CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority benefit from co-pending U.S. Provisional Patent Application No. 63/267,272, entitled “ULTRAVIOLET ILLUMINATOR WITH NETWORK COMMUNICATION” (docket number 3083- 003-02), filed on January 28, 2022, which, to the extent not inconsistent with the disclosure herein, is incorporated by reference in its entirety.

SUMMARY

According to an embodiment, an ultraviolet illuminator includes a kryptonhalogen emission source configured to output far ultraviolet-C (far UV-C) light into an illuminated region, and an electronic controller operatively coupled to the krypton-halogen emission source. The electronic controller may include an krypton-halogen emission source driver configured to control the krypton-halogen emission source. The electronic controller may include a logic circuit operatively coupled to the krypton-halogen emission source driver, and configured to control the krypton-halogen emission source driver, and a communication interface operatively coupled to the logic circuit. The communication interface may be configured for bidirectional communication according to a digital interface protocol. In an embodiment, the electronic controller is configured to control the krypton-halogen emission source to operate according to data received by the communication interface. In an embodiment, the far UV-C light is characterized by a passband that includes wavelengths between 200 nanometers and 230 nanometers wavelength. In another embodiment, the far UV-C light is characterized by a passband that includes wavelengths between 200 i nanometers and 235 nanometers wavelength. In an embodiment, the ultraviolet illuminator includes one or more sensors operatively coupled to the logic circuit and configured to sense a parameter corresponding to the illuminated region. The logic circuit may select an operation parameter for the krypton-halogen emission source responsive to the sensed condition.

According to an embodiment, a computer method may include reading first control data including a schedule for far UV-C illumination with a first electronic controller disposed in a first housing, inferring a state of an exception condition corresponding to a first illuminated region, and driving, with the first electronic controller, a krypton-halogen emission source disposed in the first housing to output far UV-C light into the first illuminated region according to whether the exception condition is negative or positive. While maintaining driving of the krypton-halogen emission source, the method includes looping to again read the first control data, inferring the state of the exception condition, and continuing or changing the output of the krypton-halogen emission source according to the most recently inferred exception condition. The method may include initiating an ultraviolet illuminator and the electronic controller by transmitting the control data to the first electronic controller from a computing device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a system including an ultraviolet illuminator with a communication interface, according to an embodiment.

FIG. 2 is a block diagram of a system including an ultraviolet illuminator, according to another embodiment.

FIG. 3 is a block diagram of a system including an ultraviolet illuminator, according to another embodiment.

FIG. 4 is a block diagram of a system including an ultraviolet illuminator, according to another embodiment. FIG. 5 is a diagram of a system including a plurality of ultraviolet illuminators corresponding to respective different illuminated regions, according to an embodiment.

FIG. 6 is a flowchart showing a computer method for operating one or more ultraviolet illuminators, according to embodiments.

DETAILED DESCRIPTION

In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. Other embodiments may be used and/or other changes may be made without departing from the spirit or scope of the disclosure.

FIG. 1 is a block diagram of a system 100 including an ultraviolet illuminator 102 with network communication, according to an embodiment. The ultraviolet illuminator 102 includes a krypton-halogen emission source 104 configured to output far ultraviolet (far UV-C) light into an illuminated region 106 and an electronic controller 108 operatively coupled to the krypton-halogen emission source 104.

As used herein, unless context indicates to the contrary, terms such as krypton light source, krypton-halogen emission source, krypton-halogen lamp, excimer lamp, and the like will be understood to refer to a far UV-C light source that operates by a krypton-halogen exciplex decomposition, accompanied by emission of light energy in the far UV-C band between 200 and 230 nanometers or between 200 and 235 nanometers wavelength. Owing to other types of interactions, such as halogen-halogen decomposition and band spreading, the krypton-halogen emission source may output ultraviolet illumination across a wavelength range longer than the far UV-C band, such as between 230 or 235 nanometers and 280 nanometers. As will be described more fully below, the krypton-halogen emission source may include one or more filters for preventing the longer wavelength range from entering the illuminated region 106.

Decomposition of a krypton-chlorine pair results in 222 nanometer emission. Decomposition of a krypton-bromine pair results in 207 nanometer emission. Band spreading and other interactions may broaden these emission spectra to span a larger range of wavelengths. Wavelengths between 200 and 230 or 235 nanometers are especially effective for rendering infectious particles, such as viruses or bacteria, non-infectious while also being relatively safe for human and animal exposure. Generally, such far UV-C light energy does not readily pass through skin epidermis or corneal tissues, and thus does not ionize or damage underlying tissues at moderate exposures.

Still referring to FIG. 1, The electronic controller 108 may include a krypton-halogen emission source driver 110 configured to control the kryptonhalogen emission source 104. For example, the krypton-halogen emission source driver 110, may include a solid-state or other relay for selectively coupling the krypton-halogen emission source 104 to a suitable power supply. In some embodiments, the krypton-halogen emission source driver 110 may include an electrical converter configured to convert battery or wall power to a signal appropriate for driving the krypton-halogen emission source 104. The electronic controller 108 also includes a logic circuit 112 operatively coupled to the krypton- halogen emission source driver 110 and configured to control the krypton- halogen emission source driver 110 to cause output, non-output, filtered, dimmed, or other far UV-C light.

The ultraviolet illuminator 102 may further include one or more sensor(s) 118 configured to detect parameters corresponding to the illuminated region 106 that the krypton-halogen emission source is positioned to illuminate or irradiate. Aspects of the sensor(s) 118 are described more fully below.

The electronic controller 108 and/or the logic circuit 112, may be operatively coupled to a digital communication interface 114 (also referred to as simply "communication interface"). The communication interface 114 is configured for bidirectional digital communication according to an interface protocol. The electronic controller 108 may be configured to control the kryptonhalogen emission source 104 to operate according to data received through the communication interface 114.

Far ultraviolet-C (also referred to as far UV-C, or simply UV-C herein) illumination is generally invisible to humans. The far UV-C light may be characterized by a passband that includes wavelengths between 200 nm and 230 nm, and substantially excluding ultraviolet wavelengths greater than 230 nm. In an embodiment, the far UV-C light may be characterized by a passband that includes wavelengths between 200 nm and 235 nm, and substantially excluding ultraviolet wavelengths greater than 235 nm.

The krypton-halogen emission source 104 may include a krypton-chloride emission source configured to output far-UV-C light primarily at 222 nanometers wavelength. Additionally or alternatively, the krypton-halogen emission source includes a krypton-bromide emission source configured to output far-UV-C light primarily at 207 nanometers wavelength. In an embodiment, the krypton-halogen emission source includes a krypton-chloride emission source configured to output far-UV-C light primarily at 222 nanometers wavelength and a kryptonbromide emission source configured to output far-UV-C light primarily at 207 nanometers wavelength.

The communication interface 114 may be configured to receive data corresponding to an on-state, data corresponding to an off-state, or other types of data from a computer 116. The electronic controller 108 may be configured to cause the krypton-halogen emission source driver 108 to control krypton-halogen emission source 104 to emit the far UV-C light when the communication interface 114 receives data corresponding to the on-state, and to not emit the far UV-C light when the communication interface 114 receives data corresponding to the off-state.

According to an embodiment, the electronic controller 108 is configured to receive control data including an ultraviolet light emission schedule from a computing device 116 via the communication interface 114. In an embodiment, the electronic controller 108 includes a clock and the received ultraviolet emission schedule causes the electronic controller 108 to drive the kryptonhalogen emission source 104 according to a time of day. The ultraviolet light emission schedule may include a plurality of ultraviolet light intensities as a function of time such that the logic circuit 112 controls the krypton-halogen emission source driver 110 to drive the krypton-halogen emission source 104 to output a corresponding plurality of ultraviolet light intensities. For example, the krypton-halogen emission source driver 110 may output a pulse-width modulated drive signal to the krypton-halogen emission source 104 to cause the krypton- halogen emission source 104 to output the plurality of light intensities according to a selected one of a plurality of duty cycles.

In an embodiment, the communication interface 114 is configured to receive data corresponding to a presence of at least one person 120 from a electronic device 402. In an embodiment, the communication interface 114 may include a wireless interface and may communicate according to various protocols such as WiFi (e.g., IEEE 802.11 x), GSM (cellular), CDMA (cellular), Bluetooth, and/or Zigbee, time-gated (e.g. "5G"), etc. Additionally, or alternatively, the communication interface 114 may include a wired interface. The wired interface may include various types such as Ethernet, RS-232, RS-485, and/or USB, etc. Additionally or alternatively, the communication interface 114 may include an optical interface. Preferably, the communication interface 114 is bidirectional.

According to embodiments, the ultraviolet illuminator 102 includes at least one sensor 118 operatively coupled to the logic circuit 112 and aligned to sense a physical parameter corresponding to the illuminated region 106. The ultraviolet light emission schedule may includes a function of the physical parameter (which may also be referred to as an exception) such that the logic circuit 112 causes the krypton-halogen emission source driver 110 to drive the krypton-halogen emission source 104 according to the sensed physical parameter and the function of the physical parameter. The ultraviolet illuminator 102 may transmit the sensed physical parameter, the exception state, or the physical parameter and the exception state to a computer 116 and/or to another ultraviolet illuminator. FIG. 2 is a block diagram of a system 200 including an ultraviolet illuminator 102, according to another embodiment. The krypton-halogen emission source 104 may be configured to output halogen-halogen emission extending to wavelengths longer than 230 or 235 nanometers. A filter 202 may be configured to block wavelengths longer than 230 or 235 nanometers

According to an embodiment, the logic circuit 112 is configured to control the filter 202 to cause removal or reduction of filtering of wavelengths longer than 230 or 235 nanometers responsive to data received by the communication interface 114. For example, data received by the communication interface 114 may identify one or more times when no human or animal is scheduled to be present in the illuminated region. The logic circuit 112 may include a clock and may actuate the filter 202 to cause longer wavelength output during at least a portion of the times when no human or animal is scheduled to be present in the illuminated region. This may be used to increase intensity of longer wavelength light, such as a passband extending from 200 nm to 280 nm wavelength, to enable higher germicidal effect during times when there are no humans or animals present. In another example, the communication interface 114 may receive data corresponding to presence of a person or animal in the illuminated region 106, and the logic circuit 112 may responsively control the filter to increase filtering to reduce or eliminate output of wavelengths longer than 230 or 235 nanometers when the person or animal is present.

FIG. 3 is a block diagram of a system 300 including an ultraviolet illuminator 102, according to another embodiment. The krypton-halogen emission source 104 may include a plurality of krypton-halogen emission sources 302, 304, 306. The logic circuit 112 may be configured to selectively and/or simultaneously enable more than one krypton-halogen emission source 302, 304, 306. This may be used, for example, to increase germicidal action when it is desirable to do so and/or reduce far UV-C intensity when it is appropriate, such as for controlling exposure to persons in the illuminated region 106.

In an embodiment, at least a first portion of the plurality of krypton-halogen emission sources 302, 304 is (are) filtered to prevent passage of light longer than 630 or 635 nanometers, and at least a second portion 306 of the krypton-halogen emission sources is (are) not filtered to prevent passage of light longer than 630 or 635 nanometers. The logic circuit 112 may be configured to selectively enable far UV-C emission by at least one of the first portion 302, 304 of the kryptonhalogen emission source when data received by the communication interface 114 or detected by one or more sensors 118 operatively coupled to the logic circuit 112 is indicative of at least possible presence of a human or animal in the illuminated region 106. Conversely, the logic circuit 112 may be configured to selectively enable output of wavelengths longer than 630 or 635 nanometers by at least one of the second portion 306 of the krypton-halogen emission sources only when data received by the communication interface 114 is indicative of no presence of a human or animal in the illuminated region 106. For example, the second portion 306 of the krypton-halogen emission sources may be configured to output ultraviolet emission greater than 630 or 635 nanometers wavelength, such as up to 680 nanometers wavelength.

FIG. 4 is a block diagram of a system 400 including an ultraviolet illuminator 102, according to another embodiment. The communication interface may be configured to receive data corresponding to presence of an electronic device 402 disposed on the body of a person 404 in the illuminated region 106. The electronic controller may configured to cause the krypton-halogen emission source driver to control krypton-halogen emission source to not emit the ultraviolet wavelength when the communication interface receives a command from the electronic device 402 for the ultraviolet illuminator 102 to enter and off- state while the electronic device 402 is present in the illuminated region.

In other embodiments, the presence of the electronic device 402 in the illuminated region 106 constitutes an exception to a schedule for illumination of the illuminated region 106 such that the electronic controller 108 is configured to cause output far UV-C illumination according to an exception schedule while the electronic device 402 is within range and within the illuminated region 106.

According to an embodiment, the electronic controller is configured to infer an amount of ultraviolet radiation received by the at least one person as a function previous presence of the electronic device 402 within the illuminated region 106, compare the amount of ultraviolet radiation received by the at least one person to an exposure limit, and cause the krypton-halogen emission source to not emit far UV-C illumination when the ultraviolet radiation inferred to have been received by the at least one person reaches a threshold corresponding to the exposure limit. In embodiments, the exposure limit to far UV-C light is 22 milliJoules (mJ) per square centimeter per day impinging on any given person.

The electronic device 402 may include an access badge, for example. In embodiments, the electronic device 402 includes a personal electronic device such as a cellular phone carried on the person of the at least one person 404. When the electronic device includes a location services function, the electronic device may run an ultraviolet control application configured to transmit the data corresponding to a presence of at least one person to the communication interface of the ultraviolet illuminator when a location reported by the location services function corresponds to an illuminated region 106.

FIG. 5 is a diagram of a system including a plurality of ultraviolet illuminators 102a, 102b, 102c corresponding to respective different illuminated regions 106a, 106b, 106c, according to an embodiment.

Referring to FIG. 4 in view of FIG. 5, the electronic device 402 may include a location services function such that the electronic device runs an ultraviolet control application configured to track ultraviolet radiation received from one or more ultraviolet illuminators 102a, 102b, 102c corresponding to illuminated regions 106a, 106b, 106c through which the electronic device 402 and the person 404 travel along a path 502. The ultraviolet control application may be configured to cause the electronic device 402 to transmit control data to the ultraviolet illuminator 102b including information about the amount of received ultraviolet illumination received during an exposure period. The ultraviolet illuminator 102b may be configured to adjust output of ultraviolet illumination responsive to the received control data.

The ultraviolet illuminator 102b may be further configured to transmit a duration of presence of the electronic device in the illuminated region 106b so that the transmitted duration of presence may be used by a set of ultraviolet illuminators 102a, 102b, 102c to control ultraviolet output. The electronic device 402 may include an ultraviolet sensor. The electronic device 402 may be configured to integrate data from the ultraviolet sensor and to transmit data to the communication interface of the ultraviolet illuminator when a predetermined amount of ultraviolet radiation has been received by the ultraviolet sensor.

According to an embodiment, the electronic device 402 includes a carbon dioxide sensor configured to sense a concentration of carbon dioxide differing from an atmospheric average carbon dioxide, an electronic device 402 logic circuit being configured to run a digital computer application from a non- transitory, computer-readable memory, the digital computer application being configured to transmit data corresponding to data received via the communication interface, the data including at least a fusion of data corresponding to the carbon dioxide concentration. The ultraviolet illuminator may be configured to increase an ultraviolet radiation flux responsive to receiving data from the electronic device 402 that an increased concentration of carbon dioxide is sensed. The increase in carbon dioxide concentration may correspond to a human density divided by a ventilation factor, which may be inferred to indicate a probability of increased detectable virus aerosol loading.

According to an embodiment, an ultraviolet illumination system 500 includes a second ultraviolet illuminator 102a, 102c, equipped similarly to the first ultraviolet illuminator 102b. The logic circuits 112 of the ultraviolet illuminator 102b and the second ultraviolet illuminator 102a, 102c may be synchronized and configured to cooperate to compare at least a relative time of receipt of a data signal from an electronic device 402 within a communication range of at least one of the first ultraviolet illuminator 102b and the second ultraviolet illuminator 102a, 102c to triangulate at least an approximate position of the electronic device 402. The logic circuit 112 of each ultraviolet illuminator 102a, 102b, 102c may be configured to determine if the triangulated position is within the respective illuminated region. The logic circuit 112 may be configured to cause the krypton emission illumination source 104 to output an amount of far UV-C light inferred to be received by the particular person 404 to not exceed an exposure limit if the triangulated position of the electronic device 402 is within the illuminated region 106.

According to an embodiment, the logic circuit 112 is configured to maintain a census of particular persons 120a, 120b and/or connected devices 116a, 116b having positions within at least one of the illuminated regions 106a, 106b. The logic circuit 112 may be configured to infer, from the census, that a particular person 120 has reached an integrated amount of far UV-C light at a control limit related to an ultraviolet exposure limit, and control the krypton-halogen emission source to cause the amount of far UV-C light emitted into the illuminated region 106 nominally illuminated by the ultraviolet illuminator 102 to not cause the person 120 to receive far UV-C light above the ultraviolet exposure limit.

According to an embodiment, the ultraviolet illuminator 102 may include a sensor 118 configured to distinguish between individual persons 120a, 120b in the illuminated region 106. In this case, the logic circuit 112 may be configured to maintain a census of particular persons 404 in one or more illuminated regions 106a, 106b, and to control the krypton-halogen emission source responsively.

For embodiments where the electronic device(s) 402 are present and where the sensor(s) 118 is configured to distinguish between individual persons 404, the electronic devices 402 and sensor(s) 118 may augment one another to provide reliable census data related to individual persons 404.

For an embodiment including an electronic device 402 in communication with the communication interface 114, an electronic device 402 may be configured to transmit, to the communication interface 114 of the ultraviolet illuminator 102b, census data corresponding to presence of a particular person 404 associated with the electronic device 402 within one or more illuminated regions 106b. The logic circuit 112 of the ultraviolet illuminator 102b may be configured to transmit the census data, via the communication interface 114, for receipt by another ultraviolet illuminator 102a, 102c. In this way, the ultraviolet illuminators 102a, 102b, 102c may be configured to cooperate to control an exposure of the particular person 404 to far UV-C light within a plurality of illuminated regions 106a, 106b, 106c.

In an embodiment, an electronic device 402 is configured to transmit, to an ultraviolet control application running on computer hardware 116 operatively coupled to the ultraviolet illuminator 102, census data corresponding to presence of a particular person 120 associated with the electronic device 402 within one or more illuminated regions 106a, 106b, 106c. The electronic controller 108 of the ultraviolet illuminator 102b may be configured to receive, via the communication interface 114, control data from the computer hardware 116 to control an exposure of the particular person 404 to far UV-C light within a plurality of illuminated regions 106a, 106b, 106c including the particular illuminated region 106b illuminated by the ultraviolet illuminator 102b.

In an embodiment, the electronic controller 108 of the ultraviolet illuminator 102 may include an occupancy sensor 118 operatively coupled to the logic circuit 112. The electronic controller 108 may be configured to control the krypton-halogen emission source 104 depending at least upon a sensed occupancy.

In an embodiment, the electronic controller 108 of the ultraviolet illuminator 102 may include a real time clock operatively coupled to the logic circuit 112. The electronic controller 108 may be configured to control the krypton-halogen emission source depending at least upon real time.

According to an embodiment, the logic circuit 112 is configured to select an output characteristic of the krypton-halogen emission source 104 depending at least upon one or more data messages received by the communication interface 114.

According to an embodiment, the logic circuit 112 is configured to control the krypton-halogen emission source 104 responsive to inferring a state of an ultraviolet exposure limit corresponding to residence time, distance, and/or view factor for one or more humans 120 in the illuminated region 106. According to an embodiment, the communication interface 114 is configured to receive communications originating in a second ultraviolet illuminator 102c disposed non-coincident with the ultraviolet illuminator 102b.

According to another embodiment, the communication interface 114 is configured to receive communications originating in a second ultraviolet illuminator 102c disposed coincident with (e.g., in the same housing 109 with) the ultraviolet illuminator 102b.

According to an embodiment, the communication interface 114 is configured transmit a communication from the logic circuit 112, the communication being selected to cause a response by a second ultraviolet emission device 102b.

According to an embodiment, the ultraviolet illuminator 102a is configured to sense a condition related to occupancy, a condition related to ventilation, or a condition related to occupancy and ventilation of the illuminated region 106a and to responsively output, from the logic circuit 112 and the communication interface 114, data selected to control illumination by a second ultraviolet illuminator 102b. For example, the condition related to occupancy, ventilation, or occupancy and ventilation of the illuminated region 106 may include carbon dioxide concentration. To enable this, the ultraviolet illuminator 102 may include a carbon dioxide sensor 118. In another approach, the communication interface 114 may operatively coupled to the carbon dioxide sensor 118. For example, the electronic controller may rely on carbon dioxide sensed by a carbon dioxide sensor included in a electronic device 402.

The ultraviolet illuminator 102 may include at least one sensor 118 operatively coupled to the logic circuit 106, the at least one sensor 118 being configured to sense a condition corresponding to presence of at least one person in the illuminated region 106. The at least one sensor 118 may include a carbon dioxide sensor configured to sense a concentration of carbon dioxide. The logic circuit may be configured to cause the krypton-halogen emission source driver to change an ultraviolet flux from the krypton-halogen emission source responsive to receiving data from the carbon dioxide sensor that an increased concentration of carbon dioxide is sensed. Accordingly, an increase in carbon dioxide concentration corresponding to a human density divided by a ventilation factor is inferred to indicate a higher probability of detectable virus aerosol loading, and responsively output a higher flux of ultraviolet radiation intended to denature viruses proportional to an inferred virus aerosol concentration in the air.

The ultraviolet illuminator 102 may include a sensor 118 including a microphone operatively coupled to a logic circuit 112. The logic circuit 112 may be configured to perform a Fourier transform on a signal from the microphone to produce a spectral noise signature and compare the spectral noise signature to a plurality of reference spectral noise signatures held in a non-transitory computer readable memory to obtain at least one best match. The plurality of reference spectral noise signatures may correspond to known numbers of persons in the region. The logic circuit 112 may be configured to obtain an inferred infectious particle concentration from at least one look-up-table (LUT) corresponding to at least one best matched reference spectral noise signatures.

The ultraviolet illuminator 102 may include at least one sensor 118 operatively coupled to the logic circuit, the at least one sensor being configured to sense a condition corresponding to presence of at least one person in the illuminated region. The communication interface may include a wireless line-of- sight communication interface configured to interrogate an electronic device 402, where the line-of-sight communication interface is characterized by an ability to communicate when the electronic device 402 is within the illuminated region.

Referring to FIG. 5, a system 500 may include a second ultraviolet illuminator, equipped similarly to the ultraviolet illuminator. The logic circuits of the ultraviolet illuminators may be synchronized and configured to cooperate to compare at least a relative time of receipt of a data signal from an electronic device 402 within a communication range of at least one of the first ultraviolet illuminator and the second ultraviolet illuminator to triangulate at least an approximate position of the electronic device 402. The logic circuit of each ultraviolet illuminator 102b, 102c may be configured to determine if the triangulated position is within the respective illuminated regions 106b, 106c. The logic circuit may be configured to cause the krypton-halogen emission source to output an amount of far UV-C light inferred to be received by the particular person to not exceed an exposure limit if the triangulated position of the electronic device 402 is within the illuminated region.

The logic circuit 112 may be configured to maintain a census of electronic devices having positions within at least one of the illuminated regions 106a, 106b, 106c. The logic circuit may be configured to infer, from the census, that a particular person has reached an integrated amount of far UV-C light at a control limit related to an ultraviolet exposure limit, and control the krypton-halogen emission source to cause the amount of far UV-C light emitted into the illuminated region nominally illuminated by the ultraviolet illuminator to not cause the person to receive far UV-C light above the ultraviolet exposure limit.

An electronic device 402 may be configured to transmit, to the communication interface of the ultraviolet illuminator, census data corresponding to presence of a particular person associated with the electronic device 402 within one or more illuminated regions 106. The logic circuit of the ultraviolet illuminator may be configured to transmit the census data for receipt by another ultraviolet illuminator, such that the ultraviolet illuminators are configured to cooperate to control an exposure of the particular person to far UV-C light within a plurality of illuminated regions.

An electronic device 402 may be configured to transmit, to an ultraviolet control application running on computer hardware operatively coupled to the ultraviolet illuminator, census data corresponding to presence of a particular person associated with the electronic device 402 within one or more illuminated regions 106. The electronic controller of the ultraviolet illuminator may be configured to receive control data from the computer hardware to control an exposure of the particular person to far UV-C light within a plurality of illuminated regions including the particular illuminated region illuminated by the ultraviolet illuminator.

The ultraviolet illuminator 102 may include visible light indicator 120 disposed to be visible from outside the first housing 119 and operatively coupled to the electronic controller 108. The visible light indicator 120 may be configured to be driven by the electronic controller 108 to indicate a state of output of the far UV-C illumination from the krypton-halogen emission source. For example, the electronic controller may be configured to drive the visible light indicator to output red light when the krypton-halogen emission source outputs wavelengths longer than 630 or 635 nanometers. Optionally, the visible light indicator 120 may include a red blinking light to make the potentially dangerous condition visible to a passerby.

The electronic controller 108 may be configured to drive the visible light indicator to output yellow light when the krypton-halogen emission source outputs wavelengths only within the range of 200 to 230 or 235 nanometers at a high power. The electronic controller may be configured to drive the visible light indicator to output green light when the krypton-halogen emission source outputs wavelengths only within the range of 200 to 230 or 235 nanometers at a low power or when the krypton-halogen emission source is not outputting any far UV- C light.

FIG. 6 is a flowchart showing a computer method 600 for operating one or more ultraviolet illuminators, according to embodiments. Referring to FIG. 6 in view of FIGS. 1-5, the computer method 600 may include, in step 604, reading first control data including a schedule for far UV-C illumination with a first electronic controller 108 disposed in a first housing 109. In step 612 a state of an exception condition corresponding to a first illuminated region 106 is inferred. Step 616 includes driving, with the first electronic controller 108, a krypton- halogen emission source 104 disposed in the first housing 109 to output far UV-C light into the first illuminated region when the inferred state of the exception condition is negative (i.e., when the exception condition does not exist).

The computer method 600 may further include, while maintaining driving of the krypton-halogen emission source 104, looping to again read the first control data, in step 604, and inferring the state of the exception condition, in step 612. The method 600 may include initiating the ultraviolet illuminator by, in step 602, transmitting the control data to the first electronic controller from a computing device 116.

Reading the first control data including the schedule for far UV-C illumination, in step 604, may include reading a time schedule for far UV-C illumination. Driving the krypton-halogen emission source 104 to output far UV-C light into the first illuminated region when the inferred state of the exception condition is negative may include driving the krypton-halogen emission source 104 according to the time schedule.

Reading the first control data including the schedule for far UV-C illumination, in step 604, may include receiving the control data via a wired communication interface. In another embodiment, reading the first control data including the schedule for far UV-C illumination, in step 604, includes receiving the control data via a wireless communication interface.

The computer method 600 may further include, in step 606, sensing at least one physical parameter corresponding to the first illuminated region. Inferring the state of the exception condition, in step 612, may include comparing a conditional logic state included in the control data to the sensed at least one physical parameter.

The computer method 600 may include, in step 608, reading data corresponding to a state of a second illuminated region. Inferring the state of the exception condition, in step 612, may include comparing the state of the second illuminated region to conditional logic included in the control data. Reading the data corresponding to a state of the second illuminated region, in step 608, may include receiving the data corresponding to the state of the second illuminated region via a communication interface. In one embodiment, receiving the data corresponding to the state of the second illuminated region via a communication interface includes receiving the data corresponding to the state of the second illuminated region from a computing device 116. In another embodiment, receiving the data corresponding to the state of the second illuminated region via a communication interface includes receiving the data corresponding to the state of the second illuminated region from a second electronic controller 108 operatively coupled to a second krypton-halogen emission source 104 disposed in a second housing 109 arranged to output far UV-C light to the second illuminated region. For example, the second illuminated region may be a neighboring illuminated region to the first illuminated region. The second UV-C illuminator controller may transmit the data to the first UV-C illuminator controller responsive at least partially to at least one second sensed physical parameter corresponding to the second region. In an embodiment, the at least one second sensed physical parameter corresponds to presence of at least one person in the second region. The first and second UV-C electronic controllers may cooperate to infer that at least one person is moving from the second region to the first region.

According to embodiments, the method 600 for controlling far UV-C illumination of a region includes, in step 610, reading data corresponding to a state of an electronic device associated with a person in the first illuminated region. Inferring the state of the exception condition, in step 612, may include comparing the state of the electronic device associated with the person in the first illuminated region to conditional logic included in the control data.

The computer method 600 for controlling far UV-C illumination of a region may include sensing at least one physical parameter corresponding to the first illuminated region (in step 606), reading data corresponding to a state of a second illuminated region, in step 608, and/or, in step 610, reading data corresponding to a state of an electronic device associated with a person in the first illuminated region Inferring the state of the exception condition, in step 612, may include comparing, to conditional logic included in the control data, the at least one physical parameter, the state of the second illuminated region, and/or the state of the electronic device.

Inferring the state of the exception condition, in step 612, may include determining that an exception condition exists, in step 614. In this case, driving, with the first electronic controller 108, the krypton-halogen emission source 104 disposed in the first housing 109 to output far UV-C light into the first illuminated region according to the exception condition that exists, as shown in step 620. For example, if the schedule for far UV-C illumination includes outputting longer wave ultraviolet illumination, for example at night to improve disinfection of distant surfaces; and a person is sensed in the illuminated region 106, causing an exception, the electronic controller 108 may stop the krypton-halogen emission source 104 from emitting any ultraviolet light until the person leaves the illuminated region 106. In another example, the electronic controller 108 may reduce the wavelength range or reduce the intensity of light emitted by the krypton-halogen emission source until the person leaves the illuminated region 106.

In an embodiment, the computer method 600 includes, in step 618, transmitting the state of the exception condition corresponding to the first illuminated region via a communication interface to a computing device 116. Step 618 may include transmitting the state of the exception condition corresponding to the first illuminated region via a communication interface to an electronic controller in at least one second ultraviolet illuminator 102a, 102c arranged to output far UV-C light to at least one second illuminated region 106a, 106c.

The computer method 600 may include, while maintaining driving of the krypton-halogen emission source according to the state of the exception condition, looping to again read the first control data (in step 604) and inferring the state of the exception condition (in step 612).

The computer method 600 may include, in step 606, sensing at least one physical parameter corresponding to the first illuminated region 106b, the at least one physical parameter corresponding to a presence or absence of a person in the first illuminated region 106b. Inferring the state of the exception condition, in step 612, may include comparing a conditional logic state included in the control data to the sensed presence or absence of the person in the first illuminated region. Sensing at least one physical parameter corresponding to the first illuminated region with a sensor, in step 606, may include using a sensor configured to sense an occupancy parameter, using an infrared gas sensor configured to sense a backscattered interrogation beam, using a carbon dioxide sensor, using a non-infectious airflow sensor, using a microphone, using a motion detector, using a digital camera, using a digital video recorder, using a LiDAR, and/or using a RADAR.

The method 600 may optionally include illuminating a visible light indicator disposed to be visible from outside the first housing, the visible light indicator being selected to indicate a state of output of the far UV-C illumination from the krypton-halogen emission source. For example, illuminating the visible light indicator may include illuminating a red LED when the krypton-halogen emission source outputs wavelengths longer than 630 or 635 nanometers. In another example, illuminating the visible light indicator includes illuminating a yellow LED when the krypton-halogen emission source outputs wavelengths only within the range of 200 to 230 or 235 nanometers at a high power. In another example, illuminating the visible light indicator includes illuminating a green LED when the krypton-halogen emission source outputs wavelengths only within the range of 200 to 230 or 235 nanometers at a low power and/or when the krypton-halogen emission source is not outputting any far UV-C light.

Driving the krypton-halogen emission source in step 620 may include driving a subset of a plurality of individual krypton-halogen emitters corresponding to the state of the exception condition.

The schedule for far UV-C illumination may include a time period when no humans or animals are expected to be present in the first illuminated region. When the exception condition is negative and the time is within the time period when no humans or animals are present in the first illuminated region, driving the krypton-halogen emission source includes driving a subset of a plurality of individual krypton-halogen emitters, the subset including an individual krypton- halogen emitter to output ultraviolet light including light between 230 or 235 nanometers and 280 nanometers. When the schedule for far UV-C illumination includes a time period when no humans or animals are expected to be present in the first illuminated region, and when the exception condition is negative and the time is within the time period, driving the krypton-halogen emission source may include actuating removal of a filter configured to eliminate passage of ultraviolet wavelengths between 230 or 235 nanometers and 280 nanometers.

According to embodiments, driving the krypton-halogen emission source includes driving the krypton-halogen emission source with pulse width modulated (PWM) electrical energy according to the state of the exception condition and the schedule. Driving the krypton-halogen emission source may include stopping or reducing far UV-C output when the state of the inferred exception condition corresponds to a person being present in the first illuminated region.

Driving the krypton-halogen emission source 104 to output far UV-C light into the first illuminated region may include driving the krypton-halogen emission source to output far UV-C light in a range of 200 nanometers wavelength to 235 nanometers wavelength. For example driving the krypton-halogen emission source 104 to output far UV-C light into the first illuminated region may include driving the krypton-halogen emission source to output far UV-C light in a range of 200 nanometers wavelength to 230 nanometers wavelength.

In the computer method 600, sensing at least one physical parameter corresponding to the first illuminated region in step 606 may include sensing sound with a microphone. Inferring a state of an exception condition in step 612 may include, with the electronic controller 108, performing a Fourier transform on a signal from the microphone to produce a spectral noise signature and comparing the spectral noise signature to a plurality of reference spectral noise signatures held in a non-transitory computer readable memory to obtain at least one best match. The plurality of reference spectral noise signatures may be constructed to correspond to known numbers of persons in the first illuminated region. The electronic controller 108 may be configured to obtain an inferred infectious particle concentration from at least one look-up-table (LUT) corresponding to at least one best matched reference spectral noise signatures.

While various aspects and embodiments have been disclosed herein, other aspects and embodiments are contemplated. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.