Respiratory device and method for controlling a respiratory device

• US 20110100365A1
• Filed: 12/07/2004
• Published: 05/05/2011
• Est. Priority Date: 02/10/2004
• Status: Abandoned Application

• Current Assignee: Weinmann Geräte für Medizin GmbH + Co. KG
• Original Assignee: Weinmann Geräte für Medizin GmbH + Co. KG
• Inventors: Tiemann, Björn, WEDLER, Wolfgang, Göbel, Christof
• Application Number:
  US10/588,979
• Publication Number:
  US 20110100365A1
• Time in Patent Office: Days
• US Class Current: 128/204.23
• CPC Class Codes: A61B 5/087 Measuring breath flow
• CPC Class Codes: A61B 5/4836 Diagnosis combined with treatment in closed-loop systems or methods A61B5/0036 takes precedence
• CPC Class Codes: A61M 16/0051 with alarm devices
• CPC Class Codes: A61M 16/0057 Pumps therefor
• 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 16/06 Respiratory or anaesthetic masks
• CPC Class Codes: A61M 16/0858 Pressure sampling ports
• CPC Class Codes: A61M 2016/0036 in the breathing tube and used in both inspiratory and expiratory phase

Abstract

The invention relates to a respiratory device comprising a respiratory gas source (20). a control unit (13) and a connecting device for connecting to a respiratory mask. The control unit is connected to at least one sensor (15) for detecting a measurement parameter. The inventive method controls the respiratory device. The control unit has a step generator (19) for specifying a stepped modification of the pressure that.is generated by the respiratory gas source. The sensor is configured to measure a signal that corresponds to the pressure distribution and is coupled to an analyser (18). The analyser evaluates the temporal distribution of an analysis signal that is dependent on the measuring signal and the step generator increases the pressure by a pressure step in a respiratory cycle that follows the measuring evaluation, if the analyser determines a deviation of the analysis signal from a limit value after a predeterminable time limit has elapsed following the pressure increase. The deviation must exceed a predeterminable minimum differential in order to trigger a pressure increase.

Claims

1. Ventilation device with a breathing gas source, a control unit, and a connecting device for connecting the device to a ventilation mask, where the control unit is connected to at least one sensor for detecting a test parameter, wherein

the control unit (1) has a step generator (19) for determining an at least temporary, essentially stepped change in the inspiratory pressure produced by the breathing gas source (20);

in that

the sensor (15) is designed to measure a signal corresponding to the change in pressure and is connected to an analyzer (18), which evaluates the change over time in an analysis signal dependent on the measuring signal; and

in that

the step generator (19) increases the pressure by a pressure step during a ventilation cycle following that in which measured value was evaluated if, after a predetermined time limit has elapsed following the pressure increase, the analyzer (18) determines that the analysis signal deviates from a limit value by more than a predetermined minimum difference.

2. Device according to claim 1, wherein the analyzer is designed to evaluate the changes in the ventilation volume as an analysis signal.

3. Device according to claim 1, wherein the analyzer (18) is designed to analyze a flow curve as an analysis signal.

4. Device according to claim 1, wherein the analyzer (18) is designed to detect a decrease in the maximum ventilation volume from breath to breath at constant inspiratory pressure.

5. Device according to claim 1, wherein the analyzer (18) is designed to detect a decrease in the flow occurring at a predetermined time after a sudden pressure increase.

6. Device according to claim 1, wherein the sensor (15) is designed as a flow sensor.

7. Device according to claim 1, wherein an integrator (17) is connected downstream from the sensor (15).

8. Device according to claim 1, wherein the control unit (13) lowers the pressure by a pressure step via the step generator (19) the first time a reduction of the ventilation volume following a pressure increase is not detected.

9. Device according to claim 1, wherein the control unit (13) is connected to a setpoint memory for ventilation volume setpoints.

10. Device according to claim 1, wherein the control unit (13) is connected to a square-wave generator for defining the pressure curves during the inspiration and expiration phases.

11. Device according to claim 1, wherein the control unit (13) is connected to a curve generator for defining the pressure curves during the inspiration and expiration phases.

12. Device according to claim 1, wherein the analyzer (18) evaluates a pressure difference between the inspiration phases and the expiration phases.

13. Device according to claim 1, wherein the step generator (19) lowers the expiratory pressure to increase the pressure difference.

14. Method for controlling a ventilator, in which a breathing gas source is controlled by a control unit as a function of at least one test parameter, wherein the

control unit (13) produces an at least temporary, essentially stepped change in the pressure generated by the breathing gas source (20);

in that

the sensor (15) detects a measuring signal corresponding to the change in pressure; and

in that

the change over time in an analysis signal dependent on the measuring signal is evaluated, and the inspiratory pressure is increased in a subsequent ventilation cycle whenever the analysis signal deviates from a limit value by a predetermined minimum difference at a minimum of one predetermined time.

15. Method according to claim 14, wherein a decrease in the ventilation volume relative to the ventilation volume observed immediately after a pressure increase is detected, and in that the control unit (13) increases the pressure precisely when the decrease in the ventilation volume exceeds a predetermined minimum difference after a predetermined time following the pressure increase has elapsed.

16. Method according to claim 14, wherein, following an at least approximate step-like pressure increase, the pressure curve realized during the preceding breath is maintained if a decreasing flow at essentially constant pressure is detected after a predetermined time interval following the step-like pressure increase.

17. Method according to claim 14, wherein the sensor (15) carries out a flow measurement.

18. Method according to claim 15, wherein the volume signal is produced by integration of the flow signal.

19. Method according to claim 14, wherein the pressure is lowered by a pressure step the first time a decrease in the ventilation volume following a pressure increase is not detected.

20. Method according to claim 14, wherein the control unit (13) considers a target value for the ventilation volume.

21. Method according to claim 14, wherein the ventilation pressure is controlled according to the course of a square-wave signal.

22. Method according to claim 14, wherein the ventilation pressure is varied by the control unit (13) according to a predetermined pressure curve.

23. Method according to claim 14, wherein a pressure difference between the inspiratory and expiratory pressure is determined.

24. Method according to claim 14, wherein the pressure difference is increased by lowering the expiratory pressure.

25. Method according to claim 14, wherein a pressure is changed from ventilation cycle to ventilation cycle.

26. Method according to claim 14, wherein the pressure is held constant for at least two successive inspiration phases.

27. Method according to claim 14, wherein the pressure is held constant for at least two successive expiration phases.

28. Method according to claim 14, wherein the control unit (13) decreases the pressure only when an actual value of the ventilation volume exceeds the predetermined setpoint.

29. Method according to claim 14, wherein, in a first step, the control unit (13) increases the pressure until the ventilation volume reaches the predetermined setpoint, and in that an additional pressure increase is then carried out.

30. Method according to claim 14, wherein an at least approximate square-wave form pressure increase is selected for at least a single breath.

31. Method according to claim 30, wherein the flow curve following the stepped pressure increase is analyzed for the presence of an increase to a maximum and a subsequent decelerating curve.