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  • 1
    German Medical Science GMS Publishing House; Düsseldorf
    In:  GMS German Medical Science; VOL: 17; DOC02 /20190222/
    Publication Date: 2019-02-22
    Description: The current gold standard for assessment of most sleep disorders is the in-laboratory polysomnography (PSG). This approach produces high costs and inconveniences for the patients. An accessible and simple preliminary screening method to diagnose the most common sleep disorders and to decide whether a PSG is necessary or not is therefore desirable. A minimalistic type-4 monitoring system which utilized tracheal body sound and actigraphy to accurately diagnose the obstructive sleep apnea syndrome was previously developed. To further improve the diagnostic ability of said system, this study aims to examine if it is possible to perform automated sleep staging utilizing body sound to extract cardiorespiratory features and actigraphy to extract movement features.A linear discriminant classifier based on those features was used for automated sleep staging using the type-4 sleep monitor. For validation 53 subjects underwent a full-night screening at Ulm University Hospital using the developed sleep monitor in addition to polysomnography. To assess sleep stages from PSG, a trained technician manually evaluated EEG, EOG, and EMG recordings. The classifier reached 86.9% accuracy and a Kappa of 0.69 for sleep/wake classification, 76.3% accuracy and a Kappa of 0.42 for Wake/REM/NREM classification, and 56.5% accuracy and a Kappa of 0.36 for Wake/REM/light sleep/deep sleep classification. For the calculation of sleep efficiency (SE), a coefficient of determination r2 of 0.78 is reached. Additionally, subjects were classified into groups of SEs (SE〉=40%, SE〉=60% and SE〉=80%). A Cohen's Kappa 〉0.61 was reached for all groups, which is considered as substantial agreement.The presented method provides satisfactory performance in sleep/wake and wake/REM/NREM sleep staging while maintaining a simple setup and offering high comfort. This minimalistic approach may address the need for a simple yet reliable preliminary sleep screening in an ambulatory setting.
    Description: Der aktuelle Goldstandard für die Beurteilung der meisten Schlafstörungen ist die Polysomnographie (PSG). Diese Methode der Diagnose ist mit hohen Kosten und Unannehmlichkeiten für die Patienten verbunden. Eine einfache Methode der Diagnose der häufigsten Schlafstörungen ist daher wünschenswert. Hierzu wurde ein minimalistischer Typ-4-Schlafmonitor, welcher Körperschall und Aktigraphie zur Diagnose des obstruktiven Schlafapnoe-Syndroms einsetzt, entwickelt. Um die Diagnosefähigkeit dieses Systems zu erweitern, soll in dieser Studie untersucht werden, ob der Schlafmonitor automatisiert Schlafstadien klassifizieren kann. Hierbei wird Körperschall verwendet, um kardiorespiratorische Merkmale zu extrahieren, und Aktigraphie, um Bewegungsmerkmale zu extrahieren.Ein auf diesen Merkmalen basierender linearer Diskriminanzklassifizierer wurde für die automatisierte Klassifizierung von Schlafstadien mit dem vorgestellten Typ-4-Schlafmonitor verwendet. Zur Validierung wurden 53 Probanden am Universitätsklinikum Ulm zusätzlich zur PSG einem nächtlichen Screening mit dem entwickelten Schlafmonitor unterzogen. Zur Beurteilung der Schlafstadien der PSG hat ein geschulter Techniker EEG-, EOG- und EMG-Aufnahmen manuell ausgewertet. Der Klassifikator erreichte eine Genauigkeit von 86,9% und ein Kappa von 0,69 für Schlaf/Wach-Klassifizierung, 76,3% Genauigkeit und ein Kappa von 0,42 für Wach/REM/NREM-Klassifizierung, und 56,5% Genauigkeit und ein Kappa von 0,36 für Wach/REM/Leichtschlaf/Tiefschlaf-Klassifizierung. Für die Berechnung der Schlafeffizienz (SE) wird ein Bestimmtheitsmaß r2 von 0,78 erreicht. Zusätzlich wurden die Probanden in Gruppen von SEs eingeteilt (SE〉=40%, SE〉=60% und SE〉=80%). Ein Cohen's Kappa 〉0,61 wurde für alle Gruppen erreicht, was als substantielle Übereinstimmung angesehen wird.Die vorgestellte Methode bietet eine zufriedenstellende Leistung in der Schlaf/Wach- und Wach/REM/NREM-Schlaf-Klassifizierung bei einfachem Aufbau und hohem Patientenkomfort. Dieser minimalistische Ansatz kann den Bedarf an einem einfachen aber zuverlässigen Vorab-Schlaf-Screening im ambulanten Bereich abdecken.
    Keywords: sleep staging ; monitoring ; respiratory sounds ; movement analysis ; ddc: 610
    Language: English
    Type: article
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  • 2
    ISSN: 1432-2218
    Keywords: Key words: Laparoscopy — Instruments — Handle — Ergonomics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Background: Various handles are available for use in minimally invasive surgery. Nonergonomic positioning of the hand and fingers can lead to pressure areas, nerve irritation, and rapid fatigue. This study was designed to compare the ergonomic efficiency of several different handles, along with the concepts underlying them, in an attempt to find the best one for laparoscopic surgery. We also consider whether the position of the surgeon in relation to the patient and the posture of the surgeon have any influence on the use of the handles. Method: A ring handle positioned in-line (the Microsurge/Vygon 01-1007), an axial handle (the Aesculap PM-953), a shank handle (the Wilo 25.00), and a functional model of a new ergonomic multifunctional handle (the MFEHG Schafreuter) were tested and evaluated by 15 volunteers during an objective test using a transparent pelvitrainer with the left and right hand in a frontal and left and right lateral positions. Our analysis was based on their subjective answers to a questionnaire developed from ergonomic checklists and the semiquantitative observations of the test leader about their posture during testing. Results: There were no significant differences in the results of the objective tests. Subjectively, the shank handle was preferred by most test persons, followed by the functional model for the right hand and the axial handle for the left hand; the ring handle positioned in-line scored poorly for both right and left hands. Arm movements were greater in the latter than in the frontal position. Conclusions: A clear recommendation for any one of the three currently available handles cannot be given. The results obtained with a simple model of a multifunctional handle were highly promising, and it may be possible to extend it to a real multifunctional instrument.
    Type of Medium: Electronic Resource
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