Value of flexible videolaryngoscopy in the study of laryngeal morphology and functions

In the past 3 years flexible laryngoscopy was used in the evaluation of 315 patients, ranging in age from 4 months to 86 years (in 136 cases a videorecording was obtained). The technique was especially helpful in cases in which a prolonged visual evaluation of laryngeal motion was required for diagnostic, prognostic, and documentative purposes. The main limitations were lack of image definition and wide angle image distortion. Therefore, accurate evaluation of initial mucosal changes was not possible in some of the cases examined. A stroboscopic light source was used every time the characteristics of the vibratory cycle of the vocal folds had to be studied. This technique was applied mainly to the study of vocal fold vibrations in unilateral laryngeal paralysis.     

Laryngeal and pharyngeal behavior in countertenor and baritone singing—A videofiberscopic study

Changes in vocal tract configuration during singing were studied in four semiprofessional countertenors and one professional bass-baritone, by means of fiberoptic laryngoscopy. All of the countertenors showed a marked narrowing of the lower pharynx with increasing pitch when they used their countertenor voice (CT voice) but only a slight narrowing when using their baritone voice (B voice). The bass-baritone's pharynx remained unchanged with increasing pitch. Increasing loudness gave a widening of the pharynx in three of the four countertenors' CT voices, whereas no change was observed for the countertenors' B voices or for the bass-baritone voice. Vocal fold length seemed to decrease in one countertenor's B voice and in the bass-baritone with increasing loudness. Thus, the countertenors in this study exhibit several characteristic patterns of vocal tract gestures in countertenor voice that differ from both their own baritone voices and from the bass-baritone.     

Vocal fold exposure in phonosurgery

A difficult laryngeal exposure is made easier by placement of the patient's head and neck into the Boyce-Jackson “sniffing position” and then flexing them further if necessary, by selection of a laryngoscope appropriate to the patient and to the triangular glottic shape, by placement of the laryngoscope along the path of least resistance, by use of a true suspension device in order to apply the force for laryngoscopy towards the larynx and away from the teeth and gums, and by allowing time for the force to work. With these techniques, an easy exposure is made almost perfect. The true vocal folds are exposed from vocal process to anterior commissure without the need for external pressure, the endotracheal tube remains out of sight between the arytenoids, and there is no risk to the teeth, gums, and cervical spine.     

Noise-to-Harmonics Ratio as an Acoustic Measure of Voice Disorders in Boys

This prospective study assessed the efficacy of computerized noise-to-harmonics ratio (NHR) to quantify perceptual and endoscopic findings of dysphonia and/or structural lesion of the vocal fold. Fifty Brazilian boys without vocal complaints were submitted to computerized, perceptual, and endoscopic examination. Thirty boys were dysphonic--3 were classified into the grade category, 5 into breathiness, 9 into roughness, and 15 into grade/breathiness. Vocal fold lesions were observed in 25 boys (17 nodules and 8 cysts). The Mann-Whitney U test revealed that NHR was significantly higher in boys with a structural lesion (p = 0.007) and in boys with dysphonia (p < 0.0001). However, according to a logistic regression model, only the occurrence of dysphonia was explained by NHR; the risk for having dysphonia increased approximately twice (odds ratio = 1.92, 95% confidence interval = 1.3-2.9) with each increase of 0.01 in NHR. Our results suggest that noise is a useful quantitative index to confirm a perceptual diagnosis of dysphonia and to evaluate quantitative changes in a dysphonic voice over time. However, we believe that computerized analysis should be used as a complement, rather than a substitute, for perceptual evaluation. Further studies with a larger sample are required to investigate the relationship between noise and lesions of the vocal folds.     

用于光纤机敏材料与结构损伤估计的人工神经网络

本文以光纤机敏材料与结构中的损伤估计为目的,根据光纤阵列传感信号处理的需要,在给出人工神经网络处理原理与结构基础上,结合应用详细地阐述了适用的反向传播神经网络(BP)模型、自组织特征映射神经网络(Kohonen)模型及其变化形式(LVQ1,LVQ2,LVQ3,LVQ4及LVQ5等),同时给出了仿真实验的结果.     

A transient enzymatic inhibition as an efficient tool for the discriminating bioluminescent analysis of three adenylic nucleotides with a fiberoptic sensor based on a compartmentalized tri-enzymatic sensing layer

A fiberoptic biosensor has been developed for the specific and alternate determination of ATP, ADP and AMP. The sensing layer is arranged by compartmentalizing the tri-enzyme sequence adenylate kinase – creatine kinase – firefly luciferase. The two kinases are covalently co-immobilized on a collagen membrane, whereas firefly luciferase is bound alone on a separate one. For the specific determination of each adenylic nucleotide, three particular reaction media are needed with which flow-injection analysis can be performed in the 2.5–2500 pmol for ATP, 10–2500 pmol for ADP and 25–5000 pmol for AMP linear ranges. For ten consecutive injections of 100 pmol ATP, 100 and 250 pmol ADP, the RSD were 3.5, 2.0 and 2.2%, respectively. When the three nucleotides are present simultaneously in the same sample, the transient inhibition of adenylate-kinase activity by adenosine 5′-monosulphate enables their specific and alternate measurement.     

Modification of Cary 14H Spectrophotometer into a Fiberoptic Absorption Spectrophotometer

An efficient fiberoptic interface system was developed to convert a Gary 14 H spectrophotometer into a fiberoptic instrument. This new spectrophotometer can be used to study the UV-visible and near-IR absorption spectroscopy of radioactive samples and wastes in a confined environment.     

Use of flexible fiberoptic laryngoscopy to assess patients with spasmodic dysphonia

Flexible videolaryngoscopy was used to study 38 patients with spasmodic dysphonia, rating excessive activation of intrinsic laryngeal muscles, extrinsic muscle hyperfunction, tremor, and dystonic movements. Seventeen patients were also studied after unilateral botulinum toxin injection. Dysfunction varied greatly; however, discrete patterns could not be identified. Functional status correlated significantly with the total score of all pathologic indicators, but not with any single parameter. Botulinum toxin was highly effective in reducing intrinsic laryngeal muscle activation, but did not always improve tremor. Extrinsic laryngeal muscle hyperfunction was not significantly affected by the toxin