Analysis of the performances of various controllers adopted in the biomedical field for blood glucose regulation: a case study of the type-1 diabetes.

Diabetes remains a critical global health concern that necessitates urgent attention. The contemporary clinical approach to closed-loop care, specifically tailored for insulin-dependent patients, aims to precisely monitor blood glucose levels while mitigating the risks of hyperglycaemia and hypoglycaemia due to erroneous insulin dosing. This study seeks to address this life-threatening issue by assessing and comparing the performance of different controllers to achieve quicker settling and convergence rates with reduced steady-state errors, particularly in scenarios involving meal interruptions. The methodology involves the detection of plasma blood glucose levels, delivery of precise insulin doses to the actuator through a control architecture, and subsequent administration of the calculated insulin dosage to patients based on the control signal. Glucose-insulin dynamics were modelled using kinetics and mass balance equations from the Bergman minimal model. The simulation results revealed that the PID controller exhibited superior performance, maintaining blood glucose concentration around the preferred threshold ∼98.8% of the time, with a standard deviation of 2.50. This was followed by RST with a success rate of 98.5% and standard deviation of 5.00, SPC with a success rate of 58% and standard deviation of 2.99, SFC with a success rate of 55% and standard deviation of 10.08, and finally LCFB with a rate of 10% and significantly higher standard deviation of 64.55.

Airborne ultrasound transmission through circular damages in polymer plates.

Polymer tanks made of Polypropylene (PP) sub-assemblies are commonly used for their ease of formability, surface and optical quality. The tightness of an assembly is classically assessed by pressurizing the vessel and measuring a pressure drop after a given period. In order to avoid this long and imprecise method, active ultrasound methods can be envisioned, but should be carefully designed in order to derive the proper transducer configurations, frequencies and assess the performances of the method in terms of repeatability and detectability. In this article, a thermoviscous Finite Element Model (FEM) is derived in order to predict the effect of realistic damages on the measured transmitted acoustic field in bonded polymer joints. Three damage scenarios are considered, namely through holes, flat-bottom holes and internal voids that may impair the tightness and durability of a polymer assembly. Numerical results in terms of on-axis sound pressure spectra and directivity diagrams are presented and verified experimentally on a flat panel. These results allow the derivation of design rules for the active inspection of polymer jointed structures.

Purely mechanically driven door-controlled disinfection device for automatic COVID-19.

The COVID-19 outbreak is a sharp reminder that pandemics, like other rarely occurring catastrophes, have happened in the past and will continue to happen in the future. It is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is an emerging disease. There has been a rapid increase in cases and deaths since it was identified in Wuhan, China. Even if we cannot prevent dangerous viruses from emerging, we should prepare to dampen their effects on society. The current outbreak has had severe economic consequences across the globe, and it does not look like any country will be unaffected. This not only has consequences for the economy; all of society is affected, which has led to dramatic changes in how businesses act and consumers behave. It is in this context that this paper describes a device based on a mechanical spray disinfection system that does not use an electrical source or detection sensor, thus facilitating the use of this system by anyone. The disinfection process is launched automatically by the movement of a door, which changes the position of a piston, triggering the spraying of a disinfectant liquid. This door-controlled automatic decontamination system could be an effective tool in the fight against the current COVID-19 pandemic and, in general, could help to address the health challenges related to hygiene and disease prevention at low cost.