| 摘要 |
A device for removing obstructions from vessels or small openings in the body, comprising a rotatable ablator tip which is guided to the obstruction in a reduced diameter configuration, expanded and rotated to remove the obstruction, and contracted to remove the device from the body. The variably expandable abrasive tip coil in one embodiment of the invention is actuated by a piston means disposed within the coil. A pair of collars is attached to the ends of the coil, and the piston effects relative longitudinal axial movement of the collars and, hence, the respective ends of the coil tip. When the ends of the coil tip are so moved with respect to one another, expansion and contraction of the diameter of the coil tip results. In another embodiment of the invention, the expansion tip coil is actuated by an expandable and contractible bellows means disposed within the coil, instead of the piston means. In another embodiment of the invention, the expansion and contraction of the coil tip are effected by longitudinal axial movement of an internal coil attached to one end of the coil tip, within an outer coil attached to the other end of the coil tip. In another embodiment of the invention, expansion and contraction of the coil tip are effected by an inflatable balloon disposed within the coil tip. The balloon expansion means enlarges preferably at the central portion of the coil to make a bulge.
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