Patent ID: 8870784

Claim:
An apparatus for ventilatory anesthesia of a patient by administration of a gas containing gaseous xenon, said apparatus comprising: a main gas circuit (CP) in the form of an open or closed circuit having an inhalation branch ( 16 ) for supplying a gaseous mixture containing xenon to the patient and an exhalation branch ( 18 ) for conveying the gaseous mixture containing xenon exhaled by the patient, and means (S 6 , M 1 ) for determining the concentration of xenon, which are designed and able to determine the gaseous xenon content in at least part of the main circuit (CP), said means (S 6 , M 1 ) for determining the concentration of xenon comprising a first hot-wire sensor (S 6 -E) having a first electrically conductive wire (FC 1 ) in direct contact with at least part of the gaseous flow containing the xenon, wherein: the first hot-wire sensor (S 6 -E) having the first conductive wire (FC 1 ) further comprises a gas-supply main line (LP) having a first bypass line (BP) connected fluidically to said gas-supply main line (LP) upstream and downstream from said first conductive wire (FC 1 ), as seen in the direction of circulation of the gas in the main line (LP), and at least a first solenoid valve (EV 1 ) is arranged in the area of the upstream connection of the first bypass line (BP) to said main line (LP) in such a way as to direct the gaseous flow containing the xenon either to the main line (LP), on which said first conductive wire (FC 1 ) is arranged, or to the first bypass line (BP).