| 摘要 |
<p>A method of positioning a catheter, for example a balloon or treatment catheter. The catheter is inserted in a passage and sensed through the luminal wall to correctly determine its position. As applied to prevent hemorrhage during surgery the method involves inserting the catheter in a deflated configuration along a passage such as a blood vessel near to the operative site in a position determined by direct or video-assisted sensing from outside the passage. In the event a blood vessel is cut during surgery, the already-positioned catheter inflates a balloon to occlude the passage and stop blood flow into the injured site. In one aspect, a flow-directed catheter includes an inflatable balloon attached at its distal end and an optical fiber connected to one or more light emitting regions positioned at the tip or in the vicinity of the balloon. The light is divergent and is emitted at one or more points to provide beacons that are readily detected through the walls of a blood vessel and permit a direct determination of the exact location of the balloon within the vessel. Rather than a flow-directed balloon catheter, a drug-delivery or other catheter may be used. In that case the light emitting regions are located at or adjacent to one or more drug delivery ports or other active areas in the catheter. In another or further aspect, one or more magnetic elements are provided on the catheter, and an external magnet is used to feel and engage the catheter through the vessel wall, sense its position, steer and move it along branching vessels, and anchor the balloon in a desired position.</p> |
