Aberrant crypt Foci segmentation using computational vision

Colorectal cancer is a type of cancer that develops in the large intestine (colon) orthe rectum, one of the most common malignancies in the world. In this context, the aberrantcrypt foci may have a crucial and decisive role. The aberrant crypt foci are supposed to be theprecursors of colorectal cancer. This works aimed to develop computational methodologies forthe detection and segmentation of aberrant crypt foci in endoscopy images

Parameter estimation for a morphochemical reaction-diffusion model of electrochemical pattern formation

The process of electrodeposition can be described in terms of a reaction-diffusion PDE system that models the dynamics of the morphology profile and the chemical composition. Here we fit such a model to the different patterns present in a range of electrodeposited and electrochemically modified alloys using PDE constrained optimization. Experiments with simulated data show how the parameter space of the model can be divided into zones corresponding to the different physical patterns by examining the structure of an appropriate cost function. We then use real data to demonstrate how numerical optimization of the cost function can allow the model to fit the rich variety of patterns arising in experiments. The computational technique developed provides a potential tool for tuning experimental parameters to produce desired patterns

Análise computacional de imagens de focos de criptas aberrantes

Tese de mestrado. Engenharia Biomédica. Faculdade de Engenharia. Universidade do Porto. 201

Image-driven parameter estimation in absorption-diffusion models of chromoscopy

The administration of dyes and subsequent examination, with a colorimetry visual criterium, is a gastroenterology procedure for distinguishing, in endoscopic images, normal and aberrant colonic crypts. These are thought to be possible precursors of colon cancer. In this paper a combined image segmentation and parameter estimation model is proposed for in vivo colonic crypts’ images, obtained with chromoscopic colonoscopy. The parameter estimation is an inverse problem. It is formulated as a partial differential equation constrained optimization problem, and involves an absorption-diffusion equation. A Lagrange multiplier formulation is employed and analyzed for resolving this inverse problem. Using only the segmentation of the medical endoscopic image, which separates normal and aberrant crypts, the mathematical model, proposed in this paper, performs a non invasive mathematical, and dimensionless, quantification of the dye absorption and diffusion coefficients, as well as, the dye absorbed, in normal and aberrant colonic crypts. This mathematical quantification can be important for clinicians, if it is able to provide a distinction between individuals with and without cancer. Numerical simulations, on a test image and on some medical endoscopic images, are presented for the validation and evaluation of the proposed mathematical mode

Raman spectroscopy of biological tissue for application in optical diagnosis of malignancy

The use of Raman spectroscopy in the detection and classification of malignancy within the human larynx and lymph nodes of the head and neck has been evaluated. Currently histopathology is considered the diagnostic gold standard. The potential for Raman spectroscopy to be used as an in vivo diagnostic tool in the detection of dysplasia and malignancy has been demonstrated. A consensus opinion from three expert histopathologists has been obtained and spectral diagnostic models developed by correlation with these results. The ability of Raman spectroscopy to differentiate between disease entities and normal tissue within the larynx has been shown. Raman spectroscopy was able to identify non-neoplastic vocal cord mucosa (sensitivity 85 %, specificity 95%) from laryngeal mucosa showing neoplastic change (sensitivity 95 %, specificity 85%) with an increase in sensitivity to 89% for the non-neoplastic tissue and a reduction to73% in tissues showing neoplastic changes after cross-validation. For the first time benign changes in the structure of vocal cords such as those exhibiting hyperkeratosis and hyperplasia, where also identified with sensitivity of 97.9% for tissue exhibiting hyperplasia/hyperkeratosis and 100% for normal squamous cell epithelium. Research into the ability of Raman spectroscopy to interrogate lymphoid tissue in order to differentiate reactive nodes (sensitivity 90 %, specificity 88%) from those containing cancer (sensitivity 88 %, specificity 90%) was successful and fully independently validated. This work was further developed and the efficacy of Raman spectroscopy in differentiating between squamous cell carcinoma (sensitivity 76%, specificity 95%), adenocarcinoma (sensitivity 93 %, specificity 99%), Hodgkin‘s lymphoma (sensitivity 80%, specificity 90%) and reactive lymph nodes (sensitivity 81%, specificity 88%) was shown. This model was also independently cross-validated by node producing further improvements to give a spectral performance of sensitivity/specificity for SCC of 75/97%, adenocarcinoma 100/99%, Hodgkin‘s lymphoma 83/92% and reactive lymph nodes 85/86%.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

XXIV congreso anual de la sociedad española de ingeniería biomédica (CASEIB2016)

En la presente edición, más de 150 trabajos de alto nivel científico van a ser presentados en 18 sesiones paralelas y 3 sesiones de póster, que se centrarán en áreas relevantes de la Ingeniería Biomédica. Entre las sesiones paralelas se pueden destacar la sesión plenaria Premio José María Ferrero Corral y la sesión de Competición de alumnos de Grado en Ingeniería Biomédica, con la participación de 16 alumnos de los Grados en Ingeniería Biomédica a nivel nacional. El programa científico se complementa con dos ponencias invitadas de científicos reconocidos internacionalmente, dos mesas redondas con una importante participación de sociedades científicas médicas y de profesionales de la industria de tecnología médica, y dos actos sociales que permitirán a los participantes acercarse a la historia y cultura valenciana. Por primera vez, en colaboración con FENIN, seJane Campos, R. (2017). XXIV congreso anual de la sociedad española de ingeniería biomédica (CASEIB2016). Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/79277EDITORIA