Toward multiple catheters detection in fluoroscopic image guided interventions

Catheters are routinely inserted via vessels to cavities of the heart during fluoroscopic image guided interventions for electrophysiology (EP) procedures such as ablation. During such interventions, the catheter undergoes nonrigid deformation due to physician interaction, patient's breathing, and cardiac motions. EP clinical applications can benefit from fast and accurate automatic catheter tracking in the fluoroscopic images. The typical low quality in fluoroscopic images and the presence of other medical instruments in the scene make the automatic detection and tracking of catheters in clinical environments very challenging. Toward the development of such an application, a robust and efficient method for detecting and tracking the catheter sheath is developed. The proposed approach exploits the clinical setup knowledge to constrain the search space while boosting both tracking speed and accuracy, and is based on a computationally efficient framework to trace the sheath and simultaneously detect one or multiple catheter tips. The algorithm is based on a modification of the fast marching weighted distance computation that efficiently calculates, on the fly, important geodesic properties in relevant regions of the image. This is followed by a cascade classifier for detecting the catheter tips. The proposed technique is validated on 1107 fluoroscopic images acquired on multiple patients across four different clinics, achieving multiple catheter tracking at a rate of 10 images/s with a very low false positive rate of 1.06.     

Assessing the way people look to judge their intentions.

[Correction Notice: An erratum for this article was reported in Vol 11(4) of Emotion (see record 2011-13790-001). Figure 1 should have been printed in color.] [Correction Notice: An erratum for this article was reported in Emotion July 4 2011 (see record 2011-13790-001). Figure 1, which should have been printed in color, was inadvertently printed in black and white. The online version has been corrected.] Faces of unknown persons are processed to infer the intentions of these persons not only when they depict full-blown emotions, but also at rest, or when these faces do not signal any strong feelings. We explored the brain processes involved in these inferences to test whether they are similar to those found when judging full-blown emotions. We recorded the event-related brain potentials (ERPs) elicited by faces of unknown persons who, when they were photographed, were not asked to adopt any particular expression. During the ERP recording, participants had to decide whether each face appeared to be that of a positively, negatively, ambiguously, or neutrally intentioned person. The early posterior negativity, the EPN, was found smaller for neutrally categorized faces than for the other faces, suggesting that the automatic processes it indexes are similar to those evoked by full-blown expressions and thus that these processes might be involved in the decoding of intentions. In contrast, in the same 200–400 ms time window, ERPs were not more negative at anterior sites for neutrally intentioned faces. Second, the peaks of the late positive potentials (LPPs) maximal at parietal sites around 700 ms postonset were not significantly smaller for neutrally intentioned faces. Third, the slow positive waves that followed the LPP were larger for faces that took more time to categorize, that is, for ambiguously intentioned faces. These three series of unexpected results may indicate processes similar to those triggered by full-blown emotions studies, but they question the characteristics of these processes. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Reconstructing the 3D shape and bone mineral density distribution of the proximal femur from dual-energy X-ray absorptiometry

The accurate diagnosis of osteoporosis has gained increasing importance due to the aging of our society. Areal bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) is an established criterion in the diagnosis of osteoporosis. This measure, however, is limited by its two-dimensionality. This work presents a method to reconstruct both the 3D bone shape and 3D BMD distribution of the proximal femur from a single DXA image used in clinical routine. A statistical model of the combined shape and BMD distribution is presented, together with a method for its construction from a set of quantitative computed tomography (QCT) scans. A reconstruction is acquired in an intensity based 3D-2D registration process whereby an instance of the model is found that maximizes the similarity between its projection and the DXA image. Reconstruction experiments were performed on the DXA images of 30 subjects, with a model constructed from a database of QCT scans of 85 subjects. The accuracy was evaluated by comparing the reconstructions with the same subject QCT scans. The method presented here can potentially improve the diagnosis of osteoporosis and fracture risk assessment from the low radiation dose and low cost DXA devices currently used in clinical routine.     

Two primer pairs to detect OTA producers by PCR method

Fungi contaminating foods and feeds may produce many mycotoxins including ochratoxin A (OTA). Early and rapid detection of potential OTA producing fungi is important to reduce the negative impacts of OTA. In this study, two PCR specific primer pairs, AoLC35-12L/AoLC35-12R and AoOTAL/AoOTAR, were designed from a DNA sequence of a polyketide synthase gene in Aspergillus ochraceus NRRL 3174. On 14 different fungi tested by PCR, AoLC35-12L/AoLC35-12R amplified a unique band from either OTA or citrinin producers while AoOTAL/AoOTAR amplified one PCR product only from A. ochraceus. So these primers could be used to detect both OTA and citrinin producing fungi (AoLC35-12L/AoLC35-12R) or only A. ochraceus (AoOTAL/AoOTAR) from foodstuffs using PCR method.     

Investigation of pre-structured GaAs surfaces for subsequent site-selective InAs quantum dot growth

In this study, we investigated pre-structured (100) GaAs sample surfaces with respect to subsequent site-selective quantum dot growth. Defects occurring in the GaAs buffer layer grown after pre-structuring are attributed to insufficient cleaning of the samples prior to regrowth. Successive cleaning steps were analyzed and optimized. A UV-ozone cleaning is performed at the end of sample preparation in order to get rid of remaining organic contamination.     

The role of electrical current mode in calcium carbonate deposition on conductive carbon nanofiber–epoxy coating

Calcium carbonate is one of the most common scaling minerals. In this paper we have used different electrical current modes (direct current [DC], pulsed DC, and alternating current [AC]) to control the amount, morphology, and distribution of calcium carbonate deposit on electroconductive epoxy/carbon nanofiber (CNF) coating. The effect of different current modes on surface scaling was visualized using scanning electron microscopy. It has been shown that both AC and DC anodic polarization limited scale deposition on epoxy/CNF coated surfaces, although the mechanisms of scale inhibition during AC and DC polarization were different. DC polarization of the coating at +2 V resulted in the smallest scale buildup without leading to coating degradation, while DC polarization at potentials as high as +5 V caused the coating to degrade. Interestingly, application of pulsed DC with high pulse frequency (50 Hz) inhibited the degradation. The type of current applied affected also the morphology of the precipitate at the cathode. The results presented in this work show, for the first time, how different modes of electrical current applied to electroconductive composite coatings can be used to control the morphology and distribution of calcium carbonate scale, and how the organic coating degradation at high polarization potentials can be avoided.     

High‐efficiency microcrystalline silicon single‐junction solar cells

This short communication highlights our latest results towards high‐efficiency microcrystalline silicon single‐junction solar cells. By combining adequate cell design with high‐quality material, a new world record efficiency was achieved for single‐junction microcrystalline silicon solar cell, with a conversion efficiency of 10.69%, independently confirmed at ISE CalLab PV Cells. Such significant conversion efficiency could be achieved with only 1.8 µm of Si. Copyright © 2013 John Wiley & Sons, Ltd.