Motion Artifact Reduction in Breast Dynamic Infrared Imaging

Dynamic infrared imaging is a promising technique in breast oncology. In this study a QWIP infrared camera is used to acquire a sequence of consecutive thermal images of the patient's breast for 10 s. Information on the local blood perfusion is obtained from the spectral analysis of the time series at each image pixel. Due to respiratory and motion artifacts, the direct comparison of the temperature values that a pixel assumes along the sequence becomes difficult. In fact, the small temperature changes due to blood perfusion, of the order of 10-50 mK, which constitute the signal of interest in the time domain, are superimposed onto large temperature fluctuations due to the subject's motion, which represent noise. To improve the time series signal-to-noise ratio, and, as a consequence, enhance the specificity and sensitivity of the dynamic infrared examination, it is important to realign the thermal images of the acquisition sequence thus reducing motion artifacts. In a previous study we demonstrated that a registration algorithm based on fiducial points is suitable to both clinical applications and research, when associated with a proper set of skin markers. In this paper, we quantitatively evaluate the performance of different marker sets by means of a model that allows for estimating the signal-to-noise ratio increment due to registration, and we conclude that a 12-marker set is a good compromise between motion artifact reduction and the time required to prepare the patien

Documento preliminare all'avvio della progettazione (Dpp) e progetto di un nido d'infanzia e ludoteca aziendali per l'Universita di Pisa a Cisanello

L’oggetto della Tesi di Laurea risponde all’esigenza manifestata dall’Università di Pisa di realizzare un nido d’infanzia e ludoteca aziendali per allargare la tipologia dei servizi offerti per la prima infanzia al proprio personale docente, tecnico amministrativo e studentesco. Lo studio è partito con la Fase Informativa nella quale è stata analizzata l’evoluzione sia del tipo edilizio dalle origini agli esempi contemporanei nazionali e internazionali, sia della normativa dalla Legge 2277 del 1925 al Regolamento Regionale 433 del 2013. La redazione del DPP è servita per definire le esigenze, i requisiti e le prestazioni attese richiesti dalla committenza in modo da costituire lo strumento di lavoro di partenza per i progettisti e una base di verifica degli elaborati in modo da rendere più efficace il cammino durante tutto il processo edilizio. La proposta progettuale, partendo dallo studio del contesto urbano e del tipo edilizio, è stata elaborata in stretta integrazione e come risposta alle due precedenti fasi. Particolare attenzione è stata dedicata all’obiettivo di minimizzare l’impiego di risorse non rinnovabili e nel massimo utilizzo di quelle rinnovabili proponendo l’impiego di sistemi per la sostenibilità e il risparmio energetico arrivando a suggerire l’impiego di materiali ben specifici. Tutto lo studio è stato realizzato secondo il principio che un edificio scolastico ben progettato e ben costruito costituisce una opportunità unica di educazione: quando una tecnologia è efficiente e un progetto efficace l’edificio stesso può insegnare

Evaluation of time-series registration methods in dynamic area telethermometry for breast cancer detection

Automated motion reduction in 3D dynamic infrared imaging is on demand in many applications. Few methods for registering time-series dynamic infrared frames have been proposed. Almost all such methods are feature based algorithms requiring manual intervention. We apply different automated registration methods based on spatial displacement to 11 datasets of Breast Dynamic Infrared Imaging (DIRI) and evaluate the results in terms of both the image similarity and anatomical consistency of the transformation. The aim is to optimize the registration strategy for breast DIRI in order to improve the spectral analysis of temperature modulation; thus facilitating the acquisition procedure in a Dynamic Area Telethermometry framework. The results show that symmetric diffeomorphic demons registration outperforms both warped frames similarity and smoothness of deformation fields; hence proving effective for time-series dynamic infrared registratio

Reduction of gait abnormalities in type 2 diabetic patients due to physical activity: a quantitative evaluation based on statistical gait analysis

The aim of this study is the objective assessment of gait abnormalities in diabetic patients and the quantification of the benefits of physical activity in improving the gait quality. Patients were equipped with foot-switches and knee goniometers and were asked to walk at their natural pace for 2.5 minutes. A statistical gait analysis was performed extracting from hundreds of strides the ‘atypical' cycles, i.e. the cycles which do not show the usual sequence of gait phases (heel contact, flat foot contact, push off, swing), the duration of the heel contact phase and the knee kinematics in the sagittal plane. A sample population of 27 non-neuropathic type 2 diabetic patients was examined before and after attending a light-intensity physical activity program that lasted four months. A fuzzy classifier was used to assign a score to the gait abnormalities of each patient in baseline conditions and after the program completion. More than 50% of the subjects reduced significantly their gait abnormalities and, on the average, the most frequent improvements were the reduction of atypical cycles and heel contact duration. Furthermore we found that, in basal conditions, the left side is more affected by gait abnormalities than the right one (P < 0.003