Publications de Ruben Braojos Lopez

Analysis of Functional Errors Produced by Long-Term Workload-Dependent BTI Degradation in Ultra-Low Power Processors

David Atienza Alonso, Ruben Braojos Lopez, Loris Gérard Duch, Miguel Peon Quiros, Alexandre Sébastien Julien Levisse

Aging effects in digital circuits change the switching characteristics of their transistors, resulting in timing violations that can lead to functional errors at the system level. In particular, BTI is a degradation effect that changes the threshold voltag ...

2020

An Inexact Ultra-low Power Bio-signal Processing Architecture With Lightweight Error Recovery

David Atienza Alonso, Ruben Braojos Lopez, Soumya Subhra Basu, Giovanni Ansaloni, Loris Gérard Duch

The energy efficiency of digital architectures is tightly linked to the voltage level (Vdd) at which they operate. Aggressive voltage scaling is therefore mandatory when ultra-low power processing is required. Nonetheless, the lowest admissible Vdd is ofte ...

Assoc Computing Machinery2017

An Inexact Ultra-low Power Bio-signal Processing Architecture With Lightweight Error Recovery

David Atienza Alonso, Ruben Braojos Lopez, Soumya Subhra Basu, Giovanni Ansaloni, Loris Gérard Duch

The energy e fficiency of digital architectures is tightly linked to the voltage level (Vdd) at which they operate. Aggressive voltage scaling is therefore mandatory when ultra-low power processing is required. Nonetheless, the lowest admissible Vdd is o e ...

2017

A Synchronization-Based Hybrid-Memory Multi-Core Architecture for Energy-Efficient Biomedical Signal Processing

David Atienza Alonso, Luca Benini, Ruben Braojos Lopez, Giovanni Ansaloni

In the last decade, improvements on technology scaling have enabled the design of a novel generation of wearable bio-sensing monitors. These smart Wireless Body Sensor Nodes (WBSNs) are able to acquire and process biological signals, such as electrocardiog ...

Institute of Electrical and Electronics Engineers2017

HEAL-WEAR: an Ultra-Low Power Heterogeneous System for Bio-Signal Analysis

David Atienza Alonso, Ruben Braojos Lopez, Soumya Subhra Basu, Giovanni Ansaloni, Loris Gérard Duch

Personalized healthcare devices enable low-cost, unobtrusive and long-term acquisition of clinically-relevant biosignals. These appliances, termed Wireless Body Sensor Nodes (WBSNs), are fostering a revolution in health monitoring for patients affected by ...

Ieee-Inst Electrical Electronics Engineers Inc2017

A Multi-Core Reconfigurable Architecture for Ultra-Low Power Bio-Signal Analysis

David Atienza Alonso, Ruben Braojos Lopez, Soumya Subhra Basu, Giovanni Ansaloni, Loris Gérard Duch

This paper introduces a novel computing architecture devoted to the ultra-low power analysis of multiple bio-signals. Its structure comprises several processors interfaced with a shared acceleration resource, implemented as a Coarse Grained Reconfigurable ...

2016

An Ultra-Low Power NVM-Based Multi-Core Architecture for Embedded Bio Signal Processing

David Atienza Alonso, Ruben Braojos Lopez

Healthcare delivery is evolving towards new Wireless Body Sensor Nodes (WBSN), which are miniaturized devices able to acquire, process and transmit subjects’ bio-signals in real time within a tiny energy budget. Recent efforts on AD converters and transmis ...

2016

Hardware/Software Co-Design of Ultra-Low Power Biomedical Monitors

Ruben Braojos Lopez

Ongoing changes in world demographics and the prevalence of unhealthy lifestyles are imposing a paradigm shift in healthcare delivery. Nowadays, chronic ailments such as cardiovascular diseases, hypertension and diabetes, represent the most common causes o ...

EPFL2016

Nano-Engineered Architectures for Ultra-Low Power Wireless Body Sensor Nodes

David Atienza Alonso, Mohamed Mostafa Sabry Aly, Ruben Braojos Lopez, Giovanni Ansaloni, Subhasish Mitra

Wireless body sensor nodes (WBSNs) are miniaturized devices that are able to acquire, process and transmit bio-signals (such as electrocardiograms, respiration or human-body kinetics). WBSNs face major design challenges due to extremely limited power budge ...

Assoc Computing Machinery2016

Method for detecting abnormalities in an electrocardiogram

David Atienza Alonso, Srinivasan Murali, Francisco Javier Rincon Vallejos, Ruben Braojos Lopez, Giovanni Ansaloni

A method for classification of ECG beats into normal and different categories of abnormal beats. The method comprises the following steps, performed on a computing platform: a. performing a training phase comprising taking as an input one or more ECG beats ...

2015

Hardware/Software Approach for Code Synchronization in Low-Power Multi-Core Sensor Nodes

David Atienza Alonso, Ruben Braojos Lopez, Ivan Beretta, Giovanni Ansaloni

Latest embedded bio-signal analysis applications, targeting low-power Wireless Body Sensor Nodes (WBSNs), present conflicting requirements. On one hand, bio-signal analysis applications are continuously increasing their demand for high computing capabiliti ...

IEEE/ACM Press2014

Early Classification of Pathological Heartbeats on Wireless Body Sensor Nodes

David Atienza Alonso, Ruben Braojos Lopez, Ivan Beretta, Giovanni Ansaloni

Smart Wireless Body Sensor Nodes (WBSNs) are a novel class of unobtrusive, battery-powered devices allowing the continuous monitoring and real-time interpretation of a subject's bio-signals, such as the electrocardiogram (ECG). These low-power platforms, w ...

MDPI2014

Ultra-Low Power Design of Wearable Cardiac Monitoring Systems

David Atienza Alonso, Srinivasan Murali, Francisco Javier Rincon Vallejos, Hossein Mamaghanian, Ruben Braojos Lopez, Giovanni Ansaloni, Alair Dias Junior

This paper presents the system-level architecture of novel ultra-low power wireless body sensor nodes (WBSNs) for real-time cardiac monitoring and analysis, and discusses the main design challenges of this new generation of medical devices. In particular, ...

IEEE2014

Risk Assessment of Atrial Fibrillation: a Failure Prediction Approach

David Atienza Alonso, Ruben Braojos Lopez, Daniel Camilo Rojas Quirós, Giovanni Ansaloni

We present a methodology for identifying patients who have experienced Paroxysmal Atrial Fibrillation (PAF) among a given subject population. Our work is intended as an initial step towards the design of an unobtrusive portable system for concurrent detect ...

Institute of Electrical and Electronics Engineers2014

Ultra-Low Power Design of Wearable Cardiac Monitoring Systems

David Atienza Alonso, Srinivasan Murali, Francisco Javier Rincon Vallejos, Hossein Mamaghanian, Ruben Braojos Lopez, Giovanni Ansaloni, Alair Dias Junior

This paper presents the system-level architecture of novel ultra-low power wireless body sensor nodes (WBSNs) for real-time cardiac monitoring and analysis, and discusses the main design challenges of this new generation of medical devices. In particular, ...

IEEE/ACM Press2014

A Methodology for Embedded Classification of Heartbeats Using Random Projections

David Atienza Alonso, Ruben Braojos Lopez, Giovanni Ansaloni

Smart Wireless Body Sensor Nodes (WBSNs) are a novel class of unobtrusive, battery-powered devices allowing the continuous monitoring and real-time interpretation of a subject’s bio-signals. One of its most relevant applications is the acquisition and anal ...

2013

Synchronizing Code Execution on Ultra-Low-Power Embedded Multi-Channel Signal Analysis Platforms

David Atienza Alonso, Ahmed Yasir Dogan, Andreas Peter Burg, Ruben Braojos Lopez, Jeremy Hugues-Felix Constantin, Giovanni Ansaloni

Embedded biosignal analysis involves a considerable amount of parallel computations, which can be exploited by employing low-voltage and ultra-low-power (ULP) parallel computing architectures. By allowing data and instruction broadcasting, single instructi ...

2013

Embedded Real-Time ECG Delineation Methods: a Comparative Evaluation

David Atienza Alonso, Francisco Javier Rincon Vallejos, Ruben Braojos Lopez, Giovanni Ansaloni

Wireless sensor nodes (WSNs) have recently evolved to include a fair amount of computational power, so that advanced signal processing algorithms can now be embedded even in this extremely low-power platforms. An increasingly successful field of applicatio ...

IEEE Press2012