Validation and development of Voice Handicap Index-Throat (VHI-T) for Koreans.

INTRODUCTION: This study aimed to develop, validate, and analyze the reliability of the Korean version of the Voice Handicap Index-Throat (VHI-Tk). METHODS: This prospective study included 103 patients in the case group with voice problems (18 with functional dysphonia, 44 with mass in the larynx, 18 with neurological voice disorder, 23 with throat problems) and 27 in the control group without voice problems. All participants completed these questionnaires at their initial visit: the Korean version of the Voice Handicap Index (K-VHI), VHI-Tk, and the Korean version of the Voice Symptom Scale (K-VoiSS). Case group patients in the case group re-completed the VHI-Tk questionnaire to assess test-retest reliability. Finally, a one-way analysis of variance was implemented to assess differences in VHI-Tk scores among the four diagnosis types in the case group. RESULTS: The VHI-Tk scores in the case group were significantly higher than in the control group. The VHI-Tk was significantly correlated with the subscales of K-VHI and K-VoiSS. The VHI-Tk has significant test-retest reliability, and its internal consistency is good to excellent (Cronbach's alpha correlation coefficient range: 0.895-0.901). There was significant difference in the mean VHI-Tk scores according to the four diagnosis types (throat problems group > neurological voice disorder group). CONCLUSION: We validated the VHI-T questionnaire to measure self-perceived voice and throat problems among Koreans. A large sample size and various diagnosis types are required in future studies to fully validate the VHI-T for use in multiple cultures.

An arrayed optofluidic system for three-dimensional (3D) focal control via electrowetting.

A new lens capability for three-dimensional (3D) focal control is presented using an optofluidic system consisting of n × n arrayed liquid prisms. Each prism module contains two immiscible liquids in a rectangular cuvette. Using the electrowetting effect, the shape of the fluidic interface can be rapidly adjusted to create its straight profile with the prism's apex angle. Consequently, an incoming ray is steered at the tilted interface due to the refractive index difference between two liquids. To achieve 3D focal control, individual prisms in the arrayed system are simultaneously modulated, allowing incoming light rays to be spatially manipulated and converged on a focal point located at Pfocal (fx, fy, fz) in 3D space. Analytical studies were conducted to precisely predict the prism operation required for 3D focal control. Using three liquid prisms positioned on the x-, y-, and 45°-diagonal axes, we experimentally demonstrated 3D focal tunability of the arrayed optofluidic system, achieving focal tuning along lateral, longitudinal, and axial directions as wide as 0 ≤ fx ≤ 30 mm, 0 ≤ fy ≤ 30 mm, and 500 mm ≤ fz ≤ ∞. This focal tunability of the arrayed system allows for 3D control of the lens's focusing power, which could not be attained by solid-type optics without the use of bulky and complex mechanical moving components. This innovative lens capability for 3D focal control has potential applications in eye-movement tracking for smart displays, autofocusing of smartphone cameras, or solar tracking for smart photovoltaic systems.

Estimating the Total Societal Cost of a Hexavalent Vaccine versus a Pentavalent Vaccine with Hepatitis B in South Korea.

In South Korea, the ready-to-use hexavalent vaccine (against diphtheria, tetanus, pertussis, poliovirus, Haemophilus influenzae type b, and hepatitis B) is not listed despite its facility of no need to reconstitute. It, therefore, has the potential to augment the efficiency of prevention against the six infectious diseases, and it may reduce vaccine-related errors of reconstitution when compared with the currently used vaccination scheme of the pentavalent vaccine with the additional shots against hepatitis B. Given the assumed clinical equivalence between the two vaccination schemes, a cost-minimization analysis has been performed from a societal perspective including all the medical and non-medical direct and indirect costs when vaccinating one birth cohort. The results indicate that the ready-to-use hexavalent vaccine induces a cost reduction of KRW 47,155 (USD36.22) per infant or 12,026 million Korean Won ($9,236,417) in total for the whole birth cohort with 260,500 children. Using the ready-to-use hexavalent vaccine causes a lower infection rate, has fewer vaccination sessions, and may save much time as compared with the current vaccination scheme in place. The ready-to-use hexavalent vaccine may, therefore, benefit the National Immunization Program by reducing the total societal costs of vaccination while improving convenience of infants, parents, and medical care professionals.

The Usefulness of Multi Voice Evaluation for Measuring Voice Recovery After Endolaryngeal Phonomicrosurgery in Patients with Vocal Fold Polyps.

OBJECTIVES: The purpose of this study was to the usefulness of a five-variable model predicting perceived voice severity and incorporating acoustic analysis based on cepstral analysis and self-reported questionnaires, for measuring voice recovery after endolaryngeal phonomicrosurgery in patients with vocal fold polyps. METHODS: In this study, 72 patients with vocal fold polyps were included. Two voice evaluations, including acoustic analysis, self-reported questionnaires, and auditory perceptual assessments for each patient, were implemented before and after endolaryngeal phonomicrosurgery. Using these evaluations, we compared the mean values of the perceptual evaluation of voice, acoustic analysis parameters, self-reported questionnaires, and the five-variable model estimated severity pre- and post-endolaryngeal phonomicrosurgery. RESULTS: Various parameters related to acoustic analysis, self-reported questionnaires, and auditory perceptual assessments were useful for measuring voice recovery after endolaryngeal phonomicrosurgery. In particular, a five-variable model incorporating spectral/cepstral analyses and self-reported questionnaires was able to effectively track voice changes after endolaryngeal phonomicrosurgery. CONCLUSION: We verified that most of the variables and the five-variable model were useful for measuring voice recovery in patients with vocal polyps after endolaryngeal phonomicrosurgery.

The usefulness of multi voice evaluation: Development of a model for predicting a degree of dysphonia.

OBJECTIVES: The purposes of this study were (1) to analyze the usefulness of self-report questionnaires, acoustic analysis, and auditory perceptual assessment for screening voice problems; and (2) to develop a new model for predicting a comprehensive voice severity using multi-assessment. METHODS: A total of 306 voice samples were analyzed in this study (typical group, n = 72; dysphonia group, n = 234). We performed a receiver operating characteristic analysis to determine the cutoff values of auditory perceptual assessments (visual analog scale), acoustic parameters (spectral- and cepstral-based analyses), and self-report questionnaires for screening voice disorders. We also performed a stepwise multiple regression analysis to verify which combination of parameters (acoustic parameters, and self-report questionnaires) could best predict perceived voice severity. RESULTS: We verified that most of the variables analyzed were useful for voice evaluation, and found to be useful for screening voice problems. Of these, a five-variable model was a useful to predict perceived voice severity (mean R2 = .807). The five-variable model consisted of acoustic parameters based on cepstral analysis (cepstral peak prominences in connected speech and sustained vowel task, and low versus high-frequency spectral energy ratio in connected speech task) and self-report questionnaires (total score of the Voice Handicap Index, and rumination score of the Voice Catastrophization Index). CONCLUSION: We verified that most of the variables were useful for screening dysphonia and five-variable model was a useful to predict perceived voice severity. The five-variable model could be used as an objective criterion for predicting voice severity.

A Cepstral Analysis of Pathological Voice Quality in the Korean Population using Praat.

OBJECTIVES: This study aimed to investigate the reference values for cepstral peak prominence (CPP) and smoothed CPP (CPPS) measured using Praat in Korean speakers with the normal, healthy and pathological voice. METHODS: A total of 4,524 Korean participants with vocally healthy (n = 410) and dysphonic voices (n = 4,114) participated in this study. The speech task consisted of a sustained vowel /a/ and a sentence reading the Korean passage "Walk". CPP and CPPS values were quickly and automatically measured in sustained vowel and continuous speech tasks using Praat script. Furthermore, three veteran speech language pathologists (SLPs) scored the severity of dysphonia using the GRBAS scale (grade, roughness, breathiness, asthenia, strain) and Consensus Auditory Perceptual Evaluation of Voice (CAPE-V). RESULTS: Three SLPs showed high inter- and intra-rater reliabilities (IRR) in auditory-perceptual (A-P) evaluation. Significant differences were confirmed in CPP and CPPS between the normally healthy and pathological voice groups for both voice tasks (P < 0.01). The measured values of CPP and CPPS varied depending on the laryngeal pathology. In the receiver operating characteristic (ROC) curve analysis, the CPP_Vowel (CPP_V), CPPS_V, CPP_Sentence (CPP_S), and CPPS_S cut-off values were <21.5, <12.0, <19.7, and <10.1, respectively. Through ROC curve analysis, it was confirmed that CPP and CPPS had excellent diagnostic accuracy in distinguishing disordered voice (area under the ROC: 0.951-0.966). CONCLUSION: We investigated the reference values for CPP and CPPS measured with Praat for Korean speakers and confirmed that cepstral analysis is a promising tool for differentiating pathological voice.

Awareness and Needs of Smoking Cessation Services for Female Emotional Laborers, Parcel Delivery Workers, Transportation Workers, and Construction Workers in South Korea.

Although South Korea has implemented various smoking cessation services, women who are emotional laborers, as well as parcel delivery, transportation, and construction workers, have poor access to these services. This study evaluated the smoking-related characteristics of workers in these four occupations as well as the awareness of and need for smoking cessation services. In total 808 workers in these four occupations aged 19 years and above were recruited nationwide and had their data analyzed. The participants' age, marital status, number of work hours per week, job-related stress, age when they started smoking, average number of cigarettes a day, types of tobacco products, close relationships to others who smoke, number of attempts to quit smoking, plans to quit smoking, awareness of cessation services, prior utilization of cessation services, and need for cessation services were surveyed. Compared with parcel delivery workers, female emotional laborers and transportation and construction workers had more attempts to quit smoking, plans to quit smoking, and prior utilization of smoking cessation services, moreover, construction workers had a significantly lower awareness of smoking cessation services. Parcel delivery workers need smoking cessation programs, mobile applications to help them quit smoking, and improvements in their work environments. Cessation services and education should be promoted at workplaces and among managers.

Fatty Acid Composition of Grain- and Grass-Fed Beef and Their Nutritional Value and Health Implication.

Beef contains functional fatty acids such as conjugated linoleic acid and long-chain fatty acids. This review summarizes results from studies comparing the fatty acid composition of beef from cattle fed either grass or grain-based feed. Since functional lipid components are contributed through dietary consumption of beef, the fatty acid composition is reported on mg/100 g of meat basis rather than on a percentage of total fat basis. Beef from grass-fed contains lesser total fat than that from grain-fed in all breeds of cattle. Reduced total fat content also influences the fatty acid composition of beef. A 100 g beef meat from grass-fed cattle contained 2,773 mg less total saturated fatty acids (SFA) than that from the same amount of grain-fed. Grass-fed also showed a more favorable SFA lipid profile containing less cholesterol-raising fatty acids (C12:0 to C16:0) but contained a lesser amount of cholesterol-lowering C18:0 than grain-fed beef. In terms of essential fatty acids, grass-fed beef showed greater levels of trans-vaccenic acid and long-chain n-3 polyunsaturated fatty acids (PUFA; EPA, DPA, DHA) than grain-fed beef. Grass-fed beef also contains an increased level of total n-3 PUFA which reduced the n-6 to n-3 ratio thus can offer more health benefits than grain-fed. The findings signify that grass-fed beef could exert protective effects against a number of diseases ranging from cancer to cardiovascular disease (CVD) as evidenced by the increased functional omega-3 PUFA and decreased undesirable SFA. Although grain-fed beef showed lesser EPA, DPA, and DHA, consumers should be aware that greater portions of grain-fed beef could also achieve a similar dietary intake of long-chain omega-3 fatty acids. Noteworthy, grain-fed beef contained higher total monounsaturated fatty acid that have beneficial roles in the amelioration of CVD risks than grass-fed beef. In Hanwoo beef, grain-fed showed higher EPA and DHA than grass-fed beef.

Clinical Significance of the Preoperative Thyroidectomy-Related Voice Questionnaire Score in Thyroid Surgery.

BACKGROUND: The thyroidectomy-related voice questionnaire (TVQ) is an efficient screening tool for detecting postoperative vocal dysfunction. The aim of this study was to confirm the significance of the preoperative TVQ score in thyroid surgery. METHODS: We examined 180 women who underwent total thyroidectomy with central lymph node dissection from March 2014 to May 2016. Based on the preoperative TVQ score, participants were categorized under "normal" (TVQ score <5) and "abnormal" (TVQ score ≥5) groups. The laryngoscopic examination and acoustic analysis were performed and the TVQ score assessed before and after surgery (2 weeks, 2 months, and 8 months). RESULTS: In the normal group, the TVQ score increased up to 2 months postoperatively and had decreased at 8 months postoperatively but was significantly higher than the preoperative TVQ score. In the abnormal group, the TVQ score increased up to 2 months postoperatively but had recovered similar to the preoperative TVQ score 8 months postoperatively. The preoperative TVQ score in the abnormal group moderately correlated with the final TVQ score; however, the preoperative TVQ score in the normal group did not correlate with the TVQ score 8 months postoperatively. CONCLUSION: During preoperative patient counseling, it is important to explain that voice changes without vocal cord palsy may occur postoperatively and that it may take a long time to resolve, particularly in patients with a normal preoperative TVQ score.

Resonance Characteristics in Epiglottic Cyst: Formant Frequency, Vowel Space Area, Vowel Articulatory Index, and Formant Centralization Ratio.

OBJECTIVES: Resonance characteristics can change due to alterations in the shape of the vocal tract in patients with epiglottic cysts. This study aimed to analyze the resonance characteristics before and after the surgical excision of epiglottic cysts. METHODS: Twelve male patients with epiglottic cysts were enrolled in this study. We analyzed the first and second formants (F1 and F2) in vowels /a/, /e/, /i/, /o/, and /u/, vowel space area (VSA), vowel articulatory index (VAI), and formant centralization ratio (FCR). We measured these parameters before and after the surgical excision of epiglottic cysts. RESULTS: There was a significant increase in the F1 values of /a/, VSA, and VAI, and a significant decrease in the value of FCR after the surgery. CONCLUSION: We confirmed the change in the resonance characteristics in patients with epiglottic cysts. It is considered that further studies on epiglottic cysts and resonance changes are needed in the future.

Simple technique to preserve the external branch of the superior laryngeal nerve during thyroidectomy: Clinical practicability of an attachable nerve stimulator.

OBJECTIVE: This study aimed to demonstrate the usefulness of an attachable magnetic nerve stimulator for preservation of the external branch of the superior laryngeal nerve (EBSLN) during thyroidectomy. METHODS: We retrospectively analyzed 120 female patients, of which 60 underwent thyroidectomy with an attachable magnetic nerve stimulator (magnetic group) and the remaining 60 underwent thyroidectomy with a conventional method without EBSLN identification (control group). For both groups, objective and subjective voice parameters were investigated on the day before surgery and at 2 weeks and 2 months after surgery. RESULTS: In the magnetic group, a magnetic nerve stimulator was used to ligate only the site without cricothyroid muscle (CTM) twitching, and thyroid surgery was successfully performed without damage to the EBSLN. In the control group, objective voice parameters, including fundamental frequency, voice range profile (VRP), highest VRP (VRP-H), and maximal phonation time, and the subjective thyroidectomy-related voice questionnaire score were significantly decreased at 2 months after surgery compared to preoperative values. Compared to the control group, the magnetic group did not show a significant decrease in the objective VRP and VRP-H at 2 months after surgery. CONCLUSION: The use of metallic surgical instruments with an attachable magnetic nerve stimulator may provide surgeons with real-time feedback on CTM twitching feedback and EBSLN status. Compared to direct EBSLN identification during thyroidectomy, this is a simple, easy, and noninvasive method for EBSLN preservation that is useful, especially for less-experienced surgeons.

The Usefulness of Auditory Perceptual Assessment and Acoustic Analysis as a Screening Test for Voice Problems.

BACKGROUND/AIMS: The aims of study were (1) to determine the cut-off values of parameters related to auditory perceptual assessment (visual analog scale [VAS]) and acoustic analysis (cepstral peak prominence [CPP], low-frequency/high-frequency [L/H] ratio, CPP SD, L/H ratio SD, acoustic voice quality index [AVQI], and cepstral spectral index of dysphonia [CSID]) for predicting voice problems within a Korean population, and (2) to verify the discriminative power of these cut-off values. METHODS: 1,113 voice samples were analyzed in this study. Perceptual assessments (VAS) were performed by 5 speech-language pathologists. For the acoustic analysis, cepstral parameters, CSID, and AVQI were calculated. The cut-off values of parameters predicting voice problems were obtained using receiver operating characteristic (ROC) analysis. Additionally, the sensitivity, specificity, and area under the ROC curve (AUC) were measured. RESULTS: High reliabilities were observed for the perceptual assessments. The cut-off values of parameters had a high sensitivity, specificity, and AUC. Of these, CSID was the parameter with the highest AUC values. CONCLUSION: Each parameter demonstrated a high discriminative power for classifying the presence or absence of voice problems. The results of this study could be used as an objective criterion for screening voice problems.

Validation of Acoustic Voice Quality Index Version 3.01 and Acoustic Breathiness Index in Korean Population.

OBJECTIVES: This study aimed to verify the Acoustic Voice Quality Index (AVQI) version 3.01 and the Acoustic Breathiness Index (ABI) as tools for acoustic analyses in the Korean language. METHODS: Concatenated voice samples of sustained vowels (SV) and continuous speech (CS) were collected from 151 subjects with dysphonia and 71 vocally healthy subjects. The overall voice disorder severity (grade [G] and overall severity [OS]) and breathiness severity (B) were subjected to an auditory-perceptual rating by three raters. First, we equalized the proportions of SV and CS with respect to the time lengths of the voice samples to improve the ecological validity. We then validated the AVQI and ABI in the Korean language, using our most recent dataset of 1,667 voice samples. Second, we compared the results of the acoustic analyses between the vocally healthy controls and the dysphonia groups. Third, we confirmed the concurrent validity and diagnostic accuracy using the Spearman rank-order correlation coefficient (rs) and various statistical methods (receiver operating characteristic curve, pairwise comparison, and likelihood ratio [LR] analyses). RESULTS: We observed strong inter-rater reliability for G, B, and OS. Moreover, we identified 26 standardized syllables in the CS samples (3 second voiced segments), which allowed the equalization of both voice tasks. A comparison of the two voice groups revealed statistically significant differences in the AVQI, ABI, G, B, and OS (all P < 0.01). Moreover, we identified strong correlations of the AVQI with G (rs > 0.88, P < 0.01) and OS (rs > 0.84, P < 0.01) and of ABI with B (rs > 0.87, P < 0.01). Finally, we confirmed cutoffs of 3.154 (sensitivity: 90%, specificity: 89%, LR+: 8.45, and LR-: 0.12) and 3.685 (sensitivity: 88%, specificity: 86%, LR+: 6.47, and LR-: 0.14) as optimal predictive powers for AVQI and ABI, respectively. CONCLUSION: As per our results, in a sample of Korean speakers, the AVQI and ABI exhibited strong concurrent validity for the quantification of dysphonia severity with respect to OS and B. We consider that analyses based on the AVQI and ABI will enable the discrimination and assessment of dysphonia in clinical practice.

Comparison of Cepstral Analysis Based on Voiced-Segment Extraction and Voice Tasks for Discriminating Dysphonic and Normophonic Korean Speakers.

OBJECTIVES: This study investigated whether there are differences in the discriminatory power of cepstral analysis according to the voiced-segment extraction method and voice tasks used for identifying dysphonic and normophonic Korean individuals. MATERIALS AND METHODS: A total of 2,863 subjects (2,595 subjects with and 268 subjects without dysphonia) were included in this study. The 3-second sustained vowel (SV) /a/ and one sentence of "Sanchaek" were edited and analyzed using Praat scripts. Cepstral analyses (cepstral peak prominence [CPP], smoothed cepstral peak prominence [CPPS], and low/high spectral ratio [LHRatio]) were performed using three voice tasks, namely, SV, continuous speech (CS), and extracted continuous speech (EXT) samples. Additionally, auditory-perceptual (A-P) assessments were performed by three speech language pathologists. RESULTS: Significant differences were found between dysphonic and normophonic voice groups for all cepstral parameters, except the LHRatio_EXT. Cepstral measurements of both SV and CS were highly correlated with A-P ratings. Furthermore, the diagnostic predictive power of CPP and CPPS for CS using the area under the receiver operating characteristic curve (AUC) was >0.919, the positive likelihood ratio (LR+) was ≥6.85, and the negative likelihood ratio (LR-) was ≤0.23. Additionally, for EXT, the AUC was >0.816, LR+ was 3.10, and LR- was ≤0.33. CONCLUSION: Both CS and EXT can predict dysphonia relatively well (r > 0.816). EXT showed lower predictability than the original sample (CS) analysis. Subsequent studies should implement voiced-segment extraction methods using various algorithms.

The Usefulness of Auditory Perceptual Assessment and Acoustic Analysis for Classifying the Voice Severity.

OBJECTIVE: The aims of this study were to (1) to determine the cut-off values of parameters related to auditory perceptual assessment (visual analog scale) and acoustic analysis (cepstral peak prominence, low frequency/high frequency ratio, cepstral peak prominence standard deviation, low frequency/high frequency ratio standard deviation, acoustic voice quality index, and cepstral spectral index of dysphonia) for predicting the voice severity within a Korean population; and (2) to verify the discriminative power of these cut-off values. METHODS: Voice samples of 1,029 subjects who visited Pusan National University Hospital, South Korea to be treated for swallowing or voice evaluation from January 2018 to December 2018 were analyzed in this retrospective study. The acoustic analysis of cepstral parameters, cepstral spectral index of dysphonia, and acoustic voice quality index were calculated using the Computerized Speech Lab and Praat software. The cut-off values of parameters predicting the voice severities were obtained using receiver operating characteristic analysis. Through this analysis, the sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) were measured. RESULTS: High reliabilities of auditory perceptual assessments were observed for the auditory perceptual assessment. The cut-off values of parameters predicting voice severities had high sensitivity, specificity, and area under the curve. CONCLUSIONS: The cut-off values of parameters predicting the voice severities demonstrated a high power to discriminate for classifying the voice severities within a Korean population. The results of this study could be used as objective criteria to screen for severities of voice disorders.

Comparison of Two Versions of the Acoustic Voice Quality Index for Quantification of Dysphonia Severity.

OBJECTIVES: The acoustic voice quality index (AVQI) is a specific acoustic indicator designed to objectively estimate dysphonia severity and measure the values of acoustic parameters based on the diagnostic category. This study compared the performance of two AVQI versions (2.02 and 3.01, v2 and v3) and PraatCPPS using a voice sample of Korean population. MATERIALS AND METHODS: Voice samples for sustained vowel and connected speech were elicited from 2257 patients across 14 diagnostic categories. Auditory-perceptual (A-P) assessments of dysphonia severity were compared to acoustic parameters of severity derived from two versions of the AVQI (v2 and v3) as well as the PraatCPPS. RESULTS: The AVQI-estimated severity (v2 and v3) and PraatCPPS severity for concatenated voice samples strongly correlated with each other and were significantly associated with A-P ratings. The AVQI (v2 and v3) and PraatCPPS showed high reliability in differentiating between pathological voice disorders. CONCLUSION: The AVQI (v2 and v3) and PraatCPPS were strongly correlated with the A-P ratings and provided valid estimates of dysphonia severity. However, the associations of the A-P ratings with the AVQIv2 were significantly stronger than those with the AVQIv3 and PraatCPPS, suggesting that the V2 outperformed the V3 and PraatCPPS.

Fingerprint-to-CH stretch continuously tunable high spectral resolution stimulated Raman scattering microscope.

Stimulated Raman scattering (SRS) microscopy is a label-free method generating images based on chemical contrast within samples, and has already shown its great potential for high-sensitivity and fast imaging of biological specimens. The capability of SRS to collect molecular vibrational signatures in bio-samples, coupled with the availability of powerful statistical analysis methods, allows quantitative chemical imaging of live cells with sub-cellular resolution. This application has substantially driven the development of new SRS microscopy platforms. Indeed, in recent years, there has been a constant effort on devising configurations able to rapidly collect Raman spectra from samples over a wide vibrational spectral range, as needed for quantitative analysis by using chemometric methods. In this paper, an SRS microscope which exploits spectral shaping by a narrowband and rapidly tunable acousto-optical tunable filter (AOTF) is presented. This microscope enables spectral scanning from the Raman fingerprint region to the Carbon-Hydrogen (CH)-stretch region without any modification of the optical setup. Moreover, it features also a high enough spectral resolution to allow resolving Raman peaks in the crowded fingerprint region. Finally, application of the developed SRS microscope to broadband hyperspectral imaging of biological samples over a large spectral range from 800 to 3600 cm-1 , is demonstrated.

Voice Recovery in a Patient with Inhaled Laryngeal Burns.

INTRODUCTION: Laryngeal burns cause long-term voice disorders due to mucosal changes of the vocal folds. Inhalation injuries affect voice production and result in changes in the mucosal thickness and voice quality. CASE REPORT: A 47-year-old woman was transferred to our department with laryngeal burns sustained during a house fire. On laryngoscopic examination, mucosal waves of both vocal folds were not visualized due to the injury caused by inhalation of high-temperature toxic smoke. Hence, voice analysis, laryngoscopic examinations, and high-speed videoendoscopy (HSV) were performed to evaluate vocal fold vibrations. An absence of mucosal waves and a breathy and strained voice with a severe grade were noted. We report that voice quality was recovered to close to the normal state through multiple treatments such as medication, voice therapy, and counseling. CONCLUSION: This paper presents the unique case of a patient with laryngeal burns, in which vibrations of the vocal folds were observed using laryngoscopic examination and HSV. Voice samples before and after treatment were also analyzed. By observing the vibration pattern of the injured vocal fold, it is expected that appropriate diagnosis and treatment planning can be established in clinical practice.

Clinical Practicability of a Newly Developed Real-time Digital Kymographic System.

BACKGROUND: A digital kymogram shows real images of vocal fold vibration. However, DKG is difficult to use in clinical practice because the recorded image cannot be seen instantaneously after examination, as considerable encoding time is required to visualize a digital kymogram. In addition, frame-by frame analysis should be implemented to evaluate high-speed videoendoscopy data, but is time- and labor-intensive. PURPOSE: The purpose of the study was to validate the clinical practicability of a real-time multislice digital kymographic system developed by the authors. We analyzed the promptness and accuracy of the examination before and after intracordal injections in patients with unilateral vocal fold paralysis. METHODS: To assess the clinical applicability of this system, six patients with unilateral vocal fold paralysis were selected. Real-time DKG was performed before and immediately after intracordal injection. We observed changes in the digital kymogram after the intracordal injection. RESULTS: Using this system, 10 scanning lines and up to five vertical pixel row could be obtained in real time, and the maximum acquisition time for the DKG image was 10 seconds. A digital kymogram of the patients could be instantaneously acquired, and whether the intracordal injection was appropriate or not. CONCLUSION: This article is the first validation study after the development of the real-time multislice digital kymographic system. Our system may be a promising tool in clinical practice for immediate assessment of the vibratory patterns of the vocal cords. More research is necessary for further clinical validation.

Efficacy of Two-dimensional Scanning Digital Kymography in Evaluation of Atrophic Vocal Folds.

OBJECTIVE: The purpose of this study was to evaluate the clinical feasibility and diagnostic accuracy of two-dimensional scanning digital kymography (2D DKG) in patients with vocal cord atrophy before and after treatment. MATERIALS AND METHODS: We analyzed the characteristics of vocal fold vibration in five patients with unilateral vocal fold paralysis and five patients with presbyphonia. In patients with vocal cord paralysis, the status before and after intracordal injection was compared. Furthermore, in patients with presbyphonia, we compared the status before and after voice therapy (Seong-Tae Kim's laryngeal calibration technique). Quantitative parameters such as amplitude and phase symmetry indices, jitter, shimmer, noise-to-harmonic ratio, and maximum phonation time and qualitative parameters such as Voice Handicap Index, glottal gap, amplitude, and phase difference were used to evaluate the pre- and post-treatment status. RESULTS: In cases of vocal cord paralysis, vibratory changes of the vocal folds before and after intracordal injection could be identified immediately using 2D DKG. In overcorrection cases, all of the measured parameters were poor except for improvement of the glottal gap. In addition, 2D DKG showed appropriately the changes in vocal cord vibration before and after voice therapy in patients with presbyphonia. CONCLUSION: Two-dimensional DKG may be a useful diagnostic tool in evaluation of the vibratory characteristics of entire vocal cords. In addition, it may also play a role in providing a decision for treatment modalities.