43 research outputs found
Application of 3D scanning in design education
No full textThree-dimensional scanning technologies have brought great opportunities in ergonomic and product design education as well as research. Not only the anthropometric size but also the shape and posture of the human, form of a product, or interactions between the human and product obtained based on the 3D scanning have been usefully applied in product design. This chapter introduces a number of educational and research cases, which have been performed at the Faculty of Industrial Design Engineering at Delft University of Technology. First, as ergonomics plays a big role in the product design process, but in a different and advanced way than before, we have broadly applied the emerging 3D scanning technology in our design education and research. Because the topic of “ergonomic design based on 3D scanning” have been taught in our education, the number of students who are using 3D human scans for their course work and/or graduate project has increased considerably. Some of our successful cases will be introduced in this chapter. Second, from the 3D scanning practices in our education, we concluded there is a need of a 3D scanner, especially for the human hand, that is both quick and accurate but is also capable of scanning parts that are normally hard to cover. Multiple final master projects have contributed to the development of a working prototype of an accurate and low-cost 3D hand scanner. Finally, based on our experience, techniques, methods, software, and relevant information that can support design education based on 3D human scans will be discussed.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 DesignMechatronic DesignIndustrial Desig
Simulation-based multi-objective optimization combined with a DHM tool for occupant packaging design
No full textOccupant packaging design is usually done using computer-aided design (CAD) and digital human modelling (DHM) tools. These tools help engineers and designers explore and identify vehicle cabin configurations that meet accommodation targets. However, studies indicate that current working methods are complicated and iterative, leading to time-consuming design procedures and reduced investigations of the solution space, in turn meaning that successful design solutions may not be discovered. This paper investigates potential advantages and challenges in using an automated simulation-based multi-objective optimization (SBMOO) method combined with a DHM tool to improve the occupant packaging design process. Specifically, the paper studies how SBMOO using a genetic algorithm can address challenges introduced by human anthropometric and postural variability in occupant packaging design. The investigation focuses on a fabricated design scenario involving the spatial location of the seat and steering wheel, as well as seat angle, taking into account ergonomics objectives and constraints for various end-users. The study indicates that the SBMOO-based method can improve effectiveness and aid designers in considering human variability in the occupant packaging design process.CC BY 4.0Corresponding author: E-mail address: [email protected] (E. Perez Luque).This work has been made possible with support from the Knowledge Foundation in Sweden in the ADOPTIVE project, VF-KDO project, and by the participating organisations. This support is gratefully acknowledged.</p
Neck postural stabilization, motion comfort, and impact simulation
No full textThe human head-neck system requires continuous muscular stabilization in the presence of gravity and trunk motion. This chapter presents experimental and modeling efforts, applying mechanical perturbations to seated subjects, evaluating trunk and head motion, to investigate postural stabilization.A detailed multisegment neck model has been developed including vestibular/visual and muscular feedback loops and cocontraction. Dynamic validation is presented in the frequency domain in all six motion directions. The neck model captures primary motion responses and interaction terms such as head rotation in response to seat translation. Results show major contributions of vestibular/visual feedback stabilizing the head in space while muscular feedback stabilizes the head on the torso. In addition, muscular feedback is essential to stabilize the individual vertebral joints and prevent neck buckling. The contribution of cocontraction is estimated to be minor in the neck. Validation in impact conditions shows that postural control parameters estimated that fitting the model to small-amplitude experimental data can predict postural responses in high-amplitude loading conditions reasonably well.This manuscript focuses on the neck but also includes experiments with combined stabilization of the complete spine, measuring trunk and head motion, with a perspective toward full spine and full-body modeling. Lumbar stabilization has been captured using a simplified model by assuming a virtual pivot around L4/L5. The model uniquely separates stabilizing contributions of intrinsic stiffness and damping (including muscle cocontraction) and muscle feedback (length, velocity, and acceleration). The model parameters allowed us to estimate the relative contributions of intrinsic and reflexive stabilization and showed intrinsic contributions, similar to or larger than reflexive contributions in lumbar stabilization with horizontal perturbations to the trunk or pelvis. Experiments with a rotating pelvis showed relevant contributions of vestibular and visual feedback, which are more effective to minimize head than trunk rotation.A full-body human model with multisegment spine was previously validated for impact and vertical vibration. Integrating the new detailed neck model in the full-body human model will enable simulation of full-body vibration and impact scenarios with realistic compliant seat models. Further experiments and modeling efforts will aim to capture sensory integration of visual and vestibular motion perceptions in relation to posture maintenance and motion sickness.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.Intelligent VehiclesBiomechatronics & Human-Machine Contro
Digital holographic microscopy applied to measurement of a flow in a T-shaped micromixer
No full textIn this paper, we describe measurements of a three-dimensional (3D) flow in a T-shaped micromixer by means of digital holographic microscopy. Imaging tracer particles in a microscopic flow with conventional microscopy is accompanied by a small depth-of-field, which hinders true volumetric flow measurements. In holographic microscopy, the depth of the measurement domain does not have this limitation because any desired image plane can be reconstructed after recording. Our digital holographic microscope (DHM) consists of a conventional in-line recording system with an added magnifying optical element. The measured flow velocity and the calculated vorticity illustrate four streamwise vortices in the micromixer outflow channel. Because the investigated flow is stationary and strongly 3D, the DHM performance (i.e. accuracy and resolution) can be precisely investigated. The obtained Dynamic spatial range and Dynamic velocity range are larger than 20 and 30, respectively. High-speed multiple-frame measurements illustrate the capability to simultaneously track about 80 particles in a volumetric measurement domain.Process and EnergyMechanical, Maritime and Materials Engineerin
In situ observation of tricalcium aluminate dissolution in water
No full textThe nanoscale dissolution flux of tricalcium aluminate (C3A) in flowing water is characterized in situ by Digital Holographic Microscopy (DHM). The pure dissolution of C3A in flowing water with a flow rate of 34 ml·min-1 before the precipitation of hydrated phases only lasted about one quarter of a second, and the pure dissolution rate mostly falls in the range of 500 ~ 1500 μmol·m-2·s-1. Subsequently, foil shape hydration product formed and rapidly covered the surface of C3A, leading to the dramatic decrease of the overall dissolution rate to 55 ± 10 μmol·m-2·s-1
Targeting positive modulation and inhibition of ethanol-induced GABAA receptor potentiation as a novel mechanism for alcohol use disorder
No full textAlcohol use disorder (AUD) is the most common substance use disorder (SUD) giving rise to major socioeconomic and health consequences, with an estimated 208 million people affected worldwide. Current pharmacotherapies are minimally ineffective, and none target the direct neurological effects of ethanol. To identify promising pharmacological approaches for the treatment of AUD, understanding of the complex psychophysiological influences of SUD is necessary. Thus, we first review psychophysiological aspects of SUD, including a brief review of the brain disease model of addiction and the psychophysiological overlap between SUD and obsessive-compulsive disorder (OCD). We expand on the preoccupation stage of the addiction, proposing a hypothesis where substance use can become the obsessive focus in those with underlying obsessive-compulsive pathology, leading to development of SUD. Utilizing this hypothesis, and drawing upon efficacy of OUD treatments, we then provide insight and suggestions for future directions for AUD treatments and pharmacological interventions.
In agreement with the suggested AUD pharmacotherapy approaches, we have identified dihydromyricetin (DHM), a natural flavonoid, to be a promising starting point towards the development of a novel and effective pharmacological mechanism for AUD treatment, that is more in line with those currently available for OUD. DHM has been shown to counteract major neurological effects of ethanol, reduce voluntary ethanol intake, and provide anxiolytic effects through mutually exclusive binding with flumazenil, a GABAAR allosteric modulator. Despite this promising activity, DHM lacks druglike properties, leading to poor CNS exposure and thus limiting clinical utility. Thus, medicinal chemistry efforts are necessary to address the structural limitations of DHM. Further, as flavonoids are known to have non-specific bioactivities, towards which bioactive metabolites often contribute, exploring the specificity, and druggable potential of DHM bioactivity is necessary.
First, we investigated the serum and brain exposure to DHM and metabolites associated with acute anti-intoxicating effects in mice. We found intraperitoneal (IP) administration of DHM 50 mg/kg to be effective at reducing acute ethanol-induced loss of righting reflex (LORR), with these effects limited by rapid serum and brain clearance. Next, we synthesized multiple dihydromyricetin derivatives and assessed intrinsic GABAAR activity, with the aim of determining structure activity relationship (SAR) and enhancing druglike properties. This enabled us to identify 4H-1-Benzopyran-4-one, 2-(3,4-dihydroxy-5-methoxyphenyl)-2,3-dihydro-3,5,7-trihydroxy and 4H-1-Benzopyran-4-one, and 2-(3,4-dihydroxy-5-methoxyphenyl)-2,3-dihydro-3,5,7-trihydroxy, respectively) to be GABAAR active metabolites. Notably, this work enabled us to discover a novel druglike, dihydromyricetin derivative (RU-EC2-52) that is a GABAAR positive allosteric modulator (PAM). Molecular modeling studies (MOE® software) in the benzodiazepine binding site of human GABAAR Cryo-EM structure provided insight into key DHM GABAAR interactions, largely correlating with SAR findings. Combined, these results support the potential of DHM’s mechanism at counteracting neurological effects of high doses of ethanol, provide insight into potential GABAAR active metabolites, and identify RU-EC2-52 to be a promising, druglike GABAAR PAM.Ph.D.Includes bibliographical reference
Digital monoplotting
No full textThe subject of this thesis is to establish a system for digital monoplotting on behalf of the Dutch Topographic Service. For this purpose a computer program has been written. Digital monoplotting is a system for updating digital data bases by means of single aerial photographs. The method implies the use of a digital height model (DHM) and a second goal of the thesis is to specify its requirements and describe its construction.Civil Engineering and Geoscience
The effects of storage conditions on long-chain polyunsaturated fatty acids, lipid mediators, and antioxidants in donor human milk – a review
No full textDonor human milk (DHM) is the preferred alternative for feeding infants, if maternal milk is not available. However, extensive storage and processing of DHM may negatively affect the composition. Currently safety measures predominantly consider microbiological aspects, and with the increasing demand for DHM in neonatal units due to greater survival of extremely preterm infants it is imperative to prioritise nutritional quality. This review summarises current evidence of the effects of storage and processing conditions on total fat, long-chain polyunsaturated fatty acids, lipid mediators and antioxidant content of DHM. Based on the available evidence, it is recommended that storage time is minimised, and DHM kept in light protected bottles. Storage at 4°C should be avoided whenever possible, with storage at 80°C prior to pasteurisation being preferential. Further research is needed to evaluate the effects of long term storage at 20°C, and the impact of storage conditions on lipid mediators. © 2019, Elsevier. The attached document (embargoed until 13/07/2020) is an author produced version of a paper published in PROSTAGLANDINS, LEUKOTRIENES AND ESSENTIAL FATTY ACIDS uploaded in accordance with the publisher’s self- archiving policy. The final published version (version of record) is available online at the link. Some minor differences between this version and the final published version may remain. We suggest you refer to the final published version should you wish to cite from it
Posture normalisation of 3D body scans
No full textFor product developers that design near-body products, virtual mannequins that represent realistic body shapes, are valuable tools. With statistical shape modelling, 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-normalised SSM is shown to be substantially more compact than the non-posture-normalised SSM. Practitioner summary: Statistical shape modelling is a technique to map out the variability of (body) shapes. This variability is often polluted by variations in posture. In this paper, we propose a framework to build a posture invariant statistical shape model. Abbreviations: SSM: statistical shape model; 1D: one-dimensional; 3D: three-dimensional; DHM: digital human model; LBS: linear blend skinning; PCA: princial component analysis; PC: principal component; TTR: thumb tip reach.Accepted author manuscriptApplied Ergonomics and Desig
A Human-Centered Design Procedure for Conceptualization Using Virtual Reality Prototyping Applied in an Inflight Lavatory
No full textFor designing large-scale products like an airplane, engaging end-users in the concept phase is difficult. However, early user evaluation is important to choose the path which fits the user’s needs best. In particular, comfort-related assessments are difficult to conduct with digital models that are shown on a desktop PC application. Digital Human Modelling (DHM) plays a role in postural comfort analysis, while the subjective comfort feedback still largely relied on consulting with end-users. This paper applies a human-centered design process and analyses the advantages and disadvantages of using VR prototypes for involving users during concept design. This study focused on using VR prototypes for concept selection and verification based on comfort assessment with potential end-users. The design process started with an online questionnaire for identifying the quality of the design elements (Step 1 online study). Then, alternative concepts were implemented in VR, and users evaluated these concepts via a VR headset (Step 2 Selection study). Finally, the research team redesigned the final concept and assessed it with potential users via a VR headset (Step 3 Experience study). Every design element contributed positively to the long-haul flight comfort, especially tap-basin height, storage, and facilities. The male and female participants had different preferences on posture, lighting, storage, and facilities. The final prototype showed a significantly higher comfort rate than the original prototypes. The first-person immersion in VR headsets helps to identify the nuances between concepts, thus supports better decision-making via collecting richer and more reliable user feedback to make faster and more satisfying improvements.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 DesignMechatronic DesignMaterials and Manufacturin
