HAND-HELD EXPLOSIVE DETECTION SYSTEM

FIELD OF INVENTION

The present invention generally relates to the field of explosive detection systems, and more specifically to the detection of trace materials. More specifically, the present invention relates to hand-held systems and techniques for detecting the presence of trace chemicals, and in particular, explosives on the clothing or skin of a person. Still more specifically, the present invention relates to a trace explosives detection system that can be used as a first pass screening solution.

BACKGROUND OF THE INVENTION

Trace detection machines are being used with increasing frequency for securing public locations. Trace detectors are used to detect and identify trace quantities of contraband, such as explosives and narcotics, on the surfaces of objects such as luggage, parcels, and clothing. Trace detection systems are based, in principle, on the idea that trace amounts of explosive materials, chemicals and/or contraband will be transferred to the body of a person who handled the material. Trace materials may also be transferred from the body to any article that the person may wear or carry.

Currently, various detection systems and devices are employed to detect the presence of contraband on the body or luggage of individuals entering the secure area. Contraband is not limited to weapons and arms, but, rather, it includes explosives (fireworks, ammunition, sparklers, matches, gunpowder, signal flares); weapons (guns, swords, pepper sprays, martial arts weapons, knives); pressurized containers (hair sprays, insect repellant, oxygen/propane tanks); poisons (insecticides, pesticides, arsenic, cyanide); household items (flammable liquids, solvents, bleach); and corrosives (acids, lye, mercury).

Conventional trace detection sampling techniques include chemical sniffers, swab-based systems, and vapor detection systems. Conventional swab-based trace detection systems operate by swabbing an appropriate material across a purse, suitcase or other article that has been handled by a person under inspection. The swab is then inserted into a trace detection apparatus which subsequently tests for and detects the presence of a chemical contained in typical contraband.

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Chemical sniffers are commonly used for the detection of certain types of explosives; however, they are currently not effective in detecting all types of existing explosives. Manual searching of subjects is slow, is inconvenient, and is usually not sufficient for detecting trace chemical materials on a subject on the order of 1 gram or less. Chemical Reagents Color Technology (CRCT) is a reliable, conventional technique used to detect explosive micro-particles of different types. However, conventional CRCT techniques employ a manual sampling procedure and manual analysis. Typically, a sample is obtained by manually wiping the suspect surface with a test paper. The subsequent analysis is made by dropping a series of chemical reagents onto the test paper. A chemical interaction between the reagents and the collected explosive microscopic particles is generally indicated by the presence or appearance of a color on a white test paper. A color appearance generally reliably indicates the presence of an explosive chemical.

Conventional vapor detection systems attempt to provide trace material contraband testing without physically contacting the person under inspection or articles of interest that the person under inspection may be transporting. Certain prior art devices comprise walk-through portals for screening a person. Such prior art devices create a flow of air in the area of the portal in an effort to entrap the vapors (and thus, the particles contained in the vapors) of interest in a continuously flowing air stream. The air stream, containing vapors (or particles) of interest, is then transported to a detector for identification of vapors (or particles) of interest. In addition, some prior art systems further comprise a filter to absorb target particles. The above-mentioned prior art devices are disadvantageous in that they draw a significant volume of air from outside the area of the portal, substantially diluting the concentration of vapors (or particles) of interest in the air stream that is transported towards the detector.

For example, United States Patent Number 6,073,499 (the '"499 patent"), assigned to Penn State Research Foundation, describes "a portal for collecting substances of interest from a human subject passing therethrough, said portal comprising a plurality of sidewalls spaced from one another sufficiently to define a passage extending therebetween, said sidewalls defining an entry to said passage and an exit therefrom, said entry, said exit and said passage being dimensioned for accommodating passage of the human subject through said portal, a ceiling extending across and connecting top portions of said sidewalls and covering said passage, portions of said ceiling adjacent said passage defining a collector, said collector comprising fan

means for collecting air heated by body heat of the human subject and rising upwardly adjacent the human subject as a human thermal plume of heated air at a flow rate on the order of approximately 30-50 liter/sec, said fan means being operative for accommodating the air in the human thermal plume without substantial dilution of air in the human thermal plume by extraneous air".

Certain prior art trace detection systems, such as the system described in the '499 patent, describe the use of air jets to dislodge particles of interest from clothing. Air jets, however, can create turbulence that may disrupt the efficient upward flow of air in the natural thermal plume surrounding the human under inspection. Additionally, air jets have the potential of creating air flow patterns that will draw significant volumes of air from the ambient surroundings, thereby reducing the concentration of the particles of interest in the flow of air directed to the detector. Further, air sampling portal machines tend to be less reliable as they are not designed or intended for high clutter areas and may pick up stray environmental particles that yield a false positive.

Although the detection portal of the '499 patent may be effective for detecting trace amounts of contraband that may have been deposited on the skin of a suspect, microscopic particles of contraband may very likely be trapped in the clothing of a suspect. Further, the system described in the '499 patent is a portal system, and thus, cumbersome and requires a special allocated screening area.

Conventional trace detection systems often suffer from low throughput. Prior art systems focus on material identification and discrimination, a process which can take minutes to hours, depending upon the technology employed. In order to help alleviate some of the sampling, throughput, and space requirement issues, systems have become more portable, and require less time to complete an analysis. But while next generation conventional trace explosive detection systems are more compact and achieve material identification, they still suffer from disadvantages.

For example, one of the obstacles of using conventional trace detection systems is that the larger a given sample size, the longer the analysis time. Thus, in using ion detection techniques or mass spectrometry, an operator must obtain a microgram or less of material to minimize analysis time. Further, prior art trace detection systems often require extensive operator skill and training for material discrimination and analysis.

For example, Figure 1 shows several "portable" prior art trace explosive detection systems. As shown in Figure 1, Smiths IonScan® products 101 are legacy systems that are difficult to transport and require a time consuming process to perform material identification. More specifically, the IonScan® 101 detects and quantifies trace analytes using ion mobility spectrometry (IMS), where the characteristic speed at which an ion moves is under the influence of an electric field, i.e., its ion mobility, is a distinct thumbprint that identifies the original substance. A solid or liquid sample is introduced to the analyzer by thermal desorption or direct injection. The resultant vapors are swept in through the inlet by the carrier gas and ionized. The product ions are gated into the drift tube and accelerated by an electric field toward the detector. Air flows through the drift tube in a direction counter to the electric field. Drift times depend on the size, shape, and mass of the ionized analyte and range from about 3 to 50 milliseconds. Thus, operator skill in analyzing the resultant spectra may be necessary.

More compact systems, such as the non-contact trace explosive detectors also suffer from operational and mechanical disadvantages. The Sabre® 4000, by Smiths, is a hand-held explosive detection system that also uses ion mobility spectrometry and is designed for specially trained emergency responders, not trained security personnel. Further, the sampling tip of the Smiths system suffers serious disadvantages due to its small size and thus, lower reliability in obtaining a trace sample.

In addition, United States Patent Number 5,648,047 (the '"047 patent"), assigned to Israel Levy, describes "[a] hand-held device for colorimetric detection of a chemical obtained by sampling a surface of an object for enabling a large number of tests to be successively performed, the hand-held device comprising: (a) a housing having means for handling and using the handheld device, said housing including a sampling area and a testing area, said sampling area being formed as a tip, said tip being dimensioned and positioned for permitting the sampling of the surface of an object by wiping the surface of the object; (b) a roll of substrate for sampling materials suspected as including the chemical from the surface of the object; (c) a feeding reel being rotatably connected to said housing, said feeding reel accommodating said roll of substrate, said substrate extending at least from said feeding reel to said tip and said testing area; (d) at least one container for accommodating at least one detecting reagent, wherein said at least one detecting reagent is for the colorimetric detection of the chemical; and (e) at least one dispensing

mechanism for dispensing a predetermined volume of said at least one reagent onto said substrate at said testing area." The '047 patent is herein incorporated by reference in its entirety.

The '047 patent suffers from several disadvantages, however. Firstly, the system of the '047 patent focuses on colorimetric material identification, wherein the user has to determine the presence and identification of a chemical based upon a visual color change. Secondly, some reagents, as also mentioned in United States Patent Number 5,296,380, which is herein incorporated by reference, quickly deteriorate when exposed to air and thus must be stored in a sealed ampoule prior to use. Thirdly, the pointed tip that is employed for sample collection in the '047 patent has a reduced sampling size and thus may not effectively collect trace particles. Further, the conventional systems described above suffer from low throughput, and thus, cannot be effectively used as a first pass screening solution.

Thus, what is needed is a hand-held trace material detection system that is capable of high throughput. Accordingly, there is a need for a system that can quickly determine the presence of an explosive/chemical substance in a first pass screening. What is also needed is a hand-held trace material detection system that has a high probability of reliable detection and a low false alarm rate.

What is also needed is a cost effective hand-held trace material detection system.

What is also needed is a hand-held explosive detection system that can be used at a variety of locations without requiring an allocated screening area. What is also needed is a trace detection system that is capable of effectively dislodging particles of interest embedded in the clothing and skin of persons under inspection. What is also needed is a trace detection system with an improved air sampling mechanism.

What is also needed is a trace detection system having an analysis sub-system and testing method in which at least one reagent has an extended shelf life. Accordingly, what is needed is a sampling material that is treated with at least one reagent in a dry form for subsequent use in analysis.

What is also needed is a trace detection system having an automatic analysis module to analyze sampled particles.

What is also needed is a trace detection system that is capable of providing a fast "Pass/No Pass" (or "Go/No Go") indication to an operator of the system.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide for the detection of trace materials.

More specifically, it is an object of the present invention to provide a hand-held system and method for detecting the presence of trace chemicals, and in particular, explosives on the clothing or skin of a person. It is another object of the present invention to provide a trace explosives detection system that can be used as a rapid first pass screening solution.

In one embodiment, the present invention is a hand-held device for determining the presence of a chemical on a subject, comprising: a housing, further comprising a handle for using the device, having a proximal end and a distal end, a battery pack removably connected to said distal end of said handle on said housing, and a sampling interface, integrally connected to said proximal end of said handle on said housing, wherein said sampling interface comprises raised surface areas (including bumps, protusions, extensions, or any other elevations from a planar surface) that allow for agitation of the subject surface to ensure that a maximum sample portion is obtained; a disposable cartridge, removably connected to said housing at the proximal end; a sampling sub-system, operably connected to said sampling interface, further comprising a suction inlet for collecting samples into the detection system; a dispensing sub -system, operably connected to said sampling sub-system; and a color detection sub-system, operably connected to said sampling sub-system.

In one embodiment, the color detection sub-system comprises a colorimeter.

In one embodiment, the battery pack is replaceable or rechargeable and further comprises at least one battery pack removal button.

In one embodiment, the disposable cartridge further comprises a top cartridge cover, at least one reagent container, a main cartridge enclosure, a substrate reel, and a bottom cartridge cover. In another embodiment, the disposable cartridge further comprises a pressure release interface for removing the disposable cartridge from the system. In one embodiment, the substrate reel further comprises at least one sampling area of interest and at least one analysis area of interest. Further, the substrate reel comprises a chemically coated paper and is pre-treated with at least one chemical reagent.

In one embodiment, the chemical reagents container contains at least one reagent container column and a maximum of 2000 μL of test fluid and further has an orifice for reagent

dispensing. In one embodiment, the reagent container orifice is used to deposit at least one chemical reagent onto the area of interest.

In one embodiment, the hand-held device further comprises a gear mechanism, such as a stepper motor gear assembly having a drive pinion mounted on a stepper motor for advancing the substrate reel on the disposable cartridge using rotational movement, wherein the disposable cartridge comprises a drive pulley bobbin and a paper bobbin.

In another embodiment, the present invention is a method for obtaining and analyzing a sample using a hand-held explosive detection system, comprising: activating a power switch to power on the system; positioning a subject in a designated location; initiating a scan by activating a start test button; moving the system along the surface of the subject to be scanned; collecting a trace sample; analyzing the collected sample to determine whether the collected sample contains explosives; and indicating whether a color presence is detected on a display.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention will be appreciated, as they become better understood by reference to the following Detailed Description when considered in connection with the accompanying drawings, wherein:

Figure 1 shows several prior art trace explosive detection systems;

Figures 2A and 2B illustrate top and side views, respectively, of a one embodiment of the hand-held explosive detection system of the present invention;

Figures 3 A and 3B are top views of one embodiment of the hand-held explosive detection system of the present invention;

Figure 4 illustrates a bottom side view of one embodiment of the hand-held explosive detection system of the present invention;

Figure 5 A depicts one embodiment of the location of a sampling interface, as used in the hand-held explosive detection system of the present invention; Figure 5B is a schematic diagram of the sampling interface shown in Figure 5 A;

Figures 6A-6F show several views of a replaceable battery pack in its compartment, the replaceable battery pack while it is being removed from its compartment, and the replaceable battery pack alone, as used in the hand-held explosive detection system of the present invention;

Figure 7A shows one view of one embodiment of a disposable cartridge area for placing a disposable cartridge in the hand-held explosive detection system of the present invention;

Figures 7B-7D show several dimensional views of a disposable cartridge area for placing a disposable cartridge in the hand-held explosive detection system of the present invention; Figure 8 is an expanded view of one embodiment of a disposable cartridge and its housing as employed in the hand-held explosive detection system of the present invention;

Figure 9A is a depiction of the front side of one embodiment of a disposable cartridge, showing a pressure release interface, a sampling area of interest position, and an analysis area of interest position; Figures 9B, 9C, and 9D are dimensional views of the pressure release interface assembly shown in Figure 9A;

Figure 1OA is a depiction of the back side of one embodiment of a disposable cartridge, showing a reagents container and a pressure release interface;

Figures 1OB and 1OC are schematic diagrams of the reagents container shown in Figure 1OA, shown both intact and taken apart, respectively;

Figure 1OD is a schematic diagram of the stepper motor gear assembly used in the disposable cassette used in the system of the present invention;

Figures 1OE, 1OF, and 1OG are dimensional diagrams shown in several views of one embodiment of a disposable cassette used in the system of the present invention; Figure 11 is a flow chart describing the operational steps of one embodiment of the handheld explosive detection system of the present invention;

Figure 12 is a schematic diagram of one embodiment of a sampling sub-system as used in the hand-held explosive detection system of the present invention; and

Figure 13 is an illustration of one embodiment of a display, an LED indicator, and a start button that may be used in the hand-held explosive detection system of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed towards systems and methods for screening subjects at security locations while preserving the privacy of subjects and retaining the efficiency and thus, throughput, of the screening process. In particular, the present invention is directed towards a

hand-held explosive detection system. Still more particularly, the present invention is directed towards a stand-alone explosive detection system that is operator-friendly.

In one embodiment, the present invention is directed towards a hand-held explosive detection system comprising a housing, a battery pack, a disposable cartridge, a sampling sub- system, a dispensing sub-system, and a color detection sub-system. In one embodiment, the housing further comprises a power ON/OFF switch, a display, a disposable cartridge cover, a start test push button, at least one LED, and an audible alarm, such as, but not limited to a buzzer.

In one embodiment, the present invention is directed toward a hand-held trace material detection system that is capable of high throughput. Further, the system of the present invention determines the presence of an explosive/chemical substance in a first pass screening. In one embodiment, the hand-held explosive detection system of the present invention provides for a "go/no go" or "pass/no pass" approach to screening that is particularly effective in a first pass screening stage.

In one embodiment, the present invention is directed towards a hand-held trace material detection system that has a high probability of reliable detection and a low positive false alarm rate. In one embodiment, the present invention is capable of providing sufficient flow-through rates to screen substantially all subjects, their belongings, and vehicles at crowded entry points such as, but not limited to train stations, metro stations, government buildings, shopping malls, military bases/infrastructures, medical centers, museums, libraries, and sports venues. In another embodiment, the present invention is capable of screening the interiors of cars and/or other vehicles that approach underground, indoor, and/or public parking structures. In another embodiment, the present invention is capable of screening the interior compartments of baggage and/or luggage.

In another embodiment, the present invention is directed towards a cost effective hand- held trace material detection system.

In yet another embodiment, the present invention is directed towards a hand-held explosive detection system that can be used at a variety of locations without requiring an allocated screening area.

In still another embodiment, the present invention is directed towards a trace detection system that is capable of effectively dislodging particles of interest embedded in the clothing and skin of persons under inspection. In particular, the present invention is directed towards a trace

detection system having an improved air sampling mechanism. In one embodiment, the system of the present invention has a detection sensitivity of 1 microgram of trace material.

In another embodiment, the present invention is directed towards a trace detection system having an analysis sub-system and testing method in which at least one reagent has an extended shelf life. Accordingly, the present invention is also directed towards a sampling material that is treated with at least one reagent in a dry form for subsequent use in analysis.

In yet another embodiment, the present invention is capable of detecting the presence of several varieties of explosives, including, but not limited to military, commercial, and improvised explosives. In one embodiment, the present invention is capable of detecting the presence of polynitro aromatics, such as but not limited to TNT, Tetryl, TNB, and picric acid and its salts. In another embodiment, the present invention is capable of detecting the presence of nitrate esters and nitramines, such as but not limited to RDX, PETN, SEMTEX, C4, Smokeless Powder, Dynamite, and Nitrocellulose. In another embodiment, the present invention is capable of detecting the presence of nitrate salts, such as but not limited to ammonium nitrate, potassium nitrate, and urea nitrate.

The present invention is directed toward multiple embodiments. Language used in this specification should not be interpreted as a general disavowal of any one specific embodiment or used to limit the claims beyond the meaning of the terms used therein.

Figures 2A and 2B illustrate elevated side views of one embodiment of the hand-held explosive detection system of the present invention, showing components and dimensions, respectively. In one embodiment, the hand-held explosive detection system 200 comprises an outer housing 210, a replaceable battery pack 220, a disposable cartridge area and housing cover (collectively referred to as the "scan head") 230, and a display 240. The explosive detection system of the present invention further comprises power ON/OFF switch 250, start scan button 260, and removable or detachable belt strap 270. The explosive detection system of the present invention further comprises an air sampling sub-system (not shown), a dispensing sub-system (not shown), and a color detection sub-system (not shown). In one embodiment, the color detection sub-system comprises a colorimeter (not shown) that is low cost and provides a color appearance indication only. The operational characteristics of the air sampling sub-system, dispensing sub-system, and color detection sub-system are described in greater detail below with respect to Figure 11.

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As shown in Figure 2B, the relative dimensions of the hand-held explosive detection system, in one embodiment, are as follows: the length of scan head 230 is preferably 192mm.

Further, the thickness of scan head 230 is preferably 45 mm. Still further, the overall height, or the thickest point of the explosive detection system of the present invention is, in one embodiment, no greater than 126 mm.

It should be noted herein that in one embodiment, the housing components and enclosures are fabricated from plastic or antistatic plastic materials. Further, the connectivity between the enclosure components is established by using snap and screw fittings, where necessary. Common plastic materials and snap and screw fittings, as are known to those of ordinary skill in the art, may be employed in this invention.

Figures 3 A and 3B are top views of one embodiment of the hand-held explosive detection system of the present invention further showing features of the housing and relative dimensions of the housing, respectively. Referring now to Figure 3A, in one embodiment, housing 300 comprises a battery pack portion 301, a handle portion 302, and a scan head portion 303. In one embodiment, battery pack portion 301 comprises a power ON/OFF switch 305 and replaceable battery pack 325. In one embodiment, scan head portion 303 further comprises a display 310, a disposable cartridge cover 315, a start test push button 320, and LEDs 330.

As shown in Figure 3B the overall length 331 of the explosive detection system of the present invention is preferably 398 mm. In addition, the hand-held explosive detection system of the present invention preferably comprises the following dimensions: scan head portion 303 has a width 335 of approximately 105 mm; battery pack portion 301 has a width 340 of approximately 109 mm and a battery pack portion length 301 of approximately 53 mm; handle portion 302 has a length 350 of approximately 113 mm and a linear width 355 of approximately 53 mm. It should be noted that the hand-held detection system described with respect to Figures

2B and 3B has been fabricated with consideration towards human engineering and use. Handle portion 302 is thus designed considering that it will be held by a human hand of varying sizes. Thus, while the dimensions arrived at are not restrictive, the present invention has been configured for this specific dimensional configuration. It should be noted by one of ordinary skill in the art that as the sizes of the internal components change, the overall size of the system housing may be retrofitted to fit this requirement.

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Figure 4 illustrates a bottom perspective view of one embodiment of the hand-held explosive detection system of the present invention. As shown in Figure 4, housing 400 further comprises sampling interface 405, which is located at the bottom surface of the scan head described above with respect to Figures 2 and 3, and a cover 410 through which a rechargeable or replaceable battery pack can be inserted.

Figure 5A depicts one embodiment of a sampling interface, as used in the hand-held explosive detection system 500 of the present invention. In one embodiment, the sampling interface 505 comprises raised surface bumps 510 and a suction inlet 515. The raised surface bumps 510 of the scanning interface allows for agitation of the surface to ensure that a maximum sample portion is obtained. The sampling interface is connected to a sampling sub-system via suction inlet 515. The sampling sub-system and its operational characteristics are described in greater detail below with respect to Figure 11.

Now referring to Figure 5B, relative dimensions of the sampling interface described with reference to Figure 5 A is shown. In one embodiment, sampling interface 505 has an elliptical area of about approximately 55 mm x 35 mm. In one embodiment, suction inlet 515 has an internal diameter of approximately 6.5 mm and a length of approximately 53 mm along the neutral axis from the point of trace particle entry to the deposit of the particles on the substrate.

Figures 6A-6F show different views of a replaceable battery pack compartment and replaceable battery pack, as used in the hand-held explosive detection system of the present invention. In one embodiment, as shown in Figure 6A, the replaceable battery pack is integrated into the distal end 610 of handle 615 of the hand-held explosive detection system 600 of the present invention. Replaceable battery pack 605 further comprises at least one battery removal button 620, which in one embodiment, can be slid to remove the replaceable battery pack 605 from the explosive detection system for replacement or recharging. In one embodiment, two battery pack removal buttons 620 are employed, one on each side of the battery pack. As shown in Figure 6B, the battery pack 605 is inserted into the distal end 610 of handle 615 of the handheld explosive detection system 600 of the present invention, in the direction of the arrow. As shown in Figure 6C, battery pack 605 is removable and replaceable. In one embodiment, battery pack 605 is rechargeable. In one embodiment, battery pack 605 comprises at least one lithium- ion battery. In one embodiment, battery pack 605 comprises a plurality of individual lithium-ion batteries that are packaged with the necessary protection circuitry located on the inside of the

outer plastic covering. In another embodiment, battery pack 605 is integrated with an enclosure for use in the hand-held explosive detection system 600 of the present invention.

Now referring to Figures 6D-6F, the relative dimensions of the replaceable battery pack 605 are shown. In one embodiment, as shown in Figure 6D, the replaceable battery pack 605 has an overall length 650 of approximately 143 mm and a length 655 of approximately 53 mm at the distal end portion 660 of replaceable battery pack 605. As shown in Figure 6E, replaceable battery pack 605 has a width 670 of approximately 114 mm and a height 675 of approximately 80 mm. Replaceable battery pack 605 is attached to the handle (not shown) of the system of the present invention at its proximal end 665, which has a diameter 680 of approximately 45 mm. Figure 7A is a depiction of one embodiment of a disposable cartridge area for placing a disposable cartridge in the hand-held explosive detection system 700 of the present invention. As shown in Figure 7A, disposable cartridge seating area 705 is located on the proximal end 709 of handle 710 of system 700. As will be described in greater detail below, disposable cartridges preferably comprise a shape that is identical to the disposable cartridge area 705, so that it fits into the hand-held explosive detection system with minimal mobility and maximum stability.

In addition, referring to Figure 7A, disposable cartridge area 705 optionally comprises a gear or turning mechanism 720 for advancing to a new testing area, the operation of which is described in greater detail below with respect to Figures 9 A and 9B.

Figures 7B, 7C, and 7D are schematic diagrams showing dimensional details of the proximal end of handle 710, including cartridge seating area 705, described with respect to Figure 7A. In one embodiment, as shown in Figure 7B, the proximal end 709, including cartridge seating area 705, has overall maximum height 750 of approximately 86.2 mm. In one embodiment, as shown in Figure 7C, proximal end 709 has an overall maximum length 755 of approximately 237.7 mm. And, as shown in Figure 7D, in one embodiment, proximal end 709 has an overall maximum width 760 of approximately 108.6 mm. As shown in the figures, the cartridge seating area comprises a cavity having at least one gear mechanism, wherein the cavity is designed to mate with, and physically compliment, a disposable testing cartridge.

Figure 8 is a schematic diagram showing the individual components of one embodiment of the disposable cartridge as used in the hand-held explosives detection system of the present invention. Now referring to Figure 8, disposable cartridge 800 comprises, in one embodiment, top cartridge cover 805, reagent containers 810, main cartridge enclosure 815, substrate reel 820,

and bottom cartridge cover 825. The individual components of the disposable cartridge 800 will be described in greater detail below with respect to Figures 9A-9D and 10A- 1OG.

In one embodiment, as shown in Figures 9A and 1OA, the disposable cartridge is readily available as a complete unit that can be disposed of by the operator. It should be noted herein that the individual components are secured to each other, or integrally fitted by means known to those of ordinary skill in the art such that the components form a complete cartridge.

In order to ensure that the disposable cartridge and its components are chemically inert, the components that are exposed to chemicals are made of polypropylene and glass filled. The glass filling increases the structural strength of the components. Figure 9A is a depiction of the front side of one embodiment of a disposable cartridge, further showing a pressure release interface, a sampling area of interest, and an analysis area of interest. Now referring to Figure 9A, compact disposable cartridge 900 comprises a substrate reel or cassette (not shown) having individual "areas of interest" on the substrate, including sampling area of interest 905 and analysis area of interest 910. It should be noted that any number of areas of interest may be comprised in one substrate reel, depending on the requirements of the user. In one embodiment, each area of interest is on the order of 7mm x 10mm. A new collection area of interest is used for each test. In addition, a space of approximately 1 mm is left between each area of interest to prevent cross-contamination. Further, as described in greater detail below, a new area of interest is only advanced after rotation of the turning mechanism referred to above. The used/tested areas of interest are wound on the gear pulley, which collects used areas of interest. In one embodiment, the system displays the number of tests remaining while the system is in use and also warns the operator by a message indication to change the cartridge when the intended number of uses is exhausted.

In a first embodiment, the substrate reel comprises gauze pasted on a polypropylene based cellophane tape. Preferably, the gauze is substantially pure cotton and has a network of sub-yarns that facilitate the capture of an available trace particle. In addition, since the loose yarn network stretches, the color appearance is amplified upon reaction with a chemical reagent.

It should be noted that polypropylene -based cellophane tape is used because it is chemically inert to the chemical reagents that will be dispensed on the area of interest just after the sampling process in completed. It should thus be understood by those of ordinary skill in the art that any chemically inert material that achieves the same purpose may be used.

In another embodiment, the substrate reel is further coated with a layer of acrylic based adhesive material on the order of 25 to 50 microns thick. The acrylic-based adhesive material is employed since it does not dry out even when exposed to air for long periods of time. This ensures that any picked up trace particles attach to the area of interest upon impact. Further, an advantage of the acrylic-based glue layer on the cellophane tape material is that it is naturally charged with electrostatic potential. Thus, any particles of interest that are picked up will impact the area of interest with both velocity from the air flow and some electrostatic potential as well.

In another embodiment, the substrate reel, and thus, the areas of interest are pre -treated with at least one chemical reagent. In one embodiment, the reagent is in powder form after being deposited onto the substrate reel. In one embodiment, the last reagent in a sequence of reagents is deposited onto the substrate reel in powder form. As will be described in further detail below, the use of one of the chemical reagents in powder form enables the use of a micro-dispensing technique. In addition, as described above, the micro-reagents have a long shelf life and can be stored for up to one year, unlike conventional chemical reagent configurations. The substrate reel described above is detailed pending Israeli Patent Application No

187203 entitled "Matrix for Detection/ Analysis of Residue", filed on November 6, 2007, and assigned to Aphelion Ltd, which is incorporated herein by reference.

In a second embodiment, the substrate reel comprises a chemically coated, black-line printed Benck Kot® paper. Benck Kot® paper (hereinafter, "BKTPP") is a commercially available paper, which is a chemical paper sheet laminated with a polyethylene film (or other optically transparent film) on one side. In one embodiment, the black lines are printed on the BKTPP poly film side.

Preferably, the BKTPP is comprises a poly film having both a front side and a back side, further comprising an absorption paper layer on the back side, that facilitates the capture of available trace particles. In addition, since the absorption paper stretches, the color appearance is amplified upon reaction with a chemical reagent. It should be noted that the poly film of the BKTPP is chemically inert to the chemical reagents that will be dispensed on the area of interest just after the sampling process is completed (described in further detail with respect to operational steps below). It should thus be understood by those of ordinary skill in the art that any chemically inert material that achieves the same purpose may be used.

In another optional embodiment, the BKTPP reel, and thus, each individual area of interest, is pre -treated with at least one chemical reagent. In one embodiment, the reagent is in powder form after being deposited onto the BKTPP reel. In one embodiment, the last reagent of a sequence of reagents is deposited onto the BKTPP reel in powder form. As will be described in further detail below, the use of one of the chemical reagents in powder form enables the use of a micro-dispensing technique. In addition, the micro-reagents have a longer shelf life and can be stored for up to one year, unlike conventional chemical reagent configurations.

Referring back to Figure 9A, disposable cassette 900 also comprises pressure release interface 915. Preferably, the cartridge is placed in the hand-held detection system of the present invention. Once the cartridge is exhausted, which is determined by the lack of fresh areas of interest as described above, the cartridge is removed from the system and a new cartridge is loaded into the system. The pressure release interface, shown in Figure 9A as 915, is employed to remove the cartridge from the system.

Figures 9B, 9C and 9D are diagrams showing the relative dimensions of the pressure release module that is removably connected to pressure release interface 915. In one embodiment, as shown in Figure 9B, pressure release module 916 has an overall height 950 of approximately 27 mm. In one embodiment, as shown in Figure 9C, pressure release module has an overall length 955 of approximately 81.5 mm. In one embodiment, as shown in Figure 9D, pressure release module has an overall width 960 of approximately 66.5 mm. In one embodiment, the pressure release module is designed to facilitate safe removal of the used disposable cartridge, since at the end of the testing life of the cartridge there is some residual liquid in the reagents container. The residual liquid in the containers will have some internal pressure. If the cartridge is abruptly removed from the system, the residual pressure in the reagents container will cause the liquids to spill out and may result in damage to the internal system components. The pressure release module is thus placed into the disposable cartridge at pressure release interface 915 to release the residual pressure and serve as a handle to remove the used cartridge from the main system. The pressure release module can be removed with the cartridge and disposed of with the cartridge.

Figure 1OA is a depiction of the back side of one embodiment of a disposable cartridge 1000 as shown in Figure 8, showing a chemical reagents container 1005 having at least one container opening 1010 for reagent dispensing. The dispensing orifices 1010 are used for

depositing chemical reagents onto the area of interest. In one embodiment, the orifices 1010 are punctured by a dispensing system interface (not shown) such that the reagent from the reagents containers (described below) are driven by their inherent pressure to the dispensing valves (not shown). Figures 1OB and 1OC are expanded views of an individual reagents container 1005 and the internal components of the individual reagents containers 1005, respectively. In one embodiment, each individual reagent container is a hollow polypropylene cylinder having a length of approximately 72 mm and a diameter of approximately 9 mm. As shown in Figure 1OB individual reagent container 1005 further comprises dispensing orifice 1010. It should be noted that the chemical reagents container 1005 may contain any number of separate columns for housing separate reagents and thus any number of corresponding container openings 1010 for reagent dispensing. In one embodiment, each reagent container 1005 contains a maximum of 2000 μL of test fluid. In another embodiment, each reagent container 1005 is filled to its maximum to account for built-in test capability and minor evaporation of the test fluid. The test fluids in the container are preferably sealed to prevent leakage and are stored under pressure to facilitate micro-dispensing. In one embodiment, the pressure within the reagents container is achieved using a spring.

Now referring back to Figure 1OA, disposable cartridge further comprises a drive pulley bobbin and paper bobbin 1016. Figure 1OD illustrates one embodiment of a gear or turning mechanism that is located on the hand-held explosive detection system. In one embodiment, the turning mechanism is stepper motor gear assembly that is enabled via a drive pinion 1025 that is mounted on a stepper motor 1030.

The substrate is spooled around paper bobbin 1016 and linked to the internal gear via its path. As the stepper motor is rotated, the rotational movement is transferred to the self-aligned driven pulley. The substrate is then pulled from the paper bobbin 1016 along its path. The paper bobbin 1016 has teeth that protrude outside the disposable cartridge. These teeth will be engaged with the drive gear of the stepper motor, when the cartridge is inserted into the system. This enables the substrate reel to change the area of interest for each movement of the stepper motor 1030. As mentioned above, each area of interest used in the previous test is wound on the gear pulley, which collects and spools the used areas of interest.

Figures 1OE, 1OF, and 1OG are schematic diagrams showing dimensional details of the disposable cartridge described with respect to Figure 8. In one embodiment, as shown in Figure 1OE, disposable cartridge 1000 has overall maximum height 1050 of approximately 43.5 mm. In one embodiment, as shown in Figure 1OF, disposable cartridge 1000 has an overall maximum length 1055 of approximately 81.5 mm. And, as shown in Figure 1OG, in one embodiment, disposable cartridge has an overall maximum width 1060 of approximately 85 mm.

Figure 11 is a flow chart describing the operational steps of one embodiment of the handheld explosive detection system of the present invention. To set-up the explosive detection system, the replaceable battery pack is gently slid into the battery pack area. To begin a screening operation, in step 1101, the hand-held explosive detection system of the present invention is powered on. Once the power button is on, power is supplied to the entire system. In step 1103, the system performs a Built-in-Test (BIT) for confirmation of the internal module's functionality. If the BIT is successful, then the system displays a "Scan Ready" message on the display. If the BIT is unsuccessful, then the system displays a "System Fail" message on the display. In one embodiment, the BIT identifies the system failure and displays this on the HFRED display.

It should be noted herein that the area of interest of the substrate is already positioned in the sample collection area for collecting trace particles, since the reel is advanced at the end of each previous test. If a "Scan Ready" message is displayed, the operator proceeds to step 1105, where a subject is positioned in a designated location, such as at a security checkpoint in an airport. The operator then initiates the scan in step 1107 by depressing the start test push button. In step 1109, the operator then moves the hand-held explosive detection system along and on the scanned surface, such as the subject's clothing, skin, and/or belongings for sample collection. While the operator is scanning the subject, a sampling sub-system initiates the "sniffing" process, which allows the system to collect existing microscopic traces. As structurally described above with respect to Figures 5A and 5B, and described in greater detail below, the microscopic trace particles are collected up by the scanning interface, which, in one embodiment, is a suction inlet. Further, the raised surface bumps on the scanning interface allow for agitation of the surface in addition to scanning as much area as possible on the scanned subject to ensure

that a maximum sample portion is obtained. The air flow moves in a direction opposite the screened subject and towards the lower side of the handle of the system.

Referring now to Figure 12, a schematic diagram of one embodiment of a sampling subsystem as used in the hand-held explosive detection system of the present invention is shown. In one embodiment, sampling sub-system 1200 comprises at least one air inlet or suction inlet 1210, at least one air outlet 1220, tube 1230, and area of interest or collection substrate 1240. As shown in Figure 12, in one embodiment, sampling sub-system 1200 comprises two air outlets 1220a and 1220b. A miniature DC motor (not shown), a vacuum propeller (not shown), and tubing (not shown) are removably connected the outlet (not shown) of suction inlet 1210. The vacuum system is employed to create an air flow of tens of liters/minute at suction inlet 1210. In one embodiment, the volume of air drawn into the system is 60 liters/minute.

In an optional embodiment, the sampling sub-system further comprises means for noise reduction and a shock absorber to minimize the noise and vibrations to both the subject and operator during the sampling process. In order to effectuate noise reduction, in one embodiment, the outer body is comprised of ABS plastic. Optionally, the vacuum pump, which aids in the suction process, may be framed and mounted with a silicon rubber support in a groove in the main enclosure to reduce space. This will effectively reduce noise and minimize shock effects.

In one embodiment, and as described above, a disposable cartridge (not shown), comprises a substrate reel (not shown) and area of interest 1240 and reagent containers (not shown). The disposable cartridge is located proximate to the sampling sub-system for subsequent particle collection and analysis. A new area of interest 1240 is used for each test.

In one embodiment, the disposable cartridge is located such that the area of interest 1240 is located at the center end of the sampling sub-system 1200. As the vacuum system begins the air flow, air from suction inlet 1210 is drawn on the collection substrate's active area of interest 1241. Area of interest 1241 then attaches to the end 1242 of the sampling sub-system and seals end 1242 to ensure proper flow distribution. In one embodiment, the flow of air is divided symmetrically between air outlets 1220a and 1220b, thus enabling a possible trace particle to be deposited and attached symmetrically around and at approximately the center of area of interest 1241. In one embodiment, tube 1230 is a copper tube. As is well-known to those of ordinary skill in the art, if the copper tube is electrically grounded, a near-"Faraday Cage" is formed. In

using a "Faraday Cage", the present invention is advantageous in that it prevents electrostatic obstacles in the copper tube from capturing any picked up trace particles. In addition, in one embodiment, the internal surface of copper tube 1130 has a surface that is finished to a scale on the order of a few micrometers. Copper surface finishing techniques are well-known to those of ordinary skill in the art, including but not limited to electro-polishing or electroplating, and will not be described in detail herein. Since a 1 microgram explosive trace sample has a diameter on the order of 100 micrometers, the internal surface finish of the copper tube 1130 prevents mechanical obstacles in the copper tube from capturing any available trace particles. Stated differently, both the "Faraday Cage" and finished internal surface of copper tube 1230 helps propagate the air flow towards area of interest 1241.

Trace explosives, in the form of microscopic particles, are trapped on the collection substrate during the sniffing process via the suction inlet.

In step 1111, the substrate reel is advanced so that the area of interest is positioned proximate to the back of the disposable cartridge for chemical reagent analysis and color detection. Thus, once the suction process is completed, the substrate reel, and thus the area of interest potentially containing microscopic particles, is advanced from the sampling area to the analysis area. As described above, the substrate is spooled around the paper bobbing and linked to the internal gear via its path such that when the internal gear is rotated the substrate is pulled from the paper bobbin along its path. In step 1113, a background color (RGB) measurement is made for a reference point.

A subsequent analysis of the sample that may be present on the chemical substrate is performed, and involves micro-dropping a sequence of chemical reagents on the collection substrate.

Conventional spectroscopy techniques, such as IMS, suffer from saturation issues. For example, if a sample size or sampled quantity is too large, the detection system becomes saturated. Since the system becomes active after saturation, and requires increased analysis time, the next measurement would only be possible after the system is finished with that particular cycle. In one embodiment, the hand-held explosive detection system of the present invention advantageously uses the chemical reagents for color detection and determination of a color appearance. As the size of the analyzed particle or sample portion increases, the color

appearance strengthens and becomes easier to detect. Thus, the size of the particle does not affect detection time and there are no saturation limitations.

Analysis is begun by dropping at least one chemical reagent on the area of interest. In one embodiment, the reagents are micro-dropped onto the area of interest. In one embodiment, the actual volume of chemical reagent that is dispensed is 1 μL to 2 μL. In one embodiment, the dropping approach is to drop one drop directly on top of the other in a sequence of chemical reactions. The small dispensed volume creates a color indication on the area of interest on the order of 5mm in diameter.

As stated above, the system is capable of detecting the presence of several varieties of explosives, including, but not limited to military, commercial, and improvised explosives. In one embodiment, the present invention is capable of detecting the presence of polynitro aromatics, such as but not limited to TNT, Tetryl, TNB, and picric acid and its salts. In another embodiment, the present invention is capable of detecting the presence of nitrate esters and nitramines, such as but not limited to RDX, PETN, SEMTEX, C4, Smokeless Powder, Dynamite, and Nitrocellulose. In another embodiment, the present invention is capable of detecting the presence of nitrate salts, such as but not limited to ammonium nitrate, potassium nitrate, and urea nitrate. It should be noted herein that the present invention can be used to detect the presence of other chemical groups and thus, it should be understood to one of ordinary skill in the art that modifications to the present invention may be made to allow for increased detection capability. In principal, and in conventional systems, three chemical reagents are employed to enable detection of all above-mentioned groups of explosives. For example, Reagent 1 is employed to detect the presence of polynitroaromatics, Reagents 1 and 2 are employed to detect the presence of nitrate esters and nitramines, and Reagents 1, 2, and 3 are employed to detect nitrate salts.

In one embodiment of the present invention, several chemical reagents are employed. In one embodiment, Reagent Ia is 90% DMSO plus 10% methanol. In one embodiment, Reagent Ib is tetra-butyl ammonium hydroxide. In one embodiment, Reagent 2a is aqueous 4% Sulfanilamide with 10% Phosphoric Acid. In one embodiment, reagent 2b is 0.4% NEDA with methanol. In one embodiment, Reagent 3.00 is a 2% zinc solution with hexane.

In one embodiment, Reagents Ia, Ib, and 2a are in liquid or aqueous form, while reagents 2b and 3 are used in powdered form that is coated on the substrate. In one embodiment, the combination of Reagents Ia and Ib are employed for the detection of TNT and like compounds.

In one embodiment, the combination of Reagents Ia, Ib, 2a, and 2b are employed for the detection of RDX and like compounds. In another embodiment, the combination of Reagents 2a, 2b, and 3 are used for the detection of nitrates and like compounds.

Almog Kraus, and Glattstein, "ETK-AN OPERATIONAL EXPLOSIVE TESTING KIT", Journal of Energetic Materials, Vol. 4, 159-167 (1986) is herein incorporated by reference in its entirety.

Referring back to Figure 11, in one embodiment, in step 1115, Reagents are micro- dispensed in sequence onto the area of interest to detect the explosive groups as specified above.

In step 1117, the explosive detection system then detects whether a color appears as a result of a chemical reaction between the chemical reagents and the trapped explosive traces on the collection substrate, via the color detection sub-system. The color appearance may be immediate or may take up to fifteen seconds. This is generally dependent upon temperature; for example, at higher temperatures, the color reaction is usually faster than at lower temperatures.

In one embodiment, the color appearance at the area of interest is analyzed by a low cost colorimeter that provides a color appearance indication only. Thus, the colorimeter provides an electro-optical front end detection system. In one embodiment, the detector is placed just behind the opposite side of the substrate and on the other side of the chemical dispensing side of the cellophane tape on the substrate reel. In one embodiment, the colorimeter combines three photodiodes having red, green and blue dye-based filters. Based on the theory of trichromacy, three values, in this case R, G, and B, are necessary and sufficient to describe any color.

In a color measurement application, a white light source, such as an incandescent lamp or white LED is used to illuminate the sample. Reflected light from the sample is directed to detector, either through a lens or via close proximity to the sample. In the case of a colored source, light from the source is directly incident on the detector. The three outputs from the detector are then processed to determine color, or rather, the presence of color.

A temperature fluctuation may cause light fluctuations while illuminating the area of interest. Further, the appearance of color is time dependent due to the chemical reaction of the reagents with the trace particles. Still further, non-uniformity of the substrate's light reflection properties, since the substrate is made of chemical yarns may also affect the outcome of the system. In order to overcome these natural uncertainties, the present invention detects color by a relative change approach that insures detection to be almost independent of light intensity.

It should be noted herein that a substantial advantage of the present invention is that it does not identify the explosive substance, but rather detects the presence or absence of color, where the presence of color is an indicator of the presence of a chemical of interest. This advantageously allows for higher throughput of the system, because the complex chemical identification analyses are not performed, as with conventional systems.

Referring back to Figure 11, in step 1119, the results of the presence of color are then translated to the operator in the form of an audio and/or visual "pass/no pass" or "go/no go" indicator. As shown in Figure 13, in one embodiment, the hand-held explosive detection system of the present invention further comprises a display 1305 and two LED indicators 1310. In one embodiment, one LED indicator 1310 is red to indicate a "no go" or "no pass" and the other LED indicator 1310 is green to indicate a "go" or "pass". If an explosive trace is detected, the audible alarm (not shown) will sound. If no explosive trace is detected, the audible alarm will not sound.

In one embodiment, the display 1305 is capable of displaying at least one message. In one embodiment, the message is selected from, but is not limited to, the following list: "Tests Done/Tests Left", "BIT Fail", "Replace Battery", "Insert Cartridge", "Ready", "Go", "No Go", "Change Cartridge", "Temperature Out of Range", and "Switch Off System".

If the system displays a "Go", then steps 1115, 1117, and 1119 are repeated to ensure that no other threat is present. Specifically, but not limited to such embodiment, reagent 2a is micro- dispensed onto the area of interest, which already contains a powdered form of Reagent 2b. Thus, the reaction of Reagents 1 , 2a, and 2b and any trace particle of interest is employed to detect nitrate esters and nitroamines, such as but not limited to RDX. And finally, Reagents 2b and 3, which are both contained in powdered form on the area of interest are activated by the two initial reactions and can thus be used to detect the presence of inorganic nitrates such as but not limited to potassium nitrate. In one embodiment, Reagent 3 is in powdered form because it has a tendency to block the micro-dispenser, leaving an incomplete analysis. Thus, the chemical reactions, in one embodiment, are not mutually exclusive, but rather additive.

Referring back to Figure 11, if a subject is issued a "pass" or "go", in step 1119, then the subject is cleared and allowed to pass through the security checkpoint. If a subject is issued a "no pass" or "no go", then the subject is directed, in step 1119, to a second stage screening process. The second stage screening process may comprise any other

security screening process as are well-known to those of ordinary skill in the art for verifying whether a threat is present and/or identifying the nature of the potential threat material.

In one embodiment, the hand-held explosive detection system of the present invention further comprises a metal detection capability. It should be understood by those of ordinary skill in the art that the electronic functions of the hand-held metal detector, in one embodiment, are controlled via an internal printed circuit board.

The above examples are merely illustrative of the many applications of the system of present invention. Although only a few embodiments of the present invention have been described herein, it should be understood that the present invention might be embodied in many other specific forms without departing from the spirit or scope of the invention. Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive, and the invention may be modified within the scope of the appended claims.