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BACKGROUND Conventional programmed ventricular stimulation protocols are inefficient compared with more recently proposed protocols. The purpose of the present study was to determine if additional efficiency could be derived from a 6-step programmed ventricular stimulation protocol that exclusively uses four extrastimuli. METHODS AND RESULTS The subjects(More)
This paper proposes a new framework for spectrum reuse. Existing architectures have centered on secondary users (cognitive radios) that can reliably sense primary users and opportunistically transmit, without directly interacting with the primary system. We present a paradigm in which the primary and secondary systems cooperate, to minimize interference to(More)
Cognitive Radios require sensing to detect the presence of Primary Users in a frequency band. Sensing is hampered by shadowing, multi-path and penetration loss through buildings. Hence an individual radio must be designed to be highly sensitive to overcome these signal variations. In this paper we investigate cooperative sensing, where Cognitive Radios use(More)
OBJECTIVES The use of fluoroscopy for indirect guidance in orthopaedic trauma surgery has increased. The purpose of this investigation was to assess how real-time visualization of radiation exposure impacts dose levels during orthopaedic trauma operations. DESIGN Observational comparative study. SETTING Level 1 trauma center orthopaedic trauma surgery(More)
OBJECTIVES The purpose of this study was to determine whether the polarity of a monophasic shock used with a transvenous lead system affects the defibrillation threshold. BACKGROUND The ability to implant an automatic defibrillator depends on achieving an adequate defibrillation threshold. METHODS A transvenous defibrillation lead with distal and(More)
This paper presents a practical method for using multi-antenna radios to cancel interference in cognitive radio systems. Under this method, secondary radio transmitters use beamforming techniques to find antenna weights that place nulls at the primary receivers, and secondary radio receivers use adaptive techniques to decode in the presence of interference(More)
Although mobile phone usage has proliferated in urban areas of developing countries, many rural or poor users remain completely unconnected, particularly in Africa. In this paper, we advocate an alternative “voice message mostly” mobile phone architecture to reach the next billion users. Using initial analyses of mobile phone usage and rural power data, we(More)
No prospective studies have compared sotalol and amiodarone during electropharmacologic testing. The purpose of this prospective, randomized study was to compare the electrophysiologic effects of sotalol and amiodarone in patients with coronary artery disease and sustained monomorphic ventricular tachycardia (VT). Patients with coronary artery disease and(More)