This paper presents results obtained as part of the DeepStar Phase 10 program on VIV Factors of Safety. The objective was to develop a general methodology to calibrate Factors of Safety for VIV-induced fatigue and to apply it to partially straked risers. This was achieved using reliability methods, accepted industry VIV prediction software and state-of-the-art model test experiments. Most oil c...

Traditionally, speaker authenticationhas focused on two categories of techniques: speaker verification and speaker identification. In this paper, we introduce a third category called verbal information verification (VIV) in which a claimed speaker’s utterances are verified against the key information in the speaker’s registered profile to decide whether the claimed identity should be accepted o...

BACKGROUND Valve-in-valve (VIV) transcatheter aortic valve replacement (TAVR) may be less effective in small surgical valves because of patient/prosthesis mismatch. Bioprosthetic valve fracture (BVF) using a high-pressure balloon can be performed to facilitate VIV TAVR. METHODS AND RESULTS We report data from 20 consecutive clinical cases in which BVF was successfully performed before or afte...

Introduction: After early successful experience with transcatheter aortic valve replacement (TAVR), concept of transcatheter implantation of a new valve within a failing bioprosthetic valve emerged. Valve-in-valve (ViV) implantation seems to be a simpler option for high risk surgical patients. Methods: We performed five ViV procedures in different valve positions. We included patients with fail...

Tunichromes are yellow, polyphenolic tripeptides prevalent in blood cells of tunicates (suborders phlebobranchia and stolidobranchia). Spectrophotometric studies of reactions between tunichrome Mm-1 and VV or VIV ions were conducted in vitro in various media to crudely approximate cellular conditions: deionized water, aqueous methanol, and aqueous buffers at pH 2 and 7. Catechol was used in par...

OBJECTIVES We appraised the incidence and clinical outcomes of patients who were treated with the valve-in-valve (ViV) technique for hemodynamically destabilizing paraprosthetic leak (PPL). BACKGROUND Device malpositioning causing severe PPL after transcatheter aortic valve implantation is not an uncommon finding. It occurs after release of the prosthesis, leading to hemodynamic compromise. I...

PURPOSE In the present report we describe our clinical experience using specific image-based decision making and anatomic considerations for transcatheter valve-in-valve (ViV) implantation in degenerated xenografts with their pericardial leaflets externally mounted around the stent (Mitroflow [SORIN Group, Milan, Italy] or Trifecta [St. Jude Medical, St Paul, MN]). This design seems to increase...

In recent years, the use of transcatheter aortic valve replacement (TAVR) has extended beyond the treatment of native aortic valve stenosis in patients with high surgical risk. TAVR is increasingly being performed for bioprosthetic aortic valve failure, i.e., the valve-in-valve (VIV) procedure. Establishing the success of a VIV procedure can be challenging in these cases. Furthermore, the limit...

Novel “VIV” signal flow graphs are introduced. They provide a description of active filter subblocks consisting of OpAmps with grounded inputs. The Tow-Thomas, the Åckerberg-Mossberg, the Fleischer-Tow, and MFB structures are typical representatives of such a filter class. Many kinds of active filter like the Sallen-Key utilize a more general OpAmp connection with ungrounded inputs. These circu...

A method is described for measuring the local drag coefficient on a long cylinder which exhibits vortex-induced vibration (VIV). Results are shown from a field experiment in which a long flexible pipe was instrumented with two-hundred and eighty fiber optic strain gauges. The measured local drag coefficients are compared to a commonly used drag coefficient prediction formula. The formula is sho...