Evaluation of a Vein Biometric Recognition System on an Ordinary Smartphone

Nowadays, biometrics based on vein patterns as a trait is a promising technique. Vein patterns satisfy universality, distinctiveness, permanence, performance, and protection against circumvention. However, collectability and acceptability are not completely satisfied. These two properties are directly related to acquisition methods. The acquisition of vein images is usually based on the absorption of near-infrared (NIR) light by the hemoglobin inside the veins, which is higher than in the surrounding tissues. Typically, specific devices are designed to improve the quality of the vein images. However, such devices increase collectability costs and reduce acceptability. This paper focuses on using commercial smartphones with ordinary cameras as potential devices to improve collectability and acceptability. In particular, we use smartphone applications (apps), mainly employed for medical purposes, to acquire images with the smartphone camera and improve the contrast of superficial veins, as if using infrared LEDs. A recognition system has been developed that employs the free IRVeinViewer App to acquire images from wrists and dorsal hands and a feature extraction algorithm based on SIFT (scale-invariant feature transform) with adequate pre- and post-processing stages. The recognition performance has been evaluated with a database composed of 1000 vein images associated to five samples from 20 wrists and 20 dorsal hands, acquired at different times of day, from people of different ages and genders, under five different environmental conditions: day outdoor, indoor with natural light, indoor with natural light and dark homogeneous background, indoor with artificial light, and darkness. The variability of the images acquired in different sessions and under different ambient conditions has a large influence on the recognition rates, such that our results are similar to other systems from the literature that employ specific smartphones and additional light sources. Since reported quality assessment algorithms do not help to reject poorly acquired images, we have evaluated a solution at enrollment and matching that acquires several images subsequently, computes their similarity, and accepts only the samples whose similarity is greater than a threshold. This improves the recognition, and it is practical since our implemented system in Android works in real-time and the usability of the acquisition app is high.MCIN/AEI/ 10.13039/50110001103 Grant PDC2021-121589-I00Fondo Europeo de Desarrollo Regional (FEDER) and Consejería de Transformación Económica, Industria, Conocimiento y Universidades de la Junta de Andalucía Grant US-126514

Generating and analyzing synthetic finger vein images

Abstract: The finger-vein biometric offers higher degree of security, personal privacy and strong anti-spoofing capabilities than most other biometric modalities employed today. Emerging privacy concerns with the database acquisition and lack of availability of large scale finger-vein database have posed challenges in exploring this technology for large scale applications. This paper details the first such attempt to synthesize finger-vein images and presents analysis of synthesized images for the biometrics authentication. We generate a database of 50,000 finger vein images, corresponding to 5000 different subjects, with 10 different synthesized finger-vein images from each of the subject. We use tractable probability models to compare synthesized finger-vein images with the real finger- vein images for their image variability. This paper also presents matching accuracy using the synthesized finger-vein database from 5000 different subjects, using 225000 genuine and 1249750000 impostor matching scores, which suggests significant promises from this finger-vein biometric modality for large scale biometrics applications

Estudo de retalhos venosos arterializados no modelo experimental de rato wistar e no cadáver humano

RESUMO:Introdução: Os retalhos de perfusão não convencionais (UPFs) são opções reconstrutivas caracterizadas por serem perfundidas exclusivamente por veias. Nos UPFs, pelo menos uma das veias aferentes do retalho é anastomosada a um vaso de alimentação. Normalmente, este vaso de alimentação é uma artéria, e o UPF é chamado de retalho venoso arterializado (AVF). Se o vaso de alimentação for uma veia, o UPF é chamado de retalho venoso (VF). O fluxo de sangue é assegurado na maioria dos casos pela continuidade de uma ou mais veias do UPF com veias vizinhas. Embora os UPFs apresentem várias vantagens potenciais em relação aos retalhos de perfusão convencionais (CFs), raramente são mencionados na literatura, devido às altas taxas de necrose relatadas, particularmente na presença de infeção, e devido a uma má compreensão de seus mecanismos fisiológicos subjacentes. Métodos: Realizámos revisões sistemáticas e metanálises sobre o uso clínico e experimental dos UPFs. Seguidamente, estudamos detalhadamente a anatomia vascular do aspecto ventrolateral do abdômen do rato. Com esse conhecimento, melhoramos o modelo de um retalho convencional colhido na região epigástrica. Posteriormente, desenvolvemos um modelo otimizado de AVF no abdómen do rato. Avaliamos o efeito de transfectar este modelo otimizado com genes de beta defensina humana (BD-2 e BD-3) para aumentar a sobrevivência do retalho na presença de infecção por Pseudomonas aeruginosa e de um corpo estranho. Além disso, comparamos a eficácia dos retalhos neurovenosos arterializados (ANVFs) com outros condutos nervosos com o intuito de reconstruir um hiato de 10 mm no nervo mediano do rato num ambiente de isquémia local. Seguidamente, realizamos estudos cadavéricos para avaliar os aspetos pertinentes da anatomia e histologia das regiões anatômicas comumente usadas para colher UPFs. Finalmente, usamos algumas das informações coletadas para tratar um adolescente com um defeito do pedículo vásculo-nervoso ulnar ao nível do antebraço. Resultados: Estimámos uma taxa de sobrevivência global de UPFs de 89,5% no contexto clínico e de 90,8% em condições experimentais. Clinicamente, houve uma correlação positiva entre a taxa de infeção pós-operatória e a necessidade de um novo retalho (coeficiente de Pearson 0,405; p = 0,001). O fornecimento de sangue ao tegumento abdominal do rato era sobretudo dependente dos vasos axiais, contrastando com o que acontece no Homem. Válvulas venosas foram claramente observadas nesta região. O retalho convencional epigástrico livre e o AVF otimizada homólogo apresentaram taxas de sobrevivência de quase 100% e 76,86 ± 13,67%, respectivamente. Transfectando-se o modelo de AVF com BD-2 e BD-3, observou-se aumento da sobrevivência do retalho e diminuição da formação de biofilmes. Os ANVFs produziram uma recuperação mais completa e mais rápida do que os enxertos nervosos, para a maioria dos parâmetros utilizados para avaliar a regeneração nervosa. Estudos anatómicos e histológicos revelaram que as veias subcutâneas de maiores dimensões encontravam-se envolvidas por desdobramentos da fáscia superficial. Além disso, as veias encontravam-se em profundidades diferentes, estando as maiores colocadas profundamente e as mais pequenas localizadas mais superficialmente. Finalmente, observou-se que os nervos cutâneos superficiais, rotineiramente utilizados como enxertos de nervos autólogos, estavam mais próximos das veias superficiais do que das artérias e respetivas veias comitantes com calibre significativo. Os UPFs podem ser adaptados a defeitos específicos, incluindo pele, tecido celular subcutâneo, tendões, nervos, fáscia muscular e / ou osso em combinações variáveis. O uso de um ANVF no referido adolescente permitiu a reconstrução dos defeitos arterial e nervoso com sucesso. Conclusão: Apesar de muitas questões continuarem por responder em relação à fisiologia, otimização e indicações dos UPFs, parece haver evidência suficiente para apoiar seu uso no âmbito da reconstrução tegumentar e nervosa.ABSTRACT: Introduction: Unconventional perfusion flaps (UPFs) are reconstructive options characterized by being perfused exclusively by veins. In UPFs at least one of the afferent veins of the flap is anastomosed to a feeding vessel. Usually, this feeding vessel is an artery, and the UPF is called an arterialized venous flap (AVF). If the feeding vessel is a vein, the UPF is called a venous flap (VF). The efflux of blood is ensured in most cases by the continuity of one or more of the UPF’s veins with neighboring veins. Although UPFs present several potential advantages relatively to conventional perfusion flaps, they have rarely been mentioned in the clinical literature, due to reported high necrosis rates, particularly in the presence of infection, and due to a poor understanding of their underlying physiologic mechanisms. Methods: We performed systematic reviews and meta-analyses on the clinical and experimental used of UPFs. Followingly, we studied in detail the vascular anatomy of the ventrolateral aspect of the rat’s abdomen. Using this knowledge, we improved a model of a conventional flap (CF) harvested from the epigastric region of the fat. Subsequently, we developed an optimized a model of AVF in the abdomen of the rat. We, then, evaluated the effect of transfecting the optimized model with human beta defensin genes (BD-2 and BD-3) to increase flap survival in the presence of Pseudomonas aeruginosa infection and of a foreign body. Moreover, we compared the efficacy of arterialized neurovenous flaps (ANVFs) with other nerve conduits to reconstruct a 10-mm-long median nerve gap in an ischemic environment in a rat model. Followingly, we performed cadaveric studies to assess pertinent aspects of the anatomy and histology of anatomical regions commonly used to harvest UPFs. Finally, we used some of the information gathered to treat a teenager with an ulnar artery and nerve composite defect at the forearm level. Results: We estimated an overall survival rate of UPFs of 89.5% in the clinical context and of 90.8% in the experimetal setting. Clinically, there was a positive correlation between the rate of postoperative infection and the need of a new flap (Pearson coefficient 0.405; p=0.001). Blood supply to the abdominal integument of the rat was more dependent on axial vessels, comparatively to humans. Venous valves were clearly observed in this region. The free epigastric CF and the homologous optimized AVF presented survival rates of nearly 100%, and 76.86 ± 13.67%, respectively. Transfecting the AVF model with BD-2 and BD-3 increased flap survival, and decreased biofilm formation. ANVFs produced more complete and faster recovery than nerve grafts, for most of the parameters used to assess nerve regeneration. Anatomical and histological studies revealed that large subcutaneous veins were surrounded by doublings of the superficial fascia. Moreover, veins were placed at different depths, with the largest ones being deeply placed and the smallest more superficially placed. Finally, it was noted that superficial cutaneous nerves, routinely used as autologous nerve grafts, were closer to sizeable superficial veins than to arteries and respective comitante veins of significant caliber. UPFs could be tailored to specific defects by including either skin, subcutaneous tissue, tendons, nerves, muscle fascia and/or bone in variable combinations. The used of an ANVF in a teenager allowed the successful reconstruction of both the arterial and nerve defects. Conclusion: Although many question remain to be answered relatively to UPFs physiology, optimization, and indications, there seems to be enough evidence to support their use in the realm of integumentary and nerve reconstruction.RÉSUMÉ: Introduction: Les lambeaux de perfusion non conventionnels (UPF) sont des options de reconstructives caractérisées par une perfusion exclusive pour le veines. Dans les UPF, il ya au moins une des veines afférentes du Lambeau qui est anastomosée à un vase d'alimentation. Habituellement, ce vaisseau d'alimentation est une artère, et l'UPF s'appelle un lambeau veineux arterialisé (AVF). Si le vaisseau est une veine, l'UPF s'appelle un lambeau veineux (VF). L'effusion de sang est assurée dans la plupart des cas par la continuité d'une ou plusieurs veines de l'UPF avec des veines voisines. Bien que les UPF présentent plusieurs avantages potentiels par rapport aux lambeaux de perfusion conventionnels, ils ont rarement été mentionnés dans la littérature clinique, en raison des taux élevés de nécrose reportés, en particulier en présence d'une infection, et en raison d'une mauvaise compréhension de leurs mécanismes physiologiques. Méthodes: Nous avons procédé à deux analyses systématiques et méta-analyses sur l'utilisation clinique et expérimentale des UPFs. Nous avons étudié en détail l'anatomie vasculaire de l'aspect ventral de l'abdomen du rat. À l'aide de cette connaissance, nous avons amélioré un modèle de lambeau conventionnel (CF) récolté dans la région épigastrique de l’abdomen. Par la suite, nous avons développé un modèle optimisé d'AVF dans l'abdomen du rat. Nous avons ensuite évalué l'effet de la transfection du modèle optimisé avec les gènes de la beta-defensine humaine (BD-2 et BD-3) pour augmenter la survie des lambeaux en présence d'une infection pour Pseudomonas aeruginosa et d'un corps étranger. Nous avons aussi comparé l'efficacité des lambeaux neurovenous arterialisés (ANVF) avec d'autres conduits nerveux pour reconstruire un hiatus nerveux de le nerf médian de 10 mm de longueur dans un environnement ischémique dans le modèle de le rat Wistar. Par la suite, nous avons effectué des études cadavériques pour évaluer les aspects pertinents de l'anatomie et de l'histologie des régions anatomiques couramment utilisées pour récolter des UPFs. Enfin, nous avons utilisé une partie des informations recueillies pour traiter un adolescent souffrant d'un défaut composite de l’artère ulnaire e de le nerf ulnaire au niveau de l'avant-bras. Résultats: Nous avons estimé un taux global de survie des UPF de 89,5% dans le contexte clinique et de 90,8% dans le contexte expérimental. Cliniquement, il y avait une corrélation positive entre le taux d'infection postopératoire et la besoin d'un nouveau lambeau (coefficient de Pearson 0,405; p = 0,001). L'approvisionnement en sang du tégument abdominal du rat dépendait davantage des vaisseaux axiaux, comparativement aux humains. Les valves veineuses ont été clairement observées dans cette région. Le lambeau épigastrique conventionnel livre et l'AVF homologue optimisée ont présenté des taux de survie de près de 100% et 76,86 ± 13,67%, respectivement. Transféction de le modèle AVF optimisée avec BD-2 et BD-3 augmenté la survie du lambeau et la formation de biofilm a été diminuée. Les ANVF ont produit une récupération plus complète et plus rapide que les greffes nerveuses, pour la plupart des paramètres utilisés pour évaluer la régénération nerveuse. Des études anatomiques et histologiques ont révélé que les grandes veines sous-cutanées étaient entourées de doublures du fascia superficiel. De plus, les veines ont été placées à différentes profondeurs, les plus grandes étant profondément placées et les plus petites placées plus superficiellement. Enfin, il a été noté que les nerfs cutanés superficiels, habituellement utilisés comme greffes autologues, étaient plus proches des veines superficielles importantes que des artères et des veines comitantes respectives de calibre significatif. Les UPF pourraient être adaptés à des défauts spécifiques en incluant la peau, le tissu sous-cutané, les tendons, les nerfs, le fascia musculaire et / ou l'os dans des combinaisons variables. L'utilisation d'un ANVF chez un adolescent a permis la reconstruction réussie des défauts artériels et nerveux. Conclusion: Bien que beaucoup de questions restent à répondre par rapport à la physiologie, à l'optimisation et aux indications de l'UPF, il semble y avoir suffisamment des preuves scientifiques pour favoriser leur utilisation dans le domaine de la reconstruction de l’integument et des les nerfs

Real-Time Superficial Vein Imaging System for Observing Abnormalities on Vascular Structures

Circulatory system abnormalities might be an indicator of diseases or tissue damage. Early detection of vascular abnormalities might have an important role during treatment and also raise the patient's awarenes. Current detection methods for vascular imaging are high-cost, invasive, and mostly radiation-based. In this study, a low-cost and portable microcomputer-based tool has been developed as a near-infrared (NIR) superficial vascular imaging device. The device uses NIR light-emitting diode (LED) light at 850 nm along with other electronic and optical components. It operates as a non-contact and safe infrared (IR) imaging method in real-time. Image and video analysis are carried out using OpenCV (Open-Source Computer Vision), a library of programming functions mainly used in computer vision. Various tests were carried out to optimize the imaging system and set up a suitable external environment. To test the performance of the device, the images taken from three diabetic volunteers, who are expected to have abnormalities in the vascular structure due to the possibility of deformation caused by high glucose levels in the blood, were compared with the images taken from two non-diabetic volunteers. As a result, tortuosity was observed successfully in the superficial vascular structures, where the results need to be interpreted by the medical experts in the field to understand the underlying reasons. Although this study is an engineering study and does not have an intention to diagnose any diseases, the developed system here might assist healthcare personnel in early diagnosis and treatment follow-up for vascular structures and may enable further opportunities

Ultrasonographic assessment of normal jugular veins in Standardbred horses

Ultrasonography (US) is the recommended imaging technique to evaluate jugular veins. This prospective randomized clinical study was designed to collect a series of B-mode US measurements of manually distended jugular veins in healthy Italian Standardbreds and to find possible correlations between ultrasound measurements and animal morphometric characteristics. Forty-two horses, eight males and 34 females (range 3-22 years; bodyweight 494.4 ± 41.7 kg), were included in the study. The diameters and wall thicknesses of both jugular veins were measured at three different sites of the neck. The differences in ultrasound measurements based on scans, age, gender, side, and site of the neck were evaluated by ANOVA or by the Kruskal-Wallis test. The effects of the morphometric measures on each ultrasound parameter were evaluated by MANOVA (P < 0.05)

Ultrasonographic assessment of normal jugular veins in Standardbred horses

Ultrasonography (US) is the recommended imaging technique to evaluate jugular veins. This prospective randomized clinical study was designed to collect a series of B-mode US measurements of manually distended jugular veins in healthy Italian Standardbreds and to find possible correlations between ultrasound measurements and animal morphometric characteristics. Forty-two horses, eight males and 34 females (range 3-22\u2009years; bodyweight 494.4\u2009\ub1\u200941.7\u2009kg), were included in the study. The diameters and wall thicknesses of both jugular veins were measured at three different sites of the neck. The differences in ultrasound measurements based on scans, age, gender, side, and site of the neck were evaluated by ANOVA or by the Kruskal-Wallis test. The effects of the morphometric measures on each ultrasound parameter were evaluated by MANOVA (P\u2009&lt;\u20090.05)