High-speed imaging: Applications and development

High-speed imaging has been used for visualizing vocal fold movements since the 1940s (4). Due to various drawbacks, like illumination problems, limited recording time capacity, and time-consuming analysis procedure, the technique has not been spread outside special research laboratories (2). Recently, the technique, originally designed for non-medical purposes, such as car crash tests etc., was improved by computer development and modification of digital high-speed image systems (8, 10, 11, 16, 19, 20). Improved recording quality, enhanced digital storage possibilities, as well as semi-automatic analysis options have lead to extended applications. In this paper the following clinical examples of applications for vocal fold digital high-speed imaging will be presented and discussed in relation to stroboscopy: 1) Examination of aperiodic vibrations or unstable (chaotic) phonation; 2) Quantification of vocal fold vibrations; 3) Voice tremor analysis. Furthermore, drawback s of the recent available recording equipment and possible future development trends will be mentioned.