25 research outputs found

    Frequency dependence of loop antenna H-Field in free-space

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    This paper investigates the effect of frequency on the magnetic field (H-field) strength at a specified distance from a single turn transmitting (TX) loop antenna in free-space. The H-field of a TX loop antenna in the Near Field (NF) region can be estimated using Biot-SavartĂą s Law (BSL). However, the BSL method is only valid for DC current flow and does not consider the effects of frequency on the H-field strength. This work introduces the frequency-dependent Antenna Near Field (ANF) method reported in the literature and compares this method against the BSL method and EM simulation results. It is shown that the ANF method can estimate the H-field magnitude with an error of less than 5% when compared with finite-element methods (FEM). In addition, the ANF method computes in a fraction of a second, whereas the FEM method takes several minutes to compute

    The CLARITY modular ambient health and wellness measurement platform

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    Emerging healthcare applications can benefit enormously from recent advances in pervasive technology and computing. This paper introduces the CLARITY Modular Ambient Health and Wellness Measurement Platform:, which is a heterogeneous and robust pervasive healthcare solution currently under development at the CLARITY Center for Sensor Web Technologies. This intelligent and context-aware platform comprises the Tyndall Wireless Sensor Network prototyping system, augmented with an agent-based middleware and frontend computing architecture. The key contribution of this work is to highlight how interoperability, expandability, reusability and robustness can be manifested in the modular design of the constituent nodes and the inherently distributed nature of the controlling software architecture.Emerging healthcare applications can benefit enormously from recent advances in pervasive technology and computing. This paper introduces the CLARITY Modular Ambient Health and Wellness Measurement Platform:, which is a heterogeneous and robust pervasive healthcare solution currently under development at the CLARITY Center for Sensor Web Technologies. This intelligent and context-aware platform comprises the Tyndall Wireless Sensor Network prototyping system, augmented with an agent-based middleware and frontend computing architecture. The key contribution of this work is to highlight how interoperability, expandability, reusability and robustness can be manifested in the modular design of the constituent nodes and the inherently distributed nature of the controlling software architecture

    Peri-operative red blood cell transfusion in neonates and infants: NEonate and Children audiT of Anaesthesia pRactice IN Europe: A prospective European multicentre observational study

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    BACKGROUND: Little is known about current clinical practice concerning peri-operative red blood cell transfusion in neonates and small infants. Guidelines suggest transfusions based on haemoglobin thresholds ranging from 8.5 to 12 g dl-1, distinguishing between children from birth to day 7 (week 1), from day 8 to day 14 (week 2) or from day 15 (≄week 3) onwards. OBJECTIVE: To observe peri-operative red blood cell transfusion practice according to guidelines in relation to patient outcome. DESIGN: A multicentre observational study. SETTING: The NEonate-Children sTudy of Anaesthesia pRactice IN Europe (NECTARINE) trial recruited patients up to 60 weeks' postmenstrual age undergoing anaesthesia for surgical or diagnostic procedures from 165 centres in 31 European countries between March 2016 and January 2017. PATIENTS: The data included 5609 patients undergoing 6542 procedures. Inclusion criteria was a peri-operative red blood cell transfusion. MAIN OUTCOME MEASURES: The primary endpoint was the haemoglobin level triggering a transfusion for neonates in week 1, week 2 and week 3. Secondary endpoints were transfusion volumes, 'delta haemoglobin' (preprocedure - transfusion-triggering) and 30-day and 90-day morbidity and mortality. RESULTS: Peri-operative red blood cell transfusions were recorded during 447 procedures (6.9%). The median haemoglobin levels triggering a transfusion were 9.6 [IQR 8.7 to 10.9] g dl-1 for neonates in week 1, 9.6 [7.7 to 10.4] g dl-1 in week 2 and 8.0 [7.3 to 9.0] g dl-1 in week 3. The median transfusion volume was 17.1 [11.1 to 26.4] ml kg-1 with a median delta haemoglobin of 1.8 [0.0 to 3.6] g dl-1. Thirty-day morbidity was 47.8% with an overall mortality of 11.3%. CONCLUSIONS: Results indicate lower transfusion-triggering haemoglobin thresholds in clinical practice than suggested by current guidelines. The high morbidity and mortality of this NECTARINE sub-cohort calls for investigative action and evidence-based guidelines addressing peri-operative red blood cell transfusions strategies. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT02350348

    Structure, activation and dysregulation of fibroblast growth factor receptor kinases: perspectives for clinical targeting

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    The receptor tyrosine kinase family of fibroblast growth factor receptors (FGFRs) play crucial roles in embryonic development, metabolism, tissue homeostasis and wound repair via stimulation of intracellular signalling cascades. As a consequence of FGFRs’ influence on cell growth, proliferation and differentiation, FGFR signalling is frequently dysregulated in a host of human cancers, variously by means of overexpression, somatic point mutations and gene fusion events. Dysregulation of FGFRs is also the underlying cause of many developmental dysplasias such as hypochondroplasia and achondroplasia. Accordingly, FGFRs are attractive pharmaceutical targets, and multiple clinical trials are in progress for the treatment of various FGFR aberrations. To effectively target dysregulated receptors, a structural and mechanistic understanding of FGFR activation and regulation is required. Here, we review some of the key research findings from the last couple of decades and summarise the strategies being explored for therapeutic intervention

    A tri-level current-steering DAC design with improved output-impedance related dynamic performance

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    This paper presents a design of a low-latency 12-bit linear tri-level current-steering digital-to-analogue-converter for use in continuous-time ADCs. The DAC design achieves 12-bit static linearity, while the combination of DAC slice impedance matching with a proposed compensation technique reduces output-impedance related distortion. The technique demonstrates ~10dB improvement in DAC dynamic performance at high frequencies over the Nyquist-band at 100MS/s. The DAC has been verified by simulation results in TSMC 1.2V 65nm CMOS technology

    Bandwidth enhancement to continuous-time input pipeline ADCs

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    This paper presents design analysis and insights for a new continuous-time input pipeline (CTIP) analog-to-digital converter (ADC) architecture that has enhanced bandwidth. An all-pass filter-based analog delay in the signal path allows bandwidth extension to Nyquist signal bandwidths. A resetting integrator gain stage provides a signal path delay helping to increase the bandwidth while reducing the power cost. The noise filtering property of the resetting integrator gain stage preserves the medium resistive input benefit of CTIP ADCs. The resetting integrator allows the architecture to be implemented with a feedforward compensated op-amp using low-voltage CMOS processes. This paper has been verified by simulation results of a CTIP ADC with 1.2-V supply voltage designed in TSMC's 65-nm CMOS technology

    The clarity modular ambient health and wellness measurement platform

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    Paper presented at the Fourth International Conference on Sensor Technologies and Applications (NetWare 2010 - SENSORCOMM 2010), Venice, Italy July 2010Emerging healthcare applications can benefit enormously from recent advances in pervasive technology and computing. This paper introduces the CLARITY Modular Ambient Health and Wellness Measurement Platform, which is a heterogeneous and robust pervasive healthcare solution currently under development at the CLARITY Center for Sensor Web Technologies. This intelligent and context-aware platform comprises the Tyndall Wireless Sensor Network prototyping system, augmented with an agent-based middleware and frontend computing architecture. The key contribution of this work is to highlight how interoperability, expandability, reusability and robustness can be manifested in the modular design of the constituent nodes and the inherently distributed nature of the controlling software architecture.Science Foundation IrelandConference detailshttp://www.iaria.org/conferences2010/SENSORCOMM10.htmlOn publication, swap submitted version with published version and add set text - contact AV - 7/10/2010. au ti ke SB. 11/10/201

    Analysis and design of a tri-level current-steering DAC with 12-bit linearity and improved impedance matching suitable for CT-ADCs

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    This paper presents the design of a low-latency, highly linear current-steering DAC for use in continuous-time ADCs. A detailed analysis of equivalent unary-weighted current-steering DAC topologies in terms of mismatch, noise, and output-impedance related distortion is carried out. From this analysis, we propose a tri-level DAC design that achieves 12-bit static linearity and is suitable for implementation in a continuous-time ADC architecture. To reduce output-impedance related distortion, the design combines DAC slice impedance matching with a proposed compensation technique. By incorporating the tri-level DAC in a continuous-time ADC architecture, the technique demonstrates ~ 8dB improvement in DAC dynamic performance at high frequencies over the Nyquist-band at 100MS/s. The DAC has been verified by simulation results in TSMC 1.2V 65nm CMOS technology

    Analysis of feedback predictive encoder based ADCs

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    Purpose The purpose of this paper is to present analysis of the feedback predictive encoder based ADC (Analog-to-Digital Converter). Design/methodology/approach The use of feedback predictive encoder based ADCs presents an alternative to the traditional two stage pipeline ADC by replacing the input estimate producing first stage of the pipeline, with a predictive loop that also produces an estimate of the input signal. Findings The overload condition for feedback predictive encoder ADCs is dependent on input signal amplitude and frequency, system gain and filter order. The limitation on the practical useable filter order is set by limit cycle oscillation. A boundary condition is defined for determination of maximum useable filter order. In a practical implementation of the predictive encoder ADC, the time allocated to the key functions of the gain stage and loop quantizer leads to optimisation of the power consumption. Practical implications A practical switched capacitor implementation of the predictive encoder based ADC is proposed. The power consumption of key circuit blocks is investigated. Originality/value This paper presents a methodology to optimise the bandwidth of predictive encoder ADCs. The overload and stability conditions may be used to determine the maximum input signal bandwidth for a given loop quantizer. Optimisation of power consumption based on the allocation of time between the gain stage and the SAR ADC operation is investigated. The lower bound of power consumption for this architecture is estimated
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