  In this paper we present a method for the estimation of leaks in non-invasive
ventilation. Accurate estimation of leaks is a key component of a ventilator,
since it determines the ventilator performance in terms of patient-ventilator
synchrony and air volume delivery. In particular, in non-invasive ventilation,
the patient flow is significantly different from the flow measured at the
ventilator outlet. This is mostly due to the vent orifice along the tube that
is used for exhalation, but also to the non-intentional leaks that occur
elsewhere in the circuit (e.g., at the mask). Such leaks are traditionally
quantified via a model with two parameters, but only one of them is continually
updated - the other is fixed. The new algorithm allows for breath-by-breath
update of both parameters. This was made possible by leveraging a model
describing the patient respiratory mechanics.
