IntroductionThe driving pressure (ΔP) has an independent association with outcome in patients with acute respiratory distress syndrome (ARDS). INTELLiVENT-Adaptive Support Ventilation (ASV) is a closed-loop mode of ventilation that targets the lowest work and force of breathing.AimTo compare transpulmonary and respiratory system ΔP between closed-loop ventilation and conventional pressure controlled ventilation in patients with moderate-to-severe ARDS.MethodsSingle-center randomized cross-over clinical trial in patients in the early phase of ARDS. Patients were randomly assigned to start with a 4-h period of closed-loop ventilation or conventional ventilation, after which the alternate ventilation mode was selected. The primary outcome was the transpulmonary ΔP; secondary outcomes included respiratory system ΔP, and other key parameters of ventilation.ResultsThirteen patients were included, and all had fully analyzable data sets. Compared to conventional ventilation, with closed-loop ventilation the median transpulmonary ΔP with was lower (7.0 [5.0–10.0] vs. 10.0 [8.0–11.0] cmH2O, mean difference − 2.5 [95% CI − 2.6 to − 2.1] cmH2O; P = 0.0001). Inspiratory transpulmonary pressure and the respiratory rate were also lower. Tidal volume, however, was higher with closed-loop ventilation, but stayed below generally accepted safety cutoffs in the majority of patients.ConclusionsIn this small physiological study, when compared to conventional pressure controlled ventilation INTELLiVENT-ASV reduced the transpulmonary ΔP in patients in the early phase of moderate-to-severe ARDS. This closed-loop ventilation mode also led to a lower inspiratory transpulmonary pressure and a lower respiratory rate, thereby reducing the intensity of ventilation.Trial registration Clinicaltrials.gov, NCT03211494, July 7, 2017. https://clinicaltrials.gov/ct2/show/NCT03211494?term=airdrop&draw=2&rank=1.
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BackgroundOcclusions of intravenous (IV) tubing can prevent vital and time-critical medication or solutions from being delivered into the bloodstream of patients receiving IV therapy. At low flow rates (≤ 1 ml/h) the alarm delay (time to an alert to the user) can be up to 2 h using conventional pressure threshold algorithms. In order to reduce alarm delays we developed and evaluated the performance of two new real-time occlusion detection algorithms and one co-occlusion detector that determines the correlation in trends in pressure changes for multiple pumps.MethodsBench-tested experimental runs were recorded in triplicate at rates of 1, 2, 4, 8, 16, and 32 ml/h. Each run consisted of 10 min of non-occluded infusion followed by a period of occluded infusion of 10 min or until a conventional occlusion alarm at 400 mmHg occurred. The first algorithm based on binary logistic regression attempts to detect occlusions based on the pump’s administration rate Q(t) and pressure sensor readings P(t). The second algorithm continuously monitored whether the actual variation in the pressure exceeded a threshold of 2 standard deviations (SD) above the baseline pressure. When a pump detected an occlusion using the SD algorithm, a third algorithm correlated the pressures of multiple pumps to detect the presence of a shared occlusion. The algorithms were evaluated using 6 bench-tested baseline single-pump occlusion scenarios, 9 single-pump validation scenarios and 7 multi-pump co-occlusion scenarios (i.e. with flow rates of 1 + 1, 1 + 2, 1 + 4, 1 + 8, 1 + 16, and 1 + 32 ml/h respectively). Alarm delay was the primary performance measure.ResultsIn the baseline single-pump occlusion scenarios, the overall mean ± SD alarm delay of the regression and SD algorithms were 1.8 ± 0.8 min and 0.4 ± 0.2 min, respectively. Compared to the delay of the conventional alarm this corresponds to a mean time reduction of 76% (P = 0.003) and 95% (P = 0.001), respectively. In the validation scenarios the overall mean ± SD alarm delay of the regression and SD algorithms were respectively 1.8 ± 1.6 min and 0.3 ± 0.2 min, corresponding to a mean time reduction of 77% and 95%. In the multi-pump scenarios a correlation > 0.8 between multiple pump pressures after initial occlusion detection by the SD algorithm had a mean ± SD alarm delay of 0.4 ± 0.2 min. In 2 out of the 9 validation scenarios an occlusion was not detected by the regression algorithm before a conventional occlusion alarm occurred. Otherwise no occlusions were missed.ConclusionsIn single pumps, both the regression and SD algorithm considerably reduced alarm delay compared to conventional pressure limit-based detection. The SD algorithm appeared to be more robust than the regression algorithm. For multiple pumps the correlation algorithm reliably detected co-occlusions. The latter may be used to localize the segment of tubing in which the occlusion occurs.
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Background: The emphasis on impact factors and the quantity of publications intensifies competition between researchers. This competition was traditionally considered an incentive to produce high-quality work, but there are unwanted side-effects of this competition like publication pressure. To measure the effect of publication pressure on researchers, the Publication Pressure Questionnaire (PPQ) was developed. Upon using the PPQ, some issues came to light that motivated a revision.Method: We constructed two new subscales based on work stress models using the facet method. We administered the revised PPQ (PPQr) to a convenience sample together with the Maslach Burnout Inventory (MBI) and the Work Design Questionnaire (WDQ). To assess which items best measured publication pressure, we carried out a principal component analysis (PCA). Reliability was sufficient when Cronbach's alpha > 0.7. Finally, we administered the PPQr in a larger, independent sample of researchers to check the reliability of the revised version.Results: Three components were identified as 'stress', 'attitude', and 'resources'. We selected 3 × 6 = 18 items with high loadings in the three-component solution. Based on the convenience sample, Cronbach's alphas were 0.83 for stress, 0.80 for attitude, and 0.76 for resources. We checked the validity of the PPQr by inspecting the correlations with the MBI and the WDQ. Stress correlated 0.62 with MBI's emotional exhaustion. Resources correlated 0.50 with relevant WDQ subscales. To assess the internal structure of the PPQr in the independent reliability sample, we conducted the principal component analysis. The three-component solution explains 50% of the variance. Cronbach's alphas were 0.80, 0.78, and 0.75 for stress, attitude, and resources, respectively.Conclusion: We conclude that the PPQr is a valid and reliable instrument to measure publication pressure in academic researchers from all disciplinary fields. The PPQr strongly relates to burnout and could also be beneficial for policy makers and research institutions to assess the degree of publication pressure in their institute.
MSEs have encountered limitations while pushing the limits of catheter tip sensors performance. The limitations summarized: - sensors are not immune to electrical signal noise, cross talk, and EM fields; - sensors are not immune to high magnetic fields, i.e. not suitable for MR imaging; - extending the amount of sensors on the catheter tip is limited due to cluttering of wires. A fundamentally different approach using integrated optics is chosen for developing a new generation catheter sensors. The complexity of the design and production problems represents a knowledge gap, that can be bridged in the proposed consortium. This project consists of four work packages, total duration two years, subdivided into four phases. A crucial deliverable of the project is presented at the end of phase IV (WP4), namely a demonstrator integrating pressure and temperature sensors (obtained from WP1) with a newly designed readout system. This system is modularly extendable for future catheter tip sensors. In WP1, pressure- and temperature sensors are developed using two design approaches. In WP2 the influence of downscaling an ultrasound MZI device is explored and the microfabrication process parameters are studied. An additional goal of WP2 is to find the most suitable method for measuring lactate concentration. Among the deliverables five manuscripts: manuscript 1 includes simulations and measurements of the developed pressure and temperature sensors, manuscript 2 answers the question: can a grated fiber be used for measuring pressure and temperature on a tip? Manuscript 3 answers the question: which method is most suitable for measuring lactate concentration on a tip? Manuscript 4 answers the question: does a US intensity detector fit on a catheter tip while obeying the LoR? Manuscript 5 describes the performance of the demonstrator (Phase IV), i.e. integration of T/P sensing with a modular read out system.
This project is part of an interdisciplinary and international collaboration bringing together experts in nanomaterials, sensor technology, and engineering from the University of Technology of Troyes (UTT, France), Eindhoven University of Technology (TU/e, The Netherlands) and Hanze University of Applied Sciences (HUAS, The Netherlands). It presents an innovative, integrated approach including design, fabrication, characterization, and integration of flexible sensors dedicated to wind turbine blade monitoring, aiming to advance smart monitoring and renewable energy research. The sensor will be developed using functional polymer films decorated with conductive nanoparticles. A novel manufacturing approach will be applied, combining additive manufacturing techniques with the colloidal deposition of silver or gold nanoparticles.
