Future of smart cardiovascular implants

Cardiovascular disease remains the leading cause of death in Western society. Recent technological advances have opened the opportunity of developing new and innovative smart stent devices that have advanced electrical properties that can improve diagnosis and even treatment of previously intractable conditions, such as central line access failure, atherosclerosis and reporting on vascular grafts for renal dialysis. Here we review the latest advances in the field of cardiovascular medical implants, providing a broad overview of the application of their use in the context of cardiovascular disease rather than an in-depth analysis of the current state of the art. We cover their powering, communication and the challenges faced in their fabrication. We focus specifically on those devices required to maintain vascular access such as ones used to treat arterial disease, a major source of heart attacks and strokes. We look forward to advances in these technologies in the future and their implementation to improve the human condition

Synchronous wearable wireless body sensor network composed of autonomous textile nodes

A novel, fully-autonomous, wearable, wireless sensor network is presented, where each flexible textile node performs cooperative synchronous acquisition and distributed event detection. Computationally efficient situational-awareness algorithms are implemented on the low-power microcontroller present on each flexible node. The detected events are wirelessly transmitted to a base station, directly, as well as forwarded by other on-body nodes. For each node, a dual-polarized textile patch antenna serves as a platform for the flexible electronic circuitry. Therefore, the system is particularly suitable for comfortable and unobtrusive integration into garments. In the meantime, polarization diversity can be exploited to improve the reliability and energy-efficiency of the wireless transmission. Extensive experiments in realistic conditions have demonstrated that this new autonomous, body-centric, textile-antenna, wireless sensor network is able to correctly detect different operating conditions of a firefighter during an intervention. By relying on four network nodes integrated into the protective garment, this functionality is implemented locally, on the body, and in real time. In addition, the received sensor data are reliably transferred to a central access point at the command post, for more detailed and more comprehensive real-time visualization. This information provides coordinators and commanders with situational awareness of the entire rescue operation. A statistical analysis of measured on-body node-to-node, as well as off-body person-to-person channels is included, confirming the reliability of the communication system

A GPP-Based Software-Defined Radio Front-End for WLAN Standards

This paper presents a software-defined radio testbed for the physical layer of wireless LAN standards. All baseband physical layer functions have been successfully mapped on a Pentium 4 processor that performs these functions in real-time. This has been tested in combination with a CMOS integrated wideband analog front-end containing a low noise amplifier, downconversion mixers and filters. The testbed consists of both a transmitter and a receiver. The transmitter contains a transmitter PC with a DAC board, an Agilent E4438C generator for upconversion and an antenna. The receiver consists of an antenna, a wideband SDR analog frontend and a receiver PC with an ADC board. On this testbed we have implemented two different types of standards, a continuous-phase-modulation based standard, Bluetooth and an OFDM based standard, HiperLAN/2. However, our testbed can easily be extended to other standards, because the only limitations in our testbed are the maximal channel bandwidth of 20 MHz, the dynamic range of the wideband SDR analog front-end and of course the processing capabilities of the used PC

Mobile telephony - cooperation and value-added are key to further success

The current problems in mobile telephony are leading critics to make overly pessimistic predictions that 3G – the third-generation mobile phone system – will never become profitable. However, the resulting calls not to introduce 3G and instead directly back alternative wireless technologies (e.g. WLAN) are a step too far. Ultimately, a profit- oriented service can only create significant value-added with a mix of both 3G and WLAN technologies. It is notable that no attractive broadband-dependent applications have emerged as yet. The typical user is only interested in the value-added the application provides, not the underlying wireless technology. Although mobile telephony remains one of the most dynamic areas of the economy, euphoria is misplaced. Advanced wireless technologies will on no account become profitable before the start of the next decade. But even that is not a given; this will challenge the entrepreneurial spirit of network operators, mobile terminal manufacturers and service providers alike.ICT, IT, mobile, telephony, UMTS, WLAN

Efficient DSP and Circuit Architectures for Massive MIMO: State-of-the-Art and Future Directions

Massive MIMO is a compelling wireless access concept that relies on the use of an excess number of base-station antennas, relative to the number of active terminals. This technology is a main component of 5G New Radio (NR) and addresses all important requirements of future wireless standards: a great capacity increase, the support of many simultaneous users, and improvement in energy efficiency. Massive MIMO requires the simultaneous processing of signals from many antenna chains, and computational operations on large matrices. The complexity of the digital processing has been viewed as a fundamental obstacle to the feasibility of Massive MIMO in the past. Recent advances on system-algorithm-hardware co-design have led to extremely energy-efficient implementations. These exploit opportunities in deeply-scaled silicon technologies and perform partly distributed processing to cope with the bottlenecks encountered in the interconnection of many signals. For example, prototype ASIC implementations have demonstrated zero-forcing precoding in real time at a 55 mW power consumption (20 MHz bandwidth, 128 antennas, multiplexing of 8 terminals). Coarse and even error-prone digital processing in the antenna paths permits a reduction of consumption with a factor of 2 to 5. This article summarizes the fundamental technical contributions to efficient digital signal processing for Massive MIMO. The opportunities and constraints on operating on low-complexity RF and analog hardware chains are clarified. It illustrates how terminals can benefit from improved energy efficiency. The status of technology and real-life prototypes discussed. Open challenges and directions for future research are suggested.Comment: submitted to IEEE transactions on signal processin

4. generációs mobil rendszerek kutatása = Research on 4-th Generation Mobile Systems

A 3G mobil rendszerek szabványosítása a végéhez közeledik, legalábbis a meghatározó képességek tekintetében. Ezért létfontosságú azon technikák, eljárások vizsgálata, melyek a következő, 4G rendszerekben meghatározó szerepet töltenek majd be. Több ilyen kutatási irányvonal is létezik, ezek közül projektünkben a fontosabbakra koncentráltunk. A következőben felsoroljuk a kutatott területeket, és röviden összegezzük az elért eredményeket. Szórt spektrumú rendszerek Kifejlesztettünk egy új, rádiós interfészen alkalmazható hívásengedélyezési eljárást. Szimulációs vizsgálatokkal támasztottuk alá a megoldás hatékonyságát. A projektben kutatóként résztvevő Jeney Gábor sikeresen megvédte Ph.D. disszertációját neurális hálózatokra épülő többfelhasználós detekciós technikák témában. Az elért eredmények Imre Sándor MTA doktori disszertációjába is beépültek. IP alkalmazása mobil rendszerekben Továbbfejlesztettük, teszteltük és általánosítottuk a projekt keretében megalkotott új, gyűrű alapú topológiára épülő, a jelenleginél nagyobb megbízhatóságú IP alapú hozzáférési koncepciót. A témakörben Szalay Máté Ph.D. disszertációja már a nyilvános védésig jutott. Kvantum-informatikai módszerek alkalmazása 3G/4G detekcióra Új, kvantum-informatikai elvekre épülő többfelhasználós detekciós eljárást dolgoztunk ki. Ehhez új kvantum alapú algoritmusokat is kifejlesztettünk. Az eredményeket nemzetközi folyóiratok mellett egy saját könyvben is publikáltuk. | The project consists of three main research directions. Spread spectrum systems: we developed a new call admission control method for 3G air interfaces. Project member Gabor Jeney obtained the Ph.D. degree and project leader Sandor Imre submitted his DSc theses from this area. Application of IP in mobile systems: A ring-based reliable IP mobility mobile access concept and corresponding protocols have been developed. Project member Máté Szalay submitted his Ph.D. theses from this field. Quantum computing based solutions in 3G/4G detection: Quantum computing based multiuser detection algorithm was developed. Based on the results on this field a book was published at Wiley entitled: 'Quantum Computing and Communications - an engineering approach'

A programmable microsystem using system-on-chip for real-time biotelemetry

A telemetry microsystem, including multiple sensors, integrated instrumentation and a wireless interface has been implemented. We have employed a methodology akin to that for System-on-Chip microelectronics to design an integrated circuit instrument containing several "intellectual property" blocks that will enable convenient reuse of modules in future projects. The present system was optimized for low-power and included mixed-signal sensor circuits, a programmable digital system, a feedback clock control loop and RF circuits integrated on a 5 mm × 5 mm silicon chip using a 0.6 μm, 3.3 V CMOS process. Undesirable signal coupling between circuit components has been investigated and current injection into sensitive instrumentation nodes was minimized by careful floor-planning. The chip, the sensors, a magnetic induction-based transmitter and two silver oxide cells were packaged into a 36 mm × 12 mm capsule format. A base station was built in order to retrieve the data from the microsystem in real-time. The base station was designed to be adaptive and timing tolerant since the microsystem design was simplified to reduce power consumption and size. The telemetry system was found to have a packet error rate of 10<sup>-</sup><sup>3</sup> using an asynchronous simplex link. Trials in animal carcasses were carried out to show that the transmitter was as effective as a conventional RF device whilst consuming less power

Energy-efficient wireless communication

In this chapter we present an energy-efficient highly adaptive network interface architecture and a novel data link layer protocol for wireless networks that provides Quality of Service (QoS) support for diverse traffic types. Due to the dynamic nature of wireless networks, adaptations in bandwidth scheduling and error control are necessary to achieve energy efficiency and an acceptable quality of service. In our approach we apply adaptability through all layers of the protocol stack, and provide feedback to the applications. In this way the applications can adapt the data streams, and the network protocols can adapt the communication parameters

Wireless sensors and IoT platform for intelligent HVAC control

Energy consumption of buildings (residential and non-residential) represents approximately 40% of total world electricity consumption, with half of this energy consumed by HVAC systems. Model-Based Predictive Control (MBPC) is perhaps the technique most often proposed for HVAC control, since it offers an enormous potential for energy savings. Despite the large number of papers on this topic during the last few years, there are only a few reported applications of the use of MBPC for existing buildings, under normal occupancy conditions and, to the best of our knowledge, no commercial solution yet. A marketable solution has been recently presented by the authors, coined the IMBPC HVAC system. This paper describes the design, prototyping and validation of two components of this integrated system, the Self-Powered Wireless Sensors and the IOT platform developed. Results for the use of IMBPC in a real building under normal occupation demonstrate savings in the electricity bill while maintaining thermal comfort during the whole occupation schedule.QREN SIDT [38798]; Portuguese Foundation for Science & Technology, through IDMEC, under LAETA [ID/EMS/50022/2013

Design and development of thermoelectric powered wireless sensor network using soft start approach

Wireless Sensor Networks (WSNs) mainly comprise of a large number of spatially distributed low-power autonomous nodes (SNs) equipped with sensors to cooperatively monitor the environmental conditions. The limited battery lifespan that is being used to operate a sensor node is the major bottleneck that restricts the extension of WSN application. The motivation of this research project s using Thermoelectric Generator (TEG) to harvest the heat energy and convert the heat energy into electrical energy for powering a sensor node. However, the energy harvested by the TEG is too small and insufficient to power up the sensor node as it is relatively power hungry. In addition, there is a power mismatch between the supply energy produced by the TEG and the energy needed by the node to carry out the required tasks. Therefore, the objective of this research project is to develop a low power management system in enabling TEG powered wireless sensor nodes to be operated smoothly. In the experiment, a TEG was sandwiched between a heating element and a heat sink in order to produce a temperature gradient between the TEG with a range between 5°C and 30°C, Then, two power management systems using two different integrated circuits of LTC3108 and MAX757 respectively were compared. Moreover, two soft start circuits based on TC54 and LM741 respectively were designed and compared in terms of sensitivity and charging time, discharging time during the operation a sensor node. These two circuits were implemented in between the capacitor storage and the sensor node. The result proved that the output voltage of TEG is boosted up using LTC3108 and MAX757 t0 3.326V and 3.382V respectively and the maximum power output of TEG is around 29.48mW. Besides, it s also shown that the capacitor voltage (Vcs) for the proposed soft start circuit can be increased up 10 3.3V with a charging time around 20s. It is also act to isolate the capacitor storage with sensor node during the charging process and activation of the sensor node. The charging time for the capacitor storage is 0.2s and the discharging time is about 4s. During the discharging time, the node is in sleep mode. This allows the power management circuit to accumulate enough of power for the next active period. The sensor node based on CC2650 consumed 22.28mW during the data transmission, while consumed 0.11mW during the sleep ‘mode, Thus, it shows that the automatic power management for a sensor node is achicvable with soft-start system which overcomes the start-up problem every time a storage capacitor has been completely discharged