13,812 research outputs found
Rehabilitation robot cell for multimodal standing-up motion augmentation
The paper presents a robot cell for multimodal standing-up motion augmentation. The robot cell is aimed at augmenting the standing-up capabilities of impaired or paraplegic subjects. The setup incorporates the rehabilitation robot device, functional electrical stimulation system, measurement instrumentation and cognitive feedback system. For controlling the standing-up process a novel approach was developed integrating the voluntary activity of a person in the control scheme of the rehabilitation robot. The simulation results demonstrate the possibility of āpatient-drivenā robot-assisted standing-up training. Moreover, to extend the system capabilities, the audio cognitive feedback is aimed to guide the subject throughout rising. For the feedback generation a granular synthesis method is utilized displaying high-dimensional, dynamic data. The principle of operation and example sonification in standing-up are presented. In this manner, by integrating the cognitive feedback and āpatient-drivenā actuation systems, an effective motion augmentation system is proposed in which the motion coordination is under the voluntary control of the user
Three-Dimensional Numerical Modeling of Acoustic Trapping in Glass Capillaries
Acoustic traps are used to capture and handle suspended microparticles and
cells in microfluidic applications. A particular simple and much-used acoustic
trap consists of a commercially available, millimeter-sized, liquid-filled
glass capillary actuated by a piezoelectric transducer. Here, we present a
three-dimensional numerical model of the acoustic pressure field in the liquid
coupled to the displacement field of the glass wall, taking into account mixed
standing and traveling waves as well as absorption. The model predicts
resonance modes well suited for acoustic trapping, their frequencies and
quality factors, the magnitude of the acoustic radiation force on a single test
particle as a function of position, and the resulting acoustic retention force
of the trap. We show that the model predictions are in agreement with published
experimental results, and we discuss how improved and more stable acoustic
trapping modes might be obtained using the model as a design tool.Comment: 13 pages, 15 pdf figures, pdfLatex/Revte
Planar microfluidics - liquid handling without walls
The miniaturization and integration of electronic circuitry has not only made
the enormous increase in performance of semiconductor devices possible but also
spawned a myriad of new products and applications ranging from a cellular phone
to a personal computer. Similarly, the miniaturization and integration of
chemical and biological processes will revolutionize life sciences. Drug design
and diagnostics in the genomic era require reliable and cost effective high
throughput technologies which can be integrated and allow for a massive
parallelization. Microfluidics is the core technology to realize such
miniaturized laboratories with feature sizes on a submillimeter scale. Here, we
report on a novel microfluidic technology meeting the basic requirements for a
microfluidic processor analogous to those of its electronic counterpart: Cost
effective production, modular design, high speed, scalability and
programmability
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