State of the art laryngeal imaging: research and clinical implications

Deliyski, Dimitar D.; Hillman, Robert E.

doi:10.1097/moo.0b013e3283395dd4

Cited by 79 publications

(55 citation statements)

References 50 publications

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“…1 The oscillations extend primarily in the medio-lateral and vertical directions. 2,3 During phonation, vocal fold movement is similar to a wave motion of the vocal fold surface starting inferiorly and continuing along the medial surface toward the superior surface of the vocal folds. 4,5 In-vivo and ex-vivo analysis of the full larynx during phonation mainly permits observation, imaging, and quantification of the superior surface of the vocal folds and the vocal fold edges.…”

Section: Introductionmentioning

confidence: 99%

Dynamic vocal fold parameters with changing adduction in ex-vivo hemilarynx experiments

Döllinger

Berry

Kniesburges

2016

The Journal of the Acoustical Society of America

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Ex-vivo hemilarynx experiments allow the visualization and quantification of three-dimensional dynamics of the medial vocal fold surface. For three excised human male larynges, the vibrational output, the glottal flow resistance, and the sound pressure during sustained phonation were analyzed as a function of vocal fold adduction for varying subglottal pressure. Empirical eigenfunctions, displacements, and velocities were investigated along the vocal fold surface. For two larynges, an increase of adduction level resulted in an increase of the glottal flow resistance at equal subglottal pressures. This caused an increase of lateral and vertical oscillation amplitudes and velocity indicating an improved energy transfer from the airflow to the vocal folds. In contrast, the third larynx exhibited an amplitude decrease for rising adduction accompanying reduction of the flow resistance. By evaluating the empirical eigenfunctions, this reduced flow resistance was assigned to an unbalanced oscillation pattern with predominantly lateral amplitudes. The results suggest that adduction facilitates the phonatory process by increasing the glottal flow resistance and enhancing the vibrational amplitudes. However, this interrelation only holds for a maintained balanced ratio between vertical and lateral displacements. Indeed, a balanced vertical-lateral oscillation pattern may be more beneficial to phonation than strong periodicity with predominantly lateral vibrations.

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Section: Introductionmentioning

confidence: 99%

Dynamic vocal fold parameters with changing adduction in ex-vivo hemilarynx experiments

Döllinger

Berry

Kniesburges

2016

The Journal of the Acoustical Society of America

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“…Observation of the larynx during phonation is performed with either direct or indirect methods. The direct methods, such as videostrobolaryngoscopy (Bless et al, 1987), videokymography (Švec and Schutte, 1996) or high-speed videoendoscopy (Rubin and LeCover, 1960;Moore et al, 1962;Hertegård, 2005;Deliyski et al, 2008;Deliyski and Hillman, 2010), provide insights into the spatiotemporal oscillatory behaviour of laryngeal tissue. However, they are semi-invasive (not well tolerated by some subjects), cost intensive, and usually only performed by trained personnel in dedicated premises such as voice clinics.…”

Section: Introductionmentioning

confidence: 99%

Glottal opening and closing events investigated by electroglottography and super-high-speed video recordings

Herbst

Lohscheller

Švec

et al. 2014

Journal of Experimental Biology

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Previous research has suggested that the peaks in the first derivative (dEGG) of the electroglottographic (EGG) signal are good approximate indicators of the events of glottal opening and closing. These findings were based on high-speed video (HSV) recordings with frame rates 10 times lower than the sampling frequencies of the corresponding EGG data. The present study attempts to corroborate these previous findings, utilizing super-HSV recordings. The HSV and EGG recordings (sampled at 27 and 44 kHz, respectively) of an excised canine larynx phonation were synchronized by an external TTL signal to within 0.037 ms. Data were analyzed by means of glottovibrograms, digital kymograms, the glottal area waveform and the vocal fold contact length (VFCL), a new parameter representing the time-varying degree of 'zippering' closure along the anterior-posterior (A-P) glottal axis. The temporal offsets between glottal events (depicted in the HSV recordings) and dEGG peaks in the opening and closing phase of glottal vibration ranged from 0.02 to 0.61 ms, amounting to 0.24-10.88% of the respective glottal cycle durations. All dEGG double peaks coincided with vibratory A-P phase differences. In two out of the three analyzed video sequences, peaks in the first derivative of the VFCL coincided with dEGG peaks, again co-occurring with A-P phase differences. The findings suggest that dEGG peaks do not always coincide with the events of glottal closure and initial opening. Vocal fold contacting and de-contacting do not occur at infinitesimally small instants of time, but extend over a certain interval, particularly under the influence of A-P phase differences.KEY WORDS: Electroglottography, dEGG double peaks, Highspeed video, Vocal fold contact length, Excised canine larynx, Glottal opening and closing events

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“…Motion recording may be performed using stroboscopy or with high speed imaging. 6 Despite the advances of CCD chip technology, video resolution has always lagged the photographic quality of digital cameras. From the initial analog resolution of 250 lines of resolution to broadcast quality limit of 700 × 480 on NTSC systems, the resolution of video monitors have always been less clear than photographs.…”

Section: Discussionmentioning

confidence: 99%

4K Video-Laryngoscopy and Video-Stroboscopy

Woo

2015

Ann Otol Rhinol Laryngol

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Introduction: 4K video is a new format. At 3840 × 2160 resolution, it has 4 times the resolution of standard 1080 high definition (HD) video. Magnification can be done without loss of resolution. This study uses 4K video for videostroboscopy. Material and Method: Forty-six patients were examined by conventional video-stroboscopy (digital 3 chip CCD) and compared with 4K video-stroboscopy. The video was recorded on a Blackmagic 4K cinema production camera in CinemaDNG RAW format. The video was played back on a 4K monitor and compared to standard video. Pathological conditions included: polyps, scar, cysts, cancer, sulcus, and nodules. Results: Successful 4K video recordings were achieved in all subjects using a 70° rigid endoscope. The camera system is bulky. The examination is performed similarly to standard video-stroboscopy. Playback requires a 4K monitor. As expected, the images were far clearer in detail than standard video. Stroboscopy video using the 4K camera was consistently able to show more detail. Two patients had diagnosis change after 4K viewing. Conclusion: 4K video is an exciting new technology that can be applied to laryngoscopy. It allows for cinematic 4K quality recordings. Both continuous and stroboscopic light can be used for visualization. Its clinical utility is feasible, but usefulness must be proven.

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State of the art laryngeal imaging: research and clinical implications

Cited by 79 publications

References 50 publications

Dynamic vocal fold parameters with changing adduction in ex-vivo hemilarynx experiments

Dynamic vocal fold parameters with changing adduction in ex-vivo hemilarynx experiments

Glottal opening and closing events investigated by electroglottography and super-high-speed video recordings

4K Video-Laryngoscopy and Video-Stroboscopy

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