Handbook of Vascular Biometrics

This open access handbook provides the first comprehensive overview of biometrics exploiting the shape of human blood vessels for biometric recognition, i.e. vascular biometrics, including finger vein recognition, hand/palm vein recognition, retina recognition, and sclera recognition. After an introductory chapter summarizing the state of the art in and availability of commercial systems and open datasets/open source software, individual chapters focus on specific aspects of one of the biometric modalities, including questions of usability, security, and privacy. The book features contributions from both academia and major industrial manufacturers

Single-Sample Finger Vein Recognition via Competitive and Progressive Sparse Representation

As an emerging biometric technology, finger vein recognition has attracted much attention in recent years. However, single-sample recognition is a practical and longstanding challenge in this field, referring to only one finger vein image per class in the training set. In single-sample finger vein recognition, the illumination variations under low contrast and the lack of information of intra-class variations severely affect the recognition performance. Despite of its high robustness against noise and illumination variations, sparse representation has rarely been explored for single-sample finger vein recognition. Therefore, in this paper, we focus on developing a new approach called Progressive Sparse Representation Classification (PSRC) to address the challenging issue of single-sample finger vein recognition. Firstly, as residual may become too large under the scenario of single-sample finger vein recognition, we propose a progressive strategy for representation refinement of SRC. Secondly, to adaptively optimize progressions, a progressive index called Max Energy Residual Index (MERI) is defined as the guidance. Furthermore, we extend PSRC to bimodal biometrics and propose a Competitive PSRC (C-PSRC) fusion approach. The C-PSRC creates more discriminative fused sample and fusion dictionary by comparing residual errors of different modalities. By comparing with several state-of-the-art methods on three finger vein benchmarks, the superiority of the proposed PSRC and C-PSRC is clearly demonstrated

Biometric Systems

Because of the accelerating progress in biometrics research and the latest nation-state threats to security, this book's publication is not only timely but also much needed. This volume contains seventeen peer-reviewed chapters reporting the state of the art in biometrics research: security issues, signature verification, fingerprint identification, wrist vascular biometrics, ear detection, face detection and identification (including a new survey of face recognition), person re-identification, electrocardiogram (ECT) recognition, and several multi-modal systems. This book will be a valuable resource for graduate students, engineers, and researchers interested in understanding and investigating this important field of study

Biometrics

Biometrics uses methods for unique recognition of humans based upon one or more intrinsic physical or behavioral traits. In computer science, particularly, biometrics is used as a form of identity access management and access control. It is also used to identify individuals in groups that are under surveillance. The book consists of 13 chapters, each focusing on a certain aspect of the problem. The book chapters are divided into three sections: physical biometrics, behavioral biometrics and medical biometrics. The key objective of the book is to provide comprehensive reference and text on human authentication and people identity verification from both physiological, behavioural and other points of view. It aims to publish new insights into current innovations in computer systems and technology for biometrics development and its applications. The book was reviewed by the editor Dr. Jucheng Yang, and many of the guest editors, such as Dr. Girija Chetty, Dr. Norman Poh, Dr. Loris Nanni, Dr. Jianjiang Feng, Dr. Dongsun Park, Dr. Sook Yoon and so on, who also made a significant contribution to the book

Diving into the depth of primary motor cortex: a high-resolution investigation of the motor system using 7Tesla fMRI

Dissertação para a obtenção do Grau de Mestre em Engenharia BiomédicaHuman behaviour is grounded in our ability to perform complex tasks. While human motor function has been studied for over a century the cortical processes underlying motor behaviour are still under debate. Central to the execution of action is the primary motor cortex (M1), which has previously been considered to be responsible for the execution of movements planned in the premotor cortex, yet recent studies point to more complex roles for M1 in orchestrating motor-related information. The purpose of this project is to study the functional properties of primary motor cortex using ultra-high fMRI. The spatial resolution made possible by using a high field magnet allows us to investigate novel questions such as the existence of cortical columns, the functional organization pattern for single fingers and functional involvement of M1 in motor imagery and observation. Thirteen young healthy subjects participated in this study. Functional and anatomical high resolution images were acquired. Four functional scans were acquired for the different tasks: motor execution; motor imagery; movement observation and rest. The paradigm used was a randomized finger tapping. The images analysis was performed with the Brainvoyager QX program. Using the novel high resolution cortical grid sampling analysis tools, different cortical laminas of human M1 were examined. Our results reveal a distributed pattern (intermingled with somatotopic “hot spots”) for single fingers activity in M1. Furthermore we show novel evidence of columnar structures in M1 and show that non motor tasks such as motor imagery and action observation also activate this region. We conclude that the primary motor cortex has much more un-expected complex roles regarding the processing of movement related information, not only due to their involvement in tasks that do not imply muscle movement, but also due to their intriguing organization pattern

Hand Coverage

Hand and finger soft tissue defects have always represented a surgical challenge at any accident and emergency department. Techniques may vary from just direct closure of the wound to free tissue transfer. Knowledge of the main locoregional hand flaps is paramount to solve most of the soft tissue defects at this level. Flaps vary depending on their blood supply and design. Their vascularity might be at random, they can be pedicled with anterograde or reversed flow or they can rely on simple or complex free tissue transfer whose blood flow depends on vascular anastomosis. This article reviews all the main soft tissue local or locoregional reconstructive techniques for hands and fingers

How does handwriting of letters affect mirror-image discrimination?

We explored whether training motor actions that match letter motor representations, supposedly supported by the dorsal visual stream, would contribute to mirror-image discrimination in tasks supported by the ventral visual stream, especially of letters for which orientation is the only feature that can assist discrimination, i.e., reversible letters. Two groups of preliterate children trained motor actions during 20, 20-min daily sessions, in tablet games developed specifically for this study following human-computer interaction principles. Six children played the draw game, tracing and copying letters, and five children played the contact game (the control game) by moving the letters from an initial to a target point. Two reversible letters (d; p), two non-reversible (e; k), and two symmetrical letters (o; x) were used in both games. To evaluate the impact of motor training on orientation processing, children performed independent tasks before and after the training: a four-alternative forced-choice task with letters, and same-different matching tasks with letters and geometric shapes. Children’s performance in the games suggests that letter motor representations have emerged but only when the trained motor actions matched the letter shape (i.e., in the draw game) and they were more important for reversible than for non-reversible or symmetrical letters. The difficulty in mirror-image discrimination found in the four-alternative forced-choice task provide an original contribution showing that this difficulty is not specifically due to the working memory demands of the tasks in which it occurs. The results in the same-different tasks suggest that children became more sensitive to plane-rotation contrasts because in both games they had contact with letters differing by that contrast (i.e., d-p). Finally, when we compared both groups’ performance in the independent tasks before and after the training, no significant differences were found. Therefore we could not confirm, or refute, the importance of training motor actions that match letter motor representations on mirror-image discrimination.Investigámos se o treino de acções motoras correspondentes à representação motora de letras, supostamente suportado pela via visual dorsal, contribui para a discriminação de imagens em espelho em tarefas suportadas pela via visual ventral, em particular de letras cuja orientação é a única característica que permite a sua discriminação, i.e., letras reversíveis. Dois grupos de crianças pré-letradas treinaram acções motoras com letras durante 20 sessões diárias de 20 min cada, em jogos de tablete desenvolvidos especificamente para este estudo segundo princípios da interacção humano-computador. Seis crianças treinaram no jogo draw, traçando e copiando as letras, e cinco crianças no jogo contact (jogo de controle) movimentado as letras de um ponto para outro. Utilizaram-se duas letras reversíveis (d; p), duas não-reversíveis (e; k) e duas simétricas (o; x). Para avaliar o impacto do treino no processamento da orientação, as crianças realizaram, antes e depois do treino, tarefas independentes dos jogos: uma tarefa de escolha forçada com letras, e tarefas de julgamento igual-diferente com letras e figuras geométricas. A evolução do desempenho das crianças no treino sugere que só o treino de acções motoras correspondentes à forma da letra, no jogo draw, conduziu à emergência de representações motoras das letras, que foram mais importantes para o desempenho com letras reversíveis do que com letras não-reversíveis e simétricas. Os resultados na tarefa de escolha forçada deram um contributo original para o estudo da discriminação de imagens em espelho, ao mostrar que esta dificuldade não é devida em particular às exigências de memória de trabalho da tarefa em que ocorre. Os resultados nas tarefas igual-diferente sugerem que as crianças após o treino aumentaram a sensibilidade aos contrastes de orientação rotação-plana devido ao contacto nos dois jogos com esse contraste (i.e., contacto com as letras d e p). Finalmente, a comparação do desempenho dos dois grupos nas tarefas independentes antes e após o treino, não revelou diferenças significativas. Não foi assim possível confirmar, ou rejeitar, a importância do treino motor que corresponde à representação motora das letras na discriminação imagens em espelho