Patent Document

FIELD OF THE INVENTION 
       [0001]    The present invention relates to sterilization using Ultra-Violet (UV) radiation and, more particularly, to a wand-type UV sterilizer. 
       BACKGROUND 
       [0002]    The anti-microbial properties of UV-C light (Ultraviolet light-C band) are well-known to scientists and have been used since the 1930&#39;s to kill germs containing DNA and RNA (including bacteria, viruses, fungi and mold). UV-C light is invisible to the human eye. While UV-C light is invisible, given sufficient intensity and exposure, UV-C light can kill most of the germs responsible for causing disease in humans and animals. UV-C light can destroy the DNA and/or RNA (genetic material) of pathogens (disease-causing bacteria, viruses, mold, etc.). Once the DNA in a pathogen has been destroyed, the pathogen is either killed or deactivated; the pathogen can no longer function properly; and the pathogen can no longer reproduce. 
         [0003]    Box-type UV sterilizers are well known for use in sterilizing all manner of objects including contact lenses, combs and safety goggles. Often only a single source of radiation is employed and, as such, there are often areas on an object to be sterilized that are shadowed from the UV radiation produced from the single source. Furthermore, the object to be sterilized is often required to rest on a support during the sterilization process. If the support is not transparent to the UV radiation, the support also contributes to shadowing the object to be sterilized from the UV radiation. 
       SUMMARY 
       [0004]    A germicidal wand helps eliminate disease-causing bacteria, viruses and fungi in a given environment. The wand-type Ultra-Violet (UV) radiation sterilizer allows a user to control the location of application of UV radiation and, thereby, sterilize areas on an object that may be shadowed when using a device with a fixed radiation source. The sterilizing wand includes a housing having an aperture and a source of UV radiation mounted within the housing positioned for emitting UV radiation through the aperture. Advantageously, the lamp chamber within which the source of UV radiation is mounted has an ingress and an egress so that an air flow may be promoted through the lamp chamber to cool the lamp and, thereby, allow for a lamp of higher UV power output than would otherwise be practical. 
         [0005]    In accordance with an aspect of the present invention there is provided a sterilizing wand. The sterilizing wand includes a housing having a lamp chamber, the lamp chamber having an ingress and an egress in communication with an exterior of the housing, and an aperture in communication with the lamp chamber, the aperture positioned between the ingress and the egress. The sterilizing wand also includes a pane of filtering glass for covering the aperture, a C-band Ultra-Violet radiation source, mounted in the lamp chamber between the ingress and the egress, for emitting C-band Ultra-Violet radiation through the pane of filtering glass and an impellor installed in the lamp chamber for promoting a flow of air into the ingress from the exterior of the housing, past the C-band Ultra-Violet radiation source and but of the egress. 
         [0006]    Other aspects and features of the present invention will become apparent to those of ordinary skill in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    In the figures which illustrate example embodiments of this invention: 
           [0008]      FIG. 1A  illustrates a rear elevation view of a sterilizing wand according to an embodiment of the present invention; 
           [0009]      FIG. 1B  illustrates a rear elevation view of the sterilizing wand of  FIG. 1A  with an aperture cover removed to expose a pair of bulbs; and 
           [0010]      FIG. 2  illustrates a front elevation view of the sterilizing wand of  FIG. 1 ; 
           [0011]      FIG. 3  illustrates a side sectional view of the sterilizing wand of  FIG. 1 ; 
           [0012]      FIG. 4  illustrates a bottom plan view of the sterilizing wand of  FIG. 1 ; 
           [0013]      FIG. 5A  illustrates an LED display of the sterilizing wand of  FIG. 1  in a Standby mode; 
           [0014]      FIG. 5B  illustrates the LED display of the sterilizing wand of  FIG. 1  in a Safety mode; 
           [0015]      FIG. 5C  illustrates the LED display of the sterilizing wand of  FIG. 1  in a Basic mode; and 
           [0016]      FIG. 5D  illustrates the LED display of the sterilizing wand of  FIG. 1  in a Continuous mode. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    As illustrated in  FIG. 1A , a sterilizing wand  100  includes a housing  102  with an aperture  104 . The housing  102  may, for instance, be formed of Acrylonitrile Butadiene Styrene (ABS) plastic. Alternatively, the housing  102  may be formed of a plastic suitable for a CBRN (chemical/biological/radiological/nuclear) safety rating. Mounted within the aperture  104  may be a pane of filtering glass  106 . The housing  102  of the sterilizing wand  100  may be considered to have an active portion  132  and a handle portion  134 . 
         [0018]    The sterilizing wand  100  is illustrated in  FIG. 1B  without the pane of filtering glass  106 . As such, a pair of lamps, normally hidden by the pane of filtering glass  106 , are in evidence. In particular, a lamp chamber in the housing  102  may house a C-band Ultra-Violet (UV-C) lamp  116  and an A-band UV (UV-A) black light lamp  118 . The UV-C lamp  116  may be, for instance, an industry standard G6T5 germicidal lamp. Generically, a suitable standard lamp may be described by GXTM, where G indicates that the lamp is germicidal, X is representative of an electrical input power rating in Watts and M is representative of the lamp diameter in ⅛ inch units. Accordingly, a G6T5 lamp has a 6 Watt power rating and a roughly ⅝ inch diameter. As will be clear to a person of ordinary skill in the art, the C-band Ultra-Violet radiation source need not be a GXTM lamp. For instance, UV-C light emitting diodes (LEDs) may be used. 
         [0019]    Material for the pane of filtering glass  106  may be selected to be transparent to UV-C light and to minimize the transmission 185 nm by-product light from the UV-C lamp  116 . The 185 nm by-product light is known to cause the production of ozone. 
         [0020]    In an alternative embodiment, the lamp chamber in the housing  102  houses two UV-C lamps and a UV-A LED  110  is installed at the end of the active portion  132  of the sterilizing wand  100 . 
         [0021]    The sterilizing wand  100  is illustrated in  FIGS. 1A and 1B  to include an ingress  122  to the lamp chamber as well as an egress  124  from the lamp chamber. 
         [0022]    To provide power to the lamps  116 ,  118 , an alternating current (AC) adapter may be attached to the sterilizing wand  100  via a primary power cord  108  with an end that is received by a receptacle on the bottom of the wand (see  FIG. 4 ). It is contemplated that the AC adapter may be rated to provide 12V and 10W for a consumer version of the sterilizing wand  100  and 12V and 20W for an industrial version of the sterilizing wand  100 . The industrial version of the sterilizing wand  100  may, as discussed above, have two UV-C lamps installed in the lamp chamber and a UV-A LED  110  on the exterior of the sterilizing wand  100 . 
         [0023]    An alternative power supply may be provided by a set of batteries (not shown), which may be installed within a battery compartment, say, in the handle portion  134  of the housing  102 . For instance, the sterilizing wand  100  may be powered by eight AA batteries. The batteries may, for instance, be disposable alkaline or rechargeable, such as Lithium ion or Nickel Metal Hydride. A further alternative power supply may be provided by a battery belt, which could hold hot-swappable batteries and be worn by the user. Power may be supplied from the battery belt to the sterilizing wand  100  via a secondary power cord (not shown). 
         [0024]      FIG. 2  illustrates a front elevation view of the sterilizing wand  100  of  FIG. 1 . Evident in  FIG. 2  is a display  210 , which may be used to display information about the operation of the sterilizing wand  100 . Such information may, for instance, include on/off status of each of the lamps. Such information may, for instance, also include battery charge status. Also evident in  FIG. 2  is a control button  212  that may be provided for activating the UV-C lamp  116  and a toggle switch  214  that may be provided for activating the UV-A black light lamp  118 . 
         [0025]      FIG. 3  illustrates a side sectional view of the sterilizing wand  100 . The sectional view of  FIG. 3  provides insight to a cooling and ozone removal mechanism. In particular, an impellor fan  304  is located in the lamp chamber  306 . The Ingress  122  to the lamp chamber  306  is covered by a dust filter  302  while air flows out of the lamp chamber  306  via an ozone catalyst chamber  308  at the egress  124  of the lamp chamber  306 . 
         [0026]    A variety of manufacturers produce ozone catalysts. Ozone catalysts are most commonly based on manganese dioxide and operate by acting as a reaction site for conversion of O3 to O2. The ozone catalyst is simply a medium that air passes through. 
         [0027]    Furthermore, the sectional view of  FIG. 3  provides insight into the manner in which the pane of filtering glass  106  is held in place. In particular, a first hold-down plate  322 A attaches to the housing  102  by a securing means, for example, by a first screw  320 A. Similarly, a second hold-down plate  322 B attaches to the housing  102  by a securing means, for example, by a second screw  320 B. 
         [0028]    The UV-C lamp  116  is illustrated in  FIG. 3  as being supported by a first lamp support  314 A and a second lamp support  314 B. Typical lamp supports are known to be manufactured of hard plastics and ceramics and, as such are generally inflexible. It is recognized that use of the sterilizing wand  100  in an industrial environment may expose the sterilizing wand  100  and, consequently, the UV-C lamp  116  to sudden, jarring motion. Such motion in combination with inflexible lamp supports may lead to a frequent need to replace broken lamps. It is proposed herein, then, to incorporate shock absorbing qualities in the lamp supports  314 A,  314 B. For instance, the lamp supports  314 A,  314 B may be composed of a flexible material or may be connected to the housing  102  using a flexible mount. 
         [0029]    In further evidence in the sectional view of  FIG. 3  is a battery compartment  310  and an electronics-compartment  312 . 
         [0030]    As will be understood by a person of ordinary skill in the art, a controller, in the form of a microprocessor, may be installed in the electronics compartment  312  to perform many functions. 
         [0031]      FIG. 4  illustrates the bottom of the sterilizing wand  100  of  FIG. 1 . In particular, the bottom has a battery door  402 , which may be removed for installation and replacement of the batteries. The bottom also has a first power receptacle  404  for receiving a plug on the end of the primary power cord  108  from the AC adapter and a second power receptacle  406  for receiving a plug on the end of the secondary power cord from the battery belt. 
         [0032]    The connection between the primary power cord  108  from the AC adapter and the first power receptacle  404  may be latched to prevent accidental disconnection of the primary power cord  108 . Similarly, the connection between the secondary power cord and the second power receptacle  406  may be latched to prevent accidental disconnection of the secondary power cord. 
         [0033]    In one embodiment, the sterilizing wand  100  has four different modes of operation: a “Standby” mode; a “Safety” mode; a “Basic” mode; and a “Continuous” mode. 
         [0034]    In operation, a user may first don UV Resistant Safety Glasses. Subsequently, the user may insert the plug on the end of the primary power cord  108  into the receptacle  404  on the end of the sterilizing wand  100 . The user may then plug the AC adapter into an electrical outlet. 
         [0035]    The sterilizing wand  100  enters the Standby mode upon being plugged in to a power supply. To indicate to the user that the sterilizing wand  100  is receiving power, the sterilizing wand  100  may illuminate two LEDs  504  on the display  210  (see  FIG. 5A ). The sterilizing wand  100  may require approximately 60 seconds to warm up. Once warmed up and ready to be used, the sterilizing wand  100  may “beep” to notify the user of such readiness. A speaker (not shown) to emit such a beep may be located in the electronics compartment  312 . 
         [0036]    The user may rapidly press the control button  212  twice to enter Safety mode. Responsive to the control button  212  being pressed twice, the speaker may sound a beep and activate the UV-C lamp  116 . To indicate to the user that the sterilizing wand  100  has entered Safety mode, the sterilizing wand  100  may illuminate three LEDs  506  oh the display  210  (see  FIG. 5B ). In addition, the sterilizing wand  100  may illuminate a further LED  502  on the display  210 . The further LED  502  may be considered a “Run” light  502  and may be used to indicate to the user that the UV-C lamp  116  is activated. While the sterilizing wand  100  is in Safety mode and the UV-C lamp  116  is activated, the speaker may periodically, say, every ten seconds, sound a beep. Characteristic of the Safety mode, the sterilizing wand  100  may de-activate the UV-C lamp  116  after five minutes of operation and return to the Standby mode. 
         [0037]    It is known that, in most cases, only 10 to 20 seconds of direct exposure to UV-C light will kill most household germs. As such, the user may use the periodic beep sounds to gauge the necessary exposure of, an object or area being sanitized. To de-activate the UV-C lamp  116  before the end of the five minutes period of operation, the user may press the control button  212  once. 
         [0038]    The user may rapidly press the control button  212  three times to enter Basic mode. Responsive to the control button  212  being pressed three times, the speaker may sound a beep and activate the UV-C lamp  116 . To indicate to the user that the sterilizing wand  100  has entered Basic mode, the sterilizing wand  100  may illuminate four LEDs  508  on the display  210  (see  FIG. 5C ). In addition, the sterilizing wand  100  may illuminate the Run light  502  on the display  210  to indicate to the user that the UV-C lamp  116  is activated. While the sterilizing wand  100  is in Basic mode, and the UV-C lamp  116  is activated, the speaker may periodically, say, every ten seconds, sound a beep. Characteristic of the Basic mode, the sterilizing wand  100  may de-activate the UV-C lamp  116  after two hours of operation and return to the Standby mode. To de-activate the UV-C lamp  116  before the end of the two hour period of operation, the user may press the control button  212  once. 
         [0039]    The user may rapidly press the control button  212  four times to enter Continuous mode. Responsive to the control button  212  being pressed four times, the speaker may sound a beep and activate the UV-C lamp  116 . To indicate to the user that the sterilizing wand  100  has entered Continuous mode, the sterilizing wand  100  may illuminate five LEDs  510  on the display  210  (see  FIG. 5D ). In addition, the sterilizing wand  100  may illuminate the Run light  502  an the display  210  to indicate to the user that the UV-C lamp  116  is activated. In contrast to the Safety and Basic modes of operation, while the sterilizing wand  100  is in Continuous mode and the UV-C lamp  116  is activated, the speaker may not sound a periodic beep, Characteristic of the Continuous mode, the sterilizing wand  100  may not de-activate the UV-C lamp  116  until the user presses the control button  212  once. 
         [0040]    At any time that the UV-C lamp  116  is activated, the fan  304  may also be activated. The activated fan  304  draws air into the lamp chamber  306  through the dust filter  302  and forces the air past the lamps  116 ,  118  and through the ozone catalyst chamber  308 . It is known that when the UV-C lamp  116  is operating, oxygen (O 2 ) in air nearby to the UV-C lamp  116  will be converted into ozone (O 3 ). The activation of the fan has multiple advantageous effects. The air drawn from outside of the sterilizing wand  100 , at the ingress  122 , can act to cool the UV-C lamp  116  and can act to flush the ozone created by the operation of the UV-C lamp  116  into the ozone catalyst chamber  308 , where the ozone (O 3 ) may be converted to oxygen (O 2 ) before being expelled from the sterilizing wand  100  at the egress  124 . 
         [0041]    The UV output of the UV-C lamp  116  is temperature dependent and diminishes at higher temperatures. It has been found that optimum output is generally in the 40-50° C. range. As such, the controller may monitor the temperature of the lamp chamber  306  and control the fan  304  to attempt to maintain a temperature in the optimum range. 
         [0042]    Furthermore, even though the pane of filtering glass  106  may be selected to minimize the transmission 185 nm by-product light from the UV-C lamp  116 , some 185 nm by-product light will likely be emitted and, as such, ozone will likely be created outside of the sterilizing wand  100 . 
         [0043]    By drawing air into the lamp chamber  306 , some of the ozone surrounding the sterilizing wand will also be drawn into the lamp chamber  306  and forced through the ozone catalyst chamber  308 , where the ozone (O 3 ) may be converted to oxygen (O 2 ) before being expelled from the sterilizing wand  100 . 
         [0044]    For disinfecting an element of a bed, for example, a mattress, a quilt or a pillow, it is recommended that the bed element be vacuumed first. The sterilizing wand  100  may be held approximately eight inches (20 cm) above the surface of the bed element and may be moved sideways over one foot (30 cm) for 20 seconds. The location of the sterilizing wand  100  may then be adjusted so that a further one-foot-long portion of the bed element may be exposed to the radiation from the UV-C lamp  116 . Exposure and position changing may be continued until the entire desired surface area of the bed element has been exposed. The same approach for disinfecting an element of a bed may be used for disinfecting an animal mattresses or enclosure. 
         [0045]    Toothbrushes, razors and other personal hygiene implements may be disinfected through exposure at closed range (a few inches or less) for a minimum of 10 seconds. 
         [0046]    For kitchen utensils, such as knives, utensils and chopping boards, the sterilizing wand  100  may be held at close range for a minimum of 10 seconds. Notably, the sterilizing wand should be used away from water sources. 
         [0047]    For fruit, the sterilizing wand  100  may be held approximately 8 inches (20 cm) above target surfaces for 20 seconds of exposure. Notably, over-exposing fruit may change the taste. 
         [0048]    For general bathroom germs and odors, the sterilizing wand  100  may be held approximately four inches (10 cm) above the surface of the toilet seat and slowly move the sterilizing wand  100  sideways over the entire surface for a total of 20 seconds. Care should be exercised so as not to immerse the sterilizing wand  100  in water. 
         [0049]    To control airborne germs in the bathroom, the sterilizing wand  100  may be hung in the bathroom for one hour while the bathroom is unoccupied. For safety, the bathroom should be locked to prevent children or others from unsuspectingly entering the bathroom while disinfection is taking place. 
         [0050]    To minimize or eliminate musty smells in rooms, the sterilizing wand  100  may be placed in Basic mode and left in the room for two hours, Again, the room should be locked. 
         [0051]    Shoes may be exposed once a week at close range for five minutes to kill germs that cause athlete&#39;s foot. The soles of the shoes may be exposed more frequently. It has been recognized that the soles of shoes are a significant source of bacteria in the home. 
         [0052]    Computer keyboards, doorknobs, telephones, etc. may be exposed at a distance of 8 inches (20 cm) for 10 seconds. 
         [0053]    When in doubt, it has been found that effective disinfection can generally be achieved in 20 seconds at a distance of about 8 inches (20 cm). 
         [0054]    The UV-A black light lamp  118  may be used as both a stain detector and a flashlight. In particular, the UV-A black light lamp  118  may be used to locate sources of pet odor, such as traces of urine, feces and vomit that may be invisible under normal light conditions. 
         [0055]    In operation, it is recommended that the user darken the room in which stain detection is to take place. The UV-A black light lamp  118  may then be activated through use of the toggle switch  214  (see  FIG. 2 ). The user may then hold the sterilization wand  100  above a surface on which stain detection is to take place. The user may recognize contamination as pale spots of glowing yellow. The user may then use the toggle switch  214  to de-activate the UV-A black light lamp  118  and press the control button  212  a number of times to activate the UV-C lamp  116  in a particular-operational mode. 
         [0056]    As should be clear, while use of the UV-C lamp  116  of the sterilization wand  100  may kill the microorganisms that cause an odor associated with a stain that may be found using the UV-A black light lamp  118 , the stain will not be removed. 
         [0057]    Software executed by the microprocessor in the electronics compartment  312  may allow the microprocessor to monitor factors related to battery health, including such factors as current, voltage and battery temperature. Software executed by the microprocessor may allow the microprocessor to control the LEDs of the display  210 . Software executed by the microprocessor may allow the microprocessor to provide an indication of a number of available batteries in a power supply setup wherein the batteries, either internal or external to the sterilizing wand  100 , are hot-swappable. That where the sterilizing wand  100  may switch from receiving-power from a first set of batteries to receiving power from a second set of batteries, while in operation. Software executed by the microprocessor may allow the microprocessor to monitor lamp health, for instance, by monitoring the amount of current drawn by a lamp. Software executed by the microprocessor may also allow the microprocessor to monitor and report on the mode of operation by controlling the LEDs of the display  210 . Software executed by the microprocessor may allow the microprocessor to monitor and report on the source of power, that is, whether the power is being drawn from batteries, from the first power receptacle  404  or from the second power receptacle  406 . 
         [0058]    Advantageously, the sterilizing wand  100  has a lightweight, convenient, hand-held design and eliminates bacteria, viruses, funguses, molds, etc., without harmful chemicals and leaves no chemical residue. Notably, moderate exposure to UV light has been found to be harmless to the materials that are being disinfected. In aspects of the present invention, the display  210  informs the user that the UV-C lamp  116  is activated. 
         [0059]    Further advantageously, as produced by the action of the fan  304 , the air flow past the UV-C lamp  116  provides a cooling effect that allows for the use of a more powerful UV-C lamp than may be used in conventional hand-held UV sterilizers. A lamp of higher UV power output may be seen to kill more germs in the same period of time than a lamp of lower UV power output. Alternatively, a lamp of higher UV power output may be seen to kill a fixed number germs faster than a lamp of lower UV power output. The air flow also allows for use of the ozone catalyst chamber  308  to reduce or remove the ozone before the air is expelled from the lamp chamber  306 . Additionally, the fan  304  acts to bring air into the lamp chamber  306  from around the sterilizing wand  100 . In the event that the use of the sterilizing wand has produced ozone in the air external to the sterilizing wand  100 , the ozone catalyst chamber  308  may also reduce or remove the ozone in the external air. 
         [0060]    Additionally, safety features of the sterilizing wand  100  include the pane of filtering glass  106 , which may contain a broken lamp, and the automatic shutoff of the UV-C lamp  116  in two of the three operational modes. 
         [0061]    Other modifications will be apparent to those skilled in the art and, therefore, the invention is defined in the claims.

Technology Category: 7