10 research outputs found

    Anisotropic convective effects associated with near surface blood flow.

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    <p>(<b>a</b>) Spatial map of changes in temperature at each element for a device located at the volar aspect of the wrist. The position of the thermal actuator coincides with a large vein. (<b>b</b>) Difference in temperature between element 11 (E11) and element 3 (E3). The results show effects of anisotropic heat flow in the wrist, compared to isotropic distributions typically observed on a region of the body such as the cheek. The vertical red dashed lines correspond to initiation and termination of heating, respectively.</p

    Thermal flow associated with low level transient heating on the surface of the skin.

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    <p>(<b>a</b>) Infrared image during heating at a single thermal actuator in an array device on the skin. (<b>b</b>) Finite element modelling results for the distribution of temperature during rapid, low level heating at an isolated actuator on the skin, after 1.2 s of heating at a power of 3.7 mW mm<sup>-2</sup>. (<b>c</b>) Spatial map of the rise in temperature due to transient heating sequentially in each element in the array. The solid black lines are experimental data; the red dashed lines are best fit calculations. The strong rise shown in upper leftmost element results from local delamination of the device from the skin. (<b>d</b>) Experimental data (solid lines) and best fit calculations (dashed lines) for the cheek (black) and heel (blue), along with extracted thermal transport properties.</p

    UV sensor structure.

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    <p>(A) Construction of the UV sensor (from the top to the bottom): protective liner with adhesive, permeable polyurethane (TPU, 16 μm) with printed UV ink, UV blockers and reference colors, top skin adhesive layer (25 μm), NFC antenna (yellow, 18 μm) and polyimide film encapsulation (PI, 12.7 μm), NFC antenna and chip (0.5 mm), polyethylene terephthalate layer (PET, 12 μm), bottom skin adhesive layer (25 μm), and bottom liner. (B) The front of the UV patch. (C) The back of the UV patch. Bar = 10 mm. (D) Wearing the UV patch on the back of one’s hand. (E) Reading the UV patch using the My UV Patch app.</p

    Comparison of UV readings among UV patch image analysis, Scienterra dosimeter and the mobile application.

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    <p>UVA readings by patch picture analysis showed high correlation with Scienterra dosimeter readings, which validates the UV sensor image technique <i>p</i> < 0.0001, <i>r</i> = 0.88, n = 30 (A). When compared between the patch picture analysis and app reading, the data still shows good correlation but the fast patch scanning requirement for improved user experience affected data quality <i>p</i> < 0.0001, <i>r</i> = 0.92, n = 30 (B). Similar result is shown between Scienterra dosimeter and app reading <i>p</i> < 0.0001, <i>r</i> = 0.92, n = 24 (C). The total UV dose shows a good correlation between the Scienterra dosimeter and patch picture analysis <i>p</i> < 0.0001, <i>r</i> = 0.87, n = 24 (D). The 95% prediction ellipse is shown. The strong correlation among the three measurements further validates the sensor system.</p