Apparatus for supplying oxygen to a vehicle user, and vehicle comprising such an apparatus
Apparatus for supplying oxygen to a vehicle user, comprising a source of pressurized respiratory gas containing oxygen-enriched air, a flow-regulating and/or pressure-regulating unit, and at least one mask provided for supplying gas to the respiratory tract of said user, the regulating unit comprising at least one inlet connected to the source and at least one outlet connected to the mask, the regulating unit being configured to regulate the flow and/or the pressure of the respiratory gas supplied to the mask according to the respiratory demand of the user, the apparatus comprising at least one sensor measuring the pressure and/or the flow of respiratory gas delivered by the regulating unit to the mask, and an electronic data storage and processing unit configured to receive the measurements from the at least one sensor and to calculate, from these measurements, the frequency of the gas flows supplied to the mask and corresponding to the respiratory frequency of the user, to compare this calculated frequency against a threshold frequency and, when this calculated frequency is greater than the threshold frequency, to generate an audible and/or visual and/or vibratory warning signal.
1 . An apparatus for supplying oxygen to a pilot of an aircraft, comprising:
a source of pressurized respiratory gas containing oxygen-enriched air;
at least one mask provided for supplying gas to a respiratory track of the aircraft pilot;
a flow-regulating and/or pressure-regulating unit comprising at least one inlet connected to the source and at least one outlet connected to the mask, the flow-regulating and/or pressure-regulating unit being configured to regulate a flow and/or a pressure of said respiratory gas delivered to said mask according to a respiratory demand of the aircraft pilot;
at least one sensor measuring the pressure and/or the flow of said respiratory gas delivered to said mask;
an electronic data storage and processing unit; and
a display, for displaying a warning signal, connected to the electronic data storage and processing unit, wherein the electronic data storage and processing unit is configured to:
receive pressure and/or flow measurements from the at least one sensor;
calculate, from said measurements, a frequency of flows of said respiratory gas delivered to said mask that corresponds to a respiratory frequency of the aircraft pilot;
compare said calculated frequency against a threshold frequency from which there is a risk of hypocapnia;
when said calculated frequency is greater than said threshold frequency, control said display to generate an audible and/or visual and/or vibratory warning signal; and
control said display to generate an acoustic emission of a periodic signal that has a frequency corresponding to a target frequency that is less than or equal to said threshold frequency.
2 . The apparatus of claim 1 , wherein said at least one sensor comprises a pressure sensor measuring the pressure of respiratory gas delivered to said mask and said electronic data storage and processing unit is configured to calculate said frequency of the respiratory gas flows supplied to said mask by detecting successive determined negative pressures in said flows of said respiratory gas supplied to said mask from pressure measurements of said pressure sensor and measuring a frequency of said determined negative pressures.
3 . The apparatus of claim 1 , wherein said at least one sensor comprises a flow sensor measuring said flow of respiratory gas delivered to said mask and said electronic data storage and processing unit is configured to calculate said frequency of said respiratory gas flows supplied to said mask by detecting successive determined variations in said flow of said respiratory gas flows supplied to said mask from said flow measurement of the flow sensor and calculate said frequency of the respiratory gas flows supplied to the mask by measuring said frequency of said determined flow variations.
4 . The apparatus of claim 1 , said electronic data storage and processing unit is configured to control said display when a difference between said calculated frequency and said threshold frequency is less than a determined value.
5 . The apparatus of claim 1 , wherein said electronic data storage and processing unit is configured to permit manual or automatic modification of said value of the threshold frequency.
6 . The apparatus of claim 5 , wherein said value of said threshold frequency is modified according to at least one of the following: i) an identity of the aircraft pilot, a physiology of the aircraft pilot, ii) a flight altitude of the aircraft, iii) a load factor experienced by the aircraft pilot and inherent to maneuvers of the aircraft, iv) a phase of movement of the aircraft including take-off, cruising and/or landing, v) a nature of the aircraft path, and vi) a speed of the aircraft.
7 . The apparatus of claim 5 , wherein said value of said threshold frequency is selected from among a plurality of predefined predetermined threshold frequencies.
8 . The apparatus of claim 1 , wherein said at least one sensor is located at a level of said flow-regulating and/or pressure-regulating unit and/or at a level of said mask.
9 . The apparatus of claim 1 , wherein said flow-regulating and pressure-regulating unit comprises a mechanical or electromechanical demand valve.
10 . An aircraft vehicle that includes the apparatus of claim 1 .
11 . The aircraft vehicle of claim 10 , wherein said electronic data storage and processing unit is configured to permit manual or automatic modification of said value of the threshold frequency.
12 . The aircraft vehicle of claim 10 , wherein said value of said threshold frequency is modified according to at least one of the following: i) an identity of the aircraft pilot, ii) a physiology of the aircraft pilot, iii) a flight altitude of the aircraft, iv) a load factor experienced by the aircraft pilot and inherent to maneuvers of the aircraft, v) a phase of movement of the aircraft including take-off, cruising and/or landing, and vi) a speed of the aircraft.