Apparatus and method for detecting lung sounds using an implanted device

• US 20040127807A1
• Filed: 12/27/2002
• Published: 07/01/2004
• Est. Priority Date: 12/27/2002
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Stahmann, Jeffrey E., Zhu, Quingsheng, Hatlesad, John D.
• Granted Patent: US 6,949,075 B2
• Time in Patent Office: Days
• US Class Current: 600/529
• CPC Class Codes: A61B 7/003 Detecting lung or respiration noise
• CPC Class Codes: A61N 1/36514 controlled by a physiological quantity other than heart potential, e.g. blood pressure controlled by two or more physical parameters A61N1/36585
• CPC Class Codes: A61N 1/36535 controlled by body position or posture

Abstract

Adventitious lung sounds indicative of lung congestion are detected using an implantable sensor. The sensor is adapted to be positioned adjacent to a pulmonary system and to output signals indicative of lung sounds in response to pulmonary system activity. A controller receives the signals and processes the signals to detect the presence of adventitious lung sounds. A respiratory cycle sensor operating in conjunction with the lung-sound sensor enables classification of an adventitious lung sound according to its time occurrence within the respiratory cycle. Posture sensing in conjunction with lung-sound sensing provides valuable additional information as to the severity of the lung congestion.

Claims

1. A lung sound detection system comprising:

an implantable sensor adapted to be positioned adjacent to a pulmonary system and to output signals indicative of lung sounds in response to pulmonary system activity; and

a controller adapted to receive the signals and to process the signals to detect the presence of adventitious lung sounds.

2. The system of claim 1 wherein the sensor is associated with an implantable device.

3. The system of claim 1 wherein the sensor is a pressure sensor.

4. The system of claim 1 wherein the sensor is a vibration sensor.

5. The system of claim 4 wherein the vibration sensor is an accelerometer.

6. The system of claim 1 wherein in order to process the signals, the controller is further adapted to:

filter the signals to remove frequencies unrelated to adventitious lung sounds; and

compare any remaining signals to a criteria indicative of adventitious lung sounds.

7. The system of claim 5 wherein the criteria indicative of adventitious lung sounds comprises a threshold amplitude.

8. The system of claim 7 wherein the controller is further adapted to compare any signals indicative of adventitious lung sounds to a criteria indicative of the severity of adventitious lung sounds.

9. The system of claim 8 wherein the criteria indicative of the severity of adventitious lung sounds comprises a threshold amplitude.

10. The system of claim 8 wherein the criteria indicative of the severity of adventitious lung sounds comprises a time duration.

11. The system of claim 6 wherein in order to process the signals, the controller is further adapted to:

obtain a spectrum analysis of the signals; and

compare those components of the spectrum analysis indicative of adventitious lung sounds to a threshold intensity.

12. The system of claim 11 wherein the controller is further adapted to compare any components indicative of adventitious lung sounds to a criteria indicative of the severity of adventitious lung sounds.

13. The system of claim 12 wherein the criteria indicative of the severity of adventitious lung sounds comprises a threshold intensity.

14. The system of claim 12 wherein the criteria indicative of the severity of adventitious lung sounds comprises a time duration.

15. The system of claim 1 wherein the implantable sensor is further adapted to output signals indicative of the posture of the body associated with the pulmonary system, and the controller is further adapted to receive the signals and to process the signals to detect the posture of the body.

16. The system of claim 15 wherein in order to process the signals, the controller is further adapted to:

filter the signals to remove frequencies unrelated to posture; and

compare any remaining signals to a criteria indicative of a specific posture.

17. The system of claim 1 further comprising a respiratory sensor adapted to output signals indicative of the respiratory cycle associated with the pulmonary system.

18. The system of claim 17 wherein the controller is further adapted to receive the respiratory-cycle signals, to detect portions of the respiratory cycle based on the respiratory-cycle signals and to process lung-sound signals only during a specific portion of the respiratory cycle.

19. The system of claim 18 wherein the portions of the respiratory cycle comprise an inspiratory portion and an expiratory portion and the controller is adapted to process the lung-sound signals only during the inspiratory portion.

20. The system of claim 19 wherein the inspiratory portion comprises an early portion and a late portion and the controller is further adapted to detect these portions.

21. A system for providing data related to the pulmonary system, said system comprising:

an implantable sensor adapted to be positioned adjacent to a pulmonary system and to output signals indicative of sounds;

an implantable respiratory cycle sensor adapted to output signals indicative of the respiratory cycle associated with the pulmonary system; and

a controller adapted to receive the sound signals and the respiratory-cycle signals, to generate data representative of the signals and to provide the data to a secondary device.

22. The system of claim 21 wherein the controller is adapted to filter the sound signals to remove signal components unrelated to the activity of the pulmonary system.

23. The system of claim 22 wherein the controller is further adapted to filter the remaining sound signals to remove signal components unrelated to adventitious lung sounds.

24. The system of claim 21 wherein the controller is adapted to detect portions of the respiratory cycle based on the respiratory-cycle signals and to generate and provide data only during a specific portion of the respiratory cycle.

25. The system of claim 21 wherein the controller is adapted to process the respiratory-cycle signals to identify the inspiratory portion of the cycle and to generate and provide data only during the inspiratory portion.

26. The system of claim 21 wherein the secondary device is a memory.

27. The system of claim 26 wherein the memory is part of an implantable device.

28. The system of claim 21 wherein the secondary device is a display.

29. An implantable system comprising:

a sensor for detecting lung sounds and for generating sensed signals indicative of the lung sounds;

an interface circuit for communicating with an external system; and

a controller coupled to the sensor and the interface circuit, configured to receive the lung-sound signals, to generate data representative of the lung sounds from the sensed signals and to transmit the lung-sound data to the external system through the interface circuit.

30. An implantable system comprising:

an implantable sensor adapted to be positioned adjacent to a pulmonary system and to output signals indicative of lung sounds;

at least one stimulating lead adapted to be positioned within a heart;

a pulse generator adapted to output electrical pulses to the lead; and

a controller adapted to receive the lung-sound signals, to monitor the lung-sound signals for the presence of adventitious lung sounds and to control the output of the pulse generator in response to the characteristics of the adventitious lung sounds.

31. A method of detecting lung sounds comprising:

obtaining signals indicative of lung sounds from an implantable sensor positioned adjacent to a pulmonary system; and

processing the signals to detect the presence of adventitious lung sounds.

32. The method of claim 31 wherein processing comprises:

filtering the signals to remove frequencies unrelated to adventitious lung sounds; and

comparing any remaining signals to a criteria indicative of adventitious lung sounds.

33. The method of claim 32 wherein processing further comprises:

comparing any signals indicative of adventitious lung sounds to a criteria indicative of the severity of adventitious lung sounds.

34. The method of claim 33 wherein the criteria indicative of the severity of adventitious lung sounds comprises a threshold amplitude.

35. The system of claim 33 wherein the criteria indicative of the severity of adventitious lung sounds comprises a time duration.

36. The method of claim 31 wherein processing comprises:

obtaining a spectrum analysis of the signals; and

comparing those components of the spectrum analysis indicative of adventitious lung sounds to a threshold intensity.

37. The method of claim 36 wherein processing further comprises:

comparing any components indicative of adventitious lung sounds to a criteria indicative of the severity of adventitious lung sounds.

38. The method of claim 37 wherein the criteria indicative of the severity of adventitious lung sounds comprises a threshold intensity.

39. The method of claim 37 wherein the criteria indicative of the severity of adventitious lung sounds comprises a time duration.

40. The method of claim 31 further comprising:

receiving signals indicative of the posture of the body associated with the pulmonary system from an implantable sensor; and

processing the signals to detect the posture of the body.

41. The method of claim 40 wherein processing the signals comprises:

filtering the signals to remove frequencies unrelated to posture; and

comparing any remaining signals to a criteria indicative of a specific posture.

42. The method of claim 31 further comprising:

receiving output signals indicative of the respiratory cycle associated with the pulmonary system from an implantable respiratory sensor.

43. The method of claim 42 further comprising:

detecting portions of the respiratory cycle based on the respiratory-cycle signals; and

processing lung-sound signals only during specific portions of the respiratory cycle.

44. A method of providing data related to the pulmonary system comprising:

obtaining output signals indicative of sounds from an implantable sensor adapted to be positioned adjacent to a pulmonary system;

output signals indicative of the respiratory cycle associated with the pulmonary system from an implantable respiratory cycle sensor; and

generating data representative of the sound signals and the respiratory-cycle signals; and

providing the data to a secondary device.

45. A method of applying electrical pulses to a heart comprising:

receiving signals indicative of lung sounds from an implantable sensor adapted to be positioned adjacent to a pulmonary system;

monitoring the lung sound signals for the presence of adventitious lung sounds; and

controlling the output of an implantable pulse generator having at least one stimulating lead positioned within a heart, in response to the characteristics of the adventitious lung sounds.