Pressure-controlled breathing aid

Abstract

The ventilation module ( 8 ) regulates the inspiratory pressure (P) according to an inspiratory pressure order (AI). A control module ( 9 ) compares the breathed volume at each cycle (VTI) with a minimum volume order (VRImini) and varies the pressure order (AI) in the direction tending to maintain the breathed volume (VTI) just over the minimum (VTImini), but keeping the pressure order (AI) within the interval comprised between the two extreme values (AImini, AImaxi). Utilization to combine the advantages of the pressure mode ventilation with those of the volumetric ventilation.

1 . A breathing aid device, comprising: 
 a patient connection;    an inspiratory branch in fluid communication with said patient connection, said inspiratory branch including an inspiration valve;    an expiratory branch in fluid communication with said patient connection and said inspiratory branch;    means for controlling expiration in fluid communication with said expiratory branch, said means for controlling expiration including an expiration valve;    means for detecting pressure operatively connected to said inspiratory branch;    means for ventilating in fluid communication with said inspiratory branch, said means for ventilating including means for supplying a breathable gas through said inspiratory branch at an adjustable pressure, said means for ventilating further including means for controlling the inspiration valve and the expiration valve, wherein the inspiration valve is closed during expiration and the expiration valve is closed during inspiration, said means for ventilating further including pressure control means for comparing a pressure command to a pressure signal provided by said means for detecting pressure and for adjusting the pressure of the means for supplying; and    means for regulating a patient's breathed volume, said means for regulating including means for controlling volume and means for measuring volume, wherein the means for controlling volume provides the pressure command to the pressure control means, and wherein the means for measuring volume provides a signal indicative of a measured volume of breathed gas to the means for controlling volume.