System and method for circuit compliance compensated pressure-regulated volume control in a patient respiratory ventilator
First Claim
1. A circuit compliance compensated pressure regulated volume control system in a patient respiratory ventilation system, comprising:
- a circuit compliance estimator, to provide a relationship between a circuit volume V cc and a differential pressure Δ
PY between a circuit pressure PY and a positive end expiratory pressure (PEEP) for a patient circuit used in the ventilation system;
a circuit volume estimator, operative to estimate a circuit volume VOLCKT—
EST distributed to the patient circuit based on the relationship provided by the circuit compliance estimator;
a patient volume observer, operative to provide an estimated patient volume VOLTID—
EST by subtracting the estimated circuit volume from a measured machine delivered net volume VOLNET; and
a pressure-regulated volume controller, operative to update a peak airway pressure PSET based on the estimated patient volume VOLTID—
EST and a set tidal volume VOLTID—
SET.
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Accused Products
Abstract
A system and a method for circuit compliance compensated pressure control in a patient respiratory ventilation system, having a pressure regulated feedback servo control loop, a pressure-regulated volume controller, and a patient volume observer. The patient volume observer is operative to estimate a patient volume, that is, the volume actually delivered to the patient by accounting for volume deviation or loss caused by patient circuit leakage and valve dynamics. Based on the difference between the estimated patient volume and a set tidal volume, the pressure-regulated volume controller is operative to generate and update a circuit compliance pressure compensation factor. The pressure regulated feedback servo control loop is operative to modulate the peak airway pressure based on the circuit compliance pressure compensation factor, so as to achieve the set tidal volume while maintaining a constant inspiratory time and a constant I:E ratio.
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Citations
48 Claims
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1. A circuit compliance compensated pressure regulated volume control system in a patient respiratory ventilation system, comprising:
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a circuit compliance estimator, to provide a relationship between a circuit volume V cc and a differential pressure Δ
PY between a circuit pressure PY and a positive end expiratory pressure (PEEP) for a patient circuit used in the ventilation system;a circuit volume estimator, operative to estimate a circuit volume VOLCKT — EST distributed to the patient circuit based on the relationship provided by the circuit compliance estimator;a patient volume observer, operative to provide an estimated patient volume VOLTID — EST by subtracting the estimated circuit volume from a measured machine delivered net volume VOLNET; anda pressure-regulated volume controller, operative to update a peak airway pressure PSET based on the estimated patient volume VOLTID — EST and a set tidal volume VOLTID— SET. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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29. A circuit compliance compensated pressure regulated volume control system in a patient respiratory ventilation system, comprising:
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a patient volume provider operative to provide a measured or estimated patient volume VOLTID — Y or VOLTID— EST, wherein the estimated patient volume is computed based on a measured machine delivered net volume VOLNET and a circuit compliance CT of a patient circuit applied to a patient; anda pressure-regulated volume controller, operative to generate a circuit compliance compensation pressure factor PRSTID — CTL for offsetting an airway peak pressure,wherein the circuit compliance compensation pressure factor PRSTID — CTL is generated based on a difference between the patient volume VOLTID— Y or VOLTID— EST and a set tidal volume VOLTID— SET. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36)
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37. A method for circuit compliance compensated pressure regulated volume control in a patient respiratory ventilation system, comprising:
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a) measuring a patient volume VOLTID — Y with a VOLTID— Y circuit through a flow sensor installed at a patient piece of a patient circuit in the ventilation system, or estimating a patient volume VOLTID— EST with a VOLTID— EST circuit based on a machine delivered net volume VOLNET and a circuit compliance CT of the patient circuit; andb) predetermining, an initial value INC_CKT _PRS for a circuit compliance pressure compensation factor PRSTID — CTL and updating the circuit compliance pressure compensating factor PRSTID— CTL based on a set tidal volume VOLTID— SET and the patient volume VOLTID— Y or VOLTID— EST for each breath. - View Dependent Claims (38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48)
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Specification