Coding Prony's method in MATLAB and applying it to biomedical signal filtering

Background:The response of many biomedical systems can be modelled using a linear combination of damped exponential functions. The approximation parameters, based on equally spaced samples, can be obtained using Prony's method and its variants (e.g. the matrix pencil method). This paper provides a tutorial on the main polynomial Prony and matrix pencil methods and their implementation in MATLAB and analyses how they perform with synthetic and multifocal visual-evoked potential (mfVEP) signals. This paper briefly describes the theoretical basis of four polynomial Prony approximation methods: classic, least squares (LS), total least squares (TLS) and matrix pencil method (MPM). In each of these cases, implementation uses general MATLAB functions. The features of the various options are tested by approximating a set of synthetic mathematical functions and evaluating filtering performance in the Prony domain when applied to mfVEP signals to improve diagnosis of patients with multiple sclerosis (MS). Results:The code implemented does not achieve 100%-correct signal approximation and, of the methods tested, LS and MPM perform best. When filtering mfVEP records in the Prony domain, the value of the area under the receiver-operating-characteristic (ROC) curve is 0.7055 compared with 0.6538 obtained with the usual filtering method used for this type of signal (discrete Fourier transform low-pass filter with a cut-off frequency of 35 Hz). Conclusions:This paper reviews Prony's method in relation to signal filtering and approximation, provides the MATLAB code needed to implement the classic, LS, TLS and MPM methods, and tests their performance in biomedical signal filtering and function approximation. It emphasizes the importance of improving the computational methods used to implement the various methods described above.Universidad de AlcaláSecretaría de Estado de Investigación, Desarrollo e Innovació

Long-Term Anticoagulant Therapy of Patients with Venous Thromboembolism. What Are the Practices?

Current guidelines of antithrombotic therapy suggest early initiation of vitamin K antagonists (VKA) in non-cancer patients with venous thromboembolism (VTE), and long-term therapy with low-molecular weight heparin (LMWH) for those with cancer. We used data from RIETE (international registry of patients with VTE) to report the use of long-term anticoagulant therapy over time and to identify predictors of anticoagulant choice (regarding international guidelines) in patients with- and without cancer. Among 35,280 patients without cancer, 82% received long-term VKA (but 17% started after the first week). Among 4,378 patients with cancer, 66% received long term LMWH as monotherapy. In patients without cancer, recent bleeding (odds ratio [OR] 2.70, 95% CI 2.26-3.23), age >70 years (OR 1.15, 95% CI 1.06-1.24), immobility (OR 2.06, 95% CI 1.93-2.19), renal insufficiency (OR 2.42, 95% CI 2.15-2.71) and anemia (OR 1.75, 95% CI 1.65-1.87) predicted poor adherence to guidelines. In those with cancer, anemia (OR 1.83, 95% CI 1.64-2.06), immobility (OR 1.51, 95% CI 1.30-1.76) and metastases (OR 3.22, 95% CI 2.87-3.61) predicted long-term LMWH therapy. In conclusion, we report practices of VTE therapy in real life and found that a significant proportion of patients did not receive the recommended treatment. The perceived increased risk for bleeding has an impact on anticoagulant treatment decision

Diagnosis of multiple sclerosis using multifocal ERG data feature fusion

The purpose of this paper is to implement a computer-aided diagnosis (CAD) system for multiple sclerosis (MS) based on analysing the outer retina as assessed by multifocal electroretinograms (mfERGs). MfERG recordings taken with the RETI?port/scan 21 (Roland Consult) device from 15 eyes of patients diagnosed with incipient relapsing-remitting MS and without prior optic neuritis, and from 6 eyes of control subjects, are selected. The mfERG recordings are grouped (whole macular visual field, five rings, and four quadrants). For each group, the correlation with a normative database of adaptively filtered signals, based on empirical model decomposition (EMD) and three features from the continuous wavelet transform (CWT) domain, are obtained. Of the initial 40 features, the 4 most relevant are selected in two stages: a) using a filter method and b) using a wrapper-feature selection method. The Support Vector Machine (SVM) is used as a classifier. With the optimal CAD configuration, a Matthews correlation coefficient value of 0.89 (accuracy = 0.95, specificity = 1.0 and sensitivity = 0.93) is obtained. This study identified an outer retina dysfunction in patients with recent MS by analysing the outer retina responses in the mfERG and employing an SVM as a classifier. In conclusion, a promising new electrophysiological-biomarker method based on feature fusion for MS diagnosis was identified.Agencia Estatal de InvestigaciónInstituto de Salud Carlos II

Clinical Characteristics and Outcomes of Patients with Lung Cancer and Venous Thromboembolism

Background. The natural history of patients with lung cancer and venous thromboembolism (VTE) has not been consistently evaluated. Methods  We used the RIETE (Registro Informatizado Enfermedad TromboEmbólica) database to assess the clinical characteristics, time course, and outcomes during anticoagulation of lung cancer patients with acute, symptomatic VTE. Results  As of May 2017, a total of 1,725 patients were recruited: 1,208 (70%) presented with pulmonary embolism (PE) and 517 with deep vein thrombosis (DVT). Overall, 865 patients (50%) were diagnosed with cancer <3 months before, 1,270 (74%) had metastases, and 1,250 (72%) had no additional risk factors for VTE. During anticoagulation (median, 93 days), 166 patients had symptomatic VTE recurrences (recurrent DVT: 86, PE: 80), 63 had major bleeding (intracranial 11), and 870 died. The recurrence rate was twofold higher than the major bleeding rate during the first month, and over threefold higher beyond the first month. Fifty-seven patients died of PE and 15 died of bleeding. Most fatal PEs (84%) and most fatal bleeds (67%) occurred within the first month of therapy. Nine patients with fatal PE (16%) died within the first 24 hours. Of 72 patients dying of PE or bleeding, 15 (21%) had no metastases and 29 (40%) had the VTE shortly after surgery or immobility. Conclusion  Active surveillance on early signs and/or symptoms of VTE in patients with recently diagnosed lung cancer and prescription of prophylaxis in those undergoing surgery or during periods of immobilization might likely help prevent VTE better, detect it earlier, and treat it more efficiently.publishersversionPeer reviewe

Differential Study of Retinal Thicknesses in the Eyes of Alzheimer"s Patients, Multiple Sclerosis Patients and Healthy Subjects

Multiple sclerosis (MS) and Alzheimer"s disease (AD) cause retinal thinning that is detectable in vivo using optical coherence tomography (OCT). To date, no papers have compared the two diseases in terms of the structural differences they produce in the retina. The purpose of this study is to analyse and compare the neuroretinal structure in MS patients, AD patients and healthy subjects using OCT. Spectral domain OCT was performed on 21 AD patients, 33MS patients and 19 control subjects using the Posterior Pole protocol. The area under the receiver operating characteristic (AUROC) curve was used to analyse the differences between the cohorts in nine regions of the retinal nerve fibre layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL) and outer nuclear layer (ONL). The main differences between MS and AD are found in the ONL, in practically all the regions analysed (AUROCFOVEAL = 0.80, AUROCPARAFOVEAL = 0.85, AUROCPERIFOVEAL = 0.80, AUROC_PMB = 0.77, AUROCPARAMACULAR = 0.85, AUROCINFERO_NASAL = 0.75, AUROCINFERO_TEMPORAL = 0.83), and in the paramacular zone (AUROCPARAMACULAR = 0.75) and infero-temporal quadrant (AUROCINFERO_TEMPORAL = 0.80) of the GCL. In conclusion, our findings suggest that OCT data analysis could facilitate the differential diagnosis of MS and AD

Flexibilidad psicológica y autoabandono del tabaco

The prevalence of smoking in the general population remains high in spite of the extended acknowledgement of the well-documented health consequences of smoking and potential benefits of quitting. Only a minority of smokers who attempt to quit seeks professional treatment, yet most of the research on smoking cessation focuses on such form of quitting. Research on self-quitting is scarce, although most smokers who successfully quit, do so on their own. Recently, research has evidenced that psychological flexibility, a core concept in Acceptance and Commitment Therapy, is an important variable in predicting successful behavioral change in many clinically relevant areas. The goal of this study was to analyze the relationship between psychological flexibility and successful self-quitting from smoking. 277 participants who had attempted to quit on their own (217 successfully abstinent and 60 still smoking) provided information on their smoking history, quit attempts, nicotine dependence, and demographics, and were assessed with the Acceptance and Action Questionnaire-II. Abstinence status was measured through self-reports of continuous abstinence and confirmed by concentrations of expired carbon monoxide below 8 ppm. Results show a statistically significant difference (t= -8, 775; p <.01) for the AAQ-II scores of successful (M= 18.39, SD= 7.76) and unsuccessful self-quitters (M= 27.17; SD= 6.88). Only 26% participants with high level of psychological inflexibility quitted successfully, compared to 94% participants with low levels of psychological inflexibility. These results show clear evidence that psychological flexibility is associated to successful self-quitting, and suggest that this variable could facilitate success in attempts to stop smoking without professional help. Implications and limitations of this study are discussed

Analytical tools for the multiplex rapid detection of SARS-CoV-2

There is a high demand for analytical tools that can readily be applied to effectively diagnose the Covid-19 but also to carry out screening and surveillance detection with enough frequency to get the transmission rates under control and thus help to timely tackling the disease. On the one hand, high throughput analytical benchtop approaches are still highly demanding for accelerating diagnostics. Such platforms are required to show multiplexed capabilities while in turn reducing the turnaround times of currently applied techniques such as the RT-PCR gold standard. On the other hand, massive screening and surveillance protocols still require for effective tools at the point of need that could reliably detect the virus in individuals after being exposed or the likelihood of being immunized after suffering from the disease. The rapid detection of coronavirus biomarkers, including RNA as well as spike and nucleocapsid proteins in nasopharyngeal and oropharyngeal samples, together with host biomarkers such as immunoglobulins and cytokines in serum has been addressed in this work. We aim to produce tools that provided with a global response to the diagnosis, prognosis and follow-up of the disease (Figure 1). All the biocomponents and corresponding bioassay protocols required for measuring these biomarkers have been tailored made and implemented in three different platforms. A calorimetric device based on a lateral flow assay format [1, 2] and a multiplex electrochemical platform comprising an electrochemical transducer array and a paper microfluidic component [3] have been adapted to produce tools to be used at the point of care. Likewise, a fluorescence microarray platform has been set up with the potential for high-throughput screening by recording molecular signatures thanks to the its multiplexing and miniaturization capabilities. REFERENCES [1] E. Polo et al. PCT, ES2013/070549 [2] E. Polo et al. Chem. Commun., 49 (2013) 3676 [3] C. Fernández-Sánchez et al. Application no. EP20382721.

Un siglo de luz : Historia empresarial de Iberdrola

El libro se divide en épocas y, dentro de cada una de ellas, se analizan los avatares de las tres empresas fundadoras de Iberdrola. La parte I tiene carácter de introducción y sus dos capítulos responden al deseo de integrar la historia de Iberdrola, tanto en el sector eléctrico espafíol como en el de otros países de Europa. La parte II abarca hasta el afío 1944, fecha de la fusión entre Saltos del Duero e Hidroeléctrica Ibérica. La parte III comprende los afíos 1944-1973, con la crisis energética como límite diferenciador. La parte IV comprende desde el comienzo de la crisis hasta la fusión de Iberduero e Hidrola, en 1991. La última parte del libro, en la que se hace la historia reciente de la empresa, ha sido escrita por sus principales protagonistas, lo cual afíade un interés muy especial a los capítulos catorce, quince y dieciséis, con los que termina la obra

Programa de captación de estudiantes de Bachillerato del distrito universitario de Salamanca (3ª Edición). Facultad de Filosofía – Universidad de Salamanca

Memoria ID-0267. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2014-2015