RESPIRATOR AND A PROCESS FOR OPERATING A RESPIRATOR

• US 20090020119A1
• Filed: 04/30/2008
• Published: 01/22/2009
• Est. Priority Date: 07/19/2007
• Status: Active Grant

• Current Assignee: Dragerwerk AG & Company KGaA (FPS Vermögensverwaltung GmbH)
• Original Assignee: Drager Medical AG & Co KG (Dragerwerk AG)
• Inventors: WEISMANN, Dieter, EGER, Marcus
• Granted Patent: US 8,397,720 B2
• Time in Patent Office: Days
• US Class Current: 128/204.210
• CPC Class Codes: A61M 16/0051 with alarm devices
• 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 2016/0027 pressure meter

Abstract

Operating a respirator with an inspiration pressure-vs.-time curve (1), which has an airway target pressure (p_aw—target) and a PEEP (3), in which the inspiration pressure-vs.-time curve (1) reaches the airway target pressure (p_aw—target) on a ramp-like curve (17) starting from a starting airway pressure (p_aw—Start), which is greater than the PEEP (3).

Claims

1. A process for operating a respirator with an inspiration pressure-vs.-time curve, which curve has an airway target pressure (p_aw—

_target) and a positive end-expiratory pressure (PEEP), the process comprising the steps of;

forming the inspiration pressure-vs.-time curve from a starting airway pressure to the airway target pressure (p<sub>aw—

target</sub>) on a ramp-like pressure curve, the starting airway pressure (p<sub>aw—

Start</sub>) being greater than the PEEP.

2. A process in accordance with claim 1, further comprising:

shaping the ramp-like pressure curve on a basis of a lung disease of a patient to be respirated.

3. A process in accordance with claim 1, further comprising:

setting a desired time constant (τ

_desired) for a time dynamics of a filling of the lungs of the patient;

determining a time constant (τ

) of the lung mechanics of the patient;

calculating the ramp-like pressure curve based on the desired time constant and the time constant of the lung mechanics.

4. A process in accordance with claim 2, further comprising:

setting a desired time constant (τ

_desired) for a time dynamics of a filling of the lungs of the patient;

determining a time constant (τ

) of the lung mechanics of the patient;

calculating the ramp-like pressure curve based on the desired time constant and the time constant of the lung mechanics.

5. A process in accordance with claim 3, further comprising:

determining the time constant (τ

) of the lung mechanics by means of regression or occlusion.

6. A process in accordance with claim 3, further comprising:

setting the time constant (τ

) of the lung mechanics on a respirator.

7. A process in accordance with claim 1, further comprising:

setting the starting airway pressure (p<sub>aw—

Start</sub>);

setting a time constant for determining a change over time in the inspiration pressure applied; and

calculating the ramp-like pressure curve.

8. A process in accordance with claim 2, further comprising:

setting the starting airway pressure (p<sub>aw—

Start</sub>);

setting a time constant for determining a change over time in the inspiration pressure applied; and

calculating the ramp-like pressure curve.

9. A respirator for applying a inspiration pressure-vs.-time curve which has an airway target pressure (p_aw—

_target) and a positive end-expiratory pressure (PEEP), the respirator comprising;

means for shaping the inspiration pressure-vs.-time curve, the inspiration pressure-vs.-time curve reaching the airway target pressure (p<sub>aw—

target</sub>) on a ramp-like curve starting from a starting airway pressure (p<sub>aw—

Start</sub>), the starting airway pressure (p<sub>aw—

Start</sub>) being greater than the PEEP.

10. A respirator in accordance with claim 9, further comprising:

means for setting a desired time constant (τ

_desired) for a time dynamics of a filling of the lungs of the patient;

means for determining a time constant (τ

) of the lung mechanics of the patient;

means for calculating the ramp-like pressure curve.

11. A respirator in accordance with claim 10, further comprising:

means for determining the time constant (τ

) of the lung mechanics by means of regression and occlusion maneuvers.

12. A respirator in accordance with claim 9, further comprising:

means for setting the starting airway pressure (p<sub>aw—

Start</sub>);

means for setting a time constant for determining a change over time in the inspiration pressure applied; and

means for calculating the ramp-like pressure curve.

13. A process for mechanically ventilating a patient, the process comprising the steps of:

recording a PEEP (positive end-expiratory pressure) of the patient;

providing an inspiration pressure/time curve;

flowing breathing gas into the patient according to the inspiration pressure/time curve, the pressure/time curve transitioning from a starting airway pressure at a beginning of an inspiration stroke to an airway target pressure at an end of the inspiration stoke, the starting airway pressure being higher than the PEEP.

14. A process in accordance with claim 13, further comprising:

determining a lung disease of the patient;

shaping the pressure/time curve on a basis of the lung disease of the patient.

15. A process in accordance with claim 13, further comprising:

setting a desired time constant (τ

_desired) for filling of the lungs of the patient;

determining an actual time constant (τ

) of the lung mechanics of the patient;

shaping the pressure/time curve on based on the desired and actual time constant.

16. A process in accordance with claim 15, further comprising:

determining the actual time constant (τ

) of the lung mechanics by means of one of regression and occlusion.

17. A process in accordance with claim 15, further comprising:

setting the actual time constant (τ

) of the lung mechanics on a respirator.