Transoral awake state neuromuscular electrical stimulation therapy for mild obstructive sleep apnea.

INTRODUCTION: Obstructive sleep apnea (OSA) is a common disorder with major neurocognitive and cardiovascular sequelae. The treatment of symptomatic patients with mild OSA remains controversial given that adherence to positive airway pressure (PAP) has historically been suboptimal. With this notion in mind, we assessed a daily transoral neuromuscular electrical stimulation (NMES) device for individuals with mild OSA. METHODS: The sample represents a subset of participants with a baseline AHI 5-14.9 events/hour, drawn from a parent study which also included participants with primary snoring. Outcome measures for the current study included changes in apnea-hypopnea index (AHI), Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI) and snoring levels before and after use of the NMES.  RESULTS: Among 65 participants (68% men) with median age of 49 years (range 24 to 79) and median BMI of 27.7 kg/m2 (range 20 to 34), the NMES device was used daily for 6 weeks. We observed a significant improvement in the AHI from 10.2 to 6.8 events/hour among all participants and from 10.4 to 5.0 events/h among responders. Statistically significant improvements in the ESS, PSQI, objectively measured snoring, and bed partner-reported snoring were observed. Adherence among all participants was 85%. DISCUSSION: This NMES device has the benefit of being a treatment modality of daytime therapy which confers a high level of tolerability and patient acceptance. It alleviates the need for an in situ device during sleep and leads to improvements in OSA severity, snoring, and subjective sleep metrics, potentially crucial in mild OSA. Further studies are needed to define which individuals may benefit most from the device across the wider spectrum of OSA severity and assess long-term therapeutic outcomes. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03829956.

Surgical anatomy of the lingual nerve for palate surgery: where is located and how to avoid it.

PURPOSE: To describe the anatomic relationship of the lingual nerve with the lateral oropharyngeal structures. METHODS: An anatomic dissection of the lateral oropharyngeal wall was conducted in eight sides from four fresh-frozen cadaveric heads. Small titanium clips were placed along the lingual nerve and the most anterior and medial border of the medial pterygoid muscle. Radiological reconstructions were employed for optimal visualization; the coronal view was preferred to resemble the surgical position. The distance between the lingual nerve and the medial pterygoid muscle at its upper and lower portion was measured radiologically. The trajectory angle of the lingual nerve with respect to the pterygomandibular raphe was obtained from the intersection between the vector generated between the clips connecting the upper and lower portion of the medial pterygoid muscle with the vector generated from the lingual nerve clips. RESULTS: The mean distance from the upper portion of the medial pterygoid muscle and superior lingual nerve clips was 10.16 ± 2.18 mm (mean ± standard deviation), and the lower area of the medial pterygoid muscle to the lingual nerve was separated 5.05 ± 1.49 mm. The trajectory angle of the lingual nerve concerning to the vector that describes the upper portion of the most anterior and medial border of the medial pterygoid muscle with its lower part was 43.73º ± 11.29. CONCLUSIONS: The lingual nerve runs lateral to the lateral oropharyngeal wall, from superiorly-inferiorly and laterally-medially, and it is closer to it at its lower third.

Accuracy of a Laryngopharyngeal Endoscopic Esthesiometer (LPEER) for Evaluating Laryngopharyngeal Mechanosensitivity: A Validation Study in a Prospectively Recruited Cohort of Patients.

Recent studies have shown an association between alterations in laryngopharyngeal mechanosensitivity (LPMS) and dysphagia, obstructive sleep apnea, and chronic cough hypersensitivity syndrome. A previous reliability study of a new laryngopharyngeal endoscopic esthesiometer and rangefinder (LPEER) showed high intra- and inter-rater reliability; however, its accuracy has not been tested. We performed an accuracy study of the LPEER in a prospectively and consecutively recruited cohort of 118 patients at two tertiary care university hospitals. Most of the patients were suffering from dysphagia, and all of them underwent a standard clinical evaluation and fiberoptic endoscopic evaluation of swallowing with sensory testing (FEESST) using a new sensory testing protocol. The sensory test included determinations of the laryngeal adductor reflex threshold (LART), the cough reflex threshold (CRT) and the gag reflex threshold (GRT). Abnormalities on these reflex thresholds were evaluated for associations with major alterations in swallowing safety (pharyngeal residues, penetration, and aspiration). We evaluated the discriminative capacity of the LPMS test using ROC curves and the area under the curve (AUC-ROC) and its relationship with the eight-point penetration-aspiration scale (PAS) using the Spearman's ρ correlation coefficient (SCC). We found a positive correlation between the PAS and LART (SCC 0.47; P < 0.001), CRT (SCC 0.46; P < 0.001) and GRT (SCC 0.34; P = 0.002). The AUC-ROC values for detecting a PAS ≥7 were as follows: LART, 0.83 (P < 0.0001); CRT, 0.79 (P < 0.0001); GRT, 0.72 (P < 0.0001). In this study, the LPEER showed good accuracy for evaluating LPMS. These results justify further validation studies in independent populations.

Reliability of a laryngo-pharyngeal esthesiometer and a method for measuring laryngo-pharyngeal mechano-sensitivity in a prospectively recruited cohort of patients.

BACKGROUND: There are not reliable methods for measuring laryngo-pharyngeal mechano-sensitivity (LPMS). We aimed to determine the reliability of a new method for measuring LPMS using a new laryngo-pharyngeal esthesiometer (LPEER) in a prospective cohort of dysphagic stroke and non-dysphagic patients. The patients underwent clinical and endoscopic evaluations of swallowing (FESSST). The LPMS assessments consisted of measurements by an expert and a novel rater of the laryngeal-adductor reflex threshold (LART), cough reflex threshold (CRT) and gag reflex threshold (GRT) using the LPEER. We assessed the Bland-Altman limits of agreement, the intraclass correlation coefficients (ICCs) and Spearman correlation coefficients (SCCs). For the inter-rater comparisons, we contrasted the expert and novel raters. A total of 1608 measurements were obtained from 34 dysphagic stroke patients and 33 non-dysphagic patients. The intra-rater ICCs for all reflex thresholds were >0.90. The inter-rater ICCs were 0.87 for the LART, 0.79 for the CRT and 0.70 for the GRT. The intra-rater SCCs for all reflex thresholds were above 0.88 (P < 0.0001). The inter-rater SCC were 0.80 for the LART, 0.79 for the CRT and 0.70 for the GRT (all P < 0.0001). The Bland-Altman plots revealed good agreement for the LART and CRT and moderate agreement for the GRT. The median normal value was 0.14 mN for the LART, 4.4 mN for the CRT and 11.9 mN for the GRT. The median thresholds values in patients with aspiration were LART: 1.31 mN; CRT: 32.9 mN and GRT: 32.9 mN (all P < 0.006 vs normal thresholds). The LPEER exhibited substantial to excellent intra- and inter-rater reliability.

Design, development and validation of a new laryngo-pharyngeal endoscopic esthesiometer and range-finder based on the assessment of air-pulse variability determinants.

BACKGROUND: Laryngo-pharyngeal mechano-sensitivity (LPMS) is involved in dysphagia, sleep apnea, stroke, irritable larynx syndrome and cough hypersensitivity syndrome among other disorders. These conditions are associated with a wide range of airway reflex abnormalities. However, the current device for exploring LPMS is limited because it assesses only the laryngeal adductor reflex during fiber-optic endoscopic evaluations of swallowing and requires a high degree of expertise to obtain reliable results, introducing intrinsic expert variability and subjectivity. METHODS: We designed, developed and validated a new air-pulse laryngo-pharyngeal endoscopic esthesiometer with a built-in laser range-finder (LPEER) based on the evaluation and control of air-pulse variability determinants and on intrinsic observer variability and subjectivity determinants of the distance, angle and site of stimulus impact. The LPEER was designed to be capable of delivering precise and accurate stimuli with a wide range of intensities that can explore most laryngo-pharyngeal reflexes. RESULTS: We initially explored the potential factors affecting the reliability of LPMS tests and included these factors in a multiple linear regression model. The following factors significantly affected the precision and accuracy of the test (P < 0.001): the tube conducting the air-pulses, the supply pressure of the system, the duration of the air-pulses, and the distance and angle between the end of the tube conducting the air-pulses and the site of impact. To control all of these factors, an LPEER consisting of an air-pulse generator and an endoscopic laser range-finder was designed and manufactured. We assessed the precision and accuracy of the LPEER's stimulus and range-finder according to the coefficient of variation (CV) and by looking at the differences between the measured properties and the desired values, and we performed a pilot validation on ten human subjects. The air-pulses and range-finder exhibited good precision and accuracy (CV < 0.06), with differences between the desired and measured properties at <3 % and a range-finder measurement error of <1 mm. The tests in patients demonstrated obtainable and reproducible thresholds for the laryngeal adductor, cough and gag reflexes. CONCLUSIONS: The new LPEER was capable of delivering precise and accurate stimuli for exploring laryngo-pharyngeal reflexes.

Long-term continuous positive airway pressure therapy improves cardiac autonomic tone during sleep in patients with obstructive sleep apnea.

BACKGROUND: Cardiac autonomic tone after long-term continuous positive airway pressure therapy in patients with obstructive sleep apnea remains unexplored. METHODS: Thirty patients with obstructive sleep apnea (14 with moderate and 16 with severe obstructive sleep apnea) were studied during a baseline polysomnographic study, after a full night of acute continuous positive airway pressure treatment, and after long-term (~2 years) chronic continuous positive airway pressure therapy. Twenty age- and gender-matched controls with baseline sleep study were selected for comparison purposes. Cross-spectral analysis and the low-frequency (LF) and high-frequency (HF) components of the heart rate variability were computed separately over 10-min ECG epochs during rapid eye movement sleep, non-rapid eye movement sleep, and wakefulness. RESULTS: During the baseline study, obstructive sleep apnea patients exhibited increased LF, decreased HF, and increased LF/HF ratio during sleep when compared to controls. In a multiple regression model, the mean oxygen saturation explained the increased LF during rapid and non-rapid eye movement sleep in obstructive sleep apnea patients. Acute continuous positive airway pressure therapy decreased the LF modulations and the LF/HF ratio and increased the HF modulations during sleep in patients with severe obstructive sleep apnea. Long-term continuous positive airway pressure therapy decreased LF modulations and LF/HF ratio with increased HF modulations during sleep in patients with moderate and severe obstructive sleep apnea. CONCLUSIONS: Long-term continuous positive airway pressure reduces the sympathovagal imbalance in patients with moderate and severe obstructive sleep apnea, both during rapid and non-rapid eye movement sleep. Continuous positive airway pressure seems to exert its changes in cardiac autonomic modulation by decreasing the burden of nocturnal hypoxia.

Comparative effects of gastric bypass and sleeve gastrectomy on plasma osteopontin concentrations in humans.

BACKGROUND: Bariatric surgery (BS) has proven to be an effective treatment for morbid obesity. Osteopontin (OPN) is a proinflammatory cytokine involved in the development of obesity. The aim of our study was to determine the effect of weight loss following BS on circulating levels of OPN in humans. METHODS: Body composition and circulating concentrations of OPN and markers of bone metabolism were determined in obese patients who underwent Roux-en-Y gastric bypass (RYGB; n = 40) or sleeve gastrectomy (SG; n = 11). RESULTS: Patients who underwent RYGB or SG showed decreased body weight (P < 0.001) and body fat percentage (P < 0.001) as well as lower insulin resistance. However, plasma OPN levels were significantly increased after RYGB (P < 0.001) but remained unchanged following SG (P = 0.152). Patients who underwent RYGB also showed significantly increased C-terminal telopeptide of type-I collagen (ICTP) (P < 0.01) and osteocalcin (P < 0.001) while bone mineral density tended to decrease (P = 0.086). Moreover, OPN concentrations were positively correlated with the bone resorption marker ICTP after surgery. On the other hand, patients who underwent SG showed significantly increased ICTP levels (P < 0.05), and the change in OPN was positively correlated with the change in ICTP and negatively with the change in vitamin D after surgery (P < 0.05). CONCLUSIONS: RYGB increased circulating OPN levels, while they remained unaltered after SG. The increase in OPN levels after RYGB could be related to the increased bone resorption in relation to its well-known effects on bone of this malabsorptive procedure in comparison to the merely restrictive SG.

Regulation of adipocyte lipolysis.

In adipocytes the hydrolysis of TAG to produce fatty acids and glycerol under fasting conditions or times of elevated energy demands is tightly regulated by neuroendocrine signals, resulting in the activation of lipolytic enzymes. Among the classic regulators of lipolysis, adrenergic stimulation and the insulin-mediated control of lipid mobilisation are the best known. Initially, hormone-sensitive lipase (HSL) was thought to be the rate-limiting enzyme of the first lipolytic step, while we now know that adipocyte TAG lipase is the key enzyme for lipolysis initiation. Pivotal, previously unsuspected components have also been identified at the protective interface of the lipid droplet surface and in the signalling pathways that control lipolysis. Perilipin, comparative gene identification-58 (CGI-58) and other proteins of the lipid droplet surface are currently known to be key regulators of the lipolytic machinery, protecting or exposing the TAG core of the droplet to lipases. The neuroendocrine control of lipolysis is prototypically exerted by catecholaminergic stimulation and insulin-induced suppression, both of which affect cyclic AMP levels and hence the protein kinase A-mediated phosphorylation of HSL and perilipin. Interestingly, in recent decades adipose tissue has been shown to secrete a large number of adipokines, which exert direct effects on lipolysis, while adipocytes reportedly express a wide range of receptors for signals involved in lipid mobilisation. Recently recognised mediators of lipolysis include some adipokines, structural membrane proteins, atrial natriuretic peptides, AMP-activated protein kinase and mitogen-activated protein kinase. Lipolysis needs to be reanalysed from the broader perspective of its specific physiological or pathological context since basal or stimulated lipolytic rates occur under diverse conditions and by different mechanisms.

MyotonPRO as a new valid tool for measuring cervical muscle tension. A reliability study.

OBJECTIVE: The main objective of this study is to test the reliability of a non-invasive objective method for the measurement of biomechanical parameters of cervicofacial muscle groups, with the purpose of diagnosis and evaluation of voice disorders' treatments, especially focused on muscle tension dysphonia. STUDY DESIGN: Prospective study. METHODS: The device used is a handheld myotonometer (MyotonPRO) that measures biomechanical and viscoelastic properties in superficial soft tissues frequency, stiffness, elasticity, relaxation time and creep. It is used in the field of medicine, sport and research. This pilot study includes 10 subjects, who have been measured in the masseter, sternocleidomastoid, orbicularis oris, semispinalis capitis, suprahyoid, infrahyoid and trapezius muscles on each side. Measurements were performed by 2 evaluators to assess inter-evaluator reliability. Subsequently, one of them repeated the measurements to assess intra-evaluator reliability. RESULTS: The results revealed good to excellent inter-rater reliability for the masseter, sternocleidomastoid, trapezius and suprahyoid muscles, with lower ICCs for the stiffness and creep properties. Intra-rater reliability was good to excellent for the masseter, sternocleidomastoid, semispinalis capitis and suprahyoid muscles. The lowest ICCs were found in the stiffness and creep properties. CONCLUSION: The use of a myotonometer to measure the mechanical properties of selected cervical and orofacial muscles is a reliable and reproducible method. Future research is needed to establish an association between the properties of these muscles and their role in voice disorders, as well as to determine whether this tool can aid diagnosis with quantifiable and objectifiable indicators, and for monitoring and treatment efficacy.

Relative Fundamental Frequency: Only for Hyperfunctional Voices? A Pilot Study.

(1) Background: Assessing phonatory disorders due to laryngeal biomechanical alterations requires aerodynamic analysis, assessing subglottic pressure, transglottic flow, and laryngeal resistance. This study explores whether the acoustic parameter, the relative fundamental frequency (RFF), can be studied using the current acoustic analysis protocol at the University of Navarra's voice laboratory and its association with pathologies linked to laryngeal biomechanical alterations. (2) Methods: A retrospective cohort study included patients diagnosed with muscular tension dysphonia, organic lesions of the vocal fold, and vocal fold paralysis (VFP) at the Clínica Universidad de Navarra from 2019 to 2021. Each patient underwent endoscopic laryngeal exploration, followed by acoustic study, RFF calculation, and an aerodynamic study. Additionally, a control group was recruited. (3) Results: 79 patients and 22 controls were studied. Two-way ANOVA showed significant effects for groups and cycles in offset and onset cycles. Statistically significant differences were observed in cycle 1 onset among all groups and in cycles 1 and 2 between the control group and non-healthy groups. (4) Conclusions: RFF is a valuable indicator of phonatory biomechanics, distinguishing healthy and pathological voices and different disorders. RFF in onset cycles offers a cost-effective, accurate method for assessing biomechanical disorders without complex aerodynamic analyses. This study describes RFF values in VFP for the first time, revealing differences regardless of aerodynamic patterns.

Development and validation of a low-cost laparoscopic simulation box.

INTRODUCTION: The acquisition of laparoscopic technique skills in an operating room is conditioned by the expertise of the tutor and the number of training interventions by the trainee. For students and surgeons to use a laparoscopic simulator to train their skills, it must be validated beforehand. METHODS: A laparoscopic simulator box was designed, along with 6 interchangeable training games. The simulator was validated by a group of 19 experts, physicians with an experience from at least 100 laparoscopic surgeries, and 20 students of 4th to 6th grades of medical school (non-experts). To evaluate its construct validity, time-to-completion and the number of successfully completed games were assessed. We used 11 and 9-item questionnaires to gather information on content and face validity respectively. In both questionnaires, answers were collected through Likert-type scales, scored from 1 to 5. RESULTS: The group of experts required less time and successfully completed more games than the group of non-experts (p < 0.01). The group of non-experts gave a score ≥ 4 points on each of the questions regarding the content validity of the tool, however, the experts rated with a significant lower mean score the need for the simulator to learn the surgical technique (3.68 points; p < 0.01). Regarding the face validity, all items were graded with a score ≥ 4 points except for the question relating to the spatial realism (3.82 points). CONCLUSION: The laparoscopy simulation box and the games were valid means for training surgeons and medical students to develop the skills required for the laparoscopic technique.

Multiple vocal fold lesions in a single patient.

We report the case of a 48-year-old woman, a teacher, with recurrent severe dysphonia and multiple and different lesions at the same time in her vocal folds. The evolution of the lesions and the possible mechanism by which they have been associated in the same patient are commented.

Introducing a New Dosimeter for the Assessment and Monitoring of Vocal Risk Situations and Voice Disorders.

PURPOSE: There are many physiological parameters recorded by devices that are becoming more affordable, precise and accurate. However, the lack of development in the recording of voice parameters from the physiological or medical point of view is striking, given that it is a fundamental tool for the work of many people and given the high incidence and prevalence of voice pathologies that affect people's communication. In this paper we perform a complete literature review on the dosimeters used in voice research and to present a prototype dosimeter with a pilot study to show its capabilities. METHOD: We conducted a literature review using the keywords [MONITORING], [PHONATION], [ACCUMULATOR], [PORTABLE], [DOSIMETRY], [VOICE] searching in PubMed, Trip Database, HONcode, and SciELO search engines. From our review of dosimeter designs, we created our own prototype consisting of two main components: a Knowles Electronics BU-7135-0000 accelerometer mounted on a neck brace; and the ultra-low power MSP430FR5994 microcontroller. The selected sampling frequency was 2048 Hz. The device calculates the F0 every 250 ms and the amplitude and phonation activity every 31.25 ms. A pilot study was conducted using 2 subjects: one male during 11 days and one female during 14 days. RESULTS: This work includes devices that have been created during the last 45 years as tools for the diagnosis and monitoring of the treatment of cases of vocal pathology and for the detection of phonatory patterns or risk situations for developing voice disorders or vocal pathologies. We also present recordings with our new device on the pattern of daily talk time, the fundamental frequency and the relative intensity of two subjects on different days. CONCLUSIONS: Interesting work has been done in the development of voice dosimeters with different approaches. In our experience it is not possible to access them for research and they are not yet in clinical use. It is possible that a joint approach with voice and voice disorders professionals and engineers working closely together could take advantage of current technology to develop a fully portable, useful, and efficient system.

The Irrintzi and Other Folk Cries High Pich and Loud Emission. Can We Learn Something?

INTRODUCTION: In various cultures there are vocal sounds and cries associated with the folk tradition. All these cries are emitted in a single breath, have a high frequency and are loud. They are consequently audible over long distances and cut through other vocal expressions or other sounds generated by instruments. OBJECTIVES: The objective of this work is to acoustically analyze some of these folkloric cries and study elements common to all of them. METHODS: In this study, Irrintzi, Aturuxo, Tzagrit, ululation Darfur and Kurava cries were subjected to descriptive acoustic spectrographic analysis, and the resulting descriptions were compared both quantitatively, in terms of various acoustic parameters, and qualitatively, in terms of spectrographic characteristics and the way the cries sound. RESULTS: All of the cries contained high frequencies. Spectrograms of the cries revealed that they had a common pattern: a lower initial frequency ascends rapidly (the attack) and is then maintained throughout a stable phase of the emission (the body) before a final drop in frequency (the ending or coda). The body is the longest phase. CONCLUSIONS: This initial study of five sounds of folk tradition has opened up a wealth of acoustic and cultural discoveries. Broader studies are now needed to determine if the characteristics we have reported are common to other cries, to look for other similarities, and to delve into meanings, implications and possible applications. In-depth understanding of the mechanism of emission of traditional cries could provide tools for voice re-education in patients with dysphonia due to vocal strain (muscle tension dysphonia, vocal nodules, etc.), for improving voice quality, and for increasing the efficiency of vocal performance.

Describing the Acoustic and Vocal Production Characteristics of the Irrintzi: Feasibility of Its Use for the Treatment of Voice Disorders.

PURPOSE: The aims of this study were to analyze and characterize the irrintzi (a folkloric shout emitted in a single breath used by the Basque people) acoustically and to describe the mechanism by which it is emitted. METHOD: Thirty-six sound samples of 12 female volunteers were analyzed. Acoustic analysis included primarily fundamental frequency (f o), spectral analysis in the time domain with a narrowband filter, and the use of linear predictive coding (LPC). Laryngeal and pharyngeal movements while emitting an irrintzi were studied by fiberoptic nasal endoscopy. Postural and mandible movements were observed and video recorded. Movements of the larynx and the vocal tract were also studied by lateral pharyngo-laryngeal radioscopy. RESULTS: The central part of an irrintzi spectrogram contains a peculiar, repeated M-shaped motif unseen in the spectrogram of any other human vocal emission, and intensity was over 90 dB SPL in all cases. f o was very high (1487 Hz) especially at the end of the irrintzi. Fiberoptic nasal endoscopy consistently revealed considerable elevation of the glottis, with the larynx swinging forward and retraction of the ventricular bands. Lateral radioscopy showed a very high larynx and a high tongue dorsum. CONCLUSIONS: The irrintzi is a sound emitted in a single breath and characterized by its shrillness and loudness, qualities that make it audible in noisy environments and over large distances and the vocal technique observed when it is produced can be explained by the Estill voice model (Steinhauer et al., 2017). The use of this technique may help in the treatment of voice disorders and improve efficiency in singers, teachers, actors, and people who use their voice at high volume or at high frequency. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.20779405.

Development and validation of a low-cost laparoscopic simulation box.

INTRODUCTION: The acquisition of laparoscopic technique skills in an operating room is conditioned by the expertise of the tutor and the number of training interventions by the trainee. For students and surgeons to use a laparoscopic simulator to train their skills, it must be validated beforehand. METHODS: A laparoscopic simulator box was designed, along with 6 interchangeable training games. The simulator was validated by a group of 19 experts, physicians with an experience from at least 100 laparoscopic surgeries, and 20 students of 4th to 6th grades of medical school (non-experts). To evaluate its construct validity, time-to-completion and the number of successfully completed games were assessed. We used 11 and 9-item questionnaires to gather information on content and face validity respectively. In both questionnaires, answers were collected through Likert-type scales, scored from 1 to 5. RESULTS: The group of experts required less time and successfully completed more games than the group of non-experts (p < 0.01). The group of non-experts gave a score ≥4 points on each of the questions regarding the content validity of the tool, however, the experts rated with a significant lower mean score the need for the simulator to learn the surgical technique (3.68 points; p < 0.01). Regarding the face validity, all items were graded with a score ≥4 points except for the question relating to the spatial realism (3.82 points). CONCLUSION: The laparoscopy simulation box and the games were valid means for training surgeons and medical students to develop the skills required for the laparoscopic technique.

Simple and Autonomous Sleep Signal Processing System for the Detection of Obstructive Sleep Apneas.

Obstructive sleep apnea (OSA) is a common sleep disorder characterized by repetitive upper airway obstruction, intermittent hypoxemia, and recurrent awakenings during sleep. The most used treatment for this syndrome is a device that generates a positive airway pressure­Continuous Positive Airway Pressure (CPAP), but it works continuously, whether or not there is apnea. An alternative consists on systems that detect apnea episodes and produce a stimulus that eliminates them. Article focuses on the development of a simple and autonomous processing system for the detection of obstructive sleep apneas, using polysomnography (PSG) signals: electroencephalography (EEG), electromyography (EMG), respiratory effort (RE), respiratory flow (RF), and oxygen saturation (SO2). The system is evaluated using, as a gold standard, 20 PSG tests labeled by sleep experts and it performs two analyses. A first analysis detects awake/sleep stages and is based on the accumulated amplitude in a channel-dependent frequency range, according to the criteria of the American Academy of Sleep Medicine (AASM). The second analysis detects hypopneas and apneas, based on analysis of the breathing cycle and oxygen saturation. The results show a good estimation of sleep events, where for 75% of the cases of patients analyzed it is possible to determine the awake/asleep states with an effectiveness of >92% and apneas and hypopneas with an effectiveness of >55%, through a simple processing system that could be implemented in an electronic device to be used in possible OSA treatments.

Sound analysis of catathrenia: a vocal expiratory sound.

PURPOSE: Catathrenia (nocturnal groaning) is a rare and relatively little-understood parasomnia. The characteristics of the sound and the recordings are not similar in all the relevant research papers. Indeed, there is currently some discussion regarding whether or not this is a single entity. For some authors, catathrenia is a particular form of parasomnia; for others, it may be a variant of snoring or a respiratory problem. The goal is to establish whether or not catathrenia may be regarded as an expiratory vocal sound. An attempt was made to classify the origin of this sound according to its sound structure. METHODS: We present the sound analysis of two patients, a man and a woman, with clinically diagnosed catathrenia and we compared them with the analysis of snoring. We use the spectrogram and the oscillogram. We classified the sounds according to the Yanagihara criteria. RESULTS: The vocal nature of the sound was confirmed, and several significant differences to some snoring sounds were discovered. The analysis of the catathrenia samples demonstrated that these signals are type II according to Yanagihara classification; these signals had a very short jitter, and had formants and harmonics. However, snoring is a type III, very irregular and had formants but not harmonics. CONCLUSIONS: The oscillogram and the spectrogram in these patients show that the origins of the sounds are clearly different: catathrenia is laryngeal, while snoring is guttural. Catathrenia cannot be considered as expiratory snoring.

Design and Development of an Automated Feedback and Scoring System for Self-directed Learning of Flexible Nasal Endoscopy With an Airway Simulator.

INTRODUCTION: The AirSim Multi (TruCorp) airway simulator is used to practice exploration of the upper respiratory tract with a flexible endoscope to assess the nasal cavities, their structures and spaces (inferior, middle, and superior turbinates and meati), and the nasopharynx. The passage of the flexible endoscope through the nose is usually the most annoying and painful maneuver to continue the exploration of the airway to the pharynx and larynx. For this reason, it is important to develop self-assessment training systems in safe environments that allow trainees to develop the necessary skills to carry out this type of assessment with the least inconvenience and the greatest security. Despite this simulator's accurate anatomical reproduction of the tract, its suitability as a tool for endoscope exploration learning is limited without a feedback system. Effective endoscopic exploration should not cause pain or lesions, not only for comfort and safety reasons, but also because only when discomfort is minimized is a complete and detailed exploration of the anatomical structures possible.The objective of the project was to provide a feedback system from the simulator to the trainee that would facilitate improvements in self-trained skills needed to perform an endoscopic exploration of the airways. METHODS: A device based on the Hall-effect sensor was designed and placed outside the airway in the upper nasal turbinate. This device detects changes in the magnetic flux, indicating a displacement on the nasal turbinate due to endoscopic maneuvers that deform the inside of the simulator and would be expected to be harmful or painful in real life. RESULTS: The improved AirSim provides audible and visual feedback during exploration to indicate a change on the nasal turbinate due to endoscopic contact with the turbinate surface that would be expected to be harmful or painful in real life. We expect this feature to facilitate self-learning with minimal professional supervision and reduce the overall training time required to successfully perform a complete exploration of the airway. CONCLUSIONS: The inclusion of sensors on a passive simulator is a cost-effective measure that may allow for better training experiences using AirSim Multi simulator from the TruCorp company. Our improved simulator turns endoscopic exploration into a self-assessed exercise suitable for all disciplines and level of learners.

Validation of a Sensor-Fitted Simulator for Upper Airway Examination.

OBJECTIVE: To validate a simulator for upper airway examination, fitted with sensors, for use as an academic tool for learning how to conduct examination of the upper airway and for evaluation of that learning. STUDY DESIGN: Validation study. SETTING: Undergraduate medical education. SUBJECTS AND METHODS: A group of 18 fifth-year medical students and another of 6 otorhinolaryngology specialists conducted 6 examinations each with the simulator. To investigate concurrent validity, we calculated the correlation between damage scores provided by the simulator and damage assessment by a specialist. To evaluate construct validity, we compared both groups with regard to damage scores, technical procedure, and time spent. To examine content and face validity, we used questionnaires based on a 5-point Likert scale. RESULTS: For concurrent validity, the correlation between the simulator's damage scores and the specialist's damage assessment was high: Spearman's ρ was 0.828 (P < .001). For construct validity, the group of students differed from the group of specialists in damage scores (P = .027) and in technical procedures (P < .001) but not in time spent. For content validity, all questionnaire statements were scored highly, and both groups had similar average scores. For face validity, the group of specialists considered the simulator to be realistic, and all statements on the questionnaire were rated with at least 4/5. CONCLUSION: Concurrent, construct, content, and face validity have been demonstrated for a sensor-fitted simulator for upper airway examination, which is therefore accurate enough to be used as an academic tool for learning and evaluation of learning.