Abstract:
A system for sampling air and collecting particles potentially including bioagents entrained in the air for detection. The system comprises collecting a sample of the air with the particles entrained in the air, directing the sample to a receiving surface, directing a liquid to the receiving surface thereby producing a liquid surface, wherein the particles potentially including bioagents become captured in the liquid, and heating the liquid wherein the particles potentially including bioagents become heated to lysis the bioagents.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit of U.S. Provisional Patent Application No. 60/734,805 filed Nov. 8, 2005 and titled “Biobriefcase Aerosol Collector Heater.” U.S. Provisional Patent Application No. 660/734,805 filed Nov. 8, 2005 and titled “Biobriefcase Aerosol Collector Heater” is incorporated herein by this reference.  
         [0002]     Related systems are disclosed in U.S. patent application Ser. No. (______) filed Aug. 1, 2006 and titled “Biobriefcase Aerosol Collector” and U.S. patent application Ser. No. (______) filed Aug. 1, 2006 and titled “Biobriefcase Electrostatic Aerosol Collector.” U.S. patent application Ser. No. (______) filed Aug. 1, 2006 and titled “Biobriefcase Aerosol Collector” and U.S. patent application Ser. No. (______) filed Aug. 1, 2006 and titled “Biobriefcase Electrostatic Aerosol Collector” are incorporated herein by this reference. 
     
    
       [0003]     The United States Government has rights in this invention pursuant to Contract No. W-7405-ENG 48 between the United States Department of Energy and the University of California for the operation of Lawrence Livermore National Laboratory. 
     
    
     BACKGROUND  
       [0004]     1. Field of Endeavor  
         [0005]     The present invention relates to sampling and more particularly to aerosol sampling.  
         [0006]     2. State of Technology  
         [0007]     U.S. Pat. No. 6,688,187 issued Feb. 10, 2004 to Donald A. Masquelier for “An Aerosol Sampling System” provides the following state of technology information, “As the threat of biological weapons (BW) increases, both in military theaters and civilian populations, the need for complete systems for the rapid detection and analysis of pathogenic organisms becomes increasingly important.” 
         [0008]     United States Patent Application No. 2002/0045246 to William A. McMillan et al and assigned to Cepheid for a “Device for Lysing Cells, Spores, or Microorganisms” published Apr. 18, 2002 provides the following state of technology information, “Abstract: A device for use with an ultrasonic transducer to lyse components of a fluid sample comprises a cartridge having a lysing chamber, an inlet port in fluid communication with the lysing chamber, and an outlet port for exit of the sample from the lysing chamber. The inlet and outlet ports are positioned to permit flow of the sample through the lysing chamber, and the chamber contains at least one solid phase for capturing the sample components to be lysed as the sample flows through the chamber. The lysing chamber is defined by at least one wall having an external surface for contacting the transducer to effect the transfer of ultrasonic energy to the chamber.” 
         [0009]     U.S. Pat. No. 6,520,034 issued Feb. 18, 2005 to Donald A. Masquelier et al for a “High Air Volume to Low Liquid Volume Aerosol Collector” provides the following state of technology information, “The first step in any system for detection and characterization of biological agents is a sample collector. This can take on the simple form of a cotton swab for solid surfaces, or as in the case of airborne pathogens, an aerosol sample collector is used to collect and concentrate airborne particulate into a liquid sample volume for subsequent preparation and analysis. An aerosol sampler is the most appropriate for continuous monitoring scenarios, where repeated swabbing of settled particles is impractical. Most commercial samplers now available for field use are large, power consuming, and produce collected sample into large volumes of liquid, typically &gt;10 mL. Emerging miniature detection systems analyze much smaller sample volumes, typically &lt;250 μL. When using the presently available air samplers, the sample volume must be ‘sub-sampled,’ effectively diluting the sample, resulting in a loss of sensitivity of detection. Thus, there is a need for a collector which will collect particulate at a high airflow and yet utilize a low liquid volume.” 
       SUMMARY  
       [0010]     Features and advantages of the present invention will become apparent from the following description. Applicants are providing this description, which includes drawings and examples of specific embodiments, to give a broad representation of the invention. Various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this description and by practice of the invention. The scope of the invention is not intended to be limited to the particular forms disclosed and the invention covers all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the claims.  
         [0011]     The University of California has operated the Lawrence Livermore National Laboratory continuously since the laboratory&#39;s inception in 1952 and has extensive experience and resources in biology, chemistry, engineering, and computations. This gives the University of California and the Lawrence Livermore National Laboratory unique ability to tackle the problems of chemical and biological weapons proliferation and terrorist activities.  
         [0012]     In an article titled, “Biodetectors Evolving, Monitoring U.S. Cities,” by Sally Cole in the May 2003 issue of  Homeland Security Solutions  it was reported, “The anthrax letter attacks of 2001, and subsequent deaths of five people, brought home the reality of bioterrorism to Americans and provided a wake-up call for the U.S. government about the need for a method to detect and mitigate the impact of any such future attacks. Long before the anthrax letter attacks, scientists at two of the U.S. Department of Energy&#39;s national laboratories, Lawrence Livermore National Laboratory (LLNL) and Los Alamos National Laboratory (LANL), were busy pioneering a ‘biodetector’ akin to a smoke detector to rapidly detect the criminal use of biological agents. This technology is now expected to play a large role in the U.S. government&#39;s recently unveiled homeland security counter-terrorism initiative, Bio-Watch, which is designed to detect airborne bioterrorist attacks on major U.S. cities within hours. Announced back in January, Bio-Watch is a multi-faceted, multi-agency program that involves the U.S. Department of Energy, the Environmental Protection Agency (EPA), and the U.S. Department of Health and Human Services&#39; Centers for Disease Control and Prevention (CDC). Many of the EPA&#39;s 3,000 air-quality monitoring stations throughout the country are being adapted with biodetectors to register unusual quantities of a wide range of pathogens that cause diseases that incapacitate and kill, according to the EPA. The nationwide network of environmental monitors and biodetectors, which reportedly will eventually monitor more than 120 U.S. cities, is expected to detect and report a biological attack within 24 hours. Citing security reasons, the EPA declined to disclose further details about the program at this time.  
         [0013]     The Autonomous Pathogen Detection System (APDS) is a file-cabinet-sized machine that sucks in air, runs tests, and reports the results itself. APDS integrates a flow cytometer and real-time PCR detector with sample collection, sample preparation, and fluidics to provide a compact, autonomously operating instrument capable of simultaneously detecting multiple pathogens and/or toxins. ‘The system is designed for fixed locations,’ says Langlois, ‘where it continuously monitors air samples and automatically reports the presence of specific biological agents. APDS is targeted for domestic applications in which the public is at high risk of exposure to covert releases of bioagents—subway systems, transportation terminals, large office complexes, and convention centers . . . APDS provides the ability to measure up to 100 different agents and controls in a single sample,’ Langlois says. ‘It&#39;s being used in public buildings right now.’ The latest evolution of the biodetector, APDS-II, uses bead-capture immunoassays and a compact flow cytometer for the simultaneous identification of multiple biological simulants. Laboratory tests have demonstrated the fully autonomous operation of APDS-II for as long as 24 hours.” 
         [0014]     The term “biobriefcase” used in this patent application is intended to mean any device or system for monitoring airborne biological agents in a compact size. One biobriefcase device or system is described in the Sandia National Laboratories Chem/Bio Programs website as follows: “There is a serious need for broad-spectrum bioagent detection. Toward that end, the BioBriefcase project has been undertaken as a joint collaboration between Sandia and Lawrence Livermore National Laboratory for the Department of Homeland Security. It calls for a broad-spectrum bioagent detector that is briefcase-sized and features dramatically reduced reagent consumption, improved sensitivity and rapid response time. Sample preparation and analysis would be carried out on microfluidic, chip-based modules. The detector will use capillary electrophoresis on Sandia&#39;s ChemLab platform with three analysis trains; DNA amplification to identify bacteria and viruses using polymerase chain reaction (PCR); immunoassays to identify bacteria, viruses, toxins; and protein signatures to identify toxins. Serving as an environmental monitor, it should function autonomously to collect and detect samples in a stealthy and easily deployed manner. The BioBriefcase should also be capable of being manned by a minimally trained user to function as a portable laboratory, providing quick turn-around between sample analysis and responsive action.” 
         [0015]     The first step in any system for detection and characterization of bioagents is an aerosol sampling system that can be used to collect and concentrate airborne particulate into a liquid sample volume for subsequent preparation and analysis. Detection and identification of bioagents in the environment requires the collection and transport of particles into a liquid sample at a concentration exceeding some minimum detectable level. This is typically done with aerosol collectors, of which many types exist. Samples from aerosol collectors are concentrated into a fluid that will be processed and analyzed in a down stream detection system. Often collection systems suffer from low throughput, poor collection efficiency and difficulty operating in dirty environmental conditions.  
         [0016]     The present invention provides a system for sampling air and collecting particles entrained in the air for detection. The particles potentially include bioagents. A sample of the air with the particles entrained in the air is collected. The sample is directed to a receiving surface. A liquid is directed to the receiving surface producing a liquid surface. The liquid is heated wherein the particles potentially including bioagents become heated to lysis the bioagents.  
         [0017]     One embodiment of the invention provides an apparatus for sampling air and collecting particles entrained in the air, the particles potentially including bioagents. The apparatus comprises a receiving surface, a liquid input port that directs liquid to said receiving surface and produces a liquid surface, a collector that samples the air and directs the air so that the air with particles entrained in the air impact said liquid surface, wherein the particles potentially including bioagents become captured in said liquid, and a heater operable connected to said liquid that heats said liquid wherein the particles potentially including bioagents become heated to lysis the bioagents.  
         [0018]     One embodiment of the present invention is utilized as a spore germination cell, eliminating the need for lysis for the spores down stream of the collector and prior to the capture and detection systems. This is important, since normally some type of lysis is necessary to free DNA from spores. Accomplishing this in the collector will result in lower power and space consumption than is required using conventional methods.  
         [0019]     Organisms that can be collected by the present invention include protein toxins, bacteria, viruses, and chemicals. The present invention can be used to limit or prevent civilian exposure to biological pathogens, and initiate early treatment for those exposed; thereby decreasing mortality and morbidity from bioterrorism events. The present invention also has use in medical facilities and research and development facilities. There are a variety of medical applications where monitoring for biological pathogens is useful. A good example of this is monitoring in hospitals and clinics for highly infectious agents such as tuberculosis or nosocomial diseases that can threaten the well being of patients and health care professionals. The present invention also has use in environmental monitoring, that is any application that would benefit from environmental monitoring of biological species. One example is continuous aerosol monitoring of bacterial and other pathogens that could affect the health of livestock (such as the recent hoof and mouth disease outbreak).  
         [0020]     The invention is susceptible to modifications and alternative forms. Specific embodiments are shown by way of example. It is to be understood that the invention is not limited to the particular forms disclosed. The invention covers all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]     The accompanying drawings, which are incorporated into and constitute a part of the specification, illustrate specific embodiments of the invention and, together with the general description of the invention given above, and the detailed description of the specific embodiments, serve to explain the principles of the invention.  
         [0022]      FIG. 1  illustrates an embodiment of a biobriefcase aerosol collector of the present invention.  
         [0023]      FIG. 2  illustrates another embodiment of a biobriefcase aerosol collector of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0024]     Referring to the drawings, to the following detailed description, and to incorporated materials, detailed information about the invention is provided including the description of specific embodiments. The detailed description serves to explain the principles of the invention. The invention is susceptible to modifications and alternative forms. The invention is not limited to the particular forms disclosed. The invention covers all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the claims.  
         [0025]     Detection and identification of airborne contaminants and bio-hazards in the environment requires the collection and transport of particles into a liquid sample at a concentration exceeding some minimum detectable level. This is typically done with aerosol collectors, of which many types exist. Samples from aerosol collectors are concentrated into a fluid that will be processed and analyzed in a down stream detection system. Often collection systems suffer from low throughput, poor collection efficiency, and difficulty operating in dirty environmental conditions.  
         [0026]     Referring now to the drawings, and more particularly to  FIG. 1 , one embodiment of a biobriefcase aerosol collector of the present invention is illustrated. This embodiment of a biobriefcase aerosol collector is designated generally by the reference numeral  100 . The biobriefcase aerosol collector  100  samples the air and collects particles that potentially include bioagents entrained in the air.  
         [0027]     The biobriefcase aerosol collector  100  includes a collector that samples the air and collects an air sample that could potentially contain bioagents entrained in the air. An impactor separates the air sample into a first flow portion that does not contain entrained particles and a second flow portion that contains particles that potentially include bioagents. The second portion is directed to a receiving surface. Liquid is directed to the receiving surface and a liquid surface is produced. The second portion of the air sample is directed to the liquid surface so that the second portion of the air sample, with the entrained particles, impacts the liquid surface. The particles, potentially including bioagents, become captured in the liquid. A liquid output port directs the liquid and the particles, potentially including bioagents, captured in the liquid from the receiving surface for analysis.  
         [0028]     As illustrated in  FIG. 1 , the biobriefcase aerosol collector  100  includes the following structural components: high flow fan  101 , virtual impactor  102 , low flow fan  103 , contacts for fluid level control  104 , fluid bowl  105 , a receiving surface  106  on the fluid bowl, a sample out port  107 , a refill port  108 , a heater  114 , and a power source  115 . The heater  114  can be, for example, an electrical resistance heater. The heater  114  is operatively connected to the fluid bowl  105 . The power source  115  can be, for example, a battery connected to the heater  114 . A cone surface  113  is positioned adjacent the receiving surface  106  of the fluid bowl  105 . The cone surface  113  and the receiving surface  106  of the fluid bowl  105  produce an annulus for receiving the liquid  112 . The contacts for fluid level control  104  are on the cone surface  113 .  
         [0029]     The structural components of the biobriefcase aerosol collector  100  having been described, the operation of the biobriefcase aerosol collector  100  will now be considered. As illustrated in  FIG. 1  the high flow fan  101  brings air flow  109  into the biobriefcase aerosol collector  100 . The virtual impactor  102  divides air flow  109  flowing into the biobriefcase aerosol collector  100  into two components. For example the virtual impactor  102  can divide air flow  109  into two components as illustrated in U.S. Pat. No. 6,402,817 which is incorporated herein by reference. The first component is the major flow  110  of air less particle of interest. The second component is low flow  111  of air and concentrated particles. The low flow  111  of air and concentrated particles is directed to the fluid bowl  105 .  
         [0030]     The liquid  112  is directed to the receiving surface  106  of the fluid bowl  105 . In the embodiment illustrated in  FIG. 1 , the liquid is water. Other liquids are used in other embodiments. The liquid  112  provides a liquid surface. The low flow  111  of air and concentrated particles is directed onto the receiving surface of the liquid  112 . The open aerosol collector bowl  105  has a uniform volume of liquid  112  that is maintained by the contacts  104  for fluid level control. The bowl  105  is made of a stack of insulators and contacts that allow for a continuity measurement to be made between layers. The contacts  104  for fluid level control provide precise fluid flow and do not suffer from clogging or accumulation of debris in the collector bowl  105 . Additional fluid level sensors can be used. For example the contacts  104  can be acoustic contacts or optical sensors. The volume of low flow  111  of air and concentrated particles is flowed across the bowl  105  in an annulus at a rate with sufficient velocity to entrain the particles into the liquid surface, but cause minor turbulence on the surface  113  resulting in insignificant evaporation of the liquid. This leads to low fluid loss in the system  100 .  
         [0031]     The particles potentially including bioagents become captured in the liquid  112  by the air with particles entrained in the air impacting the liquid surface. The heater  114  connected to the liquid  112  heats the liquid  112 . The heater  114  and power source  115  heat the liquid  112  in the collector bowl  105 . In this configuration the collector bowl  105  is utilized as a spore germination cell, eliminating the need for lysis for the spores down stream of the collector and prior to the capture and detection systems. This is important, since normally some type of lysis is necessary to free DNA from spores. Accomplishing this in the collector will result in lower power and space consumption than is required using conventional methods.  
         [0032]     The resulting system is a compact, robust, and economical aerosol collector for use in field portable bio-detection systems. There are many uses for the biobrief case aerosol collector  100 . One is for sample collection of bio-hazards in transportation systems or other public environments. Another is for collection of samples for analysis of contamination in human and animal care facilities and distribution centers.  
         [0033]     The biobriefcase aerosol collector  100  has very low fluid consumption. The contacts  104  for fluid level control prevent contamination by debris and allow for high particle concentration rates. The resulting system is a compact, robust, and economical aerosol collector for use in field portable bio-detection systems. There are many uses for the biobriefcase aerosol collector  100 . One is for sample collection of bio-hazards in transportation systems or other public environments. Another is for collection of samples for analysis of contamination in human and animal care facilities and distribution centers.  
         [0034]     Referring now to  FIG. 2 , another embodiment of a biobriefcase aerosol collector of the present invention is illustrated. This embodiment of a biobriefcase aerosol collector is designated generally by the reference numeral  200 . The portion of the air sample that contains particles that potentially include bioagents is illustrated as intake air flow represented by the arrows  205 . The intake air flow  205  continues through the biobriefcase aerosol collector  200  as illustrated by the arrows  206 . The biobriefcase aerosol collector  200  includes structural components including a fluid bowl  201 , a liquid  202 , a bowl receiving surface  203 , a forcing cone surface  204 , a liquid surface  207  on the liquid  202 , a heater  210 , and a power source  211 . The heater  210  can be, for example, an electrical resistance heater to heat the liquid  202 . The power source  211  can be, for example, a battery connected to the heater  210 .  
         [0035]     The intake air flow  205  comes in through an intake  208 . The forcing cone surface  204  and the bowl surface  203  act together to form an air velocity increase. The velocity of the incoming air can be optimized by shimming the forcing cone  209  relative to the bowl surface  203 . This adjustment allows for optimization of the air volume, velocity and liquid surface disruptions. Significant liquid surface disruptions result in fluid loses due to slashing than evaporation. This configuration allows for particle collection with low fluid lost due to splashing. The air volume  206  passes over the liquid surface  207  interacting with the surface at adequate velocity to have the particles ingrain in the liquid  202 . Because this device is circular the air volume to liquid volume is very large.  
         [0036]     The particles potentially including bioagents become captured in the liquid  202  by the air with particles entrained in the air impacting the liquid surface  207 . The heater  210  and power source  211  heat the liquid  202  in the collector bowl  201 . In this configuration the collector bowl  201  is utilized as a spore germination cell, eliminating the need for lysis for the spores down stream of the collector and prior to the capture and detection systems. This is important, since normally some type of lysis is necessary to free DNA from spores. Accomplishing this in the collector will result in lower power and space consumption than is required using conventional methods.  
         [0037]     The resulting system is a compact, robust, and economical aerosol collector for use in field portable bio-detection systems. There are many uses for the biobrief case aerosol collector  200 . One is for sample collection of bio-hazards in transportation systems or other public environments. Another is for collection of samples for analysis of contamination in human and animal care facilities and distribution centers.  
         [0038]     While the invention may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims.