Apparatus for measuring oxygen consumption and the exchange of other breathing gases

Claim 1

An apparatus for measuring the consumption or exchange of a gas component in breathing gases inhaled or exhaled by a subject over a predetermined period of time, including means sensing the amount of said gas component in the inhaled and exhaled gases and determining the volume of the exhaled gas during said time period, said means providing electrical signals proportionate to said amounts and volume, which are supplied to a data processing unit computing the consumption value, said apparatus comprising: a variable volume vessel for collecting the exhaled gas, a main pneumatic circuit connecting said subject to said vessel, a pair of valve means arranged along said circuit and defining a compartment in which said sensing means is arranged, a first exhaust opening arranged in said compartment and connecting the latter with the ambient, a second exhaust opening arranged along said circuit between said subject and said compartment and connecting said subject to the ambient, said pair of valve means being movable between a first position in which they close said compartment and a second position in which they close said exhaust openings, an auxiliary circuit for supplying into said compartment the same gas inhaled by the subject, means for controlling said pair of valve means and said auxiliary circuit so that, in said first position, the supplied gas enters said compartment and flows out through said first opening, while the gas exhaled by the subject is deflected into the ambient through said second exhaust opening, whereas, in said second position the supplying of gas into said compartment is interrupted and the exhaled gas flows through said compartment into said vessel, means being further provided for emptying said vessel when the valve means are in said first position.

Claim 2

An apparatus for measuring the consumption or exchange of a gas component in breathing gases inhaled or exhaled by a subject over a predetermined period of time, including means sensing the amount of said gas component in the inhaled and exhaled gases and determining the volume of the exhaled gas during said time period, said means providing electrical signals proportionate to said amounts and volume, which are supplied to a data processing unit computing the consumption value, said apparatus comprising: a variable volume vessel for collecting the exhaled gas, a main pneumatic circuit connecting said subject to said vessel, a pair of valve means arranged along said circuit and defining a compartment in which said sensing means is arranged, a first exhaust opening arranged in said compartment and connecting the latter with the ambient, a second exhaust opening arranged along said circuit between said subject and said compartment and connecting said subject to the ambient, said pair of valve means being movable between a first position in which they close said compartment and a second position in which they close said exhaust openings, an auxiliary circuit for supplying into said compartment the same gas inhaled by the subject, means for controlling said pair of valve means and said auxiliary circuit so that, in said first position, the supplied gas enters said compartment and flows out through said first opening, while the gas exhaled by the subject is deflected into the ambient through said second exhaust opening, whereas, in said second position the supplying of gas into said compartment is interrupted and the exhaled gas flows through said compartment into said vessel, means being further provided for emptying said vessel when the valve means are in said first position.