Abstract: A phased radiofrequency ablation catheter includes at least three radiofrequency electrodes arrayed on the catheter shaft. Each electrode is configured to emit radiofrequency energy. The energy emitted by more centrally-located electrodes within the array is phase-delayed relative to the energy emitted by more peripherally-located electrodes within the array. Thus, the radiofrequency energy emitted by the electrodes sums to a therapeutic maximum at a preset therapeutic distance from the catheter shaft, which in turn corresponds to a desired lesion depth in the tissue being ablated. The phrase-delay can be achieved through the use of electronic delay lines, including capacitors and/or coils. In embodiments of the disclosure, the capacitor is integrally formed with one or more of the electrodes, such as by interposing one or more dielectric layers between conductive layers of the electrode.

Abstract: A fluid injection system for an internal combustion engine such as a spark-ignition engine in which an injection nozzle injects a finely divided spray of fluid, such as water or a water solution, into the engine in response to a flow of atomizing air. The nozzle is connected to a fluid supply reservoir and to the outlet line of an air compressor for supplying air to the nozzle to induce the flow of fluid through the nozzle. A pressure responsive flow control device is provided that is responsive to engine load, as manifested by the pressure in the intake manifold, for controlling the flow of air to the nozzle, and therefore the discharge of fluid from the nozzle. As a result, the flow of atomizing air to the nozzle, and therefore the rate of fluid injection, is varied in response to variations in engine load.