Autonomous detection system

Autonomous Detection Systems (ADS), also called biohazard detection systems, or autonomous pathogen detection systems are designed to monitor air in an environment and to detect the presence of airborne chemicals, toxins, pathogens, or other biological agents capable of causing human illness or death. These systems monitor the air continuously and send real-time alerts to appropriate authorities in the event of an act of bioterrorism or biological warfare.
History.
In the United States, an ADS system (BDS) was developed for the U.S. Postal Service following the anthrax scare of 2001. The first detection systems in U.S Postal services were installed in 2006.To counter such problems in the future, United States Federal Govt set up a program called BioWatch which operates in more than 21 cities in the US. In 2001 the United States experienced the effects of bioterrorism for the first time when envelopes containing anthrax spores were sent through the U.S. Postal Service to several recipients, including two U.S. senators. In addition to the 5 deaths and 17 cases of anthrax infection that resulted, there were substantial economic costs and significant operational challenges in public health and health care, from the federal level down to the community level.
BioWatch.
The BioWatch program is funded and supervised by the Department of Homeland Security (DHS). The BioWatch program has three main components: sampling, analysis, and response, each of this component is handled by three different agencies. The Environmental Protection Agency (EPA) handles the sampling component —  the sensors that collect airborne particles. The Centers for Disease Control and Prevention (CDC) coordinates the analysis and laboratory testing of the samples. Local authorities are responsible for the public health response to positive findings. The Federal Bureau of Investigation (FBI) is designated as the lead agency for the law enforcement response if a bioterrorism event is detected. (Shea and Lister, 2003)
Structure.
Shaped like a mailbox on wheels.
Mechanism.
APDS monitors the air for the three types of biological threat agents: bacteria, viruses, and toxins. The autonomous detection is capable of (1) rapidly processing and accurately analyzing aerosol samples with a high level of confidence; (2) automating and integrating the major system functions into the detector, including aerosol sample collection, preparation, analysis, and analytical results reporting; (3) operating in its intended indoor and outdoor environments; and (4) disseminating and archiving analysis results and system operational data via the C3 network, known as the BioWatch Gen-3 Operations Support Service.
APDS operates continuously, the system can detect low concentrations of bioagents that might go undetected by a system that is triggered only when the overall number of particles in the air is high. APDS collects samples, prepares them for analysis, and tests for multiple biological agents. This automation reduces the cost and staffing that would be required to manually analyze samples.
As APDS collects air samples, it first runs them through an immunoassay detector. If that detector returns a positive result, APDS performs a second assay based on nucleic-acid amplification and detection. Having two different assay systems increases system reliability and minimizes the possibility of false positives.
The immunoassay detector incorporates liquid arrays, a multiplexed assay that uses small-diameter polystyrene beads (microbeads) coated with thousands of antibodies. Each microbead is colored with a unique combination of red- and orange-emitting dyes. The number of agents that can be detected in a sample is limited only by the number of colored bead sets. When the sample is exposed to the beads, a bioagent, if present, binds to the bead with the appropriate antibody. A second fluorescently labeled antibody is then added to the sample, resulting in a highly fluorescent target for flow analysis. Preparing the sample and performing this first analysis takes less than 30 minutes.
Nucleic acid assays require amplification of one or more target sequences of nucleic acid. Short strands of single-stranded DNA are synthesized in known sequences and attached to spots in the array in a predetermined way Detection of these spots that contain hybridized target DNA allows one to the sequence of DNA in the unknown target. RNA readily hybridizes to form double-stranded structures to its complementary sequence (A-T, C-G, G-C, U-A). Thus, arrays of single-stranded DNA can be used to detect RNA via hybridization.
TABLE 1.1 Centers for Disease Control and Prevention (CDC) Prioritized List of Biological Threat Agents"a"
Research Internationals sells stand alone and portable systems for use in mailrooms, called ASAP II. ASAP II gives real time detection of bio-warfare agents, chemical agents and toxic industrial chemicals, explosives in particulate and vapor form and nuclear materials. The system can be customised according to the need of the mailroom.
ASAP II is an automated chemical, biological and nuclear detection and identification system. The system can detect and identify from four(RAPTOR module) to eight (BioHawk module) bio-agents in real time. Periodically or on demand, a concentrated sample is sent to the modules and within fifteen minutes these systems will identify the presence of any bioagents and notify the operator if a hazardous agent is detected.
The systems need to be in a negative pressure room on a downward draft table, they are able to handle thousands of pieces of mail per hour. An air sampling module within the systems draws air into the downward draft table for analysis. Sampling is continuous until the batch of mail is complete, it may be a few minutes of hours or days.
Application.
The system can be adapted for situations where environmental or clinical pathogens require monitoring. For example, APDS could test for mold or fungal spores in buildings or for the airborne spread of contagious materials in hospitals. It also could identify disease outbreaks in livestock transport centers or feedlots.
Automated Mailroom Detection Systems.
BioAlert System.
Research International produces and sells the TacBio particle detection system. The system samples the air continuously and monitors for  aerosol particle or bio-particle levels
It does not identify the type of bio- particle detected but will notify the mailroom attendant if either excess particles or bio-particles are present. This is an early warning system that gives the mailroom supervisor enough time to notice a potential threat and to test for biological agents or  airborne threats before mail is delivered to a recipient.
Hand Held and Stand Alone Systems.
ChemPRO 100 Chemical Detection System is a handheld chemical detector for field detection and classification of Chemical Warfare Agents. If mail arrives with an unidentified substance, this hand held detector can be used to immediately identify the chemical.
Hardened Mobile Trace Explosive Particle tests for a wide range of explosives and narcotics in seconds. The system will identify explosives in packages or envelopes that are often undetectable by x-ray machines. This handheld detector expands the range of target explosives you can identify in a single sample for faster more comprehensive screening. As noted, this system also detects a wide range of narcotics. The system tests for explosives and narcotics simultaneously in a single sample, for faster, more comprehensive screening.