Catheter Obstruction: A hindrance to the passage of fluids through a CATHETER.Catheters, Indwelling: Catheters designed to be left within an organ or passage for an extended period of time.Equipment Failure: Failure of equipment to perform to standard. The failure may be due to defects or improper use.Catheters: A flexible, tubular device that is used to carry fluids into or from a blood vessel, hollow organ, or body cavity.Intestinal Obstruction: Any impairment, arrest, or reversal of the normal flow of INTESTINAL CONTENTS toward the ANAL CANAL.Airway Obstruction: Any hindrance to the passage of air into and out of the lungs.Ureteral Obstruction: Blockage in any part of the URETER causing obstruction of urine flow from the kidney to the URINARY BLADDER. The obstruction may be congenital, acquired, unilateral, bilateral, complete, partial, acute, or chronic. Depending on the degree and duration of the obstruction, clinical features vary greatly such as HYDRONEPHROSIS and obstructive nephropathy.Catheterization: Use or insertion of a tubular device into a duct, blood vessel, hollow organ, or body cavity for injecting or withdrawing fluids for diagnostic or therapeutic purposes. It differs from INTUBATION in that the tube here is used to restore or maintain patency in obstructions.Catheterization, Central Venous: Placement of an intravenous CATHETER in the subclavian, jugular, or other central vein.Duodenal Obstruction: Hindrance of the passage of luminal contents in the DUODENUM. Duodenal obstruction can be partial or complete, and caused by intrinsic or extrinsic factors. Simple obstruction is associated with diminished or stopped flow of luminal contents. Strangulating obstruction is associated with impaired blood flow to the duodenum in addition to obstructed flow of luminal contents.Urethral Obstruction: Partial or complete blockage in any part of the URETHRA that can lead to difficulty or inability to empty the URINARY BLADDER. It is characterized by an enlarged, often damaged, bladder with frequent urges to void.Urinary Bladder Neck Obstruction: Blocked urine flow through the bladder neck, the narrow internal urethral opening at the base of the URINARY BLADDER. Narrowing or strictures of the URETHRA can be congenital or acquired. It is often observed in males with enlarged PROSTATE glands.Nasal Obstruction: Any hindrance to the passage of air into and out of the nose. The obstruction may be unilateral or bilateral, and may involve any part of the NASAL CAVITY.Gastric Outlet Obstruction: The hindering of output from the STOMACH into the SMALL INTESTINE. This obstruction may be of mechanical or functional origin such as EDEMA from PEPTIC ULCER; NEOPLASMS; FOREIGN BODIES; or AGING.Ventricular Outflow Obstruction: Occlusion of the outflow tract in either the LEFT VENTRICLE or the RIGHT VENTRICLE of the heart. This may result from CONGENITAL HEART DEFECTS, predisposing heart diseases, complications of surgery, or HEART NEOPLASMS.Central Venous Catheters: Catheters that are inserted into a large central vein such as a SUBCLAVIAN VEIN or FEMORAL VEIN.Urinary Catheterization: Passage of a CATHETER into the URINARY BLADDER or kidney.Catheterization, Peripheral: Insertion of a catheter into a peripheral artery, vein, or airway for diagnostic or therapeutic purposes.Cardiac Catheters: Catheters inserted into various locations within the heart for diagnostic or therapeutic purposes.Lacrimal Duct Obstruction: Interference with the secretion of tears by the lacrimal glands. Obstruction of the LACRIMAL SAC or NASOLACRIMAL DUCT causing acute or chronic inflammation of the lacrimal sac (DACRYOCYSTITIS). It is caused also in infants by failure of the nasolacrimal duct to open into the inferior meatus and occurs about the third week of life. In adults occlusion may occur spontaneously or after injury or nasal disease. (Newell, Ophthalmology: Principles and Concepts, 7th ed, p250)Urinary Catheters: Catheters inserted into the URINARY BLADDER or kidney for therapeutic or diagnostic purposes.Catheter-Related Infections: Infections resulting from the use of catheters. Proper aseptic technique, site of catheter placement, material composition, and virulence of the organism are all factors that can influence possible infection.Equipment Design: Methods of creating machines and devices.