Comparative analysis of high-speed videolaryngoscopy images and sound data simultaneously acquired from rigid and flexible laryngoscope: a pilot study

Wioletta Pietruszewska,Jakub Malinowski,Magdalena Kowalczyk,Magda Barańska,Joanna Hoffman,Ewa Niebudek-Bogusz,Anna Racino,Marcin Just,Joanna Morawska

doi:10.1038/s41598-021-99948-9

Wioletta Pietruszewska, Jakub Malinowski + Show 7 more

Open Access

https://doi.org/10.1038/s41598-021-99948-9

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Abstract

High-Speed Videoendoscopy (HSV) is becoming a robust tool for the assessment of vocal fold vibration in laboratory investigation and clinical practice. We describe the first successful application of flexible High Speed Videoendoscopy with innovative laser light source conducted in clinical settings. The acquired image and simultaneously recorded audio data are compared to the results obtained by means of a rigid endoscope. We demonstrated that the HSV recordings with fiber-optic laryngoscope have enabled obtaining consistently bright, color images suitable for parametrization of vocal fold oscillation similarly as in the case of the HSV data obtained from a rigid laryngoscope. The comparison of period and amplitude perturbation parameters calculated on the basis of image and audio data acquired from flexible and rigid HSV recording objectively confirm that flexible High-Speed Videoendoscopy is a more suitable method for examination of natural phonation. The HSV-based measures generated from this kymographic analysis are arguably a superior representation of the vocal fold vibrations than the acoustic analysis because their quantification is independent of the vocal tract influences. This experimental study has several implications for further research in the field of HSV application in clinical assessment of glottal pathologies nature and its effect on vocal folds vibrations.

Highlights

High-Speed Videoendoscopy (HSV) is becoming a robust tool for the assessment of vocal fold vibration in laboratory investigation and clinical practice
From the Glottal Area Waveform (GAW) one can calculate parameters characterising vocal fold vibrations in the form of parameters exclusively connected to the GAW like the Open Quotient (OQ), i.e. the duration of the open phase within the total glottal cycle, as well as parameters which can be determined both from the GAW and acoustic signals of voice such as fundamental frequency F0 and frequency perturbation parameters, e.g. jitter and amplitude perturbation parameters e.g. s himmer[27,28,29,30]
Prior to High-Speed Videoendoscopy (HSV) examination, the Subjects of the study underwent a multidimensional assessment of vocal function according to the protocol put forward by the Committee on Phoniatrics of the European Laryngological Society (ELS) including: laryngovideostroboscopy (LVS), perceptual assessment (GRBAS), acoustic analysis of voice, self-assessment of voice (Voice Handicap Index; VHI) and aerodynamic assessment (Maximum Phonation Time; MPT)

Summary

Introduction

High-Speed Videoendoscopy (HSV) is becoming a robust tool for the assessment of vocal fold vibration in laboratory investigation and clinical practice. The comparison of period and amplitude perturbation parameters calculated on the basis of image and audio data acquired from flexible and rigid HSV recording objectively confirm that flexible High-Speed Videoendoscopy is a more suitable method for examination of natural phonation. The HSV-based measures generated from this kymographic analysis are arguably a superior representation of the vocal fold vibrations than the acoustic analysis because their quantification is independent of the vocal tract influences. High-speed videoendoscopy (HSV) of the larynx is a complementary tool to commonly used laryngovideostroboscopy (LVS) Both these tools enable the investigating of vocal fold vibratory function in normal and pathological states of glottis. The HSV recording technique enables the visualisation of the main within-glottic cycle vibratory phases, namely the opening, open, closing and closed phases (Fig. 1) This results in periodic interruption of the airflow traveling through the glottis that produces audible sound during phonation. The problem associated with this feature has been described in literature[7,31,32], the use of acoustic measures calculated on the basis of simultaneous recording of voice signals reveals useful information related to laryngeal p athophysiology[2,7,24,33,34]

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