Developer Prof. Irina (Iryna) Terenetskaya
Unlike UV-meters on the market measuring potentially hazardous (erythemal and mutagenic) UV radiation, UV D-biodosimeter is designed for direct measurements of the beneficial vitamin-D-synthesizing activity of sunlight and artificial UV sources. Such a device is essential towards balancing health risks and benefits of sunlight exposure for overcoming the pandemic of vitamin D deficiency and opens up new fields of UV lamps applications for health care technologies, food processing and private users.
The D-biodosimeter is based on the same in vitro photoreaction which begins the synthesis of vitamin D in human skin by the highly variable solar UV-B irradiation. Therefore, targets for UV-B photons in the biodosimeter are the provitamin D molecules embedded in specially designed UV transparent and stable matrix. To follow the photoreaction course in real time three operation modes of varying complexity have been developed (Proc. of SPIE, 2016, Vol. 9887 doi: 10.1117/12.2229756).
MODE 1. Spectrophotometric analysis using original software (for experienced professional)
MODE 2. The UV biodose is determined by the decrease in the sample transmission (for general use).
MODE 3. Visual detection of the UV biodose using 7-DHC in liquid crystalline matrix (for personal use).
In addition, as a result of detailed studies of vitamin D photosynthesis using a tunable laser and UV spectroscopy, a reliable algorithm and software have been developed for the direct calculation of previtamin D3 accumulation using solar UV spectra as input data into the photoreaction model to demonstrate the critical dependence of previtamin D3 accumulation on stratospheric ozone, air pollution, season, latitude etc. (Int. J. Remote Sensing, 2011, V. 32, № 21, pp.6205-6218).
In the developed Personal UV D-biodosimeter a film (polymer or hydrogel) with embedded provitamin D3 (7-DHC) molecules is used as a photosensitive material. The transmission of this film in the spectral range which corresponds to maximum absorption in the 7-DHC spectrum is dependent on the amount of synthesized previtamin D molecules, and its change at λ≈280 nm (as a result of UV exposure) is measured by a portable optoelectronic device ' VitaD '.
The external view of the ‘Vita-D’ biodosimeter (left) and its flow chart (bottom right): 1 - light-emitting diode LED, 2 - power supply, 3 - photosensitive material, 4 – photodiode, 5 – amplifier, 6 – microcontroller, 7 - LCD indicator panel, 8 - keyboard panel, 9 - electric battery, 19 – USB port.
At the top right the LED emission band is shown in relation to the provitamin D absorption spectra transformed during an UV exposure. The specific ‘antirachitic’ UV biodose can be calculated from the change of the film transmission measured before and after a sunlight exposure using a calibration chart that establishes a relationship between the transmission change and the accepted UV dose.
|Size of the photosensitive film||1x2 cm2|
|Dynamic range of the dose characteristics of the film||0-1000 J/m2|
|Controlled Waveband transmission||280 ± 10 nm|
|Measurement error||0.4 mJ/cm2|
|Number of stored measurements||200|
|Voltage consumed||+9 V|
|Battery life without recharging||38 hours|
|Unit dimensions||18x5x3 cm3|
|Unit weight||400 g|
HEALTH, MEDICINE: Care and Health Services; Clinical Research and Trials; Laboratory Equipment, Biomedical Engineering, Physiotherapy (Phototherapy), E-health and Education; Health information
ECOLOGY: UV D-index, indication of air and water pollution, Climate, Structuring data for decision-making.
BIOLOGY / BIOTECHNOLOGY: Biochemistry / Biophysics; Molecular Biology; Engineering; In vitro Testing, Trials
AGRICULTURE / FOOD: Vitamin D enriched food (mushrooms, yeast products) due to dosed UV irradiation