Adjustment of ventilator pressure-time profile to balance comfort and effectiveness
AssigneeResMed Limited
InventorsMichael Berthon-Jones, Peter Bateman, Gordon Malouf
Life of this patent
Estimating the term…
Abstract
The invention is a ventilator whose servo-controller adjusts the degree of support by adjusting the profile of the pressure waveform as well as the pressure modulation amplitude. As the servo-controller increases the degree of support by increasing the pressure modulation amplitude, it also generates a progressively more square, and therefore efficient, pressure waveform; when the servo-controller decreases the degree of support by decreasing the pressure modulation amplitude, it also generates a progressively more smooth and therefore comfortable pressure waveform.
Claims56
A method for controlling a pressure support ventilator comprising the steps of:
- supplying breathable gas to a patient's airway at a pressure that varies during each respiratory cycle in accordance with an adjustable pressure waveform template,
- determining the adequacy of the patient's ventilation, and
- automatically changing the shape of said pressure waveform in accordance with said adequacy, wherein said change in shape produces an increase in ventilatory support at the expense of comfort when the ventilation is inadequate, and produces a more comfortable waveform at the expense of a decrease in ventilatory support when ventilation is excessive.
A method for controlling a patient ventilator comprising the steps of:
- supplying air to a patient's airway at a pressure that varies during each respiratory cycle in accordance with an adjustable pressure waveform template,
- repeatedly determining from the supplied airflow the adequacy of the patient's ventilation, and
- changing said adjustable pressure waveform template in a predetermined manner in accordance with the determined adequacy of ventilation, the changes controlling an increase in ventilatory support at the expense of comfort when more support is required and controlling a decrease in ventilatory support for the greater comfort of the patient when less support is required.
A method for controlling a pressure support servo ventilator comprising the steps of:
- supplying air to a patient's airway at a pressure that varies during each respiratory cycle, the pressure being characterized by both a pressure modulation amplitude and an adjustable pressure waveform, and
- controlling both said pressure modulation amplitude and the profile of said adjustable pressure waveform by the output of a servo-controller operated to servo-control patient ventilation to at least equal a target value.
A method for controlling a pressure support ventilator comprising the steps of:
- supplying air to a patient's airway at a pressure that varies during each respiratory cycle, the pressure being characterized by both a pressure modulation amplitude and an adjustable pressure waveform of adjustable shape,
- deriving a measure of instantaneous patient ventilation, and
- controlling both said pressure modulation amplitude and the shape of said adjustable pressure waveform in accordance with said measure of patient ventilation.
A pressure support ventilator comprising a supply of air for a patient's airway whose pressure varies during each respiratory cycle in accordance with an adjustable pressure-versus-time waveform, a controller for determining from the supplied airflow the patient's ventilatory requirements, and means for changing the shape of said pressure-versus-time waveform in accordance with the determined ventilatory requirements, the waveform controlling an increase in ventilatory support at the expense of comfort when more support is required and controlling a decrease in ventilatory support for the greater comfort of the patient when less support is required.
A pressure support ventilator comprising a supply of air for a patient's airway whose pressure varies during each respiratory cycle as a predetermined function of time, a controller for continuously determining from the supplied airflow the patient's ventilatory requirements, and means for continuously changing said predetermined function of time in a predetermined manner in accordance with the determined ventilatory requirements, the changes controlling an increase in ventilatory support at the expense of comfort when more support is required and controlling a decrease in ventilatory support for the greater comfort of the patient when less support is required.
A pressure support ventilator comprising a supply of air for a patient's airway whose pressure varies during each respiratory cycle, the pressure being characterized by both a pressure modulation amplitude and an adjustable pressure waveform, and means for controlling both said pressure modulation amplitude and the profile of said adjustable pressure waveform by the output of a servo-controller operable to servo-control patient ventilation to at least equal a target.
A pressure support ventilator comprising a supply of air for a patient's airway whose pressure varies during each respiratory cycle, the pressure being characterized by both a pressure modulation amplitude and an adjustable pressure waveform, means for deriving a measure of instantaneous patient ventilation, and means for controlling both said pressure modulation amplitude and the profile of said adjustable pressure waveform in accordance with said measure of patient ventilation.
A method for providing positive pressure ventilation comprising the steps of:
- supplying a patient with breathable gas at a pressure which is a function of at least the phase in the respiratory cycle, an amplitude, and a smoothness parameter;
- determining the subject's ventilation;
- and
- adjusting said smoothness parameter within a preset range to servo-control said ventilation to at least equal a target ventilation.
A pressure support ventilator comprising a supply of air for a patient's airway whose pressure is a function of at least a measure of the phase in the patient's respiratory cycle, an amplitude, and a smoothness parameter.
Dependencies are inferred from the claim text.