| 摘要 |
Acoustic imaging balloon catheters (6) formed by a disposable liquid-confining sheath (12) supporting a high fidelity, flexible drive shaft (18) which carries on its end an ultrasound transducer (10) and includes an inflatable dilatation balloon (55). The shaft and transducer rotate with sufficient speed and fidelity to produce real time images on a T.V. screen (23). In preferred embodiments, special features that contribute to the high fidelity of the drive shaft include the particular multifilar construction of concentric, oppositely wound, interfering coils (26, 28), a preloaded torque condition on the coils enhancing their interfering contact, and dynamic loading of the distal end of the probe, preferably with viscous drag. The coil rotating in the presence of liquid in the sheath is used to produce a desirable pressure in the region of the transducer. Numerous selectable catheter sheaths include end adaptations for positioning (80, 86), liquid injection (197), tensioned rotation (101), surgical usage (105), and use with a trocar (98). |
