Ravi Vaidyanathan

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This paper presents a novel orientation algorithm designed to support a computationally efficient, wearable inertial human motion tracking system for rehabilitation applications. It is applicable to inertial measurement units (IMUs) consisting of tri-axis gyroscopes and accelerometers, and magnetic angular rate and gravity (MARG) sensor arrays that also(More)
Background—The identification of sites of dominant activation frequency during atrial fibrillation (AF) in humans and the effect of ablation at these sites have not been reported. Methods and Results—Thirty-two patients undergoing AF ablation (19 paroxysmal, 13 permanent) during ongoing arrhythmia were studied. Electroanatomic mapping was performed,(More)
We present a methodology for the design and analysis of power grids in the PowerPC™ microprocessors. The methodology covers the need for power grid analysis across all stages of the design process. A case study showing the application of this methodology to the PowerPC™ 750 microprocessor is presented.
Excessive low-affinity Na(+) uptake is toxic to the growth of glycophytic plants. Recently, several reports have suggested that the interaction between K(+) and Na(+) uptake might represent a key factor in determining the Na(+) tolerance of plants. We investigated the effects of K(+) starvation on Na(+) and K(+) uptake mechanisms in the plasma membrane of(More)
The cardiac electrical impulse depends on an orchestrated interplay of transmembrane ionic currents in myocardial cells. Two critical ionic current mechanisms are the inwardly rectifying potassium current (I(K1)), which is important for maintenance of the cell resting membrane potential, and the sodium current (I(Na)), which provides a rapid depolarizing(More)
The BERT2 social robot, a platform for the exploration of human-robot interaction, is currently being built at the Bristol Robotics Laboratory. This paper describes work on the robot's face, a hybrid face composed of a plastic faceplate and an LCD display, and our implementation of facial expressions on this versatile platform. We report the implementation(More)
This paper discusses service assurance aspects specific to IPTV services and video quality. Classic network monitoring generally assures that each network element, network segment, and sub-network is functioning reliably; and may also encompass routing and reachability across different network domains. IPTV service assurance can encompass much more,(More)
BACKGROUND It is unclear whether atrial fibrillation (AF) drivers in humans are focal or reentrant. To test the hypothesis that functional reentry is involved in human AF maintenance, we determined the effects of adenosine infusion on local dominant frequency (DF) at different atrial sites. By increasing inward rectifier potassium channel conductance,(More)
Heart failure (HF) commonly results in atrial fibrillation (AF) and fibrosis, but how the distribution of fibrosis impacts AF dynamics has not been studied. HF was induced in sheep by ventricular tachypacing (220 bpm, 6 to 7 weeks). Optical mapping (Di-4-ANEPPS, 300 frames/sec) of the posterior left atrial (PLA) endocardium was performed during sustained AF(More)
We report the successful design and fabrication of an autonomous robot, dubbed the CASE/NPS Beach Whegstrade robot, capable of navigating the challenging terrain of the non-submersed surf-zone region based on abstracted biological inspiration. Abstracted biological inspiration attempts to distill salient biological principles and implement them using(More)