Now showing 1 - 10 of 158
No Thumbnail Available
Publication

Wearable electronic tactile display for the foot

2013-04-05 , Velázquez, Ramiro , Bazan, Oma , Varona, Jorge

No Thumbnail Available
Publication

Sensors Allocation and Observer Design for Discrete Bilateral Teleoperation Systems with Multi-Rate Sampling

2022 , Amir Aminzadeh Ghavifekr , Roberto De Fazio , Velázquez, Ramiro , Paolo Visconti

This study addresses sensor allocation by analyzing exponential stability for discrete-time teleoperation systems. Previous studies mostly concentrate on the continuous-time teleoperation systems and neglect the management of significant practical phenomena, such as data-swap, the effect of sampling rates of samplers, and refresh rates of actuators on the system’s stability. A multi-rate sampling approach is proposed in this study, given the isolation of the master and slave robots in teleoperation systems which may have different hardware restrictions. This architecture collects data through numerous sensors with various sampling rates, assuming that a continuous-time controller stabilizes a linear teleoperation system. The aim is to assign each position and velocity signals to sensors with different sampling rates and divide the state vector between sensors to guarantee the stability of the resulting multi-rate sampled-data teleoperation system. Sufficient Krasovskii-based conditions will be provided to preserve the exponential stability of the system. This problem will be transformed into a mixed-integer program with LMIs (linear matrix inequalities). These conditions are also used to design the observers for the multi-rate teleoperation systems whose estimation errors converge exponentially to the origin. The results are validated by numerical simulations which are useful in designing sensor networks for teleoperation systems.

No Thumbnail Available
Publication

Performance of MRC Detection in OFDM System with Virtual Carriers over V2V Channels

2019 , Del-Puerto-Flores, J. Alberto , Joaquin Cortez , Gutierrez, Carlos A. , Del-Valle-Soto, Carolina , Velázquez, Ramiro , Valdivia, Leonardo

No Thumbnail Available
Publication

Development of a Self-Powered Piezo-Resistive Smart Insole Equipped with Low-Power BLE Connectivity for Remote Gait Monitoring

2021 , Roberto de Fazio , Elisa Perrone , Velázquez, Ramiro , Massimo De Vittorio , Paolo Visconti

The evolution of low power electronics and the availability of new smart materials are opening new frontiers to develop wearable systems for medical applications, lifestyle monitoring, and performance detection. This paper presents the development and realization of a novel smart insole for monitoring the plantar pressure distribution and gait parameters; indeed, it includes a piezoresistive sensing matrix based on a Velostat layer for transducing applied pressure into an electric signal. At first, an accurate and complete characterization of Velostat-based pressure sensors is reported as a function of sizes, support material, and pressure trend. The realization and testing of a low-cost and reliable piezoresistive sensing matrix based on a sandwich structure are discussed. This last is interfaced with a low power conditioning and processing section based on an Arduino Lilypad board and an analog multiplexer for acquiring the pressure data. The insole includes a 3-axis capacitive accelerometer for detecting the gait parameters (swing time and stance phase time) featuring the walking. A Bluetooth Low Energy (BLE) 5.0 module is included for transmitting in real-time the acquired data toward a PC, tablet or smartphone, for displaying and processing them using a custom Processing® application. Moreover, the smart insole is equipped with a piezoelectric harvesting section for scavenging energy from walking. The onfield tests indicate that for a walking speed higher than 1 ms−1, the device’s power requirements (i.e., P¯=5.84 mW) was fulfilled. However, more than 9 days of autonomy are guaranteed by the integrated 380-mAh Lipo battery in the total absence of energy contributions from the harvesting section.

No Thumbnail Available
Publication

A Comprehensive Review of Behavior Change Techniques in Wearables and IoT: Implications for Health and Well-Being

2024 , Del-Valle-Soto, Carolina , López-Pimentel, Juan Carlos , Vázquez Castillo, Javier , Nolazco Flores, Juan Arturo , Velázquez, Ramiro , José Varela-Aldás , Visconti, Paolo

This research paper delves into the effectiveness and impact of behavior change techniques fostered by information technologies, particularly wearables and Internet of Things (IoT) devices, within the realms of engineering and computer science. By conducting a comprehensive review of the relevant literature sourced from the Scopus database, this study aims to elucidate the mechanisms and strategies employed by these technologies to facilitate behavior change and their potential benefits to individuals and society. Through statistical measurements and related works, our work explores the trends over a span of two decades, from 2000 to 2023, to understand the evolving landscape of behavior change techniques in wearable and IoT technologies. A specific focus is placed on a case study examining the application of behavior change techniques (BCTs) for monitoring vital signs using wearables, underscoring the relevance and urgency of further investigation in this critical intersection of technology and human behavior. The findings shed light on the promising role of wearables and IoT devices for promoting positive behavior modifications and improving individuals’ overall well-being and highlighting the need for continued research and development in this area to harness the full potential of technology for societal benefit.

No Thumbnail Available
Publication

Special issue on EnvIMEKO 2017

2020 , Velázquez, Ramiro , Aime' Lay-Ekuakille

No Thumbnail Available
Publication

An optimal adaptive filtering approach for stress-tests motion artifacts removal: application on an ECG for telediagnosis

2002 , Velázquez, Ramiro

No Thumbnail Available
Publication

THE TACTOBOOK: A PORTABLE ELECTRONIC TACTILE READING DEVICE FOR THE BLIND

2007 , Velázquez, Ramiro , Edwige E. Pissaloux

No Thumbnail Available
Publication

An Innovative Tool for Detection of Small Notches Using a Nanocomposite Optical Sensor

2016 , Nicola Ivan Giannoccaro , Aime Lay-Ekuakille , Luigi Spedicato , Alessandro Massaro , Velázquez, Ramiro

No Thumbnail Available
Publication

Active vibration in civil structures using negative acceleration feedback

2017 , Josue Enriquez-Zarate , Velázquez, Ramiro , Gerardo Silva-Navarro