WO2015116876A1 - Ultraviolet disinfection device and method - Google Patents

Abstract

An ultraviolet disinfection system comprising a mobile ultraviolet disinfection device comprising a UVC lamp assembly, a mobile base, and a control system; and a look-up table containing information on a location to be disinfected; wherein the information in the look-up table may be used to operate the UVC lamp assembly via the control system to achieve at least a targeted UVC irradiance, corresponding to a predicted UVC disinfection dose, on targeted surfaces in the location to be disinfected.

Description

ULTRAVIOLET DISINFECTION DEVICE AND METHOD

CLAIM OF PRIORITY

[0001] This patent document claims the benefit of priority of Pringle, U.S. Provisional Patent Application Serial Number 61/933,568 entitled "MOBILE ULTRAVIOLET DISINFECTION DEVICE", filed on January 30, 2014, and of Pringle, U.S. Provisional Patent Application Serial Number 61/933,539 entitled "PREDICTION AND OPTIMIZATION OF ULTRAVIOLET LIGHT IN AN ENCLOSED SPACE", filed on January 30, 2014. The entire contents of both provisional applications are hereby incorporated by reference.

TECHNICAL FIELD

[0002] The present invention relates generally to the disinfection of an enclosed space using a mobile device emitting ultraviolet light, including ultraviolet-C (UVC), more particularly, a mobile UVC device utilizing measurement and simulation.

BACKGROUND

[0003] Mobile UVC disinfection devices can be used to disinfect enclosed spaces such as hospital rooms, locker rooms, food processing facilities, and other locations where surface disinfection is desired. [0004] U.S. Patent 8,841,634 teaches an Ultraviolet Germicidal Irradiation (UVGI) disinfection process utilizing a ring of cylinder shaped housings containing UVC lamps. U.S. Patent 8,841,634 also teaches a configurable UVC emission field by increasing or decreasing individual lamps based on information from corresponding UVC radiometric sensors.

[0005] U.S. Patents 6,656,424 and 6,911,177 teach a plurality of vertical UVC lamps in a ring with a plurality of UVC radiometric sensors on the top of the lamp assembly. The device continues to power all lamps until all of the sensors have received a desired amount of only reflected UVC light.

[0006] U.S. Patent 8,816,301 teaches a ring of slanted lamps with and without reflectors, and a mechanism to move lamps and reflectors in order to focus UVC within a vertical band. [0007] U.S. Patent 8,105,532 teaches a UVC light sterilizing wand utilizing a distance sensor to calculate accumulated direct UVC light irradiance, including an indicator to the user when said accumulated irradiance, or dosage of UVC light, has been achieved.

[0008] U.S. Patent 7,459,694 teaches non-vertical (slanted) ring of UVC lamps in a cone configuration.

SUMMARY OF THE INVENTION

[0009] In accordance with the invention, a device and method to UVC disinfect an interior room comprising matching measureable parameters of the room to simulations of sufficiently similar rooms, and adjusting the device until desired targeted surfaces in the room have achieved a predicted UVC disinfecting dose.

[0010] The present inventors have recognized, among other things, that a problem to be solved includes achieving a desired accumulated UVC irradiance, corresponding to a predicted UVC surfaces disinfection dose, on target surfaces in interior rooms, where UVC radiometric sensors are not present on all target surfaces, and where a portion of said surfaces are not in direct "line of sight" light of the UVC device. Common previous approaches typically rely on direct light calculations for determination of predicted UVC dosage, which does not account for the UVC irradiance accumulating on indirect surfaces. Sensor-based approaches have been used to determine distance for direct light UVC irradiance calculations. In this approach, the distance information is used to determine the length of time that the UVC lamps need to remain powered on and illuminating the directly lit surfaces at the measured distance, or to adjust the amount of UVC intensity from the lamps that illuminate the specific area that was measured for a given illumination time. Other approaches measure the accumulated UVC irradiance, and therefore a predicted UVC disinfection dosage, on UVC radiometric sensors on the device or located within the enclosed space. In this approach, the UVC radiometric sensors measure UVC irradiance incident on the sensor's photodiode and the UVC lamps maintain illumination until all sensors have accumulated a UVC irradiance corresponding to a predicted UVC disinfection dosage. Neither the first sensor-based approach, incorporating distance, nor the second sensor-based approach, incorporating UVC radiometric sensors, determines the UVC irradiance, or the predicted UVC disinfection dosage, on indirectly lit surfaces where sensors are not present. Furthermore, the first sensor-based approach, measuring distance, does not account for reduced UVC irradiance caused by objects just out of the sensing range of the distance sensor that occlude at least part of the emissive area of the UVC lamps, such as a bed in a hospital room which can block some of the UVC light from the surfaces where the distance sensor measured. In this instance where objects occlude a portion of the UVC lamps, a calculation of UVC irradiance based on distance would not properly reduce said calculated irradiance by the amount of total UVC blocked by the occlusion, thus overestimated the UVC irradiance at the surface measured by the distance sensor. Simply combining the teachings of the first and second sensor- based approaches results in a dual sensor modality, incorporating distance for direct light and UVC irradiance for sensor locations, but this combined approach still does not solve the problem of achieving a desired accumulated UVC irradiance, corresponding to a predicted UVC disinfection dose, on target surfaces in interior rooms, where UVC radiometric sensors are not present on all target surfaces, and where a portion of the said surfaces are not in direct "line of sight" light of the UVC device, or where some of the said surfaces in direct light of the UVC device have a portion of said light occluded by objects. Approaches to UVC disinfection of water can incorporate UVC radiometric sensors but these approaches uses measurements and calculations for fixed mount lamps inside unchanging metal reactors of simple form, typically without occlusions. This approach does not solve the problem of achieving a desired

accumulated UVC irradiance, corresponding to a predicted UVC surfaces disinfection dose, on target surfaces in interior rooms because it cannot account for the complex objects which can occlude, reflect, refract, scatter or absorb UVC light in interior rooms. In an example, the present subject matter can provide a solution to this problem, such as by providing a mobile UVC device which measures and calculates room dimensions and the level of UVC light coming from the device and reflecting from the surfaces of the room, and which uses information from computer simulations of interior rooms, with dimensions and occluding objects consistent with the interior room under UVC illumination, to adjust controllable functions in order to achieve a desired accumulated UVC irradiance, corresponding to a predicted UVC surface disinfection dose, on any target surface in an interior room.

[0011] The inventors have determined, amongst other things, that a problem to be solved includes achieving a desired accumulated UVC irradiance, corresponding to a predicted UVC surface disinfection dose, on target surfaces in interior rooms, where UVC radiometric sensors are not present on all target surfaces, and where a portion of said surfaces are not in direct "line of sight" light of a mobile UVC device or devices, and where said interior rooms can be of varying dimensions and/or may have varying levels of UVC reflectivity on surfaces and/or varying objects in the rooms in varying locations. This problem can be further complicated by the fact that the UVC device or devices may be placed in multiple locations in each interior room, or that it may be unpredictable as to which room a UVC device needs to disinfect and in what order. Common previous approaches to UVC disinfection of interior rooms using mobile UVC devices do not solve this problem, nor do they teach that this is a problem to solve. Mobile UVC devices rely on either direct light irradiance calculations, whether sensor-based on non- sensor-based, or measurement of the accumulated UVC irradiance using UVC sensors, whether radiometric of photochemical sensors. These approaches do not determine the UVC irradiance, or the predicted UVC disinfection dosage, on directly lit surfaces partially occluded from the UVC light or on indirectly lit surfaces where sensors are not present. Combinations of these approaches do not provide a solution either. In an example, the present subject matter can provide a solution to this problem, such as by providing a UVC device, a means of measuring and calculating room dimensions, device locations, and the level of UVC light coming from the device and reflecting from the surfaces of the room, and using information from computer simulations of similar parameters to what was measured to adjust the device's controllable functions in order to achieve a desired accumulated UVC irradiance, corresponding to a predicted UVC surface disinfection dose, on any target surface in an interior room.

BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 shows an embodiment with one distance sensor and one UVC light sensor.

[0013] Figure 2 shows another embodiment with multiple distance sensors and multiple UVC sensors.

DETAILED DESCRIPTION

[0014] References will now be made in detail to certain claims of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the enumerated claims, it will be understood that they are not intended to limit those claims. On the contrary, the invention is intended to cover all alternatives, modifications, and equivalents, which can be included within the scope of the invention as defined by the claims.

[0015] References in the specification to "one embodiment", "an embodiment", "an example", "another embodiment", "a further embodiment", "another further embodiment," and the like, indicate that the embodiment described can include a particular feature, structure, or

characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one of ordinary skill in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0016] In this document, the terms "a," "an," or "the" are used to include one or more than one unless the context clearly dictates otherwise. The term "or" is used to refer to a nonexclusive "or" unless otherwise indicated. In addition, it is to be understood that the phraseology or terminology employed herein, and not otherwise defined, is for the purpose of description only and not of limitation. Any use of section headings is intended to aid reading of the document and is not to be interpreted as limiting; information that is relevant to a section heading may occur within or outside of that particular section. Furthermore, all publications, patents, and patent documents referred to in this document are incorporated by reference herein in their entirety, as though individually incorporated by reference. In the event of inconsistent usages between this document and those documents so incorporated by reference, the usage in the incorporated reference should be considered supplementary to that of this document; for irreconcilable inconsistencies, the usage in this document controls.

[0017] The term "look-up table" as used herein can include a tabular listing of data or it can mean a general logic or algorithm to compare one set of parameters to another to find the closest match, or it can mean any process within a functional method or software program or manual method to find data which matches, substantially matches, or is the closest match of a group, or which matches within set tolerance limits, of a set of criteria or other values.

[0018] The term "interior room" as used herein can include hospital patient, operating, or exam rooms, or hotel rooms, or cruise ship rooms, or rooms inside houses or apartments, or school rooms, or rooms within offices building, or interior spaces within a factory, or interior spaces in public buildings, or any space containing complex surfaces and objects.

[0019] The term "substantially" as used herein refers to a majority of, or mostly, as in at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, 99.99%, or at least about 99.999%) or more. [0020] The term "multiple" refers to two or more (e.g., 2, 3, 4, 5, 6, etc.) [0021] The term "ultraviolet light" refers to electromagnetic radiation with a wavelength shorter than human- visible light, such as about 10 nm to about 400 nm.

[0022] The term "UVC" (e.g., ultraviolet C, short-wave ultraviolet, FAR-UV, deep UV) refers to the band of UV light between about 100 nm and about 300 nm. Further, a subset of UVC includes, UV light lying between the wavelengths of about 200 and about 300 nm, commonly referred to as the "germicidal region" because UV light in this region can inactivate

microorganisms including, but not limited to, bacteria, protozoa, viruses, molds, yeasts, fungi, nematode eggs, or algae. An especially destructive wavelength of UV light is about 260 nm. Germicidal UV lamps typically emit light with a wavelength that is substantially close to 260 nm for its destructive purposes, such as around typically around 254 nm.

[0023] The term "absorbing" refers to the process by which a photon is prevented from transmitting through, refracting, or reflecting from a material.

[0024] The term "human-visible" refers to optical properties of an object or process that occurs within the range of human vision, typically from about 400 to about 700 nanometers in wavelength.

[0025] The term "transparent" refers to a photon traveling through a material without being absorbed.

[0026] The term "light" refers to any form of electromagnetic radiation.

[0027] The term "specular reflection" refers to mirror-like reflection of light from a surface, in which light from a single incoming direction is reflected into a single outgoing direction.

[0028] The term "light scattering", "diffusively reflect", or "diffuse reflection" refers to reflection of light from a surface or sub-surface such that an incident ray is reflected or scattered at unpredictable angles.

[0029] The term "location" may refer to a specific place targeted for UVC disinfection, such as a hospital room, an office, or a similar volume of space, or "location" may be used to refer to a geographic location relative to a frame of reference. For example, the phrase "location to be disinfected" refers to a volume of space such as a hospital room, and "the location of the device" refers to the device's specific geographic placement within a frame of reference, such as its placement inside a hospital room. [0030] Figure 1 shows an embodiment of the invention comprising a mobile UVC device with a UVC lamp assembly 10, mounted on a mobile base 20, with a distance measuring sensor 30, a UVC light sensor 40, a sensor module assembly 50 and a top base 60. In this embodiment the sensor module 50 is attached to the top base 60 via a pivoting assembly allowing the sensor module 50 to rotate around the top base 60. During the rotation of the sensor module 50 the room is measured at multiple points by the distance measuring sensor 30, enabling a

microprocessor within the device to calculate room dimensions and the location of the device in the room. The UVC light sensor 40, in this embodiment, is configured to aggregate the UVC light incident upon the sensor such that sensor's field of view is 360 degrees around the horizontal, and optionally includes the ceiling, and optionally includes direct exposure to the lamps. The output of the UVC light sensor 40 is directed to the microprocessor within the device to determine an aggregate level of UVC light coming from the device and from the surfaces in the room. The program running on the microprocessor compares the calculated room dimensions, device location, and aggregate UVC light, against a look-up table of simulations of rooms of varying dimensions, UVC device locations, number of UVC devices, objects in the rooms, orientations and location of objects in the room, and levels of aggregate UVC light intensity coming from the device and reflected from room surfaces, to find the best match. The program compares the user input commanding such things as the level of predicted UVC disinfection desired and optionally for how many surfaces of the room are desired to reach a predicted UVC dose, against the stored results of the simulation showing multiple surfaces and their level of UVC irradiance for each surface for those simulation conditions. The computer adjusts controllable parameters on the device, such as the time duration that the UVC lamps are powered on or the intensity of the lamps until the desired amount, number, or percent of surfaces, or specific target surfaces, in the simulation have achieved the desired predicted UVC disinfection.

[0031] Figure 2 shows an embodiment of the invention comprising a mobile UVC device with a UVC lamp assembly 10, mounted on a mobile base 20, with multiple distance measuring sensors 30, multiple UVC light sensors 40, a sensor module assembly 50, a top base 60, and optional distance or UVC light sensors on the mobile base 70. In this embodiment the sensor module 50 is attached to the top base 60 via a pivoting assembly allowing the sensor module 50 to rotate around the top base 60. Because there are multiple distance measuring sensors 30, the sensor module 50 need only rotate such that all 360 degrees on the horizontal has received a distance measurement. In an embodiment with 2 distance measuring sensors 30 as shown in Figure 2, the sensor module 50 would rotate 180 degrees. In another embodiment with four equally spaced distance measuring sensors 30 the sensor module 50 would only need to rotate 90 degrees. In another embodiment the number of distance measurement sensor can be high enough, as an example 4,5,6,7, 8,9,10 or more distance measuring sensors, that the sensor module 50 need not rotate and the sensor module 50 and the top base 60 need not have a swivel mechanism nor be separate assemblies. In figure 2 the UVC light sensors 40 are shown mounted to the top base 60 to illustrate an embodiment where the UVC light sensors may be selected with a sufficient wide field of view such that it is not necessary to mount them on the rotating sensor module 50.

Optionally sensors 70, either distance measuring or UVC light sensing, can be mounted on the mobile base 20 or anywhere suitable on the device. Distance measuring sensors 30 can also be mounted vertically for applications where ceiling height may vary.

Mobile Base

[0032] The mobile base 20 can contain a means to maneuver the UVC device such as wheels or tracks or other means. The mobile base 20 can be sufficiently wide and heavy to reduce the danger of tipping the UVC device. The mobile base 20 can contain the lamp drivers and other circuitry or modules such as safety interlocks, microprocessors, wireless communication, breakers, power supplies, and other things necessary for function and safety.

[0033] In another embodiment the mobile base 20 of the UVC device could be enabled to self- propel the UVC device. In this embodiment the UVC lamps could remain powered as the device moves about the room, increasing UVC disinfection while reducing the time needed to disinfect. In a further embodiment the UVC device can move itself from location to location, as well as from room to room, including, optionally, moving itself to charging stations. In a further embodiment, the UVC device can be an aerial drone.

[0034] It should be apparent that any configuration or combinations of bases or modules, or the lack of bases or modules, is possible within the definition of the invention.

Lamp Assembly

[0035] The lamp assembly 10 can be comprised of, as an example, of a ring of low pressure "amalgam" high output mercury tube lamps. The lamp assembly can be comprised of a support form or reflector assembly mounted to or adjacent the lamps. Other sources of UVC lighting, such as LEDs, flash tubes, or any sources of UVC can be implemented within the scope of the invention. Any number of UVC lamps, or any number or type of distance measuring or UVC light sensing, can be employed in various embodiments of the invention. Any number of combinations, or locations, or types of UVC emission sources can be incorporated and still fit the definition of the invention. [0036] Changes to UVC light intensity, changes to the UVC emissive pattern using configurable reflectors or lamp intensity, movement of the device during disinfection, movement of lamps or reflectors during disinfection or any other relevant configuration that could be changed before or during the disinfection could be incorporated into the simulation and added to the look-up table.

Measurements and Sensors [0037] The distance measuring sensor 30 may be any appropriate technology for determining the distance to and/or the three-dimensional (3D) structure of an object, including but not limited to laser rangefmders, ultrasonic sensors, RADAR, LIDAR, time of flight or phase shift of light, 3D scanning systems, or any sensor or sensor system capable of measure distance or determining the 3D structure of distant objects. In one example the distance sensor 30 can consist of a time of flight laser rangefmder commonly used in robotics, shooting sports, and remote drones. In another example, the distance sensor 30 can consist of a 3D scanning sensor commonly used to scan detailed dimensions and forms of objects for 3D modeling. In a further embodiment, the detailed distance information, such as from a 3D scanner, can be used to create a detailed 3D model of the room, optionally including the UVC light data from the UVC light sensor 40, to more accurately find a match to the corresponding simulation data, or, in a another further embodiment, the 3D scanning distance sensors 30 could be used to create a detailed 3D model of the room to run a new simulation either on the microprocessor or microprocessors within the device or on an external computer via a data connection, such as a Wi-Fi connection to a cloud computer, and, in this embodiment, the new simulation's output is used to provide a new match for the look-up table, thus increasing the flexibility of the device and accuracy of the outcome. In these further embodiments the 3D scanners can be used to recognize objects within the room, such as chairs and hospitals beds, and subsequently incorporate these objects as clean 3D models free from scanner artifacts. With advancing technology, it should be obvious that as 3D scanning and object recognition improves these advances could readily be incorporated into this invention, allowing ever increasing levels of matching accuracy between the device, locations and objects of the real room to the simulation of the same. [0038] The UVC light sensor 40 may be a simple photodiode with normal cosign law sensitivity to its surface. In another embodiment the UVC light sensor 40 is a vertically-oriented photodiode assembly such that incident UVC light strikes an upside down cone diffuser and is directed into the photodiode, enabling 360 degree sensing. In another embodiment, the diffuser is a quartz tube. In another embodiment, the UVC light sensor 40 consists of multiple photodiodes of varying orientation within a sensor assembly. In another embodiment, a quartz optic fiber can transport light from the lamp assembly 10 to a UVC light sensor 40 to enable measurement of UVC light output from the device and optionally to verify that one, some, or all of the lamps are properly lit. In another embodiment, UVC imaging sensors can be used to determine the UVC reflective characteristics of the surfaces in the room. In a further embodiment, UVC imaging can be combined with 3D scanning to produce a 3D model with UVC reflective characteristics built into the model to produce more accurate UVC irradiance predictions for the modeled surfaces corresponding the surfaces in the match of the look-up table. [0039] Any number of combinations, or locations, or types of sensors can be incorporated and still fit the definition of the invention.

[0040] Measurements of distance and room dimensions, and measurement of UVC reflectivity of surfaces, can be performed by many means. Measurements can be performed by a user or operator or other person prior to placement of the UVC device in the room. Measurement of UVC reflectivity can be performed indirectly such as from information from the manufacturers of the wall or ceiling coatings, or from reference materials. The measurement data can be entered into the UVC device microprocessor via a user interface, or the measurement data can be used to find a simulation match in a written document or software application on a computer or handheld device that serves the function of the look-up table. Look-up table

[0041] In another embodiment, the look-up table is at least partially derived from detailed distance or radiometric sensor measurements of room configurations. It should be apparent that computer simulation is just one means to derive the data needed for the look-up table. While computer simulations generally have benefits over extensive manual measurements or at least partially manual predictive calculations, there can be special applications where radiometrics, manual distance measurements, or manual calculation can derive date for the look-up table. [0042] In another embodiment, the UVC light sensor 40 is not used or is not present. In this embodiment the UVC reflectivity of the surfaces of the room are sufficiently known such that the look-up table does not include UVC light sensor parameters, or is sufficiently truncated to already have a set amount of UVC light sensor measurement pre-selected in the look-up table. An example of this embodiment can be where the user input to the device indicates a certain level of UVC reflection in the room to be disinfected. In this embodiment, the means of determining the level of UVC that will reflect or scatter around the room is already sufficiently determined such that the device or the user does not need to measure it. In another example of this embodiment, sufficient extra power or time can be added to the disinfection program such that the extra time or UVC light intensity is sufficient for the lowest possible level of UVC reflectivity in a room to be disinfected.

[0043] In another embodiment, the distance measuring sensor 30 is not used or is not present. In this embodiment, the room dimensions and optionally the location of the UVC device in the room is sufficiently known such that the look-up table does not include distance measuring sensor parameters, or is sufficiently truncated to already have the room dimensions or device locations pre-selected in the look-up table. An example of this embodiment can be where the user input to the device indicates certain dimensions of the room and, optionally, the location, or locations, of the device, or devices, in the room. In this embodiment, the dimensions and locations are sufficiently determined such that the device does not need to measure or calculate it. In another example of this embodiment, sufficient extra power or time can be added to the disinfection program such that the extra time or UVC light intensity is sufficient for the largest probable room dimension or the least advantageous device location or combinations thereof.

[0044] In another embodiment, the user selects from a menu of room configurations, such as bed locations or chair locations that could be configured with a room of the measured dimensions. [0045] In another embodiment, the measuring of the room dimensions, the location of the device, and the UVC light reflectivity of the surfaces of the room are predetermined. In this embodiment, the user can select the match on the look-up table manually using an interface, or the user can manually adjust the UVC device to change the output of one or more UVC lamps, or to position the device in particular location in the room, or to adjust the amount of time that the UVC lamps will remain powered on based on information at least partially provided by simulation of the room. [0046] The simulations involve more than simple direct line of sight light calculations. The inventors have determined that common simulations methods of UVC reactors for water disinfection, such as computational fluid dynamics (CFD), are not suitable for complex surfaces in interior rooms. In a preferred embodiment the simulations follow the teaching of Pringle, U.S. Provisional Patent Applications Serial Number 61/933,539 entitled "PREDICTION AND

OPTIMIZATION OF ULTRAVIOLET LIGHT IN AN ENCLOSED SPACE".

[0047] The information derived from the simulations can take many forms. The information can be, as an example, a table or listing of data which contains device run times, indicating how long the UVC lights should stay powered on, corresponding to particular room dimensions, or a range of room dimensions, or device locations, or UVC reflectivity of the wall coatings.

[0048] The information within the look-up table at least partially derived from simulation could take the form, as an example, of written guidelines, either printed or in electronic form that a user consults when operating the UVC device. In this example, the user serves to connect the information derived at least partially from simulations to the operation of the device. An electronic form can include a menu system on a computer which can control or send commands to the UVC device.

[0049] In a further embodiment of this example, the UVC device need not contain a

microprocessor, or sensor module, sensors, or any features of the example drawings, except a UVC light source and a means to operate the UVC lights. In this further embodiment, the room dimensions, the location of the device in the room, the objects in the room, the UVC reflectivity of the room is sufficiently known and the information at least partially derived from simulation is sufficiently matched to the details of the room that the user can control the UVC lights, in accordance to the information and the teachings of the invention, to achieve at least a targeted UVC irradiance, corresponding to a predicted UVC disinfection dose, on targeted surfaces in the room, including surfaces not in un-occluded direct light and not on surfaces containing UVC light sensors or other UVC intensity indicators, such as photochemical sensors.

[0050] The simulations of various room dimensions, device locations, multiple device locations and/or multiple devices within the same disinfection cycle, UVC reflectivity variations on room surfaces, types, locations, and orientations of objects in the room, and other aspects of the simulations, can be sorted into groups and ranges. This grouping can take the form of bands of rooms of similar dimensions, or the dimensions could be transformed and grouped into square footage or cubic footages. Device locations within zones or regions in the rooms can be grouped. Logical orientation, locations, types and other aspects of objects within the room, for example hospital patient beds, could be grouped by one or more of these aspects. These groupings can serve to narrow the choices of the look-up table in order to facilitate faster or easier match. Similarly the measurements of the room could be grouped or banded into narrower, or more generalized groups, to facilitate faster or easier matching.

[0051] Many applications utilizing the invention can involve interior rooms of sufficient predictability that room objects such as hospital bed, chairs, cabinets, sinks, bathrooms, doors, and other common objects can be simulated in a rational and achievable number of permutations.

[0052] While prior approaches to UVC disinfection only achieve a predicted UVC disinfection dose on direct light surfaces or on exact locations of UVC light sensors or UVC light sensing photochemical indicators, the present invention addresses the problem, among other things, of achieving a predicted UVC disinfection on any surface in the room. If a user or operator of the UVC device desires to achieve a targeted UVC irradiance, corresponding to a predicted UVC disinfection, on, as just one example, a particular lever on a hospital bed that operates the bed rail adjustment, or, as another example, a particular surface on the doorknob to a bathroom, or any combination of targeted surfaces or combination of similar or different predicted UVC disinfection dosage per target, the present invention teaches how this can be achieved. In these two examples of target surfaces, placing radiometric or photochemical sensors on these surfaces is difficult or impossible and can fail to be predictive, because the form factor of the sensor can fail to match the form factor of the targeted surfaces, moreover many users desire to achieve predicted UVC disinfection on many, sometimes dozens or even hundreds of target surfaces, making placement of sensors on each surface burdensome, expensive, or impossible.

Simulations of hundreds of target surfaces within a room, even if every surface has a different targeted predictive UVC disinfection dose, is achievable using the teachings of this invention. Simulations of sufficiently similar models of those surfaces with sufficiently similar models of the objects containing those surfaces within overall room model dimensions and UVC

reflectivity sufficiently similar to the real room achieve sufficiently accurate predictions with the desired tolerance limits of accuracy. Many users or operators of UVC devices have accuracy tolerances such that, or sufficient UVC light power-on time (disinfection time) or power level can be increased such that, generalized simulations within groupings that do not contain every object or every detail of the room to be disinfected will be sufficient. Many interior rooms are sufficiently predictable in their size and objects and other aspects such that sufficient matching can be accomplished with more generalized simulations within generalized groupings of a narrow set of likely variations. As an example of this relative predictability, hospital patient rooms, as just one example, tend to be rectangular, tend to have the patient bed in one of two orientations, tend to have the patient bed generally central to the room on the sides of the bed and generally near a wall on the head of the bed, tend to have a bathroom, a sink, a cabinet, and a visitor's chair, all of which are generally within predictable locations within a limited number of configurations. While the permutations of possible configurations can be a large number, simulations can be run on large numbers of permutations and the results analyzed to identify what variations are most important and what variations can be grouped and generalized. An example of how this generalizing or grouping of the many permutations can be implemented, is by adding some extra UVC light power on time (disinfection time) to account for outliers in the variations with a defined accuracy or desired predictive confidence. Groupings can, as just one example, take the form of rectangular rooms with square footage bands, such as 50-100 square feet, 100-150 square feet, 150-200 square feet and so on. In another example of groupings, bands of room dimensions could take to form such 8 by 10 feet, 10 by 10 feet, 12 by 10 feet, 14 by 10 feet, 12 by 12 feet, 14 by 12 feet, 14 by 14 feet, and so on. In another example of groupings, device locations could be grouped to take the form of "within 2 feet of the center of the room", "centered between the right side of the bed and the wall and 2 feet from the foot of the bed along the bed axis" and so on, or, as another example of device locations groupings, the room could be divided into defined quadrants with length as an x axis and width as a y axis and a set convention on the location of the origin such that the grouping could be, for example, within 1 foot of (1,1), (1,3), (1,5), (1,7), (1,9), (3,1), (3,3), (3,7) and so on. In another example of groupings, the UVC reflectivity can be grouped to take the form of "standard low level reflection", "25% average reflection of surfaces", "50% average reflection", and so on, or the groupings could include regions of the room where each region has a different level. [0053] It should be apparent that these are just a few examples of logical groupings. It should be apparent that the extent to which measurable and model-able (simulation) parameters can be grouped or generalized is proportional to how accurate the prediction of UVC disinfection needs to be. The inventors have found that using a reasonable number of room dimension variations, with a limited number of device locations, a limited number of logical room objects in a limited number of locations and orientations, and a limited number of surface UVC reflectivity groupings, provides for sufficient predictive accuracy when solving the problems described herein for most UVC disinfection applications. [0054] The degree to which the measurements are sufficiently matched to the simulation via the look-up table could vary depending on the user's desires or other factors. Some applications may require, or some users may desire, that matches be exacting in terms of dimensions or object type or object placement or UVC reflection of surfaces or that a maximum number of targeted surfaces achieve a predicted dose, as examples. Alternatively, some applications or users may allow more approximate matches with large tolerances of mismatches of some parameters.

EXAMPLE 1

[0055] A mobile UVC device comprising a mobile base on caster wheels, a center structural support of high UVC reflectivity, a ring of 8 UVC amalgam type 145 watt high output lamps, a top base, a servo motor actuated sensor module rotatable to 90 degrees mounted to the top base, four time-of- flight laser rangefmders mounted at 90 degree increments about the central axis of the device facing horizontally, two UVC analog output photodiodes calibrated to 0-5000 microwatts per second per square centimeter with 180 degree horizontally oriented field of views via a diffuser assembly configured to measure direct and indirect UVC light, power circuitry and safety interlocks mounted within the mobile base, motion sensors connected to the safety interlocks mounted to the mobile base, a wireless communication module connecting to a remote user interface, a device mounted user interface, a microprocessor containing programming to provide full function to the device as described in the invention. EXAMPLE 2

[0056] A mobile UVC device comprising a mobile base containing a self-driving robot base with a powered traction unit, a center aluminum structural support of high UVC reflectivity, a ring of 3 UVC amalgam type 400 watt high output lamps, a top base, a servo motor actuated sensor module rotatable to 180 degrees mounted to the top base, two PrimeSense 3D scanners mounted at 180 degree increments about the central axis of the device facing horizontally, four UVC analog output photodiodes calibrated to 0-2000 microwatts per second per square centimeter with 90-degree horizontally-oriented and 45 -degree vertically-oriented field of views via a subassembly of photodiodes configured to measure direct and indirect UVC light, power circuitry and safety interlocks mounted within the mobile base, motion sensors connected to the safety interlocks mounted to the mobile base, a chord management assembly which unreels power chord as it moves, a wireless communication module connecting to a remote user interface, a device mounted user interfaces, a microprocessor containing programming to provide full function to the device as described in the invention.

EXAMPLE 3

[0057] A mobile UVC device comprising a mobile base, a center aluminum structural support of high UVC reflectivity, a ring of 4 UVC amalgam-type 325-watt high output lamps, a top base, power circuitry and safety interlocks mounted within the mobile base, motion sensors connected to the safety interlocks mounted to the mobile base, a user interface to control function of the device, and written guidelines allowing the operator to match the measurable room parameters with UVC device location and disinfection time derived at least partially from groupings of simulation in accordance to the teachings of the invention.

Claims

1. An ultraviolet disinfection system comprising

a mobile ultraviolet disinfection device comprising,

a UVC lamp assembly,

a mobile base, and

a control system; and

a look-up table containing information on a location to be disinfected;

wherein an operator can use the information in the look-up table to operate the UVC lamp assembly via the control system to achieve at least a targeted UVC irradiance, corresponding to a predicted UVC disinfection dose, on targeted surfaces in the location to be disinfected.

2. The ultraviolet disinfection system of claim 1 , wherein the information on the location to be disinfected comprises the dimensions of the location to be disinfected, the relative placement of the mobile ultraviolet disinfection device relative to the location to be disinfected, information on any objects contained in the location to be disinfected, and the UVC reflectivity of the location to be disinfected.

3. The ultraviolet disinfection system of claim 1, wherein the look-up table is at least

partially derived from computer simulation.

4. The ultraviolet disinfection system of claim 1, further comprising at least one UVC light sensor, whereby the at least one UVC light sensor provides feedback in the form of an aggregate UVC reflectance level as seen from the location to be disinfected.

5. The ultraviolet disinfection system of claim 1, further comprising at least one distance measuring sensor, whereby the at least one distance measuring sensor can be used to automatically determine the dimensions of the room, the relative placement of the mobile ultraviolet disinfection device relative to the location to be disinfected, and the location and dimensions of any objects contained in the location to be disinfected.

6. The ultraviolet disinfection system of claim 1, further comprising a microprocessor, at least one UVC light sensor, at least one distance measuring sensor, and a software program, wherein the microprocessor is operatively coupled to the control system, wherein the software program is executing on the microprocessor, wherein the microprocessor receives information on an aggregate UVC reflectance level in the location to be disinfected and information on the location to be disinfected and the software program uses those as inputs into the look-up table to provide automated commands to the control system.

7. The ultraviolet disinfection system of claim 6, wherein the mobile base further comprises a powered traction unit, wherein the powered traction unit is operatively coupled to the microprocessor, whereby the mobile ultraviolet disinfection device may be moved from one location to be disinfected to another, or moved within the location to be disinfected.

8. The ultraviolet disinfection system of claim 1, wherein the mobile ultraviolet disinfection device is an airborne device, and wherein the mobile base further comprises an aerial propulsion system for movement about the location to be disinfected.

9. The ultraviolet disinfection system of claim 6, wherein the mobile base further comprises an aerial propulsion system, wherein the aerial propulsion system is operatively coupled to the microprocessor, whereby the mobile ultraviolet disinfection device may be moved from one location to be disinfected to another, or moved within the location to be disinfected.

10. A method for disinfecting a location comprising the steps of

generating a look-up table containing information on the location to be disinfected;

placing a mobile ultraviolet disinfection device inside the location to be disinfected, the mobile ultraviolet disinfection device comprising

a UVC lamp assembly,

a mobile base, and

a control system; and

using the information in the look-up table to operate the UVC lamp assembly via the control system to achieve at least a targeted UVC irradiance, corresponding to a predicted UVC disinfection dose, on targeted surfaces in the location to be disinfected.

11. The method for disinfecting a location of claim 10, wherein the mobile ultraviolet

disinfection device further comprises a microprocessor;

at least one UVC light sensor;

at least one distance measuring sensor; and

a software program; wherein the microprocessor is operatively coupled to the control system, wherein the software program is executing on the microprocessor, wherein the microprocessor receives information on an aggregate UVC reflectance level in the location to be disinfected and information on the location to be disinfected and the software program uses those as inputs into the look-up table to provide automated commands to the control system.