US20180236115A1 - Apparatus and method for sanitizing articles - Google Patents

Abstract

An apparatus is provided for sanitizing an article, the apparatus comprising a housing defining an enclosed internal chamber and having an opening at a door side into the chamber. A door is configured to selectively close the door side of the housing for substantially sealing the chamber. A UV light source is disposed internally of the housing for irradiating the chamber, and an electronic circuit is electrically connected to the UV light source and adapted to power the UV light source for a predetermined period of time. A reflector unit is disposed on one of the walls, the reflector unit including a reflective section projecting outwardly at an angle with respect to the wall. With the article placed in the chamber and the door closed and the electronic circuit activated, the UV lamp is illuminated for the predetermined period of time for sanitizing the article.

Description

Related Applications
• This application is a continuation application of U.S. patent application Ser. No. 15/082,027, filed Mar. 28, 2016, which is a continuation application of U.S. patent application Ser. No. 13/431,632, filed Mar. 27, 2012, now U.S. Pat. No. 9,295,741, the contents of both of which are incorporated herein by reference.
• This application is related to U.S. patent application Ser. No. 12/512,766, filed on Jul. 30, 2009, now U.S. Pat. No. 8,143,596, which claims the benefit of U.S. Provisional Patent Application No. 61/268,365, filed on Jun. 11, 2009, all of which applications and patent are incorporated herein by reference in their entirety.
BACKGROUND
• An apparatus and method for sanitizing articles is described and, more particularly, an apparatus and method using ultraviolet light for sanitizing articles between uses, such as medical instruments, tools and objects, patient-care items, and the like.
• Ultraviolet (UV) light of a particular range of wavelengths, intensities, and durations can kill or inhibit growth of microorganisms. Specifically, ultraviolet radiation in the range of 200 nanometer (nm) to 300 nm is effective against airborne and surface bacteria, viruses, yeasts, and molds. For most microorganisms, the peak inactivation wavelength is at or about 260 nm. Mercury lamps produce UV light very efficiently at 254 nm and, therefore, this wavelength has become the standard UV germicidal light wavelength.
• UV light is used in healthcare facilities to disinfect surgical theaters and operating rooms. UV light is also used extensively in air and water purification applications in the food and beverage industry and in sewage treatment. UV light can also be used to disinfect patient-contact items like stethoscopes, thermometers, blood pressure cuffs, and oximeters, as well as doctor and staff-carried items such as cell phones, eMARs scanners, penlights, scissors, PDAs/tablets/laptops, and other easily contaminated, and difficult-to-disinfect items. UV light can also disinfect hand-held and portable electronic devices and other personal articles, including mobile (cellular) telephones, portable music and video players (e.g., MP3 and MP4 players), cameras, portable global positioning devices, and the like.
• In conventional UV sanitization devices, the UV radiation sources are stationary or portable and can range in size from very large devices to small hand-held wands. However, a problem associated with UV sanitization is most articles or implements requiring sanitization will have interior spaces and non-planar surfaces. Some will have multiple invaginations which can harbor microbes, such as reusable grocery bags, sporting equipment including helmets and shoes, and the like. Typically, UV sanitization devices are inadequate to irradiate the non-planar surfaces of articles at varying distances from the UV radiation sources. As a result, some surfaces of the articles are not reached by UV irradiation.
• For the foregoing reasons, there is a need for a new device for sanitizing articles, particularly articles having an interior space and non-planar surfaces that are difficult to reach with conventional UV irradiation.
Summary
• An apparatus is provided for sanitizing an article, the apparatus comprising a housing including a plurality of walls defining an enclosed internal chamber and having an opening at a door side into the chamber. A door is configured to selectively close the door side of the housing for substantially sealing the chamber. A UV light source is disposed internally of the housing for irradiating the chamber, and an electronic circuit is electrically connected to the UV light source and adapted to power the UV light source for a predetermined period of time. A reflector unit is disposed on at least one of the walls, the reflector unit including a reflective section projecting outwardly at an angle with respect to the at least one of the walls. With the article placed in the chamber and the door closed and the electronic circuit activated, the UV lamp is illuminated for the predetermined period of time for sanitizing the article.
BRIEF DESCRIPTION OF THE DRAWINGS
• For a more complete understanding of the present invention, reference should now be had to the embodiments shown in the accompanying drawings and described below. In the drawings:
• FIG. 1 is a front perspective view of an embodiment of a device for sanitizing articles with a door in a closed position.
• FIG. 2 is a front elevation view of the sanitizing device shown inFIG. 1 with the door in an open position.
• FIG. 3A is a longitudinal cross-section view of the sanitizing device shown inFIG. 1 taken alongline3A-3A ofFIG. 2.
• FIG. 3B is a longitudinal cross-section view of the sanitizing device shown inFIG. 3A with the mesh cages removed.
• FIG. 4 is a close-up cut-away perspective view of an embodiment of reflector units on a bottom surface of the sanitizing device shown inFIG. 2.
• FIG. 5 is a cross-section view of the sanitizing device shown inFIG. 1 taken along line5-5 ofFIG. 2.
• FIG. 6 is a side elevation view of an embodiment of a reflector unit for use in the sanitizing device shown inFIG. 1.
• FIG. 7 is a cross-section view of the sanitizing device shown inFIG. 1 taken along line7-7 ofFIG. 2.
• FIG. 8 is a perspective of an embodiment of a tray for use in the sanitizing device shown inFIG. 1.
• FIG. 9 is a rear elevation view of the sanitizing device shown inFIG. 1 with a partial cover panel removed.
• FIG. 10 is a top plan view of the sanitizing device shown inFIG. 1.
DESCRIPTION
• Certain terminology is used herein for convenience only and is not to be taken as a limitation on the invention. For example, words such as “upper,” “lower,” “left,” “right,” “horizontal,” “vertical,” “upward,” and “downward” merely describe the configuration shown in the FIGs. Indeed, the components may be oriented in any direction and the terminology, therefore, should be understood as encompassing such variations unless specified otherwise.
• As used herein, the term “article” is deemed to mean any portable, potentially contaminated object or item of porous or non-porous material suspected to be a fomite or vector of pathogens and disease transmission.
• As used herein, the terms “bulb” or “lamp” is deemed to mean any source of UV light.
• As used herein the terms “disinfect” and “sanitize” is deemed to mean the expectation that bacterial count will be substantially reduced on objects and items irradiated with UV light.
• As used herein, the term “reflector unit” means a collection of reflective structures that together reflect at least 60% of light having a frequency between 100 nm to 290 nm.
• A device for sanitizing an article is shown inFIG. 1 and generally designated at20. Thesanitizing device20 comprises ahousing22 constructed of a material that is impervious to UV radiation. In one embodiment, thehousing22 is formed from polished, reflective aluminum sheeting. Thehousing22 is substantially cube-like in shape, including apartial front wall24 defining an opening26,side walls28, and an innerrear wall30 and an outer rear wall31 (not visible inFIG. 1). Thewalls24,28,30,31 of thehousing22 are joined adjacent their edges by aceiling32, aroof35 spaced from the ceiling and afloor34. The opening26 in thefront wall24 is sealed by a slidingtambour door36, which provides access to inside thehousing22. Optionally, thehousing22 can include a UV-resistant viewing window39 that allows a user to view the inside of the sanitizingdevice20 during operation while avoiding exposure to UV radiation. Thehousing22 is sized and shaped to receive an article to be sanitized. The dimensions of thehousing22 may be determined by the field of use. In the embodiment shown in the FIGs., thesanitizing device20 may be placed on acart37 for mobility of the device. Alternatively, the sanitizingdevice20 can be mounted to a wall or placed on a table or on the ground. It is understood that the size of thehousing22 or theopening26 can vary depending on the article to be disinfected. All commercially viable sizes are contemplated.
• Referring toFIG. 2, thehousing22 defines an openinterior chamber38 formed by the inner surfaces of the front andside walls24,28, the inner surface of the innerrear wall30, and inner surfaces of theceiling32 and thefloor34. Theopening26 in thefront wall24 allows the user to access thechamber38 for inserting and removing articles to be sanitized. Thechamber38 is configured to accommodate at least one source of UV radiation with a wavelength and intensity suitable for sanitization of the article. The sanitizingdevice20 may further comprise one or more means for supporting articles to be sanitized. In addition, one ormore reflector units40 project upwardly from thefloor34 for reflecting UV light from theUV lamps42 upwardly toward the articles disposed within thechamber38. As described in more detail below, thereflector units40 provide a more thorough and uniform distribution of UV light to all surfaces within thechamber38, and in particular, the underside of the article supporting means and the articles.
• Thedoor36 is made of, or includes a layer, lining, or coating of, a material that is substantially opaque to UV radiation. Thedoor36 is slidingly received in atrack44 formed in thefront wall24 of the housing22 (FIGS. 3A and 3B). Thedoor36 is slideable in thetrack44 for moving between an open position (FIG. 2) wherein articles can be inserted into, or removed from, thechamber38, and a closed position (FIG. 1) wherein thechamber38 is closed so as to substantially prevent the escape of ultraviolet radiation from thechamber38. Ahandle46 of antimicrobial copper alloy may be provided on thedoor36 for moving thedoor36 between the open position and the closed position. A suitable light seal can be provided at a junction where thefront wall24 of thehousing22 and the leading edge of thedoor36 engage when thedoor36 is in the closed position. The seal may include any suitable material which inhibits the passage of light, such as a rubber or a felt gasket, or thedoor36 may have a close or overlying fit between thedoor36 and thefront wall24 of thehousing22.
• Although thedoor36 is shown as a tambour door, it is contemplated that thedoor36 could alternatively be a hinged door or any other commercially suitable configuration. For example, the hinged door may be attached to thehousing22 by hinges disposed between the adjacent edges of thehousing22 and the door that allows the door to be selectively opened and closed.
• The inner surfaces of thewalls24,28,30, thefloor34 and theceiling32 of thehousing22 are provided with a reflective material. A suitable material is aluminum, and more particularly, polished aluminum. Other metals may be used, such as polished zinc or stainless steel. Alternatively, a reflective coating may be placed on the inner surfaces of thewalls24,28,30,floor34 andceiling32, such as magnesium carbonate. The reflective surfaces reflect the emitted UV radiation in order to ensure that all surfaces of the article to be irradiated receive comparable amounts of UV irradiation. In practice, a reflectivity in excess of 65% is desirable. In one embodiment, a polished aluminum can achieve up to 97% reflectivity, a polished zinc surface can achieve about 80% reflectivity, while the correct selection of magnesium carbonate/oxide coating can achieve about 70% reflectivity. The reflective inner surfaces of thewalls24,28,30, thefloor34 and theceiling32 of thehousing22 can be smooth, or if desired, may be a sculptured or otherwise non-planar configuration to enhance or direct the reflected radiation. In one embodiment, the inside surface of thedoor36 may also be provided with a reflective material.
• As shown inFIGS. 4 and 5, thefloor34 of thehousing22 includes a plurality of spacedreflector units40. Referring toFIG. 6, each of a pair of sides of areflector unit40 includes at least three sections, aprimary wall section48, a firstend wall section50, and a secondend wall section52. The first and secondend wall sections50,52 extend angularly inwardly from theprimary wall section48. Each of the threewall sections48,50,52 extending upwardly from thefloor34 and are disposed off normal with respect to thefloor34. The angle (H) between thefloor34 of thehousing22 and each of thewall sections48,50,52 is at least about135 degrees. Thewall sections48,50,52 are joined at an apex of thereflector unit40 forming an elongated pyramidal projection such that, when viewed from the front, thereflector unit40 appears to have a triangular shape. In alternative embodiments, thereflector unit40 could include four or more wall sections and be formed of shapes such that, when viewed from the front, thereflector unit40 appears to have a square, rectangular, pentagonal, hexagonal, or any other commercially viable shape. Of course, depending on the shape of thereflector unit40, the shape and number of reflective wall sections will likely vary.
• Thereflector units40 can be composed of the same reflective material as the inner surfaces of thewalls24,28,30 of thehousing22. Alternatively, thereflector units40 can be one or more commercially suitable materials, including, for example, mirrors, powder-coated and other metal sheets. Thereflective wall sections48,50,52 could also be dimpled or bumpy.
• Thereflector units40 are positioned on thefloor34 with respect to theUV lamps42 so that at least some UV radiation that would otherwise be emitted by the UV light sources in a direction other than at the articles is reflected upwardly toward the articles. Specifically, the longitudinal axis of thereflector units40 adjacent the front and rear of thechamber38 is aligned with the mid-line C (FIG. 5) between theside walls28 of the chamber. The intermediate V-shapedreflector unit40 is positioned such that a line extending between each of the pairs of opposite corners of thehousing22 would be perpendicular to theprimary wall sections48 of theintermediate reflector unit40.
• With this arrangement of thereflector units40, the UV radiation intensity on the various surfaces of the article is more consistent, which increases the efficiency of use of the UV radiation and maximizes the exposure of all surfaces of the articles to the UV radiation. The result is a sanitizingdevice20 requiringfewer UV lamps42 and a shorter duration of exposure to the UV light to disinfect the article. It is understood that thereflector units40 can be disposed at any position on the inner surface of thewalls24,28,30, theceiling32 or thefloor34 of thehousing22 to achieve this result. All commercially suitable configurations for thereflector units40 are contemplated, and such configurations will likely depend on the size and dimensions of thehousing22 and the articles to be irradiated.
• Any commercially suitable source of UV radiation is contemplated for use with thesanitation device20. The UV radiation source may include cold cathode UV tubes, LED's, and low, medium, or high vapor mercury lamps. The UV radiation source has a suitable wavelength that falls within the wavelength range of about 220 nm to about 300 nm, preferably at least substantially in the range of 235 nm to about 280 nm, and more preferably about 250 nm to about 275 nm. In this range, the UV radiation is highly effective against microorganisms.
• In the embodiment shown inFIGS. 2, 3B and 7, the source of UV radiation includes a plurality of elongatedfluorescent UV lamps42 disposed on an inner surface of thehousing22 and positioned to substantially irradiate theinterior chamber38 and any article in the chamber. A UV lamp that emits light within the preferred wavelength range and is suitable for use in the sanitizingdevice20 is a Model No. GTL 18 orGTL 24 high output, 72 watt UV germicidal lamp, available from American Ultraviolet Company of Lebanon, Ind. These UV lamps are 15 mm glass tubes with a single end power connector and a protective boot and are Teflon-coated for containment in case of breakage. In addition, these UV lamps produce UV light at an intensity of7200 μW/cm²at a distance of about twelve inches. The UV lamps are approximately 18 inches and 24 inches in length, respectively, including three inches attributed to the end connectors. Although the UV lamps are shown having elongated tubular bulbs, it is contemplated that other commercially suitable sources of UV light could be used of any convenient size or shape of UV lamp or bulb may be employed. Even a plurality, or a bank, of UV LED's may be employed, as long as they emit the proper wavelength of UV light.
• The plurality ofUV lamps42 are attached to pairs oftube holders78 and depend from the inside surface of each of theside walls28, the innerrear wall30 and theceiling32 of thehousing22. TheUV lamps42 are oriented radially inward towards the center of thechamber38 so as to provide UV radiation from all directions to maximize the exposure of the articles within thechamber38. The UV lamps are spaced about 1½ inches from the inner surfaces of thehousing22. TwoUV lamps42 are provided on eachside wall28 extending generally vertically and are evenly spaced between thefloor34 and theceiling32. Thefront UV lamp42 on eachside wall28 is spaced about 4 inches from thefront wall24, and therear UV lamp42 on eachside wall28 is spaced about 8 inches from therear wall30. The front andrear UV lamps42 are spaced from each other about 10 inches on center. Thesingle UV lamp42 on therear wall30 is disposed along the central longitudinal axis of therear wall30 and is evenly spaced between theceiling30 and thefloor34. TheUV lamp42 on theceiling32 is disposed along the central longitudinal axis of theceiling32 and is evenly spaced between thefront wall24 and therear wall30. The distance from each of the UV lamps to a central plane passing through the middle of thechamber38 is about eleven inches. In one embodiment of the sanitizingdevice20 based on these relative dimensions, thereflector units40 may each be about 4 inches in length and project upwardly about ¾ inches from thefloor34 of thehousing22. The front end of thefront reflector unit40 is about ½ inches from the front wall of thehousing22 and the rear end of therear reflector unit40 is about three inches from therear wall30. For the V-shapedreflector unit40, the length of four inches is measured from the point of the “V” to each end.
• It is understood that theUV lamps42 could be disposed at non-right angles. It is further understood that the specific number, size, and orientations of each of theUV lamps42 will likely vary depending on the size and type of UV lamps used, the article to be disinfected, and the sizes and dimensions of thehousing22. TheUV lamps42 can be disposed in any suitable locations and oriented such that articles within thechamber38 are exposed to adequate amounts of UV radiation for sanitization. A wire meshprotective cage80 surrounds each of theUV lamps42.
• The article supporting means may comprise an article support suitable for use in the environment of thechamber38, such as a drawer, tray, shelf system, or receptacles for receiving and supporting articles within thehousing22. In the embodiment shown in the FIGs., the article supporting means is a plurality oftrays54 positioned at different levels in thechamber38. Referring toFIG. 8, eachtray54 comprises a platform disposed in a flat configuration. Thetray54 is formed from a light-transmissible material made of wire mesh or lattice such as, for example, 50 mm wire mesh. Thetray54 is configured to have some depth thereby defining a recess for accommodating the article.Opposed channels56 are provided on the inner surfaces of theside walls28. Elongated downwardlycurved flanges57 are positioned on opposite sides of thetrays54 for slidably receiving thechannels56. Ahook58 is provided on the back edge of thetray54. Thehook58 captures the wire mesh of thecage80 surrounding theUV lamp42 on therear wall30 to secure thetrays54 in an inserted position. Thetrays54 can be removed for cleaning or for loading articles on thetrays54.
• The relative positioning of theUV lamps42, thereflector units40, and thetrays54 is such as to ensure that all surfaces of the article and the upper and lower surfaces of thetrays54 are exposed to sufficient amounts of UV irradiation through the apertures of the wire mesh. The effect of “shadows” caused by the bars of the mesh coming between the lower surface of the article when supported on the mesh and the UV radiation are minimized. Thechannels56 andflanges57 are made of reflective material to further maximize the distribution of UV radiation. A minimal contact area between the article and the mesh of thetray54 may be acceptable.
• Referring now toFIG. 9, the outer surface of therear wall30 of the sanitizingdevice20 accommodates acontrol box60. Thecontrol box60 preferably has a removable cover panel (not shown) for allowing access to a circuit board supporting the wiring and circuitry for repair, removal, and replacement. The circuit board carries acontroller62 for controlling operation of the sanitizingdevice20 and apower supply64 for providing power to thecontroller62, such as electric cord and plug (not shown). Thepower supply cord64 is connected to atransformer66 to provide electrical power to the circuit. Thecontroller62 can control the delivery of power to theUV lamps42 to be turned on or off, as well regulating other electrical components of the sanitizingdevice20 including, for example, one or more sensors.
• Afirst sensor68 senses or detects whether thedoor36 is in the open position or the closed position and signals the controller to control operation of the sanitizingdevice20 accordingly. Alternatively, a sensor may be activated upon closing the door. The sensor can include, but is not limited to, one or more of a depression switch, electrical contacts, an optical sensor or other sensor known in the art for determining the relative positions of the door and thefront wall24 of thehousing22. In one embodiment, the sensor comprises a contact on thehousing22 and amagnet69 in thedoor36, the completed circuit activating the UV radiation source only when thedoor36 is in the closed position to enclose thechamber38. For example, the ultraviolet radiation source is disabled from emitting ultraviolet light when thedoor36 is in the open position and is enabled to emit ultraviolet light when thedoor36 is in the closed position.
• Each UV light source is electrically connected to an electronic ballast, which provides resistance to stabilize current in the circuit created when the sanitizingdevice20 is attached to a power source via thepower supply cord64. In a preferred embodiment, ballast is operational with 100/200 VAC at 50/60 HZ.
• In one embodiment, thecontroller62 activates the ultraviolet radiation source for a first predetermined period of time when thesensor68 senses that thedoor36 is in the closed position. The predetermined period of time may vary depending on the strength of the UV light source. In one embodiment of the sanitizingdevice20 using the72 watt UV lamps identified above, it is estimated that between about 30 and about 60 seconds would be sufficient to eliminate most bacteria present on an article. A timer is used to control the length of time the UV source is powered. Thecontroller62 automatically turns off the UV light source at the set time on the timer after, for example, the about 30 to about 60 seconds, and may include an audible signal (beep, chime, etc.) to let the user know the cycle is finished. The controller may in addition to, or alternately, activate the UV radiation source based on a signal from a manual interface, such as a switch70 (FIG. 1) or other interface located outside of the sanitizingdevice20 that a user can select to manually activate thecontroller62. A plurality of switches may also be provided, and additional functionality may be included, including different settings for different articles to be sanitized, different durations of the sanitization cycle, different power level intensities for the UV lamps, and the like.
• One or more indicator lamps or displays may be provided on the outside of thehousing22 to indicate the status of the sanitizingdevice20. For example, a lamp indicator light may show whether power is being sent to the sanitizingdevice20. A light82 may also be provided in the chamber38 (FIG. 7), which light82 is activated for the user when thedoor36 is in the open position. All other commercially viable safety systems are contemplated. For example, avent84 is provided between therear walls30,31 of thehousing22 and exits via theroof35. The sanitizingdevice20 could also require a key or security code be entered prior to activation.
• In operation, the user moves thedoor36 to the open position by rolling upwardly to expose thechamber38 and thetrays54. Thetrays54 are accessed by manually detaching thehooks58 and pulling thetrays54 outwardly. Thetrays54 slide along thechannels56 and may be completely removed. Articles to be irradiated are then placed on one or more of thetrays54. Thetrays54 are then returned to thechamber38 and pushed inwardly to the closed position by pressing on the front of thetrays54 and attaching thehooks58 to the wire mesh of thecage80. The user moves thedoor36 to the closed position to enclose the articles within thechamber38. Thesensor68 is activated upon closing of thedoor36 for signaling thecontroller62 that the door is in the closed position. The sanitizingdevice20 is activated by pressing theoutside switch70. Upon activation, thecontroller62 directs power to energize theUV lamps42 to sanitize the articles.
• When thesanitization device20 is activated, UV light is directed throughout thechamber38 and onto the articles to be disinfected. UV light is reflected off of the reflective inner surfaces of the walls and the surfaces of thereflector units40 ensuring exposure of all surfaces of the articles to UV light. The effect is UV light is directed from theUV lamps42 in all directions, including irradiating the underside of the articles through the apertures in thetrays54. The UV light kills significant amounts of microorganisms that may be on the articles, thereby sanitizing, or disinfecting, the articles. The articles are subjected to a dose of UV light corresponding to the UV light intensity as a function of time and distance of the UV lamps from the articles. Dose response levels are unique to each microorganism. Additionally, different wavelengths of UV light have different inactivation rates depending on the microorganism. It is understood that such process parameters are predetermined to affect the amount of radiation such that an article receives UV light sufficient to destroy microorganisms on the surfaces of the articles and to ensure a consistently effective reduction in microbial numbers.
• After a predetermined time sufficient to achieve a desired level of sanitization, thecontroller62 deactivates the UV radiation sources. When the sanitization cycle is completed, the display may indicate as such. If thesensor68 detects an attempt to open thedoor36 while the UV radiation sources are activated, the controller immediately shuts off power to the UV radiation sources.
• It is contemplated that the sanitizingdevice20 described and shown herein could be configured to sanitize all manner of articles and equipment including, for example, cosmetics or cosmetic implements such as eyeliner brushes and mascara brushes, and even small cosmetic items themselves such as personal items including compacts, and the like; kitchen utensils and tools such as cutting boards, and larger sized items including wheel chairs, strollers, and other sizes of shopping carts shopping baskets. Depending on the size and dimension of sanitizingdevice20, and the type of equipment to be disinfected, the number of reflective units, and their configurations, can be varied. Regardless of the article to be sanitized, the sanitizingdevice20 design allows for considerable adjustment of the amount of energy striking the article by selecting the number of lamps used, the distance of those lamps from the article, and the length of time that the article is exposed to UV light. The sanitizingdevice20 can conveniently and effectively disinfect articles in a short period of time.
• The sanitizingdevice20 described and shown herein was tested to determine the efficiency of the sanitizingdevice20 versus a concentration ofClostridium difficile(C. difficile),Staphylococcus aureus(S. aureus), andAcinetobacter baumannii(A. baumannii) using a 60 second exposure time and a 120 second exposure time. Microorganism preparation included inoculating tryptic soy agar (TSA) petri plates withS. aureusandA. baumanniiand incubating the plates for 22-26 hours at 30-35° C. Similarly, reinforced clostridial medium plus agar (RCM+ Agar) petri plates were inoculated withC. difficileand incubated for 46-52 hours at 30-35° C. in an anaerobic chamber containing an AnaeroGen Pak™.
• Serial dilutions of each culture were prepared in 7.2 pH buffer. Next, 0.1 mL of 10³CFU/mL concentration of each organism were plated in duplicate and incubated as described above. The concentration of each organism was calculated by multiplying the count acquired by 10 due to the 10⁴CFU/mL dilution being used for spiking.
• Pre-poured plates were then spiked. Specifically, 18 TSA plates were inoculated with 0.1 mL of 10⁴CFU/mL ofS. aureusand spread with a sterile hockey stick and another18 TSA plates were inoculated with 0.1 mL of 10⁴CFU/mL ofA. baumanniiand spread with a sterile hockey stick. Similarly, 18 RCM+ Agar plates were inoculated with 0.1 mL of 10⁴CFU/mL ofC. difficileand spread with a sterile hockey stick.
• The organism-spiked plates were then placed in the sanitizingdevice20 on each of the top, middle and bottom trays. On the top tray, plates were placed at the right front, back middle and left back of the tray. On the middle tray, plates were placed at the right back, middle and left middle of the tray. On the bottom tray, plates were placed at the right middle, middle, and left front of the tray. Lids were removed from the plates and the plates set agar side up. The sanitizingdevice20 was activated for 60 seconds. The sanitizing device was deactivated and the lids replaced on the plates and the plates removed. These steps were repeated for each organism.
• In a second run, the organism-spiked plates were in the sanitizingdevice20 on each of the top, middle and bottom trays. On the top tray, plates were placed at the middle front, left back and right back of the tray. On the middle tray, plates were placed at the middle back, middle and left front of the tray. On the bottom tray, plates were placed at the right front, middle front, and left back of the tray. Lids were removed from the plates and the plates set agar side up. The sanitizingdevice20 was activated for 120 seconds. The sanitizing device was deactivated and lids replaced on the plates and the plates removed. These steps were repeated for each organism.
• The UV treated plates of S. aureus and A. baumannii were incubated at 30-25° C. for 44-52 hours. The UV treated plates of C. difficile were incubated at 30-35° C. for 44-52 hours in an anaerobic jar containing an AnaeroGen Pak™. The organism spike count from untreated plates served as a positive control to confirm that TSA and RCM+ Agar media supported the correct bacterial growth. An un-spiked TSA plate and an un-spiked RCM+ Agar plate were also incubated to confirm that the plates were not contaminated.
• The percent kill of each organism for each exposure time was calculated by dividing the count after the exposure to UV light by the original concentration of the organism and then multiplying by100. Log₁₀reduction of each organism for each exposure time was calculated by converting each organism count to a log₁₀number. For example, 213 CFU/mL equals 2.33 Log₁₀. The Log₁₀decrease of each organism for each exposure time was found by calculating the difference between the Log₁₀of the original concentration of the organism and the Log₁₀after the 60 and 120 second exposure to UV.
• The sanitizingdevice20 for all plates at all locations and for both exposure times achieved a 100% killing ofS. aureusandA. baumannii. The sanitizingdevice20 for all plates at all locations and for both exposure times achieved a 100% killing ofC. difficile, except for the middle tray at the middle and left middle locations, which achieved 99.9% reduction in the organism. Converting the organism counts to a Log₁₀number, the reduction inS. aureusat all locations was 5.80 log₁₀and the reduction inA. baumanniiat all locations was 6.15 log₁₀. Although one colony of was found on two of theC. difficileplates from the 120 second exposure study, the log₁₀of 1 is 0 so the log₁₀reduction for all locations was 4.00.
• Although the apparatus and method for sanitizing articles has been shown and described in considerable detail with respect to only a few exemplary embodiments thereof, it should be understood by those skilled in the art that we do not intend to limit the invention to the embodiments since various modifications, omissions and additions may be made to the disclosed embodiments without materially departing from the novel teachings and advantages of the invention, particularly in light of the foregoing teachings. Accordingly, we intend to cover all such modifications, omission, additions and equivalents as may be included within the spirit and scope of the invention as defined by the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures.

Claims (8)

We claim:

1. An apparatus for sanitizing an article, the apparatus comprising:

a housing including a plurality of walls defining an enclosed internal chamber and having an opening at a door side into the chamber;

a door configured to selectively close the door side of the housing for substantially sealing the chamber;

a UV light source disposed internally of the housing for irradiating the chamber;

an electronic circuit electrically connected to the UV light source and adapted to power the UV light source for a predetermined period of time; and

a reflector unit disposed on at least one of the walls, the reflector unit including a reflective section projecting outwardly at an angle with respect to the at least one of the walls,

wherein with the article placed in the chamber and the door closed and the electronic circuit activated the UV lamp is illuminated for the predetermined period of time for sanitizing the article.

2. The apparatus for sanitizing an article as recited inclaim 1, further comprising a tray configured to be received in the chamber of the housing, the adapted for supporting the article.

3. The apparatus for sanitizing an article as recited inclaim 2, wherein the tray comprises a wire mesh.

4. The apparatus for sanitizing an article as recited inclaim 1, wherein the UV light source provides an intensity of about 7200 μW/cm²of UV light at about one foot.

5. The apparatus for sanitizing an article as recited inclaim 1, the reflective section of the reflector unit is angled with respect to the wall by at least about 135 degrees.

6. The apparatus for sanitizing an article as recited inclaim 1, wherein the plurality of the walls of the housing comprises a front wall and an opposite rear wall, a pair of side walls interconnecting the front wall and the rear wall, a floor interconnecting the lower edges of the front wall, the rear wall and the side walls, and a ceiling interconnecting the upper edges of the front wall, the rear wall and the side walls.

7. The apparatus for sanitizing an article as recited inclaim 6, wherein the UV light source extends along the rear wall.

8. The apparatus for sanitizing an article as recited inclaim 6, further comprising a plurality of UV light sources extending along the plurality of the walls of the housing.

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