Methods for controlling mechanical lung ventilation
View Patent ↗A method for controlling mechanical lung ventilation is described. The method may include supplying a breathing gas to an airway of a patient in an intermittent way such that a plurality of respiratory cycles are formed; measuring a volume received by the patient in one or more respiratory cycles of the plurality of respiratory cycles; comparing the measured volume of each of the one or more respiratory cycles with a user defined target volume; attributing a classifying score to each of the one or more respiratory cycles based at least partially on a deviation between the measured volume and the user defined target volume; summing the classifying scores and dividing the result by a sample size of the one or more respiratory cycles; attributing a pressure step value based at least partially on the division result; and adding the pressure step value to a present pressure.
1. A system for controlling mechanical lung ventilation, the system comprising:
one or more processors; and
a memory including instructions that, when executed by the one or more processors, cause the one or more processors to:
supply a breathing gas to an airway of a patient in an intermittent way such that a plurality of respiratory cycles are formed;
measure a volume received by the patient in each of the plurality of respiratory cycles;
compare the volume of each of the plurality of respiratory cycles with a common user defined target volume that remains constant for the plurality of respiratory cycles;
attribute a classifying score to each of the plurality of respiratory cycles, based at least partially on a deviation between the volume and the common user defined target volume, wherein the classifying score is one of a positive or a negative value indicative of a band of the deviation between the volume and the common user defined target volume; and
select a sampling size of the plurality of respiratory cycles based on a patient inspiratory effort and a volume variability.
2. The system of claim 1 , wherein the instructions that, when executed by the one or more processors, further cause the one or more processors to:
sum the classifying scores and divide a resulting sum by the sample size of the plurality of respiratory cycles to obtain a division result;
attribute a pressure step value based at least partially on the division result; and
add the pressure step value to a present pressure.
3. The system of claim 2 , wherein the sample size is automatically calculated based on a measurement of variability of breathing.
4. The system of claim 3 , wherein the instructions that, when executed by the one or more processors, further cause the one or more processors to:
calculate a Coefficient of Variation of a test sample size to determine the sample size by a following equation:
CV
=
Std
M
,
where:
CV=Coefficient of Variation; and
Std
=
Σ
(
Vt
-
M
)
2
(
Nt
-
1
)
2
,
where:
Vt=Tidal volume of each cycle;
M=Mean of all measured tidal volumes; and
Nt=Test sample size (number of cycles).
5. The system of claim 4 , wherein the instructions that, when executed by the one or more processors, further cause the one or more processors to attribute the sample size based at least partially on the Coefficient of Variation.
6. A machine-readable medium comprising instructions stored therein, which when executed by a machine, cause the machine to perform operations, the machine-readable medium comprising:
instructions for supplying a breathing gas to an airway of a patient in an intermittent way such that a plurality of respiratory cycles are formed;
instructions for measuring a volume received by the patient in each of the plurality of respiratory cycles;
instructions for comparing the volume of each of the plurality of respiratory cycles with a common user defined target volume that remains constant for the plurality of respiratory cycles;
instructions for attributing a classifying score to each of the plurality of respiratory cycles, based at least partially on a deviation between the volume and the common user defined target volume, wherein the classifying score is one of a positive or a negative value indicative of a band of the deviation between the volume and the common user defined target volume; and
selecting a sampling size of the plurality of respiratory cycles based on a patient inspiratory effort and a volume variability.
7. The machine-readable medium of claim 6 , further comprising:
instructions for summing the classifying scores and dividing a resulting sum by the sample size of the plurality of respiratory cycles to obtain a division result;
instructions for attributing a pressure step value based at least partially on the division result; and
instructions for adding the pressure step value to a present pressure.
8. The machine-readable medium of claim 7 , wherein the sample size is automatically calculated based on a measurement of variability of breathing.
9. The machine-readable medium of claim 8 , further comprising:
instructions for calculating a Coefficient of Variation of a test sample size to determine the sample size by a following equation:
CV
=
Std
M
,
where:
CV=Coefficient of Variation; and
Std
=
Σ
(
Vt
-
M
)
2
(
Nt
-
1
)
2
,
where:
Vt=Tidal volume of each cycle;
M=Mean of all measured tidal volumes; and
Nt=Test sample size (number of cycles).
10. The machine-readable medium of claim 9 , further comprising instructions for attributing the sample size based at least partially on the Coefficient of Variation.