Christopher Bohr

Multiparametric analysis of vocal fold vibrations in healthy and disordered voices in high-speed imaging.

OBJECTIVES The aim of this study was to look for visual subjective and objective parameters of vocal fold dynamics being capable of differentiating healthy from pathologic voices in daily clinical practice applying endoscopic high-speed digital imaging (HSI). STUDY DESIGN AND METHODS Four hundred ninety-six datasets containing 80 healthy and 416 pathologic subjects (232 functional dysphonia (FD), 13 bilateral, and 171 unilateral vocal fold nerve paralysis) were analyzed retrospectively. Videos at 4000Hz (256×256 pixel) were recorded during sustained phonation. Subjective parameters were visually evaluated and complemented by an analysis of objective parameters. Visual subjective parameters were mucosal wave, glottal closure type, glottal closure insufficiency (GI), asymmetries of the vocal folds, and phonovibrogram (PVG) symmetry. After image segmentation, objective parameters were computed: closed quotient, perturbation measures (PMs) of glottal area, and left-right asymmetry values. RESULTS HSI evaluation enabled to distinguish healthy from pathologic voices. For visual subjective parameters, GI, symmetrical behavior, and PVG symmetry exhibited statistical significant differences. For 95% of the data, objective parameters could be computed. Among objective parameters, closed quotient, jitter, shimmer, harmonic-to-noise ratio, and signal-to-noise ratio for the glottal area function differentiated statistically significant normal from pathologic voices. Applying linear discriminant analysis by combining visual subjective and objective parameters, accurate classifications were made for 63.2% of the female and 87.5% of the male group for the three-class problem (healthy, FD, and unilateral vocal fold nerve paralysis). CONCLUSION Actual acoustically applied PMs can be transferred to clinical beneficial HSI analysis. Combining visual subjective and objective basic parameters succeeds in differentiating pathologic from healthy voices. The presented evaluation can easily be included into everyday clinical practice. However, further research is needed to broaden our understanding of the variability within and across healthy and pathologic vocal fold vibrations for diagnosing voice disorders and therapy control.

Incidence of occult cervical metastasis in head and neck carcinomas: Development over time

With the development of imaging techniques in diagnostics of head and neck carcinomas, especially computed tomography and ultrasonogaphy, one might expect that the incidence of occult metastases would be reduced. The aim of this study was to determine the rate of occult metastases in a large population cohort and explore its changes with improvement of imaging techniques over the last 30 years.

Experiments on Analysing Voice Production: Excised (Human, Animal) and In Vivo (Animal) Approaches.

Experiments on human and on animal excised specimens as well as in vivo animal preparations are so far the most realistic approaches to simulate the in vivo process of human phonation. These experiments do not have the disadvantage of limited space within the neck and enable studies of the actual organ necessary for phonation, i.e., the larynx. The studies additionally allow the analysis of flow, vocal fold dynamics, and resulting acoustics in relation to well-defined laryngeal alterations. PURPOSE OF REVIEW This paper provides an overview of the applications and usefulness of excised (human/animal) specimen and in vivo animal experiments in voice research. These experiments have enabled visualization and analysis of dehydration effects, vocal fold scarring, bifurcation and chaotic vibrations, three-dimensional vibrations, aerodynamic effects, and mucosal wave propagation along the medial surface. Quantitative data will be shown to give an overview of measured laryngeal parameter values. As yet, a full understanding of all existing interactions in voice production has not been achieved, and thus, where possible, we try to indicate areas needing further study. RECENT FINDINGS A further motivation behind this review is to highlight recent findings and technologies related to the study of vocal fold dynamics and its applications. For example, studies of interactions between vocal tract airflow and generation of acoustics have recently shown that airflow superior to the glottis is governed by not only vocal fold dynamics but also by subglottal and supraglottal structures. In addition, promising new methods to investigate kinematics and dynamics have been reported recently, including dynamic optical coherence tomography, X-ray stroboscopy and three-dimensional reconstruction with laser projection systems. Finally, we touch on the relevance of vocal fold dynamics to clinical laryngology and to clinically-oriented research.

SFTA3, a novel protein of the lung: three-dimensional structure, characterisation and immune activation

The lung constantly interacts with numerous pathogens. Thus, complex local immune defence mechanisms are essential to recognise and dispose of these intruders. This work describes the detection, characterisation and three-dimensional structure of a novel protein of the lung (surfactant-associated protein 3 (SFTA3/SP-H)) with putative immunological features. Bioinformatics, biochemical and immunological methods were combined to elucidate the structure and function of SFTA3. The tissue-specific detection and characterisation was performed by using electron microscopy as well as fluorescence imaging. Three-dimensional structure generation and analysis led to the development of specific antibodies and, as a consequence, to the localisation of a novel protein in human lung under consideration of cystic fibrosis, asthma and sepsis. In vitro experiments revealed that lipopolysaccharide induces expression of SFTA3 in the human lung alveolar type II cell line A549. By contrast, the inflammatory cytokines interleukin (IL)-1&bgr; and IL-23 inhibit expression of SFTA3 in A549. Sequence- and structure-based prediction analysis indicated that the novel protein is likely to belong to the family of lung surfactant proteins. The results suggest that SFTA3 is an immunoregulatory protein of the lung with relevant protective functions during inflammation at the mucosal sites. SFTA3: a novel lung protein with putative protective and immunological functions during inflammation in lung diseases http://ow.ly/tsnne

Quantitative analysis of organic vocal fold pathologies in females by high-speed endoscopy.

Quantitative analysis of endoscopic high‐speed video recordings of vocal fold vibrations has been growing in importance in recent years. The videos have mainly been analyzed using subjective evaluation, but this is examiner dependent, and the results show inadequate interobserver agreement. The aims of this study were therefore to identify appropriate objective parameters for analyzing high‐speed recordings to differentiate healthy voice production from organic disorders.

Spatiotemporal Analysis of High-Speed Videolaryngoscopic Imaging of Organic Pathologies in Males

PURPOSE The aim of this study was to identify parameters that would differentiate healthy from pathological organic-based vocal fold vibrations to emphasize clinical usefulness of high-speed imaging. METHOD Fifty-five men (M age = 36 years, SD = 20 years) were examined and separated into 4 groups: 1 healthy (26 individuals) and 3 pathological (10 individuals with contact granuloma, 12 with polyps, and 7 with cysts). Vocal fold vibrations were recorded using a high-speed camera during sustained phonation. Twenty objective glottal area waveform and 24 phonovibrogram parameters representing spatiotemporal characteristics were analyzed. Statistical group comparisons were performed to document spatiotemporal changes for organic lesions that cannot be determined visually. To look for specific pattern profiles within organic lesions, the authors performed linear discriminant analysis. RESULTS Thirteen parameters showed significant differences between the healthy group and at least 1 pathological group. The differences occurred more in temporal than in spatial parameters. Contact granuloma showed the fewest statistical differences (3 parameters), followed by cysts (9 parameters), and polyps (10 parameters). Linear discriminant analysis achieved accuracy performance of 76% (all groups separated) and 82% (healthy vs. pathological). CONCLUSION The results suggest that for males, the differences between healthy voices and organic voice disorders may be more pronounced within temporal characteristics that cannot be visually detected without high-speed imaging.

Analysis of Vocal Fold Function From Acoustic Data Simultaneously Recorded With High-Speed Endoscopy

Summary Acoustic and endoscopic voice assessments are routinely performed to determine the vocal fold vibratory function as part of the voice assessment protocol in clinics. More often than not these data are separately recorded, resulting in information being obtained from two different phonation segments and an increase of time for the voice evaluation process. This study explores the use of acoustic data, simultaneously recorded during high-speed endoscopy (HSE), for the evaluation of vocal fold function. Patients and Methods HSE and acoustic data were recorded from the subjects simultaneously during sustained phonation. The data included voices of 73 healthy subjects, 148 paresis, 210 functional dysphonias, and 119 benign lesions of vocal folds. For this study, only acoustic data were analyzed using Dr. Speech software (Tiger electronics Inc., MA). Twelve parameters were computed; 82% of the acoustic voice recordings could be analyzed. Statistical analysis was performed with SPSS 17.0. Results Acoustic data was easily recorded simultaneously allowing analyses of the same phonation segment to determine vocal fold function and therefore eliminating the need for another voice recording. The acoustic voice parameters differed between genders in the healthy voice group. Most of the parameters showed significant differences between healthy and pathological groups. Conclusion Simultaneously recorded endoscopic and acoustic data is valuable. Differentiation between healthy and pathological groups was possible using acoustic data only. We suggest that the synchronously recorded acoustic signal is of sufficient quality for objective analysis yielding reduced examination time.

Automatic Classification of Cancerous Tissue in Laserendomicroscopy Images of the Oral Cavity using Deep Learning

Oral Squamous Cell Carcinoma (OSCC) is a common type of cancer of the oral epithelium. Despite their high impact on mortality, sufficient screening methods for early diagnosis of OSCC often lack accuracy and thus OSCCs are mostly diagnosed at a late stage. Early detection and accurate outline estimation of OSCCs would lead to a better curative outcome and a reduction in recurrence rates after surgical treatment. Confocal Laser Endomicroscopy (CLE) records sub-surface micro-anatomical images for in vivo cell structure analysis. Recent CLE studies showed great prospects for a reliable, real-time ultrastructural imaging of OSCC in situ. We present and evaluate a novel automatic approach for OSCC diagnosis using deep learning technologies on CLE images. The method is compared against textural feature-based machine learning approaches that represent the current state of the art. For this work, CLE image sequences (7894 images) from patients diagnosed with OSCC were obtained from 4 specific locations in the oral cavity, including the OSCC lesion. The present approach is found to outperform the state of the art in CLE image recognition with an area under the curve (AUC) of 0.96 and a mean accuracy of 88.3% (sensitivity 86.6%, specificity 90%).

Primary surgical treatment of T3 glottic carcinoma: long-term results and decision-making aspects.

The aim of this study was to assess the efficacy of primary surgical treatment in the management of T3 glottic carcinomas.

New endoscopic instruments for paranasal sinus surgery

BACKGROUND: Minimally invasive endoscopic and microscopic procedures represent state of the art paranasal sinus surgery techniques in both diagnostic and surgical fields. To combine favorable aspects of both techniques, we evaluated the clinical applicability and effectiveness of multifunctional microendoscopes, providing multiple features to ensure highest accuracy and surveillance when performing crucial steps in paranasal sinus surgery. METHODS: The study included both anatomic experiments on cadaveric heads and clinical tests on patients undergoing routine paranasal surgery. The systems applicability was evaluated in procedures approaching the frontal and sphenoid sinus. Three different endoscopes, 2 straight and the other 1 with a 90° angle, were tested. They integrate canals for flushing and suction and a working canal for either drilling or obtaining biopsies with a miniaturized forceps. For stereotactic feedback, the applicability in combination with a computer-navigation system was evaluated. RESULTS: Anatomic tests were performed to optimize illumination and to test drilling features and forceps biopsies. In all cases, the frontal sinus ostium and the sphenoid sinus anterior wall was easily identified and enlarged by drilling under visual and stereotactic control. Continuous suction and irrigation ensured a constant visual surveillance by removing drilling debris and blood. Best suited for multifunctional endoscopic surgery were drill heads with a cylinder shape, for placing bore holes along the Z axis, and spherical drill heads, for furbishing and enlarging drill holes. CONCLUSION: These new instruments have proven their applicability in paranasal sinus surgery. Multifunctional endoscopic procedures were deemed best suited for maneuvers requiring highest precision, such as the surgery of the frontal and sphenoid sinus.