Hee-June Park

Imaging and Analysis of Human Vocal Fold Vibration Using Two-Dimensional (2D) Scanning Videokymography

OBJECTIVE Laryngeal videokymography and high-speed digital kymography are the currently available techniques for studying aperiodic vibration of the vocal folds. However, videokymography has a fundamental limitation that only linear portions of the vocal fold mucosa can be visualized, whereas high-speed digital kymography has the disadvantages of lack of immediate feedback during examination and considerable waiting time before kymographic visualization. We developed a new system, two-dimensional (2D) scanning videokymography, that provides a possible alternative for evaluation of the vibratory pattern of the vocal folds. Herein, we report the application of 2D scanning videokymography for visualization of vocal fold vibration in humans and an analysis of its parameters. MATERIALS AND METHODS Two young healthy volunteers (one man and one woman) took part in this study. The vibratory patterns of their vocal folds were evaluated using 2D scanning videokymography and laryngeal stroboscopy. RESULTS Two-dimensional scanning videokymography provided a high-definition image of the vibratory movements of the vocal folds. In analysis of the images acquired by the device, various parameters including fundamental frequency; ratio of the vibratory phases; phase, amplitude, and glottal area symmetry; and cycle-to-cycle variability were extracted. CONCLUSIONS Our results indicate that 2D scanning videokymography is a useful and promising tool for visualization of the vibratory movement of the vocal folds. This new technique might improve our understanding of the mechanism of vocal fold vibration and contribute to voice research as well as clinical practice.

The First Application of the Two-Dimensional Scanning Videokymography in Excised Canine Larynx Model

OBJECTIVE Evaluation of the vibratory pattern of vocal folds is of paramount importance to diagnose vocal fold disorders. Currently, laryngeal videokymography (VKG) and digital kymography from high-speed videolaryngoscopy are the available techniques for studying aperiodic vibrations of vocal folds. But VKG has the fundamental limitation that only linear portion of the vocal fold mucosa can be visualized. Digital kymography has the disadvantages of no immediate feedback during examination, considerable waiting time before kymographic visualization, recoding duration limited to seconds, and extreme demands on storage space. We developed a new system--two-dimensional (2D) scanning VKG--for evaluation of the vibratory pattern of vocal folds, and the method provided a possible alternative with its advantages and disadvantages. Thus, we aimed to evaluate the feasibility of the new device for the vocal fold vibration in excised canine larynx model. METHODS The vibrating pattern for vocal folds was evaluated using high-speed videolaryngoscopic and 2D scanning videokymographic system in the excised canine larynx model. RESULTS The images of canine vocal folds were captured with high-speed videolaryngoscopic system and converted to the kymographic images using the software. The kymographic image acquired by 2D scanning VKG was comparable with multi-line digital kymography at multiple locations. CONCLUSIONS The vocal fold vibration could be evaluated in the excised canine larynx model using 2D scanning VKG. And this new device is expected to be a promising tool to evaluate the vocal fold vibration for clinical practice and voice research.

A new videokymography system for evaluation of the vibration pattern of entire vocal folds

OBJECTIVE To overcome the limitations of previous videokymography methods, we developed a new videokymography system for the evaluation of the whole mucosal wave of the entire vocal cord mucous membrane. METHODS To confirm the usefulness of the new videokymography system, we performed videokymography to evaluate the mucosal wave of the vocal folds during modal and falsetto phonation in normal adult males. Additionally, we serially performed both laryngeal videostroboscopy and the new videokymography method in patients diagnosed with acute ulcerative laryngitis. RESULTS Using the new videokymography system, the mucosal wave pattern of entire vocal folds was captured during the examination. The opening and closing durations could be differentiated, and the symmetry of amplitude and phase could be assessed. The shape of the medial and lateral peaks could be assessed. In patients with acute laryngitis, the new videokymography system showed an enhanced ability to evaluate the flexibility of the vocal folds. CONCLUSION The new videokymography system enables recording of the whole mucosal wave pattern of entire vocal folds. Although further studies are required to confirm its clinical efficacy for the evaluation of vocal folds, the system can be applied to evaluate the static and dynamic status of vocal folds in patients with vocal cord diseases.

Real-time Simultaneous DKG and 2D DKG Using High-speed Digital Camera

INTRODUCTION For the evaluation of voice disorders, direct observation of vocal cord vibration is important. Among the various methods, laryngeal videostroboscopy (LVS) is widely used, but it was not a true image because it collects images from different cycles. In contrast, high-speed videoendoscopy and videokymography have much higher frame rates and can assess functional and mobility disorders. OBJECTIVE The purpose of the study is to describe real-time, simultaneous digital kymography (DKG), two-dimensional scanning (2D) DKG, and multi-frame (MF) LVS system using a high-speed digital camera, and identify the efficacy of this system in evaluating vibratory patterns of pathologic voice. METHODS The pattern of vocal fold vibration was evaluated in a vocally healthy subject and in subjects with vocal polyp, vocal nodules, vocal cord scar, and vocal cord paralysis. We used both quantitative (left-right phase symmetry, amplitude symmetry index) and qualitative (anterior-posterior phase symmetry) parameters for assessment of vocal fold vibration. RESULTS Our system could record videos within seconds and required relatively little memory. The speed of replay in the DKG, 2D DKG, MF LVS, and high-speed videoendoscopy was controllable. The number of frame per cycle with MF LVS was almost the same as the fundamental frequency. CONCLUSION Our system can provide images of various modalities simultaneously in real time and analyze morphological and functional vibratory patterns. It can be possible to provide a greater level of information for the diagnosis and treatment of vibratory disorders.

Intracordal auricular cartilage injection for unilateral vocal fold paralysis

We evaluated the efficacy and outcome of intracordal auricular cartilage injection in patients with unilateral vocal fold paralysis. Our interest developed from findings of a canine model study that reported that histologic characteristics of cartilage were preserved 2 and 3 years after intracordal autologous cartilage injection. Between May 2002 and July 2010, 29 patients with breathy dysphonia caused by unilateral vocal fold paralysis underwent intracordal auricular cartilage injection. Each subject underwent preoperative and postoperative perceptual assessments, acoustical voice analysis, and videostroboscopy. Fourteen patients were male, and the mean age was 52-years old. Patients were tracked for a mean duration of 257 days. Injections were performed through a transoral approach under general anesthesia. Perceptual assessments by GRBAS scale, acoustic parameters of jitter, shimmer, noise-to-harmonic ratio, and maximum phonation time significantly improved at 3, 6, and 12 months after cartilage injection (p < 0.005). No major complications were observed after injection. Initial clinical results with intracordal auricular cartilage injection are promising for patients with unilateral vocal fold paralysis. Autologous auricular cartilage can be a safe, effective, and alternative material for vocal fold medialization, and can be a long lasting one.

The Effect on Intervention Program and Auditory-Perceptual Discrimination Feature of Postlingual Cochlear Implant Adults about Pathological Voice

In the present study, we investigated ability of recognition of auditory perception with regards to the quality of voice in postlingual CI adults and proposed a training program to improve within subject reliability. A prospective case-control study was conducted in adults with 7 postlingual deaf who received a CI surgery and 10 normal hearing controls. The pre and post test and training program included parameters of consensus auditory-perceptual evaluation of voice(CAPE-V) with pathological voice sample by using Alvin. In results of pre-post test for monitoring improvements of internal reliability for listeners via the training program, there was statistically significant difference in both test and group. There was statistically significant difference in internal reliability between pre-post test in the normal hearing group, the result was no significant in the CI group. The present study found that CI adults showed less ability in awareness of voice quality compared to normal hearing group. Also the training program improved pitch and loudness in CI adults.