A Comparative Study between Scanning Devices for 3D Printing of Personalized Ostomy Patches

This papers presents a comparative study of three different 3D scanning modalities to acquire 3D meshes of stoma barrier rings from ostomized patients. Computerized Tomography and Structured light scanning methods were the digitization technologies studied in this research. Among the Structured Light systems, the Go!Scan 20 and the Structure Sensor were chosen as the handheld 3D scanners. Nineteen ostomized patients took part in this study, starting from the 3D scans acquisition until the printed ostomy patches validation. 3D mesh processing, mesh generation and 3D mesh comparison was carried out using commercial softwares. The results of the presented study show that the Structure Sensor, which is the low cost structured light 3D sensor, has a great potential for such applications. This study also discusses the benefits and reliability of low-cost structured light systems.

UNEXUP, a robotic exploration technology for underground flooded mines

<p>UNEXUP is an EIT RawMaterials supported project (Project Number 19160) with the aim to improve and commercialize the robot-based technology developed in the H2020 UNEXMIN project (2016-2019). In UNEXMIN three underwater robot prototypes (UX-1 a,b,c) were built with geoscientific and navigational instruments capable of collecting valuable geological, mineralogical and spatial information from flooded mines without causing harm to the environment, risk to human lives, or high dewatering costs. This technology was tested in five different field trials and proved to be an efficient exploration method to sustainably evaluate the potential for mineral resources in these mines. For example, scanning sonars and structured light systems can map the environment even with near-zero visibility, the visible light cameras allow the identification of structural and geological features, the gamma-ray counter helps to identify minerals with natural radiation, and the pH, EC and water sampler allow the characterization of the waters in these sites.</p><p>In UNEXUP (2020-2022) the objective is to further improve this robot-based technology, test it in real-life environments, and commercialize it as an exploration service. The UNEXUP technology will comprise two new robots, which will add to the three UX-1s that were developed in UNEXMIN. These new robots consider the feedback and requirements from potential customers (e.g., mining companies and Geological Surveys) and other stakeholders of the predecessor project.</p><p>The first robot, UX-1Neo, is an upscaled version of UX-1, with the same dimensions and functionalities. This robot was built to address the limitations and malfunctions found in the previous line of robots, and it has software improvements that allow reduction of the number of operators, with faster mission setup time, and more efficient data collection and processing. With hardware improvements, it is a lighter, modular robot with better thruster control, an additional camera, and easily swappable batteries. The second robot, UX-2, to be built in 2021, will be a more complex unit with increased modularity, higher TRL, and greater operational depth. The modularity of both robots allow the sharing of some geoscientific instruments that are being developed, such as multispectral camera, water sampling unit, water chemistry measurement, and fluxgate magnetometer. In addition, there will be a rock sampling unit supported by a robotic arm, which will be developed exclusively for UX-2.</p><p>The robots will demonstrate their capabilities under real-life environments during the project. A real service-to-client approach is being carried out, and commercial missions have already been scheduled for the UX-1Neo in 2021. Some examples include a 3D inspection of a water well, geoscientific survey of a flooded salt mine, as well as other survey missions under discussion in Europe and worldwide.</p><p>Both robots are equipped with navigational and geoscientific instruments to address surveying requirements in flooded mines. However, there is a range of other applications for this technology, including: inspection of water wells and reservoirs, cultural heritage sites, cave exploration, environmental risk evaluation, and many other underwater structures that can benefit from this technology.</p>

ACCURACY INVESTIGATIONS OF IMAGE MATCHING TECHNIQUES BY MEANS OF A TEXTURED DUMBBELL ARTEFACT

In the last few years, photogrammetric methods for 3D surface reconstruction at close range have increased significantly in importance. On the one hand, this is due to the increased performance of the systems and on the other hand to the improved quality (accuracy, completeness) of the created point clouds. In order to verify the accuracy of various area probing methods, the German VDI guideline 2634 part 2 and 3 is applied. However, the high-precision test reference objects existing so far consist of diffuse textureless surfaces, so that passive methods, like image matching, cannot be compared with active methods (e.g. structured light systems). In order to make this possible, a certified textured dumbbell with an accuracy of better than 10 μm is presented in this paper, with the aim to examine the suitability of the textured dumbbell artefact for close-range photogrammetric 3D surface reconstruction. Furthermore, the accuracy level of a structured light system, Structure from Motion (SfM) and Multi-View Stereo Method (MVS) is verified and compared with each other.