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US 6,626,175 B2Granted
Medical ventilator triggering and cycling method and mechanism
AssigneeRespironics, Inc.
InventorsMehdi M. Jafari, Gardner J. Kimm, Karrie McGuigan
Life of this patent
Estimating the term…
Abstract
A medical ventilator system and method that triggers, cycles, or both based on patient effort, which is determined from cross-correlating patient flow and patient pressure. The medical ventilator is also controlled such that sensitivity to a patient initiated trigger increases as the expiratory phase of the breathing cycle progresses. The present invention also provides adaptive adjustment of cycling criteria to optimize the cycling operation.
Claims46
A system for providing a flow of gas to a patient comprising:
- a pressure generating system adapted to provide a flow of gas to a patient responsive to a control signal;
- a patient circuit having a first end coupled to the pressure generating system and adapted to communicate the flow of gas with an airway of a patient;
- a flow sensor adapted to measure the flow of gas in the patient circuit and to output a first flow signal indicative thereof;
- a pressure sensor adapted to measure a pressure of the flow of gas in the patient circuit and to output a first pressure signal indicative thereof;
- an exhaust assembly adapted to communicate gas from within the patient circuit to ambient atmosphere;
- and
- a controller that receives the first flow signal and the first pressure signal and outputs the control signal that controls the flow of gas delivered to the patient circuit by the pressure generating system and, hence, the flow of gas at a patient's airway, wherein the controller detects onset of an inspiratory phase of a patient's breathing cycle for triggering an inspiratory flow of gas based on such a patient's inspiratory effort, which is determined based on a product of a flow related parameter determined from the first flow signal and a pressure related parameter determined from the first pressure signal.
4 more elements
A system for providing a flow of gas to a patient comprising:
- a pressure generating system adapted to provide a flow of gas to a patient responsive to a control signal;
- a patient circuit coupled to the pressure generating system and adapted to communicate the flow of gas with an airway of a patient;
- a flow sensor adapted to measure the flow of gas in the patient circuit and to output a first flow signal indicative thereof;
- a pressure sensor adapted to measure a pressure of the flow of gas in the patient circuit and to output a first pressure signal indicative thereof;
- an exhaust assembly adapted to communicate gas from within the patient circuit to ambient atmosphere;
- and
- a controller that receives the first flow signal and the first pressure signal and outputs the control signal that controls the flow of gas delivered to the patient circuit by the pressure generating system and, hence, the flow of gas at a patient's airway, wherein the controller arms a plurality of triggering mechanisms over an expiratory phase of a breathing cycle to increase sensitivity to a patient initiated trigger as the expiratory phase of the breathing cycle progresses.
4 more elements
A method of providing a flow of gas to a patient comprising:
- generating a flow of gas;
- providing the flow of gas to a patient via a patient circuit;
- controlling the flow of gas delivered to a patient responsive to a control signal;
- measuring the flow of gas in the patient circuit and outputting a first flow signal indicative thereof;
- measuring a pressure of the flow of gas in the patient circuit and outputting a first pressure signal indicative thereof;
- communicating gas from within the patient circuit to ambient atmosphere;
- and
- detecting onset of an inspiratory phase of a patient's breathing cycle for triggering an inspiratory flow of gas based on such a patient's inspiratory effort, which is determined based on a product of a flow related parameter determined from the first flow signal and a pressure related parameter determined from the first pressure signal.
5 more elements
A method of providing a flow of gas to a patient comprising:
- generating a flow of gas;
- providing the flow of gas to a patient via a patient circuit;
- controlling the flow of gas delivered to a patient responsive to a control signal;
- measuring the flow of in the patient circuit and outputting a first flow signal indicative thereof;
- measuring a pressure of the flow of gas in the patient circuit and outputting a first pressure signal indicative thereof;
- communicating gas from within the patient circuit to ambient atmosphere;
- and
- activating a plurality of triggering mechanisms over an expiratory phase of a breathing cycle to increase a sensitivity to a patient initiated trigger as the expiratory phase of the breathing cycle progresses.
5 more elements
A system for providing a flow of gas to a patient comprising:
- a pressure generating system adapted to provide a flow of gas to a patient responsive to a control signal;
- a patient circuit coupled to the pressure generating system and adapted to communicate the flow of gas with an airway of a patient;
- a flow sensor adapted to measure the flow of gas in the patient circuit and to output a first flow signal indicative thereof;
- a pressure sensor adapted to measure a pressure of the flow of gas in the patient circuit and to output a first pressure signal indicative thereof;
- an exhaust assembly adapted to communicate gas from within the patient circuit to ambient atmosphere;
- and
- a controller that receives the first flow signal and the first pressure signal and outputs the control signal that controls the flow of gas delivered to the patient circuit by the pressure generating system and, hence, the flow of gas at a patient's airway, wherein the controller detects onset of an expiratory phase of a patient's breathing cycle for cycling an expiratory flow of gas based on such a patient's expiratory effort, which is determined based on both the first flow signal and the first pressure signal.
4 more elements
A method of providing a flow of gas to a patient comprising:
- generating a flow of gas;
- providing the flow of gas to a patient via a patient circuit;
- controlling the flow of gas delivered to a patient responsive to a control signal;
- measuring the flow of gas in the patient circuit and outputting a first flow signal indicative thereof;
- measuring a pressure of the flow of gas in the patient circuit and outputting a first pressure signal indicative thereof;
- communicating gas from within the patient circuit to ambient atmosphere;
- and
- detecting onset of an expiratory phase of a patient's breathing cycle for cycling an expiratory flow of gas based on such a patient's expiratory effort, which is determined based on both the first flow signal and the first pressure signal.
5 more elements
A system for providing a flow of gas to a patient comprising:
- a pressure generating system adapted to provide a flow of gas to a patient responsive to a control signal;
- a patient circuit coupled to the pressure generating system and adapted to communicate the flow of gas with an airway of a patient;
- a flow sensor adapted to measure the flow of gas in the patient circuit and to output a first flow signal indicative thereof;
- a pressure sensor adapted to measure a pressure of the flow of gas in the patient circuit and to output a first pressure signal indicative thereof;
- an exhaust assembly adapted to communicate gas from within the patient circuit to ambient atmosphere;
- and
- a controller that receives the first flow signal and the first pressure signal, wherein the controller detects onset of an expiratory phase of a patient's breathing cycle, for cycling the system from providing the inspiratory flow of gas to allowing an expiratory flow of gas from the exhaust assembly, responsive to a patient flow determined from the first flow signal falling below a cycle threshold flow, wherein the controller monitors patient pressure, via the first pressure signal, at an end portion of the inspiratory phase to determine whether cycling occurred too late, and monitors patient flow, via the first flow signal, at a beginning portion of the expiratory phase to determine whether cycling occurred too early, and wherein the controller adjusts the cycle threshold flow for a next breathing cycle responsive to a determination that cycling occurred too early or too late.
4 more elements
A method of providing a flow of gas to a patient comprising:
- generating a flow of gas;
- providing the flow of gas to a patient via a patient circuit;
- controlling the flow of gas delivered to a patient responsive to a control signal;
- measuring the flow of gas in the patient circuit and outputting a first flow signal indicative thereof;
- measuring a pressure of the flow of gas in the patient circuit and outputting a first pressure signal indicative thereof;
- communicating gas from within the patient circuit to ambient atmosphere;
- and
- detecting onset of an expiratory phase of a patient's breathing cycle for cycling from providing an inspiratory flow of gas to allowing an expiratory flow of gas from the patient circuit, by comparing a patient flow determined from the first flow signal with a cycle threshold flow;
- cycling from providing the inspiratory flow of gas to allowing the expiratory flow of gas from the patient circuit responsive to the patient flow falling below the cycle threshold flow;
- determining whether cycling occurred too late based on the patient pressure at an end portion of the inspiratory phase;
- determining whether cycling occurred too early based on the patient flow at a beginning portion of the expiratory phase;
- and
- adjusting the cycle threshold flow for a next breathing cycle responsive to a determination that cycling occurred too early or too late.
10 more elements
Dependencies are inferred from the claim text.