Method and apparatus for predictive, context-aware, and networked exposure time monitoring

1. A method comprising:

storing, in a memory, personal information including skin phototype and sun protection factor information;

obtaining context related information including an activity, a location, and a time of day;

retrieving environmental conditions that affect ultraviolet exposure, the environmental conditions including weather conditions, where the weather conditions are retrieved from a network;

predicting ultraviolet exposure time based on the personal information, the context related information, and the environmental conditions; and

outputting information corresponding to the ultraviolet exposure time;

wherein predicting ultraviolet exposure time is based on erythemal effective radiant exposure as a function of the context related information and the environmental conditions.

2. The method according to claim 1 ,

wherein the environmental conditions further include environmental surface reflectivity conditions, and

wherein the context related information includes a date of the activity and altitude conditions.

3. The method according to claim 1 , further comprising receiving an ultraviolet reading from a local sensor,

wherein predicting further comprises predicting ultraviolet exposure time based on the personal information, the context related information, the environmental conditions, and the ultraviolet reading.

4. The method according to claim 1 , wherein the activity comprises activity information indicating an outdoor activity a user is engaging in.

5. The method according to claim 1 , wherein the information corresponding to the ultraviolet exposure time includes one of a protection recommendation, an exposure time recommendation, an ultraviolet index alert signal, and an exposure alert signal.

6. The method according to claim 1 wherein erythemal effective radiant exposure is based on solar spectral irradiance as a function of the context related information and the environmental conditions, and erythemal effective radiant exposure is further based on erythema action spectrum, time, and relevant wavelengths.

7. The method according to claim 1 , wherein predicting ultraviolet exposure time is based on personal information and erythemal effective radiant exposure according to:

H* er =∫∫E* λ s er (λ) dλdt

where H* er is the erythemal effective radiant exposure,

where E* λ is solar spectral irradiance as a function of the context related information and the environmental conditions,

where s er (λ) is erythema action spectrum,

where t is time, and

where λ is relevant wavelength.

8. The method according to claim 7 , wherein

s er (λ)=1.0 for 250≦λ≦298 nm,

s er (λ)=10 0.094(298-λ) for 298<λ≦328 nm, and

s er (λ)=10 0.015(140-λ) for 328<λ≦400 nm.

9. The method according to claim 1 , wherein predicting future ultraviolet exposure time is based on an ultraviolet index that is determined based on erythemal effective radiant exposure as a function of the personal information, the context related information, and the environmental conditions.

10. The method according to claim 1 , wherein predicting ultraviolet exposure time is based on personal information and an ultraviolet index according to:

I

UV

*

=

k

er

⁢

∫

250

⁢

⁢

nm

400

⁢

⁢

nm

⁢

E

λ

*

⁢

s

er

⁡

(

λ

)

⁢

ⅆ

λ

where I* UV is ultraviolet index,

where k er is a radiation constant value,

where E* λ is solar spectral irradiance as a function of the context related information and the environmental conditions, and

where s er (λ) is erythema action spectrum.

11. The method according to claim 1 , wherein the weather conditions comprise forecast weather conditions.

12. The method according to claim 1 , further comprising:

detecting a change in the environmental conditions during the predicted ultraviolet exposure time; and

predicting an updated ultraviolet exposure time based on the personal information, the context related information, and the changed environmental conditions.

13. An apparatus comprising:

a housing;

a controller coupled to the housing, the controller configured to control the operations of the apparatus;

a memory coupled to the controller, the memory configured to store personal information including skin phototype and sun protection factor information;

an input coupled to the controller, the input configured to obtain context related information including an activity, a location, and a time of day;

a network interface coupled to the controller, the network interface configured to retrieve environmental conditions that affect ultraviolet exposure, the environmental conditions including weather conditions;

an ultraviolet exposure time prediction module coupled to the controller, the ultraviolet exposure time prediction module configured to predict future ultraviolet exposure time based on the personal information, the context related information, and the environmental conditions; and

a display coupled to the controller, the display configured to output information corresponding to the ultraviolet exposure time;

wherein the ultraviolet exposure time prediction module is configured to predict ultraviolet exposure time based on an ultraviolet index that is determined based on erythemal effective radiant exposure as a function of the personal information, the context related information, and the environmental conditions.

14. The apparatus according to claim 13 , wherein the network interface comprises a wireless transceiver.

15. The apparatus according to claim 13 , further comprising an ultraviolet sensor coupled to the controller, the ultraviolet sensor configured to detect ultraviolet light,

wherein the ultraviolet exposure time prediction module is configured to predict ultraviolet exposure time based on the personal information, the context related information, the environmental conditions, and the detected ultraviolet light.

16. The apparatus according to claim 13 ,

wherein the ultraviolet exposure time prediction module is configured to predict ultraviolet exposure time based on the personal information and erythemal effective radiant exposure, and

wherein erythemal effective radiant exposure is based on solar spectral irradiance as a function of the context related information and the environmental conditions and the erythemal effective radiant exposure is also based on erythema action spectrum, time, and a relevant wavelength.

17. The apparatus according to claim 13 , wherein the controller is configured to detect a change in the environmental conditions during the predicted ultraviolet exposure time, and

wherein the ultraviolet exposure time prediction module is configured to predict an updated ultraviolet exposure time based on the personal information, the context related information, and the changed environmental conditions.

18. A method comprising:

storing, in a memory, personal information including skin type and sun protection factor information;

obtaining context related information including activity information indicating an outdoor activity a user is engaging in, a location, a date, and a time of day;

retrieving environmental conditions that affect ultraviolet exposure, the environmental conditions including forecast weather conditions, where the forecast weather conditions are retrieved from a network;

predicting future ultraviolet exposure time based on personal information and erythemal effective radiant exposure, where erythemal effective radiant exposure is based on solar spectral irradiance as a function of the context related information and the environmental conditions, and erythemal effective radiant exposure is further based on erythema action spectrum, time, and a relevant wavelength; and

outputting information corresponding to the future ultraviolet exposure time.