Autonomous robotic intracardiac catheter navigation using haptic vision

International audienceWhile all minimally invasive procedures involve navigating from a small incision in the skin to the site of the intervention, it has not been previously demonstrated how this can be done 10 autonomously. To show that autonomous navigation is possible, we investigated it in the hardest place to do it-inside the beating heart. We created a robotic catheter that can navigate through the blood-filled heart using wall-following algorithms inspired by positively thigmotactic animals. The catheter employs haptic vision, a hybrid sense using imaging for both touch-based surface identification and force sensing, to accomplish wall following inside the blood-filled heart. 15 Through in vivo animal experiments, we demonstrate that the performance of an autonomously-controlled robotic catheter rivals that of an experienced clinician. Autonomous navigation is a fundamental capability on which more sophisticated levels of autonomy can be built, e.g., to perform a procedure. Similar to the role of automation in fighter aircraft, such capabilities can free the clinician to focus on the most critical aspects of the procedure while providing precise and 20 repeatable tool motions independent of operator experience and fatigue

PerMallows: An R Package for Mallows and Generalized Mallows Models

In this paper we present the R package PerMallows, which is a complete toolbox to work with permutations, distances and some of the most popular probability models for permutations: Mallows and the Generalized Mallows models. The Mallows model is an exponential location model, considered as analogous to the Gaussian distribution. It is based on the definition of a distance between permutations. The Generalized Mallows model is its best-known extension. The package includes functions for making inference, sampling and learning such distributions. The distances considered in PerMallows are Kendall's τ , Cayley, Hamming and Ulam

Is there anything new to say about SIFT matching?

SIFT is a classical hand-crafted, histogram-based descriptor that has deeply influenced research on image matching for more than a decade. In this paper, a critical review of the aspects that affect SIFT matching performance is carried out, and novel descriptor design strategies are introduced and individually evaluated. These encompass quantization, binarization and hierarchical cascade filtering as means to reduce data storage and increase matching efficiency, with no significant loss of accuracy. An original contextual matching strategy based on a symmetrical variant of the usual nearest-neighbor ratio is discussed as well, that can increase the discriminative power of any descriptor. The paper then undertakes a comprehensive experimental evaluation of state-of-the-art hand-crafted and data-driven descriptors, also including the most recent deep descriptors. Comparisons are carried out according to several performance parameters, among which accuracy and space-time efficiency. Results are provided for both planar and non-planar scenes, the latter being evaluated with a new benchmark based on the concept of approximated patch overlap. Experimental evidence shows that, despite their age, SIFT and other hand-crafted descriptors, once enhanced through the proposed strategies, are ready to meet the future image matching challenges. We also believe that the lessons learned from this work will inspire the design of better hand-crafted and data-driven descriptors

Multi-Modal Ocular Recognition in presence of occlusion in Mobile Devices

Title from PDF of title page viewed September 18, 2019Dissertation advisor: Reza DerakhshaniVitaIncludes bibliographical references (pages 128-144)Thesis (Ph.D.)--School of Computing and Engineering. University of Missouri--Kansas City, 2018The existence eyeglasses in human faces cause real challenges for ocular, facial, and soft-based (such as eyebrows) biometric recognition due to glasses reflection, shadow, and frame occlusion. In this regard, two operations (eyeglasses detection and eyeglasses segmentation) have been proposed to mitigate the effect of occlusion using eyeglasses. Eyeglasses detection is an important initial step towards eyeglass segmentation. Three schemes of eye glasses detection have been proposed which are non-learning-based, learning-based, and deep learning-based schemes. The non-learning scheme of eyeglasses detection which consists of cascaded filters achieved an overall accuracy of 99.0% for VI SOB and 97.9% for FERET datasets. The learning-based scheme of eyeglass detection consisting of extracting Local Binary Pattern (LBP), Histogram of Gradients (HOG) and fusing them together, then applying classifiers (such as Support Vector Machine (SVM), Multi-Layer Perceptron (MLP), and Linear Discriminant Analysis (LDA)), and fusing the output of these classifiers. The latter obtained a best overall accuracy of about 99.3% on FERET and 100% on VISOB dataset. Besides, the deep learning-based scheme of eye glasses detection showed a comparative study for eyeglasses frame detection using different Convolutional Neural Network (CNN) structures that are applied to Frame Bridge region and extended ocular region. The best CNN model obtained an overall accuracy of 99.96% for ROI consisting of Frame Bridge. Moreover, two schemes of eyeglasses segmentation have been introduced. The first segmentation scheme was cascaded convolutional Neural Network (CNN). This scheme consists of cascaded CNN’s for eyeglasses detection, weight generation, and glasses segmentation, followed by mathematical and binarization operations. The scheme showed a 100% eyeglasses detection and 91% segmentation accuracy by our proposed approach. Also, the second segmentation scheme was the convolutional de-convolutional network. This CNN model has been implemented with main convolutional layers, de-convolutional layers, and one custom (lamda) layer. This scheme achieved better segmentation results of 97% segmentation accuracy over the cascaded approach. Furthermore, two soft biometric re-identification schemes have been introduced with eyeglasses mitigation. The first scheme was eyebrows-based user authentication consists of local, global, deep feature extraction with learning-based matching. The best result of 0.63% EER using score level fusion of handcraft descriptors (HOG, and GIST) with the deep VGG16 descriptor for eyebrow-based user authentication. The second scheme was eyeglass-based user authentication which consisting of eyeglasses segmentation, morphological cleanup, features extraction, and learning-based matching. The best result of 3.44% EER using score level fusion of handcraft descriptors (HOG, and GIST) with the deep VGG16 descriptor for eyeglasses-based user authentication. Also, an EER enhancement of 2.51% for indoor vs. outdoor (In: Out) light set tings was achieved for eyebrow-based authentication after eyeglasses segmentation and removal using Convolutional-Deconvolutional approach followed by in-painting.Introduction -- Background in machine learning and computer vision -- Eyeglasses detection and segmentation -- User authentication using soft-biometric -- Conclusion and future work -- Appendi

Biometric antispoofing on mobile devices

In the present chapter, after a thorough review of state-of-the-art in biometric antispoofing, we present a software-based spoof detection prototype for mobile devices, named MoBio_LivDet (Mobile Biometric Liveness Detection) that can be used in multiple biometric systems. MoBio_LivDet analyzes local features and global structures of face, iris and fingerprint biometric images using a set of low-level feature descriptors and decision-level fusion. In particular, we propose to use image descriptor classification algorithms Locally Uniform Comparison Image Descriptor (LUCID) [15], CENsus TRansform hISTogram (CENTRIST) [16] and Patterns of Oriented Edge Magnitudes (POEM) [17] for face, iris and fingerprint spoof detection. The proposed system allows user to choose “Security Level” (SL) against spoofing, between “low, " “medium” and “high.” Depending on SL, the system selects unitdescriptor or multidescriptors-fusion-based liveness detection. These descriptors are computationally inexpensive, fast and novel approach to real-time image description, which are desirable requisites for mobile processors. Experiments on publicly available data sets containing several real and spoofed faces, irises and fingerprints show promising results. Chapter Contents: • 15.1 Introduction • 15.2 Biometric antispoofing • 15.2.1 State-of-the-art in face antispoofing • 15.2.2 State-of-the-art in fingerprint antispoofing • 15.2.3 State-of-the-art in iris antispoofing • 15.3 Case study: MoBio_LivDet system • 15.3.1 Experiments • 15.4 Research opportunities • 15.4.1 Mobile liveness detection • 15.4.2 Mobile biometric spoofing databases • 15.4.3 Generalization to unknown attacks • 15.4.4 Randomizing input biometric data • 15.4.5 Fusion of biometric system and countermeasures • 15.5 Conclusion • References