Patent ID: 8910632

Claim:
A mechanical ventilator apparatus for supplying breathing gas to humans, the ventilator comprising: a ventilator arrangement; and a processing unit configured to obtain flow signals from sensors indicative of at least breathing gas flow; wherein said processing unit is arranged to analyze said flow signals with respect to kinetic energy content relating to a breathing effort of a patient by applying said flow signals to a derivative procedure in order to deduce said kinetic energy content via a calculation of ½ρV 2 , where ρ is a density of breathing gas and V is a speed of a breathing flow gas, and said derivative procedure further comparing an output from said derivative procedure to at least one predetermined trigger level, to trigger a response if said kinetic energy content reaches said trigger level, and to trigger at least one of an inspiratory phase or an expiratory phase of a breathing cycle using a supply of said breathing gas according to said reached trigger level.