Velázquez, Ramiro

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Real-Time Object Finding for the Visually Impaired Using an Image-to-Speech Wearable Device
(Springer Nature Switzerland, 2025-11-18)
Velázquez, Ramiro
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Edwige Pissaloux
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Del-Valle-Soto, Carolina
;
Claudia L. Garzón-Castro
;
Roberto de Fazio
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On Spatial Cognition and Mobility Strategies
(Springer Nature Switzerland, 2026)
Edwige Pissaloux
;
Velázquez, Ramiro
;
Simon Gay
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Haptic Technologies to Support Spatial Cognition and Mobility in Visually Impaired People
(Springer Nature Switzerland, 2026)
Edwige Pissaloux
;
Velázquez, Ramiro
;
Simon Gay
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Synchronous Acquisition and Processing of Electro- and Phono-Cardiogram Signals for Accurate Systolic Times’ Measurement in Heart Disease Diagnosis and Monitoring
(MDPI AG, 2025-07-06)
De Fazio Roberto
;
Ilaria Cascella
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Şule Esma Yalçınkaya
;
Massimo De Vittorio
;
Luigi Patrono
<jats:p>Cardiovascular diseases remain one of the leading causes of mortality worldwide, highlighting the importance of effective monitoring and early diagnosis. While electrocardiography (ECG) is the standard technique for evaluating the heart’s electrical activity and detecting rhythm and conduction abnormalities, it alone is insufficient for identifying certain conditions, such as valvular disorders. Phonocardiography (PCG) allows the recording and analysis of heart sounds and improves the diagnostic accuracy when combined with ECG. In this study, ECG and PCG signals were simultaneously acquired from a resting adult subject using a compact system comprising an analog front-end (model AD8232, manufactured by Analog Devices, Wilmington, MA, USA) for ECG acquisition and a digital stethoscope built around a condenser electret microphone (model HM-9250, manufactured by HMYL, Anqing, China). Both the ECG electrodes and the microphone were positioned on the chest to ensure the spatial alignment of the signals. An adaptive segmentation algorithm was developed to segment PCG and ECG signals based on their morphological and temporal features. This algorithm identifies the onset and peaks of S1 and S2 heart sounds in the PCG and the Q, R, and S waves in the ECG, enabling the extraction of the systolic time intervals such as EMAT, PEP, LVET, and LVST parameters proven useful in the diagnosis and monitoring of cardiovascular diseases. Based on the segmented signals, the measured averages (EMAT = 74.35 ms, PEP = 89.00 ms, LVET = 244.39 ms, LVST = 258.60 ms) were consistent with the reference standards, demonstrating the reliability of the developed method. The proposed algorithm was validated on synchronized ECG and PCG signals from multiple subjects in an open-source dataset (BSSLAB Localized ECG Data). The systolic intervals extracted using the proposed method closely matched the literature values, confirming the robustness across different recording conditions; in detail, the mean Q–S1 interval was 40.45 ms (≈45 ms reference value, mean difference: −4.85 ms, LoA: −3.42 ms and −6.09 ms) and the R–S1 interval was 14.09 ms (≈15 ms reference value, mean difference: −1.2 ms, LoA: −0.55 ms and −1.85 ms). In conclusion, the results demonstrate the potential of the joint ECG and PCG analysis to improve the long-term monitoring of cardiovascular diseases.</jats:p>
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A four-fingered robot hand with shape memory alloys
(2009)
Farias, Valerie
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Solis, Lucia
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Meléndez, Lorena
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García, Claudia
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Velázquez, Ramiro
Scopus© Citations 18 11 1
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Preface
(2023)
Papadopoulos, George Angelos
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Achilleos, Achilleas
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Pissaloux, Edwige
;
Velázquez, Ramiro
6 2
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Optimización del balanceo de un mecanismo plano mediante redistribución de masas
(2022)
Orvañanos-Guerrero, María T.
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Acevedo, Mario
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Sánchez-Gómez, Claudia
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Juan Cisneros-Barba
;
Miguel Carrasco
9 2
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Design and development of humanoid robot ZERO
(2011)
Efrain Hernandez
;
Velázquez, Ramiro
Scopus© Citations 3 5 1
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Leak Detection in Waterworks: Comparison Between STFT and FFT with an Overcoming of Limitations
(2017)
Aimé Lay-Ekuakille
;
Giuseppe Griffo
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Paolo Visconti
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Patrizio Primiceri
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Velázquez, Ramiro
<jats:title>Abstract</jats:title><jats:p>Detection of leakages in pipelines is a matter of continuous research because of the basic importance for a waterworks system is finding the point of the pipeline where a leak is located and − in some cases − a nature of the leak. There are specific difficulties in finding leaks by using spectral analysis techniques like FFT (Fast Fourier Transform), STFT (Short Term Fourier Transform), etc. These difficulties arise especially in complicated pipeline configurations, e.g. a zigzag one. This research focuses on the results of a new algorithm based on FFT and comparing them with a developed STFT technique. Even if other techniques are used, they are costly and difficult to be managed. Moreover, a constraint in the leak detection is the pipeline diameter because it influences accuracy of the adopted algorithm. FFT and STFT are not fully adequate for complex configurations dealt with in this paper, since they produce ill-posed problems with an increasing uncertainty. Therefore, an improved Tikhonov technique has been implemented to reinforce FFT and STFT for complex configurations of pipelines. Hence, the proposed algorithm overcomes the aforementioned difficulties due to applying a linear algebraic approach.</jats:p>
Scopus© Citations 8 39 1
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A Differential-Drive Mobile Robot Driven by an Ethology Inspired Behaviour Architecture
(2012)
Velázquez, Ramiro
;
Gutierrez, Carlos A.
34 1

Velázquez, Ramiro

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