A new tonometric test system to assess surface stiffness over relaxed and activated calf muscles was developed. The mechanical arrangement consists of a skin indentor driven by a torque motor (galvo-drive) that is rigidly connected to an ankle dynamometer. The indentation depth is measured by a displacement transducer. Software routines for cyclic indentation (recording of stiffness curves), static indentation (sensing of twitch responses), and vibration (skin resonance) were implemented. A visual interface is used to capture surface stiffness during target contractions and during controlled relaxation. For functional electrical stimulation (FES) applications, the software includes a pulse train synthesizer to generate arbitrary stimulation test patterns. The system's performance was tested in FES and voluntary contraction procedures.
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http://dx.doi.org/10.1046/j.1525-1594.2002.06943.x | DOI Listing |
ACS Nano
January 2025
Department of Electrical Engineering, University at Buffalo, the State University of New York, Buffalo, New York 14260, United States.
Heterogeneous integration of emerging two-dimensional (2D) materials with mature three-dimensional (3D) silicon-based semiconductor technology presents a promising approach for the future development of energy-efficient, function-rich nanoelectronic devices. In this study, we designed a mixed-dimensional junction structure in which a 2D monolayer (e.g.
View Article and Find Full Text PDFAn Acad Bras Cienc
January 2025
University of Technology, Department of Control and System Engineering, Baghdad, 10066, Iraq.
Latency in flux observation has an adverse effect on the performance of observer-based field-oriented speed control for three-phase induction motor (IM). The reduction of the convergent rate of estimation errors could improve the performance of speed-controlled IM based on flux observers. The main contribution is to design a fast convergent flux observer, which provides bounded estimation error immediately after one instant of motor startup.
View Article and Find Full Text PDFPhysiol Rev
January 2025
Department of Physiology and Membrane Biology, University of California, Davis, School of Medicine, Davis CA, 95616, USA.
Biology uses many signaling mechanisms. Among them, calcium and membrane potential are two prominent mediators for cellular signaling. TRPM4 and TRPM5, two calcium-activated monovalent cation-conducting ion channels, offer a direct linkage between these two signals.
View Article and Find Full Text PDFJ Neurophysiol
January 2025
Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Canada.
Anatomical studies have revealed a prominent role for feedback projections in the primate visual cortex. Theoretical models suggest that these projections support important brain functions, like attention, prediction, and learning. However, these models make different predictions about the relationship between feedback connectivity and neuronal stimulus selectivity.
View Article and Find Full Text PDFSci Adv
January 2025
Department of Biophysics, Institute of Quantum Biophysics, Sungkyunkwan University, Suwon 16419, Republic of Korea.
Optical resolution photoacoustic imaging of uneven samples without z-scanning is transformative for the fast analysis and diagnosis of diseases. However, current approaches to elongate the depth of field (DOF) typically imply cumbersome postprocessing procedures, bulky optical element ensembles, or substantial excitation beam side lobes. Metasurface technology allows for the phase modulation of light and the miniaturization of imaging systems to wavelength-size thickness.
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