A semiconductor device of the present invention is a semiconductor device applicable in a cooling system including an ECU functioning as a setting part that sets target temperature of a refrigerant used to cool the semiconductor device, and a sensor functioning as a detector that detects the temperature of the refrigerant as refrigerant’s temperature. In one embodiment, an ultrasound system comprises an ultrasound probe, a sensor unit, a processor unit and an input unit. The hydraulic pump draws low pressure fluid from a sump and delivers high pressure fluid to a series of actuation chambers defined between coaxially aligned first and second components of the rotary operator.