Characterizing analogue caldera collapse with computerized X-ray tomography

Analogue models of caldera collapse were imaged by computerized X-ray tomography (μCT). Interval μCT radiography sequences document ‘2.5D’ surface and internal model deformation in an unprecedented way, and carry the potential for a better understanding of the kinematics of various volcano-tectonic processes, of which caldera collapse is a mere illustration. A semi-automatic subsidence velocity analysis was carried out on radiographs. The developed method is a step towards the quantitative documentation of volcano-tectonic modelling that would render data interpretations immediately comparable to monitoring data available from recent deformation at natural volcanoes

Whole body scanning as a tool for clothing sizing: Effects on women’s body satisfaction

Whole-body scanning is increasingly used in the clothing industry, including in large-scale sizing surveys and virtual fitting. However, the impacts of 3D scanning on women’s body satisfaction are unclear as no previous studies have investigated impacts in a controlled experiment. This experiment investigated any causal effect of 3D whole-body scanning, as used in clothing applications, on women’s body satisfaction. Seventy women aged 18-35 years completed body image measures at baseline, immediately post-test, and two weeks later. At post-test relative to controls and controlling for baseline scores, women randomly allocated to the scanner condition scored significantly higher on Body Areas Satisfaction and significantly lower on Self-classified Weight, and positive effects persisted two weeks beyond the experimental session. Results suggest that whole-body scanning may improve women’s body satisfaction and reduce perceived overweight relative to controls, though further research is necessary to examine the reliability of this effect and underlying mechanisms

Estado actual de la técnica y cuestiones perdurables en la recogida de datos antropométricos

The study of human body size and shape has been a topic of research for a very long time. In the past, anthropometry used traditional measuring techniques to record the dimensions of the human body and reported variance in body dimensions as a function of mean and standard deviation. Nowadays, the study of human body dimensions can be carried out more efficiently using three-dimensional body scanners, which can provide large amounts of anthropometric data more quickly than traditional techniques can. This paper presents a description of the broad range of issues related to the collection of anthropometric data using three-dimensional body scanners, including the different types of technologies available and their implications, the standard scanning process needed for effective data collection, and the possible sources of measurement errors that might affect the reliability and validity of the data collected.El estudio del tamaño y la forma del cuerpo humano ha sido un tema de investigación durante un tiempo muy largo. En el pasado, la antropometría utilizó técnicas de medición tradicionales para registrar las dimensiones del cuerpo humano y reportó la variación en las dimensiones del cuerpo en función de la media y la desviación estándar. Hoy en día, el estudio de las dimensiones del cuerpo humano se puede llevar a cabo utilizando maneras más eficientes, como los escáneres tridimensionales del cuerpo, que pueden proporcionar grandes cantidades de datos antropométricos más rápidamente que las técnicas tradicionales. En este trabajo se presenta una descripción de la amplia gama de temas relacionados con la recogida de datos antropométricos utilizando escáneres tridimensionales del cuerpo, incluyendo los diferentes tipos de tecnologías disponibles y sus implicaciones, el proceso de digitalización estándar necesario para la captura efectiva de datos, y las posibles fuentes de los errores de medición que podrán afectar la fiabilidad y validez de los datos recogidos.This work is financed by FEDER funds through the Competitive Factors Operational Program (COMPETE) POCI-01-0145-FEDER-007043 and POCI-01-0145FEDER-007136 and by national funds through FCT – the Portuguese Foundation for Science and Technology, under the projects UID/CEC/00319/2013 and UID/CTM/00264 respectively

Reliability Of The Styku 3d Whole Body Scanner For The Assessment Of Body Size In College Athletes

3-dimensional (3D) anthropometrics, such as volumes and surface area, have been shown to be important in predicting sport performance, and assessing health status, but most commercially available whole-body scanners are cost prohibitive. The main purpose of this study was to determine the test-retest reliability of a commercially available single camera 3D body scanning system to assess whole body and segmental circumferences, surface areas, and volumes of healthy collegiate athletes and students. Forty-nine male and female student-athletes active in various sports from a division I institute were scanned and measurements were analyzed. The single camera system demonstrated good within- and between-session reliability. Reliability was quantified as the systematic error, random error, and test-retest correlation. The Styku 3D whole body scanner demonstrated nearly perfect reliability. Systematic errors were negligible (mean standardized bias [95%CI]: within-session, 0.04 [0.02, 0.06]; between-session, 0.02 [0.01, 0.03]), random errors were negligible (mean standardized typical error [95%CI]); within-session, 0.14 [0.11, 0.17]; between-session, 0.09 [0.07, 0.13]), and test-retest correlations were nearly perfect (mean ICC [95%CI]: within-session, 0.98 [0.97, 0.99]; between-session, 0.99 [0.99, 1.00]). 3-D body scanning using a single camera system may be a good fit for professionals looking for a low-cost system for the evaluation of body shape and size

Quantitative Susceptibility Mapping: Contrast Mechanisms and Clinical Applications.

Quantitative susceptibility mapping (QSM) is a recently developed MRI technique for quantifying the spatial distribution of magnetic susceptibility within biological tissues. It first uses the frequency shift in the MRI signal to map the magnetic field profile within the tissue. The resulting field map is then used to determine the spatial distribution of the underlying magnetic susceptibility by solving an inverse problem. The solution is achieved by deconvolving the field map with a dipole field, under the assumption that the magnetic field is a result of the superposition of the dipole fields generated by all voxels and that each voxel has its unique magnetic susceptibility. QSM provides improved contrast to noise ratio for certain tissues and structures compared to its magnitude counterpart. More importantly, magnetic susceptibility is a direct reflection of the molecular composition and cellular architecture of the tissue. Consequently, by quantifying magnetic susceptibility, QSM is becoming a quantitative imaging approach for characterizing normal and pathological tissue properties. This article reviews the mechanism generating susceptibility contrast within tissues and some associated applications

A validation study of a Kinect based Body Imaging (KBI) device system based on ISO 20685:2010

To replace the traditional anthropometric data collection processes with the 3D acquiring system it is important that the validity of the data is not compromised. To do this, a validation study, based on the guideline of ISO 20685, can be performed. This paper presents the results of a comparison between traditional measurements and measurements taken with a 3D acquiring system using only four Kinect sensors. The results obtained were then compared with the maximum allowable error indicated in ISO 20685, concluding that this system cannot give sufficiently reliable data that can substitute the manual procedures.FEDER funds through the Competitive Factors Operational Program (COMPETE) and by national funds through FCT (Portuguese Foundation for Science and Technology) with the projects PEst- C/CTM/U10264 and ID/CEC/00319/201

A Comparison Of Direct And Indirect Assessments Of Standing Lumbar Lordosis In Asymptomatic Adults

Background: While lumbar lordosis is often indirectly (visually) assessed by practitioners to guide treatment, it is not clear how well direct and indirect assessments agree. The aims of this study were to (a) determine the intra- and inter-rater reliability of two indirect assessments (visual assessments of real and 3D body scanned people), and (b) determine the agreement between direct and indirect assessments (3D scan-extracted vs. visual assessments). Methods: Fifty asymptomatic participants were physically landmarked and scanned with and without landmarks using the Vitus Smart 3D whole body scanner, after which 10 practitioners visually assessed the lumbar lordosis of each participant. One week later, practitioners visually assessed the scanned images of the 50 participants plus 15 duplicates, and two weeks later, practitioners and participants again presented with practitioners repeating their visual assessments. Lumbar lordosis was also directly assessed from scan-extracted data. Cohenâs Kappa was used to determine the intra- and inter-rater reliability of indirect assessments, with polyserial correlation (ps) used to determine the agreement between direct and indirect assessments. Results: The intra- and inter-rater reliability of indirect assessments of real people was fair (ï« [95%CI]: 0.37 [0.20, 0.54]) and slight (ï« [95%CI]: 0.01 [â0.09, 0.11]), respectively. The intra- and inter-rater reliability of indirect assessments of scanned people was moderate (ï« [95%CI]: 0.56 [0.45, 0.67]) and slight (ï« [95%CI]: 0.13 [0.08, 0.19]), respectively. The agreement between direct and indirect assessment was moderate (ps=â0.41, p=0.04). Conclusion: Intra-rater reliability of indirect assessments of lumbar lordosis was fair to moderate, inter-rater reliability was slight, and the agreement between direct and indirect assessments was moderate. It appears that most of the error in indirect assessments is due to technical error, highlighting that efforts to improve reliability should focus on minimizing technical errors. 3D body scanning technology could be used as a training and teaching tool to improve measurement reliability

Focal Spot, Winter 2006/2007

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