Method and system for detection of contaminants in mail

#The invention disclosed herein relates generally to the processing of mail, and more particularly to a method and system to detect possible contaminants contained within a mail piece.

#The United States currently has the world's largest postal system, which handles billions of pieces of mail each year. The servicing of mail delivery involves three general steps: collection, sorting, and delivery. Collection takes place through a series of local post office facilities and Bulk Mail Entry Units (BMEU) spread throughout the United States. The mail is then sent from local post offices or BMEUs to central facilities known as sectional centers. At the sectional centers, high speed automated equipment sorts the large volumes of mail based on the destination post office or zip code for delivery.

#Recently, the postal system has been used as a weapon of terror and fear by the inclusion of harmful chemical or biological contaminants, such as, for example, the spore-forming bacterium Bacillus anthracis (anthrax), within or on a mail piece. Such contaminants can be carried in several forms, including for example, a powder form. The harmful effects of only a few contaminated mail pieces can be far reaching, as cross-contamination of other mail pieces can easily occur when the mail pieces come in contact with each other or are passed through the same machines during sorting. The Centers for Disease Control and Prevention estimates that tens of thousands of mail pieces could have become cross-contaminated from only two contaminated mail pieces.

#The above and other objects and advantages of the present invention will be apparent upon consideration of the following detailed description, taken in conjunction with accompanying drawings, in which like reference characters refer to like parts throughout, and in which:

#FIG. 1 illustrates in block diagram form a contaminant detection system according to the present invention before a mail piece has entered;

#FIG. 2 illustrates in block diagram form the contaminant detection system according to the present invention after a mail piece has entered; and

#In describing the present invention, reference is made to the drawings, wherein there is seen in FIG. 1 a system 10 for contaminant detection according to the present invention. Such contaminants could include, for example, biological or chemical contaminants. System 10 includes a control unit 50 for controlling operation of the system 10. Control unit 50 could be, for example, a general purpose processor or an application specific integrated circuit (ASIC). Preferably, control unit 50 is a self-contained sealed unit or sufficiently isolated such that if a contaminated mail piece is detected, control unit 50 will not be cross-contaminated. System 10 preferably includes a test chamber 12 having an inlet side 14 and an outlet side 16. Test chamber 12 is utilized to reduce exposure to air and dust particles that may escape from a mail piece 22 during testing as described below. Test chamber 12 is preferably designed such that it can be easily decontaminated should a contaminated mail piece be detected. A diverter 18 is coupled to the outlet side of chamber 12, or alternatively, diverter 18 could be integral with test chamber 12. Diverter 18 will pass a mail piece to either a normal processing path 32 or a reject path 34 based on signals received from control unit 50 as will be further described below.

#A transport 20 is utilized to transport a mail piece 22 received at the inlet side 14 through chamber 12. Transport 20 could be, for example, a belt/roller combination as illustrated, or any other type of transport as is known in the art. The movement of transport 20 is controlled by a motor 26 based on signals received from control unit 50. A corresponding pair of sensors 30a, 30b are located along the transport 20 for detection of a mail piece 22 on transport 20. A probe insertion unit 40 controls the insertion of a probe 42 into a mail piece 22 detected by sensors 30a, 30b. Probe 42 may be, for example, a needle with sufficient strength and rigidity to penetrate mail piece 22. Preferably, a backplate 24 is provided to oppose the force of probe 42 on the mail piece 22 to ensure penetration of the probe 42 into mail piece 22. Probe 42 is provided with an opening 44 near the penetration end through which air extraction system 46 can extract a sample of air, including dust and other particles, from a mail piece 22 via tube 48. The sample extracted by air extraction system 46 is passed to air analysis system 52 via tube 54. Alternatively, air analysis system 52 and air extraction system 46 may be integrated as a single unit. Air analysis system 52 is coupled to control unit 50 to provide data pertaining to the analysis results of the extracted sample.

#The operation of system 10 will now be described with respect to FIG. 2. When the leading edge 60 of mail piece 22 is detected by sensors 30a, 30b, a signal is sent to control unit 50 which then sends a signal to motor 26 to halt motion of transport 20. Accordingly, transport 20 is stopped such that at least a portion of mail piece 22 is adjacent to the probe 42. When the mail piece 22 has sufficiently decelerated or come to a complete stop, the control unit 50 sends a signal to probe insertion unit 40 to move the probe 42 towards the mail piece 22 and thereby penetrate the mail piece 22 as illustrated in FIG. 3. Preferably, probe 42 penetrates the mail piece 22 near a corner of the mail piece 22, as loose particulate matter, such as, for example, a powdery substance, would tend to accumulate and settle in the corners of the mail piece 22. After penetration by probe 42, at least a portion of the opening 44 of probe 42 must be inside the mail piece 22. As noted above, a backplate 24 may be provided to oppose the force of the probe 42 on the mail piece 22 and ensure penetration of the probe 42 into mail piece 22.