- author = "Milos Ajcevic",
- title = "Personalized setup of high frequency percussive ventilator by estimation of respiratory system viscoelastic parameters",
- school = "Universita degli studi di Trieste",
- year = "2013/2014",
- year = "2013",
- address = "Italy",
- keywords = "genetic algorithms, genetic programming, High Frequency Percussive Ventilation, Respiratory signal processing, Parameter identification",
-
URL = "
http://hdl.handle.net/10077/10976",
-
URL = "
https://www.openstarts.units.it/bitstream/10077/10976/1/Ajcevic_PhD.pdf",
- size = "95 pages",
-
abstract = "High Frequency Percussive Ventilation (HFPV) is a
non-conventional ventilatory modality which has proven
highly effective in patients with severe gas exchange
impairment. However, at the present time, HFPV
ventilator provides only airway pressure measurement.
The airway pressure measurements and gas exchange
analysis are currently the only parameters that guide
the physician during the HFPV ventilator setup and
treatment monitoring. The evaluation of respiratory
system resistance and compliance parameters in patients
undergoing mechanical ventilation is used for lung
dysfunctions detection, ventilation setup and treatment
effect evaluation. Furthermore, the pressure measured
by ventilator represents the sum of the endotracheal
tube pressure drop and the tracheal pressure. From the
clinical point of view, it is very important to take
into account the real amount of pressure dissipated by
endotracheal tube to avoid lung injury. HFPV is
pressure controlled logic ventilation, thus
hypoventilation and hyperventilation cases are possible
because of tidal volume variations in function of
pulmonary and endotracheal tube impedance.
This thesis offers a new approach for HFPV ventilator setup in accordance with protective ventilatory strategy and optimization of alveolar recruitment using estimation of the respiratory mechanics parameters and endotracheal pressure drop. Respiratory system resistance and compliance parameters were estimated, firstly in vitro and successively in patients undergoing HFPV, applying least squares regression on Dorkin high frequency model starting from measured respiratory signals. The Blasius model was identified as the most adequate to estimate pressure drop across the endotracheal tube during HFPV. Beside measurement device was developed in order to measure respiratory parameters in patients undergoing HFPV.
The possibility to tailor HFPV ventilator setup, using respiratory signals measurement and estimation of respiratory system resistance, compliance and endotracheal tube pressure drop, provided by this thesis, opens a new prospective to this particular ventilatory strategy, improving its beneficial effects and minimizing ventilator-induced lung damage.",
-
notes = "In vitro estimation of tracheal pressure by Genetic
programming Supervisor: Agostino Accardo
10077_10976",
