Abstract: Flexible catheters adapted to be inserted into a body to deliver high-voltage, fast (e.g., microsecond, sub-microsecond, nanosecond, picosecond, etc.) electrical energy to target tissue may include a plurality of conductive layers, that may be coaxial. These catheters and method of using them to treat tissue are configured to reduce or avoid arcing.

Abstract: Flexible catheters adapted to be inserted into a body to deliver high-voltage, fast (e.g., microsecond, sub-microsecond, nanosecond, picosecond, etc.) electrical energy to target tissue may include a plurality of conductive layers, that may be coaxial. These catheters and method of using them to treat tissue are configured to reduce or avoid arcing.

Abstract: A variable flow sprinkler head having an inlet, an outlet and a nozzle, the nozzle having an orifice therein, the cross sectional area of the orifice being changeable by alternately inserting or removing a needle into the sprinkler head nozzle orifice. The needle diameter is sized to provide a predetermined flow rate reduction when the needle is inserted into the nozzle orifice. When the needle is removed full flow occurs. When the needle is inserted into the center of the nozzle orifice, the cross sectional area is effectively reduced by an amount equal to the cross sectional area of the needle. A linear actuator for the needle is centered above the outlet. The linear actuator may be either an electric solenoid or a hydraulic actuator. Alternatively, the linear actuator may provide a mechanism to allow the sprinkler to be operated between either of two preselected flow rates or in the alternative to be shut off completely.