Adaptive patient circuit compensation with pressure sensor at mask apparatus

Patent metadata

Field	Value
Publication number	US-10668236-B2
Application number	US-201314434626-A
Country	US
Kind code	B2
Filing date	Oct 10, 2013
Priority date	Oct 10, 2012
Publication date	Jun 2, 2020
Grant date	Jun 2, 2020

Abstract

Systems and methods for providing respiratory therapy overcome various effects of transport delay within tubing of a respiratory therapy device by virtue of estimating and compensating for, e.g., a pressure drop in such tubing.

First claim

The invention claimed is:

1. A system for providing respiratory therapy during a therapy session to a subject, the system comprising:
a pressure generator configured to generate a pressurized flow of breathable gas for delivery to the airway of the subject, the pressure generator having an output configured to expel the pressurized flow of breathable gas;
a subject interface configured to guide the pressurized flow of breathable gas from the output of the pressure generator to a point of delivery at or near the airway of the subject, wherein the subject interface causes a pressure drop between the output of the pressure generator and the point of delivery during delivery of the pressurized flow of breathable gas;
one or more sensors configured to generate output signals conveying information related to one or more gas parameters of the pressurized flow of breathable gas at the point of delivery at or near the airway of the subject, wherein the output signals are generated in an ongoing manner during the therapy session, and wherein a first sensor of the one or more sensors is disposed at the point of delivery at or near the airway of the subject; and
one or more processors configured to execute processing modules, the processing modules comprising:
an estimation module configured to estimate the pressure drop between the output of the pressure generator and the point of delivery during delivery of the pressurized flow of breathable gas based on the generated output signals, wherein the estimation by the estimation module is performed in an ongoing manner during the therapy session;
a target module configured to determine a target pressure for the pressurized flow of breathable gas that compensates for the dynamically estimated pressure drop, wherein the target pressure is in accordance with a therapy regimen;
a control module configured to adjust levels of one or more gas parameters of the pressurized flow of breathable gas based on the determined target pressure; and
a model module configured to adjust one or more model parameters of a parameter-based model that models the subject interface, the one or more model parameters being different than the one or more gas parameters, wherein the parameter-based model includes one or more model parameters related to pneumatic impedance of the subject interface, wherein adjustments of the one or more model parameters are performed in an ongoing manner based on the one or more gas parameters and/or the output signals during the therapy session, wherein the adjustments include correcting the one or more model parameters and/or adding one or more additional model parameters to the parameter-based model, and wherein the estimation by the estimation module is further based on the one or more adjusted model parameters of the parameter-based model.

2. The system of claim 1 , further comprising:
a subject interface appliance included in the subject interface, wherein the subject interface appliance is configured to deliver the pressurized flow of breathable gas to the airway of the subject, wherein the first sensor is disposed within the subject interface appliance,
and wherein adjustments by the control module are further based on the parameter-based model.

3. The system of claim 1 , wherein operation of the estimation module configured to estimate the pressure drop is further based on a device pressure estimation of a pressure at or near the output of the pressure generator, wherein the device pressure estimation is based on a measurement of a component of the pressure generator.

4. The system of claim 1 , further comprising:
a patient pressure module configured to determine a patient pressure at the point of delivery based on the generated output signals from the first sensor at the point of delivery;
a device pressure module configured to estimate a device pressure at the output of the pressure generator; and
an error module configured to determine a pressure error based on a difference between the target pressure and the estimated device pressure
wherein the adjustments by the model module are further based on the patient pressure and the device pressure, and wherein adjustments by the control module are further based on the pressure error.

5. The system of claim 1 , wherein the estimation module is configured to dynamically estimate the pressure drop due to flow changes caused by the subject.

6. A method for estimating a pressure drop during the provision of respiratory therapy to a subject, the method being implemented in a system including a pressure generator, a subject interface, and one or more sensors, the method comprising:
guiding a pressurized flow of breathable gas from an output of the pressure generator to a point of delivery at or near an airway of the subject via the subject interface, wherein the subject interface causes a pressure drop between the output of the pressure generator and the point of delivery during delivery of the pressurized flow of breathable gas;
generating, by a first sensor of the one or more sensors, output signals conveying information related to one or more gas parameters of the pressurized flow of breathable gas at the point of delivery at or near the airway of the subject, wherein the output signals are generated in an ongoing manner during the therapy session;
estimating the pressure drop between the output of the pressure generator and the point of delivery of the pressurized flow of breathable gas based on the generated output signals, wherein the estimation is performed dynamically in an ongoing manner during the therapy session;
determining, with a target module, a target pressure for the pressurized flow of breathable gas that compensates for the dynamically estimated pressure drop, wherein the target pressure is in accordance with a therapy regimen;
adjusting, with a control module, levels of one or more gas parameters of the pressurized flow of breathable gas based on the determined target pressure; and
adjusting one or more model parameters of a parameter-based model that models the subject interface, the one or more model parameters being different than the one or more gas parameters, wherein the parameter-based model includes one or more model parameters related to pneumatic impedance of the subject interface, and wherein adjustments of the one or more model parameters are performed in an ongoing manner based on the one or more gas parameters and/or the output signals during the therapy session, wherein the adjustments include correcting the one or more model parameters and/or adding one or more additional model parameters to the parameter-based model, and wherein the estimation by the estimation module is further based on the one or more adjusted model parameters of the parameter-based model.

7. The method of claim 6 , further wherein:
the subject interface appliance is configured to deliver the pressurized flow of breathable gas to the airway of the subject, wherein the first sensor is disposed within the subject interface appliance, and wherein adjustments by the control module are further based on the parameter-based model.

8. The method of claim 6 , wherein estimating the pressure drop is based on a device pressure estimation of a pressure at or near the output of the pressure generator, wherein the device pressure estimation is based on a measurement of a component of the pressure generator.

9. The method of claim 6 , further comprising:
generating, by a second sensor of the one or more sensors, output signals conveying information related to one or more gas parameters of the pressurized flow of breathable gas at the output of the pressure generator;
determining a patient pressure at the point of delivery based on the output

Assignees

• Koninklijke Philips Nv

Inventors

• O'Connor Nathan Francis
• Lucci Christopher Scott

Classifications

• A61M2016/0039

  in the inspiratory circuit · CPC title

• A61M16/0003

  Accessories therefor, e.g. sensors, vibrators, negative pressure · CPC title

• A61M16/161

  with means for measuring the humidity · CPC title

• A61M16/06

  Respiratory or anaesthetic masks · CPC title

• A61M2205/3344

  Measuring or controlling pressure at the body treatment site · CPC title