Abstract: A high frequency power supply for applying electrical energy to a target site on or within a patient's body includes an electrical output driver, an output current sensor detecting the current output from the driver, and a power limiting device coupled to the current sensor during normal conditions, the power limiting device operates on a continuous basis. When current output exceeds a predetermined threshold level, the power limiting device is adapted to reduce power on the output driver to a standby mode. The power limiting device operates on a periodic detection or duty cycle when in the standby mode. The power limiting device switches into the stand-by mode to prevent excessive power drains. The power supply operates at a low power, pulsatile manner when an attached probe is in conductive or isotonic fluid but is not engaging body tissue or near a high impedance source. In this pulsatile mode, the power supply operates in a cyclical manner, typically at a predetermined duty cycle.

Abstract: A system for applying high frequency electrical energy to a body structure within a patient where the system detects the presence of conductive fluid. In one embodiment, the system includes a high frequency power supply, a surgical instrument having an electrode terminal, and a conductive fluid sensor coupled to the probe for detecting the presence of conductive fluid near the electrode terminal. The surgical instruments preferably has a shaft with a distal end and a proximal end, an electrode terminal on or near the distal end, and a connector coupling the electrode terminal to the power supply. The conductive fluid sensor may comprise of an electric switch adapted to create an open circuit when in contact with conductive fluid. Alternatively, the conductive fluid sensor may be a resistor that changes resistance when in contact with conductive fluid. The sensor detects for conductive fluid such as body fluid or saline solution. For devices having an active and return electrode (i.e.

Abstract: A high frequency power supply for applying electrical energy to a target site on or within a patient's body includes an electrical output driver, an output current sensor detecting the current output from the driver, and a power limiting device coupled to the current sensor during normal conditions, the power limiting device operates on a continuous basis. When current output exceeds a predetermined threshold level, the power limiting device is adapted to reduce power on the output driver to a standby mode. The power limiting device operates on a periodic detection or duty cycle when in the standby mode. The power limiting device switches into the stand-by mode to prevent excessive power drains. The power supply operates at a low power, pulsatile manner when an attached probe is in conductive or isotonic fluid but is not engaging body tissue or near a high impedance source. In this pulsatile mode, the power supply operates in a cyclical manner, typically at a predetermined duty cycle.