Abstract: A catheter for ablating tissue is disclosed that has a self-centering multiray electrode assembly. The self-centering multiray electrode assembly may have a plurality of spines, each of which a preshaped, expanded configuration that curves to change an orientation of the spine from being directed towards the distal end of catheter body to being directed towards the proximal end of the catheter body. The ablation electrodes engage ostial tissue when a maximal outer diameter of the self-centering multiray electrode assembly is engaged with an inner diameter of a vessel. The compliance of each spine may vary along its length. When the self-centering multiray electrode assembly is engaged within a vessel, the ablation electrodes are brought into contact with tissue and may be used to form lesions in a circumferential path around the vessel.

Abstract: A catheter for ablating tissue is disclosed that has a self-centering multiray electrode assembly. The self-centering multiray electrode assembly may have a plurality of spines, each of which a preshaped, expanded configuration that curves to change an orientation of the spine from being directed towards the distal end of catheter body to being directed towards the proximal end of the catheter body. The ablation electrodes engage ostial tissue when a maximal outer diameter of the self-centering multiray electrode assembly is engaged with an inner diameter of a vessel. The compliance of each spine may vary along its length. When the self-centering multiray electrode assembly is engaged within a vessel, the ablation electrodes are brought into contact with tissue and may be used to form lesions in a circumferential path around the vessel.

Abstract: An opposed piston engine (10) comprising upper (12) and lower (14) cylinders and opposed pairs of pistons (16, 18) slidable therein and interconnected by rocker pivots (24, 26). A crankshaft (56) coupled to the rocker pivots (24, 26) constrains the movement of the pistons (16, 18) and is disposed with the crankshaft axis (58) intersecting the axis (44) of one of the cylinders (12, 14), whereby the geometry of the engine (10) is significantly changed thereby reducing torsional vibration and enabling a two stroke diesel version of the engine to be used as a power source for an aircraft propeller.

Abstract: An elevator door monitoring system determines if any hatch door at any floor along an elevator shaft or any other door leading to the shaft is opened while an elevator cab is away from the door. The system includes a plurality of non-contact hatch door monitors, such as infrared proximity detectors. At least one monitor is positioned on the elevator shaft at a respective location generally opposite each hatch door along the shaft. Each monitor detects the opening of the respective hatch door without direct contact therewith, e.g., by directing radiation toward the door and measuring the distance to the door. If the distance is too great, indicating that the door is open and no elevator is present, the monitor produces an alarm signal. The alarm signal is sent to a control circuit which takes the elevator out of service and operates audible and visual alarms in response thereto.