Method for detecting the respiratory phases of a patient during an assisted ventilating process
First Claim
1. A method for detecting the respiratory phases of a patient for controlling a ventilating apparatus, the method comprising the steps of:
- determining the time-dependent trace of a signal supplied by a signal device with said signal representing a respiratory flow curve which crosses zero with each change in flow direction so as to provide sequential zero crossovers and which has a changing slope between each two successive ones of the zero crossovers;
determining a trigger criterium from said trace for switching over the ventilating apparatus from the expiration phase to the inspiration phase and/or from the inspiration phase to the expiration phase by examining said trace to locate a significant increase in the slope within each time interval having a start which lies after each one of said zero crossovers and which ends at the next zero crossover; and
,utilizing each of said significant increases in said slope as said trigger criterium.
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Abstract
The invention relates to a method for recognizing the respiratory phases of a patient for controlling a ventilating apparatus. The time-dependent trace of a signal, which represents the respiratory flow curve and is emitted by a signal device, is determined and from this trace, a trigger criterium is obtained for the switchover of the ventilating apparatus from the expiration phase into the inspiration phase and/or from the inspiration phase into the expiration phase. The method is improved in that even for chronically obstructive patients, a reliable and early recognition of the inspiration and expiration attempts is possible. A significant increase of the slope of the respiratory flow curve between each two zero crossovers of this curve is used as a trigger criterium.
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9 Claims
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1. A method for detecting the respiratory phases of a patient for controlling a ventilating apparatus, the method comprising the steps of:
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determining the time-dependent trace of a signal supplied by a signal device with said signal representing a respiratory flow curve which crosses zero with each change in flow direction so as to provide sequential zero crossovers and which has a changing slope between each two successive ones of the zero crossovers; determining a trigger criterium from said trace for switching over the ventilating apparatus from the expiration phase to the inspiration phase and/or from the inspiration phase to the expiration phase by examining said trace to locate a significant increase in the slope within each time interval having a start which lies after each one of said zero crossovers and which ends at the next zero crossover; and
,utilizing each of said significant increases in said slope as said trigger criterium. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification