Blind Source Separation in Persistent Atrial Fibrillation Electrocardiograms Using Block-Term Tensor Decomposition With Löwner Constraints.

The estimation of the atrial activity (AA) signal from electrocardiogram (ECG) recordings is an important step in the noninvasive analysis of atrial fibrillation (AF), the most common sustained arrhythmia encountered in clinical practice. This problem admits a blind source separation (BSS) formulation that has been recently posed as a tensor factorization, using the Hankel-based block term decomposition (BTD), which is particularly well-suited to the estimation of exponential models like AA during AF. However, persistent forms of AF are characterized by short R-R intervals and very disorganized (or weak) AA, making it difficult to model AA directly and perform its successful extraction through Hankel-BTD. To overcome this drawback, the present work proposes a tensor approach to estimate QRS complexes and subtract them from the ECG, resulting in a signal that, ideally, only contains the AA component. Such an approach tackles the problem of blind separation of rational functions, which models QRS complexes explicitly. The data tensor admitting a BTD is built from Löwner matrices generated from each lead of the observed ECG. To this end, this paper formulates a variant of the recently proposed constrained alternating group lasso (CAGL) algorithm that imposes Löwner structure on the decomposition blocks. This is done by performing an orthogonal projection, which we explicitly derive, at each iteration of CAGL. Results from experiments with synthetic data show the consistency of the proposed Löwner-constrained AGL (LCAGL) in extracting the desired sources. Experimental results obtained on a population of 20 patients suffering from persistent AF show that the proposed variant outperforms other tensor-based methods in terms of atrial signal estimation quality from ECG records as short as a single heartbeat.

Physical activity recommendations for cancer survivors living with bony metastases: views of oncologic healthcare providers.

PURPOSE: The potential of physical activity to improve function and quality of life of an individual with advanced cancer is now established. The purpose of this survey of oncologic healthcare providers (OHPs) is to understand their attitude towards physical activity for individuals living with bony metastases and to assess requirements to confidently provide physical activity recommendations. METHODS: A web-based survey administered through Qualtrics™ included questions on participant demographics and attitude questions ranked on a Likert scale. Eligibility was a physician or nurse practitioner currently providing care in the cancer care system of a public healthcare system in Canada. 338 participants were identified and invited to participate in this survey. RESULTS: The response rate was 34.6%. The majority of OHPs believed physical activity is important (89%) and safe (82%) in individuals living with bony metastases. OHPs agreed that these individuals looked to them for physical activity recommendations (74%) and that these recommendations would be followed (58%). Yet, 86% of OHPs felt they required more information before they could recommend physical activity to individuals living with bony metastases, and less than half (43%) of OHPs felt confident enough to prescribe physical activity. CONCLUSIONS: OHPs agree that physical activity for individuals living with bony metastatic cancer is beneficial and safe. However, OHPs are not confident in their ability to recommend physical activity to this population. IMPLICATIONS FOR CANCER SURVIVORS: There is a need to create physical activity guidelines for individuals living with bony metastases and improve access to rehabilitation services.

Ischemic stroke in an adult with glycogen storage disease type I.

Glycogen Storage Disease Type I (GSD-I) is a metabolic disorder characterized by deficiency of glucose-6-phosphatase resulting in ineffective glycogen metabolism to glucose. These patients frequently have hyperlipidemia, among many other metabolic derangements. There is no consensus regarding the risk of developing atherosclerosis. We report an adult male with GSD-I who presented with cerebral infarction and a history of prior ischemic stroke and multiple coronary stent placements. We suggest that patients with GSD-I do have an increased risk of atherosclerosis and its complications and predict that these complications will be seen more frequently since patients with GSD-I are living longer as a result of better treatment.

Fratura em eqüino: tratamento com fixador externo tipo Ilizarov / Horse fracture: treatment with Ilizarov type external fixatives

A idéia do uso de fixadores externos em fraturas é antiga, porém com resultados precários, devido à falta de noçöes precisas sobre a biofisiologia da formaçäo do calo ósseo. Ilizarov revolucionou os conceitos até entäo aceitos como verdadeiros pelas mais respeitadas escolas de ortopedia do mundo. O fixador Externo Circular tipo Ilizarov até o presente momento näo foi usado em grandes animais, pelo menos em pesquisas feitas na literatura a disposiçäo. Pelo resultado excepcional obtido, concluímos que qualquer tipo de fratura que permita a colocaçao do fixador circular poderá ser estabilizada e curada, evitando o sacrifício do animal

Crioevisceracao do globo ocular. / Eye crioevisceration

A crioevisceracao representa precesso cirurgico de facil execucao, cujo ato operatorio transcorre praticamente sem sangramentos e com um minimo de trauma, em menor espaco de tempo e cuja recuperacao tambem se faz mais rapida