对疾病的诊断或图像分割医学图像训练计算机视觉相关算法是缺乏训练数据,标记的样品,和隐私问题的困难所致。出于这个原因,一个强大的生成方法来创建合成数据后高度寻求。然而,大多数三维图像生成器需要额外的图像输入或者是非常占用大量内存。为了解决这些问题,我们建议调整视频生成技术3-d图像生成。使用时间GAN(TGAN)架构,我们将展示我们能够产生逼真的头部和颈部PET图像。我们还表明,通过调节肿瘤口罩发电机,我们能够控制肿瘤的几何形状和位置,在生成的图像。为了测试合成影像的用途,我们使用合成的图像训练分割模型。空调真实肿瘤掩模合成图像被自动分割,和对应的真实图像也分割。我们评估使用的骰子得分的分割,并找到两个数据集(0.65合成数据,0.70的真实数据)同样的分割算法执行。然后,各种radionomic特征在分割的肿瘤体积为每个数据集来计算。真实的和合成的特征分布的比较显示,8七个特征分布有统计学不显着差异(p> 0.05)。还计算所有radionomic特征之间的相关系数,它是示出了所有在真实数据组中的强统计相关的在合成数据集被保留。
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A "heart attack" or myocardial infarction (MI), occurs when an artery supplying blood to the heart is abruptly occluded. The "gold standard" method for imaging MI is Cardiovascular Magnetic Resonance Imaging (MRI), with intravenously administered gadolinium-based contrast (late gadolinium enhancement). However, no "gold standard" fully automated method for the quantification of MI exists. In this work, we propose an end-to-end fully automatic system (MyI-Net) for the detection and quantification of MI in MRI images. This has the potential to reduce the uncertainty due to the technical variability across labs and inherent problems of the data and labels. Our system consists of four processing stages designed to maintain the flow of information across scales. First, features from raw MRI images are generated using feature extractors built on ResNet and MoblieNet architectures. This is followed by the Atrous Spatial Pyramid Pooling (ASPP) to produce spatial information at different scales to preserve more image context. High-level features from ASPP and initial low-level features are concatenated at the third stage and then passed to the fourth stage where spatial information is recovered via up-sampling to produce final image segmentation output into: i) background, ii) heart muscle, iii) blood and iv) scar areas. New models were compared with state-of-art models and manual quantification. Our models showed favorable performance in global segmentation and scar tissue detection relative to state-of-the-art work, including a four-fold better performance in matching scar pixels to contours produced by clinicians.
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基于AI的推荐系统已成功应用于许多域(例如,电子商务,提要排名)。医学专家认为,将这种方法纳入临床决策支持系统可能有助于减少医疗团队的错误并改善治疗过程中的患者结果(例如,创伤复苏,手术过程)。但是,已经进行了有限的研究来开发自动数据驱动的治疗决策支持。我们探索了构建治疗建议系统以提供下一分钟活动预测的可行性。该系统使用患者环境(例如人口统计和生命体征)和过程上下文(例如活动)来连续预测将在下一分钟进行的活动。我们在预先录制的创伤复苏数据集上评估了我们的系统,并对不同模型变体进行了消融研究。对于61种活动类型,最佳模型的平均F1得分为0.67。我们包括医疗团队的反馈并讨论未来的工作。
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磁共振成像(MRI)是中风成像的中心方式。它被用来接受患者的治疗决定,例如选择患者进行静脉溶栓或血管内治疗。随后在住院期间使用MRI来通过可视化梗塞核心大小和位置来预测结果。此外,它可以用来表征中风病因,例如(心脏) - 栓塞和非胚胎中风之间的区分。基于计算机的自动医疗图像处理越来越多地进入临床常规。缺血性中风病变分割(ISLE)挑战的先前迭代有助于生成鉴定急性和急性缺血性中风病变分割的基准方法。在这里,我们介绍了一个专家注册的多中心MRI数据集,以分割急性到亚急性中风病变。该数据集包括400个多供应商MRI案例,中风病变大小,数量和位置的可变性很高。它分为n = 250的训练数据集和n = 150的测试数据集。所有培训数据将公开可用。测试数据集将仅用于模型验证,并且不会向公众发布。该数据集是Isles 2022挑战的基础,目的是找到算法方法,以实现缺血性中风的稳健和准确分割算法的开发和基准测试。
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物理储存器计算(RC)是计算框架,其中使用模拟计算机类似的非线性物理系统来执行为数字计算机设计的机器学习算法,其可以提供用于预测可以使用非线性微分方程找到的时间相关量的高计算能力。在这里,我们建议一个RC系统,该RC系统将振荡气泡簇的声响应的非线性与水中的标准回声状态网络(ESN)算法很好地预测非线性和混沌时间序列。我们通过证明其预测eSN效率的混沌麦克玻璃时间序列的能力来计算拟议的RC系统的合理性。
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Designing experiments often requires balancing between learning about the true treatment effects and earning from allocating more samples to the superior treatment. While optimal algorithms for the Multi-Armed Bandit Problem (MABP) provide allocation policies that optimally balance learning and earning, they tend to be computationally expensive. The Gittins Index (GI) is a solution to the MABP that can simultaneously attain optimality and computationally efficiency goals, and it has been recently used in experiments with Bernoulli and Gaussian rewards. For the first time, we present a modification of the GI rule that can be used in experiments with exponentially-distributed rewards. We report its performance in simulated 2- armed and 3-armed experiments. Compared to traditional non-adaptive designs, our novel GI modified design shows operating characteristics comparable in learning (e.g. statistical power) but substantially better in earning (e.g. direct benefits). This illustrates the potential that designs using a GI approach to allocate participants have to improve participant benefits, increase efficiencies, and reduce experimental costs in adaptive multi-armed experiments with exponential rewards.
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Quadruped robots are currently used in industrial robotics as mechanical aid to automate several routine tasks. However, presently, the usage of such a robot in a domestic setting is still very much a part of the research. This paper discusses the understanding and virtual simulation of such a robot capable of detecting and understanding human emotions, generating its gait, and responding via sounds and expression on a screen. To this end, we use a combination of reinforcement learning and software engineering concepts to simulate a quadruped robot that can understand emotions, navigate through various terrains and detect sound sources, and respond to emotions using audio-visual feedback. This paper aims to establish the framework of simulating a quadruped robot that is emotionally intelligent and can primarily respond to audio-visual stimuli using motor or audio response. The emotion detection from the speech was not as performant as ERANNs or Zeta Policy learning, still managing an accuracy of 63.5%. The video emotion detection system produced results that are almost at par with the state of the art, with an accuracy of 99.66%. Due to its "on-policy" learning process, the PPO algorithm was extremely rapid to learn, allowing the simulated dog to demonstrate a remarkably seamless gait across the different cadences and variations. This enabled the quadruped robot to respond to generated stimuli, allowing us to conclude that it functions as predicted and satisfies the aim of this work.
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Real-world robotic grasping can be done robustly if a complete 3D Point Cloud Data (PCD) of an object is available. However, in practice, PCDs are often incomplete when objects are viewed from few and sparse viewpoints before the grasping action, leading to the generation of wrong or inaccurate grasp poses. We propose a novel grasping strategy, named 3DSGrasp, that predicts the missing geometry from the partial PCD to produce reliable grasp poses. Our proposed PCD completion network is a Transformer-based encoder-decoder network with an Offset-Attention layer. Our network is inherently invariant to the object pose and point's permutation, which generates PCDs that are geometrically consistent and completed properly. Experiments on a wide range of partial PCD show that 3DSGrasp outperforms the best state-of-the-art method on PCD completion tasks and largely improves the grasping success rate in real-world scenarios. The code and dataset will be made available upon acceptance.
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When robots learn reward functions using high capacity models that take raw state directly as input, they need to both learn a representation for what matters in the task -- the task ``features" -- as well as how to combine these features into a single objective. If they try to do both at once from input designed to teach the full reward function, it is easy to end up with a representation that contains spurious correlations in the data, which fails to generalize to new settings. Instead, our ultimate goal is to enable robots to identify and isolate the causal features that people actually care about and use when they represent states and behavior. Our idea is that we can tune into this representation by asking users what behaviors they consider similar: behaviors will be similar if the features that matter are similar, even if low-level behavior is different; conversely, behaviors will be different if even one of the features that matter differs. This, in turn, is what enables the robot to disambiguate between what needs to go into the representation versus what is spurious, as well as what aspects of behavior can be compressed together versus not. The notion of learning representations based on similarity has a nice parallel in contrastive learning, a self-supervised representation learning technique that maps visually similar data points to similar embeddings, where similarity is defined by a designer through data augmentation heuristics. By contrast, in order to learn the representations that people use, so we can learn their preferences and objectives, we use their definition of similarity. In simulation as well as in a user study, we show that learning through such similarity queries leads to representations that, while far from perfect, are indeed more generalizable than self-supervised and task-input alternatives.
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and widely used information measurement metric, particularly popularized for SSVEP- based Brain-Computer (BCI) interfaces. By combining speed and accuracy into a single-valued parameter, this metric aids in the evaluation and comparison of various target identification algorithms across different BCI communities. To accurately depict performance and inspire an end-to-end design for futuristic BCI designs, a more thorough examination and definition of ITR is therefore required. We model the symbiotic communication medium, hosted by the retinogeniculate visual pathway, as a discrete memoryless channel and use the modified capacity expressions to redefine the ITR. We use graph theory to characterize the relationship between the asymmetry of the transition statistics and the ITR gain with the new definition, leading to potential bounds on data rate performance. On two well-known SSVEP datasets, we compared two cutting-edge target identification methods. Results indicate that the induced DM channel asymmetry has a greater impact on the actual perceived ITR than the change in input distribution. Moreover, it is demonstrated that the ITR gain under the new definition is inversely correlated with the asymmetry in the channel transition statistics. Individual input customizations are further shown to yield perceived ITR performance improvements. An algorithm is proposed to find the capacity of binary classification and further discussions are given to extend such results to ensemble techniques.We anticipate that the results of our study will contribute to the characterization of the highly dynamic BCI channel capacities, performance thresholds, and improved BCI stimulus designs for a tighter symbiosis between the human brain and computer systems while enhancing the efficiency of the underlying communication resources.
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