the first dish 44. Smaller particles, whose mass is less, do not reach the surface of the medium but are carried around dish 44 to pass through the smaller perforations 34 of the second stage 16. Due to the smaller perforations, the air velocity will be increased with the result that another group of particles will strike the nutrient medium in the second stage. This process continues with progressively diminishing perforations and progressively increasing air velocity at each stage, With the result that more and more of the particles are removed as the air approaches the exit of the apparatus. By choosing the proper sizes of perforations and the proper air rate, it is possible to remove all particles on the Various stages. If it is desired to leave an amount of the smallest particulate matter in the exit air, these may be filtered out with a millipore filter at the exit of the apparatus. This filter is not necessary, however, and the apparatus may be terminated as shown in FIG. 2. with a simple bottom exit plate 26.
When the desired air sample has been aspirated, the analyzer is disassembled and the respective Petri dishes are removed for culturing the viable organisms gathered thereon.
In sensitivity tests on this sampler it has been found that the instrument is capable of detecting a bacterial cloud generated from 200 ml. of slurry at a distance of 38 miles. The device is sensitive to one viable particle in the total volume of air sampled.
The ability of the sampler to separate different size particles has been accurately determined by making tests on non-viable materials. It has been determined that the sampler is capable of collecting particles on each stage a very narrow range of sizes. Tests have been made on particles of carnauba wax, Krylon and egg slurry. The particles from these materials are all spherical and their sizes are therefore easily determined by microscopic analysis.
The following table shows the percent of the total particles found on each stage in six runs using Krylon and emphasizes the ability of the sampler to separate airborne particles in sizes,
Distribution of Krylon particles in bacterial aerosol analyzer. Totals from 6 trials (Analyzer run at one cubic foot per minute) Gradicule Number 1 2 3 4 5 6 7 8 9 Gradlcule size in Micrns (1.1) (1.6) (2.2) (3.1) (4.4) (6.3) (8.8) (12.5) (17.6)
percent From the distribution of pathogenic particles collected 25 creased so that by the time the last stage is reached, all
in the sampler, infection in animals or man may be predicted since it has been shown that respiratory infection by pathogenic particles is largely dependent upon the size of the particles inhaled.
This sampler has shown itself not only accurate but extremely convenient in making quick analysis of air samples where the presence of pathogenic particles is suspected. Results are obtained in about one-third the time compared with all glass impingers and at onehalf the cost in laboratory work per sample processed.
1. A method for classifying and culturing viable particles suspended in a gas which comprises passing a volume of gas through a number of stages in series, each stage including means to impart a fixed velocity to the gas stream and to utilize said velocity to deposit suspended particles above a given mass on to a nutrient surface by impaction, each succeeding stage serving to impart a gas velocity in excess of that obtaining in the preceding stage thereby to deposit particles of lesser and lesser mass in each succeeding stage and incubating the viable particles on the respective nutrient media whereby the viable particles become visible as colonies.
2. Apparatus for classifying and culturing viable particles in a gas comprising a series of stages, each stage including a transverse, uniformly perforated member positioned above and spaced from a layer of nutrient medium, each succeeding stage containing uniform perforations of gradually diminishing size per stage from the inlet to outlet of the apparatus and including means for passing the particle containing gas through the several stages in series.
3. A method of classifying according to size and identifying viable microscopic particles suspended in air, which comprises passing a volume of air through a seiies of stages, each stage containing a Petri dish of solid nutrient medium below a perforated plate having a fixed number of holes, the size of which is constant in each stage but which decreases in size in each succeeding stage, whereby jets of air, produced by drawing air through the device, increase in velocity with each succeeding stage and wherein said velocity increase in each succeeding stage is utilized to separate the microscopic particles into groups of decreasing size and mass, such that the groups of particles are collected by impaction on the nutrient medium of each succeeding stage and particles which are of insuflicient size and mass to be impacted on a given stage follow the air stream around the dish into the next stage where the velocity is inviable particles will have attained a velocity sutficient for impaction on one stage or another with the particles having the smallest mass being collected on the last stage, thereafter incubating the Petri dishes whereby viable microscopic particles will grow into visible colonies, the number of which represent the number of viable particles collected on that stage.
4. An apparatus for classifying according to size and identifying viable microscopic airborne particles comprising a series of stagesvconnected together with air tight seals, each of said stages comprising a Petri dish of solid nutrient medium positioned a fixed distance below a perforated plate, the number of perforations in said plates being constant for all of the stages and the size of said perforations being constant for each stage, said perforations being of decreasing size for each succeeding stage, said perforations serving to produce air jets which impinge on the nutrient medium as air is drawn through the apparatus, the velocity of said air jets increasing with each succeeding stage thereby causing particulate matter in the air drawn through the apparatus to be deposited on the nutrient medium of the respective stages, the smallest particles being collected on the last stage.
5. Apparatus for classifying and culturing viable particles in a gas, comprising a series of stages, each stage including a transverse uniformly perforated member positioned above and spaced from a layer of nutrient medium, each succeeding stage containing uniform perforations of gradually diminishing size per stage from the inlet to the outlet of the apparatus and wherein each stage includes an integralfianged section that serves to nest with the flanged sections of adjacent stages, whereby the assembled stages create a cylindrical casing for the apparatus and including means for passing the particle containing gas through the several stages in series.
-6. Apparatus in accordance with claim 5 wherein a Petri dish containing the nutrient medium is supported on the next succeeding stage in a manner to permit the gas to pass around said dish and to pass through the perforations of the succeeding stage.
References Cited in the file ofthis patent UNITED STATES PATENTS 991,572 Weisenstein May 9, 1911 2,296,566 Neumann Sept. 22, 1942 2,538,116 May Jan 16, 1951 FOREIGN PATENTS 659 Great Britain 1911.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US991572 *||Mar 30, 1910||May 9, 1911||Simon P Weisenstein||Air-filter.|
|US2296566 *||Aug 2, 1939||Sep 22, 1942||Willy Neumann||Filter|
|US2538116 *||Feb 7, 1946||Jan 16, 1951||Rowland May Kenneth||Apparatus for sampling particulate clouds|
|GB191100659A *||Title not available|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US3127329 *||Sep 5, 1961||Mar 31, 1964||Method and apparatus for sampling airborne micro-organisms|
|US3165450 *||Mar 11, 1963||Jan 12, 1965||St Luke S Hospital Res Foundat||Anaerobic culturing device|
|US3198713 *||Jul 6, 1962||Aug 3, 1965||Ames Atomium Inc||Stacked petri dishes|
|US3308558 *||May 14, 1964||Mar 14, 1967||Michael D Orlando||Environmental chamber|
|US3693457 *||Feb 24, 1971||Sep 26, 1972||Battelle Development Corp||Source test cascade impactor|
|US3787290 *||Apr 10, 1972||Jan 22, 1974||S Kaye||Method and means for assaying biological factors demonstrating quantal response|
|US3795135 *||Nov 7, 1972||Mar 5, 1974||2000 Inc||Sampler of air-borne particles|
|US3922905 *||May 13, 1974||Dec 2, 1975||Roth Thomas P||Disposable sampler|
|US3938366 *||Oct 29, 1974||Feb 17, 1976||Applied Bioscience||Aerosol analyzer|
|US3949594 *||Sep 25, 1974||Apr 13, 1976||The United States Of America As Represented By The Secretary Of Interior||Two-stage disposable particle sampling head|
|US3983743 *||Sep 19, 1973||Oct 5, 1976||Sierra Instruments, Inc.||Apparatus and method for the analysis of a particle-laden gas|
|US4038057 *||Oct 22, 1975||Jul 26, 1977||Andersen 2000, Inc.||Closed circuit sampler|
|US4189937 *||Aug 3, 1977||Feb 26, 1980||Nelson Philip A||Bounceless high pressure drop cascade impactor and a method for determining particle size distribution of an aerosol|
|US4211116 *||Jun 21, 1978||Jul 8, 1980||Electric Power Research Institute, Inc.||Assembly for and method of sampling particle-laden fluids and a cascade impactor used therewith|
|US4255172 *||Nov 14, 1979||Mar 10, 1981||Andersen Samplers Inc.||Jet impaction preseparator|
|US4274846 *||Feb 21, 1979||Jun 23, 1981||Andersen Samplers Inc.||Particle sizing sampler|
|US4327594 *||Jun 25, 1979||May 4, 1982||Nelson Philip A||Bounceless high pressure drop cascade impactor and a method for determining particle size distribution of an aerosol|
|US4387603 *||Sep 28, 1981||Jun 14, 1983||Nelson Philip A||Bounceless high pressure drop cascade impactor and a method for determining particle size distribution of an aerosol|
|US4735899 *||Mar 11, 1985||Apr 5, 1988||The Baker Company, Inc.||Detection of airborne microorganisms|
|US5304125 *||Mar 23, 1993||Apr 19, 1994||The University Of North Carolina||Apparatus for administering solid particulate aerosols to the lungs|
|US5360722 *||Jan 21, 1993||Nov 1, 1994||Kuraray Co., Ltd.||Method and apparatus for determining air borne bacteria|
|US5731210 *||Feb 25, 1997||Mar 24, 1998||R. J. Reynolds Tobacco Company||Environmental evaporation chamber and method of using same|
|US5831182 *||Oct 31, 1997||Nov 3, 1998||Swenson; Erik A.||Remote sampling device for determining air borne bacteria contamination levels in controlled environments|
|US6043049 *||Mar 31, 1999||Mar 28, 2000||Millipore S.A.||Method for detecting micro-organisms and cartridge suitable for implementing it|
|US6133020 *||May 7, 1997||Oct 17, 2000||Pitzurra; Ovidio||Apparatus for determining the number of microorganisms in the air and a method of operating said apparatus|
|US6294375 *||Apr 3, 1996||Sep 25, 2001||Ultra Propre Nutrition Industrie Recherche (U.N.I.R.)||Microbiological pressurised gas control device|
|US6342388||Nov 8, 1999||Jan 29, 2002||Pierre Van Den Wildenberg||Culture medium container, with integrated geometry for air suction and air conduction, for the purpose of air bacteria analysis|
|US6431014 *||Jul 23, 1999||Aug 13, 2002||Msp Corporation||High accuracy aerosol impactor and monitor|
|US6472203 *||Nov 1, 2000||Oct 29, 2002||Environmental Microbiology Laboratory, Inc.||Combination air sampling cassette and nutrient media dish|
|US6647758||Dec 8, 2000||Nov 18, 2003||Msp Corporation||Method and apparatus for verifying integrity of cascade impactors|
|US6685759||Jul 11, 2002||Feb 3, 2004||Southern Research Institute||Cascade impactor and jet plate for same|
|US6695146 *||Sep 17, 2001||Feb 24, 2004||Mesosystems Technology, Inc.||Method for surface deposition of concentrated airborne particles|
|US6938777||Feb 11, 2003||Sep 6, 2005||Mesosystems Technology, Inc.||Method for removing surface deposits of concentrated collected particles|
|US7265669||Mar 1, 2004||Sep 4, 2007||Mesosystems Technology, Inc.||Networks with sensors for air safety and security|
|US7578973||Mar 1, 2004||Aug 25, 2009||Mesosystems Technology, Inc.||Devices for continuous sampling of airborne particles using a regenerative surface|
|US7591980||Mar 1, 2004||Sep 22, 2009||Mesosystems Technology, Inc.||Biological alarm|
|US7597015 *||Jul 7, 2006||Oct 6, 2009||New York University||Particle size sampler|
|US7759123||Mar 21, 2006||Jul 20, 2010||Mesosystems Technology, Inc.||Removing surface deposits of concentrated collected particles|
|US7799567||Sep 21, 2010||Mesosystems Technology, Inc.||Air sampler based on virtual impaction and actual impaction|
|US7926368||Apr 19, 2011||Zefon International, Inc.||Humidity-controlled gas-borne matter collection device|
|US8047053||Nov 1, 2011||Icx Technologies, Inc.||Mail parcel screening using multiple detection technologies|
|US8173431||Nov 9, 2006||May 8, 2012||Flir Systems, Inc.||Mail screening to detect mail contaminated with biological harmful substances|
|US8243274||Mar 9, 2010||Aug 14, 2012||Flir Systems, Inc.||Portable diesel particulate monitor|
|US8596462||Sep 9, 2005||Dec 3, 2013||Bae Systems Plc||Particle separator|
|US20040016680 *||Feb 11, 2003||Jan 29, 2004||Mesosystems Technology, Inc.||Method for removing surface deposits of concentrated collected particles|
|US20040232052 *||Mar 1, 2004||Nov 25, 2004||Call Charles John||Methods and devices for continuous sampling of airborne particles using a regenerative surface|
|US20050190058 *||Mar 1, 2004||Sep 1, 2005||Call Charles J.||Networks with sensors for air safety and security|
|US20060127966 *||Feb 6, 2006||Jun 15, 2006||Zefon International, Inc.||Method of collecting gas-borne viable matter|
|US20060128008 *||Feb 6, 2006||Jun 15, 2006||Zefon International, Inc.||Gas-borne matter collection device|
|US20060257287 *||Feb 15, 2005||Nov 16, 2006||Call Charles J||Robust system for screening enclosed spaces for biological agents|
|US20070048186 *||Mar 21, 2006||Mar 1, 2007||Mesosystems Technology, Inc.||Removing surface deposits of concentrated collected particles|
|US20070056390 *||Jul 7, 2006||Mar 15, 2007||New York University||Particle size sampler|
|US20070107495 *||Nov 13, 2006||May 17, 2007||Dong-Hyun Kim||Particle adsorption chamber, sampling apparatus having a particle adsorption chamber, and sampling method using the same|
|US20070205142 *||Sep 9, 2005||Sep 6, 2007||Bae Systems Pic||Particle Separator|
|US20070269849 *||Oct 6, 2005||Nov 22, 2007||Pierre Bridenne||Air Sampling Method, Device and System for Microbiological Analysis|
|US20080070292 *||Dec 21, 2005||Mar 20, 2008||Acanthe||Sieve for Bio-Impactor, Bio-Impactor Equipped with Such a Sieve|
|US20080233636 *||Oct 26, 2007||Sep 25, 2008||Zefon International, Inc.||Humidity-controlled gas-borne matter collection device|
|US20090233350 *||Mar 10, 2009||Sep 17, 2009||Covidien Ag||Respiratory apparatus with a bioburden indicator|
|US20100212436 *||Aug 26, 2010||Erik Axel Swenson||Single use sterile slit impact sampling cassette with rotatable capture tray|
|US20100242632 *||Jul 18, 2006||Sep 30, 2010||Mesosystems Technology, Inc.||Air sampler based on virtual impaction and actual impaction|
|US20110159536 *||Jun 30, 2011||Hitachi Plant Technologies, Ltd.||Device for capturing object and method for using the same|
|US20110183371 *||Jun 25, 2009||Jul 28, 2011||Hideyuki Noda||Microbe-collecting carrier cartridge, carrier treating apparatus, and method of measuring microbes|
|US20130045893 *||Jan 14, 2011||Feb 21, 2013||The University Of Bristish Columbia||Apparatuses for determining whether a substance is carried in a fluid|
|EP0952211A1 *||Apr 21, 1999||Oct 27, 1999||Millipore S.A.||Method for detecting micro-organisms and cartridge suitable for implementing it|
|EP1008646A1 *||Nov 13, 1998||Jun 14, 2000||van den Wildenberg, Pierre||Culture medium container with integrated air suction and circulation geometry for aerial germs|
|EP1330637A2 *||Sep 25, 2001||Jul 30, 2003||Southern Research Institute||Particulate and process gas stream sampler|
|WO2002026341A3 *||Sep 25, 2001||Jun 13, 2002||Southern Res Inst||Particulate and process gas stream sampler|
|WO2006027591A1 *||Sep 9, 2005||Mar 16, 2006||Bae Systems Plc||Particle separator|
|WO2006072691A1 *||Dec 21, 2005||Jul 13, 2006||Acanthe||Sieve for bio-impactor, bio-impactor equipped with same|
|U.S. Classification||435/30, 73/28.5, 55/325, 435/305.1, 96/417, 435/299.2, 435/288.3, 55/485, 435/304.2, 435/309.1, 435/34, 435/305.4|
|Cooperative Classification||C12M33/14, C12M33/04, C12M41/36, C12M23/10|