This dissertation discusses the theory of single-amplifier biquadratic filters (SABs) and their implementation as CMOS video-frequency filters. It shows that building filters as cascades of single-amplifier biquadratic MOSFET–C sections is a viable alternative to using biquadratic Gm–C filter sections. The advantage of MOSFET–C SABs is that they typically use less chip area than a Gm–C filter w...

The velocity function (VF) of galaxies is analogous to the luminosity function (LF), but a more direct tool for comparing observations and theory. The 2MASS LF is calculated here for a local sample of 4000 galaxies, and the VF is derived from a 1000 galaxy subsample drawn from it. The observed VF follows a Schechter functional form. All current analytical, semi-analytical, and numerical galaxy ...

any experimental and clinical studies on the mechanisms of ventricular fibrillation (VF) have been performed over the past 10 decades. The underlying mechanisms of VF have been discussed from different points of view: initiation and maintenance. It is beyond question that reentry, triggered activity or automaticity initiates VF, but the mechanism of its maintenance is not fully determined. Alth...

Ventricular fibrillation (VF) is known as a main responsible cause of sudden cardiac death which claims thousands of lives each year. Although the mechanism of VF induction has been investigated for over a century, its definite mechanism is still unclear. In the past few decades, the development of new advance technologies has helped investigators to understand how the strong stimulus or the sh...

BACKGROUND Prior investigation of out-of-hospital cardiac arrest has raised the concern that ventricular fibrillation (VF) recurrence may be triggered by chest compression (CC) resumption. We investigated predictors of VF recurrence after defibrillation, including timing of CC resumption. METHODS AND RESULTS Patients with witnessed out-of-hospital cardiac arrest and initial rhythm of VF from ...

BACKGROUND Premature stimuli can cause ventricular fibrillation (VF) during electrophysiological testing. The electrophysiological correlations associated with the onset of VF were evaluated in 40 patients who had this rhythm induced during programmed ventricular stimulation. These parameters were compared with those observed in 51 patients who had inducible sustained monomorphic ventricular ta...

BACKGROUND The Purkinje fiber system has recently been implicated as an important driver of the rapid activation rate during long duration ventricular fibrillation (VF>2 minutes). The goal of this study is to determine whether this activity propagates to or occurs in the proximal specialized conduction system during VF as well. METHODS AND RESULTS An 8×8 array with 300 µm spaced electrodes wa...

OBJECTIVES This study was designed to analyze the incidence of "dual tachycardia"-ventricular tachycardia (VT) or ventricular fibrillation (VF) preceded by paroxysmal atrial tachycardia (AT) or atrial fibrillation (AF)-in patients receiving dual-chamber implantable cardioverter defibrillators (ICDs). BACKGROUND Paroxysmal AT/AF occurs commonly in patients who receive ICDs for the treatment of...

OBJECTIVES This study aimed to determine whether increased QT interval variability is associated with an increased risk for ventricular tachycardia (VT) or ventricular fibrillation (VF), documented by interrogation of the implantable cardioverter-defibrillator (ICD), in patients enrolled in the Multicenter Automatic Defibrillator Implantation Trial (MADIT) II. BACKGROUND Unstable repolarizati...