On stationary points of nonexpansive set-valued mappings

In this paper we deal with stationary points (also known as endpoints) of nonexpansive set-valued mappings and show that the existence of such points under certain conditions follows as a consequence of the existence of approximate stationary sequences. In particular we provide abstract extensions of well-known fixed point theorems.Dirección General de Enseñanza SuperiorJunta de Andalucí

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

The original version of this article unfortunately contained a mistake

Power Electronic Converter for Efficient Home Energy Management

The residential and commercial buildings are going green to reduce the carbon footprint. To improve the energy efficiency of the buildings, the Internet of Things can be used in conjunction with power electronic converters to improve the performance of energy efficient buildings. The distributed generation for the buildings mainly consists of battery energy storage, wind generator, solar PV panels along with the national utility grid. So, the power/energy from renewable sources can be efficiently managed by the power electronics converter. Mainly the power electronic converters are two categories one for the energy utilization side and the second is the generation, transmission, and distribution of the electrical energy. The power electronic converter has been developed to address the multiple source's communications at the central converter which reduces the utility bill payment to the energy (grid) suppliers and depends fully on the renewable energy sources along with the battery energy storage. To achieve this a novel power electronic converter has been proposed. This directly connects the PV panels with the semiconductor devices, passive components like inductors and capacitors along with the battery energy storage. The resultant output is directly feeding o the utility grid and simultaneously commercial home. A detailed mathematical analysis has been carried out along with the novel switching algorithm has been proposed. The simulation is performed in the MATLAB Simulink to validate the operation/working of the proposed converter. an experimental prototype500Watt has been developed to test the mathematical validity and a suitable control algorithm has been developed for the proper operation

Electronic Ventilator for COVID19 Patient Treatment

In response to expected shortages of ventilators caused by COVID19 pandemic, globally many organizations and institutes have developed low cost and high rate production ventilators. Many of these ventilators are mechanical type and pneumatic type which are easy to produce but do not have all the necessary control parameters and their options as per the patient requirements. Furthermore they are the failure rate is very high as and computer interfacing and control is difficult. To address all the drawbacks of the available ventilator, power electronic motor drive based digitally controlled ventilator is designed, developed and tested in the Qatar university laboratory. It consists of semiconductor switches based inverter driven by the microcontroller to run the BLDC (Brushless Direct Current) motor. All the parameters such as pressure, rate of flow and volume required is successfully tuned and trained to the microcontroller. As per the patient requirement, it can deliver the required amount of the oxygen into the patient's body and similarly removes the exhaling air from inside. As all the control process is happening by the microcontroller all the safety, sound and valves can be easily integrated to reduce the risk for the patient. Minimal number of access control buttons are provided to use the developed ventilator so that it can be easily used by all kinds of hospital nurse

A Pencil Shaped Switched Capacitor Multilevel Inverter with Voltage Boosting Ability

This manuscript proposes a unique topology of switched capacitor based multilevel inverter (MLI) that employs capacitors and DC sources as DC connections to generate staircase voltage waveforms. The use of DC sources is reduced in this MLI. Even with lower DC sources, the MLI is capable of generating 9 voltage levels. The novel MLI module produces 9 levels with a pair of equal DC sources. Two chargeable capacitors and 12 semiconductor switches are also included in this module. The capacitors are self-charging and they do not need any additional circuit. Because of the low number of components, it is suitable for a wide variety of applications. The module is developed using the combination of a directional inverter, a T-type inverter, and a few additional switches. It can also be extended by utilizing a cascade modular configuration, resulting in a module that can produce higher voltage levels. In the absence of any external circuit like H-bridge circuit, this new module can still synthesize negative voltage steps. In order to obtain an output voltage which is almost sinusoidal, the nearest level control switching modulation (NLC) scheme is used. Simulations are conducted using MATLAB/Simulink, and a hardware model is developed to demonstrate the MLI's simulation and experimental performance