Real-time kymographic imaging for visualizing human vocal-fold vibratory function.

A stand-alone kymographic system for visualizing human vocal-fold vibration in real time is presented. By using a dual charge-coupled-device construction, the system not only provides kymographic images but also simultaneously presents structural images for navigating the endoscope to a desired position. With a temporal resolution of 7200 lines/s, the kymographic imaging produces a sufficient speed to investigate most types of vocal-fold vibrations. Moreover, by buffering the kymographic images during the vertical blanking periods, the system can retrieve an uninterrupted kymographic image sequence even though the television standard is used. The results from preliminary clinical evaluation present evidence that the real-time kymographic imaging substantially reduces the time required for functional evaluation of the vocal-fold vibrations.