Background—Traditionally, a safety margin of at least 10 J between the maximum output of the pulse generator and the energy needed for ventricular defibrillation has been used because lower safety margins were associated with unacceptably high rates of failed defibrillation and sudden cardiac death. The Low Energy Safety Study (LESS) was a prospective, randomized assessment of the safety margin...

When approached by a potential predator, individuals must decide when to flee. Individuals could assess risk by monitoring their distance from an approaching threat or by monitoring the expected time that the predator would take to reach them. Theory predicts, and empirical studies support the hypothesis, that some species maymaintain a temporal margin of safety and therefore monitor the expect...

Most components undergo tests after they are designed and are redesigned if necessary. Tests help designers find unsafe and overly conservative designs, and redesign can restore safety or increase performance. In general, the expected changes to the performance and reliability of the design after the test and redesign are not considered. In this paper, we explore how modeling a future test and ...

INTRODUCTION In patients undergoing defibrillator implantation, an appropriate defibrillation safety margin has been considered to be either 10 J or an energy equal to the defibrillation energy requirement. However, a previous clinical report suggested that a larger safety margin may be required in patients with a low defibrillation energy requirement. Therefore, the purpose of this prospective...

The chronic defibrillation energy requirement (DER) is believed to remain clinically stable in patients with defibrillators. Six patients (two with an epicardial and four with a nonthoracotomy system) were identified with a rise in their chronic DER, which eliminated a 10-J safety margin, thus necessitating a defibrillator lead system revision. The mean increase in DER was 14.7 +/- 4 J and was ...

A recent model of balance control has revealed two types of boundaries describing stability limits for center of mass (CM) dynamics: torque boundaries and state boundaries. The purpose of this study was to determine if these boundaries correctly characterize empirical data. We analyzed 2367 trials from 10 subjects who recovered their balance after they voluntarily pulled on a handle. We hypothe...

As the air temperature of the Earth rises, ecological relationships within a community might shift, in part due to differences in the thermal physiology of species. Prediction of these shifts - an urgent task for ecologists - will be complicated if thermal tolerance itself can rapidly evolve. Here, we employ a mechanistic approach to predict the potential for rapid evolution of thermal toleranc...