Rapid Path Extraction and Three-Dimensional Roaming of the Virtual Endonasal Endoscope

Compared with traditional endonasal endoscope, Virtual endonasal endoscope (VEE) is a computerized alternative solution with the advantages of being non-invasive, affordable, no perforation, low risk of infection, and high degree of sensitivity. A Central path extraction algorithm based on Pre-planning of the roaming area (CPE-PRA) is proposed to extract the central path of the nasal cavity model efficiently. And a B-spline curve fitting algorithm based on Relative center deviation (RCD) is introduced to fit a smooth curve to the extracted path, so that the virtual camera could have both a steady turning speed and a broad vision. A series of comparison tests were conducted to evaluate the effectiveness and efficiency of the proposed algorithms.