Real-time laryngoscopic measurements of vocal-fold vibrations.

We have developed a high-frame-rate laryngoscope that can measure the vibration distribution of a human vocal fold in real time at hundreds of hertz. Our laryngoscope can extract a vocal-fold contour at 4000 fps as 20 pairs of its left and right border points from 256 × 512-pixel images to quantify left-right asymmetry of vocal-fold vibrations. Experiments on artificial vocal-fold-like vibrations of a silicon rubber membrane were performed to confirm the laryngoscope's effectiveness, and the vocal folds of human subjects, including patients with laryngeal diseases, were examined under clinical conditions.