Methods and systems for an optimized proportional assist ventilation

• US 9,993,604 B2
• Filed: 04/27/2012
• Issued: 06/12/2018
• Est. Priority Date: 04/27/2012
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Doyle, Peter, Jafari, Mehdi M.
• Primary Examiner(s): Ho, Tan-Uyen (Jackie) T
• Assistant Examiner(s): Boecker, Joseph D
• Application Number:
  US13/457,733
• Publication Number:
  US 20130284172A1
• Time in Patent Office: 2,237 Days
• CPC Class Codes: A61M 16/0051 with alarm devices
• CPC Class Codes: A61M 16/0063 Compressors
• CPC Class Codes: A61M 16/026 specially adapted for predicting, e.g. for determining an information representative of a flow limitation during a ventilation cycle by using a root square technique or a regression analysis
• CPC Class Codes: A61M 16/0833 T- or Y-type connectors, e.g. Y-piece
• CPC Class Codes: A61M 2016/0021 with a proportional output signal, e.g. from a thermistor
• CPC Class Codes: A61M 2016/0027 pressure meter
• CPC Class Codes: A61M 2016/0033 electrical
• CPC Class Codes: A61M 2205/502 User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2230/46 Resistance or compliance of the lungs

Abstract

This disclosure describes systems and methods for providing an optimized proportional assist breath type during ventilation of a patient. The disclosure describes a novel breath type that delivers a target airway pressure calculated based on a desired patient effort range to a triggering patient.

Claims

1. A ventilator system comprising:

a pressure generating system, wherein the pressure generating system generates a flow of breathing gas;

a ventilation tubing system including a patient interface for connecting the pressure generating system to a patient;

one or more sensors operatively coupled to at least one of the pressure generating system, the patient, and the ventilation tubing system, wherein the one or more sensors generate output indicative of an inspiration flow;

a support module that receives an initial percent support setting and a desired patient effort range, wherein the support module calculates at least one adjusted percent support setting based at least on determining that a current patient effort falls outside of the desired patient effort range, wherein the at least one adjusted percent support setting is calculated to cause the current patient effort to fall within the desired patient effort range when utilized to calculate an adjusted target airway pressure for delivery to the patient; and

an optimized proportional assist (OPA) module, the OPA module calculates an initial target airway pressure based at least on the initial percent support setting, calculates at least one adjusted target airway pressure based at least on the at least one adjusted percent support setting, and utilizes the output indicative of the inspiration flow to determine a patient trigger for delivery of a breath to the patient,

wherein the pressure generating system delivers the initial target airway pressure to the patient in response to receiving the initial target airway pressure and delivers the adjusted target airway pressure to the patient in response to receiving the adjusted target airway pressure affecting patient effort.

2. The ventilator system of claim 1, further comprising:

a treatment module, the treatment module determines the desired patient effort range based on a desired treatment metric range received from operator input and adjusts at least one ventilator parameter upon determining that a current treatment metric is not within the desired treatment metric range while the current patient effort is within the desired patient effort range for at least two consecutive breaths.

3. The ventilator system of claim 2, wherein the at least one ventilator parameter is at least one of oxygen percentage, rise time, trigger sensitivity, peak flow rate, peak inspiratory pressure, tidal volume, and PEEP.

4. The ventilator system of claim 2, further comprising a display that displays at least one of the current patient effort, the desired patient effort range, the desired treatment metric range, a current treatment metric range, a RSBI, a SpO₂, a P₁₀₀, a tidal volume, a VCO₂, a respiratory rate, a spontaneous I:

E volume, a minute volume, the initial percent support setting, and the adjust percent support setting.

5. A ventilator system, comprising:

means for retrieving a desired patient effort range;

means for estimating an initial percent support setting based on the desired patient effort range;

means for calculating a current patient effort;

means for determining that the current patient effort is outside of the desired patient effort range;

means for calculating an adjusted percent support setting based on determining that the current patient effort is outside of the desired patient effort range, wherein the adjusted percent support setting is calculated to cause the current patient effort to fall within the desired patient effort range when utilized to calculate an adjusted target airway pressure for delivery to a patient;

means for calculating a target airway pressure based at least on the adjusted percent support setting; and

means for delivering the target airway pressure to the patient to affect patient effort.

6. The ventilator system of claim 5, further comprising:

means for determining that the current patient effort is within the desired patient effort range; and

means for delivering a previously delivered target airway pressure to the patient based on the means for determining that the current patient effort is within the desired patient effort range, wherein the means for delivering the target airway pressure to the patient is the same as the means for delivering the previously delivered target airway pressure.

7. The ventilator system of claim 5, further comprising:

means for receiving a desired treatment metric range from an operator;

means for determining that a current treatment metric is not within the desired treatment metric range; and

means for adjusting at least one ventilator parameter until the current treatment metric is within the desired treatment metric range,

wherein a means for determining the desired patient effort range determines the desired patient effort range based on the desired treatment metric range.

8. The ventilator system of claim 7, wherein the at least one ventilator parameter is at least one of oxygen percentage, rise time, trigger sensitivity, peak flow rate, peak inspiratory pressure, tidal volume, and PEEP.

9. The ventilator system of claim 7, wherein the desired treatment metric range is at least one of a trend and a weighted combination of at least one of RSBI, SpO₂, P₁₀₀, Oxygen index, ETCO₂, tidal volume, VCO₂, respiratory rate, spontaneous I:

E ratio, and a minute volume.

10. The ventilator system of claim 7, wherein the desired treatment metric range is a range of at least one of RSBI, SpO₂, P₁₀₀, Oxygen index, ETCO₂, tidal volume, VCO₂, respiratory rate, spontaneous I:

E ratio, and a minute volume.

11. The ventilator system of claim 5, further comprising:

means for receiving a desired treatment metric range from an operator,

wherein a means for determining the desired patient effort range determines the desired patient effort range based on the desired treatment metric range.

12. The ventilator system of claim 5, wherein the target airway pressure is calculated utilizing a following equation:

Target Pressure(t)=k[E_p∫

Q_pdt+Q_pR_p]

wherein Target Pressure (t) is an amount of pressure provided by the ventilator at time t,

wherein k is a percent support setting,

wherein E_p is a respiratory elastance of the patient,

wherein Q_p is an instantaneous flow inhaled by the patient, and

wherein R_p is a respiratory resistance of the patient.

13. The ventilator system of claim 5, wherein the desired patient effort range is received from at least one of an operator via operator selection from a group of desired patient effort ranges, the operator via an input of a desired patient effort parameter, the ventilator system calculated based on at least one of an at least one monitored patient parameter and ventilator parameters, and the ventilator system via a selection from a group of predetermined patient efforts ranges based on at least one of the at least one monitored patient parameter and the ventilator parameters.

14. The ventilator system of claim 5, wherein the desired patient effort range is from about 5 cm of H₂O to about 10 cm of H₂O.