A Methodology to Create 3D Body Models in Motion

[EN] Size, shape and posture are fundamental features of digital human models (DHM) to obtain accurate virtual simulations of the ergonomics of products and environments. Research on 3D body scanning, processing and modelling have enabled the generation of avatars representing specific populations and morphotypes in standing and seated postures being the basis to define size and shape of DHM. Posture is implemented with biomechanical models of the human movement. Most of the research is focused on posture control and movement tracking to analyze the variability in different contexts (e.g. driving, performing a working task). Motion capture technology used for this purpose, requires a limited number of sensors or reflective markers attached to the body according to the definition of body segments. 3D body scanning and motion capture are both technologies currently used to analyze human body shape and biomechanics to apply it to enhance digital human models. These technologies may converge on the so-called temporal 3D scanners or 4D scanners, a new technology recently developed to scan the body in motion. With this technology, it is possible to obtain sequences of dense 3D point clouds representing the movement of the body. In this paper, a novel methodology to create realistic 3D body models in motion is proposed. This method is supported by a new 4D scanning system (Move 4D) and a data driven-model. Move4D is a modular photogrammetry-based 4D scanning system. It consists of a set of 12 synchronized modules to scan full bodies with texture in motion. It can capture up to 180 fps with a resolution of 2 mm. The algorithms have been conceived and optimized to automatically process the series of raw point clouds captured. They rely on a data-driven body model including shape, pose and soft-tissue deformation trained with a large database and a deep learning model. The process is fully automatic and does not require any interactive landmarking or revision. The 3D outcome of this methodology is one noise-and artefact-free watertight mesh per frame and a model of shape, pose and soft-tissue that can be rigged with a 23-joint skeleton. This type of outcome permits their use for many applications such as simulations, augmented and virtual reality (AR/VR) or biomechanical analysis purposes.The research presented in this paper have been developed within the projects IMDEEA/2020/85 and MDEEA/2020/87. Funding requested to Instituto Valenciano de Competitividad Empresarial (IVACE), call for proposals 2020 for Technology Centers of the Comunitat Valenciana, co-funded by ERDF Funds, EU Operational Program of the Comunitat Valenciana 2014-2020.Parrilla Bernabé, E.; Ruescas, A.; Solves, J.; Ballester Fernandez, A.; Nacher Fernandez, B.; Alemany Mut, MS.; Garrido Jaen, JD. (2020). A Methodology to Create 3D Body Models in Motion. Springer. 309-314. https://doi.org/10.1007/978-3-030-51064-0_39S309314Scataglini, S., Paul, G.: DHM and Posturography. Academic Press, London (2019)Zakaria, N., Gupta, D.: Anthropometry, Apparel Sizing and Design. Woodhead Publishing, Cambridge (2019)Liberadzki, P., Adamczyk, M., Witkowski, M., Sitnik, R.: Structured-light-based system for shape measurement of the human body in motion. Sensors 18, 2827 (2018). https://doi.org/10.3390/s18092827Parrilla, E., Ballester, A., Parra, P., Ruescas, A., Uriel, J., Garrido, D., Alemany, S.: MOVE 4D: accurate high-speed 3D body models in motion. In: Proceedings of 3DBODY.TECH 2019, Lugano, Switzerland, 22–23 October 2019, pp. 30–32 (2019). https://doi.org/10.15221/19.03

Micro Fourier Transform Profilometry (μ\muFTP): 3D shape measurement at 10,000 frames per second

Recent advances in imaging sensors and digital light projection technology have facilitated a rapid progress in 3D optical sensing, enabling 3D surfaces of complex-shaped objects to be captured with improved resolution and accuracy. However, due to the large number of projection patterns required for phase recovery and disambiguation, the maximum fame rates of current 3D shape measurement techniques are still limited to the range of hundreds of frames per second (fps). Here, we demonstrate a new 3D dynamic imaging technique, Micro Fourier Transform Profilometry ($\mu$FTP), which can capture 3D surfaces of transient events at up to 10,000 fps based on our newly developed high-speed fringe projection system. Compared with existing techniques, $\mu$FTP has the prominent advantage of recovering an accurate, unambiguous, and dense 3D point cloud with only two projected patterns. Furthermore, the phase information is encoded within a single high-frequency fringe image, thereby allowing motion-artifact-free reconstruction of transient events with temporal resolution of 50 microseconds. To show $\mu$FTP's broad utility, we use it to reconstruct 3D videos of 4 transient scenes: vibrating cantilevers, rotating fan blades, bullet fired from a toy gun, and balloon's explosion triggered by a flying dart, which were previously difficult or even unable to be captured with conventional approaches.Comment: This manuscript was originally submitted on 30th January 1

Optical techniques for 3D surface reconstruction in computer-assisted laparoscopic surgery

One of the main challenges for computer-assisted surgery (CAS) is to determine the intra-opera- tive morphology and motion of soft-tissues. This information is prerequisite to the registration of multi-modal patient-specific data for enhancing the surgeon’s navigation capabilites by observ- ing beyond exposed tissue surfaces and for providing intelligent control of robotic-assisted in- struments. In minimally invasive surgery (MIS), optical techniques are an increasingly attractive approach for in vivo 3D reconstruction of the soft-tissue surface geometry. This paper reviews the state-of-the-art methods for optical intra-operative 3D reconstruction in laparoscopic surgery and discusses the technical challenges and future perspectives towards clinical translation. With the recent paradigm shift of surgical practice towards MIS and new developments in 3D opti- cal imaging, this is a timely discussion about technologies that could facilitate complex CAS procedures in dynamic and deformable anatomical regions

Preliminary Investigation of the Frictional Response of Reptilian Shed Skin

Developing deterministic surfaces relies on controlling the structure of the rubbing interface so that not only the surface is of optimized topography, but also is able to self-adjust its tribological behaviour according to the evolution of sliding conditions. In seeking inspirations for such designs, many engineers are turning toward the biological world to correlate surface structure to functional behavior of bio-analogues. From a tribological point of view, squamate reptiles offer diverse examples where surface texturing, submicron and nano-scale features, achieve frictional regulation. In this paper, we study the frictional response of shed skin obtained from a snake (Python regius). The study employed a specially designed tribo-acoustic probe capable of measuring the coefficient of friction and detecting the acoustical behavior of the skin in vivo. The results confirm the anisotropy of the frictional response of snakes. The coefficient of friction depends on the direction of sliding: the value in forward motion is lower than that in the backward direction. In addition it is shown that the anisotropy of the frictional response may stem from profile asymmetry of the individual fibril structures present within the ventral scales of the reptil

The coupling of action and perception in musical meaning formation

The embodied perspective on music cognition has stressed the central role of the body and body move- ments in musical meaning formation processes. In the present study, we investigate by means of a behavioral experiment how free body movements in response to music (i.e., action) can be linked to specific linguistic, metaphorical descriptions people use to describe the expressive qualities they perceive in the music (i.e., per- ception). We introduce a dimensional model based on the Effort/Shape theory of Laban in order to target musical expressivity from an embodied perspective. Also, we investigate whether a coupling between action and perception is dependent on the musical background of the participants (i.e., trained versus untrained). The results show that the physical appearance of the free body movements that participants perform in response to music are reliably linked to the linguistic descriptions of musical expressiveness in terms of the underlying quality. Moreover, this result is found to be independent of the participants’ musical background

Radar and RGB-depth sensors for fall detection: a review

This paper reviews recent works in the literature on the use of systems based on radar and RGB-Depth (RGB-D) sensors for fall detection, and discusses outstanding research challenges and trends related to this research field. Systems to detect reliably fall events and promptly alert carers and first responders have gained significant interest in the past few years in order to address the societal issue of an increasing number of elderly people living alone, with the associated risk of them falling and the consequences in terms of health treatments, reduced well-being, and costs. The interest in radar and RGB-D sensors is related to their capability to enable contactless and non-intrusive monitoring, which is an advantage for practical deployment and users’ acceptance and compliance, compared with other sensor technologies, such as video-cameras, or wearables. Furthermore, the possibility of combining and fusing information from The heterogeneous types of sensors is expected to improve the overall performance of practical fall detection systems. Researchers from different fields can benefit from multidisciplinary knowledge and awareness of the latest developments in radar and RGB-D sensors that this paper is discussing