Ultrasonic imaging apparatus having circulating cooling liquid for cooling ultrasonic transducers thereof

Claim 1

An endoscopic ultrasonic imaging apparatus comprising: an endoscope including an operation section and an insertion section extending from said operation section, said insertion section having a distal portion at a free end thereof remote from said operation section; transducer means having at least two ultrasonic transducer elements which are rotatably arranged in said distal portion of said endoscope, said transducer elements each having back surfaces which face inward towards each other, said transducer elements each emitting ultrasonic waves and converting echo waves into echo signals; housing means for housing said ultrasonic transducer means, said housing means being filled with ultrasonic transmissive cooling liquid; means defining a circulation path for said ultrasonic transmissive liquid contained in said housing means; means coupled to said circulation path for circulating said ultrasonic transmissive liquid in said circulation path and for cooling said ultrasonic transmissive liquid; rotating means arranged in said operation section of said endoscope and coupled to said transducer means for rotating said transducer means; drive shaft means, rotatably inserted in said insertion section of said endoscope, for coupling said transducer means and said rotating means; transducer drive means for alternately driving said at least two transducer elements during one rotation of said transducer means to alternately emit ultrasonic waves from said at least two transducer elements; said at least two transducer elements receiving echo signals reflected from bio-material during said rotation of said transducer means, and generating output echo signals responsive to received echo signals; switching means for alternately switching said at least two transducer elements during one rotation of said transducer means to switch output echo signals produced by said transducer elements; echo signal output means for outputting, as one echo signal sequence, output echo signals produced by said at least two transducer elements through said switching means; signal processing means for signal-processing said echo signal sequence from said echo signal output means for converting it into a television signal; and display means for displaying the television signal from said signal procesing means as an image.