Abstract: A method for controlling oxygen mix for a single-limb non-invasive ventilator comprising a pressure controller, and both a blower and a pressurized oxygen source downstream of the blower, each comprising a controller and a flow valve controlling flow, comprising: (i) generating a flow trajectory; (ii) providing the generated flow trajectory to a pair of complimentary flow coupling filters comprising a blower flow coupling filter and an oxygen flow coupling filter; (iii) generating an output from each of the filters, comprising an input flow trajectory for the blower flow controller and an input flow trajectory for the oxygen flow controller; and (iv) adjusting, by the blower flow controller and/or oxygen flow controller based on the input flow trajectory, target pressure, and oxygen mix, the blower speed controller and/or the pressurized oxygen source proportional flow valve.

Abstract: A system for controlling a valve disposed in fluid communication with a fluid circuit is provided. The system includes a flow sensor configured to determine a measured flow and a pressure sensor configured to determine a measured pressure of fluid flowing from the fluid circuit to the valve. The system includes an adaptive controller configured to determine a desired flow based at least on the measured pressure, the measured flow, and a target pressure; determine a flow error as a difference between the desired flow and the measured flow; and determine a desired position of the valve based on the flow error, such that the flow error is reduced. The system includes a position controller configured to determine an actuating electric parameter based at least on the desired position and a valve actuator configured to apply an actuating force on the valve based at least on the actuating electric parameter.

Abstract: A method (800) for estimating patient airway flow in a non-invasive ventilator system includes: (i) determining (830) an estimated gas flow; (ii) determining (840) a proximal pressure error value; (iii) compensating (850) for the determined proximal pressure estimate error value; (iv) compensating (854) for an error in the estimated gas flow; (v) determining (856) an estimated gas flow leak; (vi) monitoring (860) on a breath to breath basis for a leak; (vii) determining (870) a gas flow leak factor; (viii) adjusting (880) the estimated gas flow leak; (ix) detecting (872) a bias on the airway flow estimate; (x) determining (874) that the system is within a quiescent state of a breath; (xi) de -biasing (976) the estimated gas flow to drive the bias to near zero; and (xii) suspending (878) breath to breath bias correction on an immediately subsequent breath.

Abstract: A method (200) for determining compliance of a connecting circuit in a non-invasive ventilator system. The method includes the steps of: (i) providing (210) a non-invasive ventilator system, the system having a flow or pressure controller; (ii) generating (220) a test signal for the flow or pressure controller; (iii) exciting (230) the flow or pressure controller with the generated test signal for a predetermined time period; (iv) obtaining (240), during the excitation of the flow or pressure controller, one or more measurements of the non-invasive ventilator system; (v) determining (250) a vector of the obtained measurements; and (vi) processing (260) the vector to determine an estimate of a physical parameter of the circuit.

Abstract: A method for estimating patient airway flow in a non-invasive ventilator system. The method includes the steps of (i) determining an estimated gas flow at the proximal end of the tubing; (ii) determining a proximal pressure error value by subtracting the measured pressure at the proximal end of the tubing from the estimated pressure at the proximal end of the tubing; (iii) compensating for the determined proximal pressure estimate error value; (iv) compensating for an error in the estimated gas flow at the proximal end of the tubing by feeding the estimate back into a sum of accumulated flows; (v) determining an estimated gas flow leak; (vi) monitoring for a leak in the non-invasive ventilator system; (vii) determining a gas flow leak factor; (viii) adjusting the estimated gas flow leak; and (ix) compensating for bias in the patient airway flow.

Abstract: A method for controlling oxygen mix for a single-limb non-invasive ventilator comprising a pressure controller, and both a blower and a pressurized oxygen source downstream of the blower, each comprising a controller and a flow valve controlling flow, comprising: (i) generating a flow trajectory; (ii) providing the generated flow trajectory to a pair of complimentary flow coupling filters comprising a blower flow coupling filter and an oxygen flow coupling filter; (iii) generating an output from each of the filters, comprising an input flow trajectory for the blower flow controller and an input flow trajectory for the oxygen flow controller; and (iv) adjusting, by the blower flow controller and/or oxygen flow controller based on the input flow trajectory, target pressure, and oxygen mix, the blower speed controller and/or the pressurized oxygen source proportional flow valve.

Abstract: A ventilator (100) configured to control a pressure and gas mixture for an air flow. The ventilator include: a gas source (220); a proportional valve (210) configured to control a gas flow rate from the gas source; a mix controller (170) in communication with the proportional valve, the mix controller configured to monitor a flow of gas through the blower, and further configured to control a percentage of oxygen in the output flow; a blower motor (160); and a blower motor controller (162) configured to control a speed of the blower motor using a current feedback loop, a blower speed feedback loop, a flow feedback loop, and a pressure feedback loop. The ventilator can also include, for example, a pseudo-derivative feedback compensator, a complimentary filter, and/or a speed controller.

Abstract: A method (400) for controlling a proportional valve. The method includes the steps of: (i) providing (410) a proportional flow valve system that includes: a closed loop flow controller (110) including a proportional flow control valve (140), a flow sensor (150), and an adjustable gain (180); and an adaptive controller (120) including a model (160) of the closed loop flow controller, and a gain control (170); (ii) actuating (420) the proportional flow control valve; (iii) measuring (430) actual gas flow; (iv) determining (440) a difference between the measured gas flow rate and a desired gas flow rate; (v) adjusting (450) the proportional flow valve using the determined difference; (vi) initiating (460) a response from the model of the closed loop flow controller; (vii) determining (470) a gain for the closed loop flow controller; and (viii) adjusting (480) the adjustable gain of the closed loop flow controller.

Abstract: A method (800) for estimating patient airway flow in a non-invasive ventilator system includes: (i) determining (830) an estimated gas flow; (ii) determining (840) a proximal pressure error value; (iii) compensating (850) for the determined proximal pressure estimate error value; (iv) compensating (854) for an error in the estimated gas flow; (v) determining (856) an estimated gas flow leak; (vi) monitoring (860) on a breath to breath basis for a leak; (vii) determining (870) a gas flow leak factor; (viii) adjusting (880) the estimated gas flow leak; (ix) detecting (872) a bias on the airway flow estimate; (x) determining (874) that the system is within a quiescent state of a breath; (xi) de -biasing (976) the estimated gas flow to drive the bias to near zero; and (xii) suspending (878) breath to breath bias correction on an immediately subsequent breath.

Abstract: A method (400) for controlling a proportional valve. The method includes the steps of: (i) providing (410) a proportional flow valve system that includes: a closed loop flow controller (110) including a proportional flow control valve (140), a flow sensor (150), and an adjustable gain (180); and an adaptive controller (120) including a model (160) of the closed loop flow controller, and a gain control (170); (ii) actuating (420) the proportional flow control valve; (iii) measuring (430) actual gas flow; (iv) determining (440) a difference between the measured gas flow rate and a desired gas flow rate; (v) adjusting (450) the proportional flow valve using the determined difference; (vi) initiating (460) a response from the model of the closed loop flow controller; (vii) determining (470) a gain for the closed loop flow controller; and (viii) adjusting (480) the adjustable gain of the closed loop flow controller.

Abstract: A ventilator (100) configured to control a pressure and gas mixture for an air flow. The ventilator include: a gas source (220); a proportional valve (210) configured to control a gas flow rate from the gas source; a mix controller (170) in communication with the proportional valve, the mix controller configured to monitor a flow of gas through the blower, and further configured to control a percentage of oxygen in the output flow; a blower motor (160); and a blower motor controller (162) configured to control a speed of the blower motor using a current feedback loop, a blower speed feedback loop, a flow feedback loop, and a pressure feedback loop. The ventilator can also include, for example, a pseudo-derivative feedback compensator, a complimentary filter, and/or a speed controller.

Abstract: A method (200) for determining compliance of a connecting circuit in a non-invasive ventilator system. The method includes the steps of: (i) providing (210) a non-invasive ventilator system, the system having a flow or pressure controller; (ii) generating (220) a test signal for the flow or pressure controller; (iii) exciting (230) the flow or pressure controller with the generated test signal for a predetermined time period; (iv) obtaining (240), during the excitation of the flow or pressure controller, one or more measurements of the non-invasive ventilator system; (v) determining (250) a vector of the obtained measurements; and (vi) processing (260) the vector to determine an estimate of a physical parameter of the circuit.

Abstract: A method (600) for estimating patient airway flow in a non-invasive ventilator system. The method includes the steps of: (i) determining (630) an estimated gas flow at the proximal end of the tubing; (ii) determining (640) a proximal pressure error value by subtracting the measured pressure at the proximal end of the tubing from the estimated pressure at the proximal end of the tubing; (iii) compensating for the determined proximal pressure estimate error value; (iv) compensating (654) for an error in the estimated gas flow at the proximal end of the tubing by feeding the estimate back into a sum of accumulated flows; (v) determining (656) an estimated gas flow leak; (vi) monitoring (660) for a leak in the non-invasive ventilator system; (vii) determining (670) a gas flow leak factor; (viii) adjusting (680) the estimated gas flow leak; and (ix) compensating (690) for bias in the patient airway flow.