High-speed imaging of the larynx
Svante GranqvistIn this project methods for analysis of high-speed laryngoscopic image sequences are developed.
Example of high-speed recording
These recordings were made at Huddinge University Hospital, department of Logopedics and Phoniatrics. The high-speed
camera has a resolution of 256 by 64 pixels and recordings were made at approximately 1900 images per second. The
images were recorded with a flexible endoscope fed through the nose. The end of the endoscope is positioned centimeters
above the glottis. On this page, the playback speed is reduced to about 3 images per second (the factor may vary
depending on your web browser and hardware).
|Normal phonation. Every cycle is similar to the other.
F0 = 115 Hz
(Animation consists of a single cycle within 16 frames that are repeated over and over)
|Vocal fry phonation. In this recording a bicyclic oscillation pattern was produced in which the periods appear
in groups of two.
F0 = 120 Hz, F0/2 = 60Hz
(Animation consists of a single group of two cycles within 31 frames that are repeated over and over)
In my licentiate thesis we propose a metod for analysis of recordings, like the one above. The method is based
on Fourier transfomations of the light intensity at different locations in the image.