Correspondence Preserving Elastic Surface Registration with Shape Model Prior

BackgroundOne of the most consistently reported brain abnormalities in schizophrenia (SCZ) is decreased volume and shape deformation of the hippocampus. However, the potential contribution of chronic antipsychotic medication exposure to these phenomena remains unclear.MethodWe examined the effect of chronic exposure (8 weeks) to clinically relevant doses of either haloperidol (HAL) or olanzapine (OLZ) on adult rat hippocampal volume and shape using ex vivo structural MRI with the brain retained inside the cranium to prevent distortions due to dissection, followed by tensor-based morphometry (TBM) and elastic surface-based shape deformation analysis. The volume of the hippocampus was also measured post-mortem from brain tissue sections in each group.ResultsChronic exposure to either HAL or OLZ had no effect on the volume of the hippocampus, even at exploratory thresholds, which was confirmed post-mortem. In contrast, shape deformation analysis revealed that chronic HAL and OLZ exposure lead to both common and divergent shape deformations (q = 0.05, FDR-corrected) in the rat hippocampus. In particular, in the dorsal hippocampus, HAL exposure led to inward shape deformation, whereas OLZ exposure led to outward shape deformation. Interestingly, outward shape deformations that were common to both drugs occurred in the ventral hippocampus. These effects remained significant after controlling for hippocampal volume suggesting true shape changes.ConclusionsChronic exposure to either HAL or OLZ leads to both common and divergent effects on rat hippocampal shape in the absence of volume change. The implications of these findings for the clinic are discussed.

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“…The shape analysis pipeline has been reported previously (Danckaers et al 2014) and is depicted in Fig. 2 a .…”

Section: Methodsmentioning

confidence: 99%

Chronic exposure to haloperidol and olanzapine leads to common and divergent shape changes in the rat hippocampus in the absence of grey-matter volume loss

et al. 2016

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“…The flow-chart of this framework is illustrated in Figure 1. First, from a population of 3D human body shapes, an SSM is built (Danckaers et al 2014). Next, the appearance of every shape is modified so that its new features are equal to those of the average shape.…”

Section: Methodsmentioning

confidence: 99%

“…From the set of shapes with low identity, a new SSM is built (Danckaers et al 2014) that represents a posture model. The result is a posture model, whose variances are mainly the posture variances that are present inside the population.…”

Section: Identity Removalmentioning

confidence: 99%

Posture normalisation of 3D body scans

et al. 2019

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For product developers that design near-body products, virtual mannequins that represent realistic body shapes, are valuable tools. With statistical shape modeling, the variability of such body shapes can be described. Shape variation captured by statistical shape models (SSMs) is often polluted by posture variations, leading to less compact models. In this paper, we propose a framework that has low computational complexity to build a posture invariant SSM, by capturing and correcting the posture of an instance. The posture-normalized SSM is shown to be substantially more compact than the non-posture-normalized SSM.

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“…at the tips of the nose or eyes, see Figure 1. Secondly, a landmark preserving correspondence between each of these 3D scans is constructed by either a conformal mapping from a parameter domain (41) or by registering each 3D scan onto a template model (42). Each shape can thus be represented as a large but fixed number of points or vertexes, say ((x 1 ,y 1 ,z 1 ), (x 2 ,y 2 ,z 2 ), ..., (x M ,y M ,z M )), concatenated such that respective points (x i ,y i ,z i ) and (x' i ,y' i ,z' i ) of any two shapes correspond.…”

Section: Enriched Statistical Shape Models: From 1d To 3d Anthropometrymentioning

confidence: 99%

A new data structure and workflow for using 3D anthropometry in the design of wearable products

Verwulgen

Lacko

Vleugels

et al. 2018

International Journal of Industrial Ergonomics

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Abstract.The human body is a complex biomechanical system that exhibits many variations. Wearable products should be both functional and comfortable. They require a close and accurate fit to the body of the end-user. Current approaches to design body near products rely on 1D anthropometry and unrealistic manikins, e.g. constructed from simple surfaces such as spheres and cylinders connected by splines. With the uprising of 3D scanning, a myriad of accurate 3D body models becomes available. In this paper we present a framework to use this 3D shape information in the development of wearable products. The key concept that we introduce to achieve this extension, is an enriched shape model: a statistical shape model of the human body that also contains all 1D anthropometric data in it. With enriched shape models, a 3D shape can be parameterized with a given set of anthropometric features. Thus the dense geometric information of an individual's shape can be obtained simply by tuning that individual's anthropometric values. By designing on the generated 3D surface, a product can be obtained that closely fits the individual's shape. We thus extend the method of linking 1D anthropometric data with the dimensions of a product. This results in three design strategies that link both body shape with product geometry: design for collective fit, design for fit within clusters and design for individual fit. Each strategy is explained and studied with the design of wearable EEG headsets that fits the human head. KeywordsMass-customization, EEG headsets, CAD, parameterized design, 3D anthropometry, statistical shape models Relevance to Design PracticeWe present a workflow to use accurate 3D shape models of the human body in the design of products that should closely fit the end-user. To that end, we introduce enriched shape models: a new data structure that contains all dense geometric shape information together with classical anthropometric data. We illustrate how enriched shape models can be used to achieve products with personalized fit, as an extension to the use of univariate anthropometric data. The use of enriched shape models for personalized design could become an important driver for mass customization. To that end, tools and techniques should be developed to incorporate the presented workflow in CAD/CAM.

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Correspondence Preserving Elastic Surface Registration with Shape Model Prior

Cited by 36 publications

References 12 publications

Chronic exposure to haloperidol and olanzapine leads to common and divergent shape changes in the rat hippocampus in the absence of grey-matter volume loss

Chronic exposure to haloperidol and olanzapine leads to common and divergent shape changes in the rat hippocampus in the absence of grey-matter volume loss

Posture normalisation of 3D body scans

A new data structure and workflow for using 3D anthropometry in the design of wearable products

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