CogBioCreateKymogram is a FIJI
plugin to create videokymographic (VKG) images from high-speed movies of vocal folds during phonation. In videokymography, a line perpendicular to the glottis is scanned ca 8000 times per second with a modified video camera. Videokymography, invented in the mid-nineties by Jan G. Svec
and Harm K. Schutte, allows to observe left-right asymmetries, open quotient, propagation of mucosal waves, movement of the upper and, in the closing phase, the lower margins of the vocal folds, etc. The technique is suitable for further processing and quantification of recorded vibration. In the context with high-speed data, videokymography is useful for data reduction, and for displaying entire phonations (or parts thereof) in one image. (References)
Svec, J. (2000). On vibration properties of human vocal folds: voice registers, bifurcations, resonance characteristics, development and application of videokymography. (Doctoral Dissertation, Chapter 6
). University of Groningen, Groningen, the Netherlands.
Jan G. Svec, Harm K. Schutte, Videokymography: High-speed line scanning of vocal fold vibration, Journal of Voice
, Volume 10, Issue 2, 1996, Pages 201-205, ISSN 0892-1997, DOI: 10.1016/S0892-1997(96)80047-6. Keywords: Vibration; Vocal folds; Vocal fold vibration; Laryngoscopy; High-speed imaging; Videokymography; Stroboscopy; Vibration study
Svec JG, Sram F, Schutte HK. Videokymography in voice disorders: what to look
for? Ann Otol Rhinol Laryngol
. 2007 Mar;116(3):172-80. PubMed PMID: 17419520.
Download the plugin
: right-click the download link and save the file in the Plugins directory of your FIJI distribution (see the section 'Using a jython script as a plugin'
in the Jython Scription Tutorial
for further instructions). Open high-speed a movie in FIJI (FIJI can only handle uncompressed AVI files; use ffmpegX
on [Mac] or VirtualDub
[Windows] to convert movie if necessary). Make sure that your FIJI memory settings (Menu: Edit - Options - Memory & Threads) are sufficient to accomodate the (portion of the) high-speed movie that you want to open. Place a straight line selection (ROI) perpendicular to the glottis at the position of maximum vibratory amplitude of the vocal folds. Run the plugin to extract the videokymogram(s).
The CogBioCreateKymogram plugin can also be used in to create videostrobokymographic
images. In applying this method, the user should be aware that artifacts might be introduced into the generated image, due to the nature of videostroboscopy, and due to potential movements of camera vs. larynx introduced during the original recording.
In videostrobokymography, the concept of kymography is applied on the prerecorded video images using stroboscopy:
Sung MW, Kim KH, Koh TY, Kwon TY, Mo JH, Choi SH, Lee JS, Park KS, Kim EJ, Sung MY. Videostrobokymography: a new method for the quantitative analysis of vocal fold vibration. Laryngoscope
. 1999 Nov;109(11):1859-63. PubMed PMID: 10569423.