Systems And Methods For Ventilation To Obtain A Predetermined Patient Effort
Various embodiments of the present disclosure provide systems, methods and devices for respiratory support. As one example, a ventilation system is disclosed that includes a computer readable medium including instructions executable by a processor to receive a measured pressure value and a net flow value. A patient effort value is calculated based on a relationship between patient effort, the measured pressure value and the net flow value. The instructions are further executable to calculate a gas delivery metric based on the computed patient effort to obtain a predetermined patient effort. Gas is then caused to be delivered consistent with the gas delivery metric.
1 . A ventilation system, comprising:
a processor communicably coupled to a computer readable medium, wherein the computer readable medium includes instructions executable by the processor to:
receive a measured pressure value;
receive a net flow value;
calculate a patient effort value based on a relationship between patient effort, the measured pressure value and the net flow value;
update an interim value based at least in part on the patient effort value;
calculate a computed patient effort based at least in part on the interim value;
calculate a gas delivery metric to obtain a predetermined patient effort, wherein the gas delivery metric is based on the computed patient effort value; and
cause a gas to be delivered consistent with the gas delivery metric.
2 . The system of claim 1 , wherein the gas delivery metric is selected from: pressure, and flow.
3 . The system of claim 2 , wherein the flow is selected from: patient lung flow and inlet gas flow.
4 . The system of claim 2 , wherein the pressure is selected from: lung pressure and wye pressure.
5 . The ventilation system of claim 1 , wherein the computer readable medium further includes instructions executable by the processor to:
determine an inhalation phase based on the patient effort value.
6 . The ventilation system of claim 5 , wherein the inhalation phase is indicated when the calculated patient effort value is greater than zero,
7 . The ventilation system of claim 5 , wherein the system is operable to deliver the gas during the determined inhalation phase.
8 . The ventilation system of claim 1 , wherein the patient effort value is further calculated based on a combination of one or more intermediate values calculated using the measured pressure value and the net flow value, the one or more intermediate values selected from: an estimated normalized prediction error (ε), a filtered pressure value (z), a regression vector (φ T ), and a current estimated value of a parameter vector (θ).
9 . The ventilation system of claim 1 , wherein the relationship is a parameterized system input to output relationship.
10 . The method of claim 9 , wherein the parameterized system input to -output relationship is the regression form: z=θ T φ+φ d .
11 . The method of claim 10 , wherein the parameterized system input to output relationship is derived from a transfer function.
12 . The ventilation system of claim 11 , wherein the transfer function is derived from a model:
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13 . The ventilation system of claim 1 , wherein the calculated gas delivery metric is utilized to maintain a predetermined patient effort during ventilation, wherein the gas delivery metric is based on the computed patient effort value.
14 . A method for respiratory support, the method comprising:
measuring a pressure and providing a measured pressure;
measuring an inlet flow and an outlet flow, and providing a measured net flow;
using a relationship between a first value related to the measured pressure, a second value related to the measured net flow and a third value related to patient effort to calculate a prediction of patient effort from the measured pressure and measured net flow;
updating an interim value based at least in part on the prediction of patient effort;
calculating a computed patient effort based at least in part on the interim value; and
supplying a gas based on the computed patient effort to obtain a predetermined patient effort.
15 . The method of claim 14 , wherein supplying the gas based on the computed patient effort includes supplying the gas at a pressure to obtain the predetermined patient effort.
16 . The method of claim 14 , wherein supplying the gas based on the computed patient effort includes supplying the gas at a flow to obtain the predetermined patient effort,
17 . The method of claim 14 , wherein the prediction of patient effort is further based on a combination of one or more intermediate values derived from the measured pressure and measured net flow, the one or more intermediate values selected from: an estimated normalized prediction error (ε), a filtered pressure value (z), a regression vector (φ T ), and a current estimated value of a parameter vector (θ).
18 . The method of claim 14 , wherein the second value is selected from: a filtered version of the measured net flow, and the measured net flow. 19, The method of claim 14 , wherein the first value is selected from: a filtered version of the measured pressure, and the measured pressure.
20 . The method of claim 14 , wherein the computed patient effort is a filtered patient effort signal.
21 . The method of claim 14 , wherein the computed patient effort is a linear function of a derivative of actual patient effort.
22 . The method of claim 21 , wherein the linear function includes a filter function.
23 . The method of claim 14 , wherein the relationship is a parameterized system input to output relationship.
24 . The method of claim 23 , wherein the parameterized system input to 3 output relationship is the regression form: z=θ T φ+φ d .
25 . The method of claim 24 , wherein the parameterized system input to output relationship is derived from a transfer function.
26 . The method of claim 25 , wherein the transfer function is derived from the model:
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27 . The method of claim 14 , wherein the calculated gas delivery metric is utilized to maintain a predetermined patient effort during ventilation, wherein the gas delivery metric is based on the computed patient effort value
28 . A ventilation system, the system comprising:
a gas inlet;
a gas outlet;
a tube coupling the gas inlet and the gas outlet;
a pressure sensor, wherein the pressure sensor is operable to provide a measured pressure value indicating a pressure in the tube;
a first flow sensor, wherein the first flow sensor is operable to provide an inlet flow value indicating a flow associated with the gas inlet;
a second flow sensor, wherein the second flow sensor is operable to provide an outlet flow value indicating a flow associated with the gas outlet; and
a processor communicably coupled to a computer readable medium, wherein the computer readable medium includes instructions executable by the processor to:
receive a measured pressure value;
receive a net flow value;
calculate a patient effort value based on a relationship between patient effort, the measured pressure value and the net flow value;
update an interim value based at least in part on the patient effort value;
calculate a computed patient effort based at least in part on the interim value;
calculate a gas delivery metric based on the computed patient effort to obtain a predetermined patient effort;
determine an inhalation phase based on the computed patient effort; and
cause a gas to be delivered consistent with the gas delivery metric.
29 . A ventilation system, the system comprising:
means for measuring a pressure and providing a measured pressure;
means for measuring an inlet flow and an outlet flow, and providing a measured net flow;
means for using a relationship between a first value related to the measured pressure, a second value related to the measured net flow and a third value related to patient effort to calculate a prediction of patient effort from the measured pressure and measured net flow;
means for updating an interim value based at least in part on the prediction of patient effort;
means for calculating a computed patient effort based at least in part on the interim value; and
means for supplying a gas based on the computed patient effort to maintain a predetermined patient effort.