The present invention relates to a process for operating or for controlling an artificial ventilation apparatus making it possible to diagnose or to treat sleep disorders of ORE type, during which a patient is subject to restrictions of his respiratory volume which are smaller than those occurring during a period of apnea or of hypopnea, but nevertheless of sufficient concern to require treatment, as well as to such an apparatus.
At present, numerous apparatuses for the artificial ventilation of a patient make it possible to ensure effective detection of certain respiratory sleep disorders, namely apneas or hypopneas.
An apnea is defined as a sleep disorder which is characterized in an individual by stoppage of respiratory activity for a variable period of time during his sleep, that is to say a reduction of more than 90% in the amplitude of the normal respiratory flow rate of this individual.
FIG. 1 depicts a respiratory cycle in a patient subject to sleep apnea type disorders. As may be seen, between times t1 and t2, the respiratory volume decreases considerably relative to the normal respiratory volume (100%), reaching a respiratory volume of the order of or close to 0%, that is to say periods during which the patient is not breathing, i.e. is in a period of apnea.
Additionally, a hypopnea is in turn defined as a sleep disorder which is characterized in an individual by a 50% decrease in the amplitude of the respiratory flow rate of this individual for a variable period of time during his sleep.
FIG. 2 depicts a respiratory cycle in a patient subject to sleep hypopnea type disorders. As may be seen, between times t1 and t2, the respiratory volume decreases sharply relative to the normal respiratory volume (100%), reaching a respiratory volume of the order of or less than 50% of the normal volume, that is to say periods during which the patient is not breathing fully, i.e. is in a period of hypopnea. However, during the periods of hypopnea, the respiratory volume decreases much less than in periods of apnea.
There are nowadays numerous methods and apparatuses making it possible to diagnose or to treat these two types of respiratory disorders and, in this regard, mention may be made in particular of the documents U.S. Pat. Nos. 5,245,995, 5,148,802, 5,199,424, 4,655,213, 5,335,654, 5,353,788, 5,458,137 and EP-A-505232.
However, recent studies have shown the existence of respiratory events of a third type giving rise to respiratory sleep disorders in an individual affected thereby, namely respiratory events which do not entail a reduction of from 50% to almost 100% of the respiratory flow rate, as in the case of hypopnea or apnea, but which give rise, on the other hand, to a reduction in respiratory volume for the duration of the event, followed by a resumption of respiration and very slight arousal of the individual at the end of the event.
During the resumption of respiration and the very slight arousal, one witnesses a considerable increase in the volume of respiratory gas inhaled by the individual.
Such respiratory events correspond to periods of flow restriction and are referred to as events of the ORE type, standing for Other Respiratory Events, thereby making it possible to distinguish them from apneas and hypopneas.
FIG. 3 depicts a respiratory cycle in a patient subject to sleep disorders of ORE type. As may be seen, in this case, between times t1 and t2, the respiratory volume decreases slightly relative to the normal respiratory volume (100%), reaching a respiratory volume which is still greater than 50% of the normal volume, that is to say during these periods of restriction in respiration, the respiratory volume decreases less than in periods of hypopnea, thus rendering these disorders of ORE type more difficult to detect or to diagnose.
Now it is vital to be able to ensure effective detection of these periods of flow restriction corresponding to events of the ORE type if one wishes to carry out diagnosis and/or correct treatment of the respiratory sleep disorders of an individual.
Therefore, the problem which arises is that of proposing an apparatus capable of carrying out effective detection of the periods of flow restriction corresponding to events of the ORE type in an individual suffering from respiratory sleep disorders, in such a way that the doctor or the like can subsequently carry out effective diagnosis of such ORE disorders and prescribe an appropriate treatment.
An object of the present invention is to provide an apparatus for the diagnosis or the treatment of respiratory sleep disorders of a user.
Another object of the present invention is to provide a process for operating an apparatus for the diagnosis or the treatment of respiratory sleep disorders of a user.
It is precisely the periods of sleep disorders of ORE type, during which the patient experiences restrictions in respiratory volume which are smaller than those occurring during a period of apnea or of hypopnea, that the present invention makes it possible to detect effectively, in such a way as to subsequently allow a doctor, practitioner or the like to deduce, from the data gathered, a reliable cue which can be utilized to allow a diagnosis to be made and allow the implementation of effective treatment of the patient.