| 摘要 |
<p>Determining the location of a distal end of an insertion tool as it penetrates through biological tissue and into a desired site, such as the lumen of a blood vessel, a joint capsule, or joint space, are described. When the distal tip of an insertion tool traverses the blood vessel wall or penetrates a joint capsule, the reflecting plane of the vessel wall or joint capsule is positioned at or near zero distance relative to the distal tip of the light guide. Once the distal tip enters a less dense blood vessel lumen or joint space, the distance to the reflecting plane becomes greater than zero, thus producing a change or drop in the intensity of the reflected light that is measured by a light sensor and interpreted by a logic unit providing an indication to the operator that the desired site has been reached.</p> |
