Abstract:
UV hard-surface disinfection system that is able to disinfect the hard surfaces in a room, while minimizing missed areas due to shadows by providing multiple UV light towers that can be placed in several areas of a room such that shadowed areas are eliminated and that can be transported by a cart that is low to the ground such that the towers may be loaded and unloaded easily by a single operator. The system is able to be controlled remotely, such that during activation of the system, no operator is present, and to automatically cut power to all towers in the event that a person enters the room.

Description:
RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 14/540,869 filed Nov. 13, 2014 entitled Hard-Surface Disinfection System, which is a continuation of U.S. patent application Ser. No. 14/043,465 filed Oct. 1, 2013 entitled Hard-Surface Disinfection System, which is a continuation of U.S. patent application Ser. No. 12/963,590 filed Dec. 8, 2010 entitled Hard-Surface Disinfection System (now U.S. Pat. No. 8,575,567 issued Nov. 5, 2013), which is the non-provisional of and claims priority to U.S. Provisional Application Ser. No. 61/324,257 filed Apr. 14, 2010, entitled Hard-Surface Disinfection System and to U.S. Provisional Application Ser. No. 61/267,805 filed Dec. 8, 2009, entitled Hard-Surface Disinfection System, the contents of all of which are incorporated herein in their entireties. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to systems for disinfection of hard-surfaces and related methods thereof and, more particularly, to ultraviolet light disinfection of hard-surfaces. 
     BACKGROUND OF THE INVENTION 
     Disinfection of the hard surface environment is a key factor in the constant battle to reduce infections. The emergence of multi-drug resistant organisms (MDROs) throughout the as-built environment poses a significant threat to the health and well-being of people throughout the world. MDROs in the environment contribute to rising health care costs, excessive antibiotic use and premature mortality. 
     Disinfecting hard surfaces, such as those found in patient areas, can be performed by exposing the hard surfaces to UVC light that is harmful to micro-organisms such as bacteria, viruses and fungi. Ultraviolet germicidal irradiation (UVGI) is an evidence-based sterilization method that uses ultraviolet (UV) light at sufficiently short wavelengths to break-down and eradicate these organisms. It is believed that the short wavelength radiation destroys organisms at a micro-organic level. It is also believed that UV light works by destroying the nucleic acids in these organisms, thereby causing a disruption in the organisms&#39; DNA. Once the DNA (or RNA) chain is disrupted, the organisms are unable to cause infection. The primary mechanism of inactivation by UV is the creation of pyrimidine dimers which are bonds formed between adjacent pairs of thymine or cytosine pyrimidines on the same DNA or RNA strand. 
     There are several advantages to utilizing UV light, in addition to the effectiveness described above. UV light requires only electricity, there are no potentially hazardous chemicals and the associated storage challenges presented thereby. UV light leaves no residue, does not require drying time, cannot be spilled, requires little manpower to apply, requires very little skill on the part of the operator, and uses long-lasting bulbs that require very little inventory management. 
     Safely using UV light to disinfect hard surfaces does present some unique problems. First, UV light sources cast shadows. Areas in shadows may not get disinfected. Second, UV light bulbs, like nearly all light bulbs, are relatively fragile and present dangers if broken. Third, UV radiation is harmful to humans, especially in high-intensity applications like those used in disinfecting procedures. 
     As such, there is a need for a UV hard-surface disinfection system that exploits the advantages of UV light, while also addressing the aforementioned problems. 
     SUMMARY OF THE INVENTION 
     One aspect of the present invention provides a UV hard-surface disinfection system that is able to disinfect the hard surfaces in a room, while minimizing missed areas due to shadows. In one embodiment, a system is provided that includes multiple UV light towers. These towers can be placed in several areas of a room such that nearly all shadowed areas are eliminated. 
     Another aspect of the present invention provides a UV light tower design that incorporates a robustly protected light bulb, thus reducing the occurrence of broken bulbs. In one embodiment, the tower comprises a vertically oriented light bulb surrounded by a plurality, preferably three, protective blades running the length thereof. The blades preferably radiate from the bulb and are spaced 120 degrees apart. This design provides significant protection to the bulb, while minimizing interference with the light being emitted from the bulb. 
     In another preferred embodiment, the light bulb is surrounded and protected by a clear, quartz sleeve. In addition to protecting the bulb from accidental breakage, the sleeve induces a convection effect, like a chimney. As the bulb heats, cool air is drawn through vents in the bottom of the sleeve, heated and exhausted through the top of the sleeve. This circulation cools the bulbs, extending their life and protecting users from accidental burns. 
     In order to further protect the bulb, another aspect of the present invention provides a tower that has a relatively wide base and a very low center of gravity. This design is a safety feature that creates stability and reduces the possibility of a tower tipping over while it is being moved. 
     In yet another aspect of the present invention there is provided a UV disinfection system that minimizes UV light exposure to humans during operation. In a preferred embodiment, the system is able to be controlled remotely, such that during activation of the system, no operator is present in the room. 
     In another preferred embodiment, one or all towers are outfitted with safety devices that cut power to all towers in the event that a person enters the room. More preferably, the safety device includes motion-detecting capability, such that the safety shutdown response is automatic. In a preferred embodiment, the motion detection capability incorporates a laser scanner, providing an extremely accurate motion detection capability that is more thorough and less prone to false positives than other motion detection scanners such as infra-red devices. 
     Another aspect of the present invention provides a control cart that is constructed and arranged to transport a plurality of towers. The cart is low to the ground such that the towers may be loaded and unloaded easily by a single operator. Alternatively, the towers may be linked together with the cart to form a chain. This embodiment allows the towers to support themselves continuously, while being transported by pushing or pulling the cart. This embodiment also allows the use of a hand-cart attachment, which provides a solution to moving all of the units from one room to another without requiring that they be reloaded onto the control cart, which may be left in a single location, such as a hallway, in proximity to both rooms. 
     One embodiment provides a cart that includes a control panel that can be used to remotely control various parameters of each of the towers, as well as provide various diagnostic data to the user. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an embodiment of a system of the present invention; 
         FIG. 2  is a perspective view of an embodiment of a system of the present invention; 
         FIG. 3  is a perspective view of an embodiment of a light tower of the present invention; 
         FIG. 4  is a perspective view of an embodiment of a light tower of the present invention in a first configuration; 
         FIG. 5  is a perspective view of the light tower of  FIG. 5  in a second configuration; 
         FIG. 6  is a perspective view of an embodiment of a base of a light tower of the present invention; 
         FIG. 7  is a perspective view of an embodiment of a base of a light tower of the present invention; 
         FIG. 8  is a perspective view of an embodiment of a light tower of the present invention connected to two other light towers and a hand cart of the present invention; 
         FIG. 9  is a bottom perspective view of an embodiment of a light tower of the present invention loaded into a controller cart with two other light towers; 
         FIG. 10  is a partial elevation view showing an embodiment of a tower cap of a light tower of the present invention; and 
         FIG. 11  is a partial elevation view showing an embodiment of a tower cap of a light tower of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Specific embodiments of the invention will now be described with reference to the accompanying drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. The terminology used in the detailed description of the embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, like numbers refer to like elements. 
     Referring now to the figures and first to  FIG. 1 , there is shown an embodiment of a system  10  of the present invention. System  10  generally includes a control station or cart  100  and a plurality of light assemblies or towers  200 , shown as loaded onto the cart  100 . 
     The cart  100  generally includes a carriage  110  supported by a plurality of casters  112 , and defining a cutout  114  shaped to receive and secure the towers  200  for transport. The distal end  116  of the cutout  114  is open such that the towers may be easily loaded onto and off of the cart  100 . The cutout  114  may include a complete floor (not shown) onto which wheels  202  of the towers  200  (see  FIG. 2 ) may be rolled. 
     More preferably, however, the cutout  114  has an open bottom and a supporting ridge that slightly elevates the wheels  202  off the ground. This design provides a secure relationship between the cart  100  and the towers  200 . Many hospitals include ramped areas. Disabling the wheels  202  by elevating the towers  200  prevents the towers from rolling off of the cart  100 . 
     Alternatively, as shown in  FIG. 2 , an embodiment  101  of the cart has a carriage  111  that allows the the towers  200  to remain in contact with the ground, rather than being elevated. The towers in this embodiment are preferably linked together for transport, with at least one tower being linked or otherwise attached to the cart  100 . 
     The cart  100  or  101  may also include a pair of safety arms  120  that extend along the length of the cart  100  or  101  on other side of the towers  200  when the towers  200  are loaded onto the cart  100  or  101 . Aesthetically, the arms may match the cutout  114  of the carriage  110  or  111 . Functionally, the arms  120  provide protection against accidentally impacting the towers against objects or people as the towers  200  are being transported on the cart  100  or  101 . 
     In one embodiment, at a proximal end  122  of the cart  100 , there is a foot jack  126 . The foot jack  126  is usable to elevate the cart  100  enough to raise the wheels  202  off the ground. In this way, the wheels  202  of the towers  200  may be used to roll the towers  200  into the cutout  114 . Once the towers  200  are in place within the cutout  114 , the foot jack  126  is depressed, raising the towers  200  off the ground. When it is desired to deploy the towers  200 , the foot jack  126  is released and the cart  100  lowers the towers  200  such that the wheels  202  are again in contact with the ground. 
     Also at the proximal end  122  of the cart  100  or  101 , there is a handle  130  and a control panel  140 . The control panel  140  may include a display  142  usable to display a variety of parameters relevant to the safe operation of the towers  200 . The parameters include, but are not limited to: ambient room temperature, room dimensions, fluence level, disinfection time, input current and voltage, and maintenance information such as bulb run time. Additionally, the control panel may be used to upload, preferably wirelessly, data to a hospital information system regarding the sanitization of a given room. It is also envisioned that the control panel would have a communications ability that is compatible with the LMS (or similar) system found in many hospitals (smart scanner system to evaluate distance and occupancy) e.g. the LMS can map the room and an algorithm could calculate emitter run times. 
     One embodiment of a light tower  200  is shown in  FIG. 3 . The light tower  200  generally includes a base  220  supported by a plurality of wheels  202 , a tower assembly  250 , and a cap  300 . 
     Another embodiment of a light tower  201  is shown in  FIG. 4 . The light tower  201  includes a base  221  and is supported by a plurality of wheels  202 , a tower assembly  251 , and a cap  301 , but also has a push ring  400  assembly for use in moving the light tower  201  without applying pressure to the light source  270 . The push ring  400  preferably includes a handle  410  and a plurality of telescoping supports  420 . The telescoping supports  420  allow the push ring to be stowed in an active configuration, shown in  FIG. 5 , when the light source  270  is activated. Because the push ring  400  is lowered in the active position, it does not interfere with the light beams emitted by the light source  270 , thereby ensuring no shadows are created by the push ring assembly. 
     Electronics may be utilized to prevent the activation of the light source, and/or emit a warning, if the push ring is in the up position. Alternatively, the telescoping arms  420  may be automatically activated such that they lower themselves prior to activating the light source and raise themselves upon completion. 
     Reference is now made to  FIGS. 6-9 , which show details of embodiments  220  and  221  of the base, respectively. Notably, shared features between the two are indicated by common reference numerals. It is also understood that in these Figures, and throughout the specification, that features may be interchangeable between embodiments. The base  220  or  221  is comprised of a housing  222  or  223  that contains power circuitry for the tower  200  or  201 . Preferably, the housing  222  or  223  is round so that the tower  200  or  201  may be easily docked within the cart  100  or  101  without regard to angular orientation. The housing  222  or  223  may optionally include one or more bumpers  224  (shown associated with housing  222 ) to protect the base  220  or  221  as well as anything the base  220  or  221  may contact. 
     The base  220  or  221  may also include one or more power connections  226 . Providing a plurality of power connections  226  allows one of the towers  200  or  201  (designated herein as the “master” tower) to be connected into a standard outlet. The remaining towers may then be “daisy-chained” to the master such that power to all of the towers  200  or  201  may be controlled by the cart  100  or  101 . This results in a redundant safety relay in the base  220  or  221  of the master to control power to all down-stream units that are connected together. The power connections  226  are shown in the Figures as being female outlets but one skilled in the art will realize that this is merely a convention of convenience and not to be interpreted as limiting. 
     The tower assembly  250  generally includes a base connector assembly  260 , a light source  270 , and, optionally, a plurality of protective blades  280 . The base connector assembly  260  connects the bottom of the tower assembly  250  to the base  220  or  221 . The base connector assembly  260  includes one or more connectors  262 , shown in  FIG. 6  in non-limiting example as hand screws, and in  FIG. 7  in non-limiting example as bolts or machine screws, and a light socket  264 . Preferably, the connectors  262  may be secured and released without the use of tools for ease of bulb replacement and other maintenance. Most importantly, the light socket  264  securely connects the tower assembly  250  to the base  220  and is sturdy enough to withstand lateral forces placed on the tower assembly  250 . 
     The light source  270  may be any appropriately shaped UV light source, capable of emitting sufficient light for purposes of sanitizing a room. Non-limiting examples include a low pressure amalgam light source, preferably with a solarization-reducing coating. Foreseeably, an LED UV light source would draw less power and may be optimally suited to battery-powered towers  200 . The light source  270  preferably includes a variable output transformer  271  (see  FIG. 7 ). The variable output transformer  271  controls the output power of the light source  270 . 
     As shown in  FIG. 7 , the base  220  or  221  may also include a fluency sensor  273 . This sensor  273  monitors the power output of the light source  270  to ensure that it maintains an output over a threshold, which may be either an absolute threshold, or a range within a set power output. If the light source  270  has a power output that drops below this threshold, the sensor  273  sends a signal to the control panel  140  indicating a lower power output status of a given tower  200  or  201 . This may indicate a bad bulb or other problem that may result in compromised disinfection if the condition is not repaired. 
     Also shown in  FIG. 7  is a lockout disconnect  275 . This is a mechanical power switch that accommodates a padlock that, when in place, prevents the power switch from being turned to an on position. This ensures a tower  200  or  201  may not be inadvertently activated. 
     Shown also in  FIG. 7  is a mechanical linkage  277  that allows the base  221  to be mated with another base  221 . The linkage  277  is a female linkage. A corresponding male linkage  279  is on the other side of the base  201 . As discussed above, these linkages  277  and  279  provide a convenient means for transporting the towers  200  or  201  from room to room.  FIG. 8  shows three towers  201  connected together with linkages  277  and  279  and a handle  281  configured to mate with a male connector  279  or a female connector  277 . 
       FIG. 9  shows an embodiment of a bottom of base  220  or  221  that includes one or more floor lamps  283 . The floor lamps  283  provide disinfecting light under the bases  220  or  221  to ensure there are no shadows created by the units themselves, and also that contaminants are not dragged from room to room by the towers  200  or  201 . 
     Though the light source  270  is shown as being vertically-oriented, it is envisioned that the light source  270  may be angled or even oscillating to further reduce shadows. 
     The selection of a lamp is a significant factor in determining the footprint of the system  10 . The physical layout of a patient care area will provide obstacles to the UVC emissions. These obstacles will produce shadows on surfaces and therefore reduce the effectiveness of the system in certain areas of the patient care area. The system  10  footprint is flexible so that it can be deployed in such a way to overcome these shadows. Satellite rooms such as the washroom attached to a patient care area will also pose a challenge to the system as these areas have a high probability of containing micro-organisms that could lead to a Hospital Acquired Infection. The UVC reflective properties of materials are not the same as that of visible light. The systems will be deployed in existing patient care areas so selection of materials with a high degree of UVC reflectivity is not an option. The system&#39;s repeatability will suffer if system depends on reflected UVC light to overcome shadows from obstacles in the room. 
     The light source  270  is preferably surrounded by a protective sleeve  272 . The protective sleeve may be constructed of any suitable clear material capable and very efficient at passing UVC as well as protecting the bulb against impact without significantly interfering with the light being emitted. 
     In a preferred embodiment the protective sleeve  272  comprises a quartz sleeve, synthetic quartz sleeve or similar synthetic material to provide stability to the bulb as to not restrict light and/or create shadow. It has been noted that using a quartz sleeve  272  creates a protective temperature barrier to reduce the severity and/or occurance of skin burns. Because the sleeve  272  is significantly cooler than the bulb surface, using a sleeve  272  may also reduce odors due to dust and other particulates landing on the bulb and burning. 
     It is known that the sleeve  272  creates a chimney effect in that heat coming off the light source  270  rises forcing cool convection air to be drawn upward through the sleeve  272  from the bottom. It may be beneficial to provide a forced cooling system, in which a fan could be provided in-line with the top or bottom of the sleeve  272 . 
     In most applications, the quartz sleeves  272  provide sufficient protection against accidental breakage. However, some applications may warrant a more robust design. As such, one embodiment of the present invention provides a light source  270  that further includes a plurality, preferably three, protective blades  280  radiating from the light source  270  (e.g.  FIG. 3 ) or guidewires  281  (e.g.  FIG. 5 ). The blades or guidewires  280  or  281  may be any acceptably light, yet strong material, such as aluminum, plexiglass, or the like. A clear material may reduce shadows but, due to the thin construction and radiating orientation of the blades  280 , they have very little effect on the light emission capabilities of the light source  270 . Shown are three blades  280 , spaced 120 degrees apart, and including a plurality of circular cutouts used to increase stiffness and reduce weight, or four guidewires  281  space 90 degrees apart. 
     Referring now to  FIGS. 10 and 11 , there are shown two embodiments  300  and  301  of the cap assembly at the top of the tower assembly  250 . The cap assembly  300  or  301  is used to secure the various components of the tower assembly  250  together. The cap assembly  300  or  301  also preferably houses a safety sensor  302  or  303 , preferably a motion detector that senses if a person has entered a room and disables the tower. This motion detector could be an infrared motion detector, such as those found in many security systems, or it could be a dual motion detector, a door curtain or the like. Preferably, the safety sensor  302  or  303  includes a motion detector that uses lasers that scan the surrounding area. A preferred embodiment of the cap assembly  301 , shown in  FIG. 11 , utilizes a safety sensor  303  that overhangs the rest of the cap assembly  301  such that the sensor can “see” virtually straight down, giving the sensor nearly 180 degrees of vertical coverage, as well as 360 degrees of coverage in a horizontal plane. As such, safety sensor  303  has nearly complete spherical coverage with exception of the area directly under the base, which would not encounter motion. 
     In a preferred embodiment, the cap assembly  300  or  301 , or the base assembly  220  or  221 ,also includes a communications module  304 . The communications module  304  communicates via any acceptable medium such as radio, wifi, microwaves, Bluetooth®, etc., with the cart  100  or  101 , and optionally the other towers  200  or  201 . Thus, if one sensor  302  or  303  senses movement, a signal could be sent to the other towers  200  or  201  to shut down. Alternatively, a signal could be sent to the cart  100  or  101 , which would in turn shut the remaining towers  200  or  201  down. 
     The sensor  302  or  303  may also be used to detect and monitor the fluence level of the UV emissions (unless the base includes a fluence sensor such as the fluence sensor  273  on base  221 ) to confirm that the tower  200  or  201  is operating at a desired level. These sensors can be used in conjunction with an amplifier to transmit the data to a control device that will integrate the irradiance level to obtain the fluence level received at the sensor. Single point photosensors are sensitive to the angle of light incidence. 
     Preferably, the tower  200  or  201  also includes a speaker (not shown) in either the communications module  304  or the base  220  or  221  that creates an audible warning before the light source  270  is energized. It is also envisioned that the communications module  304 , may be used to electronically measure the room to determine the appropriate output necessary by the tower  200  to adequately sanitize the space. This feature ensures that energy is not wasted and bulb life and safety are maximized. 
     The cap assembly  301  shown in  FIG. 11  also includes one or more vents  305  in fluid communication with an interior of the protective sleeve  272  to allow air heated by the lamp  270  to escape. 
     Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention. For example, the system of the present invention might be well-suited for applications outside of healthcare. Non-limiting examples include locker rooms and other athletic facilities, daycares, prisons etc. Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof.