Acoustic imaging catheter and the like

摘要: Acoustic imaging balloon catheters formed by a disposable liquid-confining sheath supporting high fidelity, flexible drive shaft which carries on its end an ultrasound transducer and includes inflatable dilatation balloon. The rotate with sufficient speed fidelity to produce real time images T.V. screen. In preferred embodiments, special features that contribute the of include particular multi-filar construction concentric, oppositely wound, interfering coils, pre-loaded torque condition coils enhancing their contact, dynamic loading distal probe, preferably viscous drag. coil rotating in presence liquid is used desirable pressure region transducer. Numerous selectable catheter sheaths are shown including integral acoustically-transparent window, extensions aid positioning, injection-producing sheath, having window section under tension employing axially loaded bearing, carrying or positioning over transducer, surgical tool conjunction side-viewing trocar.