Ventilation method and control of a ventilator based on same

• US 20030111078A1
• Filed: 06/20/2002
• Published: 06/19/2003
• Est. Priority Date: 06/21/2001
• Status: Active Grant

• Current Assignee: Nader M. Habashi
• Original Assignee: Nader Maher Habashi
• Inventors: Habashi, Nader Maher
• Granted Patent: US 7,246,618 B2
• Time in Patent Office: Days
• US Class Current: 128/204.18
• CPC Class Codes: A61M 16/0003 Accessories therefor, e.g. sensors, vibrators, negative pressure
• CPC Class Codes: A61M 16/0069 the speed thereof being controlled by respiratory parameters, e.g. by inhalation
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 2016/003 with a flowmeter
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit
• CPC Class Codes: A61M 2016/0042 in the expiratory circuit
• CPC Class Codes: A61M 2205/3331 Pressure; Flow
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: A61M 2230/202 partial carbon oxide pressure, e.g. partial dioxide pressure (P-CO2)
• CPC Class Codes: A61M 2230/205 partial oxygen pressure (P-O2)

Abstract

The following is a description for the use of Airway Pressure Release Ventilation (APRV).

This description refers to the initiation, management, and weaning process involved during the use APRV.

Included are a description of APRV management and an APRV weaning protocol. Protocol and diagrams are provided.

The following descriptive information will provide the basis for software development to be programmed into the mechanical ventilator. The mechanical ventilator'"'"'s flow sensor provides flow rates, volumes, and duration calculations and measurements. The software algorhythms are based on the conceptual knowledge as detailed below, integrated with the measurements and calculations. The ventilator is automated to operate with the invention under software program control. The pressure and flow sensor of the ventilator will provide all necessary parameters to drive the software.

Claims

1. A method of adjusting and guiding ventilator parameters through the use of a process which comprises:

a) placing a ventilator in airway pressure release ventilation mode,

b) invasive or non-invasive methods of measuring saturation of blood and carbon dioxide levels,

c) ratio of spontaneous to machine minute ventilation,

d) level of sedation,

e) monitoring airway pressure, flow and volume to the patient,

f) calculation of parameters from the determination of airway pressure, flow and volume, and

g) establishing initial settings by using empiric values based on default settings.

2. The method of claim 1, including determining default settings comprised of:

a) input of severity and type of lung injury,

b) assessment of lung volume requirements, and

c) determination of recruitment pressure requirements.

3. The method of claim 2 is determined through ventilator measurement and monitoring of pressure, flow and volume.

4. Subsequent methods to claim 3, including adjustments based on respiratory mechanics monitored by the ventilator including airway pressure, volume and flow.

5. The method of claim 3, including determination of expiratory flow pattern as normal obstructive or restrictive.

6. The method of claim 3, including assessment of expiratory flow curve to the inflection point of the expiratory flow curve.

7. The method of claim 3, including regulation of end expiratory lung volume by duration of T low.

8. The method of claim 3, including determination of optimal flow termination based on a percentage of peak expiratory flow.

9. The method of claim 3, including determination of presence of flow turbulence.

10. The method of claim 3, including calculation ratio of spontaneous inspiratory/expiratory efforts to determine inspiratory/expiratory lung volume.

11. The method of claim 3, including lung volume requirements based on the balance of inspiratory to expiratory gas flow measurements.

12. The method of claim 11, including lung volume determination based on a percentage of inspiratory/expiratory flow during the P high phase.

13. The method of claim 3, including weaning airway pressure release ventilation settings based on:

a) saturation of blood (invasive or non invasive),

b) carbon dioxide levels (invasive or non-invasive),

c) ratio of spontaneous to machine minute ventilation and

d) level of sedation.

14. The method of claim 1 or 13, including obtaining information directly from the ventilator or determined using conventional methods.