Image processing techniques for mixed reality and biometry

2013 - 2014This thesis work is focused on two applicative fields of image processing research, which, for different reasons, have become particularly active in the last decade: Mixed Reality and Biometry. Though the image processing techniques involved in these two research areas are often different, they share the key objective of recognizing salient features typically captured through imaging devices. Enabling technologies for augmented/mixed reality have been improved and refined throughout the last years and more recently they seems to have finally passed the demo stage to becoming ready for practical industrial and commercial applications. To this regard, a crucial role will likely be played by the new generation of smartphones and tablets, equipped with an arsenal of sensors connections and enough processing power for becoming the most portable and affordable AR platform ever. Within this context, techniques like gesture recognition by means of simple, light and robust capturing hardware and advanced computer vision techniques may play an important role in providing a natural and robust way to control software applications and to enhance onthe- field operational capabilities. The research described in this thesis is targeted toward advanced visualization and interaction strategies aimed to improve the operative range and robustness of mixed reality applications, particularly for demanding industrial environments... [edited by Author]XIII n.s

Analgesic effectiveness and tolerability of oral oxycodone/naloxone and pregabalin in patients with lung cancer and neuropathic pain. An observational analysis

INTRODUCTION: Cancer-related pain has a severe negative impact on quality of life. Combination analgesic therapy with oxycodone and pregabalin is effective for treating neuropathic cancer pain. We investigated the efficacy and tolerability of a dose-escalation combination therapy with prolonged-release oxycodone/naloxone (OXN-PR) and pregabalin in patients with non-small-cell lung cancer and severe neuropathic pain. METHODS: This was a 4-week, open-label, observational study. Patients were treated with OXN-PR and pregabalin. Average pain intensity ([API] measured on a 0-10 numerical rating scale) and neuropathic pain (Douleur Neuropathique 4) were assessed at study entry and at follow-up visits. The primary endpoint was response to treatment, defined as a reduction of API at T28 ≥30% from baseline. Secondary endpoints included other efficacy measures, as well as patient satisfaction and quality of life (Brief Pain Inventory Short Form), Hospital Anxiety and Depression Scale, and Symptom Distress Scale; bowel function was also assessed. RESULTS: A total of 56 patients were enrolled. API at baseline was 8.0±0.9, and decreased after 4 weeks by 48% (4.2±1.9; P<0.0001 vs baseline); 46 (82.1%) patients responded to treatment. Significant improvements were also reported in number/severity of breakthrough cancer pain episodes (P=0.001), Brief Pain Inventory Short Form (P=0.0002), Symptom Distress Scale (P<0.0001), Hospital Anxiety and Depression Scale depression (P=0.0006) and anxiety (P<0.0001) subscales, and bowel function (P=0.0003). At study end, 37 (66.0%) patients were satisfied/very satisfied with the new analgesic treatment. Combination therapy had a good safety profile. CONCLUSION: OXN-PR and pregabalin were safe and highly effective in a real-world setting of severe neuropathic cancer pain, with a high rate of satisfaction, without interference on bowel function

HP2IFS: Head Pose estimation exploiting Partitioned Iterated Function Systems

Estimating the actual head orientation from 2D images, with regard to its three degrees of freedom, is a well known problem that is highly significant for a large number of applications involving head pose knowledge. Consequently, this topic has been tackled by a plethora of methods and algorithms the most part of which exploits neural networks. Machine learning methods, indeed, achieve accurate head rotation values yet require an adequate training stage and, to that aim, a relevant number of positive and negative examples. In this paper we take a different approach to this topic by using fractal coding theory and particularly Partitioned Iterated Function Systems to extract the fractal code from the input head image and to compare this representation to the fractal code of a reference model through Hamming distance. According to experiments conducted on both the BIWI and the AFLW2000 databases, the proposed PIFS based head pose estimation method provides accurate yaw/pitch/roll angular values, with a performance approaching that of state of the art of machine-learning based algorithms and exceeding most of non-training based approaches

Speed and accuracy in wasp nestmate recognition: vision and olfaction

Dissertação de Mestrado em Ecologia, apresentada ao Departamento de Ciências da Vida da Faculdade de Ciências e Tecnologia da Universidade de Coimbra.A existência de condições desfavoráveis no solo (p.e. um agente químico) pode influenciar a presença de organismos de solo ou parâmetros do ciclo de vida tais como a reprodução da fauna do solo num local específico. Logo, a resposta de evitamento e o sucesso reprodutivo de organismos em locais contaminados pode ser utilizada como uma primeira ferramenta de avaliação de risco ecológico, já que respostas negativas de evitamento ou reprodução significam que deverá haver algum contaminante no solo testado. Neste trabalho abordou-se o problema da salinização dos solos, numa tentativa de avaliar o stress causado pela mesma nos invertebrados de solo, e o seu efeito conjunto com diferentes percentagens de matéria orgânica no solo, assim como com um pesticida frequentemente utilizado (lambda-cyalotrina). O objectivo final deste projecto era desenvolver modelos utilizando Modelação Linear Generalizada (GLM) que permitam prever valores de evitamento e reprodução quando um solo está contaminado com NaCl, e no caso específico de se encontrar também contaminado com o pesticida utilizado. Para alcançar o objectivo utilizaram-se três espécies de invertebrados de solo nos testes: Eisenia andrei, Folsomia candida e Enchytraeus crypticus. Folsomia candida e Eisenia andrei foram utilizados para os testes de evitamento, enquanto que para os testes de reprodução foram utilizados Folsomia candida e Enchytraeus crypticus. Os resultados obtidos pelos testes mostram uma efeito negativo claro da salinidade quer na resposta de evitamento quer na reprodução, e uma influência negatica do pesticida na reprodução de Folsomia candida. Os modelos obtidos explicam a maior parte da variável de resposta e podem vir a ser ferramentas robustas para prever valores de reprodução e evitamento em solos salinos.The existence of unfavorable conditions in soil (e.g. a chemical stressor) may influence the presence of soil organisms or life cycle parameters such as reproduction of soil fauna in a particular site. Therefore avoidance response and reproductive output of organisms to contaminated sites can be used as an early screening assessment of ecological risk, since a negative response on avoidance or reproduction means that there must be some contaminant in the tested soil. In this work the problem of soil salinization is addressed, in an attempt to evaluate the stress caused by soil salinization to soil invertebrates, and its combined effect with different organic matter percentages in the soil and also with a commonly used pesticide (lambda-cyalothrin). The final goal of this project was to develop predictive models using Generalized Linear Modeling (GLMs) that would allow to calculate a predicted value for avoidance response and reproductive output when a soil is contaminated with NaCl, and in the specific case of contamination by both NaCl and the pesticide. To achieve this, three species of soil invertebrates were used in the tests: Eisenia andrei, Folsomia candida and Enchytraeus crypticus. Folsomia candida and Eisenia andrei were used for the avoidance tests while for the reproduction tests Folsomia candida and Enchytraeus crypticus were selected. The results provided by the tests show a clear negative effect of salinity in both avoidance behavior and reproduction output, and a negative influence of the pesticide in the reproduction of Folsomia candida. The GLM models obtained explain most of the response variability and can become powerful tools for predicting avoidance and reproduction values in a saline soil

Percutaneous instrumentation with cement augmentation for traumatic hyperextension thoracic and lumbar fractures in ankylosing spondylitis: a single-institution experience

The typical traumatic thoracolumbar (TL) fracture in patients with ankylosing spondylitis (AS) is a hyperextension injury involving all three spinal columns, which is associated with unfavorable outcomes. Although a consensus on the management of these highly unstable injuries is missing, minimally invasive surgery (MIS) has been progressively accepted as a treatment option, since it is related to lower morbidity and mortality rates. This study aimed to evaluate clinical and radiological outcomes after percutaneous instrumentation with cement augmentation for hyperextension TL fractures in patients with AS at a single institution

Normal Maps vs. Visible Images: Comparing Classifiers and Combining Modalities

This work investigates face recognition based on normal maps, and the performance improvement that can be obtained when exploiting it within a multimodal system, where a further independent module processes visible images. We first propose a technique to align two 3D models of a face by means of normal maps, which is very fast while providing an accuracy comparable to well-known and more general techniques such as Iterative Closest Point (ICP). Moreover, we propose a matching criterion based on a technique which exploits difference maps. It does not reduce the dimension of the feature space, but performs a weighted matching between two normal maps. In the second place, we explore the range of performance soffered by different linear and non linear classifiers, when applied to the normal maps generated from the above aligned models. Such experiments highlight the added value of chromatic information contained in normal maps. We analyse a solid list of classifiers which we reselected due to their historical reference value (e.g. Principal Component Analysis) or to their good performances in the bidimensional setting (Linear Discriminant Analysis, Partitioned Iterated Function Systems). Last but not least, we perform experiments to measure how different ways of combining normal maps and visible images can enhance the results obtained by the single recognition systems, given that specific characteristics of the images are taken into account. For these last experiments we only consider the classifier giving the best average results in the preceding ones, namely the PIFS-based one

Synthetic cannabinoid use in a case series of patients with psychosis presenting to acute psychiatric settings : Clinical presentation and management issues

Background: Novel Psychoactive Substances (NPS) are a heterogeneous class of synthetic molecules including synthetic cannabinoid receptor agonists (SCRAs). Psychosis is associated with SCRAs use. There is limited knowledge regarding the structured assessment and psychometric evaluation of clinical presentations, analytical toxicology and clinical management plans of patients presenting with psychosis and SCRAs misuse. Methods: We gathered information regarding the clinical presentations, toxicology and care plans of patients with psychosis and SCRAs misuse admitted to inpatients services. Clinical presentations were assessed using the PANSS scale. Vital signs data were collected using the National Early Warning Signs tool. Analytic chemistry data were collected using urine drug screening tests for traditional psychoactive substances and NPS. Results: We described the clinical presentation and management plan of four patients with psychosis and misuse of SCRAs. Conclusion: The formulation of an informed clinical management plan requires a structured assessment, identification of the index NPS, pharmacological interventions, increases in nursing observations, changes to leave status and monitoring of the vital signs. The objective from using these interventions is to maintain stable physical health whilst rapidly improving the altered mental state.Peer reviewedFinal Published versio