Device for simulation of restrictive pathologies in healthy subjects with non-invasive mechanical ventilation

Abstract

The respiratory mechanics assessment in patients with mechanical ventilation allows to adjust the treatment in intensive care units related to the ventilatory mode and parameters of mechanical ventilator settings. However, to estimate the compliance and respiratory resistance in spontaneous ventilation is only possible with obstructive maneuvers or invasive techniques. One of the most important limitations to develop new techniques for respiratory mechanics estimation is the non-stationary characteristic of the system and the variability of parameters according to the variability of the breathing pattern. The aim of this article is to present and evaluate a device that allows artificially modify the thoracic compliance of a healthy subject, which will make possible to register in the future a useful database for the development of techniques for estimating ventilatory mechanics. The device was formed by a cuirass, a pump and a controller that allows to vary the pressure inside the cuirass, which was placed in the chest and abdomen of the volunteers to change compliance in a controlled manner. 5 volunteers participated in the performance test of the device, achieving percentage changes of 34.5 ± 9.4% respecting their resting value for a pressure of 10 cmH2O and changes of 46.8 ± 5.7% for the maximum pressure of 20 cmH2O. It was possible to design a device that allowed to artificially modify thoracic compliance in a comparable way for any healthy subject.

Keywords

• respiratory mechanics
• thoracic compliance
• restrictive diseases
• control systems