心房颤动的计算模型已成功地用于预测最佳消融部位。评估消融模式的效果的关键步骤是从不同,潜在的随机的位置加速模型以确定是否可以在ATRIA中诱导心律失常。在这项工作中,我们建议使用黎曼歧管的多保真高斯过程分类,以有效地确定心律失常是诱导性诱导的区域内的区域。我们构建一个直接在心房表面上运行的概率分类器。我们利用较低的分辨率模型来探索心房表面,并与高分辨率模型无缝结合,以识别诱导区域。当用40个样本培训时,我们的多保真性分级器显示了比使用作为基线心房颤动模型的最近邻分类器的均衡精度,并且在心房颤动的情况下具有9%。我们希望这种新技术将允许更快,更精确地对心房颤动的计算模型临床应用。
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To analyze this characteristic of vulnerability, we developed an automated deep learning method for detecting microvessels in intravascular optical coherence tomography (IVOCT) images. A total of 8,403 IVOCT image frames from 85 lesions and 37 normal segments were analyzed. Manual annotation was done using a dedicated software (OCTOPUS) previously developed by our group. Data augmentation in the polar (r,{\theta}) domain was applied to raw IVOCT images to ensure that microvessels appear at all possible angles. Pre-processing methods included guidewire/shadow detection, lumen segmentation, pixel shifting, and noise reduction. DeepLab v3+ was used to segment microvessel candidates. A bounding box on each candidate was classified as either microvessel or non-microvessel using a shallow convolutional neural network. For better classification, we used data augmentation (i.e., angle rotation) on bounding boxes with a microvessel during network training. Data augmentation and pre-processing steps improved microvessel segmentation performance significantly, yielding a method with Dice of 0.71+/-0.10 and pixel-wise sensitivity/specificity of 87.7+/-6.6%/99.8+/-0.1%. The network for classifying microvessels from candidates performed exceptionally well, with sensitivity of 99.5+/-0.3%, specificity of 98.8+/-1.0%, and accuracy of 99.1+/-0.5%. The classification step eliminated the majority of residual false positives, and the Dice coefficient increased from 0.71 to 0.73. In addition, our method produced 698 image frames with microvessels present, compared to 730 from manual analysis, representing a 4.4% difference. When compared to the manual method, the automated method improved microvessel continuity, implying improved segmentation performance. The method will be useful for research purposes as well as potential future treatment planning.
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已经开发了各种方法来结合多组结果的推理,以在集合和共识聚类文献中进行无监督的聚类。从几个候选聚类模型中的一个“最佳”模型报告结果的方法通常忽略了由模型选择产生的不确定性,并且导致对所选择的特定模型和参数敏感的推论,以及制作的假设,尤其是在小样本中所做的假设。尺寸或小簇尺寸。贝叶斯模型平均(BMA)是一种在多种模型中结合结果的流行方法,这些模型在这种情况下提供了一些有吸引力的好处,包括对组合集群结构的概率解释和基于模型的不确定性的量化。在这项工作中,我们介绍了ClusterBMA,该方法可以通过多种无监督聚类算法进行加权模型平均。我们将聚类内部验证标准的组合用作后验模型概率的新近似值,以加权每个模型的结果。从代表跨模型的聚类溶液的加权平均值的组合后相似性矩阵,我们应用对称的单纯形矩阵分解来计算最终的概率群集分配。此方法在随附的R软件包中实现。我们通过案例研究探索这种方法的性能,该案例研究旨在根据脑电图(EEG)数据识别个体的概率簇。我们还使用仿真数据集探索所提出的技术识别稳健的集成簇具有不同级别的集成簇,并在子组之间的分离水平变化,并且模型之间的簇数量变化。
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