Hierarchical programming language for modal multi-rate real-time stream processing applications

Modal multi-rate stream processing applications with real-time constraints which are executed on multi-core embedded systems often cannot be conveniently specified using current programming languages. An important issue is that sequential programming languages do not allow for convenient programming of multi-rate behavior, whereas parallel programming languages are insufficiently analyzable such that deadlock-freedom and a sufficient throughput cannot be guaranteed.\ud \ud In this paper a programming language is proposed by which a sequential specification of the behavior of an application can be nested in a concurrent specification. Multi-rate behavior can be conveniently expressed using concurrent modules which have well-defined, but restricted interfaces. Complex control behavior can be expressed in the sequential specification of the body of a module. The language is not Turing complete such that a Compositional Temporal Analysis (CTA) model can be derived. It is shown that the CTA model can be used despite the presence of control statements and that the composition of black-box components is possible. Algorithms with a polynomial time complexity can be used to verify whether throughput and latency constraints are met and to determine sufficient buffer capacities.\ud \ud A Phase Alternating Line (PAL) video decoder application is used to demonstrate the applicability of the presented language and analysis approach

Diagnostic performance of stress myocardial perfusion imaging for coronary artery disease: A systematic review and meta-analysis

Objectives To determine and compare the diagnostic performance of stress myocardial perfusion imaging (MPI) for the diagnosis of obstructive coronary artery disease (CAD), using conventional coronary angiography (CCA) as the reference standard. Methods We searched Medline and Embase for literature that evaluated stress MPI for the diagnosis of obstructive CAD using magnetic resonance imaging (MRI), contrastenhanced echocardiography (ECHO), single-photon emission computed tomography (SPECT) and positron emission tomography (PET). Results All pooled analyses were based on random effects models. Articles on MRI yielded a total of 2,970 patients from 28 studies, articles on ECHO yielded a sample size of 795 from 10 studies, articles on SPECT yielded 1,323 from 13 studies. For CAD defined as either at least 50 %, at least 70 % or at least 75 % lumen diameter reduction on CCA, the natural logarithms of the diagnostic odds ratio (lnDOR) for MRI (3.63; 95 % CI 3.26-4.00) was significantly higher compared to that of SPECT (2.76; 95 % CI 2.28-3.25; P=0.006) and that of ECHO (2.83; 95 % CI 2.29-3.37; P=0.02). There was no significant difference between the lnDOR of SPECT and ECHO (P=0.52). Conclusion Our results suggest that MRI is superior for the diagnosis of obstructive CAD compared with ECHO and SPECT. ECHO and SPECT demonstrated similar diagnostic performance. Key Points ̇ MRI can assess myocardial perfusion. ̇ MR perfusion diagnoses coronary artery disease better than echocardiography or SPECT. ̇ Echocardiography and SPECT have similar diagnostic performance. ̇ MRI can save coronary artery disease patients from more invasive tests. ̇ MRI and SPECT show evidence of publication bias, implying possible overestimation

Dataflow Analysis for Multiprocessor Systems with Non-Starvation-Free Schedulers

Dataflow analysis techniques are suitable for the temporal analysis of real-time stream processing applications. However, the applicability of these models is currently limited to systems with starvation-free schedulers, such as Time-Division Multiplexing (TDM) schedulers. Removal of this limitation would broaden the application domain of dataflow analysis techniques significantly. In this paper we present a temporal analysis technique for Homogeneous Synchronous Dataflow (HSDF) graphs, that is also applicable for systems with non-starvation-free schedulers. Unlike existing dataflow analysis techniques, the proposed analysis technique makes use of an enabling-jitter characterization and iterative fixed-point computation. The presented approach is applicable for arbitrary (cyclic) graph topologies. Buffer capacity constraints are taken into account during the analysis and sufficient buffer capacities can be determined afterwards. The approach presented in this paper is the first approach that considers non-starvation-free schedulers in combination with arbitrary HSDF graphs. The proposed dataflow analysis technique is implemented in a tool. This tool is used to evaluate the analysis technique using examples that illustrate some important differences with other temporal analysis methods. The case-study discusses how the method presented in this paper can be used to solve a problem with the inaccuracy of the temporal analysis results of a real-time stream processing system. This stream processing system consists of an FM receiver together with a DAB receiver application which both share a Digital Signal Processor (DSP)

In vivo assessment of three dimensional coronary anatomy using electron beam computed tomography after intravenous contrast administration

Intravenous coronary angiography with electron beam computed tomography (EBCT) allows for the non-invasive visualisation of coronary arteries. With dedicated computer hardware and software, three dimensional renderings of the coronary arteries can be constructed, starting from the individual transaxial tomograms. This article describes image acquisition, postprocessing techniques, and the results of clinical studies. EBCT coronary angiography is a promising coronary artery imaging technique. Currently it is a reasonably robust technique for the visualisation and assessment of the left main and left anterior descending coronary artery. The right and circumflex coronary arteries can be visualised less consistently. Improvements in image acquisition and postprocessing techniques are expected to improve visualisation and diagnostic accuracy of the technique

Extending the voltage window in the characterization of electrical transport of large-area molecular junctions

A large bias window is required to discriminate between different transport models in large-area molecular junctions. Under continuous DC bias, the junctions irreversibly break down at fields over 9 MV/cm. We show that, by using pulse measurements, we can reach electrical fields of 35 MV/cm before degradation. The breakdown voltage is shown to depend logarithmically on both duty cycle and pulse width. A tentative interpretation is presented based on electrolysis in the polymeric top electrode. Expanding the bias window using pulse measurements unambiguously shows that the electrical transport exhibits not an exponential but a power-law dependence on bias. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3608154

Heart disease in the Netherlands: A quantitative update

In this review we discuss cardiovascular mortality, incidence and prevalence of heart disease, and cardiac interventions and surgery in the Netherlands. We combined most recently available data from various Dutch cardiovascular registries, Dutch Hospital Data (LMR), Statistics Netherlands (CBS), and population-based cohort studies, to provide a broad quantitative update. The absolute number of people dying from cardiovascular diseases is declining and cardiovascular conditions are no longer the leading cause of death in the Netherlands. However, a substantial burden of morbidity persists with 400,000 hospitalisations for cardiovascular disease involving over 80,000 cardiac interventions annually. In the Netherlands alone, an estimated 730,000 persons are currently diagnosed with coronary heart disease, 120,000 with heart failure, and 260,000 with atrial fibrillation. These numbers emphasise the continuous need for dedicated research on prevention, diagnosis, and treatment of heart disease in our country

Predictors of subjective health status 10 years post-PCI

Background: Subjective health status is an increasingly important parameter to assess the effect of percutaneous coronary intervention (PCI) in clinical practice.Aim of this study was to determine medical and psychosocial predictors of poor subjective health status over a 10 years' post-PCI period. Methods: We included a series of consecutive PCI patients (n = 573) as part of the RESEARCH registry, a Dutch single-center retrospective cohort study. Results: These patients completed the 36-item Short-Form Health Survey (SF-36) at baseline and 10 years post-PCI. We found 6 predictors of poor subjective health status 10 years post-PCI: SF-36 at baseline, age, previous PCI, obesity, acute myocardial infarction as indication for PCI, and diabetes mellitus (arranged from most to least numbers of sub domains). Conclusions: SF-36 scores at baseline, age, and previous PCI were significant predictors of subjective health status 10 years post-PCI. Specifically, the SF-36 score at baseline was an important predictor. Thus assessment of subjective health status at baseline is useful as an indicator to predict long-term subjective health status. Subjective health status becomes better by optimal medical treatment, cardiac rehabilitation and psychosocial support. This is the first study determining predictors of subjective health status 10 years post-PCI

The influence of optimal medical treatment on the 'obesity paradox', body mass index and long-term mortality in patients treated with percutaneous coronary intervention: A prospective cohort study

Objective: To assess whether the obesity paradox persists in the long term and to study the effect of optimal medical treatment on this phenomenon. Design: A retrospective cohort study. Setting: A tertiary care centre in Rotterdam. Participants: From January 2000 to December 2005, 6332 patients undergoing percutaneous coronary intervention for coronary artery disease were categorised into underweight (body mass index (BMI)30). Primary outcome measure: Mortality. Secondary outcome measures: Cardiac death and non-fatal myocardial infarction. Results: Optimal medical treatment was more common in obese patients as compared with normal weight patients (85% vs 76%; p<0.001). At a mean of 6.1 years, overweight and obese patients had a lower risk of all-cause mortality (HR: 0.75, 95% CI 0.66 to 0.86 and HR: 0.72, 95% CI 0.60 to 0.87, respectively). After adjusting for OMT in the multivariate analysis, BMI did not remain an independent predictor of longterm mortality (HR: 0.90, 95% CI 0.72 to 1.12 and HR: 1.07, 95% CI: 0.80 to 1.43, respectively). Conclusion: BMI is inversely related to long-term mortality in patients treated with percutaneous coronary intervention. Patients with a normal BMI are on suboptimal medical treatment when compared with those with a high BMI. A more optimal medical treatment in the obese group may explain the observed improved outcome in these patients