| 摘要 |
A selectively controllable inflation-deflation device (10) for use with a balloon catheter during angioplasty procedures is disclosed. The device is constructed so that the piston shaft can be 1) locked and then rotatably and incrementally moved within the syringe cylinder to enable controlled pressurization, or 2) unlocked and moved within the cylinder to enable fluid purging of the cylinder and retraction of the piston shaft to a vacuum position. The device has a cylinder (12) with proximal (14) and distal (16) ends and a fluid conduit (18) adapted for communication with a balloon. A piston shaft (24) is received within the proximal end of the cylinder. The piston shaft includes a piston (26) mounted on the distal end of the shaft and the shaft is movable in one direction during inflation and in a second direction during deflation of the balloon. Screw threads are positioned on at least a portion of the piston shaft. A cam mechanism in the preferred form of a flexible arm (32) and half nut member (44) is mounted within the cylinder. A cam actuation mechanism in the preferred form of a collar (46) is rotatably mounted on the cylinder and includes an extension (52) that contacts a cam surface (40) on the flexible arm and compresses the support arm to engage and disengage the half nut member with the threaded piston shaft. <IMAGE> |
