Abstract: A device for detecting the improper adjustment of a ventilatory support machine used on a mammal. The device (12) includes measuring elements (40) for taking a measurement, as a function of time, of a neurophysiological signal involved in the respiratory process of the mammal for at least two successive breathing cycles, each breathing cycle comprising a respiratory initiation time; an input for receiving a respiratory initiation signal (to) which is different from the neurophysiological signal; elements (42) for processing the neurophysiological signals, which are configured to process the neurophysiological signals for each respiratory initiation time over a period of time starting from the respiratory initiation time; and elements (44) for detecting an improper adjustment of the ventilator using the processed signals.