Hemilarynx experiments: Statistical analysis of vibrational parameters over changing glottal conditions

Ex-vivo hemilarynx experiments allow the visualization and quantification of three-dimensional dynamics of the medial vocal fold surface. For three excised human male larynges, the vibrational output, the glottal flow resistance, and the sound pressure during sustained phonation were analyzed as a function of vocal fold adduction for varying subglottal pressure. Empirical eigenfunctions, displacements, and velocities were investigated along the vocal fold surface. For two larynges, an increase of adduction level resulted in an increase of the glottal flow resistance at equal subglottal pressures. This caused an increase of lateral and vertical oscillation amplitudes and velocity indicating an improved energy transfer from the airflow to the vocal folds. In contrast, the third larynx exhibited an amplitude decrease for rising adduction accompanying reduction of the flow resistance. By evaluating the empirical eigenfunctions, this reduced flow resistance was assigned to an unbalanced oscillation pattern with predominantly lateral amplitudes. The results suggest that adduction facilitates the phonatory process by increasing the glottal flow resistance and enhancing the vibrational amplitudes. However, this interrelation only holds for a maintained balanced ratio between vertical and lateral displacements. Indeed, a balanced vertical-lateral oscillation pattern may be more beneficial to phonation than strong periodicity with predominantly lateral vibrations.

The Effect of Vocal Fold Inferior Surface Hypertrophy on Voice Function in Excised Canine Larynges

Background and Aims Remote ischemic preconditioning (RIPC) is a process in which a brief period of ischemia is induced in one part of the body to protect another part from damage due to subsequent periods of more severe ischemia. Hemodialysis sessions are considered an ischemic process because it involves reducing blood flow to certain parts of the body, which can lead to tissue damage .Malnutrition, deterioration of cognitive function, bone disorders, cardiovascular disease, and hemodynamic instability can result from ischemia induced by hemodialysis sessions. These adverse effects increase mortality in HD patients. RIPC has been studied as a potential therapeutic strategy to reduce the risk of cardiovascular events in hemodialysis patients; however, the effect of RIPC on cognitive function, nutritional status, and bone disorder among hemodialysis patients has not been enough studied. Aim: to assess the effect of remote ischemic preconditioning on nutritional status, bone disorders, and cognitive function in hemodialysis patients at the urology and nephrology center, Mansoura University. Method Fifty patients who received regular hemodialysis for more than one year in our dialysis unit were included. The patients were randomized (single-blind) into two groups a control group (20 patients) and an intervention group (30 patients). Before each HD session, sphygmomanometer cuffs was placed around the non-vascular access arm. Three cycles of ischemia for five minutes were performed followed by reperfusion for five minutes. Ischemia was induced by inflating the sphygmomanometer cuffs to 200 mmHg. This maneuver was done before each HD session for 12 weeks. The Montreal Cognitive Assessment (MOCA) was used to assess cognitive function. The nutritional state was assessed by anthropometric measurement (body weight, BMI), laboratory (serum albumin and serum cholesterol), and Subjective Global Assessment Form (SGA). Serum calcium (s.Ca) and serum phosphorus (s.po), serum alkaline phosphate (s. ALP) and intact parathyroid hormone (iPTH) were used as indices for bone profile. Results The intervention group include 30 patient with mean age (36+/-10), 19 male (63.3%) and 11 females (36.7%). The control group include 20 patient with mean age (46+/-9), 12 male (60%) and eight female (40%). None of these patients’ demographic data (age, sex, original kidney disease, and duration of dialysis) were significantly different between the study groups (P>0.05). MOCA test score at baseline was (24.5 +/-2.6) at intervention group and (24.4+/-3.2) at control group, and after 12 weeks intervention was (24.8 +/-2.2) at intervention group and (24.4+/-2.8) at control group. there were no statistical significance regarding cognitive function between the two group over time (p = 0.4). NO significant Statistical changes in anthropometric measurements (Body weight (p = 0.3) and BMI (P = 0.6) were found between the two groups. Additionally, no significant changes (serum albumin and cholesterol) were detected. SGA score at baseline was at intervention group (1.2+/-0.4) and control group (1.1 +/- 0.3), and after 12 week was at the intervention group (1.4 +/-0.5) and control group (1.6 +/-0.5). SGA showed no statistical significance between the two groups over time (p = 0.2). No significant statistical changes regarding bone profile (s.ca (p = 0.5), s.PO (p = 0.2), s.ALP (p = 0.7) and iPTH (p = 0.5)). Conclusion Although some studies showed a beneficial effect of RIBC on reduction of cardiovascular risk, our study found no significant effect on cognitive function, nutritional status, and bone disorders among hemodialysis patients.

The clinical assessment of aerodynamic parameters is important in the physiology and pathophysiology of laryngeal function. Vocal efficiency is among these objective measurements and can be calculated from simultaneous recordings of subglottic pressure, airflow, and sound intensity. Modern techniques allow us to accurately determine sound intensity and airflow. However, methods to determine subglottic pressure are either invasive or laborious. We have evaluated a noninvasive, indirect method to determine subglottic pressure by using a technique based on the interruption of transglottic airflow during phonation. The correlation between the indirectly acquired subglottic pressure measured in the oral cavity by using this technique and the subglottic pressure obtained directly by translaryngeal puncture in human volunteers was highly significant in 35 trials (r = .92, p less than .01). This study describes a reliable technique for the noninvasive measurement of subglottic pressure, sound intensity, and airflow.

Women have a higher rupture risk of intracranial aneurysms than men. One possible explanation is that aneurysm volume and shape irregularity, both linked to rupture risk, may differ between women and men. We investigated this with 3-dimensional morphological aneurysm parameters. In a random sample of consecutive patients with unruptured intracranial aneurysms diagnosed between 2008 and 2018, we quantified volume and shape parameters describing global (sphericity, elongation, and flatness) and local shape (shape index and curvedness) on CT or MR angiography scans. We compared these parameters between women and men (reference) with univariable and multivariable linear regression analysis (global parameters) and binary logistic regression analysis (local parameters). The multivariable analysis was adjusted for the confounders: age, hypertension, smoking status, aneurysm size, location, and imaging modality. We included 326 patients (239 women [73%], mean age 58 years [SD 12 years]). Women had smaller aneurysm volumes than men in multivariable analysis (β -0.30 SD, 95%CI -0.55 to -0.06). The global shape parameters sphericity, elongation, and flatness were comparable between sexes. Of the local shape parameters, women had higher aneurysm shape index (OR 2.38, 95%CI 1.03 to 5.49) and lower curvedness (OR 0.50, 95%CI 0.29 to 0.88) in multivariable analysis. Women have intracranial aneurysms with smaller volumes and shape characteristics associated with lower rupture risk. Therefore, factors other than aneurysm morphology are likely responsible for the higher risk of aneurysm rupture in women.

Despite the importance of the adaptive process for discriminating the broad range of sound intensity, there have been few systemic investigations targeting the auditory mechanisms. In this study, the adaptation effect of sound intensity on the change in glucose metabolism in rat brains was examined using a PET technique. In the first experiment, broadband white noise sound (40, 60, 80, or 100 dB sound pressure level) was given for 30 min after an 2-[F-18]-fluoro-2-deoxy-D-glucose injection in an awake condition. In the second experiment, sound stimuli with an intensity modulation of 0, 0.5, and 5.0 Hz in frequency and at three intensity levels were used for examining the metabolism change according to the short time scale variation of the sound intensity. As a result, the metabolic activities in the bilateral cochlear nucleus, superior olivary complexes, and inferior colliculus were proportional to the sound intensity level, whereas the bilateral auditory cortical areas unexpectedly decreased as the sound intensity level increased in the first experiment. In the second experiment, the glucose metabolism in the auditory cortex was higher at 0.5 and 5.0 Hz modulation frequency than the 0.0 Hz modulation frequency, while retaining an inverse relationship with the sound intensity. The metabolism in inferior colliculus was higher at 5.0 Hz modulation frequency than 0.0 and 0.5 Hz modulation frequencies. Taken together, the auditory cortex metabolism seemed to be actively adapted to the average sound intensity, which indicates that it plays an important role in processing the broad range to sound intensity more than the other nucleus of the auditory pathway. Especially, this study demonstrated that the sound intensity-dependent glucose metabolism can be seen in a small rodent's brain stem level using 2-[F-18]-fluoro-2-deoxy-D-glucose PET functional neuroimaging.

Generic wrap-around shape optimisation technology is presented, and is applied to a helicopter rotor in hover, using compressible CFD as the aerodynamic model. An efficient domain element shape parameterisation method is used as the surface control and deformation method, and is linked to a radial basis function global interpolation, to provide direct transfer of domain element movements into deformations of the design surface and the CFD volume mesh. This method is independent of mesh type and size, and optimisation independence from the flow solver is achieved by obtaining sensitivity information for an advanced parallel gradient-based algorithm by finite-difference. The method is applied here to a two-bladed hovering rotor, with transonic tip speed, comparing the effects of global twist parameters and more local planform parameters. Significant torque reductions are achieved in both cases, and it is shown that using only three global twist parameters are extremely effective. Using 63 local and global parameters, large geometric changes are demonstrated, with both induced power and wave drag reduced.

Clinical experience in the Hospital Central Militar with bilateral deep brain stimulation of ventro-medial globus pallidus in patients with Parkinson's disease

. This study investigates the geometric effects of 90-degree vertical elbows and flow configurations in two-phase flow. The study shows that the elbows make a significant effect on the transport characteristics of two-phase flow, which includes the changes in interfacial structures, bubble interaction mechanisms and flow regime transition. The effect of the elbows is characterized for global and local two-phase flow parameters. The global two-phase flow parameters include two-phase pressure, interfacial structures and flow regime transition. In order to characterize the frictional pressure drop and minor loss across the vertical elbows, pressure measurements are obtained across the test section over a wide range of flow conditions in both single-phase and two-phase flow conditions. A two-phase pressure drop correlation analogous to Lockhart-Martinelli correlation is proposed to predict the minor loss across the elbows. A high speed camera is employed to perform extensive flow visualization studies across the elbows in vertical upward, horizontal and vertical downward sections and modified flow regime maps are proposed. It is found that modified flow regime maps immediately downstream of the vertical upward elbow deviate significantly from the conventional flow regime map. A qualitative assessment of the counter-current flow limitation characteristics specific to the current experimental facility is performed. A multi-sensor conductivity probe is used to measure local two-phase flow parameters such as: void fraction, bubble velocity, interfacial area concentration and bubble frequency. The local measurements are obtained for six different flow conditions at ten measurement locations along axial direction of the test section. Both the vertical-upward and vertical-downward elbows have a significant impact on bubble distribution, resulting in, a bimodal distribution along the horizontal radius of the tube cross-section and migration of bubbles towards the inside of the elbow curvatures immediately downstream of the vertical-upward and vertical-downward elbows, respectively. The elbow effect decays further downstream of the elbow and bubbles migrate to more conventional distribution patterns. The axial transport of void fraction and interfacial area concentration shows that the elbows promote bubble disintegration. Preliminary comparisons between the interfacial area transport model and the experimental data for verticalupward and vertical downward section are also presented.

Gender- and Age- Stratified Normative Voice Data in Japanese-Speaking Subjects: Analysis of Sustained Habitual Phonations

Subglottal air pressure, airflow, and electromyographic activity of four intrinsic larygeal muscles were recorded during sustained phonation in the vocal-fry and low-frequency modal registers. Nine young adult males were subjects. In modal phonation there was greater airflow, greater cricothyroid and interarytenoid muscle activity, and decreased thyroarytenoid activity than in vocal fry. No differences were found between registers for subglottal air pressure or posterior cricoarytenoid muscle activity.

A crack detection method for steel jacket offshore platforms based on global (displacement) and local (strain) responses is presented in this paper. One side panel of an idealized three-dimensional space frame structure was used in the numerical analysis; substructuring technique in finite element method was utilized as the numerical analysis procedure. Isoparametric thin shell elements, with reduced Gaussian integration, were used to discretize the whole structure. ABAQUS finite element software was used to solve the problem and process all information relating to the above-mentioned global and local responses. Numerical results obtained in the analysis have been compared with those obtained using other types of elements available in ABAQUS. The global and local parameters (displacements and strains) have been normalized using those obtained from the uncracked structure. It has been observed that the largest changes (in strain and stress) occur around the crack, but significant changes occur even away from the cracking weld toe. For cracks occurring at "one or both" saddle point(s), significant differences in strain exist to identify whether the cracking is on one side or on both sides. Significant change in slope of normalized global displacements, obtained around the crack, indicates the location of crack.Key words: crack detection, global and local responses, substructuring.

During vocal fold vibration, the medial surface of both folds forms a convergent shape during opening and a divergent shape during closing. A greater maximum divergence angle is associated with greater closing forces which will increase the closing speed of the glottis. An increased closing speed results in a greater acoustic intensity and greater vocal efficiency. Indentation testing showed that as the strain increases, the inferior aspect of the folds becomes stiffer than the superior aspect, resulting in the vertical stiffness gradient (VSG). We hypothesize that a reduction of the vertical stiffness gradient will reduce the maximum divergence angle. Four excised canine larynges were tested. Stress-strain curves of the superior and inferior aspects of the fold in the mid membranous plane of the baseline larynges were taken using the indentation method. Calcium hydroxylapatite (CaHA) crystals were then injected into the superior aspect of the fold. The stress-strain tests were repeated. Particle imaging velocimetry (PIV) of the intraglottal velocity fields was performed in three larynges at different subglottal pressures in the mid coronal plane for the baseline and CaHA-injected larynges. CaHA injection reduced the inferior-superior stiffness gradient in all larynges. The maximal divergence angle was markedly reduced. In some cases, there was not a divergent angle. Marked reduction of the vertical stiffness gradient significantly reduces the maximum divergence angle. Clinical implications will be discussed. NA Laryngoscope, 131:E1934-E1940, 2021.

Sound intensity is a key feature of auditory signals. A profound understanding of cortical processing of this feature is therefore highly desirable. This study investigates whether cortical functional near-infrared spectroscopy (fNIRS) signals reflect sound intensity changes and where on the brain cortex maximal intensity-dependent activations are located. The fNIRS technique is particularly suitable for this kind of hearing study, as it runs silently. Twenty-three normal hearing subjects were included and actively participated in a counterbalanced block design task. Four intensity levels of a modulated noise stimulus with long-term spectrum and modulation characteristics similar to speech were applied, evenly spaced from 15 to 90 dB SPL. Signals from auditory processing cortical fields were derived from a montage of 16 optodes on each side of the head. Results showed that fNIRS responses originating from auditory processing areas are highly dependent on sound intensity level: higher stimulation levels led to higher concentration changes. Caudal and rostral channels showed different waveform morphologies, reflecting specific cortical signal processing of the stimulus. Channels overlying the supramarginal and caudal superior temporal gyrus evoked a phasic response, whereas channels over Broca’s area showed a broad tonic pattern. This data set can serve as a foundation for future auditory fNIRS research to develop the technique as a hearing assessment tool in the normal hearing and hearing-impaired populations.

288 Development of a Porcine No-Reflow Model to Investigate The Impact of Distal Coronary Embolization in Acute Myocardial Infarction