| 摘要 |
The invention is directed to a radiation delivery catheter assembly having blood perfusion capability suitable for maintaining patency of a body lumen for a period of time sufficient to allow delivery of a radiation source to the body lumen. The catheter assembly includes a spring wire centering mechanism which can be deployed between a retracted and expanded position. In the expanded position, the spring wire centering mechanism contacts a portion of the body lumen and centers a radiation source within the body lumen. In one particular embodiment, movable structural elements (spring wire legs) contact and center the adjacent portion of the catheter body within the body lumen when placed in the expanded position. In the retracted position, the spring wire mechanism is collapsed to a small profile to enable the catheter assembly to reach small diameter body lumens, such as distal coronary arteries. The spring wire centering mechanism is deployed between the retracted and expanded positions utilizing a retractable sheath which extends over the catheter body in a coaxial arrangement. This retractable sheath is movable along the length of the elongated catheter body and is designed to cover the spring wire centering mechanism to maintain it in the retracted position until the mechanism is to be deployed within the body lumen. When the retractable sheath is retracted to expose the spring wire centering mechanism, the resiliency of the spring wire legs moves the mechanism back to the expanded position.
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