On-board diagnostics (OBD) – Analysis of the OBD with regard to emission data available in future for the Periodic Technical Inspection (PTI)

Im Rahmen dieser Studie wurde zuerst der IST-Zustand zur OBD-Gesetzeslage detailliert dargestellt. Eine folgende umfangreiche Befragung der Prüforganisationen sowie des KBA zu emissionsrelevanten OBD-Themen erfolgte unter Zuhilfenahme des ÖAMTC-Abfrageportals. Die Befragung ergab unter anderem, dass ein erweiterter Bedarf an OBD-Informationen zur Beurteilung emissionsrelevanter Systeme für die PTI vorwiegend bei NOx-Sensoren, Differenzdruckdaten des Partikelfilters, der Abgastemperatur, den Informationen zu Reagenzmitteln und Abgasrückführung erforderlich sind. Im Weiteren wurde exemplarisch an drei Fahrzeugen untersucht, welche Daten aktuell über die OBD-Schnittstelle ausgelesen werden können, und ob bei emissionsrelevanten Bauteilen Diagnosejobs, wie zum Beispiel Aktuatorenansteuerung aktiv eingeleitet werden können. Die Untersuchung ergab ein sehr unterschiedliches Bild über die verfügbaren Daten und Möglichkeiten. Anschließend wurden im Rahmen dieser Arbeit diverse Sensoren, wie z.B. NOx-Sensoren, NH3-Sensoren und PM-/PN-Sensoren, hinsichtlich ihrer Eignung für OBD- und PTI-Aufgaben analysiert. Die Sensoranalyse erfolgte anhand von Datenblättern sowie Befragung der Sensorhersteller. Der NOx-Sensor wurde in der Bewertung als tauglichster Sensor für eine weiterführende Untersuchung ermittelt und kommt zudem bereits seit einigen Jahren serienmäßig in Diesel-Fahrzeugen zum Einsatz. Daher eignet sich dieser Sensor gut, um zukünftig die NOx-Emissionen im realen Betrieb zu überwachen und wurde deshalb auch für die detaillierte messtechnische Untersuchung ausgewählt. Die detaillierte messtechnische Untersuchung wurde mit einem modernen Diesel-Pkw der Abgasnorm Euro 6d durchgeführt. Mit dem Versuchsfahrzeug wurden Messungen am Pkw-Rollenprüfstand sowie auf der Straße durchgeführt. Auch Fahrten mit speziell erzeugten fehlerhaften Abgasnachbehandlungssystemen sind aufgezeichnet worden. Insgesamt wurden etwa 4.500 Fahrzeugkilometer an Messdaten mit verschiedenen Fahrsituationen gesammelt, welche mit einem Datenlogger aufgezeichnet und folgend für die Methodenentwicklung herangezogen wurden. Bei der Entwicklung der Methode für eine zukünftige NOx-Überwachung im realen Fahrzeugbetrieb wurde darauf Rücksicht genommen, dass höhere NOx-Emissionen in bestimmten Fahrsituationen, welche für das Abgasnachbehandlungssystem herausfordernd sind, nicht als Fehler identifiziert werden, sofern das Abgasnachbehandlungssystem ordnungsgemäß arbeitet. Die erarbeitete Methode beurteilt die Funktionalität der NOx-Abgasnachbehandlungssysteme durch das Verhältnis gNOx/kgKraftstoff. Die NOx-Sensor- und Kraftstoffverbrauchssignale konnten beim Versuchsfahrzeug über die OBD-Schnittstelle abgerufen werden. Es wird davon ausgegangen, dass auch in modernen Pkw anderer Hersteller diese Signale verfügbar sind. Liegt das ermittelte Verhältnis über einem Schwellenwert, so liegt mit hoher Wahrscheinlichkeit ein Fehler des NOx-Abgasnachbehandlungssystems vor, liegt das Verhältnis unter dem Schwellenwert, so kann davon ausgegangen werden, dass kein Fehler vorliegt. Das gNOx/kgKraftstoff-Verhältnis könnte bei einem errechneten Wert oberhalb des Schwellenwertes zu einer anlassbezogenen PTI führen oder als Fehler mit der MIL im Display angezeigt werden oder im Zuge der regulären PTI ausgelesen werden. Derzeit wird im Rahmen der Arbeiten zu Euro 7 diskutiert, ob Fahrzeuge bei der geplanten Euro 7 Gesetzgebung NOx-Grenzwerte betriebswarm unter jeglichen Fahrsituationen einhalten müssen. Gegebenenfalls könnte dann eine Überwachung im realen Betrieb auch über g/km erfolgen. Die Anwendung der erarbeiteten Methode mit gNOx/kgKraftstoff wäre aber weiterhin möglich. Es wird daher empfohlen, nach Fixierung der relevanten Details der Euro 7 Gesetzgebung die vorgeschlagene Methode mit gNOx/kgKraftstoff zu validieren und zu optimieren.Within this study, the current state of OBD legislation was first investigated in detail. A subsequent comprehensive survey of the experience of testing organizations and the KBA on emission-relevant OBD topics was conducted using the ÖAMTC query portal. The survey revealed that an extended need for OBD information for the assessment of emission-relevant systems for the PTI is required for NOx sensors, for differential pressure data of the particulate filter, for exhaust gas temperature, for information on reagents and for exhaust gas recirculation. In addition, three vehicles were used as examples to investigate which data can currently be read out via the OBD interface and whether diagnostic jobs, such as actuator control, can be actively initiated for emission-relevant components. The investigation showed a very varied picture of the available data and possibilities. Subsequently, different sensors, such as NOx sensors, NH3 sensors and PM/PN sensors, were analysed within the scope of this work with regard to their suitability for OBD and PTI tasks. The sensor analysis was based on data sheets and interviews with sensor manufacturers. The NOx sensor was identified in the evaluation as the most suitable sensor for further investigation and has also been used as standard in diesel vehicles for several years. This sensor is therefore well suited to monitoring NOx emissions in real operation in the future and was therefore also selected for the detailed investigation. The detailed investigation was carried out with a modern Euro 6d diesel passenger car. Tests were performed on the chassis dynamometer as well as on the road. Tests with specially generated faulty exhaust aftertreatment systems have also been recorded. A total of around 4,500 vehicle kilometres of measurement data were collected with various driving situations, which were recorded with a data logger and subsequently used for method development. In developing the method for future NOx monitoring in real vehicle operation, consideration was given to the fact that higher NOx emissions in certain driving situations, which are challenging for the exhaust aftertreatment system, are not identified as a fault, provided that the exhaust aftertreatment system is working properly. The developed method assesses the functionality of NOx exhaust aftertreatment systems by the ratio gNOx/kgFuel. The NOx sensor and fuel consumption signals could be retrieved from the OBD interface on the test vehicle. It is assumed that these signals are also available in modern passenger cars from other manufacturers. If the determined ratio is above a threshold value, there is a high probability that there is a fault in the NOx exhaust aftertreatment system. If the ratio is below the threshold value, it can be assumed that there is no fault. The gNOx/kgFuel ratio, if calculated above the threshold, could lead to an occasion-based PTI or be indicated as a fault with the MIL in the driver information display or be read out during the regular PTI. As part of the work on Euro 7, it is currently being discussed whether vehicles will have to comply with NOx limits at operating points under almost any driving situations in the planned Euro 7 legislation. Monitoring in real operation could then also be carried out via g/km as alternative. However, the application of the developed method with gNOx/kgFuel would still be possible. It is therefore recommended to validate and optimize the most suitable method with gNOx/kgFuel after the boundary condition of the Euro 7 RDE test conditions are defined

High-Density Lipoprotein Function in Exudative Age-Related Macular Degeneration.

PURPOSE:High-density lipoproteins (HDL) have long been implicated in the pathogenesis of age-related macular degeneration (AMD). However, conflicting results have been reported with regard to the associations of AMD with HDL-cholesterol levels. The present study is the first to assess HDL composition and metrics of HDL function in patients with exudative AMD and control patients. METHODS:Blood samples were collected from 29 patients with exudative AMD and 26 age-matched control patients. Major HDL associated apolipoproteins were determined in apoB-depleted serum by immunoturbidimetry or ELISA, HDL-associated lipids were quantified enzymatically. To get an integrated measure of HDL quantity and quality, we assessed several metrics of HDL function, including cholesterol efflux capacity, anti-oxidative and anti-inflammatory activities using apoB-depleted serum from study participants. RESULTS:In our study, we observed that the HDL associated acute phase protein serum amyloid A (SAA) was significantly increased in AMD patients (p<0.01), whereas all other assessed apolipoproteins including ApoA-I, apoA-II, apoC-II, apoC-III and apoE as well as major HDL associated lipids were not altered. HDL efflux capacity, anti-oxidative capacity and arylesterase activity were not different in AMD patients when compared with the control group. The ability of apoB-depleted serum to inhibit monocyte NF-κB expression was significantly improved in AMD patients (mean difference (MD) -5.6, p<0.01). Moreover, lipoprotein-associated phospholipase A2 activity, a marker of vascular inflammation, was decreased in AMD subjects (MD -24.1, p<0.01). CONCLUSIONS:The investigated metrics of HDL composition and HDL function were not associated with exudative AMD in this study, despite an increased content of HDL associated SAA in AMD patients. Unexpectedly, anti-inflammatory activity of apoB-depleted serum was even increased in our study. Our data suggest that the investigated parameters of serum HDL function showed no significant association with exudative AMD. However, we cannot exclude that alterations in locally produced HDL may be part of the AMD pathogenesis

A Systematic Review and Meta-Analysis on the Safety of Vascular Endothelial Growth Factor (VEGF) Inhibitors for the Treatment of Retinopathy of Prematurity

<div><p>Introduction</p><p>Laser photocoagulation is the current gold standard treatment for proliferative retinopathy of prematurity (ROP). However, it permanently reduces the visual field and might induce myopia. Vascular endothelial growth factor (VEGF) inhibitors for the treatment of ROP may enable continuing vascularization of the retina, potentially allowing the preservation of the visual field. However, for their use in infants concern remains. This meta-analysis explores the safety of VEGF inhibitors.</p><p>Methods</p><p>The Ovid Interface was used to perform a systematic review of the literature in the databases PubMed, EMBASE and the Cochrane Library.</p><p>Results</p><p>This meta-analysis included 24 original reports (including 1.457 eyes) on VEGF inhibitor treatment for ROP. The trials were solely observational except for one randomized and two case-control studies. We estimated a 6-month risk of retreatment per eye of 2.8%, and a 6-month risk of ocular complication without the need of retreatment of 1.6% per eye. Systemic complications were only reported as isolated incidents.</p><p>Discussion</p><p>VEGF inhibitors seem to be associated with low recurrence rates and ocular complication rates. They may have the benefit of potentially allowing the preservation of visual field and lower rates of myopia. Due to the lack of data, the risk of systemic side effects cannot be assessed.</p></div

Cholesterol efflux capacity.

<p>Apolipoprotein B (apoB)-depleted sera of healthy subjects (control, n = 27) and patients with age-related macular degeneration (AMD, n = 29) were examined for (A) their ability to promote [³H]-cholesterol efflux from macrophages. [³H]-cholesterol-labeled RAW264.7 macrophages were incubated with 2.8% apoB-depleted sera for 4 hours. Cholesterol efflux is expressed as radioactivity in the supernatant relative to total radioactivity (in supernatant and cells). Values shown represent means of two independent experiments.</p

Characteristics of included studies.

<p>Studies are sorted by date of publication.</p><p>*Not all patients included for quantitative analysis, as only selected patient groups fitted our criteria (no combined treatment, no recurrences).</p><p>**The follow-up period is only reported if follow-up was a defined period of time.</p><p>Characteristics of included studies.</p

Systemic VEGF suppression after VEGF inhibitors.

<p>Research papers investigating systemic levels of VEGF after intravitreal injection of VEGF inhibitors over a defined period of time. *1 = infants with retinopathy of prematurity, unilateral injection of bevacizumab (14); 2 = infants with retinopathy of prematurity, unilateral injection of ranibizumab (105); 3 = patients with age-related macular degeneration (AMD), unilateral injection of bevacizumab (106); 4 = patients with AMD, bilateral injection of bevacizumab (106); 5 = patients with AMD, unilateral injection of ranibizumab (107); 6 = patients with AMD, unilateral injection of bevacizumab (108); 7 = patients with AMD, unilateral injection of ranibizumab (108); 8 = patients with AMD, unilateral injection of aflibercept (109); 9 = patients with AMD, unilateral injection of ranibizumab (109); 10 = patients with AMD, unilateral injection of ranibizumab (110); 11 = patients with AMD, unilateral injection of aflibercept (110); 12 = patients with AMD, unilateral injection of ranibizumab (111). ** y-axis in pg/ml.</p

Characteristics of included studies for refractive error.

<p>Studies are sorted by date of publication.</p><p>*The follow-up period is only reported if follow-up was a defined period of time.</p><p>Characteristics of included studies for refractive error.</p