Systems And Methods For Ventilation To Obtain A Predetermined Patient Effort

• US 20120167885A1
• Filed: 12/29/2010
• Published: 07/05/2012
• Est. Priority Date: 12/29/2010
• Status: Abandoned Application

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Nellcor Puritan Bennett LLC (Medtronic Plc)
• Inventors: Masic, Milenko, Doyle, Peter
• Application Number:
  US12/980,583
• Publication Number:
  US 20120167885A1
• Time in Patent Office: Days
• US Class Current: 128/204.23
• CPC Class Codes: A61B 5/08 Detecting, measuring or recording devices for evaluating the respiratory organs A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/087 Measuring breath flow
• CPC Class Codes: A61B 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence
• CPC Class Codes: A61B 5/7292 Prospective gating, i.e. predicting the occurrence of a physiological event for use as a synchronisation signal
• CPC Class Codes: A61M 16/0051 with alarm devices
• CPC Class Codes: A61M 16/026 specially adapted for predicting, e.g. for determining an information representative of a flow limitation during a ventilation cycle by using a root square technique or a regression analysis
• CPC Class Codes: A61M 2016/0018 electrical
• CPC Class Codes: A61M 2016/0027 pressure meter
• CPC Class Codes: A61M 2016/0036 in the breathing tube and used in both inspiratory and expiratory phase
• CPC Class Codes: A61M 2202/0208 Oxygen
• CPC Class Codes: A61M 2202/025 Helium
• CPC Class Codes: A61M 2202/0266 Nitrogen (N)
• CPC Class Codes: A61M 2205/15 Detection of leaks
• CPC Class Codes: A61M 2205/502 User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2230/005 Parameter used as control input for the apparatus
• CPC Class Codes: A61M 2230/46 Resistance or compliance of the lungs

Abstract

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.

Claims

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

^Tφ

+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:

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

^Tφ

+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:

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.