Ultrasonic sector scanner

摘要

An ultrasonic sector scanner includes first and second magnetizable stators spaced on a longitudinal axis. First and second rotors are provided in the gaps between the end faces of the first and second stators, respectively. The rotors have tapered surfaces spaced from the end faces of the stators to form gaps therebetween. The gaps between the first rotor and the end face of the first stator decrease as the rotor rotates in a first direction. The gaps between the second rotor and the end faces of the second stator decrease as the rotors rotate in a second direction opposite the first direction. An ultrasonic transducer is connected to the rotors and arranged to be rotatable with the rotors. A servo-control system is provided to cause the rotor/transducer assembly to rotate according to a prescribed reference signal. The ultrasonic sector scanner has a cover assembly in which a flexible membrane is provided with ribs which engage grooves in the wall of the housing. A heat-shrink tube or other retaining ring is arranged around the flexible membrane in order to press the ribs into the grooves. The ultraonic sector scanner includes a rigid nose piece inside and spaced from the flexible membrane in order to increase the skin contact area when the flexible membrane of the sector scanner is pressed against the skin of a patient being examined.