Ultrasonic endoscope

Claim 1

An ultrasonic endoscope comprising: an operation section; an insertion section having a longitudinal axis and extending from the operation section, said insertion section being adapted to be inserted into a body cavity; a driving member mounted in a distal end portion of the insertion section to be rotatable with respect to said insertion section around an axis parallel to the longitudinal axis of the insertion section, said insertion section being closed by a distal end wall located adjacent to said driving member so that said driving member can be enclosed in said insertion section; drive means for rotating the driving member; and an ultrasonic scanning unit attached to the distal end of the insertion section, said unit including a casing having an ultrasonic radiation window and a scanning chamber filled with a liquid ultrasonic transmission medium, said scanning chamber including a scanning chamber wall adapted to be located adjacent to said insertion section end wall, an ultrasonic generator disposed in the scanning chamber and generating ultrasonic waves, and a rotary scanning means for radiating the ultrasonic waves generated by the generator through the window and repeatedly deflecting the waves by a predetermined angle, said scanning means including a driven member enclosed within said scanning chamber and mounted to be rotatable with respect to said casing, said driven member being fluidically isolated from said driving member by said scanning chamber wall and said insertion section distal end wall and being coupled to said driving member by a magnetic coupling, said driven member being disposed in the scanning chamber to be opposite to said driving member so as to be rotatable around the same axis as the driving member while being rotatable with respect thereto, the magnetic coupling between said driven member and said driving member causing said driven member to rotate as the driving member rotates; and connecting means for detachably connecting said scanning unit to said insertion section with said insertion section end wall in abutting contact with said scanning chamber wall, whereby said scanning chamber and said insertion section are fluidically isolated from each other when said scanning unit is attached to said insertion section and said scanning chamber can remain fluidically closed when said scanning unit is detached from said insertion section.