This paper presents the design of a robust controller using the Quantitative Feedback Theory technique for an asymmetric hydraulic cylinder electro-hydraulic servo system based upon a linear, parametrically uncertain model in which some of the uncertainties reflect the variation of the parameters, and taking the external disturbance into account. After the derivation of a realistic nonlinear di...

OBJECTIVE To determine the efficacy of peroral electrohydraulic lithotripsy performed with an extra large duodenoscope (outside diameter 14.8 mm) and a choledochoscope with a diameter of 4.1 mm (Olympus "mother and baby" endoscope system) in the removal of very large stones from the common bile duct. DESIGN Prospective study of patients with giant stones in the common bile duct that were resi...