Leak-compensated flow triggering and cycling in medical ventilators
First Claim
1. A method of compensating for leakage in a ventilation system during delivery of gas from a medical ventilator to a patient comprising:
- monitoring an instantaneous flow at a location in the ventilation system based on one or more measurements of pressure and flow in the ventilation system;
modeling leakage as a first leakage component through a first orifice of a fixed size and a second leakage component through a second orifice of a varying size, wherein the first and second leakage components are different functions of instantaneous pressure in the ventilation system;
estimating a leak-compensated instantaneous lung flow of gas inhaled or exhaled by the patient based on the one or more measurements, the first leakage component and second leakage component; and
using the leak-compensated instantaneous lung flow and a threshold to identify patient-initiated transitions into inhalation or exhalation.
2 Assignments
0 Petitions
Accused Products
Abstract
This disclosure describes systems and methods for compensating for inelastic and elastic leaks in a ventilation system. The disclosure describes a model-based enhancement to conventional flow triggering and cycling methodologies that improves the timing and patient work of flow-based triggering and cycling performance. The methods and systems described herein compensate for the leak condition and minimize additional effort a patient has to exert to generate the same patient synchrony and comfort level compared to no leak condition. One method described includes calculating an elastic leakage and an inelastic leakage based on current measurements of pressure and flow in the ventilation system and then estimating a leak-compensated lung flow using the inelastic and elastic leaks and pneumatic attributes of the patient-ventilator system.
-
Citations
21 Claims
-
1. A method of compensating for leakage in a ventilation system during delivery of gas from a medical ventilator to a patient comprising:
-
monitoring an instantaneous flow at a location in the ventilation system based on one or more measurements of pressure and flow in the ventilation system; modeling leakage as a first leakage component through a first orifice of a fixed size and a second leakage component through a second orifice of a varying size, wherein the first and second leakage components are different functions of instantaneous pressure in the ventilation system; estimating a leak-compensated instantaneous lung flow of gas inhaled or exhaled by the patient based on the one or more measurements, the first leakage component and second leakage component; and using the leak-compensated instantaneous lung flow and a threshold to identify patient-initiated transitions into inhalation or exhalation. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A method of compensating for leakage in a ventilation tubing system during delivery of gas from a medical ventilator to a patient comprising:
-
identifying an inelastic leakage in the ventilation system as a first function of at least one of a pressure measurement and a flow measurement in the ventilation system; identifying an elastic leakage in the ventilation system as a second function of at least one of the pressure measurement and the flow measurement in the ventilation system; estimating compliance and resistance of the ventilation tubing system; and transitioning the medical ventilator between inhalation and exhalation based on the inelastic leakage, the elastic leakage, the compliance and resistance and the at least one of the pressure measurement and the flow measurement in the ventilation system. - View Dependent Claims (12, 13)
-
-
14. A pressure support system comprising:
-
a pressure generating system adapted to generate a flow of breathing gas; a ventilation system including a patient interface device; one or more sensors operatively coupled to the pressure generating system or the ventilation system, each sensor capable of generating an output indicative of a pressure of the breathing gas; a processor; an elastic leak estimation module that identifies an elastic leakage in the ventilation system; and a compensation module that generates a leak-compensated lung flow based on the elastic leakage and at least one output indicative of a pressure of the breathing gas. - View Dependent Claims (15, 16, 17, 18)
-
-
19. A controller for a medical ventilator comprising:
-
a microprocessor; and a lung flow estimation means that adjusts a ventilator net flow threshold based on; identifying an instantaneous elastic leakage in the ventilation system as a first function of at least one of a pressure measurement and a flow measurement in the ventilation system; and identifying an instantaneous inelastic leakage in the ventilation system as a second function of at least one of a pressure measurement and a flow measurement in the ventilation system. - View Dependent Claims (20, 21)
-
Specification