A 3D Anthropometric Approach for Designing a Sizing System for Tight Fitting Garments

The purpose of this study is to investigate a new approach in creating sizing systems of wetsuits for the surfing industry. A good sizing system focusses on the balance between fit, comfort and functionality. The research provided a theoretical framework that assesses the natural body shape variations within a given user population. The focus is on gaining the highest level of coverage through determining the right body type classification. As a result digital mannequins are created that can serve as representation of body types associated with a specific apparel sizes.This research addresses the sizing of wetsuits for the European market. It incorporates the investigation of the full human torso and extremities. This study uses the 3D anthropometric data from the CAESAR project. The population contains 1255 Dutch and 801 Italian body scans. The population is filtered to gain an accurate representation of the surfer body types. Furthermore different methods are investigated in classification of body types considering the prioritization of different anthropometric dimensions. The resulting population is divided in groups that would be suitable for a specific wetsuit size. These populations are merged into average and extreme 3D mannequins that can be used in 3D apparel design software such as Clo3D or Optitex. These mannequins provide an accurate representation of specific wetsuit sizes and can be used to digitally asses the fit of the product. To make the mannequins suitable for 3D pattern drawing and flattening applications, the mannequins are reduced in size according to the desired tightness of a wetsuit. Current sizing charts on the market have been set up with the use of surveys and optimized based on customer feedback. It might not consider the entire population outside their current customer population. Furthermore these sizing charts are created based on one dimensional measurements and therefor do not capture the full shape of the human body. A new approach that uses 3D anthropometric data can give new insights in designing the right product dimensions for the highest sizing coverage. The use of 3D mannequins will increase the amount of anthropometric information that can be used in the apparel clothing industry. The approach is demonstrated on Italian and Dutch subjects and provides a good coverage for the European market. It can be trivially extended to other populations when the necessary data is available.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Applied Ergonomics and Desig

A machine learning approach to the design of customized shoe lasts

Applied Ergonomics and Desig

Pressure sensitivity for head, face and neck in relation to soft tissue

Pressure sensitivity research on the head, face, and neck is critical to develop ways to reduce discomfort caused by pressure in head-related products. The aim of this paper is to provide information for designers to be able to reduce the pressure discomfort by studying the relation between pressure sensitivity and soft tissue in the head, face and neck. We collected pressure discomfort threshold (PDT) and pressure pain threshold (PPT) from 119 landmarks (unilateral) for 36 Chinese subjects. Moreover, soft tissue thickness data on the head, face and neck regions of 50 Chinese people was obtained through CT scanning while tissue deformation data under the PDT and PPT states was obtained from literature. The results of the three-elements correlation analysis revealed that soft tissue thickness is positively correlated with deformation but not an important factor in pressure sensitivity. Our high-precision pressure sensitivity maps confirm earlier findings of more rough pressure sensitivity studies, while also revealing additional fine scale sensitivity differences. Finally, based on the findings, a high-precision "recommended map” of the optimal stress-bearing area of the head, face and neck was generated.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Human-Centered DesignApplied Ergonomics and Desig

DINED Mannequin

Designing products that closely interact with the human body can be quite challenging. Think for example about wearables like helmets, (Virtual Reality-) goggles, masks, garments, sports braces, or shoes. We are all unique individuals and this requires designers to carefully consider the great variety of human body shapes and come up with smart ways of accommodating this variety in such products through the use of sizing systems, adjustable parts, or flexible materials.We introduce ‘Mannequin’, a new tool for the DINED- platform. Through this tool, we want to make 3D anthropometry accessible for engineers, designers, and ergonomists by providing an intuitive interface for exploring 3D body shape variation and creating 3D design manikins. In the open data spirit of DINED, Mannequin can be freely used for both research and commercial purposes.Applied Ergonomics and DesignHuman-Centered Desig

Feature preserving non-rigid iterative weighted closest point and semi-curvature registration

Preserving features of a surface as characteristic local shape properties captured e.g. by curvature, during non-rigid registration is always difficult where finding meaningful correspondences, assuring the robustness and the convergence of the algorithm while maintaining the quality of mesh are often challenges due to the high degrees of freedom and the sensitivity to features of the source surface. In this paper, we present a non-rigid registration method utilizing a newly defined semi-curvature, which is inspired by the definition of the Gaussian curvature. In the procedure of establishing the correspondences, for each point on the source surface, a corresponding point on the target surface is selected using a dynamic weighted criterion defined on the distance and the semi-curvature. We reformulate the cost function as a combination of the semi-curvature, the stiffness, and the distance terms, and ensure to penalize errors of both the distance and the semi-curvature terms in a guaranteed stable region. For a robust and efficient optimization process, we linearize the semi-curvature term, where the region of attraction is defined and the stability of the approach is proven. Experimental results show that features of the local areas on the original surface with higher curvature values are better preserved in comparison with the conventional methods. In comparison with the other methods, this leads to, on average, 75\%, 8\% and 82\% improvement in terms of quality of correspondences selection, quality of surface after registration, and time spent of the convergence process respectively, mainly due to that the semi-curvature term logically increases the constraints and dependency of each point on the neighboring vertices based on the point's degree of curvature.Mechatronic DesignApplied Ergonomics and Desig

From an ellipsoid-based to an anthropomorphic articulated total body model for multibody applications

Human computer models represent a useful tool for investigating the human body response to external static/dynamic loads or for human-centred design. Articulated Total Body (ATB) models are the simplest human multibody models, where body segments are represented by ellipsoids joined at skeletal articulations. Over the years, regression models on both living subjects’ and cadavers’ data have been developed to predict body segments properties. These models are affected by two main limitations: the only inputs are the subject’s weight and height, not considering that for the same combination different morphologies can exist; secondly, regression analyses were performed over a specific population not including peculiar morphologies (under-weight or obese). A novel methodology for developing anthropomorphic ATB models is here presented: a statistical shape model able to predict the external geometry of the human body from a limited set of anthropometric measurements was implemented and body segments were obtained by segmentation; the respective inertial properties were computed from volumes, assuming a constant density value. The properties of this new anthropomorphic ATB model were compared to those calculated by GEBOD (Generator of Body Data), a well-known programme for ATB data calculation. A virtual population of twenty subjects was analysed: with reference to the inertial properties the most relevant differences occurred at the abdomen and the thighs segments (60% relative error), while the trunk, the shoulder and the calves represent the most critical areas for the geometry reconstruction (50 mm average error). The significance of these outcomes was investigated performing multibody simulations with various scenarios.Applied Ergonomics and DesignIndustrial Design Engineerin

A Comparison Between Representative 3D Faces Based on Bi- and Multi-variate and Shape Based Analysis

In Ergonomic product design, designers need to translate anthropometric data of the target population into product dimensions or sizing systems. Currently, sizing systems are often based on traditional anthropometric data and generally use the variation of one or two key body dimensions directly related to the product. For products that need to closely fit a certain part of the body it is relevant to incorporate multiple key dimensions. This can be realized by a multivariate approach such as a Principal Component Analysis. Over the past decades, there has been an increase in incorporating 3D imaging in anthropometric surveys. In order to integrate the use of 3D anthropometry in product sizing, representative models are used to visualize the variability of the target population. For the development of a ventilation mask for children, this study compares representative models of 3D faces based on a bivariate, multivariate and shape based analysis of 303 children's faces.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Applied Ergonomics and DesignIndustrial Desig

The effect of nasal shape on the thermal conditioning of inhaled air: Using clinical tomographic data to build a large-scale statistical shape model

In this paper, we investigate the heating function of the nasal cavity qualitatively, using a high-quality, large-scale statistical shape model. This model consists of a symmetrical and an asymmetrical part and provides a new and unique way of examining changes in nasal heating function resulting from natural variations in nasal shape (as obtained from 100 clinical CT scans). Data collected from patients suffering from different nasal or sinus-related complaints are included. Parameterized models allow us to investigate the effect of continuous deviations in shape from the mean nasal cavity. This approach also enables us to avoid many of the compounded effects on flow and heat exchange, which one would encounter when comparing different patient-specific models. The effects of global size, size-related features, and turbinate size are investigated using the symmetrical shape model. The asymmetrical model is used to investigate different types of septal deviation using Mladina's classification. The qualitative results are discussed and compared with findings from the existing literature.Accepted Author ManuscriptApplied Ergonomics and Desig

Advancing Analysis Techniques for Plantar Pressure Videos via Open-Access Contributions

While dynamic plantar pressure measurements are commonly used for clinical evaluation of gait-related problems, computational analysis techniques for these datasets are few and farbetween. To address this issue, we introduce an open-access database of plantar pressure videos for researchers to develop algorithms around.Applied Ergonomics and Desig

An assessment of the information lost when applying data reduction techniques to dynamic plantar pressure measurements

Data reduction techniques are commonly applied to dynamic plantar pressure measurements, often prior to the measurement's analysis. In performing these data reductions, information is discarded from the measurement before it can be evaluated, leading to unkonwn consequences. In this study, we aim to provide the first assessment of what impact data reduction techniques have on plantar pressure measurements. Specifically, we quantify the extent to which information of any kind is discarded when performing common data reductions. Plantar pressure measurements were collected from 33 healthy controls, 8 Hallux Valgus patients, and 10 Metatarsalgia patients. Eleven common data reductions were then applied to the measurements, and the resulting datasets were compared to the original measurement in three ways. First, information theory was used to estimate the information content present in the original and reduced datasets. Second, principal component analysis was used to estimate the number of intrinsic dimensions present. Finally, a permutational multivariate ANOVA was performed to evaluate the significance of group differences between the healthy controls, Hallux Valgus, and Metatarsalgia groups. The evaluated data reductions showed a minimum of 99.1% loss in information content and losses of dimensionality between 20.8% and 83.3%. Significant group differences were also lost after each of the 11 data reductions (α=0.05), but these results may differ for other patient groups (especially those with highly-deformed footprints) or other region of interest definitions. Nevertheless, the existence of these results suggest that the diagnostic content of dynamic plantar pressure measurements is yet to be fully exploited.Applied Ergonomics and Desig