Low-Cost Prototype to Automate the 3D Digitization of Pieces: An Application Example and Comparison.

This work is aimed at describing the design of a mechanical and programmable 3D capturing system to be used by either 3D scanner or DSLR camera through photogrammetry. Both methods are widely used in diverse areas, from engineering, architecture or archaeology, up to the field of medicine; but they also entail certain disadvantages, such as the high costs of certain equipment, such as scanners with some precision, and the need to resort to specialized operatives, among others. The purpose of this design is to create a robust, precise and cost-effective system that improves the limitations of the present equipment on the market, such as robotic arms or rotary tables. For this reason, a preliminary study has been conducted to analyse the needs of improvement, later, we have focused on the 3D design and prototyping. For its construction, there have been used the FDM additive technology and structural components that are easy to find in the market. With regards to electronic components, basic electronics and Arduino-based 3D printers firmware have been selected. For system testing, the capture equipment consists of a Spider Artec 3D Scanner and a Nikon 5100 SLR Camera. Finally, 3D models have been developed by comparing the 3D meshes obtained by the two methods, obtaining satisfactory results.

Pyogenic granuloma clinically and dermoscopically mimicking pigmented melanoma.

Pyogenic granuloma is a common, benign, acquired, vascular growth of skin and mucous membranes that usually presents as a solitary, rapidly, growing, papule or polyp that bleeds easily after minor trauma. The clinical diagnosis of this lesion is usually straightforward. Moreover, the dermoscopic features associated with pyogenic granulomas have been described recently. However, occasionally this tumor can be difficult to differentiate clinically and dermoscopically from other pigmented and vascular lesions. We report the case of an 18-year-old male who presented with a round, purple-black nodule with hemorrhagic crust, 1 cm in diameter, located on the lower part of the thorax. Dermoscopic evaluation revealed the presence of a blue-white veil, a black blotch, polymorphous atypical vessels, milky-red areas, and hemorrhagic crusts. The subsequent histopathological examination revealed a pyogenic granuloma. We present a case of pyogenic granuloma clinically and dermoscopically indistinguishable from a pigmented malignant melanoma.