CHEOPS: a space telescope for ultra-high precision photometry of exoplanet transits

The CHaracterising ExOPlanet Satellite (CHEOPS) is a joint ESA-Switzerland space mission (expected to launch in 2017) dedicated to search for exoplanet transits by means of ultra-high precision photometry. CHEOPS will provide accurate radii for planets down to Earth size. Targets will mainly come from radial velocity surveys. The CHEOPS instrument is an optical space telescope of 30 cm clear aperture with a single focal plane CCD detector. The tube assembly is passively cooled and thermally controlled to support high precision, low noise photometry. The telescope feeds a re-imaging optic, which supports the straylight suppression concept to achieve the required Signal to Noise. © (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

SALSA: a tool to estimate the stray light contamination for low-Earth orbit observatories

Stray light contamination reduces considerably the precision of photometric of faint stars for low altitude spaceborne observatories. When measuring faint objects, the necessity of coping with stray light contamination arises in order to avoid systematic impacts on low signal-to-noise images. Stray light contamination can be represented by a flat offset in CCD data. Mitigation techniques begin by a comprehensive study during the design phase, followed by the use of target pointing optimisation and post-processing methods. We present a code that aims at simulating the stray-light contamination in low-Earth orbit coming from reflexion of solar light by the Earth. StrAy Light SimulAtor (SALSA) is a tool intended to be used at an early stage as a tool to evaluate the effective visible region in the sky and, therefore to optimise the observation sequence. SALSA can compute Earth stray light contamination for significant periods of time allowing missionwide parameters to be optimised (e.g. impose constraints on the point source transmission function (PST) and/or on the altitude of the satellite). It can also be used to study the behaviour of the stray light at different seasons or latitudes. Given the position of the satellite with respect to the Earth and the Sun, SALSA computes the stray light at the entrance of the telescope following a geometrical technique. After characterising the illuminated region of the Earth, the portion of illuminated Earth that affects the satellite is calculated. Then, the flux of reflected solar photons is evaluated at the entrance of the telescope. Using the PST of the instrument, the final stray light contamination at the detector is calculated. The analysis tools include time series analysis of the contamination, evaluation of the sky coverage and an objects visibility predictor. Effects of the South Atlantic Anomaly and of any shutdown periods of the instrument can be added. Several designs or mission concepts can be easily tested and compared. The code is not thought as a stand-alone mission designer. Its mandatory inputs are a time series describing the trajectory of the satellite and the characteristics of the instrument. This software suite has been applied to the design and analysis of CHEOPS (CHaracterizing ExOPlanet Satellite). This mission requires very high precision photometry to detect very shallow transits of exoplanets. Different altitudes and characteristics of the detector have been studied in order to find the best parameters, that reduce the effect of contamination. © (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

Standardized definitions and clinical endpoints in carotid artery and supra-aortic trunk revascularization trials

Endovascular therapy has emerged as a promising alternative to open surgery for stroke prevention in patients with obstructive disease of the supra-aortic arteries. Although most previous studies have used similar safety and efficacy endpoints, differences in definitions, timing of assessments, and standards of reporting have hampered direct comparisons across various trials.

Figulla PFO occluder versus Amplatzer PFO occluder for percutaneous closure of patent foramen ovale

Percutaneous closure of patent foramen ovale (PFO) has been shown safe and feasible using several devices. The Occlutech Figulla single layer PFO Occluder (FPO) constitutes an alternative to the Amplatzer PFO Occluder (APFO).

All comers 5 french transfemoral percutaneous coronary intervention without sheath

There is an interest to keep the arterial access site for percutaneous coronary interventions (PCI) small. Using sheaths for introduction of arterial catheters is standard. The effective outer diameter of the usual introducer sheaths is about 1.5 French (F) larger than the labeled size. Omitting the sheath affords a smaller access without loss of working lumen.

"Device landing zone" calcification, assessed by MSCT, as a predictive factor for pacemaker implantation after TAVI

After trans-catheter aortic valve implantation (TAVI), the need for postinterventional pacemaker (PM) implantation can occur in as many as 10-50% of cases, but it is not yet clear, how this need can be predicted. The aim of this study was to assess the possible predictive factors of post TAVI PM implantation based on Computed Tomography (CT) measured aortic valve calcification and its distribution.

Left atrial appendage closure with amplatzer cardiac plug in atrial fibrillation: initial European experience

In most patients with atrial fibrillation (AF) and stroke, there is thrombotic embolization from the left atrial appendage (LAA). Percutaneous closure of the LAA is a novel alternative for the treatment of patients with AF at a high risk of stroke, in whom long-term anticoagulation therapy is not possible or not desired. This study details the initial experience with the Amplatzer Cardiac Plug (ACP) in humans.