WO2013025894A2

WO2013025894A2 - Door handle sterilization system

Info

Publication number: WO2013025894A2
Application number: PCT/US2012/051120
Authority: WO
Inventors: Luis ROMO; Nick GARRITANO; Tagbo Niepa
Original assignee: Helios Innovative Technologies, Inc.
Priority date: 2011-08-16
Filing date: 2012-08-16
Publication date: 2013-02-21
Also published as: WO2013025894A3

Abstract

A device for sterilizing a structure includes a frame and a housing, which is mounted to the frame. The housing contains a UV radiation source. The frame is adapted to retain the housing in a plurality of positions, wherein, in a first of the plurality of positions, the housing is positioned wherein the UV radiation source illuminates and sterilizes at least a portion of the structure, and wherein, in a second of the plurality of positions, the housing is positioned to permit access to the structure.

Description

DOOR HANDLE STERILIZATION SYSTEM

BACKGROUND OF THE INVENTION

Cross-Reference to Related Application

[0001] This application claims priority of US provisional application 61/524,103, filed August 16, 2011, the entire disclosure of which is hereby incorporated herein by reference.

Technical Field

[0002] The present invention generally relates to devices and methods for sterilizing structures, such as door handles, by exposing a structure to UV radiation. More particularly, the present invention relates to a device and method for conveniently sterilizing structures without exposing users to UV radiation.

Background Information

[0003] Many communicable diseases are transmitted by physical contact between persons, or between a person and surface with which an infected person previously has come in contact. The types and seriousness of communicable diseases transmitted in this manner are varied. Viral and bacterial diseases alike can be communicated by physical contact with surfaces upon which the infectious agents reside. Further, there is an increasing awareness and concern worldwide of the possibility of widespread outbreaks, or even pandemics, of communicable disease; these concerns stem in part from possible spontaneous mutations of influenza and other viruses, as well as the increasing resistance of bacterial strains to conventional and even newly developed and powerful antibiotics.

[0004] Thus, a need exists for improved devices and methods for combating the spread of diseases that may be communicated via physical contact with infected surfaces.

SUMMARY OF THE INVENTION

[0005] Briefly, the present invention satisfies the need for improved means for combating the spread of diseases that may be communicated via physical contact with infected surfaces. [0006] The present invention provides, in a first aspect, a device for sterilizing a structure, for example, a door handle. The device includes a frame and a housing, which is mounted to the frame, and which contains an ultraviolet (UV) radiation source. The housing moves along the frame in a plurality of positions. In a first of the plurality of positions, the housing is positioned such that the UV radiation source illuminates and sterilizes at least a portion of the structure. In a second of the plurality of positions, the housing is positioned to permit access to the structure.

[0007] The present invention provides, in a second aspect, a method of sterilizing a structure. The method utilizes a device for sterilizing a structure, which includes a frame and a housing, which is mounted to the frame, and which contains a UV radiation source. The housing moves along the frame in a plurality of positions. In a first of the plurality of positions, the housing is positioned such that the UV radiation source illuminates and sterilizes at least a portion of the structure. In a second of the plurality of positions, the housing is positioned to permit access to the structure. The method comprises mounting the device over a structure, and illuminating and sterilizing at least a portion of the structure with the UV radiation source provided in the device.

[0008] The present invention provides, in a third aspect, a method of sterilizing a structure, which comprising mounting a frame having a movable housing in a first position substantially concealing the structure, the housing having a UV radiation source; illuminating and sterilizing at least a portion of the structure with the UV radiation source; detecting movement in a vicinity of the housing; and, when movement is detected, moving the movable housing along the frame from the first position to a second position, different from the first position, to at least partially expose the structure.

[0009] These and other objects, features and advantages of this invention will become apparent from the following detailed description of the various aspects of the invention taken in conjunction with the appended claims and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 is a front perspective view of a device for sterilizing a structure according to one aspect of the invention showing a housing in a first position. [0011] FIG. 2 is a side perspective view of the device shown in FIG. 1 showing the housing in a second position.

[0012] FIG. 3 is a side perspective view, similar to FIG 2, of the device shown in FIG. 1 showing the housing in a first position.

[0013] FIG. 4 is an end elevation view of the device shown in FIG. 1. [0014] FIG. 5 is a top plan view of the device shown in FIG. 1. [0015] FIG. 6 is a rear plan view of the device shown in FIG. 1.

[0016] FIG. 7 depicts an embodiment of a device according to the present invention, installed over a structure.

[0017] FIG. 8 depicts a front perspective of an embodiment of the present invention.

[0018] FIG. 9 depicts a view of a housing according to one aspect of the present invention.

[0019] FIGS. 10a and 10b show front perspective views of a device according to one aspect of the invention in situ when the housing is in a first position (10a) and a second position (10b).

[0020] FIG. 11 is a front perspective view of a device according to an aspect of the invention.

[0021] FIG. 12 shows the results of UVC treatment of Bacillus cereus using an embodiment of the invention.

[0022] FIG. 13 shows the results of UVC treatment of Candida albicans using an embodiment of the invention.

[0023] FIG. 14 shows the results of UVC treatment of Klebsiella pneumoniae using an embodiment of the invention.

[0024] FIG. 15 shows the results of UVC treatment of Pseudomonas aeruginosa using an embodiment of the invention.

[0025] FIG. 16 shows the results of UVC treatment of Staphylococcus aureus using an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0026] The present invention is generally directed to methods and devices for sterilizing a structure, wherein the device includes a frame and a housing, which is mounted to the frame, and which contains a UV radiation source. The housing moves along the frame in a plurality of positions. In a first of the plurality of positions, the housing is positioned such that the UV radiation source illuminates and sterilizes at least a portion of the structure. In a second of the plurality of positions, the housing is positioned to permit access to the structure.

[0027] FIG. 1 illustrates one embodiment of a device 10 for sterilizing a structure (not shown). The device 10 typically includes a frame 20 and a housing 24 mounted to the frame 20. The housing 24 typically contains a UV radiation source 26, for example, one or more UV lamps. According to aspects of the invention, frame 20 may be adapted to retain the housing 24 in a plurality of positions, for example, two or more positions. Typically, in a first of the plurality of positions 25 (as shown in FIG. 2), the housing 24 is positioned wherein the UV radiation source 26 illuminates and sterilizes at least a portion of the structure (not shown), and wherein, in a second of the plurality of positions 27 (as shown in FIG. 3), the housing 24 is positioned to permit access to the structure.

[0028] The device 10 comprises a frame 20 which includes elongated projections 21 having tracks 22, for example, upon which housing 24 may translate. The frame 20 and elongated projections 21 are also illustrated in FIG. 6, which is a rear view of the device 10 of FIG. 1. Returning to FIG. 1, in the device 10, a housing 24 is mounted to the frame 20, which is adapted to retain the housing 24 in a plurality of positions. In some embodiments, the housing 24 is constructed to reduce and/or prevent UV radiation from penetrating the housing. The housing 24 is designed to minimize and/or prevent a user's exposure to the UV radiation, which is significant for user safety. For example, in certain embodiments, the housing 24 may be at least partially constructed of a transparent material 24b that blocks UV radiation from escaping the chamber, as illustrated in FIG. 11. In certain embodiments, the housing 24 comprises a layer, for example, a polymer layer, which blocks UV radiation. The housing 24 also contains a UV radiation source 26.

[0029] The UV radiation source 26 may be one or more suitable sources that emit UV radiation, for example, electromagnetic radiation having a wavelength of between about 100 and about 400 nm. In some embodiments, the UV radiation source 26 is one or more ultraviolet lamps, for example, a model 3 watt 10.5 volt T6 Intermediate Screw (El 7) Base Germicidal Preheat Incandescent lamp (EIKO), or its equivalent. In some embodiments, the UV radiation source 26 is one or more of a traditional UV lamp, such as a mercury-based UV lamp. In some embodiments, the UV radiation source 26 is one or more UV light emitting diode (LED) lamps.

[0030] Devices and methods of the present invention sterilize structures (for example, kill at least 85%, or at least 88% or at least 90% or at least 91%, or at least 92% or at least 93% or at least 94% or at least 95% or at least 96% or at least 97% or at least 98% or at least 99% or at least 99.2%) or at least 99.5% or at least 99.9% of pathogens, such as viruses and/or bacteria and/or other pathogens on a structure) by irradiating the structures with UV radiation. In some embodiments, the present invention provides for three-dimensional UV irradiation of a structure, that is, irradiation from 2 or more directions, for instance, 2 or more orthogonal directions.

[0031] In certain embodiments, the present invention relates to a method of sterilizing a structure by mounting the device 10 over the structure and illuminating and sterilizing at least a portion of the structure with the UV radiation source 26 provided in the device. In certain methods of the present invention, the housing 24 moves on the frame 20 to a first position 25 where the housing 24 substantially conceals the structure. In this position 25, the UV radiation source 26 illuminates and sterilizes at least a portion of the structure with the UV radiation source.

[0032] In some embodiments, the UV radiation source 26 emits shortwave UV radiation. In certain embodiments, the UV radiation source 26 emits radiation having a wavelength of between about 100 nm and about 315 nm. In certain embodiments, the UV radiation source 26 emits UV-C radiation having a wavelength of between about 100 nm and 280 nm. In certain embodiments, the UV radiation source 26 emits UV-C radiation having a wavelength of between about 180 nm and about 280 nm, which is lethal to microorganisms. In particular, radiation of these wavelengths is known to be germicidal, that is, it deactivates the DNA of bacteria, viruses and other pathogens and thus destroys their ability to multiply and cause disease. Germicidal UV effectively kills up to 99.9% of all viruses, bacteria and mold. In certain embodiments, the UV radiation source 26 emits radiation having a wavelength of between about 240 nm and about 280 nm. In certain embodiments, the UV radiation source 26 emits radiation having a wavelength of between about 250 nm and 260 nm. In certain embodiments, the UV radiation source 26 emits radiation having a wavelength of between about 253 nm and about 254 nm.

[0033] The following is a partial list of pathogens killed by embodiments of the present invention emitting germicidal UV radiation having a wavelength between about 180 nm and about 280 nm, and some of the diseases they cause: Bacteriophage (E. Coli), HIV, Infectious Hepatitis, Influenza (Flu), Poliovirus-Poliomyelitis, Tobacco mosaic, Rotavirus, S Bacillus anthracis (Anthrax), Bacillus magaterium sp. (Spores), Bacillus magaterium sp. (Veg), Bacillus paratyphusus, Bacillus subtilus spores, Bacillus subtilis, Clostridium tetani (Tetanus/ Lockjaw), Corynebacterium diphtheriae (Diphtheria), Eberthella typosa, Escherichia Coli (E.Coli), Leptospira Canicoal-infections (Jaundice), Methicillin-resistant Staphylococcus Aureus (MRSA) Micrococcus candidus, Micrococcus spheroids, Mycobacterium tuberculosis (Tuberculosis), Neisseria catarrhalis, Phtomomnas aeruginosa, Pseudomonas fluorescens, Salmonella enteritidis, Salmonella paratyphi (Enteic Fever), Salmonella typhosa (Typhoid Fever), Salmonella typhimurium, Sarcina lutea, Serratia marcescens, Shigella dysenteriae (Dysentery), Shigella flexneri - (Dysentery), Shigella paradysenteriae, Spirillum rubrum, Staphylococcus Albus (Staph), Staphylococcus Aureus (Staph), Streptococcus hemolyticus, Streptococcus lactis, Streptococcus viridians, Vibrio comma - (Cholera), and mold spores including Aspergillius Flavis, Aspergillius glaucus, Aspergillius niger , Mucor racemosus A, Mucor racemosus B, Oospora lactis, Penicillium expansum, Penicillium roqueforti, Penicillium digitatum, and Rhisophus nigricans. The effectiveness of aspects of this invention to kill other pathogens will be apparent to those of skill in the art.

[0034] In certain embodiments, the UV radiation source 26 is able to produce different patterns of light. The patterns may be, for instance, pulsed, fractional, collimated or scattered to ensure sufficient propagation of the UV light.

[0035] In certain embodiments, the housing 24 is movably mounted to the frame 20. In certain embodiments, the frame 20 is adapted to retain the housing 24 in a plurality of positions. In the illustrated embodiment, the housing 24 is slidably mounted to the frame 20, such that the housing can move in a direction parallel to projections 21, for example, on tracks 22. In some embodiments, the tracks 22 are oriented such that the housing 24 can move in a lateral motion, as shown in FIG. 1.

[0036] FIG. 2 illustrates the device 10 of FIG. 1 in a first position 25 of a plurality of positions, wherein the housing 24 is positioned to allow the UV radiation source 26 to illuminate and sterilize at least a portion of a structure (not pictured). FIG. 3 illustrates the device 10 of FIG. 1 in a second 27 of a plurality of positions, wherein the housing 24 is positioned to permit user access to a structure (not shown), for example, access by hand.

[0037] Returning to FIG. 1, the device 10 may further comprise a motion detector 28, for example, mounted to frame 20, though detector 28 may be mounted anywhere on device 10. In one aspect, detector 28 may be mounted remotely from device 10, and, for example, may communicate with device 10 by wire or wirelessly. In certain embodiments, a device 10 may comprise one or more motion detectors 28. In certain embodiments, the motion detector 28 is programmable. In some embodiments, the motion detector 28 is configured to detect movement within a predetermined distance from the device 10. The predetermined distance may be any distance suitable to the environment in which the device is operating, and the device is programmable to select a desired detection distance. In certain embodiments, the predetermined distance comprises a detection radius of between about 6 inches and 15 feet, or between about 6 inches and 10 feet, or between about 12 inches and 10 feet, or between about 3 feet and 12 feet, or between about 4 feet and 11 feet, or between about 6 feet and about 10 feet, or between about 4 feet and 8 feet. In one aspect, motion detector 28 may be a sonic detector, for example, an ultrasonic detector; a laser detector; a thermal detector, for example, an infrared detector; or a piezoelectric detector, among other types motion detectors. In certain embodiments, the motion detector 28 is located on or within the housing 24, as shown in FIG. 1. In other embodiments, the motion detector 28 is not located on or within the housing 24, as shown in FIG. 10.

[0038] The device 10 is configured such that when the motion detector 28 detects motion within the predetermined distance, the housing 24 remains in, or slides along the frame 20 to arrive at the second position 27, wherein the housing is situated to permit access to a structure. In one aspect of the invention position 27 may reside anywhere along projections 21, for example, where the structure is exposed and becomes accessible, for example, to a consumer. However, in one aspect position 27 may be located at the distal end 23 of projections 21. In some embodiments, the housing 24 slides over the structure to be sterilized when the structure is not in use, and/or when the motion detector 28 does not detect any motion. The device 10 can be programmed to achieve any desired positioning of housing 24. For example, in some

embodiments, the device 10 is programmed such that, absent detection of motion, the default position of housing 24 is in the first position 25, wherein the housing 24 is positioned to allow the UV radiation source 26 to sterilize the structure. In other embodiments, the device 10 is programmed such that, absent detection of motion, the default position of housing 24 is a second position 27, wherein the housing 24 is positioned to allow access to the structure.

[0039] In some embodiments, the device 10 is programmed to continuously emit UV radiation and sterilize the structure when it is in the first position 25, that is, the UV radiation is emitted at all times when the device 10 is not in use by a user; this could be useful in, for instance, a hospital setting. In some embodiments, the device 10 is programmed to emit UV radiation only during specific time intervals; for instance, the device may be programmed to emit UV radiation from 7:00 a.m. until 7:00 p.m. in an office building whose employees are present only from 9:00 a.m. until 5:00 p.m. In other embodiments, the device 10 is programmed to emit UV radiation for intervals of predetermined lengths (such as five minutes, or four minutes, or three minutes, or two minutes, or one minute, or for any other desirable duration) to sterilize or maintain the sterility of a structure when it is not in use. In some embodiments, the device 10 may be configured such that the UV radiation source 26 emits radiation for intervals of predetermined lengths one or more times per every set longer period of time (for example, the radiation source 26 may emit radiation for four-minute intervals once every hour or two). In some embodiments, the device 10 can be programmed to emit UV radiation in those instances in which the device 10 has not been activated by a user for a predetermined period of time. These examples are not intended to be exhaustive, and persons having ordinary skill in the art will readily understand that the device 10 and/or the motion detector 28 may be programmed in any way to best suit the needs of the environment in which the device 10 is being operated.

[0040] The device 10 is configured to receive power from a source of electrical current which functions as the power source for the functional elements of the device. In certain embodiments, the power source is a source of conventional alternating current or direct current (e.g., batteries) (not shown in the figures). In some embodiments, a circuit from the device 10, connected to a facility's electrical system or the local electrical grid, may be provided using wiring, switching, and/or possibly transformers according to generally known practices, as illustrated in FIG. 10a and FIG. 11 (40). Some of these pertinent electrical components may be contained within the device 10 itself, for example, within frame 20 or within housing 24. For example, in certain embodiments, the power source is a battery contained in the device 10 itself.

[0041] In the illustrated embodiment of FIG. 1, the housing 24 may further comprises a cap plate 29 and 30, which reduces and/or prevents UV radiation leakage. FIG. 4 illustrates a bottom- view of the device 10 from FIG. 1, wherein the cap plate 30 is visible.

[0042] FIG. 5 illustrates a front- view of the device 10 of FIG. 1. In this illustrated embodiment, the housing 24 of device 10 is positioned to permit access to a structure. The UV radiation source 26 does not emit radiation in this position.

[0043] FIG. 7 is another embodiment of a device 200 according to the present invention. In this embodiment device 200 includes a housing 224 and a frame 220 having elongated projections 221 having tracks 222. Similar to device 10, the frame 220 is adapted to retain the housing 224 in a plurality of positions. The housing 224 comprises a UV radiation source 226 and one or more motion detectors 228. In some embodiments, in a first 225 of the plurality of positions, the housing 224 is positioned wherein the UV radiation source 226 illuminates and sterilizes at least a portion of a structure 232, for example, a handle or knob, and wherein, in a second 227 of the plurality of positions, the housing 224 is positioned to permit access to the structure 232.

[0044] In the illustrated embodiment, the structure 232 is a door handle. However, as used herein, the term "structure" is intended to cover any object suitable for sterilization by the presently disclosed device and method. In some aspects of the present invention, the term "structure" refers to objects which are commonly gripped or contacted by human hands, and/or objects which facilitate the spread of communicable diseases by person-to-object contact. Common examples of structures include handles (e.g., door handles, cabinet handles, drawer handles, refrigerator handles), medical tools and supplies, toilet seats, buttons, knobs, and light switches. In certain aspects of the present invention, the structure is stationary (i.e., does not move) while it is being sterilized.

[0045] FIG. 8 depicts another embodiment of a device 300 according to the present invention. In this embodiment device 300 includes a frame having tracks (not shown) beneath the frame 320 and a housing 324. Similar to device 10, the frame 320 is adapted to retain housing 324 in a plurality of positions. The housing 324 comprises a UV radiation source (not shown) and one or more motion detectors 328. In the illustrated embodiment, the housing 324 is shown in a second position 327 wherein the housing 324 is positioned to permit access to a structure (not shown), for example, a handle or knob. In the illustrated embodiment of FIG. 8, the housing 324 may further comprise cap plates 329 and 330, which reduce and/or prevent UV radiation leakage by at least 94%, or at least 96%, or at least 98%>, or at least 99%. In some embodiments, cap plate 329 completely seals off the housing 324. In some embodiments, cap plate 330 has an opening for passage of a structure being sterilized. In certain embodiments, cap plate 330 has an opening for passage of structure, and the opening is covered by a material which reduces and/or prevents UV radiation leakage, but allows the housing 324 to pass over a structure.

[0046] FIG. 9 depicts a view of a housing 324 according to one aspect of the present invention. The housing 324 includes depressions 326 configured to support one or more UV radiation sources (not shown), for example, lamps. The housing 324 also includes cap plates 329 and 330.

[0047] In some embodiments, the device can come incorporated completely within the thickness of a door. In these embodiments, the door itself may be included as a part of the device. FIG. 10 depicts two views of a device demonstrating such an embodiment. FIG. 10a shows the housing 24 in the second 27 of a plurality of positions; this position allows the user access to the structure 232. In this illustration, the structure 232 is a door handle on a door. FIG. 10b illustrates the housing 24 in the first 25 of a plurality of positions; this position allows sterilization of the structure 232. FIG. 10b shows the frame 20 upon which the housing moves. Both FIG. 10a and 10b exemplify an embodiment in which the motion detector 28 is not contained directly on or within the housing 24, but is in a position more remote. FIGS. 10a and 10b also illustrate an embodiment in which the power is provided by a connection 40 that is not contained on or within the housing 24, but is connected within the device by the door. [0048] FIG. 11 shows a front view of one embodiment of the invention in situ on a door. In this illustration, the housing 24 comprises a transparent material 24b to allow the user to view the structure (in this case, a door handle) during sterilization without being exposed to UV radiation. The UV radiation source 26 is contained within the housing 24 in this example. The housing 24 is mounted on the frame mount 21b. Various mechanical components 41 may be mounted on the frame mount. The power connection 40 in this example is connected directly to the device, but not directly to the housing 24.

[0049] Devices according to the present invention have varying sizes and shapes, such that the devices properly fit over a particular structure that is chosen to be sterilized. This ability to modify the size and/or shape of the device 10 also allows for better control of the positioning of the UV radiation source 26 in relation to a specific structure. In this manner, the device will be able to adequately sterilize all appropriate surfaces of the structure. For example, in FIG. 7, the device 200 is designed to fit the door handle over which it is installed. In the aspects of the invention shown in Figures 1-10, the housing is shown as a cylindrical housing having a semicircular cross section. It is envisioned that the shape of the housing may vary, for example, depending upon the size and shape of the structure to which the device is mounted. This will be readily apparent to those skilled in the art.

[0050] As described supra, the sliding of the housing 24 may utilize a linear (lateral) motion in some embodiments, as opposed to a rotational motion. This linear (lateral) motion may be desirable for the safety of the user and accessibility to the structure 232, especially in those instances in which the structure 232 is a door handle. The sliding linear (lateral) motion of the housing 24 allows for a user to easily move or push the housing out of the way. A linear (lateral) motion is more efficient than a rotational motion, covering the same area in a shorter distance, as shown below:

This linear (lateral) motion may allow not only for a safer product, but also for quicker and more effective sterilization.

[0051] It may be important to move any and all obstructions away from the handle to facilitate operation and accessibility. In some embodiments, the device may include a release slide mechanism, which allows a user to easily move or push the housing out of the way and have it remain out of the way in case of an emergency, regardless of its position. In some embodiments, the release slide mechanism is designed to work in the case of blockage of the handle, a problem with the power source or a power failure and/or the complete failure for the motion sensor.

[0052] In some embodiments, the device permits the user to access the door regardless if there is a sterilization cycle in process. In these embodiments, when the device detects motion, the housing will slide away from the door handle. In some embodiments, the device contains a microcontroller for the programming and storing of its software. In some embodiments, the software may serve to control the movement of housing in relation to the sterilization cycle and may also have safety override functions to keep users safe from exposure and bodily injury. For instance, if the door handle is blocked or, as above, in case of a power failure, the software may allow the handle to stay exposed so that it can be utilized by the user. The software may allow the device to be programmed to effect these emergency procedures under a variety of conditions, for instance, after a certain time without power. In some embodiments, software may allow the device to record the number of sterilization cycles during the lifetime of the device.

[0053] In some embodiments, the device may incorporate radio-frequency identification to trigger the movement of the housing whenever a specific user is present. The radio -frequency identification may also be used track the number of times the user enters the room giving date, time and specific identification.

[0054] In some embodiments, the device 10 may incorporate an indicator and/or a material that is sensitive to varying wavelengths of UV light. In some embodiments, the device 10 may include a polymer indicator that changes color as a result of UV exposure. This color change may demonstrate to the user that the sterilization cycle is complete and that it has been successful. In some embodiments, this polymer indicator may be part of the housing 24. In some embodiments, the polymer indicator may be a transparent material 24b that also blocks UV radiation from escaping the chamber, as illustrated in FIG. 11. In other embodiments, the polymer indicator may be a polymer layer contained within the housing 24.

Examples

Light Parameter Characterization

[0055] An embodiment of the invention (called "SI" for purposes of this disclosure) was tested in various characterization tests. The first test measured the physical properties of the light source and evaluated the impact of the relative position of the light source on sterilization. A digital UVC meter was used to measure the amount of light shining in the housing of the S 1 as well as the amount of light leaking from the housing, that is the intensity of the light inside and outside of the sterilization housing of the S 1. The S 1 device was turned on and the digital UVC meter was inserted in the housing to record the light intensity. The intensity of light recorded at different points (positions) of the housing allowed for the determination of the total intensity of UVC currently generated within the device. Three representing sites were selected and averaged for the intensity of light within the device: The top, the middle and the bottom of the device. At each of these three sites the UVC meter was oriented to face the light source from the front, the left and the right sides. Then the amount of light measured was recorded.

[0056] Another evaluation consisted of the measurement of the intensity of light that may pass through the transparent front and through the partially open bottom of the housing of the device. To perform the measurement at the bottom of the housing, a homemade door handle was designed to provide room for the insertion of the digital UVC. The measurements were recorded on a spreadsheet for different time points and positions. The intensity of light leaking from the sides of the device and from the open bottom (door handle entry point) was estimated per surface area, allowing for monitoring the changes of the light intensity over time.

[0057] Table 1 lists the intensities recorded for each site.

Table 1 : Measurement of the intensity of UVC light inside the sterilization unit (in μW/cm )

[0058] The intensity of the UVC light inside the sterilization unit was averaged based on the reading for all the sites. The average amount of the UVC irradiation for the whole sterilization unit was 706 μW/cm . The amount of light leaking from the device was also evaluated after measurement around the unit. Table 2 describes the amount of light detected in the immediate environment around the device.

Table 2: Measurement of the intensity of UVC light in the immediate environment of the sterilization unit (in μW/cm )

[0059] These results suggest that with S 1 , the leakage is significant only from the bottom side of the device. Compared to the amount of irradiation produced within the device, the SI device prevented leakage by 99.5%. However, the leakage became completely insignificant at a distance of approximately 4cm from the device, as shown in Table 3. The amount of irradiation detected is about 0.02% what is emitted within the device.

Table 3: Measurement of the intensity of UVC light at 4cm around the sterilization unit (in μ^{^}^ι ²) Right side Bottom side Left side Top side Front side

Measurement 1 0 82 0 8 0

Measurement 2 0 79 0 8 0

Measurement 3 1 102 1 7 0

Average 0.333 87.667 0.333 7.667 0

Efficacy of the S 1 in Killing Pathogens

[0060] The S 1 device was tested for its ability to kill relevant clinical models of

microorganisms. Hence, Bacillus cereus (spores), Staphylococcus aureus (MRS A),

Pseudomonas aeruginosa, Candida albicans and Klebsiella pneumoniae were exposed to various intensities of UVC light to investigate their resistance to the germicidal irradiation. P.

aeruginosa was used as a model for Gram-negative bacteria. S. aureus, a medical relevant Gram- positive bacterium, was chosen because of its ability to cause bacterial outbreak and develop multi-drug resistance. K. pneumonia was chosen because cells from this strain aggregate and form biofilm-like clusters. This was a good model to evaluate earlier stage bio film formation on surfaces. B. cereus was a very interesting model to evaluate resistance of spore forming strains to our device. Finally, C. albicans which is a medical relevant fungus was also involved in the study for the efficacy of the SI device. The effectiveness of the sterilization was monitored as a function of the distance and time of sterilization. Initially, the microbial cells were cultured in 20 mL LB medium overnight at 37°C with shaking. All the cultures were normalized to a cell suspension with a density at OD₆oo of 0.5. A model door handle was inoculated with a heavy load of the model pathogens. The inoculation was performed by swabbing the cultures on 3 preselected areas of the door handle (Position 1 : top base of handle, Position 2: middle shaft of handle, Position 3: bottom base of handle). Before the UVC treatment, pieces of gauze wetted with Tryptic Soy Broth (TSB) was used to swab the three selected areas for initial (baseline) cell quantification. The pieces of gauze were then introduced into a tube containing 5mL of TSB and vortexed to allow for the cells to break free from the gauze and re-suspend in solution. Then 0.5 mL cell suspensions, as well as a 10^th dilution cell suspensions were plated on Blood-agar. The UVC treatment was performed using the SI device with additive interval cycles of 25 sec. The three intervals used were 1 cycle=25sec, 2 cycles=50sec and 4cycles=100sec. At each time interval, the gauze was used to swab the three inoculated sites post UVC exposure. The pieces of gauze were then introduced into a tube containing about 5mL of TSB and vortexed to allow the cells to break free from the gauze and re-suspend in solution. The cell suspensions, as well as their respective 10^th dilutions, were plated on Blood-agar. Each microbial strain was treated similarly. After the treatment of each strain, the door handle was sterilized using 70% ethanol. Then another strain was inoculated on the door handle and the steps above were repeated for each organism. All the strains were plated on blood-agar and incubated for 48h at 37°C. The results were compared to the untreated control samples to estimate the extent of the sterilization with the S 1 system.

[0061] Model organisms of bacteria and fungus with medical relevance were used to evaluate the efficacy of the SI -beta prototype. S. aureus (including MRS A), P. aeruginosa, C. albicans and K. pneumoniae and B. cereus (including spores) were treated with UVC light intensity comprised between 75 -1300 μW/cm for 25, 50 and 100 sec. The samples were treated at different location on the door handle labeled as position 1, position 2 and position 3. The positions represented the top, the center and the bottom of the sterilization unit with a respective UVC intensity 1319, 75 and 725 μW/cm (Table 1). The data of the treated samples were compared to the initial cell load. As shown in FIG. 12, 100% killing of Bacillus cereus cells was achieved in 50 sec. The treatment was effective on all the surfaces.

[0062] The elimination of Candida albicans cells required more UVC exposure. After 100 sec of UVC treatment with various intensities, more than 99.9% of the cells were killed at positions 1 and 2, and at position 3, no cells survived the UVC dose at 100 sec (FIG. 13).

[0063] As shown in FIG. 14, the treatment of K. pneumonia with UVC light was also effective, especially at position 2. Cells with an initial count of 10,000 cells/mL were all eliminated from the surface of the door handle after 100 sec. At the other locations, the cell count was reduced by 90 to 99.9%) (location 3 and location 1 respectively).

[0064] The initial load of Pseudomonas aeruginosa on the door handle was equivalent to 10⁵ cells/mL for an OD₆oo of 0.5. The cells were spread on the door handle to evaluate the efficacy of the UVC treatment using the SI sterilization system. After a treatment of lOOsec, more than 99.99%) of the cells were reduced from locations 1 and 2. However, the treatment was less effective on the bottom of the door handle. At this location, about 9% of the cells survived the treatment (FIG. 15). The killing of P. aeruginosa was very similar to this of S. aureus.

[0065] As shown in FIG. 16, more than 99% of the total population of S. aureus seeded at the different locations of the door handle was killed in just 50 sec. Another addition log killing was achieved with the treatment for 100 sec. Similarly to the previous killing curves, the treatment of the latter strain with UVC light was more effective in the center of the device. In that condition, the cells were rapidly killed after 50 sec.

[0066] The measurement of the light intensity has shown that no significant leakage at 4 cm around the device, making the SI device very safe for public use. The level of UVC generated within the SI device was sufficient enough to eliminate gram negative bacteria, gram-positive bacteria, spore forming microbes and monolayer of cell clusters. Also, killing of fungi was achieved with SI device. Because of the high interaction between human subject and medical surfaces, the automated sterilization with the S 1 device can be adjusted to satisfy the need of sterilization (time and UVC dose).

[0067] While several aspects and embodiments of the present invention have been described and depicted herein, alternative aspects and embodiments may be affected by those skilled in the art to accomplish the same objectives. Accordingly, this disclosure is intended to cover all such further and alternative aspects and embodiments as fall within the true spirit and scope of the invention.

Claims

1. A device for sterilizing a structure, said device comprising:

a frame; and

a housing mounted to the frame, the housing containing a UV radiation source; wherein said frame is adapted to retain the housing in a plurality of positions, wherein, in a first of the plurality of positions, the housing is positioned wherein the UV radiation source illuminates and sterilizes at least a portion of the structure, and wherein, in a second of the plurality of positions, the housing is positioned to permit access to the structure.

2. A device according to claim 1, wherein the housing is slidably mounted to the frame.

3. A device according to claim 1, said device further comprising a motion detector

configured to detect movement within a predetermined distance from said device.

4. A device according to claim 3, said wherein said predetermined distance comprises a detection radius of between about 6 inches and about 15 feet.

5. A device according to claim 3, wherein said device is configured to slide the housing along the frame from the first position to the second position when motion is detected by the motion detector.

6. A device according to claim 1, wherein said housing comprises a cap plate configured to minimize UV radiation leakage from the housing.

7. A device according to claim 1, wherein said device is configured to receive power from a power source.

8. A device according to claim 7, wherein the power source is a source of conventional alternating current or direct current.

9. A device according to claim 1, wherein said device is configured to minimize UV radiation exposure to humans.

10. A device according to claim 1, wherein sterilizing comprises killing at least 95 % of the germs on the structure.

11. A device according to 10, wherein sterilizing comprises killing at least 99.9% of the germs on the structure.

12. A device according to claim 1, wherein said UV radiation source comprises one or more UV lamps.

13. A device according to claim 1, wherein said UV radiation source emits ultraviolet

radiation having a wavelength of between 100 nm and 280 nm.

14. A device according to claim 13, wherein said UV radiation source emits ultraviolet

radiation having a wavelength of between 240 nm and 280 nm.

15. A device according to claim 1, wherein the structure is a door handle.

16. A method of sterilizing a structure, said method comprising:

mounting the device according to any one of claims 1 to 15 over the structure; and illuminating and sterilizing at least a portion of the structure with the UV radiation source provided in the device.

17. A method according to claim 16, wherein mounting the device positions the housing in a first position, and wherein the method further comprises moving the housing to a second position, different from the first position.

18. A method according to claim 17, wherein moving the housing to a second position comprises sliding the housing along the frame from the first position to the second position.

19. A method according to claim 16, wherein the method further comprises detecting motion within a detection radius of between 6 inches and about 15 feet.

20. A method according to claim 16, wherein the structure is a door handle.

21. A method according to claim 16, wherein said method sterilizes the structure while minimizing UV radiation exposure to humans.

22. A method according to claim 16, wherein said UV radiation source emits ultraviolet radiation having a wavelength of between 240 nm and 280 nm.

23. A method of sterilizing a structure, said method comprising:

mounting a frame having a movable housing in a first position substantially concealing the structure, the housing having a UV radiation source;

illuminating and sterilizing at least a portion of the structure with the UV radiation source;

detecting movement in a vicinity of the housing; and

when movement is detected, moving the movable housing along the frame from the first position to a second position, different from the first position, to at least partially expose the structure.

24. A device according to any one of claims 1-15, wherein the housing moves in a linear motion.

25. A method according to claim 17 or claim 23, wherein the housing moves from the first position to the second position in a linear motion.