Experimental impulse radio IEEE 802.15.4a UWB based wireless sensor localization technology: Characterization, reliability and ranging

Ultra Wide Band (UWB) transmission has recently been the object of considerable attention in the field of next generation location aware wireless sensor networks. This is due to its fine time resolution, energy efficient and robustness to interference in harsh environments. This paper presents a thorough applied examination of prototype IEEE 802.15.4a impulse UWB transceiver technology to quantify the effect of line of sight (LOS) and non line of sight (NLOS) ranging in real indoor and outdoor environments. Results included draw on an extensive array of experiments that fully characterize the 802.15.4a UWB transceiver technology, its reliability and ranging capabilities for the first time. A new two way (TW) ranging protocol is proposed. The goal of this work is to validate the technology as a dependable wireless communications mechanism for the subset of sensor network localization applications where reliability and precision positions are key concerns.

The reliability mathematical model of load-sharing parallel systems based on fatigue cumulative damage

Conventional reliability models for parallel systems are not applicable for the analysis of parallel systems with load transfer and sharing. In this short communication, firstly, the dependent failures of parallel systems are analyzed, and the reliability model of load-sharing parallel system is presented based on Miner cumulative damage theory and the full probability formula. Secondly, the parallel system reliability is calculated by Monte Carlo simulation when the component life follows the Weibull distribution. The research result shows that the proposed reliability mathematical model could analyze and evaluate the reliability of parallel systems in the presence of load transfer.

Development and reliability of a direct access sensor using flip chip on flex technology with anisotropic conductive adhesive

Technological developments in biomedical microsystems are opening up new opportunities to improve healthcare procedures. Swallowable diagnostic sensing capsules are an example of these. In none of the diagnostic sensing capsules, is the sensor’s first level packaging achieved via Flip Chip Over Hole (FCOH) method using Anisotropic Conductive Adhesive (ACA). In a capsule application with direct access sensor (DAS), ACA not only provides the electrical interconnection but simultaneously seals the interconnect area and the underlying electronics. The development showed that the ACA FCOH was a viable option for the DAS interconnection. Adequate adhesive formed a strong joint that withstood a shear stress of 120N/mm2 and a compressive stress of 6N required to secure the final sensor assembly in place before encapsulation. Electrical characterization of the ACA joint in a fluid environment showed that the ACA was saturated with moisture and that the ions in the solution actively contributed to the leakage current, characterized by the varying rate of change of conductance. Long term hygrothermal aging of the ACA joint showed that a thermal strain of 0.004 and a hygroscopic strain of 0.0052 were present and resulted in a fatigue like process. In-vitro tests showed that high temperature and acidity had a deleterious effect of the ACA and its joint. It also showed that the ACA contact joints positioned at around or over 1mm would survive the gastrointestinal (GI) fluids and would be able to provide a reliable contact during the entire 72hr of the GI transit time. A final capsule demonstrator was achieved by successfully integrating the DAS, the battery and the final foldable circuitry into a glycerine capsule. Final capsule soak tests suggested that the silicone encapsulated system could survive the 72hr gut transition.

The inter-rater reliability of the Risk Instrument for Screening in the Community

Predicting risk of adverse healthcare outcomes is important to enable targeted delivery of interventions. The Risk Instrument for Screening in the Community (RISC), designed for use by public health nurses (PHNs), measures the one-year risk of hospitalisation, institutionalisation and death in community-dwelling older adults according to a five-point global risk score: from low (score 1,2), medium (3) and high (4,5). We examined the inter-rater reliability (IRR) of the RISC between student PHNs (n=32) and expert raters using six cases (two low, medium and high-risk), scored before and after RISC training. Correlations increased for each adverse outcome, statistically significantly for institutionalisation (r=0.72 to 0.80,p=0.04) and hospitalisation, (r=0.51 to 0.71,p<0.01) but not death. Training improved accuracy for low-risk but not all high-risk cases. Overall, the RISC showed good IRR, which increased after RISC training. That reliability reduced for some high-risk cases suggests that the training programme requires adjustment to further improve IRR.

Validation and reliability of the Japanese version of the Food Allergy Quality of Life Questionnaire - Parent Form

Background: Food allergy (FA) is a heavy burden for patients and their families and can significantly reduce the quality of life (QoL) of both. To provide adequate support, qualitative and quantitative evaluation of the parents' QoL may be helpful. The objective of this study is to develop and validate a Japanese version of the Food Allergy QoL QuestionnaireeParent Form (FAQLQ-PF-J), an internationally validated disease-specific QoL measurement of the parental burden of having a child with FA. Methods: The FAQLQ-PF and the Food Allergy Independent Measure (FAIM), an instrument to test the construct validity of the FAQLQ-PF-J, were translated into Japanese. After language validation, the questionnaires were administered to parents of FA children aged 0e12 years and those of age-matched healthy (without FA) children. Internal consistency (by Cronbach's a) and test-retest reliability were evaluated. Construct validity and discriminant validity were also examined. Results: One hundred twenty-seven parents of children with FA and 48 parents of healthy children filled out the questionnaire. The FAQLQ-PF-J showed excellent internal consistency (Cronbach's a > 0.77) and test-retest reliability. Good construct validity was demonstrated by significant correlations between the FAQLQ-PF-J and FAIM-J scores. It discriminated parents of children with FA from those without. The scores were significantly higher (lower QoL) for parents of FA children with a history of anaphylaxis than those without, for those with >6 FA-related symptoms experienced than those with less FA-related symptoms. Conclusions: The FAQLQ-PF-J is a reliable and valid measure of the parental burden of FA in children.