METHODS AND SYSTEMS FOR LEAK ESTIMATION

• US 20150107584A1
• Filed: 10/18/2013
• Published: 04/23/2015
• Est. Priority Date: 10/18/2013
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Jafari, Mehdi M., Aviano, Jeffery K., Arul, Periagounder R.
• Granted Patent: US 9,675,771 B2
• Time in Patent Office: Days
• US Class Current: 128/202.22
• CPC Class Codes: A61M 16/0051 with alarm devices
• CPC Class Codes: A61M 16/0063 Compressors
• 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 16/0833 T- or Y-type connectors, e.g. Y-piece
• CPC Class Codes: A61M 16/0875 Connecting tubes
• CPC Class Codes: A61M 16/0883 Circuit type
• CPC Class Codes: A61M 16/20 Valves specially adapted to medical respiratory devices
• CPC Class Codes: A61M 2016/0027 pressure meter
• CPC Class Codes: A61M 2016/0033 electrical
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit
• CPC Class Codes: A61M 2016/0042 in the expiratory circuit
• CPC Class Codes: A61M 2202/0208 Oxygen
• CPC Class Codes: A61M 2202/025 Helium
• CPC Class Codes: A61M 2205/15 Detection of leaks
• CPC Class Codes: A61M 2205/3331 Pressure; Flow
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: A61M 2205/505 Touch-screens; Virtual keyboard or keypads; Virtual buttons; Soft keys; Mouse touches
• CPC Class Codes: A61M 2230/06 Heartbeat rate only
• CPC Class Codes: A61M 2230/205 partial oxygen pressure (P-O2)
• CPC Class Codes: A61M 2230/42 Rate

Abstract

The systems and methods include providing, displaying, and/or utilizing leak estimation during ventilation of a patient with a ventilator. The systems and methods include providing, displaying, and/or utilizing internal leak estimation, total leak estimation, and/or external leak estimation during ventilation of a patient with a ventilator.

Claims

1. A method for determining leakage during delivery of gas from a ventilator to a patient via a ventilation tubing system, comprising:

monitoring one or more measurements of at least one of pressure and flow by a proximal sensor, wherein the proximal sensor is located at a proximate location to the patient in a patient circuit or a patient interface; and

estimating instantaneous internal leak flow of breathing gas inhaled or exhaled by the patient based on at least the one or more measurements by the proximal sensor.

2. The method of claim 1, wherein the step of estimating the instantaneous internal leak comprises:

modeling internal leakage as a first internal leakage component through a first internal orifice of fixed size and a second internal leakage component through a second internal orifice of varying size using at least the one or more measurements by the proximal sensor.

3. The method of claim 1, further comprising:

displaying the instantaneous internal leak flow.

4. The method of claim 1, further comprising:

performing the steps of claim 1 for each breath;

displaying a graph of the instantaneous internal leak flow for a predetermined number of breaths.

5. The method of claim 1, further comprising:

performing the steps of claim 1 for each breath;

averaging the instantaneous internal leak flow for a predetermined number of breathes;

displaying the averaged internal leak flow.

6. The method of claim 1, further comprising:

performing the steps of claim 1 for each computational cycle;

displaying a graph of the instantaneous internal leak flow for a predetermined number of computational cycles.

7. The method of claim 1, further comprising:

performing the steps of claim 1 for each computational cycle;

averaging the instantaneous internal leak flow for each breath;

displaying the averaged internal leak flow.

8. The method of claim 1, further comprising:

performing the steps of claim 1 for each computational cycle;

averaging the instantaneous internal leak flow for each breath;

displaying a graph of the instantaneous internal leak flow for a predetermined number of breaths.

9. The method of claim 1, further comprising:

monitoring one or more measurements of the pressure and the flow by at least one of an inspiratory sensor and an expiratory sensor;

estimating instantaneous total leak flow of the breathing gas inhaled or exhaled by the patient based at least on the one or more measurements by at least one of the inspiratory sensor and the expiratory sensor.

10. The method of claim 9, wherein the step of estimating the instantaneous total leak comprises:

modeling total leakage as a first total leakage component through a first circuit orifice of fixed size and a second total leakage component through a second circuit orifice of varying size using at least the one or more measurements by at least one of the inspiratory sensor and the expiratory sensor.

11. The method of claim 9, further comprising:

displaying the instantaneous total leak flow.

12. The method of claim 9, further comprising:

performing the steps of claim 1 and claim 8 for each computational cycle;

averaging the instantaneous internal leak flow for each breath;

averaging the instantaneous total leak flow for each breath;

displaying the averaged internal leak flow and the averaged instantaneous total leak flow.

13. The method of claim 9, further comprising:

estimating an instantaneous external leak flow based on the instantaneous total leak flow and the instantaneous internal leak flow.

14. The method of claim 13, further comprising:

displaying the instantaneous external leak flow.

15. The method of claim 9, further comprising:

estimating a leak-compensated instantaneous lung flow of the breathing gas inhaled or exhaled by the patient based on at least one of the instantaneous total leak flow and the instantaneous internal leak flow.

16. The method of claim 1, wherein the proximal sensor is located at a circuit wye.

17. The method of claim 1, further comprising:

using a function of the instantaneous internal leak flow and the instantaneous total leak flow, and a disconnect threshold to identify a tube disconnection.

18. A ventilator system comprising:

a pressure generating system that generates a flow of breathing gas;

a ventilation tubing system including a patient interface for connecting the pressure generating system to a patient;

sensors operatively coupled to the ventilation tubing system, the sensors include a proximal sensor and at least one of an inspiratory sensor and an expiratory sensor, wherein the sensors generate output indicative of at least one of flow and pressure; and

an internal leak module that estimates an internal leak flow using at least sensor output from the proximal sensor.

19. The ventilator system of claim 18, further comprising:

a total leak module estimates total leak flow based at least on output from at least one of the inspiratory sensor and the expiratory sensor.

20. The ventilator system of claim 19, further comprising:

a display that displays the internal leak flow and the total leak flow.

21. The ventilator system of claim 19, further comprising:

a display that displays the internal leak flow, the total leak flow, and an external leak flow,

wherein the total leak module estimates the external leak flow based on the instantaneous total leak flow and the instantaneous internal leak flow.

22. The ventilator system of claim 19, wherein the internal leak module estimates internal leak by modeling internal leakage as a first internal leakage component through a first internal orifice of fixed size and a second internal leakage component through a second internal orifice of varying size using sensor output from at least the output of the proximal sensor, and

wherein the total leak module estimates total leak by modeling total leakage as a first total leakage component in the ventilation tubing system through a first circuit orifice of fixed size and a second total leakage component through a second circuit orifice of varying size using at least the output from at least one of the inspiratory sensor and the expiratory sensor.

23. A non-transitory computer-readable medium having computer-executable instructions executed by a processor of a controller, the controller comprising:

an internal leak module that estimates internal leak flow based at least on sensor output from the proximal sensor; and

a total leak module that estimates total leak flow based at least on sensor output from at least one of the inspiratory sensor and the expiratory sensor.