Pediatric bilateral vocal cord granulomas presenting as airway foreign body following prolonged intubation due to COVID-19 related multisystem inflammatory syndrome.

Background: This report is a case of bilateral vocal cord granulomas (VCG) in a 9-year-old child presenting as an airway foreign body and stridor following prolonged intubation due to COVID-19 pneumonia complicated by multisystem inflammatory syndrome in children (MIS-C).

Case Presentation: This case reports a 9-year-old male who presented to the emergency department with acute stridor concerning for airway obstruction. X-ray findings suggested an airway foreign body; however, on rigid bronchoscopy, ball-valving bilateral VCG obstructing 90% of the glottic airway were identified.

Evaluation of dynamical models: dissipative synchronization and other techniques.

Some recent developments for the validation of nonlinear models built from data are reviewed. Besides giving an overall view of the field, a procedure is proposed and investigated based on the concept of dissipative synchronization between the data and the model, which is very useful in validating models that should reproduce dominant dynamical features, like bifurcations, of the original system. In order to assess the discriminating power of the procedure, four well-known benchmarks have been used: namely, Duffing-Ueda, Duffing-Holmes, and van der Pol oscillators, plus the Hénon map.

Using data-driven discrete-time models and the unscented Kalman filter to estimate unobserved variables of nonlinear systems.

This paper addresses the problem of state estimation for nonlinear systems by means of the unscented Kalman filter (UKF). Compared to the traditional extended Kalman filter, the UKF does not require the local linearization of the system equations used in the propagation stage. Important results using the UKF have been reported recently but in every case the system equations used by the filter were considered known.