An electric wheelchair comprising a movable seat part, a body part served as a support for the seat part, a seat adjustment mechanism arranged under the seat part, a bottom part, and a crawler moving mechanism. The nozzle has an elongated body. Each data frame includes indication of the ultrasound imaging mode and includes ultrasound-imaging-mode-specific imaging parameters. The second and third power supply lines are arranged, in use, to provide separate connections between the respective fans and a power source other than the first power source. A power supply switching unit, electrically coupled to DC power source and the AC power input, selectively electrically couples the motor with one of the DC power source and the AC power input for providing power to the motor. The lens care composition comprises at least one surfactant, a polyvinylpyrrolidone, xylitol, a buffering agent, wherein in combination with polyvinylpyrrolidone and xylitol, the surfactant provides the persistent lipid removal efficacy.