Farid Touati

u-Healthcare system: state-of-the-art review and challenges.

With the increase of an ageing population and chronic diseases, society becomes more health conscious and patients become “health consumers” looking for better health management. People’s perception is shifting towards patient-centered, rather than the classical, hospital–centered health services which has been propelling the evolution of telemedicine research from the classic e-Health to m-Health and now is to ubiquitous healthcare (u-Health). It is expected that mobile & ubiquitous Telemedicine, integrated with Wireless Body Area Network (WBAN), have a great potential in fostering the provision of next-generation u-Health. Despite the recent efforts and achievements, current u-Health proposed solutions still suffer from shortcomings hampering their adoption today. This paper presents a comprehensive review of up-to-date requirements in hardware, communication, and computing for next-generation u-Health systems. It compares new technological and technical trends and discusses how they address expected u-Health requirements. A thorough survey on various worldwide recent system implementations is presented in an attempt to identify shortcomings in state-of-the art solutions. In particular, challenges in WBAN and ubiquitous computing were emphasized. The purpose of this survey is not only to help beginners with a holistic approach toward understanding u-Health systems but also present to researchers new technological trends and design challenges they have to cope with, while designing such systems.

Ultrahigh Aspect Ratio Copper-Nanowire-Based Hybrid Transparent Conductive Electrodes with PEDOT:PSS and Reduced Graphene Oxide Exhibiting Reduced Surface Roughness and Improved Stability.

UNLABELLED Copper nanowires (CuNWs) with ultrahigh aspect ratio are synthesized with a solution process and spray-coated onto select substrates to fabricate transparent conductive electrodes (TCEs). Different annealing methods are investigated and compared for effectiveness and convenience. The CuNWs are subsequently combined with the conductive polymer poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) ( PEDOT PSS) or with reduced graphene oxide (rGO) platelets in order to reduce the surface roughness and improve the durability of the fabricated TCEs. Our best-performing PEDOT PSS/CuNW films have optical transmittance T550 = 84.2% (at λ = 550 nm) and sheet resistance Rs = 25 Ω/sq, while our best CuNW/rGO films have T550 = 84% and Rs = 21.7 Ω/sq.

Study of the Effects of Dust, Relative Humidity, and Temperature on Solar PV Performance in Doha: Comparison Between Monocrystalline and Amorphous PVS

The sensitivity of various solar photovoltaic technologies to dust, temperature, and relative humidity is investigated for Dohas environment. Results obtained show that monocrystalline photovoltaics (PVs) have efficiencies as high as 85% compared to 70% for amorphous ones. Also, dust accumulation degrades more critically the efficiency of amorphous and monocrystalline silicon PVs than the panels temperature or relative humidity. In addition, the results show that amorphous PVs are more affected by temperature and relative humidity than monocrystalline PVs. However, amorphous PVs prove to be more robust against dust settlement than monocrystalline PVs and hence are more suitable for implementation in desert climates like Doha unless cleaning strategies are devised. It was estimated that 100 days of dust accumulation over monocrystalline PV panels, caused the efficiency to decrease by around 10%. This limitation makes solar PVs to represent an unreliable source of power for unattended or remote devices and thus strongly suggests the challenge of cleaning the panels surface regularly or injecting technical modifications. Furthermore, the study suggests operating solar PV plants in Doha from 11:00 am to 02:00 pm to optimize production.

Towards u-health: An indoor 6LoWPAN based platform for real-time healthcare monitoring

Ubiquitous healthcare is the key to handle the challenges of the growing population around the world. A variety of u-healthcare systems have been developed using various short-range technologies and proprietary protocols which include Zigbee and bluetooth. With all these protocols, interoperability of smart devices remains a challenge. 6LoWPAN as an open standard has recently evolved to provide one common platform on the top of IEEE802.15.4 for low power devices and to mitigate this interoperability problem. In this paper, we present a novel 6LoWPAN based communication platform for next-generation u-healthcare system. The system integrates three nodes forwarding data to an edge router in order to provide real-time monitoring of the patients ECG, temperature, and acceleration. A PC connected to the edge router acts as a two-directional Gateway between 6LoWPAN and internet. A new gateway application, listening to UDP packets from the 6LoWPAN nodes via the edge router along with any TCP client request from the internet, is developed. Thereby, any remote PC can connect to the gateway using TCP/IP by just connecting to the IP address and dedicated port of the gateway, fostering then ubiquity as well as Internet of Things. Nevertheless, the user can send instructions to any node where the application running on the gateway translates the command to a particular node. In our case, we used a Labview program to provide this connectivity. The whole system was tested successfully for different ECG rates using an ECG simulator. The received waveforms were found identical to those shown by a high-resolution scope wired to the ECG signals.

Towards understanding the effects of climatic and environmental factors on solar PV performance in arid desert regions (Qatar) for various PV technologies

The sensitivity of various solar photovoltaic technologies to dust, temperature and relative humidity is investigated for Qatars environment. Results obtained show that mono-crystalline PVs have efficiencies as high as 85% compared to 70% for amorphous ones. Also, dust accumulation degrades more critically the efficiency of amorphous and mono-crystalline silicon PVs than the panels temperature or relative humidity. In addition, the results show that amorphous PVs are more affected by temperature and relative humidity than mono-crystalline PVs. However, amorphous PVs prove to be more robust against dust settlement than mono-crystalline PVs and hence are more suitable for implementation in desert climates like Qatar unless cleaning strategies are devised. It was estimated that 100 days of dust accumulation over mono-crystalline PV panels, caused the efficiency to decrease by around 10%. This limitation makes solar PV an unreliable source of power for unattended or remote devices and thus strongly suggests the challenge of cleaning the panels surface regularly or injecting technical modifications. Furthermore, the study suggests operating solar PV plants in Qatar from 11:00 am to 02:00 pm to optimize production.

Mobile Robot Navigation Based on Q-Learning Technique

This paper shows how Q-learning approach can be used in a successful way to deal with the problem of mobile robot navigation. In real situations where a large number of obstacles are involved, normal Q-learning approach would encounter two major problems due to excessively large state space. First, learning the Q-values in tabular form may be infeasible because of the excessive amount of memory needed to store the table. Second, rewards in the state space may be so sparse that with random exploration they will only be discovered extremely slowly. In this paper, we propose a navigation approach for mobile robot, in which the prior knowledge is used within Q-learning. We address the issue of individual behavior design using fuzzy logic. The strategy of behaviors based navigation reduces the complexity of the navigation problem by dividing them in small actions easier for design and implementation. The Q-Learning algorithm is applied to coordinate between these behaviors, which make a great reduction in learning convergence times. Simulation and experimental results confirm the convergence to the desired results in terms of saved time and computational resources.

An Adaptive Control Scheme for Nonholonomic Mobile Robot with Parametric Uncertainty

This paper addresses the problem of stabilizing the dynamic model of a nonholonomic mobile robot. A discontinuous adaptive state feedback controller is derived to achieve global stability and convergence of the trajectories of the of the closed loop system in the presence of parameter modeling uncertainty. This task is achieved by a non smooth transformation in the original system followed by the derivation of a smooth time invariant control in the new coordinates. The stability and convergence analysis is built on Lyapunov stability theory.

A 3G/WiFi-enabled 6LoWPAN-based U-healthcare system for ubiquitous real-time monitoring and data logging

Ubiquitous healthcare (U-healthcare) systems are expected to offer flexible and resilient high-end technological solutions enabling remote monitoring of patients health status in real-time and provisioning of feedback and remote actions by healthcare providers. In this paper, we present a 6LowPAN based U-healthcare platform that contributes to the realization of the above expectation. The proposed system comprises two sensor nodes sending temperature data and ECG signals to a remote processing unit. These sensors are being assigned an IPv6 address to enable the Internet-of-Things (IoT) functionality. A 6LowPAN-enabled edge router, connected to a PC, is serving as a base station through a serial interface, to collect data from the sensor nodes. Furthermore, a program interfacing through a Serial-Line-Internet-Protocol (SLIP) and running on the PC provides a network interface that receives IPv6 packets from the edge router. The above system is enhanced by having the application save readings from the sensors into a file that can be downloaded by a remote server using a free Cloud service such as UbuntuOne. This enhancement makes the system robust against data loss especially for outdoor healthcare services, where the 3G/4G connectivity may get lost because of signal quality fluctuations. The system provided a proof of concept of successful remote U-healthcare monitoring illustrating the IoT functionality and involving 3G/4G connectivity while being enhanced by a cloud-based backup.

A comparative analysis of BLE and 6LoWPAN for U-HealthCare applications

For decades, there exist a variety of low-power wireless technologies deployed for healthcare applications such as Zigbee/IEEE802.15.4, Bluetooth, ANT, NFC, IrDA. However, the recently announced Bluetooth Low Energy (BLE) technology claims to offer many new compelling features and is expected to get wide adoption by many mobile manufacturers around the world and hence be included in daily life mobile devices. Therefore, it is important to provide future adopters with a thorough yet insightful evaluation of this technology as contrasted to competing ones in the market today. In this paper, we present such evaluation from an experimental point of view as well as referring to technical specifications from manufacturers. The discussion is geared toward assessing the extent to which theses technologies can meet the stringent requirements for u-healthcare applicability. BLE and 6LoWPAN showed greater potentials for such applicability in terms of power demand, bit rate and latency. Nevertheless, BLE was found to be most robust to obstacles and was operable using single coin cell.

Surface-type nonvolatile electric memory elements based on organic-on-organic CuPc-H2Pc heterojunction*

A novel surface-type nonvolatile electric memory elements based on organic semiconductors CuPc and H2Pc are fabricated by vacuum deposition of the CuPc and H2Pc films on preliminary deposited metallic (Ag and Cu) electrodes. The gap between Ag and Cu electrodes is 30–40 μm. For the current–voltage (I–V) characteristics the memory effect, switching effect, and negative differential resistance regions are observed. The switching mechanism is attributed to the electric-field-induced charge transfer. As a result the device switches from a low to a high-conductivity state and then back to a low conductivity state if the opposite polarity voltage is applied. The ratio of resistance at the high resistance state to that at the low resistance state is equal to 120–150. Under the switching condition, the electric current increases ~ 80–100 times. A comparison between the forward and reverse I–V characteristics shows the presence of rectifying behavior.