| 摘要 |
Rotating element catheters and catheter assemblies employ clutch assemblies for preventing rotational energy from being transmitted from a motor drive unit to the catheter element under defined circumstances. The catheter assembly includes an elongate member in which there is disposed a rotatable catheter drive cable. The catheter drive cable may have an operative element, e.g., an ultrasonic transducer or an artherectomy blade, distally mounted thereon for providing diagnostic or therapeutic functions to the physician. To control the rotation of the catheter drive shaft, the clutch assembly is configured such that the catheter drive shaft is operated in a drive mode (i.e., it is allowed to rotate) and in a release mode (i.e., it is prevented from rotating). The clutch assembly includes a driver member comprising a first cylindrical body, and a driven member comprising a second cylindrical body in a concentric relationship with the first cylindrical body. The first cylindrical body can be a rigid cylindrical member, and the second cylindrical body can be a compliant tube interference fit about the cylindrical member. Or the first cylindrical body can be a receptacle with cutouts, and the second cylindrical body can be a cylindrical member disposed within the receptacle, with the surface of the cylindrical member being exposed through the cutouts. A spring clamp can then be interference fitted over the receptacle and exposed arcuate surfaces of the cylindrical member. |
