On the determination of the interface density of states in a-Si:H/a-SiC:H multilayers

This paper deals with the determination of the interface density of states in amorphous silicon-based multilayers. Photothermal deflection spectroscopy is used to characterize two series of aSi:H/aSi1-xCx:H multilayers, and a new approach in the treatment of experimental dada is used in order to obtain accurate results. From this approach, an upper limit of 10^10 cm-2 is determined for the interface density of states

Relaxation and derelaxation of pure and hydrogenated amorphous silicon during thermal annealing experiments

The structural relaxation of pure amorphous silicon (a-Si) and hydrogenated amorphous silicon (a-Si:H) materials, that occurs during thermal annealing experiments, has been analysed by Raman spectroscopy and differential scanning calorimetry. Unlike a-Si, the heat evolved from a-Si:H cannot be explained by relaxation of the Si-Si network strain, but it reveals a derelaxation of the bond angle strain. Since the state of relaxation after annealing is very similar for pure and hydrogenated materials, our results give strong experimental support to the predicted configurational gap between a-Si and crystalline silicon.Comment: 15 pages, 3 figures, 1 table to be published in Applied Physics Letter

La praxis de la Congregación para la Doctrina de la Fe, expresión de un “cambio de mentalidad”

The study of some aspects of the modus operandi at the CDF, faithful interpreter of disciplinary jurisprudence in canon law, confirms what Pope Francis has referred to as a “change of mentality”, which has come about over the last twenty years. This shift in thinking has occurred not only in the CDF, but across all ecclesial dimensions of hierarchical communion, and aims to act decisively and effectively to prevent child abuse, the main “ecclesial scourge” of our time. Although, for a variety reasons, a certain indecisiveness may have prevailed among pastors during the latter half of the twentieth century with regard to the application of canonical penalties, despite their status as ultima ratio, the scandal caused by cases of delicta graviora and their impact have prompted the rediscovery, reassessment and renewed appreciation for canonical penal law.El estudio de algunos aspectos de la praxis de la CDF, fiel intérprete jurisprudencial de la disciplina penal canónica, permite confirmar sin género de dudas, con las mismas palabras de Francisco, el “cambio de mentalidad” operado a lo largo de los últimos dos decenios no solo en el Supremo Legislador, sino en todas las instancias eclesiales de la comunión jerárquica, siempre con el objetivo de atajar con decisión y con la máxima eficacia los abusos a menores, que han sido calificados como la principal “lacra eclesial” del momento presente. Si en las últimas décadas del s. XX, por diversos motivos, era común la indecisión entre los Pastores al tener que aplicar la potestad punitiva en la Iglesia, no obstante su condición de ultima ratio, el escándalo provocado por los casos de delicta graviora y sus repercusiones, han sido un acicate para el redescubrimiento, valoración y estima del derecho penal canónico

Discrimination Between CFAEs of Paroxysmal and Persistent Atrial Fibrillation With Simple Classification Models of Reduced Features

[EN] A significant number of variables to discriminate between paroxysmal and persistent atrial fibrillation (ParAF vs. PerAF) has been widely exploited, mostly assessed with statistical tests aimed to suggest adequate approaches for catheter ablation (CA) of AF. However, in practice, it would be desirable to utilize simple classification models readily understandable. In this work dominant frequency (DF), AF cycle length (AFCL), sample entropy (SE) and determinism (DET) of recurrent quantification analysis were applied to recordings of complex fractionated atrial electrograms (CFAEs) of AF patients, aimed to create simple models to discriminate between ParAF and PerAF. Correlation matrix filters removed redundant information and Random Forests ranked the variables by relevance. Next, coarse tree models were built, optimally combining high-ranking indexes, and tested with leave-one-out cross-validation. The best classification performance combined SE and DF with an Accuracy (Acc) of 88.2% to discriminate ParAF from PerAF, while the highest single Acc was provided by DET reaching 82.4%. Hence, careful selection of reduced sets of features feeding simple classification models is able to discriminate accurately between CFAEs of ParAF and PerAFFinotti, E.; Ciaccio, EJ.; Garan, H.; Bertomeu-Gonzalez, V.; Alcaraz, R.; Rieta, JJ. (2020). Discrimination Between CFAEs of Paroxysmal and Persistent Atrial Fibrillation With Simple Classification Models of Reduced Features. IEEE. 1-4. https://doi.org/10.22489/CinC.2020.360S1

Short-Time Estimation of Fractionation in Atrial Fibrillation with Coarse-Grained Correlation Dimension for Mapping the Atrial Substrate

[EN] Atrial ¿brillation (AF) is currently the most common cardiac arrhythmia, with catheter ablation (CA) of the pulmonary veins (PV) being its ¿rst line therapy. Ablation of complex fractionated atrial electrograms (CFAEs) outside the PVs has demonstrated improved long-term results, but their identi¿cation requires a reliable electrogram (EGM) fractionation estimator. This study proposes a technique aimed to assist CA procedures under real-time settings. The method has been tested on three groups of recordings: Group 1 consisted of 24 highly representative EGMs, eight of each belonging to a different AF Type. Group 2 contained the entire dataset of 119 EGMs, whereas Group 3 contained 20 pseudo-real EGMs of the special Type IV AF. Coarse-grained correlation dimension (CGCD) was computed at epochs of 1 s duration, obtaining a classi¿cation accuracy of 100% in Group 1 and 84.0¿85.7% in Group 2, using 10-fold cross-validation. The receiver operating characteristics (ROC) analysis for highly fractionated EGMs, showed 100% speci¿city and sensitivity in Group 1 and 87.5% speci¿city and 93.6% sensitivity in Group 2. In addition, 100% of the pseudo-real EGMs were correctly identi¿ed as Type IV AF. This method can consistently express the fractionation level of AF EGMs and provides better performance than previous works. Its ability to compute fractionation in short-time can agilely detect sudden changes of AF Types and could be used for mapping the atrial substrate, thus assisting CA procedures under real-time settings for atrial substrate modi¿cation.This research has been supported by grants DPI2017-83952-C3 from MINECO/AEI/FEDER EU, SBPLY/17/180501/000411 from JCCM and AICO/2019/036 from GVA.Vraka, A.; Hornero, F.; Bertomeu-Gonzalez, V.; Osca, J.; Alcaraz, R.; Rieta, JJ. (2020). Short-Time Estimation of Fractionation in Atrial Fibrillation with Coarse-Grained Correlation Dimension for Mapping the Atrial Substrate. Entropy. 22(2):1-20. https://doi.org/10.3390/e22020232S120222Go, A. S., Hylek, E. M., Phillips, K. A., Chang, Y., Henault, L. E., Selby, J. V., & Singer, D. E. (2001). Prevalence of Diagnosed Atrial Fibrillation in Adults. JAMA, 285(18), 2370. doi:10.1001/jama.285.18.2370Goette, A., Honeycutt, C., & Langberg, J. J. (1996). Electrical Remodeling in Atrial Fibrillation. Circulation, 94(11), 2968-2974. doi:10.1161/01.cir.94.11.2968Chugh, S. S., Roth, G. A., Gillum, R. F., & Mensah, G. A. (2014). Global Burden of Atrial Fibrillation in Developed and Developing Nations. Global Heart, 9(1), 113. doi:10.1016/j.gheart.2014.01.004Cappato, R., Calkins, H., Chen, S.-A., Davies, W., Iesaka, Y., Kalman, J., … Biganzoli, E. (2010). Updated Worldwide Survey on the Methods, Efficacy, and Safety of Catheter Ablation for Human Atrial Fibrillation. Circulation: Arrhythmia and Electrophysiology, 3(1), 32-38. doi:10.1161/circep.109.859116Cox, J. L., Canavan, T. E., Schuessler, R. B., Cain, M. E., Lindsay, B. D., Stone, C., … Boineau, J. P. (1991). The surgical treatment of atrial fibrillation. The Journal of Thoracic and Cardiovascular Surgery, 101(3), 406-426. doi:10.1016/s0022-5223(19)36723-6Haïssaguerre, M., Jaïs, P., Shah, D. C., Takahashi, A., Hocini, M., Quiniou, G., … Clémenty, J. (1998). Spontaneous Initiation of Atrial Fibrillation by Ectopic Beats Originating in the Pulmonary Veins. New England Journal of Medicine, 339(10), 659-666. doi:10.1056/nejm199809033391003Kornej, J., Schumacher, K., Zeynalova, S., Sommer, P., Arya, A., Weiß, M., … Hindricks, G. (2019). Time-dependent prediction of arrhythmia recurrences during long-term follow-up in patients undergoing catheter ablation of atrial fibrillation: The Leipzig Heart Center AF Ablation Registry. 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Circulation: Arrhythmia and Electrophysiology, 7(5), 825-833. doi:10.1161/circep.113.001251Takahashi, Y., O’Neill, M. D., Hocini, M., Dubois, R., Matsuo, S., Knecht, S., … Haïssaguerre, M. (2008). Characterization of Electrograms Associated With Termination of Chronic Atrial Fibrillation by Catheter Ablation. Journal of the American College of Cardiology, 51(10), 1003-1010. doi:10.1016/j.jacc.2007.10.056Atienza, F., Almendral, J., Jalife, J., Zlochiver, S., Ploutz-Snyder, R., Torrecilla, E. G., … Berenfeld, O. (2009). Real-time dominant frequency mapping and ablation of dominant frequency sites in atrial fibrillation with left-to-right frequency gradients predicts long-term maintenance of sinus rhythm. Heart Rhythm, 6(1), 33-40. doi:10.1016/j.hrthm.2008.10.024Nademanee, K., McKenzie, J., Kosar, E., Schwab, M., Sunsaneewitayakul, B., Vasavakul, T., … Ngarmukos, T. (2004). A new approach for catheter ablation of atrial fibrillation: mapping of the electrophysiologic substrate. Journal of the American College of Cardiology, 43(11), 2044-2053. doi:10.1016/j.jacc.2003.12.054Ciaccio, E. J., Biviano, A. B., Whang, W., Coromilas, J., & Garan, H. (2011). A new transform for the analysis of complex fractionated atrial electrograms. BioMedical Engineering OnLine, 10(1), 35. doi:10.1186/1475-925x-10-35Ciaccio, E. J., Biviano, A. B., & Garan, H. (2013). Computational method for high resolution spectral analysis of fractionated atrial electrograms. Computers in Biology and Medicine, 43(10), 1573-1582. doi:10.1016/j.compbiomed.2013.07.033TSAI, W.-C., LIN, Y.-J., TSAO, H.-M., CHANG, S.-L., LO, L.-W., HU, Y.-F., … CHEN, S.-A. (2010). The Optimal Automatic Algorithm for the Mapping of Complex Fractionated Atrial Electrograms in Patients With Atrial Fibrillation. Journal of Cardiovascular Electrophysiology, 21(1), 21-26. doi:10.1111/j.1540-8167.2009.01567.xTeh, A. W., Kistler, P. M., Lee, G., Medi, C., Heck, P. M., Spence, S. J., … Kalman, J. M. (2011). The relationship between complex fractionated electrograms and atrial low-voltage zones during atrial fibrillation and paced rhythm. Europace, 13(12), 1709-1716. doi:10.1093/europace/eur197Lin, Y.-J., Lo, M.-T., Chang, S.-L., Lo, L.-W., Hu, Y.-F., Chao, T.-F., … Chen, S.-A. (2016). Benefits of Atrial Substrate Modification Guided by Electrogram Similarity and Phase Mapping Techniques to Eliminate Rotors and Focal Sources Versus Conventional Defragmentation in Persistent Atrial Fibrillation. JACC: Clinical Electrophysiology, 2(6), 667-678. doi:10.1016/j.jacep.2016.08.005Verma, A., Jiang, C., Betts, T. R., Chen, J., Deisenhofer, I., Mantovan, R., … Sanders, P. (2015). Approaches to Catheter Ablation for Persistent Atrial Fibrillation. New England Journal of Medicine, 372(19), 1812-1822. doi:10.1056/nejmoa1408288Ammar-Busch, S., Reents, T., Knecht, S., Rostock, T., Arentz, T., Duytschaever, M., … Deisenhofer, I. (2018). Correlation between atrial fibrillation driver locations and complex fractionated atrial electrograms in patients with persistent atrial fibrillation. Pacing and Clinical Electrophysiology, 41(10), 1279-1285. doi:10.1111/pace.13483Almeida, T. P., Chu, G. S., Salinet, J. L., Vanheusden, F. J., Li, X., Tuan, J. H., … Schlindwein, F. S. (2016). Minimizing discordances in automated classification of fractionated electrograms in human persistent atrial fibrillation. Medical & Biological Engineering & Computing, 54(11), 1695-1706. doi:10.1007/s11517-016-1456-2De Bakker, J. M. T., & Wittkampf, F. H. M. (2010). The Pathophysiologic Basis of Fractionated and Complex Electrograms and the Impact of Recording Techniques on Their Detection and Interpretation. Circulation: Arrhythmia and Electrophysiology, 3(2), 204-213. doi:10.1161/circep.109.904763Luca, A., Buttu, A., Pruvot, E., Pascale, P., Bisch, L., & Vesin, J.-M. (2016). Nonlinear analysis of right atrial electrograms predicts termination of persistent atrial fibrillation within the left atrium by catheter ablation. Physiological Measurement, 37(3), 347-359. doi:10.1088/0967-3334/37/3/347Corana, A., Casaleggio, A., Rolando, C., & Ridella, S. (1991). Efficient computation of the correlation dimension from a time series on a LIW computer. Parallel Computing, 17(6-7), 809-820. doi:10.1016/s0167-8191(05)80068-7Fraser, A. M., & Swinney, H. L. (1986). Independent coordinates for strange attractors from mutual information. Physical Review A, 33(2), 1134-1140. doi:10.1103/physreva.33.1134Martínez-Iniesta, M., Ródenas, J., Alcaraz, R., & Rieta, J. J. (2017). Waveform Integrity in Atrial Fibrillation: The Forgotten Issue of Cardiac Electrophysiology. Annals of Biomedical Engineering, 45(8), 1890-1907. doi:10.1007/s10439-017-1832-6Theiler, J., Eubank, S., Longtin, A., Galdrikian, B., & Doyne Farmer, J. (1992). Testing for nonlinearity in time series: the method of surrogate data. Physica D: Nonlinear Phenomena, 58(1-4), 77-94. doi:10.1016/0167-2789(92)90102-sNakamura, T., Small, M., & Hirata, Y. (2006). Testing for nonlinearity in irregular fluctuations with long-term trends. Physical Review E, 74(2). doi:10.1103/physreve.74.026205SHAPIRO, S. S., & WILK, M. B. (1965). An analysis of variance test for normality (complete samples). Biometrika, 52(3-4), 591-611. doi:10.1093/biomet/52.3-4.591Mandelbrot, B. (1961). Contributions to Probability and Statistics: Essays in Honor of Harold Hotelling (Ingram Olkin, Sudhist G. Ghurye, Wassily Hoeffding, William G. Madow, and Henry B. Mann, eds.). SIAM Review, 3(1), 80-80. doi:10.1137/1003016Mann, H. B., & Whitney, D. R. (1947). On a Test of Whether one of Two Random Variables is Stochastically Larger than the Other. 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Splitting the P-Wave: Improved Evaluation of Left Atrial Substrate Modification after Pulmonary Vein Isolation of Paroxysmal Atrial Fibrillation

[EN] Atrial substrate modification after pulmonary vein isolation (PVI) of paroxysmal atrial fibrillation (pAF) can be assessed non-invasively by analyzing P-wave duration in the electrocardiogram (ECG). However, whether right (RA) and left atrium (LA) contribute equally to this phenomenon remains unknown. The present study splits fundamental P-wave features to investigate the different RA and LA contributions to P-wave duration. Recordings of 29 pAF patients undergoing first-ever PVI were acquired before and after PVI. P-wave features were calculated: P-wave duration (PWD), duration of the first (PWDon-peak) and second (PWDpeak-off) P-wave halves, estimating RA and LA conduction, respectively. P-wave onset (PWon-R) or offset (PWoff-R) to R-peak interval, measuring combined atrial/atrioventricular and single atrioventricular conduction, respectively. Heart-rate fluctuation was corrected by scaling. Pre- and post-PVI results were compared with Mann-Whitney U-test. PWD was correlated with the remaining features. Only PWD (non-scaling: & UDelta;=-9.84%, p=0.0085, scaling: & UDelta;=-17.96%, p=0.0442) and PWDpeak-off (non-scaling: & UDelta;=-22.03%, p=0.0250, scaling: & UDelta;=-27.77%, p=0.0268) were decreased. Correlation of all features with PWD was significant before/after PVI (p < 0.0001), showing the highest value between PWD and PWon-R (rho max=0.855). PWD correlated more with PWDon-peak (rho= 0.540-0.805) than PWDpeak-off (rho= 0.419-0.710). PWD shortening after PVI of pAF stems mainly from the second half of the P-wave. Therefore, noninvasive estimation of LA conduction time is critical for the study of atrial substrate modification after PVI and should be addressed by splitting the P-wave in order to achieve improved estimations.This research received financial support from public grants DPI2017-83952-C3, PID2021-00X128525-IV0 and PID2021-123804OB-I00 of the Spanish Government 10.13039/501100011033 jointly with the European Regional Development Fund (EU), SBPLY/17/180501/000411 from Junta de Comunidades de Castilla-La Mancha and AICO/2021/286 from Generalitat Valenciana.Vraka, A.; Bertomeu-González, V.; Hornero, F.; Quesada, A.; Alcaraz, R.; Rieta, JJ. (2022). Splitting the P-Wave: Improved Evaluation of Left Atrial Substrate Modification after Pulmonary Vein Isolation of Paroxysmal Atrial Fibrillation. Sensors. 22(1):1-13. https://doi.org/10.3390/s2201029011322

Linear and Nonlinear Correlations Between Surface and Invasive Atrial Activation Features in Catheter Ablation of Paroxysmal Atrial Fibrillation

[EN] P-waves are vastly used to assess the outcome of catheter ablation (CA) of atrial fibrillation (AF). It remains unknown, however, if coronary sinus (CS), the key reference structure in CA procedures, follows similar patterns. This study¿s objective is to detect any correlations between the behavior of P-waves and CS local activation waves (LAWs) with regard to CA procedure. Duration, amplitude, area and slope rate were studied in P-waves and LAWs of five-minute recordings from 29 patients undergoing paroxysmal AF CA. Normalization (N) due to heart rate (HR) fluctuations was performed. Pearson¿s correlation (PC) between CA-induced variations (¿) of P-waves and LAWs was calculated. Linear correlations between each P-wave/LAW were studied with PC and linear regression with 10¿fold cross-validation. Cross-quadratic sample entropy (CQSE) assessed nonlinear correlations. PC (¿ : ¿ < 52.27%, p = 0.015, P-wave/LAW: ¿ < 40.37%, p = 0.001) and linear regression analysis (R2 ¿ adj < 16.02%, p = 0.015 ) showed low/mediocre linear correlations. CQSE ( 0.8 ¿ 1.3) also suggested weak nonlinear relationships. P-waves and LAWs are poorly correlated and do not describe to the same degree the substrate modification after CA. It is possible that P-waves reflect the cumulative CA-induced modifications of various atrial sites, with CS being one of them but not the dominant.Research supported by grants DPI2017-83952-C3 from MINECO/AEI/FEDER UE, SBPLY/17/180501/000411 from JCCLM and AICO/2021/286 from GVA.Vraka, A.; Bertomeu-González, V.; Hornero, F.; Ravelli, F.; Alcaraz, R.; Rieta, JJ. (2021). Linear and Nonlinear Correlations Between Surface and Invasive Atrial Activation Features in Catheter Ablation of Paroxysmal Atrial Fibrillation. 1-4. https://doi.org/10.22489/CinC.2021.0291

Are Coronary Sinus Features Reflecting the Effect of Catheter Ablation of Atrial Fibrillation as P-waves Do?

[EN] Atrial substrate alteration due to catheter ablation (CA) of atrial fibrillation (AF) is primarily assessed from P-waves. Nonetheless, how CA affects critical structures is ignored. The aim of the current study is to investigate if CA effect on CS, the principal CA reference, is related to that observed from P-waves analysis. Five-minute lead II and bipolar CS recordings of 29 paroxysmal AF patients were obtained before, during and after CA. Duration, amplitude, area and heart-rate (HR) variability (HRV) features were calculated for P-waves and local activation waves (LAWs). Normalization mitigated the effect of HR fluctuations. Linear correlations between each P-wave and LAW were tested with linear regression (LR) and Pearson correlation (PC) and nonlinear correlations with cross-quadratic sample entropy (CQSE). Correlation between the CA effect on P-waves and LAWs was investigated with PC. Negligent statistical correlations were found by PC and LR for amplitude and area (¿3.30% 90%, p < 0.0297). Apart from HRV, no significant correlations between CS LAWs and P-waves have been found. HR fluctuations mask any possible tuning and normalization should be applied prior to the analysis.Research supported by grants DPI2017¿83952¿C3 from MINECO/AEI/FEDER UE, SBPLY/17/180501/000411 from JCCLM and AICO/2021/286 from GVA.Vraka, A.; Bertomeu-González, V.; Hornenro, F.; Langley, P.; Alcaraz, R.; Rieta, JJ. (2021). Are Coronary Sinus Features Reflecting the Effect of Catheter Ablation of Atrial Fibrillation as P-waves Do?. IEEE. 1-4. https://doi.org/10.1109/EHB52898.2021.96576391

Is Short-Term Heart Rate Variability Good Enough to Predict Vascular Events in Hypertensive Patients?

[EN] Vascular events are the main cause of premature death and disability in the developed countries, where there is great interest in the development of computational tools for their early detection. A very relevant variable for their study is the heart rate, that can be analyzed through heart rate variability (HRV). Furthermore, high blood pressure is an important risk factor for most cardiovascular diseases. In fact, small reductions in blood pressure are known to markedly reduce cardiovascular morbidity and mortality. This study evaluates the predictive value of short-term HRV (STHRV) by developing models based on data mining algorithms to stratify the risk of vascular events from hypertensive patients. For this specific framework, the performance of various machine learning models (Random Forest, Support Vector Machines, Gaussian Naive Bayes, K-N Nearest Neighbours and Logistic regression), trained with different time lengths of 5, 30 and 60 minutes of HRV features during sleep stage was compared. The analyzed HRV parameters were associated to time, frequency and nonlinear features. A total of 139 Holter recordings from hypertensive patients of whom 17 developed a vascular event were analyzed. Results indicated that classification models developed using STHRV, with only 5 minutes length, provided similar or even better results than those developed with longer time series. Furthermore, the STHRV models provided a higher sensitivity and a slightly higher F1 score. The best one, based on Support Vector Machines, yielded 88.2% sensitivity and 75% F1 score. Thus, this research suggests the feasibility of STHRV analysis for risk stratification of hypertensive patients to anticipate serious vascular events.Research supported by grants DPI2017¿83952¿C3 from MINECO/AEI/FEDER UE, SBPLY/17/180501/000411 from JCCLM and AICO/2021/286 from GVA.Tornero, R.; Fácila, L.; Bertomeu-González, V.; Zangróniz, R.; Alcaraz, R.; Rieta, JJ. (2021). Is Short-Term Heart Rate Variability Good Enough to Predict Vascular Events in Hypertensive Patients?. IEEE. 1-4. https://doi.org/10.1109/EHB52898.2021.96576591

Hypertension Risk Assessment from Photoplethysmographic Recordings Using Deep Learning Classifiers

[EN] Regular monitoring of blood pressure (BP) is essential for early detection of cardiovascular diseases caused by hypertension, a potentially deadly condition without symptoms in its first stages. This study investigates whether deep learning techniques can assess risk levels of BP using only photoplethysmographic (PPG) recordings without the need of electrocardiographic (ECG) recordings, as in many previous studies. 15.240 segments from 50 different patients containing simultaneous PPG and arterial blood pressure (ABP) signals were analysed. GoogleNet and ResNet pretrained convolutional neural networks (CNN) with the scalogram of PPG signals obtained by continuous wavelet transform (CWT) used as input images were employed for the classification. The highest F1 score was achieved by discriminating normotensive (NT) patients from prehypertensive (PH) and hypertensive (HT), being 92.10% for GoogleNet and 93.91% for ResNet, respectively. In addition, intra-patient classification using different data segments for training and validation provided an F1 score of 90.28% with GoogleNet and 89.04% with ResNet. Time frequency transformation of PPG recordings to feed deep learning classifiers has been able to provide outstanding results in hypertension risk assessment without requiring either ECG recordings or feature extraction.Research supported by grants DPI2017-83952-C3 from MINECO/AEI/FEDER UE, SBPLY/17/180501/000411 from JCCLM and AICO/2021/286 from GVA.Cano, J.; Bertomeu-González, V.; Fácila, L.; Zangróniz, R.; Alcaraz, R.; Rieta, JJ. (2021). Hypertension Risk Assessment from Photoplethysmographic Recordings Using Deep Learning Classifiers. 1-4. https://doi.org/10.22489/CinC.2021.0311