A scooter includes a body having four pulleys at four corners of the body. In the film, a light-scattering characteristic F represents a relationship between the light-scattering angle \u03b8 and a scattered light intensity F fulfills FyFx\u22671. A head select boost recovery circuit is also operatively coupled to the bias voltage circuit and is configured to increase a rate of charging or discharging of a bias capacitor associated with the bias voltage circuit stage. The controller is employed to provide the scan control signal and the data control signal. The device may be used to treat ascites, chronic pericardial effusions, normopressure hydrocephalus, hydrocephalus, pulmonary edema, or any fluid collection within the body of a human, or a non-human mammal.