525 research outputs found
Personalized ablation vs. conventional ablation strategies to terminate atrial fibrillation and prevent recurrence
Aims
The long-term success rate of ablation therapy is still sub-optimal in patients with persistent atrial fibrillation (AF), mostly due to arrhythmia recurrence originating from arrhythmogenic sites outside the pulmonary veins. Computational modelling provides a framework to integrate and augment clinical data, potentially enabling the patient-specific identification of AF mechanisms and of the optimal ablation sites. We developed a technology to tailor ablations in anatomical and functional digital atrial twins of patients with persistent AF aiming to identify the most successful ablation strategy.
Methods and results
Twenty-nine patient-specific computational models integrating clinical information from tomographic imaging and electro-anatomical activation time and voltage maps were generated. Areas sustaining AF were identified by a personalized induction protocol at multiple locations. State-of-the-art anatomical and substrate ablation strategies were compared with our proposed Personalized Ablation Lines (PersonAL) plan, which consists of iteratively targeting emergent high dominant frequency (HDF) regions, to identify the optimal ablation strategy. Localized ablations were connected to the closest non-conductive barrier to prevent recurrence of AF or atrial tachycardia. The first application of the HDF strategy had a success of >98% and isolated only 5–6% of the left atrial myocardium. In contrast, conventional ablation strategies targeting anatomical or structural substrate resulted in isolation of up to 20% of left atrial myocardium. After a second iteration of the HDF strategy, no further arrhythmia episode could be induced in any of the patient-specific models.
Conclusion
The novel PersonAL in silico technology allows to unveil all AF-perpetuating areas and personalize ablation by leveraging atrial digital twins
Recent Progress in Image Deblurring
This paper comprehensively reviews the recent development of image
deblurring, including non-blind/blind, spatially invariant/variant deblurring
techniques. Indeed, these techniques share the same objective of inferring a
latent sharp image from one or several corresponding blurry images, while the
blind deblurring techniques are also required to derive an accurate blur
kernel. Considering the critical role of image restoration in modern imaging
systems to provide high-quality images under complex environments such as
motion, undesirable lighting conditions, and imperfect system components, image
deblurring has attracted growing attention in recent years. From the viewpoint
of how to handle the ill-posedness which is a crucial issue in deblurring
tasks, existing methods can be grouped into five categories: Bayesian inference
framework, variational methods, sparse representation-based methods,
homography-based modeling, and region-based methods. In spite of achieving a
certain level of development, image deblurring, especially the blind case, is
limited in its success by complex application conditions which make the blur
kernel hard to obtain and be spatially variant. We provide a holistic
understanding and deep insight into image deblurring in this review. An
analysis of the empirical evidence for representative methods, practical
issues, as well as a discussion of promising future directions are also
presented.Comment: 53 pages, 17 figure
Deep Learning Techniques for Video Instance Segmentation: A Survey
Video instance segmentation, also known as multi-object tracking and
segmentation, is an emerging computer vision research area introduced in 2019,
aiming at detecting, segmenting, and tracking instances in videos
simultaneously. By tackling the video instance segmentation tasks through
effective analysis and utilization of visual information in videos, a range of
computer vision-enabled applications (e.g., human action recognition, medical
image processing, autonomous vehicle navigation, surveillance, etc) can be
implemented. As deep-learning techniques take a dominant role in various
computer vision areas, a plethora of deep-learning-based video instance
segmentation schemes have been proposed. This survey offers a multifaceted view
of deep-learning schemes for video instance segmentation, covering various
architectural paradigms, along with comparisons of functional performance,
model complexity, and computational overheads. In addition to the common
architectural designs, auxiliary techniques for improving the performance of
deep-learning models for video instance segmentation are compiled and
discussed. Finally, we discuss a range of major challenges and directions for
further investigations to help advance this promising research field
Sustainable government policy as silver bullet to sustainable business incubation performance In Nigeria
Business incubation has variously been described as a support programme that assist the early-stage entrepreneurs to develop and stay on their own. Furthermore, business incubation programme has been acknowledged as an economic development tool most countries globally adopted. The aim of this study is to examine the contribution of government policy on the relationship between the critical success factors (CSFs) and incubator performance in Nigeria. The questionnaire method of data collection was used to gather 113 usable questionnaires from incubatees in Nigeria’s business incubators. Structural Equation Modeling (SEM) was performed to determine the result using the Partial Least Square (PLS) Software. Government policy as a moderator did not show a significant moderation relationship between the CSF and incubator performance
An Automated Social Graph De-anonymization Technique
We present a generic and automated approach to re-identifying nodes in
anonymized social networks which enables novel anonymization techniques to be
quickly evaluated. It uses machine learning (decision forests) to matching
pairs of nodes in disparate anonymized sub-graphs. The technique uncovers
artefacts and invariants of any black-box anonymization scheme from a small set
of examples. Despite a high degree of automation, classification succeeds with
significant true positive rates even when small false positive rates are
sought. Our evaluation uses publicly available real world datasets to study the
performance of our approach against real-world anonymization strategies, namely
the schemes used to protect datasets of The Data for Development (D4D)
Challenge. We show that the technique is effective even when only small numbers
of samples are used for training. Further, since it detects weaknesses in the
black-box anonymization scheme it can re-identify nodes in one social network
when trained on another.Comment: 12 page
2016 Annual Research Symposium Abstract Book
2016 annual volume of abstracts for science research projects conducted by students at Trinity Colleg
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