Cyber-Physical Systems: two case studies in design methodologies

To analyze embedded systems, engineers use tools that can simulate the performance of software components executed on hardware architectures. When the embedded system functionality is strongly correlated to physical quantities, as in the case of Cyber-Physical System (CPS), we need to model physical processes to determine the overall behavior of the system. Unfortunately, embedded systems simulators are not generally suitable to evaluate physical processes, and in the same way physical model simulators hardly capture the functionality of computing systems. In this work, we present a methodology to concurrently explore these aspects using the metroII design framework. The methodology provides guidelines for the implementation of these models in the design environment. To demonstrate the feasibility of the proposed approach, we applied the methodology to two case studies. A case study regards a binaural guidance system developed to be included into a smart rollator for older adults. The second case consists of an energy recovery device which gets energy from the heat dissipated by a high performance processor and power a smart sink able to provide cooling or to serve as a wireless sensing node

Self-Powered WSN for Distributed Data Center Monitoring

Monitoring environmental parameters in data centers is gathering nowadays increasing attention from industry, due to the need of high energy efficiency of cloud services. We present the design and the characterization of an energy neutral embedded wireless system, prototyped to monitor perpetually environmental parameters in servers and racks. It is powered by an energy harvesting module based on Thermoelectric Generators, which converts the heat dissipation from the servers. Starting from the empirical characterization of the energy harvester, we present a power conditioning circuit optimized for the specific application. The whole system has been enhanced with several sensors. An ultra-low-power micro-controller stacked over the energy harvesting provides an efficient power management. Performance have been assessed and compared with the analytical model for validation

Association of beta-adrenergic receptor polymorphisms and progression to heart failure in patients with idiopathic dilated cardiomyopathy

PURPOSE: Increased sympathetic nervous system activation via the beta-adrenergic pathway influences the evolution of idiopathic dilated cardiomyopathy. We assessed the effects of beta-adrenergic receptor variants on heart failure in idiopathic dilated cardiomyopathy. METHODS: We prospectively analyzed 171 consecutive patients (mean [+/- SD] age, 49 +/- 14 years; 129 men) with idiopathic dilated cardiomyopathy who were receiving conventional treatment. All were characterized by polymerase chain reaction-restriction fragment length polymorphism analysis for Ser49Gly and Arg389Gly in the beta1-adrenergic receptor; the 5' leader cistron (LC) Arg19Cys, Arg16Gly, Gln27Glu, and Thr164Ile in the beta2-adrenergic receptor; and Arg64Trp in the beta3-adrenergic receptor. The endpoint was heart failure, defined as a worsening of clinical condition leading to hospitalization for heart failure, cardiac transplantation, or death from heart failure. RESULTS: During a median follow-up of 33 months, 24 patients had heart failure. In a Cox univariate analysis, the beta1Gly49 and beta2 5'LC-Cys19, Arg16, and Gln27 alleles were associated with a lower risk of heart failure. In a multivariate analysis that considered age, functional class, left ventricular ejection fraction, and beta-blocker use, three beta2-adrenergic receptor alleles were associated with lower risk: 5'LC-Cys19 (hazard ratio [HR]: 0.15; 95% confidence interval [CI]: 0.05 to 0.42), Arg16 (HR: 0.12; 95% CI: 0.04 to 0.35), and Gln27 (HR: 0.15; 95% CI: 0.05 to 0.42). CONCLUSION: The Gly49 allele in the beta1-adrenergic receptor and the 5' LC-Cys19, Arg16, and Gln27 alleles in the beta2-adrenergic receptor were associated with a lower risk of heart failure in idiopathic dilated cardiomyopathy, suggesting that the beta1- and beta2-adrenergic receptor genes are modifier genes

Association of beta-adrenergic receptor polymorphisms and progression to heart failure in patients with idiopathic dilated cardiomyopathy

PURPOSE: Increased sympathetic nervous system activation via the beta-adrenergic pathway influences the evolution of idiopathic dilated cardiomyopathy. We assessed the effects of beta-adrenergic receptor variants on heart failure in idiopathic dilated cardiomyopathy. METHODS: We prospectively analyzed 171 consecutive patients (mean [+/- SD] age, 49 +/- 14 years; 129 men) with idiopathic dilated cardiomyopathy who were receiving conventional treatment. All were characterized by polymerase chain reaction-restriction fragment length polymorphism analysis for Ser49Gly and Arg389Gly in the beta1-adrenergic receptor; the 5' leader cistron (LC) Arg19Cys, Arg16Gly, Gln27Glu, and Thr164Ile in the beta2-adrenergic receptor; and Arg64Trp in the beta3-adrenergic receptor. The endpoint was heart failure, defined as a worsening of clinical condition leading to hospitalization for heart failure, cardiac transplantation, or death from heart failure. RESULTS: During a median follow-up of 33 months, 24 patients had heart failure. In a Cox univariate analysis, the beta1Gly49 and beta2 5'LC-Cys19, Arg16, and Gln27 alleles were associated with a lower risk of heart failure. In a multivariate analysis that considered age, functional class, left ventricular ejection fraction, and beta-blocker use, three beta2-adrenergic receptor alleles were associated with lower risk: 5'LC-Cys19 (hazard ratio [HR]: 0.15; 95% confidence interval [CI]: 0.05 to 0.42), Arg16 (HR: 0.12; 95% CI: 0.04 to 0.35), and Gln27 (HR: 0.15; 95% CI: 0.05 to 0.42). CONCLUSION: The Gly49 allele in the beta1-adrenergic receptor and the 5' LC-Cys19, Arg16, and Gln27 alleles in the beta2-adrenergic receptor were associated with a lower risk of heart failure in idiopathic dilated cardiomyopathy, suggesting that the beta1- and beta2-adrenergic receptor genes are modifier genes

Sensory stimulation for human guidance in robot walkers: A comparison between haptic and acoustic solutions

We compare two different solutions to guide an older adult along a safe path using a robotic walking assistant (the c-Walker). The two solutions are based on tactile or acoustic stimuli, respectively, and suggest a direction of motion that the user is supposed to take on her own will. We describe the technological basis for the hardware components, and show specialised path following algorithms for each of the two solutions. The paper reports an extensive user validation activity, with a quantitative and qualitative analysis