Methods and systems for leak estimation

• US 9,675,771 B2
• Filed: 10/18/2013
• Issued: 06/13/2017
• 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., Arul, Periagounder R., Aviano, Jeffery K.
• Primary Examiner(s): Philips, Bradley
• Assistant Examiner(s): Leszczak, Victoria
• Application Number:
  US14/057,610
• Publication Number:
  US 20150107584A1
• Time in Patent Office: 1,334 Days
• 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 ventilation of a patient, comprising:

delivering, with a ventilator, breathing gas from the ventilator to the patient via a ventilation tubing system;

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

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;

estimating, as performed by the ventilator, instantaneous internal leak flow of the breathing gas inhaled or exhaled by the patient based on at least the one or more measurements by the proximal sensor, wherein the step of estimating the instantaneous internal leak flow includes;

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; and

displaying the instantaneous internal leak flow on a display.

2. The method of claim 1, further comprising:

utilizing the instantaneous internal leak flow determined by the ventilator for an event detection.

3. The method of claim 1, further comprising:

performing the steps of claim 1 during a breath;

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

4. The method of claim 1, further comprising:

performing the steps of claim 1 during a breath;

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

displaying the averaged internal leak flow.

5. The method of claim 1, further comprising:

performing the steps of claim 1 in a computational cycle;

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

6. The method of claim 1, further comprising:

performing the estimating of the instantaneous internal leak flow in a computational cycle;

averaging the instantaneous internal leak flow for every computational cycle in a breath;

wherein the displaying the instantaneous internal leak flow comprises displaying the averaged internal leak flow.

7. The method of claim 1, further comprising:

performing the estimating of the instantaneous internal leak flow in a computational cycle;

averaging the instantaneous internal leak flow for every computational cycle in a breath;

wherein the displaying the instantaneous internal leak flow comprises displaying a graph of the instantaneous internal leak flow as averaged for a predetermined number of breaths.

8. The method of claim 1, 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.

9. The method of claim 1, further comprising:

displaying the instantaneous total leak flow.

10. The method of claim 1, further comprising:

performing the steps of claim 8;

averaging the instantaneous internal leak flow for every computational cycle in a breath;

averaging the instantaneous total leak flow for each breath;

wherein the displaying the instantaneous internal leak flow comprises displaying the averaged internal leak flow; and

displaying the averaged instantaneous total leak flow.

11. The method of claim 1, further comprising:

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

12. The method of claim 11, further comprising:

displaying the instantaneous external leak flow.

13. The method of claim 1, 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.

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

15. 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.

16. A method for determining leakage during ventilation of a patient, comprising:

delivering, with a ventilator, breathing gas from the ventilator to the patient via a ventilation tubing system;

monitoring one or more measurements of pressure and 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;

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

estimating, as performed by the ventilator, instantaneous internal leak flow of the breathing gas inhaled or exhaled by the patient based on at least the one or more measurements by the proximal sensor, wherein the step of estimating the instantaneous internal leak flow includes;

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; and

detecting an event, by the ventilator, based at least on the instantaneous internal leak flow.

17. The method of claim 16, wherein the event is a patient trigger.

18. The method of claim 16, wherein the event is a patient cycle.

19. The method of claim 16, wherein the event is a breath phase transition.

20. The method of claim 16, wherein the event is a patient interface disconnection.