A system and method are provided for detecting connection status of a universal serial bus port of a mobile phone and a terminal device from among connecting, connected, disconnecting, or disconnected status. The pump further includes a plurality of shorted coils coupled to the other of the stator and the impeller. A desired ablation depth is also achieved by controlling the energy density or power density, and the amount of time required for energy delivery. A central tether may be provided during an installation phase only, until the risers are in place and hold the buoy by their own tension.