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A Wireless Embedded Device For Personalized Ultraviolet Monitoring

Navid Amini Jerrid Matthews Alireza Vahdatpour Foad Dabiri Hyduke Noshadi Majid Sarrafzadeh. A Wireless Embedded Device For Personalized Ultraviolet Monitoring. Importance. The skin care product market is growing due to the threat of ultraviolet (UV) radiation caused:

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A Wireless Embedded Device For Personalized Ultraviolet Monitoring

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  1. Navid Amini Jerrid Matthews Alireza Vahdatpour Foad Dabiri Hyduke Noshadi Majid Sarrafzadeh A Wireless Embedded Device For Personalized Ultraviolet Monitoring

  2. Importance The skin care product market is growing due to the threat of ultraviolet (UV) radiation caused: Destruction of the ozone layer Increasing demand for tanning The tendency to wear less clothing Potential demand for a personalized UV monitoring device,  cancer prevention by providing measurements of UV radiation intensities and corresponding recommendations. 2

  3. Summary Based on a novel software architecture, a high-end UV sensor, and conventional PDA (or a cell phone). short-term applications: calculating the UV index  maximum recommended sun exposure time. Long-term applications: it displays the amount of UV received over a certain course of time, from a single day to a month. Low energy consumption and high precision in estimating the UV index (precision of 0.2). 3

  4. Summary • UVI precision is ± 0.2 UVI and is extendable to 0.1. • Noise cancellation in hardware • Noise cancellation in software • Our Accuracy to estimate the UV index is two and five times higher than current UV index estimators: • EryF from Scitec • Oregon Scientific UV Sensor • Exploiting the dynamic power management technique on the UV sensor • Two times longer lifetime relative to EryF from Scitec 4

  5. Did You Know? The skin is the largest organ of the body Most Common Cancer = Skin Cancer! 1.3 Million Cases in the U.S. ~ 1 person dies every hour Melanoma is considered as the most lethal form of skin cancer. In the year 2008, about 62,480 persons are expected to be diagnosed with melanoma resulting in the death of an estimated 8,420 individuals (California). Alarmingly, the incidence of melanoma is increasing rapidly in children. The radiation of UV is about 10% of total solar radiation. It is divided into three ranges based on the wavelength: UV-A (320-400 nm), UV-B (280-320 nm), and UV-C (100-280 nm). 5

  6. UV Index The Global Solar UV Index (UVI) describes the level of solar UV radiation at the Earth’s surface. The values of the index range from zero upward – the higher the index value, the greater the potential for damage to the skin and eye, and the less time it takes for harm to occur. The calculations are weighted in favor of the UV wavelengths that human skin is most sensitive to according to the McKinlay-Diffey erythema action spectrum curve 6

  7. UV Index The study of the erythemal influence has been frequently based on the minimum dose of UV erythemal radiation that will produce a noticeable reddening of human skin that has not been previously exposed to solar radiation. This dose is known internationally as the MED (minimum erythemal dose) and is always related to a specific skin type. If the UV irradiance is 1 MED/hour, then it will take an hour for a person exposed to this irradiance to receive the minimum erythemal dosage. 1 MED corresponds to a total dose of 210 J/m2. Thus 1 MED/hour = (210 J/m2)/3600 s = 58.3 mW/m2 = 2.33 UVI.

  8. UVI Versus Location 1.  85% increase from snow reflection2.  100% increase at 3000m altitude3.  25% increase from white-water reflection4.  80% of UV rays pass through cloud5.  20% from sand and grass reflection  - and 40% when wet6.  15% reflection from concrete buildings7.  50% can be reflected into shaded areas8.  50% UVB and 80% UVA passes through the upper 50cm of water9.  50% increase from water reflection http://www.socialuvwatcher.com/ 8

  9. Schematic Diagram

  10. The world’s first UV sensor IC to be based on SOI-CMOS technology It integrates a UV light-receiving element and an analog output circuit into a single chip. This helps to reduce the number of components, cost and size compared to conventional devices. IC includes an energy-saving standby function, it is perfect for battery driven portable mobile devices which require low power consumption. Components: UV Sensor ML8511 from OKI Semiconductor Introduced 8 months ago http://www.socialuvwatcher.com/ 10

  11. Features Optical sensor for UV-A and UV-B Analog voltage output Low supply current ( 300 μA typ. ) and Low standby current ( 0.1 μA typ. ) Small and thin surface mount package Functions UV sensor (PN-photodiode) Current-to-voltage converting amplifier Components: UV Sensor ML8511 from OKI Semiconductor http://www.socialuvwatcher.com/ 11

  12. Components: UV Sensor Spectral sensitivity characterisitics of the ML8511. http://www.socialuvwatcher.com/ 12

  13. ADC Output and Corresponding UV Indices (Vcc = 3.0 V) It should be noted that the Maxim1678 DC-DC converter which is located on the MICAz mote provides a solid 3V supply operated off a pair of AA batteries. 13

  14. The flowchart of the software If you use a sunscreen, the exposure time will be multiplied by the sun protection factor (SPF) of the applied sunscreen. Maximum Exposure Algorithm: Exposure Time * SPF 14

  15. Examples • Skin types and corresponding tolerated MEDs and maximum exposure time. • A person with a skin type of 3, in a UV index of 10, will start to sunburn • after just 20 minute of unprotected exposure to the sun: • If this person uses an SPF 30 sunscreen this becomes 600 minutes, or 10 hours: 15 15

  16. Experimental Results The data were gathered on a partially cloudy day in June in Los Angeles and we kept the device fixed on the roof of an eight-story building.

  17. Energy Consumption Average power consumption for different parts of personalized UV monitoring device. in this embedded device, we achieved an energy saving of up to 60% in the sensing part as opposed to an always-on sensor system The calculation of the UV index is performed every 15 seconds and in order to get an accurate estimation of the UV index, the average of four consecutive sensor measurements is taken into account. 17

  18. Accuracy Due to noise cancellation in software, and also considering the fact that ML8511 is less sensitive to the angle with respect to the sun, we were able to extract the UV index with the precision of 0.2 which is 2 and 5 times more accurate than previous tiny devices produced by (OS 2008) and (EPP 2008). 18

  19. Future Work The gathered data show that unlike similar UV sensors, ML8511 is less sensitive to the angle with respect to the sun. 20 degrees rotation  10 percent decrease in the UV Index 1- Integrating the system with a gyro to correct the error caused by rotation. 2- Putting a specified number of sensor on a Half Sphere and taking the maximum over their outputs. 19

  20. Ferguson, K., 2005, Melanoma (Clinical updates). Journal of Continuing Education in Nursing, Vol. 36, No. 6, pp. 242–243. Sue, N., Roberta, S., 2002, The management of high-risk melanoma: Staging, treatment, and nursing issues, Journal of Dermatology Nursing, Vol. 14, pp. 363. Hall, H. I., Miller, D. R., Rogers, J. D., Bewerse B., 1999, Update on the incidence and mortality from melanoma in the United States, Journal of the American Academy of Dermatology, Vol. 40, pp. 35–42. Boscoe, F., Schymura M., 2006, Solar ultraviolet-B exposure and cancer incidence and mortality in the United States, BMC Cancer Journal, Vol. 6, pp. 264. ACS, 2008, American Cancer Society, Cancer facts and figures, http://www.cancer.org/. Strouse, J. J., Fears, T. R., Tucker, M. A., Wayne A. S., 2005, Pediatric melanoma: Risk factor and survival analysis of the surveillance, epidemiology and end results database, Journal of Clinical Oncology, Vol. 23, pp. 4735–4741. Hu, S., Ma, F., Collado-Mesa, F., Kirsner, R. S., 2004, UV radiation, latitude, and melanoma in US Hispanics and blacks. Archives of Dermatology, Vol. 140, pp. 819–824. Jemal, A., Devesa, S. S., Fears, T. R., Hartge, P., 2000, Cancer surveillance series: Changing patterns of cutaneous malignant melanoma mortality rates among whites in the United States, Journal of the National Cancer Institute, Vol. 92, 811–818. DeFabo, E.C., Noonan F.P., 1983, Mechanism of immune suppression by ultraviolet radiation in vivo. I. Evidence for the existence of a unique photoreceptor in skin and its role in photoimmunology, The Journal of Experimental Medicine, Vol. 158, pp. 84-98. Herlihy, E., Gies, H.P., Roy, C.R. Jones, M., 1994, Personal dosimetry of solar UV radiation for different outdoor activities, JournalofPhotochemistry and Photobiology, Vol. 60, pp. 288-294. Wong, C.F., Toomey, S., Fleming, R.A., Thomas, B.W., 1995, UV-B radiometry and dosimetry for solar measurements, Journal of the Health Physics Society, Vol. 68, No. 2, pp. 175–184. RMI, 2008, The Royal Meteorological Institute of Belgium, http://www.meteo.be/. Solar, 2008, Solar Light Company, 501 UV-Biometer, http://www.solar.com. OS, 2008, Oregon Scientific Company, UV Monitor with Exposure Timer, http://www.oregonscientific.com. EPP, 2008, ePlus premium Ltd., UV Index Meter, http://www.eplus-premium.com Maddodi, N., Setaluri, V., 2008, Role of UV in Cutaneous Melanoma, Journal of Photochemistry and Photobiology, Vol. 84, No. 2, pp. 528–536. Liu, C.M., 2000, Surface erythemally weighted UVB flux in Taiwan, Terrestrial Atmospheric and Oceanic Sciences, Vol. 11, No. 4, pp. 879–894. HKO, 2008, Hong Kong Observatory, UV index forecast, http:.www.hko.gov.hk. WMO 2008, World Meteorological Organization, UV index, http://www.wmo.int. Gies, P., 2000, Photoprotection by clothing, Photodermatol Photoimmunol Photomed, Vol. 23, No. 6, pp. 264-274. OKI, 2008, OKI Semiconductor, ML8511 UV sensor, http://www.oki.com/. References

  21. UNEP, 2008, United Nations Environment Programme, UV index, http://www.unep.org/. Kramer, M., Geraldy, A., 2006, Energy Measurements for MicaZ Node, http://vs.informatik.uni-kl.de/. Vanicek, K., Frei, T., Litynska, Z., Schnalwieser, A., 2000, UV-Index for the Public, COST-713 Action (UV-B Forecasting), Office for Official Publications of the European Communities, pp. 27. Parisi, A. V., Kimlin, M. G., Wong J. C. F., Wilson, M., 2000, Diffuse component of the solar ultraviolet radiation in tree shade, Journal of Photochemistry and Photobiology B: Biology, Vol. 54, pp. 116–120. HKO, 2008, Hong Kong Observatory, UV index forecast, http:.www.hko.gov.hk. WMO 2008, World Meteorological Organization, UV index, http://www.wmo.int. UNEP, 2008, United Nations Environment Programme, UV index, http://www.unep.org/. Kramer, M., Geraldy, A., 2006, Energy Measurements for MicaZ Node, http://vs.informatik.uni-kl.de/. Vanicek, K., Frei, T., Litynska, Z., Schnalwieser, A., 2000, UV-Index for the Public, COST-713 Action (UV-B Forecasting), Office for Official Publications of the European Communities, pp. 27. Parisi, A. V., Kimlin, M. G., Wong J. C. F., Wilson, M., 2000, Diffuse component of the solar ultraviolet radiation in tree shade, Journal of Photochemistry and Photobiology B: Biology, Vol. 54, pp. 116–120. Gies, P., 2000, Photoprotection by clothing, Photodermatol Photoimmunol Photomed, Vol. 23, No. 6, pp. 264-274. OKI, 2008, OKI Semiconductor, ML8511 UV sensor, http://www.oki.com/. References 21

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