Automated external defibrillators on board merchant vessels? Preliminary report Article for discussion

Objectives &#8211; Acute heart diseases are the most frequent causes for fatalities on merchant vessels. Presently there is no sufficient therapy available to treat ventricular fibrillation. The aim of this study was to test whether common automated external defibrillators [AED] may be appropriate for the use aboard merchant vessels. Methods &#8211; In 2005, nine seafarers were introduced to four common models of AED (HeartStartFR2+, Lifepak500, AEDplus, FREDeasy) using standard video or DVD presentations. AED handling by the subjects was tested in standardized simulated emergency scenarios. After training, they subjectively rated each AED on 24 factors involved in the introduction and handling of the device. An actual ECG was then obtained with each AED at a site located beside the ship&#8217;s main engine to test under maximum vibration. The ECG data were extracted and sent as an e-mail attachment via satellite to the German Telemedical Maritime Assistance Service [TMAS] in Cuxhaven. Results and conclusions &#8211; All subjects handled the AED correctly. The AED received a total amount of points in the range between 2125 to 2241 (of 2400 possible). The subjects preferred AED with coloured as well as light marked buttons which gave a feedback (e.g. audible tones) when they were pressed. All AED were able to register an ECG in the vibrating ambient. Due to interface problems it was only possible to extract three ECG files, and only two files (data < 300 kB) could be sent as e-mail attachment via satellite to the German TMAS. In noisy areas the AED must guide the user, e.g. by screen massages and/or pictograms. Displays should provide additional data to help assess resuscitation effectiveness. A special procedure is necessary to ensure that ships and TMAS own the same software to read the transmitted ECG files, which are not allowed to exceed a size of 300 kB

Confirmation of the topology of the Wendelstein 7-X magnetic field to better than 1:100,000

Fusion energy research has in the past 40 years focused primarily on the tokamak concept, but recent advances in plasma theory and computational power have led to renewed interest in stellarators. The largest and most sophisticated stellarator in the world, Wendelstein 7-X (W7-X), has just started operation, with the aim to show that the earlier weaknesses of this concept have been addressed successfully, and that the intrinsic advantages of the concept persist, also at plasma parameters approaching those of a future fusion power plant. Here we show the first physics results, obtained before plasma operation: that the carefully tailored topology of nested magnetic surfaces needed for good confinement is realized, and that the measured deviations are smaller than one part in 100,000. This is a significant step forward in stellarator research, since it shows that the complicated and delicate magnetic topology can be created and verified with the required accuracy

Major results from the first plasma campaign of the Wendelstein 7-X stellarator

After completing the main construction phase of Wendelstein 7-X (W7-X) and successfully commissioning the device, first plasma operation started at the end of 2015. Integral commissioning of plasma start-up and operation using electron cyclotron resonance heating (ECRH) and an extensive set of plasma diagnostics have been completed, allowing initial physics studies during the first operational campaign. Both in helium and hydrogen, plasma breakdown was easily achieved. Gaining experience with plasma vessel conditioning, discharge lengths could be extended gradually. Eventually, discharges lasted up to 6 s, reaching an injected energy of 4 MJ, which is twice the limit originally agreed for the limiter configuration employed during the first operational campaign. At power levels of 4 MW central electron densities reached 3 1019 m-3, central electron temperatures reached values of 7 keV and ion temperatures reached just above 2 keV. Important physics studies during this first operational phase include a first assessment of power balance and energy confinement, ECRH power deposition experiments, 2nd harmonic O-mode ECRH using multi-pass absorption, and current drive experiments using electron cyclotron current drive. As in many plasma discharges the electron temperature exceeds the ion temperature significantly, these plasmas are governed by core electron root confinement showing a strong positive electric field in the plasma centre.Peer reviewe