METHOD AND DEVICE FOR CARRYING OUT A SIGNAL-PROCESSING VIEWING OF A MEASUREMENT SIGNAL THAT IS CORRELATED TO THE RESPIRATORY ACTIVITY OF AN INDIVIDUAL

• US 20140290656A1
• Filed: 04/09/2014
• Published: 10/02/2014
• Est. Priority Date: 10/17/2002
• Status: Active Grant

• Current Assignee: ResMed Humidification Technologies GmbH (ResMed Incorporated)
• Original Assignee: ResMed R&D Germany GmbH (ResMed Incorporated)
• Inventors: MEIER, Jorg, HEIDMANN, Dieter, MADAUS, Stefan Rolf, SCHNEIDER, Hartmut
• Granted Patent: US 9,808,590 B2
• Time in Patent Office: Days
• US Class Current: 128/204.23
• CPC Class Codes: A61B 5/085 Measuring impedance of respiratory organs or lung elasticity
• 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: A61B 5/7239 using differentiation including higher order derivatives
• CPC Class Codes: A61B 5/7275 Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor
• CPC Class Codes: A61B 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence
• CPC Class Codes: A61F 5/56 Devices for preventing snoring by influencing the respiratory system by gas treatment A61M16/00
• 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 2016/0018 electrical
• CPC Class Codes: A61M 2016/0033 electrical
• CPC Class Codes: A61M 2016/0036 in the breathing tube and used in both inspiratory and expiratory phase
• CPC Class Codes: A61M 2230/005 Parameter used as control input for the apparatus

Abstract

The invention relates to a method and device for carrying out a signal-processing viewing of a measurement signal that is correlated with the respiratory activity of an individual, for example, of a measurement signal that is correlated with the respiratory gas. The aim of the invention is to provide solutions with which an improved electronic analysis of the signals that are representative with regard to respiratory activity can be achieved. To this end, the invention provides that viewing results are obtained within the scope of a signal-processing viewing of said measurement signal and make a differentiation between obstructive and central respiratory disorders possible. The viewing results are determined, in particular, while taking into account changes of selected breathing characteristics such as, for example, the change in the ratio of inhalation time to exhalation time.

Claims

1-28. -28. (canceled)

29. A method of controlling the pressure provided to a patient by a pressure regulating device, the method comprising:

providing a supply of respiratory gas at a first pressure level above the ambient pressure level;

measuring a signal indicative of respiratory activity;

determining an inspiration phase and an expiration phase of each breath from the signal;

detecting an inspiration time and an expiration time of each breath for successive breaths;

detecting a variation in the duration of the inspiration time with respect to the expiration time;

determining the presence of obstruction of the upper respiratory tract based on the variation of the duration of inspiration time; and

adjusting the first pressure level based on the determined presence of obstruction.

30. The method according to claim 29, further comprising determining a ratio of the inspiration time to the expiration time for each said breaths and detecting a variation in the ratio to determine the presence of obstruction of the upper respiratory tract.

31. The method according to claim 29, wherein the first pressure level is increased based on the determined presence of obstruction of the upper respiratory tract.

32. The method according to claim 29, wherein the presence of obstruction of the upper respiratory tract is detected based on comparative analysis of successively occurring changes in duration of the inspiration time with respect to the expiration time.

33. The method according to claim 29, wherein the signal indicative of respiratory activity is a flow signal.

34. The method of claim 33, further comprising determining a first derivative of flow from the flow signal.

35. The method of claim 34, wherein the first derivative of flow is determined for a region of phase change in each breath.

36. The method of claim 35, wherein the determining of the presence of obstruction of the upper respiratory tract includes determining changes in the first derivative of flow over successively occurring breaths.

37. The method according to claim 36, wherein the region of phase change is directed to at least one of the beginning of the inspiration phase and the end of the inspiration phase.

38. The method of claim 34, further comprising analyzing a curve shape during the inspiration phase.

39. The method of claim 38, further comprising calculating an average gradient in simple form for intervals that extend over a predetermined percentage of a time duration of the inspiration phase.

40. The method of claim 39, further comprising variably calculating a gradient at a phase change within a window over the inspiration phase.

41. The method according to claim 39, wherein the predetermined percentage is at least 50%.

42. The method according to claim 38, wherein the predetermined percentage is 80%.

43. The method according to claim 42 wherein the curve shape during the inspiration phase is analysed in an interval between 10% after the beginning of the inspiration cycle and 10% before the end of the inspiration cycle.

44. The method according to claim 38, wherein the analysis of the curve shape includes determining a number of local maxima and minima, an amplitude of the local maxima and minima, a sequence of the magnitude of amplitudes of the local maxima and minima, and a frequency in the sequence of the local maxima and minima.

45. The method according to claim 38, further comprising determining a Pcrit value and using the Pcrit value in determining the level of adjustment in the first pressure level.

46. An apparatus including a processor configured to carry out the method set forth in claim 29.