96 research outputs found

    Non-invasive Brain actuated control of a mobile robot by Human EEG

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    Brain activity recorded non-invasively is sufficient to control a moblie robot if advanced robotics is used in combination with asynchronous EEG analysis and machine learning techniques. Until now brain-actuated control has mainly relied on implanted electrodes, since EEG based systems have bben considered tto slow for controlling rapid and complex sequences of movements. We show that two human subjects successfully moved a robot between several rooms by mental control only using an EEG based brain-machine interface that recognized three mental states. Mental control was comparable to manual control on the same task with a preformance ration of 0.74

    Non-Invasive Brain-Actuated Control of a Mobile Robot

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    Recent experiments have shown the near possibility to use the brain electrical activity to directly control the movement of robotics or prosthetic devices. In this paper we report results with a portable non-invasive brain-computer interface that makes possible the continuous control of a mobile robot in a house-like environment. The interface uses 8 surface electrodes to measure electroencephalogram (EEG) signals from which a statistical classifier recognizes 3 different mental states. Until now, brain-actuated control of robots has relied on invasive approaches-requiring surgical implantation of electrodes-since EEG-based systems have been considered too slow for controlling rapid and complex sequences of movements. Here we show that, after a few days of training, two human subjects successfully moved a robot between several rooms by mental control only. Furthermore, mental control was only marginally worse than manual control on the same task

    Characterization of quantitative flow ratio and fractional flow reserve discordance using doppler flow and clinical follow-up

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    The physiological mechanisms of quantitative flow ratio and fractional flow reserve disagreement are not fully understood. We aimed to characterize the coronary flow and resistance profile of intermediate stenosed epicardial coronary arteries with concordant and discordant FFR and QFR. Post-hoc analysis of the DEFINE-FLOW study. Anatomical and Doppler-derived physiological parameters were compared for lesions with FFR+QFR− (n = 18) vs. FFR+QFR+ (n = 43) and for FFR−QFR+ (n = 34) vs. FFR−QFR− (n = 139). The association of QFR results with the two-year rate of target vessel failure was assessed in the proportion of vessels (n = 195) that did not undergo revascularization. Coronary flow reserve was higher [2.3 (IQR: 2.1–2.7) vs. 1.9 (IQR: 1.5–2.4)], hyperemic microvascular resistance lower [1.72 (IQR: 1.48–2.31) vs. 2.26 (IQR: 1.79–2.87)] and anatomical lesion severity less severe [% diameter stenosis 45.5 (IQR: 41.5–52.5) vs. 58.5 (IQR: 53.1–64.0)] for FFR+QFR− lesions compared with FFR+QFR+ lesions. In comparison of FFR−QFR+ vs. FFR-QFR- lesions, lesion severity was more severe [% diameter stenosis 55.2 (IQR: 51.7–61.3) vs. 43.4 (IQR: 35.0–50.6)] while coronary flow reserve [2.2 (IQR: 1.9–2.9) vs. 2.2 (IQR: 1.9–2.6)] and hyperemic microvascular resistance [2.34 (IQR: 1.85–2.81) vs. 2.57 (IQR: 2.01–3.22)] did not differ. The agreement and diagnostic performance of FFR using hyperemic stenosis resistance (> 0.80) as reference standard was higher compared with QFR and coronary flow reserve. Disagreement between FFR and QFR is partly explained by physiological and anatomical factors. Clinical Trials Registration https://www.clinicaltrials.gov; Unique identifier: NCT01813435. Graphical abstract: Changes in central physiological and anatomical parameters according to FFR and QFR match/mismatch quadrants

    Angiography-based superficial wall strain of de novo stenotic coronary arteries:serial assessment of vessels treated with bioresorbable scaffold or drug-eluting stent

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    Objectives: This study sought to present an angiography-based computational model for serial assessment of superficial wall strain (SWS, dimensionless) of de-novo coronary stenoses treated with either bioresorbable scaffold (BRS) or drug-eluting stent (DES). Background: A novel method for SWS allows the assessment of the mechanical status of arteries in-vivo, which may help for predicting cardiovascular outcomes. Methods: Patients with arterial stenosis treated with BRS (n = 21) or DES (n = 21) were included from ABSORB Cohort B1 and AIDA trials. The SWS analyses were performed along with quantitative coronary angiography (QCA) at pre-PCI, post-PCI, and 5-year follow-up. Measurements of QCA and SWS parameters were quantified at the treated segment and adjacent 5-mm proximal and distal edges. Results: Before PCI, the peak SWS on the ‘to be treated’ segment (0.79 ± 0.36) was significantly higher than at both virtual edges (0.44 ± 0.14 and 0.45 ± 0.21; both p &lt; 0.001). The peak SWS in the treated segment significantly decreased by 0.44 ± 0.13 (p &lt; 0.001). The surface area of high SWS decreased from 69.97mm2 to 40.08mm2 (p = 0.002). The peak SWS in BRS group decreased to a similar extent (p = 0.775) from 0.81 ± 0.36 to 0.41 ± 0.14 (p &lt; 0.001), compared with DES group from 0.77 ± 0.39 to 0.47 ± 0.13 (p = 0.001). Relocation of high SWS to device edges was often observed in both groups after PCI (35 of 82 cases, 41.7 %). At follow-up of BRS, the peak SWS remained unchanged compared to post-PCI (0.40 ± 0.12 versus 0.36 ± 0.09, p = 0.319). Conclusion: Angiography-based SWS provided valuable information about the mechanical status of coronary arteries. Device implantation led to a significant decrease of SWS to a similar extent with either polymer-based scaffolds or permanent metallic stents.</p

    Non-culprit MACE-rate in LRP:The influence of optimal medical therapy using DAPT and statins

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    Background/Purpose: The Lipid Rich Plaque (LRP) study demonstrated the association between coronary plaque lipid content and outcomes. In this LRP substudy, we assessed the impact of optimal medical therapy (OMT) on the occurrence of non-culprit major adverse cardiac events (NC-MACE). Advanced intracoronary imaging modalities are able to identify patients with vulnerable coronary lesion morphology associated with future events. Methods/Materials: A total of 1270 patients who underwent cardiac catheterization for suspected coronary artery disease (CAD) with evaluable maxLCBI4mm in non-culprit vessels and known medical therapy after discharge were followed for 2 years. OMT was defined as the use of a statin and dual antiplatelet therapy (DAPT). Results: Among the 1270 patients included in this substudy, 1110 (87.7%) had PCI for an index event, and 1014 (80%) patients received OMT. Estimated cumulative incidence functions of NC-MACE did not differ significantly between patients treated with or without OMT (log-rank p-value = 0.876). In patients labeled high risk (maxLCBI4mm > 400), cumulative incidence function also did not differ between patients treated with vs without OMT (log-rank p-value = 0.19). Conclusions: In the current LRP analysis, we could not identify a beneficial effect of OMT in the reduction of NC-MACE rate, even in patients with high-risk plaques during 24-month follow-up

    Long-term clinical outcomes of everolimus-eluting bioresorbable scaffolds versus everolimus-eluting stents:final five-year results of the AIDA randomised clinical trial

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    Background: Absorb bioresorbable vascular scaffold (BVS)-related events have been reported between 1 and 3 years – the period of active scaffold bioresorption. Data on the performance of the Absorb BVS in daily clinical practice beyond this time point are scarce. Aims: This report aimed to provide the final five-year clinical follow-up of the Absorb BVS in comparison with the XIENCE everolimus-eluting stent (EES). In addition, we evaluated the effect of prolonged dual antiplatelet therapy (DAPT) administration on events in the scaffold group. Methods: AIDA was a multicentre, investigator-initiated, non-inferiority trial, in which 1,845 unselected patients with coronary artery disease were randomly assigned to either the Absorb BVS (n=924) or the XIENCE EES (n=921). Target vessel failure (TVF), a composite of cardiac death, target vessel myocardial infarction or target vessel revascularisation, was the primary endpoint. Scaffold thrombosis cases were matched with controls and tested for the effect of prolonged DAPT. Results: Up to five-year follow-up, there was no difference in TVF between the Absorb BVS (17.7%) and the XIENCE EES (16.1%) (hazard ratio [HR] 1.31, 95% confidence interval [CI]: 0.90-1.41; p=0.302). Definite or probable device thrombosis (DT) occurred in 43 patients (4.8%) in the scaffold group compared to 13 patients (1.5%) in the stent group (HR 3.32, 95% CI: 1.78-6.17; p<0.001). DT between 3 and 4 years occurred six times in the Absorb arm versus three times in the XIENCE arm. Between 4 and 5 years, the incidence was three versus two, respectively. Of those three DT in the scaffold group, two occurred in XIENCE EES-treated lesions. The odds ratio of scaffold thrombosis in patients on DAPT compared to off DAPT throughout five-year follow-up was 0.36 (95% CI: 0.15-0.86). Conclusions: The excess risk of the Absorb BVS on late adverse events, in particular device thrombosis, in routine PCI continues up to 4 years and seems to plateau afterwards

    Chromothripsis is a common mechanism driving genomic rearrangements in primary and metastatic colorectal cancer

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    ABSTRACT: BACKGROUND: Structural rearrangements form a major class of somatic variation in cancer genomes. Local chromosome shattering, termed chromothripsis, is a mechanism proposed to be the cause of clustered chromosomal rearrangements and was recently described to occur in a small percentage of tumors. The significance of these clusters for tumor development or metastatic spread is largely unclear. RESULTS: We used genome-wide long mate-pair sequencing and SNP array profiling to reveal that chromothripsis is a widespread phenomenon in primary colorectal cancer and metastases. We find large and small chromothripsis events in nearly every colorectal tumor sample and show that several breakpoints of chromothripsis clusters and isolated rearrangements affect cancer genes, including NOTCH2, EXO1 and MLL3. We complemented the structural variation studies by sequencing the coding regions of a cancer exome in all colorectal tumor samples and found somatic mutations in 24 genes, including APC, KRAS, SMAD4 and PIK3CA. A pairwise comparison of somatic variations in primary and metastatic samples indicated that many chromothripsis clusters, isolated rearrangements and point mutations are exclusively present in either the primary tumor or the metastasis and may affect cancer genes in a lesion-specific manner. CONCLUSIONS: We conclude that chromothripsis is a prevalent mechanism driving structural rearrangements in colorectal cancer and show that a complex interplay between point mutations, simple copy number changes and chromothripsis events drive colorectal tumor development and metastasis.

    Probabilistic (logic) programming concepts

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    A multitude of different probabilistic programming languages exists today, all extending a traditional programming language with primitives to support modeling of complex, structured probability distributions. Each of these languages employs its own probabilistic primitives, and comes with a particular syntax, semantics and inference procedure. This makes it hard to understand the underlying programming concepts and appreciate the differences between the different languages. To obtain a better understanding of probabilistic programming, we identify a number of core programming concepts underlying the primitives used by various probabilistic languages, discuss the execution mechanisms that they require and use these to position and survey state-of-the-art probabilistic languages and their implementation. While doing so, we focus on probabilistic extensions of logic programming languages such as Prolog, which have been considered for over 20 years

    Genomic DNA Pooling Strategy for Next-Generation Sequencing-Based Rare Variant Discovery in Abdominal Aortic Aneurysm Regions of Interest—Challenges and Limitations

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    The costs and efforts for sample preparation of hundreds of individuals, their genomic enrichment for regions of interest, and sufficient deep sequencing bring a significant burden to next-generation sequencing-based experiments. We investigated whether pooling of samples at the level of genomic DNA would be a more versatile strategy for lowering the costs and efforts for common disease-associated rare variant detection in candidate genes or associated loci in a substantial patient cohort. We performed a pilot experiment using five pools of 20 abdominal aortic aneurysm (AAA) patients that were enriched on separate microarrays for the reported 9p21.3 associated locus and 42 additional AAA candidate genes, and sequenced on the SOLiD platform. Here, we discuss challenges and limitations connected to this approach and show that the high number of novel variants detected per pool and allele frequency deviations to the usually highly false positive cut-off region for variant detection in non-pooled samples can be limiting factors for successful variant prioritization and confirmation. We conclude that barcode indexing of individual samples before pooling followed by a multiplexed enrichment strategy should be preferred for detection of rare genetic variants in larger sample sets rather than a genomic DNA pooling strategy
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