Method and system for ultraviolet germicidal irradiation simulation

Abstract

Herein is disclosed a method for simulating ultraviolet germicidal irradiation (UVGI) of a subject microbe in a room, the method comprising: generating a 3D model of the room; receiving irradiance data associated with the UVGI source; receiving a base susceptibility for the subject microbe; simulating a surface disinfection by the first UVGI source by: selecting a point on the surface; determining a distance from the point to the first UVGI source; determining an irradiance intensity for the point based on the irradiance data; receiving a susceptibility coefficient for the surface; determining an effective susceptibility for the subject microbe based on the base susceptibility and the susceptibility coefficient; and determining a first microbe reduction function for the subject microbe.

Description

METHOD AND SYSTEM FOR ULTRAVIOLET GERMICIDAL IRRADIATION SIMULATIONTechnical Field

[0001] The present disclosure is directed to methods and systems for ultraviolet germicidal irradiation. More particularly, the present disclosure is directed to methods and systems for simulating ultraviolet germicidal irradiation in a room.Background

[0002] Ultraviolet germicidal irradiation (UVGI) may be used to sanitize an area, for example a room in a building. Quantifying the performance of a UVGI system in such an area is a complex and multivariate problem. The geometry of the area, the susceptibility of affected microbes, and other like factors can impact the performance of a UVGI system.

[0003] Current systems and methods for quantifying the performance of a UVGI system typically use one or more imprecise estimates to predict UVGI performance in a particular application. Such estimates may also be used to allocate resources of a UVGI system in such an application.

[0004] There is a general desire for an improved system and method of simulating ultraviolet germicidal irradiation in a given application, for example in a room.

[0005] The foregoing examples of the related art and limitations related thereto are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.Summary

[0006] Further aspects and example embodiments are illustrated in the accompanying drawings and / or described in the following description.

[0007] One aspect of the invention provides a method for simulating ultraviolet germicidal irradiation (UVGI) of a subject microbe in a room, the method comprising: generating a 3D model of the room, wherein the 3D model comprises a location of a first UVGI source andone or more surfaces; receiving irradiance data associated with the UVGI source, wherein the irradiance data relates a distance from the first UVGI source to an irradiance intensity; receiving a base susceptibility for the subject microbe; for one of the surfaces in the 3D model, simulating a surface disinfection by the first UVGI source by: selecting a point on the surface; determining a distance from the point to the first UVGI source; determining an irradiance intensity for the point based on the irradiance data; receiving a susceptibility coefficient for the surface; determining an effective susceptibility for the subject microbe based on the base susceptibility and the susceptibility coefficient; and determining a first microbe reduction function for the subject microbe based on the effective susceptibility and the irradiance intensity.

[0008] In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following detailed descriptions.Brief Description of the Drawings

[0009] The accompanying drawings illustrate non-limiting example embodiments of the invention.

[0010] Fig. 1 is a block diagram of a method for simulating ultraviolet germicidal irradiation (UVGI) of a subject microbe in a room, according to an example embodiment of the present invention.Description

[0011] Throughout the following description, specific details are set forth in order to provide a more thorough understanding of the invention. However, the invention may be practiced without these particulars. In other instances, well known elements have not been shown or described in detail to avoid unnecessarily obscuring the invention. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive sense.

[0012] Fig. 1 is a block diagram of method 100 for simulating ultraviolet germicidal irradiation (UVGI) of a subject microbe in a room, according to an example embodiment of the present invention. Method 100 comprises:• step 102: generating a 3D model of the room, wherein the 3D model comprises a location of a first UVGI source and one or more surfaces;• step 104: receiving irradiance data associated with the UVGI source, wherein the irradiance data relates a distance from the first UVGI source to an irradiance intensity;• step 106: receiving a base susceptibility for the subject microbe;• step 108: for one of the surfaces in the 3D model, simulating a surface disinfection by the first UVGI source by:• step 110: selecting a point on the surface;• step 112: determining a distance from the point to the first UVGI source;• step 114: determining an irradiance intensity for the point based on the irradiance data;• step 116: receiving a susceptibility coefficient for the surface;• step 118: determining an effective susceptibility for the subject microbe based on the base susceptibility and the susceptibility coefficient; and• step 120: determining a first microbe reduction function for the subject microbe based on the effective susceptibility and the irradiance intensity.

[0013] Some embodiments of method 100 further comprise receiving an exposure time for the first UVGI source, and determining a log-reduction for the subject microbe based on the microbe reduction function and exposure time. The log-reduction models a log reduction, meaning a 10X reduction, in the subject microbe for the surface.

[0014] Method 100 may further comprise generating a plurality of microbe reduction functions, and determining a total microbe reduction function based on the plurality of microbe reduction functions. For example, method 100 may comprise determining a second microbe reduction function for a second UVGI source, and determining a total microbe reduction function based on the first microbe reduction function and the second microbe reduction function.

[0015] In some embodiments, determining the total microbe reduction function comprises determining the first UVGI source has line of sight to the point, and determining the second UVGI source has line of sight to the point. Determining one or both of the first and second UVGI source have line of sight to the point may comprise:• modelling a first camera at the location of the first UVGI source in the 3D model and having a field-of-view equal to a field-of-view of the first UVGI source;• modelling a second camera at the location of the second UVGI source in the 3D model and having a field-of-view equal to a field-of-view of the second UVGI source;• generating a first UVGI point-of-view (POV) model from the 3D model, wherein the first UVGI POV model comprises a heatmap of irradiance by the first UVGI source and irradiance by the second UVGI source from the perspective of the first UVGI source;• generating a second UVGI point-of-view (POV) model from the 3D model, wherein the second UVGI POV model comprises a heatmap of irradiance by the first UVGI source and irradiance by the second UVGI source from the perspective of the second UVGI source; and• determining the total microbe reduction function comprises determining the total microbe reduction function based on the first UVGI POV model and the second UVGI POV model.

[0016] Method 100 may further comprise reducing the complexity of the UVGI POV model. For example, reducing the complexity of the first UVGI POV model may comprise dividing the first UVGI POV model into subsections, and generating a value for each of the subsections based on a maximum value within each of the subsections. In some embodiments, the first UVGI POV model comprises a set of pixels, dividing the first UVGI POV model into subsections comprises dividing the pixels in the set of pixels into subsections of four adjoining pixels, and generating the value for each of the subsections comprises determining a maximum value of the four pixels within each of the subsections.

[0017] Reducing the complexity of the UVGI POV model may further comprise dividing the subsections into secondary subsections of four adjoining subsections, and generating a value for each of the secondary subsections by determining a maximum value of the four subsections within each of the secondary subsections.

[0018] Some embodiments of method 100 may be at least partially performed using a graphics processing unit (GPU). A GPU is a hardware processor specifically designed to process graphical data. Where method 100 is at least partially performed by a GPU, method 100 may comprise determining the first UVGI source has line of sight to the point with a GPU. Determining the first UVGI source has line of sight to the point with the GPU may further comprise raycasting a first set of rays from the UVGI source to the point with the GPU.

[0019] Determining the first UVGI source has line of sight to the point with the GPU may comprise, with the GPU, determining a one of the rays in the first set of rays intersects an object between the UVGI source and the point, and raycasting a second set of rays from the UVGI source to the point with the GPU, wherein the second set of rays forms a cone about the one of the rays.

[0020] Some embodiments of method 100 may further comprise generating an irradiance heatmap of the room based on the minimum irradiance and maximum irradiance.Generating a heatmap may provide a manner in which to display otherwise complex and extensive data, such as the distribution of irradiance in a room. Generating the irradiance heatmap may comprise receiving a viewer location in the 3D model, generating a viewer UVGI POV model based on the viewer location and the first UVGI source, determining a minimum irradiance and a maximum irradiance based on the first UVGI POV model, generating a normalized irradiance heatmap based on the viewer UVGI POV model, minimum irradiance, and maximum irradiance, and assigning a color to the normalized irradiance heatmap.

[0021] Generating the irradiance heatmap may comprise:• receiving the viewer location;• determining a minimum irradiance and a maximum irradiance by:o for one or more of the UVGI sources in the 3D model, generate a UVGI POV model based on one or more of the UVGI sources and the viewer location; o determine the minimum irradiance and the maximum irradiance from the generated UVGI POV models;• generating a normalized heatmap by:o generating a viewer UVGI POV model based on the viewer location and one or more of the UVGI sources in the 3D model;o normalizing the viewer UVGI POV model based on the minimum irradiance and the maximum irradiance; ando assigning a plurality of color values to each pixel in the normalized viewer UVGI POV model.

[0022] Determining the minimum irradiance and the maximum irradiance may comprise raycasting a first set of rays from the UVGI source to a plurality of surfaces within the room with the GPU. Generating the irradiance heatmap may further comprise one or more of:• identifying one or more areas of the heatmap not covered by the raycasting, and interpolating an irradiance for each of the areas;• identifying one or more discontinuous areas of the heatmap, and interpolating an irradiance for each of the discontinuous areas; and• generating an image comprising a plurality of pixels, wherein each pixel of the image represents an irradiance intensity.

[0023] Some embodiments of method 100 may comprise generating an updated microbe reduction function from an updated UVGI source location. For example, method 100 may further comprise receiving an updated location of the first UVGI source, and updating the first microbe reduction function for the subject microbe based on the updated location of the first UVGI source. Updating the first microbe reduction function may comprise determining a difference between the original location of the first UVGI source and the updated location of the first UVGI source, and updating the first microbe reduction function based on the difference. Updating the first microbe reduction function may further comprise confirming the updated location of the first UVGI source is within the room by raycasting from the updated location of the first UVGI source to the one of the surfaces.

[0024] Some embodiments of the present invention may provide a system for simulating ultraviolet germicidal irradiation (UVGI) of a subject microbe in a room. For example, the system may comprise a computing device programmed to perform the method of claim 100, or any of the other methods disclosed herein.

[0025] While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additionsand sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are consistent with the broadest interpretation of the specification as a whole.Interpretation of Terms

[0026] Unless the context clearly requires otherwise, throughout the description and the claims:• “comprise”, “comprising”, and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”;• “connected”, “coupled”, or any variant thereof, means any connection or coupling, either direct or indirect, between two or more elements; the coupling or connection between the elements can be physical, logical, or a combination thereof;• “herein”, “above”, “below”, and words of similar import, when used to describe this specification, shall refer to this specification as a whole, and not to any particular portions of this specification;• “or”, in reference to a list of two or more items, covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list;• the singular forms “a”, “an”, and “the” also include the meaning of any appropriate plural forms.

[0027] Words that indicate directions such as “vertical”, “transverse”, “horizontal”, “upward”, “downward”, “forward”, “backward”, “inward”, “outward”, “vertical”, “transverse”, “left”, “right”, “front”, “back”, “top”, “bottom”, “below”, “above”, “under”, and the like, used in this description and any accompanying claims (where present), depend on the specific orientation of the apparatus described and illustrated. The subject matter described herein may assume various alternative orientations. Accordingly, these directional terms are not strictly defined and should not be interpreted narrowly.

[0028] Embodiments of the invention may be implemented using specifically designed hardware, configurable hardware, programmable data processors configured by theprovision of software (which may optionally comprise “firmware”) capable of executing on the data processors, special purpose computers or data processors that are specifically programmed, configured, or constructed to perform one or more steps in a method as explained in detail herein and / or combinations of two or more of these. Examples of specifically designed hardware are: logic circuits, application-specific integrated circuits (“ASICs”), large scale integrated circuits (“LSIs”), very large scale integrated circuits (“VLSIs”), and the like. Examples of configurable hardware are: one or more programmable logic devices such as programmable array logic (“PALs”), programmable logic arrays (“PLAs”), and field programmable gate arrays (“FPGAs”). Examples of programmable data processors are: microprocessors, digital signal processors (“DSPs”), embedded processors, graphics processors, math co-processors, general purpose computers, server computers, cloud computers, mainframe computers, computer workstations, and the like. For example, one or more data processors in a control circuit for a device may implement methods as described herein by executing software instructions in a program memory accessible to the processors.

[0029] Processing may be centralized or distributed. Where processing is distributed, information including software and / or data may be kept centrally or distributed. Such information may be exchanged between different functional units by way of a communications network, such as a Local Area Network (LAN), Wide Area Network (WAN), or the Internet, wired or wireless data links, electromagnetic signals, or other data communication channel.

[0030] For example, while processes or blocks are presented in a given order, alternative examples may perform routines having steps, or employ systems having blocks, in a different order, and some processes or blocks may be deleted, moved, added, subdivided, combined, and / or modified to provide alternative or subcombinations. Each of these processes or blocks may be implemented in a variety of different ways. Also, while processes or blocks are at times shown as being performed in series, these processes or blocks may instead be performed in parallel, or may be performed at different times.

[0031] In addition, while elements are at times shown as being performed sequentially, they may instead be performed simultaneously or in different sequences. It is therefore intended that the following claims are interpreted to include all such variations as are within their intended scope.

[0032] Software and other modules may reside on servers, workstations, personal computers, tablet computers, image data encoders, image data decoders, PDAs, colorgrading tools, video projectors, audio-visual receivers, displays (such as televisions), digital cinema projectors, media players, and other devices suitable for the purposes described herein. Those skilled in the relevant art will appreciate that aspects of the system can be practised with other communications, data processing, or computer system configurations, including: Internet appliances, hand-held devices (including personal digital assistants (PDAs), wearable computers, all manner of cellular or mobile phones, multi-processor systems, microprocessor-based or programmable consumer electronics (e.g., video projectors, audio-visual receivers, displays, such as televisions, and the like), set-top boxes, color-grading tools, network PCs, mini-computers, mainframe computers, and the like.

[0033] The invention may also be provided in the form of a program product. The program product may comprise any non-transitory medium which carries a set of computer-readable instructions which, when executed by a data processor, cause the data processor to execute a method of the invention. Program products according to the invention may be in any of a wide variety of forms. The program product may comprise, for example, non-transitory media such as magnetic data storage media including floppy diskettes, hard disk drives, optical data storage media including CD ROMs, DVDs, electronic data storage media including ROMs, flash RAM, EPROMs, hardwired or preprogrammed chips (e.g., EEPROM semiconductor chips), nanotechnology memory, or the like. The computer-readable signals on the program product may optionally be compressed or encrypted.

[0034] In some embodiments, the invention may be implemented in software. For greater clarity, “software” includes any instructions executed on a processor, and may include (but is not limited to) firmware, resident software, microcode, and the like. Both processing hardware and software may be centralized or distributed (or a combination thereof), in whole or in part, as known to those skilled in the art. For example, software and other modules may be accessible via local memory, via a network, via a browser or other application in a distributed computing context, or via other means suitable for the purposes described above.

[0035] Some embodiments and / or features of the present invention may comprise or reference artificial intelligence (Al), including machine learning (ML). Where a feature of thepresent invention is described as comprising a machine learning algorithm, unless otherwise stated, the machine learning algorithm may comprise one or more of:• an untrained machine learning model;• a trained machine learning model, for example a training convolutional neural network (CNN), recurrent neural network (RNN), and the like;• a lookup table; and• a software algorithm.

[0036] Where a component (e.g. a software module, processor, assembly, device, circuit, etc.) is referred to above, unless otherwise indicated, reference to that component (including a reference to a “means”) should be interpreted as including as equivalents of that component any component which performs the function of the described component (i.e. , that is functionally equivalent), including components which are not structurally equivalent to the disclosed structure which performs the function in the illustrated exemplary embodiments of the invention.

[0037] Specific examples of systems, methods and apparatus have been described herein for purposes of illustration. These are only examples. The technology provided herein can be applied to systems other than the example systems described above. Many alterations, modifications, additions, omissions, and permutations are possible within the practice of this invention. This invention includes variations on described embodiments that would be apparent to the skilled addressee, including variations obtained by: replacing features, elements and / or acts with equivalent features, elements and / or acts; mixing and matching of features, elements and / or acts from different embodiments; combining features, elements and / or acts from embodiments as described herein with features, elements and / or acts of other technology; and / or omitting combining features, elements and / or acts from described embodiments.

[0038] Various features are described herein as being present in “some embodiments”. Such features are not mandatory and may not be present in all embodiments. Embodiments of the invention may include zero, any one or any combination of two or more of such features. This is limited only to the extent that certain ones of such features are incompatible with other ones of such features in the sense that it would be impossible for a person of ordinary skill in the art to construct a practical embodiment that combines suchincompatible features. Consequently, the description that “some embodiments” possess feature A and “some embodiments” possess feature B should be interpreted as an express indication that the inventors also contemplate embodiments which combine features A and B (unless the description states otherwise or features A and B are fundamentally incompatible).

[0039] It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions, omissions, and sub-combinations as may reasonably be inferred. The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole.

Claims

CLAIMS1. A method for simulating ultraviolet germicidal irradiation (UVGI) of a subject microbe in a room, the method comprising:generating a 3D model of the room, wherein the 3D model comprises a location of a first UVGI source and one or more surfaces;receiving irradiance data associated with the UVGI source, wherein the irradiance data relates a distance from the first UVGI source to an irradiance intensity;receiving a base susceptibility for the subject microbe;for one of the surfaces in the 3D model, simulating a surface disinfection by the first UVGI source by:selecting a point on the surface;determining a distance from the point to the first UVGI source; determining an irradiance intensity for the point based on the irradiance data;receiving a susceptibility coefficient for the surface;determining an effective susceptibility for the subject microbe based on the base susceptibility and the susceptibility coefficient; and determining a first microbe reduction function for the subject microbe based on the effective susceptibility and the irradiance intensity.

2. The method of claim 1 , further comprising:receiving an exposure time for the first UVGI source; anddetermining a log-reduction for the subject microbe based on the microbe reduction function and exposure time.

3. The method of either of claims 1 and 2, further comprising:determining a second microbe reduction function for a second UVGI source; anddetermining a total microbe reduction function based on the first microbe reduction function and the second microbe reduction function.

4. The method of claim 3, wherein determining the total microbe reduction function comprises:determining the first UVGI source has line of sight to the point; and determining the second UVGI source has line of sight to the point.

5. The method of claim 4, wherein:determining the first UVGI source has line of sight to the point comprises: modelling a first camera at the location of the first UVGI source in the 3D model and having a field-of-view equal to a field-of-view of the first UVGI source;modelling a second camera at the location of the second UVGI source in the 3D model and having a field-of-view equal to a field-of-view of the second UVGI source;generating a first UVGI point-of-view (POV) model from the 3D model, wherein the first UVGI POV model comprises a heatmap of irradiance by the first UVGI source and irradiance by the second UVGI source; determining the second UVGI source has line of sight to the point comprises:generating a second UVGI point-of-view (POV) model from the 3D model, wherein the second UVGI POV model comprises a heatmap of irradiance by the first UVGI source and irradiance by the second UVGI source; anddetermining the total microbe reduction function comprises determining the total microbe reduction function based on the first UVGI POV model and the second UVGI POV model.

6. The method of claim 5, further comprising reducing the first UVGI POV model by dividing the first UVGI POV model into subsections, and generating a value for each of the subsections based on a maximum value within each of the subsections.

7. The method of claim 6, wherein:the first UVGI POV model comprises a set of pixels;dividing the first UVGI POV model into subsections comprises dividing the pixels in the set of pixels into subsections of four adjoining pixels; and generating the value for each of the subsections comprises determining a maximum value of the four pixels within each of the subsections.

8. The method of claim 7, further comprising:dividing the subsections into secondary subsections of four adjoining subsections; andgenerating a value for each of the secondary subsections by determining a maximum value of the four subsections within each of the secondary subsections.

9. The method according to any one of claims 5 to 8, wherein determining the first UVGI source has line of sight to the point comprises determining the first UVGI source has line of sight to the point with a GPU.

10. The method according to claim 9, wherein determining the first UVGI source has line of sight to the point with the GPU comprises raycasting a first set of rays from the UVGI source to the point with the GPU.

11. The method according to claim 10, wherein determining the first UVGI source has line of sight to the point with the GPU comprises, with the GPU:determining a one of the rays in the first set of rays intersects an object between the UVGI source and the point; andraycasting a second set of rays from the UVGI source to the point with the GPU, wherein the second set of rays forms a cone about the one of the rays.

12. The method according to any one of claims 4 to 11 , further comprising generating an irradiance heatmap of the room based on the first UVGI (POV) model.

13. The method according to claim 12, wherein generating the irradiance heatmap comprises:receiving a viewer location in the 3D model;generating a viewer UVGI POV model based on the viewer location and the first UVGI source;determining a minimum irradiance and a maximum irradiance based on the first UVGI POV model;generating a normalized irradiance heatmap based on the viewer UVGI POV model, minimum irradiance, and maximum irradiance; andassigning a color to the normalized irradiance heatmap.

14. The method according to claim 13, wherein determining the minimum irradiance and the maximum irradiance comprise raycasting a first set of rays from the UVGI source to a plurality of surfaces within the room with the GPU.

15. The method according to claim 14, wherein generating the irradiance heatmap comprises identifying one or more areas of the heatmap not covered by the raycasting, and interpolating an irradiance for each of the areas.

16. The method according to either of claims 14 and 15, wherein generating the irradiance heatmap comprises identifying one or more discontinuous areas of the heatmap, and interpolating an irradiance for each of the discontinuous areas.

17. The method according to any one of claims 12 to 16, wherein generating the irradiance heatmap comprises generating an image comprising a plurality of pixels, wherein each pixel of the image represents an irradiance intensity.

18. The method according to any one of claims 1 to 17, further comprising:receiving an updated location of the first UVGI source; andupdating the first microbe reduction function for the subject microbe based on the updated location of the first UVGI source.

19. The method according to claim 18, wherein updating the first microbe reduction function comprises determining a difference between the original location of the first UVGI source and the updated location of the first UVGI source, and updating the first microbe reduction function based on the difference.

20. The method according to either of claims 18 and 19, wherein receiving the updated location of the first UVGI source comprises confirming the updated location of the first UVGI source is within the room by raycasting from the updated location of the first UVGI source to the one of the surfaces.

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