Pulsed red-NIR light for supporting eye health

Abstract

A lighting module for connecting to a luminaire. The lighting module comprises one or more light sources configured to output a light pulse in a predetermined wavelength band and a controller for driving the one or more light sources to output the light pulse. When connected to the luminaire, the lighting module reduces the intensity of light output by the luminaire during the light pulse from a first intensity to a second, lower intensity.

Description

[0001] Pulsed RED-NIR light for supporting eye health

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to the field of lighting, and in particular to a lighting system for providing radiation capable of triggering biofunctions in humans.

[0004] BACKGROUND OF THE INVENTION

[0005] Recent studies have shown that light, particularly red and near-infrared (NIR) light, plays an important role in the development of our eyes as a child and in maintaining good eye health as we age. Low-level red-light therapy, requiring a patient / user to stare into a device that shines red light into their eyes for several minutes, has been demonstrated to slow down the progression of myopia (short-sightedness) and age-related macular degeneration (AMD). The suspected mechanism is a photo-biomodulation response through the stimulation of cytochrome C oxidase, leading to the synthesis of ATP by mitochondria in the cells of our eyes.

[0006] In our modern lifestyles, increased time spent indoors and the use of artificial light sources that lack red and near-infrared (NIR) wavelengths has meant a severe reduction in the amount of red and NIR light reaching our eyes, leading to a general decline over time of the population’s eye health.

[0007] Ideally, every person would have a device that they use daily to receive a sufficient dose of red / NIR light. However, not everyone may have the time or discipline to maintain such a self-treatment.

[0008] There is therefore a desire for a device that may be implemented into already existing lighting systems for providing light that can trigger a photo-biomodulation response in humans. In this way, providing the dose of red / NIR light during a person’s daily life, such that they do not need to change their habits, becomes a prevent! ve / supportive strategy for maintaining eye health. SUMMARY OF THE INVENTION

[0009] The invention is defined by the claims.

[0010] According to examples in accordance with an aspect of the invention, there is provided a lighting module configured to connect to a luminaire, wherein the luminaire is configured to output light in a visible wavelength band. The lighting module comprises one or more light sources configured to output a light pulse in a predetermined wavelength band for irradiating an environment. The lighting module further comprises a controller configured to drive the one or more light sources to output the light pulse, and a connector for connecting the lighting module to the luminaire. When connected to the luminaire, the lighting module is configured to control the luminaire. The luminaire is configured to be controlled by the lighting module when the lighting module is connected to the luminaire. Specifically the lighting module is configured to control the luminaire to reduce the intensity of the light output by the luminaire during the light pulse from a first intensity to a second, lower intensity.

[0011] The present disclosure provides a lighting module comprising one or more light sources, the one or more light sources being configured to emit light in a predetermined wavelength band when driven by a controller of the lighting module. The light emitted by the one or more light sources is output as a “light pulse”. More specifically, the controller drives the one or more light sources to output light in the predetermined wavelength band for a specific or limited duration of time, i.e., a pulse. In this way, the lighting module irradiates a nearby environment with a pulse of light of the predetermined wavelength band.

[0012] The lighting module is also configured to be connected, via an interface, to a luminaire. In this context, the luminaire emits light in a visible wavelength band (e.g., white light) for the purposes of illuminating the (same) environment.

[0013] When connected to the luminaire, the lighting module is able to control the intensity of light output by the luminaire. More specifically, the controller of the lighting module is configured to reduce the intensity of light emitted by the luminaire when the one or more light sources of the lighting module are outputting light in the predetermined wavelength band, i.e., during the light pulse. In this way, depending on the color of light given by the predetermined wavelength band, and how much the intensity of light emitted by the luminaire is reduced by, the light pulse (with or without the light from the luminaire) may result in a perceived change in the illumination of the environment. In the context of the present disclosure, the interface may be configured to provide a physical or mechanical connection between the lighting module and the luminaire. In particular, the interface may, in some embodiments, permit the lighting module to be selectively attached and detached from the luminaire. In this way, the lighting module may be detachable (with respect to the luminaire).

[0014] Thus, the interface may form an electromechanical interface, such that the lighting module may effectively function as an add-on or supplementary component that is not part of the original luminaire.

[0015] In some examples, the interface may form a non-physical connection, e.g., a wireless connection, with the luminaire, e.g., via a wireless network, via Bluetooth, etc., when the luminaire is similarly capable of wireless connect! on / communi cation. Thus, the interface may be a wireless transceiver for establishing wireless communications with the luminaire.

[0016] Desirably, the predetermined wavelength band substantially contains red and / or near-infrared (NIR) parts of the electromagnetic spectrum. In this way, the light pulse may trigger a photo-biomodulation response in a subject (e.g., an observer) or, more specifically, in the subject’s eyes, supporting the subject’s ocular health.

[0017] It has been recognized that the above invention can be implemented into a general lighting system to provide a prevent! ve / supportive treatment for a subject’s eye health, while also providing additional contextual information through the perceived change in the illumination of the environment.

[0018] For example, when lighting modules are connected to luminaires of a school lighting system, intermittent light pulses may be used to trigger a photo-biomodulation response in school children to assist with eye development. Additionally, the light pulses may (also) be timed to indicate an event, e.g., the start and / or end of a class, or activated in the school hallways as school children move between classrooms, indicative of a transitionary period while also triggering a photo-biomodulation response in the eyes of the nearby school children.

[0019] In some examples, the predetermined wavelength band may be between the range of 620 nm to 850 nm. In other words, the predetermined wavelength band contains only red and NIR parts of the electromagnetic spectrum. In some examples, the light pulse may have a duration of at least 2 minutes. This may be to ensure a subject, irradiated by the light pulse, will receive a sufficient dose of light from the predetermined wavelength band to trigger a photo-biomodulation response.

[0020] In some examples, the second intensity (of the luminaire) may be no more than 50% of the first intensity. Furthermore, the lighting module may be configured to stop the luminaire outputting light during the light pulse. In this way, during the light pulse, the subject will perceive a visual change in the illumination of the environment. This may include a change in the color of illumination, e.g., a change from white light to colored light.

[0021] In some examples, the controller may be configured to drive the one or more light sources to output the light pulse one or more times per day. Additionally, or alternatively, the controller may be configured to drive the one or more light sources to output the light pulse at least once per hour. Furthermore, the controller may be configured to drive the one or more light sources to output the light pulse no more than two times per hour. In this way, the minimum and / or the maximum exposure (of the predetermined wavelength band) to the subject can be controlled.

[0022] In some examples, the controller may be configured to drive the one or more light sources to output the light pulse when one or more predefined conditions are met.

[0023] A predefined condition may include: a time-of-day (e.g., 10:00 AM), a detection of sound, a detection of proximity, a manual input, or any combination thereof. The choice of predefined condition may be dependent on the setting in which the lighting module is used and of the activities a subject may perform in said setting.

[0024] The lighting module may comprise, for instance, one or more input modules configured to obtain information on each predefined condition, i.e., obtain one or more input parameters. The condition obtaining module(s) may provide the obtained information or input parameters to the controller that processes said information or input parameters to determine whether or not the predefined condition(s) has / have been met. In other words, the controller of the lighting module receives (from the input module(s)) one or more input parameters from which the controller makes the decision as to whether or not the one or more predefined conditions are met and therefore whether or not to emit the light pulse.

[0025] Thus, the lighting module may further comprise one or more input modules configured to obtain one or more input parameters that indicate or identify whether or not the one or more predetermined conditions are met. The controller of the lighting module may receive the one or more input parameters from the one or more input modules and process the received one or more input parameters to determine whether or not the one or more predefined conditions are met.

[0026] Suitable examples of input modules, for obtaining relevant information pertinent to the predefined condition(s), will be readily apparent to the skilled person. These may include, but are not limited to, clocks / timers, proximity sensors, audio sensors, and ambient light sensors.

[0027] In some examples, the controller may be configured to operate in either a first operating mode or a second operating mode, wherein a maximum duration of the light pulse is longer in the second operating mode than in the first operating mode. A first and a second operating mode may represent an awake and a sleep operating mode, respectively, referring to a subject being either awake or asleep. Accordingly, in the awake operating mode, the maximum duration of the light pulse may be limited to prevent overexpose to the subject’s eyes.

[0028] According to the above example, the controller may be configured to operate in the first operating mode in response to one or more first predetermined conditions being satisfied and operate in the second operating mode in response to one or more second predetermined conditions being satisfied. In other words, the controller may change operating mode in response to one or more conditions being satisfied. The operating mode may change, for example, at a particular time-of-day, or in response to a manual input, e.g., the subject indicating that they are going to sleep.

[0029] In some examples, the one or more light sources may be further configured to output a further light in a further visible wavelength band, wherein the further visible wavelength band includes light in a wavelength band outside of the predetermined wavelength band. In this way, the lighting module may act as a stand-alone lighting system capable of, for example, also providing white light next to the red / NIR light. In other words, although capable of connecting to a luminaire, the lighting module does not require a luminaire to illuminate the environment with white light.

[0030] According to the above example, the controller may be configured to reduce the intensity of the further light during the light pulse from a further first intensity to a further second, lower intensity. For example, the further second intensity may be no more than 50% of the further first intensity of the further light. Furthermore, the controller may be configured to stop the one or more light sources outputting the further light during the light pulse.

[0031] The present disclosure also provides a luminaire adapted to be connected to a lighting module as described above. The luminaire comprising one or more luminaire light sources configured to output light in a visible wavelength band for irradiating an environment, a controller configured to drive the one or more luminaire light sources to output the light in the visible wavelength band, and a connector for connecting the luminaire to the lighting module. When connected to the lighting module, the luminaire is configured to be controlled by the lighting module to reduce an intensity of the light output by the luminaire from a first intensity to a second, lower intensity during the light pulse from the lighting module.

[0032] The present disclosure also provides a kit of parts comprising a lighting module as described above and a luminaire as described above.

[0033] The present disclosure also provides a method of irradiating an environment, the method comprising: (a) providing a lighting module comprising one or more light sources configured to output a light pulse in a predetermined wavelength band for irradiating an environment and intended to trigger a photo-biomodulation response in a subject positioned or located within the environment, and a controller configured to drive the one or more light sources to output the light pulse; (b) providing a luminaire comprising one or more luminaire light sources configured to output a light in a visible wavelength band for irradiating an environment, and a controller configured to drive the one or more luminaire light sources to output the light in the visible wavelength band; (c) connecting the lighting module to the luminaire; and (d) controlling, by a controller of the lighting module, the luminaire to reduce an intensity of the light output by the luminaire from a first intensity to a second, lower intensity during a light pulse from the light module

[0034] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment s) described hereinafter.

[0035] BRIEF DESCRIPTION OF THE DRAWINGS

[0036] For a better understanding of the invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings, in which: Figure 1 illustrates a simplified schematic of a lighting module;

[0037] Figure 2 is a graph illustrating an example lighting routine for a lighting module; and

[0038] Figure 3 illustrates another simplified schematic of a lighting module.

[0039] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] The invention will be described with reference to the Figures.

[0041] It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the apparatus, systems and methods, are intended for purposes of illustration only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the apparatus, systems and methods of the present invention will become better understood from the following description, appended claims, and accompanying drawings. It should be understood that the Figures are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the Figures to indicate the same or similar parts.

[0042] The invention provides a lighting module configured to connect to, and control the light output of, a luminaire. The lighting module comprises one or more light sources, configured to emit a light pulse in a predetermined wavelength band, and a controller for driving the one or more light sources to emit the light pulse. The lighting module further comprises an interface for connecting the lighting module to the luminaire. Such an interface may be a physical / electromechanical connector to make a wired (i.e., physical) connection with the luminaire or a wireless transceiver for wireless (i.e., nonphysical) communication with the luminaire. When connected to the luminaire, the lighting module controls the luminaire such that, when the one or more light sources is emitting the light pulse, the intensity of light output by the luminaire is reduced, i.e., compared to when the one or more light sources is not emitting the light pulse.

[0043] Figure 1 illustrates a simplified block schematic of a lighting module 100.

[0044] The lighting module 100 comprises one or more light sources 110 able to output light in a predetermined wavelength band. The one or more light sources 110 output light (in the predetermined wavelength band) when driven by a driving signal, e.g., an electrical current, such that, when driven by the driving signal, an environment in the vicinity of the lighting module 100 is irradiated by light of the predetermined wavelength band. Each light source of the one or more light sources 110 may comprise an LED, or a laser diode, or any further solid-state device adapted to emit light within a desired wavelength band, e.g., the predetermined wavelength band.

[0045] The lighting module 100 further comprises a controller 120 in communication with the one or more light sources 110. The controller 120 is configured to drive the one or more light sources 110 to output light, i.e., by providing a driving signal, such as an electrical current, to the one or more light sources. In other words, the one or more light sources 110 only emit light when driven by the controller 120.

[0046] The controller 120 is configured to drive the one or more light sources 110 to output light in the predetermined wavelength band as a light pulse 150. More specifically, the controller 120 is configured to drive the one or more light sources 110 for a specific or a limited duration of time, such that light is emitted (by the one or more light sources) for said duration of time. The controller 120 therefore does not continuously drive the one or more light sources 110, but instead drives the one or more light sources 110 for discrete periods of time. In this way, light (in the predetermined wavelength band) is output by the one or more light sources 110 in the form of pulses.

[0047] The controller 120 may be configured to drive, or more specifically to start driving, the one or more light sources 110 to output the light pulse 150 when one or more predefined conditions are met, examples of which will be discussed later.

[0048] The lighting module 100 further comprises an interface 130 for connecting the lighting module 100 to a luminaire 170. The interface 130 at least permits the lighting module 100 to communicate with the luminaire 170 (e.g., via signals generated from the controller 120) such that the lighting module 100 is able to control the intensity of light output by the luminaire 170. In this context, the luminaire 170 outputs light in a visible wavelength band (e.g., white light) for the intention of illuminating an environment such that the visibility of the environment, and of objects within the environment, is enhanced.

[0049] The interface 130 may be an adapter that permits the lighting module 100 to be “plugged-in” to a corresponding socket / port of the luminaire 170. Such an adaptor may result in the lighting module 100 being rigidly connected to the luminaire 170 (e.g., in the case of a plug adapter) or flexibly connected to the luminaire 170 (e.g., in the case of a wire adaptor). Alternatively, the interface 130 may be a network device that permits the controller 130 to communicate with the luminaire 170 over a wireless network. Different interface embodiments may be desirable depending on a preferred positioning of the lighting module with respect to the luminaire.

[0050] The interface 130 may therefore be configured to provide detachable connection between the lighting module and the luminaire. Thus, the lighting module 100 may be (physically) detached from the luminaire when disconnected therefrom and (physically) attached to the luminaire when connected thereto.

[0051] In this way, the interface 130 may function as a detachable electromechanical interface between the lighting module and the luminaire, such that the lighting module 100 is able to function as a (removable) supplementary component of the luminaire to provide additional functionality to the luminaire and control of the luminaire.

[0052] In other examples, the interface 130 may be configured to make a wireless connection with the luminaire. Thus, the connector 130 may, for instance, comprise a wireless communication module configured to establish and control wireless communications with the luminaire using one or more wireless communication protocols.

[0053] Suitable wireless communication protocols that may be used to communicate with the luminaire include an infrared link, Zigbee, Bluetooth, a wireless local area network protocol such as in accordance with the IEEE 802.11 standards and so on. Other formats, including proprietary formats, will be readily apparent to the person skilled in the art.

[0054] When connected to the luminaire 170, the lighting module 100 is configured to control the luminaire 170 and the luminaire 170 is adapted to be controlled by the lighting module 100 when the lighting module 100 is connected to the luminaire 170. More specifically, the lighting module 100 controls the luminaire 170 such that the intensity of light output by the luminaire 170 is reduced from a first intensity to a second, lower intensity during the light pulse 150. The lighting module 100 may control the luminaire 170 by transmitting signals (e.g., via a physical or wireless connection) to the luminaire 170.

[0055] For example, the controller 120 of the lighting module 100 may generate a signal (e.g., an electrical signal, a wireless signal, etc.) that is sent to the luminaire 170, via the interface 130. The luminaire 170 may comprise a similar controller that is able to process the signal and perform a requested action as indicated by the signal, e.g., dimming of the luminaire output intensity from the first intensity to the second intensity. As another example, a separate controller (not shown) of the lighting module may generate the signal that is sent to the luminaire, e.g., via the interface. This separate controller and the controller 120 may form part of a same controller system of the lighting module.

[0056] As another example, the controller of the lighting module may directly control the operation of the luminaire, e.g., override a signal provided by a controller of the luminaire.

[0057] The lighting module 100 therefore modulates the illumination of the environment (during the light pulse) through a combination of the reduced light intensity from the luminaire 170 and the addition of the light pulse 150. This modulation may result in a perceived (i.e., noticeable by an observer) change in the illumination of the environment. For example, an observer may observe a change in color of the illumination during the light pulse, when the predetermined wavelength band is characterized by a visible light color substantially different to the color of the visible wavelength band of the luminaire.

[0058] The predetermined wavelength band preferably contains wavelengths of light that, when absorbed by a subject, trigger a photo-biomodulation response in the subject. More specifically, the predetermined wavelength band preferably contains red and / or near infrared (NIR) wavelengths of light for triggering a photo-biomodulation response in a subject’s eyes. In some examples, the predetermined wavelength band may be a wavelength band within the range of from 620 nm to 850 nm, corresponding to purely red and / or NIR light.

[0059] The lighting module 100, according to the above, therefore provides a light pulse 150 of the predetermined wavelength band to an environment, intended to trigger a photo-biomodulation response in (the eyes of) a subject positioned or located within the environment.

[0060] Figure 2 shows a graph illustrating an example lighting routine for a lighting module, according to the lighting module 100 of Figure 1, when connected to a luminaire. More specifically, Figure 2 illustrates the intensity of light I, as a function of time t, emitted by the one or more light sources of the lighting module and the luminaire over a first time period Tpi and a second time period Tp2.

[0061] Curve 210 represents the intensity of light emitted by the one or more light sources in the predetermined wavelength band and curve 220 represents the intensity of light emitted by the luminaire in the visible wavelength band. At the start of both the first time period Tpi and the second time period Tp2, the luminaire is emitting light at a first intensity Io and the one or more light sources are not emitting light, i.e., the one or more light sources are not being driven by the controller. This may be considered as a “standard” or a “normal” operating mode, in which the luminaire is emitting light at a standard intensity (i.e., how the luminaire would function if the lighting module was not connected to it) and the lighting module is not emitting light.

[0062] In this context, the first intensity Io may be a discrete intensity output of the luminaire, i.e., a specific intensity (of a potential plurality of exact intensities) that the luminaire can output light at while in the normal operating mode. For example, the first intensity Io may be the only intensity the luminaire can output light at while in the normal operating mode.

[0063] Alternatively, the first intensity Io may be any intensity between a minimum intensity and a maximum intensity of the luminaire, e.g., as allowed by a dimming function of the luminaire (e.g., a user-controllable dimmer switch).

[0064] Preferably, however, the first intensity Io will be an output intensity of the luminaire required to adequately illuminate an environment, such that a subject can adequately (or comfortably) perceive the environment and / or objects within the environment.

[0065] At a particular point in time during the first time period Tpi and the second time period Tp2, the controller begins to drive the one or more light sources to emit the light pulse, seen as an increase in curve 210. Simultaneously, the lighting module communicates to the luminaire, via the interface, to reduce the intensity of light output by the luminaire from the first intensity Io to a second, lower intensity, seen as a decrease in the curve 220.

[0066] In some examples, the second intensity (of light output by the luminaire) may be no more than 50% of the first intensity Io. In other, more preferable examples, the second intensity may be zero. In other words, during the light pulse, the lighting module stops the luminaire outputting light. In this way (during the light pulse) the light illuminating the environment is in the predetermined wavelength band.

[0067] The controller continues to drive the one or more light sources to emit the light pulse for a duration tp, defined as the pulse duration. In the first time period Tpi, the light pulse has a first pulse duration tpi. In the second time period Tp2, the light pulse has a second pulse duration tP2. While the first pulse duration tpiand the second pulse duration tP2 have been depicted in figure 2 as being substantially the same, this need not be the case and the first pulse duration tpiand the second pulse duration tP2 may be substantially different. Possible factors that may affect the pulse duration tpwill be discussed later.

[0068] In some examples, the pulse duration tpmay be at least 2 minutes. A minimum pulse duration may be set depending on parameters such as a brightness of the one or more light sources and a position of the lighting module (which may affect the distance between the one or more light sources and an intended subject), in addition to an intended exposure / dosage of the illuminance received by a subject.

[0069] Once the pulse duration tphas passed, the controller may stop driving the one or more light sources (i.e., the one or more light sources stop outputting light) seen in Figure 2 as the curve 210 falling to zero. Simultaneously, the luminaire returns to the normal operating mode and curve 220 rises back to the first intensity Io (or other intensity, e.g., a user-defined intensity).

[0070] Alternatively, after the pulse duration tphas passed, the controller may continue to drive the one or more light sources but at a reduced intensity, i.e., a magnitude of the driving signal that is less after the light pulse compared to during the light pulse.

[0071] Accordingly, in some examples, the one or more light sources, driven by the reduced driving signal, may continue to emit light in the predetermined wavelength band after the light pulse, but at a reduced intensity compared to during the light pulse. The reduced intensity may be, at most, 50% of the intensity of the predetermined wavelength band during the light pulse, but preferably less than 50%, e.g., less than 25%, e.g., less than 10%.

[0072] The lighting module may be configured to (continue to) output light in the predetermined wavelength band (at the reduced intensity) after (or otherwise not during) the light pulse to tune a perceived color “temperature” of light illuminating the environment. For example, the light illuminating the environment may be perceived as a “warm” white color when the predetermined wavelength band, containing red light, output by the one or more light sources is combined with white light from the luminaire. The perceived color temperature may be tuned by adjusting the intensity of the predetermined wavelength band output by the one or more light sources when the one or more light sources are not outputting the light pulse, i.e., the reduced intensity. For example, the reduced intensity may be user adjustable to allow a user-preferable color temperature to be set.

[0073] In other examples, though being driven by the reduced driving signal, the one or more light sources may stop outputting light (after the light pulse) due to the magnitude of the reduced driving signal being below a required threshold for emission of light, e.g., a threshold voltage for an LED.

[0074] Figure 2 therefore demonstrates two instances of the one or more light sources outputting the light pulse.

[0075] In some scenarios, the first time period Tpi and the second time period Tp2 may occur during the same day. Correspondingly, the one or more light sources may emit the light pulse multiple times per day, i.e., during the first time period Tpi and the second time period Tp2. Put another way, the controller may drive the one or more light sources to emit the light pulse multiple times per day.

[0076] According to the above example, the controller may be configured to drive the one or more light sources to output the light pulse a minimum, a maximum, and / or a specific number of times per day.

[0077] For example, the controller may be configured to drive the one or more light sources to output the light pulse one or more times per day, i.e., at least once per day. This may be desired when the light pulse is intended to provide a daily dosage of the predetermined wavelength band to a subject, and thus the light pulse should be emitted at least once per day.

[0078] In another example, the controller may be configured to drive the one or more light sources to output the light pulse at least once per hour. Furthermore, the controller may also be configured to drive the one or more light sources to output the light pulse no more than two times per hour. A minimum and a maximum number of pulses within a time period may be set to control the dosage of the predetermined wavelength band to a subject, e.g., to ensure a subject receives a minimum dosage to achieve a health benefit but also to limit the maximum dosage to prevent adverse health effects from overexposure to the predetermined wavelength band.

[0079] It has been recognized that the lighting module, according to the above examples, may be added to or used in a general lighting system to support the health of a subject. For example, when the predetermined wavelength band contains red and / or NIR light, the lighting module may be added to or used in a lighting system to provide a lighting routine that supports the eye health of a subject, e.g., by helping the development of the eyes in children and / or by preventing macular degeneration in older adults.

[0080] It has been further recognized that, in order to trigger a desired photobiomodulation response in a subject, the subject must receive a (minimum) desired dosage of the predetermined wavelength band. Accordingly, the intensity of the light pulse and / or output power of the one or more light sources should desirably be set to achieve the desired dosage delivered to the subject.

[0081] For example, when desiring to trigger a photo-biomodulation response in the eyes of a subject, it has been determined that it is desirable if the subject receives (at the eyes) an annual dosage of 25-250 J / cm2of red / NIR light, i.e., an annual energy density delivered to the eyes of the subject. Assuming the subject receives the light pulse every day (e.g., as part of a daily lighting routine), this can be equated as a daily dosage of approximately 0.068-0.68 J / cm2of red / NIR light. Depending on the characteristics of the lighting routine (e.g., frequency and duration of the light pulse), a desired intensity of the light pulse can be determined that provides a dosage within the described ranges.

[0082] For example, assuming a desired daily dosage of 0.25 J / cm2, and that the subject receives the light pulse 10 times per day (e.g., once every hour over a 10 hour period), it is desirable that each light pulse delivers 0.025 J / cm2to the subject. Further assuming a minimum light pulse duration of 2 minutes, it is therefore desirable if the subject is exposed to a light pulse intensity of 0.00021 W / cm2, or 2.1 W / m2, in order to receive the desired dosage of red / NIR light.

[0083] Evidently, the desired light pulse intensity will be heavily dependent on how often, and for how long, the subject is exposed to the light pulse, or in other words the total exposure time of the subject to the light pulse over the course of a day. For instance, a subject may receive the same daily dosage as described above from a lower light pulse intensity when exposed to the light pulse for a longer period of time. Additionally, the exact intensity of light the subject receives from the one or more light sources will be dependent on the power output of the one or more light sources, the distance of the one or more light sources from the subject, and the orientation of the one or more light sources relative to the subject. For example, a lighting module added to a luminaire installed on a ceiling may primarily emit the light pulse downwards onto a horizontal plane. This will result in less light being absorbed by the eyes of the subject than for a lighting module emitting light onto a vertical plane, i.e., directly into the eyes of the subject.

[0084] The output power of the one or more light sources for achieving a desired light pulse intensity, and therefore a desired dosage, will hence depend on the relative positioning of the lighting module compared to the subject and the characteristics of the lighting routine performed by the lighting module.

[0085] In some examples, a desired output power of the one or more light sources (when outputting the light pulse) may be determined through commissioning / calibration of the lighting module, e.g., when the lighting module is integrated into a lighting system. This may include, for example, using a light sensor to measure / monitor the intensity of the light pulse within a certain distance of the lighting module (the distance being representative of an expected distance of a subject from the lighting module) while adjusting the output power (i.e., brightness) of the one or more light sources. The output power may thus be set according to the output power desired to achieve a (measured) desired intensity (for delivering a daily dosage to a subject) as measured by the light sensor.

[0086] The lighting module may be added to or used in different settings to target different populations, including, but not limited to, in homes (e.g., in bathrooms, in bedrooms, etc.) to target a general population, in nurseries and / or schools to target (young) children, and in care homes to target elderly adults.

[0087] Additionally, the lighting module may be configured to emit the light pulse at a particular point in time to coincide with an activity or the start (or end) of an activity related to the setting in which the lighting module is used, for example the start (or end) of a class in a school. The light pulse may therefore be used, in addition to providing a supportive treatment, to provide contextual information to a subject through a perceived change in the illumination of the environment.

[0088] According to the above, and as mentioned previously, it may therefore be desirable for the controller to be configured to drive the one or more light sources to output the light pulse when one or more predefined conditions are met. Figure 3 illustrates a simplified block schematic of a lighting module 300 for which this may be achieved. More specifically, the controller 120 of the lighting module 300 receives one or more input parameters, provided by a respective input module, from which the controller 120 makes the decision as to whether or not to emit the light pulse 150. One example of an input module is a clock 311, configured to provide a (current) time to the controller 120. The controller 120 may be configured to drive the one or more light sources 110 to output the light pulse 150 at predefined points of the day and / or for predefined periods of the day, e.g., according to a schedule. This schedule may correspond to, for example, a schedule for a school (e.g., start times and durations of classes) or a schedule for a care home (e.g., start times and durations of group sessions). Accordingly, the controller 120 may be configured to drive the one or more light sources 110 to output the light pulse 150 to indicate the start and / or end of a scheduled activity or to indicate a “transit period” between activities (e.g., students moving between classes).

[0089] A schedule, to indicate at what times the controller 120 should drive the one or more light sources 110, may be programmed into the controller 120. Alternatively, the controller 120 may access the schedule from a memory 312, which provides another example of an input module.

[0090] The memory 312 may provide a control scheme (e.g., a schedule) to the controller 120, from which the controller 120 decides when to drive the one or more light sources 110. The memory 312 may also collect and store information regarding the number of light pulses 150 emitted by the one or more light sources 110 over a period of time (e.g., a day) and / or the duration of each light pulse 150. This may be used to keep track of and limit the total exposure of a subject to the predetermined wavelength band, e.g., by stopping the controller 120 driving the one or more light sources 110 once an exposure limit, e.g., a predetermined dose, has been reached.

[0091] According to the above, the controller 120 may therefore utilize a combination of input parameters provided by a combination of one or more input modules (e.g., a current time from the clock 311 and a schedule from the memory 312) to decide whether or not the drive the one or more light sources 110 to output the light pulse 150.

[0092] Another example of an input module is a proximity sensor 313 configured to detect the presence or absence of a subject within the vicinity of the lighting module 300. Accordingly, the controller 120 may be configured to drive the one or more light sources 110 to emit the light pulse 150 in response to the determined presence or absence of a subj ect.

[0093] For example, the controller 120 may be configured to only drive the one or more light sources 110 when the proximity sensor 313 detects the presence of a subject, thus preventing emission of the light pulse 150 in the absence of a subject. This therefore avoids the case of the light pulse 150 being emitted when there is no one in the vicinity of the lighting module 300 to receive the light pulse. This can be more energy efficient. In a specific example, the presence detection may be used as an additional condition to output the light pulse, for example, by either allowing or preventing a timed or scheduled output as described above.

[0094] Another example of an input module is an audio sensor 314 configured to detect the presence or absence of sound in the vicinity of the lighting module 300. Accordingly, the controller 120 may be configured to only drive the one or more light sources 110 to emit the light pulse 150 in response to the determined presence or absence of sound.

[0095] As a possible example, when the lighting module 300 is situated inside a bathroom (e.g., when connected to a bathroom light such as a mirror light) the audio sensor 314 may detect the sound of an electric toothbrush and trigger the controller 120 to drive the one or more light sources 110 to output the light pulse 150, i.e., the controller 120 is responsive to the presence of sound detected by the audio sensor 314. In such an example, the lighting module 300 is thus configured to provide the light pulse 150 to a subject twice daily when the subject brushes their teeth. Furthermore, the duration of the light pulse may be timed to indicate a preferential tooth brushing duration e.g., two minutes.

[0096] Another example of an input module is a counter 315 configured to record the number of times over a period of time (e.g., a day) the one or more light sources 110 emit the light pulse 150. The counter 315 may record an instance of a light pulse, for example, by receiving an electrical signal (e.g., from the controller 120). Alternatively, the counter 315 may comprise a light detector configured to detect light in the predetermined wavelength band. The counter 315 may therefore record an instance of a light pulse through detection of light of the predetermined wavelength, i.e., detection of the light pulse.

[0097] The counter 315 may function similar to an aspect of the memory 312 for limiting the exposure of the predetermined wavelength band to a subject. More specifically, the counter 315 may be programmed with a limit for the number of times the light pulse 150 may be emitted over a period of time. Upon reaching the limit, the counter 315 may be configured to prevent the controller 120 driving the one or more light sources 110 to emit the light pulse 150, thereby overriding the inputs from other input modules. Yet another example of an input module is a manual input interface 316. The manual input interface 316 may comprise, for example, a button or a switch, arranged on an external portion of the lighting module 300, such that the manual input interface 316 is accessible to a subject. As another example, the manual input interface may be configured to communicate, e.g., wirelessly, with a remote device (e.g., a remote control) for receiving a user input from an individual. When acted on by a subject, the manual input 316 may send a signal to the controller 120 to start (or stop) driving the one or more light sources 110. A subject may act on the manual input 316 to indicate to the controller 120 the start (or end) of an activity during which the light pulse 150 is to be emitted (or not emitting), e.g., during tooth brushing, when the subject is going to sleep, etc.

[0098] The controller 120 may be further configured to function in different operating modes and to provide different desired characteristics of the light pulse 150. Such characteristics of the light pulse 150 may include, for example, the minimum, the maximum and / or the specific duration of the light pulse and / or the light pulse intensity.

[0099] As one possible example, the controller may function in either a first operating mode, in which the light pulse 150 has a first maximum duration, or a second operating mode, in which the light pulse 150 has a second, longer maximum duration. In other words, the maximum duration of the light pulse 150 is longer in the second operating mode than in the first operating mode.

[0100] In the above example, the first operating mode and the second operating mode may correspond with an “awake” or a “day” operating mode and a “sleep” or a “night” operating mode, respectively. More specifically, the first operating mode is intended to be used when a subject is awake, and the second operating mode is intended for when the subject is asleep.

[0101] It has been recognized that, when asleep (assuming their eyelids are closed), a subject will receive a lower intensity of light to their eyes due to a portion of the light being absorbed by the eyelids. Accordingly, when aiming to trigger a photo-biomodulation response in a subject’s eyes, the subject may receive a pulse of light for longer when asleep, as compared to awake, without overexposing the subject.

[0102] When exposing a subject with the light pulse 150 when the subject is asleep, it may therefore be desirable for the controller 120 to operate in the second operating mode so as to provide a (potentially) longer pulse of the predetermined wavelength band to the subject.

[0103] Additionally, the second operating mode may also correspond with a reduced light pulse intensity (compared to the first operating mode) to better control the exposure of the subject to the predetermined wavelength band to the subject. This may be useful in cases where the subject sleeps with the eyes (partially) open.

[0104] In general, both a duration of the light pulse and an intensity of the light pulse may be used, either individually or in combination, to control an exposure to the predetermined wavelength band. This is independent of operating the lighting module in a particular operating mode. In other words, both the duration and intensity of the light pulse may be controlled regardless of in which operating mode the lighting module is operating.

[0105] In order to support different operating modes, the lighting module 300 may further comprise a mode module 330 for indicating to the controller 120 which operating mode to function in. The mode module 330 may be configured to indicate to the controller 120 to change operating mode in response to one or more predetermined conditions being satisfied.

[0106] For example, when a first operating mode and a second operating mode are intended to be used when a subject is awake and asleep, respectively, the mode module 330 may indicate to the controller 120 to change from the first operating mode to the second operating mode at a particular time-of-day (e.g., 11 :00 PM) or in response to a manual input, e.g., from the subject in response to them going to sleep.

[0107] Additionally, as another example, the mode module 330 may indicate to the controller 120 to change from the second operating mode to the first operating mode at a particular time-of-day (e.g., 07:00 AM) or in response to a detection of motion, e.g., the subject waking up.

[0108] In other words, the controller 120 may be configured to operate in the first operating mode (from an indication from the mode module 330) in response to one or more first predetermined conditions being satisfied, and operate in the second operating mode (from an indication from the mode module 330) in response to one or more second predetermined conditions being satisfied.

[0109] The mode module 330 may comprise a number of sensors (e.g., a clock, a proximity / motion sensor, etc.) in order to determine whether the one or more predetermined conditions have been satisfied. Alternatively, the mode module 330 may be able to receive input parameters from the one or more input modules.

[0110] So far, the lighting module has only been described as being connected to a luminaire. In some examples, however, the lighting module may be able to function without being connected to a luminaire. In other words, the lighting module may function as a standalone lighting device.

[0111] In such an example, the one or more light sources may be further configured to output, in addition to the light pulse, a further light in a further visible wavelength band, i.e., different (though potentially similar to) the visible wavelength band of the luminaire.

[0112] Each light source of the one or more light sources may be configured to output both (though not necessarily at the same time) the light pulse and the further light. Alternatively, the one or more light sources may be split into a first set, configured to output the light pulse, and a second set, configured to output the further light.

[0113] Furthermore, the controller may be configured to drive the one or more light sources to output both (though not necessarily at the same time) the light pulse and the further light. For example, the controller may send a first driving signal (to the one or more light sources) to trigger emission of the light pulse and a second driving signal to trigger emission of the further light.

[0114] The further visible wavelength band may partially, or completely, overlap with the predetermined wavelength band, or may not overlap at all with the predetermined wavelength band. In other words, the further visible wavelength band includes light in a wavelength band outside of the predetermined wavelength band and may also include light in a wavelength band inside of the predetermined wavelength band.

[0115] The purpose of the further light, similar to that of the luminaire, is to illuminate an environment so as to enhance the visibility of the environment and the objects within the environment. Accordingly, the further visible wavelength band may be perceived primarily as white light. In this way, the lighting module, as a stand-alone lighting device, may also achieve the function of the luminaire.

[0116] In much the same way as how the controller controls the intensity of light output by the luminaire, the controller of the lighting module may also control the intensity of the further light during the light pulse. More specifically, the controller may be configured to reduce the intensity of the further light during the light pulse from a further first intensity to a further second, lower intensity.

[0117] In some examples, the further second intensity may be no more than 50% of the further first intensity of the further light. Furthermore, the controller may be configured to stop the one or more light sources outputting the further light during the light pulse.

[0118] It will be clear from the hereby disclosed examples how the lighting module may be implemented into different settings to provide a regular dosage of the predetermined wavelength band to a subject and / or a group of subjects, i.e., a population, for triggering a photo-biomodulation response. More specifically, the dosage is provided to the subject(s) passively as part of their everyday routines, i.e., they do not need to actively think / remember to take the dosage via a personal care device - it is simply provided to them automatically from ambient lighting.

[0119] By providing the predetermined wavelength band dosage to a general population as part of an everyday routine, the lighting routine of the lighting module becomes a preventative treatment rather than a therapeutic treatment. Put another way, it will be understood that the general population may be modelled as primarily or majoritarily comprising subjects without health problems and / or diseases, e.g., eye-related health issues such as myopia and AMD. The lighting routine aims to trigger a photo-biomodulation response in a subject for the purposes of preventing disease(s) rather than treating disease(s), thereby improving / supporting the long-term health of the subject.

[0120] Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality.

[0121] The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0122] If the term "adapted to" is used in the claims or description, it is noted the term "adapted to" is intended to be equivalent to the term "configured to".

[0123] Any reference signs in the claims should not be construed as limiting the scope.

Claims

CLAIMS1. A lighting module adapted to connect to a luminaire, wherein the luminaire is configured to output light in a visible wavelength band and configured to be controlled by the lighting module when the lighting module is connected to the luminaire, the lighting module comprising: one or more light sources configured to output a light pulse in a predetermined wavelength band for irradiating an environment and intended to trigger a photo-biomodulation response in a subject positioned or located within the environment; a controller configured to drive the one or more light sources to output the light pulse; and a connector for connecting the lighting module to the luminaire, wherein, when connected to the luminaire, the lighting module is configured to control the luminaire to reduce an intensity of the light output by the luminaire during the light pulse from a first intensity to a second, lower intensity.

2. The lighting module of claim 1, wherein the predetermined wavelength band is between the range of 620 nm to 850 nm.

3. The lighting module of any one of claims 1 or 2, wherein the light pulse has a duration of at least 2 minutes.

4. The lighting module of any one of claims 1 to 3, wherein the second intensity is no more than 50% of the first intensity.

5. The lighting module of claim 4, wherein the lighting module is configured to stop the luminaire outputting light during the light pulse.

6. The lighting module of any one of claims 1 to 5, wherein the controller is configured to drive the one or more light sources to output the light pulse one or more times per day.

7. The lighting module of any one of claims 1 to 6, wherein the controller is configured to drive the one or more light sources to output the light pulse at least once per hour.

8. The lighting module of any one of claims 1 to 7, wherein the controller is configured to drive the one or more light sources to output the light pulse no more than two times per hour.

9. The lighting module of any of claims 1 to 8, wherein the controller is configured to drive the one or more light sources to output the light pulse when one or more predefined conditions are met.

10. The lighting module of any one of claims 1 to 9, wherein the controller is configured to operate in either a first operating mode or a second operating mode, wherein a maximum duration of the light pulse is longer in the second operating mode than in the first operating mode.

11. The lighting module of claim 10, wherein the controller is configured to: operate in the first operating mode in response to one or more first predetermined conditions being satisfied; and operate in the second operating mode in response to one or more second predetermined conditions being satisfied.

12. The lighting module of any of claims 1 to 11, wherein the one or more light sources are further configured to output a further light in a further visible wavelength band, wherein the further visible wavelength band includes light in a wavelength band outside of the predetermined wavelength band.

13. A luminaire adapted to be connected to a lighting module, wherein the lighting module is configured to output a light pulse in a predetermined wavelength band for irradiating an environment and wherein the lighting module is further configured to control the luminaire when the lighting module is connected to the luminaire, the luminaire comprising: one or more luminaire light sources configured to output a light in a visible wavelength band for irradiating an environment; a controller configured to drive the one or more luminaire light sources to output the light in the visible wavelength band; and a connector for connecting the luminaire to the lighting module, wherein, when connected to the lighting module, the luminaire is configured to be controlled by the lighting module to reduce an intensity of the light output by the luminaire from a first intensity to a second, lower intensity during the light pulse from the lighting module.

14. A kit of parts comprising: a lighting module according to any one of the claims 1 to 12; and a luminaire according to claim 13.

15. A method of irradiating an environment, the method comprising: providing a lighting module comprising one or more light sources configured to output a light pulse in a predetermined wavelength band for irradiating an environment and intended to trigger a photo-biomodulation response in a subject positioned or located within the environment, and a controller configured to drive the one or more light sources to output the light pulse; providing a luminaire comprising one or more luminaire light sources configured to output a light in a visible wavelength band for irradiating an environment, and a controller configured to drive the one or more luminaire light sources to output the light in the visible wavelength band; (c) connecting the lighting module to the luminaire; connecting the lighting module to the luminaire; andcontrolling, by a controller of the lighting module, the luminaire to reduce an intensity of the light output by the luminaire from a first intensity to a second, lower intensity during a light pulse from the light module.

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