Mechanical chest wall oscillator

• US 6,736,785 B1
• Filed: 01/04/2001
• Issued: 05/18/2004
• Est. Priority Date: 08/09/1999
• Status: Expired due to Term

• Current Assignee: Hill-Rom Services Pte Ltd. (Baxter International Inc.)
• Original Assignee: Advanced Respiratory, Inc. (Baxter International Inc.)
• Inventors: Van Brunt, Nicholas P.
• Primary Examiner(s): DeMille, Danton D.
• Application Number:
  US09/754,672
• Time in Patent Office: 1,230 Days
• Field of Search: 601/41-44, 601/148-152
• US Class Current: 601/44
• CPC Class Codes: A61H 2031/025 using the same pump for pressure and vacuum, not being driven at the respiratory rate, e.g. blowers
• CPC Class Codes: A61H 2201/0103 inflatable
• CPC Class Codes: A61H 2201/1238 with hydraulic or pneumatic drive
• CPC Class Codes: A61H 2201/165 Wearable interfaces
• CPC Class Codes: A61H 23/04 with hydraulic or pneumatic drive hydraulic or Pneumatic massages, A61H9/00; underwater massages, A61H33/00
• CPC Class Codes: A61H 31/00 Artificial respiration or heart stimulation, e.g. heart massage artificial respiration by treatment with gas or air, e.g. mouth-to-mouth respiration A61M16/00; applying electric currents by contact electrodes for stimulation, e.g. heart pace-makers A61N1/36 ; teaching or training models, demonstration models for medical purposes G09B23/288
• CPC Class Codes: A61H 31/006 Power driven

Abstract

A portable high frequency chest wall oscillation (HFCWO) apparatus for the purposes of airway lung clearance and ventilation includes a circumferential chest band which is placed around a person'"'"'s chest and a drive which is connected to the chest band for cyclically varying the circumference of the chest band to apply an oscillating compressive force to the chest of the person. The apparatus maintains the oscillating compressive force applied by the chest band to the chest of the person at a substantially constant level such that the person is able to continue chest expansions and contractions during a breathing cycle.

Claims

1. The chest wall oscillator for clearing an air passage of a person, the chest wall oscillator comprising:

a chest band having first and second ends and inner and outer surfaces for placement around the chest of the person;

a drive carried by the chest band for cyclically varying a circumference of the chest band to apply an oscillating compressive force on the chest of the person; and

means for maintaining the oscillating compressive force applied by the chest band on the chest of the person at a substantially constant level as the chest expands and contracts during the person'"'"'s breathing cycle wherein the means for maintaining pass through the oscillating compressive force to the chest and filter a breathing force.

2. The chest wall oscillator of claim 1, wherein the means for maintaining the oscillating compressive force substantially constant comprises a foam piece attached to the inner surface the chest band for engaging the chest of the person, the foam piece including pores having opening sizes selected to provide discrimination between the oscillating compressive force and the breathing force.

3. The chest wall oscillator of claim 2, wherein the foam piece is enclosed by a flexible airtight material.

4. The chest wall oscillator of claim 1, wherein the means for maintaining the oscillating compressive force substantially constant comprises a flexible substantially airtight material carried by the chest band for engaging the chest of the person, the chest band including a plurality of holes with opening sizes selected to provide discrimination between a drive force and the breathing force.

5. The chest wall oscillator of claim 4, and further comprising:

a pressure maintaining mechanism in communication with the flexible substantially airtight material.

6. The chest wall oscillator of claim 5, and further comprising:

a blower in communication with the pressure maintaining mechanism.

7. The chest wall oscillator of claim 1, wherein the drive comprises:

a motor connected to the first end of the chest band; and

a linkage connected to the second end of the chest band and driven by the motor to cyclically move the second end of the chest band relative to the first end of the chest band.

8. The chest wall oscillator of claim 7, wherein the means for maintaining the oscillating compressive force substantially constant comprises a viscous coupling connection between the linkage and the second end of the chest band.

9. The chest wall oscillator of claim 8, wherein the viscous coupling further comprises:

a cylinder filled with a viscous fluid; and

a piston moving within the cylinder with an opening through which the viscous fluid flows.

10. The chest wall oscillator of claim 7, wherein the means for maintaining the oscillating compressive force substantially constant comprises the motor.

11. The chest wall oscillator of claim 10, and further comprising:

a pressure sensor that senses a tension force in the chest band and signals the tension force to the motor.

12. The chest wall oscillator of claim 10, and further comprising:

an air bladder carried by the chest band for engaging the chest of the person.

13. The chest wall oscillator of claim 12, and further comprising:

a pressure transducer in communication with the air bladder that senses air pressure in the air bladder and signals the air pressure to the motor.

14. The chest wall oscillator of claim 1, wherein the drive comprises:

a motor connected to the first end of the chest band;

an arm connected to the second end of the chest band;

a cam driven by the motor;

a cam follower connected to the arm to translate motion of the cam to motion of the arm; and

wherein the first end of the chest band cyclically moves relative to the second end of the chest band.

15. The chest wall oscillator of claim 1, and further comprising:

an air bladder carried by the chest band for engaging the chest of the person.

16. The chest wall oscillator of claim 15, and further comprising:

an inflation device connected to the air bladder.

17. The chest wall oscillator of claim 15, and further comprising:

a pressure relief mechanism in communication with the air bladder.

18. The chest wall oscillator of claim 15, wherein the air bladder is attached to the inner surface of the chest band.

19. The chest wall oscillator of claim 1, wherein the drive cyclically varies the circumference of the chest band at a frequency in a range of about 5 Hz to about 20 Hz.

20. The chest wall oscillator of claim 1, wherein the oscillating compressive force is maintained in a range of about 5 Hz to about 20 Hz and the breathing cycle is about 1 cycle per 4 seconds.

21. The chest wall oscillator of claim 1, and further comprising:

a fastener element on the outer surface of the chest band for connecting the chest band to the drive.

22. A chest wall oscillator for clearing an air passage of a person, the chest wall oscillator comprising:

a chest band having first and second ends and inner and outer surfaces for placement around a chest of the person;

a drive carried by the chest band for cyclically varying a circumference of the chest band to apply an oscillating compressive force on the chest of the person;

means for compensating for chest circumference changes during the person'"'"'s breathing cycle such that the oscillating compressive force applied on the chest of the person is substantially unaffected by chest circumference changes; and

means for passing through the oscillating compressive force to the chest and filtering a breathing force.

23. The chest wall oscillator of claim 22 wherein the means for compensating is connected to the chest band.

24. The chest wall oscillator of claim 22 wherein the means for compensating is connected to the drive.

25. The chest wall oscillator of claim 22, wherein the means for compensating for chest circumference changes during the person'"'"'s breathing cycle comprises a foam piece attached to the inner surface the chest band for engaging the chest of the person, the foam piece including pores having opening sizes selected to provide discrimination between the oscillating compressive force and the breathing force.

26. The chest wall oscillator of claim 22, wherein the means for compensating for chest circumference changes during the person'"'"'s breathing cycle comprises a flexible airtight material carried by the chest band for engaging the chest of the person, the chest band including a plurality of holes with opening sizes selected to provide discrimination between a drive force and the breathing force.

27. The chest wall oscillator of claim 22, wherein the means for compensating for chest circumference changes during the person'"'"'s breathing cycle comprises a viscous coupling connection between the drive and the second end of the chest band.

28. The chest wall oscillator of claim 22, wherein the means for compensating for chest circumference changes during the person'"'"'s breathing cycle comprises a motor.

29. A chest wall oscillator comprising:

a chest band having first and second ends and inner and outer surfaces, the chest band adapted to be placed around a chest of a person;

a drive connected to the chest band, the drive adapted to apply an oscillating compressive force to the chest band; and

a high pass filter operably connected to the chest wall oscillator, the high pass filter adapted to pass through the oscillating compressive force to the chest and filter a breathing force wherein the oscillating compressive force applied on the chest of the person is substantially unaffected by chest circumference changes.

30. A chest wall oscillator comprising:

a chest band having first and second ends and inner and outer surfaces, the chest band adapted to be placed around a chest of a person;

a drive connected to the chest band, the drive adapted to apply an oscillating compressive force to the chest of the person;

means for passing through the oscillating compressive force to the chest and filtering a breathing force; and

means for compensating for chest circumference changes during the person'"'"'s breathing cycle such that the oscillating compressive force applied on the chest of the person is substantially unaffected by chest circumference changes.

31. A chest wall oscillator comprising:

a chest band having first and second ends and inner and outer surfaces, the chest band adapted to be placed around a chest of a person;

a drive adapted to be carried on the person, the chest wall oscillator adapted to apply an oscillating compressive force to the chest of the person;

means for passing through the oscillating compressive force to the chest and filtering a breathing force; and

means for compensating for chest circumference changes during the person'"'"'s breathing cycle such that the oscillating compressive force applied on the chest of the person is substantially unaffected by chest circumference changes.

32. A chest wall oscillator comprising:

a chest band having first and second ends and inner and outer surfaces, the chest band adapted to be placed around a chest of a person;

a drive connected to the chest band, the chest wall oscillator adapted to apply an oscillating compressive force to the chest of the person; and

a high pass filter operably connected to the chest wall oscillator, the high pass filter adapted to pass through the oscillating compressive force to the chest and filter a breathing force wherein the high pass filter comprises a foam piece adapted to compensate for the breathing force.

33. The chest wall oscillator of claim 32 wherein the foam piece comprises a soft cell material, the soft cell material being porous and compressible such that the foam piece is adapted to conform to the chest.

34. The chest wall oscillator of claim 32 wherein the foam piece is adapted to substantially absorb the breathing force and not absorb the oscillating compressive force.

35. A chest wall oscillator comprising:

a chest band having first and second ends and inner and outer surfaces, the chest band adapted to placed around a chest of a person wherein the chest band comprises a foam piece adapted to compensate for a breathing force, the foam piece including pores having opening sizes selected to provide discrimination between an oscillating compressive force and the breathing force; and

a drive connected to the chest band, the chest wall oscillator adapted to apply the oscillating compressive force to the chest of the person.

36. A chest wall oscillator comprising:

a chest band having first and second ends and inner and outer surfaces, the chest band adapted to placed around a chest of a person wherein the chest band comprises a foam piece adapted to compensate for a breathing force and further wherein the foam piece provides a high pass filter effect; and

a drive connected to the chest band, the chest wall oscillator adapted to apply an oscillating compressive force to the chest of the person.

37. The chest wall oscillator of claim 36 wherein the oscillating compressive force passes through to the chest and the breathing force is filtered out.

38. A chest wall oscillator comprising:

a chest band having first and second ends and inner and outer surfaces, the chest band adapted to be placed around a chest of a person;

a drive connected to the chest band; and

a high pass filter operably connected to the chest band, the high pass filter adapted to pass through an oscillating compressive force to the chest and filter a breathing force wherein the high pass filter comprises a flexible substantially airtight material having a plurality of holes.

39. The chest wall oscillator of claim 38 wherein the flexible substantially airtight material having a plurality of holes encloses a foam piece.

40. The chest wall oscillator of claim 38 wherein the flexible substantially airtight material having a plurality of holes is adapted to substantially absorb the breathing force and not substantially absorb the oscillating compressive force.

41. A chest wall oscillator comprising:

a chest band having first and second ends and inner and outer surfaces, the chest band adapted to placed around a chest of a person wherein the chest band comprises a flexible substantially airtight material having a plurality of holes, the plurality of holes having opening sizes selected to provide discrimination between a drive force and a breathing force; and

a drive connected to the chest band.

42. A chest wall oscillator comprising:

a chest band having first and second ends and inner and outer surfaces, the chest band adapted to placed around a chest of a person wherein the chest band comprises a flexible substantially airtight material having a plurality of holes and further wherein the flexible substantially airtight material having a plurality of holes provides a high pass filter effect; and

a drive connected to the chest band.

43. The chest wall oscillator of claim 42 wherein the oscillating compressive force passes through to the chest and the breathing force is filtered out.

44. A chest wall oscillator comprising:

a chest band having first and second ends and inner and outer surfaces, the chest band adapted to be placed around a chest of a person;

a drive connected to the chest band; and

a high pass filter operably connected to the chest wall oscillator, the high pass filter adapted to pass through an oscillating compressive force to the chest and filter a breathing force wherein the high pass filter comprises a viscous coupling operably connected between the chest band and the drive.

45. The chest wall oscillator of claim 44 wherein the viscous coupling is adapted to compensate for the breathing force.

46. The chest wall oscillator of claim 44 wherein the viscous coupling is adapted to substantially absorb the breathing force and not substantially absorb the oscillating compressive force.

47. A chest wall oscillator comprising:

a chest band having first and second ends and inner and outer surfaces, the chest band adapted to be placed around a chest of a person;

a drive connected to the chest band; and

a viscous coupling operably connected between the chest band and the drive wherein the viscous coupling is adapted to transfer the oscillating compressive force to the chest and wherein the viscous coupling is adapted to expand and contract the chest band in response to the breathing cycle of the chest.

48. A chest wall oscillator comprising:

a chest band having first and second ends and inner and outer surfaces, the chest band adapted to be placed around a chest of a person;

a drive connected to the chest band; and

a viscous coupling operably connected between the chest band and the drive wherein the viscous coupling is comprised of a piston having an opening and a cylinder filled with a viscous fluid, the viscous fluid adapted to flow through the opening.

49. The chest wall oscillator of claim 48 wherein the viscous coupling further comprises a spring to maintain tension in the chest band.

50. The chest wall oscillator of claim 48 wherein the opening and viscous fluid are selected to provide discrimination between the drive force and the breathing force.

51. The chest wall oscillator of claim 48 wherein the viscous coupling provides a high pass filter effect.

52. The chest wall oscillator of claim 51 wherein the oscillating compressive force passes through to the chest and the breathing force is filtered out.

53. The chest wall oscillator for clearing an air passage of a person, the chest wall oscillator comprising:

a chest band having first and second ends and inner and outer surfaces for placement around the chest of the person;

a drive carried by the chest band for cyclically varying a circumference of the chest band to apply an oscillating compressive force on the chest of the person; and

means for maintaining the oscillating compressive force applied by the chest band on the chest of the person at a substantially constant level as the chest expands and contracts during the person'"'"'s breathing cycle, the means comprising a high pass filter operably connected to the chest wall oscillator, the high pass filter adapted to pass through the oscillating force to the chest and filter a breathing force.