System and method for selective insect control using microwave radiation

Abstract

A system and method for chemical-free insect control using microwave radiation at the insect's resonant frequency ±250 MHz. The insect control system includes one or more RF shielding layers supported on a folding frame and configured to form a canopy over an infested object, such as a bed. A mobile cart placed adjacent to the insect-infested object houses a microwave generator, a power module, a control module, and microwave transmission components. The microwave radiation at the insect's resonant frequency ±250 MHz rapidly increases the temperature inside the insect's cuticle through flash heating, killing the insect while minimizing temperature rise in the infested object.

Description

Related Applications

[0001] This patent application claims priority to commonly assigned U.S. Provisional Patent Application No. 63 / 428,806, entitled "Device and Method for Selective Insect Control Using Microwave Radiation," filed November 30, 2022. The disclosure of the prior application is considered part of this patent application and is incorporated by reference in its entirety into this patent application. FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] none. [Technical Field]

[0003] The present disclosure relates to systems and methods for selectively killing insects using microwave radiation by irradiating the target insects with microwaves at frequencies close to the resonant frequency of the target insects while minimizing the impact on the infested object, and more particularly, but not exclusively, the present invention relates to methods and apparatus for selectively killing bed bugs. [Background technology]

[0004] The common bed bug, Cimex lectularius, belongs to the Cimicidae insect family. Increased global travel over the past decade has led to increased bed bug infestations in the United States and around the world. Bed bugs can be unintentionally introduced on furniture, sofas, luggage, and other materials, with apartments, college dorms, hotels, and motels tending to have the most severe infestations (Cranshaw et al., 2013). Bed bugs feed on human blood, causing itchy bites in their hosts. Bed bugs are a public health pest and rapidly multiply. These insects feed in the dark, usually in the middle of the night, using carbon dioxide in exhaled air and body heat to locate hosts (Miller and Polanco). Bed bugs probe the skin several times before initiating a blood meal, and multiple bites from the same insect can occur. Bed bugs feed for approximately 5 to 10 minutes every 3 to 7 days. A single female louse will lay approximately 120–200 eggs over its roughly one-year lifespan, provided it feeds regularly. Egg mortality is low, with a hatching rate of approximately 97%. At room temperatures between 70–90°F (approximately 21–27°C), eggs hatch in approximately 6–10 days, progress through five nymph stages, and mature into adults in approximately 40 days. At each stage, the nymphs shed their exoskeleton (also referred to as molting), and they require blood feeding to successfully molt. Both male and female adults also require regular blood feeding to reproduce. Bed bug eggs are approximately 1 mm in size. Stage 1 nymphs are approximately 1.5 mm in size, while stage 5 nymphs are approximately 4.5 mm in size. (U.S. EPA) Adults are approximately 5–7 mm in size. Bed bugs are typically found in large numbers near beds. They are most often found in clusters in furniture such as bed frames, mattresses, lamps, and nightstands, behind pictures hanging on the wall, and in other crevices next to the bed. Large bed bug populations can become widely dispersed throughout a room. The movement of insects to adjacent rooms can occur through air ducts connecting rooms, or through holes in walls for electrical wiring, electrical outlets, and plumbing.

[0005] Bed bugs can be controlled and eliminated using insecticides, but they are not very effective because they require direct contact with the insects. Bed bug eradication is difficult, requiring simultaneous treatment of all infested areas, such as every room in an apartment, to prevent bed bug migration. Because eggs are generally impervious to insecticides, repeated chemical applications are required to ensure effective treatment after the eggs hatch. Insecticides used to control bed bugs are primarily pyrethroids, including bifenthrin, lambda-cyhalothrin, deltamethrin, beta-cyfluthrin, and chlorfenapyr (Cranshaw et al.). A sprayer with a fine-tipped nozzle is used to inject liquid insecticides deep into cracks and crevices. Aerosols containing pyrethrins or permethrin, or sprays with non-residual insecticides such as pyrethrins or tetramethrin, are ineffective at controlling bed bugs because they kill only a few insects that come into direct contact with a sufficient amount of the insecticide. Aerosols and sprays do not penetrate cracks and crevices well enough. Research also suggests that bed bugs are developing resistance to some insecticides.

[0006] High-temperature treatment is considered the primary non-chemical method for eliminating bed bugs (Cranshaw et al.). Specialized equipment used by professional pest control professionals forces hot, dry steam heat into infested areas. This method is particularly effective for treating bed frames, box springs, and mattresses, where insecticides are ineffective. To eliminate bed bugs hiding in adjacent crevices, the surface temperature of the treated area must reach approximately 140-150°F. Steam treatment is time-consuming, sometimes requiring 15 seconds or more to treat approximately 1 square foot (approximately 0.4 square meters). Condensation or excessive moisture in the treatment room can lead to mold growth, damaging books, paintings, clothing, and other items in the room. Dry-heat treatments can also damage books and other furniture in the room.

[0007] U.S. Patent No. 8,943,744, "Microwave Energy Apparatus and Method for Insect and Pest Control," discloses an apparatus and method for treating sites infested with insects, such as bed bugs, and other small pests using microwave energy. The apparatus includes a microwave energy source, a transmission element, and an antenna connected to a power source and power control. The apparatus may also include an isolator to protect the microwave energy source. According to the disclosure, microwave energy is absorbed by the insects, their eggs and larvae, or small pests, killing them and causing their body heat, while having little or no effect on surrounding fabrics, mattress materials, or wood. A typical household microwave magnetron operating at 2.35 GHz to 2.65 GHz can be used as the microwave energy source. The disclosed insect control method includes forming a microwave energy beam, directing the beam at the infested site, scanning the infested site, determining whether the treatment was effective, and repeating the scanning step. No details regarding the duration of exposure are provided. It is well known that treating an infected area as disclosed will increase the temperature of furniture, books, clothing, bedding and other materials exposed to the incident radiation, similar to heating food in a domestic microwave oven, thereby reducing their value or adversely affecting their suitability for certain uses.

[0008] Tyrpak (2016) studied the effects of microwave energy on bed bug eggs, larvae, and adults by placing eggs, larvae, and adults on various substrates in a 700W, 2.45GHz microwave oven. For eggs, bed bug eggs were placed on filter paper, placed in small Petri dishes, and microwaved for treatment times ranging from 5 to 35 seconds. The eggs were then observed for two weeks. Results suggested that a treatment time of at least 25 seconds was necessary to destroy the eggs and prevent hatching. Larvae and adults (including fed male and female adults) were placed in a 250ml beaker and microwaved for up to 30 seconds. The insects were then observed for at least 24 hours. Results indicated that effective treatment times for adults and stage 4 and stage 5 larvae were approximately 26 seconds, and for stage 1 larvae, approximately 44 seconds. Only approximately 10% of recently fed insects "exploded" when exposed to microwave energy. In another test, larvae and adults were placed inside books and microwaved for 30, 60, and 90 seconds. In this case, the effective treatment times for larvae and adults ranged from 60 to 90 seconds. After 90 seconds, the books were found to be damaged, with melted binding, crumpled pages, and burn marks. The books continued to radiate heat after being removed from the oven for approximately two minutes.

[0009] There is a need for chemical-free systems and methods for the rapid eradication of bed bugs and other insects. Traditional methods of eradication involve dry heat and insecticides. These traditional methods are unsuitable for use in hotels and cruise ships because they produce chemical odors that alert guests to the insect infestation problem. Furthermore, in military operations, bed bug infestations have been shown to have a significant impact on morale. Military anchorages, both for land and maritime operations, face similar challenges. Although bed bugs do not transmit disease, the economic impact is significant.

[0010] Although the use of microwave energy to eradicate bed bugs has been reported, the reported methods and devices raise the temperature of bed bug-infested materials or objects, resulting in partial or complete destruction of these materials. There is a need for a device and method that uses microwave energy to selectively eradicate bed bugs and other insects, such as termites, without damaging infested materials such as mattresses, walls, and furniture, and at a low "per treatment" cost. Summary of the Invention

[0011] In some implementations, the insect control system may include a collapsible canopy frame configured to be positioned above an insect-infested object, one or more RF shielding curtains supported by the canopy frame and configured to encase the insect-infested object, one or more microwave horn antennas supported by a plurality of roof support members on the canopy frame and positioned a predetermined distance above the insect-infested object, and a portable cart movably positioned outside the RF shielding envelope and including a microwave generator and a control system. In some implementations, the control system may be configured to one or more of: activate the microwave generator to generate microwave radiation at a frequency within ±250 MHz of a resonant frequency of the insects; transmit microwave radiation from the microwave generator to the one or more horn antennas; or direct the microwave radiation toward the insect-infested object.

[0012] In some implementations, the one or more RF shielding curtains may include a first curtain configured to encase an insect-infested object and a second curtain positioned outside the first curtain. In some implementations, the one or more horn antennas may each include a flared end, and the predetermined distance between the infested object and the flared end of the horn antenna may be approximately 2 feet (approximately 60 cm). In some implementations, the one or more horn antennas may include a pyramidal horn antenna. In some implementations, the one or more horn antennas may be configured to connect to one or more swivel couplings supported by the multiple roof support members.

[0013] In some implementations, the portable cart can include multiple interior compartments, at least one of which can be configured to house one or more horn antennas or one or more RF shielding curtains. In some implementations, the portable cart can include a control system configured to communicate with application software on a smart device to remotely operate the portable cart. In some implementations, the portable cart can include a rechargeable battery power system.

[0014] In some implementations, an exemplary method for selectively eliminating insects within an insect-infested object may use microwave radiation while minimizing impact on the insect's host. In some implementations, the method may begin with providing a decontamination system that encases the insect-infested object. In some implementations, the system may include one or more RF shielding curtains configured to encase the infested object, where the one or more RF shielding curtains may be supported by a foldable canopy frame. In some implementations, the exemplary decontamination system may include a portable cart that includes a microwave generator that may be movably positioned outside the RF shielding curtains. In some implementations, the exemplary decontamination system may be configured to transmit microwave radiation from the microwave generator toward the insect-infested object.

[0015] In some implementations, an exemplary method for selectively controlling insects in an insect-infested object may further include selecting a first incident microwave radiation frequency that may be within ±250 MHz of the resonant frequency of the target insect, and continuing to expose the insect-infested object to the microwave radiation for a first predetermined first treatment time. In some implementations, the first incident microwave radiation frequency may be between about 10 GHz and about 15 GHz. In some implementations, the first incident microwave radiation frequency may be about 12.5 GHz. In some implementations, the first predetermined treatment time may be between about 5 seconds and 30 seconds. In some implementations, the exemplary method for selectively controlling insects in an insect-infested object may further include inspecting the infested object after the first treatment time.

[0016] In some implementations, the repeating step can include exposing the infested object to microwave radiation at a second frequency that is higher than the first frequency. In some implementations, the repeating step can include exposing the infested object to microwave radiation for a second treatment time that is longer than the first predetermined treatment time. In some implementations, the inspecting step can include inspecting the infested object using either visual inspection, inspection with a thermal imaging camera, or a combination of both.

[0017] In some implementations, an insect control system may include a collapsible canopy frame configured to form an inflated canopy frame over an insect-infested object, a prefabricated microwave shield (RF shield) configured to encase the inflated canopy frame, and one or more microwave horn antennas supported by multiple roof support members on the canopy frame. In some implementations, the one or more horn antennas may be positioned a predetermined distance above the infested object. In some implementations, an example insect control system may include a portable cart movably positioned outside the prefabricated microwave shield. In some implementations, the portable cart may include an air pump for inflating the collapsible canopy frame and a microwave generator. In some implementations, an example insect control system may include a control system configured to perform one or more of: operating a microwave generator to generate microwave radiation at a frequency within ±250 MHz of a resonant frequency of the insect; transmitting microwave radiation from the microwave generator to one or more horn antennas; or directing microwave radiation at an object infested with insects.

[0018] In some implementations, the microwave radiation can be characterized by a frequency of about 10 GHz to about 15 GHz. In some implementations, the microwave radiation can be characterized by a frequency of about 12.5 GHz. In some implementations, the one or more horn antennas can include pyramidal horn antennas. In some implementations, the one or more horn antennas can be configured to be connected to one or more swivel couplings supported by multiple roof support members.

[0019] Other features and advantages of the present disclosure will be set forth in part in the following description and the accompanying drawings, in which preferred aspects of the present disclosure are described and shown, and in part will become apparent to those skilled in the art through examination of the following detailed description, taken in conjunction with the accompanying drawings, and will be learned through the practice of the present disclosure. The advantages of the present disclosure may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. [Brief explanation of the drawings]

[0020] The foregoing aspects and many of the attendant advantages of the present disclosure will be more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings. [Figure 1A] 1A-1H show schematic diagrams of various components of an exemplary insect control system, according to some implementations, with FIG. 1A being a perspective view of a collapsible canopy configured to encase a pest-infested object (bedding) to be treated. [Figure 1B] FIG. 1B is a perspective view of the folding canopy in a folded state. [Figure 1C] Figure 1C is a perspective view of the canopy with internal and external microwave shields; [Figure 1D] FIG. 1D is a side view of the canopy with the inner shield rolled up. [Figure 1E] FIG. 1E is another perspective view of the canopy showing the outer microwave shield with the inner shield rolled up. [Figure 1F] FIG. 1F is a perspective view of a fully assembled canopy with a mobile cart housing a microwave generator. [Figure 1G] FIG. 1G is a perspective view of an exemplary insect control system for disinfecting dormitory beds. [Figure 1H] FIG. 1H is another perspective view of an insect control system for disinfecting beds in a dormitory-type room. [Figure 2A] 2A-2C show perspective views of an exemplary mobile cart housing a microwave generator in an insect control system, according to some implementations, with FIG. 2A being a perspective view of the cart with the compartment panel closed. [Figure 2B] FIG. 2B is a perspective view showing the compartment housing the microwave shielding curtain and horn antenna. [Figure 2C] FIG. 2C is a perspective view showing the compartment that houses the microwave generator and auxiliary components. [Figure 3A] 3A-3D show perspective views of various components of an exemplary insect control system, according to some implementations, with FIG. 3A being a perspective view of an inflatable frame configured to support a microwave horn antenna above an infested bunk of a bunk bed. [Figure 3B] FIG. 3B is a perspective view showing an inflatable frame with a mobile cart housing a microwave generator positioned adjacent to a bunk bed. [Figure 3C] FIG. 3C is a perspective view of a prefabricated microwave (RF) shielding member. [Figure 3D] FIG. 3D is a perspective view of an RF shield placed on an inflatable frame to encase an infested bunk bed. [Figure 4] FIG. 4 shows a schematic diagram of an example method for insect control using microwave radiation, according to some implementations. [Figures 5A-5C] 5A-5C show exemplary simulation results of power deposition maps inside a bed bug at various microwave incidence frequencies, according to some implementations.

[0021] All reference numbers, identifiers, and callouts in the figures are incorporated herein by this reference as if fully set forth herein. Failure to number elements in the figures is not intended as a waiver of any rights. Non-numbered references may also be identified by the alphabetic letter of the figure or appendix.

[0022] The following detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the disclosed systems and methods may be practiced. These embodiments, which may be understood as "examples" or "options," are described in sufficient detail to enable one skilled in the art to practice the invention. The embodiments may be combined, other embodiments may be utilized, or structural or logical changes may be made without departing from the scope of the invention. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of the invention is defined by the appended claims and their legal equivalents.

[0023] The terms "a" or "an" are used to include one or more, and the term "or" is used to refer to a non-exclusive "or" unless otherwise specified. Additionally, terms used herein and not specifically defined should be understood to be for descriptive purposes only and not limiting. Unless otherwise specified in this disclosure, for purposes of interpreting the scope of the term "about," the margin of error associated with a disclosed value (e.g., dimension, operating condition, etc.) is ±10% of the value set forth in this disclosure. The margin of error associated with a value disclosed as a percentage is ±1% of the stated percentage. The word "substantially" used before certain words includes the meanings "to a significant extent to the specified degree" and "to a large extent, but not completely, to the specified degree." "Autonomous" means "without or minimal intervention by a professional technician or equipment operator." DETAILED DESCRIPTION

[0024] Specific aspects of the present invention are described in detail below to explain the architecture, principles, and operation of the disclosed methods and systems. However, various modifications are possible, and the scope of the present invention is not limited to the exemplary aspects described.

[0025] 1A-1H show schematic diagrams of an exemplary insect control system 100, according to some implementations. The exemplary insect control system can be configured to disinfect bedding, equipment, and other items in hospitals, university dormitories, hotels, hostels, motels, military bedding, military tents, and the like. The exemplary system 100 can be configured to treat items and areas infested with insects, such as bed bugs, by exposing them to microwave radiation. The exemplary system 100 can include a collapsible canopy frame 101 that can be sized to cover or encase a bed 107, for example, a standard twin bed, a standard twin XL bed, or other size bed. The bed 107 can include a mattress 108 that may be infested with insects, such as bed bugs. For example, the exterior dimensions of the exemplary canopy frame 101 can be approximately 96 inches (L) x approximately 48 inches (W) x approximately 52 inches (H). The canopy frame 101 may include multiple legs or supports 102 supporting a foldable upper frame 103. The upper frame 103 may include multiple foldable horizontal roof support members 104 extending across the entire width of the frame 103. The upper frame 103 may be attached to the legs 102 using multiple foldable support members 105. Each of the multiple legs 102 may be configured to connect to casters 106, allowing the canopy frame 101 to be moved around a bed to be disinfected or within a room containing multiple beds, as shown in FIG. 1H. The canopy frame 101 is therefore configured to facilitate storage and transportation of the pest control system 100, minimizing the time required for assembly and startup for pest control. In its folded state, the canopy frame 101 can be easily transported and stored in tight spaces, as shown in FIG. 1B. For example, canopy frame 101 features dimensions of 11 inches (L) x 6 inches (W) x 52 inches (H) when folded.

[0026] The canopy frame 101 may be configured to support one or more radio frequency (RF) shielding panels or curtains 109 (shown in FIG. 1C ) to isolate insect-infested items, objects, or areas during microwave irradiation treatment. The shielding panel or curtain 109 may include a single panel or curtain supported by the upper frame 103 and horizontal roof support members 104. The panel or curtain 109 may be configured as multiple curtains or sections. The curtain 109 may be configured to encase an area or item, such as a bed, shown in FIG. 1C , during treatment using microwave irradiation. Exemplary curtains 109 may include single-layer or multi-layer curtains, such as those sold by Akon Curtains (Fernandina Beach, Florida), and may be RoHS compliant. RoHS refers to Directive 2002 / 95 / EC (European Union standard) on the Restriction of Hazardous Substances, which relates to the restriction of the use of certain hazardous substances in electrical and electronic equipment.

[0027] In some implementations, the exemplary curtain 109 may be used to block microwave radiation at frequencies between approximately 400 MHz and approximately 18 GHz. The exemplary curtain 109 may include a nylon material coated with acrylic and plated or woven with one or more layers including silver, copper, or nickel. The exemplary curtain 109 may also include an electrostatic discharge protection layer to reduce the buildup of static electricity that could damage electronic devices. The exemplary curtain 109 may also attenuate sound or noise by approximately 80 dB to approximately 85 dB between approximately 30 MHz and 11 GHz. The exemplary curtain 109 may also be flame-retardant and comply with NFPA 701 standards. The exemplary curtain 109 may include multiple grommets (not shown) for removably attaching to the roof support member 104 of the canopy frame 101 using appropriate hooks. The canopy frame 101 may be configured with a curtain track with glide roller hooks for wrapping the curtain 109 around an item or area to be treated, such as a mattress 108 or bed 107. The curtain 109 may be removably attached to the roof support member 104 using magnets or hook-and-loop fasteners such as Velcro™. The curtain 109 may also be rolled up (109') to facilitate moving the canopy frame 101 after insect control is complete, as shown in FIG. 1D.

[0028] The exemplary insect control system may include a secondary shielding curtain or panel 110 (shown in FIG. 1E ) positioned outside the RF shielding curtain or panel 109. The exemplary outer shielding panel 110 may be made of a material having similar properties as the panel 109 and configured to be removably connected to the upper frame 103. The outer shielding panel 110 may be configured as multiple shielding panels, each positioned to be supported by adjacent legs 102 and the upper frame 103. For example, the multiple shielding panels 110 may be configured to be slidably and removably positioned in grooves or guide tracks extending along the length of each leg 102. When the exemplary insect control system 100 is assembled as described above, the system is configured to encase an object to be treated, such as a mattress 108, using one or more microwave shielding layers, thus isolating it from people and objects in the surrounding area. One or more exterior shield panels 110 protect people, equipment, and objects outside the assembled system 100 from stray or reflected microwave and other radiation.

[0029] In some implementations, the exemplary system 100 may include one or more top panels 111 positioned between two adjacent horizontally supporting roof members 104 and configured to be positioned above the object to be treated using shielding 109 (as seen in FIGS. 1C and 1F). The top panels 111 may also include one or more layers or coatings of microwave shielding material on the surface facing the object to be treated. The one or more top panels 111 and roof members 104 may be configured to removably support one or more microwave horn antennas 113 (as seen in FIG. 1G). This allows the horn antennas to be positioned above the object to be treated or the mattress. An exemplary horn antenna may include a 10 GHz to 15 GHz WR75 standard gain horn antenna (Pasternack, Irvine, California). The distance between the flared end of the horn antenna (the microwave radiation exit end located opposite the waveguide) and the surface of the mattress is approximately 2 feet. Each horn antenna 113 may be configured as a pyramidal horn antenna. Each horn antenna 113 may include other types of horn antennas, including, but not limited to, conical horns and corrugated horns. Each horn antenna 113 may be configured to direct microwave radiation 115 from a waveguide 112 connected to a microwave generator toward an object to be treated within the canopy frame 101 (see FIG. 1G). In an exemplary aspect, each horn antenna 113 is connected to the roof member support 104 using a suitable swivel connector, coupling, or joint and configured to be movable in one or more directions (X, Y, Z) to sweep the microwave radiation over the object to be treated. The microwave generator may be disposed within a cart 114 (FIG. 1F). The cart 114 may also include a battery power system using one or more rechargeable batteries, a battery management system, and a battery charge management system. The cart 114 may be movably positioned near and outside the canopy frame 101 during treatment of the object.

[0030] 2A-2C show schematic diagrams of an exemplary cart 114 associated with a system for decontaminating insect-infested objects, according to some implementations. The exemplary cart 114 (as seen in FIGS. 2A-2C) can include multiple interior compartments 216 and 217 accessible using removable panels or doors. Compartment 206 can be configured as a storage compartment for storing one or more of the shielding curtains 109, 110 and the horn antenna 113. Compartment 217 can be configured to house, but is not limited to, a microwave generator 221, a power module, and a rechargeable battery power system. The microwave generator can include components including, but not limited to, a magnetron, a power converter, a master microcontroller or control system, and microwave radiation transmission elements including coaxial cables (not shown for simplicity) configured to be coupled or removably connected to each waveguide 112. Microwave radiation from the coaxial cable is directed to radiate from the horn antenna 113 toward infected objects located within the canopy frame 101. Commercially available magnetrons, such as resonant cavity magnetrons rated at 500 W to 2 kW, can be used. The microwave radiation can be characterized by a frequency of about 5 GHz to about 20 GHz. The microwave radiation can be characterized by a frequency of about 10 GHz to about 20 GHz. The microwave radiation can be characterized by a frequency of about 12 GHz to about 15 GHz.

[0031] In some implementations, a master control system housed in compartment 217 implements the insect control protocol and controls the frequency of the microwave radiation, the frequency band of the microwave radiation, the power density (W / cm 2 or mW / cm 2The master control system may be configured to adjust parameters including one or more of: the number of times the pest infested object is exposed to microwave radiation; or the microwave radiation exposure time. The master control system may be configured to expose the pest-infested object to microwave radiation for a predetermined treatment (disinfection) period. The master control system may be configured to cycle microwave generation for decontamination during a second disinfection period and subsequent treatment periods. The master control system may be configured to control and implement any desired microwave treatment protocol. The example cart 114 may include a light indicator 222 that is easily visible to the operator and other personnel to indicate that the disinfection system is operating. The example cart 114 may include an electric on / off switch 223. The example cart 114 may feature dimensions of 21 inches (L) x 24 inches (W) x 50 inches (H). The example compartment 217 may feature dimensions of 21 inches (L) x 24 inches (W) x 26 inches (H).

[0032] 3A-3D show schematic diagrams of another exemplary insect control system 300 configured to treat objects within bunk beds and other confined spaces using microwave irradiation, according to some implementations. The exemplary system 300 includes an inflatable frame 302 configured and sized to fit within the space above each bunk 319 of a bunk bed 307 when inflated (see FIG. 3B). The frame 302 can be inflated after the frame 302 is placed within the bunk 319 of the bunk bed 307. An air pump can be located within a compartment 317 of the cart 314 to provide air for inflating the frame 302. The frame 302 can include a cross member 318 configured to support one or more waveguides 312 of one or more microwave horn antennas 313. When positioned within the frame 302, the one or more horn antennas are positioned above the surface of the mattress of the bunk bed 319 (see FIG. 3B). A microwave shield 310 (see FIG. 3C) can then be configured to encase the inflated frame 302, which is placed on a bunk bed 319 (FIG. 3D).

[0033] Alternatively, in some implementations, microwave shielding curtains 109, 110 may be used to isolate the bunk beds to be treated. One or more horn antennas 313 may be configured to direct microwaves toward the mattresses of the bunk beds 319, thereby allowing the entire surface of the bed to be treated with microwave radiation 315 for a predetermined time or according to a predetermined treatment protocol. A microwave generator may be located in a compartment 317 of the cart 314. Microwave radiation from the microwave generator may be transmitted to one or more waveguides 312 using a coaxial cable through openings 320 in the shield 310. Each horn antenna 313 may be configured to move in one or more directions to sweep the infested objects (e.g., bunk bed mattresses) with microwave radiation. The compartment 317 may be configured to house, but is not limited to, a microwave generator, a power module, and a rechargeable battery bank. The microwave generator may include components such as, but are not limited to, a magnetron, a power converter, a master microcontroller or control system, and a microwave radiation transmission element including a coaxial cable (not shown) that directs microwave radiation from the coaxial cable and radiates it from the horn antenna 313 within the shield 310 towards the object that needs to be treated and located.

[0034] In another exemplary aspect of the insect control system 100, the cart 114 may be configured to be remotely operated by a human operator using application software or “app” installed on a smart device, for example. The “app” may also be configured to operate the insect control system by executing a predetermined insect control protocol, which may include determining microwave radiation frequency, microwave radiation exposure time, or treatment effectiveness. In another exemplary aspect of the system 100, the cart 114 may be configured to move substantially autonomously as a robotic cart. That is, the cart 114 is capable of sensing its surrounding environment and moving with minimal human input. The motor and drive train of the robotic cart may be controlled using a master control system or may be controlled using a dedicated control system that may be configured to receive instructions from and communicate with the master control system. The robotic cart 114 may use multiple sensors, including radar, computer vision, GPS, ultrasonic proximity sensors, optical sensors, sonar, gyroscopes, etc., to sense its surroundings and navigate. The robotic locomotion subsystem may include an undercarriage, including wheels or casters. Other examples of cart 114 may include a graphical user interface for manually selecting or inputting treatment parameters (such as start, stop, and exposure times, wait times, treatment cycles until sufficient pest control effect is achieved, etc.).

[0035] FIG. 4 shows a schematic diagram of an exemplary insect control method 400 for selectively controlling insects using microwave radiation while minimizing impact on host media, such as bedding and furniture, according to some implementations. Target insects may include one or more of bed bugs, termites, bat flies, wasps, poultry flies, mites, or rice weevils. The exemplary operation 400 may begin at 431 by providing an RF shielding canopy suitable for encasing a contaminated object or surface. For example, the exemplary dual-layer shields 109 and 110 may be used to provide the canopy. Alternatively, the RF shielding may be provided by a prefabricated canopy 310 sized appropriately for treating bunk beds or contaminated objects. At 432, the exemplary operation 400 may include providing a mobile cart including a microwave generator and components for transmitting microwave radiation from the microwave generator and directing the microwave radiation toward the infested surface.

[0036] An exemplary mobile cart may include the cart 114 described above, which may be configured to be positioned near the RF shielding canopy at 432 during insect control. The insect-infested surface or object may then be exposed to microwave radiation at a predetermined frequency for a predetermined exposure time at 433. Depending on the type of insect requiring control, the frequency of the incident radiation may be selected to be between about 2 GHz and about 20 GHz. In some implementations, the frequency of the incident microwave radiation may be between about 5 GHz and about 15 GHz. In other implementations, the frequency of the incident microwave radiation may be between about 10 GHz and about 15 GHz. In some implementations, the frequency of the incident microwave radiation for insect control may be about 12.5 GHz. The object to be treated may be exposed to microwave radiation for a treatment time of about 5 seconds to about 60 seconds. The microwave irradiation treatment time may be between about 5 seconds and about 30 seconds.

[0037] Alternatively, the treated object may be exposed to pulsed microwave radiation. The pest control surface may then be inspected in step 434 to determine whether pest control was effective. An example of a microwave pest control method disclosed herein may be considered effective if at least 99% (a threshold level) of all life stages of the target insects, including eggs, are destroyed or killed. The step of inspecting the pest control surface after microwave irradiation may include visual inspection. Alternatively, a thermal imaging camera configured to detect insects may be used. An example of a suitable thermal imaging camera may be the Exx series camera sold by Teledyne FLIR (Wilsonville, Oregon). The inspection step may be performed substantially continuously or at predetermined intervals during the pest control process. If the inspection step 434 reveals insufficient pest control, the microwave pest control process may be repeated in step 435. Repeating the process may include increasing one or more of the incident microwave radiation frequency or exposure time.

[0038] This exemplary insect control method may include a hold time between repetitions of the control protocol. The exemplary insect control treatment method 400 may further include adjusting the incident microwave radiation frequency, pulse width, and pulse interval (if microwave pulses are used) to account for the dielectric properties and bulk conductivity of the target insect. The selected incident microwave radiation frequency may be within ±250 MHz of the target insect's resonant frequency. Target insects may have multiple resonant frequencies depending on their internal water content and whether they have recently fed. The frequency of the microwave radiation is then selected to cover the resonant frequency range of the target insect. When the target insect is exposed to microwave radiation at frequencies ±250 MHz of the insect's resonant frequency, the insect may vibrate at the resonant frequency and with a higher amplitude than other frequencies. The temperature inside the insect increases rapidly (flash heating), but remains localized within the insect's carapace. Therefore, the insect is killed while minimizing temperature rise in the surrounding medium. Each insect may have a unique resonant frequency.

[0039] External materials or media that may be infested by insects, including beds, books, sofas, walls, etc., are not damaged by exposure to microwave radiation using the disclosed exemplary methods. Examples of insect infestations may also include one or more of mattresses, travel furniture, wall voids, and carpets. During exposure to the microwave radiation disclosed above at frequencies ±250 MHz of the insect's resonant frequency, the temperature of these objects does not rise significantly above ambient temperature for a short period of time. For example, the temperature rise of the media during exposure to microwave radiation may be less than about 10% above ambient temperature.

[0040] Without wishing to be bound by any particular theory, insects are believed to be dielectrics with low electrical conductivity, possessing a dielectric constant ε' and a dielectric loss factor ε". In the exemplary manner described above, the difference in the dielectric properties of the insect and the host medium may allow the insect to selectively respond as an oscillator to incident microwave radiation without adversely affecting the host medium. In microwave applications, the power dissipated per unit volume, P, is absorbed by a material (e.g., an insect) from an AC electric field as follows:

number

[0041] Without being bound by any particular theory, the dielectric function ε(f) of a material (ε is the dielectric constant of the material and f is the frequency of the radiation) is generally related to the incident radiation frequency, the resonant frequency of the material, and, if applicable, the plasma frequency through a dispersion model. In a wide spectral range (low frequencies and above), where multiple energy transition levels may exist, the dielectric function may contain different transitions, each characterized by a resonant frequency. A characteristic property of a vibrating system is the phenomenon of resonance at a specific frequency. Once the resonant frequency of a material, such as an insect of interest, is known or calculated using an appropriate method, applying an external force (e.g., microwave radiation) at the same resonant frequency will cause the material to vibrate with a higher amplitude compared to applying microwave radiation at other frequencies.

[0042] Figures 5A-5C show the A / m 2 Figure 5 shows the results of a finite element analysis of power deposition, as revealed by the distribution of complex volume current in units of (Jvol). As shown in Figures 5B-C, exposure to microwaves at 5.8 GHz and 9.2 GHz results in a localized and uneven distribution of volume current, forming hotspot regions within the body of a bed bug, although some regions remain unaffected by the incident microwaves. These hotspot regions are thought to arise from localized vibrations of molecules within the region due to exposure to the incident microwaves. However, as shown in Figure 5A, at a frequency of 12.4 GHz, the incident microwaves are distributed throughout the insect's body without producing localized concentrations or hotspots. In other words, the insect's body appears to be vibrating at its resonant frequency. Similar simulation studies using termites with nominal dimensions of 10 mm (length) x 4 mm (width) x 2.5 mm (height) suggest that microwave irradiation at frequencies between approximately 13 GHz and approximately 15 GHz may be necessary for termite control. The publication by Thielens (2018) entitled "Exposure of Insects to Radiofrequency Electromagnetic Fields Between 2 and 120 GHz" is incorporated herein by reference in its entirety.

[0043] As discussed in the example below, exposure to 12.4 GHz radiation kills all stages of bed bug development, even for microwave exposure times as short as 15 seconds, which correlates well with simulation results. As previously mentioned, the resonant frequency is generally a function of the dielectric and conductive properties of insects such as bed bugs.

[0044] [example] In the following examples, the effectiveness of microwave radiation in controlling bed bugs was tested using 300W microwave generators (Instruments for Industry IFI-T82-300 2-8 GHz 300W and IFI T188-300 8-18 GHz 300W) capable of generating microwaves in the 2-8 GHz and 8-18 GHz ranges. Samples containing six bed bugs of each of the five bed bug life stages (adult female, adult male, small nymph, medium nymph, and large nymph) were placed in containers and vials designed to match the output aperture of the appropriate waveguide. Based on the modeling results described above, microwave radiation at 5.8 GHz, 9.2 GHz, and 12.4 GHz was selected for testing. Bed bugs were allowed to feed within 72 hours of treatment. Table 1 shows the size of bed bugs at various life stages. [Table 1]

[0045] A signal generator was used to control the output of the system. A frequency-specific waveguide was used, and the bed bugs were placed at or near the opening of the waveguide. Example 1. Exposing various life stages of bed bugs to 200W, 5.8GHz microwaves for 30 seconds Thirty seconds of 5.8 GHz radiation killed all female bed bugs and some male bed bugs. The radiation treatment had no effect on nymphs, and the dead bed bugs showed no visible morphological changes. Example 2. Exposing various life stages of bed bugs to 150W, 9.2GHz microwaves for 60 seconds Irradiation with 9.2 GHz radiation for 60 seconds resulted in the death of all male, female, and large larvae. Approximately 80% of medium-sized larvae died. The radiation treatment had no effect on small larvae. No visible morphological changes were observed in the dead insects. Example 3. Various life stages of bed bugs exposed to 200W, 12.4GHz microwaves for 15 and 30 seconds. Exposure to 12.4 GHz radiation for 15 and 30 seconds (hereinafter referred to as treatment times) killed all life stages of bed bugs. After treatment, the bed bugs were scattered throughout the vial. After treatment, the bed bugs appeared larger and lighter in color, as if "inflated" or inflated like a balloon.

[0046] The exemplary systems and methods described herein are not necessarily limited to application to the extermination or control of bed bugs. They may also be used to exterminate or control other insects, including any one or more of bat flies, wasps, poultry pests, mites, termites, or rice weevils. Thus, the scope of the present invention is not limited to the extermination and eradication of bed bugs.

[0047] The Abstract is provided to comply with 37 C.FR § 1.72(b) to allow the reader to quickly determine the nature and gist of the technical disclosure at a glance. The Abstract should not be used to interpret or limit the scope or meaning of the claims.

[0048] While the present disclosure has been described in connection with preferred embodiments for practicing the same, those skilled in the art will recognize that many modifications may be made without departing from the spirit of the disclosure, and therefore, the scope of the present disclosure is not to be limited in any way by the foregoing description.

[0049] It should also be understood that various modifications may be made without departing from the essence of the present disclosure. Such modifications are implicitly included herein and remain within the scope of the present disclosure. It should be understood that the present disclosure is intended to produce patents covering many aspects of the present disclosure, both individually and as a system as a whole, and in both method and apparatus modes.

[0050] Furthermore, various elements of the disclosure and claims may each be embodied in a variety of ways, and the disclosure should be understood to encompass all such variations, i.e., variations in the implementation of the device, method, or process, or merely variations of any of these elements.

[0051] Specifically, it should be understood that the terms describing each element may be expressed in equivalent apparatus or method terms, even if only the function or result is the same. Such equivalent, broader, or more general terms should be considered included in the description of each element or operation. Such terms may be substituted as necessary to clarify the broad scope implicit in this disclosure. It should be understood that all operations may be expressed as a means for performing that operation or as an element that causes the operation. Similarly, each physical element disclosed should be understood to include a disclosure of the operation that the physical element facilitates.

[0052] Furthermore, for each term used, unless its usage in this application is inconsistent with such interpretation, the common dictionary definition contained, for example, in at least one standard technical dictionary recognized by artisans and the most recent edition of Random House Webster's Unabridged Dictionary, should be understood to be incorporated herein for each term and all definitions, alternative terms, and synonyms.

[0053] Additionally, the use of the transitional phrase "comprising" is used to maintain the "open-ended" claims herein in accordance with conventional claim interpretation. Thus, unless the context requires otherwise, "comprising" is intended to mean the inclusion of a recited element or step or group of elements or steps, but not the exclusion of other elements or steps or group of elements or steps. Such terms should be interpreted in the broadest manner to afford applicant the broadest scope legally permissible. [References] 1. WS Cranshaw, M. Camper, F. Pearis "Bat Bugs, Bed Bugs and Relatives," Fact Sheet No. 5.574, Colorado State University, December 2013. 2. DM Miller, A. Polanco, "Bed Bug Biology and Behavior," Virginia Polytechnic Institute and State University, August 2010. 3. SO Nelson, "Radio-Frequency and Microwave Dielectric Properties of Insects," J. Microwave Power and Electromagnetic Energy, 36 (1), 2001. 4. J. Ondracek, and V. Brunnhofer, "Dielectric Properties of Insect Tissues," Gen. Physiol. Biophys., 3, 251-57, 1984. 5. A. Thielens, D. Bell, D.B. Mortimore, M.K. Greco, L. Martens and W. Joseph, "Exposure of Insects to Radio-Frequency Electromagnetic Fields from 2 to 120 GHz," Scientific Reports (Nature), 2018) 8:3924. 6. A. Tyrpak, "How to Kill Bed Bugs in Portable Items: Unconventional Non-chemical Approaches," Senior Research Thesis, The Ohio State University, May 2016.

Claims

1. In insect control systems, a collapsible canopy frame configured to be positioned over an insect-infested object; one or more RF shielding curtains supported by the canopy frame and configured to encase the insect-infested object; one or more microwave horn antennas supported by a plurality of roof support members on a surface of the canopy frame, the one or more microwave horn antennas being positioned a predetermined distance above the insect infested object; a portable cart movably positioned outside the RF shielding envelope and including a microwave generator; activating the microwave generator to generate microwave radiation at a frequency within ±250 MHz of the insect's resonant frequency; transmitting microwave radiation from said microwave generator to said one or more horn antennas; or directing said microwave radiation towards said insect-infested object; and a control system configured to perform one or more of the operations of:

2. 2. The insect control system of claim 1, wherein the one or more RF shielding curtains include a first curtain configured to encase the insect-infested object and a second curtain positioned outside the first curtain.

3. 2. The insect control system of claim 1, wherein said one or more horn antennas each include a flared end, and wherein the predetermined distance between said insect-infested object and the flared end of each of said horn antennas is approximately 2 feet.

4. 10. The insect control system of claim 1, wherein said one or more horn antennas comprise a pyramidal horn antenna.

5. 10. The insect control system of claim 1, wherein the one or more horn antennas are configured to be connected to one or more swivel couplings supported by the plurality of roof support members.

6. 2. The insect control system of claim 1, wherein the portable cart includes a plurality of internal compartments, at least one of the internal compartments configured to house one or more of the one or more horn antennas or the one or more RF shielding curtains.

7. 10. The insect control system of claim 1, wherein the control system is further configured to communicate with application software associated with a smart device to remotely operate the insect control system or move a portable cart.

8. 10. The insect control system of claim 1, wherein the portable cart includes a rechargeable battery power system.

9. 1. A method for selectively controlling insects in an infested object using microwave radiation, comprising: The above method is providing a decontamination system for encasing an insect-infested object, the decontamination system comprising: one or more RF shielding curtains configured to encase the insect-infested object, the one or more RF shielding curtains being supportable by a foldable canopy frame; a portable cart movably disposed outside the RF shielding curtain and including a microwave generator; providing a decontamination system configured to transmit microwave radiation from the microwave generator toward the insect-infested object; selecting a first incident microwave radiation frequency that is within ±250 MHz of a resonant frequency of the insect; exposing the insect-infested object to microwave radiation for a first predetermined treatment time.

10. 10. The method of claim 9, wherein the first incident microwave radiation frequency is between about 10 GHz and about 15 GHz.

11. 10. The method of claim 9, wherein the resonant frequency of the insect is about 12.5 GHz.

12. 10. The method of claim 9, wherein the first predetermined processing time is between about 5 seconds and 30 seconds.

13. 10. The method of claim 9, further comprising inspecting the infested object after the first predetermined treatment time and repeating the decontamination procedure if insect eradication is less than about 99%.

14. 14. The method of claim 13, wherein the repeating step includes exposing the insect-infested object to microwave radiation at a second radiation frequency higher than the first radiation frequency.

15. 14. The method of claim 13, wherein the repeating step includes exposing the insect-infested object to microwave radiation for a second predetermined treatment time that is longer than the first predetermined treatment time.

16. 14. The method of claim 13, wherein the inspecting operation includes inspecting the insect-infested object using one or more of a visual inspection or an inspection using a thermal imaging camera.

17. In insect control systems, a collapsible canopy frame configured to expand to form an expanded canopy frame over the insect-infested object; a prefabricated microwave shield (RF shield) configured to encase the inflated canopy frame; one or more microwave horn antennas supported by a plurality of roof support members on the canopy frame, the one or more microwave horn antennas positioned a predetermined distance above the insect infested object; a portable cart movably disposed outside the prefabricated microwave shield, the portable cart including an air pump for inflating the foldable canopy frame and a microwave generator; activating the microwave generator to generate microwave radiation at a frequency within ±250 MHz of the insect's resonant frequency; transmitting microwave radiation from said microwave generator to said one or more horn antennas; or directing said microwave radiation towards said insect-infested object; and a control system configured to perform one or more of the operations of:

18. 18. The insect control system of claim 17, wherein said microwave radiation is characterized by a frequency of about 10 GHz to about 15 GHz.

19. 18. The insect control system of claim 17, wherein said microwave radiation is characterized by a frequency of about 12.5 GHZ.

20. 18. The insect control system of claim 17, wherein the one or more horn antennas comprise a pyramidal horn antenna.

21. 20. The insect control system of claim 17, wherein the one or more horn antennas are configured to be connected to one or more swivel couplings supported by a plurality of roof support members.

Images