After a variable SOA a peripheral target appeared and participants were asked either to touch it if it was a real word (go-trials) or to stay still if it was a pseudo-word (no-go trials; see Methods ...for more details). After a variable delay (stimulus onset asynchrony; SOA) a peripheral target appeared and participants were asked either to touch it, if it was printed in green (go-trials) or to stay still if it was printed in red (no-go trials; see Methods for more details). https://doi.org/10.1371/journal.pone.0104349.g002 1.
Ziel der ArbeitAls Grundlage für alters- und geschlechtsbezogene Orientierungswerte der körperlichen Belastbarkeit werden für Arbeitsschutz und menschengerechte Arbeitsgestaltung die körperlichen ...Leistungsvoraussetzungen für verschiedene Arbeitsanforderungen dargestellt. Dies gliedert sich inhaltlich in drei aufeinanderfolgende Teile: Teil 1 – Einführung und Methodik sowie Daten zum Körperbau und zur Belastbarkeit des Skelett-Systems, Teil 2 – Daten zu Körperkräften und Teil 3 – Daten zur kardiopulmonalen und energetischen Leistungsfähigkeit sowie gemeinsame Schlussfolgerungen aus allen drei Teilen.Material und MethodenZur Darstellung der alters- und geschlechtsbezogenen Körperkräfte konnten 9 Literaturquellen herangezogen werden. Es überwiegen Angaben zu isometrischen Maximalkräften, ausgeübt durch das Hand-Arm-System, deren Aussagen für die berufliche Leistungsfähigkeit nicht direkt mit denen zur Kraftausdauer übereinstimmen.Ergebnisse und DiskussionMaximalkräfte bleiben zunächst etwa konstant und vermindern sich erst nach dem 50. Lebensjahr, wobei sich diese Abnahme nach dem 60. Lebensjahr beschleunigt. Maximalkräfte sind von der individuellen Konstitution abhängig, wie sich am Beispiel der Beziehung zur Körperhöhe zeigen lässt. Geschlechtsunterschiede liegen hier bei Frauen um ca. 60 % gegenüber den Männern. Die Kraftausdauer verändert sich im Verhältnis zur Maximalkraft bei älteren Personen eher zu deren Vorteil: Bezogen auf die sinkende Maximalkraft ist die Ermüdung durch isometrische und rhythmische Kontraktionen bei Älteren relativ geringer. Die für viele berufliche Tätigkeiten eher relevante dynamische Kraftausdauer vermindert sich bereits ab dem 40. Lebensjahr. Eine gemeinsame Zusammenfassung der drei Teile folgt am Ende des Teils 3 dieser Publikationsreihe.
Prosthetic arms controlled by a brain-computer interface can enable people with tetraplegia to perform functional movements. However, vision provides limited feedback because information about ...grasping objects is best relayed through tactile feedback. We supplemented vision with tactile percepts evoked using a bidirectional brain-computer interface that records neural activity from the motor cortex and generates tactile sensations through intracortical microstimulation of the somatosensory cortex. This enabled a person with tetraplegia to substantially improve performance with a robotic limb; trial times on a clinical upper-limb assessment were reduced by half, from a median time of 20.9 to 10.2 seconds. Faster times were primarily due to less time spent attempting to grasp objects, revealing that mimicking known biological control principles results in task performance that is closer to able-bodied human abilities.
Workers in a number of different occupational sectors are exposed to workplace vibration on a daily basis. This exposure may arise through the use of powered-hand tools or hand-transmitted vibration ...(HTV). Workers might also be exposed to whole body vibration (WBV) by driving delivery vehicles, earth moving equipment, or through use of tools that generate vibration at low dominant frequencies and high amplitudes, such as jackhammers. Occupational exposure to vibration has been associated with an increased risk of musculoskeletal pain in the back, neck, hands, shoulders, and hips. Occupational exposure may also contribute to the development of peripheral and cardiovascular disorders and gastrointestinal problems. In addition, there are more recent data suggesting that occupational exposure to vibration may enhance the risk of developing certain cancers. The aim of this review is to provide an assessment of the occupations where exposure to vibration is most prevalent, and a description of the adverse health effects associated with occupational exposure to vibration. This review will examine (1) various experimental methods used to measure and describe the characteristics of vibration generated by various tools and vehicles, (2) the etiology of vibration-induced disorders, and (3) how these data were employed to assess and improve intervention strategies and equipment that reduces the transmission of vibration to the body. Finally, there is a discussion of the research gaps that need to be investigated to further reduction in the incidence of vibration-induced illnesses and injuries.
During the weaning period, infants are not skilled at self-feeding and caregivers play a prominent role in feeding. Therefore, solid feeding is an inherently collaborative and interactive process ...between caregivers and infants. The present study examined how caregivers and infants coordinate to construct solid feeding interactions, as an analysis of naturalistic longitudinal observations of three Japanese motherainfant dyads. The main results were as follows. After 2 or 3 months post-weaning, mothersa arm movements became non-fluid while feeding children. This non-fluidity was associated with rapid changes in the movement patterns of the mother's arms and the child's mouth. Compared to the development of children's mouth movements, mothersa arm movements developed quickly. This imbalance in the pace of change may have been one cause of non-fluency. While feeding, even though mothers did not eat the children's food, they frequently moved their mouths as if they were eating. The frequency of this maternal behavior differed according to their feeding styles, and mothersa movement patterns corresponded well with their babiesa mouth movements. These findings clarify the importance of mothersa eating-like mouth movements for the weaning process.
Interventional C-arm imaging is crucial to percutaneous orthopedic procedures as it enables the surgeon to monitor the progress of surgery on the anatomy level. Minimally invasive interventions ...require repeated acquisition of X-ray images from different anatomical views to verify tool placement. Achieving and reproducing these views often comes at the cost of increased surgical time and radiation. We propose a marker-free ‘technician-in-the-loop’ Augmented Reality (AR) solution for C-arm repositioning. The X-ray technician operating the C-arm interventionally is equipped with a head-mounted display system capable of recording desired C-arm poses in 3D via an integrated infrared sensor. For C-arm repositioning to a target view, the recorded pose is restored as a virtual object and visualized in an AR environment, serving as a perceptual reference for the technician. Our proof-of-principle findings from a simulated trauma surgery indicate that the proposed system can decrease the 2.76 X-ray images required for re-aligning the scanner with an intra-operatively recorded C-arm view down to zero, suggesting substantial reductions of radiation dose. The proposed AR solution is a first step towards facilitating communication between the surgeon and the surgical staff, improving the quality of surgical image acquisition, and enabling context-aware guidance for surgery rooms of the future.
Introduction: The surgery success depends on the information, knowledge, experience and capabilities of the surgeon's precision motion. Leaving in the hands and brain of the surgeon the guide and ...decision on the telemanipulator are examples of artificial organs dedicated to specific tasks. Mini-invasive surgery provides poorer, less intrusive information, often only visual observation of the field operations. Telemanipulators thanks to that between the hand surgeon and a tool inside a patient's body is a computer - you can create a technology and technical methods and decision support systems to improve precision for the task (removing tremors hand, scaling of movement). Objectives: This approach to design innovative instruments introduced in the Polish surgical robot, Robin Heart, project. Methods: The process of developing the robot starts from the determination of the tools- tissue reaction (mechanical characteristic, the forces for specific operations, dynamic analysis of tools work) and person - a tool and then man-machine contact (kinematic analysis of surgeon motion). Kinematics values of multibody system: surgeon's upper limb - the classic and thoracoscopy tool or master tool manipulator - robot in different configuration (for typical surgery action elements), were determined with the use of APAS system for the trajectory of marker observation, recording and analyzing. On this basis, some typical tasks, functions, tools, and the operator behavior have been listed and a surgical robot control console trying to optimize both the issues of ergonomics, accuracy and work have been designed. Robin Heart Shell console includes not only ergonomic handles with microjoystics but also the advisory system and the possibility of a full visual and voice communication with the operating theater. Results: The ergonomic and high efficiency useful Robin Heart robot system have been constructed and successfully tested in few animal and telerobotic experiments.
DEVELOPMENT OF A BLOOD PRESSURE SIMULATOR Weber, S; Kertzscher, U; Affeld, K
International journal of artificial organs,
08/2011, Volume:
34, Issue:
8
Journal Article
Peer reviewed
Objectives: The blood pressure simulator is needed for the development of a new method to measure blood pressure (BP) noninvasively over 24 hours. It has to provide a pressure curve similar to the ...blood pressure in the radial artery. In addition, it has to provide curves with added artefacts as they result from arm movement. Methods: The blood pressure simulator is driven by a linear motor acting on a piston. The piston is filled with air, which acts as a spring generating a pressure on an enclosed volume. The enclosed volume is filled with the model fluid, which is water containing polystyrene particles. They serve as reflectors for ultrasound waves, since the BP simulator is used for the development of a method using ultrasound to measure blood pressure noninvasively. A water column is connected to the volume generating a hydrostatic pressure p sub(hydro). The model fluid exits the blood pressure simulator and enters a model artery made of thin polyurethane foil embedded in a tissue model made of gelatine. Results: With this simulator any arbitrary pressure curve p(t)= p sub(hydro) +p'(t) can be generated in the artery model. The pressure fluctuation p'(t) is generated by the piston movement x(t) by a linear transfer function p'(t)=k'x(t) with transfer coefficient k. The transfer coefficient depends on the piston area and the spring constant of the air spring. Conclusions: The blood pressure simulator is able to generate complicated pressure curves as they are found in the radial artery of a moving arm. It is such well suited for the development of a new method to measure blood pressure noninvasively.
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