Jonathan Stanley Harold Denyer, Kurt Nikander: Inhalation apparatus and method. Astra Aktiebolag, Medic Aid, Fish & Richardson P C, February 27, 2001: US06192876 (98 worldwide citation)

An apparatus for and a method of ensuring the fit of a face mask to the face of a patient, the apparatus including a face mask having an inlet through which gas can be inhaled and a sensor for measuring the flow rate of gas drawn through the inlet of the face mask. The fit of the face mask is determ ...