Controlliing gas or drug delivery to patient

• US 6,431,171 B1
• Filed: 11/05/1999
• Issued: 08/13/2002
• Est. Priority Date: 05/07/1997
• Status: Expired due to Term

• Current Assignee: Compumedics Limited
• Original Assignee: Compumedics Limited
• Inventors: Burton, David
• Primary Examiner(s): Weiss, John G.
• Assistant Examiner(s): EREZO, DARWIN P
• Application Number:
  US09/423,380
• Time in Patent Office: 1,012 Days
• Field of Search: 128/204.18, 128/204.21, 128/204.22, 128/204.23, 128/848, 381/71
• US Class Current: 128/204.18
• CPC Class Codes: A61M 15/00 Inhalators drug delivery in endotracheal tubes A61M16/04
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 2230/005 Parameter used as control input for the apparatus
• CPC Class Codes: A61M 2230/04 Heartbeat characteristics, e.g. ECG, blood pressure modulation
• CPC Class Codes: A61M 2230/08 Other bio-electrical signals
• CPC Class Codes: A61M 2230/10 Electroencephalographic signals
• CPC Class Codes: A61M 2230/18 Rapid eye-movements [REM]
• CPC Class Codes: A61M 2230/205 partial oxygen pressure (P-O2)
• CPC Class Codes: A61M 2230/60 Muscle strain, i.e. measured on the user

Abstract

An apparatus is provided for controlling gas delivery to a patient, to maintain effective respiratory function. The apparatus includes sensors for monitoring one or more physiological variables such as breathing airflow sound, EEG, EOG, ENG, and/or patient position. The apparatus includes a determining component for deriving, from the sensed variables, data representing a respiratory event and a component for determining from the data a gas pressure or modulated gas pressure to counteract tissue vibration associated with the respiratory event, thereby tending to cancel the respiratory event. The determining component may include an algorithm adapted to generate a gas pressure signal substantially 180 degrees out of phase relative to the tissue vibration. The apparatus may include a drug delivery module operable to deliver a drug in accordance with the sensed physiological variable and the determining component.

Claims

1. An apparatus for controlling gas delivery to a patient to maintain effective respiratory function, said apparatus including:

a monitoring component adapted to monitor at least one physiological variable of a patient during an application of a positive gas pressure to an airway of the patient, to provide monitoring information representing the at least one physiological variable; and

a processing component including a deriving component in communication with the monitoring component, adapted to receive the monitoring information and, based on the monitoring information, to derive data representing a respiratory event characterized by a vibration of body tissue along the airway;

said processing component further including a determining component coupled to receive said data and including an algorithm operable to generate a control signal based on said data, said control signal being substantially 180 degrees out of phase relative to said data and being applicable to control a gas delivery device to modulate said positive gas pressure in a manner to counteract said vibration of the body tissue, thereby tending to cancel the respiratory event.

2. The apparatus according to claim 1 wherein said control signal includes a modulated component.

3. The apparatus according to claim 2 wherein said modulated component is substantially 180 degrees out of phase relative to said data representing a respiratory event.

4. The apparatus according to claim 2 wherein said modulated component is adapted to acoustically cancel vibration in an upper palate of the patient.

5. The apparatus according to claim 2 wherein the control signal further includes an additional component selected from the group consisting of:

a substantially continuous component, and a component that changes relatively slowly when compared to said modulated component.

6. The apparatus according to claim 1 wherein at least one of said deriving component and said determining component includes a digital processor.

7. The apparatus according to claim 1 wherein the gas delivery device includes a gas pressure valve.

8. The apparatus according to claim 1 wherein the gas delivery device includes an acoustic transducer.

9. The apparatus according to claim 1 further including a device for delivering a drug to the patient.

10. The apparatus according to claim 1 wherein said positive gas pressure, when controlled in accordance with the control signal, is substantially constant.

11. The apparatus according to claim 1 wherein said positive gas pressure, when controlled in accordance with the control signal, is variable.

12. The apparatus according to claim 1 wherein the at least one physiological variable is selected from the group consisting of:

breathing airflow, respiratory effort, and breathing sound.

13. The apparatus according to claim 1 wherein the at least one physiological variable is selected from the group consisting of:

brain waves, eye movement, heart beat, muscle function, and patient position.

14. The apparatus according to claim 1 wherein the deriving component further is adapted to derive data representing a respiratory state of the patient.

15. The apparatus according to claim 14 wherein the control signal is applicable to control the gas delivery device to control said positive gas pressure in accordance with the control signal to substantially prevent a deterioration in said respiratory state.

16. The apparatus according to claim 14 wherein said deriving component employs an algorithm to derive the data representing a respiratory state.

17. The apparatus according to claim 14 wherein said deriving component is adapted to evaluate at least one state selected from the group consisting of:

sleep states, and arousal states.

18. The apparatus according to claim 14 wherein said deriving component is adapted to detect arousals.

19. An apparatus for controlling drug delivery to a patient to maintain effective respiratory function, said apparatus including:

a monitoring component adapted to monitor at least one physiological variable of a patient during an application of a positive gas pressure to an airway of the patient, to provide monitoring information representing the at least one physiological variable; and

a processing component including a deriving component in communication with the monitoring component to receive the monitoring information, and, based on the monitoring information, to derive data representing a respiratory state of the patient and further representing a respiratory event characterized by vibration of body tissue along the airway;

said processing component further including a control component receiving said data and, based on the data, using an algorithm to generate a control signal substantially 180 degrees out of phase relative to said data to control a gas delivery device in a manner to counteract said vibration of the body tissue, thereby tending to cancel the respiratory event, and further adapted to initiate a delivery of a drug to the patient to substantially prevent a deterioration in said respiratory state.

20. The apparatus according to claim 19 wherein said at least one physiological variable is selected from the group consisting of:

breathing airflow, and breathing sound.

21. The apparatus according to claim 19 wherein said drug includes ventilum.

22. A method for controlling gas delivery to a patient, said gas delivery being adapted to maintain effective respiratory function, said method including:

operating a gas delivery device to provide a positive pressure delivery of a gas to an airway of a patient;

during said delivery, monitoring at least one physiological variable of the patient, to provide monitoring information representing the at least one physiological variable;

using the monitoring information to derive data representing a respiratory event comprising vibration of body tissue along the airway;

using the data to generate a control signal, including using an algorithm to generate the control signal, said control signal being substantially 180 degrees out of phase relative to said data;

using the control signal to modulate said delivery in a manner to counteract said vibration of the body tissue, thereby tending to cancel the respiratory event.

23. The method according to claim 22 wherein said control signal includes a modulated component.

24. The method according to claim 23 wherein said modulated component is substantially 180 degrees out of phase relative to the data representing a respiratory event.

25. The method according to claim 23 filter including using said modulated component to operate a gas delivery device to cancel vibration in an upper palate of the patient.

26. The method according to claim 22 wherein said control signal includes a substantially continuous component.

27. The method according to claim 22 wherein said using the control signal to control delivery of a gas to the patient comprises causing a gas delivery device to provide the gas to the patient at a substantially constant positive pressure.

28. The method according to claim 22 wherein said using the control signal to control delivery of a gas to the patient comprises causing a gas delivery device to provide the gas to the patient at a varying positive pressure.

29. The method according to claim 22 wherein the control signal further includes an additional component selected from the group consisting of:

a substantially continuous component, and a component that changes relatively slowly when compared to said modulated component.

30. The method according to claim 22 wherein monitoring the at least one physiological variable includes monitoring a physiological variable selected from the group consisting of:

breathing air flow, respiratory efforts and breathing sound.

31. The method according to claim 22 wherein monitoring the at least one physiological variable includes monitoring physiological variable selected from the group consisting of:

brain waves, eye movement, heart beat, muscle function, and patient position.

32. The method according to claim 22 further including using the monitoring information to derive data representing a respiratory state of the patient corresponding to the at least one physiological variable.

33. The method according to claim 32 wherein said using the control signal to control delivery of a gas to the patient comprises causing a gas delivery device to substantially prevent a deterioration in said respiratory state.

34. An apparatus for controlling gas delivery to a patient to maintain effective respiratory function, said apparatus including:

a monitoring component adapted to monitor at least one physiological variable of a patient during an application of a positive gas pressure to an airway of the patient, to provide monitoring information representing the at least one physiological variable; and

a processing component including a deriving component in communication with the monitoring component to receive the monitoring information, and, based on the monitoring information, to derive data representing a respiratory event characterized by vibration of body tissue along the airway;

said processing component further including a determining component coupled to receive said data and adapted to generate a control signal based on said data, said control signal including a modulated component substantially 180 degrees out of phase relative to said data representing a respiratory event and being applicable to control a gas delivery device to modulate said positive gas pressure in accordance with the modulated component of the control signal to counteract said vibration of body tissue, thereby tending to cancel the respiratory event.

35. The apparatus according to claim 34 wherein said modulated component is adapted to acoustically cancel vibration in an upper palate of the patient.

36. The apparatus according to claim 34 wherein said control signal further includes an additional component selected from the group consisting of:

a substantially continuous component, and a component that changes relatively slowly when compared to said modulated component.

37. A method for controlling gas delivery to a patient, said gas delivery being adapted to maintain effective respiratory function, said method including:

operating a gas delivery device to provide a positive pressure delivery of a gas to an airway of a patient;

during the delivery, monitoring at least one physiological variable of a patient, to provide monitoring information representing the at least one physiological variable;

using the monitoring information to derive data representing a respiratory event including vibration of body tissue along the airway;

using the data to generate a control signal that includes a modulated component that is substantially 180 degrees out of phase relative to the data representing the respiratory event; and

using the modulated component of the control signal to modulate the positive pressure of the gas to counteract said vibration of the body tissue, thereby tending to cancel the respiratory event.

38. The method according to claim 37 further including using said modulated component to operate a gas delivery device to cancel vibration in an upper palate of the patient.