Low-Power Wearable ECG Monitoring System for Multiple-Patient Remote Monitoring

Many devices and solutions for remote electrocardiogram (ECG) monitoring have been proposed in the literature. These solutions typically have a large marginal cost per added sensor and are not seamlessly integrated with other smart home solutions. Here, we propose an ECG remote monitoring system that is dedicated to non-technical users in need of long-term health monitoring in residential environments and is integrated in a broader Internet-of-Things (IoT) infrastructure. Our prototype consists of a complete vertical solution with a series of advantages with respect to the state of the art, considering both the prototypes with integrated front end and prototypes realized with off-the-shelf components: 1) ECG prototype sensors with record-low energy per effective number of quantized levels; 2) an architecture providing low marginal cost per added sensor/user; and 3) the possibility of seamless integration with other smart home systems through a single IoT infrastructure

Last-Meter Smart Grid Embedded in an Internet-of-Things Platform

The customer domain of the smart grid natu- rally blends with smart home and smart building systems, but typical proposed approaches are “distributor-centric” rather than “customer-centric,” undermining user acceptance, and are often poorly scalable. To solve this problem, we propose a detailed architecture and an implementation of a “last-meter” smart grid—the portion of the smart grid on customer premises—embedded in an internet-of-things (IoT) platform. Our approach has four aspects of novelty and advantages with respect to the state of the art: 1) seamless integration of smart grid with smart home applications in the same infrastructure; 2) data gathering from heterogeneous sensor communication protocols; 3) secure and customized data access; and 4) univocal sensor and actuator mapping to a common abstraction layer on which additional concurrent applications can be built. A demonstrator has been built and tested with purposely-developed ZigBee smart meters and gateways, a distributed IoT server, and a flexible user interface

Derailment detection and data collection in freight trains, based on a wireless sensor network

We report the development of a network of wireless ultralow-power sensors to be deployed on freight railway cars, with the main purpose of detecting derailment events and alerting the engineer in the cab of the leading locomotive. Because no power bus is available on freight cars, we plan to rely on energy scavenging from vibrations; therefore, minimization of the power consumption has been one of our main priorities. We have, therefore, focused on ultralow-power hardware and strived to reduce the time intervals during which it is in active mode, achieving an average power consumption of ~0.5 mW with an active cycle of ~20 ms every 2 s. We discuss the overall concept that we propose, including the self-initialization protocol and the communication strategy that we have developed, and present the results of measurements on a prototype network that we have implemented

A comparison of some circuit schemes for semi-reversible adiabatic logic

Four flip-flop-like adiabatic logic circuits, suited for a standard cell library implementation, were compared in terms of absolute energy consumption and effectiveness of adiabatic energy recovery. The energy performance of ECRL, IECRL, PAL and PFAL logic circuits was determined, by means of SPICE simulation, as a function of capacitive load and operational frequency. The comparison showed that the PFAL circuit is the best flip-flop-based adiabatic solution as far as power consumption is concerned

Flexible polyimide electrodes for ECoG in chicken embryos

Electrocorticography (ECoG) is a valuable tool used to investigate brain activity with a better spatial resolution compared to the EEG system. We describe the fabrication of new polyimide electrodes for EcoG recording, used to research the development of wake-sleep cycles in chicken embryos. The microelectrodes are connected to a dedicated system for data acquisition. Current ECoG recordings in birds are usually made with metallic wire electrodes placed on the dura surface though a hole on the skull. This approach is not reliable for long term acquisitions (a few days) as the electrodes may generate signal artefacts and cause bleeding. Recently, flexible polymer electrodes have been proposed to avoid the stiffness of the metal wire and to improve compliance with brain surface. The electrodes are fabricated on a 75µm thick polyimide film substrate. Gold lines are used as conductive wires to read the brain potentials and transfer them to the acquisition system. To protect and isolate gold tracks, a protective spinnable polyimide layer (Hitachi PI2610) is subsequently deposited. Then, an aluminium hard mask is deposited and patterned by a lithographic step, to protect and to open a window by oxygen plasma etch in the protective layers, so that the gold pads are exposed. Finally, the electrodes are ready and are detached from the carrier tape. Preliminary insertion tests have showed the feasibility of flexible electrodes insertion in the chicken brain

Design of a nanopower current reference with reduced process variability

In this paper we present the design of a 0.18 mum CMOS current reference based on a variability-aware approach, in such a way to obtain a very low process sensitivity of the reference current. Its relative standard deviation is 1.4 % based on measurements performed over 23 samples from a single batch. The requirement of low process sensitivity is met together with the very low power consumption of 290 nW, at the cost of a large area occupation of 0.245 mm(2). Key to obtain this result are the use of the "classical" bipolar bandgap topology, which can be optimized for low-power/low-spread operation so as to outperform MOS-based bandgap circuits, and the use of devices that are intrinsically more stable towards process, such as diffusion resistors