RUNNING IN LOWER LIMB AMPUTEES: ADVANTAGES AND LIMITATIONS OF NEW SPORTS PROSTHETIC COMPONENTS

Until some years ago, running in lower limb amputees was basically restricted by the inadequate dimensions of available prosthetic components that usually did not allow for the adequate dynamics necessary for running at lower speeds. Newly developed prosthetic components for recreational sports have enabled a great number of lower limb amputees to participate in running as an endurance sport. The present paper compares biomechanical parameters representing the functional benefits that result from the use of these components. The results were used to define potential advantages and limitations of lower limb amputee running depending on the level of amputation. Running of TF amputees is characterised by specific constraints based on the absence of knee stabilising muscles and the technical features of prosthetic components

Retrospektive Datenanalyse innerhalb eines Patientengutes zur Evaluation des Outcome nach Wurzelspitzenresektion mit oder ohne vorheriger Wurzelkanalrevision.

1. Zusammenfassung 1.1. Hintergrund und Ziele Die nachfolgende Studie untersucht die Auswirkungen einer präoperativen Wurzelkanalrevision auf den Erfolg einer folgenden Wurzelspitzenresektion. Darüber hinaus wird der Einfluss einer retrograden Wurzelkanalfüllung auf das Outcome der Wurzelspitzenresektion untersucht. 1.2. Methoden Alle Patienten der Mund-Kiefer- und Gesichtschirurgie des Universitätsklinikums Erlangen, die zwischen 2011 und 2017 eine Wurzelspitzenresektion erhielten, wurden erfasst und in 2 Hauptgruppen aufgeteilt. Gruppe I erhielt eine zusätzliche präoperative Wurzelkanalrevision vor der Resektion, Gruppe II wurde nur reseziert. Beide Hauptgruppen wurden nochmals in jeweils zwei Untergruppen aufgeteilt (Ia, Ib und IIa, IIb), abhängig davon, ob die Zähne bei der Resektion eine retrograde Wurzelkanalfüllung erhalten haben oder nicht (Ia/IIa mit retrograder Wurzelkanalfüllung, Ib/IIb ohne retrograde Wurzelfüllung). In die Untersuchung inkludiert wurden somit 4 Patientengruppen mit jeweils unterschiedlichen therapeutischen Vorgehensweisen. Die Auswertung erfolgte mittels klinischer (Zahn in Situ) und radiographischer Parameter (Veränderung der Periapical-Index (PAI)-Werte). 1.3. Ergebnisse 48 Zähne bzw. 58 Wurzeln von Frontzähnen (n=17), Prämolaren (n=16) und Molaren (n=25) wurden reseziert. Bei einem mittleren Nachsorgeintervall von 14,8 Monaten lag die klinische Überlebensrate über alle Gruppen hinweg bei 75,9%. Die klinischen Erfolgsquoten der einzelnen Patientengruppen lagen bei 85,7% (Gruppe Ia), 77,7% (Gruppe Ib), 78,9% (Gruppe IIa) und 62,5% (Gruppe IIb). Die radiographischen Erfolgsquoten lagen mit 64,3% (Gruppe Ia), 62,5% (Gruppe Ib), 33,3% (Gruppe IIa) und 18,8% (Gruppe IIb) niedriger. 1.4. Schlussfolgerungen Bei den Untersuchungen für diese Arbeit haben sowohl die präoperative Wurzelkanalrevision als auch die retrograde Wurzelkanalfüllung einen positiven Einfluss auf die Erfolgsquote der Wurzelspitzenresektion aufgezeigt und können somit als ergänzende Therapiemaßnahmen bei der Wurzelspitzenresektion empfohlen werden, um ihre Erfolgsaussichten zu maximieren

Development of a thermoelectric module suitable for vehicles and based on CoSb3 manufactured close to production

Despite the ongoing electrification of vehicle propulsion systems, vehicles with combustion engines will continue to bear the brunt of passenger services world-wide for the next few decades. As a result, the DLR Institute of Vehicle Concepts, the Institute of Materials Research and the Institute of Technical Thermodynamics have focused on utilising the exhaust heat of internal combustion engines by means of thermoelectric generators (TEGs). Their primary goal is the development of cost-efficient TEGs with long-term stability and maximised energy yield. In addition to the overall TEG system design, the development of long-term stable, efficient thermoelectric modules (TEMs) for high-temperature applications is a great challenge. This paper presents the results of internal development work and reveals an expedient module design for use in TEGs suitable for vehicles. The TEM requirements identified, which were obtained by means of experiments on the test vehicle and test bench, are described first. Doped semiconductor materials were produced and characterised by production methods capable of being scaled up in order to represent series application. The results in terms of thermoelectric properties (Seebeck coefficient, electrical conductivity and thermal conductivity) were used for the simulative design of a thermoelectric module using a constant-property model and with the aid of FEM calculations. Thermomechanical calculations of material stability were carried out in addition to the TEM's thermodynamic and thermoelectric design. The film sequence within the module represented a special challenge. Multilayer films facilitated adaptation of the thermal and mechanical properties of plasma-sprayed films. A joint which dispenses with solder additives was also possible using multilayer films. The research resulted in a functionally-optimised module design, which was enhanced for use in motor vehicles using process flexibility and close-to-production manufacturing methods

Concept of a Thermoelectric Module and Generator for Automotive Applications Based on an Integrated Functional Design

Despite the ongoing electrification of vehicle propulsion systems, combustion engine vehicles will continue to bear the brunt of passenger and goods transport world-wide for the next several years. A major challenge of the automotive industry is the achievement of the required reduction of CO2 emissions for internal combustion engines. Therefore, it is necessary to investigate all potential technologies to improve efficiency. Regardless of whether a conventional or hybrid vehicle concept is used, up to approximately 40 percent of the fuels chemical energy is lost as waste heat in the exhaust system. As a result, the DLR Institute of Vehicle Concepts, the Institute of Technical Thermodynamics and the Institute of Materials Research focus on utilizing exhaust heat through thermoelectric generators (TEG) in the DLR project Next Generation Car (NGC). Their primary goals are the development of cost-efficient thermoelectric modules (TEM) and TEGs with long-term stability and a maximized energy yield. In addition to overall TEG system design, the development of long-term stable, efficient TEMs for high-temperature applications is a great challenge. This paper presents the results of internal development activities and demonstrates integrated functional designs of the TEM and TEG. The concept of contacting the TEMs on the surface of the heat exchanger of the TEG will be discussed. The thermodynamic boundary conditions are identified in this connection as well as the thermomechanical interactions. The connection is based on an innovative plasma-sprayed multilayer film. Moreover, the implemented thermodynamic, thermoelectric and thermomechanical models are described. The research results in an integrated functional design, which is primarily focused on high converter efficiency and low manufacturing complexity for the automotive applications