In medical image analysis, automated segmentation of multi-component anatomical structures, which often have a spectrum of potential anomalies and pathologies, is a challenging task. In this work, we develop a multi-step approach using U-Net-based neural networks to initially detect anomalies (bone marrow lesions, bone cysts) in the distal femur, proximal tibia and patella from 3D magnetic resonance (MR) images of the knee in individuals with varying grades of osteoarthritis. Subsequently, the extracted data are used for downstream tasks involving semantic segmentation of individual bone and cartilage volumes as well as bone anomalies. For anomaly detection, the U-Net-based models were developed to reconstruct the bone profiles of the femur and tibia in images via inpainting so anomalous bone regions could be replaced with close to normal appearances. The reconstruction error was used to detect bone anomalies. A second anomaly-aware network, which was compared to anomaly-na\"ive segmentation networks, was used to provide a final automated segmentation of the femoral, tibial and patellar bones and cartilages from the knee MR images containing a spectrum of bone anomalies. The anomaly-aware segmentation approach provided up to 58% reduction in Hausdorff distances for bone segmentations compared to the results from the anomaly-na\"ive segmentation networks. In addition, the anomaly-aware networks were able to detect bone lesions in the MR images with greater sensitivity and specificity (area under the receiver operating characteristic curve [AUC] up to 0.896) compared to the anomaly-na\"ive segmentation networks (AUC up to 0.874).
translated by 谷歌翻译
传统上,使用漫长的图像处理技术(如FreeSurfer,Cat或civet)解决了磁共振成像的皮质表面重建问题。这些框架需要很长的时间来实时应用不可行,并且对于大规模研究而言是不可行的。最近,已经引入了监督的深度学习方法,以加快这项任务,从而将重建时间从小时到几秒钟。本文将最新的皮质流模型作为蓝图,提出了三个修改,以提高其与现有的表面分析工具的准确性和互操作性,同时又不牺牲其快速推理时间和较低的GPU记忆消耗。首先,我们采用更准确的ODE求解器来减少差异映射近似误差。其次,我们设计了一个例程来产生更平滑的模板网格,避免了由皮质流的基于凸形壳模板中尖锐边缘引起的网格伪像。最后,我们重新铸造表面预测为预测的白色表面的变形,从而导致白色和伴侣表面顶点之间的一对一映射。该映射对于许多现有的表面形态计量学的表面分析工具至关重要。我们将结果方法命名CorticalFlow $^{++} $。使用大规模数据集,我们证明了所提出的更改提供了更高的几何准确性和表面规律性,同时几乎保持了重建时间和GPU记忆要求几乎没有变化。
translated by 谷歌翻译
Data scarcity is common in deep learning models for medical image segmentation. Previous works proposed multi-dataset learning, either simultaneously or via transfer learning to expand training sets. However, medical image datasets have diverse-sized images and features, and developing a model simultaneously for multiple datasets is challenging. This work proposes Fabric Image Representation Encoding Network (FIRENet), a universal architecture for simultaneous multi-dataset segmentation and transfer learning involving arbitrary numbers of dataset(s). To handle different-sized image and feature, a 3D fabric module is used to encapsulate many multi-scale sub-architectures. An optimal combination of these sub-architectures can be implicitly learnt to best suit the target dataset(s). For diverse-scale feature extraction, a 3D extension of atrous spatial pyramid pooling (ASPP3D) is used in each fabric node for a fine-grained coverage of rich-scale image features. In the first experiment, FIRENet performed 3D universal bone segmentation of multiple musculoskeletal datasets of the human knee, shoulder and hip joints and exhibited excellent simultaneous multi-dataset segmentation performance. When tested for transfer learning, FIRENet further exhibited excellent single dataset performance (when pre-training on a prostate dataset), as well as significantly improved universal bone segmentation performance. The following experiment involves the simultaneous segmentation of the 10 Medical Segmentation Decathlon (MSD) challenge datasets. FIRENet demonstrated good multi-dataset segmentation results and inter-dataset adaptability of highly diverse image sizes. In both experiments, FIRENet's streamlined multi-dataset learning with one unified network that requires no hyper-parameter tuning.
translated by 谷歌翻译
We present a generalised architecture for reactive mobile manipulation while a robot's base is in motion toward the next objective in a high-level task. By performing tasks on-the-move, overall cycle time is reduced compared to methods where the base pauses during manipulation. Reactive control of the manipulator enables grasping objects with unpredictable motion while improving robustness against perception errors, environmental disturbances, and inaccurate robot control compared to open-loop, trajectory-based planning approaches. We present an example implementation of the architecture and investigate the performance on a series of pick and place tasks with both static and dynamic objects and compare the performance to baseline methods. Our method demonstrated a real-world success rate of over 99%, failing in only a single trial from 120 attempts with a physical robot system. The architecture is further demonstrated on other mobile manipulator platforms in simulation. Our approach reduces task time by up to 48%, while also improving reliability, gracefulness, and predictability compared to existing architectures for mobile manipulation. See https://benburgesslimerick.github.io/ManipulationOnTheMove for supplementary materials.
translated by 谷歌翻译
在硅组织模型中,可以评估磁共振成像的定量模型。这包括对成像生物标志物和组织微结构参数的验证和灵敏度分析。我们提出了一种新的方法来生成心肌微结构的现实数值幻影。我们扩展了以前的研究,该研究考虑了心肌细胞的变异性,心肌细胞(插入式椎间盘)之间的水交换,心肌微结构混乱和四个钣金方向。在该方法的第一阶段,心肌细胞和钣金是通过考虑心肌到骨膜细胞连接的形状变异性和插入式椎间盘而产生的。然后,将薄板汇总和定向在感兴趣的方向上。我们的形态计量学研究表明,数值和真实(文献)心肌细胞数据的体积,长度以及一级和次要轴的分布之间没有显着差异($ p> 0.01 $)。结构相关性分析证实了硅内组织与实际组织的混乱类别相同。此外,心肌细胞的模拟螺旋角(HA)和输入HA(参考值)之间的绝对角度差($ 4.3^\ Circ \ PM 3.1^\ Circ $)与所测量HA之间的绝对角差有很好的一致性使用实验性心脏扩散张量成像(CDTI)和组织学(参考值)(Holmes等,2000)($ 3.7^\ Circ \ PM6.4^\ Circ $)和(Scollan等,1998)($ 4.9) ^\ circ \ pm 14.6^\ circ $)。使用结构张量成像(黄金标准)和实验性CDTI,输入和模拟CDTI的特征向量和模拟CDTI的角度之间的角度距离小于测量角度之间的角度距离。这些结果证实,所提出的方法比以前的研究可以为心肌产生更丰富的数值幻象。
translated by 谷歌翻译
对于基于MR物理学的模拟,对虚拟心脏MR图像的数据库进行了极大的兴趣,以开发深度学习分析网络。但是,这种数据库的使用受到限制或由于现实差距,缺失纹理以及模拟图像的简化外观而显示出次优性能。在这项工作中,我们1)在虚拟XCAT主题上提供不同的解剖学模拟,以及2)提出SIM2Real翻译网络以改善图像现实主义。我们的可用性实验表明,SIM2REAL数据具有增强训练数据并提高分割算法的性能的良好潜力。
translated by 谷歌翻译
基于坐标的体积表示有可能从图像中生成光真实的虚拟化身。但是,即使是可能未观察到的新姿势,虚拟化身也需要控制。传统技术(例如LBS)提供了这样的功能;但是,通常需要手工设计的车身模板,3D扫描数据和有限的外观模型。另一方面,神经表示在表示视觉细节方面具有强大的作用,但在变形的动态铰接式参与者方面受到了探索。在本文中,我们提出了TAVA,这是一种基于神经表示形式创建无象光动画体积参与者的方法。我们仅依靠多视图数据和跟踪的骨骼来创建演员的体积模型,该模型可以在给定的新颖姿势的测试时间中进行动画。由于塔瓦不需要身体模板,因此它适用于人类以及其他动物(例如动物)。此外,Tava的设计使其可以恢复准确的密集对应关系,从而使其适合于内容创建和编辑任务。通过广泛的实验,我们证明了所提出的方法可以很好地推广到新颖的姿势以及看不见的观点和展示基本的编辑功能。
translated by 谷歌翻译
我们研究了如何将高分辨率触觉传感器与视觉和深度传感结合使用,以改善掌握稳定性预测。在模拟高分辨率触觉传感的最新进展,尤其是触觉模拟器,使我们能够评估如何结合感应方式训练神经网络。借助训练大型神经网络所需的大量数据,机器人模拟器提供了一种快速自动化数据收集过程的方法。我们通过消融研究扩展现有工作,并增加了从YCB基准组中获取的一组对象。我们的结果表明,尽管视觉,深度和触觉感测的组合为已知对象提供了最佳预测结果,但该网络未能推广到未知对象。我们的工作还解决了触觉模拟中机器人抓握的现有问题以及如何克服它们。
translated by 谷歌翻译
本文介绍了DGBench,这是一种完全可重现的开源测试系统,可在机器人和对象之间具有不可预测的相对运动的环境中对动态抓握进行基准测试。我们使用拟议的基准比较几种视觉感知布置。由于传感器的最小范围,遮挡和有限的视野,用于静态抓握的传统感知系统无法在掌握的最后阶段提供反馈。提出了一个多摄像机的眼睛感知系统,该系统具有比常用的相机配置具有优势。我们用基于图像的视觉宣传控制器进行定量评估真实机器人的性能,并在动态掌握任务上显示出明显提高的成功率。
translated by 谷歌翻译
机器学习,在深入学习的进步,在过去分析时间序列方面表现出巨大的潜力。但是,在许多情况下,可以通过将其结合到学习方法中可能改善预测的附加信息。这对于由例如例如传感器位置的传感器网络而产生的数据至关重要。然后,可以通过通过图形结构建模,以及顺序(时间)信息来利用这种空间信息。适应深度学习的最新进展在各种图形相关任务中表明了有希望的潜力。但是,这些方法尚未在很大程度上适用于时间序列相关任务。具体而言,大多数尝试基本上围绕空间 - 时间图形神经网络巩固了时间序列预测的小序列长度。通常,这些架构不适合包含大数据序列的回归或分类任务。因此,在这项工作中,我们使用图形神经网络的好处提出了一种能够在多变量时间序列回归任务中处理这些长序列的架构。我们的模型在包含地震波形的两个地震数据集上进行测试,其中目标是预测在一组站的地面摇动的强度测量。我们的研究结果表明了我们的方法的有希望的结果,这是深入讨论的额外消融研究。
translated by 谷歌翻译