DAC-Less amplifier-less generation and transmission of QAM signals using sub-volt silicon-organic hybrid modulators

We demonstrate generation and transmission of optical signals by directly interfacing highly efficient silicon-organic hybrid (SOH) modulators to binary output ports of a field-programmable gate array. Using an SOH Mach-Zehnder modulator (MZM) and an SOH IQ modulator we generate ON-OFF- keying and binary phase-shift keying signals as well as quadrature phase-shift keying and 16-state quadrature amplitude modulation (16QAM) formats. Peak-to-peak voltages amount to only 0.27 V-pp for driving the MZM and 0.41 V-pp for the IQ modulator. Neither digital-to-analog converters nor drive amplifiers are required, and the RF energy consumption in the modulator amounts to record-low 18 fJ/bit for 16QAM signaling

Direct cooling of the catheter tip increases safety for CMR-guided electrophysiological procedures

<p>Abstract</p> <p>Background</p> <p>One of the safety concerns when performing electrophysiological (EP) procedures under magnetic resonance (MR) guidance is the risk of passive tissue heating due to the EP catheter being exposed to the radiofrequency (RF) field of the RF transmitting body coil. Ablation procedures that use catheters with irrigated tips are well established therapeutic options for the treatment of cardiac arrhythmias and when used in a modified mode might offer an additional system for suppressing passive catheter heating.</p> <p>Methods</p> <p>A two-step approach was chosen. Firstly, tests on passive catheter heating were performed in a 1.5 T Avanto system (Siemens Healthcare Sector, Erlangen, Germany) using a ASTM Phantom in order to determine a possible maximum temperature rise. Secondly, a phantom was designed for simulation of the interface between blood and the vascular wall. The MR-RF induced temperature rise was simulated by catheter tip heating via a standard ablation generator. Power levels from 1 to 6 W were selected. Ablation duration was 120 s with no tip irrigation during the first 60 s and irrigation at rates from 2 ml/min to 35 ml/min for the remaining 60 s (Biotronik Qiona Pump, Berlin, Germany). The temperature was measured with fluoroscopic sensors (Luxtron, Santa Barbara, CA, USA) at a distance of 0 mm, 2 mm, 4 mm, and 6 mm from the catheter tip.</p> <p>Results</p> <p>A maximum temperature rise of 22.4°C at the catheter tip was documented in the MR scanner. This temperature rise is equivalent to the heating effect of an ablator's power output of 6 W at a contact force of the weight of 90 g (0.883 N). The catheter tip irrigation was able to limit the temperature rise to less than 2°C for the majority of examined power levels, and for all examined power levels the residual temperature rise was less than 8°C.</p> <p>Conclusion</p> <p>Up to a maximum of 22.4°C, the temperature rise at the tissue surface can be entirely suppressed by using the catheter's own irrigation system. The irrigated tip system can be used to increase MR safety of EP catheters by suppressing the effects of unwanted passive catheter heating due to RF exposure from the MR scanner.</p

Systematische Widerstandsermittlung von SES-Ruempfen im glatten Wasser. T. 2

Available from TIB Hannover: RN 2770(1276,2)+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Modellversuche fuer eine Oelsperr- und Oelsammelvorrichtung

With 20 figs., 26 photosCopy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Leistungsbedarf von Schiffen bei Anordnung grosser, langsam laufender Propeller unter Beruecksichtigung von Trimm- und Tauchungseinfluessen (off-design conditions) Kurzfassung

TIB Hannover: RN 2770(1143)+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Untersuchung zum Einfluss von Aenderungen der Laenge des parallelen Mittelschiffes auf Widerstand, Propulsion und Nachstrom von Einschraubern Teil 1.2

SIGLETIB: RA 2207 (121)+(19) + RN 2770 (919)+(916) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Silicon-organic hybrid (SOH) integration for low-power and high-speed signal generation

Silicon-organic hybrid (SOH) integration combines silicon photonic devices with electro-optic organic cladding materials. We demonstrate that SOH modulators can be used to generate advanced modulation formats with high symbol rates at low operating voltages and low energy consumption. Moreover, we show that the SOH approach can be extended to plasmonic waveguide structures, leading to the plasmonic-organic hybrid (POH) concept