Patent Description:
Ultraviolet (UV) light has been found to be an effective disinfectant. Of the various UV wavelengths, <NUM> nanometers (<NUM>) has been found to be particularly promising (effective and relatively safe for humans in moderate doses). Currently, UV lights that emit light of this wavelength are only available as gas-discharge excimer bulbs. These bulbs have longevity challenges and relatively low efficiency (e.g., less than <NUM> percent efficient) so a significant amount of this energy is dissipated as thermal energy. The relatively short lifetime of these bulbs (e.g., in the hundreds of hours) means that they should be replaced relatively frequently. Due to power and weight demands on board aircraft, it is desirable to monitor the status of these excimer bulbs using as little power as possible.

Thus, there is a need in the art for systems and methods for low-power monitoring of these ultraviolet-emitting UV excimer bulbs. <CIT> relates to systems and methods for operating a light system.

The invention is defined by a system for monitoring an excimer bulb according to claim <NUM> and a method for monitoring an excimer bulb according to claim <NUM>. Further embodiments are set out in the dependent claims.

In any of the foregoing embodiments, the controller is further configured to calculate the remaining useful life of the excimer bulb based on at least one of the current temperature of the excimer bulb, a previously-calculated historical temperature of the excimer bulb, the current voltage of the electrical energy converted by the thermoelectric energy harvester, or a previous voltage of the electrical energy converted by the thermoelectric energy harvester.

Any of the foregoing embodiments may further include a memory configured to store historical data corresponding to at least one the previously-calculated historical temperature of the excimer bulb or the previous voltage of the electrical energy converted by the thermoelectric energy harvester, and the controller is further configured to calculate the remaining useful life of the excimer bulb by comparing at least one of the current temperature of the excimer bulb or the current voltage of the electrical energy converted by the thermoelectric energy harvester to the historical data.

Any of the foregoing embodiments may further include a wireless transmitter coupled to the controller and configured to transmit the at least one of the remaining useful life of the excimer bulb or the current temperature of the excimer bulb to a remote device.

In any of the foregoing embodiments, the wireless transmitter is configured to be powered using the electrical energy generated by the thermoelectric energy harvester.

Any of the foregoing embodiments may further include a housing configured to house the thermoelectric energy harvester, the controller, and the wireless transmitter.

In any of the foregoing embodiments, the controller is configured to be powered using the electrical energy generated by the thermoelectric energy harvester.

In any of the foregoing embodiments, the excimer bulb emits ultraviolet light for damaging or destroying pathogens, and the system is configured for use in an aircraft.

In any of the foregoing embodiments, the controller is configured to calculate both of the remaining useful life of the excimer bulb and the current temperature of the excimer bulb.

In any of the foregoing embodiments, the controller is configured to calculate the remaining useful life of the excimer bulb as hours of useful life remaining.

The invention relates to a system for monitoring an excimer bulb. The system includes a thermoelectric energy harvester configured to be located adjacent to the excimer bulb and to convert heat from the excimer bulb into electrical energy having a voltage. The system further includes a controller in electrical communication with the thermoelectric energy harvester and configured to: calculate a current temperature of the excimer bulb based on the voltage of the electrical energy converted by the thermoelectric energy harvester, and calculate a remaining useful life of the excimer bulb based the voltage of the electrical energy converted by the thermoelectric energy harvester.

Any of the foregoing embodiments may further include a wireless transmitter coupled to the controller and configured to transmit at least one of the remaining useful life of the excimer bulb or the current temperature of the excimer bulb to a remote device.

Also disclosed is a method for monitoring an excimer bulb as defined in claim <NUM>. The method includes converting, by a thermoelectric energy harvester, thermal energy received from an adjacent excimer bulb into electrical energy having a voltage. The method further includes calculating, by a controller, a remaining useful life of the excimer bulb based on the voltage of the electrical energy converted by the thermoelectric energy harvester.

In any of the foregoing embodiments, calculating the remaining useful life of the excimer bulb is performed based on at least one of the current temperature of the excimer bulb, a previously-calculated historical temperature of the excimer bulb, or a previous voltage of the electrical energy converted by the thermoelectric energy harvester.

Any of the foregoing embodiments may further include storing, in a memory, historical data corresponding to at least one the previously-calculated historical temperature of the excimer bulb or the previous voltage of the electrical energy converted by the thermoelectric energy harvester, wherein calculating the remaining useful life of the excimer bulb is performed by comparing at least one of the current temperature of the excimer bulb or the current voltage of the electrical energy converted by the thermoelectric energy harvester to the historical data.

Any of the foregoing embodiments may further include transmitting, by a wireless transmitter, the at least one of the remaining useful life of the excimer bulb or the current temperature of the excimer bulb to a remote device.

In any of the foregoing embodiments, the wireless transmitter is powered using the electrical energy generated by the thermoelectric energy harvester.

In any of the foregoing embodiments, the controller is powered using the electrical energy generated by the thermoelectric energy harvester.

In any of the foregoing embodiments, calculating the at least one of the remaining useful life of the excimer bulb or the current temperature of the excimer bulb includes calculating both of the remaining useful life of the excimer bulb and the current temperature of the excimer bulb.

In any of the foregoing embodiments, calculating the remaining useful life of the excimer bulb includes calculating a number of hours of remaining useful life remaining.

The scope of the invention is as defined by the claims.

The detailed description of exemplary embodiments herein makes reference to the accompanying drawings, which show exemplary embodiments by way of illustration. While these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the exemplary embodiments of the disclosure, it should be understood that other embodiments may be realized and that logical changes and adaptations in design and construction may be made in accordance with this disclosure and the teachings herein, within the scope of the claims. Thus, the detailed description herein is presented for purposes of illustration only and not limitation.

Surface shading lines may be used throughout the figures to denote different parts but not necessarily to denote the same or different materials.

The present disclosure is directed to systems and methods for monitoring the status of an ultraviolet (UV)-emitting excimer bulb. The systems and methods may be implemented in an aircraft which has significant weight and power demands. Due to these demands, it is highly desirable to use as little power as possible to monitor the status of these bulbs. In that regard, the present disclosure presents a monitoring device that is self-powering using a thermal-to-electric (thermoelectric) energy harvester between the bulb and its thermal heat sink. The thermoelectric energy harvester powers a controller which may calculate a remaining useful life or a current temperature of the excimer bulb based on the voltage of the energy generated by the energy harvester, and a wireless transmitter that transmits the remaining useful life or the current temperature to an aircraft controller.

The ultraviolet excimer bulbs of the present disclosure may emit far UV-C light. This light may be defined as a germicidal light source having a peak wavelength that is between <NUM> nanometers (<NUM>, <NUM> thousandths of an inch, or mils) and <NUM> (<NUM> mils), between <NUM> (<NUM> mils) and <NUM> (<NUM> mils), or about <NUM> (<NUM> mils). Where used in this context, "about" refers to the referenced value plus or minus <NUM> percent of the referenced value.

UV light of this type may effectively injure, neutralize, or kill pathogens that are both airborne and resting on surfaces. In addition, this light may be readily absorbed by most materials and may be relatively safe for human exposure.

Referring now to <FIG>, a portion of an aircraft lavatory <NUM> may include one or more UV excimer bulb <NUM>. The excimer bulb <NUM> may emit UV light towards a portion of the lavatory <NUM>, as shown by an arrow <NUM>. The lavatory <NUM> may further include a monitoring device <NUM>.

Turning now to <FIG> and <FIG>, the monitoring device <NUM> may be located between the excimer bulb <NUM> and a heat sink <NUM> designed to collect and distribute thermal energy from the excimer bulb <NUM>. Excimer bulbs <NUM> emit a relatively large amount of thermal energy (i.e., heat) compared to other ultraviolet light sources. However, excimer bulbs are currently the only light sources capable of emitting light of certain wavelengths (e.g., <NUM>).

Due to inclusion of the excimer bulb <NUM> and monitoring device <NUM> on board aircraft, it is desirable for the monitoring device <NUM> to use relatively little power. In that regard, the monitoring device <NUM> includes a thermoelectric energy harvester <NUM>. The thermoelectric energy harvester <NUM> is designed to receive a portion of the thermal energy that is output by the excimer bulb <NUM> (hence the thermoelectric energy harvester <NUM> being located between the excimer bulb <NUM> and the heat sink <NUM>) and to convert the received thermal energy into electrical energy.

The monitoring device <NUM> may further include a controller <NUM> and a wireless transmitter <NUM>. The controller <NUM> may include one or more logic devices such as one or more of a central processing unit (CPU), an accelerated processing unit (APU), a digital signal processor (DSP), a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), or the like. In various embodiments, the controller <NUM> may further include any non-transitory memory <NUM> known in the art. The memory <NUM> may store instructions usable by the logic device to perform operations. The memory <NUM> may also or instead store other data as instructed by the controller <NUM> such as historical remaining life values or historical temperatures of the excimer bulb <NUM>.

The wireless transmitter <NUM> may at least one of transmit or receive wireless signals. For example, the wireless transmitter <NUM> may wirelessly communicate via a wireless protocol such as an <NUM>. 11a/b/g/n/ac protocol (e.g., Wi-Fi), a wireless communications protocol using short wavelength UHF radio waves and defined at least in part by IEEE <NUM>. <NUM> (e.g., the BLUETOOTH protocol maintained by Bluetooth Special Interest Group), a wireless communications protocol defined at least in part by IEEE <NUM>. <NUM> (e.g., the ZigBee protocol maintained by the ZigBee alliance), a cellular protocol, an infrared protocol, an optical protocol, a radio frequency identification (RFID) protocol, a near field communications (NFC) protocol, or any other protocol capable of wireless transmissions.

The monitoring device <NUM> may include a housing <NUM>. The housing <NUM> may include a physical structure onto which the other components (i.e., one or more of the energy harvester <NUM>, the controller <NUM>, the memory <NUM>, or the wireless transmitter <NUM>) of the monitoring device <NUM> are affixed. In various embodiments, the other components may be at least one of surrounded by structure of the housing <NUM> or mounted on the housing <NUM> and at least partially exposed to the environment.

The monitoring device <NUM> may include a connector <NUM>. The connector <NUM> may be coupled to the housing <NUM> and may affix the housing <NUM> to a portion of the excimer bulb <NUM> (or to a housing or other retaining structure of the excimer bulb <NUM>). For example, the connector <NUM> may include a snap connector, a strap, a press-fit connector, or any other connector capable of affixing the housing <NUM> to the excimer bulb <NUM>. The connector <NUM> may be designed such that the energy harvester <NUM> is located adjacent to the excimer bulb <NUM> at a constant, known distance <NUM>. The distance <NUM> may be any distance sufficiently small for the energy harvester <NUM> to receive thermal energy from the excimer bulb <NUM>. For example, the distance <NUM> may be between <NUM> inches (<NUM> millimeters, mm) and <NUM> inches (<NUM>), between <NUM> inches (<NUM>) and <NUM> inches (<NUM>), or between <NUM> inch (<NUM>) and <NUM> inches (<NUM>). The distance <NUM> may remain constant regardless of the excimer bulb <NUM> to which the housing <NUM> is affixed.

In response to being affixed to the excimer bulb <NUM>, the energy harvester <NUM> may be directly exposed to the excimer bulb <NUM> such that no structure exists therebetween (i.e., thermal energy from the excimer bulb <NUM> may travel directly to the energy harvester <NUM>). The energy harvester <NUM> may be placed on an opposite side of the excimer bulb <NUM> from which the ultraviolet light is desired (i.e., the energy harvester <NUM> may be located on an opposite side of the excimer bulb <NUM> from the direction indicated by the arrow <NUM>) such that the housing <NUM> and energy harvester <NUM> fail to interfere with desirable operation of the ultraviolet light.

In response to receiving the thermal energy from the excimer bulb <NUM>, the energy harvester <NUM> may generate electrical energy having a voltage. The voltage of the energy generated by the energy harvester <NUM> may be directly related to the temperature of the thermal energy received by the energy harvester <NUM>. In that regard, the voltage may directly correspond to the temperature of the thermal energy. The controller <NUM> may receive the electrical energy from the energy harvester <NUM> and may determine at least one of the current temperature of the excimer bulb <NUM> or a remaining useful life of the excimer bulb <NUM> based on the voltage of the received electrical energy. In various embodiments, the controller <NUM> may calculate the current temperature and the remaining useful life.

In various embodiments, the memory <NUM> may store data received or determined by the controller <NUM>. For example, the memory <NUM> may store historical data such as historical voltages of the electrical energy received by the controller <NUM>, historical calculated temperatures of the excimer bulb <NUM>, or historical remaining useful life of the excimer bulb <NUM>. In that regard, the controller <NUM> may calculate at least one of the remaining useful life of the excimer bulb <NUM> or the current temperature of the excimer bulb <NUM> based on this historical data. For example, the controller <NUM> may compare a current calculated temperature of the excimer bulb <NUM> to a historical calculated temperature of the excimer bulb <NUM> to determine a remaining useful life of the excimer bulb <NUM>. As another example, the controller <NUM> may compare a current received voltage to a historically received voltage to determine the remaining useful life of the excimer bulb <NUM>. In various embodiments, the controller <NUM> may calculate a remaining useful life of the excimer bulb <NUM> as a remaining quantity of hours of useful life of the excimer bulb <NUM>. In various embodiments, the controller <NUM> may calculate a remaining useful life of the excimer bulb <NUM> based on additional data such as a voltage waveform provided to the excimer bulb <NUM>, a current waveform provided to the excimer bulb <NUM>, or the like.

The controller <NUM> may be in electrical communication with the wireless transmitter <NUM>. In that regard, the wireless transmitter <NUM> may transmit data received or calculated by the controller <NUM>. The wireless transmitter <NUM> may be capable of transmitting signals to be received by an aircraft controller <NUM> (which may include a controller responsible for monitoring the status of components of the lavatory <NUM> of <FIG>). For example, the wireless transmitter <NUM> may transmit the current calculated temperature and the remaining useful life of the excimer bulb <NUM> to the aircraft controller <NUM>. In various embodiments, the wireless transmitter <NUM> may also or instead transmit lower-level data such as the detected voltage of the electrical power generated by the energy harvester <NUM>.

As referenced above, it is desirable for the monitoring device <NUM> to draw relatively little power from the aircraft. In that regard, the electrical energy generated by the energy harvester <NUM> may be transmitted to the controller <NUM>, the memory <NUM>, and the wireless transmitter <NUM> and may be used to power the controller <NUM>, the memory <NUM>, and the wireless transmitter <NUM>. In some embodiments, the monitoring device <NUM> may also include one or more energy converter <NUM> capable of converting or otherwise formatting the electrical power generated by the energy harvester <NUM> into electrical power having a voltage, amplitude, and frequency (in the case of alternating current) that is usable by each of the controller <NUM>, the memory <NUM>, and the wireless transmitter <NUM>. In that regard, the monitoring device <NUM> is self-contained and self-powering such that the only wires used in relation to the excimer bulb <NUM> are the wires that provide power to the excimer bulb <NUM>. This reduces the complexity of the lavatory <NUM> of <FIG> as well as the power draw by the system.

Turning now to <FIG>, a flowchart illustrates a method <NUM> for monitoring an excimer bulb. The method <NUM> may be used by a monitoring device similar to the monitoring device <NUM> of <FIG> and <FIG>, and may monitor an excimer bulb such as the excimer bulb <NUM> used in the aircraft lavatory <NUM> of <FIG>. The method <NUM> may begin in block <NUM> where a thermoelectric energy harvester receives thermal energy from an excimer bulb and converts the thermal energy into electrical energy having a voltage.

In block <NUM>, a memory may store historical data such as historical voltages of the electrical energy output by the harvester, historically calculated temperatures of the excimer bulb, or historically calculated remaining useful life of the excimer bulb.

In block <NUM>, a controller may receive the electrical power from the harvester and may also receive historical data from the memory. The controller may then calculate a current temperature of the excimer bulb based on at least one of the current voltage of the electrical power from the harvester or the historical data from the memory.

In block <NUM>, the controller may calculate a remaining useful life of the excimer bulb. For example, the controller may calculate the remaining useful life based on the current voltage of the electrical power and based on the historical data.

In block <NUM>, a wireless transmitter may transmit at least one of the current temperature or the remaining useful life of the excimer bulb to an aircraft controller. As with the monitoring device <NUM> shown in <FIG> and <FIG>, the controller, memory, and wireless transmitter discussed with reference to <FIG> may be entirely powered using the electrical energy output by the thermoelectric energy harvester.

Claim 1:
A system for monitoring an excimer bulb, the system comprising:
a thermoelectric energy harvester (<NUM>) configured to be located adjacent to the excimer bulb (<NUM>) at a constant, known distance (<NUM>), and to convert thermal energy from the excimer bulb (<NUM>) into electrical energy having a current voltage; and
a controller (<NUM>) in electrical communication with the thermoelectric energy harvester and configured to calculate a remaining useful life of the excimer bulb based on the current voltage of the electrical energy converted by the thermoelectric energy harvester.