A Novel Haptic Interface for Free Locomotion in Extended Range Telepresence Scenarios

Telepresence gives a user the impression of actually being present in a distant environment. A mobile teleoperator acts as a proxy in this target environment, replicates the user\u27s motion, and records sensory information, which is transferred to the user and displayed in real-time. As a result the user is immersed in the target environment. The user can then control the teleoperator by walking naturally. Motion Compression, a nonlinear mapping between the user\u27s and the robot\u27s motion, allows exploration of large target environments even from small user environments. For manipulation tasks haptic feedback is important. However, current haptic displays do not allow wide-area motion. In this work we present our design of a novel haptic display for simultaneous wide area motion and haptic interaction

Carbon-assisted chemical vapor deposition of hexagonal boron nitride

We show that in a low-pressure chemical vapor deposition (CVD) system, the residual oxygen and/or air play a crucial role in the mechanism of the growth of hexagonal boron nitride (h-BN) films on Ni foil 'enclosures'. Hexagonal-BN films grow on the Ni foil surface via the formation of an intermediate boric-oxide (BOx) phase followed by a thermal reduction of the BOx by a carbon source (either amorphous carbon powder or methane), leading to the formation of single-and bi-layer h-N. Low energy electron microscopy (LEEM) and diffraction (LEED) were used to map the number of layers over large areas; Raman spectroscopy, time-of-flight secondary ion mass spectrometry (ToF-SIMS), x-ray photoelectron spectroscopy (XPS) and scanning tunneling microscopy (STM) were used to characterize the structure and physical quality of the ultra-thin h-BN film. The growth procedure reported here leads to a better understanding and control of the synthesis of ultra-thin h-BN films

Vergleichsstudie von Systemansätzen für das Schnellladen von Elektrofahrzeugen

One of the major challenges for a global success of electric vehicles is to meet customer\u27s expectations to a user–friendly charging infrastructure. The technology of fast charging of electric vehicles offers electric vehicle users the opportunity to travel in excess of the car’s range. Therefore, various system approaches and standards for fast charging of electric vehicles have been developed in several countries and by different manufacturers. Within the scope of this study existing approaches of system designs for fast charging of electric vehicles in different regions (China/Europe/USA/Japan) have been analyzed in terms of their technical, economical and legal feasibility. For this purpose the general system for fast charging has been defined and several evaluation criterions have been determined. Based on the system, the regarded system approaches have been compared due to their different features and abilities. To expedite the comprehensive implementation of the fast charging technology, it is recommended that the proponents of the different system approaches will work together to benefit from their respective experience. Consequently, they are able to accelerate the joint use of the large technically and economically useful potential of fast charging

Combined Coronary CT-Angiography and TAVI-Planning: A Contrast-Neutral Routine Approach for Ruling-Out Significant Coronary Artery Disease

Background: Significant coronary artery disease (CAD) is a common finding in patients undergoing transcatheter aortic valve implantation (TAVI). Assessment of CAD prior to TAVI is recommended by current guidelines and is mainly performed via invasive coronary angiography (ICA). In this study we analyzed the ability of coronary CT-angiography (cCTA) to rule out significant CAD (stenosis ≥ 50%) during routine pre-TAVI evaluation in patients with high pre-test probability for CAD. Methods: In total, 460 consecutive patients undergoing pre-TAVI CT (mean age 79.6 ± 7.4 years) were included. All patients were examined with a retrospectively ECG-gated CT-scan of the heart, followed by a high-pitch-scan of the vascular access route utilizing a single intravenous bolus of 70 mL iodinated contrast medium. Images were evaluated for image quality, calcifications, and significant CAD; CT-examinations in which CAD could not be ruled out were defined as positive (CAD+). Routinely, patients received ICA (388/460; 84.3%; Group A), which was omitted if renal function was impaired and CAD was ruled out on cCTA (Group B). Following TAVI, clinical events were documented during the hospital stay. Results: cCTA was negative for CAD in 40.2% (188/460). Sensitivity, specificity, PPV, and NPV in Group A were 97.8%, 45.2%, 49.6%, and 97.4%, respectively. Median coronary artery calcium score (CAC) was higher in CAD+-patients but did not have predictive value for correct classification of patients with cCTA. There were no significant differences in clinical events between Group A and B. Conclusion: cCTA can be incorporated into pre-TAVI CT-evaluation with no need for additional contrast medium. cCTA may exclude significant CAD in a relatively high percentage of these high-risk patients. Thereby, cCTA may have the potential to reduce the need for ICA and total amount of contrast medium applied, possibly making pre-procedural evaluation for TAVI safer and faster