WO2017042682A1

WO2017042682A1 - A system for computing solar radiation seen by an individual

Info

Publication number: WO2017042682A1
Application number: PCT/IB2016/055303
Authority: WO
Inventors: Emilio Simeone
Original assignee: Flyby Srl
Priority date: 2015-09-09
Filing date: 2016-09-05
Publication date: 2017-03-16
Also published as: ITUB20153513A1

Abstract

A system for computing solar radiation seen by an individual (I), comprising: portable location means (2) for locating and tracking the position (P) of an individual (I) in the course of a day of direct or indirect exposure to the sun; data-collection means (1) containing satellite data (d2) regarding solar radiation in the traced position of the individual; computing means (3) operatively connected to said location means (2) and to said data-collection means (1) for receiving data (d1) regarding the position of the individual and data (d2) regarding solar radiation on the ground in the same position where the individual is in order to compute the dose (R1) of solar radiation seen by the individual and to compute a dose (R3) of solar radiation that is missing or is in excess with respect to an expected dose (R2) corresponding to a desired personal circadian rhythm of the individual (I).

Description

SYSTEM FOR COMPUTING SOLAR RADIATION SEEN BY AN INDIVIDUAL

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Sector of the invention

The present invention relates to a system for computing the dose of solar radiation seen by an individual, based upon satellite data.

More in particular, the system regards calculation of the dose of solar radiation, which is important for the purposes of optimal regulation of the personal circadian rhythm of an individual and hence of the quality of the sleep-wake cycle.

Prior art

It is known that each person has a circadian rhythm of his or her own, which is an endogenous oscillation of biological processes with a period of approximately 24 h. Some examples are the sleep-wake cycle, the melatonin cycle, the Cortisol cycle, etc.

Even though this "personal clock" is endogenous, so much so that it is possible to speak of a personal chronotype of the individual, it is markedly affected by external stimuli, the most important of which are the intensity and spectral distribution of the light seen by the individual during the day.

The circadian rhythm of each person is in fact different, and each individual adopts a specific temporal relation with respect to the day- night solar cycle (for example, the difference of time between the dawn and wake-up time, etc.). When individuals differ in this relation, they are said to be different chronotypes, and this depends upon various factors such as age, sex, sleep-wake behaviour, etc.

Various studies have shown that the human circadian rhythm is sensitive to the exposure to the light seen, and this response depends both upon the intensity and upon the wavelength of the light. In fact, exposure to light - and in particular to the blue component of visible light - suppresses secretion of melatonin, a hormone that affects the circadian rhythm.

The external light is obviously dominated by sunlight during the day. In this case, the circadian effects depend markedly upon the different components of sunlight on account of their different spectral distribution; for example, the light diffused by the sky is "bluer" than the direct light that arrives from the solar disk in conditions of clear sky.

During the day, the light that we see in indoor environments is dominated by the light that comes from outside filtered by the windows, while the impact of the artificial light on the circadian rhythm becomes important only when indoor lighting is the only source of light (for example, at night), with an important impact on the quality of the sleep and on well-being.

In cases of indoor lighting, it should also be recalled that many people pass quite a considerable amount of time in front of digital devices (e.g., smartphones, tablets, computers, etc.), even from six to ten hours a day, thus being exposed to the blue light emitted by all the LCD and LED devices of smartphones, tablets, TVs, and PCs, by the lighting systems, and by energy-saving lamps.

Considering that devices such as smartphones and tablets emit up to 40% of blue light and they are increasingly widespread, also the negative effects on the health of eyesight, and on the eye, are increasing.

A specific problem is represented by the fact that the close distance of use and the overexposure to blue light affect the circadian cycle inhibiting production of melatonin, thus creating or favouring disorders, such as insomnia, irritability, loss of attention, important eye disorders such as dry-eye syndrome, qualitative and quantitative alterations of the lachrymal film, photofobia, burning, irritation, chronic or recurrent conjunctivitis, early cataract, and macular degeneration.

One of the attempts of response to disorders linked to the circadian rhythm is the administration of exogenous melatonin. In fact, "forced" regulation of the melatonin cycle can effectively contribute in realigning the personal circadian clock, but it is very important to find the appropriate moment for administering the exogenous melatonin, given that the circadian system, just as a simple mechanical oscillator, responds in a different way to the stimulus (such as exposure to light or dosage of melatonin), anticipating, delaying, or not modifying at all the circadian phase.

It is consequently a widely known fact that the environmental conditions and personal behaviours affect considerably our circadian rhythm, at times altering proper operation thereof and causing possible disorders. In particular, the most typical situations that alter the circadian rhythm are the following:

- high-speed travel, typically air travel, between regions with different time zones (the so-called jet- lag);

- lifestyle with altered sleep-wake cycle;

- low exposure to solar light (for example, in polar regions); and

- shift work (e.g., night shifts).

In this general framework, tiredness is one of the most common disorders linked to circadian misalignment, which may lead also to further discomfort or disorders:

- incapacity of sleeping at night;

- loss of concentration;

- headache;

- general malaise; and

- altered Cortisol and melatonin rhythms.

Other possible effects of circadian misalignment on the mood (depression, seasonal affective disorder - SAD) are moreover under investigation.

Known to the prior art are systems for measuring solar radiation on the ground based upon satellite data, which are typically used for forecasting meteorological events or for making in any case forecasts based upon solar radiation.

Known, for example, from the document No. US201 1282514 is a method for forecasting the power that can be delivered by a photovoltaic system, comprising receiving meteorological data for the site where the photovoltaic system is installed and wherein the forecast of global horizontal irradiation is based upon satellite data, which are managed by a system for computing the future power of the photovoltaic system based upon the expected irradiation.

Systems of a known type do not make it possible, however, to evaluate the dose of circadian radiation received by an individual in the course of a day, for example during his or her normal working life.

There exist moreover systems that are capable of measuring the radiation received by an individual. An example of known device is represented by the patent application No. US2008265170, which describes a portable dosimeter for detecting UV radiation integrated with a measuring device of the skin type in which an electronics can provide information to the user as regards the amount of ultraviolet radiation present in the environment.

These known systems require, however, specific sensors that have to be worn, or in any case carried, by an individual who is interested in knowing the dose and spectral distribution of solar radiation received in order to evaluate the impact on his or her own circadian rhythm.

There is thus felt the need for a system for computing the dose of radiation received by an individual, based upon satellite data that will be able to inform the individual on the amount and spectral characteristics of the radiation seen in the course of the day, without any need to wear a specific sensor, in order to determine possible departure from a desired dose of exposure to solar radiation, for the purposes of regulation of the personal circadian rhythm.

Purpose of the invention

The purpose of the present invention is to overcome the drawbacks of the solutions already known and to propose a system that is based upon satellite data for computing the radiation seen and is capable of monitoring in the course of the day the radiation received by an individual (direct and diffused components and corresponding spectral distribution) and sending to the latter data regarding any possible misalignment with respect to the personal circadian rhythm in order to regulate it as well as possible.

A further purpose of the invention is to provide a tool for optimal regulation of the personal circadian rhythm by exploiting in a synergistic way data regarding exposure, position, control of indoor lighting, exogenous dosage of melatonin, and possible other parameters, such as the characteristics of spectral transmittance of the lenses of glasses. Summary of the invention

The above purposes are achieved by providing a system for computing the radiation seen, with corresponding evaluation of its impact on the circadian system and of a desired dose of radiation, according to at least one of the annexed claims.

A first advantage lies in the fact that the system is independent of the individual displacements and enables remote monitoring in quasi-real time of the impact of the local parameters on the circadian rhythm of the user, providing possible strategies to prevent circadian misalignment (amongst which adjustment of indoor lighting, assumption of exogenous melatonin or use of glasses with lenses of appropriate spectral transmittance, for example lenses treated to reduce exposure to the blue light emitted by digital devices, such as smartphones, tablets, and computers).

Another advantage lies in the fact that no portable sensors for detection and measurement are required.

A further advantage likewise lies in the fact that the system can be implemented with existing technologies readily accessible to an individual. Yet a further advantage lies in the fact that the impact of light on the circadian rhythm of the user can be calculated remotely (there not being any need for in-situ lux meters or similar radiometers) in quasi-real time, by exploiting satellite images of the Earth, the GPS data furnished by the device used by the user, and a modelling of the direct and diffused components of radiation and of the corresponding spectral distribution for the corresponding calculation of the specific circadian effect.

List of the drawings

The above and further advantages will be better understood by any person skilled in the branch from the ensuing description and from the annexed plate of drawings, which is provided by way of non-limiting example and in which:

Figure 1 shows schematically a system according to the invention.

Detailed description

Described with reference to the attached figure is a preferred embodiment of a system for computing solar radiation seen and of a desired dose of radiation received by an individual "I".

According to the invention, it is envisaged to evaluate a personal chronotype (CP) to be associated to the individual "I", for example through a dedicated questionnaire of the Munich Chronotype Questionnaire (MCTQ) type.

The system comprises portable location means 2 for locating and tracking the position P of an individual "I" in the course of at least a period of a day of direct or indirect exposure to sunlight.

Preferably, particularly advantageous location means comprise a satellite location system, for example of a GPS type, integrated in a portable device SP, such as a smartphone, a tablet, wearable devices, etc.

The system further comprises data-collection means 1 designed to contain satellite data d2 regarding solar irradiance in the position occupied by the individual, and may advantageously comprise a memory of a remote unit 6 that receives the data d2 from a satellite, which can be connected in wireless mode to the portable device SP. In a further example of embodiment, the means 1 for collection of the irradiance data d2 may comprise a storage unit of the portable device SP itself. According to the invention, the position data d1 and the irradiance data d2 are sent to a computing unit 3 pre-arranged for exchanging data with the location means and the collection means.

Advantageously, the computing unit 3 may, in particular, comprise an electronic-unit memory of the portable device SP that communicates with the GPS integrated system and moreover communicates in wireless mode with the remote unit 6.

According to the invention, the computing unit 3 is programmed for computing the dose R1 of circadian radiation seen by the individual, and the corrective dose R3 of circadian radiation, that is missing or is in excess, with respect to a desired optimal dose R2 and for sending to the individual information useful for suggesting strategies for mitigating consequent misalignment of the personal circadian rhythm (such as regulation of the indoor lighting, assumption of exogenous melatonin, or the use of glasses with lenses of appropriate spectral transmittance). By way of example, if an individual in a working day with conditions of very clear sky sees 204 Imh (lumen hour) of circadian light energy, the consequent delay of the circadian phase of the individual may be mitigated thanks to the data processed by the computing unit 3, which may propose exposure to a suffused light (for example, 250 lux) of a colour similar to twilight during the two hours prior to the typical time of start of sleep.

Otherwise, once again by way of example, if the individual in a working day with conditions of very cloudy sky sees 56 Imh (lumen hour) of circadian light energy, the consequent anticipation of the circadian phase of the individual may be mitigated thanks to the data processed by the computing unit 3, which may propose exposure to a strong white light (for example, 10000 lux) for two hours starting from the typical wake-up time.

In a preferred example of embodiment of the invention, illustrated in Figure 1 , the system consequently comprises a portable device SP equipped with a GPS location system, of a wireless communication unit WL, and with a storage and computing unit 3, which is able to acquire the position data d1 and the irradiance data d2 and to calculate the corrective dose R3 by means of a software program, for example an app purposely stored in the device SP.

In a preferred embodiment, the system further comprises means 4 for irradiating the individual with a dose of radiation correlated to said missing dose, constituted, for example, by coloured lamps, with different spectroradiometric characteristics, located in an environment accessible to the individual, for example his or her dwelling.

Advantageously, the calculation of the dose R3 may also be made at the start of the day via forecasts of circadian spectral irradiation and according to the characteristics of spectral transmittance of the lenses of the glasses worn by the individual or recommended to be worn so as to be able to obtain the desired optimal dose R2.

Advantageously, evaluation of the possible misalignment of the personal circadian cycle may possibly be made with greater precision also taking into account one or more of the following factors:

direction of sight of the user, detected via "smart" glasses 10 with an integrated compass 1 1 , which are capable of detecting the azimuthal direction of vision of the individual, and hence of enabling the system to determine the solar radiation effectively seen by the user R1 , and are connected to the computing unit 3 for sending data d4 regarding the direction of vision of the individual, also taking into account the effects of possible filters of the lenses, which are to be characterized previously according to their spectral transmittance; and

state of sleep, to be detected by means of a device that can be associated to the movements of the individual, for example a watch 7 equipped with accelerometer that can be worn by the individual, or a smartphone that is resting on the same support as that on which the individual is resting (typically the mattress of a bed) and is connected to the computing unit 3 for sending the data regarding the quality of the sleep of the individual and characterizing the essential parameters thereof with respect to the personal chronotype.

In a further preferred example of embodiment, the invention comprises means 5 for characterizing the radiation seen by the individual in a position P not exposed to direct solar radiation.

Preferably, the characterization means 5 comprise a camera, for example the camera of a portable device SP, which is operative for acquiring radiation for a period of time, for example some minutes, representing the radiation present in the same position P in the course of the solar day.

This characteristic is of particular advantage when the position P assumed by the individual for a significantly long time frame is inside a covered area, for example an office or a motor vehicle.

In a further preferred embodiment, the system comprises a watch 7 equipped with accelerometer, which is able, if it is worn by the individual, to detect the movements of the individual during sleep and, on the basis of these, to determine parameters d3 regarding the quality of sleep, which can be used by the computing unit 3 for implementing the calculation of the dose that is missing or is in excess to compensate for possible difficulties in the sleep-wake cycle, with a possible indication of the correct moment in time for implementing corrective measures and obtaining an optimal compensation.

The invention affords important advantages of application.

In a possible application, the system behaves like a system for computing the dose of circadian solar radiation seen that enables evaluation and diagnostics of the sleep rhythm (during the waking phase) and monitoring of the circadian rhythm.

In particular, starting from the personal chronotype, the circadian rhythm of the user is monitored taking into account the circadian light seen by the user (outdoors and indoors), the compensation provided by regulation of the indoor lighting, adoption of glasses with particular spectral transmittance, and assumption of exogenous melatonin.

The system hence enables exploitation of all the data acquired for monitoring and predicting possible misalignments/disorders linked to the circadian rhythm, in particular comprising some functions specifically dedicated to jet-lag (for example, for travel purposes) and to work (for example, periodic work shifts).

In outdoor use, the system enables:

- real-time use of the data that regard solar radiation seen by the user and are evaluated by the satellite (by exploiting the GPS information) without any need for local/personal sensors, taking into account different spectral curves of photobiological action (circadian effect, photopic effect, etc.);

- separation of the components of diffused and direct solar radiation;

- compensation of the calculation of the dose of radiation seen by the individual, also on the basis of possible glasses or absorption filters;

- integration of accessories such as compasses and glasses; and

- discrimination of whether the user is located out of doors or in an indoor environment or else again on board a motor vehicle or a train, on the basis of the position and speed deriving from the GPS information. In use in covered environments, the system makes it possible to take into consideration any type of radiation to which the person has been exposed in daily life (e.g., office, home), in particular by modelling solar radiation in covered exploiting, exploiting the orientation/size of the windows, as well as the typical distance of the individuals from the windows.

For example, to increase the computing precision, radiometric-calibration data may be available also just using as lux meter the camera of a smartphone with a diffuser applied for a few minutes in the position of use, making a measurement of characterization at a given time of the day in conditions of clear sky in the typical position assumed by the individual in the office or at home.

Possible examples of application

1. Jet lag

Travelling through a number of time zones causes an alteration of the circadian rhythm and consequent disorders of the wake-sleep cycle. By way of example, more than one week is typically necessary for "realigning" the circadian rhythm to the new time zone (i.e., to the new day-night cycle) in the case of an eight-hour time shift.

In this case, the invention enables a faster recovery from jet lag with adequate recommendations (for example, regarding internal lighting or assumption of exogenous melatonin, or use of glasses with adequate spectral transmittance).

By way of example, if the individual were to have to make a journey taking a flight that passes between areas with a six-hour time shift in an westerly direction (e.g., between Rome and New York), the consequent jet lag deriving from a lack of anticipation of the circadian rhythm could be attenuated with the system according to the invention, which makes it possible to recommend during the three days prior to the flight: assumption of 0.5 mg of melatonin approximately 5 h before the time typical of start of sleep, exposure to a strong white light (for example, 8000 lux) for two hours at the typical wake-up time, anticipation of the time of start of sleep by 1 hour every day, and exposure to suffused light (for example, 250 lux) of a colour similar to that of twilight in the hour prior to the time typical of start of sleep. For the return journey, instead, the possible jet lag deriving from a lack of delay of the circadian rhythm could be attenuated with the system of the invention, which makes it possible to recommend during the three days prior to the flight: assumption of 0.5 mg of melatonin approximately 1 1 h before the time typical of start of sleep, exposure to a strong white light (for example, 8000 lux) for an hour starting from two hours before the time typical of start of sleep, and delay of the time of start of sleep by one hour every day. Such regulations of lighting can also be obtained by wearing glasses with lenses having appropriate spectral transmittance in combination with the outdoor or indoor environmental light.

All the possible recommendations depend upon the typical personal circadian rhythm of the user who has to leave on a journey (chronotype), upon the light received in the previous days, and upon the behaviour of the user (e.g., the start-of-sleep and wake-up times): all the key parameters can be controlled by the system.

2. Sleep disorders

Another possible application is dedicated to people with sleep disorders (for example, with altered sleep-wake cycle, insomnia, etc.).

Moreover, shift work alters the normal functions of the circadian rhythm, and shift-workers suffer from the so-called social jet lag, induced by an altered wake-sleep cycle and by the anomalous light received by the eye photoreceptors (i.e., the lack of blue light linked to night work and to sleeping during the day). Shift work can cause various types of disorders.

The new system forming the subject of the invention, as in the case of jet lag, is able to support the worker in limiting these disorders, preventing any possible circadian misalignments by recommending an optimal regulation of artificial lighting, adoption of glasses with specific lenses, or assumption of exogenous melatonin.

As in the case jet lag, if a worker has started to work at 00:00 and finishes at 08:00 for a medium-to-long period, his circadian rhythm is not aligned.

In this case, some recommendations could be given by the system (for example, assumption of exogenous melatonin, glasses to be worn, etc.) in a different way both for adapting to the altered wake-sleep cycle during shift work or for "readapting" to the normal cycle when the working shift is concluded.

The invention has been described with reference to a preferred embodiment, but it is understood that equivalent modifications may be made, without thereby departing from the sphere of protection granted to the present industrial patent right.

Claims

1 . A system for computing solar radiation seen by an individual (I), comprising:

means (CP) for determining a parameter associated to the chronotype of the individual (I);

portable location means (2) for locating and tracking the position

(P) of an individual (I) in the course of at least a period of a day of direct or indirect exposure to the sun;

data-collection means (1 ) containing satellite data (d2) regarding circadian solar radiation in the traced position of the individual during at least a period of time of the solar day;

computing means (3) operatively connected to said location means (2) and to said data-collection means (1 ) for receiving at least:

data (d1 ) regarding the position of the individual; and data (d2) regarding circadian solar radiation on the ground in the same position where the individual is in said period of time, and for computing the dose (R1 ) of circadian radiation seen by the individual and the dose (R3) of circadian radiation that is missing or is in excess with respect to a desired optimal dose (R2); and

means for communicating to the individual one or more corrective parameters of his or her own circadian rhythm and/or for sending to the individual information useful for suggesting strategies for mitigating the consequent misalignment of the personal circadian rhythm of the individual (I), such as, for example, regulation of indoor lighting, adoption of glasses with lenses with appropriate spectral transmittance to be worn, or assumption of exogenous melatonin.

2. The system according to Claim 1 , comprising means (4) operatively connected to said computing means (3) for irradiating the individual with a dose of radiation correlated to said missing dose (R3), for example lamps that irradiate coloured light in an environment accessible to the individual.

3. The system according to either of the preceding claims, comprising second computing means (8) operatively connected to said first means (3) for computing a dose of exogenous melatonin that is to be administered to the individual.

4. The system according to any one of the preceding claims, comprising computing means (9) operatively connected to said first means (3) for computing a spectral transmittance of lenses of glasses correlated to the dose (R3) that is missing or is in excess.

5. The system according to any one of the preceding claims, comprising means (5) for characterizing the radiation received by the individual in at least a period of exposure during the solar day and in a position (P) not exposed to direct solar radiation.

6. The system according to Claim 4, wherein said location means comprise a satellite location system, for example of a GPS type integrated in a portable device (SP), and wherein said characterization means (5) comprise means for detecting the environmental light level, for example a video camera or a brightness sensor, which are integrated in the portable device (SP) and are operative for acquiring radiation for a period of time representing the radiation present in the same position (P) in at least a period in the course of the solar day, said portable device comprising electronic means connected to said means for detecting the environmental light level for processing data regarding the radiation acquired and computing a measurement of the radiation present in the position (P).

7. The system according to any one of the preceding claims, wherein said computing means (3) comprise a processing and computing unit of an electronic unit of a portable device (SP).

8. The system according to any one of the preceding claims, wherein said computing means (3) comprise a remote processing and computing unit.

9. The system according to one or more of the preceding claims, wherein said data-collection means (1 ) comprise a remote unit (6), which can be connected in wireless mode to said computing means (3) for sending said data (d2) regarding solar radiation on the ground in the position of the individual.

10. The system according to any one of the preceding claims, comprising a device that can be associated to the movements of the individual, for example a watch (7), which is equipped with accelerometer that can be worn by the individual and is connected to the computing unit (3) for sending data (d3) regarding the quality of sleep of the individual.

1 1 . The system according to any one of the preceding claims, comprising a device that can be associated to the azimuthal direction of vision of the individual, for example glasses (10) equipped with a compass (1 1 ) and connected to the computing unit (3) for sending data (d4) regarding the direction of vision of the individual.