SETTING EXPIRATORY TIME IN MANDATORY MECHANICAL VENTILATION BASED ON A DEVIATION FROM A STABLE CONDITION OF END TIDAL GAS CONCENTRATIONS

• US 20080230061A1
• Filed: 03/23/2007
• Published: 09/25/2008
• Est. Priority Date: 03/23/2007
• Status: Abandoned Application

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Tham, Robert Quinyew
• Application Number:
  US11/690,618
• Publication Number:
  US 20080230061A1
• Time in Patent Office: Days
• US Class Current: 128/204.21
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/083 Measuring rate of metabolism by using breath test, e.g. measuring rate of oxygen consumption
• CPC Class Codes: A61B 5/087 Measuring breath flow
• CPC Class Codes: A61B 5/091 Measuring volume of inspired or expired gases, e.g. to determine lung capacity
• CPC Class Codes: A61B 5/145 Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissuemeasuring of blood pressure or blood flow A61B5/02; non-radiation detecting or locating of foreign bodies in blood A61B5/06
• CPC Class Codes: A61B 5/4821 Determining level or depth of anaesthesia A61B5/1106 takes precedence
• CPC Class Codes: A61M 16/0051 with alarm devices
• CPC Class Codes: A61M 16/01 specially adapted for anaesthetising A61M16/104, A61M16/18 take precedence
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 16/0833 T- or Y-type connectors, e.g. Y-piece
• CPC Class Codes: A61M 16/22 Carbon dioxide-absorbing devices ; Other means for removing carbon dioxidecartridges with absorbing substances for respiratory apparatus A62B19/00
• CPC Class Codes: A61M 2016/0036 in the breathing tube and used in both inspiratory and expiratory phase
• CPC Class Codes: A61M 2205/502 User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2230/432 partial CO2 pressure (P-CO2)
• CPC Class Codes: A61M 2230/435 partial O2 pressure (P-O2)
• CPC Class Codes: A61M 2230/437 the anaesthetic agent concentration

Abstract

A method of setting expiratory time in controlled mechanical ventilation varies a subject'"'"'s expiratory times; determines end tidal gas concentrations associated with the expiratory times; establishes a stable condition of the gas concentrations; and determines an optimal expiratory time based on a deviation from the stable condition. A device for use in controlled mechanical ventilation comprises means for the same.

Claims

1. A method of setting expiratory time in controlled mechanical ventilation, comprising:

varying a subject'"'"'s expiratory times;

determining end tidal gas concentrations associated with said expiratory times;

establishing a stable condition of said gas concentrations; and

determining an optimal expiratory time based on a deviation from said stable condition.

2. The method of claim 1, wherein said gas concentrations include one or more gases exhaled by said subject.

3. The method of claim 2, wherein at least one of said gases includes carbon dioxide.

4. The method of claim 2, wherein at least one of said gases includes oxygen.

5. The method of claim 2, wherein at least one of said gases includes nitrous oxide.

6. The method of claim 2, wherein at least one of said gases includes inhaled anesthetic agent.

7. The method of claim 1, further comprising:

decreasing said subject'"'"'s expiratory times to determine said optimal expiratory time.

8. The method of claim 7, wherein said optimal expiratory time corresponds to a smallest expiratory time associated with said deviation.

9. The method of claim 1, further comprising:

increasing said subject'"'"'s expiratory times to determine said optimal expiratory time.

10. The method of claim 9, wherein said optimal expiratory time corresponds to a smallest expiratory time associated with said deviation.

11. The method of claim 1, further comprising:

displaying at least one or more of the following on a monitor;

said expiratory times;

or

said gas concentrations.

12. The method of claim 1, wherein said expiratory times vary by predetermined amounts.

13. The method of claim 12, wherein said predetermined amounts vary over time.

14. The method of claim 1, further comprising setting additional expiratory times based on said optimal expiratory time.

15. A device for use in controlled mechanical ventilation, comprising:

means for varying a subject'"'"'s expiratory times;

means for determining end tidal gas concentrations associated with said expiratory times;

means for establishing a stable condition of said gas concentrations; and

means for determining an optimal expiratory time based on a deviation from said stable condition.