Cardiovascular diseases are the most distributed cause of death worldwide. Stenting of arteries as a percutaneous transluminal angioplasty procedure became a promising minimally invasive therapy based on re-opening narrowed arteries by stent insertion. In order to improve and optimize this method, many research groups are focusing on designing new or improving existent stents. Since the beginning of the stent development in 1986, starting with bare-metal stents (BMS), these devices have been continuously enhanced by applying new materials, developing stent coatings based on inorganic and organic compounds including drugs, nanoparticles or biological components such as genes and cells, as well as adapting stent designs with different fabrication technologies. Drug eluting stents (DES) have been developed to overcome the main shortcomings of BMS or coated stents. Coatings are mainly applied to control biocompatibility, degradation rate, protein adsorption, and allow adequate endothelialization in order to ensure better clinical outcome of BMS, reducing restenosis and thrombosis. As coating materials (i) organic polymers: polyurethanes, poly(ε-caprolactone), styrene-b-isobutylene-b-styrene, polyhydroxybutyrates, poly(lactide-co-glycolide), and phosphoryl choline; (ii) biological components: vascular endothelial growth factor (VEGF) and anti-CD34 antibody and (iii) inorganic coatings: noble metals, wide class of oxides, nitrides, silicide and carbide, hydroxyapatite, diamond-like carbon, and others are used. DES were developed to reduce the tissue hyperplasia and in-stent restenosis utilizing antiproliferative substances like paclitaxel, limus (siro-, zotaro-, evero-, bio-, amphi-, tacro-limus), ABT-578, tyrphostin AGL-2043, genes, etc. The innovative solutions aim at overcoming the main limitations of the stent technology, such as in-stent restenosis and stent thrombosis, while maintaining the prime requirements on biocompatibility, biodegradability, and mechanical behavior. This paper provides an overview of the existing stent types, their functionality, materials, and manufacturing conditions demonstrating the still huge potential for the development of promising stent solutions.

During pregnancy, fetal ultrasound provides essential insight into a baby’s growth and development. In this ultrasound, accurate assessment of fetal head biometry is critical to the clinical management of pregnancy. Current methodologies used for fetal head biometry heavily rely upon sonographer skills and experience to locate a baby’s head. In this paper a novel approach is proposed to automate the fetal head biometry using live ultrasound feed; which is also capable of tackling low abdominal contrast against surroundings. Proposed model is trained on ALEXNET and UNET for classification and segmentation of headframes respectively from ultrasound video. To compute biparietal diameter (BPD) and head circumference (HC); which are essential requirements to compute gestational age, an ellipse is drawn on the contour of the annotated segmented fetal head. It should be noted that to validate gestational age estimate, ellipse are drawn on multiple best classified headframes obtained using ALEXNET. The proposed system is able to estimate gestational age within clinically acceptable ± one week of observed gestational age with an accuracy of 96%. Moreover, it uses robust machine vision features to reduce the sonographer’s interaction with the system, thus reducing the overall procedure time and making it independent of sonographer’s skill.

Coronary artery disease (CAD) affects every fifth person in the world. The gold-standard treatment for CAD is stent implantation, however, the existing therapy is not sufficient. In recent years, titanium oxynitride (TiO _x N _y ) coatings on bare metal stents (BMSs) attracted the attention of many researchers around the world due to their promising results and improved surface properties. However, good coating adhesion and coverage of the inner surface in stent applications is still a challenging task. Moreover, enhanced corrosion resistance and durability over a longer period under the influence of an aggressive biological environment is one of the main requirements while developing novel coatings for bare-metal stents. In this work, the titanium oxynitride (TiO _x N _y ) coated stainless steel stents were fabricated by magnetron sputtering and the corrosion behavior of coated and uncoated stents has been studied using immersion, fluid dynamic, and electrochemical corrosion tests. For the first time, the entire stent surface has been used for quantitative corrosion tests on stents. We discuss and compare the in vitro biostability and corrosion behavior of bare stainless steel (316L) and titanium oxynitride films (TiO _x N _y ) coated stents.TiO _x N _y coatings provide valuable stability to the BMS against harsh environments or conditions. The coated stents are remarkably more stable when compared with the reference uncoated stents (316L BMS), regardless of the ratio of O ₂ and N ₂ . The variation of stent coating parameters is still possible to get more anticorrosive and biostable behavior; therefore, the results could provide the basis for further research.