44 research outputs found
Extreme sensitivity of hearing to decreases of ICP in Menière's disease
We report the case of a Menière's disease patient affected by normal pressure hydrocephalus (NPH) who presented a cerebrospinal fluid (CSF) pressure-dependent hearing impairment after shunting. This side-effect was not only reversible and reproducible but occurred at a high opening pressure when the valve setting was lowered by only 0.7mmHg (10mmH2O). This observation suggests that hearing in Menière's disease might be very sensitive to small reductions of intracranial pressure (ICP) and that these patients should be informed of this potential risk, which can compromise the efficacy of the shun
Optically addressable single-use microfluidic valves by laser printer lithography
We report the design, fabrication, and characterization of practical optofluidic valves fabricated using laser printer lithography. Valves are opened by directing optical energy from a solid-state laser, with similar power characterisitcs to those used in CD/DVD drives, to a spot of printed toner where localized heating melts an orifice in the polymer layer in as little as 500 ms, connecting previously isolated fluidic components or compartments. Valve functionality, response time, and laser input energy dependence of orifice size are reported for cyclo-olefin copolymer (COC) and polyethylene terephthalate (PET) films. Implementation of these optofluidic valves is demonstrated on pressure-driven and centrifugal microfluidic platforms. In addition, these “one-shot” valves comprise a continuous polymer film that hermetically isolates on-chip fluid volumes within fluidic devices using low-vapor-permeability materials; we confirmed this for a period of one month. The fabrication and integration of optofluidic valves is compatible with a range of polymer microfabrication technologies and should facilitate the development of fully integrated, reconfigurable, and automated lab-on-a-chip systems, particularly when reagents must be stored on chip for extended periods, e.g. for medical diagnostic devices, lab-on-a-chip synthetic systems, or hazardous biochemical analysis platforms
Miniaturization of a micro-optics array for highly sensitive and parallel detection on an injection moulded lab-on-a-chip
Lumbar discectomy with annulus fibrosus closure: a retrospective series of 53 consecutive patients.
Lumbar disc herniation is most common degenerative alteration of the spine. Whenever surgical therapy proves to be necessary, recurrent disc herniation is most frequent concern. Here, primary aim was to determine the percentage of patients eligible for insertion of an annular closure device (ACD). Secondary aim to evaluate 12-month incidence of recurrent disc herniation at the operated level. Our hypothesis was that ACD might help in preventing recurrent disc herniation.
Patients in a single XXX neurosurgical center underwent limited discectomy alone (n=41, group 1) versus limited discectomy plus ACD (n=12, group 2). Mean postoperative follow-up period was 12 months.
Twelve out of 53 patients (22.6 %) were eligible for ACD implantation. Patients of group 2 were significantly taller (mean 176 cm, p= 0.007) as compared with group 1 (mean 170). The only statistically significant difference of intraoperative parameters between group 1 and 2 was amount of nucleus materiel removed (p= 0.01), being greater in group 2 (mean 0.9) as compared with group 1 (mean 0.3). In group 1 six patients (6/41, 14.6%) presented with symptomatic reherniation at same level of surgery, while in group 2 only one patient experienced recurrence (1/12, 8.3%). No adverse events were reported.
In the current study one out of five patients with lumbar disc herniation was considered suitable for ACD placement. In vast majority of these patients reherniation was precluded on the short-term basis. Patients with ACD were taller and had intraoperatively a higher volume of the nucleus pulposus materiel removed
Time course of error detection and correction in humans: neurophysiological evidence.
Using event-related brain potentials, the time course of error detection and correction was studied in healthy human subjects. A feedforward model of error correction was used to predict the timing properties of the error and corrective movements. Analysis of the multichannel recordings focused on (1) the error-related negativity (ERN) seen immediately after errors in response- and stimulus-locked averages and (2) on the lateralized readiness potential (LRP) reflecting motor preparation. Comparison of the onset and time course of the ERN and LRP components showed that the signs of corrective activity preceded the ERN. Thus, error correction was implemented before or at least in parallel with the appearance of the ERN component. Also, the amplitude of the ERN component was increased for errors, followed by fast corrective movements. The results are compatible with recent views considering the ERN component as the output of an evaluative system engaged in monitoring motor conflict
Retrospective analysis within the framework of quality assurance
Frakturen des distalen Humerus sind eine häufige Verletzung im Kindes- und Jugendalter. Für eine optimale Behandlung sollten individuelle Besonderheiten, wie das Alter mit dem einhergehenden Korrekturpotential sowie die richtige Klassifizierung der Fraktur, Berücksichtigung finden. Standards der klinischen Befunderhebung, der diagnostischen und therapeutischen Verfahren und Verlaufskontrollen sind zum Erhalt sowie Ausbau der Behandlungsqualität unerlässlich. Ziel der retrospektiven klinischen Qualitätssicherungsstudie ist die Analyse und Identifizierung wesentlicher epidemiologischer und ätiologischer Daten sowie der Diagnose- und Therapieverfahren von supra-, epi- und transkondylären Humerusfrakturen im Kindes- und Jugendalter an der Universitätsmedizin Göttingen. Untersucht wurden 284 Fälle mit distalen Humerusfrakturen an der Klinik für Unfallchirurgie, Orthopädie und Plastische Chirurgie in dem Zeitraum von 2005 bis 2015. Zunächst wurden epidemiologische Daten wie die Alters- und Geschlechtsverteilung, die Frakturlokalisation, die jahreszeitliche Verteilung sowie der Unfallort und Unfallhergang verglichen. Die Zeitintervalle bezüglich der Erstvorstellung, dem Therapiebeginn, der Behandlungs- und ggf. stationären Aufenthalts- sowie Immobilisationsdauer bis hin zur möglichen Osteosynthesematerialentfernung fanden Berücksichtigung. Anschließend wurden die einzelnen Frakturtypen betrachtet und die Ergebnisse zur Epidemiologie und Ätiologie, Anamnese, Diagnostik, Therapieverfahren, Komplikationen und Nachbehandlung in Bezug zur Literatur evaluiert. Insgesamt zeigte sich bei der Auswertung eine weitestgehende Kongruenz bezüglich der epidemiologischen Daten, dem Vorgehen bei konservativer oder operativer Behandlung und der Prävalenz der Komplikationen an der Universitätsmedizin Göttingen. Die ausführliche Aufschlüsselung der Basisdaten eröffnet zudem die Möglichkeit weiterführende Studien und Präventionsstrategien zu implementieren.Fractures of the distal humerus are common injuries in childhood and adolescence. For optimal treatment individual characteristics such as age the associated correction potential and the correct fracture classification should be considered. Standards regarding diagnostic and therapeutic methods as well as follow-up checks are equally important. This retrospective clinical quality assurance study analyzes epidemiological and etiological data as well as diagnostic and therapeutic procedures of supra-, epi- and transcondylar humerus fractures in childhood and adolescence at the University of Göttingen. The study examined 284 cases with distal humerus fractures at the Department of Trauma Surgery, Orthopedics and Plastic Surgery in the period from 2005 to 2015. First, epidemiological data such as age and gender distribution, fracture location, seasonal variation, accident location and accident occurrence were compared. Time intervals regarding the initial presentation, therapy initiation, treatment duration, if necessary the inpatient stay length, immobilization time and if applicable the time up to the removal of osteosynthesis material were studied. The individual fracture types were then examined and the results on epidemiology and etiology, anamnesis, diagnostics, therapeutic procedures, complications and follow-up were compared to the literature. Overall the evaluation was mostly congruent regarding the epidemiological data, the approach to conservative or surgical treatment and the prevalence of complications at the University of Göttingen. The detailed data analysis also opens up the possibility of implementing further studies and prevention strategies.2021-07-2