The invention provides a system for treating an occlusion within a body lumen. The system may comprise an insulated outer sheath； an elongated conductive tube, wherein the insulated outer sheath is circumferentially mounted around the elongated conductive tube； and an insulated wire having a helically coiled portion at a distal end of the insulated wire. The coiled portion includes an exposed distal tip, and a distal portion of the elongated conductive tube is circumferentially mounted around the distal coiled portion of the insulated wire. When a voltage is applied across the insulated wire and the elongated conductive tube, a current is configured to flow from the exposed distal tip of the insulated wire to the elongated conductive tube to generate a plurality of cavitation bubbles. In an alternate embodiment, an elongated central electrode is used in place of the conductive tube.
