Fluidic soft sensors have been widely used in wearable devices for human motion capturing. However, thus far, the biocompatibility of the conductive liquid, the linearity of the sensing signal, and ...the hysteresis between the loading and release processes have limited the sensing quality as well as the applications of these sensors. In this paper, silicone based strain and force sensors composed of a novel biocompatible conductive liquid (potassium iodide and glycerol solution) are introduced. The strain sensors exhibit negligible hysteresis up to 5 Hz, with a gauge factor of 2.2 at 1 Hz. The force sensors feature a novel multifunctional layered structure, with microcylinder‐filled channels to achieve high linearity, low hysteresis (5.3% hysteresis at 1 Hz), and good sensitivity (100% resistance increase at a 5 N load). The sensors' gauge factors are stable at various temperatures and humidity levels. These biocompatible, low hysteresis, and high linearity sensors are promising for safe and reliable diagnostic devices, wearable motion capture, and compliant human–computer interfaces.
A new biocompatible electrolyte solution for wearable devices is introduced. This solution is not only safe to the human body, but also has higher conductivity and lower viscosity compared to previously used biocompatible liquids. Fluidic strain and force sensors developed with this new solution have high sensitivities and low hysteresis, are highly linear, and have bandwidths appropriate for human motion detection.
We describe the design and control of a wearable robotic device powered by pneumatic artificial muscle actuators for use in ankle-foot rehabilitation. The design is inspired by the biological ...musculoskeletal system of the human foot and lower leg, mimicking the morphology and the functionality of the biological muscle-tendon-ligament structure. A key feature of the device is its soft structure that provides active assistance without restricting natural degrees of freedom at the ankle joint. Four pneumatic artificial muscles assist dorsiflexion and plantarflexion as well as inversion and eversion. The prototype is also equipped with various embedded sensors for gait pattern analysis. For the subject tested, the prototype is capable of generating an ankle range of motion of 27° (14° dorsiflexion and 13° plantarflexion). The controllability of the system is experimentally demonstrated using a linear time-invariant (LTI) controller. The controller is found using an identified LTI model of the system, resulting from the interaction of the soft orthotic device with a human leg, and model-based classical control design techniques. The suitability of the proposed control strategy is demonstrated with several angle-reference following experiments.
Eugene Goldfield lays out principles of engineering found in the natural world, with a focus on how components of coordinated structures organize themselves into autonomous functional systems. This ...self-organizing capacity is one of many qualities which can be harnessed to design technologies that can interact seamlessly with human bodies.
The requirements of evidence-based practice in 2017 are motivating new theoretical foundations and methodological tools for characterizing neonatal feeding behavior. Toward that end, this article ...offers a complex dynamical systems perspective. A set of critical concepts from this perspective frames challenges faced by speech-language pathologists and allied professionals: when to initiate oral feeds, how to determine the robustness of neonatal breathing during feeding and appropriate levels of respiratory support, what instrumental assessments of swallow function to use with preterm neonates, and whether or not to introduce thickened liquids. In the near future, we can expect vast amounts of new data to guide evidence-based practice. But unless practitioners are able to frame these issues in a systems context larger than the individual child, the availability of "big data" will not be effectively translated to clinical practice.
This study provides a detailed description of the process of the emergence of the utensil-using skill of infants to control encounters with food and mother-infant joint action that surrounds the ...emergence of this context-specific skill. Longitudinal observations from the first contact with a utensil to the beginning of successful self-feeding with a utensil found that there was an extended period of exploratory utensil use that precedes the use of the utensil for the goal of feeding around which adults organized the environment where such feeding-irrelevant activities of the infants were tolerated. Subsequently, adults gradually introduced and highlighted the opportunities for infants' functional feeding encounters, often by adjusting the position of objects on the table. Overall, we found the process of what may be called affordance selection-in which a definite set of opportunities for action among many available were selected by adults to invite certain spontaneous behaviors of developing infants. This study adds to the growing realization that normally occurring experiences of rich affordances matter in the development of specific behavior in a given cultural context.
Tongue–soft palate coordination and bolus head pharyngeal transit were studied by means of postacquisition kinematic analysis of videofluoroscopic swallowing images of ten preterm infants referred ...from hospital NICUs due to poor oral feeding and suspicion of aspiration. Sequences of coordinated tongue–soft palate movements and bolus transits during swallows of thin-consistency and nectar-thick-consistency barium were digitized, and time series data were used to calculate continuous relative phase, a measure of coordination. During swallows of nectar-thick compared to thin barium, tongue–soft palate coordination was more likely to be antiphase, bolus head pharyngeal transit time was longer, and coordination was significantly correlated with bolus head pharyngeal transit. Analysis of successive swallows indicated that tongue–soft palate coordination variability decreased with nectar-thick but not with thin-consistency barium. Together, the results suggest that slower-moving bolus transits may promote greater opportunity for available sensory information to be used to modulate timing of tongue–soft palate movements so that they are more effective for pumping liquids.
Highlights • Functional differentiation of limbs occurs when children perform multiple tasks. • Children keep the body stable when walking and carrying objects at the same time. • Transitions between ...stance and swing affect inter-limb coordination of the shoulders and hips. • Whole-body coordination may be partitioned as a function of task requirements.
In article number 1807058, Robert J. Wood and co‐workers describe a silicone‐based strain and force sensor composed of a novel biocompatible conductive liquid (potassium iodide and glycerol ...solution). This solution is not only safe to the human body, but also has higher conductivity and lower viscosity compared to previously used biocompatible liquids.
This prospective study compared the coordination of sucking, swallowing, and breathing and its relationship to oxygen saturation in infants during breast-feeding and bottle-feeding. After 4 to 6 wk ...of exclusive breast-feeding, infants began bottle-feedings of expressed human milk using one of two systems: a soft-walled bottle and nipple (system 1, Playtex) or a hard-walled bottle and nipple (system 2, Avent). Infants' sucking, swallowing, breathing, and oxygenation were measured during breast-feeding and bottle-feeding, and coordination of these activities during breast-feeding and bottle-feeding were compared. During breast-feeding, swallowing occurred nonrandomly between breaths and did not interfere with breathing. The same distribution of swallowing occurred in infants fed with system 1, while swallowing occurred randomly in infants fed with system 2. Swallowing significantly increased during bottle-feeding among infants using system 2, but decreased among infants using system 1. Infants using system 2 also had a greater instability in the coordination of sucking, swallowing, and breathing and more perturbation of breathing. Oxygen saturation was significantly higher in infants fed with system 1 compared with system 2. These results suggest that the overall feeding pattern and oxygenation of system 1 are closer to the physiologic norm than system 2.
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