Acoustic Wave-Induced Stroboscopic Optical Mechanotyping of Adherent Cells.

In this study, a novel, high content technique using a cylindrical acoustic transducer, stroboscopic fast imaging, and homodyne detection to recover the mechanical properties (dynamic shear modulus) of living adherent cells at low ultrasonic frequencies is presented. By analyzing the micro-oscillations of cells, whole populations are simultaneously mechanotyped with sub-cellular resolution. The technique can be combined with standard fluorescence imaging allowing to further cross-correlate biological and mechanical information. The potential of the technique is demonstrated by mechanotyping co-cultures of different cell types with significantly different mechanical properties.

Clinical and Anatomical Variation During Assessment of Maximum Glottic Angle.

INTRODUCTION: Quantitative measurement and analysis of glottic abduction is used to assess laryngeal function and success of interventions; however, the consistency of measurement over time has not been established. This study assesses the consistency of glottic abduction measurements across visits in healthy patients and anatomic factors impacting these measurements. METHODS: Review of patients with two sequential flexible stroboscopic exams over seven months from 2019-2022. Images of maximal glottic abduction were captured and uploaded into and measured with ImageJ. Cadaver heads were used to assess the impact of visualization angles on glottic measurements with a monofilament inserted into the supraglottis of each cadaver as a point of reference. Comparisons were done with a paired T-test, T-test, or Mann-Whitney U test as appropriate. RESULTS: Fifty-nine patients and twenty-six cadaveric exams were included. Absolute change in maximum glottic abduction angle (MGAA) was 6.90° (95% CI [5.36°, 8.42°]; p < 0.05). There were no significant differences in change in MGAA by gender or age. Twenty percent of patients had a change of at least 25% in their MGAA between visits. Absolute differences in glottic angle between nasal side for cadaveric measurements was 4.77 ± 4.59° (p < 0.005)-2.22° less than the change in MGAA seen over time (p = 0.185). CONCLUSION: Maximal glottic abduction angles varied significantly between visits. Factors considered to be contributing to the differences include different viewing windows between examinations due to the position and angulation of the laryngoscope and changes in patient positioning, intra- and inter-rater variations in measurement, and patient effort. LEVEL OF EVIDENCE: N/a Laryngoscope, 134:2793-2798, 2024.

Automatic Segmentation of Membranous Glottal Gap Area with U-Net-Based Architecture.

BACKGROUND: While videostroboscopy is recognized as the most popular approach for investigating vocal fold function, evaluating the numerical values, such as the membranous glottal gap area, remains too time consuming for clinical applications. METHODS: We used a total of 2507 videostroboscopy images from 137 patients and developed five U-Net-based deep-learning image segmentation models for automatic masking of the membranous glottal gap area. To further validate the models, we used another 410 images from 41 different patients. RESULTS: During development, all five models exhibited acceptable and similar metrics. While the VGG19 U-Net had a long inference time of 1654 ms, the other four models had more practical inference times, ranging from 16 to 138 ms. During further validation, Efficient U-Net demonstrated the highest intersection over union of 0.8455, the highest Dice coefficient of 0.9163, and the lowest Hausdorff distance of 1.5626. The normalized membranous glottal gap area index was also calculated and validated. Efficient U-Net and VGG19 U-Net exhibited the lowest mean squared errors (3.5476 and 3.3842) and the lowest mean absolute errors (1.8835 and 1.8396). CONCLUSIONS: Automatic segmentation of the membranous glottal gap area can be achieved through U-net-based architecture. Considering the segmentation quality and speed, Efficient U-Net is a reasonable choice for this task, while the other four models remain valuable competitors. The models' masked area enables possible calculation of the normalized membranous glottal gap area and analysis of the glottal area waveform, revealing promising clinical applications for this model. LEVEL OF EVIDENCE: NA Laryngoscope, 134:2835-2843, 2024.

Applications of Artificial Intelligence to Office Laryngoscopy: A Scoping Review.

OBJECTIVES/HYPOTHESIS: This scoping review aims to provide a broad overview of the applications of artificial intelligence (AI) to office laryngoscopy to identify gaps in knowledge and guide future research. STUDY DESIGN: Scoping Review. METHODS: Searches for studies on AI and office laryngoscopy were conducted in five databases. Title and abstract and then full-text screening were performed. Primary research studies published in English of any date were included. Studies were summarized by: AI applications, targeted conditions, imaging modalities, author affiliations, and dataset characteristics. RESULTS: Studies focused on vocal fold vibration analysis (43%), lesion recognition (24%), and vocal fold movement determination (19%). The most frequently automated tasks were recognition of vocal fold nodules (19%), polyp (14%), paralysis (11%), paresis (8%), and cyst (7%). Imaging modalities included high-speed laryngeal videos (45%), stroboscopy (29%), and narrow band imaging endoscopy (7%). The body of literature was primarily authored by science, technology, engineering, and math (STEM) specialists (76%) with only 30 studies (31%) involving co-authorship by STEM specialists and otolaryngologists. Datasets were mostly from single institution (84%) and most commonly originated from Germany (23%), USA (16%), Spain (9%), Italy (8%), and China (8%). Demographic information was only reported in 39 studies (40%), with age and sex being the most commonly reported, whereas race/ethnicity and gender were not reported in any studies. CONCLUSION: More interdisciplinary collaboration between STEM and otolaryngology research teams improved demographic reporting especially of race and ethnicity to ensure broad representation, and larger and more geographically diverse datasets will be crucial to future research on AI in office laryngoscopy. LEVEL OF EVIDENCE: NA Laryngoscope, 132:1993-2016, 2022.

The Efficiency of (videolaryngo) stroboscopy in Detecting T1a Glottic Carcinoma and Its Preliminary Stages.

OBJECTIVE: The efficiency of laryngovideostroboscopy (LVS) in detecting premalignancies of the vocal fold and early glottic cancer was determined in a prospective monocentric study. In addition, the recovery rate of the mucosal membrane on the vocal fold after surgical intervention was determined by LVS. METHODS: We included 159 patients with a leukoplakia of the vocal folds and 50 healthy controls. Clinicopathological data and LVS characteristics (amplitude, mucosal wave, nonvibratory segment, glottic closure, phase symmetry, periodicity) at the lesion site were obtained and compared with the histopathological results. LVS parameters were recorded before cordectomy and in a 12-month follow-up interval. Patients who had prior laryngosurgery, radiotherapy, or laryngeal scarring were excluded. RESULTS: Absent or greatly reduced mucosal waves were found in all patients with an invasive carcinoma, in 94% with a severe intraepithelial neoplasia (SIN III), in 38% with a moderate squamous intraepithelial neoplasia (SIN II), in 32% with a mild squamous intraepithelial neoplasia (SIN I), and in 23% with a hyperkeratosis without dysplasia. The sensitivity and specificity of LVS in predicting an invasive carcinoma based on the absence or reduction of mucosal waves was 0.96 and 0.90, respectively. Following surgical intervention, the recovery rate of the mucosal wave and amplitude was 12% in the invasive carcinoma group, 36% in the SIN III group and up to 80% for both these parameters in the SIN I, SIN II, and hyperkeratosis groups. CONCLUSION: LVS is a valid tool to identify early glottic carcinoma and its high risk premalignancy carcinoma in situ (CIS). Even when there is no definitive differentiation between SIN I and II, the invasive character of a CIS and an invasive glottic carcinoma can be identified. Especially strobosopic signs of abnormal amplitude and/or mucosal waves, particularly phoniatric halt, are an early indication for a CIS or an invasive carcinoma.

Sulcus vocalis in spasmodic dysphonia-A retrospective study.

BACKGROUND: Spasmodic dysphonia (SD) is a neurological condition of the larynx characterised by task specific, involuntary spasms of the intrinsic laryngeal muscles causing frequent voice breaks during speech. The current treatment modality involves Botulinum Toxin injections into the affected group of muscles. This has yielded satisfactory results in Adductor SD (ADSD) and mixed SD but not in Abductor SD (ABSD). Sulcus vocalis is a morphological condition of the vocal folds with invagination of the superficial epithelium into the lamina propria or deeper layers. It is characterised by breathiness in voice and hypophonia. In our voice clinic, patients diagnosed with SD were occasionally found to have a sulcus on flexible stroboscopy. Studies have revealed an asymmetric stimulation of both the adductor and abductor group of muscles in ABSD and a predominant possibly symmetric stimulation of the adductor group of muscles in ADSD. Our objective was to study any significant association between vocal fold sulcus and two groups within SD; group one being ADSD and group two being both ABSD and Mixed SD. A literature review did not reveal any studies suggesting an association between SD and vocal fold sulcus to date. METHODS: A retrospective review of the stroboscopic video recordings as well as file records of all patients diagnosed with SD between January 2016 and September 2019 was conducted at our voice clinic. The first author was the laryngologist who had diagnosed SD and its type on the basis of hearing the voice and making the patient perform various vocal tasks with and without flexible videostroboscopy. The SD patients were divided into two groups with the first group consisting of ADSD patients and the second group consisting of ABSD as well as Mixed SD patients. The presence or absence of vocal fold sulcus was noted in all the SD patients. Odds ratio was used to establish statistical significance of the presence of vocal fold sulcus in the two SD groups. RESULTS: Among the 106 patients of SD, 62 patients were males and 44 were females. A total of 84 patients were diagnosed as ADSD, 10 as ABSD and 12 as Mixed SD patients. Vocal fold sulcus was noted in 5 out of 84 patients of ADSD, 4 out of 10 patients of ABSD, and in 3 out of 12 patients of mixed SD. Odds Ratio of 7.37 (C.I. = 2.063-26.35) was obtained for the second group of patients i.e. ABSD and Mixed SD. CONCLUSION: Our study revealed a significant association between patients of SD having an abductor component (ABSD and mixed SD) and vocal fold sulcus. The two hypothesis proposed for this are the possibility of asymmetrical adductor and abductor muscle stimulation in SD being responsible for the development of a vocal fold sulcus or the primary presence of a vocal fold sulcus contributing to altered sensory feedback resulting in SD. Further study to evaluate this, as well as a study of the vocal response to medialisation procedures for patients of ABSD with sulcus is recommended.

Combined Transverse Cordotomy- Anteromedial Arytenoidectomy for Isolated Glottic Stenosis.

OBJECTIVES/HYPOTHESIS: Glottic stenosis is a discrete cause of airway compromise. We aimed to determine the surgical outcomes of transverse cordotomy with anteromedial arytenoidectomy (TCAMA), performed in the setting of isolated glottic stenosis resulting from two discrete etiologies: bilateral vocal fold paralysis (BVFP) and posterior glottic stenosis (PGS). STUDY DESIGN: Retrospective, analytic cohort study. METHODS: Twenty-six patients with isolated glottic stenosis were treated with TCAMA between 2006 and 2019. A retrospective analysis determined decannulation rates and intervals, voice outcomes, swallowing outcomes, and reoperation rates postoperatively. Outcomes between the two etiologic cohorts were compared. RESULTS: Of the 26 patients, 16/26 patients were diagnosed with PGS and 10/26 with BVFP. Eighteen patients required tracheotomies during their clinical course (11/16 PGS, and 7/10 BVFP), and 100% were ultimately decannulated. The PGS cohort required two-sided interventions more frequently than the BVFP cohort (45.5% vs. 0%, P = .066). Trach-dependent PGS patients required a longer time to achieve decannulation than BVFP patients by a factor of 2.38, although the difference was not statistically significant (102.3 days vs. 42.9 days, respectively, P = .113). Patients demonstrated a significant change in maximum phonation time but no statistically significant differences with preoperative versus postoperative voice outcomes like voice-related quality of life. All patients ultimately returned to their baseline swallow function postoperatively. CONCLUSION: TCAMA is an effective treatment for surgical rehabilitation of glottic stenosis caused by both BVFP and PGS. Patient-reported outcomes of postoperative vocal function remain consistent following surgical intervention. Additional, prospective studies with greater power are warranted to validate the contrasting outcomes observed when applying this discrete surgical technique across two distinct diagnostic cohorts in this retrospective study. LEVEL OF EVIDENCE: 4. Laryngoscope, 131:2305-2311, 2021.

Correlation of Glottic Gap and Voice Impairment in Presbyphonia.

OBJECTIVE/HYPOTHESIS: The objective of this study was to investigate the glottic gap area as a significant marker for the severity of presbyphonia as it relates to patient-reported outcome measures (Voice Handicap Index-10 [VHI-10]) and stroboscopic findings. STUDY DESIGN: Retrospective case-control study conducted in an academic tertiary voice center. METHODS: Patients seen at a tertiary voice clinic who were diagnosed with presbyphonia without other organic laryngeal pathology from January 2014 to December 2017 were included. Clinical data and laryngeal videostroboscopy videos were collected. Still images at the point of vocal process approximation during adduction were captured, and the glottic gap area was measured using ImageJ. These were compared to a control cohort. Correlations were made using Wilcoxon rank sum test, Mann-Whitney U test, and Pearson correlation coefficients. RESULTS: Thirty-three patients were included. Inter-rater reliability of glottic area measurement was strong (intraclass correlation coefficient = 0.73, P < .001). Compared to controls, presbyphonia patients had a larger glottic gap area (P < .001) and greater open-phase quotient on laryngeal videostroboscopy (P < .001). Larger glottic gap area did not correlate with patient-reported vocal function as measured by VHI-10 (P = .79) and did not correlate with presence of secondary muscle tension dysphonia (P = .99). In the presbyphonia cohort, the glottic gap area did not correlate with age (P = .29). CONCLUSIONS: Glottic gap area at the point of vocal process approximation during phonation can be reliably measured. Patients with presbyphonia have a larger glottic gap area and greater open-phase quotient on stroboscopy, but these do not correlate with patient-reported voice impairment or the presence of secondary muscle tension dysphonia (MTD). These data suggest that dysphonia severity in presbyphonia is not fully explained by a glottic gap or secondary MTD alone. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:1594-1598, 2021.

Phonation Threshold Pressure/Flow for Reflecting Glottal Closure in Unilateral Vocal Fold Paralysis.

OBJECTIVE: Previous theoretical analysis predicted that phonation threshold flow (PTF) could be a more sensitive aerodynamic measure than phonation threshold pressure (PTP) for reflecting glottal incompetence. This study investigated the feasibility of whether PTP and PTF may differentiate subjects with unilateral adductor vocal fold paralysis and paresis (UAVFP) from those without, and whether PTP and PTF could reflect the extent of incomplete glottal closure associated with UAVFP. METHODS: PTP and PTF were quantified for 13 subjects with UAVFP and 21 control subjects with normal voice, and the normalized glottal gap area (NGGA) based on videostroboscopic image analysis was quantified for subjects with UAVFP. RESULTS: Significant differences in both PTP and PTF were found between subjects with UAVFP and control subjects. Receiver operating characteristic analysis indicated a higher discriminatory ability of PTP for differentiating subjects with UAVFP from those without (area under the curve of 0.905 for PTP, 0.678 for PTF), yet a significant positive correlation was found between PTF and NGGA (Spearman's ρ = 0.571) but not between PTP and NGGA (ρ = -0.364). CONCLUSION: Results supported the feasibility of using PTP and PTF as potential diagnostic indicators for reflecting glottal closure in UAVFP, with PTP potentially more sensitive for differentiating subjects with and without incomplete glottal closure. These preliminary findings were limited by the small sample size, with further studies needed to verify whether PTF could be more sensitive for reflecting the extent of incomplete glottal closure, as predicted theoretically. LEVEL OF EVIDENCE: 3 Laryngoscope, 131:E1598-E1604, 2021.

Short- and Long-Term Stroboscopic Training Effects on Visuomotor Performance in Elite Youth Sports. Part 1: Reaction and Behavior.

PURPOSE: Recent research suggests that stroboscopic training is an effective tool to improve visual and visuomotor performance. However, many studies were limited by small samples, short training interventions, inexperienced athletes, and an exclusive focus on short-term effects. This first part of the study evaluates the short- and long-term effects of stroboscopic training on visuomotor reaction speed in elite athletes. METHODS: Forty-five young elite badminton athletes participated in this study, of which 32 (13.7 yr) were included in the final data analysis. Participants were assigned to an intervention (stroboscopic vision) or control group (normal vision). Both groups performed identical badminton-specific training drills implemented into the regular training schedule. Before and after a 10-wk training period and after a 6-wk retention interval, athletes performed a laboratory reaction test to determine EMG onset and visuomotor reaction time (VMRT). In addition, a field test investigated stroboscopic training effects on the quality of ball-racquet contact and net drop performance. RESULTS: VMRT decreased immediately after stroboscopic training (pre, 251 ms; post, 238 ms; P = 0.005, d = 0.63), and reactions remained significantly faster after the retention interval (retention, 241 ms; P = 0.041, d = 0.50). Analyses on EMG onset data suggested these adaptations were attributable to the premotor rather than the motor time. VMRT remained unchanged in the control group (pre, 252 ms; post, 256; retention, 253 ms; P > 0.99). Field test performance improvements were observed for the quality of ball-racquet contact and net drop performance; however, changes were not different between groups. CONCLUSIONS: Stroboscopic training induced short- and long-term accelerations of visuomotor reaction speed in elite badminton players. Stroboscopic eyewear may be an effective training tool to accelerate visuomotor reactions in highly skilled athletes.

Short- and Long-Term Stroboscopic Training Effects on Visuomotor Performance in Elite Youth Sports. Part 2: Brain-Behavior Mechanisms.

PURPOSE: Stroboscopic training has repeatedly been shown to improve visuomotor abilities. However, although performance improvements were attributed to visual processes, information on the neurophysiological mechanisms is missing. Part 2 of this study investigated the effects of stroboscopic training on neural visual and motor functions and its contribution to training-induced changes in visuomotor reaction time. METHODS: Forty-five young elite badminton athletes participated in this study, of which 32 (age, 13.7 yr) were included in the final data analysis. Participants were assigned to an intervention (stroboscopic vision) or control group (normal vision). Before and after a 10-wk training and after a 6-wk retention period, participants performed visual perception and reaction tasks in response to visual motion stimuli. The N2 and N2-r motion onset visual-evoked potentials, its linear combination (Vlc), and the BA6 negativity potential were determined using a 64-channel EEG. RESULTS: A significant TIME-GROUP effect was observed for the Vlc score (P = 0.019, ηp2 = 0.18), indicating a lower Vlc in the intervention group. However, post hoc tests did not reach significance. Within-subject correlation analyses revealed that changes in reaction speed were related to latency changes in N2 (r = 0.59, P < 0.001), N2-r (r = -0.64, P < 0.001), and the combined Vlc (r = 0.68, P < 0.001). Regression analyses across participants including multiple (N2/N2-r) or single (Vlc) predictors provided an explained variance of >60% (N2/N2-r, r2 = 0.62; Vlc, r2 = 0.64). No training effects or correlations were observed for the BA6 negativity. CONCLUSIONS: The results indicate that faster visuomotor reactions after stroboscopic training are accompanied by accelerated visual perception and processing, whereas motor processes seemed to be unaffected. Stroboscopic training may be promising to specifically address the visual system in visuomotor-demanding sports.

Stroboscopic Vision as a Dynamic Sensory Reweighting Alternative to the Sensory Organization Test.

CONTEXT: The sensory organization test (SOT) is a standard for quantifying sensory dependence via sway-referenced conditions (sway-referenced support and sway-referenced vision [SRV]). However, the SOT is limited to expensive equipment. Thus, a practical version of the SOT is more commonly employed-the clinical test for sensory integration in balance; however, it fails to induce postural instability to the level of SRV. OBJECTIVE: Determine if Stroboscopic vision (SV), characterized by intermittent visual blocking, may provide an alternative to the SRV for assessing postural stability. DESIGN: Descriptive laboratory study. SETTING: Research laboratory. PARTICIPANTS: Eighteen participants (9 males, 9 females; age = 22.1 [2.1] y, height = 169.8 [8.5] cm, weight = 66.5 [10.6] kg). INTERVENTION: Participants completed the SOT conditions, and then repeated SOT conditions 2 and 5 with SV created by specialized eyewear. MAIN OUTCOME MEASURES: A repeated-measures analysis of variance was completed on the time-to-boundary metrics of center-of-pressure excursion in the anteroposterior and mediolateral directions in order to determine the difference between the full-vision, SV, and SRV conditions. RESULTS: Postural stability with either SRV or SV was significantly worse than with full vision (P < .05), with no significant difference between SV and SRV (P > .05). Limits of agreement analysis revealed similar effects of SV and SRV except for unstable surface mediolateral time-to-boundary. CONCLUSIONS: In general, SV was found to induce a degree of postural instability similar to that induced by SRV, indicating that SV could be a portable and relatively inexpensive alternative for the assessment of sensory dependence and reweighting.

Is a voice-specific instrument more indicative of stroboscopy results than common clinical queries?

OBJECTIVES: To determine whether the Voice Handicap Index-10 (VHI-10) predicts diagnoses made via laryngoscopy/stroboscopy, as compared to common clinical inquiries about vocal characteristics. METHODS: We prospectively collected data from a cohort of 204 consecutive patients newly presenting for ambulatory laryngology evaluation. Each patient completed the VHI-10 and 16 concurrent mainstream queries about vocal characteristics such as weakness, breathiness, fatiguability, or inability to shout. Using the objective diagnoses made by laryngoscopy/stroboscopy as a gold standard, the area under the receiver operating characteristic curves (AUC), sensitivity, and specificity were determined. RESULTS: For unilateral vocal fold paralysis, VHI-10 scores had an AUC of 0.78 (95% CI, 0.68-0.88) and had better discrimination than 12 common clinical queries. At a threshold score of ≥11, VHI-10 sensitivity was 0.94; at a threshold of ≥31, specificity was 0.91. For laryngeal stenosis, the VHI-10 score demonstrated moderate discrimination, with an AUC of 0.79 (95% CI, 0.56-1.00) and higher discrimination than three common clinical queries. At a threshold score of ≥11, VHI-10 sensitivity was 1.00; at a threshold of ≥31, specificity was 0.89. Both VHI-10 scores and common clinical queries had low diagnostic ability for vocal fold paresis, laryngopharyngeal reflux (LPR), paradoxical vocal fold motion, and vocal fold scar or atrophy. CONCLUSIONS: The VHI-10 score is an effective diagnostic indicator of laryngoscopy/stroboscopy findings of vocal fold paralysis and laryngeal stenosis, performing better than multiple mainstream queries about vocal characteristics. VHI-10 scores and common clinical queries are limited in their ability to indicate paresis, reflux, paradoxical motion, and vocal fold scar or atrophy. LEVEL OF EVIDENCE: 2c Laryngoscope, 130:992-999, 2020.

Stroboscopic assessment of unilateral vocal fold paralysis: a systematic review.

PURPOSE: To review the relevant basic stroboscopic evaluations in unilateral vocal fold paralysis (UVFP). Our aim was twofold: (1) to determine the frequency of use of stroboscopic parameters in outcome evaluation after surgical treatment of UVFP using a Pareto diagram; and (2) to select the most relevant parameters in terms of a significant difference between pre- and post-surgical intervention for UVFP. METHODS: A systematic review in PUBMED includes studies on stroboscopic evaluation in combination with UVFP and surgical treatment. The review was limited to English studies published between 1990 and March 2018. The most frequently used stroboscopic parameters were identified using a Pareto diagram. Then, 'the percentage of significance' for the most frequently stroboscopic parameters was identified by comparing the number of studies that showed a statistically significant change in pre- and post-treatment results with the total number of studies using the same parameters. RESULTS: Seven stroboscopic parameters were nominated using the Pareto diagram. In decreasing order of citation frequency, periodicity, edge bowing, mucosal wave, glottic gap, position of vocal fold, amplitude, and symmetry have respective percentages of significance of 87.5%, 83.3%, 77.7%, 64.5%, 60%, 57.1%, and 50%. Five pertinent scales were selected for the most frequent and significant stroboscopic parameters. CONCLUSIONS: The results indicate that periodicity, edge bowing, mucosal wave, glottic gap, and position of vocal fold represent the five most frequently used and relevant stroboscopic parameters in UVFP evaluation. The current review outlines a proposal scale of these stroboscopic parameters. PROSPERO REGISTRATION NUMBER: CRD42019126786.

Multichannel stroboscopic videography (MSV): a technique for visualizing multiple channels for behavioral measurements.

Biologists commonly visualize different features of an organism using distinct sources of illumination. Such multichannel imaging has largely not been applied to behavioral studies because of the challenges posed by a moving subject. We address this challenge with the technique of multichannel stroboscopic videography (MSV), which synchronizes multiple strobe lights with video exposures of a single camera. We illustrate the utility of this approach with kinematic measurements of a walking cockroach (Gromphadorhina portentosa) and calculations of the pressure field around a swimming fish (Danio rerio). In both, transmitted illumination generated high-contrast images of the animal's body in one channel. Other sources of illumination were used to visualize the points of contact for the feet of the cockroach and the water flow around the fish in separate channels. MSV provides an enhanced potential for high-throughput experimentation and the capacity to integrate changes in physiological or environmental conditions in freely-behaving animals.

Kinetic and photonic techniques to study chemotactic signaling in sea urchin sperm.

Sperm from sea urchins are attracted by chemical cues released by the egg-a mechanism called chemotaxis. We describe here the signaling pathway and molecular components endowing sperm with single-molecule sensitivity. Chemotactic signaling and behavioral responses occur on a timescale of a few milliseconds to seconds. We describe the techniques and chemical tools used to resolve the signaling events in time. The techniques include rapid-mixing devices, rapid stroboscopic microscopy, and photolysis of caged second messengers and chemoattractants.

A comparative and correlative study of the Voice-Related Quality of Life (V-RQOL) and the Voice Activity and Participation Profile (VAPP) for voice-related quality of life among teachers with and without voice disorders.

The aim of this study was to investigate the difference and correlation between the Voice-Related Quality of Life (V-RQOL) and the Voice Activity and Participation Profile (VAPP) among teachers.The participants were 672 teachers (218 males and 454 females, male-to-female ratio = 0.48:1) whose vocal cords were examined using a Strobolaryngoscope. Questionnaire results were obtained for both the V-RQOL and the VAPP.Of the 672 participants, 322 teachers had voice disorders while 350 teachers did not. The most common voice complaint was hoarseness (n = 250), and the most common throat complaint was foreign body sensation (n = 129) in teachers with voice disorders. Chronic laryngitis (n = 162, 50.3%), vocal cord polyps (n = 92, 28.6%), and vocal cord nodules (n = 43.13.4%) were the most frequent diagnoses in teachers with voice disorders. Significant differences were seen on the V-RQOL and the VAPP scores between teachers with and without voice disorders, and between female and male teachers. Differences were also observed among teachers from different grades, and among different types of voice-related diseases. Moderate-to-strong correlations were observed between the VAPP total score and those for all the subscales of the VAPP and between the VAPP total score and the V-RQOL score (P < .001).Teachers with voice disorders have a significantly poorer voice-related quality of life than those without voice disorders, as do female teachers compared with male teachers. Different groups of voice disorders have different effects on teachers' voice-related quality of life, and primary school teachers suffer from a poorer voice-related quality of life than do high school teachers. A moderate-to-strong correlation was found between the results of the V-RQOL and the VAPP scores.

Voice Acoustic Analysis of Pediatric Vocal Nodule Patients Using Ratios Calculated With Biomedical Image Segmentation.

OBJECTIVE: The aim of this study was to determine nodules using newly developed software with a computer-assisted visual process technique for the calculation of size. The effects of the ratios of nodule base and width were evaluated with voice acoustic analysis. METHODS: A total of 72 patients with pediatric vocal nodule were evaluated. Nodules were marked with the ImageJ News program on photographs obtained from the video recordings in the videostroboscopic examination and classified according to the Shah et al scale. Segmentation was applied automatically. The ratios were taken as base of nodule/width and base of nodule/vocal cord. In the voice acoustic analysis, basic frequencies (mean F0), jitter (local %), shimmer (local %), and harmonicity (mean harmonics-to-noise [mean HNR]) were evaluated. RESULTS: A statistically significant negative correlation was determined between the mean F0 value and the nodule base/width ratio (P = 0.042, r = -0.240). A negative statistically significant relationship was determined between jitter (%) and vocal nodule base/width (P = 0.009, r = -0.305). A statistically significant positive correlation was determined between mean HNR and vocal nodule base/width (P = 0.034, r = 0.324). In discriminant analysis, correct classification of the Shah et al scale degrees of the classifying variables was 73.6%. CONCLUSION: Through collaboration with the biomedical engineering department, the results of this study determined new ratios in patients with pediatric vocal nodule. In voice acoustic analysis, the mean F0 was more affected by the width of the nodule, mean HNR was affected by the length of the base of the nodule, and jitter (%) was affected by the width of the nodule.

Detection of Arytenoid Dislocation Using Pixel-valued Cuneiform Movement.

OBJECTIVES: This study aims to assess utility of pixel-valued movement software in detecting arytenoid dislocation preoperatively. STUDY DESIGN: This is a retrospective analysis. METHODS: Twenty-seven patients diagnosed with unilateral arytenoid dislocation were included. Diagnosis of arytenoid dislocation was confirmed by lack of vocal fold paralysis on preoperative laryngeal electromyography and by intraoperative findings of cricoarytenoid dislocation. A region-tracking software algorithm developed by Zhuang et al was used to analyze 27 preoperative endoscopic videos of patients diagnosed with arytenoid dislocation. Vector analysis measuring cuneiform movement during inspiration was used as an indirect measure of arytenoid movement. Values were normalized using vocal fold length. Two raters blinded to diagnosis of arytenoid dislocation measured vocal fold length and cuneiform movement on both the dislocated and the nondislocated sides. RESULTS: A Wilcoxon signed-rank test indicated that the mean pixel-valued cuneiform movement and standard deviation (SD) were greater for nondislocated (159.24, SD = 73.35) than for dislocated (92.49, SD = 72.11) arytenoids (Z = 3.29, P = 0.001). The interrater correlation coefficient was 0.87 for the dislocated side and 0.75 for the nondislocated side. The intrarater correlation coefficient was 0.87 for the dislocated side and 0.91 for the nondislocated side. The receiver operating characteristic curve revealed an area under the curve between 0.76 and 0.83 (95% confidence interval 0.63-0.90). Analysis by the first and second raters revealed misdiagnosis of laterality of arytenoid dislocation in four and six patients, respectively. CONCLUSIONS: The software program developed by Zhuang et al provides a high-degree of precision, with good interrater and intrarater correlation coefficients. However, high rates of misdiagnosis of arytenoid dislocation and the laborious analysis process using this software program make it of limited utility as a clinical diagnostic tool in its present state.