Abstract: Systems and methods for delivering a drug with a tracer or contrast agent are disclosed herein, as are systems and methods that generally involve CED devices with various features for reducing or preventing backflow. In some embodiments, CED devices include a tissue-receiving space disposed proximal to a distal fluid outlet. Tissue can be compressed into or pinched/pinned by the tissue-receiving space as the device is inserted into a target region of a patient, thereby forming a seal that reduces or prevents proximal backflow of fluid ejected from the outlet beyond the tissue-receiving space. In some embodiments, CED devices include a bullet-shaped nose proximal to a distal fluid outlet. The bullet-shaped nose forms a good seal with surrounding tissue and helps reduce or prevent backflow of infused fluid.

Abstract: Systems and methods for delivering a drug with a tracer or contrast agent are disclosed herein, as are systems and methods that generally involve CED devices with various features for reducing or preventing backflow. In some embodiments, CED devices include a tissue-receiving space disposed proximal to a distal fluid outlet. Tissue can be compressed into or pinched/pinned by the tissue-receiving space as the device is inserted into a target region of a patient, thereby forming a seal that reduces or prevents proximal backflow of fluid ejected from the outlet beyond the tissue-receiving space. In some embodiments, CED devices include a bullet-shaped nose proximal to a distal fluid outlet. The bullet-shaped nose forms a good seal with surrounding tissue and helps reduce or prevent backflow of infused fluid.

Abstract: Systems and methods for delivering a drug with a tracer or contrast agent are disclosed herein, as are systems and methods that generally involve CED devices with various features for reducing or preventing backflow. In some embodiments, CED devices include a tissue-receiving space disposed proximal to a distal fluid outlet. Tissue can be compressed into or pinched/pinned by the tissue-receiving space as the device is inserted into a target region of a patient, thereby forming a seal that reduces or prevents proximal backflow of fluid ejected from the outlet beyond the tissue-receiving space. In some embodiments, CED devices include a bullet-shaped nose proximal to a distal fluid outlet. The bullet-shaped nose forms a good seal with surrounding tissue and helps reduce or prevent backflow of infused fluid.

Abstract: A method of modeling and rendering a three-dimensional complex surface using a triangle mesh is disclosed. The method can reduce memory requirement and rendering time by using local height maps and by assigning neighborhood coordinates to any point on a surface near the triangle mesh assigned to that surface. Barycentric coordinates are used to identify points in a triangular polygon to work with height data in the local height map associated with that triangular polygon. The local height maps allow collision detection of a ray with the three-dimensional surface. Lipshitz constants associated with the three-dimensional surfaces are used to find a point on the next ray closest to the three-dimensional surface to jump to, making the search for such collision points efficient.