A variant factor (VF) technique is developed for the control design of a class of single-input and single-output affine nonlinear systems with input saturation. The main ideas of VF are to convert an affine nonlinear system into a linear time-invariant system similar to the dynamic inversion and then to use the ideas of the composite nonlinear feedback (CNF) technique to design a control law fo...

BACKGROUND The purposes of the present investigation were 1) to track the incidence of primary ventricular fibrillation (VF) in the control and lidocaine-treated groups in the randomized control trials (RCTs) of lidocaine prophylaxis against primary VF in acute myocardial infarction, with particular emphasis on the time frame of the randomized trial, and 2) to estimate the number of patients wh...

Purpose To compare optic nerve head (ONH) measurements in glaucomatous eyes with paracentral visual field (VF) loss to eyes with peripheral VF loss and controls. Methods Open-angle glaucoma (OAG) patients with early paracentral VF loss or isolated peripheral VF loss as well as control subjects underwent ONH imaging with swept-source optical coherence tomography (OCT) and retinal nerve fiber l...

Background—A therapeutic implication of the focal-source hypothesis of ventricular fibrillation (VF) is that VF can be terminated by focal ablation. We hypothesize that -adrenergic receptor blockade converts multiple-wavelet VF to focal-source VF and that this focal source is located near the papillary muscle (PM). Methods and Results—We used optical mapping techniques to study the effects of p...

PURPOSE To examine the detection rates, specificity, and agreement between visual field (VF) progression and Heidelberg Retina Tomograph (HRT; Heidelberg Engineering, GmbH, Heidelberg, Germany) rim area (RA) progression in subjects with ocular hypertension (OHT). METHODS One hundred ninety-eight OHT and 21 control subjects were examined prospectively (1994-2001) with regular Humphrey VF (Carl...

INTRODUCTION Clinically in ventricular fibrillation (VF), ECG amplitude, and frequency decrease as ischemia progresses and predict defibrillation success. In vitro ECG amplitude declines without ischemia, independent of VF frequencies. This study examines the contribution of cellular electrical activity and global organization to ECG amplitude changes during VF. METHODS AND RESULTS Rabbit hea...

Background. The purposes of the present investigation were 1) to track the incidence of primary ventricular fibrillation (VF) in the control and lidocaine-treated groups in the randomized control trials (RCTs) of lidocaine prophylaxis against primary VF in acute myocardial infarction, with particular emphasis on the time frame of the randomized trial, and 2) to estimate the number of patients w...

BACKGROUND A therapeutic implication of the focal-source hypothesis of ventricular fibrillation (VF) is that VF can be terminated by focal ablation. We hypothesize that beta-adrenergic receptor blockade converts multiple-wavelet VF to focal-source VF and that this focal source is located near the papillary muscle (PM). METHODS AND RESULTS We used optical mapping techniques to study the effect...

Placement of an implantable cardioverter-defibrillator (ICD) is the only powerful treatment modality for Brugada syndrome in patients presenting with ventricular fibrillation (VF). For those whose first presentation is an electrical storm, pharmacologic therapy is typically used to control VF followed by ICD implantation. We report an alternative approach whereby, before ICD implantation, emerg...

OBJECTIVES The purpose of this study was to determine if the defibrillation threshold (DFT) is lower during the first few cycles of ventricular fibrillation (VF) than after 10 s of VF and, if so, if the effect is caused by local or global factors. BACKGROUND The DFT may be low very early during VF because: (1) for the first few cycles VF arises from a localized region close to a defibrillatio...