Method and system for improving physiologic status and health via assessment of the dynamic respiratory arterial pressure wave using plethysmographic technique

• US 7,922,664 B2
• Filed: 04/05/2007
• Issued: 04/12/2011
• Est. Priority Date: 04/05/2007
• Status: Active Grant

• Current Assignee: Coherence LLC
• Original Assignee: Coherence LLC
• Inventors: Elliott, Stephen Bennett
• Primary Examiner(s): Marmor, II; Charles A
• Assistant Examiner(s): Natnithithadha; Navin
• Application Number:
  US11/732,819
• Publication Number:
  US 20080249422A1
• Time in Patent Office: 1,468 Days
• Field of Search: 600/488, 600/481, 600490-504, 600483-486, 600/508, 600/509, 600/513, 600/529, 607 17- 26
• US Class Current: 600/484
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence

Abstract

The present invention specifies a method and system for assessing the dynamic respiratory arterial pressure wave using plethysmographic sensing techniques. The dynamic respiratory arterial pressure wave is measured and plotted for purposes of diagnosis and or remedial biofeedback.

Claims

1. A method for assessing a dynamic respiratory arterial pressure wave, comprising:

detecting the dynamic respiratory arterial pressure wave as a function of changing blood volume using a plethysmographic device;

assessing at least one characteristic of the dynamic respiratory arterial pressure wave; and

providing at least one output for diagnostic purposes, wherein the at least one output represents the assessed at least one characteristic of the dynamic respiratory arterial pressure wave, whereby providing the at least one output further comprises defining at least one of a visual target and a visual threshold for the dynamic respiratory arterial pressure wave and providing the at least one of the visual target and the visual threshold to at least one of a clinician and a user.

2. The method of claim 1 wherein assessing the at least one characteristic of the dynamic respiratory arterial pressure wave further comprises measuring at least one parameter associated with the dynamic respiratory arterial pressure wave.

3. The method of claim 2 wherein measuring the at least one parameter associated with the dynamic respiratory arterial pressure wave further comprises measuring at least one of amplitude, frequency, phase, coherence, and centerline of the dynamic respiratory arterial pressure wave, wherein measuring the coherence further comprises measuring consistency of the amplitude, the frequency, and the phase of the dynamic respiratory arterial pressure wave.

4. The method of claim 3 wherein providing the at least one output further comprises displaying the at least one of the amplitude, the frequency, the phase, the coherence, and the centerline of the dynamic respiratory arterial pressure wave.

5. The method of claim 3 wherein measuring the amplitude further comprises measuring at least one of a peak amplitude and a valley amplitude of the dynamic respiratory arterial pressure wave.

6. The method of claim 1 wherein assessing the at least one characteristic of the dynamic respiratory arterial pressure wave further comprises calculating a centerline of the dynamic respiratory arterial pressure wave and filtering the centerline, and wherein providing the at least one output further comprises plotting the centerline of the dynamic respiratory arterial pressure wave.

7. The method of claim 6 wherein calculating the centerline of the dynamic respiratory arterial pressure wave further comprises calculating a root mean square (RMS) value of a pulse wave and adding a baseline blood volume value to the RMS value.

8. The method of claim 1 wherein assessing the at least one characteristic of the dynamic respiratory arterial pressure wave further comprises calculating a difference between a peak and a valley of a centerline of the dynamic respiratory arterial pressure wave to determine an amplitude of the dynamic respiratory arterial pressure wave.

9. The method of claim 1 further comprising detecting a peak blood volume and wherein defining the at least one of the target and the threshold for the dynamic respiratory arterial pressure wave further comprises specifying at least one of an amplitude change, a frequency change, and a phase change for the dynamic respiratory arterial pressure wave based upon the peak blood volume.

10. The method of claim 1 further comprising providing at least one of a programmable target and a programmable threshold for the dynamic respiratory arterial pressure wave, and allowing at least one of a clinician and a user to program the at least one of the programmable target and the programmable threshold.

11. The method of claim 1 further comprising identifying a first peak blood volume and wherein assessing the at least one characteristic of the dynamic respiratory arterial pressure wave further comprises characterizing the dynamic respiratory arterial pressure wave relative to the first peak blood volume.

12. The method of claim 11 further comprising identifying a second peak blood volume and wherein assessing the at least one characteristic of the dynamic respiratory arterial pressure wave further comprises determining whether the second peak blood volume is equal to or different from the first peak blood volume.

13. The method of claim 1 wherein assessing the at least one characteristic of the dynamic respiratory arterial pressure wave further comprises calculating an amplitude and a maximum amplitude of the dynamic respiratory arterial pressure wave and providing the at least one output further comprises providing the amplitude as a percentage of the maximum amplitude of the dynamic respiratory arterial pressure wave.

14. The method of claim 1 further comprising instructing at least one of a clinician and a user to modify breathing frequency and depth to affect an increase in amplitude of the dynamic respiratory arterial pressure wave.

15. The method of claim 1 further comprising instructing at least one of a clinician and a user to relax during exhalation to affect an increase in amplitude of the dynamic respiratory arterial pressure wave.

16. The method of claim 1 further comprising using the dynamic respiratory arterial pressure wave to derive a diagnostic indicator of arterial pressure that is not based on measurement of physical arterial pressure, and wherein providing the at least one output further comprises providing the diagnostic indicator.

17. A system for assessing a dynamic respiratory arterial pressure wave, comprising:

a plethysmographic device adapted to sense changing blood volume; and

a computing device adapted to;

detect the dynamic respiratory arterial pressure wave as a function of the changing blood volume;

assess at least one characteristic of the dynamic respiratory arterial pressure wave; and

provide at least one output for diagnostic purposes, wherein the at least one output represents the assessed at least one characteristic of the dynamic respiratory arterial pressure wave, wherein the computing device is further adapted to define at least one of a visual target and a visual threshold for the dynamic respiratory arterial pressure wave and to provide the at least one output based upon the at least one of the visual target and the visual threshold to at least one of a clinician and a user.

18. The system of claim 17 wherein the computing device is further adapted to measure at least one parameter associated with the dynamic respiratory arterial pressure wave.

19. The system of claim 18 wherein the computing device is further adapted to measure at least one of amplitude, frequency, phase, coherence, and centerline of the dynamic respiratory arterial pressure wave.

20. The system of claim 19 wherein in being adapted to measure the coherence, the computing device is further adapted to measure consistency of the amplitude, the frequency, and the phase of the dynamic respiratory arterial pressure wave.

21. The system of claim 20 further comprising a display, and wherein the computing device is further adapted to provide the at least one output based on the at least one of the amplitude, the frequency, the phase, the coherence, and the centerline of the dynamic respiratory arterial pressure wave via the display.

22. The system of claim 19 wherein the computing device is further adapted to measure at least one of a peak amplitude and a valley amplitude of the dynamic respiratory arterial pressure wave.

23. The system of claim 17 further comprising a display, and wherein the computing device is further adapted to calculate a centerline of the dynamic respiratory arterial pressure wave and to provide the at least one output based on the centerline of the dynamic respiratory arterial pressure wave via the display.

24. The system of claim 23 wherein the computing device is further adapted to calculate a root mean square (RMS) value of a pulse wave and to add a baseline blood volume value to the RMS value.

25. The system of claim 17 wherein the computing device is further adapted to calculate a difference between a peak and a valley of a centerline of the dynamic respiratory arterial pressure wave and to determine an amplitude of the dynamic respiratory arterial pressure wave based upon the difference between the peak and the valley of the centerline of the dynamic respiratory arterial pressure wave.

26. The system of claim 17 wherein the computing device is further adapted to detect a peak blood volume and wherein, in being adapted to define the at least one of the target and the threshold for the dynamic respiratory arterial pressure wave, the computing device is further adapted to specify at least one of an amplitude change, a frequency change, and a phase change for the dynamic respiratory arterial pressure wave based upon the peak blood volume.

27. The system of claim 17 wherein the computing device is further adapted to provide at least one of a programmable target and a programmable threshold for the dynamic respiratory arterial pressure wave and to allow at least one of a clinician and a user to program the at least one of the programmable target and the programmable threshold.

28. The system of claim 17 wherein the computing device is further adapted to identify a first peak blood volume and to characterize the dynamic respiratory arterial pressure wave relative to the first peak blood volume, wherein the first peak blood volume is based upon blood volume values sensed via the plethysmographic device.

29. The system of claim 28 wherein the computing device is further adapted to identify a second peak blood volume and to determine whether the second peak blood volume is equal to or different from the first peak blood volume.

30. The system of claim 17 wherein the computing device is further adapted to calculate an amplitude and a maximum amplitude of the dynamic respiratory arterial pressure wave, and to provide the at least one output based upon the amplitude as a percentage of the maximum amplitude of the dynamic respiratory arterial pressure wave.

31. The system of claim 17 wherein the plethysmographic device further comprises a direct current (DC)-coupled plethysmographic device which is further adapted to assess total blood volume including pulse amplitude.

32. The system of claim 17 wherein the computing device is further adapted to instruct at least one of a clinician and a user to modify breathing frequency and depth to affect an increase in amplitude of the dynamic respiratory arterial pressure wave.

33. The system of claim 17 wherein the computing device is further adapted to instruct at least one of a clinician and a user to relax during exhalation to affect an increase in amplitude of the dynamic respiratory arterial pressure wave.

34. The system of claim 17 wherein the computing device is further adapted to use the dynamic respiratory arterial pressure wave to derive a diagnostic indicator of arterial pressure that is not based on measurement of physical arterial pressure and to provide the at least one output based upon the diagnostic indicator.

35. A method for assessing a dynamic respiratory arterial pressure wave comprising an underlying blood volume wave and a pulse wave, comprising:

detecting the dynamic respiratory arterial pressure wave as a function of changing blood volume using a direct current (DC) plethysmographic device; and

providing at least one output on a display for diagnostic purposes, wherein the at least one output comprises a complex signal including a DC blood volume wave portion and an alternating current (AC) pulse wave portion, wherein the complex signal is representative of the dynamic respiratory arterial pressure wave as a function of respiration, whereby providing the at least one output further comprises defining at least one of a visual target and a visual threshold for the dynamic respiratory arterial pressure wave and providing the at least one of the visual target and the visual threshold to at least one of a clinician and a user.

36. The method of claim 35, wherein the at least one output further comprises variations in the complex signal as a function of respiration.